JP2005297249A - Mold for molding resin roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a resin roller which can easily automate the cleaning work of a mold for molding the resin roller and is high in productivity. <P>SOLUTION: A mold for molding the resin roller uses a cylindrical mold subjected to surface treatment to improve the mold releasing properties of a molding, a core body holding member which is arranged at the upper end of the cylindrical mold and has a space for storing a resin overflowing during injection, and an attachable/detachable valve body having a part for storing the overflowing resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin roller such as a developing roller, a charging roller, or a transfer roller incorporated in various apparatuses employing an electrophotographic system such as a laser printer, a copying machine, and a facsimile machine.

  Various apparatuses employing an electrophotographic system such as a laser printer, a copying machine, and a facsimile apparatus incorporate rollers such as a developing roller, a charging roller, and a transfer roller. A method for using the roller will be described below with reference to FIG. In various electrophotographic apparatuses, a nonmagnetic one-component developer 55 is supplied onto an image carrier 51 such as a photoreceptor 50 that holds an electrostatic latent image, and the electrostatic latent image on the surface of the image carrier 51 is applied to the electrostatic latent image. As a developing method for attaching a developer and visualizing an electrostatic latent image, a method of bringing the developing resin roller 10 into contact with the image carrier 51 is known. A typical shape of the resin roller is shown in FIGS. The resin roller 10 includes a core body 11, a cylindrical rubber elastic body layer 12 formed around the core body 11, and a surface layer 13 covering the rubber elastic body layer 12. The resin roller 10 conveys the non-magnetic one-component developer by an electric suction force between the regulating blade 52 for regulating the developer deposition thickness on the developing roller surface and the developer surface. In order to triboelectrically charge the developer, a resin roller 10 in which a rubber elastic body layer 12 is coated on a core body 11 is used. The rubber elastic layer 12 may be exposed on the surface as it is, but a thin surface layer 13 is often provided on the surface for the purpose of controlling the charging and transportability of the developer. Next, a method for manufacturing the resin roller 10 will be described. First, a mold 20 for molding the rubber elastic body layer 12 of the resin roller 10 is, for example, a cylindrical mold 22 and positions at both ends of the cylindrical mold 22 as shown in FIG. And it has the core body holding members 21 and 26 which hold | maintain the core body 11 inserted in the said cylindrical metal mold | die 22, and seal the both ends of the cylindrical metal mold | die 22. FIG. As shown in FIG. 2, a 0-ring 16 is mounted in an o-ring groove provided in the core body 11. Both ends of the core body are inserted into the core body holding members 21 and 26. The o-ring 16 attached to the core body closes the gap between the core body 11 and the core body insertion holes provided in the core body holding members 21 and 26. The cylindrical mold 22 and the core body holding members 21 and 26 are fastened by a ferrule clamp 38. One core holding member 21 is provided with a resin injection port 23 for injecting a thermosetting liquid resin into a roller molding space 25 formed in the cylindrical mold 22. Following the resin injection port 23, a slide-movable valve body 35 is provided to seal the liquid resin injected into the roller molding space 25 after completion of resin injection. The resin injection nozzle 40 of the molding machine is pressed against the hemispherical nozzle touch part 45, and the liquid resin is injected into the roller molding space 25. Then, after the injection of the liquid resin into the roller molding space 25 is completed, the valve body 35 is slid and closed, and the injection nozzle 40 shown in FIG. Thereafter, the liquid resin in the roller forming space 25 is heated and cured by heating in a heating furnace. After the curing of the resin is completed, the ferrule clamp 38 is removed, and the core body holding members 21 and 26 are removed from the cylindrical mold 22 along the axial direction thereof. Next, the core body 11 is pushed out against the cylindrical mold 22 and the molded body held in the cylindrical mold 22 is taken out. After releasing the roller body from the mold, the coating liquid prepared with a resin material is applied to the peripheral surface of the rubber elastic layer of the roller body obtained by the above molding method by a spray method, a dipping method, a roll coater method, etc. The surface layer 13 is formed by applying and drying. The mold 20 used for molding the resin roller is used for molding the resin roller again after removing the overflow resin adhering thereto.

  In the above molding method, it is difficult to automate the cleaning operation of the mold used for molding, and the productivity cannot be increased. (1) Contamination of the inner surface of the cylindrical mold due to the resin residue remaining in the cylindrical mold 22 after the resin roller is extracted after molding, (2) When the liquid resin is injected into the roller molding space 25 In order to expel the air in the mold, the mold 39 is contaminated by the resin 39 overflowed from the resin discharge section 24, and (3) the mold is contaminated by the resin overflowed by the nozzle touch section 45 provided in the mold 20. Occur. In order to reuse the mold 20 used for molding, it is difficult to automate the process because it is necessary to clean and confirm the mold contaminated with an irregular shape.

