JP4298592B2 - Developing roller and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a developing roller and an image forming apparatus provided with the developing roller, and more particularly to a developing roller used in an electrophotographic apparatus such as a copying machine and a printer, and an image forming apparatus such as an electrostatic recording apparatus.

  In an electrophotographic image forming apparatus such as a copying machine or a printer, as a developing method for visualizing a latent image by supplying toner to a photosensitive drum or the like holding a latent image and attaching the toner to the latent image on the photosensitive drum. A pressure development method is known. In the pressure development method, for example, development is performed by bringing a developing roller carrying toner into contact with a photosensitive drum holding an electrostatic latent image and attaching the toner to the latent image on the photosensitive drum. Therefore, it is necessary to form the developing roller with a conductive elastic body. Such a conductive elastic roller is also used in a toner jet method using an aperture electrode by providing a minute gap between the photosensitive drum and the developing roller to fly the toner.

  In the above pressure development method, the developing roller must rotate while securely holding the state in close contact with the photosensitive drum. Therefore, silicone rubber, acrylonitrile-butadiene are placed on the outer periphery of the shaft made of a highly conductive material such as metal. Semiconductive elastic body in which carbon black or metal powder is dispersed in an elastomer such as rubber (NBR), ethylene-propylene-diene rubber (EPDM), epichlorohydrin rubber (ECO), polyurethane or the like, and a foam in which these are foamed It has a structure in which a semiconductive elastic layer made of is formed. Further, a resin coating layer may be further formed on the surface of the elastic layer for the purpose of controlling the charging property and adhesion to the toner and preventing the photosensitive drum from being contaminated by the elastic layer of the developing roller.

  Conventionally, the resin coating layer is formed by dipping the developing roller into a solvent-based or aqueous coating solution or spraying the coating solution onto the developing roller, followed by drying and curing with heat or hot air. In this case, since long time drying is required, a long drying line is necessary for mass production. In addition, the resin coating layer is required to have subtle electrical conductivity and surface condition depending on its use, but the quality distribution is affected by variations in temperature distribution and air volume in the drying line, which greatly affects the performance of the resin coating layer. There was a problem.

  On the other hand, as a method for forming a resin coating layer having a stable quality without requiring a long drying line, an ultraviolet curable compound is applied to the surface of the elastic layer of the developing roller, and the compound is cured to form a resin coating layer. Has been proposed (see Patent Document 1).

JP 2002-310136 A

  However, since the resin coating layer formed by applying an ultraviolet curable compound and curing the compound with ultraviolet rays contains an unreacted compound, the photosensitive drum may be contaminated. In particular, when a carbon-based electronic conductive agent is blended to adjust the electrical resistance of the resin coating layer, the carbon-based electronic conductive agent absorbs ultraviolet rays, so that the ultraviolet curable compound does not sufficiently undergo a curing reaction, There was a problem that the reaction compound easily remained. In addition, the developing roller provided with a resin coating layer formed by ultraviolet curing on the outer peripheral surface of the elastic layer has a problem that the roller surface is easily worn depending on use conditions because the frictional resistance of the roller surface is large. Therefore, when an image forming apparatus incorporating such a developing roller is used for a long time, there is a problem that the surface of the developing roller is scraped and image defects are likely to occur.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developing roller that solves the above-mentioned problems of the prior art, does not contaminate the photosensitive drum, is difficult to scrape even after long use, and has excellent durability. . Another object of the present invention is to provide an image forming apparatus provided with such a developing roller and capable of forming a good image over a long period of time.

  As a result of intensive studies to achieve the above object, the present inventors have found that in a developing roller in which a resin coating layer is disposed on the surface of the elastic layer, a non-electron beam curable silicon-containing resin and / or Alternatively, by using a compound and an electron beam curable resin, the remaining amount of unreacted compound can be reduced, the frictional resistance of the roller surface is reduced, and the roller surface is hardly worn even after long-term use. The present invention has been completed.

（式中、ｐは繰り返し単位数である）で表されるシリコーンオイルであり、
前記片末端反応性シリコーンオイル類が下記式(IV)：

（式中、Ｒ ³ は、メチル基又はブチル基であり、ｑは繰り返し単位数である）で表されるシリコーンオイル及び／又は下記式(V)：

で表されるシリコーンオイルである
ことを特徴とする。ここで、電子線硬化型樹脂は、電子線により重合可能な樹脂及び／又は化合物を電子線照射により硬化させたものである。また、本発明における樹脂被覆層を形成する非電子線硬化型樹脂及び化合物とは、分子量1,000あたり電子線感受性の高い(メタ)アクリロイル基を0〜0.01未満含有する樹脂及び化合物であり、0に近いほうが好ましい。また、電子線により重合可能な樹脂及び化合物とは、分子量1,000あたり電子線感受性の高い(メタ)アクリロイル基を0.01以上、好適には0.1以上含有する樹脂及びオリゴマー並びに１分子中に１個以上の(メタ)アクリロイル基を有する(メタ)アクリレートである。 That is, the developing roller of the present invention is a developing roller comprising a shaft, an elastic layer formed on the outer periphery of the shaft, and at least one resin coating layer formed on the outer peripheral surface of the elastic layer.
The resin coating layer includes a non-electron beam curable silicon-containing resin and / or compound, an electron beam curable resin, and a carbon-based electronic conductive agent,
The resin coating layer comprises a non-electron beam curable silicon-containing resin and / or compound and a resin and / or compound having a double bond between carbon atoms that can be polymerized by an electron beam and containing silicon. Is applied to the outer peripheral surface of the elastic layer, and then a resin and / or compound having a carbon-carbon double bond polymerizable by the electron beam and containing silicon is cured by electron beam irradiation,
Resins and / or compounds having a carbon-carbon double bond that can be polymerized by an electron beam and containing silicon are reactive silicone oils at both ends, reactive silicone oils at one end, and (meth) acryloxyalkylsilane. At least one selected from the group consisting of
The both-end reactive silicone oils are represented by the following formula (III):

