WO2008091847A1 - Polymeric compositions, methods of making the same, and articles prepared from the same - Google Patents

Abstract

The invention provides a composition comprising at least one polyisoprene, and at least one EAODM polymer, and where the at least one EAODM has a Mooney viscosity, ML(1+4) at 125°C, greater than 60. The invention also provides for methods of making the same, and for articles prepared from the same.

Description

POLYMERIC COMPOSITIONS, METHODS OF MAKING THE SAME, AND ARTICLES PREPARED FROM THE SAME

REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application No. 60/897,159, filed on January 24, 2007, and fully incorporated herein by reference.

FIELD OF INVENTION

This invention relates to polyolefin compositions containing a polyisoprene and an ethylene/α-olefϊn/diene modified polymer, to methods of making the same, and to articles prepared from the same.

BACKGROUND OF THE INVENTION

Natural rubber (NR) is used in polymeric formulations for the manufacture of tires, belts, and other articles requiring the elasticity, the fatigue resistance, the tear resistance, and the resilience of Natural Rubber (NR). However, the rising costs of natural rubber-based polymers has driven the search for polymer substitutes that can replace all, or a portion of, the NR in a polymeric formulation. Polyolefins, such as ethylene-propylene-diene modified (EPDM) polymers are typically cheaper than natural rubber, and exhibit better oxidative and thermal aging resistance. However, products formed from blends of low molecular weight EPDM polymers with natural rubber typically do not have tear resistance, fatigue resistance and abrasion resistance comparable to products based on pure NR.

U.S. Patent 6,693,145 discloses vulcanized ethylene-propylene-diene (EPDM) rubbers that are use in dynamic applications, as a replacement for natural rubber parts. This patent discloses that the ethylene-propylene-diene rubbers exhibit excellent thermal and oxidative resistance, while displaying tensile strength and dynamic fatigue resistance comparable to similar compounds based on natural rubber. The ethylene-propylene-diene rubbers comprise a high molecular weight EPDM, a processing oil, a carbon black, and a cure system containing sulfur, tetramethylthiuram-disulfide and 2-mercaptobenzothiazole. International Publication Number WO 02/083433 discloses a tire comprising at least one component made of crosslinked elastomeric material, in which said component includes an elastomeric composition comprising: a) at least one diene elastomeric polymer, b) at least one copolymer of ethylene with at least one aliphatic α-olefm, and optionally a polyene. The copolymer is characterized by a molecular weight distribution (MWD) index of less than 5, preferably between 1.5 and 3.5, and by a melting enthalpy (ΔaHm) of not less than 30 J/g.

European Patent Application No. EP 0 775 719 A2 discloses a process for preparing a polymeric composition, comprising combining at least two granular elastomers, wherein each elastomer has particles in size of about 5 mm or smaller, into a granular purblind; optionally adding one or more additives, such as fillers, oils, processing aids, anti-degradants, and the like; and masticating the purblind and optional additives, with at least one vulcanizing agent, to produce a vulcanizable elastomeric compound. The vulcanizable elastomeric compound finds particular utility in tire sidewalls and pneumatic tires. This application discloses the use of granular EPDM in a blend with other granular elastomers, such as polyisoprene, styrene/butadiene copolymers, and polybutadiene to improve mixing behavior of the blend.

U.S. Publication 2005/0137338 and U.S. Publication 2006/0074207, each discloses a neodymium catalyst system, which can be used in the polymerization of isoprene monomer into synthetic polyisoprene rubber having an extremely high cis- microstructure content and high stereo regularity. This polyisoprene rubber will crystallize under strain, and can be compounded into rubber formulations in a manner similar to natural rubber. This invention more specifically discloses a process for the synthesis of polyisoprene rubber, which comprises polymerizing isoprene monomer in the presence of a neodymium catalyst system.

U.S. Publication 2006/0106149 discloses the preparation of a natural rubber- rich composition and tire, with tread thereof, and where a portion of the natural rubber is replaced with a specialized trans- 1 ,4-styrene/butadiene copolymer rubber.

U.S. Publication 2005/0245688 is directed to a tire with a tread of a natural rubber-rich rubber composition. A partial replacement of the natural rubber in the tire tread is accomplished by an inclusion of a relatively low Mooney viscosity, specialized trans- 1,4-polybutadiene. The tire tread rubber composition is comprised of a blend of the specialized trans- 1,4-polybutadiene polymer and cis-1,4- polyisoprene natural rubber, optionally together with at least one additional diene- based elastomer, in which the natural rubber remains a major portion of the elastomers in the tread rubber composition.

U.S. Patent 5,988,248 discloses a pneumatic rubber tire having a rubber sidewall, with at least a portion of its outer surface being composed of white rubber devoid of carbon black reinforcement, and composed of an elastomer composition which contains a combination of trans- 1,4-polybutadiene and synthetic cis-1,4- polyisoprene rubber, and an exclusion of, or substantial exclusion of, natural cis-1,4- polyisoprene rubber.

U.S. Patent 6,988,523 discloses a pneumatic tire which is comprised of a generally toroidal-shaped carcass, with an outer circumferential tread, two spaced beads, at least one ply extending from bead to bead, and sidewalls extending radially from, and connecting, said tread to said beads. The tread is comprised of the following: (a) about 60 phr to about 90 phr of a cis- 1,4-polybutadiene rubber, which has a glass transition temperature which is within the range of about -104⁰C to about - 80⁰C, (b) about 10 phr to about 40 phr of at least one additional rubbery polymer, selected from the group consisting of polyisoprene rubber, polybutadiene rubber, isoprene-butadiene rubber, and styrene-isoprene-butadiene rubber, and where the additional rubbery polymer has a glass transition temperature which is within the range of about -30⁰C to about -10⁰C, and (c) about 20 phr to about 60 phr of carbon black.

European Application No. EP 1514899A1 discloses a tire with a sidewall insert and/or apex of a rubber composition, which contains a high vinyl polybutadiene elastomer, and characterized in that said rubber composition for said apex and/or sidewall insert is comprised of, based upon parts by weight of an ingredient per 100 parts by weight elastomer (phr), the following: (a) 50 to 80 phr of at least one diene based elastomer, (b) 20 to 50 phr of high vinyl polybutadiene elastomer, which has a vinyl 1,2-content in a range of 40 to 80 percent; (c) 20 to 100 phr of at least one reinforcing particulate filler, selected from carbon black, aggregates of synthetic amorphous silica, and silica-containing carbon having domains of silica on its surface, and, optionally, (d) a coupling agent having a moiety reactive with hydroxyl groups contained on the surface of said amorphous silica, and said silica domains on the surface of said silica-containing carbon black, and another moiety interactive with at least one of said elastomers.

European Application No. EP 1593528A1 discloses a tire with a tread of a natural rubber-rich composition. This reference discloses a partial replacement of the natural rubber in the tire tread with a relatively low Mooney viscosity specialized trans- 1,4-polybutadiene. The tire tread rubber composition is comprised of a blend of the specialized trans- 1,4-polybutadiene polymer and cis-l,4-polyisoprene natural rubber, optionally together with at least one additional diene-based elastomer, in which the natural rubber remains a major portion of the elastomers in the tread rubber composition.

European Application No. EP 1593529A1 discloses a natural rubber-rich composition, and tire with a tread thereof. This reference discloses a partial replacement of the natural rubber with a specialized trans- 1 ,4-styrene/butadiene copolymer rubber, characterized as having a combination of bound styrene content and microstructure limitations. The tire tread rubber composition is comprised of a blend of the specialized trans- 1 ,4-styrene/butadiene rubber and cis-l,4-polyisoprene natural rubber, optionally together with at least one additional diene-based elastomer, in which the natural rubber remains a major portion of the elastomers in the tread rubber composition.

U.S. Patent 7,026,387 discloses a vulcanizable rubber composition which can be used for the manufacture of tires; a process for the preparation of this composition; and a tire, the tread of which comprises such a composition. The composition is disclosed as having improved hysteresis and physical properties in the vulcanized state, while retaining satisfactory processing properties. The rubber composition comprises a reinforcing white filler, and at least one diene block polymer, which is intended to interact with said reinforcing white filler, and which comprises, on at least one of its chain ends, a polysiloxane block, which ends in a trialkylsilyl group.

U.S. Publication 2005/0261453 discloses branched synthetic polyisoprenes having a macrostructure and a microstructure very similar to those of natural rubber. U.S. Publication 2006/0009568 discloses a crosslinkable or crosslinked rubber composition containing a diene elastomer having a mass content of cyclic vinyl units of greater than 15 percent. The composition may be used to form a tire tread. The composition contains a linear or branched diene elastomer, derived from at least one conjugated diene, and a reinforcing filler. The elastomer has cyclic vinyl units according to a mass content of greater than, or equal to, 15 percent, and a number- average molecular weight of from 30,000 to 350,000 g/mol.

U.S. Publication 2006/0124215 discloses a tire for heavy vehicle of the agricultural or construction type, and formed from one or more diene elastomers.

European Patent EP 1062105Bl discloses a tire having improved tear strength, and formed from a composition containing at least one component comprising a vulcanized elastomer and a polyolefm additive. Polyolefins preferably include polypropylenes.

European Patent EP 109971 IBl discloses a modified conjugated diene polymer that has a content of cis-l,4-bond of not less than 85 percent, and a ratio of weight average molecular weight to number average molecular weight of not more than 4. This reference also discloses a rubber composition comprising the modified conjugated diene polymer.

European Application EP 1640412Al discloses a rubber composition containing a polyisoprene rubber having a very high cis-l,4-bond content, and having an excellent balance between dynamic properties and processability. More particularly, this reference discloses a rubber composition comprising the following: (a) a synthetic polyisoprene rubber having a cis-l,4-bond content of not less than 99.0 percent, a 3,4-bond content of not more than 0.5 percent, and a Mooney viscosity ML1+4 (100⁰C) of 20-110, and (b) a natural rubber.

U.S. Patent 4,433,107 discloses a rubber composition having improved cut growth resistance, processability and dimensional stability, and which comprises not less than 20 parts by weight of polyisoprene having a melting point of not less than 10⁰C, and a content of cis-1,4 bond of not less than 88 percent, and the balance of at least one diene rubber.

European Application No. EP1612034A1 discloses a method for forming a green tread rubber (TG), comprised of a cap rubber layer (Gl), which outer surface forms a tread surface, and a base rubber layer (G2) that adjoins the same inside thereof, in the radial direction. A cap rubber has a rubber component of styrene/butadiene rubber, or a mixed rubber of natural rubber and butadiene rubber is used as the cap rubber layer (Gl).

U.S. Publication 2006/0102269 discloses a pneumatic tire capable of achieving both reduced rolling resistance and enhanced durability, and a method of producing the same. The pneumatic tire includes a reinforcement layer, formed of a steel cord coated with coating rubber, including at least one of a carcass, a bead reinforcement layer, a side reinforcement layer and a belt. The coating rubber is formed of a rubber compound containing 100 parts by mass of diene rubber, 30 to 80 parts by mass of silica having a nitrogen surface area of at least 70 m²/g, and at most 150 m²/g, and one to 15 parts by mass of a silane coupling agent, and organic acid cobalt salt.

