JP2009090481A - Die for manufacturing ring-shape seamless molded article, manufacturing apparatus for ring-shape seamless molded article equipped with the die, and manufacturing method of ring-shape seamless molded article using the die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for manufacturing a ring-shape seamless molded article which, even when oxidative deterioration occurs in a release layer of the die, enables only a component of the die in which the oxidative deterioration has occurred to be replaced or enables the release layer of only the component of the above die to be reformed and which therefore is excellent in economic efficiency, to provide manufacturing apparatus for a ring-shape seamless molded article, equipped with the die, and to provide a manufacturing method of a ring-shape seamless molded article using the die. <P>SOLUTION: The die 1 is used for manufacturing a ring-shape seamless molded article and is formed by applying a resin solution 3 for a molded article onto the release layer 4 disposed on an outer circumferential surface or an inner circumferential surface of the die, wherein a split face 2 is disposed on at least one part in an application area of the resin solution 3. The manufacturing apparatus for ring-shape seamless molded article, equipped with the die is provided. The manufacturing method of ring-shape seamless molded article using the die is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mold for manufacturing an annular seamless molded body, an apparatus for manufacturing an annular seamless molded body including the mold, and a method for manufacturing an annular seamless molded body using the mold.

  In an image forming apparatus, a thin resin belt is often used as a photoreceptor or an intermediate transfer member. Since such a resin belt can be deformed, it is useful for reducing the diameter of the apparatus. If the resin belt has a seam, a defect due to the seam occurs in the output image, and therefore a seamless belt without a seam is preferable.

  The seamless belt is manufactured, for example, by a method in which a resin solution is applied to the outer peripheral surface or inner peripheral surface of a mold, the resin coating film is heated, and the resulting resin coating film is demolded. In particular, a seamless belt made of polyimide resin is a method in which a polyimide precursor solution is applied to the outer peripheral surface or inner peripheral surface of a mold, the resin coating is heated and dried and reacted, and the resulting resin coating is demolded. Manufactured by. In general, a mold is used in such a manner that a release layer such as a silicone resin film is formed on a resin solution-coated surface in order to facilitate removal of a resin film (for example, Patent Document 1).

  However, since the release layer has a defect that the surface is likely to be oxidized and deteriorated by heating, if the resin solution is not applied on the surface of the release layer and is in contact with the air layer, the thermal oxidation is intense. When the resin solution was applied and heated on the release layer that was oxidized and deteriorated, the resin film did not leave the mold, and the resin film molded body was damaged. Therefore, it has been difficult to repeatedly use the mold. Moreover, since the oxidative degradation of the release layer is difficult to visually discern, it was often recognized that the oxidative degradation occurred only after the resin film molded body was damaged.

  In order to solve such a problem, it is sufficient that the resin solution can be applied to the entire surface of the release layer. However, when the resin solution is applied to the entire surface of the release layer, the resin solution droops at the end of the mold, and the resin solution adheres to an apparatus other than the mold, causing a maintenance failure of the apparatus. Further, when the resin solution wraps around the end of the mold, the resin film molded body has an undercut shape, which makes it difficult to remove the mold. Therefore, it is necessary to apply the resin solution to the mold while leaving the end portion, and the problem of oxidative deterioration of the release layer at the end portion cannot be avoided. In addition, since the mold is generally composed of one member, if oxidation degradation occurs in the release layer, it is necessary to replace the entire mold or re-form the entire release layer, which has a problem in terms of economy. .

On the other hand, a cylindrical core body holding body that holds both ends of the cylindrical core body,
Two holding members for holding both ends of the cylindrical core,
A shaft member connecting the two holding members;
A change means for changing a holding interval of the two holding members in an axial direction of the cylindrical core body according to a volume change due to heat addition of the cylindrical core body,
There is disclosed a cylindrical core body holding body (Patent Document 2). Such a holder for a cylindrical core body and a cylindrical core body are not applied to their joints, that is, the resin solution is applied leaving both ends of the core body. Therefore, when a release agent is applied to the surface of the core in advance, the release layer is oxidized and deteriorated at both ends of the core, and the entire core needs to be replaced. Further, with this method, it is necessary to transfer the core body after the resin solution is applied and to attach the holding means, and problems such as dripping of the resin solution of the viscous material and adhesion to unnecessary portions may occur. .
JP 2007-100208 A JP 2005-270805 A

  In the present invention, even if oxidation degradation occurs in the release layer, it is possible to replace only the mold part in which oxidation deterioration has occurred, or to re-form the release layer of only the mold part. An object of the present invention is to provide a mold for producing an annular seamless molded body excellent in the above, an apparatus for producing an annular seamless molded body provided with the mold, and a method for producing an annular seamless molded body using the mold.

