WO2003042296A2 - Blends of olefin interpolymers and urethane polymers and method of making same - Google Patents

Abstract

A polymer blend or mixture comprises a substantially random olefin interpolymer and a urethane polymer, wherein the blend is substantially free of a compatibilizer. In some embodiments, the urethane polymer is mixed with the olefin interpolymer in the form of fibers, and the fibers are dispersed in a matrix of the olefin interpolymer. In other embodiments, a thermoplastic urethane polymer is blended with the olefin interpolymer to form a relatively homogeneous mixture. Various products are made from the blends or mixtures in accordance with embodiments of the invention.

Description

BLENDS OF OLEFIN INTERPOLYMERS AND URETHANE POLYMERS AND METHODS OF MAKING SAME

FIELD OF THE INVENTION This invention relates to blends of olefin copolymers and urethane polymers. More particularly, the invention relates to blends of α-olefin/vinyl aromatic copolymer (e.g., ethylene styrene interpolymers) and thermoplastic urethane. The invention also relates to methods of making and using the blends to manufacture various articles.

BACKGROUND OF THE INVENTION Commercial applications of thermoplastic polyurethane (TPU) continue to grow at a rapid pace. Unlike their thermoset relatives, thermoplastic polyurethanes can be processed in a manner similar to other thermoplastics in operations such as extrusion, injection molding, slush-molding, wire coating, etc. In addition to its desirable processability, TPU finds applicability in a wide variety of end use applications because of its optimum combination of performance properties.

For example, TPU is desirable because of its hardness, tensile strength, modulus, flexibility, mar and scratch resistance, paintability, and/or tensile elongation. The combination of such physical properties and a ready adaptability to a wide variety of processing and molding parameters results in the use of TPU in numerous end use applications, especially in many consumer goods.

As a result of its use in consumer goods, in addition to good processing and performance properties, commercially desirable TPU formulations should be visually appealing, and maintain such desirable visual characteristics over the lifetime of the part. In consumer applications, this often translates into a desire for TPU compositions capable of exhibiting good UV resistance and heat stability.

With respect to heat stability, the TPU composition should not yellow or dull upon exposure to the temperatures normally encountered upon typical TPU composition processing. Typical processing temperatures reach between 380 °F. to 420 °F. and often result in a light yellow or dull appearance of the final TPU composition containing product. In addition, the part should not yellow or dull upon long term exposure to moderate and higher temperatures encountered during its lifetime. Typical temperatures which may be encountered during part use are from 23 °C. to 80 °C . A yellowed or dulled appearance is detrimental, and in many consumer and automotive applications, unacceptable. Once a heat stable TPU composition has been achieved, the visually pleasing appearance of the TPU containing product should be maintained over the lifetime of that particular product. That is, upon exposure to outdoor light, and in particular, ultraviolet light, the final product should not exhibit yellowing, dulling, chalking, whitening, or blushing. In some other applications, a soft touch surface is important.

Thus, it would be desirable to provide a TPU composition which possesses good processability and performance characteristics while still exhibiting good heat stability and resistance to UV degradation. Such a TPU composition would be particularly desirable for use in consumer and automotive applications. Blends of thermoplastic materials, such as polyurethanes blended with polyvinyl chloride or nitrile rubber, have been used for a variety of applications. Such blends are useful for applications such as coated fabrics, molded products, etc. However, many of these materials have relatively high processing temperatures and are difficult to handle for this reason. Specialized equipment is required for manufacturing these materials into a final product. If the processing temperatures of these thermoplastic materials could be reduced without sacrificing the performance of such materials, it would be possible for the manufacturer to obtain substantial savings in energy costs, or, for the same expenditure of energy, to obtain end products of higher quality more easily or more rapidly.

For the foregoing reasons, there is a need for the development of an improved process to produce parts which possess soft touch. There is also a need for engineering thermoplastic materials with a beneficial balance of processability, good aesthetics with no pearlescence and, preferably having advantageous property profiles, such as mechanical strength, impact resistance, creep and chemical resistance, mar and scratch resistance, thermoformability, and/or toughness . SUMMARY OF THE INVENTION

The aforementioned need is fulfilled by one or more aspects of the invention. In one aspect, the invention relates to a blend of a substantially random olefin interpolymer and a urethane polymer. Moreover, the blend is substantially free of a compatibilizer. Preferably, the olefin interpolymer is compatible with the urethane polymer. The substantially random olefin interpolymer comprises:

(1) first polymeric units derived from; (i) at least one vinyl aromatic monomer, or

(ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or

(iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, and

(2) second polymeric units derived from at least one C _-20 α-olefin; and optionally

(3) third polymeric units derived from one or more ethylenically unsaturated polymerizable monomers other than those of (1) and (2). wherein the blend is substantially free of a compatibilizer. Various articles of manufacture, such as co-extruded parts and injection molded parts, can be made from the polymer blend.

In another aspect, the invention relates to a method of making a useful article, comprising: (a) obtaining a polymer mixture comprising polyurethane fibers dispersed in a matrix of a substantially random olefin interpolymer, the mixture being calenderable or extrudable; and (b) forming a film or a sheet from the polymer mixture, wherein the substantially random olefin interpolymer is described above. Water-permeable or breathable films or sheets can be made according to this methods.

Additional aspects of the invention are described in the following. BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1-4 are thermomechanical analysis (TMA) plots for various blends of an ethylene/styrene interpolymer (ESI) and a thermoplastic urethane polymer (TPU) in accordance with embodiments of the invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION Embodiments of the invention provide a blend of a substantially random olefin interpolymer and a urethane polymer. It is discovered that a compatibilizer is not necessary in the blend in accordance with embodiments of the invention. As such, the blend is substantially free of a compatibilizer. In some embodiments, the urethane polymer is blended or mixed with the olefin interpolymer in the form of fibers, and the fibers are dispersed in a matrix of the olefin interpolymer In other embodiments, a thermoplastic urethane polymer is blended with a compatible olefin interpolymer to form a relatively homogeneous mixture. Preferably, the substantially random olefin interpolymer is an α- olefin/ vinyl or vinylidene interpolymer, e.g., ethylene/styrene interpolymer. Various products can be made from the blends in accordance with embodiments of the invention.

In some embodiments, a thermoplastic urethane polymer (TPU) with a relatively low level of polar groups is blended with an olefin interpolymer, such as an ethylene/styrene interpolymer (ESI). For example, the TPU may have less than 30 polar groups per repeating unit. Sometimes, the TPU may have less than 20, less than 15, less than about 10, less than about 8, less than about 5, or less than about 3 polar groups per repeating units.

DEFINITIONS All references herein to elements or metals belonging to a certain Group refer to the

Periodic Table of the Elements published and copyrighted by CRC Press, Inc., 1989. Also any reference to the Group or Groups shall be to the Group or Groups as reflected in this Periodic Table of the Elements using the IUPAC system for numbering groups.

Any numerical values recited herein include all values from the lower value to the upper value in increments of one unit provided that there is a separation of at least 2 units between any lower value and any higher value. As an example, if it is stated that the amount of a component or a value of a process variable such as temperature, pressure, time and the like is, for example, from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, it is intended that values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. are expressly enumerated in this specification. For values which are less than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. The term "compatible" used herein means that two polymers, when mixed, form a relatively uniform mixture without substantial phase separation. Preferably, phase separation is not visible to naked eyes, i.e., no substantial presence of domains. One method to quantify the compatibility of two polymers is to use Hildbrand's solubility parameter which is a measure of the total forces holding the molecules of a solid or liquid together. Every polymer is characterized by a specific value of solubility parameter, although it is not always available. Polymers with similar solubility parameter values tend to be compatible. On the other hand, those with significantly different solubility parameters tend to be incompatible, although there are many exceptions to this behavior. Discussions of solubility parameter concepts are presented in (1) Encyclopedia of Polymer Science and Technology, Interscience, New York (1965), Vol. 3, pg. 833; (2) Encyclopedia of Chemical Technology, Interscience, New York (1971), Supp. Vol., pg. 889; and (3) Polymer Handbook, 3rd Ed., J. Brandup and E.H. Immergut (Eds.), (1989), John Wiley & Sons "Solubility Parameter Values," pp. VII-519, which are incorporated by referenced in their entirety herein. Generally, compatible polymers have a Hildbrand's solubility parameters which do not differ by more than about 100%. Preferably, the solubility parameters do not differ by more than about 70%), 50%, 30%, or 15%. More preferably, the solubility parameters do not differ by more than about 10%, 8%, or 5%.

The term "compatibilizer" as used herein refers to a compound added to the blend as a separate component to increase the compatibility between the substantially random olefin interpolymer and the urethane polymer. Examples of the such compatibilizer are disclosed in WO 01/36535. The term "substantially free of a compatibilizer" means that the blend in accordance with embodiments of the invention includes less than about 10% of a compabilizer by weight of the blend. In some embodiments, a compatibilizer is present in an amount less than about 8%, 5%, 2%, or 1% by weight of the blend. In other embodiments, no compatibilizer or less than about 0.5 wt.% of compatibilizer is present in the blend. The term "hydrocarbyl" as employed herein means any aliphatic, cycloaliphatic, aromatic, aryl substituted aliphatic, aryl substituted cycloaliphatic, aliphatic substituted aromatic, or aliphatic substituted cycloaliphatic groups.

The term "hydrocarbyloxy" means a hydrocarbyl group having an oxygen linkage between it and the carbon atom to which it is attached. The term "copolymer" as employed herein means a polymer wherein at least two different monomers are polymerized to form the copolymer.

The term "interpolymer" is used herein to indicate a polymer wherein at least two different monomers are polymerized to make the interpolymer. This includes copolymers, terpolymers, etc. As used herein, the term "extrusion" is used with reference to the process of forming continuous shapes by forcing a molten plastic material through a die, followed by cooling or chemical hardening. Immediately prior to extrusion through the die, the relatively high- viscosity polymeric material is fed into a rotating screw of variable pitch, which forces it through the die.

As used herein, the term "coextrusion" refers to the process of extruding two or more materials through a single die with two or more orifices arranged so that the extrudates merge and weld together into a laminar structure before chilling, i.e., quenching.

Coextrusion can be employed in film blowing, free film extrusion, and extrusion coating processes.

As used herein, the phrase "machine direction", herein abbreviated "MD", refers to a direction "along the length" of the film, i.e., in the direction of the film as the film is formed during extrusion and/or coating.

As used herein, the phrase "cross direction", herein abbreviated "CD", refers to a direction across the film, perpendicular to the machine or longitudinal direction.

