JP2008122588A - Multilayered belt for image forming apparatus and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which enables an elastic layer to be formed by performing treatment such as the application of material only once, thereby improves the productivity and reduces a manufacturing cost, and permits the use of more inexpensive material, causes no loss of the material upon the application and, as a result, leads to large cost reduction. <P>SOLUTION: A manufacturing method of a multilayered belt for an image forming apparatus is provided in which at least two resin compositions chemically reacting to each other are mixed and the elastic layer is formed by using the mixed resin compositions. The multilayered belt for the image forming apparatus is obtained by using the manufacturing method thereof. Further in the manufacturing method of the multilayered belt for the image forming apparatus, the elastic layer is formed by applying the mixed resin compositions with the use of a dispenser. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer belt for an image forming apparatus and a method for manufacturing the same, and more particularly to an image forming apparatus in which an elastic layer is formed by mixing a resin composition which becomes an elastic body by chemical reaction and applying a predetermined thickness. The present invention relates to a multilayer belt and a manufacturing method thereof.

Belts such as transfer belts and fixing belts of color image forming apparatuses not only simply transfer toner or fix toner on paper, but also melt a total of four types of toners of three primary colors and black, It is necessary to mix evenly and display the neutral colors and shades clearly. For this reason, moderate elasticity is required in the thickness direction.
In addition, if the inherently adhering toner remains adhered to the surface of the belt, the image formation is adversely affected. For this reason, the surface of the belt needs to have a high level of releasability (property of releasing toner when necessary. In a broad sense, non-adhesiveness with other substances).
Further, in the process of image formation, the belt is required to have mechanical strength because it is repeatedly exposed to mechanical stress such as bending, tension and pressing, and electrical stress due to static electricity.

  It is difficult to satisfy these properties with a belt composed of only one type of resin layer. For example, in a transfer belt or a fixing belt, the base material (base material layer; hereinafter referred to as “base material”) that is responsible for strength is used. An elastic layer is formed on the (paper) side, and a surface layer is further formed thereon. The base material is made of polyimide having excellent strength and heat resistance (hereinafter referred to as “PI”), and the elastic layer is made of urethane resin (including urethane rubber) having appropriate elasticity. Is used a fluororesin having a high degree of releasability.

  Although it is a base material made of PI, its thickness is about 80 μm, and a PI varnish in which a conductive agent is dispersed and the viscosity is adjusted is applied to the outer peripheral surface of a rotating drum-shaped mold. It is formed by a method in which the mold is heated to about 380 ° C. and an imidization reaction is performed.

Although it is a surface layer made of fluororesin, its thickness is about 8 μm, and tetrafluoroethylene perfluoroalkyl vinyl ether in which a conductive agent is dispersed on the inner peripheral surface of a stainless steel outer cylinder whose inner peripheral surface is mirror-finished Copolymer (hereinafter referred to as “PFA”), polytetrafluoroethylene (hereinafter referred to as “PTFE”) disversion, etc. are applied by a dip method, and the mold is heated to about 380 ° C. and baked. It is formed.
However, since it is difficult to achieve good adhesion to the elastic layer due to high releasability as it is, a binder with a thickness of about 1 μm is usually provided on the inner peripheral surface (surface on the side opposite to the outer cylinder) of the surface layer. Adhesion improvement processing such as forming a layer or exposing the inner peripheral surface to plasma or radicals to roughen the surface is performed (Patent Document 1).
JP 2006-47621 A

  About an elastic layer, in order to give moderate elasticity to the thickness direction, it is necessary to make the thickness of an elastic layer into about 70-250 micrometers thick. However, due to material restrictions, unlike the base material and surface layer, it cannot be formed at the same time, and the same operation must be repeated many times to gradually increase the layer thickness. For example, when an elastic layer is formed by applying aqueous urethane (volume melting point: 120 ° C., thermal decomposition point: 180 ° C.), etc., in which the volume resistivity is adjusted by dispersing a conductive agent, by spraying and then drying, When thickly applied, only the upper (air) water-based urethane dries and cracks occur inside, so that only a thickness of about 5 μm can be formed at a time.

