JP2007248601A - Conductive roller and image forming apparatus with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive roller improved in adhesion durability between laminated layers composed of an elastic layer and a coating film layer. <P>SOLUTION: The conductive roller comprises: a shaft member 2; the one or more elastic layers 3 disposed on the radially outside of the shaft member 2; and the one or more coating film layers 4 disposed on the radially outside of the elastic layer 3; and a primer layer 5 formed at least in one area between the elastic layer 3 and coating film layer 4 stuck together. In this case, the primer layer 5 and the elastic layer 3 and/or coating film layer 4 adjacent to the primer layer 5 are made of an ultraviolet curing resin obtained by curing an ultraviolet curing material mixture by means of ultraviolet radiation. The material mixture having the viscosity of ≤100 mPa s is used for forming the primer layer 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a conductive roller having an elastic layer and a coating layer, and an image forming apparatus provided with the conductive roller, and in particular, a conductive roller having high adhesion durability between laminated layers composed of an elastic layer and a coating layer. It is about.

  In general, in an electrophotographic image forming apparatus such as a copying machine, a facsimile, or a laser beam printer (LBP), a developing roller, a charging roller, a toner supply roller, a transfer roller, a paper feeding roller, a cleaning roller, and a pressure for fixing. As a roller or the like, a roll-shaped conductive elastic member, that is, a conductive roller is frequently used, and the conductive roller is usually mounted with a shaft member supported by both ends in the length direction, and the shaft member. And one or more elastic layers disposed on the outside in the radial direction. In some cases, the conductive roller further includes a coating layer on the surface of the elastic layer for the purpose of controlling chargeability and adhesion to toner, preventing contamination of the photosensitive drum by the elastic layer, and the like.

  For the shaft member of the conductive roller, various resins such as engineering plastics are used in addition to metals such as iron and stainless steel. The elastic layer of the conductive roller uses an elastomer such as silicone rubber, acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber (EPDM), epichlorohydrin rubber (ECO), polyurethane, It is manufactured by injecting an elastomer raw material into a mold having a desired cavity shape and heating it to heat cure the elastomer raw material. Further, the coating layer is formed by dipping the roller body composed of the shaft member and the elastic layer into a solvent-based or aqueous coating liquid containing resin or spraying the coating liquid on the roller body, It is formed by drying and curing with hot air. Here, since long time drying is required for the formation of the coating layer, a long drying line is necessary for mass production, and the coating layer requires delicate conductivity and surface condition from its application. However, there is a problem in quality because variations in temperature distribution and air volume in the drying line greatly affect the performance of the coating layer.

  On the other hand, as a method of forming a stable quality coating layer without requiring a long drying line, an ultraviolet curable resin material is applied to the surface of the elastic layer of the roller, and the resin material is cured, A technique for forming a coating layer made of an ultraviolet curable resin on the surface of an elastic layer has been proposed (see Patent Document 1).

JP 2002-310136 A

  In general, a conductive roller using an ultraviolet curable resin for a coating layer is manufactured by laminating a plurality of coating layers on the order of several microns on the surface of an elastic layer having a thickness of 1 mm or more. However, in this configuration, the degree of distortion with respect to the stress in each layer is different, and the followability to deformation in the elastic layer and the entire coating layer becomes low. Therefore, when such a conductive roller is used continuously in an image forming apparatus, There are problems relating to the durability of the roller such as coating film cracking and coating film scraping.

  Moreover, in the said structure, since the adhesiveness between lamination | stacking which consists of an elastic layer and a coating film layer is not ensured, there exists a possibility that a coating film layer may peel from an elastic layer at the time of use.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a conductive roller that solves the above-mentioned problems of the prior art and has improved adhesion durability between laminated layers composed of an elastic layer and a coating layer. Another object of the present invention is to provide an image forming apparatus that can stably form a good image using such a conductive roller.

  As a result of intensive investigations to achieve the above object, the present inventors have found that a primer layer formed from an ultraviolet curable raw material mixture is disposed between the layers composed of an elastic layer and a coating layer, thereby providing elasticity. The present inventors have found that a conductive roller excellent in adhesion durability between the laminate composed of a layer and a coating layer can be obtained, and have completed the present invention.

