WO2020075829A1 - Composition de caoutchouc, bande de roulement, et pneumatique - Google Patents

Composition de caoutchouc, bande de roulement, et pneumatique Download PDF

Info

Publication number
WO2020075829A1
WO2020075829A1 PCT/JP2019/040135 JP2019040135W WO2020075829A1 WO 2020075829 A1 WO2020075829 A1 WO 2020075829A1 JP 2019040135 W JP2019040135 W JP 2019040135W WO 2020075829 A1 WO2020075829 A1 WO 2020075829A1
Authority
WO
WIPO (PCT)
Prior art keywords
mass
rubber
parts
styrene
rubber composition
Prior art date
Application number
PCT/JP2019/040135
Other languages
English (en)
Japanese (ja)
Inventor
健太郎 熊木
Original Assignee
株式会社ブリヂストン
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ブリヂストン filed Critical 株式会社ブリヂストン
Priority to JP2020551238A priority Critical patent/JPWO2020075829A1/ja
Publication of WO2020075829A1 publication Critical patent/WO2020075829A1/fr

Links

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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
    • C08L9/06—Copolymers with styrene

Definitions

  • the present invention relates to a rubber composition, a tread and a tire.
  • dry performance wet performance of a tire and braking performance and drivability
  • dry performance wet performance of a tire and braking performance and drivability
  • styrene-butadiene rubber having a large amount of bound styrene as a rubber component.
  • inorganic filler such as silica
  • an object of the present invention is to provide a rubber composition which, when applied to a tire, can achieve a high level of wet performance, dry performance, and steering stability, and at the same time, can improve fracture characteristics at low temperatures. is there.
  • Another object of the present invention is to provide a tread and a tire which are excellent in wet performance, dry performance, and steering stability and have improved fracture characteristics at low temperatures.
  • 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 styrene-butadiene rubber having a bound styrene content of 30% by mass or more, A filler containing 70 to 150 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 polyolefin-based softening agent contains unmodified polybutene. This is because when applied to a tire, the fracture characteristics at low temperatures can be further improved.
  • the styrene-butadiene rubber is an alkoxysilane-modified styrene-butadiene rubber. This is because when applied to tires, wet performance, dry performance, and steering stability can be achieved at a higher level.
  • the rubber component further contains a modified styrene-butadiene rubber having a bound styrene content of 15% by mass or less. This is because when applied to a tire, it is possible to achieve a higher level of wet performance, dry performance, and steering stability.
  • the rubber component further contains natural rubber. This is because the wet performance can be further enhanced when applied to a tire.
  • 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 it is applied to a tire, the fracture characteristics at low temperatures can be further enhanced, and the workability can be favorably maintained.
  • 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 the wet performance can be further enhanced when applied to a tire.
  • 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 tread of the present invention is characterized by using the above-mentioned rubber composition of the present invention.
  • the tire of the present invention is characterized by using the above-described rubber composition of the present invention in a tread. This is because, by providing the above configuration, the wet performance, the dry performance, and the steering stability are excellent, and the fracture characteristics at low temperatures can be improved.
  • the present invention it is possible to provide a rubber composition capable of achieving a high level of wet performance, dry performance, and steering stability when applied to a tire and improving fracture characteristics at low temperatures. Further, according to the present invention, it is possible to provide a tread and a tire that have excellent wet performance, dry performance, and steering stability, and have improved fracture characteristics at low temperatures.
  • the rubber composition of the present invention comprises a rubber component containing a styrene-butadiene rubber having a bound styrene content of 30% by mass or more, A filler containing 70 to 150 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 bound styrene content of 30% by mass or more is used as the rubber component, and a certain amount of silica is used as a filler to apply the rubber composition to a tire.
  • silica is used as a filler to apply the rubber composition to a tire.
  • the present invention by including a polyolefin softener having a weight average molecular weight (Mw) of 5,000 to 50,000 in the rubber composition, it is possible to impart elasticity to the rubber composition even in a low temperature range. It is possible to improve the breaking characteristics at low temperature while achieving a high level of wet performance, dry performance and steering stability of the tire.
  • Mw weight average molecular weight
  • the tire of the present invention contains a rubber component rubber component containing a styrene-butadiene rubber (hereinafter, also referred to as “styrene-butadiene rubber (A1)”) having a bound styrene content of 30% by mass or more.
  • styrene-butadiene rubber (A1)) having a bound styrene content of 30% by mass or more.
  • the amount of bound styrene of the styrene-butadiene rubber (A1) is required to be 30% by mass or more and is 35% by mass or more from the viewpoint of improving wet performance, dry performance and steering stability of the tire. It is preferable that the content be 39% by mass or more.
