EP1126969A1

EP1126969A1 - Fabricated articles produced from alpha-olefin/vinyl or vinylidene aromatic and/or hindered aliphatic or cycloaliphatic vinyl or vinylidene interpolymer compositions

Info

Publication number: EP1126969A1
Application number: EP99958674A
Authority: EP
Inventors: Yunwa W. Cheung; Martin J. Guest; William R. Van Volkenburgh; Teresa P. Karjala
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1998-11-06
Filing date: 1999-10-26
Publication date: 2001-08-29
Also published as: WO2000027615A1; AR021231A1; JP2002529547A; AU1598800A; WO2000027615A9

Abstract

This invention is related to fabricated articles prepared from polymer compositions which comprise at least one substantially random interpolymer comprising polymer units derived from one or more α-olefin monomers with specific amounts of one or more vinyl or vinylidene aromatic monomers and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers in combination with minor amounts of one or more thermoplastic polymers which are immiscible with the substantially random interpolymer component. The fabricated articles are prepared in a final melt processing step comprising a flow fabrication process which can be characterized by the shear field applied in the process. Following melt fabrication, the blend compositions exhibit a unique mixing behavior and final solid state structure such that, even at low concentrations of the immiscible thermoplastic polymer blend component, the resulting fabricated articles exhibit unexpected combinations of properties included, but not limited to, modulus, high temperature performance, chemical resistance and transparency. The fabricated articles of the invention covers films, tapes, sheets, fibers, foams, injection molded articles, injection/blow molded articles and extruded profiles.

Description

FABRICATED ARTICLES PRODUCED FROM ALPHA-OLEFIN/VINYL OR VINYLIDENE AROMATIC AND/OR HINDERED ALIPHATIC OR CYCLOALIPHATIC VINYL OR VINYLIDENE INTERPOLYMER COMPOSITIONS

This application claims the benefit of U.S. Provisional Application No.

60/107,310 filed November 6, 1998.

This invention is related to fabricated articles prepared from polymer compositions which comprise at least one substantially random interpolymer comprising polymer units derived from one or more α-olefin monomers with specific amounts of one or more vinyl or vinylidene aromatic monomers and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers in combination with minor amounts of one or more thermoplastic polymers which are immiscible with the substantially random interpolymer. The fabricated articles are prepared in a final melt processing step comprising a flow fabrication process which can be characterized by the shear field applied in the process. Following specific melt fabrication conditions, the blend compositions exhibit a unique mixing behavior and final solid state structure such that, even at low concentrations of the immiscible thermoplastic polymer blend component, the resulting fabricated articles exhibit an unexpected combination of properties included, but not limited to, modulus, high temperature performance and transparency.

The fabricated articles can be used in applications including, but not limited to, films, tapes, sheets, fibers, foams, injection molded articles, injection/blow molded articles, injection molded flexible goods, extruded profiles, toys, injection molded toys, housewares, paintable goods, furniture, automotive parts, lawn and garden appliances, small appliances, large appliances, and the like.

The generic class of materials covered by α-olefin/hindered vinylidene monomer substantially random interpolymers and including materials such as α- olefm vinyl aromatic monomer interpolymers, described in US 5703187, are known in the art and offer a range of material structures and properties which makes them useful for varied applications. The interpolymers can find utility as compatibilizers for blends of polyethylene and polystyrene as described in US 5,460,818. The utility of the interpolymers in film and sheet structures has been further described, for example in WO 95/32095

Although of utility in their own right, Industry is constantly seeking to improve the applicability of these interpolymers, for example to extend the temperature range of application. Blend compositions are finding increasingly utility in performance applications which require a combination of properties unavailable in a single polymer. WO 97/115546 and copending US Application No. 08/1 17136 by M. J. Guest, et al., filed on 23 July, 1997 describes blends of substantially random interpolymers; WO 97/15533 describes blends of substantially random interpolymers and polyethylene; copending US Provisional Application No. 60/077663 by S. A. Ogoe et al., filed on 11 March, 1998, describes blends of substantially random interpolymers and polycarbonate; copending US Application No. 08/950983 by Y. W. Cheung et al., filed on 15 October, 1997 describes blends of substantially random interpolymers and poly(vinyl chloride); U.S. Patent No. 5,741,857 describes blends of substantially random interpolymers and styrenic block copolymers; and WO 96/14233 and copending US Application No. 08/709418 by K. Sikkema et al., filed on 4 September, 1997 describes blends of substantially random interpolymers and polystyrene, all of which patents and applications are incorporated herein by reference.

Blending technology is recognized as being complex, particularly for so-called immiscible polymer/polymer systems. Melt processing operations are often employed to blend polymers and manufacture solid parts from mixed polymer systems. For immiscible polymer-polymer blends, the final solid state properties are known to be dependent not only upon the selection of blend components and composition ratio, but are also determined by the solid state morphology (see for example Quintens et al., Polym. Eng. Sci. Vol 30, pages 1474 et seq. [1990]). The underlying technology is one of morphology development for which the rheological behaviour of the blend components, interfacial characteristics and processing conditions are generally accepted as important (see for example Van Oene, J. Coll. Interface Sci. Vol. 40, pages 448 et seq. [1972]). Basic descriptors for the types of morphology include matrix-inclusion (or complex occlusion), co-continuous and fibrillar or lamellar structures. In polymer blending technology, it is well known that the addition of a minor volume fraction of a second, immiscible component B to a major volume fraction of component A typically results in an A B matrix/inclusion type morphology. In such a structure, many of the properties such as modulus and upper service temperature are essentially determined by those properties of the matrix phase.

We have now surprisingly found that articles fabricated under melt processing operations having a critical shear rate of greater than about 30 sec^"' exhibit substantially improved properties if such articles comprise a blend of at least one substantially random interpolymer and minor amounts of one or more thermoplastic polymers which are mutually immiscible. The improved properties include but are not limited to modulus, toughness, upper service temperature, transparency and chemical resistance. The property to be improved can be selected based on a choice of the minor component of the blend. For example the use of polystyrene as component B leads to improvements in modulus and upper service temperature, whereas the use of a high density polyethylene as component B additionally leads to improvements in properties such as chemical resistance. The blend components A and B can have a wide range of molecular weights and molecular weight distributions, and these are selected dependent upon the performance requirements of the final fabricated article.

The present invention pertains to fabricated articles made by a high critical shear rate melt processing operation and comprising a blend of at least two polymers which are mutually immiscible, said blend comprising from 55 to 95 wt percent (based on the combined weights of Components A and B) of

(A) at least one substantially random inteφolymer. which comprises; ( 1 ) polymer units derived from;

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

(2) polymer units derived from ethylene and/or at least one C₃.₂₀ α-olefin; and,

(B) at least one thermoplastic polymer which is immiscible with Component (A) and is present in an amount of from 5 to 45 wt percent (based on the combined weights of Components A and B); and wherein

(C) said high critical shear rate is greater than about 30 sec^"1

Figure 1 is a graph showing the storage modulus as a function of the shear rate at which the extrudate was extruded at a temperature of Tg + 20°C.

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, for example, temperature, pressure, time 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 "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 "inteφolymer" is used herein to indicate a polymer wherein at least two different monomers are polymerized to make the inteφolymer. This includes copolymers, teφolymers, etc.

The term "fabricated article" as used herein refers to fabricated compositions comprising films, fibers, foams, injection molded articles, injection-blow molded articles and extruded profiles.

The term "high shear rate" as used herein refers to a critical shear rate of greater than or about 30 sec^"'.

The term "high shear rate processing operation" as used herein refers to a process for preparing a fabricated article in which the polymer blend is subjected to a high shear rate. Examples of high shear rate processing operations would be film blowing and injection molding. The term "low shear rate" as used herein refers to a critical shear rate of less than or equal to about 30 sec^"' .

The term "low shear rate processing operation" as used herein refers to a process for preparing a fabricated article in which the polymer blend is subjected to a low shear rate. One example of a low shear rate processing operation would be compression molding.

The term "mutually immiscible" as used herein refers to individual components blend components which are immiscible in each other. For example, polymers are considered to be immiscible when, in a blend of the two or more polymers, the individual blend components can still be identified by electron microscopy as discrete domains, or by their characteristic thermal transitions (such as the glass transition, Tg) which can still be discerned.

The present invention provides fabricated articles prepared by melt processing a blend of at least two polymers under high shear rate conditions. The blends comprise Component (A) being at least one substantially random inteφolymer (comprising polymer units derived from one or more α-olefin monomers with specific amounts of one or more vinyl or vinylidene aromatic monomers and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers) and Component (B) being one or more other thermoplastic polymer components which are immiscible with, and present in minor amounts relative to, Component (A).

In a preferred embodiment the articles of the present invention meet the criterion that, at temperatures at least 20°C in excess of the blend Tg (DSC), the elastic modulus of the article when prepared under high shear rate conditions is at least twice, preferably three times and more preferably ten times that of the article when prepared under low shear rate conditions.

The immiscible thermoplastic polymer components (B) of the blend can include, but is not limited to, one or more styrenic homopolymers or copolymers, α- olefin homopolymers or copolymers, engineering thermoplastics, styrenic block copolymers, elastomers, or vinyl halide polymers.

The term "substantially random" (in the substantially random inteφolymer comprising polymer units derived from one or more α-olefin monomers with one or more vinyl or vinylidene aromatic monomers and/or aliphatic or cycloaliphatic vinyl or vinylidene monomers) as used herein means that the distribution of the monomers of said inteφolymer 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 inteφolymers do not contain more than 15 percent of the total amount of vinyl aromatic monomer in blocks of more than 3 units. This means that in the carbon ⁿ NMR spectrum of the substantially random inteφolymer, 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.

The substantially random inteφolymers used to prepare the articles of the present invention include inteφolymers prepared by polymerizing ethylene and/or one or more α-olefins with one or more vinyl or vinylidene aromatic monomers and/or one or more sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers, and optionally other polymerizable monomers.

Suitable α-olefins include for example, α-olefins containing from 3 to 20, preferably from 3 to 12, more preferably from 3 to 8 carbon atoms. Particularly suitable are propylene, butene-1, 4-methyl-l-pentene, heptene-1, hexene-1 or octene-1. Also suitable is ethylene in combination with one or more α-olefins containing from 3 to 20 carbon atoms, and particularly ethylene in combination with one or more selected from propylene, butene-1, pentene-1, 4-methyl-l-pentene, hexene-1, heptene-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,.₁₀ alkyl or C₆.₁₀ aryl substituted norbornenes, with an exemplary inteφolymer being ethylene/styrene/norbornene.

