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WO2020075830A1 - Composition de caoutchouc, bande de roulement, composition de caoutchouc pour bande de roulement de base, et pneumatique - Google Patents

Composition de caoutchouc, bande de roulement, composition de caoutchouc pour bande de roulement de base, et pneumatique Download PDF

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Publication number
WO2020075830A1
WO2020075830A1 PCT/JP2019/040136 JP2019040136W WO2020075830A1 WO 2020075830 A1 WO2020075830 A1 WO 2020075830A1 JP 2019040136 W JP2019040136 W JP 2019040136W WO 2020075830 A1 WO2020075830 A1 WO 2020075830A1
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WO
WIPO (PCT)
Prior art keywords
mass
rubber
parts
rubber composition
group
Prior art date
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Ceased
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PCT/JP2019/040136
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English (en)
Japanese (ja)
Inventor
健太郎 熊木
香奈 三重野
悟士 石川
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bridgestone Corp
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Bridgestone Corp
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Publication of WO2020075830A1 publication Critical patent/WO2020075830A1/fr
Anticipated expiration legal-status Critical
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
    • C08K3/013—Fillers, pigments or reinforcing additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/34—Silicon-containing compounds
    • C08K3/36—Silica
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L15/00—Compositions of rubber derivatives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
    • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
    • C08L23/18—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
    • C08L23/20—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms having four to nine carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L7/00—Compositions of natural rubber
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
    • Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction 

Definitions

  • the present invention relates to a rubber composition, a tread, a rubber composition for a base tread, and a tire.
  • Patent Document 1 a technique in which a rubber composition in which an aromatic oil is mixed with a rubber component such as natural rubber (NR) or butadiene rubber (BR) is used as a tread rubber. Further, in order to improve grip performance on a wet road surface, 5 to 50 parts by mass of a C 5 resin is blended with 100 parts by mass of a rubber component containing a total of 30% by mass or more of natural rubber and / or polyisoprene rubber. There is also known a technique of using a rubber composition obtained from the above as a tread rubber (Patent Document 2).
  • Patent Document 3 For the purpose of achieving both wet performance and low rolling resistance of the tire, a rubber component containing 70% by mass or more of natural rubber is blended, and a thermoplastic resin is added to 100 parts by mass of the rubber component.
  • a technique in which 5 to 50 parts by mass and 20 to 120 parts by mass of a silica-containing filler are compounded, and a rubber composition in which the silica content in the filler is 50 to 100% by mass is used for a tread rubber is also available. It is known (Patent Document 3 below). It has been found that the technique of Patent Document 3 described above makes it possible to achieve both wet performance and low rolling resistance of the tire. However, as performance required for next-generation tires, it is required that these performances can be maintained for a long period of time. In particular, regarding the wet performance, there is a problem that the rubber becomes hard and the wet performance deteriorates with the passage of time immediately after the production.
  • the rubber that makes up the base of the tire tread (hereinafter referred to as the "base tread") is also required to have low rolling resistance and durability, and the wet performance when the base tread is exposed for some reason. It has been desired that the wet performance can be maintained for a long time.
  • an object of the present invention is to provide a rubber composition which, when applied to a tire, can achieve both high levels of wet performance, low rolling resistance and steering stability, while maintaining wet performance for a long period of time. .
  • Another object of the present invention is to provide a tread and a tire which are excellent in wet performance, low rolling resistance and steering stability, and can maintain wet performance for a long time.
  • another object of the present invention is to provide a rubber composition for a base tread, which, when applied to a tire, can achieve both low rolling resistance, durability and wet performance, and can maintain wet performance for a long period of time. is there.
  • the gist of the present invention which solves the above problems is as follows.
  • the rubber composition of the present invention comprises a rubber component containing a modified styrene-butadiene rubber having a modifying group containing at least one atom selected from nitrogen and silicon in the molecule, A filler containing 40 parts by mass or more and less than 70 parts by mass of silica based on 100 parts by mass of the rubber component; A polyolefin softener having a weight average molecular weight (Mw) of 5,000 to 50,000 and 3 to 35 parts by weight based on 100 parts by weight of the rubber component; It is characterized by including.
  • Mw weight average molecular weight
  • the modifying group of the modified styrene-butadiene rubber preferably contains nitrogen and silicon, more preferably nitrogen and alkoxysilane. This is because when applied to a tire, the wet performance can be further improved and can be maintained for a longer period of time.
  • the polyolefin-based softening agent contains unmodified polybutene. This is because when applied to tires, the wet performance can be maintained for a longer period of time.
  • the rubber component further contains natural rubber, and the content ratio of the natural rubber in the rubber component is 10 to 70% by mass. This is because when applied to a tire, the wet performance can be further improved and can be maintained for a longer period of time.
  • the modified styrene-butadiene rubber preferably has a bound styrene content of 30% by mass or more. This is because when applied to a tire, the wet performance can be further improved and can be maintained for a longer period of time.
  • the silica is A mercury porosimeter based on the mercury porosimetry method was applied to silica having pores with an opening on the outer surface having an ink bottle-like pore index (IB) of 1.2 ⁇ 10 5 nm to 6 nm in diameter.
  • IB ink bottle-like pore index
  • Is the value obtained by Cetyltrimethylammonium bromide adsorption specific surface area (CTAB) (m 2 / g) and the ink bottle-like pore index (IB) are represented by the following formula (1); IB ⁇ ⁇ 0.36 ⁇ CTAB + 86.8 (1) It is preferable to satisfy the following. This is because when applied to a tire, the wet performance can be further improved and the wear resistance can also be improved.
  • the total content of the softening agent contained in the rubber composition is preferably 10 to 35 parts by mass with respect to 100 parts by mass of the rubber component. This is because when applied to a tire, the wet performance can be further improved and can be maintained for a longer period of time, and the reduction in steering stability and wear resistance can be suppressed.
  • the rubber composition of the present invention further contains 1 to 70 parts by mass of the thermoplastic resin with respect to 100 parts by mass of the rubber component. This is because when it is applied to a tire, the wet performance can be further improved and the reduction in steering stability can be suppressed.
  • the tread of the present invention is characterized by using the above-mentioned rubber composition of the present invention.
  • the rubber composition for the base tread of the present invention Rubber component, 5 parts by mass or more and 80 parts by mass or less of a filler with respect to 100 parts by mass of the rubber component, A polyolefin softener having a weight average molecular weight (Mw) of 5,000 to 50,000 and 3 to 35 parts by weight based on 100 parts by weight of the rubber component; It is characterized by including.
  • Mw weight average molecular weight
  • the filler contains at least carbon black. This is because when applied to a tire, the durability can be further enhanced.
  • the weight average molecular weight (Mw) of the polyolefin softener is preferably 6000 to 12,000. This is because when applied to a tire, the wet performance can be further improved and can be maintained for a longer period of time.
  • the tire of the present invention is characterized by using the above-described rubber composition of the present invention or the rubber composition for a base tread of the present invention.
  • the wet performance, the low rolling resistance and the steering stability are excellent, and the wet performance can be maintained for a long period of time.
  • a rubber composition which, when applied to a tire, can achieve a high level of wet performance, low rolling resistance, and steering stability while maintaining wet performance for a long period of time. Further, according to the present invention, it is possible to provide a tread and a tire which are excellent in wet performance, low rolling resistance and steering stability, and can maintain wet performance for a long period of time. Further, according to the present invention, it is possible to provide a rubber composition for a base tread which, when applied to a tire, can achieve both low rolling resistance, durability and wet performance, and can maintain wet performance for a long time.
  • the rubber composition of the present invention comprises a rubber component containing a modified styrene-butadiene rubber having a modifying group containing at least one atom selected from nitrogen and silicon in the molecule, A filler containing 40 parts by mass or more and less than 70 parts by mass of silica based on 100 parts by mass of the rubber component; A polyolefin softener having a weight average molecular weight (Mw) of 5,000 to 50,000 and 3 to 35 parts by weight based on 100 parts by weight of the rubber component; It is characterized by including.
  • Mw weight average molecular weight
  • a styrene-butadiene rubber having a modifying group containing a nitrogen atom or a silicon atom is used as the rubber component, and a certain amount of silica is used as a filler, so that the rubber composition is applied to a tire.
  • a styrene-butadiene rubber having a modifying group containing a nitrogen atom or a silicon atom is used as the rubber component, and a certain amount of silica is used as a filler, so that the rubber composition is applied to a tire.
  • the rubber composition stays in the rubber for a long time to give a softening effect. Therefore, it is possible to maintain the wet performance for a long time as compared with the conventional one (hereinafter, it may be referred to as “long-lasting wet performance”).
  • Mw weight average molecular weight
  • the tire of the present invention has a modified styrene-butadiene rubber having a modifying group containing at least one atom selected from nitrogen and silicon in the molecule (hereinafter referred to as "modified styrene-butadiene rubber (A1)” or “modified SBR (A1)".
  • a rubber component containing a rubber component is included.
  • the amount of bound styrene of the modified styrene-butadiene rubber (A1) is preferably 30% by mass or more, and more preferably 35% by mass or more, from the viewpoint of improving the wet performance of the tire and the durability of the wet performance. More preferably, it is still more preferably 39 mass% or more.
  • the amount of bound styrene of the modified styrene-butadiene rubber (A1) is preferably 60% by mass or less, and more preferably 50% by mass or less from the viewpoint of maintaining low rolling resistance.
  • the amount of bound styrene of the modified styrene-butadiene rubber (A1) can be measured by ultraviolet absorption of a phenyl group, and the amount of bound conjugated diene can also be determined from this. Specifically, it measures according to the following. Using the modified styrene-butadiene rubber (A1) as a sample, 100 mg of the sample is made up to 100 mL with chloroform and dissolved to obtain a measurement sample.
  • the amount of bound styrene (% by mass) with respect to 100% by mass of the sample is measured by the amount of ultraviolet absorption wavelength (near 254 nm) absorbed by the phenyl group of styrene (Shimadzu Corporation's spectrophotometer "UV-2450"). .
  • the content ratio of the modified styrene-butadiene rubber (A1) in the rubber component is preferably 40% by mass or more, and more preferably 60% by mass or more.
  • the content ratio of the modified styrene-butadiene rubber (A1) in the rubber component is preferably 90% by mass or less, and more preferably 80% by mass or less.
  • the modified styrene-butadiene rubber (A1) contained in the rubber component is not particularly limited as long as it is a modified styrene-butadiene rubber having a modifying group containing at least one atom selected from nitrogen and silicon in the molecule.
  • the modified styrene-butadiene rubber (A1) has a weight average molecular weight of 20 ⁇ 10 4 to 300 ⁇ 10 4 , and a molecular weight of 200 ⁇ 10 4 to 500 ⁇ 10 4 with respect to the total amount of the modified styrene-butadiene rubber.
  • modified styrene-butadiene rubber (A1-1) (hereinafter referred to as “modified styrene-butadiene rubber (A1-1) containing 0.25 to 30 mass% of the modified styrene-butadiene rubber” and having a shrinkage factor (g ′) of less than 0.64.
  • A1-1) "or" modified SBR (A1-1) ") can be used.
