JP4724600B2 - Toner and toner production method - Google Patents

Description

  The present invention relates to a toner used in an electrophotographic image forming method for developing an electrostatic image and a method for producing the toner.

  As a general electrophotographic image forming method, for example, a photoconductive material is used, an electric latent image is formed on an electrostatic latent image carrier by various means, and then the latent image is developed into a developing device. The toner image is visualized by developing it into a toner image, and then, if necessary, the toner image is transferred to a transfer material such as paper, and then fixed by heating, pressure, heating and pressurization or solvent vapor to obtain a toner image. The method is known.

  In recent years, the technical direction of image forming devices requires high definition, high quality, and high image quality, as well as higher speed and long-term reliability. As described above, the hardware configuration is configured with simple elements in various respects.

  In other words, in order to provide excellent hardware, further improvement in toner performance is very important. For example, in order to achieve a high-resolution, high-definition development method, the toner has a smaller particle size and a particle size distribution. Development of toners with high development characteristics, such as sharpening of toner and addition of surface modification process, is progressing.

  However, simply reducing the particle size, sharpening the particle size distribution, or modifying the surface may not only reduce the yield and productivity of the toner, but also improve the durability concentration stability. In some cases, it was inferior in terms of high resolution and high definition.

  In recent years, as one of the shape control methods, the shape of the toner has been made close to a spherical shape. For example, it is possible to use a polymerized toner produced by a polymerization method such as suspension polymerization or emulsion polymerization (for example, refer to Patent Documents 1 and 2), or to make a pulverized toner spherical with hot air (for example, refer to Patent Document 3). Can be mentioned. These techniques are very effective means for controlling the shape of the toner, but each has various problems. When a polymerized toner is used, the release agent is encapsulated in the toner. Therefore, if the pressure is not applied to the toner at the time of fixing, the release agent is less likely to come out on the toner surface and the fixing performance may be deteriorated. . In addition, when the pulverized toner is spheronized with hot air, depending on the hot air processing conditions, the more the spheronization progresses, the more easily the release agent contained in the toner is eluted into the toner surface by heat. May adversely affect electrophotographic properties and requires caution.

  That is, in order to obtain a toner having excellent development characteristics in various points, the shape when the particle size is reduced, the distribution of the shape, and the very small fine powder (ultra fine powder) generated with the reduction in the particle size. It is necessary to control the ratio and the shape of the region more strictly.

  For example, Patent Document 4 describes a circularity of 1 μm to 3 μm and a circularity of 10 μm to 20 μm. Furthermore, in Patent Documents 5 to 7, there is a description regarding the number ratio of fine powder and the average circularity.

  In the above-mentioned literature, due to the problem of the measuring device, especially for ultrafine powder of about 0.25 to 1.00 μm, the measurement and control are not accurate enough, so the usage environment or long-term using a large-capacity process cartridge In the endurance, problems associated with ultrafine powders may become apparent.

  In the toner spheronization process, particularly in the toner spheronization process by mechanical impact, super fine powder is easily generated, and these super fine powders re-aggregate with the spheroidized toner. Even if the classification process is performed after the above process, it is difficult to remove the ultrafine powder from the toner, and it is easy to mix in the product.

  The ultra fine powder is excessively charged in the developing process, and may contaminate the carrier in the sleeve or the two-component developing system due to electrostatic adhesion, thereby causing a charging failure of the toner supplied later. In addition, depending on the usage environment and development conditions, the toner charge on the sleeve coat expanded, leading to blotches, charge-ups, fogging, and increased consumption by encouraging selective development. .

  Many proposals have been made to reduce the amount of ultrafine powder. For example, Patent Document 8 and Patent Document 9 propose a method of driving ultrafine powder onto the toner surface by mechanical impact after the classification process. However, agitation in the developing section and the toner container due to long-term durability caused peeling of the ultrafine powder hit on the toner surface, which was liable to adversely affect the developability.

  In toners applied to image forming devices aimed at energy saving in recent years, excellent low-temperature fixability that enables high-speed hardware has become indispensable, and high reliability at good low-temperature fixability and long-term durability In order to achieve compatibility, the selection of an appropriate material and the strict control of the toner shape are increasingly important.

  In addition, in the case of a magnetic one-component toner using a magnetic material as a colorant, which is advantageous in terms of downsizing of the apparatus, the above-mentioned problems tend to become more prominent, and prompt action is required. It was done.

JP 2004-145324 A JP 2000-75541 A JP 2000-29241 A JP 2002-278161 A JP 2005-195658 A JP-A-2005-196142 JP 2004-295106 A Japanese Patent Laid-Open No. 10-232507 JP-A-11-149174

  An object of the present invention is to provide a toner that solves the above problems.

  That is, the object of the present invention is to scatter or fog even when using a large-capacity process cartridge in which the process speed is increased or the toner filling amount in the developing device is increased, or even in a harsh environment. Since the occurrence of blotch can be suppressed, high quality image quality can be obtained, transfer efficiency is high, toner consumption can be reduced, and at the same time, charging member contamination can be reduced, and a good image can be stably produced over a long period of time. It is to provide a toner that can be obtained.

  A further object of the present invention is to achieve an improvement in productivity by increasing the throughput and increasing the processing capacity as compared with the conventional surface reforming apparatus.

As a result of intensive studies, the present inventors have
In toner particles containing at least a binder resin and a colorant, and toner containing inorganic fine particles,
The toner particles have a weight average particle diameter (D4) of 4.0 μm to 7.5 μm,
In the flow type particle image measuring apparatus having an image processing resolution of 512 × 512 pixels (0.19 μm × 0.19 μm per pixel),
1) The average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.940 or more and 0.970 or less,
2) The ratio of the number of particles with an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm to the number of particles with an equivalent circle diameter of 0.25 μm or more and less than 30.0 μm is 1.0% or more and 12.0% or less,
3) The difference between the average circularity at an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.020 or less. It has been found that the object of the present invention can be achieved by using toner, and the present invention has been completed.

Furthermore, a kneading step of melt-kneading a composition containing at least a binder resin and a colorant, a cooling step of cooling the obtained kneaded product, a step of pulverizing the cooled solidified product to obtain a finely pulverized product, and A surface modification step for modifying the surface of the finely pulverized product to obtain toner particles,
The step of performing the surface modification step to obtain toner particles is performed using a batch type surface modification device,
The surface modification step performs a surface modification step for performing surface modification of particles contained in the obtained finely pulverized product and a classification for removing the fine powder contained in the obtained finely pulverized product by suction. After performing the classification process at the same time, it has a discharge process of sucking and discharging from the product discharge part,
When discharging the surface-modified particles from the product discharge section, the air volume M1 for sucking the classification section and the air volume M2 for sucking the discharge section are expressed by the following equation: M1 ≧ 1.2 × M2
It has been found that the object of the present invention can be achieved by the toner production method characterized by satisfying the above requirements, and the present invention has been completed.

  According to the toner of the present invention, even when a large-capacity process cartridge in which the process speed is increased or the toner filling amount in the developing device is increased, or in a harsh environment, the toner is scattered or fogged. Since the occurrence of blotches can be suppressed, high quality image quality can be obtained.

  Further, according to the toner of the present invention, the transfer efficiency is high, the toner consumption can be reduced, and at the same time, the charging member contamination can be reduced, and a good image can be stably obtained over a long period of time.

  In addition, according to the toner manufacturing method of the present invention, compared to a conventional surface reforming apparatus, uniform processing is possible, the yield is high, and processing capacity is achieved, so that improvement in productivity is achieved. Can do.

In the present invention, at least toner particles containing a binder resin and a colorant, and toner containing inorganic fine particles,
The toner particles have a weight average particle diameter (D4) of 3.0 μm or more and 8.0 μm or less,
In the flow type particle image measuring apparatus having an image processing resolution of 512 × 512 pixels (0.19 μm × 0.19 μm per pixel),
1) The average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.940 or more and 0.970 or less,
2) The ratio of the number of particles with an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm to the number of particles with an equivalent circle diameter of 0.25 μm or more and less than 30.0 μm is 1.0% or more and 12.0% or less,
3) It is important that the difference between the average circularity at an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.020 or less. .

  That is, it is important that the toner particles of the present invention have a weight average particle diameter (D4) of 3.0 to 8.0 μm, more preferably 3.5 to 8.0 μm, and still more preferably 4. 0 to 7.5 μm.

  When the weight average particle diameter (D4) of the toner particles is less than 3.0 μm, not only the fogging and scattering may be worsened, but also the toner handling property tends to be worsened. On the other hand, when the particle size is larger than 8.0 μm, there is a problem in terms of high image quality, such as fine line reproducibility, depending on the size of the toner particles themselves, which is not preferable, and the toner consumption tends to increase. Therefore, it is disadvantageous in terms of downsizing the device.

  The weight average particle diameter (D4) can be measured using a Coulter Multisizer II (trade name, manufactured by Coulter, Inc.), which is a particle diameter measuring machine. For example, measurement can be performed by connecting a number distribution and volume distribution interface (manufactured by Nikka) and a personal computer to the Coulter Multisizer II.

  As an electrolytic solution used for preparing a test sample, a 1% NaCl aqueous solution in which a reagent primary sodium chloride is dissolved in water can be used. In addition, as the electrolytic solution, for example, ISOTONR-II (manufactured by Coulter Scientific Japan, trade name) can be used.

  The test sample was added with 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, as a dispersant in 100 to 150 ml of the electrolytic solution, and further added with 2 to 20 mg of toner. It can be prepared by dispersing for 3 minutes. In the measurement of the weight average particle diameter (D4) by the Coulter multisizer, a 100 μm aperture can be used as the aperture.

  The weight average particle diameter (D4) in the present invention was determined from the volume distribution by measuring the volume and number of individual particles of a toner particle group having a particle diameter of 2 μm or more, and calculating the volume distribution and number distribution. It can be obtained as a weight average particle diameter (D4) based on weight (representing the representative value of each channel as the representative value for each channel).

  The weight average particle diameter (D4) of the toner can be adjusted by, for example, pulverizing / classifying the toner or mixing a classified product having an appropriate particle diameter.

  Further, in a flow type particle image measuring apparatus having an image processing resolution of 512 × 512 pixels (0.19 μm × 0.19 μm per pixel), an average circularity measured and a circle equivalent diameter of 0.25 μm or more and less than 30.0 μm It is important that the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm (hereinafter referred to as “ultrafine powder”) to the number of particles is in the specific range.

  The measurement principle of the flow-type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) is to take a flowing particle as a still image and perform image analysis. The sample added to the sample chamber is fed into the flat sheath flow cell by a sample suction syringe. The sample fed into the flat sheath flow is sandwiched between sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Further, since the flow is flat, the image is taken in a focused state. The particle image is picked up by a CCD camera, and the picked-up image is image-processed at an image processing resolution of 512 × 512 (0.19 × 0.19 μm per pixel), the contour of each particle image is extracted, Projected area, perimeter, etc. are measured.

Next, the projected area S and the perimeter L of each particle image are obtained. Using the area S and the perimeter L, the equivalent circle diameter and the circularity are obtained. The circular equivalent diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity is a value obtained by dividing the circumference of the circle obtained from the circular diameter by the circumference of the projected particle image. Defined and calculated by the following formula.
C = 2 × √ (π × S) / L

  When the particle image is circular, the degree of circularity is 1, and the degree of unevenness on the outer periphery of the particle image increases, and the degree of circularity decreases.

  After calculating the circularity of each particle, the range of the circularity of 0.2 to 1.0 is divided into 800, and the average circularity is calculated using the number of measured particles.

