Ethylene polymer compositions with multifunctional branching agents and their production methods

Abstract

The present disclosure provides a method. In one embodiment, the method comprises providing a multifunctional branching agent (MFBA). The MFBA has A) three or more carbon-carbon double bonds, provided that (1) the MFBA is not a polymer of butadiene, and (2) the MFBA does not contain acrylate groups or methacrylate groups. The MFBA has B) a total reactivity R greater than 3 and less than 40 (3 < R < 40), where R is determined according to the following formula (I): where j = summation index, p = the number of different types of carbon-carbon double bonds j in the molecule, n j = the number of each type j of carbon-carbon double bond in the molecule, and r 1,j = the relative reactivity ratio (RRR) of ethylene to carbon-carbon double bond j. The method comprises reacting the MFBA with ethylene under polymerization conditions and forming an ethylenic polymer composition comprising ethylene units and MFBA units. The present disclosure also provides an ethylenic polymer composition obtained by the method. Formula (I)

Description

Background Art

[0001] The level of branching in vinyl polymers such as, for example, low density polyethylene (LDPE) is mainly attributed to the reactor design (autoclave or tubular) and the polymerization conditions used to prepare LDPE. The level of branching is also directly related to the melt strength of the final polymer. Branching agents are known for increasing the level of branching in LDPE. However, the process conditions required to achieve modified LDPE with a high level of branching typically result in a final product with lower crystallinity and a higher content of low molecular weight extractable fractions.

[0002] Thus, there is a continuing recognition in the art for LDPE having increased melt strength relative to an increased level of branching, which is prepared under polymerization conditions that maintain good polymer properties. Summary of the Invention

[0003] The present disclosure provides a method. In one embodiment, the method includes providing a multifunctional branching agent (MFBA). The MFBA has A) three or more carbon-carbon double bonds, provided that (1) the MFBA is not a polymer of butadiene, and (2) the MFBA does not contain acrylate or methacrylate groups. The MFBA has B) a total reactivity R greater than 3 and less than 40 (3 < R < 40), where R is determined according to Equation (I):

[0004] Equation (I)

[0005]

[0006] where

[0007] j = summation index,

[0008] p = the number of different types of carbon-carbon double bonds j in the molecule,

[0009] n j = the number of each j-type carbon-carbon double bond in the molecule, and

[0010] r 1,j = the relative reactivity ratio (RRR) of ethylene to carbon-carbon double bond j. The method includes reacting the MFBA with ethylene under polymerization conditions and forming a vinyl polymer composition comprising ethylene units and MFBA units.

[0011] The present disclosure also provides an ethylenic polymer composition obtained by the method. In one embodiment, the ethylenic polymer composition comprises (i) ethylene units; and (ii) multifunctional branching agent (MFBA) units. The MFBA has (A) three or more carbon-carbon double bonds, provided that (1) the MFBA is not a polymer of butadiene, and (2) the MFBA does not contain acrylate groups or methacrylate groups. The MFBA has (B) a total reactivity R greater than 3 and less than 40 (3 < R < 40), where R is determined according to formula (I) Formula (I)

[0012]

[0013] where

[0014] j = summation index,

[0015] p = the number of different types of carbon-carbon double bonds in the MFBA,

[0016] n j = the number of each type j of carbon-carbon double bonds in the molecule, and

[0017] r 1,j = the relative reactivity ratio (RRR) of ethylene to carbon-carbon double bond j. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shows the chemical structure of a multifunctional branching agent according to one embodiment of the present disclosure.

[0019] Figure 2 Shows the chemical structure of a multifunctional branching agent according to one embodiment of the present disclosure.

[0020] definition

[0021] Any reference to the Periodic Table of the Elements is to the Periodic Table published by CRC Press, Inc. in 1990 - 1991. A group of elements in the table is referred to by the new notation used to number the groups.

[0022] For the purposes of United States patent practice, the content of any patent, patent application, or publication referred to, particularly with respect to the disclosure of definitions (to the extent that it is not inconsistent with any definition specifically provided in the present disclosure) and general knowledge in the art, is incorporated by reference in its entirety (or its equivalent United States version is also incorporated by reference in this manner).

[0023] The numerical ranges disclosed herein include all values ​​from the lower limit to the upper limit, and include both the lower limit and the upper limit. For a range containing an exact value (e.g., 1 or 2, or 3 to 5, or 6, or 7), any subrange between any two exact values ​​is included (e.g., the range 1 to 7 above includes subranges 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6, etc.).

[0024] Unless stated to the contrary, implied by the context, or as is customary in the art, all parts and percentages are based on weight, and all test methods are current methods as of the date of this disclosure.

[0025] "Alkanes" are saturated hydrocarbons. "Alkyl groups" are alkane with a certain valence (usually a single valence).

[0026] An "olefin" is a hydrocarbon containing a carbon-carbon double bond. An "alkenyl group" is an olefin with a certain valence (usually a monovalent valence).

[0027] The term "allyl" (or "allyl group") refers to a monovalent unsaturated C3H5 hydrocarbon. In other words, allyl is propylene minus one hydrogen atom.