The term "article" as used herein refers to fabricated composite items comprising the polymer blends or films disclosed herein. Articles include, but are not limited to, shoe soles, artificial leather, coated fabrics, engineered films, soft-touch sheets, soft-touch grips/handles, injection molded toys, wheels & casters, slush-molded auto parts, air- bladders, synthetic leather or suede products, disposable infant care and adult incontinence care items such as incontinence garments, training pants and diapers. The term also includes packages or films used for packaging, or wrapping goods such as meat, vegetables and commercial goods. Also included are combinations of trays, bowls or other containers covered sealed or protected by such films.

The term "structure" as used herein is defined as a polymer composition which has undergone a molding, film-, sheet-, fiber-, or foam-forming process.

The term "fabricated article" as used herein is defined as a polymer composition in the form of a finished article which may be formed directly from said polymer composition or be formed from an intermediate comprising one of the polymer blends or films described herein.

The term "film" as used herein is defined as having a thickness less than or equal to about 12 mils. The term "sheet" as used herein is defined as having a thickness greater than about

12 mils. The term "substantially random" (in the substantially random interpolymer comprising polymeric units derived from one or more α-olefin monomers with one or more vinyl aromatic monomers and/or aliphatic or cycloaliphatic vinyl or vinylidene monomers) as used herein means that the distribution of the monomers of said interpolymer can be described by the Bernoulli statistical model or by a first or second order Markovian statistical model, as described by J. C. Randall in POLYMER SEQUENCE DETERMINATION. Carbon- 13 NMR Method. Academic Press New York, 1977, pp. 71- 78. Preferably, substantially random interpolymers do not contain more than 15 percent of the total amount of vinyl aromatic monomer in blocks of vinyl aromatic monomer of more than 3 units. More preferably, the interpolymer is not characterized by a high degree of either isotacticity or syndiotacticity. This means that in the carbon NMR spectrum of the substantially random interpolymer the peak areas corresponding to the main chain methylene and methine carbons representing either meso diad sequences or racemic diad sequences should not exceed 75 percent of the total peak area of the main chain methylene and methine carbons.

SUBSTANTIALLY RANDOM INTERPOLYMERS

The olefin interpolymers used to in embodiments of the invention refers to the interpolymers prepared by polymerizing one or more α-olefins with one or more vinyl aromatic monomers and/or one or more aliphatic or cycloaliphatic vinyl or vinylidene monomers, and optionally other polymerizable monomers. In some embodiments, the substantially random olefin interpolymer comprises:

( 1 ) first polymeric units derived from:

(i) at least one vinyl aromatic monomer, or

(ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or

(iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, and

(2) second polymeric units derived from at least one C_2-20 -olefin; and optionally (3) third polymeric units derived from one or more ethylenically unsaturated polymerizable monomers other than those of (1) and (2). The first polymeric units may be present in the interpolymer in any amount, such as from about 0.5 mol.% to about 99.5 mol.%, from 5 mol.% to about 90 mol.%; from 10 mol.% to about 75 mol.%; from 1 mol.% to about 50 mol.%; from 10 mol.% to about 45 mol.%; or from 5 mol.% to about 35 mol.%. Preferably, the first polymeric units are present in an amount of about 50 mol.% or less. Similarly, the second polymer may be present in the interpolymer in the above ranges. In some embodiments, the second polymeric units are present in an amount of about 50 mol.% or higher. In other embodiments, the second polymeric units are present in an amount higher than the first polymeric units. The third polymeric units are optional and may be present up to about 50 mol.%, preferably up to about 40 mol.%, up to about 30 mol.%, up to about 20 mol.%, up to about 10 mol.%, or up to about 5 mol.%).

Suitable α-olefins include for example, α-olefins containing from 2 to about 20, preferably from 2 to about 12, more preferably from 2 to about 8 carbon atoms. Particularly suitable are ethylene, propylene, butene-1, 4-methyl-l-pentene, hexene-1 or octene-1 or ethylene in combination with one or more of propylene, butene-1, 4-methyl-l-pentene, hexene-1 or octene-1. These α-olefins do not contain an aromatic moiety.

Other optional polymerizable ethylenically unsaturated monomer(s) include strained ring olefins such as norbornene and C O alkyl or C_6-ιo aryl substituted norbornenes, with an exemplary interpolymer being ethylene/styrene/norbornene. Suitable vinyl aromatic monomers which can be employed to prepare the interpolymers include, for example, those represented by the following formula:

Ar I (CH₂)_n

R^l _ C = C(R2)₂ wherein R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl; each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl; the two R² groups can be the same or different groups. Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C_1-4- alkyl, and C_1-4-haloalkyl; and n has a value from zero to about 4, preferably from zero to 2, most preferably zero. Exemplary monovinyl aromatic monomers include styrene, vinyl toluene, α-methylstyrene, t-butyl styrene, chlorostyrene, including all isomers of these compounds, and the like. Particularly suitable such monomers include styrene and lower alkyl- or halogen-substituted derivatives thereof. Preferred monomers include styrene, α- methyl styrene, the lower alkyl- ( - C₄) or phenyl-ring substituted derivatives of styrene, such as ortho-, meta-, and para-methylstyrene, the ring halogenated styrenes, para-vinyl toluene or mixtures thereof, and the like. A more preferred aromatic monovinyl monomer is styrene.

By the term "aliphatic or cycloaliphatic vinyl or vinylidene compounds", it is meant addition polymerizable vinyl or vinylidene monomers corresponding to the formula:

A¹ R^l _ C = C(R2)₂ wherein A¹ is a sterically bulky, aliphatic or cycloaliphatic substituent of up to 20 carbons, R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl; alternatively R¹ and A¹ together may form a ring system. Each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to about 4 carbon atoms, preferably hydrogen or methyl; the two R² groups can be the same or different groups. Preferred aliphatic or cycloaliphatic vinyl or vinylidene compounds are monomers in which one of the carbon atoms bearing ethylenic unsaturation is tertiary or quaternary substituted. Examples of such substituents include cyclic aliphatic groups such as cyclohexyl, cyclohexenyl, cyclooctenyl, or ring alkyl or aryl substituted derivatives thereof, tert-butyl, norbornyl, and the like. Most preferred aliphatic or cycloaliphatic vinyl or vinylidene compounds are the various isomeric vinyl- ring substituted derivatives of cyclohexene and substituted cyclohexenes, and 5-ethylidene-2-norbornene. Especially suitable are 1-, 3-, and 4-vinylcyclohexene.

The substantially random interpolymers may be modified by typical grafting, hydrogenation, functionalizing, or other reactions well known to those skilled in the art. The polymers may be readily sulfonated or chlorinated to provide functionalized derivatives according to established techniques. The substantially random interpolymers may also be modified by various chain extending or cross-linking processes including, but not limited to peroxide-, silane-, sulfur-, radiation-, or azide-based cure systems. A full description of the various cross-linking technologies is described in U.S. Patents No. 5,869,591 and No. 5,977,271, both of which are herein incoφorated by reference in their entirety.

Dual cure systems, which use a combination of heat, moisture cure, and radiation steps, may be effectively employed. Dual cure systems are disclosed in U.S. Patents No. 5,911,940 and No. 6,124,370, which are incorporated herein by reference in their entirety. For instance, it may be desirable to employ peroxide crosslinking agents in conjunction with silane crosslinking agents, peroxide crosslinking agents in conjunction with radiation, sulfur-containing crosslinking agents in conjunction with silane crosslinking agents, etc.

The substantially random interpolymers may also be modified by various other cross-linking processes including, but not limited to the incorporation of a diene component as a termonomer in its preparation and subsequent cross linking by the aforementioned methods and further methods including vulcanization via the vinyl group using sulfur for example as the cross linking agent.

The substantially random interpolymers can be prepared as described in EP-A- 0,416,815 by James C. Stevens et al. and US Patent No. 5,703,187 by Francis J. Timmers, both of which are incorporated herein by reference in their entirety. Such a method of preparation of the substantially random interpolymers includes polymerizing a mixture of polymerizable monomers in the presence of one or more metallocene or constrained geometry catalysts in combination with various cocatalysts. Preferred operating conditions for such polymerization reactions are pressures from atmospheric up to 3000 atmospheres and temperatures from -30°C to 200°C. Polymerizations and unreacted monomer removal at temperatures above the autopolymerization temperature of the respective monomers may result in formation of some amounts of homopolymer polymerization products resulting from free radical polymerization.

Examples of suitable catalysts and methods for preparing the substantially random interpolymers are disclosed in U.S. Application Serial No. 702,475, filed May 20, 1991 (EP-A-514,828); as well as U.S. Patents: 5,055,438; 5,057,475; 5,096,867; 5,064,802; 5,132,380; 5,189,192; 5,321,106; 5,347,024; 5,350,723; 5,374,696; 5,399,635; 5,470,993; 5,703,187; and 5,721,185 all of which patents and applications are incorporated herein by reference.

The substantially random α-olefin vinyl aromatic interpolymers can also be prepared by the methods described in JP 07/278230 employing compounds shown by the general formula:

C_P1 _R1

where Cp¹ and Cp² are cyclopentadienyl groups, indenyl groups, fluorenyl groups, or substituents of these, independently of each other; R and R are hydrogen atoms, halogen atoms, hydrocarbon groups with carbon numbers of 1-12, alkoxyl groups, or aryloxyl groups, independently of each other; M is a group IV metal, preferably Zr or Hf, most preferably Zr; and R³ is an alkylene group or silanediyl group used to cross-link Cp¹ and Cp²).

The substantially random α-olefin/vinyl aromatic interpolymers can also be prepared by the methods described by John G. Bradfute et al. (W. R. Grace & Co.) in WO 95/32095; by R. B. Pannell (Exxon Chemical Patents, Inc.) in WO 94/00500; and in Plastics Technology, p. 25 (September 1992), all of which are incorporated herein by reference in their entirety.

Also suitable are the substantially random interpolymers which comprise at least one α-olefin/vinyl aromatic/vinyl aromatic/α-olefin tetrad disclosed in U. S. Application No. 08/708,809 filed September 4, 1996 and WO 98/09999 both by Francis J. Timmers et al. These interpolymers contain additional signals in their carbon- 13 NMR spectra with intensities greater than three times the peak to peak noise. These signals appear in the chemical shift range 43.70 - 44.25 ppm and 38.0 - 38.5 ppm. Specifically, major peaks are observed at 44.1, 43.9, and 38.2 ppm. A proton test NMR experiment indicates that the signals in the chemical shift region 43.70 - 44.25 ppm are methine carbons and the signals in the region 38.0 - 38.5 ppm are methylene carbons.

