Enhanced melt strength low density polyethylene for films or blends

Abstract

The present invention relates to a low-density polyethylene having a melt strength greater than or equal to 5.5 cN measured at 190° C., a strength greater than or equal to 0.9210 g / cm 3 and less than or equal to 0.9275g / cm 3 and a melt index I2 greater than or equal to 4.5 g / 10 min measured at 190°C.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 005,798, filed April 6, 2020, the entire disclosure of which is hereby incorporated by reference. Technical Field

[0003] Embodiments of the present disclosure relate generally to low density polyethylene, and particularly to low density polyethylene having enhanced melt strength. Background Art

[0004] The properties of the resin used to make the film, such as melt strength, viscosity, molecular weight distribution, density, etc., can affect the performance of the film (such as cast film, blown film, or thermoformed film). Blending different types of ethylene-based polymers, such as low density polyethylene (LDPE) with linear low density polyethylene (LLDPE), can improve some of these properties, but such blending can lead to batch-to-batch inconsistencies.

[0005] Ethylene-based polymers are disclosed in the following references: WO 2017 / 14698, WO 2010 / 042390, WO 2010 / 144784, WO 2011 / 019563, WO 2012 / 082393, WO 2006 / 049783, WO 2009 / 114661, US 2008 / 0125553, US 7,741,415, US 8,916,667, US 9,303,107, and EP 2239283B1. However, such polymers do not provide improved melt strength and an optimized balance of film properties. Therefore, there remains a need for new ethylene-based polymers, such as LDPE, with an optimized balance of melt strength, processability, and density (stiffness). Summary of the Invention

[0006] In an embodiment, the low density polyethylene comprises: a melt strength greater than or equal to 5.5 centinetokels (cN) measured at 190 degrees Celsius (°C); a strength greater than or equal to 0.9210 grams per cubic centimeter (g / cm3); 3 ) and less than or equal to 0.9275g / cm 3 density; and a melt index I2 greater than or equal to 4.5 g / 10 min measured at 190 ° C.

[0007] In embodiments, the low density polyethylene comprises: a melt strength greater than 5.5 cN measured at 190°C; and a tensile strength greater than or equal to 0.9210 g / cm 3 and less than or equal to 0.9275g / cm 3 density.

[0008] Additional features and advantages will be set forth in the detailed description which follows, and in part will become apparent to those skilled in the art from the detailed description or may be learned by practicing the embodiments described herein, including the following detailed description, claims, and accompanying drawings.

[0009] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 schematically depicts a process system according to embodiments disclosed and described herein;

[0011] Figure 2 Diagrammatically depicting the CDF of low density polyethylene according to embodiments disclosed and described herein IR Chromatogram;

[0012] Figure 3 Diagrammatically depicting the CDF of low density polyethylene according to embodiments disclosed and described herein DV Chromatogram;

[0013] Figure 4 Diagrammatically depicting the CDF of low density polyethylene according to embodiments disclosed and described herein LS Chromatogram;

[0014] Figure 5 graphically depicts an LSP chromatogram of a low density polyethylene according to embodiments disclosed and described herein; and

[0015] Figure 6 Graphically depicted is a melt strength overlay at 190°C for low density polyethylene according to embodiments disclosed and described herein. DETAILED DESCRIPTION

[0016] The specific embodiments of the present application will now be described. However, the present disclosure can be implemented in different forms and should not be construed as being limited to the embodiments set forth in the present disclosure. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art.

[0017] According to an embodiment, the low density polyethylene comprises: a melt strength greater than or equal to 5.5 cN measured at 190°C; a strength greater than or equal to 0.9210 g / cm 3 and less than or equal to 0.9275g / cm 3 and a melt index I2 greater than or equal to 4.5 g / 10 min measured at 190°C. According to an embodiment, the low density polyethylene comprises: a melt strength greater than 5.5 cN measured at 190°C and greater than or equal to 0.9210 g / cm 3 and less than or equal to 0.9275g / cm 3 density.

[0018] definition

[0019] As used herein, the term "composition" encompasses a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0020] As used herein, the term "blend" or "polymer blend" refers to a mixture of two or more polymers. A blend may be miscible or immiscible (not phase separated at the molecular level). An admixture may or may not be phase separated. A blend may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, x-ray scattering, and other methods known in the art. A blend can be achieved by physically mixing the two or more polymers at the macroscopic level (e.g., melt blending resins or compounding) or at the microscopic level (e.g., simultaneously formed in the same reactor).

[0021] The terms "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional components, steps, or procedures, whether or not specifically disclosed. For the avoidance of any doubt, all compositions claimed through use of the term "comprising" may include any additional additives, adjuvants, or compounds, whether polymeric or otherwise, unless stated to the contrary. Conversely, the term "consisting essentially of excludes from the scope of any subsequently recited content any other component, step, or procedure (except those that are not essential to operability). The term "consisting of excludes any ingredient, step, or procedure not specifically recited or listed.

[0022] As used herein, the term "low density polyethylene," abbreviated as "LDPE," may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene." LDPE is known in the art and refers herein to an ethylene homopolymer prepared using high pressure (≥100 MPa (e.g., 100 MPa-400 MPa)) free radical polymerization. LDPE resins typically have a density of 0.915 g / cm 3 to 0.935g / cm 3 As referred to herein, unless expressly stated otherwise, the terms "low density polyethylene," "LDPE," and the like refer to the polyethylene polymer itself and do not include any additives that may be blended with the low density polyethylene. Therefore, unless expressly stated otherwise, the properties of the low density polyethylene referred to in this disclosure refer to the properties of the low density polyethylene polymer itself without any additives.

[0023] As used herein, the term "linear low density polyethylene," abbreviated as "LLDPE," includes resins made using Ziegler-Natta catalyst systems, as well as resins made using single-site catalysts including, but not limited to, dimetallocene catalysts (sometimes referred to as "m-LLDPE"), phosphinimines, and constrained geometry catalysts, and resins made using post-metallocene, molecular catalysts including, but not limited to, bis(biphenylphenoxy) catalysts (also known as polyvalent aryloxyether catalysts). LLDPE includes linear, substantially linear, or heterogeneous ethylene-based copolymers or homopolymers. LLDPE includes: substantially linear ethylene polymers, which are further defined in the following U.S. Patents: U.S. Patent No. 5,272,236, U.S. Patent No. 5,278,272, U.S. Patent No. 5,582,923 and U.S. Patent No. 5,733,155; homogeneously branched ethylene polymers, such as those in U.S. Patent No. 3,645,992; heterogeneously branched ethylene polymers, such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698; and blends thereof (such as those disclosed in U.S. Patent No. 3,914,342 or U.S. Patent No. 5,854,045). LLDPE resins can be prepared using any type of reactor or reactor configuration known in the art, via gas phase, solution phase or slurry polymerization, or any combination thereof.

[0024] Process of implementing the solution

[0025] In order to prepare low density polyethylene, the autoclave tubular reactor combination polymerization process of high pressure free radical initiation is used. Two different free radical initiated high pressure polymerization process types are known. In the first type, a stirred autoclave container with one or more reaction zones is used. The autoclave reactor usually has several injection points for initiator or monomer feed or both. In the second type, a jacketed tube is used as a tubular reactor with one or more reaction zones. Suitable but non-restrictive reactor lengths can be 100 meters (m) to 3000m or 1000m to 2000m. The beginning of the reaction zone of the reactor is usually limited by the lateral injection of the initiator, ethylene, chain transfer agent (or telomer), comonomer and any combination thereof of the reaction. High pressure process can also be carried out in an autoclave or tubular reactor with one or more reaction zones or in a combination of an autoclave and a tubular reactor that each includes one or more reaction zones.

[0026] Chain transfer agents can be used to control molecular weight. In a preferred embodiment, one or more chain transfer agents (CTA) can be added to the polymerization process. Typical CTAs include, but are not limited to, propylene, isobutane, n-butane, 1-butene, methyl ethyl ketone, acetone, and propionaldehyde. In one embodiment, the amount of CTA used in the process is from 0.03% to 10% by weight of the total reaction mixture.

[0027] The ethene that is used to prepare Low Density Polyethylene can be purified ethene, and it obtains by removing polar components from recycle loop stream.It is not typical that requires to prepare Low Density Polyethylene with purified ethene.In such case, ethene from recycle loop can be used.

[0028] Reference will now be made in detail to embodiments of systems and processes for producing low density polyethylene according to embodiments disclosed and described herein.

[0029] Now refer to Figure 1 , which is a block diagram of a process reaction system for preparing low-density polyethylene according to an embodiment, Figure 1 The process reaction system 100 shown is a partially closed-loop dual-circulation high-pressure low-density polyethylene system. Figure 1In the embodiment shown, the process reaction system 100 may include a booster / main compressor 110, a super compressor 120, an adiabatic autoclave reactor 130 coupled to a tubular reactor 140, a high-pressure separator 150, and a low-pressure separator 160. According to the embodiment, the autoclave reactor 130 may include three zones 130A, 130B, and 130C. A first peroxide initiator stream 124 may be injected into each zone 130A of the autoclave reactor 130, and a third peroxide initiator stream 125 may be injected into zone 3 130C of the autoclave reactor 130. The second peroxide initiator stream 123 may be mixed with the side stream 122 or injected into zone 2 of the reactor 130B. Similarly, the peroxide initiator stream 132 may be injected into the inlet of the tubular reactor 140. The tubular reactor 140 may use a cooling jacket (not shown) installed around the outer shell of the tubular reactor 140. The cooling jacket of the tubular reactor 140 may use high-pressure water to cool or adjust the temperature in the tubular reactor 140 .

