For Inhibiting Or Preventing A Polymerization Reaction Patents (Class 203/8)
  • Patent number: 9221738
    Abstract: The present invention relates to a process for purifying monomers, by evaporating at least a portion of the monomers present in a starting composition and then condensing it, which is characterized in that at least a portion of the starting composition is evaporated in a short-path evaporator, the mass flow density of the vapors {dot over (m)} being selected according to the relation (I) m . ? 1800 ? kg · K mbar · m 2 · h · kg kmol · p i · ( M ~ T ) 0.5 ( I ) in which {tilde over (M)} is the average molar mass of the vapors in the short-path evaporator in kg/kmol T is the temperature of the vapors in K pi is the pressure in the short-path evaporator in mbar {dot over (m)} is the mass flow density of the vapors in kg/(m2·h). A further aspect of the present invention is a plant for performing the process.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: December 29, 2015
    Assignee: Evonik Röhm GmbH
    Inventors: Dirk Broell, Christian Maul, Benedikt Laux, Volker Schleep
  • Patent number: 8771476
    Abstract: High temperatures and oxygen exposure during extractive distillation can result in polymerization of vinyl aromatic compounds. In various embodiments, the present disclosure relates to methods for inhibiting polymerization of vinyl aromatic compounds during extractive distillation. In various embodiments, the methods include a) providing a mixture containing at least one vinyl aromatic compound, b) adding at least one dinitrophenol inhibitor to the mixture, and c) after step b), performing an extractive distillation on the mixture to isolate the at least one vinyl aromatic compound. Purified styrene can be isolated by the methods described herein. In some embodiments, the dinitrophenol inhibitor is 2-sec-butyl-4,6-dinitrophenol (DNBP).
    Type: Grant
    Filed: February 15, 2010
    Date of Patent: July 8, 2014
    Assignee: GTC Technology LP
    Inventors: Amy Sealey, George A. Ball, B. Bryant Slimp, Jr.
  • Publication number: 20130206577
    Abstract: For the distillation of temperature-sensitive liquids, in particular acrylic acid and its esters, the liquid is heated in a column and at least partly evaporated. The vapor is guided through a condenser provided inside the column, in which the vapor is at least partly condensed. The condensed liquid is at least partly withdrawn from the column. The distillation is characterized in that the vapor not condensed yet is guided through the condenser cocurrently to the condensed liquid.
    Type: Application
    Filed: June 8, 2011
    Publication date: August 15, 2013
    Applicant: Lurgi GmbH
    Inventors: Jochen Bauer, Frank Castillo-Welter, Klaus Kirsten, Markus Kreich, Christoph Steden, Dominic Walter, Rudolf Zeyen
  • Patent number: 8491758
    Abstract: A process for inhibiting polymerization of (meth)acrylic acid and/or (meth)acrylic esters by introducing an oxygenous gas into the (meth)acrylic acid and/or the (meth)acrylic ester, in which the (meth)acrylic acid and/or the (meth)acrylic ester has a degree of purity of at least 95% and is in the liquid state.
    Type: Grant
    Filed: December 9, 2010
    Date of Patent: July 23, 2013
    Assignee: BASF SE
    Inventors: Gunter Lipowsky, Steffen Rissel, Volker Schliephake, Ulrich Jäger, Sylke Haremza
  • Publication number: 20130098752
    Abstract: In a process for distilling polymerization-prone compounds from liquid mixtures of matter which, apart from the readily polymerizable compound, also contain other components and also polymerization inhibitors, the evaporator is operated in forced circulation and at a pressure which makes possible superheating of the liquid with respect to its boiling point at the pressure within the distillation column. This is achieved by transporting the superheated liquid against a flow restrictor, e.g. an orifice plate. The liquid which is expanded and partially evaporated on passage through the flow restrictor is returned to the distillation column. In this manner the formation of an open vapour space in the evaporator circuit after heating downstream of the heat exchanger is avoided in that, in the design of the evaporator of the prior art, formation of polymer deposits frequently occurs.
