Abstract: A heating, ventilating, and air conditioning (HVAC) system includes a refrigerant loop having a compressor, where the compressor is configured to circulate a refrigerant through the refrigerant loop, a first heat exchanger disposed along the refrigerant loop, where the first heat exchanger is configured to place the refrigerant in a first heat exchange relationship with a working fluid, and an air handling unit having a second heat exchanger, where the second heat exchanger is configured to place the working fluid in a second heat exchange relationship with an airflow, and where the air handling unit is isolated from the first heat exchanger to reduce or eliminate mixing of refrigerant with the airflow.

Abstract: The present invention relates to a composition being an aqueous dispersion of a polyurethane in water, said composition comprising water and the reaction product of (a) a water-dispersible isocyanate-terminated polyurethane prepolymer having an NCO content of between 2.1 and 10% by weight, (b) an organic polyisocyanate adduct mixture comprising a polyisocyanate dimer and a polyisocyanate trimer and having an average isocyanate functionality of between 2.1 and 4.0, and (c) an amine chain extender having a specified ratio of NH2 relative to the NCO index of the polyisocyanate adduct mixture. Also disclosed is a process for preparing this composition, and a method for coating a substrate with the composition.

Abstract: The present invention relates to a composition being an aqueous dispersion of a polyurethane in water, said composition comprising water and the reaction product of (a) a water-dispersible isocyanate-terminated polyurethane prepolymer having an NCO content of between 2.1 and 10% by weight, (b) an organic polyisocyanate adduct mixture comprising a polyisocyanate dimer and a polyisocyanate trimer and having an average isocyanate functionality of between 2.1 and 4.0, and (c) an active hydrogen-containing chain extender. Also disclosed is a process for preparing this composition, and a method for coating a substrate with the composition.

Abstract: The present invention relates to a composition being an aqueous dispersion of a polyurethane in water, said composition comprising water and the reaction product of (a) a water-dispersible isocyanate-terminated polyurethane prepolymer having an NCO content of between 2.1 and 10% by weight, (b) an organic polyisocyanate adduct mixture comprising a polyisocyanate dimer and a polyisocyanate trimer and having an average isocyanate functionality of between 2.1 and 4.0, and (c) an active hydrogen-containing chain extender. Also disclosed is a process for preparing this composition, and a method for coating a substrate with the composition.

Abstract: This invention relates to a catalyst composition comprising the reaction product of (a) an inorganic substrate containing a reactive hydroxyl group and selected from the group consisting of silica compounds, alumina compounds, and combinations thereof, (b) a catalyst containing terminal unsaturation and selected from the group consisting of 4-dialkylamino pyridines, 4-(N-arylalkyl-N-alkyl)amino pyridines, and combinations thereof, and (c) a hydrosilane. Also disclosed is a process for making the catalyst composition, as well as the catalyst composition by empirical structural formula.

Abstract: This invention relates to the production of spandex fibers made from segmented polyurethane(urea)s which are prepared from low unsaturation-containing polyols made by polymerizing alkylene oxides in the presence of a double metal cyanide complex catalyst. With the low unsaturation-containing polyols, spandex fibers can be prepared that have better physical properties than fibers prepared with PTMEG polyols.

Abstract: This invention relates to a process for preparing a dimer by the steps of: (a) cyclodimerizing a polyisocyanate in the presence of a dimerization catalyst which is covalently bound to an insoluble inorganic matrix by contacting said polyisocyanate with said catalyst at a temperature of between about 20 and about 135.degree. C. in a reaction to form an uretidione-containing cyclodimerized isocyanate wherein a portion of the isocyanate moieties comprising said polyisocyanate are converted to uretidione groups, and (b) separating said catalyst from said cyclodimerized isocyanate in order to stop said reaction after a desired amount of isocyanate moieties in said polyisocyanate have been converted to uretidione moieties.

Abstract: This invention relates to a process for preparing a trimer by the steps of: (a) cyclotrimerizing a polyisocyanate in the presence a polymer-bound trimerization catalyst by contacting said polyisocyanate with said catalyst at a temperature of between about 20.degree. and about 135.degree. C. in a reaction to form an isocyanurate-containing cyclotrimerized isocyanate wherein a portion of the isocyanate moieties comprising said polyisocyanate are converted to isocyanurate groups, and (b) separating said catalyst from said cyclotrimerized isocyanate in order to stop said reaction after a desired amount of isocyanate moieties in said polyisocyanate have been converted to isocyanurate moieties.

