JPS60146237A - Coating method and its device of electrophotographic recording body base material or the like - Google Patents

Abstract

PURPOSE:To apply stably and uniformly a coating liquid by providing a distributing slit on a distributing chamber without any joint, in the circumferential direction of a cylindrical base material. CONSTITUTION:Each different coating liquid S1, S2 is supplied to distributing chambers 3A, 3B through feed pipes 4A, 4B. The coating liquid is distributed in the circumferential direction of a coating device body 1, and flows out uniformly and continuously in the circumferential direction from coating liquid outflow ports 9A, 9B through slits 8A, 8B. The coating liquid S1 which has flowed out of the outflow port 9A flows down on a liquid slide part 10, is bridges to an outside circumferential surface 13 of a cylindrical base material 12 from a hopper edge 11 and forms a bead. On the other hand, the coating liquid S2 which has flowed out of the outflow port 9B is bridged between the hopper edge 11 and the base material outside circumferential surface 13, as it is, formed beads and it is coated in a shape of two layers L1, L2 to the base material outside circumferential surface by both the coating liquid beads.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating method for an electrophotographic recording material substrate, etc., in which two or more coating liquids are simultaneously applied in a superimposed manner onto the circumferential surface of a substrate having an endlessly formed continuous circumferential surface, and the method. The present invention relates to an apparatus suitable for carrying out.

The present applicant previously filed a patent application in 1983-201 for a slide type coating device for simultaneous superimposition coating of electrophotographic recording media, etc.
No. 104 was also applied as an extrusion type in 1984-201.
No. 105 was proposed. Among these previously proposed technologies, the former sliding type has two or more coating liquid distribution chambers and coating liquid distribution slits connected to each of the coating liquid distribution chambers, each of which is connected to the coating liquid distribution chamber in a continuous manner. A coating liquid supply means is connected to each coating liquid distribution chamber, and is located inside each coating liquid distribution slit, and is connected to the bottom of each coating liquid discharge port of the coating liquid distribution slit. An endlessly formed continuous surface having a saliva sliding surface configured to terminate at a dimension slightly different from the outer dimension of the base material. This is a coating device that has a hopper edge that is larger than the base surface to be mirrored and extends downward from the end of the liquid slide surface.Coating by this device is carried out as follows. That is, when applying a substrate having an endlessly formed continuous circumferential surface such as an electrophotographic recording medium, the substrate is coated so as to surround the substrate and to maintain a gap between it and the surface 1j. A hopper is provided, and a coating liquid bead is formed in the gap to bridge the hopper edge facing the substrate circumferential surface and the substrate circumferential surface, and one coating liquid layer is connected to another coating liquid layer with respect to the bead. are applied continuously and simultaneously so that each individual layer is maintained in a well-defined one-layer relationship, and the substrate is continuously and simultaneously applied so that its circumferential surface intersects and is in contact with the coating liquid bead. The substrate is moved so that the peripheral surface of the substrate engages with the outer end of the overlapping layer of the coating liquid bead, and the bonding layer is simultaneously pulled out and applied overlappingly. This striped type superposition coating device is used, for example, when coating coating layers (for example, undercoat layer, charge generation layer, charge transport layer, etc.) of a recording medium such as an electrophotographic photoreceptor, or when coating a low viscosity coating liquid. However, when a high viscosity coating liquid flows down on the liquid slide part, the flow down is not carried out on a daily basis, and it is not easy to control the coating film thickness on the base material. In addition, it should be noted that when coating a high viscosity coating liquid on top of a low viscosity coating liquid, there will be an inconvenience that the required and uniform film thickness cannot be obtained on the circumferential surface of the substrate. The applicant found out.

