JP2010116027A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire enhancing run-flat durability without impairing rolling resistance and riding comfortability during normal travel. <P>SOLUTION: The pneumatic tire is equipped with a bead core, a carcass ply, a tread rubber layer, an inner liner, a side reinforcing layer and a bead filler. Reinforcing fiber cords constituting the carcass ply are formed of cords including at least 50 mass% of polyketone fibers subjected to drying hardening treatment after coating of RFL adhesive and satisfy (1) the tensile strength of cords in the drying process and heat treatment process is 2.9-49.0 N per one cord, (2) the drying treatment temperature in the drying process is 100-200°C, and (3) when the hardening treatment temperature in the heat treatment process is Tm (°C) and the hardening treatment time is s (sec), Tm/s is 1.1-8.7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pneumatic tire. More specifically, the present invention applies to a carcass ply a reinforcing fiber cord including a polyketone fiber formed by adhering and impregnating an RFL adhesive (resorcin / formaldehyde resin-rubber latex adhesive) under specific drying and vulcanizing conditions. And preferably, by using a rubber composition having a specific property for at least one of the tire members, in particular, the side reinforcing layer and / or the bead filler, the rolling resistance and riding comfort during normal running are impaired. The present invention relates to a pneumatic tire with improved runfoot durability.

2. Description of the Related Art Conventionally, in a pneumatic tire, particularly a run flat tire, a side reinforcing layer made of a rubber composition alone or a composite of a rubber composition and a fiber is provided to improve the rigidity of a sidewall portion. (For example, see Patent Document 1)
Pneumatic tires run when the internal pressure of the tire (hereinafter referred to as internal pressure) drops due to puncture, etc., so-called run-flat running state, the deformation of the tire sidewall and bead filler increases, and heat is generated. In some cases, the temperature reaches 200 ° C. or higher. In such a state, even in a pneumatic tire having a side reinforcing layer, the side reinforcing layer and the bead filler exceed the fracture limit, leading to a tire failure.

As means for earning time until such failure, there are those that increase the volume of rubber, such as increasing the maximum thickness of the side reinforcing layer and the bead filler to be disposed, but if such a method is taken Undesirable situations such as deterioration of ride comfort during normal driving, an increase in weight, and an increase in noise level occur.
If the volume of the side reinforcing layer and the bead filler to be disposed is reduced in order to avoid the above-mentioned situation, for example, deterioration of the ride comfort, the load at the time of run flat cannot be supported. Deformation becomes very large, leading to an increase in heat generation of the rubber composition, and as a result, the tire has a problem of causing failure earlier.
Similarly, when the rubber used is made to be less elastic by changing the compounding material, the rubber composition is not able to support the load during run-flat, and the deformation of the sidewall portion of the tire becomes very large. As a result, the tires are likely to break down earlier as a result.

Further, cellulose fibers (rayon fibers) having a higher Young's modulus than polyester (PET) fibers are mainly used in conventional side-reinforced run-flat tire carcass plies mainly at room temperature and at high temperatures.
However, with the elastic modulus of conventional rayon fibers, the tire flexure during run-flat is large, and at high temperatures, the flexure of the tire increases due to reduced rigidity of the carcass ply. The problem was that the run-flat durability distance was short.
Further, if the reinforcing rubber layer is thickened or the side portion and the shoulder portion are reinforced, the tire longitudinal spring constant at the time of internal pressure is increased as the weight increases, and the riding comfort during normal running is impaired.

On the other hand, Patent Document 2 proposes that a rubber composition containing various modified conjugated diene-aromatic vinyl copolymers and a heat resistance improver is used for the side reinforcing layer and the bead filler.
Furthermore, Patent Document 3 proposes that a rubber composition containing a specific conjugated diene polymer and a phenol resin is used for the side reinforcing layer and the bead filler.
These are intended to increase the elastic modulus of the rubber composition used for the side reinforcing layer and bead filler, and to suppress a decrease in the elastic modulus at high temperatures, and greatly improve the run-flat durability. However, the rolling resistance during normal running is significantly deteriorated.

JP 11-310019 A WO02 / 02356 brochure JP 2004-74960 A

  The present invention has been made under such circumstances, and an object thereof is to provide a pneumatic tire with improved run-flat durability without impairing rolling resistance and riding comfort during normal driving. It is.

  As a result of intensive studies to achieve the above object, the present inventors have made 50 mass% of polyketone fiber formed by adhering and impregnating resorcin / formaldehyde resin-rubber latex adhesive under specific drying and heating conditions. By applying the reinforcing fiber cord including the above to the carcass ply, and preferably using a rubber composition having a specific property for at least one of the tire members, particularly for the side reinforcing layer and / or the bead filler, the object is achieved. I found that it can be achieved. The present invention has been completed based on such findings.

That is, the present invention
[1] A pneumatic tire comprising a bead core, a carcass ply, a tread rubber layer, an inner liner, a side reinforcing layer, and a bead filler, wherein the reinforcing fiber cord constituting the carcass ply is bonded to resorcin / formaldehyde resin-rubber latex After applying the agent, the cord is a cord containing at least 50% by mass of a polyketone fiber, which is dried and cured through a drying step and a heat treatment step, and the following condition (1) The cord tension in the drying step and the heat treatment step is one. 2.9-49.0N per hit,
(2) The drying process temperature in the said drying process is 100-200 degreeC,
(3) When the curing temperature in the heat treatment step is Tm (° C.) and the curing time is s (seconds), Tm / s is 1.1 to 8.7,
Pneumatic tire, characterized by satisfying

[2] The amount of the adhesive attached to the reinforcing fiber cord formed by applying a resorcinol / formaldehyde resin-rubber latex adhesive and then dried and cured is 1.5 to 9.0 with respect to the mass of the cord before the treatment. The pneumatic tire according to [1], wherein the pneumatic tire is% by mass,
[3] The pneumatic tire according to [1] or [2], wherein the reinforcing fiber cord constituting the carcass ply has a twist coefficient N represented by the following formula (1) satisfying a relationship of the following formula (2): ,
N = n × (0.125D / ρ) ^1/2 × 10 ⁻³ (1)
0.34 ≦ N (2)
[In the formula, n represents the number of upper twists (times / 10 cm), D represents the total display decitex, and ρ represents the density (g / cm ³ ) of the fiber containing at least 50% by mass of the polyketone fiber. ]
[4] The twist coefficient N is the following formula (2-a)
0.6 ≦ N ≦ 0.9 (2-a)
The pneumatic tire according to [3], which satisfies the relationship:
[5] The pneumatic tire according to any one of [1] to [4], wherein the number of driven reinforcing fiber cords constituting the carcass ply is 30 to 60/50 mm,
[6] The pneumatic tire according to any one of [1] to [5], wherein the reinforcing fiber cord constituting the carcass ply is formed by twisting a filament bundle having a fineness of 500 to 2000 dtex.
[7] The polyketone constituting the polyketone fiber is represented by the following general formula (3):

[In formula, A shows the residue derived from the unsaturated compound superposed | polymerized by the unsaturated bond, and may be same or different in a repeating unit. ]
The pneumatic tire according to any one of the above [1] to [6], having a repeating unit represented by:
[8] The pneumatic tire according to the above [7], wherein A in the general formula (3) is an ethylene group,
[9] (A) The rubber component and 100 parts by mass of (B) the carbon black contains 55 parts by mass or more, and the physical properties of vulcanized rubber have an elastic modulus at 100% elongation (M100) of 10 MPa or more, and The air according to any one of [1] to [8], wherein a rubber composition having a tangent loss (tan δ) of Σ value at 28 to 150 ° C. of 6.0 or less is used for at least one of the tire members. In the above tire [10], in the rubber composition [10], (B) the carbon black is at least one selected from FEF grade, FF grade, HAF grade, ISAF grade and SAF grade Pneumatic tires as described,
[11] The pneumatic tire according to [10], wherein (B) carbon black is an FEF grade grade,
[12] The pneumatic tire according to any one of [9] to [11], wherein in the rubber composition, (A) the rubber component includes an amine-modified conjugated diene polymer.
[13] The pneumatic tire according to [12], wherein the amine-modified conjugated diene polymer is a protic amine-modified conjugated diene polymer,

[14] The pneumatic tire according to the above [12] or [13], wherein the amine-modified conjugated diene polymer is a primary amine-modified conjugated diene polymer.
[15] The pneumatic tire according to the above [14], wherein the primary amine-modified conjugated diene polymer is obtained by reacting a protected primary amine compound with an active terminal of the conjugated diene polymer.
[16] The above conjugated diene polymer is obtained by anionic polymerization of a conjugated diene compound alone or a conjugated diene compound and an aromatic vinyl compound in an organic solvent using an organic alkali metal compound as an initiator. [15] The pneumatic tire according to
[17] The pneumatic tire according to [16], wherein the conjugated diene polymer is polybutadiene,
[18] The pneumatic tire according to any one of [15] to [17], wherein the protected primary amine compound is N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane,
[19] The pneumatic tire according to any one of [9] to [18], wherein the rubber composition is used as a side reinforcing layer.
[20] The pneumatic tire according to any one of [9] to [18], wherein the rubber composition is used as a bead filler, and [21] the rubber composition as a side reinforcing layer and a bead filler. The pneumatic tire according to any one of the above [9] to [18],
Is to provide.

