JP2005321589A - Toner and image forming method using the toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy high definition even in an image forming apparatus having a small-diameter spot exposure means corresponding to high image quality and having an intermediate transfer body that is miniaturized and accelerated. It is an object to provide a toner capable of stably forming an image. More specifically, it is an object of the present invention to provide a toner having dot reproducibility that is quick and faithful to an electrostatic latent image regardless of the output of a large number of images and environmental changes.
SOLUTION: A toner containing at least a binder resin, a colorant, and a wax, and a due time of 3.0 to 10.0 ms when 3000 toners are measured with a particle charge amount distribution measuring apparatus by a laser Doppler method. In the q / d distribution represented by the toner charge amount q (femto-C) and the toner particle size d (μm). The absolute value of the peak top value of the peak is in the range of 0.20 to 0.80 (femto-C / μm), and the half width of the main peak in the q / d distribution is 0.10 to 0.40 (femto− C / μm).
[Selection figure] None

Description

  The present invention relates to a toner used in an image forming method such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and a toner jet method, particularly a toner suitable for oilless fixing, and an image forming method using the toner. It is about.

  In recent years, electrophotographic image forming apparatuses such as copying machines and laser beam printers have been strictly pursued in size, light weight, high speed, high image quality, and high reliability. Is becoming more sophisticated. In recent years, demands for full-color image output have increased rapidly due to various needs, and further higher image quality and higher resolution are desired.

  Since toner used in a full-color image forming apparatus is important for color reproducibility and transparency of an OHP image, the toner of each color in the fixing process needs to have good meltability and color mixing properties, and has a softening point. It is preferable to use a toner having a low sharp viscosity and a high sharp melt property. However, such a toner having high sharp melt property generally has a high affinity with the fixing roller, and tends to cause a so-called offset phenomenon in which melted toner adheres to the fixing roller during fixing.

  Conventionally, for the purpose of preventing this offset phenomenon, a liquid having high releasability such as silicone oil has been applied to the roller surface. However, this method has a problem that not only a complicated oil supply device for applying oil to the roller is required, but also the silicone oil adheres to paper and OHP, which makes the user uncomfortable.

  Therefore, a method of adding a wax such as low molecular weight polyethylene or low molecular weight polypropylene to the toner has been proposed from the idea of supplying an offset prevention liquid from the toner instead of supplying oil without heating.

  In addition to normal paper and OHP as full-color transfer materials, there is an increasing need to develop various materials on cardboard, card, postcard and other small-size paper. It is becoming effective. In a system that normally uses an intermediate transfer member, it is necessary to transfer the toner image from the electrostatic charge image carrier to the intermediate transfer member, and then transfer it again from the intermediate transfer member onto the transfer material. Therefore, it is necessary to increase the toner transfer efficiency more than before, and attempts have been made to bring the toner shape closer to a spherical shape by means such as mechanical impact force.

  Incidentally, the toner is charged by contact with a charging member such as a carrier or a blade, but the charge amount of the toner in each particle varies. The variation in the toner charge amount causes a variation in developability. In addition, toner with a low charge amount or toner having a reverse polarity charge is developed to the non-image area, causing not only fogging and waste of toner, but also causing toner scattering, smearing the image, Problems such as contamination occur. In order to solve such a problem, it is preferable that the toner charge amount has little variation, and toners that define the charge amount have also been proposed (see, for example, Patent Documents 1 and 2).

  In general, a semiconductor laser having an oscillation wavelength of 780 nm is used as the exposure means of a conventional electrophotographic apparatus. However, in order to meet users' strong demands for higher image quality in recent years, a blue semiconductor laser having a wavelength range of 400 to 500 nm, which is considered to be capable of obtaining a high-resolution image with a high recording density, is used as an exposure means. An image forming method has been proposed (see, for example, Patent Document 3).

JP 2001-255691 A JP 2003-149850 A Japanese Patent Laid-Open No. 5-19598

  However, when the conventional technology using the blue semiconductor laser as an exposure unit is applied to an image forming apparatus that is reduced in size and speeded up, a photosensitive drum (static charge) formed by an exposure unit with a small-diameter spot is used. Even if the electrostatic latent image with high resolution on the image bearing member) is faithfully developed to obtain a high-resolution toner image on the photosensitive drum, or even if it can be faithfully developed, the photosensitive drum It is difficult to faithfully transfer the upper high-resolution toner image to obtain a high-resolution toner image on the intermediate transfer member. The high resolution expected from the wavelength of the blue semiconductor laser There was a problem that sometimes it could not be achieved. Accordingly, the present invention provides an image satisfying high definition even in an image forming apparatus having a small-diameter spot exposure unit corresponding to high image quality and having an intermediate transfer body that is miniaturized and accelerated. It is an object of the present invention to provide a toner capable of stably forming a toner and an image forming method using the toner. More specifically, the present invention provides a toner having a rapid and faithful dot reproducibility with respect to an electrostatic latent image regardless of a large number of image outputs and environmental changes, and an image forming method using the toner. Let it be an issue.

In order to solve the above problems, a first invention according to the present application is a toner containing at least a binder resin, a colorant, and a wax, and measures 3000 toners with a particle charge amount distribution measuring apparatus by a laser Doppler method. Particles having a due time of 3.0 to 10.0 ms are in the range of 40 to 90% by number based on the total toner particles, and the toner charge amount q (femto-C) and the toner particle size. The absolute value of the peak top value of the main peak in the q / d distribution represented by d (μm) is in the range of 0.20 to 0.80 (femto-C / μm), and the main peak in the q / d distribution The half-value width of the toner is in the range of 0.10 to 0.40 (femto-C / μm). The second invention according to the present application is a toner in a flow type particle image measuring apparatus. When measured, particles having an equivalent circle diameter of 3 μm or more have an average circularity of 0.920 to 0.990, a circularity standard deviation of 0.010 to 0.050, and a mode circularity of 0.92 to 0.92. The toner according to the first aspect of the present invention is characterized in that a charging step for charging the electrostatic image carrier and a rotation speed of 2.0 s ^-1 or more. An electrostatic latent image is formed by irradiation with a semiconductor laser having a wavelength range of 350 to 500 nm on the electrostatic charge image carrier that is rotationally driven by the toner, and a toner from the developer carrier to the electrostatic latent image A development process for transferring the toner image, a transfer process for transferring the toner image developed on the electrostatic latent image to a transfer material via an intermediate transfer member, a fixing process for fixing the toner on the transfer material by heating, In a full-color image forming method having at least When the toner is a toner containing at least a binder resin, a colorant, and a wax, and 3000 toners are measured by a particle charge amount distribution measuring apparatus using a laser Doppler method, the due time is 3.0 to 10.0 ms. The main peak in the q / d distribution represented by the toner charge amount q (femto-C) and the toner particle diameter d (μm) is the range of particles in the range of 40 to 90% by number based on the total toner particles. The absolute value of the peak top value is in the range of 0.20 to 0.80 (femto-C / μm), and the half width of the main peak in the q / d distribution is 0.10 to 0.40 (femto-C). / Μm) in the image forming method.

  According to the present invention, even an image forming apparatus having a small-diameter spot exposure unit corresponding to high image quality and having an intermediate transfer body that is miniaturized and accelerated can output a large number of images. It is possible to provide a toner having rapid and faithful dot reproducibility with respect to an electrostatic latent image regardless of fluctuations, and an image forming method using the toner.

  As a result of intensive studies on a toner containing at least a binder resin, a colorant, and a wax, the present inventors have determined that the physical property value when the toner is measured with a particle charge amount distribution measuring apparatus by a laser Doppler method is within a certain range. Even if the image forming apparatus has a small-diameter spot exposure unit that supports high image quality, and has an intermediate transfer body that is miniaturized and speeded up, a large number of images can be output and environmental fluctuations can occur. Regardless, the present inventors have found that it is possible to reproduce dots quickly and faithfully with respect to the electrostatic latent image, thereby completing the present invention.

  Hereinafter, the present invention will be described in detail.

  The toner of the present invention is a toner containing at least a binder resin, a colorant, and a wax, and has a due time of 3.0 to 10 when 3000 toners are measured with a particle charge amount distribution measuring apparatus by a laser Doppler method. Particles in the range of 0.0 ms are in the range of 40 to 90% by number based on all toner particles, and q / d distribution represented by toner charge amount q (femto-C) and toner particle diameter d (μm). The absolute value of the peak top value of the main peak in the range of 0.20 to 0.80 (femto-C / μm), and the half width of the main peak in the q / d distribution is 0.10 to 0.40 ( femto-C / μm).

  In the present invention, E-SPART Analyzer MODEL EST-III ver. Is used as a particle charge amount distribution measuring apparatus by the laser Doppler method used for the above-mentioned due time measurement and q / d distribution measurement. 9.03 (trade name, manufactured by Hosokawa Micron Corporation) can be suitably used.

  The due time measured by the E-SPART Analyzer is a transit time (ms) of each toner particle at the intersection of two laser beams irradiated on the particle measurement part of the E-SPART Analyzer. In the E-SPART Analyzer, the particle diameter d (μm), the charge amount q (femto-C), and the due time (ms) can be measured for each toner particle, and when 3000 toners are measured based on this data. Q / d distribution and due time data are obtained. In the q / d distribution diagram, a value q / d obtained by dividing the charge amount q (femto-C) by the particle diameter d (μm) is calculated for each toner particle, and this is taken as the horizontal axis, and the vertical axis represents all toner particles. It is obtained by making the number% with reference to. The q / d distribution diagram shown in FIG. 1 is a schematic diagram of the q / d distribution of the negatively charged toner of the present invention obtained by the above measurement method. The q / d value at the peak top of the main peak and the half of the main peak. The value range is calculated as shown in the figure.