On the other hand, in the latter extrusion type, two or more coating liquid distribution chambers and coating liquid distribution slits connected to each of the coating liquid distribution chambers are continuous, and the coating liquid is supplied to each coating liquid distribution chamber. A liquid supply means is connected to each coating liquid distribution chamber,
An outlet of the coating liquid 31e passing through each of the coating liquid distribution slits is provided between the coating surface and the coating surface formed with a dimension slightly larger than the outer dimension of the base material having an endlessly formed continuous circumferential surface. The coating surface is larger than the outer dimensions of the base material, and the coating device has a length in the coating direction necessary for coating. Coating by this device is carried out as follows. That is,
A substrate having an endlessly formed continuous surface is inserted into the hopper coating surface, and the substrate is moved vertically upward relative to the siJ marking device, and each coating film passes through the coating liquid distribution slit. The respective coating liquids extruded from the C outlet are applied directly onto the substrate peripheral surface simultaneously and in a superimposed manner. In this case, either direct coating or bead coating may be applied.

Contrary to the slide type device, this 44F push-out type 11 tatami coating device has no problem with applying a high viscosity coating solution, but it is difficult to apply a low viscosity coating solution. That is, since each coating liquid is directly pushed out from the coating liquid distribution chamber through each distribution slit onto the coating surface of the hopper and applied onto the crystallization surface, the supply pressure of the coating liquid has a large effect on the coating film thickness, resulting in low It has also been found that it is very difficult to control the supply pressure for viscous coating liquids.

In other words, high viscosity coating liquids are not suitable for the slide type, and low viscosity coating liquids are not suitable for the extrusion type, so when applying a combination of high and low viscosity coating liquids, neither of the above devices is suitable. It's inappropriate.

The present invention has been made in order to solve the drawbacks of the above-mentioned slide-slide type and extrusion type superimposed coating devices. An object of the present invention is to provide a coating device capable of coating a coating solution consisting of a combination of high viscosity and low viscosity so as to uniformly and stably obtain a necessary film thickness. The object and related objects will be made clear by the following description of the present specification. The method of the present invention for achieving the above object is applicable to a substrate having an endlessly formed continuous peripheral surface, such as an electrophotographic recording material substrate. In the method of applying @, two or more hopper devices are provided so as to surround the base material and maintain a gap between the base material and the surrounding surface, and in the gap, two or more hopper devices are provided so as to face the base material circumferential surface. Two or more layers of coating liquid beads are formed to bridge the hopper edge and the circumferential surface of the substrate, and the coating liquid is supplied to the uppermost layer of the beads by a slide, while the coating liquid is supplied to the lowermost layer of the beads. The coating liquid is supplied by extrusion, and both coating liquids are supplied continuously and simultaneously so that each individual bead layer is maintained in a distinct overlapping relationship, and Continuously moving the coating liquid bead so as to intersect with and contact the bottom of the coating liquid bead, the peripheral surface of the substrate engages the outer end of the superimposed layer of the coating liquid bead, and simultaneously draws out the bonding layer and simultaneously applies the superimposed layer. 'f
r, characterized.

In addition, an apparatus suitable for carrying out the above method has a hopper edge that cuts the circumferential surface of the substrate 115! A hopper device is arranged so as to surround the base material and maintain a gap between it and the circumferential surface of the base material that can bridge the bead made of two or more superimposed three-layer fabric liquid layers. , a coating liquid distribution chamber for supplying the coating liquid in a superimposed relationship in each of the superimposed layers of coating liquid beads is provided so as to surround the circumferential surface of the substrate; The hopper device that supplies the coating liquid to the upper layer bead pushes the coating liquid from the coating liquid distribution chamber through the coating liquid distribution slit to the liquid slide part,
A slide popper device is configured to continuously flow down the liquid over the slide portion to maintain a bead in the gap, while a hopper device for supplying the coating solution to the bottom layer build is connected to the coating solution distribution chamber. Through the coating liquid distribution slit
This is an extrusion hopper that directly extrudes to the hopper edge and maintains the bead in the gap.

Coating of two or more coating liquids in one tatami mat according to the present invention is preferably carried out using a coating device consisting of any combination of a slide-type hopper device and an extrusion-type popper device, and preferably a slide-type hopper device is installed at the top. Also, it is preferable to place an extrusion popper device at the bottom.

First, the upper Δ11 slide hopper device will be explained.

