Abstract: A process and an apparatus for producing a preform for plastic optical fiber having a refractive index distribution in which the refractive index is gradually decreased from the center of the preform toward the outer periphery thereof, by depositing a deposition layer comprising a polymer A (refractive index: N.sub.a) and a refractive index modifier having a refractive index different from that of the polymer A onto a surface of a rod member rotating about an axis thereof, by use of vapor-phase deposition based on a CVD (Chemical Vapor Deposition) process, or a coating process. A plastic optical fiber preform comprising deposition layers having a gradually decreasing refractive index distribution is formed by changing the mixing ratio between the polymer A and the refractive index modifier constituting the deposition layer.

Abstract: Methods for coating a prosthetic surface with anti-thrombogenic, or anti-coagulant, proteins are disclosed. The methods involve contacting a surface of a prosthetic material with a composition containing multimers of fibrin degradation products. These multimers, preferably D-dimers, have cross-linked D-domains. The methods of the invention are useful for providing an anti-thrombogenic coating on prosthetic implants which are exposed to a patient's blood after implantation, for example vascular grafts and artificial heart valves.

Abstract: The present invention provides a method for coating a titanium based component with diamond-like carbon to reduce the thrombogeneticity of the component. In a preferred embodiment, the titanium based component is a heart valve.According to the present invention, the component is placed in a vacuum chamber and heated to about 600.degree. -650.degree. C. (1112.degree.-1202.degree. F.). Thereafter, silicon is then deposited onto the component, and the component is simultaneously bombarded with a beam of energetic ions to form a metal-silicide bonding layer. The component then is cooled to at least about 100.degree. C. (212.degree. F.), preferably about 80.degree. C. (176.degree. F.), and a diamond-like carbon precursor is condensed onto the metal-silicide bonding layer. The precursor is simultaneously bombarded with a beam of energetic ions to form a coating of diamond-like carbon.

Abstract: Polymeric surfaces of medical devices or components of medical devices are provided that have enhanced biocompatibility properties. The polymeric surface presents an anti-thrombogenic, fibrinolytic or thrombolytic interface with body fluids such as blood during implantation or medical procedures. The biocompatibility enhancing agent is secured to the polymeric substrate by a spacer molecule which is covalently bound to the polymeric substrate which had been subjected to radiofrequency plasma treatment with a water vapor medium.

Abstract: A method for forming vascular graft prostheses is described. In particular, the method relates to determining the carrying volume of a gelable material to fill the interstices of a fabric prosthesis, applying that carrying volume of gelable material to the prosthesis, and crosslinking the gelable material to form uniform gel-coated prostheses having low porosity.

Abstract: A method of permanently modifying the surface of a substrate material so as to develop a microscopically smooth, biocompatible surface thereon comprises covalently grafting a biocompatible polymeric material to the surface of the substrate material by radio frequency plasma-induced grafting. The biocompatible polymeric material is preferably the same as the substrate material. In addition, a method of permanently modifying the surface of a substrate material comprises subjecting the substrate surface to radio frequency plasma sufficient to raise the temperature at the substrate material to just above the glass transition temperature (T.sub.g) of the substrate material for a time sufficient to produce a microscopically smooth, biocompatible surface on the substrate material. Further, a prosthesis used in mammals, including an intraocular lens, comprises a polymeric material core and a biocompatible polymeric material covalently grafted to the polymer core by radio frequency plasma induction.

Abstract: The coated stent comprises a cylindrical wall formed by meshed wires and a covering layer of elastic material extending on a portion of its length, with an outer surface, and totally embracing the wire mesh.Method of coating the stent using a lifting medium and then an elastomeric composition dissolved in solvent are disclosed.

Abstract: Methods of impregnating various polymer substrates with an impregnation additive, by simultaneously contacting the polymer substrate with an impregnation additive, carrier liquid, and supercritical fluid are provided. The impregnation additive is substantially insoluble in the supercritical fluid, and the carrier liquid is preferably substantially insoluble in the supercritical fluid.

Abstract: A method for making an intravascular stent by applying to the body of a stent a solution which includes a solvent, a polymer dissolved in the solvent and a therapeutic substance dispersed in the solvent and then evaporating the solvent. The inclusion of a polymer in intimate contact with a drug on the stent allows the drug to be retained on the stent during expansion of the stent and also controls the administration of drug following implantation. The adhesion of the coating and the rate at which the drug is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer and the ratio of drug to polymer in the solution. By this method, drugs such as dexamethasone can be applied to a stent, retained on a stent during expansion of the stent and elute at a controlled rate.

