Functionalized carbon black, its preparation and use in vulcanizable rubber compositions

Abstract

The present disclosure provides functionalized carbon black obtained by treating oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof. The disclosure also relates to a method for producing such functionalized carbon black. Furthermore, the disclosure relates to a vulcanizable rubber composition comprising (i) a vulcanizable rubber component and (ii) oxidized carbon black and (iii) a sulfur-containing primary or secondary amine or a salt thereof, or a functionalized carbon black formed from these components. The disclosure also relates to articles produced from the vulcanizable rubber composition. The functionalized carbon black disclosed herein is particularly useful for obtaining rubber compounds with low hysteresis and improved wear resistance, for example, for the production of energy-saving tires.

Description

[Technical Field]

[0001] This disclosure relates to functionalized carbon black, related vulcanizable rubber compositions and articles manufactured therefrom, and the preparation processes for each. More specifically, this disclosure relates to functionalized carbon black that can be obtained by treating oxidized carbon black with a sulfur-containing amine. Functionalized carbon black is particularly useful, for example in tire applications, for obtaining rubber products with reduced hysteresis and good wear resistance. [Background technology]

[0002] Carbon black is included in many rubber-based compounds, for example, to modify their color, mechanical, electrical, and / or processing properties. For example, carbon black is commonly added to rubber compositions used to manufacture tires or their components to impart electrical dissipation to the insulating matrix. At the same time, carbon black additives affect mechanical and elastic properties such as stiffness, wear resistance, and hysteresis, which greatly influence the performance of the resulting tire, for example, in terms of its rolling resistance and durability. Here, carbon black tends to form a network structure in the matrix through strong filler-filler interactions, which are the main source of heat accumulation in the rubber components. Due to regulatory requirements and increasing environmental impact, there is a growing demand for energy-saving tires with low rolling resistance. At the same time, other performance parameters such as grip, traction, and durability must not be negatively affected. This often represents conflicting requirements.

[0003] One option for reducing the energy lost in the form of heat during deformation of rubber materials, which is reflected by lower values ​​of hysteresis, is to reduce the filler-filler interaction by increasing the interaction between the carbon black filler and the rubber matrix. Hysteresis can also be reduced by decreasing the amount of carbon black loaded and / or increasing the particle size of the carbon black. However, this may simultaneously degrade electrical dissipation and / or mechanical properties such as abrasion resistance, fracture resistance or chipping resistance.

[0004] Alternatively, developments have been made to chemically modify rubber materials and / or carbon black fillers to enhance the filler-rubber interaction.

[0005] For example, U.S. Patent No. 5,248,722 describes an elastomer composition with reduced rolling resistance in tire tread applications by utilizing a terminally functionalized polymer in combination with acid-functionalized oxidized carbon black. However, terminally functionalized polymers are not readily available and require specialized processes to be prepared by reacting a polymer prepared by polymerization of at least one diene monomer and optionally one or more vinyl-substituted aromatic monomers with a tin or nitrogen-containing compound.

[0006] According to International Publication No. 2011 / 028337, using surface-treated carbon black in combination with functionalized SBR polymers functionalized with oxygen-containing groups such as carboxylic acids or hydroxyl groups along the chain enhances carbon black-elastomer interactions, resulting in reduced hysteresis and improved wet traction compared to the use of conventional carbon black-containing compounds. However, this approach also requires the use of specialized polymer materials.

[0007] EP3339364 proposes using carbon oxide black in combination with a polymer amine having a primary amine functional group such as polyethyleneimine to obtain a rubber compound with improved hysteresis for tires with low rolling resistance. However, the abrasion resistance is somewhat degraded in the resulting rubber compound.

[0008] However, for example, to manufacture tires with low rolling resistance and good durability, it is desirable to provide rubber compounds that exhibit improved hysteresis and, at the same time, improved wear resistance. The remaining mechanical properties of such rubber compounds should be suitable for tire applications.

[0009] Therefore, an object of the present invention is to provide a functionalized carbon black that can impart the above properties to rubber compounds while mitigating or avoiding the drawbacks of the prior art. The functionalization of carbon black should be achievable in an efficient and economical manner using readily available components and processing techniques. The present invention aims to provide a vulcanizable rubber composition that provides both improved hysteresis and enhanced wear resistance suitable for tire manufacturing. [Overview of the project]

[0010] Surprisingly, it was found that the above objectives could be achieved by functionalized carbon black obtained by treating oxidized carbon black with sulfur-containing primary or secondary amines or salts thereof.

[0011] The functionalized carbon black of the present invention can be obtained by a method comprising the following: (A) To provide oxidized carbon black, (B) Contacting carbon black oxide with a sulfur-containing primary or secondary amine or a salt thereof. (C) Expose the resulting mixture to conditions under which the carbon black oxide reacts with a sulfur-containing primary or secondary amine or a salt thereof.

[0012] Here, the functionalized carbon black according to the present invention may be treated with a sulfur-containing primary or secondary amine or a salt thereof during the preparation of the vulcanizable rubber composition, either in situ or separately, for example, to obtain such a functionalized carbon black material.

[0013] The present invention accordingly also relates to a vulcanizable rubber composition comprising the following: (i) A vulcanizable rubber component, (ii) Carbon black oxide, and (iii) A sulfur-containing primary or secondary amine or a salt thereof, Or, A vulcanizable rubber component (i), and the functionalized carbon black according to the present invention formed from carbon black oxide (ii) and a sulfur-containing primary or secondary amine or a salt thereof (iii).

[0014] Articles produced from the vulcanizable rubber composition of the present invention are also within the scope of the present invention.

[0015] Furthermore, the present invention generally relates to the use of a sulfur-containing primary or secondary amine or a salt thereof for surface modification of carbon black oxide and / or as a coupling agent in a carbon black-containing vulcanizable rubber composition.

[0016] The functionalized carbon black according to the present invention can be obtained at low cost by an efficient method from commercially available components using common processing techniques. They impart a favorable combination of properties to the rubber compounds to which they are added or in which they are formed, particularly resulting in a significantly reduced hysteresis and improved abrasion resistance, which has been found to be particularly interesting for the production of energy-saving tires.

[0017] While not intended to be bound by any particular theory, it is believed that by using sulfur-containing primary or secondary amines, their bifunctionality—that is, sulfur functionality and amine functionality with one or more NH moieties—can form strong interactions, for example, via covalent and / or hydrogen bonds, with oxidized carbon black, which generally has polar oxygen-containing groups on its surface, on the one hand, and with vulcanizable rubber components, which generally contain vulcanizable moieties such as ethylenically unsaturated groups that have an affinity for sulfur-containing moieties, on the other hand. Therefore, effective coupling of functionalized carbon black to rubber components can be achieved, efficiently reducing filler-filler interactions and yielding rubber compounds with low hysteresis and high durability and mechanical rigidity.

