Masterbatch made from modified polymers and organophosphorus additives and its preparation method

Abstract

This invention relates to a method for preparing a masterbatch, comprising the steps of: (a) contacting at least one initial polymer comprising at least one carbon-carbon unsaturated bond with at least one 1,3-dipolar grafting agent having at least one nitrile oxide dipole and at least one N-substituted or unsubstituted imidazolinone functional group in the presence of at least one organophosphorus additive, said organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides, and mixtures thereof; and (b) recovering the masterbatch obtained in the previous step. The invention also relates to masterbatches, compositions comprising masterbatches, and tires comprising said compositions.

Description

Technical Field

[0001] The field of this invention is based on polymer masterbatches, their preparation methods and their use in compositions, particularly in rubber compositions, especially for the manufacture of pneumatic or non-pneumatic tires. Background Technology

[0002] In the industrial sector of objects made from rubber compositions (such as pneumatic or non-pneumatic tires), mixtures of polymers and reinforcing fillers are frequently used.

[0003] In order for this composition to exhibit good performance, methods to improve the dispersion of reinforcing fillers in these polymers are constantly being sought.

[0004] This is because when these rubber compositions are used in pneumatic or non-pneumatic tires, the good dispersion of these fillers in these polymers generally means low hysteresis and thus improved rolling resistance.

[0005] However, improving rolling resistance remains an ongoing challenge for manufacturers of these objects, especially as fuel conservation and environmental protection have become priorities.

[0006] Many solutions have been proposed to reduce lag.

[0007] Particularly noteworthy is the modification of the structure of polymers (especially diene elastomers) using grafting agents, with the aim of achieving a favorable interaction between the thereby modified polymer and the reinforcing filler (whether carbon black or inorganic reinforcing filler such as silica). For example, reference EP 0 778 311 B1 describes the use of diene polymers functionalized with silanol groups at the chain ends. More recently, patent application WO 2009 / 077837 A1 describes an elastomer functionalized with silanol groups at one chain end and amino groups at the other.

[0008] The use of 1,3-dipolar grafting agents with at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group may also be mentioned. Modification of polymers by this type of compound is known, and proceeds via a [3+2] cycloaddition reaction of the grafting agent with the carbon-carbon unsaturated bonds of the polymer monomer. Rubber compositions comprising polymers modified with said grafting agents, as described in documents WO 2012 / 007442 A1, WO 2019 / 007883 A1, and FR 19 / 09030, have demonstrated advantageous properties in terms of hysteresis.

[0009] Nevertheless, rubber compositions with improved hysteresis are still needed.

[0010] Upon further investigation, the applicant discovered a novel method for preparing a masterbatch comprising an organophosphorus additive and a polymer modified by a 1,3-dipolar grafting agent in the presence of the additive; the resulting masterbatch for use in rubber compositions imparts improved hysteresis properties to the rubber compositions. Summary of the Invention

[0011] Therefore, one subject of the present invention is at least one method for preparing a masterbatch, comprising the following steps:

[0012] (a) In the presence of at least one organophosphorus additive, at least one initial polymer comprising at least one carbon-carbon unsaturated bond is contacted with at least one 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group, said organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides and mixtures thereof.

[0013] (b) Recycle the masterbatch obtained in the previous step.

[0014] More particularly, the method for preparing masterbatch according to the invention can advantageously exhibit at least one of the following preferred features individually or in combination.

[0015] Preferably, the organophosphorus additives are contacted with the initial polymer, and then they are contacted with the 1,3-dipolar grafting agent.

[0016] Preferably, the organophosphorus additives are contacted with a 1,3-dipolar grafting agent before being contacted with the initial polymer.

[0017] Preferably, the initial polymer, the 1,3-dipolar grafting agent, and the organophosphorus additive are contacted simultaneously.

[0018] Preferably, the contact step (a) is carried out in the bulk or in a solution.

[0019] Preferably, steps (a) and (b) are performed at a temperature of 35°C or lower.

[0020] Preferably, after the contact step (a), the method further includes at least one heat treatment step (a').

[0021] Preferably, the heat treatment step (a') is carried out at a temperature above 35°C, more preferably at a temperature above or equal to 36°C, even more preferably at a temperature in the range of 36°C to 180°C, and even more preferably at a temperature in the range of 36°C to 150°C.

[0022] Preferably, the organophosphorus additive is selected from triphosphates, phosphonates, hypophosphonates, and mixtures of these compounds.

[0023] Preferably, the organophosphorus additive is selected from triphosphates, phosphonates, and mixtures of these compounds.

[0024] Preferably, the organophosphorus additive is selected from triphosphates and mixtures of these compounds.

[0025] Preferably, the organophosphorus additive corresponds to formula (I):

[0026]

[0027] in:

[0028] -R1 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0029] -R2 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, and (C6-C20)aryl(C1-C20)alkyl; and

[0030] -R3 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0031] Preferably, the organophosphorus additive corresponds to formula (I), wherein:

[0032] -R1 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups;

[0033] -R2 is selected from C1-C20 alkyl, C6-C20 aryl, and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups; and

[0034] -R3 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, where Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups.

[0035] Preferably, the organophosphorus additive corresponds to formula (Ia):

[0036]

[0037] R1a, R2a, and R3a may be the same or different and are selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, and (C6-C20)aryl(C1-C20)alkyl.

[0038] Preferably, in formula (Ia), R1a, R2a, and R3a may be the same or different and are selected from C1-C12 alkyl, C6-C12 aryl, (C1-C12)alkyl(C6-C12)aryl, and (C6-C12)aryl(C1-C12)alkyl.

[0039] Preferably, in formula (Ia), R1a, R2a, and R3a may be the same or different, and are selected from C1-C12 alkyl and C6-C12 aryl.

[0040] Preferably, the organophosphorus additive is selected from tri(ethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, tri-n-octyl phosphate, triisobutyl phosphate, and mixtures thereof.

[0041] Preferably, the initial polymer is an elastomer containing at least one carbon-carbon unsaturated bond.

[0042] Preferably, the initial polymer is a diene elastomer.

[0043] Preferably, the initial polymer is selected from natural rubber, synthetic polyisoprene, polybutadiene, isoprene copolymers, butadiene copolymers, and mixtures of these polymers.

[0044] Preferably, the initial polymer is selected from natural rubber, synthetic polyisoprene, isoprene copolymers, and mixtures of these polymers.

[0045] Preferably, the molar content of the 1,3-dipolar grafting agent is in the range of 0.01 mol% to 10 mol%, more preferably in the range of 0.01 mol% to 5 mol%.

[0046] Preferably, the organophosphorus additive is used at a concentration of 0.3 php (French abbreviation "pcp"); more preferably, at a concentration of 0.4 php; and even more preferably, at a concentration of 0.5 php.

[0047] Preferably, the organophosphorus additive is used in a concentration ranging from 0.3 php to 20 php, more preferably from 0.4 php to 10 php.

[0048] Preferably, the 1,3-dipolar grafting agent corresponds to formula (II):

[0049]

[0050] in:

[0051] -A represents a C6-C14 aryl ring, which is optionally substituted by one or more identical or different, preferably saturated, linear or branched aliphatic C1-C24 hydrocarbon chains, said hydrocarbon chains being optionally substituted or interrupted by one or more heteroatoms;

[0052] -E preferably represents a saturated, linear, or branched divalent C1-C24 hydrocarbon chain, which may optionally contain one or more heteroatoms, such as, for example, N, O, and S.

[0053] -X represents a hydrogen atom or a halogen atom, preferably a hydrogen atom or a chlorine atom.

[0054] Another subject of the present invention relates to masterbatches that can be obtained by the methods defined above.

[0055] Another subject of the invention relates to masterbatches based on at least one organophosphorus additive, at least one initial polymer comprising at least one carbon-carbon unsaturated bond, and at least one 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group, said organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides, and mixtures of these compounds.

[0056] Another subject of the invention is a masterbatch comprising an organophosphorus additive and a polymer modified in the presence of said organophosphorus additive by a 1,3-dipolar grafting agent having at least one nitrile oxidizing dipole and at least one N-substituted or unsubstituted imidazolinone functional group, said organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides, and mixtures of these compounds. More particularly, the masterbatch of the invention may advantageously exhibit at least one of the following preferred features individually or in combination.

[0057] Preferably, the masterbatch has a phosphorus content greater than 600 ppm, and more preferably in the range of 700 ppm to 55,000 ppm.

[0058] Preferably, the organophosphorus additive is selected from triphosphates, phosphonates, hypophosphonates, and mixtures of these compounds.