The average circularity in the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.940 or more and 0.970 or less (more preferably 0.941 or more and 0.968 or less, and further preferably 0.942 or more and 0.965 or less). And
The ratio of the number of particles having an equivalent circle diameter of 0.25 μm to less than 1.98 μm to the number of particles having an equivalent circle diameter of 0.25 μm to less than 30.0 μm is 1.0% to 12.0% (more preferably 1 2% or more and 11.0% or less, more preferably 1.4% or more and 10.0% or less.

  When the average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.940 or more and 0.970 or less, the toner charge amount distribution on the sleeve is likely to be uniform, and the toner coat amount is also easily stabilized. .

  When the average circularity is less than 0.940, the contact area between the toner particles or between the toner and the carrier becomes large, so that the transfer efficiency tends to decrease. In addition, the charge amount distribution tends to be broad, the developability tends to decrease, and the toner consumption tends to increase.

  On the other hand, when the average circularity is greater than 0.970, the shape of the toner particles approaches a spherical shape, so that frictional charging between the toners or between the toner and the charging member is difficult to occur, and fogging and scattering occur. It is easy to cause an unclear image.

  Further, the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm to the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 30.0 μm is 1.0% or more and 12.0% or less. is important. In order to adjust the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm to be less than 1.0%, in the toner production, the classification process is repeated or ultra fine powder is driven onto the toner surface. In the method, it is necessary to take measures such as strengthening the driving, and the productivity of the toner is remarkably lowered, which is not realistic.

  On the other hand, when the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm is more than 12.0%, the fog may be easily deteriorated depending on the use environment or the durable development conditions, Easily accumulates in the lower layer of the sleeve, tends to cause an increase in the charge amount distribution, and tends to lead to a decrease in blotch and transfer efficiency, and an increase in consumption. Furthermore, the super fine powder is likely to accumulate and adhere to the charging member, and image defects due to poor charging are likely to occur, and image streaks due to charge-up are likely to occur.

  Further, the difference between the average circularity in the equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity in the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.020 or less (more preferably 0.015 Hereinafter, it is important that it is 0.012 or less. Thereby, it is likely that the expansion of the charge amount distribution is likely to be suppressed, and the blotch and the fog deterioration are likely to be suppressed. Furthermore, since the transfer capability between the toner particles is probably equal regardless of the particle diameter, the transfer efficiency is increased, and at the same time, the selective development is easily suppressed and the toner consumption is easily reduced.

  On the other hand, when the difference between the average circularity in the equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity in the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is larger than 0.020, The quantity distribution is easy to expand, and it is easy to cause the above problems.

  More preferably, the coefficient of variation (CV value) in circularity when the equivalent circle diameter is 0.25 μm or more and less than 1.98 μm is 9.0 or less (more preferably 8.5 or less, and still more preferably 8.0 or less). ). The coefficient of variation is the value obtained by dividing the standard deviation by the average circularity, but since the standard deviation depends on the size of the average circularity, the circularity distribution is more strictly controlled by controlling the value of the coefficient of variation. Can be controlled.

  Not only is the difference between the average circularity in the equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity in the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm small, the coefficient of variation of the circularity of the ultrafine powder is When it is 9.0 or less, it is particularly easy to achieve an improvement in transfer efficiency and a reduction in consumption by suppressing selective development.

  For the physical properties described above, that is, the average circularity in the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm, and the number of particles in the equivalent circle diameter of 0.25 μm or more and less than 30.0 μm, the equivalent circle diameter of 0.25 μm or more and less than 1.98 μm. The number ratio and variation coefficient of the particles, and the difference between the average circularity in the equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity in the equivalent circle diameter of 1.98 μm or more and less than 30.0 μm will be described later. It is possible to control in such a surface modification step.

  As the binder resin used in the present invention, various resin compounds conventionally known as binder resins can be used. Examples of such resins include vinyl resins, phenol resins, and natural resin-modified resins. Phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumaroindene resin, petroleum In particular, polyester resins and vinyl resins are more preferable in terms of chargeability and fixability, and more preferably contain polyester resins, from the viewpoint of fixability. As the binder resin, these resins can be used alone or in combination of two or more.

  In addition, it is presumed that toner particles having different particle sizes have different behaviors in the toner manufacturing apparatus related to pulverization / classification and surface modification. At that time, in order to control the toner particles in different particle size regions to have a more uniform circularity and modification degree, the reason is not clear, but the binder resin probably has appropriate flexibility and mechanical strength. The present inventors have found that this can be easily achieved.

  That is, in the present invention, it is more preferable to contain at least 50% by mass or more of a polyester-based resin component excellent in flexibility and mechanical strength not only for ensuring good fixability but also for the above-mentioned reasons. . When the content of the polyester resin component is less than 50% by mass, sufficient fixability cannot be obtained, and it becomes difficult to uniformly control the degree of circularity and the degree of modification in different particle size regions.

  Furthermore, it is preferable to use a mixture of a polyester resin and a vinyl resin as the binder resin, and to further include a hybrid resin component in which both partially react, to achieve both chargeability, fixing property and storage stability. Further, it is particularly preferable in that the binder resin is provided with appropriate flexibility and mechanical strength.

  The content of the polyester-based resin component in the present invention is a combination of the polyester-based resin component present in the polyester resin or the hybrid resin.

  The toner of the present invention preferably contains 3 to 50% by mass (preferably 5 to 40% by mass, more preferably 5 to 30% by mass) of a tetrahydrofuran-insoluble component (gel component) derived from the binder resin. Further, such a gel component preferably contains a hybrid resin that is a reaction product of a polyester resin component and a vinyl resin component. If the tetrahydrofuran insoluble content is less than 3% by mass, the high temperature offset cannot be satisfied. When the tetrahydrofuran insoluble content is more than 50% by mass, it becomes difficult to uniformly disperse the material such as the colorant in the toner, the chargeability of the toner is deteriorated, and not only the fog and the image density are lowered, but also the surface. The degree of modification tends to be uneven and it is difficult to achieve the object of the present invention.

  Since hybrid resin has both polyester resin composition and vinyl resin composition in the same molecule, it is easy to mix with raw materials that are easy to mix with polyester components (for example, coloring agents such as highly hydrophilic magnetic materials) and vinyl resin. It has the function of simultaneously improving the dispersibility of raw materials (for example, wax components having low polarity).

  In particular, the inclusion of a hybrid resin in the tetrahydrofuran-insoluble matter (gel component) makes it easier for the wax to be present in the vicinity of the gel component in the toner. As a result, the sharp melt property of the toner is increased, and the fixability is greatly improved. In addition, the inclusion of a hybrid resin in the gel component facilitates the incorporation of a colorant such as a magnetic substance that is not likely to enter the gel component into the gel component. Stability is improved, and developability and image quality are improved. In addition, the softening of the gel component probably reduces the portion of the toner particle surface that has excessive hardness, making it easier to uniformize the circularity and the degree of modification in different particle size regions. Easier to achieve.

  Further, the THF-soluble component of the vinyl-based resin component obtained as a residue by hydrolyzing the polyester-based resin component contained in the tetrahydrofuran-insoluble component has a molecular weight of 50,000 to 500,000 (preferably 50,000 to 300,000, more preferably). Has a main peak in the range of 50,000 to 200,000), a polyester resin component is hybridized to a vinyl resin component having a large molecular weight, thereby obtaining a gel structure having a large molecular weight and a large molecular weight between cross-linking points. It becomes possible.

  A toner containing such a tetrahydrofuran-insoluble component makes the tetrahydrofuran-insoluble component, which is a gel component, easy to move even with a small amount of heat at the time of fixing, and is bound compared to a case where a gel component having a low molecular weight between crosslinks is contained. Since the resin is easily softened by heat, fixability is improved. Furthermore, such a gel component can maintain a high viscosity even at a high temperature, and can improve high-temperature offset resistance. Further, since high temperature offset resistance can be maintained even with a small amount of gel component, a large amount of low molecular weight components can be contained, and the fixability can be further improved. Further, for the same reason as described above, it is easy to make the circularity and the modification degree uniform in different particle size regions.

  The polyester resin component contained in the tetrahydrofuran insoluble matter is hydrolyzed, and if the main peak molecular weight of the THF soluble content of the vinyl resin component obtained as a residue is less than 50,000, the gel component tends to be hard and fixed. Sexuality deteriorates. Further, since the molecular weight between the crosslinking points is small, the gel component is not flexible, the gel component is easily cut by the shearing force at the time of kneading into toner, and the high temperature offset resistance is deteriorated. When the main peak molecular weight is larger than 500,000, it becomes difficult to uniformly disperse the gel component in the toner, and developability deteriorates.

  The molecular weight distribution of the THF-soluble component of the vinyl resin component obtained by hydrolyzing the polyester resin component contained in the tetrahydrofuran-insoluble component as a residue can be measured by the following procedure.

  First, the tetrahydrofuran-insoluble matter derived from the binder resin is taken out from the toner, and the tetrahydrofuran-insoluble matter is heated in an alkaline aqueous solution to hydrolyze and remove the polyester resin component. Since the vinyl resin component remains as a resin component without being hydrolyzed, the residue is extracted and the molecular weight distribution is measured by GPC. A specific measurement method is shown below.

(1) Separation of tetrahydrofuran-insoluble matter The toner is weighed and placed in a cylindrical filter paper (for example, No. 86R size 28 × 10 mm, manufactured by Toyo Filter Paper Co., Ltd.) and applied to a Soxhlet extractor. Using 200 ml of tetrahydrofuran as a solvent, the tetrahydrofuran solubles are extracted for 16 hours. At this time, extraction is performed at a reflux rate such that the extraction cycle of tetrahydrofuran is about once every 4 to 5 minutes. After completion of the extraction, the cylindrical filter paper is taken out, and the tetrahydrofuran-insoluble content of the toner on the cylindrical filter paper is collected.

  In the case where the toner is a magnetic toner containing a magnetic substance, the collected tetrahydrofuran-insoluble matter is put in a beaker, and tetrahydrofuran is added and dispersed sufficiently. Then, the magnet is brought close to the bottom of the beaker to precipitate the magnetic substance on the bottom of the beaker. Fix it. In this state, the gel component dispersed in tetrahydrofuran and tetrahydrofuran is transferred to another container to remove the magnetic material, and tetrahydrofuran is evaporated to separate the tetrahydrofuran-insoluble matter derived from the binder resin.

(2) Separation of vinyl-based resin component by hydrolysis The tetrahydrofuran-insoluble matter derived from the resulting binder resin was dispersed in a 2 mol NaOH aqueous solution at a concentration of 1% by mass, and the polyester was obtained under the conditions of a pressure vessel, 150 ° C. and 24 hours. Hydrolyzes the resin component. The vinyl resin component is separated from this hydrolyzed solution by the following procedure.

  i) The hydrolyzate was suction filtered using a membrane filter to separate the vinyl resin component as a residue. Thereby, the monomer component which is a decomposition product of the polyester resin component is removed in the filtrate.

  ii) Since the vinyl resin component which is a residue is converted to a sodium salt by hydrolysis of the acrylic ester component contained in the vinyl resin component, the residue is added with dispersed hydrochloric acid in water to pH = 2 The COO-group generated by hydrolysis of the acrylic ester component contained in the vinyl resin component was protonated, and then filtered and separated with a membrane filter.

(3) GPC measurement of vinyl resin component The vinyl resin component contained in the tetrahydrofuran insoluble matter separated by hydrolysis is dissolved in tetrahydrofuran, and the molecular weight distribution is measured by GPC.

