Rubber composition for pneumatic tires and pneumatic tires manufactured therefrom

Abstract

A rubber composition for pneumatic tires comprising a polymer having a low glass transition temperature and a hydrocarbon resin blend, and a pneumatic tire manufactured therefrom.

Description

[Technical Field]

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

[0002] Pneumatic tires for automobiles can be designed to perform well under specific conditions. For example, winter tires remain flexible at low temperatures (e.g., below 7°C) and thus provide traction in icy and snowy conditions. Such tires are known, for example, from European Patent Application Publication No. 2643400(A1). They are not suitable for use at higher temperatures, as the softer compound wears down more easily, shortening the tire's lifespan. Wet performance can also be reduced. Summer tires are designed for high performance in warm conditions and can enhance cornering and braking capabilities while remaining suitable for wet conditions. This balance can be achieved by using a harder compound, i.e., a compound that softens at higher temperatures than winter tire compounds. However, grip at low temperatures is consequently reduced, and these tires are not suitable for winter conditions.

[0003] Manufacturing pneumatic tires that perform well under all conditions presents a special challenge for tire designers. They must offer a long tread life while providing balanced performance suitable for various driving conditions, including wet, dry, and winter conditions on various types of surfaces. 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 Payne effect and the ratio of loss to storage elastic modulus (tan δ)). In particular, it may be an issue to prepare a tire having good winter performance that maintains good wet performance and dry performance. Such a pneumatic tire typically has a low T to provide the required grip at low temperatures g using an elastomer having, which needs to be balanced with other factors (such as the filling 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 have to 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 WO 2022 / 130201 (A1). However, in the art, there is still a need to provide pneumatic tires that provide balanced performance over a variety of operating conditions including good winter performance.

[0004] The present invention aims to provide a solution to one or more of the problems identified above.

Summary of the Invention

[0005] The inventors have found that a tire having a good balance between wet performance, rolling resistance and dry handling and good winter performance can be prepared using a rubber composition comprising a combination of an elastomer having a low T g and a resin present in a specific ratio.

[0006] Viewed from a first aspect, the present invention - a randomly functionalized copolymer of styrene and butadiene (SBR) having a glass transition temperature (T g ) of -90 °C to -20 °C; - optionally, a diene elastomer having a T g of -130 °C to -30 °C; a first hydrocarbon resin having a T g of at least 50 °C; and T of at least 20 °C g A second hydrocarbon resin having; a resin system present in an amount of at least 30 phr; a rubber composition for a pneumatic tire comprising The first and second hydrocarbon resins are different, and the ratio of the amount of the first hydrocarbon resin to the amount of the second hydrocarbon resin is less than 1.5:1 parts (phr) per 100 parts of rubber, relating to a rubber composition for a pneumatic tire.

[0007] Viewed from a second aspect, the present invention relates to the use of the above rubber composition in the manufacture of a pneumatic tire.

[0008] Viewed from a third aspect, the present invention relates to a pneumatic tire comprising the above rubber composition.

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

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

Brief Description of the Drawings

[0011] [Figure 1A] Shows how the modulus of elasticity at 30 °C changes as the ratio of the first hydrocarbon resin to the second hydrocarbon resin changes. [Figure 1B] Shows how the modulus of elasticity at -20 °C changes as the ratio of the first hydrocarbon resin to the second hydrocarbon resin changes. [Figure 2] Shows a comparison between tan δ at 0 °C (an index of wet handling) and the modulus of elasticity at 30 °C (an index of dry handling). [Figure 3] Shows a comparison between tan δ at 60 °C (an index of rolling resistance) and the modulus of elasticity at -20 °C (an index of snow handling).

