Roller for oa

Abstract

To suppress adhesion failure on an interface between a base material layer and an elastomer layer, in a roller for OA comprising the base material layer containing pigments for absorbing ultraviolet light, and the elastomer layer containing ultraviolet light curable elastomer.SOLUTION: A roller 10 for OA comprises: a conductive shaft 12; a base material layer 14 formed on an outer peripheral surface of the shaft 12; a primer layer 16 formed on an outer peripheral surface of the base material layer 14; and an elastomer layer 18 formed on an outer peripheral surface of the primer layer 16. The base material layer 14 contains: a foamed resin; and a pigment that is dispersed in the foamed resin and absorbs ultraviolet rays. The primer layer 16 contains a non-UV curable elastomer. The elastomeric layer 18 contains an ultraviolet curable elastomer. The base material layer 14 may further contain an ion conductive agent A. The elastomer layer 18 may further contain an ion conductive agent B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an office automation roller, and more particularly to an office automation roller used in various office automation devices such as copying machines, facsimiles, and laser printers. [Background technology]

[0002] In general, image formation using electrophotography involves the following steps: (a) A charging roller is used to uniformly charge the surface of an organic photoconductor (OPC) drum, (b) A laser is irradiated onto the charged OPC drum, and the charge in the irradiated area is cancelled, creating an electrostatic latent image on the surface of the OPC drum. (c) Toner is electrostatically attached (developed) onto the surface of the OPC drum using a developing roller. (d) transferring the toner from the surface of the OPC drum to the surface of the paper using a transfer roller; (e) Fixing the toner onto the paper using a fixing roller This is done by:

[0003] As described above, electrophotographic image forming apparatuses use various rollers such as charging rollers, developing rollers, transfer rollers, and fixing rollers (hereinafter, these may be collectively referred to as "OA rollers"). Office automation rollers typically have a metal shaft and an elastic layer formed on the surface of the metal shaft. The elastic layer is typically made of low-hardness polymer elastic foam. Other layers with specific properties may be formed on the surface of the elastic layer. For example, if the roller surface is made of low-hardness polymer elastic foam, toner may adhere to the roller surface, causing toner filming (a phenomenon in which a thin layer of toner adheres to the surface of a photosensitive drum). In such cases, a solid layer may be formed on the surface of the elastic layer to reduce the coefficient of friction.

[0004] Various proposals have been made in the past regarding such OA rollers and manufacturing methods thereof. For example, Patent Document 1 states: (a) forming an elastic layer consisting of a foam layer and a skin layer on the surface of a metal shaft; (b) Applying an ultraviolet-curable resin composition to the surface of the skin layer to a thickness of 100 μm; (c) The coating is hardened by irradiating it with ultraviolet light to form a solid layer. A method for manufacturing a foam roller is disclosed.

[0005] The same document states: (A) When a solid layer is formed by applying a solvent-based or water-based paint and drying it with hot air, a long drying line is required and the quality of the solid layer is not stable; and (B) When a solid layer is formed using an ultraviolet-curable resin composition, a long drying line is not required and the quality is stable. is stated.

[0006] Patent Document 2 discloses a roller for an image forming apparatus obtained by forming a foamed resin layer on the outer peripheral surface of a shaft and then forming a net-like resin layer on the outer peripheral surface of the foamed resin layer. The document describes that when such a roller for an image forming apparatus is used as a cleaning roller, the ability to scrape off toner adhering to the area to be cleaned is improved.

[0007] Patent Document 3 states: (a) Applying an adhesive made of ultraviolet curing resin to the outer surface of the shaft; (b) inserting a shaft into a through-hole of a cylindrical elastic body made of a material that transmits ultraviolet rays; (c) Irradiate the outer surface of the elastic body with ultraviolet light to harden the adhesive. The roller obtained by the above is disclosed. The document states that the use of such a method simplifies the work required to bond the elastic body and the shaft.

[0008] Furthermore, Patent Document 4 states: (a) preparing a composition containing a urethane prepolymer having an allyl group, a vinyl ether group, or an acrylate group as a terminal functional group, a polythiol, and a conductive agent; (b) applying the composition to a surface of a metal shaft to a thickness of 1 mm; (c) Irradiating the surface of the coating with ultraviolet light to harden the coating, (d) Using a cylindrical grinder, the surface of the hardened coating is ground to form a 0.5 mm thick elastic layer on the surface of the metal shaft. The charging roller obtained by the above process is disclosed. The document describes that this method makes it possible to form an elastic layer without using any acrylic compounding raw materials.

[0009] Among office automation rollers, transfer rollers, developing rollers, charging rollers, and the like require electrical conductivity. When the elastic layer (base layer) formed on the surface of a metal shaft is made solely of foamed resin, electrical conductivity is insufficient, so a conductive agent is typically added to the elastic layer. Furthermore, when the outermost surface of the elastic layer is made of foamed resin, electrostatic force is insufficient in the pores, which can result in partial toner transfer failure and partial image loss (hollowing). For this reason, a surface layer (elastomer layer) that does not contain pores is formed on the outermost surface of the elastic layer (base layer) made of foamed resin.

