MXPA99008180A - Elastomer compositions having improved abrasion resistance, coefficient of friction and hot green strength - Google Patents

Abstract

An elastomeric composition that provides excellent abrasion resistance and is useful for producing fabricated articles includes a plasticizer and a crystalline polyolefin phase that is either continuous or co-continuous with an ethylene/&agr;-olefin polymer phase. Certain compositions also contain a material that enhances Wet COF of the composition, and in some instances, processibility of the compositions. Other compositions obtain the same enhancement by choice of process conditions. The resulting articles also have an enhanced Wet COF.

Description

ELASTOMERIC COMPOSITIONS THAT HAVE RESISTANCE TO ABRASION, COEFFICIENT OF FRICTION AND THERMAL RESISTANCE BEFORE THE IMPROVED TREATMENT FIELD OF THE INVENTION This invention relates generally to elastomeric compositions comprising an elastomeric ethylene / alpha (α) -olefin polymer (EAO) and a crystalline polyolefin (CPO), the preparation of the composition, the use of the composition in processes such as extrusion of profiles and mold by injection and articles of manufacture, such as external soles for footwear, resulting from such processes. This invention relates in particular to those compositions where the CPO forms a phase which is at least co-continuous with a phase formed from the EAO polymer, the methods for preparing the compositions, the use of the resulting compositions and articles of manufacture. This invention also relates to those compositions modified by a material (COFE) that improves the coefficient of friction (COF). A COFE material, when added, provides an increase in COF on wet tiles with a thickness greater than 18 millimeters (hereinafter "wet COF"), as measured by ASTM D-1894, on REF .: 30931 obtained with the composition in the absence of the COFE material. This invention is further related to certain compositions containing COFE having improved processability in relation to compositions lacking the COFE material. This invention relates even more to the process variations that produce an elastomeric composition with an improved COF in the absence of a COFE material.

BACKGROUND OF THE INVENTION. K. Fischer provides a variety of teachings related to mixtures of an EAO polymer with a polyolefin. For example, USP 3,758,643 and USP 3,806,558 contain teachings about partially cured mixtures of an EAO copolymer with a polyolefin. USP 3,835,201 describes uncured mixtures of an interpolymer with properties similar to those of the unsaturated rubber of at least two different α-mono-olefins with a small amount of a copolymerizable, non-conjugated diene and high poly-α-mono-olefinic plastic. resinous molecular weight (MW), such as PP. The interpolymer with properties similar to those of rubber, must have a cutting viscosity at a cutting speed of zero or a high viscosity in the molten state at a cutting speed of zero. These interpolymers are considered non-processable, because they do not form a band on a cold laminator. USP 3,862,106 relates to a dynamically cured thermoplastic blend of an EAO copolymer with a polyolefin. Both partial curing and dynamic curing lead to an increase in the insoluble gel content. The insoluble gel content test (gel value) uses cyclohexane at 23 ° C. An acceptable substitute is boiling xylene, a common solvent that produces a gel value 30-50% lower than that found using cyclohexane. Fischer provides several examples in which gel particles are present at a sufficiently high level to produce an unacceptable rugosity when the partially cured or dynamically cured compositions are extruded as an eight inch (20.32 centimeter) high rod. Mike Wilson, in "Slip Resistance Performance of Soling Materials", SATRA Bulletin, May 1996, pages 77-79, a publication produced by SATRA Foot ear Technology Center, suggests, on page 78, that a minimum coefficient of friction (COF) ) for soles of footwear and heels in dry tiles with a thickness greater than 18 millimeters and in wet ones it is 0.3. He also suggests, on page 79, that applications in sports and industrial footwear may be more demanding in terms of slip resistance and require a COF of at least 0.4, sometimes at least 0.6. US-A-4, 239, 862 discloses thermoplastic elastomers comprising a mixture of an ethylene / alpha-olefin copolymer rubber, a crystalline polyolefin resin and. a long-chain aliphatic alcohol having at least 16 carbon atoms. The alpha-olefin contains from 1 to 12 carbon atoms. The rubber may include a diene thermonomer. The mixture may include a non-elastomeric amorphous propylene polymer and a naphthenic and paraffinic extender oil. US-A-4-036, 912"discloses thermoplastic polymer blends of specific ethylene / propylene copolymers or ethylene / propylene / diene terpolymers (EPDM) with a crystalline polypropylene polymer GB-A-1, 180, 281 describes compounds of an ethylene / propylene copolymer with rubber-like properties, or terpolymer of EPDM with a hexane-soluble polypropylene or propylene / alpha-olefin-block polymer soluble in hexane, US-A-3,851, 11 describes footwear having a contour incorporated in the portion of the heel of the paddle.

The contour is a thermoplastic article made of a mixture of a monoolefin copolymer rubber and a polyolefin plastic. The contour adds rigidity to the heel and provides a frictional engagement with the user's heel to help keep the shoe in place on the wearer's foot. The rubber can be a terpolymer such as an ethylene / propylene / diene monomer rubber. La, EP-A-0, 779, 333 describes an elastomeric, thermoplastic composition, spread with non-flammable, non-crosslinked oil. The composition comprises an ethylene / alpha-olefin copolymer with properties similar to those of rubber, a polypropylene resin, low density polyethylene, mineral oil and an ammonium polyphosphate coated with melamine. The composition can be used to manufacture skins for automotive interior finishes.

