JPH07199520A - Electrophotographic developer - Google Patents

Abstract

PURPOSE:To obtain stable image quality having a high image density over a long period of time without having fogging of non-image parts by mixedly using at least two kinds of toner particle groups which vary in average grain sizes and vary in the grain size of at least one kind of the external additives to be externally added to the respective toner groups. CONSTITUTION:At least two kinds of the toner particle groups which vary in the average grain sizes and vary in the grain size of at least one kind of the external additives to be externally added to the respective toner groups are mixed. Namely, the classified toner group C having the average grain size exhibiting, for example, an average grain size distribution of about 7mum is again classified to A having the average grain size exhibiting a grain size distribution of about 5mum and B having the average grain size exhibiting a grain size distribution of about 8mum. The external additives, such as a flow property improving agent, lubricating agent, polishing agent, conductivity imparting agent, fixing assistant, are added at need to the respective toner groups A, B and these toner groups are mixed and agitated. At this time, the grain size of at least one kind of the external additives to be externally added to the toner groups A is changed from the grain size of the group B. The mixed and agitated toner groups A, B are charged by the adequate amt. each and thereafter the toners are mixed and agitated again to complete the toners.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer (hereinafter referred to as toner) used for developing an electric latent image or a magnetic latent image in electrophotography or electrostatic printing.

[0002]

2. Description of the Related Art Toners for visualizing electrical and magnetic latent images are used in various processes for forming and recording images. As an electrophotographic method which is one of such image forming processes, for example, US Pat. No. 2,297,691 is used.
A large number of methods are known as recorded in the specification and the like.

In this electrophotographic method, generally,
A photoconductive substance is used to form an electrical latent image on the photoconductor by various means, and then this latent image is developed with toner, and this toner image is printed on a recording material such as paper, if necessary. After transfer, the toner image is fixed on the recording material or the like by using heat, pressure, solvent vapor or the like to obtain a copy. Further, when there is a step of transferring the toner image, a step of removing the toner remaining on the photoconductor is usually provided.

Conventionally, as a developer used in a dry developing device, there are: 1-component magnetic developer containing magnetic powder in toner 2: 1-component non-magnetic developer containing no magnetic powder in toner 3: magnetic There is a two-component developer in which a toner containing no powder is mixed with a magnetic carrier in a fixed ratio 4: a two-component developer in which a toner containing a magnetic powder is mixed with a magnetic carrier in a fixed ratio, and the like. The method also includes, for example, the magnetic brush method described in US Pat. No. 2,874,063,
No. 2,618,552, the cascade developing method, No. 2,221,776, the powder cloud method, and No. 3,909,258, the conductive magnetism. Method using toner and JP-B-41-9
Methods and the like using various insulating magnetic toners described in Japanese Patent No. 475, etc. have been proposed and implemented. The toner applied to these developing methods is generally a toner having a desired particle diameter by uniformly dispersing a coloring agent composed of a dye / pigment in a thermoplastic resin, followed by pulverization and classification. Manufactured.

[0005]

However, according to this manufacturing method (crushing method), a considerably excellent toner can be manufactured, but there is a certain limitation, that is, the selection range of the toner material is limited. There is. For example, the resin colorant dispersion must be sufficiently brittle to be finely pulverized in an economically available manufacturing apparatus.

For this reason, the resin colorant dispersion has to be sufficiently brittle, and when the resin colorant dispersion is actually pulverized at a high speed, it is easy to form a particle group having a wide particle size range. Particularly, excessively finely pulverized particles are contained in a relatively large proportion in the particles, which causes a problem of broadening of so-called particle size distribution. Such a highly brittle material is more susceptible to fine pulverization or pulverization when actually used as a product for development in a copying machine or the like.

On the other hand, in order to overcome the problems of the toner by the pulverization method, a method for producing the toner by the suspension polymerization method and the like have been proposed in Japanese Patent Publication No. 36-10231. In this suspension polymerization method, a polymerizable monomer and a colorant, and if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition. After that, this monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer by using a suitable stirrer, and a polymerization reaction is performed at the same time to obtain a desired particle size. It is said that it is possible to obtain toner particles having a particle size. However, when actually manufacturing a toner for a copying machine, the broadening of the particle size distribution was suppressed as compared with the pulverization method, but it was still at a practical level. Turned out not.

Similarly, other polymerization methods used in the production of toner include emulsion polymerization, precipitation polymerization, dispersion polymerization, soap-free emulsion polymerization and seed polymerization, and any of these methods broadens the toner particle size distribution. However, there are some improvements. However, since the toner shapes produced by the respective polymerization methods are spherical fine particles, when the above-described toner image transfer step is included, the toner remaining on the photoconductor (eg, photoconductor drum) is usually removed. Difficult, and further improvements are needed.

The problem caused by the broadening of the particle size distribution of the toner as described above is caused by the fact that the flying state of the toner from the developer carrying member onto the photosensitive drum during development differs depending on the toner particle size. For example, as shown in FIG. 2, in a one-component magnetic toner having a general particle size distribution created by a pulverization method, the number average particle size is Y (about 7 μm) and the small particle size X (about 3.5 μm). Table 3 below shows a comparison of the toner tribos at three points of Z (about 10 μm) on the large particle size side.

[0010]

[Table 1]

This result shows that the toner tribo is almost proportional to the surface area of the toner (the square of the toner particle size), as is conventionally said, but the flying state of the toner (developing ability) is like this. The shape factor of various toners greatly affects
For example, as shown in FIG. 3, there occurs a phenomenon in which the flying toner particle size is different due to the development contrast (potential difference between the developer (toner) carrier holding toner and the latent image on the photoconductor). Here, it can be seen that the smaller the development contrast is, the more the toner on the small particle size side where the toner tribo is large flies. In this experiment, using a Canon copying machine: NP6650, the toner flying to the photoconductor on which the latent image of each development contrast (0, 200, 400v) was formed was sampled and the particle size distribution was measured.

The particle size distribution of these toners is 100
Coulter counter T with μm aperture
The measurement was performed by connecting an interface (manufactured by Nikkaki Co., Ltd.) and a CX-i personal computer (manufactured by Canon Inc.) that output a number average distribution and a volume average distribution to the A-II type (manufactured by Coulter Inc.). As the electrolytic solution, a 1% NaCl aqueous solution prepared using primary sodium chloride was used, and a surfactant, preferably an alkylbenzene sulfonate, was added as a dispersant in 100 to 150 ml of this electrolytic aqueous solution. Add 5 ml and 0.5 to 50 mg of measurement sample.
Use the added electrolyte solution. The electrolyte solution in which such a measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the dispersion is treated with a Coulter Counter TA-II type to
The particle size distribution of particles of ˜40 μm was measured to obtain the number average distribution and the volume average distribution, and the number average particle size and the volume average particle size were obtained from them.