[0030] Fresh ethylene feed stream 101 can be mixed with chain transfer agent (CTA) stream 102 and ethylene-rich stream 162 to form a first mixed stream (i.e., a mixed stream of fresh ethylene, high-pressure recycled ethylene, and CTA). This first mixed stream can be introduced into booster / primary compressor 110, which is in turn connected to super compressor 120 located downstream of booster / primary compressor 110. In booster / primary compressor 110, the mixed stream is compressed and leaves booster / primary compressor 110 in the form of compressed stream 111. Compressed stream 111 can be mixed with high-pressure recycle stream 154 (which is a portion of ethylene-rich stream 152 from high-pressure separator 150) to form a second mixed stream (i.e., a mixed stream of high-pressure recycled ethylene with super-compressed fresh ethylene, high-pressure recycled ethylene, and CTA). The second mixed stream may be introduced into a hypercompressor 120, which is in turn connected to a booster / first-stage compressor 110 located upstream of the hypercompressor 120, and in turn connected to an autoclave reactor 130 located downstream of the hypercompressor 120. At the hypercompressor 120, the second mixed stream is further compressed into a super-compressed stream 121 that exits the hypercompressor 120.

[0031] The super-compressed stream 121 is introduced into an autoclave reactor 130, which is in turn connected to a super compressor 120 located upstream of the autoclave reactor 130 and to a tubular reactor 140 located downstream of the autoclave reactor 130. A side stream 122 is separated from the super-compressed stream 121, such as by a splitter (not shown), and introduced into the autoclave reactor 130 as side stream 122. The side stream 122 and the portion of the super-compressed stream 121 entering the autoclave reactor 130 can be equal in proportion. This portion of the super-compressed stream 121 can be fed to the top of the autoclave reactor 130, such as zone 1 130A of the autoclave reactor 130. The side stream 122 can be fed to the side of the autoclave reactor 130, such as zone 2 130B. In the autoclave reactor 130, the super-compressed stream 121 and the side stream 122 may be partially polymerized and exit the autoclave reactor 130 as stream 131. Stream 131 may then be fed to a tubular reactor 140, which is in turn connected to the autoclave reactor 130 upstream of the tubular reactor 140 and in turn connected to a high-pressure separator 150 downstream of the tubular reactor 140. In the tubular reactor 140, stream 131 may be further polymerized and exit the tubular reactor 140 as polymerized stream 141.

[0032] According to an embodiment, polymerization can be initiated in the autoclave reactor 130 and the tubular reactor 140 with the aid of four mixtures, each containing one or more free radical initiation systems that can be injected at the inlet of each reaction zone. A first peroxide initiator stream 124 can be introduced into zone one 130A of the autoclave reactor 130. A second peroxide initiator stream 123 can be introduced into zone two 130B of the autoclave reactor 130. A third peroxide initiator stream 125 can be introduced into zone three 130C of the autoclave reactor 130. Finally, a fourth peroxide initiator stream 132 can be introduced into the tubular reactor 140.

[0033] The polymer stream 141 is introduced into a high-pressure separator 150, which is in turn connected to a tubular reactor 140 located upstream of the high-pressure separator 150 and in turn connected to a low-pressure separator 160. At the high-pressure separator 150, the polymer stream 141 is separated into an ethylene-rich stream 152 and a polymer-rich stream 151. A first portion of the ethylene-rich stream 153 is purged from the process reaction system 100, and a second portion of the ethylene-rich stream 154 is cooled and recycled back to the hypercompressor 120, where the ethylene-rich stream 152 is mixed with the compressed stream 111 introduced into the hypercompressor 120.

[0034] The feed stream 151 rich in polymer is introduced into low-pressure separator 160, and this low-pressure separator is connected with the high-pressure separator 150 that is positioned at low-pressure separator 160 upstreams in sequence, and is connected with the booster / one-stage compressor 110 that is positioned at low-pressure separator 160 downstreams in sequence.At low-pressure separator 160 place, the feed stream 151 rich in polymer is separated into the second feed stream 161 rich in polymer and the second feed stream 162 rich in ethylene.The second feed stream 161 rich in polymer leaves process reaction system 100, can be introduced into forcing machine (not shown) then.The second feed stream 162 rich in ethylene mixes with fresh ethylene feed stream 101, is introduced into the booster / one-stage compressor 110 that is connected with low-pressure separator 160 in sequence then.

[0035] According to an embodiment, the initiator may be selected from tert-butyl peroxypivalate (TBPIV), tert-butyl peroxy-2-ethylhexanoate (TBPO), tert-butyl peroxyacetate (TBPA), di-tert-butyl peroxide (DTBP), and mixtures thereof.

[0036] LDPE properties of the implementation scheme

[0037] Provide the Low Density Polyethylene (LDPE) with enhanced melt strength and expected melt index and density or modulus in the embodiment disclosed and described herein.The characteristic of the Low Density Polyethylene (LDPE) according to the embodiment disclosed and described herein will be provided now.Although the character listed below is narrated in independent paragraph, it should be understood that, by revising the various processing conditions discussed above, any character from any paragraph below can with any other character combination from any paragraph below.Therefore, envisioned Low Density Polyethylene (LDPE) and these Low Density Polyethylene (LDPE) with any combination of the various characteristics listed below can be prepared according to embodiment.

[0038] According to an embodiment, the density of the low density polyethylene may be greater than or equal to 0.9210 g / cm3 (g / cm 3 ) and less than or equal to 0.9275g / cm 3 Density measurements are made using ASTM D792-08 Method B within one hour of sample pressing. In embodiments, the density of the low density polyethylene is greater than or equal to 0.9215 g / cm 3 and less than or equal to 0.9270 g / cm 3 , greater than or equal to 0.9220g / cm 3 and less than or equal to 0.9265g / cm 3 , greater than or equal to 0.9225g / cm 3 and less than or equal to 0.9260 g / cm 3 , greater than or equal to 0.9230g / cm 3and less than or equal to 0.9255g / cm 3 , greater than or equal to 0.9235g / cm 3 and less than or equal to 0.9250g / cm 3 , or greater than or equal to 0.9240 g / cm 3 and less than or equal to 0.9245 g / cm 3 .

[0039] In an embodiment, the low density polyethylene has a melt index (I2) greater than, or equal to, 4.5 grams per 10 minutes (g / 10 min), such as greater than, or equal to, 4.6 g / 10 min, greater than, or equal to, 4.7 g / 10 min, greater than, or equal to, 4.8 g / 10 min, greater than, or equal to, 4.9 g / 10 min, greater than, or equal to, 5.0 g / 10 min, greater than, or equal to, 5.1 g / 10 min, greater than, or equal to, 5.2 g / 10 min, greater than, or equal to, 5.3 g / 10 min, greater than, or equal to, 5.4 g / 10 min, greater than, or equal to, 5.5 g / 10 min, greater than, or equal to, 5.6 g / 10 min, greater than, or equal to, 5.7 g / 10 min, greater than, or equal to, 5.8 g / 10 min, greater than, or equal to, 5.9 g / 10 min, or greater than, or equal to, 6.0 g / 10 min, as measured in accordance with ASTM D 1238 at 190°C and under a load of 2.16 kg. In embodiments, the melt index (I2) is less than, or equal to, 7.5 g / 10 min, such as less than, or equal to, 7.4 g / 10 min, less than, or equal to, 7.3 g / 10 min, less than, or equal to, 7.2 g / 10 min, less than, or equal to, 7.1 g / 10 min, less than, or equal to, 7.0 g / 10 min, less than, or equal to, 6.9 g / 10 min, less than, or equal to, 6.8 g / 10 min, less than, or equal to, 6.7 g / 10 min, less than, or equal to, 6.6 g / 10 min, less than, or equal to, 6.5 g / 10 min, less than, or equal to, 6.4 g / 10 min, less than, or equal to, 6.3 g / 10 min, less than, or equal to, 6.2 g / 10 min, or less than, or equal to, 6.1 g / 10 min.In an embodiment, the melt index (I2) is greater than, or equal to, 4.5 g / 10 min and less than, or equal to, 7.5 g / 10 min, such as greater than, or equal to, 4.6 g / 10 min and less than, or equal to, 7.5 g / 10 min, greater than, or equal to, 4.7 g / 10 min and less than, or equal to, 7.5 g / 10 min, greater than, or equal to, 4.8 g / 10 min and less than, or equal to, 7.5 g / 10 min, greater than, or equal to, 4.9 g / 10 min and less than, or equal to, 7.5 g / 10 min, greater than, or equal to, 5.0 g / 10 min and less than, or equal to, 7.5 g / 10 min, greater than, or equal to, 5.1 g / 10 min and less than, or equal to, 7.5 g / 10 min, greater than, or equal to, 5.2 g / 10 min and less than, or equal to, 7. g / 10min, greater than or equal to 5.5 g / 10min and less than or equal to 7.5 g / 10min, greater than or equal to 5.6 g / 10min and less than or equal to 7.5 g / 10min, greater than or equal to 5.7 g / 10min and less than or equal to 7.5 g / 10min, greater than or equal to 5.8 g / 10min and less than or equal to 7.5 g / 10min, greater than or equal to 5.9 g / 10min and less than or equal to 7.5 g / 10min, or greater than or equal to 6.0 g / 10min and less than or equal to 7.5 g / 10min. In embodiments, the melt index (I2) is greater than or equal to 4.5 g / 10 min and less than or equal to 7.0 g / 10 min, such as greater than or equal to 5.0 g / 10 min and less than or equal to 6.5 g / 10 min, or about 6.0 g / 10 min.

