JP2002323815A - Developer carrying member, and developing device and image forming device using the developer carrying member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer carrying member having an electric hard plating layer free from an abnormal metal deposition part and having very accurate surface roughness, and prevented from causing a tailing phenomenon even in high-speed printing process. SOLUTION: This developer carrying member feeding developer while carrying it on its surface has an intermediate layer and the electric hard plating layer on a base plate, and a joining layer provided between the intermediate layer and the electric hard plating layer in order to improve contact between both layers is a substantially non-magnetic layer formed of substance whose volume susceptibility is <=1(μH×m<-1> ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine, a laser beam printer, a facsimile,
The present invention relates to a developer carrying member, a developing device, and an image forming device used for a printing device and the like.

[0002]

2. Description of the Related Art Conventionally, a developer carrying member has a roughened surface for transporting the developer. As old as
Japanese Patent Application Laid-Open No. 4-79043 discloses a method in which a knurled groove is mainly used in two-component development, and a method mainly used in one-component development as disclosed in JP-A-55-26526. Some of them have been subjected to a roughening treatment.

[0003] In particular, as a material of a developer carrying member subjected to a surface roughening treatment, a surface coating layer of a relatively hard material is provided on a substrate in order to prevent the unevenness of the developer carrying member from being worn away during long-term use. Has been proposed. For example, JP
Japanese Patent Application Laid-Open No. 8-132768 discloses a developer carrying member provided with a nitride such as TiN and CrN, a carbide such as TiC and B ₄ C, or a Ni—P plating layer on the surface of an aluminum substrate. Japanese Patent No. 230676 discloses a developer carrying member in which a Cr plating layer, an alumite layer, a Ni-P plating layer or a nitriding layer is provided on the surface of a substrate made of aluminum, brass or stainless steel.
No. 5 discloses that Cr, Cu-Cr, Ni-Cr, Cu-Ni-C
A developer carrying member provided with a plating layer such as r or Ni-Cu-Ni-Ca is described.

Some of these abrasion resistant surface coatings include:
There is also a highly wear-resistant plating layer, such as an electroless Ni-P plating layer, whose Vickers hardness Hv becomes 900 or more by a heat treatment at 300 to 500 ° C. (Japanese Patent Laid-Open No. 58-1327).
No. 68). However, when such a heat treatment is performed, the non-defective product rate is considerably reduced. This is because the substrate undergoes thermal deformation of several tens of μm or more in the direction perpendicular to the longitudinal direction, the distance between the electrostatic image carrier and the developer carrier varies locally, and image unevenness occurs in the toner image. by.
In particular, in forming a high quality toner image, such image unevenness becomes a major obstacle.

The surface coating layer formed by electroplating is hard and has excellent wear resistance. Moreover, it is advantageous in that high-temperature heat treatment is not required unlike the above-mentioned Ni-P plating.

However, in electroplating, a metal is deposited from a plating solution and deposited on a substrate in proportion to the density of lines of electric force, and generally fine projections and cracks are formed on the substrate surface. In the case of a projection, the lines of electric force tend to concentrate toward the apex, and in the case of a crack, toward the edge. Therefore, the metal is abnormally deposited on those portions, and it is difficult to form a hard plating layer having a predetermined surface roughness.

Therefore, Japanese Patent Application Laid-Open No. 2000-284586 discloses that an electroless plating intermediate layer is formed on a substrate to cover projections and cracks on the substrate surface, and an electric hardening layer is formed thereon via a Ni bonding layer. A developer carrying member having a plating layer has been proposed.

[0008] In recent years, with the trend of increasing the speed of image forming apparatuses, it is required to achieve a higher speed while maintaining a basic hardware configuration. When applied to a high-speed image forming apparatus, FIG.
A phenomenon (hereinafter referred to as tailing) in which ears protrude as shown in FIG. 3B occurs in a non-image portion at the rear end of an image such as a horizontal line as shown in FIG.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developer carrying member which does not cause such tailing.