[0010] When forming an elastomer layer on the surface of a substrate layer, if an ultraviolet-curable elastomer is used as the elastomer layer, the elastomer layer can be formed in a short time. However, if the conductive agent contained in the substrate layer is a pigment that absorbs ultraviolet light, such as carbon, using an ultraviolet-curable elastomer as the elastomer layer can cause poor curing at the interface between the substrate layer and the elastomer layer, making it difficult to ensure sufficient adhesive strength. On the other hand, if a non-ultraviolet curable elastomer such as a thermosetting elastomer or a moisture curable elastomer is used as the elastomer layer in order to solve this problem, there is a problem that it takes a long time to cure. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-310136 [Patent Document 2] Japanese Patent Application Publication No. 2018-077268 [Patent Document 3] Japanese Patent Publication No. 2021-025639 [Patent Document 4] Patent No. 6847599 Summary of the Invention [Problem to be solved by the invention]

[0012] The problem that the present invention aims to solve is to suppress poor adhesion at the interface between a base layer containing a pigment that absorbs ultraviolet light and an elastomer layer containing an ultraviolet-curable elastomer in an OA roller that has such a base layer and an elastomer layer. [Means for solving the problem]

[0013] In order to solve the above problems, the OA roller according to the present invention comprises: a conductive shaft; a base material layer formed on an outer circumferential surface of the shaft; a primer layer formed on the outer peripheral surface of the substrate layer; an elastomer layer formed on the outer peripheral surface of the primer layer; Equipped with the base layer includes a foamed resin and a pigment that absorbs ultraviolet light and is dispersed in the foamed resin; the primer layer contains a non-ultraviolet curable elastomer, The elastomer layer includes an ultraviolet curable elastomer. [Effects of the Invention]

[0014] When a raw material for an ultraviolet-curable elastomer is applied directly to the outer surface of a substrate layer containing a pigment that absorbs ultraviolet light and a foamed resin, and the coating is then irradiated with ultraviolet light, poor curing of the raw material occurs near the interface between the substrate layer and the elastomer layer. This is thought to be because the pigment absorbs or blocks ultraviolet light near the interface between the substrate layer and the elastomer layer, preventing a sufficient amount of ultraviolet light from irradiating the raw material near the interface.

[0015] In contrast, when an elastomer layer containing an ultraviolet-curable elastomer is formed on the outer peripheral surface of a substrate layer containing an ultraviolet-absorbing pigment and a foamed resin, interposing a primer layer between the substrate layer and the elastomer layer suppresses poor curing of the raw material of the ultraviolet-curable elastomer. This is thought to be because forming a primer layer on the outer peripheral surface of the substrate layer suppresses absorption or blocking of ultraviolet light by the pigment near the interface between the primer layer and the elastomer layer. Furthermore, the curing time can be shortened compared to when the entire elastomer layer and primer layer are made using non-UV-curable elastomers such as thermosetting elastomers or moisture-curing elastomers. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a front view (left) of an OA roller according to the present invention and a cross-sectional view (right) taken along line AA' thereof. [Figure 2] 1 is a schematic diagram illustrating a conventional method for manufacturing an OA roller. [Figure 3] 1A to 1C are schematic diagrams illustrating a method for manufacturing an OA roller according to the present invention.

[0017] An embodiment of the present invention will be described in detail below. [1. Office automation rollers] 1 shows a front view (left) of an OA roller according to the present invention and a cross-sectional view (right) taken along line A-A' thereof. In FIG. 1, the OA roller 10 is a conductive shaft 12; a base material layer 14 formed on the outer circumferential surface of the shaft 12; a primer layer 16 formed on the outer peripheral surface of the substrate layer 14; An elastomer layer 18 formed on the outer peripheral surface of the primer layer 16; It is equipped with: An OC layer (not shown) may further be formed on the surface of the elastomer layer 18.

[0018] [1.1. Shaft] The shaft 12 is made of a conductive material. There are no particular limitations on the material of the shaft 12, as long as it is conductive. Examples of the material of the shaft 12 include: (a) Metals such as stainless steel, aluminum alloys, copper alloys, and magnesium alloys; (b) A composite material in which a conductive agent is dispersed in a resin matrix. (c) Composite material with a conductive coating formed on the surface of resin etc. In particular, a metal shaft is preferable for the shaft 12. This is because metal shafts have higher conductivity and strength than shafts made of other materials, and are also less expensive.

[0019] The diameter and length of the shaft 12 are not particularly limited, and optimal values ​​can be selected depending on the purpose. The shaft 12 may be a solid shaft or a hollow shaft.

[0020] [1.2. Base material layer] A base layer 14 is formed on the outer peripheral surface of the shaft 12. In the present invention, the base layer 14 contains a foamed resin and a pigment that absorbs ultraviolet light dispersed in the foamed resin. The base layer 14 may consist of only a foamed resin and a pigment, or may further contain an ion conductive agent A in addition to these.

[0021] [1.2.1. Materials] [A. Foam resin] In the present invention, the type of foamed resin is not particularly limited. Examples of foamed resin materials include polyurethane, silicone rubber, ethylene-propylene-diene rubber (EPDM), acrylonitrile-butadiene rubber (NBR), natural rubber, styrene-butadiene rubber (SBR), butadiene rubber, isoprene rubber, polynorbornene rubber, butyl rubber, chloroprene rubber, acrylic rubber, epichlorohydrin rubber (ECO), and ethylene-vinyl acetate copolymer (EVA).

[0022] Among these, foamed polyurethane is preferred as the foamed resin. During use, the OA roller 10 repeatedly comes into contact with and separates from an object at high speed, repeatedly deforming and restoring accordingly. If the surface of the OA roller 10 has a weak restoring force, the OA roller 10 may come into contact with the next object while the surface is still in a concave state, resulting in horizontal white streaks and color unevenness in the image. Polyurethane foam has a greater restoring force than other materials, making it less likely to cause such white streaks and color unevenness. Another advantage of polyurethane foam is its excellent abrasion resistance.

[0023] In the present invention, the density of the foamed resin is not particularly limited, and an optimum value can be selected depending on the purpose. Generally, if the density is too low, when a liquid primer material is applied to the surface of the base layer 14, it may be difficult to retain the primer material on the surface of the base layer 14. Therefore, the density is set to 35 kg / m 3 The above is preferable. On the other hand, if the density is too high, it may be difficult to produce the foamed resin. Therefore, the density is set to 800 kg / m 3 The density is preferably 720 kg / m or less. 3 The following is the result. In the present invention, the "density of the base layer 14" refers to the density of the foamed resin containing the pigment and the ion conductive agent A that is added as needed.