    Type: Application
    Filed: January 28, 2011
    Publication date: April 25, 2013
    Applicant: LURGI GMBH
    Inventors: Frank Castillo-Welter, Klaus Kirsten, Jochen Bauer, Christoph Steden, Dominic Walter, Markus Kreich, Rudolpf Zeyen
  • Publication number: 20130012736
    Abstract: An improvement in the production of methylidene malonates is attained by use of specific reaction phase and/or separation phase polymerization inhibitors and combinations thereof.
    Type: Application
    Filed: September 15, 2012
    Publication date: January 10, 2013
    Applicant: OptMed, Inc.
    Inventors: Bernard M. Malofsky, Chris Mariotti
  • Publication number: 20130008773
    Abstract: Novel improved processes for the production and isolation of methylidene malonates via direct and indirect adduct processes.
    Type: Application
    Filed: September 15, 2012
    Publication date: January 10, 2013
    Applicant: OPTMED, INC.
    Inventors: Bernard M. Malofsky, Chris Mariotti
  • Patent number: 8337671
    Abstract: Process for distillatively purifying polymerizable compounds using a high-boiling, inert, thermally long-term-stable substance as a boiling oil, characterized in that the boiling oil is disposed in the bottom of a rectification column.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: December 25, 2012
    Assignee: Evonik Röhm GmbH
    Inventors: Dirk Broell, Hermann Siegert
  • Publication number: 20120205234
    Abstract: The present invention provides a method for preventing polymerization, and a polymerizable monomer composition favorably used therefor that includes a (meth)acryloyl group-containing isocyanate compound and a specific polymerization inhibitor. The polymerizable monomer composition includes a (meth)acryloyl group-containing isocyanate compound and a stable free radical compound. The invention effectively prevents the polymerization of the (meth)acryloyl group-containing isocyanate compound and the occurrence of polymers due to the polymerization. Furthermore, the use of a stable free radical compound which has a vapor pressure approximate to that of the (meth)acryloyl group-containing isocyanate compound can effectively prevent polymerization in a vapor phase and a condensation phase of distillation facility.
    Type: Application
    Filed: March 2, 2012
    Publication date: August 16, 2012
    Applicant: SHOWA DENKO K.K.
    Inventors: Norihito NISHIMURA, Katsutoshi OHNO, Tetsuhiro FURUKAWA
  • Patent number: 8157969
    Abstract: Accumulation of polymer on equipment, which is in contact with polymerizable material during normal process operation, is minimized by the method and apparatus of the present invention. The method involves positioning and affixing the equipment, such as a pressure relief device, to process apparatus, such as a distillation column, proximate to a wetted region comprising liquid phase fluid in the process apparatus, such that the moving liquid phase fluid is at least intermittently in contact with the equipment and one or more of accumulated polymerizable material, condensate comprising same, and polymer, is washed off of the equipment.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: April 17, 2012
    Assignee: Rohm and Haas Company
    Inventors: Barnett John O., Michael Stanley DeCourcy, Michael W. Hurley
  • Patent number: 8118995
    Abstract: A method for inhibiting the formation of fouling materials including contacting hydrocarbon media containing aldehyde compounds with an antifoulant while treating the hydrocarbon media with a basic wash. The antifoulant includes a reducing sugar.
    Type: Grant
    Filed: March 31, 2009
    Date of Patent: February 21, 2012
    Assignee: General Electric Company
    Inventors: Mary King, Cato Russell McDaniel
  • Publication number: 20120000764
    Abstract: The present invention relates to a process for purifying monomers, by evaporating at least a portion of the monomers present in a starting composition and then condensing it, which is characterized in that at least a portion of the starting composition is evaporated in a short-path evaporator, the mass flow density of the vapours {dot over (m)} being selected according to the relation (I) m . ? 1800 ? kg · K mbar · m 2 · h · kg kmol · p i · ( M ~ T ) 0.5 ( I ) in which {tilde over (M)} is the average molar mass of the vapours in the short-path evaporator in kg/kmol T is the temperature of the vapours in K pi is the pressure in the short-path evaporator in mbar {dot over (m)} is the mass flow density of the vapours in kg/(m2·h). A further aspect of the present invention is a plant for performing the process.
