JP2005331987A - Method for drying cylindrical base, and drying device for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a superior coating application method which eliminates fluctuations in the film thickness of a coating film of a cylindrical base, and to provide a coating applicator for the same. <P>SOLUTION: The coating application method comprises supplying a coating liquid from the inlet aperture of a coating liquid distribution slit forming an annular slit for distributing the coating liquid; making the coating liquid to flow out of an outlet aperture of the liquid distribution slit disposed inside the inlet aperture; making the coating liquid to flow out onto a hopper face inclining to a lower side inside the outlet aperture and extending up to an annular end in proximity to the outer peripheral surface of the cylindrical base; continuously supplying the coating liquid between the outer peripheral surface of the cylindrical base and the annular end of the hopper face; and forming a coating film, by applying the coating liquid to the outer peripheral surface of the cylindrical base. The coating application method, comprising passing of the coating liquid to the annular end of the hopper face satisfies the condition: 1.0<HRD<10, when the roundness at the annular end of the hopper surface is defined as HRD (μm). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for drying a cylindrical substrate (also referred to as a photosensitive drum) and a cylindrical substrate drying apparatus. More specifically, a cylindrical base material coated with a coating film on the outer peripheral surface is provided with a ring-shaped circumferentially uniform suction member concentrically on the outer periphery and inserted from an insertion opening of the cylindrical member. The present invention relates to a drying method and apparatus for a cylindrical base material that sucks a gap portion between the cylindrical base material surface and the inner surface of the cylindrical member concentrically when the air is inserted to generate an air flow and promotes drying of a coating film. Such a drying method and its apparatus are preferably used in the production of a photosensitive drum for an electrophotographic apparatus, for example.

  As a drying apparatus for a cylindrical base material immediately after coating, a technique for accelerating drying by directly blowing air to the cylindrical base material after coating is disclosed (see Patent Document 1 and Patent Document 2). The method of blowing the air has a drawback in that the air collides with the coating film, so that the coating film is likely to be repelled or uneven in film thickness.

  Moreover, the technique which accelerates | stimulates drying by inhalation using a draft is disclosed (refer patent document 3). In the method of sucking air, the film thickness is likely to be uneven due to the turbulent airflow generated in the draft. In particular, in these methods, the film thickness unevenness significantly increases as the viscosity of the coating solution decreases.

As these improvements, the applicant has already made a cylindrical member in which the cylindrical base material can be inserted in an electrophotographic photosensitive member drying apparatus for drying the cylindrical base material coated on the surface of the cylindrical base material. A ring-shaped circumferentially uniform suction member is provided concentrically on the outer periphery of the intermediate portion, and a gap between the cylindrical base material surface and the inner surface of the concentric cylindrical member is sucked when the cylindrical base material is inserted. The drying apparatus which raises airflow and accelerates | stimulates drying of a coating film is disclosed (refer patent document 4). However, it has been found that what is in the center of the cylinder still has a strong wind effect on the undried.
JP 59-73074 A JP 62-44771 A Japanese Patent Laid-Open No. 62-4470 JP-A-6-308747

As a result of improvement studies, a ring-shaped circumferentially uniform and concentric suction member is provided on the outer periphery of a cylindrical member that allows a cylindrical substrate coated with a coating film to be inserted from the insertion opening, and the cylindrical substrate is inserted. In the drying apparatus that sucks the gap between the cylindrical base material surface and the inner surface of the cylindrical member concentric when inserted into the opening to generate an air flow, and accelerates the drying of the coating film, the total length of the cylindrical member is L ₀ , when the distance to the suction portion of the suction member from the insertion opening of the tubular member and the L _1, from the center of the entire length of the tubular member, by a distance to the suction of the suction member upward, particularly thin film coating In the case of, it turned out that it becomes better.

  The object of the present invention is to uniformly and rapidly evaporate the coating solvent without adversely affecting the coating film immediately after coating, and to suppress the generation of turbulence near the coating film surface during drying as much as possible, and in the vicinity of the coating film It is an object of the present invention to provide a method and apparatus for drying a cylindrical base material that can remove a solvent vapor accumulated in the substrate and apply a uniform and stable coating film.

