JP5655417B2 - Toner, process cartridge, image forming method, and toner manufacturing method - Google Patents

Description

  The present invention relates to a toner used in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, a process cartridge including a developing unit containing the toner, and a method for manufacturing the toner.

  In recent years, in the field of electrophotographic image forming technology, competition for development of a color image forming apparatus (high quality color image forming technology) capable of high-speed image formation and high image quality is intensifying. For this reason, in order to obtain a full-color image at a high speed, a plurality of electrophotographic photosensitive members are arranged in series in the image forming method, and an image for each color component is formed on each electrophotographic photosensitive member, and is superimposed on the intermediate transfer member. Many so-called tandem systems that perform batch transfer onto a recording material have been employed (see, for example, Patent Document 1 and Patent Document 2).

  When an intermediate transfer member is used, there is an effect of preventing the background stain from being transferred directly to a recording material such as paper when the background stain occurs on the electrophotographic photosensitive member during development. Transfer efficiency is reduced due to the two transfer processes: the transfer process (primary transfer) from the photoconductor to the intermediate transfer body and the transfer process (secondary transfer) onto the recording material for obtaining the final image from the intermediate transfer body. To do.

  On the other hand, in addition to the above problems, there is a demand for higher-quality full-color image formation, and developers have been designed for higher image quality. In order to meet the demands for higher image quality, especially full-color image quality, toners are becoming increasingly smaller in particle size and are being studied to faithfully reproduce the electrostatic latent image formed on the photoreceptor. . In order to reduce the particle size, a toner manufacturing method using a polymerization method has been proposed as a means for controlling the toner to a desired toner shape and surface structure (for example, Patent Document 3 and Patent Document 3). 4).

  In the case of the polymerization toner, in addition to controlling the particle size of the toner particles, shape control is possible. In addition, by reducing the particle size together with this, the reproducibility of dots and fine lines can be improved, the pile height (image layer thickness) can be lowered, and higher image quality can be expected. However, when a small particle size toner is used, the non-electrostatic adhesion force between the toner particles and the electrophotographic photosensitive member or between the toner particles and the intermediate transfer member is increased, so that the transfer efficiency is likely to further decrease. For this reason, when a small-diameter toner is used in a high-speed full-color image forming apparatus, the transfer efficiency is particularly lowered in the secondary transfer. The reason for this is that non-electrostatic adhesion to the intermediate transfer member per toner particle is increasing due to the reduction in the toner particle size, and in the secondary transfer, it exists in a state where a plurality of color toners are superimposed. This is because the time during which the toner particles are subjected to the transfer electric field at the nip portion of the secondary transfer is shortened as the speed is increased, and the transfer is more difficult.

  In order to address the above problems, it is conceivable to further increase the transfer electric field of the secondary transfer. However, if the transfer electric field is excessively increased, the transfer may be caused by the occurrence of discharge when the intermediate transfer member and the recording material are peeled off. There is a limit as efficiency decreases. In addition, it is conceivable to increase the time during which the toner particles are subjected to the transfer electric field by increasing the width of the nip portion of the secondary transfer. The only way to achieve this is to either increase the contact pressure of the bias roller or increase the roller diameter of the bias roller. Increasing the contact pressure has a limit due to the relationship with the image quality, and increasing the roller diameter has a limit due to the relationship with the downsizing of the apparatus. Further, in the case of a non-contact voltage application method using a charger or the like as a transfer electric field, there is a limit because the nip width of secondary transfer must be increased by increasing the number of chargers. For this reason, it can be said that it is practically impossible to increase the nip width until a transfer efficiency higher than this is obtained, particularly in a high-speed machine.

  In contrast, as a means for reducing the non-electrostatic adhesion between the toner particles and the electrophotographic photosensitive member, or between the toner particles and the intermediate transfer member, the type and amount of the additive are adjusted (especially addition with a large particle size). A method of adding an agent has been proposed (see, for example, Patent Document 5 and Patent Document 6). By this method, the toner particles can obtain the effect of reducing the non-electrostatic adhesion force and improve the transfer efficiency, and also can obtain the effects of improving the development stability and cleaning.

  Initially, the toner particles described above can improve the transfer efficiency of the image forming apparatus. However, when the toner has been subjected to mechanical stress such as stirring for a long time in the developing device of the image forming apparatus, the additive is buried in the toner base particles or enters the minute unevenness present on the toner particle surface. As a result, the effect of reducing the adhesive force by the additive is not exhibited, and the transfer efficiency of the image forming apparatus is lowered. Particularly in the case of a high-speed machine, since the stirring in the developing device is intense, this mechanical stress is large, and the embedding and penetration of the additive into the toner base are likely to be accelerated. For this reason, it is assumed that transfer efficiency is lowered at a relatively early stage. For this reason, in order to maintain high transfer efficiency stably over a long period of time on a high-speed machine, the toner can be present on the surface without being embedded or invading into the toner base particles even under mechanical stress. It is necessary to control the surface property.

  Furthermore, an electrophotographic image forming method has been applied to the field of high-speed printing with a large image area such as offset printing. At this time, as one of the problems of the electrophotographic method, the point is to fix the toner image on the recording material with low energy. On the other hand, it is important for the toner used for image formation to lower the fixing temperature of the toner itself and to prevent hot offset on the high temperature side. Therefore, a proposal has been made to lower the fixing temperature by using a polyester resin that is advantageous for low-temperature fixing (see, for example, Patent Document 7). In addition, as a method for preventing the hot offset property, a method for controlling the viscoelasticity of the toner by introducing it into the toner by using a polymer binder resin, or by using a releasing agent such as wax. It is well known to suppress it by improving the releasability from the fixing member. For example, with respect to the use of a mold release agent, as described in Patent Document 7, paraffin wax is used and a range of melting point by the DSC method has been proposed. An effect on releasability is recognized. Here, as described above, in the high-speed printing field, even when a large amount of printing is performed with a large image area, high image quality that is the same as the initial value is required. On the other hand, with the waxes proposed previously, when used in an electrophotographic image forming apparatus for printing in large quantities, paraffinic wax with high volatility causes contamination or transfer to various image forming apparatus members. It has been found that problems such as contamination of the medium itself occur.

  For example, Patent Document 8 shows an improvement effect by prescribing a heat loss at 220 ° C. for storage stability, carrier spent, and photoconductor filming, but does not satisfy the heat loss at this temperature. However, in the case of a toner production method using wax type or water-based granulation, the above-mentioned problems may not occur. Rather, even when the above heat loss characteristics are satisfied, the member contamination is insufficient in high-speed printing, and further, the separation property of the recording material during high-speed printing is insufficient. Further, when a high melting point paraffin wax is simply used, it is difficult to obtain desired release properties, and image quality is deteriorated such as occurrence of hot offset and reduction in gloss. In fact, simply specifying the melting point of the paraffin wax does not ensure the contamination in the image forming apparatus and the desired fixing property. Also, images for high-speed printing are mostly full-color images with a high image area ratio, and it is necessary to separate the heating medium and the transfer medium at high speed reliably in the fixing process. Ensuring moldability and in-flight contamination are the most important issues.

  In addition, it has been proposed to use microcrystalline wax to solve image unevenness during fixing and to improve image quality (see, for example, Patent Document 9). In Patent Document 9, the endothermic peak of the wax and the half-value width of the endothermic peak are further defined for the purpose of solving the image unevenness. As a result, image unevenness can be solved, but the melting point of the wax is high, which is disadvantageous for low-temperature fixability. In addition, considering the low-temperature fixability, simply lowering the endothermic peak of the wax leaves a problem in the separation property between the paper as the recording material at high temperature and the roller of the fixing device.

  The present invention has been made in consideration of the above circumstances, has excellent releasability during low-temperature fixing, has little filming, has both low-temperature fixability and heat-resistant storage stability, and further volatilizes during fixing. An object of the present invention is to provide a toner capable of achieving both minute reduction, low-temperature fixability and paper-roller separation during high-temperature fixing, a process cartridge including a developing unit containing the toner, and a method for producing the toner. To do.

The present invention for solving the above problems is specifically as follows.
(1): In a toner containing at least a binder, a colorant, and a microcrystalline wax that constitutes a molecular chain only by C—H bonds and C—C bonds, the mass reduction of the wax at 165 ° C. is 10% by mass. The ratio of the total amount of wax in the toner particles measured by the DSC method in the toner is 1.3 mass% to 3.7 mass% , and the BET specific surface area (Sbet) of the toner and the toner The toner is characterized in that the average circularity (SF) ratio Sbet / SF of the toner is in the range of 1.0 m ² / g or more and less than 3.6 m ² / g.
(2): The toner according to (1), wherein the wax has a melting point of 50 to 90 ° C.
(3): The toner according to (1) or (2) above, wherein the wax in the toner has a melt viscosity at 140 ° C. of 6 to 15 mPa · S.
(4): The toner according to any one of (1) to (3) above, wherein the weight loss of the wax at 165 ° C. is 3% by mass or less.
(5): The toner according to any one of (1) to (4), wherein the toner contains 40% by mass to 80% by mass of a wax dispersant with respect to the wax. Toner.
(6): In the toner according to any one of (1) to (5), the material constituting the toner contains a binder resin or a precursor of the binder resin as a binder component. The toner is characterized by that.
(7): In the toner according to (6), the binder resin precursor is an active hydrogen group-containing compound and a polymer having reactivity to the active hydrogen group, and an aqueous medium containing a surfactant. A toner comprising a reaction product obtained by reacting the active hydrogen group-containing compound with a polymer having reactivity with the active hydrogen group in the emulsifying or dispersing step.
(8): In the toner according to (6) or (7), the material constituting the toner includes a polyester resin as the binder resin.
(9): In a process cartridge that at least integrally supports the electrostatic latent image carrier and the developing unit and is detachable from the image forming apparatus main body, the developing unit includes the electrostatic latent image carrier. It contains toner that supplies an electrostatic latent image to form a toner image of the electrostatic latent image, and the toner is the toner described in any one of (1) to (8) above. This is a featured process cartridge.
(10) The toner production method according to any one of (1) to (8) above, wherein the molecular chain includes at least a binder, a colorant, and a C—H bond and a C—C bond. In the surface treatment step of heating the toner dispersion obtained by the step after the step of emulsifying or dispersing the toner material liquid comprising the liquid containing the microcrystalline wax constituting the toner in an aqueous medium containing a surfactant. A method for producing a toner, wherein the temperature (T1) of the toner dispersion is in the range of 45 ° C to 90 ° C.
(11): The method for producing a toner according to (10) above, wherein the time during which the temperature of the toner dispersion liquid temperature (T1) in the surface treatment step is in a range of 45 ° C. to 90 ° C. is 1 It is a method for producing a toner, characterized in that it is not shorter than 1 minute and not longer than 1 hour.
(12): The method for producing a toner according to (10) or (11), wherein the amount of the surfactant in the surface treatment step is 0.1 times or more the critical micelle concentration of the surfactant. The toner production method is characterized by being less than 0 times.

According to the present invention, the toner material liquid contains at least a binder, a colorant, and a wax that constitutes a molecular chain with only C—H bonds and C—C bonds, and in the toner by the DSC method. The ratio of the total amount of wax in the measured toner particles is 1% by mass to 8% by mass, and the ratio Sbet / SF between the BET specific surface area (Sbet) of the toner and the average circularity (SF) of the toner is 1. By being in the range of 0 m ² / g or more and less than 3.6 m ² / g, excellent releasability at low temperature fixing, less filming, and compatibility between low temperature fixability and heat resistant storage stability, Further, a toner capable of reducing both volatile content at the time of fixing, low temperature fixability and separation of paper and roller at high temperature fixing, a process cartridge including a developing unit containing the toner, and a method for manufacturing the toner Can be provided.

3 is a cross-sectional TEM photograph of the toner of the present invention. 1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. It is a figure which shows schematic structure of the image formation means of FIG. It is a figure which shows schematic structure of the process cartridge which concerns on one Embodiment by this invention. 1 is a diagram illustrating a schematic configuration of a fixing device of an image forming apparatus used in an embodiment of the present invention.

The toner according to the present invention is a toner containing at least a binder, a colorant, and a microcrystalline wax having a molecular chain composed only of C—H bonds and C—C bonds. The ratio of the total amount of wax in the toner particles measured by the DSC method in the toner is 1.3% by mass to 3.7% by mass , and the BET specific surface area (Sbet) of the toner And the average circularity (SF) ratio Sbet / SF of the toner is in the range of 1.0 m ² / g or more and less than 3.6 m ² / g.
Further, in the above preparative toner production method of the present invention, the toner material solution (at least a binder, a colorant, and a liquid containing a microcrystalline wax constituting the molecular chain only in C-H bonds and C-C bond And a surface treatment step of heating, in which the toner dispersion temperature (T1) in the surface treatment step is in the range of 40 ° C. to 95 ° C. Therefore, it can be easily manufactured. In this case, the toner dispersion temperature (T1) is more preferably 45 ° C. to 80 ° C. Then, it is preferable to perform the surface treatment while maintaining the toner dispersion temperature (T1) within 1 minute or more within 1 hour.

  In the present invention, the “toner base” is assumed to be a particle after the surface treatment is finished and before the external addition treatment, and a particle that has not been subjected to the previous surface treatment may be called a “colored particle”.

  The present inventors have already developed an O / W type obtained by emulsifying and dispersing an organic solvent liquid containing a toner material such as a low-molecular-weight binder resin component having a crosslinking reactivity and a colorant in an aqueous dispersion. A number of toner manufacturing techniques have been proposed which include the removal of solvent from the dispersion to obtain toner base particles. Among these techniques, many use aqueous dispersions in which fine inorganic and / or resin fine particles are dispersed as aqueous dispersions, and the aging process of toner base particles, regardless of the order. (Surface treatment process), some toner manufacturing techniques including a washing process for washing the toner base particles to remove the surfactant derived from the O / W emulsion dispersion, and a surfactant treatment process for the toner base particles. Or included. In the process of further studying these, the inventors controlled the amount of surfactant added during aging to a smaller range, and when aging was performed, the formation of minute irregularities was adjusted, and the surface smoothing was excellent. And the fact that such a result is applicable to other chemical toner manufacturing techniques, and is also applicable to toner manufacturing using pulverized toner. The toner of the present invention has been completed through further studies based on the above.

  The toner obtained by the above production method is preferably heated in water containing a small amount of a surfactant at a temperature close to the glass transition temperature of the toner, whereby the binder resin component contained in the colored particles for toner Softens and flows in a very small region so as to reduce the surface area, so that the minute unevenness of several nm to several hundred nm existing on the surface of the toner base particles can be relaxed and smoothed. However, simply heating the toner may worsen contamination of other members of the toner, particularly the carrier. The reason is not clear, but the resin component of the toner is weakened and softened by heating, but at this time, the low molecular weight component of the resin is exposed to the toner surface, and it is estimated that contamination to other members, particularly the carrier, deteriorates. . As a result, it is possible to reduce the contamination of the toner on other members by applying shearing during heating as well as simply heating. Furthermore, it is also preferable in that shearing during heating can prevent toner aggregation due to heating. It is preferable that the shear during heating can be processed continuously from the viewpoint of manufacturability. For example, a pipeline homomixer (manufactured by Primics) and Ebara Milder (manufactured by Aihara Seisakusho) are preferred.

  Normally, when the toner in the developing means is subjected to mechanical stress, the external additive penetrates into the minute irregularities on the surface of the toner particles, thereby increasing the non-electrostatic adhesion and improving the transfer efficiency. descend. In particular, when a toner having a small particle diameter is used, the non-electrostatic adhesion force between the toner particles and the electrophotographic photosensitive member or between the toner particles and the intermediate transfer member is increased, so that the transfer efficiency is further lowered. Furthermore, when a small particle size toner is used in a high-speed machine, non-electrostatic adhesion to the intermediate transfer member is increased by reducing the particle size of the toner, and the transfer nip portion, It is known that in the secondary transfer nip portion, the time during which the toner particles are subjected to the transfer electric field is shortened, so that the transfer efficiency in the secondary transfer is significantly reduced.

