JP5683067B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a rubber composition having a vulcanized rubber characteristic having an elastic modulus at 100% elongation of not less than a certain value and a tangent loss tan δ of not more than a certain Σ value at 28 ° C. to 150 ° C. It is used as a layer and / or bead filler, and while maintaining the air impermeability of the inner liner, it suppresses peeling between the side reinforcing rubber layer and the inner liner without impairing rolling resistance and riding comfort during normal driving The present invention relates to a pneumatic tire having improved run flat durability.

2. Description of the Related Art Conventionally, in a pneumatic tire, particularly a run-flat tire, a side reinforcing rubber layer made of a rubber composition alone or a composite of a rubber composition and fibers has been 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 provided with a side reinforcing rubber layer, the side reinforcing rubber layer and the bead filler exceed the breakage limit, resulting in a tire failure.
As a means of prolonging the time until such failure, the side wall portion of the tire can be obtained by highly blending sulfur into the rubber composition used for the side reinforcing rubber layer and the bead filler and making the rubber composition highly elastic. Although there is a technique for suppressing the deformation amount of the bead filler, there is a problem that the rolling resistance during normal running of the tire is increased and the fuel efficiency is lowered.

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

On the other hand, as means for earning the time until the failure, there is one that increases the volume of rubber, such as increasing the maximum thickness of the side reinforcing rubber layer and the bead filler to be disposed. In addition, undesirable situations such as deterioration of riding comfort during normal driving, an increase in weight, and an increase in noise level occur.
If the volume of the side reinforcing rubber 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, and the side wall portion of the tire at the time of run flat The deformation of the rubber composition becomes very large, which causes an increase in heat generation of the rubber composition, and as a result, there is a problem that the tire fails 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.

Furthermore, the side-reinforced run-flat tires have thicker side gauges than normal tires, so a rubber composition with a fast vulcanization rate is applied to the side-reinforced rubber layer to reduce productivity degradation. doing. However, when the vulcanization rate of the rubber composition for the side reinforcing rubber layer is increased, the difference in vulcanization rate between the side reinforcing rubber layer and the inner liner adjacent to the side reinforcing rubber layer increases. Sulfurability will decrease. As a result, the side reinforcing rubber layer and the inner liner easily peeled off during running (hereinafter referred to as run-flat running) in a state where the internal pressure of the tire has been lowered due to puncture or the like, and there was a problem in run-flat durability.
On the other hand, in order to suppress the peeling between the side reinforcing rubber layer and the inner liner, a blend of butyl rubber and natural rubber is generally used as the rubber component of the rubber composition for the inner liner. Although the vulcanization speed can be made relatively fast, the air impermeability of the inner liner is reduced, and further, there are problems such as a large change in physical properties of each member of the tire due to aging and a decrease in durability of the belt. It was.

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

  Under such circumstances, an object of the present invention is to provide a pneumatic tire with improved run-flat durability without impairing rolling resistance and riding comfort during normal driving.