Abstract: A method for pretreating the surface of a medical device, and of applying a biological coating in a further step, uses the plasma polymerization technique or the plasma grafting technique. A functional monomer, i.e. a monomer with a functional group, or a mixture of a pure monomer and a substance which can provide the required functional groups under spark discharge or under the influence of charge carriers, results in a polymer coating with free functional groups which may react with the biological coating to provide optimum adhesion of the biological coating. The process is carried out in a pressure-tight chamber with an inlet for the functional monomer under low pressure and electromagnetic radiation provided by a radiation source.

Abstract: An anti-infective medical article has chlorhexidine bulk distributed throughout a polyurethane base layer and may have a coating layer on the base layer. The coating layer may be chlorhexidine permeated into the surface or it may be an antibiotic, antithrombogenic agent or a polymeric surface layer laminated onto the base layer. The invention includes a method for preparing the article wherein a homogeneous melt of polymer and chlorhexidine is prepared by twin screw compounding and the melt is extruded to give a medical article having bulk distributed chlorhexidine.

Abstract: A process for producing a polymeric surface coating which faciliates attachment of cells on a polymeric substrate. The coating is deposited by plasma deposition of an amide monomer vapour. The coated product is suitable for use in tissue culture trays and biomedical implants.

Abstract: A medical device is coated with a solution of TDMAC heparin and then allowed to air dry. Thereafter, the coated medical device is exposed to gamma ray radiation. The gamma radiation strengthens the bond of the TDMAC to the material of the medical device. In a variation of this method, TDMAC heparin coated and gamma ray irradiated medical device is heated for an extended period of time. This heating has been found to further strengthen the bond of the TDMAC heparin to the medical device.

Abstract: A compound of formula: ##STR1## in which X.sup.1 is a reactive group that can react to form a covalent bond with a reactive group on the surface of a material to be rendered biocompatible, X.sup.2 is a group --O.sup..crclbar. or a precursor of such a group, n is 2, 3 or 4, Y is a group --N.sup..sym. R.sub.3 A.sup..crclbar. wherein each R, which may be the same or different, is a C.sub.1 -C.sub.4 alkyl group and A.sup..crclbar. is an anion present when X.sup.2 is an electrically neutral group or Y is ##STR2## wherein R.sup.1 together with X.sup.2 forms a direct bond between the nitrogen and the phosphorus atoms.

Abstract: A slurry for joining metallic or ceramic surfaces or for coating metallic or ceramic and refractory surfaces, comprising a liquid suspending medium and at least two constituents in particulate form suspended in the medium, the constituents being so selected and proportioned as to undergo combustion synthesis when ignited. A method for coating or joining metallic or ceramic surfaces comprises applying such a slurry to a surface to be coated or to surfaces to be joined, and igniting the slurry to cause combustion synthesis.

Abstract: A method of thermally spraying a solid lubricant (i.e. graphite or BN) impregnated metal matrix onto a metal target, using the steps of: (a) creating a flame or arc into which a consummable strand is fed, the strand being constituted as a hollow sheath of metal and a core therein comprising essentially solid lubricant powder particles, the flame or arc melting the metal of such strand; (b) applying a pressurized jet of atomizing gas to the melt and included graphite particles to project a spray of molten heavy metal and graphite particles generally homogeneously distributed throughout such spray, said graphite being protected against ablation during transit from the flame or arc to the target; and (c) surface heat treating essentially only the deposit to precipitate additional graphite while densifying the metal and controlling microstructure.

Abstract: Surfaces of polymers, particularly polyesters, can be fluorinated by deposition of a fluorocarbon from solution. The fluorocarbon may be an amorphous fluoropolymer, such as the copolymer of tetrafluoroethylene and bis-2,2-trifluoromethyl-4,5-difluoro-1,2-dioxole sold under the trademark TEFLON AF.RTM., which is soluble in fluorinated alkanes and other fluorinated liquids such as those sold under the trademark FLUORINERT.RTM.. Surface-fluorinated polyesters, particularly in knitted fabric form, are useful as vascular grafts: the fluorinated surface reduces thrombogenicity and complement activation. The disadvantages of known surface fluorination methods, such as the cold plasma or glow discharge process, are avoided.

