Polymer composition and method for producing same, rubber composition and tire

Abstract

The purpose of the present invention is to provide: a polymer composition which exhibits excellent cold flow resistance and low viscosity; a method for manufacturing the same; a rubber composition containing the polymer composition; and a tire obtained using the rubber composition. In order to achieve the purpose, the present invention contains a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more and one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cyclic aliphatic resins. The content of the hydrogenated resin is 20 parts by mass or more with respect to 100 parts by mass of the high-molecular-weight polymer.

Description

Technical Field

[0001] The present disclosure relates to polymer compositions and methods for making the same, rubber compositions, and tires. Background Art

[0002] Polymers used in tire manufacturing can be relatively high molecular weight to meet various performance requirements. In this case, oil-added polymers with added processing oils are sometimes used to improve processability. In addition, polymers with added resins are sometimes used to improve both the tire's grip and its processability.

[0003] For example, JP2020-528487A (PTL 1) discloses a technique for reducing the adhesiveness of a composition by using a polymer to which a specific resin is added.

[0004] Citation List

[0005] Patent Literature

[0006] PTL 1: JP2020-528487A Summary of the invention

[0007] Problem that the invention aims to solve

[0008] However, polymers to which oil or resin is added, such as those exemplified in PTL 1, tend to cause a significant cold flow phenomenon, and improvement from this viewpoint has been sought.

[0009] Therefore, an object of the present invention is to provide a polymer composition having excellent cold flow resistance and low viscosity, a method for producing the same, a rubber composition containing the polymer composition, and a tire using the rubber composition.

[0010] Solutions for solving problems

[0011] The gist of the present disclosure is constructed as follows.

[0012] A polymer composition comprising a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more and one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, wherein the content of the hydrogenated resin is 20 parts by mass or more per 100 parts by mass of the high molecular weight polymer.

[0013] The above-mentioned constitution can provide a polymer composition having excellent cold flow resistance and low viscosity.

[0014] A method for producing a polymer composition, comprising mixing a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more with one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, wherein the amount of the hydrogenated resin blended is 20 parts by mass or more per 100 parts by mass of the high molecular weight polymer.

[0015] The above-mentioned constitution can provide a polymer composition having excellent cold flow resistance and low viscosity.

[0016] Effects of the Invention

[0017] The present disclosure can provide a polymer composition having excellent cold flow resistance and low viscosity, a method for producing the same, a rubber composition containing the polymer composition, and a tire using the rubber composition. DETAILED DESCRIPTION

[0018] <Polymer composition>

[0019] The polymer composition of the present disclosure comprises a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more and one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, wherein the content of the hydrogenated resin is 20 parts by mass or more relative to 100 parts by mass of the high molecular weight polymer.

[0020] Hereinafter, “a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more” may be referred to as a “high molecular weight polymer of the present disclosure”; and “one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins” may be referred to as a “hydrogenated resin of the present disclosure”.

[0021] Conventionally, high molecular weight polymers having rigidity, such as oil-extended styrene-butadiene copolymer rubber (oil-extended SBR) having a number average molecular weight of 500,000 g / mol or more, are sometimes mixed with oil or the like as a plasticizer to improve the processability of the polymer. However, when the high molecular weight polymer mixed with oil or the like is processed into sheets or blocks and stacked for storage, the high molecular weight polymer is easily deformed and flows (cold flow phenomenon).

[0022] In contrast, the polymer composition of the present disclosure has excellent cold flow resistance and low viscosity. The reason for this is not clear, but it is presumed to be due to the following reasons.

[0023] Since the hydrogenated aliphatic resin and the hydrogenated cycloaliphatic resin have low polarity, they are easily miscible with the high molecular weight polymer of the present disclosure, and it is believed that mixing the high molecular weight polymer with the hydrogenated resin can increase the glass transition temperature (Tg) of the polymer composition. Thus, it is believed that the deformation of the polymer composition can be suppressed, and the cold flow phenomenon can be suppressed. It is also believed that since the hydrogenated resin of the present disclosure is easily miscible with the high molecular weight polymer of the present disclosure, the viscosity of the polymer composition can be reduced.

