JP2007156449A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner which is effective in alleviation of all of a "void" and "scattering" in an image forming process, and is particularly excellent in image stability in image formation including a transfer process using an intermediate transfer member and a fixing process of low temperature and low pressure. <P>SOLUTION: The degrees of aggregation at the time of compression and non-compression of the toner and a peak temperature (Tsc) of the highest endothermic peak when the toner is measured with a differential scanning calorimeter (DSC) lies in a specified range. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

While reductions in the amount of CO ₂ emissions are being screamed worldwide, technologies related to energy saving have become essential. Copying apparatus and with respect to a printer, in reality is using the fixing device power most of, the reduction of emissions CO _2, it is effective to use a small on-demand fixing amount of power required. Since such on-demand fixing is performed with a small amount of heat, it becomes low-temperature fixing. Further, in order to warm the fixing device with a small amount of heat, it is necessary to reduce the size and weight of the fixing device. For this reason, it is difficult to maintain the conventional fixing pressure, resulting in light pressure fixing. In order to perform fixing at such a low temperature and light pressure, the toner has been improved by various approaches from the viewpoint of the physical properties of the toner, and in particular, it is considered effective to lower the melting point of the release agent. However, when a toner containing a low melting point release agent is used, there are problems such as a decrease in development stability and a decrease in image quality. In particular, it is easy for “spotting” that the inside of a thin line to fall out, and it is necessary to improve it. With respect to the problem of “missing”, various approaches from the viewpoint of the physical properties of the toner have been studied. In recent years, it has been proposed to use a spherical toner.

  In recent years, the digitization of data has progressed, and in addition to the exchange of electronic data, analog data is read and digitized using equipment. For example, there are a wide variety of types such as reading by a mobile phone and a bar coder. In the situation where such a reading symbol is output to a medium by a copying apparatus or a printer and used, the fine line reproducibility is required more than before. On the other hand, there are a wide variety of media to be output, and a technology that supports output to various media is also important. As such a technique, there is a technique using an intermediate transfer member in a transfer process. However, when an intermediate transfer member is used, since the number of times of transfer increases, a phenomenon that toner scatters, that is, so-called “scattering” tends to occur, and thin line reproducibility tends to deteriorate. In order to improve this "scattering", improvements have been made by various methods from the viewpoint of the physical properties of the toner. On the other hand, there are problems such as being likely to cause deterioration.

  Under such a technical background, a toner having an excellent development stability is effective for both improvement of “collapse” in fixing at low temperature and light pressure and improvement of “scattering” in a process using an intermediate transfer member. The current situation is what is required. As a technique for improving the development stability, for example, there has been proposed one that suppresses the fusion between the toner and the member (Patent Document 1). However, although the toner proposed here has a small degree of aggregation under compression and is considered to be effective in improving “blank”, it can be said that it is sufficiently effective against “scattering”. Absent. In addition, as a technique for improving “missing”, for example, a toner that defines a degree of aggregation under compression has been proposed (Patent Document 2). However, it cannot be said that it is effective enough for the improvement of “hollow-out”, and it cannot be said that it is effective enough for “scattering”, especially in a system using an intermediate transfer member. There was much room for improvement.

Japanese Patent No. 3002063 Japanese Patent Laid-Open No. 10-171151

  Image formation in electrophotographic technology is generally composed of development-transfer-fixing steps. “Flying” occurs mainly in the development process and the transfer process, and “missing” occurs mainly in the transfer process.

  In the developing process, the toner is released from the sleeve or the carrier due to the developing bias, and if it is an alternating electric field, it is supposed to fly to the drum having the electrostatic latent image while reciprocating. At this time, if the fluidity is too high, it is considered that the toner scatters to the periphery as if spilled from the toner laminated on the electrostatic latent image.

  In the transfer step, transfer is performed by pressing the toner layer formed on the drum against a transfer roller via an intermediate transfer member or a transfer material. When the fluidity of the toner is too high at the time of compression, the toner layer collapses due to the pressure at the time of transfer, and considerable “scattering” occurs. Furthermore, in systems that use an intermediate transfer body, there is a secondary transfer process in which all the colors are transferred to the transfer material, and there are more transfer processes than in a system that does not use an intermediate point copy. Will occur. On the other hand, if the toner tends to harden during compression, the toner hardens due to the pressure during the transfer and remains on the drum, resulting in “slow-out”.

  In the fixing process, if the toner fluidity is too low or the melting point of the toner is too high at the time of toner compression, the toner remains on the transfer material and “collapse” occurs. In particular, in the case of low-temperature and light-pressure fixing, the toner is hardly fixed on the recording medium, and this phenomenon is likely to occur.

  Accordingly, an object of the present invention is to provide a toner that is effective in improving “blank” and “scattering” in each of the above steps. It is another object of the present invention to provide a toner having excellent image stability even in image formation including a transfer process using an intermediate transfer member and a low-temperature and light-pressure fixing process.

  As a result of intensive research to solve the above problems, the inventors of the present invention have measured the agglomeration degree during non-compression, the agglomeration degree during compression, and a differential scanning calorimeter (DSC) among parameters representing toner physical properties. It has been found that the peak temperature of the maximum endothermic peak is involved in slipping and hollowing out.

That is, the configuration of the present invention is as follows.
Toner particles containing at least a binder resin, a release agent, a colorant, and a toner containing at least an inorganic fine powder,
(I) The toner has a degree of aggregation Y1 during compression (200 kPa) and a degree of aggregation Y2 during non-compression of 15 ≦ Y1 ≦ 35 and 7 ≦ Y2 ≦ 15.
(Ii) The toner has a maximum endothermic peak in a temperature range of 30 to 200 ° C. in an endothermic curve measured by a differential scanning calorimeter (DSC), and the peak temperature Tsc (° C.) of the maximum endothermic peak is 60 ≦ Tsc ≦ 130.
The present invention also provides a charging step for charging the image carrier, a latent image forming step for forming an electrostatic latent image on the image carrier charged in the charging step, and an electrostatic image formed on the image carrier. The latent image is developed with toner to form a toner image, the toner image on the image carrier is transferred to a transfer material via an intermediate transfer member, and the toner image is transferred to a fixing nip. An image forming method having a fixing step of fixing by pressing to a transfer material at a portion,
The surface pressure at the fixing nip is 5.0 to 11.0 N / m ² ;
The toner is used as the toner.

According to the present invention, it is possible to provide a toner that is effective in improving “blank” and “scattering” in each step of image formation and has excellent development stability.

  The toner of the present invention is characterized in that the degree of aggregation Y1 upon compression is 15 ≦ Y1 ≦ 35.

  The degree of aggregation is a value obtained from a sieve using three types of sieves having different openings, and the amount obtained from the residual amount on each sieve. In the present invention, it indicates a value calculated by a method for measuring the degree of aggregation described later. . In the present invention, the degree of aggregation Y1 during compression is the degree of aggregation when 200 kPa is added. In the actual transfer process, in addition to the pressure at the simple transfer nip at rest, the transfer depends on various factors such as the peripheral speed difference between the drum and the intermediate transfer member and the image width formed on the drum during operation. Since the pressure applied to the toner layer at the time fluctuates, it is difficult to define the physical properties of the toner based on the degree of aggregation when an actual pressure is applied. Here, if a uniform pressure is applied to a flat member having no toner layer, the pressure at the transfer nip is approximately 10 to 30 kPa, and if the toner layer is present, the additional pressure is increased. Therefore, in the present invention, it was considered effective to define a numerical range when the toner is multiplied by 200 kPa from the correlation with “Tobichiri”. A specific compression method will be described later. In this specification, the non-compression aggregation degree Y2 is the aggregation degree of the toner before the compression.

  The degree of aggregation Y1 during toner compression is Y1 ≦ 35, preferably Y1 ≦ 30 (see FIG. 1). When the degree of aggregation during compression is in the above range, the toner can be prevented from solidifying even when the toner is compressed in the transfer step. Further, it is possible to suppress the occurrence of voids that occur when toner remains on the image carrier (for example, a photosensitive drum). Y1 is Y1 ≧ 15. When it is within this range, it is possible to suppress the toner layer from collapsing and causing toner scattering during compression of the toner in the transfer process and the fixing process.

The toner of the present invention is characterized in that the degree of aggregation Y2 at the time of non-compression is 7 ≦ Y2 ≦ 15.
Y2 is Y2 ≧ 7, preferably Y2 ≧ 9 (see FIG. 1), and when the degree of aggregation at the time of non-compression is in the above range, it occurs when the toner flies to the drum in the development process. Can be suppressed. Y2 is Y2 ≦ 15. When Y2> 15, the toner fluidity is poor and it becomes difficult to stir the toner in the developing device. In particular, in a replenishing system, the replenished toner has a poor rise in charge, and fog is likely to occur.

  The degree of aggregation Y1 and Y2 can be obtained by appropriately adjusting the pulverization method at the time of production and the constituent components of the toner. It is also an effective means to adjust the circularity of the toner so as to satisfy a specific rule.

The average circularity of a toner having an equivalent circle diameter of 2.00 μm or more is R, the equivalent circle diameter of each circle having an equivalent circle diameter of 2.00 μm or more and less than 3.00 μm, 3.00 μm or more and less than 6.92 μm, or 6.92 μm or more and less than 12.66 μm. When the average circularity of the toner in the range is r (a), r (b), and r (c), R, r (a), r (b), and r (c) are expressed by the formula (1). It is preferable to satisfy the relationship of-Formula (4).
0.940 ≦ R ≦ 0.970 Formula (1)
R−0.015 ≦ r (a) ≦ R + 0.015 Formula (2)
R−0.015 ≦ r (b) ≦ R + 0.015 Formula (3)
R−0.015 ≦ r (c) ≦ R + 0.015 Formula (4)

More preferably, r (a), r (b), and r (c) satisfy the relationships of Expressions (5) to (7).
R−0.007 ≦ r (a) ≦ R + 0.007 Formula (5)
R−0.007 ≦ r (b) ≦ R + 0.007 Formula (6)
R−0.007 ≦ r (c) ≦ R + 0.007 Formula (7)

  The average circularity is an average value of circularity. The degree of circularity is an index indicating the degree of unevenness of the particle, and is 1.000 when the particle is a perfect sphere, and becomes smaller as the surface shape becomes more complicated. A method for measuring the average circularity will be described later.