[0040] Melt strength is measured using a Rheotens attached to a capillary rheometer as disclosed below. In embodiments, the melt strength is greater than or equal to 5.5 centinewtons (cN), such as greater than or equal to 5.6 cN, greater than or equal to 5.7 cN, greater than or equal to 5.8 cN, greater than or equal to 5.9 cN, greater than or equal to 6.0 cN, greater than or equal to 6.1 cN, greater than or equal to 6.2 cN, greater than or equal to 6.3 cN, greater than or equal to 6.4 cN, greater than or equal to 6.5 cN, greater than or equal to 6.6 cN, greater than or equal to 6.7 cN, greater than or equal to 6.8 cN, greater than or equal to 6 ...1 cN, greater than or equal to 6.2 cN, greater than or equal to 6.3 cN, greater than or equal to 6.4 cN, greater than or equal to 6.5 cN, greater than or equal to 6.6 cN, greater than or equal to 6.7 cN, greater than or equal to 6.8 cN, greater than or equal to 6.9 cN, greater than or equal to 6.9 cN, greater than or equal to 6.1 cN, greater than or equal to 6.2 cN, greater than or equal to 6.3 cN, greater than or equal to 6.4 cN equal to 6.9 cN, greater than or equal to 7.0 cN, greater than or equal to 7.1 cN, greater than or equal to 7.2 cN, greater than or equal to 7.3 cN, greater than or equal to 7.4 cN, greater than or equal to 7.5 cN, greater than or equal to 7.6 cN, greater than or equal to 7.7 cN, greater than or equal to 7.8 cN, greater than or equal to 7.9 cN, greater than or equal to 8.0 cN, greater than or equal to 8.1 cN, greater than or equal to 8.2 cN, greater than or equal to 8.3 cN, or greater than or equal to 8.4 cN.In an embodiment, the melt strength is greater than or equal to 5.5 cN and less than or equal to 8.5 cN, such as greater than or equal to 5.6 cN and less than or equal to 8.5 cN, greater than or equal to 5.7 cN and less than or equal to 8.5 cN, greater than or equal to 5.8 cN and less than or equal to 8.5 cN, greater than or equal to 5.9 cN and less than or equal to 8.5 cN, greater than or equal to 6.0 cN and less than or equal to 8.5 cN, greater than or equal to 6.1 cN and less than or equal to 8.5 cN, greater than or equal to 6.6 cN and less than or equal to 8.5 cN, greater than or equal to 6.7 cN and less than or equal to 8.5 cN, greater than or equal to 6.8 cN and less than or equal to 8.5 cN, greater than or equal to 6.9 ... 6.2 cN and less than or equal to 8.5 cN, 6.3 cN and less than or equal to 8.5 cN, 6.4 cN and less than or equal to 8.5 cN, 6.5 cN and less than or equal to 8.5 cN, 6.6 cN and less than or equal to 8.5 cN, 6.7 cN and less than or equal to 8.5 cN, 6.8 cN and less than or equal to 8.5 cN, 6.9 cN and less than or equal to 8.5cN, greater than or equal to 7.0cN and less than or equal to 8.5cN, greater than or equal to 7.1cN and less than or equal to 8.5cN, greater than or equal to 7.2cN and less than or equal to 8.5cN, greater than or equal to 7.3cN and less than or equal to 8.5cN, greater than or equal to 7.4cN and less than or equal to 8.5cN, greater than or equal to 7.5cN and less than or equal to 8.5cN, greater than or equal to 7.6cN and less than or equal to 8.5cN, greater than or equal to 7.7cN N and less than or equal to 8.5cN, greater than or equal to 7.8cN and less than or equal to 8.5cN, greater than or equal to 7.9cN and less than or equal to 8.5cN, greater than or equal to 8.0cN and less than or equal to 8.5cN, greater than or equal to 8.1cN and less than or equal to 8.5cN, greater than or equal to 8.2cN and less than or equal to 8.5cN, greater than or equal to 8.3cN and less than or equal to 8.5cN, or greater than or equal to 8.4cN and less than or equal to 8.5cN.In an embodiment, the melt strength is greater than or equal to 5.5 cN and less than or equal to 8.5 cN, such as greater than or equal to 5.5 cN and less than or equal to 8.3 cN, greater than or equal to 5.5 cN and less than or equal to 8.2 cN, greater than or equal to 5.5 cN and less than or equal to 8.1 cN, greater than or equal to 5.5 cN and less than or equal to 8.0 cN, greater than or equal to 5.5 cN and less than or equal to 7.9 cN, greater than or equal to 5.5 cN and less than or equal to 7. 8cN, greater than or equal to 5.5cN and less than or equal to 7.7cN, greater than or equal to 5.5cN and less than or equal to 7.6cN, greater than or equal to 5.5cN and less than or equal to 7.5cN, greater than or equal to 5.5cN and less than or equal to 7.4cN, greater than or equal to 5.5cN and less than or equal to 7.3cN, greater than or equal to 5.5cN and less than or equal to 7.2cN, greater than or equal to 5.5cN and less than or equal to 7.1cN, greater than or equal to 5.5cN and less than or equal to 7.0cN, greater than or equal to 5.5cN and less than or equal to 6.9cN, greater than or equal to 5.5cN and less than or equal to 6.8cN, greater than or equal to 5.5cN and less than or equal to 6.7cN, greater than or equal to 5.5cN and less than or equal to 6.6cN, greater than or equal to 5.5cN and less than or equal to 6.5cN, greater than or equal to 5.5cN and less than or equal to 6.4cN, greater than or equal to 5.5cN and less than or equal to According to an embodiment, the melt strength is greater than or equal to 5.5 cN and less than or equal to 8.5 cN, such as greater than or equal to 6.0 cN and less than or equal to 8.0 cN, greater than or equal to 6.0 cN and less than or equal to 7.5 cN, greater than or equal to 6.4 cN and less than or equal to 7.0 cN, or greater than or equal to 6.4 cN and less than or equal to 6.8 cN.

[0041] According to embodiments, the relationship between melt strength and melt index may be such that the melt strength in cN measured at 190°C may be determined by the following expression:

[0042] Melt strength (cN) ≥ [-0.780*(melt index, I2) + 9.9cN] ± 5%

[0043] Alternatively, the melt strength measured at 190°C can be determined by the following alternative expression:

[0044] Melt strength (cN) ≥ [-0.780*(melt index, I2) + 10.3cN] ± 5%

[0045] According to an embodiment, the low density polyethylene has a hexane extractables content of less than or equal to 2.60 weight percent (wt %), such as less than or equal to 2.50 wt %, less than or equal to 2.40 wt %, less than or equal to 2.30 wt %, less than or equal to 2.20 wt %, less than or equal to 2.10 wt %, less than or equal to 2.00 wt %, less than or equal to 1.90 wt %, less than or equal to 1.80 wt %, less than or equal to 1.70 wt %, less than or equal to 1.60 wt %, less than or equal to 1.50 wt %, or less than or equal to 1.40 wt %. In an embodiment, the extractables of the low density polyethylene as measured using the hexane method are greater than or equal to 0.50 wt% and less than or equal to 2.60 wt%, such as greater than or equal to 0.60 wt% and less than or equal to 2.50 wt%, greater than or equal to 0.70 wt% and less than or equal to 2.40 wt%, greater than or equal to 0.80 wt% and less than or equal to 2.30 wt%, greater than or equal to 0.90 wt% and less than or equal to 2.30 wt%, greater than or equal to 1.00 wt% and less than or equal to 2.20 wt%, greater than or equal to 0.80 wt% and less than or equal to 2.30 wt%, greater than or equal to 0.90 wt% and less than or equal to 2.30 wt%, greater than or equal to 1.00 wt% and less than or equal to 2.20 wt%, greater than or equal to 0.80 wt% and less than or equal to 2.20 wt%, greater than or equal to 0.90 wt% and less than or equal to 2.30 wt%, greater than or equal to 1.00 wt% and less than or equal to 2.20 wt%, greater than or equal to 0.80 wt% and less than or equal to 2.3 ...80 wt% and less than or equal to 2.30 wt%, greater than or equal to 1.00 wt% and less than or equal to 2.20 wt%, greater % and less than or equal to 2.10 wt%, greater than or equal to 1.20 wt% and less than or equal to 2.00 wt%, greater than or equal to 1.20 wt% and less than or equal to 1.90 wt%, greater than or equal to 1.20 wt% and less than or equal to 1.80 wt%, greater than or equal to 1.20 wt% and less than or equal to 1.70 wt%, greater than or equal to 1.20 wt% and less than or equal to 1.60 wt%, greater than or equal to 1.20 wt% and less than or equal to 1.50 wt%, or approximately 1.40 wt%.

[0046] According to an embodiment, the low density polyethylene has a number average molecular weight (Mn(conv)) greater than or equal to 12,000 grams per mole (g / mol) and less than or equal to 18,500 g / mol, such as greater than or equal to 13,000 g / mol and less than or equal to 18,500 g / mol, greater than or equal to 14,000 g / mol and less than or equal to 17,000 g / mol, greater than or equal to 14,000 g / mol and less than or equal to 17,000 g / mol, or about 14,500 g / mol, as measured by conventional GPC methods. Mn(conv) is measured according to the gel permeation chromatography (GPC) protocol (conv) disclosed herein.

[0047] According to embodiments, the low density polyethylene has a weight average molecular weight (Mw(conv)) greater than, or equal to, 110,000 grams per mole (g / mol) and less than, or equal to, 140,000 g / mol, such as greater than, or equal to, 115,000 g / mol and less than, or equal to, 135,000 g / mol, greater than, or equal to, 117,500 g / mol and less than, or equal to, 130,000 g / mol, or about 125,000 g / mol, as measured by conventional GPC methods. Mw(conv) is measured according to conventional GPC protocols disclosed herein.

[0048] According to an embodiment, the low density polyethylene has a z-average molecular weight (Mz(conv)) as measured by conventional GPC methods greater than or equal to 500,000 grams per mole (g / mol), such as greater than or equal to 500,000 g / mol and less than or equal to 650,000 g / mol, such as greater than or equal to 510,000 g / mol and less than or equal to 640,000 g / mol, greater than or equal to 520,000 g / mol and less than or equal to 630,000 g / mol, greater than or equal to 530,000 g / mol and less than or equal to 640,000 g / mol, greater than or equal to 550,000 g / mol and less than or equal to 650,000 g / mol, The Mz(conv) is measured according to the conventional GPC protocol disclosed herein.

[0049] In an embodiment, the low density polyethylene has a molecular weight distribution (Mw(conv) / Mn(conv)) greater than, or equal to, 7.2, such as greater than, or equal to, 7.3, greater than, or equal to, 7.4, or greater than, or equal to, 7.5, as measured by conventional GPC methods. In an embodiment, Mw(conv) / Mn(conv) less than, or equal to, 9.5, such as less than, or equal to, 9.0, less than, or equal to, 8.8, less than, or equal to, 8.6, or less than, or equal to, 8.2.