As described above, in order to obtain an elastic layer having a predetermined thickness, it is necessary to repeat the same forming process at least a dozen or so times, which is a significant cost increase factor for belt manufacture.
In addition, the material itself is expensive, which leads to an increase in the cost of the product.
Furthermore, since the material is scattered when spraying, the material loss is very large, which also leads to an increase in cost.

  For these reasons, it is possible to form an elastic layer by performing processing such as application of the material only once, increasing productivity, reducing manufacturing costs, and using less expensive materials. There was no loss of material at the time, and as a result, development of a technology that would lead to a significant cost reduction was desired.

  In addition, since the currently used water-based urethane is thermoplastic urethane, products having a rubber hardness of 60 degrees or less are not commercially available. However, if the elastic layer is formed of a material having a lower hardness (soft), it is elastic. The required thickness of the layer is thin, which also leads to cost reduction. For this reason, it has been desired to form the elastic layer using a material having a rubber hardness lower than that at present.

  The present invention has been made for the purpose of solving the above-described problems. By mixing, a resin composition that is chemically cured by reaction to become an elastic body is mixed, and the mixed resin composition is reacted. It is hardened to form an elastic layer. The invention of each claim will be described below.

The invention described in claim 1
A method for producing a multilayer belt for an image forming apparatus, comprising mixing two or more chemically reacting resin compositions and forming an elastic layer using the mixed resin composition.

  In the invention of this claim, the material for forming the elastic layer is not a dry-curing type, but a resin composition that is chemically reacted and cured by mixing to form an elastic body. It is possible to form an elastic layer by performing this process once, which can increase productivity and reduce manufacturing costs. Also, the material cost is low, and no material loss occurs during application, resulting in a significant cost reduction.

As such a resin composition, two or more resin compositions containing the resin composition containing a main ingredient component and the resin composition containing a hardening | curing agent component are used, for example. Further, from the viewpoint of workability, a type in which two liquids are mixed instead of three liquids or more is preferable, and a type in which substantially equal amounts of raw material resins are mixed is more preferable. In terms of reactivity, curing is preferably initiated and accelerated by increasing the temperature, and there is no change in volume or generation of gas when a chemical reaction is made into an elastic body. Even very few types are preferred.
Further, other components such as a conductive agent may be mixed (blended).
Furthermore, application | coating is not limited to the method of using a dispenser, You may be made | formed by the other method.

  In addition, the “belt” is not limited to a so-called endless belt such as a fixing belt or a transfer belt, and is fixed directly by being wound around a solid core as long as it is used in an image forming apparatus. And a belt used as a part of a transfer roller, a fixing roller and the like. In addition, when using for a roller, there is no base material made from PI or polyamide-imide (PAI), and a two-layer structure with a surface layer may be included (included in the present invention).

The invention according to claim 2 is a method of manufacturing a multilayer belt for the image forming apparatus,
The mixed resin composition is one of a combination of an isocyanate and a polyol, a combination of a blocked isocyanate and a polyamine, a two-component reactive silicone, and a two-component reactive epoxy, and a multilayer belt for an image forming apparatus. It is a manufacturing method.

  In the invention of this claim, since any one of the above mixed resin compositions is used, the initiation and promotion of curing can be controlled more easily by increasing the temperature. Further, when an elastic body is obtained by a chemical reaction, volume change and generation of gas are less, which is suitable for forming an elastic layer. Further, depending on the conditions, the entire reaction hardening can be controlled uniformly.

The invention according to claim 3 is a method of manufacturing the multilayer belt for the image forming apparatus,
The elastic layer is formed by applying the mixed resin composition using a dispenser, and is a method for producing a multilayer belt for an image forming apparatus.

