Tire Compositions Containing Ethylene Copolymer-Based Functionalized Rubbers - Patent application

Abstract

Use of an ethylene copolymer to form a tire or tire tread compound, the ethylene copolymer being a copolymer comprising units derived from ethylene and at least one α-olefin monomer having 3 to 12 carbon atoms, preferably propylene, and optionally at least one unit derived from a non-conjugated diene, the ethylene copolymer being functionalized to have at least one functional group comprising at least one polar unit selected from a carboxylic acid group (or a salt thereof), an anhydride group, an epoxy group, a glycidyl ether group, or a combination thereof, the ethylene copolymer comprising 40 to 80% wt. of units derived from ethylene, preferably 44% wt. to 76% wt. of units derived from ethylene, and at least 20% wt. of units derived from one or one α-olefin monomer having 3 to 12 carbon atoms, preferably at least 15% wt. of units derived from propylene. Also provided are compositions comprising the ethylene copolymer and the conjugated diene polymer, methods of forming such compositions, and articles containing them.

Description

[Technical field]

[0001] Synthetic rubber is used in many different applications. [Background technology]

[0002] These are typically combined with one or more fillers to produce rubber compounds which are then molded into articles or combined with other ingredients to produce articles. A major use for synthetic rubbers includes tires or tire components such as tire treads. Typical conjugated diene rubbers are homopolymers of conjugated dienes or copolymers of at least one conjugated diene monomer are used for this purpose. Summary of the Invention [Problem to be solved by the invention]

[0003] There is a continuing need to improve the properties of tires, and in particular the properties of tire treads. It has now been found that rubbers based on ethylene copolymers can be advantageously used to advantageously form tires or tire treads. [Means for solving the problem]

[0004] Thus, in one aspect, there is provided the use of an ethylene copolymer for forming a tire or tire tread compound, wherein the ethylene copolymer is a copolymer comprising units derived from ethylene and at least one α-olefin monomer having from 3 to 12 carbon atoms, preferably propylene, and optionally having units derived from at least one non-conjugated diene, the ethylene copolymer being functionalized to have at least one functional group comprising at least one polar unit selected from a carboxylic acid group (or a salt thereof), an anhydride group, an epoxy group, a glycidyl ether group or a combination thereof, the ethylene copolymer comprising 40 to 80% wt. of units derived from ethylene, preferably 44% wt. to 76% wt. of units derived from ethylene, and at least 20% wt. of units derived from one or one α-olefin monomer having from 3 to 12 carbon atoms, preferably at least 15% wt. of units derived from propylene.

[0005] In another aspect, there is provided a composition comprising: (i) at least one functionalized ethylene copolymer; and (ii) at least one conjugated diene polymer, wherein the conjugated diene polymer is a homopolymer of a conjugated diene or a copolymer of at least one conjugated diene, and the conjugated diene is selected from the group consisting of butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenyl-1,3-butadiene, 1,3-hexadiene, preferably butadiene, and the conjugated diene polymer is unfunctionalized or functionalized.

[0006] In a further aspect, there is provided a method of forming a curable composition comprising combining an ethylene copolymer with a conjugated diene polymer and at least one curing agent capable of curing at least the conjugated diene polymer.

[0007] In yet another aspect, there is provided an article obtainable by a process comprising the step of curing a composition comprising (i) a functionalized ethylene copolymer and (ii) a conjugated diene polymer, wherein the process comprises at least one shaping step, wherein the shaping step can occur before, during, or after curing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the description that follows, the terms "comprising," "containing," "including," and "having" are intended to have a non-exclusive meaning and may or may not include the presence of any additional components, ingredients, steps or procedures.

[0009] In the following descriptions standards may be used. Unless otherwise stated, standards are used in the version that was valid on 1 March 2020. If there was no version valid on that date, for example because the standard had expired, reference is made to the version that was valid on the date closest to 1 March 2020.

[0010] In the following description, the amounts of components of a composition or polymer may be interchangeably indicated by "weight percent," "wt.%," or "wt %." The terms "weight percent," "wt.%," or "wt %," respectively, are based on the total weight of the composition or polymer, which is 100% unless otherwise specified.

[0011] The term "phr" means parts per hundred rubber, ie, weight percent of a total mass including rubber, which is taken as 100.

[0012] Ranges specified in this disclosure include and disclose all values ​​between the endpoints of the range and are intended to be inclusive of the endpoints unless otherwise specified.

[0013] The term "substituted" is used to describe a hydrocarbon-containing organic compound in which at least one hydrogen atom has been replaced with a chemical entity other than hydrogen. This chemical entity is referred to interchangeably herein as a "substituent," "residue," or "group." For example, the term "methyl group substituted with fluorine" refers to a fluorinated methyl group, and is exemplified by the group -CF 3 , -CHF 2 and -CH 2 F. The term "unsubstituted" is intended to refer to a hydrocarbon-containing organic compound in which none of its hydrogen atoms have been replaced. For example, the term "unsubstituted methyl residue" refers to a hydrocarbon-containing organic compound in which none of its hydrogen atoms have been replaced. 3 Refers to...

[0014] Ethylene Copolymer The functionalized ethylene copolymers can be prepared by methods known in the art. There is no particular restriction on the synthesis of the polymer, except that the polymer has at least one functional group. The ethylene copolymers can be prepared using polymerization catalysts such as Ziegler-Natta type catalysts, metallocene catalysts and post-metallocene catalysts. Preferably, the ethylene copolymers contain 40-80% wt. of units derived from ethylene, more preferably 44% wt.-76% wt. of units derived from ethylene. The polymers can be linear or branched.

[0015] The functional groups may be at a terminal position on the polymer or may be part of the polymer chain or part of a side chain. Preferably, the functional groups are part of the polymer chain or part of a side chain, and preferably the polymer contains multiple functional groups which may be the same or different.