The slide popper device of this device has a continuous coating liquid distribution chamber and a coating liquid distribution slit connected to the coating liquid distribution chamber, and a coating liquid supply means that supplies the coating liquid to the coating liquid distribution chamber (chamber chamber). Connected to the liquid distribution chamber, the four bloods of the coating liquid distribution slit are connected to the liquid distribution chamber and are located in four of the coating liquid distribution slits. It has a liquid slide surface formed so as to terminate at a dimension slightly larger than the outer dimension of the halo having a surface, and has a swollen mating surface formed at the entrance Z. The base outer dimension is 05 to 1 mm. It is preferable to use a large popper edge with a length of 0.1 to 10 ml, preferably 0.5 to 4 ml, extending below the end of the liquid slide surface. In addition, the hopper edge 6iJ is located vertically below and beyond the end of the slide surface, within a range of up to 30 degrees from the end of the slide surface, on the side opposite to the halo. Preferably, it should extend vertically downwards and beyond it up to 2014 degrees.
If it exceeds VC, the crosslinking of the coating solution will not be strong enough, and the bead will become unstable, resulting in a good coating film.

Next, the extrusion hopper device according to the present device will be explained.

In this hopper system, the coating liquid distribution chamber and the coating liquid distribution slit connected to the coating liquid distribution chamber are continuous, and the coating liquid supply means for supplying the coating liquid to the coating liquid distribution chamber (chamber chamber) is connected to the coating liquid distribution chamber. The coating liquid distribution opening (1) is connected to the coating liquid distribution line (1), and the coating liquid outlet is formed in a dimension slightly larger than the outer dimension of the base material having an endlessly formed continuous circumferential surface. The hopper edge is provided between the hopper edge and the hopper edge.
5 to 1++m larger, preferably coating film thickness hOw
++ is in the range from 2h□tran to 4homm, and preferably has a length in the coating direction of 0.1 to 10mm, preferably 05 to 4mm. In addition, the hopper edge is vertically downward from its upper end and 3
It should be inclined toward the opposite side of the base material within a range of up to 0 degrees, and preferably extend vertically downward and within a range of up to 20 degrees. Also, if the slope of the hopper edge exceeds 30 degrees, the crosslinking of the coating liquid will be short.
The bead becomes unstable and it becomes difficult to obtain a good coating film.

In the present invention, each coating liquid supplied to the coating device is temporarily stored in each coating liquid distribution chamber, and the coating liquid is uniformly distributed to each coating liquid distribution slit connected to the chamber.
In order to uniformly distribute each of the coating liquids to each of the slits and to uniformly apply each of the coating liquids distributed to each of the slits to the substrate surface, each of the coating liquids for each of the coating liquid distribution slits is The pressure loss ratio of the distribution chamber is 80 or more for a sliding type, preferably 80 to 10o,
ooo, and in the case of an extrusion type, the pressure loss ratio ti is 40 or more, preferably 40 to 10.
Within the range of 0,000. If the pressure loss is less than 80 (slide type) or 40 (extrusion type), uniform distribution and application of the coating liquid may not be possible.
．． If 00Of, 1lfi is increased, it becomes necessary to enlarge the coating liquid distribution chamber or to lengthen the slit, which causes problems in terms of the structure of the apparatus.

The coating film formed on the fly using the coating device according to the present invention is formed by a coating liquid bead. That is, the layer of coating solution leaving the coating device is not directly applied to the substrate in a layer of the same thickness as when it left, but rather forms a bead and then transfers to the substrate. be. Therefore, the coating film formed by this bead of coating solution is not actually formed directly on the substrate from the coating device; instead, the coating device simply maintains the bead of coating solution, and the substrate is coated from the bead. be done.

The coating liquid bead is maintained by the coating liquid that has been pushed out of the coating liquid distribution slit (the coating liquid that has flowed down on the liquid slide section).
Otherwise, it is formed by crosslinking between the base material and the hopper edge. In coating with this bead, the thickness of the coating film applied on the halo moving across each bead is determined by the action of the bead, the speed at which the base moves, and the supply of coating liquid. Varies depending on speed, supply pressure, efficiency of hopper structure, etc.

It is preferable to use a pipe as the coating liquid supply means for supplying the coating liquid to the coating liquid distribution chamber in the coating apparatus of the present invention. A plurality of the above-mentioned vibrators etc. may be provided.

