JPH0246469A - Electrophotographic toner and electrophotographic developing agent - Google Patents

Abstract

PURPOSE:To improve fluidity of an electrophotographic toner even if the toner consists of small size particles, to improve the picture quality of a toner image, and to prevent scattering of the toner particles in a developing machine by incorporating an aggregation inhibitor having a specified compsn. CONSTITUTION:The title toner contains an aggregation inhibitor (A) integrated by fixing fine particles (a1) having 0.01-5mum volume average particle size and fine silica particles (a2) having a particle size smaller than that of (a1), together with chargeable toner particles (B). A metal oxide such as TiO2 or a fatty acid metal salt such as zinc stearate may be used for the component (a1). The component (A) is formed an integrated product by mixing the component (a1) with the component (a2) under a mechanical stress. It is preferred that the volume average particle size of (a2) is <=0.5mum and that 40-95wt.% (a2) is contained in (A). 0.05-10ps.wt. component (A) is preferred to be added to 100pts. wt. (B).

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to an electrophotographic toner and an electrophotographic developer for developing a latent image in electrophotography, and in particular, to
The present invention relates to an electrophotographic toner used as a component-based electrophotographic developer, and a two-component electrophotographic developer containing an electrophotographic toner and carrier particles.

<Prior Art> Electrostatic image development in an electrophotographic apparatus is usually performed as follows.

■Charge the surface of the photoreceptor positively or negatively.

■Irradiates the surface of the photoconductor with reflected light from the original.

■The conductivity of the photoconductor increases when it is irradiated with light, so there are areas on the photoconductor surface where the charge disappears and other areas where the charge remains, depending on the strength of the light reflected from the document, and the surface of the photoconductor is latent. An image will be formed.

(2) Development toner charged to the opposite polarity to that on the surface of the photoreceptor is made to adhere to the surface of the photoreceptor from a toner carrier or the like by electrostatic attraction, thereby obtaining an image.

(2) After being transferred to the surface of this visible transfer paper, it is fixed by heating, pressure bonding, etc.

In such electrostatic image development, a one-component toner or a two-component toner is used as the developing toner described in (2) above.

A two-component developing toner is composed of toner particles made of resin powder containing a colorant and carrier particles made of iron, ferrite, or the like.

On the other hand, one-component developing toner does not use carrier particles and is disclosed in, for example, US Pat. No. 3,909,258 and US Pat.
], 21931, consists of magnetic toner particles containing magnetic powder which is itself a colorant.

In these one-component and two-component developing toners, a fluidizing agent such as silica particles is usually added as an anti-aggregation agent in order to prevent toner particles from coagulating with each other.

<Problems to be Solved by the Invention> The one-component and two-component developing toners described above are usually manufactured as follows.

Resin, wax, pigment, charge control agent, etc. are mixed, melted and mixed, and after cooling, a fluidizing agent is added to the crushed and classified toner, and the fluidizing agent is attached to the toner surface by mixing with a Henschel mixer or the like.

As the fluidizing agent, silica particles as shown in Japanese Patent Application Laid-Open No. 46-5782 are generally used, and the average particle diameter of such silica particles is about 0.01 to 5 μm.

The individual particles of the toner obtained by this manufacturing method are generally amorphous and have a wide particle size distribution, so although the conventionally used fluidizing agents such as silica particles are sufficient to prevent toner agglomeration. do not have. In particular, when trying to obtain a high-quality toner image with improved resolution, gradation, etc., it is necessary to use small-sized toner particles with a volume average particle size of, for example, 8 μm or less. Since the fluidity of toner particles is significantly reduced, it is difficult to prevent toner agglomeration using conventional fluidizing agents. For this reason,
Fog increases, image density decreases, and the cleanability of the photoreceptor also decreases. Furthermore, toner scattering within the machine and troubles during toner replenishment are more likely to occur.

Specifically, when silica particles with a particle size of 0.5 μm or more are used as a fluidizing agent, the amount of charge of the silica particles themselves is low, so there is an effect of preventing electrical aggregation, but if they are attached to the toner, Since the surface area of the silica particles becomes smaller, the toner particles tend to repel each other, making it impossible to prevent agglomeration and reducing fluidity.

