Showing papers on "Coating published in 1994"

Partially coated electrodes

Abstract: A partially coated electrosurgical electrode has a portion of a medical grade metallic material as a substrate for energy application. Conductive of sites of metallic material or alloys thereof pass energy through peaks that define valleys nearby. A partial coating in the valleys has a low surface free energy. A treated surface across the peaks and generally over the filled valleys is relatively smooth for non stick characteristics during application of electrosurgery to tissue and bodily fluids. Openings in the treated surface through the partial coating are at the peaks of conductive sites to expose the metallic material or alloys thereof. The partial coating is a fluorinated polymer. The treated surface is a relatively even level that is not flat. The metallic material substrate is an alloy of stainless steel or nickel chrome. A mechanically deformed surface finish, plasma or vapor deposition on the substrate forms the conductive sites. A method of manufacturing the electrode has steps including preparing it the metallic conductor, making it with the conductive material having peaks above the valleys as conductive sites, applying the partial coating to it and treating the surface across the peaks and generally over the filled valleys of the partially coated electrically conductive electrode. Locating the openings among the valleys is a step. Treating may be mass finishing, such as vibratory or tumbling the partially coated electrodes with or without abrasive material media or polishing, buffing, surface grinding, abrasive belt grinding or sanding with abrasive material. Making the peaks and valleys can be by stamping, coining, burnishing, embossing, threading, tumbling, vibrating, shot peening, wire brushing, grit blasting, thermal spraying, with powder, with wire supplied to melt and be distributed, or with high velocity oxygen fuel and a nickel, cobalt alloy, stainless steel or a nickel chrome alloy. A manufacturing method for the electrode has coating a strip of metal with the low surface energy polymer and forming it in a stamping operation with a raw edge metal edge.

Protective coatings in the gas turbine engine

Abstract: The gas turbine provides one of the hardest environments challenging material systems today. Engine components are subject to rigorous mechanical loading conditions, high temperatures, and corrosive or erosive media. Historically, engine manufacturers have applied protective coatings to increase the durability and field performance of alloys or composites. Field experience as well as the development of processing technologies has led to the evolution of many new and improved coatings systems for a variety of engine component applications. In the fan and compressor areas, erosion-resistant coatings are used to minimize blade wear, antigallant coatings are used for fretting wear of blade root attachments and corrosion-resistant coatings are used for blade and disk materials. In the case of the combustor and turbine areas, diffusion and overlay coatings have been developed for oxidation and/or corrosion resistance and ceramic coatings are used widely as thermal barriers. In this paper, we shall review the current state of the art for coating technology in gas turbine engine applications with a look towards future needs and directions.

Method of making catheter

Abstract: A method of making hand-actuated retention catheter 5 is disclosed. The retention catheter includes a tube 12, an overcoat layer 14 encircling the tube 12 and a cavity 16 interposed between the tube 12 and the overcoat layer 14. The cavity 16 encircles the tube and includes a bulbous balloon portion 24 and an enlarged fluid reservoir portion 22 interconnected and separated by a catheter sleeve portion 26 which has a narrowed outside diameter. The expandable balloon portion 24 can be expanded by compressing the fluid reservoir portion 22. A variabale thickness coating of bond-preventing agent is formed on a polymeric structure prior to dipping in a polymeric material to form the overcoat layer.

Sandblasting and silica coating of a glass-infiltrated alumina ceramic: Volume loss, morphology, and changes in the surface composition☆

Abstract: Silica coating can improve bonding of resin to glass-infiltrated aluminum oxide ceramic (In-Ceram), and sandblasting is a pretreatment to thermal silica coating (Silicoater MD system) or a tribochemical coating process (Rocatec system). This study evaluated the effects of sandblasting and coating techniques on volume loss, surface morphology, and surface composition of In-Ceram ceramic. Volume loss through sandblasting was 36 times less for In-Ceram ceramic compared with a feldspathic glass ceramic (IPS-Empress), and sandblasting of In-Ceram ceramic did not change its surface composition. After tribochemical coating with the Rocatec system, a layer of small silica particles remained that elevated the silica content to 19.7 weight percentage (energy-dispersive spectroscopy). Ultrasonic cleaning removed loose silica particles from the surface and decreased the silica content to 15.8 weight percentage, which suggested firm attachment of most of the silica layer to the surface. After treatment with the Silicoater MD system, the silica content increased only slightly from that of the sandblasted specimen. The silica layer created by these systems differs greatly in both morphology and thickness, which could result in different bond strengths. Sandblasting of all ceramic clinical restorations with feldspathic glass materials should be avoided, but for In-Ceram ceramic the volume loss was within an acceptable range and similar to that of noble metals.

