Patents by Inventor Yataro Ichikawa

Yataro Ichikawa 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: 4082804
    Abstract: A process for preparing 2-amino-1-butanol by reacting L-tartarate of 2-amino-1-butanol with an aqueous slurry alkaline earth metal compound in such a way that some L-tartarate of 2-amino-1-butanol remains in the reaction system throughout the entire time of reaction to produce a precipitate of L-tartarate of the alkaline earth metal which comprises crystals which are sufficiently large so that they have excellent filterability and give a high yield of 2-amino-1-butanol. Highly purified 2-amino-1-butanol can be obtained by subjecting the thus obtained filtrate to rectification.
    Type: Grant
    Filed: October 28, 1976
    Date of Patent: April 4, 1978
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Toru Sawaki, Yuitsu Honda
  • Patent number: 3989706
    Abstract: A process for the preparation of pyridines, which comprises contacting in the vapor phase saturated or unsaturated hydrocarbon of more than one carbon atom, ammonia, and molecular oxygen, with the catalyst composed of solid acid containing at least tellurium, said solid acid containing the acid of which acid strength (Ho) is not weaker than 4.8.
    Type: Grant
    Filed: January 2, 1974
    Date of Patent: November 2, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Yuitsu Honda, Kazuhiko Soma, Nobuo Suzuki, Teizo Yamaji
  • Patent number: 3983159
    Abstract: The oxidative coupling of benzenecarboxylic acid esters to form the corresponding biphenylpolycarboxylic acid esters, comprising contacting a benzenecarboxylic acid ester having at least one hydrogen atom bonded to the nuclear carbon atom of the benzene ring, such as methyl benzeate, with molecular oxygen in a liquid phase using a catalyst comprising at least one compound selected from organic carboxylates of palladium, such as palladium acetate and .beta.-dikete complexes of palladium, such as acetylacetone-palladium complex. Use of at least one zirconium compound, such as zirconium oxystearate in conjunction with the catalyst gives rise to an increased catalytic activity.
    Type: Grant
    Filed: August 16, 1974
    Date of Patent: September 28, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Teizo Yamaji
  • Patent number: 3978092
    Abstract: An unsaturated carbonyl compound, for example, one expressed by the following formula ##EQU1## is prepared by maintaining at an elevated temperature an allyl acetal of an .alpha.,.beta.-unsaturated aldehyde, for example, one expressed by the following formula ##EQU2## or a novel dienyl ether derived from it, for example, one expressed by the following formula ##EQU3## The allyl acetal can be derived, for example, from .beta.-methylcrotonaldehyde having 5 carbon atoms and prenyl alcohol having 5 carbon atoms. It is possible therefore to introduce an allyl residue containing at least 3 carbon atoms into the carbon atoms at the .gamma.-position to the carbonyl group of an .alpha., .beta.-unsaturated aldehyde containing at least 5 carbon atoms by a reaction consisting of the reduced number of steps. Moreover, the unsaturated aldehyde having the increased number of carbon atoms can be formed at a high yield by a relatively simple reaction.
    Type: Grant
    Filed: May 6, 1974
    Date of Patent: August 31, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Mamoru Yamamoto
  • Patent number: 3975441
    Abstract: A process for recovering purified 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadiene-1-one by distilling crude 4-hydroxy-,2,4,6-trimethyl-2,5-cyclohexadien-1-one. Preferably, the distillation is performed at a temperature of 40.degree. to 250.degree.C. using crude 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadien-1-one having a pH of 4 to 11.5. Thus, 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadien-1-one of high purity and reduced coloration can be recovered at a high recovery ratio.
    Type: Grant
    Filed: April 29, 1974
    Date of Patent: August 17, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Yoshiyuki Yamanaka, Nobuo Suzuki, Hideki Tsuruta
  • Patent number: 3968172
    Abstract: A process for the preparation of 2,4,6-trimethylphenol by reacting a phenol of the formula (1) below, ##SPC1##In which R.sub.1 and R.sub.2 each stands for hydrogen atom or methyl groupWith methanol at vapor phase, in the presence of a magnesium oxide-containing catalyst, to methylate the former, the characteristic features residing in that the reaction is performed at the temperatures ranging from 400.degree. to 500.degree.C., and the gaseous mixture composed essentially of the phenol and methanol is contacted with the catalyst at a flow rate not higher than 0.4/hour (sum weight in grams of the phenol and methanol/catalyst's weight in grams/hour).
    Type: Grant
    Filed: October 2, 1973
    Date of Patent: July 6, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Yoshiyuki Yamanaka, Tatuyuki Naruchi, Osamu Kobayashi, Koichiro Sakota
  • Patent number: 3966818
    Abstract: A process for preparing 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadiene-1-one comprising reacting 2,4,6-trimethyl phenol with molecular oxygen or a molecular oxygen-containing gas. The product (also called mesitylquinol) is an intermediate useful as a raw material for the synthesis of a variety of industrial chemicals such as a drugs, dyestuffs, and pigments.
    Type: Grant
    Filed: March 19, 1973
    Date of Patent: June 29, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Yoshiyuki Yamanaka, Hideki Tsuruta
  • Patent number: 3963787
    Abstract: The oxidative coupling of benzene or benzene derivatives to form the corresponding diphenyls, comprising contacting benzene or a benzene derivative, such as toluene, with molecular oxygen using as a catalyst organic carboxylates of palladium such as palladium acetate. Use of at least one zirconium compound such as zirconium oxystearate in conjunction with the catalyst gives rise to an increased catalytic activity. The diphenyls are intermediates for production of dyestuffs, pharmaceuticals and other chemicals, and also find application in the preparation of high-molecular-weight polyesters and polyamides.
    Type: Grant
    Filed: January 24, 1973
    Date of Patent: June 15, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Teizo Yamaji
  • Patent number: 3957887
    Abstract: This invention is directed to a process for preparing trimethylhydroquinone (TMHQ) by heating 4-hydroxy-2,4,6-trimethyl-2,5-cyclohexadiene-1-one (HTCD) in a nonacidic liquid medium consisting of either methanol or an aqueous medium, preferably in the presence of a basic substance, at a temperature of at least 100.degree.C., and preferably 150.degree.-300.degree.C.Thus, according to this invention, TMHQ of high purity and small coloration can be prepared from HTCD in good yield, for example, as high as 85 - 98%.
    Type: Grant
    Filed: August 27, 1973
    Date of Patent: May 18, 1976
    Assignee: Teijin Limited
    Inventors: Yataro Ichikawa, Yoshiyuki Yamanaka, Hideki Tsuruta