That is, the conductive roller of the present invention comprises a shaft member, one or more elastic layers disposed radially outside the shaft member, and one or more coating films disposed radially outward of the elastic layer. A conductive roller comprising a layer,
A primer layer is further provided in at least one place between the elastic layer and the elastic layer, between the elastic layer and the coating layer and between the coating layer and the coating layer,
The primer layer and the elastic layer and / or the coating layer adjacent to the primer layer are made of an ultraviolet curable resin obtained by curing an ultraviolet curable raw material mixture by ultraviolet irradiation,
The material mixture used for forming the primer layer has a viscosity of 100 mPa · s or less.

  In a preferred embodiment of the conductive roller of the present invention, the raw material mixture used for forming the primer layer contains a monomer and a diluting solvent.

  In another preferred embodiment of the conductive roller of the present invention, the raw material mixture used for forming the primer layer does not contain an oligomer.

  In the conductive roller of the present invention, the raw material mixture used for forming the primer layer is at least one polarity selected from the group consisting of a monomer having a heterocyclic group, a monomer having a hydroxyl group, and a monomer having a carboxyl group. It is preferable that a group-containing monomer is included, and it is more preferable that the monomer having a heterocyclic group has a morpholino group. Here, it is particularly preferable that the raw material mixture used for forming the primer layer contains at least one diluent solvent selected from the group consisting of propylene glycol monomethyl ether acetate (PMA), methyl ethyl ketone (MEK), acetone and butyl lactate. .

  Furthermore, in the conductive roller of the present invention, when the raw material mixture used for forming the primer layer contains a monomer and a diluent solvent, the monomer preferably contains a metal acrylate. Here, it is further preferable that the dilution solvent is water and / or alcohol.

  In the conductive roller of the present invention, when the raw material mixture used for forming the primer layer contains a monomer and a diluent solvent, the monomer content in the raw material mixture is preferably in the range of 5 to 70% by mass. .

  The image forming apparatus of the present invention is characterized by using the conductive roller.

  According to the present invention, an ultraviolet curable raw material mixture is provided at least in one place between the elastic layer and the elastic layer, between the elastic layer and the coating layer, and between the coating layer and the coating layer. By disposing the primer layer formed from the above, it is possible to provide a conductive roller having high adhesion durability between the laminated layers composed of the elastic layer and the coating layer. Further, it is possible to provide an image forming apparatus that includes such a conductive roller and can stably form a good image.

<Conductive roller>
Below, the conductive roller of this invention is demonstrated in detail, referring a figure. FIG. 1 is a cross-sectional view of one embodiment of the conductive roller of the present invention. The conductive roller 1 in the illustrated example includes a shaft member 2, an elastic layer 3 disposed on the outer side in the radial direction of the shaft member 2, and a coating layer 4 disposed on the outer side in the radial direction of the elastic layer 3. , And a primer layer 5 disposed between the elastic layer 3 and the coating layer 4. The conductive roller 1 shown in FIG. 1 has only one elastic layer 3, but the conductive roller of the present invention may have two or more elastic layers. Further, the conductive roller 1 shown in FIG. 1 has only one coating layer 4, but the conductive roller of the present invention can also have two or more coating layers as shown in FIG.

  FIG. 2 is a cross-sectional view of another embodiment of the conductive roller of the present invention. The conductive roller 6 in the illustrated example includes two coating film layers 7a and 7b disposed on the radially outer side of the elastic layer 3, instead of the coating film layer 4 shown in FIG. And a primer layer 8 disposed between the layer 7a and between the coating layer 7a and the coating layer 7b. Moreover, the same code | symbol as FIG. 1 shows that it is the same member. The primer layer 8 in FIG. 2 is disposed between the laminated layers composed of the elastic layer 3 and the coating layers 7a and 7b. In the conductive roller of the present invention, the primer layer is provided at least at one place. It only has to have.

  Here, in the conductive roller of the present invention, the primer layers 5 and 8 and the elastic layer 3 and / or the coating layers 4, 7a and 7b adjacent to the primer layers 5 and 8 are made of an ultraviolet curable raw material mixture. It is made of an ultraviolet curable resin cured by irradiation, and the viscosity of the raw material mixture used for forming the primer layers 5 and 8 is 100 mPa · s or less. When the viscosity of the raw material mixture used for forming the primer layer is 100 mPa · s or less, the primer layer made of an ultraviolet curable resin obtained by curing the raw material mixture by ultraviolet irradiation has a layer thickness of less than 1 μm. It is formed as a thin layer with little thickness. For this reason, the primer layer has no fear of causing a phenomenon such as surface cracks caused by problems such as hardening of the primer layer due to its thickness and deterioration of followability to deformation. Therefore, the conductive roller of the present invention provided with such a primer layer can improve the adhesion durability between the laminated layers composed of the elastic layer and the coating layer.

