Rubber composition for pneumatic tires and pneumatic tires made therefrom

Abstract

A rubber composition for pneumatic tires comprising a polymer with a low glass transition temperature and a hydrocarbon resin compound, and a pneumatic tire made therefrom.

Description

[Technical Field]

[0001] The present invention relates to a rubber composition for pneumatic tires, the use of the rubber composition in the manufacture of pneumatic tires, and a pneumatic tire comprising or prepared from the rubber composition. The pneumatic tire is suitable for passenger cars. [Background technology]

[0002] Pneumatic tires for automobiles can be designed to perform well under specific conditions. For example, winter tires remain soft even at low temperatures (e.g., below 7°C) and therefore provide traction on snow or ice. Such tires are known, for example, from European Patent Application Publication No. 2643400(A1). These are not suitable for use in warmer temperatures because the softer compound wears more easily, shortening the tire's lifespan. Wet performance may also be reduced. Summer tires are designed for high performance in warm conditions and can improve cornering and braking capabilities while still being suitable for wet conditions. This balance can be achieved by using a stiffer compound, i.e., a compound that softens at higher temperatures than winter tire compounds. However, this results in reduced grip at low temperatures, making these tires unsuitable for winter conditions.

[0003] Manufacturing pneumatic tires that perform well under all conditions is a particular challenge for tire designers. Tire designers must provide balanced performance suitable for various driving conditions, including wet, dry, and winter conditions, on various surface types, while also offering long tread life. Achieving these objectives involves considering the tire's softening temperature (the glass transition temperature of the elastomer in the compound (T)). gbalancing parameters including those shown by ) and its viscoelastic properties (shown by the ratio (tanδ) between the pain effect and the loss elastic modulus and the storage elastic modulus). In particular, it can be a challenge to prepare a tire having good winter performance that maintains good wet and dry performance. Such pneumatic tires typically use an elastomer having a low T g and it is necessary to balance it with other factors (e.g., the filling amounts of fillers and resins / plasticizers) to provide appropriate performance and a long tire life under wet and dry conditions. As a result, the designers of pneumatic tires must carefully select the combination of elastomers, fillers, and resins / plasticizers that make up the rubber compound. Tires designed for various conditions are known, for example, from International Publication No. 2022 / 130201 (A1). However, there is still a need in the art to provide a pneumatic tire that provides balanced performance over various driving conditions including good winter performance.

[0004] An object of the present invention is to provide a solution to one or more of the problems identified above.

Summary of the Invention

[0005] The inventors have used a rubber composition comprising an elastomer having a low T g and a combination of resins present in a specific ratio to prepare a tire having a good balance between wet performance, rolling resistance, and dry handling, and good winter performance.

[0006] Viewed from a first aspect, the present invention is a rubber composition for a pneumatic tire, comprising an optionally functionalized diene elastomer having a glass transition temperature (T g ) of -130°C to -30°C, and an optionally functionalized copolymer of styrene and butadiene having a T g of -90°C to -20°C, A resin system present in an amount of at least 30 phr, having a T of at least 50 °C g and a first hydrocarbon resin having and a second hydrocarbon resin having a T of at least 20 °C g and including a resin system, where the first hydrocarbon resin and the second hydrocarbon resin are different, and the ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin on a parts per hundred rubber (phr) basis per 100 parts of rubber is greater than 0.2:1, relating to a rubber composition.

[0007] From a second aspect, the present invention relates to the use of the rubber composition described above in the manufacture of pneumatic tires.

[0008] From a third aspect, the present invention relates to a pneumatic tire including the rubber composition described above.

[0009] From a fourth aspect, the present invention relates to a pneumatic tire prepared from the rubber composition described above.

[0010] Further advantageous features of the present invention are described in the following description of the present invention, the drawings, and the dependent claims.

Brief Description of the Drawings

[0011] [Figure 1] The change in the elastic modulus (E’30 °C) at 30 °C in the tread piece of a pneumatic tire when the content of polybutadiene rubber in the composition for preparing polybutadiene rubber increases is shown for various resin ratios. [Figure 2] Compare tan δ at 0 °C (an index for wet handling) and E’30 °C (an index for dry handling) for various resin ratios.

Modes for Carrying Out the Invention

[0012] The present invention is in part based on the discovery by the inventors that increasing the amount of low-T g elastomer in a rubber composition to lower T g (thus improving winter performance) can have an adverse effect on other parameters including wet performance and dry handling. Certain resins increase the dispersion of fillers in the rubber composition (thus reducing the stiffness of the compound and improving dry handling), while other resins reduce the dispersion of fillers and increase the stiffness of the compound, which can have an adverse effect on dry handling. When these resins are present in a specific ratio, an interaction effect and / or synergistic effect is observed on the properties of the tire made from the compound, which results in an improvement in dry handling when a large amount of low-T g (e.g., below 0 °C) elastomer is present in the rubber composition. As a result, the compositions of the present invention are well suited for the preparation of tires having balanced performance, particularly for the preparation of tires having good winter performance.

[0013] According to the above, in one aspect, the present invention is a rubber composition for a pneumatic tire, comprising - an optionally functionalized diene elastomer having a glass transition temperature ( Tg ) of -150 °C to -50 °C, - an optionally functionalized copolymer of styrene and butadiene having a T g of -90 °C to -20 °C, - a resin system present in an amount of at least 30 phr, - a first hydrocarbon resin having a T g of at least 50 °C and - a second hydrocarbon resin having a T g of at least 20 °C, the resin system comprising, where the first hydrocarbon resin and the second hydrocarbon resin are different, and the ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin on the basis of parts per hundred parts of rubber (phr) is greater than 0.2:1, relating to the rubber composition.

[0014] Hydrocarbon resin The resin is produced under standard ambient temperature and pressure (25°C, 10°C). 5 Hydrocarbon resins are solid or highly viscous compounds at Pa. While essentially carbon and hydrogen-based, they may contain other atoms. They can be aliphatic, alicyclic, aromatic, hydrogenated aromatic, and aliphatic / aromatic, i.e., based on aliphatic and / or aromatic monomers. Hydrocarbon resins also possess thermoplastic properties, meaning they soften upon heating and are therefore moldable.

