JP2002236391A - Toner and image forming device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress filming on a toner contact member such as a toner carrier, a toner control member and a latent image carrier, and also, to improve the uniformity of electrification. SOLUTION: As for the toner T, the absolute deviation of the synchronizing distribution of silica being an external additive 10 to the base particle 18 is set lower than the absolute deviation of the synchronizing distribution of titanium oxide being the external additive 19 to the base particle 18. Then, the filming on the toner contact member such as the toner carrier, the toner control member and the latent image carrier, is effectively suppressed by silica for suppressing the occurrence of filming, and also, titanium oxide for adjusting the electrification becomes more active than silica, then, the toner is more uniformly electrified by the titanium oxide. The filming on the toner contact member is prevented in such the way, and also, the uniformity in electrifying the toner is improved, then, good image quality is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of toner for developing an electrostatic latent image on a latent image carrier, comprising a large number of base particles and a large number of particles of an external additive such as silica. It belongs to the technical field of an image forming apparatus that forms an image using this toner, and in particular, suppresses toner filming to a toner contact member that comes into contact with the toner, such as a latent image carrier, a toner carrier, and a toner regulating member. In addition, the present invention belongs to the technical field of a toner capable of favorably performing low-temperature fixing and an image forming apparatus using the toner.

[0002]

2. Description of the Related Art In an image forming apparatus using toner, an electrostatic latent image on a latent image carrier is developed with toner, and the developed image is transferred to a transfer material such as paper. Then, a transferred image of the exposed electrostatic latent image is formed on the latent image carrier, and then the transferred image is fixed to form an image.

[0003]

2. Description of the Related Art As an example of such a conventional image forming apparatus, there is a full-color intermediate transfer type image forming apparatus as shown in FIG. In the image forming apparatus 1, an image is exposed as an electrostatic latent image on a photoconductor 2 as a latent image carrier, and the electrostatic latent image on the photoconductor 2 is yellow,
The magenta, cyan, and black non-magnetic one-component developing units 3, 4, 5, and 6 are sequentially developed (the order of each color is arbitrary) to be visualized. After the color transfer is performed on the intermediate transfer belt 7a of the transfer body 7 and the primary transfer is performed, the color is secondarily transferred to a transfer material 9 such as paper on a secondary transfer roller 8a of a transfer device 8, and then heated by a fixing device 10. By fixing, a desired image can be obtained on the transfer material 9.

Each of the non-magnetic one-component developing units 3, 4, 5, and 6 has substantially the same configuration, and is a contact developing type developing unit in which the conductive developing roller 16 and the photosensitive member 2 are in contact with each other. As shown in FIG. 2A, each of the developing devices 3, 4, 5, and 6 transfers the toner T in the toner storage unit 13 to the toner conveying unit 1.
At 4, the toner T is conveyed to a toner supply roller 15 serving as a toner supply unit, and the toner T is supplied to the developing roller 16 by the toner supply roller 15 and carried on the surface of the developing roller 16. When the developing voltage of the AC bias is applied to the developing roller 16 and the developing roller 16 is rotated at a high speed, the toner T on the developing roller 16 is a toner regulating member pressed against the surface of the developing roller 16. The toner is regulated to a uniform thin layer by a certain toner regulating blade 17 and is uniformly charged. Then, the developing roller 1
The toner T on 6 is uniformly conveyed toward the photoconductor 2 that is in contact with the developing roller 16. Then, the toner T on the developing roller 16 is applied with the developing voltage applied to the developing roller 16.
Are moved toward the photoconductor 2, the electrostatic latent image on the photoconductor 2 is developed with the toner T.

A non-magnetic one-component developing method using the conductive developing roller 16 includes a non-contact developing method in which the developing roller 16 and the photosensitive member 2 are separated from each other. In the non-contact developing method, a developing voltage is applied to the developing roller 16, and the toner T particles on the developing roller 16 are applied to the photosensitive member 2 by the developing voltage.
The electrostatic latent image on the photoreceptor 2 is jumped and developed with the toner T by the jumping movement toward.