[0050] According to embodiments, the low density polyethylene has a weight average molecular weight Mw(abs) greater than or equal to 225,000 g / mol and less than or equal to 325,000 g / mol, greater than or equal to 235,000 g / mol and less than or equal to 315,000 g / mol, greater than or equal to 245,000 g / mol and less than or equal to 305,000 g / mol, greater than or equal to 255,000 g / mol and less than or equal to 295,000 g / mol, greater than or equal to 265,000 g / mol and less than or equal to 285,000 g / mol, or about 275,000 g / mol, as measured according to the absolute GPC protocol disclosed herein.

[0051] According to an embodiment, the low density polyethylene has a ratio of the weight average molecular weight measured according to the absolute method to the weight average molecular weight measured according to the conventional GPC method disclosed herein (Mw(abs) / Mw(conv)) greater than, or equal to, 2.1 and less than, or equal to, 2.7, such as greater than, or equal to, 2.1 and less than, or equal to, 2.4, or greater than, or equal to, 2.15 and less than, or equal to, 2.35.

[0052] According to an embodiment, the low density polyethylene has a GPC branching ratio (gpcBR) greater than, or equal to, 2.3 and less than, or equal to, 3.2, such as greater than, or equal to, 2.4 and less than, or equal to, 3.1, greater than, or equal to, 2.5 and less than, or equal to, 3.0, or greater than, or equal to, 2.6 and less than, or equal to, 2.9, as measured using the absolute technique disclosed herein.

[0053] According to an embodiment, the light scattering properties (LSP) of the low density polyethylene is less than 3.8, such as less than or equal to 3.7, less than or equal to 3.6, or less than or equal to 3.5. In an embodiment, the LSP is greater than or equal to 2.5, greater than or equal to 2.6, or greater than or equal to 2.7. In an embodiment, the LSP is greater than or equal to 2.5 and less than or equal to 3.5, such as greater than or equal to 2.6 and less than or equal to 3.4, or greater than or equal to 2.7 and less than or equal to 3.3.

[0054] In an embodiment, the low density polyethylene has a viscosity greater than or equal to 2,250 Pa·s and less than or equal to 4,250 Pa·s, such as greater than or equal to 2,400 Pa·s and less than or equal to 4,000 Pa·s, greater than or equal to 2,600 Pa·s and less than or equal to 3,800 Pa·s, greater than or equal to 2,800 Pa·s and less than or equal to 3,600 Pa·s, or greater than or equal to 2,900 Pa·s and less than or equal to 3,400 Pa·s, or about 3,200 Pa·s, as measured at 0.1 radian / second (rad / s) and 190° C. The viscosity is measured according to the protocols disclosed herein.

[0055] In an embodiment, the low density polyethylene has a viscosity greater than or equal to 250 Pa·s and less than or equal to 400 Pa·s, such as greater than or equal to 270 Pa·s and less than or equal to 380 Pa·s, greater than or equal to 290 Pa·s and less than or equal to 360 Pa·s, or about 320 Pa·s, as measured at 100 rad / s and 190° C. The viscosity is measured according to the protocols disclosed herein.

[0056] In an embodiment, the low density polyethylene has a ratio of the viscosity measured at 0.1 rad / sec and 190°C to the viscosity measured at 100 rad / sec and 190°C (V@0.1 and 190°C / V@100 and 190°C) greater than, or equal to, 8.0, such as greater than, or equal to, 8.5, greater than, or equal to, 9.0, or greater than, or equal to, 9.5. In an embodiment, the ratio of the viscosity measured at 0.1 rad / sec and 190°C to the viscosity measured at 100 rad / sec and 190°C is greater than, or equal to, 8.0 and less than, or equal to, 12.0, such as greater than, or equal to, 8.5 and less than, or equal to, 11.0, greater than, or equal to, 9.0 and less than, or equal to, 10.5, or greater than, or equal to, 9.2 and less than, or equal to, 10.8.

[0057] In an embodiment, the infrared spectroscopy cumulative distribution fraction (CDF) at a molecular weight of less than 5,000 g / mol (CDF IR ) is less than or equal to 0.081, such as less than or equal to 0.079, less than or equal to 0.077, less than or equal to 0.075, less than or equal to 0.073, or less than or equal to 0.071. In embodiments, the CDF at a molecular weight of less than 5,000 g / mol IR Greater than or equal to 0.040 and less than or equal to 0.081, such as greater than or equal to 0.040, such as greater than or equal to 0.055 and less than or equal to 0.079, greater than or equal to 0.055 and less than or equal to 0.077, greater than or equal to 0.055 and less than or equal to 0.075, greater than or equal to 0.055 and less than or equal to 0.075.

[0058] In embodiments, the CDF at molecular weights greater than 200,000 g / mol IR Greater than or equal to 0.135, such as greater than or equal to 0.145, greater than or equal to 0.150, greater than or equal to 0.155, or greater than or equal to 0.160. In embodiments, the CDF at a molecular weight greater than 200,000 g / mol IR Greater than or equal to 0.135 and less than or equal to 0.180, such as greater than or equal to 0.145 and less than or equal to 0.175, greater than or equal to 0.150 and less than or equal to 0.170, or greater than or equal to 0.155 and less than or equal to 0.163.

[0059] In embodiments, the CDF (CDF) of the viscometer analysis at a molecular weight of less than 25,000 g / mol DV ) is less than or equal to 0.130, such as less than or equal to 0.127, less than or equal to 0.126, less than or equal to 0.125, less than or equal to 0.123, less than or equal to 0.121, or less than or equal to 0.119. In embodiments, the CDF at a molecular weight of less than 25,000 g / mol DV Greater than or equal to 0.050 and less than or equal to 0.130, such as greater than or equal to 0.100 and less than or equal to 0.128, greater than or equal to 0.110 and less than or equal to 0.125, or greater than or equal to 0.115 and less than or equal to 0.126.

[0060] In embodiments, the CDF at molecular weights greater than 1,000,000 g / mol DV Greater than or equal to 0.042, such as greater than or equal to 0.048, greater than or equal to 0.053, greater than or equal to 0.058, or greater than or equal to 0.061. In embodiments, the CDF at a molecular weight greater than 1,000,000 g / mol DV Greater than or equal to 0.042 and less than or equal to 0.070, such as greater than or equal to 0.048 and less than or equal to 0.065, or greater than or equal to 0.053 and less than or equal to 0.064.

[0061] In embodiments, the light scattering analysis cumulative distribution fraction (CDF) at molecular weights less than 100,000 g / mol (CDF LS ) is less than or equal to 0.140, such as less than or equal to 0.130, less than or equal to 0.120, or less than or equal to 0.110. In an embodiment, the CDF at a molecular weight of less than 100,000 g / mol LSGreater than or equal to 0.075 and less than or equal to 0.140, such as greater than or equal to 0.085 and less than or equal to 0.130, or greater than or equal to 0.095 and less than or equal to 0.115.

[0062] In embodiments, the CDF at molecular weights greater than 1,500,000 g / mol LS Greater than or equal to 0.110, such as greater than or equal to 0.120, greater than or equal to 0.130, greater than or equal to 0.135, greater than or equal to 0.140, or greater than or equal to 0.145. In embodiments, the CDF at a molecular weight greater than 1,500,000 g / mol LS Greater than or equal to 0.110 and less than or equal to 0.160, such as greater than or equal to 0.120 and less than or equal to 0.155, or greater than or equal to 0.130 and less than or equal to 0.155.

[0063] In an embodiment, as by 13 The low density polyethylene has greater than or equal to 1.5 pentyl groups (C5) per 1000 total carbon atoms and less than or equal to 3.0 pentyl groups (C5) per 1000 total carbon atoms as determined by C NMR.

[0064] In an embodiment, the polymer has no C1 branches (methyl branches) per 1000 total carbon atoms.

[0065] In an embodiment, the low density polyethylene has greater than or equal to 1.5 1,3-diethyl branches per 1000 total carbon atoms and less than or equal to 5.0 1,3-diethyl branches per 1000 total carbon atoms.

[0066] In an embodiment, the low density polyethylene has greater than or equal to 3.0 C 6+ Branched chain / 1000 total carbon atoms and less than or equal to 4.0 C 6+ Branches / 1000 total carbon atoms.

[0067] In an embodiment, the low density polyethylene has greater than or equal to 0.018 vinyl groups per 1000 total carbon atoms and less than or equal to 0.043 vinyl groups per 1000 total carbon atoms.

[0068] In embodiments, the low density polyethylene has greater than or equal to 0.01 cis and trans groups (vinylidene) per 1000 total carbon atoms and less than or equal to 0.03 cis and trans groups (vinylidene) per 1000 total carbon atoms.

[0069] In an embodiment, the low density polyethylene has greater than or equal to 0.05 vinylidene groups per 1000 total carbon atoms and less than or equal to 0.25 vinylidene groups per 1000 total carbon atoms.

[0070] additive

[0071] The composition of the embodiment may include one or more additives. Additives include stabilizers, plasticizers, antistatic agents, pigments, dyes, nucleating agents, fillers, slip agents (such as erucamide, oleamide and stearamide), flame retardants, processing aids, smoke suppressants, viscosity modifiers, antiblocking agents (including talc and silica) and oils (such as mineral oil). Based on the weight of the low density polyethylene of the embodiment, the polymer composition may, for example, include less than 10% (by combined weight) of one or more additives. In an embodiment, the low density polyethylene may be treated with one or more stabilizers, such as antioxidants, such as IRGANOX 1010, IRGANOX 1076 and IRGAFOS 168 (BASF). It should be understood that in an embodiment, no stabilizer is used.

