US4442273A — Process and apparatus for continuous polymerizati…

Claim 1

Independent Claim 213 words

The process for continuous anionic solution polymerization of a monovinyl aromatic monomer to produce a polymer having a low weight average molecular weight to number average molecular weight ratio, comprising: continuously feeding a solution of a monovinyl aromatic monomer in an inert solvent, and a hydrocarbyllithium initiator in an inert solvent, to form a mixture in the bottom zone of a sealed, cylindrical, pressurized, vertical reactor having a bottom zone, a top zone, and a plurality of intermediate zones, each said zone separated from an adjacent zone by separation plates having a central aperture therethrough, and stirring means carried by a central shaft passing through said apertures with an annular space provided between the shaft and each said separation plate; continuously passing said mixture from the bottom zone to successive zones through the annular space between the shaft and each said separation plate, said annular space being dimensioned so as to provide a high interstage velocity relative to superficial velocity and pressure differential of less than one pound per square inch between said successive zones; stirring said mixture while passing the same through each zone; and cooling the reaction if necessary by means of a zoned-jacket or pumparound loop for each zone; and continuously removing a solution of polymer from the top zone.

Claim 2

Dependent Claim 213 words

The process for continuous anionic solution polymerization of a monovinyl aromatic monomer to produce a polymer having a low weight average molecular weight to number average molecular weight ratio, comprising: continuously feeding a solution of a monovinyl aromatic monomer in an inert solvent, and a hydrocarbyllithium initiator in an inert solvent, to form a mixture in the bottom zone of a sealed, cylindrical, pressurized, vertical reactor having a bottom zone, a top zone, and a plurality of intermediate zones, each said zone separated from an adjacent zone by separation plates having a central aperture therethrough, and stirring means carried by a central shaft passing through said apertures with an annular space provided between the shaft and each said separation plate; continuously passing said mixture from the bottom zone to successive zones through the annular space between the shaft and each said separation plate, said annular space being dimensioned so as to provide a high interstage velocity relative to superficial velocity and pressure differential of less than one pound per square inch between said successive zones; stirring said mixture while passing the same through each zone; and cooling the reaction if necessary by means of a zoned-jacket or pumparound loop for each zone; and continuously removing a solution of polymer from the top zone.

Claim 3

Dependent Claim 24 words

The process as defined in claim 1 wherein said monovinyl aromatic monomer is selected from the group consisting of styrene and alkyl substituted styrenes.

Claim 4

Dependent Claim 14 words

The process as defined in claim 2 wherein said monovinyl aromatic monomer is styrene.

Claim 5

Dependent Claim 13 words

The process as defined in claim 3 wherein said hydrocarbyllithium initiator is sec-butyllithium.

Claim 6

Dependent Claim 30 words

The process as defined in claim 1 wherein the monovinyl aromatic monomer in inert solvent is preheated to a temperature of between 65°-100° C. for introduction into the bottom zone.

Claim 7

Dependent Claim 21 words

The process as defined in claim 1 wherein said mixture in the reactor is maintained at a temperature of 70°-100° C.

Claim 8

Dependent Claim 21 words

The process as defined in claim 1 wherein said mixture is continuously passed through at least eight zones within the reactor.

Claim 9

Dependent Claim 28 words

The process as defined in claim 1 wherein said inert solvent is selected from the group consisting of isopentane, pentane, cyclopentane, cyclohexane, benzene, toluene, xylene, and mixtures thereof.

Claim 10

Dependent Claim 196 words

The process for continuous anionic solution polymerization of styrene to produce polystyrene having a low weight average molecular weight to number average molecular ratio, comprising: continuously feeding a preheated solution of styrene in an inert solvent, and a hydrocarbyllithium initiator in an inert solvent, to form a mixture in the bottom zone of a sealed, cylindrical, pressurized, vertical reactor having a bottom zone, a top zone, and at least eight intermediate zones, each said zone separated from an adjacent zone by separation plates having a central aperture therethrough, and stirring means carried by a central shaft passing through said apertures with an annular space provided between the shaft and each said separation plate; continuously passing said mixture from the bottom zone to successive zones through the annular space between the shaft and each said separation plate, said annular space being dimensioned so as to provide a pressure differential of less than one pound per square inch between said successive zones: stirring said mixture while passing the same through each zone; maintaining said mixture at a temperature of between 70°-100° C. during passage through said zones; and continuously removing a solution of polystyrene from the top zone.

Claim 11

Dependent Claim 196 words

The process for continuous anionic solution polymerization of styrene to produce polystyrene having a low weight average molecular weight to number average molecular ratio, comprising: continuously feeding a preheated solution of styrene in an inert solvent, and a hydrocarbyllithium initiator in an inert solvent, to form a mixture in the bottom zone of a sealed, cylindrical, pressurized, vertical reactor having a bottom zone, a top zone, and at least eight intermediate zones, each said zone separated from an adjacent zone by separation plates having a central aperture therethrough, and stirring means carried by a central shaft passing through said apertures with an annular space provided between the shaft and each said separation plate; continuously passing said mixture from the bottom zone to successive zones through the annular space between the shaft and each said separation plate, said annular space being dimensioned so as to provide a pressure differential of less than one pound per square inch between said successive zones: stirring said mixture while passing the same through each zone; maintaining said mixture at a temperature of between 70°-100° C. during passage through said zones; and continuously removing a solution of polystyrene from the top zone.

Claim 12

Dependent Claim 19 words

The process as defined in claim 9 wherein said inert solvent is cyclohexane and said hydrocarbyllithium initiator is sec-butyllithium.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-04-10	1987-10-10	1988-04-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-04-10	1991-10-10	1992-04-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-04-10	1995-10-10	1996-04-10	$7700.00	Window Closed / Lapsed

Process and apparatus for continuous polymerization of a monovinyl aromatic monomer

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag