JPH05216252A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide a process for production of a electrophotographic sensitive body which stabilizes a coating condition, obviates the run-out of liquid at the time of coating and can supply a large quantity of photosensitive drums having a fixed profile of film thicknesses. CONSTITUTION:The perpendicularlity of respective both end sections of cylindrial base bodies 40 to 43 stuck on each other to the axial center X of the cylindrial base bodies 40 to 43 is within 0.05mm in the method of perpendicularly stacking the cylindrial base bodies 40 to 43 by bringing the end sections thereof into contact with each other and continuously coating these bodies by using a coating device 1 using a slide hopper type coating head which encloses the outer circumferences of the cylindrical surfaces of the cylindrial base bodies 40 to 43 and annularly supplies a coating material for the photosensitive bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous coating method for electrophotographic photoreceptors.

[0002]

2. Description of the Related Art As a coating method for manufacturing an electrophotographic photosensitive member by coating a coating material for a photosensitive member on the outer surface of a cylindrical substrate, a spray coating method, a dip coating method, a blade coating method, a roll coating method, Also known are slide hopper coating methods and the like.

In the above-mentioned spray coating method, since the solvent evaporates before the coating material for the photoreceptor ejected by the spray gun reaches the outer surface of the object to be coated, the dried and solidified particles adhere to the surface, resulting in smoothness. A good coating surface cannot be obtained and it is difficult to control the film thickness. Further, the blade coating method and the roll coating method have a drawback that uniform coating cannot be obtained due to the viscosity of the coating liquid. On the other hand, the dip coating method improves the smoothness of the coating surface and the uniformity of the coating film, but the control of the film thickness is governed by the physical properties of the coating liquid and the coating speed. Therefore, the adjustment of the coating liquid is very important, but this adjustment is extremely difficult in practice, and the coating speed is slow and the productivity is poor.

For such a coating method, JP-A-58-189
The so-called slide hopper type coating method represented by No. 061 is preferable because it does not have the above-mentioned drawbacks. In addition, JP-A-60-5
No. 0537 also proposes an apparatus in which the dipping method is improved and coating is performed using an annular coating head.

In such a case, in order to pull up the cylindrical substrate, as described in JP-A-61-25149, a method of raising a device stand for supporting the cylindrical body by a cylinder or a motor is often used.

[0006] On the other hand, when processing a machine tool or an object,
Conventionally, various improvements have been added as means for gripping the work or the object.

Most of the improvements are how to grasp an object stably and accurately. Examples of materials that can be used for a cylindrical substrate having a circular cross section include those described in Japanese Utility Model Publication Nos. 61-50687 and 62-106783.

[0008]

When the coating material for the photoconductor is applied to the outer surface of the cylindrical surface of the target cylindrical substrate from the annular coating heads disclosed in the above-mentioned publications, how to apply the coating head and the cylindrical substrate. It is very important to keep the gap uniform in the circumferential direction and how to align the axis of the cylindrical substrate with the center of the coating head.

That is, if the gap is not uniform in the circumferential direction, the coating film thickness becomes non-uniform in the circumferential direction, resulting in uneven electrophotographic characteristics.

On the other hand, the pulling up of a cylindrical substrate is described in JP-A-61-2.
As described in No. 5149, when a mounting table that supports a cylindrical substrate is raised by a cylinder or a motor and coating is applied to one piece,
The coating work becomes intermittent, which causes problems such as variations in the coating film thickness. Therefore, it is desirable that a large number of cylindrical substrates are stacked and continuously moved vertically. According to such a continuous movement mode, once the coating film thickness is set, it is easy to carry out the coating with the same coating film thickness, and the productivity is increased by the continuous operation without time loss before and after.

However, when the conventional cylindrical bases are simply stacked, the bases may sway during coating due to the processing accuracy of the cylindrical bases or may come into contact with the coating head to cause uneven coating film thickness. In addition, a step may be formed at the seam portion, the coating state may become unstable at the step portion, the coating film thickness may become thin, and the coating solution may be cut off.

If the coating of the photoconductor is continued using such a cylindrical substrate, it may cause unevenness in the coating thickness in the circumferential direction and streak failure. Circumferential unevenness and streak defects often appear as image defects, which are fatal defects of the electrophotographic photosensitive member.

