JP2006301091A - Image forming method and developing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method and a developing device causing little decrease in image quality such as stripes caused by contamination of a member due to a deterioration in a developer, even when high-speed printing is repeated. <P>SOLUTION: The image forming method comprises: developing an electrostatic charge latent image carried on a latent image carrier with a developer filled into a developing device; transferring the developed developer image through or without an intermediate transfer body to a transfer material; and fixing the developer image on the transfer material onto the transfer material by a heating and pressurizing means, wherein a developer housing chamber of the developing device comprises two developer housing regions each having an agitating and conveying means. The developer is a nonmagnetic developer comprising toner particles containing at least a binder resin, a colorant and a release agent, and inorganic fine powder. An aggregation degree G of the nonmagnetic developer is in the range of 35≤G≤80, an aggregation degree SG after shaken is in the range of 40≤SG≤85, and a ratio SG/G of the aggregation degree GS after shaken to the aggregation degree G is in the range of 0.95≤SG/G≤1.50. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  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, electrophotographic techniques represented by copying machines and printers have been colorized, and higher-speed and higher-definition image quality is required. Printers have expanded from office equipment to personal use, and usability has become a more important factor. In response to these requests, a process cartridge system has been developed that integrates the developer and developer container, or the latent image carrier and charging mechanism, and the user only needs to replace the process cartridge when the developer is used up. Thus, it is freed from troublesome toner replenishment work, realizing maintenance-free operation. This process cartridge is required to be downsized and simplified due to the trend toward miniaturization and cost reduction of the office equipment itself. As the development system optimal for miniaturization, the one-component development system, especially the colorization view. The non-magnetic one-component development method is a good match when it is included.

  However, in the one-component development method, fresh toner is not replenished as in the two-component development method, and thus the developer quality must be kept in an initial state as much as possible until the developing cartridge reaches the end of its life. When the developer deteriorates with the endurance, various problems such as dot dropout, developer scattering outside the dot, developer fogging on the background, and image defects due to developer contamination on the member are caused.

  The main cause of developer deterioration is mechanical stress repeatedly applied to the developer in the developer unit. The higher the process speed, the greater the stress applied to the developer. Various studies have been made on the control of agitation, transportability, and circulation of the developer.

  In particular, the development of single-component developers that support high-speed process speeds and large capacities has been a long time for monochrome printers.

  For a monochrome high-speed printer, a magnetic one-component jumping method in which a magnetic pole is provided on a developer carrier and a magnetic developer is coated with the magnetic restraint force is the mainstream. The magnetic one-component jumping development system is relatively unrestricted by physical properties such as viscoelasticity required for image gloss control required for full-color developers, and a robust binder design can be achieved. It works favorably on the property and the circulation property (see Patent Documents 1 to 3). A developing device and a process cartridge that make use of these characteristics are arranged so that the developer storage chamber is located above the developing chamber having a developer carrying member serving as a developing region by utilizing the weight of the developer. Is common. Also in the non-magnetic one-component development system, a process cartridge having the above-described configuration and further improving the developer circulation has been proposed (see Patent Document 4).

  When the present inventors evaluated a color non-magnetic one-component developer at a high process speed using the process cartridge having the above-described configuration, development streaks due to member contamination occurred in the latter half of the durability. In our examination, it has been found that the above-described configuration has a limit in developing a color toner that is designed to be relatively soft in order to develop image gloss at a high speed. Usually, the developer is required to have a certain degree of fluidity from the viewpoint of dot reproducibility, but also requires cohesiveness in the vicinity of the developer carrier to ensure quick chargeability. In order to secure the necessary cohesive state for the developer, it is not preferable that the conveying force to the developer carrier is excessively increased because image defects due to fusion to the member and packing appear, but it is not preferable to supply the developer. In order to cause fatal image defects such as white spots, it is general to employ a configuration in which the developer is supplied slightly excessively in the vicinity of the developer carrier. However, in order to make the non-magnetic one-component development method correspond to a high process speed, when a configuration in which the developer storage chamber is positioned above the development chamber as in a conventional developing device, excessive supply stress, As a result, it was found that the life of the developer does not extend due to the poor circulation of the developer under stress.

  In order to avoid this problem, an optimal developer supply method, developing device, and process cartridge configuration, such as a low stress configuration and suppression of segregation of deteriorated developer due to an increase in developer circulation efficiency, are being studied ( (See Patent Documents 5 to 7).

  When the present inventors tested the deterioration state of the developer under all process conditions using these developing devices, the degree of deterioration of the developer was certainly suppressed, and the degree of image quality deterioration accompanying the developer deterioration, and The number of occurrences has been improved. However, as the process speed increases, the load applied to the developer increases and the effect of suppressing the deterioration of the developer is reduced, so that it became clear that the amount of developer loaded is naturally limited.

  On the other hand, there has also been proposed a developer that suppresses the durability deterioration of the developer by controlling the physical properties of the developer itself (see Patent Documents 8 to 9).

  According to the study by the present inventors, it has been confirmed that these toners have improved durability performance. However, in the durability test at a high process speed, the image stability accompanying the developer deterioration in the latter half of the durability was confirmed. I had a problem.

  In addition, an image forming method is proposed in which a developer having specific physical properties and a specific developing device configuration are combined to cope with a high process speed and to mount a large amount of developer (see Patent Document 10). . The above image forming method is compatible only with the magnetic one-component development system and not with a system using non-magnetic toner, but it has a control of the powder characteristics of the developer and a transport and circulation system corresponding to it. It has been found that optimization has a sufficiently advantageous effect on developer deterioration.

  As described above, the image forming method, developing device and process cartridge specialized for the full-color non-magnetic one-component system that supports high-speed process speeds are not yet sufficiently satisfactory, and large-capacity development is possible. There has been a demand for a system that can use the agent in a high quality state until the end.

JP-A-8-101625 JP-A-8-314245 JP 2002-72669 A JP 2003-162136 A JP-A-5-158345 JP 2003-287947 A Japanese Patent Laid-Open No. 2003-302824 JP 2003-177567 A Japanese Patent No. 3002063 JP 2001-42625 A

  The present invention has been made from the above viewpoint, and an object of the present invention is to provide an image forming method and a developing apparatus that can solve the above-described problems of the prior art and maintain high-definition image quality over a long period of time.

  That is, an object of the present invention is to provide an image forming method and a developing device in which even when high-speed printing is repeated, member contamination caused by the deterioration of the developer is caused, and image quality such as streaks is less deteriorated.

  In addition, the present invention has an image forming method and development that has a quick charge rising property of the developer even in any environment, and has little fogging, dropout of the dot, and scattering of the developer outside the dot even after printing a large number of sheets. It is an object to provide an apparatus.

  Furthermore, an object of the present invention is to provide an image forming method and a developing apparatus that can suitably cope with a full-color one-component developer having excellent image gloss and can maintain high-quality image quality over a long period of time.

As a result of earnestly studying an image forming method and a developing apparatus capable of maintaining a high-definition image with a long life, which corresponds to a high-speed process speed in the non-magnetic one-component development method,
The developer agglomeration degree and the agglomeration degree after shaking are highly controlled, and a developer carrier having a development site is disposed above the developer accommodating chamber to maximize the circulation efficiency of the agent. As a result, the inventors have succeeded in significantly reducing the stress applied to the developer, and have invented an excellent image forming method and developing device that can suppress the deterioration of the developer over a long period of time.

That is, in the image forming method of the present invention, the electrostatic charge latent image carried on the latent image carrier is visualized by the developer filled in the developing device, and the visualized developer image is subjected to intermediate transfer. An image forming method in which the image is transferred to a transfer material via a body or not, and a developer image on the transfer material is fixed to the transfer material by a heating and pressing unit;
The developing device includes a developer storage chamber having an opening for storing the developer;
A developing chamber connected to the developer containing chamber through the opening and transporting the developer from the developer containing chamber;
A developer carrying member disposed on the opposite side of the developing chamber from the opening and carrying the developer;
A developer regulating member that contacts the developer carrying member to regulate the amount of the developer on the developer carrying member;
A developer supply member that is disposed in contact with or in proximity to the developer carrier and that supplies the developer to the developer carrier while holding the developer;
The developer storage chamber is composed of two developer storage areas each having a stirring and conveying means,
The developer is transferred from the first developer storage region to the second developer storage region located above the first developer storage region by the stirring and conveying means,
The developer is transferred from the second developer containing area to the developing chamber located above the second developer containing area by the agitating and conveying means, and the developer overflowing from the developing chamber is transferred to the developing chamber. A developing device in which the developer circulates by being transferred from the second developer accommodating portion to the first developer accommodating portion;
The developer is a non-magnetic developer comprising toner particles having at least a binder resin, a colorant, and a release agent and an inorganic fine powder,
The nonmagnetic developer has a release agent content of 1 to 30 parts by weight per 100 parts by weight of the binder resin of the toner particles, the nonmagnetic developer has an aggregation degree G of 35 ≦ G ≦ 80, and an aggregation degree SG after shaking. Is 40 ≦ SG ≦ 85, and the ratio SG / G of the aggregation degree G to the post-shaking aggregation degree SG is 0.95 ≦ SG / G ≦ 1.50.

