Compounding agent for diene rubber and rubber composition

Abstract

To provide a compounding agent for diene rubber which, when added to a rubber composition, gives a rubber composition capable of realizing desired hardness and tensile properties without deteriorating the processability, abrasion resistance, and fuel economy of the composition. [Solution] A compounding agent for diene rubber containing the following component (A): (A) a silanol group-containing organosilicon compound having a structure represented by the following formula (1): TIFF0007605366000038.tif2035(in the formula, R 1 each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and the wavy line represents the point of attachment.

Description

[Technical field]

[0001] The present invention relates to a compounding agent for diene rubber and a rubber composition. [Background technology]

[0002] Silica-filled tires have excellent performance in automotive applications, especially in terms of wear resistance, rolling resistance, and wet grip. These performance improvements are closely related to the improvement of fuel efficiency of tires, so silica-filled tires have been actively researched in the passenger tire industry, especially those using solution-polymerized styrene-butadiene rubber (S-SBR).

[0003] Although silica-filled rubber compositions reduce the rolling resistance of tires and improve wet grip performance, they have a high unvulcanized viscosity, require multi-stage kneading, and have problems with workability. Therefore, in rubber compositions in which inorganic fillers such as silica are simply blended, the filler is not sufficiently dispersed, resulting in problems such as a significant decrease in fracture strength and abrasion resistance. Therefore, in order to improve the dispersion of the inorganic filler in the rubber and to chemically bond the filler to the rubber matrix, a sulfur-containing organosilicon compound has been essential.

[0004] As sulfur-containing organosilicon compounds used as compounding agents for rubber, 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 (see Patent Documents 1 to 4).

[0005] Various alkoxysilyl group-containing compounds have been developed to improve the dispersibility of silica, an inorganic filler, and to improve fuel economy, but while they improve fuel economy, they have problems in that they do not improve hardness or tensile properties. Therefore, there is a demand for materials that improve hardness and tensile properties without deteriorating processability or fuel economy. [Prior art documents] [Patent documents]

[0006] [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] JP 2000-103795 A Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a compounding agent for diene-based rubber which, when added to a rubber composition, gives a rubber composition capable of realizing desired hardness and tensile properties without deteriorating the processability, abrasion resistance, or fuel economy of the composition; a rubber composition containing this compounding agent; and a tire formed from this rubber composition. [Means for solving the problem]

[0008] As a result of intensive research aimed at solving the above problems, the present inventors have found that a specific silanol group-containing organosilicon compound is suitable as a compounding agent for diene-based rubber, and that a tire obtained from a rubber composition containing said rubber compounding agent can achieve the desired hardness and tensile properties without deteriorating the processability, wear resistance, or fuel economy of the composition, thereby completing the present invention.

[0009] That is, the present invention provides 1. A compounding agent for diene rubber, comprising the following component (A): (A) A silanol group-containing organosilicon compound having a structure represented by the following formula (1): [ka] (In the formula, R 1each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and the wavy line represents the point of attachment. 2. The rubber compounding agent according to claim 1, wherein the component (A) contains a compound represented by the following formula (2): [ka] (In the formula, R 1 has the same meaning as above, and m is an integer of 1 to 100. 3. The compounding agent for rubber according to 1 or 2, wherein the component (A) contains a compound represented by the following formula (3): [ka] (In the formula, R 1 has the same meaning as above, X represents an n-valent structure, m is an integer of 1 to 100, and n is an integer of 2 to 8. 4. The rubber compounding agent according to 3, wherein X is a structure represented by the following formula (4), (5) or (6): [ka] (In the formula, R 1 has the same meaning as above, y is an integer of 1 to 20, and the wavy line represents the bonding site. 5. The above R 1 each independently represents a methyl group or a phenyl group; 6. (A) A silanol group-containing organosilicon compound having a structure represented by the following formula (1): [ka] (In the formula, R 1 each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and the wavy line represents a bonding point. (B) a diene rubber, and (C) Inorganic filler A rubber composition comprising: 7. The rubber composition according to 6, wherein the component (A) contains a compound represented by the following formula (2): [ka] (In the formula, R 1 has the same meaning as above, and m is an integer of 1 to 100. 8. The rubber composition according to 6 or 7, wherein the component (A) contains a compound represented by the following formula (3): [ka] (In the formula, R 1 has the same meaning as above, X represents an n-valent structure, m is an integer of 1 to 100, and n is an integer of 2 to 8. 9. The rubber composition according to claim 8, wherein X is a structure represented by the following formula (4), (5) or (6): [ka] (In the formula, R 1 has the same meaning as above, y is an integer of 1 to 20, and the wavy line represents the bonding site. 10. The above R 1 each independently represents a methyl group or a phenyl group; 11. The rubber composition according to any one of 6 to 10, wherein the (C) inorganic filler contains silica. 12. Any of the rubber compositions according to 6 to 10, comprising (D) an organosilicon compound having one or more groups selected from a polysulfide group, a thioester group, and a mercapto group, and an alkoxysilyl group; 13. A tire formed from the rubber composition according to any one of 6 to 12. to provide. Effect of the Invention