The pneumatic tire of the present invention has the following effects.
(1) A cord containing 50% by mass or more of polyketone fiber is adhered and impregnated with a resorcin / formaldehyde resin-rubber latex adhesive (hereinafter sometimes referred to as RFL adhesive) under specific drying and heating conditions. By applying this to the carcass ply, a pneumatic tire with improved run-flat durability can be obtained without impairing rolling resistance and riding comfort during normal driving.
(2) Furthermore, by using a rubber composition having specific vulcanized rubber properties as a reinforcing rubber for at least one of the tire members, particularly the side reinforcing layer and / or the bead filler, the effect of the above (1) can be obtained. A more improved pneumatic tire can be obtained.

  The pneumatic tire of the present invention comprises a bead core, a carcass ply, a tread rubber layer, an inner liner, a side reinforcing layer, and a bead filler, and as a reinforcing fiber cord constituting the carcass ply, a drying step after applying an RFL adhesive And a cord containing at least 50% by mass of polyketone fiber, which is dried and cured through a heat treatment step.

[Reinforcing fiber cord]
In the pneumatic tire of the present invention, an RFL adhesive is applied to a cord containing at least 50% by mass of polyketone fiber as a reinforcing fiber cord constituting a carcass ply, and then dried and cured through a drying step and a heat treatment step. Use things.
(Polyketone fiber)
In the present invention, as the polyketone constituting the polyketone fiber, the following general formula (3)

[In formula, A shows the residue derived from the unsaturated compound superposed | polymerized by the unsaturated bond, and may be same or different in a repeating unit. And those having a repeating unit represented by the formula:
Among these polyketones, a polyketone in which 97 mol% or more of repeating units is 1-oxotrimethylene [—CH ₂ —CH ₂ —CO—] is preferable, and a polyketone in which 99 mol% or more is 1-oxo trimethylene is more preferable. Most preferred are polyketones in which 100 mol% is 1-oxotrimethylene. As the proportion of 1-oxotrimethylene in the repeating unit is higher, the regularity of the molecular chain is improved, and a fiber with high crystallinity and high degree of orientation is obtained.

  In the above polyketone, the ketones may be partially bonded to each other and the unsaturated compound-derived parts may be bonded to each other, but the ratio of the unsaturated compound-derived residues and ketone groups alternately arranged is 90% by mass or more. It is preferable that it is 97 mass% or more, and it is most preferable that it is 100 mass%.

  In the above formula (3), the unsaturated compound constituting A is most preferably ethylene, but propylene, butene, pentene, cyclopentene, hexene, cyclohexene, heptene, octene, nonene, decene, dodecene, styrene, acetylene. , Unsaturated hydrocarbons other than ethylene such as allene, methyl acrylate, vinyl acetate, acrylamide, hydroxyethyl methacrylate, undecenoic acid, undecenol, 6-chlorohexene, N-vinylpyrrolidone, diester of styrylphosphonic acid, sodium styrenesulfonate Further, it may be a compound containing an unsaturated bond such as sodium allyl sulfonate and vinyl chloride.

  As a method for fiberizing this polyketone, (1) after spinning an undrawn yarn, performing multistage hot drawing, and drawing at a specific temperature and magnification in the final drawing step of the multistage hot drawing, (2 ) A method is preferred in which after unspun yarns are spun, hot drawing is performed, and after the hot drawing, the fibers are rapidly cooled while high tension is applied. A desired filament suitable for production of the polyketone fiber cord can be obtained by fiberizing the polyketone by the method (1) or (2).

  Here, the spinning method of the unstretched yarn of the polyketone is not particularly limited, and a conventionally known method can be employed. Specifically, JP-A-2-112413, JP-A-4-228613, Wet spinning method using an organic solvent such as hexafluorooisopropanol and m-cresol as described in JP-T-505344, WO99 / 18143, WO00 / 09611, JP2001-164422, A wet spinning method using an aqueous solution of zinc salt, calcium salt, thiocyanate, iron salt or the like as described in JP-A Nos. 2004-218189 and 2004-285221 is preferable.

Further, as a stretching method of the obtained unstretched yarn, a hot stretching method in which the unstretched yarn is heated and stretched to a temperature higher than the glass transition temperature of the unstretched yarn is preferable. The method (2) may be performed in one stage, but it is preferably performed in multiple stages.
There is no restriction | limiting in particular as this heat drawing method, For example, the method etc. which run a thread | yarn on a heating roll or a heating plate are employable. Here, the heat stretching temperature is preferably in the range of 110 ° C. to (melting point of polyketone), and the total stretching ratio is preferably 10 times or more.

The polyketone fiber preferably has a crystal structure with a crystallinity of 50 to 90% and a crystal orientation of 95% or more. When the degree of crystallinity is less than 50%, the fiber structure is not sufficiently formed and sufficient strength cannot be obtained, and the shrinkage property and dimensional stability during heating may be unstable. For this reason, the crystallinity is preferably 50 to 90%, more preferably 60 to 85%.
The cord can be made by twisting filament bundles. There is no restriction | limiting in particular about the number of filament bundles twisted, The code | cord | chord which twisted two or three filament bundles normally is used.

In the present invention, examples of the cord used for the production of the reinforcing fiber cord constituting the carcass ply include (a) a cord made only of a polyketone fiber, and (b) a polyketone fiber and a fiber other than the polyketone fiber mixed or twisted. A code etc. are mentioned. It is necessary that at least 50% by mass of the polyketone fiber is contained in one cord. Polyketone fibers are used in the cord at least 50% by weight, preferably at least 75% by weight, more preferably at least 90% by weight, and most preferably 100% by weight.
By setting the ratio of the polyketone fiber in the cord within the above range, excellent heat shrinkability, strength, dimensional stability, heat resistance, adhesion to rubber, and the like of the cord can be obtained.

  The fibers other than polyketone fibers are not particularly limited as long as the ratio is 50% by mass or less, and known fibers such as polyamide fibers, polyester fibers, rayon fibers, and aramid fibers are used depending on the application and purpose. When the amount of fibers other than polyketone fibers exceeds 50% by mass, for example, in the case of cords made of polyester fibers or polyamide fibers, strength and dimensional stability are impaired, and in the case of warp yarns made of rayon fibers, the strength is greatly impaired. In the case of warp made of aramid fibers, the adhesiveness with rubber is greatly impaired.

(Production of reinforcing fiber cord)
In the pneumatic tire of the present invention, the reinforcing fiber cord constituting the carcass ply is applied with the RFL adhesive on the cord containing at least 50% by mass of the polyketone fiber obtained as described above, followed by a drying step and a heat treatment step. In this case, the cord tension in the drying step and the heat treatment step is 2.9 to 49.0 N per one of the following conditions (1):
(2) The drying process temperature in the said drying process is 100-200 degreeC,
(3) When the curing temperature in the heat treatment step is Tm (° C.) and the curing time is s (seconds), Tm / s is 1.1 to 8.7,
It is necessary to satisfy.

If the cord tension in the drying step and the heat treatment step is less than 2.9 N per yarn, the yarn is not sufficiently modified in the heat treatment step, whereas if it exceeds 49.0 N, the yarn is often broken. , Tire molding becomes difficult. The cord tension is preferably 9.8 to 39.2 N per cord from the viewpoint of sufficiently performing heat treatment and preventing the yarn from being cut.
In addition, when the drying process temperature in the drying step is less than 100 ° C., moisture in the RFL adhesive is difficult to evaporate and drying becomes insufficient. On the other hand, when it exceeds 200 ° C., evaporation of moisture in the RFL adhesive occurs at a stretch. As a result, there is a problem that the adhesive is not uniformly adhered and impregnated on the cord. This drying treatment temperature is preferably 120 to 190 ° C., more preferably 140 to 180 ° C. from the viewpoints of drying properties and homogeneous adhesion impregnation of the adhesive.
Further, in the heat treatment step, if the Tm / s is less than 1.1, the treatment time is long, so that the cord is burnt, and the cord strength is reduced. On the other hand, if the Tm / s exceeds 8.7, the treatment time. Is short, and the adhesive layer is not sufficiently covered with the cord. This Tm / s is preferably 1.5 to 6.5, more preferably 1.9 to 4.5, from the viewpoint of cord strength and adhesiveness. In addition, the hardening process temperature Tm in a heat treatment process is about 150-260 degreeC normally, Preferably it is 160-250 degreeC, and hardening processing time is about 40-240 s normally, Preferably it is 60-180 s.

As the RFL adhesive used in the present invention, either a conventionally known one-bath type or two-bath type can be used.
Specifically, after a cord containing at least 50% by mass of polyketone fiber is treated with a first liquid containing an epoxy compound or a blocked isocyanate compound, resorcin, formaldehyde, various latexes, sodium hydroxide and / or aqueous ammonia are contained. A two-bath type adhesion method in which treatment is performed with the second solution (RFL solution); treatment with a mixed solution of a solution commonly called N3 produced from triallyl cyanurate, resorcin, formaldehyde, and aqueous ammonia and an RFL solution A one-bath type adhesion method; a reaction product mainly composed of 2,6-bis (2 ′, 4′-dihydroxyphenylmethyl) -4-chlorophenol formed from p-chlorophenol and formaldehyde; A liquid called form PEXUL consisting of formaldehyde and aqueous ammonia A one-bath type adhesion method in which treatment is performed with a liquid mixed with an RFL liquid; a liquid obtained by aging a polyhydric phenol polysulfide and a condensate of resorcinol and formaldehyde, disclosed in JP-A-60-72972, in an alkali And a one-bath-type bonding method in which a mixture of the RFL liquid and the liquid is used.
In addition, it is good to provide a heat set zone and a normalizing zone in the heating tension treatment in the drying treatment step and the heat treatment step.

