Patents by Inventor Masanobu Ajioka
Masanobu Ajioka 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).
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Patent number: 5424477Abstract: .alpha.-L-Aspartyl-L-phenylalanine methyl ester (.alpha.-APM) is prepared by catalytic hydrogenation of N-benzyloxycarbonyl-.alpha.-L-aspartyl-L-phenylalanine methyl ester (Z-.alpha.-APM). The catalytic hydrogenation is conducted in an aqueous suspension containing the Z-.alpha.-APM in the form of particles whose average particle size is not greater than 800 .mu.m. The starting Z-.alpha.-APM may contain up to 30 wt. % of its .beta.-isomer provided that the process additionally includes recrystallization of the .alpha.-APM, collection of the .alpha.-APM by filtration and recycling of the filtrate for use in the aqueous suspension of Z-.alpha.-APM.Type: GrantFiled: September 30, 1993Date of Patent: June 13, 1995Assignee: Mitsui Toatsu Chemicals IncorporatedInventors: Chojiro Higuchi, Ikumi Kitada, Akinori Nagatomo, Katashi Enomoto, Masanobu Ajioka, Akihiro Yamaguchi
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Patent number: 5409751Abstract: A degradable container which is excellent in transparency and impact strength and can be decomposed into nontoxic water and carbon dioxide in the natural environment within a relatively short period can be obtained by using the process for molding a container of an arbitrary shape from a thermoplastic composition having polylactic acid of lactic acids or a copolymer of lactic acids and other hydroxycarboxylic acids as a main component, preforming the composition and thereafter molding the container in a temperature range from Tg to Tg+60.degree. C. on the basis of the glass transition temperature Tg of the thermoplastic polymer composition and under the condition of a draw ratio of 6 times or less.Type: GrantFiled: March 17, 1993Date of Patent: April 25, 1995Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Kazuhiko Suzuki, Takayuki Watanabe, Yasuhiro Kitahara, Masanobu Ajioka
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Patent number: 5401796Abstract: A preparation process of aliphatic polyester having a weight average molecular weight of 15,000 or more by conducting a direct polycondensation reaction of an aliphatic polyhydric alcohol or a mixed aliphatic polyhydric alcohol and an aliphatic polybasic acid or a mixed aliphatic polybasic acid, or additionally a hydroxycarboxylic acid or a mixed hydroxycarboxylic acid or an oligomer of the hydroxycarboxylic acid in a reaction mixture containing an organic solvent.The aliphatic polyester thus obtained contains an extremely small amount of impurities, has low color and can exhibit satisfactory strength in the form of films, filaments and other shaped articles.Type: GrantFiled: March 29, 1994Date of Patent: March 28, 1995Assignee: Mitsui Toatsu Chemicals, Inc.Inventors: Takeshi Kashima, Taiji Kameoka, Chojiro Higuchi, Masanobu Ajioka, Akihiro Yamaguchi
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Patent number: 5387665Abstract: A resin for electrophotographic toner comprising a degradable polyester resin which is an amorphous poly (.alpha.-hydroxycarboxylic acid) prepared by direct dehydration-polycondensation of an .alpha.-hydroxycarboxylic acid and having, preferably, a number-average molecular weight ranging from 2000 to 7000. A further resin for electrophotographic toner comprising a degradable polyester resin which may be prepared by reacting an amorphous or semicrystalline poly (.alpha.-hydroxycarboxylic acid), having a number-average molecular weight ranging from 1000 to 7000 or 2000 to 7000 and prepared by direct dehydration-polycondensation of an .alpha.-hydroxycarboxylic acid, with a polyol having at least three hydroxyl groups or a polycarboxylic acid having at least three carboxyl groups in the molecule and, in case of the reaction product with the polyol can further be reacted with a diisocyanate to give an urethane-modified polyester. These polyesters can likewise be used as resins for toner.Type: GrantFiled: February 25, 1994Date of Patent: February 7, 1995Assignee: Mitsui Toatsu Chemicals, Inc.Inventors: Akira Misawa, Masanobu Ajioka
