Abstract: A method of providing a composite sheet material which has soft and pliable hand characteristics, despite being dense, and also high resistance against discoloration and deterioration. The method comprises impregnating and/or coating a fibrous sheet with a mixture of (A) a polyurethane elastomer containing a sterically hindered amino group within its molecular chain, (B) a compound selected from the group consisting of a polybasic acid and its halide, metal salt and ammonium salt, wherein one or more hydrogen atoms remain unreacted, which amount of (B) is within the range of 0.8-5 molar equivalents relative to the sterically hindered amino group, and (C) a solvent for the polyurethane elastomer (A), and subjecting the resulting material to wet coagulation.

Abstract: A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.

Abstract: A process is disclosed for producing a composite reverse osmosis membrane. The process involves forming a porous polysulfone membrane from a solution of polysulfone followed by quenching the polysulfone membrane in an aqueous solution of m-phenylenediamine followed by reacting the m-phenylenediamine on the polysulfone membrane with either trimesoyl chloride or cyclohexane-1,3,5-tricarbonyl chloride in a water immiscible solution thereof.

Abstract: A method for producing a polishing pad is disclosed. The method involves uniformly fully impregnating a fibrous batt with an aqueous polyurethane dispersion, coagulating the polyurethane dispersion to form an impregnant and drying the impregnant. The aqueous polyurethane dispersion may include colloidal silica. Heat and pressure are applied simultaneously to at least one surface of the impregnant to form a composite having a bulk density approaching the actual density of the impregnant at the polishing surface while maintaining microporosity throughout the structure. An adhesive is applied to the surface opposing the polishing surface to form an adhesive backed polishing pad. The polishing pad is comprised of a polymer homogeneously impregnated fibrous batt with the polishing surface having a bulk density approaching its actual density.

Abstract: A gelation shrinkable, polymer casting solution, that has been cast on the internal surface of a tubular support is gelled using pressure gelation by supporting the tubular support with one end higher than the other and pumping gelation liquid upwardly along the tube at a velocity in the range of the order of 10 to 100 cm/second and at a pressure of at least 10 kPa gauge at all points of contact between the gelation liquid and polymer casting solution. This achieves asymmetricity of the pore structure and ensures that the cast polymer solution is continuously in contact with the tubular support as a gelled membrane. If the tubular support is a porous, tubular support, then preferably the pressure gelation is continued until gelation liquid has passed through the cast polymer solution and the porous support removing solvent and any additives from the cast polymer solution.

Abstract: A process for manufacturing porous textile substrates impregnated with thermoplastic polymeric pastes, especially fleeces or mats, with subsequent gelling out of polymeric paste, which comprises penetrating impregnating one side of a textile substrate with an evacuated paste comprised of a vinyl polymer and/or copolymers of vinyl chloride, while effecting complete displacement of air through the paste and compactly impregnating said substrate.

Abstract: Preparation of supported reverse osmosis membranes on a woven, unsized, porous support using dimethylacetamide solvent and a lithium nitrate or chloride or magnesium chloride salt.

Abstract: An aqueous coating composition is comprised of an aqueous anionic polyurethane dispersion and a salt of hydrofluorosilicic acid, wherein the pH of the composition is acidic and the composition is thixotropic. The composition is particularly useful for coating irregular substrates to form a regular surface thereon.

Abstract: The present invention provides a method for manufacturing a fabric-type artificial leather, wherein a nonwoven fabric is formed by using a dry method to join together hydrophobic fibers. The fabric so formed is densified by needling and the activation of shrinking forces. It is then impregnated with a mixture of a heat sensitive elastomeric bonding agent, powdered barium sulfate and a compound that reacts with acid to form a gas. The impregnated fabric is then exposed to a heated, acidified liquid which triggers coagulation of the bonding agent and liberates a gas formed by reaction of the acid and acid-reactive compound. The resulting solidified fabric is then washed, dried and ground-over on at least one side to produce a nap. Finally, the fabric is intensively fulled.