  In the invention of this claim, since the mixed resin composition is applied using a dispenser, unlike the spraying method, there is no loss of material due to scattering, and it is possible to apply an accurate amount at a time. For this reason, it is possible to form an elastic layer having an accurate film thickness at a low cost.

The invention according to claim 4 is a method of manufacturing the multilayer belt for the image forming apparatus,
The dispenser is a two-component dispenser, characterized in that each of the two chemically reacting resin compositions is continuously blended and mixed, and then continuously applied as it is. A manufacturing method of a multilayer belt for an image forming apparatus.

  In the invention of the present claim, in order to apply the two liquids in a hermetically mixed chamber by using a two liquid dispenser, continuously blending and mixing the two liquids in a predetermined amount, and then continuously dispensing them. It is excellent in mass productivity and preferable from the viewpoint of productivity.

The invention according to claim 5 is a method of manufacturing a multilayer belt for the image forming apparatus,
The mixed resin composition is applied only once, and is a method for producing a multilayer belt for an image forming apparatus.

  In the present invention, since the elastic layer having a predetermined thickness is formed by only one application, the elastic layer can be manufactured at low cost.

The invention according to claim 6 is a method of manufacturing a multilayer belt for the image forming apparatus,
A method for producing a multilayer belt for an image forming apparatus, wherein the elastic layer is formed to a thickness of 50 μm to 500 μm.

In the present invention, since the elastic layer is formed to a thickness of 50 μm to 500 μm, a belt for an image forming apparatus, particularly a transfer belt, having an appropriate elasticity can be obtained.
The thickness of the elastic layer is usually preferably from 70 μm to 250 μm, although it depends on the use of the belt.

The invention according to claim 7 is a method of manufacturing a multilayer belt for the image forming apparatus,
In the mixed resin composition, a conductive agent is blended, and this is a method for producing a multilayer belt for an image forming apparatus.

In the invention of this claim, since the elastic layer has an appropriate electrical conductivity, the transfer of toner using static electricity is made good, and the adhesion of toner and dust due to charging to the belt is also prevented. Here, the conductive agent to be blended is not particularly limited.
In addition, the electrical conductivity has the balance of the thickness of the elastic layer and the electrical resistance of other layers such as the base material and the surface layer, but the surface resistivity should be about 10 ⁷ to 10 ¹⁴ Ω / □. Is preferred.

The invention according to claim 8 is a method of manufacturing a multilayer belt for the image forming apparatus,
The method for producing a multilayer belt for an image forming apparatus, wherein the elastic layer has a rubber hardness specified in JIS K 6301 of 20 to 80 degrees.

In the present invention, since the rubber hardness of the elastic layer is adjusted to 20 degrees to 80 degrees or less, a belt suitable for an image forming apparatus can be obtained.
In particular, by setting the rubber hardness to 60 degrees or less, the elastic layer can be made more flexible, and the thickness of the elastic layer can be reduced. Therefore, less material is required to form the elastic layer, and cost can be reduced from this aspect. It becomes possible.
If the rubber hardness is less than 20 degrees, molding becomes difficult such as causing poor curing (insufficient reaction), and if it exceeds 80 degrees, the elasticity is insufficient.
The rubber hardness is adjusted, for example, by adjusting the components of the curing agent.

The invention according to claim 9 is:
A multilayer belt for an image forming apparatus, comprising an elastic layer formed by mixing two or more chemically reacting resin compositions and reaction curing.

  The invention of this claim captures claim 1 as an invention of a manufacturing method as a product invention.

The invention according to claim 10 is a multilayer belt for the image forming apparatus,
A multilayer belt for an image forming apparatus, wherein the elastic layer has a hardness of 20 to 80 degrees as a rubber hardness specified in JIS K 6301.

  The invention of this claim captures Claim 8 which is an invention of a manufacturing method as a product invention.

  In the present invention, it is possible to form an elastic layer by performing treatment such as coating using a dispenser once, thereby improving productivity and reducing manufacturing costs. In addition, the material cost is low, there is no loss of material at the time of application, and the cost is reduced.

