Non-pneumatic tire and method for manufacturing a non-pneumatic tire

Abstract

The objective is to provide a non-pneumatic tire with improved electrostatic properties. [Solution] A non-pneumatic tire 1 comprising an inner cylinder 2 fitted onto a wheel, an outer cylinder 3 surrounding the inner cylinder 2 from the outside in the tire radial direction, a plurality of connecting members 4 arranged between the inner cylinder 2 and the outer cylinder 3 along the tire circumferential direction and connecting the two cylinders, and a tread member 5 provided on the outer side of the outer cylinder 3 in the tire radial direction, wherein the inner cylinder 2, outer cylinder 3 and connecting members 4 are made of a resin composition, and at least the connecting members 4 have a conductive rubber layer 6 provided so as to be connected across the inner cylinder 2 and the outer cylinder 3, the conductive rubber layer 6 contains diene rubber and carbon black, and the carbon black content is 50 parts by mass or more per 100 parts by mass of diene rubber.

Description

Technical Field

[0001] The present disclosure relates to a non-pneumatic tire and a method for manufacturing the non-pneumatic tire.

Background Art

[0002] In recent years, in order to avoid the occurrence of punctures, tires that do not require filling with pressurized air inside have been proposed.

[0003] For example, in Patent Document 1 below, an airless tire includes an annular tread portion that contacts the road surface, an annular inner peripheral portion that is located inside the tread portion in the tire radial direction and contacts a conductive wheel, and a plurality of connecting portions that connect the tread portion and the inner peripheral portion. The tread portion includes a first portion that contacts the road surface and has conductivity, and a second portion on the inner peripheral portion side of the first portion. It is disclosed that the second portion, the connecting portion, and the inner peripheral portion are formed of a resin containing carbon short fibers. Further, in Patent Document 2 below, an airless tire includes an annular tread portion that contacts the road surface, an annular inner peripheral portion that is located inside the tread portion in the tire radial direction and is connected to a conductive wheel, and a plurality of connecting portions that connect the tread portion and the inner peripheral portion. The tread portion includes a first portion that contacts the road surface and has conductivity, and a second portion inside the first portion in the tire radial direction. It is disclosed that the second portion, the connecting portion, and the inner peripheral portion are formed of a resin containing carbon black.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-mentioned Patent Documents 1 and 2, conductive materials such as carbon short fibers and carbon black are incorporated into tire frame members such as connecting members to improve the conductivity of the tire frame members and thereby improve the electrostatic properties of non-pneumatic tires. As described in Patent Documents 1 and 2 above, incorporating conductive materials into tire frame members can improve conductivity, but on the other hand, it can significantly affect the physical properties of non-pneumatic tires. While the influence of such material incorporation on the physical properties of non-pneumatic tires can be suppressed to some extent by controlling the amounts of various materials used, there are limits to how much this influence can be suppressed. Therefore, other means are needed to improve the electrostatic properties of non-pneumatic tires.

[0006] Therefore, the object of this disclosure is to solve the problems of the above-mentioned prior art and to provide a non-pneumatic tire with improved electrostatic properties and a method for manufacturing the same. [Means for solving the problem]

[0007] The gist of the present invention, which solves the above problems, is as follows.

[0008] [1] A non-pneumatic tire comprising: an inner cylinder fitted to a wheel; an outer cylinder surrounding the inner cylinder from the outside in the tire radial direction; a plurality of connecting members arranged between the inner cylinder and the outer cylinder along the tire circumferential direction for connecting the two cylinders; and a tread member provided on the outer side of the outer cylinder in the tire radial direction, The inner cylinder, the outer cylinder, and the connecting member are made of a resin composition. At least the connecting member has a conductive rubber layer provided so as to connect the inner cylinder and the outer cylinder, The conductive rubber layer comprises a diene-based rubber and carbon black. A non-pneumatic tire in which the carbon black content is 50 parts by mass or more per 100 parts by mass of the diene-based rubber. The non-pneumatic tires described in [1] above have improved electrostatic properties.

[0009] [2] The non-pneumatic tire according to [1], further comprising an intervening layer between the connecting member and the conductive rubber layer. The non-pneumatic tire described in [2] above exhibits excellent adhesive strength between the connecting member and the conductive rubber layer.

[0010] [3] The non-pneumatic tire according to [2], wherein the intervening layer is an adhesive layer or an intervening rubber layer. The non-pneumatic tire described in [3] above exhibits excellent adhesive strength between the connecting member and the conductive rubber layer.

[0011] [4] The intervening layer is the adhesive layer, The non-pneumatic tire according to [3], wherein the adhesive layer comprises a urethane-based adhesive or an epoxy-based adhesive. The non-pneumatic tire described in [4] above offers superior adhesive strength between the connecting member and the conductive rubber layer.

[0012] [5] The intervening layer is the adhesive layer, The conductive rubber layer includes a surface treatment layer on the surface that is in contact with the adhesive layer. The non-pneumatic tire according to [3] or [4], wherein the surface treatment layer is a chlorinated layer. The non-pneumatic tire described in [5] above offers even greater adhesive strength between the connecting member and the conductive rubber layer.

[0013] [6] The intervening layer is the intervening rubber layer, The intervening rubber layer includes a surface treatment layer on the surface that comes into contact with the connecting member. The non-pneumatic tire according to [3], wherein the surface treatment layer is a chlorinated layer. The non-pneumatic tire described in [6] above allows the rubber layer and the connecting member to be bonded without the use of adhesive, and further improves the adhesive strength between the connecting member and the conductive rubber layer.

[0014] [7] The surface of the connecting member where the conductive rubber layer is provided has an average length of crystal size in the region up to a depth of 250 μm of 10 μm or less, the non-pneumatic tire according to any one of [1] to [6]. The non-pneumatic tire according to [7] above has further excellent adhesion strength between the connecting member and the conductive rubber layer.

[0015] [8] The conductive rubber layer has a surface resistivity before and after running of 1 × 10 10 Ω or less when the non-pneumatic tire is run for 20,000 km on a durability drum tester, the non-pneumatic tire according to any one of [1] to [7]. The non-pneumatic tire according to [8] above has improved charging properties before and after running.

[0016] [9] A method for manufacturing the non-pneumatic tire according to [5], a step (1A) of performing a surface treatment on at least a part of the surface of the connecting member that is adhered to the conductive rubber layer, a step (2A) of performing a surface treatment on at least a part of the surface of the connecting member that is adhered to the conductive rubber layer so that the ratio [height of the peak derived from the (010) plane / height of the peak derived from the (100) plane] in X-ray diffraction is 1.1 or more, a step (3A) of adhering the surface-treated surface of the conductive rubber layer and the surface-treated surface of the connecting member with an adhesive, a method for manufacturing a non-pneumatic tire including the above. According to the method for manufacturing a non-pneumatic tire according to [9] above, a non-pneumatic tire with improved charging properties and excellent adhesion strength between the connecting member and the conductive rubber layer can be manufactured.

[0017]

[10] A method for manufacturing the non-pneumatic tire according to [6], a step (1B) of performing a surface treatment on at least a part of the surface of the intervening rubber layer, (2B) A step of surface treatment being performed on at least a portion of the surface of the connecting member such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [peak height originating from the (010) plane / peak height originating from the (100) plane] is 1.1 or more, A method for manufacturing a non-pneumatic tire, comprising the step (3B) of providing the surface-treated surface of the intervening rubber layer to the surface-treated surface of the connecting member without using an adhesive. According to the method for manufacturing a non-pneumatic tire described in

[10] above, it is possible to manufacture a non-pneumatic tire that has improved electrostatic properties, can bond the rubber layer and the connecting member without the use of an adhesive, and has excellent adhesive strength between the connecting member and the conductive rubber layer. [Effects of the Invention]

[0018] According to this disclosure, it is possible to provide a non-pneumatic tire with improved electrostatic properties and a method for manufacturing the same. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic diagram showing the configuration of a non-pneumatic tire according to one embodiment of the present disclosure, as viewed from the side of the tire. [Figure 2] This is a cross-sectional view of a connecting member in a non-pneumatic tire according to one embodiment of the present disclosure, cut in the tire width direction. [Figure 3] This is a cross-sectional view of a connecting member in a non-pneumatic tire according to a further embodiment of the present disclosure, cut in the tire width direction. [Figure 4] This is a cross-sectional view of a connecting member in a non-pneumatic tire according to another embodiment of the present disclosure, cut in the tire width direction. [Modes for carrying out the invention]

[0020] The non-pneumatic tire and the method for manufacturing the non-pneumatic tire described herein will be explained in detail below based on embodiments thereof.

[0021] <Definition> The compounds described herein may be derived in part or in whole from fossil resources, from biological resources such as plant resources, or from recycled resources such as used tires. They may also be derived from a mixture of two or more of fossil resources, biological resources, or recycled resources.

[0022] In this specification, "skeletal member" means a member that constitutes the skeleton of a non-pneumatic tire, more specifically, a member that supports the tread member from the inside to the outside of the tire in order to maintain the shape of the tire tread. Skeletal members include, for example, the inner cylinder, outer cylinder, and connecting members (spoke structure) in a non-pneumatic tire (hereinafter, these may be collectively referred to as "connecting members, etc.").

[0023] In this specification, the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane is determined by X-ray diffraction analysis. If no peak originating from the (100) plane appears, the maximum value of the diffraction intensity (CPS) in the diffraction angle (2θ) range of 20 to 25° is taken as the peak height originating from the (100) plane. Furthermore, in this specification, the ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane is determined by performing X-ray diffraction analysis and then using the Pseudo Voigt function as a fitting program to perform peak splitting on the resulting X-ray diffraction chart.

[0024] In this specification, the average length of the crystal size in the region of the connecting member (and inner and outer cylinders) up to a depth of 250 μm is determined by analyzing a thin section taken from the surface of the connecting member (and inner and outer cylinders) with a polarizing microscope, measuring the longest side of 20 crystals in the resulting image, and taking the average of these lengths.

[0025] <Airless tires> The non-pneumatic tire of this embodiment is A non-pneumatic tire comprising: an inner cylinder fitted to the wheel; an outer cylinder surrounding the inner cylinder from the outside in the tire radial direction; a plurality of connecting members arranged between the inner cylinder and the outer cylinder along the tire circumferential direction, connecting the two cylinders together; and a tread member provided on the outer side of the outer cylinder in the tire radial direction, The inner cylinder, the outer cylinder, and the connecting member are made of a resin composition. At least the connecting member has a conductive rubber layer provided so as to connect the inner cylinder and the outer cylinder, The conductive rubber layer comprises a diene-based rubber and carbon black. The carbon black content is characterized by being 50 parts by mass or more per 100 parts by mass of the diene rubber. The connecting members and other structural components of non-pneumatic tires are typically made of resin compositions with low conductivity. As a result, static electricity generated in the vehicle is not released to the ground, causing the tires to become charged. However, the above-mentioned non-pneumatic tire is provided with a conductive rubber layer connected between the inner and outer cylinders, at least on the connecting member. This conductive rubber layer contains a relatively large amount of carbon black and therefore has excellent conductivity, allowing static electricity to be released through this conductive rubber layer. Therefore, the non-pneumatic tire of this embodiment has improved electrostatic properties.

