MXPA00002010A - Elastomers with improved processability - Google Patents

Abstract

A process for improving the green strength of ethylene/a-olefin/diene polymers is described comprising (A) selecting an ethylene/a-olefin/diene polymer having a Mooney viscosity at 125 C up to about 80 and a percent gel (%gel) up to about 30 percent and (B) partially cross-linking the ethylene/a-olefin/diene polymer selected in step (A) to make a modified ethylene/a-olefin/diene polymer satisfying the equations MV2100 and (I) wherein MV is the Mooney viscosity of the modified polymer, MS1 is the melt strength in centiNewtons of the polymer selected in step (A) at 110 C, when formulated according to ASTM D3568#2, MS2 is the melt strength in centiNewtons of the modified polymer produced by step (B) measured under the same conditions, and W is 0.3. Modified ethylene/a-olefin/diene polymers obtainable according to the above process or satisfying the equation (II), are also described in which MS2, MV and%gel of the modified polymer are defined as defined above, X is 50, Y is 20, and Z is 40. Further described is a process for making an article comprising an ethylene/a-olefin/diene polymer and intermediates for making the modified ethylene/a-olefin/diene polymers.

Description

ELASTOMERS WITH IMPROVED PROCESSING CAPACITY This invention relates to processes for modifying elastomers, the modified elastomers made therefrom, and processes for manufacturing products of the modified elastomers. The term "elastomer" was first defined in 1940 to describe synthetic thermosetting high polymers that have properties similar to vulcanized natural rubber, e.g., which has the ability to stretch at least to its original length and contract very rapidly to approximately its original length when they are released. Representative "higher polymers" were styrene-butadiene copolymer, polychloropropene, butyl nitrite rubber, and ethylene-propylene polymers (aka EP elastomers and EPDM). The term "elastomers" was then extended to include non-interlaced thermoplastic polyolefins, ie, TPO. ASTM D 1566 defines several physical properties of elastomers, and test methods to measure these properties. US-A-5,001,205 provides a general review of known elastomers comprising ethylene copolymerized with α-olefin. As described herein, commercially available elastomers have several minimum properties, e.g., a Mooney viscosity of not less than 10, a weight average molecular weight (Mp) of not less than 1 10,000, a glass transition temperature. less than -20 ° C, and a degree of crystallization not greater than 25%. A dilemma faced in the production of commercially available cured elastomers is that the high weight average molecular weight is generally desired to improve physical properties such as tensile strength, stiffness, compression, setting, etc. , in the cured product, but uncured high molecular weight elastomers are more difficult to process than their low molecular weight counterparts. In particular, uncured high molecular weight elastomers are usually more difficult to isolate from residual solvents and monomers after the polymerization of the elastomer. Uncured high molecular weight elastomers are also usually more difficult to extrude at high rates, since these generally tend to fracture by shear at low extrusion rates and require more power consumption by means of polymer processing equipment such as mixers in batches, continuous mixers, extruders, etc. , and cause increased wear on parts of such equipment exposed to high shear stresses, such as expensive extruder components. These disadvantages reduce production regimes and / or increase the cost of production. A conventional test to solve this dilemma is to produce a relatively low molecular weight elastomer and subsequently completely interlace the final product to obtain the desired tensile strength, stiffness, compression, etc. A disadvantage of this approach is that the low molecular weight elastomer also generally corresponds to a low "resistance before treatment" (i.e., strength before entanglement). This disadvantage is particularly noticeable in applications such as wire and cable coatings, continuous packaging extrusion, etc., where the low strength before the treatment results in uneven flexures or polymer thickness. The present invention addresses these and other disadvantages. This invention provides a process for improving the strength before the treatment of ethylene / α-olefin / diene polymers comprising: (A) selecting an ethylene / α-olefin / diene polymer having a viscosity of Mooney ML1 + 4, measured in accordance with ASTM D1646 at 125C, above about 80 and a percentage gel (% gel), measured in accordance with ASTM D 2765, procedure A, above about 30 percent, and (B) partially crosslink the ethylene polymer / a -olefin / diene selected in step (A) to make an ethylene / α-olefin / diene polymer satisfying the following equations: MV < 100 V = 100 where MV is the Mooney viscosity of the modified polymer measured as defined above, MS-i is the melt strength in centiNewtons of the polymer selected in step (A) at 110 ° C, when formulated in accordance with ASTM D 3568 # 2, MS2 is the melting strength in centiNewtons of the modified polymer produced by step (B) measured under the same conditions, and W is 0.3. Another aspect of this invention are the modified ethylene / α-olefin / diene polymers which are obtained according to the above process, preferably when they comply with the equation: wherein MS2, MV and% gel of the modified polymer are measured as defined above, X is 50, Y is 20, and Z is 40. This invention also provides a process for making an article comprising an ethylene polymer / α-olefin / diene comprising: (A1) melt processing of the modified polymer described above; (B1) forming the product of step (A1) in one configuration; and (C1) curing the product of step (B1) to form an article comprising an entangled ethylene / α-olefin / diene polymer. This invention also provides intermediates for manufacturing ethylene / α-olefin / modified diene polymers according to the above process comprising a polymer selected in accordance with step (A) in combination with unreacted peroxide crosslinking agent in an appropriate amount to modify the selected polymer according to that process under melting process conditions. This invention also provides another process for manufacturing an article comprising an ethylene / α-olefin / diene polymer comprising: (A1) a fusion process of the above intermediate; (Bl) formation of the product of step (A1) in one form; and (C1) cutting the product of step (B1) to form an article comprising an ethylene / α-olefin / linked diene polymer. Unless otherwise indicated, all parts, percentages and relationships are by weight. The expression "up" when used to specify a numerical regime includes any value less than or equal to the numerical value which follows this expression. The expression "% by weight" which means "percent by weight". The term "linkage" as used herein refers to tetrafunctional long chain branching (type H) resulting from a covalent bond between two base structures of polymer molecules and long chain trifunctional branching (T-type) produced when a terminal group of one polymer molecule forms a covalent bond with the base structure of another polymer molecule.

The term "gel" refers to a network of three-dimensional polymers which are formed from covalently entangled polymer chains. The amount of gel is expressed in terms of percent by weight based on the total weight of the polymer as determined by ASTM D2765, Procedure A. The term "melt strength" refers to the strength of the elastomer measured in centiNewtons at 110 ° C. when formulated in accordance with ASTM D3568 # 2 according to a procedure described in more detail in the subsequent examples. Unless specified otherwise, the term "Mooney viscosity" as used herein, means viscosity which is measured in accordance with ASTM D1646 using a shear rheometer at 125 ° C and measured according to ML 1 + 4. The ethylene / α-olefin / diene polymers used to make rheology modified polymers according to this invention are polymers of ethylene (CH2 = CH2) with at least one C3-C20 aliphatic α-olefin and at least one diene of C4-C2o- The diene can be conjugated or unconjugated. Examples of the C3-C20 aliphatic α-olefins include propene, 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene , 1-octadecene and 1-eicosene. The α-olefin may also contain a cyclic structure such as cyclohexane or cyclopentane, which results in an α-olefin such as 3-cyclohexyl-1-propene (allylocyclohexane) and vinyl cyclohexane. Examples of non-conjugated dienes include aliphatic dienes such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 2-methyl-1,5-hexadiene, 6-heptadiene, 6-methyl-, 5-heptadiene. , 1,6-octadiene, 1,7-octadiene, 7-methyl-1,6-octadiene, 1,3-tetradecadiene, 1,16-eicosadiene, and the like; cyclic dienes such as 1,4-cyclohexadiene, bicyclo [2.2.1] hept-2,5-diene, 5-ethyldiene-2-norbornene (ENB), 5-methylene-2-norbornene, 5-vinyl 2- norbornene, bicyclo [2.2.2] oct-2,5-diene, 4-vinylcyclohex-1-ene, bicyclo [2.2.2] oct-2,6-diene, 1,7,7-trimethylbicyclo- [2.2.1] ] hept-2,5-diene, dicyclopentadiene, eti-te tra hydro indene, 5-allylbicyclo [2.2.1] hept-2-ene, 1, 5-cyclooctadiene, and the like; aromatic dienes such as 1,4-dial lylbenzene, 4-allyl-1 H-indene; and threes such as 2,3-diisopropenyldiene-5-norbornene, 2-ethyldiene-3-isopropyldiene-5-norbornene, 2-propenyl-2,5-norbornadiene, 1,3,7-octatriene, 1,4,9- decatriene, and the like; with 5-ethyldiene-2-norbornene a preferred non-conjugated diene. Examples of conjugated dienes include butadiene, isoprene, 2,3-dimethylbutadiene-1,3, 1, 2-dimethylbutadiene-1,3, 1,4-dimethylbutadiene-1,3-ethylbutadiene-1,3, 2-phenylbutadiene-, 3 , hexadiene-1, 3, 4-methylpentadiene-1,3,3-pentadiene (CH3CH = CH-CH = CH2; commonly called piperylene), 3-methyl-1,3-pentadiene, 2,4-dimethyl-1 , 3-pentadiene, 3-ethyl-1,3-pentadiene, and the like; with 1, 3-pentadiene a preferred conjugated diene.

