AND PROPYLENE POLYMERS INVENTORS: Paul E. Rollin, Jr., John W.M. Roberts, William M. Ferry, Srinivasa Syamal S. Tallury, and Karen K. Chui.

PRIORITY

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 62/732,082, filed September 17, 2018, and European Patent Application No. 18199608.3 which was filed October 10, 2018, the disclosures of which are incorporated herein by reference in their entireties.

FIELD

[0002] The present disclosure provides nonwoven compositions containing propylene- based elastomers and propylene polymers and to articles made therefrom.

BACKGROUND

[0003] Polypropylene resins are useful in a variety of applications, including the manufacture of nonwoven fabrics, films, fibers, and injection molded articles. While, polypropylene resins can be used to produce nonwoven fabrics that have an aesthetically pleasing feel, such as being soft to the touch, in general, such polypropylene resins have little to no tensile strength. Alternatively, if the polypropylene resins are used to produce nonwoven fabrics that have a respectable tensile strength, then the nonwoven fabrics lack a desirable softness.

[0004] Therefore, there is a need for a nonwoven fabric containing a polypropylene resin and having desirable softness and relatively high tensile strength.

SUMMARY

[0005] The present disclosure provides polymeric compositions that contain one or more propylene polymers (PPs) and one or more propylene-based elastomers (PBEs). The polymeric compositions with the blended mixture of the PP and the PBE are useful as nonwoven fabrics, films, fibers, composites, and injection molded articles. The polymeric composition contains a blend of the PP and the PBE in predetermined ratios to provide exceptional softness and non-rubbery feel to the material while maintaining a high tensile strength. [0006] In one or more embodiments, the composition comprises (or consists of, or consists essentially of) 50 wt% to 98 wt% of the PP and 2 wt% to 50 wt% of the PBE, based on the weight of the composition. The PP has a melt flow rate (MFR) of 10 decigrams per minute (dg/min) to 30 dg/min (at 230°C), and the PBE contains propylene-derived units and 5 wt% to 30 wt% of a-olefm-derived units and has a melting temperature of less than l20°C and a heat of fusion of less than 75 J/g.

[0007] In some embodiments, a composition comprises (or consists of, or consists essentially of) 50 wt% to 98 wt% of the PP and 2 wt% to 50 wt% of the PBE, based on the weight of the composition. The composition has a peak load in a cross direction of greater than 0.85 centimeters per gram per square meter (N/5cm/gsm) and a peak load in a machine direction of greater than 1.5 N/5cm/gsm. The PP has an MFR (at 230°C) of 10 dg/min to 30 dg/min, and the PBE contains propylene-derived units and 5 wt% to 30 wt% of a-olefm- derived units and has a melting temperature of less than l20°C and a heat of fusion of less than 75 J/g.

[0008] In other embodiments, a composition comprises (or consists of, or consists essentially of) 60 wt% to 95 wt% of the PP and 5 wt% to 40 wt% of the PBE, and 0.5 wt% to 5 wt% of a slip additive, based on the weight of the composition. The composition has a coefficient of static friction of greater than 0.24. The PP has an MFR (at 230°C) of 10 dg/min to 30 dg/min and the PBE contains propylene-derived units and 5 wt% to 30 wt% of a-olefm- derived units and has a melting temperature of less than l20°C and a heat of fusion of less than 75 J/g.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] So that the manner in which the above recited features of the disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to implementations, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical implementations of this disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective implementations.

[0010] FIG. 1 is a graph depicting peak load strengths in the cross direction for samples of polymeric compositions produced by processes described and discussed herein, according to one or more embodiments. [0011] FIG. 2 is a graph depicting peak load strengths in the machine direction for samples of polymeric compositions produced by processes described and discussed herein, according to one or more embodiments.

[0012] FIG. 3 is a graph depicting total hand softness for samples of polymeric compositions produced by processes described and discussed herein, according to one or more embodiments.

[0013] FIG. 4 is a graph depicting coefficient of static friction for samples of polymeric compositions produced by processes described and discussed herein, according to one or more embodiments.

[0014] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the FIGs. It is contemplated that elements and features of one implementation may be beneficially incorporated in other implementations without further recitation.

DFTA11 FD DESCRIPTION

[0015] The present disclosure provides polymeric compositions that contain one or more propylene polymers (PPs) and one or more propylene-based elastomers (PBEs). The polymeric compositions with the blended mixture of the PP and the PBE are useful as nonwoven fabrics, films, fibers, composites, and injection molded articles. The polymeric composition contains a blend of the PP and the PBE in predetermined ratios to provide exceptional softness while maintaining a high tensile strength.

[0016] As used herein, the term“copolymer” is meant to include polymers having two or more monomers, optionally, with other monomers, and may refer to interpolymers, terpolymers, etc. The term“polymer” as used herein includes, but is not limited to, homopolymers, copolymers, terpolymers, etc., and alloys and blends thereof. The term “polymer” as used herein also includes impact, block, graft, random, and alternating copolymers. The term“polymer” shall further include all possible geometrical configurations unless otherwise specifically stated. Such configurations may include isotactic, syndiotactic and random symmetries. The term“elastomer” shall mean any polymer exhibiting some degree of elasticity, where elasticity is the ability of a material that has been deformed by a force (such as by stretching) to return at least partially to its original dimensions once the force has been removed.

[0017] The term“monomer” or“comonomer,” as used herein, can refer to the monomer used to form the polymer, e.g., the unreacted chemical compound in the form prior to polymerization, and can also refer to the monomer after it has been incorporated into the polymer, also referred to herein as a“[monomer] -derived unit”.

[0018] “Polypropylene,” as used herein, includes homopolymers and copolymers of propylene or mixtures thereof. Products that include one or more propylene monomers polymerized with one or more additional monomers may be more commonly known as random copolymers (RCP) or impact copolymers (ICP). Impact copolymers may also be known in the art as heterophasic copolymers. “Propylene-based,” as used herein, is meant to include any polymer containing propylene, either alone or in combination with one or more comonomers, in which propylene is the major component (e.g., greater than 50 wt% propylene).

[0019] “Reactor-grade,” as used herein, means a polymer that has not been chemically or mechanically treated or blended after polymerization in an effort to alter the polymer's average molecular weight, molecular weight distribution, or viscosity. Particularly excluded from those polymers described as reactor-grade are those that have been visbroken or otherwise treated or coated with peroxide or other prodegradants. For the purposes of this disclosure, however, reactor-grade polymers include those polymers that are reactor blends.

[0020] “Reactor blend,” as used herein, means a highly dispersed and mechanically inseparable blend of two or more polymers produced in situ as the result of sequential or parallel polymerization of one or more monomers with the formation of one polymer in the presence of another in series reactors, or by solution blending polymers made separately in parallel reactors. Reactor blends may be produced in a single reactor, a series of reactors, or parallel reactors and are reactor-grade blends. Reactor blends may be produced by any polymerization method, including batch, semi-continuous, or continuous systems. Particularly excluded from“reactor blend” polymers are blends of two or more polymers in which the polymers are blended ex situ, such as by physically or mechanically blending in a mixer, extruder, or other similar device.

[0021] “Visbreaking,” as used herein, is a process for reducing the molecular weight of a polymer by subjecting the polymer to chain scission. The visbreaking process also increases the melt flow rate (MFR) of a polymer and may narrow its molecular weight distribution. Several different types of chemical reactions can be employed for visbreaking propylene- based polymers. An example is thermal pyrolysis, which is accomplished by exposing a polymer to high temperatures, e.g., in an extruder at 270°C or higher. Other approaches are exposure to powerful oxidizing agents and exposure to ionizing radiation. Another method of visbreaking is the addition of a prodegradant to the polymer. A prodegradant is a substance that promotes chain scission when mixed with a polymer, which is then heated under extrusion conditions. Examples of prodegradants that may be used include peroxides, such as alkyl hydroperoxides and dialkyl peroxides. These materials, at elevated temperatures, initiate a free radical chain reaction resulting in scission of polypropylene molecules. The terms“prodegradant” and“visbreaking agent” are used interchangeably herein. Polymers that have undergone chain scission via a visbreaking process are said herein to be“visbroken.” Such visbroken polymer grades, particularly polypropylene grades, are often referred to in the industry as“controlled rheology” or“CR” grades.

[0022] “Catalyst system,” as used herein, means the combination of one or more catalysts with one or more activators and, optionally, one or more support compositions. An “activator” is any compound(s) or component(s) capable of enhancing the ability of one or more catalysts to polymerize monomers to polymers.

[0023] As used herein,“nonwoven fabric” means a web structure of individual fibers or filaments that are interlaid, but not in an identifiable manner as in a knitted fabric.

Propylene-Based Elastomers

[0024] The compositions described herein contain one or more propylene-based elastomers (“PBEs”). The PBE contains propylene and from 5 wt% to 30 wt% of one or more alpha-olefin derived units, for example, ethylene and/or C4-C 12 a-olefins. In some examples, the alpha-olefin derived units, or comonomer, may be ethylene, butene, pentene, hexene, 4- methyl-l-pentene, octene, or decene. In one or more examples, the comonomer is ethylene. In some embodiments, the PBE consists essentially of propylene and ethylene, or consists only of propylene and ethylene. Some of the embodiments described below are discussed with reference to ethylene as the comonomer, but the embodiments are equally applicable to PBEs with other a-olefin comonomers. In this regard, the copolymers may simply be referred to as PBEs with reference to ethylene as the a-olefin.

[0025] The PBE may include at least 5 wt%, at least 6 wt%, at least 7 wt%, at least 8 wt%, at least 9 wt%, at least 10 wt%, at least 12 wt%, or at least 15 wt%, a-olefin-derived units, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefin-derived units. The PBE may include up to 30 wt%, up to 25 wt%, up to 22 wt%, up to 20 wt%, up to 19 wt%, up to 18 wt%, or up to 17 wt%, a-olefin-derived units, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefin- derived units. In some embodiments, the PBE may contain from 5 wt% to 30 wt%, from 6 wt% to 25 wt%, from 7 wt% to 20 wt%, from 10 wt% to 19 wt%, from 12 wt% to 18 wt%, or from 15 wt% to 17 wt%, a-olefm-derived units, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefm-derived units.

[0026] The PBE may include at least 70 wt%, at least 75 wt%, at least 78 wt%, at least 80 wt%, at least 81 wt%, at least 82 wt%, or at least 83 wt%, propylene-derived units, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefm derived units. The PBE may include up to 95 wt%, up to 94 wt%, up to 93 wt%, up to 92 wt%, up to 91 wt%, up to 90 wt%, up to 88 wt%, or up to 85 wt%, propylene-derived units, where the percentage by weight is based upon the total weight of the propylene-derived and a- olefin derived units.

[0027] The PBEs may be characterized by a melting point (Tm), which can be determined by differential scanning calorimetry (DSC). For purposes herein, the maximum of the highest temperature peak is considered to be the melting point of the polymer. A“peak” in this context is defined as a change in the general slope of the DSC curve (heat flow versus temperature) from positive to negative, forming a maximum without a shift in the baseline where the DSC curve is plotted so that an endothermic reaction would be shown with a positive peak. The T _m of the PBE (as determined by DSC) may be less than l20°C, less than H5°C, less than H0°C, or less than l05°C.

[0028] The PBE may be characterized by its heat of fusion (Elf), as determined by DSC. The PBE may have an Eh that is at least 0.5 J/g, at least 1.0 J/g, at least 1.5 J/g, at least 3.0 J/g, at least 4.0 J/g, at least 5.0 J/g, at least 6.0 J/g, or at least 7.0 J/g. The PBE may be characterized by an Eh of less than 75 J/g, or less than 70 J/g, or less than 60 J/g, or less than 50 J/g. In one or more examples, the PBE has a melting temperature of less than l20°C and a heat of fusion of less than 75 J/g.