Modes for Carrying Out the Invention

[0012] The present invention has a low T gThe present invention is based in part on the inventors' discovery that for rubber compositions containing an elastomer (e.g., below 0 °C), certain resins increase the dispersion of fillers in the composition (measured by the Payne effect), thus reducing the stiffness of the compound, while other resins reduce the filler dispersion and increase the stiffness of the compound. When these resins are present in certain ratios, interactions and / or synergistic effects are observed on the properties of tires manufactured from the compound, including the modulus at 30 °C (an indicator of dry handling), the modulus at -20 °C (an indicator of winter handling), and tan δ at 0 °C (an indicator of wet performance). As a result, the compositions of the present invention are well-suited for the preparation of tires having balanced performance, particularly tires having good winter performance.

[0013] According to the above, in one aspect, the present invention provides - An optionally functionalized copolymer of styrene and butadiene (SBR) having a glass transition temperature (Tg) of -90 °C to -20 °C; g ) - Optionally, a diene elastomer having a Tg of -130 °C to -30 °C; g - A first hydrocarbon resin having a Tg of at least 50 °C; and g - A second hydrocarbon resin having a Tg of at least 20 °C; a resin system present in an amount of at least 30 phr; a rubber composition for a pneumatic tire, g where the first and second hydrocarbon resins are different and the ratio of the amount of the first hydrocarbon resin to the amount of the second hydrocarbon resin is less than 1.5:1 parts per hundred parts of rubber (phr), providing a rubber composition for a pneumatic tire.

[0014] Hydrocarbon resin The resin is at standard ambient temperature and pressure (25 °C, 10 5Hydrocarbon resins are solid or highly viscous compounds at Pa. Hydrocarbon resins are essentially based on carbon and hydrogen, but may also contain other types of atoms. They can be aliphatic, alicyclic, aromatic, hydrogenated aromatic, and aliphatic / aromatic, i.e., based on aliphatic and / or aromatic monomers. Hydrocarbon resins can also be classified as thermoplastic resins in the sense that they soften upon heating and are therefore moldable.

[0015] Examples of such hydrocarbon resins include those selected from the group consisting of 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, α-methylstyrene homopolymer or copolymer resins, and combinations thereof. Any hydrocarbon resin that satisfies the glass transition temperature requirement can be used in conjunction with the present invention.

[0016] In the present invention, the first hydrocarbon resin and the second hydrocarbon resin may differ in their structural characteristics and / or measurable properties. For example, the hydrocarbon resins may be from different classes of resins, such as terpenes and rosin or partially hydrogenated C5 and rosin. Additionally or alternatively, they may differ in properties such as glass transition temperature, softening point, aromaticity and / or polarity.

[0017] The glass transition temperature of the first hydrocarbon resin may be 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 the material transitions from a hard, relatively brittle "glassy" state to a viscous or rubbery state as the temperature increases. 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 lower aromaticity than the second hydrocarbon resin. The aromaticity value as defined herein is the content of aromatic protons having a chemical shift of 6.5 to 8.5 ppm. 1 The aromaticity is measured by 1H NMR. 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, and may be, 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 composition of the present invention can improve filler dispersion (and thus reduce stiffness), while decreasing the ratio of the first hydrocarbon resin to the second hydrocarbon resin reduces filler dispersion and increases stiffness. When the first and second hydrocarbon resins are present in a specific ratio range, interactions and / or synergistic effects are observed in the properties of tires manufactured from the compound, including the modulus of elasticity at 30°C (an indicator of dry handling), the modulus of elasticity at -20°C (an indicator of winter handling), and tanδ at 0°C (an indicator of wet performance). As a result, the composition of the present invention is well-suited for preparing tires with balanced performance, particularly tires with good winter performance.

[0020] In preferred embodiments, the ratio of the amount of the first hydrocarbon resin to the amount of the second hydrocarbon resin may be 0.05:1 to 1.45:1 on a phr basis, preferably 0.1:1 to 1:1, more preferably 0.15:1 to 0.9:1, for example 0.15:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, or 0.9:1. The inventors have found that the interaction / synergistic effect is particularly pronounced when the resin ratios are within these ranges.