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Patent number: 5374765Abstract: Disclosed is a method for extracting an amino acid ester from a hydrous solution which comprises adding thereto a water-insoluble organic solvent and then an amount of a base effective to liberate only a portion of the amino acid ester in free base form, and transferring the thus liberated amino acid ester in the free base form into the organic layer, and repeating the neutralization-extraction steps until all of the amino acid ester has been extracted.Type: GrantFiled: January 19, 1993Date of Patent: December 20, 1994Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Tomoko Kamashita, Hiroyuki Yamashita, Teruyuki Nagata, Masanobu Ajioka
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Patent number: 5310865Abstract: A process for preparing polyhydroxycarboxylic acid by conducting a dehydration condensation of a hydroxycarboxylic acid or an oligomer thereof in a reaction mixture containing an organic solvent substantially in the absence of water and the polyhydroxycarboxylic acid thus obtained. The process provides polyhydroxycarboxylic acid having excellent properties and processability.Type: GrantFiled: December 18, 1992Date of Patent: May 10, 1994Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Katashi Enomoto, Masanobu Ajioka, Akihiro Yamaguchi
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Patent number: 5302743Abstract: Disclosed is an improved process for the preparation of an N-protected .alpha.-L-aspartyl-L-phenylalanine methyl ester from an N-protected L-aspartic anhydride and L-phenylalanine methyl ester, the improvement which comprises employing the L-phenylalanine methyl ester in the form of a mineral acid salt thereof and conducting the reaction either (a) in an organic solvent and in the presence of a salt of an organic carboxylic acid, or (b) in an organic solvent comprising an organic carboxylic acid and in the presence of at least one member of the group consisting of an alkali metal or an alkaline earth metal inorganic base, an ammonium alkali metal or alkaline earth metal salt of an organic carboxylic acid and ammonium carbonate. The starting N-protected aspartic anhydride, e.g., N-benzyloxycarbonyl-L-aspartic anhydride, can be produced by the reaction of N-protected aspartic acid with phosgene.Type: GrantFiled: January 21, 1992Date of Patent: April 12, 1994Assignee: Mitsui Toatsu Chemicals, Inc.Inventors: Toshio Katoh, Chojiro Higuchi, Takeshi Oura, Masanobu Ajioka, Akihiro Yamaguchi
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Patent number: 5294469Abstract: A thermoplastic polymer composition primarily comprising polylactic acid or a copolymer of lactic acids and the other hydroxycarboxylic acids than lactic acids, industrial fabrics which can be degraded into nontoxic water and carbon dioxide within a relatively short period under the natural environment, and flexible containers, water shielding sheets and resin coated-cloth ventilation tubes which are prepared from the industrial fabrics.Type: GrantFiled: June 16, 1993Date of Patent: March 15, 1994Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Kazuhika Suzuki, Takayuki Watanabe, Yasuhiro Kitahara, Masanobu Ajioka
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Patent number: 5283357Abstract: A method for separating .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM) from a solution containing .alpha.-APM and impurities associated with the production thereof which comprises adding a mineral acid or an organic sulfonic acid to the solution in an organic carboxylic acid or in a solvent containing an organic carboxylic acid, and isolating the pure salt of .alpha.-APM which precipitates therefrom.Type: GrantFiled: April 23, 1991Date of Patent: February 1, 1994Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Toshio Katoh, Chojiro Higuchi, Takeshi Oura, Masanobu Ajioka, Akihiro Yamaguchi
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Patent number: 5254323Abstract: A gaseous mixture containing chlorine, carbon dioxide and non-condensable gas is compressed and cooled to separate it into a residual gas formed principally of a major portion of the non-condensable gas and a condensate formed primarily of chlorine. The condensate is fed to a stripping column to desorb carbon dioxide and a minor portion of the non-condensable gas dissolved in the condensate. The stripped gas formed primarily of chlorine and carbon dioxide may be treated further. Namely, the stripped gas is mixed with the residual gas. At least a portion of the mixed gas is fed into an absorption column, whereby a major portion of remaining chlorine is absorbed to lower the chlorine content Removal of chlorine from such a gaseous mixture or an off-gas from the above process can be achieved by washing it with an aqueous solution or suspension containing an alkali metal sulfite and/or an alkaline earth metal sulfite while controlling the pH of the solution or suspension within a range of 1.9-6.3.Type: GrantFiled: August 3, 1992Date of Patent: October 19, 1993Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Hiroyuki Itoh, Yoshitsugu Kono, Isao Kikuchi, Shinji Takenaka, Masanobu Ajioka, Mitsuo Kudoh