[0029] As used within this specification, DSC procedures for determining T _m and Eh are as follows. The polymer is pressed at a temperature of 200°C to 230°C in a heated press, and the resulting polymer sheet is hung, under ambient conditions, in the air to cool. 6 mg to 10 mg sample of the polymer sheet is removed with a punch die. This sample is annealed at room temperature (23°C) for 80 hours to 100 hours. At the end of this period, the sample is placed in a DSC (Perkin Elmer Pyris One Thermal Analysis System) and cooled to -30°C to - 50°C and held for 10 minutes at that temperature. The sample is then heated at l0°C/min to attain a final temperature of 200°C. The sample is kept at 200°C for 5 minutes. Then a second cool-heat cycle is performed, where the sample is again cooled to -30°C to -50°C and held for 10 minutes at that temperature, and then re-heated at lO°C/min to a final temperature of 200°C Events from both cycles are recorded. The thermal output is recorded as the area under the melting peak of the sample, which typically occurs between 0°C and 200°C It is measured in Joules and is a measure of the Hf of the polymer.

[0030] The PBE can have a triad tacticity of three propylene units (mm tacticity), as measured by ¹³ C NMR, of 75% or greater, 80% or greater, 85% or greater, 90% or greater, 92% or greater, 95% or greater, or 97% or greater. For example, the triad tacticity may range from 75% to 99%, from 80% to 99%, from 85% to 99%, from 90% to 99%, from 90% to 97%, or from 80% to 97%. Triad tacticity may be determined by the methods described in U.S. Pat. No. 7,232,871.

[0031] The PBE may have a tacticity index m/r ranging from a lower limit of 4 or 6 to an upper limit of 8, 10, or 12. The tacticity index, expressed herein as“m/r”, is determined by ¹³ C nuclear magnetic resonance (“NMR”). The tacticity index, m/r, is calculated as defined by H. N. Cheng in 17 MACROMOLECULES 1950-1955 (1984), incorporated herein by reference. The designation“m” or“r” describes the stereochemistry of pairs of contiguous propylene groups,“m” referring to meso, and“r” to racemic. An m/r ratio of 1.0 generally describes a syndiotactic polymer, and an m/r ratio of 2.0 describes an atactic material.

[0032] The PBE may have a percent crystallinity of 0.5% to 40%, from 1% to 30%, or from 5% to 25%, determined according to DSC procedures. Crystallinity may be determined by dividing the Hf of a sample by the Hf of a 100% crystalline polymer, which is assumed to be 189 J/g for isotactic polypropylene.

[0033] The PBE may have a density of 0.84 g/cm ³ to 0.92 g/cm ³ , from 0.85 g/cm ³ to 0.90 g/cm ³ , or from 0.85 g/cm ³ to 0.87 g/cm ³ at room temperature (23°C), as measured per the ASTM D-1505 test method.

[0034] The PBE can have a melt index (MI) (ASTM D-1238, 2.16 kg @ l90°C), of less than or equal to 100 decigrams per minute (dg/min), less than or equal to 50 dg/min, less than or equal to 25 dg/min, less than or equal to 10 dg/min, less than or equal to 8 dg/min, less than or equal to 5 dg/min, or less than or equal to 3 dg/min.

[0035] The PBE may have a melt flow rate (MFR), as measured according to ASTM D- 1238 (2.16 kg weight @ 230°C), greater than 0.5 dg/min, greater than 1 dg/min, greater than

1.5 dg/min, greater than 2 dg/min, or greater than 2.5 dg/min. The PBE may have an MFR less than 100 dg/min, less than 50 dg/min, less than 25 dg/min, less than 15 dg/min, less than 10 dg/min, less than 7 dg/min, or less than 5 dg/min. In some embodiments, the PBE may have an MFR from 0.5 dg/min to 10 dg/min, from 1 dg/min to 7 dg/min, or from 1.5 dg/min to 5 dg/min.

[0036] The PBE may have a g' index value of 0.95 or greater, or at least 0.97, or at least 0.99, wherein g' is measured at the Mw of the polymer using the intrinsic viscosity of isotactic polypropylene as the baseline. For use herein, the g' index is defined as: g' = r|b / hi, where r|b is the intrinsic viscosity of the polymer and hi is the intrinsic viscosity of a linear polymer of the same viscosity-averaged molecular weight (Mv) as the polymer hi = KMna, K and a are measured values for linear polymers and should be obtained on the same instrument as the one used for the g' index measurement.

[0037] The PBE may have a weight average molecular weight (Mw), as measured by

DRI, of 50,000 g/mol to 1,000,000 g/mol, or from 75,000 g/mol to 500,000 g/mol, from 100,000 g/mol to 350,000 g/mol, from 125,000 g/mol to 300,000 g/mol, from 150,000 g/mol to 275,000 g/mol, or from 200,000 g/mol to 250,000 g/mol.

[0038] The PBE may have a number average molecular weight (Mn), as measured by DRI, of 5,000 g/mol to 500,000 g/mol, from 10,000 g/mol to 300,000 g/mol, from 50,000 g/mol to 250,000 g/mol, from 75,000 g/mol to 200,000 g/mol, or from 100,000 g/mol to 150,000 g/mol.

[0039] The PBE may have a z-average molecular weight (Mz), as measured by MALLS, of 50,000 g/mol to 1,000,000 g/mol, or from 75,000 g/mol to 500,000 g/mol, or from 100,000 g/mol to 400,000 g/mol, from 200,000 g/mol to 375,000 g/mol, or from 250,000 g/mol to 350,000 g/mol.

[0040] The molecular weight distribution (MWD, equal to Mw/Mn) of the PBE may be from 0.5 to 20, from 0.75 to 10, from 1 to 5, from 1.5 to 4, or from 1.8 to 3.

[0041] Optionally, the PBE may also include one or more dienes. The term“diene” is defined as a hydrocarbon compound that has two unsaturation sites, e.g., a compound having two double bonds connecting carbon atoms. Depending on the context, the term“diene” as used herein refers broadly to either a diene monomer prior to polymerization, e.g., forming part of the polymerization medium, or a diene monomer after polymerization has begun (also referred to as a diene monomer unit or a diene-derived unit). In some embodiments, the diene may be selected from 5-ethylidene-2-norbomene (ENB); l,4-hexadiene; 5-methylene-2- norbomene (MNB); 1 ,6-octadiene; 5-methyl-l,4-hexadiene; 3,7-dimethyl-l,6-octadiene; 1,3- cyclopentadiene; l,4-cyclohexadiene; vinyl norbomene (VNB); dicyclopentadiene (DCPD), and combinations thereof. In embodiments where the PBE composition contains a diene, the diene may be present at from 0.05 wt% to 6 wt%, from 0.1 wt% to 5 wt%, from 0.25 wt% to 3 wt%, from 0.5 wt% to 1.5 wt%, diene-derived units, where the percentage by weight is based upon the total weight of the propylene-derived, a-olefm derived, and diene-derived units.

[0042] Optionally, the PBE may be grafted (e.g.,“functionalized”) using one or more grafting monomers. As used herein, the term“grafting” denotes covalent bonding of the grafting monomer to a polymer chain of the PBE. The grafting monomer can be or include at least one ethylenically unsaturated carboxylic acid or acid derivative, such as an acid anhydride, ester, salt, amide, imide, or acrylates. Illustrative grafting monomers include, but are not limited to, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, maleic anhydride, 4-methyl cyclohexene-l,2-dicarboxylic acid anhydride, bicyclo(2.2.2)octene-2,3-dicarboxylic acid anhydride, 1,2,3,4,5,8,9,10- octahydronaphthalene-2,3-dicarboxylic acid anhydride, 2-oxa-l,3-diketospiro(4.4)nonene, bicyclo(2.2. l)heptene-2,3-dicarboxylic acid anhydride, maleopimaric acid, tetrahydrophthalic anhydride, norbomene-2,3-dicarboxylic acid anhydride, nadic anhydride, methyl nadic anhydride, himic anhydride, methyl himic anhydride, and 5-methylbicyclo(2.2. l)heptene-2,3- dicarboxylic acid anhydride. Other suitable grafting monomers include methyl acrylate and higher alkyl acrylates, methyl methacrylate and higher alkyl methacrylates, acrylic acid, methacrylic acid, hydroxy-methyl methacrylate, hydroxyl-ethyl methacrylate and higher hydroxy-alkyl methacrylates and glycidyl methacrylate. Maleic anhydride is a grafting monomer. In embodiments, the graft monomer can be or include maleic anhydride, and the maleic anhydride concentration in the grafted polymer is in the range of 1 wt% to 6 wt%, such as at least 0.5 wt%, or at least 1.5 wt%.

[0043] In some embodiments, the PBE is a reactor blended polymer as defined herein. That is, the PBE is a reactor blend of a first polymer component and a second polymer component. Thus, the comonomer content of the PBE can be adjusted by adjusting the comonomer content of the first polymer component, adjusting the comonomer content of second polymer component, and/or adjusting the ratio of the first polymer component to the second polymer component present in the PBE.

[0044] In embodiments where the PBE is a reactor blended polymer, the a-olefin content of the first polymer component may be greater than 5 wt% a-olefin, greater than 7 wt% a- olefin, greater than 10 wt% a-olefin, greater than 12 wt% a-olefin, greater than 15 wt% a- olefin, or greater than 17 wt% a-olefin, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefin-derived units of the first polymer component. The a-olefm content of the first polymer component may be less than 30 wt% a-olefin, less than 27 wt% a-olefin, less than 25 wt% a-olefin, less than 22 wt% a-olefin, less than 20 wt% a-olefin, or less than 19 wt% a-olefin, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefin-derived units of the first polymer component. In some embodiments, the a-olefin content of the first polymer component may range from 5 wt% to 30 wt% a-olefin, from 7 wt% to 27 wt% a-olefin, from 10 wt% to 25 wt% a-olefin, from 12 wt% to 22 wt% a-olefin, from 15 wt% to 20 wt% a-olefin, or from 17 wt% to 19 wt% a-olefin. In some examples, the first polymer component contains or comprises propylene and ethylene, and in some embodiments the first polymer component consists only of propylene and ethylene derived units.

[0045] In embodiments where the PBE is a reactor blended polymer, the a-olefin content of the second polymer component may be greater than 1 wt% a-olefin, greater than 1.5 wt% a-olefin, greater than 2 wt% a-olefin, greater than 2.5 wt% a-olefin, greater than 2.75 wt% a- olefin, or greater than 3 wt% a-olefin, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefin-derived units of the second polymer component. The a-olefin content of the second polymer component may be less than 10 wt% a-olefin, less than 9 wt% a-olefin, less than 8 wt% a-olefin, less than 7 wt% a-olefin, less than 6 wt% a- olefin, or less than 5 wt% a-olefin, where the percentage by weight is based upon the total weight of the propylene-derived and a-olefin-derived units of the second polymer component. In some embodiments, the a-olefin content of the second polymer component may range from 1 wt% to 10 wt% a-olefin, or from 1.5 wt% to 9 wt% a-olefin, or from 2 wt% to 8 wt% a- olefin, or from 2.5 wt% to 7 wt% a-olefin, or from 2.75 wt% to 6 wt% a-olefin, or from 3 wt% to 5 wt% a-olefin. In some examples, the second polymer component contains propylene and ethylene, and in some embodiments the first polymer component consists only of propylene and ethylene derived units.

[0046] In one or more examples, the PBE contains propylene-derived units and 5 wt% to 30 wt% of a-olefin-derived units and has a melting temperature of less than l20°C and a heat of fusion of less than 75 J/g.