[0021] The first hydrocarbon resin may be present in amounts up to 30 phr, preferably 5 to 25 phr, more preferably 7 to 22 phr, for example 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22 phr. The second hydrocarbon resin may be present in amounts up to 70 phr, preferably 20 to 65 phr, more preferably 25 to 60 phr, more preferably 30 to 55 phr, for example 30, 35, 40, 45, 50, or 55 phr and any intermediate value. The first and second hydrocarbon resins may be present in any combination of these amounts.

[0022] 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, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 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.

[0023] The second hydrocarbon resin is heated at 20°C to 80°C, preferably 30°C to 70°C, more preferably 40°C to 60°C, for example, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 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.

[0024] The first hydrocarbon resin may include (for example, consist of) a terpene resin. The terpene resin may include a resin that is a mixture of terpene monomers (referred to herein as a heteropolymer), or a resin that is a terpene homopolymer, the terpene homopolymer may be an α-pinene homopolymer. These may be, 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 phenol resins (i.e., resins prepared from terpenes and phenol compounds). The basic molecular formula of terpenes is (C5H8) nIt is a multiple of n, 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 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 monomer. 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. In a preferred embodiment, the terpene resin contains a mixture of α-pinene and β-pinene monomer, with limonene present in an amount of less than 10% by weight. In this invention, any terpene resin that satisfies the glass transition temperature requirement can be used. A suitable terpene resin is Kraton Sylvatraxx 8115.

[0025] The softening point of terpene resins may be 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 flexibility, as measured using a ring and ball apparatus according to ISO 4625.

[0026] 1 The aromaticity of the terpene resin, as measured by 1H NMR, may be greater than 0, preferably 0.1 to 5, and preferably 1.

[0027] Additionally or alternatively, 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).

[0028] 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 exclude 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.

[0029] 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.

[0030] 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.

[0031] The aromaticity of the partially hydrogenated C5 resin, as measured by NMR, may be greater than 0, preferably 0.1 to 5, and preferably 2.

[0032] The second hydrocarbon resin may include (for example, 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 carboxylic acid group. Rosin is a solid resin material that occurs naturally in pine trees. There are three main sources of rosin: (1) gum rosin from oleoresin extrusions of living pine trees; (2) wood rosin from oleoresin contained in aged stumps; and (3) tall oil rosin from 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 may be 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. In the present invention, any rosin resin that satisfies the glass transition temperature requirement can be suitably used. A suitable rosin resin is Kraton Sylvatraxx 2097.

[0033] The softening point of the rosin-based resin is 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.

[0034] 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.

[0035] The inventors have discovered that the interaction / synergistic effect of the resin system can be observed at high resin addition 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, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, or 70 phr.

[0036] Elastomer The copolymer of styrene and butadiene may be styrene-butadiene copolymer (abbreviated as SBR), and may be emulsion SBR or eSBR (i.e., SBR prepared by emulsion polymerization), solution SBR or sSBR (i.e., SBR prepared by solution polymerization), or a mixture thereof. 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 know how the copolymer structure can be modified to adjust the required value. The copolymer of styrene and butadiene may exist in amounts of 40-90 phr, preferably 45-80 phr, for example, 45, 50, 55, 60, 65, 70, 75, or 80 phr.

[0037] The copolymer of styrene and butadiene may be functionalized with carboxyl groups, preferably terminal carboxyl groups. These carboxyl groups may have the structure of formula (I).

[0038] [ka] During the ceremony, R1 and R2 may be the same or different, and each may independently be 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 may be 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 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 alkenyl, 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-C 12 Cycloalkyl, C2~C 12Cycloalkoxy, 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 may be aryl radicals. Preferably, R1 and R2 may 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 may 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, 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 radical. In certain embodiments, R3 / R4 and "A" together form a C6 aryl.

[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 radical; 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. If "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, such as methyl or trimethylsilyl. R8 and R9 may independently be a C1-C6 linear alkyl, such as 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 can represent the carboxylate of formula (II),

[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, such as Li, Na, K, Mg, Ca, Zn, Fe, Co, Ni, Al, Nd, Ti, Sn, Si, Zr, V, Mo, or W. n is an integer between 1 and 4.

