JPH06102705A - Nonmagnetic one-component developing device - Google Patents

Abstract

PURPOSE:To maintain a good state without deterioration of electrification property and fluidity of a toner even when the deposition state of an external additive gradualy changes, by using a polyester-base negative toner consisting of polyester binder resin and a specified boron compd. as a charge control agent incorporated into the binder resin. CONSTITUTION:As for the nonmagnetic one-component toner, a polyester-base negative toner consisting of a polyester binder resin and a baron compd. expressed by formula as a charge control agent incorporated into the polyester binder resin is used. The amt. of the charge control agent is 0.5-3.0wt.%. This nonmagnetic one-component toner is obtd. by the following method. The boron compd. expressed by the formula in a specified proportion with a coloring agent is added an kneaded with a polyester resin consisting of, for example, bis-phenol A-ethylene oxide-added compd./cyclohexane dimethanol/terephthalic acid. Then the kneaded material is pulverized and classified into toner particles of 5-20mum average particle size. Then a fluidizing agent or transfer assistant is added as an external additive.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic developing apparatus, and more specifically, a non-magnetic single component that visualizes an electrostatic latent image formed on a latent image carrier with a non-magnetic single-component toner. The present invention relates to a developing device.

[0002]

2. Description of the Related Art As disclosed in JP-A-47-13088, JP-A-49-104639 and JP-A-53-30339, a non-magnetic one-component toner is latent imaged by a toner carrier. Area close to the holder (Development area)
There is known a non-magnetic one-component toner developing device which feeds the toner to the toner and develops the electrostatic latent image on the latent image carrier with the toner. That is, according to this type of developing device, generally, the non-magnetic one-component toner supplied to the toner carrier by a supply roll or the like is in pressure contact with the surface of the toner carrier, which is a regulating member (specifically, an EPDM rubber blade). , A silicon rubber blade, a stainless steel blade, etc.) are formed in a thin layer and are charged by being given a positive charge or a negative charge, and the charged toner adheres to the toner carrier by electrostatic attraction, etc. Development is performed by coupling the electrostatic latent image on the latent image carrier with electrostatic attraction in an electric field generated by the developing bias voltage applied to the toner carrier. Therefore, in such a non-magnetic one-component toner developing device, it is important that the toner is sufficiently charged by the regulating member, and the toner charging property is usually greatly influenced by the pressure contact force of the regulating member. That is, the chargeability of the non-magnetic one-component toner in this developing system is generally determined by the material of each functional component (toner carrier, regulating member, toner supply member, etc.) in the developing device and various factors of the toner material. Among them, after all,
The frictional condition when the toner passes through the regulation member is the most dominant factor. This is because the toner charging phenomenon is
This is because the toner is almost triboelectrically charged when passing through the regulating member. Due to such circumstances, the pressure contact force of the regulating member is large after all, and the charging property of the toner is affected.

Therefore, in this type of developing device,
Although a large pressure contact force of the regulating member is required to obtain a sufficient toner charge amount by the regulating member,
On the other hand, there is a problem that a load (stress) on the toner increases due to the high pressure contact force, and as a result, the chargeability of the toner deteriorates with time. It is considered that the deterioration of the charging property of the toner is due to the following reasons. That is, in the non-magnetic one-component toner charged by the regulating member, an external additive such as hydrophobic silica (SiO ₂ ) or titanium oxide (TiO ₂ ) is used to control the chargeability and fluidity of the toner. However, the external additive is gradually buried inside the toner particles due to pressure contact by the regulating member and its adhesion state changes, whereby the external additives adhere to the surface of the particles in the initial state. It is considered that the total amount of the external additive is reduced, and as a result, the charging effect of the external additive is gradually reduced. Further, this phenomenon of deterioration of the charging property tends to occur relatively remarkably particularly in the toner existing in the portion which becomes the non-developing portion of the toner carrier. This is because, on the surface of the toner carrier, a developing portion area where the electrostatic latent image is developed and the toner is consumed and a non-developing portion area where the toner is not consumed are generated according to the developed image, and the developing portion is in the developing portion. After the completion of the development process, new toner is supplied, and a layer is formed and charged by the regulating member for the new toner, but in one non-development area, the thin layer of toner formed on the toner carrier is regulated again. Will pass through the member,
This is because a thin layer of the same toner passes through the regulating member many times while receiving little new toner supply in the portion where the non-image portion continues for a while. Such deterioration of the chargeability of the toner not only causes a problem that the toner adheres to areas other than the image area of the latent image carrier, so-called non-image area fog occurs and the image quality is deteriorated, and also the toner carrier does not The toner may fall off, or the toner that falls off and floats may cause contamination inside the machine, which is a serious problem.

