JP2006235538A - Conductive endless belt, its manufacturing method, and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive endless belt having high durability enduring repeated continuous use and assuring a high-quality image without inducing an image defect such as color dropping, and to provide a method for manufacturing the belt and an image forming apparatus using the belt. <P>SOLUTION: The conductive endless belt 100 is provided for transferring and conveying in a tandem system in which the belt holding a recording medium by electrostatic suction is driven to circulate by a driving member to convey the recording medium to four kinds of image forming units and to consecutively transfer the respective toner images onto the recording medium. The belt has a resin layer 102 on a belt base 101 and exhibits ≤3 N/mm<SP>2</SP>universal hardness at the position 5 μm inside from the outermost surface under the measurement conditions of 100 (mN/mm<SP>2</SP>)/60 (sec) constant load accelerated velocity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention supplies a developer to the surface of an image forming body such as a latent image holding body holding an electrostatic latent image on the surface in an electrostatic recording process in an electrophotographic apparatus such as a copying machine or a printer, or an electrostatic recording apparatus. The present invention relates to a conductive endless belt (hereinafter also simply referred to as “belt”) used when transferring a toner image formed in this way onto a recording medium such as paper, a manufacturing method thereof, and an image forming apparatus using the same.

  Conventionally, in an electrostatic recording process in a copying machine, a printer, etc., first, the surface of a photosensitive member (latent image holding member) is uniformly charged, and an image is projected onto the photosensitive member from an optical system and exposed to light. An electrostatic latent image is formed by erasing the charged portion, and then toner is supplied to the electrostatic latent image to form a toner image by electrostatic adhesion of the toner, which is formed on paper, OHP, photographic paper For example, a method of printing by transferring to a recording medium such as the above is employed.

  In this case, color printers and color copiers basically print according to the above process, but in the case of color printing, the color tone is reproduced using toners of four colors, magenta, yellow, cyan, and black. Therefore, a process for obtaining a necessary color tone by superimposing these toners at a predetermined ratio is required, and several methods have been proposed for performing this process.

  First, as in the case of monochrome printing, when the electrostatic latent image is visualized by supplying toner onto the photosensitive member, the four colors of magenta, yellow, cyan, and black are sequentially added. There is a multi-development system in which development is performed by superimposing and a color toner image is formed on the photoreceptor. According to this method, it is possible to configure the apparatus relatively compactly, but this method has a problem in that it is very difficult to control gradation and high image quality cannot be obtained.

  Second, four photosensitive drums are provided, and the latent images on each drum are developed with magenta, yellow, cyan, and black toners, respectively, so that a magenta toner image, a yellow toner image, a cyan toner image, and a black toner image are obtained. By forming four toner images of the toner image, arranging the photosensitive drums on which these toner images are formed in a line, sequentially transferring the toner images onto a recording medium such as paper, and superimposing them on the recording medium, a color image is formed. There is a tandem method to reproduce. Although this method can obtain a good image, the four photosensitive drums, the charging mechanism and the developing mechanism provided for each photosensitive drum are arranged in a line, and the apparatus becomes large and expensive. It becomes.

  FIG. 2 shows a configuration example of a printing unit of a tandem image forming apparatus. A printing unit composed of the photosensitive drum 1, the charging roll 2, the developing roll 3, the developing blade 4, the toner supply roll 5, and the cleaning blade 6 corresponds to each toner of yellow Y, magenta M, cyan C, and black B 4 The toner images are sequentially transferred onto a sheet that is circulated by a driving roller (driving member) 9 and conveyed by a transfer conveying belt 10 to form a color image. Charging and discharging of the transfer / conveying belt are performed by the charging roll 7 and the discharging roll 8, respectively. Further, a suction roller (not shown) is used for charging the paper for sucking the paper onto the belt. Owing to these measures, generation of ozone can be suppressed. The suction roller places the paper on the transfer conveyance belt from the conveyance path and performs electrostatic adsorption on the transfer conveyance belt. Further, the sheet separation after the transfer can be performed only by the curvature separation by lowering the transfer voltage to weaken the adsorption force between the sheet and the transfer conveyance belt.

  As materials for the transfer / conveyance belt 10, there are a resistor and a dielectric, each having advantages and disadvantages. Since the resistor belt can hold charges for a short time, when it is used for tandem transfer, there is little charge injection during transfer, and the voltage rise is relatively small even during continuous transfer of four colors. In addition, when it is repeatedly used for the transfer of the next sheet, the electric charge is released, and no electrical reset is required. However, since the resistance value changes due to environmental fluctuations, there are disadvantages such as affecting transfer efficiency and being easily influenced by the thickness and width of the paper.

  On the other hand, in the case of a dielectric belt, there is no spontaneous release of injected charge, and both charge injection and discharge must be electrically controlled. However, since the charge is stably held, the sheet can be adsorbed reliably and can be conveyed with high accuracy. Since the dielectric constant is less dependent on temperature and humidity, the transfer process is relatively stable to the environment. The drawback is that the transfer voltage increases because charges are accumulated on the belt each time the transfer is repeated.

  Thirdly, a recording medium such as paper is wound around a transfer drum, and this is rotated four times, and magenta, yellow, cyan, and black on the photosensitive member are sequentially transferred to the recording medium every rotation to reproduce a color image. There is also a method. According to this method, a relatively high image quality can be obtained. However, when the recording medium is a cardboard such as a postcard, it is difficult to wind the recording medium around the transfer drum, and the type of the recording medium is limited. There is.

  A system in which good image quality is obtained with respect to the multiple development system, tandem system and transfer drum system, the apparatus is not particularly large, and the type of recording medium is not particularly limited. As an example, an intermediate transfer method has been proposed.

That is, in this intermediate transfer system, an intermediate transfer member composed of a drum or a belt for temporarily transferring and holding the toner image on the photosensitive member is provided, and a magenta toner image, a yellow toner image, and a cyan toner are provided around the intermediate transfer member. An image and four photoconductors on which a black toner image is formed are arranged, and four color toner images are sequentially transferred onto the intermediate transfer member, thereby forming a color image on the intermediate transfer member. The image is transferred onto a recording medium such as paper. Therefore, since the gradation is adjusted by superimposing the four color toner images, it is possible to obtain high image quality, and it is not necessary to arrange the photoconductors in a row as in the tandem method, so that the apparatus can be used. There is no particular increase in size, and there is no need to wrap the recording medium around the drum, so the type of recording medium is not limited.

  As an apparatus for forming a color image by the intermediate transfer method, an image forming apparatus using an endless belt-shaped intermediate transfer member as an intermediate transfer member is illustrated in FIG.

  In FIG. 3, reference numeral 11 denotes a drum-shaped photoconductor, which rotates in the direction of the arrow in the figure. The photosensitive member 11 is charged by the primary charger 12, and then the charged portion of the exposed portion is erased by image exposure 13, and an electrostatic latent image corresponding to the first color component is formed on the photosensitive member 11. The electrostatic latent image is developed with the first color magenta toner M by the developing device 41, and a first color magenta toner image is formed on the photoreceptor 11. Next, the toner image is circulated by a driving roller (driving member) 30 and transferred to the intermediate transfer member 20 that rotates while rotating in contact with the photoreceptor 11. In this case, transfer from the photoconductor 11 to the intermediate transfer member 20 is performed by a primary transfer bias applied from the power source 61 to the intermediate transfer member 20 at the nip portion between the photoconductor 11 and the intermediate transfer member 20. After the first color magenta toner image is transferred to the intermediate transfer member 20, the surface of the photoconductor 11 is cleaned by the cleaning device 14, and the development transfer operation for the first rotation of the photoconductor 11 is completed. Thereafter, the photoconductor rotates three times, and the second color cyan toner image, the third color yellow toner image, and the fourth color black toner image are sequentially used by the developing units 42 to 44 for each turn. The toner image is formed on the intermediate transfer member 20 and is superimposed and transferred to the intermediate transfer member 20 every round, so that a composite color toner image corresponding to the target color image is formed on the intermediate transfer member 20. In the apparatus of FIG. 3, the developing devices 41 to 44 are sequentially replaced with each rotation of the photoreceptor 11 so that development with magenta toner M, cyan toner C, yellow toner Y, and black toner B is sequentially performed. It has become.

