Rubber composition and tire containing organopolysiloxane

Abstract

To provide a rubber composition that is excellent in terms of hardness, tensile property, rolling resistance, and wet gripping and achieves a desired fuel-saving tire.SOLUTION: A rubber composition includes an organopolysiloxane represented by the following average composition formula (1), a diene rubber and a filler. (R1)a(R2)b(OR3)c(R4)dSiO(4-2a-b-c-d) / 2 (1) (where R1 independently represent a sulfide group-containing bivalent organic group, R2 independently represent a C6-10 aryl group or a C7-10 aralkyl group, R3 independently represent a hydrogen atom, a C1-20 alkyl group, a C6-10 aryl group, a C7-10 aralkyl group, or a C2-10 alkenyl group, R4 independently represent a C1-12 alkyl group, and a, b, c and d each represent a number satisfying 0<2a<1, 0<b<1, 0<c<3, 0≤d<1, and 0<2a+b+c+d<4).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a rubber composition and a tire containing an organopolysiloxane, and more specifically to a rubber composition and a tire containing an organopolysiloxane containing an organic group having a sulfide group and an aryl group or an aralkyl group. [Background technology]

[0002] Sulfur-containing organosilicon compounds are useful as essential components in the manufacture of tires made of silica-filled rubber compositions. Silica-filled tires have excellent performance in automobile applications, particularly excellent wear resistance, rolling resistance and wet grip. Improvement of these performances is closely related to improvement of tire fuel efficiency, and therefore has been actively studied in recent years.

[0003] In order to improve fuel economy, it is essential to increase the silica filling rate of the rubber composition, and although a silica-filled rubber composition reduces the rolling resistance of a tire and improves wet grip, it has a high unvulcanized viscosity, requires multi-stage kneading, etc., and has problems with workability. Therefore, in a rubber composition in which an inorganic filler such as silica is simply blended, the dispersion of the filler is insufficient, and problems arise in that the breaking strength and abrasion resistance are significantly reduced. Therefore, a sulfur-containing organosilicon compound is essential in order to improve the dispersibility of the inorganic filler in the rubber and to chemically bond the inorganic filler to the rubber matrix.

[0004] As sulfur-containing organosilicon compounds, compounds containing an alkoxysilyl group and a polysulfide silyl group in the molecule, such as bis-triethoxysilylpropyl tetrasulfide and bis-triethoxysilylpropyl disulfide, are known to be effective (Patent Documents 1 to 4). In addition to the above-mentioned organosilicon compounds having polysulfide groups, the use of thioester-type organosilicon compounds containing blocked mercapto groups, which are advantageous for the dispersibility of silica, and sulfur-containing organosilicon compounds in which an amino alcohol compound is transesterified with a hydrolyzable silyl group moiety, which is advantageous for affinity with silica through hydrogen bonding, is also known (Patent Documents 5 to 9).

[0005] However, even if the sulfur-containing organosilicon compounds disclosed in the above-mentioned patent documents are used, it is not possible to obtain a rubber composition for tires that realizes the desired fuel efficiency. In addition, these sulfur-containing organosilicon compounds are expensive compared to sulfide-type compounds, and the manufacturing method is complicated, which means that there are problems with productivity, and various other issues remain.

[0006] Furthermore, Patent Documents 10 and 11 disclose examples in which polysiloxanes having a polysulfide group and a long-chain alkyl group are used. When these polysiloxanes are used, the rolling resistance and wet grip performance are improved, but the hardness and tensile properties are reduced, and it has not yet been possible to obtain a rubber composition for tires that achieves the desired low fuel consumption. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2004-525230 [Patent Document 2] JP 2004-18511 A [Patent Document 3] JP 2002-145890 A [Patent Document 4] U.S. Patent No. 6,229,036 [Patent Document 5] JP 2005-8639 A [Patent Document 6] JP 2008-150546 A [Patent Document 7] JP 2010-132604 A [Patent Document 8] Patent No. 4571125 [Patent Document 9] U.S. Pat. No. 6,414,061 [Patent Document 10] Patent No. 5574063 [Patent Document 11] Patent No. 6384338 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a rubber composition and a tire which are excellent in hardness, tensile properties, rolling resistance and wet grip property and can realize a desired low fuel consumption tire. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors have conducted intensive research in order to achieve the above-mentioned object and have found that, when added to a rubber composition, an organopolysiloxane containing a sulfide group-containing organic group, an aryl group or aralkyl group, and a hydrolyzable group and / or a hydroxyl group can improve the rolling resistance and wet grip properties without decreasing the hardness or tensile properties of the cured product, and that this rubber composition can achieve the desired fuel-efficient tire properties, thereby completing the present invention.

