Polypropylene random copolymer for 3D printing and filaments made therefrom

Abstract

A polymer composition containing a polypropylene polymer with low shrinkage properties is disclosed. The polymer composition is particularly well suited for use in three-dimensional printing systems. For example, the polymer composition containing the polypropylene polymer can be compounded and formed into filaments, rods or pellets, and then fed into a three-dimensional printer. The polypropylene polymer can be a random polypropylene copolymer or terpolymer with a controlled amount of comonomer content and xylene soluble content.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 209,147, filed June 10, 2021, the contents of which are incorporated by reference herein in their entirety for any and all purposes. [Background technology]

[0002] One type of additive manufacturing is called 3D printing. During 3D printing, a part is formed or built layer by layer to create a three-dimensional object from a digital model. 3D printing allows parts with complex geometries to be designed and created in a fast and economical manner. For example, 3D printing can be used to rapidly manufacture prototypes that can be tested. As technology advances, 3D printing can also be used to mass-produce parts and articles in all different industries and fields.

[0003] In one type of three-dimensional printing, a polymer filament is fed into a heated nozzle, which deposits molten thermoplastic material onto a deposition surface. The molten thermoplastic material is applied one layer at a time until a three-dimensional printed article is formed. To produce a three-dimensional article with a specific shape, the nozzle, the deposition surface, or both, are moved while the molten thermoplastic polymer is extruded through the nozzle. The movement of the different components can be controlled by a computer using computer-aided design.

[0004] For example, thermoplastic polymers used in 3D printing must be able to thermally bond to each other when applied in layers to form a consolidated article. Additionally, the thermoplastic polymer should have low shrinkage properties. If the polymer has a tendency to shrink during the process and after the part is formed, warping can occur that lifts and distorts the corners of the printed part. For example, thermoplastic polymers have a tendency to expand when heated and then shrink as they cool and solidify. If the thermoplastic polymer shrinks too much, the different layers of the printed article can separate, resulting in defective parts as well as significant warping. Polymer shrinkage can also be an issue in the filaments used to manufacture the printed article. For example, thermoplastic polymer filaments can undergo bulk shrinkage during printing, which can also cause defects in the top layer of the resulting article. These defects are due to the shrinkage of the printed filaments, which have a higher molecular weight and higher elasticity.

[0005] Thermoplastic polymers that have been used in the past in 3D printing include polylactic acid and acrylonitrile butadiene styrene (ABS). Polylactic acid and ABS generally exhibit shrinkage characteristics of about 1% or less. However, polylactic acid and ABS exhibit lower than desirable interlayer adhesion. ABS polymers can also generate VOCs during the 3D printing process. On the other hand, polylactic acid is hydrophilic, which can cause problems during printing. Therefore, polylactic acid filaments typically need to be stored in sealed packages to avoid moisture prior to the printing process.

[0006] Although polylactic acid and ABS have various shortcomings, some thermoplastic polymers such as polypropylene polymer are not widely used in three-dimensional printing process due to shrinkage and warping problems.However, polypropylene polymer has excellent physical properties that make the polymer well suited for use in the manufacture of molded articles.Therefore, in view of the above, there is a need for a polymer composition that contains polypropylene polymer that can be used in three-dimensional printing process. Summary of the Invention

[0007] In general, the present disclosure relates to a polymer composition containing a polypropylene polymer that is well suited for use in a material extrusion process for producing three-dimensional articles. The present disclosure is also directed to a polymer material for a three-dimensional extrusion printing system. According to the present disclosure, the polymer composition containing a polypropylene polymer is formulated to exhibit low shrinkage and warpage properties.

[0008] In one embodiment, for example, the present disclosure relates to a polymeric material for a three-dimensional extrusion printing system. The polymeric material is in the form of a feedstock having a size and shape suitable for being fed into a three-dimensional printing system. The feedstock may include a continuous filament. When in the form of a filament, the filament may have a filament diameter of about 0.5 mm to about 6 mm, such as about 1.0 mm to about 4 mm. Alternatively, the feedstock may include polymeric pellets or polymeric rods. According to the present disclosure, the feedstock comprises a polymeric composition containing a polypropylene polymer in an amount greater than about 50% by weight. For example, the polymeric composition may include a polypropylene polymer in an amount greater than about 60% by weight, such as greater than about 70% by weight, such as greater than about 80% by weight, such as greater than about 90% by weight.

[0009] The polypropylene polymer included in the polymeric material is particularly configured for use in a three-dimensional printing process. The polypropylene polymer includes, for example, a polypropylene random copolymer or terpolymer. More specifically, the polypropylene polymer includes propylene as the main monomer and contains at least one comonomer of ethylene or butene. The total comonomer content of the polypropylene polymer is about 3% to about 25% by weight. For example, the polypropylene polymer can have an ethylene content of 0% to about 10% by weight and a butene content of 0% to about 20% by weight. The polypropylene polymer can have a xylene soluble content of about 4.5% to about 45% by weight, such as about 5% to about 30% by weight, such as about 10% to about 30% by weight. In one embodiment, the xylene soluble content can be greater than about 12%, such as greater than about 18%, such as greater than about 20%. For example, the polypropylene polymer can have a melt flow rate of from about 20 g / 10 min to about 200 g / 10 min, such as from about 20 g / 10 min to about 100 g / 10 min.

[0010] In one embodiment, the polypropylene polymer comprises a copolymer of propylene and ethylene. The copolymer can have an ethylene content of about 3% to about 10% by weight, such as about 5% to about 9% by weight. Alternatively, the polypropylene polymer can comprise a copolymer of propylene and butene. The propylene and butene random copolymer can have a butene content of about 5% to about 20% by weight, such as about 10% to about 18% by weight. In yet another embodiment, the polypropylene polymer can comprise a propylene, ethylene, and butene terpolymer.

[0011] The polypropylene polymer can have a crystallinity of less than about 50%, for example less than about 40%. The polypropylene polymer can have a molecular weight distribution (Mw / Mn) of about 2.5 to about 10, for example about 3 to about 6. The polypropylene polymer can be Ziegler-Natta catalyzed, for example using a non-phthalate catalyst. The catalyst can include, for example, a substituted phenylene diester.

[0012] In one embodiment, the polymeric material can contain one or more fillers in addition to the polypropylene polymer. The fillers can be, for example, talc, calcium carbonate, glass fiber, or mixtures thereof. The fillers can be present in the polymeric composition in an amount of about 0% to about 40% by weight.

[0013] The present disclosure is also directed to a printer cartridge for three-dimensional extrusion printing. The printer cartridge includes a feedstock made from a polymeric material as described above. For example, when in the form of a filament, the polymeric material may be included in the printer cartridge wound around a spool.

[0014] The present disclosure also relates to a three-dimensional printing system comprising a three-dimensional printing apparatus and a printer cartridge as described above. The present disclosure also relates to a three-dimensional article formed layer by layer in a material extrusion process. The present disclosure also relates to a material extrusion method comprising selectively forming a three-dimensional structure from the above-described polymer material.

[0015] Other features and aspects of the disclosure are discussed in more detail below. [Brief description of the drawings]

[0016] A full and enabling disclosure of the present disclosure is more particularly set forth in the remainder of the specification, including reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a plan view of one embodiment of a material extrusion system that may be used in accordance with the present disclosure. [Diagram 2] 1 is a perspective view of one embodiment of a printer cartridge that may be used in accordance with the present disclosure. [Diagram 3] FIG. 2 is a perspective view showing the dimensions of the model used in the warpage testing described in the Examples below. [Figure 4] FIG. 1 is a perspective view with dimensions of another model used for warpage testing described in the Examples below.

[0017] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Those skilled in the art will appreciate that this discussion is a description of exemplary embodiments only, and is not intended to limit the broader aspects of the disclosure.

[0019] As used herein and in the appended claims, in the context of describing elements (particularly in the context of the claims that follow), singular articles such as "a" and "an" and "the" and similar referents shall be construed to cover both the singular and the plural, unless otherwise stated herein or clearly contradicted by context. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of individually referring to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated herein as if it were individually recited herein. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or the content is otherwise clearly contradictory. The use of any and all examples or exemplary language (e.g., "etc.") provided herein is intended only to better illustrate the embodiments and does not impose limitations on the scope of the claims, unless otherwise indicated. No language in this specification should be construed as indicating any non-claimed element as essential.

[0020] As used herein, "about" will be understood by those of ordinary skill in the art and will vary to some extent depending on the context in which it is used. If there is any use of a term that is not clear to those of ordinary skill in the art, taking into account the context in which it is used, "about" will be understood to mean up to plus or minus 10% of the particular term, for example, "about 10% by weight" means "9% to 11% by weight". When "about" precedes a term, it should be understood that the term should be interpreted as disclosing the same term as that term without modification by "about", for example, "about 10% by weight" discloses "9% to 11% by weight" and discloses "10% by weight".

[0021] The phrase "and / or" as used in this disclosure is understood to mean any one of the listed members individually or any two or more combinations thereof, for example, "A, B, and / or C" means "combinations of A, B, C, A and B, A and C, B and C, or A, B, and C."

[0022] As will be understood by those of skill in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein encompass any and all possible subranges and combinations thereof. It can be easily recognized that any recited range fully describes and allows for the same range to be subdivided into at least two, three, four, five, ten, etc. As a non-limiting example, each range discussed herein can be easily subdivided into a lower third, a middle third, an upper third, etc. Also, as will be understood by those of skill in the art, all terms such as "up to," "at least," "greater than," "less than," etc. refer to ranges that include the recited numbers and that can then be subdivided into the subranges discussed above. Finally, as will be understood by those of skill in the art, a range includes each individual member. Thus, for example, a group having 1-3 atoms refers to groups having 1, 2, or 3 atoms. Similarly, a group having 1-5 atoms refers to groups having 1, 2, 3, 4, or 5 atoms, etc.