As a developing method in this experiment, for example, the method described in Japanese Patent Publication No. 59-32375, that is, the photosensitive drum 1 and the developing sleeve (developer carrying member) shown in FIG.
A so-called non-contact developing method was used in which an alternating electric field in which a direct current was superposed on the developing layer 3 was applied to transfer the thin layer developer on the developing sleeve 3 to the electrostatic latent image on the photosensitive drum 1. This is because the width of the facing distance between the developing sleeve 3 and the photosensitive drum 1 is 250 μm.
This is a developing method (so-called non-contact developing or jumping developing method) in which toner is ejected from the developing sleeve 3 to the photosensitive drum 1 by an electric field within a distance smaller than m. Here, a latent image of + 600V in the dark portion and 0V in the bright portion on the photosensitive drum 1 is formed, and a developing bias in which a DC voltage of + 150V is superimposed on a peak-peak voltage of 1400V and a rectangular wave alternating voltage of 1800Hz is applied to the developing sleeve 3. I did an experiment.

In this case, although an alternating electric field is superposed as the developing bias, the thin layer developer on the developing sleeve 3 is also brought into contact with the photosensitive drum 1 in the apparatus in which the developing bias of only the DC component is applied. Even in the contact development, the various phenomena caused by such difference in particle size occur.
Eliminating the effects of such toner particle size differences, for example,
Various developing devices have been proposed or put into practical use so that toner tribo can be uniformly applied, but no device solves this problem.

Although toner tribo is controlled by using external additives such as silica, alumina and titanium oxide, the external addition amount of these external additives to the toner is an average of the particle size distribution of the toner. It is a condition, and it is not possible to add a large amount of toner to the small particle size toner having a large specific surface area, and to control a small amount of external addition to the large particle size toner having a small specific surface area. The broader the particle size distribution of the toner, the smaller the amount of toner having an appropriate external addition amount on both ends of the particle size distribution.

For this reason, the difference in the flying particle diameter due to the development contrast changes the shape of the toner particle size distribution over time and deviates from the initially set developing conditions such as the developing bias, so that the image density is lowered. In addition, the image quality is deteriorated such that the fog in the non-image area is increased. Further, as the fluidity improver of the toner, for example, an external additive such as silica, alumina or titanium oxide is used. These external additives are added to the toner after classification in proper amounts and then mixed with the toner by a mixing and stirring means such as a Henschel mixer. Here, FIG. 5 is a graph showing the change in the degree of aggregation of the toner when the amount of the external additive added to the three types of toner having different number average particle diameters is changed. The fluidity of the toner greatly affects the rising characteristics of the toner tribo, the stability of the toner coating on the developer carrier, the easiness of mixing the carrier and the toner in the two-component developer, and the like. The aggregation degree is a measure for measuring the fluidity of the toner, and the measuring method is as follows.

Cohesion Degree Measuring Method The cohesion degree is used as one means for measuring the fluidity characteristics of a sample (such as a developer having an external additive added externally). The larger the value of this cohesion degree, the more the flow of the sample. Judge that sex is bad. A powder tester (manufactured by Hosokawa Micron Co., Ltd.) is used as the measuring device. As a measuring method, set 200 mesh, 100 mesh and 60 mesh sieves on the vibrating table in the order of narrow opening, that is, set 200 mesh, 100 mesh and 60 mesh sieve in order of 60 mesh sieve at the top. To do.

5 g of an accurately weighed sample was added to the set 60 mesh sieve, and the input voltage to the shaking table was set to 2
Adjust so that it becomes 1.7V, and the amplitude of the vibrating table at that time is 6
Adjust so that it falls within the range of 0 to 90 μm (rheostat scale: about 2.5), and apply vibration for about 15 seconds. Then, the weight of the sample remaining on each sieve is measured to obtain the aggregation degree according to the following formula.

Aggregation degree (%) = 60 weight of sample on mesh sieve / 5 g × 100 + 100 weight of sample on mesh sieve / 5 g × 100 × 3/5 + 200 weight of sample on sieve / 5 g × 100 × 1/5 The sample was left in an environment of 23 ° C./60% RH for about 12 hours, and the measurement environment was the same. or,
For this measurement, a material similar to the toner of Canon Copier: NP6650, with different particle size, was used.
Silica fine particles were used as an external additive.

From FIG. 5, the external addition amount of the external additive of each toner has an appropriate value for minimizing the cohesion degree according to the average particle diameter, and when the external addition amount becomes excessive, the cohesion degree increases again, It can be seen that the effect of the external additive tends to decrease. In this way, the appropriate condition for the amount of the external additive added is that the toner particle size (5, 7, 8 μ
The difference depending on m) is that, like the tribo distribution of the toner as described above, the fluidity differs depending on the particle size, and the broader the particle size distribution of the toner, the toner having appropriate external addition conditions on both end sides of the particle size distribution. Indicates that there is less. The change in the degree of cohesion due to these external addition conditions is that the external additive is gradually coated on the toner surface from the initial external addition to an appropriate value (minimum value of the degree of cohesion), and is sandwiched as spacer particles between the toners. The effect of the surface energy between the external additives is reduced, but it is considered that when the external addition amount exceeds an appropriate value, the effect as a spacer decreases due to electrostatic aggregation of the external additives.

Further, when there is a step of transferring a toner image, a step of removing the toner remaining on the photoconductor is usually provided, but this photoconductor surface cleaning means typified by blade cleaning is provided. In general, it is difficult to remove the toner on the small particle size side. This is because the toner on the small particle size side is likely to rub through the contact portion between the photoconductor and the blade, and because the toner tribo is high, the adhesion force due to the mirroring force or the like on the photoconductor becomes large.

Further, since the toner produced by the suspension polymerization method as described above becomes spherical fine particles, the toner is more likely to rub through the contact portion between the photosensitive member and the blade. Therefore, there is also a method of adding an appropriate amount of a cleaning aid or the like, but like the external additives such as the above-mentioned fluidity improver, the appropriate value of the external addition amount with respect to the average particle diameter is Since it becomes insufficient for the toner of a large small particle size side, the fluidity is deteriorated, and not only the cleaning ability is deteriorated but also the problems such as fog in the non-image area and toner scattering are caused. Next, FIG.
A graph showing changes in toner cohesion degree with mixing and stirring time (hereinafter referred to as external addition time) is shown in FIG.

