High melting polypropylene

Abstract

An unnucleated metallocene polypropylene having: (i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4 °F); (i) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °F (265°F); (iii) a lower temperature bound for the isothermal crystallization temperature of from about 120 °C (248°F) to about 154°C (309.2°F); (iv) a flexural modulus of from about 200 kpsi to about 330 kpsi; and (v) a tensile modulus of from about 220 kpsi to about 325 kpsi; and (vi) a tensile strength at yield of from about 4800 psi to about 5900 psi.

Description

HIGH MELTING POLYPROPYLENECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit and priority of U.S. provisional patent application Serial No 63 / 701 ,951 filed on October 1 ,2024, and entitled “HIGH MELTING POLYPROPYLENE,” which is hereby incorporated herein by reference in its entirety for all purposes.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.TECHNICAL FIELD

[0003] The present disclosure relates generally to polymer compositions. More particularly, the present disclosure relates to polypropylene compositions having improved performance characteristics.BACKGROUND

[0004] Polypropylene is a widely used plastic that has high modulus, high tensile strength, good heat resistance, and other favorable properties in the solid-state. The use of polypropylene is due to its beneficial characteristics which include (a) good value for the cost; (b) versatility; (c) low density; (d) excellent impact / stiffness balance; (e) excellent chemical resistance to many common solvents; (f) general chemical inertness; (g) good dimensional stability at high temperatures; (h) good water vapor barrier; (i) high crystallinity; and (j) low thermal conductivity.SUMMARY

[0005] Disclosed herein is an unnucleated metallocene polypropylene having (i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4 °F); (ii) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °F (265°F);and (iii) a lower temperature bound for the isothermal crystallization temperature range of from about 120 °C (248°F); to about 154°C (309.2°F).

[0006] Also disclosed herein is a polypropylene comprising from about 0.01 wt.% to equal to or less than about 1 wt.% of a nucleating agent having (i) a melting temperature of from about from about 155 °C (31 1 °F) to about 183°C (361.4 °F); (ii) a heat deflection temperature of from about 98.9°C (210°F) to about 135°C (275°F);(iii) a lower temperature bound for the isothermal crystallization temperature range of from about 126 °C (258.8°F) to about 160°C (320°F); and (iv) a flexural modulus of from about 220 kpsi to about 350 kpsi.

[0007] Also disclosed herein is an unnucleated polypropylene having (i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4 °F); (ii) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °F (265°F); (iii) a lower temperature bound for the isothermal crystallization temperature range of from about 120 °C (248°F); to about 154°C (309.2°F); (iv) a flexural modulus of from about 200 kpsi to about 350 kpsi; (v) a tensile modulus of from about 220 kpsi to about 335 kpsi; and (vi) a tensile strength at yield of from about 4800 psi to about 6200 psi.

[0008] Aspects described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed aspects in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific aspects disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed aspects. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] For a detailed description of various exemplary aspects, reference will now be made to the accompanying drawings in which:

[0010] Figure 1A is a bar graph of the heat deflection temperature for the indicated polypropylene samples as a function of nucleator type.

[0011] Figure 1 B is a bar graph of the change in heat deflection temperature for the indicated polypropylene samples as a function of nucleator type relative to the corresponding unnucleated sample.

[0012] Figure 1 C is a bar graph of the flexural modulus for the indicated polypropylene samples as a function of nucleator type.

[0013] Figure 1 D is a bar graph of the tensile modulus for the indicated polypropylene samples as a function of nucleator type.

[0014] Figure 1 E is a bar graph of the tensile strength at yield for the indicated polypropylene samples as a function of nucleator type.

[0015] Figure is 2A is a bar graph of the percent crystallinity for the indicated polypropylene samples as a function of nucleator type.

[0016] Figure is 2B is a bar graph of the crystallization enthalpy for the indicated polypropylene samples as a function of nucleator type.

[0017] Figure 2C is a bar graph of the melting enthalpy for the indicated polypropylene samples as a function of nucleator type.

[0018] Figure 3A is a bar graph of the change in crystallinity for the indicated polypropylene samples as a function of nucleator type.

[0019] Figure 3B is a bar graph of the change in crystallization enthalpy for the indicated polypropylene samples as a function of nucleator type.

[0020] Figure 3C is a bar graph of the change in melting enthalpy for the indicated polypropylene samples as a function of nucleator type.DETAILED DESCRIPTION

[0021] The following discussion is directed to various exemplary aspects. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any aspect is meant only to be exemplary of that aspect, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that aspect.

[0022] Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

[0023] Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be interpreted to include only commercially practical values. In addition, with respect to allranges disclosed herein, such ranges are intended to include any combination of the mentioned upper and lower limits even if the particular combination is not specifically listed. All lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11 , 0.12, 0.13, etc.).