(Wherein p is the number of repeating units),
The one-end reactive silicone oil is represented by the following formula (IV):

(Wherein R ³ is a methyl group or a butyl group, q is the number of repeating units) and / or the following formula (V):

It is the silicone oil represented by these. Here, the electron beam curable resin is obtained by curing a resin and / or compound polymerizable by an electron beam by electron beam irradiation. Further, the non-electron beam curable resin and compound forming the resin coating layer in the present invention are a resin and a compound containing 0 to less than 0.01 (meth) acryloyl group having a high electron beam sensitivity per 1,000 molecular weights. Closer is preferable. Resins and compounds that can be polymerized by an electron beam include resins and oligomers containing (meth) acryloyl groups having a high electron beam sensitivity of 0.01 or more, preferably 0.1 or more per 1,000 molecular weight, and one or more in one molecule. It is a (meth) acrylate having a (meth) acryloyl group.

  In a preferred embodiment of the developing roller of the present invention, the non-electron beam curable silicon-containing resin and / or compound is at least one selected from the group consisting of silicon-containing (meth) acrylate resins and compounds, and silicone resins. It is.

In the developing roller of the present invention, the electron beam-curable resin is a silicon-containing electron beam-curable resin.

In the developing roller of the present invention, the resin coating layer contains a carbon-based electronic conductive agent. Since the electron beam is difficult to be absorbed by the carbon-based electron conductive agent, the remaining amount of the unreacted compound can be sufficiently suppressed even if the carbon-based electron conductive agent is used for adjusting the electric resistance of the resin coating layer.

  In another preferred embodiment of the developing roller of the present invention, the resin coating layer has a thickness of 1 to 500 μm. Since the electron beam reaches the deep part of the resin coating layer, the remaining amount of the unreacted compound can be sufficiently suppressed even if the resin coating layer is thick.

  The image forming apparatus of the present invention includes at least a developing roller, and the developing roller is the developing roller.

  According to the present invention, in the developing roller having a resin coating layer disposed on the surface of the elastic layer, a non-electron beam curable silicon-containing resin and / or compound and an electron beam curable resin are used for the resin coating layer. Therefore, it is possible to provide a developing roller that does not contaminate the photosensitive drum, has a low frictional resistance on the roller surface, is hardly worn even after long-term use, and has excellent durability. Further, it is possible to provide an image forming apparatus including such a developing roller and capable of forming a good image over a long period of time.

  Hereinafter, the developing roller of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an example of the developing roller of the present invention. The developing roller 1 in the illustrated example includes a shaft 2, an elastic layer 3 formed on the outer periphery of the shaft 2, and a resin coating layer 4 formed on the outer peripheral surface of the elastic layer 3. In the drawing, the resin coating layer 4 is composed of one layer, but the resin coating layer 4 of the developing roller of the present invention may be composed of two or more layers.

  In the developing roller 1 of the present invention, since the resin coating layer 4 is formed by electron beam irradiation, it is possible to prevent residual unreacted compounds by optimizing the electron beam irradiation amount. Moreover, the crosslinking density of the resin coating layer 4 can also be adjusted by controlling the acceleration voltage of an electron beam. Furthermore, since the electron beam is difficult to be absorbed by the carbon-based electron conductive agent, even when a carbon-based electron conductive agent is used for the resin coating layer 4, an electron beam curable resin can be sufficiently generated by electron beam irradiation, Unreacted compounds can be prevented from remaining.

  In the developing roller 1 of the present invention, the resin coating layer 4 includes a non-electron beam curable silicon-containing resin and / or compound and an electron beam curable resin, and the non-electron beam curable silicon-containing resin and / or compound. Since the surface energy is small, the frictional resistance of the surface is low, it is difficult to wear even after long-term use, and it has excellent durability. In general, the silicon-containing resin and / or compound has poor compatibility with the elastic layer 3 and is less adhesive than the general resin, but the resin coating layer 4 of the developing roller of the present invention. In this case, since the surface energy of the non-electron beam curable silicon-containing resin and / or compound is smaller than the surface energy of a normal electron beam curable resin, the surface side of the resin coating layer 4 (that is, the elastic layer 3 is not contacted). The non-electron beam curable silicon-containing resin and / or compound tends to be unevenly distributed on the non-electron beam curable silicon side resin, and as a result, the non-electron beam curable silicon-containing resin and / or the resin coating layer 4 on the side in contact with the elastic layer 3 The content rate of a compound falls and the adhesiveness of the resin coating layer 4 and the elastic layer 3 improves. Further, as a result of the non-electron beam curable silicon-containing resin and / or compound being unevenly distributed on the surface side of the resin coating layer 4, the releasability of the resin coating layer 4 from the toner is improved. Furthermore, even if the content of the non-electron beam curable silicon-containing resin and / or compound in the resin coating layer 4 is reduced, the non-electron beam curable silicon-containing resin and / or compound is unevenly distributed on the surface side of the resin coating layer 4. Therefore, the releasability of the resin coating layer 4 from the toner can be sufficiently maintained, and the adhesiveness between the resin coating layer 4 and the elastic layer 3 is improved, and an expensive silicon-containing resin and / or compound is used. It is also possible to reduce the content of.

  The shaft of the developing roller of the present invention is not particularly limited as long as it has good conductivity. For example, a metal core made of a solid metal such as iron, stainless steel, or aluminum, or a metal hollowed inside A metal shaft such as a cylindrical body can be used.