Exemplary polymers include ethylene / propylene / -5-ethyldiene-2-norbornene, ethylene / 1-o -tene / 5-ethylidene-2-norbornene, eti len or / pro-pyle or / 1,3-pen tadiene, and ethylene / 1 -octene / 1, 3-pen tadieno. Exemplary tetrapolymers include ethylene / propylene / 1-octene / diene (e.g. ENB) and ethylene / propylene / mixed dienes, e.g., ethylene / propylene / 5-ethylidene 2-norbornene / pperylene. In addition, the elastomers may include smaller amounts, e.g., 0.05-0.5 weight pnt, of increases in long chain branches, such as 2,5-norbornadiene (aka bicyclo [2.2.1] hepta-2). , 5-diene), diallybenzene, 1,7-octadiene (H2C = CH (CH2) 4CH = CH2), and 1,9-decadiene (H2C = CH (CH2) 6CH = CH2). In a general minimum, the selected ethylene / α-olefin / diene polymers are derived from at least about 30, preferably at least about 40, and more preferably at least about 50, pnt by weight of ethylene; at least about 15, preferably at least about 20 and more preferably at least about 25, weight pnt of at least one α-olefin; and preferably at least about 0.1, and more preferably about 0.5 pnt by weight of at least one conjugated and unconjugated diene. At a general maximum, the ethylene / α-olefin / diene polymers selected for modification according to this invention comprise no more than about 75 weight pnt ethylene; not more than about 70, preferably not more than 60, and more preferably not more than about 55, weight pnt of at least one α-olefin; and no more than about 20, preferably no more than about 15 and more preferably no more than about 12, weight pnt of at least one conjugated or non-conjugated diene. All weight pntages are based on the weight of the elastomer which can be determined using any conventional method. The polydispersity (molecular weight distribution or Mp / Mn) of the selected polymer prior to the modification generally ranges from about 1.5, preferably about 1.8, and especially about 2.0, to about 1.5, preferably about 10, and especially around of 6. Determination of molecular weight distribution The whole interpolymer product samples and the individual interpolymer components are analyzed by means of gel permeation chromatography (CPG) on a Waters 150C high temperature chromatographic unit equipped with three columns of porosity mixed (polymer laboratories 103,104,105, and 106), which operate in a temperature system of 140 ° C. The solvent is 1, 2,4-trichlorobenzene, of which 0.3 pnt by weight of solutions of the samples are prepared by injection. The flow rate is 1.0 milliliters / minute and the injection size is 100 microliters. The molecular weight determination is deduced using normal narrow molecular weight distribution polystyrene (from Polymer Laboratories) in conjunction with its elution volumes.

Molecular equivalent polyethylene weights are determined using appropriate Mark-Houwink coefficients for polyethylene and polystyrene (as described by Williams and Ward in Journal of Polymer Science, Polymer Letters, Vol. 6 (621) 1968) to derive the following equation: • Vt polyethylene-3 (Ivl polystyrene) • In this equation, a = 0.4316 and b = 1.0. The molecular weight average, Mp, and an average number of molecular weight, Mn, is calculated in the usual way according to the following formula: Mj = (SPl (M \)) 1: Where p, is the fraction of weight of molecules with molecular weight M, eluting from the column of CPG in fraction i and J = 1 when calculating Mp and j = -1 when calculating Mn. Generally the Mp of the interpolymer elastomers ranges from about 10,000, preferably about 20,000, more preferably about 40,000, and especially about 60,000 to about 1., 000,000, preferably around 800,000, more preferably around 600,000, and especially around 500,000. The polymers selected by the mocation cover a scale of viscosities, depending on their molecular weight. The Mooney viscosity for the selected polymers prior to mocation according to this invention preferably ranges from a minimum of about 1, more preferably at least about 5, even more preferably at least about 10, and especially so less about 15, above a maximum of about 80, more preferably above about 65, even more preferably up to about 55, and especially up to about 45. The density of the elastomers is measured in accordance with ASTM D-792 , and these densities range from a minimum of about 0.850 grams / cubic centimeters (g / cm3), preferably around 0.853 g / cm3, and especially around 0.855 g / cm3, to a maximum of about 0.895 g / cm3, preferably about 0.885 g / cm3, and especially about 0.875 g / cm3. The polymers selected for mocation have a gel percent (% gel), measured in accordance with ASTM D2765, Procedure A, up to about 30, preferably up to about 20, more preferably up to about 10 and even more preferably up to about of 5, percent. The ethylene / α-olefin / diene polymer can be selected from any of those known in the art and / or commercially available, including heterogeneously branched, such as those produced using Ziegler-Natta type catalyst, and those which are homogeneously branched . Examples include ethylene / α-olefin / diene polymers available from DuPont Dow Elastomers LLC, such as NORDEL® and NORDEL® IP, for example NORDEL® 1040 and NORDEL® 1070 (each 53% by weight of ethylene, 44% by weight of propylene, and 3% by weight of, 4-hexadiene (HD) derived from EPDM), and those available from Exxon under the name of VISTALON ™, for example VISTALON ™ 2504 (1% by weight of ethylene, 45% by weight of propylene and 5% by weight of ethylidene norbornene (ENB) derived from EPDM). The NORDEL® elastomers and how to make them are described, for example, in the patent of E.U.A. Nos.2,933,480; 3,063,973; 3,093,620. In a preferred embodiment, the selected ethylene / α-olefin / diene polymer branches homogeneously. In such a preferred embodiment, the selected polymer is obtainable by (1) contacting in a reactor (a) ethylene, (b) at least one aliphatic C3-C20 α-olefin, (c) at least one diene, (d) a catalyst, the catalyst comprising (i) a metallocene complex or single site catalyst and (ii) at least one activator, and (e) a diluent and (2) isolating the polymer product.

