JP4095526B2 - toner - Google Patents

Description

  The present invention relates to a toner used in an image forming method such as an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and a toner jet recording method.

  Numerous proposals have been made regarding techniques for improving the developability and durability of a toner by controlling the hydrophobic properties of the toner with respect to a specific solvent. As such a technique, the toner is dispersed in an ethanol / water mixed solution, the absorbance at that time is measured, and the amount of magnetic iron oxide present on the surface of the magnetic toner is known, whereby the charging roller caused by the magnetic toner is obtained. There is known a technique that can easily know how much dirt or fusing of magnetic toner to a photosensitive drum occurs (see, for example, Patent Document 1). Further, as the above technique, a technique relating to a toner having a certain wetting characteristic with respect to ethanol is known by measuring the transmittance with respect to the ethanol content by expressing the hydrophobic characteristics of the toner with an ethanol dropping transmittance curve. (For example, refer to Patent Document 2). Also known is a technique for improving the charging characteristics of a toner by dispersing the toner in a methanol / water mixed solution and associating the absorbance at that time with the surface state of the magnetic toner (see, for example, Patent Document 3).

  However, just satisfying these characteristics, fixing problems such as edge offset, which has become a problem with the recent increase in the speed of electrophotographic apparatuses, reduction in image density due to toner charge-up phenomenon, etc. It is difficult to deal with all of many problems.

As a polyester resin for toner, a ratio of an ultrahigh molecular weight body having a tetrahydrofuran (THF) insoluble content of 5% by mass or less and a THF soluble content of 1 × 10 ⁶ or more, and a high molecular weight body having 1 × 10 ⁵ or more. A polyester resin for toner is known in which a ratio of a low molecular weight body in a region of less than 1 × 10 ⁴ and a ratio of a medium molecular weight body of 1 × 10 ⁴ or more and less than 1 × 10 ⁵ are defined (for example, Patent Documents). 4 and 5). However, it is difficult to solve the end offset only by defining the component amount of each fractional molecular weight of the polyester resin.

The polyester resin for toner has a maximum molecular weight in the region of 1 × 10 ³ or more and 8 × 10 ³ or less, Mw / Mn is 20 or more and 200 or less, and the molecular weight of the entire resin is 1 × 10. ^A polyester-based resin for an electrophotographic toner having a ratio of ⁵ or less of 80% by mass or more and containing a trivalent or higher polyvalent carboxylic acid and / or a trivalent or higher polyhydric alcohol is known. (For example, refer to Patent Document 6). According to this, it is possible to obtain a toner having a wide non-offset temperature range, but the charge control of the toner is insufficient and it is difficult to cope with the increase in speed.

  Further, as a toner containing a polyester resin, a toner containing a polyester resin using an oxyalkylene ether of a novolak type phenol resin is known (for example, see Patent Documents 7 and 8). However, since the polyester resin is characterized by not containing tetrahydrofuran-insoluble matter, it is difficult to satisfy high-temperature offset property and developability at a high level.

As a toner binder polyester resin, a toner binder polyester resin using an oxyalkylene ether of a novolac-type phenol resin is known (for example, see Patent Document 9). As for the toner, it is a polyester resin composed of a polyvalent carboxylic acid component and a polyhydric polyol component, and at least a part of the polyhydric polyol component is an oxyalkylene ether of a trivalent or higher novolak type phenol resin, and is insoluble in THF. There is known a toner containing a resin containing 0.1 to 20% by mass (for example, see Patent Document 10). According to these inventions, although the problems of fixing property and high temperature offset property are certainly improved, since the hydrophobicity of the toner is not controlled, the toner characteristics are largely dependent on the environment, and there is still room for improvement. .
JP 11-194533 A JP 2000-242027 A EP1241530A1 Japanese Patent Laid-Open No. 10-60104 JP-A-10-69126 JP-A-9-251216 JP-A-9-251217 JP-A-11-24312 JP-A-5-27478 JP 2000-243030 A

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

  An object of the present invention is to provide a toner capable of suppressing a decrease in image density after being left in a high temperature and high humidity environment and a decrease in image density due to a charge-up phenomenon when printing at a low printing rate. is there.

  Another object of the present invention is to provide a toner that is excellent in fixing property and high-temperature offset property and can suppress the occurrence of edge offset.

  The present invention relates to a toner having toner particles containing at least a binder resin containing a polyester resin as a main component, a wax, and a colorant, and the wettability of the toner with respect to a mixed solvent of methanol and water. , When the transmittance is 80%, the methanol concentration is in the range of 45 to 65% by volume, and when the transmittance is 10%, the methanol concentration is in the range of 45 to 65% by volume, The toner has a melt index of 0.1 to 10 g / 10 min at 125 ° C. under a load of 5 kg and contains 5 to 40% by mass of a resin component insoluble in tetrahydrofuran with respect to the binder resin. In the chromatogram measured by permeation chromatography, the molecular weight ranged from 3000 to 20,000. Has an in-peak, and a molecular weight in tetrahydrofuran soluble portion relates to a toner ratio of 10,000 or less of component is 50 mass% or more.

  The toner of the present invention contains at least a binder resin containing a polyester resin as a main component and a colorant. When the wettability of the toner with respect to a mixed solvent of methanol and water is measured by the transmittance of light having a wavelength of 780 nm, When the rate is 80%, the methanol concentration is in the range of 45 to 65% by volume, and when the transmittance is 10%, the methanol concentration is in the range of 45 to 65% by volume. The toner has a melt index of 0.1 to 10 g / 10 min, contains an organic component insoluble in tetrahydrofuran in an amount of 5 to 40% by mass with respect to the binder resin, and the tetrahydrofuran soluble content of the toner is measured by gel permeation chromatography. The chromatogram has a main peak in the molecular weight region of 3000 to 20,000, and tetrahydro Since the proportion of the component having a molecular weight of 10,000 or less in the run-soluble component is 50% by mass or more, according to the present invention, the fixing property and the high temperature offset property are excellent, and the image after being left in a high temperature and high humidity environment. It is possible to provide a toner that prevents a decrease in image density due to a decrease in density or a charge-up phenomenon during printing at a low printing rate, and that does not cause edge offset or tailing.

  In the present invention, the polyester resin has a low molecular weight polyester component having a main peak molecular weight of 3000 to 20,000 and having a tetrahydrofuran insoluble content of 0 to 3% by mass and a tetrahydrofuran insoluble content of 10 to 60% by mass. And having a mass ratio of the crosslinked polyester component to the low molecular weight polyester component of 10:90 to 90:10, such as hydrophobic properties, fixability, high temperature offset property, and developability, This is even more effective in appropriately controlling the balance of various characteristics of the toner.

  In the present invention, when the melt index of the crosslinked polyester component at 190 ° C. and 10 kg load is 0.1 to 10 g / 10 min, various properties of the toner such as developability, fixability, high temperature offset property, and edge offset property It is even more effective in increasing

  In the present invention, when the cross-linked polyester component contains a trivalent or higher polyvalent carboxylic acid and a trivalent or higher polyhydric alcohol as the monomer component, the wettability of the toner is appropriately controlled, and the end portion More effective in suppressing offset and charge-up, trihydric or higher polyhydric alcohol is an oxyalkylene ether of novolac type phenol resin, trihydric or higher polyhydric carboxylic acid is trimellitic acid, Even more effective.

  In the present invention, 0.1 to 5 parts by mass of an aluminum aromatic hydroxycarboxylic acid compound with respect to 100 parts by mass of the binder resin, and 0.1 to 10 parts by mass of a monoazo iron compound with respect to 100 parts by mass of the binder resin; When it contains, it is much more effective in preventing toner charge-up and reducing environmental fluctuations in toner charging.

  In the present invention, the inclusion of 30 to 200 parts by mass of the magnetic material with respect to 100 parts by mass of the binder resin is more effective in constructing the magnetic toner having the above-described excellent effects.

  When speeding up an electrophotographic device, it is necessary to increase the set temperature of the fixing unit to ensure sufficient fixing performance, but printing is performed in a mode that tends to accumulate heat in the machine, such as continuous duplex printing. As a result, the temperature inside the machine becomes very high (temperature rise inside the machine). For this reason, the relative humidity in the machine is lowered and the machine becomes dry. As a result, the amount of water adsorbed on the surface of the toner particles becomes extremely small, so that the charge of the toner is hardly leaked, and the toner is likely to be charged excessively. If image output with a low printing rate is continued in this state, little toner is consumed on the developing sleeve and stays on the sleeve for a long time, increasing the chance of friction with the developing sleeve and the developing blade. A problem called charge-up occurs in which the image density becomes too high and the image density becomes low.

  In addition to this problem, by setting the fixing temperature high, a problem called end offset is likely to occur. To explain this, when small-size paper (for example, postcards) is continuously passed, the fixing nip portion near the center of the fixing device is deprived of heat by the paper, so the temperature does not increase greatly. The non-sheet passing portion of the portion stores heat because the heat is not taken away by the paper, and the temperature of the fixing nip portion becomes very high. When normal size paper (for example, A4) is passed in this state, there arises a problem that only the edge of the paper is offset (edge offset).

  This is different from the high temperature offset phenomenon that occurs when the toner viscosity is simply lowered by heat and the toner is peeled off from the paper, and the water contained in the paper is instantly evaporated at the overheated nip. However, since the toner image developed on the paper is lifted off the paper, the adhesiveness between the paper and the toner is deteriorated, and the toner is transferred to the heating roller side. In particular, when the speed of the fixing device using the film heating method is increased, the pressing force cannot be set as high as the heat roll method, and the force of pressing the toner against the paper is small. Prone to become prominent.

  As described above, since the edge offset generation mechanism is caused by a high-temperature fixing device, the toner has a sufficient high-temperature offset property and further improves the problem of the edge offset property. It is necessary to have physical properties to do. In other words, since the edge offset is different from the high temperature offset, it is possible to increase the melt viscosity and elasticity of the toner, or to include a releasing component such as wax, as in the method usually used to improve the problem of the high temperature offset. This is not enough to improve the end offset.

  As a result of intensive studies by the present inventors in order to improve the problems of charge-up and edge offset that occur with the increase in the speed of the image forming apparatus main body, a mixture of methanol and water in a toner containing a polyester resin is obtained. Solvent wettability, toner melt index (hereinafter also referred to as “MI”), toner tetrahydrofuran (hereinafter also referred to as “THF”) insoluble organic component amount, and molecular weight distribution of THF soluble content in the toner. It was found that the above-mentioned problems can be solved by controlling.

  The wettability of the toner to the mixed solvent of methanol and water is a parameter indicating the degree of hydrophobicity of the toner surface. The higher the methanol ratio, the higher the hydrophobicity, and the lower the methanol ratio, the higher the hydrophobicity. Indicates low hydrophobicity.

  For charge-up and edge offset, when the wettability of the polyester-containing toner to the mixed solvent of methanol and water is measured by the transmittance of light with a wavelength of 780 nm, the methanol concentration when the transmittance is 80% Is 45 to 65% by volume, and the effect is exhibited when the methanol concentration is 45 to 65% by volume when the transmittance is 10%.

  Polyester resin has acid groups or hydroxyl groups at all molecular terminals, so it has high affinity with paper, and the toner adheres strongly to the paper, making it difficult for the toner to lift from the paper even if vapor is generated from the paper. It is effective and suppresses end offset. Further, by setting the wettability of the toner containing the polyester resin to the mixed solvent of methanol and water within the above range, the degree of hydrophobicity of the toner is controlled to an appropriate range, and the affinity with paper can be further increased. This has the effect of dramatically improving the problem of end offset.

  In addition, by controlling the hydrophobicity of the toner to an appropriate range without excessively increasing, the polyester resin present on the surface of the toner particles can adsorb moisture appropriately even when the humidity drops due to temperature rise in the machine. Therefore, excessive charging of the toner can be leaked, and charging up can be suppressed.

