Abstract: Laminar thermoplastic film constructions comprising a layer of low density polyethylene bonded to a layer of a dissimilar polymer blend comprising high density polyethylene and polyethylene copolymers. In particular such copolymers comprise polyethylene copolymerized with another alpha olefin containing from about 3 up to about 15 carbon atoms. Such copolymers are also characterized by being linear, low density polymers having densities which are below about 0.94 grams/cc.

Abstract: A process for forming a contact through-hole in an insulating layer lying between multilayer conductors comprises the steps of: forming a photoresist layer on the insulating layer with an aperture therein exposing, and defining, the position of a through-hole to be found in the insulating layer; wet-etching the insulating layer in the portion exposed by the aperture to form a preceding hole; heating the photoresist layer to bend the end portion of the photoresist layer into the preceding hole but to a limited extent such that the end portion does not come into contact with sloped side wall of the preceding hole; and dry-etching the insulating layer to complete the etching of the contact through-hole while maintaining the desired, sloped sidewall thereof, thereby preventing cracks from occurring in the upper one of the multilayer conductors in the portions thereof which extend through the through-hole.

Abstract: A method for preparing a resistive screen for underwater sound absorption consisting of a metallic honeycomb structure, adding a thermosetting plastic material to the cells within said structure, heating said structure under pressure and forming small apertures within said thermosetting plastic material.

Abstract: The invention relates to a method of forming a metal-resin bond in the presence of environmental contamination of the metal surface by, for example, adsorbed water. The method consists of cleaning the metal surface and then coating it with a pre-treatment material adapted to displace the adsorbed contaminant and to be displaced in turn by the applied resin. The method is particularly relevant to the formation of steel/epoxy resin bonds underwater for the repair of submerged structures. The pre-treatment material may consist of a hydrocarbon solvent containing in solution a surfactant such as an ionic surfactant together with a viscous hydrocarbon such as petroleum jelly.

Abstract: A valuable document is protected from counterfeiting by applying an extremely thin layer of metal to the document at predetermined locations. The thin layers of metal form a "ghost image" which changes in appearance as the angle of view is varied, making the valuable document easily recognizable by a lay observer. The portions of the valuable document covered by the thin layers of metal reflect ultra-violet and infra-red light making a photocopy of the valuable document strikingly different in appearance than the original document. Counterfeiting the document by any method is extremely difficult as the process of applying the thin layers of metal is one of high technology, not readily available to the public.

Abstract: Adhesion and environmental resistance of rubber-metal assemblies is significantly improved by the use of metal substrates which have been nitrided at least in the bond area and subsequently exposed to a non-reactive gas, such as argon, prior to applying the adhesive.

Abstract: Protective coating systems are reinforced by first laying a suitable mesh screen of plastic, metal or the equivalent on the surface to be protected. Thereafter, a thin layer of a coating composition, e.g., a latex cement, is poured over the mesh and allowed to set. In this operation the mesh is bonded by means of the coating composition to said surface. The screen also protrudes to the upper surface of said layer and when the latter has been allowed to set, a second layer is applied resulting in a system in which the reinforcing mesh not only aids in forming a durable bond between said first layer and said surface, but also likewise renders the two layers thus formed resistant to spalling or separating caused from expansion or contraction of said surface.

Abstract: A process is described for forming a plasma nitride (SiNy) layer and a tapered opening through the layer so that the opening may more readily receive ohmic contacts. During the formation of the plasma nitride layer, more silane (over ammonia) is used to form a silicon rich upper portion of the layer. During the subsequent etching of this layer to form the opening, the silicon rich portion of the plasma nitride layer etches more quickly than the remainder of the layer and this results in the formation of the tapered opening through the layer.

Abstract: The method comprises producing on the surface to be etched a stencil of a light-hardened PVA. The stencil is produced by light hardening selected portions of a film or coating consisting essentially of dichromate-sensitized PVA containing about 5 to 30 weight percent with respect to the weight of PVA solids of N-methylol acrylamide. After light hardening, the nonhardened portions of the film are removed, thereby producing the stencil. The stencil is baked to improve its etch resistance, the surface is etched through the stencil, and then the stencil is removed from the surface.

Abstract: The method comprises producing on the surface to be etched a stencil of a light-hardened PVA. The stencil is produced by light hardening selected portions of a film or coating consisting essentially of dichromate-sensitized PVA. The PVA is about 85% to 97% hydrolyzed and has a molecular weight of 75,000 to 100,000. After light hardening, the nonhardened portions of the film are removed, thereby producing the stencil. The stencil is baked to improve its etch resistance, the surface is etched through the stencil, and then the stencil is removed from the surface.

Abstract: A method to eliminate stresses and consequent warping in elevated-temperature cured adhesive bonded parts with different coefficients of thermal expansion.