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

Abstract

To provide a functionalized carbon black, a production process, a vulcanizable rubber composition, and an article, the functionalized carbon black being particularly useful for obtaining rubber compounds with low hysteresis and enhanced abrasion resistance, for example for the manufacture of energy-saving tires.SOLUTION: Provided is a functionalized carbon black obtained by treating an oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof. Also provided is a process for preparing such functionalized carbon black. Further provided is a vulcanizable rubber composition comprising (i) a vulcanizable rubber component, and (ii) an 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. Also provided is an article made from the vulcanizable rubber composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to functionalized carbon black, related vulcanizable rubber compositions and articles made therefrom, and their respective preparation processes. More specifically, the present disclosure relates to functionalized carbon black obtainable by treating oxidized carbon black with a sulfur-containing amine. The functionalized carbon black is particularly useful for obtaining rubber products with reduced hysteresis and good abrasion resistance, for example in tire applications. [Background technology]

[0002] Carbon black is included in many rubber-based compounds to modify their color, mechanical, electrical, and / or processing properties. Carbon black, for example, is commonly added to rubber compositions used to manufacture tires or their components to impart electrical dissipative properties to the insulating matrix. At the same time, carbon black additives affect mechanical and elastic properties such as stiffness, abrasion resistance, and hysteresis, which greatly affect the performance of the resulting tire, e.g., its rolling resistance and durability. Here, carbon black tends to form networks in the matrix through strong filler-filler interactions, which are the primary source of heat accumulation in the rubber component. Due to regulatory requirements and increasing environmental pressures, there is an increasing demand for energy-efficient tires with low rolling resistance. At the same time, other performance parameters, such as grip, traction, and durability, must not be adversely affected. This often represents a competing requirement.

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

[0004] Alternatively, chemical modifications of the rubber material and / or the carbon black filler have been developed to enhance the filler-rubber interaction.

[0005] For example, U.S. Patent No. 5,248,722 describes an elastomer composition that utilizes an end-functionalized polymer in combination with an acid-functional oxidized carbon black to reduce rolling resistance in tire tread applications. However, the end-functionalized polymer is not readily available and must be prepared in a dedicated process 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 WO 2011 / 028337, the use of surface-treated carbon black in combination with functionalized SBR polymers functionalized with oxygen-containing groups such as carboxylic acid or hydroxyl groups along the chain enhances carbon black-elastomer interactions, resulting in reduced hysteresis and wet traction benefits compared to the use of conventional carbon black-containing compounds. However, this approach also requires the use of specialized polymeric materials.

[0007] EP 3339364 proposes using oxidized carbon black in combination with a polymeric amine having primary amine functionality, such as polyethyleneimine, to obtain a rubber compound with improved hysteresis for tires with low rolling resistance, although the abrasion resistance of the resulting rubber compound is somewhat impaired.

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

[0009] It is therefore an object of the present invention to provide a functionalized carbon black capable of imparting the above-mentioned 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 utilizing readily available ingredients and processing techniques. The present invention aims to provide a vulcanizable rubber composition that provides both improved hysteresis and increased abrasion resistance, making it suitable for tire manufacture. Summary of the Invention

[0010] Surprisingly, it has now been found that the above objectives can be achieved by means of functionalized carbon black obtained by treating oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof.

[0011] The functionalized carbon black of the present invention can be obtained by a method including: (A) providing oxidized carbon black; (B) contacting the oxidized carbon black with a sulfur-containing primary or secondary amine or salt thereof; (C) subjecting the resulting mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing primary or secondary amine or 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, for example in situ during the preparation of the vulcanizable rubber composition or separately, to obtain such a functionalized carbon black material.

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

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

[0015] Additionally, the present invention generally relates to the use of sulfur-containing primary or secondary amines or salts thereof for the surface modification of oxidized carbon black and / or as coupling agents in vulcanizable rubber compositions containing carbon black.

[0016] The functionalized carbon blacks according to the invention can be obtained from commercially available components in an efficient manner at low cost using common processing techniques. They have been found to impart a favorable combination of properties to the rubber compounds to which they are added or into which they are formed, in particular resulting in significantly reduced hysteresis and improved wear resistance, making them particularly interesting for the manufacture of energy-saving tires.

[0017] Without intending to be bound by any theory, it is believed that the use of sulfur-containing primary or secondary amines allows their bifunctionality, i.e., sulfur functionality and amine functionality having one or more NH moieties, to form strong interactions, for example, covalent bonds and / or hydrogen bonds, with oxidized carbon black, which generally has polar oxygen-containing groups on its surface, and with vulcanizable rubber components, which generally contain vulcanizable moieties such as ethylenically unsaturated groups that have an affinity for sulfur-containing moieties. Thus, effective coupling of the functionalized carbon black to the rubber component can be achieved, effectively reducing filler-filler interactions and resulting in rubber compounds with low hysteresis and high durability and mechanical stiffness.