Another object of the present invention is to provide a developing device and an image forming apparatus capable of forming a good toner image by using such a developer carrying member.

[0011]

According to the present invention, there is provided a developer carrying member for carrying and transporting a developer on a surface, wherein the developer carrying member comprises a substrate, an intermediate layer having a surface smoother than the substrate surface, and a bonding layer. And a developer carrying member having an electrohard plating layer, wherein the bonding layer is formed of a substance having a volume susceptibility of 1 (μH · m ⁻¹ ) or less.

According to the present invention, there is provided an electrostatic image carrier for forming an electrostatic image on a surface thereof, and a developer carrier member for carrying and transporting a developer disposed opposite to the electrostatic image carrier. The present invention relates to a developing device having a developing device, wherein the developer carrying member has a substrate, an intermediate layer, the bonding layer, and an electro-hard plating layer.

Further, the present invention has an electrostatic image carrier for forming an electrostatic image on a surface thereof, and a developer carrier member disposed to face the electrostatic image carrier, wherein the developer carrier member In an image forming apparatus that transports a developer carried thereon to an electrostatic image carrier facing portion and develops an electrostatic image, the developer carrying member includes a substrate, an intermediate layer, the bonding layer, and an electro-hard plating layer. The present invention relates to an image forming apparatus having:

In the developer carrying member according to the present invention, in order to improve the adhesion between the intermediate layer and the electric hard plating layer, the bonding layer provided between the two layers has a volume susceptibility of 1 (μH · m ⁻¹ ). A substantially non-magnetic layer formed of the following substances, which has solved the problem of tailing.

[0015] When a conventional Ni-plated bonding layer, the volume magnetic susceptibility of Ni is 49000 ^- ferromagnetic and (μH · m ^1), it is considered that this is tailing has occurred due. That is, since the Ni plating bonding layer is ferromagnetic, it affects the shape of the spikes of the toner carried on the surface of the developer carrying portion, and the toner flies to the electrostatic image carrier while the spikes of the toner remain long. it is conceivable that. The tailing becomes worse as the speed increases. The reason is that the mechanical stress and frictional heat that the toner receives near the developer carrying member increase,
It is considered that the toner is likely to aggregate.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A developer carrying member according to the present invention comprises:
By providing a substantially non-magnetic bonding layer between the intermediate layer and the electro-hard plating layer, it is possible to form an electro-hard plating layer having a high-precision surface roughness without an abnormal metal deposition portion, and a developer carrying member. Does not cause tailing even if the peripheral speed of 570 mm · S ⁻¹ or more.

FIG. 1 is a schematic cross-sectional view of a developer carrying member according to the present invention. The basic structure thereof is such that an intermediate layer P ₁ , a bonding layer P ₃ and an electric hard plating layer P are formed on a substrate S.
₂

FIG. 2 is a conceptual diagram of the surface roughness of a developer carrying member having an intermediate layer, a bonding layer and a hard electroplated layer formed on a substrate.

M ₁ is a conceptual diagram of a surface roughness curve of the substrate S, in this case, when an aluminum cylindrical substrate is subjected to blast processing to provide irregularities on the surface. There are numerous small protrusions and cracks, along with the overall large roughness. When an electric hard plating layer is formed on such a substrate surface, the roughness of the hard plating layer surface is sharply emphasized under the influence of minute projections and cracks on the substrate surface. With such a surface shape, the effect of imparting electric charge to the developer is inferior, and the developer falls into a steep recess and is fixed, thereby causing developer contamination of the developer carrying member. Therefore to form an intermediate layer P ₁ on the substrate surface, the surface roughness is shown as curve m _2. In this example, since the intermediate layer of the electroless plating, the roughness curve m ₂ formed is smooth and not affected by the minute protrusions and cracks of the substrate surface. Next, when forming the bonding layer P ₃ and electroplating layer P _2, the roughness curve of the bonding layer and electroplating layer will be denoted as m ₃ and m _4. The m _4, since the smooth surface shape of the intermediate layer, has a similarly smooth curve.

Next, a preferred configuration of the developer carrying member according to the present invention will be described.

The substrate has a shape such as a cylinder (hereinafter, also referred to as a sleeve), a column, or a flat plate according to the form of the developing device to which the developer carrying member is applied.

The developer-carrying member has an appropriate surface roughness, usually Rz of 0.3 to 7 μm or Ra of 0.05 to 1.1.
Preferably it has a surface roughness in the range of μm. For this purpose, it is possible to perform a surface roughening treatment after forming an electro-hard plating layer to be a surface layer of the developer carrying member according to the present invention, but there is a risk of peeling of the plating layer and adhesion of blast abrasive grains. At this point, the surface of the base material is subjected to a roughening treatment in advance, and Rz is 1 to 8
It is preferable to set the surface roughness of μm or Ra to about 0.1 to 1.2 μm. As the surface roughening treatment, blast treatment with spherical particles is preferable.

Note that Ra and Rz are in accordance with JIS B0601.
Where Ra is arithmetic mean roughness and Rz is ten-point mean roughness.

The material of the substrate is preferably aluminum, aluminum alloy, or copper alloy. These are non-magnetic and suitable for development using a magnetic field. In addition, since the metal is a relatively soft metal having a Vickers hardness of 40 to 180, it can be easily subjected to surface roughening treatment and has a heat conduction coefficient of 150.
Since it is as high as W / m · K or more, it is difficult to store heat, and it is hard to cause a decrease in dimensional accuracy due to thermal expansion during use.

The thickness of the intermediate layer is preferably 3 μm or more from the viewpoint of enclosing minute projections and cracks on the surface of the substrate. Further, the thickness of the intermediate layer is determined by forming a uniform plating layer and contributing to toner transportability. The thickness is preferably 30 μm or less in order to make the uneven shape appear on the surface of the plating layer.

As the intermediate layer, Ni-P, Ni-
B, Pd-P, Ni-Co-P, Ni-Fe-P, Ni
Electroless plating layers such as -WP, Ni-Cu-P, and Co-P are suitable, and Ni-P is particularly preferable in terms of high versatility for industrial use and quality stability.

The bonding layer enhances the adhesion between the intermediate layer and the electro-hard plating layer, and prevents the electro-hard plating layer from peeling off even when used as a developer carrying member for a long time.

The bonding layer has a volume susceptibility of 1 (μH
m ^-1 ).

As such a substance, particularly, Cu and Al are preferable. The thickness of the bonding layer is preferably 0.2 μm or more in order to sufficiently generate a bonding function, and is preferably 2 μm or less from the viewpoint of formation cost.

The electric hard plating layer (hereinafter also referred to as a hard plating layer) preferably has an Hv of 300 or more, particularly 500 or more, from the viewpoint of abrasion resistance. As this hard plating layer,
Cr, Pt, Rh and the like are preferable, and particularly, Hv is 600.
The above Cr is preferable.

The thickness of the hard plating layer is preferably 0.2 μm or more from the viewpoint of durability. Further, from the viewpoint of good surface properties, it is better not to be too thick, and it is preferable that the thickness is 5 μm or less. Further, from the viewpoint that the smooth surface shape of the plating intermediate layer also appears on the surface of the hard plating layer, it is better that the hard plating layer is thinner than the plating intermediate layer.
/ 10 or less is particularly preferred. The volume susceptibility of the substance forming the intermediate layer and the electro-hard plating layer is 5 (μH · m ⁻¹ ).
The following are preferred.

In the present invention, a contact-type surface roughness meter (Surfcoder SE-3300, manufactured by Kosaka Laboratory Co., Ltd.) was used for measuring the surface properties. The measurement conditions are a cutoff value of 0.8 mm, a measurement length of 2.5 mm, a feed speed of 0.1 mm / sec, and a magnification of 5000 times.

FIG. 4 shows an example of the developing device according to the present invention. The developing sleeve 43 of the developing device 4 is subjected to blasting with a spherical particle blast (FGB) # 600 on an aluminum A6063 having a diameter of 32.3 mm, which is a non-magnetic member.
As shown in FIG. 1, a plating process was performed. A fixed magnet 41 having six magnetic poles is provided inside the developing sleeve. The toner used as a developer is supplied to the developing sleeve 4 by a plate member 42 which is a magnetic blade.
3 is regulated, and G2 is set to 180 μm. When the developer passes through the gap G2, a thin developer layer having a predetermined thickness is formed.

The developing sleeve is disposed with a gap G1 from the electrostatic image carrier 1.

As shown in FIG. 6, the plate member 42 made of SPCC (cold rolled steel plate), which is a developer layer forming member, has a sharply cut end (developing carrier side). As a result, the plate-like member 2 having a flat cross section as shown in FIG.
Since the magnetic field formed between the plate-shaped member and the developer carrier is concentrated in a narrow area, the ability to form a thin toner layer is enhanced, as compared with the case where 42 is used.

As a result, a strong triboelectric charge is given to the toner, so that a sufficient charge can be given to the toner.

The thickness t of the plate member 42 at the portion where the plate member is screwed to the support member 44 in the configuration of the present embodiment.
1 is 1.6 mm, and the thickness t2 of the tip is 0.3 mm
It is.

The developing device shown in FIG. 4 is provided with a first stirring rod 4B and a second stirring rod 4C for stirring the toner, and a toner remaining amount detecting sensor 44.

A fixed magnet 41 having a magnetic field pattern as shown in Table 1 is provided inside the developing sleeve 43.

[0040]

[Table 1]

FIG. 5 is an example of an image forming apparatus according to the present invention.

The image forming apparatus has 10 electrostatic image carriers.
An 8-mm diameter a-Si drum photoconductor 1 was used. The process speed is 450 mm / sec and a black-and-white digital copying machine with 85 sheets per minute. a-Si is an organic photoreceptor (OPC)
Although the relative dielectric constant is as large as about 10 and the charging potential is relatively low, the latent image potential cannot be sufficiently obtained as compared with OPC.
It is characterized by high durability, a service life of 3 million sheets or more, and suitable for high-speed machines.

The photosensitive member is charged, for example, by +
After being uniformly charged to 340 V, image exposure 12 is performed at 600 dpi. The image exposure 12 forms an image-like latent image by attenuating the surface potential of the exposed portion to +50 V using a semiconductor laser as a light source. The wavelength is 680 nm.

The laser beam is applied to the drum via a collimator lens, polygon scanner, fθ lens, folding mirror, dustproof glass, and the like. The spot diameter on the drum is imaged on the drum with a spot size slightly larger than 42.3 μm for one pixel of 600 dpi = 42.3 μm. Form a latent image. After that, development is performed, and the post-charger 1
At 0, the toner is positively charged, and the attraction between the photoconductor and the toner is weakened to facilitate transfer and separation. In the present embodiment, development is performed using a black magnetic one-component developer, which is a simple and highly durable development method requiring no maintenance until the life of the developing sleeve. The toner is a positive toner and has a weight average particle size of 8.0 μm. In the toner supply operation, when the toner near 4B in FIG. 4 runs out, a signal for rotating the mag roll is output by the piezoelectric element signal, and the toner is supplied from the hopper 9 into the developing device by the rotation of the mag roll. After the developing device 4 converts the electrostatic latent image into a toner image, the post-charger 1
At 0, a total current of +100 μA (AD + DC) is applied to charge the toner image, and then the toner image is transferred to a transfer material advancing in the direction of the arrow by a transfer separation charger 5 and sent to a fixing device 7 to fix the toner image. 6 is a cleaner.

When an a-Si drum is used as an electrostatic latent image carrier of a high-speed machine, since the image flow and the a-Si have a temperature characteristic in the morning, this is prevented for the purpose of preventing and maintaining the stability.
There is a drum heater inside the Si drum. At this time, if SUS is used as the material of the developing sleeve, deformation due to heat of the drum heater is likely to occur due to low thermal conductivity. Therefore, as the material of the developing sleeve, it is preferable to use aluminum or an aluminum alloy which has a large thermal conductivity and a small thermal deformation by the drum heater. The developing sleeve rotates at a speed of 767.5 mm / s. The distance G1 between the developing sleeve and the photosensitive drum was 220 μm, the developing bias was 1 kVpp in amplitude, and the frequency was 2.7 kHz.
A voltage obtained by superimposing a DC voltage of 280 V on an AC voltage having a z / duty ratio of 35% is applied to the developing sleeve.

Examples will be described below, and prior to that, the outline of the toner used here will be described. Here, a magnetic toner in which magnetic particles are dispersed in a resin is used as the developer.

The volume average particle size of the toner is 4 to 10 μm (preferably 6 to 8 μm). If the volume average particle size is less than 4 μm, it is difficult to control the toner, and particularly the solid black portion tends to have a low density. Above this, the resolution of the fine lines is poor. Here, those having a volume average particle diameter of 7 μm were used.

The particle size distribution of the toner can be measured by various methods. Here, a Coulter counter TA-II type manufactured by Coulter Co., Ltd. was used. A few mg of a sample was ultrasonically dispersed for several minutes in a 1% NaCl aqueous solution to which a few drops of a surfactant were added as an electrolytic solution, and the particle size distribution of 2 to 40 μm particles was measured through an aperture of 100 μm. Here, for the above-mentioned volume average particle diameter of 7 μm, 4 μm
The amount of fine powder of m or less is 20% or less in number, and the amount of coarse powder of 15 μm or more is 5% or less in volume.

The binder (binder resin) of the toner generally includes a styrene-based styrene-acryl copolymer, a styrene-butadiene copolymer, a phenol resin, a polyester, and the like. Here, a styrene-acrylic copolymer and a styrene-butadiene copolymer were used in a ratio (weight) of 8: 2.

Nigrosine, quaternary ammonium, and the like can be used as the charge control agent (usually added internally to the toner, but can also be added externally).
Triphenylmethane, imidazole and the like are used for the positive toner. Here, triphenylmethane (resin component 1)
2 parts (by weight) were added internally (based on 00 parts).

A developing sleeve is formed in the same manner as in Production Example 1 below.

Further, paraffin wax was used as a wax component, and magnetite was used as magnetic particles. Further, silica was externally added to the toner as a fluidizing agent.

Next, the developing sleeve will be described.

(Example 1) [Blasting treatment] Outer diameter 32.3 mm, wall thickness 0.65 m
The surface of the m (Al) sleeve was blasted. Blast treatment was performed as follows using spherical glass beads of 600 mesh as blast abrasive grains.

The blast pressure was applied to the sleeve rotating the glass beads at 36 rpm from four directions from four 7 mm diameter nozzles at a distance of 150 mm from the sleeve.
2.5 kg / cm ² for 9 sec (Total 36s
ec) sprayed. After the blast treatment, the surface of the sleeve is washed and dried in a washing step. The surface roughness Ra of the sleeve is 0.6 μm, and Rz is 4 μm. [Plating Pretreatment] The surface of the Al sleeve is zincated, and zinc is adhered to the surface. The zincate process is
The adhesion between the Al sleeve and the Ni-P plating is improved. For the zincate treatment, a commercially available zincate treatment agent (trade name: Schuma K-102, manufactured by Nippon Kanigen Co., Ltd.)
Was used. [Ni-P plating] An Al sleeve is immersed in a Ni-P plating solution to form a 19 µm-thick electroless Ni-P plating layer. The P concentration in the Ni—P plating layer is 10.3 wt%. In general, it is preferable to adjust the P concentration in a range of 5 to 15 wt%. A commercially available plating solution (trade name: S-754, manufactured by Nippon Kanigen Co., Ltd.) was used as the electroless Ni-P plating solution. [Cu plating] Copper sulfate was used as a soluble copper salt used in the plating bath, and its content in the plating bath was 0.1 mol.
1 / l.