    Type: Application
    Filed: March 26, 2010
    Publication date: January 5, 2012
    Inventors: Dirk Broell, Christian Maul, Benedikt Laux, Volker Schleep
  • Patent number: 8080140
    Abstract: A process for debottlenecking a system for the separation of a conjugated diolefin the system including a first extraction section having an extractive distillation column and a stripping column and a second extraction section. The process includes the steps of withdrawing a first portion of an extract from the extractive distillation column, the extract having at least the first portion and a second portion, and transferring the first portion of the extract to a flash/separation vessel; separating the first portion of the extract into a vapor phase and a liquid phase by flashing in a flash/separation vessel; and combining the liquid phase of the separated first portion of the extract with the second portion of the extract to produce an extract feed for further processing. A system and process for the separation of a conjugated diolefin from a C4- or C5-hydrocarbon mixture containing the conjugated diolefin and higher acetylenes are also provided.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: December 20, 2011
    Assignee: Exxonmobil Chemical Patents Inc.
    Inventors: May-Ru Chen, Micheal E. Smith, Ross T. Garner
  • Publication number: 20110290635
    Abstract: The present invention relates to a polymerization inhibitor composition and a method of inhibiting polymerization of distillable monomers in liquid and evaporated/condensed phases with the polymerization inhibitor composition. The polymerization inhibitor composition is useful for inhibiting polymerization of the distillable monomers during manufacture, purification (e.g., distillation), handling, and storage thereof.
    Type: Application
    Filed: February 18, 2010
    Publication date: December 1, 2011
    Inventors: Kishore K. Kar, Michael D. Cloeter, Olan Stanley Fruchey, Richard S. Harner, Krzysztof Matyjaszewski, Renaud Nicolay, Jaroslav Mosnacek
  • Patent number: 7981255
    Abstract: There is provided a method for rectifying a vinyl compound liquor. The method includes the steps of a) providing a rectification column operated at a temperature and pressure and b) feeding the vinyl compound liquor to be rectified into the rectification column, wherein the pressure of the rectification column and the temperature of the fed vinyl compound liquor are controlled, such that the temperature of the fed vinyl compound liquor ranges from its bubble point at the pressure of the rectification column to 10° C. lower than the bubble point.
    Type: Grant
    Filed: September 26, 2007
    Date of Patent: July 19, 2011
    Assignee: Shanghai HuaYi Acrylic Acid Co., Ltd.
    Inventors: Jingming Shao, Jun Yin, Shuju Liu, Xiaodong Chu, Shengxian Xu
  • Patent number: 7892403
    Abstract: A condenser includes: a top face of a tube plate on which acrylic acid may be condensed inside the condenser; a spray for spreading a polymerization inhibitor on the tube plate; a first polymerization inhibitor supply tube for supplying the polymerization inhibitor to the spray; and a supporter for supporting the spray at a predetermined position. The supporter supports the first polymerization inhibitor supply tube outside the condenser. The condenser allows a stable continuous operation for a long period of time by preventing polymerization of an easily polymerizable compound in the condenser into which a vapor of an easily polymerizable compound is supplied with a simple structure thereof.