Abstract: This invention relates to a method of fabricating a thermoplastic elastomer which comprises the steps of: (a) fabricating a polyol having a molecular weight of between about 2,000 and about 8,000 and having a level of end group unsaturation of no greater than 0.02 milliequivalents per gram of polyol, said polyol being fabricated in the presence of a double metal cyanide catalyst, (b) reacting said polyol with a diisocyanate to produce an isocyanate-terminated prepolymer, and (c) reacting said isocyanate-terminated prepolymer with a difunctional isocyanato-reactive chain extender in a mold or in an extruder in order to produce an elastomer characterized by a hardness of between a Shore A hardness of about 50 and a Shore D hardness of about 65. Also claimed is the elastomer produced by the above method utilizing a one-shot technique.

Abstract: This invention relates to a method of fabricating a thermoplastic elastomer which comprises the steps of: (a) fabricating a polyol having a molecular weight of between about 2,000 and about 20,000 and having a level of end group unsaturation of no greater than 0.04 milliequivalents per gram of polyol, said polyol being fabricated in the presence of a double metal cyanide catalyst, (b) reacting said polyol with a diisocyanate to produce an isocyanate-terminated prepolymer, and (c) reacting said isocyanate-terminated prepolymer with a difunctional isocyanato-reactive chain extender in a mold or in an extruder in order to produce a soft elastomer characterized by a Shore A hardness of between about 10 and about 70. Also claimed is the elastomer produced by the above method utilizing a one-shot technique.

Abstract: Thermoplastic compositions are disclosed which comprise blends of about 50 to about 85 percent by weight of a thermoplastic polyurethane and the balance of the blend comprising (a) a polyvinyl halide resin and (b) a diene-nitrile copolymer rubber, the weight ratio of (a) to (b) being within the range of from about 1:4 to about 1.5:1.The novel blends do not melt or spread flaming drip when combusted but rather form chars. The blends are optionally fire retarded by the addition of flame retardants.The fire retarded blends find utility in, inter alia, electric wire and cable jacketing where a high degree of fire retardance is required. The blends without fire retardants provide a good thermoplastic polyurethane at lower cost than the polyurethanes alone and find utility in those applications normally associated with polyurethanes such as films, footwear, wire jacketing, and particularly those applications calling for a higher degree of oil resistance than polyurethanes alone.

Abstract: The use of polyisocyanates as binders in the preparation of particle boards is subject to the drawback that the boards exhibit a tendency to adhere to the face of the platens used in their formation. This problem is minimized by utilizing, in association with the polyisocyanate to be used as binder, minor amounts of one or more phosphates or thiophosphates of the formula: ##STR1## where R=alkyl (C.sub.3 and higher), alkenyl (C.sub.3 and higher), aryl, alkyl-substituted aryl, ##STR2## (where R.sub.2 is alkyl, aryl, or alkyl-substituted aryl, A and B are H, methyl, chloromethyl, 2,2,2-trichloromethyl, m=1-25) and lower-alkyl substituted by from 1 to 2 acyloxy groups where acyl is the residue of an aliphatic carboxylic acid having at least 2 carbon atoms; R.sub.1 is Cl, Br, lower-alkoxy, lower-alkylmercapto, arylamino, mono(lower-alkyl)amino, di(lower-alkyl)amino, hydroxy(lower-alkylene)oxy, aryloxy, hydrocarbylureido, and an enol residue; X=O or S and n=1 or 2.

Abstract: A process is described for the preparation of a polymer having a recurring unit of the formula: ##STR1## where R is hydrogen or methyl, C.sub.n H.sub.2n is lower-alkylene, R.sub.1 and R.sub.2 are aryl or lower-alkyl, and x is 0 or 1. A polymer having a recurring unit of the formula: ##STR2## where X is chloro, bromo, iodo, chloroalkyl, bromoalkyl or iodoalkyl, is reacted with the appropriate aryl or alkyl chloride or bromide and arsenic trichloride, arsenic tribromide or arsenic trioxide in the presence of sodium, magnesium, or lithium metal. The resulting polymer is an intermediate in the preparation, by oxidation, of the corresponding As-oxide which polymer is useful as a catalyst for the conversion of isocyanates to the corresponding carbodiimides.