The present invention is a mold for producing an annular seamless molded body by applying a resin solution for a molded body on a release layer having an outer peripheral surface or an inner peripheral surface,
A mold having a split surface in at least one location in a resin solution application region, an apparatus for manufacturing an annular seamless molded body provided with the mold, and an annular seamless molded body using the mold Regarding the method.

The present invention is also a mold for producing an annular seamless molded body by applying a resin solution for a molded body on a release layer having an outer peripheral surface or an inner peripheral surface,
Within the resin solution application area of the mold, there is a split surface at at least one end of the mold,
A mold body having a mold body and an end mold detachably coupled to at least one end of the mold body section, an apparatus for producing an annular seamless molded body having the mold, and the mold The present invention relates to a method for producing an annular seamless molded body.

Since the mold of the present invention is applied with the resin solution leaving the end portion, except for the case where there is a step as described later, it is possible to prevent the maintenance trouble of the apparatus due to the dripping of the resin solution, and the mold removal is difficult. It is possible to prevent the formation of an undercut shape.
Since the mold of the present invention has a split surface at least at one position in the resin solution application region, even if the mold release layer is oxidized and deteriorated, either the mold part in which the oxide deterioration has occurred is exchanged, or the A release layer of only the mold part can be re-formed. On the other hand, mold parts that have not undergone oxidative degradation can be used repeatedly. As a result, the mold of the present invention is excellent in economic efficiency.

<Mold>
A mold according to the present invention has a release layer on an outer peripheral surface or an inner peripheral surface, and a resin solution for a molded product is applied on the release layer to produce an annular seamless molded product. is there. When the resin solution is applied onto the release layer on the outer peripheral surface of the mold, the mold may be a hollow body or a solid body. When the resin solution is applied on the release layer on the inner peripheral surface of the mold, the mold is a hollow body.

The mold of the present invention has a dividing surface at least at one place, preferably at two places in the resin solution coating region.
The resin solution application region is a region where the resin solution is actually applied, and is set in advance when the annular seamless molded body is manufactured.
Therefore, the presence of a divided surface in the resin solution application region means that the divided surface is hidden by the resin solution when the resin solution is actually applied. Accordingly, since the resin solution can be applied to the entire surface of the release layer, at least one mold part constituting the mold can be repeatedly used without causing oxidative deterioration of the release layer. If the mold has a split surface outside the resin solution application region, there is a region where the release layer is exposed in any mold part divided by the split surface, and oxidative degradation occurs. Any mold member requires re-formation or replacement of the release layer.

  The dividing plane is a plane that divides the mold axis. For example, a plane expressed by one straight line in a vertical section passing through the mold axis is a plane expressed by two or more straight lines. Alternatively, it may be a surface represented by a curve. The dividing surface is usually formed symmetrically with respect to the mold axis.

  The position where the mold has the divided surface is not particularly limited as long as it is within the resin solution application region. For example, as shown in FIGS. 1 (A) and 1 (B) and FIG. 2, the mold 1 (1a, 1b, 1d ) Is within the region where the resin solution 3 is applied, and may have split surfaces 2 at both ends of the mold. Also, for example, as shown in FIG. 1C, the mold 1 (1c) is in the region where the resin solution 3 is applied, and the dividing surface 2 is formed at one end (upper end in the figure) of the mold. You may have. In addition, for example, the mold may be within the region where the resin solution 3 is applied, and may have a dividing surface at a substantially central portion of the mold. Accordingly, since at least one mold part constituting the mold can be coated with the resin solution 3 on the entire surface of the release layer 4, the mold part can be used repeatedly without causing oxidative deterioration of the release layer. . The position where the mold has a divided surface is the position of the divided surface on the resin solution application surface of the mold. 1 (A) to 1 (C) and FIG. 2 are schematic configuration diagrams showing an embodiment of a mold of the present invention, and show a state where a resin solution is applied.

As shown in FIGS. 1 (A) to 1 (C) and FIG. 2, the mold of the present invention has a dividing surface 2 in the resin solution application region, and the mold 1 (1a, 1b, 1c, 1d). It is preferable that it exists in at least one edge part. As a result, the mold 1 includes a mold body 5 (5a, 5b, 5c, 5d) and an end mold (6a, 7a, 6b, 7b, 7c, removably coupled to at least one end of the mold body. 6d, 7d). Since the resin solution is applied to the entire surface of the release layer 4, the mold body can prevent the release layer from coming into contact with air during heating. Therefore, since oxidation can be suppressed, the release layer of the mold main body can ensure releasability even after heating and can be used repeatedly. In addition, since the oxidative deterioration of the release layer occurs in a limited manner in the end mold, it is effective for identifying a part of the release layer that is difficult to visually check. Therefore, it is possible to ensure the mold release property of the entire mold by re-forming the release layer of only the end mold, which is effective for cost reduction and quality assurance. Further, even when it becomes impossible to reuse due to oxidative deterioration, it is only necessary to replace the end mold, which is advantageous in terms of cost compared to replacing the entire mold.
Hereinafter, the present invention will be described in detail with reference to FIGS.