[0018] Accordingly, the present invention also relates to the use of sulfur-containing primary or secondary amines or salts thereof in a carbon black-containing vulcanizable rubber composition, for the purpose of reducing the loss factor tanδ (e.g., measured at 60°C), and / or reducing heat accumulation, and / or increasing the binding rubber content, and / or improving abrasion resistance, compared to a corresponding carbon black-containing vulcanizable rubber composition that does not contain sulfur-containing primary or secondary amines or functionalized carbon black derived therefrom.

[0019] These and any other features and advantages of the present invention will be described in more detail in the following description. [Modes for carrying out the invention]

[0020] As used herein, the term "contains" is understood to be open-ended and not to exclude the presence of additional unspecified or unenumerated elements, materials, components, or method steps. The terms "include," "contain," and similar terms are understood to be synonymous with "contains." As used herein, the term "consists of" is understood to exclude the presence of any unspecified elements, components, or method steps.

[0021] As used herein, the singular forms of “a,” “an,” and “the” encompass multiple referents unless the context clearly indicates otherwise.

[0022] Unless otherwise noted, the numerical parameters and ranges described in the following specification and the attached claims are approximate. While the broad ranges and parameters of the present invention are approximate, the numerical values ​​shown in the specific examples are reported as accurately as possible. However, any numerical values ​​will inevitably contain errors arising from the standard deviation in their respective measurements.

[0023] Furthermore, it should be understood that any numerical range listed herein is intended to encompass all subranges belonging to it. For example, the range "1 to 10" is intended to encompass all subranges between the listed minimum value of 1 and the listed maximum value of 10, and any subranges encompassing them, i.e., all subranges starting with a minimum value of 1 or greater and ending with a maximum value of 10 or less, and all subranges between, for example, 1 to 6.3, or 5.5 to 10, or 2.7 to 6.1.

[0024] As described above, the present invention relates to functionalized carbon black obtained by treating oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof.

[0025] As used herein, “carbon black” is a material consisting substantially of 90% or more by weight of carbon, for example, based on its total weight, produced by controlled partial pyrolysis of one or more hydrocarbon precursors. Various industrial methods for producing carbon black materials are known, such as furnace processes, gas black processes, acetylene black processes, thermal black processes, or lamp black processes. The production of carbon black is well known in the art itself, and is outlined, for example, in J.-B. Donnet et al., “Carbon Black: Science and Technology,” 2nd edition, and therefore will not be described in further detail here. The carbon black used in the implementation of the present invention may also include mixtures of two or more different carbon black grades.

[0026] The term "oxidized carbon black," as used herein, refers to carbon black that has been subjected to oxidation and therefore contains oxygen-containing functional groups. Oxygen-containing functional groups can be present, in particular, on the surface of carbon black particles. Examples of oxygen-containing functional groups include, but are not limited to, quinone groups, carboxyl groups, phenol groups, lactol groups, lactone groups, anhydride groups, and ketone groups. In this specification, carboxylic acid groups or anhydride groups on the surface of carbon black particles are considered particularly preferable for forming strong interactions with sulfur-containing amine components due to the ability of these polar groups to form relatively strong bonds, for example, through salt formation, hydrogen bonding, or reactions that form covalent amide bonds.

[0027] Suitable oxidized carbon blacks for implementation of the present invention can be produced by any method that is conventionally known in the art of carbon black oxidation and is disclosed, for example, in U.S. Patent No. 6,120,594 and U.S. Patent No. 6,471,933. Suitable methods include, for example, oxidation of the carbon black material using oxidizing agents such as peroxides like hydrogen peroxide, persulfates like sodium persulfate and potassium persulfate, hypohalites like sodium hypochlorite, ozone gas or oxygen gas, transition metal-containing oxidizing agents such as permanganates, osmium tetroxide, chromium oxide, cerium ammonium nitrate, or oxidizing acids such as nitric acid and perchloric acid, or mixtures or combinations thereof, or treatment with a base after oxidation or treatment with a base after chlorination.

[0028] Unlike unoxidized carbon black, oxidized carbon black has a significant oxygen content. The degree of oxidation of the oxidized carbon black used in the implementation of the present invention can vary. For example, oxidized carbon black may have an oxygen content of 0.5% by weight or more, for example, 1% by weight or more, or 2% by weight or more, based on the total weight of the oxidized carbon black material. Typically, the oxygen content does not exceed 20% by weight based on the total weight of the oxidized carbon black material. For example, oxidized carbon black may contain 0.5% to 20% by weight, or 1% to 15% by weight, or 2% to 10% by weight, or 2% to 5% by weight, based on the total weight of the oxidized carbon black material.

[0029] As described above, the carbon oxide black used in the present invention may contain carboxylic acid functional groups. For example, the carbon oxide black may contain at least 50 μmol of carboxylic acid groups per gram of carbon black, for example, in the range of 50 to 500 μmol or 100 to 300 μmol per gram of carbon black. The amount of carboxylic acid groups can be determined by titration as described in the experimental section below.

[0030] As described in the examples, the volatile content of the carbon black oxide measured at 950 °C can be at least 1% by weight, for example in the range of 1-15% by weight or 2-8% by weight.

[0031] The carbon black oxide used according to the present invention particularly has a BET surface area in the range of 10-300 m 2 / g, typically in the range of 50-300 m 2 / g, for example 75-250 m 2 / g, 90-200 m 2 / g, 100-175 m 2 / g or 125-150 m 2 / g. The BET surface area can be determined according to ASTM D6556-17.

[0032] The carbon black oxide used according to the present invention particularly has a specific surface area (STSA) in the range of 10-200 m 2 / g, for example 50-200 m 2 / g, 75-175 m 2 / g, 100-140 m 2 / g or 125-140 m 2 / g. The statistical thickness surface area (STSA) can be determined according to ASTM D6556-17.

[0033] The carbon black oxide used according to the present invention has an oil absorption amount (OAN) measured according to ASTM D2414-18, which can be 50-250 mL / 100 g, for example 75-225 mL / 100 g, 90-200 mL / 100 g, 100-175 mL / 100 g, or 110-160 mL / 100 g. The carbon black oxide according to the present invention can further have a compressed oil absorption amount (COAN) of 50-150 mL / 100 g, for example 75-125 mL / 100 g, 90-120 mL / 100 g, or 100-120 mL / 100 g. The COAN can be determined according to ASTM D3493-18.

[0034] The carbon black oxide according to the present invention is not limited to but may include furnace black oxide, lamp black oxide, gas black oxide, or a combination thereof. Preferably, the carbon black oxide includes furnace black oxide. The carbon black oxide according to the present invention may include, for example, carbon black grades commercially available from Orion Engineered Carbons, Inc. under trade names such as ECORAX®, CORAX®, or PRINTEX®, which have been subjected to the oxidation treatment described above.