  In the case where the average circularity of the toner is adjusted so as to satisfy the above-described relationship, in addition to being easy to satisfy the regulation relating to the degree of aggregation, it is possible to further improve the voids and scattering. A toner having a low average circularity has large irregularities on the particle surface, and in such a toner, the inorganic fine powder is unevenly distributed in the concave portion, and the inorganic fine powder tends not to exist in the convex portion. When the inorganic fine powder takes such a distribution state, the toner is likely to aggregate when it is subjected to a high pressure in a transfer process or the like, and adheres to the image carrier and easily loses its inside. On the other hand, when the average circularity is too high, the fluidity of the toner tends to be high and scattering tends to occur. In addition, it is important to adjust not only the average circularity of the entire toner but also the average circularity of the toner in each of the coarse powder, medium powder, and fine powder bands. Not different is important when suppressing voids and splashes.

  Further, the average circularity r (a) in the toner having an equivalent circle diameter of 2.00 μm or more and less than 3.00 μm is smaller than the average circularity R in the toner having an equivalent circle diameter of 2.00 μm or more. In the case of 015, high fluidity can be obtained, but cleaning defects are likely to occur, for example, the fine particle toner passes through the cleaning blade. Furthermore, the toner is easily packed in the toner container or the developing device, and image defects due to the formation of aggregates tend to occur, or the uniformity of the solid image tends to deteriorate. Also, in a system that collects transfer residual toner simultaneously with development, the recoverability in development becomes insufficient, and the toner that cannot be collected may move around on the photosensitive drum and cause fogging.

  The average circularity r (a) of the toner having an equivalent circle diameter of 2.00 μm to less than 3.00 μm is r (a) <R− with respect to the average circularity R of the toner having an equivalent circle diameter of 2.00 μm or more. In the case of 0.015, the circularity on the fine powder side becomes indefinite, so that the contact area between the toner and the carrier and other members is increased, and the toner separation is inhibited. In this case, the toner tends to stay in the developing unit without being developed, and continuous use may cause carrier spent or contamination of a member such as a sleeve.

  Further, the average circularity r (c) of the toner having an equivalent circle diameter of 6.92 μm or more and less than 12.66 μm is smaller than the average circularity R of the toner having an equivalent circle diameter of 2.00 μm or more, r (c)> R + 0. In the case of 015, it means that the circularity of the toner on the coarse powder side becomes relatively high. Such a toner having a relatively large particle size and a high degree of circularity has a low adhesion to the electrophotographic photosensitive member or the transfer member, and therefore tends to be scattered from the developing device. In addition, since the adhesion between the particles is weakened, when the recording medium carrying the unfixed toner image is conveyed to the fixing device, the unfixed image is disturbed by vibration, and the dot reproducibility may deteriorate.

Further, the average circularity r (c) of the toner having an equivalent circle diameter of 6.92 μm or more and less than 12.66 μm is r (c) <R− with respect to the average circularity R of the toner having an equivalent circle diameter of 2.00 μm or more. In the case of 0.015, since a large concave portion is present on the toner surface, the added external additive does not work effectively, and the fluidity tends to be lowered. As a result, the probability of contact between the carrier or sleeve and the toner is reduced, the charge amount is low, the charge amount distribution is widened, and selective development may occur. In addition, the contact area with the drum increases, and the adhesion may increase.
Further, in a toner having a particle diameter with an equivalent circle diameter of 2.00 μm or more, the content of the toner with an equivalent circle diameter of 2.00 μm or more and less than 3.00 μm is 1.0 to 10.0% by number, 3.00 μm.
The toner content of 6.92 to less than 6.92 is preferably 70.0 to 90.0% by number, and the toner content of 6.92 μm to less than 12.66 μm is preferably 5.0 to 20.0% by number. More preferably, the content of toner having an equivalent circle diameter of 2.00 μm or more and less than 3.00 μm is 1.0 to 6.0% by number, and the content of toner having a circle equivalent diameter of 3.00 μm or more and less than 6.92 is 80.0 to The content of toner of 90.0% by number, 6.92 μm or more and less than 12.66 μm is 5.0 to 15.0% by number.

  The toner has a weight average particle diameter (D4) of 3.0 to 7.0 μm, preferably 5.0 to 6.0 μm. When the weight average particle diameter exceeds 7.0 μm, the latent image of dots and lines cannot be faithfully developed with toner, and in particular, reproduction of photographic images or reproduction of fine lines is inferior. On the other hand, if the weight average particle size is less than 3.0 μm, it becomes difficult to control charging and toner fluidity, and a stable image cannot be obtained.

  Further, by setting the maximum valley depth Rv (nm) of the concave portion on the toner particle surface to a constant size, it is possible to satisfactorily suppress voids and scattering.

  Rv (nm) can be measured using a scanning probe microscope, and specifically, can be measured by the method described later.

  The toner particles contained in the toner have an average valley depth Rvm (nm) which is an average value of Rv (nm), preferably Rvm ≦ 200, more preferably Rvm ≦ 180. By setting the average valley depth Rvm (nm) to Rvm ≦ 200, the irregularities on the surface of the toner particles can be made uniform and fine, and the degree of aggregation Y1 when the toner is compressed can be easily set to Y1 ≦ 35. It becomes. As a result, toner adhesion to the drum or transfer material and toner adhesion are suppressed, and voids during transfer and fixing are less likely to occur. On the other hand, when Rvm> 200, when the inorganic fine powder is added to the surface of the toner particles, the inorganic fine powder collects in the concave portions, and the convex portions of the toner particles tend to be exposed. In particular, when pressure is applied to the toner in the transfer process or the fixing process, more inorganic fine powder collects in the recesses, and the exposure of the surface of the toner particles increases. Such exposure of the toner particles can be suppressed by adding a large amount of inorganic fine powder in the toner production process, but at the same time, since the inorganic fine powder is further laminated in the concave portion, the inorganic fine powder on the surface side and the toner are also laminated. Adhesiveness with the particles is lowered, causing various adverse effects such as a poor spent on the carrier and the charging roller.

  Further, the Rvm (nm) of the toner particles contained in the toner is preferably Rvm ≧ 120, more preferably Rvm ≧ 130. By setting Rvm (nm) to Rvm ≧ 120, moderate unevenness is imparted to the toner surface, and it becomes easy to set Y2 to Y2 ≧ 7. As a result, scattering during development is less likely to occur. On the other hand, when Rvm <120, the unevenness of the toner surface becomes flat, and the fluidity is enhanced by the effective action of the inorganic fine powder, and Y2 tends to be Y2 <7. In this case, the fluidity of the toner can be lowered by reducing the addition amount of the inorganic fine powder, but the change in the physical properties of the toner surface due to the embedding of the inorganic fine powder in the toner particles due to long-term use is large. As a result, problems such as fogging due to a change in toner charge and fluctuations in image density occur.

  From the above, it is preferable that the average valley depth Rvm (nm) of the recesses on the toner particle surface is 120 ≦ Rvm ≦ 200.

The toner of the present invention has a maximum endothermic peak in the temperature range of 30 to 200 ° C. in the endothermic curve measured with a differential scanning calorimeter (DSC), and the peak temperature Tsc (° C.) of the maximum endothermic peak is 60 ≦ Tsc ≦ 130. A method for measuring Tsc (° C.) will be described later.

  The toner of the present invention has a Tsc (° C.) of Tsc ≧ 60, preferably Tsc ≧ 65. By prescribing Tsc (° C.) to the above value, it is possible to prevent the toner from solidifying during compression and to improve voids in the transfer process. On the other hand, when Tsc <60, the hardness of the toner is low, so that the toner is easily solidified by the transfer pressure. Further, Tsc (° C.) satisfies Tsc ≦ 130, preferably Tsc ≦ 100, and more preferably Tsc ≦ 85. By prescribing Tsc (° C.) to the above value, fluidity is excellent even at low temperatures, and good fixability is exhibited even at low temperature and light pressure fixing such as on-demand fixing. On the other hand, when Tsc> 130, the hardness of the toner becomes too high, and sufficient fixing is difficult at low temperature and light pressure.

  The range of Tsc (° C.) of the toner can be obtained by appropriately adjusting the material of each component forming the toner. Among these, it is effective to adjust the melting point of the release agent contained in the toner particles. A mold release agent having a low melting point tends to have a lower hardness than a mold release agent having a high melting point. Therefore, a toner containing a release agent having a melting point that is too low is likely to be hardened due to the transfer pressure, and the toner tends to be lost when the Tsc (° C.) of the toner satisfies Tsc <60. On the other hand, a toner containing a release agent having an excessively high melting point has a poor ability to exude the release agent at the time of fixing. Therefore, if the Tsc of the toner is Tsc> 130, the fixability is poor. Therefore, a release agent having as short a molecular chain as possible and having less steric hindrance and excellent fluidity (mobility) is better for bleeding, and a toner containing such a release agent is excellent in fixability.

  The release agent added to the toner is not particularly limited as long as it is suitable for satisfying the physical properties of the toner of the present invention. For example, low molecular weight polyethylene, low molecular weight polypropylene, olefin copolymer, Aliphatic hydrocarbon waxes such as crystallin wax, paraffin wax, Fischer-Tropsch wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; block copolymers of aliphatic hydrocarbon waxes; carnauba wax, behenic acid Examples thereof include waxes mainly composed of fatty acid esters such as behenyl and montanic acid ester wax; and those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax.

  Examples thereof include a partially esterified product of a fatty acid such as behenic acid monoglyceride and a polyhydric alcohol; a methyl ester compound having a hydroxyl group obtained by hydrogenating vegetable oils and the like. Particularly preferred waxes are aliphatic hydrocarbon waxes such as paraffin wax, polyethylene, and Fischer-Tropsch wax that have a short molecular chain and little steric hindrance and excellent fluidity.

  The molecular weight distribution of the release agent is preferably such that the main peak is in the region of molecular weight 350-2400, more preferably in the region of 400-2000. A toner containing a release agent having such a molecular weight distribution has favorable thermal characteristics. The addition amount of the release agent is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the binder resin.

