Mass polymerized rubber-modified monovinylidene aromatic copolymer composition
AssigneeDow Global Technologies LLC
InventorsDominique Maes, Adrianus Ruiter, Gilbert Bouquet, Tim Pope, Rony Vanspeybroeck, Kees-Jeen Duin
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Abstract
Disclosed is a mass polymerized rubber-modified monovinylidene aromatic copolymer composition with an excellent balance of physical and mechanical properties especially low temperature impact, and methods for preparing such a composition.
Claims22
A mass polymerized rubber-modified monovinylidene aromatic copolymer composition comprising:
- (i) a continuous matrix phase comprising a copolymer of a monovinylidene aromatic monomer and an ethylenically unsaturated nitrile monomer and (ii) a rubber component dispersed as discrete rubber particles in the matrix comprising
- (a) a polybutadiene rubber with a 5 weight percent solution viscosity in styrene at 25° C. of between 15 to 120 cP and
- (b) a styrene and butadiene block copolymer rubber
- wherein the rubber component has a polybutadiene content (PBDc) equal to or greater than about 14 weight percent based on the weight of the copolymer composition and the matrix copolymer has a weight average molecular weight (Mw Matrix) represented by the formula:
- (Mw Matrix)≧510−22*PBDc.
A mass polymerized rubber-modified monovinylidene aromatic copolymer composition having a notched Charpy impact strength equal to or greater than 18 kJ/m2 at a temperature of −30° C.
A method for preparing a mass polymerized rubber-modified monovinylidene aromatic copolymer composition comprising the steps of:
- (i) polymerizing by bulk, mass-solution or mass-suspension polymerization techniques in the presence of a dissolved rubber component a monovinylidene aromatic monomer and an ethylenically unsaturated nitrile monomer, optionally in the presence of an inert solvent, to the desired degree of conversion and
- (ii) subjecting the resultant mixture to conditions sufficient to remove any unreacted monomers and to cross-link the rubber,
- wherein the polymerized monovinylidene aromatic monomer and the ethylenically unsaturated nitrile monomer comprise a matrix copolymer and
- wherein the rubber component
- (a) comprises a polybutadiene rubber with a 5 weight percent solution viscosity in styrene at 25° C. of between 15 to 120 cP and a styrene and butadiene block copolymer rubber and
- (b) has a polybutadiene content (PBDc) equal to or greater than about 14 weight percent based on the weight of the copolymer composition
- and the matrix copolymer has a weight average molecular weight (Mw Matrix) represented by the formula:
- (Mw Matrix)≧510−22*PBDc
A method for producing a molded or extruded article of a mass polymerized rubber-modified monovinylidene aromatic copolymer composition comprising the steps of:
- (A) preparing a mass polymerized rubber-modified monovinylidene aromatic copolymer composition comprising
- (i) a continuous matrix phase comprising a copolymer of a monovinylidene aromatic monomer and an ethylenically unsaturated nitrile monomer and
- (ii) a rubber component dispersed as discrete rubber particles in the matrix comprising
- (a) a polybutadiene rubber with a 5 weight percent solution viscosity in styrene at 25° C. of between 15 to 120 cP and
- (b) a styrene and butadiene block copolymer
- wherein the rubber component has a polybutadiene content (PBDc) equal to or greater than about 14 weight percent based on the weight of the copolymer composition and the matrix copolymer has a weight average molecular weight (Mw Matrix) represented by the formula:
- (Mw Matrix)≧510−22*PBDc,
- and
- (B) molding or extruding said rubber-modified monovinylidene aromatic copolymer composition into a molded or extruded article having.
Dependencies are inferred from the claim text.