Abstract: A moisture-permeable waterproof coated fabric having a microporous polyurethane layer is obtained by the so-called wet coagulation method using as a coated solution a polar organic solvent solution containing 8 to 25% by weight of a polyurethane elastomer, 0.1 to 10% by weight of a water repellent agent, 0.2 to 3% by weight of polyisocyanate and 1 to 8% by weight of a nonionic surfactant.

Abstract: A base fabric for polyurethane-coated fabics which comprises a layer of polyurethane prepolymer under half cross-linked conditions partially formed on at least one surface of the water repellent-unfinished fabric. A process for the production of a base fabric for polyurethane-coated fabrics, which comprises partially coating a solution of polyurethane prepolymer containing a cross-linking agent on at least one surface of the water repellent-unfinished fabric, drying and aging until the polyurethane prepolymer is caused to be under half cross-linked conditions. A polyurethane-coated fabric, which comprises a one-pack polyurethane layer with fine air-permeable pores formed on a water repellent-unfinished base fabric having partially formed on at least one surface thereof a layer of a two-pack polyurethane resin, the fabric and one-pack polyurethane layer being adhered to the layer of the two-pack polyurethane resin as a result of a cross-linking reaction of the polyurethane prepolymer.

Abstract: Improved sheet material of the type where a base sheet is provided with an opaque microvoid-containing layer which can be locally transparentized by applying a colorless liquid which is a non-solvent for the layer. Indicia remain more sharply defined by including in the layer an organic polymer which jellifies in the presence of the liquid and blocks lateral migration.

Abstract: A hydrophilic surface can be provided on a hydrophobic polymer surface by contacting the hydrophobic surface with a solution of a hydroxyalkyl cellulose and a perfluorocarbon surfactant in water or a mixture of water and one or more aliphatic alcohols so as to form a layer of the solution on the hydrophobic surface and then heating the surface coated with the layer so as to remove the solvent, so as to form a bond between the cellulose and the hydrophobic surface. This results in the formation of a hydrophilic surface coating a layer on the hydrophobic surface. Hydrophilic surfaces as are created in this manner are primarily intended to be utilized on polysulfone surfaces in semipermeable membranes such as are utilized in micro- and ultra-filtration.

Abstract: A process for preparing a selective permeable membrane having self-supporting property, which comprises coating on a supporting substrate a dope comprising a polyimide polymer consisting essentially of a repeating unit of the formula: ##STR1## wherein R is a divalent organic group, an inorganic salt and an organic solvent, as a dope solvent, which dissolves a mixture of the polymer and the inorganic salt to form a homogeneous system, to prepare a dope coated supporting substrate, heat treating the substrate at a temperature which does not cause the organic solvent in the dope to boil, and then coagulating the substrate.

Abstract: A process for the production of chemically bonded non-woven material, such as synthetic leather, is disclosed wherein a fiber fleece is impregnated with a heat sensitized polymer dispersion and the composition is destabilized to form a porous gel structure. Finally, the polymer is crosslinked at below 150.degree. C. and is dehydrated. Additionally, cut fibers of polyester of polyamide are formed into a fleece and an aqueous dispersion of butadiene-styrene coagulant and a curing composition is impregnated through the fleece. The binder is gelled and cured in superheated steam. The products obtained are soft and possess excellent physical and mechanical properties as well as superior dynamic stressability.

Abstract: A process is described for preparing a selective permeable membrane comprising coating a solution consisting essentially of(i) a polyimide polymer consisting essentially of a repeating unit of the formula (I): ##STR1## wherein R.sup.1 is a divalent organic group, (ii) a swelling agent selected from the group of compounds represented by formula (II) and (III):R.sup.3 O----CH.sub.2 CHR.sup.2 O).sub.n R.sup.4 (II)R.sup.5 ----OH).sub.m (III)wherein R.sup.2, R.sup.3 and R.sup.4, which may be the same or different, can be hydrogen, a methyl group, or an ethyl group, and when R.sup.2 is hydrogen, n can be an integer of from 1 to 5, and when R.sup.2 is a methyl or ethyl group, n can be an integer of from 1 to 3, R.sup.

