JP2001132732A - Method of manufacturing conductive roller and conductive roller obtained by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a conductive roller having uniform thickness of a coating film on an outer peripheral surface of a roller and the surface roughness of the same, and the conductive roller manufactured by the method. SOLUTION: A solution for forming coating film including a matrix component for forming the coating film, and an A-component (large particles 6) and a B-component (small particles 4) mentioned below, and a base roller 1 are prepared, the solution is applied spirally to an outer peripheral surface of the base roller 1 kept in an approximately vertical state to form a coating part 2, and the roller 1 is left as is for a while, and then dried to form a coating film layer 5 of the solution on the outer peripheral surface of the base roller 1. (A) Nonconductive large particles having an average particle size within the range of 1-12 μm. (B) Nonconductive small particles having average particle size within the range of 0.1 μm and more and less than 1 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive roll such as a developing roll used in an electrophotographic apparatus such as a copying machine or a printer, and a conductive roll obtained by the method.

[0002]

2. Description of the Related Art Generally, copying by an electrophotographic copying machine is performed as follows. That is, the image formation is performed by forming a document image as an electrostatic latent image on the outer peripheral surface of the photosensitive drum rotating about the axis, and attaching toner to the image to form a toner image. As an example of a method of forming a toner image on the electrostatic latent image formed on the surface of the photosensitive drum in this manner, a method using a developing roll is employed. That is, the toner adhering to the developing roll surface is frictionally charged,
A toner image is formed on the surface of the photosensitive drum by transferring the electrostatic latent image on the surface of the photosensitive drum by applying an electric attraction force. Copying is performed by fixing the toner image on copy paper.

Conventionally, the above-mentioned developing roll is composed of a shaft made of a metal core and a rubber layer formed on the outer periphery thereof, and the surface of the rubber layer is roughened by shot blasting, polishing or the like. That was being done. However, in recent years, there has been an increasing demand for lowering the hardness of the developing roll, and since the rubber layer has become lower in hardness, it becomes difficult to perform shot blasting or the like on the rubber layer, and a filler for forming a roughness is formed on the rubber layer. It has been performed to form a coating film containing.

In particular, recently, with respect to the above-mentioned coating film, there is a demand for increasing the electric resistance without using a conductive agent such as carbon black in order to increase the pressure resistance of the developing roll itself. For this reason, using non-conductive particles as a filler for forming the roughness,
The particles are adjusted to adjust the surface roughness. The coating film containing such non-conductive particles is formed, for example, by a roll coating method as follows. That is, as shown in FIG. 5, a base roll 31 having a rubber layer formed on the outer periphery of a shaft body is made vertical, and the base roll 31 is rotated in the circumferential direction to form a coating film containing non-conductive particles on its outer peripheral surface. A coating rotor (not shown) having a solution is brought into contact therewith,
The application section 32 is formed by relatively moving from above to below. If left in this state for a while, the background portion 33 between the spiral coating portion and the coating portion
Then, the solution in the application section above it drips and becomes an application section. Then, drying is performed. In this way, the coating surface is formed on the entire outer periphery of the base roll 31.

[0005]

When the coating film is formed in this manner, the thickness of the coating film on the background portion between the spiral coating portion and the coating portion may be reduced depending on the case. Thick and
, The entire coating film does not have a uniform thickness, and the coating film has irregularities. As a result, there is a problem that the rough surface of the coating film is not uniform.

The present invention has been made in view of such circumstances, and a method of manufacturing a conductive roll having a uniform coating film thickness on the outer peripheral surface of the roll and a uniform surface roughness, and a conductive roll obtained by the method. Its purpose is to provide.

[0007]

In order to achieve the above object, the present invention provides a shaft having a rubber layer formed on the outer periphery thereof and a step of preparing a coating film forming solution, and a shaft having the rubber layer. Spirally applying the coating film forming solution to the outer peripheral surface of the rubber layer in a state where the rubber layer is substantially vertical, and drying the shaft body with the rubber layer coated with the coating film forming solution, Forming a coating film layer comprising the coating film forming solution on the outer peripheral surface of the layer, wherein the coating film forming solution comprises a matrix component for forming a coating film, the following components (A) and (B): The method for producing the conductive roll contained therein is referred to as a first subject, and the conductive roll obtained thereby is referred to as a second subject. (A) Non-conductive large-diameter particles whose average particle size is set in the range of 1 to 12 μm. (B) Non-conductive small-diameter particles having an average particle size of not less than 0.1 μm and less than 1 μm.