As the RFL adhesive, a dip solution containing resorcin / formaldehyde resin and rubber latex is used.
The dip liquid can be obtained, for example, by condensing resorcin and formaldehyde or resorcin / formaldehyde precondensate with formaldehyde by resorification reaction in the presence of rubber latex. This resolation reaction is usually carried out at a pH of 8.0 or higher, preferably 8.5 to 10.0. Here, the said resorcin-formaldehyde initial condensate contains the structural unit derived from formaldehyde and the structural unit derived from resorcin, and refers to the state where the structural unit derived from formaldehyde is stoichiometrically insufficient. That is, this makes the resin low in molecular weight and soluble.

As the rubber latex, styrene-butadiene copolymer latex and / or vinylpyridine-styrene-butadiene terpolymer latex can be used. Particularly, vinylpyridine-styrene-butadiene terpolymer is used. Latex is preferable, and the mass ratio of the structural unit derived from vinylpyridine, the structural unit derived from styrene, and the structural unit derived from butadiene is preferably 10:10:80 to 20:50:30.
This vinylpyridine-styrene-butadiene terpolymer latex can be obtained as a commercial product, and examples thereof include those manufactured by Japan A & L, trade name “PYRATEX”, and a solid content of 41% by mass.

In the present invention, vinylpyridine-styrene-butadiene terpolymer latex may be used alone, or one or more other rubber latexes may be used in combination as long as the effects of the present invention are not impaired. .
Examples of other rubber latex include modified latex obtained by modifying a vinylpyridine-styrene-butadiene copolymer with a carboxy group, styrene-butadiene latex and modified latex thereof, natural rubber latex, acrylate copolymer latex, butyl rubber, and the like. In addition to latex and chloroprene rubber latex, latex prepared by dispersing a rubber component of the same type as the rubber component blended in the adherend rubber in water or an organic solvent can be used.

The vinylpyridine-styrene-butadiene terpolymer is obtained by terpolymerization of a vinylpyridine compound, a styrene compound, and a butadiene compound. Here, the vinylpyridine-based compound includes vinylpyridine and a substituted vinylpyridine in which a hydrogen atom in the vinylpyridine is substituted with a substituent. Examples of the vinylpyridine compounds include 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, 5-ethyl-2-vinylpyridine, etc. Among these, 2 -Vinylpyridine is preferred. These vinylpyridine compounds may be used alone or in combination of two or more.

The styrene compound includes styrene and substituted styrene in which a hydrogen atom in the styrene is substituted with a substituent. Examples of the styrene compound include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, Examples thereof include hydroxymethylstyrene, and among these, styrene is preferable. These styrenic compounds may be used alone or in combination of two or more.
Examples of the butadiene compound include 1,3-butadiene and 2-methyl-1,3-butadiene. Among these, 1,3-butadiene is preferable. These butadiene compounds may be used alone or in combination of two or more.

  In the two-bath type adhesion method, the epoxy compound used in the first liquid is diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol / diglycidyl ether, glycerol / polyglycidyl ether, trimethylolpropane / polyglycidyl ether, polyglycerol / polyglycidyl ether, pentaerythritol / polyglycidyl ether, diglycerol / polyglycidyl ether, sorbitol / polyglycidyl ether, etc. Products of Polyhydric Alcohols with Epichlorohydrin; Phenol Novolac Type Epoxy Resin, Cresol Novolac Novolak epoxy resins such as epoxy resins; bisphenol A type epoxy resins.

In the two-bath type adhesion method, the blocked isocyanate compound used in the first liquid is a free isocyanate group of the isocyanate compound blocked with a thermal dissociation blocking agent, and does not react with water at room temperature, By heating, the blocking agent is dissociated and the active isocyanate group is regenerated.
As the blocked isocyanate compound, those obtained by blocking an organic polyisocyanate compound such as diphenylmethane diisocyanate (MDI) or tolylene diisocyanate (TDI) with a blocking agent are preferably used. Examples of the blocking agent include phenols such as phenol, thiophenol, chlorophenol, cresol, resorcinol, p-sec-butylphenol, p-tert-butylphenol, p-sec-amylphenol, p-octylphenol, and p-nonylphenol; Secondary or tertiary alcohols such as isopropyl alcohol and tert-butyl alcohol; aromatic secondary amines such as diphenylamine; phthalimides; lactams such as δ-valerolactam; caprolactams such as ε-caprolactam Active methylene compounds such as malonic acid dialkyl ester, acetylacetone and acetoacetic acid alkyl ester; ketoximes such as acetoxime, methylethylketoxime and cyclohexanone oxime; 3-hydroxy Examples thereof include basic nitrogen compounds such as pyridine and acidic sodium sulfite.
Phenol, ε-caprolactam and ketoxime are preferred as the blocking agent.

In the present invention, the adhesion amount of the reinforcing fiber cord obtained by applying the RFL adhesive as described above and then subjected to a drying and curing treatment is 1.5 to 9.9 with respect to the mass of the cord before the treatment. It is preferably 0% by mass. If the adhesion amount is 1.5% by mass or more, good adhesiveness can be exhibited, and if it is 9.0% by mass or less, the occurrence of a decrease in cord strength due to an increase in cord hardness is suppressed. can do. A more preferable adhesion amount is 2.5 to 7.0% by mass.
In the present invention, the reinforcing fiber cord constituting the carcass ply preferably has a twist coefficient N represented by the following formula (1) satisfying the relationship of the following formula (2).
N = n × (0.125D / ρ) ^1/2 × 10 ⁻³ (1)
0.34 ≦ N (2)
[Wherein n is the number of upper twists (times / 10 cm), D is the total display decitex, and ρ is the density (g / cm ³ ) of the fiber containing at least 50% by mass of polyketone fiber. ]
If the twist coefficient N is 0.34 or more, fatigue resistance necessary as a carcass ply can be ensured. As the twist coefficient N, the formula (2-a)
0.6 ≦ N ≦ 0.9 (2-a)
It is more preferable to satisfy. If the twist coefficient N is 0.9 or less, deterioration of workability due to twisting back of the twisted yarn can be suppressed. A more preferable twist coefficient N is in a range of 0.7 ≦ N ≦ 0.8.

In the present invention, the number of reinforcing fiber cords constituting the carcass ply is preferably 30 to 60/50 mm. The strength and durability of the carcass can be obtained by setting the number of reinforcing fiber cords constituting the carcass ply within the above range. Even if the number of driving exceeds 60/50 mm, there is no particular limitation as long as driving can be performed.
Further, the reinforcing fiber cord constituting the carcass ply containing at least 50% by mass of the polyketone fiber is preferably twisted in two or three filament bundles having a fineness of 500 to 2000 dtex.
By setting the fineness of the cord used for the reinforcing fiber cord within the above range, the elastic modulus and the heat shrinkage stress can be secured and the driving can be made dense. Moreover, it is preferable to twist two or three filament bundles.

(Function of reinforcing fiber cord)
In the pneumatic tire of the present invention, as a reinforcing fiber cord constituting the carcass ply, a general rayon fiber is obtained by applying an RFL adhesive to a cord containing at least 50% by mass of a polyketone fiber, followed by drying and curing treatment. Compared with a carcass ply using a reinforcing cord using a sword, the longitudinal spring constant during run-flat traveling can be improved while maintaining the longitudinal spring constant of the tire during normal internal pressure traveling. As a result, by using the carcass ply to which the reinforcing fiber cord according to the present invention is applied for the pneumatic tire, it is possible to improve the run-flat durability while maintaining the tire riding comfort during normal running. This is an action utilizing the fact that the tensile strain generated in the cord during run-flat traveling is significantly larger than the tensile strain generated in the cord when the tire is filled with air.
In addition, the reinforcing fiber cord containing at least 50% by mass of the polyketone fiber is higher in strength than the reinforcing fiber cord using the rayon fiber, so even if the number of the reinforcing fiber cords arranged in the carcass ply is reduced, the run flat running It is possible to maintain the run-flat durability performance by maintaining the longitudinal spring constant of the tire at the time. On the other hand, by reducing the number of reinforcing fiber cords arranged, it is possible to reduce the longitudinal spring constant of the tire during normal running and to improve riding comfort.

[Rubber composition]
In the pneumatic tire of the present invention, as described above, the reinforcing fiber cord constituting the carcass ply is obtained by applying an RFL adhesive to a cord containing at least 50% by mass of a polyketone fiber, followed by drying and curing treatment. The run-flat durability can be improved without impairing the rolling resistance and riding comfort during normal running. Further, a rubber composition having the following specific vulcanized rubber properties can be used as a reinforced rubber. As described above, the use of at least one of the tire members, particularly the side reinforcing layer and / or the bead filler, can significantly improve the run-flat durability by a synergistic effect.