[0028] As used herein, the term "blend" or "polymer blend" refers to a mixture of two or more polymers. Blends may be miscible or immiscible (not phase-separated at the molecular level). Blends may or may not be phase-separated. Blends may or may not contain one or more structural domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and other methods known in the art. Blends can be achieved by physically mixing two or more polymers at a macroscopic level (e.g., melt-blending or compounding) or a microscopic level (e.g., simultaneous formation within the same reactor).

[0029] The term "composition" refers to a mixture of materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0030] 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 they are specifically disclosed. For the avoidance of any doubt, unless stated otherwise, all compositions claimed using the term “comprising” may include any additional additives, adjuvants, or compounds, whether polymerized or otherwise. Conversely, the term “consisting of” excludes any other components, steps, or procedures from any subsequently listed scope, except those not essential for operability. The term “consisting of” excludes any components, steps, or procedures not specifically stated or listed. Unless otherwise stated, the term “or” refers to members listed individually and in any combination. Use of the singular includes use of the plural, and vice versa.

[0031] As used herein, the term "ethylene polymer composition" refers to a composition comprising, in polymeric form, more than 50 wt% or the majority amount of ethylene, and optionally may include at least one comonomer or other molecule.

[0032] As used herein, the term "ethylene monomer" refers to a chemical unit having two carbon atoms with a double bond therebetween, and each carbon atom being bonded to two hydrogen atoms, wherein said chemical unit is polymerized with other such chemical units to form an ethylene-based polymer composition. A "hydrocarbon" is a compound containing only hydrogen and carbon atoms. A "hydrocarbon group" (or "hydrocarbon group") is a hydrocarbon having a valence (usually a monovalence). Hydrocarbons can have straight-chain, cyclic, or branched structures.

[0033] As used herein, the term "low-density polyethylene" (or LDPE) refers to polyethylene having a density of 0.910 g / cc to less than 0.940 g / cc or 0.918 g / cc to 0.930 g / cc and long chain branches having a wide molecular weight distribution (MWD) (i.e., "wide MWD" is 4.0 to 20.0).

[0034] "Alkenes" are unsaturated aliphatic hydrocarbons with carbon-carbon double bonds.

[0035] The term "phenyl" (or "phenyl group") refers to a C6H5 aromatic hydrocarbon ring with a certain valence (usually monovalence).

[0036] As used herein, the term "polymer" or "polymeric material" refers to a compound prepared by polymerizing monomers, whether of the same or different types, which, in polymeric form, provide multiple and / or repeating "units" or "monomer units" constituting the polymer. Therefore, the general term polymer encompasses the term homopolymer, which is generally used to refer to polymers prepared from only one type of monomer, and the term copolymer, which is generally used to refer to polymers prepared from at least two types of monomers. The general term polymer also encompasses all forms of copolymers, such as random copolymers, block copolymers, etc. The terms "ethylene / α-olefin polymer" and "propylene / α-olefin polymer" indicate copolymers prepared, as described above, by polymerizing ethylene or propylene and one or more other polymerizable α-olefin monomers, respectively. It should be noted that although polymers are often referred to as being "made" from one or more specific monomers, "based on" a specific monomer or monomer type, "containing" a specific monomer content, etc., in this context, the term "monomer" should be understood as referring to the polymeric remnant of a specific monomer, not an unpolymerized species. Generally, the term polymer herein refers to a "unit" based on the corresponding monomer in polymeric form.

[0037] Test methods

[0038] Density was measured according to ASTM D792 Method B. Results were reported in grams per cubic centimeter (g / cc).

[0039] Melt index

[0040] As used herein, the term "melt index" (or "MI" or "I2") refers to a measure of how easily a thermoplastic polymer flows when in a molten state. Melt index, or I2, is measured at 190°C / 2.16 kg according to ASTM D1238 and reported in grams eluted per 10 minutes (g / 10min). I2 is measured at 190°C / 10 kg according to ASTM D1238. 10 And report the amount eluted per 10 minutes (g / 10min). According to ASTM D1238, the melt index ratio (I) is measured at 190°C. 10 / I2), taking the ratio of the values ​​obtained at 10kg and 2.16kg.

[0041] melt strength

[0042] As used herein, the term "melt strength" refers to a measure of the maximum tensile force applied to a polymer in its molten state before it fractures. Melt strength is used at 190°C. Rheotens 71.97 (Rockhill, South Carolina) company( Inc.; Rock Hill, SC)) and measured with a Rheotester 2000 capillary rheometer with a flat angle of incidence (180 degrees), a length of 30 mm and a diameter of 2 mm Feed the melted sample (25 to 50 grams) after melting the sample. Feed the sample into the barrel (L = 300 mm, diameter = 12 mm), compress and melt it for 10 minutes, and then extrude it at a constant piston speed of 0.265 mm / s, which corresponds to 38.2 s -1 of the wall shear rate. The extrudate passes through the wheel of the Rheotens located 100 mm below the die exit and is pulled downward by the wheel with an acceleration of 2.4 millimeters per square second (mm / s 2 ). Record the force applied to the wheel (in centinewtons, cN) as a function of the speed of the wheel (in mm / s). Repeat the sample at least twice until two curves of the force (in cN) as a function of the strand speed (in mm / s) overlap, and then report the curve with the highest speed at strand breakage. Report the melt strength as the plateau force before strand breakage, in centinewtons, cN. Detailed Description