  The ultraviolet curable raw material mixture used for forming the primer layer requires that the raw material mixture has a viscosity of 100 mPa · s or less, and preferably 50 mPa · s or less. When the viscosity of the raw material mixture for the primer layer exceeds 100 mPa · s, the thickness of the primer layer increases, poor adhesion between the primer layer and the elastic layer and / or coating layer adjacent to the primer layer, It causes adverse effects such as deterioration of surface shape and increased hardness.

  In the primer layer, from the viewpoint of enhancing the adhesion durability of the elastic layer and / or the coating layer adjacent to the primer layer, the ultraviolet curable raw material mixture used for forming the primer layer contains a monomer and a diluent solvent. It is preferable to include. Here, when the monomer is diluted with a diluting solvent, the primer layer made of an ultraviolet curable resin obtained by curing the raw material mixture by ultraviolet irradiation is formed as a very thin layer having almost no thickness. From the same viewpoint, it is also preferable that the ultraviolet curable raw material mixture does not contain an oligomer. When the raw material mixture which does not contain an oligomer is used, the thickness of the primer layer can be suppressed. By using the primer layer having almost no thickness formed in this way for the conductive roller of the present invention, poor adhesion between the primer layer and the elastic layer and / or coating layer adjacent to the primer layer, Defects such as deterioration of the surface shape of the primer layer and increase in hardness can be prevented.

  Preferable examples of the monomer used for forming the primer layer include polar group-containing monomers such as a monomer having a heterocyclic group, a monomer having a hydroxyl group, and a monomer having a carboxyl group. These polar group-containing monomers may be used alone or in combination of two or more.

  The monomer having a heterocyclic group is required to have a heterocyclic ring in the molecule, and preferably has a (meth) acryloyloxy group in order to be cured with ultraviolet rays. Here, examples of the heterocyclic group include a morpholino group, an isocyanurate group, a furyl group, and a phthaloyl group, and among these, a morpholino group is preferable. Specific examples of the monomer having a heterocyclic group include morpholine acrylate, morpholine methacrylate, tris (2-hydroxylethyl) isocyanurate triacrylate, tetrahydrofurfuryl (meth) acrylate, and 2-acryloyloxyethyl hexahydro. Examples thereof include phthalic acid, and among these, morpholine acrylate and morpholine methacrylate are preferable. These monomers having a heterocyclic group may be used alone or in combination of two or more.

  The monomer having a hydroxyl group is required to have a hydroxyl group in the molecule, and preferably has a (meth) acryloyloxy group in order to be cured with ultraviolet rays. Specific examples of such a monomer having a hydroxyl group include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, pentaerythritol triacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2- Examples thereof include hydroxybutyl methacrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-acryloyloxyethyl acid phosphate and the like. These monomers having a hydroxyl group may be used alone or in combination of two or more.

  The monomer having a carboxyl group is required to have a carboxyl group in the molecule, and preferably has a (meth) acryloyloxy group in order to be cured with ultraviolet rays. Specific examples of such a monomer having a carboxyl group include β- (meth) acryloyloxyethyl hydrogen succinate, β- (meth) acryloyloxypropyl hydrogen succinate, β- (meth) acryloyloxyethyl hydrogen phthalate. , Β- (meth) acryloyloxypropyl hydrogen phthalate, β- (meth) acryloyloxyethyl hydrogen tetrahydrophthalate, β- (meth) acryloyloxypropyl hydrogen tetrahydrophthalate, β- (meth) acryloyloxyethyl hydrogen hexa Examples thereof include hydrophthalate, β- (meth) acryloyloxypropyl hydrogen hexahydrophthalate, β-tris (acryloyloxymethyl) ethyl hydrogen phthalate, and the like. These monomers having a carboxyl group may be used alone or in combination of two or more.