[0015] Examples of such hydrocarbon resins include cyclopentadiene homopolymer or copolymer resins (abbreviated as CPD), dicyclopentadiene homopolymer or copolymer resins (abbreviated as DCPD), terpene homopolymer or copolymer resins, rosin-based resins, C5 homopolymer or copolymer resins which may be partially or completely hydrogenated, C9 homopolymer or copolymer resins which may be partially or completely hydrogenated, alpha-methylstyrene homopolymer or copolymer resins, and combinations thereof, selected from the group. Any hydrocarbon resin that satisfies the glass transition temperature requirement can be used in conjunction with the present invention.

[0016] In this invention, the first hydrocarbon resin and the second hydrocarbon resin are different, and they may differ by any structural features and / or measurable properties. For example, the hydrocarbon resins may be from different classes of resins, e.g., terpene-based and rosin-based or partially hydrogenated C5 and rosin-based resins. In addition to or instead of the above, they may differ in properties such as glass transition temperature, softening point, aromaticity, and / or polarity.

[0017] The first hydrocarbon resin may have a glass transition temperature higher than that of the second hydrocarbon resin. The first hydrocarbon resin may have a glass transition temperature 10°C to 40°C higher than that of the second hydrocarbon resin, preferably 15°C to 30°C higher. The glass transition temperature of a material is the temperature (or temperature range) at which, as the temperature increases, the material transitions from a hard, relatively brittle "glassy" state to a viscous or rubbery state. This is measured by DSC (Differential Scanning Calorimetry). For example, in one embodiment, the first hydrocarbon resin has a glass transition temperature 17°C higher than that of the second hydrocarbon resin. In another embodiment, the first hydrocarbon resin has a glass transition temperature 28°C higher than that of the second hydrocarbon resin.

[0018] The first hydrocarbon resin may have a lower aromaticity than the second hydrocarbon resin. The aromaticity values ​​as defined herein are: 1 The aromaticity is measured by 1H NMR as the content of aromatic protons having a chemical shift of 6.5 to 8.5 ppm. For example, the aromaticity of the first hydrocarbon resin may be 1% to 10% lower than that of the second hydrocarbon resin, preferably 3% to 7% lower, for example, 5.5% or 4.5% lower than that of the second hydrocarbon resin. In this regard, the first hydrocarbon resin may have an aromaticity of less than 4%, preferably 0% to 3%. The second hydrocarbon resin may have an aromaticity of at least 4%, preferably 5% to 15%, more preferably 5.5% to 7.5%.

[0019] The inventors have found that increasing the ratio of the first hydrocarbon resin to the second hydrocarbon resin in the rubber composition of the present invention improves the dispersion of the filler (and thus reduces stiffness), while decreasing the ratio of the first hydrocarbon to the second hydrocarbon resin reduces the dispersion of the filler and increases stiffness. When the first hydrocarbon resin and the second hydrocarbon resin are present in a specific ratio, interaction effects and / or synergistic effects are observed on the properties of the tire made from the compound, which is due to the low T in the rubber composition. gAs the amount of elastomer increases, dry handling improves. As a result, the compositions of the present invention are well suited for preparing tires with balanced performance, in particular for preparing tires with good winter performance. In preferred embodiments, the ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin on a PHR basis is greater than 0.2:1, preferably 0.3:1 to 10:1, more preferably 0.5:1 to 8:1, and more preferably 0.9:1 to 5:1. The inventors have found that interaction / synergistic effects are particularly pronounced when the resin ratios are within these ranges.

[0020] The first hydrocarbon resin has a glass transition temperature (T) of 50°C to 90°C, preferably 55°C to 80°C, for example, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, or 80°C. g ) may have. In a preferred embodiment, the first hydrocarbon resin has T due to these values. g It is a terpene-based resin.

[0021] The second hydrocarbon resin is suitable for use at temperatures of 20°C to 80°C, preferably 30°C to 70°C, more preferably 40°C to 60°C, for example, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, or 60°C. g It may have the following properties. In a preferred embodiment, the second hydrocarbon resin has T values ​​according to these properties. g It is a rosin-based resin that has the following properties.

[0022] The first hydrocarbon resin may include (for example, consist of) terpene resins. Terpene resins include resins that are mixtures of terpene monomers (referred to herein as heteropolymers) or terpene homopolymers, where the terpene homopolymer may be an α-pinene homopolymer. These may include, for example, oligoterpene resins (i.e., resins prepared from terpenes as the sole monomer), terpene hydrocarbon resins (i.e., resins prepared from terpenes and non-terpene hydrocarbon monomers), and / or terpene phenolic resins (i.e., resins prepared from terpenes and phenolic compounds). The basic molecular formula of terpenes is (C5H8) n The formula is as follows: where n is the number of bonded isoprene units and is greater than 1. Examples of terpenes suitable for use in terpene resins include, but are not limited to, isoprene, limonene, terpenes, α-pinene, β-pinene, δ-3-carene, β-phellandrene, and the pyrolysis products of α-pinene, β-pinene, δ-3-carene, δ-2-carene, turpentine, and combinations thereof. For example, a terpene resin may contain α-pinene, or a mixture of α-pinene and β-pinene monomers. A terpene resin may not contain substantially limonene, and the amount of limonene is less than 10% by weight, preferably less than 5% by weight, and more preferably less than 1% by weight, based on the total amount of the terpene resin. Any terpene resin that satisfies the glass transition temperature requirement can be used in the present invention. In preferred embodiments, the terpene resin comprises a mixture of α-pinene monomer and β-pinene monomer, with limonene present in an amount of less than 10% by weight. A suitable terpene resin is Kraton Silvatraxx 8115.

[0023] The softening point of terpene resins is at least 70°C, preferably 70°C to 160°C, more preferably 100°C to 130°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, or 130°C. The softening point of a material is the temperature at which it softens beyond a certain degree of softness, measured using a ring-and-ball apparatus according to ISO 4625.

[0024] The aromaticity of the terpene resin, as measured by NMR, may be greater than 0, preferably 0.1 to 5, and preferably 1.

[0025] In addition to or instead of the foregoing, the first hydrocarbon resin may include a partially hydrogenated C5 resin. As used herein, the term “C5 resin” refers to a resin obtained by polymerization of a decomposed naphtha feed containing C5 monomers. C5 monomers include olefins, linear conjugated diolefins, and cyclic conjugated diolefins. Other monomers may be further present in the feed, including, but not limited to, dicyclopentadiene (DCPD).