  The means for solving the above problem is shown in FIG. A mold 20 for molding the rubber elastic body layer 12 of the resin roller 10 is a cylindrical mold 22 and a core positioned at both ends of the cylindrical mold 22 and inserted into the cylindrical mold 22. It has core body holding members 21 and 26 for holding the body 11 and sealing both ends of the cylindrical mold 22. As shown in FIG. 2, a 0-ring 16 is mounted in an o-ring groove provided in the core body 11. In assembling the mold, first, the core body holding member 21 is fixed at a fixed position with the core body insertion hole facing upward, and the end portion of the core body 11 is inserted. Next, the cylindrical mold 22 is inserted. Finally, the core body holding member 26 is inserted into the core body 11. The o-ring 16 attached to the core body closes the gap between the core body 11 and the core body insertion holes provided in the core body holding members 21 and 26. The assembled mold 20 is attached to the spring-type mold holding frame shown in FIG. One core body holding member 21 is provided with one resin injection port 23 for injecting a liquid resin into a roller molding space 25 formed in the cylindrical mold 22. A rotary valve body 35 is provided to seal the liquid resin injected into the roller molding space 25 after the resin injection is completed following the resin injection port 23. A resin injection nozzle 40 of the molding machine is pressed against a hemispherical nozzle touch part 45 provided on the rotary valve body 35, and a thermosetting liquid resin is injected into the roller molding space 25. The air in the roller molding space 25 passes through the resin discharge port 24 provided at one location on the other core body holding member 26 and is exhausted from the exhaust hole 29. Then, after the injection of the liquid resin into the roller molding space 25 is completed, the injection nozzle is pulled apart to rotate the valve body 35 to be closed, and the liquid resin injected into the molding space 25 is sealed. Thereafter, the mold 20 is heated in a heating furnace while being held on the mold holding frame, and the liquid resin in the roller molding space 25 is heated and cured. After the curing of the resin is completed, the mold 20 is removed from the mold holding frame, and the core body holding members 21 and 26 are removed from the cylindrical mold 22 along the axial direction thereof. Next, the core body 11 is pushed out with respect to the cylindrical mold 22, and the molded body held in the cylindrical mold 22 is taken out. The molded body taken out is cut and removed at the protruding portion at the end, and then the surface layer 13 is applied around the rubber elastic body layer. The cylindrical mold 22, the core body holding members 21 and 26, and the valve body 35 used for molding are assembled again and used for molding after being cleaned by a washing machine. In this way, the resin roller is automatically formed. According to the present invention, (1) since the inner surface of the tube mold is subjected to Teflon (R) eutectoid electroless nickel plating, there is little generation of resin residue at the time of mold release, and it does not stick to the inner surface of the tube mold. Can be washed away. (2) When the liquid resin is injected into the roller molding space 25, the resin 39 overflowed from the resin discharge portion 24 in order to expel the air in the mold is stored in the overflow resin reservoir portion 37 provided in the core body holding member 26. It can be easily and automatically removed because it is hardened into a regular lump. (3) The liquid resin overflowing at the nozzle touch part 45 is entangled with the overflow resin reservoir part 37 provided on the rotary valve body 35 shown in FIG. I can clean it.

  According to the present invention, it is possible to easily automate the cleaning operation of the mold used for molding, and to increase the productivity of the resin roller. The effects are listed below. (1) Since the inner surface of the cylindrical mold is subjected to Teflon (R) eutectoid electroless nickel plating, the resin residue does not stick to the mold during mold release and can be easily cleaned. (2) When the liquid resin is injected, the overflowing liquid resin is expelled to expel the air in the mold, and is stored in the overflow resin reservoir provided in the core body holding member and hardened, so it can be easily removed mechanically. Can do. (3) Since the resin overflowing at the nozzle touch part is entangled with the overflowing resin reservoir provided on the rotary valve body and hardened, cleaning is easy.