[0026] First, the configuration of the non-pneumatic tire of this embodiment (hereinafter sometimes simply referred to as "tire") will be described with reference to Figure 1. Figure 1 is a schematic diagram showing the configuration of a non-pneumatic tire 1 according to one embodiment of the present disclosure, as viewed from the side of the tire. In the drawings used in the following description, the scale has been appropriately changed to make each component recognizable.

[0027] As shown in Figure 1, the non-pneumatic tire 1 of this embodiment comprises an inner cylinder 2 fitted onto a wheel (not shown), an outer cylinder 3 surrounding the inner cylinder 2 from the outside in the tire radial direction, and multiple elastically deformable connecting members 4 arranged between the inner cylinder 2 and the outer cylinder 3 along the tire circumferential direction, which connect the inner cylinder 2 and the outer cylinder 3 so that they can be displaced relative to each other. A tread member 5 is fitted onto the outer circumferential surface of the outer cylinder 3. This non-pneumatic tire 1 is used on wheelchairs (especially electric wheelchairs), bicycles, motorcycles, golf carts, automobiles, etc. (hereinafter, these are collectively referred to simply as vehicles).

[0028] Here, the inner cylinder 2, outer cylinder 3, and tread member 5 are formed in an annular shape, and their respective central axes are located on a common axis. In this specification, this common axis is referred to as the central axis O, and the direction along the central axis O is referred to as the tire width direction. Furthermore, in a side view from the tire width direction, the direction that circles around the central axis O is referred to as the tire circumferential direction, and the direction perpendicular to this central axis O is referred to as the tire radial direction.

[0029] The inner cylinder 2 is attached to the vehicle's axle (not shown) via a wheel. The wheel and axle can be made of metal materials such as aluminum, aluminum alloy, or steel. The central axes of the inner cylinder 2 and the outer cylinder 3 are coaxial with the central axis O. The inner cylinder 2, the outer cylinder 3, and the connecting member 4 are positioned such that their respective centers in the tire width direction coincide.

[0030] In this embodiment, the inner cylinder 2, outer cylinder 3, and connecting member 4 may be integrally formed from a resin composition. This allows the inner cylinder 2, outer cylinder 3, and connecting member 4 to be molded by injection molding, making them suitable for mass production. The inner cylinder 2, outer cylinder 3, and connecting member 4 may each be formed as separate components.

[0031] The tread member 5 may be formed from, for example, vulcanized rubber obtained by vulcanizing a rubber composition including natural rubber, or from a thermoplastic material. Examples of thermoplastic materials include polyurethane resin, polyolefin resin, polyvinyl chloride resin, and polyamide resin. From the viewpoint of abrasion resistance, it is preferable to form the tread member 5 from vulcanized rubber. In this embodiment, an adhesive layer (not shown) may be provided between the outer cylinder 3 and the tread member 5 to interpose the joining of the outer cylinder 3 and the tread member 5. A commercially available adhesive can be used for the adhesive layer. For example, cyanoacrylate adhesives or epoxy adhesives can be used, and specifically, Aron Alpha EXTRA 2000 (manufactured by Toagosei Co., Ltd.) can be used, but it is not limited to these.

[0032] The connecting member 4 is formed as a curved rectangular plate, with its front and back surfaces facing the tire circumferential direction and its sides facing the tire width direction. The connecting member 4 is made of an elastically deformable material and connects the outer circumferential surface of the inner cylinder 2 and the inner circumferential surface of the outer cylinder 3 in a manner that allows for relative elastic displacement. Multiple connecting members 4 are arranged at equal intervals in the tire circumferential direction. In Figure 1, there are 30 connecting members 4, but the number of connecting members 4 in the non-pneumatic tire 1 of this embodiment is not limited to this.

[0033] Each of the multiple connecting members 4 has an inner portion 4a connected to the inner cylinder 2 and an outer portion 4b connected to the outer cylinder 3. The inner portion 4a and the outer portion 4b are connected to each other at the center of the connecting member 4 in the tire radial direction. When driving, the connecting member 4 elastically deforms under load, absorbing vibrations transmitted from the ground to the vehicle.

[0034] In the non-pneumatic tire 1 according to this embodiment, the inner cylinder 2, outer cylinder 3, and connecting member 4 of the non-pneumatic tire 1 are sometimes collectively referred to as the skeletal member, and it is preferable that the inner cylinder 2, outer cylinder 3, and connecting member 4 are made of a resin composition described later. Furthermore, in the non-pneumatic tire 1 according to this embodiment, different resin compositions may be used for the inner cylinder 2, outer cylinder 3, and connecting member 4 that constitute the skeletal member.

[0035] Although not shown in Figure 1, in the non-pneumatic tire 1 of this embodiment, a conductive rubber layer 6 is provided on at least the connecting member 4 so as to be connected across the inner cylinder 2 and the outer cylinder 3. The conductive rubber layer 6 may be provided on only some of the multiple connecting members 4, or on all of the connecting members 4. The conductive rubber layer 6 may be provided on the surface of the connecting member 4 facing the tire width direction (front or back surface), or on the surface facing the tire circumferential direction (side surface). Furthermore, the conductive rubber layer 6 may be provided to cover the entire surface of the connecting member 4. Furthermore, in the non-pneumatic tire 1 of this embodiment, the conductive rubber layer 6 is provided on at least the connecting member 4, but it may also be provided not only on the connecting member 4 but also on the inner cylinder 2 and / or the outer cylinder 3. That is, the conductive rubber layer 6 may be provided on the connecting member 4 and the inner cylinder 2, on the connecting member 4 and the outer cylinder 3, or on the connecting member 4, the inner cylinder 2 and the outer cylinder 3.

[0036] (Conductive rubber layer) In the non-pneumatic tire 1 of this embodiment, the conductive rubber layer 6 is provided on at least the connecting member 4 so as to be connected across the inner cylinder 2 and the outer cylinder 3. As described above, the conductive rubber layer 6 may also be provided across the inner cylinder 2 and / or the outer cylinder 3 in addition to the connecting member 4. That is, the conductive rubber layer 6 may be continuously provided on the skeletal member.

[0037] The conductive rubber layer 6 contains a diene-based rubber and carbon black. The carbon black provides conductivity to the conductive rubber layer 6. The conductive rubber layer 6 may also contain other components besides the diene-based rubber and carbon black.

[0038] Examples of the diene rubber include natural rubber (NR), synthetic isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), and chloroprene rubber (CR). The diene rubber may be used alone or as a blend of two or more types.

[0039] In the conductive rubber layer 6, the carbon black content is 50 parts by mass or more per 100 parts by mass of diene rubber. When the carbon black content is 50 parts by mass or more per 100 parts by mass of diene rubber, the electrical resistance of the conductive rubber layer 6 becomes sufficiently low, resulting in excellent conductivity. Furthermore, from the viewpoint of excellent conductivity, the carbon black content is preferably 55 parts by mass or more, and more preferably 60 parts by mass or more, per 100 parts by mass of diene rubber. Furthermore, due to the reason of strength reduction, the carbon black content is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, and even more preferably 80 parts by mass or less, per 100 parts by mass of diene rubber. These upper and lower limits can be combined arbitrarily.

[0040] The carbon black mentioned above is not particularly limited and examples include HAF, ISAF, and SAF grade carbon black. These carbon blacks may be used individually or in combination of two or more types.

[0041] The conductive rubber layer 6 may contain other components in addition to the diene-based rubber and carbon black mentioned above. Examples of other components include antioxidants, crosslinking agents, vulcanization accelerators, oils, and zinc oxide. These other components can be used as appropriate, as long as they do not interfere with the conductivity of the conductive rubber layer 6.

[0042] The average thickness of the conductive rubber layer 6 is not limited, but for example, it can be 0.1 mm to 1 mm.

[0043] When the conductive rubber layer 6 was subjected to a 20,000 km run on a non-pneumatic tire 1 in a durability drum tester, the surface resistivity before and after the run was 1 × 10⁻⁶. 10 It is preferable that the resistance is Ω or less. When the non-pneumatic tire 1 is driven for 20,000 km on a durability drum tester, the surface resistivity of the conductive rubber layer 6 before and after driving is 1 × 10⁻⁶. 10 If the resistance is less than Ω, the electrostatic charge before and after travel is improved. Furthermore, the surface resistivity before and after travel is 1 × 10⁻⁶ 0 It may be Ω or higher. When the conductive rubber layer 6 was subjected to a 20,000 km run on a non-pneumatic tire 1 in a durability drum tester, the surface resistivity of the conductive rubber layer 6 before running was 1 × 10⁻⁶. 8 It is more preferable that it be less than or equal to Ω, 1 × 10 7 It is even more preferable that the resistivity is less than or equal to Ω. Furthermore, when the conductive rubber layer 6 is subjected to a 20,000 km run on a non-pneumatic tire 1 in a durability drum tester, the surface resistivity after the run is 1 × 10⁻⁶. 8 It is more preferable that it be less than or equal to Ω, 1 × 10 7 It is even more preferable that it be less than or equal to Ω. The above upper and lower limits can be combined in any way. The surface resistivity of the conductive rubber layer 6 was measured using a tester at room temperature (23°C).

[0044] (intervening layer) As shown in Figure 2, the non-pneumatic tire 1 of this embodiment preferably includes an intervening layer 7 between the connecting member 4 and the conductive rubber layer 6. The intervening layer 7 enhances the adhesive strength between the connecting member 4 and the conductive rubber layer 6. If the conductive rubber layer 6 is provided not only on the connecting member 4 but also extending across the inner cylinder 2 and / or the outer cylinder 3, it is preferable to also include an intervening layer 7 between the inner cylinder 2 and the conductive rubber layer 6, and / or between the outer cylinder 2 and the conductive rubber layer 6. By providing an intervening layer 7 between the connecting member 4 (and the inner cylinder 2 and outer cylinder 3) and the conductive rubber layer 6, the adhesive strength between the connecting member 4 (and the inner cylinder 2 and outer cylinder 3) and the conductive rubber layer 6 can be increased.

[0045] The intervening layer 7 is preferably an adhesive layer 8 or an intervening rubber layer 9. In this case, the adhesive strength between the connecting member 4 (and the inner cylinder 2 and outer cylinder 3) and the conductive rubber layer 6 is excellent. The adhesive layer 8 and the intervening rubber layer 9 will be described later. The average thickness of the intervening layer 7 is not particularly limited, but can be, for example, 0.01 to 0.5 mm.

[0046] [Adhesive layer] In one preferred embodiment, the intervening layer 7 is an adhesive layer 8. The adhesive layer 8 serves to bond the connecting member 4 and the conductive rubber layer 6.

[0047] The adhesive layer 8 is preferably made of a urethane-based adhesive or an epoxy-based adhesive, although this is not limited to the adhesive. The urethane-based adhesive and epoxy-based adhesive are preferably one-component or two-component, and more preferably two-component.

[0048] Examples of one-component urethane adhesives include moisture-curing adhesives containing a urethane prepolymer having an isocyanate group.

[0049] Furthermore, examples of two-component urethane adhesives include adhesives containing a main component containing a polyol and a curing agent containing an isocyanate. Examples of polyols include polyether polyols, polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyolefin polyols, and castor oil-based polyols, among which polyester polyols are preferred. Examples of polyester polyols include those obtained by the reaction of polycarboxylic acids such as terephthalic acid, isophthalic acid, 1,5-naphthalic acid, 2,6-naphthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decamethylenedicarboxylic acid, and dodecamethylenedicarboxylic acid with polyols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and cyclohexanediol, as well as poly-ε-caprolactone polyols obtained by ring-opening polymerization of ε-caprolactone. Examples of isocyanates include 2,2-diphenylmethane diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, liquid modified diphenylmethane diisocyanate, polymeric MDI (methane diisocyanate), tolylene diisocyanate, naphthalene-1,5-diisocyanate, 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate, and hexamethylene diisocyanate.

[0050] Commercially available urethane adhesives can be used. Examples of such urethane adhesives include "UT100B" and "EP171" from Cemedyne Corporation, "560" from 3M Corporation, "NIPPORAN 2304" and "NIPPORAN 3114" from Tosoh Corporation, "DA3146" from Nogawa Chemical Co., Ltd., "TAKENATE XL3052-20" and "TAKERIGHT 4010 / 4000B" from Mitsui Chemicals, Inc., and "7411" and "7542" from LORD Co., Ltd.

[0051] Examples of one-component epoxy adhesives include room-temperature curing or heat-curing adhesives containing a latent curing agent such as ketimine, oxazolidine, or aldimine compounds, and a liquid epoxy resin.

[0052] Furthermore, examples of two-component epoxy adhesives include adhesives containing a main component selected from liquid epoxy resin and a hardening agent. Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, hydroquinone diglycidyl ether, and the like. Furthermore, examples of curing agents include linear aliphatic polyamines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, diethylaminopropylamine, modified aliphatic polyamines, amine adducts, ketoimines, cyclic aliphatic polyamines, N-aminoethylpiperazine, mensendiamine, isophoronediamine, aromatic amines, m-xylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, polyamidoamines, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, polythiols, polymercaptans, polysulfides, and the like.

[0053] Commercially available epoxy adhesives can be used. Examples of such epoxy adhesives include "Metlweld," "Silver chip," and "T-88" from SYSTEM THREE, "ARARALDITE RT30," "ARARALDITE 2013," "ARARALDITE 2014," and "ARARALDITE 2015" from Huntsman, "EAE-30CL," "E-05CL," "U-10FL," and "EA-E00CL" from Henkel, "3500" and "3600" from Alteco, "DP190" from 3M, and "AP209" and "AP400ED" from Toagosei Co., Ltd.

[0054] The adhesive layer 8 is more preferably made of a urethane-based adhesive. When the adhesive layer 8 is made of a urethane-based adhesive, the adhesion between the connecting member 4 (and the inner cylinder 2 and outer cylinder 3) and the conductive rubber layer 6 is superior. In other words, in a more preferred embodiment, the intervening layer 7 is the adhesive layer 8, and the adhesive layer 8 is made of a urethane-based adhesive.

[0055] Furthermore, in one preferred embodiment, as shown in Figure 3, the intervening layer 7 is an adhesive layer 8, and the conductive rubber layer 6 includes a surface treatment layer 10 on the surface that contacts the connecting member 4, wherein the surface treatment layer 10 is a chlorinated layer. In this case, the adhesive strength between the connecting member 4 and the conductive rubber layer 6 is superior due to the surface treatment layer 10. Also, when the conductive rubber layer 6 is provided not only on the connecting member 4 but also extending over the inner cylinder 2 and / or outer cylinder 3, it is preferable that the intervening layer 7 is an adhesive layer 8, and the conductive rubber layer 6 includes a surface treatment layer 10 on the surface that contacts the connecting member 4 and the inner cylinder 2 and / or outer cylinder 3, wherein the surface treatment layer 10 is a chlorinated layer. The surface treatment layer 10 will be described later.

[0056] [Intervening rubber layer] In another preferred embodiment, the intervening layer 7 is an intervening rubber layer 9. This intervening rubber layer 9 is a rubber layer having a different composition from the conductive rubber layer 6 described above. In particular, it is preferable that the intervening rubber layer 9 has a lower carbon black content than the conductive rubber layer 6. The conductive rubber layer 6 needs to have excellent conductivity and therefore contains a relatively large amount of carbon black. When rubber has a relatively high carbon black content, its adhesion to the resin composition member becomes low. Therefore, by providing an intervening rubber layer 9 with relatively high adhesion to the resin composition connecting member 4 (and inner cylinder 2 and outer cylinder 3) between the conductive rubber layer 6 and the connecting member 4 (and inner cylinder 2 and outer cylinder 3), the adhesive strength between the conductive rubber layer 6 and the connecting member 4 (and inner cylinder 2 and outer cylinder 3) can be increased. When the intervening layer 7 is an intervening rubber layer 9, there is also the advantage that the conductive rubber layer 6 and the connecting member 4 (and inner cylinder 2 and outer cylinder 3) can be bonded together without the need for an adhesive.

[0057] Various rubber compositions containing at least a rubber component can be used for the intervening rubber layer 9, and it is preferable to form the intervening rubber layer 9 from vulcanized rubber obtained by vulcanizing the rubber composition. The rubber composition can be produced, for example, by mixing a rubber component consisting of natural rubber or synthetic rubber (butadiene rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, etc.) with fillers such as carbon black and silica, antioxidants, crosslinking agents such as stearic acid, sulfur, and peroxides, crosslinking accelerators, etc., and then kneading, heating, extruding, etc.

[0058] Examples of the aforementioned anti-aging agents include N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMDQ), 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (AW), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine (77PD), N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, and N,N'-dicyclohexyl-p-phenylenediamine (CCPD). The content of the aforementioned antioxidant is not particularly limited, but is preferably in the range of 0.1 to 15 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the rubber component.

[0059] Examples of softeners include softeners derived from fossil resources (particularly petroleum-derived) and softeners derived from biological resources (particularly plant-derived). Examples of softeners derived from fossil resources include aromatic oils, paraffinic oils, and naphthenic oils. Examples of softeners derived from biological resources include palm oil, castor oil, cottonseed oil, and soybean oil. A mixture of naphthenic oil and asphalt may also be used as a softener. The content of the softening agent is not particularly limited, but is preferably in the range of 1 to 150 parts by mass, and more preferably 5 to 100 parts by mass, per 100 parts by mass of rubber component.

[0060] Furthermore, the rubber components in the intervening rubber layer 9 may include fillers such as carbon black and silica, antioxidants, crosslinking agents such as stearic acid, sulfur, and peroxides, and crosslinking accelerators. The content of these components can be set as appropriate. Furthermore, from the viewpoint of adhesion to skeletal members such as the connecting member 4, the carbon black content is preferably 20 to 50 parts by mass, and more preferably 20 to 45 parts by mass, per 100 parts by mass of rubber component. If the carbon black content in the intervening rubber layer 9 is within the above range, there will be no problem with the adhesive strength to the connecting member 4, etc.

[0061] Preferably, as shown in Figure 4, the intervening layer 7 is the intervening rubber layer 9, and the intervening rubber layer 9 includes a surface treatment layer 10 on the surface that contacts the connecting member 4, and the surface treatment layer 10 is a chlorinated layer. By including the surface treatment layer 10 in the intervening rubber layer 9, the adhesive strength between the connecting member 4 and the intervening rubber layer 9 can be further increased, and consequently, the adhesive strength between the connecting member 4 and the conductive rubber layer 6 can be further increased. Furthermore, if the conductive rubber layer 6 is provided not only on the connecting member 4 but also extending across the inner cylinder 2 and / or outer cylinder 3, it is preferable that the intervening layer 7 is the intervening rubber layer 9, and the intervening rubber layer 9 includes a surface treatment layer 10 on the surface that contacts the connecting member 4 and the inner cylinder 2 and / or outer cylinder 3, and the surface treatment layer 10 is a chlorinated layer. The surface treatment layer 10 will be described later.

[0062] [Surface treatment layer] The surface treatment layer 10 is a layer that has been surface-treated to improve the adhesive strength between the connecting member 4, etc., and the conductive rubber layer 6 or intervening rubber layer 9. The interface between the surface treatment layer 10 and the other parts of the conductive rubber layer 6 or intervening rubber layer 9 can be determined by identifying the traces of the applied surface treatment, and the average distance from the surface of the conductive rubber layer 6 or intervening rubber layer 9 (i.e., the surface of the conductive rubber layer 6 and intervening rubber layer 10 that is bonded to the connecting member 4, etc.) to the traces of the surface treatment becomes the average thickness of the surface treatment layer. The average thickness of the surface treatment layer 10 is not particularly limited, but is preferably 10 μm or less.

[0063] As the surface treatment applied to the conductive rubber layer 6 or interlayer rubber layer 9, chlorination treatment is preferred, that is, the surface treatment layer 10 of the conductive rubber layer 6 or interlayer rubber layer 9 is preferably a chlorinated layer. In this case, the traces of the surface treatment become chlorine in the conductive rubber layer 6 or interlayer rubber layer 9, and the average distance from the surface of the conductive rubber layer 6 or interlayer rubber layer 9 to the deepest chlorine in the conductive rubber layer 6 or interlayer rubber layer 9 becomes the average thickness of the surface treatment layer 10. When the surface treatment layer 10 of the conductive rubber layer 6 or interlayer rubber layer 9 is a chlorinated layer, the adhesive strength between the conductive rubber layer 6 or interlayer rubber layer 9 and the connecting member 4 (and, in some cases, the outer cylinder 2 and inner cylinder 3) made of the resin composition is further improved.

[0064] As the chemicals (surface treatment agents) used in the chlorination treatment, hypochlorous acid aqueous solution and chlorinated cyanuric acid are preferred. Surface treatment with these chemicals further improves the adhesive strength between the conductive rubber layer 6 or intervening rubber layer 9 and the connecting member 4.

[0065] Furthermore, when the surface of the conductive rubber layer 6 or the intervening rubber layer 9 is subjected to chlorination treatment, it is believed that an oxidation (chloromination) reaction of the olefin portion will occur in at least a portion of the surface of the conductive rubber layer 6 or the intervening rubber layer 9. Here, when a hypochlorous acid aqueous solution is used for the chlorination treatment, it is believed that in the oxidation (chloromination) reaction, chlorine groups and hydroxyl groups are introduced to the carbon atoms that formed C=C double bonds in the rubber molecules present on the surface of the conductive rubber layer 6 or the intervening rubber layer 9 through the mechanism shown below. It is believed that the introduction of these groups increases the polarity of the surface of the conductive rubber layer 6 or the intervening rubber layer 9, thereby increasing its wettability and contributing to strong adhesion. [ka]

[0066] The pH value of the hypochlorous acid aqueous solution used as the surface treatment agent is preferably between 2 and 7. A pH value of 2 or higher reduces the release of chlorine gas and makes it easier to maintain the hypochlorous acid aqueous solution within the desired effective chlorine concentration range. Furthermore, a pH value of 7 or lower makes it easier to further improve the adhesive strength between the conductive rubber layer 6 or intervening rubber layer 9 and the connecting member 4, etc. From the viewpoint of stability, a pH value of 4 or higher is more preferable for the hypochlorous acid aqueous solution.

[0067] The effective chlorine concentration of the hypochlorous acid aqueous solution is preferably 100 ppm or more and 13,000 ppm or less. When the effective chlorine concentration is 100 ppm or more and 13,000 ppm or less, the adhesive strength between the conductive rubber layer 6 or intervening rubber layer 9 and the connecting member 4 is more easily improved. From a similar viewpoint, the effective chlorine concentration of the hypochlorous acid aqueous solution is more preferably 200 ppm or more, even more preferably 300 ppm or more, even more preferably 8,000 ppm or less, even more preferably 4,000 ppm or less, even more preferably 1,000 ppm or less, and particularly preferably 500 ppm or less.

[0068] The effective chlorine concentration of the hypochlorous acid aqueous solution can be adjusted, for example, by the dilution ratio when obtaining an aqueous solution by dissolving a hypochlorite salt such as sodium hypochlorite in water. Furthermore, the pH value of a hypochlorous acid solution can be lowered, for example, by adding hydrochloric acid, and can be adjusted by changing the ratio of hydrochloric acid added. The pH value of an aqueous solution obtained by dissolving sodium hypochlorite in water is approximately 9-10. Also, if a large amount of chlorine is added to a hypochlorous acid solution rapidly, chlorine gas will be generated, and the effective chlorine concentration will decrease accordingly, so care should be taken during adjustment.

[0069] The chlorinated cyanuric acid is not particularly limited, and examples include dichloroisocyanuric acid and trichloroisocyanuric acid. The chlorinated cyanuric acid may be used alone or in combination of two or more types. Among these, trichloroisocyanuric acid is preferred as the chlorinated cyanuric acid from the viewpoint of further improving the adhesive strength between the conductive rubber layer 6 or intervening rubber layer 9 and the connecting member 4, etc.

[0070] The chlorinated cyanuric acid is preferably used as an aqueous solution. The concentration of chlorinated cyanuric acid in the aqueous solution is not particularly limited, but from the viewpoint of adhesive strength between the conductive rubber layer 6 or intervening rubber layer 9 and the connecting member 4, etc., and workability, it is preferably 0.5% by mass or more and 10% by mass or less.

[0071] (Skeleton members) In the non-pneumatic tire 1 of this embodiment, the inner cylinder 2, outer cylinder 3, and connecting member 4 are made of a resin composition. These inner cylinder 2, outer cylinder 3, and connecting member 4 are sometimes collectively referred to as the skeletal members. In this specification, the connecting member 4 is sometimes described as a representative of the skeletal members, but a similar description can be applied to the inner cylinder 2 and outer cylinder 3. The following describes the resin compositions that constitute the skeletal members, such as the connecting member 4.

[0072] In the non-pneumatic tire 1 of this embodiment, the resin composition used for the inner cylinder 2, outer cylinder 3, and connecting member 4 preferably has a flexural modulus of elasticity at -20°C in accordance with ISO 178 of 247 MPa or less, more preferably 234 MPa or less, and even more preferably 170 MPa or less, and is usually 80 MPa or more, preferably 90 MPa or more. If the flexural modulus of elasticity at -20°C exceeds 247 MPa, the inner cylinder 2, outer cylinder 3, and connecting member 4 become too hard, causing vibrations transmitted from the tire to become more intense and worsening the ride comfort. Furthermore, the inner cylinder 2, outer cylinder 3, and connecting member 4 (skeletal members) become too hard and brittle, thus worsening their durability. If the flexural modulus of elasticity at -20°C is 90 MPa or more, a good balance of ride comfort and durability in low-temperature environments is achieved.

[0073] In the non-pneumatic tire 1 of this embodiment, the resin composition used for the inner cylinder 2, outer cylinder 3, and connecting member 4 preferably has a flexural modulus of elasticity at 60°C of 32 MPa or higher, more preferably 34 MPa or higher, even more preferably 36 MPa or higher, and usually 90 MPa or lower, preferably 70 MPa or lower, in accordance with ISO 178. If the flexural modulus of elasticity at 60°C is less than 32 MPa, the inner cylinder 2, outer cylinder 3, and connecting member 4 become too soft, which may result in a deterioration of ride comfort and reduced durability when a vehicle equipped with the non-pneumatic tire 1 is driven. Furthermore, if the flexural modulus of elasticity at 60°C is 70 MPa or lower, a good balance of ride comfort and durability in high-temperature environments is achieved.

[0074] The flexural modulus at 0°C of the resin composition used in the inner cylinder 2, outer cylinder 3, and connecting member 4 is usually 61 MPa or higher, preferably 70 MPa or higher, and usually 159 MPa or lower, preferably 130 MPa or lower. If the flexural modulus at 0°C is 70 MPa or higher, the ride comfort in low-temperature environments is further improved, and if the flexural modulus at 0°C is 130 MPa or lower, the ride comfort and durability in low-temperature environments are improved in a well-balanced manner.

[0075] The flexural modulus at 23°C of the resin composition used for the inner cylinder 2, outer cylinder 3, and connecting member 4 is usually 53 MPa or higher, preferably 60 MPa or higher, and usually 127 MPa or lower, preferably 115 MPa or lower. If the flexural modulus at 23°C is 60 MPa or higher, the ride comfort at room temperature is further improved, and if the flexural modulus at 23°C is 115 MPa or lower, the ride comfort and durability at room temperature are improved in a well-balanced manner.

[0076] The flexural modulus at 40°C of the resin composition used in the inner cylinder 2, outer cylinder 3, and connecting member 4 is usually 40 MPa or higher, preferably 44 MPa or higher, and usually 96 MPa or lower, preferably 84 MPa or lower. If the flexural modulus at 40°C is 44 MPa or higher, the ride comfort in high-temperature environments is further improved, and if the flexural modulus at 40°C is 84 MPa or lower, the ride comfort and durability in high-temperature environments are improved in a well-balanced manner.

[0077] The resin component of the resin composition used for the inner cylinder 2, outer cylinder 3, and connecting member 4 is preferably a thermoplastic elastomer or a thermoplastic resin, with a thermoplastic elastomer being more preferred. In addition to the resin component, various additives can be added to the resin composition. The resin component content in the resin composition is preferably 80% by mass or more, and more preferably 90% by mass or more. Here, thermoplastic elastomers and thermoplastic resins are polymer compounds that soften and flow as the temperature rises, and become relatively hard and strong when cooled. In this specification, polymer compounds that soften and flow as the temperature rises, become relatively hard and strong when cooled, and have rubber-like elasticity are referred to as thermoplastic elastomers, while polymer compounds that soften and flow as the temperature rises, become relatively hard and strong when cooled, and do not have rubber-like elasticity are referred to as thermoplastic resins. Furthermore, "thermoplastic elastomer" refers to a thermoplastic resin material having hard segments and soft segments in its molecule. More specifically, it refers to a thermoplastic resin material consisting of an elastic polymer compound, comprising a copolymer having a crystalline, high-melting-point hard segment and an amorphous, low-glass transition-temperature soft segment. Note that the thermoplastic elastomer in this invention does not include vulcanized rubbers such as natural rubber or synthetic rubber.

[0078] Examples of the aforementioned thermoplastic elastomers include polyester-based thermoplastic elastomers (TPC), polyamide-based thermoplastic elastomers (TPA), polyolefin-based thermoplastic elastomers (TPO), and polystyrene-based thermoplastic elastomers (TPS). Among these, polyester-based thermoplastic elastomers (TPC) are preferred from the viewpoint of durability and cost. The aforementioned polyester thermoplastic elastomer (TPC) is an elastic polymer compound, and refers to a thermoplastic resin material comprising a copolymer having a crystalline polymer constituting a hard segment with a high melting point and an amorphous polymer constituting a soft segment with a low glass transition temperature, wherein the main chain of the polymer constituting the hard segment has an ester bond.

[0079] Aromatic polyesters can be used as the crystalline polyester that forms the hard segments of the polyester-based thermoplastic elastomer (TPC). Aromatic polyesters can be formed, for example, from aromatic dicarboxylic acids or their ester-forming derivatives and aliphatic diols. Examples of aromatic polyesters that form hard segments include polyethylene terephthalate, polybutylene terephthalate, polystyrene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, with polybutylene terephthalate being preferred. One suitable aromatic polyester for forming the hard segment is polybutylene terephthalate derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol. Furthermore, a dicarboxylic acid component such as isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sulfoisophthalic acid, or ester-forming derivatives thereof, and ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol The polyester may be derived from diol components such as 1,4-cyclohexanedimethanol, tricyclodecanedimethylol, xylylene glycol, bis(p-hydroxy)diphenyl, bis(p-hydroxyphenyl)propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4-(2-hydroxy)phenyl]sulfone, 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 4,4'-dihydroxy-p-terphenyl, or 4,4'-dihydroxy-p-quarterphenyl, or a copolymer polyester obtained by using two or more of these dicarboxylic acid and diol components in combination.

[0080] Examples of polymers that form the soft segments of the polyester-based thermoplastic elastomer (TPC) include polymers selected from aliphatic polyethers and aliphatic polyesters. Examples of the aliphatic polyether include poly(ethylene oxide) glycol, poly(propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide addition polymers of poly(propylene oxide) glycol, copolymers of ethylene oxide and tetrahydrofuran, and the like. Examples of the aliphatic polyester include poly(ε-caprolactone), polyenanthractone, polycapryloractone, polybutylene adipate, and polyethylene adipate. Among these aliphatic polyethers and aliphatic polyesters, poly(tetramethylene oxide) glycol, ethylene oxide addition polymers of poly(propylene oxide) glycol, poly(ε-caprolactone), polybutylene adipate, polyethylene adipate, etc. are preferred from the viewpoint of the elastic properties of the resulting copolymer.

[0081] The polyester-based thermoplastic elastomer can be synthesized by copolymerizing a polymer that forms a hard segment and a polymer that forms a soft segment using a known method. Alternatively, commercially available polyester-based thermoplastic elastomers can be used, such as the "Perprene" series from Toyobo Co., Ltd. (P30B, P40B, P40H, P-46D01, P55B, P70B, P90B, P120B, P150B, P280B, P450B, P150M, S1001, S2001, S5001, S6001, S9001, etc.) and the "Hytrel" series from Toray DuPont (e.g., 3046, 5557, 5577, 5577R-07, 6347, 4047, 4767, 4767N, 4777, etc.).

[0082] The polyamide-based thermoplastic elastomer (TPA) is an elastic polymer compound, and is a thermoplastic resin material comprising a copolymer having a crystalline, high-melting-point hard segment and an amorphous, low-glass transition-temperature soft segment, wherein the main chain of the polymer constituting the hard segment has an amide bond (-CONH-). Examples of the polyamide-based thermoplastic elastomer include materials in which at least the polyamide constitutes a crystalline, high-melting-point hard segment, and other polymers (e.g., polyester, polyether, etc.) constitute an amorphous, low-glass transition-temperature soft segment.

[0083] The crystalline polyamides constituting the hard segment of the polyamide-based thermoplastic elastomer (TPA) include polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6,6), and polyhex Examples include aliphatic polyamides such as methylene sebaamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), and polydecamethylene adipamide (nylon-10,8), and crystalline aromatic polyamides obtained by polycondensation reactions of aromatic diamines such as metaxylenediamine and paraxylenediamine with dicarboxylic acids or derivatives thereof, such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid. Among these, nylon-6, nylon-6,6, and nylon-12 are preferred, with nylon-12 being more preferred.

[0084] Examples of polymers that constitute the soft segment of the polyamide-based thermoplastic elastomer (TPA) include polymers selected from polymethylene and aliphatic polyethers. Examples of the aliphatic polyether include poly(ethylene oxide) glycol, poly(propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide addition polymers of poly(propylene oxide) glycol, copolymers of ethylene oxide and tetrahydrofuran, and the like.

[0085] The polyamide-based thermoplastic elastomer can be synthesized by copolymerizing the polymer forming the hard segment and the polymer forming the soft segment using a known method. Alternatively, commercially available polyamide-based thermoplastic elastomers can be used, such as the "UBESTA XPA" series from Ube Industries (e.g., XPA9063X1, XPA9055X1, XPA9048X2, XPA9048X1, XPA9040X1, XPA9040X2, XPA9044, XPA9048, XPA9055, etc.) and the "Vestamid" series from Daicel Eponic (e.g., E40-S3, E47-S1, E47-S3, E55-S1, E55-S3, EX9200, E50-R2).

[0086] The aforementioned polyolefin-based thermoplastic elastomer (TPO) is an elastic polymer compound, and refers to a thermoplastic resin material comprising a copolymer having a crystalline, high-melting-point hard segment and an amorphous, low-glass transition-temperature soft segment, wherein the polymer constituting the hard segment is a polyolefin such as polypropylene or polyethylene. Examples of the polyolefin-based thermoplastic elastomer include materials in which at least the polyolefin constitutes a hard segment that is crystalline and has a high melting point, and the polyolefin and other olefins constitute a soft segment that is amorphous and has a low glass transition point.

[0087] Examples of polyolefins that form the hard segments of the polyolefin-based thermoplastic elastomer include polypropylene, isotactic polypropylene, polyethylene, and poly-1-butene. Examples of polymers constituting the soft segment of the polyolefin-based thermoplastic elastomer include ethylene-propylene copolymer, propylene-1-hexene copolymer, propylene-4-methyl-1-pentene copolymer, propylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-pentene copolymer, ethylene-1-butene copolymer, 1-butene-1-hexene copolymer, and 1-butene-4-methyl-pentene.

[0088] The polyolefin-based thermoplastic elastomer can be synthesized by copolymerizing the polymer constituting the hard segment and the polymer constituting the soft segment using a known method. Furthermore, commercially available polyolefin-based thermoplastic elastomers can be used, such as Prime TPO® from Prime Polymer, and Tuffmer® and Notio® from Mitsui Chemicals.

[0089] The polystyrene-based thermoplastic elastomer (TPS) refers to an elastic polymer compound, a thermoplastic resin material comprising a copolymer having a polymer constituting a hard segment and a polymer constituting an amorphous soft segment with a low glass transition temperature, wherein the polymer constituting the hard segment is polystyrene or a polystyrene derivative. The polystyrene-based thermoplastic elastomer is not particularly limited, but examples include copolymers in which polystyrene constitutes a hard segment and an amorphous polymer constitutes a soft segment with a low glass transition temperature (e.g., polyethylene, polybutadiene, polyisoprene, hydrogenated polybutadiene, hydrogenated polyisoprene, poly(2,3-dimethyl-butadiene), etc.).

[0090] The polystyrene-based thermoplastic elastomer can be synthesized by copolymerizing the polymer constituting the hard segment and the polymer constituting the soft segment by known methods such as block copolymerization. Furthermore, commercially available polystyrene-based thermoplastic elastomers can be used, such as Toughprene® and Toughtec® manufactured by Asahi Kasei Corporation, or Septon® manufactured by Kuraray Co., Ltd.

[0091] Examples of the thermoplastic resin include polyester resin, polyamide resin, polyolefin resin, and polystyrene resin. Among these, polyester resin is preferred from the viewpoint of durability and cost.

[0092] The polyester resin is a resin having ester bonds in its main chain. While the polyester resin is not particularly limited, crystalline polyester is preferred. Aromatic polyesters can be used as the crystalline polyester. Aromatic polyesters can be formed, for example, from an aromatic dicarboxylic acid or its ester-forming derivative and an aliphatic diol. Examples of the aromatic polyester include polyethylene terephthalate, polybutylene terephthalate, polystyrene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, with polybutylene terephthalate being preferred.

[0093] One example of the aromatic polyester is polybutylene terephthalate derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol. Furthermore, a dicarboxylic acid component such as isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sulfoisophthalic acid, or ester-forming derivatives thereof, and a diol with a molecular weight of 300 or less {for example, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol, decamethylene glycol, and other aliphatic diols}. The polyester may be derived from alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecanedimethylol, xylylene glycol, bis(p-hydroxy)diphenyl, bis(p-hydroxyphenyl)propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4-(2-hydroxy)phenyl]sulfone, 1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane, 4,4'-dihydroxy-p-terphenyl, 4,4'-dihydroxy-p-quarterphenyl, or other aromatic diols, or copolymerized polyesters using two or more of these dicarboxylic acid and diol components in combination. It is also possible to copolymerize polyfunctional carboxylic acid components with three or more functions, polyfunctional oxyacid components, and polyfunctional hydroxy components in a range of 5 mol% or less.

[0094] Commercially available polyester resins can also be used, such as the "DuraNex" series from Polyplastics Corporation (e.g., 2000, 2002, etc.), the NovaDuran series from Mitsubishi Engineering Plastics Corporation (e.g., 5010R5, 5010R3-2, etc.), the "Toraycon" series from Toray Industries, Inc. (e.g., 1401X06, 1401X31, 1401X70, etc.), and the "Planac" series from Toyobo Co., Ltd. (e.g., BT-1000).

[0095] The polyamide resin is a resin having an amide bond (-NHCO-) ​​in its main chain. Examples of the polyamide resin include polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6,6), and polyhexamethylene sevacamide (nylon-6,1 Examples include aliphatic polyamides such as polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), and polydecamethylene adipamide (nylon-10,8), and crystalline aromatic polyamides obtained by polycondensation reactions of aromatic diamines such as metaxylenediamine and paraxylenediamine with dicarboxylic acids or derivatives thereof, such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid. Among these, nylon-6, nylon-6,6, and nylon-12 are preferred, with nylon-12 being more preferred.

[0096] As the polyamide resin, commercially available products can be used, for example, UBESTA manufactured by Ube Industries (e.g., 3014U, 3020U, etc.) and VESTAMID manufactured by Daicel Evonix (e.g., L1600, L1700, etc.).

[0097] The polyolefin resin has a main chain of olefin polymers such as ethylene, propylene, and 1-butene. Examples of the polyolefin resin include polyethylene, polypropylene, polybutene, cycloolefin resins, and copolymers of these resins. Among these, polyethylene, polypropylene, and ethylene-propylene copolymers are preferred, and polypropylene and ethylene-propylene copolymers are more preferred.

[0098] As the aforementioned polyolefin resin, commercially available products can be used, for example, Prime PP (registered trademark) manufactured by Prime Polymer Co., Ltd., and Novatec PP (registered trademark) and Wintec (registered trademark) manufactured by Nippon Polypropylene Co., Ltd.

[0099] The polystyrene resin is a polymer of styrene. Commercially available polystyrene resins can be used, such as Zarec® manufactured by Idemitsu Kosan Co., Ltd., Toyo Styrene® manufactured by Toyo Styrene Co., Ltd., and Sebian manufactured by Daicel Polymer Co., Ltd.

[0100] In the non-pneumatic tire 1 of this embodiment, it is preferable that the resin composition contains a thermoplastic elastomer having hard segments and soft segments in its molecule. A non-pneumatic tire using a resin composition containing a thermoplastic elastomer having hard segments and soft segments in its molecule as a skeletal member exhibits improved ride comfort over a wide temperature range, as well as improved durability.

[0101] Here, it is preferable that the thermoplastic elastomer is a polyester-based thermoplastic elastomer. Non-pneumatic tires using a resin composition containing a polyester-based thermoplastic elastomer as a skeletal member have improved ride comfort over a wide temperature range and also improved durability.

[0102] Furthermore, it is even more preferable that the hard segment of the polyester thermoplastic elastomer is polybutylene terephthalate. A resin composition containing a polyester thermoplastic elastomer in which the hard segment is polybutylene terephthalate has high strength, and a non-pneumatic tire using such a resin composition as a skeletal member has low deflection and particularly good ride comfort and durability.

[0103] The resin composition used for the skeletal member may contain additives in addition to the resin components such as the thermoplastic elastomer and thermoplastic resin mentioned above. Examples of additives to be added to the resin composition include weather-resistant anti-aging agents, heat-resistant anti-aging agents, moisture-resistant heat additives, antistatic agents, lubricants, crystal nucleating agents, tackifiers, anti-fogging agents, mold release agents, plasticizers, fillers, pigments, dyes, fragrances, and flame retardants. Among these, weather-resistant anti-aging agents, heat-resistant anti-aging agents, and moisture-resistant heat additives are preferred, and weather-resistant anti-aging agents and heat-resistant anti-aging agents are even more preferred. By adding weather-resistant anti-aging agents and heat-resistant anti-aging agents to the resin composition, the stability of the resin composition is improved, and non-pneumatic tires using such a resin composition as a skeletal member can maintain the desired properties over a long period of time. The total content of these additives is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the resin component.