BRIEF DESCRIPTION OF THE INVENTION One aspect of this invention is an elastomeric composition comprising: a. from 20 to 50 parts by weight (pbw), based on the combined weight of a and b, of a CPO selected from the group consisting of polypropylene homopolymers (PP) and propylene / ethylene copolymers (P / E); b. from 80 to 50 pbw, based on the combined weight of a and b, of an elastomeric EAO polymer, the polymer optionally has polymerized in the a diene monomer; c. from 1 to 200 pbw, per 100 pbw of EAO polymer of a plasticizer, the plasticizer is selected from the group consisting of hydrocarbon oils and alkyl esters of a carboxylic acid; and optionally, d. from 0 to 40 pbw, per 100 pbw of a and b, of a material that provides an increase in the wet COF over the coefficient of wet friction of a composition that includes only a, b and c. The elastomeric composition preferably has the CPO and the EAO polymer present as two distinct phases. Preferably, the phase of the CPO is at least co-continuous with the phase of the EAO polymer. The composition desirably has an abrasion resistance (ASTM D 1630-83, an NBS Abrasive) that is greater than (>) that of a similar composition prepared from the same components, but with a single phase continuous formed of the EAO polymer. All the intervals specified in this application include both endpoints unless otherwise specified. A second aspect of this invention is a process for preparing the elastomeric composition of the first aspect, the process comprising subjecting a combination of: a. 20-50 pbw, based on the combined weight of a and b, of a CPO selected from the group consisting of polypropylene homopolymers and propylene / ethylene copolymers; b. 80-50 pbw, based on the combined weight of a and b, of an elastomeric EAO polymer, the EAO polymer optionally has polymerized therein a diene monomer; c. 1-200 pbw, per 100 pbw of elastomeric EAO polymer, of a plasticizer, the plasticizer being selected from the group consisting of hydrocarbon oils and alkyl esters of a carboxylic acid; and, optionally, d. from 0-40 pbw, per 100 pbw of a and b, of a material that provides an increase in the COF in Humid on the coefficient of friction of a composition that includes only a, b and c, at conditions of temperature, cut and pressure sufficient to form a two-phase mixture composition, wherein the crystalline polyolefin is at least one co-continuous phase with the polymer phase of the EAO. The second aspect has two related aspects of interest. In one, the combination includes the COFE material in an amount sufficient to improve the COF in Wet of the resulting two-phase mixed composition relative to the COF in Wet of a similar combination except in the absence of COFE material. In another, a and b undergo conditions of temperature, cut and pressure sufficient to form a first mixed, molten composition, after which the first mixed, molten composition and c are subjected to conditions of temperature, cut and pressure sufficient to form the composition mixed of two phases, the two-phase composition has a wet COF >; that of a two-phase composition formed by subjecting a combination of a, b and c to a single iteration of the temperature, cut and pressure conditions. The conditions used to form the first mixed, melted composition, and the conditions used to form the two-phase composition of the first molten, mixed composition, are preferably the same. A third aspect of this invention is an article of manufacture having at least one component thereof made from the composition of the first aspect of the invention. The compounds suitably include at least one filler or filler. The following paragraph, the "Brief Description of the Drawings" contains a partial list of suitable articles of manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an Electronic Micrograph of Transmission (TEM), taken at a magnification of 7,500 X, of the composition of Comparative Example (Ex Comp) B showing that the PP, the light colored material, is a discontinuous phase and that the ethylene / propylene / diene monomer (EPDM), the dark colored material, is a continuous phase. The scale of the bottom of the micrograph represents a micrometer. Figure 2 is a TEM, taken at the magnification of 7,500 X, of the composition of Example (Ex) 4 which shows that the light and dark colored materials, respectively PP and EPDM, are present at least as co-continuous gases.

DESCRIPTION OF THE PREFERRED MODALITIES The compositions of this invention can be formed into a variety of articles formed using conventional polymer manufacturing processes such as those identified. previously. The compositions are particularly suitable for use in the manufacture of injection molded rubber components, such as exterior or unitary footwear soles, and products in the form of extruded sheets and profiles, such as gaskets and weatherproofing devices. A partial list, of a more exhaustive one, of suitable shaped articles includes automotive body parts such as front bumpers, body side moldings, exterior finishes, interior finishes, air ducts, air ducts, wheel covers and linings for the car body. instruments, and non-automotive applications such as polymeric films, polymer sheets, trash cans, storage containers, strips or treads for lawn mowers, lawn mowers and other parts of garden appliances, recreational vehicle parts, golf cart parts , parts of utility cars and parts of watercraft. The compositions can also be used in roofing applications such as roofing membranes. The compositions may also be used to make footwear components such as the shank or an outsole or both for a boot, particularly an industrial work boot. If the compositions contain a COFE material that provides an increase in the COF in Humid or are subjected to sufficient process conditions to provide an increase in COF in Humid or both, they are particularly suitable for applications such as certain pipes, industrial boot soles, fasteners for sports products, and automotive thermoplastic polyolefin (TPO) and vulcanized thermoplastic polyolefin (POS) for applications such as door handles, steering wheels and armrests. The latest compositions can also be very useful where the articles manufactured from them are going to be painted. A person skilled in the art can easily increase this list without undue experimentation. The elastomeric compositions of this invention are substantially free of crosslinking and comprise a CPO, an elastomeric EAO polymer, a plasticizer and, optionally, a COFE material. In the absence of crosslinking or curing, the elastomeric compositions should be substantially free of insoluble gels of the type previously referred to by W. K. Fischer. The compositions desirably have an EAO polymer content that is within the range of 50-80 pbw and a crystalline polyolefin content that is within the range of 50-20 pbw, both percentages are based on the combined weight of the polymer of EAO and the CPO. The amounts are preferably 60-80 pbw of EAO and 40-20 pbw of CPO. The quantities are chosen for a total of 100 pbw. The compositions also comprise from 1-200 pbw, preferably 50-150 pbw, per 100 pbw of EAO polymer of a plasticizer. The EAO polymers (also known as "ethylene polymers") that are suitable for this invention include interpolymers and diene-modified interpolymers. Exemplary polymers include ethylene / propylene (EP) copolymers, ethylene / butylene (EB) copolymers, ethylene / octene (EO) copolymers and ethylene / α-olefin / diene monomer (EAODM) interpolymers such as ethylene / propylene / diene monomer (EPDM) interpolymers. More specific examples include homogeneous branched, linear EAO copolymers (eg Tafmer ™ by Mitsui PetroChemicals Company Limited and Exact ™ by Exxon Chemical Company), homogeneously branched, substantially linear EAO polymers (eg, Affinity ™ polymers available from Dow Chemical Company and the Engage ™ polyolefin elastomers available from DuPont Dow Elastomers LLC and the Nordel® and Nordel® IP hydrocarbon rubbers (EPDM interpolymers) available from DuPont Dow Elastomers LLC The most preferred EAO polymers are those with a density (measured in accordance with US Pat. ASTM D-792) of 0.85-0.88 g / cc, especially 0.85-0.87 g / cc The EAO polymer desirably has at least one of (a) a viscosity, measured at a temperature of 200 ° C and at less a cutting speed of 200 sec "1, which is at least nine times greater than that of the crystalline polyolefin, b) a Mooney viscosity (ML? +4 a 125 ° C) of at least (>;) 20, and (c) a molecular weight distribution of (Mw / Mn) = 2.0. The Mw / Mn is preferably 2-5, more preferably 2-4. The Mooney viscosity is preferably > 50 more preferably > 70. An upper limit of the Mooney viscosity is stabilized, not by an absolute number, but by processing limits inherent in the equipment used to prepare the compositions of the present invention.

"Substantially linear" means that a polymer has a backbone substituted with 0.01-3 long chain branches per 1000 atoms in the backbone. "Long chain branching" or "LCB" means a chain length that exceeds that of a short chain resulting from the incorporation of the α-olefin into the backbone of an EAO polymer or EAO polymerization mixture. Although carbon-13 nuclear magnetic resonance spectroscopy (C13 NMR) can not distinguish or determine a current number of carbon atoms in the chain if the length is greater than six carbon atoms, the presence of the LCB can be determined, or at least estimated, from the MWD of the EAO polymer. It can also be determined from a melt flow ratio (MFR) or ratio (I10 / I2) of the melt index (IO) via ASTM D-1238 (190 ° C, 10-kg weight) to I2. "Interpolymer" refers to a polymer having at least two monomers polymerized therein. These include, without limitation, copolymers, terpolymers and tetrapolymers. It particularly includes a polymer prepared by the polymerization of ethylene with at least one comonomer, typically an α-olefin of 3-20 carbon atoms (C3-C2o), and preferably 3-10 carbon atoms (C3-C? 0). Examples of suitable α-olefins include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and styrene. Preferred copolymers include polymers of EP, EB, ethylene / hexene-1 (EH) and EO. Exemplary terpolymers include an ethylene / propylene / octene terpolymer as well as ethylene terpolymers, a C3-C20 α-olefin, and a non-conjugated diene monomer.