Coatings Tribology: Properties, Techniques and Applications in Surface Engineering

Abstract: Surface coating methods tribology of coatings tribological properties of coatings coating characterization and evaluation coating selection applications.

Silicone rubber particles coated with silicone resin

Abstract: Proposed is a powder of silicone rubber having improved flowability and dispersibility consisting of particles of a cured silicone rubber of which each particle has a coating layer of a polyorganosilsesquioxane resin in a specified coating amount. The powder is prepared by the admixture of an aqueous dispersion of a cured silicone rubber particles, which is preferably prepared by the hydrosilation reaction between a vinyl group-containing organopolysiloxane and an organohydrogen polysiloxane emulsified in an aqueous medium, with a trialkoxy silane compound such as methyl trimethoxy silane together with an alkaline compound, e.g., ammonia water, under agitation so that the hydrolysis-condensation reaction of the trialkoxy silane compound proceed to form a coating layer on the surface of the silicone rubber particles.

Anti-microbial materials

Abstract: Anti-microbial coatings and powders and method of forming same on medical devices are provides. The coatings are preferably formed by depositing an anti-microbial biocompatible metal by vapour deposition techniques to produce atomic disorder in the coating such that a sustained release of metal ions sufficient to produce an anti-microbial effect is achieved. Preferred deposition conditions to achieve atomic disorder include a lower than normal substrate temperature, and one or more of a higher than normal working gas pressure and a lower than normal angle of incidence of coating flux. Anti-microbial powders formed by vapour deposition or altered by mechanical working to produce atomic disorder are also provided. The anti-microbial effect of the coatings or powders may be further activated or enhanced by irradiating with a low linear energy transfer form of radiation such as gamma radiation. Novel anti-microbial silver materials are defined, characterized by having a positive rest potential, a Trec/Tm less than 0.33, and a grain size less than 200 nm. Anti-microbial fine grain or nanocrystalline materials are provided, together with methods of preparation, wherein the anti-microbial metal if deposited in a matrix with atoms or molecules of a different material such as other biocompatible metals (ex. Ta), trapped or absorbed oxygen, or compounds of anti-microbial metals or biocompatible metals (ex. Ag0 or TaO). The invention also extends to a method of producing an anti-microbial effect with silver materials that form complex silver ions other than Ag?+, Ag2+ and Ag3+?.

Drug incorporating and releasing polymeric coating for bioprosthesis

Abstract: In accordance with the present invention, there are provided prosthetic articles having polyurethane coatings with biologically active compounds incorporated within the interstices of the polymer. Methods for the preparation of such articles are also provided. Thus, a polyurethane coating is applied to a prosthetic article, the coating then swelled (without significantly dissolving the polymer) so that substantial quantities of biologically active compounds can be incorporated within the interstices of the polymer. Upon long term exposure of a prosthetic article of the invention to physiological conditions, the biologically active compound is slowly released by the treated polymer. The biologically active compound is, therefore, released only at the site where it is desired, i.e., where the prosthetic article is positioned.

Environmental durability of glass-fiber composites

Abstract: Durability of glass-fiber/polymer composites is dictated by the durability of the components: glass fiber, matrix, and the interface. Environmental attack by moisture, for example, can degrade the strength of the glass fiber; plasticize, swell, or microcrack the resin; and degrade the fiber/ matrix interface by either chemical or mechanical attack. The relative rates of these degradation processes are a function of the chemistry of the resin, temperature, length of time of exposure, degree of stress (whether cyclic or static), chemistry and morphology of coating of coupling agent on the glass fiber, and type of glass fiber. Several examples illustrate how the chemistry and morphology of the coatings of coupling agents that are on the glass fiber influence the strength and durability of the interfacial region.