    Type: Grant
    Filed: September 7, 2004
    Date of Patent: February 22, 2011
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Shuhei Yada, Yasushi Ogawa, Yoshiro Suzuki, Kimikatsu Jinno
  • Patent number: 7476299
    Abstract: A decomposition reaction apparatus or distillation apparatus for acrylic acid in which a column bottom liquid heated in a reboiler (5) is supplied from a supply port (1a) provided on a side wall of a column body (1) having: a top plate (12a) above the supply port (1a); and an impingement plate (12b) provided vertically to the top plate (12a), for preventing scattering of the column bottom liquid to a supply direction. The top plate (12a) is provided such that the top face of the top plate (12a) is inclined downward from a base end to a tip end. The present invention allows: suppression of formation of a polymerized product due to flowing of a liquid or gas heated in a reboiler into a column with a simple structure; and a stable continuous operation of column equipment over a long period of time.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: January 13, 2009
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Shuhei Yada, Yasushi Ogawa, Yoshiro Suzuki, Kenji Takasaki
  • Patent number: 7473338
    Abstract: A distillation apparatus for subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify it, the distillation apparatus having a distillation column and a vacuum generator and an exhaust gas conduit of the vacuum generator connected to a connecting conduit therebetween through a pressure control valve. A method provides purifying of a readily polymerizable compound by subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify it, the method including using a distillation apparatus having a distillation column and a vacuum generator and an exhaust gas conduit of the vacuum generator connected to a connecting conduit therebetween through a pressure control valve and controlling the action of the pressure control valve based on a pressure of the distillation column.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: January 6, 2009
    Assignee: Mitsubishi Chemical Corporation
    Inventors: Shuhei Yada, Yasushi Ogawa, Yoshiro Suzuki, Kenji Takasaki, Kiyoshi Takahashi
  • Publication number: 20080119627
    Abstract: Disclosed are reduced pressure distillation methods for purifying siloxanyl monomers in the presence of at least one polymerization inhibitor. In further aspects, the polymerization inhibitor can be an alkylhydroquinone or a hydroxynaphthalene. Also disclosed are compounds purified by the disclosed methods and polymers produced therefrom. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
    Type: Application
    Filed: March 2, 2007
    Publication date: May 22, 2008
    Inventors: Masataka Nakamura, Takehiro Kohara, Hiroya Koyama, Shinya Kiguchi
  • Patent number: 7351310
    Abstract: A process for rectificatively separating fluids including (meth)acrylic monomers in a rectification column by directly cooling the vapor including (meth)acrylic monomers rising to the top of the rectification column to form top condensate including (meth)acrylic monomers, the condensation space at the top of the column being separated from the region of the rectification column containing the separating internals only by at least one chimney tray from which the top condensate formed is removed from the rectification column, which includes effecting the direct cooling of the vapor in the condensation space in at least two spray zones which are spatially successive and are flowed through by vapor by spraying supercooled top condensate including added polymerization inhibitor, and the temperature of the sprayed supercooled top condensate becoming lower from spray zone to spray zone in the flown direction of the vapor.
    Type: Grant
    Filed: September 10, 2003
    Date of Patent: April 1, 2008
    Assignee: BASF Aktiengesellschaft
    Inventors: Joachim Thiel, Albrecht Dams, Juergen Schroeder
  • Patent number: 7304176
    Abstract: It is an object of the present invention to provide a process for producing easily polymerizable substance, which can realize stable operation of a purification system, and can stably maintain a production amount by avoiding production stoppage, upon production of an easily polymerizable substance in plural reactors. The present invention is directed to a process for producing easily polymerizable substance, which comprises mixing easily polymerizable substances obtained in plural reactors in advance, and supplying the mixture to a purification apparatus.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: December 4, 2007
    Assignee: Nippon Shokubai Co., Ltd.
    Inventor: Takeshi Nishimura
  • Patent number: 7282118
    Abstract: This invention resides in providing a method for the prevention of possible polymerization of the easily polymerizable substance during the purification thereof by a column provided with (a) at least one tray directly fixed to a support ring with a bolt and a nut and/or (b) at least one tray fixed to a support ring with a vertical clamp or a distillation column provided in the lower part thereof with a splash collision plate.
    Type: Grant
    Filed: April 6, 2001
    Date of Patent: October 16, 2007
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Tetsuji Mitsumoto, Takeshi Nishimura, Sei Nakahara, Hidefumi Haramaki
  • Patent number: 7279075
    Abstract: In a thermal separating process between at least one gaseous and at least one liquid stream, of which at least one comprises (meth)acrylic monomers, in a separating column containing sieve trays as separating internals, at least some of the sieve trays are operated above an entrainment fraction of 10% by weight.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: October 9, 2007
    Assignee: BASF Aktiengesellschaft
    Inventors: Joachim Thiel, Hugues Vandenmersch, Juergen Schroeder, Albrecht Dams
  • Patent number: 7235158
    Abstract: A perforated tray without downcomer having only a small deviation between the opening ratio based on the diameter of a column and the actual opening ratio and a perforated tray column without downcomer formed by disposing such perforated trays without downcomer are provided. The perforated trays without downcomer are characterized by having a ratio of (A)/(B) in the range of 1.1-1.5, wherein A denotes the opening ratio found from the standard pitch between centers of holes and (B) denotes the opening ratio based on the diameter of a column.
