ALKOXYLATED NITROGEN COMPOUNDS AS REPLACEMENTS FOR GUANIDINES IN RUBBER

Abstract

The present invention relates to a rubber composition comprising at least one alkoxylated nitrogen compound, particularly as a replacement for a guanidine compound. The present invention also relates to a method for vulcanizing such a rubber composition, as well as articles comprising this vulcanized composition, including tires. Finally, the present invention relates to the use of an alkoxylated nitrogen compound as a replacement for a guanidine compound.

Description

Title of the invention: Alkoxylated nitrogen compounds as replacement agents GUANIDINES IN RUBBER Scope of the invention

[0001] The present invention relates to the field of rubbers. More particularly, the present invention relates to a rubber composition comprising at least one alkoxylated nitrogen compound, notably as a replacement for a guanidine compound. The present invention also relates to a method for vulcanizing such a rubber composition, as well as articles comprising this vulcanized composition, particularly tires. Finally, the present invention relates to the use of an alkoxylated nitrogen compound as a replacement for a guanidine compound. Technical background

[0002] Tires used today are primarily composed of natural and / or synthetic rubber. Given current environmental challenges, rubber must address complex issues that integrate performance with environmental friendliness and durability. Tires, and in particular their treads, must therefore exhibit good wear resistance, good traction, and low rolling resistance, while simultaneously improving their environmental impact.

[0003] One of the solutions used by tire manufacturers lies in rubber compounds with reduced rolling resistance, which helps to decrease fuel consumption and obtain better grip for safer driving. They have also developed such rubber compounds by introducing a reinforcing filler such as silica.

[0004] The formulation of these compositions may require the use of a coupling agent to bind the reinforcing filler to the elastomer. This coupling step is sometimes called "silanization" when the coupling agent is a silane. It precedes the steps of adding vulcanization accelerators and then shaping and vulcanizing the rubber. To promote efficient coupling and / or accelerate vulcanization, guanidine compounds are generally added to these rubber compositions, in particular 1,3-diphenyl guanidine (known as DPG; CAS No. 102-06-7).

[0005] DPG offers numerous advantages. It accelerates the coupling step and partially neutralizes the silica, thus limiting the adsorption of accelerators by the silica. It also accelerates the vulcanization step (acting as a secondary accelerator) while maintaining a suitable pre-vulcanization time (known as roasting time).

[0006] However, the use of guanidine compounds poses other problems during their implementation. Indeed, these compounds, and in particular DPG, are suspected of being reprotoxic and decompose within the temperature ranges at which the compositions are formulated. Their decomposition leads to the release of aniline, which is a toxic compound by ingestion, inhalation, and skin contact.

[0007] There is therefore a need for replacement agents for guanidine compounds in rubber. More specifically, there is a need for replacement agents for guanidine compounds that are less harmful, in particular those that do not generate aniline or nitrosamine. There is also a need for replacement agents for guanidine compounds that are bio-based and not petroleum-based.

[0008] Thus, an objective of the present invention is to provide replacement agents for guanidine compounds, and more particularly for DPG, in rubber.

[0009] Another objective of the present invention is to provide replacement agents for guanidine compounds, and more particularly for DPG, in rubber which are less harmful, preferably bio-based, while preserving the properties of the rubber.

[0010] Another objective of the present invention is to provide replacement agents for guanidine compounds that are easily handled and suitable for rubber preparation and vulcanization processes. Brief description of the invention

[0011] The present invention meets all or part of the above objectives.

[0012] The present inventors have made a surprising discovery that alkoxylated nitrogen compounds of general formula (I) can be used as replacements for guanidine compounds in rubber. Indeed, these alkoxylated nitrogen compounds make it possible to obtain rubbers with similar, or even improved, rheometric, mechanical, and / or dynamic properties compared to rubbers obtained using guanidine compounds such as DPG. Satisfactory rheometric properties can also be observed by reducing the amount of alkoxylated nitrogen compound.

[0013] Furthermore, the vulcanization of rubber is faster (t90) without degrading the pre-vulcanization time (curing time) with the compounds according to the invention. In particular, they can be used as vulcanization accelerators and / or as filler dispersion aids.

[0014] Alkoxylated nitrogen compounds of general formula (I) are also compatible with other vulcanization accelerators to form an effective crosslinking system. Thus, they are particularly preferred in combination with thiurams.

[0015] Another advantage of these alkoxylated nitrogen compounds lies in the fact that they can be obtained from bio-based raw materials. "Bio-based raw materials" refers to raw materials derived from biomass. "Biomass" includes, in particular, organic matter of plant, animal, bacterial, or fungal origin (usable as an energy source). Biomass can be considered a renewable raw material when its consumption is at least equal to its regeneration. For example, the Noramox® product range marketed by Arkema, which includes alkoxylated nitrogen compounds such as those according to the invention, is prepared from fatty acid derivatives or esters derived from biomass.

[0016] These compounds can also be easily formulated in pre-dispersed form in masterbatches. These formulations, generally presented in the form of granules or strips, are easily handled by operators, do not generate dust, mix quickly in rubbers, and do not require any changes to production lines, which represents an advantage for manufacturers.

[0017] Thus, the present invention relates to a rubber composition comprising:

[0018] (a) at least one elastomer, preferably at least one diene elastomer,

[0019] (b) a reinforcing charge,

[0020] (c) possibly a charge-elastomer coupling agent,

[0021] (d) at least one alkoxylated nitrogen compound of the following general formula (I), or one of its salts:

[0022] in which:

[0023] - m is an integer greater than or equal to 1, preferably between 1 and 20;

[0024] - n is an integer greater than or equal to 1, preferably between 1 and 20;

[0025] - A is a linear or branched (C2-Ci0)alkylene group, optionally substituted by one or more (Ci-C24)alkyl or (C6-Ci0)aryl group(s);

[0026] - X is either a -CH2- group or a -C(=O)- group; and

[0027] - R is a linear or branched (C6-C30)alkyl group, which may contain one or several unsaturations; and

[0028] (e) a crosslinking system, preferably comprising a thiuram;

[0029] said composition comprising less than 0.5 pc of guanidic compound.

[0030] The present invention also relates to a method for vulcanizing a rubber composition such as that according to the invention, comprising the following steps:

[0031] 1) a coupling step comprising the mixing of:

[0032] (a) at least one elastomer, preferably at least one diene elastomer,

[0033] (b) a reinforcing charge,

[0034] (c) possibly a charge-elastomer coupling agent, and

[0035] (f) possibly other additives;

[0036] 2) an acceleration step comprising the addition of the crosslinking system (e) to the mixture obtained at the end of step 1); and

[0037] 3) a vulcanization step of the mixture obtained at the end of step 2), in order to to obtain a vulcanized rubber composition;

[0038] in which at least one alkoxylated nitrogen compound of general formula (I) such as according to the invention is added during step 1) and / or during step 2).

[0039] The present invention relates to an article, preferably a tire, comprising a rubber composition such as according to the invention vulcanized, preferably by the vulcanization process according to the invention.

[0040] The present invention relates to the use of an alkoxylated nitrogen compound of the following general formula (I), or one of its salts:

[0041] in which:

[0042] - m is an integer greater than or equal to 1, preferably between 1 and 20;

[0043] - n is an integer greater than or equal to 1, preferably between 1 and 20;

[0044] - A is a linear or branched (C2-Ci0)alkylene group, optionally substituted by one or more (Ci-C24)alkyl or (C6-Ci0)aryl group(s);

[0045] - X is either a -CH2- group or a -C(=O)- group; and

[0046] - R is a linear or branched (C6-C30)alkyl group, which may contain one or several unsaturation(s), as a replacement for a guanidic compound, especially in a rubber composition, preferably as defined below (and especially as a vulcanization accelerator).

[0047] Preferably, the rubber composition comprises:

[0048] (a) at least one elastomer, preferably a diene elastomer,

[0049] (b) silica as a reinforcing filler,

[0050] (c) possibly a silica-elastomer coupling agent,

[0051] (d) at least one alkoxylated nitrogen compound as defined below,

[0052] (e) a crosslinking system comprising a thiuram; and

[0053] said composition comprising less than 0.5 pc of guanidic compound.

