Showing papers on "Coating published in 1988"

Physics and Applications of DIP Coating and Spin Coating

Abstract: Dip coating is a simple old way of depositing onto a substrate, especially small slabs and cylinders, a uniform thin film of liquid for solidification into a coating. The basic flow is steady, and in it film thickness is set by the competition among viscous force, capillary (surface tension) force and gravity. Thickness and uniformity can be sensitive to flow conditions in the liquid bath and gas overhead. The faster the substrate is withdrawn, the thicker the film deposited. This can be countered by using volatile solutes and combining rapid enough drying with the basic liquid flow. Then the physics grows more complicated, theoretical prediction of process performance more difficult, and control of the process more demanding. Outside product RD actually it is often modified.

Method of applying gel coating to plant seeds

Abstract: A new method of processing a plant seed wherein a coating treatment is applied to a plant seed with an aqueous alkali salt solution of an aqueous gel to form a coating layer thereon and said coating layer is reacted with an aqueous solution of a divalent or trivalent metal salt to render the coating layer insoluble to water. Particularly, the improvement is accomplished by encapsulating the plant seed in the above mentioned gel coating together with an air bubble. This encapsulation is performed by means of a nozzle having a telescopic structure, in which a plant seed and air is supplied through the inner passage while the gel is supplied the surrounding annular passage. The nozzle is used in a vertical orientation and the lower end performs a valve function to control the gel supply.

High speed process for coating substrates

Abstract: A high-speed process for coating substrates with thin organic coatings in a vacuum is disclosed and claimed. The process utilizes relatively low boiling, reactive monomers (e.g., polyacrylates) which are flash vaporized, condensed on the substrates and cured, in situ. The resultant cured films are pin-hole free and exhibit excellent adhesion. The process is capable of being run at very high coating and curing speeds, e.g., between 1 and 1000 cm/second.

Spherical granules having core and their production

Abstract: The spherical granules having a core coated with spraying powder containing a drug and low substituted hydroxypropylcellulose, because of their excellent hardness, can be coated further evenly, (e.g. sustained release coating, gastric coating, enteric coating), and at the time the granules are excellent in disintegration.

Wafer holding fixture for chemical reaction processes in rapid thermal processing equipment and method for making same

Abstract: A semiconductor wafer holding and support fixture having a low effective thermal mass comprises a planar surface having a recess for a wafer and consisting essentially of chemical vapor deposited silicon carbide. The wafer holder is specifically designed to isolate the wafer from regions of significant thermal mass of the holder. The wafer holder is particularly adapted for accomplishing chemical reactions in rapid thermal processing equipment in the fabrication of electronic integrated circuits. The method for making such an article comprises shaping a substrate, e.g. graphite, to provide a planar surface having a recess installing means for masking any regions of the substrate where silicon carbide is not desired, chemically vapor depositing a conformal outer coating of silicon carbide onto the substrate, removing the means for masking and removing the graphite by machining, drilling, grit-blasting, dissolving and/or burning.

Aqueous coating compositions

Abstract: A coating composition particularly adapted for can coatings is prepared by the addition polymerization of a monomer such as styrene in a reaction medium comprising a modified 1,2-epoxy resin The epoxy resin is modified by combining a portion of its 1,2-epoxy groups with epoxy-reactive groups of an ethylenically unsaturated monomer, and reacting others of its 1,2-epoxy groups with a tertiary amine and with a preformed addition polymer containing carboxyl groups to form an ionic, resinous composition containing sufficient carboxyl groups to render the coating composition self-dispersible in water in neutralized form

Pressure and contact sensor system for measuring dental occlusion

Abstract: A contact sensor for detecting points on a grid where the sensor is being contacted on opposing sides by teeth surfaces or other contacting points. The sensor is especially useful for measuring dental occlusion. The contact sensor includes two sets of parallel electrodes which are each formed on a thin, flexible supporting sheet. The electrodes are separated by a thin, pressure-sensitive resistive coating such as molydenum disulphide. Two such electrode structures are oriented at approximately right angles to create a grid where the intersecting electrodes cross separated by the resistive coatings. Several arrangements of resistive coating over electrodes as disclosed. In the absence of an external force, the material between the electrodes sets provides a high resistance between intersecting electrodes. The resistance between electrode intersections changes as pressure on opposite sides of the intersection changes. The sensor output is dynamic in that the resistance will vary as external pressure is repeatedly applied and removed. The sensor may be made extremely thin and can provide high resolution capable of distinguishing between contact points separated by 0.050 inches or less. A new circuit is provided which measures the resistance between each electrode intersection and provides an output representative of the opposing forces at the intersection. The circuit limits the maximum possible current which can flow in the sensor and provides increased resolution in measuring pressure between contacting surfaces.

A review of the methods for the measurement of coating-substrate adhesion☆

Abstract: Modern coating techniques now offer the possibility of modifying the surface of an engineering component to achieve improvements in both performance and reliability. One important and often overriding factor is the degree of adhesion between the coating and its substrate, and the aim of this paper is to discuss the methods which can be used to assess this critical property of the coating-substrate system. The advantages and disadvantages of each technique, e.g. the pressure-sensitive tape test, indentation testing, the scratch test, laser methods etc., are reviewed.