[0035] As described above, carbon black oxide is treated with a sulfur-containing primary or secondary amine or a salt thereof to obtain functionalized carbon black. Thus, this treatment imparts a sulfur-containing moiety and / or functional groups derived from the treatment agent, such as amine groups, to the carbon black oxide, resulting in a chemical change of the carbon black oxide. Functionalization can be based on various types of interactions between carbon black oxide and sulfur-containing amines, such as adsorption or absorption of the amine on the surface or bulk of the carbon black, intermolecular bonding such as hydrogen bonding or salt formation, or the formation of covalent bonds such as amide bonds.

[0036] The chemical properties of the functional groups present on the surface of the particles of the functionalized carbon black according to the present invention, as understood herein, are not particularly limited and may include those described above with respect to carbon black oxide, and those that can be introduced by sulfur-containing amines, for example, by bonding the sulfur-containing amine to the carbon black oxide, or by the reaction of the functional groups of the sulfur-containing amine with the functional groups of the carbon black oxide. For example, the carboxylic acid groups of carbon black oxide can react at high temperatures with the amine groups of a sulfur-containing primary or secondary amine under the formation of an amide bond. Thus, a covalent amide bond can be formed between the oxygen-containing groups on the oxidized surface of the carbon black oxide and the amine functional groups of the sulfur-containing amine component. For example, the amine groups of the amine component can react with carboxylic acid groups, carboxylic acid bases, or anhydride groups present on the surface of the carbon black oxide particles. The degree of functionalization of the functionalized carbon black according to the present invention, i.e., the number of chemical functional groups per unit mass of carbon black, can be varied. Therefore, it is preferable that the residue of the sulfur-containing primary or secondary amine is bonded to the carbon black oxide by covalent bonds such as amide bonds in the functionalized carbon black.

[0037] As described above, the functionalized carbon black according to the present invention is obtained by treating an oxidized carbon black material with a sulfur-containing primary or secondary amine or a salt thereof. The terms “sulfur-containing primary or secondary amine or a salt thereof,” “sulfur-containing amine,” etc., can be used interchangeably throughout this specification unless otherwise specified. The sulfur-containing amine components that can be used according to the present invention may include any compound that contains both sulfur (in bonded form) and one or more primary or secondary amine groups. A primary amine group refers to a group with the general structure “-NH2,” and a secondary amine group refers to a group with the structure “-NHR,” where R is an organic substituent such as an alkyl group, an aryl group, or an arylalkyl group. Salts of sulfur-containing amines can also be used in the same manner. In other words, the primary and / or secondary amine groups can also exist in the corresponding protonated form as ammonium groups.

[0038] The sulfur-containing amines used in accordance with the present invention may include monomers or polymeric organic compounds and mixtures or combinations thereof. Typically, it is a monomeric sulfur-containing amine. Its molecular weight may be, for example, 500 g / mol or less, for example, 400 g / mol or less, 200 g / mol or less, or 175 g / mol or less. The sulfur-containing amine may, for example, contain at least one sulfide, oligosulfide, and / or polysulfide moiety. Furthermore, the sulfur-containing amine contains at least one amine group, for example, at least two or at least three, individually selected from primary amine groups and secondary amine groups. The primary and / or secondary amine groups may be blocked or not. Blocking can be achieved by any protecting group conventionally known in the art, for example, in the form of a carbamate. In addition to sulfur and amine functional groups, the sulfur-containing amine component may contain further chemical functional groups, such as oxygen-containing groups. However, it may not contain such additional functional groups.

[0039] Preferably, the sulfur-containing primary or secondary amine according to the present invention has the chemical formula R 1 -S x -Z-NR 2 R 3 The compound comprises, where Z is a divalent organic group containing 1 to 20 carbon atoms, x is an integer of at least 1, and R 1 , R 2 and R 3 Each of these is individually selected from hydrogen and a monovalent organic group containing 1 to 20 carbon atoms, such as an alkyl group, aryl group, or arylalkyl group. More preferably, Z is an alkylene group containing 1 to 8 carbon atoms. Furthermore, R 1 is C1-C 12 It can represent an alkyl group, where any one or more hydrogen atoms are in the chemical formula -NR 4 R 5 It may be substituted with a functional group such as an amine group, where R 4 and R 5Each of these is individually selected from a monovalent organic group containing 1 to 20 carbon atoms, such as a hydrogen atom and an alkyl group, an aryl group, or an arylalkyl group. The integer x is preferably an integer in the range of 2 to 20, for example, 2 to 6, and more preferably the integer x is equal to 2.

[0040] The preferred sulfur-containing primary or secondary amine according to the present invention is a sulfur-containing primary or secondary amine of the chemical formula S x (-Z-NR 2 R 3 ) Contains compound 2. Specific suitable sulfur-containing primary or secondary amines that can be used in the present invention are exemplified, but are not limited to, cystamine or its salts, for example, their respective hydrohalides. Suitable sulfur-containing primary or secondary amines for use in the present invention as described above are commercially available.

[0041] By utilizing the sulfur functional groups imparted to oxidized carbon black through treatment with sulfur-containing amine components, a strong chemical interaction between carbon black particles and vulcanizable rubber components can be established. For example, under appropriate reaction conditions, the sulfur portion can form covalent bonds, such as sulfur crosslinks, with reaction sites of vulcanizable rubber components, such as ethylenically unsaturated portions.

[0042] The functionalized carbon black or its precursor according to the present invention can be treated with one or more other chemical components before, during, or after treatment with a sulfur-containing amine component. This means that some or all of the particles of the functionalized carbon black can contain other or additional chemical functional groups on their surface. For example, the oxidized carbon black used to prepare the functionalized carbon black can be treated with a chemical that activates, i.e., increases the reactivity of, the oxygen-containing functional groups on the surface of the carbon black particles. Such additional treatment can increase the yield or reaction rate of subsequent chemical treatment steps, such as treatment with a sulfur-containing amine compound. More specifically, the carboxyl groups on the surface of the oxidized carbon black particles can be treated with any chemical component known to those skilled in the art so as to obtain an (activated) ester or anhydride. Suitable (activated) esters or anhydrides are known to be more reactive with amines than their corresponding carboxylic acids and can therefore increase the yield of amide functional groups when treated with a sulfur-containing amine component. One or more additional chemical components may also be applied together with the sulfur-containing amine component and may act as a catalyst or coupling agent by forming an activated complex or reactive intermediate, thereby resulting in, for example, an increase in the yield of the reaction product. Other chemical components may be applied to the functionalized carbon black or its precursor to delay or slow down chemical reactions such as the reaction with sulfur-containing amines.

[0043] It is also possible to introduce additional chemical reactivity of the functionalized carbon black to chemical groups other than amines by utilizing any one or more additional or other chemical functional groups introduced to the functionalized carbon black through treatment with one or more other chemical components. This means that the functionalized carbon black can interact more strongly with, for example, rubber materials or other components contained in each carbon black-containing compound, or be bonded by further chemical bonding.