[0043] 1. Method

[0044] The present disclosure provides a method. The method includes providing a multifunctional branching agent (MFBA) and reacting the MFBA with ethylene under polymerization conditions. The method includes forming an ethylene-based polymer composition comprising ethylene units and MFBA units. The method includes providing or otherwise selecting a multifunctional branching agent (or "MFBA"). As used herein, "multifunctional branching agent" is a compound that meets or otherwise achieves the following parameters (A) and (B):

[0045] A) Three or more carbon-carbon double bonds, provided that

[0046] (1) The MFBA is not a polymer of butadiene, and

[0047] (2) The MFBA does not contain acrylate or methacrylate groups,

[0048] B) The total reactivity R is greater than 3 and less than 40, (3 < R < 40), where R is determined according to Equation (I) Equation (I)

[0049]

[0050] where

[0051] j is the summation index,

[0052] p represents the number of different types of carbon-carbon double bonds in MFBA.

[0053] n j It is the number of each J-type carbon-carbon double bond in the molecule, and

[0054] r 1,j It is the relative reactivity ratio (RRR) of ethylene with respect to free radical growth of carbon-carbon double bond j. In the context of equation (I), it should be understood that "is" is interchangeable with the equal sign "=".

[0055] The method includes providing or otherwise selecting MFBA having (A) three or more carbon-carbon double bonds, provided that (1) the MFBA is not a polymer of butadiene and (2) the MFBA does not contain acrylate or methacrylate groups. As used herein, a “carbon-carbon double bond” has the structure (I):

[0056] Structure (I)

[0057] C = C

[0058] The MFBA has three or more carbon-carbon double bonds, or 3, 5, 10 to 20, 30, 50, or 100 or more carbon-carbon double bonds. In one embodiment, the MFBA has 3 to 100 carbon-carbon double bonds, or 5 to 50 carbon-carbon double bonds, or 10 to 30 carbon-carbon double bonds.

[0059] As used herein, “polymers of butadiene” refers to polymers having polymeric C4H6 units of structure (II):

[0060] Structure (II)

[0061]

[0062] and / or polymers having structure (III):

[0063] Structure (III)

[0064]

[0065] Where m is an integer from 1 to 100, and n is an integer from 0 to 100. This MFBA does not contain or otherwise excludes "polymers of butadiene".

[0066] As used herein, "acrylate group or methacrylate group" refers to a reactive group containing the following structure (IV):

[0067] Structure (IV)

[0068]

[0069] Where R1 is H or CH3. Structure (IV) contains acrylates and methacrylates. This MFBA does not or otherwise exclude "acrylate groups or methacrylate groups".

[0070] In addition to satisfying the above (A), the multifunctional branching agent satisfies or otherwise satisfies a total reactivity R where 3 < R < 40, where R is determined according to Equation (I) Equation (I)

[0071]

[0072] Where

[0073] j = summation index,

[0074] p = the number of different types of carbon-carbon double bonds in the MFBA,

[0075] n j = the number of each type j of carbon-carbon double bond in the molecule, and

[0076] r 1,j = the relative reactivity ratio (RRR) of ethylene to free radical polymerization of the carbon-carbon double bond j.

[0077] The term "j" is the summation index (or the lower limit of the summation, the number used to generate the first term in the sequence). The term "p" is the number of different types of C-C double bonds (carbon-carbon double bonds) present in the MFBA. Figure 1 Shows the structure of the MFBA represented by reference numeral 10, i.e., diallyl maleate. Diallyl maleate (10) has two different types of C-C double bonds. The first C-C double bond is shown by reference numeral 12. The second type of C-C double bond, the terminal double bond, is shown by reference numerals 14a and 14b. Although diallyl maleate has a total of three C-C double bonds, the number of different types of bonds is 2 because the two terminal C-C bonds (reference numerals 14a, 14b) are the same type of C-C double bond, i.e., the terminal C-C double bond. For diallyl maleate, the value of "p" is 2.

[0078] Figure 2 Shows another non-limiting example of an MFBA, 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane (hereinafter interchangeably referred to as "(D Vi )4") and represented by reference numeral 20. (D Vi )4 (reference numeral 20) has four C-C double bonds 22a, 22b, 22c, and 22d. The C-C double bonds 22a, 22b, 22c, and 22d are each the same type of C-C double bond. Thus, for (D Vi )4, p = 1.

[0079] In formula (I), the term "n" represents the number of each type of double bond. For example, diallyl maleate ( Figure 1 The reference numeral 10 shown in the figure has one CC double bond 12 for the first CC double bond type and two terminal CC double bonds 14a, 14b for the second CC double bond type. As a further example, (D Vi )4( Figure 2 The figure in Figure 20) has four identical C-C double bonds 22a, 22b, 22c and 22d.