The toner preferably has a light transmittance (%) at a wavelength of 600 nm with respect to a dispersion obtained by dispersing the toner in an aqueous solution of 45% by volume of methanol in the range of 30 to 70%, more preferably 35%. ~ 50%.
In the measurement of the transmittance, the toner is forcibly dispersed once in a mixed solvent so that the characteristics of each toner particle can be easily obtained, and the light transmittance after a predetermined time is measured. Therefore, it is possible to accurately grasp the tendency of the state of presence of the release agent as the whole toner reflecting the state of presence of the release agent of each toner particle. If a large amount of hydrophobic release agent is present on the toner surface, the toner becomes difficult to disperse in the mixed solvent, and the floated or agglomerated precipitates on the surface of the mixed solvent. become. Conversely, when the amount of the release agent present on the toner surface is small, the amount of hydrophilic binder resin increases, so that the toner is easily dispersed uniformly by the mixed solvent, and the transmittance becomes low.
The toner having the above transmittance of 30 to 70% is one in which the release agent is appropriately exposed on the surface of the toner particles, and such a toner can be fixed with a light pressure load. , The occurrence of voids can be suppressed. In addition, it is possible to achieve a wide fixing area, prevent the release agent component from being detached from the toner, and suppress contamination of the developing member even during long-term use.

  The binder resin contained in the toner particles is not particularly limited as long as it is suitable for satisfying the physical properties of the toner of the present invention, and known binder resins can be used in combination. Among them, it is effective to use a resin containing a polyester unit in order to obtain a toner excellent in low-temperature fixability and charge rise. In order to impart uniform chargeability, it is also effective to use a resin containing a vinyl polymer unit that improves the dispersibility of the release agent. Therefore, the binder resin used in the toner of the present invention includes (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl polymer unit, or (c) a hybrid resin and a vinyl polymer. Or (d) a mixture of a polyester resin and a vinyl polymer, or (e) a mixture of a hybrid resin and a polyester resin, or (f) a polyester resin, a hybrid resin, and a vinyl polymer. Resins selected from any of the mixtures are preferred. Among these, it is particularly preferable to use one containing a hybrid resin.

  In the present specification, the “polyester unit” indicates a portion derived from polyester, and indicates a polyester skeleton portion in a polyester resin or a hybrid resin. The “vinyl polymer unit” indicates a portion derived from a vinyl polymer, and indicates a vinyl polymer skeleton portion in a vinyl resin or a hybrid resin. The polyester monomer constituting the polyester unit is a polyvalent carboxylic acid component and a polyhydric alcohol component, and the vinyl polymer unit is a monomer component having a vinyl group.

  As the polyester monomer constituting the polyester unit, alcohol and carboxylic acid, carboxylic acid anhydride, carboxylic acid ester or the like can be used as a raw material monomer. Specifically, for example, as the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, Opentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

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

  Examples of the carboxylic acid component include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; Succinic acid substituted with 12 alkyl groups or anhydrides thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof.

  Among these, in particular, a bisphenol derivative represented by the following general formula (1) is used as a diol component, and a carboxylic acid component (for example, fumaric acid) composed of a divalent or higher carboxylic acid or an acid anhydride thereof or a lower alkyl ester thereof. A polyester resin obtained by polycondensation using acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component is preferable because it imparts good charging characteristics to the toner.

  Examples of the trivalent or higher polyvalent carboxylic acid component for forming a polyester resin having a crosslinking site include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2 , 4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof. The amount of the trivalent or higher polyvalent carboxylic acid component is preferably 0.1 to 1.9 mol% based on the total monomer.

  Further, when a hybrid resin having a polyester unit and a vinyl polymer unit is used as the binder resin, further improved release agent dispersibility, low-temperature fixability, and offset resistance can be expected. The “hybrid resin component” used in the present invention means a resin in which a vinyl polymer unit and a polyester unit are chemically bonded. For example, a polyester unit and a vinyl polymer unit polymerized using a monomer having a carboxylic ester group such as an acrylate ester are bonded together by a transesterification reaction. A graft copolymer (or block copolymer) in which a vinyl polymer is a trunk polymer and a polyester unit is a branch polymer is preferable.

The following are mentioned as a vinyl-type monomer for producing | generating a vinyl-type polymer unit. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3, Derivatives of styrene such as 4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene ; Such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride Vinylated vinyls; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, methacryl Α-methylene aliphatic monocarboxylic acid esters such as dodecyl acid, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, acrylic acid Propyl, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, Acrylic esters such as phenyl chlorate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N- N-vinyl compounds such as vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  In addition, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Alkenyl succinic acid half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester unsaturated dibasic acid half ester; dimethylmaleic acid, dimethyl fumaric acid unsaturated dibasic acid ester; acrylic acid, meta Α, β-unsaturated acids such as rillic acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.

  Further, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

  Further, the vinyl polymer unit of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. Examples of the crosslinking agent used in this case include divinylbenzene and divinylnaphthalene as aromatic divinyl compounds; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate and 1,3-butylene glycol diene. Examples include acrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate and those obtained by replacing acrylate of the above compounds with methacrylate; ether Examples of diacrylate compounds linked by an alkyl chain containing a bond include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene, and the like. Glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate and the above compounds in which acrylate is replaced by methacrylate; diacrylates linked by chains containing aromatic groups and ether linkages Examples of the compounds include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the like The thing which replaced the acrylate of the compound of this with the methacrylate is mentioned.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples include nurate and triallyl trimellitate.

  The binder resin has a main peak in the molecular weight region of 3,500 to 30,000 in the molecular weight distribution measured by gel permeation chromatography (GPC), and preferably has a molecular weight of 5,000 to 20,000. It is preferable that Mw / Mn is 5.0 or more. When the main peak of the binder resin is in a region having a molecular weight of less than 3,500, the hot offset resistance of the toner tends to be insufficient. On the other hand, when the main peak is in the region where the molecular weight exceeds 30,000, sufficient low-temperature fixability of the toner cannot be obtained, and application to high-speed fixing becomes difficult. Moreover, when Mw / Mn is less than 5.0, it becomes difficult to obtain good offset resistance.

  The glass transition temperature (Tg) of the binder resin is preferably 40 to 90 ° C, more preferably 45 to 85 ° C. Further, the acid value of the resin is preferably 1 to 40 mgKOH / g.

  Examples of the polymerization initiator used when producing a vinyl polymer unit used for a binder resin include 2,2′-azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2). , 4-dimethylvaleronitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2,2′-azobisiso Butyrate, 1,1′-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2 , 4-dimethyl-4-methoxyvaleronitrile, 2,2'-azobis (2-methyl-propane), methyl ethyl ketone peroxide, acetylacetone Ketone peroxides such as oxide and cyclohexanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydro Peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, deca Noyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxide Xidicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexyl Sulfonyl peroxide, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy 2-ethylhexanoate, di-t- Chill peroxy hexahydro terephthalate, di -t- butyl peroxy azelate and the like.

  Examples of the method for synthesizing the hybrid resin used in the toner of the present invention include the following production methods (1) to (5).

  (1) Manufacture vinyl polymer, polyester resin, and hybrid resin components, dissolve and swell them in an organic solvent (for example, xylene), add esterification catalyst and alcohol, and conduct transesterification by heating. Can be synthesized.

  (2) After the production of the vinyl polymer unit, the polyester unit and / or the hybrid resin component are reacted in the presence thereof.

  (3) After producing the polyester unit, the vinyl polymer unit and / or the hybrid resin component are reacted in the presence of the polyester unit.

  (4) After producing a vinyl polymer unit and a polyester unit, a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) are reacted in the presence thereof.

  (5) A vinyl monomer and a polyester monomer (alcohol, carboxylic acid, etc.) are mixed to perform addition polymerization and condensation polymerization reaction continuously.

  In the production methods (1) to (5) above, the vinyl polymer unit and / or the polyester unit may have the same molecular weight and cross-linking degree, or may have a plurality of different molecular weights and cross-linking degrees. Polymer units can also be used.

  The colorant is not particularly limited as long as the physical properties of the toner of the present invention are satisfied, and known pigments and dyes can be used alone or in combination. Examples of the colorant include the following.

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

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

  Examples of the color pigment for yellow include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 74, 83, 93, 97, 155, 180, 185, C.I. I. Bat yellow 1, 3, 20 etc. are mentioned.

  As the black pigment, for example, carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black is used. Also, magnetic powder such as magnetite and ferrite, or yellow / magenta / cyan shown above. / The thing etc. which were toned to black using a black coloring agent are mentioned.

The content of the colorant is preferably 1 to 15 parts by mass, more preferably 3 to 12 parts by mass, and still more preferably 4 to 10 parts by mass with respect to 100 parts by mass of the binder resin. . When the content of the colorant is more than 15 parts by mass, the transparency is lowered, and in addition, the reproducibility of intermediate colors as typified by human skin color is likely to be lowered, and further, the chargeability of the toner is stabilized. And the low-temperature fixability becomes difficult to obtain. When the content of the colorant is less than 1 part by mass, the coloring power is low, and a large amount of toner must be used to obtain the density, which may deteriorate the low-temperature fixability.

  The inorganic fine powder contained in the toner is not particularly limited as long as it can be added to the classified toner particles so that the fluidity can be increased as compared with that before the addition. For example, fluororesin powder such as vinylidene fluoride fine powder, polytetrafluoroethylene fine powder, titanium oxide fine powder, alumina fine powder, wet process silica, fine powder silica such as dry process silica, silane coupling agent, Any surface treated with a titanium coupling agent, silicone oil, etc. can be used.

For example, the dry process silica is a fine powder produced by vapor phase oxidation of a silicon halogen compound, which is called dry process silica or fumed silica, and is manufactured by a conventionally known technique. 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 a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. . It is preferable to use a silica fine powder having an average primary particle diameter in the range of 0.001 to 2 μm.

  Further, it is more preferable to use a treated silica fine powder obtained by hydrophobizing a silica fine powder produced by vapor phase oxidation of the silicon halide compound.

  As a hydrophobizing method, it is applied by chemically treating 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.

  As the inorganic fine powder, the above-described dry process silica treated with a coupling agent having an amino group or silicone oil may be used as necessary to achieve the object of the present invention. The inorganic fine powder used in the present invention is preferably used in an amount of 0.01 to 8 parts by mass with respect to 100 parts by mass of the toner particles.

  As described above, various inorganic fine powders can be used in the present invention. Among them, the fine powder surface is preferably treated with silicone oil, more preferably silica fine powder such as dry process silica. It is preferable to use a surface treated with silicone oil. This is because treatment with silicone oil enhances charge retention and makes it difficult for the charge to escape, so that a change in charge caused by leaving the toner is suppressed.

  The inorganic fine powder contains at least an inorganic fine powder (A) having a number average particle size of 20 nm or more and less than 300 nm and an inorganic fine powder (B) having a number average particle size of 5 nm or more and less than 20 nm. It is preferable that at least one of the inorganic fine powder (A) and the inorganic fine powder (B) is surface-treated with silicone oil.