[0044] The functionalized carbon black according to the present invention can be obtained, for example, by a method comprising (A) providing carbon oxide black, (B) contacting the carbon oxide black with a sulfur-containing primary or secondary amine or a salt thereof, and (C) subjecting the resulting mixture to conditions under which the carbon oxide black reacts with the sulfur-containing primary or secondary amine or a salt thereof. In the above method, the sulfur-containing primary or secondary amine or a salt thereof and / or carbon oxide black material may be as described above.

[0045] The relative amount of sulfur-containing amine components to oxidized carbon black can be varied. The sulfur-containing amine components can be applied in excess or in deficiency, based on the number of chemical functional groups available for the reaction of the applied carbon black. The sulfur-containing amine components can be added gradually or all at once.

[0046] Contact between carbon oxide black and sulfur-containing amine components can be carried out by any means known in the art for contacting the two components. Typically, this involves mixing the carbon oxide black and sulfur-containing amine components and can be carried out using any apparatus conventionally applied for this purpose. Preferably, when contacting carbon oxide black and sulfur-containing amine, at least macroscopically homogeneous mixtures are formed. If the sulfur-containing amine component is solid at the mixing temperature, however, for example, if only a relatively small amount of sulfur-containing amine component is provided, a solvent or processing aid such as oil can be added before or during contact with the carbon oxide black. The solvent can be selected to dissolve the sulfur-containing amine component. If the sulfur-containing amine component is liquid at the mixing temperature, the use of a solvent or processing aid can be omitted. During mixing in step (B), the temperature of the mixture remains below the level at which a reaction occurs between the carbon oxide black and sulfur-containing amine component, typically below 80°C or below 60°C. Mixing can be carried out, for example, at room temperature or slightly higher (e.g., up to 40°C). However, higher temperatures can be used, for example, as in-situ preparations further described below.

[0047] The mixture may, if necessary, include further auxiliary components in addition to the oxidized carbon black and sulfur-containing amine components. For example, the mixture may include substances that act as coupling agents or catalysts for coupling reactions and / or for removing protecting groups, if present. As further stated above, if additional chemical functional groups are provided for the functionalized carbon black, the corresponding reactants may be added before or after contact with the sulfur-containing amine components.

[0048] The reaction conditions in step (C) of the above method can be selected to allow the formation of an amide bond between the oxidized carbon black and the sulfur-containing amine component. Step (C) may, for example, include heating the mixture to a temperature of at least 100°C (e.g., in the range of 100°C to 160°C) for at least 1 minute (e.g., 2 to 10 minutes). Heating can be applied by any conventional means, such as by heating rods, heating plates, or by stirring at a high rotor speed and high shear force. Heating by stirring is particularly advantageous when the reaction is induced in situ in the presence of the vulcanizable rubber component.

[0049] As described above, the reaction between oxidized carbon black and sulfur-containing amine components can be carried out in situ, that is, in the presence of the vulcanizable rubber component, or the functionalized carbon black of the present invention can be formed separately and then compounded with the vulcanizable rubber component and a suitable vulcanizing agent to form the vulcanizable rubber composition according to the present invention. The above in-situ route is described in more detail below in the context of the preparation of the vulcanizable rubber composition according to the present invention.

[0050] Accordingly, the present invention also relates to a vulcanizable rubber composition comprising (i) a vulcanizable rubber component, (ii) carbon black oxide, and (iii) a sulfur-containing primary or secondary amine or a salt thereof. Thus, the functionalized carbon black of the present invention can be formed in situ from carbon black oxide and a sulfur-containing amine. Alternatively, the functionalized carbon black may be formed separately and then combined with the vulcanizable rubber component. In any case, the present invention also relates to a vulcanizable rubber composition comprising a vulcanizable rubber component (i) and a functionalized carbon black formed from carbon black oxide (ii) and a sulfur-containing primary or secondary amine or a salt thereof (iii).

[0051] The term "vulcanizable rubber composition" refers to a composition of rubber components that can be cured by vulcanization in the presence of a vulcanized product, and which optionally contains various further components conventionally used in the art of rubber compounding. The terms "curable" and "vulcanizable" are used interchangeably throughout this specification unless otherwise specified, and refer to a chemical reaction that links polymer chains together by means of a crosslinking agent or vulcanizing agent.

[0052] Suitable vulcanizable rubber components for use in vulcanizable rubber compositions include one or more rubbers or elastomers containing olefinic unsaturation, i.e., diene rubbers or elastomers. The terms “rubber” and “elastomer” can be used interchangeably throughout this specification unless otherwise specified. The rubber components may also include mixtures of rubber containing olefinic unsaturation with other unsaturated polymer materials, such as thermoplastic or thermosetting polymers. However, preferably, the rubber components include only one or more rubbers containing olefinic unsaturation. The terms “rubber containing olefinic unsaturation” and “diene rubber” are used interchangeably and are intended to include both natural rubber and synthetic rubber or mixtures thereof. Natural rubber can be used in its raw form and in various processed forms conventionally known in the art of rubber processing. Synthetic diene rubber may be any rubber containing at least one diene monomer that constitutes rubber, either alone or together with other monomers. Suitable exemplary diene rubber materials in the implementation of the present invention include, but are not limited to, natural rubber, emulsion-styrene-butadiene rubber, solution-styrene-butadiene rubber, polybutadiene, polyisoprene, ethylene-propylene-diene rubber (EPDM), butyl rubber and halogenated butyl rubber, acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, polychloroprene, and any combination thereof. The rubber composition according to the present invention may also contain one or more non-diene rubber materials. Suitable exemplary non-diene rubber materials in the implementation of the present invention include, but are not limited to, ethylene-propylene rubber (EPM), chlorinated polyethylene, chlorosulfonated polyethylene, acrylate rubber, ethylene-vinyl acetate rubber, ethylene-acrylic rubber, epichlorohydrin rubber, silicone rubber, fluorosilicone rubber, fluorocarbon rubber, and any combination thereof. Suitable rubbers also include functionalized rubbers and rubbers bonded to silicon or tin.For example, rubber can be functionalized with functional groups such as amines, alkoxys, silyls, thiols, thioesters, thioethers, sulfanyls, mercaptos, sulfides, or combinations thereof. One or more functional groups may be primary, secondary, or tertiary, and may be located at one or both chain ends (e.g., α,ω-functionalization), suspended from the polymer backbone, and / or provided within the polymer backbone. The rubber according to the present invention can also be partially crosslinked. Thus, before use in a vulcanizable rubber composition, a portion of the polymer chain of the rubber material can be crosslinked by means of a coupling agent or without a coupling agent. The polymer material can further be supplied in any form, but typically as bales or chips.