    Type: Grant
    Filed: July 17, 2002
    Date of Patent: June 26, 2007
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Yukihiro Matsumoto, Kazuhiko Sakamoto, Kenji Sanada
  • Patent number: 7179875
    Abstract: In a process for preparing water-absorbent resins based on acrylic acid, crude acrylic acid is firstly isolated from the reaction gases from the catalytic gas-phase oxidation of propane, propylene and/or acrolein. This is treated with an aldehyde scavenger and pure acrylic acid is separated by distillation from the treated crude acrylic acid, and this pure acrylic acid can be subjected directly to a free-radical polymerization.
    Type: Grant
    Filed: August 2, 2002
    Date of Patent: February 20, 2007
    Assignee: BASF Aktiengesellschaft
    Inventors: Eberhard Fuchs, Hans Martan, Gerhard Nestler, Klaus Joachim Mueller-Engel
  • Patent number: 7150809
    Abstract: (Meth)acrylic monomers are separated by a thermal separation process by ascending at least one ascending gaseous stream in a separating column containing a sequence of mass transfer trays and a liquid stream that contains dissolved polymerization inhibitor which descends in the separating column, and in at least one of the streams being (meth)acrylic monomers; and spraying the inner surface of the separating column with the descending liquid stream that contains the dissolved polymerization inhibitor, and the separating column having internals, certain areas of which are shadow regions of the sprayed descending liquid stream; and which shadow regions are equipped by covering means which prevent contact of the shadow regions with (meth)acrylic monomers and consequently undesired polymerization of monomer.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: December 19, 2006
    Assignee: BASF Aktiengesellschaft
    Inventors: Volker Diehl, Ulrich Jaeger, Ulrich Hammon, Juergen Schroeder, Steffen Rissel
  • Patent number: 7128826
    Abstract: Quinone methide derivatives such as 4-benzylidene-2,6-di-tert-butyl-cyclohexa-2,5 dienone are used to inhibit styrene monomer polymerization in the dehydrogenator portion of a styrene monomer production system. The inhibitor contacts the dehydrogenation effluent and does not partition in substantial amounts to the aqueous phase that is separated in the phase separator.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: October 31, 2006
    Assignee: General Electric Company
    Inventors: Sherif Eldin, Ronnie L. Deason, John Link, Tiffany N. Morris
  • Patent number: 7128813
    Abstract: A process for the high yield production of high purity glacial methacrylic acid (“HPMAA”) with minimization of decomposition of hydroxy isobutyric acid (HIBA). The HPMAA is substantially pure, specifically 99% pure or greater with a water content of 0.05% or less. This improved process involves the steps of providing a crude MAA stream which was formed by hydrolyzing acetone cyanohydrin and, therefore, includes HIBA which is an intermediate product of the hydrolysis reaction, and purifying that crude methacrylic acid stream in a series of successive distillation steps.
    Type: Grant
    Filed: April 22, 2003
    Date of Patent: October 31, 2006
    Assignee: Rohm and Haas Company
    Inventors: Keith Frederick Briegel, James Clarence Day, Michael Stanley DeCourcy, Donald Alan Ebert, Jamie Jerrick John Juliette
  • Patent number: 7125475
    Abstract: Inhibitor blends that include both nitrosophenols and nitrosoanilines, optionally in combination with air or oxygen, reduce the premature polymerization of ethylenically unsaturated monomers. unsaturated monomers.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: October 24, 2006
    Assignee: Crompton Corporation
    Inventor: Brigitte Benage
  • Patent number: 7119224
    Abstract: A process for preparing and/or working up mixtures by (meth)acrylic acid and/or (meth)acrylic ester in the presence of at least one polymerization inhibitor and at least one oxygenous gas, which comprises metering in at least part of the oxygenous gas at an exit rate of at least 50 mm/s.