[0024] In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to... .” As used herein, the phrases “consist(s) of” and “consisting of” are used to refer to exclusive components of a composition, meaning only those expressly recited components are included in the composition; whereas the phrases “consist(s) essentially of’ and “consisting essentially of” are used to refer to the primary components of a composition, meaning that only small or trace amounts of components other than the expressly recited components (e.g., impurities, byproducts, etc.) may be included in the composition. For example, a composition consisting of X and Y refers to a composition that only includes X and Y, and thus, does not include any other components; and a composition consisting essentially of X and Y refers to a composition that primarily comprises X and Y, but may include small or trace amounts of components otherthan X and Y. In aspects described herein any such small or trace amounts of components otherthan those expressly recited following the phrase “consist (s) essentially of’ or “consisting essentially of’ preferably represent less than 5.0 wt.% of the composition, more preferably less than 4.0 wt.% of the composition even more preferably less than 3.0 wt.% of the composition, and still more preferably less than 1.0 wt.% of the composition. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc. Use of the term "optionally" with respect to any element of a claim is intended to mean that the subject element is required, or additionally or alternatively , is not required. Both alternatives are intended to be within the scope of the claim. As used herein, the terms “approximately,” “about,” “substantially,” and the like mean within 10% (i.e., plus or minus 10%) of therecited value. Thus, for example, a recited angle of “about 80 degrees” refers to an angle ranging from 72 degrees to 88 degrees.

[0025] Commercial processes such as injection molding would benefit from polypropylene having characteristics such as (i) faster crystallization; (ii) higher heat deflection temperature; and (iii) increased stiffness. Further advantageous characteristics are observed with polypropylene prepared using a single-site catalyst. Specifically, single site catalysts provide consistent polymerization creating polymer with (i) low levels of volatiles and oligomers; (ii) superior organoleptic profiles; (iii) high gloss and transparency and (iv) improved control over shrinkage; and (v) reduced warpage. An ongoing need exists to prepare polypropylene combinations of the aforementioned characteristics.

[0026] Disclosed herein are high melt temperature polypropylene compositions characterized by (i) faster crystallization; (ii) higher heat deflection temperature; (iii) increased stiffness; or a combination of (i), (ii) and (iii). A high melt temperature polypropylene of the type disclosed herein is termed a HMTPP.

[0027] In an aspect, a method of the present disclosure comprises polymerization processes where a monomer (such as propylene), and, an optional comonomer, are introduced to (or contacted with) a catalyst system (e.g., metallocene catalyst) under conditions suitable for the formation of a HMTPP.

[0028] Metallocene catalysts refer to coordination compounds incorporating one or more cyclopentadienyl (Cp) groups coordinated with a transition metal and designated M(Cp)xLywhere L is a leaving group and both x and y are equal to or greater than 1 . The Cp ligands are distinct from the leaving groups bound to the catalyst compound in that they are not highly susceptible to substitution / abstraction reactions.

[0029] The Cp groups of the metallocene catalyst may be substituted or unsubstituted. In one or more aspects, substitutions on the Cp ligand are the same. In one or more aspects, at least one substituent on the Cp ligand differs from another substituent on the Cp ligand. The substituent groups on Cp may be linear, branched or cyclic hydrocarbyl radicals, for example. The inclusion of cyclic hydrocarbyl radicals may transform the Cp into other contiguous ring structures, such as indenyl, azulenyl, and fluorenyl groups. These contiguous ring structures may also be substituted or unsubstituted by hydrocarbyl radicals, such as Ci to C20 hydrocarbyl radicals.

[0030] The metal atom, M, of the metallocene catalyst compound may be selected from Groups 3 through 12; additionally or alternatively the lanthanide Group, additionally oralternatively Groups 3 through 10. In one or more aspects, the metal atom is selected from the group consisting of Sc, Ti, Zr, Hf, V, Nb, Ta, Mn, Re, Fe, Ru, Os, Co, Rh, Ir and Ni. The oxidation state of the metal atom "M" may range from 0 to +7 or is +1 , +2, +3, +4 or +5, for example. The bulky ligand generally includes a cyclopentadienyl group (Cp) or a derivative thereof

[0031] Examples of polypropylene prepared through the use of metallocene catalysts are described in further detail in U.S. Pat. Nos. 5,158,920, 5,416,228, 5,789,502, 5,807,800, 5,968,864, 6,225,251 , 6,777,366, 6,777,367, 6,579,962, 6,468,936, 6,579,962 and 6,432,860, each of which is incorporated by reference herein.

[0032] In one or more aspects, the HMTPP comprises a comonomer. Exemplary optional comonomers include ethylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, norbornene, ethylidenenorbornene, vinylnorbornene, norbornadiene, dicyclopentadiene, cyclopentene, cycloheptene, cyclooctene, cyclooctadiene, cyclododecene, 7-oxanorbornene, 7-oxanorbornadiene, substituted derivatives thereof, and isomers thereof, such as hexene, heptene, octene, nonene, decene, dodecene, cyclooctene, 1 ,5-cyclooctadiene, 1-hydroxy-4-cyclooctene, 1 -acetoxy-4-cyclooctene, 5-methylcyclopentene, cyclopentene, dicyclopentadiene, norbornene, norbornadiene, butadiene, hexadiene, heptadiene, octadiene, nonadiene, decadiene, undecadiene, dodecadiene, and their respective homologs and derivatives, such as norbornene, norbornadiene, and dicyclopentadiene.

[0033] In one or more aspects, the HMTPP is prepared using any suitable technology such as suspension, bulk, slurry, homogenous or gas phase polymerization processes. Such processes can be run in a batch, semi-batch, or continuous mode. A homogeneous polymerization process refers to a process where at least 90 weight percent (wt.%) of the product is soluble in the reaction media. A homogeneous polymerization process can be a bulk homogeneous process. A bulk process refers to a process where monomer concentration in all feeds to the reactor is 70 volume percent (vol.%) or more. Alternatively, no solvent or diluent is present or added in the reaction medium, (except for the small amounts used as the carrier for the catalyst system or other additives, or amounts typically found with the monomer; e.g., propane in propylene).

