ABS type resins having disperse particles of a rubber exhibiting a high solution viscosity and a method for its preparation

Claim 1

A rubber-reinforced copolymer comprising a copolymer matrix derived from one or more monovinylidene aromatic compounds, one or more unsaturated nitrile compounds and, optionally, other comonomers having at least 6 weight percent of a rubber based on the total weight of the rubber and copolymer, which exhibits a viscosity, as a 5 weight percent solution in styrene, of at least 120 centipoise dispersed as discrete particles therethrough, said rubber particles containing occlusions of grafted and/or ungrafted polymer and having a volume average particle size of less than 1.5 micrometer.

Claim 8

A method for preparing a rubber-reinforced copolymer of a monovinylidene aromatic, an unsaturated nitrile and, optionally, one or more other comonomers having discrete particles of. a rubber which exhibits a high solution viscosity dispersed throughout the copolymer matrix, the method comprising the steps of mass polymerizing a solution of one or more monovinylidene aromatic compounds, one or more unsaturated nitrile compounds and at least 5 percent of a rubber which exhibits a viscosity, as a 5 weight percent solution in styrene, of at least 120 centipoise, said weight percent being based on the total weight of monomers and rubber, at conditions to form a copolymer of the monovinylidene aromatic(s), unsaturated nitrile(s) and other optional comonomers having a sufficiently high molecular weight such that, upon phase inversion of the mass polymerization mixture and subsequent sizing of the rubber, the rubber becomes dispersed at a volume average particle size of 1.5 micron or less without excessively agitating the polymerization mixture and, after phase inversion and sizing of the rubber particles, continuing polymerization to convert the desired amounts of monomer to polymer.

Claim 9

A method for preparing a rubber-reinforced copolymer of a monovinylidene aromatic, an unsaturated nitrile and, optionally, one or more other comonomers having discrete particles of. a rubber which exhibits a high solution viscosity dispersed throughout the copolymer matrix, the method comprising the steps of mass polymerizing a solution of one or more monovinylidene aromatic compounds, one or more unsaturated nitrile compounds and at least 5 percent of a rubber which exhibits a viscosity, as a 5 weight percent solution in styrene, of at least 120 centipoise, said weight percent being based on the total weight of monomers and rubber, at conditions to form a copolymer of the monovinylidene aromatic(s), unsaturated nitrile(s) and other optional comonomers having a sufficiently high molecular weight such that, upon phase inversion of the mass polymerization mixture and subsequent sizing of the rubber, the rubber becomes dispersed at a volume average particle size of 1.5 micron or less without excessively agitating the polymerization mixture and, after phase inversion and sizing of the rubber particles, continuing polymerization to convert the desired amounts of monomer to polymer.