The above object can be achieved by any of the following. That is,
(1) A cylindrical base material coated with a coating film on its outer peripheral surface is provided with a ring-shaped circumferential uniform suction member concentrically on the outer periphery and inserted from the insertion opening of the cylindrical member, and the cylindrical base material is inserted. In the method of drying a cylindrical base material that sometimes sucks a gap between the cylindrical base material surface and the inner surface of the cylindrical member concentric to cause an air flow, and accelerates drying of the coating film,
When the total length of the cylindrical member is L ₀ , and the distance from the insertion opening of the cylindrical base material of the cylindrical member to the suction member is L ₁ ,
0.5 <L ₁ / L ₀ <1.0 [1]
A method for drying a cylindrical substrate characterized by satisfying the following conditions:

(2) Furthermore, when the total length of the cylindrical member is L ₀ , and the distance from the insertion opening of the cylindrical base material of the cylindrical member to the suction member is L ₁ ,
0.6 <L ₁ / L ₀ <0.9 [2]
The cylindrical substrate drying method according to (1), wherein the following condition is satisfied.

(3) A ring-shaped circumferentially uniform and concentric suction member is provided on the outer periphery of the cylindrical member that allows the cylindrical substrate coated with the coating film to be inserted from the insertion opening, and the cylindrical substrate is In the cylindrical substrate drying apparatus that sucks a gap portion between the cylindrical base material surface and the inner surface of the cylindrical member concentric when inserted into the insertion opening to generate an air flow, and accelerates drying of the coating film,
When the total length of the cylindrical member is L ₀ and the distance from the insertion opening of the cylindrical member to the suction portion of the suction member is L ₁ ,
0.5 <L ₁ / L ₀ <1.0 [1]
A cylindrical substrate drying apparatus characterized by satisfying the following conditions:

(4) Furthermore, when the total length of the cylindrical member is L ₀ and the distance from the insertion opening of the cylindrical member to the suction portion of the suction member is L ₁ ,
0.6 <L ₁ / L ₀ <0.9 [2]
The cylindrical substrate drying apparatus according to (3), wherein the following condition is satisfied.

  Explaining the above formula [1], the generation of turbulence near the surface of the coating film immediately after coating is almost eliminated, and particularly in the thin film coating with a dry film thickness of 0.5 μm or less, without adversely affecting the pressure coating film, It is possible to evaporate and remove the solvent uniformly and rapidly and complete drying, and it is possible to efficiently produce a high-quality electrophotographic photosensitive drum. If the lower limit is exceeded, it will be affected by strong winds during drying. A more preferable range is the range shown in the formula [2].

  According to the present invention, by setting the position of the suction member with respect to the cylindrical member to the position of the present invention, generation of turbulence near the surface with respect to the coating film immediately after coating is almost eliminated, without adversely affecting the coating film, It is possible to evaporate and remove the solvent uniformly and rapidly and complete drying, and it is possible to efficiently produce a high-quality electrophotographic photosensitive drum.

  1 is a front view showing the overall configuration of the continuous coating apparatus, FIG. 2 is a sectional view of the coating means of FIG. 1, and FIG. 3 is a perspective view of the coating means of FIG.

  In FIG. 1, the supply means 140 supplies the cylindrical substrate 1 to a predetermined position vertically below the application means and pushes it upward. The loading guide member 141 is a guide member for loading the cylindrical base material 1, and the table 142 rotates the cylindrical base material 1. The driving means 143 is provided on the vibration isolation table 181 and drives the table 142. Further, the elevating member 144 is provided on the vibration isolator 182 and elevates and lowers the cylindrical base material 1 in the vertical direction.

  The conveyance means 120 grasps the outer peripheral surface of the supplied cylindrical base material 1 and aligns the cylinder axis, and vertically pushes it up from the bottom and conveys it. The ball screw 124 is rotated by the motor M3 provided on the anti-vibration table 183, the vertical moving means 123 is moved up and down, and the gripping means 121 is moved. Similarly, the ball screw 124 is rotated by the motor M4, the vertical movement means 123 is moved up and down, and the gripping means 122 is moved.

  The positioning means 20 is of an air bearing type, and is blown from a blowing nozzle such as air to align the cylindrical substrate 1 with the center of the annular application portion of the application means.