[0034] Any suspension, slurry, high pressure tubular or autoclave process, or gas phase polymerization process can be used under polymerizable conditions. A heterogeneous process is defined to be a process where the catalyst system is not soluble in thereaction media. Alternatively, in other aspects, the polymerization process is not homogeneous.

[0035] In one or more aspects, the polymerization is performed in the gas phase, such as in a fluidized bed gas phase process. Generally, in a fluidized bed gas phase process used for producing polymers, a gaseous stream containing one or more monomers may be continuously cycled through a fluidized bed in the presence of a metallocene catalyst under reactive conditions. The gaseous stream can be withdrawn from the fluidized bed and recycled back into the reactor. Simultaneously, polymer product may be withdrawn from the reactor and fresh monomer added to replace the polymerized monomer.

[0036] In another aspect of the present disclosure, the polymerization is performed in the slurry phase termed a slurry polymerization process. As used herein a “slurry polymerization process” refers to a polymerization process where a supported metallocene catalyst is employed and monomers are polymerized on the supported catalyst particles. At least 95 wt.% of polymer products derived from the supported metallocene catalyst are in granular form as solid particles (i.e., not dissolved in the diluent).

[0037] A slurry polymerization process generally operates between about 1 to about 50 atmosphere pressure range (15 psi to 735 psi, 103 kPa to 5,068 kPa) or even greater. In a slurry polymerization, a suspension of solid, particulate polymer is formed in a liquid polymerization diluent medium to which monomer and comonomers, along with catalysts, are added. The suspension including diluent is intermittently or continuously removed from the reactor where the volatile components are separated from the polymer and recycled, optionally after a distillation, to the reactor. The liquid diluent employed in the polymerization medium is typically an alkane having from 3 to 7 carbon atoms, alternatively a branched alkane. The medium employed should be liquid under the conditions of polymerization and relatively inert.

[0038] In an aspect, a polymerization technique utilized herein is referred to as a particle form polymerization, where the temperature is kept below the temperature at which the polymer goes into solution. The temperature used in the particle form process may be within the range of about 85° C to about 110° C. Alternatively, the polymerization methods for the particle form polymerization are those employing a loop reactor and those utilizing a plurality of stirred reactor in series, parallel, or combinations thereof. Non-limiting examples of particle form polymerization processes include continuous loop or stirred tank processes. In another aspect, the particle form polymerizationprocess is carried out continuously in a loop reactor. The metallocene catalyst, as a slurry in isobutane or as a dry free flowing powder, is injected regularly to the reactor loop, which is itself filled with circulating slurry of growing polymer particles in a diluent (e.g., isobutane containing monomer and comonomer).

[0039] Hydrogen, optionally, may be added to the polymerization process as a molecular weight control. In one or more aspects, hydrogen is present in the polymerization process in an amount of equal to or less than about 500 ppm ; additionally or alternatively less equal to or less than about 400 ppm; additionally or alternatively less equal to or less than about 300 ppm. In other aspects, hydrogen is present in the polymerization process in an amount of equal to or greater than about 50 ppm of hydrogen is added; additionally or alternatively equal to or greater than about 100 ppm; additionally or alternatively equal to or greater than about 150 ppm. Reaction heat may be removed through the loop wall since much of the reactor is in the form of a doublejacketed pipe. The slurry is allowed to exit the reactor at regular intervals or continuously to a heated low-pressure flash vessel, rotary dryer and a nitrogen purge column in sequence for removal of the isobutane diluent and all unreacted monomer and comonomers. The resulting hydrocarbon free powder is then compounded for use in various applications.

[0040] Suitable diluents / solvents for polymerization include non-coordinating, inert liquids. Nonlimiting examples of suitable diluents / solvents for polymerization include straight and branched-chain hydrocarbons, such as isobutane, butane, pentane, isopentane, hexanes, isohexane, heptane, octane, dodecane, and mixtures thereof; cyclic and alicyclic hydrocarbons, such as cyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof, such as can be found commercially (ISOPAR fluids); perhalogenated hydrocarbons, such as perfluorinated C4-C10 alkanes, chlorobenzene, and aromatic and alkylsubstituted aromatic compounds, such as toluene, mesitylene, and xylene. Nonlimiting examples of solvents suitable for use in the polymerization process also include liquid olefins which may act as monomers or comonomers including ethylene, propylene, 1 -butene, 1 -hexene, 1- pentene, 3-methyl-1 -pentene, 4-methyl-1 -pentene, 1 -octene, 1 -decene, and mixtures thereof. In at least one aspect, aliphatic hydrocarbon solvents are used as the solvent, such as isobutane, butane, pentane, isopentane, hexanes, isohexane, heptane, octane, dodecane, and mixtures thereof; cyclic and alicyclic hydrocarbons, such ascyclohexane, cycloheptane, methylcyclohexane, methylcycloheptane, and mixtures thereof.

[0041] Polymerizations can be run at any temperature and / or pressure suitable to obtain the desired propylene polymers. Suitable temperatures and / or pressures may include a temperature in the range of from about 0° C to about 300° C; additionally or alternatively from about 20° C to about 200° C, such as about 35° C to about 150° C, such as from about 40° C to about 120° C; additionally or alternatively from about 45° C to about 80° C; and at a pressure in the range of from about 0.35 MPa to about 10 MPa; additionally or alternatively from about 0.45 MPa to about 6 MPa; additionally or alternatively from about 0.5 MPa to about 4 MPa. The run time of the polymerization reaction can be up to 300 minutes; additionally or alternatively from in the range of from about 5 to 250 minutes; additionally or alternatively from about 10 minutes to about 120 minutes.

