Process for production of polymers having increased 1,2-microstructure
AssigneeThe Firestone Tire & Rubber Company
InventorsJames E. Hall, Donald N. Schulz
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Abstract
A process and catalyst system is disclosed herein for the preparation of (co)polymers having a 1,2-microstructure of between about 20 and about 65 percent. These (co)polymers are prepared in a hydrocarbon or non-polar solvent from a monomer system which contains at least one 1,3-diene monomer. The catalyst system which is employed in the production of the (co)polymer is a combination of an anionic initiator based on lithium and a phosphine oxide modifier which is substituted with three saturated heterocyclic rings, each hetero ring containing one nitrogen atom and either four, five or six carbon atoms.
Claims20
A process for the preparation of a homopolymer of a 1,3-diene monomer said homopolymer containing a 1,2-microstructure ranging between about 20 and about 65 percent which process comprises polymerizing said 1,3-diene monomer in an in inert non-polar solvent system in the presence of a catalytically effective amount of a catalyst comprising:
- (a) an anionic initiator based on lithium, said anionic initiator being selected from the group consisting of organolithium catalysts having the formula R(Li).sub.x wherein R represents a hydrocarbyl radical of 1 to 20 carbon atoms per R group and x is an integer of 1-4, phenyllithium, naphthyllithium, 4-butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, 4-butylcyclohexyllithium, 4-cyclohexylbutyllithium, 1,4-dilithiobutane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,4-dilithionaphthalene, 9,10-dilithioanthracene, 1,2-dilithio-1,2-diphenylethane, 1,3,5-trilithiopentane, 1,5,15-trilithioeicosane, 1,3,5-trilithiocyclohexane, 1,3,5,8-tetralithiodecane, 1,5,10,20-tetralithioeicosane, 1,2,4,6-tetralithiocyclohexane, 4,4'-dilithiobiphenyl, lithium dialkyl amines, lithium dialkyl phosphines, lithium alkyl aryl phosphines and lithium diaryl phosphines, and
- (b) a phosphine oxide modifier represented by the structural formula:
- ##STR2## wherein x represents an integer of 3, 4 or 5, in which the molar ratio of the anionic initiator (a) to the phosphine oxide modifier (b) ranges between about 1.0/0.1 to about 1.0/10.0 in which the temperature of polymerization initiation is at least 0.degree. C. and in which the millimoles of the anionic initiator per 100 grams of the 1,3-diene monomer ranges between about 0.2 and about 100.
A process for the preparation of a copolymer formed by polymerizing:
- (A) 40 to 100 percent of at least one 1,3-diene monomer, and
- (B) 0 to 60 percent of one or more reactive monomers which are copolymerizable with said 1,3-diene monomers;
- in an inert non-polar solvent in the presence of a catalytically effective amount of a catalyst comprising:
- (a) an anionic initiator based on lithium, said anionic initiator being selected from the group consisting of organolithium catalysts having the formula R(Li).sub.x wherein R represents a hydrocarbyl radical of 1 to 20 carbon atoms per R group and x is an integer of 1-4, phenyllithium, naphthyllithium, 4-butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, 4-butylcyclohexyllithium, 4-cyclohexylbutyl, 1,4-dilithiobutane, 1,10-dilithiodecane, 1,20-dilithioeicosane, 1,4-dilithiobenzene, 1,4-dilithionaphthalene, 9,10-dilithioanthracene, 1,2-dilithio-1,2-diphenylethane, 1,3,5-trilithiopentane, 1,5,15-trilithioeicosane, 1,3,5-trilithiocyclohexane, 1,3,5,8-tetralithiodecane, 1,5,10,20-tetralithioeicosane, 1,2,4,6-tetralithiocyclohexane, 4,4'-dilithiobiphenyl, lithium dialkyl amines, lithium dialkyl phosphines, lithium alkyl aryl phosphines and lithium diaryl phosphines, and
- (b) a phosphine oxide modifier represented by the structural formula:
- ##STR3## wherein x represents an integer of 3, 4 or 5, in which the molar ratio of the anionic initiator (a) to the phosphine oxide modifier (b) ranges between about 1.0/0.1 to about 1.0/10.0 in which the temperature of polymerization initiation is at least 0.degree. C. and in which the millimoles of the anionic initiator per 100 grams of the (A+B) monomers ranges between about 2.0 and about 100, said copolymer containing a 1,2-microstructure in the 1,3-diene monomer contributed units ranging between about 20 and about 65 percent.
Dependencies are inferred from the claim text.