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

[0046] The further definitions of R1, R2, R3, R4, R7, R8, and R9 in equation (II) are the same as the definitions given 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 a silalactone. The silalactone may be a compound of formula (III),

[0048] [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).

[0049] Further definitions of R1, R2, R3, R4, R7, R8, and R9 in equation (III) are as defined 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-Thi-2-Silacyclohexane-6-one, 2,2-Diethyl-1-Oxa-4-Thi-2-Silacyclohexane-6-one, 2,2-Diphenyl-1-Oxa-4-Thi-2-Silacyclooxane-6-one, 2-Methyl-2-Ethenyl-1-Ox S-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 may be bonded to the SBR copolymer via one or more divalent structural elements of formula (V),

[0053] [ka] During the ceremony, n is an integer between 3 and 6. R5 and R6 are the same or different, and independently each is a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl radical. This 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 binds to the silicon terminus of the divalent structural elements as shown below.

[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) if a divalent structural element is present.

[0057] The divalent structural element of formula (V) may be derived from cyclic siloxanes such as the cyclic siloxane of formula (IV).

[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, C3-C 12 Cycloalkyl, C6~C 12 Aryl, C7~C 14 Aralquil 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 is 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) (where R1, R2, R3, and R4 are methyl radicals and "A" is the above-mentioned S atom-containing C2 alkyl radical) 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 of the SBR copolymer. 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 to 200 Mooney units, for example 30 to 150 Mooney units, 40 to 90 Mooney units, 50 to 60 Mooney units, for example 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 Mooney units.

[0065] The SBR copolymer may be extended with an extender oil such that the extended SBR copolymer contains 1 to 30 phr, preferably 1 to 10 phr of the extender oil. The extender oil may be one or more selected from the group consisting of DAE (distilled oil aromatic extract), Tdae (treated distilled aromatic extract), MES (light extraction solvate), RAE (residual aromatic extract), TRAE (treated residual aromatic extract), naphthenic oil, heavy naphthenic oil, paraffin oil, vegetable oils such as coconut oil, alkylbenzene oil, and synthetic oils such as castor oil. Preferably, the SBR copolymer is extended with an aromatic oil such as a treated distilled aromatic extract (Tdae) such that the extended SBR copolymer contains 2.5 to 7.5 phr of the treated distilled aromatic extract oil.

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

[0067] The composition may further contain a diene elastomer. The diene elastomer is an elastomer derived from a diene monomer, i.e., at least a portion (e.g., a homopolymer or copolymer) of monomers 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 copolymers, isoprene copolymers, and mixtures thereof. In a preferred embodiment, the diene elastomer is polybutadiene rubber. The T of polybutadiene rubber g The temperature range may be -120°C to -80°C, preferably -110°C to -90°C, for example, -110°C, -100°C, -95°C, or -90°C. If present, the diene elastomer may be included in an amount of 10 to 60 phr, preferably 20 to 55 phr.

[0068] 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 high inorganic reinforcing filler loading may be beneficial in providing the technical effects of the present invention. Preferably, the silica-based filler is silica (SiO2). Further preferred silvery 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.

[0069] The rubber composition may include additional fillers such as carbon black (i.e., fillers in addition to inorganic reinforcing fillers). The carbon black may be furnace black, channel black, and ramp black. For example, the carbon black may be one or more selected from the group consisting of superabrasion furnace (SAF) black, high abrasion furnace (HAF) black, fast extrusion furnace (FEF) black, fine furnace (FF) black, intermediate superabrasion furnace (ISAF) black, semi-reinforced furnace (SRF) black, medium-processed channel black, hard-processed channel black, and conductive channel black. Another carbon black that may be used is acetylene black. The carbon black may be in pelletized form or in unpelletized aggregates. A specific example of carbon black in the rubber composition of the present invention is CORAX® N234 manufactured 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, 2 to 8 phr, for example, 2, 3, 4, 5, 6, 7, or 8 phr.