[0023] The term "propylene-ethylene copolymer" as used herein is a copolymer containing a majority weight percent of propylene monomer with ethylene monomer as the secondary constituent. A "propylene-ethylene copolymer" (also called polypropylene random copolymer, PPR, PP-R, RCP, or RACO) is a polymer with individual repeat units of ethylene monomer present in a random or statistical distribution in the polymer chain.

[0024] The term "propylene-butene copolymer," as used herein, is a copolymer containing a majority weight percent of propylene monomer with butene monomer as a minor constituent. A "propylene-butene copolymer" (also called a polypropylene-butene random copolymer) is a polymer having individual repeat units of butene monomer present in a random or statistical distribution in the polymer chain.

[0025] Melt flow rate (MFR), as used herein, is measured according to ASTM D1238 test method at 230° C. with a weight of 2.16 kg for propylene-based polymers.

[0026] Xylene solubles (XS) are defined as the weight percent of resin remaining in solution after dissolving a sample of polypropylene random copolymer resin in hot xylene and cooling the solution to 25°C. This is also referred to as the gravimetric XS method according to ASTM D5492-06 using a 90 minute precipitation time, also referred to herein as the "wet method". XS can also be measured according to the Viscotek Flow Injection Polymer Analysis (FIPA) method as follows: 0.4 g of polymer is dissolved in 20 mL of xylene with stirring at 130°C for 60 minutes. The solution is then cooled to 25°C and after 60 minutes the insoluble polymer fraction is filtered off. The resulting filtrate is analyzed by flow injection polymer analysis using a Viscotek ViscoGEL H-100-3078 column with a THF mobile phase at 1.0 mL / min. The column is coupled to a Viscotek Model 302 Triple Detector Array with light scattering viscometer and refractometer detectors operating at 45°C. Instrument calibration is maintained with Viscotek PolyCAL™ polystyrene standards. A polypropylene (PP) homopolymer, such as biaxially oriented polypropylene (BOPP) grade Dow5 D98, is used as a reference material to ensure consistent results with the Viscotek instrument and sample preparation procedures by using 5D98 as a control to check method performance. The 5D98 value is initially derived from testing using the ASTM method described above.

[0027] The ASTM D5492-06 method mentioned above can be adapted to determine the xylene soluble fraction. In general, the procedure consists of weighing 2 g of sample and dissolving the sample in 200 mL of o-xylene in a 400 mL flask equipped with a 24 / 40 fitting. The flask is connected to a water-cooled condenser, the contents are stirred and heated to reflux under nitrogen (N2), and then maintained at reflux for an additional 30 minutes. The solution is then cooled in a temperature-controlled water bath at 25°C for 90 minutes to allow crystallization of the xylene insoluble fraction. Once the solution is cooled and the insoluble fraction precipitates from the solution, separation of the xylene soluble fraction (XS) from the xylene insoluble fraction (XI) is achieved by filtration through 25 micron filter paper. 100 ml of the filtrate is collected in a pre-weighed aluminum pan, and the o-xylene is evaporated from this 100 ml filtrate under a stream of nitrogen. Once the solvent has evaporated, the pan and contents are placed in a vacuum oven at 100° C. for 30 minutes or until dry. The pan is then cooled to room temperature and weighed. The xylene soluble portion is calculated as XS (wt%)=[(m3-m2) * 2 / m1] * 100, where m1 is the original weight of the sample used, m2 is the weight of the empty aluminum pan, and m3 is the weight of the pan and residue (asterisks used here and elsewhere in this disclosure). * indicates that the identified term or value is to be multiplied.

[0028] The ethylene or butene content was also measured using the Fourier Transform Infrared method (FTIR), which is the first method: 13 The sequence distribution of monomers in the polymer is correlated to the ethylene or butene values ​​determined using C NMR. 13 C-NMR, which also allows the location of the butene residues in relation to the adjacent propylene residues. 13 C NMR can be used to measure ethylene content, butene content, triad distribution, and triad tacticity and is performed as follows. · Samples are prepared by adding approximately 2.7 g of a 50 / 50 mixture of tetrachloroethane-d2 / orthodichlorobenzene containing 0.025M Cr(AcAc)3 to 0.20 g of sample in a Norell 1001-710 mm NMR tube. The sample is dissolved and homogenized by heating the tube and its contents to 150°C using a heating block. Each sample is visually inspected to ensure homogeneity. · Data are collected using a Bruker 400MHz spectrometer equipped with a Bruker Dual DUL high temperature CryoProbe. Data are acquired using 512 transients per data file, a pulse repetition delay of 6 seconds, a flip angle of 90 degrees, and reverse gate decoupling at a sample temperature of 120°C. All measurements are performed on unspun samples in locked mode. Samples are allowed to thermally equilibrate for 10 minutes prior to data acquisition. The percent mm tacticity and weight % butene were calculated according to methods commonly used in the art, which are briefly summarized as follows: For the measurement of the chemical shifts of the resonances, the methyl group of the third unit in a sequence of five consecutive propylene units consisting of head-to-tail bonds and having the same relative chirality is set to 21.83 ppm. By using the above value as a reference, the chemical shifts of the other carbon resonances are determined. The spectrum for the methyl carbon region (17.0-23 ppm) can be divided into the first region (21.1-21.9 ppm), the second region (20.4-21.0 ppm), the third region (19.5-20.4 ppm), and the fourth region (17.0-17.5 ppm). Each peak in the spectrum is assigned by reference to a literature source, such as, for example, articles in Polymer, T. Tsutsui et al., Vol. 30, Issue 7, (1989) 1350-1356 and / or Macromolecules, HN Cheng, 17 (1984) 1950-1955, the contents of which are incorporated herein by reference. For convenience, butene content is also measured using the Fourier Transform Infrared method (FTIR), which is described above as the first method.13 The butene values ​​determined using C NMR are correlated to those determined using C NMR. The relationship and agreement between measurements performed using the two methods is described, for example, in J.R. Paxson, J.C. Sandall, "Quantitative Measurement of Ethylene Incorporation into Propylene Copolymers by Carbon-13 Nuclear Magnetic Resonance and Infrared Spectroscopy", Analytical Chemistry, Vol. 50, No. 13, Nov. 1978, 1777-1780.

[0029] Mw / Mn (also called "MWD") and Mz / Mw are measured by Gel Permeation Chromatography (GPC) according to the Polypropylene Analysis Method. The polymers are analyzed on a Polymer Char High Temperature GPC equipped with an IR5 MCT (mercury cadmium telluride high sensitivity, thermoelectrically cooled IR detector), a Polymer Char four-capillary viscometer, a Wyatt 8-corner MALLS, and three Agilent Plgel Olexis (13um). The oven temperature is set at 150°C. The solvent is nitrogen purged 1,2,4-trichlorobenzene (TCB) containing approximately 200 ppm of 2,6-di-t-butyl-4-methylphenol (BHT). The flow rate was 1.0 mL / min and the injection volume was 200 μl. A sample concentration of 2 mg / mL is prepared by dissolving the sample in N2-purged and preheated TCB (containing 200 ppm BHT) with gentle stirring for 2 hours at 160° C. For data processing purposes, integration limits are set to correspond to 3500 g / mol at low molecular weight and the point where the signal intensity coincides with the baseline at high molecular weight.

[0030] The GPC column set is calibrated by running 20 narrow molecular weight distribution polystyrene standards. The molecular weights (MW) of the standards ranged from 266 to 12,000,000 g / mol, and the standards were contained in six "cocktail" mixtures. Each standard mixture has at least one decade of separation between the individual molecular weights. The polystyrene standards are prepared at 0.005 g in 20 mL of solvent for molecular weights equal to or greater than 1,000,000 g / mol, and 0.001 g in 20 mL of solvent for molecular weights less than 1,000,000 g / mol. The polystyrene standards are dissolved at 160 °C for 60 min with stirring. The narrow standard mixture is run first, in order of highest molecular weight components to minimize the effects of degradation. A logarithmic molecular weight calibration is generated using a fourth-order polynomial fit as a function of elution volume. The equivalent polypropylene molecular weight was calculated using the reported Mark-Houwink coefficients for polypropylene (Th. G. Scholte, NL J Meijerink, HM Schoffeleers, and AMG Brands, J. Appl. Polym. Sci., 29, 3763-3782 (1984)) and polystyrene (EPO Tocka, RJ Roe, NY Hellman, PM Muglia, Macromolecules, 4, 507 (1971)) using the following formula:

[0031]

number

[0032] [Table 1]

[0033] Izod impact strength is measured according to ASTM D256 using test specimens prepared according to ASTM D4101.

[0034] Melting points or melting temperatures and crystallization temperatures are determined using differential scanning calorimetry (DSC). The melting point is the first peak formed during the test, and typically a second peak that forms. The term "crystallinity" refers to the order of arrangement of atoms or molecules that form a crystalline structure. Polymer crystallinity can be examined using DSC. me is the temperature at which melting ends, and T max means peak melting temperature, both of which are determined by one skilled in the art from DSC analysis using data from the final heating step. One suitable method for DSC analysis uses a Model Q1000™ DSC from TA Instruments, Inc. Calibration of the DSC is performed in the following manner: A baseline is first obtained by heating the cell from -90°C to 290°C in an aluminum DSC pan without any sample. A 7 milligram fresh indium sample is then analyzed by heating the sample to 180°C, cooling the sample to 140°C at a cooling rate of 10°C / min, followed by holding the sample isothermally at 140°C for 1 minute, followed by heating the sample from 140°C to 180°C at a heating rate of 10°C / min. The heat of fusion and onset of melting of the indium sample are determined and confirmed to be within 0.5°C of 156.6°C for the onset of melting and within 0.5 J / g of 28.71 J / g for the heat of fusion. Deionized water is then analyzed by cooling a small drop of fresh sample in a DSC pan from 25 °C to -30 °C at a cooling rate of 10 °C / min. The sample is kept isothermal at -30 °C for 2 min and then heated to 30 °C at a heating rate of 10 °C / min. The onset of melting is determined and confirmed to be within 0.5 °C of 0 °C.