A surfactant (trade name: Nonion NS230, manufactured by Nippon Oil & Fats Co., Ltd.) is used to prevent pits or to improve the smoothness and appearance of the plating film. 30 g / l.

The plating bath temperature is about 30 ° C., the cathode current density is 5 A / dm ² , and the layer thickness is 1 μm. [Cr plating] The Ni-plated sleeve is
Electroplating is performed by immersion in a plating solution to form a 1 μm thick Cr plating layer. A commercially available catalyst chloric anhydride solution was used as the Cr plating solution.

The magnetic properties of the entire Cr-plated sleeve have a coercive force of 40 Oe and a saturation magnetic flux density of 60 Gauss.

The hardness H of the Cr-plated sleeve is
v is 605 to 640, and the surface roughness is Ra of 0.5
3 μm, and Rz is 3.54 μm. [Mounting of Magnets] The magnets shown in Table 1 are mounted in the sleeve treated in this manner to form a developing sleeve. <Evaluation Results> The developing sleeve described above was mounted on the developing device shown in FIG. 4, and this was applied to the image forming apparatus shown in FIG. 5 to perform an image output durability test. It was evaluated by. The results were as shown in Table 2 below. Embodiments other than Embodiment 1 are also described. The thickness of the plating layer in each of the examples and comparative examples is the same as that in the first embodiment.

(Embodiment 2) Only the point that G2 is 240 μm is different from Embodiment 1 of the present invention, and only this point will be described.

Since G2 is large, the amount of toner on the developer carrying member slightly increases, and the charge amount of the toner slightly decreases, so that the tailing slightly deteriorates. However, the superiority to the comparative example is still recognized.

(Embodiment 3) As shown in FIG.
2 is rectangular (thickness t1 = t2 = 1 m)
Only the point m) is different from the first embodiment, and only this point will be described.

Since the cross-sectional shape of the blade is rectangular,
Because the toner regulation ability is slightly reduced, the toner amount on the developer carrying member is slightly increased, and the charge amount of the toner is slightly decreased.
Although the tailing slightly deteriorates, the superiority to the comparative example is still recognized.

Example 4 Example 4 differs from Example 1 only in that the bonding layer of the developer carrying member is electro-aluminum plated.
Only this point will be described.

A plating bath was prepared by adding 4 g / l of polystyrene to a bath prepared by mixing and melting AlCl ₃ and 1-methyl-3-propylimidazolium bromide in a molar ratio of 2: 1. Next, as a pretreatment, the sleeve was subjected to alkali degreasing, electrolytic cleaning, and pickling, followed by water cleaning, alcohol cleaning, and drying.

The aluminum plate was used as an anode and the sleeve was used as a cathode. The aluminum plate was immersed in the plating bath maintained at 50 ° C. for 2.5 minutes, and subjected to aluminum plating in a dry nitrogen gas atmosphere with a direct current. The plating bath was stirred with a stirrer.

(Example 5) Only the point that the intermediate layer of the developer carrying member is electroless nickel-boron plating differs from that of Example 1, and only this point will be described.

The Al sleeve was immersed in an electroless nickel-boron plating solution (containing dimethylamine borane as a reducing agent and having a pH of 6.5) at 70 ° C. to form a plating layer. The B content in this plating film is 1.02wt
%Met.