Abstract: A resin impregnated fibrous web is comprised of a needled fibrous batt and a polymeric resin distributed throughout the batt. The density of the impregnated web is uniform throughout with the bulk density of the web being less than the actual density of the web whereby the web is porous. The impregnated web has filaments which are both coated and uncoated with the polymeric resin. A method of forming the impregnated fibrous web is also disclosed.

Abstract: An aqueous polyurethane composition capable of thermal coagulation is disclosed. The polyurethane composition is comprised of an aqueous polyurethane dispersion having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group. The composition also includes a compound which, when heated in an aqueous solution, generates acid which causes displacement of the cationic compound from the covalently bonded anionic groups. A method of forming a composite sheet material is also disclosed. The composite sheet material is formed by impregnating a porous sheet material with the polyurethane composition and heating the impregnant to generate acid causing coagulation of the polyurethane dispersion in the porous sheet material. The impregnant is dried to form a composite sheet material.

Abstract: A selective permeable membrane and a process for preparing the membrane. The process comprises applying to a supporting substrate a membrane forming solution prepared by dissolving in an organic solvent a polyimide polymer comprising principally a repeating unit represented by the general formula (I): ##STR1## wherein R.sup.1 represents a divalent organic group, and a liquid swelling agent having a coagulation value with respect to the polyimide polymer of about 50 to about 200 and a boiling point of about 50.degree. C. to about 120.degree. C. under atmospheric pressure, evaporating at least a part of the swelling agent, and coagulating the polyimide polymer by contacting the polyimide polymer with a coagulating solvent which does not dissolve the polyimide polymer but is compatible with the organic solvent and the swelling agent.

Abstract: A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of a microporous substrate, the polymeric material being prepared by crosslinking a soluble polymer containing at least 30 mole % of a recurring unit of the formula ##STR1## wherein all symbols are as defined herein, and having at least 0.5 milliequivalent, per gram of said polymer, of an amino group containing 1 or 2 active hydrogen atoms, with a polyfunctional compound containing at least two functional groups capable of reacting with the amino group having 1 or 2 active hydrogen atoms; and a process for preparing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Abstract: A semipermeable membrane made of a polyaryl ether sulfone comprised of recurring units represented by the general formula (I): ##STR1## wherein X, X', X" and X'" are non-dissociative substituents, and l, m, n and o are integers of from 0 to 4. The membrane, which is composed of a single continuous polymer phase, has pores of a diameter increasing progressively and continuously from the surface layers to the center portion thereof.The membrane is prepared by the process wherein:the polyaryl ether sulfone is dissolved in a mixed solution to form a dope of the polyaryl ether sulfone;the polyaryl ether sulfone dope is extruded to form a fiber or film and, then;both sides of the fiber or film are contacted with a liquid miscible with the mixed solvent but incapable of dissolving the polyaryl ether sulfone to remove substantially all the mixed solvent from the fiber or film.

Abstract: A composite synthetic leather sheet material and method of manufacture thereof is disclosed. The composite sheet material comprises outer thermoplastic polymeric layers bonded to opposite faces of a reinforcing textile fabric, preferably a porous woven fabric of high strength material, by an intermediate polymeric layer which fills the interstices of the fabric and has opposite surfaces disposed adjacent the fabric surfaces to engage and firmly secure the outer thermoplastic polymeric layers in the composite sheet. One of the outer thermoplastic layers is foamed to a relatively high degree and the outer surface of the foam is mechanically abraded or buffed to provide a suede-like leather appearance thereto. The other outer thermoplastic layer may be foamed and provided with an embossed leather-like surface appearance. The sheet material product is reversible in use, completely heat-sealable, flow-moldable, and printable on both sides for subsequent manufacture of synthetic leather good articles.

Abstract: An improvement in the method of casting a reverse osmosis or ultrafiltration polymeric membrane on a wall of porous support having a first, high pressure side under service conditions, and a second, low pressure side under service conditions, wherein the first side is coated wih a cellulose ester casting solution to at least partially impregnate the support, solvent carrier of the casting solution is partially evaporated to leave a residue, and then residues adjacent the first and second sides are gelled with a gelation liquid comprising a monohydric alcohol. The improvement comprises gelling the residue adjacent the first side with a gelation liquid which is separate from that used to gel the residue adjacent the second side, and the monohydric alcohol mole fractions of the separate gelation liquid, and their temperatures during gelation, are chosen so that relatively larger pores are formed towards the second side of the porous support.