[0006] Such a conventional non-magnetic one-component developing apparatus 1
In this case, the toner T may be fused on a toner contact member such as the developing roller 16, the toner regulating blade 17, and the photoconductor 2 which comes into contact with the toner to cause filming. Therefore, conveyance failure of the toner T by the developing roller 16, regulation failure of the toner regulating blade 17, and development failure or the like occurs in the photosensitive member 2, there is a problem that image quality deterioration occurs.

Further, if the toner T particles are not charged uniformly, defective conveyance of the toner T by the developing roller 16 and defective development on the photosensitive member 2 occur, and the same problem as described above occurs. Would.

Therefore, conventionally, as shown in FIG. 2B, these problems are addressed by coating a base particle 18 made of a resin of the toner T with an external additive 19. In this case, the diameter of the external additive 19 is set to be extremely smaller than the diameter of the base particles 18. Further, in the heat fixing by the fixing device 10, in order to enable low-temperature fixing, conventionally, the toner T uses the base particles 18 having a relatively soft and low softening point even at normal temperature. In order to prevent filming from occurring, at least silica is used as the external additive 19, and at least titanium oxide for adjusting the chargeability is used as the external additive 19 in order to perform uniform charging. . In particular, most of the conventional color toners combine such silica and titanium.

[0009]

By the way, the toner T described above is prepared by mixing the base particles 18 and particles of the external additive 19 (hereinafter, also simply referred to as the external additive 19) so that the external additive is added to the base particles 18. Although the base particles 18 and the external additives 19 are actually adhered to each other as shown in FIG. 2B (reference numeral 18 denotes the base particles themselves and the external additives in the same manner as described above). No. 19 is used for both the external additive itself and the external additive adhered to the base particles, as described above, and no external additive 19 is attached. The free base particles 18 'and the free external additives 19' not attached to the base particles 18 are mixed.

However, if the titanium oxide is more strongly adhered to the base particles 18 than the silica, the toner is not uniformly charged, and the uniformity of the charge is deteriorated. This is considered to be due to the fact that the titanium oxide is more difficult to move than the silica, so that the charging uniformity is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to suppress filming of toner contact members such as a toner carrier, a toner regulating member, and a latent image carrier. Another object of the present invention is to provide a toner capable of improving charging uniformity and an image forming apparatus using the toner.

[0012]

According to a first aspect of the present invention, there is provided a toner having at least a large number of base particles and a large number of particles of an external additive. It includes at least each particle of silica and titanium oxide, wherein the absolute deviation of the synchronous distribution of the silica with respect to the base particles is set to be smaller than the absolute deviation of the synchronous distribution of the titanium oxide with respect to the base particles. I have.

[0013] The image forming apparatus according to the second aspect of the present invention includes:
A latent image carrier on which an electrostatic latent image is formed, and a toner carrier that transports toner to develop an electrostatic latent image on the latent image carrier;
And a developing device having a toner regulating member for regulating at least the toner conveyed toward the latent image carrier by the toner carrier, wherein the toner is the toner according to claim 1. .

[0014]

In the toner of the present invention thus constituted, the absolute deviation of the synchronous distribution of silica with respect to the base particles is set smaller than the absolute deviation of the synchronous distribution of titanium oxide with respect to the base particles. Therefore, filming of the toner contact member such as the toner carrier, the toner regulating member, and the latent image carrier is effectively suppressed by the silica that suppresses the occurrence of filming. In addition, since the dispersion of the titanium oxide for adjusting the charge is larger than the dispersion of the silica and the state is easy to move, the toner is more uniformly charged by the titanium oxide. Thus, in the toner of the present invention, the filming of the toner contact member is prevented, and the uniformity of toner charging is improved.

On the other hand, in the image forming apparatus of the present invention,
By using this toner, filming of the toner contact member in the image forming apparatus is prevented, and charging of the toner is performed more uniformly, so that good image quality can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. An image forming apparatus according to an embodiment of the present invention has the same configuration as the image forming apparatus 1 shown in FIGS. 1 and 2A, respectively. Therefore, the operation of the image forming apparatus 1 of this example at the time of image formation is the same as that of the above-described conventional example.

