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: Polyvinylaminals, optionally as the formed copolymer with polyvinyl hemiaminals, and polyvinyl acetals are added to a papermaking pulp slurry to improve the retention of fines in the final paper product. This polymer is provided by reacting a poly(vinylamine) which can be a homopolymer or a copolymer containing vinyl alcohol and vinyl amine units with a monoaldehyde. The aldehyde, such as butyraldehyde, modifies the structure of the polymer and increases its hydrophobicity. The use of these polymers in papermaking involving the recycle of waste papers provides notable advantages in fines retention because of the high level of fines which normally accompany such recycle paper waste.
Type:
Grant
Filed:
January 24, 1992
Date of Patent:
August 3, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
John G. Smigo, Robert K. Pinschmidt, Andrew F. Nordquist, Timothy L. Pickering
Abstract: A method for preparing a polyurethane foam which comprises reacting an organic polyisocyanate and a polyol in the presence of a blowing agent, a cell stabilizer and a catalyst composition consisting essentially of at least one compound of the following formula; ##STR1## where R is hydrogen, c.sub.1 -c.sub.8 alkyl, c.sub.6 -c.sub.10 aryl or c.sub.7 -c.sub.10 aralkyl, and n is 0-3. The preferred catalyst consists essentially of of the compound when n is 0, namely 3-quinuclidinol.
Type:
Grant
Filed:
January 30, 1992
Date of Patent:
August 3, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Mark L. Listemann, Ann C. L. Savoca, Kristen E. Minnich, Kevin R. Lassila
Abstract: Polymeric membranes derived from aromatic polyarylates formed from nitrated dicarboxylic acid chlorides and cardo bisphenol having halo-substituents on all portions ortho to the hydroxyl groups are provided which exhibit high gas permselectivities.
Type:
Grant
Filed:
May 13, 1992
Date of Patent:
August 3, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Ning Chen, Chao-Fong Tien, Stephanie M. Patton
Abstract: A diffusion diluter is described and a method for using such apparatus with a condensation nucleus counter, wherein a particle containing reactive gas is diluted with an inert diluent gas to diminish the reactive character of the particle-containing gas without disturbing the particle concentration of the gas allowing it to be accurately and safely measured for its particle content.
Abstract: This invention relates to an improvement in a process for the separation of a multi-component stream comprising component A, B and C with A being the most volatile and C the least volatile. A multi-component feed is introduced to a multicolumn distillation system comprising a first or main distillation column and a side column wherein at least a light component A is separated from a heavier component C in the main distillation column, the lighter component A being removed as an overhead fraction and the heavier component C being removed as a bottoms fraction. The improvement for enhanced recovery of component B in the side column comprises withdrawing a liquid fraction from the main distillation column at a point intermediate the overhead and feed and introducing that liquid fraction to an upper portion of the side column. Lighter components are withdrawn as an overhead from the side column and returned to an optimal location in the distillation system, typically the main distillation column.
Abstract: The present invention is directed to a bulkhead mounting assembly comprising a bulkhead-securing flange on an integral body having a large diameter externally threaded portion and a small diameter externally threaded portion with the large diameter externally threaded portion engaging a bulkhead-securing nut of sufficient diameter so as to pass over the small diameter externally threaded portion and a conduit-securing nut engaging the small diameter-securing portion and preferably any cap placed on the conduit such as used to secure ultra high purity conditions within the conduit.
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: N-fluoro perfluoroheterocyclic sulfonamides of the following Formula I ##STR1## wherein Het.sub.f represents an aromatic perfluoroheterocyclic radical of valency n and each R independently represents a substituted or unsubstituted C.sub.1 -C.sub.30 alkyl, C.sub.6 -C.sub.14 aryl substituted C.sub.1 -C.sub.10 alkyl, C.sub.6 -C.sub.14 aryl, or C.sub.1 -C.sub.10 alkyl substituted C.sub.6 -C.sub.14 aryl group, are novel electrophilic fluorinating agents. Preferably Het.sub.f is a perfluorinated nitrogen-containing aromatic group, especially pyridyl, pyrimidinyl, pyrazinyl or 1,3,5-triazinyl; n is 1; and R is perfluorinated, especially trifluoromethyl.
Abstract: The invention relates to reaction injection molded elastomers derived from high molecular weight polyether polyols, an aromatic diamine chain extender, a polyisocyanate and a hydroxyl-containing organotin catalyst. The reaction injection molded (RIM) elastomers of this invention are useful, for example, as automobile body parts.
Abstract: A process and system for controlling a cryogenic air separation unit during rapid changes in production. During operation of an air separation unit, demands for oxygen will vary and the pressure of the feed air will fluctuate. The changes in oxygen demand and feed air pressure translate into a ramping, either up or down, of the distillation system pressure in the air separation unit. Because the product streams have tight purity requirements, the ramping system pressure (which could adversely affect product purity) is compensated for. This compensation is by way of a net transfer of refrigeration, in the form of liquid nitrogen, into and out of the distillation system. This transfer of refrigeration is implemented using a storage vessel of liquid nitrogen connected to the reflux path of the distillation system. Liquid nitrogen via the reflux path is removed and stored or added to the distillation system to decrease or increase the refrigeration, respectively.
