JP2023037962A - Laminate, airless tire and method for producing laminate - Google Patents

Abstract

To provide a laminate that can improve bondability between a metal body and a resin body.SOLUTION: The present invention provides a laminate 1 having a metal body 2 and a resin body 3 joined together, an airless tire including the laminate 1, and a method for producing a laminate. The metal body 2 has asperities on a first face 4 joined to the resin body 3. The asperities have an arithmetic average roughness Ra of 50-150 μm.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present disclosure relates to laminates, airless tires, and methods of manufacturing laminates.

2. Description of the Related Art Conventionally, laminates in which a metal body and a resin body are bonded together have been used for various purposes. In recent years, such laminates have been used in the development of airless tires.

Patent Literature 1 below describes an airless tire. This heiress tire comprises a cylindrical tread ring having a ground contact surface, a hub arranged radially inside the tread ring and fixed to an axle, and spokes connecting the tread ring and the hub.

The hub is made of metal. On the other hand, the spokes are made of resin. Thus, the hub-spoke laminate corresponds to the laminate described above.

JP 2017-185925 A

In recent years, from the viewpoint of improving the durability of an airless tire, further improvement in bondability between a metal body and a resin body has been desired.

The present disclosure has been devised in view of the actual situation as described above, and a main object thereof is to provide a laminate capable of improving the bondability between a metal body and a resin body.

The present disclosure is a laminate in which a metal body and a resin body are bonded, wherein the metal body has an uneven portion on a first surface bonded to the resin body, and an arithmetic mean roughness of the uneven portion is provided. The thickness Ra of the laminate is 50-150 μm.

By adopting the above configuration, the joined body of the present disclosure can improve the joinability between the metal body and the resin body.

FIG. 2 is a partial cross-sectional view of the laminate of this embodiment; FIG. 4 is a partially enlarged view of a metal body having an uneven portion; It is sectional drawing explaining the manufacturing method of the laminated body of this embodiment. It is a partial front view of the heiress tire of the present embodiment as seen from the axle direction. FIG. 11 is a partially enlarged view of a metal body having uneven portions formed thereon according to Example 5;

Hereinafter, embodiments of the present disclosure will be described based on the drawings. It should be understood that the drawings contain exaggerated representations and representations that differ from the dimensional ratios of the actual structures in order to aid in understanding the content of the disclosure. In addition, throughout each embodiment, the same or common elements are denoted by the same reference numerals, and overlapping descriptions are omitted. Furthermore, the specific configurations shown in the embodiments and drawings are for understanding the contents of the present disclosure, and the present disclosure is not limited to the illustrated specific configurations.

[Laminate (first embodiment)]
[Overall Structure of Laminate]
FIG. 1 shows a partial cross-sectional view of a laminate 1 of this embodiment. As shown in FIG. 1, in the laminate 1 of this embodiment, a metal body 2 and a resin body 3 are joined together. The laminate 1 of this embodiment has an uneven portion on the first surface 4 that is bonded to the resin body 3 .

[Uneven part]
FIG. 2 is a partially enlarged view of the metal body 2 on which the uneven portion 5 is formed. In FIG. 2, the resin body 3 is omitted. The concave-convex portion 5 of the present embodiment has concave portions 5a and convex portions 5b. The recessed portion 5a is recessed inwardly of the metal body 2 with respect to the average line 7 of the roughness curve 6 (contour of the uneven portion 5). The convex portion 5 b protrudes toward the resin body 3 with respect to the average line 7 .

The concave-convex portion 5 can be formed, for example, by a known base treatment such as laser processing or shot blasting. In the present embodiment, laser processing is employed that can form the concave-convex portion 5 having arbitrary roughness with high accuracy. A known laser processing machine is used for the laser processing.

The arithmetic mean roughness Ra of the uneven portion 5 of this embodiment is set to 50 to 150 μm. Arithmetic mean roughness Ra can be measured according to JIS B0601 (1994). In this embodiment, first, a predetermined measurement area (120 mm long x 250 mm wide) is set on the first surface 4 on which the uneven portion 5 is formed, and five measurements arbitrarily selected from the measurement area are performed. The arithmetic mean roughness Ra is measured in each range (measuring point). Then, the average value of these five arithmetic mean roughnesses Ra is specified as the arithmetic mean roughness Ra of the irregularities 5 formed on the first surface 4 . Each measurement range is set to 1000 to 1500 μm. For the measurement of the arithmetic mean roughness Ra, for example, a laser microscope (VK-X160) manufactured by Keyence Corporation is used.