[0010] That is, the present invention provides 1. A rubber composition comprising an organopolysiloxane represented by the following average composition formula (1), a diene rubber, and a filler: (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a sulfide group-containing divalent organic group; R 2each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms, R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c and d represent numbers satisfying 0 < 2a < 1, 0 < b < 1, 0 < c < 3, 0 ≦ d < 1, and 0 < 2a + b + c + d < 4.) 2. The rubber composition according to 1, wherein the R 1 is a sulfide group-containing divalent organic group represented by the following average formula (2), [Chemical formula] (In the formula, n each independently represents a number from 1 to 10, x represents a number from 1 to 6, and the dashed line represents a bond.) 3. The rubber composition according to 1 or 2, wherein the R 2 represents a phenyl group, 4. The rubber composition according to any one of 1 to 3, wherein the d represents a number satisfying 0 < d < 1, 5. The rubber composition according to any one of 1 to 4, wherein the R 4 represents an alkyl group having 6 to 12 carbon atoms, 6. A tire formed by molding the rubber composition according to any one of 1 to 5, 7. A cured product of the rubber composition according to any one of 1 to 5, 8. A tire using the cured product of 7, 9. A tire formed by molding a rubber composition containing an organopolysiloxane represented by the following average composition formula (1), (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a sulfide group-containing divalent organic group, R 2each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms, R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c and d represent numbers satisfying 0 < 2a < 1, 0 < b < 1, 0 < c < 3, 0 ≦ d < 1, and 0 < 2a + b + c + d < 4.) 10. A tire using a cured product of a rubber composition containing an organopolysiloxane represented by the following average composition formula (1), (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a divalent organic group containing a sulfide group, R 2 each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms, R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c and d represent numbers satisfying 0 < 2a < 1, 0 < b < 1, 0 < c < 3, 0 ≦ d < 1, and 0 < 2a + b + c + d < 4.) 11. An organopolysiloxane represented by the following average composition formula (1) and having a kinematic viscosity at 25 °C of 2 to 10,000 mm 2 / s, (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO(4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a sulfide group-containing divalent organic group represented by the following average formula (2), and R 2 each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms, and R 3 each independently represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, and R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c, and d represent numbers satisfying 0 < 2a < 1, 0 < b < 1, 0 < c < 3, 0 ≦ d < 1, and 0 < 2a + b + c + d < 4.) [Chemical formula] (In the formula, n each independently represents a number from 1 to 10, x represents a number from 2 to 6, and the dashed line represents a bond.) 12. The organopolysiloxane in which R 2 represents a phenyl group, 13. The organopolysiloxane of 11 or 12 in which d represents a number satisfying 0 < d < 1, 14. Any one of the organopolysiloxanes of 11 to 13 in which R 4 represents an alkyl group having 6 to 12 carbon atoms is provided. [Advantages of the Invention]

[0011] The organopolysiloxane of the present invention has a sulfide group-containing organic group, an aryl group-containing organic group, and a hydrolyzable group and / or a hydroxyl group. A tire formed using a rubber composition containing this organopolysiloxane as a rubber compounding agent can satisfy desired low fuel consumption tire characteristics. [Modes for Carrying Out the Invention]

[0012] Hereinafter, the present invention will be specifically described. [1] Organopolysiloxane The organopolysiloxane according to the present invention is represented by the following average composition formula (1). (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1)

[0013] In the above formula (1), R 1 each independently represents a sulfide group-containing divalent organic group. Examples of the organic group include an alkylene group, an arylene group, and an alkylene group, and an alkylene group having 2 to 20 carbon atoms is preferred, and those represented by the following average formula (2) are more preferred.

