Showing papers on "Coating published in 1990"

Gas-dynamic spraying method for applying a coating

Abstract: A cold gas-dynamic spraying method for applying a coating to an article introduces into a gas particles of a powder of a metal, alloy, polymer or mechanical mixture of a metal and an alloy, the particles having a particle size of from about 1 to about 50 microns The gas and particles are formed into a supersonic jet having a temperature considerably below a fusing temperature of the powder material and a velocity of from about 300 to about 1,200 m/sec The jet is directed against an article of a metal, alloy or dielectric, thereby coating the article with the particles

Rhenium-containing protective coating with high corrosion and oxidation resistance

Abstract: The present invention relates to a corrosion-resistant or oxidation-resistant coating for metallic components, in particular gas turbine components of superalloys based on nickel or cobalt. By adding rhenium, the life of protective coatings, in particular of the MCrAlY type, under corrosive or oxidising conditions can be increased. The protective coating according to the invention contains, in addition to certain selected components and impurities, the following components (in percent by weight): 1 - 20%, prefeably 4 - 10%, of rhenium, 22 - 50% of chromium, 0 - 15% of aluminium, the amount of chromium and aluminium together being at least 25% and not more than 53%, 0.3 - 2% of yttrium and 0 - 3% of silicon, the remainder mainly being at least one of the elements selected from iron, nickel and cobalt, preferably one of the elements selected from nickel and cobalt. Protective coatings qualified for certain applications can be considerably improved with regard to the life under corrosive conditions by adding even smaller amounts of rhenium.

Apatite coating on ceramics, metals and polymers utilizing a biological process

Abstract: A novel method of apatite coating is presented. The main characteristics of the method are that the apatite layer obtained consists of bone-like apatite and can be coated on various substrates including ceramics, metals and organic polymers. Coating is carried out in a simulated body fluid, the ion concentrations, temperature and pH of which are adjusted to almost equal to those of human blood plasma, using a plate of CaO, SiO2-based glass as a source of nucleating agent of apatite on the surfaces of substrates. The apatite layer obtained, formed in a similar environment to that in the body, is thus expected to show higher bone-bonding ability than that formed by conventional methods, and this method is applicable to various materials having different mechanical properties.

Article having non-crosslinked crystallized polymer coatings

Abstract: A non-crosslinked crystallized polymer or polymer blending coating is disclosed for articles that come into contact with bodily fluids. The polymer or polymer blend to be used is crystallizable and is stable in the presence of water at temperatures of up to about 60° C. when in the crystalline state. The polymer or polymer blend is dissolved in a solvent, such as water or dimethyl sulfoxide (DMSO), and is coated on the article. The polymer coating is then crystallized, generally by heat treatment, providing both toughness and increased adherence of the coating to the article without ready dissolution when the article comes into contact with fluids.

New developments in the modelling of the hardness and scratch adhesion of thin films

Abstract: Both hardness testing and scratch adhesion testing are now routinely used for coating evaluation, although the fundamental understanding of both processes is somewhat limited. To establish the hardness of thin coatings independent of substrate, the volume-law-of-mixtures hardness model has been applied to a large number of coating/substrate systems, and extensions to an earlier model have been developed including better deforming volume calculations and the ability to obtain best-fit coating parameters. In order to extend the understanding of the scratch test, the statistical nature of coating failure has been investigated by counting the number of individual failures at a given load for a fixed scratch length. The results are analysed in terms of the Weibull distribution and these are related to the surface roughness of the substrate prior to coating. With increased surface roughness both the critical load and Weibull parameters are reduced, reflecting a change in the distribution of interfacial flaws.

Anti-infective and antithrombogenic medical articles and method for their preparation

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.

Heat-curable silicone compositions having improved bath life

Abstract: A curable organosilicon composition comprises a component having silicon-bonded hydrogen atoms, a component having silicon-bonded radicals reactive therewith, a curing catalyst, a catalyst-inhibitor and a bath life extender. The use of certain compounds, which are ineffective as a bath life extender in the absence of a catalyst inhibitor, effectively extend the room temperature bath life of a silicone coating composition containing a catalyst inhibitor. Being a substantial non-inhibitor for the catalyst the bath life extender component does not effect the cure time and/or cure temperature of the composition. This discovery has permitted the preparation of curable coating compositions which have a long bath life at room temperature and a rapid cure time at elevated temperatures which does not drift to longer intervals as the coating compositions ages over a typical production run. The room temperature cure times of the organopolysiloxane coating compositions of this invention are adequately long, and their cure times at elevated temperature are advantageously brief, that they are useful in fast-paced coating operations, such as adhesive release coating operations wherein the cured coating is further coated with an adhesive in-line, i.e., immediately after being cured.