Further, a discharge pipe may be provided for discharging the coating liquid from the coating liquid distribution chamber, and in this case as well, two or more plurality of discharge pipes may be provided.

Coating by the coating apparatus of the present invention is performed as follows. That is, in a bead coating device that applies a coating liquid while moving a substrate having an endlessly formed continuous circumferential surface, a gap is formed so as to completely surround the circumferential surface of the substrate and allow the bead to be bridged by the coating liquid. A hopper edge is formed to maintain the hopper edge through which the coating solution distribution slit passes ii! An extrusion hopper device having a coating liquid outflow location for discharging the coating liquid is provided, and
A slide hopper device having a liquid sliding portion extending upward from the hopper edge is provided, and one coating liquid layer continuously and simultaneously supplies another coating liquid layer to the upper bead #J. , continuously moving said base so that its circumferential surface intersects and contacts said coating liquid bead, such that each individual layer is maintained in a well-defined tatami relationship;
The circumferential surface of the substrate engages the outer end of the superimposed layer of the coating liquid bead and simultaneously pulls out the bonding layer so that the coating is simultaneously superimposed.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below. Figures 1 (a) and (b) show the case of simultaneous two-layer coating in an apparatus most suitable for carrying out the coating method according to the present invention. FIG. 1(a) is a cross-sectional view showing the state of application to the base material of the example without a discharge port, and FIG. 2 is a coating device main body, and 2 is a hopper device for coating a coating liquid. 3A and 3B are coating liquid + 1 mouth,
A supply vibrator 4A supplies different coating liquids S1.82 to the distribution chambers 3A and 3B.

4B is the droplet liquid supply port 5A, 5B of the distribution chamber 3A, 3B.
6A and 6B in FIG. 1(b) are discharge pipes, which are connected to the coating liquid supply ports 5A and 5B at positions opposite to each other on a halo reference, and are connected to the distribution chamber 3AB marked AjJ. Formed discharge lower A.

Connected to 7B. aA, sBFim fabric liquid distribution slits are formed continuously so as to surround the outer periphery of the base material without having an end. 9A and 9B are coating liquid +1 mouth, 10 is a liquid slide part, and 11 is a hopper edge.

The respective coating liquids S1 and 52Fi are supplied to the distribution chambers 3A and 3B via supply vibrators 4A and 4Bi by pumps (not shown) or the like. Therefore, the coating liquids Sl and S2 are applied to the coating device main body (
Cylindrical) 1, distributed in the circumferential direction, Surin) 8A, 8B
The coating liquid S flows out uniformly and continuously in the circumferential direction from the coating liquid outlets 9A and 9B through the coating liquid S.
1 flows down on the liquid slide section 10 and reaches the hopper edge 1.
1 and the outer circumferential surface 13 of the cylindrical base material 12 to form a bead, while the coating liquid S flows out from the outlet 9B.
2 directly forms a bead by cross-linking between the hopper edge 11 and the outer circumferential surface 13 of the base material. Then, two layers LL, L are formed on the outer circumferential surface 13 of the base material by both coating liquid beads.
2.

In a preferred embodiment of the present invention, the inclination angle of the liquid sliding portion is in the range of 10 to 70 degrees with respect to the horizontal, more preferably in the range of 20 to 45 degrees. Since the distribution chambers and distribution slits are arranged seamlessly in the circumferential direction of the cylindrical base material, the applied coating film is seamless and uniform. Furthermore, since the coating thickness is determined by the amount of coating solution supplied and the speed of movement of the cylinder, it can be easily controlled, and at the same time, the coating speed can be much faster than in the dipping method.

In addition, in the present invention, as shown in FIG.
The coating liquid S is supplied to the distribution chambers 3A and 3B, and the discharge vibrators C and 6D are provided perpendicularly to the supply vibrators 4C and 4D, and the excess coating liquid S is transferred to the distribution chambers 3A and 3B.
It is also possible to discharge it outside B. Furthermore, distribution room 3A,
A plurality of supply/discharge pipes leading to 3B may be provided as necessary. In this case, the arrangement should be such that the flow of the coating liquid in the distribution chamber does not stagnate.Furthermore, the coating liquid discharged from the discharge vibrator should be stirred with a stirrer, for example, and then applied again. The coating liquid may be configured to be circulated so that it is supplied as a liquid to the supply pipe.