  A mold 1a according to an embodiment of the present invention shown in FIG. 1A includes detachable end molds 6a and 7a at both ends of a mold main body 5a, and the mold main body 5a and the detachable end mold 6a, The release layer 4 is provided on the outer peripheral surface of 7a. As shown in FIG. 1A, the mold 1a has the exposed region of the release layer 4 only in the end molds 6a and 7a, so that only the end molds 6a and 7a can be replaced or used during repeated use. What is necessary is just to re-form a release layer.

  The material constituting the mold body 5a and the end molds 6a, 7a is not particularly limited as long as it does not deform even when heated during the production of the seamless molded body. For example, aluminum, copper, steel, etc. Metal is preferably used. Among these, aluminum is particularly preferably used from the viewpoints of market distribution, solvent resistance, thermal conductivity, strength, and the like. When such a metal is processed into a predetermined shape of the mold main body or the end mold, the pipe or bar may be cut into a predetermined shape. In particular, when aluminum is used, it has a relatively low hardness among metals and is excellent in machinability.

  As the release layer 4, a silicone resin, a fluorine-containing resin, or the like is coated, or a silicone-based or fluorine-based release agent is coated.

  The mold release layer 4 may be formed of the same material as that of the mold main body portion and that of the end mold, or may be formed of different materials. Since the mold body is usually used in a portion corresponding to a seamless belt product, the mold release layer of the mold body has a high mold release function so as not to damage the product. By using the same material for the mold body release layer and the end mold release layer, high mold releasability is ensured and there is no difference in releasability, resulting in peeling unevenness. It is difficult to release the mold without damaging the product. When the mold release layer of the mold body and the mold release layer of the end mold are formed from different materials, the end mold release layer is inferior in mold release function, but uses a material with excellent durability. It is particularly effective for cost reduction by dramatically increasing the reuse rate of the end mold. As such an end-type release layer, for example, a Ni plating film can be used.

  In particular, if the end-type release layer is a Ni-plated film, the end-type reuse rate is considerably improved, which is economically more advantageous.

  The axial length X of the resin solution application region in the mold body 5a is equal to or larger than a predetermined width Y for one seamless molded body. For example, even if it is equal to Y, n × Y (n is a natural number equal to or greater than 2; It may be equal to or larger than the integral multiple). Preferably, the length X is equal to the predetermined width Y. When the length X is equal to Y, the resin film molded body formed after heating is cut at the dividing surface, and the molded body is removed from the divided mold main body, and can be used as it is. The body can be easily obtained.

The mold body 5a preferably has a rotation fulcrum on the axis of the mold body. For example, in FIG. 1A, a rotation fulcrum is provided on the shaft by providing the rotation fulcrum imparting portions 9a at both ends in the axial direction of the mold main body 5a. Thereby, a seamless molded body having a uniform film thickness can be produced. When producing a seamless molded body, when rotating the mold horizontally with respect to the axis during heating in the resin film forming process, if the end mold has a rotation fulcrum, the rotation axis does not necessarily coincide with the axis of the mold body Therefore, problems such as non-uniform film thickness occur in the molded body obtained on the mold body.
The rotation fulcrum imparting member 9a normally has a conical side surface shape and is formed of the same material as that of the end mold. In addition, the said mold main body part does not have a difference in the function, if it has a rotation fulcrum regardless of hollow and solid.

  The coupling form of the mold body 5a and the end molds 6a and 7a is not particularly limited as long as they are detachably integrated, and examples thereof include an engagement form, engagement of a round shaft and a round hole, and the like. It is done. As shown in FIG. 1A, the engagement is to achieve the coupling by inserting the convex portion into the concave portion. In FIG. 1A, for example, the connection between the end mold 7a and the mold body 5a is achieved by fitting the end mold protrusion into the recess of the mold body, and the mold body 5a and the end mold. The coupling | bonding with 6a is achieved by making the convex part of a type | mold main body part fit in the recessed part of an edge part type | mold. At this time, the coefficient of linear expansion is preferably higher than the member engaged with the outer side (the member having the concave part). As a result, what is fitted with a slight gap during cold changes to reduce the gap during heating, so it is superior in improving the center position accuracy of the mold body and end mold and preventing the end mold from coming off. It becomes. For example, in FIG. 1A, it is preferable to achieve the order of the linear expansion coefficient of the end mold 7a> the mold body 5a> the end mold 6a.