  Moreover, as a monomer used for formation of the said primer layer, a metal containing acrylate other than the said polar group containing monomer can be mentioned suitably. The metal-containing acrylate needs to have a metal ion in the molecule, and examples of the ion include zinc ion, palladium ion, copper ion, iron ion, platinum ion, and ferrocene. Moreover, as said metal containing acrylate, a commercial item can be utilized, for example, brand name SR9016 [Cartomer company make, metal diacrylate] etc. are mentioned.

  Suitable examples of the dilution solvent include water and organic solvents such as alcohols, ethers, ketones and esters. These diluent solvents may be used alone or in combination of two or more. Specific examples of the dilution solvent when using a polar group-containing monomer as the monomer include propylene glycol monomethyl ether acetate (PMA), methyl ethyl ketone (MEK), acetone, and butyl lactate. Furthermore, specific examples of the dilution solvent when using a metal-containing acrylate as a monomer include water, methanol, ethanol, and the like.

  When the ultraviolet curable raw material mixture used for forming the primer layer contains a monomer and a diluent solvent, the content of the monomer in the raw material mixture is preferably in the range of 5 to 70% by mass. When the monomer content in the raw material mixture for the primer layer exceeds 70% by mass, the primer layer has a thickness, and between the primer layer and the elastic layer and / or coating layer adjacent to the primer layer. It causes adverse effects such as poor adhesion, deterioration of the surface shape of the primer layer and increased hardness. On the other hand, if the content of the monomer in the primer layer raw material mixture is less than 5% by mass, it is difficult to sufficiently secure the adhesion durability between the laminate composed of the elastic layer and the coating layer.

  The ultraviolet curable raw material mixture used for forming the elastic layer and / or the coating layer adjacent to the primer layer preferably contains an acrylate oligomer. Preferred examples of the acrylate oligomer include urethane acrylate oligomers, epoxy acrylate oligomers, ether acrylate oligomers, ester acrylate oligomers, polycarbonate acrylate oligomers, fluorine acrylate oligomers, and silicone acrylate oligomers. The acrylate oligomer is produced by a reaction of acrylic acid with polyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, bisphenol A type epoxy resin, phenol novolac type epoxy resin, adduct of polyhydric alcohol and ε-caprolactone, etc. Alternatively, it can be synthesized by urethanizing a polyisocyanate compound and an acrylate compound having a hydroxyl group.

  The urethane acrylate oligomer can be obtained by urethanizing a polyol, an isocyanate compound, and an acrylate compound having a hydroxyl group. The epoxy acrylate oligomer is preferably a reaction product of a compound having a glycidyl group and acrylic acid, and has a cyclic structure such as a benzene ring, a naphthalene ring, a spiro ring, dicyclopentadiene, tricyclodecane, and the like. A reaction product of a compound having a glycidyl group and acrylic acid is more preferable. Furthermore, the ether-based acrylate oligomer, ester-based acrylate oligomer and polycarbonate-based acrylate oligomer can be obtained by reacting polyol (polyether polyol, polyester polyol and polycarbonate polyol) with acrylic acid.

  In addition to the acrylate oligomer, a reactive diluent is added to the ultraviolet curable raw material mixture used for forming the elastic layer and / or coating layer adjacent to the primer layer in order to adjust the viscosity of the raw material mixture. May be used. Such reactive diluents include acrylate monomers such as ethyl acrylate, isobutyl acrylate, n-butyl acrylate, isoamyl acrylate, methoxytriethylene glycol acrylate, lauryl acrylate, isomyristyl acrylate, stearyl acrylate, myristyl acrylate, palmityl acrylate. Etc. are preferred. These acrylate monomers may be used alone or in combination of two or more.

  Further, the ultraviolet curable raw material mixture used for forming the elastic layer and / or the coating layer adjacent to the primer layer contains, in addition to the acrylate oligomer and the reactive diluent, the monomer used for forming the primer layer described above. May be. In the conductive roller of the present invention, the elastic layer and coating layer other than the elastic layer and / or coating layer adjacent to the primer layer are not particularly limited, and the elastic layer and coating layer adjacent to the primer layer are not limited. It may be the same or different.