[0042] Other additives may also be used in the polymerization process, as desired, such as one or more scavengers, promoters, modifiers, reducing agents, oxidizing agents, aluminum alkyls, silanes, or a combination thereof.

[0043] In one or more aspects, an olefin polymerization process comprises contacting a metallocene catalyst composition of the type disclosed herein with an olefin monomer, optionally hydrogen, and optionally one or more olefin comonomers; and polymerizing the monomer, and the optionally one or more olefin comonomers, in the presence of the metallocene catalyst composition of the type disclosed herein, and optional hydrogen, thereby obtaining an olefin polymer.

[0044] In one or more aspects, the HMTPP comprises a nucleating agent. Herein nucleating agents refer to materials that induce the formation of polymer crystals. Suitable nucleating agents, sometimes are also used as a clarifier, include but are not limited to talc (CAS #14807-96-6), sodium benzoate (NaBz, see CAS #532-32-1 ), carboxylic acid salts and sorbitol and trisamide derivatives; in certain aspects the trisamide benzene compound is N,N',N"-benzene-1 ,3,5-triyltris(2,2- dimethylpropanamide) or RIKaclear® PC1 (N,N',N"-Tris (2-methylcyclohexyl)-1 ,2,3- propanetricarboxamide, CAS Number: 160535-46-6). In some instances, the sorbitol clarifier can be Millad 3905 (1 ,2,3,4-dibenzylidene sorbitol, CAS #32647-67-9), Millad 3940 (1 ,2,3,4-di-para-methylbenzylidene sorbitol, CAS #54686-97-4), Millad 3998 (1 ,2,3,4-di-meta, para-methylbenzylidene sorbitol, CAS #135861-56-2), and NX8000 (1 ,2,3-trideoxy-4,5:5,7-bis-0-[(4-propylphenyl)methylene]-Nonitol, CAS #882073-43-0). In particular aspects, the sorbitol clarifier is NX8000.

[0045] In one or more aspects, the nucleating agent comprises a phosphate ester based nucleating agent. Non-limiting examples of phosphate ester based nucleating agents suitable for use in the present disclosure include 2,2'-methylenebis (4,6,-di- tertbutylphenyl) phosphate or HYPERFORM HPN 715 (Milliken Chemical, Spartanburg, S.C.). 2,2'-methylenebis (4,6,-di-tertbutylphenyl) phosphate which is commercially available from Adeka (Tokyo, Japan) under the tradenames ADK STAB NA-11 , ADK STAB NA-21 , ADK STAB NA-71 or ADK STAB NA-27. NA-27 is NA-11 in combination with a dispersant.

[0046] The amount of nucleating agent present in the HMTPP may be equal to or less than about 1 .0 wt.%; additionally or alternatively equal to or less than about 0.5 wt.%; additionally or alternatively equal to or less than about 0. 1 wt.%; additionally or alternatively equal to or less than about 0.025 wt.%; additionally or alternatively equal to or less than about 0.01 wt.% based on the total weight of the HMTPP. In one or more aspects, the HMTPP excludes a nucleating agent.

[0047] In other aspects, the nucleating agent is present in the HMTPP in an amount ranging from about 1.0 wt. % to about 10 wt.%; additionally or alternatively from about 1 wt.% to about 8 wt.%; additionally or alternatively from about 5 wt.% to about 8 wt.%. in aspects where the nucleator is present in amounts ranging from about 1.0 wt.% to about 10 wt.%, these materials would be typically viewed as a nucleator additive masterbatch, where it would be blended with other polymers by a plastics converter to meet desired end-use requirements.

[0048] In one or more aspects, the melting temperature of the HMTPP ranges from about 153°C to about 183°C, additionally or alternatively from about 155°C to about 180°C; additionally or alternatively; additionally or alternatively from about 155°C to about 175°C; About 153°C, about 154°C, about 155°C, about 156°C, about 157°C, about 158°C, about 159°C, about 160°C, about 161 °C, about 162°C, about 163°C, about 164°C, about 165°C, about 166°C, about 167°C, about 168°C, about 169°C, about 170°C, about 171 °C, about 172°C, about 173°C, about 174°C, about 175°C, about 176°C, about 177°C, about 178°C, about 179°C, about 180°C, about 181°C, about 182°C, about 183°C as determined by nonisothermal differential scanning calorimetry in accordance with ASTM D3418-21.

[0049] Specifically, nonisothermal differential scanning calorimetry may be carried out by equilibrating the sample at 50°C for one minute followed by a procedure where the sample is ramped at 10°C / minute to 210°C, held at 210°C for five minutes, cooled at -10°C / minute to 50°C, held at 50°C for one minute, reheated to 190°C at 10°C / minute, then cooled to 50°C to end the test. This method provides crystallization data such as crystallization temperature and enthalpy during the cooling trace. The second heating trace provides melting temperature and enthalpy.