That is, the present inventors have conducted a series of studies on the occurrence of unevenness in the thickness of the coating film. As a result, the inventors have found that the occurrence of the unevenness in the thickness of the coating film has a close relationship with the dripping after the formation of the spiral coating portion, and further studied. In the course of this research, during the dripping, the particle size of the particles in the solution used for coating greatly affected, and large particles having a specific particle size and particles having a smaller diameter than the specific particles forming the rough surface of the coating film were formed. When combined, the dripping is performed smoothly, and in the process, the small-sized particles are coordinated around the large-sized particles to prevent uneven distribution of the large-sized particles, so that a coating film having a uniform thickness is obtained. The inventors have found that the present invention has been made, and have reached the present invention.

[0009]

Next, an embodiment of the present invention will be described.

The developing roll according to the present invention is, for example, shown in FIG.
As shown in the figure, a base rubber layer 1b is formed on the outer peripheral surface of a cored bar (shaft) 1a, and on the outer peripheral surface of the base rubber layer 1b,
A coating layer 5 having non-conductive particles having a specific particle size and non-conductive particles having a smaller diameter than the non-conductive particles and having a uniform thickness and a rough surface is formed.

The core 1a is not particularly limited, and may be, for example, a metal core made of a solid metal, or a metal cylindrical body having the inside hollowed out. And, as its material, stainless steel, aluminum and the like can be mentioned. An adhesive, a primer, or the like may be applied on the cored bar 1a, if necessary.
The primer and the like may be made conductive as needed.

As a material for forming the base rubber layer 1b formed on the outer peripheral surface of the cored bar 1a, for example, ethylene-propylene-diene rubber (EPDM), styrene-butadiene rubber (SBR), silicone rubber, polyurethane elastomer and the like are used. can give. Various additives such as a conductive agent and silicone oil are appropriately mixed with this material.
As the conductive agent, carbon black, graphite, potassium titanate, iron oxide, c-TiO ₂ , c-ZnO,
Various types such as c-SnO ₂ (here, “c-” means having conductivity) are exemplified. Examples of the silicone oil include various oils such as dimethyl silicone oil. Above all, it is preferable to use a conductive silicone rubber as a material for forming the base rubber layer 1b from the viewpoint of low hardness and low set.

As a material for forming the coating layer 5 formed on the outer peripheral surface of the base rubber layer 1b (FIG. 1), a matrix component and a non-conductive large particle having an average particle diameter set in a specific range are used. Particles and non-conductive small diameter particles.

The matrix component material is not particularly limited and includes, for example, resin materials such as urethane resins and polyamide resins and rubber materials, and these may be used alone or in combination of two or more. Among them, urethane resin is preferably used in terms of abrasion resistance.

The non-conductive large-diameter particles and the non-conductive small-diameter particles include silica, urethane powder, polyamide powder, fluororesin powder and the like. These may be used alone or in combination of two or more. Above all,
Silica that can make the toner highly charged is preferably used.

The non-conductive large-diameter particles are mainly used for the purpose of roughening the surface of the coating layer, and the average particle size is set in the range of 1 to 12 μm. More preferably, it is in the range of 4 to 6 μm. Further, the non-conductive small-diameter particles are considered to have a function of burying the periphery of the large-diameter particles and preventing uneven distribution of the large-diameter particles, and the average particle diameter is set in a range of 0.1 μm or more and less than 1 μm. More preferably, it is in the range of 0.2 to 0.4 μm. That is, when the diameters of the large-diameter particles and the small-diameter particles deviate from the above range, the dripping of the spiral coating portion is not performed smoothly, and the resulting coating layer does not have a uniform film thickness and unevenness occurs. As a result, the rough surface of the coating film layer becomes non-uniform.
The large and small particles are preferably spherical, but may be elliptical. In addition, when the shape of the above both-diameter particles is not spherical, but the particle size is not uniformly determined such as elliptical or flat, for a sample arbitrarily taken from the population, the longest diameter and the shortest The simple average value of the diameter is defined as the average particle diameter.

The mixing ratio of the non-conductive large-diameter particles is preferably set in the range of 5 to 20 parts with respect to 100 parts by weight (hereinafter abbreviated as "part") of the matrix component. It is more preferably in the range of 8 to 15 parts. If the ratio is out of this range, it tends to be difficult to obtain a coating layer having a desired surface roughness. The mixing ratio of the non-conductive small-diameter particles is 5 to 15 parts per 100 parts of the matrix component.
Preferably, it is set in the range of 0 parts. It is more preferably in the range of 20 to 80 parts. That is, when the mixing ratio of the both-diameter particles deviates from the above range, the amount of the small-diameter particles coordinated around the large-diameter particles while the dripping of the spiral coating portion becomes non-smooth becomes excessive or insufficient, This is because it tends to be difficult to obtain a coating layer having a uniform coating thickness and a rough surface.

The material for forming a coating layer is mixed with an organic solvent and used as a coating solution (usually a suspension). Examples of the organic solvent include methyl ethyl ketone (MEK), methanol, toluene, isopropyl alcohol, methyl cellosolve, dimethylformamide and the like. These may be used alone or in combination of two or more. Particularly, it is preferable to use methyl ethyl ketone from the viewpoint of the solubility of the matrix component. Such a coating film forming solution has a viscosity of 0.05 to 0.06 Pa.
S is preferred in terms of coatability and the like.

The conductive roll according to the present invention shown in FIG. 1 can be manufactured, for example, as follows.
That is, first, the respective components for the material for forming the base rubber layer 1b are kneaded with a kneader such as a kneader, and the base rubber layer 1b is kneaded.
A forming material is prepared. Then, in the hollow part of the cylindrical mold,
A metal core 1a is set, and the cylindrical mold and the core 1a are set.
After the material for forming the base rubber layer 1b is cast into the gap between the above, the mold is covered and heated to crosslink the material for forming the base rubber layer 1b. Thereafter, by removing the mold from the cylindrical mold, a base roll having the base rubber layer 1b formed on the outer peripheral surface of the cored bar 1a is manufactured.

On the other hand, the above-mentioned materials for forming the coating layer are prepared, kneaded with a kneader such as a ball mill or a roll, and an organic solvent is added to the mixture, followed by mixing and stirring. A solution for forming a film is prepared.

Then, as shown in FIG. 2, while rotating the base roll 1 in the circumferential direction around the shaft body, a paint roll 25 rotating around the shaft is brought into contact with the outer peripheral surface thereof.
In this state, the paint roll 25 is moved downward as shown by the arrow, and the coating film forming solution is spirally applied to the outer peripheral surface of the base roll 1.

The coating apparatus of FIG. 2 will be described in more detail with reference to FIG. 3, reference numeral 10 denotes a holding plate erected on the base 9, reference numeral 11 denotes a grooved guide rail, reference numeral 12 denotes a slide body, reference numeral 13 denotes a pair of right and left fitting protrusions which move along the groove of the guide rail 11, reference numeral 14 denotes Is a projecting piece extending from the slide body 12, 14a is a female screw hole provided therein, 15 is a male screw shaft screwed to them, 17 is a speed change motor provided on the support 16 of the holding plate 10 and driving the male screw shaft 15, 1
Reference numeral 9 denotes a motor provided on the slide body 12, and reference numeral 19 a denotes a rotation shaft of the motor 19, which is connected to an upper end portion of the core of the base roll 1. A center pin 18 rotatably supports the lower end of the core of the base roll 1 at its tip. 18a is a screw for sliding the center pin up and down to attach and detach the base roll 1. Thus, the base roll 1 moves vertically (axially) while rotating in the circumferential direction. Reference numeral 21 denotes a coating film forming solution tank, and reference numeral 22 drives a paint roll 25 by a motor. 23 is a support stand, and 24 is a support leg. As described above, this apparatus brings the paint roll 25 into contact with the outer peripheral surface of the base roll 1 while rotating the base roll 1 in the circumferential direction. Is applied with a coating film forming solution.

