JP-2026514335-A - Method for producing branched polyolefins

Abstract

This disclosure provides a process. In embodiments, the process comprises contacting a single polymerization catalyst and co-catalyst in a single reactor with (i) an ethylene monomer and an optional C3- C8 α-olefin comonomer, (ii) an alkyl-aluminum chain transfer agent, and (iii) an alkyl-zinc chain transfer agent under polymerization conditions at a temperature of 160 °C to 250°C. The process comprises forming an ethylene-based polymer having an I10 / I2 value greater than 8.0 and a vinyl content greater than 50/1,000,000C.

Inventors

• スン、リーシン
• カージャラ、トーマス ウェズリー
• カーナハン、エドモンド エム．

Assignees

• ダウ グローバル テクノロジーズ エルエルシー

Dates

Publication Date

20260511

Application Date

20240228

Priority Date

20230328

Claims (5)

1. It is a process, Under polymerization conditions at temperatures of 160°C to 250°C, a single polymerization catalyst and co-catalyst in a single reactor, (i) Ethylene monomers and optionally selected C3 - C8 α-olefin comonomers, (ii) Contact with alkyl-aluminum chain transfer agent and (iii) alkyl-zinc chain transfer agent, A process comprising forming an ethylene-based polymer having an I¹⁰ / I² value greater than 8.0 and a vinyl content greater than 50/1,000,000C.
2. The polymerization catalyst is of formula (1) It has, in the formula, M is titanium, zirconium, hafnium, or scandium. Each Y1 and Y2 is independently selected from the group consisting of ( C1 - C40 ) hydrocarbyl, ( C1 - C40 ) trihydrocarbylsilylhydrocarbyl, halogen, alkoxide, or amine, or the two Y groups together are a divalent hydrocarbylene, hydrocarbadiyl, or trihydrocarbylsilyl group. Each Ar1 and Ar2 is independently selected from the group consisting of ( C6 - C40 )aryls, substituted ( C6 - C40 )aryls, ( C3 - C40 ) heteroaryls, and substituted ( C3 - C40 ) heteroaryls. T1 is a divalent bridging group of 2 to 20 carbon atoms, independently containing a heteroatom containing Si, Ge, O, N, S, and P at any choice in each occurrence. The process according to claim 1, wherein each R1 , R2 , R3 , R4 , R5 , R6 , R7 , R8 , R9 , R10 , R11 , R12 , R13 , and R14 are independently selected from the group consisting of hydrogen, halogen, ( C1 - C40 ) hydrocarbyl, substituted ( C1 - C40 ) hydrocarbyl, ( C1 - C40 ) heterohydrocarbyl, substituted ( C1 - C40 ) heterohydrocarbyl, ( C6 - C40 ) aryl, substituted ( C6 - C40 ) aryl, ( C3 - C40 ) heteroaryl, and substituted ( C3 - C40 ) heteroaryl, and nitro ( NO2 ).
3. The process according to claim 1 or 2, wherein the polymerization catalyst has formula (2).
4. Under polymerization conditions at a temperature of 180°C to 250°C, the polymerization catalyst of formula (2) and co-catalysts, (i) Ethylene monomers and C3 - C8 α-olefin comonomers, (ii) Contact with alkyl-aluminum chain transfer agent and (iii) alkyl-zinc chain transfer agent, The process according to any one of claims 1 to 3, comprising forming an ethylene copolymer having an I10 / I2 value greater than 8.0 and a vinyl content greater than 50/1,000,000C.
5. Under polymerization conditions at a temperature of 180°C to 250°C, the polymerization catalyst of formula (2) and co-catalysts, (i) Ethylene monomers, and olefin comonomers selected from the group consisting of propylene, 1-butene, 1-hexene, 1-octene, and combinations thereof, (ii) Contact with triethylaluminum chain transfer agent and (iii) diethylzinc chain transfer agent, The process according to any one of claims 1 to 4, comprising forming an ethylene/ C3 - C8 α-olefin copolymer having an I10 / I2 value greater than 8.0 and a vinyl content greater than 50/1,000,000C.

