JP2009072924A - Method for producing multilayer resin belt and multilayer resin belt obtained by this method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a multilayer resin belt which can obtain the belt formed by stacking a plurality of resin layers in high thickness precision by using extrusion molding while reducing the unevenness of the surface caused by foreign substances and the multilayer resin belt obtained by this method. <P>SOLUTION: In the method for producing the multilayer resin belt having a lamination structure comprising at least two resin layers, at least two kinds of molten resin materials constituting each resin layer, through at least two annular passages 4A and 4B formed independently in a molding die 10 by a mandrel 1, an intermediate die ring 2, and an outside die ring 3, after being joined together, are extruded from a die slit 6 to form the lamination structure. External circumferential force is applied to at least one kind of the molten resin material in the annular passages to make the molten resin material flow forcibly in the annular passage 4B, and in the joining part 5 of at least two kinds of the molten resin materials, no external circumferential force is applied to the joining molten resin materials. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a multilayer resin belt and a multilayer resin belt obtained thereby (hereinafter also simply referred to as “manufacturing method” and “belt”). The present invention relates to a method for producing a multilayer resin belt used as an intermediate transfer belt, a transfer conveyance belt, or the like in an electrostatic recording process in a recording apparatus or the like, and a multilayer resin belt obtained thereby.

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

  In such an electrostatic recording process, when transferring a toner image to a recording medium such as paper, the toner image is temporarily held on its surface (intermediate transfer method), or the recording medium is A belt-like member made of rubber having a semiconductive resin film or a fiber reinforcement is used for transferring the toner image directly to the photosensitive member (transfer conveying method). Among these, as a method for producing a resin film belt made of a resin film, a technique by extrusion molding using an annular die is conventionally known.

  As an improved technique related to the extrusion of such a belt, for example, in Patent Document 1, a molten resin material is extruded from a die slit through an annular passage between a mandrel of a molding die and an outer cylinder die ring, and a thin resin wall When molding a tube, the external force in the circumferential direction is exerted on the molten resin material in the annular passage, and the molten resin material is forced to flow in the annular passage, so that foreign matters are mixed in the thin resin tube to be molded. A method of forming a thin resin tube with improved number and thickness accuracy is disclosed.

  Further, in Patent Document 2, at least one of an inner die ring and an outer die ring is rotatably arranged, and a plurality of spiral flow paths whose depth gradually decreases on the inner die ring side between these die rings. A distribution groove in which a plurality of molten resin flows are provided from the inner die ring to the inner die ring while rotating at least one of the die rings in the plurality of spiral flow channel grooves of the spiral die formed with grooves. Through each of the molten resin flows through the spiral channel grooves before the individual resin flows through the spiral channel grooves to form a uniform cylindrical flow in the die axis direction. A method of manufacturing a resin laminate is disclosed in which a laminated cylindrical body in which a plurality of resins are obliquely laminated in a circumferential cross section is obtained by laminating in a certain order as a flow.

Further, Patent Document 3 discloses a multilayer that achieves polymer orientation in the tube circumferential direction and can improve pushability, torque transmission, followability, kink resistance, and the like without using a special polymer such as a liquid crystal polymer. For the purpose of providing a tubular body, two or more polymer inlets, a merging portion downstream in the extrusion direction, a die body having a branch path therein, a mandrel disposed through the die body, and a die body And a die disposed concentrically with the mandrel at the downstream end in the extrusion direction, and the outer peripheral surface of the mandrel and the inner peripheral surface of the die form a flow path for the merged polymer in the space of the die, There is disclosed a laminated tubular body extrusion die in which at least one of a mandrel and a die is configured to be rotatable with an extrusion direction as an axial direction. Furthermore, in Patent Document 4, a mandrel having a spiral groove on the outer surface is fitted inside the die body, and is within the range of a part of the die cylinder part that forms the inner surface of the die body, and at the beginning of the spiral groove. There is disclosed a spiral die in which a rotating ring having a desired width dimension is rotatably mounted along the outer peripheral surface of the spiral groove at a portion corresponding to the end portion to the end portion.
Japanese Patent Laying-Open No. 2005-53031 (Claims etc.) Japanese Patent Laid-Open No. 10-29237 (Claims etc.) JP 2003-251680 A (Claims etc.) JP 2004-330698 A (Claims etc.)

