# US 10,865,299 B2 · Multi-modal polyisoolefin compositions and processes therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,299 B2 - Document ID: US10865299B2 - Status: Granted - Kind: B2 - Application number: 16/336,731 - Filed: 2017-09-28 - Published: 2020-02-13 - Granted: 2020-12-15 - Earliest claimed: 2016-09-29 - Assignees: Arlanxeo Canada Inc. - Applicants: Arlanxeo Canada Inc. - Inventors: Sharon Guo; Gregory J. E. Davidson; Brianna Binder - Web page: https://patentgrep.com/patent/US10865299B2 ## CPC - C08L 23/283: Iso-olefin halogenated homopolymers or copolymers - B60C 1/0008: {Compositions of the inner liner} - C08L 23/22: Copolymers of isobutene; Butyl rubber; Homopolymers or copolymers of other iso-olefins - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES ## Abstract A polyisoolefin-based polymer composition having a multimodal molecular weight distribution is described, which can be prepared by the late addition of a chain transfer agent to the polymerization process. The polymer composition has a low molecular weight fraction having a peak molecular weight (Mp) of less than about 100,000 g/mol and a high molecular weight fraction having a peak molecular weight (Mp) of greater than about 250,000 g/mol, the low molecular weight fraction present in the composition in an amount less than the high molecular weight fraction. Cured articles produced from the polyisoolefin-based polymer composition exhibit improved processability while maintaining physical properties. ## Claims ### Claim 1 A process for producing a polyisoolefin-based polymer composition having a multimodal molecular weight distribution, the process comprising: polymerizing an isoolefin in a first step in the absence of a chain transfer agent; and, continuing to polymerize the isoolefin in a second step in the presence of a chain transfer agent to produce a polyisoolefin-based polymer composition comprising a multimodal molecular weight distribution comprising a low molecular weight fraction having a peak molecular weight (Mp) of less than about 100,000 g/mol and a high molecular weight fraction having a peak molecular weight (Mp) of greater than about 250,000 g/mol, the low molecular weight fraction present in the composition in an amount less than the high molecular weight fraction. ### Claim 2 (depends on 1) The process according to claim 1, wherein the polymerizing is a solution polymerization process, a slurry polymerization process, a batch process or a continuous process. ### Claim 3 (depends on 1) The process according to claim 1, wherein the first step is conducted for a time in a range of 10-45 minutes. ### Claim 4 (depends on 1) The process according to claim 1, wherein the chain transfer agent is added to the process when 25% or more conversion of monomers to polymer has been achieved, and the chain transfer agent. ### Claim 5 (depends on 1) The process according to claim 1, wherein one or more co-monomers and/or branching agents are added to the process after polymerization has been initiated. ### Claim 6 (depends on 1) The process according to claim 1, wherein the isoolefin is isobutene, and the isobutene is copolymerized with β-pinene or isoprene. ### Claim 7 (depends on 1) The process according to claim 1, further comprising brominating or chlorinating the polyisoolefin-based polymer. ### Claim 8 (depends on 1) A polyisoolefin-based polymer composition produced by the process of claim 1. ### Claim 9 (depends on 8) The composition according to claim 8 having a bimodal molecular weight distribution. ### Claim 10 (depends on 8) The composition according to claim 8, wherein the low molecular weight fraction is present in an amount of 5-50 wt %, based on total weight of polymer. ### Claim 11 (depends on 8) The composition according to claim 8, wherein the polyisoolefin-based polymer composition comprises polyisobutylene. ### Claim 12 (depends on 8) The composition according to claim 8, wherein the polyisoolefin-based polymer composition comprises a copolymer of isobutene and isoprene. ### Claim 13 (depends on 12) The composition according to claim 12, wherein the copolymer is brominated or chlorinated. ### Claim 14 (depends on 1) A cured article comprising a polyisoolefin-based polymer composition, wherein the polyisoolefin-based polymer composition is produced by the process of claim 1. ### Claim 15 (depends on 14) The cured article of claim 14, wherein the cured article is a tire inner liner, a tire inner tube, seals, a gasket or a pharmaceutical closure. ### Claim 16 (depends on 2) The process according to claim 2, wherein the solution polymerization process is a plug flow process. ### Claim 17 (depends on 4) The process according to claim 4, wherein the chain transfer agent comprises 2,4,4-trimethyl-1-pentene. ### Claim 18 (depends on 16) The process of claim 16, wherein the chain transfer agent comprises 2,4,4-trimethyl-1-pentene, and the isoolefin is isobutene, and the isobutene is copolymerized with β-pinene or isoprene. ### Claim 19 (depends on 18) The process of claim 18, further comprising brominating or chlorinating the polyisoolefin-based polymer. ### Claim 20 (depends on 18) The process according to claim 18, wherein the first step is conducted for a time in a range of 10-45 minutes or the chain transfer agent is added to the process when 25% or more conversion of monomers to polymer has been achieved; and one or more co-monomers and/or branching agents are added to the process after polymerization has been initiated.