JP2023067437A - Method for manufacturing non-pneumatic tire and non-pneumatic tire - Google Patents

Abstract

To provide a method for manufacturing a non-pneumatic tire and a non-pneumatic tire which can secure adhesive force between a support structure and a tread without using a support structure containing a resin having a specific chemical structure or specific physical properties.SOLUTION: There is provided a method for manufacturing a non-pneumatic tire having a support structure 10 containing a resin, and a tread which is positioned outside the support structure 10 in a tire radial direction X and extends in a tire circumferential direction. The method for manufacturing the non-pneumatic tire includes a step of sequentially applying a first adhesive 2 and a second adhesive 3 to a surface outside the support structure 10 in a tire radial direction X, and vulcanizing and bonding the support structure 10 to which the first adhesive 2 and the second adhesive 3 are sequentially applied, and a rubber composition 4 for the tread. The first adhesive 2 has higher compatibility with the resin contained in the support structure 10 than that of the second adhesive 3, and the second adhesive 3 is a vulcanization adhesive.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for manufacturing a non-pneumatic tire and to a non-pneumatic tire.

Conventionally, a non-pneumatic tire is known that includes a support structure that supports a load from a vehicle, and a tread that is located radially outside the support structure and extends along the tire circumferential direction. .

In a non-pneumatic tire, if the tread peels off from the support structure, the running of the vehicle will be hindered. Therefore, it is desired to secure the adhesive force between the support structure and the tread.

Therefore, in Patent Document 1, it is described that a support structure is produced by curing a polyurethane composition containing an isocyanate-terminated prepolymer having a double bond in the main chain, an organic sulfide, and dimethylthiotoluenediamine. It is

Further, Patent Document 2 describes that the storage elastic modulus at 150° C. of the resin contained in the connecting structure portion connecting the inner annular portion and the outer annular portion of the support structure is set to 8 MPa or more.

Japanese Patent No. 5175587 Japanese Patent Application Laid-Open No. 2019-218002

However, in Patent Documents 1 and 2, it is necessary to use a support structure containing a resin having a specific chemical structure or specific physical properties.

The present invention provides a method for manufacturing a non-pneumatic tire capable of ensuring adhesion between a support structure and a tread without using a support structure containing a resin having a specific chemical structure or specific physical properties. and to provide non-pneumatic tires.

One aspect of the present invention provides a non-pneumatic tire comprising a support structure containing a resin, and a tread located outside the support structure in the tire radial direction and extending along the tire circumferential direction. A manufacturing method, comprising: sequentially applying a first adhesive and a second adhesive to an outer surface of the support structure in the tire radial direction; a step of vulcanizing and bonding a support structure to which an adhesive is sequentially applied and a tread rubber composition, wherein the first adhesive is more resistant to the resin than the second adhesive; Affinity is high, and the second adhesive is a vulcanized adhesive.

The resin may be a urethane resin, the first adhesive may be an epoxy resin adhesive or a urethane resin adhesive, and the second adhesive may contain a halogenated polymer.

The support structure may have an arithmetic mean roughness Ra of 2.0 μm or more and 18.0 μm or less on the outer surface in the tire radial direction.

In the method for manufacturing a non-pneumatic tire described above, the coating film thickness of the second adhesive may be 1.0 μm or more and 23.0 μm or less.

A pressure applied when vulcanizing and bonding the support structure and the tread rubber composition may be 0.6 MPa or more.

Another aspect of the present invention is a non-pneumatic tire comprising: a support structure containing a resin; and a tread located radially outside the support structure and extending along the tire circumferential direction. A tire, wherein a first adhesive and a second adhesive are sequentially applied to the outer surface of the support structure in the tire radial direction, and then the support structure, a tread rubber composition, The first adhesive has a higher affinity for the resin than the second adhesive, and the second adhesive is a vulcanized adhesive be.

According to the present invention, there is provided a non-pneumatic tire capable of ensuring adhesion between a support structure and a tread without using a support structure containing a resin having a specific chemical structure or specific physical properties. A manufacturing method and a non-pneumatic tire can be provided.

It is a side view which shows the non-pneumatic tire of this embodiment. FIG. 2 is a cross-sectional view showing an example of a method of manufacturing the non-pneumatic tire of FIG. 1; FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1; FIG. 4 is a partial perspective view of a non-pneumatic tire viewed obliquely from the portion shown in FIG. 3;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

A method for manufacturing a non-pneumatic tire according to the present embodiment includes a support structure containing a resin, and a tread located outside the support structure in the tire radial direction and extending along the tire circumferential direction. A method for manufacturing a non-pneumatic tire.

FIG. 1 shows a non-pneumatic tire of this embodiment. A non-pneumatic tire 1 comprises a support structure 10 and a tread 50 . Here, the support structure 10 contains resin and supports the load from the vehicle. Further, the tread 50 is located outside the support structure 10 in the tire radial direction X and extends along the tire circumferential direction C. As shown in FIG. Details of the structure of the non-pneumatic tire 1 will be described later.

FIG. 2 shows an example of a method for manufacturing the non-pneumatic tire 1. As shown in FIG. When manufacturing the non-pneumatic tire 1, first, the first adhesive 2 and the second adhesive 3 are sequentially applied to the outer surface of the support structure 10 in the tire radial direction X. As shown in FIG.

The coating film thickness of the first adhesive 2 is not particularly limited, but is, for example, 10 μm or more and 30 μm or less.

The coating film thickness of the second adhesive 3 is preferably 1.0 μm or more and 23.0 μm or less, more preferably 5.0 μm or more and 20.0 μm or less. When the coating film thickness of the second adhesive 3 is 1.0 μm or more and 23.0 μm or less, the adhesion between the support structure 10 and the tread 50 is improved.

The first adhesive 2 and the second adhesive 3 may be dried if necessary. The drying conditions are not particularly limited, but are, for example, a temperature of 50° C. or higher and 80° C. or lower for 5 minutes or longer and 10 minutes or shorter.

At this time, after applying the first adhesive 2 and after applying the second adhesive 3, the first adhesive 2 and the second adhesive 3 may be dried respectively, or the first adhesive 2 and the second adhesive 3 may be dried. After applying the adhesive 2 and the second adhesive 3, the first adhesive 2 and the second adhesive 3 may be dried.

Next, the tread rubber composition 4 is adhered to the surface of the support structure 10 to which the first adhesive 2 and the second adhesive 3 are sequentially applied, and then heated and vulcanized using a vulcanizing device. By pressing, the support structure 10 and the tread rubber composition 4 are vulcanized and bonded.

The pressure applied when vulcanizing and bonding the support structure 10 and the tread rubber composition 4 is preferably 0.6 MPa or more, more preferably 0.8 MPa or more. When the pressure is 0.6 MPa or more when the support structure 10 and the tread rubber composition 4 are vulcanized and adhered, the adhesion between the support structure 10 and the tread 50 is improved.

Here, the first adhesive 2 has a higher affinity for the resin contained in the support structure 10 than the second adhesive 3, and the second adhesive 3 is a vulcanization adhesive. Therefore, the compatibility between the resin contained in the support structure 10 and the first adhesive 2 and the compatibility between the first adhesive 2 and the second adhesive 3 are improved. Adhesion between the support structure 10 and the tread 50 can be ensured without using a support structure containing a resin having a chemical structure or specific physical properties. On the other hand, if the first adhesive 2 is not applied, the compatibility between the support structure 10 and the second adhesive 3 is poor, resulting in a specific chemical structure or specific physical properties. A support structure containing resin must be used.

The material forming the outer surface of the support structure 10 in the tire radial direction X is not particularly limited, but examples thereof include thermoplastic elastomers, crosslinked rubbers, and other resins.

Here, when the resin constituting the outer surface in the tire radial direction X of the support structure 10 is a urethane resin, the first adhesive 2 is an epoxy resin adhesive or a urethane resin adhesive, and the second Adhesive 3 can be a vulcanized adhesive comprising a halogenated polymer. At this time, the second adhesive 3 may further contain a metal oxide (acid acceptor) as necessary.

Here, the epoxy resin-based adhesive and the urethane resin-based adhesive are adhesives containing epoxy resin and urethane resin as main components, respectively.