[0024] In this way, the phenomenon that the high molecular weight polymer deforms and flows during storage, transportation, etc. (cold flow phenomenon) can be suppressed, and the increase in viscosity can be suppressed. This leads to excellent processability of the polymer composition and excellent processability when the polymer composition is mixed with a rubber component and the like to perform a kneading process on the rubber composition.

[0025] The following is a detailed description of the ingredients of the polymer composition.

[0026] [High molecular weight polymer]

[0027] The high molecular weight polymer of the present disclosure has a number average molecular weight of 500,000 g / mol or more.

[0028] Hereinafter, the last three digits of a molecular weight ",000" are represented by "k", and 500,000 may be described as "500k".

[0029] In the present disclosure, the number average molecular weight (Mn) refers to the polystyrene equivalent number average molecular weight measured by gel permeation chromatography (GPC).

[0030] The number average molecular weight of the high molecular weight polymer is preferably greater than 500,000 (500k) g / mol, more preferably greater than 700,000 (700k) g / mol, and even more preferably greater than 1,000,000 (1000k) g / mol. The number average molecular weight of the high molecular weight polymer is preferably 3,000,000 (3000k) g / mol or less, more preferably 2,000,000 (2000k) g / mol or less, and even more preferably 1,500,000 (1500k) g / mol or less.

[0031] From the viewpoint of balancing the heat buildup property of the polymer composition with the wet road performance and wear resistance, the glass transition temperature (Tg) of the high molecular weight polymer is preferably -30°C or lower, more preferably -45°C or lower, and even more preferably -60°C or lower. The glass transition temperature (Tg) of the high molecular weight polymer is preferably -80°C or higher.

[0032] The Tg of high molecular weight polymers can be measured by differential scanning calorimetry (DSC).

[0033] The high molecular weight polymer is preferably modified. In other words, the high molecular weight polymer preferably has a modified functional group in the molecular chain.

[0034] By modifying the high molecular weight polymer, when the rubber composition containing the polymer composition of the present disclosure contains a filler, the filler dispersibility is improved, and a vulcanized rubber having low heat generation and excellent breaking properties and wear resistance can be obtained.

[0035] The high molecular weight polymer can be modified with a modifier such as an alkoxysilane compound, an amine compound or a tin compound. Only one modifier can be used, or two or more modifiers can be used. By using these modifiers, the high molecular weight polymer can have a modified functional group in the molecular chain, such as an alkoxysilane group; a primary, secondary or tertiary amino group or a group containing a tin atom. In addition, the primary amino group and the secondary amino group can be protected by a hydrolyzable protective group. The high molecular weight polymer can have only one or more modified functional groups. Among them, the high molecular weight polymer preferably has at least an alkoxysilane group in the molecular chain, and more preferably has an amino group in addition.

[0036] The type of the high molecular weight polymer is not limited, and olefin polymers, ester polymers, amide polymers, urethane polymers, diene polymers and the like can be used, among which diene polymers are preferred.

[0037] Examples of diene polymers include polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), butadiene polymer (BR), ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), halogenated butyl rubber, acrylonitrile-butadiene rubber (NBR). SBR, BR and IR may also be hydrogenated.

[0038] Only one kind of high molecular weight polymer may be used or two or more kinds of high molecular weight polymer may be used.

[0039] Among them, the high molecular weight polymer of the present disclosure preferably contains styrene-butadiene copolymer rubber (SBR), and more preferably consists of styrene-butadiene copolymer rubber (SBR).

[0040] When a diene polymer is used as the high molecular weight polymer, from the viewpoint of low loss and WET performance of a tire obtained from a rubber composition comprising the polymer composition of the present disclosure, the vinyl bond content (Vi) in the diene compound portion of the diene polymer is preferably 10 mol% to 70 mol%, more preferably 15 mol% to 60 mol%, and even more preferably 20 mol% to 50 mol%.

[0041] The vinyl bond content of the diene polymer can be determined by 1 H-NMR spectroscopy determination.

[0042] When a modified or unmodified SBR is used as the high molecular weight polymer, from the viewpoint of low loss and WET performance of a tire obtained from a rubber composition comprising the polymer composition of the present disclosure, the bound styrene content (St) of the modified or unmodified SBR is preferably 3 mol% to 25 mol%, more preferably 4 mol% to 22 mol%, and even more preferably 5 mol% to 18 mol%.

