JP4889009B2 - Endless belt manufacturing method and image forming apparatus - Google Patents

Description

The present invention relates to an endless belt manufacturing method and an image forming apparatus, and more particularly to an endless belt manufacturing method capable of forming a high-quality image over a long period of time and an image forming apparatus including the endless belt.

  In an electrophotographic image forming apparatus, an endless belt formed of a thermoplastic resin or the like is used instead of or in addition to a metal drum body or an elastic roller. Examples of such endless belts include a transfer belt, an intermediate transfer belt, a transfer conveyance belt, a conveyance belt, a fixing belt, and a development belt.

As such an endless belt, for example, “obtained by cutting a tubular film of polycarbonate blended with conductive carbon into a predetermined length in a direction perpendicular to the axial direction, the surface electric resistance of each part of the film is 10 ^A seamless semiconductive belt characterized in that it is in the range of ⁵ to 10 ¹³ Ω / □ and the ratio of the minimum value to the maximum value of the surface electrical resistance is in the range of 0.01 or more. (See Patent Document 1).

  However, the endless belt attached to the image forming apparatus is usually stretched around a plurality of support rollers, and always travels at a high speed while being repeatedly applied and stopped on an endless track in a tensioned state. Therefore, in order to clearly distinguish the endless belt from both ends in the width direction (in the present invention, the end in the circumferential direction of the endless belt (although there is actually no end in the circumferential direction)) Are particularly easily damaged, and a high-quality image may not be formed.

  As an endless belt capable of preventing side damage to some extent, for example, “meandering prevention characterized by comprising meandering prevention guides formed of hot-melt binder resin along the moving direction at both ends of the belt body An endless belt with a guide ”(see Patent Document 2). This endless belt can prevent unnecessary meandering movement to some extent, but it uses a Teflon (registered trademark) sheet cut out in a long and narrow shape to prevent linear meandering along the direction of belt movement. Since guides (sometimes referred to as guide members) are formed on both ends of the endless belt, that is, on both side surfaces, damage on both side surfaces can be suppressed to some extent.

  However, since the meandering prevention guide as the guide member is formed at both ends of the belt body by the hot melt binder resin, the guide member is attached to the image forming apparatus and travels at high speed on an endless track, or the image forming apparatus. When the internal environment changes, the meandering prevention guide may be deformed or peeled off from the endless belt, particularly when it is mounted on an image forming apparatus having a recent high speed and / or long life. If the endless belt is run in such a state, various running troubles occur or meandering runs occur, and again, a high-quality image may not be formed. Further, it is difficult to accurately form meander prevention guides at both ends of the endless belt so as to prevent unnecessary meandering movement in the endless belt. Therefore, the manufacturability of the endless belt is low and the production cost is increased. Since the endless belt has meandering prevention guides formed at both ends thereof, problems such as deterioration in maintenance workability may occur.

  In addition, as an endless belt made of a thin film metal, “the opposite ends of the photosensitive member for an image forming apparatus formed by using a nickel-made seamless belt having a film thickness of 20 to 40 μm formed by electrocasting as a base are formed by upper and lower opposing roller blade edges. Cut to the desired width, chamfer each part of the outer periphery of the cut surface with a soft abrasive paper disc of No. 800-1500, remove the step formed on the cut surface without losing all the chamfered shape, Patent Document 3 discloses a “seamless belt photoreceptor for image forming apparatus” characterized in that the roughness is 5 μm or less.

  Since the seamless belt photoreceptor for image forming apparatus is made of thin film nickel, the strength is inherently strong, and therefore the roughness of the end face is set to 5 μm or less in order to prevent cracks from the end face cutting step. However, although there are various methods for measuring roughness even if it is simply referred to as “roughness of a certain surface”, Patent Document 3 describes a method for measuring roughness of an end surface. In addition, the specific end surface roughness is not described in the examples.

JP-A-3-89357 JP 59-230950 A JP 2004-86083 A

An object of the present invention is to provide a method of manufacturing an endless belt capable of forming a high-quality image over a long period of time, and an image forming apparatus including the endless belt.

As means for solving the problems,
1 is an endless belt manufacturing method for manufacturing an endless belt having a side surface having a ten-point average roughness Rz of 1.20 μm or less and an average interval Sm of unevenness of 10.0 μm or less. A molding step of centrifugally molding a resin composition containing a resin, a primary solvent removing step of removing a solvent contained in the layer of the resin composition developed by centrifugal molding, and an obtained film-like molded body A secondary solvent removing step of heating the superheated steam at 200 to 260 ° C. for 30 to 60 minutes to obtain an endless belt substrate having a solvent residual amount of 0.04 to 0.30% by mass; A method for producing an endless belt having a cutting step of cutting a side end portion and not performing surface processing of a cut surface ;
Claim 2 is the method for producing an endless belt according to claim 1, wherein the solvent is a solvent used in a polycondensation reaction for synthesizing an aromatic polyamideimide resin .
Claim 3 is a method for producing an endless belt according to claim 1 or 2 , wherein the primary solvent removing step is a step of passing hot air of 40 to 150 ° C into the layer of the resin composition .
A fourth aspect of the present invention is the endless belt manufacturing method according to any one of the first to third aspects, wherein the ten-point average roughness Rz is 1.20 μm or less and the average interval Sm of the unevenness is 10.0 μm or less. The image forming apparatus includes an endless belt having a side surface .