The number average particle diameter of the inorganic fine powder (A) is 20 nm or more and less than 300 nm, and more preferably 20 nm or more and less than 150 nm. When the number average particle diameter of the inorganic fine powder (A) is 20 nm or more and less than 300 nm, the inorganic fine powder (A) is not embedded in the colored particles even if image output is continued for a long period of time. The drum is not in contact with the surface of the colored particles, but the state in which the inorganic fine particles and the drum are in contact with each other can be maintained, and the releasability between the toner and the drum is maintained, and as a result, a decrease in transfer efficiency can be suppressed. . If it is less than 20 nm, the function as a spacer is weakened, and the contribution to the improvement of transferability is reduced. On the other hand, when it exceeds 300 nm, it becomes easy to detach from the colored particles, and it becomes difficult to stably adhere to the surface of the colored particles, and the transfer efficiency tends to be lowered. In addition, the toner may be detached from the toner during development to contaminate the surroundings of the developing device, or the detached fine powder may adhere to the photosensitive drum or the carrier to cause a decrease in charging performance.

  The inorganic fine powder (B) preferably has a number average particle diameter of 5 nm or more and less than 20 nm. If the number average particle diameter of the inorganic fine powder (B) is smaller than 5 nm, the inorganic fine powder (B) is easily embedded in the toner surface over a long period of image output, and the physical adhesion of the fluid toner is increased and the fluidity is increased. May decrease. On the other hand, if it is larger than 20 nm, the effect of imparting fluidity is reduced, and the charging characteristics tend to be unstable.

  More preferably, the inorganic fine powder (B) is treated with silicone oil. By the silicone oil treatment, it is possible to prevent the occurrence of so-called “transfer omission” in which only the edge portion is transferred without transferring the central portion of the line image or character image line on the image. When the silicone oil treatment is not performed, “transfer omission” may occur.

Examples of the inorganic compound that can be used as the inorganic fine powder (A) include silica, alumina, and titanium oxide. In the case of silica, for example, any silica produced by using a conventionally known technique such as a gas phase decomposition method, a combustion method, or a deflagration method can be used, but a silica produced by a sol-gel method can be used. Is particularly preferred. The sol-gel method is a method of removing particles from a silica sol suspension obtained by hydrolyzing and condensing alkoxysilane with a catalyst in an organic solvent in which water is present, and drying to form particles.
Furthermore, the silica surface obtained by the sol-gel method may be used after being hydrophobized, and a silane compound is preferably used as the hydrophobizing agent. Examples of silane compounds include monomethylsilanes such as hexamethyldisilazane, trimethylchlorosilane and triethylchlorosilane, monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane, monoaminosilanes such as trimethylsilyldimethylamine and trimethylsilyldiethylamine, and trimethylacetoxysilane. Of monoacyloxysilane.

The inorganic fine powder (B) is preferably inorganic fine particles having a composition different from that of the inorganic fine particles (A). Different compositions refer to compositions having different configurations, such as different materials, or different surface treatments or shapes even if the materials are the same.
Specific examples of the inorganic fine powder (B) include various metal compounds (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.), nitrides (silicon nitride) Etc.), carbides (such as silicon carbide), metal salts (such as calcium sulfate, barium sulfate, and calcium carbonate), fatty acid metal salts (such as zinc stearate and calcium stearate), carbon black, silica and the like. In particular, silica fine particles treated with silicone oil are preferable. Silica fine particles may be used in combination with a silicone oil treatment and a surface treatment such as a silane compound, an organic silicon compound, or a titanium coupling agent. By adding silica fine particles treated with silicone oil to the toner, good fluidity and chargeability can be imparted to the toner.

Further, the ratio of the surface of the toner particles covered with the inorganic fine powder (coverage) is 60% or more, the coverage of the inorganic fine powder (A) is F (A), and the inorganic fine powder (B). It is more preferable that the relationship between F (A) and F (B) satisfies the formula (8), where F is a coverage ratio.
1.0 ≦ F (B) / F (A) ≦ 10.0 Formula (8)

Here, the coverage F of each inorganic fine powder is calculated | required from the following Formula (9).
F = (3 ^1/2 × D4 × ρt) / (2π × da × ρa) × C Formula (9)
[Where D4 is the weight average particle diameter of the toner, ρt is the specific gravity of the toner, da is the number average particle diameter of the inorganic fine powder, ρa is the specific gravity of the inorganic fine powder, and C is the inorganic fine powder relative to 100 parts by mass of the toner particles. Represents the amount added. ]

  When the coverage of the inorganic fine powder on the surface of the toner particles is 60% or more and the equation (8) is satisfied, transfer omission such as a line image is suppressed, and good transfer is possible. When F (B) / F (A) is smaller than 1.0, steric hindrance due to the size of the inorganic fine powder (A) occurs, and the effect of adding the inorganic fine powder (B) is hindered. It becomes difficult to obtain a sufficient effect of adding the fine powder together. On the other hand, if F (B) / F (A) is greater than 10.0, the releasability of the toner from the peripheral members decreases, and the desired effect obtained by using different inorganic fine powders together cannot be obtained sufficiently. . In addition, it is more preferable that F (B) / F (A) is 1.0 to 5.0.

  The amount of the inorganic fine powder (A) added is preferably 0.3 to 5.0 parts by mass, more preferably 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the toner particles.

  The amount of the inorganic fine powder (B) added is preferably 0.1 to 5.0 parts by mass, more preferably 0.5 to 2.5 parts by mass with respect to 100 parts by mass of the toner particles.

  In addition, the inorganic fine powder includes inorganic fine powder (A) and inorganic fine powder (B) as the inorganic fine powder. Further, the inorganic fine powder (A) and the inorganic fine powder (B) are different in BET or crystal type from titanium oxide. Or it is preferable to contain 1 or more types of inorganic fine powder chosen from aluminum oxide.

  The inorganic fine powder (A) and the inorganic fine powder (B) preferably contain at least one inorganic fine powder selected from titanium oxide or aluminum oxide from the viewpoint of improving fluidity and chargeability. By improving the fluidity, the toner is sufficiently charged by stirring in the developing device, and the toner becomes effective against fogging and toner scattering. In general, if the toner is left in a high-temperature, high-humidity environment, the absolute charge level will decrease, and after the last image is output, the image will not be output for a long period of time. However, when such an inorganic fine powder is externally added, a more remarkable effect is exhibited against fogging and toner scattering, and this problem can be improved.

  In addition, various inorganic oxide fine particles, fine particles obtained by subjecting them to hydrophobic treatment, vinyl polymer, zinc stearate, resin fine particles, and the like can be used as external additives. The amount of these external additives added is preferably in the range of 0.02 to 5% by mass with respect to the total mass of the toner particles.

Further, a charge control agent can be further added to the toner. Examples of the charge control agent include organometallic complexes, metal salts, and chelate compounds such as monoazo metal complexes, acetylacetone metal complexes, hydroxycarboxylic acid metal complexes, polycarboxylic acid metal complexes, and polyol metal complexes. Further, carboxylic acid derivatives such as metal salts of carboxylic acids, carboxylic acid anhydrides and esters, and condensates of aromatic compounds are also included. In addition, phenol derivatives such as bisphenols and calixarene are also used, but from the viewpoint of charge rise, a metal compound of an aromatic carboxylic acid is preferably used. The addition amount of the charge control agent used in the toner of the present invention is 0.2 to 10 parts by mass, preferably 0.3 to 7 parts by mass with respect to 100 parts by mass of the binder resin. This is because if the amount is less than 0.2 parts by mass, the effect of improving the charge rise is not sufficiently obtained, and if the amount is more than 10 parts by mass, environmental fluctuation tends to increase.

  The toner of the present invention can be suitably used for nonmagnetic one-component development, but is preferably used for a two-component developer. In this case, the toner is used by mixing with a magnetic carrier.

  Examples of the magnetic carrier include surface oxidized or unoxidized iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, rare earth metal particles, alloy particles thereof, oxide particles, ferrite and the like. A known carrier such as a resin carrier made by mixing these metals with a resin can be used without particular limitation. The coated carrier obtained by coating the surface of the magnetic carrier particles with a resin is particularly preferable in a developing method in which an AC bias is applied to the developing sleeve. As a coating method, a method in which a coating solution prepared by dissolving or suspending a coating material such as a resin in a solvent is adhered to the surface of the magnetic carrier core particle, and a method in which the magnetic carrier core particle and the coating material are mixed with powder. A conventionally known method can be applied.

  Examples of the coating material on the surface of the magnetic carrier core particle include silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. These are used alone or in plural. The treatment amount of the coating material is preferably 0.1 to 30% by mass (preferably 0.5 to 20% by mass) with respect to the carrier core particles. These carriers have an average particle diameter of 10 to 100 μm, preferably 20 to 70 μm.

  When a two-component developer is prepared by mixing the toner of the present invention and a magnetic carrier, the mixing ratio is usually 2 to 15% by mass, preferably 4 to 13% by mass, as the toner concentration in the developer. Good results are obtained. If the toner concentration is less than 2% by mass, the image density tends to decrease, and if it exceeds 15% by mass, fogging or in-machine scattering tends to occur.

  Next, a toner manufacturing method will be described. The toner of the present invention can be obtained using various methods. For example, reviewing the pulverization process in toner production and making the fine irregularities on the toner surface uniform is effective for obtaining a toner having the cohesion degree defined in the present application. In addition, as described in JP-A No. 2004-295100, a method for increasing the circularity while preventing many release agents from existing on the surface is also effective. However, this invention is not limited to the thing manufactured with this manufacturing method.

  In order to obtain the toner of the present invention, it is preferable that the pulverization step includes a step of performing multistage pulverization near the desired particle size, instead of making the desired particle size all at once. By including such a step, the power of the pulverizer can be used not only as pulverization energy but also as energy for uniforming the unevenness of the toner particle surface. Further, it is preferable to include a step of performing classification simultaneously with spheroidization.

  Hereinafter, the method for producing the toner will be specifically described. First, in the raw material mixing step, as a toner internal additive, at least a binder resin, a release agent, and a colorant are weighed, and if necessary, a predetermined amount of charge control is weighed and mixed. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

Further, the toner raw material mixed as described above is melt-kneaded to disperse the colorant and the like in the resins to obtain a colored resin composition. For melt kneading, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of being capable of continuous production. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd. In general, a twin-screw extruder manufactured by Kay C. K. Co., a co-kneader manufactured by Buss, or the like is used. Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is melt-kneaded, rolled with two rolls, etc., and cooled by water cooling or the like.

