Rubber composition for tires and tires

Abstract

Rubber composition for tires, the rubber composition comprising: 100 parts by mass of a diene rubber containing a styrene-butadiene copolymer rubber having a styrene content of 30% by mass or more; 50 to 200 parts by mass of carbon black having a nitrogen adsorption surface area N2SA of 100 to 500 m2 / g and N2SA / IA, which is a ratio of the nitrogen adsorption surface area N2SA (unit: m2 / g) to an iodine adsorption number IA (unit: mg / g), of 0.90 to 1.03; 5 to 50 parts by mass of a styrolated phenol compound represented by the structural formula (1); and 20 to 90 parts by mass of a sticky resin; wherein a mixed quantity of the styrofoamed phenol compound represents 15% by mass or more based on a quantity of the sticky resin: wherein n is 2 or 3;wherein the sticky resin is one or more types selected from the group consisting of a C9 petroleum resin, a phenolic resin, a coumaron indene resin, a terpene resin, a styrene resin, an acrylic resin, a rosin resin and a dicyclopentadiene resin.

Description

Technical field

[0001] The present invention relates to a rubber composition for tires and a tire. State of the art

[0002] In general, various performance characteristics are required of racing tires. In particular, racing tires must exhibit excellent steering stability (dry grip) on a dry road surface at high speeds and also suppress changes in their performance, such as heat-induced loss of grip during prolonged high-speed driving on a track. Therefore, to improve dry grip, for example, carbon black (which has a high specific surface area), a sticky resin, and a plasticizer were blended in large quantities. However, the aforementioned methods degrade the grain performance (abrasion resistance and grip performance at low temperatures), and the temperature dependence of the hardness comes into play, resulting in a heat-related loss of grip performance, which leads to poor results in races.

[0003] Patent document 1 below describes a rubber composition for a tire tread, comprising: (A) 100 parts by mass of a diene rubber, comprising an aromatic vinyl-conjugated diene rubber having a glass transition temperature (Tg) of -35 °C or higher, and (B) 50 to 200 parts by mass of a carbon black having a nitrogen adsorption specific surface area (N2SA) of 100 to 400 m². 2 / g and a DBP absorption of 100 to 200 cm 3 / 100 g; and comprising 0.5 to 20 parts by mass (C) of a styrolated phenol compound containing distyrolated phenol or tristyrolated phenol as the main component. However, the technology described in patent document 1 cannot satisfy the dry grip performance, the graining performance and the heat-related loss of grip performance in a compatible manner.

[0004] On the other hand, a tire for driving on a dry road surface and a tire for driving on a wet road surface are prepared as racing pneumatic tires, and an optimal tire for each of these is selected according to the weather and road surface conditions at the time of driving. For racing tires for driving on wet road surfaces, several methods have been employed to improve wet grip performance, such as (1) blending with silica, which has a high specific surface area, (2) blending with a large quantity of silica, and (3) blending with a large quantity of a resin. However, the aforementioned methods (1) and (2) exhibited a problem with poor abrasion resistance due to the poor dispersibility of silica, and the aforementioned method (3) had a problem with poor warm-up performance (wet grip performance at low temperatures).

[0005] As an attempt to improve wet grip performance, for example, patent document 2 below describes a rubber composition in which silica, which has a high specific surface area, and a resin component, which has a high Tg, and a resin component, which has a low Tg, are mixed with a diene rubber. However, it is difficult for technology to improve both wet grip performance and abrasion resistance. List of literature on patent literature Patent Document 1: JP 2016-113482 A Patent Document 2: JP 2007-186567 A Brief description of the invention: Technical problem

[0006] An object of the present invention is to provide a rubber composition for tires, wherein the composition is able to improve dry grip performance and graining performance and is able to improve a heat-induced loss of grip performance by suppressing the temperature dependence of the hardness, and to provide a tire using the rubber composition.

[0007] A further object of the present invention is to provide a rubber composition for tires, wherein the composition is able to provide excellent steering stability, improve wet grip performance, in particular warm-up performance (wet grip performance at low temperatures), improve fracture toughness and provide excellent abrasion resistance, and to provide a tire using the rubber composition. Solution to the problem

[0008] One embodiment of the present invention provides a rubber composition for tires, comprising: 100 parts by mass of a diene rubber containing a styrene-butadiene copolymer rubber having a styrene content of 30% by mass or more, and 50 to 200 parts by mass of carbon black having a nitrogen adsorption surface area (N2SA) of 100 to 500 m². 2 / g and N2SA / IA, which is a ratio of the nitrogen adsorption specific surface area N2SA (unit: m²) 2 / g) to an iodine adsorption number IA (unit: mg / g), of 0.90 to 1.03; to 5 to 50 parts by mass a styrolated phenol compound represented by the structural formula (1) below; and to 20 parts by mass or more a sticky resin; wherein a mixed amount of the styrolated phenol compound is 15 wt% or more based on an amount of the sticky resin.

[0009] Another embodiment of the present invention provides a rubber composition for tires, comprising: 100 parts by mass of a diene rubber containing a styrene-butadiene copolymer rubber having a styrene content of 30% by mass or more, and 150 to 300 parts by mass of silica having a nitrogen adsorption-specific surface area N2SA of 100 to 300 m². 2 / g; comprising 5 to 50 parts by mass of a styrofoam phenol compound represented by the structural formula (1) below; and comprising 20 parts by mass or more of a sticky resin; wherein a mixed amount of the styrofoam phenol compound is 15% by mass or more based on an amount of the sticky resin.

[0010] In the structural formula (1) n is 2 or 3. Advantageous effects of the invention

[0011] The rubber composition for tires according to one embodiment of the present invention contains a specific amount of carbon black, which has a specific property in a diene rubber having a specific composition, and further contains a specific amount of a styrenated phenolic compound, and thus the rubber composition for tires can be provided, wherein the composition is able to improve dry grip performance and graining performance, and is able to improve a heat-induced loss of grip performance by suppressing the temperature dependence of the hardness; and likewise a tire can be provided using the rubber composition.