[0018] Accordingly, the present invention also relates to the 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 (e.g., measured at 60°C), and / or reduce heat buildup, and / or increase bound rubber content, and / or improve abrasion resistance, compared to a corresponding carbon black-containing vulcanizable rubber composition that does not contain the sulfur-containing primary or secondary amine or functionalized carbon black derived therefrom.

[0019] These and other optional features and advantages of the present invention are described in more detail in the following description. DETAILED DESCRIPTION OF THE INVENTION

[0020] As used herein, the term "comprising" is understood to be open-ended and not to exclude the presence of additional, undescribed or unlisted elements, materials, components, or method steps. The terms "including," "containing," and similar terms are understood to be synonymous with "comprising." As used herein, the term "consisting of" is understood to exclude the presence of any unspecified elements, components, or method steps.

[0021] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0022] Unless otherwise noted, the numerical parameters and ranges set forth in the following specification and appended claims are approximations. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. Any numerical values, however, contain errors necessarily resulting from the standard deviation in their respective measurements.

[0023] It is also to be understood that any numerical range recited herein is intended to encompass all subranges therein. For example, a range of "1 to 10" is intended to encompass any and all subranges between and including the recited minimum value of 1 and the recited maximum value of 10, i.e., all subranges beginning 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 noted above, the present invention relates to functionalized carbon black obtained by treating oxidized carbon black with a sulfur-containing primary or secondary amine or salt thereof.

[0025] "Carbon black" as referred to herein is a material consisting essentially of carbon, for example, 90% by weight or more or 95% by weight or more, based on its total weight, produced by controlled partial pyrolysis of one or more hydrocarbon precursors. Various industrial methods are known for producing carbon black materials, such as the furnace process, the gas black process, the acetylene black process, the thermal black process, or the lamp black process. The production of carbon black is well known in the art and is reviewed, 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 practice of the present invention may also comprise a mixture 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 an oxidation treatment and therefore contains oxygen-containing functional groups. The oxygen-containing functional groups can be present, in particular, on the surface of the carbon black particles. Examples of oxygen-containing functional groups include, but are not limited to, quinone, carboxyl, phenol, lactol, lactone, anhydride, and ketone groups. As used herein, carboxylic acid or anhydride groups on the surface of carbon black particles are considered particularly favorable for forming strong interactions with sulfur-containing amine components due to the ability of these polar groups to form relatively strong bonds, for example, by salt formation, hydrogen bond formation, or reactions that form covalent amide bonds, for example.

[0027] Oxidized carbon black suitable for the practice of the present invention can be prepared by any method conventionally known in the art of carbon black oxidation, such as those disclosed in U.S. Patent Nos. 6,120,594 and 6,471,933. Suitable methods include, for example, oxidation of the carbon black material with peroxides such as hydrogen peroxide, persulfates such as sodium persulfate and potassium persulfate, hypohalites such as sodium hypochlorite, ozone gas or oxygen gas, permanganates, transition metal-containing oxidizing agents such as osmium tetroxide, chromium oxide, ammonium cerium nitrate, or oxidizing acids such as nitric acid and perchloric acid, and mixtures or combinations thereof, or oxidation followed by treatment with a base or chlorination followed by treatment with a base.

[0028] Oxidized carbon black, unlike non-oxidized carbon black, has a significant oxygen content. The degree of oxidation of the oxidized carbon black used in the practice of the present invention can vary. For example, the oxidized carbon black can have an oxygen content of 0.5% by weight or more, e.g., 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, the oxidized carbon black can 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 of oxygen, based on the total weight of the oxidized carbon black material.

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

[0030] The volatile content of the oxidized carbon black, measured at 950° C. as described in the Examples, can be at least 1 wt %, for example, in the range of 1 to 15 wt %, or 2 to 8 wt %.

[0031] The oxidized carbon black used according to the invention is in particular of a carbon black having a viscosity of 10 to 300 m 2 / g range, typically 50-300m 2 / g range, e.g., 75-250m 2 / g, 90-200m 2 / g, 100-175m 2 / g or 125-150m 2 / g. BET surface area can be determined in accordance with ASTM D6556-17.

[0032] The oxidized carbon black used according to the invention is in particular of 10 to 200 m 2 / g, e.g., 50-200m 2 / g, 75-175m 2 / g, 100-140m 2 / g or 125-140m 2 / g. The statistical thickness surface area (STSA) can be determined in accordance with ASTM D6556-17.