[0010] The rubber composition containing the rubber compounding agent of the present invention has excellent processability, and a tire formed using this rubber composition can achieve the desired hardness and tensile properties without deteriorating the wear resistance and fuel economy performance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be specifically described below. [Rubber compounding agents] The compounding agent for rubber of the present invention contains the following component (A). [1] (A) Silanol group-containing organosilicon compound Component (A) is a silanol group-containing organosilicon compound having a structure represented by the following formula (1): In formula (1), the wavy lines represent bonding sites. The content of hydroxyl groups derived from silanol structures in the component (A) is preferably 0.5 to 30.0 mass %, more preferably 0.6 to 20 mass %, and even more preferably 0.8 to 18 mass %, relative to the mass of the component (A).

[0012] [ka]

[0013] In formula (1), R 1 each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group. The alkyl group may be linear, branched, or cyclic. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, i-butyl, tert-butyl, neopentyl, n-hexyl, cyclohexyl, n-heptyl, and n-octyl groups. An alkyl group having 1 to 3 carbon atoms is preferred, and a methyl group is more preferred. The aralkyl group is preferably an aralkyl group having 7 to 20 carbon atoms, and specific examples thereof include a benzyl group and a phenylethyl group. The aryl group is preferably an aryl group having 6 to 18 carbon atoms, and specific examples thereof include unsubstituted aryl groups such as phenyl and naphthyl groups; and alkylaryl groups having 7 to 18 carbon atoms such as tolyl, xylyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, and dodecylphenyl groups, with the phenyl group being preferred.

[0014] The component (A) preferably contains a compound represented by the following formula (2) and / or a compound represented by the following formula (3).

[0015] [ka]

[0016] In formulas (2) and (3), R 1 has the same meaning as in the above formula (1), and is preferably a methyl group or a phenyl group. m is an integer of 1 to 100, and an integer of 1 to 60 is preferable. n is an integer of 2 to 8, and an integer of 2 to 4 is preferable.

[0017] In addition, in formulas (2) and (3), -R 1 -Si-R 1 When there are two or more -'s (m is 2 or more), they may be the same or different, and may be, for example, a compound represented by the following formula (2') and / or (3').

[0018] [ka] (In formula (2), R 1 has the same meaning as above, but for all R 1 are not the same group at the same time, and in formula (3), R 1 has the same meaning as above, but for all R 1 are not the same group at the same time, and in each formula, m1 and m2 are each an integer of 1 or more, and m1+m2 is an integer of 2 to 100.)

[0019] X represents an n-valent structure, and examples thereof include linear, branched, or cyclic structures containing a hydrocarbon skeleton or a siloxane skeleton, and structures represented by the following formula (4), (5), or (6) are preferred.

[0020] [ka] (In the formula, R 1 has the same meaning as above, and the wavy line indicates the bond site.)

[0021] In formula (4), y is an integer of 1 to 20, preferably an integer of 1 to 10, and more preferably an integer of 1 to 5.

[0022] Specific examples of the silanol group-containing organosilicon compound of component (A) include, but are not limited to, those represented by the following formula: In the formula, Me represents a methyl group (the same applies hereinafter).

[0023] [ka] (In the formula, m, m1, and m2 have the same meanings as above.)

[0024] The component (A) may use one type alone, or two or more types in combination.