[0050] In one or more aspects, the HMTPP is characterized by a heat deflection temperature ranging from about 98.9°C to about 135° C; additionally or alternatively from about 100°C to about 132.2°C; additionally or alternatively from about 101 ,7°C to about 129.4°C; additionally or alternatively about100°C, about 102°C, about 104°C, about 106°C, about 108°C, about 110°C, about 112°C, about 114°C, about 116°C, about 118°C, about 120°C, about 122°C, about 124°C, about 126°C, about 128°C, about 130°C, about 132°C, about 134°C, or about 135°C. Herein the heat deflection temperature (HDT) is a measure of a polymer’s resistance to alteration under a given load at an elevated temperature; also known as the ‘deflection temperature under load’ (DTUL) or ‘heat deflection temperature under load (HDTUL)’. The HDT is determined in accordance with ASTM D648-16. For these tests, the values are determined under a load of 0.46 MPa (66 psi).

[0051] In one or more aspects, the HMTPP is characterized by a lower bound of the isothermal temperature range of equal to or greater than about 118 °C; additionally or alternatively equal to or greater than about 120 °C; additionally or alternatively equal to or greater than about 122 °C. Herein the lower bound of the isothermal temperature range refers to lowest temperature at which isothermal testing can be conducted and yield reproducible results for Avrami kinetic fits; for the polypropylenes investigated this lower bound correlates to an onset time for crystallization between about 7.0 to about 7.75 minutes and crystallization half-times ranging between about 7.25 to about 8.75 minutes. Higher temperature lower bounds indicate a polypropylene that thermodynamically favors crystallizing and thereby qualitatively correlates to practical needs such as shorter cycle times in injection molding. The lower bound of isothermal temperature can be determined by differential scanning calorimetry under ASTM E2070-18.

[0052] In one or more aspects, the HMTPP is characterized by an average Avrami exponent (n) of equal to or greater than about 2.00; additionally or alternatively equal to or greater than about 2.10; additionally or alternatively equal to or greater than about 2.15; additionally or alternatively equal to or greater than 2, about 2.02, about 2.03,about 2.04, about2.05, about 2.06, about 2.07, about2.08, about 2.09, about2.1 , about 2.11 , about2.12, about2.14,orabout2.1 additionally or alternatively equal to orgreater than about 2 to about 2.20. The Avrami equation, 1-X(t)=exponent(-Ktn), is used to interpret bulk crystallization kinetics data where X(t) is a measure of crystallinity at time t; K is the Avrami rate constant; and n is the Avrami exponent describing nucleation rate and the dimension of crystal growth.

[0053] In one or more aspects, the HMTPP is characterized by a temperature (T) when the Avrami constant is set to 1 (Ka=1 ) of equal to or greater than about 118 °C; additionally or alternatively equal to or greater than about 120 °C; additionally or alternatively equal to or greater than about 122 °C; additionally or alternatively equal to or greater than about . It is contemplated that by setting Ka=1 forces all materials to be compared at a set crystallization rate 120 °C to about 125°C. The resulting temperature where this occurs can then be compared between materials at the same rate of crystallization. In other words, at the prescribed temperature for each material, the Avarami kinetics would start at the same zero time. A material with a higher temperature would start crystallizing at higher temperature and would be expected to crystallize faster overall compared to materials at a lower temperature. The Avrami related parameters can be determined by differential scanning calorimetry.

[0054] In one or more aspects, the HMTPP has an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 Joules per mole (J / mol); additionally or alternatively of equal to or greater than about 650,000 J / mol; additionally or alternatively of equal to or greater than about 675,000 J / mol; additionally or alternatively equal to or greater than about 600,000 J / mol, about 605,000 J / mol, about 610,000 J / mol, about 615,000 J / mol, about 620,000 J / mol, about 625,000 J / mol, about 630,000 J / mol, about 635,000 J / mol, about 640,000 J / mol, about 645,000 J / mol, about 650,000 J / mol, about 655,000 J / mol, about 660,000 J / mol, about 665,000 J / mol, about 670,000 J / mol, or about 675,000 J / mol; additionally or alternatively from about 600,000 J / mol to about 675,000 J / mol.

[0055] The crystallization activation energy refers to the energy required to initiate the formation of crystalline neat. The activation energy can also affect the crystal growth rate, as a higher activation energy means the reaction will occur slower. The crystallization activation energy can be determined by Avrami kinetic fits to isothermal differential scanning calorimetry under ASTM E2070-18.

[0056] In one or more aspects, an HMTPP of the type disclosed herein is characterized by a percentage crystallinity of from about 51.0% to about 70.0%; additionally or alternatively from about 51 .0% to about 65.0%; additionally or alternatively from about 51 .0% to about 60.0%; additionally or alternatively about 51 %, about 53%, about 55%, about 56%, about 57%, about 59%, about 60%, about 61 %, about 63%, about 64%, about 65%, about 67%, about 69%, or about 70%.

[0057] In one or more aspects, the HMTPP comprises a nucleating agent. In such aspects, the HMTPP may be characterized by a melting temperature of equal to or greater than about 155 °C; additionally or alternatively from about 156°C to about 183°C; additionally or alternatively from about 158°C to about 175°C; additionally or alternatively about 158°C, about 159°C, about 160°C, about 161 °C, about 162°C, about 163°C, about 164°C, about 165°C, about 166°C, about 167°C, about 168°C, about 169°C, about 170°C, about 171 °C, about 172°C, about 173°C, about 174°C, or about 175°C. In such aspects, the HMTPP comprising a nucleating agent is characterized by a lower bound of the isothermal temperature of equal to or greater than about 126 °C; additionally or alternatively of equal to or greater than about 130 °C; additionally or alternatively of equal to or greater than about 132 °C. In such aspects, the HMTPP comprising a nucleating agent is characterized by an average Avrami exponent (n) of equal to or greater than about 2.00, or equal to or greater than about 2.10, or equal to or greater than about 2.15.