[0012] The rubber composition for tires according to one embodiment of the present invention contains a specific amount of silica, which has a specific property in a diene rubber having a specific composition, and further contains a specific amount of a styrenated phenolic compound, and thus the rubber composition for tires can be provided, wherein the composition is able to provide excellent steering stability, improve wet grip performance, in particular warm-up performance (wet grip performance at low temperatures), improve fracture toughness and provide excellent abrasion resistance; and likewise a tire can be provided using the rubber composition. Description of embodiments

[0013] The present invention is described in more detail below. Dien rubber

[0014] The diene rubber used in one embodiment of the present invention contains a styrene-butadiene copolymer rubber (SBR) as a key component. If the total quantity of the diene rubber used in one embodiment of the present invention is assumed to be 100 parts by mass, the proportion of SBR can be determined by appropriately considering various conditions, such as air temperature and weather, for example, in a racing application. For example, the proportion of SBR can be 70 parts by mass or more, preferably 85 parts by mass or more, and more preferably 100 parts by mass.In addition to SBR, any diene rubber that can be blended into ordinary rubber compositions can be used in an embodiment of the present invention, and examples include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), acrylonitrile butadiene copolymer rubber (NBR), and ethylene propylene diene terpolymer (EPDM). These can each be used individually, or two or more types can be used in combination. Furthermore, their molecular weight and microstructure are not particularly restricted. The diene rubber can be terminally modified or epoxidized with an amine, amide, silyl, alkoxysilyl, carboxyl, or hydroxyl group.

[0015] The SBR used in one embodiment of the present invention preferably has a styrene content of 30% by mass or more. Achieving such a styrene content increases the glass transition temperature (Tg) of the SBR, and the dry grip performance can be improved. Furthermore, the wet grip performance, steering stability, and abrasion resistance of a tire can be enhanced. Preferably, the styrene content is 33 to 50% by mass. soot

[0016] The carbon black used in one embodiment of the present invention has a nitrogen adsorption-specific surface area N2SA of 100 to 500 m². 2 / g and N2SA / IA, which is a ratio of the nitrogen adsorption specific surface area N2SA (unit: m²) 2 / g) to an iodine adsorption number IA (unit: mg / g), from 0.90 to 1.03 (hereinafter also referred to as specific carbon black). It can be said that the carbon black fulfilling this N2SA / IA has a large number of functional groups present on the surface and exhibits high surface activity. The carbon black exhibiting high surface activity interacts strongly with an OH group contained in the styrenic phenol compound described below, can improve dry grip performance and graining performance, and can improve the heat-induced loss of grip performance by suppressing the temperature dependence of hardness.

[0017] In the specific carbon black used in one embodiment of the present invention, the N2SA is preferably 150 to 400 m from the perspective of further improving the interaction effects. 2 / g, and the N2SA / IA is preferably from 0.92 to 1.01 and more preferably from 0.93 to 1.00. The IA is preferably from 130 to 500 mg / g and more preferably from 150 to 470 mg / g. It should be noted that N2SA is measured according to JIS K 6217-2 and IA is measured according to JIS K 6217-1. Silica

[0018] The silica used in one embodiment of the present invention has a nitrogen adsorption-specific surface area N2SA of 100 to 300 m². 2 / g on (hereinafter also referred to as specific silica). If the N2SA of the silica is less than 100 m 2 When the weight is / g, the hardness and breaking strength decrease, thus impairing steering stability and abrasion resistance. Furthermore, if the N2SA of silica exceeds 300 m 2 If the viscosity is too high (in grams per gram), processing becomes difficult. More preferably, the N2SA of the silica used in one embodiment of the present invention is from 130 to 270 m 2 / G. It should be noted that N2SA is measured according to JIS K 6217-2. Styrenoidal phenol compound

[0019] The styrenoidal phenol compound used in one embodiment of the present invention can be represented by the structural formula (1) below. The styrenoidal phenol compound used in one embodiment of the present invention increases tan δ by interacting with the diene rubber and has the function of improving dry grip performance. Furthermore, the styrenoidal phenol compound used in one embodiment of the present invention has functions to improve steering stability, wet grip performance, warm-up performance and abrasion resistance through the interaction of the diene rubber and the silica.

[0020] In the styrenoidal phenol compound represented by structural formula (1), n ​​is 2 or 3. That is, the styrenoidal phenol compound used in one embodiment of the present invention is a distyrenoidal phenol in which n is 2 or a tristyrenoidal phenol in which n is 3. In one embodiment of the present invention, a mixture of a distyrenoidal phenol compound and a tristyrenoidal phenol compound may also be used. It should be noted that in the styrenoidal phenol compound, if the number of styrene units in a molecule is small, the interaction with the diene monomer is reduced and the desired effects are less likely to be achieved. From this perspective, in one embodiment of the present invention, a monostyrenoidal phenol compound in which n is 1 is preferably not used. It should be noted that a trace amount of a monostyrenoidal phenol compound may be present (e.g.,0.1% by mass or less, based on the total amount of styrenoidal phenol compound to be used). The styrenated phenol compound represented by structural formula (1) can be prepared by a known manufacturing process and is also commercially available. Examples of commercially available products include SP-24 (containing distyrenated phenol as the main component) and TSP (containing tristyrenated phenol as the main component), available from Sanko Co., Ltd.