[0043] The bound styrene content of modified or unmodified SBR can be determined by 1 H-NMR spectroscopy determination.

[0044] [Hydrogenated resin]

[0045] The polymer composition contains one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, and the content of the hydrogenated resin in the polymer composition is 20 parts by mass or more per 100 parts by mass of the high molecular weight polymer.

[0046] If the content of the hydrogenated resin in the polymer composition is less than 20 parts by mass relative to 100 parts by mass of the high molecular weight polymer, the cold flow phenomenon of the polymer composition cannot be suppressed. From the viewpoint of further improving the cold flow resistance of the polymer composition, the content of the hydrogenated resin in the polymer composition is preferably 30 parts by mass or more, more preferably 35 parts by mass or more, and even more preferably 50 parts by mass or more relative to 100 parts by mass of the high molecular weight polymer.

[0047] The content of the hydrogenated resin in the polymer composition is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less, relative to 100 parts by mass of the high molecular weight polymer.

[0048] (Hydrogenated aliphatic resin)

[0049] Examples of hydrogenated aliphatic resins include hydrogenated non-cyclic aliphatic resins such as C 5 It is a resin.

[0050] Only one kind of hydrogenated aliphatic resin may be used, or two or more kinds may be used.

[0051] C 5 Examples of C-based resins include those obtained by thermal cracking of naphtha from the petrochemical industry or from plant resources. 5 Aliphatic resin obtained by fraction (co)polymerization.

[0052] C 5The fractions generally include olefins such as 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene or 3-methyl-1-butene; diolefins such as 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene or 3-methyl-1,2-butadiene; and the like. 5 It is a resin, and a commercially available product can be used.

[0053] (Hydrogenated Cycloaliphatic Resin)

[0054] Examples of hydrogenated cycloaliphatic resins include C 5 -C 9 Resin, C 9 Series resins, dicyclopentadiene series resins, terpene series resins, terpene aromatic compound series resins, hydrogenated rosin series resins and other hydrogenated cyclic aliphatic resins.

[0055] One of these hydrogenated cycloaliphatic resins may be used alone, or two or more thereof may be used in combination.

[0056] C 5 -C 9 Examples of the system resin include those obtained by using a Friedel-Crafts catalyst such as AlCl 3 or BF 3 Polymer C 5 -C 11 The solid polymer obtained by fractionation. 5 -C 9 Specific examples of the olefin-based resin include copolymers having styrene, vinyltoluene, α-methylstyrene, indene, and the like as a main component.

[0057] As C 5 -C 9 The resin is preferably C 9 Here, "C 9 The above ingredients are less "refers to the total amount of C in the resin 9 The amount of the above components is less than 50% by mass, preferably less than 40% by mass. 5 -C 9 It is a resin, and a commercially available product can be used.

[0058] C 9 The resin is obtained by using a Friedel-Crafts catalyst such as AlCl 3 or BF 3 Polymer C 9 The solid polymer is obtained by distillation.

[0059] C 9Examples of the indene-based resin include copolymers containing indene, α-methylstyrene, vinyltoluene, etc. as a main component.

[0060] Dicyclopentadiene resin (DCPD resin) refers to a resin obtained by using a Friedel-Crafts catalyst such as AlCl 3 or BF 3 A resin obtained by polymerizing dicyclopentadiene.

[0061] Terpene resin is a solid resin obtained by mixing turpentine obtained from pine trees while obtaining rosin or polymerizable components separated from turpentine, and then polymerizing turpentine or polymerizable components using Friedel-Crafts catalyst. Examples of terpene resins include β-pinene resin and α-pinene resin. A typical example of terpene aromatic compound resin is terpene phenol resin. Terpene phenol resin can be obtained by various methods, including using Friedel-Crafts catalyst to react terpenoids and various phenols with each other, or further condensing the resultant with formalin. The terpene of the raw material is not limited, but preferably monoterpene hydrocarbons such as α-pinene and limonene, more preferably terpene containing α-pinene, and particularly preferably α-pinene. Styrene and the like can be included in the skeleton.

[0062] In addition, as the cycloaliphatic resin, a cycloaliphatic resin obtained by using C 5 The resin (C 5 -DCPD based resin).