Abstract: A process is described for the preparation of a polymer having a recurring unit of the formula: ##STR1## where R is hydrogen or methyl, C.sub.n H.sub.2n is lower-alkylene, R.sub.1 and R.sub.2 are aryl and x is 0 or 1. A polymer having a recurring unit of the formula: ##STR2## where X is chloro, bromo, iodo, chloroalkyl, bromoalkyl or iodoalkyl, is reacted with a triarylarsine in the presence of lithium or sodium-potassium alloy. The resulting polymer is an intermediate in the preparation, by oxidation, of the corresponding As-oxide. The latter is useful as a catalyst for the conversion of isocyanates to the corresponding carbodiimides.

Abstract: Bis(2-hydroxyalkyl) N,N-di(lower-alkyl)aminomethyl-phosphonates are described. These phosphorus-containing polyols can be incorporated into polyurethane foams to render the latter fire retardant. They have the advantage over closely related phosphorus-containing polyols that they are autocatalytic in the polyurethane foam forming reaction and that they can be mixed with the polyol component of the polyurethane foam forming composition to give a mixture (premix) which can be maintained in storage for prolonged periods without showing any signs of deterioration.

Abstract: Bis(2-hydroxyalkyl) N,N-di(lower-alkyl)aminomethylphosphonates are described. These phosphorus-containing polyols can be incorporated into polyurethane foams to render the latter fire retardant. They have the advantage over closely related phosphorus-containing polyols that they are autocatalytic in the polyurethane foam forming reaction and that they can be mixed with the polyol component of the polyurethane foam forming composition to give a mixture (premix) which can be maintained in storage for prolonged periods without showing any signs of deterioration.

Abstract: Bis(2-hydroxyalkyl) N,N-di(lower-alkyl)aminomethylphosphonates are described. These phosphorus-containing polyols can be incorporated into polyurethane foams to render the latter fire retardant. They have the advantage over closely related phosphorous-containing polyols that they are autocatalytic in the polyurethane foam forming reaction and that they can be mixed with the polyol component of the polyurethane foam forming composition to give a mixture (premix) which can be maintained in storage for prolonged periods without showing any signs of deterioration.

Abstract: An improved process for the preparation of thermoplastic polyurethane elastomers by a one-shot reaction of an organic diisocyanate, a polymeric diol, and a diol extender is disclosed wherein the diol components, either singly or together, are treated with a trivalent phosphorus compound prior to their reaction with the diisocyanate in the presence of a stannous tin urethane catalyst. The process when carried out with pure urethane grade diol components results in very efficient catalysis which in turn requires lower levels of stannous tin catalyst than would otherwise be employed. Moreover, the process can be carried out with diol components that are not urethane grade materials but which are contaminated by high levels of peroxidic impurities and which materials would otherwise be useless for the preparation of high grade elastomer products.

Abstract: An improved process is described for the reaction of an isocyanate (mono or poly) with a carboxylic acid or anhydride (mono or poly) to form the corresponding imide, amide or amide-imides. The improvement lies in using as the catalyst the 1-oxide, 1-sulfide or 1-hydrocarbylimino derivative of a phospholene, phospholane or phosphetane. The latter compounds are also substituted in the 1-position by a hydrocarbyl (C.sub.1-12) or halohydrocarbyl (C.sub.1-12) and may additionally carry one or more halo, lower-alkoxy, phenoxy, lower-hydrocarbyl or halo-substituted hydrocarbyl groups on the ring carbon atoms.

Abstract: A process is described for converting organic polyisocyanates to carbodiimide-containing polyisocyanates by heating said organic polyisocyanates in the presence of an organoarsine-substituted polystyrene carbodiimide-forming catalyst until a desired level of conversion is achieved, followed by separation of catalyst from product. It is thus possible to obtain a carbodiimide-containing polyisocyanate which is free from catalyst and hence free from the possibility that carbodiimide formation can continue on storage of the product. In a particular embodiment the process is employed to convert methylenebis(phenyl isocyanate), which is normally solid at ambient temperatures, to a storage stable liquid product. The polymeric catalysts employed in the process are characterized by a recurring unit of the formula: ##STR1## wherein R.sub.1 and R.sub.2 are hydrocarbyl, R.sub.3 is hydrogen, chloro or methyl, R.sub.4 is hydrogen or methyl and n is 0 or 1.