  On the other hand, if the degree of hydrophobicity of the toner is too low, the toner tends to absorb moisture, and if left in a high-humidity environment, the amount of charge becomes too low and the image density becomes low. For this reason, it is not preferable to reduce the degree of hydrophobicity too much.

  In other words, the present invention is different from the conventional technique which simply aims to increase the hydrophobicity of the toner in that the hydrophobicity of the toner is controlled within an appropriate range.

  When the wettability of the toner to the mixed solvent of methanol and water is measured by the transmittance of light having a wavelength of 780 nm, the methanol concentration when the transmittance is 80% exceeds 65% by volume, or the transmittance is 10%. When the methanol concentration of the toner exceeds 65% by volume, the hydrophobicity of the toner is too high, the affinity between the toner and the paper is lowered, the edge offset is deteriorated, and the image density is lowered due to charge-up. It is easy to happen.

  When the wettability of the toner to the mixed solvent of methanol and water is measured by the transmittance of light having a wavelength of 780 nm, the methanol concentration when the transmittance is 80% is less than 45% by volume, or when the transmittance is 10%. When the methanol concentration is less than 45% by volume, the hydrophobicity of the toner becomes too low. Therefore, if the toner is left in a high humidity environment, the toner absorbs moisture and is less likely to be charged, and the image density is likely to decrease.

  In the present invention, from the viewpoint of further enhancing the above-described effects, when the wettability of the toner with respect to the mixed solvent of methanol and water is measured by the transmittance of light having a wavelength of 780 nm, the methanol concentration when the transmittance is 80% is obtained. It is preferable that the methanol concentration is in the range of 50% by volume or more and less than 65% by volume, and the methanol concentration when the transmittance is 10% is in the range of 50% by volume or more and less than 65% by volume. It is more preferable that the methanol concentration when it is% is 55 to 64% by volume, and the methanol concentration when the transmittance is 10% is 60% or more and less than 65% by volume.

  The toner of the present invention has an MI of 125 ° C. and a 5 kg load of 0.1 to 10 g / 10 min, contains 5 to 40% by mass of tetrahydrofuran (THF) insoluble in the binder resin, and the toner is soluble in THF. In the chromatogram obtained by measuring the fraction by gel permeation chromatography (GPC), the proportion of the component having a main peak in the molecular weight region of 3000 to 20,000 and having a molecular weight of 10,000 or less in the THF-soluble component is 50 mass. % Or more.

  In order to control the wettability of the toner to the mixed solvent of methanol and water, it is necessary to precisely control the state of the toner particle surface, in particular, the state of exposure to the surface of the toner particle such as wax and colorant. By setting the MI, THF insoluble content, and GPC chromatogram of the toner within the above ranges, the toner has a melt viscosity suitable for finely dispersing the raw material in the melt-kneading process. It becomes uniform and it becomes easy to control the wettability of the toner to the mixed solvent of methanol and water. At the same time, suitable characteristics can be obtained from the standpoint of fixability and chargeability.

  In the present invention, the relationship between the transmittance and the methanol concentration, that is, the wettability of the toner, that is, the hydrophobic property of the toner is measured using a methanol dropping transmittance curve. Specifically, as the measuring device, for example, a powder wettability tester WET-100P manufactured by Reska Co., Ltd. may be mentioned, and specific measuring operations may include the methods exemplified below.

  First, 70 ml of a hydrated methanol solution composed of 40% by volume of methanol and 60% by volume of water is placed in a container and dispersed for 5 minutes with an ultrasonic disperser in order to remove bubbles and the like in the measurement sample. To this, 0.5 g of the toner as the specimen is precisely weighed and added to prepare a sample solution for measuring the hydrophobic property of the toner.

Next, while stirring the sample solution for measurement at a speed of 6.67 s ⁻¹ (rotational speed of the magnetic stirrer), methanol was added at 1.3 ml / min. Are continuously added at a dropping speed of, and the transmittance is measured with light having a wavelength of 780 nm to prepare a methanol dropping transmittance curve as shown in FIG. In this case, methanol was used as the titration solvent because various toner materials such as dyes, pigments and charge control agents contained in the toner particles are less likely to elute and the surface state of the toner can be observed more accurately. is there. In this measurement, the container is a cylindrical shape with a bottom diameter of 5 cm and a glass beaker with a thickness of 1.75 mm. The magnetic stirrer is a spindle shape with a length of 25 mm and a maximum diameter of 8 mm, and a fluororesin. What was coated with was used.

  When the toner gets wet at a methanol concentration of less than 40% by volume, the transmittance with light having a wavelength of 780 nm rapidly decreases and approaches 0% simply by adding the toner to the mixed solvent and stirring.

  The wettability of the toner is achieved by making the exposed state of the toner material on the surface of the toner particles uniform, and can be appropriately adjusted by controlling the dispersibility of each material in the toner. In particular, in the present invention, the wettability of the toner can be accurately controlled by considering a combination of a polyester resin, a wax, and a colorant.

  We have already mentioned that polyester resin is advantageous for improving edge offset by improving the affinity between toner and paper, or suppressing charge-up phenomenon, but especially for improving edge offset. It is preferable to combine a polyester resin with a non-polar wax having no polar group such as an acid group or a hydroxyl group, and it is particularly preferable to combine paraffin wax, polyolefin wax, and Fischer-Tropsch wax.

  Since these waxes with small polarity have a large difference in polarity with the polyester resin, the phase separation speed of the wax when the toner is melted by heat at the time of fixing is large, and the wax exudes instantly on the toner particle surface, This is preferable because it increases the adhesion of toner to paper.

  However, in order to uniformly disperse the wax having a large polarity difference from the polyester resin in the toner particles, it is necessary to select production conditions so that the wax does not melt and re-aggregate, and the toner kneading temperature is set to a low temperature, It is important to disperse the wax in the resin by applying a strong force and to keep the temperature of the kneaded product low.

  On the other hand, in order to uniformly disperse the components dispersed in the toner particles, such as a colorant such as a magnetic material, the kneading temperature is set to a high temperature and the resin is melted and softened. The conditions for kneading in such a state are preferred. In particular, when a binder resin containing a hard component such as a THF-insoluble component is used, it is easy to uniformly disperse a colorant such as a magnetic substance by softening and kneading the binder resin at a high temperature.

  As described above, it is easy to uniformly disperse the low-polarity wax in the polyester resin by low-temperature kneading, and it is easy to uniformly disperse the colorant such as the magnetic material by high-temperature kneading. Since they are different, it is very difficult to uniformly disperse wax and a colorant such as a magnetic substance in toner particles using a polyester resin, and it is necessary to combine them in consideration of the physical properties of the respective materials.

  In the case of using a magnetic material as a colorant, the present inventors have determined the solubility parameter (SP value) of the wax in order to disperse the non-polar or low polarity wax and the magnetic material in the polyester resin in a nearly uniform state. It was found that it is important to manage the isoelectric point obtained from the zeta potential of the magnetic material.

  Specifically, in order to disperse the nonpolar wax and the magnetic substance in the polyester resin in a nearly uniform state, a hydrocarbon wax having an SP value of 9 or less (preferably 7 to 9), and an isoelectric point of pH = It is preferable to use a combination of magnetic materials in the range of 5-9 (preferably 6-8). Since the polyester resin has many acidic groups in its molecular structure, the magnetic substance present in the polyester resin is placed in an acidic environment during kneading. A magnetic material having an isoelectric point in the above range has a positive zeta potential during kneading and serves to locally weaken the polarity of the polyester resin, so that the difference in polarity between the polyester resin and the wax is reduced. It works to greatly improve dispersibility.

  As a result, the kneading conditions can be set to be advantageous for the dispersion of the magnetic material, and the dispersion of the wax and the magnetic material can be made compatible at a high level. It is possible to obtain a toner that can be exposed in a close state, and has optimum wettability for suppressing edge offset, charge-up, and low density after standing. In addition, since the kneading temperature can be set to a high temperature that is advantageous for dispersing the magnetic substance, when the aromatic hydroxycarboxylic acid compound of aluminum is contained in the toner particles, the thermal cross-linking reaction due to kneading tends to proceed, making it suitable for the toner. It is also possible to have an appropriate amount of THF-insoluble matter.

  As one of the toner manufacturing methods, in the present invention, a mechanical pulverizer as shown in FIGS. 2, 3 and 4 can be used to pulverize and surface the powder raw material. Therefore, the efficiency is improved, which is preferable. In this pulverizer, the temperature during pulverization is adjusted, a polyester resin is used as a main component of the binder resin, a wax having an SP value of 9 or less, and a magnetic material having an isoelectric point of pH = 5 to 9 is used. By satisfying the THF insoluble content and the GPC chromatogram, the surface state of the toner can be controlled more precisely.

  Hereinafter, the mechanical pulverizer shown in FIGS. 2, 3 and 4 will be described. 2 shows a schematic cross-sectional view of an example of a mechanical pulverizer used in the present invention, FIG. 3 shows a schematic cross-sectional view taken along the line DD ′ in FIG. 2, and FIG. The perspective view of the rotor 314 shown in FIG. 2 is shown.

  As shown in FIG. 2, the mechanical pulverizer includes a casing 313, a jacket 316, a distributor 220, and a rotating body mounted on a central rotating shaft 312 in a casing 313, and a large number of surfaces are rotated at high speed. Rotor 314 provided with a plurality of grooves, stator 310 provided with a large number of grooves on the surface of the rotor 314 arranged at regular intervals on the outer periphery, and for introducing a raw material to be treated A raw material inlet 311 and a raw material outlet 302 for discharging the processed powder. The finely pulverized product is collected by a fine powder collecting device having a bag filter 222, a suction blower 224, and a collecting cyclone.

  Usually, when the pulverized raw material is pulverized by a mechanical pulverizer, the temperature T1 of the spiral chamber 212 and the temperature T2 of the rear chamber 320 of the mechanical pulverizer are controlled, and pulverization is performed at Tg or less of the binder resin. A method that does not perform surface modification is selected. However, in order to obtain the toner of the present invention, the temperature of the discharge port 302 is set to −25 to −5 ° C. from the Tg of the binder resin, and −20 to ± 0 ° C. from the Tg of the binder resin in the actual pulverized state. With this temperature, among those exposed on the surface of the toner particles, those that are exposed too much are pulverized so as to be driven into the toner particles by impact when they collide with the rotor or stator surface. As a result, the distribution of the raw material on the toner surface is likely to be uniform, and the hydrophobic characteristics characteristic of the present invention can be imparted to the toner.

  The toner of the present invention is required to have a MI at 125 ° C. and a load of 5 kg in the range of 0.1 to 10 g / 10 min (preferably 0.1 to 5 g / 10 min). The viscosity of the melt is suitable for uniformly dispersing the wax and magnetic material, and it is easy to control the surface state of the toner. In addition, it has excellent characteristics for edge offset and high temperature offset. Show. Further, since the surface treatment of the toner particles by the mechanical pulverizer is also effectively performed, it is easy to control the wettability of the toner.

  When the MI of the toner is less than 0.1 g / 10 min, the viscosity of the melt at the time of kneading is too high and the dispersion of the magnetic material is particularly likely to deteriorate, and it is difficult to uniformly disperse in the toner. Further, even if the pulverization conditions are set as described above, the toner particles are too hard to be easily subjected to the surface treatment of the toner, and the hydrophobic characteristics characteristic of the present invention may not be obtained. When the MI of the toner is larger than 10 g / 10 min, the viscosity of the melt at the time of kneading may be too high and the wax dispersion may be deteriorated, or the viscosity of the toner may be too low and the high temperature offset may be deteriorated. Furthermore, there is a tendency for high temperature offset to occur at the same time under conditions where edge offset occurs, so if it exceeds 10 g / 10 min, the problem of edge offset is improved even if the hydrophobic characteristics are satisfied. There are things you can't do.