Study of the surface characteristics of magnetron‐sputter calcium phosphate coatings

Abstract: Plasma-sprayed hydroxylapatite coatings on metals such as titanium have been investigated for many years and have shown a good biocompatibility when implanted in bony tissues. Radiofrequency magnetron sputtering was used as an alternative method to deposit thin films of hydroxylapatite on titanium substrates. X-ray diffraction demonstrated that the sputtered layer was crystalline with a preferred (001) crystallographic orientation with the C-axis perpendicular to the substrate surface. Scanning electron microscopy showed that the deposited films had a uniform and dense structure. The calcium phosphate ratio varied between 1.5 and 2.0, as determined by energy-dispersive X-ray analysis. The in vitro dissolution appeared to be determined by the degree of the coating's crystallinity. © 1994 John Wiley & Sons, Inc.

Immediate release tablet cores of insoluble drugs having sustained-release coating

Abstract: A controlled release tablet for oral administration is disclosed which has a tablet core including an insoluble therapeutically active agent having an aqueous solubility of less than or equal to about 5 mg/ml in a sufficient amount to render a therapeutic effect. The core provides rapid release of said therapeutically active agent upon exposure to aqueous solutions. The tablet core is coated with a controlled release coating permitting sustained release of said therapeutically active agent when said coated tablet is exposed to aqueous solutions.

Controlled-release formulations coated with aqueous dispersions of ethylcellulose

Abstract: A stabilized solid controlled release formulation having a coating derived from an aqueous dispersion of a hydrophobic polymer is obtained by overcoating a substrate including an active agent selected from the group consisting of a systemically active therapeutic agent, a locally active therapeutic agent, a disinfecting and sanitizing agent, a cleansing agent, a fragrance agent and a fertilizing agent, with an aqueous dispersion of the plasticized hydrophobic polymer and then curing the coated substrate at a temperature above the glass transition temperature of the plasticized hydrophobic polymer, until a curing endpoint is reached at which the coated substrate provides a stabilized dissolution of the active agent which is unchanged after exposure to accelerated storage conditions, the endpoint being determined by comparing the dissolution profile of the formulation immediately after curing to the dissolution profile of the formulation after exposure to accelerated storage conditions of at least one month at a temperature of 37°C and at a relative humidity of 80%.

Process for producing non-volatile memory devices having closely spaced buried bit lines and non-overlapping code implant areas

Abstract: This inventions provides a method to form metal lines with smaller line pitches than is possible using the conventional photolithographic single coating process. This invention provides for a double photolithographic process where the surface is coated, exposed and developed twice to form two sets of resist patterns. These resist patterns are used to form metal lines over all the buried bit lines. These metal lines provide better masking of the bit lines from the code implants thereby reducing bit line resistance and increasing ROM read speed.

Matrix coating for sensing surfaces capable of selective biomolecular interactions, to be used in biosensor systems

Abstract: A matrix coating suitable for use in a biosensor is provided. This matrix coating comprises a hydrogel bound to a surface and via which a desired ligand can be bound. This hydrogel is activated to contain charged groups for bringing about the concentration of biomolecules carrying an opposite charge to that of said charged groups, and reactive groups for covalently binding the biomolecules concentrated to the matrix coating.

Durable low-emissivity solar control thin film coating

Abstract: An infrared reflecting interference filter capable of transmitting a desired proportion of visible radiation while reflecting a large portion of incident solar radiation is provided. The filter consists of a transparent substrate coated first with a dielectric layer, next a partially metal reflectance layer, and finally an outer protective dielectric layer. In addition, between each metal-dielectric interface is deposited a nucleation or glue layer that facilitates adhesions and improves chemical and mechanical resistance. The interference filters are durable and can be modified to provide a full range of optical and electrical characteristics. The dielectric layer can comprise of composite films consisting of silicon nitride in combination with zirconium nitride, titanium nitride, and/or hafnium nitride.

