Japan Exlan Company Limited

Masahiko Ozaki

Toshiyuki Kobashi

Soichiro Kishimoto

Shigeru Nakajima

Yasuo Matsumura

Kenichi Ono

Noboru Abe

Shigeru Sawanishi

Kikuji Katagawa

In packing gels of different activities together into a liquid chromatographic column, this invention provides a method which makes it possible to obtain a remarkably elevated separation performance by packing a gel of high activity in a layer at the outlet side of the column for a length within the range of 5 to 60% of the total packing length.

Method for effective combined use of gels having different activities

This invention provides an industrially advantageous method of regenerating a large quantity of contaminated gels by treating a contaminated gel which has become less active in separation performance with an aqueous solution of a metallic salt or ammonium salt of thiocyanic acid, nitric acid, or hydrogen iodide having a concentration of from 30 weight % to saturation, at a temperature between 50.degree. and 120.degree. C., thereby effectively removing contaminants in the interstices among the gel particles or contaminants on the active points.

Method of regenerating gels for use in liquid chromatography

A process for producing a synthetic rush-like structure which comprises causing an acrylonitrile polymer composition in a substantially melted state (Polymer A or B or C) to flow down towards a spinning orifice; adjusting the pressure of the system in which the melt just before the orifice is present to within a specific range; extruding the melt to form a foamed product; and subjecting the foamed extrudate to heat treatment, thereby obtaining a synthetic rush-like structure resembling the natural rush plant in outer skin structure and internal structure and having excellent sensory and practical properties.

Process for producing a rush-like structure

In a process for producing an acrylonitrile polymer melt in a substantially melted state by polymerizing a monomer mixture containing acrylonitrile in the presence of water at elevated temperature under increased pressure, the polymerization is carried out continuously using a persulfate as the polymerization initiator and under a particular forced stirring as defined in the specification. This process effectively suppresses runaway polymerization reaction, facilitates the melting of the resulting polymer, and in addition produces in an industrially advantageous manner a melt of an acrylonitrile polymer having a moderate molecular weight.

Process for producing an acrylonitrile polymer melt

An improved process for producing an acrylonitrile melt by polymerizing acrylonitrile alone or a monomer mixture consisting of at least 75% of acrylonitrile and as the remainder at least one different ethylenically unsaturated compound in a system where water is present in an amount from 3 to 80% by weight based on the total amount of the monomer(s) and water, under a pressure above the self-generated pressure at a temperature above 80.degree. C. The improvement is characterized by the use of hydrogen peroxide as the polymerization initiator.

Process for producing acrylonitrile polymer melt employing H.sub.2

A process for purifying an acrylic fiber solvent solution which comprises (1) feeding an acrylic fiber solvent containing impurities or an aqueous solution thereof to a packed layer of a polymer consisting of one or more kinds of ester type monomers containing at least one polymerizable double bond and at least one ethylene oxide unit per molecule or a polymer consisting of such monomer(s) and one or more kinds of monomers containing at least one polymerizable double bond for one molecule, to cause said layer to catch the impurities and fiber solvent, (2) passing an eluent through said packed layer thus eluting the impurities together with the eluent, and (3) passing a further amount of the eluent through the packed layer thereby separating an eluate containing the fiber solvent.

Process for refining acrylic fiber solvent containing impurities

Process for producing an acrylonitrile polymer in a substantially melted state by polymerizing a monomer mixture composed mainly of acrylonitrile in the presence of water under a pressure above the autogenous pressure at a temperature of from 80.degree. to 120.degree. C so as to attain a polymerization rate of at least 45%.

Process for producing acrylonitrile polymer melt

Method for opening a high-density packed column in liquid chromatography wherein a large number of components in a solution are separated by means of a column in which a swollen gel is packed at a high density. The improvement involves passing air through the column while heating the column to a temperature above at least 40.degree. C. to shrink the volume of the packed column, and then opening the column. According to this process, there is no loss in the expensive gel nor contamination thereof and yet it's operating efficiency is greatly improved.

Method for opening a high-density packed column in liquid chromatography

The present invention relates to a process for the polymerization of acrylonitrile or a monomer mixture containing acrylonitrile as a main component and at least one other ethylenically unsaturated compound, characterized in that the polymerization is conducted at a temperature above 120.degree. C. under a pressure above the vapor pressure generated in the polymerization system under the polymerization conditions in a system in which water is present in a range of 3 to 50 percent by weight based on the total weight of the monomer(s) and water to produce an acrylonitrile polymer in a substantially molten state. The polymers produced according to the above process have the advantage of being able to be directly shaped by extrusion without the need of solvents.

Process for the polymerization of acrylonitrile

Carbon fibers are produced by continuously heat-treating acrylonitrile fibers up to the crystal collapse starting temperature of said fibers while maintaining said fibers under a fixed length or tension in an oxidizing atmosphere, then sufficiently thermally stabilizing fibers by further subsequently continuously heat-treating them in a temperature range gradually elevated up to a fixed temperature in a range of from a temperature about 20.degree. C lower than the deterioration starting temperature of said fibers to a temperature about 20.degree. C higher than said deterioration starting temperature in an oxidizing atmosphere. The thus sufficiently thermally stabilized fibers are treated with a reducing liquid and subsequently carbonized or graphitized in a non-oxidizing atmosphere or under a vacuum.

Process for producing carbon fibers

Improved carbon fibers (including graphite fibers) are produced by drying acrylic fibers in a water-swollen state spun from an inorganic solvent solution of an acrylonitrile homopolymer or copolymer containing at least 85 mol % acrylonitrile and having an orientation degree of at least 50% and a water content of 5 to 150%. The drying step is carried out at a temperature below 70.degree. C to reduce the water content in said fibers to below 4%. The dried fibers are then heated to form the improved carbon fibers.

A process for producing carbon fibers which comprises (a) treating preoxidized fibers produced from an acrylonitrile fiber with a reducing liquid containing a specific compound and (b) thereafter carbonizing or graphitizing the treated fibers at a temperature above 800.degree. C. The thus-obtained carbon or graphite fibers have a high tensile strength and a high modulus of elasticity.

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Okayama, Japan

Masahiko Ozaki