[0021] It should be noted that the styrene unit in the above formula can be a derivative of styrene. Examples include α-methylstyrene, o-methylstyrene, and 1,3-dimethylstyrene. Sticky resin

[0022] The tackifying resin used in one embodiment of the present invention is not subject to any special restrictions. Specific examples of the sticky resin include a phenolic resin (e.g., a phenolic resin, a phenol-acetylene resin, a phenol-formaldehyde resin), a coumaron-based resin (e.g., a coumaron resin, a coumaron-indene resin, a coumaron-indene-styrene resin), a terpene resin (e.g., a terpene resin, a modified terpene resin (e.g., an aromatic modified terpene resin), a terpene-phenol resin), a styrene resin, an acrylic resin, a rosin resin (e.g., a rosin, a rosin ester, a hardened derivative of rosin, a hydrogenated terpene resin), a petroleum resin (e.g., a C5 petroleum resin such as a dicyclopentadiene resin, a C9 petroleum resin, an alicyclic petroleum resin, a C5 / C9 copolymer-based petroleum resin), a xylene-based resin (e.g.a xylene resin, a xylene-acetylene resin, a xylene-formaldehyde resin, an α-pinene resin, and a saturated aliphatic hydrocarbon resin. From the perspective of achieving superior effects of the present invention and the like, the tackifying resin is preferably one or more types selected from the group consisting of a C9 petroleum resin, a phenolic resin, a coumaron-indene resin, a terpene resin, a styrene resin, an acrylic resin, a rosin resin, and a dicyclopentadiene resin.

[0023] From the perspective of achieving a superior effect of the present invention, the softening point of the tackifying resin is preferably 60 to 180 °C. It should be noted that the softening point is measured according to JIS K 6220-1. Mixing ratio of the rubber composition

[0024] In a first embodiment, the rubber composition according to an embodiment of the present invention contains 100 parts by mass of diene rubber, 50 to 200 parts by mass of a specific carbon black, 5 to 50 parts by mass of a styrenoidal phenol compound represented by structural formula (1), and 20 parts by mass or more of a sticky resin, and a mixed amount of the styrenoidal phenol compound is 15% by mass or more, based on an amount of the sticky resin. If the amount of specific carbon black mixed is less than 50 parts by mass, tan δ at 60 °C decreases. Conversely, the tensile strength decreases if the amount mixed is more than 200 parts by mass. A mixture of less than 5 parts by mass of the styrenoidal phenol compound does not achieve the effect of the present invention, as the mixture is too small. Conversely, if the mixture exceeds 50 parts by mass, the embrittlement temperature is higher. If the amount of the sticky resin mixed is less than 20 parts by mass, tan δ decreases at 60 °C. If the mixed amount of the styrenoidal phenol compound is less than 15% by mass, based on the amount of the sticky resin, the particle size distribution and the temperature dependence of the hardness deteriorate.

[0025] In the first embodiment of the rubber composition according to an embodiment of the present invention, the amount of carbon black mixed is preferably 70 to 190 parts by mass and more preferably 90 to 180 parts by mass, based on 100 parts by mass of the diene rubber. The amount of the styrenoidal phenol compound mixed is preferably from 7 to 45 parts by mass and more preferably from 10 to 40 parts by mass, based on 100 parts by mass of the diene rubber. The amount of the tackifying resin mixed is preferably from 25 to 90 parts by mass and more preferably from 30 to 80 parts by mass, based on 100 parts by mass of the diene rubber. The amount of the styrenoidal phenol compound mixed is preferably 20 to 80% by mass, based on the amount of the sticky resin.

[0026] In a second embodiment, the rubber composition according to an embodiment of the present invention contains 100 parts by mass of diene rubber, 150 to 300 parts by mass of a specific carbon black, 5 to 50 parts by mass of a styrenoidal phenol compound represented by structural formula (1), and 20 parts by mass or more of a sticky resin, and a mixed amount of the styrenoidal phenol compound is 15% by mass or more, based on an amount of the sticky resin. If the amount of specific silica in the mixture is less than 150 parts by mass, the hardness decreases and the steering stability deteriorates. Conversely, the tensile strength decreases if the amount in the mixture is more than 300 parts by mass. A mixture of less than 5 parts by mass of the styrenoidal phenol compound does not achieve the effect of the present invention, as the mixture is too small. Conversely, the heating performance decreases when the mixture exceeds 50 parts by mass. If the mixed amount of the sticky resin is less than 20 parts by mass, the wet grip performance decreases. If the mixed amount of the styrenoidal phenol compound is less than 15% by mass, based on the amount of the sticky resin, the hardness at low temperatures decreases and the heat-up performance deteriorates.

[0027] In the second embodiment of the rubber composition according to an embodiment of the present invention, the amount of specific silica mixed is preferably 160 to 280 parts by mass and more preferably 170 to 260 parts by mass, based on 100 parts by mass of the diene rubber. The amount of the styrenoidal phenol compound mixed is preferably from 7 to 45 parts by mass and more preferably from 10 to 40 parts by mass, based on 100 parts by mass of the diene rubber. The amount of the tackifying resin mixed is preferably 25 to 70 parts by mass and more preferably 30 to 60 parts by mass, based on 100 parts by mass of the diene rubber. The amount of the styrenated phenol compound mixed is preferably 20 to 70% by mass, based on the amount of the sticky resin.

[0028] In the second embodiment of the rubber composition according to an embodiment of the present invention, the rubber composition, which further contains a silane adhesion promoter in 2 to 20 wt% and preferably 5 to 16 wt%, based on the amount of silica, wherein the silane adhesion promoter is represented by a composition formula of (2) below, can further improve the wet grip performance. (A) a (B) b (C) c (D) d (R1) e SiO (4-2a-b-c-d-e) / 2 (2) In formula (2) A represents a divalent organic group with a sulfide group, B represents a monovalent hydrocarbon group with 5 to 10 carbon atoms, C represents a hydrolyzable group, D represents an organic group with a mercapto group, R1 represents a monovalent hydrocarbon group with 1 to 4 carbon atoms, and a to e satisfy the relationships: 0 ≤ a < 1, 0 < b < 1, 0 < c < 3, 0 ≤ d < 1, 0 ≤ e < 2 and 0 < 2a + b + c + d + e < 4.