  As a result of diligent investigations on various toners, the present inventors output an image with an image forming apparatus having a small-diameter spot exposure unit corresponding to high image quality, and a compact and high-speed intermediate transfer member. The toner flying speed from the developing sleeve (toner carrier) to the photosensitive drum (electrostatic image carrier) and the toner flying speed from the photosensitive drum to the intermediate transfer member are constant between the toner particles. Rather, the flying speed has a certain distribution, and if there is an excessive difference in flying speed, the toner images formed on the photosensitive drum, the intermediate transfer member, and the transfer material are disturbed, for example, It has been found that it causes the roughness of the image. Further, by narrowing the distribution of the flying speed of the toner, even an image forming apparatus having a small-diameter spot exposure unit corresponding to high image quality, and having an intermediate transfer body that is miniaturized and accelerated. It has been found that, regardless of the output of a large number of images and environmental fluctuations, dot reproduction can be performed quickly and faithfully to the electrostatic latent image, and the image quality can be dramatically improved. Furthermore, by controlling the toner dwell time and the toner charge amount, it is possible to control the distribution of the flying speed of the toner, and as a result, there is an exposure means for a small-diameter spot corresponding to high image quality, and It has been found that even an image forming apparatus having an intermediate transfer body that is miniaturized and speeded up can dramatically improve image quality regardless of the output of a large number of images and environmental changes.

  The toner of the present invention is a toner containing at least a binder resin, a colorant, and a wax, and has a dwell time of 3.0 to 3.0 when 3000 toner particles are measured with a particle charge amount distribution measuring apparatus using a laser Doppler method. It is essential that the particles in the range of 10.0 ms are in the range of 40 to 90% by number based on the total toner particles. The toner in which the duel time is in the range of 3.0 to 10.0 ms is in the range of 40 to 90% by number based on the total toner particles is the toner of the present invention in a state where an electric field is applied from the outside. This means that the free fall speed is faster than that of the conventional toner, and the speed variation between the toner particles is narrow and uniform. This indirectly indicates that the toner particles are linearly moved without meandering or drawing a curve when the toner particles freely fall in a minute area. It can be said that the flying of the toner to the photosensitive drum and the flying of the toner from the photosensitive drum to the intermediate transfer body during transfer are linear without meandering or drawing a curve. Such a phenomenon is a behavior specific to the toner of the present invention, which is not seen in the conventional toner.

  As described above, the toner of the present invention is a toner that exhibits a specific flying behavior during development or transfer. The present inventors consider the reason for such a specific behavior as follows. In the conventional pulverization toner, since the toner manufacturing process of pulverization is performed, the toner particle surface has sharp protrusions and cracks which are pulverization marks, and the shape of the toner particles is also indefinite. is there. Even if such toner particles are spheroidized, the shape is somewhat close to a circle and the surface is only slightly smooth, and is basically indeterminate, and sharp protrusions and cracks remain on the particle surface. End up. When toners with such shape and particle surface uniformity fly at the time of development or transfer, for example, horizontally long or flat particles contained in toner particles, particles with large protrusions, particles with many protrusions In addition, particles with many cracks are subjected to great air resistance during flight, and therefore meander or curve when flying. On the other hand, a toner composition obtained by subjecting a toner composition directly to suspension polymerization in water, a toner obtained by agglomeration and association of a latex and a colorant obtained by emulsion polymerization, or a toner composition mainly composed of a polyester resin dissolved in a solvent In the case of a toner or the like in which a spherical object is suspended in water, the shape is very close to a sphere, there are no protrusions on the particle surface, and the surface is very smooth. As a result, the movement of the image forming apparatus, which has been reduced in size and increased in speed, is sensitive to the minute fluctuations in the electric field strength that tend to occur at the transfer site, resulting in meandering during flight. Or draw a curve. In contrast to these conventionally known toners, the toner of the present invention has a special feature in that the surface of the toner particles has very fine convex portions, and the entire surface of the toner particles does not have smooth and sharp protrusions. Because of its shape, it has a moderate air resistance during flight, a slow reaction to fine fluctuations in the electric field strength at the development site and transfer site, and exhibits a special behavior of flying linearly. Conceivable. Also, in order to obtain such a special particle shape, for example, it is manufactured by fixing and embedding submicron-sized fine particles such as resin particles and inorganic particles on the toner surface, and further coating the surface thinly with resin. be able to.

  Conventionally, various new technologies have been incorporated into image forming apparatuses. For example, a technology for reducing the diameter and increasing the speed of a cylindrical photosensitive drum in order to reduce the size of the image forming apparatus, a technology for providing an intermediate transfer member in the apparatus to cope with various transfer materials, and an apparatus Technology to heat and fix the wax-containing toner on the transfer material with a fixing device that does not have an application mechanism of liquid for preventing offset, for example, in order to cope with high image quality Various techniques have been incorporated into image forming apparatuses, such as a technique for using a blue semiconductor laser as a means for exposing small-diameter spots.

The relationship between the optical spot diameter and wavelength of the laser beam used as the exposure means is expressed by “spot diameter ∝ (π / 4) × (λ × f / d)” (λ: wavelength of the laser beam, f: fθ). The focal length of the lens, d: lens diameter), for example, by using a 420 nm semiconductor laser having a shorter wavelength compared to a conventional 780 nm semiconductor laser, the optical spot diameter can be reduced to about ½. It becomes possible. By using such a small-diameter spot exposure means, a fine electrostatic latent image can be easily obtained on the electrostatic image carrier, and an image with a greatly improved resolution can be obtained theoretically. By setting 21 to 21 μm, a resolution of 1200 dpi can be achieved, and by setting the spot diameter to 10.6 μm, a resolution of 2400 dpi can be achieved. (Note that the spot diameter of the laser beam referred to here is a continuous point having an intensity of 1 / e ² times the maximum intensity on the light intensity distribution expressed by a Gaussian function (e represents the base of natural logarithm). This means the diameter of the contour line, that is, the 1 / e ² diameter.)

  As described above, various new techniques have been introduced into the image forming apparatus, such as a technique for using a blue semiconductor laser as an exposure means for small-diameter spots. However, when these new technologies are combined, not all the merits of each single technology can be utilized. For example, in an image forming apparatus using a blue semiconductor laser that can reduce the spot diameter of a laser beam as an exposure unit, an electrostatic latent image formed on a small-diameter photosensitive drum that rotates at high speed is converted into dots. It is usually not easy to develop the toner faithfully, and as a result, it is impossible to improve the resolution as expected by the small diameter spot exposure means. Also, when a small-diameter photosensitive drum that rotates at high speed and an intermediate transfer body are combined, toner transfer from a small-diameter photosensitive drum that rotates at high speed and has a high bending rate to the intermediate transfer body is not always easy, If this is further combined with an exposure means for a small-diameter spot, the dot reproducibility deteriorates due to the combination, so the resolution is not improved as expected.

The present inventors examined these points in detail, and as a result of this combination, the tendency of image quality deterioration is that the rotational speed of the photosensitive drum at the time of electrostatic latent image formation is 2.0 s ⁻¹ or more (for example, the photosensitive drum When the diameter of the photosensitive drum is 25 mmΦ, the process speed is 157 mm / s or more, and when the diameter of the photosensitive drum is 20 mmΦ, the process speed is 126 mm / s or more. It was found that this phenomenon was more conspicuous when combined with a wavelength semiconductor laser, and when an intermediate transfer member was combined, the tendency of image quality to deteriorate was remarkable.

  Accordingly, the present inventors have studied an image forming apparatus having such a combination, and the image forming apparatus having such a configuration includes particles having a dwell time in the range of 3.0 to 10.0 ms. Is suitable in the range of 40 to 90% by number based on the total toner particles. By using this toner, the electrostatic latent image can be quickly generated regardless of the output of a large number of images and environmental fluctuations. It was found that faithful dot reproduction could be achieved and unprecedented high image quality could be achieved.

  The present inventors have further investigated a toner in which particles having a dwell time in the range of 3.0 to 10.0 ms are in the range of 40 to 90% by number based on all toner particles. As a result, the amount of charge varies, such as the movement of toner with a high charge amount is fast, the movement of toner with a low charge amount is slow, or the movement of toner with a large particle size is fast, but the movement of toner with a small particle size is slow. The difference in the flying speed of the toner derived from (distribution) and particle size variation (distribution) is large in the conventional toner, but all toner particles are particles in which the due time of the present invention is in the range of 3.0 to 10.0 ms. In the case of a toner in the range of 40 to 90% by number with respect to the toner, the balance between the toner charge amount distribution and the toner particle size distribution is maintained exquisitely, and variations in the flying speed of the toner are suppressed. The movement of toner during development and transfer is very smooth, excellent developability and transferability are exhibited regardless of environmental fluctuations, and it has a small-diameter spot exposure means that supports high image quality, and is downsized. Speeding up Even with an image forming apparatus having an intermediate transfer member, it is possible to reproduce dots quickly and faithfully to the electrostatic latent image regardless of the output of a large number of images and environmental fluctuations, thus satisfying high definition. It was revealed that an image can be formed stably.

  When the particles having a duel time in the range of 3.0 to 10.0 ms are less than 40% by number based on the total toner particles, it indicates that the toner has a wide distribution of duel time. There is a large variation between toner particles at a free-falling speed, and there is a large variation in the flying speed between toner particles, resulting in a large variation in toner and developing properties, such as poor dot reproducibility. Therefore, an image satisfying high definition cannot be stably formed. Conversely, when the number of particles having a duel time in the range of 3.0 to 10.0 ms is greater than 90% by number based on all toner particles, the toner has an excessively narrow duel time distribution. Although the dispersion between the toner particles at the speed at which the toner freely falls is very small, the balance between the charge amount distribution and the particle size distribution is lost, and the flying speed between the toner particles becomes rather large. In addition, toner components having an excessive charge amount or particle size, or toner components having an excessively small charge amount may cause uniform developability and transferability, for example, development unevenness in a low-humidity environment becomes noticeable, and toner scatters in a high-humidity environment. Deteriorates, leading to a decrease in image quality.

