JP2011197660A - Endless belt for electrophotographic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endless belt for an electrophotographic equipment outstanding in surface smoothness.SOLUTION: The endless belt for electrophotography with an elastic layer provided on a surface of a base layer has the elastic layer formed of a liquid material for an elastic layer made by blending a rubber material, a bridging agent and an inorganic filler with an average particulate diameter of 7 μm or less to a solvent with a boiling point from 150 to 220°. The elastic layer is formed by using the inorganic filler blended at a ratio of 30 to 150 parts by weight to 100 parts by weight of the rubber material.

Description

  The present invention relates to an endless belt for electrophotographic equipment, and particularly suitable as an intermediate transfer belt or the like in electrophotographic equipment using electrophotographic technology such as full color LBP (laser beam printer) and full color PPC (plain paper copier). The present invention relates to an endless belt for electrophotographic equipment that can be used.

  Conventionally, in an electrophotographic apparatus using electrophotographic technology such as full color LBP and full color PPC, an endless belt having a conductivity (seamless belt) has been used for various purposes. For example, for an electrophotographic apparatus that plays a role of primarily transferring a toner image formed on a photoconductor (photosensitive drum) onto a belt surface, and then secondarily transferring the toner image on the belt surface onto a printed material (paper). As an endless belt, an intermediate transfer belt is widely known.

  For such an intermediate transfer belt, in addition to excellent toner transferability, toner adhesion resistance (the toner hardly remains on the belt surface) is required. Along with the demand, the intermediate transfer belt is also required to have better toner transfer and toner adhesion resistance than ever before. Under such circumstances, various types of intermediate transfer belts having a low roughness, that is, a smooth surface, a manufacturing apparatus, a manufacturing method, and the like have been proposed.

  For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-341485) proposes a seamless belt manufacturing apparatus that uses a metal cylindrical body having a mirror-finished inner surface as a mold. Japanese Laid-Open Patent Publication No. 2004-90404) proposes a method of manufacturing a semiconductive belt according to a so-called centrifugal molding method using a cylindrical mold whose inner surface is a mirror surface.

  However, in the method using a mold having a mirror finish on the inner surface as proposed in Patent Documents 1 and 2, a fine but small toner-sized polishing mark is generated on the surface of the obtained belt. In addition, there is a problem that unevenness due to fine cracks or pinholes in the plating applied to the inner surface of the mold may occur.

  On the other hand, in Patent Document 3 (Japanese Patent Laid-Open No. 2006-285048), a two-layer structure of a base layer and a surface print layer is used, and the surface print layer is made of a liquid silicone rubber in which conductive carbon black is dispersed. An intermediate transfer member made of a cured product that has been applied to the surface of a base layer and cured has been proposed.

  However, the inventors of the present invention have diligently studied the intermediate transfer member proposed in Patent Document 3, and the surface printing layer material (liquid silicone rubber in which conductive carbon black is dispersed) shown therein is shown. Instead, it was found that the surface smoothness of the resulting belt is not sufficient when a liquid material obtained by blending a rubber material other than liquid silicone rubber in a solvent is used. That is, when a liquid material obtained by blending a rubber material with a solvent is used, the removal of the solvent proceeds together with the crosslinking of the liquid material (crosslinking of the rubber material), but the removal of the solvent proceeds smoothly. As a result, it has been found that air bubbles are generated in the resulting crosslinked product, which may deteriorate the surface smoothness of the belt.

JP 2006-341485 A JP 2004-90404 A JP 2006-285048 A

  Here, the present invention has been made in the background of such circumstances, and a problem to be solved is to provide an endless belt for electrophotographic equipment having excellent surface smoothness.

  In order to advantageously solve such a problem, the present invention provides an endless belt for an electrophotographic apparatus in which an elastic layer is provided on the surface of a base layer, and the elastic layer has a boiling point of 150 to 220 ° C. A rubber material, a crosslinking agent, and an inorganic filler having an average particle size of 7 μm or less are blended in a solvent, and the elastic filler is formed using a liquid elastic layer material. The gist thereof is an endless belt for electrophotographic equipment which is blended in a proportion of 30 to 150 parts by weight with respect to parts by weight.

  In the first preferred embodiment of the endless belt for electrophotographic equipment according to the present invention, the elastic layer has a thickness of 10 to 1000 μm.

  In the second preferred embodiment of the endless belt for electrophotographic equipment according to the present invention, the crosslinking agent is a metal oxide, sulfur or a resin crosslinking agent.

  Furthermore, in a third preferred embodiment of the endless belt for electrophotographic equipment of the present invention, the inorganic filler is silica or an inorganic flame retardant.

  In addition, in the fourth preferred embodiment of the present invention, an organic flame retardant is blended in the elastic layer material.

  In the fifth preferred embodiment of the present invention, the elastic layer is formed according to a dispenser coating method.

  Furthermore, in a preferred sixth aspect of the present invention, the rubber material is CR, NBR or EPDM.

  Furthermore, in a preferred seventh aspect of the present invention, the base layer is formed according to a dispenser coating method using a liquid base layer material mainly composed of a synthetic resin material. Further, the synthetic resin material is more preferably a polyimide resin or a polyamideimide resin.

On the other hand, in the elastic layer of each aspect described above, the present invention includes one or more selected from the group consisting of a chlorine compound represented by the following general formula (I) and a compound having a —CONCl— structure in the molecule. The gist of the endless belt for electrophotographic equipment is characterized in that surface treatment is performed using BF ₃ .
X (OCl) _n (I)
[In the above formula (I), X represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or an alkyl group, and n represents a positive integer. ]

  The gist of the present invention is also an endless belt for electrophotographic equipment in which a surface layer made of an acrylic fluororesin is provided on the surface of the elastic layer of each aspect described above.