Formation of carbon films on carbides under hydrothermal conditions

Abstract: CARBON films find applications in a wide range of fields, ranging from microelectronics to materials science1. In ceramic matrix composites they confer the high strength and toughness needed for applications in aerospace, nuclear and automotive engineering2. Chemical vapour deposition is traditionally used to prepare carbon films, but it is relatively expensive, and not easily adapted to coating samples in the form of whiskers, platelets or powders. Here we report that silicon carbide, the most common component of composite ceramics, can be coated with carbon films of nanometre to micrometre thickness by hydrothermal treatment at 300–800 °C. We have applied the technique to SiC fibres, powders, platelets and single crystals, as well as to other carbides. Our method should provide a general and inexpensive route to high-toughness composites and lubricating coatings.

Photocatalyst composite and process for producing the same

Abstract: A photocatalyst composite is provided which comprise a substrate having particles of a photocatalyst such as titanium oxide, adhered thereon via a less degradative adhesive such as a fluorinated polymer comprising a copolymer of a vinyl ester and/or vinyl ether and a fluoroolefin, or a silicon based polymer or cement. Furthermore, a process for producing the photocatalyst composite and a coating composition containing the photocatalyst composite are provided.

Packaging material for thin film lithium batteries

Abstract: A thin film battery including components which are capable of reacting upon exposure to air and water vapor incorporates a packaging system which provides a barrier against the penetration of air and water vapor. The packaging system includes a protective sheath overlying and coating the battery components and can be comprised of an overlayer including metal, ceramic, a ceramic-metal combination, a parylene-metal combination, a parylene-ceramic combination or a parylene-metal-ceramic combination.

Abrasive articles and methods of making and using same

Abstract: An abrasive article is presented which includes a backing having a front and back surface, and an abrasive coating bonded to the front surface of the backing The abrasive coating comprises a homogeneous mixture of a plurality of abrasive particles, a binder and a grinding aid The binder serves to bond the abrasive coating to the backing and the grinding aid comprises at least 1 % by weight of the abrasive coating, but not more than 50 % by weight It is preferred that the abrasive coating consists essentially of a plurality of precisely shaped abrasive composites Methods of making and using the abrasive articles are also presented

Process for improving impact resistance of coated plastic substrates

Abstract: A process for improving the impact resistance of a coated plastic substrate, particularly those polymers having a high refractive index, comprising applying an aqueous polyurethane dispersion as a primer layer to at least one surface of the plastic substrate, at least partially curing the aqueous polyurethane dispersion by air drying at ambient temperature, applying a coating composition over the polyurethane primer layer, and curing the coating composition to form an abrasion resistant hard coat. Preferably, the aqueous polyurethane dispersion is air dried at ambient temperature for less than one hour before application of the abrasion resistant coating composition. The process provides an impact enhancing, abrasion resistant coating system having strong interfacial adhesion that is preferably transparent for application onto preferably transparent plastic articles, such as ophthalmic lenses and safety eye wear.

Kinetics and Mechanisms of Oxidation of 2D Woven C/SiC Composites: I, Experimental Approach

Abstract: The oxidation behavior of a 2D woven C/SiC composite partly protected with a SiC seal coating and heat-treated (stabilized) at 1,600 C in inert gas has been investigated through an experimental approach based on thermogravimetric analyses and optical/electron microscopy. Results of the tests, performed under flowing oxygen, have shown that the oxidation behavior of the composite material in terms of oxidation kinetics and morphological evolutions is related to the presence of thermal microcracks in the seal coating as well as in the matrix. Three different temperature domains exist. At low temperatures ( 1,100 C), such diffusion mechanisms are limited by sealing of the microcracks by silica; therefore, the degradation of the composite remains superficial. The study of the oxidation behavior of (i) the heat-treated composite in a lower oxygen content environment (dry air) and (ii) themore » as-processed (unstabilized) composite in dry oxygen confirms the different mechanisms proposed to explain the oxidation behavior of the composite material.« less

Review of CVD TiN coatings for wear-resistant applications: deposition processes, properties and performance*

