JP4802051B2 - Method for forming elastic roller - Google Patents

Description

  In the present invention, when forming an elastic roller formed by directly forming a resin surface layer around a core metal, one end portion of the core metal is masked, and the core metal is used for the resin surface layer with this one end portion facing down. With respect to the elastic roller forming method for forming the resin surface layer by dipping in a dip solution and then curing it, in particular, it is possible to obtain a uniform thickness up to the end even for the resin surface layer of a thin film About things.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, various elastic rollers are used for the purpose of imparting electric charge to the surface of a latent image carrier such as a photosensitive drum or supplying a developer. ing. As these elastic rollers, as shown in a cross-sectional view in FIG. 1, a structure in which an elastic layer 92 is arranged around a cored bar 91 and a thin resin surface layer 93 is formed outside thereof is widely used. After forming the resin surface layer 93 of the elastic roller 90 having such a structure and forming the elastic layer 92 on the outside of the cored bar 91, as shown in FIG. 2, the end of the elastic layer 92 of the cored bar 91 is shown. A cap 95 made of resin or the like is put on the one end 91a that protrudes outward in the lengthwise direction from this, and this portion is masked. Next, as shown in FIG. A method is known in which the whole is immersed in a dip solution 96 for the resin surface layer and then pulled up to apply the resin surface layer dip solution to the surface of the elastic layer 92, then the solution is dried and cured, and finally the cap 95 is removed. Cage (for example, patent Document 1 reference.) According to this method, by matching the thickness of the cap 95 to that of the elastic layer, it is possible to form a resin surface layer 93 having a uniform thickness up to the end.

On the other hand, as a recent trend, it is required to reduce the diameter of the elastic roller for the purpose of reducing the size and weight of the apparatus. As an elastic roller for that purpose, a thin resin surface layer directly on the outside of the core metal 91 is required. An elastic roller having a structure for forming 93 is proposed. As a method of forming such an elastic roller, as an extension of the prior art, there is a method of forming a cored bar 91 covered with a cap 95 at one end and immersing it in a dip liquid 96 for a resin surface layer and pulling it up. Conceivable.
JP 2000-343622 A

  However, when the resin surface layer is formed by the above-described conventional method, it is difficult to form the cap 95 thin, and the thickness of the cap 95 is increased, and as shown in a conceptual diagram in FIG. The resin surface layer dip solution 96 applied to the core 91 accumulates on the top of the cap 95 to increase the diameter, and after removing the cap 95, as shown in FIG. There is a problem in that a thick portion 93a is formed at the end of the film.

  The present invention has been made in view of such problems, and masks one end portion of the cored bar and immerses the cored bar in a dip solution for the resin surface layer with this one end side facing down. It is an object of the present invention to provide a method for forming an elastic roller capable of forming a resin surface layer having a uniform thickness up to the end when forming the surface layer.

<1> is a method in which a resin surface layer is directly disposed around a portion of the core bar excluding both shaft end portions to form an elastic roller by masking one shaft end portion of the core bar. In the method of forming an elastic roller for forming the resin surface layer, the core metal is dipped in a dip solution for the resin surface layer with the part facing down and pulled up to be cured.
In the paint containing an ultraviolet curable resin whose adhesive strength to the core metal is lower than that of the resin surface layer, the length of the shaft end portion is equal to the length of the shaft end portion. Pull up after dipping, then cure the paint adhering to this shaft end with ultraviolet rays to make the masking,
A method of forming an elastic roller that cures the dip solution for the resin surface layer, then cuts the resin surface layer at the boundary position of the shaft end, and pulls out the masking from the core to expose the shaft end of the core It is.

  <2> is a method for forming an elastic roller in <1>, wherein the resin surface layer has a thickness of 10 to 300 μm.

  <3> is a method for forming an elastic roller in which the maximum masking thickness is 5 to 300 μm in <1> or <2>.

  According to <1>, the shaft end of the core bar is placed in a paint containing an ultraviolet curable resin whose adhesiveness to the core bar is lower than that of the resin surface layer, with the one shaft end portion facing down. After being immersed for the length of the part, it is pulled up, and then the masking is performed by curing the paint adhering to this shaft end part with ultraviolet rays, so that the masking thickness can be made extremely thin. , By suppressing the accumulation of liquid in the vicinity of the masking boundary position of the resin surface layer, the thickness can be made uniform up to the edge, and by performing masking with ultraviolet rays, curing can be shortened In addition, it is possible to increase the productivity, suppress the flow of the paint until curing, suppress the variation of the masking boundary position, and contribute to the uniformity of the end position of the resin surface layer.