[0025] The composition containing the silanol group-containing organosilicon compound (A) of the present invention described above can be used as a compounding agent for rubber by itself, but the composition may also be mixed with at least one type of powder and used as a compounding agent for rubber. Specific examples of the powder include carbon black, talc, calcium carbonate, stearic acid, silica, aluminum hydroxide, alumina, and magnesium hydroxide. Among these, silica and aluminum hydroxide are preferred from the viewpoint of reinforcing properties, and silica is more preferred.

[0026] The rubber compounding agent of the present invention may be a mixture with an organic polymer or rubber, such as a fatty acid, a fatty acid salt, polyethylene, polypropylene, polyoxyalkylene, polyester, polyurethane, polystyrene, polybutadiene, polyisoprene, natural rubber, or a styrene-butadiene copolymer, or may be a mixture with various additives that are commonly used for tires or other general rubbers, such as a vulcanizing agent, a crosslinking agent, a vulcanization accelerator, a crosslinking accelerator, various oils, an antioxidant, a filler, or a plasticizer. The form of the agent may be liquid or solid, and may be diluted in an organic solvent or may be emulsified.

[0027] [Rubber composition] The rubber composition of the present invention contains the above-mentioned component (A), diene rubber (B), and inorganic filler (C). The amount of component (A) in the rubber composition of the present invention is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of component (B), which will be described in detail later, taking into consideration the physical properties of the resulting rubber and the balance between the degree of effect exerted and economic efficiency.

[0028] [2] (B) Diene rubber The diene rubber of component (B) may be any rubber that has been generally used in various rubber compositions in the past. Specific examples include diene rubbers such as various isoprene rubbers (IR) such as natural rubber, various styrene-butadiene copolymer rubbers (SBR), various polybutadiene rubbers (BR), and acrylonitrile-butadiene copolymer rubbers (NBR). These may be used alone or in combination of two or more. In addition to the diene rubber, non-diene rubbers such as butyl rubber (IIR) and ethylene-propylene copolymer rubber (EPR, EPDM) may be used in combination.

[0029] [3] (C) Inorganic filler Examples of the inorganic filler of component (C) include those commonly used in the tire industry, such as silica, carbon black, aluminum hydroxide, alumina (aluminum oxide), calcium carbonate, talc, and clay. These may be used alone or in combination of two or more. Of these, the rubber composition of the present invention preferably contains silica and carbon black.

[0030] Examples of carbon black include those commonly used in the tire industry, such as GPF, FEF, HAF, ISAF, and SAF. Examples of silica include silica prepared by a dry method (anhydrous silica) and silica prepared by a wet method (hydrated silica), which are commonly used in the tire industry. Among these, silica prepared by a wet method is preferred because it contains a large number of silanol groups. In particular, silica has a nitrogen adsorption specific surface area (N2SA) of 70m 2 / g or more is preferable, and 100m 2 The upper limit of N2SA is not particularly limited, but from the viewpoint of ease of handling, it is preferably 500 m 2 / g or less is preferable, and 400m 2 / g or less is more preferable.

[0031] The amount of component (C) in the rubber composition of the present invention is preferably 5 to 200 parts by mass, more preferably 10 to 150 parts by mass, and even more preferably 20 to 130 parts by mass, per 100 parts by mass of component (B), from the viewpoints of dispersibility, fuel economy, molding processability, and the like.

[0032] [4] (D) Silane coupling agent In addition to the above components, the rubber compounding agent of the present invention can use (D) a silane coupling agent having at least one selected from a polysulfide group, a thioester group, and a mercapto group, and an alkoxysilyl group. The component (D) is not particularly limited as long as it is a compound having such a functional group, and for example, any conventionally known silane coupling agent that is compounded in a rubber composition for use in tires and the like can be used.

[0033] Specific examples of the silane coupling agent include polysulfide-based organosilicon compounds such as bis-(3-bistriethoxysilylpropyl)-tetrasulfide and bis-(3-bistriethoxysilylpropyl)-disulfide; mercapto-based organosilicon compounds such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane; and thioester-based organosilicon compounds such as 3-octanoylthiopropyltriethoxysilane and 3-propionylthiopropyltrimethoxysilane. Also usable are reaction products of the above-mentioned organosilicon compounds having sulfur atoms with alcohols containing polyether groups, hydrolysis condensation products of these organosilicon compounds, and co-hydrolysis condensation products of these organosilicon compounds with other organosilicon compounds having alkoxysilyl groups. The component (D) may be used alone or in combination of two or more types.