[0058] In one or more aspects, the HMTPP comprising a nucleating agent is characterized by a temperature (T) when the Avrami constant is set to 1 (Ka=1 ) of equal to or greater than about 126 °C; additionally or alternatively of equal to or greater than about 128 °C; additionally or alternatively of equal to or greater than about 130 °C. In one or more aspects, the HMTPP comprising a nucleating agent has an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol; additionally or alternatively of equal to or greater than about 650,000 J / mol; additionally or alternatively of equal to or greater than about 700,000 J / mol; additionally or alternatively of equal to or greater than about 600000 J / mol, about 605.000 J / mol, about610.000 J / mol, about 615.000 J / mol, about 620.000 J / mol, about 625.000 J / mol, about630.000 J / mol, about 635.000 J / mol, about 640.000 J / mol, about 645.000 J / mol, about650.000 J / mol, about 655.000 J / mol, about 660.000 J / mol, about 665.000 J / mol, about670.000 J / mol, about 675.000 J / mol, about 680.000 J / mol, about 685.000 J / mol, about 690.000 J / mol, about 695.000 J / mol, or about 700.000 J / mol.

[0059] In one or more aspects, a specimen prepared with an HMTPP of the type disclosed herein is characterized by a flexural modulus of from about 200 kpsi to about 350 kpsi; additionally or alternatively from about 205 kpsi to about 335 kpsi; additionally or alternatively from about 210 kpsi to about 320 kpsi; additionally or alternatively about 250 kpsi, about 255 kpsi, about 260 kpsi, about 265 kpsi, about 270 kpsi, about 275 kpsi, about 280 kpsi, about 285 kpsi, about 290 kpsi, about 295 kpsi, about 300 kpsi, about 305 kpsi, about 310 kpsi, about 315 kpsi, about 320 kpsi, about 325 kpsi, about 330 kpsi, about 335 kpsi, about 340 kpsi, about 345 kpsi, or about 350 kpsi. The flexural modulus refers to the ability of a material to bend without deformation and may be determined in accordance with ASTM D790-15.

[0060] In one or more aspects, a specimen prepared with an HMTPP of the type disclosed herein is characterized by a tensile modulus of from about 220 kpsi to about 335 kpsi; additionally or alternatively from about from about 225 kpsi to about 320 kpsi; additionally or alternatively from about 225 kpsi to about 305 kpsi; additionally or alternatively from about 220 kpsi, about 225 kpsi, about 230 kpsi, about 235 kpsi, about 240 kpsi, about 245 kpsi, about 250 kpsi, about 255 kpsi, about 260 kpsi, about 265 kpsi, about 270 kpsi, about 275 kpsi, about 280 kpsi, about 285 kpsi, about 290 kpsi, about 295 kpsi, about 300 kpsi, about 305 kpsi, about 310 kpsi, or about 315 kpsi. The flexural modulus refers to the ratio of stress to elastic strain in tension and may be determined in accordance with ASTM D790-15.

[0061] In one or more aspects, a specimen prepared with an HMTPP of the type disclosed herein is characterized by a tensile strength at yield of from about 4800 psi to about 6200 psi; additionally or alternatively from about 4850 psi to about 6000 psi; additionally or alternatively from about 4900 psi to about 5800 psi; additionally or alternatively about 4800 psi, about 4900 psi, about 5000 psi, about 5100 psi, about 5200 psi, about 5300 psi, about 5400 psi, about 5500 psi, about 5600 psi, about 5700 psi, about 5800 psi, about 5900 psi, about 6000 psi, about 6100 psi, or about 6200 psi. The tensile strength at yield refers indicates a material’s ability to withstand loads and forces during its lifetime and may be determined in accordance with ASTM D638-14.

[0062] In one or more aspects, the HMTPP is used in the production of an end use article. Nonlimiting examples of end use articles the HMTPP could be used to prepare include bags, totes, diapers, face masks, medical gowns, filter media, oil absorbentwipes, carpet face yarn, raffia, strapping, sheet, food storage containers, storage tubs and totes, automotive body panels, syringe components, pipette tips, caps, closures, and other articles.

[0063] Disclosed herein are polypropylene compositions (HMTPP) having improved polypropylene performance (e.g. increased melting temperature, increased tensile strength) when compared to conventional metallocene catalyzed or Ziegler-Natta catalyzed polypropylene alternatives. Without wishing to be limited by theory, the HMTPP performance improvement is attributable in part to the use of single-site metallocene catalysts which can avoid the complexities and challenges found in Ziegler- Natta catalysis using specialized external donors.ADDITIONAL DISCLOSURE

[0064] The following are nonlimiting exemplary aspects of the presently disclosed subject matter.

[0065] A first aspect which is an unnucleated metallocene polypropylene having: (i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361 .4 °F); (ii) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °F (265°F);and (iii) a lower temperature bound for the isothermal crystallization temperature range of from about 120 °C (248°F); to about 154°C (309.2°F).

[0066] A second aspect which is the polypropylene of claim 1 , having a flexural modulus of from about 200 kpsi to about 350 kpsi.

[0067] A third aspect which is the polypropylene of any of the first through second aspects having a tensile modulus of from about 220 kpsi to about 335 kpsi.