The toner T of the present invention used in the image forming apparatus 1 of this embodiment comprises at least a large number of base particles 18 and external additives 19. The mother particles 18 are made of a resin having a low softening point which is soft at room temperature.
Uses particles of at least silica and titanium oxide in combination. The absolute deviation of the synchronous distribution of silica with respect to the base particles 18 is set smaller than the absolute deviation of the synchronous distribution of titanium oxide with respect to the base particles. Here, the synchronization of the external additive 19 with the base particle 18 means that the external additive 19 is attached to the base particle 18 as described later. The synchronous distribution and the absolute deviation of the external additive with respect to the base particles can be obtained by analyzing the adhesion state between the base particles 18 and the external additive 19 of the toner. I have. The image forming apparatus 1 of this example employs, for example, the following particle analyzer method.

That is, in the image forming apparatus 1 of this example,
As a method of analyzing the adhesion state between the base particles 18 of the toner T and the external additive 19, an annual meeting of the Electrophotographic Society of Japan (total 95
Times), "Japan Hardcopy '97", Collection of Papers, "New Evaluation Method of External Addition-Toner Analysis by Particle Analyzer-", Toshiyuki Suzuki, Toshio Takahara, Electrophotographic Society, 199
The toner analysis method (PT1000) disclosed on July 9 to 11, 2007 is employed.

In this toner analysis method, particles of toner T formed by adhering an external additive 19 made of silica (SiO ₂ ) to the surface of base particles 18 made of resin (C) are introduced into plasma. Excites the toner T particles,
This is a method of performing elemental analysis by obtaining emission spectra as shown in FIGS. 3A and 3B accompanying this excitation.

In FIG. 3, the horizontal axis of the emission spectrum indicates the time axis. First, as shown in FIG. 3A, when the toner T particles obtained by adhering the external additive (SiO ₂ ) to the resin base particles (C) of the toner T are introduced into the plasma, the mother particles (C) and the outer particles are formed. The additive (SiO ₂ ) emits light. At this time,
Since the base particles (C) and the external additive (SiO ₂ ) are simultaneously introduced into the plasma, the base particles (C) and the external additive (SiO ₂ ) are introduced.
₂ ) and emit light simultaneously. Thus, when the base particles (C) and the external additive (SiO ₂ ) emit light simultaneously, it is said that the base particles (C) and the external additive (SiO ₂ ) are synchronized. In other words, the state where the base particles (C) and the external additive (SiO ₂ ) are synchronized indicates a state where the external additive (SiO ₂ ) is attached to the base particles (C).

In addition, as shown in FIG.
Base particles (C) or base particles (C) to which iO ₂ ) does not adhere.
When the external additive (SiO ₂ ) released from the gas is introduced into the plasma, the mother particles (C) and the external additive (S
iO ₂ ) emits light, but at this time, the base particles (C) and the external additive (SiO ₂ ) are introduced into the plasma at different times.
Light emission occurs at a time different from ₂ ) (for example, when the base particles are introduced into the plasma before the external additives, the base particles emit light first, and thereafter the external additives emit light after a delay).

As described above, the base particles (C) and the external additives (Si
O ₂ ) emits light at different times from each other,
It is said that the base particles (C) and the external additive (SiO ₂ ) are not synchronized (that is, asynchronous). In other words, the state in which the base particles (C) and the external additive (SiO ₂ ) are asynchronous is as follows:
This means that the external additive (SiO ₂ ) does not adhere to the base particles (C), and the base particles and the external additives are free base particles and free external additives, respectively.

Further, in FIGS. 3A and 3B, the height of the light emission signal indicates the intensity of the light emission, and the intensity of the light emission is not the size or shape of the particle but the intensity within the particle. It is proportional to the number of atoms of the element (C, SiO ₂ ) contained. Then, in order to express the emission intensity of the element as the size of the particles, when light emission of the base particles (C) and the external additive (SiO ₂ ) is obtained as shown in FIG. 4, these base particles (C) And spherical particles made only of the external additive (SiO ₂ ), the base particles (C) and the external additive (Si
O ₂ ). The true sphere particles at this time are called equivalent particles, and the particle size is called an equivalent particle size. Since the external additive is very small, the particles cannot be detected one by one. Therefore, the emission signal of the detected external additive is added to be converted into one equivalent particle and analyzed. . The equivalent particle size of the equivalent particles obtained by the respective emission spectra of the base particles and the external additive is calculated by
Is plotted for each particle, an equivalent particle size distribution diagram of the toner particles as shown in FIG. 5 is obtained.