[0033] The oxidized carbon black used in accordance with the present invention may have an oil absorption (OAN) measured in accordance with ASTM D2414-18 of 50 to 250 mL / 100 g, e.g., 75 to 225 mL / 100 g, 90 to 200 mL / 100 g, 100 to 175 mL / 100 g, or 110 to 160 mL / 100 g. The oxidized carbon black of the present invention may further have a compressed oil absorption (COAN) of 50 to 150 mL / 100 g, e.g., 75 to 125 mL / 100 g, 90 to 120 mL / 100 g, or 100 to 120 mL / 100 g. The COAN may be determined in accordance with ASTM D3493-18.

[0034] Oxidized carbon blacks according to the present invention can include, but are not limited to, oxidized furnace blacks, oxidized lamp blacks, oxidized gas blacks, or combinations thereof. Preferably, the oxidized carbon blacks include oxidized furnace blacks. Oxidized carbon blacks according to the present invention can include, for example, carbon black grades sold by Orion Engineered Carbons, Inc., under the trade names ECORAX®, CORAX®, or PRINTEX®, which have been subjected to an oxidation treatment as described above.

[0035] As mentioned above, oxidized carbon black is treated with a sulfur-containing primary or secondary amine or its salt to obtain a functionalized carbon black. Thus, this treatment results in the sulfur-containing amine imparting functional groups, such as sulfur-containing moieties and / or amine groups, to the oxidized carbon black, resulting in a chemical change of the oxidized carbon black. The functionalization can be based on various types of interactions between the oxidized carbon black and the sulfur-containing amine, 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 nature of the functional groups present on the surface of functionalized carbon black particles according to the present invention, as understood herein, is not particularly limited and can include those described above with respect to oxidized carbon black and those that can be introduced by sulfur-containing amines, for example, by bonding the sulfur-containing amine to the oxidized carbon black or by reaction of the functional groups of the sulfur-containing amine with the functional groups of the oxidized carbon black. For example, the carboxylic acid groups of the oxidized carbon black can react with the amine groups of the sulfur-containing primary or secondary amine at elevated temperatures, forming an amide bond. Thus, a covalent amide bond can be formed between the oxygen-containing groups on the oxidized surface of the oxidized carbon black 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, carboxylate salt groups, or anhydride groups present on the surface of the oxidized carbon black 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 preferred that the residues of the sulfur-containing primary or secondary amine be bonded to the oxidized carbon black by a covalent bond, such as an amide bond, in the functionalized carbon black.

[0037] As described above, oxidized carbon black material is treated with a sulfur-containing primary or secondary amine or a salt thereof to obtain functionalized carbon black according to the present invention. The terms "sulfur-containing primary or secondary amine or a salt thereof," "sulfur-containing amine," and the like can be used interchangeably throughout the present specification, unless otherwise specified. The sulfur-containing amine component that can be used according to the present invention can include any compound containing both sulfur (in a bound form) and one or more primary or secondary amine groups. A primary amine group refers to a group of the general structure "-NH," and a secondary amine group refers to a group of 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 other words, the primary and / or secondary amine groups can also exist in the corresponding protonated form as ammonium groups.

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

[0039] Preferably, the sulfur-containing primary or secondary amine according to the present invention has the formula R 1 -S x -Z-NR 2 R 3 wherein 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 are each independently selected from hydrogen and a monovalent organic group containing 1 to 20 carbon atoms, such as an alkyl group, an aryl group, or an arylalkyl group. More preferably, Z is an alkylene group containing 1 to 8 carbon atoms. Furthermore, R 1 is C1-C 12 may represent an alkyl group, where optionally one or more hydrogen atoms are replaced by a group of the formula -NR 4 R 5 wherein R 4 and R 5They are each individually selected from monovalent organic groups containing 1 to 20 carbon atoms such as hydrogen and alkyl groups, aryl groups or arylalkyl groups. The integer x is preferably an integer in the range of 2 to 20, for example 2 to 6, and more preferably still, the integer x is equal to 2.

[0040] Preferred sulfur-containing primary or secondary amines according to the present invention have the chemical formula S x (-Z-NR 2 R 3 )2 compounds. Specific suitable sulfur-containing primary or secondary amines that can be used in the present invention can be exemplified by, but are not limited to, cystamine or its salts, for example, each hydrogen halide salt. 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 the carbon black by treatment with the sulfur-containing amine component, a strong chemical interaction of the carbon black particles with the vulcanizable rubber component can be established. For example, the sulfur moiety can form a covalent bond such as a sulfur crosslink with the reaction site of the vulcanizable rubber component such as an ethylenically unsaturated moiety under appropriate reaction conditions.