In the laminate 1 of the present embodiment, the arithmetic mean roughness Ra of the uneven portion 5 is set to 50 μm or more, so that a large (largely recessed) concave portion 5a is formed on the first surface 4 of the metal body 2. . Such a concave portion 5a allows the resin body 3 (shown in FIG. 1) to bite (into) the metal body 2, thereby exhibiting an anchor effect. On the other hand, by setting the arithmetic mean roughness Ra of the concave-convex portion 5 to 150 μm or less, it is possible to prevent the concave portion 5a from becoming larger (deeper) than necessary. As a result, since the laminate 1 allows the resin body 3 to enter the deep part of the recess 5a, formation of a gap (not shown) between the recess 5a and the resin body 3 can be suppressed. Prevents a decrease in anchor effect. From such a point of view, the arithmetic mean roughness Ra is preferably 80 μm or more and preferably 120 μm or less.

Thus, in the laminate 1 of the present embodiment, the anchor effect is expressed by setting the arithmetic mean roughness Ra of the uneven portion 5 within the above range, and the metal body 2 and the resin body shown in FIG. 3 can be improved.

In order to further improve the bondability, the ten-point average roughness Rz of the uneven portion 5 (shown in FIG. 2) is desirably larger than the arithmetic average roughness Ra. The ten-point average roughness Rz can be measured according to JIS B0601 (1994). Further, the ten-point average roughness Rz is the average value of the ten-point average roughness Rz measured in the five measurement ranges, similarly to the arithmetic average roughness Ra described above. It is specified as the ten-point average roughness Rz of the portion 5 .

By setting the ten-point average roughness Rz of the uneven portion 5 to be larger than the arithmetic average roughness Ra, the uneven portion 5 has a large area with a small amplitude (elevation from the average line 7) and is greatly recessed. The recess 5a can be formed locally (partially). As a result, the resin body 3 (shown in FIG. 1) can be effectively prevented from coming off in the recessed portion 5a that is greatly recessed. Furthermore, in the present embodiment, in the manufacturing method described later, the liquid resin (resin for forming the resin body 3) is gradually bitten into the recessed portion 5a from the region where the amplitude of the uneven portion 5 is small toward the deep portion of the recessed portion 5a. be able to. As a result, the concave portion 5a can be reliably filled with the resin body 3, so that formation of a gap (not shown) between the concave portion 5a and the resin body 3 can be suppressed.

Thus, in the laminate 1 of the present embodiment, the arithmetic mean roughness Ra is set within the above range, and the ten-point mean roughness Rz is set larger than the arithmetic mean roughness Ra, so that the metal Bondability between the body 2 and the resin body 3 can be further improved.

In order to effectively exhibit such effects, the ten-point average roughness Rz is desirably set to 300 to 800 μm. By setting the ten-point average roughness Rz to 300 μm or more, it is possible to form the concave portion 5a with a large recess, thereby exhibiting an anchor effect. On the other hand, by setting the ten-point average roughness Rz to 800 μm or less, it is possible to prevent the concave portion 5a from becoming larger than necessary, and the resin body 3 (resin) shown in FIG. can be surely eaten. As a result, formation of a gap (not shown) between the concave portion 5a and the resin body 3 can be suppressed, and deterioration of the anchoring effect can be prevented. From such a viewpoint, the ten-point average roughness Rz is preferably 400 μm or more and preferably 700 μm or less.

In the laminate 1 of the present embodiment, the first surface 4 can be directly bonded to the resin body 3 without an adhesive layer (not shown) intervening due to the improvement in bondability as described above. Become. As a result, the laminate 1 of the present embodiment prevents the adhesive layer from peeling off due to, for example, thermal stress generated between the metal body 2 and the resin body 3 having different coefficients of linear expansion. can be done. Furthermore, the laminate 1 can also prevent peeling of the adhesive due to deterioration over time. Therefore, the laminate 1 can be improved in durability. Each part will be described in detail below.

[Metal object]
As shown in FIG. 1, the metal body 2 is not particularly limited as long as it can be joined to the resin body 3 . Iron-based metals, aluminum-based metals, magnesium-based metals, copper-based metals, titanium-based metals, and the like can be used for the metal body 2 of the present embodiment, for example.

Iron-based metals include, for example, iron, steel, and stainless steel. Examples of aluminum-based metals include aluminum and aluminum alloys. Magnesium-based metals include, for example, magnesium alloys. Copper-based metals include, for example, copper and copper alloys. Titanium-based metals include, for example, titanium and titanium alloys.

Among the above metals, an aluminum-based metal is adopted for the metal body 2 of the present embodiment. Such aluminum-based metals have properties of light weight and high workability as compared with other metals. As a result, the uneven portion 5 (shown in FIG. 2) is formed in the laminate 1 with high accuracy, and the bondability with the resin body 3 can be improved.

[Resin body]
The resin body 3 is not particularly limited as long as it can be bonded to the metal body 2 . The resin body 3 of this embodiment is made of a polymeric material. Although the polymeric material is not particularly limited, it is preferably a resin or elastomer that can be molded by an injection method or a casting method.

