Patents by Inventor Sei Nakahara

Sei Nakahara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • 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
  • 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
  • Patent number: 6664418
    Abstract: A method for inhibiting polymerization during transportation, storage and/or production of (meth)acrylic acid or an ester thereof includes adding an N-oxyl compound and water to a vinyl compound; or dissolving an N-oxyl compound in water and adding the solution to a vinyl compound in a process of recovering, purifying, and/or synthesizing of the vinyl compound. The method can effectively inhibit polymerization of the vinyl compound.
    Type: Grant
    Filed: July 27, 1999
    Date of Patent: December 16, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Kazuo Ohkouchi, Masahiro Uemura, Sei Nakahara, Masatoshi Ueoka
  • Patent number: 6660881
    Abstract: The present invention provides a process for producing a (meth)acrylic ester which enables to obtain a (meth)acrylic ester in an excellent reaction yield. The process for producing a (meth)acrylic ester uses an alcohol and an acid as raw materials and an ion-exchange resin as a catalyst, and the process is characterized by comprising a dehydration step and an esterification step, wherein the esterification reaction step follows the dehydration step in which water impregnated in the ion-exchange resin is removed by using as a dehydrating solvent at least one member selected from the group consisting of the alcohol, the acid, and the resulting ester.
    Type: Grant
    Filed: August 12, 2001
    Date of Patent: December 9, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Hajime Matsumoto, Tetsuya Kajihara, Yasuhiro Shingai, Masatoshi Ueoka, Yukihiro Yoneda, Masahiro Uemura, Sei Nakahara, Fumio Munechika
  • Patent number: 6657079
    Abstract: A method for mixing a plurality of gases including forming a helical flow within a mixing vessel thereby allowing simplification of construction, avoiding pressure drop to the fullest possible extent, and expediting the mixture lest the volume of a gas within the explosion limits should increase, and an apparatus to be used for the method.
    Type: Grant
    Filed: August 17, 2000
    Date of Patent: December 2, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Tetsuji Mitsumoto, Tatsuaki Yoshimura, Takeshi Nishimura, Sei Nakahara
  • Patent number: 6651731
    Abstract: For a heat exchanger using a heating medium for the purpose of heating a fluid to be handled during a steady state, this invention provides a method for using relevant devices which enables the heat exchanger to be operated safely and infallibly without suffering the raw material or the reaction product to polymerize in the reactor or the pipes during an unsteady state, suffering the reactor or the pipes to sustain a fracture owing to a rise in the internal pressure of the vessel, and suffering the apparatus for production to sustain serious damage. This invention pertains, mainly in a heat exchanger admitting a heating medium and using it for the purpose of heating a fluid to be handled, to a method for using relevant devices during the unsteady state, characterized by introducing a cooling medium in the place of the heating medium mentioned above.
    Type: Grant
    Filed: February 1, 2002
    Date of Patent: November 25, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Takeshi Nishimura, Yukihiro Matsumoto, Sei Nakahara, Motomi Nakamura
  • Patent number: 6649028
    Abstract: The present invention provides a column treating method by use of a distillation column and so on, which method enables to effectively remove solid impurities such as precipitates and polymers contained or produced in a treating fluid, and to thereby stably operate the column treatment. Solid impurities in a treating fluid can be removed by carrying out: step (a) of drawing out the treating fluid from a drawing out outlet (16) at the column bottom of the treatment column (10) outside the treatment column (10), step (b) of removing solid impurities from the treating fluid, drawn out in step (a), by a strainer (40), and step (c) of returning the treating fluid, from which the solid impurities are removed in step (b), to a returning inlet (18) of the treatment column, with advancing physical and/or chemical treatment of the treating fluid in the treatment column (10).
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: November 18, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Sei Nakahara, Masatoshi Ueoka, Naoto Kasaya
  • Patent number: 6649787
    Abstract: An improvement is provided in a method for preparing an (meth)acrylic acid ester comprising an esterification step for forming the (meth)acrylic acid ester by esterification reaction between (meth)acrylic acid and the corresponding aliphatic alcohol having 1 to 4 carbon atoms in the presence of an acidic catalyst, and a separation-purification step comprising an acid-separating column, a low boiling matter-separating column and a rectification column for separating and purifying the (meth)acrylic acid ester from the (meth)acrylic acid ester-containing mixture obtained in the esterification step. This improvement lies in that by circulating the bottom residue of the rectification column into the esterification step and/or the separation-purification step, the remaining polymerization inhibitor in the bottom residue is effectively reused and the remaining (meth)acrylic acid ester in the bottom residue is efficiently recovered.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: November 18, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Sei Nakahara, Masatoshi Ueoka
  • Patent number: 6642414
    Abstract: A method for producing (meth)acrylic acid of high purity by repressing formation of a polymer possibly generated during the course of production is disclosed. The production is accomplished by returning the waste liquid generated at the step of the addition of aldehyde treating agents (d) to the step of the absorption (b) and/or the step of separation (c).