  Resin film belts used in image forming apparatuses are required to have no irregularities due to foreign matters on the belt surface and to have high thickness accuracy. On the other hand, there is a demand for a high-performance belt that satisfies all the various belt performances such as flame retardancy, surface gloss, and image characteristics. A belt composed of one type of resin composition can simultaneously perform these functions. It has become difficult to achieve. Therefore, recently, attempts have been made to achieve higher functionality by making the belt multi-layered and separating each function into each layer.

  When manufacturing such a multilayered belt by extrusion molding, the technique disclosed in Patent Document 1 can provide a high-quality belt with respect to unevenness and thickness accuracy due to foreign matter, but can cope with multilayering. It wasn't. Moreover, in the technique disclosed in Patent Document 2, it is possible to stack a plurality of types of resin compositions over the types of resin compositions, but it is difficult to control the thickness accuracy of each layer. Furthermore, the technique disclosed in Patent Document 3 is to rotate a mandrel or a die after joining the material of each layer in order to obtain a laminated tubular body in which the polymer is oriented. There is no consideration for improvement.

  Therefore, an object of the present invention is to provide a method for producing a multilayer resin belt capable of obtaining a belt constituted by laminating a plurality of resin layers with high thickness accuracy while reducing surface irregularities due to foreign matter using extrusion formation, and The object is to provide a multilayer resin belt obtained thereby.

  As a result of intensive studies, the inventor has found that when a multilayer resin belt is formed by extrusion, a residence portion may occur in each annular passage in which the resin material of each layer flows independently in the molding die. It has been found that the deteriorated resin material causes the generation of foreign matters. As a result of further study, the present inventor has applied an external force to the annular passage in the molding die to prevent the occurrence of a staying portion, and does not apply an external force to the joining portion of each layer, thereby deteriorating the resin material. As a result, it has been found that problems such as the generation of foreign matter can be prevented and the thickness accuracy of each layer and the whole can be improved, and the present invention has been completed.

That is, the method for producing a multilayer resin belt of the present invention is a method for producing a multilayer resin belt having a laminated structure composed of two or more resin layers, wherein two or more types of molten resin materials constituting each resin layer are obtained. The laminated structure is formed by extruding from a die slit after joining through two or more annular passages provided independently by a mandrel, an intermediate die ring, and an outer die ring in a molding die. In the method for producing a multilayer resin belt,
A circumferential external force is exerted on one or more of the molten resin materials in the annular passage to force the one or more molten resin materials to flow in the annular passage, and the two or more of the molten resins The material joining portion is characterized in that the external force in the circumferential direction is not exerted on the molten resin material to be joined.

  In the present invention, a part of one or more of the mandrel, the intermediate die ring, and the outer die ring is rotationally displaced around a central axis to force the one or more types of molten resin material in the annular passage. It is preferable to make it flow. Further, one or more of the mandrel, the intermediate die ring and the outer die ring are provided with a spiral guide groove from the inlet of the annular passage toward the joining portion, and the mandrel, the intermediate die ring and the outer die ring are provided. It is also preferable to rotate and displace a part of one or more of them around the central axis in the same direction as or opposite to the extending direction of the guide groove. In the present invention, preferably, a resin belt having a laminated structure composed of two resin layers can be produced using two types of molten resin materials.

  The multilayer resin belt of the present invention is manufactured by the manufacturing method of the present invention.

  According to the present invention, a multilayer resin that can obtain a belt constituted by laminating a plurality of resin layers with high thickness accuracy while reducing surface irregularities due to foreign substances by using extrusion forming because of the above configuration. A belt manufacturing method can be realized, and this makes it possible to obtain a multilayer resin belt having excellent thickness accuracy of each layer and the whole and a small number of foreign matters mixed therein.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
FIG. 1 shows a schematic partial cross-sectional view of a molding die used in a method for producing a multilayer resin belt according to a preferred embodiment of the present invention. The illustrated forming die 10 is for manufacturing a resin belt having a laminated structure composed of two resin layers using two types of molten resin materials.

  The method for producing a multilayer resin belt according to the present invention is a method for producing a multilayer resin belt having a laminated structure composed of two or more resin layers. Two or more (2 in the illustrated example) annular passages 4A and 4B provided independently by the mandrel 1, the intermediate die ring 2 and the outer die ring 3 in the molding die 10 with the above molten resin material. Then, after making it merge in the junction part 5, a laminated structure is formed by extruding from the die slit 6. FIG.