  Next, the transfer roller 25 contacts the intermediate transfer member 20 on which the composite color toner image is formed, and a recording medium 26 such as paper is fed from the paper feed cassette 19 to the nip portion. At the same time, a secondary transfer bias is applied from the power source 29 to the transfer roller 25, and the composite color toner image is transferred from the intermediate transfer member 20 onto the recording medium 26 and heated and fixed to form a final image. After the composite color toner image is transferred to the recording medium 26, the transfer residual toner on the surface is removed by the cleaning device 35, and the intermediate transfer member 20 returns to the initial state to prepare for the next image formation.

  There is also a tandem intermediate transfer method that combines a tandem method and an intermediate transfer method. FIG. 4 illustrates an image forming apparatus of a tandem intermediate transfer system that forms a color image using an endless belt-like tandem intermediate transfer member.

  In the illustrated apparatus, the first developing unit 54 a to the fourth developing unit 54 d that develop the electrostatic latent images on the photoconductive drums 52 a to 52 d with yellow, magenta, cyan, and black, respectively, along the tandem intermediate transfer member 50. The four-color toner images formed on the photosensitive drums 52a to 52d of the developing units 54a to 54d are sequentially driven by circulating the tandem intermediate transfer member 50 in the direction of the arrow in the drawing. By transferring, a color toner image is formed on the tandem intermediate transfer member 50, and the toner image is transferred onto a recording medium 53 such as paper to perform printout.

  In the figure, reference numeral 55 denotes a driving roller or tension roller for circulatingly driving the tandem intermediate transfer member 50, reference numeral 56 denotes a recording medium feeding roller, reference numeral 57 denotes a recording medium feeding device, and reference numeral 58 denotes a recording medium. 3 shows a fixing device for fixing the image by heating or the like. Reference numeral 59 denotes a power supply device (voltage applying means) for applying a voltage to the tandem intermediate transfer member 50. The power supply device 59 transfers the toner image from the photosensitive drums 52a to 52d to the tandem intermediate transfer member 50. In this case, the polarity of the applied voltage can be reversed between the case where the image is transferred from the tandem intermediate transfer member 50 onto the recording medium 53.

  As the conductive endless belt used as the transfer conveyance belt 10, the intermediate transfer member 20, the tandem intermediate transfer member 50, etc. in the various image forming apparatuses described above, conventionally, a semiconductive resin film belt and a fiber reinforcement have been provided. Rubber belts are mainly used. Among these, as the resin film belt, for example, Patent Document 1 discloses a conductive endless belt using a thermoplastic polyalkylene naphthalate resin, or a polymer alloy or a polymer blend of the thermoplastic polyalkylene naphthalate resin and another thermoplastic resin as a base material. Are listed.

In Patent Document 2, the surface hardness of the member is regulated to a predetermined value or less by a universal hardness at a depth corresponding to the average particle diameter of the toner used for forming the toner image, thereby preventing the toner from sticking. An intermediate transfer member with improved durability is described, and it is also described that a drum shape or a belt shape is preferable as the intermediate transfer member.
JP 2002-132053 A (Claims etc.) JP 2000-47496 A (Claims, [0012], [FIG. 4], etc.)

  By the way, the conductive endless belt is driven while in contact with the photosensitive member, the transfer member, the cleaning member, etc. at the time of image formation. Therefore, the conductive endless belt has strength that can withstand repeated use on the mechanism surface, that is, durability. Therefore, it is necessary to provide the belt with sufficient rigidity. On the other hand, if the rigidity of the belt is too high, followability to the photoconductor and the like may be deteriorated, and image defects such as color loss may occur. It is also important to have flexibility.

  Conventionally, the hardness of the belt surface has been evaluated based on the degree of deformation at the time when a relatively large constant load of about 1 kg was applied to the belt as represented by Asker C and JIS A. Since the deformation caused by contact with the body or the like is negligible, it is considered that the technique of applying deformation by applying an excessive load is not appropriate in evaluating the belt characteristics. Therefore, by specifying the belt hardness more precisely, the durability and flexibility as the required performance of the belt are highly compatible, and high-quality images can be obtained without problems such as image defects even during repeated use. It has been demanded to realize a belt capable of obtaining the above.

  Accordingly, an object of the present invention is to provide a conductive endless belt that has high durability that can withstand repeated continuous use and that can reliably obtain a high-quality image without causing image defects such as color loss, and a method for manufacturing the same. An object of the present invention is to provide an image forming apparatus using the above.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by defining the hardness of the belt surface using a predetermined hardness parameter, and have completed the present invention.

In other words, the conductive endless belt of the present invention is configured to circulate and drive a recording medium held by electrostatic adsorption to four types of image forming bodies by a driving member, and sequentially transfer each toner image to the recording medium. For conductive endless belts for tandem transfer and transport,
The resin layer is provided on the belt substrate, and the universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) is 3 N / mm ² or less at a position 5 μm inside from the outermost surface. It is characterized by this.

Further, another conductive endless belt of the present invention is disposed between the image forming body and the recording medium, and is circulated and driven by a driving member to temporarily transfer the toner image formed on the surface of the image forming body. In the conductive endless belt for the intermediate transfer member that is transferred and held on the surface and transferred to the recording medium,
The resin layer is provided on the belt substrate, and the universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) is 3 N / mm ² or less at a position 5 μm inside from the outermost surface. It is characterized by this.

Furthermore, another conductive endless belt according to the present invention is disposed between the four types of image forming bodies and the recording medium, and is circulated by a driving member to be formed on the surface of the four types of image forming bodies. In the conductive endless belt for a tandem intermediate transfer member that sequentially transfers and holds the toner images to the surface of the toner, and transfers the toner images to a recording medium.
The resin layer is provided on the belt substrate, and the universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) is 3 N / mm ² or less at a position 5 μm inside from the outermost surface. It is characterized by this.

In the present invention, the resin layer preferably contains a conductive agent, and the resin layer preferably contains an ultraviolet curable resin or an electron beam curable resin as a main component. The universal hardness is preferably in the range of 0.1 to 3 N / mm ² . Furthermore, the thickness of the resin layer is preferably in the range of 1 to 30 μm.

  A method for producing a conductive endless belt according to the present invention is a method for producing the conductive endless belt according to the present invention, wherein the ultraviolet curable resin or electron beam curable resin and a conductive agent are used. A coating solution is applied onto the belt substrate, and the coating solution after coating is cured by irradiation with ultraviolet rays or electron beams to form the resin layer.

  Furthermore, an image forming apparatus according to the present invention includes the conductive endless belt according to the present invention.

  Universal hardness is a hardness parameter that can evaluate the hardness at the time of microdeformation. By using universal hardness as the hardness parameter of the belt surface according to the present invention, the surface characteristics of the belt can be specified more accurately. As a result, it is possible to realize a high-quality belt that has high durability that can withstand repeated and continuous use, and that can reliably obtain high-quality images without causing image defects such as color loss. It became.

Hereinafter, preferred embodiments of the present invention will be described in detail.
In general, the conductive endless belt includes a jointed belt and a jointless belt (so-called seamless belt), but any one may be used in the present invention. A seamless belt is preferable. As described above, the conductive endless belt of the present invention can be used as a transfer member for a tandem system, an intermediate transfer system, and a tandem intermediate transfer system.

  When the conductive endless belt of the present invention is, for example, a transfer conveyance belt indicated by reference numeral 10 in FIG. 2, the toner is sequentially transferred onto a recording medium that is driven by a driving member such as a driving roller 9 and the like. As a result, a color image is formed.

  Further, when the conductive endless belt of the present invention is an intermediate transfer member indicated by reference numeral 20 in FIG. 3, for example, this is circulated by a driving member such as a driving roller 30 and a photosensitive drum (latent image holder) 11 and the recording medium 26 such as paper, the toner image formed on the surface of the photosensitive drum 11 is temporarily transferred and held, and then transferred to the recording medium 26. Note that the apparatus of FIG. 3 performs color printing by the intermediate transfer method as described above.