It is believed that these new signals are due to sequences involving two head-to-tail vinyl aromatic monomer insertions preceded and followed by at least one α-olefin insertion, e.g. an ethylene/styrene/styrene/ethylene tetrad wherein the styrene monomer insertions of said tetrads occur exclusively in a 1,2 (head to tail) manner. It is understood by one skilled in the art that for such tetrads involving a vinyl aromatic monomer other than styrene and an α-olefin other than ethylene that the ethylene/vinyl aromatic monomer/vinyl aromatic monomer/ethylene tetrad will give rise to similar carbon ¹³NMR peaks but with slightly different chemical shifts.

These interpolymers can be prepared by conducting the polymerization at temperatures of from about -30°C to about 250°C in the presence of such catalysts as those represented by the formula

/ \

(ER₂)_m MR₂

\ /

^CP wherein: each Cp is independently, each occurrence, a substituted cyclopentadienyl group π- bound to M; E is C or Si; M is a group IV metal, preferably Zr or Hf, most preferably Zr; each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to about 30 preferably from 1 to about 20 more preferably from 1 to about 10 carbon or silicon atoms; each R' is independently, each occurrence, H, halo, hydrocarbyl, hyrocarbyloxy, silahydrocarbyl, hydrocarbylsilyl containing up to about 30 preferably from 1 to about 20 more preferably from 1 to about 10 carbon or silicon atoms or two R groups together can be a Cι_-10 hydrocarbyl substituted 1,3 -butadiene; m is 1 or 2; and optionally, but preferably in the presence of an activating cocatalyst. Particularly, suitable substituted cyclopentadienyl groups include those illustrated by the formula:

wherein each R is independently, each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to about 30 preferably from 1 to about 20 more preferably from 1 to about 10 carbon or silicon atoms or two R groups together form a divalent derivative of such group. Preferably, R independently each occurrence is (including where appropriate all isomers) hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenyl or silyl or (where appropriate) two such R groups are linked together forming a fused ring system such as indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, or octahydrofluorenyl.

Particularly preferred catalysts include, for example, racemic-(dimethylsilanediyl)- bis-(2-methyl-4-phenylindenyl))zirconium dichloride, racemic-(dimethylsilanediyl)-bis-(2- methyl-4-phenylindenyl))zirconium 1 ,4-diphenyl- 1 ,3 -butadiene, racemic-(dimethyl silanediyl)-bis-(2-methyl-4-phenylindenyl))zirconium di-Cl-4 alkyl, racemic-(dimethyl silanediyl)-bis-(2-methyl-4-phenylindenyl)) zirconium di-Cl-4 alkoxide, or any combination thereof and the like. It is also possible to use the following titanium-based constrained geometry catalysts,

[N-(l,l-dimethylethyl)-l,l-dimethyl-l-[(l,2,3,4,5-η)-l,5,6,7-tetrahydro-s-indacen-l-yl] silanaminato(2-)-N]titanium dimethyl; (l-indenyl)(tert-butylamido) dimethyl- silane titanium dimethyl; ((3-tert-butyl)(l,2,3,4,5-η)-l-indenyl)(tert-butylamido) dimethylsilane titanium dimethyl; and ((3-iso-propyl)(l,2,3,4,5-η)-l-indenyl)(tert-butyl amido)dimethyl silane titanium dimethyl, or any combination thereof and the like.

Further preparative methods for the interpolymers used in embodiments of the invnention have been described in the literature. Longo and Grassi (Makromol. Chem.. Volume 191, pages 2387 to 2396 [1990]) and D'Anniello et al. (Journal of Applied Polymer Science, Volume 58, pages 1701-1706 [1995]) reported the use of a catalytic system based on methylalumoxane (MAO) and cyclopentadienyltitanium trichloride (CpTiCl₃) to prepare an ethylene-styrene copolymer. Xu and Lin (Polymer Preprints. Am. Chem. Soc. Div. Polym. Chem.) Volume 35, pages 686,687 [1994]) have reported copolymerization using a MgCl /TiCl₄/NdCl₃/ Al(iBu)₃ catalyst to give random copolymers of styrene and propylene. Lu et al (Journal of Applied Polymer Science, Volume 53, pages 1453 to 1460 [1994]) have described the copolymerization of ethylene and styrene using a TiCL</NdCl₃/ MgCl₂ /Al(Et)₃ catalyst. Sernetz and Mulhaupt, (Macromol. Chem. Phvs.. v. 197, pp. 1071-1083, 1997) have described the influence of polymerization conditions on the copolymerization of styrene with ethylene using Me₂Si(Me Cp)(N-tert-butyl)TiCl₂/methylaluminoxane Ziegler- Natta catalysts. Copolymers of ethylene and styrene produced by bridged metallocene catalysts have been described by Arai, Toshiaki and Suzuki (Polymer Preprints, Am. Chem. Soc, Div. Polvm. Chem.) Volume 38, pages 349, 350 [1997]) and in United States patent number 5,652,315, issued to Mitsui Toatsu Chemicals, Inc. The manufacture of α- olefin/vinyl aromatic monomer interpolymers such as propylene/styrene and butene/styrene are described in United States patent number 5,244,996, issued to Mitsui Petrochemical Industries Ltd or United States patent number 5,652,315 also issued to Mitsui Petrochemical Industries Ltd or as disclosed in DE 197 11 339 Al to Denki KAGAKU Kogyo KK. All the above methods disclosed for preparing the interpolymer component are incoφorated herein by reference.

While preparing the substantially random inteφolymer, an amount of atactic vinyl aromatic homopolymer may be formed due to homopolymerization of the vinyl aromatic monomer at elevated temperatures. The presence of vinyl aromatic homopolymer is in general not detrimental and can be tolerated. The vinyl aromatic homopolymer may be separated from the inteφolymer, if desired, by extraction techniques such as selective precipitation from solution with a non solvent for either the inteφolymer or the vinyl aromatic homopolymer. It is preferred that no more than 30 weight percent, preferably less than 20 weight percent based on the total weight of the inteφolymers of atactic vinyl aromatic homopolymer is present.

URETHANE POLYMERS Suitable urethane polymers (i.e., polyurethane) include any synthetic polymer whose backbone contains the -NH-COO- group. Some polyurethanes are thermosetting resins and others are thermoplastic resins. Polyurethanes are generally prepared by combining and reacting (i) at least one polyol intermediate, such as a hydroxyl terminated polyester, a hydroxyl terminated polyether, a hydroxyl terminated polycarbonate, a hydroxyl terminated polycaprolactone, or mixtures thereof, with (ii) at least one polyisocyanate and (iii) optionally at least one chain extender.

One class of suitable commercial polyurethanes include, for example, the ESTANE™ series of polyurethanes available from the B.F. Goodrich Company (Charlotte, NC), such as ESTANE™ 58157, 58142, 58212, 58215, 58887, and 58144. Another class of suitable commercial polyurethanes include the PELLETHANE™ series available from The Dow Chemical Company (Midland, MI). For example, they include, but are not limited to, ether- ether based PELLETHANE™ 2101-85A, polycaprolactone-based PELLETHANE™ 2102 (55D, 65D, 75A, 80A, 85A, 90A, 90AE, and 90AR), polyester adipate-based PELLETHANE™ 2355 (55DE, 75A, 80AE, 80AIM, 85ABR, 85AIM, 95AE, 95AEF, and 95AEL), polyether-based PELLETHANE™ 2103 (55D, 65D, 70A, 80AE, 80AEF, 80AEN, 85AE, 90A, 90AE, 90AEFH, 90AEL, 90AEN, and 90AENH), polyether-based PELLETHANE™ 2363 (55DE, 65D, 75D, 80A, 80AE, 90A, and 90AE), and ether-ether/ether-ester hybrids PELLETHANE™ 2104 (45D and 65D). Methods of making polyurethanes are disclosed, for example, in U.S. Patents No. 2,284,637; 2,284,896; 2,511,544; 2,873,266; 4,080,314; 4,098,772; 4,202,957; 4,306,052; 4,420,602; RE 31,671; 4,376,834, and 5,627,254, all of which are incoφorated by reference in their entirety. Another class of suitable polyurethanes is polycaprolactone-based or polyester-based aliphatic thermoplastic polyurethanes available from Huntsman Coφoration under the trade name of KRYSTALGRAN, such as PN03-214, PN3429-219, and PN343-200.

In some embodiments, thermoplastic urethane polymers (TPUs) are used. Any thermoplastic polyurethanes may be used. They include, but are not limited to, those prepared from a diisocyanate, a polyester, polycaprolactone or polyether and a chain extender. Preferably, such thermoplastic polyurethanes are substantially linear and maintain thermoplastic processing characteristics.

A suitable group of polyether-based polyurethanes used in the polymer blend composition are the reaction products of: (i) 4,4'-methylene bis(phenyl isocyanate) or 4,4' diphenyl methane diisocyanate (MDI), (ii) a polyether polyol (such as a poly (oxy-1,2 propylene) glycol or a polyoxytetramethylene glycol) having a number average molecular weight within the range of about 100 to about 4000 or about 600 to about 3000 (preferably from about 1000 to about 2500) and (iii) chain extending agent, such as diol extenders selected from aliphatic straight chain diols having from 2 to about 6 carbon atoms, bis(2- hydroxy-ethyl) ether of hydroquinone, bis(2-hydroxy-ethyl) ether of resorcinol, or mixtures of any two or more of such diol extenders and/or other difunctional chain extending agents containing 2 active hydrogen-containing groups which are reactive with isocyanate groups.

Suitable chain extending agents for use herein may include any difunctional compounds containing two active hydrogen-containing groups which are reactive with isocyanate groups. Examples of such suitable chain extending agents thus include diols including ethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol, butenediol, butynediol, xylylene glycols, amylene glycols, 1,4-phenylene-bis-β-hydroxyethyl ether, 1,3- phenylene-bis-β-hydroxy ethyl ether, bis-(hydroxy-methyl-cyclohexane), hexanediol, thiodiglycol and the like; diamines including ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, cyclohexalene diamine, phenylene diamine, tolylene diamine, xylylene diamine, 3,3'-dichlorobenzidine, 3,3'-dinitrobenzidine and the like; alkanol amines such as ethanol amine, aminopropyl alcohol, 2,2-dimethyl propanol amine, 3-aminocyclohexyl alcohol, paminobenzyl alcohol and the like. If desirable, a small amount of polyfunctional material may be utilized. Any suitable polyfunctional compound may be used for this puφose such as glycerine, trimethylolpropane, hexanetriol, pentaerythritol and the like.