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Patent number: 5206413Abstract: A method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM), substantially free from acid ion contamination, is disclosed which comprises the steps of contacting a solution of a mineral acid salt or an organic sulfonic acid salt of .alpha.-APM in an aqueous solvent with an anion exchange resin in free base form, separating the resin from the thus-produced solution of .alpha.-APM; and isolating the .alpha.-APM therefrom, preferably with regeneration and recycling the resin.Type: GrantFiled: June 14, 1990Date of Patent: April 27, 1993Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Masanobu Ajioka, Takeshi Oura, Chojiro Higuchi, Toshio Katoh, Akihiro Yamaguchi
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Patent number: 5147624Abstract: Chlorine can be efficiently produced at a low temperature and with a high hourly space velocity by oxidizing hydrogen chloride with an oxygen-containing gas in the presence of a catalyst obtained by calcining a compound, which has in turn been obtained by reacting chromium nitrate, chromium chloride, the chromium salt of an organic acid or the like with ammonia, or by calcining a mixture of the compound and a silicon compound, preferably, at a temperature lower than 800.degree. C.Type: GrantFiled: September 16, 1991Date of Patent: September 15, 1992Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Tadamitsu Kiyoura, Masanobu Ajioka, Naoshi Fujimoto, Toshihide Suzuki, Yasuo Kogure, Tokio Nagayama, Kazuo Kanaya
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Patent number: 5112580Abstract: Chlorine is produced by reacting hydrogen chloride and oxygen in the presence of a chromium oxide catalyst in a reactor whose catalyst-contacting part is lined with one of lining materials represented by the following general formula (I):M.sub.a X.sub.b (I)wherein M can be boron, aluminum, silicon, titanium, zirconium or chromium, X denotes oxygen, nitrogen or carbon, a is an integer of 1-2 and b stands for an integer of 1-3 or with a mixture of at least two of the lining materials. The above process and reactor are effective in maintaining the activity of the catalyst.Type: GrantFiled: May 21, 1990Date of Patent: May 12, 1992Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Masanobu Ajioka, Shinji Takenaka, Hiroyuki Itoh, Masafumi Kataita, Yoshitsugu Kohno
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Patent number: 5113009Abstract: A cyclical process for producing and isolating a mineral acid salt of an amino acid methyl ester in high purity and yield from the reaction solution produced by esterifying an amino acid with methanol in methanol in the presence of a mineral acid, by cooling the resulting reaction solution to precipitate crystals of the mineral acid salt; filtering the crystals;drying the isolated wet crystals or washing with another organic solvent; and recycling the filtrate for reuse in the esterification reaction.Type: GrantFiled: December 26, 1989Date of Patent: May 12, 1992Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Masanobu Ajioka, Chojiro Higuchi, Takeshi Oura, Toshio Katoh, Akihiro Yamaguchi
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Patent number: 5112593Abstract: Chlorine is produced by reacting hydrogen chloride and oxygen in the presence of a catalyst composed of a chromium oxide as a principal component. The reaction is carried out in a fluidized bed reactor equipped at vertical intervals not greater than 100 cm with a plurality of perforated horizontal plates having a perforation rate of 10-60% in a reaction zone in which the catalyst is fluidized in operation. The reaction zone is above a gas diffuser plate.Type: GrantFiled: October 9, 1990Date of Patent: May 12, 1992Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Hiroyuki Itoh, Yoshitsugu Kono, Isao Kikuchi, Shinji Takenaka, Masanobu Ajioka