FIG. 1 is a schematic view showing a cross-sectional view of one embodiment of the pneumatic tire of the present invention.
In FIG. 1, a preferred embodiment of the pneumatic tire of the present invention is toroidally connected between a pair of bead cores 1, 1 ′ (1 ′ is not shown), and both ends of the bead core 1 are located outside the tire from the inside. A carcass layer 2 composed of at least one radial carcass ply wound up, a side rubber layer 3 disposed on the outer side in the tire axial direction of the side region of the carcass layer 2, and a crown region of the carcass layer 2 A tread rubber layer 4 disposed on the outer side in the tire radial direction to form a contact portion, a belt layer 5 disposed between the tread rubber layer 4 and the crown region of the carcass layer 2 to form a reinforcing belt, An inner liner 6 disposed on the entire inner surface of the tire of the carcass layer 2 to form an airtight film, and the case extending from one bead core 1 to the other bead core 1 ′. The bead filler 7 disposed between the main body portion of the cass layer 2 and the winding portion wound up on the bead core 1, and the carcass layer 2 extending from the side of the bead filler 7 in the side region of the carcass layer to the shoulder region 10. A pneumatic tire having at least one side reinforcing layer 8 having a cross-sectional shape along the tire rotation axis and a substantially crescent shape between the inner liner 6 and the inner liner 6. By using the rubber composition according to the present invention for the side reinforcing layer 8 and / or the bead filler 7 of the pneumatic tire, the pneumatic tire of the present invention can exhibit the above-described effects.

In the pneumatic tire of the present invention described above, the side reinforcing layer 8 and / or the bead filler 7 includes (A) a rubber component and 100 parts by mass of (B) 55 parts by mass of carbon black, and A rubber composition having an elastic modulus at 100% elongation (M100) of 10 MPa or more and a sigma value of tangent loss tan δ at 28 ° C. to 150 ° C. of 6.0 or less in vulcanized rubber properties can be used.
((A) rubber component)
As the rubber component (A) in the rubber composition according to the present invention, one containing an amine-modified conjugated diene polymer obtained by amine-modifying a conjugated diene polymer can be preferably used. A polymer containing 30% by mass or more, preferably 50% by mass or more can be used. When the rubber component contains the modified conjugated diene polymer in an amount of 30% by mass or more, the resulting rubber composition can provide a pneumatic tire with low heat generation and improved run-flat running durability.

As the amine-modified conjugated diene polymer, a polymer in which a protonic amino group which is an amine functional group and / or an amino group protected by a detachable group is introduced as a functional group for modification in the molecule is preferable. Further, those having a silicon atom-containing functional group introduced are preferred.
Examples of the functional group containing a silicon atom include a silane group formed by bonding a hydrocarbyloxy group and / or a hydroxy group to a silicon atom.
Such a functional group for modification may be present at any of the polymerization initiation terminal, the side chain, and the polymerization active terminal of the conjugated diene polymer. In the present invention, it is preferably a polymerization terminal, more preferably the same polymerization. A silicon atom having an amino group protected with a protic amino group and / or a detachable group and a hydrocarbyloxy group and / or a hydroxy group, particularly preferably one or two hydrocarbyloxy groups, And / or a silicon atom having a hydroxy group bonded thereto.

Examples of the protic amino group include at least one selected from a primary amino group, a secondary amino group, and salts thereof.
On the other hand, examples of the amino group protected with a detachable group include N, N-bis (trihydrocarbylsilyl) amino group and N- (trihydrocarbylsilyl) imino group. Preferably, the hydrocarbyl group is carbon. The trialkylsilyl group which is a C1-C10 alkyl group can be mentioned, Especially preferably, a trimethylsilyl group can be mentioned.
An example of a primary amino group protected with a detachable group (also referred to as a protected primary amino group) is N, N-bis (trimethylsilyl) amino group, which is protected with a detachable group. Examples of the secondary amino group include N- (trimethylsilyl) imino group. The N- (trimethylsilyl) imino group-containing group may be an acyclic imine residue or a cyclic imine residue.

  Among the amine-modified conjugated diene polymers described above, from the viewpoint of improving the dispersibility of the filler, the primary amine-modified conjugated diene polymer modified with a primary amino group is the active terminal of the conjugated diene polymer. In addition, a primary amine-modified conjugated diene polymer modified with a protected primary amino group obtained by reacting a protected primary amine compound is preferred.

<Conjugated diene polymer>
The conjugated diene polymer used for modification may be a conjugated diene compound homopolymer or a copolymer of a conjugated diene compound and an aromatic vinyl compound.
Examples of the conjugated diene compound include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene, and the like. Is mentioned. These may be used alone or in combination of two or more, and among these, 1,3-butadiene is particularly preferred.
Examples of the aromatic vinyl compound used for copolymerization with the conjugated diene compound include styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, and 4-cyclohexylstyrene. 2,4,6-trimethylstyrene and the like. These may be used alone or in combination of two or more, but among these, styrene is particularly preferred.
As the conjugated diene polymer, polybutadiene or styrene-butadiene copolymer is preferable, and polybutadiene is particularly preferable.

  In order to modify the active end of the conjugated diene polymer by reacting with a protected primary amine, it is preferable that the conjugated diene polymer has at least 10% polymer chains having a living property or pseudo-living property. Examples of such a polymerization reaction having a living property include a reaction in which an organic alkali metal compound is used as an initiator and a conjugated diene compound alone or an conjugated diene compound and an aromatic vinyl compound are anionically polymerized in an organic solvent. .

  As the organic alkali metal compound used as an initiator for the above-mentioned anionic polymerization, a lithium compound is preferable. The lithium compound is not particularly limited, but hydrocarbyl lithium and lithium amide compounds are preferably used. When the former hydrocarbyl lithium is used, it has a hydrocarbyl group at the polymerization initiation terminal and the other terminal is a polymerization active site. A conjugated diene polymer is obtained. When the latter lithium amide compound is used, a conjugated diene polymer having a nitrogen-containing group at the polymerization initiation terminal and the other terminal being a polymerization active site is obtained.

  As the hydrocarbyl lithium, those having a hydrocarbyl group having 2 to 20 carbon atoms are preferable, for example, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, n-decyl. Examples include lithium, phenyllithium, 2-naphthyllithium, 2-butylphenyllithium, 4-phenylbutyllithium, cyclohexyllithium, cyclobenthyllithium, and reactive organisms of diisopropenylbenzene and butyllithium. Of these, n-butyllithium is particularly preferred.

On the other hand, examples of the lithium amide compound include lithium hexamethylene imide, lithium pyrrolidide, lithium piperide, lithium heptamethylene imide, lithium dodecamethylene imide, lithium dimethyl amide, lithium diethyl amide, lithium dibutyl amide, lithium dipropyl amide, and lithium disulfide. Heptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium-N-methylpiverazide, lithium ethylpropylamide, lithium ethylbutyramide, lithium ethylbenzylamide, lithium methylphenethylamide, etc. Is mentioned. Among these, from the viewpoint of the interaction effect on carbon black and the ability to initiate polymerization, cyclic hexaamides such as lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethylene imide, and lithium dodecamethylene imide are preferable, In particular, lithium hexamethylene imide and lithium pyrrolidide are suitable.
In general, these lithium amide compounds prepared from a secondary amine and a lithium compound can be used for polymerization, but can also be prepared in a polymerization system (in-situ). The amount of the polymerization initiator used is preferably selected in the range of 0.2 to 20 mmol per 100 g of monomer.

A method for producing a conjugated diene polymer by anionic polymerization using the lithium compound as a polymerization initiator is not particularly limited, and a conventionally known method can be used.
Specifically, in an organic solvent inert to the reaction, for example, a hydrocarbon solvent such as an aliphatic, alicyclic, and aromatic hydrocarbon compound, the conjugated diene compound or the conjugated diene compound and the aromatic vinyl compound are If desired, a conjugated diene polymer having an active terminal can be obtained by anionic polymerization in the presence of a randomizer to be used, if desired, using a lithium compound as a polymerization initiator.
In addition, when a lithium compound is used as a polymerization initiator, not only a conjugated diene polymer having an active end but also a copolymer of a conjugated diene compound having an active end and an aromatic vinyl compound can be obtained efficiently. it can.

The hydrocarbon solvent is preferably one having 3 to 8 carbon atoms, such as propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propene, 1-butene, isobutene, trans-2. -Butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene and the like. These may be used singly or in combination of two or more.
The monomer concentration in the solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass. When copolymerization is performed using a conjugated diene compound and an aromatic vinyl compound, the content of the aromatic vinyl compound in the charged monomer mixture is preferably in the range of 55% by mass or less.

  The randomizer used as desired is a control of the microstructure of the conjugated diene polymer, such as an increase in 1,2 bonds in the butadiene portion in the butadiene-styrene copolymer, an increase in 3,4 bonds in the isoprene polymer, or the like. It is a compound having an effect of controlling the composition distribution of monomer units in a conjugated diene compound-aromatic vinyl compound copolymer, for example, randomizing butadiene units and styrene units in a butadiene-styrene copolymer. The randomizer is not particularly limited, and any one of known compounds generally used as a conventional randomizer can be appropriately selected and used. Specifically, dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, oxolanylpropane oligomers [especially those containing 2,2-bis (2-tetrahydrofuryl) -propane, etc.], triethylamine, pyridine N-methylmorpholine, N, N, N ′, N′-tetramethylethylenediamine, ethers such as 1,2-dipiperidinoethane, and tertiary amines. Further, potassium salts such as potassium tert-amylate and potassium tert-butoxide, and sodium salts such as sodium tert-amylate can also be used.