  In the illustrated forming die 10, annular passages 4 </ b> A and 4 </ b> B are defined at two locations between the mandrel 1 and the intermediate die ring 2 and between the intermediate die ring 2 and the outer die ring 3. A die slit 6 is formed at the downstream end portion of the annular passages 4A and 4B via the combined flow path 5. At the time of extrusion molding, two types of molten resin materials are supplied from the material inlet 9A provided at the upper center of the mandrel 1 and the material inlet 9B provided at the outer peripheral surface of the molding die 10, and the outer peripheral surface of the mandrel 1 and The flow is branched to the material outlets 7A and 7B provided between the intermediate die ring 2 and the outer die ring 3, and flows into the annular passages 4A and 4B through the outlets 7A and 7B. The molten resin material that has flowed into the annular passages 4A and 4B is formed on the outer peripheral surface of the mandrel 1 and the outer peripheral surface of the intermediate die ring 2, and extends in a spiral manner from the outlets 7A and 7B to the die slit 6 respectively. It is guided by the grooves 8A and 8B and flows down in the annular passages 4A and 4B.

  In the present invention, a circumferential external force is applied to one or more types of molten resin materials in the two or more annular passages to force the one or more types of molten resin materials in the annular passages. Let it flow. Thereby, since a large shearing force can be applied to the molten resin material in the annular passage, the molten resin material can be smoothly merged and flowed down without being retained in the annular passage and extruded from the die slit. . Further, as a result, it is possible to prevent the occurrence of a weld line accompanying the merging of materials in each annular passage, and to eliminate the possibility that the material deteriorated due to the retention of the molten resin material is mixed in the belt. As a result, it is possible to improve the thickness accuracy of the entire belt and to obtain a multilayer resin belt in which foreign matter is not mixed, that is, the occurrence of surface irregularities is small. Note that, as in Patent Document 3, even if an external force is applied after the materials of the layers are joined, staying in the annular passage cannot be prevented, so that the effect of improving the thickness accuracy and surface property cannot be obtained.

  In the present invention, among the two or more types of molten resin materials in the annular passage, it is sufficient that at least one type of molten resin material is forcibly fluidized. More effective effects can be obtained by forcibly flowing all of the two or more molten resin materials.

  Further, in the present invention, it is important that the joining portion 5 of the two or more kinds of molten resin materials does not exert an external force in the circumferential direction on the molten resin materials to be joined. When an external force in the circumferential direction is applied to the molten resin material to be joined at the joining portion 5, the interface between the layers becomes non-uniform after joining and unevenness is likely to occur in the thickness of each layer.

  In the present invention, the forcible flow of the molten resin material in the annular passages causes a central axis of one or more parts of the mandrel 1, the intermediate die ring 2 and the outer die ring 3 that define each annular passage. Can be performed by applying a circumferential external force to the molten resin material in the annular passage. This rotational displacement may be any one that can force the molten resin material in one or more annular passages to flow, and therefore, of the mandrels, intermediate die rings, and outer die rings that form both sides of at least one annular passage. A part of at least one side may be rotationally displaced.

  For example, in the case of the forming die 10 for a two-layer belt shown in FIG. 1, the movable portion 3a provided in a part of the outer die ring 3 is rotationally displaced around the central axis, thereby melting the annular passage 4B. Only the resin material can be forced to flow while avoiding the junction 5.

  When some of these mandrels and the like are rotationally displaced, it is preferable to perform rotational displacement in the vicinity of the outlet 7B of the molten resin material to the annular passage 4B as shown in the figure. As a result, the molten resin material that has flowed into the annular passage 4B from the outlet 7B can flow smoothly without being retained in the vicinity thereof, which is more effective. In a forming die having an annular passage as shown in the figure, the material outlets are usually provided at a plurality of locations, usually about four, at equal intervals in the circumferential direction.

  Here, in the present invention, the rotational displacement of the mandrel or the like may be any rotational displacement of the mandrel or the like around the central axis, and is not limited to the case where the mandrel or the like is continuously rotated in one direction at a constant speed. The case of repeating in the reverse direction is also included. The rotational speed of the rotational displacement of the mandrel or the like in the present invention is, for example, 0.1 to 10 rpm although it depends on the viscosity of the molten resin material.

  As shown in the figure, in the forming die, for each of the annular passages 4A and 4B, one or more of the mandrel 1, the intermediate die ring 2 and the outer die ring 3 are connected to the material inlet 7A, which is the inlet of the annular passage. When the spiral guide grooves 8A and 8B from 7B to the merging portion 5 are provided, it is preferable that the rotational displacement of the mandrel or the like is performed in the direction opposite to the extending direction of the guide grooves. The effect of the present invention can be obtained even if the guide groove is rotationally displaced in the same direction as the extending direction of the guide groove, but by making the direction opposite to the extending direction, the shearing force acting on the molten resin material can be further enhanced. It is possible to stir the molten resin materials flowing out from the respective outlets more effectively.