[0047] In embodiments where the PBE is a reactor blended polymer, the PBE may contain from 1 wt% to 25 wt% of the second polymer component, from 3 wt% to 20 wt% of the second polymer component, from 5 wt% to 18 wt% of the second polymer component, from 7 wt% to 15 wt% of the second polymer component, or from 8 wt% to 12 wt% of the second polymer component, based on the weight of the PBE. The PBE may contain from 75 wt% to 99 wt% of the first polymer component, from 80 wt% to 97 wt% of the first polymer component, from 85 wt% to 93 wt% of the first polymer component, or from 82 wt% to 92 wt% of the first polymer component, based on the weight of the PBE.

[0048] In one or more embodiments, the PBE contains a reactor blend of a first polymer component and a second polymer component. The first polymer component contains propylene and an a-olefin and has an a-olefin content of greater than 5 wt% to less than 30 wt% of the a-olefin, based on the total weight of the propylene-derived and a-olefin derived units of the first polymer component. The second polymer component contains propylene and a-olefin and has an a-olefin content of greater than 1 wt% to less than 10 wt% of the a-olefin, based on the total weight of the propylene-derived and a-olefin derived units of the second polymer component. In one or more examples, the first polymer component has an a-olefin content of 10 wt% to 25 wt% of the a-olefin, based on the total weight of the propylene- derived and a-olefin derived units of the first polymer component. The second polymer component has an a-olefin content of greater than 2 wt% to less than 8 wt% of the a-olefin, based on the total weight of the propylene-derived and a-olefin derived units of the second polymer component. In other examples, the PBE contains 1 wt% to 25 wt% of the second polymer component and 75 wt% to 99 wt% of the first polymer component, based on the weight of the PBE.

[0049] The PBE may be prepared by any suitable means as known in the art. The PBE can be prepared using homogeneous conditions, such as a continuous solution polymerization process, using a metallocene catalyst. In some embodiments, the PBE are prepared in parallel solution polymerization reactors, such that the first reactor component is prepared in a first reactor and the second reactor component is prepared in a second reactor, and the reactor effluent from the first and second reactors are combined and blended to form a single effluent from which the final PBE is separated. Exemplary methods for the preparation of PBEs may be found in U.S. Pat. Nos. 6,881,800; 7,803,876; 8,013,069; and 8,026,323 and PCT Publications WO 2011/087729; WO 2011/087730; and WO 2011/087731.

High Performance Propylene Polymers

[0050] The propylene polymers (PPs) are characterized by a unique combination of specific melt rheological, tacticity molecular parameters, in combination with certain polymeric additives (such as hydrocarbon resins, additional polypropylenes, and/or elastomers), resulted in fibers/fabrics having a superior combination of spinability and tensile properties. In addition, the PPs desirably have distinct rheological (including melt elasticity), shear thinning and chain tacticity characteristics. The PPs are particularly useful for formation of spunbonded fabrics, meltblown fabrics, combinations of spunbonded and meltblown fabric structures as well as partially oriented yams, fully oriented yams, and staple fibers. The PPs are also advantageous in the production of molded parts with high flexural modulus, high tensile strength at yield, and high heat distortion temperature.

[0051] The PPs to be formed into fibers and fabrics are produced by visbreaking a base polypropylene resin (“base resin”), typically by visbreaking a base resin made using a solid magnesium/titanium catalyst component having an melt flow rate (MFR, ASTM D1238, 230°C, 2.16 kg) of 0.1 dg/min, 0.5 dg/min, or 0.8 dg/min to 3 dg/min, 5 dg/min, or 8 dg/min.

[0052] As used herein, “Groups” are groups of the Periodic Table of Elements as in

HAWLEY'S CONDENSED CHEMICAL DICTIONARY (Thirteenth Ed., John Wiley & Sons, New York, 1997).

[0053] As used herein, a“solid magnesium/titanium catalyst component” is a transition metal composition, containing Group 4 atoms, such as titanium, bearing supported multi-site metal-carbon bonds and able to carry out repeated insertions of olefin units to form a polyolefin, where the support is magnesium, but may also contain other Group 2 and/or Group 13-14 atoms. Definitions and examples of solid magnesium/titanium catalyst component used for propylene polymers can be found in POLYPROPYLENE HANDBOOK, 11 -14 (Second Ed., Hanser Publishers, Munich, 2005). Such solid magnesium/titanium catalyst component are used in conjunction with an aluminum alkyl activator (e.g., a separate component from the solid catalyst component), one or more internal electron donors (e.g., a part of the solid catalyst component) and external electron donors such as organosilane compounds (e.g., a separate component from the solid catalyst component) to effect polymerization of olefins to polyolefins, such as, propylene to polypropylene.

[0054] As used herein,“single-site catalyst” means a Group 4 through 10 organometallic transition metal compound capable of initiating olefin catalysis, examples of which include diimine-ligated nickel or palladium complexes such as disclosed by Rui Zhuang et al. in 93 EUROPEAN POLYMER JOURNAL 358-367 (2017); those disclosed by G. H. Hlatky in 100 CHEM. REV. 1,347-1,376 (2000), and K. Press, A. et al. in 50 ANGEW. CHEM. INT. ED. 3,529-3,532 (2011); so-called“metallocene catalysts” such as Group 4 or 5 transition metal compound

(especially hafnium or zirconium) having at least one cyclopentadienyl, indenyl or fluorenyl group attached thereto, or ligand isolobal to those ligands, that is capable of initiating olefin catalysis, typically in combination with an activator, described in POLYPROPYLENE HANDBOOK 45-11 1 (cited above); those that include complexes containing tert-butyl- substituted phenolates, complex phenolates featuring the bulky adamantyl group, the sterically unhindered complex; and“pyridyldiamido and quinolinyldiamido transition metal complexes” such as in U.S. Pat. Nos. 9,290,519 and 9,315,526 which include organometallic complexes of a transition metal ion, especially titanium, zirconium or hafnium, with one or more ligands that include at least one pyridyl and/or quinolinyl group and at least two other alkylamine ligands, and at least one leaving group. Most of these single-site catalysts are activated by an appropriate boron and/or aluminum-based activator. In some examples, the base resins described herein are not derived from polymerization between a single-site catalyst and olefin monomers.

[0055] As used herein,“reactor-grade polymer” means a polymer that has been produced by catalytic formation of carbon-carbon bonds between olefins to form a polymer having a certain molecular weight profile (Mw, Mn, and Mz) and not otherwise treated in any other way to effect its average molecular weight profile such as by visbreaking.

[0056] As used herein, “visbroken” means that the polymer has been thermally or chemically treated to break one or more carbon-carbon bonds in the polymer to create shorter chain lengths and alter its molecular weight profile, lowering the molecular weight, such treatment effected by treatment of the polymer with a visbreaking agent well known in the art such as a peroxide, typically under mild heating and shear conditions such as in a twin or single screw extruder.

[0057] As used herein, a“polypropylene” is a polymer containing at least 90 wt%, or 95 wt%, or 96 wt%, or 97 wt%, or 98 wt%, or 99 wt%, of the polymer, or propylene-derived units, the remainder being selected from one or more of ethylene or C4 to C12 a-olefms, or contains 100 wt% propylene-derived units.

Base Resin

[0058] The“base resin” described herein is a reactor-grade polypropylene made using the solid magnesium/titanium catalyst component described herein, having an MFR of 0.1, 0.5, or 0.8 dg/min to 3, 5, or 8 dg/min. Base resins useful herein include reactor-grade polypropylene homopolymers, copolymers, and blends thereof. The homopolymer may be isotactic polypropylene, syndiotactic polypropylene, or blends thereof (including blends with atactic polypropylene). The copolymer can be a random copolymer, a statistical copolymer, a block copolymer, or blends thereof. The polymerization process for making the base resin is not critical, as it can be made by slurry, solution, gas phase, a supercritical polymerization process as the one described in U.S. Pat. No. 7,807,769, a super-solution homogeneous polymerization process as the one described in U.S. Pub. No. 2010/0113718, or other suitable processes.

[0059] In some examples, the base resin is a unimodal reactor-grade polypropylene, a bimodal reactor-grade polypropylene, an in-reactor blend of polypropylenes, or an extruder blend of two or more reactor-grade polypropylenes (for example, a blend of polypropylenes having MFRs of 0.8 dg/min and 2 dg/min), such as a unimodal reactor-grade polypropylene. The base resin may have a unimodal, bimodal, or multimodal molecular weight distribution (Mw/Mn) distribution of polymer species as determined by GPC. By “bimodal” or “multimodal” is meant that the GPC-SEC trace has more than one peak or inflection point. An inflection point is that point where the second derivative of the curve changes in sign (e.g., from negative to positive or vice versus).

[0060] In at least one embodiment, the catalyst useful to make the base resin is a solid magnesium/titanium catalyst component that includes a solid titanium catalyst component containing titanium as well as magnesium, halogen, at least one non-aromatic “internal” electron donor, and at least one, two or more “external” electron donors. The solid magnesium/titanium catalyst component can be prepared by contacting a magnesium compound, a titanium compound, and at least the internal electron donor. Examples of the titanium compound used in the preparation of the solid titanium catalyst component include tetravalent titanium compounds having the formula Ti(OR _n )X4-n, wherein “R” is a hydrocarbyl,“X” is a halogen atom, and n is from 0 to 4. For purposes of this disclosure, a hydrocarbyl is defined to be Cl to C20 radicals, or Cl to Cl 0 radicals, or C6 to C20 radicals, or C7 to C21 radicals that may be linear, branched, or cyclic where appropriate (aromatic or non-aromatic).

[0061] In some examples, the halogen-containing titanium compound is a titanium tetrahalide, or titanium tetrachloride. In other examples, the magnesium compound to be used in the preparation of the solid titanium catalyst component includes a magnesium compound having reducibility (or capable of alkyl substitution) and/or a magnesium compound having no reducibility. Suitable magnesium compounds having reducibility may, for example, be magnesium compounds having a magnesium-carbon bond or a magnesium-hydrogen bond. Suitable examples of useful magnesium compounds include dimethyl magnesium, diethyl- magnesium, dipropyl magnesium, dibutyl magnesium, diamyl magnesium, dihexyl magnesium, didecyl magnesium, magnesium ethyl chloride, magnesium propyl chloride, magnesium butyl chloride, magnesium hexyl chloride, magnesium amyl chloride, butyl ethoxy magnesium, ethyl butyl magnesium, and/or butyl magnesium halides. In combination with the magnesium compound, the solid magnesium/titanium catalyst component can be supported, thus the solid part of the catalyst.

[0062] In at least one embodiment, the solid magnesium/titanium catalyst component is used in combination with an activator. Compounds containing at least one aluminum-carbon bond in the molecule may be utilized as the activators, also referred to herein as an organoaluminum activator. Suitable organoaluminum compounds include organoaluminum compounds of the general formula R ^l mAl(OR ² )nH _p X _q . wherein R ¹ and R ² are identical or different, and each represents a Cl to Cl 5 hydrocarbyl, or Cl to C4 hydrocarbyl; “X” represents a halogen atom; and“m” is 1, 2, or 3;“n” is 0, 1, or 2;“p” is 0, 1, 2, or 3; and“q” is 0, 1, or 2; and wherein m+n+p+q = 3. Other suitable organoaluminum compounds include complex alkylated compounds of metals of Group I (lithium, etc.) and aluminum represented by the general formula IVriAlR^, where M ¹ is the Group I metal such as lithium, sodium, or potassium, and R ¹ is as defined above. Suitable examples of the organoaluminum compounds include trialkyl aluminums such as trimethyl aluminum, triethyl aluminum and tributyl aluminum; trialkenyl aluminums such as triisoprenyl aluminum; dialkyl aluminum alkoxides such as diethyl-aluminum ethoxide and dibutyl aluminum ethoxide; alkyl aluminum sesquialkoxides such as ethyl aluminum sesquiethoxide and butyl aluminum sesquibutoxide.