[0029] The silane adhesion promoter (polysiloxane), represented by formula (2), and the manufacturing process thereof are publicly known and described, for example, in WO 2014 / 002750.

[0030] In the above formula (2), A represents a divalent organic group containing a sulfide group. Of these, one group represented by the following formula (12) is preferred. *-(CH2) n -S x -(CH2) n -* (12) In the above formula (12) n represents an integer from 1 to 10, of which an integer from 2 to 4 is preferred. In the above formula (12) x represents an integer from 1 to 6, of which an integer from 2 to 4 is preferred. In the formula (12) above, * indicates a binding position. Specific examples of the group represented by the above formula (12) include *-CH2-S2-CH2-*, *-C2H4-S2-C2H4-*, *-C3H6-S2-C3H6-*, *-C4H8-S2-C4H8-*, *-CH2-S4-CH2-*, *-C2H4-S4-C2H4-*, *-C3H6-S4-C3H6-* and *-C4H8-S4-C4H8-*.

[0031] In the above formula (2), B represents a monovalent hydrocarbon group with 5 to 20 carbon atoms, and specific examples include a hexyl group, an octyl group, and a decyl group. B is preferably a monovalent hydrocarbon group with 5 to 10 carbon atoms.

[0032] In the above formula (2), C represents a hydrolyzable group, and specific examples include alkoxy groups, a phenoxy group, a carboxyl group, and alkenyloxy groups. Of these, one group represented by the following formula (13) is preferred. *-OR 2 (13) In the above formula (13) R 2for an alkyl group with 1 to 20 carbon atoms, an aryl group with 6 to 10 carbon atoms, an aralkyl group (arylalkyl group) with 6 to 10 carbon atoms, or an alkenyl group with 2 to 10 carbon atoms. Of these, an alkyl group with 1 to 5 carbon atoms is preferred. Specific examples of the alkyl group with 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, and an octadecyl group. Specific examples of the aryl group with 6 to 10 carbon atoms include a phenyl group and a tolyl group. Specific examples of the aralkyl group with 6 to 10 carbon atoms include a benzyl group and a phenylethyl group. Specific examples of alkenyl groups with 2 to 10 carbon atoms include a vinyl group, a propenyl group, and a pentenyl group. In the above formula (13), * indicates a binding position.

[0033] In the preceding formula (2), D represents an organic group containing a mercapto group. Of these, one group represented by the following formula (14) is preferred. *-(CH2) m -SH (14) In the above formula (14) m represents an integer from 1 to 10, of which an integer from 1 to 5 is preferred. In the above formula (14), * indicates a binding position. Specific examples of the group represented by the preceding formula (14) include *-CH2SH, *-C2H4SH, *-C3H6SH, *-C4H8SH, *-C5H 10 SH, *-C6H 12 SH, *-C7H 14 SH, *-C8H 16 SH, *-C9H 18 SH and *-C 10 H 20 SH one.

[0034] In the above formula (2), R1 represents a monovalent hydrocarbon group with 1 to 4 carbon atoms.

[0035] In the above formula (2) a to e satisfy the conditions 0 ≤ a < 1, 0 < b < 1, 0 < c < 3, 0 ≤ d < 1, 0 ≤ e < 2 and 0 < 2a + b + c + d + e < 4.

[0036] In the above formula (2) a is preferably 0 < a ≤ 0.50 from the perspective of improving the effect of the present invention. In the above formula (2) b is preferably 0 < b and more preferably 0.10 ≤ b ≤ 0.89 from the perspective of improving the effect of the present invention. In the above formula (2) c is preferably 1.2 ≤ c ≤ 2.0 from the perspective of improving the effect of the present invention. In the above formula (2) d is preferably 0.1 ≤ d ≤ 0.8 from the perspective of improving the effect of the present invention.

[0037] From the perspective of improving the effectiveness of the present invention, the weight-average molecular weight of the polysiloxane is preferably 500 to 2300 and more preferably 600 to 1500. In one embodiment of the present invention, the molecular weight of the polysiloxane is determined by gel permeation chromatography (GPC) using toluene as a solvent, based on a calibration with polysiloxane. The mercapto weight equivalent of the polysiloxane, determined by the sodium thiosulfate solution titration method with the addition of acetic acid / potassium iodide / potassium iodate, is preferably 550 to 700 g / mol and more preferably 600 to 650 g / mol from the point of view of excellent vulcanization reactivity.

[0038] From the perspective of improving the effect of the present invention, the polysiloxane is preferably a polysiloxane comprising 2 to 50 siloxane units (-Si-O-).

[0039] It should be noted that other metals besides a silicon atom (e.g. Sn, Ti and Al) are not present in the main chain of the polysiloxane.

[0040] The process for producing polysiloxane is publicly known and can be carried out, for example, according to the process disclosed in WO 2014 / 002750. Other components

[0041] The rubber composition in one embodiment of the present invention may, in addition to the components described above, be mixed with vulcanizing or crosslinking agents; vulcanizing or crosslinking accelerators; various fillers, such as clay, talc, and calcium carbonate; aging retarders; plasticizers; resins; and various additives commonly mixed in rubber compositions, such as hardening agents. The additives are kneaded together using a conventional method to obtain a composition that can then be used for vulcanization or crosslinking. The amounts of these additives mixed may be any quantity commonly added in related prior art, provided that this does not hinder the objective of the present invention. In the second embodiment of the present invention, the use of aluminum hydroxide can further improve the wet grip performance. In a case where aluminum hydroxide is mixed, the mixed quantity is preferably 20 to 80 parts by mass, based on 100 parts by mass of the diene rubber.