Here, as shown in FIG. 7, the external addition time of the external additive is appropriate, and when the external addition time becomes excessive, the cohesion degree of the toner rises again and the effect of the external additive decreases. I understand.
Further, the appropriate condition of the external addition time is that the toner average particle size (5,
7 to 8 μm), and when externally added under the same conditions as in the past, the fluidity varies depending on the particle size, and the broader the particle size distribution is, the toner having appropriate external addition conditions on both end sides of this particle size distribution. It can be seen that

The change in the degree of cohesion with these external addition times is
Appropriate value from the initial stage of external addition (external addition time when the degree of cohesion becomes the minimum value)
Until the toner surface is gradually covered with the external additive and is sandwiched between the toner as spacer particles, the influence of the surface energy between the toners is reduced, but the external addition time is a proper value. It is considered that when the temperature exceeds the above range, the external additive is embedded in the toner surface due to heat and pressure generated by collision of each of these external additives during stirring, and the effect as a spacer is reduced. When the external additive is embedded in the toner surface in this manner, it can be said that the effective amount of the external additive on the toner surface is reduced.

Further, although the fusion of the toner to the fixing roller (so-called offset) differs depending on the internal addition amount of the lubricant that functions as a releasing agent at the time of fixing, the deposition rate of the lubricant on the toner surface is large, and the toner has a large particle size. The toner has a problem that it easily causes offset. Further, the magnetic powder in the magnetic toner causes a constraint or friction to the developing sleeve due to the magnetic force generated by the magnetic field generating means arranged in the developing sleeve,
At the same time as providing tribo to the toner, it also serves as a charge leakage site for excessive tribo application. Therefore, the deposition rate of the magnetic powder on the toner surface is effective even under these conditions. In order to control the deposition rate of these internal additives on the toner surface, a method has been proposed in which the addition weight of the internal additives to the toner binder is changed by the particle size, but the internal addition weight should be as small as possible. Is preferable in the toner production method.

Therefore, an object of the present invention is to provide a toner which solves the above problems. That is, the object of the present invention is to minimize the difference in the developing conditions between the respective particle sizes due to the broadening of the particle size distribution of the toner, to keep the image density high for a long period of time, and to obtain a stable image without fog in the non-image area. An object of the present invention is to provide a toner having high quality. Another object of the present invention is to provide a toner having a function capable of stably cleaning the photoconductor for a long period of time. Another object of the present invention is to provide a toner that does not stain the inside of the apparatus due to scattering or the like for a long period of time.

[0027]

The above object can be achieved by the present invention described below. That is, the first invention of the present invention is characterized in that at least two kinds of toner particle groups having different average particle diameters and different particle diameters of at least one kind of external additive externally added are mixed. It is a developer for electrophotography,
The second invention is to provide at least two types of toner particle groups A and B.
And a toner particle group A having an average particle size smaller than B and different external addition conditions of the external additive, which is a developer for electrophotography (here, the external addition conditions are: External loading time, refers to the load conditions of the external addition device such as the rotation speed and capacity of the mixer), and the third invention is different in the average particle size, the particles of at least one internal additive to be internally added to each An electrophotographic developer comprising a mixture of at least two types of toner particle groups having different diameters.

[0028]

According to the above-mentioned constitution of the present invention, the problems of the prior art are solved, and the difference in the developing conditions between the respective particle sizes due to the broadening of the particle size distribution of the toner is minimized, and the image density is maintained for a long time. The image quality is high, stable image quality with no fog in the non-image area can be obtained, and it has the function of being able to stably clean the photoconductor for a long period of time. It is possible to provide toner that does not.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. First, the material and manufacturing method of the developer in the present invention will be described. As the binder (binder resin) used in the present invention, polystyrene,
Monopolymers of styrene such as poly-p-chlorostyrene and polyvinyltoluene, and their substitution products; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-
Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene--2-ethylhexyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methacrylic acid Methyl copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer,
Styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer Polymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-
Styrene-based copolymers such as maleic acid ester copolymers;
Polymethylmethacrylate, polybutylmethacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene,
Polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, Paraffin wax and the like can be used, and they can be used alone or as a mixture.

As the colorant used in the toner of the present invention, if necessary, all known colorants can be used. For example, carbon black, iron black, graphite, nigrosine, a metal complex of a monoazo dye. , Dye pigments such as ultramarine, copper phthalocyanine, methylene blue, chrome yellow, quinoline yellow, Hansa yellow, benzidine yellow, DuPont oil red, quinacridone and various lake pigments can be used. The content of such a colorant is 2 to 100% by weight of the resin of the non-magnetic toner particles.
It is preferably about 30% by weight. When it is contained in the magnetic toner, it is preferably about 0.5 to 15% by weight with respect to 100% by weight of the magnetic toner particles.

A charge control agent is added to the toner of the present invention as needed in order to control the charge polarity and charge amount. In the present invention, a known appropriate charge control agent may be selected according to the polarity and charge amount of the intended toner, and there is no particular limitation. Examples include metal complex azo dyes and nigrosine dyes, which are selected according to the required characteristics. The content of such a charge control agent is 100% by weight of the resin in the non-magnetic toner particles.
It is desirable that the amount is about 0.2 to 10% by weight. When it is contained in the magnetic toner, it is preferably about 0.2 to 10% by weight with respect to 100% by weight of the magnetic toner particles.

Lubricants such as waxes are added as necessary as releasing agents at the time of fixing to prevent offset, and various known waxes such as polyethylene wax, polypropylene wax and silicone wax are used. Any wax may be used, and these are selected according to the required characteristics. The content of such wax is 2 to 100% by weight of the resin in the non-magnetic toner particles.
It is preferably about 10% by weight. Further, in the magnetic toner, it is desirable that the content is about 0.5 to 10% by weight with respect to 100% by weight of the resin.

Next, the method for producing the toner of the present invention will be described. Colorant, charge control agent, wax,
Necessary ones are selected from magnetic powder and other additives, and these predetermined amounts and resin are melted and kneaded, cooled, and then coarsely crushed by a hammer mill, a cutter mill or the like. Then, after further finely pulverizing with a jet mill, an Ong mill or the like, classification is performed so as to obtain a preferable volume average or number average particle size range. The average particle size thus created is, for example,
Classified product C having a particle size distribution of about 7 μm is classified again into A having a particle size distribution having an average particle size of about 5 μm and B having a particle size distribution of about 8 μm as shown in FIG. If necessary, external additives such as a fluidity improver, a lubricant, an abrasive, a conductivity-imparting agent, and a fixing aid are added to the respective toner groups A and B, and they are mixed and stirred.

