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US 5,296,574 AGranted
Method of synthesis of block copolymers of vinyl aromatic hydrocarbons and polydimethylsiloxane
AssigneeShell Oil Company
InventorRonald J. Hoxmeier
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AssigneeShell Oil Company
InventorRonald J. Hoxmeier
Estimating the term…
A method for producing, in the presence of both monomers, a block copolymer of a polymer block of a vinyl aromatic hydrocarbon (and/or a conjugated diene) and a block of polydimethysiloxane which comprises adding a vinyl aromatic hydrocarbon, an organo alkali metal promoter, hexamethylcyclotrisiloxane and a polar promoter to a solvent (or to the styrene if no solvent is to be used) at a temperature of 0.degree. to 60.degree. C., allowing the polymerization of the vinyl aromatic hydrocarbon to proceed until the color of the vinyl aromatic hydrocarbon - Li.sup.+ species which is initially produced fades, then raising the temperature to 60.degree. to 120.degree. C. wherein the hexamethylcyclotrisiloxane polymerizes at the end of the polystyrene polymer blocks and then terminating the polymerization.
A method for producing, in the presence of both monomers, a block copolymer of a first polymer block of anionic polymerization monomer(s) selected from the group consisting of vinyl aromatic hydrocarbons, conjugated dienes and mixtures thereof, and a second polymer block of polydimethysiloxane which comprises adding the anionic polymerization monomer(s), an organo alkali metal promoter, hexamethylcyclotrisiloxane and a polar promoter to a solvent at a temperature of 0.degree. to 60.degree. C., allowing the polymerization of the anionic polymerization monomer(s) to proceed until the color of the anionic polymerization monomer(s) - Li.sup.+ spicies which is initially produced fades, then raising the temperature to 60.degree. to 120.degree. C. wherein the hexamethyl-cyclotrisiloxane polymerizes at the end of the first polymer block and then terminating the polymerization.
A solventless method for producing, in the presence of both monomers, a block copolymer of a polymer block of monomers selected from the group consisting of vinyl aromatic hydrocarbons, conjugated dienes and mixtures thereof, and a block of polydimethysiloxane which comprises adding hexamethylcyclotrisiloxane, an organo alkali metal promoter, optionally, a conjugated diene and a polar promoter to the vinyl aromatic hydrocarbon at a temperature of 0.degree. to 25.degree. C. wherein the vinyl aromatic hydrocarbon serves as a solvent for the other components, allowing the polymerization of the vinyl aromatic hydrocarbon to proceed until the color of the vinyl aromatic hydrocarbon - Li.sup.+ species which is initially produced fades wherein the heat of the reaction of the vinyl aromatic hydrocarbon polymerization melts the hexamethylcyclotrisiloxane which then serves as a solvent for the polyvinyl aromatic hydrocarbon produced, raising the temperature to 65.degree. to 120.degree. C. wherein the hexamethylcyclotrisiloxane polymerizes at the ends of the polyvinyl aromatic hydrocarbon polymer blocks and terminating the polymerization.
Dependencies are inferred from the claim text.