[0026] In one embodiment, the C5 resin for use in the present invention can be obtained by copolymerization of a C5 monomer with a dicyclopentadiene (DCPD) monomer. If DCPD monomers are present, they are generally provided in small amounts. For example, the DCPD content in the feed used to produce the resin may be less than about 5% by weight, for example, less than about 2% by weight. Preferably, the C5 resin may contain monomer units derived from the C5 monomer and DCPD. Thus, a partially hydrogenated C5 resin may contain a copolymer of partially hydrogenated C5 and dicyclopentadiene DCPD, preferably with DCPD present in an amount of less than 5% by weight of the C5 and DCPD monomers. However, in another embodiment, the feed used to provide the C5 resin may be free of any DCPD monomers. These monomers can be removed from the feed stream by methods generally known in the art. Thus, in one embodiment, the C5 resin may essentially consist of monomer units derived from the C5 monomer.

[0027] As used herein, the term “partially hydrogenated” means that the resin component contains less than 100% olefin protons, and this 1This can be determined by 1H NMR spectroscopy. Partially hydrogenated resins are well known in the art and can have different degrees of hydrogenation. In some embodiments, a partially hydrogenated resin may contain less than 95% olefin protons, more preferably less than 90% olefin protons. In some embodiments, it may contain less than 75% olefin protons, for example less than 50% olefin protons. In some embodiments, a partially hydrogenated resin may contain less than 40% olefin protons, less than 25% olefin protons, less than 15% olefin protons, or less than 10% olefin protons. For example, it may contain less than 9%, less than 8%, less than 7%, or less than 6% olefin protons. In one embodiment, a partially hydrogenated resin may contain about 5% or more olefin protons. For example, it may contain 5% to 90% olefin protons. In one embodiment, a partially hydrogenated resin may contain about 5% olefin protons, i.e., it is about 95% hydrogenated. A suitable partially hydrogenated C5 resin is Eastman Impera E1780.

[0028] The softening point of the partially hydrogenated C5 resin may be at least 70°C, preferably 70°C to 160°C, more preferably 110°C to 150°C, for example, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, or 150°C.

[0029] 1 The aromaticity of the partially hydrogenated C5 resin, as measured by 1H NMR, may be greater than 0, preferably 0.1 to 5, and preferably 2.

[0030] The second type of hydrocarbon resin may include (or may consist of) rosin resins. Rosin resins include resins that are mixtures of isomeric organic acids (e.g., resin acids or rosin acids) characterized by a common structure containing three C6 condensed rings, a double bond, and a single carboxyl group. Rosin is a solid resin material that occurs naturally in pine trees. There are three main sources of rosin: (1) gum rosin derived from oil-containing resin extrudes of living pine trees, (2) wood rosin derived from oil-containing resin contained in mature stumps, and (3) tall oil rosin derived from liquid waste carboxyl groups recovered as a by-product in the kraft paper industry. The main component of rosin is typically abietic acid. Rosin resins include rosin ester resins, which are esters of rosin with polyhydric alcohols. The polyhydric alcohol can be selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylene glycol, pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, trimethylolpropane, mannitol, sorbitol, and mixtures thereof. Any rosin resin that satisfies the glass transition temperature requirement can be appropriately used in the present invention. A suitable rosin resin is Kraton Sylvatraxx 2097.

[0031] The softening point of the rosin resin may be greater than 50°C, preferably 70°C to 130°C, more preferably 90°C to 110°C, for example, 90°C, 95°C, 100°C, or 110°C, or any intermediate value.

[0032] 1 The aromaticity of the rosin-based resin, as measured by 1H NMR, may be greater than 1, preferably 3.5 to 9.5, and preferably 6.5.

[0033] The first hydrocarbon resin may be present in an amount of up to 30 phr, preferably 5 to 25 phr, for example 5 phr, 10 phr, 15 phr, 20 phr or 25 phr, or any intermediate value. The second hydrocarbon resin may be present in an amount of up to 70 phr, preferably 10 to 60 phr, more preferably 15 to 55 phr, for example 15 phr, 20 phr, 25 phr, 30 phr, 35 phr, 40 phr, 45 phr, 50 phr or 55 phr, or any intermediate value.

[0034] The inventors have discovered that interaction / synergistic effects of the resin system can be observed at high resin filling amounts. Therefore, the resin system may be present in amounts of 30-90 phr, preferably 35-80 phr, more preferably 40-70 phr, for example, 40 phr, 45 phr, 50 phr, 55 phr, 60 phr, 65 phr or 70 phr, or any intermediate value.

[0035] Elastomer The rubber composition optionally includes a functionalized diene elastomer. The diene elastomer is an elastomer derived at least partially (e.g., as a homopolymer or copolymer) from a diene monomer, i.e., a monomer-diene monomer having two carbon-carbon double bonds, which may or may not be conjugated. Examples of suitable diene elastomers include polybutadiene, natural rubber, synthetic polyisoprene, butadiene copolymer, isoprene copolymer, and mixtures thereof. The diene elastomer may be present in amounts of 10 to 80 phr, more preferably 20 to 65 phr, for example, 20 phr, 30 phr, 35 phr, 40 phr, 45 phr, 50 phr, 55 phr, 60 phr, or 65 phr. In a preferred embodiment, the diene elastomer is polybutadiene rubber. gThe temperature range may be -150°C to -75°C, preferably -120°C to -80°C, more preferably -110°C to -90°C, for example -110°C, -100°C, -95°C, or -90°C. The functional group of the diene elastomer is not particularly limited and may be one or more functional groups selected from the group consisting of alcohol, carboxyl, ester, amide, amine, imine, imide, nitrile, oxime, thiol, sulfide, sulfoxide, sulfone, sulfinic acid, sulfonic acid, sulfonic acid ester, thiocarboxylic acid, thioester, silane, alkoxysilane, aminosilane, and silanol.