As the urethane resin, a known urethane resin used for support structures can be used. As the epoxy resin-based adhesive or urethane resin-based adhesive, a known epoxy resin-based adhesive or urethane resin-based adhesive can be used. Furthermore, as the halogenated polymer and metal oxide (acid acceptor), known halogenated polymers and metal oxides (acid acceptors) used for vulcanizing adhesives can be used, respectively.

Note that the first adhesive 2 may be a primer.

The tread rubber composition 4 includes, but is not limited to, natural rubber and carbon black, and may further include sulfur, silica, and the like. Here, the tread rubber composition 4 may contain synthetic rubber such as polyisoprene rubber and styrene-butadiene rubber together with natural rubber or instead of natural rubber.

The tread rubber composition 4 may be either an unvulcanized rubber composition or a vulcanized rubber composition.

The vulcanization temperature is not particularly limited, but is, for example, 140° C. or higher and 180° C. or lower.

The arithmetic mean roughness Ra of the outer surface in the tire radial direction X of the support structure 10 is preferably 2.0 μm or more and 18.0 μm or less, and more preferably 5.0 μm or more and 18.0 μm or less. When the arithmetic mean roughness Ra of the outer surface of the support structure 10 in the tire radial direction X is 2.0 μm or more and 18.0 μm or less, the adhesion between the support structure 10 and the tread 50 is improved.

A method for adjusting the surface roughness of the outer surface of the support structure 10 in the tire radial direction X is not particularly limited, but examples thereof include buffing. In this case, the buffed side of the support structure 10 is preferably degreased and washed.

The details of the structure of the non-pneumatic tire 1 (see FIG. 1) will be described below. FIG. 1 is a side view of the non-pneumatic tire 1 of the present embodiment viewed from a direction parallel to the tire rotation axis (tire meridian), that is, from a direction along the front and back direction of the paper in FIG. The non-pneumatic tire 1 shown in FIG. 1 is in an unloaded state. FIG. 3 is a cross-sectional view taken along line II-II of FIG. FIG. 4 is a partial perspective view of the non-pneumatic tire 1, obliquely viewing the portion shown in FIG.

1 and 4, arrow C indicates the tire circumferential direction. 1, 3 and 4, the arrow X indicates the tire radial direction. 3 and 4, arrow Y indicates the tire width direction. The tire width direction Y in FIG. 1 is the front-back direction of the paper surface. Symbol E in FIG. 3 is the tire equatorial plane. The tire circumferential direction C in FIG. 3 is the front-back direction of the paper surface.

The tire circumferential direction C is the direction around the tire rotation axis and the same direction as the direction in which the non-pneumatic tire 1 rotates. The tire radial direction X is a direction perpendicular to the tire rotation axis. The tire width direction Y is a direction parallel to the tire rotation axis. 3 and 4, one side in the tire width direction Y is indicated as Y1, and the other side in the tire width direction Y is indicated as Y2. The tire equatorial plane E shown in FIG. 3 is a plane orthogonal to the tire rotation axis and located at the center in the tire width direction Y. As shown in FIG.

The non-pneumatic tire 1 of this embodiment comprises an inner annular portion 20 , an outer annular portion 30 , a support structure 10 having a plurality of spokes 40 and a tread 50 . Therefore, the outer surface in the tire radial direction X of the support structure 10 is the outer surface in the tire radial direction X of the outer annular portion 30 .

In the following, the thickness of the inner annular portion 20 and the outer annular portion 30 is the dimension along the tire radial direction X. As shown in FIG. The widths of the inner annular portion 20 and the outer annular portion 30 are dimensions along the tire width direction Y shown in FIG.

The inner annular portion 20 is an annular portion along the tire circumferential direction C that constitutes the inner peripheral portion of the non-pneumatic tire 1 . The thickness and width of the inner annular portion 20 are set constant to improve uniformity. A tire wheel (not shown) is arranged in a space on the inner peripheral side of the inner annular portion 20 . The inner peripheral portion of the inner annular portion 20 is fitted and attached to the outer peripheral portion of the rim of the tire wheel. With the inner annulus 20 mounted on the rim, the non-pneumatic tire 1 is mounted on the tire wheel. The inner peripheral surface of the inner annular portion 20 may be provided with a fitting portion configured by a protrusion, a groove, or the like for fitting with the rim.

The inner annular portion 20 can be made of, for example, an elastic resin material, but the material is not limited to resin.

The inner annular portion 20 transmits the rotation of the tire wheel to the spokes 40 and the outer annular portion 30 . The thickness of the inner annular portion 20 is determined from the viewpoint of achieving weight reduction and durability while satisfying the function of sufficiently transmitting the torque to the spokes 40 . Although the thickness of the inner annular portion 20 is not particularly limited, it is preferably 2% or more and 7% or less, and more preferably 3% or more and 6% or less, of the tire cross-sectional height H shown in FIG.

The inner diameter of the inner annular portion 20 is determined according to the dimensions of the rim of the tire wheel on which the non-pneumatic tire 1 is mounted, the application of the vehicle, and the like. For example, when assuming a substitute for a general pneumatic tire, the inner diameter of the inner annular portion 20 may be, for example, 250 mm or more and 500 mm or less, but is not limited to this.

The width of the inner annular portion 20 is appropriately determined according to the application of the vehicle on which the non-pneumatic tire 1 is mounted, the length of the axle, and the like. For example, when assuming a substitute for a general pneumatic tire, the width of the inner annular portion 20 may be 100 mm or more and 300 mm or less, but is not limited to this.

The outer annular portion 30 is an annular portion along the tire circumferential direction C that constitutes the outer peripheral portion of the non-pneumatic tire 1 . The outer annular portion 30 is arranged concentrically with the inner annular portion 20 on the outer peripheral side of the inner annular portion 20 . The thickness and width of the outer annular portion 30 are set constant to improve uniformity.

Outer annular portion 30 transmits the rotation of inner annular portion 20 and spokes 40 to the road surface via tread 50 . The thickness of the outer annular portion 30 is determined from the viewpoint of achieving weight reduction and durability while satisfying the function of sufficiently transmitting the torque from the spokes 40 to the road surface. Although the thickness of the outer annular portion 30 is not particularly limited, it is preferably 2% or more and 7% or less, and more preferably 2% or more and 5% or less, of the tire cross-sectional height H shown in FIG.

The inner diameter of the outer annular portion 30 is appropriately determined according to the dimensions of the rim of the tire wheel on which the non-pneumatic tire 1 is mounted, the application of the vehicle, and the like. For example, when assuming a substitute for a general pneumatic tire, the inner diameter of the outer annular portion 30 may be 420 mm or more and 750 mm or less, but is not limited to this.

The width of the outer annular portion 30 is appropriately determined according to the application of the vehicle on which the non-pneumatic tire 1 is mounted. For example, when assuming a substitute for a general pneumatic tire, the width of the outer annular portion 30 may be 100 mm or more and 300 mm or less, but is not limited to this.

A plurality of spokes 40 connect the inner annular portion 20 and the outer annular portion 30 . The inner annular portion 20 and the outer annular portion 30 connected by a plurality of spokes 40 are arranged concentrically with each other. Each of the plurality of spokes 40 is arranged independently along the tire circumferential direction C. As shown in FIG. As shown in FIG. 1 , when the non-pneumatic tire 1 is in an unloaded state, the plurality of spokes 40 extend linearly in the radial direction substantially parallel to the tire radial direction X when viewed from the side.

As shown in FIGS. 3 and 4 , the plurality of spokes 40 of this embodiment includes a plurality of first spokes 41 and a plurality of second spokes 42 . Neither the first spoke 41 nor the second spoke 42 extends parallel to the tire radial direction X when viewed along the tire circumferential direction C. The first spokes 41 are inclined to one side in the tire axial direction, that is, the tire width direction Y. As shown in FIG. The second spokes 42 are slanted opposite to the first spokes 41 . The first spokes 41 and the second spokes 42 are alternately arranged in the tire circumferential direction C. As shown in FIG.

Specifically, as shown in FIGS. 3 and 4 , the first spokes 41 are arranged from the Y1 side, which is one side of the outer annular portion 30 in the tire width direction Y, to the other side of the inner annular portion 20 in the tire width direction Y. It extends obliquely toward the Y2 side. The second spokes 42 extend obliquely from the Y2 side, which is the other side in the tire width direction Y, of the outer annular portion 30 toward the Y1 side, which is one side of the inner annular portion 20 in the tire width direction Y. .