Description

Olefin polymers with long-chain branching (LCB) are those containing one or more side-chain branches whose length is comparable to or longer than the critical entanglement length. It is known that the incorporation of long-chain branching (LCB) improves processability and increases melt strength in olefin polymers. Compared to linear olefin polymers of the same molecular weight, olefin polymers with LCB exhibit higher shear sensitivity, higher zero-shear viscosity, greater melt elasticity, greater impact strength, and higher melt strength ("melt strength" is the resistance to stretching during the extension of the molten olefin polymer). High melt strength is a desirable mechanical property in thermoforming, extrusion coating, and blow molding processes involving olefin polymers. Furthermore, olefin polymers containing LCB exhibit higher viscosity at low shear rates and lower viscosity at high shear rates compared to linear olefin polymers with the same molecular weight. Shear reduction is advantageous in polymer processing under high shear conditions. For linear low-density polyethylene (LLDPE), the common mechanism by which LCBs (Liquid Chain Links) are formed during olefin coordination polymerization (a form of addition polymerization mediated by transition metal catalysts) is the insertion of vinyl-terminated polymer chains generated by thermal termination at the transition metal catalyst site. The level of LCB formed by this mechanism is usually low due to the small number of vinyl-terminated polymer chain clusters. In contrast, low-density polyethylene (LDPE) produced by free radical polymerization is known for its excellent processability, stemming from its unique "dendritic" branch-on-branch structure. It is known that α,ω-dienes, such as decadienes, can be added during olefin polymerization to crosslink two polymer chains. The α,ω-diene approach is disadvantageous because it increases the risk of gelation in the reactor system and imposes logistical burdens due to the limited availability and high cost of α,ω-dienes in industrial-scale quantities. In this technical field, the need for alternative processes for generating long-chain branching in olefinic polymers is recognized. In particular, there is a need for processes to generate long-chain branching in olefinic polymers (especially ethylene-based polymers) through olefin coordination polymerization. This disclosure provides a process. In embodiments, the process comprises contacting a single polymerization catalyst and co-catalyst in a single reactor with (i) an ethylene monomer and an optional C3- C8 α-olefin comonomer, (ii) an alkyl-aluminum chain transfer agent, and (iii) an alkyl-zinc chain transfer agent under polymerization conditions at a temperature of 160 °C to 250°C. The process comprises forming an ethylene-based polymer having an I10 / I2 value greater than 8.0 and a vinyl content greater than 50/1,000,000C. This chart shows the chemical structures of different types of carbon-carbon double (unsaturated in polymer chains) bonds in vinylene, trisubstituted, vinyl, and vinylidene.This is a schematic diagram of the polymerization process according to an embodiment of the present disclosure.This graph shows the GPC curves and Mark-Houwink plots for comparative sample 1 and example 1 of the present invention.This graph shows the GPC curves and g' values for comparative sample 1 and example 1 of the present invention.This graph shows the DMS viscosity overlays for comparative sample 6 and examples 6 to 13 of the present invention.This graph shows the DMS tan-delta overlay for comparative sample 6 and examples 6 to 13 of the present invention. Definition Any reference to the Periodic Table of Elements refers to the Periodic Table of Elements published by CRC Press, Inc., 1990–1991. References to element groups in this table refer to a new notation for numbering groups. For the purposes of U.S. patent practice, the content of any referenced patent, patent application, or publication is incorporated herein by reference in its entirety, particularly with respect to the disclosure of definitions and general knowledge in the art (to the extent that it does not contradict any definitions specifically provided herein). (Or, the corresponding U.S. patent application of the publication is incorporated by reference in the same way.) The numerical ranges disclosed herein include all values from the lower limit to the upper limit (including the lower and upper limits). In the case of a range containing explicit values (e.g., 1 or 2, or 3–5, or 6 or 7), any sub-ranges between any two explicit values are included (e.g., in the case of the range 1–7 above, this includes sub-ranges such as 1–2, 2–6, 5–7, 3–7, 5–6, etc.). Unless otherwise objected, and unless implied by the context, all parts and percentages are based on weight, and all test methods are current as of the filing date of this disclosure. As used herein, "alkyl group" refers to a saturated hy