  In addition, a conductive agent may be added to the ultraviolet curable raw material mixture used for forming the elastic layer and / or the coating layer adjacent to the primer layer in order to impart conductivity. Examples thereof include ionic conductive agents and electronic conductive agents. Examples of ionic conducting agents include tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and modified fatty acid dimethylethylammonium perchlorate, chlorate, hydrochloride, bromate, iodine Ammonium salts such as acid salts, borofluoride salts, sulfate salts, ethyl sulfate salts, carboxylate salts, sulfonate salts; alkali metals such as lithium, sodium, potassium, calcium, magnesium, and perchloric acids of alkaline earth metals Salt, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, trifluoromethyl sulfate, sulfonate, and the like. Conductive carbon such as acetylene black, SAF, I Carbon black for rubber such as AF, HAF, FEF, GPF, SRF, FT, MT, carbon black for color with oxidation treatment, pyrolytic carbon black, natural graphite, artificial graphite, antimony-doped tin oxide, ITO, oxidation Metal oxides such as tin, titanium oxide and zinc oxide, metals such as nickel, copper, silver and germanium, conductive polymers such as polyaniline, polypyrrole and polyacetylene, carbon whiskers, graphite whiskers, titanium carbide whiskers, conductive potassium titanate Examples include whiskers, conductive barium titanate whiskers, conductive titanium oxide whiskers, and conductive zinc oxide whiskers. The usage-amount of these electrically conductive agents can be suitably adjusted so that an elastic layer and a coating-film layer may have desired electroconductivity.

  The ultraviolet curable raw material mixture used for forming the coating layer adjacent to the primer layer may further contain fine particles. By including fine particles in the raw material mixture of the coating layer, appropriate minute irregularities can be formed on the surface of the conductive roller. As the fine particles, inorganic fine particles such as fine particles made of rubber, urethane or synthetic resin, fine particles made of carbon and silica fine particles are preferable. Silicone rubber, silicone resin, fluororesin, urethane resin, polyolefin resin, epoxy resin, polystyrene resin Epoxy resin, polystyrene resin, urethane acrylate, melamine resin, phenol resin, (meth) acrylic resin, glassy carbon fine particles and silica fine particles are particularly preferable. These fine particles may be used alone or in combination of two or more. Further, the content of the fine particles is preferably in the range of 0.1 to 100 parts by mass with respect to 100 parts by mass in total of the monomer and the oligomer.

  The ultraviolet curable raw material mixture used for forming the primer layer and the elastic layer and / or coating layer adjacent to the primer layer preferably further contains a photopolymerization initiator, a photosensitizer and the like. The photopolymerization initiator has an action of initiating polymerization of the above-described monomers and oligomers when irradiated with ultraviolet rays. Examples of the photopolymerization initiator include 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid ester, 2,2-dimethoxy-2-phenylacetophenone, acetophenone diethyl ketal, alkoxyacetophenone, benzyldimethyl ketal, benzophenone and 3,3. -Dimethyl-4-methoxybenzophenone, benzophenone derivatives such as 4,4-dimethoxybenzophenone, 4,4-diaminobenzophenone, benzoylalkyl benzoate, bis (4-dialkylaminophenyl) ketone, benzyl derivatives such as benzyl and benzylmethyl ketal Benzoin derivatives such as benzoin and benzoin isobutyl ether, benzoin isopropyl ether, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, xanthone Thioxanthone and thioxanthone derivatives, fluorene, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) ) -Phenylphosphine oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1,2-benzyl-2-dimethylamino-1- (morpholinophenyl) -butanone-1, etc. These photopolymerization initiators may be used alone or in combination of two or more. The blending amount of the photopolymerization initiator in the ultraviolet curable raw material mixture is preferably in the range of 0.2 to 5.0 parts by mass with respect to 100 parts by mass in total of the monomer and the oligomer. On the other hand, the photosensitizer absorbs energy by being irradiated with ultraviolet rays, and has the function of initiating polymerization by transferring the energy or electrons to the initiator. Examples of the photosensitizer include p-dimethylaminobenzoic acid isoamyl ester.

  The elastic layer of the conductive roller of the present invention is not particularly limited, but the elastic layer preferably has an Asker C hardness of 80 degrees or less, more preferably 20 to 70 degrees. . If the Asker C hardness of the elastic layer exceeds 80 degrees, the contact area between the conductive roller and the photosensitive drum may be reduced, and good development may not be performed. Also, the toner may be damaged and the photosensitive drum or the stratified blade may be damaged. The toner sticks and the like occurs and image defects are likely to occur. On the other hand, if the elastic layer is too low in hardness, the frictional force with the photosensitive drum or the stratified blade increases, which may cause image defects such as jitter.