[0054] More preferably, the rubber composition comprises:

[0055] (a) at least one elastomer, selected from the group consisting of polyisoprenes, natural rubbers (NR), butadiene rubbers (BR), styrene-butadiene rubbers (SBR) and their mixtures, preferably SBR / BR mixtures, preferably SSBR / BR mixtures,

[0056] (b) silica as a reinforcing filler,

[0057] (c) a silane, preferably a polysulfide silane, as a silica- coupling agent elastomer,

[0058] (d) at least one alkoxylated nitrogen compound as defined below,

[0059] (e) a crosslinking system comprising sulfur, a vulcanization accelerator primary sulfur compound and thiuram as a secondary accelerator; and

[0060] said composition comprising less than 0.5 pc of guanidic compound. Detailed description of the invention

[0061] In this application, it is understood that "pc" corresponds to "part percent of elastomer": one pc corresponds to one part of an ingredient per hundred parts of elastomer, by mass. For example: a dosage of 10 pc of an ingredient is equivalent to 100 g of elastomer plus 10 g of the ingredient ("pc" corresponds to "phr" in English).

[0062] It is understood that the rubber compositions according to the invention correspond to the so-called "raw" or non-crosslinked or non-vulcanized state (i.e., before curing), or to the so-called "cured" or crosslinked or vulcanized state (i.e., vulcanization is a crosslinking reaction). These include, in particular, vulcanizable or vulcanized rubber compositions.

[0063] Alkoxylated nitrogen compounds such as those according to the invention make it possible, in particular, to replace guanidine compounds in rubber compositions while preserving the properties of the latter. Thus, the composition according to the invention comprises less than 0.5 parts per annum of guanidine compound, preferably the composition comprises an amount of guanidine compound strictly less than 0.5 parts per annum. More particularly, said composition comprises less than 0.45 parts per annum, preferably less than 0.4 parts per annum, more preferably less than 0.3 parts per annum, even more preferably less than 0.2 parts per annum, and most preferably less than 0.1 parts per annum of guanidine compound. Advantageously, said composition does not substantially comprise any guanidic compound (i.e., it may comprise a guanidic compound in trace amounts), or even does not comprise any guanidic compound.

[0064] Thus, the use of alkoxylated nitrogen compounds as described in the invention, as a replacement for guanidine compounds, is also part of the invention. Preferably, these compounds are used as replacements for guanidine compounds as vulcanization accelerators, in particular as primary and / or secondary accelerators.

[0065] The term “guanidine compound” or “guanidine” means an organic compound bearing a guanidine chemical function (-HN-C(=NH)-NH-), such as those commonly known in the field of rubber, particularly as vulcanization accelerators. Examples include diphenylguanidine (DPG) or diorthotolylguanidine (CAS: 97-39-2, DOTG), more specifically DPG.

[0066] The composition according to the invention can be used alone or in a mixture with any other usable rubber composition for the manufacture of articles, preferably for the manufacture of tires. The manufacture of tire treads or the retreading of worn tires is preferred. Said rubber composition is particularly useful in the manufacture of articles such as tires, automotive hoses such as fluid transport hoses, engine mounts, bushings, transmission belts, printing rollers, shoe heels and soles, floor tiles, swivel casters, seals and gaskets, conveyor belt covers, hard rubber battery cases, automotive floor mats, truck mud flaps, ball mill linings, or windshield wiper blades.

[0067] Advantageously, the rubber compound is used in a tire as a component of all or some of the tire's parts. In particular, said compound is that of all or part of a layer of a tire, such as the tread, the tire belt plies, the carcass ply, the tire sidewalls, or any other layer, preferably the tread. The tire tread refers specifically to the entire rubber layer in contact with the ground (i.e., over its full thickness) or a part thereof, particularly when it is composed of several layers.

[0068] The invention also relates to an article as mentioned above, preferably a tire, comprising the rubber composition according to the invention vulcanized. Said tire may comprise said rubber composition in all or part of one or more of its various layers, such as the tread of the tread, the tire belt plies, the carcass ply, the tire sidewall or any other layer.

[0069] In particular, the tire according to the invention is chosen from tires intended to equip a two-wheeled vehicle, a passenger vehicle, or even a so-called "heavy goods vehicle" (i.e., metro, bus, off-road vehicles, road transport vehicles such as trucks, tractors, trailers), or even airplanes, civil engineering, agricultural, or handling equipment.

[0070] Alkoxylated nitrogen compound(s) of general formula (I):

[0071] The composition according to the invention comprises at least one, preferably one, alkoxylated nitrogen compound of the following general formula (I), or one of its salts:

[0072] in which:

[0073] - m is an integer greater than or equal to 1, preferably between 1 and 20;

[0074] - n is an integer greater than or equal to 1, preferably between 1 and 20;

[0075] - A is a linear or branched (C2-Ci0)alkylene group, optionally substituted by one or more (Ci-C24)alkyl or (C6-Ci0)aryl group(s);

[0076] - X is either a -CH2- group or a -C(=O)- group; and

[0077] - R is a linear or branched (C6-C3o)alkyl group, which may contain one or several unsaturations, preferably one or two unsaturations.

[0078] The term "alkyl" refers in particular to monovalent saturated aliphatic hydrocarbons, which may be linear, branched, or cyclic, preferably linear or branched. "Branched" means that an alkyl group is substituted on the main alkyl chain. "Alkylene" means, in particular, an alkyl radical as defined above but divalent.

[0079] The term "(C6-CiO)aryl" refers in particular to monovalent hydrocarbon aromatic compounds, comprising 6 to 10 carbon atoms, monocyclic, bicyclic or tricyclic, in particular phenyl and naphthyl.

[0080] Preferably, R is a linear or branched (C8-C24)alkyl group, more preferably a linear or branched (Ci2-Ci8)alkyl group, which may contain one or more unsaturates, preferably one or two. In particular, R is linear. That is to say, R may be a linear or branched, saturated or unsaturated hydrocarbon chain comprising from 6 to 30 carbon atoms, Preferably 8 to 24 carbon atoms, and preferably 12 to 18 carbon atoms. "Unsaturation" refers in particular to a C=C double bond.

[0081] Preferably, A is a linear or branched (C2-C6)alkylene group, more preferably a linear or branched (C2-C4)alkylene group.

[0082] In particular, m is between 1 and 10, more particularly between 1 and 6 and even more particularly between 1 and 4, for example m is equal to 1. In particular, n is between 1 and 10, more particularly between 1 and 6 and even more particularly between 1 and 4, for example n is equal to 1. Preferably, m is equal to n.

[0083] Preferably, X is a -CH2- group.

[0084] The preferred compounds according to the invention are alkoxylated fatty amines, in particular ethoxylated ones. More particularly, said alkoxylated nitrogen compound has the general formula (IA), or one of its salts: (AI), 'x ï ......... JK HO' - CH

[0085] in which X and R are as defined above.

[0086] Preferably, the alkoxylated nitrogen compound(s) may be chosen from the following compounds, their salts and mixtures thereof: - stearyldiethanolamine (CAS No. 10213-78-2), and its unsaturated analogues including oleyl bis-(2-hydroxyethyl)amine (CAS No. 25307-17-9), N-Oleyldiethanolamine (CAS No. 13127-82-7) and 2,2'-(9-Octadecen-l-ylimino)bis[ethanol] (CAS No. 25307-17-9); - 2,2'-(Octylimino)bis[ethanol] (CAS No. 15520-05-5), and its analogues unsaturated; - lauryldiethanolamine (CAS No. 1541-67-9), and its unsaturated analogues; - 2,2'-(Hexadecylimino)bis[ethanol] (CAS No. 18924-67-9), and its unsaturated analogues; - 2,2'-(Tetradecylimino)bis[ethanol] (CAS No. 18924-66-8), and its unsaturated analogues; - 2,2-Decylliminobis[ethanol] (CAS No. 18924-65-7), and its unsaturated analogues; and - 2,2'-[(13Z)-13-Docosen-l-ylimino]bis [ethanol] (CAS No. 103612-43-7).

[0087] By "unsaturated analogue", in particular, is meant a compound having a molecular structure identical to the corresponding saturated compound (i.e. the same nature, the same number and the same arrangement of atoms), with the exception of the R group which retains the same carbon skeleton but includes one or more unsaturations.