[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 the sulfur-containing amine component. By this means, 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 to yield (activated) esters or anhydrides. Suitable (activated) esters or anhydrides are known to be more reactive with amines than the corresponding carboxylic acids, and therefore can increase the yield of amide functional groups upon treatment with the sulfur-containing amine component. One or more additional chemical components can 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 increased yield of the reaction product. Other chemical components may be applied to the functionalized carbon black or its precursor to retard or slow down chemical reactions, such as the reaction with the sulfur-containing amine.

[0043] Any one or more additional or other chemical functional groups introduced into the functionalized carbon black by treatment with one or more other chemical moieties can also be utilized to introduce additional chemical reactivity of the functionalized carbon black toward chemical groups other than amines, allowing the functionalized carbon black to interact more strongly with or bond through additional chemical bonds to, for example, rubber materials or other components contained in the respective carbon black-containing compound.

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

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

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

[0047] In addition to the oxidized carbon black and the sulfur-containing amine component, the mixture may optionally contain additional auxiliary components. For example, the mixture may contain a substance that acts as a coupling agent or catalyst for the coupling reaction and / or for removing protecting groups, if present. As further noted above, if the functionalized carbon black is to be provided with additional chemical functional groups, the corresponding reactants may be added before or after contact with the sulfur-containing amine component.

[0048] The reaction conditions in step (C) of the above method can be selected to allow for the formation of an amide bond between the oxidized carbon black and the sulfur-containing amine component. Step (C) can, for example, involve 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). Heat can be applied by any conventional means, such as with a heating rod, a heating plate, or by stirring at high rotor speeds and, respectively, high shear forces. Applying heat with stirring is particularly advantageous when the reaction is induced in situ in the presence of the vulcanizable rubber component.

[0049] As previously mentioned, the reaction of the oxidized carbon black with the sulfur-containing amine component can be carried out in situ, i.e., 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 appropriate vulcanizing agents 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 preparing the vulcanizable rubber composition according to the present invention.

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

[0051] The term "vulcanizable rubber composition" refers to a composition of rubber components, optionally including various additional ingredients conventionally used in the art of rubber compounding, that can be cured by vulcanization to form a vulcanizate. The terms "cure" 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 or vulcanizing agent.

[0052] The vulcanizable rubber component suitable for use in the vulcanizable rubber composition includes one or more rubbers or elastomers containing olefinic unsaturation, i.e., diene-based rubbers or elastomers. The terms "rubber" and "elastomer" can be used interchangeably throughout this specification unless otherwise specified. The rubber component may also include a mixture of rubbers containing olefinic unsaturation with other polymeric materials that do not contain unsaturation, such as thermoplastic or thermosetting polymers. Preferably, however, the rubber component includes only one or more rubbers containing olefinic unsaturation. The phrases "rubber containing olefinic unsaturation" and "diene-based rubber" are used interchangeably and are intended to encompass both natural and synthetic rubbers 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. Without limitation, synthetic diene-based rubber can be any rubber containing at least one diene-based monomer that constitutes rubber, either alone or together with other monomers. Exemplary diene-based rubber materials suitable for use in the practice 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-based rubber materials. Exemplary non-diene-based rubber materials suitable for use in the practice 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 silicon- or tin-bonded rubbers.For example, the rubber may be functionalized with functional groups such as amine, alkoxy, silyl, thiol, thioester, thioether, sulfanyl, mercapto, sulfide, or combinations thereof. The 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), pendant from the polymer backbone, and / or provided within the polymer backbone. The rubber according to the present invention may also be partially crosslinked. Thus, prior to use in a vulcanizable rubber composition, a portion of the polymer chains of the rubber material may be crosslinked with or without a coupling agent. The polymeric material may further be supplied in any form, but typically as bales or chips.

[0053] Preferably, the rubber component comprises a mixture of natural and synthetic diene rubbers. A non-limiting example of a specific rubber material that can be used in the practice of the present invention is Sprintan SLR4630, 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, e.g., 40 to 80 phr. As used herein, the term "phr" refers to the weight parts of the 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, e.g., 0.2 to 5 phr or 0.3 to 3 phr, preferably 0.3 to 2 phr, e.g., 0.5 to 1.5 phr. The sulfur-containing primary or secondary amine may be used in the form of a salt, such as an ammonium or hydrohalide salt.