[0016] Suitable functional groups include groups having or consisting of at least one polar unit selected from anhydride, epoxy group, glycidyl ether group, carboxylic acid group, and combinations thereof. Preferred polar units include carboxylic acid groups, including monocarboxylic acid groups and dicarboxylic acid groups, and anhydride groups. Preferred polar units include monocarboxylic acid groups or salts thereof, dicarboxylic acid groups or salts thereof, anhydride groups, or combinations thereof. In one embodiment of the present disclosure, the ethylene copolymer comprises 0.001 to 20% wt., preferably 0.001 to 10% wt., more preferably 0.3 to 5% wt. of polar units based on the total weight of the polymer.

[0017] At least one functional group may be introduced, for example, by grafting or copolymerization with an olefin functionalizing agent. Suitable olefin functionalizing agents contain at least one carbon-carbon double bond and at least one polar unit as described above. Olefin functionalizing agents also include polymerizable oligomers of up to 100 units derived from a monomer. Preferred olefin functionalizing agents include, but are not limited to, glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl ester, acrylic acid, methacrylic acid, vinyl acetate, cinnamic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, glutaconic anhydride, where one or more of the hydrocarbon groups have a substituent in place of a hydrogen atom, and the substituent is halogen, C 1 ~C 6 Alkyl, C 1 ~C 6 Alkyl halides, C 2 ~C 6 Alkenyl, C 2 ~C 6 Alkenyl halides, C 1 ~C 6 Hydroxyalkyl, C 2 ~C 6 Hydroxyalkenyl, C 1 ~C 6Alkyl ether or C 2 ~C 6 alkenyl ethers or polyethers, i.e., alkyl or alkenyl having one or more catenary oxygen ether atoms, and combinations thereof. Preferably, the ethylene copolymer comprises from 0.001 to 20% wt., preferably from 0.001 to 10% wt., more preferably from 0.3 to 5% wt., of functional groups derived from one or more olefin functionalizing agents, based on the total weight of the polymer.

[0018] Preferably, the ethylene copolymer has the formula (1), (2), or a combination thereof: [ka] The compound has one or more functional groups according to the formula:

[0019] In formula (1), R1 is a chemical bond or C 1 ~C 6 Alkyl, C 1 ~C 6 Alkyl halides, C 1 ~C 6 Hydroxyalkyl, C 1 ~C 6 R2 represents an alkyl ether or a polyether. 2 - group, one hydrogen atom of which is optionally halogen, C 1 ~C 6 Alkyl, C 1 ~C 6 Alkyl halides, C 1 ~C 6 Hydroxyalkyl, C 1 ~C 6 -CH, which may be substituted with alkyl ethers or polyethers 2 R3 represents a -CH 2 - group, one hydrogen atom of which is optionally halogen, C 1 ~C 6 Alkyl, C 1 ~C 6 Alkyl halides, C 1 ~C 6Hydroxyalkyl, C 1 ~C 6 -CH, which may be substituted with alkyl ethers or polyethers 2 -based. * indicates a bond to the polymer backbone. X represents H or a cation.

[0020] In a preferred embodiment of the present disclosure, the ethylene copolymer is represented by formulas (3)-(5): [ka] The compound includes one or more functional groups according to the formula:

[0021] Preferably, the ethylene copolymer comprises from 0.001 to 20% wt., preferably from 0.001 to 10% wt., more preferably from 0.3 to 5% wt. of functional groups, preferably according to formulae (1) to (5), based on the total weight of the polymer.

[0022] In one embodiment of the present disclosure, the functionalized polymer may be obtained, for example, by grafting, for example, by reactive extrusion with one or more olefin functionalizing agents. Such a process is described, for example, in US Patent Application Publication No. 2010 / 0113315 A1. The process may include heating the ethylene copolymer to a molten state, for example at a temperature in the range of 60° C. to 240° C., and grafting the olefin functionalizing agent to the polymer in an extruder or mixing device, preferably in the presence of a radical initiator. The olefin functionalizing agent and the radical initiator are separately co-fed to the molten polymer to effect the grafting. Radical initiators that may be used to graft the olefin functionalizing agent to the ethylene copolymer include, but are not limited to, peroxides, hydroperoxides, peresters, and azo compounds, and those that substantially thermally decompose to provide free radicals, preferably within the grafting temperature range and time. Representative examples of these radical initiators include azobutyronitrile, dicumyl peroxide, 2,5-dimethylhexane-2,5-bis-tert-butyl peroxide, 2,5-dimethoxylhex-3-yn-2,5-bis-tert-butyl peroxide, and di-tert-butyl peroxide. The initiator may be used in an amount of about 0.005% to about 1% by weight based on the weight of the reaction mixture.

[0023] Other methods known in the art for carrying out the reaction of ethylene copolymers with olefin functionalizing agents, such as halogenation reactions, thermal or "ene" reactions, or combinations thereof, can be used in place of the free radical grafting process. Such reactions are conveniently carried out in mineral oil or in bulk by heating the reactants under an inert atmosphere at temperatures between 60°C and 240°C to avoid the production of free radicals and oxidation by-products.

[0024] Functionalized polymers may also be obtained by using an olefin functionalizing agent as a comonomer during the polymerization reaction to produce an ethylene copolymer. The polymerization may be carried out to produce a random polymer or a block copolymer, where the olefin functionalizing agent may be used as one or more blocks, for example at the beginning, middle or end of the polymer. The olefin functionalizing agent may also be introduced as an oligomer, for example after it has been polymerized with itself, before, during or after the addition of the monomers to produce the ethylene copolymer.

[0025] Preferably, the ethylene copolymer comprises at least 5% by weight of units derived from one or more comonomers. The comonomers may be suitable olefin functionalizing agents as described above, such as (meth)acrylic acid and derivatives thereof, or they may be other comonomers that are not functionalized. Suitable non-functionalized comonomers include, but are not limited to, hydrocarbon alpha-olefins having 3 to 12 carbon atoms, preferably propylene.