[0063] Electron donors are present with the metal components described above in forming the catalyst suitable for producing the polypropylenes described herein. Both “internal” and“external” electron donors may be used for forming the catalyst suitable for making the polypropylene described herein. More particularly, the internal electron donor may be used in the formation reaction of the catalyst as the transition metal halide is reacted with the metal hydride or metal alkyl. Exemplary internal electron donors can be or include amines, amides, ethers, esters, ketones, nitriles, phosphines, stilbenes, arsines, phosphoramides, thioethers, thioesters, aldehydes, alcoholates, and salts of organic acids, any of which may include an aromatic group. The internal electron donors are typically part of the solid catalyst component, while the external electron donors are typically added separately from the solid catalyst component.

[0064] In at least one embodiment, the one or more internal donors are non-aromatic. The non-aromatic internal electron donor can be or include an aliphatic amine, amide, ester, ether, ketone, nitrile, phosphine, phosphoramide, thioethers, thioester, aldehyde, alcoholate, carboxylic acid, or a combination thereof. In some examples, the non-aromatic internal electron donor contains a substituted or unsubstituted C4 to C10 or C20 di-, tri-, or tetra-ether or glycol, a substituted or unsubstituted C4 to C10 or C20 carboxylic acid or carboxylic acid ester that may include one or more ether groups, or a combination of two or more such compounds. By“substituted” what is meant is that the compound may include groups such as hydroxides, amines, silanes, or a combination thereof. In at least one embodiment, the one or more compounds includes secondary or tertiary carbon atoms (thus iso- or tert-hydrocarbon compounds). Such compounds are described in, for example, U.S. Pat. Nos. 5,877,265 and 8,344,079.

[0065] In at least one embodiment, one, two or more external electron donors are used in combination with the solid magnesium/titanium catalyst component. The external electron donors may contain an organic silicon compound of the general formula R ¹ _n Si(OR ² )4-n or R ¹ nSi(NR2 ² )4-n, wherein R ¹ and R ² independently represents a hydrogen or hydrocarbyl and “n” is 1, 2, or 3. Examples of the suitable organic silicon compounds include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldiethoxysilane, t-butylmethyl- n-diethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, bis-o- tolyldimethoxysilane, bis-m-tolyldimethoxysilane, bis-p-tolyldimethoxysilane, bis-p- tolyldimethoxysilane, bisethylphenyldimethoxysilane, dicyclohexyldiethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, g- chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, phenyltriethoxysilane, g-aminopropyltriethoxysilane, chlorotriethoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2- norbomanetriethoxysilane, 2-norbomanemethyldimethoxysilane, ethylsilicate, butylsilicate, trimethylphenoxysilane, methylallyloxysilane, vinyltris( -methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, tetraethoxysilane, methylcyclohexyldimethoxysilane, propyltriethoxysilane, and/or dicyclopentyldimethoxysilane. [0066] In one or more examples, the external electron donors are selected from any one or more of methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, propyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltributoxysilane cyclohexyltrimethoxysilane, tetraethoxysilane, methylcyclohexyldimethoxysilane, propyltriethoxysilane, and/or dicyclopentyldimethoxysilane.

[0067] In at least one embodiment, the production of the polypropylene includes the use of two external electron donors, separately or simultaneously. Suitable methods for using such external electron donors is disclosed in U.S. Pat. Nos. 6,087,459 and 6,686,433. The two external electron donors may be selected from any of the external electron donors described herein. The first external electron donor may have the formula R½Si(OR ² )2, wherein each R ¹ is independently a Cl to C10 hydrocarbyl in which the carbon adjacent to the silicon atom is a secondary or a tertiary carbon atom, and where each R ² is independently a Cl to C10 hydrocarbyl; and the second external electron donor has the formula R ³ _n Si(OR ⁴ )4-n, where each R ³ and R ⁴ are independently a Cl to C10 hydrocarbyl, and“n” is 1, 2, or 3; where the second external electron donor is different than the first external electron donor. The catalyst and the monomers in the reactor can have a combined concentration of external electron donors of 10 ppm, 20 ppm, or 30 ppm to 80 ppm, 100 ppm, or 120 ppm.

[0068] The concentration of the catalyst components in the polymerization may be from

0.01 to 200 millimoles, or from 0.05 to 100 millimoles, calculated as a titanium atom, per liter of an inert hydrocarbon medium. The organoaluminum activator may be present in an amount sufficient to produce from 0.1 to 500 g, or from 0.3 to 300 g, of a polypropylene per gram of the titanium catalyst present, and may be present at from 0.1 to 100 moles, or from 0.5 to 50 moles, per mole of the titanium atom present in the catalyst component.

[0069] In at least one embodiment, the base polypropylene resins useful to make the PPs have one or more of the following features: (a) an weight average molecular weight (Mw) of 240,000 g/mole, 300,000 g/mole, or 265,000 g/mole to 600,000 g/mole, 800,000 g/mole, or 1,000,000 g/mol as measured by the GPC; (b) an Mw/Mn of 1, 2, or 3 to 6, 8, 10, 16, 20, or 25, as measured by the GPC; (c) a second melting temperature (T2nd, second melt, l°C/min ramp speed) of l00°C, l20°C, l30°C, l40°C, or l55°C to l67°C, l70°C, l75°C, l85°C, or 200°C, as measured by the DSC; (d) a percent crystallinity (based on the heat of crystallization) of 10%, 20%, or 35% to 55%, 70%, or 80%, as measured by the DSC; (e) a glass transition temperature (T _g ) of -50°C, -20°C, or 0°C to 90°C, l00°C, or l20°C, as determined by the DSC; (f) a crystallization temperature (T _c , l°C/min ramp speed) with 0% nucleating agent of 50°C, 60°C, 80°C, l00°C, or H5°C to l35°C, l45°C, l50°C, or l70°C, as measured by the DSC; (g) predominantly linear, as indicated by a branching index (gVis) of 0.85, 0.9, 0.95, 0.99 or more, as measured by the GPC method; (h) an MFR (ASTM D1238,

230°C, 2.16 kg) of 0.1 dg/min, 0.5 dg/min, or 0.8 dg/min to 3 dg/min, 5 dg/min, or 8 dg/min; and/or (i) at least 10%, 20%, or 30% tacticity (syndiotactic or isotactic).

[0070] The base resin useful herein has some level of isotacticity. Thus, in at least one embodiment, isotactic polypropylene is used as the base resin herein. In at least one embodiment, the base resin has an average meso run length (MRL) as determined by ¹³ C NMR of higher than 50, higher than 80, higher than 100, higher than 105. The MRL represents the total number of propylene units (on the average) between defects (stereo and regio) based on 10,000 propylene monomers.

[0071] In at least one embodiment, the base resin useful herein is syndiotactic. As used herein,“syndiotactic” is defined as having at least 10% syndiotactic pentads according to analysis by ¹³ C NMR. As used herein,“highly syndiotactic” is defined as having at least 60% syndiotactic pentads according to analysis by ¹³ C NMR.

[0072] In at least one embodiment, the base resin useful herein may contain a blend of a tactic polymer (such as isotactic polypropylene or highly isotactic polypropylene) with an atactic polypropylenes. Atactic polypropylene is defined to be less than 10% isotactic or syndiotactic pentads. Useful atactic polypropylenes typically have a weight average molecular weight (Mw) of 80,000 g/mole to 300,000 g/mole, 400,000 g/mole, 500,000 g/mole, 600,000 g/mole, or 1,000,000 g/mol.

Visbreaking and Visbreaking Agents

[0073] The term“visbreak” is defined as the process of using one or more free-radical initiators to increase polymer MFR, such as described in U.S. Pat. No. 6,747,114. A“free- radical initiator” is a substances that can produce radical species under mild conditions and promote radical reactions, such substances tend to have weak bonds with low dissociation energies. In order to make the PPs useful in fibers/fabrics and other end use articles of manufacture, the base resins described herein are visbroken.

[0074] The free-radical initiator, such as peroxide or azo or diazo compound, may be added to the polymer while the polymer is in a solid form, for example by coating polymer pellets with an initiator, such as peroxide, which may be in powder, liquid, or other form, in which case the polymer is said to be“treated” with the initiator when the initiator becomes active, which usually happens at a temperature higher than melting point of the polymer. In some examples, however, the free-radical initiator is added to the polymer after the polymer has formed, but while the polymer is in a melted condition, for example during the post- polymerization processing, such as when a polymer mixture (which may include solvent) is introduced to a devolatilizer or extruder, which typically occurs at an elevated temperature.

[0075] The term“melted” refers to the condition of the polymer when any portion of the polymer is melted, and includes fully melted and partially melted. The polymer is treated with the free-radical initiator while the temperature of the polymer is above its melting point.

[0076] In one or more examples, the visbreaking agent is an organic peroxide, wherein at least a methyl group or higher alkyl or aryl is bound to one or both oxygen atoms of the peroxide. In at least one embodiment, the visbreaking agent is a sterically hindered peroxide, wherein the alkyl or aryl group associated with each oxygen atom is at least a secondary carbon, or a tertiary carbon. Non-limiting examples of sterically hindered peroxides (“visbreaking agents”) include 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, 2,5-dimethyl- 2,5-bis-(t-butylperoxy)-hexyne-3,4-methyl-4-t-butylperoxy-2- pentanone, 3, 6, 6, 9, 9- pentamethyl-3-(ethylacetate)-l ,2,4,5-textraoxy cyclononane, a,a'-bis-(tert- butylperoxy)diisopropyl benzene, and mixtures of these and any other secondary- or tertiary- hindered peroxides. In one or more examples, the peroxide is 2,5-bis(tert-butylperoxy)-2,5- dimethyl-hexane, also known with the commercial name, Luperox™ 101 or Trigonox™ 101. These compounds can be fed in the extruder pure in liquid form or as a masterbatch blend in mineral oil (e.g., 50/50 weight/weight blend of Trigonox™ lOl/mineral oil). Another common peroxide used as a visbreaking agent for polypropylene is di-t-amyl peroxide, most commonly known with the commercial name “DTAP”. Alternatively, the free-radical initiator may include a diazo compound, or any other compound or chemical that promotes free-radicals in an amount sufficient to cause degradation as specified herein.

[0077] Propylene polymers useful herein can include those that have been treated with a visbreaking agent such that its MFR is increased by at least 10%, by at least 50%, by at least 100%, by at least 300%, by at least 500%, or by at least 650%.

[0078] In at least one embodiment, to form the PP, a base“reactor-grade” polypropylene having an MFR of less than 8 dg/min, less than 6 dg/min, less than 4 dg/min, or less than 3 dg/min is blended with the visbreaking agent while under shear/extensional flow forces and at a melt at a temperature in the range from l90°C, 200°C, or 2lO°C to 250°C, 260°C, or 280°C to form the PP.

Propylene Polymers

[0079] The PPs described herein are polymers derived from visbreaking the base resin described herein and containing at least 90 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, or 99 wt%, by weight of the polymer, or propylene-derived units, the remainder being selected from one or more of ethylene or C4 to C12 a-olefms, or contains 100 wt% propylene-derived units (a homopolymer). In at least one embodiment, the PP is the reaction product of the base resin and one or more visbreaking agents.

[0080] The PP may contain a combination of two or more propylene polymers. The visbroken PP can be further characterized by reference to one or more of the following properties.

