Addition of coupling agent during organolithium initiated polymerizations

Claim 2

In a process for the polymerization of at least one polymerizable monomer comprising a polymerizable conjugated diene, polymerizable monovinyl-substituted aromatic compound, or both, under polymerization conditions with an organolithium initiator, the improvement which comprises adding to the polymerization reaction system commencing after at least about 3 percent monomer conversion and prior to about 75 percent conversion at least one nonpolymerizable silicon or tin coupling agent essentially continuously during at least a portion of the remaining course of said polymerization, thereby preparing a polymer of improved processability.

Claim 3

A process according to claim 1 wherein said polymerizable conjugated diene contains 4 to 12 carbon atoms per molecule, and said monovinyl-substituted aromatic compound contains 8 to 20 carbon atoms per molecule.

Claim 4

The process according to claim 2 wherein said adding of said nonpolymerizable coupling agent extends from after about 3 percent conversion up to about 30 percent conversion of said monomers.

Claim 5

A process according to claim 2 wherein said nonpolymerizable silicon or tin coupling agent is represented by the general formulae R a MZ b or R c Z d SiSiZ d R c wherein each R is a hydrocarbyl radical of 1 to 20 carbon atoms per molecule; M is Si or Sn; Z is halogen, --OR, or hydrogen; b is an integer of 2 to 4, a is 0, 1, or 2, such that a plus b is equal to 4; said halogen is fluorine, chlorine, bromine, or iodine; c is 0, 1, or 2; d is 1, 2, or 3; such that c plus d is equal to 3.

Claim 6

A process according to claim 4, employing a ratio of equivalents of Z in said coupling agent to lithium in said organolithium initiator of about 0.01:1 to 1.5:1.

Claim 7

The process according to claim 5 wherein said organolithium initiator is employed in an amount sufficient to provide about 0.2 to 100 milliequivalents of lithium in said initiator per 100 grams of said polymerizable monomer employed.

Claim 8

The process according to claim 6 further employing a randomizer during said polymerization reaction, and said randomizer is a polar material and is an ether, thioether, tertiary amine, or alkali metal alkoxide.

Claim 9

The process according to claim 6 wherein said coupling agent is said R a MZ b wherein M is said silicon.

Claim 10

The process according to claim 8 wherein said coupling agent is a silicon tetrahalide or tetraalkyl orthosilicate.

Claim 11

The process according to claim 9 wherein said polymerizable monomer is butadiene; said organolithium initiator is n-butyllithium; and said coupling agent is silicon tetrachloride.

Claim 12

The process according to claim 9 wherein said polymerizable monomer is butadiene and styrene, the resulting polymer is a butadiene/styrene copolymer, said organolithium initiator is n-butyllithium, and said coupling agent is silicon tetrachloride.

Claim 13

The process according to claim 7 wherein said randomizer is tetrahydrofuran or potassium tert-amyloxide, said polymerizable monomer is butadiene and styrene or is isoprene and styrene, said coupling agent is silicon tetrachloride or tetraethyl orthosilicate, and said initiator is n-butyllithium or is multilithium prepared from n-butyllithium and divinylbenzene.

Claim 14

In a process for the polymerization of at least one polymerizable monomer with an organolithium initiator, the improvement comprising adding to the polymerization reaction system commencing after at least about 3 percent monomer conversion up to about 30 percent conversion at least one nonpolymerizable coupling agent essentially continuously during at least a portion of the remaining course of said polymerization, continuing said polymerization to substantially complete monomer conversion, and shortstopping said polymerization, wherein said polymerizable monomer is at least one polymerizable conjugated diene, at least one polymerizable monovinyl-substituted aromatic compound, or both; wherein said nonpolymerizable coupling agent can be represented by the general formulae R a MZ b or R c Z d Si-SiZ d R c wherein each R is a hydrocarbyl radical or from 1 to 20 carbon atoms per molecule; M is Si or Sn; Z is halogen, --OR, or hydrogen; a is 0, 1, or 2, b is 2, 3, or 4, such that a plus b is equal to 4; said halogen is fluorine, chlorine, bromine, or iodine; c is 0, 1, or 2, d is 1, 2, or 3, such that c plus d is equal to 3.

Claim 15

In a process for the polymerization of at least one polymerizable monomer with an organolithium initiator, the improvement comprising adding to the polymerization reaction system commencing after at least about 3 percent monomer conversion up to about 30 percent conversion at least one nonpolymerizable coupling agent essentially continuously during at least a portion of the remaining course of said polymerization, continuing said polymerization to substantially complete monomer conversion, and shortstopping said polymerization, wherein said polymerizable monomer is at least one polymerizable conjugated diene, at least one polymerizable monovinyl-substituted aromatic compound, or both; wherein said nonpolymerizable coupling agent can be represented by the general formulae R a MZ b or R c Z d Si-SiZ d R c wherein each R is a hydrocarbyl radical or from 1 to 20 carbon atoms per molecule; M is Si or Sn; Z is halogen, --OR, or hydrogen; a is 0, 1, or 2, b is 2, 3, or 4, such that a plus b is equal to 4; said halogen is fluorine, chlorine, bromine, or iodine; c is 0, 1, or 2, d is 1, 2, or 3, such that c plus d is equal to 3.