  The toner of the present invention contains 5 to 40% by mass (preferably 10 to 30% by mass) of tetrahydrofuran (THF) insoluble matter based on the binder resin. Further, the toner of the present invention has a main peak in the molecular weight region of 3000 to 20,000 in a chromatogram obtained by measuring the THF soluble content of the toner by gel permeation chromatography (GPC), It is necessary to contain 50% by mass or more of a component having a molecular weight of 10,000 or less.

  The tetrahydrofuran (THF) insoluble matter is a resin component insoluble in THF among the components contained in the toner particles. Examples of toner materials that are insoluble in THF and do not fall under the resin component include waxes, charge control agents, colorants such as magnetic substances and pigments, and external additives such as inorganic fine powders. The content of these components in the toner is determined by calculating the content, measuring the ash content, and the like, and is distinguished from the THF-insoluble content in the present invention.

  The toner of the present invention contains 5 to 40% by mass of a THF-insoluble component and 50% by mass or more of a component having a molecular weight of 10,000 or less in the THF-soluble component. A low low molecular weight component is contained in a predetermined amount, the change in the melt viscosity of the toner with respect to temperature fluctuations during kneading is reduced, and a constant kneading share can be given to the kneaded product. Improves dispersibility and makes it easier to control the hydrophobic properties of the toner. As a result, end offset and charge-up problems can be improved. Further, since such a binder resin has a wide molecular weight distribution, it is possible to achieve both excellent fixing properties and high temperature offset properties.

  Furthermore, in the toner of the present invention, since the peak top molecular weight of the main peak is in the region of 3000 to 20,000, the mechanical strength of the toner can be increased and overpulverization is prevented. The surface treatment of the toner is appropriately performed, and a desired hydrophobic property of the toner can be obtained.

  When the THF-insoluble content of the toner is less than 5% by mass, the melt viscosity at the time of kneading becomes too low, the dispersion of the wax deteriorates, making it difficult to control the hydrophobicity of the toner, and the mechanical strength of the toner is reduced. The toner may easily deteriorate due to the load in the developing machine, and the developing durability may deteriorate. When the THF insoluble content of the toner is more than 40% by mass, the load at the time of kneading is large, the material dispersibility is deteriorated and desired hydrophobic properties cannot be obtained, the developability is deteriorated, or the fixing property is inhibited. Sometimes.

  When the peak top molecular weight is less than 3000, the mechanical strength of the toner is reduced, overpulverization is likely to occur, the wettability of the toner to the mixed solvent of methanol and water is difficult to control, and edge offset and charge-up are prevented. In addition, the development durability may be reduced. If the peak top molecular weight is greater than 20,000, the grindability will deteriorate and it will not be possible to obtain a toner with the desired particle size, or the heat generated during grinding will be too great and the surface treatment of the toner will not be performed properly. There is. In addition, the melt viscosity at the time of kneading is increased, so that the dispersion of the colorant may be deteriorated or the fixability may be deteriorated.

  Further, if the content of the component having a molecular weight of 10,000 or less contained in the THF-soluble component is less than 50% by mass, the melt viscosity of the kneaded product becomes high, the dispersion of the colorant deteriorates, and the hydrophobicity of the toner May be out of control.

  It should be noted that the content of the toner particles, the content of insoluble THF, the main peak area in GPC, and the proportion of components having a molecular weight of 10,000 or less in THF are the materials constituting the toner particles (for example, binder resin and charge control). And the like, depending on the type and blending amount of the agent and the production conditions of the toner.

  The toner of the present invention preferably has a weight-average molecular weight (Mw) of THF-soluble component of 200,000 or more (preferably 500,000) in order to increase the mechanical strength of the toner and improve the development durability.

  Further, the toner of the present invention has a weight average molecular weight (Mw) to number average molecular weight (Mn) ratio, Mw / Mn of 20 or more (preferably 50 or more) in a chromatogram obtained by measuring THF soluble content by GPC. More preferably, the ratio between the z-average molecular weight (Mz) and the weight-average molecular weight (Mw), and Mz / Mw is 30 or more (more preferably 50 or more), in order to obtain better fixing properties and high-temperature offset properties. preferable. The various average molecular weights are appropriately adjusted according to the adjustment of the degree of polymerization of the binder resin, the type and blending amount of the toner material used, and the like.

  The toner of the present invention contains a binder resin containing a polyester resin as a main component, but other resin components may contain known resins such as vinyl resins and hybrid resins. In the present invention, “comprising a polyester resin as a main component” means that 50% by mass or more of the binder resin is a polyester resin.

  The polyester resin used in the present invention has a low molecular weight polyester component having a main peak molecular weight of 3000 to 20,000 and a THF insoluble content of 0 to 3% by mass, and a THF insoluble content of 10 to 60. It is preferable that the ratio of the mass of the crosslinked polyester component and the low molecular weight polyester component is 10:90 to 90:10. The mass ratio is more preferably 30:70 to 70:30, and still more preferably 40:60 to 60:40.

  By mixing the low molecular weight polyester component and the cross-linked polyester component at such a ratio, it becomes possible to easily obtain a molecular weight distribution and a THF-insoluble content that are difficult to achieve with a single polyester component. Can be controlled more easily, and it becomes easier to balance the hydrophobic characteristics, the fixing property, the high temperature offset property, and the developing property. If the ratio of the low molecular weight polyester is higher than this, the dispersibility of the wax may be deteriorated and desired hydrophobic characteristics may not be obtained, and high temperature offset resistance and development durability may be deteriorated. May deteriorate, and dispersion of the colorant may deteriorate.

  Furthermore, it is preferable that the crosslinked polyester component contains a trivalent or higher polyvalent carboxylic acid and a trivalent or higher polyhydric alcohol as monomer components.

  Trivalent or higher polyvalent carboxylic acids and polyhydric alcohols are mainly used to give polyesters a cross-linking component. By using these trivalent or higher components as both the acid component and the alcohol component. It is easy to balance the acid value and the hydroxyl value, easily control the wettability of the toner, and easily improve the problems of edge offset and charge-up.

  Further, in the present invention, the trihydric or higher polyhydric alcohol is an oxyalkylene ether of a novolak type phenol resin, and the trihydric or higher polyhydric carboxylic acid is trimellitic acid, so that high temperature offset can be achieved without deteriorating the fixability. It is preferable for enhancing the properties. Use of oxyalkylene ether of novolak type phenolic resin produces a flexible cross-linked product that has a very high molecular weight and a long distance between the cross-linking points (the molecular weight between the cross-linking points becomes large) and is likely to undergo molecular motion due to heat. Is done. Such a cross-linking component easily incorporates a low molecular weight polyester component into the molecule and is likely to be softened by heat. Furthermore, since the molecular weight is very large, the viscosity is not lowered more than necessary. Therefore, it is more preferable for enhancing the high temperature offset property without impairing the fixing property.

  In addition, when trimellitic acid is used as a polyvalent carboxylic acid having a valence of 3 or more, when an aromatic hydroxycarboxylic acid compound of aluminum is contained, thermal crosslinking reaction easily occurs due to heat during kneading, and shearing during kneading This is preferable because it is possible to compensate for the THF-insoluble content of the toner that decreases.

  The polyester resin used in the present invention preferably has an acid value of 5 to 40 mgKOH / g and a hydroxyl value of 10 to 50 mgKOH / g. When the acid value is less than 5 mgKOH / g or the hydroxyl value is less than 10 mgKOH / g, the toner becomes difficult to wet with a mixed solvent of methanol and water, and the degree of hydrophobicity tends to increase. In some cases, the offset and charge-up may deteriorate. When the acid value is larger than 40 mgKOH / g or the hydroxyl value is larger than 50 mgKOH / g, the hydrophobicity of the toner is likely to be lowered, and the image density after being left in a high-temperature and high-humidity environment may be greatly decreased. There is sex. On the other hand, if the acid value is too high, even if the isoelectric point of the magnetic material is controlled, the function of weakening the polarity of the polyester resin is not sufficient, and the effect of improving wax dispersion becomes difficult to obtain.

  The crosslinked polyester component used in the present invention has an MI at 190 ° C. and 10 kg load of 0.1 to 10 g / 10 min (preferably 0.1 to 5 g / 10 min, more preferably 0.3 to 3 g / 10 min). Is preferable for satisfying the developability, fixability, high temperature offset and end offset at a high level.

  When MI of the crosslinked polyester component is less than 0.1 g / 10 min, the melt viscosity of the crosslinked polyester component is too high, and the viscosity difference from the low molecular weight polyester component becomes large. It becomes difficult to uniformly mix the low molecular weight polyester component. As a result, the ratio of the cross-linked polyester component to the low molecular weight polyester component for each toner particle and the dispersion state of raw materials such as wax and colorant are likely to be uneven, and the wettability variation for each toner particle with respect to the mixed solvent of methanol and water is varied. It becomes difficult to control the methanol concentration at 45% to 65% by volume when the transmittance is 80% and 10%. As a result, toner particles with non-uniform wettability are likely to be obtained, and charge-up and edge offset may be deteriorated or fixability may be deteriorated. When MI of the crosslinked polyester component is larger than 10 g / 10 min, the high temperature offset may be deteriorated, or the melt viscosity at the time of kneading may be too low to deteriorate the wax dispersion.

  The monomer component which comprises the polyester resin used for this invention is shown below. 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, , 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, bisphenol represented by the following formula (A) and derivatives thereof; and diol represented by the following formula (B) Kind.

  Examples of the divalent acid component include benzenedicarboxylic 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. 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; fumaric acid, maleic acid, citraconic acid, itaconic acid And unsaturated dicarboxylic acids such as, anhydrides thereof, and lower alkyl esters.

  In the present invention, as described above, it is preferable to use a trihydric or higher alcohol component and a trihydric or higher acid component that serve as a crosslinking component, but 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-butanetriol, 1,2,5-pentanetriol, glycerol, 2- Examples include methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxybenzene. Particularly preferred trihydric or higher polyhydric alcohol components include oxyalkylene ethers of novolac-type phenol resins.

  The oxyalkylene ether of the novolak type phenol resin has a structure in which a novolak type phenol resin and a compound having one epoxy ring in the molecule are ether-bonded.

  Examples of the novolac-type phenolic resin include hydrochloric acid, phosphoric acid, as described in the paragraph of “Encyclopedia of Polymer Science and Technology (Interscience Publishers), Vol. In addition, an inorganic acid such as sulfuric acid, an organic acid such as paratoluenesulfonic acid or oxalic acid, or a metal salt such as zinc acetate may be used as a catalyst to be produced by polycondensation from phenols and aldehydes.

  Examples of the phenols include substituted phenols having one or more phenols or hydrocarbon groups having 1 to 35 carbon atoms and / or halogen groups as substituents. Specific examples of the substituted phenol include cresol (ortho, meta or para), ethylphenol, nonylphenol, octylphenol, phenylphenol, styrenated phenol, isopropenylphenol, 3-chlorophenol, 3-bromophenol, 3, 5-xylenol, 2,4-xylenol, 2,6-xylenol, 3,5-dichlorophenol, 2,4-dichlorophenol, 3-chloro-5-methylphenol, dichloroxylenol, dibromoxylenol, 2 , 4,5-trichlorophenol, 6-phenyl-2-chlorophenol. Two or more phenols may be used in combination.

  In these, the substituted phenol substituted by the phenol and the hydrocarbon group is preferable, and especially phenol, cresol, t-butylphenol, and nonylphenol are preferable. Phenol and cresol are preferable in terms of imparting price and toner offset resistance, and substituted phenols substituted with hydrocarbon groups, such as t-butylphenol and nonylphenol, reduce the temperature dependence of the toner charge amount. Is preferable.

  Examples of the aldehydes include formalin (formaldehyde solutions having various concentrations), paraformaldehyde, trioxane, and hexamethylenetetramine.