  Furthermore, in the present invention, the surface of a part of the movable part such as a mandrel that is rotationally displaced, that is, the surface that is in contact with the molten resin material, for example, the surface roughness is made rougher than the surface of the non-movable part. It is preferable to make the restraining force of the molten resin material larger than the surface of the non-movable part, for example, by lowering. Thereby, the forcing force with respect to the flow of the molten resin material can be further increased.

  As described above, the mandrel 1 used in the present invention is provided with the inlet 9A for supplying the molten resin material supplied from the extruder at the upper center and the material outlet 7A on the outer peripheral surface. Further, on the outer peripheral surface, a guide groove 8A extending from the outlet 7A toward the die slit 6 and extending spirally at an equal helical winding angle is provided. The inlet 9 </ b> A and the outlet 7 </ b> A are connected via a flow path 11 </ b> A that penetrates the inside of the mandrel 1.

  Further, the intermediate die ring 2 is disposed between the mandrel 1 and the outer die ring 3 to partition the annular passages 4A and 4B of the molten resin material. In the case of multilayer extrusion of three or more layers, Two or more layers of the intermediate die ring may be disposed to form an annular passage corresponding to each molten resin material. In the example shown in the figure, a guide groove 8 </ b> B is provided on the inner peripheral surface of the intermediate die ring 2 so as to extend from the outlet 7 </ b> B to the die slit 6 and spirally with an equal spiral angle.

  In the illustrated mandrel 1 and intermediate die ring 2, the guide grooves 8 </ b> A and 8 </ b> B are terminated at a certain distance from the lower ends of the mandrel 1 and intermediate die ring 2, and the mandrel 1 and intermediate die ring 2. The guide groove forming area defines annular passages 4A and 4B of the molten resin material.

  In the illustrated example, an inlet 9B for supplying the molten resin material supplied from the extruder is provided on the outer peripheral surface of the molding die 10, and between the intermediate die ring 2 and the outer die ring 3. A material outlet 7B is provided, and these inlet 9B and outlet 7B are connected via a flow path 11B. Reference numeral 12 in the figure denotes an adjustment ring, which is formed by adjusting the distance between the die slits 6 by deforming or moving the adjustment ring using an adjustment bolt (not shown) provided on the adjustment ring. The thickness deviation of the belt can be adjusted.

  Here, in any of the mandrel, the intermediate die ring, and the outer die ring, when the movable portion that is rotationally displaced is formed, it is considered that the molten resin material enters the joint portion between the movable portion and the fixed portion. However, if this joint portion is a complete liquid-tight seal with respect to the outside of the die, it becomes impossible to prevent the molten resin material that has entered the joint portion and has been thermally deteriorated from flowing into the annular passage again. Therefore, in this case, without completely sealing between the fixed part and the rotating part, heat deterioration or the like was caused by allowing the molten resin material that has entered the joint part to exude outwardly from the die. It is preferable to sufficiently remove the possibility of mixing the molten resin material into the product belt.

  When a multilayer resin belt is manufactured using the molding die 10 shown in the drawing, each molten resin material melted and extruded in an extruder (not shown) is supplied to the inlet 9A of the mandrel 1 via, for example, a constant volume pump. And it supplies from the inflow port 9B of the shaping | molding die 10 outer peripheral surface, and it branches from each outflow port 7A, 7B, Preferably it is substantially equally branched and flows out into annular channel | path 4A, 4B. At this time, an external force in the circumferential direction is exerted on the molten resin material in the annular passage 4B by rotating the movable portion 3a of the outer die ring 3 at a predetermined speed via the drive gear 14 connected to the motor 13. Thereby, a shearing force is applied to the molten resin material in the annular passage 4B, and the entire molten resin material can be forced to flow in the rotation direction in the annular passage 4B. For this reason, the molten resin material that has flowed out from the outlet is sufficiently agitated without leaving the stagnation, so that there is no risk of mixing of deteriorated materials due to stagnation, and the molten resin material that has flowed out from each outlet It is possible to reliably prevent the occurrence of a weld line due to the merge.