[0014] [ka] (In the formula, each n is independently a number from 1 to 10, preferably 1 to 5, x is a number from 1 to 6, preferably 2 to 4, and the dashed line represents a bond.)

[0015] Specific examples of the sulfide group-containing divalent organic group represented by the above formula (2) include groups represented by the following formulas, but are not limited thereto.

[0016] [ka] (In the formula, the dashed lines represent bonds.)

[0017] R 2 each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms. Specific examples of the aryl group having 6 to 10 carbon atoms include phenyl, tolyl, xylyl, and naphthyl groups. Specific examples of the aralkyl group having 7 to 10 carbon atoms include phenylmethyl (benzyl) and phenylethyl groups. Among these, R2 As the alkyl group, a phenyl group is preferable.

[0018] R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-hexyl, n-octyl, n-decyl, and octadecyl groups. Specific examples of the alkenyl group having 2 to 10 carbon atoms include vinyl, propenyl, and pentenyl groups. The aryl group having 6 to 10 carbon atoms and the aralkyl group having 7 to 10 carbon atoms are the same as those in the above R 2 Examples of the groups include the same groups as those exemplified in the above. Among these, R 3 is preferably a hydrogen atom, a methyl group, or an ethyl group, and more preferably an ethyl group. 3 The proportion of hydrogen atoms is R 3 Of the total number, 0 to 30 mol % is preferable, and 0 to 10 mol % is more preferable.

[0019] R 4 Each independently represents an alkyl group having 1 to 12 carbon atoms, and specific examples thereof include the above-mentioned R 3 Among the alkyl groups having 1 to 20 carbon atoms given as examples, those having 1 to 12 carbon atoms are exemplified. Among these, from the viewpoint of improving processability by reducing the viscosity of the rubber composition and further improving fuel economy, R 4 As the alkyl group, an alkyl group having 6 to 12 carbon atoms is preferable.

[0020] a, b, c and d represent the average molar numbers of the respective organic groups when the total molar number of silicon atoms is 1, and represent numbers satisfying 0 < 2a < 1, 0 < b < 1, 0 < c < 3, 0 ≦ d < 1, and 0 < 2a + b + c + d < 4. Preferably, they are numbers satisfying 0.2 ≦ 2a ≦ 0.95, 0.05 ≦ b ≦ 0.8, 1 ≦ c ≦ 2.5, 0 ≦ d ≦ 0.6, and 1.3 ≦ 2a + b + c + d < 4. More preferably, they are numbers satisfying 0.3 ≦ 2a ≦ 0.80, 0.05 ≦ b ≦ 0.6, 1 ≦ c ≦ 2.5, 0.05 ≦ d ≦ 0.5, and 1.5 ≦ 2a + b + c + d < 4.

[0021] In the present invention, the kinematic viscosity at 25°C of the organopolysiloxane measured by a capillary viscometer is preferably 2 to 10,000 mm 2 / s from the viewpoint of processability, and more preferably 10 to 5,000 mm 2 / s.

[0022] The organopolysiloxane of the present invention can be produced, for example, by co-hydrolytic condensation of an organosilicon compound represented by the following general formula (3), an organosilicon compound represented by the following general formula (4), and, if necessary, an organosilicon compound represented by the following general formula (5).

[0023]

Chemical formula

[0024]

Chemical formula

[0025]

Chemical formula

[0026] R 5 The alkyl group having 1 to 12 carbon atoms, the aryl group having 6 to 10 carbon atoms, and the aralkyl group having 7 to 10 carbon atoms are the same as those in the above R 2 and R 4 Among them, R 5 As the alkyl group, an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is more preferable.

[0027] Specific examples of the organosilicon compound represented by the above formula (3) include bis(trimethoxysilylpropyl) tetrasulfide, bis(triethoxysilylpropyl) tetrasulfide, bis(trimethoxysilylpropyl) disulfide, and bis(triethoxysilylpropyl) disulfide. Specific examples of the organosilicon compound represented by the above formula (4) include phenyltriethoxysilane, phenyltrimethoxysilane, phenyldiethoxymethylsilane, and phenyldimethoxymethylsilane. Specific examples of the organosilicon compound represented by the above formula (5) include methyltriethoxysilane, methylethyldiethoxysilane, propyltriethoxysilane, propylmethyldiethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, and decyltriethoxysilane.