  • the weight average molecular weight (Mw) of the modified SBR (A1-1) is preferably 20 ⁇ 10 4 to 300 ⁇ 10 4 , more preferably 50 ⁇ 10 4 or more, 64 ⁇ 10 4 or more, or 80 ⁇ . It is 10 4 or more. Further, the Mw is preferably 250 ⁇ 10 4 or less, 180 ⁇ 10 4 or less, or 150 ⁇ 10 4 or less.
  • Mw of the modified SBR (A1-1) is 20 ⁇ 10 4 or more, the tire dry performance, steering stability, and low rolling resistance can be highly compatible.
  • Mw is 300 ⁇ 10 4 or less, the processability of the rubber composition is improved.
  • the number average molecular weight, the weight average molecular weight, the molecular weight distribution, and the content of a specific high molecular weight component described later of the modified SBR (A1-1) are measured as follows. RI detection using a modified SBR as a sample and a GPC (gel permeation chromatography) measuring device (trade name “HLC-8320GPC” manufactured by Tosoh Corporation) in which three columns with polystyrene gel as a packing material are connected.
  • GPC gel permeation chromatography
  • Chromatogram was measured using a vessel (trade name “HLC-8020” manufactured by Tosoh Corporation), and based on a calibration curve obtained using standard polystyrene, the weight average molecular weight (Mw) and number average molecular weight (Mn) And molecular weight distribution (Mw / Mn), modified SBR peak top molecular weight (Mp 1 ), styrene butadiene rubber peak top molecular weight (Mp 2 ) and its ratio (Mp 1 / Mp 2 ), and molecular weight 200 ⁇ 10 4 The ratio of 500 ⁇ 10 4 modified SBR and As an eluent, THF (tetrahydrofuran) containing 5 mmol / L triethylamine is used.
  • THF tetrahydrofuran
  • TSKgel SuperMultipore HZ-H (trade name, manufactured by Tosoh Corporation) are connected, and a guard column is connected to a column (trade name, TSKguardcolumn SuperMP (HZ) -H, manufactured by Tosoh Corporation) connected as a guard column.
  • 10 mg of a sample for measurement is dissolved in 10 mL of THF to prepare a measurement solution, 10 ⁇ L of the measurement solution is poured into a GPC measuring device, and measurement is performed under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.
  • the peak top molecular weights (Mp 1 and Mp 2 ) are determined as follows. In a GPC curve obtained by measurement, a peak detected as a component having the highest molecular weight is selected. For the selected peak, the molecular weight corresponding to the maximum value of the peak is calculated and used as the peak top molecular weight.
  • the modified SBR has a molecular weight of 200 ⁇ 10 4 to 500 ⁇ 10 4 with respect to the total amount (100% by mass) of the modified SBR (A1-1) (in the present specification, “specific high molecular weight”). 0.25 to 30% by mass.
  • the ratio of the modified SBR having a molecular weight of 200 ⁇ 10 4 to 500 ⁇ 10 4 is calculated by subtracting the ratio of the molecular weight of less than 200 ⁇ 10 4 from the ratio of the total molecular weight of 500 ⁇ 10 4 or less from the integral molecular weight distribution curve. To do.
  • the modified SBR (A1-1) has a specific high molecular weight component of 1.0 mass% or more, 1.4 mass% or more, 1.75 mass% or more, 2.0 mass% or more, 2. 15 mass% or more, or 2.5 mass% or more is contained.
  • the component comprises a particular high molecular weight component of 28 wt% or less, 25 wt% or less, 20 wt% or less, or 18 wt% or less.
  • the “molecular weight” is a standard polystyrene equivalent molecular weight obtained by GPC.
  • the reaction conditions in the polymerization step and reaction step described later it is preferable to control the reaction conditions in the polymerization step and reaction step described later.
  • the amount of an organic monolithium compound to be described later used as a polymerization initiator may be adjusted.
  • a method having a residence time distribution may be used in any of the continuous and batch polymerization modes, that is, the time distribution of the growth reaction may be broadened.
  • the modified SBR (A1-1) has a molecular weight distribution (Mw / Mn) of 1.6 to 3.0.
  • the contraction factor (g ′) of the modified SBR (A1-1) is preferably less than 0.64.
  • a polymer having a branch tends to have a smaller molecular size when compared with a linear polymer having the same absolute molecular weight, and the shrinkage factor (g ′) is assumed to be the same.
  • the intrinsic viscosity is used as an index of the size of the molecule
  • the contraction factor (g ') at each absolute molecular weight of the modified SBR is calculated, and the average value of the contraction factors (g') when the absolute molecular weight is 100 ⁇ 10 4 to 200 ⁇ 10 4 is calculated as the contraction of the modified SBR.
  • the "branch” is formed by directly or indirectly binding one polymer to another polymer.
  • the “branching degree” is the number of polymers directly or indirectly bonded to one branch.
  • the degree of branching is 5 when the below-mentioned five styrene-butadiene rubber chains are indirectly bonded to each other via a coupling residue described below.
  • the coupling residue is a structural unit of modified SBR that is bonded to a styrene-butadiene rubber chain, and is derived from a coupling agent, for example, which is generated by reacting a styrene-butadiene rubber described below with a coupling agent. It is a structural unit.
  • the styrene-butadiene rubber chain is a constitutional unit of the modified SBR, and is, for example, a structural unit derived from a conjugated diene polymer, which is generated by reacting a styrene-butadiene rubber described below with a coupling agent.
  • the contraction factor (g ') is, for example, 0.63 or less, 0.60 or less, 0.59 or less, or 0.57 or less.
  • the lower limit of the shrinkage factor (g ′) is not particularly limited, and may be equal to or less than the detection limit value, for example, 0.30 or more, 0.33 or more, 0.35 or more, 0.45 or more, and .0. It is 57 or more, or 0.59 or more.
  • the processability of the rubber composition is improved by using the component having the contraction factor (g ') in this range.
  • the shrinkage factor (g') tends to depend on the degree of branching, for example, the shrinkage factor (g ') can be controlled using the degree of branching as an index. Specifically, when a modified SBR having a degree of branching of 6 has a contraction factor (g ′) of 0.59 to 0.63, a modified SBR having a degree of branching of 8 is used. In that case, the contraction factor (g ′) tends to be 0.45 to 0.59.
  • the measuring method of the contraction factor (g ′) is as follows. Using the modified SBR (A1-1) as a sample, using a GPC measurement device (trade name "GPCmax VE-2001" manufactured by Malvern Co., Ltd.) in which three columns having a polystyrene gel as a filler are connected, light scattering detection is performed. , RI detector, viscosity detector (Malvern's trade name "TDA305”) are connected in this order using three detectors, and based on standard polystyrene, a light scattering detector and RI detector are used. The absolute molecular weight is obtained from the results of the detector and the intrinsic viscosity is obtained from the results of the RI detector and the viscosity detector.
  • the eluent uses THF containing 5 mmol / L triethylamine.
  • the product names “TSKgel G4000HXL”, “TSKgel G5000HXL”, and “TSKgel G6000HXL” manufactured by Tosoh Corporation are connected and used.
  • the amount of extender oil added to the modified SBR (A1-1) is preferably 10 parts by mass or less based on 100 parts by mass of the modified SBR (A1-1). More preferably, it is more than 0 parts by mass and 10 parts by mass or less.
  • the amount of the extension oil is 10 parts by mass or less, it is possible to highly balance the wet performance of the tire with the low rolling resistance and the steering stability.
  • the amount of the extending oil added is 10 parts by mass or less with respect to 100 parts by mass of the modified SBR, it is possible to obtain an oil-extended polymer to which the extending oil is added. It may be an oil exhibition.
  • Examples of the extender oil include aroma oil, naphthene oil, paraffin oil, aroma substitute oil and the like.
  • an aroma substitute oil containing 3% by mass or less of a polycyclic aromatic (PCA) component by the IP346 method is preferable.
  • aroma substitute oils include TDAE (Treated Distilate Aromatic Extracts), MES (Mild Extraction, and others such as Mild Extract, Aerosert, Aerosol, etc.) described in Kautschuk ⁇ Gummi ⁇ Kunststoff 52 (12) 799 (1999).
  • the modified SBR (A1-1) has a branch and a branching degree of 5 or more. Further, the modified SBR (A1-1) has one or more coupling residues and a styrene-butadiene rubber chain bonded to the coupling residues, and further, the branch is 1 It is more preferable to include a branch in which 5 or more styrene-butadiene rubber chains are bonded to the ring residue.
  • the contraction factor (g ') can be more surely made less than 0.64.
  • the number of styrene-butadiene rubber chains bonded to one coupling residue can be confirmed from the value of contraction factor (g ').
  • the modified SBR (A1-1) has a branch and a branching degree of 6 or more. Further, the modified SBR (A1-1) has one or more coupling residues and a styrene-butadiene rubber chain bonded to the coupling residues, and further, the branch is 1 It is more preferable to include a branch in which 6 or more styrene-butadiene rubber chains are bonded to the ring residue.
  • the contraction factor (g ') can be 0.63 or less.
  • the modified SBR (A1-1) has a branch, and it is more preferable that the degree of branching be 7 or more, and even more preferable that the degree of branching be 8 or more.
  • the upper limit of the branching degree is not particularly limited, but is preferably 18 or less.
  • the modified SBR (A1-1) has one or more coupling residues and an SBR chain that binds to the coupling residue, and further, the branch has a coupling residue of 1. It is even more preferable to include a branch in which 7 or more SBR chains are bound to a group, and more preferably include a branch in which 8 or more SBR chains are bound to one coupling residue. Are particularly preferable.
  • the contraction factor (G ') can be 0.59 or less.
  • the modified SBR (A1-1) as the modified styrene-butadiene rubber (A1) has one or more coupling residues and a styrene-butadiene rubber chain bonded to the coupling residues,
  • the branch preferably includes a branch in which 5 or more of the styrene-butadiene rubber chains are bonded to one coupling residue.
  • the modified SBR (A1-1) as the modified styrene-butadiene rubber (A1) has the following general formula (I):
  • D represents a styrene-butadiene rubber chain
  • R 1 , R 2 and R 3 each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms
  • R 4 and R 3 7 independently represents an alkyl group having 1 to 20 carbon atoms
  • R 5 , R 8 and R 9 each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms
  • R 6 and R 10 independently represents an alkylene group having 1 to 20 carbon atoms
  • R 11 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms
  • m and x each independently represent 1 to 3 Represents an integer, x ⁇ m
  • p represents 1 or 2
  • y represents an integer of 1 to 3
  • z represents an integer of 1 or 2 D
  • ((X ⁇ i) + (y ⁇ j) + (z ⁇ k)) is an integer of 5 to 30, and A is a hydrocarbon group having 1 to 20 carbon atoms, or an oxygen atom or a nitrogen atom. Represents an organic group having at least one atom selected from the group consisting of a silicon atom, a sulfur atom and a phosphorus atom and having no active hydrogen]. As a result, the low rolling resistance and steering stability of the tire can be further improved.
