Asahi Kasei Kogyo Kabushiki Kaisha

Agency of Industrial Science and Technology

Seiichi Manabe

Takashi Fujiwara

Tetsuo Matsushita

Shuji Kajita

Michitaka Iwata

Mamoru Inoue

Tomio Kuriki

Hiroo Nakano

Hideki Iijima

Takaharu Akedo

Disclosed is a method for the evaluation of the virus-removing capability of a porous polymeric membrane module for removing viruses by filtration, which comprises testing I in which a transmembrane pressure lowering from predetermined value Ph a predetermined period of time after the termination of the supply of a gas is measured with respect to the porous polymeric membrane module, wherein the value Ph satisfies the formula: d&lt;Ph&lt;c, wherein d and c are respectively the transmembrane pressures at points (d) and (c) in FIG. 1 hereof. By the method of the present invention, it has become possible for the first time to effectively and efficiency select a module which can be suitably used for removing viruses from a virus-containing fluid and to obtain to fluid substantially free of the virus.

Method for evaluating the virus-removing capability of a porous

A porous regenerated cellulose hollow fiber is obtained by a micro-phase-separation method. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5.times.10.sup.4, each of the average pore diameter D.sub.1 on the inner wall surface of the hollow fiber and the average pore diameter D.sub.2 on the outer wall surface is 0.02 to 10 .mu.m, the in-plane porosity Pr on the outer wall surface is at least 10%, and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length. The hollow fiber is prepared by a process characterized in that at the steps of extruding a cuprammonium solution of a cellulose from an annular spinning orifice and coagulating, regenerating and water-washing the extrudate, the spinning solution is extruded from an outer annular spinning orifice and a liquid having a coagulating action to the spinning solution is extruded from a central spinning orifice, and micro-phase-separation is caused to occur before the coagulation.

Process for the preparation of a porous regenerated cellulose hollow

A process for separating and condensing at least one selected organic liquid from a feed comprising a mixture thereof in the state of one phase or two phases which comprises conducting ultrafiltration by using a polymeric porous membrane having a mean pore size(2ra ) of at least 10.sup.-6 cm and a porosity (Pr) of at least 50% under the conditions that the effective pressure gradient (.DELTA.P/d) loaded on the polymeric porous membrane satisfies the following equations:

Separation of organic liquid from mixture employing porous polymeric

A method for separation of a liquid mixture wherein a component, intended to be separated, in the liquid mixture is concentrated in the interiors of particles having an average size of 0.1 to 10 .mu.m; the particles are then transported to the surface of a polymeric porous membrane having an average pore size 0.1 to 50 times the average size of the particles under an electrostatic field; and the particles are then separated by a pressure difference loaded on the membrane.

Method for separation of liquid mixture

A porous regenerated cellulose hollow fiber obtained by a micro-phase-separation method is described. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5.times.10.sup.4, each of the average pore diameter D.sub.1 on the inner wall surface of the hollow fiber and the average pore diameter D.sub.2 on the outer wall surface is 0.02 to 10 .mu.m, the in-plane porosity Pr on the outer wall surface is at least 10%, and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length. The hollow fiber is prepared by a process characterized in that at the steps of extruding a cuprammonium solution of a cellulose from an annular spinning orifice and coagulating, regenerating and water-washing the extrudate, the spinning solution is extruded from an outer annular spinning orifice and a liquid having a coagulating action to the spinning solution is extruded from a central spinning orifice, and micro-phase-separation is caused to occur before the coagulation.

Porous regenerated cellulose hollow fiber and process for preparation

A porous regenerated cellulose membrane consisting essentially of cellulose molecules having a viscosity average molecular weight of at least about 5.times.10.sup.4, the crystalline region of the cellulose molecules being substantially cellulose II crystal, cellulose III-2 crystal or the mixture thereof and having a degree of crystal orientation at a face of (101) in the crystalline region in the direction of the surface of the membrane of at most about 40%, the membrane having a dynamic modulus at 30.degree. C. measured with a frequency of 110 Hz of at least about 1.5.times.10.sup.8 (100-pr.rho.) dyn/cm.sup.2 wherein Pr.rho. is a porosity by percentage, a mean pore size represented by D(.mu.m) of about 0.01 .mu.m to about 20 .mu.m and at the same time a porosity in a plane of at least one plane of at least about 30% or a number of pores in a plane per 1 cm.sup.2 of about 6.times.10.sup.5 /D to about 3.times.10.sup.7 /D; and a process for preparing the same.

Porous regenerated cellulose membrane and process for the preparation

A fiber consisting essentially of polyethylene terephthalate capable of being dyed under normal pressure and having an initial modulus at 30.degree. C. of about 55 g/d to about 130 g/d, a relationship between a peak temperature [T.sub.max (.degree.C.)] at the peak of a dynamic mechanical loss tangent (tan .delta.) measured with a frequency of 110 Hz and a peak value of the dynamic mechanical loss tangent [(tan .delta.).sub.max ] represented by the formula:

Process for the production of a polyester fiber dyeable under normal

A high Young's modulus poly-p-phenylene-terephthalamide fiber having a unique fine-structure and excellent properties, including excellent resistance to lateral stress and to friction. The fiber is made by extruding an anisotropic dope in a non-coagulating layer, passing the extrudate through a coagulating layer, washing and drying the resulting coagulated fibers in the absence of substantial tension, and heating the fibers under tension.

Process for the preparation of high Young's modulus

A fiber consisting essentially of polyethylene terephthalate capable of being dyed under normal pressure and having an initial modulus at 30.degree. C. of about 55 g/d to about 130 g/d, a relationship between a peak temperature ]T.sub.max (.degree.C.)] at the peak of a dynamic mechanical loss tangent (tan .delta.) measured with a frequency of 110 Hz and a peak value of the dynamic mechanical loss tangent [(tan .delta.).sub.max ] represented by the formula:

Polyester fiber dyeable under normal pressure

A poly-p-phenylene-terephthalamide fiber with excellent fatigue resistance resulting from a unique combination of properties. The fibers are prepared by extruding an anisotropic polymer dope in a non-coagulating layer, passing the extrudate through a coagulating layer, depositing the resulting coagulated fibers on a net conveyor, and in the absence of substantial tension sequentially washing the fibers, holding the fibers in saturated steam, and drying the fibers under specified conditions.

Growing community of inventors

Ibaraki, Japan

Seiichi Manabe