Abstract: Methods of impregnating various polymer substrates with an impregnation additive, by simultaneously contacting the polymer substrate with an impregnation additive, carrier liquid, and supercritical fluid are provided. The impregnation additive is substantially insoluble in the supercritical fluid, and the carrier liquid is preferably substantially insoluble in the supercritical fluid.

Abstract: Methods of forming a chemical barrier against the transmission of disease-causing microbes and other harmful agents through a membrane such as latex. In the principal method, a mold or former is coded with a coagulant, which is dried, and then the former is dipped into liquid latex, which is allowed to gel, and then the former is dipped into a solution containing the biocide, and then the former is dipped again into the liquid latex, after which the entire coating on the former is cured. Alternatively, the biocide may be sprayed or otherwise applied onto the gelled latex.

Abstract: A treatment for metallic surfaces and devices having metallic surfaces is described. A film of heptafluorobutylmethacrylate (HFBMA) is applied to a surface by radiofrequency (RF) plasma deposition and subsequently treated with a biologically active agent. A water vapor RF plasma treatment of the HFBMA coating provides reactive groups thereon which can covalently bond to the biologically active agent. Alternatively, a spacer group can be bonded to the activated HFBMA and the biologically active agent can then be bonded to the spacer group. Devices coated according to the invention possess enhanced biocompatibility and the HFBMA coatings are durable even under severe crimping and expansion conditions.

Abstract: A colored porous polytetrafluoroethylene material prepared by impregnating a colorant in a porous polytetrafluoroethylene material having a fine fiber structure consisting of fibers and nodes connected to one another through the fibers, and then heating the porous material at a temperature of at least a melting point of the porous material has porosity inherently possessed by the porous material and no distortion of a colored line.

Abstract: Preparation of feed screw having a wear resistant alloy coating thereon for the injection molding or extrusion of plastic. Nickel-based alloys that have shown themselves to be compatible with inlaid barrel liners by virtue of similar wear ratios, modulus of elasticity, ultimate yield strength, and linear thermal coefficients of expansion, are sprayed at high velocity onto a heated feed screw to mechanically bond the alloy to the feed screw. The alloy is then fused to the feed screw in a controlled manner. Following the fusing process, the feed screw and alloy thereon is heated and allowed to cool in a highly controlled environment to produce a crack-free dense coating of the alloy on the screw substrate.

Abstract: A method of the thermally spraying a solid lubricant (i.e. graphite or BN) impregnated metal matrix onto a metal target, using the steps of: (a) creating a flame or arc into which a consummable strand is fed, the strand being constituted as a hollow sheath of metal and a core therein comprising essentially solid lubricant powder particles, the flame or arc melting the metal of such strand; (b) applying a pressurized jet of atomizing gas to the melt and included graphite particles to project a spray of molten heavy metal and graphite particles generally homogeneously distributed throughout such spray, said graphite being protected against ablation during transit from the flame or arc to the target; and (c) surface heat treating essentially only the deposit to precipitate additional graphite while densifying the metal and controlling microstructure.

Abstract: A tungsten chromium carbide-nickel coated article and process for producing it in which the coating contains chromium-rich particles having at least 3 times more chromium than tungsten and wherein said chromium-rich particles comprise at least about 4.5 volume percent of the coating.

Abstract: Disclosed is a developer sheet useful in forming reproductions having a glossy finish, or in forming transparencies comprising:a support having a layer of a finely divided, thermoplastic, developer material on the surface thereof, said developer material being capable of reacting with a color precursor to produce a visible image and being capable of coalescing into a thin film which imparts gloss to said image upon application of heat and/or pressure, and having a surfactant admixed within said layer of developer material to aid in the coalescing of said developer material into a thin film.

Abstract: A process for manufacturing a metallized polymeric film to provide a structure possessing high metal-to-film adhesion and little, if any, tendency toward metal fracture is disclosed. In one embodiment of the process, at least one polyolefin layer is provided to a film which includes a substantially isotactic polymer having a degree of atacticity of no more than about 6%. The isotactic component is preferably polypropylene homopolymer. Other components include up to about 34% of an adhesive-promoting component which can be a C.sub.2 -C.sub.4 polymer, including homo-, co-, and terpolymers having C.sub.2 -C.sub.4 carbon chains, and a second isotactic polymer having a degree of atacticity of from about 6% to about 15%. The surface of the polyolefin layer is subjected to flame treatment followed by vacuum metallization of this surface (preferably with aluminum).

