Abstract: The present invention relates to a composition for depositing a temporary, selectively soluble protective coating onto a substrate and a process for using the same. The composition consists essentially of a copolymer consisting of 35 to 85 weight percent vinyl acetate and from 15 to 65 weight percent of a predefined monoalkyl maleate which is dispersed in a solvent/vehicle. The protective coatings deposited therefrom are substantially impervious to aqueous media having acidic or neutral pH and provide an effective barrier against damage to the substrate's surface. At the desired time, the protective coating can be removed from the substrate by dissolution in an aqueous alkaline solution.

Abstract: This invention is a residue-free cleaning process for removing metal-containing contaminants from a surface of a substrate of the type used in manufacturing semi-conductor devices. The process comprises contacting the substrate with an effective amount of a cleaning agent comprising a .beta.-diketone or .beta.-ketoimine dispersed in an atmosphere capable of oxidizing the metal-contaminants at a temperature sufficient to form volatile metal-ligand complexes on the surface of the substrate. The volatile metal-ligand complexes are sublimed from the surface of the substrate leaving essentially no residue.

Abstract: A method for making a lightweight structure having a high stiffness to weight ratio comprising providing a substrate defining at least a pair of outer surfaces spaced from each other, boring at least one hole through the structure to provide at least one void passage extending through the substrate between the outer surfaces, coating the outer surfaces of the substrate and the surfaces of the passage with a chemical vapor deposited material to a thickness of about one millimeter, plugging the void passage with a plug of a substrate material, and further coating the coated outer surfaces of the substrate and the ends of the plugs with a chemical vapor deposited material to form a continuous monolithic structure thereon.

Abstract: A method is described for improving the erosion and abrasion wear resistance and hardness of the internal wear surfaces of structures such as nozzles, jets, ducts, chutes, powder handling tubes, valve housings, conveyors, drill bushings and the like. A substantially pure tungsten layer is chemical vapor deposited on the internal wear surface of the body of the structure followed by a chemical vapor deposited top coating comprising a mixture of tungsten and tungsten carbide. The tungsten carbide is selected from the group consisting of W.sub.2 C, W.sub.3 C, and mixtures thereof and is fine grained, non-columnar and has a substantially layered microstructure. Also described are structures formed by the method.

Abstract: A residue-free fluxing process wherein the active fluxing agent comprises a .beta.-diketone or .beta.-ketoimine ligand. Such ligands react with surface metal oxides on workpieces to be soldered to form volatile metal-ligand complexes as reaction products which are sublimed from the surface leaving essentially no residue on the workpieces. The fluxing agents can be utilized in gas-phase processes wherein the workpieces are contacted with an effective amount of one or more ligands which are dispersed in a carrier gas or solvent or by incorporating the ligands into an alloy-vehicle mixture for use as conventional creams or pastes. The invention eliminates the need for post-reflow cleaning using solvents since no flux residue remains on the workpieces to be soldered following volitilization of the metal-ligand complex.

Abstract: The present invention is a class of semi-permeable polymeric membranes and processes for using such membranes to separate one or more components of a gas mixture. The membranes which are formed from a polymer blend of a first polyimide containing an aromatic diamine and a second polyimide containing an alkenylated diamine having an allyl or allylaryl group exhibit high gas perm-selectivities. The polyimide blends can be surface modified by treatment with an activating force such as high energy electromagnetic irradiation or with a free radical source to impart enhanced selectivity to the membrane without causing a large decrease in composite permeance. These membranes formed from polyimide blends are especially useful in effecting the separation of oxygen and nitrogen from air.

Abstract: The present invention relates to compositions of matter corresponding to the formula: ##STR1## wherein R.sub.1 through R.sub.4, inclusive, are independently selected from a hydrogen atom, a linear or branched alkyl or alkoxy group having from 1 to about 8 carbon atoms, an alkenyl group having from 2 to about 8 carbon atoms, amino, cyano or R.sub.1 and R.sub.1, R.sub.1 and R.sub.2, R.sub.2 and R.sub.3 or R.sub.3 and R.sub.4 may together form part of a cyclohydrocarbyl ring. The subject 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydrides demonstrate utility as reactants in the preparation of polyimides used in the fabrication of membranes for separating gaseous mixtures into their respective components.