  Furthermore, when the conductive endless belt of the present invention is, for example, a tandem intermediate transfer member denoted by reference numeral 50 in FIG. 4, the developing units 54a to 54d including the photosensitive drums 52a to 52d and the recording medium 53 such as paper are provided. The four-color toner images formed on the surfaces of the photosensitive drums 52 a to 52 d are temporarily transferred and held, and then transferred to the recording medium 53. Are transferred to form a color image.

The conductive endless belt of the present invention is a belt having a laminated structure having a resin layer on a belt substrate, and has a universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds). 5μm only inside of 3N / mm ² or less at a position from the surface, preferably it is characterized in that in the range of 0.1~3N / mm ^2. By defining the belt hardness using universal hardness, it is possible to realize a belt having more appropriate surface characteristics.

Such universal hardness is a physical property value obtained by pushing an indenter into a measurement object while applying a load.
(Test load) / (Indenter surface area under test load)
And the unit is expressed in N / mm ² . The universal hardness can be measured using, for example, a commercially available hardness measuring device such as an ultra micro hardness meter H-100V manufactured by Fischer. In this measuring device, a square or triangular pyramid-shaped indenter is pushed into the object to be measured while applying a predetermined relatively small test load, and when the predetermined indentation depth is reached, the indenter contacts from the indentation depth. The surface area is determined, and the universal hardness can be determined from the above formula. That is, when the indenter is pushed into the object to be measured under a constant load measurement condition, the stress at that time with respect to the pushed-in depth is defined as universal hardness.

  In the present invention, the indentation depth is 5 μm from the outermost surface. The indentation depth corresponds to the deformation amount, that is, according to the universal hardness required under such conditions, the belt hardness in a depth region within 5 μm from the outermost surface of the belt can be directly evaluated, This is extremely effective in determining the belt characteristics.

  In the belt of the present invention, the structure, material, and the like are not particularly limited as long as the conditions related to the universal hardness are satisfied.

  FIG. 1 shows a partial sectional view of a preferred example of the conductive endless belt of the present invention. The illustrated belt 100 has a two-layer structure in which a resin layer 102 is provided on a belt base 101. In the belt 100 having such a laminated structure, the predetermined universal hardness can be realized by appropriately selecting the material composition of the resin layer 102 formed on the surface. A material used for the resin layer 102 is not particularly limited, but in particular, an ultraviolet curable resin or an electron beam curable resin is used as a main component, and a conductive agent is blended in the resin layer 102. Is preferably formed.

  In the case of a general thermosetting resin, the resin layer 102 is formed using an ultraviolet curable resin or an electron beam curable resin, thereby appropriately controlling an irradiation amount of ultraviolet rays (UV) or an electron beam. The resin layer 102 can be cured and formed more easily and reliably in a shorter time, and a drying line for curing required when using a thermosetting resin is unnecessary. Since it can do, there also exists an advantage which can reduce the cost required for production significantly compared with the case where it forms with a thermosetting resin.

  Although the resin layer 102 is a single layer in the illustrated example, the resin layer 102 may be composed of a plurality of layers having different materials and physical properties. In that case, at least one of the layers is composed of the ultraviolet curable resin or the electronic material. It is preferable to include a linear curable resin and a conductive agent.

In the present invention, the ultraviolet curable resin refers to a resin that is cured by irradiation with ultraviolet rays (UV) having a wavelength of about 200 to 400 nm, and usually comprises a prepolymer, a monomer, an ultraviolet polymerization initiator, and an additive. Further, in the present invention, the electron beam curable resin does not contain a crosslinking agent, a polymerization initiator, or a cleavage aid, and has the property of proceeding self-crosslinking by energy by electron beam irradiation without using these aids. It shall mean the resin it has. However, in actual production, these may be blended with a crosslinking agent or the like to form a layer, and the electron beam curable resin according to the present invention does not refuse blending with these crosslinking agents or the like.

  Specific examples of ultraviolet curable resins and electron beam curable resins include polyester resins, polyether resins, fluororesins, epoxy resins, amino resins, polyamide resins, acrylic resins, acrylic urethane resins, urethane resins, and alkyd resins. , Phenol resin, melamine resin, urea resin, silicone resin, polyvinyl butyral resin, and the like. These can be used alone or in combination.

  In addition, modified resins in which specific functional groups are introduced into these resins can be used, and in particular, those having a crosslinked structure are introduced in order to improve the mechanical strength and environmental resistance characteristics of the resin layer 102. Is preferred.

Among the above resins, a (meth) acrylate resin containing a (meth) acrylate oligomer is particularly preferable.

  Examples of such (meth) acrylate oligomers include urethane (meth) acrylate oligomers, epoxy (meth) acrylate oligomers, ether (meth) acrylate oligomers, ester (meth) acrylate oligomers, and polycarbonate (meth). Examples include acrylate oligomers, and fluorine-based and silicone-based (meth) acrylic oligomers.

  The (meth) acrylate oligomer is composed of a compound such as polyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, bisphenol A type epoxy resin, phenol novolac type epoxy resin, adduct of polyhydric alcohol and ε-caprolactone, It can be synthesized by reaction with (meth) acrylic acid or by urethanizing a polyisocyanate compound and a (meth) acrylate compound having a hydroxyl group.

  The urethane-based (meth) acrylate oligomer can be obtained by urethanizing a polyol, an isocyanate compound and a (meth) acrylate compound having a hydroxyl group.

  Examples of the epoxy-based (meth) acrylate oligomer may be any reaction product of a compound having a glycidyl group and (meth) acrylic acid, but among them, a benzene ring, a naphthalene ring, a spiro ring, a dicyclo ring. A reaction product of a compound having a cyclic structure such as pentadiene or tricyclodecane and having a glycidyl group and (meth) acrylic acid is preferred.

  Furthermore, ether-based (meth) acrylate oligomers, ester-based (meth) acrylate oligomers, and polycarbonate-based (meth) acrylate oligomers correspond to polyols (polyether polyol, polyester polyol, and polycarbonate polyol) and (meth) acrylic acid, respectively. It can obtain by reaction of.

  These ultraviolet curable resins and electron beam curable resins contain a reactive diluent having a polymerizable double bond for viscosity adjustment as desired. As such a reactive diluent, for example, 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 Etc. can be used. These diluents are usually preferably used in an amount of 10 to 200 parts by weight per 100 parts by weight of the (meth) acrylate oligomer.

  Further, the ultraviolet curable resin contains an ultraviolet polymerization initiator for accelerating the initiation of the curing reaction by irradiation with ultraviolet rays. The ultraviolet polymerization initiator is not particularly limited, and known ones can be used. In particular, when a carbon-based conductive agent is used in the resin layer 102, the irradiated ultraviolet rays are carbon-based. Since the conductive agent does not reach the inside of the resin layer 102 and there is a possibility that the curing reaction does not proceed without fully functioning the ultraviolet polymerization initiator, it is sensitive to long wavelength ultraviolet rays that easily enter the resin layer 102. It is preferable to use an ultraviolet polymerization initiator having the same.

  Specifically, an ultraviolet polymerization initiator having a maximum wavelength in the ultraviolet absorption wavelength band of 400 nm or more is preferably used. As such an ultraviolet polymerization initiator having an absorption band at a long wavelength, α-aminoacetophenone, acylphosphine oxide, thioxanthonenoamine and the like can be used. More specific examples of these include bis (2 , 4,6-trimethylbenzoyl) -phenylphosphine oxide or 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one.

  In this case, as the ultraviolet polymerization initiator, in addition to the above, it is preferable to further contain an ultraviolet polymerization initiator having a maximum wavelength in the ultraviolet absorption wavelength band of less than 400 nm. When it is contained, the curing reaction can be favorably advanced not only inside the resin layer 102 but also in the vicinity of the surface of the resin layer 102.

Examples of the ultraviolet polymerization initiator having an absorption band at such a short wavelength include 2,2-dimethoxy 1,2 diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, 2-hydroxy 2-methyl-1- Phenylpropan-1-one, 1- [4- (2hydroxyethoxy) phenyl] 2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4-phenyl] -2-morpho And linopropan-1-one.

  As a compounding quantity of this ultraviolet-ray polymerization initiator, it is preferable to set it as 0.1-10 weight part per 100 weight part of (meth) acrylate oligomers, for example.