  The toner of the present invention is represented by the toner charge amount q (femto-C) and the toner particle size d (μm) when 3000 toners are measured by a particle charge amount distribution measuring apparatus by a laser Doppler method. The absolute value of the peak top value of the main peak in the q / d distribution is in the range of 0.20 to 0.80 (femto-C / μm), and the half width of the main peak in the q / d distribution is 0.10 to 10. It is essential to be in the range of 0.40 (femto-C / μm).

  When the absolute value of the peak top value of the main peak in the q / d distribution is less than 0.20 (femto-C / μm), fog is deteriorated due to insufficient charge amount of the toner, and toner is scattered. It becomes easy to do and causes in-flight contamination. On the contrary, if the absolute value of the peak top value of the main peak in the q / d distribution is larger than 0.80 (femto-C / μm), the charge amount becomes excessive, the image density becomes thin, the developing sleeve, etc. The toner is likely to adhere to the member that comes into contact with the toner, and image defects such as image stripes are likely to occur.

  In addition, when the half width of the main peak in the q / d distribution is less than 0.10 (femto-C / μm), uniform chargeability is good and an image with less fog is obtained in a room temperature and humidity environment. Although it is likely to occur, the charge amount distribution changes drastically when the environment changes greatly, such as in a low-temperature and low-humidity environment or a high-temperature and high-humidity environment, so that the image quality changes significantly and a stable image cannot be obtained. On the other hand, if it is larger than 0.40 (femto-C / μm), a toner having a very large difference in charge amount coexists, and there is a problem in dot reproducibility because the transfer efficiency of these toners is different. Due to frictional charging between the highly charged toner and the weakly charged toner, the charge of the highly charged toner is further increased, and the charge of the weakly charged toner is changed to the opposite polarity. Various problems such as fogging and a decrease in image density occur.

  The toner of the present invention is a toner whose dwell time and charge amount distribution are controlled, and particles whose dwell time is in the range of 3.0 to 10.0 ms are in the range of 40 to 90% by number based on all toner particles. In order to obtain a toner, it can be achieved by making the toner particles have a special shape that has very fine convex portions on the surface of the toner particles and that the entire surface of the toner particles does not have smooth and sharp protrusions. is there. In order to obtain such a special particle shape, for example, it can be produced by fixing and embedding submicron-sized fine particles such as resin particles and inorganic particles on the toner surface, and further coating the surface thinly with resin. it can. The resin particles that can be used in this case are not particularly limited and known ones can be used. For example, polystyrene having a weight average particle diameter of 0.2 to 0.7 μm obtained by emulsion polymerization, polymethyl methacrylate, and the like can be used. Polyacrylate, styrene-acrylic copolymer resin, etc., phenol resin, modified phenol resin, malee resin, alkyd resin, epoxy resin, unsaturated polyester, urea resin, melamine resin, urea-melamine resin, xylene resin, toluene resin, The weight average particle diameter of guanamine resin, melamine-guanamine resin, acetoguanamine resin, glyphtal resin, furan resin, silicone resin, polyimide, polyamideimide resin, polyetherimide resin, polyurethane resin, etc. is adjusted to 0.1 to 0.9 μm. Resin fine powder . Further, the inorganic particles that can be used are not particularly limited and known ones can be used. For example, calcium carbonate, hydroxyapatite, magnetite, hematite, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, The weight average particle size of strontium titanate, magnesium titanate, zinc oxide, tin oxide, manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, boron nitride, hydrotalcite, etc. is 0. An inorganic fine powder prepared to 1 to 0.9 μm can be mentioned. Further, the inorganic fine particles may be subjected to a hydrophobic treatment.

  The resin that can be used for coating the toner particle surface is not particularly limited as long as it is soluble in a solvent and is thermoplastic, and known materials can be used. For example, polystyrene, poly-p -Chlorostyrene, polyvinyltoluene, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-maleic acid ester copolymer, styrene-acrylic acid copolymer, Styrene-methacrylic acid copolymer, styrene-maleic acid copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer Polymer, styrene-vinyl methyl ketone copolymer, steel -Butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, polyvinyl acetate, silicone resin, polyester resin, polyurethane resin, polyamide resin, polycarbonate resin, polyarylate resin, epoxy resin, xylene Examples thereof include resins, polyvinyl butyral resins, and petroleum resins. From the viewpoint of low-temperature fixability, it is preferable to use a resin that melts at a relatively low temperature as the coating material, and polyester resin, styrene-acrylic resin, and the like used as the binder resin for the toner are suitable as the coating material for the toner particle surface. These are used alone or in combination.

  The toner charge amount distribution is controlled so that the absolute value of the peak top value of the main peak in the q / d distribution is in the range of 0.20 to 0.80 (femto-C / μm). To make the toner whose main peak half-width is in the range of 0.10 to 0.40 (femto-C / μm), the presence state of the charge control agent is controlled so that it is closer to the toner surface than inside the toner. This can be achieved by the presence of a charge control agent. In order to obtain such a charge control agent, for example, an aluminum 3,5-di-t-butylsalicylate compound is added to 100 parts by mass of the binder resin as the charge control agent contained in the toner particles. 0.1 to 3 parts by mass of the charge control agent is used, and when the toner particle surface is thinly coated with resin, 0.01 to 1 part by mass of the charge control agent is present in the coating material on the toner particle surface. As a result, a larger amount of charge control agent can be present in the vicinity of the toner particle surface than in the toner. Further, if the charge control agent existing near the toner surface has a higher chargeability than the charge control agent present inside the toner, the absolute value of the peak top value of the main peak in the q / d distribution or the main peak For example, when a 3,5-di-t-butylsalicylic acid aluminum compound is present inside the toner, as a charge control agent on the toner particle surface, zirconium 3,5-di-t-butylsalicylate Compounds are preferably used.

  The toner of the present invention has an average circularity of 0.920 to 0.990 and a circularity standard deviation of 0.010 to 0 when particles having an equivalent circle diameter of 3 μm or more are measured with a flow type particle image measuring device. .050, and the mode circularity is preferably 0.92 to 0.99. The average circularity, circularity standard deviation, and mode circularity of the toner can be measured using a flow type particle image measuring device “FPIA-2100” (trade name, manufactured by Sysmex Corporation) as described later. it can.

  When the average circularity is less than 0.920 or the mode circularity is less than 0.92, the external additive deteriorates when a large number of images are output, resulting in insufficient transferability. On the contrary, if the average circularity is larger than 0.990 and the mode circularity is larger than 0.99, the shape of the toner particles becomes too spherical. At this time, untransferred toner may pass through the cleaning blade, which may cause image defects due to poor cleaning.

  Further, when the circularity standard deviation is less than 0.010, the toner is easily packed in the toner container or the developing device, and the toner forms an aggregate causing image defects, or the solid image is uniform. If the ratio is larger than 0.050, toner with low circularity and high toner coexist, and the transferability of these toners is different. Transfer defects such as the above may occur.

  The means for adjusting the average circularity, the circularity standard deviation, and the mode circularity of the toner of the present invention is not particularly limited, and examples thereof include a method in which toner particles produced by a pulverization method are made spherical by a mechanical impact method. It is done. Known devices are used as the mechanical impact method described above. For example, a hybridizer manufactured by Nara Machinery Co., Ltd., a mechanofusion system manufactured by Hosokawa Micron Co., a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., and Nisshin Engineering Co., Ltd. There are super rotors made of steel.

  By controlling the average circularity of the toner of the present invention and reducing the variation in shape, the rising characteristics of charging can be improved and the charge amount distribution can be moderately sharpened. Even if a large number of sheets are output, stable image quality can be maintained and image quality can be improved.

  The toner of the present invention contains at least a binder resin.

  As the binder resin contained in the toner of the present invention, those conventionally used for toners are used, and vinyl copolymers represented by styrene- (meth) acrylic copolymers, polyester resins, vinyl Various resins such as a hybrid resin in which a system copolymer unit and a polyester unit are chemically bonded, an epoxy resin, and a styrene-butadiene copolymer can be used.

  When a polyester resin or a hybrid resin having a polyester unit is used as the binder resin contained in the toner of the present invention, a polyhydric alcohol and a polyvalent alcohol are used as a polyester monomer for forming the polyester resin or the polyester unit of the hybrid resin. A monovalent carboxylic acid, a polyvalent carboxylic acid anhydride, a polyvalent carboxylic acid ester, or the like can be used as a raw material monomer. Specifically, for example, as the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Bisphenol A alkylene oxide adducts such as bis (4-hydroxyphenyl) propane and polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1 , 2-Propylene glycol, 1,3-propylene glycol, 1,4-butanediol Neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

  Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Can be mentioned.

  Examples of the divalent carboxylic acid component include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyldicarboxylic acids such as succinic acid, dodecenyl succinic acid, adipic acid, sebacic acid and azelaic acid, or anhydrous And succinic acid substituted with an alkyl group having 6 to 12 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, and citraconic acid, or anhydrides thereof.

  Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (also known as trimellitic acid), 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, Examples include 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof.

  Among the above, in particular, a bisphenol derivative represented by the following general formula (1) as a diol component, a carboxylic acid component (for example, a divalent or higher carboxylic acid or acid anhydride thereof, or a lower alkyl ester thereof) , Fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component, and polyester resins obtained by condensation polymerization of these are particularly preferable. The polyester resin having this composition has good charging characteristics.