Perimeter coated, electro-optic mirror

Abstract: An electro-optic mirror of the type having an electro-optic cell or medium with a transmittance which is variable upon the application of an electric field includes a perimeter coating applied to a front or rear surface of a substrate element for concealing any seal and/or electrical connections for the elctro-optic cell or meidum. The perimeter coating may be reflective to increase the field of view in the mirror and allow use of smaller cases or retaining bezels. Alternately, the perimeter coating may be opaque and nonreflective such as black frit, paint or lacquer. In either case, the coating may also be electrically conductive to substantially encircle an electrically conductive layer on the substrate and evenly distribute electric current to the electro-optic cell or medium for enhanced coloration response. The perimeter coating may be used with either a single, optically transparent mirror substrate including solid-state electro-optic cell or a laminate mirror assembly including spaced, optically transparent substrates with an electro-optic medium confined therebetween. Alternately, the laminate assembly includes a seal between said substrate elements which is either dark or color matched to the surrounding rim/bezel providing a border of uniform color around the assembly perimeter.

Longitudinally compliant vascular graft

Abstract: A longitudinally compliant PTFE graft (20) is provided by compressing at least a portion of a porous PTFE tube (32) along its longitudinal axis (22) and coating at least the outer wall of the compressed portion of the PTFE tube (32) with a biocompatible elastomer for allowing the compressed portion of the tube (32) to be stretched along the longitunal axis (22). The PTFE tube (32) is compressed by pulling the tube (32) over a cylindrical mandrel of like diameter and applying a compression force to the tube (32) along its longitudinal axis (22). The compressed portion(s) is(are) secured against movement upon the mandrel, and a coating (38) of liquified polyurethane or other biocompatible elastomer is then applied over at least the compressed portion(s) of the tube (32). The elastomeric coating (38) may be applied by dip coating or spray coating techniques. After the elastomeric coating (38) has dried, the completed graft (20) is removed from the mandrel.

Waterborne coating compositions for automotive applications

Abstract: A waterborne coating composition having a total solids content at application of greater than 30 percent, contains pigment and a dispersion of polymeric microparticles in an aqueous medium. The microparticles contain greater than 30 percent by weight based on the microparticles of a substantially hydrophobic polymer which is essentially free of repeating acrylic or vinyl units in the backbone, has a molecular weight greater than 300 and is adapted to be chemically bound into the cured coating composition. The aqueous medium of the microparticle dispersion is substantially free of water soluble polymer.

Spectrally selective mirror and method for making same

Abstract: A spectrally selective, glare-reducing mirror for vehicles which includes a substrate having a multi-layer coating on one side. The multi-layer coating includes a thin, transparent dielectric layer, preferably of titanium dioxide at a thickness of about 600-650 angstroms, and a very thin layer of metal, preferably of aluminum or silver, at a thickness of between about 25 and 150 angstroms. The dielectric layer is closest to a source of incident light to be reflected by the mirror. When applied to the rear surface of a transparent substrate such as glass, the metal layer may also be coated with light absorbing material such as paint for protection and reduction in unwanted reflections. In the preferred dielectric and metal thicknesses, a blue reflecting mirror results having a glare-reducing luminous reflectance between about 35% and 60%, while costs are reduced due to lesser required amounts of metal than in prior known mirrors.

Method for coated surgical instruments and tools

Abstract: A process for producing corrosion resistant and wear resistant medical tools and instruments by coating high strength low-carbon martensitic stainless steels with a thin, hard layer of refractory metal compound, preferably via cathodic arc plasma deposition technology The invention also covers the coated medical tools produced via such process

Process for the production of polyurethane coatings

Abstract: The present invention relates to a process for the preparation of a polyurethane coating by coating a substrate with a coating composition containing a) a polyisocyanate component and b) an isocyanate-reactive component containing at least one compound corresponding to the formula ##STR1## wherein X represents an organic group which has a valency of n and is inert towards isocyanate groups at a temperature of 100° C. or less, R 1 and R 2 may be identical or different and represent organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less, R 3 and R 4 may be identical or different and represent hydrogen or organic groups which are inert towards isocyanate groups at a temperature of 100° C. or less and n represents an integer with a value of at least 2, and curing the coating composition at a temperature of 100° C. or less.

A thermally insulating glass panel and method of construction.

Abstract: A thermally insulating glass panel (1), comprising: two spaced apart sheets of glass (2, 3) enclosing a low pressure space and interconnected by a peripheral joint (4) of fused solder glass and an array of pillars (5) having an exterior coating of fused solder glass.

