Hydrogenated petroleum resin, rubber additive, uncrosslinked rubber composition, crosslinked rubber, and tire

Abstract

A hydrogenated petroleum resin which is a hydrogenate of a C9-based petroleum resin, wherein the ratio (M2 / M1) of the total number (M2) of hydrogen atoms bonded to aromatic rings in the aforementioned hydrogenated petroleum resin to the total number (M1) of hydrogen atoms in the aforementioned hydrogenated petroleum resin is 0.15 to 0.45.

Description

Technical Field

[0001] This invention relates to hydrogenated petroleum resins, rubber additives, uncrosslinked rubber compositions, crosslinked rubbers, and tires. Background Technology

[0002] In the past, various additives have been used as rubber additives to impart various properties to rubber components.

[0003] For example, Patent Document 1 discloses a rubber composition which is made by blending a hydrogenated resin, a low molecular weight modified conjugated diene polymer and a reinforcing filler into a rubber matrix comprising a diene rubber and a high molecular weight modified conjugated diene polymer.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-88988 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] If the rubber additives have good compatibility with the rubber components, it is expected that they will impart properties more uniformly and efficiently.

[0009] Therefore, the object of the present invention is to provide a hydrogenated petroleum resin that has high compatibility with rubber components and good color, and is suitable as an additive for rubber.

[0010] Furthermore, in recent years, from the perspective of improving fuel efficiency, there has been a strong demand for tires with good rolling resistance characteristics. On the other hand, from a safety perspective, there is a strong demand for tires with excellent wet grip performance. However, it is difficult to simultaneously achieve good rolling resistance characteristics and excellent wet grip performance.

[0011] Therefore, the object of the present invention is to provide a hydrogenated petroleum resin that imparts good rolling resistance characteristics and excellent wet grip performance to crosslinked rubber. Furthermore, the object of the present invention is to provide a rubber additive comprising the above-mentioned hydrogenated petroleum resin, an uncrosslinked rubber composition comprising the rubber additive, a crosslinked rubber formed by crosslinking the uncrosslinked rubber composition, and a tire containing the crosslinked rubber in the tread portion.

[0012] Solution for solving the problem

[0013] One aspect of the present invention relates to a hydrogenated petroleum resin, which is a hydrogenation of a C9-based petroleum resin, wherein the ratio (M2 / M1) of the total number of hydrogen atoms bonded to the aromatic ring in the hydrogenated petroleum resin to the total number of hydrogen atoms in the hydrogenated petroleum resin is 0.15 to 0.45.

[0014] In one approach, the ratio (M2 / M1) can be 0.2 to 0.4.

[0015] The softening point of one type of hydrogenated petroleum resin can be 70–200°C.

[0016] One method of hydrogenated petroleum resin can have an iodine value of less than 20.

[0017] Another aspect of the present invention relates to a rubber additive comprising the aforementioned hydrogenated petroleum resin.

[0018] Another aspect of the present invention relates to an uncrosslinked rubber composition containing a rubber component, the aforementioned rubber additives, and a crosslinking agent.

[0019] Another aspect of the present invention relates to a crosslinked rubber formed by crosslinking the above-mentioned uncrosslinked rubber composition.

[0020] Another aspect of the invention relates to a tire having the aforementioned cross-linked rubber in the tread portion.

[0021] The effects of the invention

[0022] According to the present invention, a hydrogenated petroleum resin with high compatibility and good hue is provided.

[0023] Furthermore, according to the present invention, a hydrogenated petroleum resin is provided that can impart good rolling resistance characteristics and excellent wet grip performance to crosslinked rubber. Moreover, according to the present invention, a rubber additive comprising the above-mentioned hydrogenated petroleum resin, an uncrosslinked rubber composition comprising the rubber additive, a crosslinked rubber formed by crosslinking the uncrosslinked rubber composition, and a tire containing the crosslinked rubber in the tread portion are provided. Detailed Implementation

[0024] The preferred embodiments of the present invention will now be described in detail.

[0025] <Hydrogenated Petroleum Resin>

[0026] The hydrogenated petroleum resin in this embodiment is a hydride (also called a partially hydrogenated) of C9 series petroleum resin. In this embodiment, the ratio (M2 / M1) of the total number of hydrogen atoms bonded to the aromatic ring in the hydrogenated petroleum resin to the total number of hydrogen atoms (M1) in the hydrogenated petroleum resin is 0.15 to 0.45.

[0027] In this specification, the ratio (M2 / M1) can be obtained through hydrogenated petroleum resin. 1 The value is determined by H-NMR measurement. That is, the ratio (M2 / M1) can also refer to the hydrogenated petroleum resin's... 1 The ratio (S2 / S1) of the sum of the peak areas (S2) representing hydrogen atoms bonded to aromatic rings in hydrogenated petroleum resins to the sum of the peak areas (S1) representing hydrogen atoms in hydrogenated petroleum resins in the H-NMR spectrum.

[0028] The ratio (M2 / M1) can also refer to an indicator of the aromatic content (the proportion of aromatic rings) in hydrogenated petroleum resin. That is, the hydrogenated petroleum resin of this embodiment can refer to a hydrogenated product of C9 series petroleum resin hydrogenated in the range of 0.15 to 0.45. It should be noted that this ratio in C9 series petroleum resin is typically around 0.45. In other words, the hydrogenated petroleum resin of this embodiment can refer to a hydrogenated product in which aromatic rings are intentionally retained during hydrogenation to achieve a ratio (M2 / M1) of 0.15 or higher.

[0029] The hydrogenated petroleum resin of this embodiment removes the olefinic unsaturated bonds, the main cause of yellowing, through hydrogenation, while intentionally retaining aromatic rings to achieve a ratio (M2 / M1) of 0.15 or higher. In other words, the hydrogenated petroleum resin of this embodiment can sufficiently suppress yellowing and obtain a good hue through the hydrogenation of olefinic unsaturated bonds, while simultaneously achieving high compatibility by intentionally retaining aromatic rings.

[0030] Furthermore, the hydrogenated petroleum resin of this embodiment can impart good rolling resistance characteristics and excellent wet grip performance to rubber materials. Therefore, the hydrogenated petroleum resin of this embodiment is suitable for use as a rubber additive (more preferably a tire rubber additive).