The developing device of the present invention is a developing device for visualizing an electrostatic charge latent image carried on a latent image carrier with a developer filled in the developing device,
The developing device is connected to the developer accommodating chamber having an opening for accommodating the developer, and the developer accommodating chamber via the opening, and the developer is conveyed from the developer accommodating chamber. A developing chamber, a developer carrying member disposed on the opposite side of the developing chamber from the opening and carrying the developer, and a developer carrier on the developer carrying member in contact with the developer carrying member. A developer regulating member that regulates the amount of the developer, and a developer supply that is disposed in contact with or close to the developer carrying member and supplies the developer to the developer carrying member while holding the developer The developer storage chamber is composed of two developer storage areas each having a stirring and conveying means,
The developer is transferred from the first developer containing area to the second developer containing area located above the first developer containing area by the agitating and conveying means, and from the second developer containing area. The developer is transferred to the developing chamber located above the second developer containing area by the agitating and conveying means, and the developer overflowing from the developing chamber is transferred from the second developer containing portion, A developing device in which the developer circulates by being transferred to the first developer accommodating portion, and the developer comprises toner particles having at least a binder resin, a colorant, and a release agent, and an inorganic fine powder. A non-magnetic developer,
The nonmagnetic developer has a release agent content of 1 to 30 parts by weight per 100 parts by weight of the binder resin of the toner particles, the nonmagnetic developer has an aggregation degree G of 35 ≦ G ≦ 80, and an aggregation degree SG after shaking. Is 40 ≦ SG ≦ 85, and the ratio SG / G of the aggregation degree G to the post-shaking aggregation degree SG is 0.95 ≦ SG / G ≦ 1.50.

  According to the present invention, developer deterioration is suppressed by controlling the static and dynamic flow characteristics of the developer, and the developer structure having the simplest and excellent circulation characteristics, and high-speed printing is repeated. However, it is possible to provide an image forming method and a developing device that can maintain high-definition image quality.

  In addition, the present invention does not cause image defects such as streaks caused by member contamination even when high-speed printing is repeated, and has little fogging, dropout of dots, and scattering of developer outside the dots under any environment. An image forming method and a developing device can be provided.

  Furthermore, the present invention can provide an image forming method and a developing apparatus that can suitably cope with a full-color one-component developer having excellent image gloss and can maintain a high-quality image over a long period of time.

The developer of the present invention is a nonmagnetic developer comprising toner particles having at least a binder resin, a colorant and a release agent and an inorganic fine powder,
The nonmagnetic developer has a release agent content of 1 to 30 parts by weight per 100 parts by weight of the binder resin of the toner particles, the nonmagnetic developer has an aggregation degree G of 35 ≦ G ≦ 80, and an aggregation degree SG after shaking. 40 ≦ SG ≦ 85, and the ratio SG / G of the aggregation degree G to the post-shaking aggregation degree SG satisfies the relationship of 0.95 ≦ SG / G ≦ 1.50. The initial image quality can be maintained over a long period of time by optimally matching the image forming method and the developing device configuration and suppressing the deterioration of the developer.

  According to the study by the present inventors, in a developing device using a conventional non-magnetic one-component developing system, a developer having a certain degree of fluidity is used, and a developing region is formed by a stirring member in the developer containing chamber. The developer is conveyed toward the developer carrying member. The developer conveyed onto the developer carrying member is uniformly coated at the gap between the developer regulating member pressed against the developer carrying member and the developer carrying member, and is quickly frictionally charged, and developed in the developing region. A sufficient amount of charge is maintained. Here, the physical properties required for the developer need to be moderate fluidity from the viewpoint of transportability and dispersibility of stirring share. Further, there is no electrostatic aggregation between the developer particles in the fluidized state of the developer, which is a necessary element in order to satisfy dot reproducibility and scattering properties.

  On the other hand, as in the example shown in FIG. 1, with respect to the developing device, in order to prevent a fatal image defect due to the concept that the developer is used up to the end and the supply failure to the developer carrier, Is disposed above the developing chamber, or the stirring force is controlled, thereby adopting a mechanism that continues to convey the developer slightly slightly toward the developer carrying member from the developer containing chamber.

  Certainly, the above-mentioned conventional developer having fluidity and an image forming method consisting of a mechanism that transports slightly over-supplied has excellent image quality stability, but it takes a developer at a high process speed. There was a problem that the stress was increased, the deterioration of the developer was accelerated, and the image quality in the latter half of the durability was lowered.

  In order to reduce the stress on the developer, we also tested a configuration that reduced the transport force of the developing device and made it compatible with high-speed process speeds. The initial image quality could not be maintained until the developer was used up.

  Therefore, a detailed analysis of the developer circulation in the developing unit and the changes in the developer physical properties with the endurance, the developer near the developer carrier used for development is repeatedly developed in a short cycle. Degradation is accelerated by being supplied to the carrier and subjected to pressure stress by the layer thickness regulating member each time, and the deterioration developer tends to accumulate near the developer carrier, which is a major cause of image quality degradation. It has been found.

  In order to achieve a long life at a high process speed, the present inventors have intensively studied how to circulate the developer with low stress, and as a result, the developing device is tilted rearward and developed from the developer containing chamber. While the developer is transported to the developer carrier, the excess developer overflowing from the developing chamber has a general circulation structure in which the developer flows into the developer containing chamber by a stirring mechanism using its own weight, so that the developer can be directly transferred to the developer. The inventors have succeeded in inventing an image forming method and a developing apparatus capable of suppressing such stress and preventing a biased stress from being applied only to a certain developer, and maintaining initial image quality for a longer period of time. A specific developing apparatus of the present invention described above is shown in FIG.

  In the image forming method according to the present invention, it is essential to control the static and dynamic agglomeration characteristics and charging characteristics of the developer, which is the liver of image quality, to satisfy highly prescribed physical properties.

  The static agglomeration property referred to here is a physical property represented by the agglomeration degree G, and we are easy to disperse the developer particles from a stationary state to achieve a high-definition image and agitation in the developing device. As a parameter indicating the degree of share dispersibility, a condition that can be appropriately monitored was derived.

  Further, the significance of the degree of aggregation after shaking SG, which is a parameter indicating dynamic agglomeration characteristics, is expressed in terms of fluidity and ease of dispersion between developer particles during continuous printing in the developer developing apparatus. It is an index to be monitored, and is effective for the stirring share of the developer and the image quality, especially the dot reproducibility. In particular, the flow characteristics of the initial developer and the developer after the endurance change slightly with the endurance, but the change after the endurance can be achieved by controlling G and SG of the initial developer highly. Therefore, the initial image quality can be maintained.

  Further, the aggregation characteristics of the non-magnetic one-component developer are closely correlated with the aggregation of electrostatic developer particles, and the charging ability of the developer can be known by measuring G and SG. By controlling SG / G within a specified range, it is possible to guarantee a high-quality image with good charge rising property in all environments and excellent in fog and dot reproducibility over a long period of time.

  That is, the cohesion degree G of the non-magnetic one-component developer according to the present invention is 35 ≦ G ≦ 80, the post-shaking cohesion degree SG is 40 ≦ SG ≦ 85, and the cohesion degree G and the post-shaking cohesion degree SG are The ratio SG / G must satisfy the relationship of 0.95 ≦ SG / G ≦ 1.50.

  Further, the more preferable aggregation degree G is 40 ≦ G ≦ 75, the aggregation degree SG after shaking is 45 ≦ SG ≦ 80, and the ratio SG / G between the aggregation degree G and the aggregation degree SG after shaking is 1.00 ≦ G By satisfying the relationship of SG / G ≦ 1.45, a high-quality image forming method with less durability deterioration can be provided.

  When a developer having a cohesion degree G of less than 35 is used in the developing device of the present invention, the developer cohesiveness in the vicinity of the developer carrying member is insufficient, and the developer on the developer carrying member has a good charge. The amount cannot be applied, and the fog and dot reproducibility deteriorates with durability. Further, the developer conveying force tends to be insufficient, and the developer in the developer storage chamber cannot be used up to the end, which is uneconomical.

  On the other hand, when G exceeds 80, the share of the developer accompanying the conveyance increases, and in particular, the deterioration of the developer is promoted in the supply peeling process to the developer carrying member, and the durability life is reduced. Further, as the developer consumption progresses, the agitation tends to be poor, and the risk of causing fatal image defects such as white-out images increases.