Furthermore, when silica particles having a particle size of 0.1 μm or less are used as a fluidizing agent, the cleaning properties of the photoreceptor are reduced and the surface of the photoreceptor is easily damaged. Moreover, the smaller the particle size of the silica particles used as the fluidizing agent, the greater the amount of charge, so the effect of electrically preventing agglomeration is low.

Therefore, when silica particles having a particle size of this size are added to a toner, the toner aggregation prevention effect is not improved as much as expected.

Further, the one-component developing toner is charged by friction between the magnetic toner particles and a blade, toner carrier, etc. with which they come into contact, or by friction between the magnetic toner particles. However, in such frictional charging, it is difficult to charge all the toner particles to the same polarity, and since the toner itself is unstable in charging, toner particles tend to aggregate.

In addition, functional particles of various materials (e.g., titanium oxide, titanium oxide,
PMMA fine particles, etc.) are sometimes externally added to toner particles, but these additives have little effect on preventing physical aggregation.
Depending on its properties, particle size, etc., or storage conditions, the fluidity of the toner may be reduced.

The present invention has been made to solve the above-mentioned problems in electrophotographic toners, and even when using toner particles with a small particle size, it has good fluidity and it is possible to obtain high-quality toner images. An object of the present invention is to provide an electrophotographic toner and an electrophotographic developer that can be used in a machine without scattering.

〈Means for solving problems〉 The above objects are achieved by the present invention as described below.

That is, the present invention includes the following (1) to (6).

(1) Contains an anti-aggregation agent in which fine particles having a volume average particle size of 0.01 to 5.0 LLm and silica fine particles having a smaller volume average particle size than the fine particles are fixed and integrated, and charged toner particles. (2) The toner for electrophotography as described in (1) above, wherein the silica fine particles have a volume average particle size of 0.5 μm or less. (3) The aggregation prevention agent comprises silica fine particles. 40~95wt
(4) The toner for electrophotography according to (1) or (2) above, which contains 0.05 to 10 parts by weight of the anti-aggregation agent per 100 parts by weight of the charged toner particles (1).
(5) The electrophotographic toner according to any one of ) to 3), wherein the charged toner particles are magnetic toner particles;
The above (1) used as a one-component electrophotographic developer
Electrophotographic toner according to any one of (6) to (4) above. An electrophotographic developer containing the electrophotographic toner according to any one of (1) to 4) above and carrier particles.

Hereinafter, the specific configuration of the present invention will be explained in detail.

In the present invention, there is no particular restriction on the material of the fine particles, but it is preferable to use functional particles that have functions such as controlling charge and resistance of the toner and improving fluidity. In particular, since the silica fine particles described below used in combination with the fine particles have a relatively high charge amount, it is preferable to select particles having a lower charge amount than the silica fine particles.

The materials of the functional particles suitably used in the present invention include:
Examples include the following:

Oxides such as silicon oxide, titanium oxide, zinc oxide, alumina, calcium silicate; Inorganic compounds such as silicon carbide, calcium carbonate, barium carbonate; Polymethyl methacrylate (PMMA), polyethylene, nylon, silicone resin, phenolic resin, benzoguanamine , organic polymer compounds such as polyester; fluorine-containing organic polymer compounds such as polytetrafluoroethylene and vinylidene fluoride; fatty acid metal salts such as zinc stearate and magnesium stearate; charged chromium complex dyes, nigrosine dyes, etc. Control agent: In addition to these resistance control agents, fluidizing agents, charge control agents, etc., colorants may be used as the fine particles. That is, examples of colorants suitably used as the above-mentioned fine particles include the following.

Black pigments such as carbon black, acetylene black, channel black, aniline black; Dialite Yellow GR, Variotol Yellow 1090
Red pigments such as Permanent Red E5B and Rhodamine 2B; Blue pigments such as copper phthalocyanine and cobalt blue; Green pigments such as Pigment Green B; Eko-colored pigments such as pyrazolone orange; Various functional particles listed above Among these, metal oxides and fatty acid metal salts are particularly preferably used in the present invention.