As a result of intensive research to develop a pneumatic tire having the above-mentioned preferable properties, the present inventor has found that the vulcanized rubber properties have a modulus of elasticity at 100% elongation of not less than a certain value and a tangent loss tan δ of 28. Use a rubber composition having a Σ value below a certain value at -15 ° C. to 150 ° C., particularly for the side reinforcing rubber layer and / or bead filler, and further apply a rubber composition having a specific air permeability coefficient to the inner liner. Thus, it has been found that a pneumatic tire formed by maintaining the air impermeability of the inner liner can be adapted to the purpose. 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 layer, a tread rubber layer, an inner liner, a pair of crescent-shaped side reinforcing rubber layers, and a bead filler, wherein (A-1) the side reinforcing rubber layer and / or Alternatively, the bead filler rubber composition comprises (B) a rubber component and 100 parts by mass of (C) 55 parts by mass of carbon black, (B) the rubber component contains amine-modified polybutadiene, and the amine modified polybutadiene is the active end of the polybutadiene are those obtained at least one silane compound selected from alkoxysilane compounds having a protected primary amine compound and protected secondary amino group is reacted, and vulcanization In rubber properties, elastic modulus at 100% elongation (M100) is 10 MPa or more and tangent loss tan δ is 28 ° C. The rubber composition has a Σ value of 6.0 or less at 150 ° C. and the air permeability coefficient at 60 ° C. of the rubber composition used for the (A-2) inner liner is 6.0 × 10 ⁻¹⁰ cm ^3. a pneumatic tire characterized by being cm / cm ² · sec · cmHg or less,
[2] (A-1) In the rubber composition, the (C) carbon black is at least one selected from FEF grade, FF grade, HAF grade, ISAF grade and SAF grade. 1] pneumatic tire,
[3] (C) The pneumatic tire of the above [2], wherein the carbon black is FEF grade grade,
[4] The protected primary amine compound is 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) aminoethyltrimethoxy Protective one selected from silane, N, N-bis (trimethylsilyl) aminoethyltriethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane and N, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane An alkoxysilane compound having a secondary amino group, wherein the alkoxysilane compound having a protected secondary amino group is 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 (pyrrolidine) -2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (pyrrolidin-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (piperidin-2-yl) propyl (methyl) dimethoxysilane N-trimethylsilyl (piperidin-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (imidazol-2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (imidazol-2-yl) propyl (methyl) ) Diethoxysilane, N-trimethylsilyl (4,5-dihydroimidazol-5-yl) propyl (methyl) dimethoxysilane and N-trimethylsilyl (4,5-dihydroimidazol-5-yl) propyl (methyl) diethoxysilane The pneumatic tire according to any one of the above [1] to [3], which is an alkoxysilane compound having a protected secondary amino group ,
[5] The amine-modified polybutadiene, the active end of the polybutadiene, the pneumatic tire of the above-mentioned [1] is obtained by reacting the protected primary amine compound,
[6] the polybutadiene, the organic alkali metal compound as an initiator, either of a pneumatic tire of the above-mentioned [1] to [5] is obtained by a butadiene alone was subjected to anionic polymerization in an organic solvent,
[7] The protected primary amine compound, N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane and 1-trimethylsilyl-2,2-dimethoxy - The pneumatic tire according to any one of the above [4] to [6], which is an alkoxysilane compound having a protected primary amino group selected from 1-aza-2-silacyclopentane;
[ 8 ] The pneumatic tire according to any one of [1] to [7], wherein the rubber composition for an inner liner (A-2) contains butyl rubber as a rubber component.
[ 9 ] The pneumatic tire according to [ 8 ], wherein the rubber composition for an inner liner (A-2) has a butyl rubber content in the rubber component of 80% by mass or more.
[ 10 ] The above [1] to [ A-2], wherein the rubber composition for an inner liner is formed by blending 15 parts by mass or more of an inorganic filler having an aspect ratio of 5 to 30 with respect to 100 parts by mass of the rubber component . 9] any of the pneumatic tires,
[ 11 ] A vulcanization rate difference Δ represented by the following formula (I) between the rubber composition used for the (A-1) side reinforcing rubber layer and the rubber composition for the (A-2) inner liner is The pneumatic tire according to any one of [1] to [ 10 ] , which is 13.5 or less at a sulfur temperature of 160 ° C., and Δ = | {Tc (90) −Tc (10)} _I − {Tc (90) − Tc (10)} _S | (I)
(Wherein, Tc (90) is 90% vulcanization time (minute) of rubber composition, Tc (10) is 10% vulcanization time (minute) of rubber composition, and I is rubber composition for inner liner. S is a rubber composition for a side reinforcing rubber layer.)
[ 12 ] The pneumatic tire according to any one of [1] to [ 11 ] , wherein a peel resistance between the side reinforcing rubber layer and the inner liner is 5.0 N / mm or more.
Is to provide.

  According to the present invention, in the physical properties of vulcanized rubber, (A-1) rubber composition having a modulus of elasticity at 100% elongation of 10 MPa or more and a Σ value of tangent loss tan δ at 28 ° C. to 150 ° C. of 6.0 or less. Is used for the side reinforcing rubber layer and / or bead filler of the tire, and (A-2) the air impermeability of the inner liner is improved by applying a rubber composition having a specific air permeability coefficient to the inner liner. It is possible to provide a pneumatic tire with improved run-flat durability without impairing rolling resistance and riding comfort during normal running while maintaining.