Examples of resins or elastomers include polyolefin, polyvinyl chloride, polystyrene, methacrylic resin, polycarbonate, polyamide, polyimide, polyacetal, fluororesin, urea resin, phenolic resin, polyester, polyurethane, epoxy resin, melamine resin, and silicone resin. etc.

In the present embodiment, thermoplastic resins are used among the above polymeric materials (resins or elastomers) from the viewpoint of moldability and workability and degree of freedom in material design. The thermoplastic resin is not particularly limited, but a thermoplastic polyester elastomer resin, a thermoplastic polyamide elastomer resin, or a thermoplastic polyurethane elastomer resin can be employed. Among these thermoplastic resins, a thermoplastic polyester elastomer resin or a thermoplastic polyamide elastomer resin can be preferably used from the viewpoint of improving durability.

[Melt index]
The melt index (g/10 minutes) of the thermoplastic resin can be appropriately set as long as the resin body 3 can be bitten into the concave portion 5a (shown in FIG. 2) during molding. The melt index of this embodiment is measured at 190° C. or 230° C. under a load of 2160 g according to ASTM D1238.

The melt index is a measure of the fluidity of a molten thermoplastic resin. The higher the melt index, the better the fluidity and workability. In this embodiment, for example, a thermoplastic resin having a melt index of 10 to 50 g/10 minutes is used.

When the melt index is 10 g/10 minutes or more, the fluidity of the thermoplastic resin (liquid resin) can be increased, so that the resin body 3 can be made to bite into the concave portion 5a (shown in FIG. 2). Become. On the other hand, when the melt index is 50 g/10 minutes or less, it is possible to prevent the fluidity of the thermoplastic resin from becoming higher than necessary, thereby preventing the decrease in tensile strength. Thereby, the moldability of the resin body 3 is maintained. From such a point of view, the melt index is preferably 20 g/10 minutes or more and preferably 40 g/10 minutes or less.

[Molding shrinkage]
The molding shrinkage rate of the thermoplastic resin can be appropriately set. The molding shrinkage of this embodiment is measured according to JIS K7152-4 (2005).

The molding shrinkage rate is how much the thermoplastic resin (liquid resin 3A) shrinks in the mold 11 (shown in FIG. 3C) for forming the laminate 1 when it solidifies. is shown. The smaller the mold shrinkage ratio, the smaller the shrinkage of the liquid resin 3A due to solidification, so that the resin 3A (resin body 3) can be prevented from slipping out of the concave portion 5a. In this embodiment, for example, a thermoplastic resin having a molding shrinkage rate (measured on a molded product (test piece) with a thickness of 2 mm) of 0.1% to 1.0% is used.

Since the molding shrinkage rate is 1.0% or less, a large shrinkage of the thermoplastic resin (liquid resin 3A (shown in FIG. 3C)) is suppressed, and it bites into the concave portion 5a (shown in FIG. 2). It is possible to prevent the resin body 3 (resin 3A) from slipping out of the recess 5a. On the other hand, by setting the molding shrinkage rate to 0.1% or more, the shrinkage of the thermoplastic resin is suppressed from becoming smaller than necessary, and it is possible to prevent the mold from becoming difficult to remove from the mold 11 . can. From such a viewpoint, the molding shrinkage rate is preferably 0.8% or less, and preferably 0.3% or more.

[Production method]
Next, a method for manufacturing the laminate 1 of the present embodiment (hereinafter sometimes simply referred to as "manufacturing method") will be described. 3(a) to 3(c) are cross-sectional views for explaining the method for manufacturing a laminate according to this embodiment.

[Form uneven part]
In the manufacturing method of the present embodiment, first, as shown in FIG. 3A, a step of forming uneven portions 5 (shown in FIG. 2) on the first surface 4 of the metal body 2 is performed. In this embodiment, the smooth first surface 4 before the irregularities 5 are formed is irradiated with the laser beam L from the laser processing machine 9 . In the present embodiment, the laser light L is applied so that the arithmetic mean roughness Ra and the ten-point mean roughness Rz of the uneven portion 5 are within the above ranges. As a result, the uneven portion 5 (shown in FIG. 2) is formed on the first surface 4 .

[Melting Resin]
Next, in the manufacturing method of the present embodiment, a step of melting the resin 3A (shown in FIG. 3C) for forming the resin body 3 is performed. In this embodiment, for example, a known injection molding machine (not shown) is used. In this embodiment, the temperature of the resin 3A is controlled (for example, 200 to 300° C.) in the cylinder (not shown) of the injection molding machine. Thereby, the resin 3A is melted into a liquid state.

[Liquid Resin Contacts First Surface]
Next, in the manufacturing method of the present embodiment, the step of bringing the liquid resin 3A into contact with the first surface 4 having the uneven portion 5 (shown in FIG. 2) is performed. In the process of the present embodiment, first, as shown in FIG. 3B, the metal body 2 having the uneven portion 5 formed thereon is set in the cavity 12 of the mold 11, for example. At this time, an empty space 13 is left in the cavity 12 so that the resin 3A (shown in FIG. 3(c)) can be supplied. Also, the first surface 4 (uneven portion 5 ) of the metal body 2 is positioned so as to face the empty space 13 of the cavity 12 .