As used herein, the term "aliphatic straight chain diols having from 2 to about 6 carbon atoms" means diols of the formula HO(CH₂)_nOH wherein n is 2 to about 6 and there is no branching in the aliphatic chain separating the OH groups. The term includes, but is not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol and 1,6- hexanediol. Preferred diol extenders for use herein include 1,4-butanediol, 1,6-hexanediol and the bis(2-hydroxy-ethyl) ether of hydroquinone; an especially preferred diol extender being 1,4-butanediol.

Other diisocyanates which may be used in place of or in combination with the species mentioned above include, but are not limited to, ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, cyclopentylene-1,3- diisocyanate, cyclohexylene-l,4-diisocyanate, 2,6-tolylene diisocyanate, 2,2- diphenylpropane-4,4'-diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, 1,4-naphtylene diisocyanate, 1,5-naphthylene diisocyanate, diphenyl- 4,4'-diisocyanate, azobenzene-4,4'diisocyanate, diphenyl sulfone-4,4'diisocyanate, dichlorohexamethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, l-chlorobenzene-l,4-diisocyanate, furfurylidene diisocyanate and the like.

The polyether polyol and chain extending agent are typically used in the polyurethane reaction medium in a ratio of about 0.5 to about 2.5 equivalents (e.g., mole equivalents) of the chain extender per equivalent of the polyol. Preferably, the equivalents ratio is from about 1 to about 2. Most preferably the ratio is from about 1.2 to about 1.6 equivalents of extender per equivalent of the polyol when said polyol has a molecular weight of about 2000 or in the range from about 100 to about 4000, and especially when the extender is an aliphatic straight chain diol. When the aforementioned hydroquinone or resorcinol extender are used, the equivalents ratio may be lower than the above-mentioned preferred ranges, for example, as low as about 0.5 equivalents of the extender per equivalent of the polyol. In preparing the foregoing polyether-based polyurethanes, the polyether polyol and the chain extender and the diisocyanate are typically used in relative proportions to each other such that the overall ratio of isocyanate equivalents or groups to total hydroxyl equivalents or groups or other active hydrogen-containing groups (i.e., polyol plus extender) is within the range of about 1 : 1 to about 1.08: 1.0 and preferably is within the range of about 1.02:1.0 to about 1.07:1.0. The most preferred ratio of isocyanate (NCO) groups to total hydroxyl (OH) groups (or combined hydroxyl plus other active hydrogen groups) is within the range of from about 1.03:1.0 to about 1.06:1.0.

The term equivalent(s) as used with respect to the polyurethane preparation herein is based on the hydroxyl (or other active hydrogen) groups and the isocyanate groups within the reactants.

Suitable techniques for the preparation of the aforementioned polyether-based thermoplastic polyurethanes are known in the art and are discussed, for example, within the teachings in Columns 4-6 of U.S. Pat. No. 4,665,126 to Kusumgar et al., said teachings being hereby incoφorated herein by reference thereto.

In some embodiments, the polyether-based thermoplastic polyurethanes employed are characterized by a ClashBerg modulus (T_f) which is less than about 10 °C. The T_g (glass transition temperature) of the polyurethanes is essentially the same value. The polyether- based polyurethanes may have, for example, a Shore A Hardness of 95A or less, and a weight average molecular weight in excess of 100,000.

The thermoplastic polyurethane can be a rigid thermoplastic polyurethane (ETPU or rigid TPU). ETPUs have a glass transition temperature of greater than 50 °C and contains less than 25 weight percent of units of a high molecular weight diol (this is, a diol having a molecular weight of not less than 500). Preferably, the units of the high molecular weight diol constitute no more than 10 weight percent of the ETPU, more preferably no more than 5 weight percent of the ETPU, and more preferably no more than 1 weight percent of the ETPU. Preferred ETPUs may also contain zero units of high molecular weight diol. Examples of commercially available ETPUs include ISOPLAST™ resins (a trademark of The Dow Chemical Company), the preparation of which is disclosed, for example, in U.S. Patents No. 4,376,834 and No. 5,627,254, all of which are incoφorated by reference herein in their entirety. Such ETPUs contains structural units of a chain extender, such as 1,6- hexanediol or a blend of 1,4-butanediol and a polyethylene glycol. Another suitable group of thermoplastic polyester-based polyurethanes for use in embodiments of the invention is the reaction products of: (i) 4,4'methylene bis(phenyl isocyanate); (ii) a polyester of adipic acid and a glycol having at least one primary hydroxyl group; and (iii) a difunctional chain extender of the sort described above having 2 active hydrogen-containing groups which are reactive with isocyanate groups.

In preparing the polyester precursor of this group of polyurethanes the adipic acid is condensed with a suitable glycol or mixture of glycols which have at least one primary hydroxyl group. The condensation is stopped when an acid number of from about 0.5 to about 2.0 is reached. The water formed during the reaction is removed simultaneously therewith or subsequently thereto such that the final water content is from about 0.01 to about 0.02 percent preferably from about 0.01 to 0.05 percent.

Any suitable glycol may be used in reaction with the adipic acid such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, bis-(hydroxymethylcyclohexane), 1,4- butanediol, diethylene glycol, 2,2-dimethyl propylene glycol, 1,3-propylene glycol and the like. In addition to the glycols, a small amount of trihydric alcohol up to about percent may be used along with the glycols such as trimethylolpropane, glycerine, hexanetriol and the like. The resulting hydroxyl polyester has a molecular weight of at least about 600, a hydroxyl number of about 25 to about 190 and preferably between about 40 and about 60, and an acid number of between about 0.5 and about 2 and a water content of 0.01 to about 0.2 percent.

Any suitable chain extending agent including those described above for the polyether-based thermoplastic polyurethanes) having active hydrogen containing groups reactive with isocyanate groups may be used in preparing the subject polyester-based materials. Examples of such extenders thus include diols such as ethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol, butenediol, butynediol, xylylene glycols, amylene glycols, 1,4-phenylene-bis-β-hydroxyethyl ether, 1,3-phenylene-bis-β-hydroxy ethyl ether, bis-(hydroxy-methyl-cyclohexane), hexanediol, thiodiglycol and the like. Moreover, polyether polyols may also be employed as the chain extending agent (or as a portion thereof) with the result being a copolyester/polyether based thermoplastic polyurethane which is also suitable for use in embodiments of the invnention.

Although thermoplastic polyurethanes based upon adipate polyesters are generally preferred for use herein, other polyester-based thermoplastic polyurethanes can also be suitably employed within embodiments of the invnention such as those in which there is employed (in place of the adipic acid) succinic acid, suberic acid, sebacic acid, oxalic acid, methyl adipic acid, glutaric acid, pimelic acid, azelaic acid, phthalic acid, terephthalic acid, isophthalic acid and the like as well as those prepared using hydroxycarboxylic acids, lactones, and cyclic carbonates such as ε-caprolactone and 3-hydroxy-butyric acid in place of the adipic acid component. Similarly polyester-based thermoplastic polyurethanes prepared using the above-described alternative diisocyanates in place of 4,4'-methylene bis (phenyl isocyanate) can also be suitably employed.

The aforementioned types of polyester-based thermoplastic polyurethanes can be prepared by the methods disclosed within Column 7 of U.S. Pat. No. 4,665,126 and is incoφorated herein by reference. Other thermoplastic urethane polymers may also be used.

For example, the following U.S. patents disclose various TPUs which may be used in embodiments of the invention with or without modifications: 3,987,012; 4,035,440

4,124,572; 4,179,479; 4,192,928; 4,202,957; 4,238,574 4,239,879; 4,245,081; 4,367,302 4,400,498; 4,413,101; 4,442,281; 4,748,195; 4,877,856 4,880,847; 5,066,762; 5,070,173

5,096,993; 5,130,384; 5,200,491; 5,216,062; 5,274,023 5,281,677; 5,376,723; 5,436,399

5,494,990; 5,688,863; 5,688,890; 5,695,884; 5,739,250; 5,785,916; 5,846,474; 6,258,310 and 6,291,587, all of which are incoφorated by reference herein in their entirety.

ADDITIVES Additives such as antioxidants (e.g., hindered phenols such as Irganox® 1010, and phosphites, e.g., IRGAFOS™ 168, (both are registered trademarks of, and supplied by Ciba-

Geigy Coφoration, NY), UN. stabilizers (including TIΝUVIΝ™ 328 and CHIMASSORB™

944, both are registered trademarks of, and supplied by Ciba-Geigy Coφoration, ΝY), cling additives (e.g., polyisobutylene), slip agents (such as erucamide and/or stearamide), antiblock additives, colorants, pigments, and the like can also be included in the inteφolymers and/or blends employed to prepare the blends or films, to the extent that they do not adversely affect the physical characteristics of the blends or films. Processing aids, which are also referred to herein as plasticizers, are optionally provided to reduce the viscosity of a composition, and include the phthalates, such as dioctyl phthalate and diisobutyl phthalate, natural oils such as lanolin, and paraffin, naphthenic and aromatic oils obtained from petroleum refining, and liquid resins from rosin or petroleum feedstocks. Suitable modifiers which can be employed herein as the plasticizer include at least one plasticizer selected from the group consisting of phthalate esters, trimellitate esters, benzoates, adipate esters, epoxy compounds, phosphate esters (triaryl, trialkyl, mixed alkyl aryl phosphates), glutarates and oils. Particularly suitable phthalate esters include, for example, dialkyl C₄-Cι₈ phthalate esters , such as diethyl, dibutyl phthalate, diisobutyl phthalate, butyl 2-ethylhexyl phthalate, dioctyl phthalate, diisooctyl phthalate, dinonyl phthalate, diisononyl phthalate, didecyl phthalate, diisodecyl phthalate, diundecyl phthalate, mixed aliphatic esters , such as heptyl nonyl phthalate, di(n-hexyl, n-octyl, n-decyl) phthalate (P610), di(n-octyl, n-decyl) phthalate (P810), and aromatic phthalate esters , such as diphenyl phthalate ester, or mixed aliphatic-aromatic esters , such as benzyl butyl phthalate or any combination thereof and the like.

Exemplary classes of oils useful as processing aids include white mineral oil (such as Kaydol™ oil (available from Witco), and Shellflex™ 371 naphthenic oil (available from Shell Oil Company). Another suitable oil is Tuflo™ oil (available from Lyondell).

Antifogging or antistatic agents can be added to the films and sheets to increase surface conductivity and prevention of water droplet formation and attraction of dust and dirt on the film surface. These antifogging agents include, but are not limited to, glycerol mono-stearate, glycerol mono-oleate, lauric diphthalamides, ethoxylated amines, ethoxylated esters, and other additives known in the industry.