[0072] Blending and mixing of the low density polyethylene of the embodiments with other polymers can be performed. Polymers suitable for blending with the low density polyethylene of the embodiments include natural and synthetic polymers. Exemplary polymers for blending include: propylene-based polymers (both impact-modified polypropylene, isotactic polypropylene, atactic polypropylene, and random ethylene / propylene copolymers); various types of ethylene-based polymers, including high pressure free radical LDPE, LLDPE prepared with Ziegler-Natta catalysts, PE prepared with single-site catalysts (including multi-reactor PE ("in-reactor" blends of Ziegler-Natta PE and single-site catalyzed PE, such as USP 6,545,088 (Kolthammer et al.), 6,538,070 (Cardwell et al.), 6,566,446 (Parikh et al.), 5,844,045 (Kolthammer et al.), 5,869,575 (Kolthammer et al.), and 6,448,341 (Kolthammer et al.)), EVA, ethylene / vinyl alcohol copolymers, polystyrene, impact-modified polystyrene, ABS, styrene / butadiene block copolymers and their hydrogenated derivatives (SBS and SEBS), and thermoplastic polyurethanes. Homogeneous polymers such as olefin plastomers and elastomers, ethylene-based and propylene-based copolymers (e.g., those sold under the trade name VERSIFY TMPlastomers and elastomers (polymers obtained from The Dow Chemical Company and VISTAMAXX (ExxonMobil Chemical Co.)) can also be used as a component in blends containing low density polyethylene of the embodiments. LLDPE, such as INNATE TM 、DOWLEX TM and DOWLEX TM gM (The Dow Chemical Company) and Exceed and Exceed XP (Exxon Chemical Company).

[0073] Additive such as slip additive, antioxidant or antiblocking agent can affect resin characteristics.In addition, the oil such as mineral oil that can be used as the carrier of additive also can affect resin characteristics.Can use the whole bag of tricks to analyze low density polyethylene to determine the existence of additive, these methods comprise slip additive method, main and secondary antioxidant method, antiblocking agent method and mineral oil method, as further described below.

[0074] The existence of additive may have an impact on molecular weight, hexane extractables and density.For example, the low molecular weight characteristics of additive can reduce the molecular weight based on ethylene polymer.Therefore, as described in detail herein, in the low molecular weight region of GPC elution curve, when there is the peak known to be caused by the presence of antioxidant or other additives, the existence of such peak can cause underestimating the number average molecular weight (Mn) of polymer sample, thereby providing the overestimation of the sample polydispersity defined as Mw / Mn, wherein Mw is weight average molecular weight.Similarly, when there is additive, hexane extractables will be measured to include all hexane soluble additives, but hexane extractables will not include the additive that is insoluble in hexane, such as antiblocking agent.Therefore, the hexane extractables percentage ratio of the resin with additive will equal the summation of the percentage ratio of hexane extractables percentage ratio and hexane soluble additives (such as slipping agent and antioxidant) and / or any hexane soluble oil (such as the carrier that can be used as additive) based on ethylene polymer without additive.Finally, additive (such as antiblocking agent) can increase the density based on ethylene polymer. The density (in g / cm2) of the ethylene-based polymer without any additives (where the additive is an antiblocking agent such as talc or silica) 3 It can be represented by the following expression:

[0075]

[0076] application

[0077] The low density polyethylene of the embodiment can be used in a variety of conventional thermoplastic manufacturing processes to prepare useful articles, including monolayer and multilayer films; molded articles, such as blow molding, injection molding, casting or rotational molding products; coatings; fibers; and woven or nonwoven fabrics. The low density polyethylene of the embodiment can be used in various films, including but not limited to extrusion coatings, food packaging, consumer products, industry (application or film), agriculture (application or film), laminated films, fresh-cut manufacturing films, cast films, blown films, thermoformed films, meat films, cheese films, candy films, clear shrink films, collation shrink films, stretch films, silage films, greenhouse films, fumigation films, liner films, stretch hoods, heavy-duty shipping bags, pet food, sandwich bags, sealants, and diaper backsheets.

[0078] The low density polyethylene of the embodiments may also be used in other direct end-use applications. The low density polyethylene of the embodiments may be used in wire and cable coating operations, sheet extrusion for vacuum forming operations, and forming molded articles, including using injection molding, blow molding, or rotational molding processes. Other suitable applications for the low density polyethylene of the embodiments include elastic films and fibers; soft touch articles such as device handles; gaskets and profiles; automotive interior trim and profiles; foam articles (both open-cell and closed-cell); impact modifiers for other thermoplastic polymers such as high-density polyethylene or other olefin polymers; lid linings; and flooring.

[0079] In the embodiments disclosed and described herein, unless explicitly mentioned otherwise, the low density polyethylene is a low density polyethylene without additives, and unless disclosed otherwise, the properties disclosed herein are properties with respect to the low density polyethylene without additives.

[0080] Test Method

[0081] The test method includes the following aspects:

[0082] density

[0083] Samples for density measurement were prepared according to ASTM D 4703-10. The samples were pressed at 374°F (190°C) at 10,000 psi (68 MPa) for five minutes. The temperature was maintained at 374°F (190°C) for the five minutes, and then the pressure was increased to 30,000 psi (207 MPa) for three minutes. This was followed by a one-minute hold at 70°F (21°C) and 30,000 psi (207 MPa). Measurements were made using ASTM D792-08 Method B within one hour of sample compression.

[0084] Melt index

[0085] Melt flow index or melt index or I2 is measured according to ASTM D 1238-10, Condition 190°C / 2.16 kg, Method B, and is reported in grams eluted per 10 minutes.

[0086] Nuclear magnetic resonance (NMR) 13 C NMR)

[0087] The samples were prepared by adding approximately 3 g of 1,1,2,2-tetrachloroethane (TCE) containing 12 wt% TCE-d2 and 0.025 M Cr(AcAc)3 to 0.25 g to 0.40 g of polymer sample in a 10 mm NMR tube. Oxygen was removed from the sample by purging the tube headspace with nitrogen. The sample was then dissolved and homogenized by heating the tube and its contents to 120-140°C using a heating block and a heat gun. Each dissolved sample was visually inspected to ensure homogeneity. The sample was thoroughly mixed immediately before analysis and was not allowed to cool before being inserted into the heated NMR sample holder.

[0088] All data were collected using a Bruker 600 MHz spectrometer equipped with a 10 mm extended temperature freezer. Data were collected at a sample temperature of 120°C using a 7.8 second pulse repetition delay, a 90 degree flip angle, and inverse gated decoupling. All measurements were performed in locked mode on non-rotating samples. The samples were allowed to thermally equilibrate for seven minutes before data collection. 13C NMR chemical shifts were internally referenced to the EEE triad at 30.0 ppm. "C 6+ " value is the C 6+ A direct measure of chain branching, where long branches are not distinguished from "chain ends". The "32.2 ppm" peak representing the third carbon from the end of all chains or branches of six or more carbons is used to determine the "C 6+ "value.

[0089] Table 1: Branching types and 13C NMR integration ranges used for quantification

[0090]

[0091] Nuclear magnetic resonance (NMR) 1 H NMR)

[0092] Samples were prepared by adding approximately 120 mg of a 50 / 50 solution of tetrachloroethane-d2 / perchloroethylene (50 / 50 by weight) to 3.25 g of 0.001 M Cr(AcAc)3 in a 10 mm NMR tube. The samples were purged by bubbling N2 through the solvent for approximately five minutes via a pipette inserted into the tube to prevent oxidation. Each tube was capped and sealed with TEFLON tape. The samples were heated and vortexed at 110-115°C to ensure homogeneity.

[0093] The measurements were performed on a Bruker 600 MHz spectrometer equipped with a 10 mm extended temperature freezer. 1 H NMR. Data were collected with a 2G pulse, 64 scans, a pulse repetition delay of 15.8 seconds, and a sample temperature of 120°C.

[0094] The signals from about 3 to -0.5 ppm of the entire polymer were set to an arbitrary value, typically 20,000. The corresponding integrals were obtained for unsaturation (vinylene at about 5.40 to 5.60 ppm, trisubstituted at about 5.16 to 5.35 ppm, vinyl at about 4.95 to 5.15 ppm, and vinylidene at about 4.70 to 4.90 ppm).

[0095] The integral of the entire polymer from the control experiment is divided by two to obtain a value representing X thousand carbons (ie, if polymer integral = 20,000, this represents 10,000 carbons, and X = 10).

[0096] The unsaturation integral divided by the corresponding number of protons contributing to the integral represents the number of moles of each type of unsaturation per X thousand carbons. The number of moles of each type of unsaturation divided by X gives the number of moles of unsaturation per 1,000 moles of carbons.

[0097] Melt strength

[0098] Melt strength measurements are made on a Rheotester 2000 capillary rheometer Rheotens 71.97( Melt samples (about 25 to 30 grams) were collected using a flat entry angle (180 degrees) tweezers equipped with a 30 mm long, 2.0 mm diameter, and an aspect ratio (length / diameter) of 15. The sample was fed into a Rheotester 2000 capillary rheometer. After equilibrating the sample at 190°C for 10 minutes, the piston was operated at a constant piston speed of 0.265 mm / s. The standard test temperature was 190°C. The sample was uniaxially stretched to a set of accelerating nipples located 100 mm below the die at an acceleration of 2.4 mm / s. 2 The tensile force was recorded as a function of the take-up speed of the rollers. The melt strength was reported as the average plateau force (cN) before the chain broke. The following conditions were used in the melt strength measurements: plunger speed = 0.265 mm / s; wheel acceleration = 2.4 mm / s 2 ; Capillary diameter = 2.0 mm; Capillary length = 30 mm; and Barrel diameter = 12 mm.

[0099] Dynamic Mechanical Spectroscopy (DMS)

[0100] The resin was compression molded into 3 mm thick x 1 inch circular sheets at 25,000 psi pressure in air at 177° C. for five minutes. The samples were then removed from the press and placed on a counter to cool.

[0101] Use TA Instruments " Advanced Rheological Extension System (ARES) " equipped with 25mm (diameter) parallel plates to carry out constant temperature frequency sweep under nitrogen purge. Sample is placed on plate and is melted at 190 ℃ for five minutes. It is subsequently " 2mm " that plate is made close to gap, trim sample (remove the extra sample that extends beyond the periphery of " 25mm diameter " plate), and start test subsequently. Described method is additionally provided with five minutes delay, to allow temperature equilibrium. Experiment is carried out at 190 ℃ in the frequency range of 0.1 radian / second to 100 radian / second. Strain amplitude is constant at 10%. From these data, calculate complex viscosity η*, tan (δ) or tan δ, viscosity (V0.1) under 0.1 radian / second, viscosity (V100) under 100 radian / second and viscosity ratio (V0.1 / V100).