An endless belt manufactured by the method of manufacturing an endless belt according to the present invention (sometimes referred to as an endless belt according to the present invention) has a ten-point average roughness Rz having a side surface of 1.20 μm or less and 10.0 μm or less. Therefore, it is mounted on an image forming apparatus having a high speed and / or a long service life in recent years, and always runs on an endless track with tension applied. Even when the vehicle is run at a high speed while being repeatedly stopped, and even when the side crack prevention means represented by the guide member or the like is not particularly provided on the side surface, the side surface is not cracked or broken for a long time. It can be effectively prevented over a long period of time and exhibits high durability. Therefore, according to this invention, the manufacturing method of the endless belt which can form a high quality image over a long period of time can be provided.

  Further, according to the present invention, since the endless belt according to the present invention is provided, an image forming apparatus capable of forming a high-quality image over a long period of time can be provided.

  Hereinafter, an endless belt as an example of the present invention will be described with reference to the drawings. As shown in FIG. 1, the endless belt 1 is formed in a ring shape from a resin composition to be described later, and has a side surface 2 having characteristics to be described later. As shown in FIG. 1, the endless belt 1 has a single layer structure, but may have a multilayer structure in which two or more layers are laminated. The thickness of the endless belt 1 is not particularly limited, but usually, for example, preferably 0.03 to 1 mm, more preferably 0.05 to 0.2 mm, and about 0.07 to 0.14 mm. Is particularly preferred. If the thickness of the endless belt 1 is less than 0.03 mm, the mechanical strength of the endless belt 1 may decrease. May be inferior. The width and inner diameter of the endless belt 1 are set to a desired width according to the use of the endless belt 1, that is, the position (component) disposed in the image forming apparatus, the interval between a plurality of stretched rollers, and the like. And it is arbitrarily set so that it may become an inner peripheral diameter. For example, the endless belt 1 has a width of 200 to 350 mm and an inner peripheral diameter of 200 to 2,500 mm.

  The endless belt 1 has a ten-point average roughness Rz on the side surface 2 of 1.20 μm or less. If the side surface 2 of the endless belt 1 has a ten-point average roughness Rz of 1.20 μm or less, the endless belt 1 is mounted on an image forming apparatus having a high speed and / or a long life, and is always tensioned. Even when the vehicle is run at a high speed while being repeatedly run and stopped on an endless track, or when the side face 2 is not particularly provided with side crack prevention means represented by a guide member or the like, the endless belt It is possible to effectively prevent the side surface 2 of 1 from being cracked or broken over a long period of time, and exhibit high durability. The ten-point average roughness Rz is more preferably 0.80 μm or less, and particularly preferably 0.30 μm or less in terms of exhibiting even higher durability. The lower limit value of the ten-point average roughness Rz is preferably as small as possible, but in the endless belt 1, it is usually preferably 0.01 μm, for example.

The ten-point average roughness Rz is obtained by cutting any plurality of locations (for example, three locations) of the side surface 2 of the endless belt 1 as test specimens, and the side surfaces of the cut specimens are examined with a microscope (for example, an ultra-deep color 3D shape). In an arbitrary region having an area of 300 μm ² on the observation surface, the reference length is 250 μm, according to JIS B 0601-1994, observed with a measuring microscope, trade name “VK-9500GII”, manufactured by KEYENCE Inc. It can be obtained by measuring the ten-point average roughness under the condition of an evaluation length of 1250 μm and arithmetically averaging them.

  The crack or breakage of the side surface 2 of the endless belt 1 is caused by a step between a cutting start point and a cutting end point formed on the cut surface when an endless belt base to be described later is cut into an endless belt having a desired size. In addition, it also occurs from other cut surfaces. Therefore, in the present invention, a plurality of locations on the side surface 2 of the endless belt 1 are measured points. Thereby, not only the crack and breakage from the side surface due to the step, but also the crack and breakage from the side surface 2 where the step does not exist can be effectively prevented.

  The endless belt 1 has an average interval Sm of unevenness on the side surface 2 of 10.0 μm or less. When the side surface 2 of the endless belt 1 has an average interval Sm of unevenness of 10.0 μm or less, the endless belt 1 is mounted on an image forming apparatus having a high speed and / or a long life, and tension is always applied. Even when the endless belt 1 is run at a high speed while being repeatedly run and stopped on the endless track, or when the side crack prevention means represented by a guide member or the like is not particularly provided on the side, It is possible to effectively prevent the side surface 2 from being cracked or broken over a long period of time and exhibit high durability. The average interval Sm between the concaves and convexes is more preferably 7.0 μm or less, and particularly preferably 3.0 μm or less, from the viewpoint of even higher durability. The lower limit value of the average interval Sm of the unevenness is preferably as small as possible, but in the endless belt 1, it is usually preferably, for example, 1.0 μm.

The average interval Sm of the unevenness is the same as the ten-point average roughness Rz, in an arbitrary region having an area of 300 μm ² under the conditions of a reference length of 250 μm and an evaluation length of 1250 μm according to JIS B 0601-1994. It can be obtained by measuring the average interval of the irregularities and arithmetically averaging them.

  The endless belt 1 preferably has an arithmetic average roughness Ra on the side surface 2 of 0.25 μm or less. When the side surface 2 of the endless belt 1 has an arithmetic average roughness Ra of 0.25 μm or less, the endless belt 1 is attached to an image forming apparatus having a high speed and / or a long life and is always tensioned. Even when the endless belt 1 is run at a high speed while being repeatedly run and stopped on the endless track, or when the side crack prevention means represented by a guide member or the like is not particularly provided on the side, It is possible to more effectively prevent the side surface 2 from cracking or breaking over a long period of time, and to exhibit even higher durability. In view of particularly high durability, the arithmetic average roughness Ra is more preferably 0.15 μm or less, and particularly preferably 0.05 μm or less. The lower limit of the arithmetic average roughness Ra is preferably as small as possible. However, in the endless belt 1, it is usually preferably 0.01 μm, for example.