One of these randomizers may be used alone, or two or more thereof may be used in combination. The amount used is preferably selected in the range of 0.01 to 1000 molar equivalents per mole of the lithium compound.
The temperature in this polymerization reaction is preferably selected in the range of 0 to 150 ° C, more preferably 20 to 130 ° C. The polymerization reaction can be carried out under generated pressure, but it is usually desirable to operate at a pressure sufficient to keep the monomer in a substantially liquid phase. That is, the pressure depends on the particular material being polymerized, the polymerization medium used and the polymerization temperature, but higher pressures can be used if desired, such pressure being a gas that is inert with respect to the polymerization reaction. Can be obtained by an appropriate method such as pressurizing.

<Modifier>
In the present invention, a primary amine-modified conjugated diene polymer is reacted with a protected primary amine compound as a modifier on the active terminal of the conjugated diene polymer having an active terminal obtained as described above. Can be manufactured. As the protected primary amine compound, an alkoxysilane compound having a protected primary amino group is suitable.
Examples of the alkoxysilane compound having a protected primary amino group used as the modifier include N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, 1-trimethylsilyl-2,2-dimethoxy-1-aza-2- Silacyclopentane, N, N-bis (trimethylsilyl) aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) aminopropyltriethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane, N, N -Bis (trimethylsilyl) aminoethyltrimethoxysilane, N, N-bis (trimethylsilyl) aminoethyltriethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane and N, N-bis (trimethylsilyl) Aminoethylmethyldiethoxysilane and the like, preferably N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane or 1-trimethylsilyl-2 , 2-dimethoxy-1-aza-2-silacyclopentane.

Moreover, as a modifier, N-methyl-N-trimethylsilylaminopropyl (methyl) dimethoxysilane, N-methyl-N-trimethylsilylaminopropyl (methyl) diethoxysilane, N-trimethylsilyl (hexamethyleneimin-2-yl) Propyl (methyl) dimethoxysilane, N-trimethylsilyl (hexamethyleneimin-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (pyrrolidin-2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (pyrrolidine- 2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (piperidin-2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (piperidin-2-yl) propyl (methyl) diethoxysila N-trimethylsilyl (imidazol-2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (imidazol-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (4,5-dihydroimidazol-5-yl) ) Alkoxysilane compounds having protected secondary amino groups such as propyl (methyl) dimethoxysilane, N-trimethylsilyl (4,5-dihydroimidazol-5-yl) propyl (methyl) diethoxysilane; N- (1,3 -Dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, N- (1-methylethylidene) -3- (triethoxysilyl) -1-propanamine, N-ethylidene-3- (triethoxy Silyl) -1-propanamine, N- (1-methylpropiyl) Den) -3- (triethoxysilyl) -1-propanamine, N- (4-N, N-dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine, N- (cyclohexylidene) Alkoxysilane compounds having an imino group such as -3- (triethoxysilyl) -1-propanamine; 3-dimethylaminopropyl (triethoxy) silane, 3-dimethylaminopropyl (trimethoxy) silane, 3-diethylaminopropyl (triethoxy) Silane, 3-diethylaminopropyl (trimethoxy) silane, 2-dimethylaminoethyl (triethoxy) silane, 2-dimethylaminoethyl (trimethoxy) silane, 3-dimethylaminopropyl (diethoxy) methylsilane, 3-dibutylaminopropyl (triethoxy) silane Examples thereof include alkoxysilane compounds having an amino group such as lan.
These modifiers may be used alone or in combination of two or more. The modifier may be a partial condensate.
Here, the partial condensate means a product in which a part (not all) of the modifier SiOR is SiOSi bonded by condensation.

In the modification reaction with the modifying agent, the amount of the modifying agent used is preferably 0.5 to 200 mmol / kg · conjugated diene polymer. The amount used is more preferably 1 to 100 mmol / kg · conjugated diene polymer, and particularly preferably 2 to 50 mmol / kg · conjugated diene polymer. Here, the conjugated diene polymer means the mass of only a polymer that does not contain an additive such as an anti-aging agent added during or after the production. By making the usage-amount of a modifier into the said range, it is excellent in the dispersibility of a filler, especially carbon black, and the fracture resistance after vulcanization and low heat build-up are improved.
The method of adding the modifier is not particularly limited, and examples thereof include a method of adding all at once, a method of adding in divided portions, a method of adding continuously, and the like. preferable.
Further, the modifier can be bonded to any of the polymer main chain and the side chain other than the polymerization initiation terminal and the polymerization termination terminal, but it can suppress the loss of energy from the polymer terminal and improve the low heat generation. Therefore, it is preferably introduced at the polymerization initiation terminal or the polymerization termination terminal.

<Condensation accelerator>
In the present invention, a condensation accelerator is preferably used in order to accelerate the condensation reaction involving the alkoxysilane compound having a protected primary amino group used as the modifier.
Examples of such a condensation accelerator include a compound containing a tertiary amino group, or among group 3, 4, 5, 12, 13, 14, and 15 of the periodic table (long period type). An organic compound containing one or more elements belonging to any of the above can be used. Furthermore, as a condensation accelerator, an alkoxide, a carboxyl containing at least one metal selected from the group consisting of titanium (Ti), zirconium (Zr), bismuth (Bi), aluminum (Al), and tin (Sn). It is preferably an acid salt or an acetylacetonate complex salt.
The condensation accelerator used here can be added before the modification reaction, but is preferably added to the modification reaction system during and / or after the modification reaction. When added before the denaturation reaction, a direct reaction with the active end may occur, and a hydrocarbyloxy group having a protected primary amino group at the active end may not be introduced.
The addition time of the condensation accelerator is usually 5 minutes to 5 hours after the start of the modification reaction, preferably 15 minutes to 1 hour after the start of the modification reaction.

  Specific examples of the condensation accelerator include tetrakis (2-ethyl-1,3-hexanediolato) titanium, tetrakis (2-methyl-1,3-hexanediolato) titanium, tetrakis (2-propyl-1). , 3-hexanediolato) titanium, tetrakis (2-butyl-1,3-hexanediolato) titanium, tetrakis (1,3-hexanediolato) titanium, tetrakis (1,3-pentanediolato) titanium, tetrakis (2-Methyl-1,3-pentanediolato) titanium, tetrakis (2-ethyl-1,3-pentanediolato) titanium, tetrakis (2-propyl-1,3-pentanediolato) titanium, tetrakis (2 -Butyl-1,3-pentanediolato) titanium, tetrakis (1,3-heptanediolato) titanium, tetrakis (2-methyl-1, -Heptanediolato) titanium, tetrakis (2-ethyl-1,3-heptanediolato) titanium, tetrakis (2-propyl-1,3-heptanediolato) titanium, tetrakis (2-butyl-1,3-heptanediolato) titanium, tetrakis (2 -Ethylhexoxy) titanium, tetramethoxy titanium, tetraethoxy titanium, tetra-n-propoxy titanium, tetraisopropoxy titanium, tetra-n-butoxy titanium, tetra-n-butoxy titanium oligomer, tetraisobutoxy titanium, tetra-sec-butoxy Titanium, tetra-tert-butoxytitanium, bis (oleate) bis (2-ethylhexanoate) titanium, titanium dipropoxybis (triethanolamate), titanium dibutoxybis (triethanolamate), Tantributoxy systemate, titanium tripropoxy systemate, titanium tripropoxyacetylacetonate, titanium dipropoxybis (acetylacetonate), titanium tripropoxy (ethylacetoacetate), titanium propoxyacetylacetonatebis (ethylacetoacetate), Titanium tributoxyacetylacetonate, titanium dibutoxybis (acetylacetonate), titanium tributoxyethylacetoacetate, titaniumbutoxyacetylacetonatebis (ethylacetoacetate), titanium tetrakis (acetylacetonate), titanium diacetylacetonatebis ( Ethyl acetoacetate), bis (2-ethylhexanoate) titanium oxide, bis (laurate) titanium oxide, bis (naphthene) ) Titanium oxide, bis (stearate) titanium oxide, bis (oleate) titanium oxide, bis (linoleate) titanium oxide, tetrakis (2-ethylhexanoate) titanium, tetrakis (laurate) titanium, tetrakis (naphthenate) titanium , Tetrakis (stearate) titanium, tetrakis (oleate) titanium, tetrakis (linoleate) titanium, titanium di-n-butoxide (bis-2,4-pentanedionate), titanium oxide bis (tetramethylheptanedionate), titanium oxide Examples thereof include compounds containing titanium such as bis (pentanedionate) and titanium tetra (lactate). Among these, tetrakis (2-ethyl-1,3-hexanediolato) titanium, tetrakis (2-ethylhexoxy) titanium, and titanium di-n-butoxide (bis-2,4-pentanedionate) are preferable.

  Examples of the condensation accelerator include tris (2-ethylhexanoate) bismuth, tris (laurate) bismuth, tris (naphthenate) bismuth, tris (stearate) bismuth, tris (oleate) bismuth, and tris (linoleate). Bismuth, tetraethoxyzirconium, tetra-n-propoxyzirconium, tetraisopropoxyzirconium, tetra-n-butoxyzirconium, tetra-sec-butoxyzirconium, tetra-tert-butoxyzirconium, tetra (2-ethylhexoxy) zirconium, zirconium tributoxy Stearate, zirconium tributoxyacetylacetonate, zirconium dibutoxybis (acetylacetonate), zirconium tributoxyethylacetoacetate , Zirconium butoxyacetylacetonate bis (ethylacetoacetate), zirconium tetrakis (acetylacetonate), zirconium diacetylacetonate bis (ethylacetoacetate), bis (2-ethylhexanoate) zirconium oxide, bis (laurate) zirconium oxide Bis (naphthenate) zirconium oxide, bis (stearate) zirconium oxide, bis (oleate) zirconium oxide, bis (linoleate) zirconium oxide, tetrakis (2-ethylhexanoate) zirconium, tetrakis (laurate) zirconium, tetrakis (naphthenate) ) Zirconium, tetrakis (stearate) zirconium, tetrakis (oleate) zirconium Tetrakis (linolate) zirconium and the like.