[0036] The copolymer of styrene and butadiene may be a styrene-butadiene copolymer (abbreviated as SBR), and may be an emulsified SBR or eSBR (i.e., SBR prepared by emulsion polymerization), a solution SBR or sSBR (i.e., SBR prepared by solution polymerization), or a mixture of both. g The temperature range may be -90°C to -20°C, preferably -75°C to -40°C, preferably -65°C to -50°C, for example, -65°C, -60°C, -55°C, or -50°C. Those skilled in the art will know T g We recognize how the copolymer structure can be modified to adjust the required value. The copolymer of styrene and butadiene may exist in amounts of 10 to 90 phr, preferably 35 to 80 phr, for example, 35 phr, 40 phr, 45 phr, 50 phr, 55 phr, 60 phr, 65 phr, 70 phr, 75 phr or 80 phr, or any intermediate value.

[0037] The copolymer of styrene and butadiene may be functionalized with carboxyl groups, preferably terminal carboxyl groups. These carboxyl groups are represented by formula (I): (I) It may have a structure such as

[0038] [ka] During the ceremony, R1 and R2 are either the same or different, and each is independently a hydrogen, alkyl, alkoxy, cycloalkyl, cycloalkoxy, aryl, aryloxy, alkylaryl, alkylaryloxy, aralkyl, or aralkoxy radical, which may contain one or more heteroatoms, preferably one or more heteroatoms selected from the group consisting of O, N, S, and Si. R3 and R4 are either the same or different, and are independently hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl radicals, which may contain one or more heteroatoms, preferably one or more heteroatoms selected from the group consisting of O, N, S, and Si. A is a divalent organic radical that may be an alkylene radical; one or more heteroatoms selected from the group consisting of O, NR7, S, and SiR8R9; or an alkylene radical containing one or more heteroatoms, preferably one or more heteroatoms selected from the group consisting of O, NR7, S, and SiR8R9.

[0039] In equation (I), R1 and R2 are, independently, hydrogen, C1-C 12 Linear or branched alkyl, C2-C 12 Linear or branched alkenyls, C1-C 12 Linear or branched alkoxy, C3-C 12 Cycloalkyl, C2~C 12 Cycloalkoxy, C6~C 12 Aryl, C6~C 12 Aryloxy, C7~C 14 Arylalkyl, C7~C 14 Alkylaryl, C6~C 24 Alkylaryloxy, C5~C 24 Aralkil, or C6~C 24 It may be an aralkoxy radical. Preferably, R1 and R2 are each independently a C1-C6 linear or branched alkyl, a C2-C6 linear or branched alkenyl, a C1-C6 linear or branched alkoxy, or a C3-C12 Cycloalkyl, C2~C 12 Cycloalkoxy, or C6-C 12 It may be an aryl radical. Preferably, R1 and R2 are each independently a C1-C6 linear or branched alkyl, a C2-C6 linear or branched alkenyl, a C1-C6 linear or branched alkoxy, or a C6-C 12 They can be aryl radicals. Preferably, R1 and R2 can each be independently a C1-C3 linear or branched alkyl, a C2-C3 linear or branched alkenyl, a C1-C3 linear or branched alkoxy, or a C6 aryl radical. For example, R1 and R2 can each be independently a methyl, tert-butyl, propa-1-enyl, ethoxy, or phenyl radical. More preferably, R1 and R2 are methyl radicals.

[0040] R3 and R4 are independently hydrogen, C1~C 12 Linear or branched alkyl groups, C3-C 12 Cycloalkyl, C6~C 12 Aryl, C5~C 24 Aralkil, or C5~C 24 It may be an alkali radical. Preferably, R3 and R4 are each independently hydrogen, a C1-C6 linear or branched alkyl, a C2-C6 linear or branched alkenyl, a C1-C6 linear or branched alkoxy, or a C6-C 12 It may be an aryl radical. More preferably, R3 and R4 may each be independently a hydrogen or a methyl group. In certain embodiments, R3 / R4 and "A" together form a C6 aryl group.

[0041] "A" may independently be a substituted or unsubstituted C1-C6 linear alkyl radical; one or more heteroatoms selected from the group consisting of O, NR7, S, and SiR8R9; or a substituted or unsubstituted C1-C6 linear alkyl radical containing one or more heteroatoms selected from the group consisting of O, NR7, S, and SiR8R9. Preferably, "A" may independently be a substituted or unsubstituted C1-C3 linear alkyl group; one or more heteroatoms selected from the group consisting of O, NR7, S, and SiR8R9; or a substituted or unsubstituted C1-C3 linear alkyl radical containing one or more heteroatoms selected from the group consisting of O, NR7, S, and SiR8R9. When "A" is substituted, it may be a C1-C6 linear alkyl radical and a C6-C 12 It may be substituted with one or more selected from the group consisting of aryl radicals. Preferably, "A" may be substituted with a C1-C3 linear alkyl radical or a C6 aryl radical. More preferably, "A" may be substituted with a C1 radical. R7 may be hydrogen, a C1-C6 linear alkyl, for example, methyl or trimethylsilyl. R8 and R9 may independently be a C1-C6 linear alkyl, for example, methyl. Preferably, A is a C2 alkyl radical containing a sulfur atom. The structure of "A" as a C2 alkyl radical containing a sulfur atom is shown below.

[0042] [ka]

[0043] The carboxyl group is represented by formula (II): (II) It may exist as a carboxylate,

[0044] [ka] During the ceremony, R1 and R2 are defined above for equation (I), R3 and R4 are defined above for equation (I), A is defined above for equation (I), M is a metal or metalloid with a valency of 1 to 4, for example, Li, Na, K, Mg, Ca, Zn, Fe, Co, Ni, Al, Nd, Ti, Sn, Si, Zr, V, Mo, or W, and n is an integer between 1 and 4.

[0045] In the compound of formula (II), M may be Li and n may be 1.

[0046] The further definitions of R1, R2, R3, R4, R7, R8, and R9 in equation (II) are the same as the definitions above for equation (I).

[0047] Functionalized SBR can be obtained by reacting an SSBR copolymer with one or more functionalizing reagents in the form of silalactones. Silaractones are given by formula (III): (III) It may be a compound of,

[0048] [ka] During the ceremony, R1 and R2 are defined above for equation (I), R3 and R4 are as defined above for equation (I), and A is defined above for equation (I).

[0049] Further definitions of R1, R2, R3, R4, R7, R8, and R9 in equation (III) are as described above for equation (I).