  Hereinafter, the present invention will be described based on preferred embodiments thereof. Note that the present invention is not limited to the following embodiments. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

(First embodiment)
This embodiment relates to forming an elastic layer on the outer peripheral surface of a PI base material already formed on the outer peripheral surface of a drum-shaped mold.

  Isocyanate (LP-120 manufactured by Asahi Glass Urethane Co., Ltd. (viscosity is 48,000 mPa · s) at 25 ° C.) and a polyol {Asahi Glass, which is a main agent of a so-called two-component reaction curing type prepolymer (raw material) of urethane type LC0044 manufactured by Urethane Co., Ltd. (viscosity is 3,800 mPa · s at 25 ° C.)} was blended at a weight ratio of 100: 102, and stirred and uniformly mixed using a blade stirrer. After defoaming the mixed resin composition under reduced pressure, it was applied at once to a predetermined thickness on a base material previously formed on the outer peripheral surface of a drum-shaped mold using a dispenser.

Then, it hold | maintained at 130 degreeC for 10 minute (s), it was made to harden | cure, and the 200-micrometer-thick elastic layer which consists of urethane type resin was formed.
Further, it was heated at 80 ° C. for 6 hours as a secondary cure and cured at room temperature for 3 days. It was 40 degree | times when the rubber hardness of the elastic layer after curing was measured by the method prescribed | regulated to JISK6301.
The surface resistivity of the elastic layer was 10 ¹⁰ Ω / □, but the surface resistivity of the elastic layer can be controlled by adding a conductive agent as necessary.

  This state is shown in FIG. In FIG. 1, 10 is a metal mold | die, 11 is a base material, 12 is an elastic layer.

As a surface layer of the belt, a PFA morphology improved product (trade name: 945HP plus, melting point: 295 ° C.) manufactured by DuPont, which is a kind of fluororesin, is used, and stainless steel (thermal expansion coefficient is 1.76 × 10 ⁻⁵ / ° C.). ) It was baked at about 380 ° C. on the inner peripheral surface of the manufactured outer cylinder. Further, a binder layer made of THV (THV220 manufactured by Sumitomo 3M Co., melting point: 120 ° C.) was deposited on the inner surface of the surface layer at about 350 ° C. as an adhesive improvement treatment.
This state is shown in FIG. In FIG. 2, 8 is an outer cylinder, 9 is a surface layer, and 14 is a binder layer.

Next, the belt of the semi-finished product in which the elastic layer is formed on the base material is removed from the mold, and is fitted into a core made of nylon 6 (thermal expansion coefficient is 8.0 × 10 ⁻⁵ / ° C.). The core in the state was inserted into a stainless steel outer cylinder having a surface layer and a binder layer formed on the inner surface.
This state is shown in FIG. In FIG. 3, 13 is a core.
Then, the whole is held at 120 ° C. for 30 minutes in a vacuum, and the inner peripheral surface of the surface layer and the outer peripheral surface of the elastic layer are strengthened through the binder layer by utilizing the difference in thermal expansion coefficient between the core and the outer cylinder. And a multilayer belt composed of 3 layers (4 layers if a binder layer is included) was completed.

FIG. 4 conceptually shows the difference in forming the cross section of the multilayer belt according to the first embodiment of the present invention and the multilayer belt of the prior art. (1) on the left side of FIG. 4 is a diagram showing the multilayer belt according to the first embodiment, and (2) on the right side is the elasticity of the conventional multilayer belt in which the urethane layer 19 is formed little by little. It is a figure which shows notionally a mode that the layer 12 is formed. In (2) of FIG. 4, 19 is a urethane formed to a thickness of about 5 μm by applying a water-based urethane {trade name “Adekabon titer HUX-1230”} manufactured by ADEKA and drying it. Is a layer. In addition, the hardness of the urethane rubber of the conventional elastic layer was 70 degrees.
On the other hand, in the multilayer belt of the first embodiment, the elastic layer is formed by applying the mixed resin composition once, and the material is also a two-component mixed resin composition. The hardness of the urethane rubber was 40 degrees.