  The coating unit 30 applies a coating solution to the cylindrical base material 1. Details will be described with reference to FIG.

  The drying device 150 is a drying device formed in an annular shape, and is fixed to the device main body 170. The cylindrical coating 1 is dried on the coated film.

  The separation and discharge means 160 separates and discharges one by one from the plurality of stacked cylindrical base materials 1 that have been dried and vertically conveyed. The shaft body 162 of the vertical moving robot stage 161 has an upper chuck 163 and a lower chuck 164, which chucks the cylindrical substrate 1 and drives it up and down by the air cylinder 165.

Next, the coating means 30 will be described with reference to FIG. 2. The liquid feed pump 6 serving as the coating liquid supply means supplies the coating liquid 11 in the coating liquid tank 5 to the coating liquid supply port 6a. The coating liquid distribution chamber 7 is provided so as to surround the cylindrical bases 1a, 1b,... And stores the coating liquid 11 supplied by the liquid feed pump 6. The coating liquid distribution slit 8 puts the coating liquid supplied from the coating liquid supply means through the annular inlet opening and flows out from the annular outlet opening 9 of the coating liquid distribution slit 8 inward from the inlet opening. Distribute 11. The conveying means 120 grips the cylindrical base materials 1a, 1b,... With respect to the hopper surface 4 and vertically moves them upward. The roundness HRD (μm) of the annular end portion 4b of the hopper surface is in the range of 1.0 <HRD <10. The ten-point average surface roughness R _Z (μm) of the annular end 4b of the hopper surface is in the range of 0.1 <R _Z <5.0. Moreover, the cylindrical base material maximum vibration width VR in the application part is in a range of VR = 40 μm or less. The hopper surface 4 is inclined inward and downward from the annular outlet opening 9 and extends to the annular end 4b close to the outer peripheral surface of the cylindrical substrates 1a, 1b,.

  A gap GP (μm) between the cylindrical base material and the annular end portion of the hopper surface is in a range of 50 <GP <500. If it does not fall within this range, a stacking error fluctuation is applied in the vertical direction, and it becomes impossible to apply a large number of continuous coatings by rubbing the coater or positioning part. The viscosity V (millipascal · second) of the coating solution is in the range of 1.0 <V <300. The roundness CRD (μm) of the cylindrical substrate 1 is in the range of CRD <30. The cylindrical substrates 1a, 1b,... May be hollow drums, for example, aluminum drums, plastic drums, or seamless belt type cylindrical substrates. Thin film coating refers to those having a wet film thickness of 20 μm or less.

  Here, a method of applying the cylindrical substrate will be described. In the supplying step, the cylindrical base material 1 having entered the predetermined specification value is placed on the table 142. The cylindrical substrate 1 reaches the YY axis by the rotation of the table 142. At this time, the elevating member 144 pushes the cylindrical base material 1 upward from below. When the push-up by the elevating member 144 is completed, the shock absorbing mechanism acts, and it is preferable to eliminate the shock at the time of joining with the cylindrical base material 1. The cylindrical base material 1 is carried to the place of a conveyance process.

  In the transporting process, the outer peripheral surface of the cylindrical base material 1 has two sets of gripping portions 121 and 122 that can be pressed against and separated from each other and can move vertically and vertically. Transport.

  In the positioning step, the cylindrical substrate 1 is accurately positioned by the air cylinder method, and the positioned cylindrical substrate 1 is transferred to the coating step.

  In the coating process, the coating liquid 11 having entered a predetermined specification value in the coating liquid tank 5 is supplied to the coating liquid supply port 6 a by the liquid feed pump 6. The coating liquid 11 is stored in the coating liquid distribution chamber 7 and then flows from the inlet opening of the coating liquid distribution slit 8 to the outlet opening 9. Then, the coating liquid 11 flows on the hopper surface 4 that is inclined inwardly from the outlet opening 9 and extends to the annular end portion close to the outer peripheral surface of the cylindrical base material 1a, 1b,.

  The cylindrical base materials 1a, 1b,... Are moved vertically upward with respect to the hopper surface 4 while continuously between the outer peripheral surface of the cylindrical base materials 1a, 1b,. A coating liquid 11 is supplied and coated on the outer peripheral surfaces of the cylindrical base materials 1a, 1b,.