U.S. Patent 7,040,369 discloses a pneumatic radial tire, in which rolling resistance is reduced and durability is improved, without losing toe-chip resistance, when assembling the rim. More specifically, a pneumatic radial tire having a chafer, comprising a rubber composition having complex modulus of 9 to 13 MPa, measured under conditions of temperature of 70⁰C, frequency of 10 Hz, and dynamic strain of ± 2 percent, loss tangent of 0.08 to 0.11, and tensile elongation at break of at least 230 percent.

There is a need for polymeric formulations that contain less natural rubber and more cost saving polyolefm(s), and which can be used to form articles with good tear resistance and abrasion resistance. There is a further need for a NR/polyolefm formulation that can be used to form products with improved oxidation resistance, improved thermal aging resistance, and/or improved rolling resistance, while maintaining tear resistance and/or abrasion resistance similar to that of products formed from conventional rubber formulations. Some of these needs and other have been met by the following invention.

SUMMARY OF THE INVENTION

The invention provides a composition comprising the following: a) at least one polyisoprene, and b) at least one ethylene/α-olefϊn/diene (EAODM) interpolymer, and wherein the at least one EAODM has a Mooney viscosity, ML(I +4) at 125⁰C, greater than 60. Preferably, the at least one EAODM is an EPDM interpolymer. Mooney viscosity is that of the neat interpolymer (or calculated viscosity of neat polymer for polymers that contain a filler, such as carbon black, and/or an oil).

The invention also provides a method of making a polymeric formulation, said method comprising mixing a composition comprising at least one polyisoprene, at least one EAODM polymer, and optionally, at least one oil and/or filler, and wherein the at least one EAODM has a Mooney viscosity, ML(l+4) at 125⁰C, greater than 60. Preferably, the at least one EAODM is an EPDM interpolymer. Mooney viscosity is that of the neat interpolymer (or calculated viscosity of neat polymer for polymers that contain a filler, such as carbon black, and/or an oil).

DETAILED DESCRIPTION OF THE INVENTION

EPDM polymers of low molecular weight have been added to rubber formulations to improve heat resistance and oxidative resistance of the formulation. However, such formulations have reduced abrasion resistance and reduced fatigue and tear resistance.

It has been found that, if the weight average molecular weight (M _w) of EPDM (as indicated by Mooney Viscosity) is high enough, such an EPDM can be used in a formulation with a natural rubber, and optionally a polybutadiene, to form products with good tear resistance and/or good abrasion resistance, each comparable to conventional NR/BR blends.

It has also been found that, if the weight average molecular weight (Mw) of EPDM is high enough, such an EPDM can be used as partial replacement of the natural rubber (NR) to form rubber compounds with similar tensile properties, maintaining good tear resistance and good abrasion resistance, each comparable to the reference material.

In addition to the above unexpected properties, the inventive EPDM/NR blends provide an unexpected advantage of a higher resilience of rubber products, such as truck treads, at 23⁰C, which indicates a lower rolling resistance. The same EPDM/NR blends can replace conventional NR formulations used in dynamic applications, such as belts or engine mounts.

In particular, the invention provides a composition comprising the following: a) at least one polyisoprene, and b) at least one ethylene/α-olefm/diene (EAODM) interpolymer, and wherein the at least one EAODM has a Mooney viscosity, ML(I +4) at

125⁰C, greater than 60, preferably greater than 70, more preferably greater than 80, even more preferably greater than 90, and most preferably greater than 100. Mooney viscosity is that of the neat interpolymer (or calculated viscosity of neat polymer for polymers that contain a filler, such as carbon black, and/or an oil). In regard to Mooney viscosity, the neat polymer refers to the polymer without filler (for example carbon black) and without oil.

In a preferred embodiment, the at least one EAODM polymer is an EPDM interpolymer.

In another embodiment, the at least one polyisoprene is a natural polyisoprene or a synthetic polyisoprene, and preferably a natural polyisoprene. In another embodiment, the at least one polyisoprene is a natural cis-l,4-polyisoprene. In another embodiment, the at least one polyisoprene is a synthetic cis-l,4-polyisprene. In another embodiment, the at least one polyisoprene has a Mooney viscosity, ML(l+4) at 100⁰C, from 20 to 80.

In another embodiment, the at least one polyisoprene is derived from a nongranular, bale form.

In another embodiment, at least one EAODM has a Mooney viscosity, ML(I +4) at 125⁰C, from greater than 60 to 200, preferably from 80 to 180, and more preferably from 100 to 160. In another embodiment, the Mooney viscosity, ML(I +4) at 125⁰C , is less than, or equal to, 300. Mooney viscosity is that of the neat interpolymer (or calculated viscosity of neat polymer). In a further embodiment, the at least one EAODM is an EPDM interpolymer.

In another embodiment, the composition further comprises at least one polybutadiene. In another embodiment, the at least one polybutadiene contains a high cis content of greater than 97 percent, based on the total weight of polymerizable monomer. In another embodiment, the at least one polybutadiene has a Mooney viscosity, ML(l+4) at 100⁰C, from 20 to 80.

In another embodiment, the at least one polyisoprene is present in an amount from greater than, or equal to, 20 phr, based on hundred parts of the sum of the polyisoprene, EAODM (preferably EPDM), and optional polybutadiene, or based on hundred parts of the elastomers. Examples of elastomers include polyisoprene, EAODM, polybutadiene, and additional elastomers as described herein.

In another embodiment, the at least one EAODM (and preferably an EPDM) is present in an amount less than, or equal to, 80 phr, preferably less than, or equal to, 60 phr, and more preferably less than, or equal to, 40 phr, based on hundred parts of the sum of the polyisoprene, EAODM (preferably EPDM), and optional polybutadiene, or based on hundred parts of the elastomers.

In another embodiment, the at least one EAODM (and preferably an EPDM) is present in an amount greater than, or equal to, 10 phr, preferably greater than, or equal to, 20 phr, and more preferably greater than, or equal to, 22 phr, based on hundred parts of the sum of the polyisoprene, EAODM (preferably EPDM), and optional polybutadiene, or based on hundred parts of the elastomers.

In another embodiment, the at least one EAODM (and preferably an EPDM) has a weight average molecular weight, M_w, greater than 176,000 g/mole, preferably greater than, or equal to, 190,000 g/mole, and more preferably greater than, or equal to, 200,000 g/mole.

In another embodiment, the at least one EAODM (and preferably an EPDM) contains no oil. In another embodiment, the composition does not contain a paraffinic oil. Paraffinic oils are not compatible with polyisoprenes (natural rubber), and will migrate to the surface of a part, such as a tire, fabricated from a formulation containing a polyisoprene. This oil migration results in an oily, slippery part.

In another embodiment, the at least one EAODM has ethylene content greater than, or equal to, 40 weight percent, based on the total weight of polymerized monomers. In another embodiment, the at least one EAODM has ethylene content greater than, or equal to, 50 weight percent, based on the total weight of polymerized monomers. In another embodiment, the at least one EAODM has ethylene content greater than, or equal to, 55 weight percent, based on the total weight of polymerized monomers.

In another embodiment, the at least one EAODM (and preferably an EPDM) has ethylene content from 40 weight percent to 95 weight percent, preferably from 50 to 90 weight percent, and more preferably from 55 to 85 weight percent, based on the total weight of polymerized monomers.

In another embodiment, the at least one EAODM (and preferably an EPDM) has a diene content from 2 weight percent to 12 weight percent, preferably from 2.5 to 10 weight percent, and more preferably from 3 to 8 weight percent, based on the total weight of polymerized monomers.

In another embodiment, the at least one EAODM (and preferably an EPDM) has a diene content from 1 weight percent to 40 weight percent, preferably from 1.5 to 30 weight percent, and more preferably from 2 to 20 weight percent, based on the total weight of polymerized monomers.

In another embodiment, the EAODM (and preferably an EPDM) is a homogeneously branched linear interpolymer or a homogeneously branched substantially linear interpolymer. In another embodiment, the EAODM (and preferably an EPDM) is a homogeneously branched substantially linear interpolymer. In another embodiment, the EAODM (and preferably an EPDM) is a homogeneously branched linear interpolymer.

In another embodiment, the EAODM (and preferably an EPDM) contains at least one diene selected from the group consisting of 5-ethylidene-2-norbornene, dicyclopentadiene and 1 ,4-hexadiene, preferably 5-ethylidene-2-norbornene and dicyclopentadiene, and more preferably 5-ethylidene-2-norbornene.

In another embodiment, the EAODM (and preferably an EPDM) has a molecular weight distribution (M_w/M_n) less than 5, preferably less than 4, and more preferably less than 3.

In another embodiment, the at least one polyisoprene is a natural cis-1,4- polyisoprene. In yet another embodiment, the at least one polyisoprene is a synthetic cis-1 ,4-polyisprene. In another embodiment, the at least one polyisoprene has a Mooney viscosity, ML(l+4) at 100⁰C, from 20 to 80, preferably from 30 to 75, and more preferably from 40 to 70.

In another embodiment, the composition further comprises the at least one filler. In a further embodiment, the at least one filler is selected from the group consisting of silica; carbon black; clay; titanium dioxide; silicates of aluminum, magnesium, calcium, sodium, potassium and mixtures thereof; carbonates of calcium, magnesium and mixtures thereof; oxides of silicon, calcium, zinc, iron, titanium, and aluminum; sulfates of calcium, barium, and lead; alumina trihydrate; magnesium hydroxide; and mixtures thereof.

In another embodiment, the composition further comprises at least one additive selected from the group consisting of a pigment, a flame retardant, a scratch and mar resistant additive, and combinations thereof.

In another embodiment, the at least one EAODM contains from 1 to 50 phr of carbon black, based on hundred parts of the sum of the polyisoprene, EAODM (preferably EPDM), and optional polybutadiene, or based on hundred parts of the elastomers.

In another embodiment, the composition further comprises one or more other different ethylene/α-olefin interpolymers.

An inventive composition may comprise a combination of two or more embodiments as described herein.

The invention also provides an article, comprising at least one component formed from an inventive composition.

In a further embodiment, the article is in an automotive part. In yet a further embodiment, the article is a tire.

In another embodiment, the article is an engine mount. In yet another embodiment, the article is a belt. In another embodiment, the article is a hose. In another embodiment, the article is a building or construction material. In another embodiment, the article is a shoe component.

An inventive article may comprise a combination of two or more embodiments as described herein. The invention also provides a method of making a polymeric formulation, said method comprising mixing a composition comprising at least one polyisoprene, at least one EAODM polymer, and optionally, at least one oil and/or at least one filler, and wherein the at least one EAODM has a Mooney viscosity, ML(l+4) at 125⁰C, greater than 60, preferably greater than 70, and more preferably greater than 80, even more preferably greater than 90, and most preferably greater than 100. Mooney viscosity is that of the neat interpolymer (or calculated viscosity of neat polymer for polymers that contain a filler, such as carbon black, and/or an oil). In a preferred embodiment, the EAODM is an EPDM interpolymer.

In a further embodiment, the at least one oil is selected from the group consisting of aromatic oils and naphthenic oils.

An inventive method may comprise a combination of two or more embodiments as described herein.