[0013]

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to provide an electrophotographic photosensitive member which can stabilize a coating state, eliminate liquid shortage during coating, and supply a large amount of photosensitive drums having a constant film thickness profile. It is to provide a manufacturing method.

[0014]

SUMMARY OF THE INVENTION The object of the present invention is to use a slide hopper type coating head that surrounds the outer circumference of the cylindrical substrate and annularly supplies the coating material for the photoconductor, and uses an end cross section of the cylindrical substrate. A method for producing an electrophotographic photosensitive member, characterized in that, in a method of vertically contacting and continuously applying, the perpendicularity of each end cross section of each of the stacked cylindrical substrates to the axis of the cylindrical substrate is 0.05 mm or less. Achieved by

In the embodiment of the present invention, the cylindricity of the outer surface of the cylindrical substrate after mirror-finishing is 0.01 mm or less, and the outer diameter tolerance is 0.02.
It is preferably within mm.

Next, the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing an outline of an example of a mode of coating using the slide hopper type coating head of the present invention.

X is a cylindrical substrate (hereinafter referred to as a drum) 4,
In the figure, it is a vertical axis line of a base body cylinder 4'formed by aligning axial cores of 40, 41, 42, 43, etc. and vertically stacking them with their end faces in contact with each other.

Reference numeral 2 is a supply device for supplying the drum so that its axis coincides with the vertical axis, 21 is a mounting table, and 22 is a drum supply member.

Reference numeral 1 is a coating device using a slide hopper type coating head, 11 is a slide hopper which surrounds the outer circumference of the cylindrical surface of a drum and supplies a coating material for a photoconductor (hereinafter referred to as coating material),
12 is a dryer, 13 and 13 'are push-up members for the drum, and 14 and 14' are gripping hands.

Reference numeral 3 denotes a take-out device for taking out the drum after coating from the base cylinder. 31 is a hand for taking out the drum.

Reference numeral 40 denotes a supplied drum, 41 denotes an uncoated drum incorporated in a base cylinder, 42 denotes a drum being coated, and 43 denotes a coated and dried drum. However, since the drum hollow portion can be used for removing the drum 43, it is not necessary to completely dry the drum 43 depending on the process and the device.

FIG. 2 shows details of Embodiment 11 of the annular slide hopper.

Reference numeral 111 is an upper ring of the hopper, and 112 is a lower ring, which is preferably made of metal such as stainless steel or brass. 113 is a paint reservoir, 114 is a paint supply slit formed by a conical gap formed between an upper ring 111 and a lower ring 112, 115 is an annular outflow slit, and 116 is a conical slide having a conical surface that opens upward. The surface 117 is an annular coating head having a lip-shaped cross section, and the diameter of the head is adjusted so that the drum can be freely passed and the paint can be attached to the drum.

Reference numeral 118 denotes a waste liquid reservoir of the coating material that has flowed down the conical slide surface and was not applied.

The coating material to be applied to the coating device using the slide hopper type coating head is extruded from the coating material reservoir 113 in consideration of the viscosity, specific gravity, set coating thickness and coating speed specifications, and is extruded from the coating slit 113. Diving, annular outflow slit 1
It overflows from 15 and flows down along the conical slide surface 116 to be transferred from the annular coating head to the cylindrical surface of the drum 42 to form the coating film 5.

In the coating method as described above, the base cylinder can pass through the head ring of the ring-shaped coating head continuously in a stable and smooth manner, and can be evenly adhered and coated from the coating head to the side surface of the drum per area and per hour. It is essential that the vertical axis of the base cylinder is stably located at the center of the head ring and the distance between the drum side surface and the coating head ring is constant.

As a result of various studies, the squareness of each drum shown in FIG.
It is necessary to be within 0.05 mm, and if it exceeds 0.05 mm, for example, if the perpendicularity is 0.07 mm, the bending of the vertical axis of the base cylinder is relatively remarkable with respect to the coating head, and the base cylinder becomes the coating head ring. Frequent contact causes problems with the coating film, and extremely stable coating cannot be performed. However, if it is 0.03 mm, the vertical axis is statistically regarded as a straight line even if the vertical stacking of the drums is performed in an arbitrary order, and it does not come into contact with the coating head ring at all. In the present invention, the squareness is
It specifies within 0.05 mm.

