Phillips Petroleum Company

William J Trepka

George A Moczygemba

Ralph C Farrar, Jr

Nathan E Stacy

Ralph C Farrar

Craig Donald DePorter

Larry L Nash

Charles M Selman

Nancy R Knight

Sidney Schiff

John R Bohannan

Richard J Sonnenfeld

Luis E Reyes

Tad L Olson

Alvin C Rothlisberger

Craig D Deporter

A method for preparing tapered block copolymers which are particularly useful for blend components in blends with polymers of styrene. In the first embodiment of this invention the copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent; to produce a polymodal tapered block copolymer. In a second embodiment of the invention tapered block copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjugated diene monomers; and (5) a coupling agent; to produce a polymodal tapered block copolymer. The invention copolymers and blends of the invention copolymers with polymers of styrene are particularly useful for applications such as packaging and food or drink containers which require transparency, low blueness, colorlessness, good impact strength and ductility.

Tapered block copolymers of monovinylarenes and conjugated dienes

Tapered block copolymers of monivinylarenes and conjugated dienes

A method for preparing resinous polymodal monovinylarene-conjugated diene block copolymers and polymers produced thereby are provided. The method comprises sequentially contacting under polymerization conditions:

Block copolymers of monovinylarenes and conjugated dienes and

A method for preparing blends of a copolymer in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomer in the presence of a randomizer; (2) an initiator and monovinylaromatic monomer; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjuated diene monomers; (5) conjugated diene monomer; and (6) a coupling agent; and the polymodal tapered block copolymers prepared thereby. The copolymers are particularly useful neat or in blends for applications such as packaging and food or drink containers which require transparency and good environmental stress crack resistance.

Blends of copolymers of monovinylarenes and conjugated dienes containing

A method for preparing tapered block copolymers which are particularly useful for blend components in blends with polymers of styrene. In the first embodiment of this invention the copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent; to produce a polymodal tapered block copolymer. In a second embodiment of the Invention tapered block copolymers are prepared in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and monovinylaromatic monomers; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjugated diene monomers; and (5) a coupling agent; to produce a polymodal tapered block copolymer. The invention copolymers and blends of the invention copolymers with polymers of styrene are particularly useful for applications such as packaging and food or drink containers which require transparency, low blueness, colorlessness, good impact strength and ductility.

A process for stabilizing polymers is provided comprising:

Method for stabilizing monovinylarene/conjugated diene copolymers and a

A method for preparing tapered block copolymers in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomer in the presence of a randomizer; (2) an initiator and monovinylaromatic monomer; (3) a mixture of monovinylaromatic and conjugated diene monomers; (4) a mixture of monovinylaromatic and conjugated diene monomers; (5) conjugated diene monomer; and (6) a coupling agent; and the polymodal tapered block copolymers prepared thereby. The copolymers are particularly useful neat or in blends for applications such as packaging and food or drink containers which require transparency and good environmental stress crack resistance.

Block copolymers of monovinylarenes and conjugated dienes containing two

A block copolymer comprising about 5 weight percent to about 95 weight percent monovinylarene monomer, about 95 to about 5 weight percent butadiene, and an effective amount of a thermal stabilizing agent selected from the group consisting of ascorbic acid, citric acid, disodium citrate, and mixtures thereof is provided. A process for stabilizing conjugated diene/monovinylarene block copolymer and articles prepared from such copolymers are also provided.

Conjugated diene/monovinylarene copolymers and preparation thereof

A method for preparing tapered block copolymers in a polymerization process by charging an initiator and monomers sequentially with one or more charges of first one of the monomers, then with a mixture of the two monomers, and then with one or more charges of the second monomer alternating with one or more charges of the first monomer with subsequent coupling to produce a polymodal tapered block copolymer. Suitable monomers include conjugated dienes and monovinylaromatic compounds. The copolymers are suitable for use in injection and blow molding equipment; the copolymers are particularly useful for shrink films, containers, tubes, fibers and other packaging applications.

Tapered block monovinyl aromatic/conjugated diene copolymer

A method for preparing resinous copolymers by sequential charge copolymerization of at least two charges, at least one being a conjugated diene and at least one being a monovinylarene; followed by a charge of a polyfunctional coupling agent; and the final charge being an essentially difunctional coupling agent. The copolymer made by this method and articles made from this copolymer are also provided.

Sequential coupling in formation of resinous block copolymers

A method for preparing tapered block copolymers in a polymerization process by sequentially charging: (1) an initiator and monovinylaromatic monomers in the presence of a randomizer; (2) an initiator and a mixture of monovinylaromatic and conjugated diene monomers; (3) an initiator and a mixture of monovinylaromatic and conjugated diene monomers; and (4) a coupling agent to produce a polymodal tapered block copolymer. The copolymers are particularly useful for packaging applications which require good environmental stress crack resistance.

Tapered block copolymers of conjugated dienes and monovinylarenes

A method for preparing tapered block copolymers in a polymerization process by charging an initiator and monomers sequentially with one or more charges of first one of the monomers, then with a mixture of the two monomers, and then with one or more charges of the first monomer to produce a polymodal tapered block copolymer. Suitable monomers include conjugated dienes and monovinylaromatic compounds. The copolymers are particularly useful for applications requiring environmental stress crack resistance.

Tapered block styrene/butadiene copolymers

A method for preparing tapered block copolymers in a polymerization process by charging an initiator and monomers sequentially with one or more charges of first one of the monomers, then with a mixture of the two monomers, and then with one or more charges of the second monomer alternating with one or more charges of the first monomer with subsequent coupling, to produce a polymodal tapered block copolymer. Suitable monomers include conjugated dienes and monovinylaromatic compounds. The copolymers are suitable for use in injection and blow molding equipment; the copolymers are particularly useful for shrink films, containers, tubes, fibers and other packaging applications.

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Bartlesville, OK, United States of America

William J Trepka