  The toner of the present invention has a main peak in the molecular weight distribution of 2,000 to 30,000 (preferably 3,000 to 20,000, more preferably 5,000 to 10,000) in the GPC molecular weight distribution of the THF soluble content of the toner. And containing 3 to 30 area% (preferably 5 to 25 area%, more preferably 5 to 20 area%) of a component having a molecular weight in the range of 40,000 to 1,000,000. In the molecular weight distribution of the THF soluble matter of the toner, it has a main peak in the low molecular weight region, contains a certain amount of components in the high molecular weight region, and further has a gel component as described above, thereby fixing at a high level. It is possible to provide stable developability (high durability) over a long period of use while maintaining the properties and high-temperature offset resistance.

  The hybrid resin component having a large molecular weight between crosslinking points, which is a feature of the present invention, easily incorporates a low molecular weight component having a peak molecular weight of 2,000 to 30,000 into the crosslinked structure, so that the gel component is melted by heat. It becomes easy and fixing property improves. Moreover, since the high molecular weight component in the molecular weight range of 40,000 to 1,000,000 improves the mixing property of the low molecular weight component and the gel component, the high temperature offset resistance is improved. In addition, since the gel component is uniformly mixed in the toner, the pulverization property at the time of toner production is improved, and the ultrafine powder and coarse powder generated during the pulverization are greatly reduced. As a result, the factor that inhibits charging of the toner is reduced, and excellent development durability can be provided.

  When the main peak has a molecular weight of less than 2,000, the storability and developability of the toner tend to deteriorate, and when it exceeds 30,000, the fixability tends to deteriorate.

  When the component having a molecular weight in the range of 40,000 to 1,000,000 is less than 3% by area, the uniform mixing property of the gel component is liable to be lowered, and ultrafine powder and coarse powder are liable to be generated during pulverization, and the development durability is liable to deteriorate. . If the component having a molecular weight in the range of 40,000 to 1,000,000 is more than 30% by area, the toner viscosity becomes too high and the fixability tends to deteriorate.

  The binder resin used in the present invention can be used alone as a hybrid resin, but may be a mixture containing other resin components as long as it contains at least a hybrid resin.

  For example, a mixture of a hybrid resin and a vinyl resin, a mixture of a hybrid resin and a polyester resin, a mixture of a polyester resin, a hybrid resin, and a vinyl resin, or the like can be given.

  The hybrid resin is formed by a transesterification reaction between a polyester component and a vinyl polymer component obtained by polymerizing a monomer component having a carboxylic acid ester group such as (meth) acrylic acid ester, a polyester component and (meth) acrylic acid. Unsaturated polyester resin polymerized using a monomer having an unsaturated group such as fumaric acid formed by esterification with a vinyl polymer component obtained by polymerizing a monomer component having a carboxylic acid group such as There are those formed by polymerizing vinyl monomers in the presence of components.

  The hybrid resin contains a monomer component capable of reacting with both resin components in the vinyl resin component and / or polyester resin component, and among the monomers constituting the polyester resin component that can be obtained by reacting them, Examples of those that can react with the vinyl resin component include unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Among the monomers constituting the vinyl resin component, those that can react with the polyester component include those having a carboxyl group or a hydroxy group, and (meth) acrylic acid or (meth) acrylic acid esters.

  As a manufacturing method which can prepare the hybrid resin used by this invention, the manufacturing method shown to the following (1)-(6) can be mentioned, for example.

  (1) The hybrid resin component is manufactured separately from the vinyl resin component and the polyester resin component, dissolved and swollen in a small amount of an organic solvent, added with an esterification catalyst and alcohol, and heated to perform a transesterification reaction. Thus, a hybrid resin having a polyester resin component and a vinyl resin component can be obtained.

  (2) A method of producing a hybrid resin having a polyester resin component and a vinyl resin component by reacting the polyester resin component in the presence of the vinyl resin component after the production. The hybrid resin is produced by a reaction between a vinyl resin component (a vinyl monomer can be added if necessary) and a polyester monomer (alcohol, carboxylic acid) and / or a polyester resin component. Also in this case, an organic solvent can be appropriately used.

  (3) A method of producing a hybrid resin having a polyester resin component and a vinyl resin component by producing and reacting a vinyl resin component in the presence of the polyester resin component after production. The hybrid resin is produced by a reaction between a polyester resin component (a polyester monomer can be added if necessary) and a vinyl monomer and / or a vinyl resin component.

  (4) After the vinyl resin component and the polyester resin component are produced, a hybrid resin is produced by adding a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) in the presence of these polymer components. Also in this case, an organic solvent can be appropriately used.

  (5) Vinyl resin component, polyester resin component, polyester resin component and vinyl resin component by mixing vinyl monomer and polyester monomer (alcohol, carboxylic acid, etc.) and continuously performing addition polymerization and condensation polymerization reaction Is produced. Furthermore, an organic solvent can be used as appropriate.

  In the production methods (1) to (5) above, a vinyl resin component and / or a polyester resin component can use polymer components having a plurality of different molecular weights and degrees of crosslinking.

  The production method particularly preferably used in the present invention includes (3). Among them, an unsaturated polyester resin capable of reacting with a vinyl monomer is dissolved in the vinyl monomer, and a mixture of the polyester resin and the vinyl monomer is prepared. Those obtained by polymerization by a bulk polymerization method are preferred.

  Bulk polymerization is preferably used in the present invention because the molecular weight of the vinyl resin component can be increased and the main peak molecular weight of the vinyl resin component contained in the gel component can be increased.

  The bulk polymerization method does not require a step such as evaporation of the solvent as compared with the solution polymerization method, so that a binder resin can be obtained at a low cost. Also, compared with the suspension polymerization method, a dispersant or the like can be obtained. Since it does not contain impurities, it has a great merit as a binder resin for toners, such as being able to obtain excellent developability with little influence on the chargeability of the toner, etc., which is preferable.

  In particular, the binder resin used in the present invention is a vinyl monomer in the presence of an unsaturated polyester resin, unsaturated polyester resin: vinyl monomer = 50: 50 to 90:10 (preferably 60:40 to 80:20). It is preferable to contain a hybrid resin component obtained by bulk polymerization at a mass ratio of When the mass ratio of the unsaturated polyester resin is less than 50:50, the fixability tends to be deteriorated, and when it is more than 90:10, the high temperature offset resistance tends to be deteriorated.

  The unsaturated polyester resin component used in the hybrid resin obtained by the bulk polymerization method of the present invention has a molecular weight of 2,000 to 30,000 (preferably 3,000 to 20,000, more preferably) in the GPC molecular weight distribution of THF-soluble matter. A low molecular weight unsaturated polyester resin component having a main peak in the range of 5,000 to 10,000) is preferably used, and a linear unsaturated polyester resin component containing no gel component is particularly preferable. When the main peak molecular weight is less than 2,000, the developability tends to deteriorate, and when it exceeds 30,000, the fixability tends to deteriorate.

  Further, the unsaturated polyester resin component used in the present invention has a number average molecular weight (Mn) of 2,000 to 20,000, preferably 3,000 to 10,000. When the number average molecular weight (Mn) is less than 2,000, a gel component is hardly generated in the hybrid resin, and high temperature offset resistance and development durability are likely to deteriorate. If the number average molecular weight (Mn) is greater than 20,000, the solubility of the unsaturated polyester resin component in the vinyl monomer is lowered, making it difficult to obtain a hybrid resin by bulk polymerization, and the polyester resin component and the vinyl resin Not only the resin component may be separated or the chargeability of the toner may be deteriorated, but also it becomes difficult to make the circularity and the modification degree uniform in different particle size regions.

  The unsaturated polyester resin component used in the present invention is a ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), Mw / Mn is 1.0 to 5.0, preferably 1.0 to 3.0. Is preferable from the viewpoint of the control of the sharp melt property at the time of fixing and the circularity distribution.

  If Mw / Mn is greater than 5.0, the fixability tends to deteriorate.

  By bulk polymerization of vinyl monomers in the presence of such unsaturated linear polyester resin components, low molecular weight polyester resin components are vinyl-based with a vinyl resin component having a large molecular weight and high linearity as the main chain. A hybrid resin component having a molecular structure branched from the resin component can be obtained. Furthermore, the acid group and the hydroxyl group in the hybrid resin having this branched structure form an ester bond between molecules to form a gel component.

  The gel component formed by the hybrid resin thus obtained has a large molecular weight between cross-linking points and is easily softened by heat. Further, since the molecular structure contains a large amount of the polyester resin component, a low molecular weight polyester resin component that is not hybridized can be incorporated in a large amount into the gel structure. As a result, even when a large amount of a low molecular weight polyester resin component having a low softening point is added, it is possible to maintain the mechanical strength of the toner, and to achieve both excellent fixing properties and development durability. . Furthermore, a gel component having a large molecular weight between cross-linking points and a high linearity has a high molecular structure and is strong in shearing force, so that the gel component is less likely to be cut in the kneading step of toner formation. Therefore, it is possible to make the toner contain a constant gel component regardless of the kneading conditions, and it is possible to stably impart excellent high temperature offset resistance to the toner.

  The composition of the polyester resin used in the present invention is as follows.

  Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenol represented by the formula (A) and derivatives thereof;

（式中Ｒはエチレンまたはプロピレン基であり、ｘ，ｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０〜１０である。）
また（Ｂ）式で示されるジオール類；

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
And diols represented by the formula (B);

  Examples of the divalent acid component include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride or anhydrides thereof, lower alkyl esters; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid. Dicarboxylic acids and derivatives thereof such as acids or anhydrides thereof, lower alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid and n-dodecyl succinic acid, or anhydrides, lower alkyl esters thereof, and the like.

  As the acid component having an unsaturated group for obtaining an unsaturated polyester resin, unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid and itaconic acid, or anhydrides thereof, lower alkyl esters and the like are preferably used.

  These unsaturated dicarboxylic acids may be added at a ratio of 0.1 to 10 mol% (preferably 0.3 to 5 mol%, more preferably 0.5 to 3 mol%) with respect to the total acid component of the polyester monomer. preferable. When the unsaturated dicarboxylic acid is added in this range, the unsaturated group concentration in the low molecular weight polyester molecule is optimal. When the amount of unsaturated dicarboxylic acid is less than 0.1 mol%, the polyester resin component and the vinyl resin component are not easily hybridized, and the effect of improving the fixability and developability is hardly obtained. When the amount of unsaturated dicarboxylic acid is more than 10 mol%, the number of unsaturated groups contained in one molecule of the polyester resin increases, so the vinyl resin that hybridizes with one molecule of the polyester resin increases, and the molecular weight between crosslinking points decreases. Gel component tends to be hard. As a result, the fixing property is deteriorated, or the gel component is sheared by kneading at the time of toner formation, and the high temperature offset resistance is deteriorated.

  Further, a trivalent or higher alcohol component or a trivalent or higher acid component may be used as necessary.

  Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Is mentioned.

  Examples of the trivalent or higher polyvalent carboxylic acid component include pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2 , 4-Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane 1,2,7,8-octanetetracarboxylic acid, empol trimer acid, and their anhydrides, lower alkyl esters;

（式中Ｘは炭素数３以上の側鎖を１個以上有する炭素数５〜３０のアルキレン基又はアルケニレン基）
で表わされるテトラカルボン酸等、及びこれらの無水物、低級アルキルエステル等の多価カルボン酸類及びその誘導体が挙げられる。なかでも、１，２，４−ベンゼントリカルボン酸、１，２，５−ベンゼントリカルボン酸およびこれらの無水物、低級アルキルエステルが好ましい。

(Wherein X is an alkylene group or alkenylene group having 5 to 30 carbon atoms having one or more side chains having 3 or more carbon atoms)
And polycarboxylic acids such as anhydrides and lower alkyl esters thereof and derivatives thereof. Of these, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, anhydrides thereof, and lower alkyl esters are preferable.

  The alcohol component used in the present invention is 40 to 60 mol%, preferably 45 to 55 mol%, and the acid component is 60 to 40 mol%, preferably 55 to 45 mol%. Moreover, it is preferable that the polyvalent component more than trivalence is 0.1-60 mol% in all the components.