  When the degree of aggregation SG after shaking is less than 40, the cohesiveness in the vicinity of the developer carrier is insufficient, the desired charge amount cannot be obtained, and the fog and dot reproducibility is poor.

  On the other hand, when SG exceeds 85, the developer cannot be uniformly coated on the developer carrying member, and density unevenness occurs particularly in a solid image. In addition, dot reproducibility and fog are also deteriorated, and image quality is deteriorated.

  Developers with SG / G less than 0.95 have poor charge rising ability, and are particularly poor in fog and dot reproducibility in a high temperature and high humidity environment.

  On the other hand, when SG / G exceeds 1.50, the developer fluidity immediately after the start of the image forming apparatus and the developer fluidity during continuous printing are too different, so the density stability is poor and the image quality is lowered. .

The measurement of the degree of aggregation G was performed using a powder tester manufactured by Hosokawa Micron Co., Ltd., with a sieve of 200 μm sieve having a sieve size of 75 μm, a sieve of 390 mesh having a sieve size of 38 μm in the middle, and a sieve size of 25 μm. No. 635 mesh sieve set below, 5 g developer aged overnight at 23 ° C. and 50% environment, measured by applying vibration of 0.6 mm amplitude to the table for 15 seconds. It was calculated using the following formula.
Mass% of toner remaining on sieve having a sieve size of 75 μm × 1 (a)
Mass% of toner remaining on sieve having a sieve size of 38 μm × 0.6 (b)
Mass% of toner remaining on sieve having a sieve size of 25 μm × 0.2 (c)
G = (a) + (b) + (c) (%)

  Aggregation degree SG after shaking is set at 150 rpm using a shaker Model-YS-LD (manufactured by Yayoi Co., Ltd.) after putting a developer aged under the same conditions as in cohesion degree G into a 50 cc plastic plastic bottle. The developer shaken at a strength of 2 minutes was quickly poured onto the mesh and measured under the same conditions as the degree of aggregation G.

  In the present invention, the method for controlling the aggregation degree G of developer, the aggregation degree SG after shaking, and SG / G to a desired range is not particularly limited, but the approach from the adhesion of the developer particles themselves, It is possible to design the developer of the present invention by fully considering the two points of the approach from the cohesiveness and the balance thereof.

  Specifically, control of binder resin adhesion and charge amount, control of electrostatic cohesive force by pigment and charge control agent, control by shape such as sphericity and particle size distribution of developer, release agent component and low molecular weight Examples thereof include control by addition of components and control of fluidity and charging characteristics by external additives.

  In the image forming method and the developing device according to the present invention, the compression by the developer transport in the vicinity of the developer carrier is weakened with the aim of reducing the stress of the developer. A quick charge rising ability is required while being frictionally charged by the thickness regulating member. By controlling the initial frictional charge amount and the frictional saturation charge amount indicating the charge rising ability within a predetermined range, stable image quality can be maintained over a long period of time.

  That is, the friction initial charge amount Qi of the nonmagnetic developer in the present invention preferably satisfies 30 ≦ Qi ≦ 70, and the friction saturation charge amount Qf preferably satisfies 55 ≦ Qf ≦ 100.

  A more preferable range of Qi is 35 ≦ Qi ≦ 65, and a more preferable range of Qf is 60 ≦ Qf ≦ 90.

  When Qi is less than 30, image quality such as fogging in a high temperature and high humidity environment may be inferior. On the other hand, when Qi exceeds 70, the coating state on the developer carrier in a low-temperature and low-humidity environment tends to be a non-uniform coating referred to as blotch, and the density uniformity of the solid portion may be inferior.

  When Qf is less than 55, fogging, dot reproducibility, and environmental stability are inferior. When Qf exceeds 100, not only the density stability is inferior, but the maximum density may not be obtained.

  In addition, the charge amount measuring apparatus shown in FIG. 3 is used for the measurement of Qi and Qf of the present invention. Under an environment of temperature 23 ° C. and relative humidity 50%, the surface of the carrier has a distribution of 25 to 40% by mass in the range of particle size 75 to 63 μm and 30 to 75% by mass in the range of particle size 63 to 44 μm. Using a Cu-Zn ferrite carrier coated with a copolymer of 2-ethylhexyl acrylate-methyl methacrylate, a mixture of 9.8 g of a carrier and 0.2 g of a nonmagnetic developer was added to a 50 ml polyethylene-made mixture. Place in a bottle and shake using Model-YS-LD shaker (manufactured by Yayoi Co., Ltd.) at 150 rpm for 15 seconds for Qi measurement and 2 minutes for Qf measurement.

  Next, 0.4 g of the mixture is put in a metal measuring container 72 having a 500-mesh screen 73 at the bottom, and a metal lid 74 is placed. The total weight of the measurement container 72 at this time is weighed and is defined as W1 (g). Next, in the suction machine 71 (at least the part in contact with the measurement container 72 is suctioned), the pressure of the vacuum gauge 75 is set to 2 kPa by suctioning from the suction port 77 and adjusting the air volume control valve 76.

In this state, suction is performed for 2 minutes to remove the developer by suction. The potential of the electrometer 79 at this time is set to V (volt). Here, 78 is a capacitor, and the capacity is C (μF). Moreover, the mass of the whole measuring machine after suction is weighed and is defined as W2 (g). The triboelectric charge amount Q (μC / g) of the toner is calculated as follows:
Q = CV / (W1-W2)

  In order to control the charge amount within the above range, although not particularly limited, the charge amount is generally controlled by the type and amount of the charge control agent and the type and amount of the external additive.

  In a more preferable embodiment of the present invention, it is desirable to contain a charge control agent and a charge control resin in order to perform control so that stable charging ability can be exhibited over a long period of time.

  The charge control agent has excellent characteristics of charge rise, while the charge control resin can maintain a constant charge amount and has excellent durability and environmental stability. By using together, it becomes easy to control the charge amounts such as Qi and Qf within a desired range.

  Further, since the control of the charge amount of the developer and the control of the electrostatic cohesion force are closely related, it is very effective in controlling the cohesion degree G and the post-shaking cohesion degree SG.

  As the charge control agent for controlling the developer to be negatively charged, for example, organometallic compounds and chelate compounds are effective, and monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, and oxycarboxylic acids. And dicarboxylic acid-based metal compounds. Others include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, and the like. Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene and the like can be mentioned. These can be used alone or in combination of two or more.

  Examples of the charge control agent for controlling the developer to be positively charged include nigrosine-modified products such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetra Quaternary ammonium salts such as butylammonium tetrafluoroborate, and onium salts such as phosphonium salts which are analogs thereof and lake pigments thereof, triphenylmethane dyes and lake lakes thereof (as rake agents include phosphotungstic acid Phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide, dicyclohexyltin Diorganotin oxides such as side; dibutyl tin borate, dioctyl tin borate, diorgano tin borate, and the like, such as dicyclohexyl tin borate, and the like. These can be used alone or in combination of two or more.

  In addition, although the usage-amount of a charge control agent changes with kinds of charge control agent to be used, it is preferable that it is 0.01-20 mass parts per 100 mass parts of binder resin, and it is 0.1-10 mass parts. More preferred. The charge control agent may be blended (internally added) to the toner particles, or may be mixed (externally added) with the toner particles.

  Examples of the charge control resin for controlling the developer to be negatively charged include a polymer compound having a sulfonic acid group in the side chain, and in particular, a methacrylic acid monomer containing a sulfonic acid group has a copolymerization ratio of 2 mass. % Or more, preferably 4% by mass or more, and using a polymer compound composed of styrene and / or styrene (meth) acrylate copolymer having a glass transition temperature (Tg) of 45 to 90 ° C., It is particularly preferable because the charging characteristics and the aggregation characteristics can be suitably controlled.

  As said sulfonic acid group containing (meth) acrylamide type monomer, what can be represented by following General formula (1) is preferable, and, specifically, 2-acrylamide-2-methylpropanesulfonic acid and 2-methacrylamide-2- Examples thereof include methyl propane sulfonic acid.

［上記一般式（１）中、Ｒ₁は水素原子、又はメチル基を示し、Ｒ₂とＲ₃は、それぞれ水素原子、Ｃ１〜Ｃ１０のアルキル基、アルケニル基、アリール基、又はアルコキシ基を示し、ｎは１〜１０の整数を示す。］

[In the general formula (1), R ₁ represents a hydrogen atom or a methyl group, and R ₂ and R ₃ represent a hydrogen atom, a C1-C10 alkyl group, an alkenyl group, an aryl group, or an alkoxy group, respectively. , N represents an integer of 1-10. ]

  Examples of the charge control resin for controlling the developer to be positively charged include a polymer compound having a quaternary ammonium salt in the side chain.