[0059] Preferably, the organophosphorus additive is selected from triphosphates, phosphonates, and mixtures of these compounds.

[0060] Preferably, the organophosphorus additive is selected from triphosphates and mixtures of these compounds.

[0061] Preferably, the organophosphorus additive corresponds to formula (I):

[0062]

[0063] in:

[0064] -R1 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0065] -R2 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, and (C6-C20)aryl(C1-C20)alkyl; and

[0066] -R3 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0067] Preferably, the organophosphorus additive corresponds to formula (I), wherein:

[0068] -R1 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups;

[0069] -R2 is selected from C1-C20 alkyl, C6-C20 aryl, and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups; and

[0070] -R3 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, where Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups.

[0071] Preferably, the organophosphorus additive corresponds to formula (Ia):

[0072]

[0073] R1a, R2a, and R3a may be the same or different and are selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, and (C6-C20)aryl(C1-C20)alkyl.

[0074] Preferably, in formula (Ia), R1a, R2a, and R3a may be the same or different and are selected from C1-C12 alkyl, C6-C12 aryl, (C1-C12)alkyl(C6-C12)aryl, and (C6-C12)aryl(C1-C12)alkyl.

[0075] Preferably, in formula (Ia), R1a, R2a, and R3a may be the same or different, and are selected from C1-C12 alkyl and C6-C12 aryl.

[0076] Preferably, the organophosphorus additive is selected from tri(ethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, tri-n-octyl phosphate, triisobutyl phosphate, and mixtures thereof.

[0077] Preferably, the modified polymer is a diene elastomer.

[0078] Preferably, the modified polymer is selected from natural rubber, synthetic polyisoprene, polybutadiene, isoprene copolymers, butadiene copolymers, and mixtures of these polymers.

[0079] Preferably, the initial polymer is selected from natural rubber, synthetic polyisoprene, isoprene copolymers, and mixtures of these polymers.

[0080] Preferably, the organophosphorus additive is used at a concentration of 0.3 php; more preferably 0.4 php; and even more preferably 0.5 php.

[0081] Preferably, the organophosphorus additive is used in a concentration ranging from 0.3 php to 20 php, more preferably from 0.4 php to 10 php.

[0082] Preferably, the 1,3-dipolar grafting agent corresponds to general formula (II):

[0083]

[0084] in:

[0085] -A represents a C6-C14 aryl ring, which is optionally substituted by one or more identical or different, preferably saturated, linear or branched aliphatic C1-C24 hydrocarbon chains, said hydrocarbon chains being optionally substituted or interrupted by one or more heteroatoms;

[0086] -E preferably represents a saturated, linear, or branched divalent C1-C24 hydrocarbon chain, which may optionally contain one or more heteroatoms, such as, for example, N, O, and S.

[0087] -X represents a hydrogen atom or a halogen atom, preferably a hydrogen atom or a chlorine atom.

[0088] Preferably, the polymer modified in the presence of the organophosphorus additive has a higher molar content of the grafted 1,3-dipolar grafting agent than the modified polymer obtained under the same grafting conditions but without the organophosphorus additive.

[0089] Another subject of the invention relates to compositions based on at least one or more masterbatches that are defined or can be obtained according to the methods described above.

[0090] Preferably, the composition further comprises at least one reinforcing filler and at least one crosslinking system.

[0091] Another subject of the present invention is a rubber article comprising at least one of the above-described compositions.

[0092] Another subject of the invention relates to pneumatic or non-pneumatic tires comprising at least one of the above-described compositions.

[0093] 4-Detailed Description of the Invention

[0094] As seen above, one subject of the present invention is a method for preparing a masterbatch, the method comprising the following steps:

[0095] (a) In the presence of at least one organophosphorus additive, at least one initial polymer comprising at least one carbon-carbon unsaturated bond is contacted with at least one 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group, said organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides and mixtures thereof.

[0096] (b) Recycle the masterbatch obtained in the previous step.

[0097] For the purposes of this invention, the term "masterbatch" is understood to mean a composition comprising at least one polymer mixed with one or more additives dispersed within the polymer. These additives can be, for example, fillers (optionally reinforcing fillers), plasticizers, or any other type of additive. A masterbatch is a "primary" composition, in the sense that two chemically different compounds are first mixed together, and then this "primary" composition is mixed with other ingredients (a second mixing) to form a final composition, such as a rubber composition used to manufacture tire treads. For example, to obtain a composition, especially a rubber composition, one or more additives (such as, for example, plasticizing oils, crosslinking systems, etc.) are added to a masterbatch consisting of an elastomer and carbon black.

[0098] The masterbatch of the present invention, or the masterbatch that can be obtained by the preparation method of the present invention, comprises at least one organophosphorus additive and at least one polymer modified in the presence of said organophosphorus additive by a 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group.

[0099] Advantageously, the masterbatch of the present invention, or the masterbatch that can be obtained by the preparation method of the present invention, is substantially composed of (more preferably) an organophosphorus additive and a polymer modified in the presence of said organophosphorus additive by a 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group.

[0100] The phrase "consisting essentially of..." followed by one or more features means that components or steps, other than those expressly listed, that do not significantly alter the nature and characteristics of the invention may be included in the methods or materials of the invention.

[0101] The expression "C" i -C j "alkyl" indicates a linear, branched, or cyclic hydrocarbon group containing i to j carbon atoms; i and j are integers.

[0102] The expression "Ci-Cj aryl" represents an aromatic group containing i to j carbon atoms; i and j are integers.

[0103] The expression "(Ci-Cj)alkyl(Ck-Cn)aryl" indicates an alkyl group containing i to j carbon atoms, which is connected to the rest of the molecule via an aryl group containing k to n carbon atoms.

[0104] The expression "(Ci-Cj)aryl(Ck-Cn)alkyl" indicates an aryl group containing ij carbon atoms, which is connected to the rest of the molecule via an alkyl group containing k to n carbon atoms.

[0105] The carbon-containing compounds mentioned in this specification can be of fossil or bio-based origin. In the case of bio-based origin, they can be produced partly or entirely from biomass, or obtained from renewable raw materials derived from biomass. They are particularly polymers, fillers, etc.

[0106] For the purposes of this invention, the expression "parts by weight / hundred parts by weight polymer" (or php) should be understood to mean parts by weight / hundred parts by weight polymer. When the polymer is an elastomer or diene elastomer, "phr" will be mentioned, i.e., "parts by weight / hundred parts by weight elastomer (rubber)", which should be understood to mean parts by weight / hundred parts by weight elastomer (rubber) for the purposes of this invention.

[0107] In this document, unless otherwise explicitly stated, all percentages (%) shown are mass percentages (%).

[0108] Furthermore, any numerical interval expressed as "between a and b" represents a range of values ​​extending from greater than a to less than b (i.e., excluding the limits a and b), while any numerical interval expressed as "a to b" means a range of values ​​extending from a to b (i.e., including the strict limits a and b). In this document, when a numerical interval is expressed as "a to b," it is also preferred to represent the interval represented by the expression "between a and b."

[0109] The terms "modified polymer obtained by grafting," "polymer modified by grafting," or "polymer modified by grafting agent" are understood to refer to polymers containing N-substituted or unsubstituted imidazolinone functional groups introduced along the polymer chain. In practice, modified polymers are obtained in the presence of organophosphorus additives via a grafting reaction using a 1,3-dipolar grafting agent containing at least one substituted or unsubstituted N-imidazolinone functional group and a functional group capable of forming covalent bonds with the unsaturated bonds of the polymer chain (this functional group is an oxonium dipolar). During the grafting reaction, the oxonium dipolar of the 1,3-dipolar grafting agent forms covalent bonds with the unsaturated bonds of the polymer chain. The modified polymer contains N-substituted or unsubstituted imidazolinone functional groups along the side groups of the polymer chain. These functional groups are randomly distributed along the chain.

[0110] It is well known that polymers typically contain at least one main polymer chain. A polymer chain can be referred to as the main chain, provided that all other chains in the polymer are considered side chains, as mentioned in the literature “Glossary of basic terms in polymer science” (IUPAC recommendations 1996), PAC, 1996, 68, 2287, p. 2294.

[0111] The term "carbon-carbon unsaturated bond" is understood to refer to multiple covalent bonds between two carbon atoms; these multiple covalent bonds can be carbon-carbon double bonds or carbon-carbon triple bonds, preferably carbon-carbon double bonds.

[0112] For the purposes of this invention, the term "chain of the initial polymer" is understood to mean the polymer chain prior to the grafting reaction; this chain contains at least one unsaturated bond, particularly a carbon-carbon unsaturated bond, more preferably at least two unsaturated bonds capable of reacting with a 1,3-dipolar grafting agent having at least one nitrile oxide dipole. Thus, the initial polymer is the polymer used as a starting agent during the grafting reaction. The grafting reaction enables the obtaining of a modified polymer starting from the initial polymer.