[0031] Regarding rolling resistance characteristics, it is known that in dynamic viscoelasticity tests of rubber materials, the smaller the loss coefficient (tanδ) measured near 10 Hz and 60°C, the better the rolling resistance characteristics. On the other hand, regarding wet grip performance, it is known that in dynamic viscoelasticity tests of rubber materials, the larger the loss coefficient (tanδ) measured near 10 Hz and 0°C, the better the wet grip performance.

[0032] Rolling resistance characteristics and wet grip performance both refer to the hysteresis loss characteristics of rubber materials. Generally speaking, increasing hysteresis loss increases grip and improves braking performance, but it also increases rolling resistance, leading to worse fuel consumption. Therefore, grip performance and rolling resistance characteristics are inversely related, making it difficult to simultaneously achieve both good rolling resistance characteristics and excellent wet grip performance.

[0033] The hydrogenated petroleum resin of this embodiment, by adding it to the rubber material, can maintain a low loss coefficient (tanδ) at high temperatures (e.g., 60°C) and increase the loss coefficient (tanδ) at low temperatures (e.g., 0°C) in the dynamic viscoelasticity test. Therefore, it can impart good rolling resistance characteristics and excellent wet grip performance to the rubber material.

[0034] The inventors have considered the mechanism by which the above-mentioned effects occur as follows. Generally, the peak of the loss coefficient (tanδ) of rubber is located in the temperature region below 0°C. Furthermore, it is known that the softening point of petroleum resin is usually higher than the glass transition temperature (Tg) of rubber. Therefore, by adding petroleum resin to the rubber material, the peak of the loss coefficient (tanδ) can be shifted towards the high-temperature side, increasing the loss coefficient (tanδ) near 0°C.

[0035] It can be considered that, in ordinary petroleum resins, the crosslinking of the rubber component with the petroleum resin is insufficient due to the reaction of the olefinic unsaturated bonds in the petroleum resin with the crosslinking agent, or the insufficient crosslinking of the rubber component due to the consumption of the crosslinking agent by the olefinic unsaturated bonds, resulting in an insufficient peak shift of the loss coefficient (tanδ). In contrast, in this embodiment, since a hydride of C9-based petroleum resin is used, it can be considered that the olefinic unsaturated bonds are reduced by hydrogenation, thus avoiding these problems and enabling the peak of the loss coefficient (tanδ) to shift efficiently to the high-temperature side.

[0036] Furthermore, in this embodiment, by retaining sufficient aromatic rings in the hydrogenated petroleum resin, the compatibility with the rubber component is improved. It can be considered that, through this improved compatibility, the peak of the loss coefficient (tanδ) becomes sharper, and the loss coefficient (tanδ) near 60°C is suppressed to a lower value.

[0037] The hydrogenated petroleum resin of this embodiment can also impart excellent dry grip performance to rubber materials. Dry grip performance is a required characteristic for sports tires, racing tires, etc. Therefore, the hydrogenated petroleum resin of this embodiment is suitable for use as an additive for rubber used in sports tires, rubber used in racing tires, etc.

[0038] It should be noted that, in dynamic viscoelasticity tests of rubber materials, a higher loss coefficient (tanδ) measured at a frequency of 10 Hz and around 20°C indicates better dry grip performance. The hydrogenated petroleum resin of this embodiment, by being added to the rubber material, can maintain a low loss coefficient (tanδ) at high temperatures (e.g., 60°C) in dynamic viscoelasticity tests while simultaneously increasing the loss coefficient (tanδ) at room temperature (e.g., 20°C). Therefore, it can impart good rolling resistance characteristics and excellent dry grip performance to the rubber material.

[0039] The hydrogenated petroleum resin of this embodiment (hereinafter also referred to as hydrogenated petroleum resin) will now be described in detail.

[0040] Hydrogenated petroleum resin is a hydrogenated form of C9 series petroleum resin. As mentioned above, hydrogenated petroleum resin is a hydrogenated form of C9 series petroleum resin with a ratio (M2 / M1) of 0.15 or higher. Therefore, it can also be called a partially hydrogenated form of C9 series petroleum resin.

[0041] C9-based petroleum resins can be resins obtained by curing C9 fractions collected from petroleum feedstocks through thermal decomposition, or resins obtained by curing a mixture of the C9 fraction with other hydrocarbons (wherein the C9 fraction is 90% by mass or more, preferably 95% by mass or more). It should be noted that the C9 fraction refers to a fraction that mainly (e.g., 60% by mass or more, preferably 80% by mass or more) contains hydrocarbons with 9 carbon atoms, and may further contain components other than hydrocarbons with 9 carbon atoms (e.g., hydrocarbons with 8 or 10 carbon atoms (styrene, methyl indene, etc.)).

[0042] C9 fraction can be, for example, the C9 fraction collected during the thermal decomposition of petroleum naphtha.

[0043] C9 fractions can contain both saturated and unsaturated components. Examples of saturated components include propylbenzene, methylethylbenzene, and indene. Examples of unsaturated components include styrene, methylstyrene, vinyltoluene, dicyclopentadiene, indene, and methylindene.

[0044] There are no particular limitations on the preparation method of C9-based petroleum resins; they can be manufactured using known methods. For example, C9-based petroleum resins can be manufactured by the following method: First, polymerization is carried out at a temperature of 0–60°C using a Lewis acid catalyst at a ratio of 0.01–5 parts by mass relative to 100 parts by mass of the C9 fraction. Next, 0.1–20 parts by mass of an alkaline substance is added to the reaction system, and a neutralization reaction is carried out at a temperature of 10–100°C. After the neutralization reaction, the resin is washed with water as needed, and then 0.1–20 parts by mass of activated clay is added, followed by clay treatment at a temperature of 10–100°C. After clay treatment, the clay is filtered out, and unreacted components are removed by distillation to obtain the C9-based petroleum resin.

[0045] The ratio (M4 / M3) of the total number of hydrogen atoms bonded to the aromatic ring in the C9-based petroleum resin to the total number of hydrogen atoms in the C9-based petroleum resin is not particularly limited, as long as the ratio (M2 / M1) of the hydrogenated petroleum resin after hydrogenation is within the above-mentioned range. The ratio (M4 / M3) of the C9-based petroleum resin is, for example, 0.2 to 0.5, preferably 0.3 to 0.5, and more preferably 0.4 to 0.5.