Suitable vinyl or vinylidene aromatic monomers which can be employed to prepare the inteφolymers include, for example, those represented by the following formula: Ar

I (CH₂)_n

Rⁱ _ C = C(R2)₂ wherein R' is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 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 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C -alkyl, and C -haloalkyk and n has a value from zero to 4, preferably from zero to 2, most preferably zero. Exemplary vinyl aromatic monomers include styrene, vinyl toluene, α -methyl styrene. 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- (C, - C₄) or phenyl-ring substituted derivatives of styrene, such as for example, ortho-, meta-, and para-methylstyrene, the ring halogenated styrenes, para-vinyl toluene or mixtures thereof, and the like. A more preferred aromatic vinyl monomer is styrene. By the term "sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene compounds", it is meant addition polymerizable vinyl or vinylidene monomers corresponding to the formula:

A I R¹ — C = C(R²)₂

wherein A¹ is a sterically bulky, aliphatic or cycloaliphatic substituent of up to 20 carbons, R' is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 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 4 carbon atoms, preferably hydrogen or methyl; or alternatively R¹ and A¹ together form a ring system. 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. α-Olefin monomers containing from 3 to 20 carbon atoms and having a linear aliphatic structure such as propylene, butene-1, hexene-1 and octene-1 are not considered as hindered aliphatic monomers.

The substantially random inteφolymers 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.

One method of preparation of the substantially random inteφolymers includes polymerizing a mixture of polymerizable monomers in the presence of one or more metallocene or constrained geometry catalysts in combination with various cocatalysts. The substantially random inteφolymers 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 incoφorated herein by reference in their entirety. Preferred operating conditions for such polymerization reactions are pressures from atmospheric up to 3000 atmospheres and temperatures from -50°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 inteφolymers 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 incoφorated herein by reference.

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

Cp l _{R l}

Cp ² R²

where Cp' and Cp² are cyclopentadienyl groups, indenyl groups, fluorenyl groups, or substituents of these, independently of each other; R¹ and R² 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 crosslink Cp' and Cp²).

The substantially random α-olefin/vinyl aromatic inteφolymers 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 incoφorated herein by reference in their entirety.

Also suitable are the substantially random inteφolymers 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 by Francis J. Timmers et al. These inteφolymers 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, for example 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-13 NMR peaks but with slightly different chemical shifts.

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

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 30 preferably from 1 to 20 more preferably from 1 to 10 carbon or silicon atoms; each R' is independently, each occurrence, H. halo, hydrocarbyl, hyrocarbyloxy. silahydrocarbyl, hydrocarbylsilyl containing up to 30 preferably from 1 to 20 more preferably from 1 to 10 carbon or silicon atoms or two R groups together can be a C ₀ 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 30 preferably from 1 to 20 more preferably from 1 to 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-l ,3- butadiene, racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl)zirconium di- Cl-4 alkyl, racemic-(dimethylsilanediyl)-bis-(2-methyl-4-phenylindenyl) zirconium di- C 1 -4 alkoxide. or any combination thereof and the like.

It is also possible to use the following titanium-based constrained geometry catalysts, [N-( 1 , 1 -dimethylethyl)- 1 , 1 -dimethyl- 1 - [( 1 ,2,3,4,5-η)- 1 ,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-propyι)(l,2,3,4,5-η)-l- indenyl)(tert-butyl amido)dimethylsilane titanium dimethyl, or any combination thereof and the like.

Further preparative methods for the interpolymers finding utility in the present invention have been described in the literature. United States patent number 5,652,315 issued to Mitsui Toatsu Chemicals, Inc. describes the copolvmerization of ethylene and styrene. 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 riCl₄/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 TiCyNdCL/ MgCl₂ /Al(Et)₃ catalyst. Sernetz and Mulhaupt, (Macromol. Chem. Phys.. v. 197, pp. 1071-1083, 1997) have described the influence of polymerization conditions on the copolymerization of styrene with ethylene using Me₂Si(Me₄Cp)(N-tert- butyl)TiCl₂/methylaluminoxane 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. Polym. Chem.) Volume 38, pages 349, 350 [1997]). The manufacture of α-olefin/vinyl aromatic monomer inteφolymers 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 inteφolymer component are incoφorated herein by reference. The random copolymers of ethylene and styrene as disclosed in Polymer Preprints Vol 39, No. 1, March 1998 by Toru Aria et al. can also be employed as blend components of the present invention.

The immiscible thermoplastic polymer components (B) of the blend can include, but are not limited to, one or more styrenic homopolymers or copolymers, ethylene and/or α-olefin homopolymers or copolymers, thermoplastic polyolefms, engineering thermoplastics, styrenic block copolymers, elastomers, or vinyl halide polymers.

The styrenic homopolymers or copolymers employed as component (B) in the blends of the present invention are polymers of vinyl or vinylidene aromatic monomers and include homopolymers or copolymers of one or more vinyl or vinylidene aromatic monomers, or an copolymer of one or more vinyl or vinylidene aromatic monomers and one or more monomers copolymerizable therewith other than an aliphatic α-olefin. Suitable vinyl or vinylidene aromatic monomers are represented by the following formula:

Ar I R¹ — C = CH₂

Wherein R' is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C_M- alkyl, and C -haloalkyl. Exemplary vinyl or vinylidene aromatic monomers include styrene, para-vinyl toluene, α-methylstyrene, t-butyl styrene, chlorostyrene, including all isomers of these compounds, etc. Styrene is a particularly desirable vinyl aromatic monomer for the vinyl aromatic polymers used in the practice of the present invention.

A preferred polymer is atactic polystyrene. While preparing the substantially random inteφolymer component (A) of the present invention, atactic vinyl aromatic homopolymer may be formed due to homopolymerization of the vinyl aromatic monomer at elevated temperatures. For the puφose of the present invention, the atactic vinyl aromatic homopolymer, typically atactic polystyrene, constitutes at least part of the immiscible blend component (B).

Examples of suitable copolymerizable comonomers in Blend Component (B), other than a vinyl or vinylidene aromatic monomer include, for example, C₄-C₆ conjugated dienes, especially butadiene or isoprene, n-phenyl maleimide, acrylamide, ethylenically-unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile, ethylenically-unsaturated mono- and difunctional carboxylic acids and derivatives thereof such as esters and, in the case of difunctional acids, anhydrides, such as acrylic acid, C_M- alkylacrylates or methacrylates, such as n-butyl aery late and methyl methacrylate. maleic anhydride, etc. In some cases it is also desirable to copolymerize a cross-linking monomer such as a divinyl benzene into the vinyl or vinylidene aromatic polymer. The polymers of vinyl or vinylidene aromatic monomers with other copolymerizable comonomers preferably contain, polymerized therein, at least 50 percent by weight and, preferably, at least 65 percent by weight of one or more vinyl or vinylidene aromatic monomers. Preferred styrenic copolymers are styrene/acrylonitrile (SAN) copolymers, styrene/maleic anhydride copolymers (SMA), styrene/methyl methacrylate copolymers (S-MMA) and the rubber modified copolymers such as acrylonitrile/butadiene/styrene copolymer (ABS). The number average molecular weight M_n of the styrenic homopolymers and copolymers used as blend components of the present invention is from 1000 to 1,000,000, preferably from 5,000 to 500.000. even more preferably from 10,000 to 350,000, and the molecular weight distribution M M_n is from 1.005 to 20.000.

Rubber modified vinyl aromatic polymers can be prepared by polymerizing the vinyl aromatic monomer in the presence of a predissolved rubber to prepare impact modified, or grafted rubber containing products, examples of which are described in US patents 3,123,655, 3,346,520, 3,639,522, and 4,409,369 which are herein incorporated by reference. The rubber is typically a butadiene or isoprene rubber, preferably polybutadiene. Preferably, the rubber modified vinyl aromatic polymer is high impact polystyrene (HIPS). Component (B) may also be a flame resistant rubber modified styrenic blend composition. The flame resistant compositions are typically produced by adding flame retardants to a high impact polystyrene (HIPS) resin. The addition of flame retardants lowers the impact strength of the HIPS which is restored back to acceptable levels by the addition of impact modifiers, typically styrene-butadiene- styrene (SBS) block copolymers. The final compositions are referred to as ignition resistant polystyrene (IRPS).

Suitable polymers to be employed as component (B) also include vinyl or vinylidene aromatic polymers having a high degree of isotactic or syndiotactic configuration. By a high degree of syndiotactic configuration is meant that the stereochemical structure is mainly of syndiotactic configuration, the stereostructure in which phenyl groups or substituted phenyl group as side chains are located alternately at opposite directions relative to the main chain consisting of carbon-carbon bonds. Tacticity is quantitatively determined by the 13C-nuclear magnetic resonance method, as is well known in the art. Preferably, the degree of syndiotacticity as measured by 13C NMR spectroscopy is greater than 75 percent r diad, more preferably greater than 90 percent r diad. Suitable examples of syndiotactic polymers include polystyrene, poly(alkylstyrene), poly(halogenated styrene), poly(alkoxystyrene), poly(vinylbenzoate), the mixtures thereof, and copolymers containing the above polymers as main components. Poly(alkylstyrene) includes poly(methylstyrene), poly(ethylstyrene) poly(isopropylstyrene), poly(tert-butylstyrene), etc., Poly(halogenated styrene) includes, poly(chlorostyrene), poly(bromostyrene), and poly(fluorostyrene), etc. Poly (alkoxy styrene) includes, poly (methoxy styrene), poly(ethoxystyrene), etc.

Preferred styrenic copolymers having tacticity and employed as component (B) are syndiotactic polystyrene (SPS) which usually has a weight-average molecular weight of 10,000 to 10.000,000, preferably 100.000 to 5,500,000 with a number-average molecular weight of 5,000 to 5,500,000. preferably 50,000 to 2,500,000. The syndiotactic polymer has a melting point of 160 to 310°C.

The ethylene and/or α-olefin homopolymers or inteφolymers employed as blend component (B) in the blends of the present invention are polymers comprising ethylene and/or C₃-C₂₀ α- olefins. The α-olefin homopolymers and inteφolymers include polypropylene, propylene/C₄-C₂₀ α- olefin copolymers, polyethylene, and ethylene/C₃-C₂₀ α- olefin copolymers. The inteφolymers can be either heterogeneous ethylene/α-olefin inteφolymers or homogeneous ethylene/α-olefin inteφolymers, including the substantially linear ethylene/α-olefin inteφolymers.