[0113] Preferably, the initial polymer is an elastomer containing at least one carbon-carbon unsaturated bond, and more preferably a diene elastomer.

[0114] The term “diene elastomer” (or “diene rubber” without distinction), whether natural or synthetic, should be understood in the known manner as meaning an elastomer that is at least partially (i.e., a homopolymer or copolymer) composed of diene monomer units (monomers with two conjugated or non-conjugated carbon-carbon double bonds).

[0115] These diene elastomers can be divided into two categories: "substantially unsaturated" or "substantially saturated". The term "substantially unsaturated" is understood to generally mean diene elastomers that are at least partially derived from conjugated diene monomers and have a diene source (conjugated diene) unit content of greater than 15% (mol%); therefore, diene elastomers such as butyl rubber or EPDM-type copolymers of diene and α-olefins are not included in the foregoing definition, but may be specifically referred to as "substantially saturated" diene elastomers (low or very low diene source unit content, always less than 15 mol%).

[0116] The diene elastomers that can be used in the context of this invention are specifically understood to mean:

[0117] - Any homopolymer of conjugated or non-conjugated diene monomers having 4 to 18 carbon atoms;

[0118] - Any copolymer of a conjugated or non-conjugated diene having 4 to 18 carbon atoms with at least one other monomer.

[0119] Other monomers can be ethylene, olefins, or conjugated or non-conjugated dienes.

[0120] Suitable conjugated dienes include those containing 4 to 12 carbon atoms, particularly 1,3-dienes (especially 1,3-butadiene, for example) and isoprene.

[0121] Suitable nonconjugated dienes include those with 6 to 12 carbon atoms, such as 1,4-hexadiene, ethylidene norbornene, or dicyclopentadiene.

[0122] Suitable olefins include vinyl aromatic compounds containing 8 to 20 carbon atoms and aliphatic α-monoolefins containing 3 to 12 carbon atoms.

[0123] Suitable vinyl aromatic compounds include, for example, styrene, ortho-, meta-, or para-methylstyrene, commercial mixtures of "vinyltoluene", or para-(tert-butyl)styrene.

[0124] Suitable aliphatic α-monoolefins include, in particular, acyclic aliphatic α-monoolefins containing 3 to 18 carbon atoms.

[0125] More specifically, diene elastomers can be:

[0126] - Any homopolymer of a conjugated diene monomer, especially any homopolymer obtained by polymerizing a conjugated diene monomer having 4 to 12 carbon atoms;

[0127] - Any copolymer obtained by copolymerizing one or more conjugated dienes with each other or with one or more vinyl aromatic compounds having 8 to 20 carbon atoms;

[0128] - Copolymers of isobutylene and isoprene (butyl rubber), and halogenated forms of such copolymers, especially chlorinated or brominated forms;

[0129] - Any copolymer obtained by copolymerizing one or more conjugated or non-conjugated dienes with ethylene, α-monoolefins or mixtures thereof, such as, for example, elastomers obtained by copolymerizing ethylene, propylene and non-conjugated diene monomers of the type described above.

[0130] Preferably, the initial polymer is a diene elastomer selected from the following: ethylene / propylene / diene monomer (EPDM) copolymer, butyl rubber (IRR), natural rubber (NR), synthetic polyisoprene (IR), polybutadiene (BR), butadiene copolymer, isoprene copolymer, and mixtures of these elastomers.

[0131] Preferably, the initial polymer is a diene elastomer selected from the following: ethylene / propylene / diene monomer (EPDM) copolymer, butyl rubber (IRR), natural rubber (NR), synthetic polyisoprene (IR), polybutadiene (BR), butadiene / styrene copolymer (SBR), ethylene / butadiene copolymer (EBR), ethylene / isoprene copolymer (EIR), isoprene / butadiene copolymer (BIR) or isoprene / butadiene / styrene copolymer (SBIR), isobutylene / isoprene copolymer (butyl rubber-IIR), isoprene / styrene copolymer (SIR), and mixtures of these elastomers.

[0132] Preferably, the initial polymer is selected from diene elastomers such as ethylene / propylene / diene monomer copolymers, butyl rubber, and mixtures of these rubbers.

[0133] Preferably, the initial polymer is a diene elastomer selected from natural rubber, synthetic polyisoprene, polybutadiene, butadiene copolymer, isoprene copolymer, and mixtures of these elastomers.

[0134] More preferably, the initial polymer is a diene elastomer selected from the following: natural rubber, synthetic polyisoprene, polybutadiene, butadiene / styrene copolymer, ethylene / butadiene copolymer, ethylene / isoprene copolymer, isoprene / butadiene copolymer, isoprene / butadiene / styrene copolymer, isobutylene / isoprene copolymer, isoprene / styrene copolymer, and mixtures of these elastomers.

[0135] Preferably, the initial polymer is selected from diene elastomers including polybutadiene, butadiene copolymers, isoprene copolymers, and mixtures of these elastomers.

[0136] More preferably, the initial polymer is a diene elastomer selected from the following: polybutadiene, butadiene / styrene copolymer, ethylene / butadiene copolymer, isoprene / butadiene copolymer, isoprene / butadiene / styrene copolymer, isobutylene / isoprene copolymer, isoprene / styrene copolymer, and mixtures of these elastomers.

[0137] The following applies to: polybutadiene, especially those with a 1,2-unit content (mol%) between 4% and 80%, or those with a cis-1,4-unit content (mol%) greater than 80%; polyisoprene; butadiene / styrene copolymers, especially those with a glass transition temperature (Tg) according to ASTM. Those copolymers measured by D3418-08 with a Tg between 0°C and -90°C, and more particularly between -10°C and -70°C, a styrene content between 1% by weight and 60% by weight, and more particularly between 20% by weight and 50% by weight, a butadiene moiety with a 1,2-bond content (mol%) between 4% by weight and 75% by weight, and a trans-1,4-bond content (mol%) between 10% by weight and 80% by weight; butadiene / isoprene copolymers, especially those with an isoprene content between 5% by weight and 90% by weight and a Tg between -40°C and -80°C; or isoprene / styrene copolymers, especially those with a styrene content between 5% by weight and 50% by weight and a Tg between -5°C and -50°C. In the case of butadiene / styrene / isoprene copolymers, those with a styrene content between 5% and 50% by weight, more particularly between 10% and 40% by weight, an isoprene content between 15% and 60% by weight, more particularly between 20% and 50% by weight, a butadiene content between 5% and 50% by weight, more particularly between 20% and 40% by weight, a 1,2-unit content (mol%) of the butadiene moiety between 4% and 85%, a trans-1,4-unit content (mol%) of the butadiene moiety between 6% and 80%, a 1,2-plus-3,4-unit content (mol%) of the isoprene moiety between 5% and 70%, and a trans-1,4-unit content (mol%) of the isoprene moiety between 10% and 50%, more generally any butadiene / styrene / isoprene copolymer with a Tg between -5°C and -70°C.

[0138] Preferably, the initial polymer, particularly the diene elastomer, is selected from natural rubber, synthetic polyisoprene, isoprene copolymers, and mixtures of these elastomers. The synthetic polyisoprene is preferably synthetic cis-1,4-polyisoprene. Among these synthetic polyisoprenes, it is preferable to use polyisoprene with a cis-1,4-bond molar content greater than 90%, and even more preferably greater than 98%. Among various isoprene copolymers, isobutene / isoprene, isoprene / ethylene, isoprene / styrene, isoprene / butadiene, or isoprene / butadiene / styrene copolymers will be specifically mentioned.

[0139] The initial polymers that can be used, preferably elastomers, more preferably diene elastomers, can have any microstructure that varies depending on the polymerization conditions used. For example, these polymers can be block, random, sequential, or microsequential polymers and can be prepared in the form of dispersions, emulsions, or solutions. For example, by linking the silicon or tin atoms together in the polymer chains, they can be coupled and / or star-branched.

[0140] As seen above, in the presence of an organophosphorus additive, the initial polymer is contacted with at least one 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group, the organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides and mixtures of these compounds.

[0141] "1,3-Dipole grafting agent" is understood to mean a 1,3-dipolar compound capable of grafting onto a polymer containing at least one carbon-carbon unsaturated bond. A 1,3-dipolar compound (or 1,3-dipolar grafting agent) is an electrically neutral compound having at least one dipole, i.e., carrying both a positive and a negative charge in one of its principal canonical formulas, and capable of forming a [1,3]-dipolar cycloaddition on an unsaturated carbon-carbon bond. For further details, those skilled in the art can refer to the definition given in the IUPAC (International Union of Pure and Applied Chemistry) glossary of names for structure-based organic compounds and reactive intermediates (IUPAC Recommendations 1995, PAC, 1995, 67, 1307).