Next, in this embodiment, as shown in FIG. 3C, a liquid resin 3A is supplied (injected) into the empty space 13 of the cavity 12 from a cylinder (not shown) of the injection molding machine. Thereby, in this embodiment, the liquid resin 3A can be brought into contact with the first surface 4 having the uneven portion 5 (shown in FIG. 2).

As shown in FIG. 2 , on the first surface 4 of the present embodiment, the amplitude of the uneven portion 5 (elevation from the average line 7) is widely formed in a small region, and the large recessed portion 5a is locally formed. (partially) formed. As a result, the liquid resin 3A can be made to gradually bite into the concave portion 5a from the region where the amplitude of the uneven portion 5 is small toward the deep portion of the concave portion 5a. be able to. Therefore, formation of a gap (not shown) between the concave portion 5a and the resin body 3 can be suppressed.

As in the present embodiment, when the resin 3A is a thermoplastic resin, in the step of bringing the liquid resin 3A into contact with the first surface 4, the thermoplastic resin (resin 3A) is liquid at 200 to 300° C. It is desirable to contact the first surface 4 . By setting the temperature to 200° C. or higher, the fluidity of the resin 3A can be increased, and the resin 3A can be made to bite (enter) the concave portion 5a (shown in FIG. 2). On the other hand, by setting the temperature to 300° C. or less, it is possible to prevent the resin 3A (resin body 3) from being thermally deteriorated (changed in physical properties). From such a point of view, the temperature of the thermoplastic resin (resin 3A) brought into contact with the first surface 4 is preferably 230° C. or higher and preferably 270° C. or lower.

In the present embodiment, since the melt index is set within the above range, the fluidity of the thermoplastic resin (liquid resin) is increased while the decrease in tensile strength is prevented. Thereby, in the present embodiment, the moldability of the resin body 3 is maintained while the resin body 3 is made to bite into the concave portion 5a (shown in FIG. 2).

[Joining metal body and resin body]
Next, in the manufacturing method of the present embodiment, a step of curing the resin 3A in contact with the first surface 4 and joining the metal body 2 and the resin body 3 is performed. In this embodiment, the resin 3A (thermoplastic resin) is cooled and hardened within the cavity 12 . As a result, the laminate 1 (shown in FIG. 1) in which the metal body 2 and the resin body 3 are joined (integrally molded) is obtained.

In the manufacturing method of the present embodiment, the uneven portion 5 (shown in FIG. 2) having the arithmetic average roughness Ra and the ten-point average roughness Rz within the above ranges is formed on the first surface 4 of the metal body 2. Therefore, it is possible to manufacture the laminate 1 capable of improving the bondability between the metal body 2 and the resin body 3 while exhibiting the anchor effect. Furthermore, in the present embodiment, the molding shrinkage rate is set within the above range. can be easily removed from the mold.

In this embodiment, the first surface 4 is directly bonded to the resin body 3 without interposing an adhesive layer (not shown). As a result, in the manufacturing method of the present embodiment, the process of applying the adhesive and the process of applying heat to the adhesive to cause it to react can be omitted, so the process and equipment can be simplified when manufacturing the laminate 1. It is possible to make

[Laminate (second embodiment)]
Although the resin body 3 is made of a thermoplastic resin in the above-described embodiments, it is not limited to such an aspect. The resin body 3 may be made of a thermosetting resin. In this embodiment, the same reference numerals are assigned to the same configurations as in the previous embodiments, and the description may be omitted.

A thermosetting resin is resistant to deformation even when heat is applied after molding, and has the property of being able to suppress temperature rise when a load is applied. Therefore, the resin body 3 made of thermosetting resin can improve heat resistance.

Although the thermosetting resin is not particularly limited, for example, a resin that can be molded by a casting method is preferable. Examples of resins include polyolefin, polyvinyl chloride, polystyrene, methacrylic resin, polycarbonate, polyamide, polyimide, polyacetal, fluororesin, urea resin, phenol resin, polyester, polyurethane, epoxy resin, melamine resin, silicone resin, and the like. mentioned.

The thermosetting resin is preferably a polyurethane resin, a polyamide resin, a polyester resin, or the like, and more preferably a polyurethane resin, from the viewpoint of moldability and workability and degree of freedom in material design. Such polyurethane resins can exhibit higher elastic properties than other resins.

In the laminate 1 of this embodiment, as in the previous embodiments, the uneven portion 5 (shown in FIG. 2) having the arithmetic mean roughness Ra set in the above range ) is provided. As a result, in the laminate 1 of this embodiment, the resin body 3 made of a thermosetting resin can be made to bite into the metal body 2, thereby exhibiting an anchor effect. Therefore, the laminate 1 of this embodiment can improve the bondability between the metal body 2 and the resin body 3 . In order to effectively exhibit such an effect, it is desirable that the ten-point average roughness Rz of the uneven portion 5 is set within the above range.