[0035] One method of determining the degree of crystallinity in highly crystalline polypropylene polymers is by differential scanning calorimetry (DSC). A small sample (milligram size) of the propylene polymer is sealed in an aluminum DSC pan. The sample is placed in a DSC cell with a nitrogen purge of 25 centimeters / minute and cooled to approximately -80°C. A standard thermal history is established for the sample by heating at 10°C / minute to 225°C. The sample is then cooled to approximately -80°C and reheated at 10°C / minute to 225°C. The heat of fusion (ΔH) observed in the second scan is 観察 The observed heat of fusion is related to the crystallinity, in weight percent based on the weight of the polypropylene sample, by the following formula:

[0036]

number

[0037] Alternatively, crystallinity can also be determined using the heat of crystallization upon heating (HCH) method. In the HCH method, the sample is equilibrated at 200° C. and held at that temperature for 3 minutes. After the isothermal step, data storage is turned on and the sample is ramped at 10° C. / min to −80° C. Once −80° C. is reached, data sampling is stopped and the sample is held at that temperature for 3 minutes. After the second isothermal step, data storage is turned on and the sample is ramped at 10° C. / min to 200° C.

[0038] In general, the present disclosure relates to a polymer composition or polymer material for additive manufacturing, particularly for use in a three-dimensional extrusion printing system. The present disclosure also relates to a print cartridge, a three-dimensional printing system, and a method for forming a three-dimensional article from a polymer material. In general, the polymer material or polymer composition contains a polypropylene polymer. More specifically, the polymer composition contains a polypropylene random copolymer or random terpolymer containing one or more comonomers. The comonomer can, for example, include an α-olefin comonomer, and can be ethylene, butene, or a mixture thereof.

[0039] The polymer composition of the present disclosure can be used as a polymer material in a three-dimensional printer system, particularly a printer system that uses material extrusion. For example, the polypropylene polymer of the present disclosure is specifically formulated to exhibit minimal shrinkage during melt processing, in combination with many other desirable physical properties. For example, polymer articles produced according to the present disclosure using a three-dimensional printing system exhibit little or no warping.

[0040] In addition, the polypropylene random copolymer or terpolymer of the present disclosure offers many advantages over other thermoplastic polymers, particularly those traditionally used in 3D printing, such as polylactic acid and ABS. For example, the polypropylene polymer of the present disclosure has better chemical resistance than polylactic acid and ABS polymers. Compared to polylactic acid and ABS, the polypropylene polymer of the present disclosure also exhibits better interlayer adhesion between two adjacent fused layers during the 3D printing process. In this manner, the printed article made according to the present disclosure can exhibit improved mechanical strength. The polypropylene polymer of the present disclosure also does not release volatile organic compounds during printing and is hydrophobic, preventing moisture from interfering with the printing process. The polypropylene polymer of the present disclosure is also relatively tough and exhibits higher impact resistance than polylactic acid.

[0041] In the formulation of polypropylene polymer according to the present disclosure, comonomers are introduced into the polymer chain to increase the xylene soluble content and reduce the crystallinity of the polymer. The reduced crystallinity reduces the shrinkage properties of the polymer and minimizes the warpage of the polymer article formed according to the three-dimensional printing process. The crystallinity of the polypropylene polymer can be less than about 50%, such as less than about 48%, such as less than about 46%, such as less than about 44%, such as less than about 42%, such as less than about 40%, such as less than about 38%. The crystallinity is generally greater than about 10%, such as greater than about 20%.

[0042] In one embodiment, the polypropylene random copolymer or terpolymer of the present disclosure is made using a Ziegler-Natta catalyst. Although a Ziegler-Natta catalyst, the polypropylene polymer can be formulated to have a relatively narrow molecular weight distribution. For example, narrowing the molecular weight distribution of the polymer is also believed to help control warpage issues during 3D printing. Although not known, it is believed that a narrow molecular weight distribution may provide fewer long chain molecules as nuclei in shear stress crystallization during printing, which may slow down the crystallization rate and reduce shrinkage and warpage. In addition, polypropylene polymers with a narrow molecular weight distribution may have fewer bond chains connected to the spherulites, which is believed to result in less long distance shrinkage between spherulites during cooling. For example, the polypropylene polymer of the present disclosure can have a molecular weight distribution (Mw / Mn) of less than about 10, such as less than about 8, such as less than about 6, such as less than about 4, and generally greater than about 2, such as greater than about 2.5, such as greater than about 2.8, such as greater than about 3.

[0043] The polypropylene polymer of the present disclosure may comprise a majority weight percent of propylene monomer combined with at least one comonomer. The comonomer may be one or more alpha-olefins. The comonomer may be, for example, ethylene, butene, or a combination of ethylene and butene. The total comonomer content of the polypropylene polymer is generally greater than about 3%, such as greater than about 5%, for example greater than about 8%, and generally less than about 25%, for example less than about 18%.

[0044] In one embodiment, the polypropylene polymer is a random copolymer of propylene and ethylene.The ethylene content of the random propylene-ethylene copolymer can be greater than about 3% by weight, for example greater than about 4% by weight, for example greater than about 5% by weight, for example greater than about 6% by weight, for example greater than about 7% by weight, and generally less than about 10% by weight, for example less than about 9% by weight.

[0045] Alternatively, the polypropylene polymer can be a polypropylene-butene random copolymer. The butene content of the copolymer can be greater than about 5% by weight, such as greater than about 7% by weight, such as greater than about 9% by weight, such as greater than about 11% by weight, such as greater than about 13% by weight, and generally less than about 20% by weight, such as less than about 18% by weight.

[0046] In yet another embodiment, the polypropylene polymer can be a propylene-ethylene-butene terpolymer. The terpolymer can contain ethylene in an amount of about 1% to about 10% by weight and butene in an amount of about 3% to about 20% by weight.

[0047] The polypropylene polymer of the present disclosure generally has a xylene solubles (XS) content of more than about 4.5% by weight. For example, the polypropylene polymer can have a xylene solubles content of more than about 7% by weight, such as more than about 10% by weight, such as more than about 12% by weight, such as more than about 15% by weight, such as more than about 17% by weight, such as more than about 20% by weight, such as more than about 22% by weight. The xylene solubles content is generally less than about 45% by weight, such as less than about 30% by weight.

[0048] The polypropylene polymer present in the composition can generally have a melt flow index (MFI) ranging from about 20 to about 100 g / 10 min, although polypropylenes having higher or lower melt flow indices are also encompassed herein. For example, the polypropylene polymer can have a melt flow index greater than about 25 g / 10 min, such as greater than about 30 g / 10 min, such as greater than about 35 g / 10 min, such as greater than about 40 g / 10 min. The melt flow index of the polypropylene polymer can be less than about 200 g / 10 min, such as less than about 100 g / 10 min, such as less than about 80 g / 10 min, less than about 70 g / 10 min, less than about 60 g / 10 min, less than about 55 g / 10 min.

[0049] The polypropylene polymer may be present in the polypropylene polymer composition in an amount of at least 50% by weight, such as at least 60% by weight, such as at least 70% by weight, such as at least 80% by weight, such as at least 90% by weight, such as at least 95% by weight, such as at least 96% by weight. In an embodiment, the polypropylene polymer composition may contain almost exclusively polypropylene polymer. For example, the polypropylene polymer may be present in an amount greater than about 96% by weight, such as greater than about 97% by weight, such as greater than about 98% by weight, such as greater than about 99% by weight.

[0050] In one embodiment, the polypropylene polymer of the present disclosure can be peroxide decomposed, which can increase the melt flow rate and decrease the molecular weight distribution.

[0051] Peroxide cracking is also referred to as the visbreaking process. During visbreaking, the higher molar mass chains of a polypropylene polymer are broken in relation to the lower molar mass chains. Visbreaking results in an overall decrease in the average molecular weight of the polymer and an increase in the melt flow rate. Visbreaking can produce polymers with lower molecular weight distributions or polydispersity indexes. The amount of visbreaking that occurs in a polymer can be quantified using the cracking ratio, which is calculated by dividing the final melt flow rate of the polymer by the initial melt flow rate of the polymer.

[0052] Random polypropylene copolymers can be subjected to visbreaking according to the present disclosure using peroxides as visbreaking agents. Typical peroxide visbreaking agents are 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane, 2,5-dimethyl-2,5-bis(tert-butyl-peroxy)hexane (DHBP), 2,5-dimethyl-2,5-bis(tert-butyl-peroxy)hexyne-3 (DYBP), dicumyl-peroxide (DCUP), di-tert-butyl-peroxide (DTBP), tert-butyl-cumyl-peroxide (BCUP), and bis(tert-butylperoxy-isopropyl)benzene (DIPP). The above peroxides can be used alone or in blends.