These include, for example, NORDEL® IP elastomers from DuPont Dow Elastomers L.L.C. Metallocene complexes (single site catalysts) and methods for their preparation are described in EP-A 416,815 and EP-A 514,828 as well as in US Patents. 5,470,993, 5,374,696, 5,231,106, 5,055,438, 5,057,475, 5,091,352, 5,096,867, 5,064,802, 5,132,380, 5,153,157, 5,183,867, 5,198,401, 5,272,236, 5,278,272, 5,321,106, 5,470,993, and 5,486,632. Particularly preferred among the single site catalysts are restricted geometry catalysts from The Dow INSITE ™ Technology. In EP-A-514,828, certain borane derivatives of the above metallocene complex catalysts are described and a method for their preparation and claimed in the patent of E.U.A. 5,453,410 combinations of cationic metallocene complex catalysts with an alumoxane were described as suitable olefin polymerization catalysts. Preferred catalyst compositions comprise: a1) a metal complex corresponding to the formula: ZLMXpX'q 'which has been or subsequently becomes catalytically active by combination with an activating cocatalyst or by use of an activation technique, wherein M is a metal of Group 4 of the Periodic Table of the Elements which has an oxidation state of +2, +3 or +4, joined in a binding mode? 5 that to L; L is a cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, tetrahydrofluoroenyl, or octahydrofluoroenyl group covalently substituted with at least one divalent moiety, Z, and L can further be substituted with 1 to 8 substituents independently selected from the group consisting of hydrocarbyl groups, halo, halohydrocarbyl, hydrocarbyloxy, dihydrocarbylamide, dihydrocarbylphosphine or silyl containing up to 20 non-hydrogen atoms; Z is a divalent moiety linked to L and M via s-unions, said Z comprising boron, or a member of group 14 of the Periodic Table of the Elements, and optionally, also comprises nitrogen, phosphorus, sulfur or oxygen; X is a group of anionic or dianionic ligands having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, from groups of ligands attached to p; X 'independently each time it is presented is a neutral Lewis base ligand compound, having up to 20 atoms; p is 0, 1 or 2; and is twice less than the formal oxidation state of M, with the proviso that when X is a group of dianionic ligands, p is 1; and q is 0, 1 and 2; said metal complex becoming catalytically active by the combination with an activation cocatalyst or use of an activation technique; or a catalyst composition comprising a cationic complex a2) corresponding to the formula (ZLM * X * P +) * A ", wherein: M * is a metal of group 4 of the Periodic Table of the Elements having a state of oxidation of +3 or +4, linked in a? 5 to L mode; L is a cyclopentadienyl, indenyl, tetrahydroindenyl, fluorenyl, tetrahydrofluoroenyl group, or can be substituted with from 1 to 8 substituents independently selected from the group consisting of hydrocarbyl groups halo, halohydrocarbyl, hydrocarbyloxy, dihydrocarbylamino, dihydrocarbylphosphine or silyl containing up to 20 non-hydrogen atoms; Z is a divalent moiety linked to L and M * via s-unions, said Z comprising boron, or a member of Group 4 of the Periodic Table of the Elements, and also optionally comprising nitrogen, phosphorus, sulfur or oxygen; X * is a group of anionic ligands having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalised, groups of p binding ligands; p * is 0 or 1, and is three times smaller than the formal oxidation state of M; and A "is an inert non-coordinating anion.The preferred groups of X 'and X" when M is a metal of Group 4 of the Periodic Table of the Elements and has an oxidation state of +3 or +4 are alkyl groups, aryl, silyl, germyl, aryloxy, or alkoxy having up to 20 non-hydrogen atoms. Additional compounds include phosphines, especially trimethylphosphine, triethylphosphino; triphenylphosphine and bis (1,2-dimethylphosphino) ethane; BY 3; ethers, especially tetrahydrofuran; amines, especially pyridine, bipyridine, tetramethylethylenediamine (TMEDA), and triethylamine; olefins, and conjugated dienes having from 4 to 40 carbon atoms. The complexes that include the last group X 'include those in which the metal is in the formal oxidation state +2. All references to the Periodic Table of the Elements herein refer to the Periodic Table of the Elements, published and copyrighted by CRC Press, Inc., 1989.

Also, any reference to a group or groups will be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups. The Zwitterionic complexes result from the activation of a hydrocarbyl, halohydrocarbyl, or silyl substituted derivative of complexes with Group 4 metal dienes thereof, said X 'having from 4 to 40 atoms which are not hydrogen, and which are not coordinated with the metal in such a way that they form a metallocyclopentene with same where the metal is in the formal +4 oxidation state, by the use of a Lewis acid activation cocatalyst, especially tris (perfluoroaryl) borane compounds. These Zwiterionic complexes are believed to correspond to the formula: where: M "is a Group 4 metal in the formal oxidation state +4; L and Z are as previously described: X" is the divalent remnant of the conjugated diene, X ', formed by the ring opening in a carbon to the metal bonds of a metallocyclopentene; and A 'is the derivative portion of the activation cocatalyst.