[0142] The 1,3-dipolar grafting agents that can be used in the context of this invention contain, in addition to their oxynitrile dipoles, N-substituted or unsubstituted imidazolinone functional groups. These compounds and their synthetic methods are described in documents WO2012 / 007442A1, WO2019 / 007883A1 and FR19 / 09030.

[0143] Preferably, the 1,3-dipolar grafting agent that can be used within the scope of this invention corresponds to general formula (II).

[0144]

[0145] in:

[0146] -A represents a C6-C14 aryl ring, which is optionally substituted by one or more identical or different, preferably saturated, linear or branched aliphatic C1-C24 hydrocarbon chains, said hydrocarbon chains being optionally substituted or interrupted by one or more heteroatoms;

[0147] -E preferably represents a saturated, linear, or branched divalent C1-C24 hydrocarbon chain, which may optionally contain one or more heteroatoms, such as, for example, N, O, and S.

[0148] -X represents a hydrogen atom or a halogen atom, preferably a hydrogen atom or a chlorine atom.

[0149] More preferably, the 1,3-dipolar grafting agent is selected from 2,4,6-trimethyl-3-[2-(2-oxoimidazolidine-1-yl)ethoxy]benzyl oxynitrile, 2-[2-(2-oxoimidazolidine-1-yl)ethoxy]-1-naphthonitrile, 2,4,6-trimethyl-3-[2-(2-(3-chloro)oxoimidazolidine-1-yl)ethoxy]benzyl oxynitrile, 2-[2-(2-(3-chloro)oxoimidazolidine-1-yl)ethoxy]-1-naphthonitrile and mixtures of these grafting agents.

[0150] In the method of the present invention, the modification of the polymer by the aforementioned 1,3-dipolar grafting agent is carried out in the presence of at least one organophosphorus additive selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides, and mixtures of these compounds. Surprisingly, the method of the present invention is able to obtain a masterbatch based on the modified polymer and the aforementioned organophosphorus additive, which, once incorporated into a composition (particularly a rubber composition), significantly improves hysteresis.

[0151] For the purposes of this invention, the term "organophosphorus additive" is understood to mean an organic compound containing at least one phosphorus atom and at least one oxygen atom. When this compound is contacted with a 1,3-dipolar grafting agent and an initial polymer containing at least one carbon-carbon unsaturated bond, it promotes the grafting reaction of the 1,3-dipolar grafting agent on the polymer.

[0152] Surprisingly, the applicant discovered that these compounds enable a significant increase in the yield of 1,3-dipolar grafting agents with at least one nitrile oxide dipole on polymers containing at least one carbon-carbon unsaturated bond (particularly diene elastomers).

[0153] More preferably, the organophosphorus additive is selected from triphosphates, phosphonates, hypophosphonates, and mixtures of these compounds.

[0154] These compounds are known and are used, in particular, as adhesives or flame retardants in the construction industry. They are commercially available from suppliers such as ABCR, Sigma-Aldrich, and Alfa Chemistry.

[0155] More preferably, the organophosphorus additive is selected from triphosphates, phosphonates, and mixtures of these compounds.

[0156] More preferably, the organophosphorus additive is selected from triphosphates and mixtures of these compounds.

[0157] Among the grafting additives that can be used within the scope of this invention, compounds of formula (I) may be mentioned:

[0158]

[0159] in:

[0160] -R1 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0161] -R2 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0162] -R3 is selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra group, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl;

[0163] Advantageously, compared with compounds of the prior art, the compounds of formula (I) can be used to obtain modified polymers more quickly and in higher yields by grafting and by incorporating side-chain imidazole functional groups.

[0164] More preferably, the organophosphorus additive is a compound of formula (I), wherein:

[0165]

[0166] in:

[0167] -R1 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups;

[0168] -R2 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups;

[0169] -R3 is selected from C1-C20 alkyl, C6-C20 aryl and O-Ra groups, where Ra is a group selected from C1-C20 alkyl and C6-C20 aryl groups.

[0170] Among the grafting additives of formula (I), compounds corresponding to formula (Ia) are particularly preferred. They enable the improvement of the grafting rate of 1,3-dipolar grafting agents on polymers containing at least one carbon-carbon unsaturated bond (especially diene elastomers). Advantageously, these compounds of formula (Ia) enable the attainment of very good grafting rates at room temperature, particularly at or below 35°C, and more preferably at grafting temperatures between 5°C and 35°C.

[0171] Therefore, preferably, the organophosphorus additive corresponds to formula (Ia):

[0172]

[0173] R1a, R2a, and R3a may be the same or different and are selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, and (C6-C20)aryl(C1-C20)alkyl.

[0174] Preferably, in formula (Ia), R1a, R2a, and R3a may be the same or different and are selected from C1-C12 alkyl, C6-C12 aryl, (C1-C12)alkyl(C6-C12)aryl, and (C6-C12)aryl(C1-C12)alkyl.

[0175] Preferably, in formula (Ia), R1a, R2a, and R3a may be the same or different, and are selected from C1-C12 alkyl and C6-C12 aryl.

[0176] More preferably, the organophosphorus additive is selected from tri(ethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, tri-n-octyl phosphate, triisobutyl phosphate, and mixtures thereof.

[0177] The order in which the various starting reagents for the grafting reaction come into contact is not important, and they can be contacted in any known manner.

[0178] According to a preferred embodiment, the 1,3-dipolar grafting agent, the initial polymer, and the organophosphorus additive can be contacted simultaneously when introduced into, for example, a mixer.

[0179] According to another embodiment of the invention, these incorporations may also be staggered over time by tens of seconds to several minutes. Therefore, it is preferable to contact the organophosphorus additives with the polymer before contacting them with the 1,3-dipolar grafting agent.

[0180] According to another preferred embodiment, the organophosphorus additives are contacted with a 1,3-dipolar grafting agent, and then they are contacted with the polymer.

[0181] The grafting of the 1,3-dipolar grafting agent onto the initial polymer proceeds via a [3+2] cycloaddition of the oxidizing nitrile dipole of the grafting agent onto the carbon-carbon unsaturated bonds of the initial polymer chain, in the presence of the aforementioned organophosphorus additive. During this reaction, the oxidizing nitrile dipole of the 1,3-dipolar grafting agent forms a covalent bond with the chain of the initial polymer. A modified polymer is obtained, which carries along its main chain one or more side-group N-substituted or unsubstituted imidazolinone functional groups generated by the grafting reaction of the 1,3-dipolar grafting agent, randomly distributed along the chain.

[0182] Surprisingly, the organophosphorus additive promoted this cycloaddition reaction, thus increasing the amount of 1,3-dipolar grafting agent grafted onto the chains of the initial polymer. Due to the presence of the organophosphorus additive, the 1,3-dipolar grafting agent can be rapidly and easily grafted onto the initial polymer at atmospheric pressure, at temperatures below 35°C, more preferably in the range of 5°C to 35°C, and even more preferably in the range of 10°C to 35°C, without the need for subsequent heat treatment. Furthermore, a very good grafting yield was obtained. "Grafting yield" or "yield" is understood to mean, in molar percentage, the amount of 1,3-dipolar grafting agent grafted onto the chains of the initial polymer (particularly diene elastomer) relative to the amount of 1,3-dipolar grafting agent introduced as a starting agent. The grafting yield can be determined by conventional polymer analysis methods, such as... 1 To determine this, use 1H NMR analysis.

[0183] According to a particularly preferred embodiment of the method of the present invention, steps (a) and (b) are performed at a temperature below or equal to 35°C, preferably between 5°C and 35°C, and even more preferably between 10°C and 35°C.

[0184] According to another embodiment of the invention, after the contact step (a), the method may further include a heat treatment step (a'). Preferably, the heat treatment step (a') is performed at a temperature above 35°C, more preferably at a temperature above or equal to 36°C, even more preferably at a temperature in the range of 36°C to 180°C, and even more preferably at a temperature in the range of 36°C to 150°C.

[0185] In the presence of organophosphorus additives, grafting of 1,3-dipolar grafting agents can be carried out in bulk, for example in a closed mixer or an open mixer (such as a two-roll mill). It can also be carried out continuously or batchwise in solution.