  The number average nucleus number of phenols in the novolak type phenol resin is usually 3 to 60, preferably 3 to 20, and more preferably 4 to 15. Moreover, a softening point (JIS K7231; ring and ball method) is 40-180 degreeC normally, Preferably it is 40-150 degreeC, More preferably, it is 50-130 degreeC. If the softening point is less than 40 ° C., it will be blocked at room temperature and difficult to handle. On the other hand, if the softening point exceeds 180 ° C., gelation may be caused in the production process of the polyester resin, which is not preferable.

  Specific examples of the compound having one epoxy ring in the molecule include, for example, ethylene oxide (EO), 1,2-propylene oxide (PO), 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide. And epichlorohydrin. Moreover, the glycidyl ether of C1-C20 aliphatic monohydric alcohol or monohydric phenol can also be used. Of these, EO and / or PO are preferred.

  The number of moles of the compound having one epoxy ring in the molecule is usually 1 to 30 moles, preferably 2 to 15 moles, more preferably 2.5 to 10 moles per mole of novolak type phenol resin. The average addition mole number of the compound having one epoxy ring in the molecule per one phenolic hydroxyl group in the type phenol resin is usually 0.1 to 10 mol, preferably 0.1 to 4 mol, more preferably 0.2. ~ 2 moles.

  The structure of the oxyalkylene ether of the novolak type phenol resin particularly preferably used in the present invention is illustrated.

（Ｃ）
（式中、Ｒはエチレン基又はプロピレン基であり、ｘは０以上の整数であり、ｙ１〜ｙ３は０以上の同一又は異なった整数であり、ｘが２以上であるとき、それぞれのｙ２は同じ値でも良いし異なる値でも良い。）
ノボラック型フェノール樹脂のオキシアルキレンエーテルの数平均分子量は通常３００〜１００００、好ましくは３５０〜５０００、さらに好ましくは４５０〜３０００である。数平均分子量が３００未満ではトナーの耐オフセット性が不十分となることがあり、１００００を超えるとポリエステル樹脂の製造過程でゲル化を引き起こすことがあり好ましくない。

(C)
(In the formula, R is an ethylene group or a propylene group, x is an integer of 0 or more, y1 to y3 are 0 or more of the same or different integers, and when x is 2 or more, each y2 is (It can be the same value or different values.)
The number average molecular weight of the oxyalkylene ether of the novolak type phenol resin is usually 300 to 10000, preferably 350 to 5000, and more preferably 450 to 3000. If the number average molecular weight is less than 300, the offset resistance of the toner may be insufficient, and if it exceeds 10,000, gelation may be caused in the production process of the polyester resin.

  The hydroxyl value (total of alcoholic and phenolic hydroxyl groups) of the oxyalkylene ether of the novolak type phenol resin is usually 10 to 550 mgKOH / g, preferably 50 to 500 mgKOH / g, more preferably 100 to 450 mgKOH / g. Of the hydroxyl values, the phenolic hydroxyl value is usually 0 to 500 mgKOH / g, preferably 0 to 350 mgKOH / g, more preferably 5 to 250 mgKOH / g.

  Exemplifying a method for producing an oxyalkylene ether of a novolak-type phenol resin, a compound having one epoxy ring in a molecule is added to a novolak-type phenol resin in the presence of a catalyst (basic catalyst or acidic catalyst) as necessary. Is obtained. The reaction temperature is usually 20 to 250 ° C., preferably 70 to 200 ° C., and can be carried out under normal pressure or under pressure, and further under reduced pressure. The reaction can also be carried out in the presence of a solvent (for example, xylene, dimethylformamide, etc.) or other dihydric alcohols and / or other trihydric or higher alcohols.

  Examples of the trivalent or higher polyvalent carboxylic acid component as the monomer component constituting the polyester resin used in the present invention include pyromellitic acid, 1,2,4-benzenetricarboxylic acid, and 1,2,5-benzene. Tricarboxylic 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, empole trimer acid, and their anhydrides, lower alkyl esters; Polycarboxylic acids such as tetracarboxylic acids and their anhydrides, lower alkyl esters and derivatives thereof And the like. Of these, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, anhydrides thereof, and lower alkyl esters are preferable.

  About the component ratio in the polyester resin used for this invention, As an alcohol component, Preferably it is 40-60 mol%, More preferably, it is 45-55 mol%. Moreover, as an acid component, Preferably it is 60-40 mol%, More preferably, it is 55-45 mol%. Moreover, it is preferable that the polyvalent component more than trivalence is 5-60 mol% in all the components in total amount.

  The polyester resin is usually obtained by a generally known condensation polymerization. The polymerization reaction of the polyester resin is usually performed 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. 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, zinc acetate, lead acetate, cobalt acetate, sodium acetate, antimony trioxide, etc.). Polyester resin obtained 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 The physical properties of can be adjusted.

  Furthermore, the toner of the present invention contains a colorant, and various types of known colorants can be used depending on the type of toner.

  The toner of the present invention is preferably a magnetic toner, and the content of the magnetic material is 30 to 200 parts by mass (preferably 50 to 150 parts by mass) with respect to 100 parts by mass of the binder resin. Is preferred. In this case, the magnetic material can also serve as a colorant. By uniformly dispersing the magnetic material in the toner particles and appropriately exposing the magnetic material on the toner surface, it is possible to stabilize the charging of the toner, which is particularly effective for suppressing charge-up.

  Examples of the magnetic substance particularly preferably used in the present invention include those having an isoelectric point determined from the zeta potential in the range of pH = 5 to 9 (preferably 6 to 8). When the isoelectric point of the magnetic substance is within this range, the zeta potential of the magnetic substance in the acidic region shows a positive value. Therefore, when melt-mixed with a polyester resin having an acid value, the magnetic substance is mixed in the kneaded product. It is easy to have a positive potential. As a result, the polarity of the polyester resin present in the vicinity of the magnetic material is locally weakened, and even a wax having a large difference in polarity from the polyester resin can be easily dispersed, and the kneading conditions are advantageous for the dispersion of the magnetic material. Can be set to various conditions.

  When the isoelectric point is less than pH = 5, the zeta potential of the magnetic substance in the acidic region becomes small or negative, and the function of weakening the polarity of the polyester resin is reduced, and the wax dispersion is deteriorated. There is a case. When the isoelectric point is greater than pH = 9, the magnetic material has high hygroscopicity, and the hydrophobicity of the toner may be low, or the density decrease after leaving in a high humidity environment may be large.

The isoelectric point of the magnetic material can be obtained from the zeta potential. The zeta potential can be measured by, for example, DT-1200 (manufactured by Dispersion Technology). A magnetic substance is dispersed in a 0.01 mol / liter KNO ₃ solution at a concentration of 5% by mass, a graph of pH change of zeta potential is drawn, and an isoelectric point is calculated from the graph. The isoelectric point is the pH value when the zeta potential becomes zero.

  Examples of magnetic materials used in the present invention include iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel, or these metals and aluminum, cobalt, copper, lead, magnesium, manganese, selenium, titanium, Metal alloys such as tungsten and vanadium and mixtures thereof are used, and those containing a non-ferrous element on the surface or inside of the magnetic material are preferable.

  As the magnetic material used in the present invention, magnetic iron oxides such as magnetite, maghemite, and ferrite containing different elements and mixtures thereof are preferably used. Among them, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, titanium, zirconium, tin, lead, zinc, calcium, barium, scandium, vanadium, chromium, manganese, cobalt, copper, nickel, gallium, cadmium, indium It is preferably a magnetic iron oxide containing at least one element selected from silver, palladium, gold, mercury, platinum, tungsten, molybdenum, niobium, osmium, strontium, yttrium, technetium, ruthenium, rhodium, and bismuth. . In particular, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, zirconium, tin, and transition metal elements of the fourth period are preferable elements. These elements may be incorporated into the iron oxide crystal lattice, may be incorporated into the iron oxide as an oxide, or may exist on the surface as an oxide or hydroxide. The preferred form is contained as:

  In particular, it is preferable that one or more elements selected from the group consisting of magnesium, copper, zinc and titanium and silicon are present on the surface of magnetic iron oxide, and further, the outermost surface of such magnetic iron oxide An aluminum element is preferably present in order to control the zeta potential of the magnetic substance.

  The isoelectric point of magnetic iron oxide can be adjusted by the composition and surface state of the surface of magnetic iron oxide, such as production conditions such as pH, the amount of added metal element, and the degree of exposure of the added metal element to the surface of magnetic iron oxide.

  The magnetic iron oxide used in the present invention is a suitable salt containing a silicon element and a suitable salt containing any one or more elements selected from the four types of magnesium, copper, zinc and titanium. The magnetic iron oxide can be produced by appropriately adjusting the pH in the reaction system. Taking the case of using zinc as an element as an example, the method for producing magnetic iron oxide used in the present invention will be described below.

  In the magnetic iron oxide according to the present invention, after adding a predetermined amount of a metal salt of Zn and a silicate to an aqueous ferrous salt solution, an alkali such as sodium hydroxide or more equivalent to the iron component is added, and water is added. An aqueous solution containing ferrous oxide is prepared. Air was blown in while maintaining the pH of the prepared aqueous solution at pH 7 or higher (preferably pH 8 to 10), and iron oxide hydroxide was oxidized while heating the aqueous solution to 70 ° C. or higher. First, a seed crystal is formed.

  Next, an aqueous solution containing a first equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. Thereafter, the reaction of ferrous hydroxide proceeds while blowing air while maintaining the pH of the solution at 6 to 10, and magnetic iron oxide particles are grown with the seed crystal as a core. At this time, the progress of the oxidation reaction is advanced step by step in combination with the adjustment of the pH, for example, the pH is 9 to 10 in the early stage of the reaction, the pH is 8 to 9 in the middle of the reaction, and the late stage of the reaction. The composition ratio of the surface of the magnetic iron oxide can be controlled by allowing the oxidation reaction to proceed stepwise depending on the pH, such as at a pH of 6-8, and the isoelectric point of the magnetic iron oxide can be controlled. Cheap. Further, as the oxidation reaction proceeds, the pH of the liquid shifts to the acidic side, but the pH of the liquid is controlled not to be less than 6.

  Next, in order to make aluminum element exist on the outermost surface, when processing with aluminum hydroxide, water-soluble aluminum salt is formed in an alkaline suspension in which magnetic iron oxide particles containing silicon element are generated. After adding so that it may become 0.01-2.0 mass% in conversion of aluminum element with respect to particle | grains, pH is adjusted to the range of 6-8, and it precipitates as an aluminum hydroxide on the magnetic iron oxide surface. Subsequently, magnetic iron oxide having aluminum hydroxide is obtained by filtration, washing with water, drying and pulverization. Furthermore, as a method for adjusting the smoothness and the specific surface area to a preferable range, it is preferable to perform compression, shear and spatula using a mix muller or a raking machine.

  Examples of metal salts other than iron to be added include sulfates, nitrates, and chlorides. Examples of the silicate to be added include sodium silicate and potassium silicate.

  As ferrous salts, it is possible to use iron sulfate generally produced as a by-product in the production of sulfuric acid method titanium, iron sulfate produced as a by-product when the surface of the copper plate is cleaned, and iron chloride, etc. should also be used. Is possible.

  In a method for producing magnetic iron oxide by an aqueous solution method, generally, an iron salt is used at an iron concentration of about 0.5 to 2 mol / liter from the viewpoint of preventing an increase in viscosity during reaction and solubility of iron sulfate. . The iron sulfate concentration generally tends to be finer as the product becomes thinner. In the reaction, the larger the amount of air and the lower the reaction temperature, the easier the atomization.

  In some cases, the magnetic material used in the toner of the present invention may be treated with a silane coupling agent, a titanium coupling agent, or the like.

  As the colorant that can be used in the toner of the present invention other than the above-described magnetic substance, any appropriate pigment or dye can be used. Examples of the pigment include carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengara, phthalocyanine blue, and indanthrene blue.