  As described above, in the endless belt for electrophotographic equipment according to the present invention, the elastic layer provided on the surface of the base layer contains a rubber material, a crosslinking agent, and an average particle diameter in a solvent having a boiling point of 150 to 220 ° C. Is a liquid elastic layer material in which an inorganic filler of 7 μm or less is blended, wherein the inorganic filler is blended in a proportion of 30 to 150 parts by weight with respect to 100 parts by weight of the rubber material, Is formed. By preparing the elastic layer material using a solvent having a boiling point within a predetermined range, the removal of the solvent (desolvation) proceeds after the crosslinking has progressed to some extent in the elastic layer material. In addition, by blending an inorganic filler having a predetermined average particle diameter in the elastic layer material at a predetermined ratio, a gap that serves as a solvent escape path can be effectively formed in the (semi) crosslinked product. Generation of bubbles (embedding of bubbles) in the elastic layer as a cross-linked product is advantageously suppressed, so that the endless belt for electrophotographic equipment of the present invention has excellent surface smoothness.

  As described above, the endless belt for electrophotographic equipment according to the present invention is excellent in surface smoothness and exhibits excellent toner transferability when used as an intermediate transfer belt in electrophotographic equipment. For example, a high-quality image can be advantageously obtained when an image is formed on a substrate having relatively unevenness such as recycled paper by being incorporated in an electrophotographic apparatus as an intermediate transfer belt.

It is a section explanatory view showing an example of an endless belt for electrophotographic equipment according to the present invention. It is a fragmentary sectional view showing an example of an endless belt for electrophotographic equipment according to the present invention.

  Hereinafter, the present invention will be described more specifically with reference to the drawings as appropriate.

  FIG. 1 is an explanatory cross-sectional view of an example of an endless belt for electrophotographic equipment (hereinafter also simply referred to as a belt) according to the present invention, cut along a plane parallel to the axial direction of the belt and including the axial center. These are the partial explanatory drawings of the cross section cut | disconnected by the surface (AA surface in FIG. 1) orthogonal to the axial direction of a belt. As is clear from FIGS. 1 and 2, the endless belt 2 for electrophotographic equipment of the present invention has a two-layer structure in which an elastic layer 6 is provided on the surface of a base layer 4.

  First, the base layer 4 is formed according to various conventionally known methods using a base layer material mainly composed of a rubber material or a synthetic resin material. As the rubber material and the synthetic resin material which are the main components of the base layer material, any material can be used as long as it is conventionally used in the production of an endless belt for electrophotographic equipment. From the viewpoint of durability of 2, a synthetic resin material is advantageously used. Examples of synthetic resin materials include polyimide resins, polyamideimide resins, polyethersulfone resins, fluorine resins, polycarbonate resins, and the like, and these can be used alone or in combination of two or more. is there. In the present invention, a polyimide resin and a polyamideimide resin exhibiting excellent rigidity and the like are particularly advantageously used.

  In addition to the rubber material and / or the synthetic resin material as described above, the base layer material may include additives such as a conductive agent, a flame retardant, a filler such as calcium carbonate, and a leveling agent. As long as the purpose is not impaired, it is blended appropriately.

The conductive agent blended in the base layer material is not particularly limited. For example, conductive powder such as carbon black and graphite, metal powder such as aluminum powder and stainless powder, conductive zinc oxide (c-ZnO) , Conductive titanium oxide (c-TiO ₂ ), conductive iron oxide (c-Fe ₃ O ₄ ), conductive tin oxide (c-SnO ₂ ) and other conductive metal oxides, quaternary ammonium salts, phosphorus It is possible to use ionic conductive agents such as acid esters, sulfonates, aliphatic polyhydric alcohols and aliphatic alcohol sulfate salts. Moreover, as a flame retardant mix | blended with the material for base layers, the inorganic flame retardant mentioned later, an organic flame retardant, etc. can be illustrated.

  Preparation of the base layer material formed by blending the above-described synthetic resin material and the like is performed according to the manufacturing method of the belt 2. For example, when the base layer 4 is formed according to the dispenser coating method described later, the above-described synthetic resin material is made of N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), toluene, A liquid base layer material is prepared by adding to and mixing with an organic solvent such as acetone. In addition, when forming the base layer 4 according to the dispenser coating method using such a liquid base layer material, the viscosity of the material is usually adjusted to 1000 to 50000 mPa · s.

  Further, the thickness of the base layer 4 formed using such a base layer material is appropriately determined according to the characteristics required for the endless belt 2 for electrophotographic equipment, but is usually about 50 to 200 μm. The

  And in the endless belt 2 for electrophotographic equipment shown in FIG.1 and FIG.2, the elastic layer 6 is a solvent whose boiling point is 150-220 degreeC, rubber material, a crosslinking agent, and an average particle diameter are 7 micrometers. It is formed using a liquid elastic layer material in which the following inorganic filler is blended, in which the inorganic filler is blended in a proportion of 30 to 150 parts by weight with respect to 100 parts by weight of the rubber material. However, there is a big feature. That is, by using such a liquid elastic layer material, generation of bubbles (embedding of bubbles) in the elastic layer as a crosslinked product is advantageously suppressed, and the surface of the elastic layer 6 (the surface of the belt 2) is smooth. Is an excellent one.

  Here, in a solvent having a boiling point of less than 150 ° C., most of the solvent is removed before the crosslinking proceeds, but the solvent remaining in the crosslinked product (elastic layer) is vaporized in the process of crosslinking. As a result, bubbles may be generated in the crosslinked product, and the smoothness of the elastic layer surface (belt surface) may be deteriorated. On the other hand, a solvent having a boiling point exceeding 220 ° C. is not practical because it takes time to remove the solvent. For this reason, in this invention, the solvent whose boiling point is 150-220 degreeC, Preferably it is 155-215 degreeC is used in the preparation of the elastic layer material. Specific examples of the solvent used for preparing the elastic layer material of the present invention include anone (cyclohexanone), Solvesso # 150 (heavy aromatic (HA-150)), methoxybutyl acetate (3-methoxybutyl acetate), An example is isophorone (3,5,5-trimethyl-2-cyclohexen-1-one).