[0186] According to one embodiment of the invention, the molar content (in molar percentage (mol%)) of the contacting 1,3-dipolar grafting agent can be in the range of 0.01 mol% to 10 mol%, preferably 0.01 mol% to 5 mol%. "Molar content of 1,3-dipolar grafting agent" is understood to mean the number of moles of 1,3-dipolar grafting agent grafted onto each 100 moles of polymer monomer unit.

[0187] According to one embodiment of the invention, an organophosphorus additive is used at a content greater than or equal to 0.3 parts by weight per hundred parts by weight of polymer (php), more preferably greater than or equal to 0.4 php, and even more preferably greater than or equal to 0.5 php. It is also preferred that the organophosphorus additive is used at a content ranging from 0.3 php to 30 php, more preferably from 0.4 php to 25 php.

[0188] Another subject of the present invention is the masterbatch obtained by the method described above.

[0189] Another subject of the invention is a masterbatch comprising at least one organophosphorus additive and at least one polymer modified in the presence of the organophosphorus additive by a 1,3-dipolar grafting agent having at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group, said organophosphorus additive being selected from triphosphates, phosphonates, hypophosphonates, phosphine oxides and mixtures thereof.

[0190] The modified polymer obtained by grafting the above-mentioned 1,3-dipolar grafting agent onto the masterbatch of the present invention in the presence of the organophosphorus additive has a higher molar content of the grafted 1,3-dipolar grafting agent than the modified polymer obtained under the same grafting conditions but without the organophosphorus additive. The masterbatch of the present invention, due to its higher molar content of the grafted 1,3-dipolar grafting agent, exhibits different properties compared to the modified polymer obtained under the same grafting conditions (i.e., the same temperature, time, reagent addition order, etc.) but without the organophosphorus additive used in the context of this invention.

[0191] For the purposes of this invention, "molar content of the grafted 1,3-dipolar grafting agent" is understood to mean the number of moles of 1,3-dipolar grafting agent grafted onto each 100 moles of polymer monomer unit. This molar content can be determined by conventional measurements used to characterize polymers, such as, for example, NMR.

[0192] Preferably, the masterbatch has a phosphorus content greater than 600 ppm, more preferably in the range of 700 ppm to 55,000 ppm (ppm = parts per million), and the modified polymer constituting the masterbatch has a molar content of the grafted 1,3-dipolar grafting agent greater than the molar content of the 1,3-dipolar grafting agent in the modified polymer obtained under the same grafting conditions but without organophosphorus additives.

[0193] The phosphorus content was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) according to the following method.

[0194] Preferably, the modified polymer of the masterbatch is the polymer already described above. Preferably, the modified polymer is an elastomer, more preferably a diene elastomer, having N-substituted or unsubstituted imidazolinone functional groups along its chain. Even more preferably, the modified polymer is selected from natural rubber, synthetic polyisoprene, polybutadiene, butadiene copolymers, isoprene copolymers, and mixtures of these polymers, having N-substituted or unsubstituted imidazolinone functional groups along their chains.

[0195] The masterbatch containing at least one nitrile dipolar and at least one N-substituted or unsubstituted imidazolinone functional group, along with the 1,3-dipolar grafting agent and organophosphorus additive, are those already described above, including their preferred embodiments. Preferably, the organophosphorus additive is a compound of formula (I) above, including its preferred form. More preferably, the organophosphorus additive corresponds to formula (Ia) above, including its preferred embodiments. Another subject of the invention is a composition based on at least one or more masterbatches defined or obtainable by the methods of the invention. This composition may preferably further comprise any additives known to those skilled in the art, such as reinforcing or non-reinforcing fillers, dyes, antioxidants, resins, flame retardants, lubricants, etc.

[0196] Another subject of the present invention relates to a rubber composition based on at least one or more defined or obtainable masterbatches according to the above methods, at least one reinforcing filler, and at least one crosslinking system.

[0197] The statement “composition based” should be understood to mean that the composition comprises a mixture of various components used and / or in-situ reaction products, some of which are capable of reacting and / or intended to react with each other at least partially during various stages of the composition’s manufacture; thus, the composition may be in a fully or partially crosslinked or non-crosslinked state.

[0198] Here, "filler" is understood to mean any type of filler, whether it is reinforced, unreinforced, or inert.

[0199] According to one embodiment, the rubber composition of the present invention may contain one or more reinforcing fillers.

[0200] Any type of "reinforcing" filler that can enhance a rubber composition that can be used to make a particular tire may be used, such as organic fillers (e.g., carbon black), inorganic fillers (e.g., silica), or a mixture of both.

[0201] All carbon blacks, especially those conventionally used in tires or their treads, are suitable as carbon blacks. Of the latter, more particular reference will be made to reinforcing carbon blacks of the 100, 200, and 300 series, or carbon blacks of the 500, 600, or 700 series (ASTM D-1765-2017 grade), such as, for example, N115, N134, N234, N326, N330, N339, N347, N375, N550, N683, or N772. These carbon blacks can be used alone as commercially available, or in any other form, such as as a carrier for some rubber additives used.

[0202] In this document, the term "reinforcing inorganic filler" should be understood to mean any inorganic or mineral filler, regardless of its color and origin (natural or synthetic), which, in contrast to carbon black, is also referred to as "white filler," "transparent filler," or even "non-black filler," capable of independently reinforcing rubber compositions intended for use in tire manufacturing without the need for any means other than intermediate coupling agents. In a known manner, certain reinforcing inorganic fillers are particularly characterized by the presence of hydroxyl groups (-OH) on their surface.

[0203] Silica-based mineral fillers, preferably silica (SiO2), or alumina-based mineral fillers, particularly alumina (Al2O3), are particularly suitable as reinforcing inorganic fillers. The silica used can be any reinforcing silica known to those skilled in the art, especially those with a BET specific surface area and CTAB specific surface area both less than 450 m². 2 / g, preferably at 30m 2 / g to 400m 2 / g, especially 60m 2 / g to 300m 2 Any precipitated silica or pyrolytic silica within the range of / g.

[0204] In this disclosure, the BET specific surface area of ​​inorganic fillers (e.g., silica) is determined by gas adsorption using the Brunauer-Emmett-Teller method described in "The Journal of the American Chemical Society" (Vol. 60, p. 309, February 1938), more specifically according to a method adapted from standard NF ISO 5794-1 (Appendix E) of June 2010 [multi-point (5-point) volumetric method - gas: nitrogen - degassed under vacuum: 1 hour at 160°C - relative pressure p / po range: 0.05 to 0.17]. For inorganic fillers (e.g., silica), the CTAB specific surface area value is determined according to standard NF ISO 5794-1 (Appendix G) of June 2010. This method is based on the adsorption of CTAB (N-hexadecyl-N,N,N-trimethylammonium bromide) on the "outer" surface of the reinforcing filler.

[0205] Any type of precipitated silica can be used, particularly highly dispersible precipitated silica (“highly dispersible” or “highly dispersible silica” is referred to as “HDS”). These precipitated silicas (which may or may not be highly dispersible) are well known to those skilled in the art. For example, the silica described in applications WO03 / 016215-A1 and WO03 / 016387-A1 may be mentioned. Among commercially available HDS silicas, those from Evonik are particularly suitable. 5000GR and 7000GR silica, or from Solvay 1085GR 1115MP 1165MP Premium 200MP and HRS 1200MP silica. As a non-HDS silica, the following commercially available silica can be used: from Evonik... VN2GR and VN3GR silica, from Solvay 175GR silica, or Hi-Sil EZ120G(-D), Hi-Sil EZ160G(-D), Hi-Sil EZ200G(-D), Hi-Sil 243LD, Hi-Sil 210 and Hi-Sil HDP 320G from PPG.

[0206] It is not important what physical state the reinforcing inorganic filler is provided in, whether it is in the form of powder, microspheres, granules, or beads, or any other suitable densification form. Of course, reinforcing inorganic filler is also understood to refer to different reinforcing inorganic fillers, especially mixtures of silica as described above.

[0207] Those skilled in the art will understand that reinforcing fillers with other properties can be used as alternatives to the aforementioned reinforcing inorganic fillers, provided that the reinforcing filler with the other properties is covered with an inorganic layer such as silica, or has functional sites, particularly hydroxyl sites, on its surface that require the use of a coupling agent to form bonds between the reinforcing filler and the diene elastomer. For example, carbon black partially or completely covered with silica, or silica-modified carbon black, such as, but not limited to, the CRX2000 or CRX4000 series from Cabot Corporation, can be mentioned. Type of packing.