Method for embossing a coated sheet with a diffraction or holographic pattern

Abstract: A method for decoration of paper of plastic sheeting and other substrates, involving a novel technique for coating and embossing the substrate. The paper or plastic sheeting is supplied with a coating of thermosensitive material, as by extrusion. The coated sheet is heated to adequately soften the coating, such as by use of a heated cylinder, and remote heat sources such as infrared heaters. The softened sheet surface is then decorated using an embossing member, to provide a diffraction pattern or hologram. Use of an embossment pattern of lesser depth than the surface roughness of the sheet before embossing provides attractive decorative patterns.

Coated article and method of manufacturing the article

Abstract: Disclosed is a coated article having a substrate with an adherent, abrasion resistant carbon coating. In a preferred examplification the coating is substantially transparent to visible light and partially absorbing to ultraviolet light. The coating has a relatively disordered portion at the substrate-coating interface and a relatively ordered portion remote from the substrate-coating interface. The coating is a microwave deposited coating with deposition initially at a low microwave energy, and thereafter at a high microwave energy.

Thermal transfer printing

Abstract: A retransfer intermediate sheet for receiving an image to be printed onto an article by thermal retransfer comprises a substrate; and an image-receiving coating on one side of the substrate for receiving an image by printing of dye-containing ink, the coating comprising a fluid-absorbing layer and a superposed dye management layer comprising functionalised polyvinyl alcohol and/or an ionic polymer. The dye management layer functions to reduce back diffusion and to increase dye transfer efficiency, resulting in production of printed images of improved optical density. The sheet can be heat-deformable, and finds particular use in printing on 3D articles, e.g. being heated and vacuum formed to conform to an article. The invention also covers a method of printing and an article bearing a printed image.

Metastable coatings — Prediction of composition and structure

Abstract: New metastable materials can easily be obtained using low temperature vapour deposition techniques. These non-equilibrium materials have constant compositions and structures up to temperatures of about 0.3Tm (Tm, melting point; for hard substances approximately 2500 – 3000 °C) and therefore offer a variety of new coating materials with unknown properties. The compositions and structures of these vapour-quenched coatings can be roughly estimated from the equilibrium phase diagrams and more accurately from the free energies of the solution phases of the coating components considering diffusion coefficients, deposition rate and structural parameters. This paper gives an overview on the ideas and possibilities for predicting the compositions and structures of multicomponent coatings, especially for combinations between metallic and covalent hard materials. Coating experiments using (Ti, Al)N, (Zr, Al)N, (Hf, Al)N and other combinations are compared with the calculations of the compositions and structures in the corresponding stable or metastable systems. Agreement between experiment and prediction is found. The calculations are based on the estimated lattice stabilities of the different compounds in the various structures and the regular solution model with estimated interaction parameters.

Polyalkylcyanoacrylates as colloidal drug carriers.

Abstract: A considerable amount of energy has been spent in creating new colloidal drug delivery systems that are acceptable for general systemic use. Among these new systems, nanoparticles made with biodegradable polymers are gaining more and more interest. The aim of this paper is to describe the preparation and characterization of these nanoparticles and their in vivo behavior and to show the possibilities of using them in various fields of human medicine. The interaction of polyalkylcyanoacrylate nanoparticles with cells in culture is also discussed, as well as the possibility of improving the specificity of the carrier by coating it with monoclonal antibodies.

Chewable medicament tablet containing means for taste masking

Abstract: Chewable medicament tablets are made from coated granules of medicament wherein the coating on said granules comprises a blend of cellulose acetate or cellulose acetate butyrate and polyvinyl pyrrolidone.

Sustained-release formulations

Abstract: A granular sustained-release formulation of a pharmacologically active substance presented in the form of a tablet, said tablet comprising sufficient granules to provide a predetermined dose or number of doses of the pharmacologically active substance and effervescent or water-dispersible ingredients, each of said granules having a diameter of preferably between 0.5 and 2.5 mm and comprising: a) a core comprising one or more pharmacologically active substances and preferably one or more excipients; and b) a coating covering substantially the whole surface of the core and comprising 100 parts of a water insoluble but water swellable acrylic polymer and from 20 to 70 parts of a water soluble hydroxylated cellulose derivative, the weight of the coating being from 2 to 25% of the weight of the core. A method for preparing this effervescent of water-dispersible tablet formulation is also provided. Such formulations enable large dosages in sustained-release form to be more easily administered to patients.

Retroreflective sheet material and method of making same

Abstract: A retroreflective sheeting has microretroreflective formations on one surface which are partially metallized and partially exposed to the atmosphere about them. It is produced by forming a coating on microprism surface, and this coating includes a thin metallic deposit over substantially the entire surface and a second coating material over only a portion of the surface. The coated surface is then exposed to a solvent to remove the coating from its predominant area and leave the metal deposit on only a minor portion of the area. A backing sheet is then applied over the microprisms and bonded to the retroreflective sheeting so as to leave an air interface about the predominant area of the microprisms. As a result, some light rays are retroreflected by the metal deposit and some are retroreflected by the atmosphere interface. The sheeting exhibits daytime whiteness over the bulk of its surface area.