These fine particles may be appropriately selected depending on the charging characteristics such as the polarity and amount of charge of the toner particles used, the type of photoreceptor used, and the like.

In the present invention, the volume average particle diameter of the fine particles is 0.0
The thickness is 1 to 5 μm, preferably 0.04 to 4 μm. If the particle size is less than the above range, the agglomeration prevention effect will be insufficient and fluidity will deteriorate. Exceeding the above range may cause image quality deterioration such as fogging and resolution.

In the present invention, silica fine particles having a volume average particle size smaller than the above-mentioned fine particles are used as a fluidizing agent. The volume average particle diameter of the silica fine particles is preferably 0.5 μm or less, more preferably 0.001 to 0.5 μm, and still more preferably 0.01 to 0.1 μm. When the volume average particle diameter is outside the above range, it becomes difficult to prevent electrical aggregation.

Further, from the viewpoint of stability under various environmental conditions, the silica fine particles are preferably made hydrophobic by surface treatment.

The silica fine particles preferably used in the present invention include R-972, R-974, and R-972 manufactured by Nippon Aerosil Co., Ltd.
976, RX-200, etc.

In the present invention, the above-mentioned fine particles and silica fine particles are fixed and integrated to form an anti-agglomeration agent.

In the present invention, the term "fixing and integrating fine particles and fine silica particles" means that the fine particles are embedded in the surface of the fine particles.

In other words, when observed using an electron microscope, it can be confirmed that the silica particles are embedded in the surface of the particles, and it is extremely difficult to separate the silica particles that are firmly integrated. It is something to keep.

It is thought that the anti-aggregation agent having such a structure exhibits an extremely excellent anti-aggregation effect for the following reasons.

Silica fine particles having the above-mentioned volume average particle diameter and being hydrophobic have a high effect of physically preventing aggregation of toner particles, and moreover, the effect is not easily reduced even under high temperature and high humidity. However, as described above, such fine silica particles have a low effect of electrically preventing aggregation of toner particles.

On the other hand, the fine particles mentioned above have almost no effect on physically preventing the aggregation of toner particles, and depending on the material they are made of, they exhibit unstable properties under high temperature and high humidity. Since it is larger than the silica fine particles, the amount of charge is lower than the above-mentioned silica fine particles, and it is highly effective in preventing electrical aggregation of toner particles. In particular, when the above-mentioned charge control agent is used as the fine particles, the effect of preventing electrical aggregation is high.

Therefore, the silica particles embedded in the surface of the particles physically prevent the toner particles from agglomerating, and the effect is stable even under high temperature and high humidity conditions. The fine particles reduce the charge amount of the silica fine particles, thereby reducing the charge amount of the entire anti-aggregation agent, thereby preventing electrical aggregation of toner particles.

In addition, by adopting such a configuration, when trying to obtain the same level of fluidity as the present invention using only silica particles, the amount of silica particles used can be reduced, so cleaning performance is less likely to deteriorate. Furthermore, the photoreceptor is less likely to be damaged.

Further, in the present invention, the fine particles do not necessarily have to have the effect of preventing physical aggregation of the toner, so various functional particles as described above can be used. Therefore, in a one-component developer that tends to cause aggregation of toner particles because the charging characteristics such as charge polarity and amount of charge are likely to become unstable, the above-mentioned aggregation preventing agent prevents both electrical aggregation and physical aggregation of toner particles. It can be effectively prevented.

In order to integrate the fine particles and the fine silica particles, it is preferable to apply pressure when mixing the fine particles and the fine silica particles. There is no particular restriction on the pressure application means, and any pressure application means may be used as long as it can achieve the above-mentioned integrated state. However, in the present invention, fine particles can be used in a dry state, and the cost is low. It is preferable to use means for applying mechanical strain force because it is economically advantageous.