As used herein, the "non-coordinating non-coordinating anion" recitation means that it is an anion which does not coordinate to component a1) or which is only weakly coordinated with it remaining sufficiently labile to travel through a neutral Lewis base . A compatible, non-coordinating anion refers specifically to a compatible anion which when functioning as a charge balance anion in the catalyst system of this invention, does not transfer an anionic substituent or fragment thereof to said cation so that it forms a neutral four-coordinate metallocene and a neutral metal by-product. "Compatible anions" are anions which are not degraded by neutrality when the initially formed complex decomposes and does not interfere with the desired subsequent polymerizations. The preferred metal complexes a1) used according to the present invention are complexes corresponding to the formula: wherein: R independently each time it is presented is a group selected from hydrogen, hydrocarbyl, halohydrocarbyl, silyl, germyl, and mixtures thereof, said group containing up to 20 non-hydrogen atoms; M is titanium, zirconium or hafnium; Z is a divalent moiety comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or oxygen, said portion having up to 60 non-hydrogen atoms; X and X 'are as previously defined; p is O, 1 or 2; and q is 0 or 1; with the condition of; when p is 2, q is 0, M is in the formal oxidation state +4, and X is an anionic ligand selected from the group consisting of halide, hydrocarbyl, hydrocarbyloxy, di (hydrocarbyl) amido, di (hydrocarbyl) phosphide, hydrocarbyl sulfide , and silyl, as well as derivatives substituted with halo, di (hydrocarbyl) amino, hydrocarbyloxy and di (hydrocarbyl) phosphino, thereof, said group X having up to 20 non-hydrogen atoms, when p is 1, q is 0, M is in the formal oxidation state +3, and X is a group of stabilizing anionic ligands selected from the group consisting of allyl, 2- (N, N-dimethylaminomethyl) phenyl, and 2- (N, N- dimethyl) aminobenzyl, or M is in the formal oxidation state +4, and X is a divalent derivative of a conjugated diene, M and X together form a metallocyclopentane group, and when p is 0, q is 1, M is in the formal oxidation state +2, and X 'is a neutral, conjugated or non-conjugated diene, optionally substituted with one or more hydride groups rocarbyl, said X 'having up to 40 carbon atoms and forming a complex of p with M. The most preferred coordination complexes a1) used according to the present invention are complexes corresponding to the formula: wherein: R independently each time it occurs is hydrogen or C? -6 alkyl; M is titanium; And it is -O-, -S-, NR * -, -PR * -; Z * is SiR * 2, CR * 2, SiR * 2SR * 2l CR * 2CR * 2, CR * = CR *, CR * 2SiR * 2, or GeR * 2, R * each time it is presented is independently hydrogen, or a selected member of hydrocarbyl, hydrocarbyloxy, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, and R * having up to 20 non-hydrogen atoms, and optionally, two R * groups of Z (when R * is not hydrogen), or a group R * of Z and a group R * of Y forms a ring system; p is 0, 1 or 2; q is 0 or 1; with the condition of; when p is 2, q is 0, M is in the formal oxidation state +3, and X is independently each time methyl or benzyl occurs, when p is 1, q is 0, M is in the formal oxidation state +3, and X is 2 (N, N-dimethyl) aminobecil); or M is in the formal oxidation state +4 and X is 1.4 butadienil, and when p is 0, q is 1, M is in the formal oxidation state +2, and X 'is 1,4-diphenyl-1,3-butadiene or 1,3-pentadiene. The last diene is illustrative of dimene groups without symmetry which result in production of metal complexes which are currently mixtures of the respective geometric isomers. Illustrative metal complexes of constrained geometry are described in International Patent Publication WO 97/26297, particularly on pages 25-28. The complexes can be prepared by the use of known synthetic techniques, a preferred process for preparing the metal complexes is described in E.U.A-A-5,491, 246. The reactions are conducted in a suitable non-interfering solvent at a temperature from -100 to 300 ° C, preferably from -78 to 100 ° C, more preferably from 0 to 50 ° C. A reducing agent can be used to cause The metal M is reduced from a high oxidation state to a lower one, Examples of suitable reducing agents are alkali metals, alkaline earth metals, aluminum and zinc, alkali metal alloys or alkaline earth metals such as amalgam. sodium / mercury and sodium / potassium alloy, sodium naphthalenide, sodium graphite, lithium alkyls, lithium or potassium alkadienyls, and Grignard reagents The appropriate reaction medium for complex formation includes aliphatic and aromatic hydrocarbons , ethers, and cyclic ethers, particularly branched chain hydrocarbons such as isobutane, butane, pentane, hexane, heptane, octane, and mixtures thereof; hydrocarbons c cyclic and alicyclic such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof; hydrocarbyl substituted aromatic and aromatic compounds such as benzene, toluene, and xylene, dialkyl ethers of C 1-4, dialkyl ether derivatives of C? .4 of (poly) alkylene glycols, and tetrahydrofuran. Mixtures of the above are also suitable. Suitable activating cocatalysts useful in the combination with component a1) are the compounds capable of the abstraction of a substituent X of a1) to form an inert counter-ion that does not interfere, or which forms a zwitterionic derivative of a1). Activation catalysts suitable for use herein include perfluorinated tri (aryl) boron compounds, and more especially tris (pentafluorophenyl) borane; non-polymeric, compatible, noncoordinating, ion-forming compounds (which include the use of such compounds under oxidation conditions), especially the use of ammonium, phosphonium, ozone, carbonium, silyl or sulfonium salts of compatible, non-coordinating anions , and ferritinium salts of non-coordinating compatible anions. Suitable activation techniques include the use of volume electrolysis (explained in more detail hereafter). A combination of the above activating cocatalysts, and techniques, can also be employed. The above activation catalysts and activation techniques have been previously explained with respect to the different metal complexes in the following references: US-A-5,153,157, US-A-, 164,802, US-A-5,278,119, US-A-5,407,884 , US-A-5, 483,014, US-A-5,321,106, and EP-A-520,732. More particularly, suitable ion formation compounds useful as catalysts comprise a cation which is a Bronsted acid capable of donating a proton, and a compatible, non-coordinating anion, A; Preferred anions are those that contain a single coordination complex comprising a metal or metalloid center containing the charge whose anion is capable of balancing the charge of the active catalyst species (the metal cation) which can be formed when they combine two components. As wellsaid anion must be sufficiently labile to displace olefinic, diolefinic and acetylenically unsaturated compounds or other Lewis bases such as ethers or nitrites. Suitable metals include, but are not limited to, aluminum, gold and platinum. Suitable metalloids include, but are not limited to, boron, phosphorus, and silicon. Compounds containing anions which comprise coordination complexes containing a single metal or metalloid atom are, of course, well known and many, particularly such compounds containing a single boron atom in the anion portion, are commercially available. Preferably, such cocatalysts can be represented by the following formula: (L "-H) d" (A) d_ where: L "is a neutral Lewis base; (L "-H) is a Bronsted acid; (A) d" is a non-coordinating compatible anion that has a charge of d-, and d is an integer of 1-3. More preferably (A) d "corresponds to the formula: [M'Q4]" wherein: M 'is boron or aluminum in the formal oxidation state +3; and Q independently, each time it is presented, is selected from hydride, dialkylamido, halide, hydrocarbyl, hydrocarbyloxide, halohalo substituted hydrocarbyl, halosubstituted hydrocarbyloxy, and halosuchiuido silylhydrocarbyl radicals (including perhalogenated, hydrocarbyl perhalogenated, hydrocarbyloxy and silylhydrocarbyl perhalogenated radicals), said Q having up to 20 carbons with the proviso that in no more than one occurrence Q is halide. Examples of suitable hydrocarbyloxy Q groups are described in US-A-5,296,433. In a more preferred embodiment, d is 1, that is, the counter ion has a simple negative charge and is A ': Activation cocatalysts comprising boron, which are particularly useful in the preparation of catalysts of this invention can be represented by the following general formula: (L "-H) + (BQ4) -, where: L * is as previously defined, B is boron in a formal oxidation state of 3, and Q is a hydrocarbyl group, hydrocarbyloxy, fluorinated hydrocarbyl, fluorinated hydrocarbyloxy, or fluorinated silylhydrocarbyl of up to 20 non-hydrogen atoms, with the proviso that not more than one occasion Q is hydrocarbyl, More preferably, each time Q is presented is a fluorinated allyl group, especially a pentafluorophenyl group Illustrative but not limiting examples of the boron compounds, which can be used as an activating cocatalyst in the preparation of the improved catalysts of this invention are salts of trisubstituted ammonium such as: trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, tripropylammonium tetrakis (pentafluorophenyl) borate, tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) borate tri) (sec-butyl) ammonium, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium n-butyltris (pentafluorephenyl) borate, N, N-dimethylanilinium benzyltris (pentafluorophenyl) borate, tetrakis (4- ( N, N-dimethylanilinium) -2,3,5,6-tetrafluorophenyl) borate, N-N-dimethylanilinium tetrakis (4- (triisopropylsilyl) -2,3,5,6-tetrafluorophenyl) borate, pentafluorophenoxytryl (pentafluorophenyl) N, N-dimethylanilinium borate, N, N-diethylanilinium tetrakis (pentafluorophenyl) borate, N, N-dimethyl-2,4,6-trimethylanilinium tetrakis (pentafluorophenyl) borate, tetrakis (2,3,4,6) -tetrafluorophenyl) trimethylammonium borate, tetrakis (2,3,4,6-tetrafluorophenyl) borate of triethylammonium or, tetra (2,3,4,6-tetrafluorophenyl) borate of tripropylammonium, tetrakis (2,3,4,6-tetrafluorophenyl) borate of tri (n-butyl) ammonium, tetrakis (2,3,4,6- tetrafluorophenyl) borate of dimethyl (t-butyl) ammonium, tetrakis (2,3,4,6-tetrafluorophenyl) borate of N, N-dimethylanilinium, tetrakis (2,3,4,6-tetrafluorophenyl) borate of N, N- diethylanilinium, and N, N-dimethyl-2,4,6-trimethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) borate; disubstituted ammonium salts such as: di- (i-propyl) ammonium tetrakis (pentafluorophenyl) borate, and dicyclohexylammonium tetrakis (pentafluorophenyl) borate; trisubstituted phosphonium salts such as: triphenylphosphonium tetrakis (pentafluorophenyl) borate, tri (o-tolyl) phosphonium tetrakis (pentafluorophenyl) borate, and tri (2,6-dimethylphenyl) phosphonium tetrakis (pentafluorophenyl) borate; di-substituted ozone salts such as diphenylozonium tetrakis (pentafluorophenyl) borate, di (o-tolyl) ozone tetrakis (pentafluorophenyl) borate, and di (2,6-dimethylphenyl) ozonium tetrakis (pentafluorophenyl) borate; di-substituted sulfonium salts such as diphenylsulfonium tetrakis (pentafluorophenyl) borate, tetrakis (pentafluorophenyl) borate di (o-tolyl) sulfonium, and bis (2,6-dimethylphenyl) sulfonium tetrakis (pentafluorophenyl) borate. Preferred (L "-H) + cations are N, N-dimethylanilinium and tributylammonium Another suitable ion-forming activation cocatalyst comprises a salt of a cationic oxidation agent and a non-coordinating compatible anion, presented by the formula : (Oxe +) d (Ad-) 0 where: Oxe + is a cationic oxidation agent that has a charge of e +; e is an integer from 1 to 3; and Ad 'and d are as previously defined. Examples of cationic oxidation agents include: ferrocenium, hydrocarbyl substituted ferrocenium, Ag "or Pb-2 Preferred embodiments of Ad-s are those previously defined anions with respect to Bronsted acid containing activating cocatalysts, especially tetrakis (pentaf). luorofenil) borate.