[0046] It should be noted that the ratio (M4 / M3) can be achieved through C9 series petroleum resins. 1 The value is determined by ¹H-NMR measurement. That is, the ratio (M₄ / M₃) can also refer to the C9 series petroleum resin. 1 The ratio (S4 / S3) of the sum of the peak areas (S4) representing hydrogen atoms bonded to aromatic rings in C9 petroleum resins to the sum of the peak areas (S3) representing hydrogen atoms in C9 petroleum resins in the H-NMR spectrum.

[0047] The softening point of C9-based petroleum resin can be, for example, below 200°C, preferably below 170°C, and may also be below 160°C, 150°C, or 140°C. Furthermore, the softening point of C9-based petroleum resin can be, for example, above 70°C, preferably above 80°C, and more preferably above 90°C. Therefore, it is easy to obtain hydrogenated petroleum resins with suitable softening points, as described later. That is, the softening point of C9-based petroleum resin can be, for example, 70–200°C, 70–170°C, 70–160°C, 70–150°C, 70–140°C, 80–200°C, 80–170°C, 80–160°C, 80–150°C, 80–140°C, 90–200°C, 90–170°C, 90–160°C, 90–150°C, or 90–140°C.

[0048] It should be noted that the softening point in this specification refers to the value measured in accordance with the method of ASTM D6090.

[0049] There is no particular limitation on the iodine value of C9 series petroleum resins; for example, it can be above 25, above 30, or above 40. Furthermore, there is no particular limitation on the iodine value of C9 series petroleum resins; for example, it can be below 100 or below 80. That is, the iodine value of C9 series petroleum resins can be, for example, 25–100, 25–80, 30–100, 30–80, 40–100, or 40–80.

[0050] It should be noted that the iodine value in this instruction manual refers to the value measured in accordance with JIS K 0070:1992.

[0051] There is no particular limitation on the hydrogenation method of C9-based petroleum resins, and it can be carried out by known methods. For example, the hydrogenation of C9-based petroleum resins can be carried out by contacting the C9-based petroleum resins with a hydrogenation catalyst in the presence of molecular hydrogen.

[0052] There are no particular limitations on the hydrogenation catalyst; for example, it can be a nickel-based catalyst, a palladium-based catalyst, a platinum-based catalyst, etc.

[0053] There are no particular limitations on the hydrogenation conditions, which can be appropriately modified to obtain a suitable ratio (M2 / M1) and iodine value. The hydrogen pressure during hydrogenation can be, for example, 2 to 30 MPa, and the reaction temperature can be, for example, 200 to 310 °C.

[0054] C9-based petroleum resins can also be dissolved in solvents to allow them to contact hydrogenation catalysts. The solvent must be capable of dissolving the C9-based petroleum resin and will not adversely affect hydrogenation. Examples of suitable solvents include kerosene and methylcyclohexane. One solvent can be used alone, or two or more solvents can be used in combination.

[0055] The ratio (M2 / M1) of the hydrogenated petroleum resin is 0.15 or more, preferably 0.17 or more, more preferably 0.19 or more, and even more preferably 0.2 or more. This further improves the compatibility with the resin and makes the aforementioned effects more significant. Alternatively, the ratio (M2 / M1) of the hydrogenated petroleum resin is 0.45 or less, and may also be 0.43 or less, 0.4 or less, or 0.38 or less. That is, the ratio of hydrogenated petroleum resin (M2 / M1) can be, for example, 0.15–0.45, 0.15–0.43, 0.15–0.4, 0.15–0.38, 0.17–0.45, 0.17–0.43, 0.17–0.4, 0.17–0.38, 0.19–0.45, 0.19–0.43, 0.19–0.4, 0.19–0.38, 0.2–0.45, 0.2–0.43, 0.2–0.4, or 0.2–0.38.

[0056] The iodine value of hydrogenated petroleum resin is lower than that of C9 series petroleum resin. The ratio (I2 / I1) of the iodine value (I2) of hydrogenated petroleum resin to the iodine value (I1) of C9 series petroleum resin is, for example, 0.6 or less, preferably 0.5 or less, more preferably 0.4 or less, and may also be 0.

[0057] The iodine value of the hydrogenated petroleum resin is not particularly limited, but is, for example, 20 or less, preferably 18 or less, more preferably 17 or less, even more preferably 16 or less, and may also be 15 or less. This effectively suppresses the adverse effects caused by the presence of olefinic unsaturated bonds, and more significantly exerts the aforementioned effects. The lower limit of the iodine value of the hydrogenated petroleum resin is not particularly limited; for example, the iodine value of the hydrogenated petroleum resin may be 0 or more, 1 or more, 2 or more, or 3 or more. That is, the iodine value of the hydrogenated petroleum resin may, for example, be 0–20, 0–18, 0–17, 0–16, 0–15, 1–20, 1–18, 1–17, 1–16, 1–15, 2–20, 2–18, 2–17, 2–16, 2–15, 3–20, 3–18, 3–17, 3–16, or 3–15. It should be noted that the iodine value of the hydrogenated petroleum resin can refer to an indicator of the amount of olefinic unsaturated bonds in the hydrogenated petroleum resin. The olefinic unsaturated bonds in hydrogenated petroleum resins include: olefinic unsaturated bonds that have not been hydrogenated, and olefinic unsaturated bonds formed by hydrogenation of a portion of the aromatic ring.

[0058] The softening point of the hydrogenated petroleum resin can be, for example, 70°C or higher, preferably 80°C or higher, and more preferably 90°C or higher. If the softening point of the hydrogenated petroleum resin is high, the peak of the loss coefficient (tanδ) shifts towards a higher temperature, making it easier to obtain superior wet grip performance. Conversely, the softening point of the hydrogenated petroleum resin can be, for example, 200°C or lower, preferably 170°C or lower, but also 160°C or lower, 150°C or lower, or 140°C or lower. If the softening point of the hydrogenated petroleum resin is low, the excessive peak shift of the loss coefficient (tanδ) is suppressed, making it easier to obtain superior rolling resistance characteristics. That is, the softening point of hydrogenated petroleum resin can be, for example, 70–200℃, 70–170℃, 70–160℃, 70–150℃, 70–140℃, 80–200℃, 80–170℃, 80–160℃, 80–150℃, 80–140℃, 90–200℃, 90–170℃, 90–160℃, 90–150℃, or 90–140℃.