  The elastic layer of the developing roller of the present invention contains an elastomer and a conductive agent, and optionally contains other components such as a filler. Examples of the elastomer used for the elastic layer include silicone rubber, ethylene-propylene-diene rubber (EPDM), acrylonitrile-butadiene rubber (NBR), natural rubber, styrene-butadiene rubber (SBR), butyl rubber, chloroprene rubber, acrylic rubber, and epichloro. Examples include hydrin rubber (ECO), ethylene-vinyl acetate copolymer (EVA), polyurethane, and mixtures thereof. Among these, silicone rubber, EPDM, ECO, and polyurethane are preferable. In the elastic layer, the elastomer may be used as a foam by chemically foaming the elastomer using a foaming agent, or mechanically entraining and foaming air like a polyurethane foam.

  The shaft and the elastic layer may be integrated using a reaction injection molding method (RIM molding method). That is, it is possible to integrate the shaft and the elastic layer by mixing and injecting two kinds of monomer components constituting the raw material component of the elastic layer into a cylindrical mold and performing a polymerization reaction. As a result, the time required from injection of raw materials to demolding can be shortened, and production costs can be greatly reduced.

  When silicone rubber is used for the elastic layer, the silicone rubber may be general millable silicone rubber (HCR) or liquid silicone rubber (LSR). In addition, when using liquid silicone rubber, it is preferable to form an elastic layer by liquid injection molding (LIM: Liquid injection Molding). The above liquid silicone rubber contains vinyl group-containing polyorganosiloxane with organohydrogenpolysiloxane, reinforcing filler such as silica, conductive agent, platinum-based catalyst, reaction inhibitor, silicone oil, and other various additives. After being injected into a mold having a predetermined shape, it is molded by heat curing.

（式中、Ｒ¹は、それぞれ独立して一価の炭化水素基であり、ｎは100〜10,000の整数である）で表される化合物が好ましい。ここで、Ｒ¹における、一価の炭化水素基としては、メチル基、エチル基、プロピル基、ブチル基及びペンチル基等のアルキル基、ビニル基及びアリル基等のアルケニル基、シクロヘキシル基等のシクロアルキル基、フェニル基等のアリール基、ベンジル基等のアラルキル基等が挙げられる。 The vinyl group-containing polyorganosiloxane has two or more reactive groups in the molecule, and examples of the reactive group include an alkenyl group and a hydroxyl group. As the vinyl group-containing polyorganosiloxane, the following formula (I):

In the formula, R ¹ is each independently a monovalent hydrocarbon group, and n is an integer of 100 to 10,000. Here, the monovalent hydrocarbon group in R ¹ includes an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group, an alkenyl group such as a vinyl group and an allyl group, and a cyclohexyl group such as a cyclohexyl group. Examples include alkyl groups, aryl groups such as phenyl groups, and aralkyl groups such as benzyl groups.

（式中、Ｒ²は、それぞれ独立して水素又は一価の炭化水素基であり、ｍは10〜1,000の整数である）で表され、分子中に２個以上のケイ素−水素結合を有する化合物が好ましい。ここで、Ｒ²における、一価の炭化水素基としては、メチル基、エチル基、プロピル基、ブチル基及びペンチル基等のアルキル基、ビニル基及びアリル基等のアルケニル基、シクロヘキシル基等のシクロアルキル基、フェニル基等のアリール基、ベンジル基等のアラルキル基等が挙げられる。 Examples of the organohydrogenpolysiloxane include the following formula (II):

(Wherein R ² is each independently hydrogen or a monovalent hydrocarbon group, m is an integer of 10 to 1,000), and has two or more silicon-hydrogen bonds in the molecule. Compounds are preferred. Here, the monovalent hydrocarbon group in R ² includes alkyl groups such as methyl group, ethyl group, propyl group, butyl group and pentyl group, alkenyl groups such as vinyl group and allyl group, and cyclohexane such as cyclohexyl group. Examples include alkyl groups, aryl groups such as phenyl groups, and aralkyl groups such as benzyl groups.

  In addition, as a conductive agent contained in the liquid silicone rubber, a conductive agent generally used for an elastic layer to be described later can be used. As a platinum-based catalyst, platinous chloride, chloroplatinic acid, alcohol-modified chloroplatinic acid can be used. Examples of the reaction inhibitor include methylvinylcyclotetrasiloxane, acetylene alcohols, siloxane-modified acetylene alcohol, hydroperoxide and the like.

  Examples of the conductive agent used for the elastic layer include an electronic conductive agent and an ionic conductive agent. Electronic conductive agents include conductive carbon such as ketjen black and acetylene black, carbon black for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT and MT, and carbon black for color subjected to oxidation treatment. , Pyrolytic carbon black, natural graphite, artificial graphite, antimony-doped tin oxide, ITO, tin oxide, titanium oxide, zinc oxide and other metal oxides, nickel, copper, silver, germanium and other metals, polyaniline, polypyrrole, polyacetylene, etc. And conductive whiskers such as carbon whisker, graphite whisker, titanium carbide whisker, conductive potassium titanate whisker, conductive barium titanate whisker, conductive titanium oxide whisker, and conductive zinc oxide whisker. The blending amount of the electronic conductive agent is preferably in the range of 1 to 50 parts by mass, more preferably in the range of 5 to 40 parts by mass with respect to 100 parts by mass of the elastomer.

  Examples of the ionic conductive agent include tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, denatured fatty acid dimethylethylammonium, and other perchlorates, chlorates, hydrochlorides, and bromates. Ammonium salts such as salts, iodates, borofluorides, sulfates, ethyl sulfates, carboxylates, sulfonates; alkaline metals such as lithium, sodium, potassium, calcium, magnesium, alkaline earth metals Examples include perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, trifluoromethyl sulfate, and sulfonate. The compounding amount of the ionic conductive agent is preferably in the range of 0.01 to 10 parts by mass, more preferably in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the elastomer. The said electrically conductive agent may be used individually by 1 type, may be used in combination of 2 or more type, and may combine an electronic conductive agent and an ionic conductive agent.

The elastic layer preferably has a resistance value of 10 ³ to 10 ¹⁰ Ωcm, more preferably 10 ⁴ to 10 ⁸ Ωcm, depending on the blending of the conductive agent. If the resistance value of the elastic layer is less than 10 ³ Ωcm, the charge may leak to the photosensitive drum or the like, and the developing roller itself may be damaged by the voltage. If the resistance value exceeds 10 ¹⁰ Ωcm, fogging tends to occur.