  As a heating method, it is preferable to add a cake adjusted to a water content of 50% by mass to 85% by mass to ion-exchanged water adjusted to 50 ° C. to 98 ° C. by filtering colored particles dispersed in water. . Thereby, the temperature can be adjusted to the target temperature in a short time, fine irregularities of the colored particles can be eliminated in a short time, and exposure of wax and the like contained in the colored particles can be suppressed, which is more preferable.

  In the toner obtained by the production method of the present invention, since the fine irregularities on the surface of the toner particles are alleviated by the surface treatment process, the function deterioration due to the penetration of the external additive into the irregularities of the toner particles as described above is prevented. Even when the toner is subjected to mechanical stress, an increase in non-electrostatic adhesion can be suppressed and high transfer efficiency can be obtained. In addition, since the minute unevenness on the toner surface is alleviated, the surface area of the toner per unit weight becomes smaller than that of the toner surface where the minute unevenness exists. The effective coverage of the additive is increased. As a result, the effect of reducing the non-electrostatic adhesion force by the external additive is increased, so that even when the toner is subjected to mechanical stress, an increase in the non-electrostatic adhesion force can be suppressed and high transfer efficiency can be obtained. .

In the present invention, the heat treatment is carried out in water. However, when it is carried out in the gas phase, the toner particles tend to be fused even at the same temperature as in water, and the toner particle size distribution may be deteriorated. Further, when the same treatment is performed in the gas phase, a higher heating temperature is required, and the toner particles are further fused. Therefore, surface treatment by heat treatment in water is preferable. In this case, when the concentration of the surfactant added to the water is higher than twice the critical micelle concentration, the surfactant protects the minute irregularities on the toner surface when heated, and thus the toner surface is smooth. Therefore, high transfer efficiency cannot be obtained. On the contrary, when the surfactant concentration is less than 0.1 times the critical micelle concentration, not only the unevenness of several nm to several hundred nm on the toner surface but also the unevenness of about several μm is relaxed. The cleaning property is deteriorated. On the other hand, when the concentration is less than 0.1 times the critical micelle concentration, the toner particles are likely to be fused with each other by heating in the surface treatment process, and the particle size distribution of the toner may be deteriorated.
That is, in the present invention, the surfactant in the surface treatment step is preferably 0.1 times or more and less than 2.0 times the critical micelle concentration of the surfactant.

  When the toner dispersion temperature (T1) in the surface treatment step is less than 45 ° C., the binder resin in the toner is not softened, so that the toner surface is not smoothed and high transfer efficiency cannot be obtained. In addition, when the toner dispersion temperature (T1) is 90 ° C. or higher, toner particles are fused by the softening of the toner resin at the low surfactant concentration as in the present invention. Will worsen.

  The toner according to the present invention is obtained by adjusting a toner material containing at least a binder resin, a wax, and a colorant in an aqueous medium containing a surfactant, and further removing the surfactant. It is preferable to contain. In the case of a toner obtained in an aqueous medium, since the toner material has an affinity with water as a dispersion solvent, the toner surface can be more easily smoothed by heating. In addition, since the manufacturing process includes a state where the toner is dispersed in the aqueous medium and includes a step of removing the surfactant, an increase in the manufacturing process accompanying the surface treatment step can be suppressed.

  Moreover, it is preferable that the binder resin used for this invention contains a polyester resin. Polyester resin is superior in impact resistance compared to other resins even when a low softening point is used to improve low-temperature fixability, so it can improve the stress resistance of the toner, and in the molecular structure. Since it has a hydrophilic group and has a relatively high polarity, it has an excellent affinity with an aqueous medium, and it is easier to achieve surface smoothing.

In addition, the toner obtained by the above production method has a ratio Sbet / SF of 1.0 m ² / g or more and less than 3.6 m ² / g between the BET specific surface area (Sbet) of the toner and the average circularity (SF) of the toner. It is desirable to be 1.2 m ² / g or more and less than 3.1 m ² / g.

  The purpose of the present invention is to improve the desired quality by smoothing the toner surface. Although the cause is not clear, the desired quality can be achieved by setting the ratio of the values measured by smoothing the toner details with the BET specific surface area and the smoothing of the entire toner particles with the circularity within the above range. I found out.

  The toner obtained by the production method of the present invention preferably has an average circularity of 0.940 or more and less than 0.975. When it is 0.975 or more, the shape of the toner particles is close to a true sphere, and the cleaning ability of the transfer residual toner on the photosensitive member and the intermediate transfer member may be inferior. If it is less than 0.940, since there are many relatively large irregularities of about several hundred nm on the toner surface, high transfer efficiency can be achieved even if minute irregularities of several nm to several hundred nm are alleviated in the present invention. It may not be obtained.

  The particle diameter of the toner obtained by the production method of the present invention is controlled so that the volume average particle diameter is 1 μm to 8 μm. In particular, the toner preferably has a volume average particle diameter of 2 μm to 7 μm. If it is smaller than 1 μm, toner dust is likely to occur in the primary transfer and secondary transfer. Conversely, if it is larger than 8 μm, the dot reproducibility becomes insufficient and the graininess of the halftone part also deteriorates. A high-definition image cannot be obtained.

(Critical micelle concentration)
The critical micelle concentration of the surfactant with respect to the aqueous medium can be determined by a surface tension method, an electric conductivity method, a dye method, or the like. For example, measurement can be performed using a surface tension meter Sigma (manufactured by KSV Instruments), and analysis can be performed using an analysis program in the Sigma system. Surfactant was dropped 0.01% by mass with respect to the aqueous medium, and the interfacial tension after stirring and standing was measured. From the obtained surface tension curve, the surfactant concentration at which the interfacial tension did not decrease even when the surfactant was dropped was calculated as the critical micelle concentration.

(Shearing method)
As the shearing device, a high-speed shear mixer is preferable. As the high-speed shear mixer, homogenizer Polytron (Central Science Trade Co., Ltd.), homogenizer Histron (Nissan Medical Science Equipment Co., Ltd.), biomixer ( Nippon Seiki Seisakusho Co., Ltd.), turbo-type stirrer (Kodaira Seisakusho Co., Ltd.), Ultra Disper (Asada Steel Co., Ltd.), Ebara Mileser (Ebara Seisakusho Co., Ltd.), TK Homomixer, TK Lab Disper, TK Pipeline There are mixers, TK homomic line mills, TK homojetters, TK unimixers, TK homomic line flows, TK azi homodispers (hereinafter, Primix Co., Ltd.), and the like. Although these stirring apparatuses are mainly used independently, depending on the case, you may use it in combination of 2 or more types as appropriate.

(Measurement of surfactant concentration)
The measurement of the surfactant concentration in the toner dispersion can be performed, for example, by the following method. The surfactant used in the toner dispersion is dropped 0.01% by mass on an aqueous medium, the electrical conductivity at that time is measured, and a calibration curve for the surfactant is prepared. The electrical conductivity of the toner dispersion is measured, and the surfactant concentration in the toner dispersion can be calculated from the calibration curve obtained.

(BET specific surface area)
The BET specific surface area of the toner particles was measured using an automatic specific surface area / pore distribution measuring device (TriStar 3000: manufactured by Shimadzu Corporation). About 0.5 g of a sample was weighed in a sample cell, and this was vacuum-dried for 24 hours with a pretreatment smart prep (manufactured by Shimadzu Corporation) to remove impurities and moisture on the sample surface. The pretreated sample is set in TriStar 3000, and the relationship between the nitrogen gas adsorption amount and the relative pressure is obtained. From this relationship, the BET specific surface area of the sample can be obtained by the BET multipoint method.

(wax)
As the wax, it is preferable to use a long-chain hydrocarbon having a melting point of 50 to 90 [° C.] and forming a molecular chain only with a C—H bond and a C—C bond. Examples of the long-chain hydrocarbon include microcrystalline wax, paraffin wax, polyethylene wax, polypropylene wax, and sazol wax. Among these, a microcrystalline wax having a low melting point is preferable from the viewpoint of a small amount of volatile components at the time of fixing and an improvement in low-temperature fixability.
The wax preferably has a melt viscosity at 140 ° C. of 6 to 15 [mPa · S].
Further, the weight loss at 165 ° C. of the wax is preferably 10% by mass or less. Thereby, the volatile content at the time of fixing can be reduced. The weight loss at 165 ° C. of the wax is more preferably 3% by mass or less.

  As the melting point of the wax, those having a low melting point are preferable from the viewpoint of improving low-temperature fixability, those having a melting point of 50 ° C to 90 ° C are preferably used, and those having a melting point of 50 ° C to 78 ° C are more preferable. The thing of 60-78 degreeC is still more preferable. If the melting point is less than 50 ° C., the wax may adversely affect the heat resistant storage stability, and if it exceeds 90 ° C., a cold offset may easily occur during fixing at a low temperature. Furthermore, when the wax is dispersed in the liquid, the wax is once melted in the liquid and cooled to form a dispersion. When the melting point of the wax exceeds 90 ° C., the boiling point of the liquid in which the wax is dispersed is increased. It must be higher than 90 ° C. When such a solvent is used, when the solvent is removed, the temperature may become higher than the glass transition point of the toner, and the toner may cause blocking. As a means for lowering the melting point of the wax, it is general to lower the molecular weight of the wax. However, the volatile matter increases when the molecular weight of the wax is simply lowered. Microcrystalline wax is preferred from the viewpoint of lowering the melting point of the wax and reducing the volatile content at the time of fixing the wax.

  In addition, the wax that satisfies such requirements may deteriorate the separation between the roller and the paper at the time of fixing to the paper. For this reason, it is necessary to give the toner a certain amount of gel. The separation of the roller and the paper at the time of fixing can be improved by the gel content in the toner. The gel content in the toner can be measured as a content insoluble in tetrahydrofuran (THF). The THF insoluble content is preferably 5% by mass to 25% by mass. When the THF-insoluble content is 5% by mass or more, the deterioration of separation at the time of fixing is suppressed. Moreover, if it is 25 mass% or less, the deterioration of low temperature fixability will be suppressed.

When the surface treatment step and the wax are combined, a bleed out of the wax from the toner may be seen in the surface treatment step. When the wax bleeds out, various problems are caused by contamination of the other members by the wax. For example, in a developer in which a toner and a carrier are mixed, the carrier is contaminated with wax over time, and the charging ability of the developer is reduced. Also, wax contamination on the photoconductor occurs and print image abnormality is observed. Therefore, it is important to prevent bleed out from the toner in surface smoothing. For the reasons described above, in the surface treatment step, the time for maintaining the toner dispersion temperature (T1) is most preferably 1 minute or more and 1 hour or less, and further preferably 3 minutes or more and 50 minutes or less. If it is shorter than 1 minute, the ratio Sbet / SF between the BET specific surface area (Sbet) of the toner and the average circularity (SF) of the toner tends to be less than 1.0 m ² / g. If it is longer than 1 hour, contamination of other members is observed due to bleed-out of wax or the like.

  The circularity can be measured by, for example, the following method. It can be measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics). As a specific measurement method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1 to 0.5 g of sample. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the shape and distribution of the toner are measured with the above apparatus with the dispersion concentration being 3000 to 10,000 / μl. can get.

  The melt viscosity of the wax specified in the present invention is measured by a Brookfield method using a B-type viscometer. In the measurement, the measurement sample is heated from room temperature, and a value at a temperature equal to or higher than the melting temperature of the sample and at a temperature of 140 ° C. approximate to the actual fixing temperature is preferable.

  In the toner of the present invention, the total amount of wax in the toner particles showing the dispersion state of the wax can be defined by the following measurement. The total amount of wax in the toner particles is obtained by a DSC (Differential Scanning Calorimeter) method. Each of the toner sample and the single wax sample is measured by the following measuring device and conditions, and each is obtained from the ratio of the endothermic amounts of the waxes obtained.

・ Measurement device: DSC device (DSC60; manufactured by Shimadzu Corporation)
-Sample amount: about 5mg
-Temperature rising temperature: 10 ° C / min
Measurement range: room temperature to 150 ° C
・ Measurement environment: In nitrogen gas atmosphere

The total amount of wax was calculated by the following formula (1).
Total amount of wax (% by mass) = (Endothermic amount of wax of toner sample (J / g)) × 100)
/ (Endothermic amount of wax alone (J / g)) (1)

  According to the above measurement, the total amount of wax in the toner particles can be effectively defined even when the wax flows out during the toner manufacturing process and not all of the charged wax is contained in the toner.

The insoluble content of tetrahydrofuran (THF) contained in the toner of the present invention is preferably 5 to 25% by mass. If the insoluble content is less than 5% by mass, the molecular weight of the resin in the toner is too low, causing a problem that the upper limit of fixing is lowered. If it exceeds 25% by mass, the molecular weight of the resin in the toner is too high, so that the lower limit of fixing is raised and the fixing temperature range is narrowed.
The THF (tetrahydrofuran) insoluble matter of the toner can be specified by the measurement method shown below.

(1) Weigh about 1.0 g (A) of toner.
(2) About 50 g of THF is added to this and allowed to stand at 20 ° C. for 24 hours.
(3) This is first separated by centrifugation and filtered using a quantitative filter paper.
(4) The solvent content of this filtrate is vacuum-dried, and the residual amount (B) is measured only for the resin content.
This residual amount (B) is the THF dissolved content.
The THF insoluble content (%) is obtained from the following formula (2).
THF-insoluble matter (%) = [(A−B) / A] × 100 Formula (2)

(Wax dispersant)
In the toner of the present invention, a wax dispersant can be contained together with a binder resin, a colorant, and a release agent (wax). By containing the wax dispersant, the dispersibility of the release agent in the binder resin is improved, and the dispersion state of the release agent can be easily controlled by the contents of the release agent and the wax dispersant. Furthermore, although the toner of the present invention contains 50% by mass to 100% by mass of the polyester resin, the polyester resin and the wax of the present invention have almost no compatibility. When the wax dispersant is not used, the wax may not be introduced into the toner and may be discharged to an aqueous medium. Also, the wax may be liberated on the toner surface, or the wax on the toner surface may increase and other components may be removed. Causes contamination. From these aspects, it is preferable to use a wax dispersant.

  As the wax dispersant, a graft polymer having a structure in which a resin (D) described below is used as a main chain and a resin (E) described later as a side chain is grafted is preferable. As the resin (D), any resin that can be grafted with the resin (E) may be used, and a known release agent may be used. For example, a polyolefin resin, more preferably a heat-reduced polyolefin resin is preferable. Examples of olefins constituting the polyolefin resin include ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene and 1-octadecene. Examples of the polyolefin resin include olefin polymers, olefin polymer oxides, modified olefin polymers, and copolymers with other monomers copolymerizable with olefins. .

  Examples of the olefin polymers include polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, propylene / 1-hexene copolymer, and the like. Examples of the olefin polymer oxide include oxides of the above olefin polymers. Examples of modified products of olefin polymers include maleic acid derivative (maleic anhydride, monomethyl maleate, monobutyl maleate, dimethyl maleate, etc.) adducts of the above olefin polymers.

  Examples of copolymers with other monomers copolymerizable with olefins include unsaturated carboxylic acids [(meth) acrylic acid, itaconic acid, maleic anhydride, etc.], unsaturated carboxylic acid alkyl esters [(meth) And copolymers of monomers and olefins such as alkyl acrylate (C1-C18) ester, alkyl maleate (C1-C18) ester, etc.].

  In the present invention, the polymer structure only needs to have a polyolefin structure, and the monomer does not necessarily have an olefin structure. For example, polymethylene (such as sasol wax) can be used. Among these polyolefin resins, preferred are olefin polymers, oxides of olefin polymers, and modified products of olefin polymers, more preferably polyethylene, polymethylene, polypropylene, ethylene / propylene heavy polymers. Polymers, oxidized polyethylene, oxidized polypropylene, maleated polypropylene, and particularly preferred are polyethylene and polypropylene.