Abstract: Diamine compounds having the structural formula: ##STR1## wherein R.sub.1 is a methyl or ethyl group, can be used in preparing various polymers which are useful components in gas separation membranes. The combined effect of specific substituents ortho to the amino groups and the fluorenylidene bridging group imparts useful properties to polymeric membranes formed with these monomers.

Abstract: An improved capacitively coupled radio frequency-plasma enhanced chemical vapor deposition (PECVD) apparatus and process are disclosed for depositing a uniform coating of material on substrates. The apparatus includes a secondary electrode defining a reaction zone within an outer chamber and an RF electrode in concert with the secondary electrode for generating a plasma within the reaction zone. The electrode comprising a base and a finger extending through the reaction zone for distributing a plasma field uniformly throughout the reaction zone. The process comprises heating a substrate to a deposition temperature in the range of about 300.degree. to 650.degree. C. Reactant gases are introduced into the PECVD reactor and a coating of about 0.2 to about 20 .mu.m is deposited onto the heated substrate. This low temperature process is particularly adapted to coating three-dimensional objects of metals, metal alloys and mixtures of metals.

Abstract: The present invention is a class of semi-permeable polyimide membranes and a process for using such membranes to separate one or more components of a gaseous mixture. The membranes are prepared from a polyimide having surface-modifiable functionalities comprising repeating units formed from an aromatic dianhydride and a bridged alkylated bisaniline wherein the bridging group of the diamine possesses restricted, rotatable rigid or low Van Der Waal energy substituents which are orthogonal to the polymer backbone. The membranes formed therefrom are contacted in the presence of an oxygen source with an activating force such as high energy electromagnetic irradiation to effect modification of the polymer surface. The surface-modified polyimide membranes exhibit high gas perm-selectivities and are especially useful in effecting the separation of oxygen and nitrogen from air.

Abstract: The present invention is a class of semi-permeable polyimide membranes and a process for using such membranes to separate one or more components of a gaseous mixture. The membranes are prepared from a polyimide having surface-modifiable functionalities comprising repeating units formed from an aromatic dianhydride and an alkyl-substituted phenylenediamine having at least one hydrogen atom located on a ring position ortho to an amine nitrogen. The membranes formed therefrom are contacted in the presence of an oxygen source with an activating force such as high energy electromagnetic irradiation to effect modification of the polymer surface. The surface-modified polyimide membranes exhibit high gas perm-selectivities and are especially useful in effecting the separation of oxygen and nitrogen from air.

Abstract: A process for producing microcellular foamed articles wherein a low pressure compressible, inert gas such as nitrogen is used as a foaming agent.

Abstract: The present invention relates to a process for the production of polyurethanes wherein a tertiary amine functionality is incorporated into the side chain of an aromatic diamine, preferably a diaminobenzamide, to form a catalytic polyurethane chain extender. These chain extenders are polyurethane catalysts that provide adequate cure without residual odor and safety hazards associated with the more traditional tertiary amine catalysts. When reacted with the isocyanate reactive group the non-tertiary amine portion of the chain extender is bound to the polymeric network. Diffusion of the catalyst species from the polyurethane has been prevented, thus negating odor and toxicity as problems. These aromatic diamines provide enhanced polyurethane physical properties.

Abstract: A process for preparing motor fuel grade alcohol wherein an ethanol fermentation reactor effluent is distilled to produce an overhead product comprising 10 to about 40 mole percent ethanol and a bottom product comprising the non-alcoholic components. The motor fuel grade alcohol is recovered in high yield from the ethanol/water overhead product mixture in a liquid phase cyclic selective adsorption process which comprises a plurality of adsorption columns operated in cycle in a predetermined time sequence, each adsorption column containing an adsorbent, wherein each respective adsorption column undergoes successive steps of adsorption, desorption and rinsing.