Ethylene/α-Olefϊn/Diene

The ethylene/α-olefm/diene (EAODM) interpolymers of the present invention have polymerized therein C2 (ethylene), at least one C3-C20 α-olefm (ethylenically unsaturated) monomer, and, typically, a C4-C40 diene monomer. The α-olefm may be either an aliphatic or an aromatic compound, and may contain vinylic unsaturation or a cyclic compound, such as styrene, p-methyl styrene, cyclobutene, cyclopentene, and norbornene, including norbornene substituted in the 5 and 6 position with C1-C20 hydrocarbyl groups. The α-olefm is preferably a C3-C20 aliphatic compound, preferably a C3-C16 aliphatic compound, and more preferably a C3-C10 aliphatic compound. Preferred ethylenically unsaturated monomers include 4- vinylcyclohexene, vinylcyclohexane, and C3-C10 aliphatic α-olefms (especially propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-l-pentene, 4-methyl- 1-pentene, 1-octene, 1-decene and 1-dodecene). A more preferred C3-C10 aliphatic α-olefm is selected from the group consisting of propylene, 1-butene, 1-hexene and 1- octene, and more preferably propylene. In a preferred embodiment, the EAODM polymer is an EPDM interpolymer. In a further embodiment, the diene is 5- ethylidene-2-norbornene (ENB). In another embodiment, the EAODM polymer is used in a dry form, without an oil extender. In another embodiment, the EAODM polymer is an EPDM interpolymer, which is used in a dry form, without an oil extender. In a further embodiment, the diene is 5-ethylidene-2-norbornene (ENB).

In one embodiment, the EAODM interpolymer of the present invention has a C2 (ethylene) content of from 40 to 95 weight percent, more preferably from 50 to 93 weight percent, and most preferably from 55 to 90 weight percent, based on the total weight of polymerized monomers. The interpolymers also contain at least one α- olefin, other than C2, typically at a level of from 5 to 80 weight percent, more preferably from 7 to 70 weight percent, and most preferably from 10 to 65 weight percent, based on the total weight of polymerized monomers.

In one embodiment, the interpolymer contains a non-conjugated diene, and the non-conjugated diene content is preferably from 0.5 to 25 weight percent, more preferably from 1 to 20 weight percent, and most preferably from 2 to 12 weight percent, based on total weight of polymerized monomers. In another embodiment, more than one diene may be incorporated simultaneously, for example 1 ,4-hexadiene and ENB, with total diene incorporation within the limits specified above.

In another embodiment, the diene monomer is desirably a non-conjugated diolefm that is conventionally used as a cure site for cross-linking. The nonconjugated diolefm can be a C6-C15 straight chain, branched chain or cyclic hydrocarbon diene. Illustrative nonconjugated dienes are straight chain acyclic dienes, such as 1 ,4-hexadiene and 1,5-heptadiene; branched chain acyclic dienes, such as 5 -methyl- 1 ,4-hexadiene, 2-methyl-l,5-hexadiene, 6-methyl-l,5-heptadiene, 7- methyl-l,6-octadiene, 3,7-dimethyl-l,6-octadiene, 3,7-dimethyl-l,7-octadiene, 5,7- dimethyl-l,7-octadiene, 1,9-decadiene, and mixed isomers of dihydromyrcene; single ring alicyclic dienes such as 1 ,4-cyclohexadiene, 1,5-cyclooctadiene and 1,5- cyclododecadiene; multi-ring alicyclic fused and bridged ring dienes, such as tetrahydroindene, methyl tetrahydroindene; alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as 5-methylene-2-norbornene (MNB), 5- ethylidene-2-norbornene (ENB), 5-vinyl-2-norbornene, 5-propenyl-2-norbornene, 5- isopropylidene-2-norbornene, 5-(4-cyclopentenyl)-2-norbornene, and 5- cyclohexylidene-2-norbornene. The diene is preferably a nonconjugated diene selected from the group consisting of ENB, dicyclopentadiene, 1 ,4-hexadiene, 7- methyl-l,6-octadiene, and preferably, ENB, dicyclopentadiene and 1 ,4-hexadiene, more preferably ENB and dicyclopentadiene, and even more preferably ENB.

In another embodiment, the diene is a conjugated diene selected from the group consisting of 1,3-pentadiene, 1,3-butadiene, 2 -methyl- 1,3 -butadiene, 4-methyl- 1,3-pentadiene, or 1,3-cyclopentadiene. The EAODM diene monomer content, whether it comprise a conjugated diene, a non-conjugated diene or both, may fall within the limits specified above for non-conjugated dienes.

In one embodiment, an EAODM may contain a monomer that induces long chain branching. Such diene monomers include dicyclopentadiene, NBD, methyl norbornadiene, vinyl-norbornene, 1,6-heptadiene, 1,7-octadiene, and 1,9-decadiene. When added, such monomers are typically added in an amount within a range of from greater than zero to 3 weight percent, more preferably from 0.01 to 2 weight percent, based on total weight of polymerizable monomers.

Preferred interpolymers of the present invention have polymerized therein ethylene at least one α-olefm and 5-ethylidene-2-norbornene (ENB). The α-olefm is preferably a C3-C20 aliphatic compound, more preferably a C3-C12 aliphatic compound, and even more preferably a C3-C8 aliphatic compound. Preferred α- olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-l- pentene, 4- methyl-1-pentene, 1-heptene, 1-octene, 1-decene and 1-dodecene. More preferred α- olefins include propylene, 1-butene, 1-hexene and 1-octene, and most preferably propylene. In a preferred embodiment, the interpolymer has polymerized therein ethylene, propylene and 5-ethylidene-2-norbornene.

In another embodiment, the amount of ENB in the interpolymers of the invention is from 0.5 to 15 weight percent, preferably from 1 to 10 weight percent, and more preferably from 2 to 8 weight percent, based on the total weight of polymerized monomers.

In general, polymerization may be accomplished at conditions well known in the art for Ziegler-Natta or Kaminsky-Sinn type polymerization reactions, that is, temperatures from 0⁰C to 250⁰C, preferably 30⁰C to 200⁰C, and pressures from atmospheric to 10,000 atmospheres. Polymerizations may also be conducted in accordance with processes disclosed in U.S. Patent 6,680,361 (equivalent of International Publication No. WO 00/26268), fully incorporated herein by reference.

Polymerizations may be performed using a suspension, solution, slurry, or gas phase polymerization, or combinations thereof. In one embodiment, the polymerization is conducted in a solution loop reactor, or is conducted in a gas phase reactor. In another embodiment, a solution fed catalyst is used in a solution polymerization or in a gas phase polymerization. In another embodiment, the catalyst is supported on a support, such as, silica, alumina, or a polymer (especially poly(tetrafluoroethylene) or a polyolefm), and may be spray dried onto such supports, and introduced in supported form into a polymerization reactor.

The polymerization may take place in any suitable type of reactor, and preferably a reactor design that would allow one skilled in the art to determine catalyst efficiency. Reactors include, but are not limited to, batch reactors, continuous reactors, pilot plant reactors, a laboratory scale reactors, a high throughput polymerization reactors, and other types of commercial reactors.

Gas phase polymerizations are described in U.S. Patent 5,264,506; U.S. Patent 4,543,399; and European Patent EP 0089691B1; each is fully incorporated herein by reference. In one embodiment, the EAODM (preferably an EPDM) is polymerized in the gas phase in the presence of a partitioning agent (or filler). In a further embodiment, the partitioning agent is carbon black.

Inert liquids are suitable solvents for polymerizations, such as solution polymerizations. Examples include straight-chain and branched-chain hydrocarbons, such as isobutane, butane, pentane, hexane, heptane, octane, and mixtures thereof; cyclic and alicyclic hydrocarbons, such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof; perfluorinated hydrocarbons, such as perfluorinated C4-C10 alkanes; and aromatic and alkyl- substituted aromatic compounds, such as benzene, toluene, xylene, and ethylbenzene. Suitable solvents also include liquid olefins that may act as monomers or comonomers including butadiene, cyclopentene, 1-hexene, 4-vinyl-cyclohexene, 3-methyl-l- pentene, 4-methyl-l-pentene, 1 ,4-hexadiene, 1-octene, 1-decene, styrene, divinylbenzene, allylbenzene, and vinyltoluene (including all isomers alone or in admixture). Mixtures of the foregoing are also suitable. If desired, normally gaseous olefins can be converted to liquids by application of pressure, and used herein.

Suitable catalysts for use herein, preferably include constrained geometry catalysts, as disclosed in U.S. Patent Nos. 5,272,236 and 5,278,272, which are both incorporated herein, in their entirety, by reference. The monocyclopentadienyl transition metal olefin polymerization catalysts taught in U.S. Patent No. 5,026,798, the teachings of which are incorporated herein by reference, are also suitable as catalysts of the invention.

The foregoing catalysts may be further described as comprising a metal coordination complex, comprising a metal of groups 3-10 or the Lanthanide series of the Periodic Table of the Elements, and a delocalized π- bonded moiety, substituted with a constrain-inducing moiety, said complex having a constrained geometry about the metal atom, such that the angle at the metal between the centroid of the delocalized, substituted π- bonded moiety, and the center of at least one remaining substituent, is less than such angle in a similar complex, containing a similar π- bonded moiety lacking in such constrain-inducing substituent. In addition, for such complexes comprising more than one delocalized, substituted x-bonded moiety, only one thereof, for each metal atom of the complex, is a cyclic, delocalized, substituted π-bonded moiety. The catalyst further comprises an activating cocatalyst.

Preferred catalyst complexes correspond to the Structure I:

Structure I .

In Structure I, M is a metal of group 3-10, or the Lanthanide series of the Periodic Table of the Elements;

Cp* is a cyclopentadienyl or substituted cyclopentadienyl group bound in an η5 bonding mode to M;

Z is a moiety comprising boron, or a member of group 14 of the Periodic Table of the Elements, and optionally sulfur or oxygen, said moiety having up to 20 non-hydrogen atoms, and optionally Cp* and Z together form a fused ring system; X independently each occurrence is an anionic ligand group or neutral Lewis base ligand group having up to 30 non-hydrogen atoms; n is 0, 1, 2, 3, or 4 and is 2 less than the valence of M; and

Y is an anionic or nonanionic ligand group bonded to Z and M comprising nitrogen, phosphorus, oxygen or sulfur and having up to 20 non-hydrogen atoms, optionally Y and Z together form a fused ring system. More specific complexes are described in U.S. Patents 5,272,236 and 5,278,272, incorporated herein by reference.

Specific compounds include: (tert-butylamido) (tetramethyl-η5 - cyclopentadienyl)- 1 ,2-ethanediylzirconium dichloride, (tert-butylamido)(tetramethyl- η 5 -cyclopentadienyl) 1 ,2-ethanediyltitanium dichloride, (methylamido)(tetramethyl- η5 - cyclopentadienyl)- 1 ,2-ethanediylzirconium dichloride, (methylamido) (tetramethyl-η5 cyclopentadienyl)- 1 ,2-ethanediyltitanium dichloride, (ethylamido)(tetramethyl-η5-cyclopentadienyl)-methylenetitanium dichloro, (tertbutylamido)dibenzyl(tetramethyl-η5 -cyclopentadienyl) silanezirconium dibenzyl, (benzylamido)dimethyl(tetramethyl-η5-cyclopentadienyl)silanetitanium dichloride, (phenylphosphido) dimethyl(tetramethyl η 5 -cyclopentadieny^silanezirconium dibenzyl, (tertbutylamido)dimethyl(tetramethyl-η5-cyclopentadienyl) silanetitanium dimethyl, and the like.