Tackifiers can also be added to the polymer compositions used to prepare films or sheets in order to alter the T_g and thus extend the available application temperature window of the film. Examples of the various classes of tackifiers include, but are not limited to, aliphatic resins, polyteφene resins, hydrogenated resins, mixed aliphatic-aromatic resins, styrene/α-methylene styrene resins, pure monomer hydrocarbon resin, hydrogenated pure monomer hydrocarbon resin, modified styrene copolymers, pure aromatic monomer copolymers, and hydrogenated aliphatic hydrocarbon resins. Exemplary aliphatic resins include those available under the trade designations Escorez™, Piccotac™, Mercures™, Wingtack™, Hi-Rez™, Quintone™, Tackirol™, etc. Exemplary polyteφene resins include those available under the trade designations Nirez™, Piccolyte™, Wingtack™, Zonarez™, etc. Exemplary hydrogenated resins include those available under the trade designations Escorez™, Arkon™, Clearon™, etc. Exemplary mixed aliphatic-aromatic resins include those available under the trade designations Escorez™, Regalite™, Hercures™, AR™, Imprez™, Norsolene™ M, Marukarez™, Arkon™ M, Quintone™, Wingtack™, etc. One particularly preferred class of tackifiers includes the styrene/α-methylene styrene tackifiers available from Hercules. Particularly suitable classes of tackifiers include Wingtack™ 86 and Hercotac™ 1149, Eastman H-130, and styrene/α-methyl styrene tackifiers.

Also included as a potential component of the polymer compositions are various organic and inorganic fillers, the identity of which depends upon the type of application for which the film is to be utilized. Representative examples of such fillers include organic and inorganic fibers, such as those made from asbestos, boron, graphite, ceramic, glass, metals (such as stainless steel) or polymers (such as aramid fibers) talc, carbon black, carbon fibers, calcium carbonate, alumina trihydrate, glass fibers, marble dust, cement dust, clay, feldspar, silica or glass, fumed silica, alumina, magnesium oxide, magnesium hydroxide, antimony oxide, zinc oxide, barium sulfate, aluminum silicate, calcium silicate, titanium dioxide, titanates, aluminum nitride, B₂O₃, nickel powder or chalk.

Other representative organic or inorganic, fiber or mineral, fillers include carbonates such as barium, calcium or magnesium carbonate; fluorides such as calcium or sodium aluminum fluoride; hydroxides such as aluminum hydroxide; metals such as aluminum, bronze, lead or zinc; oxides such as aluminum, antimony, magnesium or zinc oxide, or silicon or titanium dioxide; silicates such as asbestos, mica, clay (kaolin or calcined kaolin), calcium silicate, feldspar, glass (ground or flaked glass or hollow glass spheres or microspheres or beads, whiskers or filaments), nepheline, perlite, pyrophyllite, talc or wollastonite; sulfates such as barium or calcium sulfate; metal sulfides; cellulose, in forms such as wood or shell flour; calcium terephthalate; and liquid crystals. Mixtures of more than one such filler may be used as well.

These additives are employed in functionally equivalent amounts known to those skilled in the art. For example, the amount of antioxidant employed is that amount which prevents the polymer or polymer blend from undergoing oxidation at the temperatures and environment employed during storage and ultimate use of the polymers. Such amount of antioxidants is usually in the range of from 0.01 to 10, preferably from 0.05 to 5, more preferably from 0.1 to 2 percent by weight based upon the weight of the polymer or polymer blend. Similarly, the amounts of any of the other enumerated additives are the functionally equivalent amounts such as the amount to render the polymer or polymer blend antiblocking, to produce the desired result, to provide the desired color from the colorant or pigment. Such additives can suitably be employed in the range of from 0.05 to 50, preferably from 0.1 to 35, more preferably from 0.2 to 20 percent by weight based upon the weight of the polymer or polymer blend. When a processing aid is employed, it may be present in the composition of the invention in an amount of at least 5 percent. The processing aid may typically be present in an amount of no more than 60, preferably no more than 30, and most preferably no more than 20 weight percent.

PREPARATION OF BLENDS The blended polymer compositions can be prepared by any method, including dry blending the individual components and subsequently melt mixing or melt compounding in a Haake torque rheometer or by dry blending without melt blending followed by part fabrication, either directly in an extruder or mill used to make the finished article (e.g., automotive part), or by pre-melt mixing in a separate extruder or mill (e.g., a Banbury mixer), or by solution blending, or by compression molding, or by calendering, or by slush molding as described in U.S. Patent No. 5,077,339, which is incoφorated by reference herein by its entirety. Any amount (i.e., from about 0.05% to about 99.95%) of an olefin inteφolymer may be blended with a urethane polymer. In some embodiments, the olefin inteφolymer is present by at least about 10% by weight of the blend, preferably from about 20 to about 80 wt.% or from about 40 to about 60 wt.%. The urethane polymer may be present from about 10 to about 80% by weight of the blend, preferably from about 20 to about 70 wt.% or from about 30 to about 60 wt.%. In some embodiments, compatible polymers are used to make a blend. In other embodiments, polyurethane in the form of fibers or powders is dispersed in a matrix of the olefin inteφolymer.

The substantially random olefin inteφolymer may comprise from about 0.5 mole percent to about 99 mole percent of a vinyl aromatic monomer and/or aliphatic or cycloaliphatic vinyl or vinylidene monomer. Conversely, it may comprise about 0.5 mole percent to about 99 mole percent of one or more aliphatic α-olefms. Preferably, the substantially random inteφolymers contain from about 10 to about 40 preferably from about 13 to about 33, more preferably from about 15 to about 29 mole percent of at least one vinyl aromatic monomer and/or aliphatic or cycloaliphatic vinyl or vinylidene monomer and from about 60 to about 90, preferably from about 67 to about 87, more preferably from about 71 to about 85 mole percent of at least one aliphatic α-olefin having from 2 to about 20 carbon atoms. The number average molecular weight (M_n) of the substantially random inteφolymer is generally greater than about 10,000, preferably from about 20,000 to about 500,000, more preferably from about 30,000 to about 300,000. The melt index (I₂) of the substantially random inteφolymer is about 0.1 to about 1,000, preferably of from about 0.5 to about 200, more preferably of from about 0.5 to about 100 g/ 10 min.

The molecular weight distribution (M_w/M_n) of the substantially random inteφolymer is from about 1.5 to about 20, preferably of from about 1.8 to about 10, more preferably of from about 2 to about 5. The density of the substantially random inteφolymer used to prepare the films is greater than about 0.930, preferably from about 0.930 to about 1.045, more preferably of from about 0.930 to about 1.040, most preferably of from about 0.930 to about 1.030 g/cm³.

A preferred olefin inteφolymer for use in embodiments of the invention is ethylene styrene inteφolymer (ESI) under the trademark of INDEX™ from The Dow Chemical Company. The ESI polymer can be made according to the processes disclosed in U.S. Patent No. 5,703,187, which is incoφorated by reference herein in its entirety. Two series of ESI are available from The Dow Chemical Company: S-Series (which contain more than 50 wt.% of styrene) and E-Series (which contain up to 50 wt.% of styrene). Both series may be used in embodiments of the invention. Examples of suitable ESI polymers from The Dow Chemical Company includes those designated herein as ESI #1, ESI #2, ESI #3, and ESI #4, whose physical properties are listed in Tables 1-4.

Table 1 Properties of ESI #1

Table 2 Properties of ESI #2

Table 3 Properties of ESI #3

Table 4 Properties of ESI #4

One suitable class of thermoplastic urethane polymers is available from The Dow Chemical Company under the trade name PELLETHANE™. Examples of such polymers are designated here as TPU #1, TPU #2, TPU #3, TPU #4, TPU #5, and TPU #6, whose physical properties are listed in Tables 5-8.

Table 5 Properties of TPU #1

Table 6 Properties of TPU #2

Table 7 Properties of TPU #3

Table 8 Properties of TPU #4

Table 9 Properties of TPU #5

Table 10 Properties of TPU #6

PREPARATION OF FILMS Films of the polymer blend compositions can be made by any fabrication techniques, e.g. simple bubble extrusion, simple cast/sheet extrusion, coextrusion, lamination, calendering, etc. Conventional simple bubble extrusion processes (also known as hot blown film processes) are described, for example, in The Encyclopedia of Chemical Technology. Kirk-Othmer, Third Edition, John Wiley & Sons, New York, 1981, Vol 16, pp. 416-417 and Vol. 18, pp. 191-192, the disclosures of which are incorporated herein by reference.

Injection molding, thermoforming, extrusion coating, profile extrusion, and sheet extrusion processes are described, for example, in Plastics Materials and Processes, Seymour S. Schwartz and Sidney H. Goodman, Nan Nostrand Reinhold Company, New York, 1982, pp. 527-563, pp. 632-647, and pp. 596-602. The strips, tapes and ribbons can be prepared by the primary extrusion process itself or by post-extrusion slitting, cutting or stamping techniques. Profile extrusion is an example of a primary extrusion process that is particularly suited to the preparation of tapes, bands, ribbons and the like. The films can also be rendered pervious or "breathable" by any method, such as apperturing, slitting, microperforating, mixing with fibers or foams, or the like and combinations thereof. Examples of such methods include, USP 3,156,242 by Crowe, Jr., USP 3,881,489 by Hartwell, USP 3,989,867 by Sisson and USP 5,085,654 by Buell, the disclosures of all of which are incorporate herein by reference. The film structures can be monolayer film or a multilayer film. In those embodiments in which the film structure is multilayer, it can be of any structure, e.g. 2-ply, 3-ply, 4-ply, 5-ply, 6-ply, 7-ply, etc. The structure generally have an odd number of layers, and the film layer(s) comprising a blend of a substantially random interpolymer and a urethane polymer can be one or both outer layers and/or one or more core layers. Those layer(s) constructed from polymer other than the blend or mixture can comprise any suitable material generally compatible with a film constructed from the blend or mixture, e.g. one or more conventional LDPE, LLDPE, ULDPE, EVA, EAA, and the like. Additives such as those described above with respect to monolayer films can also be used in these multilayer films, and these additives can be incorporated into any of the film layers as desired, e.g. tackifiers and slip agents into one or both outer layers, fillers in one or more core layers, etc. Other multilayer film manufacturing techniques for food packaging applications are described in Packaging Foods With Plastics by Wilmer A. Jenkins and James P. Harrington (1991), pp. 19-27, and in "Coextrusion Basics" by Thomas I. Butler, Film Extrusion Manual: Process. Materials, Properties, pp. 31-80 (published by TAPPI Press (1992)) the disclosures of which are incorporated herein by reference.

