Abstract: Birefringent multilayer optical films in which the refractive indices in the thickness direction of two adjacent layers are substantially matched have a Brewster angle (the angle at which reflectance of p-polarized light goes to zero) which is very large or is nonexistant. This allows for the construction of multilayer mirrors and polarizers whose reflectivity for p-polarized light decreases slowly with angle of incidence, are independent of angle of incidence, or increase with angle of incidence away from the normal. As a result, multilayer films having high reflectivity (for both planes of polarization for any incident direction in the case of mirrors, and for the selected direction in the case of polarizers) over a wide bandwidth, can be achieved.

Abstract: An optical film is provided which includes a disperse phase of polymeric particles disposed within a continuous birefringent matrix. The film is oriented, typically by stretching, in one or more directions. The size and shape of the disperse phase particles, the volume fraction of the disperse phase, the film thickness, and the amount of orientation are chosen to attain a desired degree of diffuse reflection and total transmission of electromagnetic radiation of a desired wavelength in the resulting film.

Abstract: Novel mixtures of perfluoroalkyl halides and derivatives thereof are described. These mixtures contain some compounds with a straight perfluoroalkyl group and some with a branched perfluoroalkyl group. Methods of preparation and use are also described.

Abstract: Electroluminescent lamps incorporating one or more multilayer optical films according to the present invention to polarize and/or reflect light. The multilayer optical films exhibit the ability to reflect significant amounts of normal and off-axis incident light.

Abstract: A method for improving the recovery of gold and silver from precious metal ore is disclosed. The method comprises contacting precious metal ore with an aqueous solution containing certain fluoroaliphatic surfactants.

Abstract: Highly efficient diffusely reflecting multilayer mirrors diffusely reflect light incident upon them. Highly efficient diffusely reflecting multilayer polarizers diffusely reflect light of one polarization while diffusely transmitting the other polarization. The diffusely reflecting mirror includes a light diffusing element and a multilayer mirror element. The diffusely reflecting polarizer includes a light diffusing element and a multilayer reflective polarizing element.

Abstract: An optical film with a disperse phase of polymeric particles disposed within a continuous birefringent matrix. The film is oriented, typically by stretching, in one or more directions. The size and shape of the disperse phase particles, the volume fraction of the disperse phase, the film thickness, and the amount of orientation are chosen to attain a desired degree of diffuse reflection and total transmission of electromagnetic radiation of a desired wavelength in the resulting film.

Abstract: Extrudable compositions comprising a thermoplastic polyester continuous phase, a thermoplastic polyolefin discrete phase, and a polyester-polyether, diblock, compatibilizer are disclosed. Voided films made from the composition are also disclosed. The voided films have paper-like texture and appearance.

Abstract: Reflective polarizers, which transmit one polarization and reflect the other polarization, have an extended red band edge in the off-axis transmission spectrum to control off axis color (OAC) hue. To control the OAC hue, the red band edge of the off-axis transmission spectrum, or OAC spectrum, is shifted beyond the boundary for red light, or to at least 600 nm. Even more preferably, the OAC spectrum is extended further into the red than any red emission peak of an associated lamp providing light into a system in which the reflective polarizer is used. The concept applies equally well to any type of reflective polarizer, such as multilayer reflective polarizers, cholesteric reflective polarizers, and the like. The resulting reflective polarizers are very useful for many different applications, such as liquid crystal displays.

Abstract: A method for making multilayer polyester films is provided wherein a slippery surface is imparted to the film, without the use of slip agents, through appropriate crystallization and orientation of the film.

Abstract: A multilayer film is provided with a slippery surface layer by crystallization in an underlying layer which results in the deformation of an overlying surface layer without the use of particulate slip agents. The films may be formed by alternating layers of a naphthalene dicarboxylic acid polyester and a terephthalic acid polyester.