[0063] Here, when the dicyclopentadiene-derived component in the total resin content is 50% by mass or more, the dicyclopentadiene-based resin should contain C 5 -DCPD-based resin. When the dicyclopentadiene-derived component in the total resin content is less than 50% by mass, C 5 The resin should contain C 5 -DCPD-based resin. This also applies to the case where a small amount of a third component is contained.

[0064] Among them, the hydrogenated resin more preferably comprises a hydrogenated C 5 Resin, hydrogenated C 5 -C 9 Resin, hydrogenated C 9 At least one of a series resin and a hydrogenated dicyclopentadiene series resin.

[0065] From the viewpoint of processability of the polymer composition, the softening point (Ts) of the hydrogenated resin is preferably between 100°C and 150°C, more preferably between 105°C and 145°C, even more preferably between 110°C and 140°C.

[0066] From the viewpoint of improving the cold flow resistance of the polymer composition, the glass transition temperature (Tg) of the hydrogenated resin is preferably between 60°C and 95°C, more preferably between 63°C and 92°C, even more preferably between 60°C and 90°C.

[0067] The ratio of the glass transition temperature (°C) to the softening point (°C) (glass transition temperature / softening point) (Tg / Ts) of the hydrogenated resin is preferably 0.5 or more. When the Tg / Ts of the hydrogenated resin is 0.5 or more, the cold flow resistance of the polymer composition can be further improved. The Tg / Ts of the hydrogenated resin is more preferably 0.53 or more, and even more preferably 0.55 or more. In addition, from the viewpoint of the processability of the polymer composition, the Tg / Ts of the hydrogenated resin is preferably 0.75 or less, more preferably 0.72 or less, and even more preferably 0.68 or less.

[0068] The softening point of the hydrogenated resin can be measured according to JIS-K2207-1996 (ring and ball method), and the glass transition temperature of the hydrogenated resin can be measured by a differential scanning calorimeter (DSC).

[0069] The number average molecular weight (Mn) of the hydrogenated resin is preferably 300 g / mol or more. When the number average molecular weight of the hydrogenated resin is 300 g / mol or more, the bleed-out of low molecular weight resin from the polymer composition can be suppressed.

[0070] As described above, the number average molecular weight (Mn) refers to the polystyrene equivalent number average molecular weight measured by gel permeation chromatography (GPC).

[0071] The number average molecular weight of the hydrogenated resin is more preferably 320 g / mol or more, even more preferably 330 g / mol or more.The number average molecular weight of the hydrogenated resin is preferably 1000 g / mol or less, more preferably 900 g / mol or less, even more preferably 860 g / mol or less.

[0072] From the viewpoint of compatibility with a high molecular weight polymer, the weight average molecular weight (Mw) of the hydrogenated resin is preferably 300 to 2500 g / mol, more preferably 350 to 2300 g / mol, even more preferably 400 to 2100 g / mol.

[0073] The weight average molecular weight (Mw) refers to the polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (GPC).

[0074] The molecular weight distribution (MWD) of the hydrogenated resin is preferably from 1.30 to 2.50, more preferably from 1.40 to 2.40, even more preferably from 1.50 to 2.30, from the viewpoint of compatibility with the high molecular weight polymer.

[0075] The molecular weight distribution (MWD) of the hydrogenated resin can be calculated from the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn).

[0076] Although the polymer composition may further contain components other than the high molecular weight polymer of the present disclosure and the hydrogenated resin of the present disclosure, the polymer composition is preferably composed of the high molecular weight polymer of the present disclosure and the hydrogenated resin of the present disclosure from the viewpoint of further improving the cold flow resistance of the polymer composition.

[0077] As described above, when the polymer composition includes the high molecular weight polymer of the present disclosure and a given amount of the hydrogenated resin of the present disclosure, the glass transition temperature of the polymer composition may be increased, thereby suppressing the cold flow phenomenon.

[0078] The glass transition temperature of the polymer composition can be measured by differential scanning calorimetry (DSC).

[0079] <Method for producing polymer composition>

[0080] The method for producing a polymer composition comprises mixing a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more with one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, wherein the blending amount of the hydrogenated resin is 20 parts by mass or more relative to 100 parts by mass of the high molecular weight polymer.