[Pneumatic tire]
First, the pneumatic tire of the present invention will be described below with reference to the drawings. Drawing 1 is a mimetic diagram showing the section of one embodiment of the pneumatic tire of the present invention.
The tire shown in FIG. 1 has a pair of left and right bead portions 1 and a pair of sidewall portions 2 and a tread portion 3 connected to both sidewall portions 2, and extends in a toroidal shape between the pair of bead portions 1. A radial carcass 4 that reinforces each of these parts 1, 2, 3, a belt 5 composed of at least two belt layers arranged on the outer side in the tire radial direction of the carcass 4, and an inner side in the tire radial direction of the carcass 4 A pair of crescent-shaped side reinforcing rubber layers 7 arranged between the innermost side surface of the carcass 4 of the sidewall portion 2 and the inner liner 6, and the bead portion 1. And a bead filler 9 disposed on the outer side in the tire radial direction of each of the ring-shaped bead cores 8 embedded therein. In the illustrated tire, the radial carcass 4 includes a folded carcass ply 4a and a down carcass ply 4b, and both ends of the folded carcass ply 4a are folded around the bead core 8 to form folded ends. The structure and the number of plies of the radial carcass 4 are not limited to this. The (A-1) rubber composition according to the present invention is used for the side reinforcing rubber layer 7 and / or the bead filler 9 of the pneumatic tire, and the inner liner 6 (A-2) has a specific air permeability coefficient. By applying the composition, the pneumatic tire of the present invention can exhibit the above-described effects.

[Rubber composition]
((A-1) Rubber composition for side reinforcing rubber layer and / or bead filler)
In the above-described pneumatic tire of the present invention, the side reinforcing rubber layer 7 and / or the bead filler 9 (B-1) as a rubber composition (A-1) as a rubber composition and 100 parts by mass of (C) A rubber composition containing 55 parts by mass or more of carbon black and having a vulcanized rubber physical property of an elastic modulus at 100% elongation (M100) of 10 MPa or more and a tangent loss tan δ of Σ value at 28 ° C. to 150 ° C. of 6.0 or less. Can be used.
((B) 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, side chain and 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, as a primary amine-modified conjugated diene polymer modified with a primary amino group, a protected primary amine compound is reacted with the active terminal of the conjugated diene polymer. The obtained primary amine-modified conjugated diene polymer modified with a protected primary amino group 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 preferable.
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. As such a polymerization reaction having a living property, an organic alkali metal compound is used as an initiator, and a conjugated diene compound alone or a reaction in which an conjugated diene compound and an aromatic vinyl compound are anionically polymerized in an organic solvent, or an organic solvent. Among them, a conjugated diene compound alone or a reaction in which a conjugated diene compound and an aromatic vinyl compound are coordinated anionic polymerized by a catalyst containing a lanthanum series rare earth element compound can be mentioned. The former is preferable because a conjugated diene moiety having a higher vinyl bond content than the latter can be obtained. Heat resistance can be improved by increasing the amount of vinyl bonds.

  As the organic alkali metal compound used as an initiator for the above-mentioned anionic polymerization, an organic lithium compound is preferable. The organolithium 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 has polymerization activity. A conjugated diene polymer as a site 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 of initiating polymerization, cyclic lithium amides 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 organolithium 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, or 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 an organic lithium compound is used as a polymerization initiator, it has not only a conjugated diene polymer having an active end but also an active end, compared to the case of using a catalyst containing the lanthanum series rare earth element compound described above. A copolymer of a conjugated diene compound and an aromatic vinyl compound can also be obtained efficiently.

