Abstract: A method for heat treating a coated substrate is described wherein the outer coating on the substrate is comprised of a chemically vapor deposited mixture of tungsten and tungsten carbide. The coated substrate is heated to the deposition temperature or not substantially above the deposition temperature in a non-reactive atmosphere. The heat treating temperature is sufficient to confer a desired improvement in erosive and abrasive wear resistance in the outer coating but does not result in substantial degradation of the mechanical properties of the substrate or in formation of undesirable inter-metallic layers.

Abstract: The invention is a process for recovering oxygen from an oxygen-containing gaseous mixture containing one or more components selected from water, carbon dioxide or a volatile hydrocarbon which process utilizes ion transport membranes comprising a multicomponent metallic oxide containing strontium, calcium or magnesium. The process utilizes a temperature regime which overcomes problems associated with degradation of strontium-, calcium- and magnesium-containing multicomponent oxides caused by carbon dioxide.

Abstract: A structural article for high temperature applications comprises a body formed of at least partially consolidated, particulate silicon nitride, a conformal outer coating of silicon nitride or silicon carbide on the body, and a conformal intermediate layer of a silicon, oxygen and nitrogen-containing compound, i.e. silicon oxynitride, chemically bonded to both the body and the outer coating. The method for making such an article comprises providing a body formed of at least partially consolidated, particulate silicon nitride, oxidizing the surface of the body, removing silicon dioxide from the oxidized surface of the body; and chemically vapor depositing a conformal outer coating of silicon nitride or silicon carbide. The conformal outer coating provides a protective envelope around and assists in high temperature isostatic pressing of the body and hence permits one to use the structural article in isostatic pressing processes.

Abstract: Valuable process gas is dried to a low water content, for example a dew point of less than -20.degree. F., using membrane separation in which compression of the permeate gases and condensation and separation of liquid water from the permeate stream is combined with a total recycle of uncondensable permeate gases so that no process gas is lost as a result of the drying operation. Feed gas is combined with the recycled gas either prior to compressing, cooling and separating the liquid water from the process gas or subsequent to these steps, depending upon the pressure of the available feed stream to be dried. Membrane separation efficiency is improved by sweeping the downstream surfaces of the membrane with dried product gas. All of the sweep gas is recaptured with the permeate gases and returned to the separation unit, thereby enabling 100%, recovery of the fresh feed gas from the drying operation. Only liquid water and dissolved gases are purged from the system.

Abstract: The invention describes a process for catalytically destroying NOx and carbon monoxide present in oxygen-containing combustion products wherein methane serves as a reductant. The process comprises combusting a fuel source in the presence of oxygen to form combustion products comprising nitrogen oxides, carbon monoxide and oxygen; introducing methane into the combustion products in an amount such that the total amount of methane to nitrogen oxides present, expressed as a ratio, by volume is greater than about 0.1; and reacting the nitrogen oxides, carbon monoxide, methane and oxygen in the presence of an exchanged crystalline zeolite under conditions sufficient to convert the nitrogen oxides and carbon monoxide to gaseous nitrogen, water and carbon oxides. Suitable catalysts include zeolites having a silicon to aluminum ratio of greater than or equal to about 2.

Abstract: A process for selectively preparing predominantly noncyclic polyalkylene polyamines wherein one or more linear alkyleneamines are reacted in the presence of a mordenite catalyst under conditions sufficient to effect a disproportionation reaction. Preferably, the catalyst is prepared by treating the mordenite with an amount of a phosphorus-containing moiety sufficient to provide a catalyst which is impregnated with from about 0.01 to 15 wt % elemental phosphorus based upon the total weight of the impregnated mordenite catalyst. The process is especially useful in the production of diethylenetriamine wherein ethylenediamine is reacted in the presence of LZ-M-8 catalyst which has been treated with an amount of ammonium dihydrogen phosphate sufficient to provide a catalyst which is impregnated with from about 0.1 to 8 wt % elemental phosphorus based upon the total weight of the impregnated mordenite catalyst. The products can be isolated by conventional techniques such as distillation.