Abstract: A method is provided for improving the adhesion of a substrate material which does not form stable bonds to a bondable material by applying high energy bondable ions to the surface of the substrate to create an interface alloy layer and then adhering a bondable material to the surface of the substrate material. The high energy ions used may be meal ions. Before adhering, the thickness of the interface layer may be increased to form a layer utilizing conventional processes such as flame spray, plasma spray or D-gun spray. Additionally, the method may be used to join similar or dissimilar first and second substrate materials.

Abstract: A process for forming a deposition film on a substrate comprises introducing separately a precursor or activated species formed in a decomposition space (B) and activated species formed in a decomposition space (C), into the deposition space wherein the film is formed on the substrate.

Abstract: The present invention provides a method of treating a SIMOX wafer so that oxygen precipitates and heavy metal, carbon, and other contaminants are substantially reduced. The method includes forming a protective layer on the SIMOX surface, heating the wafer and protective layer so that the precipitates and contaminants disolve and diffuse into the protective layer, and slowly cooling the wafer to permit continued diffusion during cooling.

Abstract: Methods are described for making a mirror useful in reflecting high energy laser radiation. The mirrors are comprised of an intermediate coating layer applied to the mirror substrate and a reflective coating layer applied to the intermediate layer. Plasma spray techniques are used to apply a readily polishable intermediate coating layer at high deposition rates.

Abstract: Hard facing of iron and iron base alloy substrates is disclosed using a hard facing material containing vanadium carbide and a flux composition containing nickel boron or calcium silicon. The nickel boron is used in amounts ranging from about 1 to 3% by weight of the mixture while the calcium silicon is used in amounts ranging from about 0.1 to 0.5% by weight of the mixture.

Abstract: Seafood pots made of wire mesh netting are prepared for galvanizing by first passing them through an incineration chamber to burn, melt and loosen foreign material thereon, and then passing them through a high pressure liquid spray to remove residual burned matter and loosened foreign material. The pots are then ready to be passed through the steps of the galvanizing process, which includes dipping the pots into heated preflux before they are dipped into molten zinc. An inverted drying chamber bridges the distance between the preflux tank and the zinc kettle, through which the seafood pots are moved by conveyor means to dry the preflux, with drying heat within the chamber being drawn from the tank and the kettle. The seafood pots are vibrated as they are withdrawn from the molten zinc to effect an even coating of zinc on the wire mesh netting thereof.

Abstract: In the preferred embodiment, a method is presented for filling depressions in fabricated steel surfaces by applying a metallic body solder consisting of 15 to 20 weight percent copper, 2 to 3 weight percent zinc and the balance tin. The body solder alloy is heated to a temperature above about 210.degree. C. to form a workable thixotropic paste that is applied with spreading onto the steel surface. Upon cooling, the body solder forms a dense, tightly adherent fill that is grindable and paintable in conjunction with the surrounding steel surface.

Abstract: An oxygen gas analyzer is provided having a solid-electrolyte partition wall generating a detection signal proportional to the difference between the oxygen concentrations on each side of the wall. Electrode films attached to each side of the wall are comprised of a metal powder having a particle size which becomes gradually smaller toward the partition wall. Platinum screens are bonded to the electrode films and leadwires are welded to the platinum screens for providing a detection signal therethrough. Advantageously, this structure provides improved bonding strength between the electrode films and the leadwires while also providing a short response time.

Abstract: A method and apparatus utilized in conjunction with a wire galvanizing apparatus assures a bright finish on the coated wire. This method and apparatus includes passing the wire through a water quenching bath immediately following the emergence of wire from the molten zinc galvanizing bath of a conventional galvanizing apparatus. A pair of pressure pads grips the wire at its entrance to the water quenching bath for substantially sealing the water quenching bath against water leakage into the adjacent molten zinc galvanizing bath. A heating apparatus is directed at the wire prior to its entrance to the pressure pads to assure that the zinc coating is still in a molten condition as the wire enters the water quenching bath.

Abstract: The method of the invention employs a gas torch which has the feature of selective addition of metal powder to the gas flow, in a cyclical pattern of metal-spraying and non-spraying (fusing) utilization of the same torch. The torch is caused to make short and relatively rapid transverse oscillations of sweep across the width of a swath along the workpiece, the swath developing in the course of a relatively slow feed (e.g., a longitudinal feed) of the torch with respect to the workpiece. The rate of torch feed and the duty cycle of metal application (vs. non-spraying) are related to the effective width of the metal "bead" thus sprayed, so as to assure (1) overlapping of adjacent beads and (2) fusing of adjacent beads to each other and to the workpiece.

