Method for manufacturing extruded articles

Abstract

To provide a method for producing an extrusion molded product which contributes to lowering specific gravity and saving resources, and which makes it easier to obtain desired surface smoothness and mechanical properties.SOLUTION: An extrusion molded product A1 formed by extruding at least a foamable TPE composition and a non-foamable TPE composition and foaming a foaming agent by the extrusion molding includes: a mounting base 11 made of the foamable TPE composition or the non-foamable TPE composition and freely mountable to any specified position on the body of an automobile; an elastic part 12 made of the foamable TPE composition and capable of elastic contact with a nearby position adjacent to the specified position in the automobile; and coating layers 13, 14 made of the non-foamable TPE composition and applied to coat the surface of the elastic part 12. The foamable TPE composition and the non-foamable TPE composition are each composed of a rubber component and a thermoplastic resin component, and the ratio of the rubber component to the thermoplastic resin component is within a range of 70 / 30 to 60 / 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing extruded articles, and more particularly to a technology applicable to, for example, weatherstrips attached to the body of an automobile. [Background technology]

[0002] For example, molded products such as weatherstrips attached to the body of an automobile (weatherstrips applied around the engine compartment or on doors, etc.) are required to have a lower specific gravity and be resource-efficient (easier to recycle, lower cost) in order to contribute to recent global environmental measures (for example, improving fuel efficiency and recycling in automobiles).

[0003] One example of a method for manufacturing molded articles such as weatherstrips is to apply a foaming composition (hereinafter simply referred to as a foaming rubber composition) made by blending a foaming agent with a rubber material, and then extrude the foaming rubber composition to create foam. While molded articles produced by such a method (hereinafter appropriately referred to as foamed rubber molded articles) may not only have a lower specific gravity but also potentially reduce costs by reducing the amount of rubber material consumed, the rubber material itself may sometimes be a factor that hinders the desired recycling.

[0004] Another example involves using a foamed composition (hereinafter simply referred to as a foamed TPE composition) made by compounding a foaming agent with a thermoplastic elastomer (hereinafter simply referred to as TPE) as a substitute for the foamed rubber composition, and then extruding the foamed TPE composition to create a foamed product. With a molded product made by such a method (hereinafter simply referred to as a foamed TPE molded product), the proportion of rubber components is reduced compared to a simple foamed rubber molded product, which may make recycling easier. However, the surface roughness of the foamed TPE molded product may increase (for example, so-called fraying may occur), which may result in a decrease in the various properties (e.g., sealing performance) and appearance required for weatherstrips.

[0005] Patent Document 1 discloses a method of extruding a TPE foam composition through a die heated to 200°C or higher, thereby smoothing the surface of the TPE foam molded body by heat treatment simultaneously with the extrusion molding. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 3143609 [Overview of the project] [Problems that the invention aims to solve]

[0007] In the case of TPE foam molded articles, the specific gravity decreases as the foaming ratio of the TPE foam molded article increases, but this also reduces the proportion of thermoplastic resin components in the TPE foam molded article, which may lead to a decrease in mechanical properties (tensile strength, lapse resistance, etc.).

[0008] Furthermore, in the case of a method in which the surface of the TPE foam molded body is heat-treated simultaneously with extrusion molding, as described in Patent Document 1, there is a possibility that the surface of the TPE foam molded body may be heated unevenly. As a result, the surface smoothness of the TPE foam molded body may be reduced, and the desired properties and appearance required for weatherstrips may not be obtained.

[0009] The present invention has been made in view of the aforementioned technical problems, and aims to provide a method for manufacturing an extruded article that contributes to lowering specific gravity, conserving resources, and making it easier to obtain desired surface smoothness and mechanical properties. [Means for solving the problem]

[0010] The method for manufacturing an extruded article according to this invention can contribute to solving the above-mentioned problems, and in one embodiment thereof, an extruded article is formed by extruding a foaming thermoplastic elastomer composition containing a foaming agent and a non-foaming thermoplastic elastomer composition not containing the foaming agent, and by a molding step in which the foaming agent is foamed by the extrusion molding, the extruded article comprises: a mounting base made of the foaming thermoplastic elastomer composition or the non-foaming thermoplastic elastomer composition, having a long shape in the extrusion direction of the extrusion molding, and being attachable to any position on the body of an automobile; an elastic part made of the foaming thermoplastic elastomer composition, having a long hollow part in the extrusion direction, and being elastically contactable with a proximity position close to the arbitrary position on the automobile; an outer peripheral coating layer made of the non-foaming thermoplastic elastomer composition and covering the outer peripheral surface of the elastic part; and an inner peripheral coating layer made of the non-foaming thermoplastic elastomer composition and covering the inner peripheral surface of the elastic part. Furthermore, the foamed thermoplastic elastomer composition and the non-foamed thermoplastic elastomer composition are each composed of a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component is in the range of 70 / 30 to 60 / 40.