Sol-gel antireflective coating on plastics

Abstract: An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof The film is particularly useful for coating plastics

Antimicrobial medical glove

Abstract: An antimicrobial medical glove consisting essentially of an outer elastomeric body in the shape of a hand and an inner coating containing an antimicrobial agent, said inner coating being capable of slowly releasing said antimicrobial agent in an amount and over a period of time sufficient to maintain an essentially bacteria-free and fungus-free environment within said glove after said glove has been donned.

Millimeter-wave propagation at street level in an urban environment

Abstract: Measurements on point-to-point transmission at street level were performed in downtown Denver, CO, with RF probes that operated at 9.6, 28.8, and 57.6 GHz. All probes were mounted on self-contained vehicles, permitting a variety of path scenarios. Information on performance of these channels for propagation in an urban environment on both line-of-sight and non-line-of-sight paths is presented. For non-line-of-sight (non-LOS) paths obstructed by buildings of several common materials, results that showed signal attenuations in excess of 100 dB. When the LOS followed a path directly through clear glass walls, the attenuation was small at all probe frequencies. However, when the glass wall had a metalized coating to reduce ultraviolet and infrared radiation, the attenuation increased by 25 to 50 dB for each metallized layer. In most cases no signals could be detected through steel reinforced concrete or brick buildings. >

Process for applying reinforcing material to a diaper cover material

Abstract: A technique for adhering individual patches of substrate material to spaced-apart regions of a moving web layer comprises a transporting mechanism for moving the web layer and a supplying mechanism for providing a selected substrate material. An applicating mechanism deposits a selected coating of hotmelt adhesive onto the substrate material, and a regulating mechanism automatically maintains a selected cross-directional registry between the substrate material and the deposited coating of adhesive. The coated substrate is cooled, and a directing mechanism engages the coated substrate to feed it to a separating mechanism at a selected rate. The separating mechanism segments the coated substrate into individual patches. A phasing mechanism provides a selected spatial segregation between the individual patches, and an assemblying mechanism adhesively secures the segregated patches onto selected spaced regions of the moving web layer. An indexing mechanism selectively displaces the coated substrate material from the separating mechanism when the directing mechanism is disengaged from the substrate material.

Water-dispersible polymeric compositions

Abstract: Disclosed is a process for preparing polymeric compositions which are suitable for coating medicaments or for use in cosmetic formulations and the novel compositions prepared therefrom. The process makes stable, colloidal, latex-like dispersions of coating polymers which can be readily dried to form polymeric powder materials. The process makes use of a novel combination of a water-in-oil emulsifier and an oil-in-water emulsifier.

Chemical durability of high‐temperature superconductor YBa2Cu3O7−x in aqueous environments

Abstract: The stability of YBa2Cu3O7−x in water and 100% humidity has been investigated at three temperatures using pH measurements, x‐ray diffraction, and scanning electron microscopy. The oxide‐ceramic superconductor is highly unstable and reacts rapidly with water and also degrades in moisture. Dissolution of the oxide perovskite in water is highly incongruent. The corrosion products are found to be BaCO3, CuO, O2, etc. Barium hydroxide is first formed which further reacts with atmospheric CO2 to form needle‐shaped crystals of BaCO3. For any practical applications, devices made from these materials would have to be protected with an impermeable coating to prevent deterioration from atmosphere.

Optical information recording medium

Abstract: PURPOSE:To improve mass productivity and to reduce production cost by using a polyolefin copolymer to form the substrate of an optical recording medium formed by providing a recording film on the substrate having tracking grooves on the surface and forming the recording film by coating an org. compd. film. CONSTITUTION:The substrate of the optical recording medium formed by providing the recording film on the substrate having the tracking grooves on the surface is formed by using a polyolefin (PO) resin, blended polymer essentially consisting of the PO resin, or copolymer essentially consisting of olefin. The recording film is formed by coating on the substrate. The substrate consisting of such PO resin can be prepd. by, for example, injection molding and is highly resistant to solvents. Even if, therefore, the recording film is formed by wet process coating, the dissipation of the tracking grooves of the substrate, the decreased reflectivity by the infiltration, etc., of the solvent, and the impaired focusing, tracking and signal reading out of a recording and reproducing device are obviated and the range of solvent selection is widened. The mass productivity is thereby enhanced, the cost is greatly reduced and the good performance is stably obtd.

Method of hydrophilic coating of plastics

Abstract: Plastics, particularly a method of hydrophilic coating of plastics, for example, a contact lens, with a lubricating and visually acute mucopolysaccharide film which is immobilized upon the surface of the plastic for the lifetime of the plastic. A preferred method includes first coating the plastic with an aqueous solution of a mucopolysaccharide, drying by applying a water-miscible solvent, then crosslinking and permanently immobilizing the first coating upon the plastic by applying a solution of catalyzed organic solution aliphatic polyisocyanates.