US 12,410,274 B2
Anionic dispersion polymerization process to make random copolymer rubber
David M. Roggeman, North Royalton, OH (US); James J. Kuhel, III, Stow, OH (US); and Terrence E. Hogan, Uniontown, OH (US)
Assigned to Bridgestone Americas Tire Operations, LLC, Nashville, TN (US)
Appl. No. 17/768,728
Filed by Bridgestone Americas Tire Operations, LLC, Nashville, TN (US)
PCT Filed Oct. 14, 2020, PCT No. PCT/US2020/055602
§ 371(c)(1), (2) Date Apr. 13, 2022,
PCT Pub. No. WO2021/076640, PCT Pub. Date Apr. 22, 2021.
Claims priority of provisional application 62/914,770, filed on Oct. 14, 2019.
Prior Publication US 2024/0158561 A1, May 16, 2024
Int. Cl. C08F 236/06 (2006.01); C08F 212/08 (2006.01); C08F 236/10 (2006.01); C08F 297/02 (2006.01); C08F 297/04 (2006.01)
CPC C08F 297/044 (2013.01) [C08F 212/08 (2013.01); C08F 236/06 (2013.01); C08F 236/10 (2013.01); C08F 297/023 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A process for producing a copolymer by anionic dispersion polymerization comprising:
adding to a first polymerization reactor: a first monomer charge comprising a first conjugated diene monomer and optionally a first vinyl aromatic monomer; organolithium polymerization initiator; and a non-aqueous dispersing medium,
wherein the first monomer charge is polymerized to form a first block of a dispersing agent, the first block being soluble in the non-aqueous dispersing medium, and
wherein at least 8% to 20% by wt of total monomer is provided by the first monomer charge, the total monomer being the sum of all monomer charges; and
adding to a second polymerization reactor: the first block, the non-aqueous dispersing medium, a second monomer charge comprising a second vinyl aromatic monomer and a second conjugated diene monomer; and organolithium polymerization initiator,
wherein the second monomer charge is polymerized to form the copolymer, the copolymer being the polymerized reaction product of at least 30% to 90% by weight of the second vinyl aromatic monomer, based on a total weight of the copolymer, and at least 10% to 70% by weight of the second conjugated diene monomer, based on the total weight of the copolymer, and
wherein the second polymerization reactor produces an outlet stream comprising the copolymer and a second block of the dispersing agent, the second block being insoluble in the non-aqueous dispersing medium and linked with the first block to form the dispersing agent, and
wherein the dispersing agent disperses the copolymer in the non-aqueous dispersing medium,
adding coupling agent into the outlet stream, wherein the coupling agent attaches to the copolymer to increase the Mooney viscosity of the copolymer, wherein the coupling agent comprises a non-organometallic aromatic triester coupling agent.