(Embodiment 6) This embodiment is different from Embodiment 1 only in that the intermediate layer of the developer carrying member is formed by electroless Pd-P plating.

Pd chloride 1.5 g / l Ethylenediamine 5 g / l Sodium hypophosphite 7 g / l thioglycolic acid 0.03 g / l pH 7 Temperature 50 ° C. Al sleeve is immersed in a Pd-P plating solution of the above composition. A plating layer having a thickness of 19 μm is formed.

(Embodiment 7) This embodiment is different from the embodiment 1 only in that the electro-hard plating of the developer carrying member is made of a material mainly composed of Pd.

Dichlorotetraammine Pd 4 g / l Pyridine 3-sulfonic acid 5 g / l Thallium nitrate 27 ppm Ammonium nitrate 400 g / l Ammonium chloride 107 g / l pH 8 Temperature 50 ° C. Current density 2 A /
performed in dm ² 20 seconds to form a Pd plating 1.5μm thick.

[Comparative Examples 1 to 6] The only difference is that electric nickel plating was performed instead of the electric copper plating of Example 1, and only this point will be described.

The Ni-P plated sleeve is replaced with Ni
Electroplating is performed by immersion in a plating solution to form a 1 μm thick Ni plating layer. A sulfuric acid acidic hexahydrated nickel sulfate solution was used as the Ni plating solution.

Regarding “tailing”, the output image corresponding to the input image of the horizontal line having a width of 4 pixels is indicated by 場合 when there is almost no tailing, な い when it cannot be understood unless observed with a 20 × magnifying glass, and observed with the naked eye The case of worrisome was evaluated as △, and the case of worrisome observation with the naked eye was evaluated as x.

The "image characteristics after durability" is obtained by subjecting the results of the subjective evaluation or the qualitative evaluation to the images after the durability to different levels.

Here, “after endurance” means that the temperature is 23 ° C. and 50% R
In the environment of H, it is assumed that a document having an image ratio of 6% is continuously output on both sides of a laterally fed A4 size transfer material.
It means after repeating 10,000 times. The daily operation time is about 12 hours, and the output amount is about 60,000 pages.

Comparative examples 1 to 3 of the prior art described in Table 2
As described above, the tailing is affected by the magnetism of the layer constituting the developer carrier, as described above. The reason is that if the magnetic strength of the bonding layer is strong, the tailing is affected by the magnetic field in the development area. It is considered that the disturbance occurs, and the toner ears on the developer carrier are entangled with each other, so that the toner ears become longer and fly directly to the latent image carrier.

[0079]

[Table 2]

In this regard, as shown in Table 3, by providing copper plating having extremely low magnetism as the bonding layer, the difference in the thermal expansion characteristics between the intermediate layer and the electric hard plating layer can be suppressed while suppressing tailing. The resulting internal residual stress can be reduced, and peeling of the developer charge control layer can be prevented. Even if the magnetic properties of the bonding layer are weakened, if the other layers are magnetic, the tailing becomes worse.

[0081]

[Table 3]

The volume susceptibility was measured by a magnetic susceptibility measuring device MPMS (trade name) manufactured by Quantum Design Japan. The measurement piece was a disk having a diameter of 1.5 mm and a thickness of 60 μm.

[0083]

As described above, according to the present invention, the problem of tailing can be solved by forming the bonding layer with a substance having a volume susceptibility of 1 (μH · m ⁻¹ ) or less. is there.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a developer carrying member of the present invention.

FIG. 2 is a conceptual diagram of a surface roughness of a developer carrying member of the present invention.

FIG. 3 is an explanatory diagram of a phenomenon in which an image protrudes in a spike shape into a non-image portion.

FIG. 4 is a schematic view showing an example of a developing device according to the present invention.

FIG. 5 is a schematic diagram illustrating an example of an image forming apparatus according to the present invention.