  The end molds 6a and 7a preferably have a movable member such as a recess and / or a wire in the resin solution application region of the end mold. FIG. 3 shows a schematic sketch of the end mold when the end mold 6a has a recess 14 in the resin solution application region 13 and a movable member 15 in the recess. The movable member 15 may be disposed on the mold surface in the resin solution application region 13. When the resin film molded body obtained on the mold is cut at the dividing surface and the molded body on the divided end mold is removed, the place corresponding to the concave portion in the molded body is the starting point of peeling. be able to. If the movable member is pulled up with a radio pen or the like in the molded body on the divided end mold, the molded body is torn and can be used as a starting point of peeling. If the movable member is pulled out of the molded body on the divided end mold, the molded body can be torn from the gap with a radix pen or the like to be a starting point of peeling. If the starting point of peeling is obtained in such a manner, it is possible to promote demolding of the molded body even if the mold release property of the end mold is not so good. If the end mold is Ni-plated at this time, the molded body can be peeled off without damaging the mold, so that it can be used permanently and is very economical.

  The end molds 6a and 7a at both ends of the mold 1a are both step-free molds having no step on the resin solution application surface, but a step may be provided on the resin solution application surface of one end mold.

A mold 1b according to an embodiment of the present invention shown in FIG. 1B uses an end mold 6b provided with a step forming member 8b as the end mold 6a in the mold 1a shown in FIG. 1A. Is. That is, the end mold 6b includes a step forming member 8b on the resin solution application surface, and as a result, has a step higher than the resin solution application surface. Thus, the release layer 4 and the resin solution 3 can be applied to the same length in the end mold 6b. Therefore, in the end mold 6b, a situation is created in which the release layer 4 and the resin solution 3 are almost overlapped, and the release layer 4 is effectively protected by the resin solution 3, so that oxidative deterioration of the release layer is suppressed. it can. Therefore, the end mold 6b having a step has a higher reuse rate than the end mold without a step, and can further contribute to cost reduction. Since the mold 1b has the exposed area of the release layer 4 only in the end mold 7b, only the end mold 7b needs to be replaced or the release layer re-formed during repeated use.
The step forming member 8b has a ring shape and is formed of the same material as the end mold.

  The dividing surface 2 in the mold 1b, the resin solution 3, the release layer 4, the mold body 5b, the end molds 6b and 7b, and the rotation fulcrum imparting part 9b are other than the end mold 6d having the step forming member 8b. Since these correspond to the dividing surface 2, the resin solution 3, the release layer 4, the mold body 5a, the end molds 6a and 7a, and the rotation fulcrum imparting part 9a in the mold 1a, description thereof is omitted.

  The mold 1a and the mold 1b both have end molds at both ends of the mold main body, but may have end molds only at one end of the mold main body.

A mold 1c according to an embodiment of the present invention shown in FIG. 1 (C) has an end mold 6a at one end of the mold main body in the mold 1a shown in FIG. It is provided. That is, the mold 1c is provided with a detachable end mold 7c at one end of the mold body 5c and a step forming member 8c at the other end. At the other end of the mold body 5c, the step forming member 8c is provided on the resin solution application surface, and as a result, the step is higher than the resin solution application surface. Thereby, the mold release layer 4 and the resin solution 3 can be apply | coated to the same length in the said other end. Therefore, a situation where the release layer 4 and the resin solution 3 substantially overlap each other at the other end of the mold body 5c is created, and the release layer 4 is effectively protected by the resin solution 3. Oxidative degradation can be suppressed. Therefore, the mold body 5c can be used repeatedly, and the oxidative degradation of the release layer is only one end mold 7c, and since its size is small, the cost is low, Excellent maintainability.
The step forming member 8c has a ring shape, and is formed from the same material as that of the end mold.

  The dividing surface 2, the resin solution 3, the release layer 4, the mold body 5c, the end mold 7c, and the rotation fulcrum imparting portion 9c in the mold 1c are respectively the dividing surface 2, the resin solution 3, and the release layer in the mold 1a. 4, since it corresponds to the die body 5a, the end die 7a, and the rotation fulcrum imparting portion 9a, description thereof is omitted.

