Promoters in the polymerization of monovinyl-aromatic compounds with primary lithium initiators

Claim 2

A process which comprises polymerizing at least one first monovinyl-substituted aromatic compound monomer with a primary hydrocarbyl lithium polymerization initiator and a 1,1-dialkylethylene promoter under solution polymerization conditions of temperature and pressure, wherein said process employs an amount of said 1,1-dialkylethylene promoter effective to promote said polymerization of said monovinyl-substituted aromatic monomer with said primary hydrocarbyl lithium initiator, and said 1,1-dialkylethylene promoter is represented by the formula: ##STR2## wherein each R is selected from hydrogen, methyl, or ethyl.

Claim 3

The process according to claim 1 wherein said monovinyl-substituted aromatic hydrocarbon contains 8 to 12 carbon atoms per molecule.

Claim 4

The process according to claim 2 wherein said monovinyl-substituted aromatic compound is styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 3-methylstyrene, alpha-methylstyrene, 4-ethylstyrene, 4-n-propylstyrene, 3-fluorostyrene, or 4-methoxystyrene.

Claim 5

The process according to claim 1 wherein said 1,1-dialkylethylene promoter is isobutene, 2-methyl-1-butene, 2-methyl-1-pentene, 2-ethyl-1-butene, 2-ethyl-1-pentene, 2-propyl-1-pentene, or mixture.

Claim 6

The process according to claim 4 wherein said effective amount of said 1,1-dialkylethylene is in the range of about 50:1 to 7500:1 weight ratio relative to said primary hydrocarbyl lithium compound.

Claim 7

The process according to claim 5 wherein said primary hydrocarbyl lithium initiator is represented by R'(CH 2 Li) x wherein R' is a valence bond, hydrogen, saturated aliphatic radical, monoolefinic aliphatic radical, which radicals can be aromatic or saturated cycloaliphatic substituted, x is an integer of 1 to 4, and R' contains 1 to 18 carbon atoms.

Claim 8

The process according to claim 6 wherein said primary hydrocarbyl lithium compound is methyllithium, ethyllithium, n-propyllithium, n-butyllithium, n-dodecyllithium, 4-phenylbutyllithium, 4-cyclohexylbutyl-lithium, 1,2-dilithioethane, 1,4-dilithiobutane, 1,4-dilithio-2-butene, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,3-dilithio-2-(lithiomethyl)propane, or 1,4-dilithio-2,3-di(lithiomethyl)butane.

Claim 9

The process according to claim 7 wherein is employed a ratio of said 1,1-dialkylethylene promoter:said primary hydrocarbon/lithium initiator of about 150:1 to 1000:1.

Claim 10

The process according to claim 8 wherein said polymerization conditions include a polymerization temperature in the range of about 0° to 150° C., and under a pressure sufficient to maintain polymerization components substantially in the liquid phase, and polymerization in a polymerization diluent.

Claim 11

The process according to claim 9 wherein said promoter is isobutylene and said initiator is n-butyllithium.

Claim 12

The process of claim 10 wherein said monovinyl-substituted aromatic monomer is styrene.

Claim 13

A process for the preparation of a polymer which comprises the steps of: polymerizing under solution polymerization conditions at least one monovinyl-substituted aromatic hydrocarbon monomer of 8 to 12 carbon atoms per molecule employing a primary hydrocarbyl lithium initiator and a 1,1-dialkylethylene promoter of the formula: ##STR3## wherein each R is hydrogen, methyl, or ethyl, effective to promote the polymerization of said monomer with said primary hydrocarbyl lithium initiator, employing a ratio of said promoter:primary hydrocarbyl lithium initiator in the range of about 50:1 to 7500:1, thereafter, after substantially complete polymerization of said monovinyl-substituted aromatic hydrocarbon, terminating with a catalyst-inactivating material selected from water and the lower alcohols.

Claim 14

A process for the preparation of a polymer which comprises the steps of: polymerizing under solution polymerization conditions at least one monovinyl-substituted aromatic hydrocarbon monomer of 8 to 12 carbon atoms per molecule employing a primary hydrocarbyl lithium initiator and a 1,1-dialkylethylene promoter of the formula: ##STR3## wherein each R is hydrogen, methyl, or ethyl, effective to promote the polymerization of said monomer with said primary hydrocarbyl lithium initiator, employing a ratio of said promoter:primary hydrocarbyl lithium initiator in the range of about 50:1 to 7500:1, thereafter, after substantially complete polymerization of said monovinyl-substituted aromatic hydrocarbon, terminating with a catalyst-inactivating material selected from water and the lower alcohols.

Claim 15

The process of claim 12 wherein said monovinyl-substituted aromatic monomer is styrene, said 1,1-dialkylethylene is isobutene, and said primary hydrocarbyl lithium initiator is n-butyllithium.