Next, in order to obtain toner particles, the colored resin composition cooling material is pulverized. In general, the above-mentioned cooling material is only pulverized to a desired particle size, but in order to obtain the toner of the present invention, in this pulverization step, the fine irregularities of the toner particles are controlled and the degree of circularity is controlled. It is preferable to include the process of improving. In the first coarse pulverization step, the raw material of the toner particles is generally coarsely pulverized to about 1 to 3 mm. In order to obtain the toner of the present invention, a coarsely pulverized product of about 0.3 mm is obtained. It is preferable to repeat the coarse pulverization step until a s. In the coarse pulverization step, a crusher, a hammer mill, a feather mill or the like can be used. Next, using a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nissin Engineering Co., Ltd., a turbo mill manufactured by Turbo Industry, etc., this coarsely pulverized product is slightly larger than a desired toner particle size (for example, about 6 μm). ) Medium pulverize to medium pulverized product. Thereafter, it is further pulverized to a finely pulverized product having a desired toner particle size (for example, about 5 μm) using a turbo mill (RSS rotor / SNNB liner) manufactured by Turbo Industry. Unlike conventional turbo mills, turbo mills with RSS rotor / SNNB liners have a rotor-to-tooth distance of 70% shorter than conventional turbo mills and a tooth height of 70%. Therefore, it seems that the time between the teeth is short, and the residence time between the rotor and the liner is long. The long residence time contributes to uniforming the fine irregularities, and as a result, it is easy to obtain a toner having a cohesion degree as defined in the present application and a uniform circularity distribution. I think that the. In addition, it is considered that making the pulverization process multistage greatly contributes to uniform unevenness of the toner particle surface.
Furthermore, in order to make the unevenness of the surface of the finely pulverized product obtained as described above more uniform, it is also useful to treat with a device that performs classification simultaneously with spheroidization. This apparatus can obtain toner particles having a desired toner particle size while increasing the circularity, and specifically includes a faculty manufactured by Hosokawa Micron. By producing the toner as described above, toner particles that realize the physical properties of the toner of the present invention can be easily obtained.

Mix the toner particles and inorganic fine powder obtained in this way in a predetermined amount, and stir and mix using a high-speed stirrer that gives shearing force to the powder of Henschel mixer, super mixer, etc. as an external additive. Thus, a toner can be obtained. When silica fine powder, titanium oxide fine powder, and alumina fine powder are used in combination as inorganic fine powder, use a high-speed stirrer as an external additive to mix titanium oxide fine powder, alumina fine powder, etc. with low resistance first. Then, it is preferable to further mix silica fine powder.
In this way, after adding and mixing the inorganic fine powder, if necessary, the coarse powder generated during the external addition is removed using a sieving machine such as a wind-type sieve high voltor (manufactured by Shin Tokyo Machinery Co., Ltd.). May be.

FIG. 4 shows an example of an apparatus that can perform classification and spheroidization simultaneously.
The batch type surface reforming apparatus shown in FIG. 4 includes a cylindrical main body casing 30, a top plate 43 installed on the upper portion of the main body casing so as to be openable and closable; a fine powder discharge section 44 having a fine powder discharge casing and a fine powder discharge pipe; Cooling jacket 31 through which cooling water or antifreeze liquid can be passed; as a spheroidizing means, it has a plurality of square disks 33 on the upper surface, which are attached to the central rotating shaft in the main body casing 30 and are fast in a predetermined direction. A dispersion rotor 32 that is a disk-like rotating body that rotates in a straight line; a liner 34 that is fixedly arranged around the dispersion rotor 32 at a constant interval and that has a plurality of grooves on the surface facing the dispersion rotor 32; Classification rotor 35 for continuously removing fine powder and ultrafine powder having a predetermined particle diameter or less in the finely pulverized product; cold air inlet 4 for introducing cold air into the main body casing 30 A charging pipe having a raw material charging port 37 and a raw material supply port 39 formed on the side surface of the main body casing 30 for introducing finely pulverized material (raw material); for discharging processed toner particles out of the main body casing 30; A product discharge pipe having a product discharge port 40 and a product extraction port 42; an openable and closable raw material supply valve 38 installed between the raw material input port 37 and the raw material supply port 39 so that the processing time can be freely adjusted; and A product discharge valve 41 is provided between the product discharge port 40 and the product extraction port 42.

The batch type surface modification apparatus has a cylindrical guide ring 36 as a guide means having an axis perpendicular to the top plate 43 in the main body casing 30. The upper end of the guide ring 36 is provided at a predetermined distance from the top plate, and the guide ring is fixed to the main body casing 30 by a support so as to cover at least a part of the classification rotor 36. The lower end of the guide ring 36 is provided at a predetermined distance from the rectangular disk 33 of the dispersion rotor 32.
In the batch type surface modification apparatus, the space between the classification rotor 35 and the dispersion rotor 32 is divided into a first space 47 outside the guide ring 36 and a second space 48 inside the guide ring 36. Divided by the guide ring 36. The first space 47 is a space for guiding the finely pulverized product and the surface-modified particles to the classification rotor 35, and the second space guides the finely pulverized product and the surface-modified particles to the dispersion rotor. It is a space for. A gap between the plurality of rectangular disks 33 installed on the dispersion rotor 32 and the liner 34 is a surface modification zone 49, and the classification rotor 35 and a peripheral portion of the classification rotor 35 are classification zones 50. .

Next, the image forming method of the present invention will be described.
The image forming method of the present invention includes a charging step for charging an image carrier, a latent image forming step for forming an electrostatic latent image on the image carrier charged in the charging step, and the image carrier formed on the image carrier. The electrostatic latent image is developed using toner to form a toner image, the toner image on the image carrier is transferred to a transfer material via an intermediate transfer member, the toner image is In an image forming method including a fixing process in which a fixing material is pressed and fixed to a transfer material at a fixing nip portion formed between a fixing member and a pressure member, a surface pressure at the fixing nip portion is 5.0 to 11.0 N / m ^2. The toner of the present invention is used as the toner. This surface pressure is lighter than the pressure generally employed, and can effectively bring out the function of the toner of the present invention.
The surface pressure is obtained by dividing the force applied between the fixing member and the pressure member by the nip area calculated by the product of the nip width and the longitudinal length of the roller.

An image forming apparatus using a general cleaning method that can use the toner and developer of the present invention will be described.
FIG. 2 is a schematic cross-sectional view of an image forming apparatus using a normal cleaning method. In FIG. 2, the surface of an image carrier (for example, an electrophotographic photosensitive drum) 28 uniformly charged by a charger 21 as a charging unit is first exposed by a laser exposure unit 22 as a latent image forming unit, An electrostatic latent image is formed on the image carrier 28. Thereafter, the electrostatic latent image on the image carrier 28 is visualized (developed) as a toner image by the developing device 11 as a developing means.
After the toner image is transferred onto a recording paper 27 as a recording medium conveyed by the transfer belt 24 by a transfer electric field by the transfer charger 23, the recording paper 27 is peeled off from the transfer belt 24. The transferred image is pressed and heated by the fixing device 25 to obtain a fixed image.
Further, the residual toner and carrier remaining on the image carrier 28 after the transfer are removed by a cleaner (cleaning device) 26 to prepare for the next image formation. The cleaner 26 has a blade that abuts over an image forming area and a non-image forming area on the image carrier 28, and forms a non-image on the image carrier 28 from a developer carrier (for example, a developing sleeve). The carrier that has overcome the magnetic force and is electrostatically transferred to the region is also rubbed and removed.

In addition, the toner of the present invention can be applied to an image forming method including a system that collects untransferred toner in the development process, and can eliminate charging defects caused by voids that are particularly likely to occur in the system. This is more preferable.
A system for collecting untransferred toner simultaneously with development is shown in FIG. In FIG. 3, an electrophotographic photoreceptor 1 as an image carrier rotates in the b direction. The photosensitive member 1 is charged by a charging device 2 as a charging unit, and then a laser beam L is projected onto the charged surface of the photosensitive member 1 by an exposure device 3 as an electrostatic latent image forming unit to form an electrostatic latent image. Is done. Next, the electrostatic latent image is visualized as a toner image by the developing device 4 as developing means, and is transferred to the transfer material P by the transfer device 5 as transfer means. In this transfer unit, the untransferred toner remaining on the surface of the photosensitive member without being transferred passes through the above-described charging unit and electrostatic latent image forming unit, and is again used for development or collected by the developing device.
Further, as shown in FIG. 3, it is preferable to provide a leveling means 6 to which a bias applying means is connected. By passing the leveling means 6, the uniformity of the charging polarity of the transfer residual toner can be improved, and the recovery rate of the transfer residual toner can be improved.

  A method for measuring various physical properties will be described.

1) Measurement of aggregation degree of toner As for the aggregation degree Y2 at the time of non-compression, about 1 g of toner is weighed and left in a normal temperature and normal humidity environment (23 ° C./60% RH) for 12 hours or more, and a powder tester (manufactured by Hosokawa Micron). Is used, and the ratio of the toner remaining on each mesh is measured and obtained by the following formula (1). The mesh used for the measurement has openings of 250 μm, 150 μm, and 75 μm from the top. When measuring the degree of aggregation during non-compression, the toner sample is weighed so as not to apply pressure as much as possible.
Aggregation degree = 250 μm residual toner ratio (mass%) + 150 μm residual toner ratio (mass%) × 0.6 + 75 μm residual toner ratio (mass%) × 0.2 (1)
As for the degree of aggregation Y1 at the time of compression, about 1 g of toner is weighed and left in a normal temperature and humidity environment (23 ° C./60% RH) for 12 hours or more, and then the toner is put flat on a flat plate molding machine having a diameter of 25 mm. . A flat lid is put on this and a load of 200 kPa is applied for 1 minute, then the load is removed, and the toner is transferred to the medicine-wrapping paper as much as possible without breaking, and the degree of aggregation is measured using a powder tester as described above.