  • the amount of bound styrene of the styrene-butadiene rubber (A1) is preferably 60% by mass or less, and more preferably 50% by mass or less, from the viewpoint of maintaining the breaking characteristics at low temperatures.
  • the amount of bound styrene of the styrene-butadiene rubber (A1) can be measured by ultraviolet absorption of a phenyl group, and the amount of bound conjugated diene can also be obtained from this. Specifically, it measures according to the following. Using 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 styrene-butadiene rubber (A1) in the rubber component is preferably 40% by mass or more, more preferably 60% by mass or more. By setting the content to 40% by mass or more, the tire dry performance and steering stability can be improved. On the other hand, the content ratio of the styrene-butadiene rubber (A1) in the rubber component is preferably 90% by mass or less, and more preferably 80% by mass or less, from the viewpoint of maintaining the fracture characteristics at low temperature.
  • the styrene-butadiene rubber (A1) contained in the rubber component is not particularly limited as long as the bound styrene content is 30% by mass or more.
  • modified SBR modified styrene-butadiene rubber
  • the modified styrene-butadiene rubber as the styrene-butadiene rubber (A1) has, for example, a weight average molecular weight of 20 ⁇ 10 4 to 300 ⁇ 10 4 , and a molecular weight of 200 with respect to the total amount of the modified styrene-butadiene rubber. It is possible to use a modified styrene-butadiene rubber having a content of ⁇ 10 4 to 500 ⁇ 10 4 in an amount of 0.25 to 30% by mass and having a shrinkage factor (g ′) of less than 0.64.
  • the weight average molecular weight (Mw) of the modified SBR is preferably 20 ⁇ 10 4 to 300 ⁇ 10 4 , and more preferably 50 ⁇ 10 4 or more, 64 ⁇ 10 4 or more, or 80 ⁇ 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. When the Mw of the modified SBR is 20 ⁇ 10 4 or more, the wet performance, dry performance, steering stability and low rolling resistance of the tire can be highly compatible. When 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 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 (also referred to as “specific high molecular weight component” in the present specification). ) In an amount of 0.25 to 30% by mass. When the content of the specific high molecular weight component is within this range, the wet performance and dry steering stability of the tire and low rolling resistance can be highly compatible.
  • 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 has a specific high molecular weight component of 1.0% by mass or more, 1.4% by mass or more, 1.75% by mass or more, 2.0% by mass or more, 2.15% by mass or more, Alternatively, it contains 2.5 mass% or more.
  • 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 has a molecular weight distribution (Mw / Mn) of 1.6 to 3.0.
  • the contraction factor (g ′) of the modified SBR 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. Is an index of the ratio of the size occupied by the molecule to the linear polymer which is the absolute molecular weight of the polymer. That is, as the degree of branching of the polymer increases, the shrinkage factor (g ′) tends to decrease.
  • 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 a modified SBR as a sample, a GPC measuring device (trade name “GPCmax VE-2001” manufactured by Malvern Co., Ltd.) in which three columns having polystyrene gel as a packing material are connected, and a light scattering detector and an RI detector are used. , A viscosity detector (trade name "TDA305” manufactured by Malvern Co., Ltd.) was used in order to measure, and based on standard polystyrene, absolute values were obtained from the results of the light scattering detector and RI detector. For the molecular weight, 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 is preferably 10 parts by mass or less based on 100 parts by mass of the modified SBR. More preferably, it is more than 0 parts by mass and 10 parts by mass or less. When the amount of the extending oil is 10 parts by mass or less, the wet performance, dry performance and steering stability of the tire can be highly balanced. If 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 has a branch and a branching degree of 5 or more.
  • the modified SBR has one or more coupling residues and a styrene-butadiene rubber chain bonded to the coupling residues, and further, the branch is for the coupling residue of 1 More preferably, it contains 5 or more branches in which the styrene-butadiene rubber chains are bonded.
  • the modified SBR has a branch and a branching degree of 6 or more.
  • the modified SBR has one or more coupling residues and a styrene-butadiene rubber chain bonded to the coupling residues, and further, the branch is for the coupling residue of 1 More preferably, it contains 6 or more branches having the styrene-butadiene rubber chain bonded thereto.
  • the contraction factor (g ') can be 0.63 or less.
  • the modified SBR has a branch, and it is more preferable that the degree of branching is 7 or more, further preferably 8 or more.
  • the upper limit of the branching degree is not particularly limited, but is preferably 18 or less.
  • the modified SBR has one or more coupling residues and an SBR chain that binds to the coupling residue, and further, the branch is 7 for the coupling residue of 1. It is even more preferable to include a branch to which the SBR chain is bound, and it is particularly preferable to include a branch to which eight or more SBR chains are bound to one coupling residue.