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 and 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 alone 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, oxolanyl propane oligomers [particularly 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 individually by 1 type, and may be used in combination of 2 or more types. 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 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 tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetra-n-butoxytitanium oligomer, tetra-sec- Butoxytitanium, tetra-tert-butoxytitanium, tetra (2-ethylhexyl) titanium, bis (octanediolate) bis (2-ethylhexyl) titanium, tetra (octanediolate) titanium, titanium lactate, titanium dipropoxybis (triethanol Aminate), titanium dibutoxybis (triethanolaminate), titanium tributoxy systemate, titanium tripropoxy systemate, titanium ethyl Sildiolate, Titanium tripropoxyacetylacetonate, Titanium dipropoxybis (acetylacetonate), Titanium tripropoxyethylacetoacetate, Titaniumpropoxyacetylacetonatebis (ethylacetoacetate), Titanium tributoxyacetylacetonate, Titanium dibutoxybis ( Acetylacetonate), titanium tributoxyethyl acetoacetate, titanium butoxyacetylacetonate bis (ethylacetoacetate), titanium tetrakis (acetylacetonate), titanium diacetylacetonate bis (ethylacetoacetate), bis (2-ethylhexanoate) Ate) 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 Examples thereof include compounds containing titanium such as (stearate) titanium, tetrakis (oleate) titanium, tetrakis (linoleate) titanium, and the like.

  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-ethylhexyl) 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 (2-1 ethylhexyl) aluminum, aluminum di Butoxy systemate, aluminum dibutoxyacetylacetonate, aluminum butoxybis (acetylacetonate), aluminum dibutoxyethylacetoacetate, aluminum tris (acetylacetonate), aluminum tris (ethylacetoacetate), tris (2-ethylhexanoate) Ate) 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.
The condensation reaction may be carried out in an aqueous solution, and the condensation reaction temperature is preferably 85 to 180 ° C, more preferably 100 to 170 ° C, and particularly preferably 110 to 150 ° C.
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 change over time of the resulting modified conjugated diene polymer can be 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 is no restriction | limiting in particular about the format in the case of performing a condensation reaction in aqueous solution, You may carry out by a continuous type using apparatuses, such as a batch type reactor and a multistage continuous type reactor. Moreover, you may perform this condensation reaction and a desolvent simultaneously.
The primary amino group derived from the modifying agent of the modified conjugated diene polymer of the present invention is generated by performing the 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 properties such as fracture resistance are not obtained, and when it exceeds 150, workability is poor and it is difficult to knead with the compounding agent.
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. is there.
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>
(B) 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 rubber. Examples of the other diene synthetic rubber 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. .

((C) 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 70 parts by mass, and more 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 the FEF grade grade is particularly preferable.

((A-1) Physical properties of vulcanized rubber of rubber composition)
The rubber composition (A-1) according to the present invention requires that the elastic modulus at 100% elongation (M100) is 10 MPa or more as physical properties of the vulcanized rubber. 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 property of the vulcanized rubber, the Σ value [Σtan δ (28 to 150 ° C.)] at 28 ° C. to 150 ° C. of the tangent loss tan δ is required to be 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.).

((A-2) Inner liner rubber composition)
In the pneumatic tire of the present invention, the air permeability coefficient at 60 ° C. of the rubber composition for an inner liner (A-2) is 6.0 × 10 ⁻¹⁰ cm ³ · cm ² · sec · cmHg or less. is necessary.

For the inner liner, a rubber composition having an air permeability coefficient at 60 ° C. of 6.0 × 10 ⁻¹⁰ cm ³ · cm / cm ² · sec · cmHg or less is applied, so that the air impermeability is lower than that of the conventional one. Maintained. Here, when the air permeability coefficient at 60 ° C. of the rubber composition for the inner liner exceeds 6.0 × 10 ⁻¹⁰ cm ³ · cm ² · sec · cmHg, the air impermeability of the inner liner is conventionally increased. Compared to the above, the air retention of the tire is deteriorated, the physical property change of each member of the tire is increased, and the durability of the belt is decreased. The air permeability coefficient at 60 ° C. of the rubber composition for the inner liner is 3.0 × 10 ⁻¹⁰ cm ³ · from the viewpoint of further improving the air retention of the tire and reliably suppressing the deterioration of the tire member over time. It is preferably cm / cm ² · sec · cmHg or less.

  Further, the peel resistance between the side reinforcing rubber layer and the inner liner is preferably 5.0 N / mm or more, and more preferably 5.5 N / mm or more. Thereby, peeling between the side reinforcing rubber layer and the inner liner is sufficiently suppressed, and the run-flat durability of the tire is improved.