[0028] Here, the amount of the organosilicon compounds represented by the above formulas (3), (4) and (5) is selected so that a to d in the above formula (1) are the above-mentioned numbers. Based on the total amount of the organosilicon compounds represented by the formulas (3), (4) and (5), the organosilicon compound represented by the formula (3) is preferably 20 to 95 mol%, more preferably 20 to 90 mol%, the organosilicon compound represented by the formula (4) is preferably 5 to 80 mol%, more preferably 5 to 70 mol%, particularly preferably 5 to 60 mol%, and the organosilicon compound represented by the formula (5) is preferably 0 to 60 mol%, more preferably 5 to 50 mol%.

[0029] The co-hydrolysis condensation can be carried out by a known method. The amount of water used can also be a known amount, and is usually 0.3 to 0.99 mol, preferably 0.4 to 0.8 mol, per mol of the total of hydrolyzable silyl groups in the organosilicon compound.

[0030] In producing the organopolysiloxane of the present invention, an organic solvent may be used as necessary. Specific examples of organic solvents include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, and decane; ether solvents such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; amide solvents such as formamide, dimethylformamide, and N-methylpyrrolidone; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; and alcohol solvents such as methanol, ethanol, and propanol. Among these, ethanol and i-propanol are preferred from the viewpoint of excellent hydrolysis reactivity. When the above-mentioned solvent is used, the amount used is not particularly limited, but is preferably about twice the mass of the above-mentioned organosilicon compound or less, and more preferably about the same mass or less as the organosilicon compound.

[0031] In addition, a catalyst may be used, if necessary, in the production of the organopolysiloxane of the present invention. Specific examples of the catalyst include acidic catalysts such as hydrochloric acid and acetic acid; Lewis acid catalysts such as tetrabutyl orthotitanate and ammonium fluoride; alkali metal salts such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium acetate, potassium acetate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, calcium carbonate, sodium methoxide, and sodium ethoxide; and amine compounds such as triethylamine, tributylamine, pyridine, and 4-dimethylaminopyridine. Hydrochloric acid, for example, can be used as a catalyst for the hydrolysis reaction (and / or partial condensation) of silanes, and potassium hydroxide, for example, can be used as a catalyst for the condensation (oligomerization) of silanols. From the viewpoint of excellent reactivity, the amount of catalyst (when a catalyst for the silane hydrolysis reaction and a catalyst for the silanol condensation reaction are used in combination, the amount of each) is preferably 0.001 to 0.05 (unit: molar equivalent) per mole of the total of hydrolyzable silyl groups in the organosilicon compound.

[0032] The reaction conditions for the cohydrolytic condensation are usually 20 to 100° C., preferably 60 to 85° C., and usually 30 minutes to 20 hours, preferably 1 minute to 10 hours.

[0033] [2] Rubber composition The rubber composition of the present invention contains the organopolysiloxane (A) represented by the above formula (1), and may further contain a diene rubber (B) and a filler (C). The amount of organopolysiloxane (A) represented by the above formula (1) is preferably 3 to 20 parts by mass, and more preferably 5 to 12 parts by mass, per 100 parts by mass of filler (C) described below, taking into consideration the physical properties of the resulting rubber and the balance between the degree of effect exerted and economic efficiency.

[0034] As the diene rubber (B), any rubber that has been generally used in various rubber compositions can be used, and specific examples thereof include natural rubber (NR); various isoprene rubbers (IR), various styrene-butadiene copolymer rubbers (SBR), various polybutadiene rubbers (BR), acrylonitrile-butadiene copolymer rubbers (NBR), and other diene rubbers, which may be used alone or in combination of two or more. In addition to diene rubbers, non-diene rubbers such as butyl rubber (IIR) and ethylene-propylene copolymer rubbers (EPR, EPDM) can also be used in combination.