[0070] 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, paraffin oils, DAE oils, MES (medium extract solvate) oils, TDAE (treated distilled aromatic extract) oils, RAE (residual aromatic extract) oils, TRAE (treated residual aromatic extract) oils, and SRAE (safe residual aromatic extract) oils, mineral oils, vegetable oils, ether plasticizers, ester plasticizers, preferably oleates, such as octyl oleate or 2-ethylhexyl oleate, phosphate plasticizers, sulfonate 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, 8, 9, 10, 11, 12, 13, 14, or 15 phr.

[0071] In addition to the components described above, the rubber composition may also contain additional components that a person skilled in the art would include to prepare a rubber composition suitable for the preparation of pneumatic tires. These include, for example, vulcanizing agents (such as sulfur), vulcanization accelerators, vulcanization accelerators, silane coupling agents, degradation inhibitors (such as antioxidants or ozone degradation inhibitors), waxes, and processing agents.

[0072] In a particularly preferred embodiment, the rubber composition is T g A copolymer of styrene and butadiene, optionally functionalized with terminal carboxyl groups; Arbitrarily, T between -120°C and -80°C g Butadiene rubber having; At a dose of 7 phr to 22 phr, at a temperature of 55°C to 80°C. g A first hydrocarbon resin which is a terpene resin having; and At a volume of 30 phr to 55 phr, at a temperature of 40°C to 60°C. g A second hydrocarbon resin which is a rosin-based resin having; Resin-based substances present in amounts of 40-70 phr; Reinforcing inorganic filler present in an optional amount of 80-120 phr; Includes, The ratio of the amount of the first hydrocarbon resin to the amount of the second hydrocarbon resin is between 0.15:1 and 0.9:1.

[0073] In preparing the rubber composition of the present invention, the method of compounding 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 together, or they may be compounded and kneaded in multiple stages. Kneaders such as roll kneaders, internal mixers, and Banbury mixers can be used for compounding and kneading. Any known molding machine such as an extruder or press molding machine can be used to form the rubber composition into a sheet or strip. The vulcanization conditions for curing the rubber composition are not limited, and those known to those skilled in the art can be used. However, typically, vulcanization conditions of 140 to 180°C for 5 to 120 minutes are employed.

[0074] Unless otherwise specified, the amounts of components in the rubber composition of the present invention are given in parts per 100 parts of rubber (phr), which means parts per 100 parts of elastomer (or total elastomer if several elastomers are present). The term "rubber composition" may be used interchangeably with the term "rubber compound."

[0075] Pneumatic tires In a further embodiment, the present invention relates to a pneumatic tire. The pneumatic tire is not particularly limited and may be, for example, a tire used in passenger cars, motorcycles, and commercial vehicles. The pneumatic tire may be suitable for all types 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 effect of the rubber composition of the present invention makes it particularly suitable for use in tires having good winter performance.

[0076] In view of the above, 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.

[0077] In a further embodiment, the present invention relates to the use of rubber compositions in the manufacture of pneumatic tires.

[0078] 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 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 advantageous for use in tread components.

[0079] Regarding the manufacturing method of the tire, any method known to those skilled in the art can be used. For example, components commonly used in tire manufacturing, such as a carcass layer, belt layer, and tread layer, consisting of at least one selected from the group consisting of an unvulcanized rubber composition and cords, are sequentially laminated on a tire molding drum, and then the drum is removed to obtain a green tire. Next, the green tire is heat-vulcanized according to a conventional method to produce the desired tire. [Examples]

[0080] Next, the present invention will be described by the following non-limiting embodiments.

[0081] Measurement method Glass transition temperature (T g ) Glass transition temperature (T g The values ​​were measured by differential scanning calorimetry (DSC) according to standard ASTM D3418 (1999).

[0082] Pain effect The Payne effect was calculated from the compound dynamic properties measured according to the ISO 4664 standard.

[0083] Mooney viscosity Mooney viscosity was measured for functionalized or unfunctionalized polymers of the raw materials according to the ASTM D1646 standard.