  • the weight average molecular weight of the SBR chain represented by D in the general formula (I) is 10 ⁇ 10 4 to 100 ⁇ 10 4 .
  • the SBR chain is a structural unit of modified SBR, and is, for example, a structural unit derived from SBR produced by reacting SBR with a coupling agent.
  • the hydrocarbon group represented by A includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups.
  • the organic group having no active hydrogen include active hydrogen such as a hydroxyl group (—OH), a secondary amino group (> NH), a primary amino group (—NH 2 ), and a sulfhydryl group (—SH). And an organic group having no functional group.
  • A is the following general formulas (II) to (V):
  • B 1 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and when there are a plurality of B 1's, they are each independently ing
  • B 2 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms
  • B 3 represents an alkyl group having 1 to 20 carbon atoms
  • a represents an integer of 1 to 10
  • B 2 and B 3 when each is present in a plurality, are each independent
  • B 4 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10, and when a plurality of B 4 are present, B 4 is each independently There
  • B 5 represents a single bond or a hydrocarbon group having 1 to 20 carbon atoms, a represents an integer of 1 to 10,
  • A is represented by the general formula (II) or (III), and k represents 0.
  • A is represented by the general formula (II) or (III)
  • k represents 0, and in the general formula (II) or (III), Represents an integer of 2 to 10.
  • A is represented by the general formula (II)
  • k represents 0, and in the general formula (II)
  • a is an integer of 2 to 10. Is shown.
  • examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkylene group having 1 to 20 carbon atoms.
  • the modified SBR (A1-1) has a modifying group containing at least one atom selected from nitrogen and silicon in the molecule.
  • the processability of the rubber composition is improved, and when applied to a tire, the wear resistance, low rolling resistance, and steering stability of the tire can be further improved.
  • the modifying group of the modified SBR (A1-1) preferably has both nitrogen and silicon, more preferably nitrogen and alkoxysilane.
  • the modified SBR (A1-1) having a nitrogen atom the modified SBR (A1-1) has a nitrogen atom or a silicon element when the calculated modification rate is 10% or more by the method for measuring a modification rate described later. Determine that
  • the modified SBR (A1-1) has a silicon atom. Measured using an ultraviolet-visible spectrophotometer (Shimadzu Corporation's trade name "UV-1800") in accordance with JIS K 0101 44.3.1 using 0.5 g of modified SBR as a sample, and measuring the molybdenum blue absorbance Quantify by the method. Thereby, when a silicon atom is detected (detection lower limit: 10 ppm by mass), it is determined that the silicon atom is present.
  • UV-1800 ultraviolet-visible spectrophotometer
  • At least one end of the SBR chain is bonded to the silicon atom of the coupling residue.
  • the ends of a plurality of SBR chains may be bonded to one silicon atom.
  • the terminal of the SBR chain and the alkoxy group or hydroxyl group having 1 to 20 carbon atoms are bonded to one silicon atom, and as a result, the one silicon atom is an alkoxysilyl group or silanol group having 1 to 20 carbon atoms. May be configured.
  • the amount of bound conjugated diene in the modified SBR (A1-1) is, for example, 40 to 100% by mass, or 55 to 80% by mass.
  • amount of the bound conjugated diene is within the above range, it becomes possible to more highly achieve both the dry performance and the steering stability of the tire when the rubber composition is applied to the tire.
  • the amount of bound styrene in the modified SBR (A1-1) is preferably 35% by mass or more, more preferably 37% by mass or more, further preferably 39% by mass or more, 40 It is particularly preferable that the content is at least mass%.
  • the amount of bound styrene in the modified SBR is 35% by mass or more, the wet performance of the tire and the long-term durability of the wet performance can be improved when applied to the tire.
  • the amount of bound styrene in the modified SBR is preferably 60% by mass or less, more preferably 55% by mass or less, further preferably 50% by mass or less, and 45% by mass or less. Is particularly preferred. This is because the low rolling resistance is not deteriorated.
  • the amount of bound aromatic vinyl (the amount of bound styrene) can be measured by the ultraviolet absorption of the phenyl group, and the amount of bound conjugated diene can also be obtained from this. Specifically, it is measured according to the following. Using the modified SBR as a sample, 100 mg of the sample is made up to 100 mL with chloroform and dissolved to obtain a measurement sample. The amount of bound styrene (% by mass) with respect to 100% by mass of the sample is measured based on the amount of absorption at an ultraviolet absorption wavelength (around 254 nm) by the phenyl group of styrene (Spectrophotometer “UV-2450” manufactured by Shimadzu Corporation). .
  • UV-2450 ultraviolet absorption wavelength
  • the amount of vinyl bond in the conjugated diene bond unit is, for example, preferably 35 mol% or more, more preferably 37 mol% or more, and 39 mol% or more. It is more preferable that it is 40 mol% or more, and it is particularly preferable.
  • the vinyl bond content in the conjugated diene bond unit is 35 mol% or more, when applied to a tire, it becomes possible to more highly achieve both the dry performance and steering stability of the tire.
  • the vinyl bond content in the conjugated diene bond unit of the modified SBR (A1-1) is preferably 60 mol% or less, more preferably 55 mol% or less, and 50 mol% or less. Is more preferable and 45 mol% or less is particularly preferable. This is because the workability during rubber kneading can be improved.
  • the vinyl bond amount (1,2-bond amount) in the butadiene bond unit can be determined. Specifically, it is as follows. Using the modified SBR (A1-1) as a sample, 50 mg of the sample is dissolved in 10 mL of carbon disulfide to obtain a measurement sample. Using a solution cell, the infrared spectrum was measured in the range of 600 to 1000 cm ⁇ 1 , and the microstructure of the butadiene moiety, ie, 1,2-vinyl bond, was calculated according to the calculation formula of the above Hampton method by the absorbance at a predetermined wave number. The amount (mol%) is determined (Fourier transform infrared spectrophotometer "FT-IR230" manufactured by JASCO Corporation).
  • the modified SBR (A1-1) preferably has a glass transition point (Tg) higher than ⁇ 50 ° C., more preferably ⁇ 45 to ⁇ 15 ° C.
  • Tg glass transition point
  • the DSC curve is recorded while the temperature is raised in a predetermined temperature range, and the peak top (Infection point) of the DSC differential curve is taken as Tg. Specifically, it is as follows.
  • the temperature was raised from ⁇ 100 ° C. to 20 ° C./min under the flow of 50 mL / min of helium. While the DSC curve is recorded, the peak top (Infection point) of the DSC differential curve is defined as Tg.
  • the modified SBR (A1-1) has a Mooney viscosity measured at 100 ° C. of, for example, 20 to 100, or 30 to 80.
  • the method of measuring the Mooney viscosity is as follows. Using the modified SBR (A1-1) as a sample, a Mooney viscometer (trade name “VR1132” manufactured by Ueshima Seisakusho) is used to measure the Mooney viscosity using an L-shaped rotor in accordance with JIS K6300. The measurement temperature is 100 ° C. when modified SBR is used as a sample. First, after preheating the sample at the test temperature for 1 minute, the rotor is rotated at 2 rpm and the torque after 4 minutes is measured to obtain the Mooney viscosity (ML (1 + 4) ).
  • the method for synthesizing the modified SBR (A1-1) is not particularly limited, and for example, a polymerization step of polymerizing at least butadiene using an organic monolithium compound as a polymerization initiator to obtain a styrene-butadiene rubber, Examples thereof include a synthetic method having a reaction step of reacting a pentafunctional or higher-functional reactive compound (hereinafter, also referred to as “coupling agent”) with the active terminal of styrene-butadiene rubber.
  • a pentafunctional or higher-functional reactive compound hereinafter, also referred to as “coupling agent”
  • the polymerization step includes, for example, polymerization by a growth reaction by a living anionic polymerization reaction. As a result, a styrene-butadiene rubber having an active terminal can be obtained, and the modified SBR (A1-1) with a high modification rate can be obtained.
  • the amount of the organic monolithium compound used as the polymerization initiator can be adjusted according to the target molecular weight (A1-1) of the modified SBR. Decreasing the polymerization initiator increases the molecular weight, while increasing the polymerization initiator decreases the molecular weight.
  • the organomonolithium compound is preferably an alkyllithium compound from the viewpoint of industrial availability and easy control of the polymerization reaction. In this case, SBR (A1-1) having an alkyl group at the polymerization initiation terminal is obtained.
  • the alkyl lithium compound include n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, and stilbene lithium. These organic monolithium compounds may be used alone or in combination of two or more.
  • a batch-type or continuous-type polymerization reaction mode can be appropriately selected and used.
  • An inert solvent may be used in the polymerization step.
  • the inert solvent include aliphatic hydrocarbons such as butane, pentane, hexane and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane and methylcyclohexane; aromatics such as benzene, toluene and xylene. Examples include hydrocarbons.
  • the inert solvent may be used alone or in combination of two or more. Before using an inert solvent for the polymerization reaction, it may be treated with an organometallic compound in order to remove impurities such as arenes and acetylenes in the inert solvent.
  • a polar compound may be used in the polymerization step.
  • a polar compound By using a polar compound, styrene can be randomly copolymerized with butadiene.
  • the polar compound can also be used as a vinylating agent for controlling the microstructure of the conjugated diene part.
  • the polar compound include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis (2-oxolanyl) propane; tetra.
  • Tertiary amine compounds such as methylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine and quinuclidine; alkali metal alkoxides such as potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate and sodium amylate.
  • alkali metal alkoxides such as potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate and sodium amylate.
  • phosphine compounds such as triphenylphosphine and the like can be mentioned.
  • the polar compounds may be used alone or in combination of two or more.
  • the polymerization temperature in the polymerization step may be appropriately adjusted, and is, for example, 0 to 120 ° C. or 50 to 100 ° C. from the viewpoint of ensuring a sufficient reaction amount of the coupling agent with respect to the active terminal after completion of the polymerization.
  • the coupling agent includes, for example, a pentafunctional or more reactive compound having a nitrogen atom and a silicon atom.
  • the reactive compound has at least three silicon-containing functional groups.
  • the coupling agent is preferably one in which at least one silicon atom forms an alkoxysilyl group or a silanol group having 1 to 20 carbon atoms, and more preferably a compound represented by the following general formula (VI) It is.
  • One type of coupling agent may be used alone, or two or more types may be used in combination.
  • the alkoxysilyl group of the coupling agent tends to react with the active terminal of SBR to dissociate the alkoxylithium and form a bond between the terminal of the SBR chain and the silicon of the coupling residue.
  • the value obtained by subtracting the SiOR number subtracted by the reaction from the total number of SiOR contained in one molecule of the coupling agent is the number of alkoxysilyl groups contained in the coupling residue.
  • the azasilacycle group of the coupling agent forms a> N-Li bond and a bond between the SBR terminal and silicon of the coupling residue. Note that the> N—Li bond tends to easily become> NH and LiOH due to water or the like at the time of finishing. Further, in the coupling agent, the unreacted remaining alkoxysilyl group can easily become silanol (Si—OH group) by water or the like at the time of finishing.