  When using an ultraviolet curable resin, in addition to the above components, a tertiary amine such as triethylamine or triethanolamine, triphenylphosphine, or the like is used in order to accelerate the polymerization reaction using the ultraviolet polymerization initiator as necessary. Alkylphosphine photopolymerization accelerators, thioether photopolymerization accelerators such as p-thiodiglycol, and the like may be added to the ultraviolet curable resin. When these compounds are added, the addition amount is usually preferably in the range of 0.01 to 10 parts by weight per 100 parts by weight of the (meth) acrylate oligomer.

  Further, when the resin layer 102, in particular, the outermost resin layer 102 is made of an ultraviolet curable resin or an electron beam curable resin, the ultraviolet curable resin or the electron beam curable resin is made of fluorine and silicon. It is preferable to contain one or both of them, whereby the surface energy of the resin layer 102 can be reduced, and as a result, the frictional resistance of the belt surface is reduced and the toner releasability is also improved. It is possible to reduce wear during long-term use and improve durability.

  As a raw material for ultraviolet curable resin or electron beam curable resin containing fluorine, it is preferable to contain a fluorine-containing compound having a polymerizable carbon-carbon double bond. A composition comprising only a fluorine-containing compound having a polymer, and a blend of a fluorine-containing compound having a polymerizable carbon-carbon double bond and another kind of polymerizable compound having a carbon-carbon double bond It may be made up of.

  As the fluorine-containing compound having a polymerizable double bond between carbon atoms, fluoroolefins and fluoro (meth) acrylates are suitable.

As the fluoroolefin, those having 2 to 12 carbon atoms in which 1 to all hydrogen atoms are substituted with fluorine are preferable. Specifically, hexafluoropropene [CF ₃ CF═CF ₂ , fluorine content 76 % By weight], (perfluorobutyl) ethylene [F (CF ₂ ) ₄ CH═CH ₂ , fluorine content 69% by weight], (perfluorohexyl) ethylene [F (CF ₂ ) ₆ CH═CH ₂ , containing fluorine 71% by weight], (perfluorooctyl) ethylene [F (CF ₂ ) ₈ CH═CH ₂ , fluorine content 72% by weight], (perfluorodecyl) ethylene [F (CF ₂ ) ₁₀ CH═CH ₂ , Fluorine content 73 wt%], chlorotrifluoroethylene [CF ₂ = CFCl, fluorine content 49 wt%], 1-methoxy- (perfluoro-2-methyl-1-propene [ (CF ₃ ) ₂ C═CFOCH ₃ , fluorine content 63 wt%], 1,4-divinyloctafluorobutane [(CF ₂ ) ₄ (CH═CH ₂ ) ₂ , fluorine content 60 wt%], 1, 6-divinyldodecafluorohexane [(CF ₂ ) ₆ (CH═CH ₂ ) ₂ , fluorine content 64 wt%], 1,8-divinylhexadecafluorooctane [(CF ₂ ) ₈ (CH═CH ₂ ) ₂ , Fluorine content 67 wt%].

As the fluoro (meth) acrylate, a fluoroalkyl (meth) acrylate having 5 to 16 carbon atoms in which 1 to all hydrogen atoms are substituted with fluorine is preferable. Fluoroethyl acrylate (CF ₃ CH ₂ OCOCH═CH ₂ , fluorine content 34% by weight), 2,2,3,3,3-pentafluoropropyl acrylate (CF ₃ CF ₂ CH ₂ OCOCH═CH ₂ , fluorine content 44 wt%), F (CF ₂ ) ₄ CH ₂ CH ₂ OCOCH═CH ₂ (fluorine content 51 wt%), 2,2,2-trifluoroethyl acrylate [CF ₃ CH ₂ OCOCH═CH ₂ , containing fluorine rate 37% by weight], 2,2,3,3,3-pentafluoro-propyl acrylate _{[CF 3 CF 2 CH 2 OCOCH} = CH 2, the fluorine content 4 Wt%], 2- (perfluorobutyl) ethyl acrylate _{[F (CF 2) 4 CH} 2 CH 2 OCOCH = CH 2, fluorine content 54 wt%], 3- (perfluorobutyl) -2-hydroxypropyl acrylate [F (CF ₂ ) ₄ CH ₂ CH (OH) CH ₂ OCOCH═CH ₂ , fluorine content 49 wt%], 2- (perfluorohexyl) ethyl acrylate [F (CF ₂ ) ₆ CH ₂ CH ₂ OCOCH = CH _2, fluorine content 59 wt%], 3- (perfluorohexyl) -2-hydroxypropyl acrylate _{[F (CF 2) 6 CH} 2 CH (OH) CH 2 OCOCH = CH 2, fluorine content 55 wt% ], 2- (perfluorooctyl) ethyl acrylate _{[F (CF 2) 8 CH} 2 CH 2 OCOCH = CH 2, fluorine content 62 wt% 3- (perfluorooctyl) -2-hydroxypropyl acrylate _{[F (CF 2) 8 CH} 2 CH (OH) CH 2 OCOCH = CH 2, fluorine content 59 wt%], 2- (perfluoro decyl) ethyl acrylate [F (CF ₂ ) ₁₀ CH ₂ CH ₂ OCOCH═CH ₂ , fluorine content 65 wt%], 2- (perfluoro-3-methylbutyl) ethyl acrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₂ CH ₂ CH ₂ OCOCH═CH ₂ , fluorine content 57 wt%], 3- (perfluoro-3-methylbutyl) -2-hydroxypropyl acrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₂ CH ₂ CH (OH) CH ₂ OCOCH = CH _2, fluorine content 52 wt%], 2- (perfluoro-5-methylhexyl) ethyl acrylate [(CF _{3) 2} CF ( _{F 2) 4 CH 2 CH 2} OCOCH = CH 2, fluorine content 61 wt%], 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl acrylate _{[(CF 3) 2 CF (} CF 2) 4 CH ₂ CH (OH) CH ₂ OCOCH═CH ₂ , fluorine content 57 wt%], 2- (perfluoro-7-methyloctyl) ethyl acrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₆ CH ₂ CH ₂ OCOCH = CH _2, fluorine content 64 wt], 3- (perfluoro-7-methyl-octyl) -2-hydroxypropyl acrylate _{[(CF 3) 2 CF (} CF 2) 6 CH 2 CH (OH) CH 2 OCOCH = CH ₂ , fluorine content 60 wt%], 1H, 1H, 3H-tetrafluoropropyl acrylate [H (CF ₂ ) ₂ CH ₂ OCOCH = CH ₂ , fluorine content 41% by weight], 1H, 1H, 5H-octafluoropentyl acrylate [H (CF ₂ ) ₄ CH ₂ OCOCH═CH ₂ , fluorine content 53% by weight], 1H, 1H, 7H-dodecafluoroheptyl acrylate [H (CF ₂ ) ₆ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 59 wt%], 1H, 1H, 9H-hexadecafluorononyl acrylate [H (CF ₂ ) ₈ CH ₂ OCOCH═CH ₂ , fluorine Content 63 wt%], 1H-1- (trifluoromethyl) trifluoroethyl acrylate [(CF ₃ ) ₂ CHOCOCH═CH ₂ , fluorine content 51 wt%], 1H, 1H, 3H-hexafluorobutyl acrylate [ _{CF 3 CHFCF 2 CH 2 OCOCH =} CH 2, fluorine content 48 wt%, 2,2,2-trifluoroethyl main Acrylate _{[CF 3 CH 2 OCOC (CH} 3) = CH 2, fluorine content 34 wt%], 2,2,3,3,3-pentafluoro-propyl methacrylate _{[CF 3 CF 2 CH 2 OCOC} (CH 3) = CH ₂ , fluorine content 44 wt%], 2- (perfluorobutyl) ethyl methacrylate [F (CF ₂ ) ₄ CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 51 wt%], 3- (Perfluorobutyl) -2-hydroxypropyl methacrylate [F (CF ₂ ) ₄ CH ₂ CH (OH) CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 47 wt%], 2- (perfluorohexyl) methacrylate _{[F (CF 2) 6 CH} 2 CH 2 OCOC (CH 3) = CH 2, fluorine content 57 wt%], 3- (perfluorohexyl) -2-hydro Shi methacrylate _{[F (CF 2) 6 CH} 2 CH (OH) CH 2 OCOC (CH 3) = CH 2, fluorine content 53 wt%], 2- (perfluorooctyl) ethyl methacrylate [F (CF _{2) 8} CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 61 wt%], 3-perfluorooctyl-2-hydroxypropyl methacrylate [F (CF ₂ ) ₈ CH ₂ CH (OH) CH ₂ OCOC ( CH ₃ ) = CH ₂ , fluorine content 57 wt%], 2- (perfluorodecyl) ethyl methacrylate [F (CF ₂ ) ₁₀ CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 63 wt% ], 2- (perfluoro-3-methylbutyl) ethyl methacrylate _{[(CF 3) 2 CF (} CF 2) 2 CH 2 CH 2 OCOC (CH 3) = CH 2, fluoride Content of 55 wt%], 3- (perfluoro-3-methylbutyl) -2-hydroxypropyl methacrylate _{[(CF 3) 2 CF (} CF 2) 2 CH 2 CH (OH) CH 2 OCOC (CH 3) = CH ₂ , fluorine content 51% by weight], 2- (perfluoro-5-methylhexyl) ethyl methacrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₄ CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , containing fluorine 59% by weight], 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl methacrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₄ CH ₂ CH (OH) CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 56% by weight], 2- (perfluoro-7-methyloctyl) ethyl methacrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₆ CH ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 62 wt%], 3- (perfluoro-7-methyloctyl) -2-hydroxypropyl methacrylate [(CF ₃ ) ₂ CF (CF ₂ ) ₆ CH ₂ CH (OH) CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 59 wt%], 1H, 1H, 3H-tetrafluoropropyl methacrylate [H (CF ₂ ) ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 51 wt% ] 1H, 1H, 5H-octafluoropentyl methacrylate [H (CF ₂ ) ₄ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 51 wt%], 1H, 1H, 7H-dodecafluoroheptyl methacrylate [H _{(CF 2) 6 CH 2 OCOC} (CH 3) = CH 2, fluorine content 57 wt%], 1H, 1H, 9H- hexadecafluoro nonyl meth click relay _{[H (CF 2) 8 CH} 2 OCOC (CH 3) = CH 2, fluorine content 61 wt%], 1H-1- (trifluoromethyl) trifluoroethyl methacrylate _{[(CF 3) 2 CHOCOC (} CH 3) = CH ₂ , fluorine content 48 wt%], 1H, 1H, 3H-hexafluorobutyl methacrylate [CF ₃ CHFCF ₂ CH ₂ OCOC (CH ₃ ) = CH ₂ , fluorine content 46 wt%] Can do.