Abstract: The specification describes water vapor-permeability sheet materials, particularly useful in the footwear industry. The production of sheet materials which are water permeable, highly resistant to wear, water resistant and mechanically stressable occurs by mechanically foaming a polymeric dispersion, the mechanical foaming being carried out in the presence of a surfactant, the density of the film being adjusted by the mechanical foaming to 0.55-0.85 g/cm.sup.3, gelling the foamed dispersion at a temperature of 120.degree. to 220.degree. C., for at most 10 minutes, and finishing the sheet material by spraying and/or rastering.

Abstract: The discovery that highly anisotropic membranes, e.g. with a degree of anisotropy of five can for the very first time be produced by the dry phase inversion process by a very specific combination of polymers, solvent and non-solvent, optionally along with plasticizers and modifiers, all of which separately are known in membrane technology, the polymers consisting essentially of cellulose nitrate and cellulose nitrate-cellulose acetate mixed ester polymers, the solvent being methyl formate, propylene oxide, or mixtures thereof, and the non-solvents being isopropyl alcohol, t-butyl alcohol or mixtures thereof, is disclosed.

Abstract: An aqueous polyurethane composition capable of thermal coagulation is disclosed. The polyurethane composition is comprised of an aqueous polyurethane dispersion having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group. The composition also includes a compound which, when heated in an aqueous solution, generates acid which causes displacement of the cationic compound from the covalently bonded anionic groups.A method of forming a composite sheet material is also disclosed. The composite sheet material is formed by impregnating a porous sheet material with the polyurethane composition and heating the impregnant to generate acid causing coagulation of the polyurethane dispersion in the porous sheet material. The impregnant is dried to form a composite sheet material.

Abstract: A process for producing a rigid orthopedic cast in which a bandage material is provided which is impregnated or coated in the form of webs or sheets with a solvent solution of a polyurethane prepolymer, a bifunctional chain-extender and a catalyst. The prepolymer urethane having two isocyanate end groups, being formed by the reaction of a bifunctional compound reactive with an isocyanate group with a molar excess of a diisocyanate, forms a final thermoplastic polymer in the presence of the chain-extender when the solvent is removed under evaporative conditions. The heated thermoplastic impregnated fabric can be wrapped in multiple layers under normal conditions around a broken body member, molded and cooled to form a strong, rigid supportive cast which is porous so as to prevent skin maceration or other medical ramifications related to a non-porous material.

Abstract: A method of making a membrane comprised of a hydrochloric acid-insoluble sheet of a mixture of a rubber and a powdered ion transport material is disclosed. The sheet can be present as a coating upon a flexible and porous substrate. These membranes can be used in oxidation-reduction electrical accumulator cells wherein the reduction of one member of a couple is accompained by the oxidation of the other member of the couple on the other side of the cell and this must be accompained by a change in chloride ion concentration in both sides. The method comprises preparing a mixture of fine rubber particles, a solvent for the rubber and a powdered ion transport material. The mixture is formed into a sheet and dried to produce a microporous sheet. The ion transport material includes particles ranging from about 0.01 to 10 microns in size and comprises from 20 to 50 volume percent of the microporous sheet.

Abstract: Asymmetric reverse osmosis membranes are made from synthetic aromatic polyimides having a relatively high predominance of polar groups in the polymer backbone. A polar/non-polar group ratio of from 2:2 to 2:7 per imidized nitrogen link is required. Such membranes can be fabricated using conventional casting equipment by providing a solution of the polyimide in a good solvent and a poor solvent, the poor solvent being compatible with solution components at poor solvent/good solvent ratios of at least 1:1 up to about 7:1, casting a film of such solution, and partially evaporating the exposed surface of the cast film for 100.+-.30 seconds prior to gelation.