  Examples of the resin roller manufacturing method of the present invention will be described. The resin roller 10 can be manufactured using a mold 20 shown in FIG. As shown in FIG. 3, the mold 20 is assembled in a mold holding frame and clamped by a holding frame spring 32. The core body 11 is disposed in the mold 20. A thermosetting liquid resin is injected into the roller molding space 25 from the resin injection nozzle 40 of the molding machine disposed below the mold 20 through the resin injection port 23. Then, after the resin filling in the roller molding space 25 is completed, the valve body 35 is rotated 90 degrees and closed, and the entire mold 20 is heated in a heating furnace while holding the mold 20 in the frame. The liquid resin filled in is heated and cured. After the resin is cured, the mold 20 is taken out of the holding frame, and the core body holding members 21 and 26 are extracted from the cylindrical mold 22 along the axial direction thereof. Next, the core body 11 is pushed out with respect to the cylindrical mold 22, and the molded body held in the cylindrical mold 22 is taken out. A cylindrical rubber elastic body layer 12 is formed around the core body 11. The molded body taken out is cut and removed at the protruding portion at the end, and then the surface layer 13 is applied around the rubber elastic body layer. As a resin material that can be used in the molding method of the present invention, a known thermosetting liquid resin is used. For example, polyurethane, ethylene / propylene / diene / methylene copolymer (EPDM), silicone and the like can be used, but the rubber elastic body layer has (A) at least one alkenyl group capable of hydrosilylation reaction in the molecule. Curing a curable composition containing, as essential components, an oxypropylene polymer, (B) a compound having at least two hydrosilyl groups in the molecule, (C) a hydrosilylation catalyst, and (D) a conductivity-imparting agent. It is preferable to obtain it. In the present invention, an alkenyl group capable of hydrosilylation reaction in the organic polymer of the component (A) is present at the terminal of the polymer, and the component (B) is at least on average in one molecule. It is preferable that it is a polyorganohydrogensiloxane containing two or more hydrosilyl groups, and the component (D) is carbon black. Here, the alkenyl group in the component (A) is not particularly limited as long as it is a group containing a carbon-carbon double bond that is active with respect to the hydrosilylation reaction. Cyclic unsaturated carbonization such as aliphatic unsaturated hydrocarbon groups such as allyl group, methylvinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, cyclopropenyl group, cyclobutenyl group, cyclopentenyl group, cyclohexenyl group, etc. A hydrogen group, a methacryl group, etc. are mentioned. The number of alkenyl groups in the oxypropylene-based polymer is at least one for the hydrosilylation reaction with the component (B) which is a curing agent. From the viewpoint of obtaining good rubber elasticity, In the case of a molecule having two alkenyl groups at both ends of the molecule, and in the case of a branched molecule, it is preferable to have two or more alkenyl groups at the molecule end. The component (A) in the present invention desirably has an alkenyl group capable of hydrosilylation reaction at the polymer end.

  The component (A) oxypropylene polymer refers to a polymer in which more than 50% of the repeating units constituting the main chain are composed of oxypropylene units. , A compound having two or more active hydrogens used as a starting material in the production of a polymer, such as units from ethylene glycol, propylene glycol, bisphenol compounds, glycerin, trimethylolpropane, pentaerythritol, ethylene oxide, butylene It may be a copolymerizable unit comprising an oxide or the like.

