Film composites
OwnerAnthony B. Port, John P. A. Fairclough +2inventors
InventorsAnthony B. Port, John P. A. Fairclough, Anthony J. Ryan, Corrine L. O. Salou
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Abstract
An optically active film composite comprising a transparent substrate and at least one layer of a block copolymer blend comprising between 30:70 to 70:30 percent by volume of each component of the copolymer, the block copolymer forming lamellar microdomains of each polymeric component, which components have different refractive indices. The thickness of the lamellae may be controlled through selection of molecular weights of the components and by the addition of compatible homopolymers.
Claims15
An optically active layered composite comprising a substrate having thereon at least one layer of a block copolymer film comprising polymeric component “a” and polymeric component “b”, said polymeric components “a” & “b” being separated into lamellar microdomains of each polymeric component, which components have different refractive indices, with said components of the block copolymer present as a blend of both copolymer and its respective homopolymer, wherein polymeric component “a”, polymeric component “b”, diluent homopolymer “a” and diluent homopolymer “b” are selected such that:
- ( NaNb ) Nab < 0.5
- where Na is the number average decree of polymerisation of homopolymer “a”, Nb is the number average degree of polymerisation of homopolymer “b”, Nab is the number average degree of polymerisation of the block copolymer.
An optically active layered composite comprising a transparent polymeric substrate having thereon at least one layer of a-block copolymer film of polystyrene:
- butadiene, the styrene and butadiene components of the copolymer being separated into lamellar microdomains of each polymeric component, said components having different refractive indices, and being present as a blend of .both copolymer and its respective homopolymer wherein polymeric component “a”, polymeric component “b”, diluent homopolymer “a” and diluent homopolymer “b” are selected such that:” ( NaNb ) Nab < 0.2
- where Na is the number average degree of polymerisation of homopolymer “a”, Nb is the number average degree of polymerisation of homopolymer “b”, Nab is the number average degree of polymerisation of the block copolymer.
Dependencies are inferred from the claim text.