[0011] In another embodiment, an extruded molded body is formed by extruding a foaming thermoplastic elastomer composition containing a foaming agent and a non-foaming thermoplastic elastomer composition not containing the foaming agent, thereby foaming the foaming agent through the extrusion molding process. The extruded body comprises: a mounting base made of the foaming thermoplastic elastomer composition or the non-foaming thermoplastic elastomer composition, having an elongated shape in the extrusion direction of the extrusion molding and being attachable to any position on the body of an automobile; an elastic portion made of the foaming thermoplastic elastomer composition, having an elongated shape in the extrusion direction and protruding from the mounting base, and being elastically contactable with a proximity position close to the arbitrary position on the automobile; an elastic contact side coating layer made of the non-foaming thermoplastic elastomer composition, covering the elastic contact side of the elastic portion on the proximity position side; and a non-elastic contact side coating layer made of the non-foaming thermoplastic elastomer composition, covering the non-elastic side of the elastic portion on the opposite side of the proximity position side. Furthermore, the foamed thermoplastic elastomer composition and the non-foamed thermoplastic elastomer composition are each composed of a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component is in the range of 70 / 30 to 60 / 40.

[0012] The elastic portion, the outer peripheral coating layer, and the inner peripheral coating layer may be characterized in that they are formed by co-extruding the foamed thermoplastic elastomer composition and the non-foamed thermoplastic elastomer composition in the molding process.

[0013] Furthermore, the elastic portion and the inner circumferential coating layer may be formed by co-extruding the foamed thermoplastic elastomer composition and the non-foamed thermoplastic elastomer composition in the molding process, and the outer circumferential coating layer may be formed by laminating a long strip-shaped film made of the non-foamed thermoplastic elastomer composition onto the outer circumferential surface of the elastic portion.

[0014] Further, the elastic part, the elastic-contact-side coating layer, and the non-elastic-contact-side coating layer may be formed by co-extruding the foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition in the molding step.

[0015] Further, the elastic-contact-side coating layer and the non-elastic-contact-side coating layer may be formed by laminating a long-strip-shaped film made of the non-foaming thermoplastic elastomer composition on the elastic-contact side surface and the non-elastic-contact side surface of the elastic part in the molding step, respectively.

[0016] Further, the molding step may include a discharging step of discharging the foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition through a die and performing extrusion molding, and a cooling step of cooling the extruded molded body extruded from the die by the take-up machine while pulling and moving it in the extrusion direction. The die has a foaming discharge port for discharging the foaming thermoplastic elastomer composition in the extrusion direction and a non-foaming discharge port for discharging the non-foaming thermoplastic elastomer composition for forming the coating layer in the extrusion direction. The dimension corresponding to the layer thickness direction of the coating layer in the non-foaming discharge port may be set within the range of 1.2 times to 2 times the dimension in the layer thickness direction of the coating layer after cooling.

[0017] Further, the dimension in the layer thickness direction of the coating layer may be within the range of 50 μm to 500 μm.

[0018] Further, the cell diameter of the foam cells formed in the extruded molded body by the foaming of the foaming agent may be within the range of 50 μm to 100 μm.

[0019] Further, the elastic part may have a specific gravity within the range of 0.4 to 0.8.

[0020] Further, the thermoplastic elastomer composition may be blended with any one of TPO, TPS, and TPV.

[0021] Also, the extrusion temperature of the extrusion molding may be within the range of 195°C to 220°C.

[0022] Also, the foaming agent may be any one of microcapsules, organic foaming agents, and supercritical fluid foaming agents.

Advantages of the Invention

[0023] According to the present invention, it is possible to contribute to weight reduction and resource saving, and to easily obtain desired surface smoothness and mechanical properties.

Brief Description of the Drawings

[0024] [Figure 1] Schematic configuration diagram (radial cross-sectional view) for explaining the extruded body A1 according to Example 1. [Figure 2] Schematic configuration diagram for explaining the extrusion machine L1 applicable to Example 1. [Figure 3] Schematic configuration diagram (viewed from the extrusion direction side) for explaining the die 2A applicable to Example 1. [Figure 4] Schematic configuration diagram for explaining the extrusion machine L2 applicable to Example 1. [Figure 5] Schematic configuration diagram (radial cross-sectional view) for explaining the extruded body A2 according to Example 1. [Figure 6] Schematic configuration diagram (radial cross-sectional view) for explaining the extruded body B1 according to Example 2. [Figure 7] Schematic configuration diagram (viewed from the extrusion direction side) for explaining the die 2B applicable to Example 2. [Figure 8] Schematic configuration diagram for explaining the extrusion machine L3 applicable to Example 2. [Figure 9] Schematic configuration diagram (radial cross-sectional view) for explaining the extruded body B2 according to Example 2. [Figure 10] View of the sample P1 observed by a microscope (surface state). [Figure 11]The image shows the sample P2 observed under a microscope ((A) shows the surface condition, (B) shows the cross-sectional condition of the surface side, and (C) shows the cross-sectional condition of the interior side). [Figure 12] The image shows the sample P3 observed under a microscope ((A) shows the surface condition, (B) shows the cross-sectional condition of the surface side, and (C) shows the cross-sectional condition of the interior side). [Figure 13] This figure shows the sample P4 observed under a microscope ((A) shows the surface condition, and (B) shows the cross-sectional condition of the interior). [Modes for carrying out the invention]

[0025] The method for manufacturing an extruded article according to the embodiments of the present invention is completely different from, for example, the method of simply heat-treating the surface of a TPE foamed article at the same time as extrusion molding, as described in Patent Document 1 (hereinafter referred to as simply the surface heat treatment method).