[0068] A fourth aspect which is the polypropylene of any of the first through third aspects having a tensile strength at yield of from about 4800 psi to about 6200 psi.

[0069] A fifth aspect which is the polypropylene of any of the first through fourth aspects having an average Avrami exponent of equal to or greater than about 2.

[0070] A sixth aspect which is the polypropylene of any of the first through fifth aspects having a temperature when the Avrami constant is set to 1 of equal to or greater than about 118 °C.

[0071] A seventh aspect which is the polypropylene of any of the first through sixth aspects having an absolute value for crystallization activating energy of equal to or greater than about 600,000 Joules / mole.

[0072] An eighth aspect which is the polypropylene of any of the first through seventh aspects having a percentage crystallinity of from about 51 % to about 70%.

[0073] A ninth aspect which is an article prepared from the polypropylene of any of the first through eighth aspects.

[0074] A tenth aspect which is a polypropylene comprising from about 0.01 wt.% to equal to or less than about 1 wt.% of a nucleating agent having (i) a melting temperature of from about from about 155 °C (311 °F) to about 183°C (361.4 °F); (ii) a heat deflection temperature of from about 98.9°C (210°F) to about 135°C (275°F); (iii) a lower temperature bound for the isothermal crystallization temperature range of from about 126 °C (258.8°F) to about 160°C (320°F); and (iv) a flexural modulus of from about 220 kpsi to about 350 kpsi.

[0075] An eleventh aspect which is the polypropylene of the tenth aspect having a tensile modulus of from about 230 kpsi to about 335 kpsi;

[0076] A twelfth aspect which is the polypropylene of any of the tenth through eleventh aspects having a tensile strength at yield of from about 5100 psi to about 6200 psi.

[0077] A thirteenth aspect which is the polypropylene of any of the tenth through twelfth aspects with Avrami crystallization kinetics that have (i) an average Avrami exponent (n) of equal to or greater than about 2.00; and (ii) a temperature (T) when the Avrami constant is set to 1 (Ka=1 ) of equal to or greater than about 118 °C (244.4°F); and(iii) having an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol.

[0078] A fourteenth aspect which is the polypropylene of any of the tenth through thirteenth aspects with Avrami crystallization kinetics that have (i) an average Avrami exponent (n) of equal to or greater than about 2.00; and (ii) a temperature (T) when the Avrami constant is set to 1 (Ka=1 ) of equal to or greater than about 127°C (260.6°F).

[0079] A fifteenth aspect which is the polypropylene of any of the tenth through fourteenth aspects having an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol.

[0080] A sixteenth aspect which is the polypropylene of any of the tenth through fifteenth aspects having an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol.

[0081] A seventeenth aspect which is the polypropylene of any of the tenth through sixteenth aspects where it is formulated as a masterbatch with a pigment, colorant or nucleator concentration of from about 1 % to 10% by weight.

[0082] An eighteenth aspect which is an article formed from the polypropylene of any of the tenth through seventeenth aspects.

[0083] A nineteenth aspect which is an unnucleated polypropylene having (i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4 °F); (ii) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °F (265°F); (iii) a lower temperature bound for the isothermal crystallization temperature range of from about 120 °C (248°F); to about 154°C (309.2°F); (iv) a flexural modulus of from about 200 kpsi to about 350 kpsi; (v) a tensile modulus of from about 220 kpsi to about 335 kpsi; and (vi) a tensile strength at yield of from about 4800 psi to about 6200 psi.

[0084] A twentieth aspect which is an article formed from the polypropylene of the nineteenth aspect.EXAMPLES

[0085] The aspects having been generally described, the following examples are given as particular aspects of the disclosure and to demonstrate the practice and advantages thereof. It is understood that the examples are given by way of illustration and are not intended to limit the specification of the claims in any manner.EXAMPLE 1

[0086] The characteristics of an HMTPP of the type disclosed herein were investigated. Throughout the examples, the following homopolymer polypropylene samples were compared using three different base reactor polypropylene powders: 3720WZ-base, M3766-base and inventive material (IM)-based. The 3720WZ-based is a Ziegler-Natta catalyzed homopolymer polypropylene prepared using a commercially available Ziegler Natta catalyst. The M3766-base refers to the polymer M3766 which is a conventional metallocene catalyzed homopolymer polypropylene and the IM-base refers to a differentiated catalyzed metallocene homopolymer polypropylene that yields the HMTPP of the type disclosed herein. Both the 3720WZ and M3766 polymers are commercially available from TotalEnergies. The three base reactor powders were compounded without a nucleator to create unnucleated baseline references designated Unnucl. The same three base reactor powders were also compounded with the sameadditive package as the unnucleated references, but with one change, the addition of one of the following nucleators

[0087] For a given nucleator, the nucleator concentration was held the same between the three base reactor powders to assess relative performance and benefit. The base reactor powders 3720 and M3766 are produced industrially by TotalEnergies.

[0088] Each sample was tested in accordance with ASTM D648-16 at a load of 66 psi to determine the sample’s heat deflection temperature. The results are presented as a bar graph in Figure 1A. The relative effect of nucleator on HDT is presented in Figure 1 B. The flexural modulus, tensile strength and tensile strength at yield for each sample are presented in the graphs of Figures 1 C, 1 D and 1 E respectively.

[0089] The percent crystallinity, crystallization enthalpy and melting enthalpy of the samples are depicted graphically in Figures 2A, 2B and 2C, respectively while the HMTPP’s improved performance is depicted graphically in Figures 3A, 3B and 3C, respectively.