  A mold 1d according to an embodiment of the present invention shown in FIG. 2 is obtained by forming a release layer 4 on the inner peripheral surface of the mold 1a shown in FIG. 1 (A), and a resin solution on the release layer. Is applied. That is, the mold 1d includes detachable end molds 6d and 7d at both ends of the mold main body 5d, and has a release layer 4 on the inner peripheral surfaces of the mold main body 5d and the detachable end molds 6d and 7d. Is. Since the mold 1d has the exposed area of the release layer 4 only in the end molds 6d and 7d, only the end molds 6d and 7d may be exchanged or the release layer may be re-formed during repeated use.

  The dividing surface 2, the resin solution 3, the release layer 4, the mold body 5d, the end mold 6d, and the end mold 7d in the mold 1d are the inner circumferences of the mold body 5d, the end mold 6d, and the end mold 7d. Apart from the fact that the release layer 4 is formed on the surface and the resin solution 3 is applied on the release layer 4, the divided surface 2, the resin solution 3, the release layer 4, the mold body 5 a, Since they correspond to the end mold 6a and the end mold 7a, description thereof is omitted. In the mold 1d, the coupling between the end mold 7d and the mold main body 5d is achieved by fitting the convex part of the mold main body into the concave part of the end mold, and the mold main body 5d and the end mold 6d This connection is achieved by fitting the end mold convex part into the concave part of the mold main body part.

<Apparatus for producing annular seamless molded body>
The apparatus for producing an annular seamless molded body according to the present invention is not particularly limited as long as the above-described mold is provided. Usually, a coating means for applying a resin solution for an annular seamless molded body to the mold, and the obtained It has heating means for heating the resin coating film.

The application means is not particularly limited as long as the resin solution can be applied on the outer peripheral surface or the inner peripheral surface of the mold, and those conventionally used in the manufacturing field of annular seamless molded bodies can be used. For example, the apparatus etc. which employ | adopted the coating method mentioned later are mentioned.
The heating means is not particularly limited, and examples thereof include a halogen heater and a fan heater.

<Method for producing annular seamless molded body>
The method for producing an annular seamless molded body of the present invention is characterized by using the above-described mold, and usually includes the following steps;
A resin coating film forming step of forming a resin coating film by applying a resin solution for an annular seamless molded article on the mold release layer of the mold;
A resin film forming step of heating the resin film to form a resin film; and a demolding process of peeling the resin film from the mold.

  In this invention, the well-known resin conventionally used for manufacture of a cyclic | annular seamless molded object is used, For example, a thermosetting resin or a thermoplastic resin etc. may be sufficient. It is preferable to use a thermosetting resin, particularly a polyimide resin, a polyamideimide resin, or the like. Thermosetting resins require heating at a relatively high temperature, and oxidative deterioration of the mold release layer is likely to occur. Even when such resins are used, the object of the present invention is effectively achieved. This is because it can.

  When producing a cyclic seamless molded body made of polyimide resin, as a polyimide precursor, a so-called polyamic acid such as 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine ( A precursor composed of PDA), a precursor composed of pyromellitic dianhydride (PMDA) and 4,4′-diaminophenyl ether (ODA), and the like are used.

When producing a cyclic seamless molded body made of polyamideimide resin, as a polyamideimide precursor, for example, a precursor comprising an amide group-containing aromatic diamine and PMDA, an aromatic diamine or a derivative thereof, and trimellitic anhydride (TMA) A precursor made of or the like is used.
Hereinafter, as a particularly preferred embodiment, a method for producing an annular seamless molded body made of polyimide resin will be described in detail.

(Resin coating film forming process)
In this step, first, a polyimide precursor is dissolved in an organic solvent to prepare a resin solution.
The polyimide precursors described above can be used, and two or more kinds may be mixed and used.

  The organic solvent is not particularly limited as long as it can dissolve the polyimide precursor, and examples thereof include N-methylpyrrolidone, N, N-dimethylacetamide, acetamide, N, N-dimethylformamide and the like. The concentration, viscosity, and the like of the polyimide precursor in the resin solution are appropriately selected according to the coating method, the desired thickness of the molded body, and the like.

When the obtained molded product is used for an application such as a fixing belt, an intermediate transfer belt, or a contact charging belt that needs to be provided with a conductive function, an additive such as a conductive substance is added to the resin solution. Can be dispersed.
Examples of the conductive material include carbon black, carbon beads granulated from carbon black, carbon-based materials such as carbon fiber and graphite, metals or alloys such as copper, silver, and aluminum, tin oxide, indium oxide, antimony oxide, Examples thereof include conductive metal oxides such as SnO ₂ —In ₂ O ₃ composite oxide.