  When a colorant other than a magnetic material is used, an amount necessary and sufficient to maintain the optical density of the fixed image is used, and 0.1 to 20 parts by weight, preferably 100 parts by weight of the binder resin. Is preferably added in an amount of 0.2 to 10 parts by mass. For the same purpose, a dye is further used. For example, there are azo dyes, anthraquinone dyes, xanthene dyes, methine dyes, etc., and the addition amount of 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight is good with respect to 100 parts by weight of the binder resin. .

  In the present invention, in order to further stabilize the chargeability of the toner, a metal compound as a charge control agent is added in an amount of 0.1 to 15 parts by mass (more preferably 0.1 to 10 parts by mass) with respect to 100 parts by mass of the binder resin. Part) It is preferable that the toner particles are blended (internal addition) or mixed with the toner particles (external addition). The charge control agent makes it possible to easily control the optimum charge amount according to the development system.

  For controlling the toner to be negatively charged, for example, organometallic compounds and chelate compounds are effective, and monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid based metal compounds. It is done. Other examples include aromatic hydroxycarboxylic acids, aromatic monocarboxylic acids, aromatic polycarboxylic acids, and metal salts thereof, anhydrides thereof, esters thereof, and phenol derivatives such as bisphenol.

  In the toner of the present invention, a positively chargeable charge control agent can be used as necessary. Examples of toners that can be controlled to be positively charged include modified products such as nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. And onium salts such as phosphonium salts thereof and their lake pigments, triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannin) Acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, Octyl tin borate, diorgano tin borate such as dicyclohexyl tin borate; guanidine compounds, and imidazole compounds. These can be used alone or in combination of two or more.

  Among these, triphenylmethane compounds and quaternary ammonium salts whose counter ions are not halogen are preferably used. Further, a homopolymer of a monomer represented by the following general formula (1) or a copolymer with a polymerizable monomer such as styrene, acrylic acid ester or methacrylic acid ester can be used as a positive charge control agent. These can constitute a binder resin (all or part).

  As the positively chargeable charge control agent, a compound represented by the following general formula (2) is particularly preferable in the configuration of the present invention.

  The above charge control agent is preferably used in the form of fine particles.

  In the present invention, a cross-linking reaction occurs with a polyvalent carboxylic acid in a polyester resin at the time of kneading, and an aromatic hydroxycarboxylic acid compound of aluminum capable of generating a THF-insoluble matter, and a stable chargeability in a long-term durability. Therefore, it is preferable to use in combination with a monoazo iron compound which is effective for charge-up and concentration reduction after standing in a high humidity environment. In this case, the aromatic hydroxycarboxylic acid compound of aluminum is preferably used in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin, and the monoazo iron compound is added to 100 parts by mass of the binder resin. On the other hand, it is preferable to use 0.1 to 10 parts by mass.

  Examples of hydroxycarboxylic acids (I) to (III) and azo compounds (IV) and (V) preferably used in the present invention are shown below.

  Furthermore, the example of the specific metal compound using the said hydroxy carboxylic acid or an azo compound is shown below.

  The toner of the present invention contains a wax. The wax used in the present invention has a peak end temperature of 70 to 120 ° C. (preferably 90 to 110 ° C.) at the endothermic peak at the time of temperature rise measured by DSC (differential scanning calorimeter). preferable.

  Examples of the wax used in the present invention include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxidized polyethylene wax. Oxides of aliphatic hydrocarbon waxes; or block copolymers thereof; plant waxes such as candelilla wax, carnauba wax, wood wax, jojoba wax; animal waxes such as beeswax, lanolin, whale wax; ozokerite Mineral waxes such as ceresin and petrolactam; waxes based on aliphatic esters such as montanic acid ester wax and castor wax; partially aliphatic esters such as deoxidized carnauba wax It includes those deoxidized all.

  Furthermore, 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, parinaric 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; ethylene Unsaturated fatty acid amides such as soleic acid amide, hexamethylene bis-oleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; 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 compound And the like.

  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 also preferable.

  Among them, the wax preferably used includes a wax having a solubility parameter (SP value) of 9 or less (preferably 7 to 9) and having no polar group. A wax having an SP value of 9 or less has a very large difference in polarity from the polyester resin, and is easy to phase-separate. Therefore, when the toner melts due to heat during fixing, the wax quickly exudes to the edge offset. Effective for deterrence and improvement of fixability. If the SP value is greater than 9, the difference in polarity from the resin becomes small, and the wax is difficult to phase separate, and the end offset and fixability may not be improved, or the high temperature offset may deteriorate. Further, if the SP value is less than 7, even if the isoelectric point of the magnetic material is controlled, the dispersibility of the wax tends to decrease.

  Examples of the wax preferably used include polyolefin waxes such as low molecular weight polyethylene and low molecular weight polypropylene, paraffin wax and Fischer-Tropsch wax, and particularly preferably low-molecular weight polyethylene wax and Fischer-Tropsch wax.

  The solubility parameter (SP) value of the wax is determined by the method of Fedors using the additivity of atomic groups [Polym. Eng. Sci. , 14 (2) 147 (1974)].

  These waxes are preferably contained in an amount of 1 to 10 parts by mass with respect to 100 parts by mass of the binder resin. In particular, the wax is charged into the reaction vessel together with the monomer during polymerization of the polyester resin, or after the resin polymerization is completed and before removal. It is preferable to add and stir in a state where the temperature is applied to the reaction tank and disperse the resin in the resin in order to uniformly disperse the wax in the binder resin.

  The toner of the present invention preferably has a Carr jet index greater than 80 and a Carr fluid index greater than 60.

  If the toner has a good jet property such that the jet property index is greater than 80, toner adhesion or white spots due to the application of extreme force to a part of the stirring member does not occur. For example, the toner can be stably stirred from the beginning of use of the cartridge until the toner runs out, and good developability can be provided. Furthermore, even if it is stored in a high temperature and high humidity environment, it is difficult to aggregate, and a good image can be obtained even if an image is output with a printer.

  When the fluidity index is larger than 60, the toner supply amount can be made constant even during long-term durability in a high-temperature and high-humidity environment, and stable image characteristics in which a decrease in image density is suppressed can be obtained.

  Further, by increasing the jetability index and the fluidity index from the above values, the toner fluidity is improved and the toner is easily clogged. As a result, since the thermal conductivity between the toners during fixing is improved, better fixability can be obtained.

  When the jetability index is 80 or less, high fluidity is obtained, but once clogged, it is difficult to flow even if force is applied. As a result, for example, in the cartridge, the toner is difficult to be conveyed to the sleeve, and the toner is charged in a state where the toner is non-uniformly placed on the sleeve. Therefore, the toner is also non-uniformly charged and the image tends to be uneven.

  Further, when the jetability index is 80 or less and the fluidity index is 60 or less, the toners tend to aggregate and do not flow easily. For example, the toner is transported from the toner storage portion in the cartridge to the adjacent storage portion. Hateful. For this reason, the toner is not transported, causing whiteout of the image, the proper amount of toner does not exist on the sleeve, and the amount of toner loaded on the sleeve is reduced, resulting in the occurrence of sleeve ghost, The toner tribo carried on the sleeve becomes too high and fog tends to occur.

  The jetability index and the fluidity index can be adjusted by sufficiently adjusting the type and amount of the external additive such as a fluidity improver. This is because, by examining the external additive formulation of the toner, the presence state of each external additive is changed, so that the powder characteristics of the toner are changed and the jetability index can be changed.

  The fluidity improver is one that can be added to the toner particles to increase the fluidity before and after the addition, and is usually charged with the same polarity as the toner. 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. Alumina, fine powdered alumina, silica treated with silane compound, titanium coupling agent, silicone oil; oxides such as zinc oxide and tin oxide; strontium titanate, barium titanate, calcium titanate, zirconic acid Examples thereof include double oxides such as strontium 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 average primary particle diameter is preferably in the range of 0.001 to 2 μm, and it is particularly preferable to use silica fine powder in the range of 0.002 to 0.2 μm.

  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 (CABOTCo. M-5, MS-7, MS-75, HS-5, EH-5, WackerHDKN20 (WACKER-CHEMIGMMBH) V15, N20E, T30, T40, D-CFineSilica (Dow Corning Co.), Francol ( There are those marketed under trade names such as (Fransil), and these can also be suitably used in the present invention.

  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, bromomethyldimethylchlorosilane, α- Chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyl Disiloxane, 1,3-divinyltetramethyldisiloxane, 1 Silane couplings such as 1,3-diphenyltetramethyldisiloxane and dimethylpolysiloxanes having 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one Si at each terminal unit Agents. Further examples include silicone oils such as dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil. These may be used alone or as a mixture of two or more. Moreover, a silicone varnish can also be used as a processing agent, for example, Shin-Etsu Silicone KR-251, KP-112, etc. can be used.

  Further, the silica fine powder is preferably treated by combining both a silane coupling agent and silicone oil or silicone varnish. As a preferable treatment form, first, treatment with a silane coupling agent and then treatment with silicone oil or silicone varnish can be mentioned. Among these, the form of treating with hexamethyldisilazane and then treating with dimethyl silicone oil is preferable.

The fluidity improver has a specific surface area by nitrogen adsorption of preferably not less than ^{30 m} 2 / g as measured by BET method, and more preferably ^{50 m} 2 / g or more, more preferably better those 70~150m ² / g Give a good result. The fluidity improver is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 4 parts by weight, and more preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the toner particles.

  As a specific configuration for achieving the above jet property and fluidity, for example, hydrophobic silica fine powder (charged to the same polarity as the toner) as a fluidity improver as described above and fine particles charged to the same polarity as the toner are used. Examples include a configuration used with an aggregate, a configuration in which resin fine particles having a polarity opposite to that of the toner are added as a third external additive, and a configuration in which a metal oxide is added as a fourth external additive.

  The fine particle aggregate used in the present invention comprises fine particles and silicone oil or silicone varnish, and the silicone oil or silicone varnish is present in a large amount of 20 to 90% by mass in total with respect to the total fine particle aggregate.

  As the fine particles, one or both of inorganic fine particles and organic fine particles are used. Examples of the organic compound include resin particle aliphatic compounds such as styrene resin, acrylic resin, silicone resin, silicone rubber, polyester resin, urethane resin, polyamide resin, polyethylene resin, and fluorine resin.

Examples of the inorganic compound include oxides such as SiO ₂ , GeO ₂ , TiO ₂ , SnO ₂ , Al ₂ O ₃ , B ₂ O ₃ , P ₂ O ₅ , As ₂ O ₃ ; silicates and boric acid Metal oxide salts such as salts, phosphates, germanates, borosilicates, aluminosilicates, aluminoborates, aluminoborosilicates, tungstates, molybdates, tellurates and the like, and complex compounds thereof Silicon carbide, silicon nitride, amorphous carbon; and the like. These may be used alone or in combination. As said inorganic compound, the inorganic compound fine powder manufactured by the dry method and the wet method can be used.

  As the silicone oil and the silicone varnish contained in the fine particle aggregate, the general ones as described above can be used.

  As described above, the fine particle aggregate contains a relatively large amount of a material having good releasability, such as silicone oil or silicone varnish, of 20% by mass to 90% by mass. Works to improve releasability from the body surface. When the amount of silicone oil or silicone varnish is less than 20% by mass, environmental stability tends to be poor, while when it exceeds 90% by mass, it becomes difficult to hold the silicone oil or silicone varnish in fine particles, and excessive silicone oil or silicone The varnish aggregates the toner particles, and the image quality is liable to deteriorate. The amount of silicone oil or silicone varnish in the fine particle aggregate is preferably 27 to 85% by mass, more preferably 40 to 80% by mass.

  Of the silicone oil or silicone varnish, silicone oil is preferable because it is more easily applied to the surface of the electrostatic latent image carrier than the silicone varnish. In addition, it is preferable that the silicone oil does not contain an alkoxy group in terms of the effect of voiding.

  Further, the silicone oil or silicone varnish is formed into particles together with fine particles and stably held as particles, and the toner is not aggregated by the silicone oil or silicone varnish during storage of the toner. This greatly contributes to obtaining a good quality image.