  • the modified SBR (A1-1) is a styrene-butadiene rubber represented by the following general formula (VI):
  • R 12 , R 13 and R 14 each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms
  • R 15 , R 16 , R 17 , R 18 and R 20 Are each independently an alkyl group having 1 to 20 carbon atoms
  • R 19 and R 22 are each independently an alkylene group having 1 to 20 carbon atoms
  • R 21 is an alkyl group having 1 to 20 carbon atoms
  • m represents an integer of 1 to 3
  • p represents 1 or 2
  • R 12 to R 22 , m and p each independently represent a plurality of them.
  • i, j and k each independently represent an integer of 0 to 6, provided that (i + j + k) is an integer of 3 to 10 and A is a hydrocarbon group having 1 to 20 carbon atoms, or , Oxygen atom, nitrogen atom, silicon atom, sulfur atom and phosphorus atom? And an organic group having at least one atom selected from the group consisting of and having no active hydrogen].
  • the hydrocarbon group represented by A includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups.
  • the organic group having no active hydrogen include active hydrogen such as a hydroxyl group (—OH), a secondary amino group (> NH), a primary amino group (—NH 2 ), and a sulfhydryl group (—SH).
  • active hydrogen such as a hydroxyl group (—OH), a secondary amino group (> NH), a primary amino group (—NH 2 ), and a sulfhydryl group (—SH).
  • A is represented by the general formula (II) or (III), and k represents 0.
  • A is represented by the general formula (II) or (III), k represents 0, and in the general formula (II) or (III), a Represents an integer of 2 to 10.
  • A is represented by the general formula (II), k is 0, and in the general formula (II), a is an integer of 2 to 10. Indicates.
  • Examples of such coupling agents include tetrakis [3- (2,2-dimethoxy-1-aza-2-silacyclopentane) propyl] -1,3-propanediamine and tetrakis (3-trimethoxysilylpropyl).
  • the addition amount of the compound represented by the general formula (VI) as the coupling agent can be adjusted so that the number of moles of SBR and the number of moles of the coupling agent are reacted in a desired stoichiometric ratio, This tends to achieve the desired degree of branching.
  • the number of moles of the polymerization initiator is, for example, 5.0 times or more, or 6.0 times or more the number of moles of the coupling agent.
  • the number of functional groups ((m ⁇ 1) ⁇ i + p ⁇ j + k) of the coupling agent is an integer of 5 to 10, or an integer of 6 to 10.
  • the reaction temperature in the reaction step may be appropriately adjusted, and is, for example, 0 to 120 ° C or 50 to 100 ° C. Further, the temperature change from after the polymerization step until the coupling agent is added is, for example, 10 ° C. or less, or 5 ° C. or less.
  • the reaction time in the reaction step may be appropriately adjusted, and is, for example, 10 seconds or more, or 30 seconds or more.
  • the time from the end of the polymerization step to the start of the reaction step is preferably shorter from the viewpoint of the coupling ratio, for example, within 5 minutes.
  • ⁇ Mixing in the reaction step may be any of mechanical stirring, stirring with a static mixer, and the like.
  • the molecular weight distribution (Mw / Mn) of SBR is set to 1.5 to 2.5, or 1.8 to 2.2. Good. Further, in the obtained modified SBR (A1-1), it is preferable that a peak with a single peak is detected in the molecular weight curve by GPC. In one example, when the peak molecular weight of the modified SBR (A1-1) by GPC is Mp 1 and the peak molecular weight of the SBR is Mp 2 , the following formula is established.
  • Mp 1 / Mp 2 ⁇ 1.8 ⁇ 10 ⁇ 12 ⁇ (Mp 2 ⁇ 120 ⁇ 10 4 ) 2 +2
  • Mp 2 is between 20 ⁇ 10 4 and 80 ⁇ 10 4
  • Mp 1 is between 30 ⁇ 10 4 and 150 ⁇ 10 4 .
  • the modification rate of the modified SBR (A1-1) is, for example, 30% by mass or more, 50% by mass or more, or 70% by mass or more.
  • the modification rate is 30% by mass or more, when it is applied to a tire, it is possible to further improve the low rolling resistance while improving the wear resistance of the tire.
  • the method for measuring the denaturation rate is as follows.
  • the modified SBR (A1-1) sample is measured by applying the property that the modified basic polymer component is adsorbed to a GPC column containing silica gel as a packing material.
  • the amount of adsorption of the sample and the sample solution containing the low-molecular-weight internal standard polystyrene on the silica-based column was determined from the difference between the chromatogram measured on the polystyrene-based column and the chromatogram measured on the silica-based column, and the denaturation rate was determined.
  • sample solution is prepared by dissolving 10 mg of a sample and 5 mg of standard polystyrene in 20 mL of THF.
  • GPC measurement conditions using a polystyrene column 10 ⁇ L of a sample solution was injected into the apparatus using 5 mL / L of THF containing triethylamine as an eluent using a trade name “HLC-8320GPC” manufactured by Tosoh Corporation, and a column oven was used.
  • a chromatogram is obtained using an RI detector at a temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.
  • TSKgel SuperMultipore HZ-H (trade name, manufactured by Tosoh Corporation) are connected, and a guard column is connected to a column (trade name, TSKguardcolumn SuperMP (HZ) -H, manufactured by Tosoh Corporation) connected as a guard column.
  • GPC measurement conditions using a silica-based column Tosoh's product name "HLC-8320GPC” was used, THF was used as an eluent, and 50 ⁇ L of the sample solution was injected into the apparatus, the column oven temperature was 40 ° C, and the THF flow rate was A chromatogram is obtained using an RI detector at 0.5 ml / min.
  • the column is used by connecting the trade names “Zorbax PSM-1000S”, “PSM-300S”, and “PSM-60S”, and the trade name “DIOL 4.6 ⁇ 12.5 mm 5micron” as a guard column at the front stage. Connect and use.
  • a deactivating agent, a neutralizing agent, etc. may be added to the copolymer solution, if necessary.
  • the quencher include water; alcohols such as methanol, ethanol, and isopropanol.
  • the neutralizing agent include carboxylic acids such as stearic acid, oleic acid, versatic acid (mixed carboxylic acid mixture having 9 to 11 carbon atoms and 10 as the center); aqueous solutions of inorganic acids and carbonic acid. Gas etc. are mentioned.
  • the modified SBR (A1-1) is, for example, 2,6-di-tert-butyl-4-hydroxytoluene (BHT) from the viewpoint of preventing gel formation after polymerization and improving stability during processing. ), N-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-tert-butylphenol) propinate, 2-methyl-4,6-bis [(octylthio) methyl] phenol, etc. It is preferable to add.
  • BHT 2,6-di-tert-butyl-4-hydroxytoluene
  • Extending oil may be added, if necessary, in order to further improve the processability of the modified SBR (A1-1).
  • Examples of the method of adding the extending oil to the modified SBR (A1-1) include a method of adding the extending oil to the polymer solution, mixing them, and desolvating the oil-extended copolymer solution. .
  • the modified SBR (A1-1) from the polymer solution As a method for obtaining the modified SBR (A1-1) from the polymer solution, a known method can be used. As the method, for example, after separating the solvent by steam stripping or the like, the polymer is separated by filtration, further dehydrated and dried to obtain a polymer, concentrated in a flushing tank, further vented extruder, etc. And a method of devolatilizing directly with a drum dryer or the like.
  • modified styrene-butadiene rubber (A1) a modified styrene-butadiene rubber other than the modified SBR (A1-1) described above can be used.
  • modified (co) polymer as the polymer component P2 in WO 2017/0777712 and the modified polymer E described in the examples (these rubbers are hereinafter referred to as "modified SBR (A1-2)").
  • modified SBR (A1-2) modified SBR (A1-2)
  • modified styrene-butadiene rubber (A1) a modified styrene-butadiene rubber having a bound styrene content of 15% by mass or less (hereinafter, referred to as "modified styrene-butadiene rubber (A1-3)" or “modified SBR (A1-3)”.
  • modified styrene-butadiene rubber (A1-3) a modified styrene-butadiene rubber having a bound styrene content of 15% by mass or less
  • modified SBR (A1-3) modified SBR (A1-3)
  • the modified SBR (A1-3) can be composed of, for example, one kind or two or more kinds of modified styrene butadiene rubber.
  • the type of the modified SBR (A1-3) is not particularly limited as long as the amount of bound styrene is 15% by mass or less, but solution-polymerized SBR is preferable. This is because the wet performance of the tire, the steering stability, and the low rolling resistance can be well balanced at the same time.
  • modified (co) polymers as the polymer component P2 in WO 2017/0777712 and modified polymers C and modified polymers described in Examples D etc. are mentioned.
  • the content of the modified SBR (A1-3) in the rubber component is not particularly limited, but from the viewpoint of achieving a good balance of tire wet performance, steering stability, and low rolling resistance,
  • the amount is preferably 20 to 50% by mass, more preferably 30 to 40% by mass.
  • the rubber component further contains natural rubber in addition to the modified styrene-butadiene rubber (A1) described above.
  • natural rubber By containing a natural rubber in the rubber component, a large amount of a polyolefin-based softening agent described below can be incorporated into the natural rubber, and as a result, the polyolefin-based softening agent can be unevenly distributed in the rubber composition. It is possible to further improve wet performance and long-lasting wet performance when applied to. In addition, since natural rubber is used, it is possible to improve the wear resistance and crack growth resistance of the tire.
  • the content of the natural rubber in the rubber component is not particularly limited, but is preferably 10% by mass or more from the viewpoint of further improving the wet performance of the tire and the long-term durability of the wet performance, 20 It is more preferably at least 30% by mass, further preferably at least 30% by mass. From the viewpoint of maintaining the wet performance of the tire at a high level, the content of the natural rubber in the rubber component is preferably 70% by mass or less, and more preferably 60% by mass or less. preferable.
  • the rubber composition of the present invention contains a filler in addition to the rubber component described above.
  • the filler contains 40 parts by mass or more and less than 70 parts by mass of silica with respect to 100 parts by mass of the rubber component.
  • the content of the silica needs to be 40 parts by mass or more and less than 70 parts by mass, preferably 45 to 75 parts by mass, and 50 to 70 parts by mass with respect to 100 parts by mass of the rubber component. Is more preferable.
  • the content of the silica is 40 parts by mass or more with respect to 100 parts by mass of the rubber component, the wet performance and the steering stability can be sufficiently improved, and the rubber content is less than 70 parts by mass. It is possible to prevent deterioration of processability and low rolling resistance of the composition.
  • examples of the type of silica include wet silica (hydrous silicic acid), dry silica (anhydrous silicic acid), calcium silicate, and aluminum silicate.
  • wet silica is preferable.
  • These silicas may be used alone or in combination of two or more.
  • precipitated silica can be used as the wet silica.
  • Precipitated silica means that at the initial stage of production, the reaction solution proceeds at a relatively high temperature in a neutral to alkaline pH range to grow silica primary particles, and then the primary particles are aggregated by controlling to acidic side. It is the silica obtained as a result.