[0055] The vulcanizable rubber composition of the present invention may optionally further contain at least one vulcanizing agent capable of inducing curing of the rubber. Possible vulcanizing agents include any vulcanizing agent known in the art, such as sulfur and sulfur donors. Suitable sulfur donors for the practice of the present invention include, for example, dithioalkanes, dicaprolactam sulfide, polysulfide polymers, sulfur olefin adducts, thiurams, and sulfonamides having at least two sulfur atoms in the sulfur bridge. Preferably, elemental sulfur can be used. The vulcanizing agent can 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] Additionally, the vulcanizable rubber composition preferably contains a base, such as a basic metal oxide and / or metal hydroxide. Suitable basic metal oxides can be exemplified by alkali metal or alkaline earth metal oxides, such as Na2O, KO, CaO, or MgO. Suitable metal hydroxides can be exemplified by alkali metal or alkaline earth metal hydroxides, such as NaOH, Mg(OH)2, or Ca(OH)2. These components may be included to aid in the in-situ functionalization of the oxidized carbon black with sulfur-containing amines, as they may neutralize acidic by-products, adsorb water, and / or act as cure activators. The basic metal oxides and metal hydroxides can each independently be included in an amount ranging from 0.1 phr to 5 phr, e.g., from 1 phr to 3 phr.

[0057] The vulcanizable rubber composition may further comprise one or more additional filler materials, such as, for example, other carbon blacks, silica, organic silica, carbon nanotubes, carbon fibers, graphite, metal fibers, etc. Carbon blacks useful in this regard can be exemplified by ASTM grade carbon blacks selected from the 100er to 900er series as classified according to ASTM D1765.

[0058] The vulcanizable rubber composition of 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 antioxidants (antioxidants and antiozonants, etc.). Useful primary and secondary vulcanization accelerators include, for example, guanidine, dicarbamate, dithiocarbamate, thiuram, thiourea, 2-mercaptobenzothiazole, benzothiazole sulfonamide, aldehyde amine, amine, disulfide, thiazole, xanthate, and sulfenamide. Specific examples include N-tert-butyl-2-benzothiazylsulfenamide, available commercially under the trade name Rhenogran TBBS-80 from Rhein Chemie Additives, and diphenylguanidine, available commercially under the trade name Rhenogran DPG-80 from Rhein Chemie Additives. Suitable activators include zinc oxide and a fatty acid, such as stearic acid, lauric acid, palmitic acid, oleic acid, or naphthenic acid, in combination. The primary accelerator(s) may be present in the composition in a total amount ranging from 0.05 to 4 phr. The secondary accelerator(s), typically used in smaller amounts than the primary accelerator(s), may be present in the composition in an amount ranging from 0.05 to 3 phr.

[0059] As can be seen, the vulcanizable rubber composition according to the present invention can be utilized 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 made from or containing the vulcanizable rubber composition. 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, seals, profiles, or damping elements. Due to the exceptional combination of low hysteresis and high abrasion resistance, the vulcanizable rubber composition according to the present invention is particularly interesting for producing wear-resistant and fuel-efficient tires or tire components with reduced rolling resistance and heat buildup. Examples of such tires include, but are not limited to, truck tires, passenger 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 process in which the functionalized carbon black is prepared ex-situ or in-situ, i.e., in the absence or presence, respectively, of a vulcanizable rubber component. Accordingly, the present invention also relates to a process for preparing a vulcanizable rubber composition, comprising contacting oxidized carbon black with a sulfur-containing primary or secondary amine or a salt thereof and subjecting the resulting mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing primary or secondary amine or a salt thereof to form the functionalized carbon black, wherein the vulcanizable rubber component is mixed with the oxidized carbon black and the sulfur-containing amine component or the 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.

[0061] In the preferred practice of the present invention, the functionalized carbon black is formed in the presence of the vulcanizable rubber composition. Thus, the vulcanizable rubber component is preferably mixed with the oxidized carbon black and the sulfur-containing amine compound before or while subjecting said mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing amine compound.

[0062] The method can further include adding a basic metal oxide and / or metal hydroxide, such as those described above, during, before, or after mixing the oxidized carbon black and sulfur-containing amine compound with the rubber component. Preferably, the metal oxide and metal hydroxide are added to the carbon black and sulfur-containing amine compound along with the rubber component.

[0063] Mixing can be carried out such that the oxidized carbon black material, the sulfur-containing amine component, the vulcanizable rubber component, and the metal oxide and / or metal hydroxide, if present, and any further optional components, if used, are at least partially mixed together. Preferably, all components are thoroughly mixed together to obtain at least a macroscopically homogeneous mixture.