  In addition, since the fine particle aggregate contains a large amount of the same compound as the hydrophobizing agent used in the hydrophobic silica, the charging property becomes the same polarity as the hydrophobic silica, and as described above, the hydrophobic property It repels silica and contributes to the uniform dispersion of hydrophobic silica on the toner particle surface.

The BET specific surface area of the fine particle aggregate is preferably 0.01 to 50 m ² / g (more preferably 0.05 to 30 m ² / g). When the BET specific surface area of the fine particle aggregate is less than 0.01 m ² / g, the image quality tends to deteriorate. When the BET specific surface area is larger than 50 m ² / g, the silicone oil or the silicone varnish is difficult to hold as particles, and the toner aggregates. Cause deterioration of image quality.

  The addition amount of the fine particle aggregate is preferably 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the toner particles. When the addition amount of the fine particle aggregate is less than 0.01 parts by mass, the dispersion of the hydrophobic silica fine powder is deteriorated, and when it is more than 3.0 parts by mass, charge-up is likely to occur.

  The resin fine particles used in the present invention are fine particles composed of a resin that is charged with a polarity opposite to that of the toner. The resin fine particle is not particularly limited as long as it is a resin that is charged with a polarity opposite to that of the toner. However, since the toner of the present invention uses a polyester resin as a binder resin, it is usually negatively charged. Due to its excellent charging characteristics, a melamine resin is usually used as the resin of the resin fine particles. Preferred examples of such melamine resins include those produced by condensation of melamine and formaldehyde, etherified with an aliphatic alcohol, or those obtained by modifying this melamine resin with paratoluenesulfonamide or the like. However, the present invention is not limited to this.

The BET specific surface area of the resin fine particles is preferably 5.0 to 70 m ² / g (more preferably 10 to 40 m ² / g). When the BET specific surface area of the resin fine particles is smaller than 5.0 m ² / g, the amount of adsorbing free fine particle aggregates is not preferable. When it is larger than 70 m ² / g, it becomes difficult to sufficiently reduce the abrasion of the electrostatic latent image carrier due to the metal oxide.

  The addition amount of the resin fine particles is preferably 0.005 to 0.5 parts by mass with respect to 100 parts by mass of the toner particles. If the amount of resin fine particles added is less than 0.005 parts by mass, the polishing ability of the metal oxide cannot be relaxed in a well-balanced manner. There is.

  Various metal oxides can be used for the metal oxide used in the present invention. The metal oxide is preferably one that is charged with a polarity opposite to that of the toner. Examples of the metal oxide include magnesium, zinc, aluminum, cobalt, zirconium, manganese, cerium, strontium and the like, and complex metal oxides such as calcium titanate, magnesium titanate, strontium titanate, and barium titanate. Is mentioned. Of these, strontium titanate and cerium oxide are most preferred from the standpoint of polishing on the latent electrostatic image bearing member and chargeability of the toner.

BET specific surface area of metal oxide is preferably 0.5~10.0m ² / g (more preferably 1 to 10 m ² / g) is. If the BET specific surface area of the metal oxide is less than 0.5 m ² / g, the surface of the electrostatic latent image carrier and the developer carrier (sleeve) are significantly scraped, which is not preferable. If it is greater than 10.0 m ² / g, the deposit on the surface of the electrostatic latent image carrier may not be removed, or the cleaning member may pass through and lead to image defects.

  The addition amount of the metal oxide is preferably 0.05 to 5.0 parts by mass (more preferably 0.05 to 2.0 parts by mass) with respect to 100 parts by mass of the toner particles. If the addition amount of the metal oxide is less than 0.05 parts by mass, the polishing force to the electrostatic latent image carrier tends to be insufficient, and if it is more than 5.0 parts by mass, the electrostatic latent image carrier However, the toner may be scraped more than necessary and non-uniformly, and toner fluidity may be further reduced.

  In addition, in the present invention, when all of the four types of external additives described above are added, the four types of external additives are uniformly present on the surface of the individual toner particles due to the electrical balance. Even in a high-speed development system, it is more preferable for preventing the occurrence of problems such as tailing.

The effects of the types and combinations of external additives used in the present invention are summarized below.
Hydrophobic silica improves fluidity and exhibits stable development performance without absorbing moisture even in high humidity environments. Further, the impurities adhering to the drum are scraped off to prevent the impurities from adhering to the drum surface again.
-By adding fine particle aggregates of the same polarity to hydrophobic silica, an electrical repulsive force is generated between external additives, suppressing the aggregation of hydrophobic silica, and uniformly dispersing hydrophobic silica on the toner surface There is. Furthermore, it has the effect of scraping out fine impurities on the drum.
・ By adding a positively charged metal oxide to the negative polarity particles, the chargeability is stabilized, and impurities such as strongly sticking on the drum are scraped off. Providing stable images without wearing.
Further, by adding positively charged resin fine particles to these, the chargeability is further stabilized, and a high-quality image without tailing can be provided even in a high-speed development system.

  The measurement of the fluidity index and the jetability index described in this article is described in detail in Japanese Patent Publication No. 51-14278, and is not particularly limited, but in the present invention, it is measured by the following method.

  That is, using a powder tester P-100 (manufactured by Hosokawa Micron Corporation), parameters of repose angle, collapse angle, difference angle, degree of compression, degree of aggregation, spatula angle, and degree of dispersion are measured. The values obtained for each were applied to the following Carr's fluidity index table and jetability index table (Chemical Engineering. Jan. 18.1965), converted to each index of 25 or less, and the index determined from each parameter. Is calculated as the fluidity index / jetability index.

  An example of a method for measuring each parameter is shown below.

(1) Angle of repose 150 g of toner is passed through a mesh having a mesh size of 710 μm, and the toner is deposited on a circular table having a diameter of 8 cm. At this time, the toner is deposited so that the toner overflows from the end of the table. At this time, an angle formed between the ridge line of the toner deposited on the table and the circular table surface is measured with a laser beam. This is the angle of repose.

(2) Compressibility From the loosely packed bulk density (relaxed apparent specific gravity, “A”) and the tapping bulk density (hardened apparent specific gravity, “P”), the compressibility can be obtained by the following equation.
Compressibility (%) = 100 (PA) / P
The loose apparent specific gravity is, for example, that 150 g of toner is gently poured into a cup having a diameter of 5 cm, a height of 5.2 cm, and a capacity of 100 ml, and when the toner is filled in a measuring cup, the toner surface is ground and the cup is filled. It is obtained by calculating the specific gravity of the toner filled in the cup from the amount of toner and the capacity of the cup.

  For the apparent apparent specific gravity, for example, add the attached cap to the measuring cup used for the loose apparent specific gravity, fill the cup with toner, tap the cup 180 times, remove the cap when tapping is completed, and pile up the cup. The excess toner is removed, and the specific gravity of the toner filled in the cup is calculated from the amount of toner filled in the cup and the capacity of the cup. Both apparent specific gravity values are inserted into the above formula to determine the degree of compression.

(3) Spatula angle A 3 cm × 8 cm spatula is placed in contact with the bottom of a 10 cm × 15 cm bat, and toner is deposited on the spatula. At this time, the toner is deposited so as to rise on the spatula. Thereafter, only the bat is gently lowered, and the inclination angle of the toner side surface remaining on the spatula is measured with a laser beam. Then, after applying an impact once with a shocker attached to the spatula, the spatula angle is measured again. The average of this measured value and the measured value before giving an impact is defined as a spatula angle.

(4) Aggregation degree A sieve is set on the vibration table in the order of openings of 250 μm, 150 μm, and 75 μm from the top. The vibration amplitude is 1 mm, the vibration time is 20 seconds, and 5 g of toner is gently put on it to vibrate. After the vibration stops, measure the weight remaining on each sieve. The weight of the toner remaining on each sieve is applied to the following formula, and each value of a, b, and c is obtained from each formula. The sum of a, b, and c is defined as the degree of aggregation (%).
a = (amount of toner remaining on upper screen) ÷ 5 (g) × 100
b = (amount of toner remaining on the middle screen) ÷ 5 (g) × 100 × 0.6
c = (amount of toner remaining on the lower screen) ÷ 5 (g) × 100 × 0.2
(5) Collapse angle After the angle of repose is measured, impact is applied three times with a shocker to the bat on which the circular table for measurement is placed. Thereafter, the angle of the toner remaining on the table is measured using a laser beam. This is the collapse angle.

(6) Difference angle Find the difference between the angle of repose and the collapse angle. This is the difference angle.

(7) Dispersion 10 g of toner is dropped as a lump onto a watch glass having a diameter of 10 cm from a height of about 60 cm. Then, the toner remaining on the watch glass is measured, and the degree of dispersion is obtained by the following equation.
Dispersity (%) = [10− (amount of toner remaining on the plate)] × 10
The sum of the indices ((1) + (2) + (3) + (4)) in the parameters (1), (2), (3), and (4) is the Carr's fluidity index. Further, the sum of the Carr's fluidity index and the indices of the parameters (5), (6), and (7) is the Carr's jetability index.

  The toner of the present invention can be used as a one-component developer, or can be mixed with a carrier and used as a two-component developer. As the carrier for use in the two-component developer, all conventionally known carriers can be used. Specifically, surface oxidized or unoxidized iron, nickel, cobalt, manganese, chromium, rare earth, etc. Particles having a volume 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 toner of the present invention is not particularly limited as long as it has the above-described physical properties and the like, and various known manufacturing methods can be adopted. An example of the method for producing the toner of the present invention is shown below.

  As a method for producing the toner of the present invention, a mixture containing at least a binder resin mainly composed of a polyester resin, a wax, and a colorant is used as a material. These additives are used. These materials were sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melted, kneaded and kneaded using a heat kneader such as a roll, a kneader and an extruder to make the resins compatible with each other. A toner can be obtained by dispersing wax or a magnetic substance therein, cooling and solidifying, and then performing pulverization and classification. The toner manufacturing method of the present invention can use the following known manufacturing apparatus depending on the situation.

  As a toner production apparatus, for example, as a mixer, a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); a super mixer (manufactured by Kawata Corporation); a ribocorn (manufactured by Okawara Seisakusho Co., Ltd.); a nauter mixer, a turbulizer, and a cyclomix (Hosokawa Micron Corporation) Spiral pin mixer (manufactured by Taiheiyo Kiko Co., Ltd.); Ladige mixer (manufactured by Matsubo Co., Ltd.), and KRC kneader (manufactured by Kurimoto Iron Works Co.); Bus co-kneader (manufactured by Buss) ); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.); triple roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho Co., Ltd.) ); Needex (Mitsui Mining Co., Ltd.); MS pressure kneader, Nider Ruder (Moriyama Seisakusho); Banbury Miki Chromatography (manufactured by Kobe Steel, Ltd.) and the like.

  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.);

  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 Kogyo Co., Ltd.); and YM micro cut (manufactured by Yaskawa Shoji Co., Ltd.).

  As a sieving device used for sieving coarse particles, Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokuju Kogakusha Co., Ltd.); Vibrasonic System (Dalton Co., Ltd.); Soniclean (Shinto) (Industry company); Turbo screener (Turbo industry company); Micro shifter (Ogino industry company); Circular vibration sieve, etc.

  The toner of the present invention can be used for image formation using a known image forming apparatus having an appropriate configuration according to the type thereof. In addition, when the toner of the present invention is used for image formation, a plurality of components such as a developing device having the above-described toner, an image carrier (photosensitive drum, etc.), a charging member, and a cleaning member are used as an apparatus unit. It is also a preferred form that a process cartridge is configured by being integrally connected, and the process cartridge is detachably mounted on the apparatus main body. For example, a process cartridge is formed by integrally supporting a charging member and a developing device together with a photosensitive drum to form a single unit that can be attached to and detached from the apparatus main body, and is detachably mounted using guide means such as a rail of the apparatus main body. Can be configured.