[0059] The weight-average molecular weight of hydrogenated petroleum resins is not particularly limited; for example, it can be below 4000, below 3500, or below 3000. If the weight-average molecular weight of the hydrogenated petroleum resin is low, there is a tendency for the softening point to decrease. Conversely, the weight-average molecular weight of hydrogenated petroleum resins can be, for example, above 700 or above 1000. If the weight-average molecular weight of the hydrogenated petroleum resin is high, there is a tendency for the softening point to increase. That is, the weight-average molecular weight of hydrogenated petroleum resins can be, for example, 700–4000, 700–3500, 700–3000, 1000–4000, 1000–3500, or 1000–3000.

[0060] It should be noted that the weight-average molecular weight of hydrogenated petroleum resin refers to the converted value of standard polystyrene determined by GPC (gel permeation chromatography).

[0061] The hydrogenated petroleum resin of this embodiment is suitable for use as an additive for rubber, an additive for plastics, an additive for films, an adhesive, and other applications.

[0062] <Additives for Rubber>

[0063] The rubber additive of this embodiment comprises the aforementioned hydrogenated petroleum resin. The rubber additive of this embodiment can impart good rolling resistance characteristics and excellent wet grip performance to rubber materials.

[0064] The rubber additive of this embodiment may be an additive composed solely of hydrogenated petroleum resin, or it may be an additive containing hydrogenated petroleum resin and other components. As other components, known components can be used as rubber additives without particular limitation. Examples of other components include those that may be contained in the uncrosslinked rubber composition described later.

[0065] The amount of rubber additive added to the rubber component in this embodiment is not particularly limited, but the amount of hydrogenated petroleum resin added relative to 100 parts by mass of the rubber component is preferably an amount that reaches the preferred range described later.

[0066] The amount of hydrogenated petroleum resin added relative to 100 parts by weight of the rubber component is preferably 1 part by weight or more, more preferably 3 parts by weight or more. This tends to further improve wet grip performance. Alternatively, the amount of hydrogenated petroleum resin added relative to 100 parts by weight of the rubber component can be, for example, 40 parts by weight or less, preferably 30 parts by weight or less. This tends to improve the elasticity of the rubber. That is, the amount of hydrogenated petroleum resin added relative to 100 parts by weight of the rubber component can be, for example, 1 to 40 parts by weight, 1 to 30 parts by weight, 3 to 40 parts by weight, or 3 to 30 parts by weight.

[0067] <Uncrosslinked rubber composition>

[0068] The uncrosslinked rubber composition of this embodiment contains a rubber component, the aforementioned rubber additive, and a crosslinking agent. The crosslinked rubber obtained by crosslinking the aforementioned uncrosslinked rubber composition, for example, when used in the tread of a tire, exhibits good rolling resistance characteristics and excellent wet grip performance.

[0069] There are no particular limitations on the rubber components, and known rubber components can be used without special restrictions. From the viewpoints of strength, processability, and price, butadiene rubber (BR), styrene-butadiene rubber (SBR), and natural rubber (NR) are preferred as rubber components. One type of rubber component can be used alone, or two or more can be used in combination.

[0070] The glass transition temperature (Tg) of the rubber component can be, for example, below 0°C, preferably below -20°C. Furthermore, the glass transition temperature (Tg) of the rubber component can be, for example, above -120°C, preferably above -100°C. That is, the Tg of the rubber component can be, for example, -120 to 0°C, -120 to -20°C, -100 to 0°C, or -100 to -20°C. It should be noted that, in this specification, the glass transition temperature of the rubber component refers to the value measured using DSC (Differential Scanning Calorimetry).

[0071] As a crosslinking agent, there can be no particular restrictions on the use of crosslinking agents commonly used for rubber crosslinking, and the agent can be appropriately selected according to the rubber composition. Examples of crosslinking agents include sulfur crosslinking agents (such as sulfur, morpholine disulfide, alkylphenol disulfide, etc.) and organic peroxide crosslinking agents. One crosslinking agent can be used alone, or two or more can be used in combination.

[0072] The content of the crosslinking agent relative to 100 parts by weight of the rubber component is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 3 parts by weight, and even more preferably 1 to 2 parts by weight. That is, the content of the crosslinking agent relative to 100 parts by weight of the rubber component can be, for example, 0.1 to 5 parts by weight, 0.1 to 3 parts by weight, 0.1 to 2 parts by weight, 0.5 to 5 parts by weight, 0.5 to 3 parts by weight, 0.5 to 2 parts by weight, 1 to 5 parts by weight, 1 to 3 parts by weight, or 1 to 2 parts by weight.

[0073] The uncrosslinked rubber composition of this embodiment may further contain various reinforcing agents, fillers, rubber filler oils, softeners, etc., used in the rubber industry. Each component may be used alone or in combination of two or more.

[0074] Examples of reinforcing agents include carbon black and silicon dioxide.

[0075] Carbon black can improve the abrasion resistance and rolling resistance of cross-linked rubber, and prevent UV-induced cracking and fissures (preventing UV degradation), making it suitable as a reinforcing agent. There are no particular limitations on the type of carbon black used; conventionally known carbon blacks can be employed.

[0076] In addition, there are no particular limitations on the physical properties of carbon black, such as particle size, pore volume, and specific surface area, and various types of carbon black currently used in the rubber industry can be used appropriately.

[0077] When using carbon black, its content is preferably 5 to 80 parts by mass, more preferably 10 to 60 parts by mass, relative to 100 parts by mass of the rubber component. With such a blending amount, it can effectively act as a reinforcing agent in the crosslinked rubber obtained by crosslinking the uncrosslinked rubber composition.

[0078] As silica, silica that has traditionally been used as a reinforcing agent for rubber can be used without particular restrictions. There are no particular limitations on the specific surface area of ​​silica; typically, 40–600 m² is used. 2 / g range, preferably 70~300m 2 For silicon dioxide per gram, silicon dioxide with a primary particle size of 10–1000 nm can be used.