The arithmetic average roughness Ra is the same as the ten-point average roughness Rz, in an arbitrary region having an area of 300 μm ² , according to JIS B 0601-1994, with a cutoff value of 0.08 mm and an evaluation length of 0.00. It can be obtained by measuring the arithmetic average roughness under the condition of 4 mm and arithmetically averaging them.

The endless belt 1 usually preferably has a volume resistance value of 1 × 10 ⁹ to 1 × 10 ¹³ Ω · cm when electrical conductivity is required, and is preferably 1 × 10 ¹⁰ to 1 × 10 ¹² Ω · cm. Particularly preferred is cm. When the volume resistance value is within the above range, a high-quality image can be formed when the endless belt 1 is used in an image forming apparatus. The volume resistance value can be measured by a volume resistance measuring device (manufactured by Mitsubishi Chemical Corporation, trade name: Hiresta-UP, probe used: URS).

  The endless belt 1 is formed by molding a resin composition. The resin composition is preferably a resin composition having a certain level of strength and containing a single resin or a plurality of types of resins that are resistant to repeated deformation and is highly flexible, and is contained in such a resin composition. Examples of the resin used include polyester resins such as polyamideimide resin, polyimide resin, polyamide resin, aramid resin, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and cross-linked polyester resin. , Polysulfone resin, polyether sulfone resin, polyether ether ketone resin (PEEK), epoxy resin, melamine resin and the like. Among these, polyamideimide resin, polyimide resin, and polyamide resin are preferable, and polyamideimide resin is more preferable. In particular, aromatic polyamideimide resin has mechanical properties such as strength, flexibility, dimensional stability, and heat resistance. It is preferable in terms of excellent balance.

  The aromatic polyamideimide resin can be produced by a diisocyanate method in which a tricarboxylic acid anhydride and a diisocyanate compound are reacted, and is excellent in terms of availability of raw materials, reactivity, and a small amount of byproducts. In addition to the aromatic polyamideimide resin produced by the diisocyanate method, an aromatic polyamideimide resin produced using a diamine compound instead of the diisocyanate compound can be used as long as the polycondensation reaction can be suitably advanced. preferable. An aromatic polyamideimide resin obtained using a diamine compound has a high Young's modulus and is suitable as a resin contained in the resin composition forming the endless belt 1. Moreover, the aromatic polyamide-imide resin in which part of the tricarboxylic acid anhydride is replaced with tetracarboxylic dianhydride to increase the imide bond is excellent in moisture resistance. The aromatic polyamideimide resin can be easily synthesized by reacting in an appropriate solvent under normal pressure and at normal temperature or under heating.

  The tricarboxylic acid anhydride is preferably an aromatic tricarboxylic acid anhydride, such as trimellitic acid anhydride, 3,4,4′-diphenyl ether tricarboxylic acid anhydride, 3,4,4′-benzophenone tricarboxylic acid anhydride. 2,3,5-pyridinetricarboxylic acid anhydride, naphthalenetricarboxylic acid anhydride, and derivatives thereof. These acid anhydrides can be used singly or in combination of two or more.

  Examples of the tetracarboxylic dianhydride used in place of a part of the tricarboxylic acid anhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3, 3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2, 2'-bis (3,4-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) sulfonic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride Bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride, and derivatives thereof. These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

  Preferred examples of the diisocyanate compound include aromatic diisocyanate compounds. In addition, as the diisocyanate compound, an aliphatic diisocyanate compound and / or an alicyclic diisocyanate compound, or amines that are derivatives thereof can be used together with or in place of the aromatic diisocyanate compound.

  Examples of the aromatic diisocyanate compound include m-phenylene diisocyanate, p-phenylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 4,4′-diisocyanate diphenyl ether, 4,4′-diisocyanate diphenyl sulfone, and 4,4′-diisocyanate. Biphenyl, 3,3′-dimethyl-4,4′-diisocyanate biphenyl, 2,4-toluene diisocyanate, xylylene diisocyanate and the like can be mentioned. Diamines that are derivatives of these aromatic diisocyanate compounds can also be used as raw materials. Examples of the aliphatic diisocyanate compound include ethylene diisocyanate, propylene diisocyanate, and hexamethylene diisocyanate. Examples of the alicyclic diisocyanate compound include 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and the like. Among these diisocyanate compounds, considering the heat resistance, mechanical properties, solubility, and the like of the endless belt 1, 60% by mass or more, preferably 70% by mass or more of all the diisocyanate compounds used is diphenylmethane-4,4. It is preferable to use diamines that are '-diisocyanate, 2,4-toluene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate biphenyl, isophorone diisocyanate, or derivatives thereof. Further, considering the dimensional stability of the endless belt 1, 70% by mass or more of all diisocyanate compounds used may be diphenylmethane-4,4′-diisocyanate or its derivative 4,4′-diaminodiphenylmethane. preferable.

  As the solvent used in the polycondensation reaction for synthesizing the aromatic polyamideimide resin, a polar solvent is preferable in terms of solubility, and an aprotic polar solvent is particularly preferable in consideration of reactivity. Examples of aprotic polar solvents include N, N-dialkylamides, and examples of N, N-dialkylamides include N, N-dimethylformamide, N, N-dimethylacetamide, N, N- Examples include diethylformamide, N, N-diethylacetamide, and N, N-dimethylmethoxyacetamide. Further, as a polar solvent, N-methyl-2-pyrrolidone, pyridine, dimethyl sulfoxide, tetramethylene sulfone, dimethyltetramethylene sulfone, and the like are also preferable. These solvent can be used individually by 1 type or in mixture of 2 or more types.

  When the resin composition requires a certain degree of conductivity, such as a transfer / conveyance belt, for example, a conductivity imparting agent is added to form a conductive resin composition. The conductivity-imparting agent contained in the conductive resin composition is composed of various carbon blacks such as furnace black, acetylene black and ketjen black, graphite powder such as natural graphite, artificial graphite and expanded graphite, metal or alloy, etc. Examples include needle-like, spherical, plate-like, and irregular powders, ceramic powders, and various particles whose surfaces are metal-plated. Among these, carbon black is preferable in that the particle size, conductivity, affinity with resin, and the like are excellent in a balanced manner. In addition, the carbon black is more preferably an oxidized carbon black to which a carboxy group, a hydroxy group or the like has been added by an oxidation treatment in terms of improving the affinity with the resin, and an oxidized carbon black having a pH of 6 or less is also preferred. The conductivity-imparting agent is preferably spherical or indefinite, and its size is preferably about 0.01 to 10 μm.

  The addition amount of the conductivity-imparting agent may be appropriately adjusted depending on the conductivity and particle size of the conductivity-imparting agent, the conductivity required for the endless belt 1, and the like. It is preferable that it is 1-25 mass% with respect to the total mass of 100%, and it is more preferable that it is 5-20 mass%. When the addition amount of the conductivity imparting agent is less than 1% by mass, the developed conductivity may be small. On the other hand, when the addition amount of the conductivity imparting agent exceeds 25% by mass, the mechanical strength of the endless belt 1 is increased. May decrease. In order to disperse the conductivity-imparting agent in the resin, a known method can be appropriately selected. Examples of known methods include mixing rolls, pressure kneaders, extruders, three rolls, homogenizers, ball mills, pot mills, and the like. The mixing method using bead mill etc. is mentioned.

  The resin composition and the conductive resin composition may contain other components in addition to the resin or the resin and the conductivity-imparting agent as long as the object of the present invention is not impaired. Examples of other components include silicone compounds, fluorine organic compounds, coupling agents, lubricants, antioxidants, plasticizers, colorants, antistatic agents, anti-aging agents, reinforcing fillers, reaction aids, Examples include various additives such as reaction inhibitors, other resins, solvents, and the like.

  Next, a method for manufacturing the endless belt 1 according to the present invention will be described. In order to manufacture the endless belt 1, first, the resin composition is formed into an annular shape by a known forming method. For example, when a thermoplastic resin is selected as the resin contained in the resin composition forming the endless belt 1, when a thermosetting resin is selected as the resin by centrifugal molding, extrusion molding, injection molding, or the like The endless belt 1 can be formed by centrifugal molding, RIM molding, or the like. Among these molding methods, centrifugal molding is preferable in that it can be applied regardless of the material and is excellent in thickness accuracy.

  When the endless belt 1 is molded by centrifugal molding, the resin composition forming the endless belt 1 is preferably adjusted to have a viscosity at molding of 50,000 mPa · s or less. When the viscosity exceeds 50,000 mPa · s, it may be difficult to produce the endless belt 1 having a uniform thickness. The lower limit of the viscosity of the resin composition is not particularly limited, but is preferably 10 mPa · s or more. When the viscosity of the resin composition is out of the above range, the viscosity of the resin composition can be adjusted within the above range by adjusting the amount of the solvent added. As a solvent, the solvent used for the polycondensation reaction which synthesize | combines the said aromatic polyamideimide resin is mentioned.

  According to centrifugal molding, a resin composition that exhibits fluidity by containing a solvent is poured into a cylindrical mold, and the mold is rotated to form a resin composition layer on the inner peripheral surface of the mold by centrifugal force. The endless belt substrate is manufactured by uniformly spreading and drying and removing the solvent from the resin composition layer. Various metal pipes can be used for the mold. As a suitable mold, the inner peripheral surface of the mold is mirror-polished, and the inner peripheral surface that becomes the mirror surface is subjected to a release treatment with a release agent such as a fluororesin or a silicone resin, and the formed endless belt base is formed. Examples thereof include a metal tube that can be easily removed from the inner peripheral surface.

  When a polyamideimide resin is selected as the resin contained in the resin composition, in addition to the above-described centrifugal molding, a polyamic acid obtained by partially polymerizing a tricarboxylic acid anhydride and a diisocyanate compound, which are raw materials of the polyamideimide resin, is used. Is applied to the inner and outer peripheral surfaces of the mold by a dipping method, a centrifugal method, a coating method, etc., or is developed into a cylindrical shape by an appropriate method such as filling the casting mold with the polyamic acid solution. The developed layer is dried to form a belt shape, and the molded product is heat-treated to convert the polyamic acid to an imide and recover from the mold (Japanese Patent Laid-Open No. 61-95361, The endless belt 1 can also be manufactured according to Japanese Patent Application Laid-Open No. 64-22514 and Japanese Patent Application Laid-Open No. 3-180309.

  The solvent is removed from the resin composition layer developed on the inner peripheral surface of the mold to produce an endless belt substrate. Here, the solvent to be removed is a solvent contained in the layer of the resin composition developed on the inner peripheral surface of the mold. For example, in addition to the solvent used when adjusting the viscosity of the resin composition And a solvent used when synthesizing the aromatic polyamideimide resin. Examples of the treatment for removing the solvent from the resin composition layer developed on the inner peripheral surface of the mold include a heat treatment. To remove the solvent, the following primary solvent removal step and secondary solvent removal step are used. It is preferable to perform a solvent removal treatment consisting of

  In the primary solvent removal step, molding is performed while removing the solvent from the layer of the resin composition developed on the inner peripheral surface of the mold by rotating the mold, and the layer of the resin composition is made into a film-like molded body. In the primary solvent removal step, the solvent is removed by passing hot air of 40 to 150 ° C. through the mold for 5 to 60 minutes while rotating the mold. When the hot air temperature exceeds 150 ° C. and / or when the heating time exceeds 60 minutes, the molded film-like molded body may be oxidized.

