Rubber modified styrenic copolymers and their use in forming oriented articles
An oriented, i.e. uniaxial or biaxial, thermoplastic article, e.g. extruded sheet, blown film, and cast film, comprising a first component comprising a continuous phase and a dispersed phase, where A) the continuous phase contains a polymer composition resulting from the polymerization of a monomer mixture containing a styrenic monomer and an alkyl (meth)acrylate monomer in the presence of the dispersed phase; and B) the dispersed phase contains one or more block copolymer selected from diblock and triblock copolymers of styrene-butadiene, styrene-butadiene-styrene, styrene-isoprene, styrene-isoprene-styrene, partially hydrogenated styrene-isoprene-styrene, wherein the oriented thermoplastic article has a thickness ranging from 0.02 mm to 0.50 mm, a tensile strength ranging from 15 Mpa to 70 Mpa as measured by ASTM D 882, an impact value ranging between 0.05 ft. lb/mil to 1.0 ft. lb/mil as measured by ASTM D 3763, and a Haze value less than 10% as measured by ASTM D 1003.
1 . An oriented thermoplastic article, comprising a first component comprising a continuous phase and a dispersed phase, wherein:
A) the continuous phase comprises a polymer composition resulting from the polymerization of a monomer mixture comprising (i) from about 25 parts by weight to 75 parts by weight of a styrenic monomer and (ii) from about 25 parts by weight to 75 parts by weight of an alkyl (meth)acrylate monomer, wherein the alkyl group is a C 1 to C 12 linear, branched or cyclic alkyl group, in the presence of the dispersed phase; and
B) the dispersed phase comprises from about 2 parts by weight to about 50 parts by weight of one or more block copolymers selected from the group consisting of diblock and triblock copolymers of styrene-butadiene, styrene-butadiene-styrene, styrene-isoprene, styrene-isoprene-styrene, partially hydrogenated styrene-isoprene-styrene, for a total of 100 parts by weight of the combination of A) and B), and
wherein said oriented thermoplastic article has a thickness ranging from about 0.02 mm to about 0.50 mm, a tensile strength ranging from about 15 Mpa to about 70 Mpa as measured by ASTM D 882, an impact value ranging from about 0.05 ft. lb/mil to about 1.0 ft. lb/mil as measured by ASTM D 3763, and a Haze value less than 10% as measured by ASTM D 1003.
2 . The oriented thermoplastic article of claim 1 wherein said oriented thermoplastic article is an uniaxially oriented thermoplastic article.
3 . The oriented thermoplastic article of claim 2 wherein said uniaxially oriented thermoplastic article is selected from the group consisting of extruded sheet, blown film, and cast film.
4 . The oriented thermoplastic article of claim 1 wherein said oriented thermoplastic article is a biaxially oriented thermoplastic article.
5 . The oriented thermoplastic article of claim 4 wherein said biaxially oriented thermoplastic article is selected from the group consisting of extruded sheet, blown film, and cast film.
6 . The oriented thermoplastic article of claim 1 wherein the dispersed phase B) is present as discrete particles dispersed within the continuous phase A).
7 . The oriented thermoplastic article of claim 1 wherein the volume average particle size of the dispersed phase B) is from about 0.1 μm to about 2 μm.
8 . The oriented thermoplastic article of claim 1 wherein the difference between the refractive index of the continuous phase A) and the dispersed phase B) is not more than 0.01.
9 . The oriented thermoplastic article of claim 1 wherein the styrenic monomer is selected from the group consisting of styrene, p-methyl styrene, tertiary butyl styrene, dimethyl styrene, nuclear brominated or chlorinated derivatives thereof and combinations thereof.
10 . The oriented thermoplastic article of claim 1 wherein the alkyl (meth)acrylate monomer comprises methylmethacrylate and optionally butyl acrylate.
11 . The oriented thermoplastic article of claim 1 wherein the block copolymer has a weight average molecular weight of not less than about 75,000.
12 . The oriented thermoplastic article of claim 1 wherein the block copolymer is a linear or radial block copolymer.
13 . The oriented thermoplastic article of claim 1 wherein the block copolymer is a triblock styrene-butadiene-styrene or styrene-isoprene-styrene copolymer having a weight average molecular weight of from about 175,000 to about 275,000.
14 . The oriented thermoplastic article of claim 1 wherein at least some of the polymers in A) are grafted onto the block copolymer in B).
15 . The oriented thermoplastic article of claim 1 further comprising a printed layer over at least a portion of a surface of the thermoplastic sheet.
16 . The oriented thermoplastic article of claim 1 wherein the monomer mixture further comprises a chain transfer agent.
17 . A multi-layer structure comprising at least two layers and wherein at least one layer of said multi-layer structure is comprised of the oriented thermoplastic article of claim 1 .
18 . A multi-layer structure of claim 17 wherein at least the other layer of said multi-layer structure is comprised of a rubber modified polystyrene composition.
19 . A multi-layer structure of claim 17 wherein at least the other layer of said multi-layer structure is comprised of a polyethylene composition.
20 . A multi-layer structure of claim 17 wherein at least the other layer of said multi-layer structure is comprised of an ethylvinyl acetate composition.