[0208] To couple an inorganic filler to a diene elastomer, a coupling agent (or binder) that is at least bifunctional can be used in a known manner to provide a connection between the inorganic filler (its particle surface) and the diene elastomer with satisfactory chemical and / or physical properties. In particular, at least bifunctional organosilanes or polyorganosiloxanes are used. The term "bifunctional" is understood to mean that the compound has a first functional group capable of interacting with the inorganic filler and a second functional group capable of interacting with the diene elastomer. For example, such a bifunctional compound may contain a first functional group containing silicon atoms and a second functional group containing sulfur atoms, the first functional group being capable of interacting with the hydroxyl groups of the inorganic filler and the second functional group being capable of interacting with the diene elastomer.

[0209] Preferably, the organosilane is selected from organosilane polysulfides (symmetrical or asymmetrical), such as bis(3-triethoxysilylpropyl)tetrasulfide, abbreviated as TESPT, sold by Evonik under the name Si69, or bis(triethoxysilylpropyl)disulfide, abbreviated as TESPD, sold by Evonik under the name Si75, polyorganosiloxanes, mercaptosilanes, blocked mercaptosilanes, such as S-(3-(triethoxysilyl)propyl)octanethioate, sold by Momentive under the name NXTsilane. More preferably, the organosilane is an organosilane polysulfide.

[0210] The rubber composition of the present invention comprises a crosslinking system.

[0211] The crosslinking system can be any type of system known to those skilled in the art of tire rubber compositions. It can be, in particular, based on sulfur, and / or based on peroxides and / or based on bismaleimides.

[0212] Preferably, the crosslinking system is based on sulfur; thus, the crosslinking system is called a vulcanization system. Sulfur can be provided in any form, particularly as molecular sulfur or as a sulfur donor. It is also preferred that at least one vulcanization accelerator is present, and optionally, and also preferably, various known vulcanization activators can be used, such as zinc oxide, stearic acid or equivalent compounds, such as stearates and transition metal salts, guanidine derivatives (especially diphenylguanidine), or known vulcanization retarders.

[0213] Sulfur is used in a preferred amount between 0.5 phr and 12 phr, particularly between 1 phr and 10 phr. The vulcanization accelerator is used in a preferred amount between 0.5 phr and 10 phr, more preferably between 0.5 phr and 5.0 phr.

[0214] As accelerators, any compound capable of acting as an accelerator for the vulcanization of diene elastomers in the presence of sulfur can be used, particularly thiazole-type accelerators and their derivatives, or sulfenamide, thiuram, dithiocarbamate, dithiophosphate, thiourea, and xanthate-type accelerators. Examples of such accelerators include, in particular, the following compounds: 2-mercaptobenzothiazole disulfide (abbreviated “MBTS”), N-cyclohexyl-2-benzothiazole sulfenamide (“CBS”), N,N-dicyclohexyl-2-benzothiazole sulfenamide (“DCBS”), N-(tert-butyl)-2-benzothiazole sulfenamide (“TBBS”), N-(tert-butyl)-2-benzothiazole sulfenimide (“TBSI”), tetrabenzylthiuram disulfide (“TBZTD”), zinc dibenzyl dithiocarbamate (“ZBEC”), and mixtures of these compounds.

[0215] The compositions according to the invention may also contain all or some of the additives and processing aids known to those skilled in the art and commonly used in compositions, particularly for pneumatic or non-pneumatic tires, especially in rubber compositions for the tread, such as plasticizers (e.g., plasticizing oils and / or plasticizing resins), pigments, protective agents (e.g., anti-ozone waxes, chemical anti-ozone agents, antioxidants, anti-fatigue agents) or reinforcing resins (e.g., as described in application WO 02 / 10269).

[0216] The compositions according to the invention can be prepared in a suitable mixer using two consecutive preparation stages known to those skilled in the art:

[0217] - The first stage of thermomechanical processing or kneading (“non-production” stage), which can be carried out in a single thermomechanical stage, involves the introduction of all necessary components, except for the crosslinking system, particularly the masterbatch according to the invention, fillers, and optionally various other additives, into a suitable mixer such as a standard closed mixer (e.g., “Banbury” type). The fillers can be incorporated into the masterbatch in one or more parts during thermomechanical kneading. The non-production stage can be carried out at high temperatures, typically between 110°C and 200°C, preferably between 130°C and 185°C, for a period of 2 to 10 minutes.

[0218] - The second stage of machining (the "production" stage) is carried out in an open mixer (e.g., a two-roll mill) after the mixture obtained in the first non-production stage has been cooled to a lower temperature (typically below 120°C, for example, between 40°C and 100°C). The crosslinking system is then incorporated, and the combined mixture is then mixed for several minutes, for example, between 5 and 15 minutes.

[0219] The resulting final rubber composition is then calendered into, for example, sheets or plates specifically for laboratory characterization, or extruded into a rubber semi-finished product (or molding element) that can be used as, for example, the tread of a pneumatic or non-pneumatic tire.

[0220] The rubber composition may be in an uncured state (before crosslinking or vulcanization) or in a cured state (after crosslinking or vulcanization), and may be a semi-finished product that can be used in pneumatic or non-pneumatic tires.

[0221] Crosslinking of the composition can be carried out in a manner known to those skilled in the art, for example, under pressure at a temperature between 80°C and 200°C.

[0222] Another subject of the invention relates to rubber articles comprising at least one rubber composition as defined above. The articles can be of any type, such as hoses, tubing, gaskets, O-rings, drive belts, engine mounts, vibration damping systems, window molding elements, window or body sealing molding elements, cable insulators, shoe soles, rubber pads, conveyor belts, semi-finished products for pneumatic or non-pneumatic tires, or pneumatic or non-pneumatic tires.

[0223] Semi-finished products for pneumatic or non-pneumatic tires are rubber products intended for use in the manufacture of pneumatic or non-pneumatic tires. They can be any type of rubber strip, such as, in particular, tread, sublayers, crown reinforcing plies (e.g., working plies, protective plies, or hoop plies), carcass reinforcing plies, sidewall plies, bead plies, protective plies, bottom plies, block plies, and other plies that provide interfaces between the aforementioned areas of the tire. Preferably, the semi-finished product is the tread.

[0224] Another subject of the invention relates to pneumatic or non-pneumatic tires comprising at least one rubber composition as defined above.

[0225] A "pneumatic tire" is understood to mean a tire designed to form a cavity through mating with a supporting element (such as a rim), which can be pressurized to pressures above atmospheric pressure. Conversely, a non-pneumatic tire cannot be pressurized. Therefore, a non-pneumatic tire is a toroidal body made of at least one polymer material, designed to perform the function of a tire but not to bear inflation pressure. Non-pneumatic tires can be solid or hollow. A hollow non-pneumatic tire can contain air, but at atmospheric pressure; that is, it does not have the inflation stiffness provided by the inflation gas at pressures above atmospheric pressure.

[0226] The pneumatic or non-pneumatic tires according to the invention are intended to be mounted on any type of vehicle, such as passenger vehicles, two-wheeled vehicles, heavy vehicles, agricultural vehicles, construction vehicles, or aircraft, or more generally, on any rolling equipment. Detailed Implementation

[0227] Example

[0228] The following embodiments illustrate the present invention; however, the present invention should not be limited to these embodiments.

[0229] 1.1 - Tests and Measurements Used

[0230] 1.1.1 Determination of the molar content of the grafted 1,3-dipolar grafting agent

[0231] The molar content of the grafted 1,3-dipolar grafting agent was determined by NMR analysis. Spectra were acquired using a 500MHz Bruker spectrometer equipped with a 5mm BBFO Z-grade cryoprobe. 1 Quantitative 1H NMR experiments use a simple 30° pulse sequence with a 5-second repetition delay between each acquisition. The sample is dissolved in deuterated chloroform (CDCl3) to obtain a “lock-in” signal.

[0232] 1.1.2: Tensile test (after curing)

[0233] These tensile tests enable the determination of elastic stress and fracture properties. Unless otherwise specified, these tests are performed according to French Standard NF T 37 of December 2005. The nominal secant modulus (or apparent stress, in MPa, relative to dimensionless strain) is measured at 23°C during a second elongation (i.e., after the conditioning cycle at the elongation provided for the measurement itself) at 100% elongation (denoted as MA100) and / or 300% elongation (denoted as MA300).

[0234] The MA100 / MA300 ratio is an indicator of the composition's reinforcing properties; a higher value indicates better reinforcing properties. For readability, results based on performance are shown in base 100, with a value of 100 designated as a control. A value less than 100 indicates decreased reinforcing properties of the composition, while a value greater than 100 indicates increased properties.

