# US 8,568,869 B2 · Optical bodies including rough strippable boundary layers and asymmetric surface structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,568,869 B2 - Document ID: US8568869B2 - Status: Granted - Kind: B2 - Application number: 11/398,338 - Filed: 2006-04-05 - Published: 2006-10-12 - Granted: 2013-10-29 - Earliest claimed: 2005-04-06 - Assignees: 3M Innovative Properties Company - Applicants: Timothy J. Hebrink; Carl A. Stover; Martin E. Denker; Jeffery N. Jackson; Kristopher J. Derks; Michael F. Weber; Anna A. Kobilansky; Joan M. Strobel; Barry S. Rosell; John P. Purcell; Kevin M. Hamer; Robert D. Taylor; William B. Black; Richard J. Thompson; Gregory L. Bluem - Inventors: Timothy J. Hebrink; Carl A. Stover; Martin E. Denker; Jeffery N. Jackson; Kristopher J. Derks; Michael F. Weber; Anna A. Kobilansky; Joan M. Strobel; Barry S. Rosell; John P. Purcell; Kevin M. Hamer; Robert D. Taylor; William B. Black; Richard J. Thompson; Gregory L. Bluem - Web page: https://patentgrep.com/patent/US8568869B2 ## CPC - B29D 11/00788: {Producing optical films} - B32B 3/26: characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids {(foam layer B32B5/18; layer of synthetic resin characterised by fillers that create voids or cavities B32B27/205); characterised by an apertured layer} - B32B 7/06: permitting easy separation - G02B 1/12: by surface treatment, e.g. by irradiation - G02B 5/0221: {the surface having an irregular structure (G02B5/0226 takes precedence)} - G02B 5/0257: {creating an anisotropic diffusion characteristic, i.e. distributing output differently in two perpendicular axes} - G02B 5/0268: {characterized by the fabrication or manufacturing method} - G02B 5/0278: {used in transmission} - G02B 5/305: {including organic materials, e.g. polymeric layers} - G02B 27/283: {used for beam splitting or combining} - Y10T 428/24355: Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.] - Y10T 428/24372: Particulate matter - Y10T 428/25: Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles - Y10T 428/254: Polymeric or resinous material - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Optical bodies are disclosed that include an optical film and at least one rough strippable skin layer. The at least one rough strippable skin layer can include a continuous phase and a disperse phase. In some embodiments, the at least one rough strippable skin layer can include a first polymer, a second polymer different from the first polymer and an additional material that is substantially immiscible in at least one of the first and second polymers. In some exemplary embodiments, a surface of the at least one rough strippable skin layer adjacent to the optical film comprises a plurality of protrusions and the adjacent surface of the optical film comprises a plurality of asymmetric depressions substantially corresponding to said plurality of protrusions. Methods of making such exemplary optical bodies are also disclosed. ## Claims ### Claim 1 An optical body, comprising: a first optical film, a second optical film and at least one rough strippable boundary layer disposed between the first and second optical films adjacent to a surface of at least one of the first and second optical films, wherein at least one of the first and second optical films comprises a polymeric multilayer optical film; wherein a surface of the rough strippable boundary layer disposed adjacent to an optical film comprises a first plurality of surface structures with a first shape and the adjacent surface of the optical film comprises a second plurality of asymmetric surface structures substantially corresponding to said first plurality of surface structures, wherein the asymmetrical surface structures have a second shape comprising at least one dimension different from a corresponding dimension of the first shape. ### Claim 2 (depends on 1) The optical body of claim 1, wherein the optical film having asymmetric surface structures is characterized by a haze of at least about 10%. ### Claim 3 (depends on 1) The optical body of claim 1, wherein the rough strippable boundary layer comprises a continuous phase and a disperse phase. ### Claim 4 (depends on 3) The optical body of claim 3, wherein the continuous phase comprises at least one of: a polypropylene, a polyester, a linear low density polyethylene, a nylon and copolymers thereof, syndiotactic polypropylene, linear low density polyethylene and a random copolymer of propylene and