The inclination angles of the first spoke 41 and the second spoke 42 are the same. Therefore, the first spoke 41 and the second spoke 42 adjacent to each other in the tire circumferential direction C are arranged in a substantially X shape when viewed along the tire circumferential direction C. As shown in FIG. As shown in FIG. 3, the first spokes 41 and the second spokes 42 are inclined at an angle θ with respect to the tire width direction Y, and the angle θ is, for example, 15° or more and 50° or less. is preferred.

As shown in FIG. 3 , each of the first spokes 41 and the second spokes 42 has the same shape symmetrical with respect to the tire equatorial plane E when viewed in the tire circumferential direction C. As shown in FIG. Therefore, hereinafter, the first spokes 41 and the second spokes 42 are collectively referred to as the spokes 40 when there is no need to distinguish between the first spokes 41 and the second spokes 42 and they can be collectively described. .

The spokes 40 are plate-shaped and extend obliquely from the inner annular portion 20 toward the outer annular portion 30 at the angle θ as described above. As shown in FIG. 4 , the spoke 40 has a plate thickness t along the tire circumferential direction smaller than a plate width w, and the direction of the plate thickness t is along the tire circumferential direction C. As shown in FIG. That is, the spokes 40 are formed in a plate shape extending along the plane in the tire radial direction X and the tire width direction Y. As shown in FIG. The plate width w here is the dimension in the direction perpendicular to the direction of inclination in which the spokes 40 extend when the spokes 40 are viewed from the direction along the tire circumferential direction C, as shown in FIG. be. In this embodiment, all the spokes 40 have the same plate thickness t. Moreover, the plate width w of all the spokes 40 is the same.

Since the spokes 40 have a long plate shape, even if the plate thickness t is reduced, the durability of the spokes 40 can be improved by setting the plate width w wide. Furthermore, by reducing the plate thickness t and increasing the number of spokes 40, it is possible to reduce the interval between the spokes 40 adjacent in the tire circumferential direction C while maintaining the rigidity of the non-pneumatic tire 1 as a whole. As a result, the contact pressure caused by the spokes 40 when the tire rolls is dispersed, and the contact pressure can be reduced.

Although the spokes 40 of the present embodiment are parallel to the tire radial direction X when viewed from the side, the spokes 40 are arranged obliquely with respect to the tire radial direction X so as to intersect with the tire radial direction X when viewed from the side. good too.

As shown in FIGS. 3 and 4, the first spokes 41 include a first inner connecting portion 411 connected to the inner annular portion 20 on the Y2 side in the tire width direction, and a first inner connecting portion 411 connected to the Y1 side of the outer annular portion 30 in the tire width direction. and a connecting first outer connection portion 412 . The second spoke 42 includes a second inner connecting portion 421 connected to the inner annular portion 20 on the Y1 side in the tire width direction, and a second outer connecting portion 422 connected to the Y2 side in the tire width direction of the outer annular portion 30. , has Each of the first outer connection portion 412 and the second outer connection portion 422 is an example of a connection portion of the spokes 40 connected to the outer annular portion 30 in this embodiment.

As shown in FIG. 3 , the first inner connecting portion 411 of the first spoke 41 has a shape that widens along the tire width direction Y as it approaches the inner annular portion 20 . A side surface 411a of the first inner connecting portion 411 on the tire width direction Y2 side extends to the end portion 20b of the inner annular portion 20 on the tire width direction Y2 side while gently curving. A side surface 411b on the tire width direction Y1 side of the first inner connection portion 411 extends to the position of the tire equatorial plane E of the inner annular portion 20 while curving toward the tire width direction Y1 side.

The first outer connecting portion 412 of the first spoke 41 has the same shape as the first inner connecting portion 411, and has a shape that widens along the tire width direction as it approaches the outer annular portion 30. . A side surface 412a of the first outer connecting portion 412 on the tire width direction Y1 side extends to the end portion 30a of the outer annular portion 30 on the tire width direction Y1 side while gently curving. A side surface 412b of the first outer connection portion 412 on the tire width direction Y2 side extends to the position of the tire equatorial plane E of the outer annular portion 30 while curving toward the tire width direction Y2 side.

The first inner connection portion 411 is provided in a half region of the inner annular portion 20 on the tire width direction Y2 side. The first outer connection portion 412 is provided in a half region of the outer annular portion 30 on the tire width direction Y1 side.

