Abstract: Silicon tetrachloride is processed to ultrahigh purity by subjecting it to a specific succession of purification steps. These steps include the photochlorination of the SiCl.sub.4 using a reactor that allows a long residence time for the SiCl.sub.4. After photochlorination, highly volatile products such as HCl are removed and the remaining impurities are then separated by a distillation technique.

Abstract: The use of polymers including an indanone entity for use as a resist in a photosensitive body used in a lithographic process leads to desirable results. These resists have excellent resolution essentially equivalent to that obtainable with poly(methyl methacrylate). Additionally, the sensitivities of these polymers to the actinic radiation typically used in photolithographic processes, e.g., radiation from a mercury lamp, is significantly better than that obtained with poly(methyl methacrylate).

Abstract: The presence of hydroxyl impurities (--OH) in optical fiber precursor materials produces optical losses in fibers made from the precursor material, as in the modified chemical vapor deposition process. Typical precursor materials include SiCl.sub.4, GeCl.sub.4, POCl.sub.3, and PCl.sub.3. Losses due to --OH impurities occur near various wavelengths of current interest for optical communications systems. Adding chlorine and PCl.sub.3 to impure SiCl.sub.4, GeCl.sub.4, or POCl.sub.3 reduces the amount of --OH impurities and produces POCl.sub.3 and HCl. The HCl may be readily removed, while the POCl.sub.3 is typically left in the material. Bromine may be used instead of chlorine, and PBr.sub.3 may be used instead of PCl.sub.3. In addition, --OH impurities in PCl.sub.3 may be removed by the addition of chlorine or bromine, with the resulting HCl or HBr typically being removed.

Abstract: A technique is described for the preparation of an electrically conductive adhesive system and electrical devices including such system. Briefly, the adhesive system comprises a novolac epoxy resin and a chemically blocked imidazole curing agent in combination with a viscosity reducer and conductive particles. The resulting adhesive system is found comparable to commercially available adhesive systems and is superior thereto with respect to thermal stability.

Abstract: A latent-imaging photopolymer system for recording thick refractive index patterns is disclosed. The system utilizes a porous matrix which has been sensitized by chemisorption of a photosensitive polymerization initiator. The sensitized matrix is exposed to light in the desired pattern. This light destroys initiator to impress the pattern. Then the pores are filled with a monomer composition. Finally the entire filled matrix is irradiated to induce polymerization initiation by the sensitizer remaining after the initial exposure. Polymerization produces locally induced refractive index gradients corresponding to the pattern of the light in the initial exposure step.

Abstract: A latent-imaging photopolymer system for recording thick refractive index patterns is disclosed. The system utilizes a porous matrix which has been sensitized by chemisorption of a photosensitive polymerization initiator. The sensitized matrix is exposed to light in the desired pattern. This light destroys initiator to impress the pattern. Then the pores are filled with a monomer composition. Finally the entire filled matrix is irradiated to induce polymerization initiation by the sensitizer remaining after the initial exposure. Polymerization produces locally induced refractive index gradients corresponding to the pattern of the light in the initial exposure step.

Abstract: A water-based polymeric coating comprising a novolak resin is deposited electrolytically from a solution of a novolak resin upon a conductive substrate at an initial current density ranging from 10-30 milliamperes per square centimeter. The resultant coating, after cross linking by subsequent chemical treatment, is flexible, firmly adherent and evidences good thermal stability and insulation characteristics, so suggesting its use as a cover coat for printed circuits.

Abstract: A method for retarding corrosion of metal surfaces involves rinsing the surface to be coated in an aqueous solution of benzotriazole and dip-coating the structure in a solution of a methacrylate homopolymer or copolymer. The coated surface is than heated to yield an adherent polymer on the metal surface.