[0024] The bubbles contained in the foamed resin are preferably closed bubbles, because when the primer layer 16 is formed on the surface of the base layer 14, the raw material of the primer layer 16 does not easily penetrate into the foamed resin. Furthermore, it is preferable that the surface of the base layer 14 has small irregularities. This is because the smaller the irregularities on the surface of the base layer 14, the easier it is to fill in recesses on the surface of the base layer 14 with the primer.

[0025] [B. Pigments] The substrate layer 14 includes a pigment dispersed within a foamed resin. "Pigments are dispersed within the foamed resin" means (a) The pigment is filled into the gaps between the polymer chains that make up the foamed resin, and / or (b) The pigment is filled into the bubbles of the foamed resin. This refers to...

[0026] The pigment is added mainly to color the base layer 14 to a desired color, to prevent discoloration (yellowing) of the foamed resin from being noticeable, and to control the electrical conductivity of the base layer 14. In the present invention, the pigment is made of a material that absorbs ultraviolet light. The pigment may be a material that has high electrical conductivity, or may not be a material that has high electrical conductivity. Examples of pigments include: (a) carbon, (b) Metal powders such as aluminum, copper, and nickel, (c) conductive metal oxide powders such as tin oxide, titanium oxide, and zinc oxide; etc. In particular, carbon is preferred as the pigment because the base layer 14 is colored black, making yellowing less noticeable, and the conductivity of the base layer 14 can be controlled relatively easily.

[0027] There are various types of carbon materials with different shapes and electrical conductivities. Examples of carbon include: (a) Carbon blacks with large structures, such as acetylene black and ketjen black, which have a large function of increasing the conductivity of the substrate layer 14 (hereinafter, these are also collectively referred to as "conductive carbon"); (b) carbon black with a small structure, such as furnace black, which has little function of increasing the conductivity of the base layer 14 (hereinafter, these are also collectively referred to as "pigment carbon"); (c) graphite powder, (d) Carbon fiber etc.

[0028] [C. Ionic Conductive Agent A] When the OA roller 10 is used as, for example, a transfer roller, the base layer 14, primer layer 16, and elastomer layer 18 must have a predetermined electrical conductivity. If the electrical conductivity required for the OA roller 10 can be obtained simply by adding a pigment to the base layer 14 and optimizing the primer layer 16 and elastomer layer 18 (including optimizing the thickness of each layer), the ionic conductive agent A is not necessarily required. On the other hand, if the electrical conductivity required for the OA roller 10 cannot be obtained simply by adding a pigment to the base layer 14 and optimizing the primer layer 16 and elastomer layer 18, it is preferable to add the ionic conductive agent A to the base layer 14.

[0029] In the present invention, the material of the ion conductive agent A added to the base material layer 14 is not particularly limited. Examples of the ion conductive agent A include: (a) Ammonium salts such as perchlorates, chlorates, hydrochlorides, bromates, iodates, hydrofluoric acid salts, sulfates, ethyl sulfates, carboxylates, and sulfonates, such as tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium (e.g., lauryltrimethylammonium), hexadecyltrimethylammonium, octadecyltrimethylammonium (e.g., stearyltrimethylammonium), benzyltrimethylammonium, and modified fatty acid dimethylethylammonium; (b) Perchlorates, chlorates, hydrochlorides, bromates, iodates, hydrofluoroborates, trifluoromethyl sulfates, sulfonates of alkali metals and alkaline earth metals, such as lithium, sodium, potassium, calcium, and magnesium; (c) The cation species has an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a piperidinium ion, or a phosphonium ion, Salts whose anion species include halogen ions such as chlorine, bromine, and iodine, boron ions such as tetrafluoroborate ions, phosphate ions such as hexafluorophosphate ions, and sulfate ions such as bis(trifluoromethanesulfonyl)imide ions. etc.

[0030] [1.2.2. Content] The content of the pigment contained in the base layer 14 is not particularly limited, and the optimal content can be selected depending on the type of pigment, the presence or absence of ion conductive agent A, the use of the OA roller 10, etc. Similarly, when the base layer 14 contains an ionic conductive agent A, the content of the ionic conductive agent A is not particularly limited, and the optimal content can be selected depending on the type of pigment, the use of the OA roller 10, etc.

[0031] Generally, if the pigment content is too low, yellowing becomes noticeable or the desired conductivity may not be achieved, so the pigment content is preferably 0.4 mass% or more. On the other hand, if the pigment content is excessive, the viscosity of the raw material containing the pigment increases excessively, which may make it difficult to manufacture the base layer 14. Furthermore, if the pigment content is excessive, the base layer 14 may become brittle. Therefore, the pigment content is preferably 19.6 mass% or less.

[0032] The content of the ion conductive agent A is not particularly limited, and an optimum content can be selected depending on the purpose. Generally, the higher the content of the ion conductive agent A, the higher the conductivity obtained. On the other hand, if the content of the ion conductive agent A is excessive, the mechanical properties of the base material layer 14 may be reduced. Specifically, the content of the ion conductive agent A is preferably 0.01 mass% or more and 10.0 mass% or less.

[0033] 1.2.3. Thickness There are no particular limitations on the thickness of the base layer 14, and an optimum thickness can be selected depending on the purpose. The thickness of the base layer 14 is usually about 1 mm to 10 mm.

[0034] [1.3. Primer layer] A primer layer 16 is formed on the outer peripheral surface of the base layer 14. The primer layer 16 is inserted between the base layer 14 and the elastomer layer 18 to prevent insufficient curing of the elastomer layer 18.

[0035] [1.3.1. Materials] In the present invention, the primer layer 16 contains a non-ultraviolet curable elastomer. The term "non-ultraviolet curable elastomer" refers to an elastomer that can be cured without being irradiated with ultraviolet light.