[0080] The reactivity ratio is calculated as the relative reactivity of ethylene to the C / C double bond under discussion. The reactivity ratio can be experimentally measured by running experiments. Alternatively, the reactivity ratio can be calculated according to quantum mechanics, or can be found in the following reference: Mortimer and Ehrlich, Fundamentals of the Free-Radical Polymerization of Ethylene, Adv. Polymer Sci, Vol. 7, pp. 386-448 (1970) (hereinafter referred to interchangeably as Mortimer), the contents of which are incorporated herein by reference. Table 1 below provides non-limiting examples of the reactivity ratios (relative to ethylene) of several reactive groups determined by Mortimer.

[0081] Non-limiting examples of reactive groups and corresponding reactivity ratios are provided in Table 1 below.

[0082] Table 1*

[0083]

[0084]

[0085] *See Mortimer

[0086] Table 2 below provides non-limiting examples of suitable multifunctional branching agents and calculates R, the total reactivity, using formula (I). Polymer formulas are simplified to their respective repeating units.

[0087] Table 2

[0088]

[0089] Table 3 below shows non-limiting examples of compounds that do not meet parameters (A) and (B) and are not “multifunctional branching agents” according to this disclosure. This is mainly because R is less than 3 or R is greater than 40 and / or the total number of C-C double bonds in the molecule is less than 3, or because one or more C-C double bonds are acrylates or methacrylates.

[0090] Table 3 - Compounds that are not MFBA

[0091]

[0092] This method involves reacting MFBA with ethylene under polymerization conditions. As used herein, the term "polymerization conditions" includes free radical-initiated polymerization in a polymerization reactor at high pressure (11,000 psig to 53,000 psig) and high temperature (200°C to 350°C).

[0093] In one implementation scheme, MFBA is selected from (D Vi 4. Diallyl maleate, polyisoprene, polymyrrhene, polyfarnesene, and combinations thereof.

[0094] In one implementation scheme, MFBA is (D Vi 4.

[0095] In one implementation, MFBA is diallyl maleate.

[0096] The reaction of MFBA and ethylene under polymerization conditions forms an ethylene-based polymer having units derived from ethylene and units derived from MFBA, wherein the ethylene units constitute the majority (wt%) of the monomers present in the polymer. In other words, the ethylene-based polymer comprises ethylene monomers and MFBA comonomers, with ethylene and MFBA each polymerized into the polymer backbone. In this way, this ethylene-based polymer is structurally different from polyethylene having functional auxiliaries grafted onto the polymer chain as side chains.

[0097] The polymerization conditions involve polymerization using one, two, or more free radical indicators. Non-limiting examples of suitable free radical initiators include organic peroxides, cyclic peroxides, diacid peroxides, dialkyl peroxides, hydroperoxides, peroxycarbonates, peroxydicarbonates, peroxyesters, peroxyketals, tert-butyl peroxypentanoate, di-tert-butyl peroxide, tert-butyl peroxyacetate, tert-butyl perethylhexanoate, and tert-butyl peroxy-2-hexanoate, as well as combinations thereof. In one embodiment, these organic peroxy initiators are used in amounts from 0.001 wt% to 0.2 wt% based on the weight of the polymerizable monomer.

[0098] In a further embodiment, the radical initiator comprises at least one peroxide group incorporated in the ring structure. Examples of such initiators include, but are not limited to, TRIGONOX 301 (3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane) and TRIGONOX 311 (3,3,5,7,7-pentamethyl-1,2,4-trioxacycloheptane), available from Akzo Nobel, and HMCH-4-AL (3,3,6,6,9,9-hexamethyl-1,2,4,5-tetraoxacyclononane), available from United Initiators.

[0099] For polymerization conditions, the polymerization reactor includes reactor configurations comprising tubular reactors and / or autoclave reactors and / or continuous stirred tank reactors.

[0100] In one embodiment, polymerization occurs in a reactor configuration that includes at least one tubular reactor.

[0101] In one embodiment, polymerization occurs in a reactor configuration that includes at least one autoclave reactor.

[0102] In one embodiment, the method includes reacting ethylene with MFBA in an amount from 5 mol ppm to 2000 mol ppm based on the amount of ethylene added to the polymerizer, and forming an ethylene-MFBA copolymer with a melt strength 10% to 200% greater than that of the baseline ethylene homopolymer. As used herein, the term "mol ppm" means one mole of ethylene to 1 x 10⁻⁶ ppm. -6 The relationship between molar MFBA. As used herein, “baseline ethylene homopolymer” is an ethylene homopolymer prepared under the same polymerization conditions as those used to produce the ethylene-MFBA copolymer, and has the same or substantially the same melt index (I2 ± 0.5 g / 10 min) as the ethylene-MFBA copolymer.