In the first aspect of the present invention, the particle size of at least one external additive externally added to the toner group A at this time is B.
Change from the group. In this way, at least one kind of external additive having a different particle size is added and mixed and stirred in the toner group A.
Proper amounts of B and B are added in appropriate amounts so as to have a predetermined average particle diameter, and then mixed and stirred again to complete the toner of the present invention. At this time, the external addition time of each of the toner groups A and B varies depending on the actual conditions of the apparatus and the like, but is determined by the time of the minimum value of the aggregation degree in the average particle size of each toner group.

FIG. 6 is a graph showing changes in the degree of cohesion of toners having the same quality of external additives having different particle diameters and having different external addition amounts. In this experiment, a copying machine manufactured by Canon Inc .: a material equivalent to the toner of NP6650 and classified so as to have a number average particle diameter of 5 μm, and the average primary particle value as an external additive is 10 to 20 nm and 5 to 15 nm, respectively. The toners (a) and (b) externally added with the same type of silica fine particles having different particle sizes were used. From this, the toner (a) system required an external additive amount of 0.8%, while the toner (b) system required a 0.6% external additive amount. It became possible to approach the degree of cohesion of the toner having a particle diameter of 8 μm mixed with.

These external additives are not limited to silica, but include, for example, alumina, titanium oxide, resin powders such as those described above as toner binders, polytetrafluoroethylene powder, polyvinylidene fluoride powder, molybdenum disulfide, tungsten disulfide, Boron nitride, lead oxide, antimony oxide, strontium sulfate, aluminum sulfate, calcium carbonate, strontium titanate, cerium oxide, strontium oxide, metal salts of higher fatty acids such as zinc stearate, graphite, barium fluoride, calcium fluoride, Known fine particles such as fluorinated carbon, carbon black, and conductive tin oxide may be used, and some of them may simultaneously have two or more types of functions as the above functional agent. or,
Two or more of these may be added to at least one of the toner groups.

Further, the toner of the present invention can be used as a two-component developer by being mixed with carrier particles such as iron powder, glass beads, nickel powder and ferrite powder, if necessary. When the toner is used as a one-component magnetic developer, the magnetic powder may be a ferromagnetic element or an alloy or compound containing these, such as iron such as magnetite, hematite or ferrite, cobalt, nickel or manganese. The conventional magnetic materials such as the alloys and compounds described above and other ferromagnetic alloys may be included. These magnetic powders have an average particle size of 0.03 to 5 μm, preferably
Fine particles of 0.1 to 1 μm and 1 to 100 of toner weight
%, Preferably 20 to 60% by weight. Further, the developing system to which the toner of the present invention can be applied is conventionally known or all similar systems.

Further, in the second aspect of the present invention, the external addition condition of the toner group A at this time is changed from that of the group B, and, for example, the external addition time is larger than that of the toner group A as described above. Also make it longer. Thus, after the external additives are added, the mixed and stirred toner groups A and B are again mixed and stirred to complete the toner of the present invention. Although the appropriate value of each external addition time varies depending on the conditions of the actual device, it is determined by the time at which the cohesion degree becomes the minimum value due to the average particle size of each toner group.

These external additives are as described above, and two or more kinds of these external additives can be added to at least one of the toner groups. Further, in some cases, it is not necessary to add an external additive to the toner group B.

Further, as described above, the toner of the present invention contains 2
It can be used as a component developer or as a one-component magnetic developer. Further, the developing system to which the toner of the present invention can be applied is conventionally known or all similar systems.

The same applies to the third aspect of the present invention.

If the average particle size of these internal additives is too small, they tend to agglomerate, resulting in poor environmental resistance. On the other hand, if the average particle size is too large, the surface of the toner may be excessively protruded or unevenly distributed, which is not preferable, and in the case of a color toner, the hue may be changed. In the present invention, the measurement of the average particle diameter and the observation of the shape of the above-mentioned internal additive were carried out as follows. Transmission electron microscope (manufactured by Hitachi Ltd.)
H-700H) was used to photograph a collodion copper film mesh or the like at an overvoltage of 100 KV and photographed at 10,000 times, with a baking magnification of 3 times and a final magnification of 30,0.
00 times. With this, the shape was observed, the maximum length of each particle was measured, and the average thereof was taken as the average particle diameter.

Such colorants, charge control agents, waxes,
Necessary ones are selected from magnetic powder and other additives, and a predetermined amount of these is melt-kneaded with a resin, cooled, and then coarsely pulverized by a hammer mill, a cutter mill or the like. Then, after further finely pulverizing with a jet mill, an Ong mill or the like, it is classified to have a preferable volume average or number average particle size range, and this is designated as A.

Next, in at least one of the internal additives selected in A, the internal additives are used so that the components are the same and only the average particle size is different. , A so as to have an average particle diameter different from that of A, and this is designated as B. The average particle size is about 5
An appropriate amount of A having a particle size distribution of μm and B having an average particle size of about 8 μm was mixed to obtain a classified product C having a particle size distribution of about 7 μm as shown in FIG. . After this,
If necessary, external additives such as a fluidity improver, a lubricant, an abrasive, a conductivity-imparting agent, and a fixing aid as described above are added to C, and the mixture is stirred again to obtain the toner of the present invention. obtain. These external additives are added to the toner groups A and B, respectively, and then A and B are mixed again to obtain the toner C of the present invention.
May be

Further, two or more of these may be added to at least one of the toner groups having different average particle diameters. At this time, the predetermined amount of the internal additive of each of the toner groups A and B and the resin are melt-kneaded, and after cooling, the conditions are roughly crushed by a hammer mill, a cutter mill or the like, and further by a jet mill, an ong mill or the like. The conditions at the time of pulverization, the classification conditions so as to obtain the average particle size range, and the like may be different as appropriate conditions. The same applies to external addition conditions. Further, the toner of the present invention can be used as a two-component developer by being mixed with carrier particles such as iron powder, glass beads, nickel powder and ferrite powder, if necessary. Further, the developing system to which the toner of the present invention can be applied is
In all of the conventionally known or similar systems.

[0046]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the text, “part” or “%” is based on weight unless otherwise specified.

(Example of the First Invention) Example 1 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine and BET
50 parts of magnetite having a specific surface area of 8 m ² / g was mixed and melt-kneaded at 160 ° C. by a roll mill. After cooling, the mixture was roughly pulverized with a hammer mill, finely pulverized with a jet pulverizer, and then classified with an air classifier to obtain a black fine powder having a number average particle diameter of 7 μm.

