JP2002287400A - Dry toner, manufacturing method for the toner and image forming apparatus using the toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner with which images of high resolution and high image quality can be stably formed many times without causing any cleaning failure by toner shape control. SOLUTION: The dry toner containing at least resin and colorant, has a roundness of 0.960 to 1.000 and has a plurality of recesses on its surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and an electrophotographic developing apparatus using the toner. About. More specifically, the present invention relates to a toner for electrophotography, a developer for electrophotography, and an electrophotographic developing device used for a copier, a laser printer, a plain paper fax, and the like using a direct or indirect electrophotographic development system. Further, the present invention relates to a full-color copying machine, a full-color laser printer, a full-color plain paper facsimile, and other electro-photographic toners, electro-photographic developers, and electro-photographic developing devices using a direct or indirect electro-photographic multi-color developing system.

The present invention also relates to primary transfer in which a toner image is transferred from an image carrier to an intermediate transfer member through an intermediate transfer member such as an intermediate transfer belt, and a primary transfer image on the intermediate transfer member is transferred to a transfer material. The present invention relates to a toner used in a full-color electrophotographic image forming method in which an image is formed through each transfer step of a secondary transfer for transferring, a method of manufacturing the same, and an image forming apparatus.

[0003]

2. Description of the Related Art In an image forming apparatus using an electrophotographic method or an electrostatic recording method, a method of visualizing image information via an electrostatic latent image is currently used in various fields. For example, in electrophotography, an electrostatic latent image is formed on a photoconductor by an exposure process following a charging process, the electrostatic latent image is visualized with a developer, and image information is reproduced through a transfer and fixing process. . The developer includes a one-component developer using a magnetic toner or a non-magnetic toner alone, and a two-component developer including a toner and a carrier. Toner is usually a thermoplastic resin pigment,
It is manufactured by a kneading and pulverizing method in which the mixture is melt-kneaded with a releasing agent such as a wax or a charge controlling agent as required, then finely pulverized, and further classified. If necessary, inorganic or organic fine particles may be added to the surface of the toner particles in order to improve fluidity and cleaning properties. In the ordinary kneading and pulverizing method, the shape and surface structure of the toner are indefinite, and vary slightly depending on the pulverizability of the material to be used and the conditions of the pulverizing process. However, it is not easy to arbitrarily control the toner shape and the surface structure. Further, further narrowing the particle size distribution of the toner leads to a limit of the classifying ability and an increase in cost, so that it is in a situation where further improvement is difficult. Further, when considering the average particle size in the toner particle size distribution from the viewpoint of yield, productivity and cost, it is a very serious problem for the pulverized toner to make the average particle size small, especially 6 μm or less.

[0004] Next, the chargeability of the irregular-shaped toner produced by pulverization is different because the area of adhesion to a developing roll in a one-component developer and the area of adhesion to a carrier in a two-component developer differ for each toner particle. The adhesive force to the developing roll or carrier is different, and the easiness of development is also different. Since toners having different particle diameters have different amounts of electric charge of one toner particle, the ease of development is also different. Due to these differences, the easily developable toner is selectively developed and the hardly developable toner remains in the developing device, so that the developability changes over time. Also,
Also in the transfer to the recording paper, similarly, since there is a toner which is easily transferred and a toner which is hardly transferred, image quality deterioration such as toner scattering is likely to occur. Further, when a toner is manufactured by internally adding a release agent such as a wax, the release agent may be exposed on the surface of the toner in combination with a thermoplastic resin. In particular, in the case of a combination of a resin which is imparted with elasticity by a high molecular weight component and is hardly pulverized and a brittle wax such as polypropylene, the wax is often exposed on the toner surface. Exposure of the release agent is advantageous for the releasability at the time of fixing and cleaning of the toner remaining on the photoreceptor after transfer.However, since the fluidizing agent on the toner surface is easily moved by mechanical force, the development roll, Wax contamination of the photoreceptor and carrier is likely to occur, leading to a decrease in reliability of the image forming apparatus.

On the other hand, in order to overcome the problems of the toner by the pulverization method, a method of producing the toner by a suspension polymerization method has been proposed. Since this method does not include a pulverizing step, the toner step does not require a kneading step and a pulverizing step, which greatly contributes to cost savings such as energy saving, reduction of production time, improvement of process yield, and toner particles. The particle size distribution in is also easier to sharp distribution than the pulverization method, and
The advantage of improving the fluidity by encapsulating the wax is also expanded. The polymerization method having many advantages as described above is a method which is expected to be further studied by improving the binder and the method. However, there are still many problems that have not been solved by the toner method using the suspension polymerization method.

[0006] Since the toner obtained by the polymerization method is affected by the surface tension in the polymerization process, the sphericity of the particles is higher than that of the kneading and pulverization method, and the toner is advantageous in terms of charge stability and transferability. In such a case, it is difficult to scrape off the toner remaining on the image carrier with a blade, which causes a cleaning failure and a system problem in which the development density cannot be controlled due to the influence of the toner remaining on the photosensitive member after the transfer process. . For example, in Japanese Patent Application Laid-Open No. 11-149177, the shape factor SF-1 is 110
It is described that in the following case, cleaning of the transfer residual toner remaining on the latent image carrier becomes difficult, and cleaning failure easily occurs. JP-A-8-44111 and JP-A-8-286416 propose a suspension polymerization method. In the case of the suspension polymerization method, the particles need to be adjusted to an appropriate size in a suspended state. For this purpose, the desired quality cannot be produced unless the dispersion is stirred at high speed and at high speed to finely disperse the toner material. However, since the viscosity difference between the release material and the monomer is large and there is no compatibility, it is extremely difficult to finely disperse at this stage. As a result, many particles in which the wax does not exist in the resin are generated, causing uneven distribution among the toner particles, and causing a problem of unstable toner charging.

For example, in Japanese Patent Application Laid-Open No. 5-34979, in a two-component developing apparatus provided with development, transfer, and cleaning, an image is obtained by developing with a developer via a developing carrier, and transferring it to a transfer material to obtain an image. The method is characterized in that a developer containing a toner particle having an irregular shape is used. The toner having an uneven shape described in this publication is a toner having a convex portion on a projected image, and in a two-component developer using a carrier, the toner convex portion changes its shape due to stress caused by stirring. In some cases, this may lead to a decrease in cleaning performance. In addition, since the polymerization method is suspension polymerization, residual components of styrene monomer and acrylic monomer are contained, which is left as an environmental problem. In addition, since the wax is included, the fluidity and adhesion to the photoreceptor are reduced, but the fixing property of the toner is reduced compared to the pulverization method in which the wax as the release agent is present at the particle interface. As a result, the toner has a layer structure that does not easily seep out and has poor fixing efficiency. Further, the amount of WAX is increased in order to improve the fixing property, and the transparency of the color toner is further deteriorated by increasing the dispersed particle diameter of WAX.

The polymerization toner method includes, in addition to suspension polymerization, an emulsion polymerization method and a dissolution suspension method, which can relatively form an irregular form.
Even in the emulsion polymerization method, it is difficult to completely remove the styrene monomer and the emulsifier and the dispersant, and these days, the problem has become more and more serious especially when environmental problems are brought up. In addition, the unevenness of the shape makes it difficult for silica added as a fluidizing agent to adhere to the concave portions at the concave portions, and the silica moves to the concave portions during use to cause desorption of silica during long-term use of the developer. The problem of contamination and the problem of adhesion to the fixing roller are likely to occur.
In addition, the melt suspension method has the advantage of using a polyester resin that can be fixed at a low temperature. Since the high molecular weight component is added in the step of dissolving or dispersing the compound in a solvent, the viscosity of the solution is increased and a problem in productivity is likely to occur. They have not been eliminated yet. In particular, in the dissolution suspension method, JP-A-9-15
In Japanese Patent Publication No. 903, the cleaning is improved by forming the toner surface shape into a spherical toner and an irregular shape. However, since the toner is an irregular-shaped toner having no regularity, the toner is subjected to charging stability, and further has a basic durability quality and A high molecular weight design for ensuring releasability has not been made, and satisfactory quality has not been obtained. Japanese Patent Application Laid-Open No. 11-149180 discloses an attempt to prepare toner particles by reacting with an amine in an aqueous medium in a dry toner obtained by subjecting an isocyanate group-containing prepolymer to an elongation reaction and a crosslinking reaction. Although it can be manufactured, conditions for controlling the sphericity are not included, so it is difficult to control the target shape.

In general, an image forming method using an electrophotographic process includes development, transfer, cleaning, and fixing steps. In particular, in the case of polymerized toner, a plurality of steps are formed on a photoconductor as an electrostatic latent image carrier. The primary transfer is performed by sequentially superimposing the color toner images on the intermediate transfer body, and the color image composed of the toner images of a plurality of colors formed on the intermediate transfer body or the single color image is collectively and secondarily transferred to the transfer material. A color image forming apparatus for obtaining a color image or a monochromatic image is known, but after secondary transfer from the intermediate transfer body to a transfer material such as paper, transfer residual toner is present on the intermediate transfer body, and this toner Removal and treatment methods are one of the issues. Spherical toners produced by polymerization and other methods have shapes that are advantageous for transfer, but improved because they are shapes that are problematic for cleaning. But desired.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art. That is, the objects of the present invention are: Provided is a toner and a toner manufacturing method capable of stably forming a high-resolution and high-quality image many times without causing cleaning defects by controlling the toner shape.

2. The present invention provides a novel toner and a method for producing the toner, which have low power consumption and high transferability and OHP transparency required for a color image, at a high level. 3. Provided is a dry toner in which low molecular components remaining in the toner are reduced in consideration of environmental problems, and a manufacturing method. 4. Provided are a toner and an image forming apparatus which are excellent in transfer efficiency and can obtain high-quality images with little transfer residual toner.

[0012]

The present invention relates to a dry toner containing at least a resin and a colorant, wherein the toner has a circularity of 0.960 to 1.000, and has a plurality of dents on the surface. It is characterized by having spherical particles. The circularity is preferably 0.980 to 1.000.
By doing so, the sphericity is increased and the transferability during transfer is improved.

When the plurality of depressions on the toner surface are measured by a scanning electron microscope (SEM image), the long diameter of the depression is not more than 1/2 of the toner particle diameter, and the long diameter of the depression on the particle surface is 1.0. 0 to 5.0 μm, preferably 90% or more of the depressions with a major axis of 1.0 μm or more and an upper limit of not more than 5.0 μm, and spherical cleaning due to a plurality of depressions on the surface. In addition, the transferability is improved and the charging stability is improved in comparison with the irregular toner. In general, fine particles formed by pulverized toner or emulsion polymerization are problematic in that silica added to improve fluidity tends to accumulate in recesses, or when additives are mixed by stirring with a high-speed mixer, silica is immobilized. On the other hand, there is a concern that the silica particles are difficult to fix and the silica fine particles are liberated, causing contamination of the photoreceptor and adhesion to the carrier. It is presumed that the accumulation and migration of the additive silica, which was likely to occur, and the liberation during the immobilization of the silica did not occur. 3 is an electron micrograph of the toner according to FIG. 2. FIG. 3 is a photograph of a particle-assembled electron microscope having depressions.

The dry toner according to the present invention achieves high-resolution and high-quality images without poor cleaning while achieving low-temperature fixability that cannot be achieved with conventional pulverized toners or spherical polymerized toners that have attracted attention recently. The present inventors have found a feature that can be formed stably many times. The inventor of the present invention uses a polyester resin, which is a color toner or a polyester resin capable of designing a wide range of molecular weights with affinity to paper for energy saving, and the toner particle size and shape produced by the toner is such as fixability, hot offset and durability. The present invention has been accomplished by satisfying the basic requirements of (1) and achieving the object of cleaning, high resolution and high image quality.