[0103] In one embodiment, a conventional chain transfer agent (CTA) is used to control the molecular weight. One or more CTAs are added to the polymerization process. Non-limiting examples of suitable CTAs include propylene, isobutane, n-butane, 1-butene, methyl ethyl ketone, acetone, ethyl acetate, propionaldehyde, ISOPAR (ExxonMobil Chemical Co.), methanol, and isopropanol. In one embodiment, the amount of CTA used in the process is from 0.03% to 10% by weight of the total reaction mixture.

[0104] In one implementation, the method includes a process loop to improve conversion efficiency.

[0105] In one embodiment, polymerization occurs in a tubular reactor. The tubular reactor can be a single-zone tubular reactor or a multi-zone tubular reactor. In a further embodiment, the tubular reactor is a multi-zone tubular reactor. The multi-zone tubular reactor includes alternating sites for feeding fresh olefins to control the ethylene to CTA ratio, thereby controlling polymer properties. Fresh ethylene monomer is added simultaneously at multiple sites to achieve a desired ethylene monomer to chain transfer ratio. Similarly, the addition of fresh CTA is selected at multiple sites to control polymer properties. Fresh CTA is added simultaneously at multiple sites to achieve a desired CTA to ethylene monomer ratio. Likewise, the addition sites and the amount of fresh MFBA are controlled to control gel formation while maximizing increased melt strength and desired properties in the target application. Fresh MFBA can be added simultaneously at multiple sites to achieve a desired branching agent to ethylene monomer ratio. Using MFBA to broaden the molecular weight distribution and increase the melt strength of the polymer will place further demands on the distribution of CTA and MFBA along the reaction system to achieve the desired changes in product properties without potential negative impacts (such as gel formation, reactor fouling, process instability) or to minimize potential negative impacts and the amount of MFBA. Non-limiting examples of suitable multi-zone tubular reactors are described in WO2013059042 and WO2013078018, the contents of which are incorporated herein by reference.

[0106] In one embodiment, polymerization occurs in a multi-reactor system, where an autoclave reactor precedes a tubular reactor. The addition points and amounts of fresh ethylene, fresh CTA, and fresh MFBA are controlled to achieve the desired ratios of CTA to ethylene monomer and MFBA to ethylene monomer in the feed leading to the reaction zone and / or in the reaction zone.

[0107] In one embodiment, MFBA is fed directly into the reaction zone via a compression stage or directly into the feed leading to the reaction zone. The selection of the feed point for the reaction and / or reaction zone depends on several factors, including, but not limited to, the solubility of MFBA in pressurized ethylene and / or solvents, the condensation of MFBA in pressurized ethylene, and / or scaling caused by premature polymerization of MFBA in the preheater used to heat the reactor contents before the initiator is injected.

[0108] In one implementation, MFBA is fed directly into the reaction zone or directly into the feed leading to the reaction zone.

[0109] In one implementation, MFBA is fed only into reaction zone 1.

[0110] In one embodiment, the ethylene fed into the first reaction zone is 10% to 100% of the total ethylene fed into the polymerization. In a further embodiment, the ethylene fed into the first reaction zone is 20% to 80% (further, 25% to 75%, further, 30% to 70%, further, 40% to 60%) of the total ethylene fed into the polymerization.

[0111] In one embodiment, the method occurs in a reactor configuration comprising at least one tubular reactor. In a further embodiment, the maximum temperature in each reaction zone is 200°C to 350°C, further, 220°C to 325°C, and further, 225°C to 300°C.

[0112] In one embodiment, the polymerization pressure at the first inlet of the reactor is 800 bar to 3600 bar, or 1500 bar to 3400 bar, or 2000 bar to 3200 bar.

[0113] In one implementation, the ratio of "the concentration of CTA in the feed leading to reaction zone i" to "the concentration of CTA in the feed added to reaction zone 1" is greater than or equal to 1.

[0114] In one implementation, the ratio of "the concentration of CTA in the feed leading to reaction zone i" to "the concentration of CTA in the feed added to reaction zone 1" is less than 1, or less than 0.8, or less than 0.6, or less than 0.4.

[0115] In one implementation, the number of reaction zones is 3-6.

[0116] Non-limiting examples of ethylene monomers used for the production of ethylene-based polymers include purified ethylene, obtained by removing polar components from the loop recirculation stream or by constructing a reaction system such that only fresh ethylene is used to prepare the ethylene-based polymers of the present invention. Further examples of ethylene monomers include ethylene monomers from the recirculation loop.

[0117] In one embodiment, the method includes reacting a ternary comonomer with ethylene and MFBA under polymerization conditions. The method includes forming an ethylene-based polymer composition comprising ethylene monomer units, MFBA units, and one or more ternary comonomer units. Non-limiting examples of suitable ternary comonomers include α-olefins, acrylates, methacrylates, vinyl acetate, vinyltrimethoxysilanes, and acid anhydrides, each having no more than 20 carbon atoms. The α-olefin ternary comonomer may have 3 to 10 carbon atoms, or alternatively, it may have 3 to 8 carbon atoms or 4 to 8 carbon atoms. Exemplary α-olefin ternary comonomers include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-1-pentene.