  These charge control resins are contained in the toner particles in an amount of 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin. Is obtained.

  The MI of the developer of the present invention is preferably 1-40. A more preferable range is 3 to 35, and a further preferable range is 5 to 30.

  When MI is smaller than 1, the image gloss necessary for the full-color image forming method which is one of the objects of the present invention is poor. On the other hand, when MI exceeds 40, the developer layer thickness regulating member or the like may be contaminated depending on severe conditions such as a durability test at a high speed process speed in a high temperature and high humidity environment.

  The MI in the present invention is measured according to the method B of JIS K 7210, and the value at a test temperature of 135 ° C. and a test load of 1.20 kgf is taken as the MI value.

  The developer of the present invention must contain 1 to 30 parts by weight of a release agent with respect to 100 parts by weight of the binder resin constituting the toner particles. More preferably, the content is 2 to 20 parts by mass. The developer of the present invention is a developer that is optimally matched to the non-magnetic one-component development system, and a release agent is an essential component for assisting the fixing property at a high process speed. In addition, since the state of the release agent on the surface of the toner particles is determined by controlling the dispersion state of the release agent in the binder resin, the degree of aggregation of the developer is controlled by an approach based on toner particle properties. In order to do so, a release agent is an essential component.

  When the amount of the release agent is less than 1 part by mass, the values of the degree of aggregation and the degree of aggregation after shaking of the present invention tend to be small, it is difficult to control the desired flow characteristics, and the agitation and charging properties are poor.

  When the amount of the release agent exceeds 30 parts by mass, the amount of the release agent present on the toner particle surface tends to increase, and the cohesion degree and the post-shaking aggregation degree value tend to increase, which is essential in the present invention. Stirability and chargeability cannot be obtained.

  In addition, the endothermic peak in the differential thermal analysis of the release agent is preferably 40 ° C. to 120 ° C. from the viewpoint of controlling the fixing property and cohesiveness, and a more preferable range is 45 ° C. to 110 ° C.

  Further, the developer of the present invention preferably contains two or more types of release agents having different melting points in order to control the fixing property, the cohesiveness and the charging property in a balanced manner.

  Release agents that can be used in the developer according to the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof according to the 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.

  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 developer according to the present invention preferably has an average circularity of 0.950 or more and a circularity standard deviation of 0.045 or less. More preferably, the average circularity is 0.970 or more and the circle lightness standard deviation is 0.04 or less.

  A developer having an average circularity of less than 0.950 is not preferable because durability at a high process speed is weak against mechanical stress inside the developing device, such as the edge portion of the toner being scraped, and the deterioration of the developer is promoted. When the circularity standard deviation is larger than 0.04, the charge distribution tends to spread, and the fog tends to deteriorate.

  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 obtained.

  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. Although the toner according to the present invention can be produced by a pulverization method, the toner particles obtained by this pulverization method are generally indefinite shape, and the average circularity which is a preferable requirement of the present invention is 0.95. In order to obtain the above physical properties, it is necessary to perform mechanical / thermal or some special treatment.

  Therefore, in order to solve the above-described problems, in the present invention, it is preferable to produce toner particles by a polymerization method. Examples of the toner polymerization method include a direct polymerization method, a suspension polymerization method, an emulsion polymerization method, an emulsion association polymerization method, and a seed polymerization method. Among these, the balance between the particle size and the 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, the monomer composition is dispersed in a continuous layer containing a dispersion stabilizer (for example, an aqueous phase) using a suitable stirrer and simultaneously subjected to a polymerization reaction to obtain a toner having a desired particle size. To get. Since the toner obtained by this suspension polymerization method (hereinafter, polymerized toner) has individual toner particle shapes that are substantially spherical, it is easy to obtain a toner that satisfies the physical property requirement that the average circularity is 0.950 or more. Further, such a toner has high development characteristics because the distribution of charge amount is relatively uniform.

  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.

  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 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 Co., 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.

  The developer of the present invention contains inorganic fine powder as a necessary component for the purpose of highly controlling the degree of aggregation and the amount of charge, and the purpose of protecting the surface of the toner particles and suppressing the deterioration of the developer due to durability.

  In order to obtain the developer flow characteristics and charging characteristics required in the present invention, it is necessary to control the toner particles to some extent, but it is also highly controlled by the type, amount and formulation of the inorganic fine powder covering the toner particle surface. it can.

  As the inorganic fine powder added to the toner of the present invention, composite oxides such as silica, alumina, titania and hydrotalcite can be used.

  The average primary particle diameter of the inorganic fine powder is generally from the viewpoint of imparting functionality to add a plurality of arbitrary particles having a particle size of 4 to 700 nm. This is a preferred mode of use in which the degree of aggregation and charging characteristics can be uniformly controlled.

  More preferably, the main silica particles of 4 to 40 nm, more preferably 6 to 35 nm are added in an amount of 0.2 to 3% by mass, and other particles having an arbitrary particle size for the purpose of more precisely controlling fluidity and chargeability. It is preferable to add a fine powder.

Examples of silica include both the so-called dry process produced by vapor phase oxidation of silicon halides or dry silica called fumed silica, and so-called wet silica produced from water glass and the like. However, dry silica having less silanol groups on the surface and inside the silica fine powder and less production residue such as Na ₂ O, SO ₃ ²⁻ is more preferable. 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.

In particular, for the purpose of adjusting the degree of aggregation and the degree of aggregation after shaking, which are the most important parameters in the present invention, the average primary particle diameter exceeds 30 nm (preferably the specific surface area is less than 50 m ² / g), more preferably the primary grains. It is also one of preferred modes to further add inorganic or organic fine particles having a diameter of 50 nm or more (preferably having a specific surface area of less than 30 m ² / g). For example, hydrotalcite, titanium oxide, alumina, spherical silica particles, spherical polymethylsilsesquioxane particles, spherical resin particles and the like are preferably used.

  The inorganic fine powder is also preferably imparted with functions such as adjustment of the charge amount of the developer and improvement of environmental stability by a treatment such as hydrophobization.

  As the hydrophobic treatment agent for inorganic fine powder, 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 can be used alone. Or you may process together.

  The average primary particle size of the inorganic fine powder is a photograph of the toner magnified by a scanning electron microscope, and is further mapped by the element contained in the inorganic fine powder by an elemental analysis means such as XMA attached to the scanning electron microscope. In comparison with the photograph of the toner, 100 or more primary particles of the inorganic fine powder adhered to or released from the surface of the toner particles are measured, and the number average diameter is obtained.

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

  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; anti-caking agents; and organic fine particles and inorganic fine particles of opposite polarity can be used in small amounts as a developability improver. These additives can also be used after hydrophobizing the surface.

  Next, embodiments relating to an image forming method and a developing device unit according to the present invention will be described with reference to the drawings. The embodiments described below illustrate the present invention by way of example. The dimensions, materials, shapes, relative arrangements, and the like of the components described below are not particularly specified unless otherwise specified. However, the scope of the present invention is not limited thereto.

  FIG. 4 is a schematic cross-sectional view of an image forming apparatus and a developing device for carrying out the image forming method according to the present invention.

  The image forming apparatus A according to the present embodiment is formed by a laser beam printer that forms an image on a transfer material 6 such as a recording sheet or an OHP sheet by electrophotography in accordance with image information.

  Further, in the image forming apparatus A of the present embodiment, the process cartridge B is detachable as will be described in detail later.

  The image forming apparatus A is used by being connected to a host 14 such as a personal computer.

  The controller unit 34 processes a print request signal and image data from the host 14 and controls the scanner 3 as an exposure unit, thereby forming an electrostatic latent image on the photosensitive drum 1 as an image carrier.

The photosensitive drum 1 is uniformly charged by a roller-shaped charging member that is in pressure contact with the photosensitive drum 1, that is, a DC contact charging roller (charging roller) 2 as charging means.
A DC voltage fixed to a predetermined value as a charging bias is applied to the charging roller 2, and when negatively charged toner is used on the surface of the photosensitive drum 1, positively charged toner is placed on the negative side of the developing bias. When used, it is charged uniformly on the positive side of the developing bias.

  The charging roller 2 is driven to rotate in the direction of arrow D in the figure by the rotation of the photosensitive drum 1.

  The charging roller 2 is in contact with the entire length of the photosensitive drum 1 (a direction orthogonal to the transfer direction of the transfer material 6) over substantially the entire region.

  The uniformly charged photosensitive drum 1 is exposed by laser light from a scanner 3 as exposure means, and an electrostatic latent image is formed on the surface thereof.

The scanner 3 includes a laser light source, a polygon mirror, a lens system, and the like, and can scan and expose the photosensitive drum 1 under the control of the controller unit 34.
Thereafter, the electrostatic latent image is visualized as a toner image by supplying a developer by the developing device 4.