The complexes may be prepared by contacting a derivative of a metal, M, and a group I metal derivative or Grignard derivative of the cyclopentadienyl compound, in a solvent, and separating the salt byproduct. Suitable solvents for use in preparing the metal complexes are aliphatic or aromatic liquids, such as cyclohexane, methylcyclohexane, pentane, hexane, heptane, tetrahydrofuran, diethyl ether, benzene, toluene, xylene, ethylbenzene, and the like, or mixtures thereof.

Suitable cocatalysts for use herein include polymeric or oligomeric aluminoxanes, especially methyl aluminoxane, as well as inert, compatible, noncoordinating, ion forming compounds. The so-called modified methyl aluminoxane (MMAO) is also suitable for use as a cocatalyst. One technique for preparing such modified aluminoxane is disclosed in U.S. Patent No. 5,041,584, the teachings of which are incorporated herein by reference. Aluminoxanes can also be made, as disclosed in U.S. Patent Nos. 4,544,762; 5,015,749; and 5,041,585, the entire content of each is incorporated herein by reference. Preferred cocatalysts are inert, noncoordinating, boron compounds, or aluminoxanes.

In addition to constrained geometry catalysts, additional single site catalyst systems that are suitable for use herein include metallocene catalyst systems and post metallocene catalyst systems.

Metallocene catalysts are, for example, coordination complexes between a transition metal, usually from group IV, in particular titanium, zirconium or hafnium, and two optionally substituted cyclopentadienyl ligands. These catalysts are used in combination with a co-catalyst, for example an aluminoxane, preferably methylaluminoxane, or a boron compound (see, for example, Adv. Organomet. Chem, Vol. 18, p. 99, 10 (1980); Adv. Organomet. Chem, Vol. 32, p. 325, (1991); J.M.S.- Rev. Macromol. Chem. Phys., Vol. C34(3), pp. 439-514, (1994); J. Organometallic Chemistry, Vol. 479, pp. 1-29, (1994); Angew. Chem. Int., Ed. Engl, Vol. 34, p. 1143, (1995) Prog. Polym. ScL, Vol. 20, p. 459 15 (1995); Adv. Polym. ScL, Vol. 127, p. 144, (1997); U.S. Patent 5,229,478, or International applications WO 93/19107, EP 129 368, EP 277 003, EP 277 004, EP 632 065).

The ethylene/α-olefm/diene interpolymers of the invention may be branched and/or unbranched interpolymers. The presence or absence of branching in the ethylene/α-olefm interpolymers, and if branching is present, the amount of branching, can vary widely, and may depend on the desired processing conditions and the desired polymer properties.

The nature of the ethylene/α-olefin/diene branching can vary for convenience. The ability to incorporate LCB into polymer backbones is known. In U.S. Patent 3,821,143, a 1 ,4-hexadiene was used as a branching monomer to prepare ethylene/propylene/diene (EPDM) polymers having LCB. Such branching agents are sometimes referred to as H branching agents. U.S. Patents 6,300,451 and 6,372,847 also use various H type branching agents to prepare polymers having LCB. In U.S. patent 5,278,272, it was discovered that constrained geometry catalysts (CGC) have the ability to incorporate vinyl terminated macromonomers into the polymer backbone to form LCB polymers. Such branching is referred to as T type branching. Each of these patents (U.S. Patents 3,821,143; 6,300,451; 6,372,847 and 5,278,272) is fully incorporated herein by reference. U.S. Patent 5,278,272 teaches such constrained geometry catalysts (CGC) are unique in their ability to incorporate large unsaturated molecules into a polymer backbone. The amount of LCB that can be incorporated by these CGC is typically from 0.01 LCB/1000 carbon atoms to 3 LCB/1000 carbon atoms (both backbone and branched carbon atoms). Long chain branching is determined by using 13 C Nuclear Magnetic Resonance (NMR) spectroscopy, and is quantified using the method of Randall (Rev. Macromol. Chem. Phys., 1989, C29 (2&3), p. 285-297), the disclosure of which is incorporated herein by reference.

In one embodiment, the type of LCB in the interpolymers used in the practice of this invention is T-type branching, as opposed to H-type branching. T-type branching is typically obtained by copolymerization of ethylene and comonomer(s) with chain end unsaturated macromonomers, in the presence of a constrained geometry catalyst under the appropriate reactor conditions, such as, for example, those described in WO 00/26268 (U.S. equivalent, U.S. Patent 6,680,361) or U.S. Patent 5,728,272, each fully incorporated herein in by reference). If extremely high levels of LCB are desired, H-type branching is the preferred method, since T-type branching has a practical upper limit to the degree of LCB. As discussed in WO 00/26268, as the level of T-type branching increases, the efficiency or throughput of the manufacturing process decreases significantly, until the point is reached where production becomes economically unviable. The T-type LCB polymers can be produced by constrained geometry catalysts, without measurable gels, but with very high levels of T-type LCB. Because the macromonomer being incorporated into the growing polymer chain has only one reactive unsaturation site, the resulting polymer only contains side chains of varying lengths, and at different intervals along the polymer backbone.

As discussed above, H-type branching is typically obtained by copolymerization of ethylene or other alpha olefins with a diene having two double bonds reactive with a nonmetallocene type of catalyst in the polymerization process. As the name implies, the diene attaches one polymer molecule to another polymer molecule through a diene bridge; the resulting polymer molecule resembling an H that might be described as more of a crosslink than a long chain branch. H-type branching is typically used when extremely high levels of branching are desired. If too much diene is used, the polymer molecule can form so much branching or crosslinking that the polymer molecule is no longer soluble in the reaction solvent (in a solution process), and consequently falls out of solution, resulting in the formation of gel particles in the polymer. Additionally, use of H-type branching agents may deactivate metallocene catalysts, and reduce catalyst efficiency. Thus, when H-type branching agents are used, the catalysts used are typically not metallocene catalysts. U.S. Patent 6,372,847 discloses the use of vanadium type catalysts to prepare H-type branched polymers.

Examples of suitable ethylene interpolymers for use in the invention include NORDEL™ polymers available from The Dow Chemical Company.

In one embodiment of the invention, the ethylene/α-olefin/diene interpolymer (EAODM) has a molecular weight distribution (Mw/Mn) from 1.1 to 5, more preferably from 1.2 to 4 and most preferably from 1.5 to 3. All individual values and subranges from 1.1 to 5 are included herein and disclosed herein. In a preferred embodiment, the ethylene/α-olefin/diene interpolymer is an ethylene/propylene/diene interpolymer.

In another embodiment, the ethylene/α-olefin/diene interpolymer has a density from 0.81 to 0.96 g/cc, preferably from 0.82 to 0.95 g/cc, and more preferably from 0.83 to 0.94 g/cc. All individual values and subranges from 0.81 to 0.96 g/cc are included herein and disclosed herein. In another embodiment, the ethylene/α- olefin/diene interpolymer has a density greater than, or equal to, 0.82 g/cc, preferably greater than, or equal to, 0.83 g/cc, and more preferably greater than, or equal to, 0.84 g/cc. In another embodiment, the ethylene/α-olefin/diene interpolymer has a density less than, or equal to, 0.96 g/cc, preferably less than, or equal to, 0.94 g/cc, and more preferably less than, or equal to, 0.93 g/cc. In a preferred embodiment, the ethylene/α-olefin/diene interpolymer is an ethylene/propylene/diene interpolymer.

In another embodiment, the EAODM has a Mooney viscosity, ML(I +4) at 125⁰C, greater than 60, preferably greater than 70, more preferably greater than 80, even more preferably greater than 90, and most preferably greater than 100. In a preferred embodiment, the at least one EAODM polymer is an EPDM interpolymer.

In another embodiment, the EAODM has a Mooney viscosity, ML(I +4) @ 125⁰C, less than, or equal to, 200, preferably less than, or equal to, 180, more preferably less than, or equal to, 160. In a preferred embodiment, the at least one EAODM polymer is an EPDM interpolymer.

In another embodiment, at least one EAODM has a Mooney viscosity, ML(I +4) at 125⁰C, from 60 to 200, preferably from 80 to 180, and more preferably from 100 to 160. In another embodiment, the at least one EAODM has a Mooney viscosity, ML(l+4) at 125⁰C, less than, or equal to, 300. In a preferred embodiment, the at least one EAODM is an EPDM interpolymer.

As discussed above, Mooney viscosity is that of the neat interpolymer (or calculated viscosity of neat polymer for polymers that contain a filler, such as carbon black, and/or an oil). The neat polymer refers to the polymer without filler and without oil.

In another embodiment, the ethylene/α-olefm/diene interpolymer has a number average molecular weight, (M_n) from 80,000 g/mole to 300,000 g/mole, more preferably from 90,000 g/mole to 200,000 g/mole. All individual values and subranges from 80,000 g/mole to 300,000 g/mole are included herein and disclosed herein. In a preferred embodiment, the ethylene/α-olefm/diene interpolymer is an ethylene/propylene/diene interpolymer.

In another embodiment, the ethylene/α-olefm/diene interpolymer has a number average molecular weight, (M_n) from 40,000 g/mole to 200,000 g/mole, more preferably from 50,000 g/mole to 150,000 g/mole, and most preferably from 60,000 g/mole to 100,000 g/mole. All individual values and subranges from 40,000 g/mole to 200,000 g/mole are included herein and disclosed herein. In a preferred embodiment, the ethylene/α-olefm/diene interpolymer is an ethylene/propylene/diene interpolymer.

In another embodiment, the ethylene/α-olefm/diene interpolymer has a weight average molecular weight, (M_w) from 170,000 g/mole to 600,000 g/mole, more preferably from 180,000 g/mole to 500,000 g/mole, and most preferably from 185,000 g/mole to 400,000 g/mole. All individual values and subranges from 170,000 g/mole to 600,000 g/mole are included herein and disclosed herein. In a preferred embodiment, the ethylene/α-olefm/diene interpolymer is an ethylene/propylene/diene interpolymer. In another embodiment, the ethylene/α-olefϊn/diene interpolymer is a homogeneously branched linear or homogeneously branched substantially linear ethylene/α-olefm interpolymer. In a preferred embodiment, the ethylene/α- olefm/diene interpolymer is an ethylene/propylene/diene interpolymer.

Processes for preparing homogeneous polymers are disclosed in U.S. Patent 5,206,075; U.S. Patent 5,241,031; and PCT International Publication Nos. WO 93/03093 and WO 90/03414; each of which is incorporated, herein, by reference in its entirety.

The terms "homogeneous" and "homogeneously-branched" are used in reference to an ethylene/α-olefm polymer (or interpolymer), in which the comonomer(s) is/are randomly distributed within a given polymer molecule, and substantially all of the polymer molecules have the same ethylene -to-comonomer(s) ratio. The homogeneously branched ethylene interpolymers include linear ethylene interpolymers, and substantially linear ethylene interpolymers.

Included amongst the homogeneously branched linear ethylene interpolymers are ethylene interpolymers, which lack long chain branching (or measurable amounts of long chain branching), but do have short chain branches, derived from the comonomer(s) polymerized into the interpolymer, and which are homogeneously distributed, both within the same polymer chain, and between different polymer chains. That is, homogeneously branched linear ethylene interpolymers lack long chain branching, just as is the case for the linear low density polyethylene polymers or linear high density polyethylene polymers, made using uniform branching distribution polymerization processes, as described, for example, by Elston in U.S. Patent 3,645,992.