[0064] The method can include the step of plasticizing the vulcanizable rubber component, for example, by stirring, before mixing the vulcanizable rubber component with the oxidized carbon black and the amine compound. To this end, the vulcanizable rubber component can be provided in a suitable device, such as an internal mixer, and stirred for 2 minutes or less, for example, 1 minute or less, for example, 45 seconds. Subsequently, the oxidized carbon black, the sulfur-containing amine component, and potentially further optional ingredients can 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 rubber processing art. Mixing can be achieved, for example, by mixers, agitators, mills, kneaders, ultrasonic machines, dissolvers, shaker mixers, rotor-stator dispersion assemblies, or high-pressure homogenizers, or combinations thereof. Preferably, mixers with intermeshing or tangential rotor configurations are utilized.

[0066] Mixing can involve heating the components of the mixture to a temperature above room temperature, if necessary. Preferably, however, mixing is carried out without providing additional heat to the mixture beyond that generated by the mixing process itself. The temperature generated from the mixing method can be used to subject the mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing amine component to form functionalized carbon black. Conditions during mixing can be selected, for example, to form an amide bond between the carboxyl group of the oxidized carbon black and the amine group of the sulfur-containing amine component. The temperature of the mixture is thereby maintained typically below 200°C, preferably about 150°C, by gradually or stepwise changing the rotor speed as needed.

[0067] The mixing can be carried out so that the oxidized carbon black reacts with the sulfur-containing amine component during homogenization with the rubber component and any additional components, forming the functionalized carbon black, i.e., so that the homogenization and reaction occur in a single mixing step. However, in a preferred implementation of the present invention, the oxidized carbon black, sulfur-containing amine component, rubber component, and any additional components are at least visually homogenized in a first mixing step, and the resulting mixture is cooled to room temperature before subjecting the components of the mixture to a second mixing step. Depending on the specific mixing conditions in the two mixing steps, the reaction between the oxidized carbon black and the sulfur-containing amine component can occur in the first and / or second mixing steps.

[0068] The duration of the first mixing step can vary. However, depending on the chemical properties of the components, the mixing time can be important. For example, some of the 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 discharge 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 a second mixing step, or can be stored between the two steps. The mixture can be left for a few minutes to several months, for example, for at least 60 minutes, or at least 12 hours. Before the second mixing step, the mixture can be transported to another mixing room and / or another location, for example, to a customer.

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

[0071] After the first mixing step, or the second mixing step, if present, the method for preparing a vulcanizable rubber composition preferably further comprises adding sulfur or a sulfur donor or other vulcanizing agent to the mixture, and optionally one or more activators, one or more accelerators, and additional ingredients conventionally used in the rubber compounding art, as described above. The composition is then preferably mechanically stirred to achieve at least partial, or preferably complete, mixing of the composition. Mixing is typically carried out at a temperature of 10°C to 140°C, more typically 80°C to 120°C, under constant stirring for less than 5 minutes, e.g., less than 3 minutes. Conditions, particularly rotor speed, can be selected so that the temperature of the mixture containing the curative agent is less than 110°C.

[0072] The resulting mixture can then be cured, i.e., vulcanized. By this means, in addition to cross-linking the polymer chains of the rubber material, the functionalized carbon black particles can also be linked to the rubber matrix via the sulfur functional groups introduced to the surface of the carbon black particles by the sulfur-containing amine. This bonding is believed to increase carbon black-elastomer interaction.

[0073] Curing can be carried out using conventional curing means and conditions known in the art of rubber processing. For example, the vulcanizable rubber composition of the present invention can be cured by subjecting the mixture to heat curing conditions, e.g., at a temperature of 120-200°C for 5 minutes to 3 hours. Curing can be carried out, for example, in a curing press at a temperature of 160°C for 60 minutes under a pressure of 120-150 bar.

[0074] The present invention is further described by the following examples. It should be understood that the examples are included for illustrative purposes and should not be construed as limiting the invention. In particular, the scope of protection sought is not limited by the specific examples disclosed below, but rather should be accorded the full scope of the appended claims, including any equivalents thereof. [Example]

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

[0076] The oxidized carbon black (CB) used was EB287, commercially available from Orion Engineered Carbons, Inc., with the properties summarized in Table 1.

[0077] As a reference, a non-oxidized carbon black grade, PRINTEX® 60, commercially available from Orion Engineered Carbons, Inc., was used, the properties of which are also included in Table 1. [Table 1] Applied methods for carbon black characterization