[0026] In other words, this embodiment is a method comprising a molding step of extruding a foaming TPE composition and a non-foaming thermoplastic elastomer composition that does not contain a foaming agent (hereinafter appropriately referred to simply as a non-foaming TPE composition), thereby foaming the foaming agent through the extrusion molding. This method forms an extruded molded body comprising: a mounting base made of the foaming TPE composition or the non-foaming TPE composition that can be attached to any position on the body of an automobile (hereinafter appropriately referred to simply as an arbitrary position); an elastic part made of the foaming TPE composition that can elastically contact a proximity position in the automobile that is close to the aforementioned arbitrary position (for example, a position in the automobile that is opposite to the arbitrary position; hereinafter appropriately referred to simply as a proximity position); and a coating layer made of the non-foaming TPE composition that covers the surface of the elastic part (for example, the outer and inner surfaces in the case of an elastic part having a hollow portion). Furthermore, the foamed TPE composition and the non-foamed TPE composition are each composed of both a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component is within the range of 70 / 30 to 60 / 40.

[0027] According to this embodiment of the extruded molded article, even if the structure has a sponge-like elastic part with a low specific gravity achieved by using a foamed TPE composition, it is possible to suppress the rigidity from becoming too high, and recycling can be facilitated. Furthermore, since the surface of the elastic part can be covered with a coating layer, even if the elastic part is formed in a sponge-like state by a foaming agent, the surface roughness of the elastic part can be suppressed, making it easier to obtain desired properties and appearance. Moreover, since the coating layer made of non-foamed TPE is not only applied to the elastic contact side, which is the close-proximity side of the outer circumferential surface of the elastic part, but also to the non-elastic side, which is the opposite side of the close-proximity side of the elastic part, it becomes easier to improve the mechanical properties of the elastic part. Therefore, it is possible to contribute to lower specific gravity, resource conservation, etc., and to easily obtain desired surface smoothness and mechanical properties.

[0028] The manufacturing method for the extruded article of this embodiment is an extrusion molding method using both a foamed TPE composition and a non-foamed TPE composition, as described above, wherein the rubber component / thermoplastic resin component ratio in both is within the range of 70 / 30 to 60 / 40, and the coating layer made of the non-foamed TPE composition can be applied to the surface (outer and inner circumferential surfaces) of the elastic part made of the foamed TPE composition, allowing for a variety of design modifications.

[0029] In other words, it is possible to appropriately apply common technical knowledge from various fields (e.g., extrusion molding, weatherstrips, thermoplastic elastomers, blowing agents, etc.) and modify the design as needed by referring to prior art documents, etc. Examples 1 and 2 shown below are examples of this. In Examples 1 and 2 described below, detailed explanations are omitted as appropriate, for example, by referring to the same reference numerals and terms for similar content.

[0030] ≪Example 1≫ <An example of an extruded article according to Example 1> Figure 1 illustrates the structure of the extruded body A1 according to this embodiment 1, and shows an example of a hood seal interposed and applied between the cowl top and bonnet hood of an automobile (not shown in the figure).

[0031] The extruded body A1 is obtained by extruding both a foamed TPE composition and a non-foamed TPE composition (for example, by extruding using the extruders L1 and L2 described later), and mainly comprises a sponge-like mounting base 11 and an elastic part 12 formed by foaming through the extrusion of the foamed TPE composition, and an outer peripheral coating layer 13 and an inner peripheral coating layer 14 formed by extrusion of the non-foamed TPE composition.

[0032] The mounting base 11 is formed in a long, thin plate shape in the extrusion direction of extrusion molding (hereinafter simply referred to as the extrusion direction as appropriate), and one end face in the thickness direction of the mounting base 11 (the lower side shown in Figure 1) is configured to be attachable to any position on the cowl top. The mounting structure of the mounting base 11 to the cowl top is not particularly limited, but as an example, it can be attached to the cowl top by fitting or bonding, or by using a clip such as the one in Patent Document 1 (a clip indicated by reference numeral 4 in Patent Document 1).

[0033] The elastic portion 12 is integrally provided on the other end face side (upper side in Figure 1) in the thickness direction of the mounting base portion 11, and has a substantially arc-shaped radial cross-section, thereby having a long hollow portion 15c in the extrusion direction, allowing it to be elastically deformable. The outer peripheral surface coating layer 13 is provided covering the outer peripheral surface 15a of the elastic portion 12, and is configured to be elastically contactable with, for example, a closed bonnet hood (i.e., a close-proximity position). The inner peripheral surface coating layer 14 is provided covering the inner peripheral surface 15b of the elastic portion 12.

[0034] The dimensions t1, t2, etc., in the thickness direction of the outer circumferential coating layer 13 and the inner circumferential coating layer 14 can be appropriately set according to the desired shape of the extruded product A1 and the desired mechanical properties, and are not particularly limited. As an example, the dimensions t1, t2 in the thickness direction can be set within the range of 50 μm to 500 μm.

[0035] <Examples of foaming TPE compositions and non-foaming TPE compositions> Each foamed TPE composition and non-foamed TPE composition is composed of both a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component should be within the range of 70 / 30 to 60 / 40 (hereinafter appropriately referred to as the example component range). Various additives (e.g., inorganic fillers, oils, etc.) may be added depending on the shape of the target extruded article A1 and the desired mechanical properties.

[0036] According to the extruded article A1 obtained by setting the rubber component / thermoplastic resin component within the example component range, the crosslinked rubber particles of the rubber component are easily dispersed as domains (island phases) in the matrix (sea phase) of the thermoplastic resin component, making it possible to obtain a desired sea-island structure. In the case of the mounting base 11 and elastic part 12 made of a foaming TPE composition, the foaming agent foams in the matrix (sea phase) of the thermoplastic resin component.