[0084] Modulus of elasticity (E') The modulus of elasticity (E') is used to evaluate grip performance. Dynamic physical tests were performed to determine E' at 30°C and -20°C according to the ISO 4664 standard.

[0085] Loss factor (tanδ) Rolling resistance and wet traction are evaluated using loss factors (tangent δ, or tanδ) at different temperatures.

[0086] 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 to determine tanδ were performed according to ISO 4664 standard.

[0087] 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 tread test specimens prepared using the compositions in Table 1.

[0088] component Elastomer: Terminal carboxyl groups and -60°C T g A functionalized solution of styrene-butadiene rubber (prepared using the method described in International Publication No. 2014 / 173706(A1)) (SBR) T g = Butadiene rubber (BR) at -105℃ (uroprene® Neocis BR 40) Silica: Silica (STD-SiO2) (Ultrasil VN3) Hydrocarbon resins: 66℃ T g Aromatic terpene resin (Kraton Sylvatraxx 8115) 49℃ Tg , an aromatic rosin resin (Kraton Sylvatraxx 2097) with an aromaticity of 6.5 Further additives: Carbon Black (Corax® N234) Silane (Evonik Industries AG Si 69 (registered trademark)) Paraffin wax MES oil Processed distillation 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] As shown in Figures 1A and 1B, the inventors discovered that certain properties, including E'(30°) and E'(-20°), have peak values ​​when the first and second hydrocarbon resins are within a specific ratio range. E'(30°) is an indicator of the tire's dry handling / balance, and E'(-20°) is an indicator of its snow balance / handling. Therefore, maximizing both of these properties is important when preparing a tire with good winter performance while maintaining good dry performance, and the inventors achieved this using the composition of the present invention.

[0092] Figure 2 shows E'(30°) versus tan Delta(0°) data. E'(30°) is an indicator of dry handling / balance, and tan Delta(0°) is an indicator of wet balance / handling. As shown in Figure 2, the composition of the present invention balances these two properties, providing a tire with excellent handling performance in both wet and dry conditions.

[0093] Figure 3 shows E'(-20°) versus tan Delta(60°) data. E'(-20°) is an indicator of snow handling / balance, and tan Delta(60°) is an indicator of rolling resistance. Figure 3 shows that the compositions of the present invention have a good balance between these properties and demonstrate their superior snow handling.

Claims

1. Glass transition temperature (T) between -90°C and -20°C ｇ ) optionally functionalized copolymers of styrene and butadiene (SBR); - Arbitrarily, T between -130°C and -30°C ｇ Diene elastomer having; T ｇ A first hydrocarbon resin having; and T ｇ A second hydrocarbon resin having; A resin system containing at least 30 phr; A rubber composition for pneumatic tires, comprising: The first and second hydrocarbon resins are different, and the ratio of the amount of the first hydrocarbon resin to the amount of the second hydrocarbon resin is less than 1.5:1 parts per 100 parts (phr) of rubber. Rubber composition for pneumatic tires.

2. The rubber composition according to claim 1, wherein the first and second hydrocarbon resins 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 and second hydrocarbon resins have different aromatic properties, preferably the first hydrocarbon resin has a lower aromatic property than the second hydrocarbon resin, and more preferably the aromatic property of the first hydrocarbon resin is 1 to 10% lower than the aromatic property 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 first hydrocarbon resin to the amount of the second hydrocarbon resin is 0.05:1 to 1.45:1 on a phr basis, preferably 0.1:1 to 1:1, and more preferably 0.15:1 to 0.9:

1.

5. The rubber composition according to any one of claims 1 to 4, wherein the first hydrocarbon resin is present in an amount of up to 30 phr, preferably 5 to 25 phr, more preferably 7 to 22 phr.

6. The rubber composition according to any one of claims 1 to 5, wherein the second hydrocarbon resin is present in an amount of up to 70 phr, preferably 20 to 65 phr, more preferably 25 to 60 phr, and more preferably 30 to 55 phr.

7. 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 6, having the following characteristics.

8. 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 7, having the following characteristics.