  The measurement of various physical properties relating to the toner of the present invention will be described below. In the present invention, the MI of the toner and the crosslinked polyester component, the molecular weight distribution of the THF soluble content of the toner and the binder resin, the content of the THF insoluble matter, Tg (glass transition temperature), the acid value of the binder resin, and the hydroxyl value are It can be measured by the following method.

(1) MI Measurement Method for Toner and Crosslinked Polyester Component Melt index (MI) is as follows using an apparatus having a configuration as described in JIS K 7210 (Melt Indexer Load Transfer Device; Takara Kogyo Co., Ltd.). The measurement is performed by the manual cutting method under the measurement conditions. At this time, the measured value is converted into a 10-minute value.
Measurement temperature: 125 ° C. (toner), 190 ° C. (crosslinked polyester component)
Load: 5 kg (toner), 10 kg (crosslinked polyester component)
Sample filling amount: 5-10 g
(2) Measurement of molecular weight of THF soluble matter of toner The molecular weight of the chromatogram by gel permeation chromatography (GPC) is measured under the following conditions.

The column is stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min. As a column, in order to accurately measure a molecular weight region of 10 ^{3 to} 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, shodex GPC KF-801, 802, 803 manufactured by Showa Denko KK , combination or 804,805,806,807,800P, Tosoh Corp. of _{TSKgel G1000H (H XL), G2000H} (H XL), G3000H (H XL), G4000H (H XL), G5000H (H XL), G6000H The combination of (H _XL ), G7000H (H _XL ), and TSKgourd column can be mentioned, and in particular, the combination of seven columns of shodex KF-801, 802, 803, 804, 805, 806, 807 manufactured by Showa Denko KK preferable.

  On the other hand, after the toner is dispersed and dissolved in THF and allowed to stand overnight, a sample processing filter (pore size 0.2 to 0.5 μm, for example, Mysori Disk H-25-2 (manufactured by Tosoh Corp.)) can be used. And the filtrate is used as a sample. Measurement is performed by injecting 50 to 200 μl of a THF solution of the toner adjusted so that the resin component is 0.5 to 5 mg / ml as a sample concentration. An RI (refractive index) detector is used as the detector.

In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Or the molecular weight of Toyo Soda Industry Co., Ltd. is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3 It is suitable to use a standard polystyrene sample of at least about 10 points using 9.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ .

(3) THF-insoluble content A polyester resin or 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. Extraction is performed for 16 hours using 200 ml of THF as a solvent. At this time, extraction is performed at a reflux rate such that the extraction cycle of THF is about once every 4 to 5 minutes. After completion of the extraction, the cylindrical filter paper is taken out and weighed to obtain an insoluble content of the polyester resin or toner.

When the toner contains a THF-insoluble component other than a resin component such as a magnetic substance or a pigment, the mass of the toner placed in the cylindrical filter paper is W ₁ g, and the mass of the extracted THF-soluble resin component is W _2. When the weight of the THF-insoluble component other than the resin component contained in the toner is W ₃ g, the amount of THF-insoluble content of the resin component in the toner can be obtained from the following formula.
THF insoluble content (mass%) = [W ₁ − (W ₃ + W ₂ )] / (W ₁ −W ₃ ) × 100
(4) Measurement of glass transition temperature (Tg) Tg of toner and binder resin is a differential scanning calorimeter (DSC measuring device), DSC-7 (manufactured by PerkinElmer), DSC2920 (manufactured by TA Instruments Japan). Using other models, measurement is performed according to ASTM D3418-82.

  The measurement trial accurately weighs 5 to 20 mg, preferably 10 mg. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min at room temperature and normal humidity within a measurement temperature range of 30 to 200 ° C. In this temperature rising process, a specific heat change is obtained in the temperature range of 40 to 100 ° C. At this time, the intersection of the intermediate line between the base line before and after the change in specific heat and the differential heat curve is defined as the glass transition temperature (Tg) of the toner and binder resin in the present invention.

(5) Measurement of acid value The acid value is determined by the following operations 1) to 5). Basic operations belong to JIS K 0070.
1) The sample is used after removing additives other than the binder resin (polymer component) in advance, or the acid value of the component other than the binder resin of the sample is obtained. Weigh accurately 0.5 to 2.0 g of the pulverized toner or binder resin. The binder resin component at this time is Wg.
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
(6) Measurement of hydroxyl value It is determined by the following operations 1) to 8). Basic operation conforms to JIS K 0070.
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 hydroxyl value according to the following formula.
A = [{(BC) × 28.05 × f} / S] + D
(However, A is a hydroxyl value (mgKOH / g), B is an 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)).

〔Example〕
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples.

[Binder resin production example]
(Polyester resin production example 1)
-25 parts by mass of terephthalic acid-3 parts by mass of trimellitic anhydride-Bisphenol derivative represented by formula (A) (R: propylene group, average value of x + y = 2.2) 72 parts by mass Dibutyltin oxide 0 as a catalyst .5 parts by mass, condensation polymerization at 220 ° C., low-molecular weight polyester resin L-1 not containing THF-insoluble matter (Tg: 56 ° C., THF-insoluble matter: 0% by mass, Mn: 4000, Mw: 7600 , Peak molecular weight: 9100, acid value: 11 mgKOH / g, hydroxyl value: 34 mgKOH / g).

(Polyester resin production example 2)
-18 parts by mass of terephthalic acid-3 parts by mass of isophthalic acid-7 parts by mass of trimellitic anhydride-Bisphenol derivative represented by the formula (A) (R: propylene group, x + y average value = 2.2) 70 parts by mass Oxyalkylene ether of novolak type phenol resin represented by formula (C) (R = ethylene group, average value of x = 2.6, average value of y1 to y3 = 1.0) 2 parts by mass Dibutyltin as a catalyst 0.5 parts by mass of oxide was added, and condensation polymerization was performed at 240 ° C. to form a crosslinked polyester resin H-1 (Tg: 56 ° C., THF-insoluble matter: 37% by mass, MI (190 ° C.): 1.1, Mn: 5300, Mw: 110,000, peak molecular weight: 8600, acid value: 24 mgKOH / g, hydroxyl value: 21 mgKOH / g).

(Polyester resin production example 3)
-15 parts by mass of terephthalic acid-4 parts by mass of isophthalic acid-9 parts by mass of trimellitic anhydride-Bisphenol derivative represented by formula (A) (R: propylene group, x + y average value = 2.2) 70 parts by mass Oxyalkylene ether of novolak type phenol resin represented by formula (C) (R = ethylene group, average value of x = 2.6, average value of y1 to y3 = 1.0) 2 parts by mass Dibutyltin as a catalyst 0.5 parts by mass of oxide was added, and condensation polymerization was performed at 240 ° C. to form a crosslinked polyester resin H-2 (Tg: 58 ° C., THF-insoluble matter: 49% by mass, MI (190 ° C.): 0.2, Mn: 5400, Mw: 130,000, peak molecular weight: 9000, acid value: 16 mgKOH / g, hydroxyl value: 15 mgKOH / g).

(Polyester resin production example 4)
-21 parts by mass of terephthalic acid-5 parts by mass of isophthalic acid-3 parts by mass of trimellitic anhydride-Bisphenol derivative represented by formula (A) (R: propylene group, average value of x + y = 2.2) 70 parts by mass Oxyalkylene ether of novolak type phenol resin represented by formula (C) (R = ethylene group, average value of x = 2.6, average value of y1 to y3 = 1.0) 1 part by mass Dibutyltin as a catalyst 0.5 parts by mass of oxide was added, and condensation polymerization was performed at 240 ° C. to form a crosslinked polyester resin H-3 (Tg: 55 ° C., THF-insoluble content: 22% by mass, MI (190 ° C.): 6.3, Mn: 5100, Mw: 100,000, peak molecular weight: 8200, acid value: 35 mgKOH / g, hydroxyl value: 26 mgKOH / g).

(Polyester resin production example 5)
-18 parts by mass of terephthalic acid-5 parts by mass of isophthalic acid-5 parts by mass of trimellitic anhydride-Bisphenol derivative represented by formula (A) (R: propylene group, average value of x + y = 2.2) 70 parts by mass Oxyalkylene ether of novolak type phenol resin represented by formula (C) (R = ethylene group, average value of x = 2.6, average value of y1 to y3 = 1.0) 2 parts by mass Dibutyltin as a catalyst 0.5 parts by mass of oxide was added, and condensation polymerization was performed at 240 ° C. to form a crosslinked polyester resin H-4 (Tg: 57 ° C., THF-insoluble content: 13% by mass, MI (190 ° C.): 11.1, Mn: 4800, Mw: 70,000, peak molecular weight: 7900, acid value: 15 mgKOH / g, hydroxyl value: 40 mgKOH / g).

(Polyester resin production example 6)
-18 parts by mass of terephthalic acid-3 parts by mass of isophthalic acid-7 parts by mass of trimellitic anhydride-Bisphenol derivative represented by formula (A) (R: propylene group, x + y average value = 2.2) 72 parts by mass 0.5 parts by mass of dibutyltin oxide as a catalyst was added to the polymer, and condensation polymerization was carried out at 240 ° C. to obtain a crosslinked polyester resin H-5 (Tg: 59 ° C., THF-insoluble matter: 15% by mass, MI (190 ° C.): 11. 8, Mn: 4700, Mw: 70,000, peak molecular weight: 7800, acid value: 37 mgKOH / g, hydroxyl value: 18 mgKOH / g).

(Polyester resin production example 7)
-11 parts by mass of terephthalic acid-5 parts by mass of isophthalic acid-10 parts by mass of trimellitic anhydride-Bisphenol derivative represented by formula (A) (R: propylene group, x + y average value = 2.2) 74 parts by mass 0.5 parts by mass of dibutyltin oxide as a catalyst was added to the polymer, and subjected to condensation polymerization at 240 ° C., to obtain a crosslinked polyester resin H-6 (Tg: 54 ° C., THF-insoluble content: 12% by mass, MI (190 ° C.): 18. 3, Mn: 4200, Mw: 60,000, peak molecular weight: 23100, acid value: 33 mgKOH / g, hydroxyl value: 35 mgKOH / g).

[Production of binder resins 1 to 5 and 7]
Low molecular weight polyester resin and cross-linked polyester resin are weighed at the ratios shown in Table 3, premixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.), and discharged with KRC kneader S1 (Kurimoto Iron Works Co., Ltd.) Melt blending was performed under conditions such that the temperature was 150 ° C. to obtain a binder resin. Table 3 shows the acid value and hydroxyl value of the obtained binder resin. For the binder resin 6, since the cross-linked polyester resin H-6 was used as the binder resin without being blended with the low molecular weight polyester resin, the melt blending was not performed, so the acid of the cross-linked polyester resin H-6 was not used. Value and hydroxyl value.

<Production Example 1 of Magnetic Iron Oxide>
After adding sodium silicate so that the content of silicon element is 0.60% by mass in the ferrous sulfate aqueous solution, the caustic soda solution is mixed, and the aqueous solution containing ferrous hydroxide is added. Prepared. Air was blown in while adjusting the pH of the aqueous solution to 10, and an oxidation reaction was performed at 80 to 90 ° C. to prepare a slurry liquid for generating seed crystals.

  When the formation of seed crystals was confirmed, an aqueous ferrous sulfate solution was added to the slurry liquid as appropriate, and air was blown in while adjusting the pH of the slurry liquid to 10 to proceed the oxidation reaction. In the meantime, while checking the unreacted ferrous hydroxide concentration and examining the rate of progress of the reaction, zinc sulfate was added as appropriate, and the pH of the aqueous solution was adjusted to 9 at the beginning of the oxidation reaction and to pH at the middle of the reaction. 8, the distribution of metal elements in the magnetic iron oxide was controlled by adjusting the pH stepwise to 6 in the later stage of the reaction, and the oxidation reaction was completed.

  Next, in order to contain the aluminum element, the water-soluble aluminum salt is reduced to 0.20% in terms of aluminum element with respect to the produced particles in the alkaline suspension in which the magnetic iron oxide particles containing the silicon element are produced. Then, the pH was adjusted to a range of 6 to 8 and precipitated as aluminum hydroxide on the surface of magnetic iron oxide.