[0118] In one embodiment, the method comprises reacting ethylene, MFBA (and optionally a terpolymer monomer) under polymerization conditions in the presence of one or more optional additives to form an ethylene-based polymer composition. Non-limiting examples of suitable additives include stabilizers, plasticizers, antistatic agents, pigments, dyes, nucleating agents, fillers, slip agents, flame retardants, processing aids, smoke suppressants, viscosity control agents, and anti-caking agents. Based on the weight of the composition, the composition may, for example, contain 0 wt% or more but less than 30% of one or more additives by weight. Compositions having MFBA copolymerized with ethylene and one or more optional additives are interchangeably referred to below as "MFBA(PE)".

[0119] In one embodiment, MFBA (PE) is treated with one or more stabilizers, such as IRGANOX 1010, IRGANOX 1076, and IRGANOX 168.

[0120] 2. Polymer

[0121] This disclosure provides an ethylene-based polymer (interchangeably referred to as "MFBA(PE)") composed of ethylene units and MFBA units. MFBA(PE) is formed by reacting MFBA with ethylene (and optionally a ternary comonomer) under the polymerization conditions disclosed above. MFBA(PE) comprises ethylene units; (optionally, ternary comonomer units) and multifunctional branching agent (MFBA) units, which have…

[0122] (A) Three or more carbon-carbon double bonds, provided that

[0123] (1) MFBA is not a polymer of butadiene, and

[0124] (2) MFBA does not contain acrylate groups or methacrylate groups.

[0125] (B) A total reactivity R greater than 3 and less than 40 (3 < R < 40), where R is determined according to the following formula (I)

[0126] Determine

[0127] Formula (I)

[0128]

[0129] Where

[0130] j = summation index,

[0131] p = the number of different types of carbon-carbon double bonds in MFBA,

[0132] n j = the number of each type j of carbon-carbon double bonds in the molecule, and

[0133] r 1,j = the relative reactivity ratio (RRR) of ethylene to carbon-carbon double bond j.

[0134] Without being limited by any particular theory, MFBA increases the melt strength of the resonance peak vinyl polymer composition. Under polymerization conditions, one, or two, or three, or more carbon-carbon double bonds in MFBA react (bond) with the growing chain forming the vinyl polymer to become part of the polyethylene chain. The vinyl polymer has units derived from ethylene and units derived from MFBA, where the units derived from ethylene constitute the majority (wt%) of the units present in the polymer. In other words, the vinyl polymer contains ethylene monomer and MFBA comonomer, and ethylene and MFBA are each polymerized into the polymer backbone. In this way, the present vinyl polymer is structurally different from polyethylene having a functional aid grafted to the polymer chain in a side-chain manner. The ethylene-MFBA copolymer composition may be interchangeably referred to as "MFBA(PE)".

[0135] In one embodiment, MFBA is selected from (D Vi ) 4, diallyl maleate, polyisoprene, polylaurene, polyfarnesene, and combinations thereof.

[0136] In one embodiment, MFBA is (D Vi ) 4.

[0137] In one embodiment, MFBA is diallyl maleate.

[0138] In one embodiment, the MFBA (PE) comprises 95 wt%, or 96 wt%, or 97 wt%, or 98 wt% to 99 wt%, or 99.5 wt%, or 99.8 wt%, or 99.9 wt%, or 99.95 wt% or 99.99 wt% of ethylene in polymeric form, and the reverse amount of MFBA, or 5.0 wt%, or 4.0 wt%, or 3.0 wt%, or 2.0 wt% to 1.0 wt%, or 0.5 wt%, or 0.2 wt%, or 0.1 wt%, or 0.05 wt% or 0.01 wt% of MFBA. The weight percentages are based on the total weight of the MFBA (PE). In a further embodiment, the MFBA (PE) comprises 95 wt% to 99.99 wt%, or 96 wt% to 99.95 wt%, or 97 wt% to 99.9 wt%, or 98 wt% to 99.8 wt% of ethylene in polymeric form, and the MFBA is present in an amount of 5.0 wt% to 0.01 wt%, or 4.0 wt% to 0.05 wt%, or 3.0 wt% to 0.1 wt%, or 2.0 wt% to 0.2 wt%.

[0139] In one embodiment, MFBA(PE) has a density of 0.915 g / cc to 0.935 g / cc.

[0140] In one embodiment, the MFBA (PE) has a melt index (I2) of 0.05 g / 10 min, or 0.5 g / 10 min, or 1.0 g / 10 min, or 5.0 g / 10 min, or 10 g / 10 min, or 20 g / 10 min, or 30 g / 10 min, or 40 g / 10 min to 50 g / 10 min, or 60 g / 10 min, or 70 g / 10 min, or 100 g / 10 min or 1000 g / 10 min. In a further embodiment, the MFBA (PE) has a melt index (I2) of 0.15 g / 10 min to 80 g / 10 min, or 0.5 g / 10 min to 70 g / 10 min, or 1.0 g / 10 min to 60 g / 10 min, or 5.0 g / 10 min to 50 g / 10 min, or 10 g / 10 min to 40 g / 10 min, or 20 g / 10 min to 30 g / 10 min. In yet another embodiment, the MFBA (PE) has a melt index of 0.1 g / 10 min to 4.5 g / 10 min, or 0.5 g / 10 min to 4.0 g / 10 min.