[0104] The weather-resistant anti-aging agent is an additive that improves the weather resistance of the resin composition, and benzotriazole compounds and amine compounds (hindered amine compounds) are preferred as the weather-resistant anti-aging agent. Examples of the benzotriazole compounds include 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole, benzenepropanoic acid and ester compounds of 3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy(C7-9 side chain and linear alkyl), octyl 3-[3-tert-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazole-2-yl)phenyl]propionate and 2-ethylhexyl-3-[3-tert- A mixture of butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol, methyl-3-(3-(2H-benzotriazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate / Reaction products of polyethylene glycol 300: 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2H-benzotriazol-2-yl)-4-6-bis(1-methyl-1-phenylethyl)phenol, 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-butyl) Examples include tramethylbutylphenol, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol], 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol, 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole, and 2,2'-methylenebis[6-(benzotriazol-2-yl)-4-tert-octylphenol]. Examples of the amine compounds include bis(1,2,2,6,6-pentamethyl-4-piperidinyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, a mixture of bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, and bis(2,2,6,6-tetramethyl-4-piperidyl) ) Sebacate, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-N,N'-diformylhexamethylenediamine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], tetrakis(1,2,2,6,6 -Pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, reaction product of 1,2,2,6,6-pentamethyl-4-piperidiol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol, 2,2,6,6-Te Examples include reaction products of tramethyl-4-piperidiol and β,β,β',β'-tetramethyl-2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diethanol, bis(1-undecanoxy-2,2,6,6-tetramethylpiperidine-4-yl) carbonate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 2,2,6,6-tetramethyl-4-piperidyl methacrylate. By adding a weather-resistant anti-aging agent to the resin composition, the weather resistance of the resin composition is improved, and non-pneumatic tires using such a resin composition as a skeletal component can maintain the desired properties over a long period of time. The amount of weather-resistant anti-aging agent added is preferably in the range of 1 to 5 parts by mass per 100 parts by mass of the resin component of the resin composition.

[0105] The aforementioned heat-resistant anti-aging agent is an additive that has the effect of improving the heat resistance of the resin composition, and a phenolic compound (hindered phenolic compound) is preferred as the heat-resistant anti-aging agent. Examples of the phenolic compound include 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, 2,4-di-tert-butyl-6-methylphenol, 1,6-hexanediol-bis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(3, 5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis-[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5] Undecane, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 2,2'-butylidenebis(4,6-di-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenol acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di Examples include -tert-pentylphenyl acrylate, 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2-tert-butyl-4-methylphenol, 2,4-di-tert-butylphenol, 2,4-di-tert-pentylphenol, 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), bis-[3,3-bis-(4'-hydroxy-3'-tert-butylphenyl)-butanoic acid]-glycol ester, and N,N'-hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide]. By adding a heat-resistant anti-aging agent to the resin composition, the heat resistance of the resin composition is improved, and non-pneumatic tires using such a resin composition as a skeletal component can maintain the desired properties over a long period of time. The amount of heat-resistant anti-aging agent added is preferably in the range of 1 to 5 parts by mass per 100 parts by mass of the resin component of the resin composition.

[0106] The aforementioned moisture-resistant heat additive is an additive that improves the moisture-resistant heat properties of the resin composition. Preferably, the moisture-resistant heat additive is a carbodiimide compound or an epoxy compound, with epoxy compounds being more preferred. Specifically, the carbodiimide compound can be any compound having one or more carbodiimide groups in its molecule. Examples include monofunctional carbodiimide compounds such as N,N'-diisopropylcarbodiimide, N,N'-di(o-toluyl)carbodiimide, N,N'-dicyclohexylcarbodiimide, and N,N'-bis(2,6-diisopropylphenyl)carbodiimide; difunctional carbodiimide compounds such as p-phenylene-bis(2,6-xylylcarbodiimide), p-phenylene-bis(t-butylcarbodiimide), p-phenylene-bis(mesitylcarbodiimide), tetramethylene-bis(t-butylcarbodiimide), and cyclohexane-1,4-bis(methylene-t-butylcarbodiimide); and polyfunctional carbodiimide compounds such as condensates of isocyanate monomers. Among these, polyfunctional carbodiimide compounds are preferred. Here, a polyfunctional carbodiimide compound refers to a compound having two or more carbodiimide groups. Examples of such polyfunctional carbodiimide compounds include those commonly known by trade names such as Carbodilite LA-1 (manufactured by Nisshinbo Co., Ltd.), Carbodilite HMV-8CA (manufactured by Nisshinbo Co., Ltd.), Carbodilite HMV-15CA (manufactured by Nisshinbo Co., Ltd.), Elastostab H01 (manufactured by Nisshinbo Co., Ltd.), and Stabaxol P (manufactured by Rhein Chemie). One or more of these carbodiimide compounds can be used. Furthermore, as the epoxy compound, specifically, are epoxidized soybean oil, epoxidized linseed oil, phenyl glycidyl ether, allyl glycidyl ether, tert-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-6'-methylcyclohexyl carboxylate, 2,3-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate, 4-(3,4-epoxy Xy-5-methylcyclohexyl)butyl-3',4'-epoxycyclohexyl carboxylate, 3,4-epoxycyclohexyl ethylene oxide, cyclohexylmethyl-3,4-epoxycyclohexyl carboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6'-methylsilohexyl carboxylate, bisphenol A diglycidyl ether, tetrabromobisphenol A glycidyl ether, diglycidyl ester of phthalate, diglycidyl ester of hexahydrophthalate, bis-epoxydicyclopentadie Nyl ether, bis-epoxyethylene glycol, bis-epoxycyclohexyl adipate, butadiene diepoxide, tetraphenylethylene epoxide, octyl epoxytalate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5-dimethyl-1,2-epoxycyclohexane, 3-methyl-5-tert-butyl-1,2-epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate, n-butyl-2,2-dimethyl-3,4-epoxycyclo Hexyl carboxylate, cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate, n-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexyl carboxylate, octadecyl-3,4-epoxycyclohexyl carboxylate, 2-ethylhexyl-3',4'-epoxycyclohexyl carboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexyl carboxylate, 4,5-epoxy tetrahydrophthalic anhydride, 3-tert-butyl-4,Examples include 5-epoxy tetrahydrophthalic anhydride, diethyl-4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate, and di-n-butyl-3-tert-butyl-4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate. One or more of these epoxy compounds can be used. By adding a moisture-resistant heat additive to the resin composition, the moisture-resistant heat resistance of the resin composition is improved, and non-pneumatic tires using such a resin composition as a skeletal member can maintain the desired properties over a long period of time. The amount of moisture-resistant heat additive added is preferably in the range of 1 to 15 parts by mass per 100 parts by mass of the resin component of the resin composition.

[0107] The flexural modulus of the resin composition used in the aforementioned skeletal member at each temperature can be adjusted to a desired range by adjusting the type and blending ratio of the resin components used, and the type and amount of additives added. For example, when using a thermoplastic elastomer having hard segments and soft segments in its molecule as the resin component of the resin composition, selecting one with a high proportion of hard segments in the molecule can increase the flexural modulus of the resin composition at each temperature, while selecting one with a high proportion of soft segments in the molecule can decrease the flexural modulus of the resin composition at each temperature. Furthermore, the method for preparing the resin composition is not particularly limited. Additives may be added after mixing the resin components, or the resin components and additives may be mixed at the same time. Multiple resin components with additives already added may be mixed, or resin components with additives added may be mixed with resin components without additives. The aforementioned resin composition can be processed into skeletal members of a desired shape using various molding methods. Injection molding is preferred as the molding method.

[0108] In the non-pneumatic tire 1 of this embodiment, the surface of the connecting member 4 on which the conductive rubber layer 6 is provided preferably has a ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [(010) plane height / (100) plane height] of 1.1 or more, and more preferably 1.3 or more. If the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane is 1.1 or more, the crystallinity of the surface of the connecting member 4 on which the conductive rubber layer 6 is provided is sufficiently low, and the adhesive strength between the connecting member 4 and the conductive rubber layer 6 is sufficiently excellent.

[0109] In X-ray diffraction, it is known that peaks originating from the (100) plane of the resin contained in the connecting member 4 are observed in the diffraction angle (2θ) range of 20 to 25°, while peaks originating from the (010) plane are observed at lower angles (for example, in the range of 2θ of 15 to 20°) in X-ray diffraction. If no peak originating from the (100) plane appears in X-ray diffraction, the maximum value of the diffraction intensity (CPS) in the diffraction angle (2θ) range of 20 to 25° is defined as the height of the peak originating from the (100) plane.

[0110] Furthermore, it is preferable that the surface of the connecting member 4 on which the conductive rubber layer 6 is provided has a ratio of 1.3 or more between the area of ​​the peak originating from the (010) plane and the area of ​​the peak originating from the (100) plane in X-ray diffraction [(010) plane area / (100) plane area]. If the ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane is 1.3 or more, the crystallinity of the surface of the connecting member 4 on which the conductive rubber layer 6 is provided is further reduced, and the adhesive strength between the connecting member 4 and the conductive rubber layer 6 is further improved.

[0111] In X-ray diffraction, there are cases where a peak originating from the (100) plane does not appear. In such cases, the area of ​​the peak originating from the (100) plane becomes 0, and the ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane [(010) plane area / (100) plane area] becomes ∞. This configuration is also one of the preferred embodiments.

[0112] The surface of the connecting member 4 on which the conductive rubber layer 6 is provided preferably has an average crystal size length of 10 μm or less in the region up to a depth of 250 μm. Here, the crystal size in the region from the surface of the connecting member 4 to a depth of 250 μm is measured using a polarizing microscope, and the long side of the crystals observed with the polarizing microscope is measured, and the average value of the long side lengths of the 20 observed crystals is taken as the average crystal size length. However, it is also preferable that there are no crystals in the region from the surface of the connecting member 4 to a depth of 250 μm (i.e., no crystals are observed with the polarizing microscope), that is, it is also preferable that the average crystal size length is 0 μm. Crystals of resin with a long side exceeding 10 μm have low reactivity with the conductive rubber layer 6. Therefore, if the average crystal size length in the region from the surface of the connecting member 4 to a depth of 250 μm is 10 μm or less, the adhesive strength between the conductive rubber layer 6 and the connecting member 4 is further improved.

[0113] <Manufacturing method for non-pneumatic tires> The non-pneumatic tire 1 of this embodiment can be obtained by injection molding skeletal members such as the connecting member 4 using a known method, then placing the conductive rubber layer 6 on the connecting member 4 (and the inner cylinder 2 and / or outer cylinder 3) and heat pressing. If an intervening layer 7 is provided between the connecting member 4 (and the inner cylinder 2 and / or outer cylinder 3) and the conductive rubber layer 6, the intervening layer 7 is provided between the connecting member 4 (and the inner cylinder 2 and / or outer cylinder 3) and the conductive rubber layer 6 and then heat pressing. Alternatively, the conductive rubber layer 6 may be surface treated beforehand.