  The polyester resin is usually obtained by a generally known condensation polymerization. The polymerization reaction of the polyester resin is usually carried out in the presence of a catalyst at a temperature of about 150 to 300 ° C., preferably about 170 to 280 ° C. The reaction can be performed under normal pressure, reduced pressure, or increased pressure, but after reaching a predetermined reaction rate (for example, about 30 to 90%), the reaction system is 200 mmHg or less, preferably 25 mmHg or less, more preferably 10 mmHg. It is desirable to carry out the reaction under reduced pressure below.

  Examples of the catalyst include catalysts usually used for polyesterification, for example, metals such as tin, titanium, antimony, manganese, nickel, zinc, lead, iron, magnesium, calcium, germanium; and these metal-containing compounds (dibutyltin oxide, orthodibutyl). Titanate, tetrabutyl titanate, tetraisopropyl titanate, zinc acetate, lead acetate, cobalt acetate, sodium acetate, antimony trioxide, etc.).

  In the present invention, a titanium compound is preferably used because of easy control of the polymerization reaction and high reactivity with the vinyl monomer, and tetrabutylisopropyl titanate, dipotassium oxalate titanate, titanium terephthalate are particularly preferable. Examples include potassium acid. At this time, it is particularly preferable to add an antioxidant (particularly a phosphorus-based antioxidant) as an anti-coloring agent for the binder resin and a co-catalyst (a magnesium compound is preferable, and magnesium acetate is particularly preferable) as a reaction accelerator.

  The polyester of the present invention is stopped by stopping the reaction when the properties of the reactant (for example, acid value, softening point, etc.) reach a predetermined value, or when the stirring torque or stirring power of the reactor reaches a predetermined value. System resin can be obtained.

  In the present invention, the vinyl resin component means a vinyl homopolymer or a vinyl copolymer.

  Examples of the monomer for obtaining the vinyl resin component include the following.

  For example, styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4- Dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl Styrene derivatives such as styrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Unsaturated polyenes such as butadiene and isoprene; Vinyl halides such as vinyl chloride, vinyl bromide and vinyl fluoride; Acetic acid Vinyl esthetics such as vinyl, vinyl propionate and vinyl benzoate Class: methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacryl Α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl acid, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, Acrylic esters such as dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; vinyl methyl ether, vinyl ethyl ether Ter, vinyl ethers such as vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N- such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone. Vinyl compounds; vinyl naphthalenes; acrylic acid derivatives or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide. These vinyl monomers are used alone or in admixture of two or more monomers.

  Among these, a combination of monomers that becomes a styrene copolymer or a styrene acrylic copolymer is preferable.

  Furthermore, as a monomer for adjusting the acid value of the binder resin, for example, acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, and α- or β-alkyl derivatives thereof, fumaric acid, maleic acid, There are unsaturated dicarboxylic acids such as citraconic acid and their monoester derivatives or maleic anhydride, and such monomers are used alone or mixed to copolymerize with other monomers to produce the desired binder resin. Can do. Among these, it is particularly preferable to use a monoester derivative of an unsaturated dicarboxylic acid in order to control the acid value.

  More specifically, for example, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate, monophenyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monophenyl fumarate Monoesters of α, β-unsaturated dicarboxylic acids such as: monobutyl n-butenyl succinate, monomethyl n-octenyl succinate, monoethyl n-butenylmalonate, monomethyl n-dodecenyl glutarate, monobutyl n-butenyl adipate Monoesters of alkenyl dicarboxylic acids such as, and the like; monoesters of aromatic dicarboxylic acids such as phthalic acid monomethyl ester, phthalic acid monoethyl ester, phthalic acid monobutyl ester, and the like.

  The carboxyl group-containing monomer as described above is preferably added in an amount of 0.1 to 30% by mass (more preferably 0.5 to 10% by mass) with respect to all monomers constituting the vinyl resin component. By adding a monomer having an acid value, the molecular structure of the gel component in the toner can have an appropriate acid value. If the gel component does not have a polar group, it becomes difficult to control the dispersion state of the wax, and the chargeability of the toner is deteriorated, and problems such as developability are likely to occur. In this way, by adding an acid value to the molecular structure of the gel component, it becomes easier to finely disperse the wax component in the toner, which is difficult to control the dispersion state, in the vicinity of the gel component, and the toner has a stable chargeability. Can be provided.

  Since the vinyl resin component contained in the gel component of the present invention preferably has a high linearity, it preferably contains no crosslinkable monomer, but in order to achieve the object of the present invention, the following examples are given. It is also possible to add such a crosslinkable monomer.

  As the crosslinkable monomer, a monomer having two or more polymerizable double bonds is mainly used. Aromatic divinyl compounds (eg, divinylbenzene, divinylnaphthalene, etc.); diacrylate compounds linked by alkyl chains (eg, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate) , 1,5-pentanediol acrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); di-linked by an alkyl chain containing an ether bond Acrylate compounds (eg, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); diacrylate compounds linked by a chain containing an aromatic group and an ether bond (eg, polyoxyethylene (2 ) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate, and acrylates of the above compounds are replaced with methacrylate. Polyester type diacrylate compounds (for example, trade name MANDA (Nippon Kayaku)). As polyfunctional crosslinking agents, pentaerythritol acrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds are replaced with methacrylate. Triallyl cyanurate, triallyl trimellitate and the like.

  These crosslinking agents are preferably used in an amount of 1 part by mass or less, preferably 0.001 to 0.05 parts by mass with respect to 100 parts by mass of the other vinyl monomer components.

  In order to achieve the object of the present invention, the vinyl resin component used for the preparation of the binder resin is produced by using a polyfunctional polymerization initiator alone or in combination with a monofunctional polymerization initiator as exemplified below. It is preferable.

  Specific examples of the polyfunctional polymerization initiator having a polyfunctional structure include 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-hexylperoxy- 3,3,5-trimethylcyclohexane, 1,1-di-t-amylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxy-2-methylcyclohexane, 1,3 -Bis- (t-butylperoxyisopropyl) benzene, 1,3-bis- (neodecanolperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexyne-3, 2,5-dimethyl-2,5-di- (2-ethylhexanolperoxy) hexane, 2, 5-dimethyl-2,5-di- (m-toluolperoxy) hexane, 2,5-dimethyl-2,5-di- (benzoylperoxy) hexane, tris- (t-butylperoxy) triazine, 1,1-di-t-butylperoxycyclohexane, 1,1-di-t-hexylperoxycyclohexane, 1,1-di-t-amylperoxycyclohexane, 1,1-di-t-butylperoxycyclohexane Cyclododecane, 2,2-di-t-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester, di-t-butylperoxyhexahydroterephthalate, di-t -Butylperoxyhexahydroisophthalate, di-t-butylperoxyazelate, tert-butylperoxytrimethyladipate , 2,2-bis- (4,4-di-t-butylperoxycyclohexyl) propane, 2,2-t-butylperoxyoctane and various polymer oxides, and two or more peroxide groups in one molecule A polyfunctional polymerization initiator having a functional group having a polymerization initiation function such as diallyl peroxydicarbonate, t-butylperoxymaleic acid, t-butylperoxyallylcarbonate, t-butylperoxyisopropyl fumarate, etc. The polyfunctional polymerization initiator which has both the functional group which has polymerization initiation functions, such as a peroxide group, and a polymerizable unsaturated group in 1 molecule of these is mentioned.

  Of these, more preferred are 1,3-bis- (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, 2,5- Dimethyl-2,5-di- (t-butylperoxy) hexyne-3 and 2,2-bis- (4,4-di-t-butylperoxycyclohexyl) propane.

  These polyfunctional initiators are preferably used in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the monomer from the viewpoint of efficiency.

  Furthermore, these polyfunctional polymerization initiators can be used in combination with a monofunctional polymerization initiator in order to satisfy various performances required as a binder for toner.

  In particular, it is preferable to use in combination with a polymerization initiator having a half-life of 10 hours lower than the decomposition temperature for obtaining a half-life of 10 hours of the polyfunctional polymerization initiator.

  Specifically, benzoyl peroxide, n-butyl-4,4-di (t-butylperoxy) valerate, dicumyl peroxide, α, α′-bis (t-butylperoxydiisopropyl) benzene, t- Examples thereof include organic peroxides such as butyl peroxycumene and di-t-butyl peroxide, and azo and diazo compounds such as azobisisobutyronitrile and diazoaminoazobenzene.

  These monofunctional polymerization initiators may be added to the monomer at the same time as the polyfunctional polymerization initiator, but in order to keep the efficiency of the polyfunctional polymerization initiator appropriate, vinyl in the polymerization step is used. It is preferable to add after the polymerization addition rate of the monomer reaches 50% or more.

  The binder resin of the present invention is preferably obtained by a bulk polymerization method in which a vinyl monomer is polymerized without using a solvent or the like in the presence of the unsaturated polyester resin component as described above. Furthermore, it is preferable to add waxes in this step from the viewpoint of improving the dispersibility of the waxes. In particular, a polymerization initiator having a 10-hour half-life temperature of 100 to 150 ° C. is used, a temperature that is 30 ° C. lower than the 10-hour half-life temperature of the polymerization initiator, and a temperature that is 10 ° C. higher than the 10-hour half-life temperature. In this range, it is preferable to carry out the polymerization reaction until the polymerization conversion rate of the vinyl monomer reaches 60%, preferably 80% or more, and to increase the molecular weight of the vinyl resin component produced by bulk polymerization. Furthermore, after the polymerization conversion rate reaches 60% (preferably 80%) or more, the polymerization reaction is preferably carried out at a temperature higher by 10 ° C. or more than the 10-hour half-life temperature to terminate the reaction.

  The glass transition temperature (Tg) of the binder resin used in the present invention is preferably 50 to 75 ° C. When the glass transition temperature of the binder resin is less than 50 ° C., the storage stability of the toner may be insufficient, and when it is higher than 75 ° C., the toner fixability may be insufficient.

  The binder resin used in the present invention has an acid value of 0.1 to 50 mgKOH / g (preferably 1 to 40 mgKOH / g, more preferably 1 to 30 mgKOH / g), and a hydroxyl value of 5 to 80 mgKOH / g (preferably A range of 5 to 60 mgKOH / g, more preferably 10 to 50 mgKOH / g) is preferable in terms of chargeability of the toner and ease of circularity control by appropriate mechanical strength.

  The acid value of the binder resin is determined, for example, by the operations 1) to 5) below. The basic operation belongs to JIS K0070.

  1) The sample is used by removing additives other than the binder resin (polymer component) in advance, or the content of components other than the binder resin in the sample is obtained. Weigh accurately 0.5 to 2.0 g of the pulverized product of magnetic toner or binder resin. The mass of the binder resin component at this time is defined as W (g).

  2) A sample is put into a 300 (ml) beaker, and a mixed solution 150 (ml) of toluene / ethanol (4/1) is added and dissolved.

  3) Using an ethanol solution of 0.1 mol / l KOH, measurement is performed using a potentiometric titrator. For this titration, for example, an automatic titration using a potentiometric titration measuring device AT-400 (winworkstation) of Kyoto Electronics Co., Ltd. and an ABP-410 electric burette can be used.

  4) The amount of KOH solution used at this time is S (ml). At the same time, a blank is measured, and the amount of KOH used at this time is defined as B (ml).

5) Calculate the acid value according to the following formula. In the following formula, f is a factor of KOH.
Acid value (mgKOH / g) = {(SB) × f × 5.61} / W

  The OH value is determined, for example, by the following operations 1) to 8). Basic operation conforms to JIS K0070.