  That is, the developing device 4 includes a developing container 21 that stores a negatively charged nonmagnetic toner (toner) 22 as a one-component developer.

  A part of the developing container 21 facing the photosensitive drum 1 is opened over substantially the entire longitudinal direction of the photosensitive drum 1, and a roller-shaped developer carrier (developing means) is formed in the opening. A developing roller 23 is disposed.

  The developing roller 23 is pressed and brought into contact with the photosensitive drum 1 located on the upper left side of the developing device 4 in the figure so as to have a predetermined intrusion amount, and is driven to rotate in the direction of arrow A in the figure.

  Further, the surface has moderate irregularities in order to increase the probability of rubbing with the toner 22 and to carry the toner 22 well.

  An elastic toner supply roller 24 is in contact with the developing roller 23 as a means for supplying the developer to the developing roller 23 and stripping off the undeveloped toner from the developing roller 23.

  The toner supply roller 24 is rotatably supported by the developing container 21. The toner supply roller 24 is a sponge roller from the viewpoint of supplying toner to the developing roller 23 and stripping off undeveloped toner, and is driven to rotate in the direction indicated by arrow C in the figure, which is the same direction as the developing roller 23.

  Further, the developing device 4 includes a developing blade 25 as a developer layer thickness regulating member that regulates the amount of toner carried on the developing roller 23.

  The developing blade 25 is made of an elastic phosphor bronze metal thin plate, and is provided so that the vicinity of the free end side is in contact with the outer peripheral surface of the developing roller 23 in surface contact.

  The toner carried on the developing roller 23 by rubbing with the toner supply roller 24 is given a charge by frictional charging when passing through the contact portion with the developing blade 25 and is regulated to a thin layer.

  In the developing device 4 having such a configuration, a DC voltage fixed to a predetermined value as a developing bias is applied to the developing roller 23.

  Thus, in the present embodiment, the exposed portion on the surface of the uniformly charged photoreceptor drum 1 where the negative charge is attenuated is developed by reversal development.

  On the other hand, the transfer material 6 is separated and fed from the transfer material container 16 by a supply roller 12a and the like, and temporarily stops at the registration roller 12b.

  The registration roller 12b synchronizes the recording position of the transfer material 6 with the formation timing of the toner image on the photosensitive drum 1, and moves to a facing portion (transfer portion) between the transfer roller 5 serving as transfer means and the photosensitive drum 1. Then, the transfer material 6 is sent out.

  Thus, the visualized toner image on the photosensitive drum 1 is transferred to the transfer material 6 by the action of the transfer roller 5. The transfer roller 5 is connected to a transfer bias power source having a polarity opposite to that of the photoreceptor 1.

  The transfer material 6 onto which the toner image has been transferred is conveyed to the fixing device 9. Here, the unfixed toner image on the transfer material 6 is permanently fixed to the transfer material 6 by heat and pressure. Thereafter, the transfer material 6 is discharged out of the apparatus by a discharge roller 12c and the like.

  Further, untransferred toner remaining on the photosensitive drum 1 without being transferred is cleaned by a cleaning unit (cleaner) 11.

  That is, the cleaner 11 scrapes off the transfer residual toner from the photosensitive drum 1 by the cleaning blade 7 as a cleaning member and stores it in the waste developing container 8. The cleaned photosensitive drum 1 is used for image formation.

  In the present embodiment, the image forming apparatus A integrally forms an image carrier by the photosensitive drum 1 and a process unit acting on the image carrier into a cartridge so that the cartridge can be attached to and detached from the apparatus main body. Process cartridge system.

  Here, as the process means, charging means such as a charging roller 2 for charging the electrophotographic photosensitive member, developing means such as a developing roller 23 for supplying a developer to the electrophotographic photosensitive member, and a cleaning blade for cleaning the electrophotographic photosensitive member. 7 and other cleaning means are included.

  That is, the process cartridge is a charging unit, a developing unit, a cleaning unit, and an electrophotographic photosensitive member integrated into a cartridge, and the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus, or the charging unit, At least one of the developing means and the cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus.

  In the present embodiment, the photosensitive drum 1, the charging roller 2, the developing device 4, and the cleaner 11 are integrally formed into a cartridge to form a process cartridge B, which can be attached to and detached from the image forming apparatus main body 13.

  The process cartridge B is detachably mounted on the image forming apparatus main body 13 via mounting means (not shown) provided in the image forming apparatus main body 13.

  Further, the transfer material 6 is conveyed to the process cartridge B by the transfer material supply roller 12a, the registration roller 12b, the discharge roller 12c, and the transfer material 6 after the image formation is discharged from the image forming apparatus main body 13. For this purpose, a transfer material conveying means is configured.

  The developing process in the image forming method of the present invention may be performed in a non-contact manner even in a so-called contact one-component development method in which a toner carrier and a surface of a photosensitive member that is an electrostatic latent image carrier are in contact. The non-contact one-component development method in which the toner carrier is allowed to fly to the photosensitive member can be applied to both, and is not particularly limited. However, in order to maintain image quality over a long period even at a high process speed. The contact single component development system is more preferable.

  When the present invention is carried out by the contact one-component development 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, it is possible to employ 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.

  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.

  Here, the length in the rotation direction at the contact portion between the photosensitive member and the toner carrying member, 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 10 ² , 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 a developing blade, and this developing blade is in contact with the toner carrier via 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.

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.

  FIG. 5 shows a full-color laser beam printer in which a plurality of process cartridges are arranged to obtain a full-color image, and uses a transfer material conveyance belt E.

  Four process cartridges each containing four color toners of yellow, magenta, cyan, and black that can be attached to and detached from the image forming main body in the same form as the mono-color printer described in FIG. 4 (in this embodiment, in FIG. 5) , Y, M, C, and BK).

  Each of the process cartridges Y, M, C, and Bk includes photosensitive drums 201Y, 201M, 201C, and 201BK, charging rollers 202Y, 202M, 202C, and 202BK, developing containers 204Y, 204M, 204C, and 204BK, and transfer rollers 205Y, 205M, and 205C. , 205BK, cleaning blades 207Y, 207M, 207C, 207BK and developing rollers 223Y, 223M, 223C, 223BK.

  Among the configurations and operations of the process cartridges described above, the configurations and operations of the photosensitive drums 201Y, 201M, 201C, and 201BK, the charging rollers 202Y, 202M, 202C, and 202BK, the developing rollers 223Y, 223M, 223C, and 223BK are illustrated in FIG. Since this is the same as the mono color printer shown in FIG.

  The toner image formed on the surface of the photosensitive drum is sequentially laminated and transferred onto the transfer material conveyed by the transfer material conveyance belt E according to the arrangement order of the yellow, magenta, cyan, and black process cartridges, and then conveyed to the fixing device 212. The fixing device 212 heats and presses and fixes the image as a full-color image.

  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 charge control resin A)
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 83 parts, 10 parts of 2-ethylhexyl acrylate, and 7 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 = 28000 and Tg of about 76 ° C. The obtained sulfur-containing polymer is designated as charge control resin A.

[Example 1]
After adding 440 parts of a 0.1M Na ₃ PO ₄ aqueous solution to 360 parts of ion-exchanged water and heating to 57 ° C., using a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) at 12,000 rpm. Stir. To this, 36 parts of 1.0 M CaCl ₂ aqueous solution was added to obtain an aqueous medium containing calcium phosphate. Further, dilute hydrochloric acid was added to adjust the pH of the aqueous medium to 5.3.

on the other hand,
Styrene 82 parts n-Butyl acrylate 18 parts Carbon black 6.5 parts Charge control resin A 1 part Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 0.8 parts Saturated polyester 10 parts (acid value 10 mg KOH / g, peak (Molecular weight 11,000, Tg = 75 ° C.)
Ester wax (endothermic peak = 70 ° C.) 10 parts hydrocarbon wax (endothermic peak = 80 ° C.) 5 parts divinylbenzene 0.02 part The above formulation is heated to 57 ° C., and TK type homomixer (manufactured by Special Machine Industries) Was uniformly dissolved and dispersed at 6000 rpm. To this, 4.0 parts of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition is put into the aqueous medium and stirred at 12,000 rpm with a TK homomixer in an N ₂ atmosphere at an internal temperature of 57 ° C. to prepare the polymerizable monomer composition. Grained.

  Then, while stirring with a paddle stirring blade, NaOH was added to adjust the pH to 10 when 8 hours passed, and then the temperature was raised to 80 ° C. at a temperature rising rate of 40 ° C./h, and the reaction was performed for 5 hours. After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to adjust the pH to 1.2, and the mixture was stirred for 3 hours to dissolve the calcium phosphate salt.

  Thereafter, filtration, washing with ion-exchanged water, and drying were performed to obtain toner particles (1) having a weight average particle diameter of 6.5 μm.