Claim 16

A process according to claim 13 wherein said polymerizable conjugated diene contains 4 to 12 carbon atoms per molecule, and said monovinyl-substituted aromatic compound contains 8 to 20 carbon atoms per molecule.

Claim 17

The process according to claim 14 wherein said adding of said nonpolymerizable coupling agent continues up to essentially complete monomer conversion.

Claim 18

The process according to claim 15 wherein said adding of said nonpolymerizable coupling agent extends up to about 75 percent conversion of said monomer.

Claim 19

The process according to claim 16 wherein said adding of said nonpolymerizable coupling agent extends from after about 3 percent conversion up to about 30 percent conversion of said monomers.

Claim 20

A process according to claim 13 wherein is employed a ratio of equivalents of Z in said coupling agent to lithium in said organolithium initiator of about 0.01:1 to 1.5:1.

Claim 21

The process according to claim 18 wherein said organolithium initiator is employed in an amount sufficient to provide about 0.2 to 100 milliequivalents of lithium in said initiator per 100 grams of said polymerizable monomer employed.

Claim 22

The process according to claim 19 further employing a randomizer during said polymerization reaction, and said randomizer is a polar material and is an ether, thioether, tertiary amine, or alkali metal alkoxide.

Claim 23

The process according to claim 19 wherein said coupling agent is said R a MZ b .

Claim 24

The process according to claim 21 wherein said coupling agent is a silicon tetrahalide.

Claim 25

The process according to claim 22 wherein said polymerizable monomer is a conjugated diene and is butadiene; said organolithium initiator is n-butyllithium; and said coupling agent is silicon tetrachloride.

Claim 26

The process according to claim 22 wherein said polymerizable monomer is butadiene and styrene, the resulting polymer is a butadiene/styrene copolymer, said organolithium initiator is n-butyllithium; and said coupling agent is silicon tetrachloride.

Claim 27

The process according to claim 20 wherein said randomizer is tetrahydrofuran or potassium tert-amyloxide, said polymerizable monomer is butadiene and styrene or is isoprene and styrene, said coupling agent is silicon tetrachloride, and said initiator is n-butyllithium or is multilithium prepared from n-butyllithium and divinylbenzene.

Claim 28

In a process for the polymerization of at least one polymerizable monomer with an organolithium initiator, the improvement comprising adding to the polymerization reaction system commencing after at least about 3 percent monomer conversion up to about 75 percent conversion at least one nonpolymerizable coupling agent essentially continuously during at least a portion of the remaining course of said polymerization, continuing said polymerization to substantially complete monomer conversion, and shortstopping said polymerization, wherein said polymerizable monomer is at least one polymerizable conjugated diene, at least one polymerizable monovinyl-substituted aromatic compound, or both; wherein said nonpolymerizable coupling agent can be represented by the general formulae R a MZ b or R c Z d Si-SiZ d R c wherein each R is a hydrocarbyl radical or from 1 to 20 carbon atoms per molecule; M is Si or Sn; Z is halogen, --OR, or hydrogen; a is 0, 1, or 2, b is 2, 3, or 4, such that a plus b is equal to 4; said halogen is fluorine, chlorine, bromine, or iodine; c is 0, 1, or 2, d is 1, 2, or 3, such that c plus d is equal to 3.

Claim 29

In a process for the polymerization of at least one polymerizable monomer with an organolithium initiator, the improvement comprising adding to the polymerization reaction system commencing after at least about 3 percent monomer conversion up to about 75 percent conversion at least one nonpolymerizable coupling agent essentially continuously during at least a portion of the remaining course of said polymerization, continuing said polymerization to substantially complete monomer conversion, and shortstopping said polymerization, wherein said polymerizable monomer is at least one polymerizable conjugated diene, at least one polymerizable monovinyl-substituted aromatic compound, or both; wherein said nonpolymerizable coupling agent can be represented by the general formulae R a MZ b or R c Z d Si-SiZ d R c wherein each R is a hydrocarbyl radical or from 1 to 20 carbon atoms per molecule; M is Si or Sn; Z is halogen, --OR, or hydrogen; a is 0, 1, or 2, b is 2, 3, or 4, such that a plus b is equal to 4; said halogen is fluorine, chlorine, bromine, or iodine; c is 0, 1, or 2, d is 1, 2, or 3, such that c plus d is equal to 3.