  The fluorine-containing compound having a polymerizable double bond between carbon atoms is preferably a monomer, an oligomer, or a mixture of a monomer and an oligomer. As an oligomer, a 2-20 mer is preferable.

  The compound having another polymerizable double bond between carbon atoms that may be blended with the fluorine-containing compound having a double bond between carbon atoms is not particularly limited. ) Acrylate monomers or oligomers or mixtures of monomers and oligomers are preferred.

  Examples of the (meth) acrylate monomer or oligomer include urethane (meth) acrylate, epoxy (meth) acrylate, ether (meth) acrylate, ester (meth) acrylate, polycarbonate (meth) acrylate, and the like. Or an oligomer, the monomer of a silicone type (meth) acryl, an oligomer, etc. can be mentioned.

  The (meth) acrylate oligomer is composed of a compound such as polyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, bisphenol A type epoxy resin, phenol novolac type epoxy resin, adduct of polyhydric alcohol and ε-caprolactone, It can be synthesized by reaction with (meth) acrylic acid or by urethanizing a polyisocyanate compound and a (meth) acrylate compound having a hydroxyl group.

  A urethane type (meth) acrylate oligomer is obtained by urethanizing a polyol, an isocyanate compound, and a (meth) acrylate compound having a hydroxyl group.

  Examples of the epoxy-based (meth) acrylate oligomer may be any reaction product of a compound having a glycidyl group and (meth) acrylic acid, but among them, a benzene ring, a naphthalene ring, a spiro ring, a dicyclo ring. A reaction product of a compound having a cyclic structure such as pentadiene or tricyclodecane and having a glycidyl group and (meth) acrylic acid is preferred.

  Furthermore, ether-based (meth) acrylate oligomers, ester-based (meth) acrylate oligomers, and polycarbonate-based (meth) acrylate oligomers correspond to polyols (polyether polyol, polyester polyol, and polycarbonate polyol) and (meth) acrylic acid, respectively. It can obtain by reaction of.

  The raw material for forming the ultraviolet curable resin or electron beam curable resin containing silicon preferably contains a silicon-containing compound having a polymerizable double bond between carbon atoms. It may be composed of only a silicon-containing compound having a double bond, or a silicon-containing compound having a polymerizable carbon-carbon double bond and another type of compound having a polymerizable carbon-carbon double bond. It may consist of a blended composition.

  As the silicon-containing compound having a polymerizable double bond between carbon atoms, both-end-reactive silicone oils, one-end-reactive silicone oils, and (meth) acryloxyalkylsilanes are suitable. As the reactive silicone oil, those having a (meth) acryl group introduced at the terminal are preferable.

Specific examples of the silicon-containing compound suitably used in the present invention are shown below.
It is the Shin-Etsu Chemical Co., Ltd. both-ends reactive silicone oil (it has a functional group shown by following formula (1)) shown in following Table 1.

（上記式（２）中、Ｒ¹はメチル基またはブチル基であり、Ｒ²は前記式（１）で示される官能基である） It is the Shin-Etsu Chemical Co., Ltd. one terminal reactive silicone oil (it has a structure shown by following formula (2)) shown in following Table 2.

(In the above formula (2), R ¹ is a methyl group or a butyl group, and R ² is a functional group represented by the formula (1)).

This is a double-end methacrylate-modified silicone oil (having a structure represented by the following formula (3)) manufactured by Toray Dow Corning Silicone Co., Ltd. shown in Table 3 below.

It is a one-end methacrylate-modified silicone oil (having a structure represented by the following formula (4)) manufactured by Toray Dow Corning Silicone Co., Ltd. shown in Table 4 below.

These are (meth) acryloxyalkylsilanes (in order, having the structures represented by the following formulas (5) to (11)) manufactured by Shin-Etsu Chemical Co., Ltd. shown in Table 5 below.

  These silicon-containing compounds may be used alone or in combination of two or more, or may be used in combination with other compounds having no carbon-containing double bond.

  These silicon-containing compounds having a polymerizable carbon-carbon double bond and other compounds having no carbon-containing carbon-carbon double bond are preferably used as a monomer, an oligomer, or a mixture of a monomer and an oligomer.

  The other compound having a polymerizable double bond between carbon atoms that may be blended with the silicon-containing compound having a polymerizable double bond between carbon atoms is not particularly limited. ) Acrylate monomers or oligomers or mixtures of monomers and oligomers are preferred. As an oligomer, a 2-20 mer is preferable.

  Examples of the (meth) acrylate monomer or oligomer include urethane (meth) acrylate, epoxy (meth) acrylate, ether (meth) acrylate, ester (meth) acrylate, polycarbonate (meth) acrylate, and the like. And fluorine-based (meth) acrylic monomers or oligomers.

  The (meth) acrylate oligomer is composed of a compound such as polyethylene glycol, polyoxypropylene glycol, polytetramethylene ether glycol, bisphenol A type epoxy resin, phenol novolac type epoxy resin, adduct of polyhydric alcohol and ε-caprolactone, It can be synthesized by reaction with (meth) acrylic acid or by urethanizing a polyisocyanate compound and a (meth) acrylate compound having a hydroxyl group.

  The urethane-based (meth) acrylate oligomer can be obtained by urethanizing a polyol, an isocyanate compound and a (meth) acrylate compound having a hydroxyl group.

  Examples of the epoxy-based (meth) acrylate oligomer may be any reaction product of a compound having a glycidyl group and (meth) acrylic acid. Among them, a benzene ring, a naphthalene ring, a spiro ring, a dicyclopentadiene, A reaction product of a compound having a cyclic structure such as tricyclodecane and having a glycidyl group and (meth) acrylic acid is preferred.

