Patents by Inventor Nanako Saigusa
Nanako Saigusa 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: 11078179Abstract: In a method for producing a cyclic ester according to an embodiment of the present invention, a mixture (I) containing an aliphatic polyester, a specific polyalkylene glycol diether, and a sulfonic acid compound as a thermal stabilizer is prepared and heated in predetermined conditions to obtain a mixture (II) in a state of solution. Furthermore, heating of the mixture (II) is continued to distill, together with the polyalkylene glycol diether, a cyclic ester formed by the depolymerization reaction, and thus a distillate (III) is obtained. The cyclic ester is recovered from the distillate (III). At this time, a specific solubilizing agent is added to at least one of the mixture (I) or (II). In this production method, the sulfonic acid compound as the thermal stabilizer is contained in the mixtures (I) and (II) and the distillate (III).Type: GrantFiled: March 7, 2019Date of Patent: August 3, 2021Assignee: KUREHA CORPORATIONInventors: Nanako Saigusa, Takenori Tose, Toshihiko Ono, Yoshinori Suzuki
-
Publication number: 20200392102Abstract: In a method for producing a cyclic ester according to an embodiment of the present invention, a mixture (I) containing an aliphatic polyester, a specific polyalkylene glycol diether, and a sulfonic acid compound as a thermal stabilizer is prepared and heated in predetermined conditions to obtain a mixture (II) in a state of solution. Furthermore, heating of the mixture (II) is continued to distill, together with the polyalkylene glycol diether, a cyclic ester formed by the depolymerization reaction, and thus a distillate (III) is obtained. The cyclic ester is recovered from the distillate (III). At this time, a specific solubilizing agent is added to at least one of the mixture (I) or (II). In this production method, the sulfonic acid compound as the thermal stabilizer is contained in the mixtures (I) and (II) and the distillate (III).Type: ApplicationFiled: March 7, 2019Publication date: December 17, 2020Applicant: Kureha CorporationInventors: Nanako SAIGUSA, Takenori TOSE, Toshihiko ONO, Yoshinori SUZUKI
-
Patent number: 9512100Abstract: A method for producing glycolide (GL) by heating a glycolic acid oligomer (GAO) to depolymerize the GAO. The method for producing GL comprises: a step 1 of heating a mixture containing a GAO having a terminal COOH concentration of 400 eq/t or less and a polar organic solvent to a GAO depolymerization temperature under ambient pressure or reduced pressure; a step 2 of continuing the heating at the temperature for depolymerizing of the GAO and then codistilling out the produced GL and the solvent from the depolymerization reaction system to the outside the reaction system; and a step 3 of obtaining GL from the codistillation product. In the method for producing GL, the GAO is preferably prepared by a GAO production method which comprises a step of condensing glycolic acid (GA) and a dehydration step of continuing the heating together with a polar organic solvent or a depolymerization reaction solution to allow the GA condensation reaction to continue.Type: GrantFiled: March 25, 2014Date of Patent: December 6, 2016Assignee: KUREHA CORPORATIONInventors: Yoshiko Ikeyama, Nanako Saigusa, Kensuke Suzuki
-
Publication number: 20160002196Abstract: A method for producing glycolide (GL) by heating a glycolic acid oligomer (GAO) to depolymerize the GAO. The method for producing GL comprises: a step 1 of heating a mixture containing a GAO having a terminal COOH concentration of 400 eq/t or less and a polar organic solvent to a GAO depolymerization temperature under ambient pressure or reduced pressure; a step 2 of continuing the heating at the temperature for depolymerizing of the GAO and then codistilling out the produced GL and the solvent from the depolymerization reaction system to the outside the reaction system; and a step 3 of obtaining GL from the codistillation product. In the method for producing GL, the GAO is preferably prepared by a GAO production method which comprises a step of condensing glycolic acid (GA) and a dehydration step of continuing the heating together with a polar organic solvent or a depolymerization reaction solution to allow the GA condensation reaction to continue.Type: ApplicationFiled: March 25, 2014Publication date: January 7, 2016Applicant: Kureha CorporationInventors: Yoshiko IKEYAMA, Nanako SAIGUSA, Kensuke SUZUKI
-
Publication number: 20150072903Abstract: A dispersion liquid for supporting oil drilling, including: an aqueous medium and a particulate solid polyglycolic acid resin dispersed in the aqueous medium; wherein the particulate polyglycolic acid resin has a weight-average molecular weight of at least 70,000 and at most 500,000, and exhibits weight retentivities in water at 80° C. of at least 85% after 12 hours, at most 80% after 72 hours, and at most 45% after 168 hours. The particulate solid polyglycolic acid resin included in the above-mentioned dispersion liquid for supporting oil drilling, functions as a fluidity control material exhibiting ideal degradation charateristics in the drilling operation for expansion of oil production capacity, demanded for suppressing the liquid permeability in the early stage and recovery of the liquid permeability after completion of the operation of the formation around the oil well.Type: ApplicationFiled: November 12, 2014Publication date: March 12, 2015Inventors: Shunsuke ABE, Nanako SAIGUSA, Masahiro YAMAZAKI, Hiroyuki SATO
-
Publication number: 20140017495Abstract: The invention provides biodegradable aliphatic polyester particles having the following physical properties: (A) the average particle diameter thereof is 5 to 500 ?m; and (B) the fracture stress of a columnar tablet obtained by molding the particles in a cylindrical mold by applying a load of 4 kgf/cm2 for 1 hour at a temperature of 40° C. is at most 500 gf/cm2, and preferably also having the following property: (C) the fracture stress of a columnar tablet obtained by molding the particles in a cylindrical mold by applying a load of 4 kgf/cm2 for 1 hour at a temperature of [the glass transition temperature (Tg) of a biodegradable aliphatic polyester +10° C.Type: ApplicationFiled: March 21, 2012Publication date: January 16, 2014Applicant: KUREHA CORPORATIONInventors: Masahiro Yamazaki, Kotaku Saigusa, Shunsuke Abe, Nanako Saigusa, Hiroyuki Sato
-
Publication number: 20130252854Abstract: A dispersion liquid for supporting oil drilling, including: an aqueous medium and a particulate solid polyglycolic acid resin dispersed in the aqueous medium; wherein the particulate polyglycolic acid resin has a weight-average molecular weight of at least 70,000 and at most 500,000, and exhibits weight retentivities in water at 80° C. of at least 85% after 12 hours, at most 80% after 72 hours, and at most 45% after 168 hours. The particulate solid polyglycolic acid resin included in the above-mentioned dispersion liquid for supporting oil drilling, functions as a fluidity control material exhibiting ideal degradation characteristics in the drilling operation for expansion of oil production capacity, demanded for suppressing the liquid permeability in the early stage and recovery of the liquid permeability after completion of the operation of the formation around the oil well.Type: ApplicationFiled: October 14, 2011Publication date: September 26, 2013Inventors: Shunsuke Abe, Nanako Saigusa, Masahiro Yamazaki, Hiroyuki Sato