2) Maximum endothermic peak measurement of toner Temperature curve: Temperature increase I (30 ° C. to 200 ° C., temperature increase rate 10 ° C./min)
Temperature drop I (200 ° C-30 ° C, temperature drop rate 10 ° C / min)
Temperature increase II (30 ° C. to 200 ° C., temperature increase rate 10 ° C./min)
The maximum endothermic peak of the toner is measured according to ASTM D3418-82 using a differential scanning calorimeter (DSC measuring device), DSC-7 (manufactured by PerkinElmer) or DSC2920 (manufactured by TA Instruments Japan). In this example, measurement was performed using DSC-7.
A measurement sample of 5 to 20 mg, preferably 10 mg, is accurately weighed and placed in an aluminum pan. An empty aluminum pan is used as a reference. Measurement is performed in a normal temperature and humidity environment (23 ° C./60% RH) at a temperature increase rate of 10 ° C./min within a measurement range of 30 to 200 ° C. The maximum endothermic peak of the toner has the highest peak height from the baseline in the temperature range II in the temperature range equal to or higher than Tg of the measurement sample. When the endothermic peak of Tg overlaps with other endothermic peaks, and the maximum endothermic peak is difficult to distinguish, the endothermic peak including the overlapping endothermic peaks is the one with the highest peak height from the baseline as the maximum endothermic peak. To do.

3) Molecular weight measurement of release agent Apparatus: GPC-150C (Waters)
Column: GMH-HT 30 cm, 2 stations (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1 mass% ionol added)
Flow velocity: 1.0ml / min
Sample: 0.4 ml injection of 0.15% by weight of release agent Measured under the above conditions, and a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used for calculating the molecular weight of the release agent. As a standard polystyrene sample for preparing a calibration curve, for example, about 10 ² to 10 ⁷ is used, and it is appropriate to use at least about 10 polystyrene standard samples. For example, TSK standard polystyrene manufactured by Tosoh Corporation (F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F -1, A-5000, A-2500, A-1000, A-500) can be used. Furthermore, the molecular weight of the release agent is calculated by converting to polyethylene based on a conversion formula derived from the Mark-Houwink viscosity formula.

4) Measurement of average circularity of toner The circularity of toner is measured using a flow type particle image measuring device “FPIA-2100 type” (manufactured by Sysmex Corporation), and is calculated using the following equation.

  Here, “particle projection area” is the area of the binarized particle image, and “peripheral length of the particle projection image” is defined as the length of the contour line obtained by connecting the edge points of the particle image. . In the measurement, a particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm) is used.

  In the present invention, the degree of circularity is an index indicating the degree of unevenness of particles, and is 1.00 when the particles are perfectly spherical. The more complicated the surface shape, the smaller the degree of circularity.

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

  In the “FPIA-2100” used for measuring the average circularity of the toner of the present invention, after calculating the circularity of each particle, the circularity of the particles is determined by the obtained circularity in calculating the average circularity. Class obtained by equally dividing 0.40 to 1.00 every 0.01 (0.40 or more and less than 0.41, 0.41 or more and less than 0.42, ..., 0.98 or more and less than 0.99, 0 .99 or more and less than 1.00 and 1.00). The average circularity is calculated using the center value of the dividing points of each class and the number of particles divided into each class.

As a specific method for measuring the average circularity using FPIA-2100, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably dodecyl, is used as a dispersant therein. After an appropriate amount of sodium benzenesulfonate is added, 0.02 g of toner is further added and dispersed uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of the said dispersion liquid may not become 40 degreeC or more.
Before starting the measurement, standard latex particles (for example, 520 manufactured by Duke Scientific)
0A is diluted with ion-exchanged water). In order to suppress variation in circularity, the installation environment of the apparatus is controlled to 23 ° C. ± 0.5 ° C. so that the in-machine temperature of the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Further, automatic focus adjustment is performed every 2 hours using standard latex particles (for example, Duke Scientific 5200A diluted with ion-exchanged water). In this embodiment, a flow type particle image analyzer which has been issued a calibration certificate issued by Sysmex Corporation, which has been calibrated by Sysmex Corporation, has an analysis particle diameter of 2.00 μm in equivalent circle diameter. The measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that it was limited to 200.00 μm or less.
At the time of measurement, the concentration of the dispersion is adjusted so that the concentration of toner and toner particles is 3000 to 10,000 / μl, and the circularity and equivalent circle diameter are measured for 1000 or more particles. After the measurement, using this data, data having an equivalent circle diameter of less than 2.00 μm is cut to determine the average circularity of the toner.
The equivalent circle diameter can be calculated based on the following formula.

  The average circularity in each equivalent circle diameter range of the equivalent circle diameter of 2.00 μm to less than 3.00 μm, 3.00 μm to less than 6.92 μm, 6.92 μm to less than 12.66 μm is the average circularity of the particles in each equivalent circle diameter range. Based on the circularity data, the above formula is used.

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

5) Average Valley Depth Measurement on Toner Particle Surface In the present invention, the maximum valley depth Rv (nm) on the toner particle surface is measured using a scanning probe microscope. Below, the example of a measuring method is shown.
Probe station: SPI3800N (manufactured by Seiko Instruments Inc.)
Measuring unit: SPA400
Measurement mode: DFM (resonance mode) shape image Cantilever: SI-DF40P
Resolution: Number of X data 256
Number of Y data 128

In the present invention, an area of 2 μm square on the toner particle surface is measured. The area to be measured is a 2 μm square area at the center of the toner particle surface measured with a scanning probe microscope. The toner particles to be measured are randomly selected (D4 ± 10%) substantially equal to the weight average particle diameter (D4) measured by the Coulter counter method, and the maximum valley depth Rv on the toner particle surface is measured. . The measured data is secondarily corrected. 20 or more different toner particles are measured, and the obtained data Rv is averaged to obtain an average valley depth Rvm of the toner particle surface.

In a toner in which an external additive is externally added to the toner particles, it is necessary to remove the external additive when the Rv on the surface of the toner particles is measured using a scanning probe microscope. The method is mentioned.
(1) Put 45 mg of toner into a sample bottle and add 10 ml of methanol.
(2) Disperse the sample for 1 minute with an ultrasonic cleaner to separate the external additive.
(3) Separating toner particles and external additives by suction filtration (10 μm membrane filter). In the case of a toner containing a magnetic material, the toner particles may be fixed by applying a magnet to the bottom of the sample bottle to separate only the supernatant.
(4) The above (2) and (3) are repeated three times in total, and the obtained particles are sufficiently dried at room temperature using a vacuum dryer.

  The toner particles from which the external additive has been removed are observed with a scanning electron microscope, and after confirming that the external additive has disappeared, the average valley depth of the toner particles is measured with a scanning probe microscope. When the external additive has not been sufficiently removed, the surface of the toner particle is observed with a scanning probe microscope after repeating (2) and (3) until the external additive is sufficiently removed. As another method of removing the external additive in place of (2) and (3), there is a method of dissolving the external additive with an alkali. As the alkali, an aqueous sodium hydroxide solution is preferred.

6) Measurement of molecular weight distribution of toner and binder resin by GPC The molecular weight distribution in the resin component of toner and binder resin is as follows: THF soluble component obtained by dissolving toner or binder resin in THF solvent And measured by GPC.

  That is, the toner is put in THF, left for several hours, and then sufficiently shaken to mix well with THF (until the sample is no longer united), and then left to stand for 12 hours or more. At this time, the standing time in THF is set to be 24 hours or longer. Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, a Mysori Disc H-25-5 manufactured by Tosoh Corporation, an Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd., etc.) can be used. A sample of GPC is used. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

The GPC measurement of the sample prepared by the above method was performed by stabilizing the column in a heat chamber at 40 ° C., and flowing tetrahydrofuran (THF) as a solvent at a flow rate of 1 ml / min. Is measured by injecting about 50 to 200 μl. 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 (retention time). Examples of standard polystyrene samples for preparing a calibration curve include those manufactured by Tosoh Corporation or Pressure Chemical Co. The molecular weights manufactured are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8 It is suitable to use a standard polystyrene sample of at least about 10 points, using .6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ . An RI (refractive index) detector is used as the detector.

As a column, in order to accurately measure a molecular weight region of 1 × 10 ³ to 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns, for example, sh made by Showa Denko K.K.
A combination of Odex GPC KF-801, 802, 803, 804, 805, 806, and 807, and a combination of μ-styrel 500, 10 ³ , 10 ⁴ , and 10 ⁵ manufactured by Waters may be mentioned.

7) Measurement of toner particle size distribution and weight average particle size (D4) In the present invention, the average particle size and particle size distribution of the toner are measured using a Coulter Counter TA-II type (manufactured by Coulter Co.). It is also possible to use Coulter Co.). As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) can be used as the electrolyte. As a measuring method, 0.1 to 5 ml of a surfactant, preferably sodium dodecylbenzenesulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number of toner particles of 2.00 μm or more are measured by using the 100 μm aperture as the aperture by the measuring device. Distribution and number distribution are calculated. Then, a weight average particle diameter (D4) (the median value of each channel is used as a representative value for each channel) is obtained.

  As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32.00-40.30 μm are used.

8) Measurement of softening point (Tm) of resin In JIS K 7210, it refers to that measured by an elevated flow tester. A specific measurement method is shown below. While a 1 cm ³ sample was heated at a heating rate of 6 ° C./min using an elevated flow tester (manufactured by Shimadzu Corporation), a load of 1960 N / m ² (20 kg / cm ² ) was applied by a plunger, A nozzle with a length of 1 mm is pushed out, thereby drawing a plunger descending amount (flow value) -temperature curve, where the height of the S-shaped curve is h, the temperature corresponding to h / 2 (resin The temperature at which half flows out) is defined as the softening point (Tm) of the resin.

9) Measurement of number average particle diameter of inorganic fine powder The number average particle diameter of inorganic fine powder is measured using a scanning electron microscope (S-4700, manufactured by Hitachi, Ltd.). The photographing magnification is 100,000 times, and further, the photographed photograph is enlarged twice, and then 200 to 500 samples of inorganic fine powder are randomly extracted from this photograph image. Then, the maximum particle size is the major axis, the minimum particle size is the minor axis, and the number average particle size is determined based on the major axis. When measuring the number average particle size of the inorganic fine powder on the toner particle surface, elemental analysis is performed in advance using an energy dispersive X-ray analyzer (manufactured by EDAX) when extracting the sample. Extraction is performed after grasping the shape of various types of particles.