  In the drying step, the coated cylindrical substrate 1 is dried through the drying apparatus. Furthermore, in the separation / discharge step, the cylindrical substrate 1 is separated and discharged.

  Next, FIG. 4 is a structural cross-sectional view of the simultaneous multilayer coating apparatus, which is an apparatus for simultaneously applying the multilayer coating apparatus. Members that are mechanically and functionally the same as those in FIG.

  In FIG. 4, the coating liquid supply means supplies the coating liquid 111 having entered the specification values to the coating liquid distribution slit 81 by the liquid feed pump 61. The coating liquid distribution slit 81 flows out and distributes the coating liquid 111 to the outlet opening 9 that surrounds the outer peripheral surface of the cylindrical base material 1a, 1b,.

  The simultaneous multi-layer coating method will be described. The coating liquid 11 that has entered the specification values is supplied to surround the outer peripheral surfaces of the cylindrical substrates 1a, 1b,. To do. And it is made to flow to the hopper surface 4 which entered the said specification value close | similar to the outer peripheral surface of cylindrical base material 1a, 1b ... from the exit opening part 9. FIG.

  Further, the coating liquid 111 is supplied to distribute the coating liquid 111, surround the outer peripheral surfaces of the cylindrical base materials 1 a, 1 b,. Flow from the outlet opening 91 to the hopper surface 4 close to the outer peripheral surface of the cylindrical base material 1a, 1b,.

  The cylindrical base materials 1a, 1b,... Are moved vertically upward with respect to the hopper surface 4. The coating liquid 11 that has flowed through the hopper surface 4 is coated on the outer peripheral surface of the cylindrical base material 1a, 1b,... To form the coating films 2 and 2A simultaneously.

  Since coating is performed as described above, an excellent coating film with no variation in film thickness and no bead breakage is formed.

  Next, FIG. 5 is a configuration cross-sectional view of a sequential multilayer coating apparatus, which is a coating apparatus for sequential multilayer coating in which coating apparatuses are arranged vertically. Members that are mechanically and functionally the same as those in FIG.

  In FIG. 5, the coating liquid supply means supplies the coating liquid 112 having entered the specification values to the coating liquid distribution slit 82 by the liquid feed pump 62. The coating liquid distribution slit 82 distributes the coating liquid 112 so as to surround the outer peripheral surface of the cylindrical base material 1a, 1b,. The hopper surface 42 having entered the specifications extends from the outlet opening 92 to the annular end 42b close to the outer peripheral surface of the cylindrical base material 1a, 1b,.

  Here, the sequential multi-layer coating method will be described. The coating liquid 11 having entered the specification values is supplied to distribute the coating liquid 11 and the outer circumferences of the cylindrical substrates 1a, 1b,. It surrounds the surface and flows out to the outlet opening 9. The flowing coating liquid 11 is allowed to flow from the outlet opening 9 to the hopper surface 4 close to the outer peripheral surface of the cylindrical base material 1a, 1b. The cylindrical base materials 1a, 1b,... Are moved in the vertical direction upward with respect to the hopper surface 4 having entered the specification values. The coating liquid 11 is applied to the outer peripheral surfaces of the cylindrical substrates 1a, 1b,... That move the coating liquid 11 flowing on the hopper surface 4 upward.

  The coating liquid 112 is supplied to distribute the coating liquid 112 that has entered the specifications, surrounds the outer peripheral surface of the cylindrical base material 1a, 1b,... That has entered the specifications, and flows out to the outlet opening 92. The flowing coating liquid 112 is allowed to flow from the outlet opening 92 to the hopper surface 42 that has entered the above specification values close to the outer peripheral surface of the cylindrical base material 1a, 1b.

  The cylindrical base materials 1a, 1b,... Are moved vertically with respect to the hopper surface. The coating liquid 112 that has flowed through the hopper surface 4 is coated on the outer peripheral surface of the cylindrical base material 1a, 1b,... To form a coating film 2A.

  The sequential multi-layer coating apparatus is provided with two coating heads 32. However, another coating head may be provided above the coating head 32 and the coating head may be three sequential multi-layer coating apparatuses.