Also included are those aliphatic α-olefins having from 3 to 20 carbon atoms and containing polar groups. Suitable aliphatic α-olefin monomers which introduce polar groups into the polymer include, for example, ethylenically unsaturated nitriles such as acrylonitrile, methacrylonitrile. ethacrylonitrile, etc.: ethylenically unsaturated anhydrides such as maleic anhydride; ethylenically unsaturated amides such as acrylamide, methacrylamide etc.: ethylenically unsaturated carboxylic acids (both mono- and difunctional) such as acrylic acid and methacrylic acid, etc.; esters (especially lower, for example C,-C₆, alkyl esters) of ethylenically unsaturated carboxylic acids such as methyl methacrylate, ethyl acrylate, hydroxyethylacrylate, n-butyl acrylate or methacrylate, 2-ethyl-hexylacrylate etc.; ethylenically unsaturated dicarboxylic acid imides such as N-alkyl or N-aryl maleimides such as N-phenyl maleimide, etc. Preferably such monomers containing polar groups are acrylic acid, vinyl acetate, maleic anhydride and acrylonitrile. Exemplary polymers are ethylene vinyl acetate (EVA) and ethylene vinyl alcohol (EVOH). Halogen groups which can be included in the polymers from aliphatic α-olefϊn monomers include fluorine, chlorine and bromine; preferably such polymers are chlorinated polyethylenes (CPEs).

Heterogeneous inteφolymers are differentiated from the homogeneous inteφolymers in that in the latter, substantially all of the inteφolymer molecules have the same ethylene/comonomer ratio within that inteφolymer, whereas heterogeneous inteφolymers are those in which the inteφolymer molecules do not have the same ethylene/comonomer ratio. The term "broad composition distribution" used herein describes the comonomer distribution for heterogeneous inteφolymers and means that the heterogeneous inteφolymers have a "linear" fraction, multiple melting peaks (i.e., exhibit at least two distinct melting peaks) by DSC and have a degree of branching less than or equal to 2 methyls/1000 carbons in 10 percent (by weight) or more, preferably more than 15 percent (by weight), and especially more than 20 percent (by weight of the polymer). The heterogeneous inteφolymers also have a degree of branching equal to or greater than 25 methyls/1000 carbons in 25 percent or less (by weight of the polymer), preferably less than 15 percent (by weight), and especially less than 10 percent (by weight of the polymer).

The Ziegler catalysts suitable for the preparation of the heterogeneous component of the current invention are typical supported, Ziegler-type catalysts which are particularly useful at the high polymerization temperatures of the solution process. Examples of such compositions are those derived from organomagnesium compounds, alkyl halides or aluminum halides or hydrogen chloride, and a transition metal compound. Examples of such catalysts are described in U.S. Pat Nos. 4,314,912 (Lowery, Jr. et al.), 4,547,475 (Glass et al.), and 4,612,300 (Coleman, III). Suitable catalyst materials may also be derived from a inert oxide supports and transition metal compounds. Examples of such compositions suitable for use in the solution polymerization process are described in U.S. Pat No. 5,420,090 (Spencer et al).

The heterogeneous polymer component can be an ethylene and/or α-olefin homopolymer preferably polyethylene or polypropylene, or, preferably, an inteφolymer of ethylene with at least one C3-C20 α-olefin and/or C4-C18 diolefins. Heterogeneous copolymers of ethylene and 1 -butene, ethylene and 1 -pentene, ethylene and 1 -hexene and ethylene and 1 -octene are especially preferred.

The relatively recent introduction of metallocene-based catalysts for ethylene/α- olefin polymerization has resulted in the production of new ethylene inteφolymers.

Such polymers are known as homogeneous inteφolymers and are characterized by their narrower molecular weight and composition distributions relative to, for example, traditional Ziegler catalyzed heterogeneous polyolefin polymers. Substantially linear ethylene/α-olefin polymers and inteφolymers which can be employed as component (B) of the present invention are herein defined as in U.S. Patent No. 5,272.236 (Lai et al), and in U.S. Patent No. 5,278,272.

The homogeneous polymer component can be an ethylene and/or α-olefin homopolymer preferably polyethylene or polypropylene, or, preferably, an inteφolymer of ethylene with at least one C3-C20 α-olefin and/or C4-C18 diolefins. Homogeneous copolymers of ethylene and one or more C3-C8 α-olefins are especially preferred.

Commercially available products to be employed as component (B) include ultralow density polyethylene (ULDPE) low density polyethylene (LDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE), high density polyethylene (HDPE), polyolefin plastomers. such as those marketed by The Dow Chemical Company under the AFFINITY™ tradename and polyethylene elastomers, such as those marketed under the ENGAGE™ tradename by Du Pont Dow Elastomers PLC. The molecular weight of the ethylene homopolymers and inteφolymers for use in the present invention is conveniently indicated using a melt flow measurement according to ASTM D-1238, Condition 190°C/2.16 kg (formerly known as "Condition (E)" and also known as I₂). Melt flow rate is inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt flow rate, although the relationship is not linear. The melt flow rate for the ethylene homopolymers and inteφolymers useful herein is generally from 0.1 grams/10 minutes (g/10 min) to 1000 g/10 min. preferably from 0.5 g/10 min to 200 g/10 min, and especially from 1 g/10 min to 100 g/10 min.

The C3 α-olefin homopolymers or copolymers employed as component (B) in the blends of the present invention are polypropylenes. The polypropylene is generally in the isotactic form of homopolymer polypropylene, although other forms of polypropylene can also be used (e.g., syndiotactic or atactic). Polypropylene impact copolymers (e.g., those wherein a secondary in-reactor copolymerization step reacting ethylene with the propylene is employed) and random copolymers (also reactor modified and usually containing 1.5-20 mol percent of ethylene or C4-C8 α-olefin copolymerized with the propylene), however, can also be used. A complete discussion of various polypropylene polymers is contained in Modern Plastics Encyclopedia/89, mid October 1988 Issue, Volume 65, Number 1 1, pp. 86-92. the entire disclosure of which is incoφorated herein by reference. The molecular weight of the polypropylene for use in the present invention is conveniently indicated using a melt flow measurement according to ASTM D-1238, Condition 230°C/2.16 kg (formerly known as "Condition (L)" and also known as I₂). Melt flow rate is inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt flow rate, although the relationship is not linear. The melt flow rate for the polypropylene useful herein is generally from 0.1 grams/10 minutes (g/10 min) to 200 g/10 min. preferably from 0.5 g/10 min to 100 g/10 min, and especially from 1 g/10 min to 50 g/10 min.

Thermoplastic olefins (TPOs) employed as component (B) are generally produced from propylene homo- or copolymers as described above, or blends of an elastomeric material such as ethylene/propylene rubber (EPM) or ethylene/propylene diene monomer teφolymer (EPDM) and a more rigid material such as isotactic polypropylene. Other materials or components can be added into the formulation depending upon the application, including oil, fillers, and cross-linking agents. In- reactor TPO's can also be used as blend components of the present invention. The third edition of the Kirk-Othmer Encyclopedia of Science and Technology defines engineering plastics as thermoplastic resins, neat or unreinforced or filled, which maintain dimensional stability and most mechanical properties above 100°C and below 0°C. The terms "engineering plastics'^' and "engineering thermoplastics", can be used interchangeably. Engineering thermoplastics which can be employed as blend component (B) include polyoxymethylene-based resins such as acetal; acrylic resins (for example poly(methylmethacrylate, PMMA)); polyamides (for example nylon-4,6, nylon-6, nylon 6,6, and higher nylons), polyimides, polyetherimides, cellulosics, polyesters, poly(arylate); aromatic polyesters (for example polybutylene terephthalate and polyethylene terephthalate, PEN and polycarbonate); liquid crystal polymers; blends, or alloys of the foregoing resins; and other resin types including for example rigid thermoplastic polyurethanes; high temperature polyolefins such as ethylene/norbornene copolymers, polycyclopentanes, its copolymers, and polymethylpentane and its copolymers.

Also included are the aromatic polyethers including, for example, the poly(phenylene ether) (PPE) thermoplastic engineering resins which are well known, commercially available materials produced by the oxidative coupling polymerization of alkyl substituted phenols. They are generally linear, amoφhous polymers having a glass transition temperature in the range of 190°C to 235°C. Preferred PPE materials include those represented by the formula:

wherein Q is the same or different alkyl group having from 1 to 4 carbon atoms and n is a whole integer of at least 100, preferably from 150 to 1200. Examples of preferred polymers are poly(2,6-dialkyl-l,4-phenylene ether) such as poly(2,6-dimethyl-l,4- phenylene ether), poly(2-methyl-6-ethyl-l,4-phenylene ether), poly(2-mefhyl-6-propyl- 1 ,4-phenylene ether), poly-(2,6-dipropyl-l,4-phenylene ether) and poly (2-ethyl-6- propyl-1 ,4-phenylene ether). A more preferred polymer is poly(2,6-dimethyl-l ,4- phenylene ether). These polymers are often sold as blends with polystyrene and high impact polystyrene, and other formulation components. Especially preferred engineering thermoplastics are acetal, polymethylmethacrylate, nylon-6, nylon 6,6, bisphenol A-poly(carbonate), poly(2,6- dimethyl-l,4-phenylene ether), and polybutylene terephthalate and polyethylene terephthalate,

Styrenic block copolymers which can be employed as blend component (B) are those having unsaturated rubber monomer units including, but not limited to, styrene- butadiene (SB), styrene-isoprene(SI), styrene-butadiene-styrene (SBS), styrene- isoprene-styrene (SIS), α-methylstyrene-butadiene-α-methylstyrene and α- methylstyrene-isoprene-α-methylstyrene.

The styrenic portion of the block copolymer is preferably a polymer or copolymer of styrene and its analogs and homologs including α-methylstyrene and ring-substituted styrenes, particularly ring-methylated styrenes. The preferred styrenics are styrene and α-methylstyrene, and styrene is particularly preferred.

Block copolymers with unsaturated rubber monomer units may comprise homopolymers of butadiene or isoprene or they may comprise copolymers of one or both of these two dienes with a minor amount of styrenic monomer. Preferred styrenic block copolymers which can be employed as Component (B) include at least one segment of a styrenic unit and at least one segment of an ethylene-butene or ethylene-propylene copolymer. Examples of such block copolymers with saturated rubber monomer units include styrene/ethylene-butene copolymers, styrene/ethylene-propylene copolymers, styrene/ethylene- butene/styrene (SEBS) copolymers, styrene/ethylene-propylene/styrene (SEPS) copolymers.

The elastomers which can be employed as blend component (B) include, but are not limited to, rubbers such as polyisoprene, polybutadiene, natural rubbers, ethylene/propylene rubbers, ethylene/propylene diene (EPDM) rubbers, silicone rubbers, styrene/butadiene rubbers and thermoplastic polyurethanes.