  Also, triethoxyaluminum, tri-n-propoxyaluminum, triisopropoxyaluminum, tri-n-butoxyaluminum, tri-sec-butoxyaluminum, tri-tert-butoxyaluminum, tri (2-ethylhexoxy) aluminum, aluminum dibutoxy Stearate, aluminum dibutoxyacetylacetonate, aluminum butoxybis (acetylacetonate), aluminum dibutoxyethylacetoacetate, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), tris (2-ethylhexanoate) ) Aluminum, Tris (laurate) aluminum, Tris (naphthenate) aluminum, Tris (stearate) aluminum, Squirrel (oleate) aluminum, tris (linolate) aluminum, and the like.

Of the above condensation accelerators, titanium compounds are preferable, and titanium metal alkoxides, titanium metal carboxylates, or titanium metal acetylacetonate complex salts are particularly preferable.
The amount of the condensation accelerator used is preferably such that the number of moles of the compound is 0.1 to 10 as the molar ratio to the total amount of hydrocarbyloxy groups present in the reaction system, and 0.5 to 5 Particularly preferred. By setting the use amount of the condensation accelerator within the above range, the condensation reaction proceeds efficiently.

The condensation reaction in the present invention proceeds in the presence of the above-described condensation accelerator and water vapor or water. An example of the presence of water vapor is a solvent removal treatment by steam stripping, and the condensation reaction proceeds during steam stripping.
Moreover, you may perform a condensation reaction in aqueous solution, 30-180 degreeC of condensation reaction temperature is preferable, 85-180 degreeC is more preferable, More preferably, it is 100-170 degreeC, Especially preferably, it is 110-150 degreeC.
By setting the temperature during the condensation reaction within the above range, the condensation reaction can be efficiently advanced and completed, and the deterioration of the quality due to the aging reaction of the polymer due to the aging of the resulting modified conjugated diene polymer is suppressed. Can do.

The condensation reaction time is usually about 5 minutes to 10 hours, preferably about 15 minutes to 5 hours. By setting the condensation reaction time within the above range, the condensation reaction can be completed smoothly.
In addition, the pressure of the reaction system at the time of condensation reaction is 0.01-20 Mpa normally, Preferably it is 0.05-10 Mpa.
There are no particular restrictions on the type of the condensation reaction carried out in an aqueous solution, and the reaction may be carried out continuously using a batch type reactor or an apparatus such as a multistage continuous reactor. Moreover, you may perform this condensation reaction and a desolvent simultaneously.
The primary amino group derived from the modifier of the modified conjugated diene polymer according to the present invention is generated by performing a deprotection treatment as described above. Specific examples of suitable deprotection treatments other than the solvent removal treatment using steam such as steam stripping described above will be described in detail below.
That is, the protecting group on the primary amino group is converted to a free primary amino group by hydrolysis. By removing the solvent, a modified conjugated diene polymer having a primary amino group can be obtained. In addition, the deprotection treatment of the protected primary amino group derived from the modifier can be performed as necessary in any stage from the step including the condensation treatment to the solvent removal to the dry polymer.

<Modified conjugated diene polymer>
The modified conjugated diene polymer thus obtained has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of preferably 10 to 150, more preferably _{15 to} 100. When the Mooney viscosity is less than 10, sufficient rubber physical properties such as fracture resistance characteristics cannot be obtained.
The Mooney viscosity (ML _{1 + 4} , 130 ° C.) of the unvulcanized rubber composition according to the present invention containing the modified conjugated diene polymer is preferably 10 to 150, more preferably 30 to 100. .
The modified conjugated diene polymer used in the rubber composition according to the present invention has a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), that is, the molecular weight distribution (Mw / Mn) is 1. It is preferable that it is -3, and it is more preferable that it is 1.1-2.7.
By making the molecular weight distribution (Mw / Mn) of the modified conjugated diene polymer within the above range, even if the modified conjugated diene polymer is blended with the rubber composition, the workability of the rubber composition may be reduced. And kneading is easy, and the physical properties of the rubber composition can be sufficiently improved.

The modified conjugated diene polymer used in the rubber composition according to the present invention preferably has a number average molecular weight (Mn) of 100,000 to 500,000, preferably 150,000 to 300,000. Is more preferable. By setting the number average molecular weight of the modified conjugated diene polymer within the above range, the elastic modulus of the vulcanizate is reduced and an increase in hysteresis loss is suppressed to obtain excellent fracture resistance, and the modified conjugated diene polymer Excellent kneading workability of the rubber composition containing can be obtained.
The modified conjugated diene polymer used in the rubber composition according to the present invention may be used singly or in combination of two or more.

<Other rubber components>
(A) In the rubber component, examples of the rubber component used in combination with the modified conjugated diene polymer include natural rubber and other diene synthetic rubbers. Examples of other diene synthetic rubbers include styrene-butadiene copolymer. Polymer (SBR), polybutadiene (BR), polyisoprene (IR), styrene-isoprene copolymer (SIR), butyl rubber (IIR), halogenated butyl rubber, ethylene-propylene-diene terpolymer (EPDM) and These mixtures are mentioned. Further, some or all of the other diene-based synthetic rubber is more preferably a diene-based modified rubber having a branched structure by using a polyfunctional modifier, for example, a modifier such as tin tetrachloride. .

((B) Carbon black)
In the rubber composition according to the present invention, it is necessary to use carbon black as the component (B) at a ratio of 55 parts by mass or more with respect to 100 parts by mass of the rubber component (A) described above. When the amount of carbon black is less than 55 parts by mass, sufficient reinforcing effect is not exhibited, and in the vulcanized rubber properties of the resulting rubber composition, the elastic modulus at 100% elongation (M100) described later does not exceed 10 MPa. There is. If the amount of carbon black is too large, the Σ value at 28 ° C. to 150 ° C. of the tangent loss tan δ described later may not be 6.0 or less in the physical properties of the vulcanized rubber of the resulting rubber composition. Therefore, the preferable amount of the carbon black is 55 to 80 parts by mass, more preferably 55 to 70 parts by mass, and particularly preferably 60 to 70 parts by mass.
As the carbon black, in order that the vulcanized rubber physical properties of the obtained rubber composition satisfy the above vulcanized rubber physical properties, FEF grade, FF grade, HAF grade, ISAF grade and SAF grade It is preferable to use at least one selected from among them, and in particular, the FEF grade grade is suitable for achieving low heat generation.

Further, the rubber composition according to the present invention includes various chemicals usually used in the rubber industry, for example, a vulcanizing agent, a vulcanization accelerator, a process oil, an aging, as desired, as long as the effects of the present invention are not impaired. An inhibitor, a scorch inhibitor, zinc white, stearic acid and the like can be contained.
As said vulcanizing agent, sulfur etc. are mentioned, The usage-amount is 0.1-10.0 mass parts as sulfur content with respect to 100 mass parts of (A) rubber components, More preferably, it is 1.0. -5.0 parts by mass. If the amount is less than 0.1 parts by mass, the rupture strength, wear resistance, and low heat build-up of the vulcanized rubber may be reduced. If the amount exceeds 10.0 parts by mass, the rubber elasticity is lost.
The vulcanization accelerator that can be used in the present invention is not particularly limited, and examples thereof include M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), and CZ (N-cyclohexyl-2-benzothiazyl). Thiophene vulcanization accelerators such as thiazoles such as sulfenamide), guanidines such as DPG (diphenylguanidine), or thiurams such as TOT (tetrakis (2-ethylhexyl) thiuram disulfide). The amount used is preferably from 0.1 to 5.0 parts by weight, more preferably from 0.2 to 3.0 parts by weight, per 100 parts by weight of the (A) rubber component.

Examples of the process oil used as a softening agent that can be used in the rubber composition according to the present invention include paraffinic, naphthenic, and aromatic oils. Aromatics are used for applications that emphasize tensile strength and wear resistance, and naphthenic or paraffinic systems are used for applications that emphasize hysteresis loss and low-temperature characteristics. The amount used is preferably 0 to 100 parts by mass with respect to 100 parts by mass of the rubber component (A), and if it is 100 parts by mass or less, the tensile strength and low heat build-up (low fuel consumption) of the vulcanized rubber deteriorate. Can be suppressed.
Furthermore, examples of the antioxidant that can be used in the rubber composition according to the present invention include 3C (N-isopropyl-N′-phenyl-p-phenylenediamine, 6C [N- (1,3-dimethylbutyl) -N ′). -Phenyl-p-phenylenediamine], AW (6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline), high-temperature condensate of diphenylamine and acetone, etc. (A) 0.1-5.0 mass part is preferable with respect to 100 mass parts of rubber components, More preferably, it is 0.3-3.0 mass part.