FIG. 4A shows the spiral coating portion. In the figure, 1 is a base roll (the main part is enlarged in the figure), 2 is a spiral coating portion, 3 is a background portion of the base roll 1 (a base rubber layer on which a coating film forming solution is not applied). 4) are small-diameter particles and 6 are large-diameter particles.
Then, if left in this state for a while, the solution in the spiral application portion drips and covers the background portion 3 as shown in FIG. Then, in this state, the target coating film layer 5 is formed by removing from the coating device and drying. In this case, the large particles 6
, The small-sized particles 4 are coordinated to prevent uneven distribution of the large-sized particles 6, so that the entire coating layer 5 is uniform and the surface roughness is also uniform. The coating layer 5 of the conductive roll thus obtained
Has a volume resistivity of 1.0 × 10 ^{8 to} 1.0 × 10 ¹⁴ Ω ·
cm.

In the conductive roll, since the particles having both diameters are non-conductive particles, the coating layer 5 obtained is a high resistance layer. Therefore, the pressure resistance of a conductive roll such as a developing roll on which the coating layer is formed increases. Therefore, when the roll is incorporated in an electrophotographic copying machine and used together with the action of the coating layer 5, there is no unevenness in the amount of toner transported, and an image having a uniform density can be obtained.

Next, examples in which the present invention is applied to a developing roll will be described together with comparative examples.

[0026]

Example 1 [Production of Base Roll] First, an aluminum core was prepared as a core, and an adhesive was applied to the outer peripheral surface of the core. Next, the above-mentioned core metal was set in the hollow part of the cylindrical mold, and after the silicone rubber compound was cast in the gap between the cylindrical mold and the core metal, the mold was covered and heated. (180 ° C. × 15 minutes), the silicone rubber compound was vulcanized, and then demolded to produce a core metal (base roll) with a base rubber layer.

[Preparation of Coating Solution] Next, 100 parts of a commercially available urethane resin, 10 parts of a commercially available silica having an average particle diameter of 1.5 μm, and 5 parts of a silica having an average particle diameter of 0.3 μm were mixed with each other. The mixture is kneaded using a kneader (roll).
200 parts of EK was added, mixed and stirred to prepare a coating film forming solution. The viscosity of the above solution is 0.05P
as prepared.

[Preparation of Developing Roll] The above-mentioned base roll is set on the apparatus shown in FIG. 3, and a coating film forming solution is spirally applied to the outer peripheral surface of the base rubber layer, followed by drying and heat treatment. A coating layer was formed on the outer peripheral surface of the base rubber layer. In this manner, a developing roll having a base rubber layer formed on the outer peripheral surface of the cored bar and a coating film layer formed on the outer peripheral surface was produced.

[0029]

Example 2 A coating film forming solution was prepared in the same manner as in Example 1 except that the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 20 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0030]

Example 3 A coating film forming solution was prepared in the same manner as in Example 1 except that the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 50 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0031]

Example 4 A coating film forming solution was prepared in the same manner as in Example 1 except that the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 80 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0032]

Example 5 A coating film forming solution was prepared in the same manner as in Example 1 except that the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 100 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0033]

Example 6 A coating film forming solution was prepared in the same manner as in Example 1 except that 20 parts of silica having an average particle diameter of 0.8 μm was used instead of silica having an average particle diameter of 0.3 μm. Then, a developing roll was produced in the same manner as in Example 1.

[0034]

Example 7 A coating solution was prepared in the same manner as in Example 1 except that 50 parts of silica having an average particle size of 0.8 μm was used instead of silica having an average particle size of 0.3 μm. Then, a developing roll was produced in the same manner as in Example 1.

[0035]

Example 8 A coating film forming solution was prepared in the same manner as in Example 1 except that 80 parts of silica having an average particle size of 0.8 μm was used instead of silica having an average particle size of 0.3 μm. Then, a developing roll was produced in the same manner as in Example 1.

[0036]

Example 9 Example 1 was repeated except that 10 parts of silica having an average particle size of 5 μm was used instead of silica having an average particle size of 1.5 μm.
In the same manner as in the above, a coating film forming solution was prepared. Then, a developing roll was produced in the same manner as in Example 1.

[0037]

Example 10 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 20 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0038]

Example 11 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 50 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0039]

Example 12 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 80 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0040]

Example 13 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 100 parts.
Then, a developing roll was produced in the same manner as in Example 1.

[0041]

Example 14 Instead of silica having an average particle size of 1.5 μm,
In the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was blended, and instead of silica having an average particle diameter of 0.3 μm, 20 parts of silica having an average particle diameter of 0.8 μm was blended,
A solution for forming a coating film was prepared. Then, a developing roll was produced in the same manner as in Example 1.