Abstract: An optical film is provided which includes a disperse phase of polymeric particles disposed within a continuous birefringent matrix. The film is oriented, typically by stretching, in one or more directions. The size and shape of the disperse phase particles, the volume fraction of the disperse phase, the film thickness, and the amount of orientation are chosen to attain a desired degree of diffuse reflection and total transmission of electromagnetic radiation of a desired wavelength in the resulting film.

Abstract: A gas analysis apparatus includes an optical source for providing an optical signal, an interferometer for modifying the optical signal, and an optical signal detector. A first housing having folded path optical elements positioned therein; the elements defining a sample path through which the optical signal passes from the interferometer to the optical signal detector. The first housing has a sample introduction opening. A second housing defines a sample holding volume. The second housing is sealingly positioned with respect to the first housing for fluidly connecting the sample path of the first housing with the sample holding volume of the second housing through the sample introduction opening. A recirculating flow may be provided between the sample path and the sample holding volume. The second housing may include an access port with a detachable access closure through which a material may be placed in the sample holding volume. A method for using the apparatus is also described.

Abstract: A multilayer polyester film, and a method for making the same, is provided. The film consists of alternating layers of polyethylene terephthalate and polyethylene naphthalate. Biaxial orientation and subsequent restrained heat setting of these materials results in thin films with tensile moduli in both stretch directions well in excess of the values obtained with monolithic films of either material. In some embodiments, a slippery surface is imparted to the film without the use of conventional slip agents.

Abstract: A method for imparting soil resistance to unscoured carpets, and a carpet treated in accordance with the method, are provided. In accordance with the method, a substrate comprising unscoured carpet fibers is treated with the ammonium salt of a polycarboxylic acid, such as an ammonium salt of a hydrolyzed styrene/maleic anhydride copolymer. The treated substrate is found to have enhanced water and oil repellency in both heat cured and room temperature drying conditions.

Abstract: A method for imparting soil resistance to unscoured carpets, and a carpet treated in accordance with the method, are provided. In accordance with the method, a substrate comprising unscoured carpet fibers is treated with the ammonium salt of a polycarboxylic acid, such as an ammonium salt of a hydrolyzed styrene/maleic anhydride copolymer. The treated substrate is found to have enhanced water and oil repellency in both heat cured and room temperature drying conditions.

Abstract: A method for imparting soil resistance to unscoured carpets, and a carpet treated in accordance with the method, are provided. In accordance with the method, a substrate comprising unscoured carpet fibers is treated with the ammonium salt of a polycarboxylic acid, such as an ammonium salt of a hydrolyzed styrene/maleic anhydride copolymer. The treated substrate is found to have enhanced water and oil repellency in both heat cured and room temperature drying conditions.

Abstract: Compositions for treating pulp slurry in the wet end comprising (A) a mixture of fluoroaliphatic radical-containing phosphate esters comprising at least 70% of a phosphate monoester, e.g., C.sub.8 F.sub.17 SO.sub.2 N(C.sub.2 H.sub.5)C.sub.2 H.sub.4 OP(O) (OH) (O.sup.- NH.sub.4.sup.+) and (B) an alkyl ketene dimer are disclosed. Methods for using such compositions and the resulting treated products are also disclosed.

Abstract: A method and apparatus are provided for using certain hydrofluoroethers (HFEs) as low temperature heat transfer media in secondary loop refrigeration systems. These materials exhibit a low, somewhat linear Temperature Difference Factor over the temperature range of -15.degree. C. to -65.degree. C., making them ideal for use as low temperature heat transfer media. The HFEs of the present invention are nonflammable, nontoxic, environmentally benign, and have a high heat transfer capacity and low viscosity over the required operating temperatures. Furthermore, since these materials have high boiling points and low freezing points, they are not prone to phase changes over the required operating temperatures, and do not require pressurized systems.

Abstract: A method for improving the recovery of gold and silver from precious metal ore is disclosed. The method comprises contacting precious metal ore with an aqueous solution containing certain fluoroaliphatic surfactants.