[0053] Visbreaking of the random polypropylene copolymer can be carried out during melt processing in the first extruder. For example, the random polypropylene copolymer can be fed through the extruder, and the visbreaking agent can be added to the extruder once the polymer is in a molten state. Alternatively, the visbreaking agent can be pre-blended with the polypropylene polymer. In one embodiment, for example, the visbreaking agent can be first compounded with a polymer, such as a polypropylene polymer, to form a masterbatch. The masterbatch containing the visbreaking agent can then be blended with the polypropylene polymer and fed through the extruder. In yet another embodiment, the visbreaking agent can be physically blended with the random polypropylene copolymer, such as by being absorbed onto the polymer powder. In general, any suitable extruder can be used during visbreaking. For example, the extruder can be a single screw extruder, a counter-rotating twin screw extruder, a co-rotating twin screw extruder, a planetary gear extruder, a ring extruder, or any suitable kneading device.

[0054] The amount of visbreaking agent added to the random polypropylene copolymer may depend on various factors, including the desired cracking ratio. Generally, the visbreaking agent or peroxide can be added to the random polypropylene copolymer or terpolymer in an amount of more than about 0.001% by weight, such as more than about 0.005% by weight, such as more than about 0.01% by weight, such as more than about 0.015% by weight, such as more than about 0.02% by weight, such as more than about 0.04% by weight, such as more than about 0.05% by weight, such as more than about 0.08% by weight. Generally, the visbreaking agent is added to the polypropylene polymer in an amount of less than about 0.2% by weight, such as less than about 0.15% by weight, such as less than about 0.1% by weight.

[0055] The polypropylene polymers of the present disclosure can be formed in different ways. In one embodiment, the polymers are Ziegler-Natta catalyzed. The catalyst can include, for example, a solid catalyst component, which can vary depending on the particular application.

[0056] The solid catalyst component may include (i) magnesium, (ii) a transition metal compound of an element of Groups IV-VIII of the Periodic Table, (iii) a halide, oxyhalide, and / or alkoxide of (i) and / or (ii), and (iv) a combination of (i), (ii), and (iii). Non-limiting examples of suitable catalyst components include the halides, oxyhalides, and alkoxides of magnesium, manganese, titanium, vanadium, chromium, molybdenum, zirconium, hafnium, and combinations thereof.

[0057] In one embodiment, the preparation of the catalyst component involves halogenation of mixed magnesium and titanium alkoxides.

[0058] In various embodiments, the catalyst component is a magnesium moiety compound (MagMo), a mixed magnesium titanium compound (MagTi), or a benzoic acid-containing magnesium chloride compound (BenMag). In one embodiment, the catalyst precursor is a magnesium moiety ("MagMo") precursor. The MagMo precursor comprises a magnesium moiety. Non-limiting examples of suitable magnesium moieties include anhydrous magnesium chloride and / or its alcohol adducts, magnesium alkoxides or aryloxides, mixed magnesium alkoxyhalides, and / or carboxylated magnesium dialkoxides or aryloxides. In one embodiment, the MagMo precursor is magnesium di(C 1~4 ) alkoxide. In a further embodiment, the MagMo precursor is diethoxymagnesium.

[0059] In another embodiment, the catalyst component is a mixed magnesium / titanium compound ("MagTi"). A "MagTi precursor" is a compound of the formula Mg d Ti(OR e )fX g wherein R e is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms or COR′, where R′ is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms, and each OR eThe groups are the same or different, X is independently chlorine, bromine or iodine, preferably chlorine, d is 0.5 to 56, or 2 to 4, f is 2 to 116, or 5 to 15, and g is 0.5 to 116, or 1 to 3. The precursor is prepared by controlled precipitation, removing alcohol from the reaction mixture used in its preparation. In one embodiment, the reaction medium comprises a mixture of an aromatic liquid, especially a chlorinated aromatic compound, most especially chlorobenzene, and an alkanol, especially ethanol. Suitable halogenating agents include titanium tetrabromide, titanium tetrachloride or titanium trichloride, especially titanium tetrachloride. Removal of the alkanol from the solution used for halogenation precipitates a solid precursor, which has a particularly desirable shape and surface area. Furthermore, the precursor obtained is particularly uniform in particle size.

[0060] In another embodiment, the catalyst precursor is a benzoic acid-containing magnesium chloride material ("BenMag"). As used herein, "benzoic acid-containing magnesium chloride" ("BenMag") can be a catalyst containing a benzoic acid internal electron donor (i.e., a halogenated catalyst component). The BenMag material can also include a titanium moiety, such as a titanium halide. The benzoic acid internal donor is unstable and can be replaced by other electron donors during catalyst and / or catalyst synthesis. Non-limiting examples of suitable benzoic acid groups include ethyl benzoate, methyl benzoate, ethyl p-methoxybenzoate, methyl p-ethoxybenzoate, ethyl p-ethoxybenzoate, p-chlorobenzoate. In one embodiment, the benzoate group is ethyl benzoate. In one embodiment, the BenMag catalyst component can be the product of halogenation of any catalyst component (i.e., MagMo precursor or MagTi precursor) in the presence of a benzoic acid compound.

[0061] In another embodiment, the solid catalyst component can be formed from a magnesium moiety, a titanium moiety, an epoxy compound, an organosilicon compound, and an internal electron donor. In one embodiment, an organophosphorus compound can also be incorporated into the solid catalyst component. For example, in one embodiment, a halide-containing magnesium compound can be dissolved in a mixture including an epoxy compound, an organophosphorus compound, and a hydrocarbon solvent. The resulting solution can be treated with a titanium compound in the presence of an organosilicon compound, and optionally with an internal electron donor to form a solid precipitate. The solid precipitate can then be treated with an additional amount of titanium compound. The titanium compound used to form the catalyst can have the following chemical formula: Ti(OR) g X 4-g wherein each R is independently a C1-C4 alkyl, X is Br, Cl, or I, and g is 0, 1, 2, 3, or 4.

[0062] In some embodiments, the organosilicon is a monomeric or polymeric compound. The organosilicon compound may contain -Si-O-Si- groups in one molecule or between other molecules. Other illustrative examples of organosilicon compounds include polydialkylsiloxanes and / or tetraalkoxysilanes. Such compounds may be used alone or in combination. The organosilicon compound may be used in combination with an aluminum alkoxide and an internal electron donor.

[0063] The aluminum alkoxides referred to above may have the formula Al(OR')3, where each R' is individually a hydrocarbon having up to 20 carbon atoms. This may include where each R' is individually methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, iso-pentyl, neo-pentyl, and the like.

[0064] Examples of halide-containing magnesium compounds include, for example, magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride. In one embodiment, the halide-containing magnesium compound is magnesium chloride.

[0065] Examples of epoxy compounds include, but are not limited to, glycidyl-containing compounds of the following formula:

[0066] [ka] where "a" is 1, 2, 3, 4, or 5; X is F, Cl, Br, I, or methyl; R a is H, alkyl, aryl, or cyclyl. In one embodiment, the alkyl epoxide is epichlorohydrin. In some embodiments, the epoxy compound is a haloalkyl epoxide or a non-haloalkyl epoxide.

[0067] In yet another embodiment, the substantially spherical MgCl2-nEtOH adduct may be formed by a spray crystallization process. In this process, MgCl2-nROH melt (n is 1-6) is sprayed into a vessel at a temperature of 20-80°C while introducing an inert gas into the top of the vessel. The molten droplets are transferred to a crystallization zone where an inert gas is introduced at a temperature of -50-20°C, and the molten droplets are crystallized into spherical, non-agglomerated solid particles. The spherical MgCl2 particles are then classified into desired sizes. Particles of undesired sizes can be recycled. In a preferred embodiment for catalyst synthesis, the spherical MgCl2 precursor has an average particle size (Malvern d50) between about 15-150 micrometers, preferably 20-100 micrometers, and most preferably 35-85 micrometers.

[0068] The catalyst components can be converted to solid catalysts by halogenation. Halogenation involves contacting the catalyst components with a halogenating agent in the presence of an internal electron donor. Halogenation converts the magnesium moieties present in the catalyst components to magnesium halide supports on which titanium moieties (such as titanium halides) are deposited. Without wishing to be bound by any particular theory, it is believed that during halogenation, the internal electron donor (1) adjusts the location of titanium on the magnesium-based support, (2) promotes the conversion of the magnesium and titanium moieties to their respective halides, and (3) adjusts the crystallite size of the magnesium halide support during the conversion. Thus, the provision of an internal electron donor results in a catalyst composition with improved stereoselectivity.

[0069] In one embodiment, the halogenating agent has the formula Ti(OR e ) f X h wherein R e and X is defined as above, f is an integer from 0 to 3, h is an integer from 1 to 4, and f+h is 4. In one embodiment, the halogenating agent is TiCl4. In a further embodiment, the halogenation is carried out in the presence of a chlorinated or non-chlorinated aromatic liquid, such as dichlorobenzene, o-chlorotoluene, chlorobenzene, benzene, toluene, or xylene. In yet another embodiment, the halogenation is carried out by use of a mixture of a halogenating agent and a chlorinated aromatic liquid, the mixture comprising 40 to 60 volume percent of the halogenating agent, such as TiCl4.

[0070] In one embodiment, the resulting solid catalyst composition has a titanium content of about 1.0 weight percent to about 6.0 weight percent, or about 1.5 weight percent to about 4.5 weight percent, or about 2.0 weight percent to about 3.5 weight percent based on the total solids weight. The weight ratio of titanium to magnesium in the solid catalyst composition is preferably about 1:3 to about 1:160, or about 1:4 to about 1:50, or about 1:6 to 1:30. In one embodiment, the internal electron donor may be present in the catalyst composition in a molar ratio of internal electron donor to magnesium of about 0.005:1 to about 1:1, or about 0.01:1 to about 0.4:1. The weight percentages are based on the total weight of the catalyst composition.