    Type: Grant
    Filed: September 2, 2003
    Date of Patent: October 10, 2006
    Assignee: BASF Aktiengesellschaft
    Inventors: Juergen Schroeder, Frank Hoefer, Sylke Haremza, Gerhard Wagenblast, Volker Schliephake, Ulrich Jaeger, Harald Keller, Cedric Dieleman
  • Patent number: 7081185
    Abstract: The object of this invention to provide an improved arrangement that enables to prevent adhesion of polymer on or around the inner wall of a purification apparatus directly equipped on the outer wall thereof with an attachment such as a support by suppressing local temperature lowering inside the apparatus due to the existence of the attachment. The present invention provides a purification apparatus comprising an attachment directly mounted on an outer wall of the apparatus; and a covering material made of a low heat conductive material which partly or entirely covers the outer wall of the apparatus, and which partly or entirely covers the attachment.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: July 25, 2006
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Yukihiro Matsumoto, Takeshi Nishimura
  • Patent number: 7048834
    Abstract: The present invention provides an industrially easy and economical method for purification of acrylic acid which enables to efficiently eliminate impurities from a crude acrylic acid containing aldehydes as the impurities while the formation of acrylic acid polymer is inhibited. The method for purification of acrylic acid includes the step of distilling a crude acrylic acid which is charged with an aldehyde treatment chemical, wherein the concentration ratio of furfural to acrolein by weight in the crude acrylic acid is adjusted so as to satisfy the following equation: (furfural concentration by weight)/(acrolein concentration by weight)?100.
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: May 23, 2006
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Yoshitake Ishii, Kouji Ueno, Kazuhiko Sakamoto, Sei Nakahara, Masatoshi Ueoka, Tetsuji Mitsumoto, Takeshi Nishimura, Mamoru Takamura, Hisao Nakama
  • Patent number: 7029556
    Abstract: The invention concerns a method of purifying a (meth) acrylic monomer selected among (meth) acrylic acids and their esters, by distillation in the presence of at least a polymerisation inhibitor requiring input of oxygen and/or an inhibitor having better efficacy in the presence of oxygen for stabilizing the liquid phase. The invention is characterized in that the distillation is performed in the presence of a NO2 gas, with an oxygen/organic vapor (p/p) ratio ranging between 0.02 and 3%, and with a NO2 condensed organic vapor (p/p) ratio ranging between 0.01 and 50 ppm.
    Type: Grant
    Filed: November 15, 2000
    Date of Patent: April 18, 2006
    Assignee: Arkema
    Inventors: Michel Fauconet, Stephane Lepizzera
  • Patent number: 7022220
    Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds. Also disclosed is a composition of matter comprising: A) an ethylenically unsaturated monomer and B) an effective inhibiting amount, sufficient to prevent premature polymerization during distillation or purification of said ethylenically unsaturated monomer, of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds used together with an effective amount of oxygen or air to enhance the inhibiting activity of said inhibitor.
    Type: Grant
    Filed: November 10, 2003
    Date of Patent: April 4, 2006
    Assignee: Uniroyal Chemical Company, Inc.
    Inventors: Brigitte Benage, Gerald J. Abruscato, Andrew J. Eisenstein
  • Patent number: 7014736
    Abstract: An apparatus and a process for purification of an acrylic acid family.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: March 21, 2006
    Assignee: Nippon Shokubai Co., Ltd.
    Inventor: Yukihiro Matsumoto
  • Patent number: 6926820
    Abstract: A method of inhibiting fouling and viscosity increase in hydrocarbon streams including ethylenically unsaturated monomers is disclosed. The method includes the step of adding to the hydrocarbon stream an effective amount of one or more quinone methides of the formula: wherein R1, R2, and R3 are independently selected from the group consisting of H, —OH, —SH, —NH2, alkyl, cycloalkyl, heterocyclo, and aryl.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: August 9, 2005
    Assignee: G.E. Betz, Inc.
    Inventors: Sherif Eldin, Grace B. Arhancet
  • Patent number: 6902663
    Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds. Also disclosed is a composition of matter comprising: A) an ethylenically unsaturated monomer and B) an effective inhibiting amount, sufficient to prevent premature polymerization during distillation or purification of said ethylenically unsaturated monomer, of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds used together with an effective amount of oxygen or air to enhance the inhibiting activity of said inhibitor.