10) Measurement of transmittance in 45% by volume methanol aqueous solution (i) Preparation of toner dispersion An aqueous solution having a volume mixing ratio of methanol: water of 45:55 is prepared. 10 ml of this aqueous solution is placed in a 30 ml sample bottle (Nippon Denka Glass: SV-30), and 20 mg of toner is impregnated on the liquid surface to cover the bottle. Then, it is made to shake for 5 seconds at 2.5S- ¹ with a Yayoi type shaker (model: YS-LD). At this time, the angle of shaking is such that the shaking column moves 15 degrees forward and 20 degrees backward, assuming that the vertical (vertical) of the shaker is 0 degree. The sample bottle is fixed to a fixing holder (with the sample bottle lid fixed on the extension at the center of the column) attached to the tip of the column. After removing the sample bottle, the dispersion after 30 seconds is used as a dispersion for measurement.
(Ii) Transmittance measurement The dispersion obtained in (i) is put in a 1 cm square quartz cell, and the transmittance (wavelength 600 nm) of the dispersion after 10 minutes using a spectrophotometer MPS2000 (manufactured by Shimadzu Corporation) ( %).
Transmittance (%) = (I / I ₀ ) × 100 (I: transmitted light beam, I ₀ : incident light beam)

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

(Example of hybrid resin production)
As monomers for forming a vinyl copolymer unit, styrene 2.0 mol, 2-ethylhexyl acrylate 0.21 mol, fumaric acid 0.14 mol, α-methylstyrene dimer 0.03 mol, dicumyl peroxide 0.05 mol Was placed in a dropping funnel. Moreover, as a monomer which forms a polyester resin unit, 7.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (3.0 mol), terephthalic acid (3.0 mol), trimellitic anhydride (1.9 mol), fumaric acid (5.0 mol) and dibutyltin oxide (0.2 g) were placed in a glass 4-liter four-necked flask. . A thermometer, a stir bar, a condenser and a nitrogen introducing tube were attached to the flask and placed in a mantle heater. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually increased while stirring, and while stirring at a temperature of 145 ° C., the vinyl resin monomer and the polymerization initiator were added from the previous dropping funnel over 4 hours. And dripped. Next, the temperature was raised to 200 ° C. and reacted for 4 hours to obtain a hybrid resin (Tm = 110 ° C.). The results of molecular weight measurement by GPC are shown in Table 1.

(Example of polyester resin production)
3.6 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.6 mol of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 1.7 mol of terephthalic acid, 0.1 mol of trimellitic anhydride, 2.4 mol of fumaric acid, and 0.12 g of dibutyltin oxide were placed in a 4-liter four-necked flask made of glass. A thermometer, a stir bar, a condenser and a nitrogen introducing tube were attached to the flask and placed in a mantle heater. Under a nitrogen atmosphere, the mixture was reacted at 215 ° C. for 5 hours to obtain a polyester resin (Tm = 95 ° C.). The results of molecular weight measurement by GPC are shown in Table 1.

<Example 1>
Toner 1 was produced as shown below.
-60 mass parts of said hybrid resin * 40 mass parts of cyan pigments (PigmentBlue 15: 3) It melt-kneaded with the kneader mixer by said prescription, and produced the cyan masterbatch.

-91 parts by mass of the above hybrid resin-Purified normal paraffin (maximum endothermic peak temperature 70 ° C, Mw = 450, Mn = 320)
5 parts by mass · Cyan masterbatch (colored amount 40% by mass) 15 parts by mass

Preliminarily mixed with a Henschel mixer with the above formulation, melt-kneaded so that the kneaded material temperature becomes 150 ° C. with a twin-screw extruder kneader, coarsely crushed to about 1 to 2 mm using a hammer mill after cooling, The hammer shape was changed again, and a coarsely pulverized product of about 0.3 mm was produced using a hammer mill with a finer mesh. Further, a medium pulverized product of about 11 μm was made using a turbo mill (RS rotor / SNB liner) manufactured by Turbo Industry. Further, a medium pulverized product of about 6 μm was made using a turbo mill (RSS rotor / SNNB liner) manufactured by Turbo Industry. The treatment was again performed under the same conditions (RSS rotor / SNNB liner) to obtain a finely pulverized product of about 5 μm. The pulverization with a turbo mill was performed at a rotational speed of 7400 rpm while introducing -20 ° C. cold air into the apparatus. Next, using the Faculty of Hosokawa Micron Co., Ltd., which has been changed to 1.5 times the height of the disk installed on the surface of the dispersion rotor, spheronization is performed at the same time as classification to reduce the particle size to 5.3 μm. (Toner particles) were obtained.

First, 0.9 part by mass of anatase-type titanium oxide fine powder (BET specific surface area = 80 m ² / g, treated with 12% by mass of isobutyltrimethoxysilane) is added to 100 parts by mass of cyan particles 1 (toner particles) using a Henschel mixer. Externally added, oil-treated silica (inorganic fine powder B; number-average particle diameter 12 nm, BET specific surface area 95 m ² / g, dimethyl silicone oil 15% by weight treatment) 1.2 parts by mass, oil-treated silica (inorganic fine powder A A number average particle size of 30 nm, a BET specific surface area of 28 m ² / g, dimethyl silicone oil 5 mass% treatment) 0.3 parts by mass was externally added using a Henschel mixer to prepare toner 1. The weight average diameter (D4) of Toner 1 was 5.3 μm. The physical properties of Toner 1 are shown in Tables 2 and 3.

  Further, toner 1 and magnetic ferrite carrier particles (volume average particle size 40 μm: Mn—Mg ferrite) surface-coated with a silicone resin are mixed so that the toner concentration becomes 8.0 mass%, and two-component development is performed. Agent 1 was obtained.

Using this two-component developer 1, 1000 sheets using LBP-5900 (manufactured by Canon Inc.) and using an original document with an image area ratio of 5% in a single color mode under a normal temperature and low humidity environment (23 ° C./5% RH). The printing durability test was evaluated. Note that LBP-5900 is an apparatus having an intermediate transfer member, and fixing was performed with the surface pressure at the fixing nip portion being 9.5 N / m ² .
In the image formation using the two-component developer 1, a cyan image that faithfully reproduces the original without fogging and without fogging after 1000 sheets of durability was obtained. Further, the fixing property and blocking property were also good, and the evaluation of void in a high temperature and high humidity environment (30 ° C./80% RH) was also good. The evaluation criteria for each evaluation item are shown below, and the evaluation results are shown in Table 4.

<Fog measurement>
Using an LBP-5900 (manufactured by Canon Inc.), a 1000-sheet printing test is evaluated using an original document having an image area ratio of 5% in a single color mode under a normal temperature and low humidity environment (23 ° C./5% RH). In the durability test, the method for measuring fog is as follows. First, in the case of a cyan image, the average reflectance Dr (%) of plain paper before image printing is measured with a reflectometer (“REFECTOMETER MODEL TC-6DS” manufactured by Tokyo Denshoku Co., Ltd.) equipped with an amber filter. . On the other hand, a solid white image is drawn on plain paper, and then the reflectance Ds (%) of the solid white image is measured. Using these measured values, fog (Fog (%)) is obtained by the following formula.
Fog (%) = Dr (%) − Ds (%)
A: Less than 0.7% B: 0.7 or more, less than 1.2% C: 1.2 or more, less than 1.5% D: 1.5 or more, less than 2.0% E: 2.0% or more

<Measurement of toner fixable area>
A fixing test was conducted using a fixing device of a fixing device of LBP-5900 (manufactured by Canon Inc.) and a fixing unit capable of manually operating the fixing temperature. For the image, LBP-5900 was used to adjust the development contrast so that the amount of toner on paper was 1.2 mg / cm ² in a single color mode in a normal temperature and humidity environment (23 ° C./60% RH), and an unfixed image Create An image is formed on A4 (recommended paper, EW-500, manufactured by Canon Inc.) at an image area ratio of 25%. In a normal temperature and normal humidity environment (23 ° C./60% RH), the temperature is increased from 140 ° C. in increments of 5 ° C. up to 215 ° C., and the temperature range in which no offset or wrapping occurs is defined as the fixable region.

<Toner blocking evaluation>
About 10 g of toner was put in a 100 ml polycup and allowed to stand at 50 ° C. for 3 days, and then visually evaluated. The evaluation criteria are as follows.
A: Aggregates are not seen.
B: Aggregates are slightly seen but easily collapse.
C: Aggregates are seen but easily collapse.
D: Agglomerates are seen, but collapse if shaken.
E: Aggregates can be grasped and do not collapse easily.

<Toner dropout evaluation>
Using LBP-5900 (manufactured by Canon Inc.), the development contrast is adjusted so that the toner loading on the paper is 0.6 mg / cm ² in a single color mode under a high temperature and high humidity environment (30 ° C./80% RH). An image is formed so that there are fine lines in both the vertical and horizontal directions, two 2, 4, 6, 8, and 10 dot lines are printed, and the non-latent image width between each line is about 1 mm. The result of observation with a magnifying glass was used as an evaluation of hollowness.
A: In the 2-dot line, almost no voids can be confirmed even by magnified observation.
B: In the 2-dot line, some of the voids are confirmed by magnified observation and cannot be confirmed visually.
C: A void is visually confirmed in a 2-dot line, and a void is not visually confirmed in a 4-dot line.
D: A void can be visually confirmed in a 4-dot line, and a void cannot be visually confirmed in a 6-dot line.
E: In the 6-dot line, the voids can be confirmed visually.

<Evaluation of toner scattering>
Using LBP-5900 (manufactured by Canon Inc.), scattering in an image of a horizontal line pattern in which 4-dot horizontal lines were printed every 176 dot spaces in a single color mode under a normal temperature and low humidity environment (23 ° C./5%) was evaluated. . The magnified observation was performed using a 20 × magnifier.
A: Almost no image splattering is observed even by magnified observation.
B: Slight image splattering can be seen even in magnified observation.
C: Characters blur slightly due to scattering.
D: Unevenness occurs in the line thickness due to scattering.
E: Some characters are crushed due to scattering.

<Example 2>
In Example 1, the hybrid resin was changed to the polyester resin, and purified paraffin (maximum endothermic peak temperature 70 ° C., Mw = 450, Mn = 320) was changed to polyethylene wax (maximum endothermic peak temperature 99 ° C., as shown in Table 2. Cyan particles 2 (toner particles) were obtained in the same manner as in Example 1 except that Mw = 770 and Mn = 620). Thereafter, external addition was performed in the same manner as in Example 1 to obtain a toner 2 having physical properties shown in Tables 2 and 3. Various evaluations were made in the same manner as in Example 1. As shown in Table 4, although the fixing property was slightly inferior, the results were good.