Therefore, the present applicant has proposed the following methods (1) to (5) in order to solve such problems. Means for reducing the stress on the toner by making the pressure contact force of the regulating blade extremely small (Japanese Patent Application No. 2-248).
No. 803). All toner layers on the toner carrier are once collected in the hopper after passing through the developing area, and new toner is constantly supplied to the carrier so that the same toner is not continuously pressed by the regulating member. Means configured as described above (Japanese Patent Application No. 3-185239). As a charge control agent, the following general formula typified by sodium tetraphenylboron, etc.

[0005]

[Chemical 2]

The toner resin contains a compound represented by the formula (wherein R represents a hydrogen atom, a halogen atom, an alkyl group, a benzyl group or an aryl group, and M represents a cationic atom or a molecule). Means for improving the charging property of the above (JP-A-63-180968).

However, in the above method, the layer regulation by the regulating member cannot be reliably performed due to the variation in the amount of toner supplied to the toner carrier by the supply roll.
As a result, it is not possible to always perform development with a constant toner layer, and as a result, the image density varies and the image quality becomes unstable. Further, the above method cannot be an essential solution because the toner once returned to the hopper is also circulated and used for a long time, and the load is repeatedly applied by the regulating member. It was Further, although the above method is effective in improving the chargeability of the toner when the above compound is contained in a styrene-based or acrylic-based toner resin, it is particularly a negatively chargeable toner resin. When it was contained in the polyester resin, a sufficient improvement effect was not obtained, and the toner chargeability deteriorated with time.

In addition, in this type of non-magnetic one-component developing device, the fluidity of the toner subjected to the load by the regulating member gradually deteriorates, which causes variations in the amount of toner supplied to the toner carrier. There is a problem such as missing of an image in the formation of a solid black image.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and when a negatively chargeable polyester-based toner is used as the toner, it is subjected to a load by the regulating member and the external additive. Provided is a non-magnetic one-component developing device in which the chargeability and the fluidity of the toner are not deteriorated and are maintained well even if the adhesion state of the toner is changed, and thereby stable and favorable image formation is realized. The purpose is to do.

[0010]

That is, in the non-magnetic one-component developing device of the present invention, the non-magnetic one-component toner supplied onto the toner carrier is formed into a thin layer by a regulating member that is pressed against the surface of the toner carrier. In the non-magnetic one-component developing device that develops the electrostatic latent image formed on the latent image holding member with the charged toner, the charge control is performed on the polyester binder resin as the non-magnetic one-component toner. The following structural formula as an agent

[0011]

[Chemical 3]

The present invention is characterized in that a polyester negatively chargeable toner containing a boron compound represented by the following is used.

Further, the present invention is characterized in that the content of the charge control agent is 0.5 to 3.0% by weight.

The present invention will be described below. First, the charge control agent contained in the toner used in the device of the present invention is a boron compound of the above structural formula {bis [3,5
-Di (t-butyl) salicylate] boron (III) acid potassium}, and specifically, for example, a boron compound (molecular weight: 542.53, decomposition temperature: 350 ° C) manufactured by Nippon Carlit Co., Ltd. is used. It The polyester negatively charging non-magnetic one-component toner used in the present invention is a polyester binder resin containing a charge control agent comprising the above boron compound.

FIG. 3 shows the results of measurement of the toner charging characteristics with respect to the content of the charge control agent in the present invention (when no external additive is attached). A boron compound manufactured by Nippon Carlit was used as the charge control agent. In the graph of the figure, the horizontal axis represents the content of the charge control agent, the left vertical axis represents the charge amount (T / V), and the right vertical axis represents the toner amount (WST) charged in the opposite polarity. The charge amount was measured by a charge spectrograph. From this result, it can be seen that the best chargeability is exhibited when the charge control agent is contained in an amount of about 2% by weight. It should be noted that the quality of the charging property cannot be judged by the value of the charging property itself, and it is also a necessary condition that the amount of toner charged to the opposite polarity is small. It is said that the amount of the oppositely charged toner is usually 5.0% by weight or less, and preferably 1% or less for improving image quality.