  Furthermore, ether-based (meth) acrylate oligomers, ester-based (meth) acrylate oligomers, and polycarbonate-based (meth) acrylate oligomers correspond to polyols (polyether polyol, polyester polyol, and polycarbonate polyol) and (meth) acrylic acid, respectively. It can obtain by reaction of.

  Further, the conductive agent is not particularly limited, and an electronic conductive agent, an ionic conductive agent, or the like is used.

  Specific examples of the electronic conductive agent include conductive carbon such as ketjen black and acetylene black, rubber carbon such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT, and oxidation treatment. Carbon (ink) carbon, pyrolytic carbon, natural graphite, artificial graphite, antimony-doped tin oxide, titanium oxide, zinc oxide, nickel, copper, silver, germanium and other metals and metal oxides, polyaniline, polypyrrole, Examples include conductive whiskers such as conductive polymers such as polyacetylene, carbon whiskers, graphite whiskers, titanium carbide whiskers, conductive potassium titanate whiskers, conductive barium titanate whiskers, conductive titanium oxide whiskers, and conductive zinc oxide whiskers. It is done.

The blending amount of these electronic conductive agents is usually 100 parts by weight or less, for example, 1 to 100 parts by weight, particularly 1 to 80 parts by weight, especially 10 to 50 parts by weight, based on 100 parts by weight of the resin.
However, when the carbon-based conductive agent is contained in the ultraviolet curable resin, it is preferably 20 parts by weight or less, particularly 10 parts by weight or less, especially 5 parts by weight or less based on 100 parts by weight of the resin. When the amount exceeds the parts by weight, the carbon-based conductive agent easily absorbs ultraviolet rays, so the larger the amount of the conductive agent, the more difficult it is for the ultraviolet rays to reach the back of the resin layer, and the progress of the ultraviolet curing reaction does not proceed sufficiently. There is a risk that.

  Specific examples of the ionic conductive agent include perchlorates and chlorates such as tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and modified fatty acid dimethylethylammonium. , Ammonium salts such as hydrochloride, bromate, iodate, borofluoride, sulfate, ethyl sulfate, carboxylate, sulfonate, alkali such as lithium, sodium, potassium, calcium, magnesium Metal, alkaline earth metal perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, trifluoromethyl sulfate, sulfonate, etc. . The compounding amount of these ionic conductive agents is usually 0.01 to 10 parts by weight, particularly 0.05 to 5 parts by weight with respect to 100 parts by weight of the resin.

  In addition, the said electrically conductive agent may be used individually by 1 type, or may be used in combination of 2 or more types, for example, it can also be used combining an electronic conductive agent and an ionic conductive agent, In this case, it is applied. Therefore, the conductivity can be stably expressed even with respect to fluctuations in voltage and environmental changes.

  In addition, when the conductive agent is a transparent conductive agent such as tin oxide, titanium oxide, zinc oxide, potassium titanate, barium titanate, nickel, copper, and other metals and metal oxides, ultraviolet rays are easily transmitted and ultraviolet curing is achieved. The effect of not hindering the polymerization of the mold resin is obtained. The blending amount of the transparent conductive agent is usually 100 parts by weight or less, particularly 1 to 80 parts by weight, particularly 10 to 50 parts by weight, based on 100 parts by weight of the resin.

  Here, the resin layer 102 is preferably one having an insoluble content with respect to a solvent (a good solvent such as acetone) of 70% by weight or more. If the solvent-insoluble content is less than 70% by weight, a single molecular weight shift occurs in the pressure contact area of other members that are in contact with the belt surface such as a photoconductor when left for a long period of time, resulting in problems such as black horizontal lines in the image. There is a risk. From such points, the solvent-insoluble content is more preferably 70% by weight or more.

  As a method for forming the resin layer 102, a method in which a coating liquid containing the resin component, the conductive agent, and other additives is applied onto the belt base 101 and cured by irradiation with ultraviolet rays or electron beams, respectively, is preferable. Can be used. This coating solution is preferably formed without a solvent, or a solvent having high volatility at room temperature may be used as a solvent. By using such a method, it is possible to save a large amount of equipment and space for drying, which is necessary when drying and curing using heat or hot air, and to reduce variations in film formation. In this way, the resin layer 102 can be formed with high accuracy.

  As a method for applying the coating liquid, a dipping method in which the belt substrate 101 is immersed in the coating liquid, a spray coating method, a roll coating method, or the like can be appropriately selected and used depending on the situation. .

Moreover, as a light source for irradiating with ultraviolet rays, any of commonly used mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, xenon lamps and the like can be used. The conditions for ultraviolet irradiation may be appropriately selected according to the type and application amount of the ultraviolet curable resin, but an illuminance of 100 to 700 mW / cm ² and an integrated light amount of 200 to 3000 mJ / cm ² are appropriate.

The thickness of the resin layer 102 is not particularly limited, but is usually 1 to 30 μm, particularly 2 to 20 μm, and particularly preferably about 3 to 10 μm. If the thickness is too thin, charging performance on the belt surface may not be sufficiently secured due to friction during long-term use. On the other hand, if the thickness is too thick, the belt surface strength cannot be sufficiently maintained and continuous operation is performed. Sometimes trouble occurs. The volume resistivity of the resin layer 102 is preferably in the range of 10 ⁴ to 10 ¹³ centimeters.

  Further, the base resin of the belt base 101 is not particularly limited, and can be appropriately selected from conventionally known materials. Specifically, for example, thermoplastic polyamide (PA), heat Thermoplastic polyalkylene naphthalate resin such as plastic polyarylate (PAR), thermoplastic polyacetal (POM), thermoplastic polyethylene naphthalate (PEN) resin and thermoplastic polybutylene naphthalate (PBN) resin, thermoplastic polyethylene terephthalate (PET) ) And thermoplastic polyalkylene terephthalate resins such as thermoplastic polybutylene terephthalate (PBT) resins. Further, any two or more polymer alloys or polymer blends of these resins, or any one or more of these resins and other thermoplastic resins, in particular, a polymer alloy or polymer blend of a thermoplastic elastomer. Etc. may be used.

  Thermoplastic polyamide is one of the resins that have been used for a long time as a material with good wear resistance, is excellent in strength, impact resistance, and the like, and can be easily obtained in the market. There are several types of PAs, and in particular, nylon 12 (hereinafter referred to as “PA12”), for example, manufactured by Toray Industries, Inc., trade names: Rilsan AESN O TL, Daicel Huls Co., Ltd., trade names : DAIAMID L2101, DAIAMID L1940, Ube Industries, Ltd., trade name: 3024U, etc. can be used suitably. PA12 is superior to other PAs in dimensional stability with respect to environmental fluctuations. PA6 is also suitable. By using such a thermoplastic polyamide as the base resin of the belt base 101, a conductive endless belt having no variation in resistance and excellent in strength, in particular, bending durability can be obtained. The PA12 is preferably a number average molecular weight of 7000 to 100,000, more preferably 13,000 to 40,000.

  As a suitable polymer alloy of PA and thermoplastic elastomer, a block copolymer alloy of PA12 and thermoplastic polyether can be exemplified. Thereby, in addition to dimensional stability, the effect excellent also in the improvement of the low temperature characteristic can be acquired. Such a polymer alloy of PA12 and a thermoplastic polyether can also be obtained on the market. For example, a product name: Daiamide X4442 manufactured by Daicel Huls Co., Ltd. can be cited as a representative example.

Further, as a thermoplastic elastomer that can be suitably used for a polymer blend with PA, a polymer having a Young's modulus of 98000 N / cm ² or less, preferably 980 to 49000 N / cm ² , is known. Polyether-based, polyolefin-based, polyurethane-based, styrene-based, acrylic-based, and polydiene-based elastomers can be used. By blending such a thermoplastic elastomer, the number of foldings can be increased and the durability against cracks can be enhanced. A polymer blend of PA12 and a thermoplastic elastomer is also available on the market. For example, trade name: Daiamide E1947 manufactured by Daicel Huls Co., Ltd. can be mentioned.

  The blending ratio in the polymer alloy and polymer blend of PA and thermoplastic elastomer in the present invention is preferably 100 parts by weight or less of thermoplastic elastomer with respect to 100 parts by weight of PA12 when PA is PA12. It is.