(B) component in this invention is used as a hardening | curing agent, and polyorganohydrogensiloxane is mentioned as one of the preferable things. The polyorganohydrogensiloxane mentioned here refers to a siloxane compound having a hydrocarbon group or a hydrogen atom on a silicon atom. There is no restriction | limiting in particular about the hydrosilylation catalyst which is (C) component of this invention, Arbitrary things can be used. Specifically, solid platinum is supported on a carrier such as chloroplatinic acid, platinum alone, alumina, silica, carbon black; platinum-vinylsiloxane complex {eg, Pt _n (ViMe ₂ SiOSiMe ₂ Vi) _n , Pt [(MeViSiO) ₄ ] _m }; platinum-phosphine complex {eg, Pt (PPh ₃ ) ₄ , Pt (PBu ₃ ) ₄ }; platinum-phosphite complex {eg, Pt [P (OPh) ₃ ] ₄ , Pt [P (OBu) ₃ ] ₄ } (wherein Me represents a methyl group, Bu represents a butyl group, Vi represents a vinyl group, Ph represents a phenyl group, and n and m represent an integer), Pt (acac) _2, also, platinum described in U.S. Patent 3,159,601 and in Pat 3159662 of Ashby et al - hydrocarbon complex, and Lamoreaux et al U.S. Pat. No. 3,220,972 Platinum Arcola described in Saisho - DOO catalysts may be mentioned. As the conductivity imparting agent of the component (D) of the present invention, carbon black, metal oxide, metal fine powder, quaternary ammonium salt, carboxylic acid group, sulfonic acid group, sulfuric acid ester group, phosphoric acid ester An organic compound or polymer having a group, an ether ester imide, an ether imide polymer, an ethylene oxide-epihalohydrin copolymer, a compound having a conductive unit represented by methoxypolyethylene glycol acrylate, or a polymer compound Examples thereof include compounds such as antistatic agents. (D) component in this invention may be used independently, and may use 2 or more types together. Examples of the carbon black include furnace black, acetylene black, lamp black, channel black, thermal black, and oil black. There are no restrictions on the type and particle size of these carbon blacks. The addition amount of (D) component is adjusted and added according to a desired electroconductive characteristic, 0.01-100 weight part with respect to 100 weight part of polymers of (A) component, Furthermore, 0.1-50 It is preferable to use parts by weight. Further, various fillers, antioxidants, ultraviolet absorbers, pigments and the like may be appropriately added to the thermosetting resin in the present invention. Moreover, you may add a softener and a plasticizer in order to adjust a viscosity and hardness. In the thermosetting resin of the present invention, a storage stability improving agent can be used for the purpose of improving storage stability. The storage stability improver is a normal stabilizer known as a storage stabilizer for the component (B) of the present invention, and may be any one that can achieve the intended purpose, and is particularly limited. is not. Specifically, a compound containing an aliphatic unsaturated bond, an organic phosphorus compound, an organic sulfur compound, a nitrogen-containing compound, a tin compound, an organic peroxide, or the like can be preferably used. More specifically, 2-benzothiazolyl sulfide, benzothiazole, thiazole, dimethylacetylene dicarboxylate, diethylacetylene dicarboxylate, butylhydroxytoluene, butylhydroxyanisole, vitamin E, 2- (4-morphodinyl) Dithio) benzothiazole, 3-methyl-1-buten-3-ol, acetylenically unsaturated group-containing organosiloxane, ethylenically unsaturated group-containing organosiloxane, acetylene alcohol, 3-methyl-1-butyl-3-ol, Examples include, but are not limited to, diallyl fumarate, diallyl maleate, diethyl fumarate, diethyl maleate, dimethyl maleate, 2-pentenenitrile, 2,3-dichloropropene, and the like. Various other additives can be added to the thermosetting resin. For example, a material that adjusts the thermosetting reaction, such as a curing agent, a curing accelerator, and a curing retarder, is added as necessary. Moreover, an organic or inorganic filler can be added as needed. Furthermore, various organic or inorganic pigments, thickeners, release agents and the like can be added as necessary. When the roller body obtained by the molding method is released from the mold 20, a protruding portion is formed at the end of the rubber elastic layer 12. Bubbles and chips resulting from the air remaining in the roller molding space 25 without being discharged are present in the end protrusions. The resin roller 10 is manufactured by applying the surface layer 13 around the rubber elastic body layer 12 of the roller main body after cutting and removing the end protrusions containing the defects. The material for forming the surface layer 13 is not particularly limited, but it contains a urethane bond from the viewpoint of conductive properties and abrasion resistance, and from the viewpoint of flexibility, a resin having a polyether, polyester, or polycarbonate skeleton. It may be composed of a urethane resin composition as a main composition, and is a blend resin of urethane resin and polyether, polyester and polycarbonate, a group consisting of urethane bond and polyether, polyester, polycarbonate and polysiloxane in one molecule. It may be a urethane resin composition containing at least one skeleton selected in.

  In addition, various additives such as conductivity imparting agents and various fillers are added to the resin composition constituting the surface layer as necessary from the viewpoints of resistance adjustment, surface shape adjustment, adhesion to the conductive elastic layer, etc. May be. Although there is no restriction | limiting in particular as a formation method of a surface layer, Using methods, such as spray coating, dip coating, and roll coating, the resin composition which comprises a surface layer from the rubber elastic body layer surface-treated with the primer. A surface layer can be formed by applying to a predetermined thickness, drying and curing at a predetermined temperature. Specifically, a method in which the resin used as the surface layer is dissolved in a solvent so that the solid content is 5 to 20% and spraying or dipping is simple. The solvent to be used is not particularly limited as long as the resin as the main component of the surface layer to be used is compatible. Specifically, methyl ethyl ketone, butyl acetate, ethyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide And toluene.

  Examples of the present invention will be described below.