[0037] If the rubber component / thermoplastic resin component falls outside the range of the example components, for example, if the blending ratio of the rubber component is set too high, it may be possible to suppress the rigidity (hardness) of the extruded molded product A1 and improve its durability, but the area of ​​the matrix made of thermoplastic resin component will decrease. In this case, in the foamed TPE composition, the foaming agent is likely to foam insufficiently, and there is a risk that the extruded molded product will not be extruded as desired.

[0038] Furthermore, in foamed TPE compositions and non-foamed TPE compositions, it is sufficient that there is at least a difference in the presence or absence of a foaming agent, and common components other than the foaming agent (e.g., TPE and additives) may be applied. Examples of TPE include TPO, TPS, TPV, etc.

[0039] <Example of a foaming agent> Examples of foaming agents incorporated into a foamable TPE composition include microcapsules that can be foamed during the extrusion molding of the foamable TPE composition, organic foaming agents, supercritical fluid foaming agents, etc. These can be appropriately selected and applied within a range that does not excessively impair the appearance or mechanical properties of the target extruded product A1.

[0040] For example, when extruding a foamed TPE composition, a foaming agent can be selected that can foam as desired (for example, foam at an extrusion temperature of 195-220°C), and the foaming agent can be blended into the foamed TPE composition in an amount of several WT% (specifically, 1-5 WT%), and the foaming agent can be applied so that the cell diameter of the foamed cells formed in the extruded body A1 by the foaming of the foaming agent (in the case of Figure 1, the foamed cells formed in the mounting base 11 and elastic part 12) is in the range of several tens to several hundred micrometers (specifically, 50 μm to 100 μm). With the extruded body A1 obtained by applying the foaming agent in this way, it is possible to reduce the specific gravity (for example, to a specific gravity in the range of 0.4-0.8) compared to when the foaming agent is not applied.

[0041] <An example of an extrusion molding machine applicable to Example 1> Figure 2 illustrates the configuration of an extrusion machine L1 applicable to the manufacturing method of an extruded body A1. The extrusion machine L1 mainly comprises an extruder 31 that extrudes and molds a foamy TPE composition through a die 2A, an extruder 32 that extrudes and molds a non-foamy TPE composition through the die 2A, a take-up machine 41 that pulls and takes up the extruded body A1 extruded and molded from the die 2A in the extrusion direction, and a cooling tank 42 that cools the extruded body A1 while it is being pulled by the take-up machine 41 (cooling between the die 2A and the take-up machine 41).

[0042] The die 2A can be adapted to various configurations. For example, when forming an extruded body A1 as shown in Figure 1, it can be adapted to the configuration shown in Figure 3. The die 2A shown in Figure 3 is provided with a foaming discharge port 22 for discharging a foaming TPE composition in the extrusion direction to form the mounting base 11 and the elastic portion 12, and non-foaming discharge ports 23 and 24 for discharging a non-foaming TPE composition in the extrusion direction to form the outer peripheral coating layer 13 and the inner peripheral coating layer 14, respectively.

[0043] With the extrusion molding machine L1 described above, it is possible to co-extrude a foamed TPE composition and a non-foamed TPE composition to form an extruded product A1 as shown in Figure 1.

[0044] Immediately after being extruded from the die 2A (before being cooled in the cooling tank 42), the shape of the extruded body A1 tends to expand radially due to the so-called die swell phenomenon. However, until it is cooled in the cooling tank 42, it tends to shrink radially because it is stretched in the extrusion direction by the tensile force of the take-up machine 41. For example, if the tensile force of the take-up machine 41 becomes too large, the extruded body A1 may shrink too much radially, and there is a risk that the outer circumferential coating layer 13 and the inner circumferential coating layer 14 may not have sufficient thickness.

[0045] In such cases, instead of simply suppressing the tensile force of the take-up machine 41, the shape of the nozzle 2A can be appropriately set. For example, in order to easily secure the desired thickness in the outer surface coating layer 13 and the inner surface coating layer 14, the dimensions t corresponding to the layer thickness direction of the outer surface coating layer 13 and the inner surface coating layer 14 can be set in the non-foaming discharge ports 23 and 24, respectively. A1 ,t A2 One possible setting is to set it so that it is within the range of 1.2 to 2 times the dimensions t1 and t2 in the thickness direction of the outer peripheral coating layer 13 and inner peripheral coating layer 14 after cooling by the cooling tank 42.

[0046] <Other examples of extrusion molding machines applicable to Example 1> The method for forming the outer surface coating layer 13 is not limited to a method of extruding a foamed TPE composition using an extruder 32, such as the extruder L1. For example, it may also be a method of laminating a long, strip-shaped film 13a made of a non-foamed TPE composition onto the outer surface 15a of the elastic part 12 using an extruder L2, as shown in Figure 4 below. Such a method of laminating a film 13a onto the outer surface 15a of the elastic part 12 can be easily realized by appropriately applying well-known techniques (for example, Japanese Patent No. 6082091; hereinafter simply referred to as "references" as appropriate).

[0047] The extrusion molding machine L2 shown in Figure 4 is equipped with the same die 2A, extruder 31, extruder 32, take-up machine 41, and cooling tank 42 as the extrusion molding machine L1, but also includes a film delivery roller 43. One end of a film 13a made of a non-foaming TPE composition is pre-wound onto this film delivery roller 43, and the other end of the film 13a can be fed towards the die 2a.