  In the secondary solvent removing step, the film-like molded body molded in the primary solvent removing step is taken out from the centrifugal molding machine together with the mold, heated together with the mold to remove the solvent from the film-like molded body, To do. For example, when using a heater such as a hot air dryer or oven, the film-like molded body may be heated together with the mold at 200 to 300 ° C. for 1 to 3 hours, and when a superheated steam furnace is used. What is necessary is just to heat a film-form molded object for 30 to 60 minutes with 200-260 degreeC superheated steam with a metal mold | die.

  The endless belt substrate from which the solvent has been removed in this manner preferably has a solvent residual amount of 0.04 to 0.30% by mass. When the endless belt substrate has a solvent residual amount of 0.04 to 0.30 mass%, the ten-point average roughness on the side surface of the endless belt 1 is obtained by simply cutting the endless belt substrate with a cutting device. Rz and the average interval Sm of the irregularities, preferably the arithmetic average roughness Ra can be adjusted within the range. The solvent residual amount of the endless belt substrate is 0.10 to 0.30 in that the ten-point average roughness Rz, the average interval Sm of unevenness, and the arithmetic average roughness Ra can be reliably adjusted to the above ranges. It is more preferable that it is mass%, and it is especially preferable that it is 0.15-0.25 mass%. The amount of residual solvent in the endless belt substrate is determined by immersing a sample cut out from the endless belt substrate in ethanol for a predetermined time to extract the residual solvent in the endless belt substrate, and gas chromatography-mass spectrometry (GC-MS) Can be measured.

  After making an endless belt base having a desired solvent residual amount in this way, the endless belt base is taken out of the mold and allowed to cool. When the endless belt base is allowed to cool together with the mold, the endless belt base can be removed due to the difference in thermal expansion coefficient between the mold and the endless belt base. Both end portions of the removed cylindrical endless belt base are removed and cut into a predetermined width, whereby the endless belt 1 is manufactured. The cutting machine that cuts the endless belt substrate may be an apparatus that can cut the endless belt substrate so that the cutting start point and the cutting end point of the endless belt substrate substantially coincide with each other.

  Thus, in the secondary solvent removal step, if the removal conditions are adjusted to the above-mentioned conditions, the cut surface (side surface 2 of the endless belt 1) can be cut into a desired ten-point average roughness simply by cutting the endless belt substrate. Although it can be a side surface having Rz, average interval Sm of irregularities, and if necessary, an arithmetic average roughness Ra, if desired, by applying surface processing means such as polishing, grinding and cutting to the cut surface, The side surface 2 can also be obtained by adjusting the point average roughness Rz and the average interval Sm of unevenness, preferably the arithmetic average roughness Ra within the above range. The surface processing means used at this time is not particularly limited, and examples thereof include a polishing film (trade name “wrapping film sheet”, manufactured by Sumitomo 3M Co., Ltd.).

  The endless belt 1 manufactured in this manner has a 10-point average roughness Rz whose side surface 2 is 1.20 μm or less, an average interval Sm of unevenness of 10.0 μm or less, and preferably an arithmetic average of 0.25 μm or less. Since the surface has a roughness Ra, it is mounted on an image forming apparatus that has recently been increased in speed and / or service life, and can always run and stop on an endless track in a state where tension is applied. Even if it is run at a high speed while being repeated, and even if it is not particularly provided with side crack prevention means represented by a guide member or the like, it is effective over a long period that the side surface 2 is cracked or broken. Can be prevented and high durability is exhibited. Therefore, the endless belt 1 can sufficiently contribute to forming a high-quality image over a long period of time.

  Further, since the endless belt 1 is not formed with meandering prevention means such as a guide member in the vicinity of the side surface 2, as described above, its manufacturability is high and the production cost can be reduced. Maintenance workability of the endless belt 1 attached to the forming apparatus is also high.

  The endless belt 1 may be variously modified as long as the object of the present invention can be achieved. For example, the endless belt 1 is not a guide member that can prevent cracks and / or breakage from the end surface 2 thereof. Means for preventing meandering may be provided. As such meandering prevention means, for example, (1) as shown in FIG. 2, a means for bringing one side surface 2A of the endless belt 1 into contact with a guide surface formed on the support roller 3 or the like, more specifically, (2) means for running the endless belt 1 while maintaining the state in which the side surface 2A of the endless belt 1 is in contact with the annular positioning flange 4 provided on the support roller 3, as shown in FIG. A plurality of holes 5 arranged in the circumferential direction of the endless belt 1 are provided in the vicinity of one side surface 2A of the endless belt 1, and a convex body 6 that can be inserted into the hole 5 is provided in the support roller 3, so that the convex shape Examples include means for causing the body 6 to lock the hole 5 and causing the endless belt 1 to travel. If the endless belt 1 is provided with such meandering prevention means, the endless belt 1 can be effectively prevented from meandering and / or wavy running, and as a result, it is possible to achieve higher quality and higher performance over a long period of time. A resolution image can be formed.

  In the meandering preventing means (1) and (2), the positioning flange 4, the hole 5 and the convex body 6 are formed on one end portion of the support roller 3 and one side surface 2A of the endless belt 1. In the meandering preventing means, the positioning flange, the hole and the convex body may be formed on both end portions of the support roller and on both side surfaces of the endless belt.