ethylene. ### Claim 5 (depends on 3) The optical body of claim 3, wherein the disperse phase comprises at least one of: styrene acrylonitrile, medium density polyethylene, modified polyethylene, polycarbonate and copolyester blend, C-caprolactone polymer, propylene random copolymer, poly(ethylene octene) copolymer, anti-static polymer, high density polyethylene, linear low density polyethylene, polymethyl methacrylate, and inorganic materials. ### Claim 6 (depends on 3) The optical body of claim 3, wherein the disperse phase comprises a plurality of beads. ### Claim 7 (depends on 1) The optical body of claim 1, wherein at least one rough strippable boundary layer further comprises a nucleating agent or a coloring agent. ### Claim 8 (depends on 1) The optical body of claim 1, wherein at least one of the optical films is selected from the group consisting of: a multilayer polarizer, a multilayer reflector, an optical film having a continuous and a disperse phase, a layer comprising styrene acrylonitrile, a layer comprising polycarbonate, a layer comprising polyethylene terephthalate, a layer comprising a cycloaliphatic polyester/polycarbonate and any number or combination thereof. ### Claim 9 (depends on 1) The optical body of claim 1, wherein at least one of the optical films comprises at least one underskin layer. ### Claim 10 (depends on 9) The optical body of claim 9, wherein the underskin layer comprises styrene acrylonitrile, polycarbonate, polyethylene terephthalate or cycloaliphatic polyester/polycarbonate. ### Claim 11 (depends on 9) The optical body of claim 9, wherein the underskin layer comprises a first material and a second material substantially immiscible in the first material, said second material being polymeric or inorganic. ### Claim 12 (depends on 1) The optical body of claim 1, said optical body being substantially transparent. ### Claim 13 (depends on 1) The optical body of claim 1, wherein the optical body comprises a birefringent material. ### Claim 14 (depends on 1) The optical body of claim 1, further comprising at least one smooth strippable layer. ### Claim 15 (depends on 1) The optical body of claim 1, wherein the at least one rough strippable boundary layer further comprises voids. ### Claim 16 (depends on 1) The optical body of claim 1, wherein the adhesion between the surface of the rough strippable boundary layer and the surface of the optical film is characterized by a peel force of about 2 grams/inch to about 120 grams/inch such that the rough strippable boundary layer is cleanly removable from the optical film. ### Claim 17 An optical body, comprising: a first optical film, a second optical film and at least one rough strippable boundary layer disposed between the first and second optical films adjacent to a surface of at least one of the first and second optical films, wherein at least one of the first and second optical films comprises a polymeric multilayer optical film; wherein a surface of the rough strippable boundary layer disposed adjacent to an optical film comprises a first plurality of surface structures with a first major dimension and a first minor dimension, and the adjacent surface of the optical film comprises a second plurality of asymmetric surface structures substantially corresponding to said first plurality of surface structures, wherein the asymmetric surface structures have a second major dimension and a second minor dimension, wherein at least one of the second major dimension and the second minor dimension are different from at least one of the first major dimension and the first minor dimension of the corresponding first surface structures, and wherein the second major dimension is substantially collinear with a first axis of the optical body and the second minor dimension is substantially collinear with a second axis of the optical body, and further wherein an average ratio of the second major dimension to the second minor dimension is at least about 1.5. ### Claim 18 (depends on 17) The optical body of claim 17, wherein the asymmetric surface structures have an average major dimension from about 4 microns to about 40 microns. ### Claim 19 (depends on 17) The optical body of claim 17, wherein the asymmetric surface structures have an average depth from about 0.2 microns to about 4 microns. ### Claim 20 (depends on 17) The optical body of claim 17, wherein the asymmetric surface structures have an average minor dimension from about 0.2 microns to about 5 microns.