[0079] When using silica, its mixing amount is preferably 0.1 to 150 parts by mass relative to 100 parts by mass of the rubber component, more preferably 10 to 130 parts by mass, and even more preferably 30 to 110 parts by mass.

[0080] In addition, for the purpose of compounding silica, silane coupling agents can be compounded into the uncrosslinked rubber composition. Known silane coupling agents can be used without particular restriction. Silane coupling agents can be used alone or in combination of two or more.

[0081] The amount of silane coupling agent added can be appropriately changed according to the desired amount of silica, preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the rubber component.

[0082] As a filler, mineral powders, carbonates, alumina hydrates, etc., can be used.

[0083] As a rubber filler oil, conventionally used aromatic oils, naphthenic oils, and alkane oils can be used. The mixing amount of the rubber filler oil relative to 100 parts by weight of the rubber component is preferably 0 to 100 parts by weight.

[0084] Examples of plasticizers include tall oil, vegetable oils, alkane oils, naphthenic oils, aromatic oils, and phthalic acid derivatives. The amount of plasticizer mixed in is preferably 0 to 50 parts by weight relative to 100 parts by weight of the rubber component.

[0085] The uncrosslinked rubber composition of this embodiment may further contain, as needed, one or more of various additives used in the rubber industry, such as antioxidants, crosslinking agents, vulcanization accelerators, vulcanization aids, vulcanization delayers, plasticizers, processing oils, and plasticizers. The amount of these additives mixed in is preferably 0.1 to 10 parts by weight relative to 100 parts by weight of the rubber component.

[0086] As a vulcanization accelerator or vulcanization aid, there are no particular limitations; it can be appropriately selected and used according to the rubber components and crosslinking agents contained in the rubber composition. It should be noted that "vulcanization" refers to crosslinking involving at least one sulfur atom.

[0087] Examples of vulcanization accelerators include: thiuram-based accelerators, thiazole-based accelerators, sulfenamide-based accelerators (e.g., N-cyclohexyl-2-benzothiazole sulfenamide), guanidine-based accelerators (e.g., diphenylguanidine), aldehyde-amine-based accelerators, and urea-based accelerators.

[0088] When these vulcanization accelerators are blended, one type can be used alone, or two or more types can be used in combination. The amount of vulcanization accelerator blended relative to 100 parts by weight of rubber component is preferably 0.1 to 10 parts by weight.

[0089] Examples of vulcanizing aids include: metal oxides (e.g., zinc oxide), metal hydroxides, metal carbonates, fatty acids (e.g., stearic acid), and metal salts of fatty acids.

[0090] When these vulcanizing auxiliaries are blended, one type can be used alone, or two or more types can be used in combination. The preferred blending amount of the vulcanizing auxiliaries relative to 100 parts by weight of the rubber component is 0.1 to 10 parts by weight.

[0091] The uncrosslinked rubber composition of this embodiment can be manufactured by applying methods commonly used for manufacturing uncrosslinked rubber compositions. For example, it can be manufactured by mixing the above-mentioned components using a mixing mill such as a Brabender internal mixer, a Banbury mixer, or a roll mill.

[0092] Cross-linked rubber

[0093] The crosslinked rubber of this embodiment is formed by crosslinking the above-described uncrosslinked rubber composition. Such a crosslinked rubber is useful, for example, as a rubber material for tires. Specifically, for example, when the crosslinked rubber of this embodiment is used in the tread of a tire, it can exhibit good rolling resistance characteristics and excellent wet grip performance.

[0094] The crosslinked rubber of this embodiment can be manufactured using the above-described uncrosslinked rubber composition by the same method commonly used for rubber crosslinking. For example, by heating and molding the above-described uncrosslinked rubber composition, a crosslinked rubber can be obtained that is molded into a desired shape and has a structure in which the rubber components are crosslinked.

[0095] The crosslinked rubber of this embodiment is suitable for a variety of applications. For example, it is suitable for use in tires, adhesives, films, medical tapes, coatings, inks, asphalt adhesives, fabrics, waterproofing agents, printer resins, etc., and is particularly suitable for tire applications (especially for tire treads).

[0096] <Tires>

[0097] The tire of this embodiment contains the aforementioned cross-linked rubber.

[0098] The tire of this embodiment preferably contains the aforementioned cross-linked rubber in the tread area. This tire exhibits significantly good rolling resistance characteristics and excellent wet grip performance.

[0099] The tire of this embodiment, except that at least a portion thereof is made of the cross-linked rubber described above, can have the same structure as conventionally known tires.

[0100] The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, the present invention can be a method of imparting good rolling resistance characteristics and excellent wet grip performance to rubber materials by adding the above-mentioned rubber additives to the rubber components used in tires. In this case, existing methods for improving rubber materials are difficult to achieve both good rolling resistance characteristics and excellent wet grip performance. Although rolling resistance characteristics decrease with the improvement of wet grip, the method according to the present invention can impart good rolling resistance characteristics and excellent wet grip performance to rubber materials.

[0101] Example

[0102] The present invention will be described in more detail below through embodiments, but the present invention is not limited to these embodiments.

[0103] (Manufacturing Example A1)

[0104] 100 parts by mass of the C9 fraction (as shown in Table 1) obtained by naphtha cracking and 1.2 parts by mass of boron trifluoride catalyst were added to an autoclave and cationic polymerization was carried out for 1.5 hours to obtain C9-based petroleum resin A1 (as shown in Table 2). It should be noted that the composition of the unsaturated components participating in the polymerization reaction in the C9 fraction is shown in Table 1 below.

[0105] (Manufacturing Examples A2-A6)

[0106] Except for adjusting the polymerization time as shown in Table 2, cationic polymerization was carried out in the same manner as in Manufacturing Example 1 to obtain C9 petroleum resins A2 to A6 as shown in Table 2.

[0107] [Table 1]

[0108]

[0109] [Table 2]

[0110]

[0111] It should be noted that in Table 2, "hue" indicates the result of visually evaluating cases with significant yellowing or other staining as C and cases with almost no yellowing or other staining as A.

