Propylene terpolymers and heat sealable films made therefrom - Patents.com

Abstract

Propylene terpolymers are constructed that are particularly suitable for use in heat-sealing applications. Propylene terpolymers can be used, for example, to form a heat-sealing layer on a multi-layer film. The heat-sealing layer can be used to bond two opposing layers of a film together to form packaging materials and other articles. Random ethylene distribution is increased, resulting in reduced polymer crystallinity, reduced melting temperature, and a propylene terpolymer with a lower heat-sealing temperature is formed.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 218,156, filed July 2, 2021, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Polyolefin polymers are used in many different applications and fields. Polyolefin polymers are, for example, thermoplastic polymers that can be easily processed. Polyolefin polymers can also be recycled and reused. Polyolefin polymers are formed from hydrocarbons such as propylene and alpha-olefins, which are obtained from petrochemicals and are abundantly available.

[0003] In one application, polyolefin polymers are formulated and designed for use in the production of heat seal films and packaging materials. Heat seal films for use in packaging typically contain multiple polymer layers. At least one surface layer, called the heat seal layer, is formulated to have a lower melting temperature in order to heat seal or thermally bond to adjacent layers when sealing the packaging material. In the past, polypropylene terpolymers have been used to construct heat seal layers. Polypropylene terpolymers are typically produced from a combination of monomers including propylene, ethylene, and 1-butene or another higher alpha-olefin monomer. The incorporation of ethylene monomer can reduce the melting temperature of the resulting polymer. The incorporation of a third monomer, such as 1-butene, can improve the overall properties of the polymer and the heat seal layer made from the polymer. For example, butene can reduce the heat seal initiation temperature with its higher melting temperature.

[0004] For example, polypropylene terpolymers exhibit desirable physical properties in packaging applications with respect to tensile strength, tear resistance, scratch resistance, and low haze. A variety of different heat sealable films are disclosed, for example, in U.S. Patent Nos. 4,256,784, 6,365,682, U.S. Patent Publication Nos. 2006 / 0029824, and 2004 / 0081842, all of which are incorporated herein by reference.

[0005] Although various heat sealable films have been produced in the past, there is still a need for further improvements.In particular, there is still a need for polymers formulated for heat seal applications that exhibit lower melting temperatures and reduced heat seal initiation temperatures without increasing comonomer content or degrading other properties of the polymer or the film layer made from the polymer.For example, reducing the heat seal initiation temperature can significantly reduce the sealing time in film packaging applications, which can lead to reduced cycle times and increased productivity.There is also a need for polymers formulated for heat seal applications that have lower ethylene content and can be produced without reactor fouling problems. Summary of the Invention

[0006] In general, the present disclosure relates to a propylene terpolymer that is highly suitable for use as a heat seal layer in packaging films. The propylene terpolymer of the present disclosure, in one embodiment, contains propylene as the main monomer, has an ethylene content of about 1% to about 5% by weight, and has a butene content of about 1% to less than 8% by weight. The propylene terpolymer has a melt flow rate of about 1 g / 10 min to about 30 g / 10 min, a melting temperature of less than 140° C., and has an ethylene chain length distribution defined as follows: nE<0.0353Et+1.08 where Et is the ethylene content by weight. Of particular advantage, the propylene terpolymers of the present disclosure can be formulated to be phthalate-free.

[0007] In one embodiment, the butene content of the propylene terpolymer is about 3% to about 6.9% by weight, for example, about 5% to about 6.9% by weight. In one embodiment, the ethylene content of the propylene terpolymer can be about 1.5% to about 3.5% by weight. The propylene terpolymer can be Ziegler-Natta catalyzed without the use of a phthalate internal electron donor. The propylene content of the propylene terpolymer is generally greater than about 87% by weight, for example greater than about 90% by weight, for example greater than about 92% by weight, for example greater than about 94% by weight, and generally less than about 98% by weight.

[0008] The propylene terpolymer of the present disclosure formulated above may have a heat seal initiation temperature of less than about 115°C, for example less than about 110°C. The propylene terpolymer, in one embodiment, may have a melting temperature of about 110°C to about 129°C. The melt flow rate may be about 2 g / 10 min to about 10 g / 10 min. In one embodiment, the ethylene sequence length distribution of the terpolymer may be about 1.0 to about 1.2. Optionally, the propylene terpolymer may be a visbroken propylene terpolymer.

[0009] The present disclosure also relates to a polymer composition containing the above-mentioned propylene terpolymer. The propylene terpolymer can be present in the polymer composition in an amount of more than about 70% by weight, for example, more than about 80% by weight, for example, more than about 90% by weight, for example, more than about 95% by weight. The polymer composition can also contain various other additives, including one or more antioxidants, one or more acid scavengers, one or more UV stabilizers, one or more heat stabilizers, slip agents, antiblocking agents, etc.

[0010] The present disclosure also relates to a polymeric film layer containing the above-described propylene terpolymer.The polymeric film layer can be formed from the polymer composition.

[0011] In yet another aspect, the present disclosure relates to a multilayer film structure. The multilayer film structure comprises a base layer comprising a thermoplastic polymer and a heat seal layer comprising a propylene terpolymer. The propylene terpolymer can have the characteristics described above. In one aspect, the multilayer film structure can comprise a packaging film. The film structure can be formed by coextrusion. If desired, the film structure can also be unidirectionally or biaxially oriented.

[0012] Other features and aspects of the disclosure are discussed in more detail below. [Brief description of the drawings]

[0013] 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:

[0014] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of a multilayer film made in accordance with the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view of another embodiment of a multilayer film made in accordance with the present disclosure. [Diagram 3] FIG. 1 is a perspective view of a heat seal packaging material that may be made in accordance with the present disclosure. [Figure 4] 1 is a graphical representation of some of the results presented in the examples below.