(Physical properties of vulcanized rubber of rubber composition)
It is important that the rubber composition according to the present invention has a 100% elongation elastic modulus (M100) of 10 MPa or more as a vulcanized rubber property. When the elastic modulus (M100) is less than 10 MPa, the tire is not sufficiently bent during run-flat running, and the run-flat running durability of the tire is reduced. Preferred M100 is 10.5 MPa or more, and the upper limit thereof is not particularly limited, but is usually about 13 MPa.
The elastic modulus at 100% elongation (M100) is a value measured by the following method.
<Measurement method of elastic modulus at 100% elongation (M100)>
An elastic modulus at 100% elongation is measured based on JIS K 6251 for a slab sheet having a thickness of 2 mm obtained by vulcanizing the rubber composition at 160 ° C. for 12 minutes.

Further, as the physical properties of the vulcanized rubber, it is important that the Σ value [Σ tan δ (28 to 150 ° C.)] at 28 ° C. to 150 ° C. of the tangent loss tan δ is 6.0 or less. When the sigma value of tan δ exceeds 6.0, the heat generation of the tire during run-flat running is large, and the run-flat running durability of the tire is lowered. The lower limit of Σtan δ (28 to 150 ° C.) is not particularly limited, but is usually about 5.
The Σtanδ (28 to 150 ° C.) is a value measured by the following method.
<Measuring method of Σtan δ (28 to 150 ° C.)>
A sheet having a width of 5 mm and a length of 40 mm was cut out from a slab sheet having a thickness of 2 mm obtained by vulcanizing the rubber composition at 160 ° C. for 12 minutes to prepare a sample. About this sample, a tangent loss tan δ was measured under the measurement conditions of a distance between chucks of 10 mm, an initial strain of 200 μm, a dynamic strain of 1%, a frequency of 52 Hz, and a measurement start temperature of 25 to 200 ° C. using a spectrometer manufactured by Ueshima Seisakusho. As shown in FIG. 2, the relationship between temperature and tan δ is graphed, the area of the shaded portion is obtained, and the value is Σ tan δ (28 to 150 ° C.).

(Preparation of rubber composition, production of pneumatic tire)
The rubber composition according to the present invention is obtained by kneading using a kneading machine such as a Banbury mixer, a roll, an internal mixer or the like according to the above compounding prescription, vulcanized after molding, and in FIG. Used as a side reinforcing layer 8 and / or a bead filler 7 of a pneumatic tire.
In the pneumatic tire of the present invention, an RFL adhesive is applied to a cord containing at least 50% by mass of a polyketone fiber as a reinforcing fiber cord constituting a carcass ply used for the carcass layer 2, and is dried and cured under the specific conditions described above. The rubber composition according to the present invention described above is preferably used for the side reinforcing layer 8 and / or the bead filler 7 and can be manufactured by an ordinary run-flat tire manufacturing method.
The pneumatic tire of the present invention thus obtained has improved run-flat durability without impairing rolling resistance and riding comfort during normal running.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Various characteristics were measured according to the following methods.
<< Physical Properties of Unmodified or Modified Conjugated Diene Polymer >>
-Microstructure analysis method The vinyl bond content (%) was measured by an infrared method (morero method).
-Measurement of number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) Measured by GPC [manufactured by Tosoh Corporation, HLC-8020] using a refractometer as a standard, and monodisperse polystyrene is standard It was shown in terms of polystyrene. The column is GMHXL [manufactured by Tosoh], and the eluent is tetrahydrofuran.

<< Physical properties of vulcanized rubber of rubber composition >>
The elastic modulus at 100% elongation (M100) and the Σ value [Σ tan δ (28 to 150 ° C.)] at 28 ° C. to 150 ° C. of the tangent loss tan δ were measured according to the method described in the specification.
<< Evaluation of pneumatic tire >>
・ Run-flat durability Each test tire (passenger car radial tire of tire size 215 / 45ZR17) is assembled with rim at normal pressure, filled with 230kPa of internal pressure, left in a room at 38 ℃ for 24 hours, and then the valve core is The drum running test was performed under the conditions of a load of 4.17 kN (425 kg), a speed of 89 km / h, and an indoor temperature of 38 ° C. The travel distance until failure of each test tire was measured, and the travel distance of Comparative Example 1 was taken as 100, and the index was displayed by the following formula. The larger the index, the better the run flat durability.
Run-flat durability (index) = (travel distance of test tire / travel distance of tire of Comparative Example 1) × 100
・ Riding Comfort Each test tire is mounted on a passenger car, a feeling test of riding comfort is conducted by two specialized drivers, and an average value of 1-10 is obtained. Is shown as an index with 100 being 100. The higher the index, the better the ride comfort.

Production Example 1 Production of Polyketone Fiber A polyketone polymer having an intrinsic viscosity of 5.3, which was prepared by a conventional method and was completely alternatingly copolymerized with ethylene and carbon monoxide, was added to an aqueous solution containing 65% by mass of zinc chloride / 10% by mass of sodium chloride. The mixture was stirred and dissolved at 80 ° C. for 2 hours to obtain a dope having a polymer concentration of 8 mass%.
This dope is heated to 80 ° C., filtered through a 20 μm sintered filter, passed through a 10 mm air gap from a 50-hole spout diameter maintained at 80 ° C., and 5% by mass of zinc chloride. Was extruded at a rate of 2.5 cm ³ / min. Into 18 ° C. water containing a coagulated yarn while drawing at a rate of 3.2 m / min.
Subsequently, the coagulated yarn was washed with a sulfuric acid aqueous solution having a concentration of 2 mass% and a temperature of 25 ° C., and further washed with water at 30 ° C., and then the coagulated yarn was wound at a speed of 3.2 m / min.
The solidified yarn was impregnated with IRGANOX 1098 (manufactured by Ciba Specialty Chemicals) and IRGANOX 1076 (manufactured by Ciba Specialty Chemicals) in an amount of 0.05% by mass (based on polyketone polymer), and then dried at 240 ° C. A finishing agent was applied to obtain an undrawn yarn.

As the finishing agent, oleic acid lauryl ester / bisoxyethyl bisphenol A / polyether (propylene oxide / ethylene oxide = 35/65: molecular weight 20000) / polyethylene oxide 10 mol addition oleyl ether / polyethylene oxide 10 mol addition castor oil ether / The one having a composition of sodium stearyl sulfonate / sodium dioctyl phosphate = 30/30/10/5/23/1/1 (mass% ratio) was used.
The obtained undrawn yarn was drawn at 240 ° C. in the first stage, followed by the second stage at 258 ° C., the third stage at 268 ° C., the fourth stage at 272 ° C., and then the second stage at 200 ° C. The film was stretched five times at 1.08 times (stretching tension 1.8 cN / dtex) and wound with a winder. The total draw ratio from the undrawn yarn to the five-stage drawn yarn was 17.1 times.

Production Example 2 Production of primary amine-modified polybutadiene (1) Polybutadiene In a nitrogen-substituted 5 L autoclave, 1.4 kg of cyclohexane, 250 g of 1,3-butadiene, 2,2-ditetrahydrofurylpropane (0.0285 mmol) cyclohexane under nitrogen. The solution was injected as a solution, and 2.85 mmol of n-butyllithium (BuLi) was added thereto, followed by polymerization in a 50 ° C. warm water bath equipped with a stirrer for 4.5 hours. The reaction conversion of 1,3-butadiene was almost 100%. The polymer solution was drawn into a methanol solution containing 1.3 g of 2,6-di-tert-butyl-p-cresol, and after the polymerization was stopped, the solvent was removed by steam stripping and dried with a roll at 110 ° C. Thus, polybutadiene was obtained. The resulting polybutadiene was measured for microstructure (vinyl bond amount), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn). As a result, the vinyl bond content was 14%, Mw was 150,000, and Mw / Mn was 1.1.
(2) Production of primary amine-modified polybutadiene The polymer solution obtained in (1) above is maintained at a temperature of 50 ° C. without deactivating the polymerization catalyst, and the primary amino group protected N, N-bis ( 1129 mg (3.364 mmol) of trimethylsilyl) aminopropylmethyldiethoxysilane was added and the modification reaction was carried out for 15 minutes. Finally, 2,6-di-tert-butyl-p-cresol was added to the polymer solution after the reaction. Next, the primary amino group, which was desolvated and protected by steam stripping, was removed, and the rubber was dried with a ripening roll adjusted to 110 ° C. to obtain primary amine-modified polybutadiene. The resulting modified polybutadiene was measured for microstructure (vinyl bond amount), weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), and primary amino group content. As a result, the vinyl bond content was 14%, Mw was 150,000, Mw / Mn was 1.2, and the primary amino group content was 4.0 mmol / kg.

Production Example 3 DMBTESPA Modified Polybutadiene In Production Example 2, 1129 mg (3.364 mmol) of N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane was mixed with N- (1,3-dimethylbutylidene) -3- (triethoxysilyl). ) DMBTESPA-modified polybutadiene was obtained in the same manner as in Production Example 2, except that the amount was changed to 3.364 mmol.