[0026] In one embodiment, the copolymer has at least 20% by weight of units derived from one or more α-olefin comonomers, and preferably has at least 20% by weight of units derived from propylene.

[0027] In addition, the ethylene copolymer may contain units derived from one or more non-conjugated diene monomers that introduce unsaturation, i.e., -C=C- double bonds, into the polymer that may be available for the curing reaction. Suitable comonomers include non-conjugated diene monomers selected from polyenes containing at least two double bonds that are non-conjugated in a chain, ring, ring system, or combinations thereof. The polyenes may have endocyclic and / or exocyclic double bonds and may have no, the same or different types of substituents. The double bonds are at least separated by two carbon atoms. Substantially only one of the non-conjugated double bonds is converted by the polymerization catalyst. The non-conjugated dienes are preferably aliphatic, more preferably cycloaliphatic and aliphatic. Suitable non-conjugated dienes include aromatic polyenes, aliphatic polyenes and cycloaliphatic polyenes, preferably polyenes having 6 to 30 carbon atoms (C 6 ~C 30 -polyenes, more preferably C 6 ~C 30Specific examples of non-conjugated dienes include 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4-ethyl-1,4-hexadiene, 3,3-dimethyl-1,4-hexadiene, 5-methyl-1,4-heptadiene, 5-ethyl-1,4-heptadiene, 5-methyl-1,5-heptadiene, 6-methyl-1,5-heptadiene, 5-ethyl-1,5-heptadiene, 1,6-octadiene, 4-methyl-1,4-octadiene, 5-methyl-1,4-octadiene. , 4-ethyl-1,4-octadiene, 5-ethyl-1,4-octadiene, 5-methyl-1,5-octadiene, 6-methyl-1,5-octadiene, 5-ethyl-1,5-octadiene, 6-ethyl-1,5-octadiene, 1,6-octadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 6-ethyl-1,6-octadiene, 6-propyl-1,6-octadiene, 6-butyl-1,6-octadiene, 4-methyl-1,4-nonadiene, 5-methyl-1,4-nonadiene, 4-ethyl-1,4-nonadiene Diene, 5-ethyl-1,4-nonadiene, 5-methyl-1,5-nonadiene, 6-methyl-1,5-nonadiene, 5-ethyl-1,5-nonadiene, 6-ethyl-1,5-nonadiene, 6-methyl-1,6-nonadiene, 7-methyl-1,6-nonadiene, 6-ethyl-1,6-nonadiene, 7-ethyl-1,6-nonadiene, 7-methyl-1,7-nonadiene, 8-methyl-1,7-nonadiene, 7-ethyl-1,7-nonadiene, 5-methyl-1,4-decadiene, 5-ethyl-1,4-decadiene, 5-methyl-1,5-decadiene, 6-methyl-1,5-decadiene, 5-ethyl-1,5-decadiene, 6-ethyl-1,5-decadiene, 6-methyl-1,6-decadiene, 6-ethyl-1,6-decadiene, 7-methyl-1,6-decadiene, 7-ethyl-1,6-decadiene, 7-methyl-1,7-decadiene, 8-methyl-1,7-decadiene, 7-ethyl-1,7-decadiene, 8-ethyl-1,7-decadiene, 8-methyl-1,8-decadiene, 9-methyl-1,8-decadiene, 8-ethyl-1,8-decadiene, 1,5,9-decatriene, 6-methyl-1,Examples of the non-conjugated dienes include 6-undecadiene, 9-methyl-1,8-undecadiene, dicyclopentadiene, and mixtures thereof. Preferred non-conjugated dienes include alicyclic polyenes. The alicyclic dienes have at least one cyclic unit. In a preferred embodiment, the non-conjugated dienes are selected from polyenes having at least one endocyclic double bond and, optionally, at least one exocyclic double bond. Preferred examples include dicyclopentadiene, 5-methylene-2-norbornene, and 5-ethylidene-2-norbornene (ENB), with ENB being particularly preferred.

[0028] Examples of aromatic non-conjugated polyenes include vinylbenzene (including its isomers) and vinyl-isopropenylbenzene (including its isomers).

[0029] The copolymer may contain from 0.01 to 10% by weight of units derived from one or more non-conjugated diene monomers.

[0030] In one embodiment, the copolymer comprises units derived from ethylene and at least one or more α-olefins, and 0 to 10 wt % of one or more other comonomers, and in an embodiment, the copolymer does not comprise any non-conjugated diene monomers.

[0031] Preferably, the ethylene copolymer has a melt flow index (2.16 kg / 190° C.) of about 0.5 to 150 g / 10 min, preferably about 1 to about 120 g / 10 min.

[0032] In one embodiment, the ethylene copolymer has a molecular weight (Mw) from 10 to 300 kg / mol, or a number average molecular weight (Mn) from 10 to 100 kg / mol, or a combination thereof. In one embodiment, the ethylene copolymer has a ratio of Mw / Mn from about 1.2 to 10.

[0033] Suitable commercially available functionalized ethylene copolymers include, but are not limited to, KELTAN 2706R, KELTAN 0512R, or KELTAN 1519R, available from ARLANXEO Netherlands BV.

[0034] The functionalized ethylene copolymer is preferably used in combination with at least one conjugated diene polymer in a weight ratio of ethylene copolymer to conjugated diene polymer of 1:2 to 1:20, or 1:3 to 1:12. In one embodiment, the composition additionally comprises one or more NdBR.

[0035] Conjugated Diene Polymers The diene polymers according to the present disclosure can be functionalized or non-functionalized polymers.

[0036] The conjugated diene polymer according to the present disclosure is obtainable by a polymerization reaction comprising the polymerization of at least one conjugated diene as a monomer. Preferably, the diene polymer is a homopolymer or a copolymer of at least one conjugated diene, preferably selected from 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenyl-1,3-butadiene, 1,3-hexadiene. 1,3-butadiene and / or isoprene are particularly preferred.