  Further, according to <1>, after the dip liquid for the resin surface layer is cured, the resin surface layer is cut at a boundary position of the shaft end portion, and the masking is pulled out from the core metal to thereby remove the shaft end of the core metal. Since the portion is exposed, the productivity in the masking removal process can be increased.

  According to <2>, since the thickness of the resin surface layer is set to 300 μm or less, the effect of <1> can be further emphasized. If the thickness is less than 10 μm, the thickness tends to be non-uniform, and the performance of the elastic roller will vary, which is not preferable.

  According to <3>, when the resin surface layer having the above thickness is formed, when the masking thickness exceeds 300 μm, in the vicinity of the masking boundary when the resin surface layer is formed. It may be difficult to suppress the swell of the paint, and if the masking thickness is less than 5 μm, the masking thickness is likely to vary, and an unmasked part may occur. Absent.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing an elastic roller formed by the elastic roller forming method according to the embodiment of the present invention. The elastic roller 10 includes a core metal 1 and a resin surface directly formed on the outer peripheral surface thereof. The portions of the core bar 1 that are exposed by projecting to the outside in the length direction of the resin surface layer 3 constitute shaft end portions 1a and 1b that are attached to the apparatus of the elastic roller 10.

  6 to 11 are conceptual diagrams showing a method of forming the elastic roller 10 configured as described above. First, a cored bar 1 is prepared, and one shaft end 1a of the cored bar is masked. This is done as follows. That is, as shown in FIG. 6, the core metal 1 is placed in the paint 21 containing the ultraviolet curable resin contained in the tank 22 with the length 1 of the shaft end 1a with the shaft end 1a facing down. After dipping and pulling up the metal core 1 from the paint 21, as shown in FIG. 7, the paint 21 adhered to the shaft end 1a is irradiated with ultraviolet rays using an ultraviolet irradiation device 24 to form a masking 23. To do. Since the paint 21 contains an ultraviolet curable resin, it can be cured in a very short time by this irradiation.

  The ultraviolet curable resin used as the masking 23 is required to have a lower adhesive force to the cored bar 1 than the paint constituting the resin surface layer 3 as a selection requirement. When withdrawing from the gold 1, it is possible to remove only the masking 23 while leaving the resin surface layer 3.

  Next, as shown in FIG. 8, the cored bar 1 on which the masking 23 has been applied has a predetermined length in the dip liquid 31 for the resin surface layer accommodated in the dip tank 32 with the shaft end 1 a facing down. Then, after the core metal 1 is pulled up from the dipping solution 31, the resin surface layer 3 is directly formed on the outside of the core metal 1 by drying and curing it with a heater 34 or the like as illustrated in FIG. 9.

  Finally, the masking 23 is removed to expose the shaft end 1a of the metal core 1. As shown in FIG. 10, the resin surface layer 3 is removed by a cutter or the like at the boundary position F of the shaft end 1a. This can be realized by cutting and then withdrawing the masking 23 from the cored bar 1. That is, since the adhesive force of the ultraviolet curable resin constituting the masking 23 to the core metal 1 is lower than that of the resin surface layer 3, by pulling out the masking 23 from the core metal 1, as shown in FIG. Only the masking 23 can be removed while leaving the resin surface layer 3. At this time, the portion formed on the masking 23 of the resin surface layer 3 is separated from the portion directly applied to the core metal 1 by the previous cutting. Therefore, it can be removed together with the masking 23.

  Thus, since the masking 23 is formed by curing a paint containing an ultraviolet curable resin, the film thickness of the masking 23 can be made extremely thin, and thus the boundary of the masking 23 of the resin surface layer 3 can be obtained. The liquid puddle in the portion can be suppressed and the resin surface layer 3 having a uniform thickness up to the end can be formed. Further, since the masking 23 is composed of an ultraviolet curable resin paint, it can be cured in a short time before the paint flows, which improves productivity in curing and variation in the boundary position of the masking 23. By making the value extremely small, it is also possible to suppress variations in the end position of the resin surface layer 3.

  The method according to the present invention can be effectively applied when the thickness of the resin surface layer 3 is 10 to 300 μm, more preferably 10 to 180 μm. The thickness is preferably 5 to 300 μm, more preferably 5 to 180 μm.

An example of a method for adjusting the paint dissolved in the dip liquid 31 for the resin surface layer will be described below.
(A) Example of polyurethane (solid type) Water-dispersed urethane resin (IZELUX S-4040N: manufactured by Hodogaya Chemical Co., Ltd.): 100 parts by mass, carbon black (MA100: manufactured by Mitsubishi Chemical Corporation): 10 parts by mass , And thickener (SN thickener A-815: manufactured by San Nopco Co., Ltd.): 1 part by mass is mixed with a stirring blade to prepare a coating material.

