Abstract: Ethylenically unsaturated polymerizable acrylic (or methacrylic) monomers having pendant halogenated carbazole moieties, useful for the production of high refractive index polymers, are disclosed. The monomers are useful for the bonding of optical elements in the fabrication of optical devices.

Abstract: Melt-processable polyesteramides capable of exhibiting melt-phase anisotropy at temperatures of approximately 360.degree. C. and lower are disclosed. The polyesteramides contain certain essential 2,2'-substituted biphenylene radicals and repeating units which provide ester and amide linkages. The polyesteramides exhibit melt processability suitable for processing into films and fibers.

Abstract: Aromatic polyesteramides exhibiting melt processability are disclosed. The polyesteramides comprise certain essential repeating units of the formulas ##STR1## wherein X is alkyl, alkoxy, trifluoromethyl, halogen or nitro. The polyesteramides exhibit melt anisotropy. Films and fibers combining a balance of properties suited to high strength service can be provided from the melt-processable polyesteramides.

Abstract: A folding tripod the legs of which are moveable into operative positions where they can be arrested to impart stability and firmness to the tripod, by clamping them against peripheral surfaces of brackets protruding from a center post of the tripod. Each bracket is provided with a bearing acting as a fulcrum for its associated leg, and with a peripheral surface surrounding the bearing, the surface having at least one portion which is closer to the bearing than other portions, whereby the legs tend to resist pivotal movement from an operative, load bearing position while permitting movement in an opposite direction to facilitate their release and subsequent storage.

Abstract: A class of polyesters comprising recurring units having certain bis(trifluoromethyl)biphenylene radicals is disclosed. The polyesters exhibit favorable solubility properties in certain organic solvents so as to facilitate the production of the polyesters via polycondensation methods to film- and fiber-forming molecular weights. Monomeric compounds comprising a bis(trifluoromethyl)biphenylene radical and useful for the production of the polyesters are also disclosed.

Abstract: A class of aromatic polyesters exhibiting melt processability is disclosed. A portion of repeating 2,2'-substituted-biphenylene radicals in an aromatic polyester is replaced by certain other aromatic radicals to provide an aromatic polyester which exhibits low-melting properties, melt processability and melt anisotropy. The aromatic polyesters can be melt processed to films and fibers.

Abstract: There are described novel perylene dyes which have at least one, and preferably two, substituted twisted biphenylene radicals. The substituted biphenylene radicals include substituents which confer a non-coplanar molecular configuration about the long axis of the dye molecule. The dyes are soluble in various liquid crystal materials and exhibit a high order parameter in solutions of liquid crystal material. Also disclosed are liquid crystal compositions and liquid crystal devices.

Abstract: Aromatic polyesters exhibiting melt processability are disclosed. The polyesters comprise repeating units of the formula ##STR1## wherein X is hydrogen, halogen, alkyl or nitro. The polyesters exhibit low-melting properties, melt processability and melt anisotropy. The aromatic polyesters can be melt processed to films and fibers.

Abstract: Optical devices including a molecularly oriented highly birefringent polymer are disclosed. The devices include molecularly oriented polymers comprising recurring units which exhibit a distribution of high electron density about the long axes of the polymer and the recurring units thereof. Transparent birefringent polymers comprising a plurality of recurring units having a substantially cylindrical distribution of electron density about the long axis of such units and the chain-extended polymers are included in optical devices and articles. The polymers exhibit high birefringence and simulate in a polymer the optical properties of a uniaxial crystal.

Abstract: Optical devices including a molecularly oriented highly birefringent polymer are disclosed. The devices include molecularly oriented polymers comprising recurring units which exhibit a distribution of high electron density about the long axes of the polymer and the recurring units thereof. Transparent birefringent polymers comprising a plurality of recurring units having a substantially cylindrical distribution of electron density about the long axis of such units and the chain-extended polymers are included in optical devices and articles. The polymers exhibit high birefringence and simulate in a polymer the optical properties of a uniaxial crystal.

Abstract: Optical devices including a molecularly oriented highly birefringent polymer are disclosed. The devices include molecularly oriented polymers comprising recurring units which exhibit a distribution of high electron density about the long axes of the polymer and the recurring units thereof. Transparent birefringent polymers comprising a plurality of recurring units having a substantially cylindrical distribution of electron density about the long axis of such units and the chain-extended polymers are included in optical devices and articles. The polymers exhibit high birefringence and simulate in a polymer the optical properties of uniaxial crystal.