[0048] In the die 2A of the extrusion molding machine L2, the other end of the film 13a supplied from the film delivery roller 43 is appropriately designed (for example, as shown by the die indicated by reference numeral 27 in Figures 1 to 4 of the reference) so that it can be discharged from, for example, the non-foaming discharge port 23 and laminated onto the outer surface 15a of the elastic part 12.

[0049] <Other> In Figure 1, both the mounting base 11 and the elastic part 12 of the extruded body A2 are depicted as being made of the same foamed TPE composition, but this is not limited to this, and the two parts may be made of different materials. As a specific example, as shown in Figure 5, the extruded body A2 has a mounting base 11A formed by extrusion molding of a non-foamed TPE composition and an elastic part 12 formed of a foamed TPE composition. With such an extruded body A2, the rigidity of the mounting base 11A can be increased, while at least the specific gravity of the elastic part 12 can be reduced, resulting in a lighter weight.

[0050] When forming this extruded body A2 using extrusion machines L1 and L2, the nozzle 2A may be configured to allow co-extrusion of the non-foaming TPE composition for the mounting base 11A and the foaming TPE composition for the elastic part 12 by appropriately modifying the design of the foaming discharge port 22 (detailed explanation omitted).

[0051] Example 2 <An example of an extruded article according to Example 2> Figure 6 illustrates the configuration of the extruded body B1 according to this embodiment 2, and shows an example of a door seal component (parting seal, etc.) that is interposed and applied between the body side panel and door panel of an automobile (not shown in the figure).

[0052] Extruded body B1, like extruded bodies A1 and A2, is obtained by extrusion molding (for example, by extrusion molding machines L1 and L2, or extrusion molding machine L3 described later) using both a foamed TPE composition and a non-foamed TPE composition, and mainly comprises a sponge-like mounting base 51 and elastic parts 52 and 53 formed by foaming through extrusion molding of the foamed TPE composition, and elastic contact side coating layers 54a and 55a and non-elastic contact side coating layers 54b and 55b formed by extrusion molding of the non-foamed TPE composition.

[0053] The mounting base 51 is formed in a long, thin plate shape in the extrusion direction, and is configured so that one end face in the thickness direction of the mounting base 51 (the lower side shown in Figure 6) can be attached to any position on the door panel (for example, the lower side of the door inner panel). The mounting structure of the mounting base 51 to the door panel is not particularly limited, but examples include attaching it to the door panel by fitting or adhesive, or attaching it using a clip as described in Patent Document 1.

[0054] The elastic parts 52 and 53 are integrally provided at one end side and the other end side in the width direction of the mounting base part 51 (the left side and the right side in FIG. 6), and the cross-sectional shape in the width direction forms a lip shape that is warped and inclined in a direction protruding from the one end side and the other end side and separating from the body side panel side, and thus is configured to be elastically deformable.

[0055] The elastic contact side covering layers 54a and 55a are respectively provided to cover the elastic contact side surfaces 52a and 53a on the body side panel side (that is, the proximity position side) of the outer peripheral surfaces of the elastic parts 52 and 53, and are configured to be elastically contactable with the body side panel.

[0056] The non-elastic contact side covering layers 54b and 55b are respectively provided to cover the non-elastic contact side surfaces 52b and 53b which are on the opposite sides of the elastic contact side surfaces 52a and 53a of the outer peripheral surfaces of the elastic parts 52 and 53.

[0057] The dimensions t in the layer thickness direction of each of the elastic contact side covering layers 54a and 55a 3a ,t 4a etc. and the dimensions t in the layer thickness direction of each of the non-elastic contact side covering layers 54b and 55b 3b ,t 4b etc. can be appropriately set according to the shape of the target extruded molded body B1 and the desired mechanical properties, etc., similar to the outer peripheral surface covering layer 13 and the inner peripheral surface covering layer 14 of Example 1. As an example, the dimensions t 3a ,t 4a ,t 3b ,t 4b can be set within the range of 50 μm to 500 μm.

[0058] Furthermore, although Figure 6 depicts the contact-side coating layer 54a and the non-contact-side coating layer 54b as being integrated at the tip 52c side of the elastic portion 52, the design is not limited to this. For example, the two can be separated along the outer circumferential surface of the elastic portion 52 to form separate components (for example, a configuration in which a gap 52d is provided between them, as shown in Figure 9 below). The same applies to the contact-side coating layer 55a and the non-contact-side coating layer 55b as to the contact-side coating layer 54a and the non-contact-side coating layer 54b, and a detailed explanation of these is omitted.

[0059] <An example of an extrusion molding machine applicable to Example 2> Extruded body B1 can be extruded using extruders L1 and L2, similar to extruded bodies A1 and A2. In this case, the die 2A may be modified as appropriate, for example, a die 2B as shown in Figure 7 may be applied.

[0060] The nozzle 2B shown in Figure 7 is provided with a foaming discharge port 62 for dispensing a foaming TPE composition in the extrusion direction to form the mounting base 51 and elastic parts 52, 53; a non-foaming discharge port 63 for dispensing a non-foaming TPE composition in the extrusion direction to form the elastic side coating layer 54a and the non-elastic side coating layer 54b; and a non-foaming discharge port 64 for dispensing a non-foaming TPE composition in the extrusion direction to form the elastic side coating layer 55a and the non-elastic side coating layer 55b.