  1) The sample is used by removing additives other than the binder resin (polymer component) in advance, or the content of components other than the binder resin in the sample is obtained. 0.5-2.0 g of the pulverized toner or binder resin is precisely weighed into a 200 ml flat bottom flask.

  2) Add 5 ml of acetylating reagent (take 25 g of acetic anhydride into a total volume flask (100 ml), add pyridine to bring the total volume to 100 ml and stir well). If the sample is difficult to dissolve, add a small amount of pyridine, or dissolve by adding xylene or toluene.

  3) Place a small funnel in the mouth of the flask and immerse the bottom of about 1 cm in a glycerin bath at a temperature of 95-100 ° C. and heat. In order to prevent the temperature of the neck of the flask from rising due to the heat of the glycerin bath, a cardboard disc with a round hole in it is put on the base of the neck of the flask.

  4) After 1 hour, remove from the glycerin bath to the flask, allow to cool, add 1 ml of water from the funnel and shake to decompose acetic anhydride.

  5) To complete the decomposition further, the flask is again heated in a glycerin bath for 10 minutes, allowed to cool, and then the funnel and flask wall are washed with 5 ml of ethanol.

6) Add a few drops of phenolphthalein solution as an indicator, titrate with 0.5 kmol / m ³ potassium hydroxide ethanol solution, and end when the indicator is light red for about 30 seconds.

  7) Perform 2) to 6) as blank tests without adding resin.

8) Calculate the OH number by the following formula.
A = [{(BC) × 28.05 × f} / S] + D
(However, A is a hydroxyl value (mgKOH / g), B is the amount (ml) of 0.5 kmol / m ³ potassium hydroxide ethanol solution used for the blank test, and C is 0.5 kmol used for titration. / M ^{3 of} potassium hydroxide ethanol solution (ml), f is a factor of 0.5 kmol / m ³ potassium hydroxide ethanol solution, and S is the amount of binder resin (g) contained in the sample. Yes, D is the acid value of the sample, where “28.05” is the formula weight of potassium hydroxide (56.11 × 1/2))

  The acid value and hydroxyl value of the binder resin can be adjusted by, for example, the types of monomers constituting the binder resin and their blending amounts.

  In the present invention, other resins such as rosin, modified rosin, aliphatic or alicyclic hydrocarbon resin can be mixed with the above-described binder resin as necessary. When two or more kinds of resins are mixed and used as a binder resin, as a more preferable form, those having different molecular weights are preferably mixed at an appropriate ratio.

  The number average molecular weight and the weight average molecular weight of the binder resin are determined by dissolving the binder resin in tetrahydrofuran (THF) and measuring the solution by gel permeation chromatography (GPC), and measuring the count number (retention time). ) And logarithmic values of a calibration curve prepared using several types of monodisperse polystyrene standard samples. Further, the molecular weight of the binder resin can be adjusted by polymerization conditions, use of a crosslinking agent, kneading of the binder resin, and the like.

  The glass transition temperature of the binder resin is generally such that the theoretical glass transition temperature described in the publication Polymer Handbook 2nd edition III-p139-192 (manufactured by John Wiley & Sons) is 45-80 ° C. It can adjust by selecting the constituent material (polymerizable monomer) of resin. The glass transition temperature of the binder resin can be measured according to ASTM D3418-82 using a differential scanning calorimeter, for example, DSC-7 manufactured by PerkinElmer or DSC2920 manufactured by TA Instruments Japan. When the glass transition temperature of the binder resin is lower than the above range, the toner may have insufficient storability. When the glass transition temperature of the binder resin is higher than the above range, the toner may have insufficient fixability. It may become.

  The toner of the present invention may further contain a magnetic material and be used as a magnetic toner. In this case, the magnetic material can also serve as a colorant. By using the one-component development method, a carrier is unnecessary, which is advantageous in terms of downsizing the apparatus.

  In the present invention, the magnetic material contained in the magnetic toner includes iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel, or these metals aluminum, cobalt, copper, lead, magnesium, tin And alloys of metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.

These ferromagnetic materials have an average particle diameter of 2 μm or less, preferably 0.05 to 0.5 μm. Further, the magnetic characteristics when 795.8 kA / m is applied are as follows: coercive force 1.6 to 12.0 kA / m, saturation magnetization 50 to ²⁰⁰ Am ² / kg (preferably 50 to 100 Am ² / kg), residual magnetization 2 to 20 Am. Those of ² / kg are preferred.

  These ferromagnetic materials are contained in the toner in an amount of about 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight, based on 100 parts by weight of the resin component.

In particular, the content is preferably adjusted so that the true density of the toner particles is 1.50 or more and 2.00 (g / cm ³ ). When the true density of the toner particles is within this range, the surface modification of the toner particles is easily performed uniformly. The reason for this is not clear, but in the surface reforming apparatus described later, the circulation property of the toner particles in the apparatus is important. It is considered that the circulation of the toner particles can easily work efficiently, so that the circularity and the modification degree in different particle size regions can be easily made uniform, and the object of the present invention can be easily achieved.

  As the colorant used in the present invention, a black colorant that is toned in black using carbon black, grafted carbon or the following yellow / magenta / cyan colorant can be used.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds, and the like are used.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds, and the like are used.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. These colorants can be used alone or in combination and further in the form of a solid solution.

  The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  The toner of the present invention can be used as a two-component developer in combination with a carrier, and conventionally known carriers can be used as a carrier in the two-component development method. Specifically, particles having an average particle diameter of 20 to 300 μm, such as surface oxidized or unoxidized metals such as iron, nickel, cobalt, manganese, chromium, rare earth, and alloys or oxides thereof, are used.

  Further, those obtained by adhering or coating substances such as styrene resin, acrylic resin, silicone resin, fluorine resin, polyester resin on the surface of the carrier particles are preferably used.

  Moreover, in this invention, it is preferable to add and use a charge control agent. The charging property of the magnetic toner of the present invention may be positive or negative. However, since the binder resin itself has a high negative charging property, it is preferably a negatively charging toner.

  For example, organometallic complexes and chelate compounds are effective as negatively charged ones. Examples thereof include monoazo metal complexes; acetylacetone metal complexes; metal complexes of aromatic hydroxycarboxylic acids or aromatic dicarboxylic acids and their metals. Examples thereof include salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Preferred examples of the charge control agent for negative charging include Spiron Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-. 84, E-88, E-89 (Orient Chemical).

  Examples of those that are controlled to be positively charged include modified products of nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Onium salts such as phosphonium salts and the like, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (as rake agents, phosphotungstic acid, phosphomolybthenic acid, phosphotungstomolybthenic acid, tannic acid, Lauric acid, gallic acid, ferricyanic acid, ferrocyanic compound, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyl Rusuzuboreto, be mentioned, such as organo-tin borate of dicyclohexyl tin borate. These can be used alone or in combination of two or more.

  Preferred examples of the charge control agent for positive charging include TP-302, TP-415 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) N-01, N-04, N-07, P-51 (Orient Chemical Co., Ltd.) and Copy Blue PR (Clariant).

  These metal complex compounds can be used alone or in combination of two or more. The amount of these charge control agents used is preferably 0.1 to 5.0 parts by mass per 100 parts by mass of the binder resin from the viewpoint of the charge amount of the toner.

  The toner of the present invention may contain a wax.

  The waxes used in the present invention include the following. For example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax Or block copolymers thereof; plant waxes such as candelilla wax, carnauba wax, waxy wax, jojoba wax; animal waxes such as beeswax, lanolin, spermaceti; mineral systems such as ozokerite, ceresin, petrolactam; Waxes; waxes mainly composed of aliphatic esters such as montanic acid ester wax and castor wax; those obtained by partially or fully deoxidizing aliphatic esters such as deoxidized carnauba wax . Further, saturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a long-chain alkyl group; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinal acid; stearyl alcohol Saturated alcohol such as eicosyl alcohol, behenyl alcohol, cannavir alcohol, seryl alcohol, melyl alcohol, or alkyl alcohol having a long chain alkyl group; polyhydric alcohol such as sorbitol; linoleic acid amide, oleic acid amide, lauric acid Aliphatic amides such as acid amides; saturated aliphatic bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amides, ethylene bislauric acid amides, hexamethylene bisstearic acid amides; Unsaturated fatty acid amides such as inamide, hexamethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, Aromatic bisamides such as N'-distearylisophthalamide; aliphatic metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (commonly referred to as metal soap); aliphatic hydrocarbons Wax grafted with a vinyl monomer such as styrene or acrylic acid; Partial esterified product of fatty acid and polyhydric alcohol such as behenic acid monoglyceride; Hydroxyl group obtained by hydrogenating vegetable oil Methyl ester compounds It is.

  In addition, these waxes have a sharp molecular weight distribution using a press sweating method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method or a melt liquid crystal deposition method, a low molecular weight solid fatty acid, a low molecular weight A solid alcohol, a low molecular weight solid compound, and other impurities are preferably used.

  Specific examples of the wax that can be used as a release agent include Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries), high wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals), Sazol H1, H2, C80, C105, C77 (Schumann Sazol), HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP-12 (Nippon Seiki Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite) ), Wax, beeswax, rice wax, candelilla wax, carnauba wax (Serari Co., Ltd.) Available), and the like at the NODA.

  A fluidity improver may be added to the toner of the present invention. The fluidity improver can be added to the toner particles to increase the fluidity before and after the addition. Examples of such fluidity improvers include fluorine resin powders such as fine vinylidene fluoride powder and polytetrafluoroethylene fine powder; fine powder silica such as wet process silica and dry process silica, and fine powder titanium oxide. , Fine powder alumina, fine powder treated with silane compound, titanium coupling agent, silicone oil; oxides such as zinc oxide and tin oxide; strontium titanate, barium titanate, calcium titanate, zircon Examples thereof include double oxides such as strontium acid and calcium zirconate; calcium carbonate and carbonate compounds such as magnesium carbonate.

A preferred fluidity improver is a fine powder produced by vapor phase oxidation of a silicon halogen compound, and is referred to as so-called dry process silica or fumed silica. For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame is used, and the basic reaction formula is as follows.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  In this production process, it is also possible to obtain composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. To do. The particle size is preferably within the range of 0.001 to 2 μm as the average primary particle size, and particularly silica fine powder within the range of 0.002 to 0.2 μm is preferably used.

  Examples of commercially available silica fine powders produced by vapor phase oxidation of silicon halogen compounds include AEROSIL (Nippon Aerosil Co., Ltd.) 130, 200, 300, 380, TT600, MOX170, MOX80, COK84, Ca—O—SiL (CABOT CoL). Company) M-5, MS-7, MS-75, HS-5, EH-5, Wacker HDK N 20 (WACKER-CHEMIE GMBH) V15, N20E, T30, T40, DC Fine Silica (Dow Corning) Co.) and Fransol (Fransil) are commercially available, and these can also be used favorably in the present invention.

  Furthermore, as the fluidity improver used in the present invention, a treated silica fine powder obtained by hydrophobizing a silica fine powder produced by vapor phase oxidation of the silicon halogen compound is more preferable. In the treated silica fine powder, it is particularly preferred to treat the silica fine powder so that the degree of hydrophobicity measured by a methanol titration test is in the range of 30-80.

  As a hydrophobizing method, it is applied by chemical treatment with an organosilicon compound that reacts or physically adsorbs with silica fine powder. As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound.

  Examples of the organosilicon compound include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethridimethylchlorosilane, α- Chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyl Disiloxane, 1,3-divinyltetramethyldisiloxane, 1 , 3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one Si at each terminal unit. Furthermore, silicone oils such as dimethyl silicone oil can be mentioned. These may be used alone or as a mixture of two or more.

As the fluidity improver, those having a specific surface area of 30 m ² / g or more, preferably 50 m ² / g or more by nitrogen adsorption measured by the BET method, give good results. The total amount of the fluidity improver is 0.01 to 8 parts by weight, preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the toner.

  The toner of the present invention can be used as a one-component developer by mixing with the fluidity improver and, if necessary, further mixing with other external additives (for example, a charge control agent). And can be used as a two-component developer. As the carrier for use in the two-component development method, all conventionally known carriers can be used. Specifically, surface oxidized or unoxidized iron, nickel, cobalt, manganese, chromium, rare earth, etc. Particles with an average particle size of 20 to 300 μm, such as metals and their alloys or oxides, are preferably used.

  Further, those obtained by adhering or coating substances such as styrene resin, acrylic resin, silicone resin, fluorine resin, polyester resin on the surface of the carrier particles are preferably used.

  The method for producing the toner of the present invention will be described below.

  In order to achieve the object of the present invention, a step of adjusting the degree of circularity and the amount of ultrafine powder is required, but the other production steps are not particularly limited and can be produced by a known method.

  For example, the toner of the present invention is prepared by sufficiently mixing a binder resin and other materials such as a magnetic material or other colorant, wax, and charge control agent by a mixer such as a Henschel mixer or a ball mill. , Using a heat kneader such as a kneader or extruder to melt, knead, and knead to make the resins compatible with each other, disperse or dissolve the magnetic particles, pigment or dye, cool and solidify, and then grind Then, after the surface modification step, an external additive such as an inorganic fine powder is mixed by the mixer. If necessary, a classification step may be further performed either before or after the surface modification step.

  Henschel mixer (made by Mitsui Mining); Super mixer (made by Kawata); Ribocorn (made by Okawara Seisakusho); Nauter mixer, turbulizer, cyclomix (made by Hosokawa Micron); Pacific Kiko Co., Ltd.); Redige mixer (manufactured by Matsubo) and the like.

  As a kneading machine, KRC kneader (manufactured by Kurimoto Iron Works); Bus co-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); kneedex (manufactured by Mitsui Mining Co., Ltd.); MS pressure kneader, nider ruder (manufactured by Moriyama Seisakusho); Banbury mixer (manufactured by Kobe Steel) can be used.

  As a pulverizer, a counter jet mill, a micron jet, an inomizer (manufactured by Hosokawa Micron); an IDS type mill, a PJM jet pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.); a cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.); SK Jet Oh Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turbo Industry Co., Ltd.); Super Rotor (Nisshin Engineering).

  Classifiers include: Classy, Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nissin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron) An elbow jet (manufactured by Nippon Steel Mining Co., Ltd.), a dispersion separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.), YM micro cut (manufactured by Yaskawa Shoji Co., Ltd.) and the like.

  As a sieving device used for sieving coarse particles, Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (manufactured by Deoksugaku Kogyo Co., Ltd.); Vibrasonic system (manufactured by Dalton Co., Ltd.); Examples include a turbo screener (manufactured by Turbo Industry Co., Ltd.), a micro shifter (manufactured by Kanno Sangyo Co., Ltd.), and a circular vibrating sieve.

  Next, a batch type surface reforming apparatus suitably used in the toner production method of the present invention will be described.

  The batch type surface reforming apparatus shown in FIG. 1 includes a cylindrical main body casing 30, a top plate 43 installed so as to be openable and closable at the upper part of the main body casing; a fine powder discharge section 44 having a fine powder discharge casing and a fine powder discharge pipe; It has a cooling jacket 31 through which cooling water or antifreeze can be passed.

  Further, the batch type surface reforming apparatus shown in FIG. 1 has a plurality of dispersing hammers 33 which are square disks on the upper surface and are attached to the central rotating shaft in the main body casing 30 as surface modifying means. A distributed rotor 32 that is a disk-shaped rotating body that rotates at a high speed in a predetermined direction; a plurality of grooves are provided on the surface facing the distributed rotor 32 that are fixedly arranged around the distributed rotor 32 at a constant interval. The liner 34 is provided.

  Further, the batch type surface modification apparatus shown in FIG. 1 includes a classification rotor 35 for continuously removing fine powder having a predetermined particle size or less in the powder particles; a cold air introduction port for introducing cold air into the main body casing 30. 46: An inlet pipe having a raw material inlet 37 and a raw material inlet 39 formed on the side surface of the main casing 30 for introducing powder particles (raw material).

  1 is a product discharge pipe having a product discharge port 40 and a product extraction port 42 for discharging the toner particles after the surface modification treatment to the outside of the main body casing 30; surface modification time; Can be freely adjusted, and an openable and closable raw material supply valve 38 installed between the raw material input port 37 and the raw material supply port 39; and a product installed between the product discharge port 40 and the product extraction port 42 A discharge valve 41 is provided.

  Further, the product discharge pipe is sucked by the blower 365 in order to suck and discharge the toner particles after the surface modification treatment.

  Further, the batch type surface modification apparatus shown in FIG. 1 has a guide ring 36 as a cylindrical guide means having an axis perpendicular to the top plate 43 in the main body casing 30. The upper end of the guide ring 36 is usually provided at a predetermined distance from the top plate (usually about 20 to 50 mm), and at least a part of the classification rotor 36 is installed in a state where it is covered with the cylinder. .

  Further, the lower end of the guide ring 36 is provided at a predetermined distance from the dispersion hammer 33 which is a disk portion of the dispersion rotor 32 or a square disk. By this guide ring 36, the space between the classification rotor 35 and the dispersion rotor 32-liner 34 in the apparatus is divided into a first space 47 outside the guide ring and a second space 48 inside the guide ring. .

  Here, the first space 47 is a space for introducing the powder particles into the classification rotor 35, and the second space is a space for introducing the powder particles into the dispersion rotor.

  A gap between the dispersion hammer 33, which is a square disk installed on the dispersion rotor 32, and the liner 34 is the surface modification zone 49, and the classification rotor 35 and the peripheral portion of the rotor are the classification zone 50. .

  In the batch-type surface reforming apparatus configured as described above, with the product discharge valve 39 closed, the raw material supply valve 38 is opened, and the surface modified particles are charged from the raw material charging port 37. After a certain period of time, the raw material supply valve 38 is closed.

The powder particles introduced into the apparatus from the raw material supply port 39 are first sucked by the blower 364 and classified by the classification rotor 35. At that time, the classified fine powder having a predetermined particle size or less is continuously discharged and removed out of the apparatus through the fine powder discharge casing 44 and the fine powder discharge port 45.
The blower 364 and the blower 365 may be the same blower or may be separate blowers.

  Powder particles having a predetermined particle diameter or more are guided along the inner circumference (second space 48) of the guide ring 36 by centrifugal force, and are circulated along the circulating flow generated by the dispersion rotor 32 to the surface modification zone 49. . In generating the circulating flow, the peripheral speed of the dispersion rotor is preferably 30 m / sec to 200 m / sec, and more preferably 70 m / sec to 170 m / sec. In general, the degree of surface modification tends to increase as the peripheral speed of the dispersion rotor increases.

  The powder particles guided to the surface modification zone 49 are subjected to a mechanical impact force between the dispersion hammer 33, which is a square disk installed on the dispersion rotor 32, and the liner 34. Quality.

  The surface-modified powder particles are guided to the classification zone 50 while swirling along the outer periphery (first space 47) of the guide ring 36 along the cold air and blower suction flow passing through the machine. The fine powder is again discharged from the machine through the fine powder discharge casing 44 and the fine powder discharge port 45 by the rotor 35, and the coarse powder is returned to the surface modification zone 49 again through the circulation flow, and repeatedly performs the surface modification action. receive.

  After a predetermined time has elapsed, the product discharge valve 41 is opened, and at the same time, the surface modified particles are sucked and discharged from the product extraction port 42 by the blower 365. Here, the processing time is defined as the time from when the raw material particles are charged into the apparatus until the product discharge valve is opened. The longer the treatment time, the lower the production capacity, but the higher the surface modification degree.

  When not sucking and discharging, the surface modified particles in the apparatus are gradually discharged while repeatedly circulating in the surface modifying zone. For this reason, the degree of surface modification tends to be different between particles that are immediately discharged and particles that continue to circulate to the end and discharged immediately before the discharge valve closes. In some cases, this may cause an increase in the distribution of charge amount and may hinder various toner performance improvements.

  Furthermore, if the particles continue to circulate in the device while the discharge valve is empty, the product is targeted from the classification rotor section for continuously removing fine powder in the powder particles. The particles in the particle size region are easily discharged and removed, which tends to reduce the yield.

  That is, when the discharge valve is opened, the surface modification particles can be sucked and collected to make the degree of surface modification of the particles uniform. Furthermore, by collecting by suction, the yield can be improved and at the same time the discharge time can be shortened, and the productivity is improved by increasing the processing capacity compared with the conventional surface reforming device. It is possible.

A kneading step of melt-kneading a composition containing at least a binder resin and a colorant, a cooling step of cooling the obtained kneaded product, a step of pulverizing the cooled solidified product to obtain a finely pulverized product, and the obtained fine A step of performing a surface modification step for modifying the surface of the pulverized product to obtain toner particles,
The step of performing the surface modification step to obtain toner particles is performed using a batch type surface modification device,
When the surface modified particles are sucked and discharged from the product discharge port, it is preferable that the air volume M1 for sucking the classification rotor portion and the air volume M2 for sucking the product discharge portion satisfy the following expressions.
M1 ≧ 1.2 × M2

More preferably,
M1 ≧ 1.4 × M2
Is good.

When the air volume satisfies the above formula, it is possible to efficiently suck and collect particles having a uniform degree of surface modification. When the relationship between M1 and M2 satisfies the following equation:
M1 <1.2 × M2
That is, when the air volume in the product discharge section becomes relatively large, ultrafine particles that should be discharged and removed from the classification rotor are easily discharged from the product discharge section and easily mixed into the product, and the equivalent circle diameter is 0.25 μm or more. The ratio of the number of particles of less than 98 μm tends to be more than 12.0%, which easily causes problems due to the ultrafine powder as described above.

More preferably, it is preferable that the diameter R [m] of the dispersion rotor and the air volume M1 of the classification portion satisfy the following formula.
M1 ≧ 70 × R ³

More preferably,
M1 ≧ 90 × R ³
It is.

  When the diameter R [m] of the dispersion rotor and the air volume M1 of the classification unit satisfy the above formula, the toner in the apparatus can be circulated efficiently, and the surface modification process can proceed more uniformly. Further, the ultrafine powder is more efficiently discharged and removed than the classification rotor portion.

When the diameter R [m] of the dispersion rotor and the air volume M1 of the classification part satisfy the following formula:
M1 <70 × R ³
That is, when the air volume M1 of the classification part is small compared to the size of the dispersion rotor, the particles cannot be circulated well to the vicinity of the classification rotor, or the particles are not well dispersed in the apparatus, and the surface modification treatment is performed. Tends to be non-uniform. Further, it tends to be difficult to discharge and remove ultrafine powder from the classification rotor portion, and the ratio of the number of particles having an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm tends to be more than 12.0%. Prone to problems caused by fines.

On the other hand, it is preferable that the air volume M2 of the product discharge portion satisfies the following formula.
M2 ≧ 5 × R ³

  When M2 satisfies the above formula, the surface-modified particles can be efficiently sucked and collected. At the time of suction recovery, particles may be sent to the next process by the wind indicating M2, and while the product discharge valve is closed, the outside of the product discharge valve is moved into the surface reformer by the wind indicating M2. By making negative pressure in comparison, after the product discharge valve is opened due to the pressure difference and the product is discharged at the same time, the particles may be sent to the next process by a toner transport means (not shown) separately installed immediately after the discharge valve. .