Abstract: The present invention is concerned with a method for improving the water storage capacity of textile substrates, particularly fleece based artificial leathers by treatment with a hydrophilizing agent. This agent, once applied to the substrate is insoluble in but swellable in water. The agent in an uncross-linked state is water soluble and has a turbidity point of between about 25.degree. and 95.degree. C. in a 25% aqueous solution. The agent may be applied to the substrate from aqueous solution and then cross-linked or it may be applied to an inert carrier such as kaolin, cross-linked and applied to the substrate from an aqueous suspension. A particularly suitable agent is a polyether with a molecular weight of between 500 and 8500, an ethylene oxide content of about 35 to 80 wt. % and cross-linkable end groups. The end groups may be self cross-linking such as vinyl groups or they may be cross-linkable via a cross-linking promoter such as hexamethylol melamine.

Abstract: A composite permselective membrane is prepared by reaction of a film or layer containing cycloaliphatic polyfunctional secondary amines with a triacyl halide or its mixture with a diacyl halide. The membrane is useful in separating components of fluid mixtures or solutions, such as the removal of salts from aqueous solutions by reverse osmosis.

Abstract: A process for preparing a microporous polymeric membrane, which process comprises preparing a polymer-casting solution, casting a thin film of the casting solution on a support base, allowing partial evaporation of the solvent from the cast film for a predetermined period of time and contacting the partially evaporated cast film with the microporous leaching liquid to provide a membrane, the improvement which comprises: providing a casting solution which comprises a vinylidene fluoride polymer and from about 35 to about 85% by weight of a vinyl acetate polymer; and hydrolyzing the acetate polymer after the leaching step to convert the acetate groups to hydroxyl groups, to provide an improved membrane having good mechanical strength and hydrophilic properties.

Abstract: Textured sheet material is produced by a process which includes two printing steps and two separate applications of plastisol in the form of discontinuous layers. The plastisol layers are applied over respective of the printed patterns and the first layer of plastisol is gelled, but not fused, prior to the second printing step which provides an image thereon. The process enables production of a relief pattern having "valleys" of two different depths.

Abstract: A semipermeable composite membrane comprising a thin semipermeable film of a polymeric material deposited on one side of the microporous substrate, said polymeric material being prepared by interfacial crosslinking of a polymer containing a recurring unit of the formula ##STR1## wherein each of R.sub.1 and R.sub.2 represents a hydrogen atom or a methyl group, and W.sub.1 represents a direct bonding or a sulfonyl group (--SO.sub.2 --), with a polyfunctional compound containing at least two functional groups selected from acid halide, sulfonyl halide, isocyanate, N-haloformyl, haloformate and acid anhydride groups; and a process for producing the same. The semipermeable composite membrane of this invention is especially useful for desalination of saline or brackish water by reverse osmosis.

Abstract: A composite material comprising a fibrous sheet which is impregnated with a polyurethane elastomer. The polyurethane elastomer comprises the reaction product of(A) a polymeric diol having a molecular weight of about 800-4000;(B) an organic diisocyanate having the formula (I) ##STR1## wherein R' and R.sup.2 are hydrogen or an alkyl group having 1-5 carbon atoms, respectively, and(C) a chain extender comprising an organic diamine having the formula (II) ##STR2## wherein R' and R.sup.2 are hydrogen or 40-95 mole % alkyl group having 1-5 carbon atoms, respectively, and a phthalic acid dihydrazide having the formula (III) ##STR3## This composite sheet material is useful as a synthetic leather, especially as a suede-like leather sheet material, and has high density, good flexiblity and crease resistance, a supple touch and 60-5 mole % pertinent rubber-like repulsive elasticity.

Abstract: An artificial leather sheet material, comprising a layer of permeable fabric made of interlaced multifiber yarns, the lower face of said fabric having an open nap of fibers teased from said yarns and bonded together, and a continuous layer of polymer material on the upper face of said fabric. The bonded nap may be subjected to spaced short cuts to give it a rough appearance.