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Patent number: 5034209Abstract: Chlorine is produced by reacting hydrogen chloride and oxygen in the presence of a chromium oxide catalyst in a reactor whose catalyst-contacting part is lined with one of lining materials represented by the following general formula(I):M.sub.a X.sub.b (I)wherein M means boron, aluminum, silicon, titanium, zirconium or chromium, X denotes oxygen, nitrogen or carbon, a is an integer of 1-2 and b stands for an integer of 1-3 or with a mixture of at least two of the lining materials. The above process and reactor are effective in maintaining the activity of the catalyst.Type: GrantFiled: April 13, 1990Date of Patent: July 23, 1991Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Masanobu Ajioka, Shinji Takenaka, Hiroyuki Itoh, Masafumi Kataita, Yoshitsugu Kohno
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Patent number: 5000006Abstract: A gaseous mixture containing chlorine, carbon dioxide and non-condensable gas is compressed and cooled to separate it into a residual gas formed principally of a major portion of the non-condensable gas and a condensate formed primarily of chlorine. The condensate is fed to a stripping column to desorb carbon dioxide and a minor portion of the non-condensable gas dissolved in the condensate. The stripped gas formed primarily of chlorine and carbon dioxide may be treated further. Namely, the stripped gas is mixed with the residual gas. At least a portion of the mixed gas is fed into an absorption column, whereby a major portion of remaining chlorine is absorbed to lower the chlorine content. Removal of chlorine from such a gaseous mixture or an off-gas from the above process can be achieved by washing it with an aqueous solution or suspension containing an alkali metal sulfite and/or an alkaline earth metal sulfite while controlling the pH of the solution or suspension within a range of 1.9-6.3.Type: GrantFiled: February 16, 1989Date of Patent: March 19, 1991Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Hiroyuki Itoh, Yoshitsugu Kono, Isao Kikuchi, Shinji Takenaka, Masanobu Ajioka, Mitsuo Kudoh
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Patent number: 4956169Abstract: Chlorine is produced by reacting hydrogen chloride and oxygen in the presence of a chromium oxide catalyst in a reactor whose catalyst-contacting part is lined with one of lining materials represented by the following general formula (I):M.sub.a X.sub.b (I)wherein M means boron, aluminum, silicon, titanium, zirconium or chromium, X denotes oxygen, nitrogen or carbon, a is an integer of 1-2 and b stands for an integer of 1-3 or with a mixture of at least two of the lining materials. The above process and reactor are effective in maintaining the activity of the catalyst.Type: GrantFiled: March 18, 1988Date of Patent: September 11, 1990Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Masanobu Ajioka, Shinji Takenaka, Hiroyuki Itoh, Masafumi Kataita, Yoshitsugu Kohno
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Patent number: 4922005Abstract: Hexamethylene diisocyanate (HDI) is prepared by introducing a hexamethylenediamine (HDA) solution and an equivalent amount or more of hydrogen chloride gas simultaneously into a turbulent zone in the vicinity of an agitating blade in an inert organic solvent held under agitation within a tank-shaped reactor and allowing them to undergo a successive salt-forming reaction so as to obtain a high-concentration slurry of hexamethylenediamine hydrochloride (HDA.multidot.HCl) and then reacting the slurry with phosgene. The phosgenation is effected by charging an HDA.multidot.HCl slurry of a high concentration, such as that obtained by the above process, into a tank-shaped reactor held under a pressure above the atmosphere pressure but below 5 kg/cm.sup.2 G and controlling the amount of phosgene, which is to be blown into the reactor, at a level 1-18 molar times per hour the total amount of HDA.multidot.HCl and HDI in the reaction mixture.Type: GrantFiled: November 13, 1985Date of Patent: May 1, 1990Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Masanobu Ajioka, Makoto Aiga, Masafumi Kataita, Akihiro Tamaki
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Patent number: 4897506Abstract: A method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester having improved solubilization by the isolation thereof from an aqueous medium containing at least one additive selected from the group consisting of sodium alginate, sodium salt of carboxymethylcellulose, sodium starch glycolate and sodium polyacrylate.Type: GrantFiled: October 12, 1988Date of Patent: January 30, 1990Assignee: Mitsui Toatsu Chemicals, IncorporatedInventors: Ryuichi Mita, Takeshi Oura, Toshio Katoh, Chojiro Higuchi, Akihiro Yamaguchi, Masanobu Ajioka