  The inorganic filler blended in the elastic layer material of the present invention has an average particle size of 7 μm or less, preferably 0.5 to 4.0 μm. This is because if an inorganic filler having an average particle size that is too large is blended, the smoothness of the surface of the resulting elastic layer 6 (the surface of the belt 2) may be impaired. In addition, the average particle diameter of the inorganic filler in the present specification and claims refers to wet measurement using pure water using a fineness distribution measuring device (trade name: Microtrack MT3000, manufactured by Nikkiso Co., Ltd.). Means what is measured.

  Furthermore, if the blending amount of the inorganic filler in the elastic layer material is too small, the blending effect (inhibition of entrainment of bubbles) may not be obtained. On the other hand, if the blending amount is too large, the elastic layer becomes hard. Too much may adversely affect the image. Therefore, in the elastic layer material of the present invention, the inorganic filler is blended in a proportion of 30 to 150 parts by weight, preferably 50 to 120 parts by weight, with respect to 100 parts by weight of the rubber material described later.

  In the present invention, any inorganic powder can be blended with a rubber material or a resin material for the purpose of improving physical properties, increasing the volume, etc., as long as it does not impair the purpose of the present invention. It is possible to mix | blend as a filler. Examples of such inorganic fillers include silica (silicon oxide), titanium oxide, zinc oxide, talc, various ceramics, glass beads, mica (mica), and other inorganic flame retardants, specifically, antimony trioxide, Examples thereof include antimony flame retardants such as antimony pentoxide, metal hydroxide flame retardants such as aluminum hydroxide and magnesium hydroxide, and the like. One or two or more of such inorganic fillers are appropriately selected and blended in the elastic layer material. In the present invention, silica and inorganic flame retardant are particularly advantageously used.

  A rubber material and a crosslinking agent are blended in the elastic layer material of the present invention together with the solvent and the inorganic filler described above.

  The rubber material is appropriately selected from conventionally known various rubber materials according to the characteristics of the target endless belt (2) for electrophotographic equipment, the kind of the crosslinking agent, and the like. Specific examples include chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene-diene rubber (EPDM), butadiene rubber (BR), styrene-butadiene rubber (SBR), and the like. One or two or more of them are appropriately selected and used. Among them, especially chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR) and ethylene-propylene-diene rubber (EPDM) are crosslinked products (elastic layers) obtained even when a relatively large amount of the above-mentioned inorganic filler is blended. ) Is less advantageous in physical properties (especially flexibility), and it is possible to achieve both excellent surface smoothness and flexibility.

  Moreover, as a crosslinking agent mix | blended with the material for elastic layers of this invention, it is possible to use metal oxides, such as zinc white (zinc oxide) and magnesium oxide, various sulfurs, a resin crosslinking agent, etc. Examples of sulfurs include sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur, and sulfur halides such as sulfur monochloride and sulfur dichloride. Examples of the resin cross-linking agent include phenol resin, epoxy resin, amino resin, guanamine resin, unsaturated polyester resin, diallyl phthalate resin, phenoxy resin, and urethane resin. In the present invention, a metal oxide, sulfur, or a resin cross-linking agent is particularly preferably used from the viewpoint of more effectively suppressing the generation of bubbles (embedding of bubbles) in the elastic layer as a cross-linked product.

  In addition, as a phenol resin used as a resin crosslinking agent, a novolak type phenol resin, a resol type phenol resin, a resol type xylene resin, etc. can be illustrated.

  Epoxy resins used as resin crosslinking agents include bisphenol A glycidyl ether, bisphenol glycidyl ether, novolac glycidyl ether, polyethylene glycol glycidyl ether, polypropylene glycol glycidyl ether, glycerin glycidyl ether. And various epoxy resins such as glycidyl ether, aromatic glycidyl ether, aromatic glycidyl amine, phenol glycidyl amine, hydrophthalic acid glycidyl ester, and dimer acid glycidyl ester.

  Furthermore, the amine resin is a general term for thermosetting resins obtained by addition-condensation of formaldehyde with a compound having an amino group such as urea (urea), melamine, benzoguanamine, and aniline. In the present invention, examples of the amine resin used as the resin crosslinking agent include urea resin, melamine resin, methylol melamine resin, benzoguanamine resin, aniline resin, acetoguanamine resin, formguanamine resin, and methylol guanamine resin. .

  In the elastic layer material of the present invention, in addition to the rubber material and the crosslinking agent described above, various additives can be blended in proportions depending on the purpose of each addition.

  For example, in order to impart conductivity to the endless belt 2 for electrophotographic equipment, a conductive agent is generally blended in the elastic layer material. Such conductive agents include not only carbon black and metal oxides that have been widely used in the past, but also quaternary ammonium salts, phosphate esters, sulfonates, aliphatic polyhydric alcohols, aliphatic alcohol sulfate salts, and the like. An ionic conductive agent etc. can be mentioned, and especially an ionic conductive agent is used advantageously.

  In addition, recently, since flame resistance is also required for an endless belt for electrophotographic equipment, it is preferable to add an organic flame retardant to the elastic layer material. Examples of the organic flame retardant used in the present invention include a) decabromodiphenyl ether, b) tetrabromobisphenol-A and derivatives thereof, c) polybenzene ring compounds such as bis (pentabromophenyl) ethane, d) bromine. Brominated flame retardants such as fluorinated polystyrene and polybrominated styrene, e) aromatic phosphoric esters, f) aromatic condensed phosphoric esters, g) halogen-containing phosphoric esters, h) halogen-containing condensed phosphoric acids Examples include esters, i) phosphorus-based flame retardants such as phosphazene derivatives, and the like. These organic flame retardants can be used alone or in combination of two or more, and can also be used in combination with the inorganic flame retardant as the inorganic filler described above.