Another suitable ion formation activating cocatalyst comprises a compound which is a carbenium ion salt and a compatible non-coordinating anion represented by the formula; © "A" where: © is a carbenium ion of C1.20, and A 'is as previously described .. A preferred carbenium ion is the trityl cation, ie, triphenylmethylium. Suitable ion formation comprises a compound which is a salt of a non-coordinating compatible silyl ion and anion represented by the formula: R '"3SGA ~ where: R'" is Ct-io hydrocarbyl, and A "is as define previously. Silyl salt activating cocatalysts are trimethylsilyl tetrakispentafluorophenylborate, triethylsilyl tetrakispentafluorophenylborate and ether-substituted adducts thereof. Silyl salts have previously been generically described in J. Chem Soc. Chem. Comm. , 1993, 383-384, as well as Lambert, J. B., and others Orqanometallics, 1994, 13, 2430-2443. The use of the above silyl salts as activating cocatalysts by addition to the polymerization catalysts is described in US-A-5,625,087. Certain complexes of alcohols, mercaptans, silanols, and oximes with tris (pentafluorophenyl) borane are also activators of effective catalysts and can be used in accordance with the present invention. Such cocatalysts are described in the EUA-A ,296,433. The volume electrolysis technique involves the electrochemical oxidation of the metal complex under electrolysis conditions in the presence of a supporting electrolyte comprising an inert non-coordination anion. In the art, solvents, support electrolytes and electrolytic potentials for electrolysis are used in such a way that electrolysis by products that can render the catalyst complex catalytically inactive are not substantially formed during the reaction. More particularly, suitable solvents are materials that are (i) liquid under conditions of electrolysis (generally temperatures from 0 to 100 ° C), (ii) capable of dissolving the supporting electrolyte, and (iii) inerts. "Inert solvents" are those that are not reduced or oxidized under the reaction conditions used for electrolysis. It is generally possible in view of the desired electrolysis reaction to choose a solvent and a supporting electrolyte that are not affected by the electrical potential used for the desired electrolysis. Preferred solvents include difluorobenzene (all isomers), dimethoxyethylene (DME), and mixtures thereof.

The electrolysis can be conducted in a normal electrolytic cell containing an anode and cathode (also referred to as the working electrode and electrode respectively). Suitable materials for cell construction are glass, plastic, ceramic and metal covered with glass. The electrodes are prepared from inert conductive materials, by which is meant conducting materials that are not affected by the reaction mixture or reaction conditions. Platinum or palladium are preferred inert conductive materials. Normally an ion permeable membrane such as a fine glass sand separates the cell into separate compartments, the working electrode compartment and counter electrode compartments. The working electrode is immersed in a reaction medium comprising the metal complex to be activated, the solvent, the supporting electrolyte and any other material desired to moderate the electrolysis or stabilize the resulting complex. The counter electrode is immersed in a mixture of solvents and supporting electrolyte. The desired voltage can be determined by theoretical or experimental calculations by sweeping the cell using a reference electrode such as a silver electrode immersed in the cell electrolyte. The background cell current is also determined, the current extraction in the absence of the desired electrolysis. The electrolysis is completed when the current falls from the desired level to the previous level. In this way, the complete conversion of the initial metal complex can be easily detected.

Suitable supporting electrolytes are salts comprising a cation and a non-coordinating compatible anion, A '. The preferred support electrolytes are salts corresponding to the formula G * A 'wherein G * is a cation which is not reactive towards the starting and the resulting complex, and A' is as previously defined. Examples of cations, G *, include ammonium or phosphonium cations substituted with tetrahydrocarbyl having up to 40 non-hydrogen atoms. Preferred cations are tetra (n-butyl) ammonium and tetra (ethyl) ammonium cations. During the activation of the complexes of the present invention by volume electrolysis, the cation of the supporting electrolyte passes to the counter electrode and A 'migrates to the working electrode to become the anion of the resulting oxidized product. Both the solvent or the cation of the supporting electrolyte is reduced in the counter electrode in equal molar amount with the amount of oxidized metal complex formed in the working electrode. The preferred support electrolytes are tetrahydrocarbylammonium salts of. { borates of tetrakis (perfluoroaryl) having from 1 to 10 carbons in each hydrocarbyl or perfluoroaryl group, especially tetrakis (pentafluorophenyl) borate of tetra (n-butylammonium). An additional recently discovered electrochemical technique for the generation of activating cocatalysts is the electrolysis of a disilane compound in the presence of a source of a compatible non-coordinating anion. All of the above techniques are described more fully and are claimed in published international patent application WO 95/00683. Inasmuch as the activation technique ultimately produces a cationic metal complex, the amount of such resulting complex formed during the process can be easily determined by measuring the amount of energy used to form the activated complex in the process. Alumoxanes, especially methylalumoxane or modified triisobutylaluminium methylalumoxane are also suitable activators and can be used to activate the metal complexes. A preferred activating cocatalyst is trispentafluorophenylborane. The molar ratio of the metal complex: activation cocatalyst employed preferably ranges from 1: 1000 to 2: 1, more preferably from 1: 5 to 1.5: 1, more preferably from 1: 2 to 1: 1. In general, the polymerization can be completed under conditions well known in the prior art for polymerization reactions of the Ziegler-Natta or Kaminsky Sinn type, that is, temperatures from 0 to 250 ° C and pressures from atmospheric to 1000 atmospheres (MPa). The suspension, solution, slurry, gas phase or other polymerization process conditions may be employed if desired, however, the solution polymerization process conditions, especially continuous solution polymerization process conditions, are preferred. A support may be employed but preferably the catalysts are used in a homogeneous form, ie, dissolved in the solvent. Of course, the active catalyst system can form in situ if the catalyst and its cocatalyst components are added directly to the polymerization process and a suitable solvent or diluent (e.g., hexane, iso-octane, etc.) including Condensed monomer, are also used. Preferably the active catalyst is formed separately in a suitable solvent, e.g. , in a strip current, before adding this to the polymerization mixture. As mentioned previously, the above catalyst system is particularly useful in the preparation of elastomeric polymers in performance and high productivity. The process employed can be a solution or slurry process both of which are previously known in the art. Kaminskv, J. Polv. Sci., Vol. 23, pp. 2151-64 (1985) reports the use of a bis (cyclopentadienyl) zirconium dimethyl-alumoxane catalyst system for the polymerization of EPDM elastomer solution. USA-A-5, 229,478 discloses a slurry polymerization process using catalyst systems based on bis (cyclopentadienyl) zirconium-like catalyst. In general, it is desirable to produce elastomers for use in the present invention under conditions of increased reactivity of the diene monomer component. Advantageously, a single-site catalyst, v. gr. , a monocyclopentadienyl or indenyl metallocene, which is chosen to allow for increased diene reactivity which results in the preparation of ethylene / α-olefin / diene polymers in high yield. For example, the monocylopentadienyl and indenyl metallocene catalysts, previously described, perform well in this respect. Additionally, these catalyst systems carry out the fast curing economical production of ethylene / α-olefin / diene polymers with diene content of up to 20 weight percent. The preferred ethylene / α-olefin / diene polymer products are made with a catalyst that is free of aluminum (the presence of which has a deleterious effect on certain of the physical properties of the product, eg, color). In addition, due to the high efficiency of these aluminum-free catalysts, less is required and since less is required, less catalyst residue is present in the final product. In fact very small catalyst residue is present in the final product that the process of these embodiments does not require a removal or treatment step of catalyst waste as required in conventional processes. The ethylene / α-olefin / diene polymer products made using such catalysts are also substantially free of color bodies. Another aspect of the present invention is a process for making the polymer blend of the invention in the form of an article. The manufactured articles can be made of ethylene / α-olefin / modified diene polymer according to this invention using any conventional EPDM processing technique.