[0090] The results demonstrate that an HMTPP of the type disclosed herein, samples that are IM-based had a higher HDT and the superior relative performance was carried thru with nucleation. It was observed that some nucleators provided synergistic improvement such as talc and NX8000. The nucleators HPN-68L, NA-27 and NaBz provided synergistic improvement when compared to standard the Ziegler Natta polypropylene sample (3720).EXAMPLE 2

[0091] The thermal characteristics of the homopolymer polypropylene samples of Example 1 were investigated. The lower bound of the isothermal temperature range was determined for each sample and the results are presented in Table 1. Additionally, foreach sample the average Avrami Exponent = na, the Avrami constant, temperature at an Avrami constant of 1 and crystallization energy are presented in Tables 1 , 2, 3 and 4, respectively. The IM-based unnucleated polypropylene sample has isothermal temperature range of 124°C to 134°C, matching the range for the 3720-based Ziegler- Natta reference and higher than the standard metallocene M3766-based samples.Table 1Table 2Table 3Table 4

[0092] While various aspects have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the disclosure. The aspects described herein are exemplary only and are not intended to be limiting. Many variations and modifications of the aspects disclosed herein are possible and are within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11 , 0.12, 0.13, etc.). Use of the term "optionally" with respect to any element of a claim is intended to mean that the subject element is required, or alternatively, is not required. Both alternatives are intended to be within the scope of the claim. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc. All test methods are those in effect as of the filing date of this disclosure.

[0093] Accordingly, the scope of protection is not limited by the description set out above but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated into the specification as an aspect of the present disclosure. Thus, the claims are a further description and are an addition to the aspects disclosed herein. The discussion of a reference herein is not an admission that it is prior art to the present disclosure, especially any reference that may have a publication date after the priority date of this application. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference, to the extent that they provide exemplary, procedural or other details supplementary to those set forth herein.

Claims

AMENDED CLAIMS received by the International Bureau on 12 March 2026 (12.03.2026)1. An unnucleated metallocene polypropylene having:(i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4°F);(ii) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °C(265° F); and(iii) a lower temperature bound for the isothermal crystallization temperature range of from about 120 °C (248°F) to about 154°C (309.2T).

2. The polypropylene of claim 1 , having a flexural modulus of from about 200 kpsi to about 350 kpsi.

3. The polypropylene of claim 1 , having a tensile modulus of from about 220 kpsi to about 335 kpsi.

4. The polypropylene of claim 1 , having a tensile strength at yield of from about 4800 psi to about 6200 psi.

5. The polypropylene of claim 1 , having an average Avrami exponent of equal to or greater than about 2.

6. The polypropylene of claim 1, having a temperature when the Avrami constant is set to 1 of equal to or greater than about 118 °C.

7. The polypropylene of claim 1 , having an absolute value for crystallization activating energy of equal to or greater than about 600,000 Joules / mole.

8. The polypropylene of claim 1 , having a percentage crystallinity of from about 51 % to about 70%.

9. An article prepared from the polypropylene of claim 1.

10. A polypropylene comprising from about 0.01 wt.% to equal to or less than about 1 wt.% of a nucleating agent having:(i) a melting temperature of from about 155 °C (311 °F) to about 183°C (361.4°F);(ii) a heat deflection temperature of from about 98.9°C (210°F) to about 135°C(275° F);(iii) a lower temperature bound for the isothermal crystallization temperature range of from about 126 °C (258.8°F) to about 160°C (320°F); and(iv) a flexural modulus of from about 220 kpsi to about 350 kpsi.

11. The polypropylene of claim 10, having a tensile modulus of from about 230 kpsi to about 335 kpsi.

12. The polypropylene of claim 10, having a tensile strength at yield of from about 5100 psi to about 6200 psi.

13. The polypropylene of claim 10, with Avrami crystallization kinetics that have:(i) an average Avrami exponent (n) of equal to or greater than about 2.00; and(ii) a temperature (T) when the Avrami constant is set to 1 (Ka=1) of equal to or greater than about 118 °C (244.4°F); and (iii) having an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol.

14. The polypropylene of claim 10, with Avrami crystallization kinetics that have:(i) an average Avrami exponent (n) of equal to or greater than about 2.00; and(ii) a temperature (T) when the Avrami constant is set to 1 (Ka=1) of equal to or greater than about 127°C (260.6T).

15. The polypropylene of claim 10, having an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol.

16. The polypropylene of claim 14, having an absolute value for crystallization activation energy (Ea) of equal to or greater than about 600,000 J / mol.

17. The polypropylene of claim 10, where it is formulated as a masterbatch with a pigment, colorant or nucleator concentration of from about 1% to 10% by weight.

18. An article formed from the polypropylene of claim 10.

19. An unnucleated polypropylene having:(i) a melting temperature of from about 153 °C (307 °F) to about 183°C (361.4°F);(ii) a heat deflection temperature of from about 98.9°C (210°F) to about 129.4 °C(265°F);(iii) a lower temperature bound for the isothermal crystallization temperature range of from about 120 °C (248°F) to about 154°C (309.2T);(iv) a flexural modulus of from about 200 kpsi to about 350 kpsi;(v) a tensile modulus of from about 220 kpsi to about 335 kpsi; and(vi) a tensile strength at yield of from about 4800 psi to about 6200 psi.

20. An article formed from the polypropylene of claim 19.

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