Vinyl or vinylidene halide homopolymers and copolymers which can be employed as blend component (B) are a group of resins which use as a building block the structure CH₂=CXY, where X is selected from the group consisting of F, Cl, Br, and I and Y is selected from the group consisting of F, Cl, Br, I and H.

The vinyl or vinylidene halide polymer component of the blends of the present invention include but are not limited to homopolymers and copolymers of vinyl or vinylidene halides with copolymerizable monomers such as ethylene and/or α-olefins including but not limited to ethylene, propylene, vinyl esters of organic acids containing 1 to 18 carbon atoms, for example vinyl acetate, vinyl stearate and so forth; vinyl chloride, vinylidene chloride, symmetrical dichloroethylene; acrylonitrile, methacrylonitrile; alkyl acrylate esters in which the alkyl group contains 1 to 8 carbon atoms, for example methyl acrylate and butyl acrylate; the corresponding alkyl methacrylate esters; dialkyl esters of dibasic organic acids in which the alkyl groups contain 1 - 8 carbon atoms, for example dibutyl fumarate, diethyl maleate, and so forth. Preferably the vinyl or vinylidene halide polymers are homopolymers or copolymers of vinyl chloride or vinylidene chloride. Poly (vinyl chloride) polymers (PVC) can be further classified into two main types by their degree of rigidity. These are "rigid" PVC and "flexible" PVC. Flexible PVC is distinguished from rigid PVC primarily by the presence of and amount of plasticizers in the resin. Flexible PVC typically has improved processability, lower tensile strength and higher elongation than rigid PVC.

Of the vinylidene chloride homopolymers and copolymers (PVDC), typically the copolymers with vinyl chloride, acrylates or nitriles are used commercially and are most preferred. The choice of the comonomer significantly affects the properties of the resulting polymer. Perhaps the most notable properties of the various PVDC's are their low permeability to gases and liquids, barrier properties; and chemical resistance.

Also included in the family of vinyl halide polymers for use as blend components of the present invention are the chlorinated derivatives of PVC typically prepared by post chlorination of the base resin and known as chlorinated PVC, (CPVC). Although CPVC is based on PVC and shares some of its characteristic properties, CPVC is a unique polymer having a much higher melt temperature range (410 - 450°C) and a higher glass transition temperature (239 - 275°F) than PVC. Additives such as antioxidants (e.g., hindered phenols such as, for example,

Irganox® 1010 a registered trademark of Ciba Geigy). phosphites (e.g., Irgafos® 168 a registered trademark of Ciba Geigy), U.V. stabilizers, cling additives (e.g., polyisobutylene), slip agents (such as erucamide and/or stearamide), antiblock additives, colorants, pigments, can also be included in either blend Component A and/or blend Component B or the overall blend compositions employed to prepare the fabricated articles of the present invention.

Processing aids, which are also referred to herein as plasticizers, can also be included in either blend Component A and/or blend Component B or the overall blend compositions employed to prepare the fabricated articles of the present invention, 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. Exemplary classes of oils useful as processing aids include white mineral oil (such as Kaydol™ oil (available from and a registered trademark of Witco), and Shellflex™ 371 naphthenic oil (available from and a registered trademark of Shell Oil Company). Another suitable oil is Tuflo™ oil (available from and a registered trademark of Lyondell).

Tackifiers, can also be included in either blend Component A and/or blend Component B or the overall blend compositions employed to prepare the fabricated articles of the present invention to alter the processing performance of the polymer and thus can extend the available application temperature window of the articles. A suitable tackifier may be selected on the basis of the criteria outlined by Hercules in J. Simons, Adhesives Age, "The HMDA Concept: A New Method for Selection of Resins", November 1996. This reference discusses the importance of the polarity and molecular weight of the resin in determining compatibility with the polymer. In the case of substantially random inteφolymers of at least one α-olefin and a vinyl aromatic monomer, preferred tackifiers will have some degree of aromatic character to promote compatibility, particularly in the case of substantially random inteφolymers having a high content of the vinyl aromatic monomer.

Tackifying resins can be obtained by the polymerization of petroleum and teφene feedstreams and from the derivatization of wood, gum, and tall oil rosin. Several classes of tackifiers include wood rosin, tall oil and tall oil derivatives, and cyclopentadiene derivatives, such as are described in United Kingdom patent application GB 2,032,439A. Other classes of tackifiers include aliphatic C5 resins, polyteφene resins, hydrogenated resins, mixed aliphatic-aromatic resins, rosin esters, natural and synthetic teφenes, teφene-phenolics, and hydrogenated rosin esters.

Also included as a potential component of the polymer compositions used in the present invention are various organic and inorganic fillers, the identity of which depends upon the type of application for which the elastic film is to be utilized. The fillers can also be included in either blend Component A and/or blend Component B or the overall blend compositions employed to prepare the fabricated articles of the present invention. 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. Fillers may suitably be employed in the range 1 -90 wt. percent. The blended polymer compositions used to prepare the fabricated articles of the present invention can be prepared by any convenient method, including dry blending the individual components and subsequently melt mixing or melt compounding in a Haake torque rheometer or by pre-melt mixing in a separate extruder or mill (e.g., a Banbury mixer), or by solution blending or by calendering. The blend components can also be dry blended, without melt blending, followed by part fabrication, either directly in the extruder, injection molding machine, film blowing equipment or mill used to make the finished article,

The fabricated articles of the present invention can be made using conventional melt processing operations. Whatever the melt processing operation used, in order to obtain the fabricated articles of the present invention, the melt processing operation should be performed under high shear rate conditions such that the critical shear rate is greater than 30, preferably from 40 to 30,000, even more preferably from 50 to 5,000 sec^"1.

For films, such operations include for example simple bubble extrusion (usually with a high blow-up ratio (BUR)), biaxial orientation processes (such as tenter frames or double bubble processes), simple cast/sheet extrusion, coextrusion, lamination, 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. Biaxial orientation film manufacturing processes such as described in the "double bubble" process of USP 3,456,044 (Pahlke), and the processes described in USP 4,352.849 (Mueller), USP 4,820,557 and 4,837,084 (both to Warren), USP 4,865,902 (Golike et al.), USP 4,927,708 (Herran et al.). USP 4.952,451 (Mueller), and USP 4,963,419 and 5,059,481 (both to Lustig et al.), can also be used to make the fabricated articles included in this invention. The fabricated articles of the present invention can also be rendered pervious or "breathable" by any method well known in the art including by 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.

Injection molding, thermoforming, extrusion coating, profile extrusion, and sheet extrusion melt processing operations are described, for example, in Plastics Materials and Processes, Seymour S. Schwartz and Sidney H. Goodman, Van Nostrand Reinhold Company, New York, 1982, pp. 527-563, pp. 632-647, and pp. 596-602. The fabricated articles of the present invention can be prepared by the primary extrusion process itself or by known 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.

During final part fabrication, the substantially random inteφolymers blend component (A) and/or the immiscible thermoplastic polymer components (B) may also be modified by various cross-linking processes. These include, but are not limited to peroxide-, silane-, sulfur-, radiation-, or azide-based cure systems. A full description of the various cross-linking technologies is described in copending U.S. Patent

Application No^'s 08/921,641 and 08/921,642 for crosslinking the substantially random inteφolymers blend component (A) both filed on August 27, 1997.

Dual cure systems, which use a combination of heat, moisture cure, and radiation steps, may be effectively employed. Dual cure systems are disclosed and claimed in U. S. Patent Application Serial No. 536,022, filed on September 29, 1995, in the names of K. L. Walton and S. V. Karande, incoφorated herein by reference. 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 polymer compositions used to prepare the fabricated articles of the present invention comprise (A) from 55 to 95. preferably from 65 to 92, more preferably from 70 to 90, even more preferably from 70 to 88 wt%, (based on the combined weights of Component A and the immiscible polymer Component B) of one or more substantially random inteφolymers of ethylene and /or one or more α-olefins and one or more vinyl or vinylidene aromatic monomers and/or one or more sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomers, and (B) from 5 to 45, preferable from 8 to 35, more preferably from 10 to 30, even more preferably from 12 to 30 wt. percent (based on the combined weights of Component A and the immiscible polymer Component B) of one or more thermoplastic polymer components immiscible with Component (A).

Component (B) comprises one or more of a styrenic homopolymer or copolymer, an ethylene and/or α-olefin homopolymer or inteφolymer, a thermoplastic olefin. an engineering thermoplastic, a styrenic block copolymer, an elastomer, or a vinyl or vinylidene halide polymer.

It has been discovered that the properties in the resultant fabricated articles are observed when these substantially random inteφolymers contain from 1 to 65 preferably from 2 to 50, more preferably from 5 to 50 mole percent of at least one vinyl or vinyl or vinylidene aromatic monomer and/or sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer and from 35 to 99, preferably from 50 to 98. more preferably from 50 to 95 mole percent of ethylene and/or at least one aliphatic α-olefin having from 3 to 20 carbon atoms. The melt index (I₂) of the substantially random inteφolymer used to prepare the fabricated articles of the present invention is greater than about 0.05, preferably of from 0.5 to 200, more preferably of from 0.5 to 100 g/10 min.

The molecular weight distribution (M_w/M_n) of the substantially random inteφolymer used to prepare the elastic films of the present invention is from 1.5 to 20, preferably of from 1.8 to 10. more preferably of from 2 to 5.

The density of the substantially random inteφolymer used to prepare the elastic films of the present invention is greater than about 0.900. preferably from 0.930 to 1.045, more preferably of from 0.930 to 1.040, most preferably of from 0.930 to 1.030 g/cm³. In one embodiment, the fabricated articles of the present invention demonstrate an enhancement in modulus when prepared under high shear rate processing operations as compared to samples prepared under low shear rate processing operations. Thus at temperatures at least 20°C in excess of the blend Tg (DSC), the elastic modulus of the article prepared under high shear rate processing operations is at least twice, preferably three times and more preferably ten times that of the article prepared under low shear rate processing operations.

The fabricated articles of the present invention include films, fibers, foams, injection molded articles, injection-blow molded articles and extruded profiles, with films and injection molded articles being the most preferred embodiments.

The following examples are illustrative of the invention, but are not to be construed as to limiting the scope thereof in any manner.

EXAMPLES

Test Methods

a) Melt Flow and Density Measurements

The molecular weight of the polymer compositions for use in the present invention was conveniently 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 was inversely proportional to the molecular weight of the polymer. Thus, the higher the molecular weight, the lower the melt index, although the relationship was not linear.