Substantially linear ethylene interpolymers are described in U.S. Patent Nos. 5,272,236 and 5,278,272; the entire contents of each are herein incorporated by reference. As discussed above, the substantially linear ethylene interpolymers are those in which the comonomer(s) is/are randomly distributed within a given interpolymer molecule, and in which substantially all of the interpolymer molecules have the same ethylene/comonomer(s) ratio within that interpolymer. Substantially linear ethylene interpolymers are prepared using a constrained geometry catalyst. As discussed above, examples of constrained geometry catalysts, and such preparations, are described in U.S Patent Nos. 5,272,236 and 5,278,272.

In addition, the substantially linear ethylene interpolymers are homogeneously branched ethylene polymers having long chain branching. The long chain branches have about the same comonomer distribution as the polymer backbone, and can have about the same length as the length of the polymer backbone. As discussed above, "substantially linear," typically, is in reference to a polymer that is substituted, on average, with 0.01 long chain branches per 1000 total carbons (including both backbone and branch carbons) to 3 long chain branches per 1000 total carbons.

The substantially linear ethylene interpolymers form a unique class of homogeneously branched ethylene polymers. They differ substantially from the well- known class of conventional, homogeneously branched linear ethylene interpolymers, described by Elston in U.S. Patent 3,645,992, and, moreover, they are not in the same class as conventional heterogeneous, "Ziegler-Natta catalyst polymerized" linear ethylene polymers (for example, ultra low density polyethylene (ULDPE), linear low density polyethylene (LLDPE) or high density polyethylene (HDPE), made, for example, using the technique disclosed by Anderson et al., in U.S. Patent 4,076,698); nor are they in the same class as high pressure, free-radical initiated, highly branched polyethylenes, such as, for example, low density polyethylene (LDPE), ethylene- acrylic acid (EAA) copolymers and ethylene vinyl acetate (EVA) copolymers.

An ethylene/α-olefm/diene interpolymer may have a combination of two or more embodiments as described herein.

Polyisoprene

Polyisoprenes include both natural polyisprene and synthetic polyisoprene. Suitable polyisprenes include, but are not limited to, natural cis-l,4-polyisoprene, synthetic cis-l,4-polyisoprene, high vinyl 3,4-polyisoprene and 3,4-polyisoprene.

In one embodiment, the polyisoprene has a Mooney Viscosity (ML 1+4 at 100⁰C) greater than, or equal to, 20, and preferably greater than, or equal to, 40.

In another embodiment, the polyisoprene has a Mooney Viscosity (ML 1+4 at 100⁰C) less than, or equal to, 100, and preferably less than, or equal to, 80. In another embodiment, the polyisoprene has a Mooney Viscosity (ML 1+4 at 100⁰C) from 20 to 100, and preferably from 40 to 80.

Suitable examples of polyisoprenes include the following technical grades: SMR (Standard Malaysian Rubber), such as SRM 5 and SMR 20; TSR (Technical Specified Rubber) and RSS (Ribbed Smoked Sheets).

A polyisoprene may have a combination of two or more embodiments as described herein.

Polybutadiene

Suitable polybutadienes include, but are not limited to, cis-l,4-polybutadiene, trans- 1 ,4-polybutadiene, vinyl- 1 ,2-polybutadiene.

In one embodiment, the polybutadiene has a Mooney Viscosity (ML 1+4 at 100⁰C) greater than, or equal to, 10, preferably greater than, or equal to, 15, and more preferably greater than, or equal to, 20.

In another embodiment, the polybutadiene has a Mooney Viscosity (ML 1+4 at 100⁰C) less than, or equal to, 100, preferably less than, or equal to, 90, and more preferably less than, or equal to, 80.

In another embodiment, the polybutadiene has a Mooney Viscosity (ML 1+4 at 100⁰C) from 10 to 100, preferably from 15 to 90, and more preferably from 20 to 80.

Examples of suitable polybutadienes include EUROPRENE NEOCIS BR 40 from POLIMERI EUROPA, and BUNA CB 24 from LANXESS.

A polybutadiene may comprise a combination of two or more embodiments as described herein.

Additional Elastomers

Additional polymers include, but are not limited to, copolymers of styrene and butadiene, copolymers of isoprene and butadiene, interpolymers of styrene, isoprene and butadiene, and interpolymers of chloroprene (2-chloro,l,3-butadiene = chloroprene). In one embodiment, the polymer has a Mooney Viscosity (ML 1+4 at 100⁰C) greater than, or equal to, 10, preferably greater than, or equal to, 15, and more preferably greater than, or equal to, 20.

In another embodiment, the polymer has a Mooney Viscosity (ML 1+4 at 100⁰C) less than, or equal to, 100, preferably less than, or equal to, 90, and more preferably less than, or equal to, 80.

In another embodiment, the polymer has a Mooney Viscosity (ML 1+4 at 100⁰C) from 10 to 100, preferably from 15 to 90, and more preferably from 20 to 80.

Additives

An inventive composition may comprise one or more additives. Suitable additives include, but are not limited to, fillers, antioxidants, UV stabilizers, vulcanizing agents, flame retardants, colorants or pigments, and combinations thereof.

Fillers for use as an additive in the invention include carbon black; silicates of aluminum, magnesium, calcium, sodium, potassium and mixtures thereof; carbonates of calcium, magnesium and mixtures thereof; oxides of silicon, calcium, zinc, iron, titanium, and aluminum; sulfates of calcium, barium, and lead; alumina trihydrate; magnesium hydroxide; phenol-formaldehyde, polystyrene, and poly(alphamethyl)- styrene resins, natural fibers, synthetic fibers, and the like.

Plasticizers employed as additives in the invention include petroleum oils, such as ASTM D2226 aromatic and naphthenic oils; polyalkylbenzene oils; organic acid monoesters, such as alkyl and alkoxyalkyl oleates and stearates; organic acid diesters, such as dialkyl, dialkoxyalkyl, and alkyl aryl phthalates, terephthalates, sebacates, adipates, and glutarates; glycol diesters, such as tri-, terra-, and polyethylene glycol dialkanoates; trialkyl trimellitates; trialkyl, trialkoxyalkyl, alkyl diaryl, and triaryl phosphates; chlorinated paraffin oils; coumarone-indene resins; pine tars; vegetable oils, such as castor, tall, rapeseed, and soybean oils and esters and epoxidized derivatives thereof; and the like.

Antioxidants and antiozonants additives for use in the invention include hindered phenols, bisphenols, and thiobisphenols; substituted hydroquinones; tris(alkylphenyl)phosphites; dialkylthiodipropionates; phenylnaphthylamines; substituted diphenylamines; dialkyl, alkyl aryl, and diaryl substituted p-phenylene diamines; monomeric and polymeric dihydroquino lines; 2-(4-hydroxy-3,5-t- butylaniline)-4,6-bis(octylthio)l,3,5-triazine, hexahydro-l,3,5-tris-β-(3,5-di-t-butyl-4- hydroxyphenyl)propionyl-s-triazine, 2,4,6-tris(n- 1 ,4-dimethylpentylphenylene- diamino)- 1 ,3 ,5 -triazine, tris-(3 ,5 -di-t-butyl-4-hydroxybenzyl)isocyanurate, nickel dibutyldithiocarbamate, 2-mercaptotolylimidazole and its zinc salt, petroleum waxes, and the like.

Other optional additives for use in the invention include activators (metal oxides such as zinc, calcium, magnesium, cadmium, and lead oxides; fatty acids such as stearic, lauric, oleic, behenic, and palmitic acids and zinc, copper, cadmium, and lead salts thereof; di-, tri-, and polyethylene glycols; and triethanolamine; accelerators (sulfenamides such as benzothiazoles, including bis-benzothiazoles, and thiocarbamyl sulfenamides, thiazoles, dithiocarbamates, dithiophosphates, thiurams, guanidines, xanthates, thioureas, and mixtures thereof); tackifiers (rosins and rosin acids, hydrocarbon resins, aromatic indene resins, phenolic methylene donor resins, phenolic thermosetting resins, resorcenol-formaldehyde resins, and alkyl phenol formaldehyde resins such as octylphenol-formaldehyde resin); homogenizing agents, peptizers, pigments, flame retardants, fungicides, and the like. The total amount of optional ingredients can range from about 40 to 800 parts by weight based upon 100 parts of the elastomers in the composition.

Vulcanizing agents for use in the invention include sulfur-containing compounds, such as elemental sulfur, 4,4'-dithiodimorpholine, thiuram di-and polysulfides, alkylphenol disulfides, and 2-morpholino-dithiobenzothiazole; peroxides, such as di-tertbutyl peroxide, tertbutylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di-(tertbutylperoxy) hexane, di-(tertbutylperoxyisopropyl) benzene, tertbutyl peroxybenzoate and l,l-di-(tertbutylperoxy)-3,3,5-trimethylcyclohexane; metal oxides, such as zinc, magnesium, and lead oxides; dinitroso compounds, such as p-quinone-dioxime and p,p'-dibenzoylquinone-dioxime; and phenol-formaldehyde resins containing hydroxymethyl or halomethyl functional groups. The suitability of any of these vulcanizing agents for use in the invention will be largely governed by the choice of elastomers, as is well known to those skilled in the compounding art.

In one embodiment of the invention, the sulfur containing compounds and the peroxides are the preferred vulcanizing agents, and the sulfur containing compounds are most preferred. It is understood that mixtures of these vulcanizing agents can be employed, though this is generally not preferred. The amount of the vulcanizing agent can range from about 1 to 10 parts by weight, based upon 100 parts of the elastomers in the composition.

Sulfur can be a crystalline elemental sulfur or an amorphous elemental sulfur, and either type can be in pure form or supported on an inert carrier. An example of a supported sulfur is Rhenogran S-80 (80% S and 20% inert carrier) from Rhein Chemie.

Vulcanization temperatures and time employed are typical. Temperatures ranging from about 250⁰F to about 440⁰F, and times ranging from about one minute to about 120 minutes can be employed.

In another embodiment, the composition contains a flame retardant, for example a metal hydrate, such as aluminum trihydroxide, magnesium dihydroxide, or combinations thereof. In a further embodiment, the flame retardant is a metal hydrate, and present in an amount between 25 weight percent and 75 weight percent, based on the total weight of the composition. In another embodiment, the surface of the metal hydroxide may be coated with one or more materials, including silanes, titanates, zirconates, carboxylic acids, and maleic anhydride-grafted polymers. In another embodiment, the average particle size of the metal hydrate may range from less than 0.1 micrometers to 50 micrometers. In some cases, it may be desirable to use a metal hydroxide having a nano-scale particle size. The metal hydroxide may be naturally occurring or synthetic. The flame-retardant composition may contain other flame- retardant additives. Other suitable non-halogenated flame retardant additives include calcium carbonated, I red phosphorus, silica, alumina, titanium oxides, talc, clay, organo-modified clay, zinc t borate, antimony trioxide, wollastonite, mica, magadiite, organo-modified magadiite, silicone polymers, phosphate esters, hindered amine stabilizers, ammonium octamolybdate, intumescent compounds, and expandable graphite. Suitable halogenated flame retardant additives include decabromodiphenyl oxide, decabromodiphenyl ethane, ethylene-big (tetrabromophthalimide), and 1,4,7, 10-dimethanodibenzo(a,e)cyclooctene,l,2,3,4,7,8,9,10,13,13,14,14-dodecachloro l,4,4a,5,6,7,10,10a,l l,12,12a-dodecahydro-). A further description of such flame retardants is found in International Publication No. WO 2005/023924, fully incorporated herein by reference.

