Butadiene polymerization process
AssigneeCompagnie Generale Des Etablissements Michelin
InventorYves de Zarauz
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Abstract
Homopolymers of butadiene and copolymers of butadiene with vinyl aromatic compounds or with other conjugated dienes, which polymers have a high content of trans-1,4 linkages and a low content of 1,2 linkages, are prepared by use of a novel anionic catalytic composition which comprises (a) an organo-lithium initiator and (b) a cocatalyst system comprising a compound of barium or strontium and an organometallic compound of a metal of Group IIB or IIIA of the Mendeleev periodic table of elements.
Claims15
A process of homopolymerizing butadiene or copolymerizing butadiene with other conjugated dienes or with vinyl aromatic compounds to form products having simultaneously a high content of more than about 70% of trans-1,4 linkages and a low content of less than about 5% of 1,2 linkages which comprises reacting the monomers in a reaction medium in the presence of an added anionic catalytic composition consisting of (a) an organo-lithium initiator and (b) a cocatalyst system consisting of a compound of barium or strontium and an organometallic compound of aluminum or zinc.
A process of homopolymerizing butadiene or copolymerizing butadiene with other conjugated dienes or with vinyl aromatic compounds to form products having simultaneously a high content of more than about 70% of trans-1,4 linkages and a low content of less than about 5% of 1,2 linkages which comprises reacting the monomers in a reaction medium in the presence of an added anionic catalytic composition consisting of
- a. an organo-lithium initiator selected from the group consisting of metallic lithium, ethyl-lithium, n-butyl lithium, isobutyl-lithium, sec.-butyl-lithium, ter.-butyl-lithium, isopropyl-lithium, n-amyl-lithium, isoamyl-lithium, allyl-lithium, propenyl-lithium, isobutenyl-lithium, polybutadienyl-lithium, polyisoprenyl-lithium, polystyryl-lithium, 1,4-dilithium butane, 1-5-dilithium pentane, 1,20-dilithium eicosane, benzyl-lithium, phenyl-lithium, 1,1-diphenyl-methyl-lithium, the polylithium reaction product of metallic lithium with 1,1-diphenylethylene, the polylithium reaction product of metallic lithium with trans-stilbene, the polylithium reaction product of metallic lithium with tetraphenylethylene, lithium-naphthalene, lithium-anthracene, lithium-chrysene and lithium-diphenyl;
- and
- b. a cocatalyst system consisting of (b.sub.1) a compound of barium or strontium selected from the group consisting of barium hydride, strontium hydride;
- barium naphthenate, barium methanolate, strontium methanolate, barium ethanolate, strontium ethanolate, barium tertio-butanolate, barium nonylphenate, barium acetylacetonate, strontium acetylacetonate, barium dibenzoylmethane, strontium dibenzoylmethane, barium thenoyltrifluoro-acetonate, strontium thenoyltrifluoro-acetonate, barium benzoyltrifluoro-acetonate, strontium benzolytrifluoro-acetonate, barium benzoyl-acetonate, strontium benzoyl-acetonate, barium 1, 1-diphenylethylene, strontium 1, 1-diphenylethylene, barium 1,2-acenaphthylene, strontium 1,2-acenaphthylene, barium tetraphenyl-butane, strontium tetraphenyl-butane, barium alpha-methyl-styrene, strontium alpha-methyl-styrene, diphenyl-barium, diphenyl-strontium, bis-cyclopentadienyl-barium, bis-cyclopentadienyl-strontium, barium triphenylsilyl, strontium triphenylsilyl, phenyl-barium iodide, methyl-strontium iodide, barium-benzophenone, strontium-benzophenone, barium-cinnamone, strontium-cinnamone, barium-naphthalene, strontium-naphthalene, barium-anthracene, strontium-anthracene, barium chrysene and strontium-chrysene;
- and (b.sub.2) an organometallic compound of aluminum or zinc selected from the group consisting of diethyl zinc, triethyl aluminum, tri-isobutyl aluminum, diethyl aluminum chloride, ethyl aluminum dichloride, ethyl aluminum sesquichloride, methyl aluminum sesquichloride, diethyl aluminum hydride and diisobutyl aluminum hydride;
- said components being present in such quantities that the ratios are within the following limits:
- ##EQU4##
The process according to claim 10 wherein 8 cocatalyst system is preformed and added to the reaction medium at the same time as the organo-lithium initiator at the start of the reaction.
Dependencies are inferred from the claim text.