The non-conjugated diene monomer may have a polymerizable double bond as in 5-ethylidene-2-norbornene (ENB) or two polymerizable double bonds such as norbornadiene (NBD). The diene monomer is preferably selected from the group consisting of NBD, dicyclopentadiene, 1-hexadiene, piperylene, ENB and mixtures thereof. A terpolymer results from a choice of more than one C3-C2o α-olefin or more than one non-conjugated diene monomer. Those skilled in the art can easily select the appropriate monomer combinations for any desired interpolymer. "Elastomeric", as used herein, means an EAO polymer having a density that is beneficially less than > (<) 0.910 g / cc (grams per cubic centimeter), desirably > 0.900 g / cc, preferably < 0.895 g / cc, more preferably < 0.880 g / cc, more preferably still 0.850-0.880 g / cc, more preferably still 0.850-0.870 g / cc and one percent crystallinity < 33%, preferably < 29% and more preferably < 2. 3%. The density is preferably greater than (>) 0.850 g / cc. The percent crystallinity was determined by differential scanning calorimetry (DSC). SLEPs are characterized by a narrow MWD and a narrow short chain branching (SCBD) distribution and can be prepared as described in US Patents 5,272,236 and 5,278,272, the relevant portions of both are incorporated herein by reference. SLEPs exhibit outstanding physical properties by virtue of their narrow MWD and their narrow SCBD coupled to the LCB. USP 5,272,236 (column 5, line 67 to column 6, line 28) describes the production of SLEP via a continuous controlled polymerization process using at least one reactor, but allows multiple reactors, at a temperature and polymerization pressure sufficient to produce a SLEP that has the desired properties. The position preferably occurs via a solution polymerization process at a temperature of 20 ° C-250 ° C, using the restricted geometry catalyst (CGC) technology. Suitable CGC are described in column 6, line 29 to column 13, line 50 of USP 5,272,236. A preferred SLEP has a number of different characteristics, one of which is an ethylene content of 20-90 weight percent (% by weight), more preferably 30-80% by weight, with the remainder comprising one or more comonomers. The content of ethylene and comonomers are based on the weight of SLEP and are selected to achieve a total monomer content of 100% by weight. Additional distinctive SLEP characteristics include the melt index (I2) (ASTM D-1238, conditions 190 ° C, 2.16 kilograms (kg) weight (Condition E above)) and an MFR or I10 / I2. The interpolymers desirably have an I2 of 0.01-30 g / 10 min, more preferably 0.01-10 g / 10 min. The SLEP has an I10 / I2 (ASTM D-1238) >; 5.63, preferably 6.5-15, more preferably 7-10. For a SLEP, the I10 / I2 ratio serves as an indication of the degree of LCB so that a higher I? O / I2 ratio is equal to a higher degree of LCB in the polymer. SLEPs that meet the aforementioned criteria include, for example, polyolefin elastomers ENGAGE® and other polymers produced with a CGC by The Dow Chemical Company and OuPont Dow Elastomers L.L.C. Suitable CPOs include homopolymers of PP and copolymers of propylene with an α-olefin such as ethylene, 1-butene. 1-Hexene or 4-methyl-1-pentene or a mixture of a homopolymer and a copolymer. The α-olefin is preferably ethylene. The copolymer can be a random copolymer or a block copolymer or a mixture of a random copolymer and a block copolymer. Therefore, this component is preferably selected from the group consisting of PP homopolymers and P / E copolymers. This component has at least one of (a) an MFR (230 ° and 2.16 kg of weight) of at least 12 g / 10 min, preferably > 20 g / 10 min and (b) an Mw / Mn > 2.0. An upper limit for the MFR is 200 g / 10 min. The preparation of PP homopolymers and P / E copolymers also involve the use of Ziegler catalysts such as titanium trichloride in combination with aluminum diethylmonochloride, as described by Cecchin, USP 4,177,160. The polymerization process used to produce PP includes the suspension process, which is carried out at 50-90 ° C and 0.15-1.5 MPa (5-15 ° C).