(Example 1)
As thermosetting liquid resin material, (A) allyl group-terminated oxypropylene polymer shown in Table 1 below is blended with (B) polysiloxane curing agent, (C) platinum complex catalyst, and (D) carbon black. The raw material was used. Using a mold 20 shown in FIG. 3, a roller body having a core body outer diameter of 8 mm, a rubber elastic body layer 12 of 16 mm, and a length of 250 mm was molded using a liquid resin injection molding machine. Since the mold is held on the spring-type frame, the mold is assembled simply by lifting the holding frame intermediate plate 28 and inserting the mold 20 incorporating the core body 11 as a single unit and lifting the holding frame middle. When the board 28 is lowered, the process is completed. The viscosity of the blended liquid resin was 600 poise, and the injection pressure at the time of injection was 1 MPa. The diameter of the resin injection port 23 provided in the core body holding member 21 of the mold 20 was 1.5 mm. The core body 11 is assembled in advance, the mold 20 is attached to the holding frame, the longitudinal direction of the cylindrical mold 22 is set up vertically, and the hemispherical shape provided in the valve body 35 incorporated in the lower part of the core body holding member 21. A liquid resin was injected into the nozzle touch portion 45 by bringing the injection nozzle 40 into contact pressure with an air cylinder from below. Immediately after the injection was completed, the nozzle was pulled apart and the valve body 35 was rotated 90 degrees to seal the liquid resin injected into the roller molding space 25. Next, the mold was held on a frame and hung on a conveyor, placed in a heating furnace adjusted to 140 ° C., and heated for 15 minutes and then removed from the heating furnace. Next, the mold 20 is taken out from the mold holding frame, the core body holding members 21 and 26 are removed, and the mold is disassembled. Thereafter, the cylindrical mold was immersed in a water bath for 1 minute to cool, and then the cylindrical mold 22 was held and the core body 11 was pushed down to release the mold, thereby obtaining a molded body. After cutting off and removing the protruding portion at the end, a primer was applied, and a solution was prepared by diluting the formulation shown in Table 2 below with DMF (N, N-dimethylformamide) to 10%. The resin was sprayed around the rubber elastic layer of the roller body and dried to form a surface layer. All the above roller forming processes are automated. (1) Teflon (R) eutectoid electroless nickel plating containing 30 vol% or more of Teflon (R) (PTFE) was applied to the inner surface of the cylindrical mold. The thickness of the plating layer was 10 μm. Compared to the case where electroless nickel plating is applied, the frictional resistance at the time of mold release is reduced to 1/2 or less, resin residue due to friction at the time of mold release is less, and there is no sticking. Was easily washed with water. (2) The amount of liquid resin to be injected is 42 cc with respect to the inner volume of the mold 37.5 cc to expel the air in the mold, and 4.5 cc is the overflow resin reservoir 37 provided in the core body holding member 26. Overflowed. The air in the mold passed through the resin discharge port 24 provided in the core holding member 26 and was discharged from an exhaust hole 29 having a diameter of 2 mm provided in one place on the holding frame intermediate plate 28. The overflowed resin was cured by heating and formed into a regular lump, which could be removed mechanically. Since the capacity of the overflow resin reservoir 37 is 6 cc, the space does not become full. (3) Since the resin overflowing at the nozzle touch part 45 is entangled with the ring-shaped overflow resin reservoir part 37 provided on the rotary valve body 35 and cured by heating, it can be mechanically removed with a high-pressure water washer. .

External view of resin roller Cross section of resin roller Mold sectional view in an embodiment of the present invention Sectional drawing of the valve body in embodiment of this invention Cross section of conventional mold Cross-sectional view of main parts of electrophotographic apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Resin roller 11 Core body 12 Rubber elastic body layer 13 Surface layer 16 o-ring 20 Mold 21 Core body holding member 22 Cylindrical mold 23 Resin inlet 24 Resin outlet 25 Roller forming space 26 Core body holding member 27 Holding frame Upper plate 28 Holding frame intermediate plate 29 Exhaust hole 30 Holding frame lower plate 31 Holding frame support 32 Holding frame spring 35 Valve element 36 Resin passage 37 Overflow resin reservoir 38 Ferrule clamp 39 Overflow resin 40 Resin injection nozzle 45 Nozzle touch section 50 Photoconductor 51 Image carrier 52 Regulating blade 55 Non-magnetic one-component developer

Claims (3)

  A mold for molding a resin roller, characterized in that Teflon eutectoid electroless nickel plating is applied to the inner surface of the cylindrical mold.   A mold for molding a resin roller, characterized by having a closed space in which liquid resin overflowing at the time of pouring is stored and cured by heating.   A mold for molding a resin roller, which has a portion for storing overflowing resin and a liquid resin injection nozzle contact pressure portion, and has a detachable valve body that can be rotated and closed after injection is completed.

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