[0042] Since the rubber composition in the first embodiment of the present invention can improve dry grip performance and graining performance and can improve the heat-induced loss of grip performance by suppressing the temperature dependence of the hardness, the rubber composition can accordingly be used for a tread, in particular a protector tread of a tire, and preferably for a tread, in particular a protector tread of a racing tire.

[0043] Since the rubber composition in the second embodiment of the present invention achieves excellent steering stability, improves wet grip performance, particularly warm-up performance, improves fracture toughness, and achieves excellent abrasion resistance, the rubber composition can be used accordingly for a tread, in particular a protective tread of a tire, and preferably for a tread, in particular a protective tread of a racing tire. The tire according to one embodiment of the present invention is preferably a pneumatic tire that can be filled with any gas, including air and inert gases such as nitrogen.

[0044] The present invention is described in more detail by means of examples and comparative examples, but the present invention is not limited by these examples. Examples: Standard example 1, examples 1 and 2, and comparison examples 1 to 6. Sample preparation

[0045] According to the composition (parts by mass) shown in Table 1, the components other than the vulcanizing agents (vulcanizing accelerator and sulfur) were kneaded for 5 minutes in a sealed 1.7-1 Banbury mixer. The composition was then removed from the mixer and cooled to room temperature. The rubber composition was then prepared by placing the composition back into the same Banbury mixer, adding the vulcanizing agents, and kneading. Next, the resulting rubber composition was vulcanized in a predefined mold at 150°C for 30 minutes in a press to produce a vulcanized rubber test piece. The vulcanized rubber sample was then subjected to the test procedures described below to measure its physical properties.

[0046] tan δ (60 °C): The tan δ (60 °C) was measured under conditions of a strain deformation of 10 ± 2%, a vibration frequency of 20 Hz, and a temperature of 60 °C using a viscoelastic spectrometer (available from Toyo Seiki Seisaku-sho, Ltd.) according to JIS K 6394:2007. The results are expressed as index values, with the standard example assigned a value of 100. A higher index value indicates a larger tan δ and superior wet grip performance. M300 (RT) / M300 (60 °C): The tensile test was performed at room temperature (RT) or at 60 °C according to JIS K 6251 (No. 3 barbell used), and thus a modulus of deformation of 300% (M300) was determined. The results are expressed as index values, with the standard example assigned a value of 100. A lower index value indicates less temperature dependence and better performance with respect to heat-induced loss of grip. Embrittlement temperature: The embrittlement temperature was measured according to "Low-temperature embrittlement" from JIS K 6261 "Rubber, vulcanized or thermoplastic—Determination of low-temperature properties." The results are expressed as index values, with the standard example assigned a value of 100. A lower index value indicates superior abrasion resistance and grip performance at low temperatures. Tensile strength (RT): The elongation at break was evaluated at room temperature in a tensile test according to JIS K 6251. The results are expressed as index values, with the standard example assigned a value of 100. A higher index value indicates superior tensile strength, superior abrasion resistance, and superior grain resistance performance.

[0047] The results are shown in Table 1. [Table 1-I] Standard example 1 Comparative example 1 Example 1 Example 2 Comparative example 2 SBR 1 *1 137,5 137,5 137,5 137,5 137,5 SBR 2 *2 - - - - - Soot 1 *3 120,0 120,0 120,0 120,0 - Soot 2 *4 - - - - 120,0 Soot 3 *5 - - - - Soot 4 *6 - - - - - Sticky resin *7 40,0 40,0 40,0 40,0 40,0 Öl *8 70,0 55,0 55,0 55,0 55,0 Styrenoidal phenol compound 1 *9 - 25,0 - - - Styrenoidal phenol compound 2 *10 - - 25,0 - 25,0 Styrenoidal phenol compound 3 *11 - - - 25,0 - Stearic acid *12 2,0 2,0 2,0 2,0 2,0 Zinc oxide *13 2,0 2,0 2,0 2,0 2,0 Aging retardant 14 2,0 2,0 2,0 2,0 2,0 Vulcanization accelerator *15 2,0 2,0 2,0 2,0 2,0 Sulfur *16 1,5 1,5 1,5 1,5 1,5 Measurement result Tan δ (60°C) 100 97 102 105 94 M300 (RT) / M300 (60 °C) 100 92 95 96 96 embrittlement temperature 100 93 95 97 95 Tensile strength (RT) 100 100 102 103 104 [Table 1-II] Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 SBR 1 *1 137,5 137,5 137,5 - SBR 2 *2 - - - 137,5 Soot 1 *3 - - 120,0 120,0 Soot 2 *4 - - - - Soot 3 *5 120,0 - - - Soot 4 *6 - 120,0 - - Sticky resin *7 40,0 40,0 80,0 40,0 Öl *8 55,0 55,0 55,0 55,0 Styrenoidal phenol compound 1 *9 - - - - Styrenoidal phenol compound 2 *10 25,0 25,0 10,0 25,0 Styrenoidal phenol compound 3 *11 - - - - Stearic acid *12 2,0 2,0 2,0 2,0 Zinc oxide *13 2,0 2,0 2,0 2,0 Aging retardant 14 2,0 2,0 2,0 2,0 Vulcanization accelerator *15 2,0 2,0 2,0 2,0 Sulfur *16 1,5 1,5 1,5 1,5 Measurement result Tan δ (60°C) 111 107 125 95 M300 (RT) / M300 (60 °C) 94 95 117 89 embrittlement temperature 94 93 114 90 Tensile strength (RT) 94 94 107 98 *1: SBR 1 (Nipol NS522, available from ZS Elastomer Co., Ltd.) (Styrene content = 39% by mass; Oil extender content: 37.5 parts by mass based on 100 parts by mass of SBR) *2: SBR 2 (Nipol NS460, available from ZS Elastomer Co., Ltd.) (Styrene content = 25% by mass; Oil extender content: 37.5 parts by mass based on 100 parts by mass of SBR) *3: Carbon black 1 (#95, available from Asahi Carbon Co., Ltd. (nitrogen adsorption specific surface area (N2SA) = 147 m²) 2 / g: N2SA / IA = 0.98)) *4: Carbon black 2 (SEAST 7HM, available from Tokai Carbon Co., Ltd.) (nitrogen adsorption specific surface area (N2SA) = 126 m² 2 / g; N2SA / IA = 1.05)) *5: Soot 3: CD2019, available from Columbian Carbon Company (nitrogen adsorption specific surface area (N2SA) = 340 m² 2 / g; N2SA / IA = 1.05)) *6: Carbon black 4 (TOKA BLACK #5500, available from Tokai Carbon Co., Ltd.) (nitrogen adsorption specific surface area (N2SA) = 225 m² 2 / g; N2SA / IA = 0.88)) *7: Tackifying resin (NEOPOLYMER 140, available from ENEOS Corporation; C9 petroleum resin) *8: Oil (Extract No. 4S, available from Showa Shell Sekiyu KK) *9: Styrenated phenol compound 1 (SP-F, available from Sanko Co., Ltd.; monostyrenated phenol: 65 mol% or more; distyrenated phenol: 32 mol% or less; tristyrenated phenol: 1 mol% or less) *10: Styrenated phenol compound 2 (SP-24, available from Sanko Co., Ltd.; monostyrolated phenol: 0 mol%; distyrolated phenol: 60 mol% or more; tristyrolated phenol: 40 mol% or less) *11: Styrenated phenol compound 3 (TSP, available from Sanko Co., Ltd.; monostyrolated phenol: 0 mol%; distyrolated phenol: 30 mol% or less; tristyrolated phenol: 65 mol% or more) *12: Stearic acid (Stearic acid spheres YR, available from NOF Corporation) *13: Zinc oxide (Zinc oxide III, available from Seido Chemical Industry Co., Ltd.) *14: Aging retardant (6PPD, available from Flexsys) *15: Vulcanization accelerator (NOCCELER CZ-G, available from Ouchi Shinko Chemical Industrial Co., Ltd.) *16: Sulfur (oil-treated sulfur powder “Golden Flower” available from Tsurumi Chemical Industry, Co., Ltd.)