ATM), and both monomer process in gaseous and liquid phase in which greater care must be taken to remove the amorphous polymer. Ethylene can be added to the reaction to form a polypropylene with ethylene blocks. PP resins can also be prepared using any of a variety of the metallocene, single site and restricted geometry catalysts together with their associated processes. Suitable plasticizers for use in the preparation of the compositions of the present invention are suitably selected from the group consisting of hydrocarbon oils and alkyl esters of a carboxylic acid. The hydrocarbon oils are preferably selected from naphthenic oils and paraffinic oils. Alkyl groups desirably contain 6-30 carbon atoms. Suitable carboxylic acids for use in the preparation of esters contain 1-4 carbon atoms of carboxylic acid. Illustrative esters include dioctylzealate, dioctylsebacate and n-butyltalate. The plasticizer is present in an amount of 1-200 pbw, based on 100 pbw of the elastomeric EAO polymer. The amount is desirably 20-200 pbw, preferably 50-150 pbw. The compositions of the present invention optionally contain a COFE material that increases the COF in Humid. The material, also known as "COFE Wet Material," is (a) selected from the group consisting of conventional adhesives and low molecular weight polymers, low crystallinity, low molecular weight propylene copolymers, and (b) are present in an amount greater than 0 pbw. Low MW, low crystallinity, suitable polymers include EAO polymers, especially EO copolymers. When used, a quantity of COFE material is desirably > 0 to 40 pbw, per 100 pbw combined weight of PO and elastomeric EAO polymer. The amount is preferably > 0 to 30 pbw, more preferably > 0 to 20 pbw. When the wet COFE material is a low molecular weight, low crystallinity polymer, the amount is sufficient to impart improved processability to the composition. The improved processability is determined by a reduction in the peak injection molding pressure, relative to a composition that is (1) subjected to the same processing conditions and (2) identical, except for the absence of the COFE material. Low MW polymers, of low crystallinity, also have distinctive characteristics. A low MW is a weight average molecular weight (Mw) of 500-25,000. The Mw is desirably 500-20,000, and preferably 500-15,000. Crystallinity is considered low when it is <; 20%, preferably from 0 to 15%, and more preferably from 0 to 10%. The low MW polymers also suitably have a Tb within the range of -40 to -65 ° C. The low MW, low crystallinity polymers, when present in the compositions of the present invention as a COFE material, provide an unexpected benefit in terms of improving the processability of such compositions. One means of demonstrating processability is to improve the peak injection molding pressures of compositions that differ only in the presence or absence of a low MW, low crystallinity polymer as a COFE material. The composition containing an amount of such a polymer sufficient to improve the wet COF of the compositions, also has a lower peak injection pressure than the composition lacking such a polymer. The substitution of a composition of the second aspect related to the second aspect by the composition containing the COFE material can produce a similar comparison. EAO polymers that have a bimodal or multimodal MWD are also effective as COFE materials as long as they have a low MW fraction that satisfies the aforementioned distinguishing characteristics. Since it is believed that the low MW fraction provides the COF improvement, those skilled in the art will understand that a greater amount of a bimodal or multimodal EAO polymer can be used to achieve an effect comparable to that of the low MW EAO polymer. "Adhesive", as used herein, is a generic term for any of several hydrocarbon-based compositions, often used to impart adhesiveness to a hot-melt adhesive composition. Some adhesives may also have a polar component. Illustrative adhesives include aliphatic C5 resins, polyterpene resins, dehydrogenated resins, mixed aliphatic and aromatic resins, mixed hydrogenated aliphatic and aromatic resins, tar resin esters and hydrogenated tar resin esters. An adhesive typically has a viscosity at 350 ° Fahrenheit (° F) (177 ° C), measured using a Brookfield viscometer, no greater than 300 centipoise (0.3 pascal-second) and a glass transition temperature (Tv) > 25 ° C. The Tv is preferably within a range of 25 ° C-120 ° C, more preferably 40 ° C-100 ° C. Commercially available conventional adhesives include aliphatic resins (AdTac, Piccotac ", and Piccopale" (Hercules Inc.)), aliphatic / aromatic resins (Hercotac® and Piccolyte® (Hercules, Ine,)), pure monomer resins (Endex, Piccolastic, Piccotex® and Kristalex® (Hercules, Inc.)), light-colored resins, both aliphatic and aromatic (Hercolite, Hercules, Inc.), pure, hydrogenated aromatic resins (Regalrez®, Hercules, Inc.), mixed aromatic resins, hydrogenated (Regalite, Hercules, Inc.), aromatic resins (Picioe, Piccodiene®, Piccovar "AP and Piccovar * L (Hercules, Inc.)), polyterpene resins (Piccolyte® A, Piccolyte® C and Piccolyte® S ( Hercules, Inc.)), Ester Resins (Foral®, Hercules, Inc.), the line of Escorez adhesives (Exxon Chemical) and the Wingtack adhesive line (Eastman Chemical). The above list is for illustration only and should not be considered an exhaustive list. Those skilled in the art can easily select other adhesives. The -OCF increase, particularly the increase in wet COF, occurs when a compound plus a COFE material has a wet COF greater than that of the compound alone. A COF of 0.4 or more is particularly desirable for certain applications such as industrial boot soles and work boots. A wet COF of 0.3 or higher, especially 0.35 or higher, provides very satisfactory results for other applications such as equipment handles for golf clubs, tennis rackets, racquetball rackets and other sports products. The compositions of this invention can be compounded with a filler or filler (reinforcing, non-reinforcing or both) in an amount of 0-70 pbw, based on 100 combined parts by weight of EAO polymer and CPO. In addition, a pigment can also be added. Suitable fillers and reinforcing agents include glass, silica, carbon black, metal carbonates, such as calcium carbonate, metal sulfates, such as calcium sulfate, metal oxides, such as magnesium oxide and zinc oxide, talc, clay and graphite fibers. A variety of conventional special additives may advantageously be used in the compositions of this invention. The additives include antioxidants, surface tension modifiers, antiblock agents, lubricants, antimicrobial agents such as organometallic, isotazolone, organoazulf and mercaptan; antioxidants such as phenolic compounds, secondary amines, phosphites and thioesters; antistatic agents, such as quaternary ammonium compounds, amines and ethoxylated, propoxylated, or glycerol compounds, hydrolytic stabilizers; lubricants such as fatty acids, fatty alcohols, esters, fatty amides, metal stearates, paraffinic and microcrystalline waxes, silicones and esters of orthophosphoric acid; mold release agents, such as fine or pulverized particulate solids, soaps, waxes, silicones, polyglycols and complex esters such as trimethylolpropane tristearate, pentaerythritol tetrastearate, pigments, dyes and colorants, plasticizers such as dibasic acid esters (or its anhydrides) with monohydric alcohols such as o-phthalates, adipates and benzoates; thermal stabilizers such as organotin mercaptides, octyl esters and thioglycolic acids and a barium or cadmium carboxylate; ultraviolet light stabilizers used as a hindered amine, an o-hydroxy-phenylbenzotriazole, a 2-hydroxy-4-alkoxybenzophenone, a salicylate, a cyanoacrylate, a nickel chelate and a benzylidene malonate and oxalanilide. A preferred hindered phenolic antioxidant is Irganox ™ 1076 (Ciba-Geigy Corp.). Each of the above additives, if used, typically does not exceed 5% by weight, based on the total weight of the composition. The compositions of this invention can be manufactured in parts, sheets or other forms, using any of a number of conventional procedures for the processing of elastomers. The compositions can also be formed, drawn into films, multi-layered sheets or extruded sheets, or they can be compounded with one or more organic or inorganic substances, on any suitable machines for such a process. The elastomeric compositions of this invention have a continuous or co-continuous phase formed from the CPO. Compositions lacking a COFE material or wet process COF improvements related to the process, have surprisingly improved properties, particularly abrasion resistance (ASTM D 1630-83, Abrasive NBS), in relation to the compositions prepared from the same components, but without a continuous phase of EAO.