[0088] Said alkoxylated nitrogen compounds may be used in free form or in salt form, particularly as ammonium salts. For example, the salt may be an ammonium salt formed by reaction with a carboxylic acid or diacid (acetate salt, adipate salt, for example), a phosphoric acid, or a hydrohalogenated acid (HCl, HBr, HI). The salt may also be a quaternary ammonium salt formed by reaction between the alkoxylated nitrogen compound and a carbon halide derivative such as, for example, methyl chloride, methyl iodide, methyl bromide, or benzyl chloride, iodide, or bromide. It is understood that when reference is made to alkoxylated nitrogen compounds, salts are included in this general term.

[0089] These alkoxylated nitrogen compounds can be used alone or in mixtures. For example, they are marketed as mixtures by Arkema under the Noramox® range. The following commercial products are particularly noteworthy:

[0090] [Tables 1] Radical Product R Noramox® C2 Mixture in C12-C14 Noramox® S2 Mixture in Ci6-Ci8 Noramox® 02 c18 Noramox® SH2 Mixture in Ci6-Ci8 Noramox® 18D2 c18 Noramox ®C5 Mixture in C12-C14 Noramox® 05 c18 Noramox® S5 Mixture in Ci6-Ci8 Noramox® S7 Mixture in Ci6-Ci8 Noramox® Cil Mixture in C12-C14 Noramox® S11 Mixture in Ci6-Ci8

[0091] In particular, the total quantity of the alkoxylated nitrogen compound(s) in the composition is between 0.10 and 10 pc, in particular between 0.10 and 5 pc, preferably between 0.25 and 3 pc, preferably again between 0.5 and 2 pc.

[0092] Masterbatches:

[0093] Vulcanizing additives such as the alkoxylated nitrogen compounds according to the invention are conventionally used in relatively small doses compared to other ingredients. For optimal rubber properties, Their distribution in the vulcanizing mixture must be homogeneous. For this reason, it is advantageous to introduce them into the rubber composition as a masterbatch. Thus, the alkoxylated nitrogen compound(s) can be in the form of a masterbatch.

[0094] These masterbatches are generally in the form of strips, tablets, or granules. These so-called pre-dispersed forms are easy to handle, unlike powders or liquids. Furthermore, the physical presentation as a masterbatch improves the compatibility between the alkoxylated nitrogen compound(s) of general formula (I) and the composition, and thus improves their dispersion within the latter.

[0095] In the present application, the quantity of each ingredient of the master mix is ​​expressed in mass, relative to the total mass of the master mix (% ​​mass) and not in pieces.

[0096] Any type of masterbatch known to a person skilled in the art may be used.

[0097] The masterbatches, preferably thermoplastic, include in particular: - at least one support, which is an elastomer, for example as defined for the rubber composition according to the invention; - at least one alkoxylated nitrogen compound as per the invention; - possibly a load, for example such as defined for the rubber composition according to the invention; - possibly a plasticizer; and - possibly one or more additional additives.

[0098] Among the fillers, we can mention reinforcing or diluting fillers such as silica and / or carbon black or other mineral or organic fillers.

[0099] The plasticizer can be an oil (paraffinic, naphthenic, hydrogenated naphthenic, or of vegetable origin, i.e., derived from fatty acid derivatives), or a saturated or unsaturated phthalate plasticizer. It notably facilitates the incorporation of other additives and / or allows for viscosity adjustment.

[0100] Additional additives may include desiccants, carbon nanotubes (CNTs), anti-sticking agents and colorants.

[0101] The fillers are generally between 0 and 60% by mass each, more preferably between 0 and 50% by mass each, relative to the total mass of the mastermix. The plasticizers are generally between 0 and 15% by mass, relative to the total mass of the mastermix. The other additives may be between 0 and 10% by mass, more preferably between 0 and 2% by mass, relative to the total mass of the mastermix.

[0102] The masterbatches may include any type of elastomer and in particular those mentioned for the rubber composition according to the invention.

[0103] In particular, these masterbatches use as a support at least one elastomer, in particular a mixture of elastomers, selected from: - an isoprene rubber, such as natural rubber NR (for Natural Rubber) or IR (synthetic polyisoprenes); - a butyl rubber IIR (isobutylene - isoprene copolymers); - an EPDM (ethylene-propylene-diene monomer terpolymer); - an EPR (ethylene-propylene rubber); - a BR (butadiene rubber); - an SBR (styrene-butadiene rubber) such as SSBR (Solution-Styrene Butadiene Rubber) and ESBR (Styrene Butadiene Emulsion Rubber); - an NBR (nitrile-butadiene rubber); - a copolymer of ethylene and an alpha-olefin (as defined below); - a copolymer of ethylene and an unsaturated carboxylic acid ester such as EVA (ethylene-vinyl acetate copolymer) (as defined below); - a copolymer chosen from among the ethylene / alkyl (meth)acrylate / maleic anhydride copolymers such as EMA (ethylene-methyl acrylate copolymer); - a block copolymer such as styrene-butadiene-styrene (SBS), styrene-ethylene / butylene-styrene (SEBS) or styrene-isoprene-styrene (SIS), possibly grafted; and - a POE (polyolefin elastomer).

[0104] Examples of alpha-olefins include propylene, butene, hexene or octene.

[0105] Examples of copolymers of ethylene and unsaturated carboxylic acid esters include alkyl (meth)acrylates in which the alkyl group contains from 1 to 24 carbon atoms. Advantageously, examples of acrylates or methacrylates are methyl methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate. These esters can be introduced by grafting (onto polyethylenes) or by direct copolymerization.

[0106] At least one copolymer of ethylene and an alpha-olefin and at least one copolymer of ethylene and an unsaturated carboxylic acid ester may also be used as a support. Such supports are described in document WO 2008 / 074962.

[0107] An elastomer such as those mentioned above can also be used, substituted by: - ​​one or more siloxy group(s), for example of formula -Si(ORa); with Ra = H or an alkyl group, for example methyl or ethyl; - one or more carboxymercaptan group(s), for example as defined in US application 2013 / 0281609.

[0108] Preferably, said elastomer is selected from the group consisting of SBRs (styrene-butadiene rubbers) such as SSBR (Solution-Styrene-Butadiene Rubber) and ESBR (Emulsion-Styrene-Butadiene Rubber), EPDMs (ethylene-propylene-diene monomer terpolymers), BRs (butadiene rubbers), POEs (polyolefin elastomers), NR (natural rubber) and their mixtures such as SBR / BR. In particular, POEs and SBRs such as ESBR are preferred.

[0109] Preferably, the master mixture comprises an elastomer as defined above, at least one alkoxylated nitrogen compound as according to the invention and a reinforcing filler, preferably silica.

[0110] More preferably, the masterbatch comprises: - at least one elastomer chosen from the group consisting of SBR (styrene-butadiene rubbers), EPDM (ethylene-propylene-diene monomer terpolymers), BR (butadiene rubbers), POEs (polyolefin elastomers), NR (natural rubber) and their mixtures such as SBR / BR; - at least one alkoxylated nitrogen compound as per the invention; and - silica.

[0111] The total quantity of elastomer(s) can be from 20 to 80%, preferably from 20 to 50%, preferably still from 5 to 35% by mass, relative to the total mass of the master mixture.

[0112] The total amount of alkoxylated nitrogen compound(s) may be from 20 to 80%, preferably from 30 to 60% by mass, relative to the total mass of the master mixture.

[0113] The masterbatches may include all or part of the total amount of alkoxylated nitrogen compound(s) to be incorporated into the rubber composition, preferably all of the alkoxylated nitrogen compound(s).

[0114] The masterbatches of the invention can be manufactured using techniques from both the rubber and thermoplastics industries. Single or twin screw extruders, internal mixers, and possibly roller mixers can thus be used. Elastomer(s):

[0115] The compositions according to the invention may contain a single elastomer or a mixture of several elastomers. Elastomers are also commonly called "rubbers".

[0116] The elastomers used are more particularly based on unsaturated materials such as natural and / or synthetic rubbers. Preferably, The said elastomer(s) is / are a / the diene elastomer(s). By "diene elastomer", we mean in particular an elastomer derived at least in part (i.e., a homopolymer or a copolymer) from diene monomers (monomers bearing two carbon-carbon double bonds, conjugated or not).

[0117] Diene elastomers can be classified into two categories: "essentially unsaturated" or "essentially saturated".