Abstract: A process for preparing an alkyl-tert-alkyl ether wherein an olefin having a double bond on a tertiary carbon atom and a primary alcohol are reacted in the presence of a catalyst under conditions sufficient to produce an azeotropic alcohol/ether/hydrocarbon mixture containing the alkyl-tert-alkyl ether. The azeotropic alcohol/ether/hydrocarbon mixture is subjected to a cyclic liquid phase adsorption process sequence to selectively remove the alcohol. The resulting non-azeotropic ether/hydrocarbon stream can then be easily separated by distillation to provide the desired alkyl-tert-alkyl ether product and a hydrocarbon product. The cyclic adsorption process employed to separate the alcohol from the ether/hydrocarbon mixture comprises introducing the alcohol/ether/hydrocarbon mixture into a plurality of adsorption colums containing an alcohol selective adsorbent, wherein each respective absorption column undergoes successive steps of adsorption and desorption.

Abstract: A process for the vapor-phase synthesis of non-adduct volatile fluorinated and non-fluorinated metal-ligand complexes comprising contacting a .beta.-diketone or .beta.-ketoimine ligand with an inert carrier gas to vaporize the ligand, reacting the vaporized ligand with a metal species at a temperature sufficient to form the metal-ligand complex and recovering the metal-ligand complex by sublimation. The process is conducted in the absence of solvent thereby providing pure non-adduct metal-ligand complexes. Such complexes are particularly suited for specialty applications requiring use of high purity compounds.

Abstract: The present invention is a concentration swing adsorption process for separating a liquid phase feedstock comprising a more adsorbable component (A) and a less adsorbable component (B) with respect to an adsorbent. The process is operated in a system comprising a single or a plurality of adsorption columns containing the adsorbent which are operated in cycle in a predetermined sequence. The following operational steps are performed in the order recited in each of the adsorption columns in its turn. Feedstock is passed through the adsorbent and the more adsorbable component (A) is selectively adsorbed while a stream enriched in component (B) is discharged from the adsorption column. The adsorbent is rinsed in a direction co-current to the feedstock with the more adsorbable component (A) whereby the less adsorbable component (B) is displaced from the adsorbent and a stream comprising a mixture of the more adsorbable component (A) and the less adsorbable component (B) is withdrawn from the adsorption column.

Abstract: A process for selectively producing ortho-alkylated aromatic amines in high selectivity relative to N-alkylated aromatic amines. The process comprises reacting an aromatic amine, having at least one hydrogen atom in a position ortho to the amine functionality, and an olefin under conditions sufficient to effect an alkylation reaction, in the presence of a zeolite catalyst which has been thermally pretreated by heating the catalyst to a temperature greater than about 500.degree. C. for a period ranging from 0.5 to about 10 hours while sweeping an inert gas over the heated catalyst to remove water and ammonia formed during the thermal treatment, and subsequently recovering the alkylated aromatic amine.

Abstract: A method for profiling the chemical structure and elemental composition as a function of distance below the exterior surface of a thermoplastic article, and more particularly, to a method for determining the depth of permeation of a modifier into the interior of a thermoplastic article which has been treated with the modifier. The method utilizes a pulsed ultraviolet energy source having a fluence level and pulse duration sufficient to ablate material from the article's exterior surface to a series of successive predetermined distances below the exterior surface to expose successive interior surfaces while causing essentially no physical or chemical damage to each respecting interior surface exposed by ablation. The elemental and chemical compositions of each successive interior surface are analyzed by a surface sensitive spectrographic technique and the spectrographic results are compared to determine the depth of modifier permeation within the thermoplastic article.

Abstract: A residue-free fluxing process wherein the active fluxing agent comprises a .beta.-diketone or .beta.-ketoimine ligand. Such ligands react with surface metal oxides on workpieces to be soldered to form volatile metal-ligand complexes as reaction products which are sublimed from the surface leaving essentially no residue on the workpieces. The fluxing agents can be utilized in gas-phase processes wherein the workpieces are contacted with an effective amount of one or more ligands which are dispersed in a carrier gas or solvent or by incorporating the ligands into an alloy-vehicle mixture for use as conventional creams or pastes. The invention eliminates the need for post-reflow cleaning using solvents since no flux residue remains on the workpieces to be soldered following volatilization of the metal-ligand complex.