In FIG. 5, the horizontal axis represents the equivalent of the base particle (C).
The vertical axis represents the external additive (SiO 2). _TwoTable) Equivalent particle size
are doing. The equivalent particles on the horizontal axis represent the external additive (Si
O_Two) Represents an asynchronous parent particle (C) without attachment
ing. In that case, the external additive less than the specified external additive concentration
Are also shown on this horizontal axis, and the non-
Synchronous mother particles (C). Also, the equivalent on the vertical axis
The particles are made of an asynchronous external additive (S) released from the base particles (C).
iO_Two). In addition, not on the horizontal and vertical axes
The equivalent particles are obtained by adding an external additive (SiO 2) to the base particles (C)._Two) Adheres
Represents the synchronized toner T. Like this
The external additive (Si) to the base particles (C) of the toner T
O_Two) Is analyzed.

Furthermore, by using an equivalent particle size distribution diagram of the toner particles shown in FIG. 5, as shown in FIG. 6, adhesion state of carbon in the mother particles of the toner T (C) and the external additive (SiO ₂₎ the utilizes one approximate line α passing through the origin was obtained by using the least squares method. The slope (equivalent particle size of external additive / equivalent particle size of base particle) θ of this approximate straight line α is the concentration of the external additive (SiO ₂ ) adhering (synchronizing) to the base particle (C). Represents. That is, the smaller the inclination θ, the smaller the amount of the synchronized external additive (SiO ₂ ), and the larger the inclination θ, the larger the synchronized external additive (SiO ₂ ).

In the present invention, an equivalent particle size distribution map of the toner particles showing the synchronous distribution of silica with respect to the base particles 18 and a straight line α similar to the equivalent particle size distribution diagram of the toner particles shown in FIG. From the dispersion state of the synchronous toner, that is, the obtained straight line α, the absolute deviation of silica representing the variation of the silica synchronous toner is determined. Similarly, an equivalent particle size distribution diagram of toner particles showing the synchronous distribution of titanium oxide with respect to the base particles 18 and a straight line α are obtained, and the dispersion state of the titanium oxide synchronous toner, that is, the variation of the titanium oxide synchronized toner is shown from the obtained straight line α. The absolute deviation of titanium oxide is determined.

In the present invention, the toner analysis is performed using the equivalent particle size distribution diagram of toner particles and the straight line α shown in FIG. 6, but the toner analysis method is other than the above-described particle analyzer method. Analytical methods can also be used. However, it is preferable to use the particle analyzer method because the toner analysis can be performed more accurately and more easily.

Further, the flow softening point of the base particles 18 of the toner T is preferably 100 ° C. to 120 ° C. This is because when the flow softening point of the base particles 18 becomes lower than 100 ° C., the toner T gradually fuses to the toner contact members such as the developing roller 16, the toner regulating blade 17, and the photoreceptor 2. Although this does not hinder practical use, it is not preferable that the size be further reduced. Also,
When the flow softening point of the base particles 18 is higher than 120 ° C., the low-temperature fixing becomes gradually poor. However, even if the flow softening point is increased to some extent, there is no problem in practical use. Absent.

Incidentally, the toner T used in the image forming apparatus of this embodiment may be either negative polarity or positive polarity toner. At least a coloring agent, a charge controlling agent, and other resins are added to the base particles 18, and a dispersant, a release agent (WAX), a magnetic material, other additives, and the like are also appropriately added.