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: November 4, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Tetsuji Mitsumoto, Yukihiro Matsumoto, Sei Nakahara, Tatsuaki Yoshimura
  • Publication number: 20030181621
    Abstract: A method for producing polyacrylic acid includes a combined process of an acrylic acid production process and a polyacrylic acid production process. The acrylic acid production process includes the steps of catalytically oxidizing propylene and/or propane in a gaseous phase to generate reaction product, absorbing the reaction product in a solvent, and purifying acrylic acid from an acrylic acid aqueous solution containing the solvent by purification. The polyacrylic acid production process includes the step of utilizing heat medium recovered in the acrylic acid production process to purify polyacrylic acid from the acrylic acid aqueous solution or from acrylic acid.
    Type: Application
    Filed: February 28, 2003
    Publication date: September 25, 2003
    Inventors: Yukihiro Matsumoto, Sei Nakahara, Kunihiko Ishizaki
  • Patent number: 6613196
    Abstract: A method for stopping a purifying column handling an easily polymerizing compound-containing solution is disclosed, which method is characterized by lowering the inner oxygen concentration of the column below the limit of oxygen concentration by supplying an inert gas to the column while the concentration of the gas of easily polymerizing compound is in the range of 100% to the lower limit of the flammable range in volume % of the purifying column or by further supplying a reflux liquid thereby cooling the interior of the column at a rate in the range of 0.01-10° C./min. This invention enjoys exceptionally high economic value in respect that it is capable of preventing the easily polymerizing compound from the occurrence of polymerization in the purifying column, precluding the interior of the purifying column from being clogged by adhesion of a polymer, and moreover avoiding the possibility of explosion.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: September 2, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kei Hamamoto, Yukihiro Matsumoto, Sei Nakahara, Misao Inada
  • Publication number: 20030143143
    Abstract: Disclosed is a process for treating wastes discharged from an acrylic acid production process and a consecutive polyacrylic acid production process in which at least one waste selected from the group consisting of waste oil, waste water, and waste gas from said acrylic acid production process, and waste water and/or waste gas from said polyacrylic acid production process are combusted simultaneously.
    Type: Application
    Filed: January 29, 2003
    Publication date: July 31, 2003
    Inventors: Yukihiro Matsumoto, Sei Nakahara, Kunihiko Ishizaki
  • Patent number: 6599397
    Abstract: This method of preventing polymerization of methacrylic acid inn the process of its production is characterized by comprising using, in a refining column, a combination of N-nitrosophenylhydroxylamine or salt thereof with an N-oxyl compound, an N-hydroxy-,2,2,6,6-tetramethylpiperidine compound and a 2,2,6,6-tetramethylpiperidine compound. In this method, N-nitrosophenylhydroxylamine or a salt thereof rises inside a refining column under splitting part thereof to effectively inhibit polymerization of (meth)acrylic acid or the like. The above polymerization in both vapor and liquid phases can be inhibited more effectively by the combined use of the compounds mentioned above.
    Type: Grant
    Filed: June 6, 2001
    Date of Patent: July 29, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Tomohiro Nakae, Kazuo Okochi, Masahiro Uemura, Sei Nakahara
  • Patent number: 6588450
    Abstract: This invention relates to a storage tank for a viscous oil containing easily polymerizable compounds. The storage tank of the present invention for storing viscous oil containing easily polymerizable compounds comprises a bottom plate, a side wall, a draw-off pipe and an inlet pipe. The bottom plate slopes downwardly toward the draw-off pipe, and an angle of downward inclination of the bottom plate is a gradient of at least 1/200. It becomes possible because of the storage tank to effectively prevent polymerization of easily polymerizable compounds contained in waste oil within the storage tank, and clogging of a pipe is suppressed considerably.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: July 8, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Yuichi Ijiri, Yukihiro Matsumoto, Sei Nakahara, Fumio Munechika
  • Publication number: 20030111216
    Abstract: In an apparatus provided with a plate type heat exchanger as a heater and/or a cooler and operated to treat a gas containing an easily blocking substance, a method for preventing the plate type heat exchanger from being blocked is disclosed which is characterized by i) setting the width of a flow path on a plate of the plate type heat exchanger in the apparatus in a range of 6-25 mm and ii) setting the average flow rate of the gas passing the plate type heat exchanger in the apparatus per unit cross-sectional area of the flow path on the plate in the range of 3-15 m/s. In the exchange of heat of an easily blocking substance by the use of a plate type heat exchanger, a method for preventing the plate type heat exchanger from blockage is disclosed which has the plate type heat exchanger provided in the port for introducing a gas containing an easily blocking substance with a gas dispersion plate.