In the present invention, a magnetic material may be contained as a colorant. In particular, the content is adjusted so that the true density (g / cm ³ ) of the toner particles is 1.50 or more and 2.00 or less. It is preferable to do. In other words, by setting the true density of the toner particles within the above range, as described above, the circulation of the toner particles in the surface reforming apparatus is easy to work efficiently and the surface modification of the toner is easily performed uniformly. Rather, when the product discharge valve is opened and the product is sucked and collected, the self-weight of the toner works effectively in the balance of air volume of M1 and M2, and the ultrafine powder is mixed into the excessive product. It is easy to suppress a decrease in the uniformity of processing.

  Further, by using a magnetic toner, the use of the one-component development method eliminates the need for a carrier, which is advantageous in terms of downsizing the apparatus.

  When the toner of the present invention is a magnetic toner, for example, a developing device for one-component jumping development, or a developing and cleaning device that supplies (develops) magnetic toner to the photosensitive member and collects transfer residual toner from the photosensitive member Can be used for image formation using a known image forming apparatus for a one-component developer. Further, it can be suitably used for a process cartridge that has at least a developing device that accommodates toner and an electrostatic latent image carrier that is developed as a toner image and is integrally attached to the main body of the image forming apparatus.

  The toner carrier preferably used for carrying the toner of the present invention is preferably a conductive cylinder formed of a metal or alloy such as aluminum or stainless steel. A conductive cylinder may be formed of a resin composition having sufficient mechanical strength and conductivity, and a conductive rubber roller may be used. Moreover, it is not limited to a cylindrical shape, and may be in the form of an endless belt that is rotationally driven.

  In particular, since toner charge control is easy, a mode in which the surface of the toner carrier is coated with a resin layer in which conductive fine particles and / or a lubricant are dispersed is preferable.

  Examples of the resin used for the resin layer include thermoplastic resins such as styrene resins, vinyl resins, polyethersulfone resins, polycarbonate resins, polyphenylene oxide resins, polyamide resins, fluororesins, fiber resins, and acrylic resins; Thermosetting resins or photocurable resins such as epoxy resins, polyester resins, alkyd resins, phenol resins, melamine resins, polyurethane resins, urea resins, silicone resins, and polyimide resins can be used.

  Among them, those having releasability such as silicone resin and fluorine resin, or mechanical properties such as polyethersulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, phenol resin, polyester resin, polyurethane resin, styrene resin The thing excellent in is more preferable.

  As the conductive fine particles to be contained in the resin layer, conductive metal oxides such as carbon black, graphite, and conductive zinc oxide and metal double oxides are used alone or in combination of two or more.

  The surface roughness of the toner carrier used in the present invention is preferably in the range of 0.2 to 3.5 μm in terms of JIS centerline average roughness (Ra). If Ra is less than 0.2 μm, the amount of charge on the toner carrying member tends to be high, and the developability tends to be insufficient. When Ra exceeds 3.5 μm, unevenness occurs in the toner coat layer on the toner carrying member, and there is a tendency that density unevenness occurs on the image. More preferably, it is in the range of 0.2 to 3.0 μm. In the present invention, Ra is a centerline average roughness measured using a surface roughness measuring instrument (Surfcoder SE-30H, manufactured by Kosaka Laboratory Ltd.) based on JIS surface roughness “JIS B 0601”. It corresponds to.

  The Ra can be adjusted to the above range by changing the polishing state of the surface layer of the toner carrier, or adding spherical carbon particles, carbon fine particles, graphite or the like.

  Further, it is preferable that the toner carrier has a fixed magnet having multiple poles, and the magnetic poles have 3 to 10 poles.

  The diameter of the toner carrier is appropriately selected from about Φ10 to about Φ30 depending on the machine speed, and the magnetic pole strength is appropriately determined depending on the balance between the machine speed, the developing sleeve diameter, and the magnetic toner developability. The In order to suppress the generation of long spikes of magnetic toner in the developing unit, both the magnetic pole of the developing unit and the magnetic pole of the toner amount regulating unit are preferably 1000 gauss (0.1 Tesla) or less.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

<Measurement of average circularity of toner particles>
The average circularity of the toner particles was measured with a flow type particle image analyzer “FPIA-3000 type” (manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  As a specific measurement method, a suitable amount of a surfactant, preferably an alkylbenzene sulfonate, is added to 20 ml of ion-exchanged water, and then 0.06 g of a measurement sample is added, and an oscillation frequency of 50 kHz and an electric output of 150 W is added. Dispersion treatment was carried out for 2 minutes using a desktop type ultrasonic cleaner / disperser (for example, “VS-150” (manufactured by VervoCrea Co., Ltd.)) to obtain a dispersion for measurement. It cools suitably so that it may become 10 to 40 degreeC.

  For the measurement, the flow type particle image analyzer equipped with a high-magnification imaging unit (objective lens (20 ×)) was used, and the particle sheath “PSE-900A” (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 2000 toner particles are measured in the total count mode in the HPF measurement mode, and the binarization threshold at the time of particle analysis is 85%. It was. The analysis particle diameter was limited to a circle equivalent diameter of 1.98 μm or more and less than 30.0 μm, or an equivalent diameter of 0.25 μm or more and less than 30.0 μm, and the average circularity and the ratio of ultrafine powder were calculated.

  In measurement, automatic focus adjustment is performed using standard latex particles (for example, Duke Scientific 5100A diluted with ion-exchanged water) before the start of measurement. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples of the present application, a calibration work by Sysmex Corporation was performed, a flow type particle image analyzer that received a calibration certificate issued by Sysmex Corporation was used, except that the analysis particle diameter was limited. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received.

(Binder resin production example)
(Polyester resin production example 1)
The polyester monomer is mixed in the following ratio.
-Bisphenol derivative represented by formula (A) (R: propylene group 2.2 mol addition)
1.150 mol
・ Terephthalic acid 0.430 mol
・ Isophthalic acid 0.390 mol
・ Fumaric acid 0.010 mol
・ Dodecenyl succinic anhydride 0.170 mol
Tetrabutyl titanate 0.1 mass% was added to these as a catalyst, and condensation polymerization was carried out at 220 ° C. to obtain unsaturated polyester resin P-1 (Tg 58 ° C., peak molecular weight = 7800, number average molecular weight = 4600, Mw / Mn = 2.1, acid value = 5, hydroxyl value = 37).

(Polyester resin production example 2)
Unsaturated polyester resin P-2 (Tg 60 ° C., peak molecular weight = 4500, number average molecular weight = 2900, Mw / Mn = 5.4) in the same manner as in polyester resin production example 1 except that the polyester monomer is mixed in the following ratio. Acid value = 27, hydroxyl value = 69).
-Bisphenol derivative represented by formula (A) (R: propylene group 2.2 mol addition)
1.150 mol
・ Terephthalic acid 0.370 mol
・ Isophthalic acid 0.290 mol
・ Fumaric acid 0.080 mol
・ Dodecenyl succinic anhydride 0.200 mol
・ Trimellitic acid 0.060 mol

(Polyester resin production example 3)
Saturated polyester resin P-3 (Tg 56 ° C., peak molecular weight = 7500, number average molecular weight = 5100, Mw / Mn = 2.4, except that the polyester monomer is mixed in the following ratio) Acid value = 5, hydroxyl value = 41) was obtained.
-Bisphenol derivative represented by formula (A) (R: propylene group 2.2 mol addition)
1.150 mol
・ Terephthalic acid 0.430 mol
・ Isophthalic acid 0.400 mol
・ Dodecenyl succinic anhydride 0.170 mol

(Hybrid resin production example 1)
Unsaturated polyester resin P-1: 75 parts by mass, vinyl monomer as styrene: 18 parts by mass, butyl acrylate: 6.5 parts by mass, monobutyl maleate: 0.5 parts by mass, initiator as 2,5 -Dimethyl-2,5-bis (t-butylperoxy) hexyne-3 (10-hour half-life temperature 128.4 ° C): 0.08 parts by mass were mixed. After this vinyl monomer / polyester resin mixture was polymerized at 120 ° C. for 20 hours, the temperature was further raised to 150 ° C. and held for 5 hours to polymerize the unreacted vinyl monomer to obtain a hybrid resin. This is designated as binder resin 1. This resin had a main peak molecular weight of 7200 in the GPC molecular weight distribution of THF-soluble matter, contained 8 area% of components having a molecular weight in the range of 40,000 to 1,000,000, and contained 21 mass% of chloroform-insoluble matter. .

(Hybrid resin production example 2)
Unsaturated polyester resin P-2: 55 parts by mass, vinyl monomer as styrene: 30 parts by mass, butyl acrylate: 15 parts by mass, initiator as 2,5-dimethyl-2,5-bis (t-butyl Peroxy) hexyne-3: 0.15 part by mass was mixed. A hybrid resin was obtained using this vinyl monomer / polyester resin mixture in the same manner as in Hybrid Resin Production Example 1. This is designated as binder resin 2. This resin had a main peak molecular weight of 4300 in a GPC molecular weight distribution of THF-soluble matter, contained 37 area% of components having a molecular weight in the range of 40,000 to 1,000,000, and contained 41 mass% of chloroform-insoluble matter. .

(Hybrid resin production example 3)
Saturated polyester resin P-3: 75 parts by weight, vinyl monomer as styrene: 18 parts by weight, butyl acrylate: 7 parts by weight, initiator as 2,5-dimethyl-2,5-bis (t-butyl par Oxy) hexyne-3: 0.08 part by mass was mixed. After this vinyl monomer / polyester resin mixture was polymerized at 120 ° C. for 20 hours, the temperature was further raised to 150 ° C. and held for 5 hours to polymerize the unreacted vinyl monomer, whereby a binder resin 3 was obtained. This resin had a main peak molecular weight of 7500 in a GPC molecular weight distribution of THF-soluble matter, contained 28 area% of components having a molecular weight in the range of 40,000 to 1,000,000, and contained no chloroform-insoluble matter.

(Magnetic toner production example 1)
Binder resin 1: 100 parts by mass Wax: 5 parts by mass (low molecular weight polyethylene, DSC peak = 102 ° C., Mn = 850)
Magnetic iron oxide: 95 parts by mass (composition: Fe ₃ O ₄ , shape: spherical, average particle size 0.21 μm, magnetic properties at 795.8 kA / m; Hc = 5.4 kA / m, σs = 83.8 Am ² / Kg, σr = 7.0 Am ² / kg)
-T-77 (manufactured by Hodogaya Chemical Co., Ltd.): 2 parts by mass The above raw materials were premixed with a Henschel mixer and then kneaded with a twin-screw kneading extruder set at 130 ° C and 200 rpm. The obtained kneaded product is cooled and coarsely pulverized with a cutter mill, and then the obtained coarsely pulverized product is heated to an air temperature of 45 ° C. using a turbo mill T-250 (manufactured by Turbo Kogyo Co., Ltd.). The mixture was finely pulverized and classified using a multi-division classifier utilizing the Coanda effect to obtain particles 1 having a weight average particle diameter (D4) of 6.0 μm.

The particles 1 were put into a surface modification apparatus shown in FIG. 1 equipped with a dispersion rotor having a diameter of 300 mm and subjected to a surface modification treatment. At this time, the peripheral speed of the dispersion rotor was 120 m / sec, and the processing time from when the particles 1 were supplied into the apparatus until the discharge valve was opened was set to 20 seconds. Further, the air volume M1 of the classification part when discharging the surface-modified particles from the product discharge part was 3.5 m ³ / min, and the air volume M2 of the product discharge part was 1.6 m ³ / min.

  Table 2 shows the physical properties of the surface-modified magnetic toner particles 1.