  When a vinyl resin or a hybrid resin having a vinyl copolymer unit is used as the binder resin contained in the toner of the present invention, a vinyl copolymer or a vinyl copolymer unit of the hybrid resin is generated. The following can be used as the vinyl monomer for the purpose. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3, Styrene and its derivatives such as 4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; styrene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated such as butadiene and isoprene Polyenes; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl Vinyl halides such as vinyl halide; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n methacrylate -Α-methylene aliphatic monocarboxylic acid esters such as octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, acrylic acid Ethyl, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic acid 2 Acrylic esters such as chloroethyl and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl compounds such as N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  Furthermore, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Unsaturated dibasic acid half esters such as alkenyl succinic acid methyl half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester; dimethyl maleic acid, dimethyl fumaric acid and the like; acrylic acid, meta Α, β-unsaturated acids such as rillic acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group, such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof. Further, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

  When a hybrid resin having a vinyl copolymer or a vinyl copolymer unit is used as the binder resin to be included in the toner of the present invention, these resins are crosslinked with a crosslinking agent having two or more vinyl groups. It may be. The following are mentioned as a crosslinking agent used in this case. Examples of aromatic divinyl compounds include divinylbenzene and divinylnaphthalene; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, and 1,4-butanediol di Examples include acrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate, and acrylates of the above compounds replaced with methacrylate; linked by alkyl chains containing ether linkages. Examples of the diacrylate compounds include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and polyethylene glycol # 400 diacrylate. Acrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and acrylates of the above compounds in place of methacrylate; diacrylate compounds linked by a chain containing an aromatic group and an ether bond, for example, Polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and acrylates of the above compounds The thing replaced with a methacrylate is mentioned. Other polyfunctional crosslinking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; Examples include allyl cyanurate and triallyl trimellitate.

  Examples of radical polymerization initiators used for producing a vinyl resin or a hybrid resin having a vinyl copolymer unit include 2,2′-azobisisobutyronitrile and 2,2′-azobis. (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2, 2'-azobisisobutyrate, 1,1'-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2'-azobis (2,4,4-trimethylpentane) 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2,2′-azobis (2-methyl-propane), methyl ethyl ketone Ketone peroxides such as oxide, acetylacetone peroxide, cyclohexanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3- Tetramethylbutyl hydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl Peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate Di-2-ethylhexyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxy Butyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxyneodecanoate, t-butylperoxy-2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy- - ethylhexanoate, di -t- butyl peroxy hexahydro terephthalate, di -t- butyl peroxy azelate and the like.

  In the toner of the present invention, the molecular weight distribution measured by gel permeation chromatography (GPC) has a peak molecular weight (Mp) of the binder resin component soluble in tetrahydrofuran (THF) contained in the toner of 4000 to 50000. It is preferable to be in the range. When the Mp of the resin component contained in the toner is less than 4000, there are problems in storage stability of the toner, high temperature offset resistance is insufficient, and fusion and filming to the photosensitive drum occur. May be easier to do. On the other hand, if Mp exceeds 50,000, the low-temperature fixability may be insufficient, the image gloss may be too low, or a problem may occur in color mixing.

  The toner of the present invention contains at least a colorant.

  For example, as a colorant for cyan toner, C.I. I. Pigment blue 2,3,15: 1,15: 2,15: 3,16,17, C.I. I. Acid Blue 6, C.I. I. Examples thereof include Acid Blue 45 or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton.

  Examples of the color pigment for magenta toner include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209, 238, C.I. I. Pigment violet 19, C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Further, as a dye for magenta toner, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121, C.I. I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27, C.I. I. Oil-soluble dyes such as Disperse Violet 1; I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, C.I. I. Basic violet 1,3,7,10,14,15,21,25,26,27,28 etc. are mentioned.

  Examples of the color pigment for yellow toner include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 93, 97, 155, 180, C. I. Vat yellow 1, 3, 20 etc. are mentioned.

  Examples of the colorant for black toner include carbon black, acetylene black, lamp black, graphite, iron black, aniline black, and cyanine black.

  The amount of the colorant used is 1 to 15 parts by mass, preferably 3 to 10 parts by mass, with respect to 100 parts by mass of the binder resin, from the balance between the reproducibility of the intermediate color and the coloring power.

  When the content of the colorant is more than 15 parts by mass, the transparency is lowered, and in addition, the reproducibility of intermediate colors as typified by human skin color is likely to be lowered, and further, the charging property of the toner is stabilized. And the target charge amount is difficult to obtain. Further, when the content of the colorant is less than 1 part by mass, it is difficult to obtain the desired coloring power and it is difficult to obtain a high-quality image with a high image density.

  The toner of the present invention contains at least a wax.

  Examples of the wax that can be contained in the toner of the present invention include the following. Oxides of aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer wax, microcrystalline wax, Fischer-Tropsch wax, paraffin wax, and oxidized hydrocarbon wax Or block copolymers thereof; waxes mainly composed of fatty acid esters such as carnauba wax and montanic acid ester wax; esters that are a synthetic reaction product of higher fatty acids such as behenyl behenate and behenyl stearate and higher alcohols Examples thereof include waxes and fatty acid esters such as deoxidized carnauba wax which are partially or fully deoxidized.

  Further, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol , Saturated alcohols such as melyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis laurin Saturated fatty acid bisamides such as acid amides and hexamethylene bis stearic acid amides; ethylene bis oleic acid amides, hexamethylene bis oleic acid amides, N, N ′ dioleyl adipic acid amides, N, N ′ diacids Unsaturated fatty acid amides such as rail sebacic acid amides; Aromatic bisamides such as m-xylene bisstearic acid amide and N, N ′ distearyl isophthalic acid amides; Calcium stearate, calcium laurate, zinc stearate, magnesium stearate Aliphatic metal salts such as those commonly referred to as metal soaps; waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides and the like Examples include partially esterified products of polyhydric alcohols; methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils and the like.

  In order to achieve excellent low-temperature fixability, high coloring power, clear color and color mixing, and excellent environmental stability and durability, in the endothermic curve in the differential thermal analysis (DSC) measurement of the wax, The peak temperature of the maximum endothermic peak is preferably in the range of 60 to 105 ° C, and more preferably in the range of 70 to 90 ° C. When the temperature is lower than 60 ° C., for example, the storage stability of the toner may be inferior, and when the temperature exceeds 105 ° C., it may be difficult to perform low-temperature fixing desired from the viewpoint of energy saving.

  The wax is used in an amount of 1 to 20 parts by mass, preferably 2 to 15 parts by mass, per 100 parts by mass of the binder resin. If the amount is less than 1 part by mass, there is no effect on the low-temperature fixability, and if it exceeds 20 parts by mass, there may be a problem in storage stability and developability of the toner.

  The toner of the present invention has one or a plurality of endothermic peaks in the temperature range of 30 to 200 ° C. in the endothermic curve in DSC measurement, and the peak temperature of the maximum endothermic peak is in the range of 60 to 105 ° C. Preferably, it is in the range of 70 to 90 ° C. If the peak temperature of the maximum endothermic peak is within this range, the balance between excellent low-temperature fixability and developability will be good. When the peak temperature of the maximum endothermic peak is less than 60 ° C., the storage stability of the toner may be inferior, and when it exceeds 105 ° C., it may be difficult to perform low-temperature fixing desired from the viewpoint of energy saving. The peak temperature of the maximum endothermic peak can be set to 60 to 105 ° C. by adding the wax having the maximum endothermic peak peak temperature of 60 to 105 ° C. described above to the toner.

  The toner of the present invention can contain a charge control agent. As the charge control agent that can be used, a known charge control agent can be used, and in particular, a charge control agent that has a high charging speed and can stably maintain a constant charge amount is preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, naphthoic acid, dicarboxylic acid, polymer compounds having sulfonic acid or carboxylic acid groups in the side chain, boron compounds, urea A compound, a silicon compound, calixarene, etc. are mentioned. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, and an imidazole compound.

Among the above, the charge control agent that is particularly preferably used is an aromatic carboxylic acid derivative selected from aromatic oxycarboxylic acid and aromatic alkoxycarboxylic acid, and a metal compound of the aromatic carboxylic acid derivative. It is preferable that it is more than the value. The metal compound of the aromatic carboxylic acid is prepared by, for example, dropping an aqueous solution in which a divalent or higher valent metal ion is dissolved into an aqueous sodium hydroxide solution in which the aromatic carboxylic acid is dissolved, heating and stirring, and then adjusting the pH of the aqueous solution. Although it can synthesize | combine by adjusting and cooling to normal temperature and washing with filtered water, it is not limited only to said synthesis | combining method. Examples of the divalent metal include Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Pb ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Zn ²⁺ and Cu ²⁺ . Of these, Zn ²⁺ , Ca ²⁺ , Mg ²⁺ and Sr ²⁺ are preferable. Examples of the trivalent or higher metal include Al ³⁺ , Cr ³⁺ , Fe ³⁺ , Ni ³⁺ and Zr ⁴⁺ . Among these trivalent or higher metals, Al ³⁺ , Cr ³⁺ and Zr ⁴⁺ are preferable, and Al ³⁺ and Zr ⁴⁺ are particularly preferable. As the aromatic carboxylic acid derivative, a salicylic acid derivative is preferable. The charge control agent is preferably used in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the resin. If the content falls within this range, the charge level of the toner can be adjusted appropriately, making it easy to obtain the absolute charge required during development, and the carboxyl present in the binder resin during kneading, which is part of the toner manufacturing process. It is possible to moderately cause a metal cross-linking reaction between the group and the central metal of the metal compound of the aromatic carboxylic acid, to adjust the viscoelasticity of the toner, and to improve the heat melting property of the toner. Further, as described above, the charge control agent concentration on the toner particle surface is made higher than that in the toner, and a charge control agent having a higher charging property than the charge control agent existing in the toner is present on the toner particle surface. The absolute value of the peak top value of the main peak and the half width of the main peak in the q / d distribution described above are preferable because they are easy to control.