[0035] Examples of the filler (C) include silica, talc, clay, aluminum hydroxide, magnesium hydroxide, calcium carbonate, titanium oxide, etc. Among these, silica is preferred, and the rubber composition of the present invention is more preferably used as a silica-containing rubber composition. In this case, taking into consideration the physical properties of the resulting rubber and the balance between the degree of effect exerted and economic efficiency, the amount of filler (C) to be compounded is preferably 5 to 200 parts by mass, and more preferably 30 to 120 parts by mass, per 100 parts by mass of diene rubber.

[0036] In addition to the above components (A) to (C), the rubber composition of the present invention may contain various additives that are generally used in tires and other general rubbers, such as carbon black, vulcanizing agents, crosslinking agents, vulcanization accelerators, crosslinking accelerators, various oils, antioxidants, plasticizers, etc. The amounts of these additives may be conventional amounts, provided that they do not violate the object of the present invention.

[0037] The rubber composition of the present invention can be obtained by adding the organopolysiloxane (A), the filler (C) and other components to the diene rubber (B) and kneading them in a conventional manner.

[0038] [3] Rubber products (tires) The rubber composition of the present invention can be used for producing rubber products, such as tires, by preparing a composition from the above-mentioned components (A) to (C) and other components by a general method, and vulcanizing or crosslinking the composition. In particular, when producing tires, it is preferable that the rubber composition of the present invention is used in the tread.

[0039] A tire obtained by using the rubber composition of the present invention has a significantly reduced rolling resistance and also has a significantly improved abrasion resistance, and therefore can achieve the desired low fuel consumption. The structure of the tire may be a conventionally known structure, and the manufacturing method may be a conventionally known manufacturing method. In the case of a gas-filled tire, the gas to be filled in the tire may be normal air, air with an adjusted oxygen partial pressure, or an inert gas such as nitrogen, argon, or helium. EXAMPLES

[0040] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, "parts" means parts by mass, and the viscosity is a value measured at 25°C using a capillary kinetic viscometer.

[0041] [1] Synthesis of organopolysiloxane [Example 1-1] A 1 L separable flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 539 g (1.0 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, manufactured by Shin-Etsu Chemical Co., Ltd.), 192 g (0.8 mol) of phenyltriethoxysilane (KBE-103, manufactured by Shin-Etsu Chemical Co., Ltd.) and 200 g of ethanol, and then 25.2 g of 0.5 N hydrochloric acid (1.4 mol of water) was added dropwise at room temperature. The mixture was then stirred at 80°C for 10 hours. Thereafter, 3.0 g of propylene oxide was added dropwise and the mixture was stirred at 80°C for 2 hours. The mixture was then concentrated under reduced pressure and filtered to obtain a final product with a viscosity of 240 mm. 2 The organopolysiloxane obtained was represented by the following average composition formula: (-C 3 H 6 -S 4 -C 3 H 6 -) 0.36 (-C 6 H 5 ) 0.28 (-OC 2 H 5 ) 2.00 SiO 0.50

[0042] [Example 1-2] In a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 539 g (1.0 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, Shin-Etsu Chemical Co., Ltd.), 96 g (0.4 mol) of phenyltriethoxysilane (KBE-103, Shin-Etsu Chemical Co., Ltd.), 83 g (0.4 mol) of propyltriethoxysilane (KBE-3033, Shin-Etsu Chemical Co., Ltd.), and 200 g of ethanol were placed, and then 25.2 g of 0.5 N hydrochloric acid (1.4 mol of water) was dropped at room temperature. The mixture was then stirred at 80° C. for 10 hours. Thereafter, 3.0 g of propylene oxide was dropped and the mixture was stirred at 80° C. for 2 hours. The mixture was then concentrated under reduced pressure and filtered to obtain a solution with a viscosity of 150 mm. 2 The organopolysiloxane obtained was represented by the following average composition formula: (-C 3 H 6 -S 4 -C 3 H 6 -) 0.36 (-C 6 H 5 ) 0.14 (-C 3 H 7 ) 0.14 (-OC 2 H 5 ) 2.00 SiO 0.50

