Abstract: A light diffusing optical construction is disclosed. The optical construction includes a symmetric optical diffuser that scatters light in a first direction with a first viewing angle AH and in a second direction orthogonal to the first direction with a second viewing angle AV, where AV is substantially equal to AH. The symmetric optical diffuser includes an optically transparent first layer and a plurality of randomly arranged optically transparent beads partially embedded in the first layer leaving portions of the beads exposed. The optical construction also includes a specular reflector that reflects light that is not scattered by the symmetric optical diffuser. The specular reflector has a first average reflectance Ro in the visible at zero incident angle and a second average reflectance R60 in the visible at 60 degree incident angle. Ro/R60 is at least about 1.5. The optical construction also includes a light absorbing layer that absorbs light that is not reflected by the specular reflector.

Abstract: Presently described are multilayer optical films, oriented polyester films, negatively birefringent copolyester polymers, fluorene monomers, and polyester polymers prepared from such fluorene monomers. In one embodiment, the multilayer optical film comprises at least one first birefringent optical layer; and at least one second optical layer having a lower birefringence than the first optical layer; wherein at least one of the optical layers comprises a negatively birefringent polyester polymer comprising a backbone and repeat units comprising at least one pendent aromatic group that is conformationally locked relative to the backbone.

Abstract: A reflective film includes interior layers that selectively reflect light by constructive or destructive interference, the layers extending from a first to a second zone of the film. The interior layers include a first set of layers composed of a first material and a second set of layers composed of a different second material. The first and second sets of layers are both birefringent in the first zone, but at least some of the layers have reduced birefringence in the second zone. The reduced birefringence produces a second reflective characteristic in the second zone that differs from a first reflective characteristic in the first zone, this difference not being substantially attributable to any thickness difference between the first and second zones. The film may also incorporate absorbing agents to assist in the manufacture or processing of the film.

Abstract: Described herein is a release material comprising: a blend comprising: releasing agent comprising a urethane polymer derived from a polyvinyl polymer containing active hydroxyl groups and an aliphatic isocyanate; and a carrier polymer, wherein more than 50% by weight of the carrier polymer is non-olefinic, and articles thereof.

Abstract: A retarder film provides a first light retardation and can be heat processed in one or more selected areas to provide a second light retardation in the selected area(s). The retarder film may have an absorption characteristic such that the heat processing can be carried out by selectively exposing the film to a suitable radiant beam. The retarder film is composed of a stack of contiguous ultrathin layers configured to provide an effective optical medium for visible light. Visible light propagates through the stack as an effective medium having effective refractive indices along principal x-, y-, and z-axes. At least some of the ultrathin layers possess intrinsic birefringence, and the effective indices of the stack are functions of the intrinsic refractive indices of the constituent ultrathin layers. The heat processing is carried out so that the ultrathin layer stack structural integrity is not substantially altered in the processed area(s).

Abstract: Multilayer optical film that can be used as a reflective polarizer or mirror is disclosed. The multilayer optical film comprises alternating optical layers of polyesters such as PET and PEN, copolymerized with 4,4?-biphenyl dicarboxylate. The multilayer optical film exhibits a high ratio of in-plane to out-of-plane birefringence.

Abstract: An optical stack (400) having a plurality of alternating polymeric layers (401, 402) is described. The alternating layers may be alternating birefringent (syndiotactic polystyrene, sPS) and isotropic (CoPENa) layers, or alternating positively and negatively birefringent layers. Birefringent layers are made using polymers which form optically symmetrical crystallites upon stretching of the polymer. The optical stack has a large refractive index difference in the x-direction (the stretching direction) and small refractive index differences in the y- and z-directions (the non-stretching directions). The optical stack can be made using standard film tentering methods and may be a multilayer reflective polarizer.

Abstract: The present invention relates to multilayer optical films and birefringent copolyester films. The birefringent copolyester optical layer or birefringent copolyester film comprises a major amount of naphthalate units, ethylene units, and a minor amount of branched or cyclic C4 to C10 alkyl units. Also described are certain copolyester polymeric materials further comprising subunits of a phthalate ionomer such as dimethyl sulfosodium isophthalate ionomer.

Abstract: A light diffusing optical construction is disclosed. The optical construction includes a symmetric optical diffuser that scatters light in a first direction with a first viewing angle AH and in a second direction orthogonal to the first direction with a second viewing angle AV, where AV is substantially equal to AH. The symmetric optical diffuser includes an optically transparent first layer and a plurality of randomly arranged optically transparent beads partially embedded in the first layer leaving portions of the beads exposed. The optical construction also includes a specular reflector that reflects light that is not scattered by the symmetric optical diffuser. The specular reflector has a first average reflectance Ro in the visible at zero incident angle and a second average reflectance R60 in the visible at 60 degree incident angle. Ro/R60 is at least about 1.5. The optical construction also includes a light absorbing layer that absorbs light that is not reflected by the specular reflector.