[0015] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

[0016] Definitions and Test Procedures As used herein, the term "propylene terpolymer" is a terpolymer that contains a majority weight percent of propylene monomer in combination with at least two comonomers, such as ethylene and another α-olefin monomer, such as 1-butene. Propylene terpolymers may have individual repeat units of other comonomers present randomly or in statistical distribution in the polymer chain.

[0017] 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.

[0018] 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 60 minute precipitation time, also referred to herein as the "wet method". XS can also be measured according to the Viscotek 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 equipped with light scattering viscometer and refractometer detectors operating at 45°C. Instrument calibration is maintained with Viscotek PolyCAL™ polystyrene standards. To ensure that Viscotek instruments and sample preparation procedures provide consistent results by using L5D98 as a control to check method performance, a polypropylene (PP) homopolymer, such as biaxially oriented polypropylene (BOPP) grade L5D98 available from a variety of commercial sources, is used as the reference material. The value of L5D98 is first derived from testing using the ASTM method described above.

[0019] The ASTM D5492-06 method mentioned above can be adapted to determine the xylene soluble fraction. In general, the procedure consists of weighing out 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 condenser, the contents are stirred, and nitrogen (N 2 ) 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 60 minutes to allow crystallization of the xylene insoluble fraction. Once the solution has cooled and the insoluble fraction has precipitated from the solution, separation of the xylene soluble portion (XS) from the xylene insoluble portion (XI) is achieved by filtration through 25 micrometer filter paper. 100 mL of the filtrate is collected in a pre-weighed aluminum pan and 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%) = [(m 3 -m 2 ) * 2 / m 1 ] * 100, where m 1 is the original weight of the sample used, and m 2 is the weight of the empty aluminum pan, m 3 is the weight of the pan and residue (asterisks here and elsewhere in this disclosure) * indicates that the identified term or value is to be multiplied.

[0020] The sequence distribution of monomers in a polymer is 13 C-NMR, which also allows the location of the butene residues in relation to the adjacent propylene residues. 13C NMR can be used to measure ethylene content, butene content, triad distribution, and triad tacticity and is performed as follows. Samples were prepared by adding approximately 2.7 g of a 50 / 50 mixture of tetrachloroethane-d2 / orthodichlorobenzene containing 0.025 M Cr(AcAc)3 to 0.20 g of sample in a Norell 1001-7 10 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 was collected using a Bruker 400 MHz spectrometer equipped with a Bruker Dual DUL high temperature CryoProbe. Data is 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 percent butenes are calculated according to methods commonly used in the art, which are briefly summarized as follows:

[0021] The chain length distribution is defined by the following formula: nE<0.0353Et+1.08 where Et is the ethylene content by weight and the chain length is defined by the following formula:

[0022]

number

[0023] The chain length is 13 Measured by C NMR spectroscopy. Peak assignments, comonomer content, and monomer sequence length (nE) are calculated according to the method described in Zhang et al. Polymer Journal, Vol 35, No. 7, pp 551-559 (2003).

[0024] For convenience, butene content is also measured using Fourier transform infrared (FTIR), which is described above as a 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.

[0025] Mw / Mn (also called "MWD") and Mz / Mw are measured by gel permeation chromatography (GPC) according to the method for analysis of polypropylene. 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 is 1.0 mL / min and the injection volume is 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. Terpolymers made according to the present disclosure may have an MWD greater than about 3, such as greater than about 4, such as greater than about 4.8, and less than about 8, such as less than about 7.

[0026] 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. Polypropylene equivalent molecular weight is calculated by using the following formula using the Mark-Hwink coefficients reported for polypropylene and polystyrene (polypropylene: Scholte et. al. J. Appl. Polym. Sci., 29, 3763-3782 (1984)) and (polystyrene: Otocka et. al. Macromolecules, 4, 507 (1971)):

[0027]

number

[0028] [Table 1]

[0029] Melting point or melting temperature and crystallization temperature 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.

[0030] 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 observed 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:

[0031]

number

[0032] Alternatively, crystallinity can also be determined using the Heat of Crystallization (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.

[0033] The term "heat seal initiation temperature" (HSIT) is defined as the sealing temperature at which the heat seal strength first begins to increase from zero heat seal strength in the heat seal curve with the sealed film. HSIT measurements can be performed at Brückner film testing commercial laboratory using BMS TT03 method. The film is sealed using a Brügger HSG-CC heat sealer at the selected temperature, under 1 bar pressure, and with a dwell time of 1 second. The sealed film is cut into 15 mm wide strips. The seal strength is tested in a Zwick tensile strength tester by gripping the film in the clamps of the tensile tester and pulling it apart at an angle between the grips of 180°. The heat seal initiation temperature (HSIT) is determined as the seal temperature at which a seal strength of 1.0 N / 15 mm is achieved.

[0034] The haze of the film was measured according to ASTM D1003 method. Homopolymer polypropylene was used as the core layer (B) and terpolymer was used as the skin layer (A). The film structure is an ABA trilayer structure. The total film thickness is about 20 μm, and the ratio of the core layer and the skin layer is 90:10. The film made according to the present disclosure may show a haze of less than about 1%, for example less than about 0.8%, for example less than about 0.6% and more than about 0.1%. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Various embodiments are described below. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. An aspect described in conjunction with a specific embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiment.

[0036] When used herein in relation to numerical ranges, the terms "approximately," "about," "substantially," and similar terms 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 a use of a term that is not clear to those of ordinary skill in the art, given the context in which it is used, the term will be plus or minus 10% of the disclosed value. When "approximately," "about," "substantially," and similar terms are applied to structural features (e.g., to describe its shape, size, orientation, direction, etc.), these terms are meant to encompass minor variations in the structure that may result, for example, from the manufacturing or assembly process, and are intended to have a broad meaning consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Thus, these terms should be interpreted as indicating that insubstantial or insignificant modifications or variations of the subject matter described and claimed are considered to be within the scope of the present disclosure as set forth in the appended claims.

[0037] "A" and "an" and "the" and similar referents in the context of describing elements (particularly in the context of the claims below) should be construed to cover both the singular and the plural, unless otherwise indicated herein or the content clearly contradicts. 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 clearly contradicts otherwise. 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.

[0038] In general, the present disclosure relates to propylene terpolymers that exhibit lower melting temperatures while still retaining excellent mechanical and physical properties. Propylene terpolymers are particularly well suited for forming heat seal layers on a variety of different articles, such as packaging films. For example, propylene terpolymers can exhibit reduced heat seal initiation temperatures. In this regard, when used to produce packaging materials, heat seal layers made from propylene terpolymers allow for shorter sealing times, shorter cycle times, and increased production rates compared to previously made heat seal layers. In one aspect, propylene terpolymers are formed without the need to substantially increase comonomer levels compared to previously made similar terpolymers. Furthermore, propylene terpolymers can be formed with relatively low ethylene content.

[0039] Multilayer films including at least one external heat seal layer are used to form all different kinds of packaging materials. The packaging materials can be flexible or rigid. The packaging materials can be used to hold and store an endless variety of items, including, for example, snack foods, candy, hardware, all other types of food products, consumer products, etc. The heat seal layer is used to seal two opposing film layers together using heat and pressure before or after the packaging material is filled with its contents.

[0040] Heat seal layers used to seal packaging materials and other containers ideally have a relatively low melting temperature and / or heat seal initiation temperature. For example, during the heat sealing process, the temperature required to initiate sealing of the packaging material through the use of a heat seal layer should be lower than the softening point of the primary film layer so that the packaging material does not deteriorate, wrinkle, or shrink during the sealing process.

[0041] With reference to Figures 1 and 2, various embodiments of multilayer films made according to the present disclosure are shown for illustrative purposes only. As shown in Figure 1, the multilayer film 10 includes a primary film layer 15 adjacent to a heat seal layer 20 made according to the present disclosure in this embodiment. Specifically, the heat seal layer 20 is made from a propylene terpolymer. The heat seal layer 20 forms the outer surface of the multilayer film 10 and can be used to thermally bond the film to an adjacent film layer. In one embodiment, a packaging material can be formed by folding the multilayer film 10 so that the heat seal layer 20 faces the opposing heat seal layer. The two heat seal layers can then be thermally bonded together to form the packaging material.

[0042] In the embodiment shown in FIG. 1, the primary film layer 15 is shown as a single layer. However, it should be understood that the primary film layer 15 may be made of multiple layers of different thermoplastic polymers. Thermoplastic polymers that can be used to produce one or more primary film layers 15 include polyolefins, such as polypropylene, polyethylene, polybutylene, polystyrene, polyvinyl chloride, ethylene-containing copolymers, propylene-containing copolymers, and blends thereof. A metallized layer may be present in the primary film layer, which may form an outer layer if desired. Other suitable thermoplastic polymers that can be used to produce the film layers include various polyesters, such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate glycol, polyethylene naphthalate, polyamides, and the like.

[0043] Referring to Figure 2, another embodiment of a multilayer film 10 is shown. Like reference numbers are used to indicate similar elements. In the embodiment of Figure 2, the multilayer film 10 includes a primary film layer 15, a first heat seal layer 20, and a second heat seal layer 30. As shown, the heat seal layers 20 and 30 form the outer surface of the film 10. The heat seal layers 20 and 30 may be formed from a propylene terpolymer of the present disclosure.

[0044] 1 and 2, the heat seal layers 20 and 30 are relatively thin relative to the overall thickness of the film 10. For example, the heat seal layers 20 and 30 may have a thickness of less than about 20 micrometers, such as less than about 10 micrometers, such as less than about 5 micrometers, such as less than about 4 micrometers, such as less than about 3 micrometers, such as less than about 2 micrometers, and typically greater than about 0.1 micrometers, such as greater than about 0.5 micrometers, such as greater than about 1 micrometer. On the other hand, the multilayer film 10 may have a thickness of up to about 250 micrometers, such as less than about 225 micrometers, for example less than about 200 micrometers, such as less than about 175 micrometers, for example less than about 150 micrometers, such as less than about 125 micrometers, for example less than about 100 micrometers, such as less than about 75 micrometers, for example less than about 50 micrometers, and generally more than about 10 micrometers, such as more than about 20 micrometers, for example more than about 25 micrometers, such as more than about 35 micrometers, for example more than about 45 micrometers, such as more than about 55 micrometers, for example more than about 65 micrometers, such as more than about 75 micrometers, for example more than about 100 micrometers.

[0045] By way of example, referring to FIG. 3, a packaging material 50 is shown that may be formed in accordance with the present disclosure. The packaging material 50 may be made from the multilayer film 10 shown in either FIG. 1 or FIG. 2. The packaging material 50 includes a bottom 52, a side 54, and a top 56. The packaging material 50 is formed from two opposing flexible films in this embodiment. Each side of the packaging material may be made from an individual piece of film or may be formed by folding the film into an overlapping relationship. The heat seal layers 20 and 30 of the present disclosure may be used to seal the edges of the packaging material. For example, as shown in FIG. 3, the packaging material includes a sealed edge 60 that is formed by applying heat and pressure to the heat seal layers.

[0046] As shown, the packaging material 50 contains an item 70, such as a food product. Packaging materials made in accordance with the present disclosure can be used to contain and seal a variety of different products, such as snack foods, hardware, consumer products, etc. Additionally, the packaging material 50 can be used to contain flowable materials, such as liquids, including water, fruit juice, etc. The packaging material 50 can also be used to contain flowable gels, such as shampoos, conditioners, other hair products, toothpaste, etc.

