Abstract: Two or more superconductors are reacted together to form a non-superconducting phase encapsulating a residual superconducting phase. For example YBa.sub.2 Cu.sub.3 oxide is reacted with Bi.sub.2 Sr.sub.2 CaCu.sub.2 oxide to form a superconducting product containing a novel non-superconducting oxide of Y, Bi, and Ba. A superconducting YBa.sub.2 Cu.sub.3 oxide remains as an interconnected phase throughout the product. The new non-superconducting phase largely encapsulates and insulates the superconducting phase.
Abstract: Improved process for making Tl-Ca-Ba-CuO superconductors. A solution of the monocarboxylates (e.g., acetates) of Ca, Ba, and Cu is dried, calcined, mixed with Tl.sub.2 O.sub.3, and the mixture is heated to make a superconductor. The method minimizes introduction of contaminants. Novel compositions result.
Abstract: Novel reactive hot melt structural adhesives comprising urethane oligomer and epoxy mixture in specified ratios. The compositions offer very high shear, peel, and impact strengths, properties of particular value in bonding adherends in an auto body assembly line.
Abstract: Poly(vinyl chloride) plastisol compositions modified with epoxy and acid anhydrides can be painted wet-on-wet with acid catalyzed, high solids enamel paints, followed by curing at 120.degree. C. or lower, to give strongly adherent products on electrodeposition coatings and dry, tack-free painted surface. The compositions are also stabilized by the addition of an imide, which provides storage stability at 40.degree. C. for more than three days.
Abstract: A waterproofing system including a water-based latex primer composition and a waterproofing adhesive membrane. The primer exhibits excellent adhesion to concrete and an excellent surface for adhesion by the waterproofing membrane. The primer is a latex emulsion including butyl acrylate, styrene and acrylonitrile.
Abstract: Process and apparatus for separation of hydrogen, methane, and higher hydrocarbons from gas feed stock. For example, such feedstock is fed to a gas-liquid separator, the resulting gas is treated in a gas-gas membrane separator, the residue is separated in a second gas-liquid separator, and the permeate is separated in a second gas-gas membrane separator; the process may be repeated until the desired effluent specificity is achieved.
Abstract: Disclosed are semipermeable fluid separation membranes prepared from polyaromatic polymers including aromatic repeat units of which at least five mole percent are substituted by moieties having ethylenically unsaturated carbon bonds wherein the polymer is crosslinked through carbon bonds between the ethylenically unsaturated moieties. The invented membranes have enhanced durability yet retain very high fluid, especially gas, permeability.
Type:
Grant
Filed:
November 3, 1988
Date of Patent:
November 21, 1989
Assignee:
W. R. Grace & Co.-Conn.
Inventors:
Charles R. Morgan, Cheng-Chi Chen, Thomas A. Blinka, Alan S. Obligin
Abstract: An improved method is disclosed for coupling membrane elements of a fluid separation module in series. The improvement comprises providing flexible coupling members having two open ends and a passage between said ends; and securing the first end of a coupling member to the residual end of each membrane element (with the optional exception of the last in the series) and securing the second end of the coupling member to the feed end of the next membrane element in the series if any. Fluid from the residual end of each membrane element except the last may thus be directed to the feed end of the next membrane element. An improved fluid separation module employing such couplings is disclosed; as is an improved membrane element having a coupling member secured thereto.
Abstract: A liquid, solvent-free or low solvent hardenable polyurethane-modified bitumen composition is described, which is based on a bitumen modified with a polyurethane prepolymer. The compatability between bitumen and polyurethane prepolymer is achieved by a plasticizer system comprising a primary and a secondary plasticizer. The inventive composition is particularly suitable as an adhesive, sealant, foam material or coating compound.
Abstract: In a process for bonding two substantially flat elements, a highly viscous sealant containing balls as spacers is applied to a first element in a thickness at least corresponding to the desired distance from the second element and the latter is engaged and pressed onto the first element. The balls (6) are successively added to the sealant in an applicator nozzle (2) prior to the application of the sealant. This process can be performed with an apparatus having an applicator nozzle (2) for the supply and application of the sealant (4) and a ball supply device (10). The latter contains a supply duct (12) for supplying the balls (6), an outlet tube (14) connected at an angle to supply duct (12) and issues via an opening (16) laterally into the applicator nozzle (2) and an impact plunger (18), which is movable by the end remote from applicator nozzle (2) into the outlet tube (14).
Type:
Grant
Filed:
June 7, 1988
Date of Patent:
September 12, 1989
Assignee:
Teroson GmbH
Inventors:
Jean-Willem Delbeck, Anton M. Schleicher
Abstract: An aqueous solution of the monocarboxylates of Y, Ba, and Cu is spray dried, providing a contaminant-free non-hygroscopic product which is homogeneous at the atomic level. In a preferred embodiment Y, Ba, and Cu acetates are used in a molecular ratio of 1:2:3, giving a product which can be calcined to give a superconducting mixed oxide, YBa.sub.2 Cu.sub.3 O.sub.x, where x is 6.8-7.0.