[0118] The term "essentially unsaturated" generally refers to a diene elastomer derived at least in part from conjugated diene monomers, having a proportion of diene-derived motifs (conjugated dienes) greater than 15% by mole. Within the category of "essentially unsaturated" diene elastomers, the term "highly unsaturated" diene elastomer specifically refers to a diene elastomer having a proportion of diene-derived motifs (conjugated dienes) greater than 50% by mole.

[0119] Essentially saturated diene elastomers (low or very low rate of diene motifs, less than 15% by moles) are for example butyl rubbers or copolymers of dienes and alpha-olefins of the EPDM type.

[0120] The diene elastomers according to the invention can be essentially unsaturated or essentially saturated, preferably strongly unsaturated.

[0121] Examples of conjugated dienes include 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and mixtures thereof. Examples of copolymers of such conjugated dienes with monomers include styrene, alpha-methylstyrene, acetylene, vinylacetylene, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, vinyl acetate, and mixtures thereof.

[0122] Highly unsaturated elastomers include, in particular, natural rubber (NR), cis-polyisoprene, butadiene rubber (BR), styrene-butadiene rubber (SBR), styrene-isoprene copolymers, isoprene-butadiene copolymers, styrene-isoprene-butadiene terpolymers, polychloroprene, chloro-isobutene-isoprene, nitrile-chloroprene, styrene-chloroprene, poly(acrylonitrile butadiene) and mixtures thereof; preferably butadiene rubber, styrene-butadiene rubber and mixtures thereof.

[0123] In addition, mixtures of two or more highly unsaturated diene elastomers with elastomers having less unsaturation such as EPDM, EPR, butyl or halogenated butyl rubbers are also covered by the invention.

[0124] In particular, the elastomer(s) is / are chosen from: - an isoprene rubber, such as natural rubber NR (for Natural Rubber) or IR (synthetic polyisoprenes); - a butyl rubber IIR (isobutylene - isoprene copolymer); - an EPDM (ethylene-propylene-diene monomer terpolymer); - an EPR (ethylene-propylene rubber); - a BR (butadiene rubber); - an SBR (styrene-butadiene rubber) such as SSBR (Solution-Styrene Butadiene Rubber) and ESBR (Styrene Butadiene Emulsion Rubber); - an NBR (nitrile-butadiene rubber); - a copolymer of ethylene and an alpha-olefin (as defined below); - a copolymer of ethylene and an unsaturated carboxylic acid ester such as EVA (ethylene-vinyl acetate) (as defined below); - a copolymer chosen from among the ethylene / alkyl (meth)acrylate / maleic anhydride copolymers such as EMA (ethylene-methyl acrylate copolymer); - a block copolymer such as styrene-butadiene-styrene (SBS), styrene-ethylene / butylene-styrene (SEBS) or styrene-isoprene-styrene (SIS), possibly grafted; - a POE (polyolefin elastomer); and - their mixtures.

[0125] Examples of alpha-olefins include: propylene, butene, hexene or octene.

[0126] Examples of copolymers of ethylene and unsaturated carboxylic acid esters include alkyl (meth)acrylates in which the alkyl group contains from 1 to 24 carbon atoms. Advantageously, examples of acrylates or methacrylates are methyl methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate. These esters can be introduced by grafting (onto polyethylenes) or by direct copolymerization.

[0127] At least one copolymer of ethylene and an alpha-olefin and at least one copolymer of ethylene and an unsaturated carboxylic acid ester can also be used as an elastomer. Such elastomers are described in document WO 2008 / 074962.

[0128] An elastomer such as those mentioned above may also be used, substituted by:

[0129] - one or more siloxy group(s), for example of formula -Si(ORa); with Ra = H or an alkyl group, for example methyl or ethyl;

[0130] - one or more carboxymercaptan group(s), for example such as defined in US application 2013 / 0281609.

[0131] NR or partially epoxy-coated diene rubbers can also be used.

[0132] Preferably, said elastomer is chosen from the group consisting of polyisoprenes, NR (natural rubbers), SBR (styrene-butadiene rubbers) such as SSBR (Solution-Styrene-Butadiene Rubber) and the ESBR (Styrene Butadiene Emulsion Rubber), EPDM (ethylene-propylene-diene monomer terpolymer), BR (butadiene rubbers), POEs (polyolefin elastomers) and their mixtures such as SBR / BR and even more preferably SSBR / BR.

[0133] According to a preferred embodiment, the diene elastomer is chosen from the group consisting of polyisoprenes, natural rubbers (NR), butadiene rubbers (BR), styrene-butadiene rubbers (SBR) such as SSBR (Solution-Styrene Butadiene Rubber) and ESBR (Styrene-Butadiene Emulsion Rubber), and mixtures thereof, preferably SBR / BR mixtures, more preferably SSBR / BR mixtures. Reinforcing charge:

[0134] The composition according to the invention comprises a reinforcing filler. Any type of reinforcing filler known to those skilled in the art may be used, and in particular silica, carbon black or a mixture of silica and carbon black.

[0135] Thus, preferably, the reinforcing filler comprises predominantly an inorganic reinforcing filler, preferably silica (i.e., more than 50% by mass of inorganic filler, preferably silica, relative to the total mass of the reinforcing filler). More preferably, the reinforcing filler is made of silica.

[0136] Silica can be of any type known to be useful in reinforcing rubber compositions. Examples of suitable silica fillers include, for example, silica, precipitated silica, amorphous silica, vitreous silica, fumed silica, fused silica, synthetic silicates such as aluminum silicates, alkaline earth metal silicates such as magnesium silicate and calcium silicate, natural silicates such as kaolin and other natural silicas, or silicas obtained by combustion of a natural element, such as silica obtained from the combustion of rice husks.

[0137] Highly dispersed silicas having, for example, BET surfaces of about 5 to about 1000 m² / g and preferably of about 20 to about 400 m² / g, preferably again between 60 and 300 m² / g, and primary particle diameters of about 5 to about 500 nm and preferably of about 10 to about 400 nm are also useful. These highly dispersed silicas can be prepared, for example, by precipitation of silicate solutions or by flame hydrolysis of silicon halides.

[0138] Silicas can also be present in the form of mixed oxides with other metallic oxides such as, for example, oxides of Al, Mg, Ca, Ba, Zn, Zr, Ti and others. Silicas from the "Ultrasil®" range are used, for example. marketed by the company Evonik such as ULTRASIL® 4000 GR, ULTRASIL® 5000 GR, ULTRASIL® 5500 GR, ULTRASIL® VN 2, ULTRASIL® VN 2 GR, ULTRASIL® 6100 GR, ULTRASIL® 7000 GR, ULTRASIL® VN 3, ULTRASIL® VN 3 GR, ULTRASIL® 7800 GR, ULTRASIL® 7500 GR, ULTRASIL® 9500 GR and ULTRASIL® 9100 GR.

[0139] Mixtures of two or more silica fillers can be used as reinforcing fillers.

[0140] Carbon black fillers may also be used. Suitable carbon black fillers include any of the commercially available carbon blacks known to those skilled in the art. Examples of carbon blacks include furnace black, channel black, and lamp black. Carbon blacks obtained by pyrolysis of organic plant derivatives or by pyrolysis of raw or vulcanized rubber parts may also be used.

[0141] In particular, so-called pneumatic grade blacks can be used. Among these, we will mention more particularly the reinforcing carbon blacks of the 100, 200 or 300 series (ASTM grades), such as for example blacks N 115, N134, N234, N326, N330, N339, N347, N375, or, depending on the applications intended, blacks of higher series (for example N660, N683, N772).

[0142] The reinforcing filler is incorporated into the rubber composition in quantities that vary widely.

[0143] Generally, the amount of inorganic reinforcing filler such as silica can vary from about 5 to about 150 pc, preferably from about 10 to about 100 pc and more preferably from about 15 to about 90 pc.

[0144] Carbon blacks, if any, are generally incorporated into the rubber composition in quantities ranging from about 1 to about 80 parts per annum and preferably from about 5 to about 60 parts per annum. Charge-elastomer coupling agent:

[0145] The composition according to the invention optionally comprises a filler-elastomer coupling agent, which allows the filler to be covalently bound to the elastomer. The coupling agent acts as a connecting bridge between the filler and the elastomer, thus improving the reinforcing effect of the rubber by the reinforcing filler. The coupling agent is different from the alkoxylated nitrogen compound of general formula (I).