In the manufacturing method of this embodiment, the resin 3A (thermosetting resin) is heated in the step of joining the metal body 2 and the resin body 3 shown in FIG. 3(c). Thereby, the resin 3A in contact with the first surface 4 is cured, and the metal body 2 and the resin body 3 can be joined together.

[Laminate (third embodiment)]
In the embodiments so far, as shown in FIG. 1, the first surface 4 is directly bonded to the resin body 3 without interposing an adhesive layer (not shown). is not limited to For example, the first surface 4 may be bonded to the resin body 3 via an adhesive layer. In this embodiment, the same reference numerals are assigned to the same configurations as in the previous embodiments, and the description may be omitted.

The adhesive layer (not shown) of this embodiment can join (bond) the metal body 2 and the resin body 3 by its adhesive strength. Furthermore, the adhesive layer of the present embodiment is bitten into the concave portion 5 a of the metal body 2 together with the resin body 3 . Thereby, the layered product 1 of this embodiment can further improve the bondability between the metal body 2 and the resin body 3 .

The adhesive is not particularly limited as long as it can enhance the bondability. As the adhesive of the present embodiment, for example, trade names of "Chemlock 218E", "Chemlock 210" and "Chemlock IMB1040" manufactured by Lord Japan Co., Ltd. can be suitably adopted ("Chemlock" is a registered trademark). Other adhesives include, for example, trade names "Metalock C-12" and "Metalock UA" manufactured by Toyo Kagaku Kenkyusho Co., Ltd. ("Metalock" is a registered trademark).

The thickness of the adhesive layer (not shown) can be set as appropriate. The thickness of this embodiment is set smaller than the arithmetic mean roughness Ra of the uneven portion 5 (shown in FIG. 2). As a result, in the laminate 1 of this embodiment, the adhesive layer and the resin body 3 can be made to bite into the recesses 5a of the metal body 2, and the bondability between the metal body 2 and the resin body 3 can be enhanced. can.

The thickness of the adhesive layer in this embodiment is set to 10-100 μm. By setting the thickness to 10 μm or more, the bondability as described above can be enhanced. On the other hand, by setting the thickness to 100 μm or less, it is possible to prevent the adhesive layer from becoming thicker than necessary and to prevent the anchor effect between the metal body 2 and the resin body 3 from being lowered. From such a viewpoint, the thickness is preferably 30 μm or more and preferably 70 μm or less.

In the manufacturing method of this embodiment, prior to the step of bringing the liquid resin 3A into contact with the first surface 4 having the uneven portions 5 (shown in FIG. 3C), the first surface 4 having the uneven portions 5 is formed. A step of applying an adhesive (not shown) to the surface 4 is performed. The adhesive is applied with the above thickness.

Furthermore, in the manufacturing method of this embodiment, a step of preheating the adhesive applied to the first surface 4 is performed in order to improve the adhesive strength of the adhesive (not shown). For preheating the adhesive, for example, a heater (not shown) provided separately from the mold 11 shown in FIG. 3B is used. The temperature of the adhesive is desirably set at 30 to 100° C., for example. Also, the preheating time is desirably set to, for example, 10 to 30 minutes.

Next, in the method of manufacturing the laminate of this embodiment, as shown in FIG. be done.

Next, in the manufacturing method of the laminate of this embodiment, as shown in FIG. (ejected). Thereby, in this embodiment, the liquid resin 3A can be brought into contact with the first surface 4 coated with an adhesive (not shown), and the adhesive and the resin 3A can be made to bite into the concave portion 5a. It becomes possible. In the method of manufacturing the laminate of this embodiment, the first surface 4 of the metal body 2 is bonded to the resin body 3 via the adhesive layer by curing the resin 3A and the adhesive. be.

[Airless tire]
Next, an airless tire including the laminate 1 will be described.
FIG. 4 is a partial front view of the heiress tire of this embodiment as seen from the axle direction. As shown in FIG. 4, the airless tire 16 includes a hub portion 17 fixed to an axle, an annular tread ring 18 for contacting the ground, and spoke portions 19 connecting the hub portion 17 and the tread ring 18. and

The hub portion 17 is made of, for example, a metal material.

The tread ring 18 is made of vulcanized rubber. The tread ring 18 may include, for example, a reinforcement cord layer 25 (indicated by dashed lines) inside in order to increase its circumferential rigidity and the like.

The spoke portion 19 of the present embodiment integrally includes, for example, an outer portion 21 on the outer side in the tire radial direction, an inner portion 22 on the inner side in the tire radial direction, and a plurality of spoke elements 23 .