  • the contraction factor (G ') can be 0.59 or less.
  • the modified SBR in the 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 as the 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 when there are a pluralit
  • A is a hydrocarbon group having 1 to 20 carbon atoms, or an oxygen atom or a nitrogen atom.
  • 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, and 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 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 preferably has a nitrogen atom and a silicon atom.
  • the processability of the rubber composition is improved, and when applied to a tire, the wear resistance of the tire and the low rolling resistance can be made compatible to a higher degree.
  • the modified SBR is more preferably an alkoxysilane-modified (having an alkoxysilyl group) modified SBR.
  • the component (A1) has a nitrogen atom
  • the fact that the modified SBR has a silicon atom is judged by the following method. 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 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 is preferably 35% by mass or more, more preferably 37% by mass or more, further preferably 39% by mass or more, and 40% by mass or more. Is particularly preferred. When the amount of bound styrene in the modified SBR is 35% by mass or more, when applied to a tire, abrasion resistance and low rolling resistance can be more highly compatible. Further, 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 deterioration of the low temperature embrittlement performance due to the increase of the elastic modulus at low temperature is suppressed.
  • 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 vinyl bond content in the conjugated diene bond unit is, for example, preferably 35 mol% or more, more preferably 37 mol% or more, and further preferably 39 mol% or more, It is particularly preferably 40 mol% or more.
  • the vinyl bond content in the conjugated diene bond unit is 35 mol% or more, when applied to a tire, the wet performance, dry performance and steering stability of the tire can be more highly compatible.
  • the vinyl bond content in the conjugated diene bond unit of the modified SBR is preferably 60 mol% or less, more preferably 55 mol% or less, further preferably 50 mol% or less, 45 It is particularly preferably not more than mol%. This is because the deterioration of the low temperature embrittlement performance due to the increase of the elastic modulus at low temperature is suppressed.
  • 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 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 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 increasing the temperature in a predetermined temperature range, and the peak top (Influence 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 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 S-modified SBR as a sample, a Mooney viscometer (trade name “VR1132” manufactured by Ueshima Seisakusho) is used, and the Mooney viscosity is measured 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, the sample is preheated 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 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, and an activity of the styrene-butadiene rubber
  • a polymerization step of polymerizing at least butadiene using an organic monolithium compound as a polymerization initiator to obtain a styrene-butadiene rubber, and an activity of the 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”) to the terminal.
  • 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 having 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 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 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 is a styrene-butadiene rubber represented by the following general formula (VI): [In the 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, and R 15 , R 16 , R 17 , R 18 and R 20.
  • 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 are independently present when a plurality of them are present.
  • 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]. This is because the wet performance, the dry performance, and the steering stability can be more highly compatible with each other.
  • 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 SBR has a molecular weight distribution (Mw / Mn) of 1.5 to 2.5, or 1.8 to 2.2. Moreover, it is preferable that the obtained component (A1) has a single peak in the molecular weight curve by GPC. In one example, when the peak molecular weight of the component (A1) by GPC is Mp 1 and the peak molecular weight of 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 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 is used as a sample and applied to a GPC column having a silica gel as a packing material, and the property of adsorbing the modified basic polymer component is applied.
  • 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 is, for example, 2,6-di-tert-butyl-4-hydroxytoluene (BHT) or n-octadecyl from the viewpoint of preventing gel formation after polymerization and improving stability during processing. It is preferable to add an antioxidant such as -3- (4'-hydroxy-3 ', 5'-di-tert-butylphenol) propinate and 2-methyl-4,6-bis [(octylthio) methyl] phenol. .
  • Extending oil may be added to the modified styrene-butadiene rubber, if necessary, in order to further improve the processability of the modified SBR.
  • Examples of the method of adding the extension oil to the modified styrene-butadiene rubber include a method of adding the extension oil to the polymer solution and mixing them to desolvate the oil-extended copolymer solution.
  • a known method can be used.