  Next, an example of an image forming apparatus provided with the endless belt 1 according to the present invention (hereinafter sometimes referred to as an image forming apparatus according to the present invention) will be described with reference to FIG. The endless belt 1 is stretched around a plurality of support rollers 5 as a transfer conveyance belt 30.

  As shown in FIG. 4, the image forming apparatus 10 is a tandem type color image forming apparatus in which a plurality of image carriers 11 provided in each color developing unit are arranged in series on a transfer conveyance belt 30. Developing units BK, C, M, and Y are arranged in series on the transfer conveyance belt 30. Each of these developing units is provided with a rotatable image carrier 11 on which an electrostatic latent image is formed, and a charge that is provided in contact with the image carrier 11 or at a predetermined interval to charge the image carrier 11. A means 12; an exposure means 13 for forming an electrostatic latent image on the image carrier 11; and an abutting contact with the image carrier 11 or at a predetermined interval. The developer 22 is supplied to the carrier 11 with a constant layer thickness, and is provided so as to be in pressure contact with the developing means 20 for developing the electrostatic latent image via the transfer conveyance belt 30 below the image carrier 11. Transfer means 14 for transferring the electrostatic latent image developed on the recording medium 16 conveyed by the transfer conveyance belt 30 from the carrier 11, developer 22 remaining on the image carrier 11 without being transferred to the recording medium 16, and the like And a cleaning means 15 for removing water.

  As the image carrier 11, the charging unit 12, the exposure unit 13, the transfer unit 14, and the cleaning unit 15, conventionally known ones can be appropriately selected and used. For example, the image carrier 11 may be, for example, a cylindrical body or a belt body provided with a photosensitive layer formed of organic, amorphous silicon, Se-based alloy, or the like. Examples of the transfer unit 14 include a contact-type charger, a scorotron charger, and a corotron charger. The exposure unit 13 includes a light source such as a semiconductor laser beam and a light-emitting diode beam, or an optical device including a light source and a polygon mirror. Examples of the cleaning unit 17 include a blade and a roller.

  As shown in FIG. 4, the developing means 20 has an opening at a position facing the image carrier 11, and a housing 21 for storing the developer 22 and an image bearing at the opening of the housing 21. A rotatable developer carrier 23 which is provided in contact with the body 11 or at a predetermined interval and supplies the developer 22 with a constant layer thickness to the image carrier 11; and a developer carrier And a developer regulating member 24 that contacts the developer carrying member 23 to regulate the layer thickness of the developer 22 and charges the developer 22 by frictional charging.

  The developer 22 may be a dry developer or a wet developer, and may be a non-magnetic developer or a magnetic developer as long as it can be charged by friction and can be fixed to the recording medium 16. Each of the developing units BK, C, M, and Y contains a black developer, a cyan developer, a magenta developer, and a yellow developer in the housing 21. The developer carrier 23 and the developer regulating member 24 may be any conventionally known developer carrier and developer regulating member. For example, the developer carrier 23 may be conductive or semiconductive. Examples thereof include a roller having a resin layer, and the developer regulating member 24 may be a resin blade or a metal blade.

  As shown in FIG. 4, the image carrier 11 and the transfer unit 14 in the developing units BK, C, M, and Y are in contact with each other via a transfer conveyance belt 30 stretched between two support rollers 5. ing. The recording body 16 is transported by the transfer transport belt 30 so as to pass through the contact portion between the image carrier 11 and the transfer unit 14. The transfer conveyance belt 30 conveys the recording medium 16 and transfers the developed electrostatic latent image onto the image carrier 11 in cooperation with the transfer means 14.

  As shown in FIG. 4, at the bottom of the image forming apparatus 10, a cassette 31 is provided which is a recording body 16 in which a plurality of transfer papers are stacked and accommodated, and the transfer paper in the cassette 31 is a paper feed roller. The sheet is fed out one by one by a process or the like and conveyed onto the transfer conveyance belt 30.

  As shown in FIG. 4, a fixing unit 32 that fixes the developer 22 (electrostatic latent image) transferred to the recording body 16 is disposed downstream in the conveyance direction of the recording body 16 in the image forming apparatus 10. . The fixing means 32 may be a conventionally known fixing means, and for example, a heat roller fixing device such as a heat roller fixing device or an oven fixing device, a pressure fixing device, and a fixing device including a fixing belt may be used. it can.

  The image forming apparatus 10 operates as follows. First, the image carrier 11 of the developing unit BK is uniformly charged by the charging unit 12, and the image is exposed by the exposure unit 13 to form an electrostatic latent image on the surface of the image carrier 11. On the other hand, in the developing unit 20, the black developer 22 is regulated to a desired layer thickness by the developer carrier 23 and the developer regulating member 24 and is charged as desired. Then, the black developer 22 is supplied from the developer carrier 23 to the image carrier 11, and the electrostatic latent image formed on the image carrier 11 is developed and visualized as a developer image. Next, the developer image is transferred onto the recording medium 16 conveyed by the transfer conveyance belt 30 between the image carrier 11 and the transfer unit 14. In this way, the developer image is visualized as a black image on the recording paper 16.

  Next, similarly to the developing unit BK, the cyan image, the magenta image, and the yellow image are superimposed on the recording paper 16 in which the developer image is visualized as a black image by the developing units C, M, and Y, respectively. The image is visualized. At this time, particularly when the endless belt 1 is provided with the meandering prevention means, a cyan image, a magenta image, and a yellow image are superimposed on the black image visualized on the recording paper 16 at an accurate position. As a result, color unevenness and image misalignment can be effectively prevented over a long period of time, and a higher quality image can be formed.