[0053] Preferably, the rubber component includes a mixture of natural diene rubber and synthetic diene rubber. A non-limiting specific rubber material that can be used in the implementation of the present invention is, for example, Sprintan SLR4630, which is commercially available from Trinseo Germany.

[0054] The vulcanizable rubber composition may contain oxidized carbon black or functionalized carbon black derived therefrom in an amount of 10 to 100 phr, for example, 40 to 80 phr. The term "phr" as used herein refers to parts by weight of each listed individual material per 100 parts by weight of rubber or elastomer. The vulcanizable rubber composition according to the present invention may further contain a sulfur-containing primary or secondary amine or a salt thereof in an amount of 0.1 to 10 phr, for example, 0.2 to 5 phr or 0.3 to 3 phr, preferably 0.3 to 2 phr, for example, 0.5 to 1.5 phr. Thereafter, the sulfur-containing primary or secondary amine can be used in the form of a salt, such as an ammonium or hydrohalide salt.

[0055] The vulcanizable rubber composition according to the present invention may further contain, if necessary, at least one vulcanizing agent capable of inducing the curing of the rubber. Possible vulcanizing agents include any vulcanizing agents known in the art, such as sulfur and sulfur donors. Suitable sulfur donors for carrying out the present invention include, for example, dithioalkanes, dicaprolactam sulfides, polysulfide polymers, sulfur olefin adducts, thiram, and sulfonamides having at least two sulfur atoms in the sulfur crosslinks. Preferably, elemental sulfur can be used. The vulcanizing agent may be present in the vulcanizable rubber composition in an amount ranging from 0.5 to 8 phr, for example, from 1 to 4 phr.

[0056] Furthermore, the vulcanizable rubber composition preferably contains a base such as a basic metal oxide and / or a metal hydroxide. Suitable basic metal oxides can be exemplified by oxides of alkali metals or alkaline earth metals such as Na2O, K2O, CaO, or MgO. Suitable metal hydroxides can be exemplified by hydroxides of alkali metals or alkaline earth metals such as NaOH, Mg(OH)2, or Ca(OH)2. These components may be included to assist in the in-situ functionalization of carbon oxide black with sulfur-containing amines, as they can neutralize acidic byproducts, adsorb water, and / or act as curing activators. The basic metal oxide and metal hydroxide may each be included independently in amounts ranging from 0.1 phr to 5 phr, for example, from 1 phr to 3 phr.

[0057] The vulcanizable rubber composition may further contain one or more additional fillers, such as other carbon blacks, silica, organic silica, carbon nanotubes, carbon fibers, graphite, and metal fibers. Useful carbon blacks in this regard can be exemplified by ASTM-grade carbon blacks selected from the 100er-900er series, as classified according to ASTM D1765.

[0058] The vulcanizable rubber composition according to the present invention may further contain other commonly known additives. Such additives include, for example, curing aids (primary and secondary vulcanization accelerators, activators, pre-vulcanization inhibitors, etc.), processing additives (oils, resins in the form of tackifying resins, and plasticizers, etc.), softeners, pigments, waxes, peptizing agents, and anti-aging agents (antioxidants and ozone degradation inhibitors, etc.). Useful primary and secondary vulcanization accelerators include, for example, guanidine, dicarbamates, dithiocarbamates, thiuram, thioureas, 2-mercaptobenzothiazole, benzothiazole sulfonamides, aldehyde amines, amines, disulfides, thiazoles, xanthetes, and sulfenamides. Specific examples include N-tert-butyl-2-benzothiadylsulfenamide, marketed by Rhenogran Additives under the trade name Rhenogran TBBS-80, and diphenylguanidine, marketed by Rhenogran Additives as Rhenogran DPG-80. Suitable activators include combinations of zinc oxide and fatty acids such as stearic acid, lauric acid, palmitic acid, oleic acid, or naphthenic acid. Primary accelerators can be present in the composition in a total amount ranging from 0.05 to 4 phr. Secondary accelerators are typically used in smaller amounts than primary accelerators and can be present in the composition in an amount ranging from 0.05 to 3 phr.

[0059] As can be understood, the vulcanizable rubber compositions according to the present invention can be used in a variety of technical applications requiring rubber-based materials with reduced loss hysteresis, enhanced filler-rubber bonding, and / or increased abrasion resistance. Accordingly, the present invention also relates to articles manufactured from or containing the above-mentioned vulcanizable rubber compositions. Non-limiting examples of such articles include tires, tire components such as tire treads or sidewalls, cable sheaths, tubes, drive belts, conveyor belts, roll covers, shoe soles, sealing members, profiles, or damping elements. Due to the exceptional combination of low hysteresis and high abrasion resistance, the vulcanizable rubber compositions according to the present invention are of particular interest in manufacturing abrasion-resistant and fuel-efficient tires or tire components with reduced rolling resistance and heat buildup. Such tires include, but are not limited to, truck tires, passenger car tires, off-road tires, aircraft tires, agricultural tires, and earthmoving tires.

[0060] The vulcanizable rubber composition according to the present invention can be obtained by a method in which the functionalized carbon black is produced ex-situ or in-situ, that is, in the absence or presence of the vulcanizable rubber component, respectively. Accordingly, the present invention also relates to a method for preparing a vulcanizable rubber composition, comprising contacting carbon oxide black with a sulfur-containing primary or secondary amine or a salt thereof, and providing the resulting mixture under conditions in which the carbon oxide black reacts with the sulfur-containing primary or secondary amine or a salt thereof to form functionalized carbon black, wherein the vulcanizable rubber component is mixed with the carbon oxide black and the sulfur-containing amine component or functionalized carbon black derived therefrom before, during and / or after providing the mixture under conditions in which the carbon oxide black reacts with the sulfur-containing amine component.

[0061] In a preferred embodiment of the present invention, the functionalized carbon black is formed in the presence of a vulcanizable rubber composition. Therefore, the vulcanizable rubber component is preferably mixed with the carbon oxide and sulfur-containing amine compound before or during the application of the mixture to conditions under which the carbon oxide reacts with the sulfur-containing amine compound.

[0062] This method may further include adding basic metal oxides and / or metal hydroxides, such as those mentioned above, before or after mixing the oxidized carbon black and sulfur-containing amine compounds with the rubber components. Preferably, the metal oxides and metal hydroxides are added to the carbon black and sulfur-containing amine compounds together with the rubber components.

[0063] The mixing can be carried out so that the oxidized carbon black material, sulfur-containing amine component, vulcanizable rubber component, and metal oxides and / or metal hydroxides, if present, as well as any further selective components, if used, are at least partially mixed together. Preferably, all components are mixed together completely so that a mixture that is at least macroscopically homogeneous is obtained.