  • 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.
  • the modified SBR as the styrene-butadiene rubber (A1) has the above-mentioned modified SBR (weight average molecular weight of 20 ⁇ 10 4 to 300 ⁇ 10 4 and a molecular weight relative to the total amount of the modified styrene-butadiene rubber). It is also possible to use a modified SBR other than the modified styrene-butadiene rubber of 200 ⁇ 10 4 to 500 ⁇ 10 4 in which the contraction factor (g ′) is less than 0.64). it can.
  • the modified (co) polymer as the polymer component P2 of WO 2017/0777712 and the modified polymer E described in the examples may be mentioned.
  • modified styrene-butadiene rubber in addition to the above-mentioned styrene-butadiene rubber (A1) having a bound styrene content of 30 mass% or more, a modified styrene-butadiene rubber having a bound styrene content of 15 mass% or less (hereinafter, referred to as “modified styrene-butadiene rubber”). It is preferable to further contain rubber (A2) "or" modified SBR (A2) ".
  • the wet performance, dry performance of the tire It is possible to achieve good balance between handling stability and breaking characteristics at low temperatures.
  • the modified SBR (A2) can be composed of, for example, one kind or two or more kinds of modified styrene butadiene rubber.
  • the type of the modified SBR (A2) 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, dry performance, steering stability, and fracture characteristics at low temperatures of the tire can be well balanced.
  • modified SBR (A2) examples include a modified (co) polymer as the polymer component P2 in WO 2017/0777712, and modified polymers C and D described in Examples. Is mentioned.
  • the content of the modified SBR (A2) in the rubber component is not particularly limited, but from the viewpoint of achieving a higher level of tire wet performance, wear resistance, 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 styrene-butadiene rubber (A1) and the modified styrene-butadiene rubber (A2) described above.
  • 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.
  • the wet performance when applied to can be further improved.
  • the wear resistance of the tire and the crack growth resistance can be improved.
  • the content of the natural rubber in the rubber component is not particularly limited, but is preferably 20% by mass or more and 30% by mass or more from the viewpoint of improving the wet performance of the tire. More preferable. From the viewpoint of maintaining the dry performance and steering stability of the tire at a high level, the content of the natural rubber in the rubber component is preferably 50% by mass or less.
  • the rubber composition of the present invention contains a filler in addition to the rubber component described above.
  • the filler contains 70 to 150 parts by mass of silica based on 100 parts by mass of the rubber component.
  • the content of the silica needs to be 70 to 150, preferably 80 to 140 parts by mass, and more preferably 90 to 130 parts by mass with respect to 100 parts by mass of the rubber component.
  • the content of the silica is 70 parts by mass or more with respect to 100 parts by mass of the rubber component, wet performance and abrasion resistance can be sufficiently improved. It is also possible to suppress deterioration of processability 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 CTAB means a value measured according to ASTM D3765-92.
  • ASTM D3765-92 is a method for measuring CTAB of carbon black
  • CE-TRAB cetyl trimethyl ammonium bromide
  • silica OT sodium di-2-ethylhexyl sulfosuccinate
  • 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 breaking characteristics can be maintained at a high level.
  • 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 weight average molecular weight to 50,000 or less.
  • the reason for this is that when it is 5000 or more, the occurrence of bleeding after application to a tire can be prevented.
  • the weight average molecular weight (Mw) of the polyolefin-based softening agent is preferably 5000 to 28000, more preferably 5500 to 18000, further preferably 5500 to 15000, and more preferably 5500 to Particularly preferred is 10,000, and most preferred is 6,000 to 9,500.
  • 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.
  • 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 is required 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 terpine oil obtained at the same time when rosin is obtained from a pine tree, or by blending a polymerization component separated therefrom, and polymerized 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” series manufactured by Hercules Co., Ltd. (A115, S115, etc.) and the like.
  • 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 e.g., a low-temperature softening agent other than the above-mentioned polyolefin-based 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.
  • the tire of the present invention is characterized by using the above-described rubber composition of the present invention in a tread.
  • By providing the above-mentioned structure it is possible to improve not only the wet performance, the dry performance and the steering stability but also the breaking characteristics at low temperature.
  • the tire of the present invention may be vulcanized after molding using an unvulcanized rubber composition depending on the type of tire to be applied, and may be molded using a semi-vulcanized rubber that has undergone a preliminary vulcanization step or the like. After that, the main vulcanization may be further carried out for production.