[0036] Examples of non-UV curable elastomers include: (a) Thermosetting and solvent-volatile elastomers such as polyurethane elastomers, acrylic elastomers, and styrene elastomers; (b) Undercoat paints such as acrylic, ethylene vinyl acetate, urethane, and epoxy paints etc. The material of the primer layer 16 is particularly preferably a polyurethane-based elastomer, because the glass transition temperature and temperature dependence of viscoelasticity of the polyurethane-based elastomer may be close to those of the materials used for the base layer 14 and the elastomer layer 18.

[0037] The material of the primer layer 16 may consist solely of a non-UV-curable elastomer, or may contain other components, as long as it can prevent contact between the material of the uncured elastomer layer 18 and the substrate layer 14. Examples of other components include materials that impart conductivity, such as metal powder or ionic conductive agents, but do not absorb UV light.

[0038] However, it is necessary that the primer layer 16 does not contain a pigment that absorbs ultraviolet light, because if the primer layer 16 contains a pigment that absorbs ultraviolet light, it becomes difficult to cure the raw material of the elastomer layer 18 with ultraviolet light. The primer layer 16 may be made of a foamed or non-foamed material. However, if the primer layer 16 is made of a foamed material, the raw material of the elastomer layer 18 may seep into the bubbles in the primer layer 16, and when the raw material of the elastomer layer 18 comes into contact with the base layer 14, the raw material may not be cured sufficiently. To prevent such seepage of the raw material, the primer layer 16 is preferably made of a non-foamed material.

[0039] 1.3.2 Thickness As described below, the primer layer 16 is formed by applying the raw material of the primer layer 16 to the surface of the base layer 14 and curing the coating. In this case, since the base layer 14 contains air bubbles, some of the raw material of the primer layer 16 may penetrate into the air bubbles of the base layer 14 and harden within the air bubbles. In the present invention, the "thickness of the primer layer 16" refers to the distance from the outermost surface of the base layer 14 to the outermost surface of the primer layer 16, and does not include the thickness of the region where the raw materials of the primer layer 16 have penetrated into the air bubbles in the base layer 14 and hardened.

[0040] The thickness of the primer layer 16 affects the performance and cost of the OA roller 10. If the primer layer 16 is too thin, poor curing may occur when the elastomer layer 18 is formed. Therefore, the thickness of the primer layer 16 is preferably greater than 0 mm. The thickness is more preferably 0.2 mm or greater. On the other hand, if the thickness of the primer layer 16 is too thick, it may take a long time to cure the primer layer 16, which may increase the manufacturing cost. Therefore, the thickness of the primer layer 16 is preferably 0.8 mm or less.

[0041] 1.4. Elastomer Layer An elastomer layer 18 is formed on the outer peripheral surface of the primer layer 16. The elastomer layer 18 is formed to suppress a lack of electrostatic force caused by unevenness of the base layer 14. In the present invention, the elastomer layer 18 contains an ultraviolet-curable elastomer. The elastomer layer 18 may consist solely of the ultraviolet-curable elastomer, or may further contain an ion conductive agent B in addition to the ultraviolet-curable elastomer.

[0042] [1.4.1. Materials] [A. UV-curable elastomer] The elastomer layer 18 includes an ultraviolet-curable elastomer. The ultraviolet-curable elastomer is not particularly limited as long as it can be cured using ultraviolet light. There are ultraviolet-curable elastomers that exhibit relatively high conductivity and those that exhibit relatively low conductivity. Either of these may be used as the material for the elastomer layer 18.

[0043] The elastomer layer 18 is, in particular, a raw material containing a urethane prepolymer having an allyl group, a vinyl ether group, or an acrylate group as a terminal functional group and a polythiol having a thiol group is applied to the surface of the primer layer; The coating film made of the raw materials is irradiated with ultraviolet light to cause an enethiol reaction. Preferably, the elastomer contains an elastomer obtained by In order to effectively carry out the reaction between the allyl group or the like and the thiol group, it is preferable to add a photopolymerization initiator to the raw materials. The elastomer layer 18 obtained by such a method has advantages over non-UV curable elastomers, such as lower curing equipment costs, the ability to downsize the curing equipment, and the ability to shorten the time required for curing.

[0044] Other materials for the elastomer layer 18 include, for example, a composition containing a (meth)acrylate oligomer and an ultraviolet polymerization initiator.

[0045] [B. Ion Conductive Material B] As described above, when the OA roller 10 is used as, for example, a transfer roller, the base layer 14, primer layer 16, and elastomer layer 18 must have a predetermined electrical conductivity. If the electrical conductivity required for the OA roller 10 can be obtained by only optimizing the material of the UV-curable elastomer that constitutes the elastomer layer 18 and optimizing the base layer 14 and primer layer 16 (including optimizing the thickness of each layer), the ionic conductive agent B is not necessarily required. On the other hand, if the electrical conductivity required for the OA roller 10 cannot be obtained by only optimizing the material of the UV-curable elastomer and optimizing the base layer 14 and primer layer 16, it is preferable to add the ionic conductive agent B to the elastomer layer 18.

[0046] In the present invention, there are no particular limitations on the material of the ion conductive agent B added to the elastomer layer 18. When the base layer 14 contains the ion conductive material A, the ion conductive material B may be the same material as the ion conductive material A, or may be a different material. Other aspects of the ion conductive material B are the same as those of the ion conductive material A, and therefore a description thereof will be omitted.

[0047] [1.4.2. Content] When the elastomer layer 18 contains the ionic conductive agent B, the content of the ionic conductive agent B is not particularly limited, and the optimal content can be selected depending on the type of ultraviolet-curable elastomer, the application of the OA roller 10, etc.

[0048] Generally, conductivity may decrease if the content of ion conductive agent B is too small. Therefore, the content of ion conductive agent B is preferably 0.05 mass% or more. On the other hand, an excessive content of the ionic conductive agent B may result in a decrease in the mechanical properties of the elastomer layer 18. Therefore, the content of the ionic conductive agent B is preferably 10.0 mass % or less.