[0047] When filling the packaging material as shown in FIG. 3, typically two layers of film are brought together and the edges are sealed to create a hollow interior with volume. Then, the product(s) are loaded into the hollow interior and the remaining sides of the packaging material are heat sealed. To heat seal the packaging material, the open end of the packaging material typically engages with a sealing device that applies a sufficient amount of heat and pressure to activate the heat seal layer to form a thermal bond. The faster the packaging material is sent through the filling and sealing process, the more economical the packaging process becomes. In this regard, the present disclosure generally relates to producing a heat seal layer from a propylene terpolymer having a lower melting temperature and a reduced heat seal initiation temperature. It has been found that the propylene terpolymers of the present disclosure can dramatically reduce the sealing time and / or sealing temperature, thereby substantially increasing productivity.

[0048] According to the present disclosure, by constructing a polymer with a more random and / or more uniformly distributed ethylene content, propylene terpolymers with lower melting temperatures and / or reduced heat seal initiation temperatures are produced. It is believed that a more random ethylene distribution reduces the crystallinity of the polymer, which in turn reduces the melting temperature and lowers the heat seal temperature.

[0049] Propylene terpolymers can be made using Ziegler-Natta catalysts. Ziegler-Natta catalysts can include a base catalyst component in combination with an internal electron donor. The internal electron donor can be, for example, a substituted phenyl diester. During polymerization, the base catalyst component as described above is combined with a cocatalyst and one or more external electron donors. The external electron donor can be, for example, one or more activity limiting agents. Through the use of Ziegler-Natta catalysts as described above, propylene terpolymers can be constructed by controlling the process conditions and the monomer and comonomer addition rates. Although not known, it is believed that catalyst systems such as those described above can contribute to a more random ethylene content and produce polymers that cannot be produced using other catalyst systems, such as catalyst systems using phthalate-based components, diether-based components, and succinate-based components. Indeed, one advantage of the polymers made according to the present disclosure is that the polymers can be phthalate-free.

[0050] The propylene terpolymers of the present disclosure may include a majority weight percent of propylene monomer in combination with at least two other monomers. The comonomers may be two or more α-olefins. The comonomers may be, for example, ethylene and butene (1-butene).

[0051] The propylene content of the propylene terpolymer is, for example, generally more than about 87% by weight, for example more than about 89% by weight, for example more than about 91% by weight, for example more than about 93% by weight, for example more than about 95% by weight. The total propylene content of the propylene terpolymer is generally less than about 98% by weight, for example less than about 96% by weight, for example less than about 94% by weight, for example less than about 92% by weight. The total comonomer content of the propylene terpolymer can be about 2% to about 15% by weight. For example, the total comonomer content of the propylene terpolymer can be less than about 13% by weight, for example less than about 11% by weight, for example less than about 9% by weight, and generally more than about 3% by weight, for example more than about 5% by weight.

[0052] As mentioned above, in one embodiment, the propylene terpolymer is an ethylene / butene / propylene terpolymer.The ethylene content of the terpolymer can generally be greater than about 1 wt%, for example greater than about 1.5 wt%, for example greater than about 2 wt%, for example greater than about 2.5 wt%, for example greater than about 3 wt%.The ethylene content of the terpolymer is generally less than about 5 wt%, for example less than about 4.5 wt%, for example less than about 4 wt%, for example less than about 3.5 wt%, for example less than about 3.3 wt%, for example less than about 3 wt%.

[0053] One advantage of the propylene terpolymers of the present disclosure is the ability to produce polymers with relatively low ethylene monomer content. By maintaining a lower ethylene monomer content, polymers can be produced with less particle agglomeration and easier to handle resins.

[0054] The butene content of the propylene terpolymer may generally be about 1% to about 15% by weight, and in one embodiment may be less than 8% by weight. For example, the butene content may be less than about 7.5% by weight, such as less than about 7.3% by weight, such as less than about 6.9% by weight. The butene content is generally greater than about 2% by weight, such as greater than about 3% by weight, such as greater than about 5% by weight.

[0055] The propylene terpolymer of the present disclosure generally has a xylene soluble (XS) content of about 2% to about 45% by weight. For example, the xylene soluble content may be less than about 40% by weight, such as less than about 30% by weight, such as less than about 20% by weight, and generally more than about 2% by weight, such as more than about 4% by weight, such as more than about 5% by weight. In one embodiment, the propylene terpolymer may have a relatively low xylene soluble content. For example, the propylene terpolymer may have a xylene soluble content of less than about 10% by weight, such as less than about 9% by weight, such as less than about 8% by weight.

[0056] The propylene terpolymer present in the composition may generally have a melt flow index (MFI) ranging from about 1 to about 30 g / 10 min, although polypropylenes having higher or lower melt flow indexes are also encompassed herein. For example, the propylene terpolymer may have a melt flow index of more than about 2 g / 10 min, such as more than about 3 g / 10 min, such as more than about 4 g / 10 min. The melt flow index of the propylene terpolymer may be less than about 18 g / 10 min, such as less than about 16 g / 10 min, such as less than about 14 g / 10 min, or less than about 10 g / 10 min.

[0057] The heat seal layer made according to the present disclosure can be formed from a polypropylene polymer composition containing a propylene terpolymer alone or in combination with various other components. The propylene terpolymer can be present in the propylene terpolymer 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 propylene terpolymer composition can contain almost only propylene terpolymer. For example, the propylene terpolymer can be present in an amount of more than about 96% by weight, such as more than about 97% by weight, such as more than about 98% by weight, such as more than about 99% by weight.

[0058] In one embodiment, the propylene terpolymers of the present disclosure are capable of peroxide cracking, which can increase the melt flow rate and reduce the molecular weight distribution.

[0059] Peroxide cracking is also referred to as the visbreaking process. During visbreaking, the higher molar mass chains of the propylene terpolymer 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.

[0060] Propylene terpolymers 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.