  • 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 air whose oxygen partial pressure is adjusted, inert gas such as nitrogen, argon, helium, etc. 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 the wet performance, the dry performance, and the steering stability are excellent, and the destruction characteristics at low temperatures can be more effectively exhibited.
  • the amount of bound styrene, the microstructure of the butadiene portion, the molecular weight, the shrinkage factor (g '), the Mooney viscosity, the glass transition temperature (Tg), the modification rate, the presence or absence of nitrogen atoms, and the 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 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 is applied to a GPC column having a silica gel as a filler to apply the property of adsorbing the modified basic polymer component.
  • 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 vigorously mixed with a stirrer at a rate of 0.019 g / min and n-butyllithium as a polymerization initiator at a rate of 0.242 mmol / min. 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 styrene-butadiene rubber (A1) 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. Further, the addition is continued to stop the reaction 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.
  • silica (2) was dried as a slurry using an emulsifying apparatus by a spray dryer to obtain silica (2).
  • the obtained silica (2) had a CTAB of 180 m 2 / g, an ink bottle-like pore index (IB) of 20.0, and the right side of the formula (I) ( ⁇ 0.36 ⁇ CTAB + 86.8). The value of) is 22.0.
  • 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 30 minutes to form a gel solution. Further, the addition is continued to stop the reaction at 100 minutes. The silica concentration in the resulting solution is 85 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 79 m 2 / g
  • the ink bottle-like pore index (IB) was 55.0
  • the right side of the formula (I) ( ⁇ 0.36 ⁇ CTAB + 86.8).
  • the value of) is 58.0.
  • Example 1 and Comparative Example 1 vulcanized rubber suitable for a measuring jig having a major axis of 40 mm and a minor axis of 20 mm is prepared, and is generated when the vulcanized rubber is pressed against a fixed wet iron plate road surface to reciprocate.
  • the frictional force was detected by the load cell and the dynamic friction coefficient was calculated.
  • the dynamic friction coefficient is calculated under the same conditions.
  • the evaluation is indicated by an index when the resistance value of Comparative Example 1 is 100. Table 1 shows the evaluation results. The larger the index value, the higher the wet grip property.
  • Example 1 Dry Grip Performance
  • a vulcanized rubber suitable for a measuring jig having a major axis of 40 mm and a minor axis of 20 mm is prepared, and is generated when the vulcanized rubber is pressed against a fixed dry iron plate road surface to reciprocate.
  • the frictional force was detected by the load cell and the dynamic friction coefficient was calculated.
  • the dynamic friction coefficient is calculated under the same conditions.
  • the evaluation is displayed as an index when the dynamic friction coefficient of Comparative Example 1 is 100. Table 1 shows the evaluation results. The larger the index value, the better the dry grip property.
  • Example 1 and Comparative Example 1 the storage elastic modulus (E ′) of the vulcanized rubber obtained by vulcanizing each rubber composition at 145 ° C. for 33 minutes was measured by viscoelasticity. With a machine, the temperature was 25 ° C., the initial strain was 2%, the dynamic strain was 1%, and the frequency was 15 Hz.
  • the storage elastic modulus (E ′) of the vulcanized rubber obtained by vulcanizing each rubber composition at 145 ° C. for 33 minutes was measured by a viscoelasticity measuring machine. The temperature is 25 ° C., the initial strain is 2%, the dynamic strain is 1%, and the frequency is 15 Hz.
  • the evaluation is displayed as an index when E ′ of Comparative Example 1 is 100. The evaluation results are shown in Table 1. The larger the index value, the better the steering stability of the tire.
  • Tb Th + ⁇ T (S / 100-1 / 2)
  • Tb Impact embrittlement temperature (° C)
  • Th Maximum temperature at which all test pieces break (° C)
  • ⁇ T Test temperature interval (° C)
  • S Sum of percentages of fracture at each temperature from the lowest temperature at which all test pieces do not fracture to Th The lower the impact embrittlement temperature Tb, the better the fracture characteristics at low temperature.
  • Modified SBR1 Modified styrene-styrene-butadiene rubber synthesized by the above method, corresponding to the styrene-butadiene rubber (A1) in the present invention * 12
  • Modified SBR2 Modified styrene-styrene-butadiene rubber synthesized by the above method * 13
  • Modified SBR3 corresponding to the styrene-butadiene rubber (A1) of the present invention: Modified styrene-styrene-butadiene rubber synthesized by the above method and corresponding to the modified styrene-butadiene rubber (A2) of the present invention
  • Modified SBR4 JSR Corporation, trade name "SL563", corresponding to the modified styrene-butadiene rubber (A2) of the present invention * 15
  • each sample of the comparative example shows a value inferior to the index value in at least one evaluation item.
  • the present invention it is possible to provide a rubber composition capable of achieving a high level of wet performance, dry performance, and steering stability when applied to a tire and improving fracture characteristics at low temperatures. Further, according to the present invention, it is possible to provide a tread and a tire that have excellent wet performance, dry performance, and steering stability, and have improved fracture characteristics at low temperatures.