[0064] This method may include a step of plasticizing the vulcanizable rubber component, for example by a stirring means, before mixing the vulcanizable rubber component with carbon black oxide and an amine compound. For this purpose, the vulcanizable rubber component may be provided in a suitable apparatus such as an internal mixer and stirred for 2 minutes or less, for example, 1 minute or less, for example, 45 seconds. Subsequently, carbon black oxide, a sulfur-containing amine component and potentially further optional components may be added to the plasticized vulcanizable rubber component and mixed together as disclosed above.

[0065] Mixing can be carried out using techniques and equipment conventionally known in the field of rubber processing. Mixing can be achieved, for example, by mixers, agitators, mills, kneaders, ultrasonic machines, melters, shaker mixers, rotor-stator dispersion assemblies, or high-pressure homogenizers, or combinations thereof. Preferably, mixers having meshing or tangential rotor shapes are used.

[0066] Mixing may involve heating the components of the mixture to a temperature higher than room temperature if necessary. However, preferably, mixing is carried out without adding any extra heat to the mixture beyond the heat that can be generated by the stirring process itself. The temperature generated from the stirring method can be used to provide the mixture with conditions under which the carbon black oxide reacts with the sulfur-containing amine component to form functionalized carbon black. The conditions during mixing can be selected, for example, to form amide bonds between the carboxyl groups of the carbon black oxide and the amine groups of the sulfur-containing amine component. Thereafter, the temperature of the mixture is maintained typically below 200°C, preferably around 150°C, by gradually or stepwise changing the rotor speed as needed.

[0067] The mixing may be carried out such that the carbon oxide black reacts with the sulfur-containing amine component under the formation of functionalized carbon black during homogenization with the rubber component and any further components, i.e., homogenization and reaction occur in a single mixing step. However, in a preferred embodiment of the present invention, the carbon oxide black, sulfur-containing amine component, rubber component and any further components are at least macroscopically homogenized in the first mixing step, and the mixture thus obtained is cooled to room temperature before the components of the mixture are subjected to the second mixing step. Depending on the specific mixing conditions in the two mixing steps, the reaction between the carbon oxide black and the sulfur-containing amine component may occur in the first and / or second mixing steps.

[0068] The duration of the first mixing step can be varied. However, the mixing time can be important depending on the chemical properties of the components. For example, some components may be sticky, in which case extensive mixing on an open mill should be avoided. Typically, the mixing time in the first step is less than 10 minutes, e.g., less than 5 minutes, less than 2 minutes, e.g., 90 seconds. The release temperature of the composition in the first mixing step is typically maintained below 190°C, preferably between 130°C and 150°C.

[0069] After the first mixing step, the resulting mixture can be immediately subjected to the second mixing step or stored between the two steps. The mixture can be left to stand for, for example, several minutes to several months, for example, at least 60 minutes or at least 12 hours. Before the second mixing step, the mixture can be transferred to another mixing chamber and / or another location, for example, to the customer.

[0070] In the second mixing step, the mixture is typically stirred using an internal mixer having, for example, a meshing rotor shape. The rotor speed can be in the range of 10 to 150 rpm, preferably 80 to 120 rpm, so that the mixture can be heated without the need to apply an additional heat source. The duration of the second mixing step can range from a few seconds to several hours, for example from 1 or 5 minutes to 2 hours or 30 minutes. The rotor speed can be adjusted during this time to maintain the temperature of the mixture at a specific level, for example in the range of 120°C to 200°C or 140°C to 180°C, for example, about 150°C.

[0071] After the first mixing step, or after the second mixing step, if present, the method for preparing the vulcanizable rubber composition further includes the step of adding to the mixture, preferably sulfur or a sulfur donor or other vulcanizing agent, and optionally one or more activators, one or more accelerators, and further components conventionally used in the art of rubber compounding as described above. Subsequently, it is preferable to mechanically stir the composition to achieve at least partial, or preferably complete, mixing of the composition. The mixing is carried out at a temperature typically between 10°C and 140°C, more typically between 80°C and 120°C, under constant stirring for less than 5 minutes, for example, less than 3 minutes. The conditions, in particular the rotor speed, can be selected so that the temperature of the mixture containing the curing agent is below 110°C.

[0072] The mixture thus obtained can be cured, or vulcanized. This method allows for the crosslinking of polymer chains in the rubber material, as well as the linkage of functionalized carbon black particles to the rubber matrix, via sulfur functional groups introduced to the surface of the carbon black particles by sulfur-containing amines. This linkage is thought to increase the carbon black-elastomer interaction.

[0073] Curing can be carried out using conventional curing methods and conditions known in the field of rubber processing. For example, the vulcanizable rubber composition according to the present invention can be cured by applying thermosetting conditions to the mixture, for example, at a temperature of 120-200°C for 5 minutes to 3 hours. Curing can also be carried out, for example, in a curing press, at a temperature of 160°C for 60 minutes and a pressure of 120-150 bar.

[0074] The present invention will be further illustrated by the following embodiments. It should be understood that these embodiments are included for illustrative purposes and should not be construed as limiting the invention. In particular, the scope of protection sought should not be limited by the specific embodiments disclosed below, but rather by the entire scope of the appended claims, which encompass any equivalent thereof. [Examples]

[0075] All parts and proportions referred to herein are by weight unless otherwise indicated. Applicable carbon black materials

[0076] As carbon oxide black (CB), we used EB287, which has the properties summarized in Table 1 and is commercially available from Orion Engineered Carbons.

[0077] For reference, we used Printex® 60, a non-oxidizing carbon black grade commercially available from Orion Engineered Carbons. Its properties are similarly included in Table 1. [Table 1] Applied method for characterizing carbon black

[0078] The BET surface area was measured by nitrogen adsorption according to ASTM D6556-17.

[0079] The statistical thickness surface area (STSA) was determined according to ASTM D6556-17.

[0080] Oil absorption capacity (OAN) was measured according to ASTM D2414-18.

[0081] The oil absorption capacity (COAN) of the compressed sample was measured according to ASTM D3493-18.

[0082] pH was measured according to D1512-15b, Test Method B-Sonic Slurry.