  Next, the resin solution is applied onto the mold release layer of the mold to form a resin coating film 3 as shown in FIGS. 1A to 1C and FIG. 2, for example. That is, the coating is performed not only on the release layer 4 of the mold main body 5 but also in a range exceeding the dividing surface 2 when viewed from the mold main body 5. In addition, when apply | coating to the metal mold | die edge part which does not have a level | step difference, the exposure area | region of the mold release layer 4 is ensured from a viewpoint of dripping prevention or prevention of provision of an undercut shape. When applying to the edge part of a mold having a step, it is not necessary to secure an exposed area of the release layer 4.

  The application method is not particularly limited as long as the resin solution can be applied on the outer peripheral surface or inner peripheral surface of the mold, and a method conventionally used in the manufacturing field of an annular seamless molded body can be used. is there. For example, a ring coating method, a blade coating method, a bar coating method, a roll coating method and the like can be mentioned.

(Resin film formation process)
In this step, the resin coating is heated to form a resin coating. Specifically, after the resin coating film is dried by heating, a polyimide resin film is formed by heating reaction.

  First, for the purpose of removing the solvent that remains excessively in the resin coating film, heat drying is performed to such an extent that the coating film does not deform even when left standing. The drying conditions are preferably 80 to 200 ° C. and 30 to 60 minutes. At that time, the higher the temperature, the shorter the heating time. In addition to heating, it is also effective to apply wind. Moreover, if far infrared heating is used, solvent removal can be performed more efficiently. Heating may be increased stepwise or at a constant rate over time. If the solvent is removed too much from the resin coating film, the coating film does not yet retain the strength as a molded body, and there is a risk of cracking. For this reason, it is preferable to leave the solvent appropriately. Specifically, it is preferable to leave the solvent in the resin coating film at a rate of 15 to 50% by mass, particularly 35 to 50% by mass.

  Subsequently, a polyimide resin film can be formed by heat-reacting a resin film for 20 to 60 minutes at 300 to 450 ° C., preferably around 350 ° C. During the heating reaction, if the organic solvent remains in the coating film, the polyimide resin film may swell, so it is preferable to completely remove the residual solvent before reaching the final temperature of heating, Specifically, before heating, the solvent is removed by heating and drying at a temperature of 200 to 250 ° C. for 10 to 30 minutes, and then the temperature is gradually increased stepwise or at a constant rate. It is preferable to form a polyimide resin film. At this time, if the far infrared heating is used in combination, the removal of the residual solvent and the imidization reaction can be performed efficiently.

(Demolding process)
In this step, the polyimide resin film is peeled off from the mold and removed. The resin film formed on the mold may be peeled off with compressed air as it will be described later. However, in the present invention, since the above-described mold is used, the resin film is first formed on the divided surface in this step. After cutting the mold body and separating the mold body from the end mold, it is preferable to peel off the resin film formed on the mold body.

  The resin film is peeled off from the mold main body by injecting pressurized air into the gap between the mold main body and the film to expand the film. The pressure of the pressurized air may be about several atmospheres obtained with a general air compressor. The injected pressurized air leaks to some extent from the end of the film, but not all of it leaks, so the film will swell somewhat due to air pressure. Therefore, the formed resin film can be easily extracted from the mold body.

  When the extracted resin film has a predetermined width, it can be used as it is as a polyimide resin annular seamless molded body. When the resin film is larger than the predetermined width, an unnecessary portion can be cut to obtain a polyimide resin annular seamless molded body. When the resin film has a length that is an integral multiple of the predetermined width, a plurality of polyimide resin annular seamless molded bodies that can be used as they are can be obtained simply by cutting to a predetermined width.

  The thickness of the molded body can be controlled by adjusting the thickness of the resin coating film, and can be, for example, 20 to 1000 μm, particularly 30 to 100 μm.

  In particular, when the resin solution is applied on the release layer on the inner peripheral surface of the mold in the resin coating film forming step, it is preferable to perform the process treatment in the following order. After the resin coating film forming process, a heat drying process and a demolding process of the resin film forming process are performed. Next, the mold reaction step for fitting the unreacted resin film obtained by demolding to another mold outer peripheral surface and the heat reaction process of the resin film formation step are performed, and the demolding step is performed again.

  A resin layer made of another polymer such as a fluororesin layer such as tetrafluoroethylene / perfluoroalkoxyethylene copolymer (PFA) or tetrafluoroethylene / hexafluoropropylene copolymer (FEP) is formed on the surface of the molded body. May be. In that case, after the heat reaction treatment in the resin film forming step and before the demolding step, the mold having the resin film on the outer peripheral surface is covered with a tube made of a predetermined polymer, and heat welding treatment is performed. After performing, it is preferable to perform a demolding process.