[0034] When the rubber composition of the present invention contains the component (D), the blending amount thereof is preferably 1 to 30 parts by mass, and more preferably 2 to 20 parts by mass, per 100 parts by mass of the component (B).

[0035] In addition to the above components (A) to (D), the rubber composition of the present invention may contain various additives that are generally used in tires and other rubbers, such as sulfur, crosslinking agents, vulcanization accelerators, crosslinking accelerators, various oils, antioxidants, plasticizers, various resins, wax, zinc oxide, etc. The amounts of these additives may be conventional amounts, as long as they do not deviate from the object of the present invention.

[0036] Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are generally used in the rubber industry. These may be used alone or in combination of two or more. As these sulfurs, products available from, for example, Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemical Industry Co., Ltd., Flexis Corporation, Nippon Kanzuri Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. may be used.

[0037] When sulfur is added, the amount of sulfur added is preferably 0.1 to 5.0 parts by mass, more preferably 0.3 to 3.0 parts by mass, and even more preferably 0.5 to 2.0 parts by mass, per 100 parts by mass of component (B). Within the above range, a good balance between tensile properties and abrasion resistance is achieved.

[0038] [Rubber products (tires)] The rubber composition of the present invention described above can be used for producing rubber products such as tires by preparing a composition from the above-mentioned components (A) to (C) and the optional component (D) and other components in a general manner, 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. A tire obtained by using the rubber composition of the present invention has reduced rolling resistance and improved wear 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 filled in the tire may be air or air with an adjusted oxygen partial pressure, or an inert gas such as nitrogen, argon, or helium. EXAMPLES

[0039] The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0040] [Examples 1-1 to 1-9, Comparative Example 1-1] The natural rubber shown in Table 1 was kneaded for 60 seconds using a 4 L internal mixer (MIXTRON, manufactured by Kobe Steel, Ltd.). Next, carbon black, silica, silanol-containing compound, stearic acid, antioxidant, resin, and wax shown in Table 1 were added, the internal temperature was raised to 150°C, and the mixture was discharged. Thereafter, the mixture was stretched using rolls. The obtained rubber composition was again kneaded using an internal mixer (MIXTRON, manufactured by Kobe Steel, Ltd.) until the internal temperature reached 145°C, discharged, and then stretched using rolls. Zinc oxide, vulcanization accelerator, and sulfur shown in Table 1 were added thereto and kneaded to obtain a rubber composition.

[0041] Natural rubber: RSS#3 Carbon black: Seast 9H (manufactured by Tokai Carbon Co., Ltd.) Silica: Nipsil AQ (manufactured by Tosoh Silica Co., Ltd.) Sulfide silane: KBE-846 (Shin-Etsu Chemical Co., Ltd., bis(triethoxysilylpropyl)tetrasulfide)

[0042] (A-1): Compound represented by the following formula (hydroxyl group content: 10.0% by mass) [ka]

[0043] (A-2): Compound represented by the following formula (hydroxyl group content: 2.2% by mass) [ka]

[0044] (A-3): Compound represented by the following formula (hydroxyl group content: 1.1% by mass) [ka]

[0045] (A-4): Compound represented by the following formula (hydroxyl group content: 0.8% by mass) [ka]

[0046] (A-5): Compound represented by the following formula (hydroxyl group content: 5.9% by mass) [ka]

[0047] (A-6): Compound represented by the following formula (hydroxyl group content: 15.7% by mass) [ka]

[0048] (A-7): Compound represented by the following formula (hydroxyl group content: 4.4% by mass) [ka]

[0049] Stearic acid: Industrial stearic acid (Kao Corporation) Anti-aging agent: Nocrac 6C (Ouchi Shinko Chemical Industry Co., Ltd.) Resin: T-REZ RA-100 (manufactured by ENEOS Corporation) 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): Noccela DM-P (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Vulcanization accelerator (b): Noccela CZ-G (manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) Sulfur: 5% oil-treated sulfur (Hosoi Chemical Industry Co., Ltd.)

[0050] The unvulcanized and vulcanized physical properties of the rubber compositions obtained in Examples 1-1 to 1-9 and Comparative Example 1-1 were measured by the following methods. The results are also shown in Table 1. Regarding the vulcanized physical properties, the obtained rubber compositions were press molded (145°C, 30 minutes) to produce vulcanized rubber sheets (thickness 2 mm).