Landscapes

  • 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)
  • Compositions Of Macromolecular Compounds (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 sèche et une stabilité de conduite, et permet simultanément une amélioration en termes de caractéristiques de cassure à basse température. À cet effet, l'objet de l'invention est caractéristique en ce qu'il contient : un composant caoutchouc qui comprend un caoutchouc styrène-butadiène de teneur en styrène lié supérieure ou égale à 30% en masse ; 70 à 150 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/JP2019/040135 2018-10-10 2019-10-10 Composition de caoutchouc, bande de roulement, et pneumatique WO2020075829A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2020551238A JPWO2020075829A1 (ja) 2018-10-10 2019-10-10 ゴム組成物、トレッド及びタイヤ

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-192174 2018-10-10
JP2018192174 2018-10-10

Publications (1)

Publication Number Publication Date
WO2020075829A1 true WO2020075829A1 (fr) 2020-04-16

Family

ID=70165024

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/040135 WO2020075829A1 (fr) 2018-10-10 2019-10-10 Composition de caoutchouc, bande de roulement, et pneumatique

Country Status (2)

Country Link
JP (1) JPWO2020075829A1 (fr)
WO (1) WO2020075829A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023106081A1 (fr) * 2021-12-07 2023-06-15 横浜ゴム株式会社 Composition de caoutchouc pour pneu