[0071] As described above, the catalyst composition may include a combination of a magnesium moiety, a titanium moiety, and an internal electron donor. The catalyst composition is produced by the halogenation procedure described above, which converts the catalyst component and the internal electron donor into a combination of a magnesium moiety and a titanium moiety incorporating an internal electron donor. The catalyst component from which the catalyst composition is formed may be any of the catalyst precursors described above, including a magnesium moiety precursor, a mixed magnesium / titanium precursor, a benzoate-containing magnesium chloride precursor, a magnesium, titanium, epoxy, and phosphorus precursor, or a spherical precursor.

[0072] A variety of different types of internal electron donors may be incorporated into the solid catalyst component. In one embodiment, the internal electron donor is an aryl diester, such as a phenylene substituted diester. In one embodiment, the internal electron donor may have the following chemical structure:

[0073] [ka] In the formula, R1, R2, R3, and R4 are each a hydrocarbyl group having 1 to 20 carbon atoms, the hydrocarbyl group having a branched or linear structure or including a cycloalkyl group having 7 to 15 carbon atoms; E1 and E2 may be the same or different and are selected from the group consisting of an alkyl having 1 to 20 carbon atoms, a substituted alkyl having 1 to 20 carbon atoms, an aryl having 1 to 20 carbon atoms, a substituted aryl having 1 to 20 carbon atoms, or an inert functional group having 1 to 20 carbon atoms and optionally containing a heteroatom; X1 and X2 are each O, S, an alkyl group, or NR5, and R5 is a hydrocarbyl group having 1 to 20 carbon atoms or hydrogen.

[0074] As used herein, the terms "hydrocarbyl" and "hydrocarbon" refer to substituents containing only hydrogen and carbon atoms, including branched or unbranched, saturated or unsaturated, cyclic, polycyclic, fused, or acyclic species, and combinations thereof. Non-limiting examples of hydrocarbyl groups include alkyl, cycloalkyl, alkenyl, alkadienyl, cycloalkenyl, cycloalkadienyl, aryl, aralkyl, alkylaryl, and alkynyl groups.

[0075] As used herein, the terms "substituted hydrocarbyl" and "substituted hydrocarbon" refer to a hydrocarbyl group substituted with one or more non-hydrocarbyl substituents. A non-limiting example of a non-hydrocarbyl substituent is a heteroatom. As used herein, "heteroatom" refers to an atom other than carbon or hydrogen. A heteroatom can be a non-carbon atom from Groups IV, V, VI, and VII of the periodic table. Non-limiting examples of heteroatoms include halogens (F, Cl, Br, I), N, O, P, B, S, and Si. Substituted hydrocarbyl groups also include halohydrocarbyl groups and silicon-containing hydrocarbyl groups. As used herein, the term "halohydrocarbyl" group refers to a hydrocarbyl group substituted with one or more halogen atoms. As used herein, the term "silicon-containing hydrocarbyl group" is a hydrocarbyl group substituted with one or more silicon atoms. The silicon atom may or may not be in the carbon chain.

[0076] In one embodiment, the substituted phenylenediester has the following structure (I):

[0077] [ka]

[0078] In one embodiment, structure (I) includes R1 and R3 that are isopropyl groups. R2, R4, and R5 through R 14 Each of is hydrogen.

[0079] In one embodiment, structure (I) includes each of R1 and R4 as a methyl group, and R3 is a cycloalkyl group, such as a cyclohexyl group. 14 Each of is hydrogen.

[0080] In one embodiment, structure (I) comprises R, R, and R 10 R2, R4, R6 to R9, and R 11 ~R 14Each of is hydrogen.

[0081] In one embodiment, structure (I) comprises R, R, and R 12 R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0082] In one embodiment, structure (I) includes R1 as a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0083] In one embodiment, structure (I) is selected from the group consisting of R1, R5, R7, R9, R 10 , R 12 , and R 14 R2, R4, R6, R8, R 11 , and R 13 Each of is hydrogen.

[0084] In one embodiment, structure (I) includes R1 as a methyl group and R3 is a t-butyl group. 10 , R 12 , and R 14 Each of R2, R4, R6, R8, R 11 , and R 13 Each of is hydrogen.

[0085] In one embodiment, the substituted phenylene aromatic diester is selected from the group consisting of R1-R2, as described in detail in U.S. Pat. No. 8,536,372, which is incorporated herein by reference. 14 The compound has a structure selected from the group consisting of structures (II)-(V), including alternatives of each of the following:

[0086] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0087] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0088] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0089] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0090] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0091] In one embodiment, structure (I) comprises R1 being a methyl group and R3 being a t-butyl group. 11 , and R 12 Each of R2, R4, R5, R8, R9, R 10 , R 13 , and R 14 Each of is hydrogen.

[0092] In one embodiment, structure (I) comprises R1 being a methyl group and R3 being a t-butyl group. 11 , and R 13 Each of R2, R4, R5, R7, R9, R 10 , R 12 , and R 14 Each of is hydrogen.

[0093] In one embodiment, structure (I) includes R1 which is a methyl group, and R3 is a t-butyl group. 14 Each of is a fluorine atom.

[0094] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0095] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0096] In one embodiment, R1 is a methyl group and R3 is a t-butyl group.12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0097] In one embodiment, structure (I) includes R1 which is a methyl group and R3 is a t-butyl group. 12 Each of R2, R4, R5, R6, R8, R9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0098] In one embodiment, structure (I) includes R1 which is a methyl group, and R3 is a 2,4,4-trimethylpentan-2-yl group. 14 Each of is hydrogen.

[0099] In one embodiment, structure (I) comprises R1 and R3, each of which is a sec-butyl group. R2, R4, and R5 through R 14 Each of is hydrogen.

[0100] In one embodiment, structure (I) includes R1 and R4, each of which is a methyl group. R2, R3, R5-R9, and R 10 ~R 14 Each of is hydrogen.

[0101] In one embodiment, structure (I) includes R1 which is a methyl group. R4 is an i-propyl group. R2, R3, R5-R9, and R 10 ~R 14 Each of is hydrogen.

[0102] In one embodiment, structure (I) includes R1, R3, and R4, each of which is an i-propyl group. R2, R5-R9, and R 10 ~R 14 Each of is hydrogen.

[0103] In addition to the above solid catalyst component, the catalyst system of the present disclosure can also include a cocatalyst. The cocatalyst can include hydrides of aluminum, lithium, zinc, tin, cadmium, beryllium, magnesium, alkyl, or aryl, and combinations thereof. In one embodiment, the cocatalyst is a hydrocarbyl aluminum cocatalyst represented by the formula R3Al, where each R is an alkyl, cycloalkyl, aryl, or hydride radical, at least one R is a hydrocarbyl radical, and two or three R radicals can be joined to a cyclic radical to form a heterocyclic structure, each R can be the same or different, and each R, which is a hydrocarbyl radical, has 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. In further embodiments, each alkyl radical can be linear or branched, and such hydrocarbyl radicals can be mixed radicals, i.e., the radicals can contain alkyl, aryl, and / or cycloalkyl groups. Non-limiting examples of suitable radicals are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, n-hexyl, 2-methylpentyl, n-heptyl, n-octyl, isooctyl, 2-ethylhexyl, 5,5-dimethylhexyl, n-nonyl, n-decyl, isodecyl, n-undecyl, n-dodecyl.

[0104] Non-limiting examples of suitable hydrocarbyl aluminum compounds are: triisobutylaluminum, tri-n-hexylaluminum, diisobutylaluminum hydride, di-n-hexylaluminum hydride, isobutylaluminum dihydride, n-hexylaluminum dihydride, diisobutylhexylaluminum, isobutyldihexylaluminum, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, tri-n-octylaluminum, tri-n-decylaluminum, tri-n-dodecylaluminum. In one embodiment, the cocatalyst is selected from triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diisobutylaluminum hydride, and di-n-hexylaluminum hydride.

[0105] In one embodiment, the cocatalyst is triethylaluminum. The molar ratio of aluminum to titanium is from about 5:1 to about 500:1, or from about 10:1 to about 200:1, or from about 15:1 to about 150:1, or from about 20:1 to about 100:1. In another embodiment, the molar ratio of aluminum to titanium is about 45:1.

[0106] Suitable catalyst compositions can include a solid catalyst component, a cocatalyst, and an external electron donor, which can be a mixed external electron donor (M-EED) of two or more different components. Suitable external electron donors or "external donors" include one or more activity limiting agents (ALA) and / or one or more selectivity control agents (SCA). As used herein, an "external donor" is a composition that includes a component or mixture of components that are added independently of the procatalyst formation that modifies the catalyst performance. As used herein, an "activity limiting agent" is a composition that reduces the catalyst activity in the presence of the catalyst as the polymerization temperature increases above a threshold temperature (e.g., a temperature above about 95°C). A "selectivity control agent" is a composition that improves the tacticity of the polymer, where improved tacticity is generally understood to mean increased tacticity or decreased xylene solubles, or both. It should be understood that the above definitions are not mutually exclusive and that a single compound may, for example, be classified as both an activity limiting agent and a selectivity controlling agent.

[0107] The selectivity control agent according to the present disclosure is generally an organosilicon compound. For example, in one embodiment, the selectivity control agent can be an alkoxysilane.

[0108] In one embodiment, the alkoxysilane may have the following general formula: SiR(OR')4-m(I), where R, independently at each occurrence, is hydrogen or a hydrocarbyl or amino group optionally substituted with one or more substituents containing one or more Group 14, 15, 16, or 17 heteroatoms, R' contains up to 20 atoms excluding hydrogen and halogens, R' is a C1-4 alkyl group, and m is 0, 1, 2, or 3. In one embodiment, R is C 6-12 Aryl, alkyl or aralkyl, C 3-12 Cycloalkyl, C 3-12 Branched alkyl, or C 3-12 is a cyclic or acyclic amino group, R' is C 1-4Alkyl, and m are 1 or 2. In one embodiment, for example, the second selectivity control agent can include n-propyltriethoxysilane. Other selectivity control agents that can be used include propyltriethoxysilane or diisobutyldimethoxysilane.