As shown in FIG. 3 , the second inner connecting portion 421 of the second spoke 42 has a shape that widens along the tire width direction Y as it approaches the inner annular portion 20 . A side surface 421a of the second inner connection portion 421 on the tire width direction Y1 side extends to the end portion 20a of the inner annular portion 20 on the tire width direction Y1 side while being gently curved. A side surface 421b of the second inner connection portion 421 on the tire width direction Y2 side extends to the position of the tire equatorial plane E of the inner annular portion 20 while curving toward the tire width direction Y2 side.

The second outer connecting portion 422 of the second spoke 42 has the same shape as the second inner connecting portion 421, and has a shape that widens in the tire width direction as it approaches the outer annular portion 30. there is A side surface 422a of the second outer connection portion 422 on the tire width direction Y2 side extends to the end portion 30b of the outer annular portion 30 on the tire width direction Y2 side while gently curving. A side surface 422b of the second outer connection portion 422 on the tire width direction Y1 side extends to the position of the tire equatorial plane E of the outer annular portion 30 while curving toward the tire width direction Y1 side.

The second inner connecting portion 421 is provided in a half region of the inner annular portion 20 on the tire width direction Y1 side. The second outer connection portion 422 is provided in a half region of the outer annular portion 30 on the tire width direction Y2 side.

As described above, all the spokes 40 of this embodiment have the same plate thickness t. The dimension of the plate thickness t is not particularly limited. , preferably 1 mm or more and 30 mm or less, more preferably 5 mm or more and 25 mm or less.

As described above, all the spokes 40 of this embodiment have the same plate width w. The plate width w of the spokes 40 is not particularly limited, but in order to sufficiently receive the rotational force from the inner annular portion 20 and the outer annular portion 30 and to allow moderate bending deformation when receiving a load, It is preferably 5 mm or more and 25 mm or less, more preferably 10 mm or more and 20 mm or less. In addition, the plate width w is preferably 110% or more of the plate thickness t, more preferably 115% or more, from the viewpoint of improving the durability and dispersing the contact pressure.

The number of spokes 40 is 80 or more and 300 or less from the viewpoint of enabling weight reduction while sufficiently supporting the load from the vehicle and improving power transmission performance and durability. , and more preferably 100 or more and 200 or less.

The dimension of the spokes 40 in the tire radial direction X may be 26.8 mm or more and 357.5 mm or less, but is not limited to this.

Spokes 40 may be formed from any of the elastic materials listed below. First, as the characteristics of the elastic material, the tensile stress at 10% elongation when a tensile test is performed according to JIS K7312: 1996 from the viewpoint of imparting appropriate rigidity while ensuring sufficient durability. is preferably 50 MPa or more and 120 MPa or less, more preferably 70 MPa or more and 105 MPa or less.

If the Young's modulus of the spokes 40 is less than 50 MPa, sufficient rigidity may not be obtained, and the spokes 40 adjacent in the tire circumferential direction C may come into contact with each other. On the other hand, when the Young's modulus of the spokes 40 exceeds 120 MPa, the rigidity becomes excessively high, degrading the ride comfort.

Examples of the elastic material used as the base material of the spokes 40 include thermoplastic elastomers, crosslinked rubbers, and other resins.

Examples of thermoplastic elastomers include polyester elastomers, polyolefin elastomers, polyamide elastomers, polystyrene elastomers, polyvinyl chloride elastomers, polyurethane elastomers, and the like.

Either natural rubber or synthetic rubber can be used as the rubber material constituting the crosslinked rubber. Synthetic rubbers include styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IIR), nitrile rubber (NBR), hydrogenated nitrile rubber (hydrogenated NBR), chloroprene rubber (CR), ethylene propylene rubber ( EPDM), fluorine rubber, silicone rubber, acrylic rubber, urethane rubber, and the like. These rubber materials may be used in combination of two or more as needed.

Other resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include polyethylene resins, polystyrene resins, and polyvinyl chloride resins. Thermosetting resins include epoxy resins, phenol resins, polyurethane resins, silicone resins, polyimide resins, melamine resins, and the like.