[0043] [Examples 1-3] In a 1 L separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 539 g (1.0 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, Shin-Etsu Chemical Co., Ltd.), 96 g (0.4 mol) of phenyltriethoxysilane (KBE-103, Shin-Etsu Chemical Co., Ltd.), 99 g (0.4 mol) of hexyltriethoxysilane (KBE-3063, Shin-Etsu Chemical Co., Ltd.), and 200 g of ethanol were placed, and then 25.2 g of 0.5 N hydrochloric acid (1.4 mol of water) was dropped at room temperature. The mixture was then stirred at 80° C. for 10 hours. Thereafter, 3.0 g of propylene oxide was dropped and the mixture was stirred at 80° C. for 2 hours. The mixture was then concentrated under reduced pressure and filtered to obtain a solution with a viscosity of 120 mm. 2 The organopolysiloxane obtained was represented by the following average composition formula: (-C 3 H 6 -S 4 -C 3 H 6 -) 0.36 (-C 6 H 5 ) 0.14 (-C 6 H 13 ) 0.14 (-OC 2 H 5 ) 2.00 SiO 0.50

[0044] [Examples 1-4] In a 1 L separable flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, 539 g (1.0 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, Shin-Etsu Chemical Co., Ltd.), 96 g (0.4 mol) of phenyltriethoxysilane (KBE-103, Shin-Etsu Chemical Co., Ltd.), 111 g (0.4 mol) of octyltriethoxysilane (KBE-3083, Shin-Etsu Chemical Co., Ltd.), and 200 g of ethanol were placed, and then 25.2 g of 0.5 N hydrochloric acid (1.4 mol of water) was added dropwise at room temperature. The mixture was then stirred at 80° C. for 10 hours. Then, 3.0 g of propylene oxide was added dropwise, and the mixture was stirred at 80° C. for 2 hours. The mixture was then concentrated under reduced pressure and filtered to obtain a solution with a viscosity of 80 mm.2 The organopolysiloxane obtained was represented by the following average composition formula: (-C 3 H 6 -S 4 -C 3 H 6 -) 0.36 (-C 6 H 5 ) 0.14 (-C 8 H 17 ) 0.14 (-OC 2 H 5 ) 2.00 SiO 0.50

[0045] [Examples 1-5] In a 1 L separable flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer, 539 g (1.0 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, Shin-Etsu Chemical Co., Ltd.), 48 g (0.2 mol) of phenyltriethoxysilane (KBE-103, Shin-Etsu Chemical Co., Ltd.), 166 g (0.6 mol) of octyltriethoxysilane (KBE-3083, Shin-Etsu Chemical Co., Ltd.), and 200 g of ethanol were placed, and then 25.2 g of 0.5 N hydrochloric acid (1.4 mol of water) was dropped at room temperature. The mixture was then stirred at 80° C. for 10 hours. Then, 3.0 g of propylene oxide was dropped and stirred at 80° C. for 2 hours. The mixture was concentrated under reduced pressure and filtered to obtain a solution with a viscosity of 80 mm. 2 The organopolysiloxane obtained was represented by the following average composition formula: (-C 3 H 6 -S 4 -C 3 H 6 -) 0.36 (-C 6 H 5 ) 0.07 (-C 8 H 17 ) 0.21 (-OC 2 H 5 ) 2.00 SiO 0.50

[0046] [Comparative Example 1-1] A 1 L separable flask equipped with a stirrer, reflux condenser, dropping funnel and thermometer was charged with 539 g (1.0 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, manufactured by Shin-Etsu Chemical Co., Ltd.), 222 g (0.8 mol) of octyltriethoxysilane (KBE-3083, manufactured by Shin-Etsu Chemical Co., Ltd.) and 200 g of ethanol, and then 25.2 g of 0.5 N hydrochloric acid (1.4 mol of water) was added dropwise at room temperature. The mixture was then stirred at 80°C for 10 hours. Thereafter, 3.0 g of propylene oxide was added dropwise and the mixture was stirred at 80°C for 2 hours. The mixture was then concentrated under reduced pressure and filtered to obtain a final product with a viscosity of 80 mm. 2 The organopolysiloxane obtained was represented by the following average composition formula: (-C 3 H 6 -S 4 -C 3 H 6 -) 0.36 (-C 8 H 17 ) 0.28 (-OC 2 H 5 ) 2.00 SiO 0.50