[0235] 1.1.3 Kinetic properties (after curing)

[0236] Kinetic properties were measured on a viscosity analyzer (Metravib VA4000) according to standard ASTM D 5992-96. The response of vulcanized composition samples (cylindrical test specimens, 2 mm thick and 10 mm in diameter) subjected to simple alternating sinusoidal shear stress at 10 Hz at 60 °C was recorded. Strain amplitude scans were performed from 0.1% to 100% peak-to-peak (outward cycle) and then from 100% to 0.1% peak-to-peak (backward cycle). The results used are expressed as the loss factor tan(δ). For the backward cycle, the maximum observed tan(δ) value is indicated using tan(δ). max在60℃下 express.

[0237] For clarity, results will be expressed in base 100, with a value of 100 designated as the control. Values ​​less than 100 indicate tan(δ). max在60℃下 A decrease in the value of tan(δ) results in a decrease in hysteresis (and thus an improvement in rolling resistance), while a value greater than 100 indicates a decrease in tan(δ). max在60℃下 The increase in value leads to an increase in hysteresis (and therefore a decrease in rolling resistance).

[0238] 1.1.4: 1,3-Dipole Grafting Agent Used

[0239] 2,4,6-trimethyl-3-[2-(2-oxoimidazolidine-1-yl)ethoxy]benzyl oxynitrile was synthesized according to the scheme described in Example 1 of document WO2012 / 007441-A1.

[0240] 2-[2-(2-oxoimidazolidine-1-yl)ethoxy]-1-naphthyl nitrile was synthesized according to the scheme described in Example I of document WO2019 / 007881.

[0241] 1.1.5: Organophosphorus additives

[0242] The organophosphorus additive tri(ethylhexyl) phosphate is sold by Sigma Aldrich under reference number 289922-25ML.

[0243] 1.1.6: Measurement of Phosphorus Content

[0244] The phosphorus content in masterbatches or modified polymers in the prior art was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Spectra were obtained on an Arcos spectrometer from Spectro Ametek. Samples were dissolved in sealed test tubes at 130 °C by acid mineralization (80 / 20 vol / vol concentrated nitric acid / concentrated hydrochloric acid mixture). The resulting solution was then analyzed by ICP-AES at λ = 178.287 nm.

[0245] 1.2: Test No. 1

[0246] The purpose of this test is to demonstrate the advantages offered by the method for preparing masterbatch according to the present invention compared with methods for preparing modified elastomers according to the prior art.

[0247] Therefore, the modified elastomer that does not conform to the present invention and the masterbatch that conforms to the present invention are prepared according to the following scheme. The number of grafted imidazolinone functional groups is measured by the yield of the grafting reaction.

[0248] Preparation of modified elastomers that do not conform to the present invention:

[0249] At 23°C, 15 g of elastomer and grafting agent (i.e., 0.63 g of 2,4,6-trimethyl-3-[2-(2-oxoimidazol-1-yl)ethoxy]benzyl oxynitrile (grafting agent A) (i.e., 1 mol%); or 0.65 g of 2-[2-(2-oxoimidazol-1-yl)ethoxy]-1-naphthyl oxynitrile (grafting agent B) (i.e., 1 mol%)) are simultaneously introduced into a rolling mill. The mixture is tumbled 12 times to homogenize it. The modified elastomer is then recovered (in a scheme without a heat treatment step).

[0250] When the process includes a heat treatment step, the mixture from the previous step is placed in a press and heated at 120°C for 10 minutes. The modified elastomer is then recovered. Grafting rate is determined by… 1 The results were confirmed by H NMR analysis and are listed in Table 1.

[0251] Preparation of masterbatch conforming to the present invention:

[0252] At 23°C, 15 g of elastomer, 5 phr of organophosphorus additive, and grafting agent (i.e., 0.63 g of 2,4,6-trimethyl-3-[2-(2-oxoimidazol-1-yl)ethoxy]benzyl oxynitrile (grafting agent A) (i.e., 1 mol%); or 0.65 g of 2-[2-(2-oxoimidazol-1-yl)ethoxy]-1-naphthyl oxynitrile (grafting agent B) (i.e., 1 mol%)) are simultaneously introduced into a rolling mill. The mixture is tumbled 12 times to homogenize it. The masterbatch conforming to the present invention (without a heat treatment step) is recovered.

[0253] When the process includes a heat treatment step, the mixture from the previous step is placed in a press and heated at 120°C for 10 minutes. The modified elastomer is then recovered. Grafting rate is determined by… 1 The results were confirmed by H NMR analysis and are listed in Table 1.

[0254] [Table 1]

[0255]

[0256]

[0257] NR: Natural Rubber

[0258] IR-1 = Nastsyn 2200 sold by Goodyear, 3,4-unit content = 0.5 wt%, trans-1,4-unit content = 1.9 wt%, cis-1,4-unit content = 97.6 wt%, Mw = 1044 kg / mol, Ip = 3.6

[0259] IR-2: SKI-3 polyisoprene from Nizhnekamsk, Mn = 375,000 g / mol and Ip = 3.6, with cis-1,4 unit content >96% by weight.

[0260] Tests 1, 3, 5 and 7 are modified elastomers that do not conform to the present invention, while tests 2, 4, 6 and 8 are masterbatches that conform to the present invention, the masterbatches comprising modified elastomers as mixtures with organophosphorus additives.

[0261] Regardless of the type of elastomer used and the nature of the grafting agent used, it was observed that for the same amount of grafting agent introduced, the masterbatch according to the invention has a greater molar content of grafted 1,3-dipolar grafting agent with imidazolinone functional groups grafted onto the modified elastomer in the absence of organophosphorus additives. In each case, the grafting rate during masterbatch preparation is greater than the grafting rate of the method for obtaining the modified elastomer that does not conform to the invention.

[0262] 1.3 Test No. 2

[0263] The purpose of this test is to demonstrate that the hysteresis of the rubber composition prepared from the masterbatch of the present invention is improved compared with that of prior art rubber compositions.

[0264] The contents of various components in the compositions shown in Table 2 are expressed as phr (parts by weight / hundred parts by weight elastomer).

[0265] The grafting agent (2) introduced into compositions C2 and C4 has the same molar content, which is 0.3 mol% relative to the elastomer used.

[0266] [Table 2]

[0267]

[0268]

[0269] (1) SKI-3 polyisoprene from Nizhnekamsk, Mn = 375,000 g / mol and Ip = 3.6, with a content of cis-1,4 units > 96 wt%;

[0270] (2) 2-[2-(2-oxoimidazolidine-1-yl)ethoxy]-1-naphthyl nitrile;

[0271] (3) Tri(ethylhexyl) phosphate;

[0272] (4) Silica, Zeosil 1165MP sold by Solvay;

[0273] (5) N234 grade carbon black, sold by Cabot Corporation;

[0274] (6) Bis[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) silane, sold by Evonik under reference number Si69;

[0275] (7) N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, sold by Flexsys under reference number Santoflex 6-PPD;

[0276] (8) 2,2,4-trimethyl-1,2-dihydroquinoline sold by Flexsys;

[0277] (9) Zinc oxide (industrial grade) sold by Umicore;

[0278] (10) Stearin, Pristerene 4031 sold by Uniqema;

[0279] (11) N-cyclohexyl-2-benzothiazole sulfenamide, sold by Flexsys under reference number Santocure CBS.

[0280] *In the form of masterbatch.

[0281] The composition is prepared as follows:

[0282] First, a modified elastomer of composition C2 and masterbatches of compositions C3 and C4 are prepared.

[0283] The modified elastomer of composition C2 was prepared as follows: 1,3-dipolar grafting agent (2) and unmodified diene elastomer (1) were introduced into a Haake-type closed mixer at a temperature of 23°C. They were mixed at 23°C for 30 seconds; then, the resulting mixture was heat-treated at 110°C for 1 minute and 30 seconds. The diene elastomer modified by the 1,3-dipolar grafting agent was then recovered.

[0284] Composition C3 comprises a masterbatch based on an organophosphorus additive (3) and an unmodified diene elastomer (1). This masterbatch is obtained by introducing the unmodified diene elastomer (1) and the organophosphorus additive (3) into a Haake-type closed mixer at 23°C; then mixing them at 23°C for 30 seconds. The resulting mixture is then heat-treated at 110°C for 1 minute and 30 seconds. The masterbatch is then recovered.

[0285] Composition C4 comprises a masterbatch conforming to the present invention, namely a masterbatch based on an organophosphorus additive (3) and a diene elastomer modified by a grafting agent (2) in the presence of the organophosphorus additive. This masterbatch is obtained by introducing the unmodified diene elastomer (1) and the organophosphorus additive (3) into a Haake-type closed mixer at 23°C; then mixing them at 23°C for 30 seconds. Next, the 1,3-dipolar grafting agent (2) is added, and then mixed at 23°C for 30 seconds. The resulting mixture is then heat-treated at 110°C for 1 minute and 30 seconds. The masterbatch conforming to the present invention is then recovered.