[0049] Thickness The thickness of the elastomer layer 18 is not particularly limited, and an optimum thickness can be selected depending on the purpose. Generally, if the thickness of the elastomer layer 18 is too thin, the elastomer layer 18 may peel off when the surface of the elastomer layer 18 is polished after curing. Therefore, the thickness of the elastomer layer 18 is preferably 0.5 mm or more. On the other hand, even if the thickness of the elastomer layer 18 is made thicker than necessary, there is no difference in the effect and it is of no practical benefit. Therefore, the thickness of the elastomer layer 18 is preferably 5.0 mm or less. The thickness is more preferably 4.0 mm or less.

[0050] [1.5. OC layer] An OC layer (not shown) may be further formed on the surface of the elastomer layer 18. Here, the "OC layer" refers to a layer (surface coating layer) formed on the surface of the elastomer layer 18 for the purpose of imparting stain resistance to the OA roller 10. The material of the OC layer is not particularly limited, and an optimum material can be used depending on the purpose. For example, a water-based urethane paint can be used as the material of the OC layer. The thickness of the OC layer is not particularly limited, and an optimum thickness can be selected depending on the purpose. Specifically, the thickness of the OC layer is preferably 0.5 μm to 40 μm.

[0051] [1.6. Conductivity of OA rollers (volume resistivity)] "Volume resistivity" refers to the value calculated from the current value flowing between the shaft 12 and the outermost surface of the OA roller 10 when a current is passed between the shaft 12 and the outermost surface of the OA roller 10 under the conditions of temperature: 22°C±3°C, relative humidity: 55%±5%, and voltage: 100V. The volume resistivity of the OA roller 10 can be controlled by the composition and thickness of each layer.

[0052] The volume resistivity of the OA roller 10 is not particularly limited, and an optimum value can be selected depending on the purpose. Specifically, the volume resistivity of the OA roller 10 is preferably 3 (log Ω) or more and 10 (log Ω) or less.

[0053] [1.7. Usage] The OA roller 10 according to the present invention can be used for a variety of purposes, such as a transfer roller, a charging roller, a toner supply roller, a developing roller, a fixing roller, a paper feed roller, and a paper discharge roller.

[0054] [2. Manufacturing method for OA rollers] The OA roller 10 according to the present invention is (a) forming a base material layer 14 on the outer peripheral surface of the shaft 12; (b) forming a primer layer 16 on the outer peripheral surface of the substrate layer 14; (c) forming an elastomer layer 18 on the outer peripheral surface of the primer layer 16; (d) If necessary, an OC layer is further formed on the outer peripheral surface of the elastomer layer 18. It can be produced by

[0055] [2.1. 1st step] First, the base layer 14 is formed on the outer peripheral surface of the shaft 12 (first step). In the present invention, the method for forming the base layer 14 is not particularly limited. The base layer 14 can be formed, for example, by (a) A method of preparing a cylindrical foam containing a foaming resin, inserting a shaft into a through-hole of the foam, and bonding the foam and the shaft; (b) A method in which a shaft is erected in the center of a cylindrical mold, and foaming resin raw material is poured into the gap between the inner wall surface of the mold and the shaft, and the raw material is foamed and hardened inside the mold. etc.

[0056] Further, examples of methods for producing a foam containing a pigment and / or an ion conductive agent A include the following: (a) A method in which a pigment and / or an ion conductive agent A is added to a foaming resin raw material in advance, and the raw material is foamed and cured; (b) A method in which a foam is produced using a foaming resin raw material that does not contain a pigment and an ionic conductive agent A, the foam is immersed in a dispersion in which the pigment and / or the ionic conductive agent A is dispersed, the foam is pulled out of the dispersion, and then dried; etc.

[0057] The composition of the raw materials for producing the foamed resin is not particularly limited, and an optimum composition can be selected depending on the type of foamed resin. For example, when the foamed resin is made of polyurethane foam, it is preferable to use raw materials containing a predetermined ratio of polyol, isocyanate, foam stabilizer, resinification catalyst, pigment, and ionic conductive agent A. By mixing these raw materials in a mixer while blowing in an inert gas to cause mechanical foaming and curing, a foam made of polyurethane foam containing predetermined amounts of pigment and ionic conductive agent A can be produced.

[0058] Alternatively, a raw material may be used in which a polyol, an isocyanate, a foam stabilizer, a resinification catalyst, a blowing agent, a blowing catalyst, a pigment, and an ionic conductive agent A are blended in a predetermined ratio. When such a raw material is poured into a mold and heated to a predetermined temperature, foaming and curing occur, and a foam made of foamed polyurethane containing a predetermined amount of pigment and / or ionic conductive agent A can be produced.

[0059] [2.2. 2nd process] Next, a primer layer 16 is formed on the outer peripheral surface of the base layer 14. In the present invention, the method for forming the primer layer 16 is not particularly limited. The primer layer 16 can be formed, for example, by (a) A method in which a solvent-soluble elastomer is dissolved in a solvent such as water or an organic solvent, the solution is applied to the surface of the substrate layer 14, and the coating film is dried; (b) A method in which a low-viscosity liquid elastomer is applied to the surface of the base layer 14, and the coating is cured (addition curing, condensation curing) by heat, moisture, etc. etc.

[0060] [2.3. Third step] Next, the elastomer layer 18 is formed on the outer peripheral surface of the primer layer 16 . Specifically, the elastomer layer 18 is (a) A raw material of an ultraviolet-curable elastomer is applied to the surface of the primer layer 18; (b) Irradiate the coating with ultraviolet light to harden it. It can be produced by the above method.

[0061] The composition of the raw material for forming the elastomer layer 18 is not particularly limited, and it is preferable to select an optimum composition depending on the type of ultraviolet-curable elastomer. For example, when the elastomer layer 18 includes an elastomer obtained by photopolymerizing a urethane prepolymer and a polythiol, (a) a urethane prepolymer having an allyl group, a vinyl ether group, or an acrylate group as a terminal functional group; (b) a polythiol having a thiol group; (c) a photoinitiator, and (d) Ion Conductive Agent B It is preferable to mix them in a predetermined ratio. Such a raw material is applied to the surface of the primer layer 16, and the coating is irradiated with ultraviolet light to harden it, thereby forming the elastomer layer 18.