  • the silica (B1) has a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) of 140 to 260 m 2 / g, preferably 160 to 240 m 2 / g, and 180 to 220 m 2 / g. More preferably. If the CTAB of the silica (B1) is 140 m 2 / g or more, the wear resistance of the tire can be improved, and if the CTAB of the silica (B1) is 260 m 2 / g or less, the rolling resistance and the rubber composition It is possible to suppress deterioration of workability.
  • CTAB cetyltrimethylammonium bromide adsorption specific surface area
  • the silica (B2) has a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) of 90 to 120 m 2 / g, and preferably 90 to 110 m 2 / g.
  • CTAB cetyltrimethylammonium bromide adsorption specific surface area
  • the silica has a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) (m 2 / g) and an ink bottle-like pore index (IB) expressed by the following formula (1): IB ⁇ ⁇ 0.36 ⁇ CTAB + 86.8 (1)
  • CTAB cetyltrimethylammonium bromide adsorption specific surface area
  • IB ink bottle-like pore index
  • IB M2-M1
  • CAB cetyltrimethylammonium bromide adsorption specific surface area
  • IB ink bottle-like pore index
  • the filler may further contain carbon black.
  • carbon black is not particularly limited, and examples thereof include GPF, FEF, HAF, ISAF, and SAF grade carbon black.
  • GPF GPF
  • FEF FEF
  • HAF HAF
  • ISAF SAF grade carbon black
  • SAF SAF grade carbon blacks are preferable from the viewpoint of improving the wear resistance of the rubber composition.
  • These carbon blacks may be used alone or in combination of two or more.
  • the content of the carbon black is not particularly limited, but is preferably in the range of 1 to 30 parts by mass and more preferably in the range of 3 to 20 parts by mass with respect to 100 parts by mass of the rubber component.
  • the content of the carbon black is not particularly limited, but is preferably in the range of 1 to 30 parts by mass and more preferably in the range of 3 to 20 parts by mass with respect to 100 parts by mass of the rubber component.
  • the filler may be the following general formula (XX): nM ⁇ xSiO y ⁇ zH 2 O (XX) [Wherein M is a metal selected from the group consisting of aluminum, magnesium, titanium, calcium and zirconium, oxides or hydroxides of these metals, and hydrates thereof, or carbonates of these metals. At least one selected; n, x, y, and z are each an integer of 1 to 5, an integer of 0 to 10, an integer of 2 to 5, and an integer of 0 to 10] Can also be included.
  • Aluminum hydroxide [Al (OH) 3 ] such as gibbsite and bayerite, aluminum carbonate [Al 2 (CO 3 ) 3 ], magnesium hydroxide [Mg (OH) 2 ], magnesium oxide (MgO), magnesium carbonate (MgCO 3), talc (3MgO ⁇ 4SiO 2 ⁇ H 2 O), attapulgite (5MgO ⁇ 8SiO 2 ⁇ 9H 2 O), titanium white (TiO 2), titanium black (TiO 2n-1), calcium oxide (CaO), water calcium oxide [Ca (OH) 2], magnesium aluminum oxide (MgO ⁇ Al 2 O 3) , clay (Al 2 O 3 ⁇ 2 iO 2), kaolin (Al
  • the rubber composition of the present invention contains a polyolefin softener having a weight average molecular weight (Mw) of 5,000 to 50,000 in addition to the rubber component and the filler described above.
  • Mw weight average molecular weight
  • the agent can stay in the rubber for a long time, and can impart a softening action longer than that of a conventional softening agent, so that the wet performance can be maintained for a long time.
  • the weight average molecular weight (Mw) of the polyolefin-based softening agent is set in the range of 5,000 to 50,000 in order to reduce the unvulcanized viscosity of the rubber composition by setting the number average molecular weight to 50,000 or less.
  • Mw weight average molecular weight
  • the weight average molecular weight (Mw) of the polyolefin softener is preferably 5,000 to 50,000, more preferably 5,000 to 30,000, further preferably 5,000 to 28,000, and more preferably 5,500 to It is more preferably 25,000, even more preferably 5500 to 18000, particularly preferably 5700 to 13000, particularly preferably 6000 to 12000, and most preferably 7000 to 11000.
  • the weight average molecular weight (Mw) described above can be determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.
  • the number of carbon atoms contained in the repeating unit of the polyolefin-based softening agent is preferably 3 or more, and more preferably 4 or more. Further, the number of carbon atoms contained in the repeating unit is preferably 15 or less, more preferably 12 or less, further preferably 8 or less, further preferably 6 or less, and 5 or less. Is particularly preferable. When the number of carbon atoms is within the above range, increase in elastic modulus of the rubber composition at low temperature can be suppressed, and fracture characteristics at low temperature can be maintained at a high level. Further, the repeating unit may have a branched structure and may have a structure such as graft copolymerization. Furthermore, the polyolefin-based softening agent may have a functional group at the terminal.
  • the type of the polyolefin-based softening agent is not particularly limited.
  • the polyolefin-based softening agent contains polybutene or polyisobutylene.
  • the polyolefin-based softening agent contains at least polybutene, and the polybutene is preferably unmodified polybutene.
  • the unmodified polybutene is a synthetic resin obtained by polymerizing 1-butene. Further, it is more preferable that the unmodified polybutene is not hydrogenated.
  • the ratio of these in the polyolefin-based softening agent is preferably about 30 to 80% by mass in total. This is because the compatibility with the rubber component and the softening action in the low temperature region can be further enhanced.
  • the content of the polyolefin-based softening agent needs to be 3 parts by mass or more based on 100 parts by mass of the rubber component, and 5 parts by mass or more based on 100 parts by mass of the rubber component. It is more preferably 10 parts by mass or more.
  • the content of the polyolefin-based softening agent needs to be 35 parts by mass or less with respect to 100 parts by mass of the rubber component, and is preferably 30 parts by mass or less with respect to 100 parts by mass of the rubber component. More preferably 25 parts by mass or less.
  • the rubber composition of the present invention preferably further contains a thermoplastic resin in addition to the rubber component, the filler and the polyolefin softener described above. Since the rubber composition contains the thermoplastic resin, the wet performance of the tire can be further enhanced.
  • the thermoplastic resin used in the present invention does not include the above-mentioned polyolefin softening agent.
  • the content of the thermoplastic resin is preferably 1 to 70 parts by mass, more preferably 5 to 50 parts by mass, and further preferably 10 to 40 parts by mass with respect to 100 parts by mass of the rubber component.
  • the content of the thermoplastic resin is 1 part by mass or more with respect to 100 parts by mass of the rubber component, the wet performance can be further improved, and the content of the thermoplastic resin is 70 parts by mass with respect to 100 parts by mass of the rubber component.
  • it is below deterioration of steering stability due to a decrease in elastic modulus of the rubber composition can be suppressed.
  • thermoplastic resin examples include C 5 resin, C 5 -C 9 resin, C 9 resin, dicyclopentadiene resin, terpene phenol resin, terpene resin, rosin resin, and alkylphenol resin, and C 5 resin. At least one selected from the group consisting of resin, C 5 -C 9 resin, C 9 resin, dicyclopentadiene resin, rosin resin, and alkylphenol resin is preferable. When at least one of C 5 resin, C 5 -C 9 resin, C 9 resin, dicyclopentadiene resin, terpene phenol resin, terpene resin, rosin resin, and alkylphenol resin is contained as the thermoplastic resin, Wet performance can be further improved.
  • thermoplastic resins C 5 resins, C 5 -C 9 resins and C 9 resins are particularly preferred.
  • C 5 -C 9 series resins and C 9 series resins have high compatibility with natural rubber and have the effect of increasing the elastic modulus of the rubber composition in the low strain region, and the elasticity of the rubber composition in the high strain region. The effect of lowering the rate is further increased, and the wet performance of the tire can be further improved.
  • the thermoplastic resins may be used alone or in combination of two or more.
  • the C 5 type resin refers to a C 5 type synthetic petroleum resin, and examples of the C 5 type resin include C 5 fraction obtained by thermal decomposition of naphtha of petrochemical industry, AlCl 3 , BF 3, etc. And an aliphatic petroleum resin obtained by polymerization using the Friedel-Crafts type catalyst.
  • the C 5 fraction usually contains olefinic hydrocarbons such as 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene and 3-methyl-1-butene, 2- Diolefin hydrocarbons such as methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, and 3-methyl-1,2-butadiene are included.
  • a commercially available product can be used as the C 5 resin, for example, "ESCOLETS (registered trademark) 1000 series", which is an aliphatic petroleum resin manufactured by ExxonMobil Chemical Co., Ltd., an aliphatic manufactured by ZEON CORPORATION.
  • ESCOLETS (registered trademark) 1000 series which is an aliphatic petroleum resin manufactured by ExxonMobil Chemical Co., Ltd., an aliphatic manufactured by ZEON CORPORATION.
  • “Quinton (registered trademark) 100 series” which is a petroleum resin
  • the C 5 -C 9 series resin means a C 5 -C 9 series synthetic petroleum resin, and examples of the C 5 -C 9 series resin include a C 5 fraction and a C 9 fraction derived from petroleum. , AlCl 3 , BF 3 and other solid polymers obtained by polymerization using a Friedel-Crafts type catalyst. More specifically, styrene, vinyltoluene, ⁇ -methylstyrene, indene And the like. As the C 5 -C 9 resin, a resin having a small amount of C 9 or more components is preferable from the viewpoint of compatibility with the rubber component.
  • C 9 or more components in the total resin is less than 50 wt%, preferably shall refer to or less than 40 wt%.
  • the C 5 -C 9 resin a commercially available product can be used. Manufactured by Tonen Kagaku Co., Ltd. and the like.
  • the C 9 resin is, for example, vinyltoluene, alkylstyrene, and indene as main monomers, which are C 9 fractions that are by-produced together with petrochemical basic raw materials such as ethylene and propylene by thermal decomposition of naphtha in the petrochemical industry. It is a resin obtained by polymerizing an aromatic having 9 carbon atoms.
  • specific examples of the C 9 fraction obtained by thermal decomposition of naphtha include vinyltoluene, ⁇ -methylstyrene, ⁇ -methylstyrene, ⁇ -methylstyrene, o-methylstyrene, p-methylstyrene, indene and the like. Is mentioned.
  • the C 9 -based resin includes C 9 fraction, C 8 fraction such as styrene, C 10 fraction such as methylindene and 1,3-dimethylstyrene, and further naphthalene, vinylnaphthalene, vinylanthracene, p It can also be obtained by using -tert-butylstyrene or the like as a raw material and copolymerizing the C 8 to C 10 fraction or the like as a mixture as it is, for example, with a Friedel-Crafts type catalyst. Further, the C 9 resin may be a modified petroleum resin modified with a compound having a hydroxyl group, an unsaturated carboxylic acid compound or the like.
  • C 9 resin commercially available products can be used.
  • trade names “Nisseki Neopolymer (registered trademark) L-90” and “Nisseki Examples include Neopolymer (registered trademark) 120, Nisseki Neopolymer (registered trademark) 130, Nisseki Neopolymer (registered trademark) 140 (manufactured by JX Nikko Nisseki Energy Co., Ltd.) and the like.