[0042]

Example 15 Instead of silica having an average particle size of 1.5 μm,
In the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was blended, and instead of silica having an average particle diameter of 0.3 μm, 50 parts of silica having an average particle diameter of 0.8 μm was blended,
A solution for forming a coating film was prepared. Then, a developing roll was produced in the same manner as in Example 1.

[0043]

Example 16 Instead of silica having an average particle size of 1.5 μm,
In the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was blended, and instead of silica having an average particle diameter of 0.3 μm, 80 parts of silica having an average particle diameter of 0.8 μm was blended,
A solution for forming a coating film was prepared. Then, a developing roll was produced in the same manner as in Example 1.

[0044]

Example 17 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle size of 11 μm was blended. Then, a developing roll was produced in the same manner as in Example 1.

[0045]

Example 18 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1, except that 10 parts of silica having an average particle diameter of 11 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 20 parts.
Then, a developing roll was produced in the same manner as in Example 1.

[0046]

Example 19 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 11 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 50 parts.
Then, a developing roll was produced in the same manner as in Example 1.

[0047]

Example 20 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 11 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 80 parts.
Then, a developing roll was produced in the same manner as in Example 1.

[0048]

Example 21 Instead of silica having an average particle size of 1.5 μm,
A coating film forming solution was prepared in the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 11 μm was mixed and the mixing ratio of silica having an average particle diameter of 0.3 μm was changed to 100 parts. Then, a developing roll was produced in the same manner as in Example 1.

[0049]

Example 22 Instead of silica having an average particle size of 1.5 μm,
10 parts of silica having an average particle diameter of 11 μm is blended, and instead of silica having an average particle diameter of 0.3 μm, an average particle diameter of 0.8 μm is used.
A coating film forming solution was prepared in the same manner as in Example 1 except that 20 parts of silica was blended. Then, a developing roll was produced in the same manner as in Example 1.

[0050]

Example 23 Instead of silica having an average particle size of 1.5 μm,
10 parts of silica having an average particle diameter of 11 μm is blended, and instead of silica having an average particle diameter of 0.3 μm, an average particle diameter of 0.8 μm is used.
A solution for forming a coating film was prepared in the same manner as in Example 1 except that 50 parts of silica was blended. Then, a developing roll was produced in the same manner as in Example 1.

[0051]

Example 24 Instead of silica having an average particle size of 1.5 μm,
10 parts of silica having an average particle diameter of 11 μm is blended, and instead of silica having an average particle diameter of 0.3 μm, an average particle diameter of 0.8 μm is used.
A coating film forming solution was prepared in the same manner as in Example 1 except that 80 parts of silica was blended. Then, a developing roll was produced in the same manner as in Example 1.

[0052]

Comparative Example 1 A coating film forming solution was prepared in the same manner as in Example 1 except that silica having an average particle diameter of 0.3 μm was not blended. Then, a developing roll was produced in the same manner as in Example 1.

[0053]

Comparative Example 2 In the same manner as in Example 1 except that 10 parts of silica having an average particle diameter of 5 μm was blended instead of silica having an average particle diameter of 1.5 μm, and silica having an average particle diameter of 0.3 μm was not blended. Thus, a coating film forming solution was prepared. And Example 1
A developing roll was produced in the same manner as described above.

[0054]

Comparative Example 3 In the same manner as in Example 1 except that 10 parts of silica having an average particle size of 11 μm was blended in place of silica having an average particle size of 1.5 μm, and silica having an average particle size of 0.3 μm was not blended. Thus, a coating film forming solution was prepared. Then, a developing roll was produced in the same manner as in Example 1.

For each of the developing rolls thus obtained, the surface roughness (Rz), the difference in roughness, and the waviness in the axial direction were compared and evaluated according to the following criteria. The results are shown in Table 4.

[Surface Roughness (Rz)] The surface roughness (circumferential direction) of the developing roll surface was measured by Surfcom (Tokyo Seimitsu Co., Ltd.) in accordance with JIS B0601. Rz
Is a ten-point average roughness obtained from a roughness curve obtained by cutting off a surface undulation component longer than a predetermined wavelength from a contour (which is referred to as a cross-sectional curve) that appears at the cut when cut along a plane perpendicular to the unevenness. Indicates that there is. In addition, "dense part" and "sparse part" show the dispersion state of large-diameter silica.