However, the result of the charging characteristics with respect to the content of the charge control agent shown in FIG. 3 is that the external additive is not attached to the toner, and as a result, the charge control agent is charged to the toner binder resin. It can be said that it shows a sex improving effect. Therefore, the chargeability of the toner in the actual use stage is further changed (becomes good) due to the addition of external additives such as a fluidizing agent and a transfer aid. Therefore, FIG. 4 shows the charging property of the toner containing 2% by weight of the charge control agent depending on the presence or absence of the external additive. Toner x does not have an external additive, and toner y does not have a fluidizing agent (R972) in an amount of 0.34% by weight.
Contains 0.34% by weight of a fluidizing agent (same) and a transfer aid (Si
This is the case where 0.84% by weight of O ₂ ) is externally added.

Then, as a result of a test on the chargeability (and fluidity) of the toner when the external additive is added, the content of the charge control agent in the toner is 0.5 to 3.
It was confirmed to be 0% by weight, preferably 1.0 to 2.5% by weight. When the content is less than 0.5% by weight, the chargeability and fluidity of the toner are relatively good in the initial stage, but deteriorate with time. On the other hand, if it exceeds 3.0% by weight, there is a problem that the chargeability and fluidity are poor from the initial stage.

This non-magnetic one-component toner is kneaded by adding the above-mentioned boron compound together with a coloring agent to a polyester resin composed of, for example, bisphenol A-ethylene oxide adduct / cyclohexanedimethanol / terephthalic acid at the above-mentioned predetermined ratio. After that, it is obtained by pulverizing and classifying to granulate toner particles having an average particle diameter of 5 to 20 μm, and then externally adding a fluidizing agent, a transfer aid or the like as an external additive. As the colorant, known dyes and pigments can be used, for example, carbon black, magnetite, nigrosine, aniline blue, chrome yellow, ultramarine, methylene blue chloride, phthalocyanine blue, disazo yellow, rhodamine 6G lake and the like are used. it can. As the fluidizing agent, SiO having a particle size of about 15 nm
₂ etc. can be used, and the particle size of transfer aid is 40 nm.
About SiO ₂ can be used.

The developing device of the present invention basically uses a non-magnetic one-component toner, and the toner is adhered and formed in a thin layer on a toner carrier by a regulating member and is charged and then subjected to development. The device is not particularly limited as long as it is, for example, a device having the configuration illustrated in FIGS. 1 and 2. In the figure, 1 is a non-magnetic one-component toner, 2 is a toner carrier, 3 is a regulating member, 4 is a toner supply member, 5 is a developing bias voltage power supply, 6 is a toner supply bias voltage power supply,
7 is a seal member for preventing toner scattering, 8 is a scraper, and 9 is a scraper.
Indicates a latent image carrier, and 10 indicates a latent image.

The toner carrier 2 is usually composed of a rotating body having a diameter of 5 to 40 mmφ. As a specific example, a round bar or pipe made of aluminum or stainless is cut into a predetermined size, and its peripheral surface is subjected to mechanical polishing such as sand blasting, liquid honing polishing, emery polishing or the like or chemical corrosion to obtain a surface roughness Ra = After cutting a round bar or pipe made of aluminum or stainless steel with a thickness of about 0.1 to 1.0 μm and providing a semiconductive layer of phenol resin or the like on the peripheral surface, further emery polishing or the like on the surface. The surface roughness is Ra = 0.1 to 1.0 μm by mechanical polishing.
Desirably, Ra = 0.2 to 0.4 μm or the like. In addition, as the toner carrier, it is also possible to use one in which the surface of an aluminum roll is mechanically polished and the surface is anodized. When a semiconductive layer is provided on the carrier 2, the volume resistance of the semiconductive layer in the thickness direction is usually 10 ⁵ to
It is about 10 ¹² Ωcm. The suitability of each material of the toner carrier 2, the regulating member 3, and the toner 1 is important for the charging property of the toner 1. From this viewpoint, in the present invention, the toner carrier provided with the semiconductive layer of the phenol resin is provided. The body is the most desirable for Toner 1. The number of rotations of the carrier 2 is usually 100 to 300 rpm. The developing bias applied to the carrier 2 is usually from -50 to
1000-4 with a DC bias voltage of -400V superimposed
It is an AC bias voltage of 000 Vpp. Further, the frequency of the AC bias component is generally 1 to 5 kHz, and it is desirable that the value obtained by dividing the Vpeak value of the AC bias voltage by the value of the gap (μm) between the toner carrier 2 and the latent image carrier 9 is 4 to. The frequency is set to 2.5 to 4.0 kHz on the assumption that it is within the range of 7 V / μm.

