Abstract: In a pipe forming process using bending rolls, load applied to an upper roll is reduced to suppress the deflection of the upper roll, thereby suppressing creation of large end gap at the longitudinal center of the pipe, thus enabling production of high-strength, thick-walled elongated pipes. This is achieved either by (1) setting the roll spacing L between lower rolls to a value greater than the sum of the diameter Dwu of the upper roll 34 and the diameter Dwl of each of the lower rolls 32, and setting the amount S of tightening of the upper roll 34 with respect to the lower rolls 32 to a value greater than the radius Rwl of each of the plural rolls; or by (2) effecting pipe forming work on the sheet material such that the spacing L of the lower rolls 32 satisfies the following condition: (Dp+Dwl)>L≧0.

Abstract: In a pipe forming process using bending rolls, load applied to an upper roll is reduced to suppress the deflection of the upper roll, thereby suppressing creation of large end gap at the longitudinal center of the pipe, thus enabling production of high-strength, thick-walled elongated pipes. This is achieved either by (1) setting the roll spacing L between lower rolls to a value greater than the sum of the diameter Dwu of the upper roll 34 and the diameter Dwl of each of the lower rolls 32, and setting the amount S of tightening of the upper roll 34 with respect to the lower rolls 32 to a value greater than the radius Rwl of each of the plural rolls; or by (2) effecting pipe forming work on the sheet material such that the spacing L of the lower rolls 32 satisfies the following condition: (Dp+Dwl)>L≧0.

Abstract: A selectively permeable hollow fiber membrane for blood dialysis consisting substantially of a cellulose derivative, which has at least a dense layer on the innermost side and a porous layer of greater void percentage on the outside, and a process for producing the selectively permeable hollow fiber membrane consisting substantially of a cellulose derivative, which comprises extruding a spinning solution containing a polymer consisting substantially of a cellulose derivative dissolved in an organic solvent, from an annular slit into a filamentous form, while simultaneously introducing a core material solution with a water content of at least 50 wt % into the extruded filamentous body, and then immersing the filamentous body into a coagulating solution after passing it through a gas.

Abstract: A hollow fiber blood purifying membrane which is a hollow fiber membrane substantially composed of cellulose acetate, has a substantially non-oriented distribution of cellulose acetate polymer particles on the inner surface of the hollow fibers, has a dense layer with a thickness in the range of 30-1000 nm on both the inner and outer surface of the hollow fibers and a porous structure which is substantially uniform at the membrane wall between the two dense layers, and has an in vitro ultrafiltration rate (UFR) of 10 to 50 ml/m.sup.2 .multidot.mmHg.multidot.hr and a (in vivo UFR)/(in vitro UFR) ratio of at least 0.3, a blood plasma albumin permeation blockage of at least 90%, and an in vivo .beta..sub.2 -microglobulin (.beta..sub.2 -MG) sieving coefficient of at least 0.4, as well as a process for its production.

Abstract: A cellulosic polymer wherein at least a part of the hydroxyl groups of the cellulosic polymer is modified as represented by the following general formula [I]: ##STR1## wherein R.sup.1 and R.sup.2 may be the same or different and each represents a hydrogen atom or a C.sub.1 to C.sub.5 alkyl group, X is a strong negative atomic group, and Y is ##STR2## wherein R.sup.3 and R.sup.4 may be the same or different and each represents a member selected from the group consisting of a hydrogen atom, a C.sub.1 to C.sub.5 alkyl group and a C.sub.3 to C.sub.6 cycloalkyl group, or ##STR3## Y is wherein R.sup.5, R.sup.6 and R.sup.7 may be the same or different and each represents a member selected from the group consisting of a hydrogen atom, a C.sub.1 to C.sub.5 alkyl group, a C.sub.3 to C.sub.6 cycloalkyl group and a C.sub.6 to C.sub.10 aryl group, and n is from 1 to 10. Using the cellulosic polymer, a blood-treating device is assembled.

Abstract: A phosphazene polymer carrier is prepared that has functional groups capable of binding a biologically active substance such as an enzyme or antibody and groups which are non-reactive and hydrophilic. A bifunctional aldehyde is reacted with primary amino groups of a shaped phosphazene polymer to form side chains having aldehyde groups, an amino group-containing compound is reacted with a portion of the aldehyde groups to produce the groups that are non-reactive and hydrophilic, and aldehyde groups not reacted are capable of binding a biologically active substance. The phosphazene polymer may be crosslinked prior to reacting with the bifunctional aldehyde.

Abstract: A phosphazene polymer for immobilizing biologically active substances such as enzymes is prepared that does not lower activity originally possessed by the biologically active substance and does not contain a functionality which can adsorb undesired substances. The polymer has organic radicals having a functional group capable of binding a biologically active substance and organic radicals which are non-reactive and hydrophilic. The non-reactive and hydrophilic organic radicals are preferably prepared by reacting a side chain of the polymer having a primary amino group with formaldehyde or by diazotizing the primary amino group followed by hydrolysis to form a hydroxyl group. A biologically active substance immobilized on the polymer can be used to separate a substance that has affinity for the immobilized biologically active substance.

Abstract: An anti-fungus, deodorant fiber material comprises synthetic polymer fibers, a deodorant material in an amount of 8% by weight or more and consisting of an ethylene-ethylenically unsaturated carboxylic acid copolymer, and an anti-fungus material in an amount of 1% by weight or more and consisting of fine copper particles preferably having a size of 50 mesh or smaller, and the deodorant material and the anti-fungus material are contained together in the synthetic fibers or the deodorant material is contained in one type of synthetic fibers and the anti-fungus material is separately contained in another type of synthetic fibers.