[0081] As the high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more, the polymers described as the high molecular weight polymer of the present disclosure can be used, and the preferred aspects are the same. In addition, examples of the hydrogenated resin include the hydrogenated resins described as the hydrogenated resin of the present disclosure, and the preferred aspects are the same.

[0082] From the viewpoint of further improving the cold flow resistance of the manufactured polymer composition, the compounding amount of the hydrogenated resin of the present disclosure is preferably 30 parts by mass or more, more preferably 35 parts by mass or more, and even more preferably 50 parts by mass or more, relative to 100 parts by mass of the high molecular weight polymer; and is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less, relative to 100 parts by mass of the high molecular weight polymer.

[0083] <Rubber composition>

[0084] The rubber composition of the present disclosure includes the polymer composition of the present disclosure.

[0085] The rubber composition of the present disclosure may contain, as a rubber component, a diene rubber such as natural rubber, isoprene rubber, butadiene rubber, etc. When the high molecular weight polymer of the present disclosure is a diene polymer, the polymer composition of the present disclosure may be used as a rubber component.

[0086] In addition to the polymer composition of the present disclosure, the rubber composition of the present disclosure may include inorganic fillers such as carbon black and silica; softeners; antioxidants; vulcanization accelerators such as sulfenamide-based vulcanization accelerators and thiuram-based vulcanization accelerators; stearic acid; zinc oxide; a vulcanizing agent, etc.

[0087] <Tires>

[0088] The tire of the present disclosure is formed using the rubber composition of the present disclosure.

[0089] Depending on the type or member of the tire to be applied, the tire can be obtained by vulcanizing after molding the unvulcanized rubber composition, or can be obtained by first preparing a semi-vulcanized rubber from the unvulcanized rubber composition by a pre-vulcanization process, etc., molding using the semi-vulcanized rubber, and then separately performing main vulcanization. As the gas for filling the tire, an inert gas such as nitrogen, argon or helium as well as normal air or air whose oxygen partial pressure has been adjusted can be used.

[0090] The tire of the present disclosure can be used as various tires, such as tires for passenger cars, light trucks, aircraft, and racing cars, but is particularly suitable for use as a tire for passenger cars.

[0091] The various components (resins, rubbers, various additives, etc.) contained in the polymer compositions, rubber compositions, and tires described herein may be partially or completely derived from fossil resources, biological resources such as plant resources, or recycled resources such as scrap tires. They may also be derived from a mixture of two or more of fossil resources, biological resources, and recycled resources.

[0092] Example

[0093] The presently disclosed technology will be described in more detail below through examples, although these examples are intended for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.

[0094] <Examples 1 to 4 and Comparative Examples 1 to 5>

[0095] (High molecular weight polymer)

[0096] 1) Modified SBR: modified styrene-butadiene copolymer rubber synthesized by synthesis method 1

[0097] 2) Unmodified SBR: Unmodified styrene-butadiene copolymer rubber (resin) synthesized by synthesis method 2

[0098] C5 Resin: Trade name "Quintone A100" manufactured by Zeon Corporation

[0099] C 9 Resin: Trade name "Nisseki Neopolymer 140" manufactured by ENEOS Corporation

[0100] Hydrogenated DCPD-based resin: Trade name "T-REZ HA125" manufactured by ENEOS Corporation

[0101] Hydrogenated C 9 Series resin: trade name "NS045Alcon M-135" manufactured by Arakawa Chemical Industries, Ltd.

[0102] (Synthesis Method 1)

[0103] Cyclohexane (200 g), butadiene / cyclohexane solution (25% by mass, 216 g) and styrene (6 g) were added to a glass bottle under an inert atmosphere and mixed, followed by the addition of 2,2-di-(2-tetrahydrofuranyl)propane / cyclohexane solution (0.2 M, 0.18 mL) and n-butyl lithium solution (1.6 M, 0.19 mL). The mixture was gently shaken at 50° C. for 4 hours, followed by the addition of 0.3 mol of N,N-bis(trimethylsilyl)-(3-amino-1-propyl)](methyl)(diethoxy)silane. It was then infiltrated at 50° C. for another 30 minutes. The reaction was then completely terminated by adding an appropriate amount of degassed isopropanol to the glass bottle, and 0.6 mL of an isopropanol solution (5% by mass) of 2,6-di-tert-butyl-p-cresol was added to the resulting polymer mortar.

[0104] Take out a portion of the polymer paste from 1 The molecular characteristics of the polymer (modified SBR) were examined by integrating the H-NMR. The bound styrene content (St) of the polymer was 11%, and the vinyl bond content (Vi) of the butadiene part was 47 mol%.

[0105] The number average molecular weight of the polymer (modified SBR) was measured using gel permeation chromatography and found to be 612,000 (612 k) g / mol from the viewpoint of monodisperse polystyrene.

[0106] (Synthesis Method 2)

[0107] Cyclohexane (300 g), butadiene / cyclohexane solution (25% by mass, 108 g) and styrene (3 g) were added to a glass bottle under an inert atmosphere and mixed, and then 2,2-di-(2-tetrahydrofuranyl) propane / cyclohexane solution (0.2 M, 0.10 mL) and cyclohexane solution containing 1,3-bis(1-lithio-1,3-dimethylpentyl) benzene (0.15 M, 0.76 mL) were added. The mixture was gently shaken at 50° C. for 10 hours, and then an appropriate amount of degassed isopropanol was added to the glass bottle to terminate the polymerization. 0.3 mL of an isopropanol solution (5% by mass) of 2,6-di-tert-butyl-p-cresol was added to the resulting polymer mortar.

[0108] Take out a portion of the polymer paste from 1 The molecular characteristics of the polymer (unmodified SBR) were examined by integration ratio of H-NMR. The bound styrene content (St) of the polymer was 11%, and the vinyl bond content (Vi) of the butadiene part was 45 mol%.

[0109] The number average molecular weight of the polymer (unmodified SBR) was measured by gel permeation chromatography and was found to be 1,140,000 (1140 k) g / mol from the viewpoint of monodisperse polystyrene.

[0110] [[Preparation of polymer composition]]

[0111] The polymer cements (containing 30 g of polymer) obtained by Synthesis Methods 1 and 2 were mixed with THF solutions containing 15 g of each resin (30 g in Comparative Example 5) and shaken for 30 minutes. The obtained polymer cements were reprecipitated with isopropanol and dried under reduced pressure to obtain polymer compositions.

[0112] In Tables 1 and 2, the compounding unit of each component is [parts by mass].

[0113] For example, in Table 1, Comparative Example 1 refers to a modified SBR having a bound styrene content (St) of 11%, a vinyl bond content (Vi) of 47 mol% in the butadiene portion, a number average molecular weight (Mn) of 612,000 (612k) g / mol, and a glass transition temperature (Tg) of -54°C, and a modified SBR having a number average molecular weight (Mn) of 684 g / mol, a weight average molecular weight (Mw) of 3939 g / mol, a molecular weight distribution (MWD) of 5.76, a glass transition temperature (Tg) of 48°C, and a softening point (Ts) of 100°C. 5 It is prepared by mixing resins.

[0114] [Mn, Mw, MWD, Tg, Ts of resin]

[0115] The number average molecular weight (Mn), weight average molecular weight (Mw), molecular weight distribution (MWD), glass transition temperature (Tg), and softening point (Ts) of each resin listed in Table 1 were measured by the following methods.

[0116] (Number average molecular weight, weight average molecular weight, molecular weight distribution)

[0117] The sample was prepared by dissolving about 2.5 mg of the resin component in 10 mL of tetrahydrofuran. The obtained sample was used to measure the average molecular weight of the hydrogenated resin by gel permeation chromatography (GPC) under the following conditions, and the polystyrene equivalent number average molecular weight (Mn) and weight average molecular weight (Mw) were calculated. MWD was calculated by Mw / Mn.

[0118] Column temperature: 40℃

[0119] Injection volume: 50μL

[0120] Carrier and flow rate: Tetrahydrofuran 0.6mL / min

[0121] (Glass transition temperature)

[0122] The glass transition temperature of the resin was measured by differential scanning calorimetry (DSC).