Mechanical strain force is something that applies mechanical energy, mainly impact force, to cause a mechanochemical reaction. An example of a device that applies such a mechanical strain force is a powder processing device as described in Japanese Patent Application Laid-Open No. 63-42728, and specifically, a device for processing powder and granular material such as that described in Japanese Patent Application Laid-Open No. 63-42728. Mechanofusion system, hybridization system manufactured by Nara Kikai Seisakusho Co., Ltd., etc. are suitable.

The content of silica fine particles in the anti-aggregation agent thus obtained is preferably 40 to 95 wt%, more preferably 50 to 80 wt%.

When the content of silica fine particles is less than the above range, prevention of aggregation is insufficient, and when it exceeds the above range, image quality changes over time and cleaning defects occur.

There are no particular limitations on the chargeable toner particles contained in the electrophotographic toner of the present invention. However, for the above-mentioned reasons, the present invention exhibits particularly high effects when applied to l-component type developers.

There are no particular restrictions on the toner particles for the one-component developer used, but in order to obtain high-quality toner images with excellent image density, resolution, gradation, etc., it is recommended to use the following magnetic toner particles. preferable.

The volume average particle diameter is preferably 5 to 15 μm, particularly 6 to 9 μm. If this value is less than the above range, worsening of fog and poor cleaning will occur, which will also be disadvantageous in terms of cost. Moreover, when the above range is exceeded, problems arise such as deterioration of resolution and toner scattering.

The charging polarity of the magnetic toner particles may be appropriately selected depending on the material of the photoreceptor used, the developing process, etc.

The magnetic toner particles are composed of a resin containing magnetic powder and a colorant, and further contain a charge control agent, wax, resistance adjuster, etc., if necessary.

The resin used for the magnetic toner particles may be selected from known resins depending on the fixing method such as heating or pressure bonding (there are no particular restrictions, and examples include those listed below).

One or more types of resins such as olefin resins, acrylic resins, styrene copolymers, vinyl resins, polyamide resins, alkyd resins, epoxy resins, and polyester resins.

Among these resins, styrene-acrylic resins and polyester resins are preferred, and styrene-acrylic resins are particularly preferred.

The colorant may be selected depending on the purpose and is not particularly limited. Suitable colorants include, for example, the colorants described above.

The content of such a colorant is based on the resin 1 of the magnetic toner particles.
The amount is preferably about 1 to 10 parts by weight per 00 parts by weight.

Note that instead of using these colorants, magnetic powder described below may be used as the colorant.

A charge control agent is added as necessary to control charge polarity, charge amount, etc. In the present invention, a known appropriate charge control agent may be selected depending on the intended polarity, amount of charge, etc., and there are no particular limitations. Examples include metal complex salt azo dyes, nigrosine dyes, etc., which are selected depending on the required characteristics.

The content of such a charge control agent is preferably about 0.3 to 5 parts by weight based on 100 parts by weight of the resin of the magnetic toner particles.

Wax is added as a mold release agent as necessary to prevent offset. The wax used in the present invention is not particularly limited (although various known waxes such as polyethylene wax, polypropylene wax, silicone wax, etc. may be used, these are selected depending on the required characteristics. The content of the wax is 1 to 7 parts by weight per 100 parts by weight of the resin of the non-magnetic toner particles.
Preferably, it is about parts by weight.

There is no particular restriction on the magnetic powder contained in the magnetic toner particles.
Known magnetic powders such as magnetite and various ferrites may be used, but these are selected depending on the required characteristics.

Such magnetic powder may be contained in such a way that the magnetic properties required for the magnetic toner particles can be obtained, and although it varies depending on the type of magnetic powder, for example, 5 parts by weight of the resin of the magnetic toner particles is used. It is preferable to contain about 70 parts by weight.

In addition to these, the magnetic toner particles may also contain a resistance adjuster.

The magnetic toner particles may be manufactured by a conventional toner manufacturing method (for example, as described below).

Select the necessary additives from the above-mentioned colorants, charge control agents, waxes, magnetic powders, other additives, etc., melt and knead predetermined amounts of these and the resin, and after cooling, use a hammer mill, Coarsely grind using a cutter mill, etc. Then,
After finely pulverizing the particles using a jet mill, an ong mill, etc., the particles are classified to preferably fall within the volume average particle size range described above to obtain magnetic toner particles.