[0109] In one embodiment, the catalyst system can include an activity limiting agent (ALA). The ALA inhibits or otherwise prevents polymerization reactor failure and ensures the continuation of the polymerization process. Typically, the activity of Ziegler-Natta catalysts increases as the reactor temperature increases. Ziegler-Natta catalysts also typically maintain high activity near the melting point temperature of the produced polymer. The heat generated by the exothermic polymerization reaction can cause the polymer particles to form agglomerates, which can ultimately lead to interruption of the continuation of the polymer production process. The ALA reduces the catalyst activity at high temperatures, thereby preventing reactor failure and reducing (or preventing) particle agglomeration, ensuring the continuation of the polymerization process.

[0110] The activity limiting agent may be a carboxylic acid ester. The aliphatic carboxylic acid ester may be a C4-C 30 It may be an aliphatic acid ester, may be a mono- or poly(two or more) ester, may be linear or branched, may be saturated or unsaturated, and any combination thereof. 30 The aliphatic acid esters may also be substituted with one or more group 14, 15, or 16 heteroatom-containing substituents. 30 Non-limiting examples of aliphatic acid esters include aliphatic C 4~30 Monocarboxylic acid C 1~20 Alkyl ester, aliphatic C 8~20 Monocarboxylic acid C 1~20 Alkyl ester, aliphatic C 4~20 Monocarboxylic and dicarboxylic acids C 1~4 Allyl mono- and diesters, aliphatic C 8~20 Monocarboxylic and dicarboxylic acids C 1~4 Alkyl esters, and C 2~100 (Poly)glycol or C2~100 In a further embodiment, the C4-C mono- or polycarboxylate derivatives of (poly)glycol ethers are included. 30 The fatty acid esters include laurate, myristate, palmitate, stearate, oleate, sebacate, (poly)(alkylene glycol) mono- or diacetate, (poly)(alkylene glycol) mono- or dimyristate, (poly)(alkylene glycol) mono- or dilaurate, (poly)(alkylene glycol) mono- or dioleate, glyceryl tri(acetate), C 2~40 In a further embodiment, the glyceryl tri-esters of aliphatic carboxylic acids may be C4-C 30 The aliphatic ester is isopropyl myristate, di-n-butyl sebacate, or pentyl valerate.

[0111] The catalyst system of the present disclosure as described above can be used to produce olefin-based polymers. The process comprises contacting an olefin with the catalyst system under polymerization conditions.

[0112] The polypropylene random copolymers and terpolymers made according to the present disclosure can then be incorporated into various polymer compositions to produce feedstock having a size and shape configured to be fed into a three-dimensional printing system. The feedstock may be in the form of polymer pellets, polymer rods, or continuous filaments. The polymer compositions used to produce the filaments can contain polypropylene polymer alone or in combination with various other additives and ingredients.

[0113] For example, in one embodiment, the polymer composition can contain one or more antioxidants. The filler can be, for example, a non-organic filler. Fillers that can be contained in the polymer composition include talc particles, calcium carbonate particles, glass fibers, metals and alloys, or mixtures thereof. One or more fillers can be included in the polymer composition in an amount greater than about 0% by weight, such as greater than about 2% by weight, such as greater than about 5% by weight, typically less than about 40% by weight, such as less than about 20% by weight, such as less than about 10% by weight, such as less than about 8% by weight, such as less than about 6% by weight.

[0114] In one embodiment, the polymer composition may contain a primary antioxidant, a secondary antioxidant (e.g., a phosphite), and an antacid (e.g., CaSt or ZnO). In one embodiment, the antioxidant has anti-gas fade properties, such as Irganox 3114, Cyanox 1790, or Irganox 1425WL. Alternatively, the antioxidant system may be non-gas fade, i.e., may not contain a phenolic antioxidant, and may be based on a combination of HALS (hindered amine light stabilizers) with either / both a hydroxylamine stabilizer (e.g., Irganox FS042) and a phosphite secondary antioxidant. The antioxidant may minimize oxidation of the polymer components and organic additives in the polymer blend. The polymer composition may contain, for example, a phosphite and / or phosphonate antioxidant, alone or in combination with other antioxidants. Non-limiting examples of suitable antioxidants include phenols such as 2,6-di-t-butyl-4-methylphenol, 1,3,5-trimethyl-2,4,6-tris(3'5'-di-t-butyl-4'-hydroxybenzyl)benzene, tetrakis[(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, acryloyl modified phenols, octadecyl-3,5-di-t-butyl-4-hydroxycinnamate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (e.g., Irganox 3114 supplied by BASF), calcium-bis(((3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl)-ethylphosphonate) ... 1425WL). Another antioxidant that can be used is 1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[[4-(1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl] (e.g., Cyanox 1790 from Solvay). In another embodiment, the antioxidant can be N,N-dioctadecylhydroxylamine (e.g., FS042).Phosphites and phosphonites may generally be used in combination with the hindered phenols described above. Hydroxylamines may generally be used in combination with hindered amine light stabilizers or phosphites. Other antioxidants include benzofuranone derivatives, and combinations thereof.

[0115] The polymer composition may also contain an antacid that acts as an acid scavenger. The antacid may be a stearate, a metal oxide, hydrotalcite, magnesium aluminum carbonate hydroxide, or a mixture thereof. Examples of specific antacids include calcium stearate, zinc stearate, magnesium oxide, zinc oxide, and mixtures thereof.

[0116] In some embodiments, the polymer composition may include a lubricant. Non-limiting examples of suitable lubricants include fatty alcohols and their dicarboxylic acid esters, fatty acid esters of short chain alcohols, fatty acids, fatty acid amides, metal soaps, oligomeric fatty acid esters, fatty acid esters of long chain alcohols, montan wax, polyethylene wax, polypropylene wax, natural and synthetic paraffin wax, and combinations thereof. One embodiment of a fatty acid amide lubricant that may be used is N,N'-ethylene bisstearamide. Various stearates may also function as lubricants when included in sufficient amounts. For example, higher levels of metal stearates, such as zinc stearate, may function as internal lubricants.

[0117] The polymer composition may also contain a processing aid. One example of a processing aid is a fluorocarbon polymer. For example, the composition may contain polytetrafluoroethylene particles. The processing aid may be present in an amount of about 0% to about 5% by weight, for example about 0.01% to about 1.5% by weight.

[0118] In some embodiments, the polymer composition may optionally include a stabilizer that may prevent or reduce degradation of the polymer blend by UV radiation. Non-limiting examples of suitable UV stabilizers include benzophenones, hindered amines, benzotriazoles, aryl esters, oxanilides, acrylic esters, formamidines, carbon black, nickel quenchers, phenolic antioxidants, metal salts, zinc compounds, and combinations thereof.

[0119] In one aspect, the polymer composition can also contain one or more colorants. The colorants can be dyes or pigments. In one embodiment, a blend of colorants can be used to produce filaments having a particular color.

[0120] In one embodiment, the polymer composition can contain a nucleating agent. If utilized, the nucleating agent is not particularly limited. In one embodiment, the nucleating agent may be selected from the group of phosphorus-based nucleating agents, such as the phosphate ester metal salt represented by the following structure (VIII).

[0121] [ka] In the formula, R1 is oxygen, sulfur, or a hydrocarbon group having 1 to 10 carbon atoms, R2 and R3 are each hydrogen, or a hydrocarbon or hydrocarbon group having 1 to 10 carbon atoms, R2 and R3 may be the same or different, two R2s, two R3s, or R2 and R3 may be bonded to each other to form a ring, M is a monovalent to trivalent metal atom, n is an integer of 1 to 3, and m is either 0 or 1, with the proviso that n>m.

[0122] Examples of α-nucleating agents represented by the above formula include sodium-2,2'-methylene-bis(4,6-di-t-butyl-phenyl)phosphate, sodium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl)-phosphate, lithium-2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate, lithium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis(4-i-propyl-6-t-butylphenyl)phosphate, lithium-2,2 '-Methylene-bis(4-methyl-6-t-butylphenyl)phosphate, lithium-2,2'-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate, calcium-bis[2,2'-thiobis(4-methyl-6-t-butylphenyl)-phosphate], calcium-bis[2,2'-thiobis(4-ethyl-6-t-butylphenyl)-phosphate], calcium-bis[2,2'-thiobis(4,6-di-t-butylphenyl)phosphate], magnesium-bis[2,2'-thiobis(4,6-di-t-butylphenyl)phosphate] nyl) phosphate], magnesium bis[2,2'-thiobis(4-t-octylphenyl) phosphate], sodium 2,2'-butylidene-bis(4,6-dimethylphenyl) phosphate, sodium 2,2'-butylidene-bis(4,6-di-t-butyl-phenyl) phosphate, sodium 2,2'-t-octylmethylene-bis(4,6-dimethyl-phenyl) phosphate, sodium 2,2'-t-octylmethylene-bis(4,6-di-t-butylphenyl) phosphate, calcium bis[2,2'- methylene-bis(4,6-di-t-butylphenyl)-phosphate], magnesium-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)-phosphate], barium-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)-phosphate], sodium-2,2'-methylene-bis(4-methyl-6-t-butylphenyl)-phosphate, sodium-2,2'-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate, sodium (4,4'-dimethyl-5,6'-di-t-butyl-2,2'-biphenyl) phosphate, calcium-bis-[(4,4'-dimethyl-6,6'-di-t-butyl-2,2'-biphenyl) phosphate], sodium-2,2'-ethylidene-bis(4-m-butyl-6-t-butyl-phenyl) phosphate, sodium-2,2'-methylene-bis-(4,6-di-methylphenyl)-phosphate, sodium-2,2'-methylene-bis(4,6-di-t-ethyl-phenyl) phosphate, potassium-2,2'-ethylidene-bis(4,6-di-t-butylphenyl)-phosphate, calcium -bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)-phosphate], magnesium-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)-phosphate], barium-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)-phosphate], aluminum-hydroxy-bis[2,2'-methylene-bis(4,6-di-t-butyl-phenyl)phosphate], aluminum-tris[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)-phosphate].