[0081] In one or more embodiments, the PP has an MFR of 5 dg/min, 8 dg/min, 10 dg/min, 12 dg/min, 15 dg/min, 17 dg/min, 18 dg/min, or 19 dg/min to 20 dg/min, 22 dg/min, 23 dg/min, 25 dg/min, 28 dg/min, or 30 dg/min. For example, the PP has an MFR of 5 dg/min to 30 dg/min, 10 dg/min to 30 dg/min, 10 dg/min to 25 dg/min, 10 dg/min to 23 dg/min, 10 dg/min to 20 dg/min, 15 dg/min to 30 dg/min, 15 dg/min to 25 dg/min, 15 dg/min to 23 dg/min, 15 dg/min to 20 dg/min, 17 dg/min to 30 dg/min, 17 dg/min to 25 dg/min, 17 dg/min to 23 dg/min, or 17 dg/min to 20 dg/min.

[0082] In other embodiments, the PPs have an MFR Ratio (ratio of MFR after visbreaking to the MFR prior to visbreaking) of 1 to 2.4 and/or 4.5 or greater (e.g., 4.5 to 7), or at least 1, 1.5, 3, 4, 4.5, 6, or 7; or from 1, 1.5, 3, 4, 4.5, 6, or 7 to 9, 10, 12, 16, or 20.

[0083] The PPs have certain desirable tacticity. In at least one embodiment, the PPs have a percentage molar meso pentads (mmmm) content of greater than 0.91, greater than 0.92, or greater than 0.93; or from 0.91, 0.92, or 0.93 to 0.94, 0.95, 0.96, or 0.98. In at least one embodiment, the PP has an MRL determined by ¹³ C NMR of at least 90 or 92 or higher, or from 90, 92, or 94 to 98, 100, 108, or 112. In at least one embodiment, the PP has a total number of defects (stereo and regio) per 10,000 monomers of less than 180, 160, 140, 120, or 110, or from 20, 30, 40, 50, 60, or 70 to 100, 110, 120, 140, 160, or 180. Finally, in at least one embodiment, the PP has a number of stereo defects per 10,000 of less than 150, 140, 130,

120, or 111, or from 40, 50, or 60 to 110, 120, 130, 140, or 150; and a number of regio defects of less than 100, 80, 60, 40, 30, or 10, or from 0 or 10 to 30, 40, 60, 80, or 100. [0084] The PP may also be described by certain rheological features. In at least one embodiment, the PP has a Loss Tangent (tan d) at an angular frequency of 0.1 rad/s at l90°C from 14, 20, or 30 to 70, 80, 90, or 100. The“loss tangent” relates to the melt longest relaxation time as well as creep related properties (e.g., steady state creep compliance and recoverable creep compliance).

[0085] The PP may also have a Dimensionless Stress Ratio Index Ri at l90°C from 1.2 or 1.5 to 4, 4.5, or 5. The PP may also have a Dimensionless Stress Ratio Index R2 at l90°C from 1.5 or 2 to 2.5, 3.5, 4.5, 16, 20, or 28. The“stress ratio” of a polymer relates to the rheometrically measured stress difference on the polymer at a steady shear flow of constant shear rate as a function of the dynamic modulus.

[0086] The PP may also have a Dimensionless Shear Thinning Index R3 at l90°C from 6 or 8 to 10, 13, or 15. Shear thinning behavior in a polymer is demonstrated when the complex viscosity (logarithm) of the polymer as a function of angular frequency applied to the melt possesses a nearly linear (negative slope) relationship. More particularly, shear thinning exists in a polymer when it has a relatively high complex viscosity at very low frequencies (e.g., 0.01 rad/sec), but very low complex viscosity at high frequencies (e.g. 100 rad/sec).

[0087] Also, the PP may also have a Dimensionless Loss Tangent/Elasticity Index R4 at l90°C from 1.5, 2, or 2.5 to 16, 20, or 25.

[0088] The PPs may also have certain thermal features. In some examples, the PP has a T _2nd (second melt, l°C/min) of l20°C or more; or T2nd is from l40°C or l45°C or l50°C to l70°C or l75°C or l 80°C or l 85°C or l90°C. The PP has a percent crystallinity from 20% to 80%. The PP also have a glass transition temperature, T _g , of -50°C to l20°C. In some examples, the PP may also have a branching index (gVis) of 0.85 or more. The PP has a Tc.rhci of l20°C or more, or from l20°C or l25°C or l30°C to l45°C or l50°C or l55°C or l60°C. Finally, the PP has a T _c (l°C per minute) of H5°C or more; or T _c is from l05°C or H0°C to l30°C or l35°C or l40°C or l45°C or l50°C or l55°C.

[0089] The “onset crystallization temperature via rheology,” Tc. rhci is defined as the temperature at which a steep (e.g., neck-like) increase of the complex viscosity and a simultaneous steep decrease of tan d is observed.

[0090] The PPs may also have desirable molecular weight profile. In some examples, the

PP has a weight average molecular weight (Mw) from 190 or 185 kg/mol to 260 kg/mol. The PP also has a z-average molecular weight (Mz) from 250 kg/mol to 600 kg/mol. Also, the PP has an Mw/Mn (Mn is the number average molecular weight) from 1, 2, or 2.5 to 4, 5, 6, or 7, and has an Mz/Mw from 1.5, 1.8, or 2 to 2.2, 2.5, 3.5, or 4.5.

[0091] In at least one embodiment, the PP has a 1% secant flexural modulus of 190 kpsi or higher; or from 180 kpsi or 190 kpsi to 220 kpsi, 280 kpsi, 300 kpsi, 350 kpsi, or 400 kpsi. Also, the PP has a heat distortion temperature (HDT) at 66 psi of 95°C or greater, or from 80°C, 85°C, or 90°C to l00°C, H0°C, H5°C, or l20°C.

[0092] Useful propylene polymers are disclosed for instance in U.S. Pub. No. 2015/0274907.

Dust

[0093] In some embodiments, the compositions containing the PBE and PP may be dusted with a dusting agent as described herein.

[0094] In some examples, the dusting agent is a polymeric powder, for example, a dust containing an ethylene-based polymer. For example, the dusting agent may be a polyethylene powder such as low density polyethylene or a linear low density polyethylene.

[0095] In one or more examples, the dusting agent contains an ethylene-based polymer, and may be for example a homopolymer of ethylene or a copolymer of ethylene and at least one ethylenically unsaturated monomer selected from one or more C3-C10 a-olefms. Exemplary ethylene copolymers include ethylene-propylene, ethylene-butene, and ethylene- 1- octene copolymers. In some embodiments, the ethylene-based polymer is a high density polyethylene (HDPE); a linear low density polyethylene (LLDPE); an ultra-low linear density polyethylene (ULDPE); or a low density polyethylene (LDPE).

[0096] Blend compositions containing the PBE and PP, as described herein, may be contacted with an effective amount of the dusting agent. It is not necessary that each particle or pellet be totally covered with the dusting agent. In addition, it is not necessary that every particle be covered with any dusting agent. Usually, the particles are sufficiently dusted such that the average amount of surface dusting is above 50 percent.

[0097] In some embodiments, the blend compositions are dusted with at least 0.05 wt%, or at least 0.1 wt%, or at least 0.3 wt%, or at least 0.5 wt%, or at least 0.7 wt%, or at least 0.8 wt%, or at least 1 wt%, or at least 1.5 wt%, of the dusting agent based on the total weight of the blend composition.

[0098] The blend composition may be dusted several different ways, including simple admixing, agitation, tumbling, airveying, strand pelletizing, under water pelletizing, and combinations thereof. Exemplary blending equipment/processes include any mechanical means of moving the pellets such as simple tumbling, or blending in a conical rotating vessel, ribbon blender, drum tumbler, paddle blender, agglomeration pan, fluidized bed pneumatic conveyor under air or inert gas, stirring, shaking, screw conveyor or mixing pellets through recirculation in vessels (e.g., silos). Strand pelletizing processes extrude the blend composition into strands that are then dusted and cut into pellets.

Blend Compositions

[0099] Compositions contain one or more PPs and one or more PBEs. In some embodiments, the compositions may contain one PP and one PBE, while in other embodiments, the composition may contain a blend of PBEs blended with one PP, or one PBE blended with a blend of PPs, or a blend of PBEs blended with a blend of PPs.

[00100] The composition can contain 40 wt%, 45 wt%, 50 wt%, 52 wt%, 55 wt%, 58 wt%, 60 wt%, 62 wt% or 65 wt% to 68 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 92 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, or greater of the PP, based on the weight of the composition. For example, the composition can contain 40 wt% to 99 wt%, 45 wt% to 99 wt%, 50 wt% to 98 wt%, 55 wt% to 98 wt%, 60 wt% to 98 wt%, 65 wt% to 98 wt%, 70 wt% to 98 wt%, 75 wt% to 98 wt%, 80 wt% to 98 wt%, 85 wt% to 98 wt%, 90 wt% to 98 wt%, 50 wt% to 95 wt%, 55 wt% to 95 wt%, 60 wt% to 95 wt%, 65 wt% to 95 wt%, 70 wt% to 95 wt%, 75 wt% to 95 wt%, 80 wt% to 95 wt%, 85 wt% to 95 wt%, 90 wt% to 95 wt%, 50 wt% to 90 wt%, 55 wt% to 90 wt%, 60 wt% to 90 wt%, 65 wt% to 90 wt%, 70 wt% to 90 wt%, 75 wt% to 90 wt%, 80 wt% to 90 wt%, 85 wt% to 90 wt%, 87 wt% to 90 wt%, 50 wt% to 88 wt%, 55 wt% to 88 wt%, 60 wt% to 88 wt%, 62 wt% to 88 wt%, 65 wt% to 88 wt%, 68 wt% to 88 wt%, 70 wt% to 88 wt%, 75 wt% to 88 wt%, 80 wt% to 88 wt%, or 85 wt% to 88 wt% of the PP, based on the weight of the composition.

[00101] The composition can contain 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt% or 15 wt% to 18 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 47 wt%, 50 wt%, 55 wt%, 58 wt%, 60 wt%, or greater of the PBE, based on the weight of the composition. For example, the composition can contain 0.5 wt% to 60 wt%, 1 wt% to 50 wt%, 2 wt% to 50 wt%, 3 wt% to 50 wt%, 4 wt% to 50 wt%, 5 wt% to 50 wt%, 7 wt% to 50 wt%, 10 wt% to 50 wt%, 12 wt% to 50 wt%, 15 wt% to 50 wt%, 18 wt% to 50 wt%, 20 wt% to 50 wt%, 25 wt% to 50 wt%, 30 wt% to 35 wt%, 40 wt% to 50 wt%, 1 wt% to 45 wt%, 2 wt% to 45 wt%, 3 wt% to 45 wt%, 4 wt% to 45 wt%, 5 wt% to 45 wt%, 7 wt% to 45 wt%, 10 wt% to 45 wt%, 12 wt% to 45 wt%, 15 wt% to 45 wt%, 18 wt% to 45 wt%, 20 wt% to 45 wt%, 25 wt% to 45 wt%, 30 wt% to 35 wt%, 40 wt% to 45 wt%, 1 wt% to 40 wt%, 2 wt% to 40 wt%, 3 wt% to 40 wt%, 4 wt% to 40 wt%, 5 wt% to 40 wt%, 7 wt% to 40 wt%, 10 wt% to 40 wt%, 12 wt% to 40 wt%, 15 wt% to 40 wt%, 18 wt% to 40 wt%, 20 wt% to 40 wt%, 25 wt% to 40 wt%, 30 wt% to 35 wt%, 1 wt% to 35 wt%, 2 wt% to 35 wt%, 3 wt% to 35 wt%, 4 wt% to 35 wt%, 5 wt% to 35 wt%, 7 wt% to 35 wt%, 10 wt% to 35 wt%, 12 wt% to 35 wt%, 15 wt% to 35 wt%, 18 wt% to 35 wt%, 20 wt% to 35 wt%, 25 wt% to 35 wt%, 30 wt% to 35 wt% of the PBE, based on the weight of the composition.