  Subsequently, the magnetic iron oxide which has an aluminum element on the magnetic iron oxide surface was obtained by filtering, washing with water, drying, and crushing. The produced magnetic iron oxide particles were washed and filtered and dried by a conventional method.

  Since the primary particles of the obtained magnetic iron oxide particles are aggregated to form aggregates, a compressive force and a shear force are applied to the aggregates of magnetic iron oxide particles using a mix muller. The aggregate was crushed to make the magnetic iron oxide particles primary particles, and the surface of the magnetic iron oxide particles was smoothed to obtain magnetic iron oxide 1 having the characteristics shown in Table 4.

<Production Examples 2 to 5 of magnetic iron oxide particles>
Magnetic iron oxides 2 to 5 having the physical properties shown in Table 4 were obtained by changing the amount of sodium silicate, zinc sulfate, water-soluble aluminum salt added, the timing of addition, and the pH of the aqueous solution.

[Example 1]
Binder resin 1 100 parts by mass Magnetic iron oxide 1 100 parts by mass Monoazo iron compound (formula VI) 2 parts by mass 3,5-di-t-butylsalicylate aluminum compound (formula VIII) 0.5 mass Parts / Fischer-Tropsch wax (DSC endothermic peak temperature: 105 ° C., Mw: 2500, Mn: 1500, SP value: 8.4) 4 parts by mass The above raw materials were premixed with a Henschel mixer and then set to 150 ° C. and 250 rpm. Kneading was performed using a biaxial kneading extruder (PCM30: manufactured by Ikegai Iron Works Co., Ltd.). The obtained kneaded product is cooled and coarsely pulverized with a cutter mill, and then the obtained coarsely pulverized product is used with a turbo mill (T-250: manufactured by Turbo Kogyo Co., Ltd.) so that the temperature at the outlet becomes 45 ° C. Set and finely pulverize, and the finely pulverized powder obtained is classified by a fixed wall type air classifier, and a toner particle having a weight average particle diameter (D4) of 6.4 μm and a toner particle size distribution of 4.00 μm or less. Thus, negatively chargeable magnetic toner particles having a proportion of 23.2% by number and a proportion of toner particles having a particle size of 10.1 μm or more in the volume distribution of 0.8% by volume were obtained.

To 100 parts by mass of the toner particles, negatively chargeable hydrophobic silica fine powder (dry silica having a BET specific surface area of 200 m ² / g, hexamethyldisilazane 10 mass% and dimethyl silicone oil (viscosity 100 mm ² / s) 20 mass%). Hydrophobization treatment: 1.2 parts by mass of methanol wettability 80%, BET specific surface area 120 m ^{2 /} g) was externally added and mixed with a Henschel mixer to obtain toner 1. Table 5 shows the prescription of toner 1 and Table 6 shows the physical properties of toner 1.

  This toner was evaluated for the following items.

[Fixing test]
-Fixing start temperature Laser beam printer manufactured by Hewlett-Packard Co., Ltd .: The fixing device of LaserJet 4100 was taken out, and the fixing temperature of the fixing device could be arbitrarily set, and an external fixing device was used so that the process speed was 290 mm / sec. . This external fixing device is temperature-controlled every 5 ° C. within the range of 160 to 220 ° C., and is developed on plain paper (75 g / m ² ) paper (solid toner development amount on paper set to 0.6 mg / cm ² ) The fixed image is fixed, and the obtained image is rubbed 5 times with sylbon paper applied with a load of 4.9 kPa, and the point at which the density reduction rate of the image density before and after the rub is 10% or less is the fixing start temperature. It was. The lower this temperature, the better the low-temperature fixability.

・ High-temperature offset temperature For high-temperature offset property, the process speed is set to 100 mm / sec, the temperature is adjusted every 5 ° C. within the range of 200 to 240 ° C., the unfixed image is fixed, and the stain due to the offset phenomenon on the image is visually observed. The generated temperature was defined as the high temperature offset temperature. The higher this temperature, the better the high temperature offset property.

[Development durability test]
Image density after endurance under normal temperature and humidity environment Laser beam printer manufactured by Hewlett Packard: LaserJet 4100 (A4 vertical 24 sheets / min :) was remodeled to double the process speed (290 mm / sec), and normal temperature and normal humidity (23 In the environment of 60 ° RH, the transfer paper (A4 size) of 75 g / m ² was used as the transfer paper, and 1000 E character pattern images with an image area ratio of 4% were formed, and then a solid black image was obtained. Then, the image density was measured. The image density was measured by measuring the reflection density using a SPI filter with a Macbeth densitometer (manufactured by Macbeth Co.), and the five-point average was calculated.

・ Charge-up evaluation In addition, in a normal temperature and low humidity (23 ° C., 5% RH) environment, 75 g / m ² transfer paper (A4 size) was used as the transfer paper, and double-sided printing of images with an image area ratio of 1% was performed. 5000 sheets were continuously taken. Thereafter, 10 solid black images were output, and the image density was measured in the same manner as the previous solid black image density measurement. The first solid black image density and the tenth solid black image density are shown in Table 7 below. If there is no difference in image density, it indicates that the image is not charged up. If the image is charged up, the image density of the first image is thin and the image density of the 10th image tends to be high.

・ Degradation of image density after standing in a high temperature and high humidity environment Also, after performing a 5000-sheet printing test in a high temperature and high humidity (32.5 ° C., 80% RH) environment, the solid black image is output by leaving it for 3 days. Then, the image density was measured, and a decrease in the image density after being left in a high temperature and high humidity environment was confirmed.

[End offset]
After 100 images are printed on A5 size transfer paper, 100 images are continuously printed on A4 size transfer paper, and the end offset occurs at the end of A4 size paper. Was visually observed and evaluated according to the following criteria. Table 7 shows the evaluation results of Toner 1.
A: No occurrence B: Disappears by the 10th sheet C: Disappears by the 30th sheet D: Disappears by the 50th sheet E: Does not disappear even after 50 sheets [Examples 2 to 8]
Toners 2 to 8 were obtained in the same manner as in Example 1 except that the toner material configuration shown in Table 5 was changed. Table 5 shows the toner formulation, and Table 6 shows the physical properties of the obtained toner. The obtained toner was evaluated in the same manner as toner 1. Table 7 shows the evaluation results of the obtained toner.

Example 9
The toner particles obtained in Example 1 were externally mixed with the following external additives using a Henschel mixer to obtain toner 9. Table 6 shows the physical properties of Toner 9.
・ Negatively charged hydrophobic silica fine powder (methanol wet powder) obtained by hydrophobizing dry silica having a BET specific surface area of 200 m ² / g with 10% by mass of hexamethyldisilazane and 20% by mass of dimethyl silicone oil (viscosity 100 mm ² / s). 80%, BET specific surface area 120 m ² / g) 1.35 parts • Negatively chargeable silica fine particle aggregate containing 60% by mass of dimethyl silicone oil (BET specific surface area 2.5 m ² / g) 0.1 part • positive Chargeable melamine resin particles (BET specific surface area 25 m ² / g) 0.08 parts / positively charged strontium titanate particles (BET specific surface area 2.0 m ² / g) 1.0 part And evaluated in the same manner. Table 7 shows the evaluation results of the obtained toner.

<Comparative Examples 1 and 2>
Comparative toners 1 and 2 were obtained in the same manner as in Example 1 except that the toner material constitution shown in Table 5 was used and a fine pulverizer by collision type airflow pulverization was used. Table 5 shows the toner formulation, and Table 6 shows the physical properties of the obtained toner. The obtained toner was evaluated in the same manner as toner 1. Table 7 shows the evaluation results of the obtained toner.

3 is a graph showing the transmittance of the toner 1 in Example 1 with respect to the methanol concentration. It is a schematic sectional drawing of the mechanical grinder which can be used at the grinding | pulverization process in manufacture of the toner of this invention. It is sectional drawing in the D-D 'surface in FIG. It is a perspective view of the rotor in FIG.

Explanation of symbols

212 Swirl chamber 219 Pipe 220 Distributor 222 Bag filter 224 Suction blower 229 Collection cyclone 301 Mechanical pulverizer 310 Stator 311 Powder inlet 312 Rotating shaft 313 Casing 314 Rotor 315 Metering feeder 316 Jacket 320 Rear chamber

Claims (12)

A toner having toner particles containing at least a binder resin containing a polyester resin as a main component, a wax and a colorant,
When the wettability of the toner with respect to the mixed solvent of methanol and water is measured by the transmittance of light having a wavelength of 780 nm, the methanol concentration when the transmittance is 80% is in the range of 45 to 65% by volume, and the transmittance When the methanol concentration is 10%, the methanol concentration is in the range of 45 to 65% by volume,
The melt index (MI) of the toner at 125 ° C. and a load of 5 kg is 0.1 to 10 g / 10 min.
The toner contains 5 to 40% by mass of a resin component insoluble in tetrahydrofuran (THF insoluble matter) with respect to the binder resin.
In the chromatogram obtained by measuring the tetrahydrofuran-soluble content of the toner by gel permeation chromatography, the ratio of components having a main peak in the molecular weight region of 3000 to 20,000 and having a molecular weight of 10,000 or less in the tetrahydrofuran-soluble content is A toner comprising 50% by mass or more.   The polyester resin has i) a low molecular weight polyester component having a main peak molecular weight of 3000 to 20,000 and having a tetrahydrofuran insoluble content of 0 to 3% by mass, and ii) 10 to 60% by mass of tetrahydrofuran insoluble. 2. The toner according to claim 1, wherein the toner comprises a crosslinked polyester component having a component and a mass ratio of the crosslinked polyester component to the low molecular weight polyester component is 10:90 to 90:10.   The toner according to claim 2, wherein the crosslinked polyester component has a melt index of 0.1 to 10 g / 10 min at 190 ° C. under a load of 10 kg.   The toner according to claim 2, wherein the crosslinked polyester component contains, as monomer components, a trivalent or higher polyvalent carboxylic acid and a trivalent or higher polyhydric alcohol.   The trihydric or higher polyhydric alcohol is an oxyalkylene ether of a novolak type phenol resin, and the trihydric or higher polyhydric carboxylic acid is trimellitic acid or trimellitic anhydride. toner.   The toner particles are 0.1 to 5 parts by mass of an aluminum aromatic hydroxycarboxylic acid compound with respect to 100 parts by mass of the binder resin, and 0.1 to 10 parts by mass of a monoazo iron compound with respect to 100 parts by mass of the binder resin. The toner according to claim 1, further comprising:   7. The toner according to claim 1, wherein the toner particles contain 30 to 200 parts by mass of a magnetic material with respect to 100 parts by mass of the binder resin.   The toner according to claim 7, wherein an isoelectric point obtained from a zeta potential of the magnetic material is pH 5 to 9, and a solubility parameter (SP value) of the wax is 9 or less.   When the transmittance is 80%, the methanol concentration is in the range of 50% by volume to less than 65% by volume, and when the transmittance is 10%, the methanol concentration is in the range of 50% by volume to less than 65% by volume. The toner according to claim 1, wherein the toner is a toner.   10. The toner according to claim 1, wherein the toner has a Carr jetting index greater than 80 and a Carr fluidity index greater than 60. 11.   The toner contains at least a hydrophobic silica fine powder charged to the same polarity as the toner and a fine particle aggregate charged to the same polarity as the toner and containing 20 to 90% by mass of silicone oil or silicone varnish. The toner according to claim 1, wherein the toner is a toner.   The toner includes at least a hydrophobic silica fine powder that is charged to the same polarity as the toner, a fine particle aggregate that is charged to the same polarity as the toner and contains 20 to 90% by mass of silicone oil or silicone varnish, and the reverse of the toner. 11. The toner according to claim 1, comprising a resin fine particle and a metal oxide that are charged in a polar manner.

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