<Example 1>
(Manufacture of mold A)
The aluminum mold shown in FIG. 4 having the same structure as the structure shown in FIG. 1A except that the rotation fulcrum giving parts were provided at both ends of the mold main body was manufactured from a bar by cutting. The dimensions were as shown in FIG. The unit of the numerical values shown in FIG. 4 is “mm”.
A silicone-based mold release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the outer periphery of the mold main body 5a to form a silicone resin film (film thickness of about 1 μm) as the release layer 4.
A mold release layer was formed on the outer peripheral surfaces of the end molds 6a and 7a with the same mold release material as the mold main body 5a.

(Resin coating film forming process)
3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) are reacted in N, N-dimethylacetamide to obtain a 22% by weight polyimide precursor. Body solution A was prepared. Carbon black (trade name: Special Black 4, manufactured by Degussa Huls) was mixed with the precursor solution A in a solid mass ratio of 23%, and then dispersed by a jet mill to obtain a resin solution A.
Resin solution A was applied to the outer peripheral surface of the mold in the range shown in FIG. 4 by a ring coating method to form a resin coating film having a thickness of about 500 μm.

(Resin film formation process)
Next, the mold A is leveled and dried at room temperature for 5 minutes while rotating at a rotation fulcrum of the mold body at both ends. I let you. Thereby, a resin coating film having a thickness of about 150 μm was obtained. Next, the mold A was once cooled to room temperature. Thereafter, the mold A was erected vertically and reacted by heating at 200 ° C. for 30 minutes and at 300 ° C. for 30 minutes to form a resin film.

(Demolding process)
After cooling to room temperature, the resin film was cut at the dividing surface, and the mold body was separated from the end mold. When pressurized air with a pressure of 0.5 MPa was injected into the gap between the mold body and the film, the polyimide resin film expanded and could be easily removed. The obtained polyimide resin seamless molded product had dimensions that could be used as it is as an electrophotographic fixing belt.

(Evaluation)
500 molded bodies were manufactured by repeatedly performing a manufacturing process of a molded body including a resin coating film forming process, a resin film forming process, and a demolding process. The molded body was not damaged at all. However, every time 20 molded bodies were manufactured, the end molds 6a and 7a were replaced with those having a refreshed release layer. The same mold body 5a was used continuously.
When 10 arbitrary thicknesses were measured for each of the 10 molded bodies, the difference between the maximum value and the minimum value was 14 μm or less in all the molded bodies, and the film thickness was excellent.

<Example 2>
(Manufacture of mold B)
An aluminum mold having a structure similar to the structure shown in FIG. 1B was manufactured by cutting from a bar material, except that rotation fulcrum imparting portions were provided at both ends of the mold main body. The dimensions were the same as the mold A except that the axial length of the resin solution application region in the end mold 6b was 10 mm and the axial length of the step forming member 8b was 20 mm.
A silicone resin film (film thickness: about 1 μm) was formed as the release layer 4 by applying a silicone release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) to the outer peripheral surface of the mold main body 5b.
The end mold 6b was coated with the same release material as the mold body 5b.
The end mold 7b was formed by forming a Ni film (film thickness 30 μm) as the release layer 4 on the outer peripheral surface by plating.

(Evaluation)
Except that the mold B was used, the same manufacturing steps of the molded body including the resin coating film forming process, the resin film forming process, and the demolding process were performed in the same manner as in Example 1 to manufacture 500 molded bodies. The molded body was not damaged at all. However, every time 50 molded bodies were produced, the end mold 6b was replaced with a refreshed release layer. The same mold body 5b and end mold 7b were used continuously. The end mold 7b is a wire provided in advance after the resin film is molded, after the resin molded film is cut at the mold-matching section before being removed from the mold main body with the resin molded film attached. 15 and the resin molded film is peeled off from the cut portion as a base point.
When 10 arbitrary thicknesses were measured for each of the 10 molded bodies, the difference between the maximum value and the minimum value was 14 μm or less in all the molded bodies, and the film thickness was excellent.

<Example 3>
(Manufacture of mold C)
An aluminum mold having the same structure as the structure shown in FIG. 1C was manufactured by cutting from a bar material, except that rotation fulcrum imparting portions were provided at both ends of the mold main body. The dimensions were the same as the mold A except that the step forming member 8c was provided without providing the end mold 6a at one end of the mold main body.
A silicone resin release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the outer peripheral portion of the mold main body 5c to form a silicone resin film (film thickness: about 1 μm) as the release layer 4.
A mold release layer was formed on the outer peripheral surface of the end mold 7c using the same mold release material as the mold body 5a.