[00102] In one or more examples, the composition contains 50 wt% to 98 wt% of a PP and 2 wt% to 50 wt% of a PBE, based on the weight of the composition. In some examples, the composition contains 60 wt% to 95 wt% of a PP, and 5 wt% to 40 wt% of a PBE, based on the weight of the composition. In other examples, the composition contains 62 wt% to 88 wt% of a PP, and 10 wt% to 35 wt% of a PBE, based on the weight of the composition.

[00103] The composition can has coefficient of static friction of greater than 0.24, such as 0.25, 0.27, 0.28, 0.30, 0.32, 0.34, 0.35, 0.36, 0.37, 0.38, or 0.39 to 0.40, 0.41, 0.42, 0.43, 0.44, or 0.45. For example, the composition has a coefficient of static friction of 0.25 to 0.45, 0.27 to 0.45, 0.29 to 0.45, 0.30 to 0.45, 0.32 to 0.45, 0.34 to 0.45, 0.35 to 0.45, 0.36 to 0.45, 0.38 to

0.45, 0.25 to 0.42, 0.27 to 0.42, 0.29 to 0.42, 0.30 to 0.42, 0.32 to 0.42, 0.34 to 0.42, 0.35 to

0.42, 0.36 to 0.42, 0.38 to 0.42, 0.25 to 0.40, 0.27 to 0.40, 0.29 to 0.40, 0.30 to 0.40, 0.32 to

0.40, 0.34 to 0.40, 0.35 to 0.40, 0.36 to 0.40, 0.38 to 0.40, 0.25 to 0.38, 0.27 to 0.38, 0.29 to

0.38, 0.30 to 0.38, 0.32 to 0.38, 0.34 to 0.38, 0.35 to 0.38, or 0.36 to 0.38.

[00104] The composition has a peak load in a cross direction of greater than 0.85 newtons per 5 centimeters per gram per square meter (N/5cm/gsm), 0.88 N/5cm/gsm, 0.90 N/5cm/gsm, 0.93 N/5cm/gsm, 0.95 N/5cm/gsm, 0.98 N/5cm/gsm, 1 N/5cm/gsm, 1.3 N/5cm/gsm, 1.5 N/5cm/gsm, or 1.8 N/5cm/gsm to 2 N/5cm/gsm, 2.3 N/5cm/gsm, 2.5 N/5cm/gsm, 2.8 N/5cm/gsm, 3 N/5cm/gsm. For example, the composition has a peak load in a cross direction of greater than 0.85 N/5cm/gsm to 3 N/5cm/gsm, greater than 0.85 N/5cm/gsm to 2.8 N/5cm/gsm, greater than 0.85 N/5cm/gsm to 2.5 N/5cm/gsm, greater than 0.85 N/5cm/gsm to 2.3 N/5cm/gsm, greater than 0.85 N/5cm/gsm to 2 N/5cm/gsm, greater than 0.85 N/5cm/gsm to 1.8 N/5cm/gsm, greater than 0.85 N/5cm/gsm to 3 N/5cm/gsm, 0.9 N/5cm/gsm to 3 N/5cm/gsm, 0.9 N/5cm/gsm to 2.8 N/5cm/gsm, 0.9 N/5cm/gsm to 2.5 N/5cm/gsm, 0.9 N/5cm/gsm to 2.3 N/5cm/gsm, 0.9 N/5cm/gsm to 2 N/5cm/gsm, 1 N/5cm/gsm to 3 N/5cm/gsm, 1 N/5cm/gsm to 2.8 N/5cm/gsm, 1 N/5cm/gsm to 2.5 N, 1 N/5cm/gsm to 2.3 N/5cm/gsm, 1 N/5cm/gsm to 2 N/5cm/gsm, 1 N/5cm/gsm to 1.8 N/5cm/gsm, 1 N/5cm/gsm to 1.5 N/5cm/gsm, 1.3 N to 3 N/5cm/gsm, 1.3 N/5cm/gsm to 2.8 N/5cm/gsm, 1.3 N/5cm/gsm to 2.5 N/5cm/gsm, 1.3 N/5cm/gsm to 2 N/5cm/gsm, 1.3 N/5cm/gsm to 1.8 N, or 1.3 N/5cm/gsm to 1.5 N/5cm/gsm.

[00105] The composition has a peak load in a machine direction of greater than 1.5 N/5cm/gsm, 1.8 N/5cm/gsm, 2 N/5cm/gsm, 2.3 N/5cm/gsm, 2.5 N/5cm/gsm, 2.8 N/5cm/gsm, 3 N/5cm/gsm, or 3.3 N/5cm/gsm to 3.5 N/5cm/gsm, 3.7 N/5cm/gsm, 3.8 N/5cm/gsm, 4

N/5cm/gsm, 4.2 N/5cm/gsm, 4.3 N/5cm/gsm, or 4.5 N/5cm/gsm. For example, the composition has a peak load in a machine direction of greater than 1.5 N/5cm/gsm to 4.5 N/5cm/gsm, greater than 1.5 N/5cm/gsm to 4.3 N/5cm/gsm, greater than 1.5 N/5cm/gsm to 4 N/5cm/gsm, greater than 1.5 N/5cm/gsm to 3.8 N/5cm/gsm, greater than 1.5 N/5cm/gsm to 3.5 N/5cm/gsm, greater than 1.5 N/5cm/gsm to 3.3 N/5cm/gsm, greater than 1.5 N/5cm/gsm to 3 N/5cm/gsm, 1.8 N/5cm/gsm to 4.5 N/5cm/gsm, 1.8 N/5cm/gsm to 4.3 N/5cm/gsm, 1.8 N/5cm/gsm to 4 N/5cm/gsm, 1.8 N/5cm/gsm to 3.8 N/5cm/gsm, 1.8 N/5cm/gsm to 3.5 N/5cm/gsm, 2 N/5cm/gsm to 4.5 N/5cm/gsm, 2 N/5cm/gsm to 4 N/5cm/gsm, 2 N/5cm/gsm to

3.5 N/5cm/gsm, 2 N/5cm/gsm to 3.3 N/5cm/gsm, 2.3 N/5cm/gsm to 4.5 N/5cm/gsm, 2.3 N/5cm/gsm to 4.3 N/5cm/gsm, 2.3 N/5cm/gsm to 4 N/5cm/gsm, 2.3 N/5cm/gsm to 3.8

N/5cm/gsm, 2.3 N/5cm/gsm to 3.5 N/5cm/gsm, 2.3 N/5cm/gsm to 3.3 N/5cm/gsm, 2.3 N/5cm/gsm to 3 N/5cm/gsm, 2.5 N/5cm/gsm to 4.5 N/5cm/gsm, 2.5 N/5cm/gsm to 4.3 N/5cm/gsm, 2.5 N/5cm/gsm to 4 N/5cm/gsm, 2.5 N/5cm/gsm to 3.8 N/5cm/gsm, 2.5 N/5cm/gsm to 3.5 N/5cm/gsm, 2.5 N/5cm/gsm to 3.3 N/5cm/gsm, or 2.5 N/5cm/gsm to 3 N/5cm/gsm.

[00106] The composition has a total hand softness value of 3, 4, 5, 6, 7, 8, 9, or 10 to 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. For example, the composition has a total hand softness value of 3 to 20, 4 to 20, 5 to 20, 6 to 20, 7 to 20, 8 to 20, 9 to 20, 10 to 20, 3 to 18, 4 to 18, 5 to 18, 6 to 18, 7 to 18, 8 to 18, 9 to 18, 10 to 18, 3 to 17, 4 to 17, 5 to 17, 6 to 17, 7 to 17, 8 to 17, 9 to 17, 10 to 17, 3 to 15, 4 to 15, 5 to 15, 6 to 15, 7 to 15, 8 to 15, 9 to 15, or 10 to 15.

[00107] The composition has a melt flow rate (MFR), as measured according to ASTM D- 1238 (2.16 kg weight @ 230°C), of 17 dg/min, 18 dg/min, or 19 dg/min to 20 dg/min, 21 dg/min, 22 dg/min, 23 dg/min, or 24 dg/min. For example, the composition may have a MFR of 17 dg/min to 24 dg/min, 18 dg/min to 23 dg/min, or 19 dg/min to 22 dg/min.

[00108] A variety of additives may be incorporated into the blend compositions described herein, depending upon the intended purpose of the blend. For example, when the blends are used to form films, fibers, and nonwoven fabrics, such additives may include stabilizers, antioxidants, fillers, colorants, dispersing agents, mold release agents, slip agents, fire retardants, plasticizers, pigments, vulcanizing or curative agents, vulcanizing or curative accelerators, cure retarders, processing aids, tackifying resins, and the like. Other additives may include fillers and/or reinforcing materials, such as carbon black, clay, talc, calcium carbonate, mica, silica, silicate, combinations thereof, and the like. Primary and secondary antioxidants include, for example, hindered phenols, hindered amines, and phosphates. Other additives such as dispersing agents, for example, Acrowax C, can also be included. Catalyst deactivators are also commonly used, for example, calcium stearate, hydrotalcite, and calcium oxide, and/or other acid neutralizers known in the art.

[00109] In one or more embodiments, the composition contains one or more slip additives. Exemplary slip agents can be or include one or more of oleamide, erucamide, derivatives thereof, or combinations thereof. The composition can contain 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt%, or 0.9 wt% to 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 7 wt%, 9 wt%, 10 wt%, or greater of the slip additive, based on the weight of the composition. For example, the composition can contain 0.1 wt% to 10 wt%, 0.2 wt% to 10 wt%, 0.5 wt% to 10 wt%, 1 wt% to 10 wt%, 1.5 wt% to 10 wt%, 2 wt% to 10 wt%, 2.5 wt% to 10 wt%, 3 wt% to 10 wt%, 4 wt% to 10 wt%, 5 wt% to 10 wt%, 0.2 wt% to 5 wt%, 0.5 wt% to 5 wt%, 1 wt% to 5 wt%, 1.5 wt% to 5 wt%, 2 wt% to 5 wt%, 2.5 wt% to 5 wt%, 3 wt% to 5 wt%, 4 wt% to 5 wt%, 0.2 wt% to 4 wt%, 0.5 wt% to 4 wt%, 1 wt% to 4 wt%, 1.5 wt% to 4 wt%, 2 wt% to 4 wt%, 2.5 wt% to 4 wt%, 3 wt% to 4 wt%, 0.2 wt% to 3 wt%, 0.5 wt% to 3 wt%, 1 wt% to 3 wt%, 1.5 wt% to 3 wt%, 2 wt% to 3 wt%, 2.5 wt% to 3 wt%, 0.2 wt% to 2 wt%, 0.5 wt% to 2 wt%, 1 wt% to 2 wt%, 1.5 wt% to 2 wt%, or 1.8 wt% to 2.2 wt% of the slip additive, based on the weight of the composition.

[00110] In one or more examples, the composition contains 50 wt% to 98 wt%, 60 wt% to 95 wt%, or 62 wt% to 88 wt% of the PP, 2 wt% to 50 wt%, 5 wt% to 40 wt%, or 10 wt% to 35 wt% of a PBE, and 0.5 wt% to 5 wt%, 1 wt% to 3 wt%, or 1.5 wt% to 2.5 wt% of the slip additive, based on the weight of the composition.