Abstract: This invention relates to a process for restoring permeance of an oxygen-permeable ion transport membrane utilized to recover oxygen from an oxygen-containing gaseous mixture which contains water, carbon dioxide or volatile hydrocarbons. The process utilizes a class of ion transport membranes formed from multicomponent metallic oxides wherein permeance of such membranes had been believed to be permanently degraded by water and the like under conventional process operating temperatures. This invention provides a continuous process for restoring oxygen permeance of such membranes caused by deleterious interaction between the membrane and components such as carbon dioxide, water or hydrocarbons at elevated process temperatures.

Abstract: The present invention relates to novel multi-layer composite solid state membranes which are capable of separating oxygen from oxygen-containing gaseous mixtures at elevated temperatures. The membranes comprise a multicomponent metallic oxide porous layer having an average pore radius of less than about 10 micrometers and a multicomponent metallic oxide dense layer having no connected through porosity wherein the porous and dense layers are contiguous and such layers conduct electrons and oxygen ions at operating temperatures.

Abstract: The present invention relates to a process for preparing acetals and hemiacetal esters which comprises reacting a vinyl ester and an alcohol in the presence of a solvent having a dielectric constant of between about 15 and about 50 and an effective amount of palladium- or platinum-containing catalyst, in the absence of an active support, under reaction conditions sufficient to form the acetal or hemiacetal ester and recovering the acetal or hemiacetal ester.

Abstract: N-vinyl-O-methyl carbamate is formed preferentially by heating dimethyl ethylidene dicarbamate in the liquid phase at a temperature of 155.degree. to 350.degree. C. and at a pressure which permits the vinyl carbamate to vaporize as it is formed. This vinyl carbamate is quickly condensed and can then be separated from the methyl carbamate which also emanates from the liquid phase. The yield of N-vinyl-O-methyl carbamate is enhanced by including carbon in the liquid phase in contact with the dimethyl ethylidene dicarbamate as it is pyrolyzed. Using carbon in the same manner is advantageous in producing other lower alkyl N-vinyl-O-alkyl carbamates. Preferably the carbon has a surface area of 300 to 1500 m.sup.2 /g and is present in an amount such that the weight ratio of dialkyl ethylidene dicarbamate to carbon is in the range of 50 to 500. The product is a monomer which can be used in making amine-functional polymers.

Abstract: The invention describes a process for selectively preparing ortho-fluorinated substituted aromatic compounds wherein an aromatic compound containing a substituent capable of directing ortho metalation is contacted with a metalating reagent under reaction conditions sufficient to form an ortho-metalated substituted aromatic compound. The ortho-metalated substituted aromatic compound is reacted with an electrophilic fluorinating reagent under reaction conditions sufficient to form the desired ortho-fluorinated substituted aromatic compound which is then recovered from the reaction mixture. The process which utilizes a metalation intermediate prior to effecting the electrophilic fluorination step overcomes problems associated with prior art electrophilic fluorination processes which do not proceed through a regiospecifically controlled intermediate.

Abstract: The present invention relates to a process for producing ethylidene diacetate (EDDA) wherein at least one process step comprises condensing a feedstock of acetaldehyde and acetic anhydride in the presence of acetic acid and an iodide catalyst selected from the group consisting of potassium iodide, lithium iodide, methyl iodide and mixtures thereof. In a preferred embodiment, EDDA is prepared in an integrated process wherein the previously mentioned feedback is prepared by reacting dimethyl ether and acetic acid to form a first intermediate product mixture and hydrocarbonylating the first intermediate product mixture to form the condensation feedstock.

Abstract: This invention is a residue-free vapor-phase process for etching metallic layers during the manufacturing of integrated circuits. The process comprises contacting a portion of the metallic surface to be etched with an effective amount of an etching agent comprising a .beta.-diketone or .beta.-ketoimine dispersed in an atmosphere capable of oxidizing the metal to be removed at a temperature sufficient to form a volatile metal-ligand complex. The volatile metal-ligand complex is sublimed from the surface thereby etching successive layers of the metal.