  The shaft member of the conductive roller of the present invention is not particularly limited as long as it has good conductivity. For example, a metal core made of a metal solid body, a metal cylindrical body hollowed inside, or a high rigidity Examples thereof include a cylindrical body made of resin, and a composite body in which a high-rigidity resin is arranged on the outer periphery of a core metal. In addition, when using highly rigid resin for a shaft member, it is preferable to ensure sufficient electroconductivity by adding and disperse | distributing a electrically conductive agent to highly rigid resin. Here, as the conductive agent dispersed in the high-rigidity resin, carbon black powder, graphite powder, carbon fiber, metal powder such as aluminum, copper and nickel, metal oxide powder such as tin oxide, titanium oxide and zinc oxide, conductive A powdery conductive agent such as conductive glass powder is preferred. These electrically conductive agents may be used individually by 1 type, and may be used in combination of 2 or more type. Although the compounding quantity of this electrically conductive agent is not restrict | limited in particular, The range of 5-40 mass% is preferable with respect to the whole highly rigid resin, and the range of 5-20 mass% is still more preferable.

  Examples of the material for the metal core bar and the metal cylinder include iron, stainless steel, and aluminum. The material of the high-rigidity resin base material is polyacetal, polyamide 6, polyamide 6 · 6, polyamide 12, polyamide 4 · 6, polyamide 6 · 10, polyamide 6 · 12, polyamide 11, polyamide MXD6, polybutylene. Terephthalate, polyphenylene oxide, polyphenylene sulfide, polyethersulfone, polycarbonate, polyimide, polyamideimide, polyetherimide, polysulfone, polyetheretherketone, polyethylene terephthalate, polyarylate, liquid crystal polymer, polytetrafluoroethylene, polypropylene, ABS resin, polystyrene , Polyethylene, melamine resin, phenol resin, silicone resin and the like. Among these, polyacetal, polyamide 6/6, polyamide MXD6, polyamide 6/12, polybutylene terephthalate, polyphenylene ether, polyphenylene sulfide, and polycarbonate are preferable. These high-rigidity resins may be used alone or in combination of two or more.

  The conductive roller 1 of the present invention is formed by, for example, applying the elastic layer raw material mixture to the outer surface of the shaft member 2 and then irradiating with ultraviolet rays to form the elastic layer 3, and then the outer surface of the elastic layer 3. After applying the primer layer raw material mixture, the primer layer 5 is formed by irradiation with ultraviolet rays, and finally the coating layer raw material mixture is applied and then the ultraviolet ray irradiation is performed to form the coating layer 4. it can. In this case, by using the above-described monomer having high adhesiveness for the primer layer raw material mixture, the coating layer is not particularly limited, and a compound having excellent desired physical properties can be used. Also, the conductive roller 6 of the present invention can be manufactured by repeating the same procedure. In addition, as a method of apply | coating various raw material mixtures to the outer surface of a shaft member and the outer surface of an elastic layer, a primer layer, and a coating film layer, a spray method, a roll coater method, a dipping method, a die coating method etc. are mentioned. Examples of the light source used for ultraviolet irradiation include a mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, and a xenon lamp. The conditions for ultraviolet irradiation are appropriately selected according to the components contained in the various raw material mixtures, the coating amount, and the like, and the irradiation intensity and the integrated light amount may be adjusted as appropriate.

  The conductive roller of the present invention described above can be used as a developing roller, a charging roller, a toner supply roller, a transfer roller, a paper feed roller, a cleaning roller, a fixing pressure roller, and the like of an image forming apparatus.

<Image forming apparatus>
The image forming apparatus of the present invention includes the conductive roller described above. The image forming apparatus of the present invention is not particularly limited except that the conductive roller is used, and can be manufactured by a known method.