[0141] In one embodiment, the ethylene polymer composition comprises an ethylene monomer, MFBA, and one or more terpolymeric copolymers. Non-limiting examples of terpolymeric copolymers include α-olefins, acrylates, methacrylates, acrylic acid, methacrylic acid, vinyl acetate, vinyltrimethoxysilane, and acid anhydrides, each having no more than 20 carbon atoms. The α-olefin terpolymeric copolymer may have 3 to 10 carbon atoms, or alternatively, it may have 3 to 8 carbon atoms or 4 to 8 carbon atoms. Exemplary α-olefin terpolymeric copolymers include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and 4-methyl-1-pentene.

[0142] In one embodiment, the vinyl polymer composition comprises one or more optional additives. Non-limiting examples of suitable additives include stabilizers, plasticizers, antistatic agents, pigments, dyes, nucleating agents, fillers, slip agents, flame retardants, processing aids, smoke suppressants, viscosity control agents, and anti-caking agents. Based on the weight of the vinyl polymer composition, the vinyl polymer composition may, for example, contain 0 wt% or more to less than 10 wt% of one or more additives by combined weight.

[0143] In one embodiment, MFBA (PE) is treated with one or more stabilizers, such as IRGANOX 1010, IRGANOX 1076, and IRGANOX 168.

[0144] An MFBA (PE) may comprise a combination of two or more implementations as described herein.

[0145] This disclosure also provides an article comprising at least one component formed from the MFBA (PE) described herein.

[0146] In one embodiment, the article is a coating of a film.

[0147] In one embodiment, the article is a coating.

[0148] In one embodiment, the article is a membrane.

[0149] The article may comprise a combination of two or more embodiments as described herein.

[0150] 3. Application

[0151] The MFBA (PE) disclosed herein can be used in a variety of conventional thermoplastic manufacturing processes to produce useful articles, including single-layer and multi-layer films; molded articles, such as blow-molded articles, injection-molded articles, or rotationally molded articles; coatings; fibers; and woven or nonwoven fabrics.

[0152] This MFBA (PE) can be used in a variety of films, including but not limited to clean shrink film, bundled shrink film, cast stretch film, silage film, stretch covers, sealants, and diaper backing. Other suitable applications include, but are not limited to, wires and cables, gaskets and profiles, adhesives, footwear components, and automotive interior parts.

[0153] The applicant found that adding MFBA during ethylene polymerization resulted in an increase in the melt strength of LDPE at the same MI compared to LDPE prepared under the same polymerization conditions without the addition of MFBA.

[0154] Some embodiments of this disclosure will now be described in detail by way of examples rather than limitation, in the following examples.

[0155] Example

[0156] The materials used in the embodiments are described in Table 4 below.

[0157] Table 4

[0158]

[0159] Example 1: Diallyl maleate (BAIIM) as a multifunctional branching agent

[0160] Polymerization is carried out in a continuous stirred tank reactor. The reactor is heated and / or cooled to 220°C using four electric heating bands. The reactor pressure is approximately 2000 bar. A certain amount of propylene is used as a chain transfer agent (CTA) to control the final polymer melt index (MI) at 4.0. Ethylene and propylene are fed to the top of the reactor via a stirring shaft. TPO and TPA, diluted in Isopar E, are injected into one side of the reactor to initiate the reaction, thereby maintaining the total ethylene conversion at ~12%. Diallyl maleate, also diluted in Isopar E, is fed into a separate injector located on one side of the reactor. The reactor residence time is approximately 1.5 minutes. A single outlet on the bottom of the reactor contains all unreacted reactants and polymer. The polymer is separated from the remaining reactants by atomization, the feed stream is depressurized to approximately 1 bar, and simultaneously cooled to ambient temperature. The polymer is then collected in powder form.

[0161] The structure of diallyl maleate is as follows: Figure 1As shown in Figure 10. Diallyl maleate contains three C-C double bonds, contains no acrylate or methacrylate groups, and is not a product of butadiene polymerization, thus satisfying parameter (A) of MFBA. Diallyl maleate contains two different types of C-C double bonds (p=2). Diallyl maleate has one internal maleate double bond n1=1 with a reactivity ratio of 0.2. Diallyl maleate has two terminal vinyl groups n2=2 with a reactivity ratio of 3.1. Therefore, the R value is calculated to be 5.6. Thus, diallyl maleate satisfies parameters (A) and (B) (Equation 1) and is therefore an MFBA as defined herein.