[0062] In this case, a urethane prepolymer having an allyl group, a vinyl ether group, or an acrylate group as a terminal functional group can be produced by adding a compound having an allyl group, a vinyl ether group, or an acrylate group to a urethane prepolymer synthesized from a polyol and an isocyanate. Examples of polythiols include esters of mercaptocarboxylic acids and polyhydric alcohols, fatty acid polythiols, and aromatic polythiols. Examples of the photopolymerization initiator include acetophenone-based compounds, benzophenone-based compounds, and thioxanthone-based compounds. When raw materials containing these are irradiated with ultraviolet light, the urethane prepolymer and polythiol undergo an enethiol reaction to form an elastomer. After curing, the surface of the elastomer layer is polished using a cylindrical polisher to adjust the shape.

[0063] [4. 4th step] Next, if necessary, an OC layer (surface coating layer) is formed on the surface of the elastomer layer 18. The method for forming the OC layer is not particularly limited, and an optimum method can be selected depending on the purpose.

[0064] [3. Effect] A schematic diagram of a conventional manufacturing method for an OA roller is shown in Figure 2. First, as shown in Figure 2(A), a base layer 14 is formed on the outer circumferential surface of a shaft 12. The base layer 14 is made of foamed resin 14a in which pigment 14b that absorbs ultraviolet light is dispersed. 2(B), a raw material 18a of an ultraviolet-curable elastomer is applied directly to the outer peripheral surface of the base layer 14. Since the base layer 14 contains the foamed resin 14a, part of the raw material 18a penetrates into the base layer 14.

[0065] When raw material 18a is irradiated with ultraviolet light in this state, raw material 18a on top of base material layer 14 is cured by the ultraviolet light to form elastomer layer 18, but raw material 18a does not cure properly near the interface between base material layer 14 and elastomer layer 18. This is thought to be because pigment 14b near the interface between base material layer 14 and elastomer layer 18 absorbs or blocks ultraviolet light, preventing a sufficient amount of ultraviolet light from irradiating raw material 18a near the interface.

[0066] Fig. 3 shows a schematic diagram of a manufacturing method for an OA roller according to the present invention. First, as shown in Fig. 3(A), a base layer 14 is formed on the outer circumferential surface of a shaft 12. The base layer 14 is made of foamed resin 14a in which pigment 14b that absorbs ultraviolet light is dispersed. 3(B), a primer layer raw material 16a is applied to the outer peripheral surface of the base layer 14. Because the base layer 14 contains a foamed resin 14b, part of the raw material 16a penetrates into the base layer 14. After the raw material 16a is applied, the solvent is evaporated or heat or moisture is applied, whereby the raw material 16a hardens and the primer layer 16 is formed.

[0067] 3(C), raw material 18a of ultraviolet-curable elastomer is applied to the outer peripheral surface of primer layer 16. If primer layer 16 is substantially bubble-free or if primer layer 16 is sufficiently thick, raw material 18a will not penetrate into primer layer 16 and substrate layer 14. When the raw material 18a is irradiated with ultraviolet light in this state, the raw material 18a is cured by the ultraviolet light and becomes the elastomer layer 18.

[0068] In the OA roller 10 according to the present invention, when an elastomer layer 18 containing a UV-curable elastomer is formed on the outer peripheral surface of a base layer 14 containing a UV-absorbing pigment 14b and a foamed resin 14a, a primer layer 16 is interposed between the base layer 14 and the elastomer layer 18. This prevents the UV-curable elastomer raw material 18a from curing poorly. This is believed to be because the formation of the primer layer 16 on the outer peripheral surface of the base layer 14 prevents the pigment 14b from absorbing or blocking UV light near the interface between the primer layer 16 and the elastomer layer 18. Furthermore, the curing time can be shortened compared to when the elastomer layer 18 and the primer layer 16 are entirely made of a non-UV-curable elastomer, such as a thermosetting elastomer or a moisture-curing elastomer. [Example]

[0069] (Examples 1 to 6, Comparative Examples 1 to 7) 1. Sample Preparation [1.1. Examples 1 to 6 and Comparative Examples 1 to 6] [1.1.1. Preparation of base layer] First, a foam (slab) was prepared to serve as the base layer. Next, the foam was cut into strips (each with a hole for inserting a shaft) the size of a single roll. A shaft with adhesive was inserted into the hole in the strip, and the shaft and strip were bonded together. Furthermore, the outer surface of the strip was polished using a cylindrical polishing machine to obtain a cylindrical base layer. Polyurethane foam was used for the foam to serve as the base layer. Details of the foam preparation method are as follows.

[0070] [A. ENDUR (mechanically foamed polyurethane foam)] Polyol, isocyanate, foam stabilizer, and resinification catalyst were mixed in a predetermined ratio. If necessary, a predetermined amount of pigment and / or ion conductive agent A was further added to this raw material mixture. Tetraalkylammonium perchlorate was used as the ion conductive agent A. The raw material mixture was foamed and cured by mixing in a mixer while blowing in an inert gas, to obtain a foam (equivalent to ENDUR, manufactured by Inoac Corporation). The density of the resulting foamed polyurethane was 12-50 pcf (192 kg / m). 3 ~800kg / m 3 ) and the Asker C hardness was 10 to 50°. The thickness of the substrate layer after cylindrical grinding was 3.5 to 5.5 mm.