In another embodiment, the inventive compositions contain a compatibilizing amount of a flame retardant package, which includes a halogenated alkane flame retardant, an aromatic halogenated flame retardant, and optionally a flame retardant synergist. In a further embodiment, the alkane flame retardant is selected from hexahalocyclododecane; tetrabromocyclooctane; pentabromochlorocyclohexane; 1,2- dibromo-4-(l,2-dibromoethyl)cyclohexane; 1, 1,1,3-tetrabromononane; or a combination thereof. In another embodiment, the aromatic halogenated flame retardant comprises one or more of hexahalodiphenyl ethers; octahalodiphenyl ethers; decahalodiphenyl ethers; decahalobiphenyl ethanes; 1 ,2-bis(trihalophenoxy) ethanes; 1 ,2-bis(pentahalophenoxy) ethanes; a tetrahalobisphenol-A; ethylene(N, N')-bis- tetrahalophtlialimides; tetrabromobisphenol-A bis-(2,3-dibromopropyl ether); tetrahalophthalic anhydrides; hexahalobenzenes; halogenated indanes; halogenated phosphate esters; halogenated polystyrenes; polymers of halogenated bisphenol-A and epichlorohydrin; or a combination thereof. In yet another embodiment, the flame retardant synergist comprises one or more of a metal oxide, halogenated paraffin, triphenylphosphate, dimethyldiphenylbutane, polycumyl, or a combination thereof.

In another embodiment, the composition contains from about 0.5 to about 8 parts by weight halogenated alkane flame retardant; from about 0.5 to about 8 parts by weight aromatic halogenated flame retardant; from 0 to about 6 parts by weight flame retardant synergist, all based on the total weight of the composition. A further description of such flame retardants is found in International Publication No. WO 2002/12377, fully incorporated herein by reference.

The composition advantageously may further comprise at least one additive of the type conventionally added to polymers or polymer compositions. These additives include, for example, process oils; antioxidants; surface tension modifiers; UV stabilizers; scratch/mar additives, such as polydimethyl siloxane (PDMS) or functionalized polydimethyl siloxane or IRGASURF® SR 100 (available from Ciba Specialty Chemicals) or scratch mar formulations containing erucamide; anti-block agents; dispersants; blowing agents; linear or substantially linear EAOs; LDPE; LLDPE; lubricants; crosslinking agents such as peroxides; antimicrobial agents, such as organometallics, isothiazolones, organosulfurs and mercaptans; antioxidants, such as phenolics, secondary amines, phosphites and thioesters; antistatic agents, such as quaternary ammonium compounds, amines, and ethoxylated, propoxylated or glycerol compounds. Functionalized polydimethyl siloxanes include, but are not limited to, hydroxyl functionalized polydimethyl siloxane, amine functionalized polydimethyl siloxane, vinyl functionalized polydimethyl siloxane, aryl functionalized polydimethyl siloxane, alkyl functionalized polydimethyl siloxane, carboxyl functionalized polydimethyl siloxane, mercaptan functionalized polydimethyl siloxane, and derivatives of the same.

Additional additives include, but are not limited to, hydrolytic stabilizers; lubricants, such as fatty acids, fatty alcohols, esters, fatty amides, metallic stearates, paraffϊnic and microcrystalline waxes, silicones and orthophosphoric acid esters; mold release agents, such as fine-particle or powdered solids, soaps, waxes, silicones, polyglycols and complex esters, such as trimethylolpropane tristearate or pentaerythritol tetrastearate; pigments, dyes and colorants; plasticizers, such as esters of dibasic acids (or their anhydrides) with monohydric alcohols such as o-phthalates, adipates and benzoates; heat stabilizers, such as organotin mercaptides, an octyl ester of thioglycolic acid and a barium or cadmium carboxylate; ultraviolet light stabilizers used as a hindered amine, an o-hydroxy- phenylbenzotriazole, a 2-hydroxy, 4-alkoxyenzophenone, a salicylate, a cynoacrylate, a nickel chelate and a benzylidene malonate and oxalanilide; and zeolites, molecular sieves, anti-stat agents and other known deodorizers.

In a further embodiment, the composition also includes an ethylene homopolymer or ethylene interpolymer grafted with maleic anhydride or succinic anhydride groups, and preferably the grafted ethylene homopolymer or interpolymer comprises less than 20 percent of said composition. In yet a further embodiment, the composition also includes at least one additive, such as a plasticizer, a pigment or colorant, a UV stabilizer, or a filler. Fillers may include calcined or uncalcined fillers. Suitable fillers include, but are not limited to calcium carbonate and wollastonite. Suitable components for scratch mar resistant formulations are described in more detail in U.S. Patent 5,902,854, fully incorporated herein by reference. Example Compositions

In one embodiment, the composition comprises at least one polyisoprene and at least one EPDM, and the EPDM is present in an amount from 2 to 80 phr, preferably from 10 to 40 phr, and more preferably from 15 to 30 phr, based on the sum amount of polyisoprene, EPDM, optional polybutadiene, and optional styrene- butadiene interpolymer.

In a further embodiment, the EPDM has a Mooney viscosity ML(I +4) at 125⁰C greater than 60, preferably greater than 100, and more preferably greater than 120. In another embodiment, the EPDM has a weight average molecular weight (M_w) greater than 176,000, preferably greater than 200,000, and more preferably greater than 300,000. In another embodiment, the EPDM has an ethylene content from 40 and 90 weight percent, and preferably from 50 and 75 weight percent, based total weight of polymerized monomers. In another embodiment, the EPDM has a diene content from 2 and 12 weight percent, and preferably from 4 and 10 weight percent, based on total weight of polymerized monomers. The EPDM may have a combination of two or more embodiments as described above.

In another embodiment, the composition comprises from 10 to 40 phr, preferably from 13 to 35 phr, more preferably from 15 to 30 phr, and even more preferably 20 to 28 phr of the EPDM, based on the sum weight of the polyisoprene, EPDM, optional polybutadiene, and optional styrene-butadiene interpolymer. All individual values and subranges from 10 to 40 weight percent are included herein and disclosed herein.

In another embodiment, the composition comprises from 50 to 90 phr, preferably from 60 to 85 phr, and more preferably from 70 to 80 phr of the polyisoprene, based on the sum weight of the polyisoprene, EPDM, optional polybutadiene, and optional styrene-butadiene interpolymer. All individual values and subranges from 50 to 90 weight percent are included herein and disclosed herein.

In another embodiment, the composition comprises from 5 to 30 phr, preferably from 10 to 25 phr, and more preferably from 15 to 20 phr of the EPDM, based on the sum weight of the polyisoprene, EPDM, optional polybutadiene, and optional styrene-butadiene interpolymer. All individual values and subranges from 5 to 30 weight percent are included herein and disclosed herein. In another embodiment, the composition comprises from 25 to 100 phr, preferably from 30 to 90 phr, and more preferably from 35 to 75 phr of a filler, based on the sum weight of the polyisoprene, EPDM, optional polybutadiene, and optional styrene-butadiene interpolymer. All individual values and subranges from 25 to 100 phr are included herein and disclosed herein. In a further embodiment, the filler is carbon black.

In a preferred embodiment, the composition does not contain a paraffinic oil. Such oils are not compatible with polyisoprenes (natural rubber), and will migrate to the surface of a part, such as a tire, fabricated from a formulation containing a polyisoprene. This oil migration results in a oily, slippery part.

The EPDM may comprise a combination of two or more embodiments as described herein.

The polyisoprene may comprise a combination of two or more embodiments as described herein.

The polybutadiene may comprise a combination of two or more embodiments as described herein.

Mixing

It is understood that this invention contemplates that the mixing process may occur in sequential stages, with any of the compounding ingredients, other than elastomers (for example, polyisoprene(s), EAODM(s), polybutadiene(s) (optional), and styrene-butadiene interpolymer(s) (optional)), being added in any stage. A common example is the two stage mastication process, wherein all ingredients, except vulcanizing agents and accelerators, are masticated in a first stage, the first stage compound is cooled down, vulcanizing agents and accelerators are added, and the compound is then finished in a second mastication stage. This is done in order to avoid premature vulcanization caused by masticating at high temperatures, in the presence of vulcanizing agents and accelerators.

In one embodiment, the polyisoprene, and EAODM (preferably an EPDM) are mixed dry, without the addition of an extender oil. In one embodiment, the polyisoprene, EAODM (preferably an EPDM) and polybutadiene are mixed dry, without the addition of an extender oil.

In another embodiment, the polyisoprene, and EAODM (preferably an EPDM) are mixed in the presence of an aromatic oil and/or a naphthenic oil.

In another embodiment, the polyisoprene, EAODM (preferably an EPDM) and polybutadiene are mixed in the presence of an aromatic oil and/or a naphthenic oil.

In another embodiment, the polyisoprene and EAODM (preferably an EPDM) are premixed prior to the addition of other components.

One skilled in the art may determine other mixing schemes suitable for use in the invention.

Applications

The compositions of the present invention may be used in preparing any of a variety of articles or manufacture, or their component parts or portions. For purposes of illustration only, and not by way of limitation, such articles may be selected from the group consisting of belts, hoses, tubes, gaskets, membranes, molded goods, extruded parts, adhesives, tires and tire sidewalls, and other automotive parts.

The inventive compositions may contain at least one additive selected from the group consisting of fillers, fibers, plasticizers, oils, colorants, stabilizers, foaming agents, retarders, accelerators, cross-linking agents and other conventional additives.

The inventive compositions may be converted into a finished article of manufacture by any one of a number of conventional processes and apparatus. Illustrative processes include extrusion, calendering, injection molding, compression molding, fiber spinning, and other typical thermoplastic processes.

The invention is particularly useful in the manufacture of tire compounds that comprise a blend of EPDM with one or more highly unsaturated diene elastomers (for example, BR, SBR, NR and IR).

Specially formulated vulcanizable elastomeric compounds, prepared in accordance with the process of this invention, can be extruded through a die to produce elastomeric articles, such as strip stock for the tread, sidewall, and bead filler components of a pneumatic tire, or used to produce sheet stock for the air retention innerliner. Other specially formulated elastomeric compounds, prepared in accordance with this invention, can be calendered onto textile or steel cord fabric, to produce cord-reinforced sheet stock for the carcass and circumferential belt components of the tire.

The "green" or unvulcanized tire is then built by assembling the various components (except circumferential belt and tread) on the surface of a cylindrical drum, radially expanding and axially compressing the assembly, to produce a toroidal shape, then placing the belt and tread components in position around the circumference of the toroid. Finally, the green tire is vulcanized by inflating with high pressure steam, against the inner surface of a closed, heated aluminum mold. In the early stage of the vulcanization process, when the various elastomeric compounds are still soft and flowable, the pressure of the tire against the inner surface of the mold produces the final precise shape, tread pattern, sidewall lettering, and decorative markings. Later, in the vulcanization process, heat-activated crosslinking reactions take place within the various elastomeric compounds, so that when the mold is finally opened, the compound has undergone crosslinking to a degree that is essentially optimum for the intended purpose.