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

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

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

[0081] The oil absorption (COAN) of the compressed samples 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 LECO Instruments thermogravimetric analyzer (TGA-701) according to the following protocol: The sample pan was dried at 650 °C for 30 minutes. The carbon black material was stored in a desiccator with desiccant prior to measurement. The baked sample pan was loaded into the instrument, weighed, and filled with 0.5 g to 10 g of carbon black material. The oven of the TGA instrument containing the loaded sample pan was then gradually heated to 105 °C under automated software control to dry the sample until a constant mass was achieved. The pan was then closed with a lid, and the oven was purged with nitrogen (99.9% by volume) 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 equation:

number

[0084] The carboxylic acid groups per unit mass of carbon black were determined according to the following protocol. The carbon black was dried overnight in a tray dryer set at a temperature of 125°C. The hot carbon black material was removed from the dryer and allowed to cool in a desiccator containing desiccant. Three thoroughly cleaned and dried Erlenmeyer flasks were filled with m CBCarbon black material (V = 1.5 ± 0.1 g) was weighed out and 25 ml of 0.05 molar aqueous sodium hydroxide solution (Titrisol grade diluted with bi-distilled water) was added to each. The air in the flask was replaced with nitrogen gas, and the flask was sealed with a plug and secured by tape with parafilm. The flask was placed in a shaker at 240 rpm overnight. The resulting suspension was then pressure filtered at 5 bar using nitrogen gas. 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 briefly boiled to remove carbonate. The sample was then titrated back to pH 6.5 using 0.05 molar sodium hydroxide solution (Titrisol grade diluted with bi-distilled water). The required volume of sodium hydroxide solution, V, was added. NaOH was measured in mL with an accuracy of three digits after the comma. Two blanks were measured and the required amount of sodium hydroxide solution was averaged (V ブランク,平均 The concentration of carboxyl groups in μmol / g was calculated for all three samples using the following formula, and the resulting values ​​were averaged:

number

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

[0086] Preparation was carried out using a three-step mixing procedure, with each mixing step carried out in an internal mixer with intermeshing rotor geometry (GK1.5E), followed by cooling and further mixing in an open mill.

[0087] First, the rubber components were added to the mixing chamber of the internal mixer and plasticized for 45 seconds. Then, the carbon black filler, Ca(OH), MgO, and cystamine were added. *2HCl was added and mixed for 90 seconds. The ram was lifted, cleaned, and then mixed for an additional 135 seconds. During this step, it was ensured that the maximum temperature did not exceed 160°C.

[0088] After storage for at least 12 hours, the mixture was heated in an internal mixer in a second mixing step by applying maximum rotor speed (104 rpm) to 150°C. 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 the mixture and stirred for 2 minutes to obtain the vulcanizable rubber composition, ensuring that the maximum temperature during this step did not exceed 110°C. [Table 2] Curing of vulcanizable rubber compositions

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

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

[0092] The hardness was measured according to DIN 53 505.

[0093] The tensile strength, elongation at break and modulus 200 were determined according to DIN 53 504.

[0094] Ball rebound was measured according to the test method 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 areas of the test sample were ensured to be smooth and parallel to each other. A steel ball with a diameter of 19 mm was dropped from a drop height of 500 mm through a drop tube onto one of the circular areas 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 top of the impact point on the test sample. The time resolution of the light barrier was 10 -4 The time intervals measured over five experiments per test sample were averaged and applied to calculate the rebound height. The rebound height was then again used to calculate the ball rebound, which corresponds to the percentage ratio of the rebound height to the drop height.

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

[0096] The heat build-up was tested according to DIN 53 533 applying a pretension of 1 MPa and a stroke of 4.45 mm. The chamber temperature was 55°C.

[0097] Loss factor tanδ and complex modulus E * was measured in strain-controlled mode (1±0.5 mm) according to DIN 53 513 at 60 °C and a frequency of 16 Hz on cylindrical specimens (height 10 mm, diameter 10 mm).

[0098] The bound 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 analytical-grade toluene was added to achieve a minimum fill level of 20 mm above the bottom of the flask. The flask was left at a temperature of 23 ± 2 °C for 7 days, whereby the flask was swirled every morning and night. The toluene was replaced after 1–3 days. After 7 days, the basket with the bound rubber gel inside was removed from the flask and the solvent was allowed to evolve overnight in a fume hood. The sample was then dried overnight in a tray dryer until a constant mass was achieved. After cooling to room temperature in a desiccator, the sample was weighed (m(dried gel)). The weight percentage of bound rubber relative to the original sample mass 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 the use of oxidized carbon black in rubber compositions results in rubber articles with significantly improved hysteresis properties, as evidenced by reduced loss factor tan δ, reduced heat buildup, increased ball rebound, and / or increased bound rubber, compared to corresponding reference carbon blacks that have not been oxidatively treated (see contrast between Example 3 and Example 1). This efficacy can be further enhanced when the oxidized carbon black is treated with a sulfur-containing amine, as evidenced by Examples 5-9, compared to Example 3. As shown in Table 3, the use of functionalized sulfur-containing amines further improves indicators of durability and reinforcement, as reflected by a lower amount of abraded material in DIN abrasion tests. Furthermore, the combination of oxidized carbon black with sulfur-containing amines improves both the static and dynamic stiffness of the resulting rubber compounds, which translates into increased modulus 200 and E, respectively. * These effects are not observed, or are observed to a much lesser extent, when the rubber composition contains a reference carbon black that has not been oxidatively treated (see Example 2). Furthermore, the addition of MgO and Ca(OH)2, which do not contain a sulfur-containing amine component, to the rubber composition results in a slight decrease in modulus and an increase in tensile strength, without affecting hysteresis-related properties (see Example 4 vs. Example 3). This demonstrates that the presence of both the sulfur-containing amine and the oxidized carbon black that reacts with it is important to achieve the above-mentioned beneficial combination of properties. Particularly favorable properties are obtained when a relatively small amount of functionalizing agent is used relative to the amount of carbon black (see Example 4 vs. Example 5).