[0083] The volatile content at 950°C was measured using a thermogravimetric analyzer (TGA-701) from LECO Instruments, according to the following protocol. The sample dish was dried at 650°C for 30 minutes. The carbon black material was stored in a desiccator with a desiccant before measurement. The dried sample dish was loaded into the instrument, its weight was measured, and it was filled with 0.5g to 10g of carbon black material. The oven of the TGA instrument with the sample-filled dish loaded was then gradually heated to 105°C under automatic software control, drying the sample until a certain mass was achieved. Subsequently, the dish was closed with a lid, the oven was purged with nitrogen (99.9 vol% grade), and heated to 950°C. The oven temperature was maintained at 950°C for 7 minutes. The volatile content at 950°C was calculated using the following formula.

number

[0084] The number of carboxylic acid groups per unit mass of carbon black was determined according to the following protocol. The carbon black was dried overnight in a box-type dryer set at a temperature of 125°C. The hot carbon black material was removed from the dryer and cooled in a desiccator containing a desiccant. Three thoroughly washed and dried Erlenmeyer flasks were used to measure the amount of carbon black. CBEach of the carbon black material (1.5 ± 0.1 g) was weighed, and 25 ml of 0.05 Molar sodium hydroxide aqueous solution (Titrisol grade diluted with bi-distilled water) was added to each. The air in the flask was replaced with nitrogen gas, the flask was sealed with a plug, and further secured by taping with Parafilm. The flask was placed in a shaker at 240 rpm overnight. The resulting suspension was then pressure filtered using nitrogen gas at a pressure of 5 bar. 10 mL of each filtrate was transferred to a beaker. 10 mL of 0.025 Molar sulfuric acid (Titrisol grade diluted with bi-distilled water) was added to each beaker, and carbonates were removed by boiling briefly. Subsequently, the samples were titrated to pH 6.5 using 0.05 Molar sodium hydroxide solution (Titrisol grade diluted with bi-distilled water) and returned to the original sample. Required amount of sodium hydroxide solution V NaOH The amount was measured in mL with a precision of three decimal places after the comma. Two blanks were measured and the required amount of sodium hydroxide solution was averaged (V blank). , (Average). The concentration of carboxyl groups in μmol / g was calculated for all three samples using the following formula, and the obtained values ​​were averaged.

number

[0085] Using the aforementioned carbon oxide black and reference carbon black together with different amounts of cystamine as a sulfur-containing amine, the rubber compositions of the formulations shown in Table 2 were prepared according to the following procedure.

[0086] The preparation was carried out using a three-step mixing procedure. Each mixing step was performed in an internal mixer with a meshing rotor shape (GK1.5E). Subsequently, the mixture was cooled and further mixed in an open mill.

[0087] First, the rubber component was added to the mixing chamber of the internal mixer and plasticized for 45 seconds. Then, carbon black filler, Ca(OH)2, MgO, and cystamin were added. *2HCl was added and mixed for 90 seconds. The ram was lifted, washed, and then mixed for a further 135 seconds. During this step, care was taken to ensure that the maximum temperature did not exceed 160°C.

[0088] After storage for at least 12 hours, the mixture was heated to 150°C in the internal mixer by applying the maximum rotor speed (104 rpm) in the second mixing step. The temperature was maintained for approximately 2.5 minutes by adjusting the rotor speed.

[0089] Next, ZnO, stearic acid, sulfur, TBBS-80, and DPG-80 were added to this mixture and stirred for 2 minutes to obtain a vulcanizable rubber composition. During this step, care was taken to ensure that the maximum temperature did not exceed 110°C. [Table 2] Curing of vulcanizable rubber composition

[0090] The vulcanizable rubber composition was cured in a curing press at 160°C for 60 minutes. The applied pressure was 120-150 bar. Characterization of cured rubber compositions

[0091] Mooney viscosity (ML(1+4)100℃) was measured according to ISO289-1:2015.

[0092] Hardness was measured according to DIN 53 505.

[0093] Tensile strength, elongation at break, and modulus of elasticity 200 were measured according to DIN 53 504.

[0094] Ball rebound was measured according to the test methods based on ASTM 3574 and DIN ISO 8307, as follows: A cylindrical test sample with a diameter of 35 mm and a height of 19 mm was heated to 60 ± 0.2 °C. The circular regions of the test sample were ensured to be smooth and parallel to each other. A 19 mm diameter steel ball was dropped from a height of 500 mm through a drop tube into one of the circular regions of the test sample. The height corresponds to the distance between the lowest point of the steel ball and the point of impact on the test sample. The time interval between the first and second impacts of the steel ball on the test sample was measured by a light barrier located near the point of impact on the test sample. The time resolution of the light barrier was 10⁻¹⁰ -4 The value was s. The time interval measured in 5 experiments per test sample was averaged and applied to calculate the rebound height. Then, the rebound height was again used to calculate the ball rebound corresponding to the percentage ratio of the rebound height to the drop height.

[0095] DIN wear was tested according to DIN ISO 4649:2014-03.

[0096] Heat accumulation was tested according to DIN 53 533, applying a pre-tension of 1 MPa and a stroke of 4.45 mm. The chamber temperature was 55°C.

[0097] Loss coefficient tanδ and complex modulus E * The measurement was performed in accordance with DIN 53 513, at 60°C and a frequency of 16Hz, on a cylindrical test specimen (height 10mm, diameter 10mm), in strain control mode (1±0.5mm).

[0098] The bonded rubber was measured according to the following procedure. Approximately 0.2 g of rubber sample was cut into small pieces, weighed using an analytical balance, and placed in a wire basket (320 mesh, stainless steel, 22 mm diameter, 40 mm height) filled with glass wool, ensuring that the sample did not come into contact with the wire basket. The sample-containing basket was placed in a 100 mL flask with a screw cap, and 50-60 mL of toluene (analytical grade) was added to obtain a minimum packing level of 20 mm above the bottom of the flask. The flask was left at a temperature of 23 ± 2 °C for 7 days, during which time the flask was swirled every morning and evening. The toluene was replaced after 1-3 days. After 7 days, the basket containing the bonded rubber gel was removed from the flask and allowed to release the solvent overnight in a fume hood. Subsequently, the sample was dried overnight in a box-type dryer until the mass was constant. After cooling to room temperature in a desiccator, the sample was weighed (m(dried gel)). The weight percentage of the bonded rubber relative to the mass of the original sample was calculated using the following formula.

number

[0099] The results obtained are summarized in Table 3. [Table 3]

[0100] The results in Table 3 demonstrate that using oxidized carbon black in the rubber composition yields rubber articles with significantly improved hysteresis properties compared to the corresponding untreated reference carbon black, as evidenced by a reduced loss coefficient tanδ, reduced heat accumulation, increased ball rebound, and / or increased binding rubber (see comparison between Example 3 and Example 1). This effect can be further enhanced compared to Example 3 by treating the oxidized carbon black with a sulfur-containing amine, as demonstrated by Examples 5-9. As shown in Table 3, the use of functionalized sulfur-containing amines further improves indicators for durability and strengthening. This is reflected in the reduced amount of worn material in the DIN abrasion test. Furthermore, the combination of oxidized carbon black and sulfur-containing amines improves both the static and dynamic stiffness of the resulting rubber compound, which is reflected in increased modulus of elasticity of 200 and E, respectively. * These effects are reflected in the values. These effects are not observed, or are much less pronounced, when the rubber composition contains untreated reference carbon black (see Example 2). Furthermore, in the preparation of the rubber composition, the addition of MgO and Ca(OH)2 without sulfur-containing amine components results in a slight decrease in modulus and an increase in tensile strength, without affecting hysteresis-related properties (see comparison between Example 4 and Example 3). This indicates that the presence of both sulfur-containing amines and the oxidized carbon black that reacts with them is important for achieving the aforementioned combination of beneficial properties. Particularly favorable properties are obtained when relatively small amounts of functionalizing agents are used with respect to the amount of carbon black (see comparison between Example 4 and Example 5).