The regulating member 3 has a thickness of 0.03 to 0.3 mm.
The elastic support plate 11 such as a flat spring made of stainless steel is vulcanized and adhered to the contact member 12 such as silicon rubber or EPDM rubber. The contact pressure of the regulating member 3 to the toner carrier 2 is set to about 20 to 200 fg / cm. If this contact pressure is less than 20 fg / cm, the toner cannot be sufficiently charged and, conversely, 20
If it exceeds 0 fg / cm, there are problems such as toner aggregation. The toner 1 is transferred to the toner carrier 2 by the regulating member 3.
While being deposited and formed with a layer thickness of about 5 to 30 μm,
It is charged to about −2 to −20 μC / g. From the viewpoint of sufficiently charging the toner 1, the carrier 4 of the regulation member 3
It is most preferable that the contact pressure with respect to 80 to 150 g / cm, and if the contact pressure is set in such a range, the change in the toner chargeability with respect to the change in the attachment state of the external additive becomes extremely small.

The toner supply member 4 is made of aluminum or stainless steel pipe having a thickness of 10 to 20 mm and a thickness of 1 to 4 mm, and a predetermined number of openings are provided on the peripheral surface thereof. The supply member 4 is installed to face the toner carrier 2 with a gap of about 0.5 to 2.0 mm and rotates at a peripheral speed about 1 to 5 times that of the carrier 2. ing.
The opening serves to stir the toner in the device (hopper) and to sprinkle the toner on the toner carrier 2. The opening is approximately 30 mm in parallel with the rotation axis direction of the supply member 4. A rectangular or elliptical shape having a size of about 10 mm is formed in parallel with and is provided uniformly so that the ratio of the opening to the entire peripheral area of the supply member is about 50%. Further, a DC bias voltage of about 200 to 1000 V is applied from the bias power supply 11 between the supply member 4 and the carrier 2, and the polarity of the supply member 4 is the same as that of the toner 1. Furthermore, in order to prevent the toner 1 from filming on the surface of the supply member 4, a Mylar or the like having a thickness of about 50 to 500 μm may be brought into contact with the surface of the supply member 4. It is also possible to use an elastic roll made of urethane rubber or the like as the toner supply member 4 and rotate the elastic roll in contact with the surface of the toner carrier 2.

As the electrostatic latent image holder 9, a rotating body such as a Se type photosensitive body or an organic photosensitive body is usually used. The latent image carrier 9 is usually 100 to 40 relative to the toner carrier 2.
They are installed facing each other with a gap of about 0 μm, preferably about 150 to 300 μm.

[0024]

According to the developing device of the present invention, the toner supplied onto the toner carrier always passes through the regulating member pressed against the toner carrier for layer formation and charging. By the passage of the regulating member, the attachment state of the external additive attached to the toner surface changes. Therefore, FIG. 5 shows a change in the adhesion state of the external additive 13. That is, FIG. 5a is a scanning electron microscope photograph of the unused state of the toner 1 according to the present invention, and FIG. 5b is a scanning electron microscope photograph of the toner 1 according to the present invention after passing through the regulating member for a long time. Is. As a result, a large number of external additives 13 such as the fluidizing agent 13a and the transfer aid 13b are attached to the surface of the toner particles when not in use, but are attached to the surface of the toner 1 in the initial state by passing through the regulating member. It can be seen that the ratio of the external additive 13 being used is decreasing. Also, FIGS.
As a result of analyzing the amount of the external additive in both toners by the fluorescent X-ray analysis method (XFR), it was found that these toners have almost the same amount of external additive. From these, it can be understood that the external additive on the toner is buried inside the toner particles by passing through the regulation member.