  With respect to 100 parts of the toner particles (1), 1.7 parts of hydrophobic silica fine powder having an average primary particle diameter of 8 nm, which has been treated with hexamethyldisilazane and then with silicone oil, and hydrophobized having an average primary particle diameter of 400 nm. 0.2 part of talcite was mixed and dry-mixed with a Henschel mixer at a peripheral speed of 35 m / s for 5 minutes to obtain toner (1) of the present invention.

  Toner (1) had an average circularity of 0.991 and a circularity standard deviation of 0.027.

  Table 1 shows the physical property values of the toner.

  The toner (1) is a non-magnetic one-component developer (1), and the developer is filled in 300 g in the developing device (cartridge type) shown in FIG. 4 using an image forming apparatus as shown in FIG. Image evaluation is performed under high humidity conditions (temperature 30 ° C, humidity 80% RH), normal temperature and humidity conditions (temperature 23 ° C, humidity 50% RH) and low temperature low humidity conditions (temperature 15 ° C, humidity 10% RH) It was. The image forming apparatus will be described below.

FIG. 4 is a schematic diagram of a modified 1200 dpi laser beam printer (Canon: LBP-840) using a non-magnetic one-component contact developing type electrophotographic process. In this example, an apparatus in which the following parts (a) to (i) 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 tin oxide and titanium oxide powder dispersed in phenolic 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 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 the 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 device 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 190 mm / sec.
(I) As shown in FIG. 4, the main body was modified so that the cartridge could be installed in an inclined state.

  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 1.00 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). Print out 22,000 original images with a ratio of 2%, and output a solid white image, a solid image, an original halftone image, and a solid halftone potential image immediately after output of 22,000 copies, and fog evaluation and density Uniformity evaluation, dot reproducibility evaluation, and presence / absence of vertical streaks due to blade contamination were confirmed.

  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 a green filter 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% Above (including blotches and white spots)

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

(2) Image Density Uniformity A solid image was output, and the maximum density difference was obtained to evaluate the image density uniformity.

The image density was measured by 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

(3) Dot reproducibility An image of an isolated dot pattern having a small diameter (45 μm) as shown in FIG. 6 was printed out and the dot reproducibility was evaluated.
A: Less than 2 defects in 100, no scattering, and very uniform halftone is reproduced.
B: There are 3 to 5 defects in 100, almost no splattering is observed, and a uniform halftone image is reproduced.
C: 6 to 10 defects in 100 pieces, and there is a little scattering, but half-tone image quality that is generally not worrisome.
D: Poor halftone image quality with 11 or more defects in 100, severe splattering, and overall roughness.

(4) Image defects due to blade contamination In order to confirm the presence or absence of vertical streaks on the image due to blade contamination by visual evaluation based on the original halftone image and the presence or absence of streaks earlier and strictly, A halftone potential image is output and the presence or absence of vertical stripes is evaluated by visual confirmation.
A: Both the halftone image and the solid halftone potential image are good with no vertical stripes.
B: The original halftone image does not show any streaks, but the solid halftone potential image has a portion that looks slightly streaky when viewed closely. However, there is no problem with image quality.
C: Although it is difficult to see vertical stripes in the original halftone image, a clear vertical stripe is recognized in the halftone image of the solid image, and the image quality is slightly inferior.
D: Even in the original halftone image, white or black stripes are clearly noticeable in the vertical direction and cannot be used practically.

The toner (1) is the same as the initial image in which the image after the printout test of 22,000 sheets is free from fogging, and there is almost no missing dot or scattered toner outside the dot in all environments. High quality image quality was maintained.
Table 2 shows the evaluation results under each environment.

[Example 2]
The number of parts of the polymerization initiator to be added is changed from 4.0 parts to 3.5 parts, the adjustment temperature of the aqueous medium and the polymerizable monomer composition is changed from 57 ° C. to 60 ° C. The toner (2) was obtained and evaluated in the same manner as in Example 1 except that the temperature and time until the temperature was changed from 57 ° C. to 60 ° C. and from 8 hours to 5 hours. Good results were obtained.

[Examples 3 to 5]
Toners (3) to (5) were obtained and evaluated in the same manner as in Example 2 except that the pigment types to be added were changed as shown in Table 1, and as shown in Table 2, they were very good. Results were obtained.

Example 6
In Example 2, the toner (6) was obtained and evaluated in the same manner except that the added part of silica was changed to 1.5 parts and the added part of hydrotalcite was changed to 0.05 parts. Obtained.

Example 7
In Example 2, Toner (7) was obtained in the same manner except that the addition part of silica was 1.5 parts and 0.1 part of titanium oxide having an average primary particle size of 30 nm was added instead of hydrotalcite. When evaluated, generally good results were obtained.

Example 8
In Example 2, a toner (8) was obtained and evaluated in the same manner except that the amount of saturated polyester added was increased from 10 parts to 20 parts, and almost satisfactory results were obtained.

Example 9
In Example 2, a toner (9) was obtained and evaluated in the same manner except that the amount of the charge control resin A to be internally added was increased from 1 part to 2 parts. As a result, generally good results were obtained.

Example 10
In Example 2, a toner (10) was obtained and evaluated in the same manner except that the number of externally added hydrotalcite was changed from 0.2 part to 0.35 part. It was.

Example 11
In Example 2, the same procedure is performed except that the addition amount of divinylbenzene added as a crosslinking agent is changed to 0.25, and the wax species to be added is changed to a single system of 15 parts of ester wax (endothermic peak = 70 ° C.). As a result, toner (11) was obtained and evaluated. As a result, good results were obtained.

Example 12
In Example 2, a toner (12) was obtained and evaluated in the same manner except that the number of parts of Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) added as a charge control agent was changed to 1.6 parts. Although the coating state on the development carrier was slightly non-uniform due to excessive charging, generally good results were obtained.

Example 13
In Example 2, the wax species to be added was changed to a single system of 15 parts of ester wax (endothermic peak = 70 ° C.), and the charge control agent was added to Bontron E-88 (Orient Chemical Industry (without the charge control resin A) Toner (13) was obtained and evaluated in the same manner except that it was changed to a single system and the number of hydrotalcite added externally was changed to 0.1 part. .

Example 14
In Example 13, a toner (14) was obtained and evaluated in the same manner except that the crosslinking agent divinylbenzene was not added and the reaction temperature after granulation was changed to 63 ° C., and the result was generally good. .

Example 15
In Example 2, a toner (15) was obtained and evaluated in the same manner except that the type of wax to be added was changed to a single system of 25 parts of ester wax (endothermic peak = 70 ° C.). Although the state was good, the image quality was deteriorated due to slight blade fusion of the developer.

Example 16
Styrene-butyl acrylate copolymer (80/20) 100 parts carbon black (Regal 330: manufactured by Cabot Corp.) 10 parts low molecular weight polypropylene (Biscol 660P: manufactured by Sanyo Chemical Co., Ltd.) Melting point 145 ° C. 3 parts Bontron E-88 (Orient Chemical) Industrial Co., Ltd.) 1.8 parts The above components are melted and kneaded with a Banbury mixer, cooled, then finely pulverized with a jet mill, and further subjected to spheronization treatment using a surface reformer utilizing mechanical impact force. To obtain a spherical pulverized raw material. Next, the obtained pulverized raw material was classified by a classifier to obtain toner particles (16) having a weight average particle diameter of 8 μm. To 100 parts of the toner particles (16), 1.5 parts of a hydrophobic silica fine powder having an average primary particle diameter of 8 nm treated with hexamethyldisilazane and then with silicone oil, and an average primary particle diameter of 400 nm The toner (16) of the present invention was obtained by mixing 0.3 part of hydrotalcite and dry-mixing with a Henschel mixer at a peripheral speed of 35 m / s for 5 minutes.

  Toner (16) had an average circularity of 0.955 and a circularity standard deviation of 0.043.

  Table 1 shows the physical property values of the toner.

  When the toner (16) was evaluated as a nonmagnetic one-component developer in the same manner as in Example 1, generally good results were obtained.

Example 17
In Example 16, the styrene-butyl acrylate copolymer used was changed to one having a peak molecular weight of 15000, the addition amount of low molecular weight polypropylene was changed to 1.5 parts, spheroidizing treatment was not performed, and external addition was further performed. The toner (17) was obtained and evaluated in the same manner except that the amount of hydrotalcite added was changed to 0.1 part, and the developer stirring state was good throughout the durability. Along with the deterioration of the developer, the image quality due to the high temperature and high humidity environment tended to deteriorate slightly.