  In addition, it is also possible to add additives such as a leveling agent and a crosslinking accelerator to the elastic layer material within the scope of the present invention. Examples of the crosslinking accelerator used in the present invention include N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, Sulfenamide-based crosslinking accelerators such as N-oxyethylene-2-benzothiazole sulfenamide and N, N′-diisopropyl-2-benzothiazole sulfenamide; diphenylguanidine, diortolylguanidine, orthotolylbiguanidine, etc. Guanidine-based cross-linking accelerators; thiourea-based cross-linking accelerators such as thiocarboanilide, diortolylthiourea, ethylenethiourea, diethylthiourea, and trimethylthiourea; 2-mercaptobenzothiazole, dibenzothiazyl disulfide, 2 Thiazole-based cross-linking accelerators such as mercaptobenzothiazole zinc salt, 2-mercaptobenzothiazole sodium salt, 2-mercaptobenzothiazolecyclohexylamine salt, 2- (2,4-dinitrophenylthio) benzothiazole; tetramethylthiuram monosulfide, Thiuram-based crosslinking accelerators such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide; sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium di-n-butyldithiocarbamate, dimethyldithiocarbamic acid Lead, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, di-n-butyldithiocarbamate , Zinc pentamethylenedithiocarbamate, zinc ethylphenyldithiocarbamate, tellurium diethyldithiocarbamate, selenium dimethyldithiocarbamate, selenium diethyldithiocarbamate, dimethyldithiocarbamate, iron dimethyldithiocarbamate, diethyldithiocarbamate diethylamine, pentamethylenedithiocarbamate piperidine, methyl Examples include dithiocarbamic acid crosslinking accelerators such as pipemethylene dithiocarbamate pipecoline; xanthogenic crosslinking accelerators such as sodium isopropylxanthate, zinc isopropylxanthate, and zinc butylxanthate.

  In addition, preparation of the material for elastic layers using each component mentioned above mix | blends rubber material, a crosslinking agent, etc. in a predetermined ratio with respect to the solvent whose boiling point is 150-220 degreeC, respectively, and mixes and disperses It is done by damaging. When the elastic layer 6 is formed according to the dispenser coating method using the liquid elastic layer material thus obtained, it is usually prepared so that the viscosity of the material is 1000 to 70000 mPa · s. Is done.

  Further, the thickness of the elastic layer formed using such an elastic layer material is preferably 10 to 1000 μm. If the thickness is less than 10 μm, the belt surface deformation area decreases, so that the belt surface followability to uneven paper deteriorates and toner transferability deteriorates. If the thickness exceeds 1000 μm, the belt is set in the unit by its own weight. This is because sagging occurs at this time, and belt running becomes unstable, causing toner spillage and image disturbance.

  By the way, the base layer 4 and the elastic layer 6 constituting the endless belt 2 for an electrophotographic apparatus of the present invention can each be produced according to various conventionally known methods. In the present invention, the dispenser described below is used. The base layer 4 and the elastic layer 6 are preferably produced according to the coating method. Hereinafter, the case where the endless belt 2 for electrophotographic equipment of the present invention is manufactured according to the dispenser coating method will be described in detail.

  First, it has a cylindrical or columnar base body that can rotate around its axis, two nozzles (first nozzle, second nozzle), and two material tanks (first material tank, second material tank). Prepare the dispenser. The two nozzles (the first nozzle and the second nozzle) are arranged so as to be movable along the axial direction of the base at a position close to the outer peripheral surface of the base. Meanwhile, a liquid base layer material and a liquid elastic layer material are prepared, and the base layer material is accommodated in the first material tank and the elastic layer material is accommodated in the second material tank. The outer diameter of the substrate is determined according to the specifications of the endless belt 2 for electrophotographic equipment finally obtained, and is usually 30 to 350 mm. A nozzle having a nozzle diameter of 0.5 to 2.0 mm is generally used.

  Next, as in the method described in, for example, Japanese Patent No. 3855896 (FIG. 2 and the like), the cylindrical substrate is rotated around the axis in a vertical state. With the substrate rotated, the built-in substrate material is sent from the first material tank containing the substrate material to the first nozzle, and the substrate material from the first nozzle to the outer peripheral surface of the substrate. To discharge. Simultaneously with the discharge of the base layer material, the first nozzle is moved at a constant speed along the axial direction of the substrate. As a result, a band (coating film) having a constant width made of the base layer material is formed in a spiral shape on the outer peripheral surface of the base, and the first nozzle is moved from one end side of the base to the other end. By moving it to the side, an entire coating film consisting of a continuous spiral coating film of the base layer material is formed on the outer peripheral surface of the substrate. The helical coating film of the base layer material is usually formed on the outer peripheral surface of the substrate so that a predetermined interval is generated between the upper band and the lower band.

  The base layer is first formed by subjecting the entire coating film made of the base layer material thus formed on the outer peripheral surface of the substrate to a heat treatment under a predetermined condition and removing the solvent.