Abstract: Superior homogeneity in ceramic materials is achieved by forming an aqueous solution of trichloroacetates of certain metals, heating the solution to decompose the trichloroacetates to form carbonate precipitates, and recovering the carbonate precipitates. The latter can be calcined to form superconductors. For example, oxides, or carbonates of Y, Ba, and Cu are dissolved in aqueous trichloroacetic acid and the solution is heated to decompose trichloroacetate ions and to form mixed carbonates, which precipitate. The precipitate is recovered and calcined to form a superconducting material.
Abstract: An improved method for using a membrane to separate gases provides for relieving the pressure on the permeate side of the membrane when the permeate pressure exceeds the feed pressure by a selected amount. Gas separation apparatus in general and, in particular, spiral wound membrane units are improved by providing for relief of such reversed pressure differentials. A suitable device for relieving the reversed pressure differential includes a body, a poppet movably mounted to the body and biased to a closed position until the selected pressure differential is reached, and a seal for preventing gas flow through the device when the poppet is closed.
Abstract: A liquid, solvent-free or low-solvent hardenable polyurethane-modified bitumen composition is described, which is based on a bitumen modified with a polyurethane prepolymer. The compatibility between bitumen and polyurethane prepolymer is achieved by a plasticizer system comprising a primary and a secondary plasticizer. The inventive composition is particularly suitable as an adhesive, sealant, foam material or coating compound.
Abstract: Novel polyurethane formulations especially useful as membranes for the protection of bridge deckings. The polyurethane is prepared by mixing two components, A and B. Component A consists essentially of a low-molecular weight polyol, e.g., glycerol; a poly(oxypropylene) triol; and an elastomer. Component B is a special MDI, either a mix of 4,4'- and 2,4'-isomers of diphenylmethane diisocyanate or a mix of 4,4'-diphenylmethane diisocyanate and its reaction product with a low molecular weight poly(oxypropylene).
Type:
Grant
Filed:
January 7, 1988
Date of Patent:
November 29, 1988
Assignee:
W. R. Grace & Co.-Conn.
Inventors:
Cung Vu, Susan P. Buxbaum, Norman E. Blank, Richard C. Hartwig
Abstract: A polyurethane sealant, particularly suitable for forming the seal around a double glazing unit, is formed by reacting an isocyanate component with a reactive component that is an isoprene polymer having terminal functional groups.
Abstract: The present invention relates to the manufacture of printed circuit boards and, particularly, to a process of miniaturizing said printed circuit board.
Abstract: A one component, solventless, storage stable, low temperature, curable urethane composition comprising(1) a branched, blocked isocyanate prepolymer comprising the reaction product of a polyol having a functionality of at least 2, an aromatic polyisocyanate having a functionality of at least 2, the combined functionality of the polyol and the polyisocyanate being greater than 4 and a ketoxime blocker;(2) a polyol crosslinking agent containing at least two OH groups;(3) a deblocking and curing catalyst for (1); and(4) a dessicant.The composition on heating to 100.degree.-120.degree. C. results in a cured polyurethane within 10-30 minutes. The composition can also be combined with polymeric powder, e.g., polymethylmethacrylate to yield cured reactive plastisols. The aforesaid compositions are useful as sealants, coatings or adhesives.
Abstract: This invention relates to a moisture curable, isocyanate terminated, branched prepolymer which is the reaction product of (a) an alcohol having two or three --OH groups, (b) a hydrophobic polymeric diol or triol and (c) at least one polyisocyanate, said prepolymer having an NCO content in the range 0.3 to 1.0 meq/q. Exposure of the prepolymer as a coating on a substrate to moisture under atmospheric conditions results in a cured coating having excellent adhesion to the substrate and excellent abrasion resistance.
Abstract: A heat activatable adhesive or sealant organic resin composition comprising(1) a liquid, ethylenically unsaturated monomer, oligomer or prepolymer of the formula: ##STR1## wherein R is H or CH.sub.3, R.sub.1 is an organic moiety and n is at least 2,(2) a thermal initiator selected from the group consisting of substituted or unsubstituted pinacols, azo compounds, thiurams, organic peroxides and mixtures thereof, and(3) a thermoplastic adhesive material selected from the group consisting of polyesters, polyvinyl acetals, polyamides, butadiene-acrylonitrile copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-ethylene-butylene copolymers, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ethylene propylene diene monomer and mixtures thereof.The composition after application to the parts to be bonded or sealed forms a thermoset bond or seal on application of heat thereto, preferably by electromagnetic techniques including dielectric and induction heating.