[Comparative Example 1]
In Example 3, the wax type to be added is a single system of 10 parts of ester wax (endothermic peak = 70 ° C.), and the charge control agent is Bontron E-88 (Orient Chemical Co., Ltd.) without adding the charge control resin A. Toner (18) was obtained and evaluated in the same manner except that the amount of divinylbenzene was changed to 0.2 parts and the number of silica parts added externally was changed to 1.5 parts. Due to the high fluidity of the developer, the developer cannot be charged enough during the development after being supplied onto the developer carrier, resulting in an image quality inferior in fog and dot reproducibility. It was.

[Comparative Example 2]
In Comparative Example 1, the amount of divinylbenzene added was changed to 0.3 part, the amount of hydrotalcite added externally was changed to 0.1 part, and titanium oxide having an average primary particle size of 30 nm was further changed to 0.0. The toner (19) was obtained and evaluated in the same manner except that 1 part was added, and the developer fluidity during stirring in the cartridge was high, so that sufficient transportability and frictional charging characteristics were insufficient, resulting in image quality. The result was dropped.

[Comparative Example 3]
The following materials were mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.).
・ Polyester resin 70 parts (oxidized 20 mgKOH / g, molecular weight 10,000)
30 parts of styrene-butyl acrylate-butyl maleate half ester copolymer (peak molecular weight: about 40,000, glass transition point Tg: 63 ° C.)
Carbon black (primary particle size 40 nm) 10 parts Benzyl acid aluminum iron complex 1.8 parts polyethylene 5 parts (molecular weight distribution = 1.08, DSC endothermic peak: 107 ° C)

  Subsequently, a twin-screw kneader (PCM) is used such that the barrel set temperature in the kneading section on the rearmost side of the screw extrusion kneader is T0 (° C.) = 110 ° C. and the melt kneader outlet temperature T1 = 150 ° C. -30 type, manufactured by Ikekai Tekko Co., Ltd.). The obtained kneaded material was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a developer crushed material. Next, the coarsely crushed material was finely pulverized with a collision-type airflow pulverizer, and then subjected to spheronization treatment using a surface modification device utilizing mechanical impact force to obtain a spherical pulverized raw material. Next, the obtained pulverized raw material was introduced into a multi-division classifier elbow jet classifier (manufactured by Nippon Steel Mining) and classified so as to obtain a desired particle size distribution, whereby toner particles (20) were obtained.

  With respect to 100 parts of the toner particles (20), 0.7 part of a hydrophobic silica fine powder having an average primary particle diameter of 8 nm treated with hexamethyldisilazane and then with silicone oil, and an average primary particle diameter of 30 nm The toner (20) of the present invention was prepared by mixing 0.7 part of titanium oxide and dry-mixing with a Henschel mixer at a peripheral speed of 35 m / s for 5 minutes.

  The average circularity of toner (20) was 0.955, and the circularity standard deviation was 0.043.

  Table 1 shows the physical property values of the toner.

  The toner (20) was evaluated as a non-magnetic one-component developer in the same manner as in Example 1. As a result, the rising property of charging in the developing device was insufficient, resulting in poor fog and dot reproducibility.

[Comparative Example 4]
In Example 13, the addition part of ester wax (endothermic peak = 70 ° C.) was changed to 30 parts, the divinylbenzene as a crosslinking agent was not added, the reaction temperature after granulation was changed to 65 ° C., and external addition The toner (21) was obtained and evaluated in the same manner except that the number of silica parts to be changed to 1.7 parts. As a result, the developer agglomeration was high, and the repeated agitation share was large, which promoted deterioration. There was a significant deterioration in image quality due to component contamination.

[Comparative Example 5]
Toner (22) was produced by the following emulsion aggregation method.

<< Preparation of Resin Particle Dispersion 1 >>
・ 90 parts of styrene ・ 20 parts of n-butyl acrylate ・ 3 parts of acrylic acid ・ 6 parts of dodecanethiol ・ 1 part of carbon tetrabromide The above mixture was dissolved and dissolved in a nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd. : Nonipol 400) 1.5 parts and anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 2.5 parts dissolved in 140 parts of ion-exchanged water were dispersed in a flask and emulsified. Then, while slowly mixing for 10 minutes, 10 parts of ion-exchanged water in which 1 part of ammonium persulfate was dissolved was added thereto, and after replacing with nitrogen, until the contents reached 70 ° C. while stirring the flask. The mixture was heated in an oil bath and emulsion polymerization was continued for 5 hours. Thus, a resin particle dispersion 1 was prepared by dispersing resin particles having an average particle size of 0.17 μm, a glass transition point of 57 ° C., and a weight average molecular weight (Mw) of 11,000.

<< Preparation of resin particle dispersion 2 >>
・ Styrene 75 parts ・ N-butyl acrylate 25 parts ・ Acrylic acid 2 parts Mix and dissolve 1.5 parts of nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and anionic interface Disperse 3 parts of the activator (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) in 140 parts of ion-exchange water in a flask, emulsify, and slowly mix for 10 minutes with ammonium persulfate. 10 parts of ion-exchanged water in which 0.8 part was dissolved were added, and after nitrogen substitution, the contents in the flask were heated with an oil bath until the contents reached 70 ° C. while stirring, and the emulsion polymerization was carried out for 5 hours. Continuously, a resin particle dispersion 2 was prepared by dispersing resin particles having an average particle size of 0.1 μm, a glass transition point of 61 ° C., and a weight average molecular weight (Mw) of 550,000.

<< Preparation of release agent particle dispersion >>
-Ester wax (melting point 65 ° C) 50 parts-Anionic surfactant 5 parts (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ Ion-exchanged water 200 parts or more was heated to 95 ° C. and dispersed using a homogenizer (IKA: ULTRA TALLAX T50), then dispersed with a pressure discharge homogenizer, and the average particle size was 0.5 μm. A release agent particle dispersion was prepared by dispersing a release agent.

<< Preparation of Colorant Particle Dispersion 1 >>
・ Carbon black 20 parts ・ Anionic surfactant 2 parts (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
-Ion exchange water 78 parts or more were mixed and dispersed using a sand grinder mill. When the particle size distribution in the colorant particle dispersion 1 was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the contained colorant particles was 0.2 μm and 1 μm. No coarse particles exceeding were observed.

<Preparation of charge control particle dispersion>
20 parts of a metal compound of di-alkyl-salicylic acid (charge control agent, Bontron E-88, manufactured by Orient Chemical Industries)
・ Anionic surfactant 2 parts (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
-Ion exchange water 78 parts or more were mixed and dispersed using a sand grinder mill. When the particle size distribution in this charge control particle dispersion was measured using a particle size measuring device (LA-700, manufactured by Horiba, Ltd.), the average particle size of the charge control particles contained was 0.2 μm, and 1 μm No larger coarse particles were observed.

<Preparation of liquid mixture>
-Resin particle dispersion 1 250 parts-Resin particle dispersion 2 110 parts-Colorant particle dispersion 1 50 parts-Release agent particle dispersion 70 parts 1 liter equipped with a stirrer, cooling tube and thermometer Was put into a separable flask and stirred. The mixture was adjusted to pH = 5.2 using 1N potassium hydroxide.

<Agglomerated particle formation>
As a flocculant, 150 parts of a 10% sodium chloride aqueous solution was added dropwise to this mixed solution, and the flask was heated to 57 ° C. while stirring the inside of the flask. At this temperature, 3 parts of resin particle dispersion 2 and 10 parts of charge control agent particle dispersion were added. After maintaining at 50 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles (A) having an average particle diameter of about 4.9 μm were formed.

<Fusion process>
Then, after adding 3 parts of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) here, the stainless steel flask was sealed and heated to 105 ° C. while stirring with a magnetic seal. And held for 3 hours. Then, after cooling, the reaction product was filtered, thoroughly washed with ion exchange water, and then dried to obtain toner particles (22).

  The obtained toner particles (22) had a weight average particle diameter of 5.5 μm, an average circularity of 0.971, and a circularity standard deviation of 0.035.

  To 100 parts of the toner particles (22), 1.5 parts of a hydrophobic silica fine powder having an average primary particle diameter of 8 nm treated with hexamethyldisilazane and then with silicone oil, and silica having an average primary particle diameter of 800 nm 0.1 parts of the particles were mixed and dry-mixed with a Henschel mixer at a peripheral speed of 35 m / s for 5 minutes to obtain a comparative toner (22).

  The toner (22) was evaluated in the same manner as in Example 1. As a result, the developer having such a high cohesion degree during durability tends to promote deterioration in the developing device of this configuration, and the high-speed process speed is achieved. I can't stand it.

[Comparative Example 6]
In Example 2, the addition amount of the charge control resin A is 2 parts, the addition amount of Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) is 1.5 parts, and the wax species to be added is ester wax (endothermic). (Peak = 70 ° C.) Toner (23) was obtained and evaluated in the same manner except that it was changed to a single system of 15 parts, silica added externally was changed to 1.5 parts, and hydrotalcite was changed to 0.4 parts. However, since the agglomeration degree during stirring in the developing device was too high, supply failure occurred when the developer amount in the latter half of the endurance decreased, and image defects called fatal white spots occurred. In addition, the solid image non-uniformity due to defective coating due to the large charge amount was also conspicuous.