  • the above-mentioned dicyclopentadiene resin is a petroleum resin produced by using dicyclopentadiene obtained by dimerizing cyclopentadiene as a main raw material.
  • dicyclopentadiene resin commercially available products can be used. For example, “1105, 1325,” in the product name “Quinton (registered trademark) 1000 series”, which is an alicyclic petroleum resin manufactured by Nippon Zeon Co., Ltd. 1340 ”and the like.
  • the terpene phenol resin can be obtained, for example, by reacting a terpene with various phenols using a Friedel-Crafts type catalyst, or by further condensing with formalin.
  • a terpene used as a raw material, and monoterpene hydrocarbons such as ⁇ -pinene and limonene are preferable, those containing ⁇ -pinene are more preferable, and ⁇ -pinene is particularly preferable.
  • terpene phenolic resin commercially available products can be used, for example, trade names "Tamanor 803L”, “Tamanor 901” (manufactured by Arakawa Chemical Industry Co., Ltd.), trade names "YS Polystar (registered trademark) U” series.
  • the terpene resin is a solid resin obtained by blending turpentine oil obtained at the same time when rosin is obtained from a pine tree, or a polymerization component separated therefrom, and polymerizing using a Friedel-Crafts type catalyst. Examples thereof include ⁇ -pinene resin and ⁇ -pinene resin.
  • terpene resin commercially available products can be used. For example, the product name “YS resin” series (PX-1250, TR-105, etc.) manufactured by Yasuhara Chemical Co., Ltd., the product name “Picolite” manufactured by Hercules Co. Examples include series (A115, S115, etc.).
  • the rosin resin is a residue remaining after distilling turpentine essential oil by collecting balsams such as pine resin (pine tar) that is sap of a Pinaceae plant.
  • They are a natural resin as a main component, a modified resin obtained by modifying them and processing them by hydrogenation, and a hydrogenated resin. Examples thereof include natural resin rosin, its polymerized rosin and partially hydrogenated rosin; glycerin ester rosin, its partially hydrogenated rosin, fully hydrogenated rosin and polymerized rosin; pentaerythritol ester rosin, its partially hydrogenated rosin and polymerized rosin. .
  • Examples of natural resin rosin include gum rosin contained in raw pine resin, tall oil, tall oil rosin, and wood rosin.
  • As the rosin resin a commercially available product can be used. For example, a product name “Neotol 105” (manufactured by Harima Kasei Co., Ltd.), a product name “SN Tuck 754” (manufactured by San Nopco Co., Ltd.), and a product name “Lime Resin” No.
  • the alkylphenol resin is obtained, for example, by a condensation reaction of an alkylphenol and formaldehyde under a catalyst.
  • alkylphenol resin commercially available products can be used, for example, trade name "Hitanol 1502P” (alkylphenol formaldehyde resin, manufactured by Hitachi Chemical Co., Ltd.), trade name "Takkyrol 201” (alkylphenol formaldehyde resin, Taoka Chemical Industry Co., Ltd.
  • the rubber composition of the present invention can also contain, as a softening agent, a low-temperature softening agent other than the above-mentioned polyolefin-based softening agent.
  • a softening agent such as a low-temperature softening agent, the rubber can be softened in a low temperature range (around 0 ° C.), and thus excellent wet performance can be realized. It also has the effect of improving the workability and workability of the rubber composition containing the low-temperature softening agent.
  • the low-temperature softening agent is a softening agent that does not include the above-mentioned polyolefin-based softening agent, for example, mineral oil derived from minerals, aromatic oil derived from petroleum, paraffin oil, naphthene oil, palm oil derived from natural products.
  • octyl oleate is preferable, and among these, octyl oleate is preferable from the viewpoint of excellent softening performance in a low temperature range and further improving grip performance on a snowy and snowy road surface and a wet road surface of the tire.
  • the content of the low-temperature softening agent is not particularly limited, but is preferably in the range of 1 to 5 parts by mass, more preferably 1.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component.
  • the total content of the softening agent contained in the rubber composition of the present invention is preferably 10 to 35 parts by mass, and more preferably 15 to 35 parts by mass with respect to 100 parts by mass of the rubber component. More preferable.
  • the total content of the softening agent is the total content of various softening agents (components having a softening effect) contained in the rubber composition.
  • the polyolefin-based softener, the thermoplastic resin, the low-temperature softener other than the polyolefin-based softener, oil, and the like correspond to the softener.
  • the rubber composition of the present invention may contain a silane coupling agent in order to improve the compounding effect of the silica.
  • the silane coupling agent is represented by the following formula (VII): A m B 3-m Si- ( CH 2) a -S b - (CH 2) a -SiA m B 3-m ⁇ (VII) [In the formula (VII), A is C n H 2n + 1 O (n is an integer of 1 to 3) or a chlorine atom, B is an alkyl group having 1 to 3 carbon atoms, m is an integer of 1 to 3, a is an integer of 1 to 9 and b is an integer of 1 or more.
  • A is C n H 2n + 1 O (n is an integer of 1 to 3) or a chlorine atom
  • B is an alkyl group having 1 to 3 carbon atoms
  • Y is a mercapto group, a vinyl group
  • It is an amino group, a glycidoxy group or an epoxy group
  • m is an integer of 1 to 3
  • c is an integer of 0 to 9.
  • A is C n H 2n + 1 O (n is an integer of 1 to 3) or a chlorine atom
  • B is an alkyl group having 1 to 3 carbon atoms
  • Z is a benzothiazolyl group
  • N N A dimethylthiocarbamoyl group or a methacryloyl group
  • m may be an integer of 1 to 3
  • a may be an integer of 1 to 9
  • b may be an integer of 1 or more and may have a distribution.
  • R 32 is selected from hydrogen or an alkyl group having 1 to 18 carbon atoms, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group;
  • R 33 is — [O (R 38 O) m ] 0.5 — (wherein R 38 is selected from an alkylene group and a cycloalkylene group, and has 1 to 18 carbon atoms, and m is 1 to 4).
  • R 34 is selected from an alkylene group, a cycloalkylene group, a cycloalkylalkylene group, an alkenylene group, an arylene group and an aralkylene group, and has 1 to 18 carbon atoms
  • R 35 is selected from an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group and an aralkyl group, and has 1 to 18 carbon atoms.
  • the compound represented by this is preferable.
  • These silane coupling agents may be used alone or in combination of two or more.
  • Examples of the compound represented by the above formula (VII) include bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (3-methyldimethoxysilylpropyl) tetrasulfide, and bis. Examples thereof include (3-triethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (3-triethoxysilylpropyl) trisulfide and the like.
  • the alkyl group may be linear or branched, and the alkyl group Examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group and the like.
  • the alkenyl group may be linear or branched, and examples of the alkenyl group include a vinyl group, an allyl group and a methanyl group.
  • examples of the cycloalkyl group include a cyclohexyl group and an ethylcyclohexyl group
  • examples of the cycloalkenyl group include a cyclohexenyl group and an ethylcyclohexenyl group
  • examples of the aryl group include a phenyl group and a tolyl group.
  • examples of the aralkyl group include a phenethyl group.
  • the alkylene group may be linear or branched, and examples of the alkylene group include a methylene group, an ethylene group, a trimethylene group, and a propylene group. Further, examples of the cycloalkylene group include a cyclohexylene group and the like. Furthermore, in R 34 , the alkenylene group may be linear or branched, and examples of the alkenylene group include a vinylene group and a propenylene group.
  • the cycloalkylalkylene group includes a cyclohexylmethylene group, the arylene group includes a phenylene group, and the aralkylene group includes a xylylene group.
  • a — [O (R 38 O) m ] 0.5 — group is a 1,2-ethanedioxy group, a 1,3-propanedioxy group, or a 1,4-butanedioxy group.
  • the compound represented by the above formula (X) can be synthesized in the same manner as in the method described in JP-A No. 2001-505225, and the product name “NXT” manufactured by Momentive Performance Materials Inc.
  • the amount of the silane coupling agent is preferably 1 part by mass or more, more preferably 4 parts by mass or more, and 20 parts by mass or less with respect to 100 parts by mass of the silica. Is preferable, and 12 parts by mass or less is more preferable.
  • the rubber composition of the present invention in addition to the rubber component, the filler and the polyolefin-based softening agent described above, as an optional component, a thermoplastic resin, a low temperature softening agent, a silane coupling agent, the rubber industry
  • a thermoplastic resin e.g., polyethylene glycol dimethacrylate
  • a low temperature softening agent e.g., polyethylene glycol dimethacrylate
  • silane coupling agent e.g., silane coupling agent
  • the compounding agents usually used in, for example, an antioxidant, a vulcanization accelerator, a vulcanization accelerator auxiliary, a vulcanizing agent and the like can be appropriately selected and contained within a range not impairing the object of the present invention.
  • antiaging agent known ones can be used and are not particularly limited.
  • a phenol anti-aging agent an imidazole anti-aging agent, an amine anti-aging agent, etc. can be mentioned.
  • These antioxidants can be used alone or in combination of two or more.
  • vulcanization accelerator a known one can be used and is not particularly limited.
  • thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide; N-cyclohexyl-2-benzothiazylsulfenamide, Nt-butyl-2-benzothiazylsulfenamide, etc.
  • Sulfenamide-based vulcanization accelerators Sulfenamide-based vulcanization accelerators; guanidine-based vulcanization accelerators such as diphenylguanidine (1,3-diphenylguanidine); tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetradodecylthiuram disulfide, tetraoctyl Thiuram vulcanization accelerators such as thiuram disulfide, tetrabenzyl thiuram disulfide and dipentamethylene thiuram tetrasulfide; Dithiocarbamate vulcanization accelerators such as zinc dimethyldithiocarbamate; Kirujichiorin zinc, and the like.
  • guanidine-based vulcanization accelerators such as diphenylguanidine (1,3-diphenylguan
  • the vulcanization acceleration aid examples include zinc white (ZnO) and fatty acids.
  • the fatty acid may be saturated or unsaturated, linear or branched fatty acid, and the carbon number of the fatty acid is not particularly limited, but for example, a fatty acid having 1 to 30 carbon atoms, preferably 15 to 30 carbon atoms, More specifically, cyclohexanoic acid (cyclohexanecarboxylic acid), naphthenic acid such as alkylcyclopentane having a side chain; hexanoic acid, octanoic acid, decanoic acid (including branched carboxylic acid such as neodecanoic acid), dodecanoic acid, tetradecane Examples thereof include acids, saturated fatty acids such as hexadecanoic acid and octadecanoic acid (stearic acid); unsaturated fatty acids such as methacrylic acid, oleic acid, linoleic acid and
  • the tread of the present invention is a tread of a tire, and is characterized by using the above-described rubber composition of the present invention. With the above-described structure, the wet performance can be maintained for a long period of time while being excellent in wet performance, low rolling resistance and steering stability.
  • ⁇ Rubber composition for base tread The rubber composition for the base tread of the present invention, Rubber component, 5 parts by mass or more and 80 parts by mass or less of a filler with respect to 100 parts by mass of the rubber component, A polyolefin softener having a weight average molecular weight (Mw) of 5,000 to 50,000 and 3 to 35 parts by weight based on 100 parts by weight of the rubber component; It is characterized by including.