  As described above, after the entire molten resin material is sufficiently forced to flow, all the molten resin materials constituting each layer flow down to the lower ends of the annular passages 4A and 4B based on the action of the extrusion pressure on each. The multilayer resin belt having a predetermined shape and size can be formed by extruding from the die slit 6 through the junction portion 5. As described above, the multilayer resin belt molded in this way has no retention of the molten resin material in the molding die, and there is no formation of a weld line due to the fusion of the molten resin materials in each annular passage. For this reason, it is possible to sufficiently protect against variation in thickness caused by mixing of a material that has undergone thermal degradation or the like and the presence of a weld line.

  FIG. 2 shows a schematic partial cross-sectional view of a forming die according to another embodiment of the present invention. The illustrated molding die 20 is also for manufacturing a resin belt having a laminated structure composed of two resin layers using two types of molten resin materials, and a movable part provided in a part of the intermediate die ring 22. 1 is different from the molding die of FIG. 1 in that the molten resin material in the annular passage 24A is forced to flow by rotationally displacing the 22a around the central axis.

  In the illustrated forming die 20, annular passages 24 </ b> A and 24 </ b> B are defined at two locations between the mandrel 21 and the intermediate die ring 22 and between the intermediate die ring 22 and the outer die ring 23. A die slit 26 is formed at the end portion via the joint channel 25. At the time of extrusion molding, two kinds of molten resin materials are supplied from a material inlet 29A provided at the upper center of the mandrel 21 and a material inlet 29B provided at the outer peripheral surface of the outer die ring 23, so that the outer peripheral surface of the mandrel 21 is supplied. The flow is branched to the material outlets 27A and 27B provided on the inner peripheral surface of the outer die ring 23, and flows into the annular passages 24A and 24B through the outlets 27A and 27B. The molten resin material flowing into the annular passages 24A and 24B is formed on the outer peripheral surface of the mandrel 21 and the inner peripheral surface of the outer die ring 23, respectively, and extends spirally from the outlets 27A and 27B toward the die slit 26. It is guided by the guide grooves 28A and 28B and flows down in the annular passages 24A and 24B.

  FIG. 3 is a schematic partial cross-sectional view showing a forming die according to still another embodiment of the present invention. The illustrated molding die 30 is also for manufacturing a resin belt having a laminated structure composed of two resin layers using two types of molten resin materials. In this forming die 30, the movable part 32a provided in a part of the intermediate die ring 32 and the movable part 33a provided in a part of the outer die ring 33 are rotationally displaced about the central axis, respectively, so that an annular passage is formed. Each of the molten resin materials in 34A and 34B is forced to flow.

  In the illustrated forming die 30, annular passages 34 </ b> A and 34 </ b> B are defined at two locations between the mandrel 31 and the intermediate die ring 32 and between the intermediate die ring 32 and the outer die ring 33, and the downstream side thereof. A die slit 36 is formed at the end portion via the joint channel 35. At the time of extrusion molding, two types of molten resin materials are supplied from the material inlet 39A provided at the upper center of the mandrel 31 and the material inlet 39B provided at the outer peripheral surface of the outer die ring 33, and the outer peripheral surface of the mandrel 31 The flow is branched to the material outlets 37A and 37B provided on the inner peripheral surface of the outer die ring 33, and flows into the annular passages 34A and 34B through the outlets 37A and 37B. The molten resin material that has flowed into the annular passages 34A and 34B is formed on the outer peripheral surface of the mandrel 31 and the inner peripheral surface of the outer die ring 33, respectively, and extends spirally from the outlets 37A and 37B toward the die slit 36. It is guided by the guide grooves 38A and 38B and flows down in the annular passages 34A and 34B. In the figure, reference numerals 13A and 13B indicate motors, and reference numerals 14A and 14B indicate drive gears, respectively.

  The multilayer resin belt of the present invention only needs to be manufactured by the above-described manufacturing method of the present invention, and this can improve the thickness accuracy while reducing surface irregularities due to foreign matters. There are no particular restrictions on the configuration of each layer or the details of the belt formulation.

Hereinafter, the present invention will be described in more detail with reference to examples.
<Example>
A resin belt having a two-layer structure was extruded using a molding die having a schematic shape shown in FIG. The composition of each layer is as shown in Table 1 below.