[0162] Data from embodiments of the invention using diallyl maleate (BAIIM) as the MFBA are shown in Table 5. The addition of 30 mol ppm to 93 mol ppm of diallyl maleate increased the melt strength (“MS”) of the ethylene / BAIIM copolymer compared to the melt strength of the baseline ethylene homopolymer (comparative sample or “CS”) produced under the same or substantially the same I2 and polymerization conditions. The baseline ethylene homopolymer had an I2 value of 4.00 g / 10 min and a melt strength of 13.84 cN. The ethylene / BAIIM copolymers in IE1, IE2, and IE3 had corresponding I2 / melt strength values: IE1 3.67 / 16.36 cN (melt strength increased by 18% compared to the baseline), IE2 4.0 / 17.63 (melt strength increased by 27% compared to the baseline), and IE3 3.99 / 17.09 cN (melt strength increased by 23% compared to the baseline).

[0163] Table 5 – Results using diallyl maleate as MFBA

[0164]

[0165]

[0166] Example 2: (D) Vi )4 as a multifunctional branching agent

[0167] Polymerization was carried out in an adiabatic, continuous stirred tank reactor. The reactor pressure was approximately 2000 bar. A certain amount of propylene was used as a chain transfer agent (CTA) to control the final polymer melt index to ~4 g / 10 min. Ethylene and propylene were fed to the top of the reactor via a stirring shaft at 60°C. TPO diluted to 1 wt% in mineral oil was injected into one side of the reactor to initiate the reaction, thereby maintaining the reactor temperature at 220°C. (D...) Vi4. Feed is introduced into a separate injector located on one side of the reactor. The reactor residence time is approximately 1.5 minutes. A single outlet on the bottom of the reactor contains all unreacted reactants and polymer. The polymer is separated from the remaining reactants by devolatilization in a low-pressure separator operating at 200°C and 15 bar. The resulting molten polymer is then extruded through a granulator and collected.

[0168] Table 2 provides (D) Vi The structure of )4. (D) Vi )4 does not contain acrylate or methacrylate groups, and (D Vi )4 is not a product of butadiene polymerization. (D) Vi )4 contains one type of carbon-carbon double bond (p=1). (D) Vi Each molecule, n1 = 4, has four of these double bonds, resulting in a reactivity ratio of 0.4. Therefore, the R value is calculated to be 10. Therefore, (D Vi )4 satisfies parameters (A) and (B) (Equation 1), and is therefore an MFBA as defined herein.

[0169] From (D) Vi Data for MFBA, as an embodiment of the present invention, are shown in Table 6. Compared to the melt strength of the baseline ethylene homopolymer produced under the same or substantially the same polymerization conditions at I2, the addition of 40 mol ppm to 130 mol ppm of (D...)... Vi )4 increased ethylene / (D Vi Melt strength of the copolymer (excluding D) Vi The baseline ethylene homopolymer of 4 has a melt strength of 3.3 cN, and the ethylene / (D) Vi Each of the 4 copolymers has a melt strength greater than 6 cN.

[0170] As shown in Table 6, the baseline ethylene homopolymer has an I2 value of 4.15 g / 10 min and a melt strength of 3.32 cN. The ethylene / (D) ratio in IE4, IE5, and IE6... Vi The copolymers IE4 have corresponding I2 / melt strength values: IE4 3.69 / 7.65cN (melt strength increased by 130% from baseline), IE5 3.79 / 6.33 (melt strength increased by 91% from baseline) and IE6 3.68 / 8.37 (melt strength increased by 150% from baseline).

[0171] Table 6: Use of (D) Vi ) 4 As a result of MFBA

[0172]

[0173]

[0174] It is particularly desirable that this disclosure is not limited to the embodiments and descriptions contained herein, but includes modifications of those embodiments that include portions of embodiments appearing within the scope of the following claims and combinations of elements of different embodiments.

Claims

1. A method, the method comprising: A multifunctional branching agent MFBA is provided, wherein the multifunctional branching agent is 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane; The MFBA is reacted with ethylene under polymerization conditions; and An ethylene polymer composition comprising ethylene units and the units of the MFBA is formed.

2. The method of claim 1, wherein the method comprises reacting ethylene and MFBA in a tubular reactor; and An ethylene polymer composition comprising ethylene units and the units of the MFBA is formed.

3. The method of claim 1, wherein the method comprises reacting ethylene and the MFBA in an autoclave reactor; and An ethylene polymer composition comprising ethylene units and the units of the MFBA is formed.

4. The method according to any one of claims 1 to 3, the method comprising reacting the ternary comonomer with the ethylene and the MFBA; and An ethylene polymer composition comprising ethylene units, units of the MFBA, and units of the ternary comonomer is formed.

5. An ethylene polymer composition comprising an ethylene polymer, wherein the ethylene polymer comprises: Ethylene unit; and A multifunctional branching agent MFBA unit, wherein the multifunctional branching agent is 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-cyclotetrasiloxane; and Optional ternary comonomer unit, wherein the ternary comonomer is selected from the group consisting of: α-olefins, acrylates, methacrylates, vinyl acetate and vinyltrimethoxysilane.

6. The ethylene polymer composition according to claim 5, wherein the ethylene polymer comprises units of a ternary comonomer.

7. An article comprising the ethylene polymer composition according to claim 5 or 6.

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