[0123] Specifically, according to ISO 22768:2006, a differential scanning calorimeter "DSC2500" manufactured by TA Instruments Japan Inc. was used to record a DSC curve while heating from -100°C at 10°C / min under a helium flow of 50 mL / min, and the peak top (inflection point) of the DSC differential curve was taken as the glass transition temperature.

[0124] (Softening point)

[0125] The softening point of the resin is measured in accordance with JIS-K2207-1996 (ring and ball method).

[0126] [[Evaluation of polymer composition]]

[0127] 1. Viscosity of polymer composition (G')

[0128] Using "RPA2000" manufactured by Alpha Technologies, each polymer composition was preheated at 60°C (0.2 minutes after stabilization at 60°C), and then the dynamic measurement of the polymer composition was performed from 60°C to 130°C at 10°C increments under the conditions of a frequency of 1 Hz and a strain of 100%. The measured viscosity (G') values ​​were indexed with the viscosity of Comparative Example 1 being set to 100 in Table 1 and the viscosity of Comparative Example 3 being set to 100 in Table 2. The smaller the index value, the lower the viscosity of the polymer composition.

[0129] 2. Cold flow resistance of polymer compositions

[0130] According to JIS K-6300-1:2001, the polymer composition is heated at a test temperature of 80°C using an L-shaped rotor with a preheating time of 1 minute and a rotor rotation time of 4 minutes to determine ML 1+4 In ML 1+4 Stop the L-shaped rotor immediately after measurement and 1+4 The time (in seconds) required for the value to decrease by 80% is defined as T80. In Table 1, the measured values ​​are indexed by setting the value of Comparative Example 1 to 100. In Table 2, the measured values ​​are indexed by setting the value of Comparative Example 3 to 100. A larger index value indicates that the cold flow resistance of the polymer composition is better.

[0131] [Table 1]

[0132]

[0133] [Table 2]

[0134]

[0135] The results of the Examples and Comparative Examples listed in Tables 1 and 2 indicate that the polymer composition according to the present disclosure can suppress the cold flow phenomenon and reduce the viscosity.

[0136] On the other hand, among the polymer compositions of Comparative Examples 1 to 5 not containing hydrogenated resin, some compositions (Comparative Examples 2 and 4) have improved cold flow resistance, but none of them can achieve a reduction in viscosity, and therefore cannot simultaneously achieve a reduction in viscosity and an improvement in cold flow resistance.

[0137] Industrial Applicability

[0138] The polymer composition of the present disclosure can be suitably used as a component of a rubber composition, which can be suitably used in various vulcanized rubber products, such as hoses and belts, and tires for passenger cars and trucks. Among the above, the rubber composition is suitable for manufacturing tires for passenger cars.

Claims

1. A polymer composition comprising a high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more and one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, wherein the content of the hydrogenated resin is 20 parts by mass or more relative to 100 parts by mass of the high molecular weight polymer.

2. The polymer composition according to claim 1, wherein the glass transition temperature (Tg) of the high molecular weight polymer is -30°C or lower.

3. The polymer composition according to claim 1 or 2, wherein the high molecular weight polymer is modified. 4 . The polymer composition according to claim 1 , wherein the hydrogenated resin comprises at least one selected from the group consisting of hydrogenated C5-based resins, hydrogenated C5-C9-based resins, hydrogenated C9-based resins, and hydrogenated dicyclopentadiene-based resins. 5 . The polymer composition according to claim 1 , wherein the ratio of the glass transition temperature (° C.) to the softening point (° C.) of the hydrogenated resin, that is, glass transition temperature / softening point, is 0.5 or more. 6 . The polymer composition according to claim 1 , wherein the number average molecular weight of the hydrogenated resin is 300 g / mol or more.

7. The polymer composition according to claim 2, wherein the glass transition temperature of the high molecular weight polymer is -60°C or lower.

8. A method for producing a polymer composition, wherein A high molecular weight polymer having a number average molecular weight of 500,000 g / mol or more is mixed with one or more hydrogenated resins selected from the group consisting of hydrogenated aliphatic resins and hydrogenated cycloaliphatic resins, wherein The amount of the hydrogenated resin blended is 20 parts by mass or more per 100 parts by mass of the high molecular weight polymer.

9. A rubber composition comprising the polymer composition according to claim 1 or 2. 10 . A tire using the rubber composition according to claim 9 .

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