  Rubber components of the rubber composition used for the inner liner include natural rubber (NR), butyl rubber (IIR), polybutadiene rubber (BR), styrene / butadiene copolymer rubber (SBR), and acrylonitrile / butadiene rubber (NBR). And synthetic rubbers such as chloroprene rubber (CR). The butyl rubber may be halogenated. These rubber components can be used alone or as a blend of two or more. Here, the rubber component of the rubber composition for the inner liner preferably contains butyl rubber, and when the rubber component of the rubber composition for the inner liner contains butyl rubber, the air impermeability of the rubber composition is improved. Can do. Further, from the viewpoint of reliably improving the air impermeability of the rubber composition for the inner liner, the content of butyl rubber in the rubber component of the rubber composition is more preferably 80% by mass or more.

  The rubber composition for an inner liner (A-2) is preferably formed by blending 15 parts by mass or more of an inorganic filler having an aspect ratio of 5 to 30 in a dispersed state with respect to 100 parts by mass of the rubber component. . A rubber composition obtained by blending a rubber component with a flat inorganic filler having an aspect ratio of 5 to 30 has high air impermeability because the flat inorganic filler inhibits air permeation. When the aspect ratio of the inorganic filler is less than 5, the effect of improving the air impermeability of the inner liner is small, and when it exceeds 30, the processability of the rubber composition is deteriorated. The aspect ratio of the flat inorganic filler is more preferably 5 to 20 from the viewpoint of improving the air impermeability of the inner liner and maintaining good processability of the rubber composition. Here, the aspect ratio refers to the ratio of the major axis to the thickness of the flat inorganic filler. Moreover, if the compounding quantity of the said flat inorganic filler is less than 15 mass parts with respect to 100 mass parts of rubber components, the effect which improves the air impermeability of the said inner liner will be small. From the viewpoint of reliably improving the air impermeability of the inner liner, the blending amount of the flat inorganic filler is more preferably 20 parts by mass or more with respect to 100 parts by mass of the rubber component. Although there is no restriction | limiting in particular about the upper limit, Usually, it is about 100 mass%.

  The flat inorganic filler is a layered or plate-like mineral and is not particularly limited as long as it has a flat aspect ratio of 5 to 30, and may be a natural product or a synthetic product. Examples of the mineral include water-containing composites of kaolin clay, mica, feldspar, silica and alumina, montmorillonite, saponite, hectorite, beidellite, stevensite, nontronite, vermiculite, halloysite and the like. Among these, kaolin clay and mica are preferable, and kaolin clay is particularly preferable. These minerals may be used individually by 1 type, may use 2 or more types together, and can use a commercial item suitably. In addition, it is preferable that the said flat inorganic filler has a particle size of 0.2-2 micrometers normally.

The vulcanization rate difference Δ represented by the following formula (I) between the rubber composition for the side reinforcement rubber layer (A-1) and the rubber composition for the inner liner (A-2) is a vulcanization temperature of 160 ° C. Is preferably 13.5 or less.
Δ = | {Tc (90) −Tc (10)} _I − {Tc (90) −Tc (10)} _S | (I)
(Wherein, Tc (90) is 90% vulcanization time (minute) of rubber composition, Tc (10) is 10% vulcanization time (minute) of rubber composition, and I is rubber composition for inner liner. S is a rubber composition for a side reinforcing rubber layer.)
When the difference in vulcanization rate Δ at 160 ° C. between the rubber composition for the side reinforcing rubber layer and the rubber composition for the inner liner exceeds 13.5, the co-vulcanizability between the side reinforcing rubber layer and the inner liner decreases. As a result, the side reinforcing rubber layer and the inner liner easily peel off during run flat running, and the run flat durability of the tire is reduced. Here, from the viewpoint of further improving the run-flat durability of the tire, the vulcanization speed difference Δ is more preferably 13 or less at 160 ° C. The vulcanization speed can be appropriately changed by adjusting the types and amounts of vulcanizing agent, vulcanization accelerator, filler and other compounding agents.

In addition to the rubber component and the flat inorganic filler described above, the rubber composition according to the present invention is further included in the rubber composition for the side reinforcement rubber layer (A-1) and the rubber composition for the inner liner (A-2). As long as the effect of the present invention is not impaired, various chemicals usually used in the rubber industry, for example, vulcanizing agents, vulcanization accelerators, process oils, anti-aging agents, scorch inhibiting agents, zinc oxides, are used as desired. , 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), a high-temperature condensate of diphenylamine and acetone, and the like.