[Difference in roughness] Surface roughness (Rz) of the dense portion
Was calculated by subtracting the surface roughness (Rz) of the sparse part from.

[Axial Waviness] The difference in height (undulation) from the convex portion to the concave portion of the developing roll surface in the axial direction was measured.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

[Table 3]

[0062]

[Table 4]

From the results shown in Tables 1 to 4, the developing roll of the product of Example has a small waviness in the axial direction and a uniform thickness of the coating film, and the surface roughness shows the difference between the dense portion and the rough portion. Is small,
It can be seen that the roughness of the coating layer surface is also uniform. On the other hand, the comparative product, which is composed only of the large-diameter silica and not used in combination with the small-diameter silica, is inferior to the product of the example in each of the above items.

[0064]

As described above, the method for producing the conductive roll of the present invention is characterized in that the non-conductive large-diameter particles (component A) whose average particle diameter is set in a specific range as the roughness-forming particles are different from the non-conductive large-diameter particles (A component). A coating film forming solution is prepared in combination with the small-diameter non-conductive small-diameter particles (component (B)), and this is spirally applied to the outer peripheral surface of the shaft in a substantially vertical state to form a coating film layer. . for that reason,
On the outer peripheral surface of the base rubber layer, a part of the coating liquid is smoothly applied from the spiral coating film forming solution application portion to the underlying background portion (the surface portion of the base rubber layer where the solution is not applied). And the solution is applied to the ground in the same manner as the application portion. Therefore, the thickness of the obtained coating layer becomes uniform. In addition, during the dripping, small-diameter particles are coordinated around large-diameter particles to prevent uneven distribution of large-diameter particles, and unevenness and unevenness in the roughness of the coating layer surface based on uneven distribution of large-diameter particles. Thus, a uniform rough surface is formed on the surface of the coating layer. The conductive roll thus obtained has extremely excellent properties because the coating layer has a uniform and rough surface. Besides,
Since the components (A) and (B) are non-conductive particles, the coating layer obtained is a high resistance layer. as a result,
The pressure resistance of the conductive roll on which the coating layer is formed is increased,
When it is used by incorporating it into an electrophotographic copying machine, for example, as a developing roll, in combination with the excellent properties of the above-mentioned coating layer, there is no unevenness in the amount of toner transported, and an effect of obtaining an image with a uniform density can be obtained. Become.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a developing roll of the present invention.

FIG. 2 is a schematic explanatory view of a coating apparatus used in the present invention.

FIG. 3 is a perspective view showing details of a coating apparatus.

FIG. 4 is an enlarged view of a main part showing a coating layer formation state of a developing roll of the present invention, wherein (a) shows a state immediately after a coating film forming solution is spirally applied to an outer peripheral surface of a base roll. It is a principal part enlarged view, (b) is a principal part enlarged view which shows the state which the said solution dripped and dried.

FIG. 5 is a schematic explanatory view showing a coating state of a coating film forming solution on a roll surface by a roll coating method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base roll 2 Coating part 4 Small diameter particle 5 Coating layer 6 Large diameter particle

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H077 AD06 FA13 FA22 FA25 FA29 3J103 AA02 AA13 AA21 AA85 EA06 FA18 GA02 GA57 GA58 HA04 HA12 HA20 HA43 HA46 HA48 HA53 HA54

Claims (3)

[Claims] 1. A step of preparing a shaft having a rubber layer formed on its outer periphery and a coating solution, and forming a film on the outer peripheral surface of the rubber layer with the shaft with the rubber layer being substantially vertical. Spirally applying the coating solution, and drying the shaft with the rubber layer coated with the coating film forming solution, and forming a coating layer comprising the coating film forming solution on the outer peripheral surface of the rubber layer of the shaft. And a method for producing a conductive roll, wherein the coating film forming solution contains a matrix component for forming a coating film, and the following components (A) and (B). (A) Non-conductive large-diameter particles whose average particle size is set in the range of 1 to 12 μm. (B) Non-conductive small-diameter particles having an average particle size of not less than 0.1 μm and less than 1 μm. 2. The method according to claim 1, wherein the content of the component (B) is set in a range of 5 to 150 parts by weight based on 100 parts by weight of the matrix component. 3. A conductive roll obtained by the method for producing a conductive roll according to claim 1.