As the base particles 18, a base particle material having a relatively low softening point at room temperature is used, and polystyrene and a copolymer such as a hydrogenated styrene resin, a styrene / isobutylene copolymer, an ABS resin, an ASA resin, AS resin, AAS resin, ACS resin, AES resin, styrene
P-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene cross-linked polymer, styrene
Butadiene / chlorinated paraffin copolymer, styrene / allyl / alcohol copolymer, styrene / butadiene rubber emulsion, styrene / maleic ester copolymer, styrene / isobutylene copolymer, styrene / maleic anhydride copolymer, acrylate Resin or methacrylate resin and its copolymer, styrene / acrylic resin and its copolymer such as styrene / acrylic copolymer, styrene / diethylamino / ethyl methacrylate copolymer, styrene / butadiene / acrylic acid Ester copolymer, styrene / methyl methacrylate copolymer, styrene / n-butyl methacrylate copolymer, styrene / methyl methacrylate / n-
Butyl acrylate copolymer, styrene / methyl methacrylate / butyl acrylate / N- (ethoxymethyl) acrylamide copolymer, styrene / glycidyl methacrylate copolymer, styrene / butadiene / dimethyl / aminoethyl methacrylate copolymer, styrene・ Acrylic acid ester ・ Maleic acid ester copolymer, Styrene ・ Methyl methacrylate ・ Acrylic acid 2-
Ethylhexyl copolymer, styrene / n-butyl acrylate / ethyl glycol methacrylate copolymer, styrene / n-butyl methacrylate / acrylic acid copolymer, styrene / n-butyl methacrylate / maleic anhydride copolymer, styrene Butyl acrylate, isobutyl maleic acid half ester, divinylbenzene copolymer, polyester and its copolymer, polyethylene and its copolymer, epoxy resin, silicone resin,
One or a mixture of two or more of polypropylene and its copolymer, a fluorine resin, a polyamide resin, a polyvinyl alcohol resin, a polyurethane resin, and a polyvinyl butyral resin can be used.

Examples of the coloring agent include carbon black, spirit black, nigrosine, rhodamine, triaminotriphenylmethane, cation, dioxazine, copper phthalocyanine, berylen, azo, gold-containing azo pigment, azochrome complex, carmine, benzidine,
Solar Pure Yellow 8G, quinacridone, polytungstophosphoric acid, induslen blue, a sulfonamide derivative and the like can be used.

As the charge control agent, an electron-accepting organic complex, chlorinated polyester, nitrophenic acid, quaternary ammonium salt, pyridinyl salt and the like can be used. As the release agent, polypropylene wax, polyethylene wax, ester wax, or the like can be used. As a dispersant, metal soap, polyethylene glycol, and the like can be used. As other additives, zinc stearate, zinc oxide, cerium oxide and the like can be used.

[0033] As the magnetic material, Fe, Co, Ni, C
Metal powder such as r, Mn, Zn, etc., Fe ₃ O ₄ , Fe ₂ O ₃ , Cr
_An alloy or the like which exhibits ferromagnetism by heat treatment such as a metal oxide such as ₂ O ₃ or ferrite, or an alloy containing manganese and an acid can be used, and a preliminary treatment such as a coupling agent may be performed in advance. And, using these, a general kneading and pulverizing method,
The mother particles 18 are prepared by a spray-dry method, a polymerization method, or the like.

Examples of the external additive 19 include, in addition to silica and titanium oxide, fine particles of metal oxides such as aluminum oxide, strontium titanate, cerium oxide, magnesium oxide and chromium oxide, and fine particles of nitride such as silicon nitride. A mixture of at least one kind of fine particles of a carbide such as silicon carbide, fine particles of a metal salt such as calcium sulfate, barium sulfate, and calcium carbonate; inorganic fine particles such as a composite thereof; and organic fine particles such as an acrylic fine particle. can do. In addition, as these surface treatment agents, in addition to HMDS, a silane coupling agent, a titanate coupling agent, a fluorine-containing silane coupling agent, a silicone oil, or the like can be used. The particle size of the external additive 19 is preferably 0.001 to 1 μm from the viewpoint of transportability and chargeability. The base particles 18 and the external additives 19 are dry-mixed with a high-speed fluid mixer such as a Henschel mixer or a Papen-Meyer or a mixer such as a mechanochemical method and adhered.