This was again subjected to an air classifier to divide it into a group A having a number average particle size of about 5 μm and a group B having a number average particle size of about 8 μm. Fine powder (silica) having a particle size of 5 to 15 nm
0.6 part was added, and the mixture was stirred with a Henschel mixer for about 2 minutes. Similarly, 0.4 parts of the same quality silica having an average primary particle size of 10 to 20 nm was added to 100 parts of Group B, and mixed and stirred for about 2 minutes with a Henschel mixer.

After that, both were mixed in proper amounts by a Henschel mixer and again stirred for about 0.5 minutes to obtain a toner of this embodiment having a number average particle diameter of 7 μm. In addition, it is important to weaken the load of the mixing and stirring of the group A and the group B after completion of the external addition, in order not to change the proper external addition conditions of both. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. Further, as compared with the toner of the conventional formulation, the contamination due to the scattering of the toner inside and outside the apparatus is reduced.

Example 2 With respect to groups A and B obtained by the same composition and manufacturing method as in example 1, 100 parts of group A on the small particle size side was treated with silica fine powder (silica) 0. 3 parts, and the average primary particle value is 0.5 to
Add 0.5 parts of cerium oxide having a particle size of 1 μm,
The mixture was stirred with a Henschel mixer for about 5 minutes. For Group B, 0.8 parts of cerium oxide having the same particle size as Group A and having a particle size of 1 to 2 μm was added to 100 parts of Group B, and mixed and stirred for about 2 minutes with a Henschel mixer. After that, they are mixed again with a Henschel mixer, and the number average particle size is 7μ.
m toner of this example.

This example is an example in which the amounts and types of the external additives added to the black fine powder groups A and B are changed and a plurality of external additives are added to at least one of them. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. In addition, compared to conventional toner,
Contamination due to toner scattering inside and outside the apparatus is reduced, and the durable life of the cleaning means (cleaning blade) for the photoconductor is significantly improved.

Example 3 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine and 50 parts of magnetite having a BET specific surface area of 8 m ² / g were mixed and melt-kneaded at 160 ° C. in a roll mill. did. After cooling, coarsely pulverize with a hammer mill, finely pulverize with a jet pulverizer, and then classify with a wind classifier to obtain a number average particle size of about 8μ.
A group B of black fine powder of m was obtained. On the other hand, except that 3 parts of nigrosine and 70 parts of magnetite were used, a group A of black fine powder having a number average particle diameter of about 5 μm was obtained through the same manufacturing process as the group B.

Next, to 100 parts of the black fine powder group A, 0.3 part of silicic acid fine powder (silica) having a primary particle average particle diameter of 5 to 15 nm was added, and the mixture was mixed by a Henschel mixer. Mix and stir for 4 minutes. Similarly, the same quality silica having an average primary particle diameter of 10 to 20 nm is used as a group B 1
0.3 part was added to 00 parts, and the mixture was stirred with a Henschel mixer for about 2 minutes. After that, they were mixed again with a Henschel mixer to obtain a toner of this example having a number average particle size of 7 μm.

The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is stable and excellent. Further, as compared with the toner of the conventional formulation, the contamination due to the toner scattering inside and outside the apparatus was reduced. As described above, the present invention is effective even if the types and the amounts of the internal additives of the groups A and B are different.

Example 4 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine and 50 parts of magnetite having a BET specific surface area of 8 m ² / g were mixed and melt-kneaded at 160 ° C. in a roll mill. did. After cooling, after roughly crushing with a hammer mill, finely crushing with a jet crusher,
Then, classify using a wind classifier to obtain a number average particle size of about 8
A group B of black fine powder of μm was obtained.

Next, to 100 parts of the black fine powder group B, 0.3 part of silicic acid fine powder (silica) having a primary particle average value of 10 to 20 nm was added, and the mixture was mixed with a Henschel mixer. The mixture was stirred for about 2 minutes. In addition, except that nigrosine was changed to 3 parts and magnetite was changed to 70 parts by the suspension polymerization method, an almost spherical black fine powder group A having the same composition as the group B and a number average particle diameter of about 5 μm was obtained, Similar to Group B, the same quality silica having an average primary particle size of 5 to 15 nm is used as A
0.3 part was added to 100 parts of the group, mixed for about 3 minutes with a Henschel mixer, and finally both were mixed to obtain a toner of this example having a number average particle size of 7 μm. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. As described above, the present invention is effective even if the manufacturing methods of the toners of the group A and the group B are different.

Example 5 Styrene 185 parts Trifluoroethyl acrylate 15 parts Cyclized rubber [Alvex CK-450 (Hoechst Japan Co.)] 10 parts Cyanine Blue 4920 (Dainichi Seika Co., Ltd.) 20 parts Paraffin wax T-550 (manufactured by Nippon Seiro Co., Ltd.) 32 parts Polymerization initiator [V-601 (manufactured by Wako Pure Chemical Industries)] 10 parts

The above formulation was heated to 70 ° C. in a container and dissolved or dispersed to prepare a monomer system. Separately, ion-exchanged water 1
Aminoalkyl modified colloidal silica is added to 200 ml.
Add 0 g, adjust pH to 6 with HCl, and add Na ₂ CO ₃
1 g, and heated to 70 ° C., using a TK homomixer M type (manufactured by Tokushu Kika Kogyo) for 10,000 r. p. dispersed for 15 minutes. Further, Al ₂ (SO ₄ ) ₃ was added to 1.
Add 1 g, 10,000 r. p. Disperse for 15 minutes at m,
A dispersion medium is adjusted, the above-mentioned monomer composition is added, and the mixture is heated to 1000 ° C. in a nitrogen atmosphere at 70 ° C. using a TK homomixer.
0r. p. The mixture was stirred for 60 minutes at m to granulate the monomer composition.

Then, while stirring with a paddle stirring blade, 70
Polymerization was performed at 10 ° C for 10 minutes. After the completion of the polymerization reaction, the reaction product was cooled, NaOH was added to dissolve the dispersant, and the polymerized toner was obtained by filtering, washing with water and drying. Next, the stirring conditions were changed, and this step was repeated again to produce a group A having a number average particle size of about 5 μm and a group B having a number average particle size of about 8 μm. For 100 copies of group A thus completed,
0.3 part of fine silicic acid powder (silica) having an average primary particle diameter of 5 to 15 nm and 0.5 part of strontium titanate fine powder as a cleaning aid are added, and mixed with a Henschel mixer for about 3 minutes. It was stirred.