The outer portion 21 is an annular body joined to the inner peripheral surface of the tread ring 18 . The inner portion 22 is an annular body joined to the outer peripheral surface of the hub portion 17 . Each spoke element 23 extends in the tire radial direction between the outer portion 21 and the inner portion 22 to connect them to each other.

In this embodiment, the metal body 2 (shown in FIG. 1) of the laminate 1 forms the hub portion 17, and the resin body 3 (shown in FIG. 1) of the laminate 1 forms the spoke portion 19 (inner portion 22). forming Therefore, the laminated body 1 is utilized for the heiress tire 16 of this embodiment.

With the above configuration, the laminate 1 can improve the bondability between the metal body 2 (hub portion 17) and the resin body 3 (spoke portion 19). Thereby, the heiress tire 16 of this embodiment can increase the joint strength between the hub portion 17 and the spoke portion 19 (the inner portion 22), and can improve the durability.

[Manufacturing method of airless tire]
Next, a method for manufacturing the heiress tire 16 of the present embodiment (hereinafter sometimes simply referred to as "manufacturing method") will be described.

In the manufacturing method of this embodiment, first, a step of preparing the hub portion 17 (metal body 2) is performed. In this step, the uneven portion 5 (shown in FIG. 2) is formed on the first surface 4 of the hub portion 17 that is joined to the spoke portion 19 (resin body 3). The uneven portion 5 is formed based on the same procedure as the method for manufacturing the laminate 1 .

Next, in the manufacturing method of the present embodiment, a step of vulcanizing and molding the annular tread ring 18 is performed. In this step, a surface treatment layer 24 is formed on the inner peripheral surface of the tread ring 18 . The surface treatment layer 24 is formed by, for example, chlorination treatment.

Next, in the manufacturing method of the present embodiment, a step of setting the hub portion 17 and the tread ring 18 in a mold cavity (both not shown) is performed. An empty space is formed in the cavity of the mold for molding the spoke portion 19 after these members are set.

Next, in the manufacturing method of the present embodiment, a step of melting the resin 3A for forming the spoke portion 19 (resin body 3) is performed. The melting of the resin 3A is performed based on the same procedure as in the method of manufacturing the laminate 1 .

Next, in the manufacturing method of the present embodiment, a step of supplying liquid resin 3A to the empty space of the cavity is performed. Thereby, in this step, the liquid resin 3A can be brought into contact with the first surface 4 having the uneven portion 5 (shown in FIG. 2).

Next, in the manufacturing method of the present embodiment, the heiress tire 16 in which the hub portion 17, the tread ring 18 and the spoke portions 19 are integrated is obtained by curing the resin 3A.

The spoke portion 19 of the present embodiment is directly joined to the hub portion 17 and the tread ring 18 (surface treatment layer 24) without an adhesive layer (not shown) interposed therebetween. As a result, in the manufacturing method of the present embodiment, the step of applying the adhesive and the step of heating the adhesive to cause it to react due to the heating of the adhesive can be eliminated. Furthermore, since the tread ring (vulcanized rubber) 18 is not indirectly heated, deterioration of physical properties of the tread ring 18 can be suppressed.

In the heiress tire 16 of the previous embodiments, the hub portion 17 and the spoke portions 19, and the tread ring 18 (the surface treatment layer 24) and the spoke portions 19 are directly attached without interposing an adhesive layer (not shown). Although bonded, it is not limited to such an embodiment. For example, a layer of adhesive may be interposed to further enhance bonding between them.

Although the particularly preferred embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the illustrated embodiments and can be modified in various ways.

[Example A]
More specific and non-limiting examples of the present disclosure are described below.
Based on the arithmetic mean roughness in Table 1, a sample of a metal body having uneven portions formed on the first surface was prepared. The uneven portions of Comparative Example 1 were formed by shot blasting, and the other uneven portions were formed by laser processing.

A metal body sample was placed in a mold cavity, and a thermoplastic resin was supplied to the empty space of the cavity to mold a resin body. The thickness of the resin layer was adjusted to 2 mm.

After curing the resin layer, the laminate consisting of the metal body and the resin body was taken out from the mold, and a strip-shaped sample with a width of 25 mm and a length of 12 mm was cut out as a sample of the laminate. Common specifications of Examples and Comparative Examples are as follows.
Metal body: Aluminum alloy Ten-point average roughness Rz of uneven part: 614 μm
Resin body: Thermoplastic polyester elastomer resin Adhesive layer: None

Then, a shear force test (T-shaped peel test) was performed in order to evaluate the bonding strength at the interface between the metal body and the resin body in the laminate. The shear force test was conducted in accordance with JIS K 6854 under a room temperature environment of 23° C. and a humidity of 55% and under a high temperature environment (80° C.).
The results of the tests are shown in Table 1.