[0114] When a non-pneumatic tire 1 includes an intervening layer 7, and the intervening layer 7 is an adhesive layer 8, the method for manufacturing the non-pneumatic tire 1 is: A step (1A) of applying a surface treatment to at least a portion of the surface of the conductive rubber layer 6 that will be bonded to the connecting member 4, (2A) A step of surface treatment is performed on at least a portion of the surface of the connecting member 4 that is to be bonded to the conductive rubber layer 6, such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [peak height originating from the (010) plane / peak height originating from the (100) plane] is 1.1 or more. Preferably, the process includes a step (3A) of bonding the surface-treated surface of the conductive rubber layer 6 and the surface-treated surface of the connecting member 4 with an adhesive. In the manufacturing method of the non-pneumatic tire 1 described above, including such a step can improve the reactivity between the surfaces to be bonded.

[0115] The order of process (1A) and process (2A) is not restricted.

[0116] By applying a surface treatment to at least a portion of the surface of the conductive rubber layer 6 that adheres to the connecting member 4, and providing a surface treatment layer 10, the reactivity of the conductive rubber layer 6 with respect to the connecting member 4 can be improved. Furthermore, by surface treatment applied to at least a portion of the surface of the connecting member 4 that adheres to the conductive rubber layer 6, such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction is 1.1 or more, the reactivity of the connecting member 4 to the conductive rubber layer 6 can be improved. Therefore, according to the manufacturing method of the non-pneumatic tire 1 of this embodiment, a non-pneumatic tire 1 with excellent adhesive strength between the connecting member 4 and the conductive rubber layer 6 can be easily obtained.

[0117] In the case where the non-pneumatic tire 1 includes an intervening layer 7 and the intervening layer 7 is an adhesive layer 8, the method for manufacturing the non-pneumatic tire 1 of this embodiment includes a step (1A) of applying a surface treatment to at least a portion of the surface of the conductive rubber layer 6 that is to be bonded to the connecting member 4. Here, as the surface treatment applied to the conductive rubber layer 6, chlorination treatment is preferred, as described in the "non-pneumatic tire" section of this embodiment. Furthermore, as the chemicals used for the chlorination treatment, an aqueous hypochlorous acid solution and chlorinated cyanuric acid are preferred.

[0118] In the case where the non-pneumatic tire 1 includes an intervening layer 7, and the intervening layer 7 is an adhesive layer 8, the manufacturing method of the non-pneumatic tire 1 according to this embodiment includes a step (2A) of surface treatment of at least a portion of the surface of the connecting member 4 to be bonded with the conductive rubber layer 6 such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [(010) plane peak height / (100) plane peak height] is 1.1 or more. Here, as the surface treatment applied to the connecting member 4, a combination of heat treatment and cooling treatment or solvent treatment is preferred.

[0119] As a surface treatment applied to the connecting member 4, the connecting member 4 made of a resin composition is heat-treated and then cooled, which reduces the crystallinity of the surface of the resin layer, making the peak originating from the (100) plane in X-ray diffraction smaller, and making the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane 1.1 or more. Here, the heat treatment temperature (the set temperature of the heat treatment apparatus) is preferably adjusted according to the melting point of the resin component used in the connecting member 4, the distance from the heat source to the connecting member 4, etc. For example, it is preferably above the melting temperature of the connecting member 4, and in one example, 430°C or higher is preferred. Furthermore, the cooling process is preferably rapid, for example, by pressing the connecting member 4 against the cooled metal plate. The cooling process causes the molten resin to solidify in a low-crystallinity state, resulting in a connecting member 4 with low crystallinity. The temperature of the cooling (rapid cooling) process depends on the temperature of the heat treatment, but is preferably 15°C or lower, and more preferably 10°C or lower.

[0120] Furthermore, by solvent treatment of the connecting member 4, which is made of a resin composition, the crystallinity of the surface of the connecting member 4 is reduced, which reduces the peak originating from the (100) plane in X-ray diffraction, and makes it possible to make the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane 1.1 or more. Here, the solvent used for solvent treatment depends on the type of resin component used in the connecting member 4, but for example, halogenated alcohols are preferred, and hexafluoroisopropanol (HFIP) is particularly preferred. HFIP has excellent solubility for crystalline polymers and is particularly useful for reducing the crystallinity of the surface of the connecting member 4. By solvent treatment of the connecting member 4, the surface of the connecting member 4 is dissolved, and when the solvent vaporizes (dries), the resin precipitates in a low-crystallinity state, resulting in a connecting member 4 with low crystallinity.

[0121] It is even more preferable that the surface treatment step for the connecting member 4 is performed such that the ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane in X-ray diffraction [height of the peak originating from the (010) plane / height of the peak originating from the (100) plane] for at least a portion of the surface of the connecting member 4 that is bonded to the conductive rubber layer 6 is 1.3 or more. By having at least a portion of the surface of the connecting member 4 that is bonded to the conductive rubber layer 6 have a ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane in X-ray diffraction [area of ​​the peak originating from the (010) plane / area of ​​the peak originating from the (100) plane] of 1.3 or more, the adhesive strength between the conductive rubber layer 6 and the connecting member 4 can be further improved.

[0122] In the case where the non-pneumatic tire 1 includes an intervening layer 7 and the intervening layer 7 is an adhesive layer 8, the method for manufacturing the non-pneumatic tire 1 of this embodiment includes a step (3A) of bonding the surface-treated surface of the conductive rubber layer 6 and the surface-treated surface of the connecting member 4 with an adhesive.

[0123] Furthermore, in the case where the non-pneumatic tire 1 includes an intervening layer 7, and the intervening layer 7 is an intervening rubber layer 9, the method for manufacturing the non-pneumatic tire is: The steps include: (1B) applying a surface treatment to at least a portion of the surface of the intervening rubber layer 9; (2B) A step of surface treatment is performed on at least a portion of the surface of the connecting member 4 such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [peak height originating from the (010) plane / peak height originating from the (100) plane] is 1.1 or more. Preferably, the process includes the step (3B) of providing the surface-treated surface of the intervening rubber layer 9 to the surface-treated surface of the connecting member 4 without using an adhesive. In the manufacturing method of the non-pneumatic tire 1 described above, including such a step can improve the reactivity between the surfaces to be bonded.

[0124] By applying a surface treatment to at least a portion of the surface of the intervening rubber layer 9 and providing a surface treatment layer 10, the reactivity of the intervening rubber layer 9 with respect to the connecting member 4 can be improved. Furthermore, by surface treatment applied to at least a portion of the surface of the connecting member 4 that adheres to the intervening rubber layer 9, such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction is 1.1 or more, the reactivity of the connecting member 4 to the intervening rubber layer 9 can be improved. Furthermore, by bonding the surface-treated surface of the intervening rubber layer 9 and the surface-treated surface of the connecting member 4 without using an adhesive, it is possible to obtain a non-pneumatic tire 1 with high adhesive strength between the intervening rubber layer 9 and the connecting member 4 while eliminating the complexity of the manufacturing process. Therefore, according to the manufacturing method of the non-pneumatic tire 1 of this embodiment, a non-pneumatic tire 1 with excellent adhesive strength between the connecting member 4 and the intervening rubber layer 9 can be easily obtained.

[0125] In the case where the non-pneumatic tire 1 includes an intervening layer 7, and the intervening layer 7 is an intervening rubber layer 9, the method for manufacturing the non-pneumatic tire 1 of this embodiment includes a step (1B) of applying a surface treatment to at least a part of the surface of the intervening rubber layer 9. Here, as the surface treatment applied to the conductive rubber layer 6, chlorination treatment is preferred, as described in the "non-pneumatic tire" section of this embodiment. Furthermore, as the chemicals used for the chlorination treatment, hypochlorous acid aqueous solution and chlorinated cyanuric acid are preferred.

[0126] In the case where the non-pneumatic tire 1 includes an intervening layer 7, and the intervening layer 7 is an intervening rubber layer 9, the manufacturing method of the non-pneumatic tire 1 according to this embodiment includes a step (2B) of surface treatment applied to at least a portion of the surface of the connecting member 4 that is bonded to the intervening rubber layer 9 such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [(010) plane peak height / (100) plane peak height] is 1.1 or more. Here, as the surface treatment applied to the connecting member 4, a combination of heat treatment and cooling treatment or solvent treatment is preferred.

[0127] As a surface treatment applied to the connecting member 4, the connecting member 4 made of a resin composition is heat-treated and then cooled, which reduces the crystallinity of the surface of the resin layer, making the peak originating from the (100) plane in X-ray diffraction smaller, and making the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane 1.1 or more. Here, the heat treatment temperature (the set temperature of the heat treatment apparatus) is preferably adjusted according to the melting point of the resin component used in the connecting member 4, the distance from the heat source to the connecting member 4, etc. For example, it is preferably above the melting temperature of the connecting member 4, and in one example, 430°C or higher is preferred. Furthermore, the cooling process is preferably rapid, for example, by pressing the connecting member 4 against the cooled metal plate. The cooling process causes the molten resin to solidify in a low-crystallinity state, resulting in a connecting member 4 with low crystallinity. The temperature of the cooling (rapid cooling) process depends on the temperature of the heat treatment, but is preferably 15°C or lower, and more preferably 10°C or lower.

[0128] Furthermore, by solvent treatment of the connecting member 4, which is made of a resin composition, the crystallinity of the surface of the connecting member 4 is reduced, which reduces the peak originating from the (100) plane in X-ray diffraction, and makes it possible to make the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane 1.1 or more. Here, the solvent used for solvent treatment depends on the type of resin component used in the connecting member 4, but for example, halogenated alcohols are preferred, and hexafluoroisopropanol (HFIP) is particularly preferred. HFIP has excellent solubility for crystalline polymers and is particularly useful for reducing the crystallinity of the surface of the connecting member 4. By solvent treatment of the connecting member 4, the surface of the connecting member 4 is dissolved, and when the solvent vaporizes (dries), the resin precipitates in a low-crystallinity state, resulting in a connecting member 4 with low crystallinity.

[0129] It is even more preferable that the surface treatment step for the connecting member 4 is performed such that the ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane in X-ray diffraction [height of the peak originating from the (010) plane / height of the peak originating from the (100) plane] for at least a portion of the surface of the connecting member 4 that is bonded to the intervening rubber layer 9 is 1.3 or more. By having the ratio of the area of ​​the peak originating from the (010) plane to the area of ​​the peak originating from the (100) plane in X-ray diffraction [area of ​​the peak originating from the (010) plane / area of ​​the peak originating from the (100) plane] for at least a portion of the surface of the connecting member 4 that is bonded to the intervening rubber layer 9 be 1.3 or more, the adhesive strength between the intervening rubber layer 9 and the connecting member 4 can be further improved.