[0146] Silanes, and more preferably polysulfide silanes, are preferred as coupling agents. Silanes are particularly used when the reinforcing filler consists mainly of an inorganic filler, especially silica.

[0147] Examples of polysulfide silanes include: - polysulfides (particularly disulfides, trisulfides, or tetrasulfides) of bis-(alkoxyl(Ci-C4)-alkyl(Ci-C4)silyl-(Ci-C4)alkyl), such as bis(3-trimethoxysilylpropyl) or bis(3-triethoxysilylpropyl) polysulfides. Among these compounds, bis(3-triethoxysilylpropyl) tetrasulfide, abbreviated TESPT, with the formula [(C2H5O)3Si(CH2)3S2]2, and bis-(triethoxysilylpropyl) disulfide, abbreviated TESPD, with the formula [(C2H5O)3Si(CH2)3S]2, are particularly used; and - the polysulfides (in particular disulfides, trisulfides or tetrasulfides) of bis- (monoalkoxyl(Ci-C4)-dialkyl(Ci-C4)silylpropyl), more particularly the tetrasulfide of bis-monoethoxydimethylsilylpropyl as described in patent application WO 02 / 083782.

[0148] Coupling agents may also be cited as: - bifunctional POS (polyorganosiloxanes) or hydroxysilane polysulfides as described in patent application WO 02 / 030939, or - silanes or POS bearing azo-dicarbonyl functional groups, as described for example in patent applications WO 2006 / 125532, WO 2006 / 125533 and WO 2006 / 125534, or - silanes bearing thioester groups, mercapto-blocked such as S-(3-(triethoxysilyl)propyl)octanethioate, or - silanes as described in document WO 2005 / 40264.

[0149] Preferably, the coupling agent is chosen from among the following polysulfide silanes: - 3-mercaptopropyltrimethoxysilane; - bis-(3-triethoxysilylpropyl)tetrasulfide; - bis-(3-triethoxysilylpropyl)disulfide; - 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide; - trimethoxysilylpropylmercaptobenzothiazoltetrasulfide; - triethoxysilylpropyl methacrylate monosulfide; and - dimethoxymethylsilylpropyl-N,N-dimethyl-thiocarbamoyltetrasulfide.

[0150] For example, it is possible to use the following commercial silanes, marketed by Evonik: Si 69® (Bis(triethoxysilylpropyl)tetrasulfide), Si 75® and Si 266® (Bis(triethoxysilylpropyl)disulfide).

[0151] In particular, the quantity of the coupling agent is between 0.5 and 20 pc, preferably between 3 and 15 pc, preferably between 4 and 9 pc. Crosslinking system:

[0152] The crosslinking system is in particular a vulcanization system. It may comprise various compounds that will enable the crosslinking / vulcanization of the rubber. It includes in particular one or more vulcanization accelerator(s), preferably sulfur-containing. In particular, the vulcanization accelerator(s) used in said crosslinking system is / are different from the alkoxylated nitrogen compound(s) of formula (I) according to the invention.

[0153] For example, the crosslinking system may include a sulfur donor, such as elemental sulfur, and at least one sulfur-containing vulcanization accelerator. In particular, the crosslinking system includes a sulfur donor, such as elemental sulfur, at least one sulfur-containing primary vulcanization accelerator, and / or at least one sulfur-containing secondary vulcanization accelerator, such as thiuram. Preferably, the crosslinking system includes thiuram.

[0154] In particular, the sulfur donor is used in an amount between 0.5 and 10 pc, more preferably between 0.5 and 5.0 pc, for example between 0.5 and 3.5 pc.

[0155] The vulcanization accelerators may be in a quantity, for each of them, of between 0.05 and 20 pc, preferably between 0.1 and 5 pc, and even more preferably between 0.15 and 3 pc.

[0156] Various known vulcanization activators such as metal oxides like zinc oxide (preferably 0.5 to 10 pc), stearic acid or others (preferably 0.5 to 5 pc each) may also be added.

[0157] Any compound capable of acting as a vulcanization accelerator can be used as a sulfur vulcanization accelerator, particularly in the presence of a sulfur donor such as elemental sulfur.

[0158] Preferably, said sulfur vulcanizing accelerator is selected from the group consisting of thiazoles, sulfenamides, thiurams, dithiocarbamates, dithiophosphates, xanthates, dithiodiamines, thioureas, poly(phenol sulfides), their derivatives and mixtures. More particularly, a sulfenamide (such as CBS, DCBS, TBBS or TBSI), a thiazole (such as MBTS or MBT), a thiuram (such as TBzTD), a dithiocarbamate (such as ZBEC) or mixtures thereof may be used as a sulfur vulcanizing accelerator.

[0159] An accelerator chosen from the group consisting of ZBEC, CBS, DCBS, TBBS, TBSI, MBTS, MBT, TBzTD and their mixtures is preferred. CBS, TBBS and their mixtures are particularly preferred as a sulfur-based vulcanization accelerator, and more preferably as a primary vulcanization accelerator.

[0160] Thiurams and in particular TBzTD are particularly preferred as a sulfur vulcanization accelerator, and more preferably as a secondary vulcanization accelerator.

[0161] Among the thiazoles, we can mention 2-mercaptobenzothiazole (called MBT, CAS No. 149-30-4), 2,2'-dithiobis(benzothiazole) (called MBTS, CAS No. 120-78-5) and their mixtures.

[0162] Among the sulfenamides, we can mention N-Cyclohexyl-2-benzothiazole sulfenamide (called CBS, CAS No. 95-33-0), N-tert-Butyl-2-benzothiazole sulfenamide (called TBBS, CAS No. 95-31-8), N-Benzothiazol-2-ylsulfanyl-N-tert-butyl-benzothiazole-2-sulfenamide (called TBSI, CAS No. 3741-80-8), N,N-dicyclohexylbenzothiazole-2-sulfenamide (called DCBS, CAS No. 4979-32-2) and their mixtures.

[0163] Thiurams are in particular selected from among thiuram sulfides, disulfides and polysulfides.

[0164] The thiurame can be chosen from the group consisting of: - tetramethylthiuram sulfide (TMTM, CAS No. 97-74-5), - tetrabenzylthiuram disulfide (TBzTD, CAS No.: 10591-85-2), - tetramethylthiuram disulfide (TMTD, CAS No.: 97-74-5), - tetraethylthiuram disulfide (TETD, CAS No.: 97-77-8), - tetrabutylthiuram disulfide (TBTD, CAS No.: 1634-02-2), - tetrakis(2-ethylhexyl)thiuram disulfide (TOTD, CAS No.: 37437-21-1), - tetraisobutylthiuram disulfide (TiBTD, CAS No.: 3064-73-1), - dimethyldiphenyl thiurame disulfide (TMPTD, CAS No. 10591-84-1), - dipentamethylenethiuram hexasulfide (DPTT, CAS No. 971-15-3) and their mixtures.

[0165] In particular, thiurame disulfide is chosen from the group consisting of: - tetrabenzylthiuram disulfide (TBzTD), - tetrakis(2-ethylhexyl)thiuram disulfide (TOTD), - tetraisobutylthiuram disulfide (TiBTD), and mixtures thereof.

[0166] Preferably, the thiuram disulfide is tetrabenzylthiuram disulfide (TBzTD), of the following formula:

[0167] Among the dithiocarbamates, dithiocarbamate salts of zinc, copper, or sodium are of particular concern. Examples include: - zinc dibenzyldithiocarbamate (ZBEC, CAS No. 14726-36-4), - zinc diethyldithiocarbamate (ZDEC, CAS No. 14324-55-1), - zinc dibutyldithiocarbamate (ZDBC, CAS no. 136-23-2), - copper dibutyldithiocarbamate (CDBC, CAS No. 13927-71-4), - sodium dibenzyldithiocarbamate (NaBEC, CAS No. 55310-46-8) and their mixtures.

[0168] Dithiophosphates are in particular selected from di- and polysulfides of dithiophosphates and their salts, such as their zinc salts. Among the dithiophosphates, the following are included: - phosphorodithioic acid, mixed esters 0,0-bis (2-ethylhexyl and iso-Bu), zinc salts (ZDTP, CAS No. 68442-22-8), - phosphorodithioic acid, mixed esters 0,0-bis (2-ethylhexyl, iso-Bu and iso-Pr), zinc salts (CAS No. 85940-28-9), - isodecyl zinc phosphorodithioate (CAS No. 25103-54-2) and mixtures thereof.