Also useful for indicating the molecular weight of the substantially random inteφolymers used in the present invention was the Gottfert melt index (G, cm³/ 10 min) which was obtained in a similar fashion as for melt index (I₂) using the ASTM D1238 procedure for automated plastometers, with the melt density set to 0.7632, the melt density of polyethylene at 190°C. The relationship of melt density to styrene content for ethylene-styrene inteφolymers was measured, as a function of total styrene content, at 190°C for a range of 29.8 percent to 81.8 percent by weight styrene. Atactic polystyrene levels in these samples was typically 10 percent or less. The influence of the atactic polystyrene was assumed to be minimal because of the low levels. Also, the melt density of atactic polystyrene and the melt densities of the samples with high total styrene were very similar. The method used to determine the melt density employed a Gottfert melt index machine with a melt density parameter set to 0.7632, and the collection of melt strands as a function of time while the 12 weight was in force. The weight and time for each melt strand was recorded and normalized to yield the mass in grams per 10 minutes. The instrument's calculated I2 melt index value was also recorded. The equation used to calculate the actual melt density is

^δ = δ₀₇₆₃₂ x l2 /l2 Gottfert

where δ _0.7632 ⁼ 0.7632 and 12 Gottfert = displayed melt index.

A linear least squares fit of calculated melt density versus total styrene content leads to an equation with a correlation coefficient of 0.91 for the following equation:

5 = 0.00299 x 5 + 0.723

where S = weight percentage of styrene in the polymer. The relationship of total styrene to melt density can be used to determine an actual melt index value, using these equations if the styrene content was known.

So for a polymer that was 73percent total styrene content with a measured melt flow (the "Gottfert number"), the calculation becomes:

5=0.00299*73 + 0.723 = 0.9412

where 0.9412/0.7632 = I₂/ G# (measured) = 1.23

b) Styrene Analyses Inteφolymer styrene content and atactic polystyrene concentration can be determined using proton nuclear magnetic resonance (Η N.M.R) or by ¹ C nuclear magnetic resonance.

All proton NMR samples were prepared in 1 , 1 , 2, 2-tetrachloroethane-d₂ (TCE-d₂). The resulting solutions were 1.6 - 3.2 percent polymer by weight. Melt index (I₂) was used as a guide for determining sample concentration. Thus when the I, was greater than 2 g/10 min, 40 mg of inteφolymer was used; with an I₂ between 1.5 and 2 g/10 min, 30 mg of inteφolymer was used; and when the I₂ was less than 1.5 g/10 min, 20 mg of inteφolymer was used. The inteφolymers were weighed directly into 5 mm sample tubes. A 0.75 mL aliquot of TCE-d₂ was added by syringe and the tube was capped with a tight-fitting polyethylene cap. The samples were heated in a water bath at 85°C to soften the inteφolymer. To provide mixing, the capped samples were occasionally brought to reflux using a heat gun.

Proton NMR spectra were accumulated on a Varian VXR 300 with the sample probe at 80°C, and referenced to the residual protons of TCE-d₂ at 5.99 ppm. The delay times were varied between 1 second, and data was collected in triplicate on each sample. The following instrumental conditions were used for analysis of the inteφolymer samples:

Varian VXR-300, standard Η: Sweep Width, 5000 Hz

Acquisition Time, 3.002 sec

Pulse Width, 8 μsec

Frequency, 300 MHz

Delay, 1 sec Transients, 16

The total analysis time per sample was about 10 minutes. Initially, a 'H NMR spectrum for a sample of the polystyrene, Styron™ 680 (available form the Dow Chemical Company, Midland, MI) was acquired with a delay time of one second. The protons were "labeled": b, branch; a, alpha; o, ortho; m, meta; p, para, as shown in Figure 2.

Figure 2.

Integrals were measured around the protons labeled in Figure 2; the A' designates aPS. Integral A₇ , (aromatic, around 7.1 ppm) was believed to be the three ortho/para protons; and integral A₆₆ (aromatic, around 6.6 ppm) the two meta protons. The two aliphatic protons labeled α resonate at 1.5 ppm; and the single proton labeled b was at 1.9 ppm. The aliphatic region was integrated from about 0.8 to 2.5 ppm and was referred to as A_a,. The theoretical ratio for A_{7 1}: A_{6 6}: A_a, was 3: 2: 3, or 1.5: 1 : 1.5, and correlated very well with the observed ratios for the Styron™ 680 sample for several delay times of 1 second. The ratio calculations used to check the integration and verify peak assignments were performed by dividing the appropriate integral by the integral A₆₆ Ratio A_r was A₇ , / A₆₆.

Region A₆₆ was assigned the value of 1. Ratio Al was integral A_a, / A₆₆. All spectra collected have the expected 1.5: 1 : 1.5 integration ratio of (o+p): m: (α+b). The ratio of aromatic to aliphatic protons was 5 to 3. An aliphatic ratio of 2 to 1 was predicted based on the protons labeled α and b respectively in Figure 2. This ratio was also observed when the two aliphatic peaks were integrated separately. For the ethylene/styrene inteφolymers, the Η NMR spectra using a delay time of one second, had integrals C₇ ,, C₆₆, and C_a, defined, such that the integration of the peak at 7.1 ppm included all the aromatic protons of the copolymer as well as the o &p protons of aPS. Likewise, integration of the aliphatic region C_al in the spectrum of the inteφolymers included aliphatic protons from both the aPS and the inteφolymer with no clear baseline resolved signal from either polymer. The integral of the peak at 6.6 ppm C_{66 was} resolved from the other aromatic signals and it was believed to be due solely to the aPS homopolymer (probably the meta protons). (The peak assignment for atactic polystyrene at 6.6 ppm (integral A₆₆) was made based upon comparison to the authentic sample Styron™ 680.) This was a reasonable assumption since, at very low levels of atactic polystyrene, only a very weak signal was observed here. Therefore, the phenyl protons of the copolymer must not contribute to this signal. With this assumption, integral A₆₆ becomes the basis for quantitatively determining the aPS content.

The following equations were then used to determine the degree of styrene incoφoration in the ethylene/styrene inteφolymer samples:

(C Phenyl) = C_{7 I} + A_{7 1} - ( 1.5 x A₆₆)

(C Aliphatic) = C_al - ( 1 5 x A₆₆) s_c = (C Phenyl) /5 e_c = (C Aliphatic - (3 x s_c)) /4

E = e_c / (e_c + s_c)

S_c = s_c / (e_c + s_c) and the following equations were used to calculate the mol percent ethylene and styrene in the inteφolymers.

and

where: s_c and e_c were styrene and ethylene proton fractions in the inteφolymer, respectively, and S_c and E were mole fractions of styrene monomer and ethylene monomer in the inteφolymer, respectively.

The weight percent of aPS in the inteφolymers was then determined by the following equation:

The total styrene content was also determined by quantitative Fourier Transform

Infrared spectroscopy (FTIR).

Preparation of ESI Inteφolymers Used in Examples and Comparative Experiments of Present Invention

1) Preparation of ESI 1 The inteφolymer was prepared in a 400 gallon (1514L) agitated semi- continuous batch reactor. The reaction mixture consisted of approximately 250 gallons (946L) of a solvent comprising a mixture of cyclohexane (85 wt%) & isopentane (15wt%), and styrene. Prior to addition, solvent, styrene and ethylene were purified to remove water and oxygen. The inhibitor in the styrene was also removed. Inerts were removed by purging the vessel with ethylene. The vessel was then pressure controlled to a set point with ethylene. Hydrogen was added to control molecular weight. Temperature in the vessel was controlled to set-point by varying the jacket water temperature on the vessel. Prior to polymerization, the vessel was heated to the desired run temperature and the catalyst components : Titanium: (N-l,l-dimethyl- ethyl)dimethyl(l-(l ,2,3,4,5-eta)-2,3.4.5-tetramethyl- 2,4-cyclopentadien-l- yl)silanaminato))(2-)N)-dimethyl, CAS# 135072-62-7. Tris(pentafluorophenyl)boron, CAS# 001109-15-5, Modified methylaluminoxane Type 3A, CAS# 146905-79-5, were flow controlled, on a mole ratio basis of 1/3/5 respectively, combined and added to the vessel. After starting, the polymerization was allowed to proceed with ethylene supplied to the reactor as required to maintain vessel pressure. Hydrogen was added to the headspace of the reactor to maintain a mole ratio with respect to the ethylene concentration. At the end of the run. the catalyst flow was stopped, ethylene was removed from the reactor, 1000 ppm of Irganox^,M 1010 anti-oxidant was then added to the solution and the polymer was isolated from the solution. The resulting polymer was isolated from solution by use of a devolatilizing extruder. The process conditions used to prepare ESI 1 were summarized in Table 1 and its properties were summarized in Table 2.

Table 2 Properties of ESI 1

Sample Melt Index Interpolymer Styrene atactic Mw MJMn Isolation I, (g/10 min) Content mol percent Polystyrene Number (Wt%) Wt% Method

ESI 1 2.6 18.3 (45.5) 10.3 126,200 1.89 Extruder

1) Preparation of ESI #'s 2-4

ESI #'s 2 - 4 were substantially random ethylene/styrene inteφolymers prepared using the constrained geometry catalyst, (t-butylamido)dimethyl(tetramethyl- cyclopenta-dienyl)silane-titanium (II) 1,3-pentadiene and the following co-catalyst and polymerization procedures.

Preparation of Cocatalyst B. (Bis(hydrogenated-tallowalkyl)methylamine Methylcyclohexane (1200 mL) was placed in a 2L cylindrical flask. While stirring, bis(hydrogenated-tallowalkyl)methylamine (ARMEEN^® M2HT, 104 g, ground to a granular form) was added to the flask and stirred until completely dissolved. Aqueous HC1 (1M, 200 mL) was added to the flask, and the mixture was stirred for 30 minutes. A white precipitate formed immediately. At the end of this time, LiB(C₆F₅)₄ • Et₂O • 3 LiCl (Mw = 887.3; 177.4 g) was added to the flask. The solution began to turn milky white. The flask was equipped with a 6" Vigreux column topped with a distillation apparatus and the mixture was heated (140 °C external wall temperature). A mixture of ether and methylcyclohexane was distilled from the flask. The two-phase solution was now only slightly hazy. The mixture was allowed to cool to room temperature, and the contents were placed in a 4 L separatory funnel. The aqueous layer was removed and discarded, and the organic layer was washed twice with H₂O and the aqueous layers again discarded. The H₂O saturated methylcyclohexane solutions were measured to contain 0.48 wt percent diethyl ether (Et₂O).