Other desirable properties of the plastic films include, depending on the nature of the other film layers in the structure, ease of fabrication and good oxygen permeability (particularly with respect to films made from such copolymers as ENA and EAA), oxygen impermeability (particularly with respect to films containing an oxygen barrier such as SARAΝ or ethylene vinyl alcohol), dart impact, puncture resistance, tensile strength, low modulus, tear resistance, shrinkability, high clarity and a low affect on the taste and odor properties of the packaged food.

The films are useful for stretch overwrap packaging various fresh foods, e.g. retail- cut red meats, fish, poultry, vegetables, fruits, cheeses, and other food products destined for retail display. These films are preferably prepared as nonshrink films (e.g., without biaxial orientation induced by double bubble processing), with good stretch, elastic recovery and hot tack characteristics, and can be made available to wholesalers and retailers in any conventional form, e.g. stock rolls, and used on all conventional equipment.

Other films can be used as shrink, skin and vacuum form packages for foods. The films comprising the shrink packages are typically biaxially oriented, exhibit low shrink tension, are of a density greater than about 0.89 g/cm-*, and are typically about 0.6 to about 2 mil in thickness. The film structures used in vacuum skin packaging can be multilayered, are typically about 5 to about 12 mil in thickness.

The films or sheets can also be formed by extrusion processes and, preferably, by coextrusion methods. Following coextrusion the film or sheet is cooled to a solid state by, for example, cascading water or chilled air quenching. For some structures a precursor film or sheet layer or layers may be formed by extrusion with additional layers thereafter being extrusion coated thereon to form multilayer films or sheets. Two multilayer tubes may also be formed with one of the tubes thereafter being coated or laminated onto the other. Other forms of sheets may also be fabricated.

PREPARATION OF WATER-PERMEABLE FILMS In accordance with embodiments of the invention, water-permeable or gas-permeable films can be prepared by the following method or variations thereof: (1) mixing an olefin interpolymer with polyurethane fibers such that the polyurethane fibers are dispersed in the olefin interpolymer; (2) forming a film from the mixture; (3) extracting a portion of the fibers on the surface of the film; and (4) optionally removing at least 50% of the fibers in the film. In some embodiments, antioxidants, slip agents, fillers, and/or tackifiers are added in addition to the polyurethane fibers. Mixing can be achieved by any mixing device, such as a roll mill or a kneader. The mixing is preferably carried out at an elevated temperature, e.g., from about 150 °C to about 300 °C. Films can be formed by any methods, such as those described above. Preferably, the films are formed by calendering at an elevated temperature, e.g., from about 150 °C to about 300 °C. Polyurethane fiber extraction can be achieved by immersing the film in a solvent that dissolves polyurethane but not the olefin interpolymer (e.g., dimethyl formamide). The immerse time and temperature determine the extent of polyurethane extraction. Generally, the extraction is conducted at or slightly above room temperature. For example, immersion in dimethyl formamide for about 5 minutes or more at about 30 °C. typically is sufficient to render the film water-permeable. Additional extraction of the fibers in the film can be achieved by further immersing the water-permeable film in a dimethyl formamide solution, water, or combination thereof for an extended period of time, for example, for about 5 to 10 minutes at about 40 °C.

Additional methods for making the water-permeable or breathable films exist. For example, the methods disclosed in U.S. Patents No. 6,096,014; 6,002,064; 5,055,338; and 4,777,073 may be modified to make the desired films. The disclosures of the all of the preceding patents are incoφorated by reference herein in their entirety.

In some embodiments, spandex fibers are used in the above matrix, although any polyurethane fibers are suitable. Spandex is a generic name for a fiber in which the fiber- forming substance is a long-chain synthetic polymer composed of at least 85% of a segmented polyurethane. It is a particular elastomeric polymer in fiber form which is a well-known component of clothing, particularly sportswear, which adds stretch to the clothing. Spandex is a urethane-containing polymer composed of alternating soft and hard regions within the polymer structure. Generally speaking, there are three methods for manufacturing fibers, including Spandex fibers, from polyurethane polymers: (1) dry- spinning; (2) wet-spinning, and (3) melt-spinning. Various spandex fibers are known in the art and can be used. For example, U.S. Patents No. 4,548,975, No. 4,973,647, No. 5,000,899, and No. 5,362,432, No. 5,644,015 (all of which are incorporated by reference herein in their entirety) disclose several types of spandex fibers, which can be used in embodiments of the invention. Spandex fibers are commercially available from Bayer under the tradename of DORLASTAN™ or from DuPont under the tradename of LYCRA™. Generally, spandex fibers with a diameter less than about 500 microns are used. In some embodiments, the fiber diameters are less than about 300 microns, less than about 200 microns, or less than about 100 microns. In other embodiments, the fiber diameters are less than about 70 microns, less than about 50 microns, less than about 30 microns, or less than about 15 microns. In some embodiments, cross-linked fibers may be mixed with an olefin interpolymer. Cross-linking can be effected by a silane compound, a peroxide compound, radiation, or any other method. EXAMPLES

The following examples are given to illustrate various embodiments of the invention. They do not intend to limit the invention as otherwise described and claimed herein. All numerical values are approximate. When a numerical range is given, it should be understood that embodiments outside the range are still within the scope of the invention unless otherwise indicated. In the following examples, various polymers were characterized by a number of methods. Performance data of these polymers were also obtained. Most of the methods or tests were performed in accordance with an ASTM standard, if applicable, or known procedures.

TEST METHODS The molecular weight of the polymer compositions is indicated using a melt index measurement according to ASTM D-1238, Condition 190°C/2.16 kg (formally known as "Condition (E)" and also known as 12) was determined. Melt index is generally inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt index, although the relationship is not linear. Interpolymer styrene content was determined using proton nuclear magnetic resonance (¹H NMR). The method is disclosed in U.S. Patent No. 6,156,842, which is incorporated by reference herein in its entirety.

Tensile Strength was determined by ASTM D-882-91, Procedure A except: Five replications of the test were made for each polymer blend tested. Grip separation was always 1 inch (2.54 cm). Grip separation speed was always 5 mm/min. Modulus was determined by ASTM D-882-91, Procedure A except: Five replications of the test were made for each polymer blend tested. Grip separation was always 1 inch (2.54 cm). Grip separation speed was always 5 mm min.

Elongation was determined by ASTM D-882-91, Procedure A except: Five replications of the test were made for each polymer blend tested. Grip separation was always 1 inch (2.54 cm). Grip separation speed was always 5 mm/min.

Toughness was determined by ASTM D-882-91, Procedure A2.1 except: Five replications of the test were made for each polymer blend tested. Grip separation was always 1 inch (2.54 cm). Grip separation speed was always 5 mm/min. Mechanical Testing: Shore A hardness was measured at 23 °C. based on ASTM-

D240. Tensile properties of the compression molded samples were measured using an Instron 1145 tensile machine. ASTM-D638 (microtensile) samples were tested at a crosshead speed of 5 in/min. The average of four tensile measurements is reported. Fj,, tensile energy at break, is the area under the tensile stress/strain curve. PREPARATION OF ESI-BASED FILMS

The following procedures were used to make an ESI based film.

(1) Chop polyurethane fibers (with a diameter of less than about 100 microns) to a length of about 5-10 mm by using a rotary crusher. The chopping was carried out at room temperature for about 5 minutes. (2) Add an ethylene styrene inteφolymer and the chopped polyurethane fibers to a roll mill or a kneader and process the mixture for abut 2 to 10 minutes at abut 210° C to about 230° C. Add a sizing agent (such as a siloxane or silane compound), if necessary to help prevent the crushing of fibers by shear stress.

(3) Add antioxidants (e.g., Irganox 1010) and additives (e.g., zinc stearate and calcium carbonate) and continue mixing for about 2 to 10 minutes at about 210° C to 230°

C. Avoid temperature exceeding 250° C.

(4) After the fibers are relatively uniformly dispersed in the ethylene styrene inteφolymer, prepare a film on a calender line at about 210 °C. to about 230 C.

(5) Immerse the film in dimethyl formamide (DMF) at about 30° C. for more than 5 minutes. A breathable film is obtained. Alternatively, immerse the film in DMF for about 1-5 minutes at 30° C. followed by immersion in water, the surface of the film became soft, similar to light suede type of artificial leather.

(6) Immerse the film in a water/DMF solution (with about 30 wt.% of DMF) at

40° C for about 5 to 10 minutes to obtain a water-permeable film. A typical formulation is as follows. The weight percentage is based on the amount of ESI.

ESI 100 wt.%

Spandex Fiber 20 - 200 wt.%

Irganox 1010 0.2 wt.% Zinc Stearate 1.0 wt.%

Calcium Carbonate 5.0 wt.%

"Breathable" films are those films which allow the transfer of gasses at moderate to high transmission rates. The gasses most commonly used to demonstrate a film's breathability are water vapor (sometimes referred to as moisture vapor) and oxygen. The moisture vapor transmission test (MNTR) and oxygen transmission test (OTR) measure the mass or volume of gas transported across the cross section of the film in a given unit of time at a defined set of environmental conditions. While the mechanism of gas transfer often differs from film to film, it is the total amount of gas that passes through the film which makes films breathable. Water vapor permeability can be measured according to ASTM 96 E (38° C, 90%RH) and ASTM 96 BW (38° C, 50%RH). Permeability is expressed in grams per m² and per day (g/m²/day). For a film with a thickness of about one mil or 25 microns, a MNTR of at least 100 g/m²/day is considered water-permeable. A MVTR of less than 350 g/m²/day is considered as "low water permeability," whereas a MVTR of greater than 500 g/m²/day "high water permeability." To be breathable, the O₂ transmission rate should be more than about 175 cc/m²-day-atmosphere (as measured according to ASTM D 3985 at 73 °F.), preferably more than about 250 cc/m²-day-atmosphere, and more preferably more than about 500 cc/m²-day-atmosphere.

EXAMPLE 1 An ESI polymer (designated here as "ESI #1") was obtained from The Dow

Chemical Company (see Table 1 for physical properties). Spandex fibers were obtained from Tae-Kwang Industrial Co. Ltd, Seoul, Korea under the trade name Acelon™. The chemical composition of the spandex fibers is given in Table 11, and the their selected physical properties are listed in Table 12. Table 11 Chemical Composition of Spandex Fibers

Five samples were formulated identically except that the spandex fibers were varied from about 25 wt.% to about 200 wt.% based on the weight of the ESI polymer. Each sample contained 100 wt.% of ESI #1, 0.5 wt.% of ZnSt, 0.2 wt.% of Irganox 1010, and 5 wt.% of CaCO₃. The spandex fiber content for the five samples were: 25 wt.%, 50 wt.%, 100 wt.%, 150 wt.% , and 200 wt.%, respectively. Water-permeable films were made according to the procedures described above. Selected physical properties of the water- permeable films were tested and are summarized in Table 13 below. TABLE 13

"before" refers to a film prior to immersion in DMF.

