阅读说明：本技术 轮胎 (Tyre for vehicle wheels ) 是由 山下博雅 于 2018-03-29 设计创作，主要内容包括：一种轮胎,其具有由含有热塑性弹性体的树脂材料制成的轮胎骨架体,其中热塑性弹性体的使用小角X射线散射法测量的非结晶部的厚度La落在12.3nm～13.9nm的范围内。(A tire having a tire frame made of a resin material containing a thermoplastic elastomer, wherein a thickness La of an amorphous portion of the thermoplastic elastomer measured using a small-angle X-ray scattering method falls within a range of 12.3nm to 13.9 nm.)

1. A tire comprising a tire frame formed of a resin material containing a thermoplastic elastomer, wherein a thickness La of an amorphous portion of the thermoplastic elastomer measured by a small-angle X-ray scattering method is in a range of 12.3nm to 13.9 nm.

2. The tire of claim 1, wherein the thermoplastic elastomer has a long period L, as measured by small angle X-ray scattering, in the range of 15.6nm to 17.1 nm.

3. The tire according to claim 1 or 2, wherein the thermoplastic elastomer has a degree of orientation f in the range of-0.08 to 0.08 as measured by small angle X-ray scattering.

4. A tire according to any one of claims 1 to 3, wherein said thermoplastic elastomer is a polyester-based thermoplastic elastomer.

Technical Field

The present disclosure relates to tires.

Background

Conventionally, as a pneumatic tire used on a motor vehicle such as a passenger car, a tire in which a resin material, particularly a thermoplastic resin or a thermoplastic elastomer or the like is used as a material has been examined from the viewpoint of weight reduction, ease of molding, and recyclability. Such thermoplastic polymer materials (i.e., thermoplastic resins) have many advantages from the viewpoint of improving productivity such as that they are injection moldable.

For example, there has been proposed a tire formed of a thermoplastic resin material and including a ring-shaped tire frame, the tire having a reinforcing cord member wound in a circumferential direction on an outer circumferential portion of the tire frame to form a reinforcing cord layer, and in which the thermoplastic resin material contains at least a polyester-based thermoplastic elastomer (see patent document 1).

[ patent document 1] Japanese patent application laid-open (JP-A) No.2012-046025

Disclosure of Invention

Problems to be solved by the invention

In the tire frame produced using the resin material, the state of the tire frame is affected by the state of the resin material in the produced tire. Therefore, it is considered that the characteristics (e.g., durability, etc.) of the tire frame, the final tire, can be improved to a desired state by appropriately controlling the state of the resin material. However, there is still a contrivance regarding that the state of the resin material should be controlled from this viewpoint to achieve desired characteristics.

In view of the above circumstances, an object of the present disclosure is to provide a tire having excellent durability, which includes a tire frame containing a thermoplastic elastomer as a resin contained in a resin material.

Means for solving the problems

The above problems can be solved by the following disclosure.

<1> a tire comprising a tire frame formed of a resin material containing a thermoplastic elastomer, wherein the thermoplastic elastomer has a thickness La of an amorphous portion measured by a small-angle X-ray scattering method in a range of 12.3nm to 13.9 nm.

ADVANTAGEOUS EFFECTS OF INVENTION

according to the present disclosure, it is possible to provide a tire having excellent durability, which includes a tire frame containing a thermoplastic elastomer as a resin contained in a resin material.

Drawings

FIG. 1A is a perspective view illustrating a cross-section of a portion of a tire according to an embodiment of the present disclosure;

FIG. 1B is a cross-sectional view of a bead portion mounted to a rim;

Fig. 2 is a sectional view taken along the tire rotation axis, illustrating a state in which a reinforcing cord is buried in the crown portion of the casing of the tire according to the present embodiment; and

Fig. 3 is a view for explaining an operation of burying the reinforcing cord in the crown portion of the casing using the cord heating device and the roller.

Detailed Description

Hereinafter, specific embodiments of the present disclosure will be described in detail. However, the present disclosure is by no means limited to the following embodiments, but can be carried out with modification as appropriate within the intended scope of the present disclosure.

The term "resin" as used herein is a concept covering thermoplastic resins, thermoplastic elastomers, and thermosetting resins, but does not include vulcanized rubbers. Further, in the following description of the resins, the term "the same kind" means that the resins of interest have a common skeleton as a skeleton constituting a main chain of each resin, as in, for example, an ester-based resin or a styrene-based resin, or the like.

The term "thermoplastic elastomer" as used herein refers to a high molecular compound composed of a copolymer containing a polymer constituting a crystalline, high-melting-point hard segment or a hard segment having high cohesion; and a polymer constituting a soft segment of non-crystalline, low glass transition temperature. Such thermoplastic elastomers soften and flow with increasing temperature and become relatively hard and strong upon cooling. Further, the thermoplastic elastomer is a polymer compound having rubber-like elasticity.

The term "hard segment" as used herein refers to a relatively harder component as compared to a soft segment, and the term "soft segment" as used herein refers to a relatively softer component as compared to a hard segment. The hard segment is preferably a molecular confinement component that functions as a crosslinking point of the crosslinked rubber to suppress plastic deformation. Meanwhile, the soft segment is preferably a soft component exhibiting rubber elasticity.

In the present specification, those numerical ranges indicated by "to" each mean a range including numerical values indicated before and after "to" as a lower limit value and an upper limit value, respectively.

The term "step" as used herein encompasses not only an independent step, but also a step that is not clearly distinguishable from other steps, so long as the intended purpose of the step is achieved.

< tire >

The tire according to the present embodiment includes a tire frame formed of a resin material containing a thermoplastic elastomer (i.e., the tire frame is formed partly or entirely of the resin material alone). The thermoplastic elastomer has a thickness La of an amorphous portion measured by a small-angle X-ray scattering method in a range of 12.3nm to 13.9 nm.

According to the studies conducted by the present inventors, it was shown that a tire having a tire frame formed using a thermoplastic elastomer having a thickness La of an amorphous portion within the above range exhibits more excellent durability (particularly, crack resistance) than a tire having a tire frame formed using only a thermoplastic elastomer having a thickness La of an amorphous portion outside the above range.

Thickness La of amorphous part

In the present specification, the thickness La of the amorphous portion of the thermoplastic elastomer means the thickness of one amorphous portion in the repeating structure of the crystalline portion and the amorphous portion of the hard segment of the thermoplastic elastomer. In the present specification, the thickness La of the amorphous portion is measured by a small-angle X-ray scattering method using a sample collected from a tire frame body or a sample prepared from a resin material for forming a tire frame body as described below.

The long period L is defined as 2 π/qmax, where qmax is the wavenumber q [ nm-1] showing the primary peak of small angle X-ray scattering. Further, the thickness of the crystal portion is defined as Lc. This Lc can be calculated from the intersection of a function representing the initial slope and a function representing the minimum value in the following one-dimensional autocorrelation function γ (r). By using these elements, the thickness La of the amorphous portion is defined as "La ═ L — Lc".

The tire having the tire frame formed using the thermoplastic elastomer having the thickness La of the amorphous portion in the above range exhibits excellent durability. The reason is unclear; however, the following is presumed.

The thickness La of the amorphous portion of 12.3nm or more is considered to indicate that the molecular chain of the amorphous portion is elongated in the repeating structure composed of the crystalline portion and the amorphous portion of the hard segment. This results in improvement in the orientation (i.e., degree of alignment) of the molecular chains of the amorphous portion. As a result, the cushioning property of the thermoplastic elastomer is improved, and the durability of the tire, particularly the crack resistance against impact, is improved.

On the other hand, the thickness La of the amorphous portion of 13.9nm or less is considered to indicate that the molecular chain of the amorphous portion is not excessively elongated in the repeating structure composed of the crystalline portion and the amorphous portion of the hard segment. Therefore, the decrease in the strength of the molecular chain of the amorphous portion due to excessive elongation is suppressed. As a result, the strength of the thermoplastic elastomer is secured, and the durability of the tire, particularly the crack resistance against impact, is improved.

The thickness La of the amorphous portion is more preferably in the range of 12.5nm to 13.7nm, still more preferably in the range of 12.8nm to 13.4 nm.