  The image forming apparatus of the present invention will be described in detail below with reference to the drawings. FIG. 3 is a partial cross-sectional view of one embodiment of the image forming apparatus of the present invention. The image forming apparatus in the illustrated example supplies a photosensitive drum 9 that holds an electrostatic latent image, a charging roller 10 that is positioned near (upward in the drawing) of the photosensitive drum 9 and charges the photosensitive drum 9, and toner 11. A toner supply roller 12, a developing roller 13 disposed between the toner supply roller 12 and the photosensitive drum 9, a developing blade 14 provided in the vicinity of the developing roller 13 (upward in the drawing), and a photosensitive drum. 9 is provided with a transfer roller 15 positioned near (lower in the drawing) 9 and a cleaning roller 16 disposed adjacent to the photosensitive drum 9. The image forming apparatus of the present invention can further include known components (not shown) that are normally used in the image forming apparatus.

  In the illustrated image forming apparatus, the charging roller 10 is brought into contact with the photosensitive drum 9 and a voltage is applied between the photosensitive drum 9 and the charging roller 10 to charge the photosensitive drum 9 to a constant potential. Then, an electrostatic latent image is formed on the photosensitive drum 9 by an exposure machine (not shown). Next, the photosensitive drum 9, the toner supply roller 12, and the developing roller 13 rotate in the direction of the arrow in the figure, so that the toner 11 on the toner supply roller 12 is sent to the photosensitive drum 9 through the developing roller 13. It is done. The toner 11 on the developing roller 13 is adjusted to a uniform thin layer by the developing blade 14 and rotates while the developing roller 13 and the photosensitive drum 9 are in contact with each other, so that the toner 11 is transferred from the developing roller 13 to the photosensitive drum 9. It adheres to the electrostatic latent image and the latent image becomes visible. The toner 11 attached to the latent image is transferred to a recording medium such as paper by the transfer roller 15, and the toner 11 remaining on the photosensitive drum 9 after the transfer is removed by the cleaning roller 16. Here, in the image forming apparatus of the present invention, for example, at least one of the charging roller 10, the toner supply roller 12, the developing roller 13, the transfer roller 15, and the cleaning roller 16, the elastic layer 3 and the coating layer 4 described above. Alternatively, it is possible to stably form an excellent image by using the conductive roller 1 or 6 having excellent adhesion durability between the laminated layers composed of the elastic layer 3 and the coating layers 7a and 7b. .

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Examples 1-5)
A raw material mixture for an elastic layer having the composition shown in Table 1 is thickened by a die coater on a polybutylene terephthalate (PBT) resin roller base material (shaft member) having an outer diameter of 17.0 mm into which a metal shaft having an outer diameter of 6.0 mm is inserted. The film was applied at 1500 μm, and irradiated with UV irradiation at a UV irradiation intensity of 700 mW / cm ² for 5 seconds while rotating in a nitrogen atmosphere to obtain a roller body provided with an elastic layer.

On the surface of the roller body, a primer layer raw material mixture having the composition shown in Table 1 was applied by a roll coater, and the primer layer was irradiated with UV at an irradiation intensity of 700 mW / cm ² for 3 seconds while rotating in a nitrogen atmosphere. Formed. Next, a coating layer raw material mixture having the composition shown in Table 1 was applied to the surface of the primer layer with a roll coater, and UV irradiation was performed for 5 seconds at a UV irradiation intensity of 700 mW / cm ² while rotating in a nitrogen atmosphere. A conductive roller provided with a coating layer having a thickness of 10 μm on the surface was obtained.

(Example 6)
A conductive roller having the structure shown in FIG. 2 was produced in the same manner as in Example 1 using the elastic layer raw material mixture, the primer layer raw material mixture, and the coating layer raw material mixture shown in Table 2.

(Comparative Example 1)
Using the raw material mixture for elastic layer and the raw material mixture for coating layer shown in Table 1, a conductive roller having the structure shown in Table 1 was produced in the same manner as in Example 1.

(Comparative Example 2)
Using the raw material mixture for elastic layer and the raw material mixture for coating layer shown in Table 2, a conductive roller having the structure shown in Table 2 was produced in the same manner as in Example 1.

  Next, in order to evaluate the adhesion durability between the laminated layers composed of the elastic layer and the coating layer of the obtained conductive roller, the surface after the conductive roller is incorporated into an image forming apparatus and printed 5000 sheets The state of shaving and peeling of the coating layer was tested. The results are shown in Tables 1 and 2, respectively.