Sustained-release pharmaceutical preparation

Abstract: A sustained-release pharmaceutical preparation comprising an admixture of uncoated and/or single walled water soluble drug, such as aspirin, and dual walled coated drug. The dual wall structure has an inner wall microencapsular control coating, such as ethyl cellulose, and an outer wall enteric coating such as cellulose acetate phthalate. The dual walled coated drug has a delayed, gradual, long-term release which takes place in the intestines while the uncoated and/or single walled drug has immediate therapeutic properties upon dissolution in the stomach. The outer wall enteric coating may be applied to microencapsulated core drug by a coacervation, spray coating or other process.

Lightfast colored polymeric coatings and process for making same

Abstract: A method of forming a colored polymer coating on a substrate is disclosed which comprises mixing a reactive polymer, a reactive colorant, and a linking agent, and reacting the linking agent with the reactive polymer and reactive colorant under suitable conditions to form the colored polymer coating. The polymer from which the coating is formed has reactive groups which can react with the linking agent. The reactive colorant has the general formula: R-[polymeric constituent-X].sub.n wherein R is an organic dyestuff radical; the polymeric constituent is selected from polyalkylene oxides and copolymers of alkylene oxides in which the alkylene moiety of the polymeric constituent contains 2 or more carbon atoms; n is an integer from 1 to about 6; and X is a reactive moiety. The linking agent has a reactive group capable of reacting with reactive groups in the polymer and a reactive group capable of reacting with the reactive moiety of the reactive colorant. A method of coating a substrate with a lightfast colored polymer finish is also disclosed which comprises forming a colored polymer coating on the substrate in accordance with the method described above and then overcoating the colored polymer coating with a second polymer layer containing an ultraviolet absorber. A composition comprising a mixture of the coating polymer, a reactive colorant, and a linking agent is also disclosed.

Geometries and configurations for magnetron sputtering apparatus

Abstract: A thin film coating system incorporates separate, separately-controlled deposition and reaction zones for depositing materials such as refractory metals and forming oxides and other compounds and alloys of such materials. The associated process involves rotating or translating workpieces past the differentially pumped, atmospherically separated, sequentially or simultaneously operated deposition and reaction zones and is characterized by the ability to form a wide range of materials, by high throughput, and by controlled coating thickness, including both constant and selectively varied thickness profiles.

Non-porous coated ptfe graft.

Abstract: A non-porous coated PTFE graft (20) includes a PTFE tube (32) having a conventional porous inner cylindrical wall (34) and a non-porous elastomeric coating (38) applied over at least a portion of the outer cylindrical wall (36) of the PTFE tube to render such portion of the outer cylindrical wall non-porous. The elastomeric coating is made of polyurethane or another biocompatible non-porous elastomer and precludes tissue ingrowth into the outer cylindrical wall, minimizes suture hole bleeding, and increases suture retention strength, while reducing the incidence of serious weepage. The elastomeric coating is preferably applied by mounting the PTFE tube upon a mandrel (68) of like diameter and either dip coating or spray coating all, or selected portions, of the PTFE tube with liquified polyurethane. After the polyurethane coating is completely dried, the non-porous vascular graft is removed from the mandrel and is ready for use.

Reduced first surface reflectivity electrochromic/electrochemichromic rearview mirror assembly

Abstract: A reduced first surface reflectivity electrochromic/electrochemichromic rearview mirror assembly provides improved glare reduction and substantially less noticeable double imaging. Preferably, the assembly includes an anti-reflective layer or coating on the outermost, front surface of the front glass substrate/panel. The coating can be a single thin film or a multiple layer thin film stack of suitable durability and index of refraction. Alternately, a gradient refractive index layer produced by surface leaching, dip coating and heating, or ion implantation may be used. The invention is especially useful in electrochemichromic mirror assemblies having a laminated front glass where unwanted total reflection and double imaging could otherwise be pronounced because of opportunities for nonparallel attachment of the multiple glass substrates.

Coating technology based on the vacuum arc-a review

Abstract: An overview of the current state of vacuum-arc-based coating technology is presented, with particular emphasis on defining those areas where further investigation would reap the greatest benefits. Particular attention is given to the 'continuous' cathodic arc, which is currently the best understood approach and which has been most successfully adapted for large-scale commercial coating in the United States. It is noted that the greatest promise of ion-based coating technology based on the vacuum arc is the potential for increased control over the coating process. Unlike the case for neutral coating atoms, the presence of a charge on coating ions gives a 'handle' to exert forces on them using electrostatic fields. One can in theory control the trajectory of these ions between the coating source and part to be coated. One can also control the energy with which they impact the substrate. It may even be possible to control the extent of their reactivity. >

Process for the preparation of coatings

Abstract: A process for the preparation of coatings using a coating composition having a binder containing a two-component system of a) a polyisocyanate component and b) an isocyanate-reactive component b) which is essentially free from hydroxyl groups and contains b1) 5 to 95 parts by weight of a polyamine containing ester groups and secondary amino groups and b2) 5 to 95 parts by weight of polyketimines.