[0061] The non-foaming discharge port 63, like the non-foaming discharge ports 23 and 24, has dimensions t corresponding to the thickness direction of the elastic contact side coating layer 54a and the non-elastic contact side coating layer 54b. B3a ,t B3b The dimension t in the thickness direction of the elastic contact side coating layer 54a and the non-elastic contact side coating layer 54b after cooling by the cooling tank 42 3a ,t 3b One example is setting it within a range of 1.2 to 2 times. The same applies to the non-foaming discharge port 64, where the dimension t corresponds to the thickness direction of the elastic contact side coating layer 55a and the non-elastic contact side coating layer 55b. B4a ,t B4bThe dimension t in the thickness direction of the elastic contact side coating layer 54a and the non-elastic contact side coating layer 54b after cooling by the cooling tank 42 4a ,t 4b One possible setting is within the range of 1.2 to 2 times the original value.

[0062] Furthermore, when the nozzle 2B is applied to the extrusion molding machine L2, the non-foaming discharge ports 63 and 64 can be appropriately designed (for example, as shown by the nozzle indicated by reference numeral 27 in Figures 1 to 4 of the reference) to discharge the other end of the film 13a made of a non-foaming TPE composition and laminate it onto the outer circumferential surfaces of the elastic parts 52 and 53 (in the case of the elastic part 52, the elastic side surface 52a or the non-elastic side surface 52b), similar to Example 1.

[0063] Furthermore, in the case where all layers of the extruded body B1, including the elastic side coating layers 54a, 55a and the non-elastic side coating layers 54b, 55b, are formed from film 13a, it is also possible to apply an extruder L3 as shown in Figure 8. The extruder L3 in Figure 8 is a simplified configuration of the extruder L2, with the die 2B replaced by the die 2A, and the extruder 32 removed.

[0064] With the extrusion molding machines L1, L2, and L3 to which the die 2B described above is applied, it is possible to co-extrude a foamed TPE composition and a non-foamed TPE composition (or apply film 13a and extrude them), making it possible to obtain an extruded body B1 as shown in Figure 6.

[0065] <Other> In Figure 6, the mounting base 51 and elastic parts 52, 53 of the extruded body B1 are depicted as being made of the same foamed TPE composition, but this is not limited to this, and the two parts may be made of different materials. As a specific example, as shown in Figure 9, the extruded body B2 has a mounting base 51A formed by extrusion molding of a non-foamed TPE composition and elastic parts 52, 53 formed from a foamed TPE composition.

[0066] When forming this extruded body B2 using extrusion machines L1, L2, and L3, the nozzle 2B may be configured to allow co-extrusion of the non-foaming TPE composition for the mounting base 51A and the foaming TPE composition for the elastic parts 52 and 53 by appropriately redesigning the foaming nozzle 62 (detailed explanation omitted).

[0067] <Verification> <Verification of extruded articles using surface heat treatment methods> First, TPE was extruded using the surface heat treatment method shown in Patent Document 1 (the method shown in paragraph

[0024] of Patent Document 1, Figure 1, etc.) to create hood seal samples P1 to P3. As a reference example for samples P1 to P3, a hood seal applied between the cowl top and bonnet hood of a commercially available automobile (Daihatsu Move) was used as sample P4.

[0068] Furthermore, specific gravity (JIS K7112), tensile strength (JIS K6251), elongation permanent strain (JIS K6262), and surface roughness (Ra) were observed for samples P1 to P4, and the results shown in Table 1 below were obtained. In addition, the surface and cross-sectional conditions of samples P1 to P4 were observed with a microscope (magnification 300x), and the results shown in Figures 10 to 13 were obtained.

[0069] For samples P1 to P3, the amount of water (foaming water acting as a foaming agent) injected into the cylinder of the extruder during TPE extrusion molding was set to a range of 0 to 2 phr. Furthermore, the heat treatment of each surface of samples P1 to P3 (the surface of the TPE foamed molded body) was performed by setting the extruder die to a range of 200°C to 220°C.

[0070] Furthermore, for the observation of surface roughness, samples P1 to P4 were first punched out into rectangular flat plates (5 mm × 100 mm × 2 mm) to prepare sample pieces. After wiping off any dirt from the surface of the sample pieces with alcohol, the surface roughness (ten-point average roughness) of each sample piece was measured using a ten-point average method (method compliant with JIS-B0601) with a surface roughness meter (SurfCorder SE30D manufactured by Kosaka Laboratory Co., Ltd.). The stylus used for the surface roughness meter had a tip radius of 2 μm.

[0071] [Table 1]

[0072] As shown in Table 1, in samples P1 to P3, while the specific gravity can be reduced by adding foaming water, the tensile strength decreases and the elongation permanent strain increases. Furthermore, in samples P1 to P3, depending on the amount of foaming water added, foam cells like those shown in Figures 11 and 12 are formed, which increases the surface roughness.

[0073] Furthermore, when the surfaces of samples P1 to P3 were heat-treated at 300°C using an external heater installed near the die of the extrusion molding machine, the surfaces melted and a tendency for surface roughness to improve was observed. However, phenomena such as variations in surface roughness and uneven gloss occurred. It was also found that these phenomena became more pronounced as the shape of samples P1 to P3 became more complex.

[0074] Therefore, it was found that in samples P1 to P3 prepared by the surface heat treatment method, even if the specific gravity was reduced and weight was achieved, the tensile strength and aging resistance were low, and the surface smoothness was also low.