  FIG. 6 is a longitudinal sectional view of the positioning device and the vertical coating device. The vertical applicator is fixed below the vertical applicator 10A and a vertical applicator 10A for applying the coating liquid 2A onto the cylindrical substrates 1a and 1b that are vertically stacked along the center line O. The positioning device 20 includes a cylindrical base material, a drying hood 30A installed above the vertical coating device 10A, and a support device 40A fixed to the lower portion of the positioning device 20.

  Inside the vertical coating apparatus 10A, a coating head 30 that surrounds the outer periphery of the cylindrical substrate 1a and coats the coating liquid, a tapered coating liquid outlet (coating liquid slide surface) 12A adjacent to the coating head 30, and a horizontal A coating liquid distribution slit 13 </ b> A and a coating liquid distribution chamber 14 </ b> A that form a narrow coating liquid passage in the direction are formed. A coating liquid supply pipe 16A is connected to the coating liquid distribution chamber 14A, and the coating liquid is supplied by a pressure feed pump (not shown).

  In the coating method using the vertical coating apparatus 10A, the vertical coating apparatus 10A is fixed, and the cylindrical base 1a is moved upward in the direction indicated by the arrow along the center line O from the upper end of the cylindrical base 1a. Application is carried out according to 30.

  A predetermined amount of coating liquid is stably fed into the vertical coating apparatus 10A by a pressure feed pump, and passes through a coating liquid supply pipe 16A, a coating liquid distribution chamber 14A, a coating liquid distribution slit 13A, and a coating liquid outlet 12A. It is supplied to the coating head 30 and a coating solution is applied to the surface of the cylindrical substrate 1a to form a photosensitive layer.

  An annular drying device 150 is fixed to the upper part of the vertical coating device 10A. The photosensitive layer on the cylindrical substrate formed by the vertical coating apparatus 10 </ b> A gradually dries the coating solution 2 </ b> A applied while passing through the drying apparatus 150. Drying is performed by releasing the solvent contained in the coating solution to the outside.

  A cylindrical base material positioning device 20 is fixed to the lower portion of the vertical coating device 10A. FIG. 7A is a cross-sectional view of the cylindrical base material positioning apparatus in FIG. 6 taken along the line P-P (air supply part), and FIG.

  The cylindrical base material positioning device 20 includes an outer cylinder member 21A and an inner cylinder member 22A fixed inside the outer cylinder member 21A. The outer cylinder member 21A and the inner cylinder member 22A are provided with a plurality of air supply ports 23A and a plurality of exhaust ports 26A penetrating both members. The plurality of air supply ports 23A are connected to an air supply pump 29A, and fluid such as air is pumped.

  As shown in FIGS. 6 and 7A, the outer cylinder member 21A is provided with four air supply openings 23A in the horizontal direction and further arranged in a plurality of stages (five stages in the figure) in the vertical direction. . A horizontal groove 24A is perforated on the inner peripheral surface of the outer cylindrical member 21A, and a horizontal flow path is formed between the outer cylindrical member 22A and the outer peripheral surface of the inner cylindrical member 22A. The individual air supply ports 23A communicate with each other. The inner cylinder member 22A has a hole having twelve discharge ports 25A in the horizontal direction. The discharge port 25A faces the outer peripheral surface of the cylindrical base material 1 with a gap G therebetween. The gap G is 20 μm to 3 mm, preferably 30 μm to 2 mm. If the gap G is smaller than 20 μm, the cylindrical base material 1 is likely to be damaged by coming into contact with the inner cylindrical member 22 </ b> A with slight vibration of the cylindrical base material 1. Further, if the gap G is larger than 3 mm, the positioning accuracy of the cylindrical substrate 1 is lowered. The discharge port 25A is a small nozzle having a diameter of 0.01 to 1.0 mm, preferably 0.05 to 0.5 mm.

  As shown in FIGS. 6 and 7 (b), exhaust ports 26A are horizontally arranged in four radial directions through the outer cylinder member 21A and the inner cylinder member 22A, and are further provided in a plurality of stages (not shown). (5 levels). The exhaust ports 26A are alternately arranged with the air supply ports 23A in the vertical direction. A vertical groove 27A is formed in the inner peripheral surface of the inner cylinder member 22A, and communicates with the multiple-stage exhaust ports 26A.