  The monomer constituting the resin (E) is an alkyl (carbon number 1 to 5) ester of unsaturated carboxylic acid [methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) Acrylate etc.], vinyl ester monomers [vinyl acetate etc.]. Among these, an alkyl (meth) acrylate is preferable, and an alkyl (meth) acrylate (E1) having an alkyl chain with 1 to 5 carbon atoms is more preferable.

  As the aromatic vinyl monomer (E2) used together with (E1) as a monomer constituting the resin (E), styrene monomers [styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, p-methoxy are used. Styrene, p-hydroxystyrene, p-acetoxystyrene, vinyl toluene, ethyl styrene, phenyl styrene, benzyl styrene, etc.]. Of these, styrene is preferred.

In the toner of the present invention, the ratio (D) / (E) between the resin (D) as the main chain of the wax dispersant and the resin (E) as the side chain is preferably 1 to 50 in terms of mass ratio. If the ratio is larger than 50, the compatibility of the wax dispersant and the binder resin is deteriorated, and if it is smaller than 1, the wax dispersant is not sufficiently compatible with the added release agent and the dispersion of the release agent is deteriorated. Because. In the toner of the present invention, the wax dispersant is preferably 0.01 to 8 parts by weight, more preferably 0.5 to 6 parts by weight with respect to the toner. By setting the amount within this range, the amount of the release agent present on the toner surface is appropriately maintained, in particular, the releasability from the fixing roller and the belt is improved, and the effect of excellent smear resistance is exhibited. Can do.
Moreover, it is preferable to contain 10-300 mass% of wax dispersants with respect to the said wax, and it is still more preferable to contain 40 mass%-80 mass%.

  Moreover, it is preferable that the glass transition temperature of a wax dispersant is 55-80 degreeC, More preferably, it is 55-70 degreeC. If it is higher than 80 ° C., the low-temperature fixability is impaired, and conversely if it is lower than 55 ° C., the hot offset resistance is deteriorated.

(Volume average particle size of wax dispersed particles (particulate particle size))
Whether or not at least a part of the wax exists as a plurality of independent wax dispersion particles encapsulated in the toner particles, or the dispersion state of the wax in the toner particles was observed with a TEM (transmission electron microscope). . Specifically, the toner was embedded in an epoxy resin, sliced to about 100 μm, dyed with ruthenium tetroxide, and then the cross section of the toner was observed with a TEM at a magnification of 10,000 times. FIG. 1 is a cross-sectional TEM photograph of the toner of the present invention. It can be seen that the wax is dispersed in the vicinity of the toner particle surface and is uniformly dispersed inside. With such a dispersion state, even if the amount of wax contained in the toner particles is small, the hot offset resistance is effectively improved and the chargeability, developability, and blocking resistance of the toner are reduced. There is no.

  It is preferable that the wax dispersed particles are uniformly dispersed in the toner particles. Here, uniformly dispersing means that a plurality of wax-dispersed particles are dispersed in the toner particles without a large uneven distribution. For example, in an arbitrary toner cross section including the toner center, the radius connecting the arbitrary point on the toner outer periphery and the toner center is located at a length of 2/3 of the radius from the toner center toward the toner outer periphery. It is also preferable that the wax dispersed particles in the inner region of the circumference be larger than 30% by number and less than 60% by number with respect to all the wax dispersed particles on the toner cross section. The exposed area of the wax on the outermost surface of the toner particles is preferably 5% or less of the surface area of the outermost surface of the toner particles.

  The toner material liquid is formed by dispersing at least the wax in the oil-based medium. The volume average particle diameter of the wax dispersion particles in the toner material liquid is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably minute, for example, 0.1 to 2 μm. Preferably, 0.1-1 micrometer is more preferable. When the volume average particle diameter of the dispersed particles of the wax is less than 0.1 μm, sufficient release performance may be obtained and may not be sufficiently obtained. When the volume average particle diameter exceeds 2 μm, the uniform dispersibility of the wax in the toner may be obtained. May get worse. The volume average particle diameter of the wax dispersion particles can be controlled by the amount of the wax dispersant and the wax dispersion conditions. Increasing the wax dispersant or increasing the dispersion condition reduces the dispersed particle size.

  It is preferable to use a bead mill for the dispersion of the wax. Increasing the dispersion condition is to increase the dispersion time, to speed up the bead mill rotation speed, and to reduce the bead particle size. The bead mill preferably has a bead particle size of 0.05 to 3 mm. When the bead particle size is larger than 3 mm, the dispersion cannot be sufficiently performed, and when the bead size is less than 0.05 mm, it is difficult to separate the beads with a bead mill separator and it is difficult to maintain the dispersion.

(Binder resin)
The binder resin exhibits adhesiveness to a recording material such as paper, and has reactivity with the binder resin and / or the active hydrogen group-containing compound and the active hydrogen group-containing compound. It preferably contains an adhesive polymer (reactant) obtained by reacting a polymer (binder resin precursor) in the step of emulsifying or dispersing in an aqueous medium. By containing these, it becomes possible to easily add a gel component to the toner. Furthermore, a binder resin appropriately selected from known binder resins may be included.

The weight average molecular weight of the binder resin is preferably 3,000 to 45,000, more preferably 4,000 to 30,000, and particularly preferably 4,000 to 20,000. When the weight average molecular weight is less than 3,000, the hot offset resistance may be lowered.
When a polyester resin is contained as the binder resin, the weight average molecular weight of the tetrahydrofuran (THF) soluble component is preferably 3,000 to 30,000.

  The glass transition temperature of the binder resin is preferably 35 ° C to 65 ° C, and more preferably 45 ° C to 65 ° C. When the glass transition temperature is less than 35 ° C., the heat-resistant storage stability of the toner may deteriorate, and when it exceeds 65 ° C., the low-temperature fixability may not be sufficient. Note that a toner containing a polyester resin subjected to a crosslinking reaction or elongation reaction as a binder resin has good storage stability even when the glass transition temperature is low.

  In the present invention, the binder resin can be appropriately selected according to the purpose, and a polyester resin or the like can be used, but an unmodified polyester resin (unmodified polyester resin) is preferable. The acid value of the unmodified polyester resin is 12 to 30 mgKOH / g, and preferably 15 to 25 mgKOH / g. Generally, it becomes easy to be negatively charged by giving the toner an acid value.

  Further, in the present invention, an active hydrogen group-containing compound and a polymer having reactivity to the active hydrogen group are contained, and in the step of emulsifying or dispersing in the aqueous medium, the compound and the polymer are reacted, In the case of a toner containing the obtained reaction product as a binder resin, the reason is not clear, but when the acid value of the unmodified polyester resin is lower than 12 mgKOH / g, the reaction rate is increased and the viscosity of the toner material liquid is increased. It becomes high and it becomes difficult to emulsify and disperse in an aqueous medium. Moreover, when higher than 30 mgKOH / g, hot offset property deteriorates. The binder resin is appropriately selected according to the purpose, but a polyester resin or the like is preferably used. Here, the toner of the present invention preferably contains 50% by mass to 100% by mass of a polyester resin in the binder resin.

  The binder resin precursor is not particularly limited and may be appropriately selected depending on the intended purpose. A modified polyester resin capable of reacting with a compound having an active hydrogen group is preferably used. The modified polyester resin capable of reacting with the compound having an active hydrogen group is preferably a polyester having an isocyanate group as a polymer having reactivity with the active hydrogen group. In addition, you may form a urethane bond by adding alcohol when making the isocyanate group containing polyester resin and the compound which has an active hydrogen group react. The molar ratio of the urethane bond to the urea bond thus formed (to distinguish it from the urethane bond of the polyester prepolymer having an isocyanate group) is preferably from 0 to 9, and preferably from 1/4 to 4. Is more preferable, and 2/3 to 7/3 is particularly preferable. If this ratio is greater than 9, the hot offset resistance may decrease.

  Specific examples of the binder resin include a bisphenol A ethylene oxide 2-mole adduct and a polyester prepolymer obtained by reacting a polycondensate of isophthalic acid with isophorone diisocyanate, and bisphenol A ethylene oxide 2 A mixture of a molar adduct and a polycondensate of isophthalic acid, a polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid with isophorone diisocyanate, and urethanization with isophoronediamine A mixture of ethylene oxide 2 mol adduct and terephthalic acid polycondensate, bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid A mixture of a polyester prepolymer obtained by reacting a polycondensate with isophorone diisocyanate with isophorone diamine and a polycondensate of bisphenol A ethylene oxide 2-mole adduct / bisphenol A propylene oxide 2-mole adduct and terephthalic acid A bisphenol A ethylene oxide 2-mole adduct / bisphenol A propylene oxide 2-mole adduct and a polyester prepolymer obtained by reacting a polycondensate of terephthalic acid with isophorone diisocyanate, and bisphenol A propylene oxide 2 A mixture of a molar adduct and a polycondensate of terephthalic acid, a bisphenol A ethylene oxide 2 molar adduct and a polycondensate of terephthalic acid with isophorone diisocyanate A mixture of a polyester prepolymer prepared by ureation with hexamethylenediamine and a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid, a mixture of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid A mixture of a polyester prepolymer obtained by reacting a condensate with isophorone diisocyanate and uread with hexamethylenediamine, and a polycondensate of bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid A polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid with isophorone diisocyanate, and urethanized with ethylenediamine, A polyester prepolymer prepared by reacting a bisphenol A ethylene oxide 2-mole adduct and a polycondensate of terephthalic acid with diphenylmethane diisocyanate with hexamethylene diamine. Mixtures of ureas and polycondensates of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid, bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid / dodecenyl succinic anhydride A polyester prepolymer obtained by reacting a polycondensate of the above with diphenylmethane diisocyanate and uread with hexamethylenediamine, and a bisphenol A ethylene oxide 2-mol adduct / bisphenol. A polyester prepolymer prepared by reacting bisphenol A ethylene oxide 2 mol adduct and isophthalic acid polycondensate with toluene diisocyanate with hexamethylene diamine. Examples thereof include a mixture of a urea compound and a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid.

  The compound having an active hydrogen group acts as an elongation agent, a crosslinking agent or the like when a polymer having reactivity to the active hydrogen group undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous medium. Specific examples of the active hydrogen group include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), amino group, carboxyl group, mercapto group and the like. In addition, an active hydrogen group may be individual, and 2 or more types of mixtures may be sufficient as it. The compound having an active hydrogen group can be appropriately selected according to the purpose. However, when the polymer having reactivity to the active hydrogen group is a polyester prepolymer having an isocyanate group, the compound has an elongation with the polyester prepolymer. Amines are preferred because they can be increased in molecular weight by reaction, crosslinking reaction or the like.

  The amines are not particularly limited and may be appropriately selected depending on the intended purpose. Specifically, diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and these amino groups are blocked. Among them, diamine and a mixture of diamine and a small amount of trivalent or higher amine are preferable. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the diamine include aromatic diamines, alicyclic diamines, and aliphatic diamines. Specific examples of the aromatic diamine include phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, and the like. Specific examples of the alicyclic diamine include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, isophorone diamine and the like. Specific examples of the aliphatic diamine include ethylene diamine, tetramethylene diamine, hexamethylene diamine and the like. Specific examples of the trivalent or higher amine include diethylenetriamine and triethylenetetramine. Specific examples of amino alcohols include ethanolamine and hydroxyethylaniline. Specific examples of amino mercaptans include aminoethyl mercaptan and aminopropyl mercaptan. Specific examples of amino acids include aminopropionic acid and aminocaproic acid. Specific examples of those in which the amino group is blocked include ketimine compounds and oxazolidone compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

  In addition, a reaction terminator can be used in order to stop the elongation reaction, the crosslinking reaction, and the like of the compound having an active hydrogen group and a polymer having reactivity with the active hydrogen group. When a reaction terminator is used, the molecular weight and the like of the adhesive substrate can be controlled within a desired range. Specific examples of the reaction terminator include monoamines such as diethylamine, dibutylamine, butylamine and laurylamine, and ketimine compounds in which these amino groups are blocked. The ratio of the equivalent of the isocyanate group of the polyester prepolymer to the equivalent of the amino group of the amine is preferably 1/3 to 3, more preferably 1/2 to 2, and particularly preferably 2/3 to 1.5. . If this ratio is less than 1/3, the low-temperature fixability may be lowered. If it exceeds 3, the molecular weight of the urea-modified polyester resin may be lowered, and the hot offset resistance may be lowered.

  The polymer having reactivity to active hydrogen groups (hereinafter sometimes referred to as “prepolymer”) can be appropriately selected from known resins and the like, and can be selected from polyol resins, polyacrylic resins, polyester resins, and epoxy resins. And derivatives thereof. Among them, it is preferable to use a polyester resin in terms of high fluidity and transparency at the time of melting. These may be used alone or in combination of two or more. Examples of the functional group capable of reacting with the active hydrogen group of the prepolymer include an isocyanate group, an epoxy group, a carboxyl group, and a functional group represented by the chemical structural formula -COC-, among which an isocyanate group is preferable. . The prepolymer may have one of such functional groups or two or more kinds.

  As a prepolymer, the molecular weight of the polymer component can be easily adjusted, and oil-less low-temperature fixing characteristics in dry toners, in particular, good releasability and fixability even in the absence of a release oil application mechanism to a fixing heating medium. Since it can ensure, it is preferable to use the polyester resin which has an isocyanate group etc. which can produce | generate a urea bond. The polyester prepolymer containing an isocyanate group can be appropriately selected depending on the purpose. Specific examples include a reaction product of a polyester resin having an active hydrogen group obtained by polycondensation of a polyol and a polycarboxylic acid, and a polyisocyanate.

  The polyol is not particularly limited and can be appropriately selected depending on the purpose. A diol, a trihydric or higher alcohol, a mixture of a diol and a trihydric or higher alcohol, and the like can be used. A trihydric or higher alcohol mixture is preferred. These may be used individually by 1 type and may use 2 or more types together.

  Specific examples of the diol include alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol; diethylene glycol, triethylene glycol, dipropylene Diols having an oxyalkylene group such as glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols including ethylene oxide and propylene oxide , With addition of alkylene oxide such as butylene oxide; bisphenols such as bisphenol A, bisphenol F and bisphenol S; bisphenols with ethyleneoxy , Propylene oxide, alkylene oxide adducts of bisphenols such as those obtained by adding alkylene oxides such as butylene oxide. In addition, it is preferable that carbon number of alkylene glycol is 2-12. Among these, alkylene glycols having 2 to 12 carbon atoms or alkyne oxide adducts of bisphenols are preferable, alkylene oxide adducts of bisphenols or alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. The mixture of is particularly preferred.

  Examples of trihydric or higher alcohols include trihydric or higher aliphatic alcohols, trihydric or higher polyphenols, and alkylene oxide adducts of trihydric or higher polyphenols. Specific examples of the trihydric or higher aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol and the like. Specific examples of the trihydric or higher polyphenols include trisphenol PA, phenol novolak, cresol novolak and the like. Specific examples of adducts of trivalent or higher polyphenols with alkylene oxides include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide to trihydric or higher polyphenols. When a diol and a trihydric or higher alcohol are mixed and used, the mass ratio of the trihydric or higher alcohol to the diol is preferably 0.01% by mass to 10% by mass, and 0.01% by mass to 1% by mass. Is more preferable.

The polycarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dicarboxylic acids, trivalent or higher carboxylic acids, and mixtures of dicarboxylic acids and trivalent or higher carboxylic acids. A dicarboxylic acid or a mixture of a dicarboxylic acid and a small amount of a trivalent or higher polycarboxylic acid is preferred. These may be used alone or in combination of two or more.
Specific examples of the dicarboxylic acid include divalent alkanoic acid, divalent alkenoic acid, and aromatic dicarboxylic acid. Specific examples of the divalent alkanoic acid include succinic acid, adipic acid, sebacic acid and the like. The number of carbon atoms of the divalent alkenoic acid is preferably 4 to 20, and specific examples include maleic acid and fumaric acid. The aromatic dicarboxylic acid preferably has 8 to 20 carbon atoms, and specific examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Among these, a divalent alkenoic acid having 4 to 20 carbon atoms or an aromatic dicarboxylic acid having 8 to 20 carbon atoms is preferable.