The method for controlling the value of the thickness La of the amorphous portion of the thermoplastic elastomer is not particularly limited. For example, the value of the thickness La of the amorphous portion may be reduced by raising the heating temperature (e.g., the barrel temperature and/or the mold temperature at the time of injection molding) at the time of forming the tire frame. On the other hand, the value of the thickness La of the amorphous portion may be increased by lowering the heating temperature (e.g., the barrel temperature and/or the mold temperature) when forming the tire frame.

Long period L

In the tire according to the present embodiment, the long period L of the thermoplastic elastomer contained in the tire frame as measured by the small-angle X-ray scattering method is preferably in the range of 15.6nm to 17.1 nm.

In the present specification, the long period L of the thermoplastic elastomer refers to the total value of the thickness of the crystalline portion and the thickness of the amorphous portion in the repeating unit composed of one crystalline portion and one amorphous portion in the repeating structure composed of the crystalline portion and the amorphous portion of the hard segment of the thermoplastic elastomer. In the present specification, the value of the long period L is determined by a small-angle X-ray scattering method using a sample collected from a tire frame body or a sample prepared from a resin material for forming a tire frame body as follows.

The long period L is defined as a value of r, which corresponds to a primary peak obtained by plotting a one-dimensional autocorrelation function γ (r) determined by the value of the one-dimensional autocorrelation function with respect to r. In the following formula, "q" represents a wave number [ nm-1] showing a primary peak of small-angle X-ray scattering; "r" has a dimension (dimension) of distance at any point in polymer space; "I (q)" represents the X-ray scattering intensity.

One-dimensional autocorrelation function γ (r) ═ q2cos (rq) dq)/((jj (q) q2dq)

By controlling the long period L within the above range, the durability of the tire, particularly the crack resistance against impact, is improved. This is considered to be because, when the long period L is 15.6nm or more, the friction between molecules decreases, and the durability of the tire is thereby improved. Meanwhile, when the long period L is 17.1nm or less, the increase in elastic modulus due to excessive elongation of the molecular chain is suppressed, and from this viewpoint as well, it is considered that the durability of the tire is improved.

The long period L is more preferably in the range of 15.8nm to 17.0nm, still more preferably in the range of 16.1nm to 16.7 nm.

The value of the long period L increases as the thickness La of the amorphous portion of the thermoplastic elastomer increases. Further, as the growth of the crystal portions in the thermoplastic elastomer is promoted and the thickness of each crystal portion is thereby increased, the value of the long period L is increased. The larger the long period L, the higher the melting point of the thermoplastic elastomer tends to be.

The method of controlling the value of the long period L of the thermoplastic elastomer is not particularly limited, and examples thereof include the method of controlling the value of the thickness La of the amorphous portion as described above. Further, the value of the long period L may be increased by increasing the heating temperature (e.g., the barrel temperature and/or the mold temperature) at the time of forming the tire frame, thereby prolonging the time required for cooling and promoting the growth of crystals. On the other hand, the value of the long period L can be reduced by lowering the heating temperature (e.g., the barrel temperature and/or the mold temperature) at the time of forming the tire frame, thereby shortening the time required for cooling and suppressing the growth of crystals.

Degree of orientation f

In the tire according to the present embodiment, the degree of orientation f of the thermoplastic elastomer contained in the tire frame as measured by a small-angle X-ray scattering method is preferably in the range of-0.08 to 0.08 (i.e., the absolute value of the degree of orientation f is preferably 0 to 0.08).

In the present specification, the orientation degree f of the thermoplastic elastomer means the orientation degree of molecules in the crystalline portion of the hard segment in the thermoplastic elastomer. The smaller the absolute value of the orientation degree f is, the more random the orientation state of the molecules is. In the present specification, the orientation degree f is a value calculated using the following formula, where "θ" represents a crystal orientation angle measured by a small-angle X-ray scattering method using a sample collected from a tire frame body or a sample prepared from a resin material for forming a tire frame body:

f＝1/2×(3×<cosθ>-1)

When the orientation degree f is in the range of-0.08 to 0.08, the durability of the tire, particularly the crack resistance against impact, is improved. This is presumably because, by controlling the degree of orientation f within the above range, the mechanical input to the carcass during running can be effectively dispersed, and the mechanical strength is thereby improved.

The degree of orientation f is more preferably in the range of-0.08 to 0.04, still more preferably in the range of-0.02 to 0.02.

The method for controlling the value of the orientation degree f of the thermoplastic elastomer is not particularly limited. The orientation degree f can be controlled by, for example, adjusting the temperature of the thermoplastic elastomer, the cylinder temperature, the mold temperature, the cooling speed, and the like when injection molding is performed to form the tire frame. For example, the degree of orientation f can be reduced by increasing the temperature at the time of injection molding the thermoplastic elastomer (i.e., increasing the temperature of the thermoplastic elastomer) to reduce the viscosity, and increasing the barrel temperature and/or the mold temperature to prolong the time required for cooling and to relax the molecular motion.

Degree of crystallinity Xc

In the tire according to the present embodiment, the crystallinity Xc of the thermoplastic elastomer contained in the tire frame measured by the wide-angle X-ray scattering method is preferably in the range of 12% to 45%.

In the present specification, the crystallinity Xc of the thermoplastic elastomer represents the proportion of crystalline portions in the hard segment of the thermoplastic elastomer. The larger the value of the crystallinity Xc, the higher the proportion of crystalline portions and the lower the proportion of amorphous portions. In the present specification, the crystallinity Xc is a value calculated by the following formula, in which a scattering intensity area of a crystal and a scattering intensity area of an amorphous (amophorus) are determined by a wide angle X-ray scattering method using a sample collected from a tire carcass or a sample prepared from a resin material for forming a tire carcass:

Xc (%) - (area of scattering intensity of crystal)/(area of scattering intensity of crystal + area of scattering intensity of amorphous) × 100

In the case where the crystallinity Xc is in the range of 12% to 45%, the durability of the tire, particularly the crack resistance against impact, is improved. This is presumably because the heat resistance is improved when the crystallinity Xc is 12% or more, and the crystal-originated collapse phenomenon is suppressed when the crystallinity Xc is 45% or less.

The crystallinity Xc is more preferably 12% to 37%.

The method for controlling the value of the crystallinity Xc of the thermoplastic elastomer is not particularly limited. For example, the crystallinity Xc may be increased by increasing the heating temperature (e.g., the barrel temperature and/or the mold temperature) when forming the tire frame, thereby prolonging the time required for cooling and promoting the growth of crystals. On the other hand, the crystallinity Xc can be reduced by lowering the mold temperature during cooling, thereby shortening the time required for cooling and suppressing the growth of crystals.

[ resin Material ]

The resin material contains a thermoplastic elastomer, and may further contain components other than the thermoplastic elastomer, such as additives, if necessary.

The kind of the thermoplastic elastomer used for forming the tire frame is not particularly limited. Examples thereof include polyester-based thermoplastic elastomers (TPC), polyamide-based thermoplastic elastomers (TPA), polystyrene-based thermoplastic elastomers (TPS), polyurethane-based thermoplastic elastomers (TPU), olefin-based thermoplastic elastomers (TPO), thermoplastic rubber crosslinked bodies (TPV), and other thermoplastic elastomers (TPZ). With regard to the definition and classification of these thermoplastic elastomers, reference may be made to JIS K6418.

Among the thermoplastic elastomers exemplified above, polyester-based thermoplastic elastomers are preferable because of the advantageous feature of having more excellent bending fatigue resistance than other thermoplastic elastomers. Tires comprising such polyester-based thermoplastic elastomers exhibit high durability because the high bending fatigue resistance of the polyester-based thermoplastic elastomers suppresses the generation and growth of fatigue cracks against repeatedly applied bending stress.

Thermoplastic elastomer of polyester series

The polyester-based thermoplastic elastomer is an elastic polymer compound which is a thermoplastic resin material composed of a copolymer including a polyester-containing polymer constituting a crystalline, high-melting-point hard segment and a polymer constituting an amorphous, low-glass-transition-temperature soft segment. The term "polyester-based thermoplastic elastomer" as used herein means a thermoplastic elastomer whose structure includes a partial structure composed of a polyester. Examples of the polyester-based thermoplastic elastomer include ester-based thermoplastic elastomers (TPC) defined in JIS K6418: 2007.

The polyester-based thermoplastic elastomer may be, for example, a material in which at least polyester constitutes a crystalline, high-melting-point hard segment and other polymer (for example, polyester, polyether, or the like) constitutes an amorphous, low-glass-transition-temperature soft segment.