[0071] [B. UEM-55 (Slab Urethane Foam A)] Polyol, isocyanate, foam stabilizer, water (blowing agent), resinification catalyst, and blowing catalyst were mixed in a predetermined ratio. If necessary, a predetermined amount of ion-conductive material A was further added to this mixture. The raw material mixture was poured into a mold and foamed to obtain a foam (equivalent to UEM-55, manufactured by Inoac Corporation). Tetraalkylammonium perchlorate was used as the ion-conductive material A. Next, pigment was added to some of the foams by impregnation. That is, the foam (slab) was made into a sheet, the sheet was cut, and holes for inserting shafts were made in the sheet. After that, the sheet was immersed in a dispersion liquid in which the pigment was dispersed in water. After a predetermined time had passed, the sheet was taken out of the dispersion liquid and dried. The density of the obtained polyurethane foam was 50 to 75 kg / m 3 The FP hardness was 40 to 80°. The thickness of the substrate layer after cylindrical polishing was 3.5 to 5.5 mm.

[0072] [C. EP-70 (Slab Urethane Foam B)] A block of EP-70 (manufactured by Inoac Corporation) was sliced ​​to 40 mm. The resulting sheet was then cut to a width of 40 mm and a length of 370 mm. A hole with a diameter of 13 mm was then drilled from the center of one end face (the 40 mm × 40 mm face) of the resulting strip (40 mm × 40 mm × 370 mm) toward the center of the other end face. Next, the perforated strips were immersed in a dispersion of pigment and a binder (a component that bonds the pigment to the urethane) in water, allowing the dispersion to soak into the air bubbles in the strips.The strips were then removed from the dispersion and dried at a temperature of 100°C or higher. Next, hot melt was applied to a separately prepared metal shaft and inserted into the hole in the rectangular strip. The rectangular strip with the shaft inserted was then heated to a temperature above the melting point of the hot melt. After heating for a predetermined time, the rectangular strip with the shaft inserted was cooled to near room temperature. Furthermore, the outer peripheral surface of the strip was polished using a cylindrical polishing machine. After cylindrical polishing, the thickness of the base layer was 3.5 to 5.5 mm.

[0073] [1.1.2. Preparation of primer layer] In Examples 1 to 6, a primer layer was formed on the outer peripheral surface of the substrate layer. A solvent-evaporating urethane primer (Nipporan (registered trademark) 5230, manufactured by Tosoh Corporation) was used as the raw material for the primer layer. A predetermined amount of the urethane primer was applied to the outer peripheral surface of the substrate layer and dried. The thickness of the obtained primer layer was 0.2 to 0.8 mm.

[0074] 1.1.3. Preparation of Elastomer Layer Next, an elastomer layer was formed on the outer peripheral surface of the primer layer (Examples 1 to 6) or the outer peripheral surface of the base layer (Comparative Examples 1 to 6). An ultraviolet-curable polyurethane elastomer was used for the elastomer layer. The details of the method for producing the elastomer layer are as follows.

[0075] [A. SC-22 (UV-curable polyurethane elastomer A)] A polyurethane prepolymer having a methacrylic group as a terminal functional group, ionic conductive agent B, polythiol, and a photopolymerization initiator were mixed in a specified ratio. The content of ionic conductive agent B was set to an amount equivalent to 3.0 mass% of the total mass of the cured elastomer layer. While the roller was rotating, the raw material was applied to the surface of the primer layer or the surface of the substrate layer using a doctor blade, and then cured by irradiating with ultraviolet light. After curing, the outer surface was polished with a cylindrical polisher to obtain an elastomer layer 2 mm thick.

[0076] The polyurethane prepolymer used was a prepolymer synthesized from AN-002 manufactured by Mitsui Chemicals Inc. and T-80 manufactured by Tosoh Corporation. As the ionic conductive agent B, Elegan LD-204 manufactured by NOF Corporation was used. As the polythiol, TMMP manufactured by SC Organic Chemical Co., Ltd. was used. As the photopolymerization initiator, OMNIRAD2959 manufactured by IGM RESINS BV was used.

[0077] [B. SC-23 (UV-curable polyurethane elastomer B)] An elastomer layer was formed in the same manner as in SC-22, except that the content of ion conductive agent B was set to 1.0 mass %.

[0078] [C. SC-23 Modified (UV-curable polyurethane elastomer C)] An elastomer layer was formed in the same manner as in SC-22, except that the content of ion conductive agent B was set to 0.1 mass %.

[0079] [1.1.4. Preparation of OC layer] After forming the elastomer layer, an OC layer (surface coating) was formed on the outer peripheral surface of the elastomer layer by applying BONDERITE (registered trademark) S-FN T-862A AN (manufactured by Henkel Japan) to a film thickness of 5 to 40 μm and drying it.

[0080] 1.2. Comparative Example 7 Acrylonitrile-butadiene rubber (NBR), epichlorohydrin rubber, pigment, foaming agent, crosslinking agent, vulcanization accelerator, vulcanization accelerator aid, and processing aid were mixed in a predetermined ratio to obtain a raw material composition. The obtained raw material composition was extrusion-molded to adhere a cylindrical molded body (hereinafter also referred to as a "base layer precursor") to the surface of the shaft. Separately, acrylonitrile-butadiene rubber (NBR), a vulcanization aid, a mold release agent, a vulcanizing agent, and a vulcanization accelerator were mixed in a predetermined ratio to obtain a raw material composition, which was then extrusion-molded to obtain a cylindrical molded body (hereinafter also referred to as "elastomer layer precursor").

[0081] The cylindrical elastomer layer precursor was set in a cylindrical roll-molding die. Next, the shaft on which the base layer precursor was formed was inserted into the elastomer layer precursor. In this state, the elastomer layer precursor and base layer precursor were heated at 160°C for 40 minutes to crosslink and foam the raw material composition. After cooling, the shaft with the substrate layer and elastomer layer was removed from the mold. The outer peripheral surface of the elastomer layer was then polished with a cylindrical polisher to obtain an elastomer layer with a thickness of 2 mm. Furthermore, in the same manner as in Example 1, an OC layer was formed on the surface of the elastomer layer.