  As the trivalent or higher carboxylic acid, trivalent or higher aromatic carboxylic acid or the like can be used. The carbon number of the trivalent or higher aromatic carboxylic acid is preferably 9 to 20, and specific examples thereof include trimellitic acid and pyromellitic acid. As the polycarboxylic acid, an acid anhydride or lower alkyl ester of any of dicarboxylic acid, trivalent or higher carboxylic acid, and a mixture of dicarboxylic acid and trivalent or higher carboxylic acid can be used. Specific examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like.

  When a dicarboxylic acid and a trivalent or higher carboxylic acid are mixed and used, the mass ratio of the trivalent or higher carboxylic acid to the dicarboxylic acid is preferably 0.01% by mass to 10% by mass, and 0.01% by mass. -1 mass% is more preferable. As for the mixing ratio at the time of polycondensation of the polyol and the polycarboxylic acid, the equivalent ratio of the hydroxyl group of the polyol to the carboxyl group of the polycarboxylic acid is usually preferably 1 to 2, more preferably 1 to 1.5, 1.02-1.3 is particularly preferred.

  The content of the structural unit derived from the polyol in the polyester prepolymer having an isocyanate group is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and 2% by mass to 20%. Mass% is particularly preferred. When the content is less than 0.5% by mass, the hot offset resistance is lowered, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability of the toner, and exceeds 40% by mass. In this case, the low-temperature fixability may be lowered.

  The polyisocyanate can be appropriately selected depending on the purpose, but it is blocked with an aliphatic diisocyanate, an alicyclic diisocyanate, an aromatic diisocyanate, an araliphatic diisocyanate, an isocyanurate, or the like, blocked with a phenol derivative, oxime, caprolactam, or the like. And the like.

  Specific examples of the aliphatic diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetra And methyl hexane diisocyanate. Specific examples of the alicyclic diisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate. Specific examples of the aromatic diisocyanate include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4′-diisocyanatodiphenyl, 4,4′-diisocyanato-3,3′-dimethyldiphenyl. 4,4′-diisocyanato-3-methyldiphenylmethane, 4,4′-diisocyanato-diphenyl ether, and the like. Specific examples of the araliphatic diisocyanate include α, α, α ′, α′-tetramethylxylylene diisocyanate. Specific examples of the isocyanurates include tris (isocyanatoalkyl) isocyanurate, tris (isocyanatocycloalkyl) isocyanurate, and the like. These may be used individually by 1 type and may use 2 or more types together.

  When the polyisocyanate and the polyester resin having a hydroxyl group are reacted, the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyester resin is usually preferably 1 to 5, more preferably 1.2 to 4, more preferably 1 .5-3 are particularly preferred. When the equivalent ratio exceeds 5, the low-temperature fixability may decrease, and when it is less than 1, the offset resistance may decrease.

  The content of the structural unit derived from polyisocyanate in the polyester prepolymer containing an isocyanate group is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and 2% by mass. -20 mass% is still more preferable. When the content is less than 0.5% by mass, the hot offset resistance may be deteriorated, and when it exceeds 40% by mass, the low-temperature fixability may be deteriorated.

  The average number of isocyanate groups that the polyester prepolymer has per molecule is preferably 1 or more, more preferably 1.2 to 5, and still more preferably 1.5 to 4. When the average number is less than 1, the molecular weight of the urea-modified polyester resin is lowered, and the hot offset resistance may be lowered.

  1000-30000 are preferable and, as for the mass average molecular weight of the polymer which has the reactivity with respect to an active hydrogen group, 1500-15000 are more preferable. When the mass average molecular weight is less than 1000, the heat-resistant storage stability may be lowered, and when it exceeds 30000, the low-temperature fixability may be lowered.

The said mass mean molecular weight can be calculated | required by measuring a tetrahydrofuran soluble part, for example using a gel permeation chromatography (GPC). Here, the GPC measurement can be performed as follows, for example. First, the column is stabilized in a 40 ° C. heat chamber. At this temperature, tetrahydrofuran is used as a column solvent at a flow rate of 1 ml per minute, and 50 to 200 μl of a tetrahydrofuran solution adjusted to a sample concentration of 0.05 to 0.6% by mass is injected and measured. In measuring the molecular weight, the molecular weight is calculated from the relationship between the logarithmic value of the calibration curve prepared from several kinds of standard samples and the number of counts. As standard samples for preparing a calibration curve, the molecular weight is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ and 4.48 × 10 ⁶ monodisperse polystyrene (manufactured by Pressure Chemical or Toyo Soda Industry Co., Ltd.) can be used. At this time, it is preferable to use about 10 kinds of standard samples. A refractive index detector can be used as the detector.

  In the present invention, the binder resin can be appropriately selected depending on the purpose, and a polyester resin or the like can be used, but it is more preferable to contain an unmodified polyester resin that is not modified. Thereby, low temperature fixability and glossiness can be improved. Examples of the unmodified polyester resin include a polycondensate of a polyol and a polycarboxylic acid. The unmodified polyester resin is partially compatible with the urea-modified polyester resin, that is, has a similar structure compatible with each other, in terms of low-temperature fixability and hot offset resistance. preferable.

  The mass average molecular weight of the unmodified polyester resin is preferably 1,000 to 30,000, more preferably 1,500 to 15,000. When the mass average molecular weight is less than 1,000, the heat resistant storage stability may be lowered. For this reason, it is preferable that content of the component whose said mass mean molecular weight is less than 1,000 is 8 mass%-28 mass%. On the other hand, if the mass average molecular weight exceeds 30,000, the low-temperature fixability may deteriorate.

  The glass transition temperature of the unmodified polyester resin is preferably 30C to 70C, more preferably 35C to 60C, and still more preferably 35C to 55C. When the glass transition temperature is less than 30 ° C., the heat-resistant storage stability of the toner may be lowered, and when it exceeds 70 ° C., the low-temperature fixability may be lowered.

  The hydroxyl value of the unmodified polyester resin is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g to 120 mgKOH / g, and still more preferably 20 mgKOH / g to 80 mgKOH / g. When the hydroxyl value is less than 5 mgKOH / g, it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability.

  The acid value of the unmodified polyester resin is preferably 1.0 mgKOH / g to 50.0 mgKOH / g, and more preferably 1.0 mgKOH / g to 30.0 mgKOH / g. Thereby, the toner is easily negatively charged.

  When the toner contains an unmodified polyester resin, the mass ratio of the polyester prepolymer having an isocyanate group to the unmodified polyester resin is preferably 5/95 to 25/75, more preferably 10/90 to 25/75. preferable. When the mass ratio is less than 5/95, the hot offset resistance may be lowered, and when it exceeds 25/75, the low-temperature fixability and the glossiness of the image may be lowered.

(Coloring agent)
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and lithobon. These may be used individually by 1 type and may use 2 or more types together.

The content of the colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass.
When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, the pigment is poorly dispersed in the toner. The characteristics may be degraded.
The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, a styrene copolymer, 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 hydrocarbon resin, alicyclic ring Aromatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin, and the like. These may be used individually by 1 type and may use 2 or more types together.

  In addition to the above components, the toner of the present invention can further contain a charge control agent, resin fine particles, inorganic fine particles, fluidity improver, cleaning property improver, magnetic material, metal soap, and the like.

-Toner material liquid-
The toner material liquid is obtained by dissolving or dispersing a material constituting the toner in an oil-based medium. The material constituting the toner is not particularly limited as long as the toner can be formed, and can be appropriately selected according to the purpose. Examples of the material constituting the toner include a monomer, a polymer, an active hydrogen group-containing compound, And a polymer (prepolymer) capable of reacting with the active hydrogen group-containing compound, and at least a colorant and a wax, and further, if necessary, other components such as a charge control agent. .

  In the method for producing a toner according to a preferred embodiment of the present invention, the toner material liquid is prepared in an oil-based medium by an active hydrogen group-containing compound, a polymer capable of reacting with the active hydrogen group-containing compound, wax, coloring It is possible to carry out by dissolving or dispersing a toner material such as an agent or a charge control agent. Among the materials constituting the toner, other than the polymer (prepolymer) capable of reacting with the active hydrogen group-containing compound. The components may be added and mixed in the aqueous medium in the preparation of the aqueous medium described later, or may be added to the aqueous medium together with the toner material liquid when the toner material liquid is added to the aqueous medium. .

  The oil-based medium is a solvent capable of dissolving or dispersing the material constituting the toner, and the solvent preferably contains an organic solvent. Further, the organic solvent is preferably removed when the toner base particles are formed or after the toner base particles are formed. From the viewpoint of ease of removal, a volatile solvent having a boiling point of less than 150 ° C. is preferred. When the boiling point is 150 ° C. or more, toner aggregation may occur when the solvent is removed. Examples of such solvents 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. Among these, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is particularly preferable. These may be used individually by 1 type and may use 2 or more types together. There is no restriction | limiting in particular as the usage-amount of the said organic solvent, According to the objective, it can select suitably, For example, 40-300 mass parts is preferable with respect to 100 mass parts of toner materials, and 60-140 mass parts is more. 80 to 120 parts by mass are more preferable.

(Charge control agent)
The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material is used. It is preferable to use it. Specifically, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts including fluorine-modified quaternary ammonium salts, alkylamides, phosphorus alone or compounds thereof, tungsten alone Or a compound thereof, a fluorosurfactant, a metal salt of salicylic acid, a metal salt of a salicylic acid derivative, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Commercially available products may be used as the charge control agent. Examples of commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E-84, E-89 of phenol condensate (above, manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415 of quaternary ammonium salt molybdenum complex (above, manufactured by Hodogaya Chemical Co., Ltd.), copy charge of quaternary ammonium salt PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, boron complex LR-147 (manufactured by Nippon Carlit) , Quinacridone, azo pigments, other sulfonic acid groups, carboxyl groups, quaternary ammonia Examples thereof include polymers having a functional group such as a nium salt.

  The charge control agent may be dissolved or dispersed after being melt-kneaded with the master batch, or may be dissolved or dispersed in a solvent together with each component of the toner, and may be fixed on the surface of the toner after the toner is produced. Also good. The content of the charge control agent in the toner varies depending on the type of the binder resin, the presence or absence of the additive, the dispersion method, and the like, and cannot be generally specified, but is 0.1% by mass to the binder resin. It is preferable that it is 10 mass%, and 0.2 mass%-5 mass% are more preferable. When the content is less than 0.1% by mass, the charge controllability may not be obtained. When the content exceeds 10% by mass, the chargeability of the toner becomes too large, and the electrostatic attractive force with the developing roller is low. May increase, resulting in a decrease in developer fluidity and a decrease in image density.

(Resin particles)
The resin particles are not particularly limited as long as they can form an aqueous dispersion in an aqueous medium, and can be appropriately selected from known resins according to the purpose, and may be thermoplastic resins. However, it may be a thermosetting resin. Specific examples include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, polycarbonate resins, and the like. Among these, one or more resins selected from the group consisting of vinyl resins, polyurethane resins, epoxy resins, and polyester resins are preferable because an aqueous dispersion of fine spherical resin particles is easily obtained. These may be used individually by 1 type and may use 2 or more types together.

  The vinyl resin is a resin obtained by homopolymerizing or copolymerizing a vinyl monomer. Specifically, a styrene- (meth) acrylic acid ester copolymer, a styrene-butadiene copolymer, (meth) Acrylic acid-acrylic acid ester polymer, styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.

  Moreover, as the resin particles, a copolymer obtained by polymerizing a monomer having a plurality of unsaturated groups can also be used. The monomer having a plurality of unsaturated groups can be appropriately selected according to the purpose. Specifically, sodium salt eleminol RS-30 of methacrylic acid ethylene oxide adduct sulfate (manufactured by Sanyo Chemical Industries), divinylbenzene 1,6-hexanediol diacrylate and the like.

  The resin particles can be obtained by polymerization using a known method, but are preferably used as an aqueous dispersion of resin particles. As a method for preparing an aqueous dispersion of resin particles, in the case of a vinyl resin, an aqueous dispersion of resin particles is obtained by polymerizing a vinyl monomer using a suspension polymerization method, an emulsion polymerization method, a seed polymerization method, or a dispersion polymerization method. In the case of polyaddition or condensation resins such as polyester resins, polyurethane resins, and epoxy resins, a precursor such as a monomer or an oligomer or a solution thereof is dispersed in an aqueous medium in the presence of a suitable dispersant. After that, heating or adding a curing agent to cure, a method for producing an aqueous dispersion of resin particles, a precursor such as a monomer or oligomer, or an appropriate emulsifier is dissolved in the solution, and then water is added. Method of phase inversion emulsification: Resin is pulverized and classified using a mechanical pulverizer or jet pulverizer to obtain resin particles, which are then dispersed in water in the presence of an appropriate dispersant. After obtaining resin particles by spraying a resin solution in the form of a mist, the resin particles are dispersed in water in the presence of an appropriate dispersant, a poor solvent is added to the resin solution, or the solvent is heated. By cooling the dissolved resin solution, the resin particles are precipitated, and after removing the solvent to obtain resin particles, a method of dispersing the resin particles in water in the presence of an appropriate dispersant, a resin solution, Disperse in an aqueous medium in the presence of an appropriate dispersant, then remove the solvent by heating, reduced pressure, etc., dissolve an appropriate emulsifier in the resin solution, and then add water to emulsify the phase. Methods and the like.

(Inorganic particles)
The inorganic particles are not particularly limited and can be appropriately selected from known materials according to the purpose. Specifically, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, Strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate , Silicon carbide, silicon nitride and the like. These may be used individually by 1 type and may use 2 or more types together. The primary particle diameter of the inorganic particles is preferably 5 nm to 2 μm, and more preferably 5 nm to 500 nm. Further, BET specific surface area of the inorganic particles ^is preferably 20m ² / g~500m 2 / g. The content of inorganic particles in the toner is preferably 0.01% by mass to 5.0% by mass.

  When the surface treatment is performed using the fluidity improver, the hydrophobicity of the toner surface is improved, and the deterioration of the flow characteristics and charging characteristics can be suppressed even under high humidity. Specific examples of fluidity improvers include silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. Etc.

  When the cleaning property improving agent is added to the toner, the transferred developer remaining on the photoreceptor or the primary transfer medium is easily removed. Specific examples of the cleaning improver include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, resin particles obtained using soap-free emulsion polymerization such as polymethyl methacrylate particles and polystyrene particles. . The resin particles preferably have a narrow particle size distribution, and preferably have a volume average particle diameter of 0.01 μm to 1 μm.

  There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably from well-known things, and iron powder, a magnetite, a ferrite, etc. are mentioned. Among these, a white magnetic material is preferable in terms of color tone.

(Toner production method)
The method for producing the toner includes a step of emulsifying or dispersing an oil phase (toner material liquid) containing at least a binder resin, a colorant, and a wax in an aqueous medium containing a surfactant. Granulate. As a method for producing a toner by a polymerization method, a method for forming toner base particles while producing an adhesive substrate is shown below. In such a method, preparation of an aqueous medium phase, preparation of a liquid containing a toner material, emulsification or dispersion of the toner material, formation of an adhesive substrate, removal of the solvent, a polymer having reactivity to active hydrogen groups And the synthesis of a compound having an active hydrogen group.

  The aqueous medium can be prepared by dispersing resin particles (mixed as necessary) in the aqueous medium. The addition amount of the resin particles in the aqueous medium is preferably 0.5% by mass to 10% by mass.

  Preparation of the liquid containing the material constituting the toner (toner material) is carried out by using a compound having an active hydrogen group, a polymer having reactivity to the active hydrogen group, a pigment (colorant), a release agent (wax) in a solvent. ), And a toner material (mixed as necessary) such as a charge control agent and an unmodified polyester resin can be dissolved or dispersed.