[0037] In one embodiment of the present disclosure, the diene polymer is a polybutadiene homopolymer, more preferably a 1,3-butadiene homopolymer. In another embodiment of the present disclosure, the diene polymer is a 1,3-butadiene copolymer.

[0038] In another embodiment of the present disclosure, the diene polymer is a copolymer of a conjugated diene, preferably butadiene, where the copolymer comprises units derived from one or more of the above conjugated dienes and / or one or more vinyl aromatic monomers, and optionally one or more units derived from one or more other comonomers. Examples of vinyl aromatic monomers include, but are not limited to, styrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, para-t-butylstyrene, vinylnaphthalene, and combinations thereof. Styrene is particularly preferred.

[0039] The vinyl aromatic monomer also includes substituted vinyl aromatic monomers, in which one or more hydrogen atoms of the vinyl aromatic monomer are replaced with a heteroatom or a group having one or more heteroatoms, preferably selected from Si, N, O, H, Cl, F, Br, S, and combinations thereof. The substituted monomer also includes vinyl aromatic monomers having one or more functional groups having one or more heteroatoms or units containing at least one functional group having one or more heteroatoms. Preferably, the heteroatoms are selected from Si, N, O, H, Cl, F, Br, S, and combinations thereof. Examples of functional groups include, but are not limited to, hydroxy, thiol, thioether, ether, halogen carboxylic acid group or its salt, and combinations thereof. Such functionalized conjugated monomers are preferably copolymerized with one or more of the vinyl aromatic monomers described above.

[0040] In a preferred embodiment, the diene polymers according to the present disclosure contain repeat units derived from 1,3-butadiene and styrene.

[0041] Preferably, the polymers according to the present disclosure contain at least 50% by weight, preferably at least 60% by weight, of units derived from 1,3-butadiene, based on the weight of the polymer. In one embodiment of the present disclosure, the diene polymer contains at least 60% by weight, or at least 75% by weight, of units derived from 1,3-butadiene. In one embodiment, the polymers according to the present disclosure contain at least 75% or at least 95% by weight of units derived from one or more conjugated diene monomers.

[0042] In one embodiment of the present disclosure, the diene polymer contains 0 to 49 weight percent, or 0% to 40 weight percent, of units derived from one or more comonomers, based on the total weight of the polymer.

[0043] In one embodiment, the diene polymers of the present disclosure contain from 0 to 20 weight percent units derived from one or more conjugated dienes other than 1,3 butadiene.

[0044] In one embodiment, the diene polymer according to the present disclosure contains at least 50% by weight, preferably at least 60% by weight, of units derived from 1,3-butadiene, and at least 5% by weight, preferably up to 49% by weight, of units derived from one or more vinyl aromatic comonomers, preferably 5% to 40% by weight or 10% to 35% by weight, of units derived from one or more vinyl aromatic comonomers, preferably styrene, based on the weight of the polymer. Optionally, such polymers may contain 0 to 25% by weight of one or more other comonomers, provided that the total amount of monomers is adjusted so that the polymer still has a total weight of 100%. In one embodiment, the polymer according to the present disclosure contains 55% to 92% by weight of units derived from one or more conjugated diene monomers, and 5.8% to 45% by weight of units derived from vinyl aromatic comonomers.

[0045] Other conjugated dienes suitable as comonomers include, but are not limited to, myrcene, ocimene and / or farnesene. Conjugated dienes also include substituted conjugated dienes in which one or more hydrogen atoms of the diene are replaced by a group containing one or more heteroatoms selected from Si, N, O, H, Cl, F, Br, S and combinations thereof, or a functional group containing one or more heteroatoms, such as a functional group having one or more heteroatoms selected from Si, N, O, H, Cl, F, Br, S and combinations thereof. Examples of functional groups include, but are not limited to, hydroxy, thiol, thioether, ether, halogen, amine, silane, and units having one or more carboxylic acid groups or salts thereof, and combinations thereof. Such functionalized conjugated dienes are preferably copolymerized with one or more of the above conjugated dienes.

[0046] Suitable copolymerizable comonomers further include one or more α-olefins, such as ethene, propene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and combinations thereof. In one embodiment, the diene polymers according to the present disclosure contain 0 to 20 wt. % of units derived from one or more α-olefins.

[0047] Suitable comonomers also include one or more other copolymerizable comonomers that introduce functional groups other than the functional comonomers described above, including, but not limited to, crosslinking moieties, side group moieties, side groups, or functionalizing groups. In one embodiment of the present disclosure, the diene polymer contains 0% to 10% by weight or 0% to 5% by weight of units derived from one or more of such other comonomers. Such comonomers include, for example, divinylbenzene, trivinylbenzene, and divinylnaphthalene.

[0048] Combinations of one or more comonomers of the same chemical species as above may be used, as well as combinations of one or more comonomers from different chemical species. In one embodiment of the disclosure, the other comonomers are absent or the polymer contains less than 10% by weight, less than 5% by weight, or 1% by weight or less of units derived therefrom.

[0049] The diene polymer according to the present disclosure preferably has an average molecular weight (number average, Mn) of 10,000 to 2,000,000 g / mol, preferably 100,000 to 1,000,000 g / mol.

[0050] Preferably, the diene polymers according to the present disclosure have a glass transition temperature (Tg) of from about -110°C to about +20°C, preferably from about -110°C to about 0°C.

[0051] Preferably, the diene polymers according to the present disclosure have a Mooney viscosity [ML1+4(100° C.)] of from about 10 to about 200, preferably from about 30 to about 150 Mooney units.

[0052] The polymer typically has a dispersity of from about 1.03 to about 3.5.