[0047] [2] Preparation of rubber composition [Examples 2-1 to 2-5, Comparative Examples 2-1 to 2-2] The SBR and BR shown in Table 1 were mixed for 30 seconds using a 4 L internal mixer (MIXTRON, manufactured by Kobe Steel, Ltd.). Next, the oil components, carbon black, silica, sulfide silane, organopolysiloxanes obtained in the Examples and Comparative Examples, stearic acid, antioxidants, and waxes shown in Table 1 were added, the internal temperature was raised to 150°C, and the mixture was held at 150°C for 2 minutes and then discharged. It was then stretched using rolls. The rubber obtained was again kneaded using an internal mixer (MIXTRON, manufactured by Kobe Steel, Ltd.) until the internal temperature reached 140°C, discharged, and then stretched using rolls. To this was added zinc oxide, a vulcanization accelerator, and sulfur as shown in Table 1, and the mixture was kneaded to obtain a rubber composition.

[0048] SBR: SLR-4602 (made by Trinseo) BR: BR-01 (JSR Corporation) Oil: AC-12 (Idemitsu Kosan Co., Ltd.) Carbon black: Seast 3 (manufactured by Tokai Carbon Co., Ltd.) Silica: Nipsil AQ (manufactured by Tosoh Silica Co., Ltd.) Sulfide silane: KBE-846 (Shin-Etsu Chemical Co., Ltd.) Stearic acid: Industrial stearic acid (Kao Corporation) Anti-aging agent: Nocrac 6C (Ouchi Shinko Chemical Industry Co., Ltd.) Wax: Ozoace 0355 (manufactured by Nippon Seiro Co., Ltd.) Zinc oxide: Zinc oxide No. 3 (manufactured by Mitsui Mining & Smelting Co., Ltd.) Vulcanization accelerator (a): Noccelaer D (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Vulcanization accelerator (b): Noccela DM-P (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Vulcanization accelerator (c): Noccela CZ-G (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Sulfur: 5% oil-treated sulfur (Hosoi Chemical Industry Co., Ltd.)

[0049] The unvulcanized and vulcanized physical properties of the rubber compositions obtained in Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-2 were measured by the following methods. The results are shown below. 1 to Regarding the vulcanized physical properties, the obtained rubber composition was press molded (160° C., 10 to 40 minutes) to prepare a vulcanized rubber sheet (thickness 2 mm).

[0050] [Unvulcanized physical properties] (1) Mooney Viscosity According to JIS K 6300-1:2013, the measurement was performed with 1 minute of preheating and 4 minutes of measurement at a temperature of 130°C, and expressed as an index with Comparative Example 2-1 being 100. The smaller the index value, the lower the Mooney viscosity and the better the processability. [Vulcanization properties] (2)Hardness The durometer (Type A) hardness was measured in accordance with JIS K 6253-3:2012 and expressed as an index with Comparative Example 2-1 taken as 100. The larger the index value, the higher and better the hardness. (3) Tensile properties A JIS No. 3 dumbbell-shaped test piece was punched out, and a tensile test was conducted at a tensile speed of 500 mm / min in accordance with JIS K6251. The 300% modulus (M 300 ) [MPa] was measured at room temperature. The obtained results were expressed as an index with Comparative Example 2-1 taken as 100. The larger the index value, the higher the modulus and the better the tensile properties. (4) Dynamic viscoelasticity (strain dispersion) Using a viscoelasticity measuring device (manufactured by Metravib), the storage modulus E’(0.5%) at a strain of 0.5% and the storage modulus E’(3.0%) at a strain of 3.0% were measured under the conditions of a temperature of 25°C and a frequency of 55 Hz, and the value of [E’(0.5%) - E’(3.0%)] was calculated. The test piece used was a sheet with a thickness of 0.2 cm and a width of 0.5 cm, and the initial load was 1 N with a distance between the used clamps of 2 cm. The value of [E’(0.5%) - E’(3.0%)] was expressed as an index with Comparative Example 2-1 taken as 100. The smaller the index value, the better the dispersibility of silica. (5) Dynamic viscoelasticity (temperature dispersion) Using a viscoelasticity measuring device (manufactured by Metravib), the measurement was conducted under the conditions of a dynamic tensile strain of 1% and a frequency of 55 Hz. The test piece used was a sheet with a thickness of 0.2 cm and a width of 0.5 cm, and the initial load was 1 N with a distance between the used clamps of 2 cm. The values of tanδ(0°C) and tanδ(60°C) were expressed as an index with Comparative Example 2-1 taken as 100. For the value of tanδ(0°C), the larger the index value, the better the wet grip performance. For the value of tanδ(60°C), the smaller the index value, the better the rolling resistance. (6) Abrasion resistance Using an FPS tester (manufactured by Ueshima Seisakusho), the test was conducted under the conditions of a sample speed of 200 m / min, a load of 20 N, a road surface temperature of 30°C, and a slip rate of 5%. The results obtained were expressed as an index, with Comparative Example 2-1 being set at 100. A larger index value indicates a smaller amount of wear and better wear resistance.