The solution (600 mL) was transferred into a 1 L flask, sparged thoroughly with nitrogen, and transferred into the drybox. The solution was passed through a column (1" diameter, 6" height) containing 13X molecular sieves. This reduced the level of Et₂O from 0.48 wt percent to 0.28 wt percent. The material was then stirred over fresh 13X sieves (20 g) for four hours. The Et₂O level was then measured to be 0.19 wt percent. The mixture was then stirred overnight, resulting in a further reduction in Et₂O level to approximately 40 ppm. The mixture was filtered using a funnel equipped with a glass frit having a pore size of 10- 15 μm to give a clear solution (the molecular sieves were rinsed with additional dry methylcyclohexane). The concentration was measured by gravimetric analysis yielding a value of 16.7 wt percent.

Polymerization ESI #'s 2 - 4 were prepared in a 6 gallon (22.7 L). oil jacketed, Autoclave continuously stirred tank reactor (CSTR). A magnetically coupled agitator with Lightning A-320 impellers provided the mixing. The reactor ran liquid full at 475 psig (3,275 kPa). Process flow was in at the bottom and out of the top. A heat transfer oil was circulated through the jacket of the reactor to remove some of the heat of reaction. At the exit of the reactor was a micromotion flow meter that measured flow and solution density. All lines on the exit of the reactor were traced with 50 psi (344.7 kPa) steam and insulated.

Toluene solvent was supplied to the reactor at 30 psig (207 kPa). The feed to the reactor was measured by a Micro-Motion mass flow meter. A variable speed diaphragm pump controlled the feed rate. At the discharge of the solvent pump, a side stream was taken to provide flush flows for the catalyst injection line (1 lb/hr (0.45 kg/hr)) and the reactor agitator (0.75 lb/hr ( 0.34 kg/ hr)). These flows were measured by differential pressure flow meters and controlled by manual adjustment of micro-flow needle valves. Uninhibited styrene monomer was supplied to the reactor at 30 psig (207 kpa).

The feed to the reactor was measured by a Micro-Motion mass flow meter. A variable speed diaphragm pump controlled the feed rate. The styrene stream was mixed with the remaining solvent stream. Ethylene was supplied to the reactor at 600 psig (4,137 kPa). The ethylene stream was measured by a Micro-Motion mass flow meter just prior to the Research valve controlling flow. A Brooks flow meter/controller was used to deliver hydrogen into the ethylene stream at the outlet of the ethylene control valve. The ethylene/hydrogen mixture combines with the solvent/styrene stream at ambient temperature. The temperature of the solvent/monomer as it enters the reactor was dropped to ~5 °C by an exchanger with -5°C glycol on the jacket. This stream entered the bottom of the reactor. The three component catalyst system and its solvent flush also entered the reactor at the bottom but through a different port than the monomer stream. Preparation of the catalyst components took place in an inert atmosphere glove box. The diluted components were put in nitrogen padded cylinders and charged to the catalyst run tanks in the process area. From these run tanks the catalyst was pressured up with piston pumps and the flow was measured with Micro-Motion mass flow meters. These streams combine with each other and the catalyst flush solvent just prior to entry through a single injection line into the reactor.

Polymerization was stopped with the addition of catalyst kill (water mixed with solvent) into the reactor product line after the micromotion flow meter measuring the solution density. Other polymer additives can be added with the catalyst kill. A static mixer in the line provided dispersion of the catalyst kill and additives in the reactor effluent stream. This stream next entered post reactor heaters that provide additional energy for the solvent removal flash. This flash occurred as the effluent exited the post reactor heater and the pressure was dropped from 475 psig (3,275 kPa) down to ~250mm of pressure absolute at the reactor pressure control valve. This flashed polymer entered a hot oil jacketed devolatilizer. Approximately 85 percent of the volatiles were removed from the polymer in the devolatilizer. The volatiles exited the top of the devolatilizer. The stream was condensed with a glycol jacketed exchanger and entered the suction of a vacuum pump and was discharged to a glycol jacket solvent and styrene/ethylene separation vessel. Solvent and styrene were removed from the bottom of the vessel and ethylene from the top. The ethylene stream was measured with a Micro-Motion mass flow meter and analyzed for composition. The measurement of vented ethylene plus a calculation of the dissolved gasses in the solvent/styrene stream were used to calculate the ethylene conversion. The polymer separated in the devolatilizer was pumped out with a gear pump to a ZSK-30 devolatilizing vacuum extruder. The dry polymer exits the extruder as a single strand. This strand was cooled as it was pulled through a water bath. The excess water was blown from the strand with air and the strand was chopped into pellets with a strand chopper.

The various catalysts, co-catalysts and process conditions used to prepare the various individual ethylene styrene inteφolymers (ESI #'s 2 - 4) were summarized in Table 3 and their properties were summarized in Table 4.

Table 3. Preparation Conditions for ESI #'s 2 - 4

*N/A = not available a Catalyst A was (t-butylamιdo)dιmethN (II) 1 3-pentadιene prepared as described in U S Patent # 5 556 928 Example 17 b Cocatalyst B was bis-hydrogenated tallow alkyl methΛ lammomum tetrakis (pentafluorophenyl)borate c a modified methylaluminoxane commercially available from Akzo Nobel as MMAO-3A (CAS# 146905-79-5) d SCCM w as standard cmVmin

Table 4. Properties of ESI #'s 2-4

Preparation of ESI 5

Preparation of Catalyst B;f 1 H-cvclopenta[l]phenanthrene-2-yl)dimethyl(t-butylamido)- silanetitanium 1 ,4-diphenylbutadiene)

1) Preparation of lithium lH-cyclopenta[l]phenanthrene-2-yl

To a 250 ml round bottom flask containing 1.42 g (0.00657 mole) of 1H- cyclopenta[l]phenanthrene and 120 ml of benzene was added dropwise, 4.2 ml of a 1.60 M solution of n-BuLi in mixed hexanes. The solution was allowed to stir overnight. The lithium salt was isolated by filtration, washing twice with 25 ml benzene and drying under vacuum. Isolated yield was 1.426 g (97.7 percent). 1H NMR analysis indicated the predominant isomer was substituted at the 2 position.

2) Preparation of ( 1 H-cyclopenta[l]phenanthrene-2-y l)dimethy lchlorosilane

To a 500 ml round bottom flask containing 4.16 g (0.0322 mole) of dimethyldichlorosilane (Me₂SiCl₂ ) and 250 ml of tetrahydrofuran (THF) was added dropwise a solution of 1.45 g (0.0064 mole) of lithium lH-cyclopenta[l]phenanthrene- 2-yl in THF. The solution was stirred for approximately 16 hours, after which the solvent was removed under reduced pressure, leaving an oily solid which was extracted with toluene, filtered through diatomaceous earth filter aid (Celite™). washed twice with toluene and dried under reduced pressure. Isolated yield was 1.98 g (99.5 percent).

Preparation of ( 1 H-cyclopenta[l]phenanthrene-2-yl)dimethyl(t-butylamino)silane

To a 500 ml round bottom flask containing 1.98 g (0.0064 mole) of (1H- cyclopenta[l]phenanthrene-2-yl)dimethylchlorosilane and 250 ml of hexane was added 2.00 ml (0.0160 mole) of t-butylamine. The reaction mixture was allowed to stir for several days, then filtered using diatomaceous earth filter aid (Celite™), washed twice with hexane. The product was isolated by removing residual solvent under reduced pressure. The isolated yield was 1.98 g (88.9 percent).

4. Preparation of dilithio (lH-cyclopenta[l]phenanthrene-2-yl)dimethyl(t- butylamido)silane

To a 250 ml round bottom flask containing 1.03 g (0.0030 mole) of (1H- cyclopenta[l]phenanthrene-2-yl)dimethyl(t-butylamino)silane) and 120 ml of benzene was added dropwise 3.90 ml of a solution of 1.6 M n-BuLi in mixed hexanes. The reaction mixture was stirred for approximately 16 hours. The product was isolated by filtration, washed twice with benzene and dried under reduced pressure. Isolated yield was 1.08 g (100 percent).

5. Preparation of (lH-cyclopenta[l]phenanthrene-2-yl)dimethyl(t- butylamido)silanetitanium dichloride

To a 250 ml round bottom flask containing 1.17 g (0.0030 mole) of

TiCl3»3THF and about 120 ml of THF was added at a fast drip rate about 50 ml of a

THF solution of 1.08 g of dilithio (lH-cyclopenta[l]phenanthrene-2-yl)dimethyl(t- butylamido)silane. The mixture was stirred at about 20 °C for 1.5 h at which time 0.55 gm (0.002 mole) of solid PbCl2 was added. After stirring for an additional 1.5 h the THF was removed under vacuum and the reside was extracted with toluene, filtered and dried under reduced pressure to give an orange solid. Yield was 1.31 g (93.5 percent).

6. Preparation of (lH-cyclopenta[l]phenanthrene-2-yl)dimethyl(t- butylamido)silanetitanium 1 ,4-diphenylbutadiene

To a slurry of (lH-cyclopenta[l]phenanthrene-2-yl)dimethyl(t- butylamido)silanetitanium dichloride (3.48 g, 0.0075 mole) and 1.551 gm (0.0075 mole) of 1 ,4-diphenyllbutadiene in about 80 ml of toluene at 70 °C was add 9.9 ml of a 1.6 M solution of n-BuLi (0.0150 mole). The solution immediately darkened. The temperature was increased to bring the mixture to reflux and the mixture was maintained at that temperature for 2 hrs. The mixture was cooled to -20 °C and the volatiles were removed under reduced pressure. The residue was slurried in 60 ml of mixed hexanes at about 20 °C for approximately 16 hours. The mixture was cooled to - 25 °C for 1 h. The solids were collected on a glass frit by vacuum filtration and dried under reduced pressure. The dried solid was placed in a glass fiber thimble and solid extracted continuously with hexanes using a soxhlet extractor. After 6 h a crystalline solid was observed in the boiling pot. The mixture was cooled to about -20 °C, isolated by filtration from the cold mixture and dried under reduced pressure to give 1.62 g of a dark crystalline solid. The filtrate was discarded. The solids in the extractor were stirred and the extraction continued with an additional quantity of mixed hexanes to give an additional 0.46 gm of the desired product as a dark crystalline solid.

Polymerization for ESI 5 ESI 5 was prepared in a continuously operating loop reactor (36.8 gal. 139 L).

An Ingersoll-Dresser twin screw pump provided the mixing. The reactor ran liquid full at 475 psig (3,275 kPa) with a residence time of approximately 25 minutes. Raw materials and catalyst/cocatalyst flows were fed into the suction of the twin screw pump through injectors and Kenics static mixers. The twin screw pump discharged into a 2" diameter line which supplied two Chemineer-Kenics 10-68 Type BEM Multi- Tube heat exchangers in series. The tubes of these exchangers contained twisted tapes to increase heat transfer. Upon exiting the last exchanger, loop flow returned through the injectors and static mixers to the suction of the pump. Heat transfer oil was circulated through the exchangers' jacket to control the loop temperature probe located just prior to the first exchanger. The exit stream of the loop reactor was taken off between the two exchangers. The flow and solution density of the exit stream was measured by a MicroMotion.