[0053] The diene polymers can be prepared by methods known in the art. Preferably, the polymers are obtained by a process comprising anionic solution polymerization or polymerization using one or more coordination catalysts. The polymerization can be carried out in solution or gas phase. Coordination catalysts include Ziegler-Natta catalysts or single-component catalyst systems. Preferred coordination catalysts are based on Ni, Co, Ti, Zr, Nd, V, Cr, Mo, W or Fe.

[0054] In one embodiment, the conjugated diene polymer is not functionalized. In another embodiment, the conjugated diene polymer is functionalized. In one embodiment, the composition comprises a combination of at least one non-functionalized and at least one functionalized conjugated diene polymer.

[0055] Functionalized Conjugated Dienes Functionalized conjugated diene polymers can be prepared, for example, by a reaction involving the addition of at least one functionalizing agent to reactive polymer chains produced by polymerization of conjugated monomers, optionally followed by the addition of at least one further functionalizing agent as known in the art.

[0056] The diene polymer preferably comprises at least one silane or siloxane unit, preferably comprising from 1 to 20 silicon atoms in addition to carbon, hydrogen and optionally oxygen atoms, and is functionalized to form an end or side group by one or more suitable functionalizing agents comprising at least one functional group which may optionally further comprise one or more heteroatoms selected from N and S. Preferably, the functional group comprises at least one terminal unit comprising at least one group selected from the groups -COOX; -OX; -SX, -OR; -COOR, where X represents hydrogen or a cation and R represents C 1 ~C 20 -alkyl, preferably C 1 ~C 12 Represents alkyl.

[0057] In one embodiment of the present disclosure, the second functional group is accessible by adding a silicic acid compound or a cyclic urea, or an alkylene oxide, or a combination thereof, to the polymerization reaction. Preferably, the reaction product is treated with at least one terminal unit selected from -COOX; -OX; -SX, -OR; -COOR, where X represents hydrogen or a cation, and R is C 1 ~C 20 -alkyl, preferably C 1 ~C 12 - represents alkyl.

[0058] The silicic acid compound is preferably selected from divalent compounds having one Si atom per molecule, or divalent compounds which are open chain siloxanes having 2-12 silicon atoms per molecule, or cyclic siloxanes having 3-12 silicon atoms per molecule, or combinations thereof. The remaining valences of the silicon atoms are preferably bonded to R groups, where each R group is independently selected from the group consisting of hydrogen, alkylcycloalkyl, arylaralkyl, alkaryl groups having up to 20 carbon atoms, where these groups may optionally be hetero groups bonded to a carbon chain or a carbon ring selected from alkylamines and silylamines. The silicic acid compound has the formula: [ka] wherein R 5 and R 6 are the same or different and are each selected from H, a residue having 1 to 20 carbon atoms, preferably selected from an alkyl, cycloalkyl, aryl, alkaryl or aralkyl group, where the group may contain one or more heteroatoms, preferably O, N, S or Si, and is preferably selected from methyl. Specific examples include, but are not limited to, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane, as well as mixtures of different types of cyclosiloxanes.

[0059] The cyclic urea preferably has the general formula [ka] where R 1 C may be saturated or unsaturated and may be unsubstituted or substituted with one or more substituents. 1 ~C 6 -alkylene; unsubstituted or with one or more substituents, where the substituents are alkoxy and oxyalkyl groups having 1 to 6 carbon atoms, as well as -SiO(Rx) 3wherein each Rx independently represents an alkyl group having 1 to 6 carbon atoms; 6 ~C 11 arylene. Preferably, R 1 is C 1 ~C 3 alkylene, preferably unsubstituted, and more preferably R 1 Ha-CH 2 CH 2 -It is. 2 , R 3 are the same or different and represent saturated or unsaturated organic groups having 1 to 24 carbon atoms and optionally containing, in addition to hydrogen, one or more heteroatoms independently selected from the group consisting of O, N, S and Si. For example, R 2 and R 3 may be selected from the group consisting of: (i) -C is saturated or unsaturated, unsubstituted, mono- or polysubstituted 1 ~C 24 -alkyl; or (ii) -C is saturated or unsaturated, unsubstituted, mono- or polysubstituted 1 ~C 24 -heteroalkyl; (iii) an unsubstituted, mono- or polysubstituted 6- to 24-membered aryl, wherein the 6- to 24-membered aryl is optionally selected from the group consisting of -C 1 ~C 6 -Alkylene- or -C 1 ~C 6 -heteroalkylene-, which in each case is saturated or unsaturated, unsubstituted, mono- or polysubstituted; (iv) unsubstituted, monosubstituted or polysubstituted 5- to 24-membered heteroaryl; wherein the 5- to 24-membered heteroaryl is optionally selected from the group consisting of -C 1 ~C 6 -Alkylene- or -C 1 ~C 6 -heteroalkylene-, which in each case is saturated or unsaturated, unsubstituted, mono- or polysubstituted; (v) a saturated or unsaturated, unsubstituted, mono- or polysubstituted 3- to 24-membered cycloalkyl; wherein the 3- to 24-membered cycloalkyl is optionally selected from the group consisting of -C 1 ~C 6 -Alkylene- or -C 1 ~C 6 -heteroalkylene-, which in each case is saturated or unsaturated, unsubstituted, mono- or polysubstituted; and (vi) a saturated or unsaturated, unsubstituted, mono- or polysubstituted 3- to 24-membered heterocycloalkyl; wherein the 3- to 24-membered heterocycloalkyl is optionally selected from the group consisting of -C 1 ~C 6 -Alkylene- or -C 1 ~C 6 -heteroalkylene-, which in each case is saturated or unsaturated, unsubstituted, mono- or poly-substituted, where in each case "mono- or poly-substituted" refers to C which may be saturated or unsaturated. 1 ~C 18 -Alkyl and tri(C 1 ~C 18 -) alkylsilyl and substituted with one or more substituents selected independently from each other. Preferably, R 2 and R 3 is C1-C6 alkyl, more preferably -CH 3 or -CH 2 CH 3 is selected from.