  Thereafter, the substrate having the base layer formed on the outer peripheral surface is rotated about the axis in the same manner as described above. A second material tank in which the elastic layer material is housed is moved from the second material tank in which the elastic layer material is accommodated to the outer peripheral surface of the substrate (surface of the formed base layer) in a state where the substrate is rotated about the axis. The elastic layer material is discharged from the second nozzle to the base layer on the outer peripheral surface of the substrate. Simultaneously with the ejection of the elastic layer material, the second nozzle is moved at a constant speed along the axial direction of the substrate. As a result, a band (coating film) of a certain width made of the elastic layer material is formed in a spiral shape on the surface of the base layer formed on the outer peripheral surface of the base, and the second nozzle is connected to one end of the base. By moving from the part side to the other end part side, the entire coating film consisting of a continuous spiral coating film of the elastic layer material is formed on the surface of the base layer on the outer peripheral surface of the substrate. . In the present invention, if the elastic layer is too thin, there is a possibility that the effect (ensurement of the flexibility of the belt surface) by providing the elastic layer cannot be enjoyed advantageously. On the other hand, if the elastic layer is too thick, Since the heat treatment takes time, it is not practical, and there is a possibility that a portion where crosslinking and desolvation occur at the same time in the layer, and bubbles are generated to deteriorate the surface smoothness. For this reason, in this invention, it is preferable that the whole coating film which consists of material for elastic layers is formed so that an elastic layer with a thickness of 10-1000 micrometers can be obtained.

  And the electrophotographic apparatus by which the elastic layer 6 is provided in the surface of the base layer 4 by performing the heat processing according to the rubber material which comprises the material for elastic layers, and a crosslinking agent with respect to the obtained whole coating film The endless belt 2 for use is obtained. Examples of the heat treatment include the following heating methods. 1) First, based on the blending of the elastic layer forming material (particularly the type and blending ratio of the rubber material and the crosslinking agent), a predetermined temperature: X ° C. is set, and the boiling point of the solvent constituting the elastic layer forming material is not less than Temperature: YC is set (X <Y). 2) The entire coating film formed on the surface of the base layer 4 is heated to a temperature: X ° C. and held at a temperature: X ° C. for a predetermined time, and then the entire coating film is further heated to a temperature: Y ° C. for a predetermined time. Temperature: A method of completing the cross-linking of the elastic layer forming material by maintaining the temperature at Y ° C.

  Various conditions for producing the base layer 4 and the elastic layer 6 according to the dispenser coating method as described above, specifically, the rotation speed of the substrate, the moving speed of the nozzle, the discharge amount of each material, etc. Conditions according to the material for use and the material for the elastic layer are appropriately selected and adopted.

  In the method described above, a solid columnar substrate can be used instead of the cylindrical substrate, but the cylindrical substrate is advantageously used from the viewpoint of reducing the burden on the rotating part. It is done. Specifically, a metal drum such as iron, aluminum, and stainless steel can be suitably used.

  Furthermore, as a nozzle for discharging a liquid material (base layer material, elastic layer material), a needle nozzle or the like is used, and a discharge portion shape such as a round shape, a flat shape, or a rectangular shape is used. I can do it.

  In the endless belt 2 for electrophotographic equipment thus obtained, the generation of bubbles (embedding of bubbles) in the elastic layer 6 is advantageously suppressed, and the surface of the elastic layer 6 (the surface of the belt 2). ) Is excellent in smoothness.

  By the way, in the present invention, a belt having a two-layer structure comprising the base layer 4 and the elastic layer 6 obtained as described above for the purpose of exhibiting excellent toner adhesion resistance when used as an intermediate transfer belt. The surface (the surface of the elastic layer 6) can be subjected to a predetermined surface treatment, or a surface layer as a protective layer can be further provided. Hereinafter, the surface treatment of the elastic layer and the formation of the surface layer will be described.

A. In the present invention, when the surface treatment of the elastic layer is performed, (α) a chlorine compound represented by the following general formula (I), (β) a chlorine compound having a —CONCl— structure in the molecule, And BF ₃ is advantageously used.
X (OCl) _n (I)
[In the above formula (I), X represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or an alkyl group, and n represents a positive integer. ]

  Specifically, (α) in the chlorine compound represented by the above general formula (I), the alkali metal atom includes each atom such as lithium, sodium and potassium, and the alkaline earth metal atom includes magnesium and Examples of each atom such as calcium, and an alkyl group further include a methyl group, an ethyl group, a tertiary butyl group, and a trifluoromethyl group.

  Specific examples of the compound represented by the general formula (I) include alkyl hypochlorides such as methyl hypochloride, ethyl hypochloride, tertiary butyl hypochloride, trifluoromethyl hypochloride, and methyl hypofluoride. Alkyl hypohalides such as ethyl hypofluoride, tertiary butyl hypofluoride, alkyl hypofluoride such as trifluoromethyl hypofluoride, hypochlorous acid, lithium hypochlorite, hypochlorous acid, etc. Examples thereof include hypochlorite salts such as sodium oxide, magnesium hypochlorite, and potassium hypochlorite. Two or more of these can be used in combination.

  Specific examples of the chlorine compound having a -CONCl- structure in the molecule include acid imide halogen compounds such as N-chlorosuccinimide and N-chlorophthalimide, and isocyanuric acids such as trichloroisocyanuric acid and dichloroisocyanuric acid. Examples include halides, halogenated hydantoins such as dichlorodimethylhydantoin, and the like. Even in these cases, two or more types can be used in combination.

In the present invention, for the elastic layer before the surface treatment, 1) one or two or more selected from the group consisting of the compounds (α) and (β) are used, or 2) the compound (α ) And (β), and the surface treatment is preferably performed using one or more selected from the group consisting of (β) and BF ₃ . Such surface treatment is carried out by bringing these compounds into contact with the elastic layer before treatment. Preferably, the compound to be brought into contact is dissolved or dispersed in water or a predetermined organic solvent. It is desirable to carry out by preparing a treatment liquid to be brought into contact with the surface of the elastic layer.

  In addition, as a solvent used for preparation of the treatment liquid, water, toluene, acetone, methyl ethyl ketone, tetrahydrofuran, ethyl acetate, butyl acetate, hexane, methanol, ethanol, propanol, tertiary butanol, isopropyl alcohol, diethyl ether, N -Methyl-2-pyrrolidone and the like can be exemplified. The content of the compound in the treatment liquid is not particularly limited as long as the belt surface can be sufficiently treated over the entire surface, but generally the concentration of each compound is 0.01. The treatment liquid is prepared so as to be about ˜40% by weight. By using the treatment liquid prepared to such a concentration, the surface of the elastic layer after the surface treatment is improved in toner adhesion resistance while maintaining an appropriate hardness.