In the conventional non-magnetic one-component toner, the chargeability and fluidity of the toner are controlled by the external additive as described above, but the external additive is buried in the toner particles as shown in FIG. 5b. When the amount of the external additive adhering to the surface in the initial state is decreased, both the charging property and the fluidity are decreased. In this respect, according to the present invention, since the toner containing the charge control agent composed of the boron compound is used in the polyester resin, the adhesion state of the external additive is changed (embedded, etc.) by passing through the regulation member. Thus, even if the charge control effect and the fluidity control effect of the external additive are reduced, the chargeability and fluidity of the toner are not deteriorated and are sufficiently maintained.

The effect of the polyester negative charging toner on the charging property is effective only when the charge control agent composed of the boron compound is used, and cannot be obtained by other charge control agents. In addition, it is presumed that the above-mentioned liquidity-related effects are due to the following reasons. That is, in the toner in which the charge control agent is not added internally, the chargeability is controlled by the external additive, but when the external additive is buried by the passage of the regulation member, the toner surface is positive (+).
Charges closer. Therefore, if there is a toner next to which the external additive adheres to the toner surface in the initial state, the external additive itself is negatively (-) charged. Aggregation is likely to occur, which is considered to lead to deterioration of fluidity. On the other hand, in the toner of the present invention containing the above charge control agent internally,
Even if the external additive is buried, the toner surface is negative (-).
Since the toner is charged toward the side (this is because the toner is favorably negatively charged), the aggregation with the adjacent toner as described above does not easily occur, which maintains good fluidity. It is considered to be one.

The developing device of the present invention is preferably applied to a color developing system, but there is no problem even if it is applied to a conventional black toner developing system.

[0028]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples.

Example 1 and Comparative Examples 1 to 4 As the developing device, the one having the entire structure shown in FIG. 1 was used. In addition, this device was set to the following conditions. Toner carrier 2: Phenolic resin semi-conductive layer (10 ⁶
Ωcm) coated roll (24mmφ, 180rp
m) Gap between the latent image bearing member 9 and the toner holding member 2: about 200 μm Toner supply member 4: Stainless steel roll (19 mmφ, 600 rpm) having an opening (30 × 10 mm) Regulation member 3: 0.12 mm thick Leaf spring (SUS30
3) with 1 mm thick EPDM rubber bonded. Contact pressure = about 120 gf / cm Development bias: 240 superposed with a DC component of -200V
AC bias voltage of 0 Vpp and frequency of 4 kHz. Supply bias: AC bias voltage in which a DC component of -800V is superimposed on the developing bias. Further, the following was used as the latent image carrier 9. -Latent image carrier 9: negatively chargeable organic photoconductor drum-Process speed: 160 mm / sec Latent image potential: -100V Back potential: -350V

In this developing device, development is performed as follows. The toner 1 conveyed from the toner storage box outside the developing device (not shown) into the developing device is an electric field between the toner supply member 4 and the toner carrier 2 formed by the supply bias voltage applied from the bias power supply 6. Is supplied from the supply member 4 to the carrier 2. Then, a sufficient charge is given by the regulating member 3 and a thin layer of the toner 1 is formed on the carrier 4. The toner 1 formed in a thin layer on the carrier 2 is retained on the carrier 9 by an alternating electric field between the carrier 2 and the latent image carrier 9 formed by a developing bias voltage applied from a bias power source 5. The electrostatic latent image 10 held by is developed.

In this embodiment, Toner A having the following composition is used.
(Non-magnetic one-component color toner) was used. -Polyester resin: Bisphenol A-ethylene oxide adduct / cyclohexanedimethanol / terephthalic acid) -Charge control agent: Boron compound (manufactured by Nippon Cartrit) ...
2.0 wt% -External fluidizing agent: SiO ₂ (R97 with a particle size of about 15 nm)
2) ... 1.36% by weight-External transfer assistant: SiO _{2 with a} particle size of about 40 nm ... 0.8
4 wt% For comparison, Toner A containing no charge control agent (Comparative Example 1) and 2.0 wt% of KTPB (tetraphenylborate potassium salt), which is the conventional product, as a charge control agent were added for comparison. Toner C (Comparative Example 2),
Similarly, 2.0% by weight of OBC-K1 (one kind of KTPB)
Toner D included (Comparative Example 3), P-51 (4
Toner E (Comparative Example 4) containing 2.0% by weight of a primary ammonium salt compound was used.

When the above developing device was applied to a copying machine and a long-time print test was conducted using each of the above-mentioned toners A to E, when the toner A of this embodiment was used, it was about 5,
Even after copying 000 sheets, deterioration of chargeability and fluidity of the toner was not found, and deterioration of copy image quality and toner scattering were hardly observed.