[00111] In some embodiments, additives may be incorporated into the blend compositions directly or as part of a masterbatch, e.g., an additive package containing several additives to be added at one time in predetermined proportions. The masterbatch may be added in any suitable amount to accomplish the desired result. For example, a masterbatch containing an additive may be used in an amount ranging from 0.1 wt% to 10 wt%, or from 0.25 wt% to 7.5 wt%, or from 0.5 wt% to 5 wt%, or from 1 wt% to 5 wt%, or from 2 wt% to 4 wt%, based on the total weight of the polymer blend and the masterbatch. [00112] The blend compositions described herein may be formed by combining the PBE and the PP, and other optional fillers and additives using any suitable means known in the polymer processing art. Those skilled in the art will be able to determine the appropriate methods to enable intimate mixing while also achieving process economy. For example, the components may be blended in a tumbler, continuous mixer, static mixer, batch mixer, extruder, or a combination thereof that is sufficient to achieve an adequate dispersion of the components. For example, the components may be melt-blended in a batch mixer, such as a Banbury™ or Brabender™ mixer.

[00113] In some embodiments, the blend composition is prepared by a method that contains combining the PBE and the PP components and then pelletizing the blend compositions. Without being bound by theory, it is believed that, by pelletizing the blend composition before forming a fabricated article that a more uniform dispersion of the PP within the PBE is achieved. This in turn allows for a more uniform dispersion of the PP within the fabricated article, allowing for improvements in softness of stretch of the fabricated article. Therefore, in some embodiments, the fabricated article may be prepared by a method including: (a) combining (i) a PBE containing from 5 wt% to 25 wt% of ethylene-derived units, based on total weight of the PBE and (ii) a PP to form a blend; (b) pelletizing the blend to form a pellet composition; and (c) using the pellet composition to form a fabricated article. In some embodiments, the nucleating agent is added in step (a). In some embodiments, the method may further include a further step between steps (b) and (c) of blending the pellet composition with a nucleating agent and forming a second pellet composition which is then used to form the fabricated article in step (c). In some embodiments, the method may further include dusting the pelletized blend as described herein.

[00114] In some embodiments, the method of blending may be to melt blend the components in an extruder, such as a single-screw extruder or a twin-screw extruder. Extrusion technology for polymer blends is well known in the art, and is described in more detail in, for example, PLASTICS EXTRUSION TECHNOLOGY, F. Hensen, Ed. (Hanser, 1988), pp. 26-37, and in POLYPROPYLENE HANDBOOK, E. P. Moore, Jr. Ed. (Hanser, 1996), pp. 304-348. For example, the PP may be directly injected into the polymer melt using a liquid injection device at some point along the barrel, as in the case of a twin-screw extruder, or through an opening in a hollow screw shaft, as in the case of a single-screw extruder. The PP can be added downstream from the polymer melt zone, but alternatively the PP can be added at a point where the polymer(s) have not fully melted yet. For example, in a twin-screw extruder, PP can be injected after the first barrel section (e.g., after the first third of the barrel, or in the last third of the barrel). A PP addition point may be on top of conveying elements of screw, or on top of liquid mixing elements of screw, or prior to kneading elements of screw, or prior to liquid mixing elements of the screw. The extruder may have more than one (e.g., two, three, or more) PP addition points along the barrel or screw shaft. Optionally, the PP can be added via the extruder feed throat.

[00115] The components may also be blended by a combination of methods, such as dry blending followed by melt blending in an extruder, or batch mixing of some components followed by melt blending with other components in an extruder. One or more components may also be blended using a double-cone blender, ribbon blender, or other suitable blender, or in a Farrel Continuous Mixer (FCM™).

[00116] Blending may also involve a “masterbatch” approach, where the target PP concentration is achieved by combining neat PBEs and optionally thermoplastic polyolefins and fillers and/or additives with an appropriate amount of pre-blended masterbatch (e.g., a blend of the PBE, PP, and optionally the thermoplastic polyolefin and the filler and additives that have been previously prepared at a higher concentration of PP than desired in the final blend). This is a common practice in polymer processing, typically used for addition of color, additives, and fillers to final compositions. Dispersion (or“letdown”) of the masterbatch may take place as part of a processing step used to fabricate articles, such as in the extruder on an injection molding machine or on a continuous extrusion line, or during a separate compounding step.

[00117] The use of the b-nucleating agents and/or the dusting agents described herein can allow the blends of the PBE and the PP to crystallize at higher temperatures and/or crystallize faster. For example, the blends described herein may exhibit crystallization at temperatures of greater than 50°C, or greater than 55°C, or greater than 60°C, or greater than 65°C, or greater than or equal to 70°C.

[00118] The blend compositions described herein exhibit a DSC crystallization half-time (i) at 40°C of less than 4 minutes, or less than 3 minutes, or less than 2 minutes; (ii) at 50°C of less than 6 minutes, or less than 5 minutes, or less than 4 minutes, or less than 3 minutes; (iii) at 60°C of less than 10 minutes, or less than 9 minutes, or less than 8 minutes, or less than 7 minutes, or less than 6 minutes, or less than 5 minutes, or less than 4 minutes; and/or (iv) at 70°C of less than 10 minutes, or less than 9 minutes, or less than 8 minutes, or less than 7 minutes, or less than 6 minutes, or less than 5 minutes. The isothermal crystallization can be measured using differential scanning calorimetry (DSC) by heating the polymer samples to 200°C, holding the sample for five (5) minutes at 200°C, and then cooling down the sample (as described below) to the temperature at question and allowing the polymer to crystallize at the specified temperature. The half-time (minutes) is the time required to develop one-half (1/2) of the total crystallinity at a given temperature.

[00119] To measure the isothermal crystallization at 40°C and 50°C by DSC the sample is (1) heated to 200°C and held at that temperature for 5 minutes; (2) cooled from 200°C to 70°C at l50°C/min; (3) cooled from 70°C to 50°C at 40°C/min; (4) held for 45 minutes at 50°C (where the crystallization half-time is measured); (5) heated from 50°C to 200°C at l50°C/min; (6) held at 200°C for 5 minutes; (7) cooled from 200°C to 60°C at l50°C/min; (8) cooled from 60°C to 40°C at 40°C/min; and (9) held for 45 minutes at 40°C (where the crystallization half-time is measured).

[00120] To measure the isothermal crystallization at 60°C and 70°C by DSC the sample is (1) heated to 200°C and held at that temperature for 5 minutes; (2) cooled from 200°C to 90°C at l50°C/min; (3) cooled from 90°C to 70°C at 40°C/min; (4) held at 70°C for 45 minutes (where the crystallization half-time is measured); (5) heated from 70°C to 200°C at l50°C/min; (6) held at 200°C for 5 minutes; (7) cooled from 200°C to 80°C at l50°C/min; (8) cooled from 80°C to 60°C at 40°C/min; (9) held at 60°C for 45 minutes (where the crystallization half-time is measured); (10) heated from 60°C to 200°C at 40°C/min; and (11) held for 2 minutes at 200°C.

[00121] As the blends described herein exhibit an onset of crystallization at higher temperatures, this can allow a film containing the blend to crystallize at process/fabrication temperatures. As the film has begun to crystallize during the fabrication process, this allows the film's mechanical properties to stay constant and not change over time. Thus when the film is used to make an elastic laminate, the laminate properties (e.g., max load) will also be more constant over time.

Films Prepared from the Blend Composition

[00122] Films may be prepared from the blend compositions described herein. The film may be formed by any number of well-known extrusion or co-extrusion techniques. For example, any of the blown or chill roll techniques are suitable. For example, the blend composition may be extruded in a molten state through a flat die and then cooled. Alternatively, the blend composition may be extruded in a molten state through an annular die and then blown and cooled to form a tubular film. The tubular film may be axially slit and unfolded to form a flat film. The films may be unoriented, uniaxially oriented or biaxially oriented.

[00123] Multiple-layer films may also be formed using methods well known in the art. For example, layer components may be coextruded through a coextrusion feedblock and die assembly to yield a film with two or more layers adhered together, but differing in composition. Multiple-layer films may also be formed by extrusion coating whereby a substrate material is contacted with the hot molten polymer as the polymer exits the die. For instance, an already formed film may be extrusion coated with a layer of the blend compositions described herein as the latter is extruded through the die. Multiple-layer films may also be formed by combining two or more single layer films prepared as described above. The total thickness of multilayer films may vary based upon the application desired. Those of skill in the art will appreciate that the thickness of individual layers for multilayer films may be adjusted based on desired end use performance, polymer compositions employed, equipment capability, and other like factors.

[00124] The total thickness of the film may vary based upon the application desired. In some embodiments the total unstretched film thickness is 1 pm to 100 pm. Typically, elastic films have a thickness of 5 pm to 50 pm in most applications.

[00125] Thus, provided herein are films containing a blend composition, where the blend composition contains one or more PPs and one or more PBEs as described herein. The film may have improved soft-stretch as compared to films containing similar PBEs but that do not contain the PP and as compared to films containing similar PBEs and lower viscosity PPs.

[00126] Films made with the blend compositions described herein may also crystallize at higher temperatures. This can allow for in-line crystallization during the fabrication process, which allows the film properties to stay more consistent over time.

Fibers and Nonwoven Compositions

[00127] The compositions described herein may be useful in meltspun (e.g., meltblown or spunbond) fibers and nonwoven compositions (e.g., fabrics). As used herein,“meltspun nonwoven composition” refers to a composition having at least one meltspun layer, and does not require that the entire composition be meltspun or nonwoven. As used herein, “nonwoven” refers to a textile material that has been produced by methods other than weaving. In nonwoven fabrics, the fibers are processed directly into a planar sheet-like fabric structure and then are either bonded chemically, thermally, or interlocked mechanically (or both) to achieve a cohesive fabric. [00128] Nonwoven compositions containing the blend of the PP and the PBE may be described as extensible. “Extensible,” as used herein, means any fiber or nonwoven composition that yields or deforms (e.g., stretches) upon application of a force. While many extensible materials are also elastic, the term extensible also encompasses those materials that remain extended or deformed upon removal of the force. When an extensible facing layer is used in combination with an elastic core layer, the extensible layer may permanently deform when the elastic layer to which it is attached stretches and retracts, forming a wrinkled or textured outer surface which gives an additional soft feel that is particularly suited for articles in which the facing layer is in contact with a wearer's skin.

[00129] The fibers and nonwoven compositions can be formed by any method known in the art. For example, the nonwoven compositions may be produced by a spunmelt process. In certain embodiments herein, the layer or layers of the nonwoven compositions of the present disclosure are produced by a spunbond process. When the compositions further contain one or more elastic layers, the elastic layers may be produced by a meltblown process, by a spunbond or spunlace process, or by any other suitable nonwoven process.

[00130] Fibers produced from the blend compositions may have a thickness from 0.5 denier to 10 denier, or from 0.75 denier to 8 denier, or from 1 denier to 6 denier, or from 1 denier to 3 denier. Although commonly referred to in the art and used herein for convenience as an indicator of thickness, denier is more accurately described as the linear mass density of a fiber. A denier is the mass (in grams) of a fiber per 9,000 meters. In practice, measuring 9,000 meters may be both time-consuming and wasteful. Usually, a sample of lesser length (e.g., 900 meters, 90 meters, or any other suitable length) is weighed and the result multiplied by the appropriate factor to obtain the denier of the fiber.

[00131] The fiber denier (g/9,000 m) of a polypropylene-based fiber can be converted to diameter in microns using the following formula:

[00132] Thus, a 1.0 denier polypropylene fiber would have a diameter of 12.5 micron and a 2.0 denier polypropylene fiber would have a diameter of 17.6 micron.

[00133] The fibers may be monocomponent fibers or bicomponent fibers. In some examples, the fibers are monocomponent fibers, meaning that the fibers have a consistent composition throughout their cross-section. [00134] The layer that contains the blend may have a basis weight of less than 50 g/m ² , or less than 40 g/m ² , or less than 30 g/m ² , or less than 25 g/m ² , or less than 20 g/m ² . The layer that contains the blend may have a basis weight of 1 g/m ² to 75 g/m ² , 2 g/m ² to 50 g/m ² , 5 g/m ² to 35 g/m ² , 7 g/m ² to 25 g/m ² , or 10 g/m ² to 25 g/m ² .