* 1 Urethane acrylate, manufactured by Nippon Synthetic Chemical Co., Ltd.
* 2 Methoxytriethylene glycol acrylate, manufactured by Kyoeisha Chemical Co., Ltd.
* 3 Shin-Nakamura Chemical Co., Ltd., β-acryloyloxyethyl hydrogen succinate, CH ₂ = CHCOOCH ₂ CH ₂ OCOCH ₂ CH ₂ COOH.
* 4 1-hydroxycyclohexyl phenyl ketone, manufactured by Ciba Specialty Chemicals.
* 5 Sodium perchlorate polyol complex salt, manufactured by Akishima Chemical Co., Ltd.
* 6 Shin-Nakamura Chemical Co., Ltd., morpholine acrylate.
* 7 Kyoeisha Chemical Co., Ltd. 2-hydroxyethyl acrylate.
* 8 Tris (2-hydroxylethyl) isocyanurate triacrylate, manufactured by Sartomer.
* 9 Metal diacrylate, manufactured by Sartomer.
* 10 Propylene glycol monomethyl ether acetate.
* 11 Urethane acrylate, manufactured by Kyoeisha Chemical Co., Ltd.
* 12 1,6-hexanediol diacrylate, manufactured by Kyoeisha Chemical Co., Ltd.
* 13 Carbon, manufactured by Mitsubishi Chemical Corporation.
* 14 2,4-Diethylthioxanthone manufactured by Nippon Kayaku Co., Ltd.
* 15 Isoamyl ester of p-dimethylaminobenzoic acid manufactured by Nippon Kayaku Co., Ltd.
* 16 Urethane acrylate, manufactured by Nippon Synthetic Chemical Co., Ltd.
* 17 Phenoxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.

  From Tables 1 and 2, the conductive roller provided with a primer layer having a viscosity of the raw material mixture of 100 mPa · s or less has good results for both surface scraping and peeling of the coating layer after continuous printing. It turns out that the adhesive durability between lamination | stacking which consists of a coating-film layer is high.

  Moreover, from Examples 1-6, it turns out that adhesion durability was improved although the monomer with high adhesiveness was not contained in the coating-film layer used for the electroconductive roller. Furthermore, it can be seen from Example 6 that adhesion durability can be ensured even if the components of the raw material mixture of the two-layer coating layer are different.

It is sectional drawing of one embodiment of the electroconductive roller of this invention. It is sectional drawing of the other embodiment of the conductive roller of this invention. 1 is a partial cross-sectional view of an embodiment of an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive roller 2 Shaft member 3 Elastic layer 4 Coating layer 5 Primer layer 6 Conductive roller 7a Coating layer 7b Coating layer 8 Primer layer 9 Photosensitive drum 10 Charging roller 11 Toner 12 Toner supply roller 13 Developing roller 14 Developing blade 15 Transfer roller 16 Cleaning roller

Claims (10)

In a conductive roller comprising a shaft member, one or more elastic layers disposed radially outward of the shaft member, and one or more coating layers disposed radially outward of the elastic layer,
A primer layer is further provided in at least one place between the elastic layer and the elastic layer, between the elastic layer and the coating layer and between the coating layer and the coating layer,
The primer layer and the elastic layer and / or the coating layer adjacent to the primer layer are made of an ultraviolet curable resin obtained by curing an ultraviolet curable raw material mixture by ultraviolet irradiation,
A conductive roller, wherein a viscosity of a raw material mixture used for forming the primer layer is 100 mPa · s or less.   The conductive roller according to claim 1, wherein the raw material mixture used for forming the primer layer includes a monomer and a diluting solvent.   The conductive roller according to claim 1, wherein the raw material mixture used for forming the primer layer does not contain an oligomer.   The conductive monomer according to claim 2, wherein the monomer is at least one polar group-containing monomer selected from the group consisting of a monomer having a heterocyclic group, a monomer having a hydroxyl group, and a monomer having a carboxyl group. Sex roller.   The conductive roller according to claim 4, wherein the monomer having a heterocyclic group has a morpholino group.   The conductive roller according to claim 4, wherein the dilution solvent is at least one dilution solvent selected from the group consisting of propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, and butyl lactate.   The conductive roller according to claim 2, wherein the monomer includes a metal-containing acrylate.   The conductive roller according to claim 7, wherein the dilution solvent is water and / or alcohol.   The conductive roller according to claim 2, wherein the monomer content in the raw material mixture used for forming the primer layer is in the range of 5 to 70 mass%.   An image forming apparatus comprising the conductive roller according to claim 1.

Images