    Type: Application
    Filed: January 31, 2003
    Publication date: June 19, 2003
    Inventors: Harunori Hirao, Yukihiro Matsumoto, Sei Nakahara, Osamu Dodo, Tetsuji Mitsumoto, Takeshi Nishimura, Kazuhiko Sakamoto, Hiroo Iwato
  • Patent number: 6566551
    Abstract: For use in a process for the production of (meth)acrylic acid comprising at least a step for the reaction of (meth)acrylic acid by catalytic gas phase oxidation and a step for the absorption thereof, a method for preventing an effluent gas pipe from blocking is disclosed, which method is characterized by causing part or the whole of the gas discharged from the step for absorption, while being circulated via the effluent gas pipe to the step for the reaction or being discarded, to be subjected to temperature elevation and application of pressure and/or mist separation. Particularly by setting the temperature of the waste gas from the absorption column at a level in the range of 30-70° C.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: May 20, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Takeshi Nishimura, Yukihiro Matsumoto, Sei Nakahara, Misao Inada, Harunori Hirao, Mamoru Takamura
  • Publication number: 20030089491
    Abstract: A shell-and-tube type heat exchanger of the smallest possible length necessary for heat exchange is disclosed which is capable of obtaining uniform distribution of flow of a shell side fluid and substantially eliminating the structural restriction imposed on the shell side. This shell-and-tube type heat exchanger is provided with one annular conduit furnished with not less than two partitions concurrently serving as an expansion joint for introducing and discharging a shell side fluid and allowing the flow path for said shell side fluid to be separated into an introducing part and a discharging part and which comprises a place having no array of heat-transfer tubes in the flow path for said shell side fluid. It prevents the equipment from necessitating an unnecessary enlargement due to the structural restriction on the shell side and enables the shell side fluid to produce a uniform flow.
    Type: Application
    Filed: September 25, 2002
    Publication date: May 15, 2003
    Inventors: Tetsuji Mitsumoto, Takeshi Nishimura, Sei Nakahara, Osamu Dodo
  • Patent number: 6540881
    Abstract: This invention relates to a method for preventing (meth)acrylic acid from polymerizing during the course of distillation. The method provides for refining (meth)acrylic acid by a procedure including the steps of feeding a mixed gas obtained by catalytic gas phase oxidation of propylene and/or acrolein with a molecular oxygen-containing gas or a mixed gas obtained by catalytic gas phase oxidation of at least one compound of isobutylene, t-butyl alcohol, or methacrolein with a molecular oxygen-containing gas, to a (meth)acrylic acid collection column, collecting a (meth)acrylic acid-containing solution from the mixed gas, and feeding the (meth)acrylic acid-containing solution to a distillation column while maintaining the total concentration of aldehydes of 2-4 carbon atoms and acetone in the solution at a level of not more than 2000 ppm based on the amount of (meth)acrylic acid.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: April 1, 2003
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Kouji Ueno, Sei Nakahara, Masatoshi Ueoka
  • Publication number: 20030006026
    Abstract: A shell-and tube reactor including at least one reaction tube with a measuring means, substantially same solid particles being filled in the reaction tubes with or without the measuring means, a length of the filled solid particle layer, and a pressure drop thereof while passing a gas through the reaction tube, per each reaction tube, being substantially the same, respectively. By measuring the temperature of the catalyst particle layer, such a temperature as a representative can be gasped.
    Type: Application
    Filed: June 5, 2002
    Publication date: January 9, 2003
    Inventors: Yukihiro Matsumoto, Takeshi Nishimura, Sei Nakahara, Naoto Kasaya
  • Publication number: 20020189927
    Abstract: The present invention provides a column treating method by use of a distillation column and so on, which method enables to effectively remove solid impurities such as precipitates and polymers contained or produced in a treating fluid, and to thereby stably operate the column treatment. Solid impurities in a treating fluid can be removed by carrying out: step (a) of drawing out the treating fluid from a drawing out outlet (16) at the column bottom of the treatment column (10) outside the treatment column (10), step (b) of removing solid impurities from the treating fluid, drawn out in step (a), by a strainer (40), and step (c) of returning the treating fluid, from which the solid impurities are removed in step (b), to a returning inlet (18) of the treatment column, with advancing physical and/or chemical treatment of the treating fluid in the treatment column (10).
    Type: Application
    Filed: August 22, 2002
    Publication date: December 19, 2002
    Applicant: Nippon Shokubai Co., Ltd.
    Inventors: Kazuhiko Sakamoto, Sei Nakahara, Masatoshi Ueoka, Naoto Kasaya