[0048] As can be seen from the results in Table 1, the rubber compositions of Examples 1 and 2 each contained 100 parts by mass of diene rubber containing an SBR with a styrene content of 30 wt% or more, 50 to 200 parts by mass of specific carbon black, 5 to 50 parts by mass of the styrenated phenol compound represented by structural formula (1), and 20 parts by mass or more of the tackifying resin, and the mixed amount of the styrenated phenol compound was 15 wt% or more, based on the amount of the tackifying resin, and thus the dry grip performance and the graining performance were improved, and the heat-induced loss of grip performance was likewise improved by suppressing the temperature dependence of the hardness, compared with those of the rubber composition of Standard Example 1. On the other hand, in comparative example 1, n in the structural formula (1) 1 was included, and the dry grip performance decreased. In comparative examples 2 and 3, the N2SA / IA of the carbon black exceeded the upper limit specified for an embodiment of the present invention, and the dry grip performance or the fracture toughness decreased. In comparative example 4, the N2SA / IA of the carbon black was smaller than the lower limit specified for an embodiment of the present invention, and the fracture toughness decreased. In comparative example 5, the amount of the styrofoamed phenol compound mixed was less than 15% by mass, based on the amount of the sticky resin, and the temperature dependence and the embrittlement temperature worsened. In comparative example 6, the amount of styrene in the SBR was less than the lower limit specified for one embodiment of the present invention, and the dry grip performance and the tensile strength deteriorated. Standard example 2, examples 3 to 6 and comparative examples 7 to 11 Sample preparation

[0049] According to the composition (parts by mass) shown in Table 2, the components other than the vulcanizing agents (vulcanizing accelerator and sulfur) were kneaded for 5 minutes in a sealed 1.7-1 Banbury mixer. The composition was then removed from the mixer and cooled to room temperature. The rubber composition was then prepared by placing the composition back into the same Banbury mixer, adding the vulcanizing agents, and kneading. Next, the resulting rubber composition was vulcanized in a predefined mold at 150 °C for 30 minutes in a press to produce a vulcanized rubber test piece. The vulcanized rubber sample was then subjected to the test procedures described below to measure its physical properties.

[0050] tan δ (0 °C): The tan δ (0 °C) was measured under conditions of strain deformation of 10 ± 2%, a vibration frequency of 20 Hz, and a temperature of 0 °C using a viscoelastic spectrometer (available from Toyo Seiki Seisaku-sho, Ltd.) according to JIS K 6394:2007. The results are expressed as index values, with the standard example assigned a value of 100. A higher index value indicates superior wet grip performance. Steering stability: The hardness was measured at a temperature of 60 °C using a type-A durometer according to JIS K 6253. The results are expressed as index values, with the standard example assigned a value of 100. A higher index value indicates greater hardness and superior steering stability. Heating performance: Hardness was measured at a temperature of 10 °C using a type A durometer according to JIS K 6253.The results were expressed as index values, with the standard example assigned a value of 100. A lower index value indicates lower hardness at low temperatures and superior warm-up performance (low-temperature grip performance). Tensile strength (RT): Elongation at break was evaluated at room temperature in a tensile test according to JIS K 6251. The results were expressed as index values, with the standard example assigned a value of 100. A higher index value indicates superior tensile strength and superior abrasion resistance.