  As the compounding material for the inner layer and the outer layer, those obtained by mixing each compounding component at the compounding ratio shown in Table 1 and kneading at 250 ° C. with a φ30 mm twin screw extruder were used. Thereafter, the blended materials were melted using a φ30 mm single screw extruder for the inner layer and the φ25 mm single screw extruder for the outer layer, and a belt was formed using the forming die 30, the cooling mandrel and the take-up machine shown in FIG. 3. The extruder and the forming die temperature were each set to 260 ° C., and the belt was formed with a diameter of 150 mm and a total thickness of 100 μm by adjusting the extrusion amount ratio of the inner layer to the outer layer to be 8: 2. When forming the belt, the movable part 32a provided in a part of the intermediate die ring 32 and the movable part 33a provided in a part of the outer die ring 33 are rotated at a rotational speed of 2 rpm in the same direction as the extending direction of the spiral guide groove. Rotationally displaced around the central axis in the direction or reverse direction. The rotation direction of the inner layer and the outer layer was the same. The flow rate of the molten resin material was 4 kg / hr for both the inner layer and the outer layer.

<Comparative example>
A resin belt was molded under the same conditions as in the example except that the mandrel and the like were not rotationally displaced.

<Evaluation>
After flowing the molten resin material for 30 minutes, the following items were evaluated. The results are shown in Table 2 below.
(1) Presence / absence of weld line: Evaluated visually.
(2) Number of contaminants: The number of irregularities due to contaminants per 1 m of belt length was measured.
(3) Maximum-minimum total belt thickness: The total thickness in the belt circumferential direction was measured with a contact-type thickness measuring device TOF-4R (manufactured by Yamabun Electric Co., Ltd.).
(4) Maximum-minimum outer layer thickness: Sections were cut out at 8 locations in the circumferential direction with a sharp knife and measured with a microscope (VHX-200 manufactured by Keyence Corporation).

  As shown in Table 2 above, the mandrel and the like were rotated and displaced to exert an external force in the circumferential direction on the molten resin material in each annular passage, and the molten resin material was manufactured while forcibly flowing in the annular passage. In the belt, it was confirmed that the number of contaminants can be greatly reduced and the thickness accuracy is improved as compared with the belt of the comparative example manufactured without performing the rotational displacement of the mandrel.

It is a general | schematic fragmentary sectional view which shows the shaping | molding die used for the manufacturing method of the multilayer resin belt which concerns on one suitable embodiment of this invention. It is a general | schematic fragmentary sectional view which shows the shaping | molding die used for the manufacturing method of the multilayer resin belt which concerns on other suitable embodiment of this invention. It is a general | schematic fragmentary sectional view which shows the shaping | molding die used for the manufacturing method of the multilayer resin belt which concerns on other suitable embodiment of this invention.

Explanation of symbols

1, 21, 31 Mandrels 2, 22, 32 Intermediate die rings 3, 23, 33 Outer die rings 3a, 22a, 32a, 33a Movable parts 4A, 4B, 24A, 24B, 34A, 34B Annular passages 5, 25, 35 Portions 6, 26, 36 Die slits 7A, 7B, 27A, 27B, 37A, 37B Material outlet 8A, 8B, 28A, 28B, 38A, 38B Guide grooves 9A, 9B, 29A, 29B, 39A, 39B Material inlet 10 , 20, 30 Molding dies 11A, 11B Flow path 12 Adjustment ring 13, 13A, 13B Motor 14, 14A, 14B Drive gear

Claims (5)

A method for producing a multilayer resin belt having a laminated structure comprising two or more resin layers, wherein two or more types of molten resin materials constituting each resin layer are formed in a molding die, a mandrel, an intermediate die ring, and an outer In a method for producing a multilayer resin belt for forming the laminated structure by extruding from a die slit after joining through two or more annular passages independently provided by a die ring,
A circumferential external force is exerted on one or more of the molten resin materials in the annular passage to force the one or more molten resin materials to flow in the annular passage, and the two or more of the molten resins A method for producing a multilayer resin belt, wherein an external force in the circumferential direction is not exerted on the molten resin material to be joined at a joining portion of the materials.   2. A part of one or more of the mandrel, intermediate die ring and outer die ring is rotationally displaced about a central axis to force the one or more types of molten resin material to flow in the annular passage. The manufacturing method of the multilayer resin belt of description.   One or more of the mandrel, the intermediate die ring, and the outer die ring are provided with a spiral guide groove from the inlet of the annular passage toward the joining portion, and the mandrel, the intermediate die ring, and the outer die ring. 3. The method for producing a multilayer resin belt according to claim 1, wherein at least one part of the belt is rotationally displaced about the central axis in the same direction as or in the opposite direction to the extending direction of the guide groove.   The manufacturing method of the multilayer resin belt as described in any one of Claims 1-3 which manufactures the resin belt which has a laminated structure which consists of two resin layers using two types of molten resin materials.   A multilayer resin belt manufactured by the manufacturing method according to claim 1.

Images