  • Mw weight average molecular weight
  • the rubber composition for a base tread of the present invention by using the rubber component and an appropriate amount of a filler, when the rubber composition for a base tread is applied to a tire, low rolling resistance and durability are at a high level. Can be compatible. However, there was still room for improvement regarding wet performance and performance for maintaining wet performance for a long period of time. Therefore, in the present invention, by including a polyolefin-based softening agent having a weight average molecular weight (Mw) of 5,000 to 50,000 in the rubber composition, the rubber composition stays in the rubber for a long time even after a lapse of time and imparts a softening effect. Therefore, it is possible to improve the wet performance and maintain the wet performance for a long period of time (hereinafter, may be referred to as “long-lasting wet performance”) as compared with the related art.
  • Mw weight average molecular weight
  • the rubber component is not particularly limited, but it is preferable to contain a natural rubber (NR) or a synthetic diene rubber from the viewpoint of enhancing low rolling resistance and durability.
  • NR natural rubber
  • synthetic diene rubber for example, butadiene rubber (BR), styrene butadiene rubber (SBR), isoprene rubber (IR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), etc. Is mentioned.
  • non-diene rubbers such as ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM) and butyl rubber (IIR) may be contained depending on the required performance.
  • the type and content of the filler contained in the rubber composition for a base tread of the present invention is not particularly limited and can be appropriately changed according to the required performance.
  • the type of carbon black is not particularly limited and can be appropriately selected according to the required performance.
  • the carbon black for example, FEF, SRF, HAF, ISAF and SAF grades can be used.
  • the carbon black has a nitrogen adsorption specific surface area (N 2 SA) of 20 to 350 m 2 / g. Is more preferable, 20 to 100 m 2 / g is more preferable, 23 to 78 m 2 / g is even more preferable, and 27 to 63 m 2 / g is particularly preferable.
  • the nitrogen adsorption specific surface area is measured according to ASTM D3037-88.
  • the content of the carbon black contained in the rubber composition for a base tread of the present invention is preferably 5 to 80 parts by mass, and preferably 5 to 70 parts by mass with respect to 100 parts by mass of the rubber component. It is more preferable that the amount is 5 to 60 parts by mass.
  • the content of the filler contained in the rubber composition for a base tread of the present invention from the viewpoint of achieving a high level of both low heat buildup and durability when applied to a tire, the rubber component 100 is used.
  • the amount is preferably 5 to 80 parts by mass, more preferably 8 to 70 parts by mass, further preferably 12 to 62 parts by mass, and 16 to 57 parts by mass with respect to parts by mass. Particularly preferred.
  • the content of the filler is 5 parts by mass or more with respect to 100 parts by mass of the rubber component, higher durability can be obtained, and when it is 80 parts by mass or less, low heat buildup is achieved. Deterioration can be suppressed.
  • the polyolefin softener contained in the rubber composition for a base tread of the present invention has a weight average molecular weight (Mw) of 5,000 to 50,000 as described in the rubber composition of the present invention.
  • Mw weight average molecular weight
  • the content of the polyolefin-based softening agent needs to be 3 parts by mass or more with respect to 100 parts by mass of the rubber component, and may be 4 parts by mass or more with respect to 100 parts by mass of the rubber component. It is more preferably 5 parts by mass or more.
  • the content of the polyolefin-based softening agent needs to be 35 parts by mass or less with respect to 100 parts by mass of the rubber component, and is preferably 28 parts by mass or less with respect to 100 parts by mass of the rubber component. It is more preferably 22 parts by mass or less, further preferably 18 parts by mass or less, and particularly preferably 15 parts by mass or less.
  • the kind and molecular weight of the polyolefin softener are the same as those described in the rubber composition of the present invention described above.
  • the components other than the rubber component, the filler, and the polyolefin-based softening agent contained in the rubber composition for a base tread of the present invention are not particularly limited. It is possible to appropriately contain the same components as the above-mentioned rubber composition of the present invention.
  • the tire of the present invention is characterized by using the above-mentioned rubber composition of the present invention or the above-mentioned rubber composition for a base tread of the present invention.
  • the wet performance can be maintained for a long period of time while being excellent in wet performance, low rolling resistance and steering stability.
  • the tire of the present invention is preferably a pneumatic tire, and as the gas to be filled in the pneumatic tire, in addition to normal air or oxygen-adjusted air, nitrogen, argon, helium or the like inert gas is used. Gas can be used.
  • the tire of the present invention can be used as a tire for various vehicles, it is preferably used as a tire for passenger cars. This is because it is possible to more effectively exhibit both the wet performance, the dry performance, the steering stability, and the long-lasting wet performance.
  • Example 1 The amount of bound styrene, microstructure of butadiene moiety, molecular weight, shrinkage factor (g '), Mooney viscosity, glass transition temperature (Tg), modification rate, presence or absence of nitrogen atom, of silicon atom of the synthesized modified conjugated diene polymer Existence is analyzed by the following method.
  • Amount of bound styrene Using a modified conjugated diene polymer as a sample, 100 mg of the sample is made up to 100 mL with chloroform and dissolved to obtain a measurement sample. The amount of bound styrene (% by mass) with respect to 100% by mass of the sample is measured by the amount of ultraviolet absorption wavelength (near 254 nm) absorbed by the phenyl group of styrene (Shimadzu Corporation's spectrophotometer "UV-2450"). .
  • Mn average molecular weight of the molecular weight distribution (Mw / Mn), a peak top molecular weight of the modified conjugated diene polymer (Mp 1) and a peak top molecular weight of the conjugated diene polymer (Mp 2) and the ratio (Mp 1 / Mp 2 ) and the molecular weight of 200 ⁇ 10 4 or more and 500 ⁇ 10 4 or less are obtained.
  • Mp 1 average molecular weight of the molecular weight distribution
  • Mp 1 peak top molecular weight of the modified conjugated diene polymer
  • Mp 2 peak top molecular weight of the conjugated diene polymer
  • TSKgel SuperMultipore HZ-H (trade name, manufactured by Tosoh Corporation) are connected, and a guard column is connected to a column (trade name, TSKguardcolumn SuperMP (HZ) -H, manufactured by Tosoh Corporation) connected as a guard column.
  • 10 mg of a sample for measurement is dissolved in 10 mL of THF to prepare a measurement solution, 10 ⁇ L of the measurement solution is poured into a GPC measuring device, and measurement is performed under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.
  • the above-mentioned peak top molecular weights (Mp 1 and Mp 2 ) are determined as follows.
  • a peak detected as a component having the highest molecular weight is selected.
  • the molecular weight corresponding to the maximum value of the peak is calculated and used as the peak top molecular weight.
  • the ratio of the above-mentioned molecular weight of 200 ⁇ 10 4 or more and 500 ⁇ 10 4 or less is calculated by subtracting the ratio of the molecular weight of less than 200 ⁇ 10 4 from the ratio of the molecular weight of 500 ⁇ 10 4 or less to the whole from the integrated molecular weight distribution curve. To do.
  • the eluent uses THF containing 5 mmol / L triethylamine.
  • the product names “TSKgel G4000HXL”, “TSKgel G5000HXL”, and “TSKgel G6000HXL” manufactured by Tosoh Corporation are connected and used.
  • Mooney viscosity Using a conjugated diene polymer or a modified conjugated diene polymer as a sample, a Mooney viscometer (trade name "VR1132" manufactured by Ueshima Seisakusho) is used, and an L-shaped rotor is used in accordance with JIS K6300. Measure Mooney viscosity. The measurement temperature is 110 ° C. when a conjugated diene-based polymer is used as a sample, and 100 ° C. when a modified conjugated diene-based polymer is used as a sample. First, after preheating the sample at the test temperature for 1 minute, the rotor is rotated at 2 rpm and the torque after 4 minutes is measured to obtain the Mooney viscosity (ML (1 + 4) ).
  • Glass transition temperature (Tg) Using the modified conjugated diene polymer as a sample and using a differential scanning calorimeter “DSC3200S” manufactured by Mac Science Co., Ltd., in accordance with ISO 22768: 2006, under flow of helium of 50 mL / min, from ⁇ 100 ° C. to 20 ° C./min. The DSC curve is recorded while the temperature is being raised at, and the peak top (Infection point) of the DSC differential curve is taken as the glass transition temperature.
  • DSC3200S differential scanning calorimeter
  • the modified conjugated diene polymer is used as a sample, and the property that the modified basic polymer component is adsorbed is applied to a GPC column having a silica gel as a packing material.
  • the amount of adsorption of the sample and the sample solution containing the low-molecular-weight internal standard polystyrene on the silica-based column was determined from the difference between the chromatogram measured on the polystyrene-based column and the chromatogram measured on the silica-based column, and the denaturation rate was determined.
  • sample solution is prepared by dissolving 10 mg of a sample and 5 mg of standard polystyrene in 20 mL of THF.
  • GPC measurement conditions using a polystyrene column 10 ⁇ L of a sample solution was injected into the apparatus using 5 mL / L of THF containing triethylamine as an eluent using a trade name “HLC-8320GPC” manufactured by Tosoh Corporation, and a column oven was used.
  • a chromatogram is obtained using an RI detector at a temperature of 40 ° C. and a THF flow rate of 0.35 mL / min.
  • TSKgel SuperMultipore HZ-H (trade name, manufactured by Tosoh Corporation) are connected, and a guard column is connected to a column (trade name, TSKguardcolumn SuperMP (HZ) -H, manufactured by Tosoh Corporation) connected as a guard column.
  • GPC measurement conditions using a silica-based column Tosoh's product name "HLC-8320GPC” was used, THF was used as an eluent, and 50 ⁇ L of the sample solution was injected into the apparatus, the column oven temperature was 40 ° C, and the THF flow rate was A chromatogram is obtained using an RI detector at 0.5 ml / min.
  • the column is used by connecting the trade names “Zorbax PSM-1000S”, “PSM-300S”, and “PSM-60S”, and the trade name “DIOL 4.6 ⁇ 12.5 mm 5micron” as a guard column at the front stage. Connect and use.
  • the inner volume is 10 L
  • the ratio (L / D) of the inner height (L) to the diameter (D) is 4.0
  • the inlet is at the bottom
  • the outlet is at the top.
  • a tank type pressure vessel having a stirrer as a vessel and a jacket for temperature control is used as a polymerization reactor.
  • a mixture of 1,3-butadiene (17.2 g / min), styrene (10.5 g / min), and n-hexane (145.3 g / min) mixed in advance with water removed therefrom is mixed.
  • n-butyllithium for inert treatment of residual impurities was added at 0.117 mmol / min, mixed, and then added to the bottom of the reaction group. Supply continuously. Further, 2,2-bis (2-oxolanyl) propane as a polar substance is mixed at a rate of 0.019 g / min and n-butyllithium as a polymerization initiator at a rate of 0.242 mmol / min with a stirrer. It was supplied to the bottom of the polymerization reactor to continuously continue the polymerization reaction.
  • the temperature is controlled so that the temperature of the polymerization solution at the outlet at the top of the reactor is 75 ° C.