[0051] [Table 1]

[0052] As shown in Table 1, the vulcanizates of the rubber compositions of Examples 2-1 to 2-5 were 2-1 Compared to the vulcanizate of the rubber composition of the previous one, it has a smaller strain dispersion [E'(0.5%)-E'(3.0%)] value and excellent silica dispersibility while maintaining hardness and tensile properties. It also has a high dynamic viscoelasticity tan δ(0℃) value, excellent wet grip, a low dynamic viscoelasticity tan δ(60℃) value, small hysteresis loss, and low heat buildup.

Claims

1. A rubber composition comprising an organopolysiloxane represented by the following average composition formula (1), a diene rubber, and a filler: (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a sulfide group-containing alkylene group represented by the following average formula (2): 【Chemistry 1】 (In the formula, each n is independently a number from 1 to 10, x is a number from 2 to 6, and the dashed line represents a bond.) R 2 each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms; R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c, and d represent numbers that satisfy the following conditions: 0<2a<1, 0<b<1, 0<c<3, 0≦d<1, and 0<2a+b+c+d<4.)

2. 2. The rubber composition according to claim 1, wherein the x is a number from 2 to 4.

3. The R 2 3. The rubber composition according to claim 1, wherein represents a phenyl group.

4. The rubber composition according to any one of claims 1 to 3, wherein the d is a number satisfying 0<d<1.

5. The R 4 The rubber composition according to any one of claims 1 to 4, wherein represents an alkyl group having 6 to 12 carbon atoms.

6. A tire produced by molding the rubber composition according to any one of claims 1 to 5.

7. A cured product of the rubber composition according to any one of claims 1 to 5.

8. A tire using the cured product according to claim 7.

9. A tire formed from a rubber composition containing an organopolysiloxane represented by the following average composition formula (1): (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a sulfide group-containing alkylene group represented by the following average formula (2): 【Chemistry 2】 (In the formula, each n is independently a number from 1 to 10, x is a number from 2 to 6, and the dashed line represents a bond.) R 2 each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms; R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c, and d represent numbers that satisfy the following conditions: 0<2a<1, 0<b<1, 0<c<3, 0≦d<1, and 0<2a+b+c+d<4.)

10. A tire using a cured product of a rubber composition containing an organopolysiloxane represented by the following average composition formula (1): (R 1 ) a (R 2 ) b (OR 3 ) c (R 4 ) d SiO (4-2a-b-c-d) / 2 (1) (In the formula, R 1 each independently represents a sulfide group-containing alkylene group represented by the following average formula (2): 【Chemistry 3】 (In the formula, each n is independently a number from 1 to 10, x is a number from 2 to 6, and the dashed line represents a bond.) R 2 each independently represents an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms; R 3 each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; R 4 each independently represents an alkyl group having 1 to 12 carbon atoms, and a, b, c, and d represent numbers that satisfy the following conditions: 0<2a<1, 0<b<1, 0<c<3, 0≦d<1, and 0<2a+b+c+d<4.)

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