Similarly, the average primary particle value is 10 to 20 nm.
0.3 parts of the same quality silica having a particle size of 100 parts to group B is added, the stirring condition of the Henschel mixer is made weaker than the external addition condition of group A, and the mixture is stirred for about 2 minutes, then both are mixed. The toner of this example has a number average particle size of 7 μm. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. Further, as compared with the toner of the conventional formulation, there is less stain due to toner scattering inside and outside the apparatus, and it is also effective for cleaning the surface of the photoreceptor of the toner prepared by the polymerization method. In this way, it is effective to change the external addition condition between the A group and the B group.

Example of Second Invention Example 6 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine and BET
50 parts of magnetite having a specific surface area of 8 m ² / g was mixed and melt-kneaded at 160 ° C. by a roll mill. After cooling, the mixture was roughly pulverized with a hammer mill, finely pulverized with a jet pulverizer, and then classified with an air classifier to obtain a black fine powder having a number average particle diameter of 7 μm. This is again subjected to a wind classifier to divide into a group A having a number average particle size of about 5 μm and a group B having a number average particle size of about 8 μm, and 100 parts of the group A is finely powdered with silica (silica) 0 .3 parts was added, and the mixture was stirred with a Henschel mixer for about 4 minutes. Similarly, 0.3 part of the same quality silica was added to 100 parts of Group B, and mixed and stirred for about 2 minutes with a Henschel mixer.

Then, both groups A and B were stirred again for about 0.5 minutes with a Henschel mixer, and the number average particle size was adjusted to 7
The toner of this example has a size of μm. Incidentally, it is important to weaken the load of the mixing and stirring of the black fine powders A and B after completion of the external additive, in order not to change the proper external addition conditions of both. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. Further, as compared with the toner of the conventional formulation, the toner due to toner scattering inside and outside the apparatus is less likely to be contaminated.

Example 7 With respect to black fine powders A and B obtained by the same composition and production method as in Example 6, 100 parts of A group on the small particle size side was treated with silica fine powder (silica). ) 0.3 part and 0.5 part of cerium oxide were further added, and the mixture was stirred with a Henschel mixer for about 5 minutes. Further, 0.3 part of the same quality silica was added to 100 parts of Group B, and the mixture was stirred with a Henschel mixer for about 2 minutes.
After that, they were mixed again with a Henschel mixer to obtain a toner of the present invention having a number average particle diameter of 7 μm.

In this example, the amount and kind of the external additive added to the groups A and B were changed, and when a plurality of external additives were added to at least one side, the external addition of the small particle size group A was performed. Try to increase the load. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. Further, as compared with the toner of the conventional formulation, the contamination due to toner toner scattering inside and outside the apparatus is reduced, and the durability life of the cleaning means (cleaning blade) of the photoconductor is significantly improved.

Example 8 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine and BET
50 parts of magnetite having a specific surface area of 8 m ² / g was mixed and melt-kneaded at 160 ° C. by a roll mill. After cooling, coarse pulverization was performed using a hammer mill, fine pulverization was performed using a jet pulverizer, and classification was performed using an air classifier to obtain a black fine powder group B having a number average particle size of about 8 μm. On the other hand, except that nigrosine was changed to 3 parts and magnetite was changed to 70 parts, the number average particle size was about 5 μm through the same manufacturing process with the same composition as Group B.
m black fine powder group A was obtained.

Next, 0.3 part of silicic acid fine powder (silica) was added to 100 parts of group A of black fine powder, and the mixture was stirred with a Henschel mixer for about 4 minutes. Similarly, 0.3 part of the same quality silica was added to 100 parts of Group B, and mixed and stirred for about 2 minutes with a Henschel mixer. After that, they were mixed again with a Henschel mixer to obtain a toner of this example having a number average particle size of 7 μm.

The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is stable and excellent. Further, as compared with the toner of the conventional formulation, the amount of stains due to toner toner scattering inside and outside the apparatus was reduced. As described above, the present invention is effective even if the types and the amounts of the internal additives of the groups A and B are different.

Example 9 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine and BET
50 parts of magnetite having a specific surface area of 8 m ² / g was mixed and melt-kneaded at 160 ° C. by a roll mill. After cooling, coarse pulverization was performed using a hammer mill, fine pulverization was performed using a jet pulverizer, and classification was performed using an air classifier to obtain a black fine powder group B having a number average particle size of about 8 μm. Next, for 100 parts of Group B of this black fine powder, silicic acid fine powder (silica)
0.3 part was added, and the mixture was stirred with a Henschel mixer for about 2 minutes.

Also, except that 3 parts of nigrosine and 70 parts of magnetite were used by the suspension polymerization method, a group A of substantially spherical black fine powder having the same composition as the group B and having a number average particle diameter of about 5 μm was prepared. In the same manner as in Group B, 0.3 parts of the same quality silica was added to 100 parts of Group A, mixed for about 3 minutes by a Henschel mixer, and finally both were mixed to obtain a number average particle size of 7 μm. Of toner. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. As described above, the present invention is effective even if the manufacturing methods of the toners of the group A and the group B are different.

Example 10 styrene 185 parts trifluoroethyl acrylate 15 parts cyclized rubber [Alvex CK-450 (Hoechst Japan Co.)] 10 parts cyanine blue 4920 (Dainichi Seika Co., Ltd.) 20 parts Paraffin wax T-550 (manufactured by Nippon Seiro Co., Ltd.) 32 parts Polymerization initiator [V-601 (manufactured by Wako Pure Chemical Industries)] 10 parts

The above formulation was heated to 70 ° C. in a container to dissolve or disperse it to prepare a monomer system. Separately, 10 g of aminoalkyl-modified colloidal silica was added to 1200 ml of ion-exchanged water, pH was adjusted to 6 with HCl, and Na ₂ CO was added.
1g of ₃ was added and heated to 70 ° C, TK type homomixer M
Using a mold (made by Tokushu Kika Kogyo), 10,000 r. p. m
Dispersed for 15 minutes. Further, 1.1 g of Al ₂ (SO ₄ ) ₃ was added, and 10000 r.p.m. p. m for 15 minutes, the dispersion medium is adjusted, the above monomer composition is added, and the mixture is mixed at 10 ° C. in a nitrogen atmosphere at 70 ° C. using a TK homomixer for 10 minutes.
000r. p. The mixture was stirred for 60 minutes at m to granulate the monomer composition. After that, while stirring with a paddle stirring blade,
It polymerized in 10 minutes. After the completion of the polymerization reaction, the reaction product was cooled, NaOH was added to dissolve the dispersant, and the polymerized toner was obtained by filtering, washing with water and drying.

Next, the stirring conditions were changed and this step was repeated again to prepare a group A having a number average particle size of about 5 μm and a group B having a number average particle size of about 8 μm. The finished A
0.3 part of silicic acid fine powder (silica) and 0.5 part of strontium titanate fine powder as a cleaning aid were added to 100 parts of the group, and the mixture was stirred with a Henschel mixer for about 3 minutes.