[0082] 2. Test Method 2.1. Volume resistivity The volume resistivity of the roller after forming the base layer (hereinafter also referred to as the "volume resistivity of the base layer"), the volume resistivity of the roller after forming the elastomer layer (hereinafter also referred to as the "volume resistivity of the elastomer layer"), and the volume resistivity after further forming an OC layer (surface coating) on ​​the surface of the elastomer layer (hereinafter also referred to as the "volume resistivity of the OC layer") were measured. Note that the volume resistivity of the roller after forming the primer layer was not measured. Furthermore, the "volume resistivity of the base layer" of Comparative Example 7 was measured using a sample in which the base layer and elastomer layer were integrally formed and then the elastomer layer was removed by cylindrical polishing. The measurement conditions were a temperature of 22°C ± 3°C, a relative humidity of 55% ± 5%, and a voltage of 100V.

[0083] 2.2. Degree of cure and adhesion of elastomer layer The degree of cure and adhesion of the elastomer layer were evaluated visually.

[0084] [3. Results] The results are shown in Tables 1 and 2. Tables 1 and 2 also show the history of each sample. Regarding "imparting conductivity to the substrate," "◯" indicates that it was possible to impart conductivity to the substrate layer using either the pigment or the ionic conductive agent A, and "△" indicates that it was not possible to impart conductivity to the substrate layer using a conductive agent that turns the substrate layer black (i.e., carbon).

[0085] Regarding "hardening of elastomer layer," "◯" indicates that the elastomer layer is sufficiently hardened, and "Δ" indicates that the hardening of the elastomer layer at the interface on the substrate layer side is insufficient. Regarding "adhesion of elastomer layer," "◯" indicates that the elastomer layer is sufficiently adhered, and "×" indicates that peeling has occurred between the substrate layer and the elastomer layer.

[0086] Regarding "elastomer layer molding time," "◯" indicates that curing was possible in 5 to 600 seconds, and "×" indicates that curing required 600 seconds or more. Regarding the "conductive performance of the roller," "◯" indicates that the volume resistivity of the roller can be adjusted by the volume resistivity of the base layer and the volume resistivity of the elastomer layer, and that the adjustment range of the volume resistivity of the roller is wide. "△" indicates that the adjustment range of the volume resistivity is narrow. From Tables 1 and 2, the following can be seen:

[0087] (1) In Comparative Examples 3 to 6, the elastomer layer was not sufficiently cured. This is thought to be because the carbon contained in the substrate layer absorbed or blocked ultraviolet light, and the raw material was not sufficiently cured near the interface between the substrate layer and the elastomer layer. (2) In Comparative Examples 1 and 2, the elastomer layer was sufficiently cured. However, since the base layer did not contain a pigment (carbon), it was difficult to adjust the volume resistivity of the roller. (3) In Comparative Example 7, the base layer and elastomer layer were integrally formed, but crosslinking and foaming (i.e., formation of the elastomer layer) took as long as 40 minutes. In addition, the restoring force of the roller obtained in Comparative Example 7 was inferior to that of rollers using urethane-based materials for the base layer and elastomer layer.

[0088] (4) The elastomer layer was sufficiently cured in all of Examples 1 to 6. Furthermore, by controlling the type and amount of the pigment and ionic conductive agent A added to the base layer, the type and amount of ionic conductive agent B added to the elastomer layer, and the thickness of each layer, the volume resistivity of the roller could be adjusted to the desired value. (5) By interposing a primer layer between the substrate layer and the UV-curable elastomer layer, the substrate layer and the UV-curable elastomer layer could be bonded together regardless of the color of the substrate layer.

[0089] [Table 1]

[0090] [Table 2]

[0091] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the present invention. [Industrial Applicability]

[0092] The OA roll according to the present invention can be used as a transfer roller, a charging roller, a toner supply roller, a developing roller, a fixing roller, a paper feed roller, a paper discharge roller, etc. [Explanation of symbols]

[0093] 10 OA rolls 12 shafts 14 Base material layer 16 Primer layer 18 Elastomer layer

Claims

1. a conductive shaft; a base material layer formed on an outer circumferential surface of the shaft; a primer layer formed on the outer peripheral surface of the substrate layer; an elastomer layer formed on the outer peripheral surface of the primer layer; Equipped with the base layer includes a foamed resin and a pigment that absorbs ultraviolet light and is dispersed in the foamed resin; the primer layer contains a non-ultraviolet curable elastomer, The elastomer layer includes an ultraviolet curable elastomer. Office roller.

2. 2. The office automation roller according to claim 1, wherein the foamed resin is foamed polyurethane.

3. 3. The office automation roller according to claim 1, wherein the pigment is carbon.

4. The office automation roller according to claim 1 , wherein the base layer further contains an ion conductive agent A.

5. The office automation roller according to claim 1 , wherein the primer layer contains a polyurethane elastomer.

6. The elastomer layer comprises: a raw material containing a urethane prepolymer having an allyl group, a vinyl ether group, or an acrylate group as a terminal functional group and a polythiol having a thiol group is applied to the surface of the primer layer; The coating film made of the raw materials is irradiated with ultraviolet light to cause an enethiol reaction. The office automation roller according to claim 1 , further comprising an elastomer obtained by:

7. The office automation roller according to claim 1 , wherein the elastomer layer further contains an ion conductive agent B.

8. 8. The office automation roller according to claim 1, wherein the elastomer layer has a thickness of 0.5 mm or more and 5.0 mm or less.

9. 9. The office automation roller according to claim 1, wherein the thickness of the primer layer is greater than 0 mm and not greater than 0.8 mm.

10. 10. The office automation roller according to claim 1, wherein the volume resistivity is 3 (log Ω) or more and 10 (log Ω) or less.

11. 11. The office automation roller according to claim 1, wherein the office automation roller is a transfer roller, a charging roller, a toner supply roller, a developing roller, a fixing roller, a paper feed roller, or a paper discharge roller.

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