Example 18
Next, use a machine that has been modified so that the process speed of the full-color color printer LBP2510 (manufactured by Canon) has been modified to 190 mm / sec, and the cartridge with an increased toner filling amount can be tilted backward as shown in FIG. [Toner Production Example 2], [Yellow Toner Production in Toner Production Example 3], [Magenta Toner Production in Toner Production Example 4], and [Toner Production Example 5] The endurance evaluation was performed according to Example 1 in which 300 g of cyan toner was filled in each corresponding cartridge, and 22,000 original full-color images having a printing ratio of 2% were printed out. As a result, as shown in Table 2, good image quality was maintained.

[Comparative Example 7]
In Example 18, full-color image durability evaluation was performed in the same manner as in Example 1 except that a machine modified so that the cartridge could be set horizontally was used. As shown in Table 2, the developer circulation was insufficient at a high process speed, and the deterioration of the developer was promoted. As a result, a fatal streak image due to blade fusion was generated.

It is a schematic sectional drawing of the developing device using the conventional nonmagnetic one-component developing system. 1 is a schematic configuration diagram illustrating an example of an apparatus that performs an image forming method of the present invention. It is the schematic of the apparatus used for the measurement of the triboelectric charge amount of the nonmagnetic developer in 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 explanatory drawing of the isolated dot pattern image for evaluating the resolution.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 Scanner 4 Developing device 5 Transfer roller 6 Transfer material 7 Cleaning blade 8 Waste developing container 9 Fixing device 11 Cleaner 12a Supply roller 12b Registration roller 12c Discharge roller 13 Image forming apparatus main body 14 Host 16 Transfer material accommodation Part 21 Developing container 22 Toner 23 Developing roller 24 Toner supply roller 25 Developing blade 26 Memory 32 CPU
33 ROM
34 Controller unit 71 Suction machine 72 Measuring container 73 Screen 74 Lid 75 Vacuum gauge 76 Air volume control valve 77 Suction port 78 Condenser 79 Electrometer 121 Developing roller 122 Developer 123 Developing blade 124 Toner supply roller 201Y, 201M, 201C, 201Bk Photoconductor Drum 202Y, 202M, 202C, 202BK Charging roller 203Y, 203M, 203C, 203BK Scanner 204Y, 204M, 204C, 204BK Development container 205Y, 205M, 205C, 205BK Transfer roller 207Y, 207M, 207C, 207BK Cleaning blade 212 Fixing device 213 Image Forming device main body 223Y, 223M, 223C, 223BK Developing roller A Image forming device B Process cartridge E Transfer conveyance base DOO Y, M, C, Bk process cartridge

Claims (16)

The latent electrostatic image carried on the latent image carrier is visualized by a developer filled in the developing device, and the visualized developer image is passed through the intermediate transfer member or not. An image forming method for transferring to a transfer material and fixing the developer image on the transfer material to the transfer material by a heating and pressing means,
The developing device includes a developer storage chamber having an opening for storing the developer;
A developing chamber connected to the developer containing chamber through the opening and transporting the developer from the developer containing chamber;
A developer carrying member disposed on the opposite side of the developing chamber from the opening and carrying the developer;
A developer regulating member that contacts the developer carrying member to regulate the amount of the developer on the developer carrying member;
A developer supply member that is disposed in contact with or in proximity to the developer carrier and that supplies the developer to the developer carrier while holding the developer;
The developer storage chamber is composed of two developer storage areas each having a stirring and conveying means,
The developer is transferred from the first developer storage region to the second developer storage region located above the first developer storage region by the stirring and conveying means,
The developer is transferred from the second developer containing area to the developing chamber located above the second developer containing area by the agitating and conveying means, and the developer overflowing from the developing chamber is transferred to the developing chamber. A developing device in which the developer circulates by being transferred from the second developer accommodating portion to the first developer accommodating portion;
The developer is a non-magnetic developer comprising toner particles having at least a binder resin, a colorant, and a release agent and an inorganic fine powder,
The nonmagnetic developer has a release agent content of 1 to 30 parts by weight per 100 parts by weight of the binder resin of the toner particles, the nonmagnetic developer has an aggregation degree G of 35 ≦ G ≦ 80, and an aggregation degree SG after shaking. 40 ≦ SG ≦ 85, and the ratio SG / G between the aggregation degree G and the post-shaking aggregation degree SG is 0.95 ≦ SG / G ≦ 1.50.   The aggregation degree G of the nonmagnetic developer is 40 ≦ G ≦ 75, the aggregation degree SG after shaking is 45 ≦ SG ≦ 80, and the ratio SG / G between the aggregation degree G and the aggregation degree SG after shaking The image forming method according to claim 1, wherein 1.00 ≦ SG / G ≦ 1.45.   3. The image forming method according to claim 1, wherein the non-magnetic developer has an initial frictional charge amount Qi of 30 ≦ Qi ≦ 70 and a frictional saturation charge amount Qf of 55 ≦ Qf ≦ 100.   3. The image forming method according to claim 1, wherein the friction initial charge amount Qi of the nonmagnetic developer is 35 ≦ Qi ≦ 65 and the friction saturation charge amount Qf is 60 ≦ Qf ≦ 90.   5. The image forming method according to claim 1, wherein the nonmagnetic developer contains a charge control agent and a charge control resin.   6. The image forming method according to claim 1, wherein the nonmagnetic developer has an MI of 1 to 40.   7. The image forming method according to claim 1, wherein the release agent contained in the nonmagnetic developer is a plurality of release agents having different melting points.   8. The image forming method according to claim 1, wherein the non-magnetic developer has an average circularity of 0.950 or more and a circularity standard deviation of 0.045 or less. A developing device for visualizing an electrostatic charge latent image carried on a latent image carrier with a developer filled in the developing device,
The developing device is connected to the developer accommodating chamber having an opening for accommodating the developer, and the developer accommodating chamber via the opening, and the developer is conveyed from the developer accommodating chamber. A developing chamber, a developer carrying member disposed on the opposite side of the developing chamber from the opening and carrying the developer, and a developer carrier on the developer carrying member in contact with the developer carrying member. A developer regulating member that regulates the amount of the developer, and a developer supply that is disposed in contact with or close to the developer carrying member and supplies the developer to the developer carrying member while holding the developer The developer storage chamber is composed of two developer storage areas each having a stirring and conveying means,
The developer is transferred from the first developer containing area to the second developer containing area located above the first developer containing area by the agitating and conveying means, and from the second developer containing area. The developer is transferred to the developing chamber located above the second developer containing area by the agitating and conveying means, and the developer overflowing from the developing chamber is transferred from the second developer containing portion, A developing device in which the developer circulates by being transferred to the first developer container;
The developer is a nonmagnetic developer comprising toner particles having at least a binder resin, a colorant and a release agent, and an inorganic fine powder, and the release agent content of the nonmagnetic developer is a binder resin of toner particles. 1 to 30 parts by mass per 100 parts by mass, the aggregation degree G of the non-magnetic developer is 35 ≦ G ≦ 80, the aggregation degree SG after shaking is 40 ≦ SG ≦ 85, the aggregation degree G and the shaking The developing device characterized in that the ratio SG / G to the post-aggregation degree SG is 0.95 ≦ SG / G ≦ 1.50.   The aggregation degree G of the nonmagnetic developer is 40 ≦ G ≦ 75, the aggregation degree SG after shaking is 45 ≦ SG ≦ 80, and the ratio SG / G between the aggregation degree G and the aggregation degree SG after shaking The developing device according to claim 9, wherein 1.00 ≦ SG / G ≦ 1.45.   11. The developing device according to claim 9, wherein the friction initial charge amount Qi of the nonmagnetic developer is 30 ≦ Qi ≦ 70 and the friction saturation charge amount Qf is 55 ≦ Qf ≦ 100.   11. The developing device according to claim 9, wherein an initial frictional charge amount Qi of the non-magnetic developer is 35 ≦ Qi ≦ 65, and a friction saturation charge amount Qf is 60 ≦ Qf ≦ 90.   The developing device according to claim 9, wherein the nonmagnetic developer contains a charge control agent and a charge control resin.   14. The developing device according to claim 9, wherein the nonmagnetic developer has an MI of 1 to 40.   15. The developing device according to claim 9, wherein the release agent contained in the nonmagnetic developer is at least two types of release agents having at least different melting points.   16. The developing device according to claim 9, wherein the nonmagnetic developer has an average circularity of 0.950 or more and a circularity standard deviation of 0.045 or less.

Images