[0051] The results are listed in Table 2. [Table 2-I] Standard example 2 Comparative example 7 Example 3 Example 4 SBR1 *17 137,5 137,5 137,5 137,5 SBR2 *18 - - - - Silica 1 *19 200,0 200,0 200,0 200,0 Silica 2 *20 - - - - Soot *21 10,0 10,0 10,0 10,0 Sticky resin *22 50,0 50,0 50,0 50,0 Silane adhesion promoter 1 *23 16,0 16,0 16,0 16,0 Silane adhesion promoter 2 *24 - - - - Öl *25 60,0 30,0 30,0 30,0 Styrenoidal phenol compound 1 *26 30,0 - - Styrenoidal phenol compound 2 *27 - - 30,0 - Styrenoidal phenol compound 3 *28 - - - 30,0 Stearic acid *29 2,0 2,0 2,0 2,0 Zinc oxide *30 2,0 2,0 2,0 2,0 Aging retardants *31 2,0 2,0 2,0 2,0 Vulcanization accelerator 1 *32 1,5 1,5 1,5 1,5 Vulcanization accelerator 2 *33 2,0 2,0 2,0 2,0 Sulfur *34 1,5 1,5 1,5 1,5 Aluminum hydroxide *35 - - - - Measurement result Wet adhesion: tan δ (0°C) 100 98 102 104 Steering stability (hardness (60°C)) 100 98 101 104 Heating capacity (hardness (10 °C)) 100 97 95 92 Tensile strength (RT) 100 99 101 102 [Table 2-II] Example 5 Comparative example 8 Comparative example 9 Comparative example 10 SBR1 *17 137,5 137,5 137,5 137,5 SBR2 *18 - - - - Silica 1 *19 200,0 - 130,0 200,0 Silica 2 *20 - 200,0 - - Soot *21 10,0 10,0 10,0 10,0 Sticky resin *22 50,0 50,0 50,0 50,0 Silane adhesion promoter 1 *23 - 16,0 10,4 16,0 Silane adhesion promoter 2 *24 16,0 - - - Öl *25 30,0 30,0 30,0 20,0 Styrenoidal phenol compound 1 *26 - - - - Styrenoidal phenol compound 2 *27 30,0 30,0 30,0 10,0 Styrenoidal phenol compound 3 *28 - - - - Stearic acid *29 2,0 2,0 2,0 2,0 Zinc oxide *30 2,0 2,0 2,0 2,0 Aging retardants *31 2,0 2,0 2,0 2,0 Vulcanization accelerator 1 *32 1,5 1,5 1,5 1,5 Vulcanization accelerator 2 *33 2,0 2,0 2,0 2,0 Sulfur *34 1,5 1,5 1,5 1,5 Aluminum hydroxide *35 - - - - Measurement result Wet adhesion: tan δ (0°C) 107 113 114 125 Steering stability (hardness (60°C)) 102 91 82 118 Heating capacity (hardness (10 °C)) 89 92 80 110 Tensile strength (RT) 103 92 105 117 [Table 2-III] Comparative example 11 Example 6 SBR1 *17 - 137,5 SBR2 *18 137,5 - Silica 1 *19 200,0 120,0 Silica 2 *20 - - Soot *21 10,0 10,0 Sticky resin *22 80,0 50,0 Silane adhesion promoter 1 *23 16,0 16,0 Silane adhesion promoter 2 *24 - - Öl *25 30,0 30,0 Styrenoidal phenol compound 1 *26 - - Styrenoidal phenol compound 2 *27 30,0 30,0 Styrenoidal phenol compound 3 *28 - - Stearic acid *29 2,0 2,0 Zinc oxide *30 2,0 2,0 Aging retardants *31 2,0 2,0 Vulcanization accelerator 1 *32 1,5 1,5 Vulcanization accelerator 2 *33 2,0 2,0 Sulfur *34 1,5 1,5 Aluminum hydroxide *35 - 40,0 Measurement result Wet adhesion: tan δ (0°C) 95 106 Steering stability (hardness (60°C)) 96 103 Heating capacity (hardness (10 °C)) 90 97 Tensile strength (RT) 99 101 *17: SBR 1 (Nipol NS522, available from ZS Elastomer Co., Ltd.) (Styrene content = 39% by mass; Oil extender content: 37.5 parts by mass based on 100 parts by mass of SBR) *18: SBR 2 (Nipol NS460, available from ZS Elastomer Co., Ltd.) (Styrene content = 25% by mass; Oil extender content: 37.5 parts by mass based on 100 parts by mass of SBR) *19: Silica 1 (Ultrasil 7000 GR, available from Evonik Industries AG; nitrogen adsorption specific surface area (N2SA) = 175 m² 2 / G) *20: Silica 2 (Zeosil 1085GR, available from Solvay (nitrogen adsorption specific surface area (N2SA) = 80 m²) 2 / G) *21: Carbon black (SEAST 7HM, available from Tokai Carbon Co., Ltd.) *22: Tackifying resin (NEOPOLYMER 140, available from ENEOS Corporation; C9 petroleum resin) *23: Silane adhesion promoter 1 (Si 69, available from Evonik Industries AG) *24: Silane adhesion promoter 2 (silane adhesion promoter fulfilling the above compositional formula of (2) produced according to a manufacturing process described in WO 2014 / 002750; compositional formula = (-C3H6-S4-C3H6-) 0,083 (-C8H17 ) 0,667 (-OC2H5) 1,50 (-C3H6SH) 0,167 SiO 0,75 ; average molecular weight = 860) *25: Oil (Extract No. 4S, available from Showa Shell Sekiyu KK) *26: Styrenated phenol compound 1 (SP-F, available from Sanko Co., Ltd.; monostyrolated phenol: 65 mol% or more; distyrolated phenol: 32 mol% or less; tristyrolated phenol: 1 mol% or less) *27: Styrenated phenol compound 2 (SP-24, available from Sanko Co., Ltd.; monostyrolated phenol: 0 mol%; distyrolated phenol: 60 mol% or more; tristyrolated phenol: 40 mol% or less) *28: Styrenated phenol compound 3 (TSP, available from Sanko Co., Ltd.; monostyrolated phenol: 0 mol%; distyrolated phenol: 30 mol% or less; tristyrolated phenol: 65 mol% or more) *29: Stearic acid (Stearic acid spheres YR, available from NOF Corporation) *30: Zinc oxide (Zinc oxide III, available from Seido Chemical Industry Co., Ltd.) *31: Aging retardant (6PPD, available from Flexsys) *32: Vulcanization Accelerator 1 (SANCELER DG, available from Sanshin Chemical Industry Co., Ltd.) *33: Vulcanization Accelerator 2 (NOCCELER CZ-G, available from Ouchi Shinko Chemical Industrial Co., Ltd.) *34: Sulfur (oil-treated sulfur powder “Golden Flower”, available from Tsurumi Chemical Industry, Co., Ltd.) *35: Aluminium hydroxide (trade name: BF013, available from Nippon Light Metal Company, Ltd.)