[0130] In the case where the non-pneumatic tire 1 includes an intervening layer 7, and the intervening layer 7 is an intervening rubber layer 9, the manufacturing method of the non-pneumatic tire 1 according to this embodiment includes a step (3B) of joining the surface-treated surface of the intervening rubber layer 9 and the surface-treated surface of the connecting member 4 without using an adhesive. The joining step is preferably performed by heating while the surface-treated surface of the intervening rubber layer 9 and the surface-treated surface of the connecting member 4 are in contact. Here, the heating temperature is preferably 120°C to 150°C. If the heating temperature is 120°C or higher, the adhesive strength between the intervening rubber layer 9 and the connecting member 4 tends to improve, and if the heating temperature is 150°C or lower, deformation of the connecting member 4 tends to be suppressed.

[0131] The order of process (1B) and process (2B) is not restricted.

[0132] The manufacturing method of the non-pneumatic tire 1 of this embodiment may further include other steps. Other steps include the buffing (polishing) process described above. By smoothing the surface of the connecting member 4 through buffing, the contact area with the conductive rubber layer 6 can be increased.

[0133] The above explanation describes the manufacturing method of a non-pneumatic tire in relation to the relationship between the connecting member 4 and the conductive rubber layer 6 or intervening rubber layer 9. However, this explanation can also be applied to the relationship between the inner cylinder 2 and / or outer cylinder 3 and the conductive rubber layer 6 or intervening rubber layer 9. [Examples]

[0134] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to the following examples.

[0135] <Example 1> (1) Fabrication of skeletal members (connecting members, inner cylinder and outer cylinder) A resin composition is prepared using a polyester thermoplastic elastomer (TPC, manufactured by Toray Celanese Co., Ltd., trade name "Hytrel 5557"). The resin composition is injection molded at 260°C to produce a skeletal member.

[0136] (2) Preparation of conductive rubber layer The conductive rubber is prepared by mixing 100 parts by mass of styrene-butadiene rubber with 60 parts by mass of carbon black and appropriate amounts of additives such as vulcanizing chemicals, vulcanization accelerators, and softeners to create a rubber composition. After molding it into a predetermined shape, the conductive rubber layer is produced by vulcanizing it at 160°C for 15 minutes. Chemlok 7701 (manufactured by Lord Japan Inc.) is applied to the surface of the conductive rubber layer and subjected to chlorination treatment.

[0137] (3) Manufacturing of non-pneumatic tires A rubber composition is prepared by mixing 30 parts by mass of butadiene rubber and 70 parts by mass of natural rubber with 50 parts by mass of carbon black and appropriate amounts of additives such as vulcanizing chemicals, vulcanization accelerators, and softeners. After forming the composition into a predetermined shape, it is vulcanized at 160°C for 15 minutes to produce a rubber annular tread member. Chemlok 7701 (manufactured by Rode Japan Inc.) is applied to the inner circumferential surface of the tread member and subjected to chlorination treatment. The fabricated skeletal member and tread member are placed inside an envelope with the inner circumferential surface of the tread member in contact with the surface of the outer cylinder. The envelope is then placed in an autoclave (manufactured by Hanyuda Iron Works) and, under conditions of a temperature of 130°C and a pressure of 0.7 MPa, the pressure inside the envelope is reduced to -0.01 MPa (compared to atmospheric pressure) for 30 minutes to bond the tread member and skeletal member together and produce a non-pneumatic tire. The conductive rubber layer prepared using the above method is bonded to the non-pneumatic tire using a urethane-based adhesive (Road Corporation, product name "7542A / B") to produce a non-pneumatic tire having a conductive rubber layer.

[0138] <Example 2> A skeletal member and a tread member were fabricated in the same manner as in Example 1, and these were joined together to produce a non-pneumatic tire. Furthermore, a conductive rubber layer was fabricated in the same manner as in Example 1. Then, a conductive rubber layer having an intervening rubber layer was prepared using the method described below, and a non-pneumatic tire with a conductive rubber layer was prepared by bonding the conductive rubber layer with a non-pneumatic tire using the method described below, without using a urethane-based adhesive. (Fabrication of a conductive rubber layer having an intervening rubber layer and adhesion of the conductive rubber layer) A rubber composition constituting an interleaved rubber layer was prepared by blending 20 parts by mass of butadiene rubber and 80 parts by mass of natural rubber with 40 parts by mass of carbon black and appropriate amounts of additives such as vulcanizing chemicals, vulcanization accelerators, and softeners. Subsequently, the rubber composition constituting the interleaved rubber layer was layered with a conductive rubber layer and molded into a predetermined shape, and then vulcanized at 160°C for 15 minutes to produce a conductive rubber layer having an interleaved rubber layer. Chemlok 7701 (manufactured by Lord Japan Inc.) was applied to the surface of the interleaved rubber layer and subjected to chlorination treatment. The conductive rubber layer having the intervening rubber layer prepared by the above method was placed so that the chlorinated intervening rubber layer was in contact with the non-pneumatic tire, and bonded by heat pressing at a temperature of 130°C and a pressure of 0.7 MPa for 30 minutes.

[0139] <Comparative Example 1> A non-pneumatic tire was manufactured in the same manner as in Example 1, except that a conductive rubber layer was not provided.

[0140] <Evaluation Method> (1) Conductivity (surface resistivity) In Example 1, the surface resistivity of the conductive rubber layer of the obtained non-pneumatic tire was measured using a Custom CDM-2000D tester under a constant load at room temperature and in a drum durability test at 60 km / h before and after 20,000 km of driving. For Example 2 and Comparative Example 1, the surface resistivity of the conductive rubber layer of the obtained non-pneumatic tires was measured using a Custom CDM-2000D tester under a constant load at room temperature and in a drum durability test at 60 km / h before and after 20,000 km of driving. The evaluation results are shown in Table 1.

[0141] (2) Peel test In Example 1, the presence or absence of delamination of the conductive rubber layer was checked after the fabricated non-pneumatic tire was driven for 20,000 km. For Example 2 and Comparative Example 1, the presence or absence of delamination of the conductive rubber layer was checked after the fabricated non-pneumatic tires were driven for 20,000 km. The evaluation results are shown in Table 1.

[0142] [Table 1]

[0143] *1 Diene rubber: Styrene-butadiene rubber (emulsion polymerized SBR (St: 37% by mass) (manufactured by H%R, trade name "Vivatec 400")): 70% by mass, and solution polymerized SBR (St: 25% by mass, vinyl content 14% by mass) (manufactured by Firestone Polymers, trade name "TS038")): 30% by mass blend) *2 Carbon Black: N234, manufactured by CABOT, product name "VULCAN 7H" *3 Others: Sulfur, vulcanization accelerators, antioxidants, softeners, and fatty acid salts, etc. *4 OL: Overload, measurement impossible due to high resistance

[0144] Table 1 shows that the non-pneumatic tire of this embodiment has excellent conductivity and improved electrostatic properties. [Industrial applicability]

[0145] According to this disclosure, it is possible to provide a non-pneumatic tire with improved electrostatic properties and a method for manufacturing the same.

[0146] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] The SDGs have been proposed to realize a sustainable society. One embodiment of the present invention is considered to be a technology that can contribute to "No. 12: Responsible Consumption and Production" and "No. 13: Climate Action," among others. [Explanation of symbols]

[0147] 1: Non-pneumatic tires 2: Inner cylinder 3: Outer cylinder 4: Connecting member 4a: Inner part 4b:Outer part 5: Tread material O: Central axis D: Diameter in the radial direction of the tire 6: Conductive rubber layer 7: Intervening layer 8: Adhesive layer 9: Intervening rubber layer 10: Surface treatment layer

Claims

1. A non-pneumatic tire comprising: an inner cylinder fitted to the wheel; an outer cylinder surrounding the inner cylinder from the outside in the tire radial direction; a plurality of connecting members arranged between the inner cylinder and the outer cylinder along the tire circumferential direction, connecting the two cylinders together; and a tread member provided on the outer side of the outer cylinder in the tire radial direction, The inner cylinder, the outer cylinder, and the connecting member are made of a resin composition. At least the connecting member has a conductive rubber layer provided so as to connect the inner cylinder and the outer cylinder, The conductive rubber layer comprises a diene-based rubber and carbon black. A non-pneumatic tire in which the carbon black content is 50 parts by mass or more per 100 parts by mass of the diene-based rubber.

2. The non-pneumatic tire according to claim 1, further comprising an intervening layer between the connecting member and the conductive rubber layer.

3. The non-pneumatic tire according to claim 2, wherein the intervening layer is an adhesive layer or an intervening rubber layer.

4. The intervening layer is the adhesive layer, The non-pneumatic tire according to claim 3, wherein the adhesive layer is made of a urethane-based adhesive or an epoxy adhesive.

5. The intervening layer is the adhesive layer, The conductive rubber layer includes a surface treatment layer on the surface that comes into contact with the connecting member. The non-pneumatic tire according to claim 3, wherein the surface treatment layer is a chlorinated layer.

6. The intervening layer is the intervening rubber layer, The intervening rubber layer includes a surface treatment layer on the surface that comes into contact with the connecting member. The non-pneumatic tire according to claim 3, wherein the surface treatment layer is a chlorinated layer.

7. The non-pneumatic tire according to claim 1, wherein the surface of the connecting member on which the conductive rubber layer is provided has an average length of crystal size in the region up to a depth of 250 μm of 10 μm or less.

8. When a non-pneumatic tire is driven 20,000 km on a durability drum test machine, the conductive rubber layer has a surface resistivity of 1 × 10⁻⁶ before and after driving. １０ A non-pneumatic tire according to claim 1, wherein the impedance is less than or equal to Ω.

9. A method for manufacturing a non-pneumatic tire according to claim 5, A step (1A) of applying a surface treatment to at least a portion of the surface of the conductive rubber layer that will be bonded to the connecting member, Step (2A) is to perform a surface treatment on at least a portion of the surface of the connecting member that is to be bonded to the conductive rubber layer such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [peak height originating from the (010) plane / peak height originating from the (100) plane] is 1.1 or more, A method for manufacturing a non-pneumatic tire, comprising the step (3A) of bonding the surface-treated surface of the conductive rubber layer and the surface-treated surface of the connecting member with an adhesive.

10. A method for manufacturing a non-pneumatic tire according to claim 6, The steps include: (1B) applying a surface treatment to at least a portion of the surface of the intervening rubber layer; (2B) A step of surface treatment being performed on at least a portion of the surface of the connecting member such that the ratio of the peak height originating from the (010) plane to the peak height originating from the (100) plane in X-ray diffraction [peak height originating from the (010) plane / peak height originating from the (100) plane] is 1.1 or more, A method for manufacturing a non-pneumatic tire, comprising the step (3B) of providing the surface-treated surface of the intervening rubber layer to the surface-treated surface of the connecting member without using an adhesive.

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