  Thermoplastic polyarylate is an engineering plastic that is excellent in impact resistance and dimensional stability and has good elastic recovery properties, and can be easily obtained in the market, such as U-100 manufactured by Unitika Ltd. Can be mentioned representatively. By using such a PAR as a base material for a conductive endless belt, there can be obtained a conductive endless belt having no variation in resistance, excellent in strength, in particular, bending durability and creep resistance, and having high dimensional accuracy.

  Preferable examples of the polymer alloy or polymer blend of PAR include a polymer alloy with thermoplastic polycarbonate (PC) or thermoplastic polyethylene terephthalate (PET). Polymer alloys and polymer blends of such PAR and thermoplastic resins can also be obtained on the market, for example, P-3001 made by Unitika Ltd. as an alloy with PC, Unitika as an alloy with PET ( A typical example is U-8000 manufactured by Co., Ltd.

  The thermoplastic polyacetal may be a homopolymer or a copolymer, but a copolymer is preferable from the viewpoint of thermal stability. POM is an engineering plastic that is often used in plastic gears and the like because it has a good balance of strength, wear resistance, dimensional stability, moldability, etc. Representative examples include Asahi Kasei Co., Ltd., trade name: Tenac 2010, Polyplastics Co., Ltd., trade name: Duracon M25-34, and the like. By using such POM as the base material of the conductive endless belt, there can be obtained a conductive endless belt having no resistance variation, excellent strength, in particular bending durability and creep resistance, and high dimensional accuracy.

  Among the polymer alloys of POM, a polymer alloy with thermoplastic polyurethane can be cited as a preferable material. This provides an effect that is excellent in impact resistance in addition to the above characteristics. A polymer alloy of POM and thermoplastic polyurethane can also be obtained on the market. For example, Asahi Kasei Co., Ltd. product name: Tenac 4012 can be representatively listed.

  In addition, examples of the thermoplastic elastomer that can be suitably used for the polymer blend with POM include those similar to the case of PA described above. Also in this case, the number of foldings can be increased and the durability against cracks can be increased by the effect of blending with the thermoplastic elastomer.

  Thermoplastic polyalkylene naphthalate resins are engineering plastics that are excellent in impact resistance, dimensional stability and weather resistance, and have good elastic recovery properties, and are easily available in the market. Specific examples include thermoplastic polyethylene naphthalate (PEN) resin and thermoplastic polybutylene naphthalate (PBN) resin, and a thermoplastic PBN resin is preferably used.

  Specific examples of the thermoplastic polyalkylene terephthalate resin include thermoplastic polyethylene terephthalate (PET) resin and thermoplastic polybutylene terephthalate (PBT) resin. Preferably, a thermoplastic PET resin is used. Use. Thermoplastic PET resin has the feature of being excellent in heat resistance, light resistance, wear resistance, and the like.

  Conductivity is adjusted by adding a conductive agent into the belt base 101. As such a conductive agent, those listed above for the resin layer 102 can be used as appropriate, and are not particularly limited. Moreover, the addition amount is preferably 0.01 to 30 parts by weight, more preferably about 0.1 to 20 parts by weight with respect to 100 parts by weight of the base resin. In the present invention, the conductivity of the entire belt is adjusted mainly by a conductive agent added to the belt base 101, and a conductive agent is added to the resin layer 102 for the purpose of supplementarily adjusting the conductivity.

  In addition to the above-described components, other functional components can be appropriately added to the belt base 101 within a range not impairing the effects of the present invention. For example, various fillers, coupling agents, and antioxidants can be added. An agent, a lubricant, a surface treatment agent, a pigment, an ultraviolet absorber, an antistatic agent, a dispersant, a neutralizing agent, a foaming agent, a crosslinking agent, and the like can be appropriately blended. Furthermore, you may color by adding a coloring agent.

The thickness of the conductive endless belt of the present invention is appropriately selected according to the form of the transfer / conveying belt or the intermediate transfer member. Preferably, the total thickness of the belt base 101 and the resin layer 102 is 50. Within the range of ~ 200 μm. The surface roughness is preferably 10 μm or less, particularly 6 μm or less, more preferably 3 μm or less in terms of JIS 10-point average roughness Rz. Furthermore, the volume resistivity is preferably adjusted to about 10 ² Ωcm to 10 ¹³ Ωcm by appropriately adding a conductive agent to the resin layer 102 and / or the belt base 101 as described above. .

  Further, the conductive endless belt of the present invention has a surface on the side in contact with a driving member such as the driving roller 9 or the driving roller 30 of FIG. 3 in the image forming apparatus of FIG. 2, as shown by a one-dot chain line in FIG. A fitting portion that fits with a fitting portion (not shown) formed on the drive member may be formed, and the conductive endless belt of the present invention is provided with such a fitting portion and drives this. Shifting in the width direction of the conductive endless belt can be prevented by running with a fitting portion (not shown) provided on the member.

  In this case, the fitting portion is not particularly limited, but, as shown in FIG. 1, it is formed as a ridge continuous along the circumferential direction (rotation direction) of the belt, and this is a driving member such as a driving roller. It is preferable to be fitted in a groove formed in the circumferential surface along the circumferential direction.

  In addition, although the example which provided one continuous protruding item | line as a fitting part was shown in Fig.1 (a), this fitting part has many convex parts along the circumferential direction (rotation direction) of a belt. They may be arranged in a row, or two or more fitting portions may be provided (FIG. 1 (b)), or may be provided at the center in the width direction of the belt. Further, a groove along the circumferential direction (rotating direction) of the belt is provided as a fitting portion instead of the convex strip shown in FIG. 1, and this is formed along the circumferential direction on the circumferential surface of the driving member such as the driving roller. You may make it make it fit with the protruding item | line which carried out.

  Further, as the image forming apparatus of the present invention using the conductive endless belt of the present invention, the tandem system shown in FIG. 2, the intermediate transfer system shown in FIG. 3, or the tandem intermediate transfer system shown in FIG. Although the thing can be illustrated, it is not limited to these. In the case of the apparatus shown in FIG. 3, a voltage can be appropriately applied from the power source 61 to the driving roller or driving gear for rotating the intermediate transfer member 20 of the present invention. The application conditions such as application of weighting alternating current can be selected as appropriate.

  Furthermore, in the method for producing a conductive endless belt according to the present invention, an ultraviolet curable resin or an electron beam curable resin and a conductive material are formed when the resin layer 102 is formed in a belt having a laminated structure including the belt base 101 and the resin layer 102. The method includes a step of applying a solvent-free coating solution containing an agent on the belt substrate 101 and curing it by irradiation with ultraviolet rays or electron beams. By using a method of applying a solvent-free coating solution, it is possible to save large-scale facilities and space that have been required in the past, and to suppress variations in film formation, thereby reducing the cost of the resin layer 102. It can be formed with high accuracy. In the production method of the present invention, the steps other than the step of forming the resin layer 102 are not particularly limited. For example, for the belt base 101, functions of the base resin and the conductive agent are performed by a biaxial kneader. It can be produced by kneading a resin composition composed of an active ingredient and extruding the obtained kneaded product using an annular die. Alternatively, a powder coating method such as electrostatic coating, a dip method, or a centrifugal casting method can also be suitably employed.

EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example, this invention is not restrict | limited to the following Example.
Examples 1-5 and Comparative Examples 1-4
Conductive endless belts of the examples and comparative examples were prepared according to the formulations shown in Tables 6 and 7 below. Specifically, first, each compounding component of the belt base shown in each table is melt-kneaded by a biaxial kneader, and the obtained kneaded material is extruded using an annular die, thereby obtaining an inner diameter of 220 mm, a thickness. A belt substrate 101 having a thickness of 100 μm and a width of 250 mm was produced. Thereafter, a solvent-free coating solution prepared by using the compounding materials shown in Tables 6 and 7 on the belt substrate 101, using a roll coater, the film thickness after drying is shown in Tables 8 and 9 below, respectively. The conductive endless belt 100 was obtained by coating so as to satisfy the values shown in FIG. Here, when ultraviolet rays are used, irradiation is performed with an illuminance of 400 mW and an integrated light quantity of 1000 mJ / cm ² using a UNICURE UVH-0252C apparatus manufactured by USHIO INC. While rotating the belt 100 after coating. In the case of using an electron beam, while the belt 100 after coating is similarly rotated, the roller is rotated using a Min-EB device manufactured by Ushio Electric Co., Ltd. Irradiation was performed under the conditions of a tube current of 300 μA, an irradiation distance of 100 mm, a nitrogen atmosphere of 760 mmTorr, and an irradiation time of 1 minute, and the coating film of the resin layer was cured. In Comparative Examples 1 and 2, the resin layer 102 was not provided.
As described above, a conductive endless belt 100 was obtained.