[0123] A second group of phosphorus-based nucleating agents includes, for example, aluminum-hydroxy-bis[2,4,8,10-tetrakis(1,1-dimethylethyl)-6-hydroxy-12H-dibenzo-[d,g]-dioxa-phosphocin-6-oxidato] and blends thereof with lithium myristate or lithium stearate.

[0124] Other examples of nucleating agents include, but are not limited to, sorbitol-based nucleating agents (e.g., 1,3:2,4 dibenzylidene sorbitol, 1,3:2,4 di(methylbenzylidene)sorbitol, 1,3:2,4 di(ethylbenzylidene)sorbitol, 1,3:2,4 bis(3,4-dimethylbenzylidene)sorbitol, etc.), pine rosin, polymeric nucleating agents (e.g., vinylcycloalkane polymers, vinylalkane polymers, partial metal salts of rosin acid, etc.), talc, sodium benzoate, etc.

[0125] Commercially available examples of nucleating agents include, but are not limited to, ADK STAB NA-11, ADK STAB NA-21, ADK STAB NA-21 E, ADK STAB NA-21 F, and ADK STAB NA-27 available from Asahi Denka Kokai; Millad NX8000, Millad 3988, Millad 3905, Millad 3940, Hyperform HPN-68L, Hyperform HPN-715, and Hyperform HPN-20E available from Milliken & Company; and Irgaclear XT 386 manufactured by Ciba Specialty Chemicals.

[0126] In one embodiment, the nucleating agent may include a sorbitol compound, such as a sorbitol acetal derivative. In one embodiment, for example, the nucleating agent may include dibenzyl sorbitol.

[0127] With respect to sorbitol acetal derivatives that can be used as additives in some embodiments, the sorbitol acetal derivatives are shown in structure (IX).

[0128] [ka] wherein R1-R5 comprise the same or different moieties selected from hydrogen and C1-C3 alkyl.

[0129] In some embodiments, R1-R5 are hydrogen, such that the sorbitol acetal derivative is 2,4-dibenzylidene sorbitol ("DBS"). In some embodiments, R1, R4, and R5 are hydrogen, and R2 and R3 are methyl groups, such that the sorbitol acetal derivative is 1,3:2,4-di-p-methyldibenzylidene-D-sorbitol ("MDBS"). In some embodiments, R1-R4 are methyl groups, and R5 is hydrogen, such that the sorbitol acetal derivative is 1,3:2,4-bis(3,4-dimethylobenzylideno)sorbitol ("DMDBS"). In some embodiments, R2, R3, and R5 are propyl groups (-CH2-CH2-CH3), and R1 and R4 are hydrogen, such that the sorbitol acetal derivative is 1,2,3-trideoxy-4,6:5,7-bis-O-(4-propylphenylmethylene)nonitol ("TBPMN").

[0130] Other examples of nucleating agents that can be used include, but are not limited to, 1,3:2,4-dibenzylidene sorbitol, 1,3:2,4-bis(p-methylbenzylidene)sorbitol, di(p-methylbenzylidene)sorbitol, di(p-ethylbenzylidene)sorbitol, bis(5',6',7',8'-tetrahydro-2-naphthylidene)sorbitol, bisamides such as benzenetrisamide, and any combination of nucleating agents.

[0131] When present in the polymer composition, the one or more nucleating agents are generally added in an amount greater than about 0 ppm, such as greater than about 200 ppm, such as greater than about 1,800 ppm, such as greater than about 2,000 ppm, such as greater than about 2,200 ppm. The one or more nucleating agents are generally present in an amount less than about 20,000 ppm, such as less than about 15,000 ppm, such as less than about 10,000 ppm, such as less than about 8,000 ppm, such as less than about 5,000 ppm.

[0132] Once the polymer composition has been formulated, it can be melt processed into a feedstock. The feedstock can include polymer pellets or polymer rods. In one embodiment, the feedstock can include an extruded filament. The feedstock can be incorporated into a printer cartridge that is easily adapted for incorporation into a three-dimensional printer system.

[0133] For example, referring to Figure 2, one embodiment of a printer cartridge 10 is shown. For purposes of illustration only, the cartridge 10 shown in Figure 2 is particularly adapted to receive a polymer filament as a feedstock. The printer cartridge 10 includes, for example, a spool 12. When the polymer composition of the present disclosure is in the form of a filament, the filament may be wound around the spool 12. The spool 12 may define a central bore that fits around an axis 14 within the printer cartridge 10.

[0134] As shown in FIG. 2, although not required, the spool 12 may be enclosed within a housing 16 that protects the filament from the outside environment prior to use.

[0135] Printer cartridge 10 can have a shape and configuration that is well suited for use with a particular type of printing system. In one embodiment, for example, printer cartridge 10 can include an identification device 18 that allows a printer system to identify the printer cartridge. Identification device 18 can include a machine-readable component, such as, for example, a machine-readable chip.

[0136] As mentioned above, the polymer compositions of the present disclosure are particularly well suited for use in producing articles by three dimensional printers.

[0137] Generally speaking, the present disclosure may utilize any of a variety of three-dimensional printer systems to produce three-dimensional articles. Referring to FIG. 1, an embodiment of an extrusion-based three-dimensional printer system 30 is shown, which may be configured to receive a printer cartridge 10, for example, as shown in FIG. 2. The printer system 30 includes a pair of feed rollers 32 that engage a polymeric material 34. The polymeric material 34 is made from a polymeric composition of the present disclosure. In this embodiment, the polymeric material 34 is in the form of a filament. The feed rollers 32 may rotate clockwise and / or counterclockwise at a desired speed to feed and retract the filament 34 in very precise amounts to a downstream process. The filament 34 is fed from the feed rollers 32 to a heater 36 located upstream of a nozzle 38. The heater 36 melts the filament to a usable temperature. The nozzle 38 extrudes the filament 34 onto a platform 40. Generally, the polymeric material 34 exits the nozzle 38 with a smaller diameter than the filament fed to the nozzle. The nozzle 38 and / or platform 40 are then moved in a pattern to build the three-dimensional article layer by layer, in one embodiment, the nozzle 38 and / or platform 40 are moved not only in the X and Y planes, but also in the Z plane.

[0138] The printing system 30 can also include a controller 42, which may comprise one or more programmable devices or microprocessors. The controller 42 can store a particular pattern and then control the printing system 30 to deposit the polymer material on the platform 40 in a desired manner to form the three-dimensional article 50.

[0139] During the printing process, the polymeric material 34 is heated to a molten state, as shown in Figure 1. The filament is deposited layer by layer onto the platform 40, thermally bonding with each successive layer.

[0140] The present disclosure may be better understood with reference to the following examples. EXAMPLES

[0141] Twelve different polypropylene polymers were formed into filaments and tested using a 3D printer. The 12 different samples, including the polymer's chemical composition and various properties, are listed in the table below (samples No. 1-12). Sample No. 13 represents a commercially available polypropylene filament for 3D printing.

[0142] [Table 2] Note: Et in sample number 13 is 13 C-NMR and all others were tested by FTIR. Sample #13 was tested for XS content by the wet method and all others were tested by the Viscotek FIPA method.

[0143] Three-dimensional (3D) printing filaments were extruded from the sample pellets on a Wellzoom B2 desktop filament extruder equipped with a Wellzoom automatic winder. The filament diameter was controlled to 1.75 mm ± 0.05 mm.

[0144] The 3D printing process was completed on a Creality 3D Ender 2 3D printer. The printed part has three model targets for different testing purposes (see Figures 3 and 4, dimensions (mm)).

[0145] Warpage test: Test bars (Fig. 3) with thin thickness (z-direction during printing) were designed to test the warpage height. As shown in Fig. 3, the model with square center is model number 1, and the model with circular center is model number 2. The warpage height is the distance measured from the center of the test bar to the substrate when the test bar is placed upside down. A higher warpage height represents a more severe warpage.

[0146] Bulk shrinkage test: A test cube (Figure 4) with a large thickness (z-direction during printing) was designed to test the bulk shrinkage. A 3D model of the cube is shown in Figure 4. Taking into account the bottom deformation, surface finish and top seal, the printed cubes were given different scores scaled from 1 to 5 (1 being the worst and 5 being the best). The total score is on a scale of 0 to 15 and is the sum of the three scores mentioned above.

[0147] During 3D printing, the nozzle diameter was set to 0.4 mm, the nozzle temperature was set to 230° C., the layer thickness was set to 0.3 mm, and the bed temperature was set to 60° F. The bed material used was a pressure sensitive polypropylene tape used for adhesion to the article as it was being formed. The print speed was 2,400 mm / min. The contour speed was set to 50%, the first layer speed was set to 20%, and the height was set to 90%. The bleed control shrinkage was disabled and the interior fill percentage was set to 20%.

[0148] The following results were obtained.

[0149] [Table 3]

[0150] Based on the warp height from the warp test (smaller warp height is preferred) and the total score from the bulk shrinkage test (higher score is preferred), sample No. 1 exhibits the best printing performance.

[0151] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art without departing from the spirit and scope of the present invention, which is particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged in whole or in part. Moreover, those skilled in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention as further set forth in such appended claims.