[0075] <Verification of extruded articles using Examples 1 and 2> First, using the method shown in Example 1, samples S1 to S3 of the extruded body A1 shown in Figure 1 were prepared by extrusion molding (extrusion molding temperature 195°C to 220°C) using both the foamed TPE composition and the non-foamed TPE composition. Furthermore, as reference examples of cases where the outer peripheral coating layer 13 and inner peripheral coating layer 14 are not formed in samples S1 to S3, a sponge-like molded body sample S4 was prepared by extruding a molded body using only the foamed TPE composition to have the same shape as extruded body A1, and a solid molded body sample S5 was prepared by extruding a molded body using only the non-foamed TPE composition to have the same shape as extruded body A1.

[0076] Then, using the same observation conditions as for samples P1 to P4, specific gravity, tensile strength, compression set (JIS K6262), surface roughness (Ra), and color difference (ΔE) were observed for samples S1 to S5, and the results shown in Table 2 below were obtained.

[0077] Furthermore, for the foamed TPE composition and non-foamed TPE composition of samples S1 to S5, each was made using TPV (EL1306B manufactured by JSR Corporation), and the rubber component / thermoplastic resin component was within the range of the example components. In addition, for the foamed TPE composition, a 3 wt% microcapsule was added as a foaming agent.

[0078] In observing the color difference, in accordance with JIS Z 8722-C, samples S1 to S5 were heat-treated at 70°C for 70 hours, then left at room temperature for 30 minutes. The hue difference (ΔE) between samples S1 to S5 after the leave and samples S1 to S5 before the heat treatment (immediately after extrusion molding) was measured using a spectrophotometer (Konica Minolta cμ-2600d) to investigate the resistance to discoloration, assuming a whitening phenomenon.

[0079] [Table 2]

[0080] As shown in Table 2, samples S1 to S3 exhibited a lower specific gravity, similar to the sponge-like sample S4. Furthermore, compared to sample S4, they showed increased tensile strength in proportion to the thickness of the outer and inner surface coating layers, and also demonstrated reduced surface roughness and color difference. Additionally, samples S1 to S3 showed suppressed compression set, similar to the solid sample S5.

[0081] Therefore, it was found that in samples S1 to S3, not only was it possible to reduce the specific gravity and thus the weight, but good tensile strength and durability could also be obtained, and the surface smoothness was also good, making it easier to obtain desired properties (such as sealing ability) and appearance.

[0082] Furthermore, in the method shown in Example 2, both foamed TPE composition and non-foamed TPE composition were used for extrusion molding (extrusion molding temperature 195°C to 220°C) to prepare a sample of the extruded body B1 shown in Figure 6. When the specific gravity, tensile strength, compression set, surface roughness, and color difference were observed under the same observation conditions as for samples S1 to S3, it was confirmed that the same results as in Table 2 were obtained.

[0083] Although the present invention has been described in detail only with respect to the specific examples described above, it will be obvious to those skilled in the art that a wide variety of modifications are possible within the scope of the technical concept of the present invention, and it is natural that such modifications fall within the scope of the claims. [Explanation of Symbols]

[0084] A1, A2, B1, B2... Extruded products L1~L3...Extrusion molding machine 11,51…Mounting base 12, 52, 53… Elastic part 13,14,54a,55a,54b,55b...covering layer 2A, 2B… nozzles

Claims

1. At a minimum, a foaming thermoplastic elastomer composition containing a foaming agent and a non-foaming thermoplastic elastomer composition not containing the foaming agent are used in an extrusion molding process, and the foaming agent is foamed by the extrusion molding process. A mounting base comprising the foamable thermoplastic elastomer composition or the non-foamable thermoplastic elastomer composition, having an elongated shape in the extrusion direction of the extrusion molding, and being attachable to any position on the body of an automobile, The foamed thermoplastic elastomer composition comprises an elastic portion having a long hollow portion in the extrusion direction, which is elastically contactable with a proximity position close to the arbitrary position in the automobile, The non-foaming thermoplastic elastomer composition comprises an outer peripheral coating layer coated on the outer peripheral surface of the elastic portion, The inner circumferential surface coating layer is made of the non-foaming thermoplastic elastomer composition and is applied to the inner circumferential surface of the elastic part, An extruded molded body is formed, The foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition each consist of a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component is in the range of 70 / 30 to 60 / 40. The elastic portion and the inner circumferential coating layer are formed by co-extruding the foamed thermoplastic elastomer composition and the non-foamed thermoplastic elastomer composition in the molding process. The method for manufacturing an extruded article is characterized in that the outer peripheral coating layer is formed by laminating a long, strip-shaped film made of the non-foaming thermoplastic elastomer composition onto the outer peripheral surface of the elastic portion.