Solvent feed to the reactor was supplied by two different sources. A fresh stream of toluene from an 8480-S-E Pulsafeeder diaphragm pump with rates measured by a MicroMotion flowmeter was used to provide flush flow for the reactor seals (20 lb/hr (9.1 kg/hr). Recycle solvent was mixed with uninhibited styrene monomer on the suction side of five 8480-5-E Pulsafeeder diaphragm pumps in parallel. These five Pulsafeeder pumps supplied solvent and styrene to the reactor at 650 psig (4,583 kPa). Fresh styrene flow was measured by a MicroMotion flowmeter, and total recycle solvent/styrene flow was measured by a separate MicroMotion flowmeter. Ethylene was supplied to the reactor at 687 psig (4,838 kPa). The ethylene stream was measured by a Micro-Motion mass flowmeter. A Brooks flowmeter/controller was used to deliver hydrogen into the ethylene stream at the outlet of the ethylene control valve. The ethylene/hydrogen mixture combined with the solvent/styrene stream at ambient temperature. The temperature of the entire feed stream as it entered the reactor loop was lowered to 2°C by an exchanger with -10°C glycol on the jacket. Preparation of the three catalyst components took place in three separate tanks: fresh solvent and concentrated catalyst/cocatalyst premix were added and mixed into their respective run tanks and fed into the reactor via variable speed 680-S-AEN7 Pulsafeeder diaphragm pumps. As previously explained, the three component catalyst system entered the reactor loop through an injector and static mixer into the suction side of the twin screw pump. The raw material feed stream was also fed into the reactor loop through an injector and static mixer downstream of the catalyst injection point but upstream of the twin screw pump suction. Polymerization was stopped with the addition of catalyst kill (water mixed with solvent) into the reactor product line after the Micro Motion flowmeter measuring the solution density. A static mixer in the line provided dispersion of the catalyst kill and additives in the reactor effluent stream. This stream next entered post reactor heaters that provided additional energy for the solvent removal flash. This flash occurred as the effluent exited the post reactor heater and the pressure was dropped from 475 psig (3,275 kPa) down to 450 mmHg (60 kPa) of absolute pressure at the reactor pressure control valve.

This flashed polymer entered the first of two hot oil jacketed devolatilizers. The volatiles flashing from the first devolatizer were condensed with a glycol jacketed exchanger, passed through the suction of a vacuum pump, and were discharged to the solvent and styrene/ethylene separation vessel. Solvent and styrene were removed from the bottom of this vessel as recycle solvent while ethylene exhausted from the top. The ethylene stream was measured with a MicroMotion mass flowmeter. The measurement of vented ethylene plus a calculation of the dissolved gases in the solvent/styrene stream were used to calculate the ethylene conversion. The polymer and remaining solvent separated in the devolatilizer was pumped with a gear pump to a second devolatizer. The pressure in the second devolatizer was operated at 5 mm Hg (0.7 kPa) absolute pressure to flash the remaining solvent. This solvent was condensed in a glycol heat exchanger, pumped through another vacuum pump, and exported to a waste tank for disposal. The dry polymer (< 1000 ppm total volatiles) was pumped with a gear pump to an underwater pelletizer with 6-hole die, pelletized, spin-dried, and collected in 1000 lb boxes.

The various catalysts, co-catalysts and process conditions used to prepare ESI 5 were summarized in Table 5 and its properties were summarized in Table 6.

Table 5. Preparation Conditions for ESI 5

*N/A = not available a Catah st A was .(lH-cyclopenta[l]phenanthrene-2-yl)dιmethy!(t-but\ lamιdo)-sιlanetιtanιum 1.4- diphe lbutadiene) b CocataK st B was l)borane. (C AS# 001 109- 15-5). c a modified methylaluminoxane commercialK available from Akzo Nobel as MMAO-3A (CAS# 146905-79-5)

Table 6. Properties of ESI 5

Test parts and characterization data for the inteφolymers and their blends were generated according to the following procedures:

Differential Scanning Calorimetry (DSC)

A Dupont DSC-2920 was used to measure the thermal transition temperatures and heat of transition for the inteφolymers. In order to eliminate previous thermal history, samples were first heated to 200°C. Heating and cooling curves were recorded at 10°C/min. Melting (from second heat) and crystallization temperatures were recorded from the peak temperatures of the endotherm and exotherm, respectively.

Compression Molding Samples were melted at 190°C for 3 minutes and compression molded at 190°C under 20,000 lb (9,072 kg) of pressure for another 2 minutes. Subsequently, the molten materials were quenched in a press equilibrated at room temperature.

Example 1

A sample of ESI # 1 (10.3 wt percent atactic polystyrene) was extruded from a

Goettfert Rheograph 2003 capillary rheometer through a 1mm diameter, 20 L/D (length to diameter) capillary at 190 °C. A 1000 bar pressure transducer was used to accurately measure the pressure drop and hence determine the shear stress. Shear rates of 0.46, 4.5, 46. 100, 214, 464, 1000, and 2150 s^"1 were used. During extrusion at each shear rate, the extrudate was collected and saved for future testing. The corresponding viscosities and shear stresses corresponding to each of the shear rates discussed previously were shown Table 7:

Table 7. Effect of Processing Shear Rate

on the Viscosity of ESI 1

A portion of each of these strands was then used on a Rheometrics Solids Analyzer II. A monofilament fixture was used for all testing. The diameter of the sample was accurately determined with a micrometer as was the length of the sample. Approximate diameters were 1.3 mm and approximate lengths were 26 mm. A temperature sweep was performed at a frequency of 10 rad/s from -90 C to either 200 C, or the temperature at which the sample became so molten and thus the modulus became so low that the forces were unmeasurable. This dynamic temperature test was run in 5 degree steps with a 30 second soak time at each test temperature. An initial strain of 0.005percent was used. Autotension was used with the static force tracking dynamic force option in tension. The initial static force was 120 gm with 2 gm of autotension sensitivity. The static force was stipulated to be greater than the dynamic force by 9percent with a minimum static force of 2 gm. Autostrain was used with a maximum applied strain of 2%, a minimum allowed force of 2 gm, a maximum allowed force of 200 gm, and a 20 percent strain adjustment. Plots of the storage modulus of each of these extrudates showed an increase in storage modulus with increasing shear rate of extrusion. This increase was evident from 4.6 s^"1 to 46 s^"'. Samples from 100-464 s^"1 showed similar behavior and high moduli. This was indicative of a significant change in microstructure of these resins upon extrusion as shown in Figure 1 :

Examples 2 - 4

Samples of ESI #'s 2 -4 were fabricated into blown film and compression molded plaques as described below. The results of the Tg and elastic modulus testing as a function of temperature were summarized in Table 9. Film Preparation

Films were prepared by standard methods using a 1.25 inch Killion extruder extruder with a 12/6/6 24:1 L/D screw operating at a melt temperature of about 415 °F with a 3" in diameter die and a 40 mil die gap. In all cases the shear rates used to fabricate the films were in the range of 50 - 100 sec^"'. The extrusion conditions for the various samples were summarized in Table 8.

Table 8. Film Fabrication Conditions of Films of

Example #'s 2 ■ -4

Ex 1 Ex 2 Ex 3

Zone#l set Pt. °F (°C) 260 270 250

(127) (132) (121)

Zone #2 set Pt . °F (°C) 370 370 325

(188) (188) (163)

Zone #3 set Pt . °F (°C) 380 380 351

(193) (193) (177)

Large flange set pt . °F (°C) 380 380 384

(193) (193) (196)

Adapter set pt °F (°C) 380 380 370

(193) (193) (188)

Die 1 set pt . °F (°C) 380 385 376

(193) (196) (191)

Die 2 set pt . °F (°C) 380 385 374

(193) (196) (190)

Melt temp . °F (°C) 417 412 418

(214) (211) (214)

Extruder Press, psig 3170 3590 2730

(kPa) (21.854) (24,749) (18.821)

Screw Speed rpm 501 501 501

Extruder amps 167 18 16 ip Roll Speed, ftmin (m/s) 166 166 26

(008) (008) (013) Table 9 Change in Modulus( 10⁸G) Between Film and Compression Molded Plaques as an Indication of Laminar Morphology of Examples #'s 1 - 3

in o

Example 5

A blend of 70 weight percent of a substantially random inteφolymer (ESI # 5) and 30 weight percent of a styrene acrylonitrile copolymer was fabricated into cast film and a compression molded plaque. Pellets of each blend component were tumble blended, and poured into the hopper of a 2 inch diameter, Killion extruder with a 30:1 L:D ratio screw. Fabricated sheet was formed by extrusion through -a 14 inch wide, coat hanger type flat die with a 15 mil (.015 in.) die gap. Film was collected on a polished roll stack and haul-off unit at a rate of approximately 10 lb./hr. Shear rate was estimated to be 100-200 /sec. The results of the Tg and elastic modulus testing as a function of temperature were summarized in Table 10.

Table 10. Change in Modulus(10^"9E') Between Film and Compression Molded

Plaques as an Indication of Laminar Moφhology of Example # 5

Examples 2-5 show that the individual blend components were mutually immiscible as demonstrated by the presence of a discernible Tg of the ethylene styrene inteφolymer component under high and low shear rate melt processing conditions. The Examples also demonstrate the enhancement in modulus for fabricated articles prepared under high shear rate conditions (i.e. the films in this case) as compared to samples prepared under low shear rate conditions (i.e. the plaques in this case). All Examples meet the criterion that, at temperatures at least 20°C in excess of the blend Tg (DSC), the Elastic modulus of the article prepared under high shear rate conditions was at least twice, preferably three times and more preferably ten times that of the article prepared under low shear rate conditions.

Claims

1. A fabricated article which is made by a high critical shear rate melt processing operation and comprising a blend of at least two polymers which are mutually immiscible, said blend comprising from 55 to 95 wt percent (based on the combined weights of Components A and B) of

(A) at least one substantially random inteφolymer, which comprises; ( 1 ) polymer units derived from;

(i) at least one vinyl or vinylidene aromatic monomer, or (ii) at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, or (iii) a combination of at least one aromatic vinyl or vinylidene monomer and at least one aliphatic or cycloaliphatic vinyl or vinylidene monomer, and (2) polymer units derived from ethylene and/or at least one C_3.20 α-olefin; and,

(B) at least one thermoplastic polymer which is immiscible with Component (A) and is present in an amount of from 5 to 45 wt percent (based on the combined weights of Components A and B); and wherein (C) said high critical shear rate is greater than about 30 sec^"1.