[0169] Xanthates are in particular selected from (Ci-C20) alkyl esters of xanthate and (C1-C20) alkyl ester di- or polysulfides of xanthogen, or their metal salts (for example, their alkaline earth or zinc salts). Xanthates may be selected from the group consisting of zinc isopropyl xanthate (ZIX), sodium isopropyl xanthate (SIX), zinc butyl xanthate (ZBX), dibutyl xanthogen disulfide, diisopropyl xanthogen disulfide, diisobutyl xanthogen disulfide and mixtures thereof.

[0170] Dithiodiamines include in particular dithiodimorpholine (DTDM, CAS No. 103-34-4) and caprolactam disulfide (CLD, CAS No. 23847-08-7).

[0171] Most of these products are marketed by Arkema under the EKALAND™ and Mixland+® brands. Examples include: MIXLAND+® S, MIXLAND+® CBS, MIXLAND+® TBBS, MIXLAND+® MBT, MIXLAND+® MBTS, EKALAND™ TBzTD, MIXLAND+® TBzTD, EKALAND™ ZBEC C, MIXLAND+® ZBEC, MIXLAND+® ZDTP, MIXLAND+® ZnO, and MIXLAND+® DTDM. Preferably, MIXLAND+® S, MIXLAND+® CBS, MIXLAND+® TBBS, EKALAND™ TBzTD, MIXLAND+® TBzTD, and MIXLAND+® ZnO may be used.

[0172] Poly(phenol sulfide) means, in particular, oligomers or polymers as described in application WO 2015 / 001234. Poly(phenol sulfides) are marketed in particular by Arkema under the generic name Vultac®, among which are Vultac® 2, Vultac® 3, Vultac® 5, Vultac® TB7, Vultac® 710 and Vultac® TB710, MIXLAND +® TBP 75.

[0173] The rubber composition according to the invention may also include one or more other additives such as:

[0174] - crosslinking retardants, making it possible to increase in particular the time of scorch time, or "scorch time" such as MIXLAND +® CTPI (CAS No. 17796-82-6);

[0175] - compounds for improving resistance to reversal of the composition thanks to their ability to reform crosslinking bridges in use (such as PERKALINK 900 or HTS or VULCUREN);

[0176] - antioxidants;

[0177] - antiozonants;

[0178] - anti-fatigue additives;

[0179] - plasticizers such as oils or waxes;

[0180] - fillers other than silica and carbon black such as organic fillers allowing for a lighter composition;

[0181] - reinforcing pigments; and

[0182] - reinforcing and / or plasticizing and / or tackifying resins.

[0183] Method for vulcanizing the rubber composition according to the invention

[0184] The present invention also relates to a method for vulcanizing a rubber composition such as that according to the invention, comprising the following steps:

[0185] 1) a coupling step comprising the mixing of:

[0186] (a) at least one elastomer, preferably at least one diene elastomer, such as as defined above,

[0187] (b) a reinforcing load as defined above,

[0188] (c) optionally a charge-elastomer coupling agent as defined above, And

[0189] (f) possibly other additives;

[0190] 2) an acceleration step comprising the addition of a crosslinking system (e) such as defined above to the mixture obtained at the end of step 1); and

[0191] 3) a vulcanization step of the mixture obtained at the end of step 2), in order to to obtain a vulcanized rubber composition;

[0192] wherein at least one alkoxylated nitrogen compound of general formula (I) as defined above is added during step 1) and / or during step 2), preferably during step 1).

[0193] The three steps of coupling, acceleration and vulcanization are known to those skilled in the art and can be carried out under conventional conditions. Steps 1) and 2) are generally carried out in an internal or roller mixer, preferably agitated.

[0194] 1) Coupling step

[0195] The coupling step allows the reinforcing filler to be coupled to the elastomer. A coupling agent may be required for this purpose. Preferably, the coupling agent used is a silane: in this case, the coupling step is called the silanization step.

[0196] The elastomer, the reinforcing filler, optionally the coupling agent, optionally the alkoxylated nitrogen compound(s), and optionally other additives can be mixed in this way. The temperature can be increased to between 100 and 180 °C, preferably between 120 and 165 °C (this temperature increase is called a "pass"). This temperature increase can be achieved through self-heating generated by the mixing of the constituents added at this stage, or by heating the mixer, or both. The mixture can then be left to cool. According to one embodiment, the reinforcing filler can be added to the mixture in two passes, each from 100 to 180 °C, preferably from 120 to 165 °C. The resulting cooled mixture is then said to be "coupled" (or "silanized" if a silane is used).

[0197] 2) Acceleration stage

[0198] The acceleration step includes adding the crosslinking system to the coupled mixture. This addition can be carried out at a temperature between 20 and 140 °C, preferably between 30 and 100 °C. At the end of this acceleration step, a so-called "raw" rubber is obtained. It must then be shaped and vulcanized.

[0199] 3) Shaping / vulcanization step

[0200] During this step, the rubber compound can be shaped by means known to those skilled in the art, and then transferred into a final shaping element, such as a mold, which is heated to a temperature between 100 and 200°C, preferably between 140 and 180°C. This step can last between 5 and 90 minutes. At the end of this step, a "cured" rubber is obtained, which can be used to manufacture various articles, such as tires.

[0201] The examples below are given for illustrative purposes only and are not limiting to the present invention. EXAMPLES

[0202] A-Preparation and vulcanization protocol for rubber compositions

[0203] The following preparation protocol is carried out in a HAAKE™ PolyLab™ QC mixer. A1) Coupling step:

[0204] 1st pass:

[0205] The mixer is heated to 100°C and the agitation is increased to 60 rpm.

[0206] The SSBR (Solution-Styrene Butadiene Rubber) and BR (Butadiene Rubber) elastomers are introduced. Then, the mixture is prepared for 1 min.

[0207] Half of the total planned quantity of silica, silane, ZnO, stearic acid and DPG (comparative) or an alkoxylated nitrogen compound according to the invention is added, and then mixed for 2 min.

[0208] Next, the other half of the silica, the antioxidant, the wax and a manufacturing aid are added. Then, the mixture is stirred for 1 min.

[0209] The mixer piston is raised and cleaned for 1 min, then the piston is lowered.

[0210] The temperature of the mixer is increased up to 160°C. When 160°C is reached, the stirring is stopped.

[0211] The mixture is left to stand for cooling for 45 min.

[0212] 2nd pass:

[0213] The mixer is heated to 100°C and the agitation is increased to 60 rpm.

[0214] Then, the cooled mixture obtained at the end of the first pass is introduced, after having previously cut it.

[0215] Mix for 2 min. Then, increase the mixer temperature to 160°C. When 160°C is reached, stop stirring.

[0216] The mixture is left to stand for cooling for 45 min. A-2) Acceleration stage:

[0217] The mixer is heated to 50°C and the agitation is increased to 30 rpm.

[0218] The cooled mixture obtained at the end of the coupling step is introduced, after having been cut.

[0219] Mix for 2 min.

[0220] Next, the accelerators are added: sulfur, sulfenamide and possibly thiuram.

[0221] Mix for 2 min, then stop stirring.

[0222] Samples of this raw rubber are taken in order to carry out rheometry tests. A-3) Shaping / vulcanization stage:

[0223] The mixture is passed over an external mixer (cylinders) to form a plate.

[0224] The mixture is placed in a vulcanizing press. It is vulcanized at 160 °C for a time corresponding to t90 (in minutes), determined by rheometric analysis: a cooked rubber is obtained.

[0225] B-Protocols for the analysis of rubber compositions Bl) Rheometry:

[0226] These tests are carried out on the "raw" rubber pieces obtained according to the preceding steps A1 and A2. They are performed using an MDR Pioneer rheometer. according to the standard: NF ISO 6502-2:2018 "Rubber - Measurement of vulcanization characteristics using rheometers - Part 2: Oscillating disc rheometer".

[0227] In particular, we determine:

[0228] Ts2 (min):

[0229] Time required for the rubber to begin to vulcanize (time from which the vulcanizing torque reaches a value slightly above that of the minimum torque - usually 2 units above).