Abstract: A variable focus lens system comprising an elastomeric lens structured to undergo shape changes and corresponding focal length changes in a continuous manner over a predetermined range in response to variations in a tensile stress uniformly distributed around the peripheral edges of the lens element. The lens element is preferably structured of silicon rubber materials which are molded around an extensible and contractable annular coil spring arrangement which is utilized to apply the required variable tensile stress.

Abstract: This invention relates to photographic processes and products for forming an image in dye from a colorless precursor of a preformed image dye which is substituted with a moiety comprising a 1,3-sulfur-nitrogen group that undergoes cleavage in the presence of silver ion and/or soluble silver complex, which moiety maintains said precursor in its colorless form at least until the 1,3-sulfur-nitrogen group undergoes cleavage imagewise to correspond to the imagewise distribution of silver ion and/or soluble silver complex made available as a function of development.

Abstract: A class of polyamides comprising recurring units having certain substituted-biphenylene or substituted-stilbene radicals is disclosed. The substituted radicals include substituents so as to confer a non-coplanar molecular configuration and a substantially cylindrical distribution of electron density about the long axis of the recurring units and the chain-extended polymers including such radicals.Molecularly oriented polymers of the invention exhibit optically uniaxial properties. The highly birefringent polymers are suited to application in optical filter and other devices where a refractive and birefringent material is desired.

Abstract: A class of polyamides comprising recurring units having certain substituted-biphenylene or substituted-stilbene radicals is disclosed. The substituted radicals include substituents so as to confer a non-coplanar molecular configuration and a substantially cylindrical distribution of electron density about the long axis of the recurring units and the chain-extended polymers including such radicals.Molecularly oriented polymers of the invention exhibit optically uniaxial properties. The highly berefringent polymers are suited to applicaiton in optical filter and other devices where a refractive and birefringent material is desired.

Abstract: Disclosed is a class of polymers comprising recurring units of the formula ##STR1## where Mu is a divalent radical having the formula ##STR2## where each of D, D', E and E' is hydrogen, alkyl or substituted-alkyl; and Az is a divalent radical having the formula ##STR3## where each of R and R' is hydrogen, alkyl, aryl, alkaryl or aralkyl and W is a single bond, alkylene or alkenylene; or Az is a divalent radical having the formula ##STR4## where each of Y and Y' represent the atoms necessary to complete a piperazine or substituted-piperazine radical.Molecularly oriented polymers of the invention exhibit birefringence and can be utilized in filter, polarizing and other optical devices.

Abstract: Optical devices including a molecularly oriented highly birefringent polymer are disclosed. The devices include molecularly oriented polymers comprising recurring units which exhibit a distribution of high electron density about the long axes of the polymer and the recurring units thereof. Transparent birefringent polymers comprising a plurality of recurring units having a substantially cylindrical distribution of electron density about the long axis of such units and the chain-extended polymers are included in optical devices and articles. The polymers exhibit high birefringence and simulate in a polymer the optical properties of a uniaxial crystal.

Abstract: A variable focus lens system comprising an elastomeric, integrally molded, optical member and mounting arrangements therefor by which the axial position and the shape of a central lens part of the optical member can be changed in correspondence with one another to provide the lens system with focusing action over a predetermined range.

Abstract: A class of polyesters comprising recurring units having certain bis(trifluoromethyl)biphenylene radicals is disclosed. The polyesters exhibit favorable solubility properties in certain organic solvents so as to facilitate the production of the polyesters via polycondensation methods to film- and fiber-forming molecular weights. Monomeric compounds comprising a bis(trifluoromethyl)biphenylene radical and useful for the production of the polyesters are also disclosed.

Abstract: Solid compositions are disclosed comprising a complex of water; a benzotriazole of the formula ##STR1## wherein R.sup.1 and R.sup.2 are independently hydrogen, a monovalent organic radical, halogen, or nitro; and at least one water-soluble base having a basicity greater than that of the benzotriazole and capable of dissociating to provide an anion and a monovalent or divalent metal cation. The compositions have melting ranges above 35.degree. C. and are capable of releasing a substantial portion of the water contained therein to the surrounding environment when melted. The compositions can be employed in thermally developable photographic film units as thermally induced water-releasing materials which provide water to the internal environment of the film unit when the film unit is heated sufficiently to melt the composition.