2. The fabricated article of Claim 1 wherein;

(I) said substantially random inteφolymer, Component (A), is present in an amount from 65 to 92 wt percent (based on the combined weights of Components A and B) and has an I₂ of greater than about 0.05 g/10 min and an M_u/M_n of 1.5 to 20, and comprises;

(1) from about 1 to about 65 mol percent of polymer units derived from; (i) said vinyl or vinylidene aromatic monomer represented by the following formula; Ar I (CH₂)_n

R¹ — C = C(R )₂ wherein R¹ is selected from the group of radicals consisting of hydrogen and alkyl radicals containing three carbons or less, each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, and Ar is a phenyl group or a phenyl group substituted with from 1 to 5 substituents selected from the group consisting of halo, C - alkyl, and C,.₄-haloalkyl; or (ii) said aliphatic or cycloaliphatic vinyl or vinylidene monomer is represented by the following general formula;

A'

I

Rⁱ — c = C(R²)₂ wherein A' 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 4 carbon atoms, each R² is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, or alternatively R¹ and A¹ together form a ring system; and (2) from 35 to 99 mol percent of polymer units derived from ethylene and/or said α-olefin which comprises at least one of propylene, 4- methyl- 1 -pentene, butene-1, hexene-1 or octene-1; and (II) Component (B) is present in amount from about 8 to about 35 wt percent (based on the combined weights of Components A and B) and comprises one or more selected from: a) a styrenic homopolymer or copolymer b) an ethylene and/or α-olefin homopolymer or inteφolymer c) a thermoplastic olefin, d) an engineering thermoplastic e) a styrenic block copolymer f) an elastomer, or g) a vinyl or vinylidene halide polymer; and wherein

(III) said high critical shear rate is from 40 to 30,000 sec^"1. -

3. The fabricated article of Claim 1 wherein;

(I) said substantially random inteφolymer Component (A) is present in an amount of 70 to 92 wt percent (based on the combined weights of

Components A and B) and has an L of 0.5 to 200 g/10 min and an M_u/M_n of 1.8 to 10; and comprises

(1) from 2 to 50 mol percent of polymer units derived from; i) said vinyl or vinylidene aromatic monomer which comprises styrene, α-methyl styrene, ortho-. meta-, and para- methylstyrene, and the ring halogenated styrenes, or ii) said aliphatic or cycloaliphatic vinyl or vinylidene monomers which comprises 5-ethylidene-2-norbornene or 1 -vinylcyclo-hexene, 3-vinylcyclo-hexene, and 4- vinylcyclohexene;

(2) from 50 to 98 mol percent of polymer units derived from said α- olefin. which comprises ethylene, or ethylene and at least one of propylene, 4-methyl-l-pentene, butene-1. hexene-1 or octene-1 ; or

II) Component (B) is present in amount from 8 to 30 wt percent (based on the combined weights of Components A and B) and comprises one or more polymers comprising: a) polystyrene, high impact polystyrene, styrene/acrylonitrile (SAN) copolymers, styrene/maleic anhydride copolymers (SMA), styrene/methyl methacrylate copolymers (S-MMA), acrylonitrile/butadiene/styrene copolymer (ABS), syndiotactic polystyrene, isotactic polystyrene. b) ultralow density polyethylene (ULDPE) low density polyethylene (LDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE), high density polyethylene (HDPE), polyolefin plastomer, polyethylene elastomer, a substantially linear ethylene/α-olefin inteφolymer, a heterogeneous ethylene/C₃-C₈ α- olefin inteφolymer, propylene/C₄-C₈ α-olefin inteφolymer isotactic polypropylene, ethylene vinyl acetate (EVA), ethylene vinyl alcohol (EVOH); c) thermoplastic polyolefins; d) poly(methylmethacrylate),nylon-6, nylon-6.6, poly(acetal); rigid thermoplastic polyurethane, bisphenol A-poly(carbonate), polyethylene terephthalate, polybutylene terephthalate; e) a styrene/ethylene-butene copolymer, a styrene/ethylene- propylene copolymer, a styrene/ethylene-butene/styrene (SEBS) copolymer, a styrene/ethylene-propylene/styrene (SEPS) copolymer, f) polyisoprene. polybutadiene, natural rubbers, ethylene/propylene rubbers, ethylene/propylene diene (EPDM) rubbers, styrene/butadiene rubbers, thermoplastic polyurethanes, g) homopolymers or copolymers of vinyl chloride or vinylidene chloride; and wherein

(III) said high critical shear rate is from 50 to 5,000 sec^"1.

4. The fabricated article of Claim 1 wherein;

(I) said substantially random inteφolymer. Component (A), is present in an amount from 70 to 92 wt percent (based on the combined weights of Components A and B) and has an I₂ of 0.5 to 100 g/10 min and an M_w/M_n from 2 to 5; and comprises

(1) from 5 to 50 mol percent of polymer units derived from; i) said vinyl or vinylidene aromatic monomer which comprises styrene, α-methyl styrene, ortho-, meta-, and para- methyl styrene, or ii) said aliphatic or cycloaliphatic vinyl or vinylidene monomers which comprises 5-ethylidene-2-norbornene or

1-vinylcyclo-hexene, 3-vinylcyclo-hexene, and 4- vinylcyclohexene; (2) from 50 to 95 mol percent of polymer units derived from said α- olefin, which comprises ethylene, or ethylene and at least one of propylene, 4-methyl- 1 -pentene, butene- 1 , hexene- 1 or octene- 1 ; or

(II) Component (B) is present in amount from 8 to 30 wt percent (based on the combined weights of Components A and B) and comprises one or more polymers comprising: a) polystyrene, high impact polystyrene, syndiotactic polystyrene, isotactic polystyrene, and styrene/acrylonitrile (SAN) copolymers, b) ultralow density polyethylene (ULDPE) low density polyethylene (LDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE), high density polyethylene (HDPE), a substantially linear ethylene/α-olefm inteφolymer, or a heterogeneous ethylene/C₃-C₈ α-olefin inteφolymer; c) an ethylene/propylene rubber (EPM), ethylene/propylene diene monomer teφolymer (EPDM) , isotactic polypropylene; d) poly(methylmethacrylate), poly(amide), poly(carbonate); e) a styrene/ethylene-butene copolymer, a styrene/ethylene- propylene copolymer, a styrene/ethylene-butene/styrene (SEBS) copolymer, a styrene/ethylene-propylene/styrene (SEPS) copolymer, f) ethylene/propylene rubbers, ethylene/propylene diene (EPDM) rubbers, styrene/butadiene rubbers, thermoplastic polyurethanes, g) homopolymers or copolymers of vinyl chloride or vinylidene chloride.

5. The fabricated article of Claim 4 wherein Component (A)l is styrene, Component (A)2 is ethylene, and Component (B) is either polystyrene or high impact polystyrene.

6. The fabricated article of Claim 4 wherein Component (A)l is styrene, Component (A)2 is ethylene, and Component (B) has a melt index (I₂) of from 0.1 to 100 g/10 min, a density of from 0.855 to 0.975 g/cm³ and comprises one or more of, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE), high density polyethylene (HDPE).

7. The fabricated article of Claim 4 wherein Component (A)l is styrene; and Component (A)2 is ethylene and at least one of propylene, 4-methyl-l-pentene, butene-1, hexene-1 or octene-1; and Component (B) is polystyrene.

8. The fabricated article of Claim 4 wherein Component (A)l is styrene; and

Component (A)2 is ethylene and at least one of propylene, 4-methyl-l-pentene, butene-1, hexene-1 or octene-1; and Component (B) has a melt index (I₂) of from 0.1 to 100 g/10 min, a density of from 0.855 to 0.975 g/cm^J and comprises one or more of. low density polyethylene (LDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE), high density polyethylene

(HDPE).

9. The fabricated article of Claim 1 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

10. . The fabricated article of Claim 2 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

1 1. The fabricated article of Claim 3 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

12. The fabricated article of Claim 4 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

13. The fabricated article of Claim 5 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

14. The fabricated article of Claim 6 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

15. The fabricated article of Claim 7 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

16. The fabricated article of Claim 8 in the form of a film, sheet or as a component of a multilayered structure resulting from calendering, blowing or (co)extrusion melt processing operations .

17. The fabricated article of Claim 1 in the form of a foam or fiber.

18. The fabricated article of Claim 2 in the form of a foam or fiber.

19. The fabricated article of Claim 3 in the form of a foam or fiber.

20. The fabricated article of Claim 4 in the form of a foam or fiber.

21. The fabricated article of Claim 5 in the form of a foam or fiber.

22. The fabricated article of Claim 6 in the form of a foam or fiber.

23. The fabricated article of Claim 7 in the form of a foam or fiber.

24. The fabricated article of Claim 8 in the form of a foam or fiber.

25. The fabricated article of Claim 1 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

26. The fabricated article of Claim 2 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

27. The fabricated article of Claim 3 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

28. The fabricated article of Claim 4 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

29. The fabricated article of Claim 5 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

30. The fabricated article of Claim 6 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

31. The fabricated article of Claim 7 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

32. The fabricated article of Claim 8 in the form of a molded part resulting from injection molding, profile extrusion or blow molding melt processing operations.

33. A fabricated article of Claim 5 wherein said Component B is atactic polystyrene formed by homopolymerization as an integral part of the manufacture of the substantially random ethylene styrene inteφolymer.

34. A fabricated article of Claim 7 wherein said Component B is atactic polystyrene formed by homopolymerization as an integral part of the manufacture of the substantially random ethylene styrene inteφolymer.

35. The fabricated article of Claim 1 wherein either Component A and/or Component B is crosslinked during, or subsequent to, said melt processing operation.

36. A fabricated article of Claim 1 wherein at temperatures at least 20°C in excess of the Tg (DSC) of said blend, the elastic modulus of the article prepared under said high shear rate melt processing operation is at least about twice that of the article prepared under low shear rate conditions.

37. A fabricated article of Claim 1 wherein at temperatures at least 20°C in excess of the Tg (DSC) of said blend, the elastic modulus of the article prepared under said high shear rate melt processing operation is greater than about three times that of the article prepared under low shear rate conditions.

38. A fabricated article of Claim 1 wherein at temperatures at least 20°C in excess of the Tg (DSC) of said blend, the elastic modulus of the article prepared under said high shear rate melt processing operation is greater than about ten times that of the article prepared under low shear rate conditions.

39. The fabricated article of Claim 6 in the form of a paintable injection molded toy.

40. The fabricated article of Claim 8 in the form of a paintable injection molded toy.