In the present invention, a valve is provided at the coating liquid outlet or discharge pipe for discharging all of the coating liquid in the coating liquid distribution chamber to regulate the amount of the coating liquid coming out at the IF, so that it can be used not only on the supply side but also on the discharge storage U. The liquid volume may also be adjusted.

The coating liquid according to the present invention is supplied from the supply pin, a part of which flows out onto the coating surface through the coating liquid distribution line, and the other part is discharged by the discharge vibrator, and the flow of this liquid is Although this is carried out continuously, the coating liquid may be supplied intermittently, such as by supplying the coating liquid at regular intervals in consideration of the aggregation time of the coating liquid.

In the coating device of the present invention, the cylindrical substrate can When the liquid applied to the circumference of the material is carried away by the hopper edge, a strong force acts to lift the Thibeed liquid upward due to the viscosity of the liquid, causing a gap between the cylindrical base material and the hopper edge. The formed beads may not be able to exist stably, and in order to prevent this, as shown in FIG. A decompression chamber 11 is provided below the liquid bead to cooperate with the bead and the cylindrical base material 12, and a gas discharge pipe 15f communicating with the decompression chamber 14 is provided to maintain the inside of the decompression chamber 14 at a negative pressure from the ambient air pressure. A coating device that performs coating under reduced pressure can also be suitably used.

If this device is used, nitrogen gas is exhausted from the inside of the decompression chamber 14 which includes the bead and a part of the surface of the cylindrical base material 12 as part of the wall below the bead through the exhaust pipe 15, and the internal pressure of the decompression chamber 14 is lowered from the atmospheric pressure. (preferably 1 to 3 columns of water below atmospheric pressure)
It is controlled so that the coating is maintained at a low level (in the range of 00m+n water column). Therefore, it is possible to prevent uneven coating due to variations in coating speed or variations in the gap between the cylindrical drum hopper edge and the like.

Although the embodiments of the present invention have been described above in which two coating liquids are applied simultaneously in a superimposed manner, it is also possible to apply three or more coating liquids simultaneously in a superimposed manner by appropriately combining these embodiments. In this case, the combination of hopper devices may be, for example, a combination of two slide type (!-) and one extrusion type, a reverse combination of hopper devices, and a combination of four or more hopper devices. Also, the combination of the slide mold and the extrusion mold is arbitrary, but the combination is
It is desirable to configure the moon-tube apparatus in accordance with the viscosity of the coating liquid, that is, a high viscosity coating liquid is applied by an extrusion hopper, and a low viscosity coating liquid is applied by a squid hopper. Examples of the above three or more coating layers include a subbing layer of S7, a charge generation layer, a charge transport layer, etc. used in the production of an electrophotographic photoreceptor.
No. 1-90827, No. 57-67934-kun, No. 57-
See No. 179857.

) can also be applied simultaneously.

The apparatus according to the present invention is used for manufacturing recording drums such as electrophotographic photoreceptors, electrostatic recording materials, which require a thin and uniform coating film, and for manufacturing recording materials such as electrophotographic photoreceptors, coatings on the surface of rollers, and outer peripheral surfaces of endless strips, etc. It is used as a coating device on the outer surface of a substrate having an endless continuous surface.The application is not limited to the following: The base material itself may be moved, or the coating device may be moved, and the base material (cylindrical drum) vi-
May be rotated. The hopper coating surface and cylindrical base material are
Since they are arranged with a certain gap, they do not damage the base material (cylindrical drum).

As described above, the coating device of the present invention is capable of uniformly and stably coating two or more coating liquids without damaging the continuous circumferential surface of an endlessly formed base material. Even coating liquids having different viscosities can be applied to obtain a uniform film N, the film thickness can be easily controlled, and the productivity is rapid and high.