  In the toner material, components other than the polymer having reactivity with the active hydrogen group may be added and mixed in the aqueous medium when the resin particles are dispersed in the aqueous medium, or the toner material contains the toner material. When the liquid is added to the aqueous medium, it may be added to the aqueous medium, but the toner material liquid preferably contains the above-described binder, colorant, and wax.

  The emulsification or dispersion of the toner material can be performed by dispersing a liquid containing the toner material in an aqueous medium. Then, when the toner material is emulsified or dispersed, an adhesive base is formed by subjecting a compound having an active hydrogen group and a polymer having reactivity to the active hydrogen group to an extension reaction and / or a crosslinking reaction.

  Adhesive substrates such as urea-modified polyester resins contain, for example, a liquid containing a polymer having reactivity with active hydrogen groups such as polyester prepolymers having isocyanate groups, and active hydrogen groups such as amines. It may be produced by emulsifying or dispersing together with a compound in an aqueous medium and subjecting both to an extension reaction and / or a crosslinking reaction in the aqueous medium. It may be produced by emulsifying or dispersing in an added aqueous medium and by subjecting both to an extension reaction and / or a crosslinking reaction in the aqueous medium, and after emulsifying or dispersing the liquid containing the toner material in the aqueous medium. Then, a compound having an active hydrogen group is added, and an extension reaction and / or a cross-linking reaction are performed on both from the particle interface in an aqueous medium. It may be. When both are subjected to an extension reaction and / or a crosslinking reaction from the particle interface, a urea-modified polyester resin is preferentially formed on the surface of the toner to be produced, and a concentration gradient of the urea-modified polyester resin can be provided in the toner.

  The reaction conditions for producing the adhesive substrate can be appropriately selected according to the combination of the polymer having reactivity with active hydrogen groups and the compound having active hydrogen groups. The reaction time is preferably 10 minutes to 40 hours, more preferably 2 hours to 24 hours. The reaction temperature is preferably 150 ° C. or lower, and more preferably 40 ° C. to 98 ° C.

  In a water-based medium, a method for stably forming a dispersion containing a polymer capable of reacting with an active hydrogen group such as a polyester prepolymer having an isocyanate group includes a reaction with an active hydrogen group in the aqueous medium phase. Examples include a method in which a liquid prepared by dissolving or dispersing a toner material such as a polymer, a pigment, a pigment dispersant, a release agent, a charge control agent, and an unmodified polyester resin in a solvent is added and dispersed by shearing force. It is done.

  Dispersion can be performed using a known disperser, and examples of the disperser include a low-speed shear disperser, a high-speed shear disperser, a friction disperser, a high-pressure jet disperser, and an ultrasonic disperser. Although mentioned, since the particle diameter of a dispersion can be controlled to 2-20 micrometers, a high-speed shearing disperser is preferable. When a high-speed shearing disperser is used, conditions such as the number of rotations, dispersion time, dispersion temperature and the like can be appropriately selected according to the purpose. The number of rotations is preferably 1,000 to 30,000 rpm, and more preferably 5,000 to 20,000 rpm. In the case of a batch system, the dispersion time is preferably 0.1 to 5 minutes, and the dispersion temperature is preferably 150 ° C. or less, more preferably 40 ° C. to 98 ° C. under pressure. The dispersion temperature is generally easier to disperse when the temperature is higher.

  The amount of the aqueous medium used when emulsifying or dispersing the toner material is preferably 50 parts by mass to 2000 parts by mass, and more preferably 100 parts by mass to 1000 parts by mass with respect to 100 parts by mass of the toner material. When the amount used is less than 50 parts by mass, the dispersion state of the toner material is deteriorated and toner base particles having a predetermined particle diameter may not be obtained. When the amount exceeds 2000 parts by mass, the production cost is high. May be.

  In the step of emulsifying or dispersing the liquid containing the toner material, it is preferable to use a dispersant from the viewpoint of stabilizing the dispersion such as oil droplets so as to obtain a desired shape and sharpening the particle size distribution. The dispersant can be appropriately selected according to the purpose, and examples thereof include a surfactant, a sparingly water-soluble inorganic compound dispersant, a polymeric protective colloid, and the like, but a surfactant is preferable. These may be used individually by 1 type and may use 2 or more types together.

As the surfactant, an anionic surfactant, a cationic surfactant, a nonionic surfactant, an amphoteric surfactant and the like can be used.
Examples of the anionic surfactant include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters and the like, and those having a fluoroalkyl group are preferably used. Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, perfluorooctanesulfonyl glutamate disodium, 3- [ω-fluoroalkyl (C6 to C11). Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carboxylic acid Or a metal salt thereof, perfluoroalkylcarboxylic acid (C7 to C13) or a metal salt thereof, perfluoroalkyl (C4 to C12) sulfonic acid or a metal salt thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-hydroxyethyl) perfluoroocta Sulfonamides, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salts, monoperfluoroalkyl (C6-C16) ethyl phosphate, and the like. It is done.

  Examples of commercially available surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (above, manufactured by Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC. -129 (manufactured by Sumitomo 3M), Unidyne DS-101, DS-102 (manufactured by Daikin Industries, Ltd.), MegaFuck F-110, F-120, F-113, F-191, F-812, F-833 (above, manufactured by Dainippon Ink Co., Ltd.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (above, manufactured by Tochem Products, Inc.), footagent 100, 150 (above, manufactured by Neos), and the like.

  Examples of the cationic surfactant include amine salt type surfactants such as alkylamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines; alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, Quaternary ammonium salt type surfactants such as pyridinium salts, alkylisoquinolinium salts, benzethonium chloride and the like can be mentioned. Among these, aliphatic primary, secondary or tertiary amino acids having a fluoroalkyl group, aliphatic quaternary ammonium salts such as perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts, benzalkonium salts, chlorides Benzethonium, pyridinium salts, imidazolinium salts and the like are preferable. Commercially available cationic surfactants include, for example, Surflon S-121 (manufactured by Asahi Glass Co., Ltd.); Florard FC-135 (manufactured by Sumitomo 3M); Unidyne DS-202 (manufactured by Daikin Industries Ltd.), MegaFuck F-150, It is preferable to use F-824 (manufactured by Dainippon Ink); Xtop EF-132 (manufactured by Tochem Products);

  Examples of the nonionic surfactant include fatty acid amide derivatives and polyhydric alcohol derivatives. Examples of the amphoteric surfactant include alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine and the like.

  Examples of the poorly water-soluble inorganic compound dispersant include tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite.

  Examples of the polymeric protective colloid include, for example, a monomer having a carboxyl group, an alkyl (meth) acrylate having a hydroxyl group, a vinyl ether, a vinyl carboxylate, an amide monomer, an acid chloride monomer, a monomer having a nitrogen atom or a heterocyclic ring thereof, etc. Homopolymers or copolymers obtained by polymerizing styrene, polyoxyethylene resins, celluloses and the like. In addition, the homopolymer or copolymer obtained by polymerizing the above monomers includes those having a structural unit derived from vinyl alcohol.

  Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride and the like. Examples of the (meth) acrylic monomer containing a hydroxyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, and γ-hydroxy acrylate. Propyl, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, etc. It is done. Specific examples of the vinyl ether include vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, and the like. Examples of vinyl carboxylate include vinyl acetate, vinyl propionate, vinyl butyrate and the like. Examples of the amide monomer include acrylamide, methacrylamide, diacetone acrylamide, N-methylol acrylamide, N-methylol methacrylamide, and the like. Examples of the acid chloride monomer include acrylic acid chloride and methacrylic acid chloride. Examples of the monomer having a nitrogen atom or a heterocyclic ring thereof include vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, and ethyleneimine. Examples of the polyoxyethylene resin include polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene Examples include ethylene lauryl phenyl ether, polyoxyethylene stearate phenyl, polyoxyethylene pelargonate phenyl, and the like. Examples of celluloses include methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and the like.

When emulsifying or dispersing the toner material, a dispersant can be used as necessary.
Examples of the dispersant include acids such as calcium phosphate salts and those that are soluble in alkali. When calcium phosphate is used as the dispersant, the calcium phosphate salt can be removed by dissolving the calcium salt with hydrochloric acid or the like and washing it with water or decomposing with an enzyme.

  A catalyst can be used for the elongation reaction and / or the crosslinking reaction in producing the adhesive substrate. Specific examples of the catalyst include dibutyltin laurate and dioctyltin laurate.

  As a method for removing the organic solvent from the dispersion liquid such as an emulsified slurry, the temperature of the entire reaction system is gradually raised to evaporate the organic solvent in the oil droplets, and the dispersion liquid is sprayed in a dry atmosphere to obtain the oil. Examples include a method of removing the organic solvent in the droplets. When the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, etc., and further classified. Classification may be performed by removing fine particle portions by a cyclone, decanter, centrifugation, or the like in the liquid, or classification may be performed after drying. The obtained toner base particles may be mixed with particles such as a colorant, a release agent, and a charge control agent. At this time, by applying a mechanical impact force, it is possible to prevent particles such as a release agent from detaching from the surface of the toner base particles.

  As a method of applying mechanical impact force, a method of applying impact force to a mixture using a blade rotating at a high speed, throwing the mixture into a high-speed air current, and accelerating the particles or particles to an appropriate collision plate The method of making it collide etc. is mentioned. The equipment used in this method is an ong mill (manufactured by Hosokawa Micron Co., Ltd.), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) to reduce the pulverization air pressure, a hybridization system (manufactured by Nara Machinery Co., Ltd.), crypto Ron system (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar and the like.

  The toner of the present invention can be used in various fields, but can be suitably used for image formation by electrophotography.

  The volume average particle size of the toner of the present invention is preferably 1 μm to 8 μm, more preferably 3 μm to 8 μm, and particularly preferably 4 μm to 7 μm. When the volume average particle diameter is less than 1 μm, in the two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the case of a one-component developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner may occur. On the other hand, when the volume average particle diameter exceeds 8 μm, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle diameter is large. May be. Further, if it is smaller than 1 μm, toner dust is likely to be generated in primary transfer and secondary transfer. Conversely, if it is larger than 8 μm, dot reproducibility becomes insufficient and the graininess of the halftone portion is also deteriorated. As a result, a high-definition image cannot be obtained.

  In the toner of the present invention, the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) of the toner particles is preferably 1.00 to 1.25, preferably 1.05 to 1.05. 1.25 is more preferable. As a result, in the two-component developer, even if the toner balance for a long period of time is performed, the toner particle diameter in the developer is little changed, and good and stable developability can be obtained even in the case of long-term stirring in the developing device. . In the case of a one-component developer, even if the balance of the toner is performed, the fluctuation of the toner particle diameter is reduced, and the toner filming on the developing roller and the toner on a member such as a blade for thinning the toner Therefore, even when the developing device is used (stirred) for a long time, good and stable developability can be obtained, so that a high-quality image can be obtained. When this ratio exceeds 1.25, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle diameter may increase. is there.

  Here, the ratio of the volume average particle diameter to the volume average particle diameter and the number average particle diameter can be measured as follows using a particle size measuring device Multisizer III (manufactured by Beckman Coulter, Inc.). First, 0.1 to 5 ml of a surfactant such as an alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of an electrolyte aqueous solution such as an approximately 1% by mass sodium chloride aqueous solution. Next, about 2 to 20 mg of a measurement sample is added. The aqueous electrolyte solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and then the volume and number of toners are measured using a 100 μm aperture to determine the volume distribution and number distribution. calculate. From the obtained distribution, the volume average particle diameter and the number average particle diameter of the toner can be obtained.

  The penetration of toner is preferably 15 mm or more, and more preferably 20 mm to 30 mm. When the penetration is less than 15 mm, the heat resistant storage stability is deteriorated. Here, the penetration can be measured by a penetration test (JIS K2235-1991). Specifically, the toner is filled in a 50 ml glass container and left in a thermostat at 50 ° C. for 20 hours, and then the toner is cooled to room temperature and a penetration test is performed. In addition, it has shown that heat resistance preservability is excellent, so that the value of penetration is large.

  The toner of the present invention preferably has a low fixing minimum temperature and a high offset non-occurrence temperature from the viewpoint of achieving both low-temperature fixability and offset resistance. For this purpose, it is preferable that the lower limit fixing temperature is less than 140 ° C. and the temperature at which no offset occurs is 200 ° C. or more. Here, the lower limit fixing temperature is the lower limit of the fixing temperature at which the residual ratio of the image density after a copy test using an image forming apparatus and rubbing the obtained image with a pad is 70% or more. The offset non-occurrence temperature can be obtained by measuring a temperature at which no offset occurs when fixing is performed using an image forming apparatus adjusted to be developed with a predetermined amount of toner.

  The thermal characteristics of the toner, also called flow tester characteristics, are evaluated as a softening temperature, an outflow start temperature, a 1/2 method softening point, and the like. These thermal characteristics can be measured by an appropriately selected method, and can be measured using an elevated flow tester CFT500 type (manufactured by Shimadzu Corporation). The softening temperature of the toner is preferably 30 ° C. or higher, and more preferably 50 ° C. to 90 ° C. When the softening temperature is less than 30 ° C., the heat resistant storage stability may be deteriorated.

  The outflow start temperature of the toner of the present invention is preferably 60 ° C. or higher, and more preferably 80 ° C. to 120 ° C. When the outflow start temperature is less than 60 ° C., at least one of heat resistant storage stability and offset resistance may be deteriorated.

  The 1/2 method softening point of the toner of the present invention is preferably 90 ° C. or higher, and more preferably 100 ° C. to 170 ° C. When the 1/2 method softening point is less than 90 ° C., the offset resistance may be deteriorated.

  The glass transition temperature of the toner of the present invention is preferably 40 ° C to 70 ° C, and more preferably 45 ° C to 65 ° C. When the glass transition temperature is 40 ° C. or higher, the heat-resistant storage stability of the toner is good and does not deteriorate, and when it exceeds 70 ° C., the low-temperature fixability may not be sufficient. The glass transition temperature can be measured using a differential scanning calorimeter DSC-60 (manufactured by Shimadzu Corporation).

The density of an image formed using the toner of the present invention is preferably 1.40 or more, more preferably 1.45 or more, and even more preferably 1.50 or more. If the image density is less than 1.40, the image density may be low and high image quality may not be obtained. The image density was measured using a tandem color image forming apparatus (Imagio Neo 450, manufactured by Ricoh) with a fixing roller surface temperature of 160 ± 2 ° C. and a copy paper type 6200 (manufactured by Ricoh) as a recording material. A solid image having a developer adhesion amount of 0.35 ± 0.02 mg / cm ² was formed, and the image density at any five positions in the obtained solid image was measured using a spectrometer 938 spectrodensitometer (X-light). It can be obtained by measuring using a product manufactured by the company and calculating the average value.

  The color of the toner of the present invention can be appropriately selected according to the purpose, and can be one or more selected from the group consisting of black toner, cyan toner, magenta toner, and yellow toner. It can be obtained by appropriately selecting a colorant.

(Developer)
The developer of the present invention contains the toner of the present invention and may further contain other components appropriately selected such as a carrier. For this reason, it is excellent in transferability, chargeability, etc., and a high quality image can be formed stably. The developer may be a one-component developer or a two-component developer. However, when used in a high-speed printer or the like that supports an increase in information processing speed in recent years, the lifetime is shortened. A two-component developer is preferred because it improves.

  When the developer of the present invention is used as a one-component developer, even if the balance of the toner is performed, the fluctuation of the toner particle diameter is small, the filming of the toner on the developing roller, the blade for thinning the toner, etc. Therefore, good and stable developability and images can be obtained even with long-term stirring in the developing device.

  When the developer of the present invention is used as a two-component developer, there is little fluctuation in the particle diameter of the toner even if the toner balance is maintained over a long period of time, and good and stable developability even with long-term agitation in the developing device. An image is obtained. Although the said carrier can be suitably selected according to the objective, what has a core material and the resin layer which coat | covers a core material is preferable.