[0112] (Example B1)

[0113] 50g of C9 series petroleum resin A1, 110g of diluent (methylcyclohexane), and 2g of 0.5% platinum-supported catalyst were charged into a 0.2L autoclave and hydrogenated at a hydrogen pressure of 3MPaG and 250℃. The reaction solution was appropriately withdrawn, and the reaction was terminated when the specified iodine value was reached. After the reaction, the diluent was removed by distillation to obtain hydrogenated petroleum resin B1. The obtained hydrogenated petroleum resin B1 had a softening point of 125℃, a ratio (M2 / M1) of 0.33, and an iodine value of 13.

[0114] (Example B2)

[0115] Except for changing the hydrogen pressure to 15 MPaG, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin B2. The obtained hydrogenated petroleum resin B2 has a softening point of 125°C, a ratio (M2 / M1) of 0.20, and an iodine value of 10.

[0116] (Example B3)

[0117] Except for replacing C9-based petroleum resin A1 with C9-based petroleum resin A2, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin B3. The obtained hydrogenated petroleum resin B3 has a softening point of 105°C, a ratio (M2 / M1) of 0.35, and an iodine value of 4.

[0118] (Comparative Example b3)

[0119] Except for changing C9-based petroleum resin A1 to C9-based petroleum resin A2, the catalyst to a nickel-synthetic silica-alumina catalyst, the hydrogen pressure to 20 MPaG, and the reaction temperature to 280°C, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin b3. The obtained hydrogenated petroleum resin b3 has a softening point of 105°C, a ratio (M2 / M1) of 0.09, and an iodine value of 2.

[0120] [Table 3]

[0121] Hydrogenated petroleum resin B1 B2 B3 b3 Petroleum resin A1 A1 A2 A2 Softening point (°C) 125 125 105 105 <![CDATA[Ratio (M2 / M1)]]> 0.33 0.2 0.35 0.09 <![CDATA[Iodine value (cgI2 / 100g)]]> 13 10 4 2 tone A A A A MACP (°C) -65 -40 -66 -12 XDCP (°C) 26 35 25 46

[0122] (Example B4)

[0123] Except for replacing C9-based petroleum resin A1 with C9-based petroleum resin A3 and changing the reaction temperature to 300°C, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin B4. The obtained hydrogenated petroleum resin B4 has a softening point of 90°C, a ratio (M2 / M1) of 0.36, and an iodine value of 10.

[0124] (Example B5)

[0125] Except for replacing C9-based petroleum resin A1 with C9-based petroleum resin A4 and changing the reaction temperature to 300°C, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin B5. The obtained hydrogenated petroleum resin B5 has a softening point of 130°C, a ratio (M2 / M1) of 0.37, and an iodine value of 15.

[0126] (Example B6)

[0127] Except for replacing C9-based petroleum resin A1 with C9-based petroleum resin A5 and changing the reaction temperature to 300°C, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin B6. The obtained hydrogenated petroleum resin B6 has a softening point of 140°C, a ratio (M2 / M1) of 0.38, and an iodine value of 14.

[0128] (Example B7)

[0129] Except for replacing C9-based petroleum resin A1 with C9-based petroleum resin A6, the same reaction as in Example B1 was carried out to obtain hydrogenated petroleum resin B7. The obtained hydrogenated petroleum resin B7 has a softening point of 165°C, a ratio (M2 / M1) of 0.38, and an iodine value of 10.

[0130] [Table 4]

[0131] Hydrogenated petroleum resin B4 B5 B6 B7 Petroleum resin A3 A4 A5 A6 Softening point (°C) 90 130 140 165 <![CDATA[ratio (M2 / M1)]]> 0.36 0.37 0.38 0.38 <![CDATA[Iodine value (cgI2 / 100g)]]> 10 15 14 10 tone A A A A MACP (°C) -65 -67 -66 -67 XDCP (°C) 30 25 26 28

[0132] It should be noted that in Tables 3 and 4, "hue" indicates that cases with significant yellowing or other staining are rated C by visual inspection, while cases with almost no yellowing or other staining are rated A.

[0133] In addition, MACC (methylcyclohexane, aniline, cloud point determination) and XDCP (m-xylene, diacetone alcohol, cloud point determination) refer to values ​​determined by the following methods.

[0134] <MACP>

[0135] Dissolve 2g of sample in a solution containing 6ml of methylcyclohexane and 6ml of aniline by heating. While checking the temperature with a thermometer, gradually lower the temperature. Set the temperature at which the thermometer fogs up and becomes invisible as the MCP (°C).

[0136] It should be noted that MACC is a parameter representing compatibility with polyolefins; the lower the value, the higher the compatibility.

[0137] <XDCP>

[0138] Dissolve 2g of sample in a solution containing 7ml of m-xylene and 5ml of diacetone alcohol by heating. While checking the temperature with a thermometer, gradually lower the temperature. Set the temperature at which the thermometer fogs up and becomes invisible as XDCP (°C).

[0139] It should be noted that XDCP is a parameter representing the compatibility with aromatic resins (such as polystyrene), and the lower the value, the higher the compatibility.

[0140] (Example C1)

[0141] The hydrogenated petroleum resin B1 of Example B1 was used as a rubber additive, and the following tests were conducted.

[0142] <Preparation of Uncrosslinked Rubber Compositions>

[0143] The components shown in Table 5 were mixed in the proportions shown in Table 5 to obtain an uncrosslinked rubber composition. The mixing was performed using a Laboplastomill (manufactured by Toyo Seiki Co., Ltd.) and a rolling mill (manufactured by KNEADER MACHINERY Co., Ltd.). The mixing conditions were set as follows: initial temperature 135°C, rotation speed 50 rpm, and mixing time 8 minutes.

[0144] [Table 5]

[0145] SBR (oil-extended product) 70 BR 30 silicon dioxide 60 Hydrogenated petroleum resin B1 10 Si69 4.8 Oil (in oil-filled SBR) 26 Nocrac 6C 1.0 Zinc oxide 3.0 stearic acid 1.0 sulfur 1.0 Nocceler-D 1.0 Nocceler-CZ 2.3

[0146] It should be noted that the details of each component in Table 5 are as follows.

[0147] [Rubber Components]

[0148] • SBR: Tufdene E-581 (trade name), manufactured by Asahi Kasei Corporation, styrene-butadiene rubber. It should be noted that Tufdene E-581 is an oil-extended product. The SBR values ​​in Table 5 represent the net SBR content in the Tufdene E-581 blend, and the oil values ​​in Table 5 represent the net oil content in the Tufdene E-581 blend.