Abstract: A method and apparatus utilized in conjunction with a wire galvanizing apparatus assures a bright finish on the coated wire. This method and apparatus includes passing the wire through a water quenching bath immediately following the emergence of wire from the molten zinc galvanizing bath of a conventional galvanizing apparatus. A pair of pressure pads grips the wire at its entrance to the water quenching bath for substantially sealing the water quenching bath against water leakage into the adjacent molten zinc galvanizing bath. A heating apparatus is directed at the wire prior to its entrance to the pressure pads to assure that the zinc coating is still in a molten condition as the wire enters the water quenching bath.

Abstract: Introduction of boron as a hardening agent for metal hard-facing and the like is achieved by way of welding practices involving a consumable slender rod or wire filler member of relatively ductile material into the surface of which boron has been diffused to leave relatively brittle boride about a relatively ductile core, the slender borided welding filler member lending itself to uncomplicated handling because of core ductility while at the same time exhibiting a high percentage of borided material from which a hard facing can be developed when it is melted and bonds with metal of a body which is to be hard-faced.

Abstract: A method of producing a hot-dip galvanized steel strip having a uniform zinc-iron alloy coating on one surface and a formable hot-dip metallic zinc coating on the opposite surface which comprises forming a thin uniform hot-dip metallic zinc coating which has a coating weight less than 0.10 ounces per square foot on one side and a heavier metallic zinc coating on the opposite surface and passing the coated strip through a chamber having heating means and cooling means therein, said heating means, such as gas jets, adapted to apply heat directly only to the thin zinc coated side of the strip to convert the thin zinc coating into a fully alloyed zinc-iron coating, and said cooling means, such as air jets, adapted to blow cooling air onto the heavier zinc coating to effect rapid cooling thereof while the thin zinc coated side is being heated; thereby preventing formation of a thick zinc-iron intermetallic subsurface layer on the heavier coated side.

Abstract: An improvement for the flame spray process in which a heat-fusible self-fluxing material is heated in a heating zone to at least heat-softened condition and propelled in such condition out of said zone in finely divided form onto an obscure substrate surface of a base article. An obscure substrate surface may be such that conventional fusing techniques are not suitable for use in final bonding of the flame spray material to the substrate. The invention includes the use of an ordinary commercial soluble silicate solution applied to the coated substrate surface, solidified by furnace fusing, and removed by attrition to provide a base article which may be further processed to predetermined dimensional tolerances.

Abstract: Equipment used in a substantially water free, but corrosive environment is protected from corrosion by coating only certain welded parts thereof with a metal more base than the metal part coated.

Abstract: Glass is heated to a temperature of at least about 400.degree. C. and contacted sequentially with a silane-containing gas and an organometallic composition which thermally decompose to form, respectively, a coating layer of silicon and a coating layer of metal oxide on the glass surface. The resultant coated glass article is more durable than a silicon coated glass article and has better solar energy control properties than a metal oxide coated glass article.

Abstract: Powdered binder metal and hard metal granules are deposited in measured quantities on the cutting edge of a metal blade. When these materials both have a magnetic component, an electromagnet with an elongated air gap is used to pick up quantities determined by the amount of exciting current and to deposit them on the surface to be coated. A high-frequency heating current flows through the object being coated and also through a nearby inductor in series. This produces a short heating cycle in which the binder metal is melted, this being done in a protective gas atmosphere and without the presence of a flux. The object to be coated is held in a clamping device provided with a cavity around the surfaces to be coated, which include adjacent side surfaces as well as the edge of the blade, and the clamping plates also operate as heat sinks. The method and apparatus can also be used for sintering on a coating, but that requires a longer heating cycle.

Abstract: A process for preparation of an activated or sensitized polyimide polymer, deposition of various catalysts on the sensitized polymer and subsequent plating on said sensitized and catalyzed surface of a metal, e. g., nickel, cobalt, copper, or gold from an electroless bath; improved adhesion, avoidance of blistering, etc. are observed; the process is capable of producing useful printed circuits such as for mounting integrated circuit chips.

Abstract: A wear-resistant bearing material, and process for making it, comprising hard phase particles, such as Al.sub.2 O.sub.3, substantially uniformly dispersed in a plasma deposited or detonation gun deposited soft ductile metal matrix, such as aluminum bronze, and wherein said particles are sized between about 0.05 microns and about 100 microns, and present in a volume fraction of between about 3% and 50%.