As a result of the test, in the shear force test (room temperature and 80° C.), the laminate of the example had material failure in the resin body, and peeling did not occur at the interface between the metal body and the resin body. On the other hand, in Comparative Examples 1 to 3, interfacial peeling occurred between the metal body and the resin body in the shear force test (room temperature and 80° C.). Table 1 shows the shear force (N/mm ² ) when interfacial peeling occurred.

As described above, the laminates of Examples in which the arithmetic mean roughness Ra is set to 50 to 150 μm can exhibit an anchoring effect compared to the laminates of Comparative Examples, and the bonding between the metal body and the resin body can be achieved. I was able to improve my performance.

Next, using the laminates in Table 1, airless tires were experimentally produced, and their high-speed durability was evaluated. In the evaluation of high-speed durability, a load of 2.6 kN was applied to the airless tire using a drum tester, and after starting rolling at an initial speed of 100 km / h, 10 km / h every 10 minutes. Increased speed. Then, the maximum value of the speed when the airless tire is not damaged is displayed as an index with the value of Example 1 being 100. FIG. A higher value indicates better high-speed durability.

As a result of the test, it was confirmed that the airless tire of the example exhibits superior high-speed durability compared to the airless tire of the comparative example. Therefore, in the example, the bondability between the metal body and the resin body could be improved, and the durability could also be improved.

[Example B]
A laminate having the arithmetic average roughness Ra (102 μm) of Example 3 in Table 1 and the ten-point average roughness Rz in Table 2 was produced (Example 3, Examples 5 to 9). Furthermore, a laminate was produced by bonding the first surface and the resin body with an adhesive layer interposed (Example 10). Then, a shear force test was conducted in order to evaluate the bondability between the metal body and the resin body in these laminates.

Also, using the laminates in Table 2, airless tires were experimentally produced, and their high-speed durability was evaluated. The shear force test and evaluation of high speed durability were performed in the same procedure as in Example A. The common specifications are as described in Example A, except for the arithmetic mean roughness Ra and ten point mean roughness Rz. The results of the tests are shown in Table 2. FIG. 2 is a partially enlarged view of a metal body having uneven portions formed thereon according to Example 3. FIG. FIG. 5 is a partially enlarged view of a metal body having uneven portions formed thereon according to Example 5. FIG.

As a result of the test, the laminate of Example 5, in which the ten-point average roughness Rz was outside the preferred range, was able to improve the bondability compared to the comparative example shown in Table 1 of Example A. Interfacial delamination occurred between the body and the resin body. This is because the laminate of Example 5 shown in FIG. 5 has regions with smaller amplitude of unevenness and recesses that are locally larger than those of the laminate of Example 3 shown in FIG. It is thought that this is because the anchoring effect was not sufficiently achieved. Also, the laminate of Example 9 was able to improve the bondability as compared with the comparative examples shown in Table 1 of Example A, but interfacial peeling occurred between the metal body and the resin body. rice field.

On the other hand, in Examples 3 and 6 to 8, in which the ten-point average roughness Rz is within the preferred range, no peeling occurs at the interface between the metal body and the resin body, and high bondability can be obtained. was confirmed. In addition, in Example 10, the bondability between the metal body and the resin body could be improved by interposing an adhesive layer.

Further, it was confirmed that the heiress tires of Examples 3 and 6 to 8 exhibit superior high-speed durability compared to the heiress tires of Examples 5 and 9. Therefore, in Example 3 and Examples 6 to 8, in which the ten-point average roughness Rz was within the preferable range, the bondability between the metal body and the resin body could be improved, and the durability could also be improved. . Moreover, Example 3, which does not have an adhesive layer, was able to improve high-speed durability compared to Example 10, which has an adhesive layer.

[Example C]
A laminate having the arithmetic average roughness Ra (102 μm) and the ten-point average roughness Rz (614 μm) of Example 3 was prepared based on the melt index and molding shrinkage of the thermoplastic resin in Table 3. (Example 3, Examples 11 to 18). Then, a shear force test was conducted in order to evaluate the bondability between the metal body and the resin body in these laminates.

In addition, using the laminates in Table 3, airless tires were prototyped, and their high-speed durability was evaluated. The shear force test and evaluation of high speed durability were performed in the same procedure as in Example A. The common specifications are as in Example A except for the arithmetic average roughness Ra and the ten-point average roughness Rz. The results of the tests are shown in Table 3.

As a result of the test, Examples 11, 14, and 18, in which the melt index and molding shrinkage rate were outside the preferred ranges, were able to improve bondability compared to the comparative examples shown in Table 1 of Example A. Although it was possible, interfacial peeling occurred between the metal body and the resin body. On the other hand, in Examples 3, 12 to 13, and 16 to 17, in which the melt index and molding shrinkage ratio are within the preferred ranges, no peeling occurred at the interface between the metal body and the resin body, and high bonding was achieved. It was confirmed that the characteristics can be obtained. On the other hand, in Example 15, which had a small molding shrinkage rate, high bondability was obtained, but it was not possible to smoothly remove the mold from the mold.