    Type: Grant
    Filed: November 10, 2003
    Date of Patent: June 7, 2005
    Assignee: Uniroyal Chemical Company, Inc.
    Inventors: Brigitte Benage, Gerald J. Abruscato, Andrew J. Eisenstein
  • Patent number: 6899806
    Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of: A) at least one first inhibitor selected from the group consisting of C-nitrosoaniline compounds; and B) at least one second inhibitor selected from the group consisting of quinone alkides, nitroaromatic compounds, hydroxylamine compounds, phenylenediamine compounds, quinone compounds, and hydroquinone compounds. Also disclosed is a composition of matter comprising: A) at least one member selected from the group consisting of C-nitrosoaniline compounds; and B) at least one member selected from the group consisting of quinone alkides, nitroaromatic compounds, hydroxylamine compounds, phenylenediamine compounds, quinone compounds, and hydroquinone compounds.
    Type: Grant
    Filed: November 10, 2003
    Date of Patent: May 31, 2005
    Assignee: Uniroyal Chemical Company, Inc.
    Inventors: Brigitte Benage, Gerald J. Abruscato, Andrew J. Eisenstein
  • Patent number: 6878239
    Abstract: A process for inhibiting a polymerization of an easily polymerizable compound purification system is disclosed. According to the present invention, the polymerization of the easily polymerizable compound such as (meth)acrylic acid and (meth)acrylate flowed into a vacuum section can be inhibited by contacting a liquid containing a polymerization inhibitor with the compound directly in the vacuum section. When the vacuum section includes a gas and liquid contact chamber (usually a condenser), the liquid containing a polymerization inhibitor may be supplied to the chamber. When the vacuum section includes a liquid ejector and/or a nash pump as a vacuuming device, the liquid containing a polymerization inhibitor may be circulated by the liquid ejector and/or the nash pump for reducing a pressure of a purifying section. Examples of easily polymerizable compounds are (meth)acrylic acid and (meth)acrylates.
    Type: Grant
    Filed: June 5, 2000
    Date of Patent: April 12, 2005
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Yukihiro Matsumoto, Takeshi Nishimura
  • Patent number: 6863779
    Abstract: A process for the distillation of vinylaromatic monomers in the presence of 4-tert-butylcatechol (TBC) and oxygen, wherein no aromatic nitro or amino compound is present in any effective amount. The process is particularly suitable for destabilizing and purifying styrene which has been stabilized with 4-tert-butylcatechol (TBC) for transportation.
    Type: Grant
    Filed: August 6, 2001
    Date of Patent: March 8, 2005
    Assignee: BASF Aktiengesellschaft
    Inventors: Paulus Schmaus, Werner Georg Metzger
  • Patent number: 6835288
    Abstract: A process for preventing undesired polymerization is conducted by maintaining an effective concentration of a stabilizer which comprises N-oxyl radicals in a mixture containing ethylenically unsaturated compounds, wherein (i) an electronic signal which correlates with the concentration of the N-oxyl radicals in the mixture is obtained periodically or continuously, (ii) the electronic signal is compared with a reference value, and (iii) addition of a stabilizer to the mixture is controlled according to the comparison (ii). The signal is preferably obtained by ESR measurement. The process permits efficient use of the stabilizer.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: December 28, 2004
    Assignee: BASF Aktiengesellschaft
    Inventors: Heinz Friedrich Sutoris, Konrad Mitulla
  • Publication number: 20040222077
    Abstract: In a distillation apparatus, a production process and a purification method of readily polymerizable compounds, a problem of the invention is to solve a serious plugging problem in a large-sized distillation column as in the commercial equipment and to provide an apparatus and a method for distilling and purifying a readily polymerizable compound stably over a long period of time.
    Type: Application
    Filed: February 20, 2004
    Publication date: November 11, 2004
    Applicant: MITSUBISHI CHEMICAL CORPORATION
    Inventors: Shuhei Yada, Yasushi Ogawa, Yoshiro Suzuki, Kenji Takasaki, Kiyoshi Takahashi
  • Publication number: 20040206617
    Abstract: Thermal separating process between at least one gaseous and at least one liquid stream, of which at least one comprises (meth)acrylic monomers, in a separating column whose separating internals are mass transfer trays, in which the liquid stream is polymerization-inhibited and used for spraying the surface of the separating column, and internal surfaces which are in the shadow region of the spraying are removed from the shadow region by covering.