[0102] GPC

[0103] Triple Detector Gel Permeation Chromatography (TDGPC)

[0104] The chromatography system consists of a PolymerCharg PC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5) and 4 capillary viscometers (DV) connected to a Precision Detectors (now Agilent Technologies) 2-angle laser scattering (LS) detector model 2040. For all light scattering measurements, a 15-degree angle was used for measurement purposes. The autosampler oven chamber was set to 160 degrees Celsius, and the column chamber was set to 150 degrees Celsius. The columns used were 4 Agilent "Mixed A" 30 cm 20-micron linear mixed bed columns and a 20 μm pre-column. The chromatographic solvent used was 1,2,4 trichlorobenzene and contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters, and the flow rate was 1.0 ml / min.

[0105] Calibration and calculation of conventional molecular weight moments and distributions were performed according to the methods described in the conventional GPC procedures (using a 20 μm "Mixed A" column).

[0106] The systematic method for determining multi-detector bias was performed in a manner consistent with that published by Balke, Mourey et al. (Mourey and Balke, Chromatography Polym. Chapter 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym. Chapter 13, (1992)) using the PolymerCharg PCOne TM The software optimizes the triple detector log (MW and IV) results from broad homopolymer polyethylene standards (Mw / Mn>3) with the narrow standards column calibration results from the narrow standards calibration curve.As used herein, "MW" refers to molecular weight.

[0107] Absolute molecular weight data were obtained using PolymerCharg PC One TM The software was obtained in a manner consistent with that published by Zimm (Zimm, BH, J. Chem. Phys., 16, 1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scattering from Polymer Solutions, Elsevier, Oxford, NY (1987)). The total injected concentration used to determine the molecular weight was obtained based on the mass detector area and the mass detector constant, which was derived from a suitable linear polyethylene homopolymer or one of the polyethylene standards of known weight average molecular weight. The calculated molecular weight (using GPCOne TM ) is obtained using the light scattering constant of one or more polyethylene standards from the polyethylene standards mentioned below and a refractive index concentration coefficient dn / dc of 0.104. Typically, the mass detector response (IR5) and the light scattering constant (using GPCOne TM Viscometer calibration (using GPCOne TM The viscometer constant (measured using GPCOne) can be calculated using the method described by the manufacturer, or alternatively, by using the published value of a suitable linear standard such as Standard Reference Material (SRM) 1475a (available from the National Institute of Standards and Technology, NIST). TMObtained), which relates the specific viscosity area (DV) and injected mass used for the calibration standard to its intrinsic viscosity (IV). The chromatographic concentration was assumed to be low enough to eliminate the effect of resolving the second viral coefficient (the effect of concentration on molecular weight).

[0108] The absolute weight average molecular weight (Mw(Abs)) is calculated by dividing the light scattering (LS) integrated chromatogram (determined by the light scattering constant) by the mass recovered from the mass constant and mass detector (IR5) area (using GPCOne TM The molecular weight and intrinsic viscosity responses were extrapolated at the end of the chromatogram where the signal-to-noise ratio was low (using GPCOne TM ). Other corresponding moments Mn (Abs) and Mz (Abs) The calculation according to equation 1-2 is as follows:

[0109]

[0110]

[0111] Conventional GPC

[0112] The chromatography system consisted of a PolymerCharg PC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infrared detector (IR5) connected to a Precision Detector (now Agilent Technologies) 2-angle laser scattering (LS) detector model 2040. For all light scattering measurements, a 15-degree angle was used for measurement purposes. The autosampler oven chamber was set to 160 degrees Celsius, and the column chamber was set to 150 degrees Celsius. The columns used were four Agilent "Mixed A" 30 cm 20-micron linear mixed bed columns. The chromatographic solvent used was 1,2,4 trichlorobenzene containing 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters, and the flow rate was 1.0 ml / min.

[0113] The calibration of the GPC column set was performed using 21 polystyrene standards with narrow molecular weight distributions ranging from 580 g / mol to 8,400,000 g / mol, and arranged in 6 "cocktail" mixtures with at least ten times the molecular weight between the individual molecular weights. Standards were purchased from Agilent Technologies. For molecular weights equal to or greater than 1,000,000 g / mol, polystyrene standards were prepared at 0.025 g in 50 ml of solvent, and for molecular weights less than 1,000,000 g / mol, polystyrene standards were prepared at 0.05 g in 50 ml of solvent. The polystyrene standards were dissolved and gently stirred at 80 degrees Celsius for 30 minutes. Equation 1 was used to convert the polystyrene standard peak molecular weight into a polyethylene molecular weight (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6,621 (1968)):

[0114] MW 聚乙烯 =A×(Mw 聚乙烯 ) B (Equation 3)

[0115] Where MW is the molecular weight, the value of A is 0.4315 and B is equal to 1.0.

[0116] A fifth order polynomial was used to fit the calibration points to the corresponding polyethylene equivalents.Small adjustments to A (approximately 0.3950 to 0.440) were made to correct for column resolution and band broadening effects such that a linear homopolymer polyethylene standard was obtained at 120,000 Mw.

[0117] Total plate counts were performed on the GPC column set using decane (prepared as 0.04 g in 50 ml TCB). Plate counts (Equation 4) and symmetry (Equation 5) were measured for a 200 microliter injection volume according to the following equations:

[0118]

[0119] where RV is the retention volume in milliliters, peak width is in milliliters, peak maximum is the maximum height of the peak, and 1 / 2 height is the height of 1 / 2 the peak maximum.

[0120]

[0121] Wherein RV is the retention volume in milliliters and peak width is in milliliters, peak maximum is the maximum position of the peak, tenth height is 1 / 10 the height of the peak maximum, and wherein post-peak refers to the tail of the peak whose retention volume is later than the peak maximum, and wherein front-peak refers to the front of the peak whose retention volume is earlier than the peak maximum. The plate count of the chromatography system should be greater than 20,000 and the symmetry should be between 0.98 and 1.22.

[0122] The samples were prepared semi-automatically using the PolymerChar "Instrument Control" software, with a target sample weight of 2 mg / mL and solvent (containing 200 ppm BHT) added to a septum-capped vial previously sparged with nitrogen using a PolymerChar high-temperature autosampler. The samples were dissolved at 160 degrees Celsius for 2 hours with "low speed" shaking.

[0123] Based on the GPC results using the internal IR5 detector (measurement channel) of the PolymerCharg PC-IR chromatogram according to Equations 6-8, the TM Calculations of Mn(conv), Mw(conv), and Mz(conv) were performed using the IR software, the baseline-subtracted IR chromatogram at each equally spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve at point (i) according to Equation 1.

[0124]

[0125]

[0126]

[0127] In the low molecular weight region of the GPC elution curve, when there is a peak known to be caused by the presence of antioxidants or other additives, the presence of such a peak will lead to an underestimation of the number average molecular weight (Mn) of the polymer sample, thereby giving an overestimation of the sample polydispersity defined as Mw / Mn, where Mw is the weight average molecular weight. Therefore, the true polymer sample molecular weight distribution should be calculated from the GPC elution by excluding this additional peak. This process is commonly described as peak skimming in data processing programs in liquid chromatography analysis. In this method, this additional peak is skimmed from the GPC elution curve before performing the sample molecular weight calculation from the GPC elution curve. The plate count of the chromatography system should be greater than 24,000 and the degree of symmetry should be between 0.98 and 1.22.

[0128] To monitor the deviation over time, a flow rate marker (decane) was introduced into each sample via a micropump controlled by the PolymerCharg PC-IR system. This flow rate marker (FM) was used to linearly correct the pump flow rate for each sample (Flow Rate (Nominal)) by comparing the RV of the corresponding decane peak in the sample (RV(FM Sample)) with the RV of the decane peak in the narrow standard calibration (RV(FM Calibrated)). It was then assumed that any change in the decane marker peak time was related to a linear change in flow rate (Flow Rate (Effective)) throughout the run. In order to facilitate the highest accuracy measured for the RV of the flow marker peak, a least squares fitting procedure was used to fit the peak of the flow marker concentration chromatogram to a quadratic equation. The first derivative of the quadratic equation was then used to solve for the true peak position. After calibrating the system based on the flow marker peak, the effective flow rate (relative to the narrow standard calibration) was calculated as Equation 9. By PolymerCharg PC-IR TM The software completes the processing of the flow marker peaks.An acceptable flow rate correction is such that the effective flow rate should be within + / - 1% of the nominal flow rate.

[0129] Flow rate (effective) = flow rate (nominal) * (RV (FM calibrated) / RV (FM sample)) (Equation 9)

[0130] The systematic method for determining multi-detector bias was performed in a manner consistent with that published by Balke, Mourey et al. (Mourey and Balke, Chromatography Polym. Chapter 12, (1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, Chromatography Polym. Chapter 13, (1992)) using the PolymerCharg PCOne TM The software optimizes triple detector logarithmic (MW and IV) results from broad homopolymer polyethylene standards (Mw / Mn>3) with narrow standards column calibration results from a narrow standards calibration curve.

[0131] Absolute molecular weight data were obtained using PolymerCharg PC One TMThe software was obtained in a manner consistent with that published by Zimm (Zimm, BH, J. Chem. Phys., 16, 1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scattering from Polymer Solutions, Elsevier, Oxford, NY (1987)). The total injected concentration used to determine the molecular weight was obtained based on the mass detector area and the mass detector constant, which was derived from a suitable linear polyethylene homopolymer or one of the polyethylene standards of known weight average molecular weight. The calculated molecular weight (using GPCOne TM ) is obtained using the light scattering constant of one or more polyethylene standards from the polyethylene standards mentioned below and a refractive index concentration coefficient dn / dc of 0.104. In general, the mass detector response (IR5) and the light scattering constant (using GPCOne TM Determination) should be made from linear standards with a molecular weight exceeding approximately 50,000 g / mol.