(Second Embodiment)
The present embodiment relates to forming an elastic layer on the inner peripheral surface of the surface layer formed on the inner peripheral surface of a stainless steel cylindrical mold.
Forming a surface layer using a PFA morphology improved product (trade name 945HP plus) is the same as in the first embodiment. After forming the surface layer, the inner peripheral surface of the surface layer was exposed to plasma or radicals to improve surface adhesion. For this reason, a binder layer is not formed on the inner peripheral surface of the surface layer of the second embodiment.
Next, an isocyanate {LP-120 made by Asahi Glass Urethane Co., Ltd.), which is a main component of a urethane-based two-component reaction curable prepolymer (raw material), and a polyol {LC0044 made by Asahi Glass Urethane Co., Ltd.), which is a curing agent, are 100 by weight. It mix | blended in the ratio of 102, and it stirred and mixed uniformly using the blade | wing stirring apparatus. The mixed resin composition was degassed under reduced pressure, and then applied at once to a predetermined thickness on the inner peripheral surface of the surface layer with improved adhesion using a dispenser.

Then, it was made to harden | cure by hold | maintaining at 130 degreeC for 10 minute (s), and the 200-micrometer-thick elastic layer which consists of urethane type resin was formed in the state firmly fixed to the internal peripheral surface of the surface layer.
Further, it was heated at 80 ° C. for 6 hours as a secondary cure and cured at room temperature for 3 days. It was 40 degree | times when the rubber hardness of the elastic layer after curing was measured by the method prescribed | regulated to JISK6301.

The base material was formed on the outer peripheral surface of the drum-shaped mold as in the first embodiment.
Next, the base material formed on the mold is removed from the mold, and fitted into the outer periphery of a cylindrical bag made of silicon rubber whose diameter expands in the radial direction by water pressure. Further, the bag in this state is placed on the inner peripheral surface. Inserted into the inside of a stainless steel cylindrical mold in which the surface layer and elastic layer are integrally formed, while keeping the whole in a vacuum and applying water pressure in the bag to inflate the bag in the radial direction, the outer circumference of the base material The surface was pressed to the inner peripheral surface of the elastic layer under heating.

The state of this state and the main part of the manufacturing equipment are shown in FIG. In FIG. 5, 9i is an inner peripheral surface of the surface layer 9 whose adhesion is improved by radicals, 50 is a bag, 52 is a trunk of the bag, 55 is an end of the bag, and 59 is a pump. 60 is a vacuum chamber, 61 is a lid, 62 is a vacuum pump, and 70 is a heating coil heater.
As shown in FIG. 5, in the vacuum chamber 60, the elastic layer 12 formed on the surface layer 9 through the portion 9 i formed on the inner peripheral surface thereof and subjected to the radical treatment, and the base material 11 are expanded. Pressed between the bag 50 and the outer cylinder 8 under vacuum and heating, and this state is maintained at 130 ° C. for 10 minutes to firmly bond the inner peripheral surface of the elastic layer 12 and the outer peripheral surface of the substrate 11, A fixing belt consisting of three layers was completed.
Similarly to the multilayer belt of the first embodiment, the elastic layer of the fixing belt of the second embodiment is also formed of a flexible urethane rubber.

(Third embodiment)
The present embodiment is the same as the first embodiment except that a two-component mixed dispenser is used and two-component mixing and coating are performed continuously. Hereafter, the principal part of this Embodiment is demonstrated.

  The main component and curing agent are blended in a two-part dispenser {AMK Corporation, trade name MAZEDAS, and the isocyanate and polyol are blended at a ratio of 100: 102 by weight in a sealed mixing chamber, uniformly While mixing, it was applied at once to a predetermined thickness on a base material previously formed on the outer peripheral surface of a drum-shaped mold.