As the polyester constituting the hard segment, for example, an aromatic polyester can be used. The aromatic polyester may be formed from, for example, an aromatic dicarboxylic acid or an ester-forming derivative thereof and an aliphatic diol.

An example of an aromatic polyester is polybutylene terephthalate derived from terephthalic acid and/or dimethyl terephthalate and 1, 4-butanediol. The aromatic polyester may also be derived from a dicarboxylic acid component (e.g., 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 an ester-forming derivative thereof) and a diol component, such as a diol having a molecular weight of 300 or less (e.g., an aliphatic diol such as ethylene glycol, trimethylene glycol, pentanediol, hexanediol, neopentyl glycol, or decanediol; an alicyclic diol such as 1, 4-cyclohexanedimethanol or tricyclodecanedimethanol; or an aromatic diol such as benzenedimethanol, bis (p-hydroxy) biphenyl, bis (p-hydroxyphenyl) propane, 2-bis [4- (2-hydroxyethoxy) phenyl ] propane, bis [4- (2-hydroxy) phenyl ] sulfone, bis (p-hydroxyphenyl) sulfone, or a mixture thereof), Polyesters of 1, 1-bis [4- (2-hydroxyethoxy) phenyl ] cyclohexane, 4' -dihydroxy-p-terphenyl (4,4' -dihydroxy-p-terphenyl) or 4,4' -dihydroxy-p-quaterphenyl). Alternatively, the aromatic polyester may be a copolyester in which two or more of these dicarboxylic acid component and diol component are used in combination. For example, a polyfunctional carboxylic acid component having three or more functions, a polyfunctional oxoacid component, or a polyfunctional hydroxyl component may be copolymerized in a range of 5 mol% or less.

Examples of the polyester constituting the hard segment include polyethylene terephthalate, polybutylene terephthalate, polymethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, with polybutylene terephthalate being preferred.

The polymer constituting the soft segment may be, for example, an aliphatic polyester or an aliphatic polyether.

Examples of aliphatic polyethers include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (butylene oxide) glycol, poly (hexylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide addition polymers of poly (propylene oxide) glycol, and copolymers of ethylene oxide and tetrahydrofuran.

Examples of the aliphatic polyesters include poly (. epsilon. -caprolactone), polyheptalactone, polycaprylolactone, polybutylene adipate and polyethylene adipate.

Among these aliphatic polyethers and aliphatic polyesters, from the viewpoint of the elastic properties of the resulting polyester block copolymer, for example, poly (oxybutylene) glycol, an ethylene oxide adduct of poly (propylene oxide) glycol, poly (. epsilon. -caprolactone), polybutylene adipate, or polyethylene adipate is preferable as the polymer constituting the soft segment.

The number average molecular weight of the polymer (i.e., polyester) constituting the hard segment is preferably 300 to 6,000 from the viewpoint of toughness and low-temperature flexibility.

Meanwhile, the number average molecular weight of the polymer constituting the soft segment is preferably 300 to 6,000 from the viewpoint of toughness and flexibility at low temperature.

Further, from the viewpoint of moldability of the tire carcass, the mass ratio (x: y) of the hard segment (x) to the soft segment (y) is preferably 99:1 to 20:80, more preferably 98:2 to 30: 70.

Examples of the combination of the hard segment and the soft segment include any of the above-described hard segments and any of the above-described soft segments. Among them, as a combination of a hard segment and a soft segment, a combination in which the hard segment is polybutylene terephthalate and the soft segment is an aliphatic polyether is preferable, and a combination in which the hard segment is polybutylene terephthalate and the soft segment is poly (ethylene oxide) glycol is more preferable.

As commercially available products of the polyester-based thermoplastic elastomer, for example, "HYTREL" series (e.g., 3046, 5557, 6347, 4047N, and 4767N, etc.) manufactured by DuPont-Toray co., ltd., and "perprene" series (e.g., P30B, P40B, P40H, P55B, P70B, P150B, P280B, E450B, P150M, S1001, S2001, S5001, S6001, and S9001, etc.) manufactured by TOYOBO co.

The polyester-based thermoplastic elastomer can be synthesized by copolymerizing a polymer constituting a hard segment and a polymer constituting a soft segment by a known method.

In the present embodiment, when the resin material contains a polyester-based thermoplastic elastomer, the content ratio of the polyester-based thermoplastic elastomer with respect to the entire thermoplastic elastomer contained in the resin material is not particularly limited; however, it is preferably 50% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more, relative to the total amount of the entire resin. When the content of the polyester-based thermoplastic elastomer is 50% by mass or more with respect to the total amount of the thermoplastic elastomer, the characteristics of the polyester-based thermoplastic elastomer can be sufficiently exhibited, so that the durability of the tire is easily further improved.

Thermoplastic polyamide elastomers

The term "polyamide-based thermoplastic elastomer" as used herein means a thermoplastic resin material composed of a copolymer including a polymer constituting a crystalline, high-melting-point hard segment and a polymer constituting a non-crystalline, low-glass transition-temperature soft segment, wherein the polymer constituting the hard segment has an amide bond (-CONH-) in its main chain.

Examples of the polyamide-based thermoplastic elastomer include materials in which at least polyamide constitutes a crystalline, high-melting-point hard segment and other polymer (for example, polyester or polyether, etc.) constitutes an amorphous, low-glass-transition-temperature soft segment. The polyamide-based thermoplastic elastomer can be formed using a chain extender such as a dicarboxylic acid in addition to the hard segment and the soft segment.

specific examples of the polyamide-based thermoplastic elastomer include an amide-based thermoplastic elastomer (TPA) as defined in JIS K6418:2007 and ｃA polyamide-based elastomer described in JP-A No. 2004-346273.

In the polyamide-based thermoplastic elastomer, the polyamide constituting the hard segment is, for example, a polyamide formed from a monomer represented by the following formula (1) or formula (2).

HNR-COOH

Formula (1)

[ wherein R1 represents a hydrocarbon molecular chain having 2 to 20 carbon atoms (e.g., an alkylene group having 2 to 20 carbon atoms) ]

[ wherein R2 represents a hydrocarbon molecular chain having 3 to 20 carbon atoms (e.g., an alkylene group having 3 to 20 carbon atoms) ]

In the formula (1), R1 is preferably a hydrocarbon molecular chain having 3 to 18 carbon atoms (e.g., an alkylene group having 3 to 18 carbon atoms), more preferably a hydrocarbon molecular chain having 4 to 15 carbon atoms (e.g., an alkylene group having 4 to 15 carbon atoms), and particularly preferably a hydrocarbon molecular chain having 10 to 15 carbon atoms (e.g., an alkylene group having 10 to 15 carbon atoms).

Further, in the formula (2), R2 is preferably a hydrocarbon molecular chain having 3 to 18 carbon atoms (for example, an alkylene group having 3 to 18 carbon atoms), more preferably a hydrocarbon molecular chain having 4 to 15 carbon atoms (for example, an alkylene group having 4 to 15 carbon atoms), and particularly preferably a hydrocarbon molecular chain having 10 to 15 carbon atoms (for example, an alkylene group having 10 to 15 carbon atoms).

Examples of the monomer represented by formula (1) or formula (2) include ω -aminocarboxylic acids and lactams. Examples of the polyamide constituting the hard segment include a polycondensate of an ω -aminocarboxylic acid or a lactam, and a copolycondensate of a diamine and a dicarboxylic acid.

Examples of the omega-aminocarboxylic acid include aliphatic omega-aminocarboxylic acids having 5 to 20 carbon atoms, such as 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminocaprylic acid, 10-aminocaprylic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Examples of the lactam include aliphatic lactams having 5 to 20 carbon atoms, such as lauryl lactam,. epsilon. -caprolactam, undecalactam,. omega. -enantholactam and 2-pyrrolidone.

Examples of the diamine include diamine compounds such as aliphatic diamines having 2 to 20 carbon atoms (e.g., ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2, 4-trimethylhexamethylenediamine, 2,4, 4-trimethylhexamethylenediamine, 3-methylpentamethylenediamine, m-xylylenediamine, and the like).

The dicarboxylic acid may be represented by HOOC- (R3) m-COOH (R3: hydrocarbon molecular chain having 3 to 20 carbon atoms, m: 0 or 1), and examples thereof include aliphatic dicarboxylic acids having 2 to 20 carbon atoms, such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, and the like.