(Evaluation)
Except that the mold C was used, the same manufacturing process of the molded body including the resin coating film forming process, the resin film forming process, and the demolding process as in Example 1 was repeated, and 100 molded bodies were manufactured. The molded body was not damaged at all. However, every time 20 molded bodies were manufactured, the end mold 7c was replaced with a new one. The same mold body 5c was used continuously.
When 10 arbitrary thicknesses were measured for each of the 10 molded bodies, the difference between the maximum value and the minimum value was 13 μm or less for all the molded bodies, and the film thickness was excellent.

<Comparative Example 1>
(Manufacture of mold D)
A mold similar to the mold A was manufactured by the same method as the mold A except that it did not have a dividing surface.
A silicone-based mold release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the outer peripheral surface of the mold to form a silicone resin film (film thickness of about 1 μm) as a release layer.

(Evaluation)
Except that the mold D was used, the manufacturing process of the molded body consisting of the resin coating film forming process, the resin film forming process and the demolding process similar to those in Example 1 was repeated. During production, breakage occurred when the molded body was demolded.

<Example 4>
(Manufacture of mold E)
A mold E was manufactured in the same manner as the mold A manufacturing method, except that the rotation fulcrum imparting portions were not provided at both ends of the mold main body.
Except that the mold E was used, the same manufacturing process of the molded body including the resin coating film forming process, the resin film forming process, and the demolding process was repeated, and 500 molded bodies were manufactured. The rotation in the resin film forming step was performed using the hollow portion of the end molds at both ends as a fulcrum. The molded body was not damaged at all. However, every time 20 molded bodies were manufactured, the end molds at both ends were replaced with new ones.

(Evaluation)
When the thicknesses of 10 arbitrary points were measured for each of the 10 molded bodies, the difference between the maximum value and the minimum value was 24 μm for all the molded bodies.

  The mold of the present invention is useful for producing an annular seamless molded body that can be used as a fixing belt, an intermediate transfer belt, a contact charging belt or the like of an image forming apparatus.

(A)-(C) are schematic block diagrams which show one Embodiment of the metal mold | die of this invention. It is a schematic block diagram which shows one Embodiment of the metal mold | die of this invention. It is a schematic outline drawing which shows one Embodiment of the edge part type | mold in the metal mold | die of this invention. FIG. 3 is a view showing dimensions of a mold manufactured in Example 1.

Explanation of symbols

  1: Mold, 2: Dividing surface, 3: Resin coating (resin solution), 4: Release layer, 5: 5a: 5b: 5c: 5d: Mold body, 6: 6a: 6b: 6d: End Mold: 7: 7a: 7b: 7c: 7d: End mold, 8: 8b: 8c: Step forming member, 13: Resin solution application region, 14: Recess, 15: Movable member.

Claims (12)

A mold for producing an annular seamless molded body by applying a resin solution for a molded body on a release layer having an outer peripheral surface or an inner peripheral surface,
A mold having a split surface at at least one location in a resin solution application region. The dividing surface is in the resin solution application region of the mold and exists at at least one end of the mold,
The mold according to claim 1, further comprising: a mold main body part and an end part mold detachably coupled to at least one end of the mold main body part.   3. The mold according to claim 2, wherein the axial length of the resin solution application region in the mold body is equal to or greater than a predetermined width of the annular seamless molded body.   The mold according to claim 2 or 3, wherein the axial length of the resin solution application region in the mold body is equal to a predetermined width of the annular seamless molded body.   The mold according to any one of claims 2 to 4, wherein the mold release layer of the mold main body and the mold release layer of the end mold are formed of the same or different materials.   The mold according to any one of claims 2 to 5, wherein the mold body and the end mold are coupled by engagement, and a member that is engaged on the inside has a higher linear expansion coefficient than a member that is engaged on the outside. .   The mold according to any one of claims 2 to 6, wherein the mold body has a rotation fulcrum on the axis of the mold body.   The mold according to any one of claims 2 to 7, wherein the end mold has a step difference higher than the surface of the end mold on the resin solution application surface.   The metal mold | die in any one of Claims 2-8 in which an edge part type | mold has a recessed part in the resin solution application | coating area | region of this edge part type | mold.   The metal mold according to claim 9, wherein the end mold has a movable member integrated with the end mold in the recess.   The manufacturing apparatus of the cyclic | annular seamless molded object provided with the metal mold | die in any one of Claims 1-10. A resin coating film forming step of forming a resin coating film by applying a resin solution for an annular seamless molded body on the release layer of the mold according to claim 1;
A method for producing an annular seamless molded body comprising: a resin film forming step of heating a resin coating film to form a resin film; and a demolding process of peeling the resin film from a mold.

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