  The inner peripheral surface of the lower part of the inner cylinder member 22A is lined with Teflon (registered trademark), which is a fluororesin material, and has a tapered surface 28A with the entrance side widened. The tapered surface 28A is, for example, a conical surface having an axial length of 50 mm and a one-side inclination angle of 0.5 mm. The taper ratio of the tapered surface 28A is 0.005 to 0.2, preferably 0.01 to 0.1. Providing this tapered surface 28A is effective because the cylindrical base material 1 is regulated when the cylindrical base material 1 moves horizontally or inclines and enters the positioning device 20. By providing this tapered surface 28A, when the cylindrical base material 1 enters the inner cylinder member 22A, the tip of the cylindrical base material 1 is prevented from coming into contact with the inner peripheral surface of the inner cylinder member 22A. . In another example, the cylindrical member 22A itself is Teflon (registered trademark) which is a fluororesin material. The introduction part is most easily contacted, but even if it comes into contact, the introduction member is made of a fluororesin (relatively soft and slippery) so that it is hardly damaged.

  The fluid pumped from the air supply pump 29A is introduced into the outer cylinder member 21A from the plurality of air supply ports 23A, and is discharged from the plurality of discharge ports 25A through the horizontal grooves 24A. 1b) and a uniform fluid film layer are formed. The discharged fluid is discharged out of the apparatus through the plurality of exhaust ports 26A through the vertical groove 27A.

  The fluid supplied to the air supply port 23A is preferably air or an inert gas such as nitrogen gas. The fluid is preferably a clean gas of class 100 or higher according to JIS standards.

Moreover, the amount of fluid per minute supplied to the air supply port 23A is preferably 0.1 to 50 m ³ / min. If the amount of fluid is less than 0.1 m ³ / min, the positioning accuracy of the cylindrical base material 1 is extremely deteriorated. If the amount of fluid is greater than 50 m ³ / min, the effect of the air volume is strong and the stacked cylinders The substrate 1 vibrates and the liquid film becomes non-uniform. For this reason, the amount of fluid per minute is particularly preferably 0.2 to 20 m ³ / min. Here, if the amount of fluid to be regulated is not regulated by the fluid pressure and not controlled by the fluid pressure, an influence on the liquid film immediately after coating (film thickness unevenness, etc.) occurs. The amount of fluid per minute was measured at the inlet of the air supply port 23A of the positioning device 20. In addition, it is preferable that the fluid amount per minute supplied to the plurality of air supply ports 23A is the same as the flow rate of the air supply port 23A in the axial direction or a higher flow rate from below. Two or more of the positioning devices 20 may be connected and used as shown in FIGS.

  Various devices such as a slide hopper type, an extrusion type, a ring coater, and spray coating are used as the vertical coating device connected to the positioning device.

  FIG. 9 is an overall layout diagram of the drying apparatus. The overall arrangement will be described. The coater 30 is a coater for coating, and the cylindrical substrate 1 is a hollow aluminum drum of an electrophotographic photoreceptor substrate. Cylindrical base material 1 is piled up and down below, and is conveyed in the direction of an arrow (upward). The cylindrical base material 1 applied by passing through the coater 30 is conveyed as it is, passes through the drying device 150 of the present invention, and removes the solvent of the coating film 2.

  FIG. 10 is a partially cut perspective view of the coater, and FIG. 11 is a cross-sectional view showing a state where the cylindrical base material and the coater are applied. 10 and 11, the coater 30 applies a coating solution to a cylindrical base material. The coating liquid flowing from the coating liquid distribution chamber 7 through the coating liquid distribution slit 8 and flowing down the hopper surface 4 forms the coating film 2 on the drum surface of the cylindrical substrate 1.

  FIG. 12 is a sectional view of the drying apparatus. In FIG. 12, a drying device 150 includes a suction slit member 16B having a suction slit 16B, a suction chamber 12B, and a suction nozzle 15B. .

When the total length of the cylindrical member is L ₀ , and the distance from the insertion opening of the cylindrical base material of the cylindrical member to the suction member is L ₁ , 0.5 <L ₁ / L ₀ <1.0 is there. More preferably, 0.6 <L ₁ / L ₀ <0.9.