As the polyamide constituting the hard segment, a polyamide obtained by ring-opening polycondensation of lauryl lactam, epsilon-caprolactam or undecamide can be preferably used.

Examples of the polymer constituting the soft segment include polyesters and polyethers, specifically, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and ABA type triblock polyether. These polymers may be used alone or in combination of two or more thereof. Further, polyether diamine obtained by reacting an end of polyether with ammonia or the like can also be used.

The term "ABA type triblock polyether" as used herein refers to a polyether represented by the following formula (3).

[ wherein x and z each represent an integer of 1 to 20, and y represents an integer of 4 to 50 ]

In the formula (3), x and z are each preferably an integer of 1 to 18, more preferably an integer of 1 to 16, still more preferably an integer of 1 to 14, and particularly preferably an integer of 1 to 12. In the formula (3), y is preferably an integer of 5 to 45, more preferably an integer of 6 to 40, still more preferably an integer of 7 to 35, and particularly preferably an integer of 8 to 30.

Examples of the combination of the hard segment and the soft segment include any of the above-described hard segments and any of the above-described soft segments. Among them, as the combination of the hard segment and the soft segment, a combination of a ring-opened polycondensate of lauryl lactam and polyethylene glycol, a combination of a ring-opened polycondensate of lauryl lactam and polypropylene glycol, a combination of a ring-opened polycondensate of lauryl lactam and polytetramethylene ether glycol, and a combination of a ring-opened polycondensate of lauryl lactam and ABA type triblock polyether are preferable, and a combination of a ring-opened polycondensate of lauryl lactam and ABA type triblock polyether is more preferable.

the number average molecular weight of the polymer (i.e., polyamide) constituting the hard segment is preferably 300 to 15,000 from the viewpoint of melt moldability. Meanwhile, the number average molecular weight of the polymer constituting the soft segment is preferably 200 to 6,000 from the viewpoint of toughness and flexibility at low temperature. Further, from the viewpoint of moldability of the tire carcass, the mass ratio (x: y) of the hard segment (x) to the soft segment (y) is preferably 50:50 to 90:10, more preferably 50:50 to 80: 20.

The polyamide-based thermoplastic elastomer can be synthesized by copolymerizing a polymer constituting a hard segment and a polymer constituting a soft segment by a known method.

As commercially available products of the polyamide-based thermoplastic elastomer, for example, "UBESTA XPA" series (for example, XPA9063X1, XPA9055X1, XPA9048X2, XPA9048X1, XPA9040X1, XPA9040X2, XPA9044 and the like) manufactured by UBE Industries, Ltd., and "VESTAMID" series (for example, E40-S3, E47-S1, E47-S3, E55-S1, E55-S3, EX9200, E50-R2 and the like) manufactured by Daicel-Evonik Ltd.

Polystyrene-based thermoplastic elastomers

Examples of polystyrene-based thermoplastic elastomers include materials in which at least polystyrene constitutes a hard segment and other polymers (e.g., polybutadiene, polyisoprene, polyethylene, hydrogenated polybutadiene, hydrogenated polyisoprene, or the like) constitute a non-crystalline, low glass transition temperature soft segment. As the polystyrene constituting the hard segment, for example, one obtained by a known radical polymerization method, an ionic polymerization method or the like can be preferably used, and specific examples of such polystyrene include polystyrene obtained by anionic living polymerization. Examples of the polymer constituting the soft segment include polybutadiene, polyisoprene, and poly (2, 3-dimethylbutadiene).

Examples of the combination of the hard segment and the soft segment include any of the above-described hard segments and any of the above-described soft segments. Among them, as the combination of the hard segment and the soft segment, a combination of polystyrene and polybutadiene or a combination of polystyrene and polyisoprene is preferable. In order to suppress undesired crosslinking reactions of the thermoplastic elastomer, the soft segment is preferably hydrogenated.

The number average molecular weight of the polymer (i.e., polystyrene) constituting the hard segment is preferably 5,000 to 500,000, more preferably 10,000 to 200,000.

Meanwhile, the number average molecular weight of the polymer constituting the soft segment is preferably 5,000 to 1,000,000, more preferably 10,000 to 800,000, and still more preferably 30,000 to 500,000. Further, from the viewpoint of moldability of the tire carcass, the volume ratio (x: y) of the hard segment (x) to the soft segment (y) is preferably 5:95 to 80:20, more preferably 10:90 to 70: 30.

The polystyrene-based thermoplastic elastomer can be synthesized by copolymerizing a polymer constituting a hard segment and a polymer constituting a soft segment by a known method.

Examples of the polystyrene-based thermoplastic elastomer include styrene-butadiene-based copolymers [ e.g., SBS (polystyrene-poly (butylene) block-polystyrene), SEBS (polystyrene-poly (ethylene/butylene) block-polystyrene) ]; styrene-isoprene copolymers (e.g., polystyrene-polyisoprene block-polystyrene); and styrene-propylene-based copolymers [ for example, SEP (polystyrene- (ethylene/propylene) block), SEPs (polystyrene-poly (ethylene/propylene) block-polystyrene), SEEPS (polystyrene-poly (ethylene-ethylene/propylene) block-polystyrene), and SEB (polystyrene (ethylene/butylene) block) ].

As commercial products of polystyrene-based thermoplastic elastomers, for example, "TUFTEC" series (e.g., H1031, H1041, H1043, H1051, H1052, H1053, H1062, H1082, H1141, H1221, and H1272, etc.) manufactured by Asahi Kasei Corporation, and "SEBS" series (e.g., 8007 and 8076, etc.) and "SEPS" series (e.g., 2002 and 2063, etc.) manufactured by Kuraray co.

Polyurethane-based thermoplastic elastomer

Examples of the polyurethane-based thermoplastic elastomer include materials in which at least polyurethane constitutes a hard segment forming pseudo-crosslinking by physical aggregation and other polymers constitute a soft segment of non-crystalline, low glass transition temperature.

Specific examples of the polyurethane-based thermoplastic elastomer include polyurethane-based thermoplastic elastomers (TPUs) defined in JIS K6418: 2007. The polyurethane-based thermoplastic elastomer may be represented as a copolymer including a soft segment having a unit structure represented by the following formula a and a hard segment having a unit structure represented by the following formula B.

Formula A: formula B:

[ wherein P represents a long-chain aliphatic polyether or a long-chain aliphatic polyester; r represents an aliphatic hydrocarbon, an alicyclic hydrocarbon or an aromatic hydrocarbon; p' represents a short-chain aliphatic, alicyclic or aromatic hydrocarbon

As the long-chain aliphatic polyether or long-chain aliphatic polyester represented by P in the formula A, for example, those having a molecular weight of 500 to 5,000 can be used. P is derived from a diol compound containing a long-chain aliphatic polyether or a long-chain aliphatic polyester represented by P. Examples of such diol compounds include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polybutylene adipate glycol, poly-epsilon-caprolactone glycol, poly (hexamethylene carbonate) glycol, and ABA type triblock polyether having a molecular weight in the above range.

These diol compounds may be used alone or in combination of two or more thereof.

In formula a and formula B, R is derived from a diisocyanate compound containing an aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon represented by R. Examples of the aliphatic diisocyanate compound containing the aliphatic hydrocarbon represented by R include 1, 2-ethylene diisocyanate, 1, 3-propylene diisocyanate, 1, 4-butane diisocyanate and 1, 6-hexane diisocyanate.

Examples of the diisocyanate compound containing the alicyclic hydrocarbon represented by R include 1, 4-cyclohexane diisocyanate and 4, 4-cyclohexane diisocyanate. Further, examples of the aromatic diisocyanate compound containing the aromatic hydrocarbon represented by R include 4,4' -diphenylmethane diisocyanate and toluene diisocyanate.

These diisocyanate compounds may be used alone or in combination of two or more thereof.

As the short-chain aliphatic, alicyclic or aromatic hydrocarbon represented by P' in formula B, for example, those having a molecular weight of less than 500 can be used. P 'is derived from a diol compound containing a short-chain aliphatic, alicyclic, or aromatic hydrocarbon represented by P'. Examples of the aliphatic diol compound containing a short-chain aliphatic hydrocarbon represented by P' include diols and polyalkylene glycols, specifically, ethylene glycol, propylene glycol, trimethylene glycol, 1, 4-butanediol, 1, 3-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, and 1, 10-decanediol.