However, even if the perpendicularity with respect to the axial center of the drum is sufficient and the stability and linearity (non-bending) of the vertical axis position of the base cylinder are guaranteed, the cylindrical outer surface of the drum after mirror-finishing is defective. When the cylindricity shown in 3 (b) has surface waviness exceeding 0.01 mm, uneven coating is likely to occur in the axial direction and around the circumference of the drum, and the outer diameter of the drum has a tolerance of more than 0.02 mm (in the present invention, (± 0.01 mm from the standard outer diameter) may cause liquid drainage or conversely liquid drip or dripping at the stacking joint.

Therefore, in the embodiment of the present invention, the cylindricity is 0.
It is preferable that the inner diameter is within 01 mm and the outer diameter tolerance is within 0.02 mm.

According to the above-mentioned constitution of the present invention, it is possible to prevent the substrate from swaying at the time of coating or colliding with the annular coating head to cause nonuniform coating film thickness. Further, the step difference at the seam portion can be suppressed to a minimum, the coating state is stable, the coating film thickness is not thinned, and the coating liquid is not cut off.

In the present invention, as the photosensitive material coating material, an inorganic photosensitive material such as zinc oxide or cadmium sulfide, or an organic photosensitive material such as polyvinylcarbazole and trinitrofluorenone dispersed in a polymer binder can be used. .. Also, in recent years, useful for high sensitivity and durability improvement,
It can also be used for forming a function-separated photosensitive layer in which a charge generation layer and a charge transport layer are laminated.

For example, an azo pigment, a quinone pigment, a perylene pigment, a phthalocyanine pigment, an anthanthrone pigment and the like are dispersed in a polymer binder such as polycarbonate in the charge generation layer, and a polycyclic aromatic compound and a nitrogen-containing cyclic compound are used in the charge transport layer. Etc. can be obtained by dispersing them in a polymer binder.
The thickness of the charge generation layer is 0.01-10 μm, preferably 0.05-5 μm.
And the thickness of the charge transport layer is preferably 5 to 30 μm. The viscosity of the coating material for photoreceptor is in the range of 0.5 to 700 cp, preferably in the range of 1 to 500 cp.

As the electrophotographic drum, there are aluminum, stainless steel, plastic having a conductive layer formed thereon, and the like. Further, an undercoat layer or a charge generation layer may be formed in advance.

[0035]

According to the present invention, the coating state is stabilized,
It is possible to provide a large amount of drums having a constant film thickness profile, by eliminating liquid runoff during coating, and to obtain an electrophotographic photosensitive member having no image defects.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of coating an annular slide hopper.

FIG. 2 is a diagram illustrating an example of an annular slide hopper.

FIG. 3 is an explanatory diagram of squareness, cylindricity, and outer diameter tolerance.

[Explanation of symbols]

 1 annular slide hopper coating device 2 drum supply device 3 drum take-out device 11 annular slide hopper 12 dryer 13,13 'push-up member 14,14' gripping hand 21 mounting table 22 drum supply member 31 drum take-out hand 4 drum 4 'substrate Cylinder 113 Paint reservoir 114 Supply slit 115 Annular outflow slit 116 Cone-shaped sliding surface 117 Annular coating head 118 Waste liquid reservoir X Base cylinder cylindrical axis

Claims (3)

[Claims] 1. A slide hopper type coating head which surrounds the outer circumference of the cylindrical substrate and supplies the coating material for a photoreceptor in an annular shape, and vertically stacks the cylindrical substrate with its end cross-sections in contact with each other. In the method of applying to, the squareness of the cross-sections of both ends of each of the stacked cylindrical substrates with respect to the axis of the cylindrical substrate is 0.
A method for manufacturing an electrophotographic photosensitive member characterized by being within 05 mm. 2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the cylindricity of the cylindrical substrate outside the cylindrical surface after mirror-finishing is within 0.01 mm. 3. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the outer diameter tolerance of the outer surface of the cylindrical substrate after mirror-finishing is 0.02 mm or less.