The magnetic toner particles thus obtained are mixed with the above-mentioned agglomeration preventive agent using a Henschel mixer, a grind mixer, etc., and the agglomeration preventive agent is attached to the surface of the magnetic toner particles, and then used as an electrophotographic toner. It will be done.

The content of the magnetic toner particles and anti-aggregation agent in the electrophotographic toner of the present invention is preferably 0.05 to 10 parts by weight, more preferably 0.1 parts by weight, based on 100 parts by weight of the magnetic toner particles. ~3 parts by weight. If the content of the anti-aggregation agent is less than the above range, prevention of aggregation will be insufficient, and if it exceeds the above range, changes in image quality over time will become a problem.

Such an electrophotographic toner of the present invention is used as a one-component developer as described in Japanese Patent Publications Nos. 41-9475 and 45-28.
No. 77, No. 54-3624, U.S. Patent No. 28
It can be suitably used in the jumping method, impression method, touchdown method, etc. described in Japanese Patent No. 95847, Japanese Patent No. 3152012, and the like. Furthermore, F
It can also be suitably used in the EED development method.

In addition, the electrophotographic toner of the present invention can also be mixed with carrier particles and used as a two-component developer.

When used as a two-component developer, non-magnetic toner particles are used as the charged toner particles.

As the non-magnetic toner particles, it is preferable to use particles having substantially the same composition and properties as the above-mentioned magnetic toner particles, except that they do not contain magnetic powder.

There are no particular restrictions on the carrier particles to be used (although device carrier particles composed of Fe, various ferrites, etc. may be used; however, it is preferable to use ferrite because charging can be easily controlled).

In the present invention, the volume average particle diameter of the carrier particles is preferably 30 to 120 μm, more preferably 35 to 55 μm.
It is μm.

In the electrophotographic developer of the present invention comprising such carrier particles and the above electrophotographic toner, the content of the electrophotographic toner is preferably 2 to 12 wt%.
, more preferably 8 to 10 wt%.

Such an electrophotographic developer of the present invention exhibits a predetermined effect when used in a dry developing method such as a magnetic brush developing method, a cascade method, a bristle brush method, or a powder cloud method.

<Example> Hereinafter, the present invention will be explained in further detail by giving specific examples of the present invention.

[Example 1] 49 parts by weight of styrene-acrylic resin (manufactured by Nippon Carbide Industries, Ltd.) 45 parts by weight of magnetite (TFP-2, manufactured by TDC Co., Ltd.) 3.5 parts by weight of polypropylene wax (Viscol 550P, manufactured by Mitsubishi Chemical Industries, Ltd.) After dissolving and kneading 0.5 parts by weight of carbon black (MA-100 manufactured by Mitsubishi Chemical Industries, Ltd.) and 2 parts by weight of a charge control agent (TRH manufactured by Hodogaya Chemical Co., Ltd.), the mixture was cooled and coarsely pulverized using a hammer mill. Next, it is finely pulverized with a jet mill and classified to a volume average particle size of 8.
Magnetic toner particles of 5 μm were prepared.

Next, the following anti-aggregation agent was prepared.

(Anti-agglomeration agent No. 1) 40 parts by weight of titanium oxide particles (P-25 manufactured by Nippon Aerosil Co., Ltd.) with a volume average particle size of 0.04 μm as fine particles, and silica particles with a volume average particle size of 0.02 μm as fine silica particles (
Using 60 parts by weight of RX-200 (manufactured by Nippon Aerosil Co., Ltd.),
These were mixed and integrated while applying mechanical strain as described above to form an anti-agglomeration agent. The mixing time was 5 minutes.

(Agglomeration inhibitor No. 2) 25 parts by weight of silica particles with a volume average particle size of 1.0 μm (Nip Seal 5S-60 manufactured by Nippon Silikani Gyo Co., Ltd.) as fine particles, silica particles with a volume average particle size of 0.01 μm as silica fine particles (Japan Using 75 parts by weight of R-972 (manufactured by Aerosil), these were mixed and integrated while applying the mechanical strain as described above to obtain an anti-agglomeration agent.