That is, in the toner of the present invention, when a toner composition containing at least a polyester resin and a colorant or oil-less fixing is enabled, a composition containing a wax is dissolved / dispersed in an organic solvent, and the composition is dissolved. Is granulated in an aqueous medium and subjected to a polyaddition reaction under granulation. When the solvent contained in the particles is removed from the inside of the particles under appropriate conditions for the time for solvent removal, a plurality of gentle depressions are formed on the surface of the toner particles due to a partial internal pressure imbalance phenomenon occurring in the toner particles.

In addition to the above-described conditions, a plurality of depression forming conditions can be set by appropriately setting conditions such as an evaporation speed and a degree of vacuum, a liquid stirring speed and a liquid temperature.
This toner is a toner used as a developer for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like, and is a toner related to an electrophotographic developing device using the toner. Must have the characteristic balance and performance of

First, as a molecular weight design of a resin in order to express the basic performance of the toner, in the molecular weight distribution of the THF-soluble component of the polyester resin contained in the toner, the peak of the molecular weight is 1000 to 30,000, the component of 30,000 or more is 1% or more, and,
It is necessary that the number average molecular weight is 2,000 to 15,000. The peak and number average molecular weights are to ensure low-temperature fixation mainly. For components of 30,000 or more, oil-less fixation such as oil-less fixation in a fixing device or oil-less fixation with a small amount of oil applied to oil-less fixation with white and black toners. It can be a tool. Further, the fact that the THF-insoluble content of the toner binder contained in the toner is 10000% or more or the toner binder contained in the toner is 1 to 15%. Leads to increased durability.

Further, in the molecular weight distribution of the THF-soluble component of the polyester resin contained in the toner,
The fact that the content of 0 or less component is 0.1 to 5% or less is an important means for preventing a decrease in heat-resistant storage stability due to a low molecular weight component. If the amount of the component having a molecular weight of 1000 or less is too large, not only the heat-resistant storage stability but also the toner scattering occurs due to the deterioration of the charging performance due to long-term storage.
The toner of the present invention has an effective toner performance with respect to the transparency of the color toner because the toner has a small percentage of the wax surface existing in the fluidity and is finely dispersed. For this reason,
For these reasons, it is possible to design a small and inexpensive color copying machine or printer that does not need to supply fixing oil. Further, according to the method for producing the toner of the present invention, the release agent becomes a pulverized surface as a result of the conventional kneading and pulverizing method, and the presence of many of the particles on the outside is difficult. Decentralization became possible. Further, in the case of the suspension polymerization toner, the wax is encapsulated in the resin, so that the efficiency of the release effect is inferior to the amount of the wax as compared with the pulverization method. Also, since it can be easily dispersed in a polyester resin, which has been difficult to use as a binder resin in the conventional polymerization method, and the shape of the toner can be controlled, the powder characteristics are good and the A highly efficient toner can be designed. The toner of the present invention is capable of finely dispersing wax in the particles as compared with the pulverized toner, and it is difficult to realize a toner having a small particle diameter of 4 to 6 μm by the pulverization method in terms of productivity and cost. Can be easily achieved. The dispersion unit of the wax can be finely dispersed, so that a color image quality is high, and in particular, a toner excellent in OHP transmission image can be provided. Further, the dry toner of the present invention forms a superimposed transfer image by repeating the process of primary transferring the toner image formed on the image carrier to the endless intermediate transfer body several times, and forms the superimposed transfer image on the intermediate transfer body. The dry toner used in the intermediate transfer type image forming system in which the toner is secondary-transferred onto a transfer material can provide a toner which does not cause a transfer failure occurring at the time of transfer or an image reproducibility failure due to toner dust. . Further, the dry toner of the present invention has a transfer step of transferring a toner image carried on a toner carrier to a transfer material, and a cleaning step of cleaning the toner remaining on the toner image carrier surface after the transfer using a blade. In the image forming method, the dry toner developed in the present invention has a cleaning property at the level of a pulverized toner irregular-shaped toner, and the blade cleaning property, which is difficult for a spherical polymerized toner, can be greatly improved. This will be described in detail below.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The dry toner of the present invention is a dry toner containing at least a resin and a colorant, wherein the toner has a circularity of 0.960 to 1.000 and a plurality of concaves on the surface. Is a dry toner. In addition, as described above, the plurality of dents in the toner are 以下 or less of the toner particle diameter measured on an image (SEM image) taken with a scanning electron microscope (SEM image), and the long diameter of the dent is 1.0 to 5. 0 μm, preferably with a major axis of 1.0 μm or more, 90% or more of the depression and an upper limit of 5.
Dry toner characterized in that it does not exceed 0 μm.

(Explanation of Circularity) The circularity representing the degree of roundness of the dry toner of the present invention is determined by a flow type particle image analyzer FPI.
It is measured by A-2000 (manufactured by Sysmex Corporation). Circularity The average circularity of the toner is 0.960 to 1.000, and it is important to have a specific shape and shape distribution.
With an irregular shape having an average circularity of less than 0.960 and too far from a sphere, that is, a toner having an average circularity of less than 0.960 as referred to in the present invention, satisfactory transferability and high quality images without dust can be obtained. I can't. Irregular particles have many points of contact with a smooth medium on the photoreceptor, etc., and the charge concentrates on the tip of the protrusion, so the van der Waals force and the mirror image force have a higher adhesion force than the relatively spherical particles. . Therefore, in the electrostatic transfer process, spherical toner selectively moves in the toner in which irregular particles and spherical particles are mixed, and a character portion or a line portion image is missing. In addition, the remaining toner must be removed for the next developing step, which causes problems such as necessity of a cleaner device and low toner yield (the ratio of toner used for image formation). The circularity of the pulverized toner is usually 0.910 to 0.920.
It is. The specific method of measuring the circularity is shown below.

As a method of measuring the shape, a method of an optical detection zone in which a suspension containing particles is passed through a detection zone on a flat plate and a particle image is optically detected and analyzed by a CCD camera is suitable. is there. A toner having an average circularity of 0.960 or more, which is a value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particles, has a reproducible high-definition image with an appropriate density. It has proven to be effective in forming. More preferably, the average circularity is 0.980-1.
000. This value is obtained by the flow type particle image analyzer FPI.
It is a value measured as the average circularity by A-2000. As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably an alkylbenzenesulfonate, is added as a dispersant to 100 to 150 ml of water from which impurity solids have been removed in advance in a container, and further measurement is performed. Samples are 0.1-0.
Add about 5 g. The suspension in which the sample was dispersed was subjected to dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the dispersion concentration was adjusted to 300.
It can be obtained by measuring the shape and distribution of the toner with the above-mentioned device at 0 to 10,000 particles / μl.

The coefficient representing the degree of roundness of the toner is not limited to the circularity. For example, there is a shape factor called SF-1 measured by Luzex. SF-1
Is the average value of the amount represented by the following formula (1). SF-1 = L2 / S × π / 4 × 100 (1) (where L represents the maximum length of the toner particle diameter, and S represents the projected area of the toner particle.)

The sampling number is usually 50 or more,
Preferably, the number is 100 or more. The measurement is performed by an image processing analyzer called Luzex of an SEM (scanning electron microscope) image of a plurality of toner particles. The scanning electron microscope used may be a general-purpose one or an FE-SEM. The toner of the present invention falls in the range of 100 to 140 when the shape factor is determined by SF-1. The toner has a plurality of depressions on its surface, and the toner surface has a plurality of depressions observed by a scanning electron microscope S-2700 type SEM (SEM image manufactured by Hitachi). The major axis of the dent is 1/2 or less of the toner particle diameter, and 1.0 to 5.0.
.mu.m, preferably 90% or more of the depression when the major axis is 1.0 .mu.m or more, and the upper limit is not more than 5.0 .mu.m.
Particles whose particle diameter and dent are measurable are selected from ten screens photographed at a magnification of 2, and the long diameter of the dent and the toner particle diameter are measured. A plurality of pits having a diameter of 1.0 μm or less are liable to cause problems such as accumulation of silica in the same concave portions and release of silica after silica mixing, such as sticking to the photoreceptor, as in the case of the uneven toner. When the average particle diameter is larger than 5 μm, the stability of charging is lower than that of the irregularly pulverized toner. This is presumed to be due to the fact that the number of concave portions increased, and as a result, convex portions existed, which led to deterioration due to the influence of electrolytic concentration and stress during stirring of the developer. In addition, fog and durability have also been reduced. The average particle size of the toner is 4 to 9 μm. If it is 4 μm or less, there is a concern about the effect of toner floating on the human body. The dry toner is characterized in that the resin having the highest composition in the toner is a polyester resin.

The dry toner of the present invention is a dry toner having a plurality of depressions on the surface. At least the resin having the highest composition in the toner is a modified polyester resin, and is a composition containing a resin, a colorant, and a resin. Dissolving / dispersing the toner composition in an organic solvent, granulating the composition in an aqueous medium, and subjecting the toner composition containing the toner or prepolymer subjected to polyaddition reaction under granulation to an aqueous medium. Urea bonding is performed during the step of dispersing in the toner to form a polymer or crosslink, thereby obtaining a toner satisfying the fixing performance, the hot offset performance and the gloss performance.

When the apparatus is completely oil-free, a release agent represented by wax is added as a toner composition component. In some cases, the wax is contained not only in the toner but also in the roller. In this case, a sufficient effect can be obtained even with a small amount of wax or no wax. The larger the exposed area of the toner on the toner surface, the better the fixability. However, the toner tends to be irregular in shape, and is exposed to the surface. Known for side effects. Accordingly, in order to keep SF-1 at 120 or less, WAX tends to be spherical when the particle surface is less exposed and the particle surface is less exposed. Among dry toners, in particular, full-color toners are required to have not only basic properties such as heat-resistant storage stability, low-temperature fixability, and hot offset resistance, but also properties such as color reproducibility, transparency, and gloss that are incompatible with these properties. To achieve this, it is essential to improve the dispersibility of the colorant and wax (color reproducibility and transparency) and provide a sharp molecular weight distribution (transparency and gloss) while maintaining low-temperature fixability. And hot offset resistance must also be satisfied. The toner of the present invention has an advantage that the resin phase is separately granulated in water with an oil phase in which a resin and a colorant are separately dispersed, so that the polyester resin can be selected from the initial stage. It is. Particularly, in order to satisfy the above-mentioned color performance such as glossiness, transparency and color reproduction, it is a great merit to be able to use polyester in the composition. In addition, there is an environmental and odor advantage such that no monomer remains in a polymerization method involving a radical reaction. A charge controlling agent and a releasing agent are usually added to the composition for the purpose of imparting the charging performance and the releasing performance of the toner, but may be added together with the colorant in the toner of the present invention. Alternatively, each performance can be exhibited even if the toner particles are immobilized on the surface of the toner particles after preparation.

Regarding the hot offset resistance, various studies have been made to control the molecular weight distribution of the binder resin. For example, a binder resin having a wide molecular weight distribution may be used, or a polymer component having a molecular weight of hundreds of thousands or millions and a molecular weight of several This is a method of mixing resins having at least two molecular weight peaks of 1,000 to tens of thousands of low molecular components and separating the function of each component. If the polymer component has a crosslinked structure or is in a gel state, it is more effective for hot offset. However, in a full-color toner in which gloss and transparency are also required, it is not preferable to introduce a large amount of a polymer component. Since the toner of the present invention can elongate the polyester by the urea bond and increase the molecular weight, while adding transparency and gloss to the polymer, a suitable amount of a high molecular weight component effective for hot offset of 1% or more is added, so that the toner has an excellent resistance to hot offset. It has become possible to achieve hot offset properties.