<Example 3>
In Example 2, as shown in Table 2, polyethylene wax (maximum endothermic peak temperature 99 ° C., Mw = 770, Mn = 620) was changed to polyethylene wax (maximum endothermic peak temperature 126 ° C., Mw = 2560, Mn = 1920). Then, cyan particles 3 (toner particles) were obtained in the same manner as in Example 2 except that the temperature of the cold air introduced into the turbo mill was changed to 0 ° C. Thereafter, external addition was performed in the same manner as in Example 1 to obtain a toner 3 having physical properties shown in Tables 2 and 3. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, although it was inferior in scattering and fixability, it was at a level where there was no practical problem.

<Example 4>
In Example 2, as shown in Table 2, polyethylene wax (maximum endothermic peak temperature 99 ° C., Mw = 770, Mn = 620) was stearic stearate (maximum endothermic peak temperature 64 ° C., Mw = 520, Mn = 400). The cyan particles 4 (toner particles) were obtained in the same manner as in Example 2 except that the rotational speed of the rotor of the turbo mill was lowered to 6400 rpm and the rotational speed of the dispersed rotor of the Faculty was further reduced. Thereafter, external addition was performed in the same manner as in Example 1 to obtain a toner 4 having physical properties shown in Tables 2 and 3. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, although it was inferior to hollowing out, blocking, and fogging, it was at a level causing no practical problems.

<Comparative Example 1>
In Example 2, the polyethylene wax (maximum endothermic peak temperature 99 ° C., Mw = 770, Mn = 620) was changed to polypropylene wax (maximum endothermic peak temperature 147 ° C., Mw = 8900, Mn = 1000) as shown in Table 2. A finely pulverized product was made in the same manner except that. Thereafter, the finely pulverized product was subjected to heat spheronization treatment with hot air at 300 ° C. using Meteole Inbo (manufactured by Nippon Pneumatic Co., Ltd.) and classified using an elbow jet classifier to obtain cyan particles 5 (toner particles). Thereafter, external addition was performed in the same manner as in Example 1 to obtain a toner 5 having physical properties shown in Tables 2 and 3. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, the results were scattered and the fixing property was inferior.

<Comparative example 2>
In the formulation of Example 2, as shown in Table 2, polyethylene wax (maximum endothermic peak temperature 99 ° C., Mw = 770, Mn = 620) was added palmitic acid palmitate (maximum endothermic peak temperature 53 ° C., Mw = 440, Mn = 290). ), And melt-kneaded in the same manner as in Example 2 and cooled to obtain a melt-kneaded product. Thereafter, the molten kneaded material is roughly pulverized to about 1 to 2 mm using a hammer mill, and then directly using a turbo mill (RS rotor / SNB liner),
A finely pulverized product of about m was produced. Subsequently, classification was performed using an elbow jet classifier to obtain cyan particles 6 (toner particles). Thereafter, external addition was performed in the same manner as in the toner 1 to obtain a toner 6 having physical properties shown in Tables 2 and 3. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, the results were inferior to hollowing out, blocking, and fogging.

<Comparative Example 3>
After melt kneading using the formulation of Example 2 and cooling the resulting kneaded product, it is roughly crushed to about 1 to 2 mm using a hammer mill, and then using a fine pulverizer using an air jet method. The powder was finely pulverized to about 5 μm at a stretch to obtain a finely pulverized product. Subsequently, the particles were classified using a Faculty manufactured by Hosokawa Micron Corporation to obtain cyan particles 7 (toner particles). Thereafter, external addition was performed in the same manner as in Example 1 to obtain a toner 7 having physical properties shown in Tables 2 and 3. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, the results were inferior to the hollows.

<Comparative example 4>
-Preparation of resin particle dispersion 1 Styrene 370 g
30g of n-butyl acrylate
Acrylic acid 6g
24g dodecanethiol
Carbon tetrabromide 4g
A mixed solution in which the above was mixed and dissolved was obtained. Non-ionic surfactant (Nonipol 400, manufactured by Sanyo Kasei Co., Ltd.) 6 g and anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 10 g were added to 550 g of ion-exchanged water. The dissolved material was dispersed and emulsified in a flask, and 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added while slowly mixing for 10 minutes. The mixture was heated in an oil bath until the content reached 70 ° C. with stirring, and emulsion polymerization was continued for 5 hours, thus the average particle diameter was 150 nm, the glass transition point was 62 ° C., and the weight average molecular weight (Mw) was 12. Resin particle dispersion 1 was prepared by dispersing resin particles having a molecular weight of 1,000.

-Preparation of resin particle dispersion 2 280 g of styrene
120g of n-butyl acrylate
Acrylic acid 8g
A mixed solution in which the above was mixed and dissolved was obtained. Non-ionic surfactant (Nonipol 400, manufactured by Sanyo Kasei Co., Ltd.) 6 g and anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 12 g were added to 550 g of ion-exchanged water. The dissolved product was dispersed and emulsified in a flask, and 50 g of ion-exchanged water in which 3 g of ammonium persulfate was dissolved was added while slowly mixing for 10 minutes. The mixture was heated in an oil bath until the contents reached 70 ° C. while stirring, and emulsion polymerization was continued for 5 hours, thus the average particle size was 110 nm, the glass transition point was 55 ° C., and the weight average molecular weight (Mw) was 550. Resin particle dispersion 2 was prepared by dispersing resin particles of 1,000.

-Preparation of release agent particle dispersion 1 Polyethylene wax (melting point 89 ° C.) 50 g
Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5g
200g of ion exchange water
The above was heated to 95 ° C. and dispersed using a homogenizer or the like, then dispersed with a pressure discharge type homogenizer, and a release agent particle dispersion 1 in which a release agent having an average particle size of 570 nm was dispersed was obtained. Prepared.

-Preparation of colorant particle dispersion 1 C.I. I. Pigment Blue 15: 3 20g
Anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2g
Ion exchange water 78g
The above was mixed and dispersed for 10 minutes at an oscillation frequency of 26 kHz using an ultrasonic cleaner to prepare a colorant particle dispersion (anionic) 1.

-Preparation of liquid mixture Resin particle dispersion 1 180 g
Resin particle dispersion 2 80g
Colorant particle dispersion 1 30 g
Release agent particle dispersion 1 50 g
The above was mixed in a round stainless steel flask using a homogenizer or the like and dispersed to prepare a mixed solution.

-Formation of agglomerated particles 1.2 g of a cationic surfactant (Sanisol B50, manufactured by Kao Corporation) as an aggregating agent is added to the above mixed solution, and the temperature in the flask is increased to 50 ° C while stirring in the heating oil bath. Heated. After maintaining at 50 ° C. for 1 hour, observation with an optical microscope confirmed that aggregated particles having a weight average particle diameter of about 4.8 μm were formed.

・ Fusion Then, after adding 3 g of anionic surfactant (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), the stainless steel flask was sealed, and stirring was continued using a magnetic seal up to 105 ° C. Heated and held for 3 hours. After cooling, the reaction product was filtered, sufficiently washed with ion-exchanged water, and dried to obtain cyan particles 8 (toner particles).
Thereafter, external addition was performed in the same manner as in Example 1 to obtain a toner 8 having physical properties shown in Tables 2 and 3. The obtained toner 8 had a weight average particle size of 5.5 μm and a peak molecular weight (Mp) determined by GPC of THF-soluble content of 16,500. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, the results were inferior with respect to the voids.

<Comparative Example 5>
In Comparative Example 1, a toner 9 having physical properties shown in Tables 2 and 3 was obtained in the same manner as in the toner 5 except that the thermal spheronization treatment conditions were changed so as to be treated with hot air at 250 ° C. When various evaluations were made in the same manner as in Example 1, as shown in Table 4, the fixing property was inferior.

It is a figure which shows the aggregation degree at the time of compression of the toner of this invention, and the toner of a comparative example at the time of non-compression. FIG. 2 is a schematic cross-sectional view of an image forming apparatus using a cleaning method. FIG. 2 is a schematic cross-sectional view of an image forming apparatus having a development and cleaning process. It is a schematic sectional drawing of an example of a surface modification apparatus.

Claims (4)

Toner particles containing at least a binder resin, a release agent, a colorant, and a toner containing at least an inorganic fine powder,
(I) The toner has a degree of aggregation Y1 during compression (200 kPa) and a degree of aggregation Y2 during non-compression of 15 ≦ Y1 ≦ 35 and 7 ≦ Y2 ≦ 15.
(Ii) The toner has a maximum endothermic peak in a temperature range of 30 to 200 ° C. in an endothermic curve measured by a differential scanning calorimeter (DSC), and the peak temperature Tsc (° C.) of the maximum endothermic peak is A toner, wherein 60 ≦ Tsc ≦ 130. The toner has a weight average particle diameter (D4) of 3.0 μm to 7.0 μm,
The average circularity of a toner having an equivalent circle diameter of 2.00 μm or more is R, the equivalent circle diameter of each circle having an equivalent circle diameter of 2.00 μm or more and less than 3.00 μm, 3.00 μm or more and less than 6.92 μm, or 6.92 μm or more and less than 12.66 μm. When the average circularity of the toner in the range is r (a), r (b), and r (c), the relationship between R, r (a), r (b), and r (c) The toner according to claim 1, wherein the toner satisfies Formula (4) to Formula (4).
0.940 ≦ R ≦ 0.970 Formula (1)
R−0.015 ≦ r (a) ≦ R + 0.015 Formula (2)
R−0.015 ≦ r (b) ≦ R + 0.015 Formula (3)
R−0.015 ≦ r (c) ≦ R + 0.015 Formula (4)   The inorganic fine powder contains at least an inorganic fine powder (A) having a number average particle size of 20 nm or more and less than 300 nm, and an inorganic fine powder (B) having a number average particle size of 5 nm or more and less than 20 nm, The toner according to claim 1 or 2, wherein at least one of the inorganic fine powder (A) and the inorganic fine powder (B) is surface-treated with a silicone oil. A charging step for charging the image carrier, a latent image forming step for forming an electrostatic latent image on the image carrier charged in the charging step, an electrostatic latent image formed on the image carrier with toner Development process for forming a toner image using the toner image, a transfer process for transferring the toner image on the image carrier to a transfer material via an intermediate transfer member, and pressing the toner image on the transfer material at a fixing nip portion. An image forming method having a fixing step of fixing the image,
The surface pressure at the fixing nip is 5.0 to 11.0 N / m ² ;
An image forming method, wherein the toner is the toner according to claim 1.

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