Examples of the alicyclic diol compound containing the alicyclic hydrocarbon represented by P' include cyclopentane-1, 2-diol, cyclohexane-1, 3-diol, cyclohexane-1, 4-diol and cyclohexane-1, 4-dimethanol.

Further, examples of the aromatic diol compound containing an aromatic hydrocarbon represented by P ' include hydroquinone, resorcinol, chlorohydroquinone, bromohydroquinone, methylhydroquinone, phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone, 4' -dihydroxybiphenyl, 4' -dihydroxydiphenyl ether, 4' -dihydroxydiphenyl sulfide, 4' -dihydroxydiphenyl sulfone, 4' -dihydroxybenzophenone, 4' -dihydroxydiphenylmethane, bisphenol a, 1-bis (4-hydroxyphenyl) cyclohexane, 1, 2-bis (4-hydroxyphenoxy) ethane, 1, 4-dihydroxynaphthalene, and 2, 6-dihydroxynaphthalene.

These diol compounds may be used alone or in combination of two or more thereof.

From the viewpoint of melt moldability, the number average molecular weight of the polymer constituting the hard segment (i.e., polyurethane) is preferably 300 to 1,500. Meanwhile, the number average molecular weight of the polymer constituting the soft segment is preferably 500 to 20,000, more preferably 500 to 5,000, and particularly preferably 500 to 3,000, from the viewpoint of flexibility and thermal stability of the polyurethane-based thermoplastic elastomer. Further, from the viewpoint of moldability of the tire carcass, the mass ratio (x: y) of the hard segment (x) to the soft segment (y) is preferably 15:85 to 90:10, more preferably 30:70 to 90: 10.

The polyurethane-based thermoplastic elastomer can be synthesized by copolymerizing a polymer constituting a hard segment and a polymer constituting a soft segment by a known method. As the polyurethane-based thermoplastic elastomer, the thermoplastic polyurethane described in JP-A No. H05-331256 can be used.

As the polyurethane-based thermoplastic elastomer, specifically, a combination of a hard segment composed only of an aromatic diol and an aromatic diisocyanate and a soft segment composed only of a polycarbonate is preferable, and more specifically, at least one selected from the group consisting of a Toluene Diisocyanate (TDI)/polyester-based polyol copolymer, a TDI/polyether-based polyol copolymer, a TDI/caprolactone-based polyol copolymer, a TDI/polycarbonate-based polyol copolymer, a4, 4' -diphenylmethane diisocyanate (MDI)/polyester-based polyol copolymer, an MDI/polyether-based polyol copolymer, an MDI/caprolactone-based polyol copolymer, an MDI/polycarbonate-based polyol copolymer and an MDI + hydroquinone/polyhexamethylene carbonate copolymer is preferable. Among them, at least one selected from the group consisting of TDI/polyester polyol copolymers, TDI/polyether polyol copolymers, MDI/polyester polyol copolymers, MDI/polyether polyol copolymers and MDI + hydroquinone/polyhexamethylene carbonate copolymers is more preferable.

As commercially available products of the polyurethane-based thermoplastic elastomer, for example, there can be used the "ELASTOLLAN" series (e.g., ET680, ET880, ET690, and ET890, etc.) manufactured by BASF SE, the "KURAMILON U" series (e.g., 2000s, 3000s, 8000s, and 9000s, etc.) manufactured by Kuraray Co., Ltd, and the "MIRACTRAN" series (e.g., XN-2001, XN-2004, P390RSUP, P480RSUI, P26MRNAT, E490, E590, and P890, etc.) manufactured by Nippon Miractran Co., Ltd.

Olefin-based thermoplastic elastomer

Examples of the olefin-based thermoplastic elastomer include materials in which at least polyolefin constitutes a crystalline, high-melting-point hard segment and other polymers (for example, other polyolefin, or polyvinyl compound, or the like) constitute an amorphous, low-glass-transition-temperature soft segment. Examples of the polyolefin constituting the hard segment include polyethylene, polypropylene, isotactic polypropylene and polybutene.

Examples of the olefin-based thermoplastic elastomer include olefin- α -olefin random copolymers and olefin block copolymers, specifically, propylene block copolymers, ethylene-propylene copolymers, propylene-1-hexene copolymers, propylene-4-methyl-1-pentene copolymers, propylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-4-methyl-pentene copolymers, ethylene-1-butene copolymers, 1-butene-1-hexene copolymers, 1-butene-4-methyl-pentene, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl methacrylate copolymers, ethylene-butyl methacrylate copolymers, ethylene-propylene-1-pentene copolymers, propylene-4-methyl-pentene copolymers, propylene-1-hexene copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl methacrylate copolymers, ethylene-butyl methacrylate, Ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, propylene-methacrylic acid copolymer, propylene-methyl methacrylate copolymer, propylene-ethyl methacrylate copolymer, propylene-butyl methacrylate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, propylene-butyl acrylate copolymer, ethylene-vinyl acetate copolymer and propylene-vinyl acetate copolymer.

Wherein the olefinic thermoplastic elastomer is selected from the group consisting of propylene block copolymers, ethylene-propylene copolymers, propylene-1-hexene copolymers, propylene-4-methyl-1-pentene copolymers, propylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-4-methyl-pentene copolymers, ethylene-1-butene copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-ethyl methacrylate copolymers, ethylene-butyl methacrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers, propylene-methacrylic acid copolymers, propylene-ethylene-propylene copolymers, propylene-ethylene-propylene-copolymers, propylene-ethylene-1-pentene copolymers, propylene-ethylene-1-butene copolymers, ethylene-propylene-methacrylic acid copolymers, ethylene-, At least one of a propylene-methyl methacrylate copolymer, a propylene-ethyl methacrylate copolymer, a propylene-butyl methacrylate copolymer, a propylene-methyl acrylate copolymer, a propylene-ethyl acrylate copolymer, a propylene-butyl acrylate copolymer, an ethylene-vinyl acetate copolymer and a propylene-vinyl acetate copolymer is preferable; at least one selected from the group consisting of ethylene-propylene copolymer, propylene-1-butene copolymer, ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer and ethylene-butyl acrylate copolymer is more preferable.

Further, a combination of two or more kinds of olefin resins such as ethylene and propylene may also be used. The content of the olefin resin in the olefin-based thermoplastic elastomer is preferably 50 to 100% by mass.

The olefin-based thermoplastic elastomer preferably has a number average molecular weight of 5,000 to 10,000,000. When the number average molecular weight of the olefinic thermoplastic elastomer is 5,000 to 10,000,000, sufficient mechanical physical properties and excellent processability are imparted to the thermoplastic resin material. From the same viewpoint, the number average molecular weight of the olefinic thermoplastic elastomer is more preferably 7,000 to 1,000,000, and particularly preferably 10,000 to 1,000,000. Thereby, the mechanical physical properties and processability of the thermoplastic resin material can be further improved. Meanwhile, the number average molecular weight of the polymer constituting the soft segment is preferably 200 to 6,000 from the viewpoint of toughness and flexibility at low temperature. Further, from the viewpoint of moldability of the tire carcass, the mass ratio (x: y) of the hard segment (x) to the soft segment (y) is preferably 50:50 to 95:15, more preferably 50:50 to 90: 10.

The olefinic thermoplastic elastomer can be synthesized by copolymerization according to a known method.

As the olefinic thermoplastic elastomer, an acid-modified olefinic thermoplastic elastomer can also be used.

The term "acid-modified olefin-based thermoplastic elastomer" as used herein refers to an olefin-based thermoplastic elastomer to which an unsaturated compound having an acidic group such as a carboxylic acid group, a sulfuric acid group, or a phosphoric acid group is bonded.

For binding an unsaturated compound having an acidic group such as a carboxylic acid group, a sulfuric acid group, or a phosphoric acid group to an olefin-based thermoplastic elastomer, for example, an unsaturated binding site of an unsaturated carboxylic acid (for example, usually maleic anhydride) as an unsaturated compound having an acidic group is bound (for example, graft polymerized) to an olefin-based thermoplastic elastomer.

The unsaturated compound having an acidic group is preferably an unsaturated compound having a carboxylic acid group as a weak acid group from the viewpoint of suppressing deterioration of the olefin-based thermoplastic elastomer, and examples thereof include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, and maleic acid.