Examples 1 to 5 and Comparative Example 1
(1) Production of reinforcing fiber cord for carcass ply Each cord having the cord structure shown in Table 1 consisting of the polyketone fiber (Examples 1 to 5) and the rayon fiber (Comparative Example 1) obtained in Production Example 1, After applying a one-bath type dip solution containing an RFL adhesive having the following composition, a drying step and a heat treatment step were performed, followed by a drying and curing treatment, to prepare a reinforcing fiber cord for carcass ply.
In addition, the twist coefficient N of the cord represented by N = n × (0.125 D / ρ) ^1/2 × 10 ⁻³ was 0.83. The number n of upper twists was 47 times / 10 cm, the total display decitex D was 3340 dtex, and the fiber density ρ was 1.33 g / cm ³ .
Moreover, the cord tension per one in the drying step and the heat treatment step, the drying treatment temperature in the drying step, the Tm / s in the heat treatment step, and the adhesive adhesion amount are as shown in Table 1.
<Composition of one bath type dip solution>
Resorcin and formaldehyde relative to the solids mass (L) of the total latex with a molar ratio (F / R) of formaldehyde (F) to resorcin (R) of about 2.0 (preferably 1.8 to 2.2) The ratio (RF / L) of the total mass (RF) is about 20% by mass (preferably 15 to 25% by mass), and the ratio of the solid content mass of the vinylpyridine (VP) latex in the total mass of latex solid content is About 41% by mass, the proportion of the solid content of styrene butadiene rubber (SBR) latex is about 40% by mass, and the molar ratio of sodium hydroxide to resorcin (R) (NaOH / R) is about 0.3. A bath-type dip solution was used.
(2) Manufacture and evaluation of pneumatic tires Radial tires for passenger cars with tire size 215 / 45ZR17 consisting of only one layer of carcass ply using the reinforcing fiber cord obtained in (1) above were manufactured in accordance with conventional methods, and run-flat durability The quality and ride comfort were evaluated. The results are shown in Table 1.
In the tires of Examples 1 to 5 and Comparative Example 1, the rubber composition A shown in Table 2 was used for the side reinforcing layer 8 and the bead filler 7. The reinforced rubber gauges of the side reinforcing layers 8 were all 5.7 mm. The number of reinforcing fiber cords constituting the carcass ply of any tire was 45/50 mm.

［注］
１）天然ゴム：ＴＳＲ２０
２）未変性ポリブタジエン：ＪＳＲ社製、ＢＲ０１
３）一級アミン変性ポリブタジエン：製造例２で得られたもの
４）ＤＭＢＴＥＳＰＡ変性ポリブタジエン：製造例３で得られたもの
５）カーボンブラック：ＦＥＦ（Ｎ５５０）、旭カーボン社製、商品名「旭＃６０」
６）プロセスオイル：アロマティックオイル、富士興産社製、商品名「アロマックス＃３」
７）老化防止剤６Ｃ：Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−ｐ−フェニレンジアミン、大内新興化学工業社製、商品名「ノクラック６Ｃ」
８）加硫促進剤ＤＺ：Ｎ，Ｎ’−ジシクロヘキシル−２−ベンゾチアジルスルフェンアミド、大内新興化学工業社製、商品名「ノクセラーＤＺ」
９）加硫促進剤ＴＯＴ：テトラキス（２−エチルへキシル）チウラムジスルフィド、大内新興化学工業社製、商品名「ノクセラーＴＯＴ−Ｎ」

[note]
1) Natural rubber: TSR20
2) Unmodified polybutadiene: manufactured by JSR, BR01
3) Primary amine-modified polybutadiene: obtained in Production Example 2 4) DMBTESPA-modified polybutadiene: obtained in Production Example 3 5) Carbon black: FEF (N550), manufactured by Asahi Carbon Co., Ltd., trade name “Asahi # 60” "
6) Process oil: Aromatic oil, manufactured by Fuji Kosan Co., Ltd., trade name “Aromax # 3”
7) Anti-aging agent 6C: N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “NOCRACK 6C”
8) Vulcanization accelerator DZ: N, N′-dicyclohexyl-2-benzothiazylsulfenamide, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “Noxeller DZ”
9) Vulcanization accelerator TOT: Tetrakis (2-ethylhexyl) thiuram disulfide, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “Noxeller TOT-N”

Examples 6-8
It consists of only one layer of carcass ply using the reinforcing fiber cord of Example 4 (the number of reinforcing fiber cords forming the carcass ply is 45/50 mm), and rubber compositions B to D in Table 2 are used as side reinforcing layers. No. 8 and radial tires for passenger cars having tire sizes of 215 / 45ZR17 of Examples 6 to 8 used for the bead filler 7 were manufactured according to a conventional method, and run-flat durability and riding comfort were evaluated. The results are shown in Table 3.
In addition, although the tire using the rubber composition A is a tire of Example 4, it re-displayed in Table 3 for the comparison with the tire of Examples 6-8. The reinforcing rubber gauge of the side reinforcing layer 8 is based on the values described in Table 3.

  In the pneumatic tire of the present invention, a reinforcing fiber cord containing polyketone fibers is applied to a carcass ply, and preferably, a rubber composition having a specific property is used as at least one of tire members, particularly a side reinforcing layer and / or By using the bead filler, run-flat durability can be improved without impairing rolling resistance and riding comfort during normal driving.

It is a mimetic diagram showing the section of one embodiment of the pneumatic tire of the present invention. It is explanatory drawing for calculating | requiring (SIGMA) tan (delta) (28-150 degreeC) in the vulcanized rubber physical property of a rubber composition.

Explanation of symbols

1, 1 'bead core 2 carcass layer 3 side rubber layer 4 tread rubber layer 5 belt layer 6 inner liner 7 bead filler 8 side reinforcing layer 10 shoulder area

Claims (21)

A pneumatic tire comprising a bead core, a carcass ply, a tread rubber layer, an inner liner, a side reinforcing layer, and a bead filler, wherein the reinforcing fiber cord constituting the carcass ply is coated with a resorcin / formaldehyde resin-rubber latex adhesive Later, the cord is a cord containing at least 50% by mass of polyketone fiber, which is dried and cured through a drying step and a heat treatment step, and the cord tension in the following condition (1) in the drying step and the heat treatment step is 2 .9-49.0 N
(2) The drying process temperature in the said drying process is 100-200 degreeC,
(3) When the curing temperature in the heat treatment step is Tm (° C.) and the curing time is s (seconds), Tm / s is 1.1 to 8.7,
A pneumatic tire characterized by satisfying   After the application of resorcin / formaldehyde resin-rubber latex adhesive, the adhesion amount of the reinforcing fiber cord formed by drying and curing is 1.5 to 9.0 mass% with respect to the mass of the cord before the treatment. The pneumatic tire according to claim 1. The pneumatic tire according to claim 1 or 2, wherein the reinforcing fiber cord constituting the carcass ply has a twist coefficient N represented by the following formula (1) satisfying a relationship of the following formula (2).
N = n × (0.125D / ρ) ^1/2 × 10 ⁻³ (1)
0.34 ≦ N (2)
[In the formula, n represents the number of upper twists (times / 10 cm), D represents the total display decitex, and ρ represents the density (g / cm ³ ) of the fiber containing at least 50% by mass of the polyketone fiber. ] The twist coefficient N is the following formula (2-a)
0.6 ≦ N ≦ 0.9 (2-a)
The pneumatic tire according to claim 3, satisfying the relationship:   The pneumatic tire according to any one of claims 1 to 4, wherein the number of reinforcing fiber cords constituting the carcass ply is 30 to 60/50 mm.   The pneumatic tire according to any one of claims 1 to 5, wherein the reinforcing fiber cord constituting the carcass ply is formed by twisting a filament bundle having a fineness of 500 to 2000 dtex. The polyketone constituting the polyketone fiber is represented by the following general formula (3)

[In formula, A shows the residue derived from the unsaturated compound superposed | polymerized by the unsaturated bond, and may be same or different in a repeating unit. ]
The pneumatic tire according to claim 1, having a repeating unit represented by:   The pneumatic tire according to claim 7, wherein A in the general formula (3) is an ethylene group.   (A) The rubber component and 100 parts by mass of the rubber component (B) include 55 parts by mass or more of carbon black, and in the physical properties of vulcanized rubber, the elastic modulus at 100% elongation (M100) is 10 MPa or more, and The pneumatic tire according to any one of claims 1 to 8, wherein a rubber composition having a sigma value of tan δ) at 28 to 150 ° C of 6.0 or less is used for at least one of the tire members.   The pneumatic tire according to claim 9, wherein in the rubber composition, (B) the carbon black is at least one selected from FEF grade, FF grade, HAF grade, ISAF grade and SAF grade.   The pneumatic tire according to claim 10, wherein (B) carbon black is FEF grade.   The pneumatic tire according to any one of claims 9 to 11, wherein in the rubber composition, (A) the rubber component contains an amine-modified conjugated diene polymer.   The pneumatic tire according to claim 12, wherein the amine-modified conjugated diene polymer is a protic amine-modified conjugated diene polymer.   The pneumatic tire according to claim 12 or 13, wherein the amine-modified conjugated diene polymer is a primary amine-modified conjugated diene polymer.   The pneumatic tire according to claim 14, wherein the primary amine-modified conjugated diene polymer is obtained by reacting a protected primary amine compound with an active terminal of the conjugated diene polymer.   The conjugated diene polymer is obtained by anionic polymerization of a conjugated diene compound alone or a conjugated diene compound and an aromatic vinyl compound in an organic solvent using an organic alkali metal compound as an initiator. The described pneumatic tire.   The pneumatic tire according to claim 16, wherein the conjugated diene polymer is polybutadiene.   The pneumatic tire according to any one of claims 15 to 17, wherein the protected primary amine compound is N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane.   The pneumatic tire according to claim 9, wherein the rubber composition is used for a side reinforcing layer.   The pneumatic tire according to claim 9, wherein the rubber composition is used as a bead filler.   The pneumatic tire according to claim 9, wherein the rubber composition is used for a side reinforcing layer and a bead filler.

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