When surface treatment is carried out using one or more selected from the group consisting of the above compounds (α) and (β) and BF ₃ , one obtained by mixing them in a predetermined solvent Even in the case of treatment liquids, or in the case where two or more treatment liquids are prepared by individually mixing them in a predetermined solvent, they can be used in the present invention. In the case where one treatment liquid is prepared by mixing one or two or more selected from the group consisting of the compound (α) and the compound (β) and BF ₃ in a predetermined solvent as described above. The weight ratio of one or two or more compounds selected from the group consisting of the compound (α) and the compound (β) (herein collectively referred to as X) and BF ₃ is appropriately determined, but is preferably within a range. X: BF ₃ = 1: 99 to 90:10 (weight ratio) can be exemplified. This is because within these ranges, the balance between the reactivity to the crosslinked rubber constituting the elastic layer and the effect of introducing fluorine atoms by BF _{3 on the} elastic layer surface is excellent.

  In addition, when the surface treatment of the elastic layer is performed using the predetermined treatment liquid as described above, the treatment is usually performed near room temperature, but the treatment liquid is elasticized at a high temperature as necessary. It is also possible to contact the surface of the layer.

  The method for bringing the treatment liquid into contact with the elastic layer surface is not particularly limited, and various conventionally known methods can be employed. Specifically, a method of coating the treatment liquid on the belt before surface treatment, a method of spraying the treatment liquid on a roll, and the like can be mentioned. In particular, when a pre-surface treatment belt is formed on the surface of a cylindrical substrate according to the above-described method, the cylindrical substrate on which the pre-surface treatment belt is formed has at least a part of the pre-surface treatment belt in a predetermined tank. A method in which the treatment liquid is brought into contact with the entire surface of the belt before the surface treatment by rotating the cylindrical substrate around the axis in such a state is advantageously employed. .

By bringing the treatment liquid into contact with the surface of the belt before surface treatment as described above, the unsaturated bond in the crosslinked rubber constituting the elastic layer (before treatment) is effectively cut, and the following general formula (I ) And a chlorine atom derived from one or more compounds selected from the group consisting of a chlorine compound having a —CONCl— structure in the molecule (and a fluorine atom derived from BF ₃ ) are crosslinked. Effectively introduced into the molecular structure of the rubber, the surface-treated elastic layer has sufficient flexibility and toner adhesion resistance is further improved.
X (OCl) _n (I)
[In the above formula (I), X represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or an alkyl group, and n represents a positive integer. ]

  Then, after bringing the treatment liquid into contact with the surface of the belt before the surface treatment, the surface is washed with a liquid containing water, and if necessary, water droplets are removed by air blow or the like, whereby the electron according to the present invention is obtained. An endless belt for photographic equipment is obtained. In addition, conditions, such as cleaning time in the case of this washing | cleaning, will be determined suitably.

B. Formation of surface layer The surface layer as a protective layer can be produced according to various conventionally known methods using a material mainly composed of a synthetic resin material. Specifically, examples of the synthetic resin material include acrylic fluororesin, silicone resin, fluororesin, acrylic resin, urethane resin, polyamide resin, and the like. In general, in consideration of workability when forming the surface layer. Thus, a liquid or solvent-soluble type synthetic resin material is advantageously used. In addition, a material obtained by modifying the above-described synthetic resin material can also be used in order to prevent contamination of the belt surface and improve the strength and adhesion of the surface layer. For these synthetic resin materials, a resin crosslinking agent is preferably blended. As the resin crosslinking agent, in addition to the above-described phenol resin and the like, an ultraviolet curable material obtained by mixing a photopolymerizer with a photosensitive monomer or photosensitive polymer can also be used.

  As described above in detail, in the endless belt for an electrophotographic apparatus according to the present invention, in the material for the elastic layer, 1) a solvent having a boiling point within a predetermined range is used. Then, the removal of the solvent (desolvation) proceeds after proceeding, and 2) the inorganic filler having a predetermined average particle diameter is blended in a predetermined ratio, thereby (in) the (semi) crosslinked product. In this case, the formation of bubbles in the elastic layer, which is a cross-linked product, is advantageously suppressed, so that the surface smoothness is excellent. It becomes.

  Some examples of the present invention will be shown below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Needless to say. In addition to the following examples, the present invention includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the specific description described above. It should be understood that improvements can be made.

-Preparation of base layer material-
Viromax HR-16NN (trade name) manufactured by Toyobo Co., Ltd. was prepared as a polyamideimide resin (PAI). The polyamideimide resin: 100 parts by weight and carbon black: 10 parts by weight were mixed with N-methyl-2. -Pyrrolidone (NMP): A liquid base layer material was prepared by mixing in 800 parts by weight and mixing.