  The elastic layer may contain a crosslinking agent such as an organic peroxide and a vulcanizing agent such as sulfur in order to make the elastomer into a rubbery material, if necessary. Accelerators, vulcanization accelerators, vulcanization retarders, and the like may be included. In addition, the elastic layer further comprises a rubber compounding agent such as a filler, a peptizer, a foaming agent, a plasticizer, a softener, a tackifier, an anti-tacking agent, a separating agent, a release agent, a bulking agent, and a coloring agent. An agent may be contained.

  When forming the elastic layer using polyurethane or EPDM as a base material, various charge control agents such as nigrosine, triaminophenylmethane, and cationic dyes, silicone resin, silicone rubber, nylon are used to control the toner charge amount on the surface. A fine powder such as may be added. Here, the addition amount of the charge control agent is preferably in the range of 1 to 5 parts by mass with respect to 100 parts by mass of the polyurethane or EPDM, and the addition amount of the fine powder is relative to 100 parts by mass of the polyurethane or EPDM. A range of 1 to 10 parts by mass is preferred.

  The hardness of the elastic layer is not particularly limited, but is preferably 80 degrees or less in terms of Asker C hardness, and more preferably 20 to 70 degrees. When the Asker C hardness of the elastic layer exceeds 80 degrees, the contact area between the developing roller and the photosensitive drum becomes small, and there is a risk that good development cannot be performed. Toner sticking or 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. Since the elastic layer is used in contact with a photosensitive drum, a stratified blade or the like, even when the hardness is set to a low hardness, it is preferable to make the compression set as small as possible, specifically 20% or less. It is preferable.

  The surface roughness of the elastic layer is not particularly limited, but the JIS 10-point average roughness (Rz) is preferably 30 μm or less, and more preferably 1 to 20 μm. When the surface roughness (Rz) of the elastic layer exceeds 30 μm, the layer thickness of the toner layer and the uniformity of charging may be impaired. By setting the surface roughness to 30 μm or less, toner adhesion can be improved. In addition, it is possible to more reliably prevent image deterioration due to roller wear during long-term use. In order to obtain an appropriate surface roughness, the roller surface may be polished. However, if a polishing step is provided, the productivity of the roller is deteriorated and the manufacturing cost is increased. Therefore, it is preferable that the mold surface for molding the elastic layer is appropriately roughened, and the rough surface of the mold surface is transferred to the surface of the elastic layer to be molded to obtain the above surface roughness.

The resin coating layer of the developing roller of the present invention comprises a non-electron beam curable silicon-containing resin and / or compound, an electron beam curable resin, and a carbon-based electron conductive agent . The resin coating layer comprises a non-electron beam curable silicon-containing resin and / or compound and a coating solution containing a resin and / or compound having a double bond between carbon atoms that can be polymerized by an electron beam and containing silicon. After coating on the outer surface of the elastic layer, it is formed by curing a resin and / or compound having a carbon-carbon double bond that can be polymerized by an electron beam and containing silicon . In general, by providing a resin coating layer on the outer surface of the elastic layer, the resistance value can be adjusted, the toner charge amount and the toner transport amount can be controlled, and the frictional force between the developing roller and the stratified blade can be controlled. However, by including a non-electron beam curable silicon-containing resin and / or compound and an electron beam curable resin in the resin coating layer, the frictional force of the resin coating layer is greatly reduced, and the durability of the developing roller is improved. It can be greatly improved. Here, the coating liquid preferably contains a reactive diluent and a conductive agent, and may contain a known additive as required, and preferably does not contain a solvent. Examples of a method for applying the coating liquid to the surface of the elastic layer include a spray method, a roll coater method, a dipping method, and a die coating method. Moreover, the conditions of electron beam irradiation are suitably selected according to the kind and application amount of electron beam curable resin.

  In the resin coating layer, the ratio of the non-electron beam curable silicon-containing resin and / or compound to the electron beam curable resin is an electron beam curable with respect to a total of 100 parts by mass of the non-electron beam curable silicon-containing resin and compound. The mold resin is preferably in the range of 10 to 10,000 parts by mass, more preferably in the range of 30 to 5000 parts by mass. If the blending amount of the electron beam curable resin is less than 10 parts by mass with respect to 100 parts by mass of the non-electron beam curable silicon-containing resin and the compound, the degree of crosslinking due to electron beam curing may be insufficient, and the coating strength may decrease. If it exceeds 10000 parts by mass, the silicon content will be low, and the intended performance may not be achieved.

  The silicon content in the resin coating layer is preferably in the range of 0.1 to 50% by mass, and more preferably in the range of 0.5 to 30% by mass. If the silicon content in the resin coating layer is less than 0.1% by mass, the properties of silicon may not be sufficiently exhibited and durability may be insufficient. If it exceeds 50% by mass, the adhesion between the coating film and the lower layer is poor. There is a case.

  The non-electron beam curable silicon-containing resin and / or compound used for the resin coating layer is preferably one that is dispersed or dissolved in the coating solution, specifically, a silicon-containing (meth) acrylate-based compound having a plurality of siloxane bonds. Examples thereof include resins and compounds, silicone resins, alkoxysilanes, and polymers thereof. The non-electron beam curable silicon-containing resin and / or compound may be used alone or in combination of two or more. Here, the silicon content of the non-electron beam curable silicon-containing resin and / or compound is preferably in the range of 2 to 70% by mass, and more preferably in the range of 2 to 50% by mass. If the silicon content of the non-electron beam curable silicon-containing resin and / or compound is less than 2% by mass, the silicon content will be low, and the intended performance may not be achieved. This is inappropriate because solubility may decrease and dispersibility may decrease.