[0060] The reaction products include, for example, -COOX; -OX; -SX, -OR; -COOR (where X represents hydrogen or a cation and R is C 1 ~C 20 -alkyl, preferably C 1 ~C 12The polymer may be treated with a suitable agent to introduce terminal units such as at least one terminal unit selected from the group consisting of aryl, aryl, aryl- ... Functionalization of polymers is described, for example, in International Publication No. WO 2021 / 009154; U.S. Pat. No. 3,242,129, U.S. Pat. No. 4,020,036, U.S. Pat. No. 4,465,809, U.S. Patent Application Publication No. 2016 / 0075809 A1, and U.S. Patent Application Publication No. 2016 / 0083495 A1, and International Publication No. WO 2021 / 009154, all of which are incorporated by reference herein.

[0061] In one embodiment of the present disclosure, the composition is provided with at least 90% by weight, preferably at least 95% by weight, based on the total weight of the composition of the ethylene copolymer and the conjugated diene polymer.Preferably, such composition is a solid composition.Such a composition can be obtained, for example, by mixing solid polymers (dry blending) or by adding another polymer to a polymer solution, preferably a reaction mixture, and removing the solvent (wet blending).

[0062] The conjugated diene polymer may be oil extended and may contain up to 100 parts of extender oil per 100 parts of polymer. When the polymer is oil extended, i.e., the polymer is combined with one or more extender oils before or during post-processing of the polymer, typically before solvent removal, the composition also contains extender oil as part of the oil-extended polymer. Polymers may be oil extended if they have a high molecular weight. Polymers with high molecular weight have a high Mooney viscosity. If the Mooney viscosity is too high, processing the polymer to form a rubber compound may be difficult or uneconomical. The Mooney viscosity of the polymer can be reduced by adding an extender oil before or during post-processing of the polymer to provide an oil-extended polymer. A typical amount of extender oil is 10 to 100 parts per 100 parts of polymer. The extender oil includes oils known and used in the oil extension of diene rubber, such as TDAE (treated distillate aromatic extract), MES (mild extract solvate), RAE (residual aromatic extract), TRAE (treated residual aromatic extract), naphthenic oil, paraffinic oil and their hydrogenated oils (including oils obtained from plant-based materials containing terpenes), etc. These are preferably added to the reaction mixture before or during the solvent removal.

[0063] Rubber Compounds Compositions including the polymers of the present disclosure can be used to form rubber compounds by a process including combining the polymer with one or more fillers and / or one or more crosslinking agents for crosslinking at least the conjugated diene polymer. The resulting tire or tire component will typically contain the conjugated diene polymer or rubber compound in vulcanized form.

[0064] Thus, in one aspect of the present disclosure, there is provided a process for forming a rubber compound, comprising combining a polymer composition according to the present disclosure with at least one filler, at least one curative capable of curing at least a diene polymer, or a combination thereof.

[0065] The one or more fillers include both active and inactive fillers. Conventional fillers include silica and, preferably, one or more carbon-based fillers, such as carbon black.

[0066] Specific examples of suitable fillers are described in U.S. Patent Application Publication No. 2016 / 0075809A1 (

[0061] to

[0074] ), which is incorporated herein by reference. Preferably, the rubber compounds of the present disclosure contain one or more carbon blacks as fillers.

[0067] The filler may be used in an amount ranging from 10 to 500, preferably 20 to 200 parts by weight, based on 100 parts by weight of rubber.

[0068] The rubber compounds and vulcanizable rubber compounds may further contain one or more additional rubbers. Such additional rubbers include, for example, natural and synthetic rubbers, and in particular one or more polybutadiene rubbers, preferably Nd-catalyzed polybutadienes, also referred to as NdBR. When present, they may be used in an amount ranging from 0.5 to 95% by weight, preferably from 10 to 80% by weight, based on the total amount of rubber in the composition. Examples of suitable synthetic rubbers include those described in US Patent Application Publication No. 2016 / 0075809A1 (

[0060] ), which is incorporated herein by reference.

[0069] The composition may further include one or more rubber additives. Rubber additives are ingredients that can improve the processing properties of rubber compositions, promote or accelerate crosslinking, improve the physical properties of vulcanizates produced from rubber, improve the interaction between rubber and fillers, or help bond rubber to fillers. Rubber auxiliaries include crosslinkers such as sulfur or sulfur donor compounds, reaction accelerators, antioxidants, heat stabilizers, light stabilizers, ozone stabilizers, processing aids, plasticizers, tackifiers, expansion agents, dyes, pigments, waxes, extenders, organic acids, silanes, retarders, metal oxides, extender oils such as DAE (distillate aromatic extracts)-, TDAE (treated distillate aromatic extracts)-, MES (mild extract solvates)-, RAE (residual aromatic extracts)-, TRAE (treated residual aromatic extracts)-, naphthenic and heavy naphthenic oils, and activators. The total amount of rubber additives, including curatives such as sulfur or sulfur donating compounds, can range from 1 to 300 parts by weight, preferably 5 to 150 parts by weight, based on 100 parts by weight of total rubber in the composition.

[0070] The rubber composition can be prepared in conventional processing equipment for forming and processing (vulcanizable) rubber compounds, and includes rollers, kneaders, internal mixers or mixing extruders. The rubber composition can be produced in a single or multi-stage process, with 2-3 mixing stages being preferred. Crosslinking agents, e.g. sulfur, and accelerators can be added in separate mixing stages, e.g. rollers, with temperatures in the range of 30°C to 90°C being preferred. Crosslinking agents, e.g. sulfur, and accelerators are preferably added in the final mixing stage.

[0071] Purpose Preferably, the ethylene copolymers provided herein, more preferably the compositions comprising at least one ethylene copolymer and at least one conjugated diene polymer, are used to form tires or tire treads, preferably as a component of a curable composition.