"after" refers to film subsequent to immersion in DMF and water.

As shown by the above data, excellent water permeability was obtained when about

100 wt.% to about 200 wt.% of spandex fibers was used (relative to the weight of ESI #1) after the film underwent immersion in a DMF solution and optionally in water. It should noted that all the samples could be easily calendered, unlike a typical polyurethane formulation which could not be calendered.

EXAMPLE 2

Six additional samples were made with identical components except that an ESI polymer with a varying styrene content or an ethylene/styrene/propylene teφolymer was used. Each sample had 150 wt.% of spandex fibers, 0.5 wt.% of ZnSt, 0.2 wt.% of Irganox 1010, and 5 wt.% of CaCO₃ (relative to the weight of the ESI polymer used). Four different

ESI polymers used were: ESI #1 (70.5 wt.% Styrene), ESI #2 (42 wt.% Styrene), ESI #3 (31 wt.% Styrene), and ESI #4 (31.5 wt.% Styrene). See Tables 1-4 for their respective physical properties. In addition to ESI polymers, two ethylene/styrene/propylene teφolymers designated here as EPSI #1 and EPSI #2 available from The Dow Chemical Company were also used: EPSI #1 comprises about 72 wt% ethylene, about 5 wt% propylene, and about 23 wt% styrene and has a melt index, I , of about 1; EPSI #2 comprises about 70 wt% ethylene, about 15 wt% propylene, about 15 wt% styrene and has a melt index, I₂, of about 1.

The data in Table 14 below appear to indicate that an ESI polymer with a higher styrene content (e.g., more than 50 wt.%, 60 wt.%, or 70 wt.% styrene) tends to yield higher water permeability.

TABLE 14

EXAMPLE 3

In the following examples, an ESI polymer was compounded with a TPU at desired weight ratios (e.g., from 70/30 to 40/60), using a general purpose single screw or twin screw extruder and pelletized under the following conditions: Zone temperature 380 °F.

Melt temperature 380 °F. Die temperature 400 °F. Adapter temperature 400 °F. Strand cut water temperature: 70 °F. Output: 25-300 pounds/hr

After compounding, the blends were extruded into sheet structures. In a typical extrusion process, a cap layer (e.g. ESI/TPU blends) is fed to a two layer co-extrusion die block to be extruded on top of an ABS substrate. Thickness of either layer may be controlled via the respective feed rates. The sheet is passed through a 3 roller system for cooling and, optionally, to be embossed. These flat sheets are typically thermoformed in post-processing where the interlayer adhesion is maintained through this process.

Twelve blends were made in a twin extruder from ESI #2 (an ESI polymer with 41.9% styrene and I₂ of 0.75) and one of the three thermoplastic urethane polymers: TPU #5 (with a wax content of 0.55 wt.%), TPU #6 (with a wax content of 0.2 wt.%), and TPU #7 (which was an experimental grade resin and is the same as TPU #5 except it has no wax). Both TPU #5 and TPU #6 are made from MDI and polyester adipates. The twelve blends were co-extruded with an ABS resin to make a multilayer sheet structure. For comparison, the ESI and the TPU resins were separately co-extruded with an ABS resin. The sheet structures were tested for various properties which are summarized in Table 15.

Table 15

Run # ESI #1 TPU Co-extrusion Adhesion Tensile Elongation Yield Embossment Scratch

(wt.%) (wt.%) Process (Cap & Strength (%} Strength Retention Resistance Substrate) (psi) (Psi) (80C/24hr)

#0-A 100 0 Good Poor 950 750 100 Poor Poor

#0-B 0 100 Poor Good Good Good

TPU #5

#1 70 30 Good Good 750 542 234 Good Good

#2 60 40 Good Good 630 489 245 Good Good

#3 50 50 Good Good 734 218 265 Good Good

#4 40 60 Good Good 1307 333 408 Good Good TPU #6

#5 70 30 Good Poor 703 532 229 Good Good

#6 60 40 Good Good 508 402 262 Good Good

#7 50 50 Good Good 666 282 289 Good Good

#8 40 60 Good Good 922 251 395 Good Good

TPU #7

#9 70 30 Good Poor 699 535 217 Good Good

#10 60 40 Good Good 696 538 219 Good Good

#11 50 50 Good Good 583 239 237 Good Good

#12 40 60 Good Good 580 220 258 Good Good

All twelve blends had good thermal stability and co-extruded well with the ABS resin (AG700 obtained from The Dow Chemical Company). In contrast, when the thermally unstable TPU was used alone as the cap layer material, the TPU decomposed in the high temperature extruder and caused process difficulty. As seen in above table, addition of 40% or more of the TPU to the ESI resulted in good interlayer adhesion between the ESI/TPU cap layer and the ABS substrate layer, and they passed the Hand Peel Test which is commonly used in the industry. Moreover, all twelve blends pass the embossment retention test at 80 °C for 24 hours. It was also observed that addition of TPU to ESI also improved the paintability, scratch resistance, and the HF weldability.

EXAMPLE 4

In this example, blends of ESI and TPU were injection-molded over an ABS substrate layer, and some of the injection molded parts were measured for ultimate stress, elongation, and hardness. The ESI polymer was ESI #1 (see Table 1), and the thermoplastic urethane polymers were: TPU #2 (made from MDI and polytetramethylene glycol resin and having a low ether content), TPU #5 (made from MDI and polyester polyadipate resin and having a high adipate content), TPU #8 (made from MDI and polyetramethylene glycol ether resin and having a high ether content), and TPU #9 (made from Noranol™ 5287 and about 30% MDI ). TPU #8 has the following characteristics.

The ESI and TPU were compounded by pellet blending after the TPU was dried in a forced air oven for a minimum of 2 hours. The blended pellets were melt mixed using a single screw extruder and stored in a water tight container. The ESI/TPU blends were subsequently sheet extruded using a single screw extruder to produce a sheet.

For an injection molded part, an ESI/TPU blend is over-molded to an ABS or polyethylene structural layer. In this process, care should be taken to ensure that there is shear rate compatibility between the ESI and TPU components. The typical molding conditions were as follow:

Extruder Temperature: 375-420 °F. Nozzle Temperature: 400 - 420 °F. Melt Injection Pressure: 500-1900 psi Hold Pressure: 200 - 900 psi

The results of the injection molding are summarized in Table 16.

Table 16

Polymer Polymer Ultimate Stress % Elongation Shore A Type 1 % Type 2 % Psi %

TPU #2 100 6808.5 549.6 88.5

ESI #1 25 TPU #2 75 981.3 210.4 88.6

ESI #1 50 TPU #2 50 DNT DNT DNT

ESI #1 75 TPU #2 25 DNT DNT DNT

1

TPU #5 100 4371 533.8 91.1

ESI #1 25 TPU #5 75 2715.3 371.7 90.7

ESI #1 50 TPU #5 50 2504.4 270.5 89.7

ESI #1 75 TPU #5 25 DNT DNT DNT

1

ESI #1 25 TPU #8 75 3050.7 31.4 96.7

ESI #1 50 TPU #8 50 DNT DNT DNT

ESI #1 75 TPU #8 25 DNT DNT DNT

1

ESI #1 25 TPU #9 75 568.8 219.1 84.6

ESI #1 50 TPU #9 50 592.1 122.2 84.6

ESI #1 75 TPU #9 25 DNT DNT DNT

"DNT" means "did not test."

EXAMPLE 5 In this example, ESI #3 (see Table 3) was blended with the TPUs of Example 4, and the resulting blends were injection molded in a manner similar to the procedures of Example 4. Table 17 summarizes some of the physical properties of the injection molded parts. TABLE 17

Polymer % Polymer % Ultimate Stress % Elongation Shore A psi %

ESI #3 25 TPU #2 75 881.6 275.2 87.7

ESI #3 50 TPU #2 50 DNT DNT DNT

ESI #3 75 TPU #2 25 DNT DNT DNT

I

ESI #3 25 TPU #5 75 2196.1 399 89.1

ESI #3 50 TPU #5 50 1340.4 379.1 88.2

ESI #3 75 TPU #5 25 2941.2 454 84.7

1

ESI #3 25 TPU #9 75 322.3 105.9 81.1

ESI #3 50 TPU #9 50 539.5 166.9 83.6

ESI #3 75 TPU #9 25 DNT DNT DNT

"DNT" means "did not test."

EXAMPLE 6

Additional blends were made and injection molded similar to the procedures of

Example 4. Table 18 summarizes some of the physical properties of the injection molded parts.

Table 18

ESI TPU Thickness Ultimate Elongation Energy to Yield Shore A

Stress Break Strength Type l % Type 2 % in psi % in-lb psi

ESI #1 100 0 0.044 2687.6 234.3 7.1 639.4 94.8

TPU #2 100 0.068 6808.5 549.6 3.8 225.7 88.5

ESI #1 25 TPU #2 75 0.067 2938.5 509.6 3.7 219.7 87.4

TPU #2 100 0.063 4371 533.8 6.2 388.9 91.1

ESI #1 25 TPU #2 75 0.066 2645.3 524.7 4 240.5 89.5

ESI #1 50 TPU #2 50 0.069 2376.5 333.6 6.8 393.9 91

TPU #8 100 0.071 5132.3 270.2 28.3 1608.9 98.3

ESI #1 25 TPU #8 75 0.075 4344.8 263.5 29.4 1564.5 98.3

TPU #9 100 0.068 1999.1 641.4 4.9 286.2 89.7

ESI #1 25 TPU #9 75 0.065 869.4 388.6 5.1 317.1 89.4

ESI #1 50 TPU #9 50 0.066 1351.9 246.6 6.6 399.7 90

ESI #3 100 0.046 5584.2 420 3.2 276 84.2

ESI #3 25 TPU #2 75 0.065 3057.1 694 2.6 156.7 85.9

ESI #3 25 TPU #2 75 0.063 2931 573 3.2 199.2 89.5

ESI #3 50 TPU #2 50 0.062 2051 477 3.7 237 86.4 ESI TPU Thickness Ultimate Elongation Energy to Yield Shore A

Stress Break Strength Type 1 % Type 2 % in psi % in-lb psi

ESI #3 75 TPU #2 25 0.064 2519 481 2.4 153 84.7

ESI #3 25 TPU #9 75 0.066 953 499 4 241 88.5

ESI #3 50 TPU #9 50 0.065 959 402 4 244 86

ESI #1 65 TPU #1 35 0.023 3454 128 27 904

ESI #1 65 TPU#1 35 0.012 3757 76 17 904

ESI #3 85 TPU #6 15 0.015 4219 376 14 3696

Examples 4-6 appear to suggest that good injection moldability can be obtained with an ESI/TPU blend (in the absence of a compatibilizer) when the TPU has a relatively lower level of polar substituents. For example, TPU #5 is made from polyester and adipate and has more polar substituents than TPU #2. TPU #8 has nearly three times the level of polar groups than TPU #2. Therefore, when good injection moldability without using a compatibilizer is desired, a TPU with a low level of polar substituents should be blended with an ESI. Preferably, the TPU does not have more than one time the polar substituents in TPU #2. More preferably, the TPU should have a similar or lower amount of polar groups to that of TPU #2.

It should be noted that the compatibility between the ESI and TPU can be improved by using a compatibilizer in the blend. For example, maleic anhydride-grafted ESI or maleic anhydride-grafted polyolefin can be used as a compatibilizer. These maleic anhydride grafted polymer can be obtained, for example, by the methods described in U.S. Patent No. 4,762,890, which is incorporated by reference in its entirety.

EXAMPLE 7 This example shows that addition of a thermoplastic urethane polymer (e.g., TPU #5) to an ESI polymer (e.g., ESI #1 or ESI #3) can improve the heat resistance of the resulting blend as measured by thermomechanical analysis (TMA). Thermomechanical Analysis data were generated using a Perkin Elmer TMA 7 series instrument. The temperature for probe penetration to 1 mm depth on 2 mm thick compression molded parts using a heating rate of 5 °C./min and a load of 1 Newton was used as a measure of upper service temperature. The results are plotted in Figures 1-2. EXAMPLE 8

This example shows that TPU #1 has more significant effect on the heat stability of a blend including ESI #1 or ESI # 2. In this example, procedures similar to Example 7 were followed. The results were summarized in Figures 3-4.

EXAMPLE 9

This example demonstrates that the use of a compatibilizer does not change the physical properties of the blends including TPU #5. In this example, procedures similar to Example 4 were followed. The compatibilizer used in this example was a blend comprising about 49.5 wt.% ESI #1, about 50 wt.% maleic anhydride-grafted polyethylene (0.52 wt.% grafted maleic anhydride), and about 0.5 wt.% ethylene diamine. The results are summarized in Table 19.

Table 19

As seen in Table 19, there is no statistically significant difference in the physical properties between blends with a compatibilizer and without a compatibilizer. As such, a compatibilizer is not necessary for certain blends in accordance with embodiments of the invention.

As demonstrated above, embodiments of the invention provide a blend of substantially random olefin interpolymer and a urethane polymer. The blend balances the desirable attributes of each component. For example, the blend has improved processability in molding, overmolding, and calendering. It also has improved thermal stability, haptics (soft, leathery feel), heat resistance, impact resistance, low temperature flexibility, chemical resistance, and improved HF weldability. When the blend comprises a substantially random olefin interpolymer and polyurethane fibers, the blend or mixture can be calendered. Such blends or mixtures also have improved processability and can be produced by a multitude of methods. The water-permeable films made according to embodiments of the invention have good water permeability and improved abrasion resistance and chemical resistance. Additional characteristics and advantages are apparent to those skilled in the art. While the invention has been described with a limited number of embodiments, these specific embodiments are not intended to limit the scope of the invention as otherwise described and claimed herein. Modification and variations from the described embodiments exist. For example, while an ethylene styrene interpolymer is used in the blend, it may be substituted by other polymers, such as HDPE, LLDPE (e.g., ethylene/ 1-butene copolymer, ethylene/ 1-hexene copolymer, ethylene/ 1-octene copolymer), ENA, EAA, SBC, etc., especially when polyurethane fibers are blended. Blend compatibility may be important for some embodiments but not important for other embodiments, such as when fibers are blended with an olefin inteφolymer. An ESI polymer is used various embodiments. But this does not imply all embodiments include an ESI polymer. It should be understood that some blends do not comprise an ESI polymer. While the processes are described as comprising one or more steps, it should be understood that these steps may be practiced in any order or sequence unless otherwise indicated. These steps may be combined or separated. Finally, any number disclosed herein should be construed to mean approximate, regardless of whether the word "about" or "approximate" is used in describing the number. The appended claims intend to cover all such variations and modifications as falling within the scope of the invention.

Claims

What is claimed is:

1. A polymer blend consisting essentially of:

(A) one substantially random olefin interpolymer comprising:

(1) polymeric units derived from: (i) at least one vinyl aromatic monomer, or

(ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or

(iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer; and (2) polymeric units derived from at least one C_2-20 α-olefin; and optionally

(3) polymeric units derived from one or more ethylenically unsaturated polymerizable monomers other than those of (1) and (2); and

(B) a urethane polymer compatible with the olefin interpolymer, wherein the blend is substantially free of a compatibilizer.

2. A polymer blend comprising:

(A) at least one substantially random olefin interpolymer comprising

(1) polymeric units derived from:

(i) at least one vinyl aromatic monomer, or (ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or

(iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, and

(2) polymeric units derived from at least one C_2-20 α-olefin; and optionally

(3) polymeric units derived from one or more ethylenically unsaturated polymerizable monomers other than those of (1) and (2); and

(B) at least one urethane polymer compatible with the olefin interpolymer, wherein the blend is substantially free of a compatibilizer.

3. The polymer blend of claim 1 or 2, wherein the substantially random olefin interpolymer is an ethylene styrene interpolymer.

4. The polymer blend of claim 3, wherein the ethylene styrene interpolymer has a styrene content of about 50 mol.% or less.

5. The polymer blend of claim 3, wherein the ethylene styrene inteφolymer has a styrene content of about 1 mol.% to about 25 mol.%.

6. The polymer blend of claim 3, wherein the ethylene styrene inteφolymer has a styrene content of about 25 mol.% to about 50 mol.%.

7. The polymer blend of claim 3, wherein the ethylene styrene inteφolymer has a styrene content of about 10 mol.% to about 40%.

8. The polymer blend of claim 3, wherein the ethylene styrene inteφolymer has a styrene content of about 20 mol.% to about 30%.

9. The polymer blend of claim 3, wherein the ethylene styrene inteφolymer has a styrene content of about 15 mol.% to about 45%.

10. The polymer blend of claim 1 or 2, wherein the olefin inteφolymer is from about 1% to about 50% by weight of the blend.

11. The polymer blend of claim 1 or 2, wherein the olefin inteφolymer is from about 1% to about 25% by weight of the blend.

12. The polymer blend of claim 1 or 2, wherein the olefin inteφolymer is from about 51 % to about 99% by weight of the blend.

13. The polymer blend of claim 1 or 2, wherein the urethane polymer is a thermoplastic urethane polymer.

14. The polymer blend of claim 13, wherein the thermoplastic urethane polymer includes a low level of polar groups.

15. The polymer blend of claim 14, wherein the thermoplastic urethane polymer includes less than twenty polar groups per repeating unit.

16. The polymer blend of claim 14, wherein the thermoplastic urethane polymer includes less than fifteen polar groups per repeating unit.

17. The polymer blend of claim 14, wherein the thermoplastic urethane polymer includes less than ten polar groups per repeating unit.

18. The polymer blend of claim 14, wherein the thermoplastic urethane polymer includes less than eight polar groups per repeating unit.

19. The polymer blend of claim 14, wherein the thermoplastic urethane polymer includes less than five polar-groups per repeating unit.

20. The polymer blend of claim 14, wherein the thermoplastic urethane polymer includes less than three polar groups per repeating unit.

21. An article of manufacture comprising the polymer blend of claim 1 or 2.

22. The article of manufacture of claim 21, wherein the article is a sheet structure comprising a layer of the polymer blend over a substrate.

23. The article of manufacture of claim 22, wherein the substrate is selected from the group consisting of ABS, nylon, polyphenylene oxide, and high impact polystyrene.

24. The article of manufacture of claim 22, wherein the sheet structure is obtained by coextrusion.

25. The article of manufacture of claim 22, wherein the sheet structure is obtained by injection molding.

26. The article of manufacture of claim 22, wherein the sheet structure is obtained by compression molding.

27. The article of manufacture of claim 22, wherein the sheet structure is obtained by slush molding.

28. A method of making an article, comprising: obtaining a polymer mixture comprising polyurethane fibers dispersed in a matrix of a substantially random olefin inteφolymer, the mixture being calenderable or extrudable; and forming a film or a sheet from the polymer mixture, wherein the substantially random olefin inteφolymer comprises:

1) polymeric units derived from:

(i) at least one vinyl aromatic monomer, or (ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (iii) a combination of at least one aromatic vinyl monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer; and

(2) polymeric units derived from at least one C_2-20 α-olefin; and optionally

(3) polymeric units derived from one or more ethylenically unsaturated polymerizable monomers other than those of (1) and (2).

29. The method of claim 28, further comprising removing the polyurethane fibers on the surface of the film or sheet.

30. The method of claim 28, further comprising removing a sufficient amount of the polyurethane fibers in the film or sheet to render the film or sheet breathable.

31. The method of claim 28, further comprising removing a sufficient amount of the polyurethane fibers in the film or sheet to render the film or sheet water-permeable.

32. The method of claim 28, wherein the olefin inteφolymer is an ethylene styrene inteφolymer.

33. The method of claim 28, wherein the polyurethane fibers are spandex fibers.

34. The method of claim 28, wherein the fibers have an average diameter of less than about 500 microns.

35. The method of claim 28, wherein the fibers have an average diameter of less than about 200 microns.

36. The method of claim 28, wherein the fibers have an average diameter of less than about 100 microns.

37. The method of claim 28, wherein the fibers have an average diameter of less than about 50 microns.

38. The method of claim 28, wherein the fibers have an average diameter of less than about 30 microns.

39. The method of claim 34, 35, 36, 37, or 38 , wherein the fibers have an average length of about 5 mm to about 10 mm.

40. The method of claim 28, wherein the polyurethane fibers are not compatible with the olefin inteφolymer.

41. The method of claim 28, wherein the polyurethane fibers are uniformly dispersed in the matrix of the olefin inteφolymer.

42. The method of claim 28, wherein the polymer blend is obtained by mixing the polyurethane fibers with the olefin inteφolymer.

43. A film obtained according to the method of claim 28, 29, 30, or 31.

44. A sheet obtained according to the method of claim 28, 29, 30, or 31.