In addition, the airless tires of Examples 3, 12 to 13, and 16 to 17 exhibited superior high-speed durability compared to the airless tires of Examples 11, 14, and 18. It could be confirmed. Therefore, in Examples 3, 12 to 13, and 16 to 17, in which the melt index and the molding shrinkage ratio are within the preferred ranges, the bondability between the metal body and the resin body can be improved, and durability is also improved. I was able to improve.

[Appendix]
The present disclosure includes the following aspects.

[Present Disclosure 1]
A laminate in which a metal body and a resin body are joined,
The metal body has an uneven portion on a first surface that is bonded to the resin body,
The arithmetic mean roughness Ra of the uneven portion is 50 to 150 μm,
laminate.
[Disclosure 2]
The laminate according to the present disclosure 1, wherein the unevenness has a ten-point average roughness Rz of 300 to 800 μm.
[Disclosure 3]
The laminate according to the present disclosure 1 or 2, wherein the resin body is formed of a thermoplastic resin.
[Disclosure 4]
The laminate according to present disclosure 3, wherein the thermoplastic resin has a melt index of 10 to 50 g/10 minutes.
[Disclosure 5]
5. The laminate according to 3 or 4 of the present disclosure, wherein the molding shrinkage of the thermoplastic resin is 0.1% to 1.0%.
[Disclosure 6]
6. The laminate according to any one of the present disclosures 3 to 5, wherein the thermoplastic resin is a thermoplastic polyester elastomer resin or a thermoplastic polyamide elastomer resin.
[Present Disclosure 7]
7. The laminate according to any one of the present disclosures 1 to 6, wherein the first surface is directly bonded to the resin body without interposing an adhesive layer.
[Disclosure 8]
7. The laminate according to any one of the present disclosures 1 to 6, wherein the first surface is bonded to the resin body with an adhesive layer interposed therebetween.
[Disclosure 9]
An heiress tire comprising the laminate according to any one of the present disclosure 1-8.
[Disclosure 10]
a hub fixed to the axle;
an annular tread ring for ground contact;
a spoke portion connecting the hub portion and the tread ring;
The metal body forms the hub portion,
The heiress tire according to the present disclosure 9, wherein the resin body forms the spoke portion.
[Present Disclosure 11]
A method for manufacturing a laminate according to any one of the present disclosure 1 to 8,
forming the uneven portion on the first surface of the metal body;
melting a resin for forming the resin body;
a step of bringing a liquid resin into contact with the first surface having the uneven portion;
curing the resin in contact with the first surface to join the metal body and the resin body;
A method for manufacturing a laminate.
[Present Disclosure 12]
The resin is a thermoplastic resin,
12. The method for manufacturing a laminate according to the present disclosure 11, wherein the step of contacting the first surface includes bringing the thermoplastic resin in a liquid state of 200 to 300° C. into contact with the first surface.

REFERENCE SIGNS LIST 1 laminate 2 metal body 3 resin body

Claims (12)

A laminate in which a metal body and a resin body are joined,
The metal body has an uneven portion on a first surface that is bonded to the resin body,
The arithmetic mean roughness Ra of the uneven portion is 50 to 150 μm,
laminate. 2. The laminate according to claim 1, wherein the unevenness has a ten-point average roughness Rz of 300 to 800 μm. The laminate according to claim 1 or 2, wherein the resin body is made of a thermoplastic resin. 4. The laminate according to claim 3, wherein the thermoplastic resin has a melt index of 10 to 50 g/10 minutes. 5. The laminate according to claim 3, wherein said thermoplastic resin has a molding shrinkage of 0.1% to 1.0%. The laminate according to any one of claims 3 to 5, wherein the thermoplastic resin is a thermoplastic polyester elastomer resin or a thermoplastic polyamide elastomer resin. 7. The laminate according to any one of claims 1 to 6, wherein said first surface is directly bonded to said resin body without interposing an adhesive layer. 7. The laminate according to any one of claims 1 to 6, wherein said first surface is joined to said resin body with an adhesive layer interposed therebetween. An heiress tire comprising the laminate according to any one of claims 1 to 8. a hub fixed to the axle;
an annular tread ring for ground contact;
a spoke portion connecting the hub portion and the tread ring;
The metal body forms the hub portion,
The heiress tire according to claim 9, wherein the resin body forms the spoke portion. A method for manufacturing a laminate according to any one of claims 1 to 8,
forming the uneven portion on the first surface of the metal body;
melting a resin for forming the resin body;
a step of bringing a liquid resin into contact with the first surface having the uneven portion;
curing the resin in contact with the first surface to join the metal body and the resin body;
A method for manufacturing a laminate. The resin is a thermoplastic resin,
12. The method of manufacturing a laminate according to claim 11, wherein the step of contacting the first surface includes contacting the thermoplastic resin with the first surface in a liquid state of 200 to 300°C.

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