Similarly, 0.3 part of the same quality silica was added to 100 parts of the group B, the stirring condition of the Henschel mixer was made lower than the external addition condition of the group A, and the mixture was stirred for about 2 minutes, and then both were mixed. The toner of this example has a number average particle size of 7 μm. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. In addition, compared to the conventional prescription toner, there is less dirt due to toner scattering inside and outside the device,
The toner prepared by the polymerization method was also effective for cleaning the surface of the photoconductor. As described above, the external addition condition is not limited to the external addition time, and any method is effective as long as it changes the load condition at the time of external addition to the toner.

(Example of the Third Invention) Example 11 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine having an average particle size of 1.0 μm, and magnetite 70 having an average particle size of 0.2 μm.
The parts were mixed and melt-kneaded at 160 ° C. in a roll mill.
After cooling, coarse pulverization was performed using a hammer mill, fine pulverization was performed using a jet pulverizer, and classification was performed using an air classifier to obtain a black fine powder A having a number average particle diameter of 5 μm. Similarly, 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine having an average particle size of 1.8 μm and 70 parts of magnetite having an average particle size of 0.2 μm are mixed and melted at 160 ° C. by a roll mill. Kneaded After cooling, coarse pulverization was performed using a hammer mill, fine pulverization was performed using a jet pulverizer, and classification was performed using an air classifier to obtain a black fine powder B having a number average particle diameter of 8 μm.

This black fine powder A having a number average particle diameter of about 5 μm
The group and the black fine powder group B having a number average particle diameter of about 8 μm were mixed with an appropriate amount of Henschel mixer for about 0.5 minutes to obtain a black fine powder having a number average particle diameter of 7 μm. Next, with respect to 100 parts of this black fine powder having a number average particle diameter of 7 μm, 0.3 part of silicic acid fine powder (silica) and 0.5 part of cerium oxide were further added.
And the mixture was stirred again for about 2 minutes with a Henschel mixer to obtain the toner of this example. The toner produced through such a process has more uniform and stable tribo than the conventional product, and the image quality of the copied image is stable and excellent. Further, as compared with the toner of the conventional formulation, the contamination due to the toner scattering inside and outside the apparatus is reduced.

Example 12 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine having an average particle size of 1.0 μm, and magnetite 7 having an average particle size of 0.1 μm
0 parts were mixed and melt-kneaded at 160 ° C. in a roll mill. After cooling, coarse pulverization was performed using a hammer mill, fine pulverization was performed using a jet pulverizer, and classification was performed using an air classifier to obtain a black fine powder A having a number average particle diameter of 5 μm. Similarly, 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 4 parts of nigrosine having an average particle size of 1.8 μm and 60 parts of magnetite having an average particle size of 0.2 μm are mixed and melted at 160 ° C. in a roll mill. Kneaded

After cooling, after roughly crushing with a hammer mill,
The mixture was finely pulverized with a jet pulverizer and then classified with an air classifier to obtain a black fine powder B having a number average particle diameter of 8 μm. The black fine powder group A having a number average particle size of 5 μm and the black fine powder group B having a number average particle size of 8 μm are stirred for about 0.5 minutes with an appropriate amount of a Henschel mixer to give a number average particle size of 7
A black fine powder of μm was obtained. Next, this number average particle size 7μ
To 100 parts of black fine powder of m, 0.3 part of silicic acid fine powder (silica) and 0.5 part of cerium oxide were added,
The toner of this example was obtained by mixing and stirring with a Henschel mixer for about 2 minutes. This example is an example in the case where the amount and kind of the internal additive to be added to the groups A and B are changed and a plurality of internal additives are added to at least one. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent.

Example 13 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine having an average particle size of 1.8 μm, and magnetite 70 having an average particle size of 0.2 μm
The parts were mixed and melt-kneaded at 160 ° C. in a roll mill.
After cooling, coarse pulverization was performed using a hammer mill, fine pulverization was performed using a jet pulverizer, and then classification was performed using an air classifier to obtain a black fine powder group B having a number average particle diameter of 8 μm.

Next, 100 parts of styrene-2-ethylhexyl acrylate-divinylbenzene copolymer, 5 parts of nigrosine having an average particle size of 1.0 μm and an average particle size of 0.2 μm.
70 parts of magnetite of No. 2 was prepared by a suspension polymerization method, and a substantially spherical black fine powder having a number average particle diameter of about 5 μm was classified by using an air classifier to obtain a black fine powder A having a number average particle diameter of about 5 μm.
A group was obtained.

This black fine powder A having a number average particle diameter of about 5 μm
The group and a group of black fine powder B having a number average particle diameter of about 8 μm were mixed with an appropriate amount of a Henschel mixer for about 0.5 minutes to obtain a black fine powder having a number average particle diameter of 7 μm. Next, to 100 parts of the black fine powder having a number average particle diameter of 7 μm, 0.3 part of silicic acid fine powder (silica) and 0.5 part of cerium oxide were added and mixed with a Henschel mixer for about 2 minutes. The toner of this example was obtained by stirring. The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. As described above, the present invention is effective even if the manufacturing methods of the toners of the group A and the group B are different.

Example 14 styrene 185 parts trifluoroethyl acrylate 15 parts cyclized rubber [Alvex CK-450 (manufactured by Hoechst Japan)] 10 parts cyanine blue (manufactured by Dainichiseika Co., Ltd.) average particle size 0.1 μm 20 parts Paraffin wax T-550 (manufactured by Nippon Seiro Co., Ltd.) 32 parts Polymerization initiator [V-601 (manufactured by Wako Pure Chemical Industries)] 10 parts The above formulation is heated to 70 ° C. in a container. Dissolve or disperse,
A monomer system was prepared. Separately, ion-exchanged water 1200 ml
Add 10 g of aminoalkyl modified colloidal silica to
The pH was adjusted to 6 with HCl, 1 g of Na ₂ CO ₃ was further added, the mixture was heated to 70 ° C., and a TK type homomixer M type (manufactured by Tokushu Kika Kogyo) was used for 10,000 r. p. dispersed for 15 minutes.