  Then, suction is performed from a plurality of suction nozzles 15B, suction air that has been made uniform in the circumferential direction by the suction chamber 12B that is uniform in the circumferential direction and the suction slit 16B that is uniform in the circumferential direction flows, and further, the suction slit member 18B, For the drying shown in 14B, the disturbance of the air flow between the inner diameter surfaces of the upper and lower cylindrical members 10B and 9B and the outer peripheral surface of the coated cylindrical base material 1 is suppressed in the buffer space 13B. The air flow of uniform suction air is created. The coated film is dried by conveying the coated cylindrical substrate 1 in the direction indicated by the arrow to the drying zone.

  In this drying device, drying is promoted by the air flowing between the double cylinders, but if the gas concentration of the solvent evaporating from the coating film becomes too high, the drying efficiency will be reduced. In order to prevent the gas concentration of the solvent from becoming saturated, it is necessary to avoid the air volume (wind speed), the cylinder length, and the suction portion at the cylinder length from the center.

  The evaporation rate of the solvent of the coating film depends on the vapor pressure of the solvent, the temperature, the vapor density of the atmosphere, and the like. Among them, the vapor pressure is a physical property specific to the solvent, and the air temperature is determined by the temperature of the coating chamber. Therefore, the vapor density may be lowered to promote drying. By applying an air stream to the coating film, it is possible to reduce the vapor density and promote air drying.

  When the evaporation rate of the solvent immediately after coating is high, the coating film is easily affected by wind. As the drying progresses to some extent, the influence of the wind is reduced, and at the same time, the temperature of the cylindrical substrate is lowered by the latent heat of evaporation. It is desirable to increase the air volume in order to correct the temperature drop of the cylindrical base material by flowing more air at room temperature and to reduce the gas concentration of the solvent in the cylinder.

  In order to uniformly dry the coating film of the cylindrical base material, it is required that the suction speed in the circumferential direction is uniform. If the wind speed differs in the circumferential direction, the drying speed is different in the circumferential direction, causing problems such as mottled patterns on the coating film, but in order to control the circumferential wind speed (air volume), The purpose is achieved by giving a uniform pressure loss in the circumferential direction.

  Using the suction chamber 12B having a ring-shaped capacity and a uniform suction slit 16B in the circumferential direction shown in the partially broken perspective view of the suction member provided with the suction slit of FIG. The suction slit 16B uniform in the circumferential direction was used as a pressure loss member.

  Further, as a means for uniform suction in the circumferential direction, a punch plate 19B as shown in a partially broken perspective view of the suction member provided with the punch plate of FIG. 14 or a mesh of FIG. 15 is provided instead of the circumferential uniform slit. The object can also be achieved by using a mesh 20B as shown in the partially broken perspective view of the suction member. In the present invention, changing the air volume and speed in the cylinder can be easily handled by changing the inner diameter and length of the cylindrical members 9B and 10B as the rectifying cylinder shown in FIG.

Next, the present invention will be described by way of examples, but the present invention is not limited to these examples.
(Example 1)
The experimental conditions are as follows.
a) The lengths of the cylindrical members 9B and 10B are both 400 mm and the outer diameter is 80 mm.
b) The moving speed of the cylindrical substrate is 20 mm / S.
c) Distance between coater and dryer: 200mm
d) Measurement location: measured at the end of the cylindrical member e) Coating solution: UCL-1 coating solution composition shown below f) Dry film thickness: 0.1 μm
UCL-1 coating liquid composition Copolymer nylon resin (CM-8000, manufactured by Toray Industries, Inc.)
Methanol / n-butanol = 10/1 (Vol ratio)
These experiments were performed with the apparatus shown in FIGS. 9, 10, 11, and 12, and the inner diameters and wind speeds of the cylindrical members 9B and 10B were changed. The results are shown in Table 1.

As shown in Table 1, within the range of the present invention, it is not affected by wind strong against drying, and the coating is uniform and good.
(Example 2)
It applied so that it might become a dry film thickness of 0.2 micrometer like (Example 1) except having used the CGL-1 coating liquid composition shown below.
CGL-1 coating solution composition Y-type titanyl phthalocyanine (CGM-1)
Silicone resin (KR-5240, manufactured by Shin-Etsu Chemical Co., Ltd.)
t-Butyl acetate Disperse the above coating liquid composition (solid content weight ratio CGM-1: KR-5240 = 2: 1) using a sand mill for 17 hours. The chemical formula of CGM-1 is shown in Chemical Formula 1.