  As the non-electron beam curable silicon-containing (meth) acrylate resin, in addition to a homopolymer of silicon-containing (meth) acrylate such as polysiloxane group-containing (meth) acrylate, the silicon-containing (meth) acrylate, Alkyl esters of (meth) acrylic acid such as methyl, ethyl, butyl, octyl, dodecyl; hydroxyalkyl esters such as hydroxyethyl, hydroxybutyl; copolymers with silicon-free (meth) acrylates such as glycidyl ester Can be mentioned. The copolymer further has a (meth) acrylic acid perfluoroalkyl ester and partially fluorinated alkyl ester, and a perfluoroalkyl group or partially fluorinated alkyl group linked via an organic linking group (meth). A small amount of a fluorine-containing (meth) acrylate such as an acrylate ester may be copolymerized. The polysiloxane group-containing (meth) acrylate includes (meth) acrylic acid ester in which a (meth) acryloyl group is linked to one or both ends of the polysiloxane chain via a divalent linking group. Can be mentioned. On the other hand, the silicone resin is, for example, a polymer having a three-dimensional network structure obtained by hydrolyzing and polymerizing organochlorosilanes, and a trifunctional monomer such as methyltrichlorosilane and phenyltrichlorosilane as a main monomer. A bifunctional monomer such as dimethyldichlorosilane and diphenyldichlorosilane and a monofunctional monomer such as chlorosilane are optionally combined. A modified silicone resin obtained by alkyd modification, polyester modification, epoxy modification or phenol modification of the silicone resin can also be used. Further, as the non-electron beam curable silicon-containing resin and / or compound, a silicate that is an alkoxysilane (silicate ester) and a polymer obtained by polymerizing them can also be used. Examples of these silicates include methyl silicate, ethyl Examples thereof include silicate, propyl silicate, and butyl silicate. These non-electron beam curable silicon-containing resins and / or compounds may be used alone or in combination of two or more.

  On the other hand, as the electron beam curable resin used for the resin coating layer, polyester resin, polyether resin, fluorine resin, epoxy resin, amino resin, polyamide resin, acrylic resin, acrylic urethane resin, urethane resin, alkyd resin, phenol resin Melamine resin, urea resin, silicone resin, polyvinyl butyral resin, vinyl ether resin, vinyl ester resin, and modified resins having a specific functional group introduced into these resins. You may mix and use a seed | species or more. Moreover, it is preferable to introduce a crosslinked structure into the resin coating layer in order to improve mechanical strength and environmental resistance.

The electron beam-curable resin is formed by a resin and / or compound is cured by electron beam irradiation comprising a perforated with and silicon double bond polymerizable carbon atoms by an electron beam. The resin and / or compound having a double bond between carbon atoms that can be polymerized by the electron beam and containing silicon may be used alone or in combination of two or more. Good.

  As the resin and / or compound containing silicon having a polymerizable double bond between carbon atoms used for forming the electron beam curable resin, both-end-reactive silicone oils, one-end-reactive silicone oils, (Meth) acryloxyalkylsilanes are preferred. Further, as reactive silicone oils, those having a (meth) acryl group introduced at the terminal are preferable. The silicon content of the silicon-containing resin and / or compound having a polymerizable double bond between carbon atoms is preferably in the range of 0.01 to 40% by mass, more preferably in the range of 0.05 to 35% by mass, and 0.1 to 30%. A mass% range is particularly preferred.

As the both-end reactive silicone oils, silicone oils represented by the above formula (III) are used . Commercially available products can be used as the both-end-reactive silicone oils, for example, “X-22-164A” (viscosity 25 mm ² / s, functional group equivalent 860 g / s) manufactured by Shin-Etsu Chemical Co., Ltd. mol), product name “X-22-164B” (viscosity 55 mm ² / s, functional group equivalent 1630 g / mol), product name “X-22-164C” (viscosity 90 mm ² / s, functional group equivalent 2370 g / mol), Toray・ Product number “BX16-152B” manufactured by Dow Corning Silicone Co., Ltd. (viscosity 40cs / 25 ° C., methacryl group equivalent 1300 g / mol, specific gravity 0.97 at 25 ° C.), product number “BY16-152” (viscosity 85cs / 25 ° C. Methacryl group equivalent 2800 g / mol, specific gravity 0.97 at 25 ° C.), product number “BX2-152C” (viscosity 330 cs / 25 ° C., methacryl group equivalent 5100 g / mol, specific gravity 0.97 at 25 ° C.), etc. can be used.

Further, as the one-end reactive silicone oils, silicone oils represented by the above formula (IV) and / or silicone oils represented by the above formula (V) are used . Commercially available products can be used as the one-terminal reactive silicone oils, for example, “X-24-8201” (viscosity 25 mm ² / s, functional group equivalent 2100 g / s) manufactured by Shin-Etsu Chemical Co., Ltd. mol), product name “X-22-174DX” (viscosity 60 mm ² / s, functional group equivalent 4600 g / mol), product name “X-22-2426” (viscosity 180 mm ² / s, functional group equivalent 12000 g / mol), Toray A product number “BX16-122A” manufactured by Dow Corning Silicone Co., Ltd. (viscosity 5cs / 25 ° C., refractive index 1.417, specific gravity 0.92 at 25 ° C.) or the like can be used.