Claims

1. 1. A functionalized carbon black obtained by treating an oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof, The sulfur-containing primary or secondary amine is represented by the formula S x (-Z-NR 2 R 3 ) 2 wherein Z is an alkylene group containing 1 to 8 carbon atoms, x is an integer ranging from 2 to 6, and R 2 and R 3 are each individually selected from hydrogen and monovalent organic radicals containing from 1 to 20 carbon atoms and selected from alkyl, aryl, and arylalkyl groups.

2. 2. The functionalized carbon black of claim 1 , wherein the residue of a sulfur-containing primary or secondary amine is covalently attached to the oxidized carbon black.

3. 3. The functionalized carbon black of claim 1 or 2, wherein the sulfur-containing primary or secondary amine is a monomeric organic compound and / or has a molecular weight of less than 500 g / mol.

4. 4. The functionalized carbon black of claim 1, wherein the sulfur-containing primary or secondary amine or salt thereof comprises cystamine or a salt thereof.

5. The functionalized carbon black of any one of claims 1 to 4, wherein the oxidized carbon black comprises carboxylic acid groups in an amount of at least 50 μmol / g.

6. A method for making a functionalized carbon black comprising: (A) providing an oxidized carbon black; (B) contacting the oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof, wherein the sulfur-containing primary or secondary amine has the formula S x (-Z-NR 2 R 3 ) 2 wherein Z is an alkylene group containing 1 to 8 carbon atoms, x is an integer ranging from 2 to 6, and R 2 and R 3 are each individually selected from hydrogen and a monovalent organic radical containing from 1 to 20 carbon atoms and selected from alkyl, aryl, and arylalkyl groups; (C) subjecting the resulting mixture to conditions under which the oxidized carbon black reacts with a sulfur-containing primary or secondary amine or salt thereof.

7. 7. The method of claim 6, wherein step (C) comprises heating the mixture to a temperature of at least 100° C. for at least 1 minute.

8. (i) a vulcanizable rubber component; (ii) oxidized carbon black, and (iii) a sulfur-containing primary or secondary amine or a salt thereof; Contains, or A vulcanizable rubber composition comprising a vulcanizable rubber component (i) and a functionalized carbon black formed from an oxidized carbon black (ii) and a sulfur-containing primary or secondary amine or salt thereof (iii): wherein the sulfur-containing primary or secondary amine is of the formula S x (-Z-NR 2 R 3 ) 2 wherein Z is an alkylene group containing 1 to 8 carbon atoms, x is an integer ranging from 2 to 6, and R 2 and R 3 are each individually selected from hydrogen and monovalent organic radicals containing from 1 to 20 carbon atoms and selected from alkyl, aryl, and arylalkyl groups.

9. 9. The vulcanizable rubber composition of claim 8, wherein the vulcanizable rubber component comprises natural rubber, emulsion styrene-butadiene rubber, solution styrene-butadiene rubber, polybutadiene, polyisoprene, ethylene-propylene-diene rubber EPDM, ethylene-propylene rubber EPM, halogenated butyl rubber, butyl rubber, chlorinated polyethylene, chlorosulfonated polyethylene, acrylonitrile-butadiene rubber, hydrogenated acrylonitrile-butadiene rubber, polychloroprene, acrylate rubber, ethylene-vinyl acetate rubber, ethylene-acrylic rubber, epichlorohydrin rubber, silicone rubber, fluorosilicone rubber, fluorocarbon rubber, or combinations thereof.

10. 10. The vulcanizable rubber composition of claim 8 or 9, wherein the oxidized carbon black or functionalized carbon black derived therefrom is present in an amount of 10 to 100 phr, and / or the sulfur-containing primary or secondary amine or salt thereof is used in an amount of 0.1 to 10 phr.

11. The vulcanizable rubber composition according to any one of claims 8 to 10, wherein the sulfur-containing primary or secondary amine is used in the form of the corresponding ammonium salt and / or the composition further comprises a base.

12. contacting the oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof, wherein the sulfur-containing primary or secondary amine has the formula S x (-Z-NR 2 R 3 ) 2 wherein Z is an alkylene group containing 1 to 8 carbon atoms, x is an integer ranging from 2 to 6, and R 2 and R 3 are each individually selected from hydrogen and a monovalent organic radical containing from 1 to 20 carbon atoms and selected from alkyl, aryl, and arylalkyl groups; a process for preparing a vulcanizable rubber composition comprising subjecting the resulting mixture to conditions under which the oxidized carbon black reacts with a sulfur-containing primary or secondary amine or salt thereof to form a functionalized carbon black; Here, a vulcanizable rubber component is mixed with the oxidized carbon black and the sulfur-containing amine component, or a functionalized carbon black derived therefrom, before, during and / or after subjecting the mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing amine component.

13. An article prepared from the vulcanizable rubber composition of any one of claims 8 to 11.

14. 14. The article of claim 13 which is a tire, a tire component, a cable sheath, a tube, a drive belt, a conveyor belt, a roll cover, a shoe sole, a seal, a profile or a braking element.

15. Use of a sulfur-containing primary or secondary amine or a salt thereof for surface modification of oxidized carbon black and / or as a coupling agent in a carbon black-containing vulcanizable rubber composition: wherein the sulfur-containing primary or secondary amine is of the formula S x (-Z-NR 2 R 3 ) 2 wherein Z is an alkylene group containing 1 to 8 carbon atoms, x is an integer ranging from 2 to 6, and R 2 and R 3 are each individually selected from hydrogen and monovalent organic radicals containing from 1 to 20 carbon atoms and selected from alkyl, aryl, and arylalkyl groups.

16. Use of a sulfur-containing primary or secondary amine or a salt thereof in a carbon black-containing vulcanizable rubber composition to reduce the loss factor tan δ at 60° C., and / or to reduce heat build-up, and / or to increase bound rubber, and / or to improve abrasion resistance, as compared to a corresponding carbon black-containing vulcanizable rubber composition that does not contain the sulfur-containing primary or secondary amine or a functionalized carbon black derived therefrom: wherein the sulfur-containing primary or secondary amine is of the formula S x (-Z-NR 2 R 3 ) 2 wherein Z is an alkylene group containing 1 to 8 carbon atoms, x is an integer ranging from 2 to 6, and R 2 and R 3 are each individually selected from hydrogen and monovalent organic radicals containing from 1 to 20 carbon atoms and selected from alkyl, aryl, and arylalkyl groups.