Process for continuous bulk copolymerization of vinyl monomers
AssigneeS. C. Johnson & Son, Inc.
InventorsArchie E. Hamielec, Grant P. Lawless, Harold H. Schultz
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Abstract
A process to bulk polymerize vinylic monomers to prepare low molecular weight polymers employing thermal initiation at reaction temperatures from 235.degree. C. to 310.degree. C. and residence times of at least 2 minutes in a continuous stirred reactor zone containing the molten resin mix.
Claims9
Bulk polymerization process for preparing low molecular weight vinylic polymers having a dispersion index less than about 2 and a number average molecular weight from about 1000 to 6000 comprising the steps of continuously:
- (a) charging a mixture of vinylic monomers into a continuous stirred reactor zone containing a molten resin mixture of unreacted vinylic monomers and said vinylic polymer product;
- (b) maintaining the molten resin mixture at a reaction temperature from about 235.degree. C. to 310.degree. C.;
- (c) maintaining a flow rate through said reaction zone sufficient (1) to provide a residence time of said charged vinylic monomer mixture in said reaction zone of at least about 2 minutes to provide a reaction product;
- and (2) to maintain a predetermined level of reaction mixture in said reaction zone;
- wherein said mixture of vinylic monomers comprises at least one monoalkenyl aromatic monomer and at least one acrylic monomer.
Low molecular weight vinylic polymers of at least one monoalkenyl aromatic monomer and at least one acrylic monomer having a dispersion index less than about 2 and a number average molecular weight from about 1000 to 6000 formed by the bulk polymerization process which comprises the steps of continuously:
- (a) charging a mixture of vinylic monomers into a continuous stirred reactor zone containing a molten resin mixture of unreacted vinylic monomers and said vinylic polymer product;
- (b) maintaining the molten resin mixture at a reaction temperature from about 235.degree. C. to 310.degree. C.;
- and
- (c) maintaining a flow rate through said reaction zone sufficient (1) to provide a residence time of said charged vinylic monomer mixture in said reaction zone of at least about 2 minutes to provide a reaction product;
- and (2) to maintain a predetermined level of reaction mixture in said reaction zone.
Dependencies are inferred from the claim text.