[0052] As can be seen from the results in Table 2, the rubber compositions of Examples 3 to 6 each contained 100 parts by mass of diene rubber containing an SBR with a styrene content of 30 wt% or more, 150 to 300 parts by mass of specific carbon black, 5 to 50 parts by mass of the styrenoidal phenol compound represented by structural formula (1), and 20 parts by mass or more of the tackifying resin, and the mixed amount of the styrenoidal phenol compound was 15 wt% or more, based on the amount of the tackifying resin, and thus the steering stability was excellent, the wet grip performance, especially the warm-up performance (wet grip performance at low temperatures), the fracture strength was increased, and the abrasion resistance was excellent, compared with those of the rubber composition of Standard Example 2. On the other hand, in comparative example 7 n in structural formula (1) 1, the wet grip performance, steering stability and abrasion resistance decreased. In comparative example 8, the N2SA of the silica specified for an embodiment of the present invention was smaller than the lower limit, and the steering stability and abrasion resistance decreased. In comparative example 9, the amount of silica mixed was less than the lower limit specified in the present invention, and the steering stability decreased. In comparative example 10, the mixed amount of the styrenoidal phenol compound was less than 15 mass-%, based on the amount of the sticky resin, and the steering stability decreased. In comparative example 11, the amount of styrene in the SBR was less than the lower limit specified for an embodiment of the present invention, and the dry grip performance, steering stability and abrasion resistance deteriorated. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2016113482 A

[0005] JP 2007186567 A

[0005] WO 2014 / 002750 [0029, 0040, 0051]

Claims

[1] Rubber composition for tires, the rubber composition comprising: 100 parts by mass of a diene rubber containing a styrene-butadiene copolymer rubber having a styrene content of 30% by mass or more, and 50 to 200 parts by mass of carbon black having a nitrogen adsorption surface area N2SA of 100 to 500 m² 2 / g and N2SA / IA, which is a ratio of the nitrogen adsorption specific surface area N2SA (unit: m²) 2 / g) to an iodine adsorption number IA (unit: mg / g), of 0.90 to 1.03; comprising 5 to 50 parts by mass of a styrolated phenol compound represented by the structural formula (1); and comprising 20 parts by mass or more of a sticky resin; wherein a mixed amount of the styrolated phenol compound represents 15 wt% or more based on an amount of the sticky resin: wherein n is 2 or 3. [2] Rubber composition for tires according to claim 1, wherein the softening point of the tackifying resin is between 60 and 180 °C. [3] Rubber composition for tires according to claim 1, wherein the tackifying resin is one or more types selected from the group consisting of a C9 petroleum resin, a phenolic resin, a coumaron indene resin, a terpene resin, a styrene resin, an acrylic resin, a rosin resin and a dicyclopentadiene resin. [4] Tires comprising the rubber composition for tires according to claim 1 in a protector tread. [5] Rubber composition for tires, the rubber composition comprising: 100 parts by mass of a diene rubber containing a styrene-butadiene copolymer rubber having a styrene content of 30% by mass or more, and 150 to 300 parts by mass of silica having a nitrogen adsorption surface area N2SA of 100 to 300 m² 2 / g; comprising 5 to 50 parts by mass of a styrofoam phenol compound represented by the structural formula (1); and comprising 20 parts by mass or more of a sticky resin; wherein a mixed quantity of the styrofoam phenol compound represents 15 wt% or more based on a quantity of the sticky resin: wherein n is 2 or 3. [6] Rubber composition for tires according to claim 5, wherein the softening point of the tackifying resin is between 60 and 180 °C. [7] Rubber composition for tires according to claim 5, wherein the tackifying resin is one or more types selected from the group consisting of a C9 petroleum resin, a phenolic resin, a coumaron indene resin, a terpene resin, a styrene resin, an acrylic resin, a rosin resin and a dicyclopentadiene resin. [8] Rubber composition for tires according to claim 5, further comprising 2 to 20 wt% of a silane adhesion promoter based on an amount of silica, wherein the silane adhesion promoter containing a mercapto group is represented by a compositional formula of (2): (A) a (B) b (C) c (D) d (R1) e SiO( 4-2a-b-c-d-e ) / 2 (2) wherein A represents a divalent organic group with a sulfide group, B represents a monovalent hydrocarbon group with 5 to 10 carbon atoms, C represents a hydrolyzable group, D represents an organic group with a mercapto group, R1 represents a monovalent hydrocarbon group with 1 to 4 carbon atoms, and a to e satisfy the relationships: 0 ≤ a < 1, 0 < b < 1, 0 < c < 3, 0 ≤ d < 1, 0 ≤ e < 2 and 0 < 2a + b + c + d + e < 4. [9] Tires comprising the rubber composition for tires according to claim 5 in a protector tread.