[0061] Visbreaking of the propylene terpolymer can be carried out during melt processing in the first extruder. For example, the propylene terpolymer 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 propylene terpolymer. In one embodiment, for example, the visbreaking agent can be first compounded with a polymer, such as a propylene terpolymer, to form a masterbatch. The masterbatch containing the visbreaking agent can then be blended with the propylene terpolymer and fed through the extruder. In yet another embodiment, the visbreaking agent can be physically blended with the propylene terpolymer, such as by being absorbed into 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.

[0062] The amount of visbreaking agent added to the propylene terpolymer may depend on various factors, including the desired cracking ratio. Generally, the visbreaking agent or peroxide may be added to the propylene 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 propylene terpolymer 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.

[0063] Generally, the propylene terpolymers can be subjected to visbreaking to have a cracking ratio of greater than about 1.1, such as greater than about 1.3, such as greater than about 1.5, such as greater than about 1.7, such as greater than about 2, and generally less than about 10, such as less than about 5, such as less than about 3, such as less than about 2.5. The cracking ratio is calculated by dividing the final melt flow rate of the polymer by the initial melt flow rate of the polymer.

[0064] As mentioned above, propylene terpolymers are constructed in accordance with the present disclosure to have a more random ethylene distribution. The ethylene distribution within the terpolymer can be related to the chain length defined by the following formula:

[0065]

number

[0066] Based on the chain lengths defined above, the propylene terpolymers made according to the present disclosure, in one embodiment, have a particular chain length distribution for ethylene defined by the following formula: nE<0.0353Et+1.08 where Et is the ethylene content by weight. In certain embodiments, the polypropylene terpolymer may have an ethylene chain length distribution of less than 1.26, such as less than 1.24, such as less than about 1.22, such as less than 1.2, such as less than about 1.18, such as less than about 1.15. The ethylene chain length distribution contained within the terpolymer is generally greater than 1, such as greater than about 1.05.

[0067] It is believed that the more random the ethylene distribution in the terpolymer, the lower the polymer crystallinity, which in turn lowers the melting temperature and lowers the heat seal temperature.The melting temperature of the propylene terpolymer can be, for example, less than about 140°C, for example less than about 135°C, for example less than about 132°C, for example less than about 130°C, for example less than about 129°C, for example less than about 127°C, for example less than about 125°C.The melting temperature is generally greater than 110°C, for example greater than about 115°C, for example greater than about 120°C.The heat seal initiation temperature of the propylene terpolymer is less than 110°C, for example less than about 109°C, for example less than about 108°C, and generally greater than about 80°C, for example greater than about 90°C, for example greater than 100°C.

[0068] The propylene terpolymers of the present disclosure can be formed in a variety of 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 specific application.

[0069] 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.

[0070] In one embodiment, the preparation of the catalyst component involves halogenation of mixed magnesium and titanium alkoxides.

[0071] 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.

[0072] 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 )fXg wherein R e is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms or COR′, or R′ is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms, and each OR e The 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.

[0073] 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 contain 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.

[0074] 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 C 1 ~C 4 alkyl, X is Br, Cl, or I, and g is 0, 1, 2, 3, or 4.

[0075] 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.

[0076] The aluminum alkoxides referred to above have the formula Al(OR') 3 where each R' is individually a hydrocarbon having up to 20 carbon atoms. This can 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.

[0077] 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.

[0078] Examples of epoxy compounds include, but are not limited to, glycidyl-containing compounds of the following formula:

[0079] [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.

[0080] In yet another embodiment, substantially spherical MgCl 2 The -nEtOH adduct may be formed by a spray crystallization process, in which MgCl 2 The -nROH melt (n is 1-6) is sprayed into a vessel while introducing an inert gas into the top of the vessel at a temperature of 20-80°C. 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 MgCl 2 The particles are then classified into the desired size. Particles of undesired sizes can be recycled. In a preferred embodiment for catalyst synthesis, spherical MgCl 2 The precursor has an average particle size (Malvern d) of between about 15 and 150 micrometers, preferably between 20 and 100 micrometers, and most preferably between 35 and 85 micrometers. 50 ).

[0081] 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.

[0082] 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 TiCl 4 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 in a mixture of a halogenating agent and a chlorinated aromatic liquid, with 40 to 60 volume percent of the halogenating agent, such as TiCl. 4 This is done by using a mixture comprising:

[0083] 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.

[0084] 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.

[0085] 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:

[0086] [ka] (In the formula, R 1 , R 2 , R 3 , and R 4 are hydrocarbyl groups each having 1 to 20 carbon atoms, the hydrocarbyl groups including cycloalkyl groups having a branched or linear structure or having 7 to 15 carbon atoms; E 1 and E 2are the same or different and are selected from the group consisting of alkyl having 1 to 20 carbon atoms, substituted alkyl having 1 to 20 carbon atoms, aryl having 1 to 20 carbon atoms, substituted aryl having 1 to 20 carbon atoms, or an inert functional group having 1 to 20 carbon atoms and optionally containing a heteroatom; X 1 and X 2 are each O, S, an alkyl group, or NR 5 (In the formula, R 5 is a hydrocarbyl group having 1 to 20 carbon atoms or hydrogen).

[0087] 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.

[0088] 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.

[0089] In one embodiment, the substituted phenylenediester has the following structure (I):

[0090] [ka]

[0091] In one embodiment, structure (I) comprises an R 1 and R 3 Includes: R 2 , R 4 , and R 5 ~R 14 Each of is hydrogen.

[0092] In one embodiment, structure (I) is R 1 and R 4 as a methyl group, R 3 R is a cycloalkyl group such as a cyclohexyl group. 2 and R 5 ~R 14 Each of is hydrogen.

[0093] In one embodiment, structure (I) is R 1 , R 5 , and R 10 as a methyl group, R 3 is a t-butyl group. 2 , R 4 , R 6 ~R 9 , and R 11 ~R 14 Each of is hydrogen.