The toner of the present invention is preferably externally added with a fluidity improver (hereinafter referred to as external addition). Here, the fluidity improver has a function of increasing fluidity by being externally added to the toner particles, and is added from the viewpoint of improving the image quality. For example, fluorine resin powder such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; silica fine powder such as silica fine powder by wet process, silica fine powder by dry process, silica fine powder such as silane compound, titanium cup A treated silica fine powder subjected to a surface treatment with a treating agent such as a ring agent or silicone oil; a titanium oxide fine powder; an alumina fine powder, a treated titanium oxide fine powder, or a treated alumina oxide fine powder is used. Such a fluidity improver gives a good result when the specific surface area by nitrogen adsorption measured by the BET method is 30 m ² / g or more, preferably 50 m ² / g or more.

  The fluidity improver is used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the toner particles.

  The toner of the present invention preferably has a weight average particle diameter of 4 to 9 μm. By reducing the weight average particle size of the toner in this way, the reproducibility in developing the contour portion of an image, particularly a character image or a line pattern is improved. When the weight average particle diameter is less than 4 μm, for example, the adhesion force to the surface of the photosensitive drum is increased, which tends to cause uneven image unevenness due to transfer defects. Further, the charge amount per unit mass of the toner becomes high, and the image density may be lowered in a low temperature and low humidity environment, for example. Furthermore, due to a decrease in fluidity and an increase in adhesion to a member, for example, frictional charging with a carrier is difficult to be performed smoothly, toner that cannot be sufficiently charged increases, and fogging of non-image areas becomes conspicuous. . On the other hand, if the weight average particle size exceeds 9 μm, it means that there are few fine particles that can contribute to high image quality, and there is a merit that the fluidity of the toner is excellent, but on the fine electrostatic charge image on the photosensitive drum. It may be difficult to adhere faithfully, the reproducibility of the highlight portion may be lowered, and the gradation may be further lowered. In addition, fusion to a member such as the surface of the photosensitive drum is likely to occur. Furthermore, when 3 to 40% by number of toner having a particle diameter of 4 μm or less is contained and 10% by volume or less of toner having a particle diameter of 10 μm or more is contained, a toner having a balance between developability and transferability is obtained. It is easy to obtain and is particularly preferable.

  There are various methods for producing the toner of the present invention. For example, in the case of producing by a pulverization method, toner raw materials such as a binder resin, a wax, a colorant, and a charge control agent are mixed with a Henschel mixer or a ball mill. Mix thoroughly with a mixer, melt and knead using a thermal kneader such as a pressure kneader or extruder, and after cooling and solidification, the solid matter is collided with the target under a mechanical or jet stream to obtain the desired toner particle size. Finely pulverize. Then, the particle size distribution is sharpened through a classification process. Furthermore, the toner of the present invention can be obtained by sufficiently mixing the classified powder with an external additive using a mixer such as a Henschel mixer. Also, a method of directly producing toner particles by suspending a polymerizable monomer composition in water and polymerizing the composition, directly using a water-based organic solvent that is soluble in the monomer and insoluble in the obtained polymer. Conventionally known production methods such as a dispersion polymerization method for producing toner particles and a method for producing toner particles by aggregating and associating an emulsion produced by emulsion polymerization with a colorant can also be employed. However, as described above, the toner of the present invention has a very fine convex portion on the surface of the toner particle, and the entire surface of the toner particle has a special shape that does not have a smooth and acute protrusion. In any of the above manufacturing methods, for example, submicron-sized fine particles such as resin particles and inorganic particles are fixed and buried on the toner surface, and the surface is thinly coated with a resin. It is necessary to add some manufacturing process for making the toner particles have a special particle shape.

  The toner of the present invention can be used as a one-component developer or a two-component developer, but when used as a two-component developer, a clear full-color image can be easily obtained over a long period of time, which is preferable.

  When the toner of the present invention is used as a two-component developer, the toner of the present invention and a magnetic carrier may be mixed to form a two-component developer. Examples of the magnetic carrier include surface oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, calcium, magnesium, rare earth and other metals and their alloys or oxides and magnetic carriers such as magnetic ferrite. Can be used.

  In addition, a resin-coated carrier in which the surface of the magnetic carrier is coated with a resin or the like is preferably used in the present invention. As a method for producing a resin-coated carrier, a conventionally known method can be adopted and is not particularly limited. For example, a method of forming a coat film on a carrier surface by spraying a resin solution while floating and flowing a magnetic carrier , Spray drying, resin or other coating material dissolved or suspended in a solvent and mixed with a magnetic carrier, and the solvent is gradually volatilized while applying a shear stress, or a powder and magnetic carrier are simply mixed Is mentioned.

  Examples of the coating material for the magnetic carrier include resins having a low surface energy, such as a silicone resin and a fluorine resin, which are considered useful for preventing the toner carrier from being spent on the magnetic carrier, such as toner fusion. Styrenic resin, acrylic resin, polyamide, polyvinyl butyral, aminoacrylate resin, etc. are exemplified, and these are used alone or in combination.

  Moreover, in order to improve the adhesiveness with respect to a magnetic carrier, it is preferable to use various additives together and to improve the toughness of a film. In particular, when a silicone resin is coated, the durability and charging characteristics of the resulting coated carrier are further improved by adding water to the coating resin dilution solvent to be used. This is because the crosslinking point of the curable silicone resin and the hydrolysis of the silane coupling agent are promoted, the curing reaction proceeds further, and the surface energy of the silicone resin increases for a short period of time, so that it adheres to the magnetic carrier. This is due to the improvement in performance.

  The coating amount of the coating resin to the magnetic carrier is such that the resin solid content is 0.05 to 10 parts by mass, preferably 0.1 to 5 parts by mass per 100 parts by mass of the magnetic carrier.

  Moreover, it is preferable that the weight average particle diameter of a magnetic carrier is 25-80 micrometers, More preferably, it is 30-65 micrometers. The particle size can be measured by using an SRA type Microtrac particle size analyzer (manufactured by Nikkiso Co., Ltd.) and setting a range of 0.7 to 125 μm. When the weight average particle diameter of the magnetic carrier is smaller than 25 μm, mixing with the toner becomes difficult. On the other hand, when the weight average particle size exceeds 80 μm, the specific surface area of the magnetic carrier is small, so that the charging ability at the time of toner replenishment is inferior, which may cause fogging and toner scattering.

  When the two-component developer is prepared by mixing the toner of the present invention and the magnetic carrier of the above form, the mixing ratio is 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. In general, good results are obtained. If the toner concentration is less than 2% by mass, the image density tends to decrease. If the toner concentration exceeds 15% by mass, fogging or in-machine scattering tends to occur, and the useful life of the developer tends to decrease.

  Next, an example of an image forming method to which the toner of the present invention is applied will be described below with reference to the drawings showing an image forming apparatus to which the image forming method is applied.

  FIG. 4 shows an image forming apparatus for a two-component developer. Developers 1Y, 1M, 1C, and 1K are respectively introduced with a developer having yellow toner, a developer having magenta toner, a developer having cyan toner, and a developer having black toner. The electrostatic charge images formed on the drums 28Y, 28M, 28C, and 28K are developed, and the respective color toner images are formed on the photosensitive drums 28Y, 28M, 28C, and 28K. The toner image on the photosensitive drum 28 is transferred onto the intermediate transfer belt 24a, and the transfer residual toner on the photosensitive drum 28 is collected as waste toner by the cleaner 26. The toner image transferred onto the intermediate transfer belt 24a is transferred onto the transfer material 27 in a lump for each color by a transfer roller (secondary transfer charger).

  The toner of the present invention can be mixed with a magnetic carrier and developed using, for example, developing means as shown in FIG. Specifically, it is preferable to perform development in a state where the magnetic brush is in contact with the photosensitive drum 13 while applying an alternating electric field. The distance B between the developer carrying member (developing sleeve) 11 and the photosensitive drum 13 is 100 to 1000 μm.

  The voltage (Vpp) between the peaks of the alternating electric field is preferably 500 to 5000 V, the frequency (f) is 500 to 10000 Hz, and various waveforms such as a triangular wave, a rectangular wave, a sine wave, or a waveform with a changed duty ratio can be selected. Can be used. The contrast potential is preferably 200 V to 500 V so that a sufficient image density can be obtained.

  The contact width (development nip C) of the magnetic brush on the developing sleeve 11 with the photosensitive drum 13 is preferably 3 to 8 mm in order to achieve a sufficient image density, excellent dot reproducibility, and development without carrier adhesion. To.

  The toner of the present invention can be developed using a developing means for a non-magnetic one-component developer as shown in FIG. 6, for example, without being mixed with a magnetic carrier. FIG. 6 is a schematic view of an image forming apparatus for nonmagnetic one-component development. In FIG. 5, reference numeral 35 denotes a photosensitive drum, and latent image formation is formed by electrophotographic process means. A bias is applied between the developing sleeve 34 as a toner carrier and a photosensitive drum by a bias power source. The developing sleeve 34 is preferably a cylinder made of stainless steel, aluminum or the like, and the surface may be coated with a resin in which fine particles such as metals, carbon black, and charge control agent are dispersed, if necessary. The gap α between the photosensitive drum and the developing sleeve 34 is set to 50 to 500 μm in the case of jumping development. The developing nip width is preferably set to 0.2 to 8.0 mm. In the case of contact development, a so-called elastic roller having an elastic layer on the surface is preferably used as the developing sleeve, and the hardness of the material of the elastic layer used is 30 to 60 degrees (asker-C / load). 1 kg) is preferably used.