The process may include a rolling and co-extrusion technique or combinations thereof, or using only the polymer mixture, and includes a blowing film, vacuum film, extrusion coating, injection molding, blow molding, compression molding, Rotomolded, or injection blow molding operation or combinations thereof, calendering, sheet extrusion, profile extrusion for making a film, a molded article or an article comprising a layer of ethylene / α-olefin polymer film / diene or coating and extrusion, injection molding, of the elastomer modified with a blowing agent to make an article comprising foam rubber. The novel polymers described herein are particularly useful for wire and cable coating operations, as well as in sheet extrusion for vacuum forming operations. The modification of the selected polymer according to this invention involves partially entangling the selected ethylene / α-olefin / diene polymer to make an ethylene / α-olefin / modified diene polymer that satisfies the following equations: MV < 100 fMS * -MS. \ W = V, MS,) where MSi, MS2, and W are measured as defined above. The Mooney viscosity for the elastomers after modification according to this invention preferably ranges from a minimum of about 10, more preferably at least about 15, even more preferably at least about 20 and still more preferably about 30, above a maximum viscosity of about 100, more preferably above about 80 and even more preferably above about 70. Preferably, MSi, is preferably not greater than 20, MS2 is preferably at least 80, and W it is preferably about 0.5, more preferably about 0.7, more preferably about 0.8, still more preferably about 5.0, still more preferably about 7.0, and even more preferably about 8.0. The gel% of the modified polymer is preferably less than or equal to 60 percent, more preferably less than 30 percent, more preferably less than 20 percent, even more preferably less than 10 percent and even more preferably less than 5 percent . The modified polymer preferably has a gel percent that is preferably no more than about 20 percent greater, more preferably no more than about 10 percent greater, than the gel percent of the unmodified polymer selected in step ( TO) . The rheology of the above polymers is preferably modified to satisfy the equation: MV "geC". * &in which X is 50, preferably 45, Y is 20, more preferably 10 and even more preferably 5, and Z is 40, more preferably 50, and even more preferably 55, and MS2, MV and% by Gel, which includes its preferred scales, are as defined above. Interlacing agents include peroxide compounds and other known heat-activated curing agents, such as azo compounds, and electron beam, gamma rays and other known radiation curing systems. If the entanglement agent is a heat activated substance, v. gr. , a peroxide, then this agent is processed by melting with the ethylene / α-olefin / diene polymer to modify it according to this invention. The various entanglement agents may be used alone or in combination with some other. The excess or residual peroxide may be available to initiate the entanglement along with another entanglement agent, electron beam, etc. , to further entangle the ethylene polymer after the production of an interlacing molded article having more than 30% by weight, preferably at least 60% by weight, even more preferably at least 70% by weight, gel up to 100 % gel Heat activated entanglement agents include free radical initiators, preferably organic peroxides, more preferably those with half-hour lives at temperatures greater than 120 ° C. The free radical initiators may be selected from a variety of known free radical initiators such as peroxides (e.g., di-t-butyl peroxide (available from Elf Atochem), VU LCU P ™ (a series of vulcanization agents and polymerization containing a, a'-bis (t-butylperoxy) -diisopropylbenzene made by Hercules, I nc.), DI-CU P ™ (a series of vulcanization and polymerization agents containing dicumyl peroxide made by Hercules, I nc.), LU PERSOL ™ 101 (2, 5-dimethyl-2, 5-di (t-butylperoxy) hexene), LUPERSOL ™ 130 (2,5-dimethyl-2, 5-di (t-butylperoxy) hexino- 3), LU PERSOL ™ 575 (t-amyl peroxy-2-ethylhexonate) all LU PERSOL ™ peroxides are commercially available from Elf Atochem, North America) or TRIGONOX ™ (an organic peroxide produced by Noury chemical Company)) or treatment of radiation (?, ß or a, which includes irradiation electron beams). In one embodiment, a heat activated compound, such as peroxide-containing compound, can be used as the crosslinking agent. The polymer is treated with a heat activated entanglement agent in the amount required to cause modification of the melting strength of the polymer in accordance with the conditions specified above. When the entanglement agent is a peroxide compound, the amount of peroxide compound is preferably on the scale from a minimum of at least about 0.01 mmol, preferably at least about 0.04 mmol, up to a maximum of less than 0.8 mmoles, preferably above about 0.2 mmoles, of ethylene / α-olefin polymer / radical diene / kg of peroxide. The concentration of entanglement agent required to modify a particular polymer depends on the susceptibility of the interlacing polymer and is influenced by factors such as its percentage of vinyl unsaturation and the amount of chain branching especially short chain branching. The formulations are compounded by any convenient method, which includes dry blending of the individual components and subsequently mixing by melting or melt processing, by spraying the heat activated entanglement agent onto solid polymer pellets and subsequently mixing by melting or processing by melting or by pre-melting in a separate device (e.g., a Banbury mixer, a Haake mixer, an internal Brabender mixer, or a single screw or twin screw extruder). Compounding with a twin screw extruder, such as model ZSK-53 produced by Werner and Pfleiderer, is preferred, but other extruder configurations may be used such as those described in EUA-A-5,346,963. When the entanglement agent is radiation, the absorbed dose of radiation is preferably in the gray scale of about 1 to about 20 (Joules of energy absorbed radiation / kg of ethylene polymer / α-olefin / diene). Similar to the case with heat activated entanglement agents, the dosage required to modify a particular polymer depends on the polymer's susceptibility to interlacing and is generally influenced by the same factors. The radiation is preferably applied on a wavelength scale from about 0.01 to about 1 x 10"5 nanometers (nm) .The irradiation conditions are preferably adjusted to avoid unwanted side effects. example, preferably adjusted to avoid substantial heating of the polymer, because it can cause the polymer to react with oxygen in the air and with oxygen dissolved in the polymer, which in turn could cause degradation of the polymer, resulting in Long term stability reduction and / or increased potential to form gels, unless additional measures are taken to prevent contact with oxygen. Excessive heating would also risk the particles or pellets together of the discrete melting polymer, making it inconvenient for use with conventional fusion processing equipment. These side effects can be avoided by adjusting the radiation dose ratio and / or driving the process in an inert atmosphere. Adjusting the radiation dose ratio is, from a practical fixed point, preferable. The radiation dose rate is preferably less than 20 Mrad / s, more preferably less than 10 Mrad / s, and even more preferably less than 7 Mrads / s. The treatment of the entanglement agent can be carried out online. The treatment of the in-line entanglement agent is carried out on the polymer as the polymer is produced, preferably immediately after the polymerization and devolatilization before the first solidification of the polymer (usually by means of pelletization). When the entanglement agent is a heat activated compound, the compound can be added as a solvent or as a concentrate in a masterbatch. The modification according to this invention can also be carried out offline. Off-line modification can be carried out by treating an unmodified polymer with crosslinking agent after it has been solidified (usually as pellets or granules). When the entanglement agent is radiation energy, the polymer can be treated by exposing the polymer, preferably as a solid, to the radiation energy under conditions that allow control of the amount of energy absorbed by the polymer. When the entanglement agent is a heat activated compound as described above, it is combined with, or coated on, the pellets of the polymer or granules and subsequently the pellets or polymer pellets are melt processed or added to the polymer, directly or preferably in the form of a concentrate or masterbatch, during the fusion process such as through one of the ports for adding components to the fusion frequently provided in the processing equipment.