Among the above elastic materials, urethane resin is preferably used for the spokes 40 from the viewpoint of moldability, workability and cost. A foam material can also be used as the elastic material. That is, foamed thermoplastic elastomers, crosslinked rubbers, and other resins can be used.

The elastic material used as the base material of the spokes 40 may be reinforced with reinforcing fibers. Examples of reinforcing fibers include long fibers, short fibers, woven fabrics, non-woven fabrics, and the like. Reinforcing fibers include rayon cords, polyamide cords such as nylon-6,6, polyester cords such as polyethylene terephthalate, aramid cords, glass fiber cords, carbon fibers, and steel cords.

Reinforcement of the elastic material is not limited to reinforcement with reinforcing fibers. For example, reinforcement by the addition of particulate fillers may be provided. Granular fillers to be added include carbon black, silica, ceramics such as alumina, fillers of other inorganic materials, and the like.

By the way, the inner annular portion 20 and the outer annular portion 30 described above are preferably formed of the same resin material as the spokes 40. In that case, for example, the inner annular portion 20 and the outer annular portion 20 are formed by cast molding. 30 and spokes 40 can be integrally molded.

The tread 50 is provided on the outer peripheral surface of the outer annular portion 30 and constitutes the outermost peripheral portion of the non-pneumatic tire 1 . The tread 50 is formed by vulcanizing and bonding the support structure 10 and the tread rubber composition 4, as described above. The tread 50 has a tread surface 51 that contacts the road surface on its outer peripheral surface. A tread 51 of the tread 50 is provided with a tread pattern formed of a plurality of grooves and land portions in the same manner as a conventional pneumatic tire.

Note that the tread 50 may have a structure in which a plurality of vulcanized rubber layers having different components and properties are laminated (for example, two layers or three layers).

Moreover, the non-pneumatic tire 1 of the present embodiment may further include a reinforcing layer (not shown). The reinforcing layer may be embedded in the outer annular portion 30 . Alternatively, a reinforcing layer may be provided between the outer annular portion 30 and the tread 50 . The reinforcing layer is a cylindrical layer extending along the tire circumferential direction C. As shown in FIG.

The reinforcing layer is evenly arranged over the entire circumference of the tire in order to suppress the occurrence of buckling in which the outer annular portion 30 is bent in the tire radial direction X at the center portion in the tire width direction Y. The reinforcing layer is configured by, for example, steel cords arranged substantially parallel to the tire width direction Y. As shown in FIG. A cylindrical metal ring, a high modulus resin ring, or the like may be used as the reinforcing layer. For example, as the reinforcing layer, a ring made of fiber reinforced plastic (FRP) such as carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP) may be used.

By providing the reinforcing layer, the rigidity of the non-pneumatic tire 1 is ensured, and the ground contact of the tread 50 to the road surface is improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and the above embodiments may be changed as appropriate within the scope of the present invention.

Examples of the present invention will be described below, but the present invention is not limited to the examples. Since it is difficult to directly measure the adhesion between the support structure and the tread using a non-pneumatic tire, a test piece simulating a non-pneumatic tire was used to measure the adhesion.

[Example 1]
A urethane resin sheet having a width of 100 mm, a length of 200 mm, and a thickness of 2.0 mm was coated with a sanding belt having a particle size of #80 and a belt sander from one end of a urethane resin sheet with a length of 100 mm. A buffing process was carried out so as to obtain a thickness of 0.2 μm. Next, after air blowing the bonding area, it was degreased and washed with ethanol. Next, using a brush, an epoxy resin adhesive Chemlok (registered trademark) 210 (manufactured by LOAD) as a first adhesive was applied to the adhesion area, and then dried at 80° C. for 10 minutes. Next, using a brush, a vulcanizing adhesive Chemlok 6108S (manufactured by LOAD) containing a halogenated polymer and a metal oxide (acid acceptor) as a second adhesive was applied to the adhesive area, and then heated to 80°C. and dried for 10 minutes. Next, after the unvulcanized rubber composition was adhered to the adhesion region, vulcanization adhesion was performed under the conditions of a pressure of 1 MPa, a heating temperature of 140° C., and a heating and pressing time of 36 minutes. Next, it was cut into a width of 25 mm and a length of 150 mm to obtain a test piece.