[0149] ·BR: Nipol BR1220 (trade name), manufactured by Zeon Corporation of Japan, butadiene rubber.

[0150] [Filling Material]

[0151] • Silica: Nipsil AQ (trade name), manufactured by Tosoh Corporation

[0152] [Silane coupling agent]

[0153] Si69: Cabrus4 (trade name), manufactured by Osaka Soda Co., Ltd.

[0154] [Vulcanization accelerator]

[0155] Nocceler-D (trade name): Manufactured by Ouchi Shinshin Chemical Industry Co., Ltd., diphenylguanidine

[0156] • Nocceler-CZ (trade name): Manufactured by Ouchi Shinshin Chemical Industry Co., Ltd., N-cyclohexyl-2-benzothiazole sulfenamide

[0157] [Vulcanization aids]

[0158] Zinc oxide: Manufactured by Hakusui Tech Co., Ltd.

[0159] Stearic acid: manufactured by New Nippon Rikka Co., Ltd.

[0160] Anti-aging agents

[0161] Nocrac 6C (trade name): Manufactured by Ouchi Shinshin Chemical Industry Co., Ltd.

[0162] [Cross-linking agent]

[0163] • Sulfur: HK200-5 (trade name), manufactured by Hosoi Chemical Industry Co., Ltd.

[0164] <Manufacturing of Crosslinked Rubber>

[0165] The uncrosslinked rubber composition obtained through mixing was heat-molded using a press (manufactured by DUMBBELL) to produce sheet-like crosslinked rubber. The heat-molding conditions were set at 160°C for 30 minutes, and the sheet was heated to a thickness of 1 mm.

[0166] <Viscoelasticity determination>

[0167] Samples were cut from the prepared sheet-like cross-linked rubber, measuring 1 mm in thickness, 5 mm in width, and 30 mm in length. The viscoelasticity of the cut samples was then measured. The viscoelasticity test conditions were as follows: the temperature was increased at a rate of 3 °C / min within a temperature range of -40 °C to 65 °C at a frequency of 10 Hz and a strain of 0.1%, while the measurement was performed in tensile mode. The apparatus used was a UBM Rheogel-E4000. The results are shown in Table 5.

[0168] The frequency is 10Hz because, when applying the time-temperature conversion law of viscoelasticity, wet grip performance is related to the tanδ value at 10Hz and 0℃; it is known that the larger this value, the better the wet grip. Similarly, rolling resistance is also related to the tanδ value at 10Hz and 60℃; it is known that the smaller this value, the better the rolling resistance characteristics.

[0169] (Example C2)

[0170] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B2, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 6.

[0171] (Comparative Example c1)

[0172] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A1, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 6.

[0173] [Table 6]

[0174] Types of resins B1 B2 A1 Softening point (°C) 125 125 125 <![CDATA[ratio (M2 / M1)]]> 0.33 0.20 - tanδ value at 0℃ 0.470 0.458 0.430 tanδ value at 60℃ 0.118 0.120 0.130 0℃ tanδ index 109 107 100 tanδ index at 60℃ 91 92 100 tanδ equilibrium index 120 115 100

[0175] It should be noted that in Table 6, the "0℃ tanδ index" represents the relative value when the "0℃ tanδ value" of Comparative Example c1 is set to 100. Additionally, in Table 6, the "60℃ tanδ index" represents the relative value when the "60℃ tanδ value" of Comparative Example c1 is set to 100. Furthermore, in Table 6, the "tanδ equilibrium index" represents the relative value of the ratio of the "0℃ tanδ value" to the "60℃ tanδ value" when the value of Comparative Example c1 is set to 100.

[0176] (Example D1)

[0177] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B3, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 7.

[0178] (Comparative Example d1)

[0179] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B3, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were performed in the same manner as in Example C1. The results are shown in 7.

[0180] (Comparative Example d2)

[0181] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A2, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 7.

[0182] [Table 7]

[0183] Types of resins B3 b3 A2 Softening point (°C) 105 105 105 <![CDATA[ratio (M2 / M1)]]> 0.35 0.09 - tanδ value at 0℃ 0.434 0.418 0.419 tanδ value at 60℃ 0.113 0.114 0.113 0℃ tanδ index 104 100 100 tanδ index at 60℃ 100 101 100 tanδ equilibrium index 104 99 100

[0184] (Example E1)

[0185] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B4, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 8.

[0186] (Comparative Example e1)

[0187] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A3, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 8.

[0188] [Table 8]

[0189] Types of resins B4 A3 Softening point (°C) 90 9O <![CDATA[ratio (M2 / M1)]]> 0.36 - tanδ value at 0℃ 0.439 0.422 tanδ value at 60℃ 0.113 0.112 0℃ tanδ index 104 100 tanδ index at 60℃ 101 100 tanδ equilibrium index 103 100

[0190] (Example F1)

[0191] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B5, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 9.

[0192] (Comparative example f1)

[0193] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A4, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 9.

[0194] [Table 9]

[0195] Types of resins B5 A4 Softening point (°C) 130 130 <![CDATA[ratio (M2 / M1)]]> 0.37 - tanδ value at 0℃ 0.459 0.431 tanδ value at 60℃ 0.120 0.119 0℃ tanδ index 106 100 tanδ index at 60℃ 101 100 tanδ equilibrium index 106 100

[0196] (Example G1)

[0197] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B6, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 10.

[0198] (Comparative example g1)

[0199] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A5, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 10.

[0200] [Table 10]

[0201] Types of resins B6 A5 Softening point (°C) 140 140 <![CDATA[ratio (M2 / M1)]]> 0.38 - tanδ value at 0℃ 0.454 0.439 tanδ value at 60℃ 0.126 0.127 0℃ tanδ index 103 100 tanδ index at 60℃ 99 100 tanδ equilibrium index 104 100

[0202] (Example H1)

[0203] Except for replacing hydrogenated petroleum resin B1 with hydrogenated petroleum resin B7, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 11.

[0204] (Comparative example h1)

[0205] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A6, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 11.