[0286] These compositions, C1 to C4, are then prepared.

[0287] For each composition, the unmodified diene elastomer (1) or modified elastomer or masterbatch of composition C3 obtained above, or the masterbatch conforming to the present invention of composition C4, is introduced into a Haake-type closed mixer, along with 40 phr of silica (4) and a coupling agent (6). These components are mixed at 110-120°C for one minute. Then, the remaining silica (20 phr), antioxidant (7), paraffin, carbon black (5), TMQ (8), and stearic acid (10) are introduced. After mixing for one minute, zinc oxide (9) is added. Thirty seconds after this addition, a plunger stroke is performed to homogenize the combined mixture. The composition is mixed at 160°C (drop temperature) for 5 minutes, and then cooled on a rolling mill.

[0288] When the temperature of the composition is below 50°C, a crosslinking system (sulfur and accelerator (11)) is introduced; then 12 inversions are performed to homogenize the mixture.

[0289] The resulting compositions were then calendered into sheets (2 to 3 mm thick) or thin sheets of rubber for measuring their physical or mechanical properties. The rubber properties of these compositions were measured after curing at 150°C for 60 minutes. The results are listed in Table 3.

[0290] [Table 3]

[0291] Composition C1 C2 C3 C4 MSA300 / MSA10 (based on a base of 100) 100 122 99 122 Tan(δ)max at 60℃ (based on a base of 100) 100 64 77 55

[0292] As can be seen from Table 3, consistent with expectations, the use of an elastomer modified with 2-[2-(2-oxoimidazolidine-1-yl)ethoxy]-1-oxonaphthonitrile can improve the hysteresis of composition C2 compared with composition C1.

[0293] Compared to composition C1, using a masterbatch that does not conform to the present invention can improve the hysteresis of composition C3, but does not improve the reinforcing properties. However, this improvement in hysteresis is still less than the improvement obtained by composition C2.

[0294] When using the masterbatch conforming to the present invention (composition C4), improvements in reinforcing properties were observed in the same manner as when using modified elastomers of the prior art (comparison between compositions C1 and C2). However, unexpectedly, for the same amount of 1,3-dipolar grafting agent used in compositions C2 and C4, a significant improvement in hysteresis was observed in composition C4 conforming to the present invention compared to composition C2 which does not conform to the present invention.

[0295] Therefore, compared with existing rubber compositions, the masterbatch conforming to the present invention can improve the hysteresis of the rubber composition.

[0296] 1.4 Test 3.

[0297] Test 2 was repeated, but the polyisoprene used was different from that used in test number 2.

[0298] The contents of various components in the compositions shown in Table 4 are expressed as phr (parts by weight / hundred parts by weight elastomer).

[0299] The molar content of the 1,3-dipolar grafting agent (2) introduced into compositions C6 and C8 is the same. It is 0.3 mol% relative to the elastomer used.

[0300] [Table 4]

[0301]

[0302]

[0303] (1) Natsyn 2000 synthesized polyisoprene sold by Goodyear, containing 99.35% by weight of cis-1,4-isoprene units and 0.65% by weight of 3,4-isoprene units; Mn = 375,000 g / mol and Ip = 3.6;

[0304] (2) 2-[2-(2-oxoimidazolidine-1-yl)ethoxy]-1-naphthyl nitrile;

[0305] (3) Tri(ethylhexyl) phosphate;

[0306] (4) Silica, Zeosil 1165MP sold by Solvay;

[0307] (5) N234 grade carbon black, sold by Cabot Corporation;

[0308] (6) Bis[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) silane, sold by Evonik under reference number Si69;

[0309] (7) N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, sold by Flexsys under reference number Santoflex 6-PPD;

[0310] (8) 2,2,4-trimethyl-1,2-dihydroquinoline sold by Flexsys;

[0311] (9) Zinc oxide (industrial grade) sold by Umicore;

[0312] (10) Stearin, Pristerene 4031 sold by Uniqema;

[0313] (11) N-cyclohexyl-2-benzothiazole sulfenamide, sold by Flexsys under reference number Santocure CBS.

[0314] *In the form of masterbatch.

[0315] The masterbatch and composition were prepared according to the scheme described in Test 2.

[0316] The resulting compositions were then calendered into sheets (2 to 3 mm thick) or thin sheets of rubber for measuring their physical or mechanical properties. The rubber properties of these compositions were measured after curing at 150°C for 60 minutes. The results are listed in Table 5.

[0317] [Table 5]

[0318] Composition C5 C6 C7 C8 MSA300 / MSA100 (based on a base of 100) 100 123 102 124 Tan(δ)max at 60℃ (based on a base of 100) 100 61 89 44

[0319] When using the masterbatch conforming to the present invention (composition C8), improvements in reinforcing properties were observed in the same manner as when using modified elastomers of the prior art (comparison between compositions C5 and C6). However, unexpectedly, for the same amount of 1,3-dipolar grafting agent introduced into compositions C6 and C8, a significant improvement in hysteresis was observed in composition C8 conforming to the present invention compared to composition C6 which does not conform to the present invention.

[0320] Therefore, compared with existing rubber compositions, the masterbatch conforming to the present invention can better improve the hysteresis of rubber compositions.

Claims

1. Process for the preparation of a masterbatch comprising the following steps: (a) contacting at least one initial polymer comprising at least one carbon-carbon unsaturation with at least one 1,3-dipolar grafting agent bearing at least one nitrile oxide dipole and at least one N-substituted or unsubstituted imidazolidinone functional group, in the presence of at least one organic phosphorus additive selected from the group consisting of phosphoric acid triesters, phosphonic acid esters, phosphinic acid esters, phosphine oxides and mixtures of these compounds, wherein the initial polymer is a diene elastomer, (b) recovering the masterbatch obtained in the previous step.

2. The process for the preparation of a masterbatch according to claim 1, wherein, Steps (a) and (b) are carried out at a temperature lower than or equal to 35°C.

3. Process for the preparation of a masterbatch according to any one of the preceding claims, further comprising a heat treatment step (a') after step (a).

4. The method for producing a masterbatch according to claim 1, wherein, The organic phosphorus additive corresponds to formula (I): wherein: - R1 is selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra groups, wherein Ra is a group selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl; - R2 is selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra groups, wherein Ra is a group selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl; and - R3 is selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra groups, wherein Ra is a group selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl.

5. The method for producing a masterbatch according to claim 1, wherein, The organic phosphorus additive corresponds to formula (I): wherein R1a, R2a, R3a, which can be identical or different, are selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl.

6. The method for producing a masterbatch according to claim 5, wherein, R1a, R2a, R3a, which can be identical or different, are selected from the group consisting of C1-C12 alkyl, C6-C12 aryl, (C1-C12)alkyl(C6-C12)aryl and (C6-C12)aryl(C1-C12)alkyl.

7. The method for producing a masterbatch according to claim 1, wherein, The organic phosphorus additive is selected from the group consisting of tris(ethylhexyl)phosphate, 2-ethylhexyldiphenyl phosphate, tri-n-octyl phosphate, tri-iso-butyl phosphate and mixtures thereof.

8. A masterbatch based on an initial polymer comprising at least one carbon-carbon unsaturation, at least one organic phosphorus additive selected from the group consisting of phosphoric acid triesters, phosphonates, phosphinates, phosphine oxides and mixtures of these compounds, and at least one 1,3-dipolar grafting agent bearing at least one nitrile oxide dipole and at least one N-substituted or unsubstituted imidazolidinone functional group, wherein, The initial polymer is a diene elastomer.

9. The masterbatch of claim 8, wherein, The organic phosphorus additive corresponds to formula (I): wherein: - R1 is selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl; - R2 is selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl; and - R3 is selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl and O-Ra groups, wherein Ra is a group selected from C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl.

10. The masterbatch according to any one of claims 8 and 9, wherein, The organophosphorous additive corresponds to formula (la): in which R1a, R2a, R3a, which can be identical or different, are selected from the group consisting of C1-C20 alkyl, C6-C20 aryl, (C1-C20)alkyl(C6-C20)aryl and (C6-C20)aryl(C1-C20)alkyl.

11. Composition comprising at least one masterbatch according to claim 10 or a masterbatch obtained according to the process as defined in any one of claims 1 to 7.

12. Rubber article comprising at least one composition according to claim 11.

13. Pneumatic or non-pneumatic tire comprising at least one composition as defined in claim 11.

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