The (meth) acryloxyalkylsilanes include 3-methacryloxypropyldichloromethylsilane [CH ₂ ═C (CH ₃ ) COO (CH ₂ ) ₃ SiCl ₂ CH ₃ ], 3-acryloxypropyldimethoxymethyl. silane _{[CH 2 = CHCOO (CH 2} ) 3 Si (OCH 3) 2 CH 3], 3- acryloxypropyltrimethoxysilane _{[CH 2 = CHCOO (CH 2} ) 3 Si (OCH 3) 3], 3- methacryl b propyl dimethoxy methyl silane _{[CH 2 = C (CH 3} ) COO (CH 2) 3 Si (OCH 3) 2 CH 3], 3- methacryloxypropyl trimethoxysilane _{[CH 2 = C (CH 3} ) COO (CH _{2) 3 Si (OCH 3)} 3], 3- methacryloxypropyl diethoxymethyl silane _{[CH 2 = C (CH 3} ) COO (CH 2) 3 Si (OC 2 H 5) 2 CH 3], 3- methacrylonitrile Shi propyltriethoxysilane _{[CH 2 = C (CH 3} ) COO (CH 2) 3 Si (OC 2 H 5) 3] , and the like. As the (meth) acryloxyalkylsilanes, commercially available products can be used. For example, product numbers “LS-2080”, “LS-2826”, “LS-2827” manufactured by Shin-Etsu Chemical Co., Ltd., “LS-3375”, “LS-3380”, “LS-4548”, “LS-5118”, and the like can be used.

  Various additives such as a reactive diluent having a polymerizable double bond and a conductive agent may be further blended in the coating liquid used for forming the resin coating layer, if necessary. By blending a reactive diluent having a polymerizable double bond into the coating solution, the viscosity of the coating solution can be adjusted. As the reactive diluent, a monofunctional, bifunctional or polyfunctional polymerizable compound having a structure in which (meth) acrylic acid is bonded to a compound containing an amino acid or a hydroxyl group by an esterification reaction or an amidation reaction is used. be able to. The compounding amount of the reactive diluent is preferably in the range of 10 to 200 parts by mass with respect to a total of 100 parts by mass of the resin and compound polymerizable by the electron beam.

In addition, as the conductive agent used in the coating solution, a carbon-based electronic conductive agent is used. Since the electron beam is not easily absorbed by the carbon-based electron conductive agent, in the present invention, the carbon-based electron conductive agent can also be suitably used for the resin coating layer. Here, as the carbon-based electronic conductive agent, conductive carbon such as ketjen black and acetylene black, carbon black for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT and MT, oxidation treatment, etc. And carbon black for color, pyrolytic carbon black, natural graphite, artificial graphite, carbon whisker, graphite whisker and the like. The blending amount of the electron conductive agent is preferably 100 parts by mass or less, and 1 to 80 parts by mass with respect to 100 parts by mass in total of the non-electron beam curable silicon-containing resin and compound and a resin and compound polymerizable by electron beam. The range of parts is further preferred, and the range of 10 to 50 parts by mass is even more preferred.

  The thickness of the resin coating layer is preferably in the range of 1 to 500 μm, more preferably in the range of 3 to 200 μm, and still more preferably in the range of 5 to 100 μm. If the thickness of the resin coating layer is less than 1 μm, the electrical performance of the developing roller surface may not be sufficiently ensured due to friction during long-term use. If the thickness exceeds 500 μm, the developing roller surface becomes hard and damages the toner. In some cases, the toner adheres to the photosensitive drum or the stratified blade to cause image defects.

The developing roller of the present invention preferably has an electric resistance of 10 ³ to 10 ¹⁰ Ω, more preferably 10 ⁴ to 10 ⁸ Ω. If the resistance value of the developing roller is less than 10 ³ Ω, gradation control is difficult, and if the photosensitive drum or the like is defective, a bias leak may occur. On the other hand, if the resistance value of the developing roller exceeds 10 ¹⁰ Ω, when developing toner on a photosensitive drum, the developing bias causes a voltage drop due to the high resistance of the developing roller itself, and a sufficient developing bias for development can be secured. As a result, sufficient image density cannot be obtained. The resistance value is measured, for example, by pressing the outer peripheral surface of the developing roller against a flat plate or cylindrical counter electrode with a predetermined pressure, applying a voltage of 100 V between the shaft and the counter electrode, and obtaining from the current value at that time. be able to. Note that it is important to appropriately and uniformly control the resistance value of the developing roller in order to keep the electric field strength for moving the toner properly and uniformly.

  The image forming apparatus of the present invention includes the above-described developing roller having a low surface frictional resistance and excellent durability, and can form a good image over a long period of time. The image forming apparatus of the present invention is not particularly limited except that the developing 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. 2 is a partial cross-sectional view of an example of the image forming apparatus of the present invention. The image forming apparatus of the illustrated example includes a toner supply roller 6 for supplying toner 5, a photosensitive drum 7 that holds an electrostatic latent image, and the above-described toner disposed between the toner supply roller 6 and the photosensitive drum 7. The developing roller 1, the stratified blade 8 provided in the vicinity of the developing roller 1 (upper part in the figure), the charging roller 9 located in the vicinity of the photosensitive drum 7 (upper in the figure), and the vicinity of the photosensitive drum 7 (in the figure) A transfer roller 10 located on the lower side and a cleaning unit 11 provided adjacent to the photosensitive drum 7. The image forming apparatus of the present invention can further include a known component (not shown) that is usually used in the image layer forming apparatus.

  In the image forming apparatus of the illustrated example, after the photosensitive drum 7 is charged to a constant potential by the charging roller 9, an electrostatic latent image is formed on the photosensitive drum 7 by an exposure machine (not shown). Next, the toner supply roller 6, the developing roller 1, and the photosensitive drum 7 rotate in the direction of the arrow in the drawing, so that the toner 5 on the toner supply roller 6 is sent to the photosensitive drum 7 through the developing roller 1. It is done. The toner 5 on the developing roller 1 is adjusted to a uniform thin layer by the stratifying blade 8, and the toner 5 is transferred from the developing roller 1 to the photosensitive drum 7 by rotating while the developing roller 1 and the photosensitive drum 7 are in contact with each other. It adheres to the electrostatic latent image and the latent image becomes visible. The toner 5 attached to the latent image is transferred onto a recording medium such as paper by the transfer roller 10, and the toner 5 remaining on the photosensitive drum 7 after the transfer is removed by the cleaning blade 12 of the cleaning unit 11. Here, in the image forming apparatus of the present invention, the developing roller 1 of the present invention having the above-described surface friction resistance is low, is not easily worn even after long-term use, and has excellent durability. It is possible to form a good image over a long period of time. Further, the developing roller 1 does not contaminate the photosensitive drum 7 because the remaining of the unreacted compound in the resin coating layer 4 is sufficiently suppressed.