  The material of the core material can be appropriately selected from known materials, and examples thereof include manganese-strontium-based materials and manganese-magnesium-based materials of 50 emu / g to 90 emu / g. In order to ensure the image density, it is preferable to use a highly magnetized material such as iron powder of 100 emu / g or more and magnetite of 75 to 120 emu / g. In addition, it is preferable to use a low-magnetization material such as 30-80 emu / g of copper-zinc system because it can reduce the impact of the developer in a spiked state on the photoconductor and is advantageous for high image quality. . These may be used alone or in combination of two or more.

  The volume average particle diameter of the core material is preferably 10 μm to 150 μm, and more preferably 40 μm to 100 μm. When the volume average particle diameter is less than 10 μm, fine powder increases in the carrier, magnetization per particle may decrease and carrier scattering may occur, and when it exceeds 150 μm, the specific surface area decreases, Toner scattering may occur, and in the case of full color with many solid portions, reproduction of the solid portions may be deteriorated.

  The material of the resin layer covering the core material is not particularly limited and can be appropriately selected from known resins according to the purpose. For example, amino resins, polyvinyl resins, polystyrene resins, polyhalogens can be selected. Olefins, polyester resins, polycarbonate resins, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymers of vinylidene fluoride and acrylic monomers, vinylidene fluoride and vinyl fluoride Examples of the copolymer include fluoroterpolymers such as copolymers, copolymers of tetrafluoroethylene, vinylidene fluoride, and monomers having no fluoro group, and silicone resins. These may be used individually by 1 type and may use 2 or more types together.

  Specific examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Specific examples of the polyvinyl resin include acrylic resin, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyral. Specific examples of the polystyrene-based resin include polystyrene and styrene-acrylic copolymer. Specific examples of the polyhalogenated olefin include polyvinyl chloride. Specific examples of the polyester-based resin include polyethylene terephthalate and polybutylene terephthalate.

  The resin layer may contain conductive powder or the like as necessary. Specific examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. The average particle diameter of the conductive powder is preferably 1 μm or less. When the average particle diameter exceeds 1 μm, it may be difficult to control electric resistance.

  The resin layer is formed by preparing a coating solution by dissolving a silicone resin or the like in a solvent, and then coating and drying the coating solution on the surface of the core using a known coating method, followed by baking. Can do. As a coating method, a dip coating method, a spray method, a brush coating method, or the like can be used. There is no restriction | limiting in particular as said solvent, According to the objective, it can select suitably, Toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl cellosolve etc. are mentioned. The baking may be an external heating method or an internal heating method, a method using a fixed electric furnace, a fluid electric furnace, a rotary electric furnace, a burner furnace, a method using a microwave, or the like. Is mentioned.

  The content of the resin layer in the carrier is preferably 0.01% by mass to 5.0% by mass. When the content is less than 0.01% by mass, a uniform resin layer may not be formed on the surface of the core material. When the content exceeds 5.0% by mass, the resin layer is thick and the carrier Fusion may occur between them, and the uniformity of the carrier may decrease.

  The content of the carrier in the two-component developer is preferably 90% by mass to 98% by mass, and more preferably 93% by mass to 97% by mass.

  The developer of the present invention can be used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method.

  Next, an embodiment of an image forming apparatus using toner according to the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a diagram showing a schematic configuration of the image forming means of FIG. FIG. 4 is a diagram showing a schematic configuration of a process cartridge according to an embodiment of the present invention.

  The image forming apparatus shown in FIG. 2 is a tandem type color image forming apparatus. The image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

  The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15 and 16, and can rotate clockwise in FIG. A cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. An endless belt-shaped intermediate transfer member 50 stretched by the support roller 14 and the support roller 15 is provided with four image forming units 18Y, 18C, 18M, yellow, cyan, magenta, and black along the conveyance direction. An image forming unit 120 in which 18Ks face each other is arranged. An exposure device 21 is disposed in the vicinity of the image forming unit 120. The secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the image forming unit 120 is disposed.

  In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of support rollers 23 A and 23 B, and a recording sheet P that is a recording material conveyed on the secondary transfer belt 24 and an intermediate sheet. The transfer body 50 can be in contact with each other. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt and a pressure roller 27 that is pressed against the fixing belt 26. A reversing device 28 for reversing the recording paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25 in order to form images on both sides of the recording paper P.

  Next, formation of a full-color image (color copy) using the image forming unit 120 will be described. First, a document is set on a document table of an automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened, and a document is set on the contact glass 32 of the scanner 300. close up.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. When this happens, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33, and reflected light from the document surface is reflected by a mirror in the second traveling body 34. Further, the image is received by the reading sensor 36 through the imaging lens 35, and the original is read to obtain image information of black, yellow, magenta and cyan. Next, each image information is transmitted to each image forming unit 18Y, 18C, 18M, 18K in the image forming unit 120, and a visible image of each color of black, yellow, magenta, and cyan is formed.

  As shown in FIG. 3, the image forming units 18Y, 18C, 18M, and 18K are charged to uniformly charge the drum-shaped photoconductors 10Y, 10C, 10M, and 10K, and the photoconductors 10Y, 10C, 10M, and 10K, respectively. Each toner (black) is formed on the electrostatic latent image corresponding to each color formed by exposing each of the photoreceptors 10Y, 10C, 10M, and 10K based on image information corresponding to each color by the apparatus 20 and the exposure apparatus 21. Toners, yellow toners, magenta toners, and cyan toners) to form toner images, and developing units 61Y, 61C, 61M, and 61K that form visible images with the respective toners are transferred onto the intermediate transfer member 50. A primary transfer charger 62, a cleaning device 63, and a charge removal device 64 for forming a visible image of each color based on each image information. It is possible. Next, the visible images of the respective colors are sequentially transferred (primary transfer) from the respective photoreceptors 10Y, 10C, 10M, and 10K onto the intermediate transfer body 50 that is rotated by the support rollers 14, 15 and 16, and the respective color images. The visible image (toner image) is overlaid to form a composite transfer image (color toner image).

  On the other hand, in the paper feed table 200, as shown in FIG. 2, one of the paper feed rollers 142 is selectively rotated to feed the recording paper P from one of the paper feed cassettes 144 provided in the paper bank 143 in multiple stages. The paper is separated one by one by the separation roller 145 and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the paper feed roller 142 is rotated to feed out the recording paper on the manual feed tray 54, separated one by one by the separation roller 52, put into the manual paper feed path 53, and abutted against the registration roller 49 and stopped. The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove the paper dust of the recording paper P. Then, the registration roller 49 is rotated in time with the composite transfer image formed on the intermediate transfer member 50, and the recording paper P is sent between the intermediate transfer member 50 and the secondary transfer device 22 to perform secondary transfer. A color toner image is formed on the recording paper P by transferring (secondary transfer) the composite transfer image onto the recording paper by the device 22. The toner remaining on the intermediate transfer member 50 is removed by the cleaning device 17.

  The recording paper P on which the color image is formed is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the composite transfer image is heated and fixed on the recording paper P by the fixing device 25. Thereafter, the recording paper P is switched by the switching claw 55 and discharged by the discharge roller 56, and is stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and reversed by the reversing device 28 and led to the transfer position again. After an image is formed also on the back surface, the sheet is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  According to the image forming apparatus of the present invention, an image forming toner that has excellent low-temperature fixability and heat-resistant storage stability even at a high speed and is fixed only at a desired position on a recording medium without causing an offset phenomenon is used. Therefore, even if the process line speed is high, an abnormal image is not generated and the image can be fixed stably. For example, if the above-described tandem full-color image forming apparatus is used, a higher-quality image can be output at a higher speed. If the image forming apparatus of the present invention is used, it can be widely applied to electrophotographic application fields using electrophotography (for example, electrostatic copying machines, laser beam printers, etc.). In addition, since the above-described tandem image forming apparatus can transfer a plurality of toner images at a time, high-speed full-color printing is realized.

  Further, the image forming unit 120 as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.

  A process cartridge is an apparatus (part) that contains an electrostatic latent image bearing member (photosensitive member) and includes means selected from charging means, exposure means, developing means, transfer means, and cleaning means. It is. As a process cartridge according to the present invention, a drum-shaped photosensitive member as an electrostatic latent image carrier and at least a developing unit are integrally connected and detachably attached to an image forming apparatus for maintenance, inspection, and replacement. It is possible to work easily. A process cartridge according to an embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 4, the process cartridge of the present invention is charged with a drum-like photoreceptor 10 as an electrostatic latent image carrier and a charging roller 20 as a charging means for uniformly charging the surface of the photoreceptor 10. The developing means 61 for supplying toner to the electrostatic latent image formed by the exposure L from the exposure device 21 on the surface of the photosensitive member 10 to form a toner image, and the toner image formed on the surface of the photosensitive member 10 This is a process cartridge that is integrated with a cleaning unit 63 that removes toner remaining on the surface of the photoreceptor 10 after being transferred onto the recording material P by the transfer unit 65 and is detachable from the main body of the image forming apparatus. In this case, it is not necessary that the charging roller 20, the developing unit 61, and the cleaning unit 63 are all integrated with the photoconductor 10, and at least the developing unit 61 is integrated with the photoconductor 10. If it is enough. The developing means 61 contains the above-described image forming toner of the present invention. Therefore, the fixing means 25 (see FIG. 2) can stably fix only at a desired position on the recording paper P without causing an offset phenomenon due to an unfixed image, and can output a high-quality image. In addition, it is easy to store and transport and has excellent handling properties.

  In addition, the toner according to the present invention can be developed as a toner-filled container filled in a cylindrical or bag-like container to replenish the developing means loaded in the above-described image forming apparatus. It is possible to supply toner to the means.

Examples of the present invention will be described below, but the present invention is not limited to the following examples. However, Example 1 1, Example 1-5, actual施例2-1, Examples 2-2 are those both become reference example. In Examples, “part” and “%” in each example are based on mass, and “mol” means molar ratio.

  In the following examples, “mass average molecular weight of resin” and “volume average particle diameter of toner” were measured as follows.

(Measurement of mass average molecular weight of resin)
Gel permeation chromatography (GPC) measuring device: GPC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel SuperHZM-H
15cm triple (manufactured by Tosoh Corporation)
Temperature: 40 ° C
Solvent: THF
Flow rate: 0.35 ml / min
Sample: Injection of 0.1 ml of 0.15% sample Pretreatment of sample: Toner was dissolved in tetrahydrofuran THF (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.) at 0.15% and then filtered through a 0.2 μm filter. The filtrate is used as a sample. 100 μl of the THF sample solution is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts.

  As a standard polystyrene sample for preparing a calibration curve, Showd STANDARD Std. No. S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, S-0.580, and toluene were used. An RI (refractive index) detector was used as the detector.

(Average toner particle size)
The volume average particle diameter (Dv), number average particle diameter (Dn), and Dv / Dn of the toner are measured with a particle size measuring device (“Multisizer III”, manufactured by Beckman Coulter, Inc.) with an aperture diameter of 100 μm, and analyzed software The analysis was performed with (Beckman Coulter Multisizer 3 Version 3.51). Specifically, 0.5 ml of 10% surfactant (alkylbenzene sulfonate Neogen SC-A; manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml glass beaker, and 0.5 g of each toner is added. The mixture was stirred, and then 80 ml of ion exchange water was added. The obtained dispersion was subjected to dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II; manufactured by Honda Electronics Co., Ltd.). The dispersion was measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution. In the measurement, the toner sample dispersion was dropped so that the concentration indicated by the apparatus was 8 ± 2%. In this measurement method, it is important that the concentration is 8 ± 2% from the viewpoint of the reproducibility of the particle size. Within this concentration range, no error occurs in the particle size.

(Measurement of glass transition temperature and melting point)
Here, the glass transition point (Tg) and the melting point in the present invention are specifically determined by the following procedure. Using Shimadzu TA-60WS and DSC-60 as measuring devices, the measurement was performed under the following measurement conditions.

Measurement conditions Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50ml / min)
Temperature conditions Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C

  The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation.

  The analysis method of the glass transition temperature specifies the range of ± 5 ° C around the point showing the maximum peak on the lowest temperature side of the DrDSC curve which is the DSC differential curve of the second temperature rise, and the peak analysis function of the analysis software To determine the peak temperature. Next, the maximum endothermic temperature of the DSC curve is determined using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the Tg of the toner.

  The melting point analysis method uses the peak analysis function of the analysis software, specifying a range of ± 5 ° C, centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve, which is the DSC differential curve of the second temperature increase. To obtain the peak temperature. The temperature shown here corresponds to the melting point.

  The glass transition point and melting point are determined by the glass transition point when the DSC curve does not return to the exothermic direction in the DSC curve, and the melting point when the DSC curve after endotherm returns to the DSC curve (baseline) before endotherm. Can be determined.

(Measurement of mass loss at 165 ° C.)
The measurement of the mass loss at 165 ° C. in the present invention is specifically determined by the following procedure. Shimadzu TA-60WS and DTG-60 were used as measurement devices, and measurement was performed under the following measurement conditions.

Measurement conditions Sample container: Aluminum sample pan Sample amount: 5 mg
Reference: Aluminum sample pan (sample pan only)
Atmosphere: Nitrogen (flow rate 50ml / min)
Temperature conditions Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 165 ° C
Retention time: 60 minutes

  The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The analysis method of mass decrease at 165 ° C. is calculated by the following equation when A is the mass at 165 ° C. and 0 minutes, and B is the mass B after being held for 60 minutes.

  Mass reduction at 165 ° C. = (A−B) / A × 100

[Example 1]
(Toner material solution preparation process)
-Synthesis of unmodified polyester (low molecular weight polyester)-
229 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 528 parts by mass of bisphenol A propion oxide 3-mole adduct, 207 parts by mass of terephthalic acid, 45 parts by mass of adipic acid in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe And 2 parts by mass of dibutyltin oxide were added and reacted at 230 ° C. for 7 hours under normal pressure. Next, after reacting the reaction solution under a reduced pressure of 10 to 15 mmHg for 5 hours, 43 parts by mass of trimellitic anhydride was added to the reaction vessel, and the reaction was performed at 185 ° C. for 2 hours under normal pressure. A modified polyester was synthesized.

  The obtained unmodified polyester had a number average molecular weight (Mn) of 2,600, a weight average molecular weight (Mw) of 6,600, a glass transition temperature (Tg) of 44 ° C., and an acid value of 23 mgKOH / g.

-Preparation of masterbatch (MB-1)-
1,200 parts by mass of water, 540 parts by mass of carbon black (“Printex35”; manufactured by Degussa, DBP oil absorption = 42 ml / 100 g, pH = 9.5) as the colorant, and 1210 parts by mass of the unmodified polyester were added to Henschel. Mixing was performed using a mixer (Mitsui Mining Co., Ltd.). The mixture was kneaded at 160 ° C. for 40 minutes with two rolls, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare a master batch (MB-1).

(Production Example 1)
--Synthesis of wax dispersant--
In an autoclave reaction vessel equipped with a thermometer and a stirrer, 600 parts of xylene and 300 parts of low molecular weight polyethylene (Sanwa Kasei Kogyo Co., Ltd. Sun Wax LEL-400: softening point 128 ° C.) are sufficiently dissolved, and after nitrogen replacement , 2310 parts of styrene, 270 parts of acrylonitrile, 150 parts of butyl acrylate, 78 parts of di-t-butylperoxyhexahydroterephthalate and 455 parts of xylene were added dropwise at 175 ° C. over 3 hours to polymerize, Hold at temperature for 30 minutes. Next, the solvent was removed to obtain a wax dispersant.

-Preparation of wax dispersion (1-1)-
In a reaction vessel in which a stir bar and a thermometer are set, 378 parts by mass of the unmodified polyester, 110 parts by mass of paraffin wax (manufactured by Victory Wax Toyo Adre / melting point 52 ° C., melt viscosity at 140 ° C .: 12 mPa · s), 49.5 parts by weight of a wax dispersant and 947 parts by weight of ethyl acetate were added, the temperature was raised to 85 ° C. with stirring, the temperature was maintained at 85 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour to obtain a wax dispersion ( 1-1) was obtained.