The vulcanizable elastomeric compounds produced by the process can be shaped and vulcanized into an elastomeric article or body. The elastomeric bodies can be readily CO-cured. Accordingly, the present invention includes a process for interfacial CO-curing of shaped elastomeric bodies in mutual contact. The process comprises (i) forming the vulcanizable elastomeric compound into a shaped elastomeric body; (ii) assembling the shaped elastomeric body, so that it contacts another shaped elastomeric body comprising a major portion of a highly unsaturated rubber, to produce an assembly; and (iii) vulcanizing the assembly, under conditions so as to effect substantial crosslinking across an interface between the shaped elastomeric bodies.

Articles can be prepared by injection molding, extrusion, extrusion followed by either male or female thermoforming, low pressure molding, compression molding and the like.

A partial, far from exhaustive, listing of articles that can be fabricated from the compositions of the invention, includes polymer films, fabric coated sheets, polymer sheets, foams, tubing, fibers, coatings, automotive parts (for example, tires and tire components), computer parts, building materials, household appliances, electrical supply housings, trash cans, storage or packaging containers, lawn furniture strips or webbing, lawn mower, garden hose, and other garden appliance parts, refrigerator gaskets, acoustic systems, utility cart parts, desk edging, toys and water craft parts. The compositions can also be used in roofing applications, such as roofing membranes. The compositions can further be used in fabricating a footwear component, including, but not limited to, a shaft for a boot, particularly an industrial work boot. A skilled artisan can readily augment this list without undue experimentation.

DEFINITIONS

Any numerical range recited herein, includes all values from the lower value and the upper value, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. As an example, if it is stated that a compositional, physical or other property, such as, for example, molecular weight, melt index, etc., is from 100 to 1,000, it is intended that all individual values, such as 100, 101, 102, etc., and sub ranges, such as 100 to 144, 155 to 170, 197 to 200, etc., are expressly enumerated in this specification. For ranges containing values which are less than one, or containing fractional numbers greater than one (e.g., 1.1, 1.5, etc.), one unit is considered to be 0.0001, 0.001, 0.01 or 0.1, as appropriate. For ranges containing single digit numbers less than ten (e.g., 1 to 5), one unit is typically considered to be 0.1. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated, are to be considered to be expressly stated in this application. Numerical ranges have been recited, as discussed herein, in reference to density, Mooney viscosity, molecular weights and other properties.

The term "composition," as used herein, includes a mixture of materials, which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

The term "polymer," as used herein, refers to a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term interpolymer as defined hereinafter.

The term "interpolymer," as used herein, refers to polymers prepared by the polymerization of at least two different types of monomers. The generic term interpolymer thus includes copolymers, usually employed to refer to polymers prepared from two different types of monomers, and polymers prepared from more than two different types of monomers.

The terms "blend" or "polymer blend," as used herein, mean a blend of two or more polymers. Such a blend may or may not be miscible (not phase separated at molecular level). Such a blend may or may not be phase separated. Such a blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art.

The term "masticate," and similar terms, as used herein, refers to grinding, crushing and/or reducing in size of the particles of polymeric blends.

The phrase "based on the hundred parts of the elastomers," as used herein, in reference to phr values, refers to hundred parts of the following combination: polyisoprene(s), EAODM(s), optional polybutadiene(s), optional styrene-butadiene interpolymer(s), and optional additional elastomers as described herein.

MEASUREMENTS

Mooney Viscosity

Interpolymer MV (ML 1+4 at 100⁰C) is measured in accordance with ISO 289- 1-94, with a one minute preheat time and a four minute rotor operation time. The instrument is an Alpha Technologies Rheometer MDR 2000.

Interpolymer MV (ML1+4 at 125°C) is measured in accordance with ISO 289- 1-94, with a one minute preheat time and a four minute rotor operation time. The instrument is an Alpha Technologies Rheometer MDR 2000.

For a carbon black filled EAODM (preferably an EPDM) interpolymer, the Mooney Viscosity [MV (ML1+4 at 125⁰C)] for the neat interpolymer (no filler (for example, carbon black) and no oil) can be determined, by one skilled in the art, by one of two methods as described below. The following methods are in reference to carbon black filled interpolymers, however, one skilled in the art could use similar methods for other types of fillers.

Method 1

For a carbon black filled interpolymer (INTA), preferably with no oil, or a known amount of oil (typically less than two weight percent, based on weight of interpolymer) that has a measured viscosity less than 100 [MV (ML1+4 at 125⁰C)], the Mooney viscosity of the neat interpolymer is determined from a calibration curve as follows. The amount of carbon black in the polymerized INT A interpolymer can be determined gravimetrically, for example, by selective ashing of the polymer (plus additives if present), and, if present, oil, in a manner to leave the carbon black intact (for example TGA).

A neat interpolymer, corresponding in chemical make-up to the interpolymer of interest, and prepared from the same or similar catalyst system, and of known Mooney viscosity [MV (ML1+4 at 125⁰C)], is melt blended with various levels of carbon black, and, if needed, the required amount of oil, to form a range of carbon black filled interpolymers. Melt blending can be done in a Brabender mixer. The carbon black and oil used, are the same as that in the interpolymer of interest (INT A). The Mooney viscosity [MV (ML1+4 at 125⁰C)] is measured for each sample, and a calibration curve is generated, showing the measured Mooney viscosity as a function of the amount of carbon black. A series of such calibration curves are generated for several neat interpolymers (no filler, no oil) of varying viscosities. The data from the generated calibration curves is entered into a regression program, such as a MICROSOFT EXCEL regression program, and the following information is generated: a coefficient for the carbon black level, a coefficient for the measured Mooney viscosity, and an intercept.

The Mooney viscosity [MV (ML1+4 at 125⁰C)] of the neat interpolymer of interest can be calculated using the data generated from the regression analysis, the known level of carbon black in the interpolymer (INTA), and the measured Mooney viscosity [MV (ML1+4 at 125⁰C)] of the interpolymer (INT A). Method 2

For a carbon black filled interpolymer (INT B), preferably with no oil, or a known amount of oil (typically less than two weight percent, based on the weight of the interpolymer) that has a viscosity that is determined to be greater than 100 [MV (ML1+4 at 125⁰C)], the Mooney viscosity of the neat polymer is determined from a calibration curve as follows. The amount of carbon black in the polymerized INT B interpolymer can be determined gravimetrically, for example, by selective ashing of the polymer (plus additives if present), and, if present, oil, in a manner to leave the carbon black intact (for example TGA).

A neat interpolymer, corresponding in chemical make-up to the interpolymer of interest, and prepared from the same or similar catalyst system, and of known polymer Mooney viscosity, is melt blended, with a fixed amount of carbon black (for example, from 40 to 60 phr carbon black, based on hundred parts interpolymer), and a fixed amount of an oil (for example, from 60 to 80 phr oil, based on hundred parts interpolymer), to form a first sample. The carbon black and oil used, are the same as that in the interpolymer of interest (INTB). Additional samples are formed, each having an interpolymer of different Mooney viscosity, and each having the same amount of both carbon black and oil. The Mooney viscosity [MV (ML1+4 at 125⁰C)] is measured for each sample. A calibration curve is generated, showing the measured Mooney viscosity [MV (ML1+4 at 125⁰C)] as a function of the Mooney viscosity [MV (ML1+4 at 125⁰C)] of the neat interpolymer (no filler, no oil).

The carbon-black filled interpolymer (INT B) of interest is next compounded with additional carbon black to achieve a final carbon black level as that used in the samples for calibration, as discussed above. Also the INT B interpolymer is compounded with the same oil, and at the same oil level, as that used in the samples for calibration as discussed above, to form a "new compounded INT B" interpolymer. The Mooney viscosity [MV (ML1+4 at 125⁰C)] of the new compounded INT B interpolymer is measured. The Mooney viscosity of the neat interpolymer can be then calculated using the calibration curve as described above.

Density is measured in accordance with ASTM D-792-00. Gel Permeation Chromatography

The average molecular weights and molecular weight distributions for ethylene/α-olefm/diene interpolymers can be determined with a gel permeation chromatographic system, consisting of a Polymer Laboratories, Model 200, series high temperature chromatograph. The column and carousel compartments are operated at 140⁰C for ethylene-based polymers (containing a majority molar amount of polymerized ethylene based on total amount of polymerized monomers). The columns are three Polymer Laboratories, 10-micron, Mixed-B columns. The solvent is 1,2,4 trichlorobenzene. The samples are prepared at a concentration of 0.1 gram of polymer in 50 milliliters of solvent. The solvent, used as the mobile phase, and to prepare the samples, contains 200 ppm of butylated hydroxytoluene (BHT). Ethylene-base polymers are prepared by agitating lightly for two hours, at 160⁰C. The injection volume is 100 microliters, and the flow rate is 1.0 milliliters/minute. Calibration of the GPC column set is performed with narrow molecular weight distribution polystyrene standards, purchased from Polymer Laboratories (UK), with molecular weights ranging from 580 to 8,400,000. The polystyrene standard peak molecular weights are converted to polyethylene molecular weights using the following equation (as described in Williams and Ward, J. Polym. ScL, Polym. Let., 6, 621 (1968)):

^polyethylene ^~ A X (Mp_Oiy_Sty_rene) , where M is the molecular weight, A has a value of 0.4315, and B is equal to 1.0.

Polyethylene equivalent molecular weight calculations are performed using Viscotek TriSEC software Version 3.0.

MRD (Moving Die Rheometer), 0.5° arc, 30 minutes at 16O⁰C, was measured in accordance with ISO 6502:1991.

Tensile Properties, dumbbell T2 at 23°C, were measured in accordance with ISO 37:1994.

Resilience at 23°C (%) was measured in accordance with ISO 4662:1986.

Abrasion Resistance, DIN Volume loss (mm ) was measured in accordance with DIN 5316-1987.

Tear Die C at 23°C, kN/m, was measured in accordance with ISO 34-1 : 1994. Hardness IRHD, 30 sec at 23⁰C, was measured in accordance with ISO 48:1994.

De Mattia Crack Growth was measured in accordance with ISO 133 (1983).

The following examples illustrate, but do not, either explicitly or by implication, limit the present invention. Unless otherwise indicated, all parts and percentages are by weight.

EXPERIMENTAL

NDR 46140 is an ethylene-propylene-ethylidene norbornene (ENB) interpolymer with 58 wt% ethylene, 4.9 wt% ENB, containing 30 p.h.r. of carbon black N650, with M_w = 327000, and viscosity ML(l+4) at 125⁰C = 140 (calculated viscosity of neat polymer (no filler (e.g., carbon black), and no oil)).

Nordel™ IP 4640 is an ethylene-propylene-ethylidene norbornene (ENB) interpolymer with 55 wt% ethylene, 4.9 wt% ENB, with viscosity ML(I +4) at 125⁰C = 40 (neat polymer).

Nordel™ IP 5565 is an ethylene-propylene-ethylidene norbornene (ENB) interpolymer with 50 wt% ethylene, 7.5 wt% ENB, with viscosity ML(I +4) at 125⁰C = 65 (neat polymer).