Further, 1.1 g of Al ₂ (SO ₄ ) ₃ was added, and 10,000 r.p.m. p. m for 15 minutes, the dispersion medium is adjusted, the above-mentioned monomer composition is added, and the mixture is introduced into a nitrogen atmosphere at 70 ° C. using a TK homomixer at 17,000 rpm.
p. The mixture was mixed for 60 minutes at m to granulate the monomer composition. Then, polymerization was carried out at 70 ° C. for 10 minutes while stirring with a paddle stirring blade. After the completion of the polymerization reaction, the reaction product is cooled and NaO is added.
H was added to dissolve the dispersant, followed by filtration, washing with water and drying to obtain a group A having a number average particle diameter of about 5 μm.

Next, a group B having a number average particle size of about 8 μm was prepared according to the following formulation and preparation conditions. -Styrene 185 parts-Trifluoroethyl acrylate 15 parts-Cyclized rubber [Alvex CK-450 (manufactured by Hoechst Japan)] 10 parts-Cyanine blue (manufactured by Dainichiseika Co., Ltd., average particle size 0.2 μm) 25 parts Paraffin wax T-550 (manufactured by Nippon Seiro Co., Ltd.) 40 parts Polymerization initiator [V-601 (manufactured by Wako Pure Chemical Industries, Ltd.)] 10 parts Dissolve or disperse the above formulation by heating to 70 ° C in a container. A monomer system was prepared. Separately, ion-exchanged water 1200 ml
Add 10 g of aminoalkyl modified colloidal silica to
The pH was adjusted to 6 with HCl, 1 g of Na ₂ CO ₃ was further added, the mixture was heated to 70 ° C., and a TK type homomixer M type (manufactured by Tokushu Kika Kogyo) was used for 10,000 r. p. dispersed for 15 minutes.

Further, 1.1 g of Al ₂ (SO ₄ ) ₃ was added, and 10000 r.p.m. p. m for 15 minutes, the dispersion medium is adjusted, the above-mentioned monomer composition is added, and the mixture is introduced into a nitrogen atmosphere at 70 ° C. using a TK homomixer at 10,000 rpm.
p. The mixture was mixed for 60 minutes at m to granulate the monomer composition. Then, polymerization was carried out at 70 ° C. for 10 minutes while stirring with a paddle stirring blade. After the completion of the polymerization reaction, the reaction product is cooled and Na
Group B was obtained by adding OH to dissolve the dispersant, and filtering, washing with water and drying.

To 100 parts of the thus-prepared group A, 0.3 part of fine powder of silica (silica) and 0.5 part of fine powder of strontium titanate as a cleaning aid were added, and a Henschel mixer was used for about 3 minutes. Mix and stir. Similarly, 0.3 parts of the same quality silica is added to 100 parts of Group B,
The stirring conditions of the Henschel mixer were set lower than the external addition conditions of Group A, and the mixture was stirred for about 2 minutes. In this way, both the group A and the group B, which had been subjected to external addition, were mixed to obtain a toner of this example having a number average particle diameter of 7 μm.

The toner developed with such a constitution has more uniform and stable tribo than the conventional product, and the quality of the image to be copied is also stable and excellent. Further, as compared with the toner of the conventional formulation, there is less stain due to toner scattering inside and outside the apparatus, and it is also effective for cleaning the surface of the photoreceptor of the toner prepared by the polymerization method. As described above, the present invention is effective even if the toner production method is a polymerization method or the like, and the external addition conditions are changed between the groups A and B.

[0087]

【The invention's effect】

(Effect of the first invention) As described above, according to the present invention, at least 1 externally added particles having different average particle sizes.
By mixing and using at least two types of toner particle groups in which the particle sizes of the external additives of different types are mixed, it is possible to minimize the difference in the developing conditions between the particle sizes due to the broadening of the toner particle size distribution, and The image density is high over the entire range, and stable image quality without fog in the non-image area can be obtained. Further, it is possible to stably clean the photosensitive member for a long period of time, and it is possible to prevent the generation of stains inside and outside the apparatus due to toner scattering and the like.

(Effect of Second Invention) As described above,
According to the present invention, the toner is composed of at least two kinds of toner particle groups A and B, and the toner particle group B and the toner particle group A having an average particle size smaller than that of the group B and different external addition conditions are mixed. By using, the difference in development conditions between particle sizes due to the broadening of the toner particle size distribution is minimized, the image density is high for a long period of time, and stable image quality without fog in the non-image area is obtained. can get. Also, for a long time,
It is possible to stably clean the photosensitive member and prevent the generation of dirt inside and outside the apparatus due to toner scattering and the like.

(Effect of the Third Invention) As described above,
According to the present invention, the average particle size is different, and the particle size of at least one kind of internal additive internally added is at least 2
By using a mixture of toner particle groups of different types, the difference in the developing conditions between the particle sizes due to the broadening of the toner particle size distribution is minimized, the image density is high for a long period, and Stable image quality without fog can be obtained. or,
For a long period of time, you can stably clean the photoconductor,
It is possible to prevent stains inside and outside the apparatus due to toner scattering and the like.

[0090]

[Brief description of drawings]

FIG. 1 is a diagram showing a number average particle size distribution in a manufacturing process of a toner of an example of the present invention.

FIG. 2 is a diagram showing a number average particle size distribution of a conventional toner.

FIG. 3 is a diagram showing a relationship between a development contrast of a conventional toner and a particle size distribution of toner flying to a photoconductor.

FIG. 4 is a sectional view showing a schematic configuration of a conventional developing device used in an experiment of the present invention.

FIG. 5 is a diagram showing the relationship between the amount of external additive and the degree of cohesion to the toner having each particle size.

FIG. 6 is a diagram showing the relationship between the amount of external additive and the degree of aggregation of the toner when the particle size of the external additive is changed.

FIG. 7 is a diagram showing a relationship between external addition time and toner cohesion.

[0091]

[Explanation of symbols]

 1: Photoconductor drum 2: Developer supply device (container) 3: Developer carrier (development sleeve) 4: Magnetic field generating means (mag roll) 5: Developer regulating means (magnetic blade) 6, 7: Developer conveying means (Toner feeding member) 8: Development bias power supply T: Developer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location 381 (72) Inventor Tatsuya Tada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Isumi Ito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. An electrophotographic developer comprising a mixture of at least two kinds of toner particle groups having different average particle diameters and at least one kind of external additive having a different particle diameter. 2. At least two types of toner particle groups A and B
And a toner particle group A having a mean particle size smaller than B and different external addition conditions of external additives. 3. An electrophotographic developer comprising a mixture of at least two kinds of toner particle groups having different average particle diameters and at least one kind of internal additive having a different particle diameter. 4. The electrophotographic developer according to claim 3, wherein the internal additive is magnetic powder. 5. The electrophotographic developer according to claim 3, wherein the internal additive is a charge control agent. 6. The electrophotographic developer according to claim 3, wherein the internal additive is a lubricant.