Type:
Grant
Filed:
June 20, 1991
Date of Patent:
July 6, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Rakesh Agrawal, David M. Espie, Declan P. O'Connor, Jorge A. Mandler, Arthur R. Smith, Donald W. Woodward
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.
Type:
Grant
Filed:
April 1, 1991
Date of Patent:
June 22, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
David A. Roberts, John C. Ivankovits, John A. T. Norman, David A. Bohling
Abstract: A method and apparatus for maintaining a liquid-frozen solid slush mixture in a vessel at a desired total slush mixture and desired solids content during conditions under which the solids in the slush mixture in the vessel are melting. The method comprises introducing fresh slush mixture to the vessel, while removing liquid from the vessel--both at rates directly proportional to the rate of solids melting in the vessel. The apparatus comprises an auxiliary vessel containing slush mixture and means for transferring slush mixture to the main vessel at one rate, means for transferring liquid from the main vessel to the auxiliary vessel at another rate, and means for controlling the transfer rates in a prescribed manner.
Abstract: Method and apparatus for quick freezing particles with surface moisture by immersion in liquid cryogen to produce a frozen crust or layer on the particles followed by agitation in content with the vaporized cryogen to complete freezing and prevent clumping of the particles.
Type:
Grant
Filed:
July 21, 1992
Date of Patent:
June 22, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Edward F. Kiczek, Earl W. Moore, David L. Mitchell, Jr., Kevin S. McAfee
Abstract: Method and apparatus for reducing dehydration during freezing of foodstuffs utilizing a combination of cryogenic freezing to lock in moisture followed by vaporized cryogen assisted mechanical freezing to through freeze other foodstuff.
Abstract: A process for generating in-situ low-cost atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering metal and ceramic powders in a continuous furnace from non-cryogenically produced nitrogen containing up to 5% residual oxygen is presented. The disclosed process involves mixing nitrogen gas containing residual oxygen with a pre-determined amount of a reducing gas such as hydrogen, a hydrocarbon, or a mixture thereof, feeding the gaseous mixture through a non-conventional device into the hot zone of a continuous heat treating furnace, converting residual oxygen to an acceptable form such as moisture, a mixture of moisture and carbon dioxide, or a mixture of moisture, hydrogen, carbon monoxide and carbon dioxide, and using the resultant gaseous mixture for annealing and heat treating metals and alloys, brazing metals and ceramics, sintering metal and ceramic powders, and sealing glass to metals.
Type:
Grant
Filed:
July 8, 1991
Date of Patent:
June 22, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Donald J. Bowe, Brian B. Bonner, Diwakar Garg
Abstract: Fly ash generated from incineration of municipal solid waste (MSW) when placed in landfills under mild acid conditions can leach lead and cadmium. A process for stabilizing heavy metals in this fly ash is presented which involves calcining in the presence of an oxygen containing gas stream at a temperature greater than about 375.degree. C. and substantially less than about 800.degree. C. for times from about 170 seconds up to about 5 hours fly ash which has been subjected to lime scrubbing for acid gas removal. Such treated MSW fly ash will give leachates containing heavy metal concentrations less than the EPA regulatory limit.
Type:
Grant
Filed:
September 10, 1991
Date of Patent:
June 15, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Donald P. Bucci, Francis A. Altemose, II, Nancy C. Easterbrook, Edwin N. Givens, Joseph Klosek, Kenneth D. Tracy, Kai P. Wong
Abstract: Fly ash generated from incineration of municipal solid waste (MSW) when placed in landfills can under mild acid conditions leach lead and cadmium. A process for stabilizing lead in this fly ash is presented which involves calcining a mixture of the fly ash and certain calcium-containing compounds in the presence of an oxygen containing gas stream at a temperature greater than about 475.degree. C. and substantially less than about 800.degree. C. for times from about 30 minutes up to about 5 hours. Such treated MSW fly ash will give leachates containing lead concentrations less than the EPA regulatory limit.
Type:
Grant
Filed:
September 10, 1991
Date of Patent:
June 15, 1993
Assignee:
Air Products and Chemicals, Inc.
Inventors:
Donald P. Bucci, Francis A. Altemose, II, Nancy C. Easterbrook, Edwin N. Givens, Joseph Klosek, Kenneth D. Tracy, Kai P. Wong
Abstract: This invention relates to an improved process for the coproduction of a volatile component with normal purity and ultra high purity from a stream containing other heavier components and contaminated with lighter impurities which are more volatile than the volatile component. The improvement resides in removing a stream of the volatile component which is substantially free of the lighter impurities and then introducing the stream stripped of impurities to a second distillation column for fractionation. The second distillation column is equipped with a rectification section wherein the stream is rectified and the volatile component obtained in ultra high purity as an overhead. The volatile component with normal purity is obtained from the first distillation column as an overhead.