[0230] The values ​​are given as a base of 100 relative to the reference. A Ts2 value equal to or greater than 100 indicates a pre-vulcanization time equal to or greater than the reference. This is preferable to ensure a safe time before the start of vulcanization.

[0231] t90 (min) (or cooking time at 90%):

[0232] Time required to achieve 90% of complete vulcanization of the rubber.

[0233] The values ​​are given as a base of 100 relative to the reference. A t90 value equal to or less than 100 indicates a vulcanization time equal to or shorter than the reference.

[0234] Delta C (dN.m):

[0235] Parameter used to measure the increase in vulcanization torque. More precisely, it represents the difference between the maximum torque reached during vulcanization and the initial minimum torque. It indicates the extent of rubber cross-linking.

[0236] A high Delta C means that the rubber has undergone significant vulcanization, which generally results in better mechanical properties, such as increased strength.

[0237] The values ​​are given as a base of 100 relative to the reference. A Delta C value of 100 or close to 100 indicates a crosslinking density similar to the reference. B-2) Viscometer analysis:

[0238] Toasting time Ts5 (min) ("scorch time"):

[0239] It is determined on a Monsanto Mooney MV 2000 apparatus on raw rubber parts according to standard NF ISO 289-2: 2020 "Unvulcanized rubber - Determinations using a shear disc consistometer - Part 2: Determination of prevulcanization characteristics".

[0240] Values ​​are given as a base of 100 relative to the reference. A Ts5 value of 100 or higher indicates a roasting time equal to or greater than the reference. This roasting time determines the pre-laccanization characteristics corresponding to the time during which a rubber compound can be maintained at high temperatures while retaining its suitability for implementation (before the start of vulcanization).

[0241] The viscometer also allows the determination of the viscosity of a raw rubber, or of a masterbatch according to the standard NF ISO 289-1: 2015, "Unvulcanized rubber - Determinations using a shear disc consistometer - Part 1: Determination of the Mooney consistometric index".

[0242] This analysis makes it possible to determine the final viscosity of a mixture at 80 °C, for example. It is denoted ML(l+4). This corresponds to the viscosity after 1 min of preheating the mixture, then 4 min of measurement. B-3) Analysis on a tensile test bench:

[0243] The analyses are carried out on a HOUNSFIELD H5KS apparatus using rubber parts vulcanized according to step A-3 above.

[0244] Five test specimens of vulcanized rubber, without defects, are cut in the calendering direction,

[0245] according to ISO 23529:2016 “Rubber — General procedures for the preparation and conditioning of test specimens for physical test methods”.

[0246] Tensile measurements are carried out according to ISO 37:2024 "Vulcanized or thermoplastic rubber - Determination of tensile stress-strain characteristics".

[0247] This measurement allows access to the mechanical properties of the rubber such as the M300 / M100 ratio characterizing the load ratio related to the rubber.

[0248] M300 / M100:

[0249] M100 represents the modulus (MPa) at 100% elongation, i.e. the stress required to stretch the rubber to 100% of its initial length. M300 represents the modulus (MPa) at 300% elongation, that is, the stress required to stretch the rubber to 300% of its initial length.

[0250] The values ​​are expressed as a base of 100 relative to the reference. An M300 / M100 value equal to or greater than 100 therefore indicates a load factor equal to or greater than the reference.

[0251] Tensile strength (MPa):

[0252] This value characterizes the force that must be applied to the rubber sample for it to break. Values ​​are expressed as a base of 100 relative to the reference. A tensile strength value equal to or greater than 100 indicates improved mechanical properties. B-4) DMA Analysis (Dynamic Mechanical Analysis)

[0253] The DMA analysis is carried out on a Mettler Toledo DMA1 apparatus following the standard "ISO 4664-1: 2022 Vulcanized or thermoplastic rubber — Determination of dynamic properties" on a small test apparatus.

[0254] The vulcanized rubber sample is clamped between two jaws and pre-tensioned to 1%. It is then subjected to tensile stress following an oscillatory deformation of "± A" pm in frequency and over a temperature range. "A" must correspond to the linearity zone of the sample.

[0255] We thus obtain the values ​​of conservation modulus (=elastic modulus E'), loss modulus E” (viscous modulus) and the damping factor tan ô = E” / E' as a function of temperature.

[0256] The tests are carried out in tension, the distance between supports holding the rubber part is equal to 20mm, the width 2mm and the thickness 2mm.

[0257] The temperature sweep tests are carried out under the following conditions:

[0258] - Tensile test with a pre-deformation of 1%,

[0259] - Oscillation of amplitude A = 20 pm around the pre-tension position,

[0260] - Oscillation frequency: 10Hz,

[0261] - Conditioning: 30 min at 80°C,

[0262] - Temperature range: -80°C to +120°C

[0263] - Temperature rise rate IK / min.

[0264] tan ô(40°C):

[0265] The value tan ô(40°C) corresponds to an indication of the rolling resistance phenomenon in the case where the rubber part is used to constitute the tread of a tire.

[0266] The results are expressed on a base of 100. That is to say, a value identical to, close to, or lower than the reference indicates an identical, close to, or lower rolling resistance. An identical or reduced rolling resistance is desirable for higher-performance tires. C-Tests of rubber compositions Test Cl:

[0267] Two compositions are prepared according to steps A1) and A-2) mentioned above (coupling and acceleration).

[0268] The first composition includes DPG, the second includes Noramox® S2 marketed by the company Arkema.

[0269] Noramox® S2 (CAS No.: 1218787-32-6) is a mixture of ethanol, 2,2'-iminobis-, N-(Ci6-Ci8)alkyl and unsaturated Ci8alkyl derivatives. It corresponds to a mixture of alkoxylated nitrogen compounds according to the invention. 1.1 Preparation of rubber compositions

[0270] The ingredients of the two rubber compositions are as follows:

[0271] [Tables2] Rubber Composition DPG Composition (comparative) Noramox® S2 Composition (invention) SSBR Buna VSL 2438-2 HM (contains 27.3% wt. of T DAE oil) 96 96 BR KUMHO KBR 01 30 30 Silica ULTRASIL® VN 3 GR 80 80 Silane EUVOMAXX® TESPT Bis-[3-(triethoxysilyl)-propyl]-tetrasulfone 6.5 6.5 DPG EKALAND™ DPG 2 NORAMOX® S2 2 Manufacturing Adjuvant STRUKTOE® A60 2 2 ZnO 3 3 Stearic Acid 2 2 Polyethylene Wax 2 2 Antioxidant 6PPD 2 2 CBS MIXEAND +® CBS 80 GA 1.88 1.88 TBzTD EKALAND™ TBzTD 0.25 Sulfur MIXEAND +® Sulfur 80 GA 1.88 1.88

[0272] Quantities are in pieces. 1.2 Properties of the raw rubbers obtained

[0273] The rheometric properties of the rubbers obtained are determined using an MDR Pioneer rheometer.

[0274] The results are as follows:

[0275] [Tables3] Rheometric results DPG Noramox® S2 Delta C 100 95 t90 100 82 ts2 100 177 ts5 100 100

[0276] The alkoxylated nitrogen compounds according to the invention make it possible to obtain a Delta C and a ts5 similar to those obtained with DPG.

[0277] Furthermore, the alkoxylated nitrogen compounds according to the invention allow for better t90 and ts2 values. Indeed, the t90 is lower than that obtained with DPG: vulcanization is faster. The ts2 is higher: the safe handling time for the rubber before curing is longer.

[0278] The alkoxylated nitrogen compounds according to the invention therefore make it possible to improve the rheometric properties of raw rubbers compared to DPG.

[0279] Test C-2: Decrease in the amount of alkoxylated nitrogen compound

[0280] The same preparation and vulcanization protocol as Test Cl is followed, at with the exception of the quantity of Noramox® S2 used, which is reduced from 2 to 1 pc. 2.1 Properties of the raw rubbers obtained

[0281] The rheometric properties of the raw rubbers obtained are determined using an MDR Pioneer rheometer and the roasting time using a Monsanto Mooney MV 2000 viscometer.