A rhodium-modified polymer according to this invention can be combined with one or more additional polymers to form polymer blends. The additional polymers can be modified or not modified by rheology. They may be selected from any of the modified polymers and from the unmodified polymers described above which serve as starting materials for the modification in accordance with this invention. The additional polymers may also be heterogeneously branched polymers, such as, low density polyethylene. (LDPE), linear low density polyethylene (LLDPE) polymers, substantially linear ethylene polymers (LLDPE), and / or high density ethylene polymers (HDPE). Any of the additional polymers mentioned above may be grafted or copolymerized with various functional groups. The polymer blends of the present invention can be prepared by physically mixing these polymers in an appropriate mixer and / or extruder, combining the flow of two or more reactors used to make these polymers connected in series or in parallel, and / or by mixed in reactors using two or more catalysts in a single reactor or combinations of multiple catalysts or multiple reactors. The general principle of making polymer blends by mixing in a reactor using two or more catalysts in a single reactor or combinations of multiple catalysts and multiple reactors is described in WO 93/13143; WO 94/01052; EP-A-619827; and US-A-3, 914, 342. Polymer blends can be prepared by selecting an appropriate catalyst and process conditions with a view to the characteristics of the final composition and performing the on-line rheology modification step as the polymers they are mixed, or out of line after said mixing step. The present invention also encompasses intermediates for making modified polymers in accordance with this invention, which can be melt processed in the finished article alone or in combination with the other polymers described above. Such intermediates can also be pellets or granules comprising the selected polymer that has been sprayed, coated in some other form, or combined with an unreacted heat activated entanglement agent, such as a peroxide compound or an azo compound. The heat-activated compound can be applied neat or with an adjuvant or with a substance that retards the reactivity of the heat-activated compound at temperatures below the intended melt processing temperature. The pellets or granules treated with the heat-activated compound can be further treated to seal the heat-activated compound on the surface of the pellets or pellets, if necessary. The modification according to this invention can be carried out using polymers containing little or no secondary antioxidant. This may be preferred in cases where the polymer will undergo additional processing in which the manufacturer conditions the polymer with its own additive package that includes one or more antioxidants. This, in some cases, may also be preferred from a cost and color point of view of the polymer, since some antioxidants may react with the crosslinking agent, using up to some of the antioxidants intended to protect the polymer against oxidation and possible formation of colored by-products. This invention also encompasses the products made by all the above processes. This invention is further described by the following examples.

These examples are provided for illustration only and should not be construed as limiting the scope of the invention described more fully herein. Examples Description of the process Rheology modification Examples 1-4 have modified viscosity in a Haake Rheocord 40 torque rheometer drive unit and Rheomix 3000E mixer (available from Haake Buchier Instruments) equipped with roller style spatulas. Examples 5, 6 and 7 have modified viscosity on a torque rheometer drive unit of Haake Rheocord 40 coupled with a Rheomix 202 single screw extruder of 1.9 cm.

Examples 8, 9 and 10 have a modified viscosity in a Killion single-screw extruder of 3.8 cm in diameter. Base resins TABLE I Characteristics of base resins The additive package for the EPDM base resins 5, 6 and 7 is 1250 ppm of calcium stearate, 1000 ppm of Irganox 1076 and about 1600 ppm of Sandostab PEPQ.

Entanglement Agents The peroxide used for Examples 1-4 and 6-7 is 2,5-dimethyl-2,4-di (t-butyl-eroxy) -3-hexyne (commercially available as Lupersol ™ 13Q) The peroxide used for the Examples 5 and 8-10 is 2,5-dimethyl-2,4-di (t-butyl peroxy) -3-hexane (commercially available as Lupersol ™ 101) Formulation Ingredients Table 2 Key for Formulation Ingredients Method for Preparing Samples Modification of rheology Examples 1-4 are prepared by loading the fixed elastomer into the mixer at 160 degrees C and 30 rpm mixing speed. The loading force is lowered to force mixing into the mixer and the force is kept low during run (except during peroxide addition) to reduce exposure to air. After the elastomer is charged, the force is raised and the liquid peroxide is slowly added using a syringe to direct the peroxide over the flow polymer sample (avoiding the metal surfaces which can cause volatilization of the peroxide). The weight of the peroxide is calculated from the weight loss of the syringe. After about 3 minutes, the temperature is increased to 190 ° C to decompose the peroxide. The operation continues until the torque reaches a leveling for 2-5 minutes, which indicates that the rheology modification reaction was completed. The total mixing time is approximately 15-20 minutes. The sample is removed from the mixer and cooled, and then granulated using a low speed Colortronic granulator. Examples 5-7 are prepared by inhibiting the elastomer with peroxide solution, which is extruded at low temperature to ensure homogenization / mixing and then extruded at high temperature to carry out the rheology modification reaction. Therefore, the described samples are produced by placing 227 grams of EPDM in a 3.8 liter H DPE jar which contains 1 .3 cm of stainless steel ball bearings to prevent the polymer from forming lumps, adding peroxide along with -20 grams of methyl ethyl ketone, and then mixing with rollers for 16 hours. The pellets are then dried under conditions to remove the methyl ethyl ketone but do not devolatize the peroxide. The subsequently imbibed pellets are extruded at 1 10 ° C, granulated, and then extruded again at 200 ° C. Examples 8-9 are prepared by soaking the elastomer with peroxide solution, extruding at low temperature to ensure mixing and then extruding at high temperature to perform the rheology modification reaction. The embedding process involves placing the pellets inside a 68 kg H DPE drum. The stainless steel ball bearings are added to prevent the polymer from forming lumps. Subsequently, the peroxide is diluted with methyl ethyl ketone (CME) and that solution is rapidly added onto the pellets (the amount of CME is usually 3-5 weight percent). Subsequently, the lid is closed and the drum is rotated end to end for 4 to 16 hours. Pellets, ball bearings and embedded pellets are then spread on an HDPE film for the CME to evaporate. The first extrusion step ("homogenization") is completed by extruding at 126 ° C while the extruder is operating at 25-45 rpm. The second step ("reaction") is completed at 210 ° C at an extruder speed of 25 rpm.