In the present invention, in order for the coating liquid to stagnate uniformly in the circumferential direction from the addition ports 9A and 9B, in the slide hopper device, the distribution chamber resistance (Pc) and the time when the coating liquid flows through the coating liquid distribution slit are required. The slit resistance (Ps) is P S /P
c≧80, preferably 100 to 100,000
In the extrusion hopper device, the distribution chamber resistance (Pc) and the coating liquid distribution slit? By maintaining the relationship between the slit resistance (Ps) during flow and Ps/Pc≧40, preferably within the range of 40 to 100.000, it is possible to apply the coating liquid stably and uniformly. It is.

The above relationship holds true for both single layer and Ren9 tatami coating systems, and in the case of multilayer coating, it depends on the viscosity of the melted or dispersed coating solution, the coating solution supply rate, and the supply pressure. It is only necessary that the distribution window resistance (Pc) and the slit resistance (Ps) are determined respectively.

[Brief explanation of the drawing]

FIG. 1 shows an example of a 1J'' case of two-layer simultaneous coating using an apparatus that is most suitable for carrying out the coating method according to the present invention, (a) is one without a discharge port, (b) ) is a cross-sectional view showing the state of coating on a base material with a discharge port, FIG. 2 is a plan view showing another embodiment of the present invention, and FIG. 3 is a cross-sectional view showing still another embodiment of the present invention. In the figure, 1 is the coating surface main body, 2 is the hopper device,
3A and 3B are coating liquid distribution chambers, 4A and 4B are supply pipes,
5Δ, 5B are Rippu liquid supply ['', 6A, 6B are cedar [out pipe, ? A and 7B are coating liquid discharge ports, 8A and 811 are coating liquid distribution slits, 9 A and 9B are coating liquid outlet ports, 1
0 is a liquid slide part, 111j is a potsper edge, 12 is a base material, Fi, 81. S2 indicates each coating liquid. Applicant: Konishi Roppo Shin Kogyo Co., Ltd. Agent: Nobuaki Sakaguchi (1 person) Figure 3

Claims (1)

[Scope of Claims] (11) In a method of applying a substrate having an endlessly formed continuous circumferential surface, such as an electrophotographic recording material substrate, a continuous circumferential surface is formed so as to surround the substrate. Two or more hopper devices coat the gold film so as to maintain a gap between the two or more hopper devices, and in the gap, two or more layers of coating liquid beads are formed to bridge the gap between the potsuperan facing the circumferential surface of the substrate and the circumferential surface of the substrate. The coating liquid is supplied to the uppermost bead among the beads by sliding, while the coating liquid is supplied to the lowermost bead by extrusion, and both coating liquids are supplied continuously and simultaneously. The base material is continuously moved so that its circumferential surface intersects and touches the front 5-pied coating liquid bead, so that each individual bead layer is maintained in a clear overlapping relationship. A method for coating an electrophotographic recording material substrate, etc., characterized in that the circumferential surface engages with the outer end of the superimposed layer of the coating liquid bead to simultaneously pull out the bonding layer and simultaneously apply the top layer. (2) In a bead coating device that applies a liquid while moving a substrate having an endlessly formed continuous circumferential surface, such as an electrophotographic recording material substrate, a hopper elan is applied so as to surround the circumferential surface of the substrate. A hopper device is arranged to maintain a gap between the coating liquid bead and the coating surface so as to maintain a gap capable of bridging the bead consisting of two or more superimposed coating liquid layers. Each of the layers is provided with a coating liquid distribution chamber that supplies the coating liquid in a superimposed relationship so as to surround the circumferential surface of the substrate, and supplies the coating liquid to the uppermost layer bead of the superimposed coating liquid layer. hopper device u, ni
A slide hopper device is used to push out the coating liquid through a distribution slit to the liquid slide section and to continuously flow the liquid down over the slide section to maintain the entire bead in the gap. The hopper device for supplying the ram cloth liquid to the lower layer bead is an extrusion hopper that directly extrudes the liquid from the coating liquid distribution chamber to the hopper edge through the coating liquid distribution slit and maintains the bead in the gap. Coating device for electrophotographic recording material substrate, etc., (3)
A coating liquid supply port for supplying the coating liquid to a slide type and/or push type coating liquid distribution chamber is provided, as well as a coating liquid discharge port for discharging the coating liquid to the outside of the coating liquid distribution chamber. A coating apparatus for electrophotographic recording material substrates, etc., according to claim 2.