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH115874A (ja) * 1997-06-17 1999-01-12 Yokohama Rubber Co Ltd:The ゴム組成物
JP2012102249A (ja) * 2010-11-10 2012-05-31 Bridgestone Corp ゴム組成物及びそれを用いた空気入りタイヤ
JP2014136759A (ja) * 2013-01-17 2014-07-28 Jx Nippon Oil & Energy Corp ゴム組成物
JP2018095701A (ja) * 2016-12-09 2018-06-21 住友ゴム工業株式会社 ゴム組成物及び空気入りタイヤ
JP2018095763A (ja) * 2016-12-15 2018-06-21 東洋ゴム工業株式会社 ゴム組成物
JP2018135462A (ja) * 2017-02-22 2018-08-30 住友ゴム工業株式会社 タイヤ用ゴム組成物及び空気入りタイヤ

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH115874A (ja) * 1997-06-17 1999-01-12 Yokohama Rubber Co Ltd:The ゴム組成物
JP2012102249A (ja) * 2010-11-10 2012-05-31 Bridgestone Corp ゴム組成物及びそれを用いた空気入りタイヤ
JP2014136759A (ja) * 2013-01-17 2014-07-28 Jx Nippon Oil & Energy Corp ゴム組成物
JP2018095701A (ja) * 2016-12-09 2018-06-21 住友ゴム工業株式会社 ゴム組成物及び空気入りタイヤ
JP2018095763A (ja) * 2016-12-15 2018-06-21 東洋ゴム工業株式会社 ゴム組成物
JP2018135462A (ja) * 2017-02-22 2018-08-30 住友ゴム工業株式会社 タイヤ用ゴム組成物及び空気入りタイヤ

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023106081A1 (fr) * 2021-12-07 2023-06-15 横浜ゴム株式会社 Composition de caoutchouc pour pneu
JP7294393B1 (ja) 2021-12-07 2023-06-20 横浜ゴム株式会社 タイヤ用ゴム組成物
JP2023089331A (ja) * 2021-12-07 2023-06-28 横浜ゴム株式会社 タイヤ用ゴム組成物

Also Published As

Publication number Publication date
JPWO2020075829A1 (ja) 2021-09-24

Similar Documents

Publication Publication Date Title
JPWO2018186367A1 (ja) ゴム組成物及びタイヤ
JP7288861B2 (ja) ゴム組成物及びタイヤ
JP6880084B2 (ja) 樹脂延伸ゴム及び調製するためのプロセス
JP2020100677A (ja) タイヤ
JP2020059778A (ja) ゴム組成物、トレッド及びタイヤ
JPWO2019117266A1 (ja) ゴム組成物及びタイヤ
WO2020075829A1 (fr) Composition de caoutchouc, bande de roulement, et pneumatique
WO2020071557A1 (fr) Composition de caoutchouc, caoutchouc de bande de roulement et pneu
WO2020075830A1 (fr) Composition de caoutchouc, bande de roulement, composition de caoutchouc pour bande de roulement de base, et pneumatique
JPWO2019117093A1 (ja) ゴム組成物及びタイヤ
JP7158988B2 (ja) タイヤ
JP7402812B2 (ja) タイヤ
WO2020075831A1 (fr) Pneumatique
WO2019244850A1 (fr) Composition de caoutchouc et pneu
JP2021098758A (ja) ゴム組成物及びタイヤ
JP7496295B2 (ja) ゴム組成物及びタイヤ
JP2021098759A (ja) ゴム組成物およびタイヤ
US20240182697A1 (en) Rubber composition and tire
WO2024090556A1 (fr) Composition polymère et pneumatique
WO2022249766A1 (fr) Composition de caoutchouc pour pneu, caoutchouc de bande de roulement et pneu
JP2020176209A (ja) ゴム組成物及びタイヤ
WO2022196643A1 (fr) Polymère de diène conjugué et procédé de production associé, composition polymère, produit réticulé, et pneu
WO2021200098A1 (fr) Pneu
JP2022088912A (ja) ゴム組成物及びタイヤ
JP2022088917A (ja) ゴム組成物及びタイヤ

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19871772

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2020551238

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19871772

Country of ref document: EP

Kind code of ref document: A1