  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.

(Example 1)
SANNICS FA952 [Sanyo Kasei Kogyo Co., Ltd. polyether polyol, OH value = 37] 100 parts by mass, SRX274C [Toray Dow Corning Silicone Co., Ltd. foam stabilizer] 1 part by mass, TOYOCAT NP [Tosoh Corporation amine catalyst] 2.8 parts by mass, 1.5 parts by mass of TOYOCAT EP [amine catalyst manufactured by Tosoh Corporation] and 59 parts by mass of Sunfoam IC-716 [Sanyo Chemical Co., Ltd. Tolylene Diisocyanate] were mechanically stirred and foamed.

  Next, a metal shaft with an outer diameter of 8.0 mm and a length of 240 mm is arranged from one side opening of a metal cylindrical mold having an inner diameter of 16 mm and a length of 250 mm, and the surface is fluorinated. Was injected from the foaming machine.

  Next, the mold in which the foamed polyurethane raw material was injected was heated in an oven at 80 ° C. for 20 minutes and then removed from the mold, and a roller body having an elastic layer made of urethane foam having an outer diameter of 16 mm and a foam part with an overall length of 230 mm Produced.

  A coating liquid having the composition shown in Table 1 was applied to the outer peripheral surface of the roller body with a roll coater, and while rotating the roller using a Min-EB apparatus manufactured by Ushio Electric Co., Ltd., an acceleration voltage of 30 kV, a tube current of 300 μA, When irradiated with an electron beam under the conditions of an irradiation distance of 100 mm, a nitrogen atmosphere of 760 Torr, and an irradiation time of 1 minute, the coating solution is instantly cured to form an elastic resin coating layer, and the resin coating layer is formed on the outer peripheral surface of the roller body. Thus, a developing roller having was obtained. The toner charge amount and toner transport amount of the obtained developing roller are evaluated by a known method, and the developing roller is incorporated in the image forming apparatus, and the image density, the presence of halftone spots, the presence of fogging, and the density difference between the leading and trailing edges are measured. Evaluated by a known method, and further adhered to the toner on the developing roller surface after printing 10,000 sheets, and incorporated into the developing roller image forming apparatus, and examined image density, presence of halftone spots, presence of fogging, and difference in front and rear end density. . These results are shown in Table 1.

(Example 2)
100 parts by mass of Nipol IR2200L (manufactured by Zeon Corporation) with Mooney viscosity ML _{1 + 4} (100 ° C.) of 70, 60 parts by mass of LIR-30 (manufactured by Kuraray) with an average molecular weight of 29,000, carbon black TB # 5500 (manufactured by Tokai Carbon Co., Ltd.) 28 A rubber composition was prepared by kneading 5 parts by mass, 5 parts by mass of zinc oxide, 1 part by mass of stearic acid, and 9 parts by mass of perhexa C-40 (manufactured by NOF Corporation) using a 55 L kneader. The rubber composition was extruded into a cylindrical shape using a crosshead type extruder manufactured by Mitsuba Manufacturing Co., Ltd., to a cored bar with an outer diameter of φ8 mm to which an adhesive had been attached, to obtain an unvulcanized rubber / cored bar integral molding. This was set in a cylindrical mold, vulcanized at 175 ° C. for 20 minutes under a pressure of 3.2 × 10 ⁶ Pa. The pressure of the split mold was released to obtain a rubber roller, and further vulcanized in an oven at 180 ° C. for 4 hours. The obtained roller was plunge-type polished to a diameter of 16 mm with a rotating grindstone to obtain a rubber roller. A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed on the outer peripheral surface of the roller body using the coating liquid having the composition shown in Table 1. Table 1 shows the physical properties and performance of the obtained developing roller.

Example 3
50 parts by mass of carbon black TB # 5500 (manufactured by Tokai Carbon) with respect to 100 parts by mass of EPDM having an iodine value of 36 and a Mooney viscosity ML _{1 + 4} (100 ° C.) of 39, Nobelite A (manufactured by Nippon Flour Industries) as calcium carbonate 36 parts by weight, 60 parts by weight of Diana Process Oil PW90 (made by Idemitsu Kosan), 3 parts by weight of zinc white, 2 parts by weight of stearic acid, 1 part by weight of vulcanization accelerator 2-mercaptothiazole, 1.5 parts by weight of sulfur, foaming agent Neo Cerbon N 6 parts by mass of # 1000M (manufactured by Eiwa Kasei Kogyo) were kneaded using a 55 L kneader to prepare a foamed rubber composition. The foamed rubber composition was extruded into a cylindrical shape using a cross-head type extruder from Mitsuba Manufacturing Co., Ltd. to a cored bar having an outer diameter of φ8 mm to which an adhesive had been attached, to obtain an unvulcanized rubber / cored bar integrally molded product. This was set in a cylindrical mold, vulcanized and foamed at 175 ° C. for 20 minutes under a pressure of 3.2 × 10 ⁶ Pa. The pressure of the split mold was released to obtain a foamed rubber roller with a skin layer, and further vulcanized in an oven at 180 ° C. for 4 hours. The obtained roller was plunge-type polished to a diameter of φ16 mm with a rotating grindstone to obtain a foamed rubber roller. A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed on the outer peripheral surface of the roller body using the coating liquid having the composition shown in Table 1. Table 1 shows the physical properties and performance of the obtained developing roller.