  It was good with no coating unevenness.

  Although the above embodiment has been described with respect to drying of the photosensitive material-containing paint when manufacturing the photosensitive drum of the electrophotographic apparatus, the present invention is not limited to this and can be applied to other appropriate coating drying.

It is a front view which shows the whole structure of a continuous coating device. It is sectional drawing of the application | coating means of FIG. It is a perspective view of the application means of FIG. It is a structure sectional view of a simultaneous multilayer coating device. It is a structure sectional view of a sequential multilayer coating device. It is a longitudinal cross-sectional view of a positioning device and a vertical coating device. It is PP sectional drawing and QQ sectional drawing of the said coating device. It is a schematic cross section showing other various examples of a positioning device. 1 is an overall layout diagram of a coating and drying apparatus. It is a partially cut perspective view of a coater. It is sectional drawing showing the state at the time of application | coating of a cylindrical base material and a coater. It is sectional drawing of a drying apparatus. It is a partially broken perspective view of the suction member provided with the suction slit. It is a partially broken perspective view of a suction member provided with a punch plate. It is a partially broken perspective view of the suction member provided with the mesh.

Explanation of symbols

1,1a, 1b Cylindrical base material (photosensitive drum)
DESCRIPTION OF SYMBOLS 11 Coating liquid 12A Coating liquid outlet 13A Coating liquid distribution slit 14A Coating liquid distribution chamber 12B Suction chamber 13B Buffer space 14B Air flow 15B Suction nozzle 16B Suction slit 18B Suction slit member (suction member)
2,2A Coating film 20 Positioning device (positioning means)
21A outer cylinder member 22A inner cylinder member (fluororesin)
23A Air supply port 25A Discharge port 26A Exhaust port 28A Tapered surface 30, 32 Application head (coater, application means)
4 hopper surface 4b, 42b annular end 6a, 6b, 6c coating liquid supply port 7 coating liquid distribution chamber 8 coating liquid distribution slit 9 outlet opening 9B, 10B cylindrical member 150 drying device GP gap G gap

Claims (4)

A cylindrical base material coated with a coating film on the outer peripheral surface is provided with a ring-shaped circumferentially uniform suction member concentrically on the outer periphery and inserted from an insertion opening of the cylindrical member, and the cylindrical shape is inserted when the cylindrical base material is inserted. In the method of drying a cylindrical base material that sucks a gap between the base material surface and the inner surface of the cylindrical member concentrically to generate an air flow, and promotes drying of the coating film,
When the total length of the cylindrical member is L ₀ and the distance from the insertion opening of the cylindrical base material of the cylindrical member to the suction member is L ₁ ,
0.5 <L ₁ / L ₀ <1.0
A method for drying a cylindrical substrate characterized by satisfying the following conditions: Furthermore, when the total length of the cylindrical member is L ₀ and the distance from the insertion opening of the cylindrical base material of the cylindrical member to the suction member is L ₁ ,
0.6 <L ₁ / L ₀ <0.9
The method for drying a cylindrical substrate according to claim 1, wherein the following condition is satisfied. The cylindrical base material coated with the coating film is provided with a ring-shaped circumferentially uniform and concentric suction member on the outer periphery of the cylindrical member that can be inserted from the insertion opening, and the cylindrical base material is connected to the insertion opening. In the cylindrical substrate drying apparatus that sucks the gap between the cylindrical substrate surface and the inner surface of the cylindrical member concentric at the time of insertion to generate an air flow, and accelerates drying of the coating film,
When the total length of the cylindrical member is L ₀ and the distance from the insertion opening of the cylindrical member to the suction portion of the suction member is L ₁ ,
0.5 <L ₁ / L ₀ <1.0
A cylindrical substrate drying apparatus characterized by satisfying the following conditions: Furthermore, when the total length of the cylindrical member is L ₀ and the distance from the insertion opening of the cylindrical member to the suction portion of the suction member is L ₁ ,
0.6 <L ₁ / L ₀ <0.9
The cylindrical substrate drying apparatus according to claim 3, wherein the following condition is satisfied.

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