    Type: Application
    Filed: April 14, 2004
    Publication date: October 21, 2004
    Applicant: BASF Aktiengesellschaft
    Inventors: Volker Diehl, Ulrich Jager, Ulrich Hammon, Jurgen Schroder, Steffen Rissel
  • Publication number: 20040104146
    Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds.
    Type: Application
    Filed: November 10, 2003
    Publication date: June 3, 2004
    Applicant: Uniroyal Chemical Company, Inc.
    Inventors: Brigitte Benage, Gerald J. Abruscato, Andrew J. Eisenstein
  • Publication number: 20040089586
    Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds.
    Type: Application
    Filed: November 10, 2003
    Publication date: May 13, 2004
    Applicant: Uniroyal Chemical Company, Inc.
    Inventors: Brigitte Benage, Gerald J. Abruscato, Andrew J. Eisenstein
  • Publication number: 20040050679
    Abstract: (Meth)acrylic acid is worked up in the presence of at least one stabilizer by a process in which a stabilizer-containing mixture originating from the working-up and substantially freed from (meth)acrylic acid is passed into a distillation apparatus and a stabilizer-containing low boiler stream obtained from said apparatus is recycled to the working-up.
    Type: Application
    Filed: June 23, 2003
    Publication date: March 18, 2004
    Inventors: Ulrich Hammon, Heinz Friedrich Sutoris, Jurgen Schroder, Volker Schliephake
  • Patent number: 6695928
    Abstract: A method for the production of (meth)acrylic acid and/or a (meth)acrylic ester is provided. This method for the production of (meth)acrylic acid and/or a (meth)acrylic ester includes washing the device constructed for the production thereof with a basic solution and subsequently rinsing them with a solvent for the purpose of removing solid substances such as polymer and precipitate which occur during the production of (meth)acrylic acid and/or a (meth)acrylic ester.
    Type: Grant
    Filed: March 1, 2000
    Date of Patent: February 24, 2004
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Sei Nakahara, Takeshi Nishimura, Masatoshi Ueoka
  • Publication number: 20040031674
    Abstract: A process for working up mixtures containing (meth)acrylic acid and/or (meth)acrylic ester in a column for distilling, rectifying and/or fractionally condensing in the presence of at least one polymerization inhibitor and an oxygen-containing gas, wherein the partial oxygen pressure p(O2) in the gas phase of the entire column is from 2 to 5 hPa.
    Type: Application
    Filed: June 12, 2003
    Publication date: February 19, 2004
    Applicant: BASF Akiengesellschaft
    Inventor: Jurgen Schroder
  • Patent number: 6685823
    Abstract: Disclosed herein is a method for inhibiting the premature polymerization of ethylenically unsaturated monomers comprising adding to said monomers an effective amount of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds. Also disclosed is a composition of matter comprising: A) an ethylenically unsaturated monomer and B) an effective inhibiting amount, sufficient to prevent premature polymerization during distillation or purification of said ethylenically unsaturated monomer, of at least one inhibitor selected from the group consisting of C-nitrosoaniline and quinone imine oxime compounds used together with an effective amount of oxygen or air to enhance the inhibiting activity of said inhibitor.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: February 3, 2004
    Assignee: Uniroyal Chemical Company, Inc.
    Inventors: Brigitte Benage, Gerald J. Abruscato, Andrew J. Eisenstein
  • Patent number: 6676808
    Abstract: A method for starting up a distilling column destined to handle an easily polymerizing compound-containing solution characterized by supplying at the start of the operation of the distilling column a polymerization inhibitor to the bottom liquid of the distilling column having a temperature of not higher than 80° C. Further, by supplying a reflux liquid through the top of the distilling column or the middle stage of the column prior to the start of the temperature elevation of the distilling column, thereby preventing the polymerization of the easily polymerizing compound more effectively.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: January 13, 2004
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kei Hamamoto, Yukihiro Matsumoto, Sei Nakahara, Misao Inada