As commercially available products of olefinic thermoplastic elastomers, for example, "TAFMER" series manufactured by Mitsui Chemicals, Inc. (e.g., A0550S, A1050S, A4050S, A1070S, A4070S, A35070S, A1085S, A4085S, A7090, A70090, MH7007, MH7010, XM-7070, XM-7080, BL4000, BL2481, BL3110, BL3450, P-0275, P-0375, P-0775, P-0180, P-0280, P-0480, and P-0680) and "NUL" series manufactured by Du Pont-Mitsui polycals Co., Ltd., "NUL" series manufactured by Du 42C, AN4225C, AN 4236115, N C, N HC, LON 4201110, LOu 4209, LAC 465, VAL 469, VAL # 4248, VAL AC 469, VAL # 4248, NAC 469, NAC # 4248, NAC # and the like (e.g., Du-NAC 42359, NAC # 4248, NAC # cited as, 3427AC, and 3717AC, etc.), the "ACRYFT" series and the "EVATATE" series manufactured by Sumitomo Chemical co., ltd., the "ultrethe" series manufactured by Tosoh Corporation, and the "Prime TPO" series manufactured by Prime Polymer co., ltd. (e.g., E-2900H, F-3900H, E-2900, F-3900, J-5900, E-2910, F-3910, J-5910, E-2710, F-3710, J-5910, E-2740, F-3740, R110MP, R110E, T310E, and M142E, etc.).

Additives-

The resin material may also contain components other than the thermoplastic elastomer as needed. Examples of the components other than the thermoplastic elastomer include rubbers, thermoplastic resins, fillers (for example, silica, calcium carbonate, clay, and the like), anti-aging agents, oils, plasticizers, color formers, and weather-resistant agents.

It is known that the rolling performance of a tire and the injection moldability of a resin material are improved by incorporating a plasticizer into the resin material. However, the addition of the plasticizer in an excessively large amount may affect the adhesion of the resin material to other materials due to the occurrence of a blooming/bleeding phenomenon. Therefore, it is preferable to select a plasticizer highly compatible with the thermoplastic elastomer used, thereby ensuring formability and safety while suppressing the blooming/bleeding phenomenon and improving the rolling performance of the tire.

When the resin material contains a component other than the thermoplastic elastomer, the content of the thermoplastic elastomer in the resin material is preferably 50% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more, from the viewpoint of sufficiently obtaining the effect of the present disclosure.

Physical properties of the resin material

The crystallization temperature of the thermoplastic elastomer contained in the resin material is preferably in the range of 148 to 160 ℃, more preferably in the range of 150 to 155 ℃, and still more preferably in the range of 152 to 154 ℃. In the case where the crystallization temperature is within this range, the thickness La, the long period L, the degree of orientation f, the degree of crystallinity Xc, and the like of the amorphous portion can be easily controlled within the above ranges, and as a result, the durability of the tire, particularly, the crack resistance against impact can be easily improved.

the crystallization temperature of the thermoplastic elastomer is measured by Differential Scanning Calorimetry (DSC).

When the resin material contains two or more thermoplastic elastomers, the crystallization temperature of the thermoplastic elastomer having the highest content on a mass basis is preferably within the above range. More preferably, the resin material contains two or more kinds of thermoplastic elastomers including a thermoplastic elastomer having the highest content by mass and having a crystallization temperature within the above range, and still more preferably, all the thermoplastic elastomers contained in the resin material have a crystallization temperature within the above range.

The melting point of the resin material is typically from about 100 ℃ to about 350 ℃; however, from the viewpoint of durability and productivity of the tire, the melting point of the resin material is preferably from about 100 ℃ to about 250 ℃, more preferably from 120 ℃ to 250 ℃.

The tensile modulus of elasticity defined in JIS K7113:1995 of the resin material (i.e., the tire frame) itself is preferably 50MPa to 1,000MPa, more preferably 50MPa to 800MPa, and particularly preferably 50MPa to 700 MPa. When the tensile elastic modulus of the resin material is 50MPa to 1,000MPa, the tire can be effectively mounted to the rim while maintaining the shape of the tire frame.

The tensile strength defined in JIS K7113(1995) of the resin material itself (i.e., the tire frame) is usually about 15MPa to about 70MPa, preferably 17MPa to 60MPa, more preferably 20MPa to 55 MPa.

The tensile yield strength defined in JIS K7113(1995) of the resin material (i.e., the tire frame) itself is preferably 5MPa or more, more preferably 5MPa to 20MPa, and particularly preferably 5MPa to 17 MPa. When the tensile yield strength of the resin material is 5MPa or more, the tire can withstand deformation caused by a load applied to the tire during running or the like.

The tensile elongation at yield defined in JIS K7113(1995) of the resin material (i.e., the tire frame) itself is preferably 10% or more, more preferably 10% to 70%, and particularly preferably 15% to 60%. When the tensile yield elongation of the resin material is 10% or more, a large elastic region is provided, so that good rim mountability can be obtained.

The tensile elongation at break defined in JIS K7113(1995) of the resin material itself (i.e., the tire frame) is preferably 50% or more, more preferably 100% or more, particularly preferably 150% or more, and most preferably 200% or more. When the tensile elongation at break of the resin material is 50% or more, good rim mountability can be obtained, and the tire can be made less likely to break upon impact.

The deflection temperature under load (condition: under a load of 0.45 MPa) defined in ISO 75-2 or ASTM D648 of the resin material (i.e., the tire frame) itself is preferably 50 ℃ or more, more preferably 50 to 150 ℃, and particularly preferably 50 to 130 ℃. When the load deflection temperature of the resin material is 50 ℃ or higher, deformation of the tire frame can be suppressed even when vulcanization is performed in the manufacture of the tire.

The vicat softening temperature (method a) defined in JIS K7206(2016) of the resin material itself (i.e., the tire frame) is preferably 130 ℃ or more, more preferably 130 to 250 ℃, and still more preferably 130 to 220 ℃. In the case where the softening temperature of the thermoplastic resin material (method a) is 130 ℃ or more, softening and deformation of the tire in the use environment can be suppressed. Further, even when vulcanization is performed for joining in the manufacture of a tire, deformation of the tire frame can be suppressed.

[ constitution of members other than the tire frame body in the tire ]

The tire according to the present embodiment may include members other than the tire frame as needed. For example, the tire according to the present embodiment may include a reinforcing member disposed on the outer periphery or the like of the tire frame for the purpose of reinforcing the tire frame.

Examples of the reinforcing member include a cord member configured to include a metal member such as a steel cord, and a cord member coated with a coating resin material may also be used.

The resin in the coating resin material for the reinforcing member is, for example, a thermosetting resin, a thermoplastic elastomer, or the like.

Examples of the thermosetting resin include phenol resin, urea resin, melamine resin, epoxy resin, polyamide resin, and polyester resin.

Examples of the thermoplastic resin include polyurethane resins, olefin resins, vinyl chloride resins, polyamide resins, and polyester resins.

Examples of the thermoplastic elastomer include polyester-based thermoplastic elastomer (TPC), polyamide-based thermoplastic elastomer (TPA), polyolefin-based thermoplastic elastomer (TPO), polystyrene-based thermoplastic elastomer (TPS), polyurethane-based thermoplastic elastomer (TPU), thermoplastic rubber crosslinked body (TPV), and other thermoplastic elastomer (TPZ), all of which are defined in JIS K6418: 2007. Among the resins of the above examples, a thermoplastic elastomer is preferably used in view of elasticity required during running, moldability in production, and the like.

Further, the coating resin material of the reinforcing member preferably contains the same kind of thermoplastic elastomer as that contained in the resin material constituting the tire frame.

Further, a reinforcing member having a structure in which a cord member is coated with a coating resin material via an adhesive (i.e., an adhesive layer) may also be used, and the reinforcing member may be disposed on the tire frame. In this case, it is preferable that the mahalanobis hardness (Martens hardness) (d1) of the tire frame, the mahalanobis hardness (d2) of the coating resin material, and the mahalanobis hardness (d3) of the adhesive layer satisfy the relationship of d1 ≦ d2< d 3. By setting the mahalanobis hardness of the coating resin material to be less than the mahalanobis hardness of the adhesive layer and equal to or greater than the mahalanobis hardness of the tire frame, the difference in rigidity between the resin material constituting the tire frame and the cord member is effectively mitigated. As a result, the durability of the tire can be further improved.

[ constitution of tire ]

An embodiment of a tire according to the present embodiment will now be described with reference to the drawings. It is to be noted herein that members having the same functions and effects may be designated by the same reference numerals throughout the drawings, and in this case, the description of the reference numerals may be omitted.

Fig. 1A is a perspective view illustrating a section of a portion of a tire 10 according to a first embodiment. Fig. 1B is a sectional view of a bead portion mounted to a rim of the tire 10 according to the first embodiment. As shown in fig. 1A, the tire 10 has substantially the same sectional shape as a conventional and commonly used rubber pneumatic tire. As shown in fig. 1A, the tire 10 includes a casing 17 composed of: a pair of bead portions 12 that are in contact with each of a bead seat 21 and a rim flange 22 of a rim 20 shown in fig. 1B; a sidewall portion 14 extending outward in the tire radial direction from each bead portion 12; and a crown portion 16 (i.e., an outer peripheral portion) that connects a tire radial direction outer end of one sidewall portion 14 and a tire radial direction outer end of the other sidewall portion 14.

The casing 17 corresponds to a tire frame, and is formed of the above-described resin material. In the first embodiment, the casing 17 is entirely formed of the above-described resin material; however, the present disclosure is not limited to this configuration. In the same manner as a conventional and commonly used rubber-made pneumatic tire, different resin materials may be used for each portion of the casing 17 (for example, the sidewall portion 14, the crown portion 16, and the bead portion 12). Further, reinforcing materials (for example, fibers, cords, nonwoven fabrics, woven fabrics, or the like made of a polymer material or a metal) may be embedded in each portion of the casing 17 to reinforce each portion of the casing 17.

The casing 17 of the first embodiment is formed by: two half casing bodies (i.e., tire frame pieces) each having a shape in a state where the casing 17 is equally divided in the tread width in the circumferential direction are prepared, and then the two half casing bodies are joined together at the tire equatorial plane. The casing 17 is not limited to being formed by joining two members (i.e., two casing halves), and may be formed by joining three or more members.

The carcass halves can be produced, for example, by vacuum forming, pressure forming, injection forming, or melt casting. Therefore, the manufacturing process can be greatly simplified and the molding time can be shortened as compared with the conventional case in which the casing is molded from rubber, because vulcanization is not necessarily performed.

In the first embodiment, in the same manner as in a conventional and commonly used pneumatic tire, a ring-shaped bead core 18 is embedded in the bead portion 12 shown in fig. 1B. In the first embodiment, steel cords are used as the bead cores 18; however, an organic fiber cord, a resin-coated organic fiber cord, a hard resin cord, or the like may also be used. It is to be noted here that the bead core 18 may be omitted as long as the rigidity of the bead portion 12 is ensured and the bead portion 12 is well fitted to the rim 20.

In the first embodiment, a ring-shaped seal layer 24 composed of a material having more excellent sealability than the resin material constituting the casing 17 is formed on the portion of each bead portion 12 that contacts the rim 20 or at least on the portion of each bead portion 12 that contacts the rim flange 22 of the rim 20. The seal layer 24 may also be formed in a portion in which each bead portion 12 of the casing 17 is in contact with the bead seat 21. The seal layer 24 may be omitted as long as the resin material constituting the tire case 17 alone can ensure sealability with the rim 20. Examples of the material having more excellent sealing property than the resin material constituting the casing 17 include: a material softer than the resin material constituting the casing 17, such as rubber; and thermoplastic resins and thermoplastic elastomers that are softer than the resin material.

As shown in fig. 1A, in the crown portion 16, a reinforcing cord 26 having a higher rigidity than the resin material constituting the casing 17 is wound in the circumferential direction of the casing 17. In a sectional view taken along the axial direction of the case 17, the reinforcing cord 26 is spirally wound with at least a portion thereof buried in the crown portion 16, and a reinforcing cord layer 28 is formed. On the tire radial direction outer circumferential side of the reinforcing cord layer 28, a tread 30 made of a material having more excellent wear resistance than the resin material constituting the carcass 17, for example, rubber, is arranged.

In the first embodiment, as shown in fig. 2, the reinforcing cord 26 is in a state in which a metal member 26A such as a steel cord is covered with a covering resin material 27 (i.e., a covered cord member). In the first embodiment, the same resin material as that constituting the casing 17 is used as the covering resin material 27; however, other thermoplastic resins or thermoplastic elastomers may also be used. The reinforcing cords 26 and crown portion 16 are joined by fusion, adhesion using an adhesive, or the like at those portions where they contact each other. The reinforcing cord 26 may be a steel cord or the like which is not coated with the coating resin material 27.

The elastic modulus of the coating resin material 27 is preferably set in a range of 0.1 to 10 times the elastic modulus of the resin material constituting the casing 17. When the modulus of elasticity of the coating resin material 27 is 10 times or less of the modulus of elasticity of the resin material constituting the tire case 17, the crown portion is prevented from being excessively hard, so that the tire can be easily mounted to the rim. When the elastic modulus of the coating resin material 27 is 0.1 times or more the elastic modulus of the resin material constituting the carcass 17, since the resin constituting the reinforcing cord layer 28 is not excessively soft, excellent in-belt-in-plane shear rigidity is obtained, and the cornering force is improved.

In the first embodiment, as shown in fig. 2, the reinforcing cord 26 has a substantially trapezoidal sectional shape. In the following description, an upper surface (i.e., a surface on the outer side in the tire radial direction) of the reinforcing cord 26 is denoted by reference numeral 26U, and a lower surface (i.e., a surface on the inner side in the tire radial direction) of the reinforcing cord 26 is denoted by reference numeral 26D. Further, in the first embodiment, the reinforcing cord 26 is configured to have a substantially trapezoidal sectional shape; however, the present disclosure is not limited to this configuration. The reinforcing cord 26 may take any shape other than a shape in which the cross-sectional width increases from the lower surface 26D side (i.e., the tire radial direction inner side) to the upper surface 26U side (i.e., the tire radial direction outer side).

As shown in fig. 2, since the reinforcing cords 26 are arranged at intervals in the circumferential direction, gaps 28A are formed between the adjacent reinforcing cords 26. Therefore, the outer peripheral surface of the reinforcing cord layer 28 is shaped to have irregularities, and the outer peripheral surface 17S of the casing 17 having the outer peripheral portion constituted by the reinforcing cord layer 28 is also shaped to have irregularities.

On the outer peripheral surface 17S (including the above-described unevenness) of the casing 17, the unevenness 96 that is finely roughened is formed, and the cushion rubber 29 is bonded thereto via a bonding agent. The cushion rubber 29 flows so as to fill the roughened irregularities 96 at the contact surface with the reinforcing cord 26.

The above-described tread 30 is joined to the cushion rubber 29 (i.e., on the tire outer circumferential surface side). On the surface of the tread 30 that contacts the road surface, a tread pattern (not shown) composed of a plurality of grooves is formed in the same manner as in a conventional rubber-made pneumatic tire.

[ method for producing tire ]

Next, the method for manufacturing a tire of the present embodiment will be described using the above-described method for manufacturing a tire according to the first embodiment as an example.

(step of body Forming)

first, the half body is formed by injection molding or the like (molding step). For example, by adjusting the temperature of the resin material in this molding step, such as the cylinder temperature or the mold temperature in the case of injection molding, the thickness La, the long period L, the orientation degree f, the crystallinity Xc, and the like of the amorphous portion of the thermoplastic elastomer contained in the casing can be controlled within the respective ranges described above.

The barrel temperature is preferably in the range of 240 ℃ to 290 ℃, more preferably in the range of 240 ℃ to 260 ℃, still more preferably in the range of 240 ℃ to 245 ℃.

Further, the mold temperature is preferably in the range of 50 to 110 ℃, more preferably in the range of 50 to 80 ℃, and still more preferably in the range of 50 to 55 ℃.

The control of the thickness La, the long period L, the degree of orientation f, the degree of crystallinity Xc, and the like of the amorphous portion of the thermoplastic elastomer is considered to be influenced by the adjustment of the cooling rate and the cooling time of the resin material in the molding step. Therefore, the cooling rate is preferably in the range of 140 ℃/sec to 240 ℃/sec, more preferably in the range of 140 ℃/sec to 230 ℃/sec. The cooling time (i.e., the time required to cool the resin material to the mold temperature) is preferably in the range of 1 second to 5 seconds, and more preferably in the range of 1 second to 1.5 seconds.

Next, the toroidal casing halves obtained in the forming step are aligned facing each other and joined at the tire equatorial plane to form a casing (joining step). The casing is not limited to being formed by joining two members, and may be formed by joining three or more members.

The engagement will now be explained. First, the carcass halves, each supported by a thin metal support ring, are aligned facing each other. Subsequently, a joining mold is set in contact with the outer peripheral surfaces of the butted portions of the carcass halves. The joining mold is configured in such a manner that the periphery of the joined portion (i.e., butted portion) of the case half bodies is pressurized at a predetermined pressure. Then, the periphery of the joined portion of the case half bodies is pressed at a temperature not lower than the melting point of the resin material constituting the case, whereby the joined portion is melted and the case half bodies are fusion-integrated, resulting in formation of the case 17.

the thickness La, the long period L, the degree of orientation f, the degree of crystallinity Xc, and the like of the amorphous portion of the carcass 17 can also be controlled within the above-described respective ranges by, for example, adjusting the temperature of the resin material such as the temperature of the joining mold in this joining step.

In the manufacturing method of the first embodiment, the joint portions of the case half bodies are heated using a joint mold; however, the present disclosure is not limited to this mode. The carcass halves may be joined together by: for example, the joint portion is heated using a high-frequency heater or the like disposed separately; or softening or melting the joint portion by hot air, irradiation with infrared rays, or the like in advance, and then applying pressure to the joint portion using a joining mold.

(reinforcing cord member winding step)

Next, a step of winding the reinforcing cord 26 around the casing 17 will be described with reference to fig. 3. Fig. 3 is a view for explaining an operation of burying the reinforcing cord 26 in the crown portion of the carcass 17 using the cord heating device and the roller.

In fig. 3, the cord feeding apparatus 56 includes: a reel 58 on which the reinforcing cord 26 is wound; a cord heating device 59 disposed on the downstream side of the reel 58 in the cord conveying direction; a first roller 60 disposed on the downstream side in the conveying direction of the reinforcing cord 26; a first cylinder device 62 that moves the first roller 60 in a direction toward or away from the outer peripheral surface of the tire; a second roller 64 disposed on the downstream side of the first roller 60 in the conveying direction of the reinforcing cord 26; and a second cylinder device 66 that moves the second roller 64 in a direction toward or away from the outer peripheral surface of the tire. The second roller 64 may be used as a cooling roller made of metal.

In the first embodiment, the surface of the first roller 60 or the surface of the second roller 64 is treated (for example, coated with a fluororesin) to suppress adhesion of the melted or softened coating resin material 27. However, the present disclosure is not limited to this mode, and the roller itself may be formed of a material to which the coating resin material 27 is difficult to adhere. In the first embodiment, the cord feeding apparatus 56 has two rollers of the first roller 60 and the second roller 64; however, the present disclosure is not limited to this mode, and the cord feeding apparatus 56 may have only one of these rollers.

The cord heating device 59 includes a heater 70 and a fan 72 that generate a flow of hot air. The cord heating device 59 further includes: a heating box 74 in which the reinforcing cord 26 passes through the inner space to which the hot air flow is supplied; and a discharge port 76 that discharges the reinforcing cord 26 thus heated.

In this step, first, the temperature of the heater 70 of the cord heating device 59 is raised, and the ambient air heated by the heater 70 is conveyed to the heating box 74 using the air flow generated by the rotation of the fan 72. Then, the reinforcing cord 26 drawn out from the reel 58 is transferred into the heating box 74 whose inner space has been heated by the flow of hot air, thereby heating the reinforcing cord 26. The heating temperature is set so that the coating resin material 27 of the reinforcing cord 26 is in a molten or softened state.

The thus heated reinforcing cord 26 passes through the discharge port 76 and is spirally wound under constant tension on the outer peripheral surface of the crown portion 16 of the casing 17 rotating in the direction of the arrow R shown in fig. 3. In this process, the lower surface 26D of the reinforcing cord 26 is brought into contact with the outer peripheral surface of the crown portion 16. The coating resin material 27 in a state of being melted or softened by heating is spread on the outer circumferential surface of the crown portion 16, whereby the reinforcing cord 26 is melt-bonded to the outer circumferential surface of the crown portion 16. As a result, the joining strength between the crown portion 16 and the reinforcing cord 26 is improved.

In the first embodiment, the reinforcing cord 26 is joined to the outer peripheral surface of the crown portion 16 in the above manner; however, the present disclosure is not limited to this mode, and joining may also be performed by other methods. For example, the engagement may be made in such a manner that the reinforcing cords 26 are partially or entirely embedded in the crown portion 16.

(roughening treatment step)

Subsequently, using a blasting apparatus not shown in the drawings, blasting abrasives are ejected at a high speed toward the outer circumferential surface 17S of the casing 17 while rotating the casing 17. The shot blasting abrasive collides with the outer peripheral surface 17S, thereby forming fine roughened irregularities 96 having an arithmetic average roughness (Ra) of 0.05mm or more on the outer peripheral surface 17S. By forming the minutely roughened irregularities 96 on the outer peripheral surface 17S of the casing 17 in this way, the outer peripheral surface 17S is made hydrophilic so as to improve wettability with a cement described below.

(laminating step)

Next, a cement for bonding the cushion rubber 29 is applied to the outer circumferential surface 17S of the casing 17 thus roughened. The adhesive is not particularly limited, and for example, a triazine thiol adhesive, a chlorinated rubber adhesive, a phenol resin adhesive, an isocyanate adhesive, a halogenated rubber adhesive, or a rubber adhesive can be used. The bonding agent is preferably one that reacts at a temperature at which the cushion rubber 29 can be vulcanized (for example, 90 ℃ C. to 140 ℃ C.).

Then, the cushion rubber 29 in an unvulcanized state is wound around the outer circumferential surface 17S to which the bonding agent has been applied for one turn, and the bonding agent such as a rubber adhesive composition is further applied to the cushion rubber 29, after which the tread rubber 30A in a vulcanized or semi-vulcanized state is wound around the cushion rubber 29 to which the bonding agent has been applied for one turn, thereby obtaining a green tire casing.

(vulcanization step)

Next, the green tire casing thus obtained is vulcanized in a vulcanizing tank or a mold. In this process, the unvulcanized cushion rubber 29 flows into the roughened irregularities 96 that have been formed on the outer peripheral surface 17S of the tire case 17 by the roughening treatment. Once vulcanization is completed, the anchoring effect is exhibited by the cushion rubber 29 that has flowed into the roughened unevenness 96, and the joining strength between the casing 17 and the cushion rubber 29 is thereby improved. In other words, the joint strength between the casing 17 and the tread 30 is improved by the cushion rubber 29.

After that, the seal layer 24 is bonded to each bead portion 12 of the casing 17 using an adhesive or the like, thereby completing the tire 10.

Embodiments of the present disclosure have been described so far taking the first embodiment as an example; however, these embodiments are merely examples, and the present disclosure may be implemented with various modifications within a scope not departing from the spirit of the present disclosure. It goes without saying that the scope of the present invention is not limited to these embodiments. For details of embodiments applicable to the present disclosure, reference may be made to, for example, JP- ｃA No. 2012-46025.

As described above, according to the present disclosure, the following tire is provided.

<1> according to a first aspect of the present disclosure, there is provided a tire including a tire frame formed of a resin material containing a thermoplastic elastomer, wherein a thickness La of an amorphous portion of the thermoplastic elastomer measured by a small-angle X-ray scattering method is in a range of 12.3nm to 13.9 nm.

<2> according to a second aspect of the present disclosure, there is provided the tire according to the first aspect, wherein the long period L of the thermoplastic elastomer measured by a small-angle X-ray scattering method is in a range of 15.6nm to 17.1 nm.

<3> according to a third aspect of the present disclosure, there is provided the tire according to the first or second aspect, wherein the thermoplastic elastomer has an orientation degree f in the range of-0.08 to 0.08 as measured by a small-angle X-ray scattering method.

<4> according to a fourth aspect of the present disclosure, there is provided the tire according to any one of the first to third aspects, wherein the thermoplastic elastomer is a polyester-based thermoplastic elastomer.