[0050] Advantageously, the silalactone of formula (III) is 2,2-dimethyl-1-oxa-2-silacyclohexane-6-one, 2,2,4-trimethyl-1-oxa-2-silacyclohexane-6-one, 2,2,5-trimethyl-1-oxa-2-silacyclohexane-6-one, 2,2,4,5-tetramethyl-1-oxa-2-silacyclohexane-6-one, 2,2-diethyl-1-oxa-2-silacyclohexane-8-one, 2,2-diethoxy-1-oxa-2-silacyclohexane-6-one, 2,2-dimethyl-1,4 -Dioxa-2-silacyclohexane-6-one, 2,2,5-trimethyl-1,4-dioxa-2-silacyclohexane-6-one, 2,2,3,3-tetramethyl-1,4-dioxa-2-silacyclohexane-6-one, 2,2-dimethyl-1-oxa-4-thia-2-silacyclohexane-6-one, 2,2-diethyl-1-oxa-4-thia-2-silacyclohexane-6-one, 2,2-diphenyl-1-oxa-4-thia-2-silacyclonexan-6-one, 2-methyl-2- Ethenyl-1-oxa-4-thia-2-silacyclohexane-6-one, 2,2,5-trimethyl-1-oxa-4-thia-2-silacyclohexane-6-one, 2,2-dimethyl-1-oxa-4-aza-2-silacyclohexane-6-one, 2,2,4-trimethyl-1-oxa-4-aza-2-silacyclohexane-6-one, 2,4-dimethyl-2-phenyl-1-oxa-4-aza-2-silacyclohexane-6-one, 2,2-dimethyl-4-trimethylsilyl-1-oxa-4-aza-2-silacyclohexane-8- ONE, 2,2-diethoxy-4-methyl-1-oxa-4-aza-2-silacyclohexane-6-ONE, 2,2,4,4-tetramethyl-1-oxa-2,4-disilacyclohexane-8-ONE, 3,4-dihydro-3,3-dimethyl-1H-2,3-benzoxacillin-1-ONE, 2,2-dimethyl-1-oxa-2-silacyclopentan-5-ONE, 2,2,3-trimethyl-1-oxa-2-silacyclopenten-5-ONE, 2,2-dimethyl-4-phenyl-1-oxa-2-silacyclopentan-5-ONE, 2,2,It may be one or more selected from the group consisting of 4-(tert-butyl)-1-oxa-2-silacyclopentan-5-one, 2-methyl-2-(2-propen-1-yl)-1-oxa-2-silacyclopentan-5-one, 1,1-dimethyl-2,1-benzoxasilol-3(1H)-one, and 2,2-dimethyl-1-oxa-2-silacycloheptan-7-one. Preferably, the silalactone of formula (III) is 2,2-dimethyl-1-oxa-4-thia-2-silacyclohexane-6-one. The structure of 2,2-dimethyl-1-oxa-4-thia-2-silacyclohexane-6-one is shown below.

[0051] [ka]

[0052] The carboxyl group is represented by formula (V): (V) It may be bonded to the SBR copolymer via one or more divalent structural elements.

[0053] [ka] During the ceremony, n is an integer between 3 and 6. R5 and R6 are either the same or different, and each is independently a hydrogen, alkyl, cycloalkyl, aryl, alkalil, or aralkyl radical. These may contain one or more heteroatoms, preferably one or more heteroatoms selected from the group consisting of O, N, S, or Si.

[0054] When divalent structural elements are present, the SBR copolymer is bonded at the silicon ends of the divalent structural elements according to the following:

[0055] [ka]

[0056] The silane-containing carboxyl group of formula (I) or (II) is bonded to the oxygen terminus of the divalent structural element of formula (V) when a divalent structural element is present.

[0057] The divalent structural element of equation (V) is given by equation (IV): (IV) It may be derived from cyclosiloxanes such as cyclosiloxanes,

[0058] [ka] During the ceremony, n is defined above for equation (V), R5 and R6 are defined above for equation (V).

[0059] R5 and R6 are independently hydrogen, C1~C 12 Linear or branched alkyl groups, C3-C 12 Cycloalkyl, C6~C 12 Aryl, C7~C 14 Aralkil, or C7~C 14 It may be an alkali radical. Preferably, R5 and R6 may each be independently a C1-C6 linear or branched alkyl group, preferably a C1-C3 linear alkyl group, and more preferably a methyl radical.

[0060] The divalent structural element of formula (V) may be derived from one or more selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. Preferably, the divalent structural element may be derived from hexamethylcyclotrisiloxane.

[0061] It is particularly advantageous that the SBR copolymer is terminated with carboxyl groups derived from 2,2-dimethyl-1-oxa-4-thia-2-silacyclohexane-6-one, which are bonded to the polymer via divalent structural elements derived from hexamethylcyclotrisiloxane. In this embodiment, the carboxyl groups of formula (I) (having R1, R2, R3, and R4 as methyl radicals and "A" as a C2 alkyl radical containing the above-mentioned S atom) are bonded to the copolymer by divalent structural elements of formula (V), where R5 and R6 are methyl radicals and n is 3.

[0062] The SBR copolymer may have a styrene content of 1% to 20% by weight, preferably 5% to 15% by weight, more preferably 8% to 10% by weight, for example, 8% by weight, 9% by weight, or 10% by weight. The SBR copolymer may have a vinyl content of 10% to 50% by weight, preferably 20% to 40% by weight, more preferably 28% to 38% by weight, for example, 28% by weight, 29% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, 35% by weight, 36% by weight, 37% by weight, or 38% by weight of the SBR copolymer.

[0063] SBR copolymers may have an average molar mass (number mean, Mn) of 10,000 to 2,000,000 g / mol, preferably 100,000 to 1,000,000 g / mol.

[0064] SBR copolymers may have Mooney viscosities [ML 1+4 (100℃)] of 10-200 Mooney units, e.g., 30-150 Mooney units, 40-90 Mooney units, 50-60 Mooney units, e.g., 50 Mooney units, 51 Mooney units, 52 Mooney units, 53 Mooney units, 54 Mooney units, 55 Mooney units, 56 Mooney units, 57 Mooney units, 58 Mooney units, 59 Mooney units, and 60 Mooney units.