(Example 4)
Liquid silicone LIM # 2090 (made by Toray Dow Corning Silicone) is stirred and degassed, then poured into a cylindrical mold set with a core metal with an outer diameter of φ8 mm, and hot air is circulated for 30 minutes at 120 ° C. It was heated and cured in an oven. A roller with a cored bar was taken out from the cylindrical mold and cured by heating in a hot air circulation oven at 200 ° C. for 4 hours to obtain a roller. A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed on the outer peripheral surface of the roller body using the coating liquid having the composition shown in Table 1. Table 1 shows the physical properties and performance of the obtained developing roller.

(Example 5)
After adding 1.6 parts by weight of conductive carbon and 0.15 parts by weight of dibutyltin dilaurate to 100 parts by weight of a trifunctional and 9,000 molecular weight polyether polyol obtained by adding propylene oxide to glycerin, sufficiently stirring and mixing, and then stirring for 20 minutes under reduced pressure This was defoamed and used as a polyol component. The hydroxyl value of the polyol component was 19 mgKOH / g. On the other hand, polypropylene glycol-modified polymeric MDI having an NCO content of 11% was degassed as an isocyanate component for 20 minutes while stirring under reduced pressure to obtain an isocyanate component. The polyol component and isocyanate component are mixed at a high speed of 3000 rpm with a two-component casting machine so that the ratio of the polyol component to the isocyanate component is 101.75 / 13.70 (isocyanate index: 103). Was poured into a cylindrical mold set with a core metal of φ8 mm, and heated and cured in a hot air circulation oven at 90 ° C. for 60 minutes. A urethane roller with a cored bar was taken out from the cylindrical mold to obtain a roller. A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed on the outer peripheral surface of the roller body using the coating liquid having the composition shown in Table 1. Table 1 shows the physical properties and performance of the obtained developing roller.

(Example 6)
A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed using the coating liquid having the formulation shown in Table 2. Table 2 shows the physical properties and performance of the obtained developing roller.

(Example 7)
A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed using the coating liquid having the formulation shown in Table 2. Table 2 shows the physical properties and performance of the obtained developing roller.

(Example 8)
100 parts by mass of UR8401 (manufactured by Toyobo), 5 parts by mass of coronate HX (manufactured by Nippon Polyurethane), 25 parts by mass of carbon black Printex 35 (manufactured by Degussa) on the roller body provided with the elastic layer made of the urethane foam produced in Example 1. A coating consisting of 100 parts by mass of MEK (methyl ethyl ketone) was applied to a thickness of 50 μm and then cured by heating at 100 ° C. for 1 hour. A developing roller was manufactured by forming a resin coating layer on the obtained roller using a coating liquid having the formulation shown in Table 2. Table 2 shows the physical properties and performance of the obtained developing roller.

(Comparative Example 1)
A developing roller was produced in the same manner as in Example 1 except that the resin coating layer was formed using the coating liquid having the formulation shown in Table 2. Table 2 shows the physical properties and performance of the obtained developing roller.

(Comparative Example 2)
A developing roller was produced in the same manner as in Example 2 except that the resin coating layer was formed using the coating liquid having the formulation shown in Table 2. Table 2 shows the physical properties and performance of the obtained developing roller.

Evaluation methods:
(1) Image evaluation Image forming device: Commercially available laser printer Cartridge color: Cyan (2) Surface roughness Surfcom 590A (manufactured by Tokyo Seimitsu)
(3) Resistance value
R8340A ULTRA HIGH RESISTANCE METER (manufactured by ADVANTEST)
Measurement conditions: 100V applied voltage between shaft and roller surface
Measured in a static state with a load of 500g on both ends of the roller

  As is apparent from Tables 1 and 2, since the developing roller of the example has a low frictional resistance of the resin coating layer, the surface of the developing roller is worn even if the image forming apparatus incorporating the developing roller is used for a long time. It was difficult to obtain a good image over a long period of time. Further, in the developing roller of the example, the remaining amount of the unreacted compound in the resin coating layer was sufficiently suppressed, so that the photosensitive drum was not contaminated.

It is sectional drawing of an example of the developing roller of this invention. 1 is a partial cross-sectional view of an example of an image forming apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Developing roller 2 Shaft 3 Elastic layer 4 Resin coating layer 5 Toner 6 Toner supply roller 7 Photosensitive drum 8 Layering blade 9 Charging roller 10 Transfer roller 11 Cleaning part 12 Cleaning blade

Claims (5)

In a developing roller comprising a shaft, an elastic layer formed on the outer periphery of the shaft, and at least one resin coating layer formed on the outer peripheral surface of the elastic layer,
The resin coating layer includes a non-electron beam curable silicon-containing resin and / or compound, an electron beam curable resin, and a carbon-based electronic conductive agent,
The resin coating layer comprises a non-electron beam curable silicon-containing resin and / or compound and a resin and / or compound having a double bond between carbon atoms that can be polymerized by an electron beam and containing silicon. Is applied to the outer peripheral surface of the elastic layer, and then a resin and / or compound having a carbon-carbon double bond polymerizable by the electron beam and containing silicon is cured by electron beam irradiation,
Resins and / or compounds having a carbon-carbon double bond that can be polymerized by an electron beam and containing silicon are reactive silicone oils at both ends, reactive silicone oils at one end, and (meth) acryloxyalkylsilane. At least one selected from the group consisting of
The both-end reactive silicone oils are represented by the following formula (III):

(Wherein p is the number of repeating units),
The one-end reactive silicone oil is represented by the following formula (IV):

(Wherein R ³ is a methyl group or a butyl group, q is the number of repeating units) and / or the following formula (V):

A developing roller characterized by being a silicone oil represented by   The non-electron beam curable silicon-containing resin and / or compound is at least one selected from the group consisting of silicon-containing (meth) acrylate resins and compounds, and silicone resins. The developing roller as described.   The developing roller according to claim 1, wherein the electron beam curable resin is a silicon-containing electron beam curable resin.   The developing roller according to claim 1, wherein the resin coating layer has a thickness of 1 to 500 μm. An image forming apparatus comprising the developing roller according to claim 1 .

Images