The universal hardness of each belt is a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) under the following measurement conditions using an ultra-small hardness meter H-100V manufactured by Fischer (Fischer). Thus, it is a value measured at a position inside by 5 μm from the outermost surface.
Indenter: Square pyramidal diamond with a face angle of 136 ° Maximum load: 100 mN / mm ²

＊１）ＰＡ１２：宇部興産（株）製、商品名：３０２４Ｕ
＊２）ＰＢＮ：帝人化成（株）製、商品名 ＴＱＢ−ＯＴ
＊３）ＰＥＴ：ユニチカ（株）製、商品名 ＳＡ−１２０６
＊４）カーボンブラック：電気化学工業（株）製、商品名 電化ブラック
＊５）ベース樹脂：
（１）ウレタンアクリレートオリゴマー、日本合成化学（株）製、型番 ＵＦ８００１（ＵＶ硬化の場合）
（２）ウレタンアクリレートオリゴマー、新中村化学（株）製、型番 ＵＡ−ＮＤＰ（ＥＢ硬化の場合）
＊６）反応性希釈剤：メトキシトリエチレングリコールアクリレート、共栄社化学（株）製、型番 ＭＴＧ−Ａ
＊７）重合開始剤：
（１）アシルフォスフィンオキサイド、チバスペシャリティケミカルズ社製、型番 ＩＲＧＡＣＵＲＥ８１９（最大吸収波長：４３０ｎｍ）
（２）α−ヒドロキシアセトフェノン、チバスペシャリティケミカルズ社製、型番 ＩＲＧＡＣＵＲＥ１８４（最大吸収波長：３００ｎｍ）
＊８）導電剤：
（１）カーボンブラック、商品名 ケッチェンＥＣ（カーボン系導電剤）
（２）過塩素酸ナトリウム（イオン系導電剤）

* 1) PA12: Ube Industries, Ltd., trade name: 3024U
* 2) PBN: manufactured by Teijin Chemicals Ltd., trade name: TQB-OT
* 3) PET: Unitika Co., Ltd., trade name SA-1206
* 4) Carbon black: manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Electric Black * 5) Base resin:
(1) Urethane acrylate oligomer, manufactured by Nippon Synthetic Chemical Co., Ltd., model number UF8001 (in case of UV curing)
(2) Urethane acrylate oligomer, manufactured by Shin-Nakamura Chemical Co., Ltd., model number UA-NDP (for EB curing)
* 6) Reactive diluent: Methoxytriethylene glycol acrylate, manufactured by Kyoeisha Chemical Co., Ltd., model number MTG-A
* 7) Polymerization initiator:
(1) Acylphosphine oxide, manufactured by Ciba Specialty Chemicals, model number IRGACURE819 (maximum absorption wavelength: 430 nm)
(2) α-hydroxyacetophenone, manufactured by Ciba Specialty Chemicals, model number IRGACURE184 (maximum absorption wavelength: 300 nm)
* 8) Conductive agent:
(1) Carbon black, trade name Ketjen EC (carbon-based conductive agent)
(2) Sodium perchlorate (ionic conductive agent)

About the electroconductive endless belt obtained in the said Examples 1-5 and Comparative Examples 1-4, each measurement was performed according to the following procedures.
<Measurement of volume resistivity>
The specific volume resistivity of the belt at a measurement voltage of 100 V was measured at 23 ° C. and 50% relative humidity by using a measurement chamber made of ADVANTEST with a resistance chamber R8340A connected to a sample chamber R12704A. did. Moreover, the volume resistance of the resin layer was calculated | required by apply | coating a coating liquid on a copper plate, hardening a coating film, and measuring the resistance between a copper plate and a measurement electrode.

<Image characteristics>
Each belt was mounted on a tandem type image forming apparatus using the transfer conveyance belt shown in FIG. 2, and the image characteristics after initial printing and after printing 100,000 sheets were evaluated.
These measurement results are shown in Tables 8 and 9 below.

＊９）比較例１、２のユニバーサル硬度は、ベルト基体についての測定値である。

* 9) The universal hardness of Comparative Examples 1 and 2 is a measured value for the belt substrate.

It is width direction sectional drawing of the electroconductive endless belt which concerns on one embodiment of this invention. 1 is a schematic diagram illustrating a tandem type image forming apparatus using a transfer conveyance belt as an example of an image forming apparatus of the present invention. FIG. 6 is a schematic view showing an intermediate transfer device using an intermediate transfer member as another example of the image forming apparatus of the present invention. FIG. 5 is a schematic view showing a tandem intermediate transfer device using a tandem intermediate transfer member as another example of the image forming apparatus of the present invention.

Explanation of symbols

1, 11, 52a to 52d Photosensitive drums 2 and 7 Charging roll 3 Developing roll 4 Developing blade 5 Toner supply roll 6 Cleaning blade 8 Static eliminating roll 9, 30, 55 Driving roller (driving member)
DESCRIPTION OF SYMBOLS 10 Transfer conveyance belt 12 Primary charger 13 Image exposure 14, 35 Cleaning device 19 Paper feed cassette 20 Intermediate transfer member 25 Transfer roller 26, 53 Recording medium 29, 61 Power supply 41, 42, 43, 44 Developer 50 Tandem intermediate transfer member 54a to 54d First developing portion to fourth developing portion 56 Recording medium feeding roller 57 Recording medium feeding device 58 Fixing device 59 Power supply device (voltage applying means)

Claims (9)

Conductive endless belt for tandem transfer and conveyance, in which a recording medium held by electrostatic adsorption is circulated and driven by a driving member, conveyed to four types of image forming bodies, and each toner image is sequentially transferred to the recording medium. In
The resin layer is provided on the belt substrate, and the universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) is 3 N / mm ² or less at a position 5 μm inside from the outermost surface. A conductive endless belt. The toner image formed between the image forming body and the recording medium is circulated and driven by a driving member, and the toner image formed on the surface of the image forming body is once transferred and held on the surface of the image forming body and transferred to the recording medium. In the conductive endless belt for the intermediate transfer member
The resin layer is provided on the belt substrate, and the universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) is 3 N / mm ² or less at a position 5 μm inside from the outermost surface. A conductive endless belt. Arranged between the four types of image forming bodies and the recording medium, and circulated and driven by a driving member, and sequentially transferring and holding the toner images formed on the surfaces of the four types of image forming bodies on the surface of the recording medium. In a conductive endless belt for a tandem intermediate transfer member that transfers this to a recording medium,
The resin layer is provided on the belt substrate, and the universal hardness under the measurement condition of a constant load application speed of 100 (mN / mm ² ) / 60 (seconds) is 3 N / mm ² or less at a position 5 μm inside from the outermost surface. A conductive endless belt.   The conductive endless belt according to claim 1, wherein the resin layer contains a conductive agent.   The conductive endless belt according to any one of claims 1 to 4, wherein the resin layer contains an ultraviolet curable resin or an electron beam curable resin as a main component. The electroconductive endless belt as claimed in any one of claims 1 to 5 universal hardness is in the range of 0.1~3N / mm ^2.   The conductive endless belt according to any one of claims 1 to 6, wherein the resin layer has a thickness in a range of 1 to 30 µm.   It is a manufacturing method of the electroconductive endless belt as described in any one of Claims 1-7, Comprising: The said solvent-free coating liquid containing the said ultraviolet curable resin or electron beam curable resin, and a electrically conductive agent, A method for producing a conductive endless belt, comprising: coating on a belt substrate, and curing the coating liquid after the coating by ultraviolet or electron beam irradiation to form the resin layer. An image forming apparatus comprising the conductive endless belt according to claim 1.

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