Abstract: This invention is a vapor-phase process for cleaning metal-containing contaminants from the surfaces of integrated circuits and semiconductors between the numerous fabricating steps required to manufacture the finished electronic devices. The process employs cleaning agents comprising an effective amount of a partially halogenated or fully halogenated linear or branched carboxylic acid having from 2 to about 10 carbon atoms wherein the halogen is selected from fluorine or chlorine. The process comprises contacting the surface to be cleaned with an effective amount of the desired cleaning agent at a temperature sufficient to form volatile metal-ligand complexes on the surface of the substrate to be cleaned. The volatile metal-ligand complexes are sublimed from the surfaces of the substrate providing a clean, substantially residue-free surface.

Abstract: The present invention is a process for producing organic esters wherein a dialkyl ether and a carboxylic acid are reacted in the presence of a catalyst consisting essentially of an iodide of a Group IA element under reaction conditions sufficient to form a reaction mixture comprising the desired organic ester and an alcohol and recovering the ester from the reaction product mixture. For example, methyl acetate can be prepared by reacting dimethyl ether and acetic acid in the presence of a hydrogen iodide or lithium iodide catalyst under conditions sufficient to form methyl acetate and methanol. While typical processes produce an azeotropic mixture of the desired organic ester and water, the claimed process utilizes a combination or reactants and catalysts wherein water is not produced in appreciable amounts. Therefore, the organic ester product can be separated conveniently thereby avoiding a cumbersome azeotropic distillation step as required in prior art processes.

Abstract: This invention is a vapor-phase process for cleaning metal-containing contaminants from the surfaces of integrated circuits and semiconductors between the numerous fabricating steps required to manufacture the finished electronic devices. The process comprises contacting the surface to be cleaned with an effective amount of a cleaning agent comprising a carboxylic acid selected from acetic acid or formic acid at a temperature sufficient to form volatile metal-ligand complexes on the surface of the substrate to be cleaned. The volatile metal-ligand complexes are sublimed from the surface of the substrate providing a clean, substantially residue-free surface.

Abstract: Vinyl acetate/ethylene (VAE) copolymer emulsions having extended shelf life which are particularly suited for use as binders of nonwoven substrates. The copolymer emulsions are prepared by incorporating 1 to 45 wt % tetramethylol glycoluril, based on the amount of vinyl acetate in the copolymer, into an aqueous dispersion of a copolymer consisting essentially of 60 to 94 wt % vinyl acetate, 5 to 30 wt % ethylene and 1 to 10 wt % of a crosslinkable comonomer. Suitable crosslinking monomers include N-acrylamidoglycolic acid and N-methylol acrylamide. Nonwoven products formed by depositing the emulsion onto a nonwoven substrate exhibit significantly improved resistance to organic solvents.

Abstract: The invention describes a highly efficient catalytic pollution control process for removing N.sub.2 O from gaseous mixtures. The catalytic process, which is substantially unaffected by the presence of oxygen, comprises contacting an N.sub.2 O-containing gaseous mixture with a catalyst comprising a crystalline zeolite which, at least in part, is composed of five membered rings having a structure type selected from the group consisting of BETA, MOR, MFI, MEL and FER wherein the crystalline zeolite has been at least partially ion-exchanged with a metal selected from the group consisting of copper, cobalt, rhodium, iridium, ruthenium and palladium under conditions sufficient to convert the N.sub.2 O into gaseous nitrogen and gaseous oxygen.

Abstract: Blends of polymers of vinyl acetate and polymers derived from acrylic acid have been discovered which exhibit thermodynamic miscibility. These polymer blends exhibit excellent mechanical compatibility, provide enhanced toughness and strength superior to the sum of the weight averaged properties of the constituent polymers and are useful in molding structures such as films and in compounded formulations such as coatings, emulsions and adhesives.

Abstract: The invention describes a catalytic process for destroying NOx from oxygen-containing combustion products wherein methane serves as a reductant. The process comprises contacting the NOx-containing combustion products with a desired amount of methane and oxygen in the presence of a metal-exchanged crystalline zeolite having a silicon to aluminum ratio of greater than or equal to about 2.5 under conditions sufficient to effect conversion to gaseous nitrogen, water and carbon oxides. The zeolites are exchanged with a cation selection from the group consisting of cobalt, nickel, iron, chromium, rhodium and manganese.