-Preparation of elastic layer material-
As shown in Table 1 and Table 2 below, 17 kinds of liquid elastic layer materials were prepared by blending and mixing each component at each ratio. In addition, each component used in the preparation is as follows.
・ Chloroprene rubber (CR): Showrene SND16 (trade name), manufactured by Showa Denko KK ・ Acrylonitrile-butadiene rubber (NBR)
: JSR N239SV (trade name), manufactured by JSR Corporation ・ Ethylene-propylene-diene rubber (EPDM)
: Mitsui EPT (trade name), manufactured by Mitsui Chemicals, Inc. ・ Zinc flower (crosslinking agent)
・ Magnesium oxide (crosslinking agent)
・ Sulfur (crosslinking agent)
・ Crosslinking accelerator A: Sunseller 22-C (trade name), manufactured by Sanshin Chemical Industry Co., Ltd. ・ Crosslinking accelerator B: Sunseller TT (trade name), manufactured by Sanshin Chemical Industry Co., Ltd. ・ Resin crosslinking agent: Novolac phenol resin N-775 (trade name), manufactured by DIC Corporation ・ Silica: ML-644 (trade name, average particle size: 2 μm), manufactured by Tokai Chemical Industries, Ltd. ・ Inorganic flame retardant A (aluminum hydroxide)
: B-303 (trade name, average particle size: 3.8 μm), manufactured by Sakai Kogyo Co., Ltd. • Inorganic flame retardant B (magnesium hydroxide)
: Kisuma 5A (trade name, average particle size: 0.8 μm), manufactured by Kyowa Chemical Co., Ltd. ・ Inorganic flame retardant C (antimony trioxide)
: PATOX-M (trade name, average particle size: 0.5 μm), manufactured by Nippon Seiko Co., Ltd. • Inorganic flame retardant D (aluminum hydroxide)
: NOC-308 (trade name, average particle size: 8 μm), manufactured by Sakai Kogyo Co., Ltd. • Organic flame retardant: TMP (trade name), manufactured by Daihachi Chemical Industry Co., Ltd. • Ionic conductive agent: PEL-20A (trade name) ), Manufactured by Nippon Carlit Co., Ltd. Solvent A: Solvesso # 150 (boiling point: 183 ° C.)
Solvent B: Anone (boiling point: 155.7 ° C.)
Solvent C: Toluene (boiling point: 110 ° C.)

-Production of belt-
As a base, an aluminum cylindrical mold was prepared, while a dispenser (liquid quantitative discharge device) having two nozzles was prepared. The nozzle of such a dispenser is a needle nozzle having an inner diameter φ of 1 mm. Next, the previously prepared liquid base layer material and elastic layer material were accommodated in separate material tanks, and the mold and nozzle were set with the clearance between the outer peripheral surface of the mold and the nozzle set to 1 mm. While the mold is vertical, the nozzle for discharging the base layer material is moved downward in the axial direction at a moving speed of 1 mm / sec while rotating around the axis at a rotation speed of 200 rpm, and the material tank is set to 0. The base layer material is pumped to the nozzle by applying a pressure of 4 MPa, the base layer material is discharged from the nozzle, and the outer peripheral surface of the mold is spirally coated, and the entire coating consisting of a continuous spiral coating film is applied. A film was formed. In addition, the thickness of the formed whole coating film was 80 micrometers. A heat treatment (normal temperature → 250 ° C .: 2 hours, 250 ° C .: 1 hour) was performed on the formed whole coating film to form a base layer on the outer peripheral surface of the mold.

  Next, while rotating the mold on which the base layer is formed around the axis at a rotational speed of 200 rpm, the nozzle for discharging the elastic layer material is moved along the axial direction at a moving speed of 1 mm / sec. The elastic layer material is pumped to the nozzle by applying a pressure of 0.8 MPa to the air pressure tank, and the elastic layer material is discharged from the nozzle to form a spiral on the surface of the base layer on the outer peripheral surface of the mold. To form a whole coating film consisting of a continuous spiral coating film. In addition, the thickness of the formed whole coating film was 170 micrometers in Examples 1-11 and Comparative Examples 1-5, and was 10 micrometers in Example 12.

The following heat treatment was carried out on the formed coating film made of each elastic layer material.
1) Elastic layer material prepared using Solvent A or Solvent B a) Material using CR as rubber material and metal oxide as cross-linking agent (hereinafter referred to as CR / metal oxide material) ), NBR / sulfur-based materials and EPDM / sulfur-based materials, the temperature was raised from room temperature to 150 ° C. over 60 minutes, held at 150 ° C. for 30 minutes, and then further in 60 minutes with solvent A. The material using (Solvesso # 150) was heated up to 195 ° C., and the material using Solvent B (anone) was heated up to 170 ° C., and held at each temperature for 30 minutes.
b) For NBR / resin crosslinker-based materials, the temperature was raised from room temperature to 130 ° C. over 60 minutes, held at 130 ° C. for 30 minutes, and then for 60 minutes, solvent A (Solves so # 150) for the material using 150) and up to 170 ° C. for the material using solvent B (anone), respectively, and held at each temperature for 30 minutes.
2) Elastic layer material prepared using solvent C After raising the temperature from room temperature to 120 ° C. for 60 minutes and holding at 120 ° C. for 30 minutes, CR / metal for another 30 minutes. The temperature was raised to 150 ° C. for the oxide-based material and to 130 ° C. for the NBR / resin crosslinking agent-based material, and held at each temperature for 30 minutes.

-Formation of surface layer-
A surface layer was provided on a part of the obtained belt (Examples 1 to 4, 12 and Comparative Examples 1 to 5). First, a liquid surface layer material (solid content: 15%) was prepared by blending each component in the following proportions with toluene as a solvent.
・ Acrylic resin 70 parts by weight [Negami Kogyo Co., Ltd., Precoat 200 (trade name)]
-Fluorine-modified acrylate resin 30 parts by weight [DIC Corporation, Defensor TR230K (trade name)]
・ Crosslinking agent 2 parts by weight [manufactured by Asahi Kasei Corporation, Duranate TPA-B80E (trade name)]
・ 20 parts by weight of carbon black [Mitsubishi Chemical Corporation carbon black MA-100 (trade name)]

  The prepared surface layer material was applied to the surface of a predetermined belt (elastic layer), and then subjected to heat treatment at 150 ° C. for 0.5 hour, thereby allowing Examples 1 to 4, 12 and Comparative Examples 1 to 1. Each belt No. 5 was provided with a surface layer (thickness: 6 μm) made of acrylic fluororesin.