Further, 100 parts by mass of the magnetic toner particles 1 and 1.2 parts by mass of hydrophobic silica fine powder obtained by subjecting dry silica (BET: 200 m ² / g) to hexamethyldisilazane treatment and then dimethyl silicone oil treatment, Were mixed with a Henschel mixer to prepare Magnetic Toner 1.

(Magnetic toner production examples 2 to 6, 8)
In the magnetic toner production example 1, in the pulverization and classification processes, the weight average particle diameter of the toner particles is adjusted, the binder resin is changed as shown in Table 1, and the conditions of the surface reformer are changed. In the same manner, magnetic toner particles 2 to 6 and 8 were obtained. Table 2 shows the physical properties of these magnetic toner particles.

  Further, in the same manner as in magnetic toner production example 1, dry silica was mixed to obtain magnetic toners 2 to 6 and 8.

(Magnetic toner production example 7)
In the magnetic toner production example 1, the classification process was performed twice, the weight average particle diameter of the toner particles was adjusted in the pulverization and classification process, and the binder resin was changed as shown in Table 1 to improve the surface. Magnetic toner particles 7 were obtained in the same manner except that the conditions of the quality device were changed. Table 2 shows the physical properties of the magnetic toner particles 7.

  Further, in the same manner as in magnetic toner production example 1, magnetic silica 7 was obtained by mixing dry silica.

(Magnetic toner production example 9)
In magnetic toner production example 1, particles 2 having a weight average particle diameter (D4) of 6.5 μm were obtained in the same manner as in production example 1 except that the weight average particle diameter of the toner particles was adjusted in the pulverization and classification process. . A small amount of fine powder sucked and removed from the classification part in the surface modification step of Production Example 1 was added to Particle 2 to obtain Particle 3. The ratio of the number of particles having an equivalent circle diameter of 0.25 μm to less than 1.98 μm with respect to the number of particles having an equivalent circle diameter of 0.25 μm to less than 30.0 μm was measured to be 14.1%. 100 parts by mass of the particles 3 and 1.2 parts by mass of a hydrophobic silica fine powder obtained by subjecting dry silica (BET: 200 m ² / g) to hexamethyldisilazane treatment and then dimethylsilicone oil treatment were used. To prepare a magnetic toner 9.

(Magnetic toner production example 10)
In the magnetic toner production example 1, in the pulverization and classification process, the weight average particle diameter of the toner particles is adjusted, the exhaust temperature of the turbo mill T-250 is 55 ° C., and the classification process is performed twice, as shown in Table 1. In addition, the magnetic toner particles 10 were obtained in the same manner except that the binder resin was changed and the conditions of the surface modification device were changed. Table 2 shows the physical properties of the magnetic toner particles 10. Further, in the same manner as in magnetic toner production example 1, dry silica was mixed to obtain magnetic toner 10.

[Example 1]
(Evaluation 1)
A commercially available LBP printer (Laser Jet 4300, manufactured by HP) was modified to obtain A4 size 65 sheets / minute.

  To this modified machine, the magnetic toner 1 obtained in the toner production example 1 is filled, and the toner carrying member has a magnet with a developing pole of 750 gauss inside, and the surface roughness Ra is 1.0 μm. A modified process cartridge in which a sleeve having a diameter of Φ20 was incorporated and the capacity of the toner filling portion was doubled was mounted.

Using this as an image tester, after leaving overnight in a high-temperature and high-humidity environment of 32.5 ° C. and 85% RH, a horizontal line pattern with a printing rate of 4% is taken as one sheet / job, and between jobs. A print durability test of 30,000 sheets was performed using A4 plain paper (75 g / m ² ) in a mode in which the machine was once stopped and the next job was started.

  The following evaluation was performed during this print durability test or after a durability test of 30,000 sheets.

  The image density was measured and evaluated by measuring the reflection density of a 5 mm square solid black image using an SPI filter with a Macbeth densitometer (Macbeth Co., Ltd.), which is a reflection densitometer.

  The evaluation standard of image density is shown below.

As a result of calculating the reduction rate of the reflection density after 30,000 sheets endurance with respect to 1000 sheets endurance,
A: The decrease rate is less than 2%.
B: The decrease rate is 2% or more and less than 3%.
C: The decrease rate is 3% or more and less than 5%.
D: The reduction rate is 5% or more.

The evaluation criteria for streaks are shown below.
A: No streak occurs after 30,000 sheets.
B: Some streaks occur up to 30,000 sheets.
C: Streaks occur up to 20,000 sheets.
D: Streaks occur up to 10,000 sheets.

During the durability test under the H / H environment, the transfer efficiency was confirmed when 20000 sheets were durable. A solid image having an image paste amount of 0.60 mg / cm ² was developed on a drum and then transferred to A4 plain paper (75 g / m ² ) to obtain an unfixed image. The transfer efficiency was determined from the change in weight between the toner amount on the drum and the toner amount on the transfer paper (the transfer efficiency is 100% when the entire toner amount on the drum is transferred onto the transfer paper).
A: Transfer efficiency is 95% or more B: Transfer efficiency is 90% or more and less than 95% C: Transfer efficiency is 85% or more and less than 90% D: Transfer efficiency is 80% or more and less than 85%

(Evaluation 2)
Next, the image line tester used in Evaluation 1 was left overnight in a low-temperature and low-humidity environment at 15 ° C. and 10% RH. In a mode in which the machine was temporarily stopped during this period and the next job started, 30,000 print durability tests were performed using A4 plain paper (90 g / m ² ).

  The image characteristics shown below were evaluated during this print durability test or after a durability test of 30,000 sheets.

  For the fogging, during the endurance test, at the end of 10,000 sheets, the amplitude of the AC component of the developing bias is set to 1.7 kV (default is 1.6 kV), two solid whites are printed, and the second sheet is covered. It measured by the following method.

  Using a reflection densitometer (reflectometer model TC-6DS manufactured by Tokyo Denshoku Co., Ltd.), the transfer material before and after the image formation is measured, the reflection density worst value after the image formation is Ds, and the reflection average density of the transfer material before the image formation. Was Dr, Ds-Dr was determined, and this was evaluated as the fogging amount. The results are shown in Table 3.

The evaluation criteria for fogging are shown below.
A: Less than 1.0.
B: 1.0 or more and less than 2.0.
C: 2.0 or more and less than 3.5.
D: 3.5 or more.

During the endurance test, splattering was evaluated by visual observation of toner splatter around the character when printed on cardboard (105 g / m ² ) following the evaluation of the fog at the end of 10,000 sheets. As a result, almost no scattering was observed, and a sharp character image was obtained. The results are shown in Table 3.

The evaluation criteria for scattering are shown below.
A: It is hardly seen.
B: Slight splattering is seen but I don't mind.
C: Slightly much scattering and may be a concern, but there is no problem in practical use.
D: Some characters are so scattered that they cannot be read.

  The blotch was evaluated as follows.

  In the image forming test machine used in Evaluation 1, the contact pressure of the developing blade that regulates the toner coat layer on the developing sleeve is 70%, and the image ratio is 2% in a low-temperature and low-humidity environment of 15 ° C. and 10% RH. After copying 100 line images, the toner coat state on the developing sleeve was visually observed, and the occurrence of blotch was evaluated based on the following evaluation criteria.

The evaluation criteria of blotch are shown below.
A: Blotch is not generated at all B: Blotch is slightly generated at the end of the sleeve C: Blotch is generated slightly but does not affect the image D: Blotch is clearly generated and image Affects

The charging member contamination was evaluated after a print test of 30,000 sheets. The evaluation criteria are shown below. (AC weakening?)
A: Although the charging member was visually confirmed, it was not soiled at all.
B: The charging member is slightly dirty, but there is no problem on the image.
C: The charging member is dirty and streaks due to poor charging are seen in the halftone image, but there is no problem in practical use.
D: The charging member is dirty and the end of the character image is dirty.

(Evaluation 3)
The image-drawing tester and process cartridge used in Evaluation 1 were left overnight in a normal temperature and humidity environment of 23 ° C. and 50% RH. The process cartridge was previously filled with the magnetic toner 1 by weighing the empty weight of the toner filling portion. After leaving overnight, 5000 character patterns with a printing rate of 4% were continuously printed on A4 plain paper (75 g / m ² ). Subsequently, after measuring the weight of the toner filling portion and recording the toner weight in the container, 20,000 character patterns having a printing rate of 4% were continuously printed, the weight of the toner filling portion was measured again, and the toner in the container was measured. The average toner consumption (mg / sheet) at the time of printing 20,000 sheets was calculated by the procedure of calculating the weight reduction amount. The results are shown in Table 3.

It is explanatory drawing of the palindromic surface modification apparatus used suitably for the manufacturing method of the toner of this invention.

Explanation of symbols

30 Main body casing 32 Distributed rotor 35 Classification rotor

Claims (8)

In toner particles containing at least a binder resin and a colorant, and toner containing inorganic fine particles,
The toner particles have a weight average particle diameter (D4) of 4.0 μm to 7.5 μm,
In the flow type particle image measuring apparatus having an image processing resolution of 512 × 512 pixels (0.19 μm × 0.19 μm per pixel),
1) The average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.940 or more and 0.970 or less,
2) The ratio of the number of particles with an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm to the number of particles with an equivalent circle diameter of 0.25 μm or more and less than 30.0 μm is 1.0% or more and 12.0% or less,
3) The difference between the average circularity at an equivalent circle diameter of 0.25 μm or more and less than 1.98 μm and the average circularity at an equivalent circle diameter of 1.98 μm or more and less than 30.0 μm is 0.020 or less. toner.   2. The toner according to claim 1, wherein the toner particles have a circularity variation coefficient (CV value) of 9.0 or less when the equivalent circle diameter is 0.25 μm or more and less than 1.98 μm.   The toner according to claim 1, wherein the binder resin contains at least a polyester unit.   The binder resin contains a hybrid resin in which a polyester resin component and a vinyl resin component are chemically bonded, and the binder resin contains 50% by mass or more of a polyester resin component. The toner according to claim 1. The toner contains 3 to 50% by mass of a chloroform-insoluble component derived from a binder resin, the chloroform-insoluble component contains a hybrid resin, and the THF-soluble component of the vinyl resin component contained in the chloroform-insoluble component. The toner according to claim 1, wherein the toner has a main peak in a molecular weight range of 5.0 × 10 ^{4 to} 5.0 × 10 ^{6 in} a GPC molecular weight distribution. 6. The toner particles according to claim 1, wherein the toner particles contain a magnetic material as a colorant, and the true density (g / cm ³ ) of the toner particles is 1.50 or more and 2.00 or less. The toner described. A kneading step of melt-kneading a composition containing at least a binder resin and a colorant, a cooling step of cooling the obtained kneaded product, a step of pulverizing the cooled solidified product to obtain a finely pulverized product, and the obtained fine A step of performing a surface modification step for modifying the surface of the pulverized product to obtain toner particles,
The step of performing the surface modification step to obtain toner particles is performed using a batch type surface modification device,
The surface modification step performs a surface modification step for performing surface modification of particles contained in the obtained finely pulverized product and a classification for removing the fine powder contained in the obtained finely pulverized product by suction. After performing the classification process at the same time, it has a discharge process of sucking and discharging from the product discharge part,
A method for producing toner, characterized in that, when discharging particles whose surface has been modified from a product discharge portion, an air volume M1 for sucking the classification portion and an air volume M2 for sucking the discharge portion satisfy the following expressions.
M1 ≧ 1.2 × M2 The surface modification device has at least a dispersion rotor for performing a surface modification treatment using a mechanical impact force, and a liner that is a fixed body arranged at a constant interval on the outer periphery of the dispersion rotor. And
The toner manufacturing method according to claim 7, wherein the diameter R [m] of the dispersion rotor and the air volume M1 sucking the classification portion satisfy the following formula.
M1 ≧ 70 × R ³

Images