[0094] In one embodiment, structure (I) is R 1 , R 7 , and R 12 Each of these is a methyl group, and R 3 is a t-butyl group. 2 , R 4 , R 5 , R 6 , R 8 , R 9, R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0095] In one embodiment, structure (I) is R 1 as a methyl group, R 3 is a t-butyl group. 7 and R 12 Each of R is an ethyl group. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0096] In one embodiment, structure (I) is R 1 , R 5 , R 7 , R 9 , R 10 , R 12 , and R 14 as a methyl group, R 3 is a t-butyl group. 2 , R 4 , R 6 , R 8 , R 11 , and R 13 Each of is hydrogen.

[0097] In one embodiment, structure (I) is R 1 as a methyl group, R 3 is a t-butyl group. 5 , R 7 , R 9 , R 10 , R 12 , and R 14 Each of R is an i-propyl group. 2 , R 4 , R 6 , R 8 , R 11 , and R 13Each of is hydrogen.

[0098] In one embodiment, the substituted phenylene aromatic diester is a R 1 ~R 14 The compound has a structure selected from the group consisting of structures (II)-(V), including alternatives of each of the following:

[0099] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is an ethoxy group. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0100] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is a fluorine atom. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0101] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is a chlorine atom. 2 , R 4 , R5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0102] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is a bromine atom. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0103] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is an iodine atom. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0104] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 6 , R 7 , R 11 , and R 12 Each of R is a chlorine atom. 2 , R 4 , R 5 , R 6 , R8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0105] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 6 , R 7 , R 11 , and R 12 Each of R is a chlorine atom. 2 , R 4 , R 5 , R 7 , R 9 , R 10 , R 12 , and R 14 Each of is hydrogen.

[0106] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 2 , R 4 , and R 5 ~R 14 Each of is a fluorine atom.

[0107] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is a trifluoromethyl group. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0108] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R3 is a t-butyl group. 7 and R 12 Each of R is an ethoxycarbonyl group. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0109] In one embodiment, R 1 is a methyl group, and R 3 is a t-butyl group. 7 and R 12 Each of R is an ethoxy group. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0110] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 is a t-butyl group. 7 and R 12 Each of R is a diethylamino group. 2 , R 4 , R 5 , R 6 , R 8 , R 9 , R 10 , R 11 , R 13 , and R 14 Each of is hydrogen.

[0111] In one embodiment, structure (I) comprises R which is a methyl group. 1 Including R 3 R is the 2,4,4-trimethylpentan-2-yl group. 2 , R4 , and R 5 ~R 14 Each of is hydrogen.

[0112] In one embodiment, structure (I) is R 1 and R 3 each of which is a sec-butyl group. 2 , R 4 , and R 5 ~R 14 Each of is hydrogen.

[0113] In one embodiment, structure (I) comprises R 1 and R 4 Includes: R 2 , R 3 , R 5 ~R 9 , and R 10 ~R 14 Each of is hydrogen.

[0114] In one embodiment, structure (I) comprises R which is a methyl group. 1 Includes: R 4 is an i-propyl group. 2 , R 3 , R 5 ~R 9 , and R 10 ~R 14 Each of is hydrogen.

[0115] In one embodiment, structure (I) is R 1 , R 3 , and R 4 each of which is an i-propyl group. 2 , R 5 ~R 9 , and R 10 ~R 14 Each of is hydrogen.

[0116] 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 represented by the formula R 3 Al, where each R is an alkyl, cycloalkyl, aryl, or hydride radical, at least one R is a hydrocarbyl radical, 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 from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms. In further embodiments, each alkyl radical can be straight or branched chain, 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, and n-dodecyl.

[0117] 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.

[0118] 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.

[0119] For example, a suitable catalyst composition 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 a mixture of components, that is 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 as the polymerization temperature increases above a threshold temperature (e.g., a temperature above about 95°C) in the presence of the catalyst. 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 a single compound can be classified, for example, as both an activity limiting agent and a selectivity control agent.

[0120] 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.

[0121] In one embodiment, the alkoxysilane has the general formula: SiR 20 m (OR 21 ) 4-m (I) (wherein, R 20 is independently, at each occurrence, 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; 20 contains up to 20 atoms excluding hydrogen and halogens, R 21 is C 1~4 m is an alkyl group, and m is 0, 1, 2, or 3. 20 is C 6~12 Aryl, alkyl, or aralkyl, C 3~12 Cycloalkyl, C 3~12 Branched alkyl, or C3~12 is a cyclic or acyclic amino group, R 21 is C 1~4 alkyl and m is 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.

[0122] 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.

[0123] The activity limiting agent may be a carboxylic acid ester. The aliphatic carboxylic acid ester may be C 4 ~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 may be any combination thereof. 4 ~C 30 The aliphatic acid esters may also be substituted with one or more Group 14, 15, or 16 heteroatom-containing substituents. 4 ~C 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 1~4Allyl mono- and diesters, aliphatic C 8~20 Monocarboxylic and dicarboxylic acids C 1~4 Alkyl esters, and C 2~100 (Poly)glycol or C 2~100 (Poly)glycol ether C 4~20 In a further embodiment, C 4 ~C 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 glyceryl tri-esters of aliphatic carboxylic acids, and mixtures thereof. 4 ~C 30 The aliphatic ester is isopropyl myristate or di-n-butyl sebacate.

[0124] The catalyst system of the present disclosure as described above can be used to produce olefin-based polymers. The process involves contacting an olefin with the catalyst system under polymerization conditions.

[0125] In one embodiment, the polymerization occurs by gas phase polymerization. As used herein, "gas phase polymerization" is the passage of an ascending fluidizing medium, a fluidizing medium containing one or more monomers, in the presence of a catalyst through a fluidized bed of polymer particles maintained in a fluidized state by the fluidizing medium. "Fluidization", "fluidized", or "fluidizing" is a gas-solid contacting process in which a bed of fine polymer particles is lifted and agitated by an upward flow of gas. Fluidization occurs in a bed of particulate matter when the upward flow of fluid through the interstices of the bed of particles acquires a pressure differential and an increase in frictional resistance that exceeds the weight of the particulate matter. Thus, a "fluidized bed" is a plurality of polymer particles suspended in a fluidized state by the flow of the fluidizing medium. A "fluidizing medium" is a mixture of one or more olefin gases, optionally a carrier gas (e.g., H 2 Or N 2 ), and optionally a liquid (e.g., a hydrocarbon) that rises through the gas phase reactor.

[0126] A typical gas phase polymerization reactor (or gas phase reactor) includes a vessel (i.e., reactor), a fluidized bed, a distribution plate, inlet and outlet piping, a compressor, a cycle gas cooler or heat exchanger, and a product discharge system. The vessel includes a reaction zone and a velocity reduction zone, each of which is located above the distribution plate. The bed is located in the reaction zone. In one embodiment, the fluidizing medium includes propylene gas and at least one other gas, such as an olefin, and / or a carrier gas, such as hydrogen or nitrogen.

[0127] In one embodiment, the contacting occurs by feeding the catalyst composition to a polymerization reactor and introducing the olefin into the polymerization reactor.

[0128] However, it should be understood that in addition to gas phase polymerization processes, the catalyst system of the present disclosure can also be used in all different types of bulk phase polymerization processes, including slurry systems with loop reactors.

[0129] The propylene terpolymers made according to the present disclosure can then be incorporated into various polymer compositions to produce articles such as film layers and / or heat seal layers. The polymer compositions may contain the propylene terpolymers in combination with various other components.

[0130] 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 Sovay). In another embodiment, the antioxidant can be N,N-dioctadecylhydroxylamine (e.g., FS042). Phosphites and phosphonites can 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.

[0131] The polymer composition may also contain an antacid to act 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.

[0132] 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.

[0133] The polymer composition may also contain slip agents and antiblocking agents. Slip agents include amides such as fatty acid amides. The term "antiblocking agent" is used herein to describe materials that reduce the tendency of films or sheets of polymeric film to stick or adhere to each other or to other surfaces when such adhesion is undesirable. Typical antiblocking agents include colloidal silica, micronized silica, clays, silicon, and certain amides and amines. These above agents are typically present in the film at a concentration of about 500 ppm to about 20,000 ppm in the outer layer.

[0134] In some embodiments, the polymer composition may optionally include stabilizers that may prevent or reduce degradation of the polymer blend due to 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.

[0135] In one aspect, the polymer composition may also contain one or more colorants. The colorants may be dyes or pigments. In one embodiment, a blend of colorants may be used to produce filaments having a particular color.

[0136] 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).

[0137] [ka] (In the formula, R 30 is oxygen, sulfur, or a hydrocarbon group of 1 to 10 carbon atoms; R 31 and R 32 each is hydrogen or a hydrocarbon or hydrocarbon group of 1 to 10 carbon atoms; R 31 and R 32 may be the same or different, R 31 Two of them, R 32 Two of these, or R 31 and R 32 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, provided that n>m.

[0138] 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], 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].

[0139] The 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.

[0140] 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.

[0141] Commercially available examples of nucleating agents include, but are not limited to, ADK NA-11, ADK NA-21, ADK NA-21E, ADK NA-21F, and ADK 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 XT386 manufactured by Ciba Specialty Chemicals.

[0142] When present in the polymer composition, the one or more nucleating agents are generally added in an amount greater than about 100 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.

[0143] After the polymer composition containing the propylene terpolymer has been formulated, in one embodiment, the composition may be formed into a film layer, such as a heat seal layer.

[0144] The film forming process may include one or more of the following procedures: extrusion, coextrusion, cast extrusion, blown film forming, double bubble film forming, tenter frame technology, calendaring, coating, dip coating, spray coating, lamination, biaxial orientation, injection molding, thermoforming, compression molding, and any combination thereof.

[0145] In one embodiment, the process includes forming a multilayer film. The term "multilayer film" is a film having two or more layers. The layers of the multilayer film are bonded together by one or more of the following non-limiting processes: coextrusion, extrusion coating, vapor deposition coating, solvent coating, emulsion coating, or suspension coating.

[0146] In one embodiment, the process includes forming an extruded film. The term "extrusion" and similar terms are a process for forming a continuous shape by forcing a molten plastic material through a die, optionally followed by cooling or chemical hardening. A relatively high viscosity polymeric material is fed to a rotating screw that passes through the die immediately prior to extrusion through the die. The extruder can be a single screw extruder, a multi-screw extruder, a disk extruder, or a ram extruder. The die can be a film die, a blown film die, a sheet die, a pipe die, a tubing die, or a profile die. Non-limiting examples of extruded articles include pipes, films, and / or fibers.

[0147] In one embodiment, the process includes forming a coextruded film. The term "coextrusion" and similar terms refer to a process for extruding two or more materials through a single die in which two or more orifices are disposed, so that the extrudates coalesce or otherwise weld together into a layered structure. At least one of the coextruded layers contains the propylene-based polymer. Coextrusion can be used as an aspect of other processes, for example, in film blowing, casting film, and extrusion coating processes.

[0148] In one embodiment, the process includes forming a blown film. The term "blown film" and like terms are films made by a process in which a polymer or copolymer is extruded to form bubbles filled with air or another gas in order to orient the polymer film. The bubbles are then collapsed and collected into a flat film.

[0149] After the multilayer film is formed, it can be used to form all different types of packaging materials according to the present disclosure. For example, Figure 3 is an exemplary embodiment of a packaging material that can be made according to the present disclosure.