Two-layer antireflective coating applied in solution

Abstract: A two-layer antireflective coating composition stacked on a substrate consisting of allyl diglycol carbonate polymer (CR-39) or glass and comprising a bottom layer containing less than 10% by weight of titanium dioxide equivalent weight and a titanium-free top layer containing polysiloxane resin; and a process for preparing said antireflective coating with improved adhesion on a substrate consisting of allyl diglycol carbonate polymer (CR-39) or glass. The thicknesses of each of said coating layers is in accordance with preselected equations, and the refractive indices of a said coating layers satisfy the following requirements: n.sub.s n.sub.t wherein n s represents the refractive index of the substrate consisting of allyl diglycol carbonate polymer (CR-39) or glass, n b represents the refractive index of the bottom layer, and n t represents the refractive index of the top layer.

Thermal barrier coating system with intermetallic overlay bond coat

Abstract: A thermal barrier coating system for high temperature superalloys includes an intermetallic bond coating on the substrate and a ceramic topcoat having a columnar grain structure with the columnar axis perpendicular to the surface of the coating. The intermetallic coating is preferably a nickel aluminide or a platinum aluminide, whose upper surface is oxidized during processing to form a thin layer of predominantly aluminum oxide. The ceramic topcoat is preferably zirconium oxide having from about 6 to 20 percent yttrium oxide.

Electrically conductive, light attenuating, antireflection coating.

Abstract: A coating for an article comprising layers of nitrides of certain transition metals to provide an electrically-conductive, light-attenuating, antireflection surface.

Multilayer coatings—influence of fabrication parameters on constitution and properties

Abstract: Multilayer TiC/TiB2 coatings were prepared by magnetron sputtering with various degrees of ion bombardment during deposition. In previous studies, it has been shown that a specific number of single layers, around 100 – 200 for a total layer thickness of 5 μm, produces optimum characteristics with regard to crack propagation resistance and wear behaviour, especially under interrupted cutting conditions. These are indications showing that cracks are deflected at the interface zones. These zones have an extension of about 2 – 3 nm after sputter deposition without “biasing” the substrate. Ion bombardment during deposition leads to similar interface zones, to modifications in the coating texture, and to the best coating properties being achieved at a larger number of single layers. Optimum properties and wear resistance were found for 500 single layers in a coating thickness of 5 μm. Constitution, properties and wear behaviour are discussed as a function of the fabrication parameters.

Fire barrier coating and fire barrier plywood

Abstract: A novel, non-combustible thin coating, applied as an air-setting paint, is used to form a coherent fire-barrier on or between susceptible wood or plastic substrates, or other substances. Consisting of a paint-like slurry of three separate but compatible and mutually synergistic co-bonding systems, viz. magnesium "oxychloride" cement, plus high alumina mono-calcium aluminate cement, plus colloidal silica dispersed in dimethyl formamide (DMF), and utilizing an aqueous solution of magnesium chloride as the common hydrating fluid for the two cements, the coating retains its structural integrity through prolonged exposure to flame temperatures of 2000° F. The coating takes advantage of its brilliant whiteness to act as a thermal radiation reflector for the high radiation component of most flames. Used alone, or in combination with structural reinforcing geotextiles, such as non-woven spunbonded polyester fabric, or woven and non-woven fiberglass or other natural or synthetic fabrics to form a laminate, the coating, while serving only transitorily as a heat barrier, effectively prevents the ignition of and flame spread of fire on the coated substrate. When placed between substrates at the partial sacrifice of the surface directly exposed to flame, it protects the back-substrate, and thus maintains structural integrity, as well as preventing the spread of flame to adjacent areas. The coating thus acts as a "fire-barrier" for which there are numerous applications.

Process for depositing optical thin films on both planar and non-planar substrates

Abstract: A rotary cylindrical sputtering system incorporates separate, separately-controlled linear magnetron sputter deposition and reaction zones for sputter depositing materials such as refractory metals and forming oxides and other compounds and alloys of such materials. In one aspect, the associated process involves rotating or translating workpieces past the differentially pumped, atmospherically separated, sequentially or simultaneously operated deposition and reaction zones and is characterized by the ability to form a wide range of materials, by high throughput, and by the ability to form durable optical quality thin films of nominal refractive indices and controlled coating thickness, including both constant and selectively varied thickness profiles.