Further, in order to confirm the effect of improving the chargeability by each charge control agent (internal additive), the charge amount (at the time of setting up the developing device) of toners A to E in the case where no external additive is added is opposite to the charge amount. The amount of toner was measured by a charge spectrograph. The result is shown in FIG. From this result, when the toner A of this embodiment is used, compared with the toner B containing no charge control agent (Comparative Example 1),
It can be seen that the amount of the opposite polarity charged toner is the smallest (close to zero), the chargeability is not deteriorated, and excellent chargeability (and thus good fluidity) is obtained. On the other hand, toners C to E containing a charge control agent other than the present invention (Comparative Example 2)
In the cases of (4) to (4), it is recognized that the charging property tends to deteriorate and the amount of the opposite polarity charged toner tends to increase.

Further, using the toners A and B'under the following conditions, the fluidity measuring device shown in FIG. Toner A: Same as the content of composition of Toner A in the above example. Toner B ′: Toner B of the above-mentioned Example except that the fluidizing agent (R972) was changed to 0.34% by weight and the chargeability-imparting agent TiO ₂ was added at 1.55% by weight. This is an example of a conventional toner having the best fluidity due to the external additive. The fluidity was measured by using a developing device in an unused state, and the toner A or B'was measured by a motor.
Toner supply member 4 rotated at 0 rpm (effective width 295
(mm) was continuously measured from the toner supply port, and the toner movement distance X (Gain) in a predetermined time was measured. The result is shown in FIG. From the results of FIG. 8, it is confirmed that the fluidity of the toner B ′ deteriorates with time, whereas the fluidity of the toner A has little change with time and is fluidity due to the charge control agent.

Example 2 As a developing device, a device having a structure according to the developing device previously proposed by the present applicant (Japanese Patent Laid-Open No. 3-185239) was used. FIG. 2 shows a schematic diagram of the apparatus. That is, in the developing device of the present embodiment, as shown in FIG. 2, an elastic roll as the toner collecting conductive roll 14 is installed so as to rotate in contact with the toner carrier 2, and the conductive roll 14 is biased. By applying a DC bias voltage having a polarity opposite to that of the toner 1 or an AC bias voltage superposed with a DC voltage from the power source 15 in synchronization with the AC bias of the toner carrier, a DC voltage having a polarity opposite to that of the toner 1 is applied to the latent image holding member 9. It is characterized in that it is configured to apply a bias voltage or an AC bias voltage in which DC is superimposed. As a result, all the toner 1 that has passed through the developing area R is adsorbed from the toner carrier 2 to the conductive roll 14 side, then scraped off by the scraper 8a and returned to the inside of the developing device (hopper).

The conductive roll 14 has a conductive rubber layer provided on the peripheral surface of a stainless steel or aluminum shaft or pipe, and further has a skin layer made of a material such as EPDM provided on the outermost surface. is there. The resistance value of the conductive rubber layer is 10 ⁴ to 10 ¹¹ Ωcm, and the rubber hardness thereof is 30.
It is preferably ˜70 degrees. In addition, the conductive roll 1
4 is rotated so as to be in the same direction as the moving direction of the roll surface of the toner carrier 2 and its peripheral speed is 0.
5 to 1.5 times, preferably 1.0 times. The contact depth between the conductive roll 14 and the carrier 2 is about 0-2 mm. Further, an AC bias in which a DC having a polarity opposite to that of the toner 1 is superimposed may be applied to the conductive roll 14, while a DC bias voltage having a polarity opposite to that of the toner 1 may be applied to the latent image holding member 9. Furthermore, when a DC bias voltage is applied to the conductive roll 14, the conductive roll 14 has a resistance of 10 ⁴ to 10 ⁸ Ωcm.
The conductive rubber layer is provided, and in the case of applying an AC bias voltage in which a DC voltage is superposed, a conductive rubber layer of 10 ⁷ to 10 ¹¹ Ωcm is provided. Furthermore, as in this device, the conductive roll 1
When an elastic roll is used as 4, and it is used in contact with the carrier 2, the toner 1 remaining on the carrier 2 after passing through the developing region R can be easily transferred to the conductive roll 14 side. Moreover, the conductive roll 14 may be installed at any position after the carrier 2 has passed through the developing region R regardless of the direction of gravity of the toner.