[0065] The SBR copolymer may be spread with an expansive oil such that the spread SBR copolymer contains 1 to 30 phr, preferably 1 to 10 phr of the expansive oil. The expansive oil may be one or more selected from the group consisting of DAE (Distillate Aromatic Extract), Tdae (Treated Distillate Aromatic Extract), MES (Mild Extraction Solvate), RAE (Residual Aromatic Extract), TRAE (Treated Residual Aromatic Extract), naphthenic oils, heavy naphthenic oils, paraffinic oils, vegetable oils such as coconut oil, synthetic oils such as alkylbenzene oils, and castor oil. Preferably, the SBR copolymer is spread with an aromatic oil such as treated distillate aromatic extract oil (Tdae) such that the spread SBR copolymer contains 2.5 to 7.5 phr of treated distillate aromatic extract oil.

[0066] The synthesis of carboxyl-terminated sSBR copolymers and compounds of formulas (I) to (V) above is discussed in detail, for example, in International Publication No. 2014 / 173706(A1).

[0067] Filler components The rubber composition may further contain an inorganic reinforcing filler, which may include a silica-based mineral filler and / or an aluminum-based mineral filler. The inventors have found that a higher amount of inorganic reinforcing filler may be beneficial in providing the technical effects of the present invention. Preferably, the silica-based filler is (SiO2). Suitable additional silaceous fillers include precipitated amorphous silica, wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), fumed silica, calcium silicate, aluminum silicate, magnesium silicate (e.g., Mg2SiO4, MgSiO3), calcium magnesium silicate (CaMgSiO4), and calcium aluminum silicate (e.g., Al2O3, CaO2SiO2). Preferably, the aluminum-based filler is alumina (Al2O3) or aluminum hydroxide (e.g., Al(OH)3). In preferred embodiments, the inorganic reinforcing filler is a combination of silica and aluminum hydroxide (Al(OH)3). The total amount of inorganic reinforcing filler (e.g., silica) may be at least 70 phr, preferably 80 to 120 phr, for example, 80 phr, 90 phr, 100 phr, 110 phr, or 120 phr.

[0068] The rubber composition may include additional fillers (i.e., fillers added to the inorganic reinforcing fillers), such as carbon black. The carbon black may be furnace black, channel black, and lamp black. For example, the carbon black may be one or more selected from the group consisting of super abrasion furnace (SAF) black, high abrasion furnace (HAF) black, fast extrusion furnace (FEF) black, fine furnace (FF) black, intermediate super abrasion furnace (ISAF) black, semi-reinforcing furnace (SRF) black, medium processing channel black, hard processing channel black, and conductive channel black. Another carbon black that can be used is acetylene black. The carbon black may be in pelletized form or in unpelleted cotton-like masses. A specific example of carbon black in the rubber composition of the present invention is CORAX® N234 by Orion Engineered Carbons. The amount of carbon black contained in the rubber composition of the present invention is not particularly limited, but may be 0.1 to 20 parts by weight of the rubber component, for example, 5 to 15 phr, for example, 5 phr, 6 phr, 7 phr, 8 phr, 9 phr, 10 phr, 11 phr, 12 phr, 13 phr, 14 phr, or 15 phr.

[0069] Additional ingredients The rubber composition is suitable for use at standard ambient temperatures and pressures (25°C, 10°C). 5The mixture may further contain one or more oils that are liquid at Pa. These are sometimes called liquid plasticizers. These oils may be one or more selected from the group consisting of, for example, liquid diene polymers, polyolefin oils, naphthenic oils, paraffinic oils, DAE oils, MES (Medium Extracted Solvate) oils, TDAE (Treated Distillate Aromatic Extract) oils, RAE oils (Residual Aromatic Extract oils), TRAE oils (Treated Residual Aromatic Extract) and SRAE oils (Safety Residual Aromatic Extract oils), mineral oils, vegetable oils, ether plasticizers, ester plasticizers, preferably oleic acid esters such as octyl oleate or 2-ethylhexyl oleate, phosphate plasticizers, sulfonic acid plasticizers, and mixtures thereof. In a preferred embodiment, the oil may be a combination of TDAE oil and octyl oleate. The oil may be present in an amount of at least 1 phr, preferably 5 to 40 phr, more preferably 7 to 15 phr, for example, 7 phr, 8 phr, 9 phr, 10 phr, 11 phr, 12 phr, 13 phr, 14 phr, or 15 phr.

[0070] In addition to the components described above, the rubber composition may include additional components that a person skilled in the art might consider including to prepare a rubber composition suitable for the preparation of pneumatic tires. These include, for example, vulcanizing agents (e.g., sulfur), vulcanization accelerators, vulcanization accelerators, silane coupling agents, degradation inhibitors (e.g., antioxidants or ozone degradation inhibitors), waxes, and processing agents.

[0071] In a particularly preferred embodiment, the rubber composition is T g Polybutadiene rubber, which has the properties of and is present in an amount of 20-65 phr, T gA copolymer of styrene and butadiene, optionally functionalized with terminal carboxyl groups, is present in an amount of 35-80 phr, A resin system present in an amount of 40-70 phr, T 55℃~80℃ g A terpene-based resin having the following, present in an amount of 5 to 25 phr, a first hydrocarbon resin, and It is a rosin-based resin, and the temperature range is 40°C to 60°C. g A second hydrocarbon resin having and present in an amount of 15-55 phr, The resin system includes (for example, consists of) reinforcing inorganic fillers present in an amount of 80 to 120 phr, The ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin per 100 parts (phr) of rubber is 0.9:1 to 5:1.

[0072] When preparing the rubber composition of the present invention, the method of combining each component is not limited, and any method known to those skilled in the art may be used. For example, all component materials may be compounded and kneaded at once, or they may be compounded and kneaded in multiple stages. For compounding and kneading, a kneader such as a roll kneader, an internal mixer, or a Banbury mixer can be used. To form the rubber composition into a sheet or strip, any known molding machine such as an extruder or a press molding machine can be used. The vulcanization conditions for curing the above rubber composition are not limited, and any conditions known to those skilled in the art may be used. However, typically, vulcanization conditions of 140 to 180°C for 5 to 120 minutes are employed.