  • a small amount of the polymer solution before the addition of the coupling agent was withdrawn from the top outlet of the reactor, and an antioxidant (BHT) was added so that the amount became 0.2 g per 100 g of the polymer.
  • BHT antioxidant
  • tetrakis (3-trimethoxysilylpropyl) -1,3-propanediamine diluted to 2.74 mmol / L as a coupling agent was added to the polymer solution flowing out from the outlet of the reactor at 0.0302 mmol / min.
  • oil Simultaneously with the antioxidant, oil (JOMO process NC140 manufactured by JX Nikko Nisseki Energy Co., Ltd.) was continuously added to 10.0 g of the polymer, and mixed with a static mixer. The solvent is removed by steam stripping to obtain a modified SBR2 corresponding to the modified styrene-butadiene rubber (A1-1) of the present invention.
  • the modified SBR2 has a “branching degree” corresponding to the number of branches assumed from the number of functional groups of the coupling agent and the amount added (which can be confirmed from the value of the contraction factor), and one molecule of the coupling agent has The “number of SiOR residues” corresponding to the value obtained by subtracting the number of SiORs subtracted by the reaction from the total number of SiORs is 4.
  • the amount of bound styrene was 10% by mass
  • the amount of vinyl bond in the butadiene portion was 40%
  • the peak molecular weight was 200,000
  • Tg -70 ° C.
  • the neutralization reaction is performed while adjusting the flow rate and maintaining the Na 2 O concentration in the reaction solution in the range of 0.005 to 0.035 mol / liter. During the reaction, the reaction solution begins to become cloudy and the viscosity increases at 46 minutes to form a gel solution. Furthermore, the addition is continued and the reaction is stopped at 100 minutes. The silica concentration in the resulting solution is 60 g / l. Subsequently, sulfuric acid similar to the above is added until the pH of the solution becomes 3, to obtain a silicic acid slurry. The obtained silicic acid slurry is filtered with a filter press and washed with water to obtain a wet cake.
  • the wet cake is dried as a slurry using an emulsifying device by a spray dryer to obtain silica (3).
  • the CTAB of the obtained silica (3) was 180 m 2 / g
  • the ink bottle-like pore index (IB) was 20.0
  • the right side of the formula (I) ( ⁇ 0.36 ⁇ CTAB + 86.8).
  • the value of) is 22.0.
  • Example 1-1 to 1-8 Comparative Examples 1-1 to 1-12>
  • a rubber composition of each sample was produced by kneading in two stages using a normal Banbury mixer. did.
  • a rubber composition of each sample is manufactured by performing kneading in two stages using a normal Banbury mixer. .
  • Each sample of the obtained rubber composition is evaluated for wet grip performance, long-lasting wet grip performance (wet grip performance after abrasion), low rolling resistance and steering stability by the following methods. The results are shown in Table 1.
  • Example 1-1 and Comparative Example 1-1 a vulcanized rubber suitable for a measuring jig having a major axis of 40 mm and a minor axis of 20 mm was prepared and reciprocated by pressing on a fixed wet iron plate road surface. The frictional force sometimes generated was detected by the load cell, and the dynamic friction coefficient was calculated. For Examples 1-2 to 1-8 and Comparative Examples 1-2 to 1-12, the dynamic friction coefficient is calculated under the same conditions. The evaluation is indicated by an index when the dynamic friction coefficient of Comparative Example 1-1 is 100. Table 1 shows the evaluation results. The larger the index value, the higher the wet grip property.
  • Example 1-1 and Comparative Example 1-1 Wet grip performance after abrasion
  • abrasion was caused by pressing the vulcanized rubber on the wet iron plate road surface several tens of times to reciprocate.
  • the load cell again detected the frictional force generated when the vulcanized rubber was pressed against the wet iron plate road surface and reciprocated, the dynamic friction coefficient was calculated, and the wet grip performance after abrasion was evaluated.
  • the dynamic friction coefficient is calculated under the same conditions, and the wet grip performance after abrasion is evaluated.
  • the evaluation is shown as an index when the dynamic friction coefficient of Comparative Example 1-1 is 100. Table 1 shows the evaluation results. The larger the index value, the higher the wet grip property after abrasion.
  • Example 1-1 and Comparative Example 1-1 the loss tangent (tan ⁇ ) of the vulcanized rubber obtained by vulcanizing the rubber composition of each sample at 145 ° C. for 33 minutes. was measured at a temperature of 50 ° C., an initial strain of 2%, a dynamic strain of 1%, and a frequency of 15 Hz with a viscoelasticity measuring machine.
  • Examples 1-2 to 1-8 and Comparative Examples 1-2 to 1-12 the loss tangent (tan ⁇ ) of the vulcanized rubber obtained by vulcanizing the rubber composition of each sample at 145 ° C. for 33 minutes.
  • Example 1-1 and Comparative Example 1-1 the storage elastic modulus (E ′) of the vulcanized rubber obtained by vulcanizing each rubber composition at 145 ° C. for 33 minutes was It was measured with a viscoelasticity measuring instrument under the conditions of a temperature of 25 ° C., an initial strain of 2%, a dynamic strain of 1% and a frequency of 15 Hz.
  • the storage elastic modulus (E ′) of the vulcanized rubber obtained by vulcanizing each rubber composition at 145 ° C. for 33 minutes the storage elastic modulus (E ′) of the vulcanized rubber obtained by vulcanizing each rubber composition at 145 ° C. for 33 minutes.
  • Modified SBR1 Modified styrene styrene butadiene rubber synthesized by the above method, which corresponds to the modified styrene butadiene rubber (A1-2) of the present invention
  • Modified SBR2 Modified styrene styrene butadiene synthesized by the above method It is a rubber and corresponds to the modified styrene-butadiene rubber (A1-1) of the present invention
  • 13 Modified SBR3 The modified styrene-styrene-butadiene rubber synthesized by the above method, and the modified styrene-butadiene rubber (A1- of the present invention Corresponding to 3)
  • Modified SBR4 JSR Corporation, trade name "SL563", modified styrene-butadiene rubber modified with tin tetrachloride, and does not correspond to the modified styrene-butadiene rubber (
  • each sample of the comparative example shows a value inferior to the index value in at least one evaluation item.
  • Example 2 ⁇ Examples 2-1 to 2-12, Comparative Examples 2-1 to 2-18>
  • a rubber composition for a base tread is prepared by using a usual Banbury mixer.
  • the blending amount of each component in Table 2 is the amount (parts by mass) relative to 100 parts by mass of the rubber component.
  • Table 2 shows the results.
  • each sample of the comparative example shows a value inferior to the index value in at least one evaluation item.
  • a rubber composition which, when applied to a tire, can achieve a high level of wet performance, low rolling resistance, and steering stability while maintaining wet performance for a long period of time. Further, according to the present invention, it is possible to provide a tread and a tire which are excellent in wet performance, low rolling resistance and steering stability, and can maintain wet performance for a long period of time. Further, according to the present invention, it is possible to provide a rubber composition for a base tread which, when applied to a tire, can achieve both low rolling resistance, durability and wet performance, and can maintain wet performance for a long time.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Abstract

L'invention a pour objet de fournir une composition de caoutchouc qui, lorsqu'elle est appliquée à un pneumatique, permet de concilier à un niveau élevé des performances sur route humide, une faible résistance au roulement et une stabilité de conduite, et permet simultanément de conserver ses performances sur route humide pour une longue durée. À cet effet, l'objet de l'invention est caractéristique en ce qu'il contient : un composant caoutchouc qui comprend un caoutchouc styrène-butadiène modifié résultant d'une modification par un alkoxysilane comprenant un azote ; 40 parties en masse ou plus à moins de 70 parties en masse d'une charge comprenant une silice pour 100 parties en masse dudit composant caoutchouc ; et 3 à 35% en masse d'un plastifiant à base de polyoléfine de masse moléculaire moyenne en poids (Mw) comprise entre ５０００ et ５００００ pour 100 parties en masse dudit composant caoutchouc.
PCT/JP2019/040136 2018-10-10 2019-10-10 Composition de caoutchouc, bande de roulement, composition de caoutchouc pour bande de roulement de base, et pneumatique Ceased WO2020075830A1 (fr)

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JP2018-192176 2018-10-10
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220026857A (ko) * 2020-08-26 2022-03-07 넥센타이어 주식회사 고무 조성물 및 이의 제조방법
JP2022046101A (ja) * 2020-09-10 2022-03-23 横浜ゴム株式会社 空気入りタイヤ

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JPS5456641A (en) * 1977-10-13 1979-05-07 Mitsubishi Petrochem Co Ltd Thermoplastic resin composition
JP2013067163A (ja) * 2011-08-10 2013-04-18 Bando Chemical Industries Ltd 車両用床シート、車両の床構造体、車両の床構造体の施工方法
JP2013082762A (ja) * 2011-10-06 2013-05-09 Nitto Denko Corp シーリング組成物、複層ガラスおよび太陽電池パネル
JP2014001337A (ja) * 2012-06-20 2014-01-09 Sumitomo Rubber Ind Ltd 高減衰組成物および制震用ダンパ
JP2016011350A (ja) * 2014-06-27 2016-01-21 Ｊｘ日鉱日石エネルギー株式会社 イソブチレン系共重合体およびその製造方法、これを含んでなるゴム組成物および架橋ゴム組成物。
JP2018145241A (ja) * 2017-03-02 2018-09-20 横浜ゴム株式会社 タイヤ用ゴム組成物及び空気入りタイヤ

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Publication number Priority date Publication date Assignee Title
JPS5456641A (en) * 1977-10-13 1979-05-07 Mitsubishi Petrochem Co Ltd Thermoplastic resin composition
JP2013067163A (ja) * 2011-08-10 2013-04-18 Bando Chemical Industries Ltd 車両用床シート、車両の床構造体、車両の床構造体の施工方法
JP2013082762A (ja) * 2011-10-06 2013-05-09 Nitto Denko Corp シーリング組成物、複層ガラスおよび太陽電池パネル
JP2014001337A (ja) * 2012-06-20 2014-01-09 Sumitomo Rubber Ind Ltd 高減衰組成物および制震用ダンパ
JP2016011350A (ja) * 2014-06-27 2016-01-21 Ｊｘ日鉱日石エネルギー株式会社 イソブチレン系共重合体およびその製造方法、これを含んでなるゴム組成物および架橋ゴム組成物。
JP2018145241A (ja) * 2017-03-02 2018-09-20 横浜ゴム株式会社 タイヤ用ゴム組成物及び空気入りタイヤ

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220026857A (ko) * 2020-08-26 2022-03-07 넥센타이어 주식회사 고무 조성물 및 이의 제조방법
KR102424972B1 (ko) 2020-08-26 2022-07-26 넥센타이어 주식회사 고무 조성물 및 이의 제조방법
JP2022046101A (ja) * 2020-09-10 2022-03-23 横浜ゴム株式会社 空気入りタイヤ
JP7545034B2 (ja) 2020-09-10 2024-09-04 横浜ゴム株式会社 空気入りタイヤ

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