  Next, the recording body 16 in which the color image is visualized is conveyed to the fixing unit 32, and the color image is fixed on the recording body 16 as a permanent image by the fixing unit 32. In this way, a color image can be formed on the recording medium 16.

  According to the image forming apparatus 10, since the endless belt 1 is used as the transfer conveyance belt 30, even when the image forming apparatus 10 is an image forming apparatus having a recent high speed and / or long life, Even when the endless belt 1 is always run at a high speed while being repeatedly run and stopped on an endless track in a state where tension is applied, a side crack prevention means represented by a guide member or the like is further provided on the side face. However, the image forming apparatus 10 can form a high-quality image over a long period of time.

  The endless belt 1 according to the present invention has a transfer belt (also referred to as a photosensitive belt) that plays the same role as the image carrier 11 and a developer image visualized by the image carrier 11 once. Transfer (primary transfer), and then transfer (secondary transfer) to the recording medium 16 to transfer an image to the recording medium, an intermediate transfer belt used as a primary recording medium, and conveyance for conveying the recording medium 16 Even if incorporated in the image forming apparatus 10 as a developing belt that plays the same role as the belt, the fixing belt used in the fixing device, and the developer carrier, the image forming apparatus 10 Quality images can be formed over a long period of time.

  The image forming apparatus 10 is an electrophotographic image forming apparatus. However, in the present invention, the image forming apparatus 10 is not limited to the electrophotographic system, and is, for example, an electrostatic image forming apparatus. Also good. Further, the image forming apparatus 10 is a tandem color image forming apparatus in which a plurality of image carriers each having a developing unit for each color are arranged in series on the transfer conveyance belt 30, but the image forming apparatus is a single image forming apparatus. Or a four-cycle color image forming apparatus that sequentially repeats primary transfer of a developer image carried on an image carrier onto an endless belt. The image forming apparatus 10 is an image forming apparatus such as a copying machine, a facsimile machine, or a printer.

Example 1
In a reaction vessel, N-methyl-2-pyrrolidone, trimellitic anhydride, an equivalent amount of diphenylmethane-4,4′-diisocyanate, and reaction raw materials (trimellitic anhydride and diphenylmethane-4,4′- 2 mol% of potassium fluoride (catalyst) is added to the total number of moles of diisocyanate), and the temperature is raised from room temperature to 150 ° C. over 30 minutes with stirring. (Substantially fully ring-closed polyamideimide) A 20% by mass aromatic polyamideimide solution was obtained. N-methyl-2-pyrrolidone was further added to this solution to prepare a polyamideimide solution having a reactant concentration of 15% by mass. To the obtained polyamideimide solution, an oxidation-treated carbon black (trade name “Printex 150T”, manufactured by Degussa, pH 5.8, volatile content 10.0%) was added to the polyamideimide solution and the oxidation-treated carbon black in a total of 100 mass. The conductive resin composition was prepared by adding at a ratio of 16% by mass with respect to% and mixing and dispersing in a pot mill for 24 hours. The mold used for molding has an inner diameter of 226 mm, an outer diameter of 246 mm, and a length of 400 mm, and the inner surface of the mold is mirror-polished by polishing. Next, ring-shaped lids (inner diameter: 170 mm, outer diameter: 250 mm) are fitted into the openings at both ends of the mold, the mold is closed, and the conductive resin composition is rotated at a speed of 1,000 rpm. 190 g was injected into the inner periphery of the mold. Next, the mold was rotated at the same speed for 30 minutes to uniformly spread the layer of the conductive resin composition on the inner peripheral surface of the mold. Next, while rotating the mold at the same speed, the temperature around the mold was maintained at 80 ° C. with a hot air dryer, and this state was maintained for 30 minutes to form a film-shaped molded body. Thereafter, the rotation of the mold was stopped, the film-shaped molded body was taken out from the centrifugal molding machine together with the mold, subjected to superheated steam treatment in a superheated steam furnace adjusted to 250 ° C. for 50 minutes, allowed to cool at room temperature, and endless. A belt substrate was obtained. When the endless belt base is cooled together with the mold, the endless belt base is peeled off due to the difference in thermal expansion coefficient between the mold and the endless belt base. Three test pieces each having a 50 mg piece were cut out from the peeled endless belt substrate, and these test pieces were each immersed in 20 mL of ethanol at 60 ° C. for 24 hours. The residual amount of N-methyl-2-pyrrolidone in the ethanol solution was measured by gas chromatography-mass spectrometry (GC-MS). In the measurement, the amount of N-methyl-2-pyrrolidone in a standard solution containing N-methyl-2-pyrrolidone 100 ppm and 1000 ppm in ethanol was measured in advance to prepare a calibration curve. The arithmetic average value of the measured residual amount was defined as the solvent residual amount of the endless belt substrate. As a result, the residual solvent amount of the endless belt substrate was 0.20% by mass.

  Further, both end portions of the produced belt base were cut and cut into a size having a circumference of about 226 mm, a width of 240 mm, and a thickness of 100 μm to produce an endless belt 1A.