Claims

1. Functionalized carbon black obtained by treating oxidized carbon black with sulfur-containing primary or secondary amines or their salts.

2. 10. The functionalized carbon black of claim 1, wherein the residue of a sulfur-containing primary or secondary amine is attached to the oxidized carbon black by a covalent bond, such as an amide bond.

3. 3. The functionalized carbon black of claim 1, 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. The sulfur-containing primary or secondary amine is represented by the formula R １ -S ｘ -Z-NR ２ R ３ or S ｘ (-Z-NR ２ R ３ ) ２ wherein 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 are each independently selected from hydrogen and monovalent organic groups containing 1 to 20 carbon atoms, where Z is preferably an alkylene group containing 1 to 8 carbon atoms, x is preferably an integer in the range of 2 to 20, e.g., 2 to 6, preferably 2, and R １ is preferably C １ -C １２ represents an alkyl group, where optionally one or more hydrogen atoms are substituted with an amine group -NR ４ R ５ and R ４ and R ５ The functionalized carbon black of any one of claims 1 to 3, wherein each of R, R, and R is individually selected from hydrogen and monovalent organic groups containing from 1 to 20 carbon atoms.

5. 5. The functionalized carbon black according to any one of claims 1 to 4, wherein the sulfur-containing primary or secondary amine or salt thereof comprises cystamine or a salt thereof, such as the respective ammonium halide salt.

6. The functionalized carbon black of any one of claims 1 to 5, wherein the oxidized carbon black comprises carboxylic acid groups in an amount of at least 50 μmol / g, for example in the range of 100 to 300 μmol / g.

7. A method for making 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 salt thereof; (C) subjecting the resulting mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing primary or secondary amine or salt thereof.

8. 8. The method of claim 7, wherein step (C) comprises heating the mixture to a temperature of at least 100°C, such as from 100°C to 160°C, for at least 1 minute, such as from 2 to 10 minutes.

9. A vulcanizable rubber composition comprising: (i) a vulcanizable rubber component; (ii) oxidized carbon black, and (iii) a sulfur-containing primary or secondary amine or a salt thereof; Alternatively, it comprises 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 a salt thereof (iii).

10. 10. The vulcanizable rubber composition of claim 9, 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 a combination thereof.

11. 11. The vulcanizable rubber composition according to claim 9 or 10, 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, preferably 0.3 to 2 phr.

12. Sulfur-containing primary or secondary amines are used in the form of their corresponding ammonium salts, and / or the composition contains basic metal oxides or hydroxides, such as Ca(OH) ２ and / or MgO.

13. a method for preparing a vulcanizable rubber composition comprising contacting oxidized carbon black with a sulfur-containing primary or secondary amine or salt thereof and subjecting the resulting mixture to conditions under which the oxidized carbon black reacts with the sulfur-containing primary or secondary amine or salt thereof to form a functionalized carbon black; Here, a vulcanizable rubber component is mixed with oxidized carbon black and a 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.

14. An article prepared from the vulcanizable rubber composition of any one of claims 9 to 12.

15. 15. The article of claim 14, which is a tire, a tire component such as a tire tread, 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.

16. Use of a sulfur-containing primary or secondary amine or salt thereof for the surface modification of oxidized carbon black and / or as a coupling agent in a vulcanizable rubber composition containing carbon black.

17. Use of a sulfur-containing primary or secondary amine or salt thereof in a carbon black-containing vulcanizable rubber composition to reduce the loss factor tan δ at 60°C, and / or reduce heat buildup, and / or increase bound rubber, and / or improve abrasion resistance, compared to a corresponding carbon black-containing vulcanizable rubber composition that does not contain the sulfur-containing primary or secondary amine or functionalized carbon black derived therefrom.

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