Example 10 is prepared by imbibing the elastomer with peroxide solution, extruding at low temperature to ensure mixing and then extruding at high temperature to perform the rheology modification reaction according to the same procedure as used for examples 8 and 9, except that when the pellets, ball bearings and embedded pellets are spread on an HDPE film so that the CME evaporates, this material is re-milled and then dried by air cooled by blowing through the pellets on the HDPE film to reduce the formation of lumps. The product is also cooled before the second extrusion step to eliminate lumping. Formulation The elastomer formulations for examples 1, 2 and 3 are prepared with a Haake Rheomix 3000 mixer as described above and then milled with rollers for the melt strength test as described below. Formulations Examples 1-3 were formulated in accordance with ASTM D-3568 # 2 as follows: 35.21 weight percent resin 0.35 weight percent stearic acid 1.76 weight percent Kadox 72 zinc oxide. 35.21% by weight of carbon smoke N330 26.41 weight percent Circosol 4240 0.18 weight percent .Captax (MTB) 0.35 weight percent Methyl Tuads (TMTD) 0.53 weight percent Sulfide Examples 8- 1 0 is formed according to ASTM 3865 as follows: 41.84 weight percent resin 0.42 weight percent stearic acid 2.09 weight percent Kadox 72 zinc oxide. 33.47 weight percent smoke 20.92 percent by weight of Circosol 8240 0.21 percent by weight of Captax (MTB) 0.42 percent by weight of Methyl Tuads (TMTD) 0.63 percent by weight of Su lfu ro Product Analysis melt index According to ASTM a 1 90 degrees C and using 2. 16 kg or 10 kg of weight. Moonev The data were obtained in a Monsanto MV2000E viscometer at 125 degrees C using the large rotor size and reading the viscosity at 5 min utes (M L 1 +4). Resistance to fusion The resistance to fusion was measured with a Goettfert Rheotens.

The Rheotens measures the melting strength as well as the speed / tension force. The melting strength is taken as the leveling of the force velocity curve. When approximately 10 grams of formulated material is tested, it is placed in the capillary rheometer at the correct temperature. The extrusion of the rheometer is positioned between two wheels of rotation of the Rheotens which is situated very close so that the extrudate is drawn through the wheels. The wheels are accelerated to 2.4 m / s2, and the force is measured as the function of the speed of the wheels. Eventually, the extrudate breaks and the test is finished. The test conditions are given of 2.1 mm in diameter, 42 mm in length, aspect ratio of 20.0, crossover speed of 25.4 mm / min, shear rate of 33 reciprocal seconds, air gap between the rheometer output and The Rheotens is 100 mm and the initial wheel speed is 10 mm / sec. All tests are carried out at 110 C to avoid vulcanization of the formulation. Gel Percentage The amount of gel was determined by pressing small samples (2-3 grams) on films of approximately 5.08 x 10"3 cm and then xylene extraction was performed according to ASTM conditions with the exception that instead of grinding the polymer to a powder as it is done with polyethylene, thin films are used directly (the Wiley mill creates too much heat).

Example 1 Results with Base Resin 1 Example 2 Results with Base Resin 2 Example 3 Results with Base Resin 3 Example 4 Results of Base Resin 4 Example 5 Results with Base 6 Resin, operation # 1 Example 6 Results with Base 6 Resin, operation # 2 Example 7 Results with Base Resin 5 Example 8 Results with Base Resin 7 Example 9 Base Resin Results 8 Example 10 Results with Base Resin 9 As can be seen from the above examples, this invention can be applied to improve the strength before treatment of a wide scale of ethylene / α-olefin / diene polymers selected in accordance with this invention while maintaining a good processability. The melt strength data for Examples 1-3, especially Examples 1 and 2, show in particular that the melt strength can be substantially improved according to this invention without a substantial increase in viscosity or substantial gel formation. Although the invention has been described in considerable detail through the foregoing specific embodiments, it should be understood that these embodiments are for the purposes of illustration only. Many variations and modifications can be made by one skilled in the art without departing from the spirit and scope of the invention.

Claims (20)

1. CLAIMS 1. A process for improving the strength before the treatment of the ethylene / α-olefin / diene polymers comprising: (A) selecting an ethylene / α-olefin / diene polymer having a Mooney viscosity ML1 + 4, measured in accordance with ASTM D 1646 at 125 C, up to 80 and a percentage of gel, measured in accordance with ASTM D 2765, Procedure A, up to 30 percent and (B) partially entangling the ethylene / α-olefin / diene polymer selected in step (A) to produce an ethylene / α-olefin / diene polymer that satisfies the following equations: MV < 100 ÍMS.-MS.? W = MS,) wherein MV is the Mooney viscosity of the modified polymer as defined in step (A), MS-. is the melt strength in centiNewtons of the polymer selected in step (A) when formulated in accordance with ASTM D3568 # 2, MS2 is the melt strength in centiNewtons of the modified polymer also when formulated in accordance with ASTM D3568 # 2, and W is 0.3.
2. 2. The process of claim 1, wherein the modified polymer further complies with the equation: MS, = (MV% ge - where MS2, MV and% gel are the melting strength, the Mooney viscosity and gel percentage of the modified polymer measured as previously defined and the variables X, Y, and Z are 50, 20 and 40, respectively 3.
3. The process of claim 1 or 2, wherein W is 5.0 4.
4. The process of any of claims 1 or 3, wherein MS2> _80 5.
5. The process of any of the claims 1 to 4, wherein the modified polymer has a gel percentage no more than 10 percent greater than the gel percentage of the polymer selected in step (A).
6. The process of any of claims 1 to 5, wherein the α-olefin is propylene and the diene is 5-ethylidene-2-norbornene.
7. The process of any of claims 1 to 6, wherein the polymer selected in step (A) has a melt index ratio (10/12 to 190 ° C) of less than about 10.
8. 8. The The process of any of claims 1 to 7, wherein the partial entanglement is carried out by contacting the polymer by selecting in step (A) with the peroxide crosslinking agent under melt processing conditions.
9. The process of any of claims 1 to 7, wherein the partial entanglement is carried out by exposing the polymer selected in step (A) to the radiation having a wavelength less than 0.01 nanometers at an intensity sufficient to generate free radicals in the selected polymer.
10. 10. An intermediate for producing an ethylene / α-olefin / diene polymer according to the process of claim 8, comprising a polymer selected in accordance with step (A) in combination with unreacted peroxide crosslinking agent in an amount suitable for modifying the selected polymer according to the process of claim 8 under melt processing conditions.
11. 11. A modified polymer obtainable according to the process of any of claims 1 to 9.
12. 12. An ethylene / α-olefin / modified diene polymer which meets the equation: where MS2 is the melt strength in centiNewtons of the modified polymer when formulated in accordance with ASTM D3568 # 2, MV is the viscosity ML 1 + 4 of the modified polymer measured in accordance with ASTM D 1646 at 125 C,% gel is the percent of modified polymer gel measured in accordance with ASTM D2765, Procedure A, and variables X, Y, and Z are 50, 20 and 40 respectively.
13. 13. A process for manufacturing an article comprising an ethylene / α-olefin / diene polymer comprising: (A1) melt processing the intermediate of claim 10; (B1) forming the product of step (A1) in one form; and (C1) curing the product of step (B1) to form an article comprising an interlaced ethylene / α-olefin / diene polymer.
14. 14. The process of claim 13, wherein step (B1) is carried out by means of injection molding.
15. 15. The process of claim 13, wherein step (B1) is carried out by extrusion.
16. 16. The process of claim 15, wherein the article is wire or cable coated with the interlaced ethylene / α-olefin / diene polymer of step (C1).
17. 17. A process for manufacturing an article comprising an ethylene / α-olefin / diene polymer comprising: (A1) melt processing the modified polymer of claim 11 or 12; (B1) forming the product of step (A1) in one form; and (C1) curing the product of step (B1) to form an article comprising an interlaced ethylene / α-olefin / diene polymer.
18. 18. The process of claim 17, wherein step (B1) is carried out by injection molding.
19. The process of claim 17, wherein step (B1) is carried out by extrusion.
20. 20. The process of claim 19, wherein the article is wire or cable coated with the interlaced ethylene / α-olefin / diene polymer of step (C1).