[0072] Thus, in one aspect, an article is provided that is obtained from the curing of the composition comprising the polymer according to the present disclosure. The process may include at least one molding step, where molding may be performed before, during or after curing. Suitable articles include tires, preferably tire treads. However, the composition containing the polymer provided herein is also suitable for the manufacture of articles, in particular molded articles, such as cable sheaths, hoses, drive belts, conveyor bellways, roll linings, shoe soles, seal rings and damping parts.

[0073] The following examples are provided to further illustrate the present disclosure, but are not intended to limit the disclosure to the embodiments described in these examples.

[0074] method molecular weight The molecular weights of the polymers (Mw and Mn, weight-average and number-average molecular weight moments, respectively) were determined by gel permeation chromatography. Universal calibration of the system was performed using polyethylene (PE) standards. A Polymer Char GPC from Polymer Characterisation SAValencia, Spain was used. The Size Exclusion Chromatograph was equipped with an online viscometer (Polymer Char V-400 viscometer), an online infrared detector (IR5 MCT), 3 AGILENT PL OLEXIS columns (7.5 x 300 mm) and a Polymer Char autosampler.

[0075] The polymer samples were weighed into the vials of a PolymerChar autosampler (within the concentration range of 0.3-1.3 mg / ml). In the autosampler, the vials were automatically filled with the solvent (1,2,4-trichlorobenzene, TCB) stabilized with 1 g / l di-tert-butyl-paracresol (DBPC). The samples were kept in a high temperature oven (160 °C) for 4 hours. After this dissolution time, the samples were automatically filtered by an in-line filter and then injected into the column. The chromatographic system was operated at 160 °C. The flow rate of the TCB eluent was 1.0 ml / min. The chromatograph was equipped with a built-in online infrared detector (IR5 MCT) for concentration and a built-in PolymerChar online viscometer.

[0076] Properties of vulcanized compounds The loss factor tan δ was measured at 0° C. and 60° C. to determine the temperature-dependent dynamic mechanical properties. An EPLEXOR device (Eplexor 500 N) from GABO was used for this purpose. The measurements were carried out in the temperature range from -100° C. to 100° C. according to DIN 53513 at 10 Hz on Ares strips.

[0077] The rebound resilience at 60° C. was determined in accordance with DIN 53512.

[0078] Tensile strength tests were carried out in accordance with DIN 53504 on vulcanized S2 specimens.

[0079] The elastic properties were determined according to DIN 53513-1990. An elastomer test system (MTS Systems GmbH, 831 Elastomer Test System) was used. Measurements were performed in double shear mode with no static prestrain in the shear direction, oscillation around zero on cylindrical samples (two samples of 20 x 6 mm each, precompressed to a thickness of 5 mm), and a measurement frequency of 10 Hz within the strain range of 0.1 to 40%. This method was used to obtain the following properties: G'(0.5%): dynamic modulus at 0.5% amplitude sweep, G'(15%): dynamic modulus at 15% amplitude sweep, G'=G'(0.5%)-G'(15%): difference in dynamic modulus at 0.5% for 15% amplitude sweep, tan δ(max): maximum loss factor (G” / G') over the entire measurement range at 60℃.

[0080] The difference G'(0.5%)-G'(15%) is an indicator of the Payne effect of the mixture: the lower this value, the better the filler distribution in the mixture, the better the rubber-filler interaction, and the lower the risk of phase separation. EXAMPLES

[0081] Three different non-conjugated diene polymers (Polymers 1, 2 and 3) were mixed with different conjugated diene rubbers in a tire tread formulation and subjected to a curing step. The tire tread compositions are summarized in Table 1. Polymer 1 was a non-functionalized EPM rubber (49 wt.% C2, Mn 57 kg / mol, Mw 125 kg / mol), Polymer 2 was a non-functionalized EPDM rubber (7.8 wt.% ENB, 49 wt.% C2, Mn 45 kg / mol, Mw 170 kg / mol), and Polymer 3 was a functionalized EPM (1.9% wt. grafted maleic anhydride, 49 wt.% C2, Mn 50 kg / mol, Mw 100 kg / mol, MFI 4.5 g / 10 min). The conjugated diene rubbers were non-functionalized polybutadiene (BR), non-functionalized styrene-butadiene copolymer (SSBR), and styrene-butadiene copolymer with terminal polar siloxane-units that were functionalized and contained end groups (FxSSBR).

[0082] [Table 1]

[0083] In the first step, the following ingredients were mixed in a 1.5 L kneader. The polymer was added first, and after 30 seconds of mixing, 2 / 3 of the silica, 2 / 3 of the silane, the stabilizer and stearic acid were added. After 90 seconds, the remainder of the silica and silane were added along with the oil and carbon black. After 150 seconds of mixing, zinc oxide was added, and after 210 seconds of mixing, the mixer was heated to 150° C. and held at this temperature for 3 minutes. The resulting mixture was then kneaded on a roller mill (3×l / r cross-cut and folded, 3×end rolls (4 mm)). The resulting mixture was allowed to stand for 24 hours, then added to a 1.5 L kneader at 150° C. and mixed at 150° C. for 3 minutes. The resulting mixture was again kneaded on a roller mill (3×r / l cross-cut and folded (4 mm)). The sulfur and accelerators are added to the roller mill and mixing is continued (3xr / l cross cut and fold, 5xend rolls (4mm)).The tire tread composition is then subjected to curing at 160°C for 1560 seconds.

[0084] [Table 2]

[0085] These results show that the addition of functionalized ethylene copolymer (Polymer 3) to butadiene or styrene-butadiene polymers results in better filler dispersion (Payne effect values ​​(G'(0.5%)-G'(15%) are reduced) and improved rolling resistance indices (tan δ and max tan δ at 60°C are reduced, and rebound resilience at 60°C is increased).