(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 rubber layer 7 and / or a bead filler 9 and an inner liner 6 of a pneumatic tire.
The tire of the present invention is a normal run-flat tire manufactured by using the rubber composition (A-1) according to the present invention for the side reinforcing rubber layer 7 and / or the bead filler 9 and (A-2) for the inner liner. Manufactured by the method. That is, as described above, the rubber composition according to the present invention containing various chemicals is processed into each member at an unvulcanized stage, and pasted and molded by a normal method on a tire molding machine, and a raw tire is molded. Is done. The green tire is heated and pressed in a vulcanizer to obtain a tire.
The pneumatic tire of the present invention thus obtained has low air permeability and 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)>
It measured using GPC [The Tosoh make, HLC-8020] using the refractometer as a detector, and showed it by polystyrene conversion which used the monodisperse polystyrene as a standard. The column is GMHXL [manufactured by Tosoh] and the eluent is tetrahydrofuran.

<Measurement of primary amino group content (mmol / kg)>
First, the polymer was dissolved in toluene, and then the amino group-containing compound not bound to the polymer was separated from the rubber by precipitation in a large amount of methanol, followed by drying. Using this treated polymer as a sample, the total amino group content was quantified by the “total amine value test method” described in JIS K7237. Subsequently, the contents of secondary amino groups and tertiary amino groups were quantified by the “acetylacetone blocked method” using the polymer subjected to the above treatment as a sample. As a solvent for dissolving the sample, o-nitrotoluene was used, acetylacetone was added, and potentiometric titration was performed with a perchloracetic acid solution. The primary amino group bound to the polymer by subtracting the secondary amino group content and tertiary amino group content from the total amino group content to determine the primary amino group content (mmol) and dividing by the polymer mass used in the analysis. The content (mmol / kg) was determined.

<< Physical properties of vulcanized rubber of rubber composition >>
1). The Σ value at 28 ° C. to 150 ° C. [Σ tan δ (28 to 150 ° C.)] of the 100% elastic modulus (M100) and the tangent loss tan δ was measured according to the method described in the specification.
2). Vulcanization speed Based on JIS K6300-2: 2001, the vulcanization curve of the rubber composition was measured at 160 ° C. using a curast meter manufactured by JSR Corporation. The maximum value (Fmax) and minimum value (Fmin) of the torque in the vulcanization curve are measured, and the time (min) until the torque reaches {(Fmax−Fmin) × 0.1 + Fmin} is determined as 10% vulcanization time (Tc (10)), the time (min) until reaching the torque of {(Fmax−Fmin) × 0.9 + Fmin} is defined as 90% vulcanization time (Tc (90)), and the difference between did.
3). Air Permeability Coefficient For each sample obtained by vulcanizing each rubber composition at 160 ° C. for 30 minutes, the air permeability coefficient at 60 ° C. was measured using an air permeation tester M-C1 (manufactured by Toyo Seiki Co., Ltd.) did.
4). The peeling resistance side reinforcing rubber layer and the inner liner were bonded together and vulcanized to prepare a strip-shaped sample having a width of 20 mm. A peel test was performed at the interface between the side reinforcing rubber layer and the inner liner of the sample, and the force generated at that time was measured.

<< Evaluation of pneumatic tire >>
1). Run-flat durability Each test tire (passenger car radial tire of tire size 215 / 45ZR17) is assembled at rim, filled with 230kPa of internal pressure, left in a room at 38 ℃ for 24 hours, and then the valve core is removed. The drum running test was performed under the conditions of an internal pressure of atmospheric pressure, 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 4 was set to 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 4) × 100
2). Ride Comfort Each test tire was mounted on a passenger car, and a feeling test of ride comfort was conducted by two professional drivers, and a score of 1-10 was assigned to obtain an average value. The larger the value, the better the ride comfort.
3). Internal pressure retention After mounting the test tire on the rim, the internal pressure was filled with 240 kPa, and the internal pressure after 3 months was measured with a pressure gauge. The reciprocal of the decrease rate was indexed with Comparative Example 1 as 100.

Production Example 1 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%. This 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 2 DMBTESPA Modified Polybutadiene In Production Example 1, 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 1, except that the amount was changed to 3.364 mmol.