Abstract: A communication article and system comprising a writing member having a dry erasable front surface and a projection member is disclosed. The projection member includes an asymmetric optical diffuser that scatters light in a first direction with a first viewing angle AH, and in a second direction orthogonal to the first direction with a second viewing angle AV. The ratio AH/AV is at least about 2.

Abstract: Presently described are multilayer optical films, oriented polyester films, negatively birefringent copolyester polymers, fluorene monomers, and polyester polymers prepared from such fluorene monomers. In one embodiment, the multilayer optical film comprises at least one first birefringent optical layer; and at least one second optical layer having a lower birefringence than the first optical layer; wherein at least one of the optical layers comprises a negatively birefringent polyester polymer comprising a backbone and repeat units comprising at least one pendent aromatic group that is conformationally locked relative to the backbone.

Abstract: A light diffusing optical construction is disclosed. The optical construction includes an asymmetric optical diffuser that scatters light in a first direction with a first viewing angle AH and in a second direction orthogonal to the first direction with a second viewing angle AV. The ratio AH/AV is at least about 2. The optical construction also includes a substantially specular reflector that reflects light that is not scattered by the asymmetric optical diffuser. The substantially specular reflector has a first average reflectance Ro in the visible at a substantially zero incident angle and a second average reflectance R45 in the visible at a substantially 45 degree incident angle. The ratio Ro/R45 is at least about 1.5. The optical construction also includes a light absorbing layer that absorbs light that is not reflected by the specular reflector.

Abstract: The present invention relates to multilayer optical films and birefringent copolyester films. The birefringent copolyester optical layer or birefringent copolyester film comprises a major amount of naphthalate units, ethylene units, and a minor amount of branched or cyclic C4 to C10 alkyl units. Also described are certain copolyester polymeric materials further comprising subunits of a phthalate ionomer such as dimethyl sulfosodium isophthtalate ionomer.

Abstract: A reflective film includes interior layers that selectively reflect light by constructive or destructive interference, the layers extending from a first to a second zone of the film. The interior layers include a first set of layers composed of a first material and a second set of layers composed of a different second material. The first and second sets of layers are both birefringent in the first zone, but at least some of the layers have reduced birefringence in the second zone. The reduced birefringence produces a second reflective characteristic in the second zone that differs from a first reflective characteristic in the first zone, this difference not being substantially attributable to any thickness difference between the first and second zones. The film may also incorporate absorbing agents to assist in the manufacture or processing of the film. Related methods and articles are also disclosed.

Abstract: A reflective film includes microlayers arranged into optical repeat units, each optical repeat unit including a negatively birefringent microlayer. The microlayers are tailored to provide the film with on-axis polarizing properties, such that normally incident light polarized along a block axis is substantially reflected and normally incident light polarized along a pass axis is substantially transmitted. On-axis transmission for the block axis may be <20%, and on-axis transmission for the pass axis may be >70%. The microlayers also provide the film with angularly dependent polarizing properties: p-polarized light incident in a block plane of incidence is substantially reflected at near-normal angles but substantially transmitted at an oblique angle. The film transmits unpolarized light incident in this plane more strongly at the oblique angle than at normal.

Abstract: The present invention relates to multilayer optical films and birefringent copolyester films. The birefringent copolyester optical layer or birefringent copolyester film comprises a major amount of naphthalate units, ethylene units, and a minor amount of branched or cyclic C4 to C10 alkyl units. Also described are certain copolyester polymeric materials further comprising subunits of a phthalate ionomer such as dimethyl sulfosodium isophthtalate ionomer.

Abstract: In one embodiment, the invention provides a polyethylene terephthalate film comprising a biaxially oriented and birefringent film polyethylene terephthalate film having at least one layer having a thickness of from 10 mils (0.25 mm) to 25 mils (0.64 mm), wherein the film is formed from a polyethylene terephthalate resin comprising the reaction product of dimethyl terephthalate, terephthalic acid, or a combination thereof ethylene glycol, a diol or triol monomer other than ethylene glycol and from 0.9 to 3 mol percent of a sulfonate monomer having an inorganic counterion based on 100 mol percent dimethyl terephthalate, terephthalic acid, or a combination thereof.

Abstract: A communication article and system comprising a writing member having a dry erasable front surface and a projection member is disclosed. The projection member includes an asymmetric optical diffuser that scatters light in a first direction with a first viewing angle AH, and in a second direction orthogonal to the first direction with a second viewing angle AV. The ratio AH/AV is at least about 2.

Abstract: The present invention relates to multilayer optical films and birefringent copolyester films. The birefringent copolyester optical layer or birefringent copolyester film comprises a major amount of naphthalate units, ethylene units, and a minor amount of branched or cyclic C4 to C10 alkyl units. Also described are certain copolyester polymeric materials further comprising subunits of a phthalate ionomer such as dimethyl sulfosodium isophthtalate ionomer.