The addition of a COFE material to a composition results in some loss of abrasion resistance relative to that of the composition without COFE material. Similarly, elastomeric compositions having an improved wet COF, as a result of certain process conditions, also suffer from some loss of abrasion resistance. Surprisingly, however, the seam tear strength (average in pounds per linear inch (pli) according to the American Footwear Institute's test method number FIA-326) is not adversely affected by such conditions. of process. The preparation of the elastomeric compositions of the present invention comprises subjecting a combination of a CPO, an elastomeric EAO, a plasticizer and, optionally, a COFE material at cutting conditions by temperature and pressure sufficient to form a two-phase mixed composition. The CPO, the EAO, the plasticizer and the COFE material, as well as the quantities of each, are all as described above. The CPO and each EAO form a phase. The CPO phase of the two phase mixture is at least co-continuous with the EAO polymer phase. The conditions of temperature, cut and to a lesser degree pressure, are sufficient to convert the CPO and the EAO to a molten state and at least partially intermix the CPO and the EAO in their molten states. Although any apparatus for processing conventional melt can be used, extruders, especially twin screw extruders, provide desirable results. Those skilled in the art recognize that the conditions of temperature, cut and pressure vary from one processing apparatus in the molten state to another. For example, when using a 30 mm twin screw extruder, instead of a 90 mm twin screw extruder, the barrel temperature parameters and the rpm parameters of the extruder screw should be higher in the extruder than in the extruder. mm than in the 90 mm extruder to achieve equivalent results. One skilled in the art can easily determine satisfactory variations of such parameters without undue experimentation. The examples and comparative examples presented below can be used as a guide for such a determination. A process variation that allows one to prepare a two phase mixed composition with an improved Wet COF without using a COFE material comprises two stages. In step one, the EAO and the CPO are subjected to conditions of temperature, cut and pressure sufficient to form a first molten mixing composition. The composition can be recovered converted to pellets or other suitable feed form and then fed, in two stages, to a second melt processing apparatus where it is returned to a molten state. An alternative step two allows the composition to be fed directly to the second melt processing or melt processing apparatus, without an intermediate recovery step, and maintained in the molten state. In any case, the plasticizer is added to the first mixed, melted composition, while the latter moves to the second apparatus in the molten state. With this process variation, the resulting phase two has a Wet COF that exceeds that of a two-phase composition prepared by subjecting the CPO, EAO and plasticizer to a single pass through the same melt processing apparatus. The variation of the process desirably uses the same combination of temperature, cut and, where appropriate, pressure in each apparatus where the apparatuses are substantially identical. A combination of conditions for a 30 mm twin screw extruder is a screw speed of the extruder of 400 rpm and adjustments or temperature parameters of the barrel sufficient to provide a melting temperature of the polymer > 330 ° C. As noted above, changes in the type of device and size require an adjustment of the operating parameters. The identification of a phase as continuous or co-continuous can be carried out quickly via TEM. This technique involves the sectioning with cryogenic microtome of a sample. The microtome surface of the sample is then stained (exposed to steam) using a 0.5 wt% aqueous solution of ruthenium tetraoxide. The sample is examined and photographed below using a TEM (JEOL 2000Fx). The amplification is typically set for >; 7, 500 X. The examples presented below demonstrate the improved abrasion resistance of the compositions representing the present invention. The elastomeric compositions also have an improved thermal resistance before treatment (also known as "solidification in the mold"), as measured by Dynamic Mechanical Spectroscopy ("DMS"), in relation to the chloride block copolymers. polyvinyl and styrene formulated. It is believed that the compositions of the present invention also provide improved thermomechanical properties at elevated temperatures (e.g., 100-120 ° C), such as deformation under load tests and other thermomechanical analyzes. The following examples illustrate but not, either explicitly or implicitly, limit the present invention. Unless otherwise stated, all parts and percentages are by weight, based on total weight. The Arabic numerals identify Examples (Ex) of the present invention and the letters of the alphabet represent the comparative examples (Ex Comp). Table I below provides data on physical properties for the different materials used to prepare compositions for a number of Ex and Ex Comp. EAO-1 through EAO-6 were prepared by or available from DuPont Dow Elastomers L.L.C. and EAO-7 and EAO-8 are available from The Dow Chemical Company. The EAO-1 is an EO polymer (Engage® 8180) that has an I2 of 0.5 g / 10 min and a density of 0.863 g / cc. EAO-2 is a development ethylene / propylene / ethylidene norbornene (ENB) polymer that has an ENB content of 0.5%. The EAO-3 is a developmental ethylene / propylene / ENB polymer that has an ENB content of 0.5%. EAO-4 is an ethylene / propylene / 1,4-hexadiene polymer (Nordel® 2470) having a 1,4-hexadiene content of 6.0%. The EAO-5 is an experimental EO copolymer having a Mooney viscosity (ML? +4, 125 ° C) of 70 and a density of 0.87 g / cc. The EAO-6 is a polyolefin elastomer (POE) (Engage® 8842) that has an I2 of 1 g / 10 min and a density of 0.858 g / cc. The EAO-7 is a linear low density polyethylene (LLDPE) Dowlex® IP-90). The EAO-8 is also LLDPE (Dowlex® IP 60).

PP-1 is a PP homopolymer (Profax® 6323, Himont). PP-2 is a homopolymer of PP (PD 701, Himont). PP-3 is a PP homopolymer (Valtec® HH 444, Himont). Pl-1 is a high viscosity paraffinic oil (Sunpar® 2280, Sun Oil Co). Pl-2 is a low viscosity paraffinic oil (Tufflo® 10, Lyondell Co.). Fi-1 is clay filler from calcined kaolin, surface treated (Translink® 37, Engelhard). The viscosity values (vise), in poises, were determined from the curves of log shear rate versus viscosity generated by dynamic mechanical spectroscopy using an instrument such as those available from Rheometric Intruments. The viscosity values shown in Table I were determined at 200 sec-1 by extrapolation from the curves of log shear rate versus viscosity at 200 ° C using parallel plates of 25 millimeters (mm). The viscosity of Mooney (MV) ML? +4 at 125 ° C for the EAO polymers and the melt flow rate (MFR) (g / 10 min) at 230 ° C with a weight of 2.16 kg for the polymers of PP help to characterize the starting materials.

Table I - means that it was not measured EX 1-7 AND EX COMP A AND B Nine sample compositions (Ex 1-7 and Ex Comp A-B) were prepared, from the compositions shown in Table II.

Table II * means a combination of 35.6% of EAO-5, 5% of EAO-6 and 1.75% of EAO-8 Examples 1-4 and Comparative Examples A-B were prepared in a small laboratory scale Farrel Banbury Mixer. For each Example and Comparative Example, the EAO polymer was added to the mixer at 130 ° C and melted at a rotor speed of 80 revolutions per minute (rpm) for two minutes. The plasticizer was then added, with continuous mixing, for a period of two minutes. The PP polymers were then added to the mixer and the temperature was increased by the addition of coupled steam with an increase in rotor speed at 180 rpm. Hours later, the contents of the mixer were removed, rolled on a sheet, and then granulated by injection molding test specimens. Examples 5 and 6 were prepared using a 30 mm ZSK twin screw extruder, co-rotator, Werner and Pfleiderer. The EAO polymer, the PP polymer and the filler were mixed dry in a drum mixer before being added to the extruder using a calibrated feeder. The extruder operates at a speed of 200 rpm to effectively melt dry granules and provides a die pressure of 300 pounds per square inch (psi) (2070 kilopascals (kPa)). Zones 1-5 were set, respectively, at 140 ° C, 110 ° C, 170 ° C, 180 ° and 190 ° C and the extruder die was fixed at 190 ° C. The plasticizer was added to zone 2 of the extruder using a calibrated pump and an injection nozzle. The extrudate passes from the extruder through a double-stranded matrix to a water bath (130 ° C), where it is tempered. The extrudate exits the water bath, is dried with an air knife and then granulated. Example 7 was prepared using the same apparatus as in Examples 5 and 6, but with the extruder operating at 240 rpm instead of 200 rpm, and with different parameters or temperature settings. For a first pass through the extruder, during which plasticizer was not added, the parameters or temperature settings for zones 1-5 are, respectively, 150 ° C, 160 ° C, 185 ° C, 185 ° C and 185 ° C, and the extruder die was fixed at 180 ° C. For the second pass through the extruder, during which the plasticizer was added. to zone 2, all temperatures were set at 175 ° C. After the second pass, the extrudate was processed as in Examples 5-6. The compositions prepared for Examples 1-7 and Comparative Examples A-B, were converted into injection molded test specimens or plates having an area of 154.8 square centimeters (cm2) and a thickness of 0.312 cm. The plates were produced using an Arburg Model 370C-800-225 oscillating screw injection molding machine (800 kilonewtons (kN) hydraulic clamping force (30 mm screw) with fixed barrel temperature in a profiled shape with a first zone of the barrel at 121 ° C, the subsequent zones, sequentially at 177 ° C, 196 ° C and 204 ° C, and a nozzle set at 185 ° C. A plate molding temperature, although set at 18 ° C, is typically 21 ° C during molding. The angular velocity of the screw, the injection pressure and the clamping pressure are, respectively, 30 meters / minute, 400-700 bar (40-70 megapascals (MPa)) and 30 bar (3 MPa). The firing volume of 80 ce is directed to each plate during an injection time of 1.9-2.1 seconds. The cooling time of the mold is 20-30 seconds. The specimens were tested for physical properties to determine NBS Abrasion Resistance (ASTM D-1630), tensile strength at break (psi / kPa) and percent elongation (%) at break. The physical property data are shown in Table II below. For comparison purposes, the crosslinked rubber (NBS reference material) has an NBS abrasion value of 100.