The mixing time was 7 minutes.

(Agglomeration inhibitor No. 3) Zinc stearate pulverized and classified into fine particles with a volume average particle diameter of 4 μm (Zinc Stearate 6 manufactured by Nitto Kasei Kogyo Co., Ltd.)
01) 20 parts by weight, volume average particle size 0 as silica fine particles
．． 02 μm silica particles (RX-2 manufactured by Nippon Aerosil Co., Ltd.)
00) were mixed and integrated while applying the mechanical strain as described above to obtain an anti-agglomeration agent. The mixing time was 5 minutes.

As a result of observing the cross sections of anti-aggregation agents Nos. 1 to 3 using a transmission electron microscope and a scanning electron microscope, it was confirmed that silica fine particles were embedded in the fine particle surfaces.

The above magnetic toner particles and anti-aggregation agents Nos. 1 to 3 were mixed in a Henschel mixer to obtain electrophotographic toners Nos. 1 to 3 of the present invention. As a result of observing these using a transmission electron microscope and a scanning electron microscope, it was confirmed that an anti-aggregation agent was attached to the surface of the magnetic toner particles. Note that magnetic toner particles are negatively charged,
The anti-agglomerating agent was also similarly charged.

Table 1 shows the content of the anti-aggregation agent per 100 stacked portions of magnetic toner particles in each toner.

In addition, for comparison, the above-mentioned agglomeration inhibitor No.

The fine particles used in Example 1 and the fine silica particles were mixed using a Henschel mixer to obtain anti-agglomeration agent No. 11. When this was observed using a transmission electron microscope and a scanning electron microscope, it was found that the silica fine particles were attached to the surface of the fine particles and were not embedded. This anti-aggregation agent No. 11 and the above magnetic toner were mixed using a Henschel mixer, and electrophotographic toner No.
, 11 were produced.

Furthermore, the volume average particle size is 1. Oum's silica fine particles (Nip Seal 5S-60, manufactured by Nippon Silikani Gyo Co., Ltd.) were used as an anti-aggregation agent, and the above magnetic toner particles were mixed with a Henschel mixer to produce electrophotographic toner No. 111.
was created.

The following fluidity test was conducted on these electrophotographic toners.

(Flowability test) Toner Log was vibrated on a 100 mesh sieve,
The fluidity of the toner was evaluated by measuring the amount of toner remaining on the sieve after seconds. A powder tester manufactured by Hosokawa Micron was used for the measurement.

Details of the evaluation shown in Table 1 are shown below.

○: 0.5g or less
Content test 1
1.

2 0.

3 　 　 　 　 0.

11 (Comparison) 1゜111 (Comparison) 0゜0 parts by weight 0 5 parts by weight 0 6 parts by weight ○ 0 parts by weight × 5 parts by weight × [Example 2] For various electrophotographic toners produced in Example 1 , the following continuous printing test was conducted.

(Continuous printing durability test) A continuous printing durability test pattern was prepared, and using this pattern, a 20,000-sheet continuous printing durability test was conducted using a commercially available electrophotographic laser beam printer (manufactured by Kyocera Corporation). . Note that the test was conducted under conditions of 30° C. and 75% RH.

As a result, it was found that for electrophotographic toner Nos. 1 to 3, there was little change in image quality over time even after the 20,000-sheet printing test, and the cleanability was also good. Further, no scratches were observed on the photoreceptor. Furthermore, there was very little scattering inside the machine, and no problems occurred when replenishing toner.

On the other hand, electrophotographic toner No. 11 and No.
No. 111 had problems with image quality deterioration such as layer disturbance and fog, poor cleaning, and photoreceptor deterioration.