FIG. 6 is a schematic sectional view illustrating a schematic configuration of a developer amount regulating member.

FIG. 7 is a schematic sectional view illustrating another schematic configuration of the developer amount regulating member.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/09 G03G 15/09 A F-term (Reference) 2H031 AC02 AC10 AC11 AC15 AC19 AC31 AC34 AD03 BA06 BB01 2H077 AB03 AB14 AB18 AC03 AD02 AD06 AD13 AD18 BA07 DA15 EA03 FA01 FA12 FA14 FA16 FA19 3J103 AA02 AA14 AA81 AA85 FA18 GA54 GA57 GA58 GA60 HA05 HA36 HA37 HA55 4K024 AA01 AA02 AA09 AB02 AB17 BA06 BA09 BB16 GA01 GA02

Claims (18)

[Claims] 1. A developer carrying member for carrying and transporting a developer on a surface, the developer carrying member having a substrate, an intermediate layer having a surface smoother than the substrate surface, a bonding layer, and an electro-hard plating layer. The bonding layer has a volume susceptibility of 1 (μH · m
^-1 ) A developer carrying member formed of the following substances. 2. The method according to claim 1, wherein the substrate has an Rz (ten-point average roughness) of 1 to 8 μm.
The developer carrying member according to claim 1, wherein the developer carrying member has a surface roughness of 0.1 to 1.2 m or m or Ra (arithmetic roughness). 3. The developer carrying member according to claim 1, wherein the substrate is made of aluminum, an aluminum alloy or a copper alloy, and has a Vickers hardness Hv of 40 to 180. 4. The developer carrying member according to claim 1, wherein the intermediate layer has a thickness of 3 to 30 μm. 5. The developer carrying member according to claim 1, wherein the intermediate layer is an electroless Ni—P plating layer. 6. The developer-carrying member according to claim 1, wherein the electro-hard plating layer has a thickness of 0.2 to 5 μm. 7. The developer carrying member according to claim 1, wherein the thickness of the electro-hard plating layer is smaller than that of the intermediate layer. 8. The method according to claim 1, wherein the bonding layer is selected from a Cu plating layer and an Al plating layer.
3. The developer carrying member according to item 1. 9. The developer carrying member according to claim 1, wherein the thickness of the bonding layer is 0.2 to 2 μm. 10. The developer carrying member according to claim 1, wherein the electric hard plating layer is a Cr plating layer. 11. The developer carrying member according to claim 1, wherein the intermediate layer is an electroless Ni—P plating layer, and the electric hard plating layer is a Cr plating layer. 12. The developer carrying member according to claim 11, wherein the bonding layer is a Cu plating layer. 13. A developing apparatus comprising: an electrostatic image carrier for forming an electrostatic image on a surface thereof; and a developer carrier member for carrying and transporting a developer disposed to face the electrostatic image carrier. A developing device, wherein the developer carrying member is the developer carrying member according to claim 1. 14. The developing device according to claim 13, wherein the substrate of the developer carrying member is a cylindrical substrate, and has a magnetic field generating means in the cylinder. 15. An electrostatic image bearing member for forming an electrostatic image on a surface thereof, and a developer carrying member disposed opposite to the electrostatic image bearing member, wherein the developer carrying member is supported on the developer carrying member. An image forming apparatus which transports the developer to an electrostatic image bearing member facing portion and develops the electrostatic image, wherein the developer bearing member is the developer bearing member according to claim 1. Forming equipment. 16. The image forming apparatus according to claim 15, wherein the substrate of the developer carrying member is a cylindrical substrate, and has a magnetic field generating means in the cylinder. 17. The developer carrying member has a peripheral speed of 570 m.
The image forming apparatus according to claim 16, wherein the image forming apparatus is driven to rotate so as to be at least m · s ⁻¹ . 18. The image forming apparatus according to claim 16, wherein the electrostatic image carrier has a photosensitive layer mainly composed of amorphous silicon.