(Example 2)
The film-like molded body produced in the same manner as in Example 1 was replaced with a superheated steam furnace adjusted to 250 ° C. instead of a superheated steam treatment for 50 minutes in a superheated steam furnace adjusted to 250 ° C. for each mold. An endless belt 1B was produced in the same manner as in Example 1 except that the superheated steam treatment was performed for a minute. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.14% by mass.
(Example 3)
The film-like molded body produced in the same manner as in Example 1 was replaced with a superheated steam furnace adjusted to 250 ° C. instead of a superheated steam treatment for 50 minutes in a superheated steam furnace adjusted to 250 ° C. for each mold. 1 C of endless belts were produced like Example 1 except having performed the superheated steam treatment for minutes. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.05% by mass.
Example 4
The film-like molded body produced in the same manner as in Example 1 was replaced with a superheated steam furnace adjusted to 250 ° C. in place of the superheated steam treatment for 50 minutes in the superheated steam furnace adjusted to 250 ° C. for each mold. An endless belt 1D was produced in the same manner as in Example 1 except that the superheated steam treatment was performed for a minute. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.28% by mass.
(Example 5)
The film-like molded body produced in the same manner as in Example 1 was replaced by a superheated steam furnace adjusted to 255 ° C. instead of a superheated steam treatment for 50 minutes in a superheated steam furnace adjusted to 250 ° C. for each mold. An endless belt 1E was produced in the same manner as in Example 1 except that the superheated steam treatment was performed for a minute. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.04% by mass.
(Reference Example 1)
Both ends of the belt substrate produced in the same manner as in Example 1 were cut, cut into a size of a circumference of about 226 mm, a width of 245 mm, and a thickness of 100 μm. The endless belt 1F was manufactured by polishing using “wrapping film sheet 0.3MIC A0”, manufactured by Sumitomo 3M Co., Ltd., abrasive grain size 0.3 μm).

(Comparative Example 1)
A film-like molded body produced in the same manner as in Example 1 was replaced with a superheated steam furnace adjusted to 280 ° C. instead of a superheated steam treatment for 50 minutes in a superheated steam furnace adjusted to 250 ° C. for each mold. An endless belt 1G was produced in the same manner as in Example 1 except that the superheated steam treatment was performed for a minute. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.01% by mass.
(Comparative Example 2)
A film-like molded body produced in the same manner as in Example 1 was replaced with a superheated steam furnace adjusted to 270 ° C. instead of a superheated steam treatment for 50 minutes in a superheated steam furnace adjusted to 250 ° C. for each mold. An endless belt 1H was produced in the same manner as in Example 1 except that the superheated steam treatment was performed for a minute. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.02% by mass.
(Comparative Example 3)
A film-like molded body produced in the same manner as in Example 1 was replaced with a superheated steam furnace adjusted to 260 ° C. instead of a superheated steam treatment for 50 minutes in a superheated steam furnace adjusted to 250 ° C. for each mold. An endless belt 1I was produced in the same manner as in Example 1 except that the superheated steam treatment was performed for a minute. The residual solvent amount of the endless belt substrate after the superheated steam treatment was 0.03% by mass.

  The three side surfaces of the produced endless belts 1A to 1I are arbitrarily selected and cut out, and an ultra-deep color 3D shape measurement microscope (trade name “VK-9500GII”, manufactured by KEYENCE Inc.) is used according to the above method. The point average roughness Rz, the average interval Sm of irregularities, and the arithmetic average roughness Ra were measured. The results are shown in Table 1.

  Further, the produced endless belts 1A to 1I are respectively attached to the image forming apparatus shown in FIG. 4 (tension 100 to 3,000 gf), and the endless belt is printed on an endless track at a speed of printing 21 sheets / min. Was run for 150,000 revolutions, and the side surface of the endless belt was checked for cracks and / or breakage. The case where cracks and breakage did not occur even when the endless belt was run at 200,000 revolutions was marked with “◎”, and the case where cracks and breakage did not occur even when the endless belt was run at 150,000 revolutions was marked with “◯”. When the endless belt travels 100,000 times, the case where cracks and / or breakage occurred on the side surface was evaluated as “x”. The results are shown in Table 1.

FIG. 1 is a schematic perspective view showing an endless belt according to an embodiment of the present invention. FIG. 2 is a schematic top perspective view showing a state in which an endless belt provided with meandering preventing means according to an embodiment of the present invention is stretched around a support roller. FIG. 3 is a schematic top perspective view showing a state in which an endless belt having meandering preventing means, which is another embodiment of the present invention, is stretched around a support roller. FIG. 4 is a schematic view showing a tandem color image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endless belt 2 Side surface 3 Support roller 4 Flange 5 Hole 6 Convex body 10 Image forming apparatus 11 Image carrier 12 Charging means 13 Exposure means 14 Transfer means 15 Cleaning means 16 Recording body 20 Developing means 21 Housing 22 Developer 23 Developing Agent carrier 24 Developer regulating member 30 Transfer conveyor belt 31 Cassette 32 Fixing means BK, C, M, Y Developing unit

Claims (4)

An endless belt manufacturing method for manufacturing an endless belt having a side surface with a ten-point average roughness Rz of 1.20 μm or less and an average interval Sm of unevenness of 10.0 μm or less ,
A molding step of centrifugally molding a resin composition containing an aromatic polyamideimide resin;
A primary solvent removing step for removing the solvent contained in the layer of the resin composition developed by centrifugal molding;
The obtained film-like molded body is heated with superheated steam at 200 to 260 ° C. for 30 to 60 minutes to remove the secondary solvent to obtain an endless belt substrate having a solvent residual amount of 0.04 to 0.30% by mass. Process,
A method for producing an endless belt, comprising a step of cutting a side end portion of the endless belt substrate and not performing surface processing of the cut surface.   The method for producing an endless belt according to claim 1, wherein the solvent is a solvent used in a polycondensation reaction for synthesizing an aromatic polyamideimide resin. The method for producing an endless belt according to claim 1 or 2, wherein the primary solvent removing step is a step of passing hot air of 40 to 150 ° C into the layer of the resin composition. A side surface produced by the method for producing an endless belt according to any one of claims 1 to 3, wherein the ten-point average roughness Rz is 1.20 μm or less and the average interval Sm of unevenness is 10.0 μm or less. An image forming apparatus provided with an endless belt .

Images