[Example 3] Styrene-acrylic resin (manufactured by Mitsui Toatsu Chemical Co., Ltd.) 88 parts by weight of polypropylene wax (Viscol 550P, manufactured by Mitsubishi Chemical Industries, Ltd.) 3 parts by weight Carbon black (manufactured by Mitsubishi Chemical Industries, Ltd. MA-100) 7 parts by weight Charge After dissolving and mixing 2 parts by weight of a control agent (manufactured by Orient Chemical Co., Ltd.), the mixture was cooled and coarsely ground using a hammer mill. Next, it is finely pulverized with a jet mill and classified to a volume average particle size of 8.0.
Non-magnetic toner particles of μm size were produced.

The above non-magnetic toner particles and anti-aggregation agent No.

Mix each of 1 to 3 with a Henschel mixer,
Electrophotographic toners N004-6 of the present invention were obtained. As a result of observing these using a transmission electron microscope and a scanning electron microscope, it was confirmed that an anti-aggregation agent was attached to the surface of the nonmagnetic toner particles. Note that the nonmagnetic toner particles were negatively charged, and had the same chargeability as the anti-aggregation agent.

Table 2 shows the content of anti-aggregation agent per 100 parts by weight of non-magnetic toner particles in each toner.

In addition, for comparison, the above-mentioned agglomeration inhibitor No.

11 and the above-mentioned non-magnetic toner were mixed using a Henschel mixer to obtain toner No. 1 for electrophotography.

21 was produced.

Furthermore, using silica fine particles (Nip Seal 5S-60 manufactured by Nippon Silikani Gyo Co., Ltd.) with a volume average particle diameter of 1.0 μm as an anti-aggregation agent, this and the above-mentioned non-magnetic toner particles were mixed with a Henschel mixer to form electrophotographic toner No. , 21
1 was produced.

A fluidity test was conducted on these electrophotographic toners in the same manner as in Example 1.

The results are shown in Table 2.

table for electrophotography Toner No.

Anti-aggregation agent content fluidity test 4 1.0 parts by weight 0 5 0.5 parts by weight 0 6 0.6 parts by weight 0 21 (comparison) 1.0 parts by weight × 211 (comparison) 0.5 parts by weight × [Example 4] Various electrophotographic toners produced in Example 3 and Mg-Cu
-Zn ferrite carrier particles (TFC540 manufactured by TDC Co., Ltd.) were mixed to obtain two-component electrophotographic developers each containing 10 wt % of toner.

Using these two-component developers, a continuous copying test of 50,000 sheets was conducted using Dataquest charts, electrophotographic charts, and running charts as copy originals. In addition,
A commercially available electrophotographic copying machine (manufactured by Sanda Kogyo Co., Ltd.) was used as a copying machine.

As a result, the developers containing electrophotographic toners Nos. 4 to 6 had little change in image quality over time, had very little scattering in the machine, and did not cause any trouble during toner replenishment.

On the other hand, the developer containing electrophotographic toner No. 21 and the electrophotographic toner No.

The developer containing 211 has a large charge change over time (,
Image quality deteriorated, and there was also a large amount of flying debris inside the aircraft.

The effects of the present invention are clear from the above examples.

Even if it is, a high-quality toner image with good fluidity and excellent resolution, gradation, etc. can be obtained. In-flight scattering is also extremely low.

<Effect of the invention>

Claims (1)

[Scope of Claims] (1) An anti-aggregation agent in which fine particles having a volume average particle size of 0.01 to 5 μm and silica fine particles having a smaller volume average particle size than these fine particles are fixed and integrated, and a charged toner. An electrophotographic toner characterized by containing particles. (2) The electrophotographic toner according to claim 1, wherein the silica fine particles have a volume average particle diameter of 0.5 μm or less. (3) The anti-aggregation agent contains 40 to 95 wt of silica fine particles.
% of the electrophotographic toner according to claim 1 or 2. (4) 0.05 to 10 parts by weight of the anti-aggregation agent is contained with respect to 100 parts by weight of the chargeable toner particles.
3. The electrophotographic toner according to any one of 3 to 3. (5) the charged toner particles are magnetic toner particles;
5. The electrophotographic toner according to claim 1, which is used as a one-component electrophotographic developer. (6) An electrophotographic developer comprising the electrophotographic toner according to any one of claims 1 to 4 and carrier particles.