[00135] In addition to good extensibility and elongation, fibers containing the blends described herein may also be used to produce fabrics that have improved aesthetics. For example, the fabrics may have an improved feel and softness. Without being bound by theory, it is believed that fabrics produced using the blends described herein have lower bending modulus, due to lower crystallinity, which improves the softness or feel of the fabric. Fabrics made from fibers containing the blends described herein may have improved softness, as measured by a Handle-O-Meter.

[00136] As used herein, “meltblown fibers” and “meltblown compositions” (or “meltblown fabrics”) refer to fibers formed by extruding a molten thermoplastic material at a certain processing temperature through a plurality of fine, usually circular, die capillaries as molten threads or filaments into high velocity, usually hot, gas streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web or nonwoven fabric of randomly dispersed meltblown fibers. Such a process is generally described in, for example, U.S. Pat. Nos. 3,849,241 and 6,268,203. The term meltblowing as used herein is meant to encompass the meltspray process.

[00137] In a typical spunbond process, polymer is supplied to a heated extruder to melt and homogenize the polymers. The extruder supplies melted polymer to a spinneret where the polymer is fiberized as passed through fine openings arranged in one or more rows in the spinneret, forming a curtain of filaments. The filaments are usually quenched with air at a low temperature, drawn, usually pneumatically, and deposited on a moving mat, belt or “forming wire” to form the nonwoven composition. See, for example, in U.S. Pat. Nos. 4,340,563; 3,692,618; 3,802,817; 3,338,992; 3,341,394; 3,502,763; and 3,542,615. The term spunbond as used herein is meant to include spunlace processes, in which the filaments are entangled to form a web using high-speed jets of water (known as“hydroentanglement”). Elastic Laminates

[00138] The blend compositions described herein may be useful in forming a film layer that is part of an elastic laminate. The elastic laminate may contain at least one film layer containing the blend composition and at least one nonwoven facing layer. For example, in some embodiments the elastic laminate contains an inner elastic film layer and two outer nonwoven facing layers. The outer nonwoven facing layers may be made from any polymer that is suitable for forming nonwoven facing layers, and for example may be made from PPs, PBEs, polypropylene, propylene-ethylene copolymers, polyethylene, polyethylene- terephthalate blends (PET), derivatives thereof, and blends thereof.

[00139] A typical laminate or composite has three or more layers, with the elastic film layer(s) (“F”) sandwiched between two or more outer fabric layers that may be spunbonded layers (“S”), meltblown layers (“M”), or spunlace layers (“L”). Examples of laminate combinations include, but are not limited to SFS, MFS, LFL, SFM, SFL, MFL, SSMFMSS, SMFMS, and SMMSS composites. Composites can also be made of the meltblown or spunbond nonwovens of the present disclosure with other materials, either synthetic or natural, to produce useful articles.

[00140] The nonwoven laminate composition may contain one or more elastic film layers containing a PBE and further contain one or more nonwoven facing layers as described herein positioned on one or both sides of the elastic layer(s). In some embodiments, the film is made in a first process and then the roll of film is laminated to nonwoven facing layers, for example, by pressing the layers through a nip and using heat and pressure to bond the nonwoven layers to the film layers, or by ultrasonic bonding, or by using a hot melt adhesive. In some embodiments, the nonwoven laminate is made in an extrusion lamination process where the film layer is extruded onto a pre-existing nonwoven fabric layer. In some embodiments, the nonwoven laminate is made by forming the nonwoven layer directly onto the film layer.

[00141] The nonwoven products described above may be used in many articles such as hygiene products including, but not limited to, diapers, feminine care products, and adult incontinent products. The nonwoven products may also be used in medical products such as sterile wrap, isolation gowns, operating room gowns, surgical gowns, surgical drapes, first aid dressings, and other disposable items. In particular the nonwoven products may be useful as facing layers for medical gowns, and allow for extensibility in the elbow area of the gown. The nonwoven products may also be useful in disposable protective clothing, and may add toughness to elbow and knee regions of such clothing. The nonwoven products may also be useful as protective wrapping, packaging or wound care. The nonwoven products may also be useful in geotextile applications, as the fabric may have improved puncture resistance in that the fabric will deform instead of puncture. EXAMPLES

[00142] Spunbonded nonwoven fabrics were produced on a Reicofil 4 (R4) line having a single spunbond (S) spinneret of 1.1 m width 5,800-6,300 holes with a hole (die) diameter of 0.6 mm. Additional description related to a Reicofil spunbonding process is further described in EP 1340843 and U.S. Pat. No. 6,918,750. Total throughput was 200 kg/hour. The quench air temperature was 20°C for all experiments. The ratio of the volume flow VM of process air to the monomer exhaust device to the process air with volume flow VI escaping from the first upper cooling chamber section into a second lower cooling chamber section (VM/V1) was maintained in the range of from 0.1 to 0.3. Line speed was kept constant at approximately 205 m/min. The filaments were deposited continuously on a deposition web with a targeted fabric basis weight for all examples of 15 g/m **2 (gsm). Fabric basis weight defined as the mass of fabric per unit area was measured by weighing 3 l2”xl2” fabric pieces and reporting an average value expressed in g/m **2 (gsm). Propylene Polymer (e.g., high performance propylene polymer) was delivered to the extruder from the main hopper. The Comparative polypropylene resin was a homopolymer available from ExxonMobil Chemical Company, Houston, Texas, under the tradename PP3155 (MFR of 35 dg/min). Propylene based elastomer was available from ExxonMobil Chemical Company, Houston, Texas, under the tradename Vistamaxx™ 7020BF and was incorporated at the level identified. Slip additive was a masterbatch containing erucamide. The masterbatch was metered in to incorporate 2% of erucamide in all samples. It was obtained from Standridge Color Corporation of Georgia and identified as SCC-88953. Both PBE and Slip additive from masterbatch were also delivered to the extruder from additive feeders running at the appropriate feed rates.

Samples 1-7 were prepared with the compositions provided in Table 1.

[00143] The formed fabric was thermally bonded by compressing it through a set of two heated rolls (calenders) for improving fabric integrity and improving fabric mechanical properties. Fundamentals of the fabric thermal bonding process can be found m the review paper by Michielson et at. “Review of Thermally Point-bonded Nonwovens: Materials, Processes, and Properties”, 99 J. APPLIED POLYM. SCI. 2489-2496 (2005) or the paper by Bhat et al.“Thermal Bonding of Polypropylene Nonwovens: Effect of Bonding Variables on the Structure and Properties of the Fabrics”, 92 J. APPLIED POLYM. SCI. 3593-3600 (2004). The two rolls are referred to as“embossing” and S rolls. The set temperature of the two calenders is listed corresponding to the set oil temperature used as the heating medium of the rolls. In a typical trial, after establishing stable spinning conditions, the calender temperature was varied to create the bonding curve (e.g., tensile strength versus calender temperature). Bonding temperatures varied for the embossed roll from 140°C to 155°C and temperatures for the S roll varied from 137°C to 152°C. Spinnability of the inventive and comparison compositions was assessed to be excellent.

[00144] FIG. 1 illustrates that Samples 1-7 of the polymeric compositions have strong peak load strengths in the cross direction relative to Comparative Examples 1 and 2 (Cl and C2). Samples 1-7 have strong peak load strengths (N/5cm/gsm) in the cross direction of 1.51, 1.46, 1.44, 1.45, 1.0, 1.42, and 1.3, respectively. The peak load strength (N/5cm/gsm) for the

Comparative Examples 1 and 2 are 1.18 and 0.86, respectively. Tensile properties of nonwoven fabrics such as tensile strength in both machine (MD) and cross (CD) directions were measured according to standard method WSP 110.4 (05) with a gauge length of 200 mm and a testing speed of 100 mm/min, unless otherwise indicated. The width of the fabric specimen was 5 cm. For the tensile testing, an Instron machine was used (Model 5565) equipped with instron Bluehill 2 (version 2.5) software for the data analysis. Sample 5 seemed to have an irregularity likely due to basis weight variability in the fabric samples. However, even at 1.0 N/5cm/gsm, Sample 5 is still within the threshold of 0.85 N/5 cm/gsm to 1.2 N/5cm/gsm used as a standard from a Ziegler-Natta homopolymer resin of polypropylene. The combination of the inventive PP in combination with PBE leads to fabrics of similar softness but much improved strength.

[00145] FIG. 2 illustrates that Samples 1-7 of the polymeric compositions have strong peak load strengths in the machine direction. Samples 1-7 have strong peak load strengths (N/5cm/gsm) in the machine direction of 2.68, 2.38, 2.45, 2.44, 1.83, 2.29 and 2.06, respectively. The peak load strength (N/5cm/gsm) for the Comparative Examples 1 and 2 are 2.02 and 1.71 respectively.

[00146] FIG. 3 illustrates that Samples 1-7 of the polymeric compositions have high values for the total hand used as a softness test. Samples 1-7 have total hand of 16.7 g, 10.8 g, 10.1 g, 9.7 g, 9.3 g, 8.5 g, and 7.0 g, respectively. Softness or‘hand” as it is known in the art is measured using the Thw½g-Albert Instruments Co. Plandie-O-Meter (Model 211-10- B/AERGLA). The quality of“hand” is considered to be the combination of resistance due to the surface friction and flexibility of a fabric material. The Handle-O-Meter measures the above two factors using an LVDT (Linear Variable Differential Transformer) to detect the resistance that a blade encounters when forcing a specimen of material into a slot of parallel edges. A 3 1/2 digit digital voltmeter (DVM) indicates the resistance directly in gram force. The“total hand” of a given fabric is defined as the average of 8 readings taken on two fabric specimens (4 readings per specimen). For each test specimen (5 m slot width), the hand is measured on both sides and both directions (MD and CD) and is recorded in grams. A decrease in“total hand” indicates the improvement of fabric softness.

[00147] FIG. 4 illustrates that Samples 1-7 of the polymeric compositions have values for the coefficient of friction (COF) that decrease with increasing amounts of PBE. Decreasing values of COF indicate that the surface is more for silk-like or has less of a rubbery feeling. Samples 1-7 have COF of 0.412, 0.398, 0.409, 0.362, 0.367. 0.379, and 0.369, respectively. The coefficient of friction (COF) of a sheet or nonwoven product is a measure of the ability of the sheet to slide over itself or other surfaces. The TMI Monitor/Slip and Friction Tester, Model 32-06-00, is designed to test the coefficient of starting friction (static friction) and the sliding friction (kinetic friction) between two sheet specimens or between a sheet specimen and an alternative substrate. The sled has the following dimensions, B-sled - 2.5” x 2.5” 200± 5 grams. The tester uses a 0 - 1,200 grams load cell.

[00148] The COF can be drastically altered by the use of additives. These additives sometimes bloom or exude to the surface making the sheet product more or less slippery. The blooming action may not always be uniform over the film surface. Those skilled in the art will appreciate that the value can be affected by the amount of slip additive incorporated. COF is dependent on the rate of motion between two surfaces. Care must be exercised to ensure that the rate of motion of the equipment is controlled. Since COF is a surface phenomenon, films produced by different processes, or under different conditions may give different results. These factors must be considered when evaluating the results.

[00149] Overall, novel polymeric compositions containing one or more PPs and one or more PBEs are useful as nonwoven fabrics, films, fibers, composites, and injection molded articles. The polymeric composition contains a blend of the PP and the PBE in predetermined ratios to provide exceptional softness and non-rubbery feel to the material while maintaining a high tensile strength.

[00150] All documents described herein are incorporated by reference herein, including any priority documents and/or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure.