Abstract: A polyolefin filter for tobacco products and the like was prepared. The extruded element is an open-cell foamed polyethylene or polypropylene having a TPM filtration efficiency greater than 20%. The filter rod can be made by extruding polyethylene containing less than 0.2 moles of a volatile blowing agent per 100 grams of resin at a melt temperature between 130.degree. C. and 150.degree. C., the temperature of the die being between 120.degree. C. and 136.degree. C. Higher melt temperature and die temperature are required for polypropylenes.

Abstract: Multicomponent membranes for gas separation are disclosed which are effective for separating at least one gas from gaseous mixtures by permeation wherein the multicomponent membranes are comprised of a coating in occluding contact with a porous separation membrane. The multicomponent membranes advantageously exhibit less resistance to permeate gas flow for the at least one gas than for at least one remaining gas in the gaseous mixture. For at least one pair of gases the separation factor of the multicomponent membrane is significantly greater than the determined intrinsic separation factor of the material of the coating. Processes and apparatus for gas separation utilizing the multicomponent membranes are also disclosed.

Abstract: Process for the production of small tubing, e.g., hollow fibers comprising(a) preparing a solution of an organic fiber-forming polymer, containing, in a uniformly dispersed form, a sinterable inorganic material;(b) extruding the inorganic material-containing polymer solution through a hollow fiber spinneret;(c) forming a polymeric precursor hollow fiber, laden with the inorganic material;(d) treating the polymeric precursor hollow fiber to remove the organic polymer; and(e) sintering the resulting inorganic material in hollow fiber form.

Abstract: Transversely-fed permeators containing a plurality of selectively permeable hollow fibers suitable for the selective permeation of at least one fluid in a fluid mixture containing at least one other fluid, said fibers being generally parallelly oriented within an elongated shell, are provided with at least one essentially fluid impermeable partition which is substantially transverse to the orientation of the hollow fibers and intermediate a fluid ingress means and a fluid egress means, each of said fluid ingress means and fluid egress means communicating through the elongated shell to the exterior of the hollow fibers, said at least one partition defining zones in said permeator, wherein the zone into which the fluid ingress means communicates is significantly smaller in available membrane surface area to effect the fluid separation than the available membrane surface area in at least one subsequent zone, and means for fluid communication between said zones such that the fluid flow in each zone is substantial

Abstract: Novel bi-metallic filamentary composites are produced by first forming a conjugate precursor filament comprised of an organic polymer together with particles of a first reducible metal oxide and particles of a second reducible metal oxide with the metal component of each of the two metal oxides being sinterable at a temperature which is below the melting point of the other. The structure of the precursor is characterized by a first longitudinally extending layer along its length which contains the particles of the first reducible metal oxide, and an adhering second essentially distinct longitudinally extending layer extending along its length which contains the particles of the second reducible metal oxide. The essentially discrete layers may be in a sheath-core arrangement or in side-by-side relationship.

Abstract: Processes are disclosed for coating the exteriors of a plurality of hollow fibers which are suitable for fluid separations and which are assembled in the form of a bundle. The processes involve immersing the bundle of hollow fibers in a coating liquid containing material suitable for forming the coating and a substantial amount of solvent. A pressure drop from the exteriors to the interiors of the hollow fibers is provided to result in the formation of a deposit on the exteriors of the hollow fibers. The processes of this invention enable essentially the entire exterior surfaces of the hollow fibers to be coated without undue sticking of the hollow fibers or providing undesirably thick coatings on the hollow fibers in any portion of the bundle or on a portion of any of the hollow fibers.

Abstract: A method is provided for fabricating asymmetric acrylic hollow fibers for use in separatory processes as a selective membrane. The fibers are highly permeable and exhibit a high degree of selectivity in discriminating mixtures into their various components. The fibers are formed by extruding an acrylic polymer solution through an annular orifice while simultaneously injecting a coagulating fluid into the bore of the fibers extrudate as it is formed. The extrusion may be directly into a coagulating bath maintained at a temperature of from 60.degree. to 80.degree. or alternatively the freshly extruded fiber may be first passed through an air space (evaporation zone) and thence into the coagulating bath. Following coagulation, the fibers are water washed to remove residual solvent.

Abstract: Hollow filaments, which are suitable for use in separating one or more components from a fluid mixture by selective permeation, are embedded, or potted, in a curable resinous mass, and the resinous mass is severed to expose fluid communication openings of the hollow filaments. In accordance with the invention the curable resinous mass is sufficiently partially-cured to provide a solid mass which can be severed but does not tend to smear when severed so as to obstruct fluid communication openings of the hollow filaments; however, the partial curing is insufficient to render the severings of the resinous mass unduly difficult. The resinous mass is then severed, e.g., by cutting, to provide the fluid communication openings in the hollow filaments embedded in the resinous mass.

Abstract: Hollow filaments, which are suitable for use in separating one or more components from a fluid mixture by selective permeation, are embedded, or potted, in a solid potting mass and the potting mass is severed to expose fluid communication openings of the hollow filaments. In accordance with the invention a thin layer of the solid potting mass having the hollow filaments embedded therein is removed by planing or milling using a knife blade edge moving in an essentially arcuate path at sufficient velocity to cause fracturing of at least one of the hollow filaments and solid potting mass at the point of contact with the knife edge.

Abstract: Processes are disclosed for separating at least one gas from a gaseous feed mixture containing at least one other gas comprising passing the gaseous feed mixture to at least two permeator stages in series. Each permeator stage contains a separation membrane which has a feed side and a permeate exit side and exhibits selective permeation of the at least one gas as compared to the permeation of the at least one other gas of the gaseous mixture. A total pressure differential is maintained across the thickness of the separation membrane in each permeator stage to provide a driving force for the permeation of the at least one gas across the separation membrane. The ratio of total pressure on the feed side to total pressure on the permeate exit side of the separation membrane for at least one permeator stage is less than the ratio of total pressure on the feed side to total pressure on the permeate exit side of the separation membrane for at least one subsequent, i.e., downstream, permeator stage.

Abstract: Ammonia synthesis processes are disclosed which provide enhanced recovery of hydrogen from ammonia synthesis purge streams by selective permeation. The enhanced recovery of hydrogen can provide increased conversion of hydrogen values to ammonia. In the processes, a purge stream from an ammonia synthesis loop at a superatmospheric pressure is passed to at least two permeator stages in series. Each permeator stage contains a separation membrane which exhibits selective permeation of hydrogen as compared to the permeation of each of methane and argon. A total pressure differential is maintained across the thickness of the separation membrane to provide a driving force for the permeation of hydrogen across the separation membrane of each of the permeator stages. Hydrogen permeates through the membrane, and a hydrogen-rich permeating gas is obtained on a permeate exit side of each of the permeator stages. The permeating gas from each of the permeator stages is recycled to the ammonia synthesis reaction zone.

Abstract: Ammonia synthesis processes are disclosed which provide enhanced conversion of hydrogen values to ammonia. In the processes, a purge stream from an ammonia synthesis loop, which purge stream contains ammonia, is contacted at a superatmospheric pressure with the feed side of a separation membrane which exhibits selective permeation of each of hydrogen and ammonia as compared to the permeation of each of methane and argon. A total pressure differential across the membrane is maintained to provide a driving force for the permeation of hydrogen and ammonia through the membrane. A hydrogen-rich permeating gas which contains ammonia is obtained on the permeate exit side of the membrane. The permeating gas is combined with the gas in the ammonia synthesis loop and passed to the ammonia synthesis reaction zone for conversion to ammonia. Ammonia which permeates the membrane can be recovered by the means to remove product ammonia from the gas in the synthesis loop.

Abstract: Essentially inorganic monolithic hollow fibers having a radially anisotropic internal void volume wall structure. Process for the production of such fibers. Apparatus and processes using such fibers.

Abstract: Ammonia synthesis processes are disclosed which provide enhanced conversion of hydrogen values to ammonia. In the processes, a purge stream from an ammonia synthesis loop is treated to reduce its ammmonia content to less than about 0.5 volume percent. The purge stream is then contacted at a pressure of at least substantially the superatmospheric synthesis pressure of the ammonia synthesis with the feed side of a separation membrane which exhibits selective permeation of hydrogen as compared to the permeation of each of methane and argon. A total pressure differential is maintained across the membrane to provide a driving force for hydrogen permeation through the membrane. A hydrogen-rich permeating gas is obtained on the permeate exit side of the membrane. The permeating gas is combined with gas passing to the ammonia synthesis reaction zone for conversion to ammonia. For instance, the permeating gas can be combined with synthesis feed gas or directly introduced into the ammonia synthesis loop.

Abstract: Melt blended fibers of lactam-polyol-polyacyl lactam or acyl polylactam terpolymers together with polyesters are thermally bonded at temperatures below the bonding temperatures of either the crystalline polyester or the terpolymer, resulting in thermally stable fabrics that have bond strength greater than the individual polyester or terpolymer webs bonded at the same temperature.

Abstract: The present invention relates to non-woven fabrics characterized by excellent drapeability, very pleasant handle and good tensile properties. The fabrics are made from melt blends of a polyamide together with lactam-polyol-polyacyl lactam or acyl-polylactam terpolymers.The production of the non-woven webs or fabrics from melt blended fibers of polyamide with lactam-polyol-polyacyl lactam or acyl-polylactam terpolymers is achieved by contact or thermal bonding of melt spun fibers. In one embodiment of the invention, the webs are formed from fibers in the nascent condition as freshly extruded, e.g., they are substantially amorphous. Such amorphous fibers are readily bonded even at room temperature, resulting in autogenous self-bonding, with only little pressure being imposed. If desired these fibers may be bonded at temperatures of up to 210.degree. C.

Abstract: The selectivities of fluid separations of membranes having pores, in which the material of the membranes significantly effects the fluid separations, can be enhanced by the storage of the membranes in water. Suitable materials of the membranes for improvement in accordance with this invention are those which are not unduly susceptible to biodegradation. The membranes for improvement in accordance with this invention preferably have structures which are not unduly affected by drying and thus maintain beneficial mechanical and fluid separation properties after drying.

Abstract: The production of compatible polymeric compositions, fibers and nonwoven webs from three-component blends of a polyamide, a polyester, and a terpolymer of lactam-polyolpolyacyl lactam or lactam-polyol-acyl-polylactam is described in the present patent application.The products of this invention are characterized by having well balanced properties such as dimensional stability to moisture, moisture transport properties, antistatic and tensile properties. The compatible polymeric compositions of the invention are useful in general textile applications such as fibers, woven and nonwoven fabrics, apparel, carpeting, draperies and various industrial forms e.g. articles such as films.

Abstract: Melt blended shaped objects, fibers and fabrics of polyesters with lactam-polyol-polyacyl lactam or -acyl polylactam terpolymers have desirable anti-static properties with the improvement resulting from the presence of the polyol content of the said terpolymer. Such fibers are useful for carpeting, draperies, apparel and nonwoven fabrics.

Abstract: New optically active bis phosphine compounds which are useful in optically active catalysts. Such catalysts are particularly useful in catalytic asymmetric hydrogenation.