[0132] CDF calculation method

[0133] IR5 measures the detector cumulative detector fraction (CDF) (“CDF IR ”), viscosity detector cumulative detector fraction (“CDF DV ”) and the low-angle laser scattering detector cumulative detector fraction (“CDF LS ”) is calculated by the following steps (for CDF IR , CDF DV and CDF LS , visually Figure 2 、 Figure 3 and Figure 4 express):

[0134] 1) Linear Flow The chromatogram was corrected based on the relative retention volume ratios between the sample and the air peaks of a consistent narrow standard cocktail.

[0135] 2) Correct the light scattering detector bias relative to the refractometer as described in the Gel Permeation Chromatography (GPC) section.

[0136] 3) Calculate the molecular weight at each retention volume (RV) data slice based on the polystyrene calibration curve as described in the gel permeation chromatography (GPC) section modified by a polystyrene to polyethylene conversion factor of approximately (0.3950-0.44).

[0137] 4) Baselines were subtracted from the light scattering and refractometer chromatograms, and integration windows were set using standard GPC practice to ensure that all low molecular weight retention volume ranges observed in the refractometer chromatogram were integrated in the light scattering chromatogram (thus setting the highest RV limit in each chromatogram to the same index). Any material corresponding to less than 150 g / mol in either chromatogram was not included in the integration.

[0138] 5) Calculate the IR5 measurement sensor cumulative detector fraction (CDF) based on its baseline-subtracted peak height (H) from high molecular weight to low molecular weight (low to high retention volume) at each data slice (j) according to Equations 10A, 10B, 10C, 10D, 10E, and 10F (CDF IR ), viscosity chromatogram cumulative detector fraction (CDF DV ) and low angle laser light scattering (LALLS) chromatogram cumulative detector fraction (CDF LS ) and shown in relation to Example 1 Figure 2 、 Figure 3 and Figure 4 :

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145] gpcBR branching index by triple detector GPC (3D-GPC)

[0146] The gpcBR branching index is determined by first calibrating the light scattering, viscosity, and concentration detectors as described above. The baseline is then subtracted from the light scattering, viscometer, and concentration chromatograms. The integration windows are then set to ensure integration of all low molecular weight retention volume ranges in the light scattering and viscometer chromatograms, which indicate the presence of detectable polymer from the infrared (IR5) chromatogram. Linear polyethylene standards are then used to establish polyethylene and polystyrene Mark-Houwink constants. After obtaining the constants, these two values ​​are used to construct two linear reference conventional calibration values ​​for polyethylene molecular weight and polyethylene intrinsic viscosity as a function of elution volume, as shown in equations (11) and (12):

[0147] MW PE =(K PS / KPE ) 1 / αPE+1 MW PS αPS+1 / αPE+1 (Equation 11)

[0148] [η] PE =K PS MW PS α+1 / MW PE (Equation 12).

[0149] The gpcBR branching index is a robust method for characterizing long-chain branching, as described in Yau, Wallace W., "Examples of Using 3D-GPC—TREF for Polyolefin Characterization," Macromol. Symp., 2007, 257, 29-45. This index avoids the "slice-by-slice" 3D-GPC calculations and branching frequency calculations traditionally used to determine g' values, in favor of the entire polymer detector area. From 3D-GPC data, the peak area method can be used to obtain the absolute weight average molecular weight (Mw(abs)) of the sample bulk using a light scattering (LS) detector. This method avoids the "slice-by-slice" ratio of the light scattering detector signal to the concentration detector signal required in traditional g' determinations.

[0150] In the case of 3D-GPC, the sample intrinsic viscosity can also be obtained independently using equation (13). This area calculation provides higher accuracy because, as the overall sample area, it is less sensitive to changes caused by detector noise and 3D-GPC settings for baseline and integration limits. More importantly, the peak area calculation is not affected by detector volume offset. Similarly, the sample intrinsic viscosity (IV) is obtained with high accuracy by the area method shown in equation (13):

[0151]

[0152] where η spi represents the specific viscosity obtained from the viscometer detector.

[0153] To determine the gpcBR branching index, the light scattering elution area of ​​the sample polymer is used to determine the molecular weight of the sample. The viscosity detector elution area of ​​the sample polymer is used to determine the intrinsic viscosity (IV or [η]) of the sample.

[0154] Initially, the molecular weight and intrinsic viscosity of a linear polyethylene standard sample such as SRM1475a or equivalent are determined using conventional calibration values ​​("cc") for both molecular weight and intrinsic viscosity as a function of elution volume according to equations (14) and (15):

[0155]

[0156] Equation (15) is used to determine the gpcBR branching index:

[0157]

[0158] where [η] is the measured intrinsic viscosity, [η] cc is the intrinsic viscosity from conventional calibration, Mw is the measured weight average molecular weight, and Mw ,cc is the conventionally calibrated weight average molecular weight. The weight average molecular weight determined by light scattering (LS) is often referred to as the "absolute weight average molecular weight" or "Mw, Abs." The Mw, cc according to equation (7) using a conventional GPC molecular weight calibration curve ("conventional calibration") is often referred to as the "polymer chain backbone molecular weight," "conventional weight average molecular weight," and "Mw(conv)."

[0159] All statistical values ​​with a "cc" subscript were determined using their respective elution volumes, corresponding conventional calibrations, and concentrations (Ci) as described previously. Non-subscripted values ​​are based on measurements of mass detector, LALLS, and viscometer areas. Iteratively adjusted K PE The values ​​of are calculated until the gpcBR measured for the linear reference sample is zero. For example, the final values ​​of α and Log K determined for gpcBR in this particular case were 0.725 and -3.391 for polyethylene and 0.722 and -3.993 for polystyrene, respectively. Once the K and α values ​​have been determined using the procedure discussed previously, the procedure is repeated using the branched sample. The branched sample is analyzed using the final Mark-Houwink constant obtained from the linear reference as the best "cc" calibration value. For linear polymers, the gpcBR calculated by equation (15) will be close to zero because the values ​​measured by LS and viscometry will be close to the conventional calibration standard. For branched polymers, the gpcBR will be above zero, especially for high levels of long chain branching because the measured polymer molecular weight will be higher than the calculated Mw,cc, and the calculated IVcc will be higher than the measured polymer IV. In effect, the gpcBR value represents the fractional IV change due to the molecular size shrinkage effect as a result of polymer branching. A gpcBR value of 0.5 or 2.0 implies a molecular size contraction effect of 50% and 200%, respectively, on the IV relative to an equivalent linear polymer molecule. For these specific examples, the advantage of using gpcBR over traditional "g' index" and branching frequency calculations is due to its higher precision. All parameters used in the gpcBR index determination are obtained with good precision and are not adversely affected by low 3D-GPC detector response at high molecular weights from the concentration detector. Errors in detector volume alignment also do not affect the accuracy of the gpcBR index determination.

[0160] LSP parameters

[0161] Representative values ​​of the GPC light scattering parameters (LSP) of Example 1 can be found in Tables 1 and 2 and Figure 5 Found in . The analysis of the material was performed in a manner similar to that of U.S. Patent No. 8,916,667B2 (Karjala et al.). The x-axis in the figure is the logarithmic value of the molecular weight calculated by conventional GPC, or cc-GPC molecular weight. The y-axis is the LS detector response. The specific characteristics of the LS elution curve are captured as defined by two logarithmic molecular weight limits. The lower limit corresponds to a MW1 value of 100,000 g / mol and the upper limit corresponds to a MW2 value of 900,00 g / mol. The vertical lines of these two molecular weight limits intersect the LS elution curve at two points. A line segment is drawn connecting the two intercepts. The height of the LS signal at the first intercept (log MW1) gives the LS1 quantity. The height of the LS signal at the second intercept (log MW2) gives the LS2 quantity. The area under the LS elution curve within the two molecular weight limits gives the area B quantity. Comparing the LS curve to the line segment connecting the two intercepts, a portion of the isolated area is above the line segment (see Figure 5 A2 in , which is defined as a negative value) or below the line segment (such as Figure 5 The sum of A1 and A2 gives the amount of area A, i.e., total area A. This total area A can be calculated as the difference between area B and the area under the line segment.

[0162] The steps of calculating the number of "LS" are shown using Example 1 shown in Tables 2 and 3.

[0163] Step 1: Calculate the slope F in Table 1 using the following equations 16-17:

[0164] Slope_Value = [(LS2-LS1) / LS2] / dLogMW (Equation 16)

[0165] Slope F = slope_function = abs(slope_value - 0.42) + 0.001 (Equation 17)

[0166] Step 2: Calculate "Area F" and "LSF" in Table 2 using the following equations 18-19:

[0167] Area F = Area Function = Abs(Abs(A / B)+0.033)-0.005) (Equation 18)

[0168] Where A / B = (Area A) / (Area B)

[0169] LSP = Log(Area F * Slope F) + 4 (Equation 19)

[0170] Table 2: "Slope F" calculation

[0171]

[0172] Table 3: Calculation of "Area F" and "LSP"

[0173]

[0174] Hexane extract

[0175] Polymer pellets (from a polymer pelletizing process without further modification; each 1 inch x 1 inch square of film is approximately 2.2 grams) were pressed in a Carver press at a thickness of 3.0 mils to 4.0 mils. The pellets were pressed at 8,000 psi for 3 minutes at 190°C, then cooled for 3 minutes, then pressed again at 40,000 psi for 3 minutes at 190°C, then cooled (12 minutes total). Residue-free gloves (PIP* CleanTeam* Cotton Lisle examination gloves, part number 97-501) were worn to prevent residual oil from the operator's hands from contaminating the membrane. Each membrane was trimmed into a 1 inch x 1 inch square and weighed (2.5 ± 0.05 g). The membranes were extracted in a heated water bath at 49.5 ± 0.5°C in a hexane container containing approximately 1000 ml of hexane for 2 hours. Hexane is an isomeric mixture of "hexanes" (e.g., hexane (Optima), Fisher Chemical, high purity mobile phase for HPLC and / or extraction solvent for GC applications). After two hours, the membrane is removed, rinsed in clean hexane, and dried in a vacuum oven (80±5°C) at full vacuum (ISOTEMP Vacuum Oven, Model 281A, at approximately 30 inches of mercury) for two hours. The membrane is then placed in a desiccator and allowed to cool to room temperature for at least one hour. The membrane is then reweighed, and the amount of mass loss due to extraction in hexane is calculated. This method is based on 21CRF 177.1520(d)(3)(ii), with one difference from the FDA protocol being that hexane is used instead of n-hexane; the average of 3 measurements is reported.

[0176] Slip additives

[0177] About 5 grams of sample were weighed (and recorded accurately to 0.0001-g) and placed in a 16-ounce glass bottle. A polytetrafluoroethylene (PTFE)-coated stirring rod was added to the bottle along with 120 mL of a 0.04% triethyl phosphite solution in o-xylene using a solvent dispenser. The bottle was loosely capped and placed on a heated stirrer and kept at 130°C with stirring for 30 minutes. After 30 minutes, the bottle was removed and the solution was cooled at room temperature while stirring for at least 2 hours. The polymer was further precipitated by adding 250 mL of methanol to the bottle using a solvent dispenser. The solution was stirred during this addition. The solution was stirred for an additional 2 hours. After stirring for 2 hours, the bottle was removed and the solid was allowed to settle. An aliquot of the solution was taken out with a glass pipette and transferred to a 2-mL glass autosampler vial. The vial was capped and placed on a gas chromatograph for analysis. Samples and standard solutions were analyzed using a gas chromatograph using pulsed splitless injection and a flame ionization detector. The concentration in the extract was determined using an external standard calibration procedure. Data for erucamide, oleamide, or stearamide in the resin are reported in parts per million (ppm; μg / g).

[0178] Antioxidants (AO)

[0179] Weigh approximately 5 grams of sample (and record accurately to 0.0001-g) and place it in a 4-ounce glass bottle. Use a solvent dispenser to add a PTFE-coated stirring rod along with 25 mL of a 0.04% triethyl phosphite solution in o-xylene to the bottle. The bottle is loosely capped and placed on a heated stirrer and kept under stirring at 130°C for 30 minutes. After 30 minutes, remove the bottle and cool the solution at room temperature while stirring for at least 2 hours. The polymer is further precipitated by adding 50 mL of methanol to the bottle using a solvent dispenser. The solution is stirred during this addition. The solution is stirred for an additional 2 hours. After stirring for 2 hours, remove the bottle and allow the solid to settle. Take an aliquot of the solution with a glass pipette and filter it into a 2 mL glass autosampler vial using a 0.2 μm PTFE (25 mm) syringe filter and a polypropylene syringe. The vial is capped and placed on a liquid chromatograph for analysis. Samples and standard solutions are analyzed using reversed-phase liquid chromatography using a UV / Vis absorbance detector. The concentration in the extract was determined using an external standard calibration procedure. Data for AO in the resin are reported in parts per million (ppm; μg / g). Further details can be found in Green, S.; Bai, S.; Cheatham, M.; Cong, R.; Yau, W., “Determination of Antioxidants in Polyolefins Using Total Dissolution Methodology Followed by RPLC”, Journal of Separation Science, 33(22), 3455–3462 (2010).

[0180] Anti-adhesion agent

[0181] Metal levels are determined by X-ray fluorescence using ASTM D6247. Talc or silica can be determined by elemental silicon (Si) or magnesium (Mg) by XRF. In laboratories that analyze many different types of materials, both Si and Mg can be measured. Talc results can be reported as calculated from Si or Mg, depending on the situation. For example, the level of talc can be calculated by measuring Mg and Si. It can also be calculated by measuring the residual ash %. If only Mg and Si are present (no other additives, etc.), the three measurements (XRF and residual ash %) should be consistent.

[0182] talc (Mg) =Talc (Si) =Talc (灰分) .

[0183] Talc can be determined by using both Mg and Si. If the two values ​​differ, further analysis may be required to determine the level of talc. For example, SiO2 will result in a higher value for talc when calculated using the XRF value of Si.

[0184] talc (Mg) <Talc (Si) .

[0185] This difference can be used to calculate the amount of SiO2.After determining the SiO2 level, a correction for the talc value can be calculated from the residual ash % measurement.

[0186] talc (灰分校正的) =Talc (灰分) -talc (SiO2) .

[0187] Additionally, if only SiO2 is present and Mg is absent, then elemental determination of talc by Mg can yield zero talc. Residual ash can be determined by ASTM D5630: Standard Test Method for Ash Content in Plastics.

[0188] mineral oil

[0189] Approximately 5 grams of sample were weighed (and recorded accurately to 0.0001-g) into a 4-ounce glass bottle, and then 20 mL of dichloromethane was added. The bottle was sealed with a PTFE-lined cap. The sample was extracted on a wrist shaker at room temperature for 24 hours. An aliquot of the extract was removed with a glass pipette and transferred to a 2 mL glass autosampler vial. The vial was capped and placed on a gas chromatograph for analysis. The samples and standard solutions were analyzed using gas chromatography with a flame ionization detector. A standard solution was prepared in dichloromethane using the same mineral oil reference material as that present in the resin. The mineral oil peak in the chromatogram was integrated. The oligomer and additive peak areas in the same retention time window as the mineral oil were subtracted from the mineral oil peak area. The concentration in the extract was determined using an external standard calibration procedure. The data for mineral oil in the resin were reported in parts per million (ppm; μg / g).

[0190] Example

[0191] Example 1 and Comparative Example 1: Preparation of Low Density Polyethylene

[0192] according to Figure 1As previously described, a mixture containing tert-butyl peroxy-2-ethylhexanoate (TBPO) and an isoparaffin solvent having a boiling range greater than 179°C was used as the initiator mixture for the first and second injection points. A mixture containing TBPO, tert-butyl peroxyacetate (TBPA), and an isoparaffin solvent was used as the initiator mixture for the third injection point. A mixture containing di-tert-butyl peroxide (DTBP), TBPA, TPBO, and an isoparaffin solvent was used for the fourth injection point. Table 4 shows the composition, in weight percent, of the peroxide initiator and solvent solutions used for each of the injection points.

[0193] Table 4

[0194]

[0195] Isobutane is used as a chain transfer agent. Isobutane is injected into the ethylene stream at the suction side of the booster / primary compressor. The composition of the CTA feed entering the process can be adjusted accordingly to maintain the desired melt index in the product.

[0196] The process conditions used to make the additive-free examples and comparative examples are given in Table 5. The reaction temperature of each autoclave zone and the lead-in tube was controlled by adjusting the peroxide flow rate to each of the reaction zones. The reactor pressure and reactor control temperature were used to ultimately control the molecular weight distribution of the product.

[0197] Table 5

[0198]

[0199]

[0200] The Examples and Comparative Examples were tested according to the test procedures disclosed herein to measure density, melt index (I2), melt strength, and hexane extractables. The results of density, melt index (I2), melt strength, and hexane extractables for Example 1 and Comparative Example 1 are shown in Table 6 below. Figure 6 , which graphically depicts the melt strength curves for Example 1 and Comparative Example 1, along with the melt strength plateau as depicted by the horizontal line of the average melt strength at high speeds near the end of the data (chain breakage).

[0201] Table 6

[0202]

[0203] Molecular weight data for various examples were measured according to the test procedures disclosed herein using both conventional (conv) and light scattering or absolute (abs) GPC methods, and the results are shown in Table 7 below.

[0204] Table 7

[0205]

[0206] The CDF and LSP data for various examples were measured according to the test procedures disclosed herein, and the results are shown in Table 8 below.

[0207] Table 8

[0208]

[0209] The viscosity data for each example was measured according to the test procedure disclosed herein, and the results are shown in Table 9 below.

[0210] Table 9

[0211]

[0212] The adoption of various embodiments 13 The branching data of number of branches / 1000 C measured by C NMR was measured according to the test procedure disclosed herein, and the results are shown in Table 10 below.

[0213] Table 10

[0214]

[0215] The comparative examples and examples 1 H NMR unsaturation data were measured according to the test procedures disclosed herein, and the results are shown in Table 11 below.

[0216] Table 11

[0217]

Claims

1. A low-density polyethylene homopolymer, comprising: A melt strength of greater than or equal to 6.4 cN and less than or equal to 8.5 cN measured at 190°C; Greater than or equal to 0.9210g / cm 3 and less than or equal to 0.9275g / cm 3 density; a melt index I2 greater than, or equal to, 4.5 g / 10 min and less than, or equal to, 7.5 g / 10 min, measured at 190°C; and Molecular weight distribution (Mw(conv) / Mn(conv)) greater than or equal to 7.3 and less than or equal to 9.5, wherein the low density polyethylene homopolymer comprises a GPC light scattering parameter (LSP) greater than 2.5 and less than 3.

8.

2. The low-density polyethylene homopolymer according to claim 1, wherein the melt index I2 measured at 190°C is greater than or equal to 4.5 g / 10 min and less than or equal to 6.5 g / 10 min. 3 . The low-density polyethylene homopolymer according to claim 1 , wherein the melt strength measured at 190° C. is greater than or equal to 6.4 cN and less than or equal to 7.0 cN.

4. The low density polyethylene homopolymer according to any one of claims 1 to 3, wherein the density is greater than or equal to 0.9220 g / cm 3 and less than or equal to 0.9265g / cm 3 .

5. The low density polyethylene homopolymer according to any one of claims 1 to 3, wherein the hexane extractables level is less than or equal to 2.60%.

6. The low density polyethylene homopolymer of any one of claims 1 to 3, wherein the low density polyethylene homopolymer comprises a z-average molecular weight Mz(conv) greater than 500,000 g / mol.

7. The low density polyethylene homopolymer of any one of claims 1 to 3, wherein the low density polyethylene homopolymer comprises a z-average molecular weight, Mz(conv), greater than, or equal to, 530,000 g / mol and less than, or equal to, 620,000 g / mol.

8. A film comprising the low-density polyethylene homopolymer according to any one of claims 1 to 7.

9. A film comprising a mixture of linear low density polyethylene (LLDPE) and the low density polyethylene homopolymer according to any one of claims 1 to 7.

10. A cast film, blown film or thermoformed film comprising the low density polyethylene homopolymer according to any one of claims 1 to 7.

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