Abstract: Titanium nitride (TiN) deposited by chemical vapor deposition (CVD) techniques has been the premier wear-resistant coating in many applications for the last several decades. This review presents a history of developments in the technology of CVD TiN coatings. The CVD processes and equipment are discussed and the current knowledge on the thermodynamics and kinetics of the deposition process is presented. Various properties of CVD TiN coatings, such as hardness, adhesion, morphology and frictional properties, are discussed in the context of applications where wear resistance is required. Particular emphasis is given to applications in metal cutting where TiN has remained the mainstay of the various new and recent developments in coating design for cutting tools. Recent results of correlation between machining performance, deposition parameters, coating morphology and properties are presented. Throughout the paper, gaps in the existing understanding of the technology are pointed out. Finally, the paper presents a glimpse into the future of CVD TiN technology for wear-resistant applications.

Material-tissue interfaces: the role of surface properties and processes.

Abstract: The introduction of a foreign material into living tissue--intentionally as in biomedical applications (implants, protheses, drugs) or unintentionally as when minerals or fibers are inhaled--results in the creation of interfaces between the material and the surrounding tissue. This article identifies and discusses the possible role of material surface properties and molecular processes occurring at such interfaces. For kinetic and thermodynamic reasons, surfaces are different from the corresponding bulk of the material, and contain reactive (unsaturated) bonds, which in turn lead to the formation of surface reactive layers (e.g., surface oxides on metals) and adsorbed contamination layers. The encounter with the biological environment leads to further surface reactions modifying the surface, and to the adsorption of water, ions, and biomolecules, which are continuously exchanged. The exact nature of the dynamic, adsorbed water, ions, and biomolecule coating in turn influences the behavior of cells approaching the material surface, and hence the tissue response.

Process and apparatus for ashing treatment

Abstract: A process and apparatus for the ashing treatment in which a plasma generated by activating a gas containing at least oxygen is applied to a material to be treated, on which a coating film of an organic is formed, through a plasma-transmitting plate for capturing charged particles in the plasma and allowing the transmission of neutral active species, to thereby ash the coating film of the organic substance. The material to be treated is placed at a position at which charged particles of a high energy, which have been transmitted through the plasma-transmitting plate without being captured by the plasma-transmitting plate, impinge thereon together with the neutral active species which have been transmitted through the plasma-transmitting plate. Also, the ashing treatment process and apparatus includes a distance-adjusting device for adjusting the distance between the plasma-transmitting plate and the material to be treated, by changing the position of the material to be treated.

Method of forming coating film and apparatus therefor

Abstract: An apparatus for forming a coating film, comprises a spin chuck for supporting a substrate with one surface facing upward and rotating the substrate about a vertical axis, a first nozzle for supplying a solvent of a coating solution on the substrate, and a second nozzle for supplying the coating solution on a central portion of the substrate. The first and second nozzles are supported by a head such that the supported nozzle moves between a dropping position above the substrate and a waiting position offset from the substrate. The solvent and coating solution are diffused along the surface of the substrate by rotating the spin chuck.

Coated abrasive article incorporating an energy cured hot melt make coat

Abstract: A coated abrasive article comprises a backing, a first binder on the backing, and a plurality of abrasive particles in the first binder. The first binder is a hot melt pressure sensitive adhesive that is energy cured to provide a crosslinked coating. The invention also relates to a method of producing such articles.

Heat-treatment convertible coated glass and method of converting same

Abstract: A high performance, durable sputter coated, heat-treatable glass which after heat-treatment exhibits about 76% or more visible transmittance, a hemispherical emissivity (E h) of about 0.16 or less, and a normal emissivity (E n) of about 0.12 or less is formed by sputter coating a layer system on a glass substrate which includes an undercoat and overcoat of Si3N4, a silver layer, and two nickel or nichrome layers on opposite sides of the silver layer, and wherein the lower nickel-based layer is about three times as thick as the other nickel based layer. The increased thickness of the lower nickel-based layer allows the coated glass article to be both heat-treatable, and "low-E' after the heat-treatment. This allows matching with other known glasses in the family of layer components by way of the heat-treatment process. The layer system employed allows, even if not matchable to another glass, for the sputter coating operation to include the coating of other members of the family of coating without change of targets, efficient use of the coater targets that exist, and minimal operational changes during production.