According to the thus configured toner T of this example, the absolute deviation of the synchronous distribution of silica with respect to the base particles 18 is set smaller than the absolute deviation of the synchronous distribution of titanium oxide with respect to the base particles 18. By using silica for suppressing the occurrence of filming, filming of the toner contact member such as the developing roller 16, the toner regulating blade 17, and the photoconductor 2 can be effectively suppressed, and the titanium oxide for performing charge adjustment Is larger than the dispersion of silica, and the state of movement is easy. Therefore, the titanium oxide can more uniformly charge the toner T. Thus, according to the toner T of this example, it is possible to prevent filming of the toner contact member and to improve the uniformity of toner charging.

On the other hand, according to the image forming apparatus 1 of this example,
By using the toner T of this example, the image forming apparatus 1
Since the filming of the toner contact member inside can be prevented and the toner can be charged more uniformly, good image quality can be obtained.

Actually, an experiment was conducted to measure the chargeability of each of the toners of Examples 1 and 2 of the present invention and each of the toners of Comparative Examples 1 and 2 for comparison with Examples 1 and 2. Table 1 shows the toner used and the external addition processing conditions in this measurement experiment, and the experimental results. The method of evaluating the experimental results was to evaluate the toner charge amount and toner fog after printing 1K (1K = 1000) sheets.

[0038]

[Table 1]

As shown in Table 1, in each of the toners of Examples 1 and 2 belonging to the present invention and Comparative Examples 1 and 2 not belonging to the present invention, the used base particles 18 are pulverized toners.

In any toner, first, titanium oxide and base particles are externally added as a first step, and then the silica particles and the first step are externally added as a second step. It is attached. In this case, the external addition conditions in the first stage are as follows. In any toner, titanium oxide (TiO ₂ ) is used as the external additive 19, and this titanium oxide is NKT90.
(Made by Nippon Aerosil). Also, in any of the toners, the device used for the external addition process of the base particles 18 and titanium oxide is Henschel 20C (manufactured by Mitsui Mining), and the number of rotations of the device used in the external addition process is 2850 rpm. The amount is 0.5 parts by weight. The external addition processing time was 2 minutes in Example 1, 3 minutes in Example 2, 4 minutes in Comparative Example 1, and 3 minutes in Comparative Example 2.

On the other hand, as for the external addition conditions in the second stage, silica (SiO ₂ ) is used as the external additive 19 for all toners, and this silica is TG810G (manufactured by Cabot). In each case, Henschel 20C (manufactured by Mitsui Mining Co., Ltd.) was used as an apparatus for externally adding titanium oxide to base particles 18 and silica, and the number of rotations of the apparatus used in the external addition processing was changed. Is 2850 rpm,
The external addition processing amount is 1.0 part by weight. Further, external addition treatment time is Example 1 4 min, Example 2 is 4 minutes, Comparative Example 1 is 2 minutes, Comparative Example 2 is 3 minutes.

[0042] Furthermore, the silica absolute deviation, Example 1 is 0.
08, Example 2 was 0.10, and Comparative Example 1 was 0.1.
17 and Comparative Example 2 was 0.15, and the absolute deviation of titanium oxide was 0.16 in Example 1, 0.12 in Example 2, and 0.11 in Comparative Example 1. And Comparative Example 2 is 0.12. Further, the initial charge amounts were 15.6 μc / g in Example 1, 14.2 μc / g in Example 2, 14.0 μc / g in Comparative Example 1, and 15.4 μc / g in Comparative Example 2. / G.

As is clear from Table 1, with the toner T of Example 1, the toner charge after printing 1K sheets is 15.4 μc.
/ G, which is slightly reduced from the initial charge amount, but hardly changes, and a good result of having a stable chargeability is obtained. In the toner T of Example 2, the toner after printing 1K sheets The charge amount was 13.6 μc / g, similar to Example 1, although slightly lower than the initial charge amount, there was almost no change, and a favorable result of having stable chargeability was obtained.

On the other hand, in the toner T of Comparative Example 1,
The toner charge amount after printing 1K sheets is 8.9 μc / g,
There is a relatively large change that is considerably smaller than the initial charge amount, and unfavorable results are obtained because the chargeability is not stable,
Also, in the toner T of Comparative Example 2, the toner charge amount after printing 1K sheets is 11.2 μc / g, which is considerably smaller than the initial charge amount as in Comparative Example 1, and has a relatively large change. Unsatisfactory results were obtained because the properties were not stable.