Abstract: An assembly of fibers composed of at least two dissimilar fiber-forming polymers, characterized by the fact that(1) it consists of numerous fibers,(2) at least 90% of said fibers have a non-circular cross-sectional shape,(3) the cross-sections of at least 50% of said fibers differ from each other in at least one of shape and size, and(4) at least 50% of said fibers each have in their cross-section taken at right angles to the fiber axis at least two side-by-side coalesced blocks of at least two dissimilar fiber-forming polymer phases with at least a part thereof being exposed to the peripheral surface of the fiber, at least one of the number, shape and size of the blocks varying from fiber to fiber.

Abstract: Pneumatic cellular aromatic polyamide articles characterized by(a) being articles prepared substantially from aromatic polyamide.(b) said articles having numerous bubbles at the void ratio in the range of 10 to 95%,(c) said bubbles being substantially enclosed in said articles, and(d) said articles having an average thickness in the range of 0.2 to 10 mm on the cross section made by cutting them at right angles to the longest axis.The present invention provides also a process for the preparation thereof. According to the present invention, there are suitably provided pneumatic cellular aromatic polyamide article having a high strength and a wide range of void ratio, comparatively heavy thickness, excellent heat resistance and thermal insulation.

Abstract: A process and apparatus for producing a fibrous assembly. At least one fiber-forming polymer is extruded through a spinneret having numerous small openings. The process uses a die equipped with a spinneret having numerous closely spaced small openings and an opening ratio (.alpha.) of at least 30%. At least one fiber-forming polymer in the form of a shaped mass having a specified compression resistance is continuously stuffed into said die. Said shaped mass has a shape such that it measures more in one direction than in another. There is passed through the spinneret an electric current sufficient to give said fiber-forming polymer Joule heat required for cutting said polymer by partitioning members defining the numerous small openings of the spinneret. The cut fiber-forming polymer is taken up as fine streams.The present invention provides ultrathick aromatic polyamide fibers having an average cross-sectional area of about 0.01 mm.sup.2 to about 5 mm.sup.

Abstract: Pneumatic cellular aromatic polyamide articles characterized by(a) being articles prepared substantially from aromatic polyamide.(b) said articles having numerous bubbles at the void ratio in the range of 10 to 95%,(c) said bubbles being substantially enclosed in said articles, and(d) said articles having an average thickness in the range of 0.2 to 10 mm on the cross section made by cutting them at right angles to the longest axis.The present invention provides also a process for the preparation thereof. According to the present invention, there are suitably provided pneumatic cellular aromatic polyamide articles having a high strength and a wide range of void ratio, comparatively heavy thickness, excellent heat resistance and thermal insulation.

Abstract: An assembly of fibers composed of at least two dissimilar fiber-forming polymers, characterized by the fact that(1) it consists of numerous fibers,(2) at least 90% of said fibers have a non-circular cross-sectional shape,(3) the cross sections of at least 50% of said fibers differ from each other in at least one of shape and size, and(4) at least 50% of said fibers each have in their cross section taken at right angles to the fiber axis at least two side-by-side coalesced blocks of at least two dissimilar fiber-forming polymer phases with at least a part thereof being exposed to the peripheral surface of the fiber, at least one of the number, shape and size of the blocks varying from fiber to fiber.

Abstract: The present invention provides a process for producing a fibrous assembly, which comprises extruding a melt of a fiber-forming polymer through a mesh spinneret, said spinneret including many closely arranged small openings and having an opening ratio (.alpha.), represented by the following formula, of at least about 10% ##EQU1## V.sub.a is the total apparent volume of the spinneret which is taken within a unit area of its mesh portion, and V.sub.

Abstract: A composite sheet structure comprising (A) a nonwoven web composed of (a) continuous filaments of a synthetic resin and (B) a net-like web having intersecting points and being composed of (b) continuous net strands of a mixture consisting of at least two thermoplastic synthetic resins having different melting points, said web (A) and said web (B) being bonded to each other by heating; characterized in that (i) said web (A) has a basis weight of about 2 to about 30 g/m.sup.2, (ii) said web (B) has a basis weight of about 1 to 10 g/m.sup.2, an average net strand diameter of about 1 to about 100 microns, and an average mesh length of up to about 5 mm, and said net strands (b) are composed of at least two resins having melting points differing from each other by at least about 20.degree. C., of which a resin having the lowest melting point has a melting point at least about 20.degree. C.

Abstract: A fibrous composite comprising a coalesced assembly of (A) a sheet-like mesh structure composed of fibers of a synthetic elastomeric polymer, the individual fibers being interconnected at random in irregular spaced-apart relationship thereby forming a number of meshes of different shapes and sizes, said mesh structure having a recovery ratio after 10% stretch of at least 70% in two arbitrarily selected, mutually perpendicular directions on the plane of said mesh structure, and (B) a mat-, web- or sheet-like fibrous structure composed of short or long fibers, said fibrous structure having a recovery ratio after 10% stretch of less than 50% in at least one arbitrarily selected direction. An elastic fibrous composite of this invention is suitable as various apparel base materials and industrial materials such as filter clothes, adsorbents, and heat insulating materials.

Abstract: A novel composition comprising 100 parts by weight of an aromatic polyester, 5 to 150 parts by weight of powdery feldspar and optionally 5 to 120 parts by weight of a plate-like inorganic filler such as glass flakes and/or 1 to 100 parts by weight of a rubbery elastomer such as acrylic rubber. Up to a half of the powdery feldspar may be replaced by another pulverulent inorganic filler such as talc. The composition is useful as engineering plastics because it gives molded articles having high impact strength and heat distortion temperatures and reduced warping.