  The substantially right half circumferential surface of the developing sleeve 34 is always in contact with the toner reservoir in the toner container 31, and the toner near the developing sleeve surface is attached and held on the developing sleeve surface by electrostatic force.

  By setting the surface roughness Ra (μm) of the developing sleeve to 1.5 or less, the toner layer on the developing sleeve can be thinned. The surface movement speed of the developing sleeve is preferably set to be 1.05 to 3.0 times the surface movement speed of the photosensitive drum.

  The toner T is stored in the toner container 31 and is supplied onto the developing sleeve by the supply member 32. As the supply member, a supply roller made of a foamed material such as a porous elastic body, for example, a flexible polyurethane foam is preferably used. The supply roller is rotated at a relative speed in the forward or reverse direction with respect to the development sleeve, and the toner is supplied onto the development sleeve. Also, the developed toner (undeveloped toner) on the developing sleeve is peeled off.

  The toner supplied onto the developing sleeve is uniformly applied in a thin layer by the regulating member. The regulating member for thinning the toner is a doctor blade such as a metal blade or a magnetic blade disposed with a certain gap from the developing sleeve. Further, an elastic body such as an elastic blade or an elastic roller for press-fitting toner may be used as a toner thinning regulating member.

  For example, in FIG. 6, the elastic blade 33 has a base which is the upper side portion fixed to the toner container 31 side and a lower side portion which is bent in the forward or reverse direction of the developing sleeve 34 against the elasticity of the blade. In this state, the inner surface of the blade (the outer surface in the case of the reverse direction) is brought into contact with the surface of the developing sleeve 34 with an appropriate elastic pressure. According to such an apparatus, it is possible to obtain a dense toner layer that is stable against environmental changes. For the elastic blade, it is preferable to select a material of a triboelectric charge series suitable for charging the toner to a desired polarity, rubber elastic body such as silicone rubber, urethane rubber, NBR, etc .; synthetic resin elastic body such as polyethylene terephthalate A metal elastic body such as stainless steel, steel or phosphor bronze can be used. Moreover, those composites may be sufficient. Further, in the case where durability is required for the regulating member and the developing sleeve, it is preferable to use a metal elastic body bonded with resin or rubber so as to contact the sleeve contact portion or a coating applied as the regulating member. . An effective contact pressure between the elastic member and the developing sleeve is 0.1 to 30 kPa. The gap between the elastic blade and the developing sleeve is preferably set to 50 to 400 μm.

  Hereinafter, various physical property measuring methods used in the present invention will be described.

<Duel time and q / d distribution measurement>
The following operations are performed in a room controlled at 23 ° C. and 60% RH.

First, a magnetic ferrite carrier (Mn—Mg ferrite; average particle diameter of 50 μm) whose surface is coated with a toner and a silicone resin is left overnight in the above environment, and then the toner concentration is 6% by mass. The mixture is put in a 50 ml polybin and shaken for 180 seconds at 2.5 s ^-1 with a Yayoi-type shaker “YS-8D” (trade name, manufactured by Yayoi Co., Ltd.). adjust.

  And E-SPART Analyzer MODEL EST-III ver. Using 9.03 (trade name, manufactured by Hosokawa Micron Corporation), the toner's due time and q / d distribution are measured as follows.

The above-described developer is held in a two-component feeder (developer holding base having a rotating disk with a built-in magnet) attached to E-SPARA Analyzer. Next, nitrogen gas is sprayed from the air nozzle to the developer held magnetically in the two-component feeder to blow off only the toner, and only the toner is sucked into the E-SPART Analyzer measuring section through the sample introduction tube at the bottom of the two-component feeder. Then, the due time (ms), the particle diameter d (μm), and the charge amount q (femto-C) are measured for each particle. And based on this data, q / d distribution and duel time distribution are obtained. In addition, the measurement conditions of E-SPART Analyzer in this embodiment were as follows.
Measurement toner particle number: 3000 pieces PM VOLTAGE: -460V
FIELD VOLTAGE: 100V
Measuring unit suction flow rate: 6.6 × 10 ⁻⁶ m ³ / s
Two-component feeder rotational speed: 0.025 to 0.050 s ⁻¹
Rectifier DC voltage for electromagnetic coil: 90V
Nitrogen gas blow pressure: 20 kPa
Nitrogen gas blow time: 1 second Nitrogen gas blow interval: 4 seconds

<Measurement of Toner Average Circularity, Circularity Standard Deviation, and Mode Circularity>
The average circularity, circularity standard deviation, and mode circularity of the toner are measured using a flow type particle image measuring device “FPIA-2100” (trade name, manufactured by Sysmex Corporation), and calculated using the following formula. .

  Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define. The measurement uses the perimeter of the particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm).

  In the present invention, the circularity is an index indicating the degree of unevenness of the toner particles, and is 1.000 when the toner particles are completely spherical. The more complicated the surface shape, the smaller the circularity.

  The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where ci is the circularity (center value) at the dividing point i of the particle size distribution and m is the number of measured particles.

  The circularity standard deviation SD is calculated from the following equation where the average circularity C, the circularity ci of each particle, and the number of measured particles are m.

  Mode circularity means that the circularity is from 0.40 to 1.00, from 0.400 to less than 0.410, from 0.410 to less than 0.420, ... 0.990 to 1.000 The circularity of the peak at which the frequency value is maximized in the circularity frequency distribution is obtained by dividing the measured circularity of each particle by 61 and dividing the measured circularity by 61.

  In addition, “FPIA-2100” which is a measuring apparatus used in the present invention calculates the circularity of each particle, and then calculates the average circularity, the circularity standard deviation, and the mode circularity. The particles are divided into classes in which the circularity of 0.4 to 1.0 is equally divided every 0.01, and the average circularity, circularity standard deviation, and mode circularity are calculated using the center value of the dividing point and the number of measured particles. Calculate the degree.

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Preferably, autofocus is performed using 2 μm latex particles every 2 hours.

  To measure the circularity of the toner particles, the flow type particle image measuring device is used, and the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl. Measure more than one. After the measurement, data having an equivalent circle diameter of less than 3 μm is cut using this data, and the average circularity of the toner particles is obtained.

  Furthermore, “FPIA-2100”, which is a measuring apparatus used in the present invention, improves the magnification of the processed particle image, compared with “FPIA-1000” that has been used to calculate the shape of the toner. The accuracy of toner shape measurement has been improved by improving the processing resolution of the captured image (256 × 256 → 512 × 512), thereby achieving more reliable capture of fine particles. Therefore, when it is necessary to measure the shape more accurately as in the present invention, the FPIA-2100 that can obtain information on the shape more accurately is more useful.

<Measurement of weight average particle size and particle size distribution of toner>
The weight average particle size and particle size distribution of the toner can be measured by various methods such as Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, a Coulter Multisizer is used to connect a number distribution and volume distribution interface (manufactured by Nikka Kisha Co., Ltd.) and a personal computer, and the electrolyte is a 1% NaCl aqueous solution using first grade sodium chloride. Prepare. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, a surfactant, preferably alkylbenzene sulfonate 0.1 to 0.3 cm ³ is added as a dispersant to 100 to 150 cm ^{3 of the} electrolytic aqueous solution, 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 using an ultrasonic disperser, and the volume distribution is determined by measuring the volume and number of toner particles of 2 μm or more using the 100 μm aperture as the aperture by the Coulter Multisizer. And the number distribution. Then, the weight average particle diameter (D4: the median value of each channel is the representative value of the channel) obtained from the volume distribution according to the present invention can be obtained.

<Differential thermal analysis measurement>
It measures according to ASTM D3418-82 using a differential scanning calorimeter (DSC measuring device) and DSC2920 (manufactured by TA Instruments Japan). The measurement sample is precisely weighed in an amount of 2 to 10 mg, preferably 5 mg. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rising rate of 10 ° C./min within a measurement temperature range of 30 to 200 ° C. In the measurement, the temperature is increased and then the temperature is decreased once, and then the temperature is increased again. The maximum endothermic peak of the DSC curve in the temperature range of 30 to 200 ° C. It is set as the endothermic peak in the invention.

<Measurement of molecular weight distribution>
The measurement of the molecular weight distribution of the resin component by gel permeation chromatography (GPC) may be performed as follows.

A solution obtained by allowing a binder resin or toner to stand still in tetrahydrofuran (THF) at room temperature for 24 hours is dissolved in a solvent-resistant membrane filter having a pore diameter of 0.45 μm (for example, trade name “Maeshori Disc” manufactured by Tosoh Corporation). The sample solution is filtered through and measured under the following conditions. In addition, sample preparation adjusts the quantity of THF so that the density | concentration of the component soluble in THF may be 0.4-0.6 mass%.
Apparatus: High-speed GPC HLC8120 GPC (manufactured by Tosoh Corporation)
Column: Shodex KF-801, 802, 803, 804, 805,
7 series of 806, 807 (made by Showa Denko)
Eluent: Tetrahydrofuran Flow rate: 1.0 cm ³ / min
Oven temperature: 40.0 ° C
Sample injection amount: 0.10 cm ³

  In calculating the molecular weight of the sample, standard polystyrene resin (TSO standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- manufactured by Tosoh Corporation) was used. 10, F-4, F-2, F-1, A-5000, A-5.000, A-1000, A-500).