Mixing, mixing, and discharging of the main agent and the curing agent in the two-component dispenser are performed as follows.
First, the main agent and the curing agent filled in each dedicated tank in the deaerated state are supplied in equal amounts from the respective tanks above the mixing chamber under the control of the valves.
Next, both of the supplied liquids move downward from above the mixing chamber while being mixed by a motor in the sealed mixing chamber.
Finally, the mixed resin composition discharged from the lower side of the mixing chamber is applied on the base material at a predetermined thickness at a time.

  After that, as in the first embodiment, the semi-finished belt having an elastic layer formed on the base material is removed from the mold, fitted into a nylon 6 core, and the core in this state is attached to the inner surface. Inserted into a stainless steel outer cylinder where the surface layer and binder layer are formed, heated and pressed in vacuum to adhere the elastic layer and binder layer, and further heated at 80 ° C. for 6 hours as a secondary cure, Cured for 3 days at room temperature. It was 40 degree | times when the rubber hardness of the elastic layer after curing was measured by the method prescribed | regulated to JISK6301.

In the 1st Embodiment of this invention, it is a figure which shows notionally the mode that the base material and the elastic layer are formed in the outer peripheral surface of a metal mold | die. In the 1st Embodiment of this invention, it is a figure which shows notionally the mode that the surface layer and the binder layer are formed in the internal peripheral surface of an outer cylinder. In the 1st Embodiment of this invention, it is a figure which shows notionally a mode that the surface layer and the elastic layer are adhere | attached by the heating and press under vacuum through the binder layer. It is a figure which shows notionally the difference of the cross-sectional structure of the multilayer belt of the 1st Embodiment of this invention, and the multilayer belt of a prior art. In the 2nd Embodiment of this invention, it is a figure which shows notionally a mode that the surface layer and the elastic layer are adhere | attached by the heating under vacuum, the press using a bag, and the apparatus for it.

Explanation of symbols

8 Outer cylinder 9 Surface layer 9i Surface layer 10 subjected to adhesion improvement treatment Mold 11 Base 12 Elastic layer 13 Core 14 Binder layer 19 Urethane layer formed little by little 50 Bag 52 Bag body 55 End of bag 59 Pump 60 Vacuum chamber 61 Lid 62 Vacuum pump 70 Coil heater for heating

Claims (10)

  A method for producing a multilayer belt for an image forming apparatus, comprising mixing two or more chemically reacting resin compositions and forming an elastic layer using the mixed resin compositions.   2. The image formation according to claim 1, wherein the mixed resin composition is one of a combination of isocyanate and polyol, a combination of blocked isocyanate and polyamine, a two-component reactive silicone, and a two-component reactive epoxy. A method for producing a multilayer belt for an apparatus.   The method for producing a multilayer belt for an image forming apparatus according to claim 1, wherein the elastic layer is formed by applying the mixed resin composition using a dispenser.   The dispenser is a two-component dispenser, characterized in that each of the two chemically reacting resin compositions is continuously blended and mixed, and then continuously applied as it is. A method for producing a multilayer belt for an image forming apparatus according to any one of claims 1 to 3.   The method for producing a multilayer belt for an image forming apparatus according to claim 3 or 4, wherein the mixed resin composition is applied only once.   6. The method for producing a multilayer belt for an image forming apparatus according to claim 1, wherein the elastic layer is formed to a thickness of 50 [mu] m to 500 [mu] m.   The method for producing a multilayer belt for an image forming apparatus according to claim 1, wherein a conductive agent is blended in the mixed resin composition.   The method for producing a multilayer belt for an image forming apparatus according to any one of claims 3 to 7, wherein the elastic layer has a rubber hardness of 20 to 80 degrees as defined in JIS K6301. .   A multilayer belt for an image forming apparatus, comprising an elastic layer formed by mixing and chemically curing two or more chemically reacting resin compositions. The multilayer belt for an image forming apparatus according to claim 9, wherein the elastic layer has a rubber hardness of 20 to 80 degrees as defined in JIS K 6301.

Images