Further, with the toner T of Example 1, the toner fog after printing 1K sheets was 6.5 g / 1K, which was relatively small and good results were obtained. The toner fog after printing on the sheet was 5.4 g / 1K, and similarly, a relatively small and good result was obtained.

The contrast, in the toner T of Comparative Example 1,
The toner fog after printing 1K sheets was 16.7 g / 1K, which was relatively large and an unfavorable result was obtained. In the toner T of Comparative Example 2, the toner fog after printing 1K sheets was 9.6 g / 1K. Yes, relatively large and undesirable results were obtained.

Therefore, by setting the absolute deviation of the synchronous distribution of silica with respect to the base particles smaller than the absolute deviation of the synchronous distribution of titanium oxide with respect to the base particles,
6, it was found that the charging uniformity can be improved while suppressing the filming of the toner contact member such as the toner regulating blade 17 and the photoconductor 2.

[0048] Incidentally, the base particles used in the above experiments is a pulverized toner produced by pulverization method, the present invention can be applied to the base particles produced by other manufacturing methods.
Further, the toner and the image forming apparatus of the present invention are not limited to the above-described examples, and any toner T having at least base particles and an external additive and any image forming apparatus using the toner T may be used. The present invention can be applied to a toner and an image forming apparatus.

[0049]

As is apparent from the above description, according to the toner of the present invention, the absolute deviation of the synchronous distribution of silica with respect to the base particles is set smaller than the absolute deviation of the synchronous distribution of titanium oxide with respect to the base particles. Therefore, the filming of the toner contact member such as the toner carrier, the toner regulating member, and the latent image carrier can be effectively suppressed by the silica that suppresses the occurrence of the filming, and the charge adjustment is performed. Since the dispersion of the titanium oxide is larger than the dispersion of the silica and the state is easy to move, the toner can be more uniformly charged by the titanium oxide. As described above, according to the toner of the present invention, it is possible to prevent filming of the toner contact member and to improve the uniformity of toner charging.

On the other hand, according to the image forming apparatus of the present invention, by using the toner of the present invention, filming of the toner contact member in the image forming apparatus can be prevented, and the toner can be charged more uniformly. As a result, good image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a full-color intermediate transfer type image forming apparatus which is an example of a conventional image forming apparatus used in an example of an embodiment of the image forming apparatus according to the present invention.

FIGS. 2A and 2B schematically show an example of a conventional developing device used in the image forming apparatus of the example shown in FIG. 1, wherein FIG. 2A is a cross-sectional view thereof, and FIG. FIG. 4 is a diagram illustrating toner particles.

FIG. 3 is a view for explaining an example of a conventional toner analysis method for use in analyzing the state of adhesion between toner base particles and external additives.

FIG. 4 is a diagram illustrating equivalent particles and equivalent particle sizes used in the toner analysis method shown in FIG.

5 is a diagram showing an analysis result by the toner analysis method shown in FIG.

6 is a diagram showing, based on the analysis result shown in FIG. 5, the state of adhesion between the mother particles of the toner and the external additive by using a single approximate straight line α passing through the origin using the least squares method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Latent image carrier (photoreceptor), 3, 4,
5, 6 developing device, 7 intermediate transfer member, 16 toner carrier (developing roller), 8 transfer device, 9 transfer material, 10 fixing device, 17 toner regulating member (toner regulating blade), 1
8: Base particles, 19: External additive, 18 ': Free base particles, 1
9 ': free external additive, T: toner

Claims (2)

[Claims] 1. A toner having at least a large number of base particles and a large number of particles of an external additive, wherein the external additive includes at least silica and titanium oxide particles, and synchronization of the silica with the base particles. The toner according to claim 1, wherein an absolute deviation of the distribution is set to be smaller than an absolute deviation of a synchronous distribution of the titanium oxide with respect to the base particles. 2. A latent image carrier on which an electrostatic latent image is formed; a toner carrier for conveying toner to develop an electrostatic latent image on the latent image carrier; at least a developing device having a toner regulating member at least restricting the toner conveyed toward the image bearing member, an image forming apparatus wherein the toner is a toner according to claim 1 or 2 wherein.