[0073] Unless otherwise specified, the amounts of components in the rubber composition of the present invention are provided in parts per 100 parts by weight (phr), meaning parts per 100 parts by weight of elastomer (or total elastomer if several elastomers are present). The term "rubber composition" may be used interchangeably with the term "rubber compound."

[0074] pneumatic tires In a further embodiment, the present invention relates to a pneumatic tire. The pneumatic tire is not particularly limited and may be any tire used, for example, in passenger cars such as automobiles, motorcycles, or commercial vehicles. The pneumatic tire may be suitable for any type of climate, weather, or road conditions and may be, for example, a summer tire, a winter tire, a snow tire, an all-season tire, or a high-performance tire. The inventors have found that the interaction / synergistic effects of the rubber composition of the present invention make it particularly suitable for use in tires having good winter performance.

[0075] Taking the above into consideration, the present invention relates to a pneumatic tire containing the rubber composition of the present invention and / or a pneumatic tire prepared from the rubber composition of the present invention.

[0076] In a further embodiment, the present invention relates to the use of rubber compositions in the manufacture of pneumatic tires.

[0077] The parts of a tire in which the rubber composition of the present invention is used are not particularly limited and can be appropriately selected depending on the intended purpose. For example, the rubber composition can be used in the tread, base tread, sidewall, side reinforcement rubber, bead filler, etc. In particular, the rubber composition is advantageously used in tread components.

[0078] Regarding the manufacturing method of the tire, any method known to those skilled in the art can be used. For example, a carcass layer, a belt layer, a tread layer, etc., formed from at least one of the components commonly used in tire manufacturing, such as an unvulcanized rubber composition and a cord, are sequentially laminated on a tire molding drum, and then the drum is removed to obtain a green tire. Next, the green tire is heated and vulcanized according to a conventional method to produce the desired tire. [Examples]

[0079] The present invention will now be described by the following non-limiting embodiments.

[0080] Measurement method Glass transition temperature (T g ) According to standard ASTM D3418 (1999), the glass transition temperature (T) was determined by DSC (Differential Scanning Calorimetry). g ) was measured.

[0081] Pain effect The Payne effect was calculated from the dynamic properties of the compound measured in stress / strain tests at room temperature according to the ISO 4664 standard.

[0082] Mooney viscosity Mooney viscosity was measured for unprocessed functionalized or unfunctionalized polymers according to the ASTM D1646 standard.

[0083] Modulus of elasticity (E') The modulus of elasticity (E') is used to evaluate grip performance. Dynamic physical tests were conducted to determine E' at 30°C and -20°C according to the ISO 4664 standard.

[0084] Loss factor (tanδ) Rolling resistance and wet traction are evaluated using loss coefficients (tangent δ or tanδ) at different temperatures. Tanδ at lower temperatures is an indicator of wet traction. Therefore, tanδ at 60°C is an indicator of rolling resistance (RR). Dynamic physical tests were conducted to determine tanδ according to ISO 4664 standard.

[0085] General method The tire compound was prepared according to the following general method. The following components were blended in the amounts listed in Table 1 below. All values ​​in Table 1 are expressed in phr. Table 2 shows the measurements of various mechanical properties performed on test specimens of tire treads prepared using the compositions in Table 1.

[0086] component Elastomer: Having terminal carboxyl groups, T gThe functionalized solution of styrene-butadiene rubber (prepared using the method described in International Publication No. 2014 / 173706(A1)) at -60°C (SBR) T g Butadiene rubber (BR) (Europrene® Neocis BR 40) at -105℃ Silica: Silica (STD-SiO2) (Ultrasil VN3)

[0087] Hydrocarbon resins: T g A terpene resin (Kraton Silvatraxx 8115) with a temperature of 66°C, an aromaticity of 1, and polarity of 0. T g A rosin-based resin (Kraton Silvatraxx 2097) with a temperature of 49°C, an aromaticity of 6.5, and a polarity of 15.

[0088] Further additives: Recycled rubber Carbon Black (Corax® N234) Silane (Evonik Industries AG Si 69 (registered trademark)) Paraffin wax MES oil Processed distilled aromatic extract (TDAE) sulfur 1,3-Diphenylguanidine (DPG) Dibenzothiadyl disulfide (MBTS) N-cyclohexyl-2-benzothiadylsulfenamide (CBS) Zinc oxide (ZnO) Zinc salt of high MW fatty acids (Aktiplast® PP) Stearic acid.

[0089] [Table 1]

[0090] [Table 2]

[0091] Figure 1 shows E'(30°) at low T g This compares to the elastomer content and shows that when the ratio of rosin resin to terpene resin is greater than 0.2:1, an additive / synergistic effect is observed where E'(30°), an indicator of dry balance / handling, increases as the amount of butadiene rubber increases. When the ratio of rosin resin to terpene resin is outside this range, E'(30°) decreases as the amount of butadiene rubber increases.

[0092] Figure 2 shows the E'(30°) vs. Tandelta(0°) data from Table 2. E'(30°) is an indicator of dry balance / handling in a tire, and Tandelta(0°) is an indicator of wet balance / handling. Figure 1 shows high-butadiene rubber (and therefore low T g Regarding the ) system, it is shown that the resin system of the present invention optimizes the balance between wet balance / handling and dry balance / handling. Low T g The system is more suitable for winter / snowy conditions, and therefore, the composition of the present invention balances wet and dry performance and has excellent winter performance.

Claims

1. A rubber composition for pneumatic tires, Glass transition temperature (T) between -130°C and -30°C ｇ A optionally functionalized diene elastomer having, T ｇ A copolymer of optionally functionalized styrene and butadiene having, A resin system present in an amount of at least 30 phr, T ｇ A first hydrocarbon resin having and T ｇ A resin system comprising a second hydrocarbon resin having, A rubber composition in which the first hydrocarbon resin and the second hydrocarbon resin are different, and the ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin on a part-by-part (phr) basis per 100 parts of rubber is greater than 0.2:

1.

2. The rubber composition according to claim 1, wherein the first hydrocarbon resin and the second hydrocarbon resin have different glass transition temperatures, preferably the first hydrocarbon resin has a higher glass transition temperature than the second hydrocarbon resin, and more preferably the first hydrocarbon resin has a glass transition temperature 10°C to 40°C higher than the second hydrocarbon resin.