21 . A process for preparing an oriented thermoplastic article, comprising:
forming a thermoplastic composition comprising a continuous phase and a dispersed phase, wherein
A) the continuous phase comprises a polymer composition resulting from the polymerization of a monomer mixture comprising (i) from about 25 to 75 parts by weight of a styrenic monomer and (ii) from about 25 to 75 parts by weight of an alkyl (meth)acrylate monomer, wherein the alkyl group is a C 1 to C 12 linear, branched or cyclic alkyl group, in the presence of the dispersed phase; and
B) the dispersed phase comprises from about 2 to about 50 parts by weight of one or more block copolymers selected from the group consisting of diblock and triblock copolymers of styrene-butadiene, styrene-butadiene-styrene, styrene-isoprene, styrene-isoprene-styrene, partially hydrogenated styrene-isoprene-styrene, for a total of 100 parts by weight of the combination of A) and B);
maintaining said thermoplastic composition in a molten state while mixing said composition; and
forming said oriented thermoplastic article; and
wherein said oriented thermoplastic article has a thickness ranging from about 0.02 mm to about 0.50 mm, a tensile strength ranging from about 15 Mpa to about 70 Mpa as measured by ASTM D 882, an impact value ranging from about 0.05 ft. lb/mil to about 1.0 ft. lb/mil as measured by ASTM D 3763, and a Haze value less than 10% as measured by ASTM D 1003.
22 . The process of claim 21 wherein said oriented thermoplastic article is an uniaxially oriented thermoplastic article.
23 . The process of claim 22 wherein said uniaxially oriented thermoplastic article is selected from the group consisting of extruded sheet, blown film, and cast film.
24 . The process of claim 21 wherein said oriented thermoplastic article is an biaxially oriented thermoplastic article.
25 . The process of claim 24 wherein said biaxially oriented thermoplastic article is selected from the group consisting of extruded sheet, blown film, and cast film.
26 . The process of claim 21 wherein the dispersed phase B) is present as discrete particles dispersed within the continuous phase A).
27 . The process of claim 21 wherein the volume average particle size of the dispersed phase B) is from about 0.1 μm to about 2 μm.
28 . The process of claim 21 wherein the difference between the refractive index of the continuous phase A) and the dispersed phase B) is not more than 0.01.
29 . The process of claim 21 wherein the styrenic monomer is selected from the group consisting of styrene, p-methyl styrene, tertiary butyl styrene, dimethyl styrene, nuclear brominated or chlorinated derivatives thereof and combinations thereof.
30 . The process of claim 21 wherein the alkyl (meth)acrylate monomer comprises methylmethacrylate and optionally butyl acrylate.
31 . The process of claim 21 wherein the block copolymer has a weight average molecular weight of not less than about 75,000.
32 . The process of claim 21 wherein the block copolymer is a linear or radial block copolymer.
33 . The process of claim 21 wherein the block copolymer is a triblock styrene-butadiene-styrene or styrene-isoprene-styrene copolymer having a weight average molecular weight of from about 175,000 to about 275,000.
34 . The process of claim 21 wherein at least some of the polymers in A) are grafted onto the block copolymer in B).
35 . The process of claim 21 wherein the monomer mixture further comprises a chain transfer agent.
36 . A thermoplastic composition for an oriented thermoplastic article comprising a first component comprising a continuous phase and a dispersed phase, where:
A) the continuous phase comprises a polymer composition resulting from the polymerization of a monomer mixture comprising (i) from about 25 parts by weight to 75 parts by weight of a styrenic monomer and (ii) from about 25 parts by weight to 75 parts by weight of an alkyl (meth)acrylate monomer, wherein the alkyl group is a C 1 to C 12 linear, branched or cyclic alkyl group, in the presence of the dispersed phase; and
B) the dispersed phase comprises from about 2 parts by weight to about 50 parts by weight of one or more block copolymers selected from the group consisting of diblock and triblock copolymers of styrene-butadiene, styrene-butadiene-styrene, styrene-isoprene, styrene-isoprene-styrene, partially hydrogenated styrene-isoprene-styrene, for a total of 100 parts by weight of the combination of A) and B), and
wherein said first component ranges in an amount of about 0.1 to about 100% by weight, based on the weight of the thermoplastic composition.
37 . A thermoplastic composition of claim 36 , wherein said composition further comprises about 70% by weight of said first component, and about 30% by weight of a rubber modified polystyrene.
38 . A thermoplastic composition of claim 36 , wherein said composition further comprises about 70% by weight of said first component, about 15% by weight of a rubber modified polystyrene, and about 15% by weight of a tie component.
39 . A thermoplastic composition of claim 36 , wherein said composition further comprises about 40% by weight of said first component, about 40% by weight of a rubber modified polystyrene, and about 20% by weight of a tie component.
40 . A thermoplastic composition of claim 36 , wherein said composition further comprises about 70% by weight of said first component, and about 30% by weight a tie component.
41 . A thermoplastic composition of claim 36 wherein said thermoplastic article is an uniaxially oriented thermoplastic article.
42 . A thermoplastic composition of claim 41 wherein said uniaxially oriented thermoplastic article is selected from the group consisting of extruded sheet, blown film, and cast film.
43 . A thermoplastic composition of claim 41 wherein said thermoplastic article is a biaxially oriented thermoplastic article.
44 . A thermoplastic composition of claim 43 wherein said biaxially oriented thermoplastic article is selected from the group consisting of extruded sheet, blown film, and cast film.