The toner composition is granulated in an aqueous medium, and the molecular weight distribution of the toner binder component subjected to the polycondensation reaction under the granulation is measured by the following method. About 1 toner
g was precisely weighed in an Erlenmeyer flask, and 10 to 20 g of THF (tetrahydrofuran) was added thereto.
% THF solution. The column was stabilized in a heat chamber at 40 ° C., and THF was flowed through the column at this temperature at a flow rate of 1 ml / min as a solvent.
Inject 20 μl of sample solution. The molecular weight of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from a monodisperse polystyrene standard sample and the retention time. A calibration curve is created using a polystyrene standard sample. As the monodisperse polystyrene standard sample, for example, one having a molecular weight of 2.7 × 10 ^{2 to} 6.2 × 10 ⁶ manufactured by Tosoh Corporation is used. A refractive index (RI) detector is used as the detector. Examples of the column include TSKgel and G10 manufactured by Tosoh Corporation.
00H, G2000H, G2500H, G3000H,
G4000H, G5000H, G6000H, G700
0H and GMH are used in combination.

The main peak molecular weight is usually 1000-3
0000, preferably 1500 to 10000, more preferably 2000 to 8000. When the amount of the component having a molecular weight of less than 1000 increases, the heat-resistant storage stability tends to deteriorate, and when the component having a molecular weight of 30,000 or more increases, the low-temperature fixability tends to simply decrease. The content of the component having a molecular weight of 30,000 or more is 1% or more, and varies depending on the toner material, but is preferably 3 to 6%. If it is less than 1%, sufficient hot offset resistance cannot be obtained, and if it is 10% or more, the gloss and the transparency may deteriorate.

Mn is 2000 to 15000 and Mw / Mn
Is preferably 5 or less. If it is 5 or more, sharp melt properties are lacking and gloss is impaired. Also, the THF insoluble content is 1 to
The use of a polyester resin containing 10% leads to an improvement in hot offset. The THF-insoluble content is effective for hot offset in color toner, but it is definitely negative for glossiness and transparency of OHP, but it is effective within 1 to 10% for widening the mold release width. There is also.

The measuring method is described below. THF insoluble content measurement method About 1.0 g (A) of resin or toner is weighed. This is T
Add about 50 g of FT and let stand at 20 ° C. for 24 hours.

This is first separated by centrifugation and filtered using a filter paper for quantification of JIS standard (P3801) 5 type C.
The solvent content of this filtrate is vacuum dried, and only the resin content is the residual amount (B)
Is measured.

This residual amount is the THF dissolved component. THF
The insoluble content (%) is determined by the following equation. THF-insoluble content (%) = (AB) / A In the case of toner, the amount of THF-insoluble component (W1) and the amount of THF-soluble component (W2) other than the resin are determined by a known method, for example, a thermal weight loss method by the TG method. Check it out and find it from the following formula. THF insoluble matter (%) = (ABW2) / (AW1)
-W2) × 100 Subsequently, the used toner will be described.

A toner composition comprising at least a resin and a colorant is dissolved or dispersed in an organic solvent, and the dissolved or dispersed material is dispersed in an aqueous medium in the presence of an inorganic dispersant or a fine particle polymer. In a method for producing a dry toner in which a dispersion is subjected to a polyaddition reaction and the solvent of an emulsified dispersion obtained is removed, and a toner composition comprising a polyester resin is further dispersed in an aqueous medium to form toner particles. In the presence of an inorganic dispersant or a fine particle polymer, an isocyanate group-containing prepolymer dispersed in an aqueous medium is subjected to an elongation reaction and a crosslinking reaction with amines, and the solvent of the obtained emulsified dispersion is removed. It is characterized by: Specific examples of the production method include a reaction product of a polyester prepolymer (A) having an isocyanate group and an amine (B). In addition, as a polyester prepolymer (A) having an isocyanate group, a polyester which is a polycondensate of a polyol (1) and a polycarboxylic acid (2) and has an active hydrogen group is further reacted with a polyisocyanate (3). Things. Examples of the active hydrogen group contained in the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, and a mercapto group. Of these, an alcoholic hydroxyl group is preferable.

As the polyol (1), diol (1)
-1) and tri- or higher valent polyol (1-2). (1-1) alone or (1-1) and a small amount of (1-)
Mixtures of 2) are preferred. As the diol (1-1), alkylene glycol (ethylene glycol, 1,
2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc .; alkylene ether glycols (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetra) Alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); alkylene oxides of the above alicyclic diols (ethylene Oxides, propylene oxide, butylene oxide, etc.) adducts; alkylene oxides of the above bisphenols (ethylene oxide, propylene oxide, butyl oxide) Adducts and the like. Of these, preferred are those having 2 carbon atoms.
~ 12 alkylene glycol and alkylene oxide adducts of bisphenols, particularly preferred are alkylene oxide adducts of bisphenols,
And a combination thereof with an alkylene glycol having 2 to 12 carbon atoms. Examples of the trivalent or higher polyol (1-2) include polyhydric aliphatic alcohols of 3 to 8 or higher (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol P
A, phenol novolak, cresol novolak, etc.);

The polycarboxylic acid (2) includes dicarboxylic acid (2-1) and tricarboxylic or higher polycarboxylic acid (2-
2), and (2-1) alone or a mixture of (2-1) and a small amount of (2-2) is preferable. Examples of the dicarboxylic acids (2-1) include alkylenedicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) , Naphthalenedicarboxylic acid, etc.). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (2-2) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). The polycarboxylic acid (2) may be reacted with the polyol (1) using the above-mentioned acid anhydride or lower alkyl ester (eg, methyl ester, ethyl ester, isopropyl ester).

Polyol (1) and polycarboxylic acid (2)
Is usually 2/1 to 1/1, as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH].
1, preferably 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyisocyanate (3) include aliphatic polyisocyanates (such as tetramethylene diisocyanate, hexamethylene diisocyanate, and 2,6-diisocyanatomethylcaproate); alicyclic polyisocyanates (such as isophorone diisocyanate and cyclohexylmethane diisocyanate). Aromatic diisocyanates (such as tolylene diisocyanate and diphenylmethane diisocyanate); araliphatic diisocyanates (such as α, α, α ′, α′-tetramethylxylylene diisocyanate); isocyanurates; , Caprolactam and the like; and combinations of two or more of these.

[0038] The ratio of the polyisocyanate (3) is
Polyester having cyanate group [NCO] and hydroxyl group
As the equivalent ratio [NCO] / [OH] of hydroxyl group [OH]
5/1 to 1/1, preferably 4/1 to 1.2 / 1, further
It is preferably 2.5 / 1 to 1.5 / 1. [NCO]
If / [OH] exceeds 5, the low-temperature fixability deteriorates. [NC
If the molar ratio of O] is less than 1, the urethane in the modified polyester
A) content decreases, and hot offset resistance deteriorates.
In prepolymer (A) having terminal isocyanate group
The content of the polyisocyanate (3) component is usually
0.5 to 40% by weight, preferably 1 to 30% by weight,
Preferably 2 to 20% by weight. Less than 0.5% by weight
In this case, the hot offset resistance deteriorates and
This is disadvantageous in terms of compatibility between storage stability and low-temperature fixability. Also, 4
If it exceeds 0% by weight, the low-temperature fixability deteriorates.

The number of isocyanate groups per molecule in the prepolymer (A) having isocyanate groups is usually at least one, preferably 1.5 to 3 on average, and more preferably 1.8 to 2 on average. .5. If the number is less than one per molecule, the molecular weight of the urea-modified polyester becomes low, and the hot offset resistance deteriorates.

As the amines (B), diamines (B
1) Triamine or higher polyamine (B2), amino alcohol (B3), aminomercaptan (B4), amino acid (B5), and those obtained by blocking amino groups of B1 to B5 (B6). Examples of the diamine (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,
3 ′ dimethyldicyclohexylmethane, diaminecyclohexane, isophoronediamine, etc.); and aliphatic diamines (ethylenediamine, tetramethylenediamine,
Hexamethylene diamine). Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of the aminomercaptan (B4) include aminoethylmercaptan and aminopropylmercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compounds (B6) in which the amino groups of B1 to B5 are blocked include the amines and ketones of B1 to B5 (acetone, methyl ethyl ketone,
Ketimine compounds and oxazoline compounds obtained from methyl isobutyl ketone. Preferred of these amines (B) are B1 and a mixture of B1 and a small amount of B2.

Further, if necessary, the molecular weight of the urea-modified polyester can be adjusted by using an elongation terminator. Examples of the elongation terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

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

The urea-modified polyester of the present invention (i)
Is produced by a prepolymer method or the like. The number average molecular weight of the polyester used for urea modification is usually 200
It is 0-15000, preferably 2000-10000, more preferably 2000-8000. 15000
Exceeding the range deteriorates the low-temperature fixability and the gloss when used in a full-color device. If it is less than 2,000, the storage stability is reduced due to the influence of low molecular weight components.

In the present invention, not only the polyester (i) modified by the urea bond alone but also the polyester (ii) which is not modified can be contained as a toner binder component together with this (i).
When (ii) is used in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, and it is preferable to use alone. Examples of (ii) include the same polycondensates of the polyol (1) and the polycarboxylic acid (2) as in the polyester component (i), and preferred ones are also the same as (i). Further, (ii) may be not only an unmodified polyester but also a polyester modified with a chemical bond other than a urea bond, for example, it may be modified with a urethane bond.
It is preferable that (i) and (ii) are at least partially compatible with each other in view of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. (I) and (ii) when containing (ii)
Is usually 5/95 to 80/20, preferably 5/95 to 80/20.
/ 95-30 / 70, more preferably 5 / 95-25
/ 75, particularly preferably 7/93 to 20/80.
When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated and the heat storage stability and the low-temperature fixability are disadvantageous.

The hydroxyl value of (ii) is preferably 5 or more, and the acid value of (ii) is usually from 1 to 30, preferably from 5 to 5.
20. By having an acid value, it tends to be negatively chargeable.

In the present invention, the glass transition point (Tg) of the toner binder is usually from 55 to 75 ° C., preferably from 55 to 75 ° C.
６５65 ° C. If the temperature is lower than 50 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 75 ° C., the low-temperature fixability becomes insufficient.
Due to the coexistence of a urea-modified polyester resin, the dry toner of the present invention tends to have good heat-resistant storage stability even at a low glass transition point, as compared with known polyester-based toners.

(Releasing Agent) As the wax used in the toner of the present invention, a low melting point wax having a melting point of 50 to 120 ° C. is more effectively used as a releasing agent in the dispersion with the binder resin than the fixing roller. It works with the toner interface, thereby exhibiting an effect on high-temperature offset without applying a release agent such as oil to the fixing roller. In addition, the melting point of the wax in the present invention was defined as a maximum endothermic peak by a differential scanning calorimeter (DSC).

The following materials can be used as the wax component that functions as a release agent that can be used in the present invention. That is, as specific examples, as waxes and waxes, carnauba wax, vegetable wax such as cotton wax, wood wax, rice wax, animal wax such as beeswax and lanolin, mineral wax such as ozokerite and celsin. And petroleum waxes such as paraffin, microcrystalline, petrolatum and the like. In addition to these natural waxes, there may be mentioned synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones and ethers. Further, 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride, fatty acid amides such as chlorinated hydrocarbons, and poly n-stearyl methacrylate, which is a low molecular weight crystalline polymer resin,
Homopolymer or copolymer of polyacrylate such as poly-n-lauryl methacrylate (eg, copolymer of n-stearyl acrylate-ethyl methacrylate)
For example, a crystalline polymer having a long alkyl group in the side chain can be used.

(Colorant) The present inventors have studied the fluidity of toner,
After intensive studies on transferability, fixing properties, hot offset properties, high image quality, heat-resistant storage stability, high image density, and particularly glossiness of color toners and transparency with OHP, the modified polyester was converted into a toner binder at least. It has been discovered that the modified polyester exhibits an effect as an excellent dispersant for the pigment particles forming the colorant in the dry toner containing as a pigment, and a specific dispersed particle size of the pigment particles can be obtained. That is, the binder resin according to the present invention is, for example, a modified polyester obtained by increasing the molecular weight of a polyester resin by urethane bonding with urethane, and the low-temperature fixability of the polyester resin and the transparency of the color toner can be secured as a toner binder. The basic molecules of the urea bond exhibit a strong dispersing power for dispersing the pigment in the solvent, thereby enabling a high degree of pigment dispersing. This is presumably because the basic molecules of the basic polyester having a urea bond enable high dispersibility in a solvent due to the action of both the pigment and the colorant.

That is, the dispersed particle diameter of the pigment colorant in the toner particles at this time is 0.5 μm or less in number average diameter, and the number ratio of the number average diameter of 0.7 μm or more is 5% by number.
By controlling the following, high image quality can be achieved with a small particle size toner, and transparency at OHP with a full color toner can be achieved at a high level while fixing property is secured. As for the dispersibility of the pigment-based colorant, the dispersed particle diameter of the pigment-based colorant can be further reduced by using a pigment-based dispersant in which the pigment-based colorant is dispersed in advance. That is, a toner excellent in transparency in a full-color toner can be obtained by adjusting the above-mentioned toner components using a master batch in which a pigment-based coloring agent having a high concentration is mixed and kneaded with a resin under a high shearing force.

That is, in a master batch of a colorant in which at least a colorant is dispersed in a resin, and in a dry toner containing at least a modified polyester having a urea bond as a toner binder using the masterbatch, the dispersed particle size is It has been found that the number average diameter is 0.3 μm or less, and that the number ratio with the number average diameter of 0.5 μm or more is achieved at 10 number% or less. That is, if the number average particle size of the pigment particles in the small particle size toner exceeds 0.5 μm, the image resolving power is deteriorated, and it is not suitable for a recent digital type high quality image. In addition, not only the average value but also the presence of a pigment-based coloring agent having a number average diameter of 0.7 μm or more lowers the image resolution, so that the number ratio is limited to 10% by number or less. In particular, in the case of color toners, it is necessary to further reduce the dispersed particle size of the pigment coloring material in order to faithfully perform resolution and color reproduction and obtain transparency in OHP. That is, when the dispersed particle diameter is 0.3 μm or more in number average diameter, color reproducibility and transparency in a full-color machine are reduced. Further, not only the average particle size but also the distribution of the dispersed particle size affects the color reproducibility and transparency of the color toner. When the number ratio of 0.5 μm or more is 10% or more, the color reproducibility and transparency are reduced. Measurement of dispersed particle size of pigment-based coloring material: A measurement sample is prepared in which the toner is embedded in an epoxy resin and ultrathin sliced into a toner of about 100 μm using a Microtome MT6000-XL (Taiwa Shoji).

Using an electron microscope Hitachi H-9000NA
A TEM photograph is obtained at an acceleration voltage of 100 kV using R.
The image information is converted into image data by an image processing analyzer LUZEXIII of IMAGE ANALYZER.
The target pigment-based coloring material particles were randomly sampled for particles having a particle size of 0.1 μm or more.
The measurement was repeated until the number of times exceeded, and the average particle size and distribution were determined.

As the colorant of the present invention, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, Yellow iron oxide, loess, graphite, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN,
R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow B
GL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Vermilion, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline Red, Risor Fast Scarlet G , Brilliant Fast Scarlet, Brilliant Carmine B
S, permanent red (F2R, F4R, FRL, F
RLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G,
Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B,
Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thio Indigo Maroon, Oil Red, quinacridone red, pyrazolone red, polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, Victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Navy Blue, Anthraquinone Blue, Fast Ioretto B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, viridian, emerald green, Pigment Green B, Naphthol Green B, green gold, acid green lake,
Malachite green lake, phthalocyanine green,
Anthraquinone green, titanium oxide, zinc white, lithopone and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 1% by weight based on the toner.
0% by weight.

The coloring agent used in the present invention can be used as a masterbatch combined with a resin. Examples of the binder resin to be produced or kneaded with the master batch include, in addition to the above-mentioned modified and unmodified polyester resins, polymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene, and the like; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer,
Styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl Styrene copolymers such as ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers Coalescence; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene,
Polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin Wax, etc., can be used alone or in combination.

In the present masterbatch, a masterbatch can be obtained by mixing and kneading the resin for the masterbatch and the colorant with high shearing force. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin.
The so-called flushing method is also known as a flushing method in which an aqueous paste containing water of a coloring agent is mixed and kneaded together with a resin and an organic solvent, the coloring agent is transferred to the resin side, and moisture and an organic solvent component are removed. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high-shear dispersion device such as a three-roll mill is preferably used.

(Charge Control Agent) The toner of the present invention may contain a charge control agent if necessary. Known charge control agents can be used, for example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified Quaternary ammonium salts), alkylamides, phosphorus alone or compounds, tungsten alone or compounds, fluorine-based activators, salicylic acid metal salts, and salicylic acid derivative metal salts. Specifically, bontron 03 of a nigrosine dye, bontron P-51 of a quaternary ammonium salt, bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid-based metal complex, and E-82 of a salicylic acid-based metal complex 8
4. E-89 of a phenolic condensate (above, manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (above, manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Salt Copy Charge PSY
VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt N
EG VP2036, copy charge NX VP43
LRA-901 (manufactured by Hoechst), LR-147, a boron complex (manufactured by Nippon Kalit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, other sulfonic acid groups, carboxyl groups, quaternary A high molecular compound having a functional group such as an ammonium salt is exemplified.

In the present invention, the amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as required, and the toner production method including the dispersion method, and is uniquely limited. Although not to be preferred, preferably 0.1 to 100 parts by weight of the binder resin
Used in the range of 10 parts by weight. Preferably, 0.2 to
A range of 5 parts by weight is good. If the amount exceeds 10 parts by weight, the chargeability of the toner is too large, the effect of the main charge control agent is reduced, the electrostatic attraction with the developing roller increases, the fluidity of the developer decreases, and the image density decreases. Causes a decline. These charge control agents and release agents can be melt-kneaded together with the masterbatch and the resin, or of course, may be added when dissolved and dispersed in an organic solvent.

(External Additive) As the external additive for assisting the fluidity, developability and chargeability of the colored particles obtained in the present invention, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 m, and particularly preferably 5 nm to 500 nm. The specific surface area by the BET method is 20 to 500 m.
It is preferably ² / g. The use ratio of the inorganic fine particles is 0.01 to 5% by weight of the toner,
It is preferably from 1 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, and diatomaceous Earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide,
Silicon nitride and the like can be given. Among them, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination as the fluidity imparting agent. In particular, when agitating and mixing using both particles having an average particle diameter of 50 mμ or less, the electrostatic force and the van der Waals force with the toner are remarkably improved. It is clear that even with the stirring and mixing inside the developing machine, the fluidity-imparting agent does not desorb from the toner, good image quality without fireflies and the like is obtained, and the transfer residual toner is further reduced. became.

The titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate in charge rising characteristics. Therefore, when the amount of added titanium oxide fine particles is larger than the added amount of silica fine particles, side effects thereof are caused. Is likely to be greater. However, the addition amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is 0.3 to 1.
In the range of 5 wt%, it was found that the charge rising characteristics were not significantly impaired and desired charge rising characteristics were obtained. That is, even when copying was repeated, stable image quality was obtained and toner blowing could be suppressed. . (Production Method of Modified Polyester Resin) Resin for a toner binder can be produced by the following method or the like. The polyol (1) and the polycarboxylic acid (2) are heated to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the resulting water is distilled off under reduced pressure if necessary. Thus, a polyester having a hydroxyl group is obtained. Next, at 40 to 140 ° C., the polyisocyanate (3) is reacted therewith to obtain a prepolymer (A) having an isocyanate group. Further, (A) is reacted with an amine (B) at 0 to 140 ° C. to obtain a urea-modified polyester.
When reacting (3) and when reacting (A) and (B), a solvent can be used if necessary. Solvents that can be used include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And the like (e.g., tetrahydrofuran), which are inert to isocyanate (3). When the polyester (ii) not modified with a urea bond is used in combination, (ii) is produced in the same manner as the polyester having a hydroxyl group, and this is dissolved in the solution after the completion of the reaction (i) and mixed. I do.

The dry toner can be produced by the following method, but is not limited thereto. (Method of producing toner in an aqueous medium) The term "modified polyester resin" as used herein means that a polyester resin has a bonding group other than an ester bond, or a resin component having a different composition in the polyester resin has a covalent bond, an ionic bond, or the like. A state where the polyester terminal is reacted with something other than an ester bond. Specifically, an acid group at the terminal,
It refers to one in which a functional group such as an isocyanate group that reacts with a hydroxyl group is introduced, and further reacted with an active hydrogen compound to modify the terminal.

Further, if the compound has a plurality of active hydrogen groups, it is a compound in which polyester terminals are bonded to each other (such as a urea-modified polyester and a urethane-modified polyester). Group, radical polymerization occurs from it, and carbon-
Those in which a graft component of a carbon bond is introduced (styrene-modified, acryl-modified polyester, etc.) In addition, those obtained by copolymerizing resin components having different constitutions in the main chain of the polyester. For example, those copolymerized with a silicone resin having a terminal modified by a carboxyl group, a hydroxyl group, an epoxy group, or a mercapto group (such as a silicone-modified polyester) The aqueous medium used in the present invention may be water alone,
A solvent miscible with water can be used in combination. Examples of the miscible solvent include alcohols (eg, methanol, isopropanol, ethylene glycol), dimethylformamide, tetrahydrofuran, cellosolves (eg, methylcellosolve), and lower ketones (eg, acetone, methylethylketone).

The toner particles may be formed by reacting a dispersion comprising a prepolymer (A) having isocyanate groups with an amine (B) in an aqueous medium, or may be prepared in advance from a urea-modified polyester (i). ) May be used. As a method for stably forming a dispersion composed of the urea-modified polyester (i) or the prepolymer (A) in an aqueous medium, a toner raw material comprising the urea-modified polyester (i) or the prepolymer (A) in an aqueous medium is used. And dispersing by shearing force. The prepolymer (A) and another toner composition (hereinafter, referred to as toner raw material) such as a colorant, a colorant masterbatch, a release agent, a charge control agent, and an unmodified polyester resin are dispersed in an aqueous medium. The toner may be mixed at the time of formation, but it is more preferable to mix the toner raw materials in advance and then add and disperse the mixture in an aqueous medium.
Further, in the present invention, other toner raw materials such as a colorant, a release agent, and a charge control agent do not necessarily have to be mixed when forming particles in an aqueous medium. May be added. For example, after forming particles containing no coloring agent, a coloring agent can be added by a known dyeing method.