(A-1) Preparation and Evaluation of Rubber Composition for Side Reinforced Rubber Layer and / or Rubber Composition for Bead Filler Three types of rubber compositions having the compounding compositions of Compositions A to C shown in Table 1 are used as usual methods. The vulcanized rubber properties, that is, the values of M100, Σtan δ (28 to 150 ° C.), and TS were obtained. The measurement results are shown in Table 1.

［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１で得られたもの
＊４．ＤＭＢＴＥＳＰＡ変性ポリブタジエン：製造例２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「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「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「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「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「ノクセラーＴＯＴ−Ｎ」

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

(A-2) Preparation and Evaluation of Rubber Composition for Inner Liner Four types of rubber compositions having the compounding compositions of Compositions D to G shown in Table 2 were prepared by ordinary methods, and vulcanized rubber properties, TI and air permeability coefficient values were determined. The evaluation results are shown in Table 2.

［注］
＊１０．［ブロモブチル］、ＪＳＲ社製
＊１１．［ＰＯＬＹＦＩＬＥ ＤＬ］、Ｊ．Ｍ．Ｈｕｂｅｒ社製、アスペクト比＝１５
＊１２．［日石ネオレジン］新日本石油化学社製
＊１３．２，２’−ジベンゾチアジルジスルフィド、大内新興化学工業社製［ノックセラーＤＭ−Ｐ」

[note]
* 10. [Bromobutyl], manufactured by JSR * 11. [POLYFILE DL], J.A. M.M. Huber, aspect ratio = 15
* 12. [Nisseki Neoresin] * 13.2,2'-dibenzothiazyl disulfide manufactured by Shin Nippon Petrochemical Co., Ltd. [Knock Cellar DM-P]

Examples 1-11 and Comparative Examples 1-8
19 types in total of Examples 1 to 11 and Comparative Examples 1 to 8 according to combinations of (A-1) compositions, (A-2) compositions and inner liner gauges shown in Table 3 and Table 2 A radial tire for passenger cars having a tire size of 215 / 45ZR17 was manufactured according to a conventional method, and the internal pressure retention property, the vulcanization speed difference, the peel resistance, and the run-flat durability were evaluated. The respective evaluation results are shown in Table 3-1 and Table 3.

The following can be seen from Table 3 and Table 3.
It can be seen that the run-flat durability of the tire of the comparative example using a rubber composition having Σtanδ (28 to 150 ° C.) of 6 or more as the side reinforcing rubber is greatly reduced.
In addition, a light weight tire with a thin inner liner gauge and excellent peeling resistance exhibits excellent run-flat durability. (Example 6 to Example 11)

  The tire of the present invention has a vulcanized rubber property (A-1) rubber composition having an elastic modulus at 100% elongation of 10 MPa or more and a tangent loss tan δ of Σ value at 28 ° C. to 150 ° C. of 6.0 or less. And (A-2) a rubber composition having a specific air permeability coefficient is applied to the inner liner, and the side reinforcing rubber layer and the inner liner By making the peel resistance of the specific range, it is possible to make the inner liner thinner gauge, while maintaining the air impermeability of the inner liner and without impairing the rolling resistance and riding comfort during normal driving, It is possible to provide a lightweight pneumatic tire with improved run-flat durability.

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

DESCRIPTION OF SYMBOLS 1 Bead part 2 Side wall part 3 Tread part 4 Radial carcass 4a Folded carcass ply 4b Down carcass ply 5 Belt 6 Inner liner 7 Side reinforcement rubber layer 8 Bead core 9 Bead filler

Claims (12)