[0051] The compositions and vulcanized rubber sheets obtained in the above Examples and Comparative Examples were measured for the following physical properties. The results are also shown in Table 1. [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 1-1 being 100. The smaller the index value, the lower the Mooney viscosity and the better the processability. [Vulcanization properties] (2)Hardness Durometer (type A) hardness was measured in accordance with JIS K 6253-3:2012, and expressed as an index with Comparative Example 1-1 being 100. The larger the index value, the higher and more excellent the hardness. (3) Tensile properties A JIS No. 3 dumbbell-shaped test piece was punched out and a tensile test was performed 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 results were expressed as an index, with Comparative Example 1-1 being set at 100. A larger index value indicates a higher modulus and more excellent tensile properties. (4) Dynamic viscoelasticity (temperature dispersion) A viscoelasticity measuring device (manufactured by Metravib) was used to measure under conditions of a tensile dynamic strain of 1% and a frequency of 55 Hz. The test piece was a sheet having a thickness of 0.2 cm and a width of 0.5 cm, the clamp distance was 2 cm, and the initial load was 1 N. The value of tan δ (60°C) was expressed as an index, with Comparative Example 1-1 being 100. The smaller the index value of tan δ (60°C), the better the rolling resistance. (5) Abrasion resistance Using an FPS tester (manufactured by Ueshima Seisakusho Co., Ltd.), the test was carried out 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% and a slip rate of 20%. The results obtained were expressed as an index, with Comparative Example 1-1 being 100. A larger index value indicates less wear and better wear resistance.

[0052] [Table 1]

[0053] As shown in Table 1, the vulcanizates of the rubber compositions obtained in Examples 1-1 to 1-9 have significantly improved hardness and tensile properties while maintaining abrasion resistance, compared to the vulcanizate of the rubber composition of Comparative Example 1-1.

[0054] [Examples 2-1 to 2-7, Comparative Example 2-1] The SBR and BR shown in Table 2 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, silanol compound, stearic acid, antioxidant, and wax shown in Table 2 were added, the internal temperature was raised to 150°C, and the mixture was held at 150°C for 2 minutes, after which it was discharged. It was then stretched using rolls. The obtained rubber 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 2, and the mixture was kneaded to obtain a rubber composition.

[0055] 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., bis(triethoxysilylpropyl)tetrasulfide)

[0056] (A-1): Compound represented by the following formula (hydroxyl group content: 10.0% by mass) [ka]

[0057] (A-2): Compound represented by the following formula (hydroxyl group content: 2.2% by mass) [ka]

[0058] (A-3): Compound represented by the following formula (hydroxyl group content: 1.1% by mass) [ka]

[0059] (A-4): Compound represented by the following formula (hydroxyl group content: 0.8% by mass) [ka]

[0060] (A-5): Compound represented by the following formula (hydroxyl group content: 5.9% by mass) [ka]

[0061] (A-6): Compound represented by the following formula (hydroxyl group content: 15.7% by mass) [ka]

[0062] (A-7): Compound represented by the following formula (hydroxyl group content: 4.4% by mass) [ka]

[0063] 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.)

[0064] The unvulcanized and vulcanized physical properties of the rubber compositions obtained in Examples 2-1 to 2-7 and Comparative Example 2-1 were measured by the following methods. The results are also shown in Table 2. Regarding the vulcanized physical properties, the obtained rubber compositions were press molded (160°C, 10 to 40 minutes) to produce vulcanized rubber sheets (thickness 2 mm).

[0065] [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. (2) Vulcanization characteristics (T90) The vulcanization rate at 160°C was measured using a rotorless rheometer, and the minimum torque ML and maximum torque MH were obtained from the vulcanization curve, and T90 (the time (min) required to reach 90% of the maximum torque) was calculated. Comparative Example 2-1 was set at 100 and expressed as an index. The smaller the index value, the faster the vulcanization rate and the better the productivity. [Vulcanization properties] (3)Hardness Durometer (type A) hardness was measured in accordance with JIS K 6253-3:2012, and expressed as an index with Comparative Example 2-1 being 100. The larger the index value, the higher and more excellent the hardness. (4) Tensile properties A JIS No. 3 dumbbell-shaped test piece was punched out and a tensile test was performed 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 results were expressed as an index, with Comparative Example 2-1 being set at 100. A larger index value indicates a higher modulus and more excellent tensile properties. (5) Dynamic viscoelasticity (temperature dispersion) A viscoelasticity measuring device (Metravib) was used to measure under conditions of a tensile dynamic strain of 1% and a frequency of 55 Hz. The test specimen was a sheet with a thickness of 0.2 cm and a width of 0.5 cm, with a clamp distance of 2 cm and an initial load of 1 N. The values ​​of tan δ(0°C) and tan δ(60°C) are expressed as indexes with the value of Comparative Example 2-1 being 100. The larger the index value of tan δ(0°C), the better the wet grip performance. The smaller the index value of tan δ(60°C), the better the rolling resistance. (6) Abrasion resistance Using an FPS tester (manufactured by Ueshima Seisakusho Co., Ltd.), the test was carried out under the conditions of a sample speed of 200 m / min, a load of 20 N, a road surface temperature of 30°C, and slip rates of 5% and 20%. The results were expressed as an index, with Comparative Example 2-1 being 100. A higher index value indicates less wear and better wear resistance.

[0066] [Table 2]

[0067] As shown in Table 2, the vulcanizates of the rubber compositions of Examples 2-1 to 2-7 have significantly improved hardness and tensile properties while maintaining abrasion resistance, compared to the vulcanizate of the rubber composition of Comparative Example 2-1.

Claims

1. The following component (A): (A) A silanol group-containing organosilicon compound having a structure represented by the following formula (1): 【Chemistry 1】 (In the formula, R 1 each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and the wavy line represents the point of attachment. A compounding agent for diene rubber comprising: The compounding agent for diene rubber, wherein the component (A) comprises a silanol group-containing organosilicon compound represented by the following formula (3): 【Chemistry 2】 [In the formula, R 1 represents the same meaning as above, and X represents an n-valent structure and is a structure represented by the following formula (4), (5) or (6): 【Chemistry 3】 (In the formula, R 1 has the same meaning as above, y is an integer of 1 to 20, and the wavy line represents the bonding site. m is an integer from 1 to 100, and n is an integer of 2 or 4.

2. The R 1 2. The rubber compounding agent according to claim 1, wherein each of the groups independently represents a methyl group or a phenyl group.

3. (A) A silanol group-containing organosilicon compound having a structure represented by the following formula (1): 【Chemistry 4】 (In the formula, R 1 each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and the wavy line represents a bonding point. (B) a diene rubber, and (C) Inorganic filler A rubber composition comprising: The rubber composition, wherein the component (A) contains a compound represented by the following formula (3): 【Chemistry 5】 [In the formula, R 1 represents the same meaning as above, and X represents an n-valent structure and is a structure represented by the following formula (4), (5) or (6): 【Chemistry 6】 (In the formula, R 1 has the same meaning as above, y is an integer of 1 to 20, and the wavy line represents the bonding site. m is an integer from 1 to 100, and n is an integer of 2 or 4.

4. The R 1 4. The rubber composition according to claim 3, wherein each of the is independently a methyl group or a phenyl group.

5. The rubber composition according to claim 3 , wherein the inorganic filler (C) contains silica.

6. 4. The rubber composition according to claim 3, further comprising (D) an organosilicon compound having an alkoxysilyl group and at least one group selected from the group consisting of a polysulfide group, a thioester group and a mercapto group.

7. A tire produced by molding the rubber composition according to claim 3.

8. (A) A silanol group-containing organosilicon compound having a structure represented by the following formula (1): 【Chemistry 7】 (In the formula, R 1 each independently represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group, and the wavy line represents a bonding point. (B) a diene rubber, and (C) Inorganic filler A rubber composition comprising: The component (A) is a rubber composition (excluding latex compositions) containing a compound represented by the following formula (2): 【Chemistry 8】 (In the formula, R 1 has the same meaning as above, and m is an integer of 1 to 100.

9. The R 1 The rubber composition according to claim 8, wherein each of the is independently a methyl group or a phenyl group.

10. The rubber composition according to claim 8, wherein the inorganic filler (C) contains silica.

11. 9. The rubber composition according to claim 8, further comprising (D) an organosilicon compound having an alkoxysilyl group and at least one group selected from the group consisting of a polysulfide group, a thioester group and a mercapto group.

12. A tire formed by molding the rubber composition according to claim 8.

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