(Example 1-1)
-Preparation of organic solvent phase-
The wax dispersion (1-1) is charged into 500 parts by mass of the master batch (MB-1) and 500 parts by mass of ethyl acetate at a mass corresponding to 4.0 parts of the wax in the toner and mixed for 2 hours. Thus, a raw material solution was obtained. 1324 parts by mass of the obtained raw material solution was transferred to a reaction vessel, and using a bead mill (“Ultra Visco Mill”; manufactured by Imex Co., Ltd.), the liquid feeding speed was 1 kg / hr, the disk peripheral speed was 7 m / sec, and 0.5 mm zirconia. The carbon black and the wax were dispersed by three passes under the condition of 80% by volume of beads. Subsequently, 1325 parts by mass of a 65% by mass ethyl acetate solution of the unmodified polyester was added to the dispersion. One pass was performed in a bead mill under the same conditions as described above, and the mixture was dispersed to prepare an organic solvent phase. The solid content concentration (measurement condition: 130 ° C., by heating for 30 minutes) of the obtained organic solvent phase was 50% by mass.

-Synthesis of prepolymer-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 82 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 23 Part and 2 parts of dibutyltin oxide were added, reacted at 235 ° C. under normal pressure for 7 hours, and further reacted at reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1-1]. [Intermediate polyester 1-1] had a number average molecular weight of 2300, a weight average molecular weight of 9750, a peak molecular weight of 3100, a Tg of 53 ° C., an acid value of 0.7 mgKOH / g, and a hydroxyl value of 50 mgKOH / g.

  Next, 411 parts of [Intermediate polyester 1-1], 87 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. [Prepolymer 1-1] was obtained. [Prepolymer 1-1] had a free isocyanate mass% of 1.42% by mass.

-Synthesis of ketimine (active hydrogen group-containing compound)-
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to synthesize a ketimine compound (active hydrogen group-containing compound). The amine value of the obtained ketimine compound (active hydrogen machine-containing compound) was 418.

-Preparation of toner material liquid-
Into a reaction vessel, 748 parts by mass of the organic solvent phase, 114 parts by mass of the prepolymer, and 2.8 parts by mass of the ketimine compound are charged, and 7.3 m / m using a TK type homomixer (manufactured by Special Machine Industries). A toner material solution was prepared by mixing for 1 minute at s.

-Preparation of organic resin fine particle dispersion-
In a reaction vessel in which a stir bar and a thermometer are set, 683 parts by mass of water, 22 parts by weight of sodium salt of ethylene oxide methacrylate adduct sulfate ("Eleminol RS-30"; manufactured by Sanyo Chemical Industries), 78 parts by mass of styrene , 78 parts by weight of methacrylic acid, 120 parts by weight of butyl acrylate, and 1 part by weight of ammonium persulfate were added and stirred at 450 rpm for 15 minutes to obtain a white emulsion. The emulsion was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Next, 30 parts by mass of a 1% by mass ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours. Vinyl resin particles (styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt) (Copolymer) aqueous dispersion (organic resin fine particle dispersion) was prepared.

  It was 54 nm when the volume average particle diameter (Dv) of the organic resin fine particles contained in the obtained organic resin fine particle dispersion was measured by a particle size distribution measuring device (“nanotrac UPA-150EX”; manufactured by Nikkiso Co., Ltd.). Moreover, when a part of the organic resin fine particle dispersion was dried to isolate the resin, and the glass transition temperature (Tg) of the resin was measured, it was 48 ° C. and the weight average molecular weight (Mw) was measured. It was 440,000.

-Preparation of aqueous medium phase-
990 parts by weight of water, 37 parts by weight of a 48.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate (“Eleminol MON-7”; manufactured by Sanyo Chemical Industries), 15 parts of the organic resin fine particle dispersion, and 91 parts by weight of ethyl acetate Were mixed and stirred to obtain a milky white liquid (aqueous medium phase).

-Measurement of critical micelle concentration-
The critical micelle concentration of the surfactant was measured by the following method. Using a surface tension meter Sigma (manufactured by KSV Instruments), analysis was performed using an analysis program in the Sigma system. Surfactant was dropped 0.01% by mass with respect to the aqueous medium, and the interfacial tension after stirring and standing was measured. From the obtained surface tension curve, the surfactant concentration at which the interfacial tension did not decrease even when the surfactant was dropped was calculated as the critical micelle concentration. When the critical micelle concentration of sodium dodecyl diphenyl ether disulfonate with respect to the aqueous medium of Example 1-1 was measured with a surface tension meter Sigma, it was 0.05% by mass with respect to the mass of the aqueous medium.

(Toner granulation process)
-Emulsification or dispersion-
1210 parts by mass of the aqueous medium phase is added to the toner material liquid, and mixed for 20 minutes at a peripheral speed of 18 m / s with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). An emulsified slurry) was prepared.

-Removal of organic solvents-
In a reaction vessel equipped with a stirrer and a thermometer, the emulsified slurry after the emulsification / dispersion step (after particle size control) is charged, and after removing the solvent at 30 ° C. for 7 hours, aging is performed at 45 ° C. for 5 hours. A dispersion slurry was obtained.

-Cleaning and drying-
After 100 parts by mass of the dispersion slurry was filtered under reduced pressure, 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at a rotation speed of 10.0 m / s), and then filtered. 100 parts by mass of ion-exchanged water was added to the obtained filter cake, mixed with a TK homomixer (at a rotation speed of 12.0 m / s for 10 minutes), and then filtered under reduced pressure. To the obtained filter cake, 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added, mixed with a TK homomixer (at a rotation speed of 11.0 m / s for 10 minutes) and then filtered. To the obtained filter cake, 310 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (10 minutes at a rotation speed of 11.0 m / s), and then filtered twice to obtain a final filter cake. It was.

―Surface treatment process―
To the filter cake obtained by the above washing, 300 parts by mass of ion-exchanged water was added and stirred and mixed with a TK homomixer at a rotation speed of 7,000 rpm to prepare a toner dispersion. The toner dispersion was heated and allowed to cool for 40 minutes after the temperature of the toner dispersion reached T1 = 60 ° C. After cooling, the electrical conductivity of the toner dispersion was measured. The surfactant concentration of the toner dispersion was calculated from a calibration curve for the surfactant concentration prepared in advance. From this value, the surfactant concentration was 0.05 wt%. Next, filtration was performed.

―Dry―
The obtained final filter cake was dried with a circulating dryer at 45 ° C. for 48 hours, and sieved with a mesh of 75 μm to obtain toner base particles of Example 1-1.

-External additive treatment-
For 100 parts by mass of the toner base particles obtained in Example 1-1, 1.4 parts by mass of hydrophobic silica as an external additive and 0.7 parts by mass of hydrophobic titanium oxide were added to a Henschel mixer (Mitsui Mining Co., Ltd.). ) And sieved with a mesh of 35 μm to produce the toner of Example 1-1. FIG. 1 is a cross-sectional TEM photograph (magnification: 100,000 times) of the toner of Example 1-1.
About the obtained toner, the volume average particle diameter (Dv), the number average particle diameter (Dn), and the particle size distribution (volume average particle diameter (Dv) / number average particle diameter (Dn)) were measured by the method described above.

(Example 1-2)
Except for changing the wax of Example 1-1 to microcrystalline wax BE SQUARE 185 Wax (manufactured by Toyo Adre, melting point 60 ° C., melt viscosity at 140 ° C .: 9 mPa · s), the same procedure as in Example 1-1 was performed. Toner was created.

(Example 1-3)
Except for changing the wax of Example 1-1 to microcrystalline wax BE SQUARE 195 Wax (manufactured by Toyo Adre, melting point 77 ° C., melt viscosity at 140 ° C .: 10 mPa · s), the same procedure as in Example 1-1 was performed. Toner was created.

(Example 1-4)
Example except that the wax of Example 1-1 was changed to BE SQUARE 185 Wax (manufactured by Toyo Adre), the amount of wax charged was changed to 1.5 parts by mass, and the toner dispersion temperature was changed to 70 ° C. A toner was prepared in the same manner as in 1-1.

(Example 1-6)
A toner was prepared in the same manner as in Example 1-2 except that the toner dispersion temperature T1 = 60 ° C. in the surface treatment step in Example 1-2 was changed to 73 ° C.

(Comparative Example 1-1)
A toner was prepared in the same manner as in Example 1-1, except that the wax of Example 1-1 was changed to paraffin HNP-10 (manufactured by Nippon Seiwa Co., Ltd., melting point 75 ° C., melt viscosity at 140 ° C .: 4 mPa · s). Created.

(Comparative Example 1-2)
A toner was prepared in the same manner as in Example 1-1, except that the wax of Example 1-1 was changed to paraffin LUVAX 2191 (manufactured by Nippon Seiwa Co., Ltd., melting point 83 ° C., melt viscosity at 140 ° C .: 19 mPa · s). .

(Comparative Example 1-3)
Except for changing the wax dispersion (1-1) of Example 1-1 to the following wax dispersion (1-3) and changing the amount of the charged wax to 10 parts by mass, the same procedure as in Example 1-1 was performed. The toner was created.

--Synthesis of wax dispersant--
In an autoclave reaction vessel equipped with a thermometer and a stirrer, 600 parts of xylene and 300 parts of low molecular weight polyethylene (Sanwa Kasei Kogyo Co., Ltd. Sun Wax LEL-400: softening point 128 ° C.) are sufficiently dissolved, and after nitrogen replacement , 2310 parts of styrene, 270 parts of acrylonitrile, 150 parts of butyl acrylate, 78 parts of di-t-butylperoxyhexahydroterephthalate and 455 parts of xylene were added dropwise at 175 ° C. over 3 hours to polymerize, Hold at temperature for 30 minutes. Next, the solvent was removed to obtain a wax dispersant.
-Preparation of wax dispersion (1-3)-
In a reaction vessel in which a stir bar and a thermometer were set, 163.5 parts by mass of the unmodified polyester, 275 parts by mass of wax (Victory Wax Toyo Adle Co., Ltd./melting point 52 ° C., melt viscosity at 140 ° C .: 12 mPa · s) Then, 123.75 parts by mass of a wax dispersant and 947 parts by mass of ethyl acetate were added, the temperature was raised to 80 ° C. with stirring, the temperature was maintained at 80 ° C. for 4 hours, and then cooled to 30 ° C. over 1 hour to obtain a wax dispersion. (1-3) was obtained.

(Comparative Example 1-4)
A toner was prepared in the same manner as in Example 1-1 except that the dispersion temperature T1 = 60 ° C. in the surface treatment step of Example 1-2 was changed to 40 ° C.

(Comparative Example 1-5)
A toner was prepared in the same manner as in Example 1-1 except that the dispersion temperature T1 = 60 ° C. in the surface treatment process of Example 1-2 was changed to 95 ° C.

  Table 1 shows the characteristics, charge amounts, and toner dispersion temperatures of the waxes of (Example 1-1) to (Example 1-6) and (Comparative Example 1-1) to (Comparative Example 1-5). It is. Moreover, the melt viscosity at 140 ° C. of the used wax is as shown in Table 2.

  Using the toners prepared in the above (Example 1-1) to (Example 1-6) and (Comparative Example 1-1) to (Comparative Example 1-5), toner fixing characteristics, filming resistance, Evaluation was made on the backside of the printing paper, transfer rate, transfer unevenness, and fog. The results are shown in Table 3. The evaluation of toner fixing characteristics, anti-filming, printing paper backside stain, transfer rate, transfer unevenness, and fogging was performed under the following conditions.

(Fixing characteristics)
The fixing property of the toner was evaluated as follows. A similar evaluation was performed using a modified machine equipped with a belt heating and fixing device shown in FIG. 5 on RICOH Imagio Neo 450. A belt heat fixing device 25 shown in FIG. 5 has a heating roller R3 having a heating source H1 at the core, an endless fixing belt 26 stretched around the fixing roller R1, and the fixing roller R1 via the fixing belt 26. And a pressure roller 27 that is pressed by a pressure spring P1. The pressure roller 27 has a heating source H2 at the core, and can heat and press the toner on the recording material P by heating the recording material P guided by the guide G. The fixing belt 26 is applied with a predetermined tension by a heating roller R3 pulled by a spring P2, and can be slidably contacted with the outer periphery of a cleaning roller R4 for cleaning the surface of the fixing belt 26. . Incidentally, in the present embodiment, the base of the fixing belt 26 is a belt having a three-layer structure of 100 μm of polyimide, an intermediate elastic layer of 100 μm of silicon rubber, and a surface offset preventing layer of 15 μm of PFA. Further, the outer peripheral layer of the fixing roller R1 is formed of a silicon foam, the metal cylinder at the core of the pressure roller 27 is SUS, and the thickness is 1 mm. The offset prevention layer of the outermost peripheral layer of the pressure roller 27 is a PFA tube. + Silicon rubber having a thickness of 2 mm, a heating roller 27 having an aluminum intermediate layer having a thickness of 2 mm, and a surface pressure of 1 × 10 5 Pa was used.

The criteria for each characteristic evaluation are as follows.
(1) Low temperature fixability (five-level evaluation)
◎; Less than 120 ° C, ◯; Less than 120 to 130 ° C, □; Less than 130 to 140 ° C, Δ; Less than 140 to 150 ° C, x: 150 ° C or more (2) Hot offset property (five-step evaluation)
A: 201 ° C. or higher, ○: 200-191 ° C., □: 190-181 ° C., Δ: 180-171 ° C., x: 170 ° C. or lower

(Film resistance)
Using a color electrophotographic apparatus (“IPSiO Color 8100”; manufactured by Ricoh Co., Ltd.), visually observe the occurrence of toner filming on the developing roller or the photoconductor when copying 50,000 sheets. Evaluation was made based on the following criteria.

〔Evaluation criteria〕
◎: Filming is not observed ○: Line-shaped filming is hardly observed Δ: Line-shaped filming is partially observed ×: Filming is generally observed

(Stain on the back of printing paper)
A solid black image was created using imgio Neo 450 manufactured by Ricoh Co., Ltd., and a solid white image was output after outputting 1 million sheets of images, and the back stain of the printing paper was evaluated according to the following evaluation criteria.
◎: No dirt on the back ○: Between ◎ and □ □: Some dirt is seen △: Between □ and ×
×: Recognized as clearly soiled

(Transfer efficiency (%)) (Transfer rate)
A solid pattern with an A4 size and 0.6 mg / cm ² toner adhesion for each developer, using an evaluation machine that was modified from Fuji Xerox's DocuColor 8000 Digital Press and tuned so that the linear speed and transfer time could be adjusted. Was run as a test image. After outputting 100,000 test images and 1 million test images, the transfer efficiency in the primary transfer was determined by the following formula (3), and the transfer efficiency in the secondary transfer was determined by the following formula (4). The evaluation criteria are as follows.
Primary transfer efficiency = (amount of toner transferred onto intermediate transfer member) / (amount of toner transferred onto electrophotographic photosensitive member) × 100 (3)
Secondary transfer efficiency = ((amount of toner transferred onto intermediate transfer member−amount of residual toner on intermediate transfer member) / amount of toner transferred onto intermediate transfer member) × 100 (4)

Evaluation criteria are
◎ ... 90% or more ○ ... 85% or more and less than 90% △ ... 80% or more and less than 85% × ... less than 80%

(Transfer unevenness)
A solid black image was formed using a tandem color electrophotographic apparatus imagio Neo 450 (manufactured by Ricoh Co., Ltd.), and the obtained image was visually observed for the presence or absence of transfer unevenness to evaluate transfer unevenness. It should be noted that there is no transfer unevenness and a very good level (◎), there is no transfer unevenness and there is no problem in actual use (○), there is a little transfer unevenness, but actual use The determination was made with (Δ) indicating a possible level and (×) indicating that there was a transfer unevenness and a practically problematic level.

(Cover)
Using a tandem color electrophotographic apparatus imagio Neo 450 (manufactured by Ricoh) having a cleaning blade and a charging roller in contact with the photoreceptor, a black solid and a white solid at intervals of 1 cm in a direction perpendicular to the rotation direction of the developing sleeve. After outputting 100,000 A4 horizontal charts (image pattern A), a blank image was output and the presence or absence of fogging was visually evaluated. It should be noted that a very good level with no fogging (◎), a level with almost no fogging and no problem in actual use (○), a level with a little fogging but practically usable. A thing with a ((triangle | delta)) and a fogging and the level which has a problem practically was determined as (x).

As is apparent from the results of Tables 1 and 3, in the case of using the wax having a large mass loss amount at 165 ° C. shown in Comparative Examples 1-1 and 1-2 at 12% by mass and 14% by mass, respectively, Poor smearing and printing paper backside dirt characteristics. In addition, the wax shown in Comparative Example 1-2 has a characteristic that the lower limit of the fixing characteristic is poor because the melting point exceeds 83 ° C. and 78 ° C. In addition, when the amount of the wax shown in Comparative Example 1-3 is 10 parts by mass and the wax content is 9.2% by mass, the filming resistance and the stain on the back side of the printing paper are poor. Moreover, when exceeding Sbet / SF = 3.7 m ² / g and Sbet / SF = 3.6 m ² / g shown in Comparative Example 1-4, not only the lower limit of the fixing characteristics is bad, but also filming resistance and The dirt on the back of printing paper is poor. Further, in the case of Sbet / SF = 0.9 m ² / g and Sbet / SF = less than 1.0 m ² / g shown in Comparative Example 1-5, not only the filming resistance and the printing paper backside stain characteristics are poor, It is apparent that the transfer rate and transfer unevenness characteristics are also deteriorated.

  On the other hand, in Examples 1-1 to 1-6 according to the present invention, the melting point, the mass reduction amount at 165 ° C., the charge amount, and the toner dispersion temperature are within the predetermined ranges. Therefore, it is clear that the fixing characteristics, filming resistance, printing paper backside dirt characteristics, transfer rate and fogging also show good characteristics.

[Example 2]
Next, the toner dispersion liquid temperature (T1) is set to 60 ° C. and the holding time is changed, based on Example 2-1, Example 2-2, Comparative Example 2-1, and Comparative Example 2-2. explain.

(Example 2-1)
<Toner material liquid preparation process>
-Synthesis of unmodified polyester (low molecular weight polyester)-
229 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 529 parts by mass of bisphenol A propion oxide 3-mole adduct, 209 parts by mass of terephthalic acid, 45 parts by mass of adipic acid And 2 parts by mass of dibutyltin oxide were added and reacted at 230 ° C. for 7 hours under normal pressure. Next, the reaction solution was reacted for 5 hours under a reduced pressure of 10 to 15 mmHg, and then 43 parts by weight of trimellitic anhydride was added to the reaction vessel and reacted at 180 ° C. for 2 hours under normal pressure. A modified polyester was synthesized. The obtained unmodified polyester had a number average molecular weight (Mn) of 2,600, a weight average molecular weight (Mw) of 6,700, a glass transition temperature (Tg) of 44 ° C., and an acid value of 26 mgKOH / g.

-Preparation of masterbatch (MB-2)-
1200 parts by mass of water, 540 parts by mass of carbon black (“Printex35”; manufactured by Degussa, DBP oil absorption = 42 ml / 100 g, pH = 9.5) as the colorant, and 1200 parts by mass of the unmodified polyester were added to Henschel. Mixing was performed using a mixer (Mitsui Mining Co., Ltd.). The mixture was kneaded with a two-roller at 170 ° C. for 30 minutes, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron) to prepare a master batch (MB-2).

(Production Example 1)
-Preparation of wax dispersion (2-1)-
In a reaction vessel in which a stir bar and a thermometer were set, 378 parts by mass of the unmodified polyester, 110 parts by mass of wax (produced by Victory Wax Toyo Adre Co., Ltd./melting point 52 ° C.), 49.5 parts by mass of a wax dispersant, and ethyl acetate 947 parts by mass were charged, the temperature was raised to 80 ° C. with stirring, the temperature was maintained at 80 ° C. for 7 hours, and then cooled to 30 ° C. over 2 hours to obtain a wax dispersion (2-1).
(Example 2-1)
-Preparation of organic solvent phase-
The wax dispersion (2-1) is charged in a mass corresponding to 4.0 parts of the pigment amount in the toner, and 500 parts by mass of the master batch (MB-2) and 500 parts by mass of ethyl acetate are charged and mixed for 2 hours. A raw material solution was obtained.
1325 parts by mass of the resulting raw material solution was transferred to a reaction vessel, and using a bead mill (“Ultra Visco Mill”; manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 8 m / sec, and 0.5 mm zirconia. The carbon black and the wax were dispersed by three passes under the condition of 80% by volume of beads. Next, 1323 parts by mass of a 65% by mass ethyl acetate solution of the unmodified polyester was added to the dispersion. One pass was performed in a bead mill under the same conditions as described above, and the mixture was dispersed to prepare an organic solvent phase.
The solid content concentration (measurement condition: 130 ° C., by heating for 30 minutes) of the obtained organic solvent phase was 50% by mass.

-Synthesis of prepolymer-
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction pipe, 681 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 83 parts by mass of bisphenol A propylene oxide 2-mole adduct, 283 parts by mass of terephthalic acid, 20 parts by mass of merit acid and 2 parts by mass of dibutyltin oxide were added, reacted at 230 ° C. for 9 hours under normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 2-1]. [Intermediate Polyester 2-1] had a number average molecular weight of 2300, a weight average molecular weight of 9800, a peak molecular weight of 3300, a Tg of 56 ° C., an acid value of 0.4 mgKOH / g, and a hydroxyl value of 49 mgKOH / g.

  Next, 411 parts of [Intermediate polyester 2-1], 84 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 6 hours. [Prepolymer 2-1] was obtained. [Prepolymer 2-1] had a free isocyanate mass% of 1.43%.

-Synthesis of ketimine (active hydrogen group-containing compound)-
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts by mass of isophoronediamine and 77 parts by mass of methyl ethyl ketone were charged and reacted at 50 ° C. for 7 hours to synthesize a ketimine compound (active hydrogen group-containing compound). The amine value of the obtained ketimine compound (active hydrogen machine-containing compound) was 419.

-Preparation of toner material liquid-
Into a reaction vessel, 749 parts by mass of the organic solvent phase, 117 parts by mass of the prepolymer, and 2.3 parts by mass of the ketimine compound were charged, and 8.5 m / m using a TK type homomixer (manufactured by Special Machine Industries). A toner material solution was prepared by mixing for 1 minute at s.

-Preparation of organic resin fine particle dispersion-
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts by weight of water, 20 parts by weight of sodium salt of ethylene oxide methacrylate adduct sulfate ("Eleminol RS-30"; manufactured by Sanyo Chemical Industries), 75 parts by weight of styrene Then, 73 parts by mass of methacrylic acid, 121 parts by mass of butyl acrylate, and 1 part by mass of ammonium persulfate were charged and stirred at 400 rpm for 25 minutes to obtain a white emulsion. The emulsion was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Next, 30 parts by mass of a 1% by mass ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 8 hours. Vinyl resin particles (styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt) (Copolymer) aqueous dispersion (organic resin fine particle dispersion) was prepared.

  It was 55 nm when the volume average particle diameter (Dv) of the organic resin fine particles contained in the obtained organic resin fine particle dispersion was measured by a particle size distribution measuring device (“nanotrac UPA-150EX”; manufactured by Nikkiso Co., Ltd.). Moreover, when a part of the organic resin fine particle dispersion was dried to isolate the resin, and the glass transition temperature (Tg) of the resin was measured, it was 49 ° C. and the weight average molecular weight (Mw) was measured. It was 452,000.

-Preparation of aqueous medium phase-
990 parts by weight of water, 38 parts by weight of a 46.5% by weight aqueous solution of sodium dodecyl diphenyl ether disulfonate (“Eleminol MON-7”; manufactured by Sanyo Chemical Industries), 15 parts of the organic resin fine particle dispersion, and 90 parts by weight of ethyl acetate The mixture was stirred to obtain a milky white liquid (aqueous medium phase).

(Toner granulation process)
-Emulsification or dispersion-
1200 parts by weight of the aqueous medium phase is added to the toner material liquid, and mixed for 40 minutes at a peripheral speed of 15 m / s with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). An emulsified slurry) was prepared.

-Removal of organic solvents-
The emulsified slurry after controlling the particle diameter was charged into a reaction vessel equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was performed at 45 ° C. for 5 hours to obtain a dispersed slurry.

-Cleaning and drying-
After 100 parts by mass of the dispersion slurry was filtered under reduced pressure, 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (30 minutes at a rotation speed of 10.0 m / s), and then filtered. 100 parts by mass of ion-exchanged water was added to the obtained filter cake, mixed with a TK homomixer (at a rotation speed of 10.0 m / s for 10 minutes), and then filtered under reduced pressure. To the obtained filter cake, 100 parts by mass of a 10% by mass aqueous sodium hydroxide solution was added, mixed with a TK homomixer (10 minutes at a rotation speed of 10.0 m / s), and then filtered. To the obtained filter cake, 300 parts by mass of ion-exchanged water was added, mixed with a TK homomixer (30 minutes at a rotation speed of 10.0 m / s), and then filtered twice to obtain a final filter cake. It was.

―Surface treatment process―
To the filter cake obtained by the above washing, 300 parts by mass of ion-exchanged water was added and stirred and mixed with a TK homomixer at a rotation speed of 8,000 rpm to prepare a toner dispersion. The toner dispersion was heated and allowed to cool for 5 minutes after the temperature of the toner dispersion reached T1 = 55 ° C. After cooling, the electrical conductivity of the toner dispersion was measured. The surfactant concentration of the toner dispersion was calculated from a calibration curve for the surfactant concentration prepared in advance. From that value, the surfactant concentration was 0.04 wt%. Next, filtration was performed.

―Dry―
The obtained final filter cake was dried with a circulating dryer at 45 ° C. for 48 hours, and sieved with a mesh of 75 μm to obtain toner base particles of Example 2-1.

-External additive treatment-
For 100 parts by mass of the toner base particles of Example 2-1, 1.8 parts by mass of hydrophobic silica as an external additive and 0.7 parts by mass of hydrophobic titanium oxide were added to a Henschel mixer (Mitsui Mining Co., Ltd.). ), And sieved with a mesh of 35 μm to produce the toner of Example 2-1. The obtained toner was measured for volume average particle size (Dv), number average particle size (Dn), and particle size distribution (volume average particle size (Dv) / number average particle size (Dn)).

(Example 2-2)
A toner was prepared in the same manner as in Example 2-1, except that the toner dispersion temperature holding time in the surface treatment step of Example 2-1 was changed to 55 minutes.

(Comparative Example 2-1)
A toner was prepared in the same manner as in Example 2-1, except that the toner dispersion temperature holding time in the surface treatment step of Example 2-1 was changed to 30 seconds.

(Comparative Example 2-2)
A toner was prepared in the same manner as in Example 2-1, except that the heating time in the surface smoothing step of Example 2-1 was changed to 70 minutes.

  Table 4 shows toner dispersion temperature holding times in the surface treatment steps in Example 2-1, Example 2-2, Comparative Example 2-1, and Comparative Example 2-2.

  About the toner obtained in Example 2-1, Example 2-2, Comparative Example 2-1, and Comparative Example 2-2, it is the same as in the case of (Example 1-1) to (Example 1-6). Toner BET specific surface area (Sbet), average circularity (SF), Sbet / SF, toner particle size, wax amount, fixing characteristics (lower limit, hot offset property), anti-filming, printing paper backside dirt characteristics, transfer rate Then, transfer unevenness and fog were measured and evaluated. The results are shown in Table 5.

  In the toner of Example 2-1, since the bleed-out of the wax is suppressed, the contamination of other members by the wax is reduced. From this, filming resistance, stains on the back of printing paper, transfer rate, transfer unevenness, and fog are all superior to other toners. On the other hand, since the toner of Comparative Example 2-1 has a short heating time, the toner surface is not sufficiently smoothed, and the transfer rate, transfer unevenness, and fog are poor. In addition, although the toner of Comparative Example 2-2 has been smoothed, contamination to other members, which is considered to be caused by wax bleed-out, is observed, filming resistance, printing paper backside contamination, transfer rate, transfer Unevenness and fog are getting worse.

10, 10Y, 10C, 10M, 10K Photoconductor 18Y, 18C, 18M, 18K Image forming unit 20 Charging device 21 Exposure device 22 Secondary transfer device 25 Fixing device 26 Fixing belt 27 Pressure roller 49 Registration roller 50 Intermediate transfer member 61 , 61Y, 61C, 61M, 61K Developing means 62 Primary transfer device 63 Cleaning device R1 Fixing roller R3 Heating roller

Japanese Patent Application Laid-Open No. 07-209952 JP 2000-077551 Japanese Patent No. 3640918 Japanese Patent Laid-Open No. 06-250439 JP 2001-0666820 A Japanese Patent No. 3692929 Japanese Patent No. 3376019 JP-A-2005-331925 JP 2006-195040 A

Claims (12)

In a toner containing at least a binder, a colorant, and a microcrystalline wax that forms a molecular chain only with C—H bonds and C—C bonds,
The weight loss of the wax at 165 ° C. is 10% by mass or less,
The ratio of the total amount of wax in the toner particles measured by the DSC method in the toner is 1.3% by mass to 3.7% by mass ,
A ratio Sbet / SF between the BET specific surface area (Sbet) of the toner and the average circularity (SF) of the toner is in a range of 1.0 m ² / g or more and less than 3.6 m ² / g. toner. The toner according to claim 1.
A toner having a melting point of 50 to 90 ° C. The toner according to claim 1 or 2,
A toner having a melt viscosity at 140 ° C. of 6 to 15 mPa · S of the wax in the toner. The toner according to any one of claims 1 to 3,
A toner wherein the weight loss of the wax at 165 ° C. is 3% by mass or less. In the toner according to any one of claims 1 to 4,
The toner, wherein the toner contains 40% by mass to 80% by mass of a wax dispersant with respect to the wax. The toner according to any one of claims 1 to 5,
The toner is a toner comprising a binder resin or a precursor of the binder resin as a binder component. The toner according to claim 6.
The binder resin precursor is a polymer having reactivity to the active hydrogen group-containing compound and the active hydrogen group, and in the step of emulsifying or dispersing in an aqueous medium containing a surfactant, the active hydrogen group-containing A toner comprising a reaction product obtained by reacting a compound and a polymer having reactivity to the active hydrogen group. The toner according to claim 6 or 7, wherein
The toner constituting the toner includes a polyester resin as the binder resin. In the process cartridge that supports the electrostatic latent image carrier and the developing means at least integrally and is detachable from the image forming apparatus main body,
The developing means stores toner for supplying the electrostatic latent image on the electrostatic latent image carrier to a toner image, and the toner is any one of claims 1 to 8. A process cartridge, which is the toner according to item 1. A toner production method according to any one of claims 1 to 8, comprising:
A toner material liquid composed of a liquid containing at least a binder, a colorant, and a microcrystalline wax that constitutes a molecular chain only with C—H bonds and C—C bonds is emulsified in an aqueous medium containing a surfactant. After the step of dispersing, the temperature (T1) of the toner dispersion in the surface treatment step of heating the toner dispersion obtained in that step is in the range of 45 ° C. to 90 ° C. . A method for producing the toner according to claim 10, comprising:
A method for producing a toner, wherein the temperature of the toner dispersion temperature (T1) in the surface treatment step is in the range of 45 ° C. to 90 ° C. for 1 minute or more and 1 hour or less. A toner production method according to claim 10 or 11,
The toner production method, wherein the amount of the surfactant in the surface treatment step is 0.1 to 2.0 times the critical micelle concentration of the surfactant.