[0150] The invention having thus been generally described will be more readily understood with reference to the following examples, which are provided by way of illustration and are not intended to limit the invention. EXAMPLES

[0151] Six different propylene terpolymers were formulated and tested for melting temperature and heat seal initiation temperature (HSIT). Each terpolymer contained propylene as the primary monomer combined with ethylene and butene. The ethylene chain length distribution was calculated for samples 1-3 and 6.

[0152] All of the propylene terpolymers were made using a Ziegler-Natta catalyst system. In samples nos. 1-4, the solid catalyst component contained a phenylene substituted diester as the internal electron donor. Sample no. 5 was a commercially available propylene terpolymer. Sample no. 6 was formed in the presence of LYNX1010, a phthalate-based catalyst commercially available from W.R. Grace. All of the following samples, except samples nos. 1, 2, and 6, were visbroken. The following results were obtained:

[0153] [Table 2]

[0154] A comparison of the chain length and ethylene content of each propylene terpolymer is shown in Figure 4. As shown in Figure 4, sample numbers 1 and 2 showed very random ethylene distribution. These samples also showed very low melting and heat seal initiation temperatures while containing butene amounts less than 8 wt%, especially less than 7 wt%.

[0155] While particular embodiments have been illustrated and described, it should be understood that changes and modifications may be made therein by those skilled in the art without departing from the technology in its broader aspects as defined in the following claims.

[0156] The embodiments illustratively described herein may suitably be 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 shown and described features 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 features of the claimed technology. The phrase "consisting of" excludes any elements not specified.

[0157] The present disclosure is not limited with respect to the specific embodiments described in this application. As will be apparent to those skilled in the art, many modifications and variations can be made without departing from the spirit and scope of the present invention. In addition to those recited herein, functionally equivalent methods and compositions within the scope of the present disclosure will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that the disclosure is not limited to particular methods, reagents, compounds, compositions, or biological systems, which may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0158] Additionally, when 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 also thereby described in terms of any individual members or subgroups of members of the Markush group.

[0159] As will be understood by those skilled in the art, for any 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. 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 skilled 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 can then be subdivided into the subranges discussed above. Finally, as will be understood by those skilled in the art, a range includes each individual member.

[0160] All publications, patent applications, issued patents, and other documents referenced herein are incorporated by reference 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.

[0161] Other embodiments are within the scope of the following claims.

Claims

Claim 1 A propylene terpolymer comprising: propylene as a main monomer; an ethylene content of about 1 wt% to about 5 wt%; a butene content of about 1 wt% to less than about 8 wt%; and having a melt flow rate of about 1 g / 10 min to about 30 g / 10 min, a melting temperature of less than 140 °C, and an ethylene chain length distribution defined as follows: nE < 0.0353Et + 1.08 wherein Et is the ethylene content by weight. Claim 2 The propylene terpolymer according to claim 1, wherein the butene content is about 3 wt% to about 7 wt%. Claim 3 The propylene terpolymer according to claim 1, having a heat seal start temperature of less than about 115 °C. Claim 4 The propylene terpolymer according to claim 1, having a melting temperature of about 110 °C to about 135 °C. Claim 5 The propylene terpolymer according to claim 1, wherein the xylene soluble content is about 2 wt% to about 10 wt%. Claim 6 The propylene terpolymer according to claim 1, having a melt flow rate of about 2 g / 10 min to about 20 g / 10 min. Claim 7 The propylene terpolymer according to claim 1, having an ethylene content of about 1.5 wt% to about 3.5 wt%. Claim 8 The propylene terpolymer according to claim 1, wherein the Ziegler-Natta catalytic reaction is carried out using a non-phthalate catalyst. Claim 9 The propylene terpolymer according to claim 1, having a propylene content of about 87 wt% to about 98 wt%. Claim 10 The propylene terpolymer according to claim 1, having an ethylene chain length distribution of about 1.00 to about 1.

20. Claim 11 The propylene terpolymer according to claim 1, which is bis-broken or in-reactor grade. Claim 12 A process for producing the propylene terpolymer according to claim 1, comprising polymerizing a propylene monomer, an ethylene monomer, and a butene monomer in the presence of a Ziegler-Natta catalyst, wherein the Ziegler-Natta catalyst comprises a catalyst component and an activity limiting agent, and the catalyst component comprises a magnesium moiety, a titanium moiety, and an internal electron donor. Claim 13 The process according to claim 12, wherein the monomer is polymerized in a slurry loop reactor in the presence of the catalyst component and the activity limiting agent. Claim 14 ​ The process according to claim 12, wherein the monomer is polymerized in a gas-phase reactor in the presence of the catalyst component and the activity limiter.

15. The process according to claim 12, wherein the internal electron donor comprises a substituted phenylene diester.

16. A polymer film layer comprising the propylene terpolymer according to claim 1, wherein the propylene terpolymer is present in the polymer film layer in an amount exceeding about 70% by weight.

17. A multilayer film structure comprising: a base layer comprising a thermoplastic polymer; a heat-sealing layer comprising a propylene terpolymer, wherein the propylene terpolymer comprises propylene as a main monomer, has an ethylene content of about 1% to about 5% by weight, a butene content of more than about 1% by weight, the propylene terpolymer has a melt flow rate of about 1 g / 10 min to about 20 g / 10 min, a heat-sealing start temperature of less than about 110°C, and an ethylene chain length distribution defined as follows: nE < 0.0353Et + 1.08 (wherein Et is the ethylene content by weight).

18. The multilayer film structure according to claim 17, comprising a packaging film.

19. The multilayer film structure according to claim 17, wherein the ethylene chain length distribution of the terpolymer is from about 1.00 to about 1.

20.

20. The multilayer film structure according to claim 17, wherein the film structure is coextruded, biaxially stretched, unidirectionally stretched, or cast film processed.

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