9. The rubber composition according to any one of claims 1 to 8, wherein the first hydrocarbon resin is a terpene resin.

10. The rubber composition according to any one of claims 1 to 9, wherein the second hydrocarbon resin is a rosin-based resin.

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 T of the styrene-butadiene copolymer ｇ The rubber composition according to any one of claims 1 to 11, wherein the temperature range is -75°C to -40°C, preferably -65°C to -50°C.

13. The rubber composition according to any one of claims 1 to 12, wherein the copolymer of styrene and butadiene is present in an amount of 40 to 90 phr, preferably 45 to 80 phr.

14. The rubber composition according to any one of claims 1 to 13, wherein the copolymer of styrene and butadiene is functionalized with carboxyl groups, preferably terminal carboxyl groups.

15. The carboxyl group is a group of formula (I), 【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, may contain one or more heteroatoms, and preferably, the heteroatom is one or more selected from the group consisting of O, N, S and Si. R ３ and R ４ These are the same or different, and each is independently a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl radical, and may contain one or more heteroatoms, preferably one or more selected from the group consisting of O, N, S, and Si. A is an alkyl radical; O, NR ７ , S and SiR ８ R ９ A divalent organic radical which may be one or more heteroatoms selected from the group consisting of; or an alkyl radical containing one or more heteroatoms, preferably the heteroatoms being O, NR ７ , S and SiR ８ R ９ One or more selected from the group consisting of R ７ is hydrogen, C １ ~C ６ Linear alkyl, preferably methyl or trimethylsilyl, R ８ and R ９ C １ ~C ６ Linear alkyl, preferably methyl, The rubber composition according to claim 14.

16. The carboxyl group is bonded to the copolymer of styrene and butadiene via one or more divalent structural elements of formula (V), 【Chemistry 2】 Preferably, the divalent structural element is of formula (IV): 【Transformation 3】 Derived from cyclosiloxane, n is an integer between 3 and 6. R ５ , R ６ These are the same or different, each independently of a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl radical, and may contain one or more heteroatoms, preferably the heteroatoms being O, N, S, or Si, and more preferably the divalent structural element is derived from one or more cyclic siloxanes selected from the group consisting of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. The rubber composition according to claim 14 or 15.

17. The rubber composition according to any one of claims 1 to 16, wherein the composition comprises a diene elastomer, preferably the diene elastomer being polybutadiene rubber.

18. The T of the aforementioned diene elastomer ｇ The rubber composition according to any one of claims 1 to 17, wherein the temperature range is -120°C to -80°C, preferably -110°C to -90°C.

19. The rubber composition according to any one of claims 1 to 18, wherein the diene elastomer is present in an amount of 20 to 60 phr, preferably 40 to 55 phr.

20. The rubber composition according to any one of claims 1 to 19, wherein the rubber composition further comprises at least 70 phr, preferably 80 to 120 phr, of an inorganic reinforcing filler, preferably silica.

21. T at -75°C to -40°C ｇ A copolymer of styrene and butadiene having, optionally functionalized with terminal carboxyl groups; Arbitrarily, T between -120°C and -80°C ｇ Butadiene rubber having; A dose of 7 phr to 22 phr at 55°C to 80°C ｇ A first hydrocarbon resin which is a terpene resin having; and A quantity of 30 to 55 phr at 40°C to 60°C ｇ A second hydrocarbon resin which is a rosin-based resin having; A resin system containing 40 to 70 phr; Reinforcing inorganic filler present in an arbitrary amount of 80 to 120 phr. A rubber composition comprising, The ratio of the amount of the first hydrocarbon resin to the amount of the second hydrocarbon resin is 0.15:1 to 0.9:

1. A hydrocarbon resin according to any one of claims 1 to 20.

22. Use of the rubber composition according to any one of claims 1 to 21 in the manufacture of a pneumatic tire.

23. A pneumatic tire comprising the rubber composition according to any one of claims 1 to 21.

24. A pneumatic tire made from the rubber composition described in any one of claims 1 to 21.

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