The dispersion method is not particularly limited, but known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. In order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing type is preferred. When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm
m, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but is usually 0.1 to 5 minutes in the case of a batch system. The temperature at the time of dispersion is usually 0
To 150 ° C (under pressure), preferably 40 to 98 ° C.
Higher temperatures are preferred because the dispersion of the urea-modified polyester (i) or prepolymer (A) has a lower viscosity and is easier to disperse.

The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts of the toner composition containing the urea-modified polyester (i) and the prepolymer (A). If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle size cannot be obtained. If it exceeds 20,000 parts by weight, it is not economical. Further, if necessary, a dispersant can be used. The use of a dispersant is preferred in that the particle size distribution becomes sharp and the dispersion is stable.

As a dispersant for emulsifying and dispersing the oily phase in which the toner composition is dispersed in a liquid containing water, an anionic surfactant such as an alkylbenzene sulfonate, an α-olefin sulfonate or a phosphate ester is used. , Alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt forms such as imidazoline, alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, chlorides Nonionic surfactants such as quaternary ammonium salt-type cationic surfactants such as benzethonium, fatty acid amide derivatives and polyhydric alcohol derivatives such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine Arukiru N, amphoteric surfactants such as N-dimethyl ammonium betaine and the like.

By using a surfactant having a fluoroalkyl group, the effect can be improved with a very small amount. Anionic surfactants having a fluoroalkyl group preferably used include those having 2 to 1 carbon atoms.
0 fluoroalkylcarboxylic acid and its metal salt, disodium perfluorooctanesulfonylglutamate, 31- [omega-fluoroalkyl (C6-C11)
Sodium oxy] -1-alkyl (C3-C4) sulfonate, 3- [omega-fluoroalkanoyl (C6-
C8) 1-N-ethylamino] -1-propanesulfonic acid sodium salt, fluoroalkyl (C11 to C20) carboxylic acid and metal salt, perfluoroalkyl carboxylic acid (C7 to C13) and its metal salt, perfluoroalkyl (C4 to C12) Sulfonic acid and its metal salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, perfluoroalkyl (C6-C
10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, and the like.

The trade names include Surflon S-111,
S-112, S-113 (made by Asahi Glass Co., Ltd.), Florard F
C-93, FC-95, FC-98, FC-129 (manufactured by Sumitomo 3M), Unidyne DS-101, DS-10
2, (manufactured by Taikin Industries, Ltd.), Megafac F110,
F120, F-113, F-191, F-812, F
-833 (manufactured by Dainippon Ink and Chemicals), Ectop EF-10
2, 103, 104, 105, 112, 123A, 12
3B, 306A, 501, 201, 204 (manufactured by Tochem Products Co., Ltd.), Futuregent F-100, F15
0 (manufactured by Neos).

Examples of the cationic surfactant include an aliphatic primary or secondary amine acid having a fluoroalkyl group and an aliphatic quaternary such as a perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt.
Grade ammonium salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names are Surflon S-121 (manufactured by Asahi Glass Co., Ltd.), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 ( Manufactured by Daikin Industries, Ltd.), Megafac F-15
0, F-824 (manufactured by Dainippon Ink), Ektop EF
-132 (manufactured by Tochem Products Co., Ltd.) and Futergent F-1300 (manufactured by Neos Corporation).

In order to form a depression having a particle diameter of 以下 or less and a particle size of 1 to 5 μm on the surface of the toner particles, especially an inorganic compound dispersant hardly soluble in water, for example, phosphoric acid By using tricalcium, calcium carbonate, titanium oxide, colloidal silica, hydroxyapatite, or the like, or in combination with another dispersant, it becomes possible to produce hollow toner particles in combination with solvent removal conditions.
The same effect as that of the inorganic dispersant was also confirmed for the fine particle polymer. For example, MMA polymer fine particles 1 and 3 μm, styrene fine particles 0.5 and 2 μm, styrene-acrylonitrile fine particle polymer 1
μm, PB-200H (manufactured by Kao) SGP (Soken), Techno Polymer SB (Sekisui Plastics), SGP-3G (Soken) Microwaal (Sekisui Fine Chemical), and also used in combination with the above inorganic dispersant and fine particle polymer As the dispersing agent usable in the present invention, the dispersed droplets may be stabilized by a polymer-based protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, acids such as maleic acid or maleic anhydride, or a (meth) acrylic monomer containing a hydroxyl group, For example, β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate,
Γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-21-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerin monoacrylate Esters, glycerin monomethacrylate, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or vinyl alcohol Esters of compounds containing a carboxyl group, such as vinyl acetate, vinyl propionate, vinyl butyrate, etc., acrylamide, methacryl Homopolymers such as amides, diacetone acrylamides or methylol compounds thereof, acid chlorides such as acrylic acid chloride and methacrylic acid chloride, nitrogen atoms such as pinyl pyridine, vinyl pyrrolidone, vinyl imidazole and ethylene imine, or those having a heterocyclic ring thereof Or a copolymer,
Polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene Polyoxyethylenes such as stearyl phenyl ester and polyoxyethylene nonyl phenyl ester, methylcellulose,
Cellulose such as hydroxyethylcellulose and hydroxypropylcellulose can be used.

In order to remove the organic solvent from the obtained emulsified dispersion, a method in which the temperature of the whole system is gradually raised and the organic solvent in the droplets is completely removed by evaporation in a short time can be adopted. . When an acid such as a calcium phosphate salt or an alkali-soluble substance is used as the dispersion stabilizer, the calcium phosphate salt is removed from the fine particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. I do. In addition, it can be removed by an operation such as decomposition with an enzyme.

When a dispersant is used, the dispersant may remain on the surface of the toner particles, but it is preferable to remove the dispersant by washing after the elongation and / or crosslinking reaction from the viewpoint of the charged surface of the toner.

Further, in order to lower the viscosity of the toner composition, a solvent in which the urea-modified polyester (i) or (A) is soluble can be used. The use of a solvent is preferred in that the particle size distribution becomes sharp. The solvent has a boiling point of 1
It is preferable that the solvent be volatile at a temperature of less than 00 ° C. because it is easily removed. Examples of the solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-
Dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene,
Dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and methylene chloride,
Halogenated hydrocarbons such as 1,2-dichloroethane, chloroform and carbon tetrachloride are preferred. Prepolymer (A)
The amount of the solvent to 100 parts is usually 0 to 300 parts,
Preferably 0-100 parts, more preferably 25-70
Department. When a solvent is used, after the elongation and / or crosslinking reaction, it is removed by heating under normal pressure or reduced pressure.

The sphericity of the toner and the state of formation of the depressions on the surface of the toner particles can be appropriately adjusted by the solvent removal conditions. In order to adjust the depression to an appropriate diameter, it is necessary to set desolvation conditions in addition to the above-mentioned dispersant. The condition is that the oil phase solid content of the liquid emulsified and dispersed in an aqueous medium is 10%.
It is necessary to reduce the solvent to about 50% and to remove the solvent within about 60 minutes per 200 g. This is presumably because the solvent contained in the oil phase evaporates in a short time, resulting in an unbalanced volume contraction of the oil phase. When the solid content of the oil phase is 50% or more, the evaporation solvent is small and the conditions under which volume shrinkage occurs are reduced. As the time becomes longer, the volume shrinkage is less likely to occur, so that the depression is reduced. However, the above conditions are not absolute conditions,
It is also necessary to balance the temperature and the solvent removal time.

The elongation and / or cross-linking reaction time is selected depending on the reactivity of the isocyanate group structure of the prepolymer (A) and the amines (B). 24 hours. The reaction temperature is generally 0-150 ° C, preferably 4 ° C.
0-98 ° C. In addition, a known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

The particle size distribution at the time of emulsification and dispersion is wide, and when washing and drying are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classifying into a desired particle size distribution. In the classification operation, fine particles can be removed in the liquid by cyclone, decanter, centrifugation, or the like. Of course, a classification operation may be performed after obtaining the powder after drying, but it is preferable to perform the classification operation in a liquid in terms of efficiency. The obtained unnecessary fine particles or coarse particles can be returned to the kneading step again and used for forming particles. At this time, the fine particles or coarse particles may be in a wet state. The dispersant used is preferably removed from the obtained dispersion as much as possible, but is preferably performed simultaneously with the classification operation described above.

The obtained dried toner powder is mixed with different kinds of particles such as release agent fine particles, charge control fine particles, fluidizing agent fine particles, and colorant fine particles, or a mechanical impact force is applied to the mixed powder. By giving, the particles can be immobilized and fused on the surface, and detachment of foreign particles from the surface of the obtained composite particles can be prevented.

As a specific means, a method of applying an impact force to the mixture by a blade rotating at a high speed, charging the mixture into a high-speed air stream, accelerating the particles, and causing the particles or composite particles to collide with an appropriate collision plate. There are methods. Apparatuses include a modified Angmill (Hosokawa Micron), an I-type mill (Nippon Pneumatic), a device with reduced grinding air pressure, a hybridization system (Nara Machinery Co., Ltd.), Kryptron System (Kawasaki Heavy Industries), automatic mortar, and the like.

(Two-Component Carrier) The toner of the present invention
When used in a component-based developer, it may be mixed with a magnetic carrier, and the content ratio of the carrier and the toner in the developer is preferably from 1 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier. As the magnetic carrier, a particle diameter of 20 to 2
Iron powder, ferrite powder, magnetite powder,
A conventionally known carrier such as a magnetic resin carrier can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Also, polyvinyl and polyvinylidene resins, for example, acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins such as polystyrene resins and styrene acrylic copolymer resins, polychlorinated resins Halogenated olefin resin such as vinyl, polyester resin such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resin, polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin,
Polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene, vinylidene fluoride and non-fluorinated A fluoroterpolymer such as a terpolymer with a monomer, and a silicone resin can be used. If necessary, a conductive powder or the like may be contained in the coating resin. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide,
Zinc oxide and the like can be used. These conductive powders preferably have an average particle size of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control the electric resistance.

The toner of the present invention can be used as a one-component magnetic toner or a non-magnetic toner without using a carrier. Next, the cleaning device will be described.

FIG. 4 is a sectional view showing a main part of the image forming apparatus. In this example, an electrophotographic copying machine is illustrated as an image forming apparatus. In FIG. 4, reference numeral 1 denotes a photosensitive drum as a latent image carrier, which rotates in a direction indicated by an arrow in FIG.
A charger 2 is disposed around the periphery, and a laser beam 3 corresponding to an image read from a document is irradiated as exposure means. Further, a developing device 4, a paper feeding unit 7, a transfer device 5, a cleaning device 6, and a discharging lamp 9 are arranged around the photoreceptor 1. The developing device 4 further includes developing rollers 41 and 42 and a paddle-shaped stirring member 43.
, The stirring member 44, the doctor 45, and the toner supply unit 4
6 and a supply roller 47. The cleaning means 6 has a cleaning brush 61 and a cleaning blade 62. Note that members 81 and 82 disposed above and below the developing device 4 are guide rails for attaching and detaching or supporting the developing device.

The life of the cleaning blade 61 of the cleaning device can be detected. The cleaning blade 61 is always in contact with the photoconductor during image formation, and wears as the photoconductor rotates. When the cleaning blade is worn, the function of removing the residual toner on the photoreceptor surface is reduced, and the quality of the copied image is deteriorated. Also, if the toner is close to a true sphere and the fluidity is improved compared to the pulverized toner without abrasion, the transferability is improved, but in cleaning, it passes through the installed blade and cleaning failure easily occurs, which is a problem of polymerized toner. You. To solve this problem, the circularity of the toner of the present invention is 0.960 to 1.000.
The dry toner having a plurality of depressions has less residual toner than the blade cleaning method, and can be cleaned well even when the toner has a circularity of 0.96 or more with respect to the cleaning brush. In addition, there was little deterioration with respect to abrasion of the cleaning blade. This is presumed to be related to the flexibility of the polyester resin.