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

<Example of production of polyester resin A>
In a reaction vessel equipped with a thermometer, a stirrer, a condenser and a nitrogen introduction tube, 48.1 parts by mass (35.0 mol%) of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane ), 19.2 parts by mass (15.0 mol%) of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 20.4 parts by mass of terephthalic acid (31.3 mol%) , 9.4 parts by mass (12.4 mol%) of trimellitic anhydride, 2.9 parts by mass of fumaric acid (6.3 mol%) and 0.30 parts by mass of dibutyltin oxide were added. Then, the temperature was gradually raised while stirring, and a condensation reaction was carried out at 215 ° C. for 4 hours to obtain a polyester resin A.

<Toner Production Example 1>
-100 mass parts of said polyester resin A-C.I. I. Pigment Blue 15: 3 5 parts by mass, 3,5-di-t-butylsalicylic acid aluminum compound 3 parts by mass, maximum endothermic peak in DSC, carnauba wax having a peak temperature of 82 ° C. 3 parts by mass Sufficiently premixed by Mitsui Mining Co., Ltd.). Thereafter, melt kneading was repeated with a twin screw extrusion kneader, and after cooling, coarsely pulverized to about 1 to 2 mm using a hammer mill. Subsequently, it was finely pulverized to a particle size of 20 μm or less with an air jet fine pulverizer. Thereafter, the finely pulverized product was treated for 3 minutes at a rotational speed of 100 s ⁻¹ with a surface modification (spheronization) treatment device “Hybridizer” (manufactured by Nara Machinery Co., Ltd.) using mechanical impact force, and then Using a wind classifier (elbow jet classifier), the particles were classified so that the weight average particle diameter was about 7 μm to obtain particles 1A.

Further, 100 parts by mass of this particle 1A and 1.0 part by mass of polymethyl methacrylate resin particles having a weight average particle diameter of 0.5 μm were subjected to a blade rotation speed of 90 s ⁻ by a Q mixer (made by Mitsui Mining Co., Ltd.) having an impact blade. Mix at ^{1 for} 10 minutes. Next, 2.5 parts by mass of hydrophilic silica particles (specific surface area of 200 m ^{2 /} g by BET method) were added and further mixed for 5 minutes to obtain particles 1B.

100 parts by mass of the obtained particle 1B was put into 400 parts by mass of water, and stirred at 200 s ⁻¹ with a high-speed stirring device TK type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, a solution prepared by dissolving 1 part by mass of the polyester resin A and 0.2 parts by mass of a 3,5-di-t-butylsalicylic acid zirconium compound in 20 parts by mass of ethyl acetate was added dropwise thereto while stirring was continued. And after raising the water temperature to 73 degreeC and ageing | curing | ripening for 2 hours, ethyl acetate was distilled off under reduced pressure and it cooled. Thereafter, sodium hydroxide was added to water to dissolve the hydrophilic silica, and the particles were filtered and washed with water. Thereafter, it was dried with hot air at 40 ° C. for 3 days to obtain particles 1C.

100 parts by weight of the obtained particles 1C and 10 parts by weight of hexamethyldisilazane, and then 10 parts by weight of hydrophobic silica fine powder treated with silicone oil (specific surface area 120 m ^{2 /} g by BET method) 1.4 parts by weight And 1.5 parts by mass of hydrophobic titanium oxide (specific surface area 130 m ^{2 /} g by BET method) treated with 20 parts by mass of i-C ₄ H ₉ Si (OCH ₃ ) ₃ , Toner 1 of the present invention was obtained.

  Using the above-described particle charge amount distribution measuring apparatus by the laser Doppler method, the particle diameter d (μm), the charge amount q (femto-C), and the dwell time (ms) of 13,000 toners of the present invention are as described above. Measured and processed data. The prepared q / d distribution chart is shown in FIG. 2, and the due time distribution chart is shown in FIG. 3. From these figures, the toner 1 of the present invention has particles having a due time range of 3.0 to 10.0 ms. Is 61% by number based on all toner particles, the peak top value of the main peak in the q / d distribution is 0.40 (femto-C / μm), and the half width of the main peak is 0.18 (femto-C). / Μm).

<Toner Production Example 2>
Toner 2 of the present invention was obtained in the same manner as in Toner Production Example 1 except that the finely pulverized product was classified by an air classifier so that the weight average particle diameter was about 5 μm.

<Toner Production Example 3>
Toner 3 of the present invention was obtained in the same manner as in Toner Production Example 1 except that the finely pulverized product was classified using an air classifier so that the weight average particle size was about 9 μm.

<Toner Production Example 4>
Except for changing the addition amount of the zirconium 3,5-di-t-butylsalicylate compound dissolved in ethyl acetate from 0.2 parts by mass to 0.5 parts by mass, the same procedure as in Toner Production Example 1 was performed. Toner 4 was obtained.

<Toner Production Example 5>
Except for changing the addition amount of the zirconium 3,5-di-t-butylsalicylate compound dissolved in ethyl acetate from 0.2 parts by mass to 0.05 parts by mass, the same procedure as in Toner Production Example 1 was performed. Toner 5 was obtained.

<Toner Production Example 6>
Toner production example 1 except that the processing conditions in the hybridizer were changed to a rotation speed of 110 s ⁻¹ and a processing time of 10 minutes, and the processing conditions of the Q mixer were changed to 115 s ⁻¹ and the processing time of 20 minutes. In the same manner as in Example 1, a toner 6 of the present invention was obtained.

<Toner Production Example 7>
Toner production example 1 except that the processing conditions in the hybridizer were changed to a rotational speed of 60 s ⁻¹ and a processing time of 1 minute, and the processing conditions of the Q mixer were changed to 50 s ⁻¹ and a processing time of 10 minutes. In the same manner as in Example 1, a toner 7 of the present invention was obtained.

<Toner Production Example 8>
In Toner Production Example 1, Toner 8 of the present invention was obtained in the same manner as in Toner Production Example 1 except that the spheroidizing treatment by the hybridizer was not performed.

<Toner Production Example 9>
-100 mass parts of said polyester resin A-C.I. I. Pigment Blue 15: 3 5 parts by mass, 3,5-di-t-butylsalicylic acid aluminum compound 3 parts by mass, maximum endothermic peak in DSC, peak temperature 82 ° C. carnauba wax 3 parts by mass Premixed with a mixer. Thereafter, the mixture was melt-kneaded with a twin-screw extrusion kneader, and after cooling, coarsely pulverized to about 1 to 2 mm using a hammer mill. Subsequently, it was finely pulverized to a particle size of 20 μm or less with an air jet fine pulverizer. Thereafter, the finely pulverized product was classified by an air classifier so that the weight average particle diameter was about 7 μm, and thereby particles 9A were obtained.

Further, 100 parts by mass of the particles 9A and 10 parts by mass of hexamethyldisilazane, and then 10 parts by mass of hydrophobic silica fine powder treated with silicone oil (specific surface area 120 m ^{2 /} g by BET method) 1.4 parts by mass And 1.5 parts by mass of hydrophobic titanium oxide (specific surface area 130 m ^{2 /} g by BET method) treated with 20 parts by mass of i-C ₄ H ₉ Si (OCH ₃ ) ₃ , A comparative toner 9 was obtained.

<Toner Production Example 10>
The particles 9A produced in Toner Production Example 9 were treated with a hybridizer at a rotation speed of 100 s ^-1 for 3 minutes to obtain particles 10A. 100 parts by mass of the particles 10C, 1.4 parts by mass of hydrophobic silica fine powder (specific surface area 120 m ^{2 /} g by BET method) treated with 10 parts by mass of silicone oil after 10 parts by mass of hexamethyldisilazane, And 1.5 parts by mass of hydrophobic titanium oxide (specific surface area 130 m ^{2 /} g by BET method) treated with 20 parts by mass of i-C ₄ H ₉ Si (OCH ₃ ) ₃ for comparison with a Henschel mixer Toner 10 was obtained.

  Table 1 shows the physical properties of the toners 1 to 8 of the present invention and the comparative toners 9 and 10 produced as described above.

Ａ ：デュエルタイムが３．０〜１０．０ｍｓのトナーの割合（個数％）
Ｂ ：トナーの帯電量ｑ（ｆｅｍｔｏ−Ｃ）とトナー粒径ｄ（μｍ）から表されるｑ／ｄ
分布におけるメインピークのピークトップの値の絶対値（ｆｅｍｔｏ−Ｃ／μｍ）
Ｃ ：ｑ／ｄ分布におけるメインピークの半値幅（ｆｅｍｔｏ−Ｃ／μｍ）
Ｄ ：円相当径３μｍ以上の粒子の平均円形度
Ｅ ：円形度標準偏差
Ｆ ：モード円形度

A: Proportion (number%) of toner having a duel time of 3.0 to 10.0 ms
B: q / d represented by toner charge amount q (femto-C) and toner particle diameter d (μm)
Absolute value of peak top value of main peak in distribution (femto-C / μm)
C: full width at half maximum (femto-C / μm) of main peak in q / d distribution
D: Average circularity of particles having an equivalent circle diameter of 3 μm or more E: Circularity standard deviation F: Mode circularity

<Preparation of two-component developer>
Magnetic ferrite carrier particles whose surface is coated with a silicone resin for each of the toners 1 to 8 of the present invention produced in toner production examples 1 to 8 and the comparative toners 9 to 10 produced in toner production examples 9 to 10 ( Mn—Mg ferrite; average particle size 50 μm) and a toner concentration of 6% by mass are mixed into a plastic bottle and shaken with a Yayoi shaker at 2.5 s ⁻¹ for 180 seconds. The two-component developers 1 to 8 of the present invention and the comparative two-component developers 9 to 10 were produced.

[Examples 1-8, Comparative Examples 1-2]
The image forming apparatus used in this embodiment will be described. FIG. 4 is a schematic diagram of an image forming apparatus applied to this embodiment, and FIG. 5 is a schematic diagram of a developing unit of the image forming apparatus.

  As the photosensitive drum 28, one having a characteristic having an effective sensitivity region with respect to a short wavelength laser beam of 350 to 500 nm is used, and a photosensitive layer having an organic photo semiconductor is provided on a base material. After the photosensitive drum 28 is uniformly charged by the charger 21, an electrostatic latent image having a resolution of 2400 dpi is formed on the photosensitive drum by the exposure unit 22. The exposure means 22 uses a blue light semiconductor laser light-emitting element having a main oscillation wavelength of 400 to 450 nm, collimates the emitted light beam with a collimator lens, and condenses it on a polygon mirror, which is a rotating reflector, with a cylindrical lens. Then, the light is reflected and deflected and condensed and scanned to a spot diameter of 10.6 μm on the photosensitive drum by the fθ lens group, and this is turned on and off according to digital image information.

Next, the developing device 1 is used to develop the toner on the photosensitive drum 28 by reversal development. The photosensitive drum 28 used here has a diameter of 20 mmΦ, and is driven to rotate at a speed of 2.6 s ⁻¹ during development. The toner image on the photosensitive drum 28 is transferred onto the intermediate transfer belt 24a, and the transfer residual toner on the photosensitive drum 28 is collected as waste toner by the cleaner 26.

  The toner image transferred onto the intermediate transfer belt 24a is transferred onto the transfer material 27 in a lump for each color by a transfer roller (secondary transfer charger). The intermediate transfer belt 24a is formed by molding a composition made of polybutylene terephthalate resin, polycarbonate resin, carbon black, and lithium perchlorate to a thickness of 120 μm.

  As the heat fixing device 25, a heat roll type fixing device having no application function of the liquid for preventing offset was used. At this time, both an upper roller and a lower roller having a fluororesin surface layer were used, and the diameter of the roller was 55 mm. The fixing temperature was set to 175 ° C., and the nip width was set to 8 mm.

Each of the developers 1 to 8 and the developers 9 to 10 for comparison were filled in a developing device and left overnight at room temperature and normal humidity (23 ° C., 50% RH). Thereafter, while replenishing the toner sequentially so that the toner density becomes constant, using plain paper for copying machines (80 g / m ² ) as a transfer material and sampling an evaluation image, which will be described later, an image area ratio of 5% 5000 images were output at a single color mode, 24 sheets (A4 size) / minute (process speed 165 mm / s). Next, the image forming apparatus is moved together with the developing device to a low temperature and low humidity (15 ° C., 10% RH) environment and left for one week, and an image 3000 having an image area ratio of 3% is sampled while sampling an evaluation image to be described later. Output. Furthermore, it moved to a high-temperature and high-humidity (30 ° C., 80% RH) environment together with the image forming apparatus and left to stand for one week, and 1000 images with an image area ratio of 10% were output while sampling an evaluation image described later. .

  Next, each evaluation item will be described.

(1) Dot reproducibility An image of an isolated dot pattern with a small diameter (45 μm) as shown in FIG. 7 is easily output due to the latent image electric field, which is difficult to reproduce. Was observed with a microscope, and dot reproducibility was evaluated as follows.
A: 2 or less defects / 100 B: 3-5 defects / 100 defects C: 6-10 defects / 100 defects D: 11 defects / 100 defects / 100

(2) Durability and stability On the 10th and 900th sheets in a high-temperature and high-humidity environment, an 80 μm × 50 μm checkered pattern image shown in FIG. 8 is output, and the number of defects in 100 solid portions by a microscope The increase in the number of defects from the 10th sheet to the 900th sheet was evaluated as follows as an index of the durability stability of the toner.
A: 0-2 increase in defect number B: 3-5 increase in defect number C: 6-10 increase in defect number D: 11 or more increase in defect number

(3) Fine line reproducibility Striped thin line images as shown in FIG. 9 were output on the 2500th sheet in a low temperature and low humidity environment and on the 800th sheet in a high temperature and high humidity environment. (FIG. 9 is a latent image with a latent image portion width of 8 dots (80 μm) and a non-latent image portion width of 20 dots (200 μm) at a resolution of 2400 dpi.)

Then, five locations were selected at random from each image, and evaluated by the absolute value of the difference between the average value of the fine line width of the image and the theoretical latent image portion width (80 μm).
A: 0 μm or more, less than 7 μm B: 7 μm or more, less than 15 μm C: 15 μm or more, less than 20 μm D: 20 μm or more

(4) Image density A solid image was output on the 4500th sheet in a room temperature and humidity environment, and the image density was measured. The image density was measured with an X-Rite color reflection densitometer (Color reflection densitometer X-Rite 404A).
A: Very good (over 1.60)
B: Good (from 1.40 to less than 1.60)
C: Normal (1.20 or more, less than 1.40)
D: Bad (less than 1.20)

(5) Fog After the image output in a high-temperature and high-humidity environment is completed, a solid white image is output, the image forming apparatus is forcibly stopped during solid white image formation, and a solid white image portion on the photosensitive drum. Were taped with a transparent polyester adhesive tape and attached to white paper. Only the unused tape was stuck on the same white paper, and the whiteness of each was measured, and the fog was calculated from the difference in whiteness. The whiteness was measured by a reflectometer equipped with an amber filter ("REFLECTOMETER MODEL TC-6DS" manufactured by Tokyo Denshoku).
A: Very good (less than 2.0%)
B: Good (2.0% or more, less than 3.0%)
C: Normal (3.0% or more and less than 5.0%)
D: Poor (5.0% or more)

(6) Transferability A solid image is output on the 2900th sheet in a low-temperature and low-humidity environment and on the 950th sheet in a high-temperature and high-humidity environment. The difference in concentration was calculated by subtracting the concentration of the adhesive tape only on the paper from the concentration of the adhesive tape taped and peeled off with the adhesive tape. And it judged as follows from the value of the density difference. The density was measured with the X-Rite color reflection densitometer described above.
A: Very good (less than 0.05)
B: Good (less than 0.05 to 0.1)
C: Normal (less than 0.1-0.2)
D: Bad (over 0.2)

  The respective evaluation results are shown in Table 2.

It is explanatory drawing showing the calculation method of the peak top value of a main peak in a q / d distribution, and the half value width of a main peak. FIG. 6 is a q / d distribution diagram of the toner “Toner 1” of the present invention. FIG. 6 is a distribution diagram of due time of the toner “toner 1” of the present invention. 1 is a schematic explanatory diagram of an image forming apparatus for a two-component developer used in an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a main part of a developing device for a two-component developer used in an example of the present invention. It is a schematic explanatory drawing of the image forming apparatus for nonmagnetic one-component development. It is a schematic diagram which shows the isolated dot image for evaluating the dot reproducibility of the Example of this invention. It is a schematic diagram which shows the checker image for evaluating the durability stability of the Example of this invention. It is a schematic diagram which shows the fine line image for evaluating the fine line reproducibility of the Example of this invention.

Explanation of symbols

1Y, M, C, K: Developing devices 21Y, M, C, K: Chargers 22Y, M, C, K: Exposure means 28Y, M, C, K: Photosensitive drums 23Y, M, C, K: Transfer Blade (primary transfer charger)
23a: Transfer roller (secondary transfer charger)
26Y, M, C, K: cleaner 24a: intermediate transfer belt 25: fixing device (fixing roller)
27: transfer material 12: developer carrier 13: photosensitive drum 14: magnet 15: screw 16: developer transport roller 17: developer 18: magnetic blade 31: toner container 32: supply member 33: elastic blade 34: development Sleeve 35: Photosensitive drum T: Toner

Claims (3)

  A toner containing at least a binder resin, a colorant, and a wax, and when the 3000 toners are measured with a particle charge amount distribution measuring apparatus by a laser Doppler method, the due time is in the range of 3.0 to 10.0 ms. A certain particle is in the range of 40 to 90% by number based on the total toner particles, and the peak of the main peak in the q / d distribution represented by the toner charge amount q (femto-C) and the toner particle diameter d (μm). The absolute value of the top value is in the range of 0.20 to 0.80 (femto-C / μm), and the half width of the main peak in the q / d distribution is 0.10 to 0.40 (femto-C / μm). A toner characterized by being in the range of   When the toner is measured with a flow type particle image measuring device, the average circularity of particles having an equivalent circle diameter of 3 μm or more is 0.920 to 0.990, and the circularity standard deviation is 0.010 to 0.050. The toner according to claim 1, wherein the mode circularity is 0.92 to 0.99. An electrostatic process is carried out by charging the electrostatic charge image carrier and irradiation with a semiconductor laser having a wavelength range of 350 to 500 nm on the electrostatic charge image carrier that is driven to rotate at a rotation speed of 2.0 s ^-1 or more. An exposure step for forming a latent image, a development step for transferring toner from the developer carrier to the electrostatic latent image and developing, and a toner image developed on the electrostatic latent image transferred via an intermediate transfer member A full-color image forming method having at least a transfer step of transferring to a material and a fixing step of heat-fixing the toner on the transfer material, wherein the toner contains at least a binder resin, a colorant and a wax, When 3,000 toners are measured with a particle charge amount distribution measuring apparatus by the laser Doppler method, particles whose due time is in the range of 3.0 to 10.0 ms are 40 based on the total toner particles. The absolute value of the peak top value of the main peak in the q / d distribution represented by the toner charge amount q (femto-C) and the toner particle size d (μm) is in the range of 90% by number. An image having a range of 0.80 (femto-C / μm) and a half-value width of a main peak in a q / d distribution in a range of 0.10 to 0.40 (femto-C / μm). Forming method.

Images