A pneumatic tire comprising a bead core, a carcass layer, a tread rubber layer, an inner liner, a pair of crescent-shaped side reinforcing rubber layers and a bead filler, the (A-1) side reinforcing rubber layer and / or bead filler The rubber composition for (B) contains (B) a rubber component and 100 parts by mass of (C) carbon black of 55 parts by mass or more, (B) the rubber component contains amine-modified polybutadiene, and the amine-modified polybutadiene contains And obtained by reacting at least one silane compound selected from an alkoxysilane compound having a protected primary amine compound and a protected secondary amino group at the active terminal of polybutadiene, and in physical properties of vulcanized rubber The elastic modulus at 100% elongation (M100) is 10 MPa or more and the tangent loss tanδ is 28 ° C. to 150 With Σ value is 6.0 or less of the rubber composition in the (A-2) an air permeability coefficient at 60 ° C. of the rubber composition used in the inner liner ^{6.0 × 10 -10 cm 3 · cm} / A pneumatic tire characterized by being less than cm ² · sec · cmHg.   (A-1) In the rubber composition, (C) carbon black is at least one selected from FEF grade, FF grade, HAF grade, ISAF grade and SAF grade. Pneumatic tires.   The pneumatic tire according to claim 2, wherein (C) the carbon black is FEF grade grade. The protected primary amine compound is 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 Protected primary amino selected from N, N-bis (trimethylsilyl) aminoethyltriethoxysilane, N, N-bis (trimethylsilyl) aminoethylmethyldimethoxysilane and N, N-bis (trimethylsilyl) aminoethylmethyldiethoxysilane An alkoxysilane compound having an amino group, an alkoxysilane compound having a protected secondary amino group, N- methyl -N- trimethylsilyl aminopropyl (methyl) dimethoxysilane, N- methyl -N- trimethylsilyl aminopropyl (methyl ) Diethoxysilane, N-trimethylsilyl (hexamethyleneimin-2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (hexamethyleneimin-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (pyrrolidine- 2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (pyrrolidin-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (piperidin-2-yl) propyl (methyl) dimethoxysilane, -Trimethylsilyl (piperidin-2-yl) propyl (methyl) diethoxysilane, N-trimethylsilyl (imidazol-2-yl) propyl (methyl) dimethoxysilane, N-trimethylsilyl (imidazol-2-yl) propyl (methyl) diethoxy Protection selected from silane, N-trimethylsilyl (4,5-dihydroimidazol-5-yl) propyl (methyl) dimethoxysilane and N-trimethylsilyl (4,5-dihydroimidazol-5-yl) propyl (methyl) diethoxysilane The pneumatic tire according to any one of claims 1 to 3, which is an alkoxysilane compound having a secondary amino group. Wherein the amine-modified polybutadiene, the active end of the polybutadiene, the pneumatic tire according to claim 1 wherein the protected primary amine compound is obtained by reacting. The polybutadiene pneumatic tire according to claim 1 the organic alkali metal compound as an initiator, is obtained by a butadiene alone was subjected to anionic polymerization in an organic solvent. The protected primary amine compound is N, N-bis (trimethylsilyl) aminopropylmethyldimethoxysilane, N, N-bis (trimethylsilyl) aminopropylmethyldiethoxysilane and 1-trimethylsilyl-2,2-dimethoxy-1-aza. The pneumatic tire according to any one of claims 4 to 6 , which is an alkoxysilane compound having a protected primary amino group selected from -2-silacyclopentane. The pneumatic tire according to any one of claims 1 to 7 , wherein the rubber composition for (A-2) inner liner contains butyl rubber as a rubber component. The pneumatic tire according to claim 8 , wherein the rubber composition for an inner liner (A-2) has a butyl rubber content in a rubber component of 80% by mass or more. Wherein (A-2) a rubber composition for an inner liner, an aspect ratio per 100 parts by mass of the rubber component is 5 to 30 inorganic filler to any one of claims 1 to 9, by blending 15 parts by mass or more The described pneumatic tire. The vulcanization speed difference Δ represented by the following formula (I) between the rubber composition used for the (A-1) side reinforcing rubber layer and the rubber composition for the (A-2) inner liner is a vulcanization temperature of 160. The pneumatic tire according to any one of claims 1 to 10 , which is 13.5 or less at ° C.
Δ = | {Tc (90) −Tc (10)} _I − {Tc (90) −Tc (10)} _S | (I)
(Wherein, Tc (90) is 90% vulcanization time (minute) of rubber composition, Tc (10) is 10% vulcanization time (minute) of rubber composition, and I is rubber composition for inner liner. S is a rubber composition for a side reinforcing rubber layer.) The pneumatic tire according to any one of claims 1 to 11 , wherein a peel resistance between the side reinforcing rubber layer and the inner liner is 5.0 N / mm or more.

Images