# US 12,215,179 B2 · Conjugated diene-based polymer, branching agent, production method for conjugated diene-based polymer, oil extended conjugated diene-based polymer, rubber composition, and tire > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,179 B2 - Document ID: US12215179B2 - Status: Granted - Kind: B2 - Application number: 17/632,873 - Filed: 2020-07-22 - Published: 2022-09-01 - Granted: 2025-02-04 - Earliest claimed: 2019-08-06 - Assignees: Asahi Kasei Kabushiki Kaisha - Applicants: Asahi Kasei Kabushiki Kaisha - Inventors: Shogo Sumitani; Kenta Hisamura; Shinichi Sekikawa; Miki Kyo; Shuri Tobo - Web page: https://patentgrep.com/patent/US12215179B2 ## CPC - C08F 236/10: with vinyl-aromatic monomers - B60C 1/00: Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition - B60C 1/0016: {Compositions of the tread} - B60C 1/0025: {Compositions of the sidewalls} - B60C 1/0041: {Compositions of the carcass layers} - C08C 19/22: Incorporating nitrogen atoms into the molecule - C08C 19/25: Incorporating silicon atoms into the molecule - C08F 236/06: Butadiene - C08K 3/04: Carbon - C08K 3/36: Silica - B60C 2001/005: {Compositions of the bead portions, e.g. clinch or chafer rubber or cushion rubber} - Y02T 10/86: Optimisation of rolling resistance, e.g. weight reduction - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES - C08C: TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A conjugated diene-based polymer of the present invention has a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 8 or more, has a change (ΔT) of an oxidation onset temperature caused through application of a thermal load of 11.9° C. or less, and contains an aromatic vinyl compound monomer unit. ## Claims ### Claim 1 A conjugated diene-based polymer having a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 8 or more, having a change (ΔT) of an oxidation onset temperature caused through application of a thermal load of 11.9° C. or less, and comprising an aromatic vinyl compound monomer unit. ### Claim 2 (depends on 1) The conjugated diene-based polymer according to claim 1, wherein the change (ΔT) of an oxidation onset temperature caused through application of the thermal load is 10° C. or less. ### Claim 3 (depends on 1) The conjugated diene-based polymer according to claim 1, having a modification ratio of 60% by mass or more. ### Claim 4 (depends on 1) The conjugated diene-based polymer according to claim 1, wherein a content of the aromatic vinyl compound monomer unit is 10% by mass or more. ### Claim 5 (depends on 1) The conjugated diene-based polymer according to claim 1, wherein the conjugated diene-based polymer is a conjugated diene-based polymer having a star polymer structure having 3 or more branches, at least one branched chain of the star polymer structure comprises a portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, and the portion derived from the vinyl-based monomer containing the alkoxysilyl group or the halosilyl group further comprises a main chain branch structure. ### Claim 6 (depends on 5) The conjugated diene-based polymer according to claim 5, wherein the portion derived from the vinyl-based monomer containing the alkoxysilyl group or the halosilyl group is a monomer unit based on a compound represented by the following formula (1) or (2), and contains a branch point of a polymer chain containing the monomer unit based on the compound represented by the formula (1) or (2), and at least one end of the conjugated diene-based polymer is modified with a nitrogen atom-containing group: wherein in the formula (1), R1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof; R2 and R3 each independently represent an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof; each of R1 to R3, if present in a plural number, is respectively independent; X1 represents an independent halogen atom; and m represents an integer of 0 to 2, n represents an integer of 0 to 3, l represents an integer of 0 to 3, and (m+n+l) is 3; in the formula (2), R2 to R5 each independently represent an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof, and each of R2 to R5, if present in a plural number, is respectively independent; X2 and X3 represent an independent halogen atom; m represents an integer of 0 to 2, n represents an integer of 0 to 3, l represents an integer of 0 to 3, and (m+n+l) is 3; and a represents an integer of 0 to 2, b represents an integer of 0 to 3, c represents an integer of 0 to 3, and (a+b+c) is 3. ### Claim 7 (depends on 6) The conjugated diene-based polymer according to claim 6, containing the monomer unit based on the compound represented by the formula (1) wherein R1 is a hydrogen atom, and m is 0. ### Claim 8 (depends on 6) The conjugated diene-based polymer according to claim 6, containing the monomer unit based on the compound represented by the formula (2) wherein m is 0 and b is 0. ### Claim 9 (depends on 6) The conjugated diene-based polymer according to claim 6, containing the monomer unit based on the compound represented by the formula (1) wherein R1 is a hydrogen atom, m is 0, and l is 0. ### Claim 10 (depends on 6) The conjugated diene-based polymer according to claim 6, containing the monomer unit based on the compound represented by the formula (2) wherein m is 0, l is 0, a is 0, and b is 0. ### Claim 11 (depends on 6) The conjugated diene-based polymer according to claim 6, containing the monomer unit based on the compound represented by the formula (1) wherein R1 is a hydrogen atom, l is 0, and n is 3. ### Claim 12 (depends on 1) An oil extended conjugated diene-based polymer, comprising: 100 parts by mass of the conjugated diene-based polymer according to claim 1; and 1 to 60 parts by mass of an extender oil. ### Claim 13 (depends on 1) A rubber composition comprising: a rubber component; and 5.0 parts by mass or more and 150 parts by mass or less of a filler based on 100 parts by mass of the rubber component, wherein the rubber component contains, based on a total amount of the rubber component, 10% by mass or more of the conjugated diene-based polymer according to claim 1.