[0082]

The present invention will be further described with reference to the following examples.
The present invention is not limited to this. Hereinafter, "parts" indicates parts by weight. Table 1 shows the toner used in each example.

[0083]

[Table 1]

Example 1 (Synthesis of Toner Binder) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 690 parts of a 2-mol adduct of bisphenol A ethylene oxide and 256 of isophthalic acid were added.
Parts and 2 parts of dibutyltin oxide at normal pressure of 23
The reaction was carried out at 0 ° C. for 8 hours and further at a reduced pressure of 10 to 15 mmHg for 5 hours, and then cooled to 160 ° C.
8 parts of phthalic anhydride was added and reacted for 2 hours. Then
The mixture was cooled to 80 ° C. and reacted with 188 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain an isocyanate-containing prepolymer (1). Next, 267 parts of the prepolymer (1) and 14 parts of isophoronediamine were reacted at 50 ° C. for 2 hours to obtain a urea-modified polyester (1). In the same manner as above, 690 parts of a bisphenol A ethylene oxide 2 mol adduct and 256 parts of terephthalic acid are polycondensed at 230 ° C. for 8 hours under normal pressure, and then 10 to 15 mm
The reaction was carried out at a reduced pressure of Hg for 5 hours to obtain an unmodified polyester (a). Urea-modified polyester (1) 1
00 parts and 900 parts of the unmodified polyester (a) were dissolved and mixed in 1800 parts of an ethyl acetate solvent to obtain a solution of the toner binder (1) in ethyl acetate. Part of the resultant was dried under reduced pressure to isolate the toner binder (1). (Preparation of toner) In a beaker, 210 parts of the above-mentioned toner binder (1) in ethyl acetate solution, 2 parts of an iron-containing monoazo dye (T-77 manufactured by Hodogaya Chemical) as a charge control agent, and 4 parts of copper phthalocyanine blue pigment were placed in a beaker. The mixture was stirred at 12000 rpm with a TK homomixer at 12,000 rpm, and was uniformly dissolved and dispersed. In a beaker, 265 parts of ion-exchanged water, 260 parts of a 10% aqueous solution of tricalcium phosphate and 0.2 part of sodium dodecylbenzenesulfonate were put and uniformly dissolved.
Then, the temperature was raised to 60 ° C., and 1200
The mixture was stirred at 0 rpm, 500 g of the suspension was transferred to a flask equipped with a thermometer capable of distillation, and the solvent was removed at 40 to 50 ° C. under reduced pressure for 45 to 50 minutes while stirring. Then filter off,
After washing and drying, air classification was performed to obtain toner particles having spherical depressions. Then, 0.5 part of hydrophobic silica and 0.5 part of hydrophobic titanium oxide were mixed with 100 parts of the toner particles using a Henschel mixer to obtain the toner (1) of the present invention. The obtained GPC chromatogram is shown in FIG. 1, and the evaluation results are shown in Table 2.

[0085]

[Table 2]

Example 2 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mol adduct 314
Parts, 314 parts of bisphenol A propylene oxide 2 mol adduct 274 parts of isophthalic acid and 20 parts of trimellitic anhydride were polycondensed, and 154 parts of isophorone diisocyanate were reacted to obtain a prepolymer (2). Next, 213 parts of the prepolymer (2), 9.5 parts of isophoronediamine and 0.5 part of dibutylamine were reacted in the same manner as in Example 1 to obtain a urea-modified polyester (2). 200 parts of the urea-modified polyester (2) and 800 parts of the unmodified polyester (b) were dissolved and mixed in 1000 parts of ethyl acetate to obtain a solution of the toner binder (2) in ethyl acetate. Partially dried under reduced pressure and toner binder (2)
Was isolated.

(Preparation of Toner) In the same manner as in Example 1, toner particles having spherical depressions were obtained. Then, 0.5 part of hydrophobic silica and 0.5 part of hydrophobic titanium oxide were mixed with 100 parts of the toner particles using a Henschel mixer to obtain the toner (1) of the present invention. Table 2 shows the evaluation results.

Example 3 (Preparation of Toner Binder) Unmodified polyester (a) with 30 parts of urea-modified polyester (1)
970 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain a solution of the toner binder (3) in ethyl acetate. A portion was dried under reduced pressure to isolate the toner binder (3). (Preparation of Toner) The procedure of Example 1 was repeated except that the toner binder (1) was changed to the toner binder (3). Other evaluation results are shown in Table 2.

Example 4 (Preparation of Toner Binder) 500 parts of urea-modified polyester (1) and 500 parts of unmodified polyester (a) were dissolved and mixed in 900 parts of ethyl acetate.
An ethyl acetate solution of the toner binder (4) was obtained. A part of the mixture was dried under reduced pressure to isolate the toner binder (4). (Preparation of toner) In a beaker, 210 parts of the above-mentioned toner binder (1) in ethyl acetate solution, and as a charge control agent,
Add 4 parts of copper phthalocyanine blue pigment and T
The mixture was stirred with a K-type homomixer at 12,000 rpm, and was uniformly dissolved and dispersed. Ion exchange water 265 in a beaker
, 260 parts of a 10% aqueous solution of tricalcium phosphate and 0.2 part of sodium dodecylbenzenesulfonate were added and uniformly dissolved. Then, the temperature was raised to 60 ° C., the mixture was stirred at 12,000 rpm with a TK homomixer, and 500 g of the suspension was transferred to a flask equipped with a thermometer capable of distillation, and stirred at 50 to 60 ° C.
The solvent was removed under reduced pressure at 50 ° C. for 50 to 60 minutes. Then, the resultant was filtered, washed, and dried, and then subjected to air classification to obtain toner particles having spherical depressions. Then, the toner particles 10
0.5 part of hydrophobic silica and 0 part of hydrophobic titanium oxide.
Two parts were mixed with a Henschel mixer to obtain a toner (1) of the present invention. Table 2 shows the evaluation results.

Example 5 (Preparation of toner binder) 100 parts of urea-modified polyester (1) and 900 parts of unmodified polyester (a) were dissolved and mixed in 1500 parts of ethyl acetate, and acetic acid of toner binder (5) was mixed. An ethyl solution was obtained.
A part of the mixture was dried under reduced pressure to isolate the toner binder (5). (Preparation of Toner) A spherical toner (5) having a depression was obtained in the same manner as in Example 4 except that the toner binder (1) was changed to the toner binder (5). Table 2 shows the evaluation results.

Example 6 (Preparation of toner binder) 100 parts of urea-modified polyester (1) and 900 parts of unmodified polyester (b) were dissolved and mixed in 1500 parts of ethyl acetate, and acetic acid of toner binder (6) was mixed. An ethyl solution was obtained.
A part of the resultant was dried under reduced pressure to isolate the toner binder (6). (Preparation of Toner) In the same manner as in Example 4 except that the toner binder (1) was changed to the toner binder (6), and 4 parts of a low molecular weight (MW 1500) of polyethylene WAX having a melting point of 108 ° C. was added as a release agent, the hollow was formed. Spherical toner (6) was obtained. As a result of examining the dispersion of the wax in the toner particles by TEM, wax-dispersed particles were confirmed in the particles. Other evaluation results are shown in Table 2.

Example 7 (Synthesis of Toner Binder) 924 parts of bisphenol A ethylene oxide 2 mol adduct, terephthalic acid 276
Part at 230 ° C. for 8 hours under normal pressure,
The reaction was carried out at a reduced pressure of 50 mmHg for 5 hours to obtain an unmodified polyester (c). 100 parts of urea-modified polyester (1) and unmodified polyester (c)
900 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain a solution of the toner binder (7) in ethyl acetate. A portion was dried under reduced pressure to isolate the toner binder (7). (Preparation of Toner) A spherical toner toner (7) having a depression was obtained in the same manner as in Example 6, except that the toner binder (1) was changed to the toner binder (7). Table 2 shows the evaluation results.

Example 8 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mol adduct 824 parts, terephthalic acid 276
Part was polycondensed at 210 ° C. under normal pressure for 10 hours.
The reaction was carried out at a reduced pressure of 20 mmHg for 5 hours, and the peak molecular weight was 5
000 unmodified polyesters (d) were obtained.
100 parts of urea-modified polyester (1) and 900 parts of unmodified polyester (d) were mixed with ethyl acetate / MEK.
(1/1) The mixture was dissolved and mixed in 2000 parts of a mixed solvent to obtain a solution of the toner binder (8) in ethyl acetate. A part of the mixture was dried under reduced pressure to isolate the toner binder (8). (Preparation of Toner) A spherical toner toner (8) having depressions was obtained in the same manner as in Example 6 except that the toner binder (1) was changed to the toner binder (8). Table 2 shows the evaluation results.

Example 9 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mole adduct 724 parts, terephthalic acid 276
Part under normal pressure at 230 ° C. for 8 hours,
After reacting at a reduced pressure of 15 mmHg for 5 hours, the mixture was cooled to 160 ° C., and 32 parts of trimellitic anhydride was added thereto and reacted for 2 hours to obtain an unmodified polyester (e) having a peak molecular weight of 5,000. 100 parts of urea-modified polyester (1) and unmodified polyester (e)
900 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of the toner binder (9). A part of the resultant was dried under reduced pressure to isolate the toner binder (9). (Preparation of Toner) A spherical toner toner (9) having depressions was obtained in the same manner as in Example 1 except that the toner binder (1) was changed to the toner binder (9). The average dispersion particle diameter of the pigment-based coloring material was 0.4 μm, and the number% of 0.7 μm or more was 3.5%. Table 2 shows the results.

Example 10 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mole adduct 724 parts, terephthalic acid 276
Part under normal pressure at 230 ° C. for 8 hours,
After reacting for 5 hours under a reduced pressure of 15 mmHg, the mixture was cooled to 160 ° C., and 48 parts of trimellitic anhydride was added thereto and reacted for 2 hours to obtain an unmodified polyester (f) having a peak molecular weight of 5,000. 100 parts of urea-modified polyester (1) and unmodified polyester (f)
900 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of the toner binder (10). A part of the resultant was dried under reduced pressure to isolate the toner binder (10). (Preparation of toner) Preparation of magenta masterbatch 1200 parts of water 600 parts Pigment Red 57 water-containing cake (50% solid content) is thoroughly stirred with a flasher. Here, polyester resin (acid value; 3, hydroxyl value; 25, Mn; 3500, Mw /
(Mn; 4.0, Tg; 60 ° C.)
After mixing and kneading, 1000 parts of xylene was added and kneading was further performed for 1 hour. After removing water and xylene, the mixture was rolled and cooled, pulverized with a pulperizer, and further passed through a three-roll mill for two passes to obtain a magenta master batch pigment.

(Preparation of Toner) The same procedure as in Example 1 was carried out except that the pigment-based coloring material and the toner binder (2) were changed to the toner binder (10), and the coloring material was changed to the above-mentioned 8 parts of the master master hatch. (10) was obtained. Table 2 shows the evaluation results.