[Comparative Example 1]
A test piece was obtained in the same manner as in Example 1, except that the first adhesive was not used.

[Comparative Example 2]
A test piece was obtained in the same manner as in Example 1, except that a phenolic resin adhesive Chemlok 205 (manufactured by LOAD) was used as the first adhesive.

[Comparative Example 3]
A test piece was obtained in the same manner as in Example 1, except that a phenolic resin adhesive Chemlok 218E (manufactured by LOAD) was used as the first adhesive.

[Arithmetic mean roughness Ra of adhesive region]
The arithmetic mean roughness Ra of the adhesion region was measured using a contact-type surface roughness meter.

[Coating Film Thickness of First Adhesive and Second Adhesive]
The coating film thicknesses of the first adhesive and the second adhesive were calculated by dividing the dry weight of the applied adhesive by the dry specific gravity and the coating area.

[T-type peel test]
With reference to JIS K6854-3:1999, a T-type peel test was performed at room temperature to measure the average peel strength of the test piece.

Table 1 shows the test piece preparation conditions and the measurement results of the average peel strength.

From Table 1, it can be seen that the test piece of Example 1 has a high average peel strength. On the other hand, the test piece of Comparative Example 1 had a low average peel strength because the first adhesive was not applied. In addition, since the test pieces of Comparative Examples 2 and 3 used the phenolic resin adhesive as the first adhesive, the affinity of the first adhesive to the urethane resin sheet was the same as that of the urethane resin sheet of the second adhesive. and lower average peel force.

REFERENCE SIGNS LIST 1 non-pneumatic tire 1A non-pneumatic tire precursor 2 first adhesive 3 second adhesive 4 tread rubber composition 10 support structure 20 inner annulus 20a, 20b end 30 outer annulus 30a, 30b end Part 40 Spokes 41 First spokes 42 Second spokes 411 First inner connection parts 411a, 411b Side surfaces 412 First outer connection parts 412a, 412b Side surfaces 421 Second inner connection parts 421a, 421b Side surfaces 422 Second inner connection parts Outer connecting portion 422a, 422b Side surface 50 Tread 51 Tread surface 60 Vulcanizer 61 Lower die 62 Upper die 63, 64 Segments 63a, 64a Molding surface 65, 66 Packing C Tire circumferential direction E Tire equatorial plane O Shaft center X Tire radial direction Y tire width direction

Claims (6)

A method for manufacturing a non-pneumatic tire comprising a support structure containing a resin and a tread positioned radially outwardly of the support structure and extending along the tire circumferential direction, the method comprising:
a step of sequentially applying a first adhesive and a second adhesive to the outer surface of the support structure in the tire radial direction;
vulcanization adhesion of the support structure to which the first adhesive and the second adhesive are sequentially applied and the tread rubber composition,
The first adhesive has a higher affinity for the resin than the second adhesive,
The method of manufacturing a non-pneumatic tire, wherein the second adhesive is a vulcanizing adhesive. The resin is a urethane resin,
the first adhesive is an epoxy resin-based adhesive or a urethane resin-based adhesive;
2. The method of manufacturing a non-pneumatic tire according to claim 1, wherein said second adhesive comprises a halogenated polymer. The method of manufacturing a non-pneumatic tire according to claim 1 or 2, wherein the support structure has an arithmetic mean roughness Ra of 2.0 µm or more and 18.0 µm or less on the outer surface in the tire radial direction. The method for manufacturing a non-pneumatic tire according to any one of claims 1 to 3, wherein the coating film thickness of the second adhesive is 1.0 µm or more and 23.0 µm or less. 5. The manufacturing of the non-pneumatic tire according to any one of claims 1 to 4, wherein the pressure applied when vulcanizing and bonding the support structure and the tread rubber composition is 0.6 MPa or more. Method. A non-pneumatic tire comprising a support structure containing a resin, and a tread positioned radially outward of the support structure and extending along the tire circumferential direction,
After sequentially applying a first adhesive and a second adhesive to the outer surface of the support structure in the tire radial direction, the support structure and the tread rubber composition are vulcanized and bonded. It is manufactured by
The first adhesive has a higher affinity for the resin than the second adhesive,
The non-pneumatic tire, wherein the second adhesive is a vulcanizing adhesive.

Images