[0152] The present technology is also not limited with respect to the specific embodiments described herein, which are intended as single illustrations of individual embodiments of the technology. As will be apparent to those skilled in the art, many modifications and variations of the present technology can be made without departing from its spirit and scope. Functionally equivalent methods within the scope of the present technology will be apparent to those skilled in the art from the foregoing description, in addition to those recited herein. Such modifications and variations are intended to fall within the scope of the appended claims. It is to be understood that the present technology is not limited to specific methods, reagents, compounds, compositions, labeled compounds, or biological systems, which may of course vary. It is also to be understood that the terms used herein are merely for the purpose of describing particular embodiments, and are not intended to be limiting. Thus, it is intended that the specification be considered as exemplary only, with the breadth, scope, and spirit of the present technology as indicated solely by the appended claims, the definitions therein, and any equivalents thereof.

[0153] The embodiments illustratively described herein may be suitably practiced in the absence of any element or elements, limitations or limitations not specifically disclosed herein. Thus, for example, terms such as "comprising", "including", "containing" and the like should be read expansively and without limitation. In addition, the terms and expressions used herein are used as terms of description and not of limitation, and in the use of such terms and expressions, there is no intention to exclude any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. In addition, the phrase "consisting essentially of" will be understood to include those elements specifically recited, as well as those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase "consisting of" excludes any elements not specified.

[0154] In addition, where features or aspects of the disclosure are described in terms of a Markush group, one of skill in the art will recognize that the disclosure is thereby also described in terms of any individual members or subgroups of members of the Markush group. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a condition or negative limitation removing any subject matter from the genus, regardless of whether the omitted material is specifically recited herein.

[0155] As will be understood by those skilled in the art, for all and all purposes, especially in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations thereof. Any ranges recited are fully described and can be readily recognized as being at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range recited herein can be readily broken down into a lower third, middle third, upper third, etc. Also, as will be understood by those skilled in the art, all terms such as "up to," "at least," "greater than," "less than," etc. refer to ranges that are inclusive of the recited numbers and can be subsequently broken down into subranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual member.

[0156] All publications, patent applications, issued patents, and other documents (e.g., journals, articles, and / or textbooks) referenced herein are incorporated by reference herein to the same extent as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions contained in the descriptions incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

[0157] It is understood that the present technology may include, but is not limited to, the features and combinations of features recited in the following lettered paragraphs, and that the following paragraphs are not to be construed as limiting the scope of the claims appended hereto or as dictating that all such features must necessarily be included within the scope of such claims. A. A polymeric material for a three dimensional extrusion printing system, the polymeric material comprising a feedstock having a size and shape suitable for feeding into a three dimensional printing system, the feedstock comprising a polymeric composition, the polymeric composition comprising a polypropylene polymer in an amount greater than about 60% by weight, the polypropylene polymer comprising a polypropylene random copolymer or terpolymer, the polypropylene polymer having a melt flow rate of about 20 g / 10 min to about 200 g / 10 min, As the main monomer, propylene containing at least one comonomer of ethylene or butene; a total comonomer content of about 3% by weight to about 25% by weight; It has an ethylene content of 0% to about 10% by weight, a butene content of 0% to about 20% by weight, and a xylene solubles content of about 4.5% to about 45% by weight. B. The polymeric material of paragraph A, wherein the feedstock comprises filaments, the filaments having a filament diameter of from about 0.5 mm to about 5 mm, for example, from about 1 mm to about 4 mm. C. The polymeric material of paragraph A, wherein the feedstock comprises polymeric pellets or polymeric rods. D. The polymeric material of any one of paragraphs A-C, wherein the polypropylene polymer comprises a copolymer of propylene and ethylene having an ethylene content of about 3% to about 10% by weight. E. The polymeric material of any one of paragraphs A-D, wherein the polypropylene polymer comprises a copolymer of propylene and ethylene having an ethylene content of about 5% to about 9% by weight. F. The polymeric material of any one of paragraphs A-E, wherein the polypropylene polymer comprises a copolymer of propylene and butene having a butene content of about 5% to about 20% by weight. G. The polymeric material of any one of paragraphs A-F, wherein the polypropylene polymer comprises a propylene, ethylene, and butene terpolymer. H. The polymeric material of any one of paragraphs A-G, wherein the polypropylene polymer has a xylene content of from about 5% to about 40% by weight, for example from about 10% to about 30% by weight. I. The polymeric material of any one of paragraphs A-H, wherein the polypropylene polymer has a crystallinity of less than about 50%, for example less than about 40%. J. The polymeric material of any one of paragraphs A-I, wherein the polypropylene polymer has a molecular weight distribution (Mw / Mn) of from about 2.5 to about 10, for example, from about 3 to about 6. K. The polymeric material of any one of paragraphs A-J, wherein the polymeric composition further comprises a filler. L. The polymeric material of paragraph K, wherein the filler comprises talc, calcium carbonate, glass fiber, or a mixture thereof. M. The polymeric material of paragraph K or paragraph L, wherein the filler is present in the polymeric composition in an amount from about 0% to about 40% by weight. N. The polymeric material of any one of paragraphs A through M, wherein the polypropylene polymer is Ziegler-Natta catalyzed using a non-phthalate catalyst. O. The polymeric material of any one of paragraphs A-N, wherein the polypropylene polymer is present in the polymeric composition in an amount greater than about 70% by weight, such as greater than about 80% by weight, for example greater than about 90% by weight, and generally less than about 99% by weight, for example less than about 96% by weight. P. The polymeric material of any one of paragraphs A-O, wherein the polymeric composition further comprises a nucleating agent. Q. The polymeric material of any one of paragraphs A-P, wherein the polymeric composition further comprises a processing aid. R. A printer cartridge for a three dimensional extrusion printing system comprising the polymeric material of any one of paragraphs A-Q. S. The printer cartridge of paragraph R, wherein the polymeric material includes a filament, the filament being wound around a spool within the printer cartridge. T. A three dimensional printing system comprising a three dimensional printing device and a printer cartridge according to paragraph R or paragraph S. U. A three-dimensional article formed from the polymeric material of any one of paragraphs A-Q. V. The three-dimensional article of paragraph U, wherein the article is formed layer-by-layer from a polymeric material. W. A method of producing a three-dimensional article, comprising selectively forming a three-dimensional structure from a polymeric material according to any one of paragraphs A-Q.

[0158] Other embodiments are set forth in the following claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. 1. A polymeric material for a three dimensional extrusion printing system, the polymeric material comprising a feedstock having a size and shape suitable for feeding into a three dimensional printing system, the feedstock being comprised of a polymeric composition, the polymeric composition comprising a polypropylene polymer in an amount greater than about 60% by weight, the polypropylene polymer comprising a polypropylene random copolymer or terpolymer, the polypropylene polymer having a melt flow rate of about 20 g / 10 min to about 200 g / 10 min, the polypropylene polymer comprising: As the main monomer, propylene containing at least one comonomer of ethylene or butene; a total comonomer content of about 3% to about 25% by weight; an ethylene content of 0% to about 10% by weight; a butene content of from 0% to about 20% by weight; and a xylene solubles content of about 4.5% to about 45% by weight.

2. 10. The polymeric material of claim 1, wherein the feedstock comprises filaments, the filaments having a filament diameter of about 0.5 mm to about 5 mm.

3. The polymeric material of claim 1 , wherein the feedstock comprises polymeric pellets or polymeric rods.

4. 10. The polymeric material of claim 1, wherein the polypropylene polymer comprises a copolymer of propylene and ethylene having an ethylene content of about 3% to about 10% by weight.

5. 10. The polymeric material of claim 1, wherein the polypropylene polymer comprises a copolymer of propylene and ethylene having an ethylene content of about 5% to about 9% by weight.

6. 10. The polymeric material of claim 1, wherein the polypropylene polymer comprises a copolymer of propylene and butene having a butene content of about 5% to about 20% by weight.

7. 10. The polymeric material of claim 1, wherein the polypropylene polymer comprises a propylene, ethylene, and butene terpolymer.

8. 10. The polymeric material of claim 1, wherein the polypropylene polymer has a xylene content of about 5% to about 40% by weight.

9. 10. The polymeric material of claim 1, wherein the polypropylene polymer has a crystallinity of less than about 50%.

10. 2. The polymeric material of claim 1, wherein the polypropylene polymer has a molecular weight distribution (Mw / Mn) of about 2.5 to about 10.

11. The polymeric material of claim 1 , wherein the polymeric composition further comprises a filler.

12. 12. The polymeric material of claim 11, wherein the filler comprises talc, calcium carbonate, glass fiber, or mixtures thereof.

13. The polymeric material of claim 11, wherein the filler is present in the polymeric composition in an amount of from about 0% to about 40% by weight.

14. 10. The polymeric material of claim 1, wherein the polypropylene polymer is Ziegler-Natta catalyzed using a non-phthalate catalyst.

15. 10. The polymeric material of claim 1, wherein the polypropylene polymer is present in the polymeric composition in an amount greater than about 70% by weight.

16. The polymeric material of claim 1 , wherein the polymeric composition further comprises a nucleating agent.

17. The polymeric material of claim 1 , wherein the polymeric composition further comprises a processing aid.

18. A printer cartridge for a three-dimensional extrusion printing system comprising the polymeric material of claim 1.

19. The printer cartridge of claim 18, wherein the feedstock comprises a filament, the filament being wound around a spool within the printer cartridge.

20. 20. A three dimensional printing system comprising a three dimensional printing device and a printer cartridge according to claim 18.

21. A three-dimensional article formed from the polymeric material of claim 1.

22. 22. The three-dimensional article of claim 21, wherein the article is formed layer-by-layer from the polymeric material.

Images