Example 11 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mole addition product 724 parts, terephthalic acid 276
Part under normal pressure at 230 ° C. for 2 hours,
The reaction was carried out at a reduced pressure of 15 mmHg for 5 hours to obtain a peak molecular weight of 1
000 unmodified polyesters (g) were obtained.
100 parts of urea-modified polyester (1) and 900 parts of unmodified polyester (g) were mixed with ethyl acetate 2000
The mixture was dissolved and mixed to obtain a toner binder (11) in ethyl acetate. A part of the mixture was dried under reduced pressure to isolate the toner binder (11). (Preparation of Toner) A spherical toner (11) having a depression of the present invention was obtained in the same manner as in Example 1 except that the toner binder (1) was changed to the toner binder (11). Table 2 shows the evaluation results.

Example 12 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mole adduct 724 parts, terephthalic acid 276
Part under normal pressure at 210 ° C. for 6 hours,
The reaction was carried out at a reduced pressure of 15 mmHg for 5 hours to obtain an unmodified polyester (h). 100 parts of urea-modified polyester (1) and unmodified polyester (h)
900 parts were dissolved and mixed in 2000 parts of ethyl acetate to obtain an ethyl acetate solution of the toner binder (12). A part of the resultant was dried under reduced pressure to isolate the toner binder (12). (Preparation of Toner) A spherical toner (11) having a depression of the present invention was obtained in the same manner as in Example 1 except that the toner binder (1) was changed to the toner binder (12). Table 2 shows the evaluation results.

Example 13 (Preparation example of prepolymer) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 800 parts of a 2-mol adduct of bisphenol A ethylene oxide and 200 parts of isophthalic acid were added.
Parts, 50 parts of terephthalic acid, and 2 parts of dibutyltin oxide, and reacted at 230 ° C. for 8 hours under normal pressure, and further reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, and then cooled to 160 ° C. To this, 32 parts of phthalic anhydride was added and reacted for 2 hours. Then, the mixture is cooled to 80 ° C., and isophorone diisocyanate 17 in ethyl acetate.
The mixture was reacted with 0 parts for 2 hours to obtain an isocyanate group-containing prepolymer (3). (Production Example of Ketimine Compound) 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stirring rod and a thermometer, and reacted at 50 ° C. for 5 hours to obtain a ketimine compound (1).

(Production Example of Toner) 15.4 parts of the above-mentioned prepolymer (1) and polyester (a) 60 were placed in a beaker.
And 78.6 parts of ethyl acetate, and stirred to dissolve. Next, rice wax (melting point 83 ° C.) 10
And 4 parts of a copper phthalocyanine blue pigment, and the mixture was stirred at 60 ° C. with a TK homomixer at 12,000 rpm to uniformly dissolve and disperse. Finally, ketimine compound (1)
2.7 parts were added and dissolved. This is designated as a toner material solution (1). In a beaker, 306 parts of ion-exchanged water, 265 parts of a 10% tricalcium phosphate suspension, and 0.2 part of sodium dodecylbenzenesulfonate were put and uniformly dissolved. Then, the temperature was raised to 60 ° C. and 12000 with a TK homomixer.
While stirring at rpm, the above toner material solution (1) was charged and stirred for 10 minutes. Then, in the same manner as in Example 1, 500 g of the mixed solution was weighed and transferred to a kolben equipped with a stir bar and a thermometer. Separately, after washing and drying, the particles were classified by air to obtain spherical toner particles having the depression of the present invention. Then, 0.5 part of hydrophobic silica and 0.5 part of hydrophobic titanium oxide were mixed with 100 parts of the toner particles using a Henschel mixer to obtain a toner (13) of the present invention. At this time, the concentration of the emulsified dispersion was 16%.

Example 14 (Production example of prepolymer) In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introducing pipe, 856 parts of a 2-mol adduct of bisphenol A ethylene oxide and 216 parts of isophthalic acid were added.
Parts, 14 parts of terephthalic acid, and 2 parts of dibutyltin oxide, and reacted at 230 ° C. for 6 hours under normal pressure, further reacted for 5 hours while dehydrating at a reduced pressure of 50 to 100 mmHg, and then cooled to 160 ° C. To this, 32 parts of phthalic anhydride was added and reacted for 2 hours. Then, the mixture was cooled to 80 ° C., and isophorone diisocyanate 1 was added in ethyl acetate.
The mixture was reacted with 70 parts for 2 hours to obtain an isocyanate group-containing prepolymer (4) having a weight average molecular weight.

(Production Example of Ketimine Compound) 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stirring rod and a thermometer, and reacted at 50 ° C. for 5 hours to obtain a ketimine compound (1). (Production Example of Toner) In a beaker, 15.4 parts of the above-mentioned prepolymer (4), 50 parts of polyester (a) and 95.2 parts of ethyl acetate were put and dissolved by stirring. Next, 20 parts of carnauba wax (molecular weight: 1800, acid value: 2.5, needle penetration: 1.5 mm / 40 ° C.) and 3 parts of copper phthalocyanine blue pigment were added.
The mixture was stirred at 2000 rpm, and was uniformly dissolved and dispersed. Finally, 2.7 parts of ketimine compound (1) was added and dissolved. This is designated as a toner material solution (1). 465 parts of ion-exchanged water and 10% sodium carbonate suspension 245 in a beaker
And 0.4 part of sodium dodecylbenzenesulfonate were added and uniformly dissolved. Then, the temperature was raised to 60 ° C., and the above-mentioned toner material solution (1) was charged while stirring at 12,000 rpm with a TK homomixer, followed by stirring for 10 minutes. The mixture was then transferred to a kolben equipped with a stir bar and thermometer,
The temperature was raised to 60 ° C. in 2 hours, the solvent was removed in 50 to 60 minutes while the urea reaction was being performed, and the resultant was filtered, washed, dried, and then subjected to air classification to obtain toner particles. Next, 0.3 parts of hydrophobic silica and 0.3 parts of hydrophobic titanium oxide were mixed with 100 parts of the toner particles using a Henschel mixer to obtain spherical toner particles having depressions of the present invention (14). Was. At this time, the concentration of the emulsified dispersion was 13%. Table 2 shows the evaluation results.

Example 15 (Preparation example of prepolymer) In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introducing tube, 123 parts of a 2-mol adduct of bisphenol A ethylene oxide, 150 parts of isophthalic acid and 2 parts of dibutyltin oxide And 23 at normal pressure
The mixture was reacted at 0 ° C. for 8 hours, further reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, and then cooled to 160 ° C. to obtain a hydroxyl group-containing prepolymer (5). (Production Example of Dead Polymer) In the same manner as described above, 589 parts of a bisphenol A ethylene oxide 2 mol adduct and 464 parts of terephthalic acid dimethyl ester were polycondensed at 230 ° C. for 6 hours under normal pressure, and then 5 to 15 mmHg under reduced pressure.
After reacting for a time, a dead polymer (i) was obtained.

(Production Example of Toner) 15.3 parts of the above prepolymer (5) and dead polymer (i) 6 were placed in a beaker.
3.6 parts, 40 parts of toluene and 40 parts of ethyl acetate were added and dissolved by stirring. Next, low molecular weight polyethylene 1
0 parts (manufactured by Sanyo Chemical Co., Ltd., 171P) and 4 parts of copper phthalocyanine blue pigment were added.
The mixture was stirred at 000 rpm and uniformly dissolved and dispersed. Finally, 1.1 parts of diphenylmethane diisocyanate was added and dissolved as an extender. This is added to the toner material solution (1
5). In a beaker, 406 parts of ion-exchanged water, 294 parts of a 10% tricalcium phosphate suspension, and 0.2 part of sodium dodecylbenzenesulfonate were put and uniformly dissolved. Then, the temperature was raised to 60 ° C. and 12
While stirring at 000 rpm, the toner material solution (1
5) was added and stirred for 10 minutes. Then, 500 g of this mixed solution was transferred to a kolben equipped with a stir bar and a thermometer, and the temperature was raised to 50 ° C. in 30 minutes to allow the urethane reaction to proceed.
After removing the solvent in 60 minutes, filtering, washing, and drying, the resultant was classified by air classification to obtain spherical toner particles having dents of the present invention. (15) 0.3 parts of hydrophobic silica was added to 100 parts of the toner particles, 0.3 parts of hydrophobized titanium oxide was mixed with a Henschel mixer, and the concentration of the emulsified dispersion at this time was 11%. Table 2 shows the evaluation results.

Comparative Example 1 (Synthesis of Toner Binder) Bisphenol A ethylene oxide 2 mol adduct 395 parts and isophthalic acid 1
66 parts were polycondensed using 2 parts of dibutyltin oxide as a catalyst to obtain a comparative toner binder (Comparative 1). (Preparation of Toner) In a beaker, 100 parts of the comparative toner binder (Comparative 1), 180 parts of an ethyl acetate solution, 4 parts of copper phthalocyanine blue pigment, and a 10% solution of hydroxypropylapatite as a dispersant (Nippon Chemical Industry Co., Ltd. Tight 10) and sodium decylbenzenesulfonate were added, and the mixture was stirred at 50 ° C. with a TK homomixer at 10,000 rpm to be uniformly dissolved and dispersed. Next, a toner was formed in the same manner as in Example 1, but the solvent was removed slowly for 8 hours in the solvent removing step. 0.3 parts of hydrophobic silica and 0.3 parts of hydrophobic titanium oxide were mixed with 100 parts of the toner particles using a Henschel mixer. Table 2 shows the evaluation results.

Comparative Example 2 (Synthesis of Toner Binder) In a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introducing pipe, 343 parts of a 2-mol adduct of bisphenol A ethylene oxide and 166 parts of isophthalic acid were added.
Parts and 2 parts of dibutyltin oxide, and
After reacting at 30 ° C. for 8 hours and further reacting under reduced pressure of 10 to 15 mmHg for 5 hours, the mixture was cooled to 80 ° C., 14 parts of toluene diisocyanate was added in toluene, and the reaction was carried out at 110 ° C. for 5 hours. To obtain a urethane-modified polyester. 363 parts of bisphenol A ethylene oxide 2 mol adduct and 166 parts of isophthalic acid were polycondensed in the same manner as in Example 1 to obtain an unmodified polyester. 350 parts of the urethane-modified polyester and 650 parts of the unmodified polyester were dissolved and mixed in toluene, and then the solvent was removed to obtain a comparative toner binder (Comparative 2). (Preparation of toner) Comparative toner binder (2) 100
Part, chromium salicylate complex (E-81 manufactured by Orient Chemical Co.) as charge control agent, 2 parts, copper phthalocyanine blue pigment 4
A part was formed into a toner by the following method. First, the mixture was preliminarily mixed using a Henschel mixer, and then kneaded with a continuous kneader. Then, after finely pulverizing with a jet pulverizer, the mixture was classified with an airflow classifier. 0.3 parts of hydrophobic silica and 0.3 parts of hydrophobic titanium oxide were mixed with 100 parts of the toner particles using a Henschel mixer. Table 2 shows the evaluation results.

Comparative Example 3 Polyester resin (bisphenol-based resin, manufactured by Kao Corporation) 90 parts (Mn = 6000, Mw = 70000, Tg = 64 ° C.) Carbon black (BP1300, manufactured by Cabot Corporation) 10 parts Rice wax (melting point: 82 ° C.) 10 parts Diethyl ether / dichloromethane mixed solution (50:50) 300 g The above components were mixed and dispersed by a ball mill for 10 hours. The obtained dispersion is added to a 2% aqueous solution of gum arabic 4
Then, the mixture was dispersed for 3 minutes by a homomixer. Thereafter, the mixture was put into 2000 g of pure water, kept at 80 ° C. in a water bath, and kept for 4 hours while stirring with a three-one motor. Thereby, irregularly shaped irregular particles having concave portions having an average particle diameter of 6.0 μm were obtained. The temperature of the suspension in this state is raised to 98 ° C., and maintained at that temperature for one hour, and the suspension is spheroidized with almost the same particle diameter, to obtain particles which are spherical but have partially unevenness on the surface. Was.