[0206] [Table 11]

[0207] Types of resins B7 A6 Softening point (°C) 165 165 <![CDATA[ratio (M2 / M1)]]> 0.38 - tanδ value at 0℃ 0.485 0.470 tanδ value at 60℃ 0.132 0.131 0℃ tanδ index 103 100 tanδ index at 60℃ 101 100 tanδ equilibrium index 102 100

[0208] (Example I1)

[0209] Except for the changes in the mixing ratios when manufacturing the uncrosslinked rubber composition as shown in Table 12 below, the manufacturing of the uncrosslinked rubber composition, the manufacturing of the crosslinked rubber, and the viscoelasticity determination were performed in the same manner as in Example C1. The results are shown in Table 13.

[0210] [Table 12]

[0211] SBR (oil-extended product) 70 BR 30 silicon dioxide 60 Hydrogenated petroleum resin B1 20 Si69 4.8 Oil (in oil-filled SBR) 26 Nocrac 6C 1.0 Zinc oxide 3.0 stearic acid 1.0 sulfur 1.0 Nocceler-D 1.0 Noccelcr-CZ 2.3

[0212] (Comparative Example i1)

[0213] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A1, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example H1. The results are shown in Table 13.

[0214] [Table 13]

[0215] Types of resins B1 A1 Softening point (°C) 125 125 <![CDATA[ratio (M2 / M1)]]> 0.33 - tanδ value at 0℃ 0.616 0.610 tanδ value at 60℃ 0.134 0.136 0℃ tanδ index 101 100 tanδ index at 60℃ 99 100 tanδ equilibrium index 102 100

[0216] (Example J1)

[0217] Except for changing the mixing ratio of the uncrosslinked rubber composition to Formulation C as described in Table 14 below, changing the mixing start temperature to 130°C, and changing the heat molding conditions for manufacturing the crosslinked rubber to 170°C and 40 minutes, the manufacturing of the uncrosslinked rubber composition, the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example C1. The results are shown in Table 15.

[0218] [Table 14]

[0219] SBR (oil-extended product) 100 silicon dioxide 100 Hydrogenated petroleum resin B1 10 Si69 8.0 Oil (in oil-filled SBR) 38 Nocrac 6C 1.0 Zinc oxide 3.0 stearic acid 1.0 sulfur 1.0 Nocceler-D 1.0 Nocceler-CZ 2.3

[0220] (Comparative Example j)

[0221] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A1, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example J1. The results are shown in Table 15.

[0222] [Table 15]

[0223] Types of resins B1 A1 Softening point (°C) 125 125 <![CDATA[Ratio (M2 / M1)]]> 0.33 - tanδ value at 20℃ 0.354 0.346 tanδ value at 60℃ 0.165 0.164 tanδ index at 20℃ 102 100 tanδ index at 60℃ 101 100 tanδ equilibrium index 102 100

[0224] It should be noted that formulation C in Table 14 is suitable for sports tires, racing tires, etc., and the results of the viscoelasticity test in Table 15 record the tanδ value at 20°C. The tanδ value at 20°C is related to the dry grip performance, which is important for sports tires, racing tires, etc. The larger the value, the better the dry grip performance.

[0225] In Table 15, the "20℃ tanδ index" represents the relative value when the "20℃ tanδ value" of Comparative Example j1 is set to 100. Additionally, in Table 15, the "60℃ tanδ index" represents the relative value when the "60℃ tanδ value" of Comparative Example j1 is set to 100. Furthermore, in Table 15, the "tanδ equilibrium index" represents the relative value of the ratio of the "20℃ tanδ value" to the "60℃ tanδ value" when the value of Comparative Example j1 is set to 100.

[0226] (Example K1)

[0227] Except for the changes in the mixing ratios when manufacturing the uncrosslinked rubber composition as shown in Table 16 below, the manufacturing of the uncrosslinked rubber composition, the crosslinked rubber, and the viscoelasticity determination were performed in the same manner as in Example J1. The results are shown in Table 17.

[0228] [Table 16]

[0229] SBR (oil-extended product) 100 silicon dioxide 100 Hydrogenated petroleum resin B1 20 Si69 8.0 Oil (in oil-filled SBR) 38 Nocrnc 6C 1.0 Zinc oxide 3.0 stearic acid 1.0 sulfur 1.0 NocccIcr-D 1.0 Nocceler-CZ 2.3

[0230] (Comparative example k1)

[0231] Except for replacing hydrogenated petroleum resin B1 with C9-based petroleum resin A1, the preparation of the uncrosslinked rubber composition, the preparation of the crosslinked rubber, and the viscoelasticity determination were carried out in the same manner as in Example K1. The results are shown in Table 17.

[0232] [Table 17]

[0233] Types of resins B1 A1 Softening point (°C) 125 125 <![CDATA[ratio (M2 / M1)]]> 0.33 - tanδ value at 20℃ 0.437 0.427 tanδ value at 60℃ 0.186 0.187 tanδ index at 20℃ 102 100 tanδ index at 60℃ 99 100 tanδ equilibrium index 103 100

[0234] It should be noted that formulation D in Table 16 is suitable for sports tires, racing tires, etc., and the results of the viscoelasticity test in Table 17 record the tanδ value at 20℃.

Claims

1. A hydrogenated petroleum resin, which is a hydrogenated form of C9 series petroleum resin. The C9-based petroleum resin is a resin formed by curing C9 fraction, or a resin formed by curing a mixture of C9 fraction and other hydrocarbons, wherein the C9 fraction in the mixture is 90% or more by mass. The ratio (M2 / M1) of the total number of hydrogen atoms bonded to the aromatic ring in the hydrogenated petroleum resin to the total number of hydrogen atoms in the hydrogenated petroleum resin is 0.2 to 0.

38.

2. The hydrogenated petroleum resin according to claim 1 has a softening point of 70~200℃.

3. The hydrogenated petroleum resin according to claim 1 or 2, wherein the iodine value is below 20.

4. An additive for rubber comprising the hydrogenated petroleum resin according to any one of claims 1 to 3.

5. An uncrosslinked rubber composition comprising a rubber component, the rubber additive of claim 4, and a crosslinking agent.

6. A crosslinked rubber, which is formed by crosslinking the uncrosslinked rubber composition of claim 5.

7. A tire having the cross-linked rubber of claim 6 in the tread portion.

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