[0282] The results are as follows:

[0283] [Tables4] Results on raw DPG rubbers: 2 pcs Noramox S2, 2 pcs Noramox S2, 1 pc Delta C: 100, 95, 98, t90, 100, 82, 98, ts2, 100, 177, 130, ts5 (Roasting time 125 °C), 100, 100, 108

[0284] The alkoxylated nitrogen compounds according to the invention make it possible to obtain a Delta C, a t90 and a roasting time similar to those obtained with DPG, even with a smaller quantity.

[0285] The ts2 remains even improved, with half the additive.

[0286] Test C-3: Properties of the cured rubbers obtained

[0287] The tested rubbers are vulcanized according to step A-3) and their mechanical properties are determined.

[0288] A HOUNSFIELD H5KS tensile testing machine is used for tensile testing.

[0289] The Tan (delta 40°C) is determined using a Mettler Toledo DMA1 dynamic mechanical analyzer.

[0290] The results are as follows:

[0291] [Tables5] Results on DPG vulcanized rubbers 2 pc Noramox S2 2 pc Noramox S2 1 pc Tensile strength 100 103 100 M300 / M100 100 100 97 Tan(delta 40°C)f= 10 Hz 100 98 103

[0292] It is noted that the breaking strength and the M300 / M100 ratio are similar to those obtained with the DPG, even at 1 pc.

[0293] Tan(delta 40°C ) represents rolling resistance: here too, the performance of alkoxylated nitrogen compounds according to the invention is similar to that obtained with DPG, even at 1 pc.

[0294] D. Process for preparing the alkoxylated nitrogen compound in the form of a master mixture

[0295] Dl- Preparation of the masterbatch on POE / silica support

[0296] A masterbatch is prepared based on Noramox® S2 marketed by the company Arkema.

[0297] In the HAAKE mixer, the following conditions are observed: - Filling coefficient: 0.6 to 0.95, preferably 0.80; - Initial mixer temperature: 20-80°C, preferably 40°C.

[0298] Thus, the mixing chamber is heated to 40 °C and the rotors are rotated at 40 revolutions per minute.

[0299] 12g of poly(Ethylene-l-Butene) (CAS No. 25087-34-7) are introduced into the mixing chamber as well as 18 g of silica (Ultrasil 7000) and 20 g of Noramox® S2.

[0300] The rotor speed is increased to 60 revolutions per minute.

[0301] The mixing torque increases until it reaches a maximum. Once the maximum is reached, mixing is continued for 3 minutes. Then the rotors are stopped and the white master mixture is recovered by draining the mixing chamber.

[0302] The mixture is then analyzed using a Mooney viscometer: Final viscosity at 80 °C = ML(l+4) = 9 MU

[0303] D.2- Preparation of the masterbatch on SBR / silica support

[0304] A masterbatch is prepared based on Noramox® S2 marketed by the company Arkema.

[0305] In the HAAKE mixer, the following conditions are followed: - Filling coefficient: 0.6 to 0.95, preferably 0.80; - Initial mixer temperature: 20-80°C, preferably 40°C.

[0306] Thus, the mixing chamber is heated to 40 °C and the rotors are rotated at 40 revolutions per minute.

[0307] 7.4g of ESBR KUMHO 1502 (styrene butadiene copolymer emulsion) are introduced into the mixing chamber along with 19.6g of silica (Ultrasil 7000) and 22.1g of Noramox® S2.

[0308] The speed of the rotors is increased to 60 revolutions per minute.

[0309] The mixing torque increases until it reaches a maximum. Once the maximum is reached, mixing is continued for 3 minutes. Then the rotors are stopped and the white master mixture is recovered by draining the mixing chamber.

[0310] The mixture is then analyzed using a Mooney viscometer:

[0311] Final viscosity at 80 °C ML(l+4) = 9.3 MU

[0312] D.3- Test of the Noramox® S2 / POE / Silica masterbatch

[0313] The master mixture obtained in Dl was used to prepare a rubber composition according to steps A1) and A-2) of protocol A above.

[0314] This master mix contains 40% active ingredient (Noramox® S2): 1 / 0.4 = 2.5 pc of master mix is ​​required to be at the same pc in active ingredient, compared to unformulated Noramox® S2.

[0315] The rheometric properties of the raw rubbers obtained are determined using an MDR rheometer.

[0316] It is observed that adding the alkoxylated nitrogen compounds according to the invention in the form of a masterbatch allows for the preservation of properties similar to those of the unformulated alkoxylated nitrogen compounds. An improved ts2 is even maintained compared to the DPG.

Claims

Demands

1. Rubber composition comprising: (a) at least one elastomer, preferably at least one diene elastomer, (b) a reinforcing load, (c) possibly a charge-elastomer coupling agent, (d) at least one alkoxylated nitrogen compound of the following general formula (I), or one of its salts: in which: - m is an integer greater than or equal to 1, preferably between 1 and 20; - n is an integer greater than or equal to 1, preferably between 1 and 20; - A is a linear or branched (C2-Ci0)alkylene group, possibly substituted by one or more (C1-C24)alkyl or (C6-Ci0)aryl group(s); - X is either a -CH2- group or a -C(=O)- group; and - R is a linear or branched (C6-C3o)alkyl group, which may contain one or more unsaturations; and (e) a crosslinking system; said composition comprising less than 0.5 pc of guanidine compound.

2. Rubber composition according to claim 1, wherein said at least one alkoxylated nitrogen compound has the following general formula (IA), or one of its salts: (IA), ï HO in which: - X is either a -CH2- group or a -C(=O)- group; and - R is a linear or branched (C6-C30)alkyl group, which may contain one or more unsaturations.

3. Rubber composition according to claim 1 or 2, wherein the total amount of the alkoxylated nitrogen compound(s) is between 0.10 and 10 pc, preferably between 0.10 and 5 pc.

4. Rubber composition according to any one of the preceding claims, said composition not comprising a guanidic compound.

5. Rubber composition according to any one of the preceding claims, wherein the elastomer(s) is / are selected from the group consisting of polyisoprenes, NR (natural rubbers), SBR (styrene-butadiene rubbers) such as SSBR (Solution-Styrene-Butadiene Rubber) and ESBR (Emulsion-Styrene-Butadiene Rubber), EPDM (ethylene-propylene-diene monomer terpolymer), BR (butadiene rubbers), POEs (polyolefin elastomers) and mixtures thereof such as SBR / BR and even more preferably SSBR / BR.

6. Rubber composition according to any one of the preceding claims, wherein the reinforcing filler comprises predominantly silica.

7. Rubber composition according to any one of the preceding claims, wherein the crosslinking system comprises a sulfur donor, such as elemental sulfur, and at least one sulfur vulcanization accelerator.

8. Rubber composition according to claim 7, wherein said sulfur vulcanization accelerator is selected from the group consisting of thiazoles, sulfenamides, thiurams, dithiocarbamates, dithiophosphates, xanthates, dithiodiamines, thioureas, poly(phenol sulfides), their derivatives and mixtures thereof, preferably from thiurams.

9. Rubber composition according to any one of the preceding claims, wherein the alkoxylated nitrogen compound(s) is in the form of a masterbatch.

10. A method for vulcanizing a rubber composition such as according to any one of claims 1 to 9, comprising the following steps: (l) a coupling step comprising the mixing of: (a) at least one elastomer, preferably at least one diene elastomer, (b) a reinforcing load, (c) possibly a charge-elastomer coupling agent, and (f) possibly other additives; 2) an acceleration step comprising the addition of the crosslinking system € to the mixture obtained at the end of step 1); and 3) a vulcanization step of the mixture obtained at the end of step 2), in order to obtain a vulcanized rubber composition; wherein at least one alkoxylated nitrogen compound of general formula (I) as defined in any one of claims 1 or 2 is added during step 1) and / or during step 2).

11. Article, preferably a tire, comprising a rubber composition as defined in any one of claims 1 to 9 vulcanized.

12. Use of an alkoxylated nitrogen compound of the following general formula (I), or one of its salts: in which: - m is an integer greater than or equal to 1, preferably between 1 and 20; - n is an integer greater than or equal to 1, preferably between 1 and 20; - A is a linear or branched (C2-Ci0)alkylene group, possibly substituted by one or more (C1-C24) alkyl or (C6-Ci0)aryl group(s); - X is either a -CH2- group or a -C(=O)- group; and - R is a linear or branched (C6-C30)alkyl group, which may contain one or more unsaturations; as a replacement for a guanidine compound.