NDR 47130, an ethylene-propylene-ethylidene norbornene (ENB) interpolymer with 67 wt% ethylene, 4.9 wt% ENB, containing 30 p.h.r. of carbon black N650, with Mw = 308000, and viscosity ML(l+4) atl25°C = 130 (calculated viscosity of neat polymer.

N55 is an ethylene-propylene-ethylidene norbornene (ENB) interpolymer with 58 wt% ethylene, 7.5 p.h.r. ENB, containing 30 p.h.r. of carbon black N650, with viscosity ML(I +4) at 125⁰C = 100 (calculated viscosity of neat polymer.

N 115 is commercially available carbon black (Degussa).

NR is a natural cis-l,4-polyisoprene (natural rubber).

BR is a polybutadiene containing a high cis content, greater than 97 wt% (based on total weight of polymerized monomers), and Mooney Viscosity ML(I +4) at 100⁰C = 40. STRUKTOL 40 MS is a mixture of dark aromatic hydrocarbon resin available from Struktol Company of America.

6PPD is N-(l,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (Vulkanox 4020 from Lanxess).

A suitable wax is Antilux 111 from Rhein Chemie.

TBBS is an accelerant (N-t-butyl-2-benzothiazolsulfenamid), Vulkacit NZ/EG-C from Lanxess.

The sulfur is in a form of powder (elemental sulfur)

A standard truck tread compound formulation (80/20 NR/BR) was used as reference. The NR (20 p.h.r.) was substituted with the same amount of EPDM (4 different grades of EPDM have been tested), and the properties of the compound obtained was measured.

Formulations for Truck Tread Applications are shown in Table 1.

Table 1 : Formulations for Truck Tread Applications - Amounts are in phr, based on hundred parts of the (NR + BR + EPDM)

* NR = SMR 20

For each formulation, components were mixed in a 1.6 liter Intermix mixer, in accordance with the following procedure: (a) first add the polymers (NR+ BR + EPDM) to the mixer, (b) masticate the polymers for 30 seconds,

(c) add oil and/or filler, and mix the resulting combination for 60 seconds,

(d) open the mixer, sweep the ram, and add antioxidant,

(e) close the mixer, and mix for a total time of approximately six minutes, or mix to a maximum temperature of 155⁰C, whichever occurs first, to form a resulting mixture (see Table 2),

(f) drop the resulting mixture onto an open mill, and add curatives, and

(g) mixed curatives into the resulting mixture on the open mill to form the final formulation.

Some mixing parameters are shown in Table 2.

Table 2: Mixing Parameters

Each formulation was transferred into a mold, and cured at 16O⁰C (35 bar pressure), at a time = T90 + 5 minutes (around 12 to 13.5 minutes).

The viscosity and cure properties of the final formulations are shown in Table 3. In Table 3, the rheometer acronyms are defined as follows: MDR= Moving Die Rheometer (the name of the instrument), ML (dNm) = minimum torque, MH (dNm) = maximum torque, TS2= time necessary to reach a torque increase of two units, and T90 = time necessary to reach the 90% of the maximum of the torque (as seen from a torque vs. time curve). Table 3 : Viscosity and Cure Properties

MRD, 0.5° arc, 30 minutes at 160⁰C, measured in accordance with ISO 6502: 1991. Mooney Viscosity ML(I +4), 4 minutes at 100⁰C, measured in accordance with ISO 289- 1 : 1994.

The mechanical properties (after cure) of test specimens formed from the final formulations are shown in Tables 4 and 5.

Table 4: Mechanical Pro erties*

* Tensile Properties, dumbbell T2 at 23°C (ISO 37:1994) Samples were cured at time = T90 + 5 min, with a pressure of 35 bar.

Table 5 : Other Mechanical Properties

For each test, the formulation was cured at 16O⁰C (35 bar pressure), at a time = T90 + 5 minutes (12 to 13.5 minutes), as discussed above.

Resilience at 23°C (%) measured in accordance with ISO 4662:1986.

Abrasion Resistance, DIN Volume loss (mm ) measured in accordance with DIN 5316-1987.

Tear Die C at 23°C, kN/m, measured in accordance with ISO 34-1 : 1994 (Method C, refer to Figure 3 (Crescent test piece die) of this standard).

De Mattia Crack Growth is measured in accordance with ISO 133 (1983).

Hardness IRHD, 30 sec at 23⁰C, measured in accordance with ISO 48:1994.

It has been found, surprisingly, that when high molecular weight (M_w, or Mooney Viscosity as specified) EPDM, NDR 46140 (Example 2), was used in the rubber formulation, the tear and the tensile properties (modulii and tensile strength) were improved, as compared to a formulation which contained the low molecular weight grade EPDM (NORDEL™ IP 4640 - Comparative Example 2). Also, the tear resistance and abrasion resistance of Example 2 were similar to those of the reference formulation (Comparative Example 1). Example 2 provides the additional benefit of improved rolling resistance (as compared to Comp. 1 and Comp.2), as indicated by its resilience, which is an important property for truck tread applications. Due to the saturated backbone of an EPDM, an improvement in oxidative resistance of the blend would also be expected. With a high molecular weight, gas phase EPDM, it is possible to substitute some of the NR, for example, 20 phr of NR, with the same amount of a neat EPDM (for example, a formulation comprising 60 phr NR + 20 phr EPDM (neat) + 20 phr BR), and obtain better tear and tensile properties, compared to a formulation containing a low molecular weight EPDM, and obtain similar tear resistance and abrasion resistance compared to the reference formulation without the EPDM (80 phr NR + 20 phr BR)

The substitution of NR (for example, 20 phr) with the same amount of an EPDM polymer (neat; in order to substitute 20 weight units of NR, one must use 26 weight units of NDR 46140 (equivalent to 20 weight units of polymer and 6 weight units of carbon black)), will lead to better oxidative and heat resistance, and lower hystheresis (lower heat build-up and lower rolling resistance), while maintaining abrasion resistance and tear resistance. Each of these properties is compared to a similar composition without the EPDM substitution.

Although the invention has been described in certain detail through the preceding specific embodiments, this detail is for the primary purpose of illustration. Many variations and modifications can be made by one skilled in the art, without departing from the spirit and scope of the invention, as described in the following claims.

Claims

Claims:

1. A composition comprising the following: a) at least one polyisoprene, and b) at least one ethylene/α-olefϊn/diene (EAODM) interpolymer, and wherein the at least one EAODM has a Mooney viscosity, ML(I +4) at

125⁰C, greater than 60.

2. The composition of Claim 1, wherein the at least one EAODM is an EPDM interpolymer.

3. The composition of Claim 1 or Claim 2, wherein the at least one polyisoprene is a natural polyisoprene or a synthetic polyisoprene.

4. The composition of any of Claims 1-3, wherein the EAODM has a Mooney Viscosity, ML(l+4) at 125⁰C, greater than 60 to 200.

5. The composition of any of Claims 1-4, further comprising at least one polybutadiene.

6. The composition of Claim 5, wherein the at least one polybutadiene contains a high cis content of greater than 97 weight percent.

7. The composition of Claim 5 or Claim 6, wherein the at least one polybutadiene has a Mooney viscosity, ML(l+4) at 100⁰C, from 20 to 80.

8. The composition of any of the preceding claims, wherein the at least one polyisoprene is present in an amount from greater than, or equal to, 20 phr, based on hundred parts of the sum of the polyisoprene, EAODM, and optional polybutadiene.

9. The composition of any of the preceding claims, wherein the at least one polyisoprene is derived from a non-granular, bale form.

10. The composition of any of the preceding claims, wherein the at least one EAODM is present in an amount less than, or equal to, 80 phr, based on hundred parts of the sum of the polyisoprene, EAODM, and optional polybutadiene.

11. The composition of any of the preceding claims, wherein the at least one EAODM is present in an amount greater than, or equal to, 10 phr, based on hundred parts of the sum of the polyisoprene, EAODM, and optional polybutadiene.

12. The composition of any of the preceding claims, wherein the at least one EAODM has a weight average molecular weight, M_w greater than 176,000 g/mole.

13. The composition of any of the preceding claims, wherein the at least one EAODM contains no oil.

14. The composition of any of the preceding claims, wherein the at least one EAODM contains from 1 to 50 phr of carbon black, based on hundred parts of the sum of the polyisoprene, EAODM, and optional polybutadiene.

15. The composition of any of the preceding claims, wherein the at least one EAODM has ethylene content greater than, or equal to, 40 weight percent, based on the total weight of polymerized monomers.

16. The composition of any of the preceding claims, wherein the at least one EAODM has ethylene content from 40 weight percent to 95 weight percent, based on the total weight of polymerized monomers.

17. The composition of any of the preceding claims, wherein the at least one EAODM has a diene content from 2 weight percent to 12 weight percent, based on the total weight of polymerized monomers.

18. The composition of any of the preceding claims, wherein the EAODM is a homogeneously branched linear interpolymer or a homogeneously branched substantially linear interpolymer.

19. The composition of any of the preceding claims, wherein the EAODM is a homogeneously branched substantially linear interpolymer.

20. The composition of any of the preceding claims, wherein the at least one polyisoprene is a natural cis-l,4-polyisoprene.

21. The composition of any of the preceding claims, wherein the at least one polyisoprene is a synthetic cis-l,4-polyisoprene.

22. The composition of any of the preceding claims, wherein the at least one polyisoprene has a Mooney viscosity, ML(l+4) at 100⁰C, from 20 to 80.

23. The composition of any of the preceding claims, wherein the EAODM contains at least one diene selected from the group consisting of 5-ethylidene-2- norbornene, dicyclopentadiene and 1,4-hexadiene.

24. The composition of any of the preceding claims, further comprising at least one filler.

25. The composition of Claim 24, wherein the at least one filler is selected from the group consisting of silica; carbon black; clay; titanium dioxide; silicates of aluminum, magnesium, calcium, sodium, potassium and mixtures thereof; carbonates of calcium, magnesium and mixtures thereof; oxides of silicon, calcium, zinc, iron, titanium, and aluminum; sulfates of calcium, barium, and lead; alumina trihydrate; magnesium hydroxide and mixtures thereof.

26. The composition of any of the preceding claims, wherein the EAODM has a molecular weight distribution (M_w/M_n) less than 5.

27. The composition of any of the preceding claims, further comprising at least one additive selected from the group consisting of a pigment, a flame retardant, a scratch and mar resistant additive, and combinations thereof.

28. The composition of any of the preceding claims, further comprising one or more other ethylene/α-olefm interpolymers.

29. An article, comprising at least one component formed from the composition of any of the preceding claims.

30. The article of Claim 29, wherein the article is in an automotive part.

31. The article of Claim 29, wherein the article is a tire.

32. The article of Claim 29, wherein the article is an engine mount.

33. The article of Claim 29, wherein the article is a belt.

34. The article of Claim 29, wherein the article is a building or construction material.

35. A method of making a polymeric formulation, said method comprising mixing a composition comprising at least one polyisoprene, at least one EAODM polymer, and optionally, at least one oil and/or filler, and wherein the at least one EAODM has a Mooney viscosity, ML(l+4) at 125⁰C, greater than 60.

36. The method of Claim 35, wherein the at least one oil is selected from the group consisting of aromatic oils and naphthenic oils.