Asahi Kasei Kogyo Kabushiki Kaisha

Kunihiko Takeda

Tetsuya Miyake

Akihiko Ikeda

Maomi Seko

Kazuo Imamura

Tatsushi Saeki

Kohji Inada

Hatsuki Onitsuka

Norito Ogawa

Heiichiro Obanawa

Naoki Miyata

Yasuki Shimamura

Kazuo Okuyama

Keishi Tada

Masayuki Mizuno

A process for continuously separating uranium isotopes by an oxidation-reduction reaction using an anion exchanger comprising the steps of feeding an eluant containing a deactivated oxidizing agent and a deactivated reducing agent to an anion exchanger to regenerate them and to form an oxidizing agent zone in the anion exchanger, and reusing the regenerate reducing agent and the oxidizing agent zone for further uranium isotope separation.

Continuous chromatographic separation of uranium isotopes

In a process for continuously separating uranium isotopes, .sup.235 U and .sup.238 U, by oxidation-reduction chromatography using a column of an anion exchanger, the separation of uranium isotopes and the regeneration of the oxidizing agent and reducing agent both deactivated during the separation of uranium isotopes can be simultaneously effected in a single column by returning to and passing through the column of an anion exchanger having a uranium adsorption zone an eluate containing a deactivated oxidizing agent and a deactivated reducing agent to regenerate the deactivated oxidizing agent and the deactivated reducing agent and to form an oxidizing agent zone, and returning to and passing through the column the regenerated reducing agent for the reduction of uranium.

Process for separating uranium isotopes by oxidation-reduction

Novel benzimidazolyl compounds which are basic compounds and have high polymerizability are disclosed. The basic compound of the present invention is prepared by reacting a vinylbenzaldehyde with an o-phenylenediamine compound, and can be used, for example, as a monomer for polymers. The benzimidazolylstyrene compounds are readily homopolymerized or copolymerized to provide linear homopolymers, linear copolymers or cross-linked copolymers having pendant benzimidazolylphenyl groups. These polymers have greater resistance to oxidation and chemicals than the homologues, and are useful as ion exchange resins, and as extractants of metals.

Basic compound, its polymer, a process for the preparation thereof and

Novel imidazolylmethylstyrene compounds which are basic compounds and have excellent resistance to oxidation and high polymerizability are disclosed. The basic compound of the present invention is prepared by reacting a halogenomethyl-styrene with an imidazole compound, and can be used, for example, as a curing agent for epoxy resins. The imidazolymethylstyrene compounds are readily homopolymerized or copolymerized to provide linear homopolymers, linear copolymers or cross-linked copolymers having pendant imidazolylmethylphenyl groups. These polymers have greater resistance to oxidation than the homologues, and are useful as an ion exchange resin, extractant of metals, sizing agent and antistatic agent.

Novel basic imidazolylmethylstyrene compound, its polymer, a process for

Method for the separation of carbon isotopes by chemical exchange method

A process for the separation of one rare earth metal from another in a mixture of rare earth metals by chromatographic displacement using a complexing agent and a cation exchanger, which process comprises using a cation exchanger having a micro-void volume void ratio of 0.5 to 0.95, preferably 0.5 to 0.88.

Separation of rare earth metals using a cation exchanger

A nitrogen-containing acrylic copolymer composition comprising:

Nitrogen-containing acrylic copolymer composition

A process for the enrichment of one isotope in a mixture of uranium isotopes by passing a solution of the mixture in a solvent through an anion exchanger thereby forming on the anion exchanger a boundary (A) between a uranium adsorption zone and an adjacent reducing agent zone and/or a boundary (B) between a uranium adsorption zone and an adjacent oxidizing agent zone, the uranium adsorption zone advancing through the anion exchanger, effecting reduction at the boundary (A) and/or effecting oxidation at the boundary (B), thereby effecting enrichment adjacent said boundary, and separating a fraction enriched in one of said isotopes, which process comprises using as the solvent medium a composition comprising (a) a solvent having a dielectric constant of at least 80 at 20.degree. C., (b) hydrochloric acid and (c) at least one of hydrobromic acid and sulfuric acid, the solvent medium having a hydrogen ion concentration of about 0.1 M/l to about 10 M/l, a total chlorine ion concentration of about 0.1 M/l to about 12 M/l, at least one of bromine and sulfate ion being present in about 0.01 M/l to about 10 M/l and the other being present in from zero up to 10 M/l, and passing the materials through the ion exchanger at a rate such that the migration velocity of the uranium adsorption zone through the ion exchanger is at least about 1 cm per minute.

Ion exchange enrichment of uranium isotopes

A basic copolymer whose main chain is cross-linked which comprises about 6 to about 98% by weight of recurring units of Formula (A) or (B), ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3, which may be the same or different, each represents a hydrogen atom or a hydrocarbon group selected from the group consisting of C.sub.1-20 alkyl groups, C.sub.3-10 cycloalkyl groups, C.sub.3-8 alkenyl groups, C.sub.6-15 aryl groups, C.sub.7-12 arylalkyl groups and C.sub.1-15 aminoalkyl groups; and X is an acid radical, and about 2 to about 94% by weight of cross-linked units based on the total weight of the recurring units of Formula (A) or (B) and the cross-linked units and, if desired, up to about 92% by weight of units of a monoethylenically unsaturated monomer or a conjugated monomer based on the total weight of the recurring units of Formula (A) or (B), the cross-linked units and the units of the monoethylenically unsaturated monomer or the conjugated monomer.

Novel basic cross-linked polymers

An isotope separation apparatus comprises a plurality of independent developing units, each comprising 2 to 20 adsorbent-packed columns forming a continuous developing circuit or passageway, and the developing units are connected to at least one common main pipe for supplying an isotope mixture solution, a regenerating agent solution, or an eluent solution. Also, in a further embodiment the developing units are connected to common liquid-discharge main pipes. The separation or concentration of isotopes such as uranium isotopes, nitrogen isotopes, boron isotopes, etc., is performed by continuously developing the isotope mixture solution passed through the individual adsorbent-packed columns successively in each developing units.

Isotope separation

A mixture containing formaldehyde and water is separated effectively by contacting with adsorbents of specific type A zeolites containing exchanged cations of the elements from Group IA (4) to (6) or Group IIA (6) or mixture thereof of the Periodic Table of Elements.

Purification of formaldehyde by separation

A novel protein adsorbent consisting essentially of a porous copolymer obtained by copolymerizing a monomer mixture comprising at least one cyano group-containing monomer and at least one cross-linkable monomer, said copolymer having an average pore diameter (d) of from 40 A to 9,000 A and a total pore volume of from 0.05.sqroot.X ml to 1.5.sqroot.X ml per gram of the copolymer in a dry state, in which X designates the weight proportion of said cross-linkable monomer expressed in terms of the percent by weight based on the total monomers. The present porous copolymer adsorbent has a remarkably high protein adsorbing capacity. The adorbent can advantageously be used for various purposes such as purification and separation of proteins, and removal of proteins. Copolymer-protein composites obtained by adsorption of proteins on the present porous copolymer also are industrially useful and have a wide variety of applications.

Protein adsorbent

A hydrocarbon mixture is fed to a system of adsorbents in a plug flow so as to form at least one displacement boundary in the system to accumulate the composition in the vicinity of the boundary. The process is simple to operate and suitable for separation of a hydrocarbon mixture containing components with similar physical and chemical properties such as a mixture of hydrocarbon isomers.

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Yokohama, Japan

Kunihiko Takeda