3. The rubber composition according to claim 1 or 2, wherein the first hydrocarbon resin and the second hydrocarbon resin have different aromatic degrees, preferably the first hydrocarbon resin has a lower aromatic degree than the second hydrocarbon resin, and more preferably the aromatic degree of the first hydrocarbon resin is 1 to 10% lower than the aromatic degree of the second hydrocarbon resin.

4. The rubber composition according to any one of claims 1 to 3, wherein the ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin on a PHR basis is 0.3:1 to 10:1, preferably 0.5:1 to 8:1, and more preferably 0.9:1 to 5:

1.

5. The first hydrocarbon resin is heated to a temperature of 50°C to 90°C, preferably 55°C to 80°C. ｇ A rubber composition according to any one of claims 1 to 4, having the following characteristics.

6. The second hydrocarbon resin is heated to a temperature of 20°C to 80°C, preferably 30°C to 70°C, more preferably 40°C to 60°C. ｇ A rubber composition according to any one of claims 1 to 5, having the following characteristics.

7. The rubber composition according to any one of claims 1 to 6, wherein the first hydrocarbon resin comprises a terpene resin.

8. The rubber composition according to any one of claims 1 to 7, wherein the second hydrocarbon resin comprises a rosin-based resin.

9. The rubber composition according to any one of claims 1 to 8, wherein the first hydrocarbon is present in an amount of up to 30 phr, preferably 5 to 25 phr.

10. The rubber composition according to any one of claims 1 to 9, wherein the second hydrocarbon resin is present in an amount of up to 70 phr, preferably 10 to 60 phr, and more preferably 15 to 55 phr.

11. The rubber composition according to any one of claims 1 to 10, wherein the resin system is present in an amount of 30 to 90 phr, preferably 35 to 80 phr, and more preferably 40 to 70 phr.

12. The rubber composition according to any one of claims 1 to 11, wherein the diene elastomer is present in an amount of 10 to 80 phr, preferably 20 to 65 phr.

13. The rubber composition according to any one of claims 1 to 12, wherein the diene elastomer is polybutadiene rubber.

14. The T of the aforementioned polybutadiene rubber ｇ The rubber composition according to claim 13, wherein the temperature range is -120°C to -80°C, preferably -110°C to -90°C.

15. The T of the styrene-butadiene copolymer ｇ The rubber composition according to any one of claims 1 to 14, wherein the temperature range is -75°C to -40°C, preferably -65°C to -50°C.

16. The rubber composition according to any one of claims 1 to 15, wherein the copolymer of styrene and butadiene is present in an amount of 10 to 90 phr, preferably 35 to 80 phr.

17. The rubber composition according to any one of claims 1 to 16, wherein the copolymer of styrene and butadiene is functionalized with carboxyl groups, preferably terminal carboxyl groups.

18. The rubber composition according to claim 17, wherein the carboxyl group is of formula (I): (I) It is the basis of, 【Chemistry 1】 During the ceremony, R １ and R ２ are the same or different and each independently is a hydrogen, alkyl, alkoxy, cycloalkyl, cycloalkoxy, aryl, aryloxy, alkylaryl, alkylaryloxy, aralkyl, or aralkoxy radical, which may contain one or more heteroatoms, preferably, the heteroatom is one or more selected from the group consisting of O, N, S, and Si, R ３ and R ４ However, these are either the same or different, and each is independently a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl radical, which may contain one or more heteroatoms, preferably one or more heteroatoms selected from the group consisting of O, N, S, and Si. A is a divalent organic radical that may be an alkyl radical; O, NR ７ , S, and SiR ８ R ９ One or more heteroatoms selected from the group consisting of; or an alkyl radical containing one or more heteroatoms, preferably the heteroatoms are O, NR ７ , S, and SiR ８ R ９ One or more selected from the group consisting of R ７ However, hydrogen, C １ ~C ６ Linear alkyl, preferably methyl, or trimethylsilyl, R ８ and R ９ However, independently, C １ ~C ６ A rubber composition comprising a linear alkyl group, preferably a methyl group.

19. The rubber composition according to claim 17 or 18, wherein the carboxyl group is of formula (V): (V) It is bonded to the copolymer of styrene and butadiene via one or more divalent structural elements, 【Chemistry 2】 Preferably, the divalent structural element is of formula (IV): (IV) It is derived from cyclosiloxane, 【Transformation 3】 During the ceremony, n is an integer between 3 and 6. R ５ , R ６ A rubber composition wherein the elements are the same or different, and each is independently a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl radical, which may contain one or more heteroatoms, preferably the heteroatom being O, N, S, or Si, and more preferably the divalent structural element is derived from one or more cyclosiloxanes selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane.

20. The rubber composition according to any one of claims 1 to 19, further comprising an inorganic reinforcing filler in an amount of at least 70 phr, preferably 80 to 120 phr.

21. The rubber composition according to any one of claims 1 to 20, wherein the inorganic reinforcing filler contains silica.

22. A rubber composition according to any one of claims 1 to 21, T ｇ Polybutadiene rubber having the properties of and present in an amount of 20 to 65 phr, T at -75°C to -40°C ｇ A copolymer of styrene and butadiene, optionally functionalized with terminal carboxyl groups, is present in an amount of 35 to 80 phr, A resin system present in an amount of 40 to 70 phr, 55°C to 80°C ｇ A first hydrocarbon resin containing a terpene-based resin having the following, present in an amount of 5 to 25 phr, and T 40℃~60℃ ｇ A second hydrocarbon resin, comprising a rosin-based resin having a second hydrocarbon resin present in an amount of 15 to 55 phr, The resin system optionally includes (for example, consists of) reinforcing inorganic fillers present in an amount of 80 to 120 phr, A rubber composition in which the ratio of the amount of the second hydrocarbon resin to the amount of the first hydrocarbon resin, based on parts per 100 parts (phr), is 0.9:1 to 5:

1.

23. Use of the rubber composition according to any one of claims 1 to 22 in the manufacture of a pneumatic tire.

24. A pneumatic tire comprising the rubber composition according to any one of claims 1 to 22.

25. A pneumatic tire prepared from the rubber composition described in any one of claims 1 to 22.

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