[Evaluation Method] Tg Measurement Method The measurement method of Tg will be outlined. As an apparatus for measuring Tg, TG-DSC system TAS-1 manufactured by Rigaku Denki Co., Ltd.
00 was used. First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit, and set in an electric furnace. First, the temperature is increased from room temperature at a rate of 10 ° C./min.
After heating to 50 ° C, leave at 150 ° C for 10 minutes,
The sample was cooled to room temperature, left standing for 10 minutes, and heated again at 150 ° C. in a nitrogen atmosphere at a rate of 10 ° C./min for DSC measurement. Tg was calculated from the contact point between the tangent line of the endothermic curve near Tg and the baseline using the analysis system in the TAS-100 system.

Acid value and hydroxyl value According to the method specified in JIS K0070. However, if the sample does not dissolve, use dioxane or tetrahydrofuran as the solvent. Particle Size Distribution Measurement Apparatus for measuring the particle size distribution of toner particles by the Coulter counter method includes Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter Corporation). The measurement method is described below. First, 0.1 to 5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolyte is prepared by preparing an approximately 1% NaCl aqueous solution using primary sodium chloride, and for example, ISOTON-II (manufactured by Coulter Inc.) can be used. Here, the measurement sample is further 2 to 20 m
Add g. The electrolyte solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of toner particles or toner were measured by using the measuring device with a 100 μm aperture as an aperture. Calculate volume distribution and number distribution. From the obtained distribution, the weight average particle diameter (D4) and the number average particle diameter of the toner can be obtained.

The channels are 2.00 to 2.52
less than 2.5 μm; less than 2.52 to 3.17 μm;
4. less than 4.00 μm; 4.00 to less than 5.04 μm;
04 to less than 6.35 μm; 6.35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to 1
2.70 μm or less; 12.70 to less than 16.00 μm;
16.00 to less than 20.20 μm; 20.20 to 25.
Less than 40 μm; 25.40 to less than 32.00 μm; 3
Thirteen channels of 2.00 to less than 40.30 μm are used, and particles having a particle size of 2.00 μm or more to less than 40.30 μm are targeted.

Powder Fluidity The bulk density was measured using a powder tester manufactured by Hosokawa Micron. The higher the fluidity of the toner, the greater the bulk density. The following four grades evaluated. ×: less than 0.25 Δ: 0.25 to less than 0.30 ：: 0.30 to less than 0.35 ：: 0.35 or more Heat storage stability After storing the toner at 50 ° C. for 8 hours, it was passed through a 42 mesh sieve. For 2 minutes, and the residual ratio on the wire mesh was regarded as the heat-resistant storage stability. The residual ratio of toner having better heat-resistant storage stability is smaller. The following four grades evaluated. ×: 30% or more △: less than 20 to 30% ：: less than 10 to 20% ：: less than 10%

Fixing Lower Limit Temperature A fixing device of a copying machine MF-200 manufactured by Ricoh Co., Ltd. using a Teflon (registered trademark) roller as a fixing roller was used.
No paper was set and a copy test was performed. The fixing roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad was 70% or more was defined as the fixing lower limit temperature. Hot Offset Occurrence Temperature (HOT) The fixing was evaluated in the same manner as the fixing lower limit temperature, and the presence or absence of hot offset to the fixed image was visually evaluated. The fixing roll temperature at which hot offset occurred was taken as the hot offset occurrence temperature.

Gloss Development Temperature (GLOSS) Fixing was evaluated using a fixing device of a commercially available color copying machine (PRETER 550; manufactured by Ricoh). The gloss development temperature was defined as the fixing roll temperature at which the 60 ° gloss of the fixed image became 10% or more.

[0114] Haze degree The above monochromatic image sample was used as transfer paper by Ricoh OH
Fixing belt using P sheet (type PPC-DX)
The haze of the sample when the surface temperature is
Computer Haze Degree Computer H
It was measured by GM-2DP type. This haze is cloudy
It is also measured as a measure of toner transparency.
The lower the value, the higher the transparency, and an OHP sheet was used.
In this case, the coloring property is good. Good color development
Is preferably 30% or less, particularly 2%.
The case where it is 0% or less is preferable.

Charge Stability The amount of charge at low temperature, low humidity, and high temperature and high humidity is measured by the blow method, and the fluctuation range is evaluated. It is necessary to use a silicone resin-coated iron powder for the carrier and measure the environment under the conditions of 30 ° C 90% and 10 ° C 30%. ×: Not usable △: Large difference ○: Difference is slightly large ◎: Small difference and stable Examples 1 to 15 and Comparative Examples 1.2 and 3 are manufactured by Ricoh
Image output evaluation and transferability evaluation were performed using imagio Color4000. The results are shown in Table 3.

[0116]

[Table 3]

The toner Examples 1 to 15 of the present invention and Comparative Examples 1, 2, and 3 were subjected to a continuous image copy test of 30,000 sheets in an image apparatus equipped with a brush cleaning device shown in FIG. The resulting toner showed improved results in transfer rate and brush cleaning as compared to the comparative toner. Further, compared to the comparative toner, toner scattering in the transfer process was small, dot reproducibility was secured, and a stable image could be obtained even when used for a long time. This is presumably because the chargeability of the toner was more stable due to the spherical concave shape. In Comparative Examples 1 to 3, the toner was scattered in the transfer process, and high image quality could not be obtained. Table 3 shows the results.

[0118]

The dry toner of the present invention has the following effects. 1. A powder dry toner excellent in transferability and cleaning performance is provided by a spherical shape having a toner dent.

[0119] 2. A dry toner which achieves oillessness and has excellent low-temperature fixability and hot offset resistance is provided. 3. Excellent gloss when used as color toner and OH
A dry toner excellent in P transparency is provided.

[0120] 4. A method for producing a dry toner having a small particle size and a sharp particle size distribution is provided. 5. An image forming method for obtaining a high quality image in an image forming apparatus using an intermediate transfer member is provided. 6. A highly durable image forming method without cleaning residual toner in a cleaning device provided with a cleaning blade is provided.

[Brief description of the drawings]

FIG. 1 is a graph showing a molecular weight distribution of a toner.

FIG. 2 is an electron micrograph of a toner having a depression.

FIG. 3 is a particle collection electron micrograph having a depression.

FIG. 4 is a sectional view showing a main part of a brush cleaning device applied to an embodiment of the present invention.

FIG. 5 is a configuration diagram of an example of an image forming apparatus applied to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoreceptor 2 Charger 3 Exposure means 4 Developing device 5 Transfer / transport device 6 Cleaning device 7 Paper feeding means 9 Static elimination lamp 41 First developing roller 42 Second developing roller 43 Paddle-shaped stirring member 44 Stirring member 45 Doctor 46 Toner supply unit 47 Supply roller, 61 Cleaning blade 62 Cleaning brush roller 81, 82 Guide rail

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Yamashita 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tsuneshin Suginama 1-3-6 Nakamagome, Ota-ku, Tokyo Share Inside Ricoh Company (72) Inventor Kazuto Watanabe 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Masami Tomita 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company F term (reference) 2H005 AA01 AA15 AB03 CA08 CA17 CA18 EA03 EA05 EA06 EA10

Claims (27)

[Claims] 1. A dry toner containing at least a resin and a colorant, wherein the circularity of the toner is 0.960 to 1.60.
000 and a plurality of depressions on the surface. 2. A dry toner having a circularity of from 0.980 to 0.980.
2. The dry toner according to claim 1, wherein the ratio is 1.000. 3. The method according to claim 1, wherein the plurality of depressions on the surface have a major axis of the surface depression measured on an image (SEM image) taken with a scanning electron microscope of 1.0 to 5.0 μm. The dry toner according to claim 1. 4. The toner according to claim 1, wherein the toner has an average particle diameter of 4 to 9 μm.
The dry toner according to any one of claims 1 to 3, wherein m is m. 5. The dry toner according to claim 1, wherein a resin having at least the highest composition in the dry toner is a polyester resin. 6. The molecular weight distribution of the above-mentioned polyester resin in the THF-soluble component is such that the peak of the molecular weight is 1,000 to 30,000,
0000 or more components are 1% or more and number average molecular weight is 200
The dry toner according to claim 5, wherein the number is from 0 to 15,000. 7. In the molecular weight distribution of the THF-soluble component of the polyester resin, a component having a molecular weight of 1,000 or less is 0.1 to 0.1.
6. The dry toner according to claim 5, wherein the content is 5.0%. 8. The dry toner according to claim 5, wherein the polyester resin has a THF-insoluble content of 1 to 10%. 9. The dry toner according to claim 5, wherein the polyester resin has a glass transition point of 55 to 75 ° C. and an acid value of 1 to 30 mgKOH / g. 10. The dry toner according to claim 5, wherein the polyester resin is a modified polyester. 11. The dry toner according to claim 10, wherein the modified polyester resin has a Urea bond. 12. The dry toner according to any one of claims 5 to 11, wherein the polyester resin contains a polyester resin in which the polyester resin is not modified. 13. The polyester resin according to claim 1, comprising a modified polyester resin and an unmodified polyester resin, wherein a ratio of the modified polyester resin to the unmodified polyester resin is 5/95 to 80/20. The dry toner according to any one of claims 5 to 12, wherein 14. The dry toner according to claim 5, further comprising at least an alkylene oxide adduct of a bisphenol as a polyol component of the polyester resin. 15. The toner according to claim 1, wherein the dispersed particle diameter of the colorant in the toner is 0.5 μm or less in number average diameter, and the number ratio of particles having a particle diameter of 0.7 μm or more is 5% by number or less. The dry toner according to claim 10, wherein 16. The toner according to claim 1, wherein the dispersed particle diameter of the colorant in the toner is 0.3 μm or less in number average, and the number ratio of the particles having a number average of 0.5 μm or more is 10 or less. 16. The dry toner according to any one of 1 to 15. 17. The dry toner according to claim 1, wherein the dry toner contains a wax as a release material. 18. The dry toner according to claim 1, wherein the dry toner contains a charge control agent. 19. A toner composition comprising at least a resin and a colorant is dissolved or dispersed in an organic solvent, and the solution or dispersion is dispersed in an aqueous medium in the presence of an inorganic dispersant or a fine particle polymer. The dry toner according to any one of claims 1 to 18, wherein the toner is obtained by removing a solvent of an emulsified dispersion obtained by subjecting a substance or a dispersion to a polyaddition reaction. 20. The dry toner according to claim 19, wherein the solid content of the emulsified dispersion is 10 to 50% in the dry toner. 21. An isocyanate group-containing prepolymer dispersed in an aqueous medium in the presence of an inorganic dispersant or a fine particle polymer by dispersing a toner composition comprising a polyester resin in the aqueous medium. An elongation reaction and a cross-linking reaction are carried out, and the solvent is removed from the obtained emulsified dispersion to obtain the emulsion dispersion.
Or the dry toner according to item 20. 22. The dry toner according to claim 21, wherein a solid content of the emulsified dispersion is 10 to 50% in the dry toner. 23. The dry toner according to claim 1, wherein the toner is a two-component toner. 24. An image forming apparatus using the dry toner according to claim 1. 25. The image forming apparatus according to claim 24, wherein said image forming apparatus is an apparatus for forming a multicolor image. 26. The image forming apparatus according to claim 24, wherein the image forming apparatus has an endless intermediate transfer unit. 27. The image forming apparatus according to claim 24, wherein said image forming apparatus has a blade cleaning unit.