2. At a minimum, a foaming thermoplastic elastomer composition containing a foaming agent and a non-foaming thermoplastic elastomer composition not containing the foaming agent are used in an extrusion molding process, and the foaming agent is foamed by the extrusion molding process. A mounting base comprising the foamable thermoplastic elastomer composition or the non-foamable thermoplastic elastomer composition, having an elongated shape in the extrusion direction of the extrusion molding, and being attachable to any position on the body of an automobile, The foamed thermoplastic elastomer composition comprises an elastic portion having a long hollow portion in the extrusion direction, which is elastically contactable with a proximity position close to the arbitrary position in the automobile, The non-foaming thermoplastic elastomer composition comprises an outer peripheral coating layer coated on the outer peripheral surface of the elastic portion, The inner circumferential surface coating layer is made of the non-foaming thermoplastic elastomer composition and is applied to the inner circumferential surface of the elastic part, An extruded molded body is formed, The foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition each consist of a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component is in the range of 70 / 30 to 60 / 40. The molding process described above is: A dispensing step in which the foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition are extruded through a die and then extruded, A cooling step is performed in which the extruded body, which has been extruded from the die by the discharge step, is cooled while being pulled and moved in the extrusion direction by a take-up machine, It has, The aforementioned nozzle is, A foaming discharge port for discharging the foaming thermoplastic elastomer composition in the extrusion direction, A non-foaming discharge port for the outer surface coating layer, which discharges the non-foaming thermoplastic elastomer composition for forming the outer surface coating layer in the extrusion direction, A non-foaming discharge port for the inner circumferential coating layer, which discharges the non-foaming thermoplastic elastomer composition for forming the inner circumferential coating layer in the extrusion direction, It has, In the non-foaming discharge port for the outer peripheral coating layer, the dimension corresponding to the thickness direction of the outer peripheral coating layer is set within a range of 1.2 to 2 times the dimension in the thickness direction of the outer peripheral coating layer after cooling. A method for manufacturing an extruded article, characterized in that the dimension of the inner circumferential coating layer corresponding to the thickness direction of the inner circumferential coating layer in the non-foaming discharge port for the inner circumferential coating layer is set within a range of 1.2 to 2 times the dimension in the thickness direction of the inner circumferential coating layer after cooling.

3. At a minimum, a foaming thermoplastic elastomer composition containing a foaming agent and a non-foaming thermoplastic elastomer composition not containing the foaming agent are used in an extrusion molding process, and the foaming agent is foamed by the extrusion molding process. A mounting base made of the foaming thermoplastic elastomer composition or the non-foaming thermoplastic elastomer composition, having an elongated shape in the extrusion direction of the extrusion molding, which can be attached to any position on the body of an automobile, The elastic portion comprises the foamed thermoplastic elastomer composition, is elongated in the extrusion direction and protrudes from the mounting base, and is lip-shaped, and is elastically contactable with a proximity position close to the arbitrary position in the automobile, The non-foaming thermoplastic elastomer composition comprises an elastic contact side coating layer that is applied to the elastic contact side which is the proximity side of the elastic portion, A non-elastic side coating layer comprising the non-foaming thermoplastic elastomer composition, which is coated on the non-elastic side surface of the elastic portion that is opposite to the proximity side, An extruded molded body is formed, The foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition each consist of a rubber component and a thermoplastic resin component, and the weight ratio of the rubber component / thermoplastic resin component is in the range of 70 / 30 to 60 / 40. The molding process described above is: A dispensing step in which the foaming thermoplastic elastomer composition and the non-foaming thermoplastic elastomer composition are extruded through a die and then extruded, A cooling step is performed in which the extruded body, which has been extruded from the die by the discharge step, is cooled while being pulled and moved in the extrusion direction by a take-up machine, It has, The aforementioned nozzle is, A foaming discharge port for discharging the foaming thermoplastic elastomer composition in the extrusion direction, A non-foaming discharge port for the elastic contact side coating layer, which discharges the non-foaming thermoplastic elastomer composition for forming the elastic contact side coating layer in the extrusion direction, A non-foaming discharge port for a non-elastic side coating layer, which discharges the non-foaming thermoplastic elastomer composition for forming the non-elastic side coating layer in the extrusion direction, It has, In the non-foaming discharge port for the elastic contact side coating layer, the dimension corresponding to the thickness direction of the elastic contact side coating layer is set within a range of 1.2 to 2 times the dimension in the thickness direction of the elastic contact side coating layer after cooling. A method for manufacturing an extruded article, characterized in that the dimension of the non-foaming discharge port for the non-elastic side coating layer, corresponding to the thickness direction of the non-elastic side coating layer, is set within a range of 1.2 to 2 times the dimension in the thickness direction of the non-elastic side coating layer after cooling.

4. The method for manufacturing an extruded article according to claim 1 or 2, characterized in that the dimensions in the thickness direction of the outer peripheral coating layer and the inner peripheral coating layer are each within the range of 50 μm to 500 μm.

5. The method for manufacturing an extruded article according to claim 3, characterized in that the dimensions in the thickness direction of the elastic contact side coating layer and the non-elastic contact side coating layer are each within the range of 50 μm to 500 μm.

6. A method for manufacturing an extruded article according to any one of claims 1 to 3, characterized in that the cell diameter of the foam cells formed in the extruded article by the foaming of the foaming agent is in the range of 50 μm to 100 μm.

7. The method for manufacturing an extruded article according to any one of claims 1 to 3, characterized in that the elastic portion has a specific gravity in the range of 0.4 to 0.

8.

8. The method for producing an extruded article according to any one of claims 1 to 3, characterized in that the thermoplastic elastomer composition is composed of one of TPO, TPS, or TPV.

9. A method for manufacturing an extruded article according to any one of claims 1 to 3, characterized in that the extrusion molding temperature for the extrusion molding is in the range of 195°C to 220°C.

10. The method for producing an extruded article according to any one of claims 1 to 3, characterized in that the blowing agent is one of microcapsules, an organic blowing agent, or a supercritical fluid blowing agent.

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