Claims

1. 1. Use of an ethylene copolymer for forming a tire or tire tread compound, said ethylene copolymer being a copolymer comprising units derived from ethylene and at least one α-olefin monomer having from 3 to 12 carbon atoms, preferably propylene, and optionally having units derived from at least one non-conjugated diene, said ethylene copolymer being functionalized to have at least one functional group comprising at least one polar unit selected from a carboxylic acid group (or a salt thereof), an anhydride group, an epoxy group, a glycidyl ether group or a combination thereof, said ethylene copolymer comprising 40 to 80% wt. of units derived from ethylene, preferably 44% wt. to 76% wt. of units derived from ethylene, and at least 20% wt. of units derived from one or one α-olefin monomer having from 3 to 12 carbon atoms, preferably at least 15% wt. of units derived from propylene.

2. 2. The use according to claim 1, wherein the ethylene copolymer comprises from 0.001 to 20 wt. %, preferably from 0.001 to 10 wt. %, and more preferably from 0.3 to 5 wt. %, of said one or more polar units, based on the weight of the polymer.

3. 3. The use according to claim 1 or 2, wherein the polar unit is selected from a monocarboxylic acid group or a salt thereof, a dicarboxylic acid group or a salt thereof, an anhydride group, or a combination thereof.

4. The one or more functional groups of the ethylene copolymer are derived from at least one olefin functionalizing agent selected from glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl ester, acrylic acid, methacrylic acid, vinyl acetate, cinnamic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, glutaconic anhydride, including salts and derivatives thereof, wherein the one or more hydrocarbon groups have a substituent in place of a hydrogen atom, and the substituent is selected from the group consisting of halogen, C １ ~C ６ Alkyl, C １ ~C ６ Alkyl halides, C ２ ~C ６ Alkenyl, C ２ ~C ６ Alkenyl halide, C １ ~C ６ Hydroxyalkyl, C ２ ~C ６ Hydroxyalkenyl, C １ ~C ６ Alkyl ether or C ２ ~C ６ The use according to any one of claims 1 to 3, selected from alkenyl ethers or polyethers, ie alkyl or alkenyl having one or more catenary oxygen ether atoms, and combinations thereof.

5. The ethylene copolymer may have the formula (1), (2), or a combination thereof: 【Chemistry 1】 (wherein, in formula (1), R1 is a chemical bond or １ ~C ６ Alkyl, C １ ~C ６ Alkyl halides, C １ ~C ６ Hydroxyalkyl, C １ ~C ６ represents an alkyl ether or polyether, and R2 is -CH ２ - group, one hydrogen atom of which is optionally halogen, C １ ~C ６ Alkyl, C １ ~C ６ Alkyl halides, C １ ~C ６ Hydroxyalkyl, C １ ~C ６ -CH, which may be substituted with alkyl ether or polyether ２ - group, and R3 represents -CH ２ - group, one hydrogen atom of which is optionally halogen, C １ ~C ６ Alkyl, C １ ~C ６ Alkyl halides, C １ ~C ６ Hydroxyalkyl, C １ ~C ６ -CH, which may be substituted with alkyl ether or polyether ２ - group, and ＊ represents a bond to the polymer backbone, and X represents H or a cation. The use according to any one of claims 1 to 4, wherein the compound has one or more functional groups according to

6. The use according to any one of claims 1 to 5, wherein the ethylene copolymer has a melt flow index at 190°C and 2.16 kg load of 0.5 to 110 g / 10 min.

7. 7. The use according to any one of claims 1 to 6, wherein the functional groups of the ethylene copolymer are accessible by grafting at least one olefin functionalizing agent onto the ethylene copolymer to provide an ethylene copolymer as defined in any one of claims 1 to 6, or by copolymerizing at least one functionalizing agent during the polymerization reaction to provide an ethylene copolymer as defined in any one of claims 1 to 6, or by a combination thereof.

8. A composition comprising (i) at least one functionalized ethylene copolymer as defined in any one of claims 1 to 7, and (ii) at least one conjugated diene polymer, said conjugated diene polymer being a homopolymer of a conjugated diene or a copolymer of at least one conjugated diene, and said conjugated diene being selected from the group consisting of butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenyl-1,3-butadiene, 1,3-hexadiene, preferably butadiene, and said conjugated diene polymer being non-functionalized or functionalized.

9. 9. The composition of claim 8, wherein the conjugated diene polymer is a butadiene homopolymer or a butadiene copolymer comprising units derived from butadiene and at least one other conjugated diene or at least one vinyl aromatic comonomer or combinations thereof, and the vinyl aromatic comonomer is selected from styrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, para-t-butylstyrene, vinylnaphthalene, and combinations thereof, and preferably selected from styrene.

10. 10. The composition of claim 8 or 9, wherein the conjugated diene polymer is functionalized and comprises at least one functional group comprising at least one siloxane unit, preferably comprising 1 to 20 silicon atoms, and optionally comprising at least one heteroatom selected from N and S.

11. The conjugated diene polymer comprises the groups -COOX; -OX; -SX, -OR; -COOR, where X represents hydrogen or a cation and R represents C １ ~C ２０ - alkyl, preferably C １ ~C １２ 11. The composition according to claim 8, wherein the polymer is functionalized with at least one functional group comprising at least one terminal unit comprising at least one group selected from the group consisting of -alkyl.

12. The composition according to any one of claims 8 to 11, wherein the weight ratio of the ethylene copolymer and the conjugated diene polymer is from 1:2 to 1:

20.

13. A method of forming a curable composition comprising combining an ethylene copolymer as defined in any one of claims 1 to 7 with a conjugated diene polymer and at least one curing agent capable of curing at least said conjugated diene polymer.

14. 13. An article obtainable by a process comprising a step of curing a composition comprising the composition according to any one of claims 8 to 12, said process comprising at least one shaping step, said shaping step may be performed before, during or after said curing.

15. 15. The article according to claim 14, selected from a tire, preferably a tire tread of a tire.

Images