(B) Example of polyurethane (foam type) Water-dispersed urethane resin (IZELUX S-4040N: manufactured by Hodogaya Chemical Co., Ltd.): 100 parts by mass, carbon black (MA100: manufactured by Mitsubishi Chemical Corporation): 10 parts by mass And 3 parts by mass of a foam stabilizer (FR14: manufactured by Kao Corporation) are mixed with a high-speed foaming stirrer to prepare a foam paint having a foam density of 0.4 g / cm ³ .

(C) Example of rubber (solid type) Rubber latex (JSR0561: manufactured by JSR Corporation): 100 parts by mass, carbon black (MA100: manufactured by Mitsubishi Chemical Corporation): 10 parts by mass, colloidal sulfur (colloidal sulfur: Hosoi) Chemical Industry Co., Ltd.): 2 parts by mass, and thickener (SN thickener A-815: San Nopco Co., Ltd.): 1 part by mass are mixed with a stirring blade.

(D) Example of rubber (foam type) Rubber latex (JSR0561: manufactured by JSR Corporation): 100 parts by mass, carbon black (MA100: manufactured by Mitsubishi Chemical Corporation): 10 parts by mass, colloidal sulfur (colloidal sulfur: Hosoi) Chemical Industry Co., Ltd.): 2 parts by mass and foaming agent (FR25: Kao Co., Ltd.): 0.5 parts by mass were mixed with a high-speed foaming stirrer, and the foam density was 0.4 g / cm ³ . Adjust foam paint.

  Moreover, as a coating material used for the masking 23, the following preparation examples can be shown. That is, oligomer (trade name: UF8001 (manufactured by Kyoeisha Chemical Co., Ltd.), structure: urethane acrylate oligomer): 60 parts by mass, monomer (trade name: NK ester A-TMPT-3EO (manufactured by Shin-Nakamura Chemical Co., Ltd.) ), Structure: ethoxylated trimethylolpropane triacrylate): 40 parts by mass, photoinitiator (trade name: IRGACURE184D (manufactured by Ciba Specialty Chemicals Co., Ltd.), structure: 1-hydroxy-cyclohexyl ruphenyl ketone): 1 The material blended in parts by mass is stirred at a temperature of 60 ° C. for 30 minutes to prepare a paint.

It is sectional drawing which shows the conventional elastic roller. It is a conceptual diagram which shows the method of forming the conventional elastic roller. FIG. 3 is a conceptual diagram illustrating a process following FIG. 2. It is sectional drawing which shows the elastic roller of the other conventional form. It is sectional drawing which shows the elastic roller formed by the formation method of the elastic roller of embodiment which concerns on this invention. It is a conceptual diagram explaining the process of the elastic roller of embodiment which concerns on this invention. FIG. 7 is a conceptual diagram illustrating a process following FIG. 6. FIG. 8 is a conceptual diagram illustrating a process following FIG. 7. FIG. 9 is a conceptual diagram illustrating a process following FIG. 8. FIG. 10 is a conceptual diagram illustrating a process following FIG. 9. It is a conceptual diagram which shows the process of following FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core metal 1a, 1b Shaft end of core metal 3 Resin surface layer 10 Elastic roller 21 Paint containing ultraviolet curable resin 22 Tank 23 Masking 24 Ultraviolet irradiation device 31 Dip liquid for resin surface layer 32 Dip tank 34 Heater F Boundary position of shaft end

Claims (3)

When forming the elastic roller by placing the resin surface layer directly around the portion of the core bar excluding both shaft ends, mask the one shaft end of the core and place this shaft end down. In the method for forming an elastic roller for forming the resin surface layer, the core metal is dipped in a dip solution for the resin surface layer and then pulled up to be cured.
In the paint containing an ultraviolet curable resin whose adhesive strength to the core metal is lower than that of the resin surface layer, the length of the shaft end portion is equal to the length of the shaft end portion. Pull up after dipping, then cure the paint adhering to this shaft end with ultraviolet rays to make the masking,
A method of forming an elastic roller that cures the dip solution for the resin surface layer, then cuts the resin surface layer at the boundary position of the shaft end, and pulls out the masking from the core to expose the shaft end of the core .   The method for forming an elastic roller according to claim 1, wherein the resin surface layer has a thickness of 10 to 300 μm. 3. The elastic roller forming method according to claim 1, wherein the maximum masking thickness is 5 to 300 [mu] m.

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