Table III Table III (Continued) The data presented in Table III demonstrate that compositions with viscosity ratios of 9 or greater have a superior abrasion resistance in relation to similar compositions with lower viscosity ratios. See, for example, Comparative Example A to Example 1. Similar results are expected with other EAO polymers, CPO, plasticizers and, where appropriate, additives such as fillers, pigments, stabilizers, all of which were described above. .

The thermal resistance data before treatment can be illustrated by determining the storage module of a composition at a temperature of 130 ° C (8 mm parallel plates), using a DMS from Rheometric Scientific. The storage module for Example 6 is 798,000. dynes / square centimeter (dynes / cm2) (8137 kilograms / square meter (kg / m2) The storage module for a polyvinyl chloride composition, a styrene block copolymer composition, both typically used in the manufacture of polystyrene blades boots, and Comparative Example A are, respectively, 598,000 dynes / cm2 (6098 kg / m2), 173,000 dynes / cm2 (1764 kg / m2), and less than 5,000 dynes / cm2 (51 kg / m2). that the compositions of the present invention compare very favorably with the commercially available materials and provide a remarkable improvement over similar compositions with a lower viscosity ratio Similar results are expected with the other compositions representing the present invention.

EXAMPLES 8-12 and COMPARATIVE EXAMPLE C Examples 8 and 9 were prepared using the procedure and apparatus of Examples 5-6, but with temperatures for zones 1-5 and the extruder die fixed, respectively, at 140 ° C, 160 ° C, 165 ° C, 170 ° C, 165 ° C and 160 ° C. The compositions of Examples 8-9 are shown in Table IV below. A Haake 9000 twin screw extruder, equipped with a cold water bath, was used to prepare Examples 10-12. Zones 1-5 and 6 (extruder matrix) were set, respectively, at 140 ° C, 160 ° C, 170 ° C, 170 ° C, 160 ° C and 150 ° C. Examples 10 and 11 are, respectively, combinations of 100 pbw of the compositions of Examples 8 and 9 with 10 pbw of COFE-1. Example 12 is a combination of 100 pbw of the composition of Example 8 and 10 pbw of COFE-2. When present, the COFE compounds are dry blended with the compositions before being melt processed using the extruder. Comparative Example C is injection molded as received. Comparative Example C is a styrene-butadiene-styrene compound (SBS-1), sometimes used for shoe applications, and which is available from A-W Compounding Ltd. under the trade designation TR2046. COFE-1, used as a compound to improve COF, is Regalite® SlOl, an adhesive (hydrogenated mixed aromatic resins), available from Hercules, Inc. COFE-2 is a developmental EO polymer (DuPont Dow Elastomers LLC ) that has a bimodal MWD (50% of an Mw of 200,000 with a density of 0.867 g / cc and 50% of an Mw of 12,000 with a density of 0.862 g / cc, with a total density of 0.865 g / cc and a MI of 3.0 g / 10 minutes).

Table IV The compositions of Examples 8-12 and Comparative Example C were converted into injection molded test plates using the method and apparatus of Examples 1-7. The processibility by injection molding was quantified during the production of the test plates. The size of the shot and the position of the screw at which the process switches from injection to holding, was adjusted to the highest injection speed to be evaluated so that the cavity was completely empty. The temperatures of the injection molding apparatus are the feed temperature of 250 ° F (121 ° C) for zone 1 (feeding zone), 350 ° F (177 ° C) for Zone 2, 385 ° F (196 ° C) for Zone 3, 400 ° F (204 ° C) for Zone 4 and 385 ° F (196 ° C) for nozzle. The time to fill the cavity at this point and the peak injection pressure were recorded at various injection speeds (5, 8, 10, 15, 20, 30, 50 and 70 cc / second). The peak injection pressure was plotted against the apparent shear rate (see Table VI) in the test. The apparent shear rate was calculated using the injection speed and the physical dimensions of the mold. The peak injection pressure (see Table VI) resulting from the fixed injection speed was used as an indication of the processability, since it is a response of the process that depends on the melt viscosity, the injection speed and the speed of solidification of the flow front. Those skilled in the art of injection molding will recognize that the injection pressures are found by the clamping tonnage in a molding machine. They will also recognize that unsuccessful injection molding resins will generate an injection pressure that exceeds the available clamping tonnage before the mold cavity is filled to the highest practical melt temperature. When the peak pressure exceeds the holding tonnage, evaporation occurs. Therefore, a compound that generates a significantly lower injection pressure at a given injection speed (shear rate) than another resin is considered more processable. The test plates representing Examples 8-12 and Comparative Example C were subjected to the analysis and physical properties test to determine the COPF on tiles with a thickness of less than 18 mm dry and wet, Resistance to NBS Abrasion, Resistance to DIN Abrasion, Hardness (Shore A) and injection molding viscosity at eight different cutting speeds. The coefficient of friction test (COF) was carried out in accordance with ASTM D-1894 using tiles with a thickness greater than 18 millimeters (dry and wet). Abrasion Resistance NBS was determined as in Example 1-7. The DIN abrasion (volume loss measurement) was determined according to test method DIN 53516. The Hardness test (Shore A) was carried out in accordance with ASTM D-2240. The physical properties test data are summarized in Table V below.

Table V Table VI -means that it was not measured The data presented in Table V demonstrate that the addition of a COFE compound increases the COF in the wet without any significant adverse effect on the remaining physical properties. COFE-2, which has only 50% by weight of a low molecular weight fraction, effectively provides 5% by weight of a compound that improves COF. If the amount of COFE-2 is doubled, as shown in Ex 15, further improvements in the wet COF are evident. If the COFE-2 is replaced by at least a portion of EAO-6, improvements in the wet COF are also expected. The data presented in Table VI demonstrate that the addition of a COFE compound does not adversely affect the molding flow characteristics of the compounds. This is surprising since the addition of a COFE compound effectively reduces the relative amount of plasticizer. In Exs 10 and 11, compositions containing COFE material have improved flow characteristics in relation to, respectively, Ejs 8 and 9. As noted above, the improved flow characteristics (improved processability) are evident from a lower peak injection pressure during injection molding at the same injection speeds. In other words, some compounds containing COFE are easier to mold by injection than comparable compositions lacking a COFE compound.

EJ 13-17 Five additional examples were prepared using the apparatus and procedures set forth in Exs 10-12 for Exs 15-17 and the apparatuses and procedures outlined in Exs 5-6 for Exs 13-14. The Exs 13 and 14 reproduce, respectively, the Exs 10 and 11, but with 5 more than 10 pbw of COFE-1 and 95 instead of 90 pbw of, respectively, the compositions of the Exs 8 and 9. The Ex 15 reproduces Ex 12, but with 20 instead of 10 pbw of COFE-2 and 80 instead of 90 pbw of the composition of Ex 8. Ejs 16 and 17 reproduce in Ex 10, but with COFE-3 (Ex 16) or COFE-4 (Ex 17) instead of COFE-1. COFE-3 is a low MW EO copolymer (numerical average molecular weight (Mn) of 9200), experimental, (DuPont Dow Elastomers L.L.C.) which has a density of 0.870 g / cc and an effective MI of 1770 g / 10 min. COFE-4 is Hercotac® 1148, an adhesive (a mixture of petroleum-derived monomers, natural monomers or both with a Tv of 44 ° C, an Mw of 1500 and an MWD of 1.9) available in the form of Hercules granules, Inc. Tables VII and VIII represent, respectively, data from the physical properties tests for Exs 13-17 and peak injection pressure data for Exs 15-17. Although not shown, it is expected that the peak injection pressure data for Ex 13 will be intermediate between the values presented above for Exs 8 and 10. Similarly, the data for Ex 14 are expected to be intermediate between values presented above for Exs 9 and 11. Table VII -means that Table VIII was not determined Table VIII (continued) The data presented in Tables VII and VIII demonstrate the effectiveness of the different levels of adhesives and the different adhesives in improving the wet COF of the polymeric compositions of Exs 13-17. Certain adhesives and quantities of adhesives provide greater COF improvement than others. Similar results are expected with other polymers, polymer compositions, adhesives (either conventional or low MW polymers) and additives, all of which were described above. Those skilled in the art can easily select the appropriate compositions and adhesives as well as the relative amounts of each component necessary to achieve the desired desired wet COF.

EJS 18-19 and EJ COMP D Two additional examples and a comparative example were prepared using a composition including 60.3% of EAO-4, 26.6% of PP-2, 8.5% of EAO-6, 2.9% of EAO-8, 1.6% of Fi-1, and 0.1% of Irganox® 1076 (hindered phenolic antioxidant, Ciba-Geigy Corp). The composition was subjected to three different sets of process conditions. All using a 90mm Berstorff twin screw extruder instead of the 30mm twin screw extruder of the Ejs 5-6. Zones 1-6, the screen magazine body, the transition zone and the extruder die were set, respectively, to 490 ° F (254 ° C), 440 ° F (226.7 ° C), 545 ° F (285.0 ° C), 500 ° F (260.0 ° C), 400 ° F (204.4 ° C), 590 ° F (310.0 ° C), 420 ° F (215.6 ° C), 425 ° F (218.3 ° C) , and 450 ° F (232.2 ° C). The extruder operates at 250 rpm, which, in combination with the above temperatures, effectively produces a polymer melting temperature of 430 ° F (221.1 ° C). An underwater granulator Gala converts the molten polymer into granules. Comp Ex D represents the composition processed through the extruder without the addition of plasticizer. Ex 18 feeds the same composition to the extruder, but modifies the procedure used with Ex Comp D by injecting enough Pl-2 into Zone 3 to provide a finished product with a plasticizer content of 41%. Ex 19 adds the granules of Comp D Ex to the feed throat of the extruder and then feeds into Zone 3 the same amount of plasticizer as in Ex 18. The compositions of Exs 18-19 are converted to molded test plates. by injection as in Ejs 1-7 and subjected to the analysis of physical properties as in Exs 8-12. Seam tear strength measured in pounds per linear inch (pli) according to the test method of the American Footwear Institute FIA-326. The data of the physical properties tests are summarized in Table IX below. Peak injection pressure data were determined as in Exs 8-12 for Exs 18-19 and Ex Comp D as shown in Table X below.

Table IX Table IX (continued) Table X Table X (continued) The data presented in Tables IX and X demonstrate several points. First, the data in Table X show that, for a given composition, a procedure of two steps (Ex 19) provides improved flow characteristics in relation to a one-pass procedure (Ex 18). Second, the data in Table X show the beneficial effect of including a plasticizer. See, Comp D without plasticizer 'Ej versus Ej 18 and Ej 19 with a plasticizer lb. Third, the data in Table IX show that an improvement in the COF in Humid (tiles with a thickness greater than 18 mm) accompanies a decrease in the resistance to abrasion. Surprisingly, however, the resistance to tearing by stitching remains almost constant. Similar results are expected with other compositions and process conditions, all of which are described above. Those skilled in the art can easily choose the process conditions to provide a balance desirable between the flow properties and the COF in Wet on the one hand and the abrasion resistance on the other hand.

Example 2 - = 22 The composition of Comparative Example D was processed as in Example 5-6, except for the increase of screw speed of the extruder for the twin screw extruder of 30 mm at 400 rpm and using the uniform settings of the barrel temperature of 280 ° C (Example 20), 310 ° C (Example 21) and 330 ° C (Example 22). The settings provide the respective polymer melting temperatures of 302 ° C, 335 ° C and 356 ° C. The data of the injection molding test is shown in Table XI below, together with those of Comparative Example D. ? aL l®? X (Co .i.mum.tgi.?) The data in Table XI show that changes in the fusion processing apparatus require alterations in the parameters of the apparatus to achieve almost equivalent results. The data for Example 22 is close to that of Comparative Example D. To achieve such data, the temperature of the melt processing for a 30 mm twin screw extruder must be 330 ° C. As with Examples 18 and 19, the addition of a plasticizer should provide a dramatic reduction in peak pressure measurements. Similar results are expected with other compositions and process conditions, all of which were described above. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (15)

Having described the invention as above, the content of the following claims is claimed as property

1. An elastomeric composition, characterized in that it consists essentially of: a. 20 to 50 parts by weight, based on the combined weight of a and b, of a crystalline polyolefin selected from the group consisting of polypropylene homopolymers and propylene / ethylene copolymers; b. 80 to 50 parts by weight, based on the combined weight of a and b, of an elastomeric ethylene / alpha-olefin polymer, the polymer optionally has polymerized therein a diene monomer; c. l to 200 parts by weight, per 100 parts by weight of elastomeric polymer, of a plasticizer, the plasticizer being selected from the group consisting of hydrocarbon oils and alkyl esters of a carboxylic acid; and optionally, d. from more than 0 to 40 parts by weight, per 100 parts by weight of a and b, of a material that provides an increase in the coefficient of friction in wet, measured in accordance with ASTM D-1894, using a tile with a greater thickness of 18 millimeters, on the coefficient of wet friction of a composition that includes only a, b and c; The composition is substantially free of crosslinking or insoluble gels, the ethylene / alpha-olefin polymer having a viscosity, measured at a temperature of 200 ° C and a cutting speed of 200 sec-1, which is at least nine times higher than that of the crystalline polyolefin. The composition according to claim 1, characterized in that the crystalline polyolefin has at least one of (a) a melt flow rate, determined at a temperature of 230 ° C with a weight of 2.16 kg, of at least 12 g / 10 min and (b) a molecular weight distribution (Mw / Mn) of at least 2.0. 3. The composition according to claim 1, characterized in that the ethylene / alpha-olefin polymer has at least one of (a) a Mooney viscosity (ML? +4 at 125 ° C) of at least 20, and ( b) a molecular weight distribution (Mw / Mn) of minus 2.0. 4. The composition according to claim 3, characterized in that the ethylene / alpha-olefin polymer has a Mooney viscosity of minus 70. The composition according to any of claims 1-4, characterized in that the polymer ethylene / alpha-olefin is a terpolymer of ethylene / alpha-olefin diene monomer, the diene is selected from the group consisting of norbornadiene, dicyclopentadiene, 1,4-hexadiene, piperylene, or 5-ethylidene-2-norbornene and mixtures thereof. 6. The composition according to claim 1, characterized in that the ethylene / α-olefin polymer has polymerized therein, at least one α-olefin comonomer, the α-olefin contains from 3 to 20 carbon atoms. The composition according to claim 1, characterized in that the plasticizer is a hydrocarbon oil selected from the group consisting of naphthenic oils and paraffinic oils. The composition according to claim 1, characterized in that it consists essentially of a filler in an amount within a range of 0 to 70 parts by weight, based on the combined weight of a and b, the filler is selected from the group consisting of glass, silica, carbon black, metal carbonates, metal sulfates, metal oxides, talc, clay and graphite fibers. The composition according to claim 1, characterized in that the crystalline polyolefin and the ethylene / alpha-olefin polymer are present as two distinct phases, the phase of the crystalline polyolefin is at least co-continuous with the ethylene polymer phase / alpha-olefin, the composition has an abrasion resistance (ASTM D 1630-83, BS Abrasive) which is higher than that of a similar composition prepared from the same components, but with a single continuous phase formed from ethylene polymer / a-olefin. 10. The composition according to claim 1, characterized in that the wet COFE material is (a) selected from the grconsisting of polymer adhesives of low crystallinity and molecular weight, different from the low molecular weight propylene copolymers, and (b) are present in a greater amount of 0 parts by weight, the amount it imparts, when the COFE-wet material is a polymer of low crystallinity, of low molecular weight, improved processability to the composition as determined by a reduction in the peak injection molding pressure, in relation to a composition that is (1) subjected to the same process conditions and (2) identical, except for the absence of the COFE material. 11. A process for preparing an elastomeric composition, the process is characterized in that it comprises submitting a combination of: a. 20 to 50 parts by weight based on the combined weight of a and b, of a crystalline polyolefin selected from the grconsisting of polypropylene homopolymers and propylene / ethylene copolymers; b. from 80 to 50 parts by weight, based on the combined weight of a and b, of an elastomeric ethylene / alpha-olefin polymer, the polymer optionally has polymerized therein a diene monomer; c. from 1 to 200 parts by weight, per 100 parts by weight of the elastomeric polymer, of a plasticizer, the plasticizer is selected from the group consisting of hydrocarbon oils and alkyl esters of a carboxylic acid; and optionally, d. from 0 to 40 parts by weight, per 100 parts by weight of a and b, of a material that provides an increase in the coefficient of friction in wet, measured in accordance with ASTM D-1894, using a wet tile with a greater thickness of 18 millimeters, and on the coefficient of wet friction of a composition including only a, b and c, for temperature, cut and pressure conditions to form a two-phase mixed composition, wherein the crystalline polyolefin is at least one continuous phase with the phase of the ethylene / alpha-olefin polymer; The composition is substantially free of crosslinking or insoluble gels, the ethylene / alpha-olefin polymer has a viscosity, measured at a temperature of 200 ° C and a cutting speed of 200 sec-1, which is at least nine times greater than that of the crystalline polyolefin. 1

2. The process according to claim 11, characterized in that a and b are subjected to temperature, cut and pressure conditions to form a first mixed, molten composition, after which the first mixed, molten composition and c are subjected to of temperature, cut and pressure to form the two-phase mixed composition, the two-phase composition has a COF in Moisture greater than that of the two-phase composition formed by subjecting a combination of a, b and c to a single iteration and to temperature conditions , cut and pressure. The process according to claim 12, characterized in that the conditions used to form the first mixed, melted composition and the conditions used to form the two-phase composition from the first mixed, melted composition are the same. The process according to claim 13, characterized in that the cutting, pressure and temperature conditions are provided by a 30 mm twin screw extruder operating at a textrusor screw speed of 400 rpm with temperature setting of the barrel elevating the first melted, mixed composition and the two-phase composition to a melting temperature of at least 330 ° C. 15. A article of manufacture, characterized in that it has at least one component thereof, made of the composition according to any of claims 1-10, the article has (a) an abrasion resistance (ASTM D 1630-83, Abrasive NBS), which is greater than that of a similar article prepared from the same composition, but with a single continuous phase formed from the ethylene / α-olefin polymer and, when the d component is present, a .COF , measured in accordance with ASTM D-1894 using a wet tile with a thickness greater than 18 millimeters, of at least 0.3, preferably of at least 0.4. H SiaiüW B3E S ^ LUMVÍIMe? TSf An elastomeric composition that provides excellent abrasion resistance, and is useful for producing fabricated articles, includes a plasticizer and a crystalline polyolefin phase that is continuous or co-continuous with the ethylene / α-olefin polymer phase. Certain compositions also contain a material that improves the wet COF of the composition, and in some cases, the processability of the compositions. Other compositions obtain the same improvement by choosing the process conditions. The resulting articles also have an improved wet COF.