Method for producing polydienes and polydiene copolymers with reduced cold flow

Patent metadata

Field	Value
Publication number	US-9512263-B2
Application number	US-201214363944-A
Country	US
Kind code	B2
Filing date	Dec 10, 2012
Priority date	Dec 9, 2011
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A method for preparing a coupled polymer, the method comprising the steps of: (i) polymerizing monomer to form a reactive polymer; (ii) reacting the reactive polymer with a polyisocyanate having a functionality of X to form an intermediate polymer product; and (iii) reacting the intermediate polymer product with a polyol having a functionality of Y to form the coupled polymer product, where X+Y≧5.

First claim

What is claimed is:

1. A method for preparing a coupled polymer having advantageous resistance to coldflow, the method comprising the steps of:
(i) polymerizing conjugated diene monomer, and optionally monomer copolymerizable therewith, to form a reactive polymer within a polymerization mixture;
(ii) adding a diisocyanate into the polymerization mixture, thereby reacting the reactive polymer with the diisocyanate to form an intermediate polymer product; and
(iii) after the diisocyanate has reacted with the reactive polymer adding a triol into the polymerization mixture including the intermediate polymer, thereby reacting the intermediate polymer product with a triol to form the coupled polymer product, where the coupled polymer product is defined by the formula:

 where R 10 is a multivalent organic group deriving from the triol, R 11 is a divalent organic group deriving from the diisocyanate, and each R 12 is a residue of the reactive polymer; and
 where the monomer is polymerized with a lanthanide-based catalyst or a organolithium initiator with a molar ratio of the isocyanate functionality of the diisocyanate to the moles of lithium cation in the organolithium initiator (—NCO/Li) from about 50:1 to about 1:1.

2. The method of claim 1 , where the diisocyanate is a diisocyanato hydrocarbyl selected from the group consisting of diisocyanatoalkyls, diisocyanatocycloalkyls, diisocyantoaryls, diisocyanatoalkenyls, and diisocyanatoalkynyls.

3. The method of claim 1 , where the diisocyanate is selected from the group consisting of methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 4,4′-methylenebis (cyclohexyl isocyanate).

4. The method of claim 1 , where the triol is selected from the group consisting of alkyltriols, cycloalkyltriols, aryltriols, alkenyltriols, and alkynyltriols.

5. The method of claim 1 , where the triol is glycerol.

6. The method of claim 1 , where said step of polymerizing monomer includes polymerizing conjugated diene monomer and monomer copolymerizable therewith.

7. The method of claim 1 , where said step of polymerizing takes place using anionic polymerization techniques.

8. The method of claim 1 , where said step of polymerizing takes place using an organolithium initiator.

9. The method of claim 1 , where said step of polymerizing takes place using a lanthanide-based catalyst system.

10. The method of claim 1 , where the monomer is polymerized with an organolithium initiator and the molar ratio of the isocyanate functionality to the moles of lithium cation (—NCO/Li) is from about 10:1 to about 1:1.

11. The method of claim 1 , where the monomer is polymerized with an organolithium initiator and molar ratio of the isocyanate functionality to the moles of lithium cation (—NCO/Li) is from about 5:1 to about 1:1.

12. The method of claim 1 , where the monomer is polymerized with a lanthanide-based catalyst and the molar ratio of the isocyanate functionality of the polyisocyanate to the moles of lanthanide metal in the lanthanide-based catalyst (—NCO/Ln) is from about 1000:1 to about 1:1.

13. The method of claim 1 , where the coupled polymer product includes two or more polydiene or polydiene copolymers coupled through a residue of the polyol.

Assignees

• Bridgestone Corp

Inventors

• Mccauley Kevin M
• Hogan Terrence E
• Hergenrother William L

Classifications

• C08G18/73

  acyclic · CPC title

• C08C19/34

  reacting with oxygen or oxygen-containing groups · CPC title

• C08C19/22 Primary

  Incorporating nitrogen atoms into the molecule · CPC title

• C08G2380/00

  Tyres · CPC title

• C08F36/06

  Butadiene · CPC title