This developing device was set in the following conditions and incorporated in a copying machine, and a long-term print test was conducted using Toner A in Example 1. Toner carrier 2: Same as in Example 1. Gap between the latent image carrier 9 and the toner carrier 2: Same as in Example 1. Toner supply member 4: same as in the first embodiment. -Regulating member 3: Same as in Example 1. Development bias: The same as in Example 1. Supply Bias: Same as in Example 1. -Conductive roll 14: EPDM rubber layer (10 ⁷ Ωcm)
Elastic roll (10.5 mmφ, 430 rpm) provided with the interference between the conductive roll and the toner carrier 2 (biting contact)
Amount = 250 μm Gap between conductive roll and latent image carrier 9 = about 200 μm Voltage between conductive roll and carrier 2: DC + 100V Further, the latent image carrier 9 used was as follows. Latent image carrier 9: negatively chargeable organic photosensitive drum process speed: the same as in Example 1. Latent image potential: same as in Example 1. Back potential: The same as in Example 1.

As a result of conducting this copy test, about 60,
Even after copying 000 sheets, neither deterioration of charging property nor deterioration of fluidity of the toner was found, and there was almost no deterioration in image quality of the obtained copy image and toner scattering in the machine. As described above, by adopting the developing device provided with the conductive roll for toner recovery as in this embodiment, the toner carrier 2 after passing through the developing area is used.
Since all of the toner on the carrier is removed from the carrier and collected in the developing machine, the same toner remaining on the carrier 2 does not continuously pass through the regulation member 3, and as a result,
The deterioration with time of the toner chargeability was further reduced as compared with the apparatus of Example 1. Therefore, in order to obtain good and stable copy performance of 10,000 sheets or more, in addition to the effect of improving the chargeability of the toner by containing the specific charge control agent as in the present invention, It was confirmed that the developing device having the configuration of the example is more effective.

[0039]

As described above, according to the present invention,
Even if the adhesion state of the external additive on the toner particles gradually changes due to the toner passing through the regulating member that is set to a pressure contact force sufficient to obtain a sufficient charge amount, the toner chargeability and fluidity The property is maintained satisfactorily without deterioration. As described above, since the chargeability and fluidity of the toner are kept good even after long-term use, by applying the apparatus of the present invention to a copying machine or the like, non-image portion fog and image omission, and further, toner inside the machine Almost no scattering occurs, and as a result, the stability of image (copy) quality and the reliability of machine performance can be significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a developing device according to an embodiment of the present invention.

FIG. 2 is a schematic view of a developing device according to another embodiment of the present invention.

FIG. 3 is a graph showing the charging characteristics of the toner with respect to the content of the charge control agent.

FIG. 4 is a graph showing toner chargeability characteristics depending on the presence or absence of an external additive and its type.

FIG. 5 is a scanning electron microscope photograph of the toner, a is a photograph of the toner in an unused state, and b is a photograph of the toner after passing through the regulation member.

FIG. 6 is a graph showing chargeability characteristics of toner depending on the presence / absence of a charge control agent and its type.

FIG. 7 is an explanatory diagram of a measuring device that measures fluidity of toner.

FIG. 8 is a graph showing the flow characteristics of toner.

[Explanation of symbols]

1 ... Non-magnetic one-component toner, 2 ... Toner carrier, 3 ... Regulating member, 9 ... Latent image holder, 10 ... Electrostatic latent image.

Front page continuation (72) Inventor Masatsugu Kajimoto 2274 Hongo, Ebina City, Kanagawa Prefecture, within the Ebina Business Center of Fuji Xerox Co., Ltd. (72) Hideyuki Akagi 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture (72) Inventor Hiroshi Sugizaki 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture, Fujimatsu Xerox Co., Ltd. Takematsu Plant

Claims (2)

[Claims] 1. A non-magnetic one-component toner supplied onto a toner carrier is formed into a thin layer and charged by a regulating member which is pressed against the surface of the toner carrier, and is charged, and the charged toner is applied onto the latent image carrier. In the non-magnetic one-component developing device for developing the formed electrostatic latent image, the following structural formula: A non-magnetic one-component toner developing device comprising a polyester negatively charging toner containing a boron compound represented by 2. The non-magnetic one-component developing device according to claim 1, wherein the content of the charge control agent is 0.5 to 3.0% by weight.