-Surface treatment of elastic layer-
Among the obtained belts, the surface treatment of the elastic layer was performed on predetermined belts (Examples 5 to 11). First, each component is blended at a ratio shown below in a mixed solvent of ethyl acetate and tertiary butyl alcohol (TBA) [ethyl acetate: TBA = 9: 1 (weight ratio)], and surface treatment liquid A (solid Min: 2%) and surface treatment solution B (solid content: 2%).
[Surface treatment liquid A]
-2 parts by weight of t-butyl hypochlorite-9.8 parts by weight of ethyl acetate-88.2 parts by weight of tertiary butyl alcohol [Surface treatment solution B]
-Boron trifluoride-diethyl ether complex 2 parts by weight-Ethyl acetate 9.8 parts by weight-Tertiary butyl alcohol 88.2 parts by weight

  Using a mixed solution of the surface treatment liquid A and the surface treatment liquid B, after applying the roller on the surface of a predetermined belt at room temperature in the atmosphere (coating time: 30 seconds), the belt surface is It was washed with water and water droplets were removed by air blow.

  From the above, 17 types of endless belts for electrophotographic equipment (Examples 1 to 12, Comparative Examples 1 to 5) were produced. And each characteristic of 17 types of obtained belts was measured thru | or evaluated according to the following methods.

-Evaluation of surface smoothness-
According to JIS-B-0601, the surface roughness of the belt surface: Rz (μm) was measured using a surface roughness measuring machine (Surfcom 1400D: trade name) manufactured by Tokyo Seimitsu Co., Ltd. When the measured Rz was 3 or less, it was evaluated as ○, and when it exceeded 3, it was evaluated as ×. The evaluation results for each belt are shown in Table 1 and Table 2 below.

-Image evaluation-
The obtained belt is incorporated into a commercially available multifunction printer (Fuji Xerox Co., Ltd., trade name: DocuCentre-IV C2260) as an intermediate transfer belt, and is against a rippled paper in an environment of 23.5 ° C. × 53% RH. Image printing (test pattern printing) was performed. The obtained image was visually observed and evaluated as ◯ when no image defect such as a white spot image or an untransferred portion was observed, and x when an image defect was observed. The evaluation results for each belt are shown in Table 1 and Table 2 below.

-Evaluation of flame retardancy-
US Underwriters Laboratories Inc. except for using three test pieces. A VTM flammability test was conducted according to UL standard 94 (5th edition, Chapter 11) defined by (UL). Specifically, a film-like test piece cut out from a belt is wound into a cylindrical shape, and is fixed with an adhesive tape or nichrome wire from the end on the clamping side to the end on the opposite side to a position of 75 mm. The test piece in the state was vertically attached to the clamp, flame contact with a 20 mm flame was performed twice for 3 seconds, and the combustion behavior was determined according to the determination conditions shown in Table 3 below. As apparent from Table 3, VTM-0 exhibits the most excellent flame retardancy, and hereinafter, VTM-1 and VTM-2 are obtained, and when VTM-2 is exceeded, Not is obtained. The belt determined as VTM-0 or VTM-1 was evaluated as ◯, and the belt determined as other determination (VTM-2 or Not) was evaluated as ×. The evaluation results for each belt are shown in Table 1 and Table 2 below.

  As is clear from Table 1 and Table 2, the endless belts for electrophotographic equipment according to the present invention (Examples 1 to 12) are both excellent in surface smoothness and used as intermediate transfer belts. It has been confirmed that the toner exhibits excellent toner adhesion resistance and can effectively suppress the occurrence of image defects.

2 Endless belt for electrophotographic equipment 4 Base layer 6 Elastic layer

Claims (11)

An endless belt for electrophotographic equipment in which an elastic layer is provided on the surface of the base layer,
The elastic layer is formed using a liquid elastic layer material in which a rubber material, a crosslinking agent, and an inorganic filler having an average particle diameter of 7 μm or less are blended in a solvent having a boiling point of 150 to 220 ° C. An endless belt for electrophotographic equipment, wherein the inorganic filler is blended in a proportion of 30 to 150 parts by weight with respect to 100 parts by weight of the rubber material.   The endless belt for an electrophotographic apparatus according to claim 1, wherein the elastic layer has a thickness of 10 to 1000 μm.   The endless belt for an electrophotographic apparatus according to claim 1, wherein the crosslinking agent is a metal oxide, sulfur, or a resin crosslinking agent.   The endless belt for an electrophotographic apparatus according to any one of claims 1 to 3, wherein the inorganic filler is silica or an inorganic flame retardant.   The endless belt for an electrophotographic apparatus according to any one of claims 1 to 4, wherein an organic flame retardant is blended in the elastic layer material.   The endless belt for an electrophotographic apparatus according to any one of claims 1 to 5, wherein the elastic layer is formed according to a dispenser coating method.   The endless belt for an electrophotographic apparatus according to any one of claims 1 to 6, wherein the rubber material is CR, NBR, or EPDM.   The endless belt for an electrophotographic apparatus according to any one of claims 1 to 7, wherein the base layer is formed according to a dispenser coating method using a liquid base layer material mainly composed of a synthetic resin material. .   The endless belt for an electrophotographic apparatus according to claim 8, wherein the synthetic resin material is a polyimide resin or a polyamideimide resin. Surface treatment using one or more selected from the group consisting of a chlorine compound represented by the following general formula (I) and a compound having a —CONCl— structure in the molecule and BF ₃ for the elastic layer The endless belt for an electrophotographic apparatus according to any one of claims 1 to 9, wherein the endless belt is provided.
X (OCl) _n (I)
[In the above formula (I), X represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom or an alkyl group, and n represents a positive integer. ] The endless belt for an electrophotographic apparatus according to any one of claims 1 to 9, wherein a surface layer made of an acrylic fluororesin is provided on a surface of the elastic layer.

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