Abstract: This invention is concerned with a process for producing microporous coatings comprising (1) mixing an NCO-prepolymer prepared from polyisocyanates with compounds containing at least two isocyanate-reactive hydrogen atoms with about 3 to 40% by weight, based on the NCO-prepolymer, of a substantially inert, non-migrating liquid organic compound miscible with said NCO-prepolymer as a plasticizer; (2) adding about 3 to 300 weight % of water, based on the NCO-prepolymer, into the NCO-prepolymer-plasticizer mixture to form a water-in-oil emulsion; (3) adding a polyamine in a quantity substantially equivalent to the isocyanate groups; (4) applying a coating of the water-in-oil emulsion to a substrate; and (5) hardening the coating by evaporating the chemically unbound water from said coating.

Abstract: A mixture of at least one non-sulphonated polysulphone and at least one sulphonated polysulphone, this mixture consisting of 10 to 30% by weight of a sulphonated polysulphone which has a theoretical exchange capacity of from 500 to 1,200 meq/kg is provided. Such mixtures enable one to obtain semi-permeable membranes using relatively concentrated solutions of the mixtures. The resulting membranes are particularly suitable for use in ultrafiltration.

Abstract: A thermoplastic polyurethane comprising the polymerization product of a long-chain diol, a low molecular weight chain-extender, an organic diisocyanate and a specific diol compound. The specific diol compound is represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.2 are hydrogen or an alkyl radical having from 1 to 3 carbon atoms, R.sub.3 and R.sub.4 are an alkylene radical having from 2 to 4 carbon atoms, Y is a bivalent radical selected from the group consisting of ##STR2## wherein x is hydrogen, chlorine, bromine or a methyl radical, m and n are positive integers satisfying the formula 2.ltoreq.m+n.ltoreq.10when Y is ##STR3## or m and n are zero or positive intergers satisfying the formula 0.ltoreq.m+n.ltoreq.10when Y is ##STR4## The thermoplastic polyurethanes are suitable for producing artificial leathers having improved properties such as moderate elasticity, resistance to microorganisms, cold, stickiness and nitrogen oxide gas.

Abstract: An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.

Abstract: Covers an immersible molecular filter unit having a body that is formed from a porous polymeric material of generally cylindrical shape, preferably rounded at least at one of its ends. A tubular connector is mounted at one end of this body, with a bore that communicates with the porous network of the body. An anisotropic membrane encapsulates the body and is formed with an integral collar portion that engages about a portion of the connector, where it projects from the body, in substantially fluid-tight fashion. Preferably the membrane, which is formed in situ, is shrunk about the tube and the body, and is solvent welded to the connector.This unit is formed by dipping the body and the juxtaposed connector in a polymer casting solution, to encapsulate the porous body and a part of the connector. The dip-coating unit is then converted to an anisotropic membrane.

Abstract: A method of preparing a composite sheet material having properties similar to leather is provided. At least a portion of a porous sheet material is impregnated with an aqueous ionic dispersion of a polyurethane polymer. The polyurethane polymer which is impregnated in the porous sheet is ionically coagulated from the dispersion. Preferably, both the ionic dispersing and coagulating media are removed from the impregnated sheet. The impregnant is then dried to form a composite sheet material.

Abstract: A process of producing a porous polyurethane resin filter material. A first solution containing an NCO-adduct dissolved in a highly polar organic solvent is admixed into a second solution containing a highly polar organic solvent and at least one hydrazine hydrate, carbodihydrazide, piperazine and 1,4-diaminopiperazine. The first solution is admixed into the second solution over an extended period of time during which time the viscosity of the admixture is monitored and during which time the NCO pre-adduct and the hydrazine (or the like) react to form a polyurethane reaction product. During this time, the viscosity of the admixture increases. Admixture is continued with monitoring of the viscosity of the admixture until a point is reached at which the addition of even the minutest amount of the first solution into the admixture would result in instantaneous gelling thereof. At this point, the solids content of the final admixture is between 15 and 35% by weight.

Abstract: A glass-fiber filter tube and process of preparing the filter tube, which filter tube comprises a plurality of randomly disposed, fine glass fibers bonded, at the junction of the fibers, with a fused thermoplastic fluorocarbon resin, which filter tube may also include a reinforcing support scrim sheet incorporated integrally therein.

Abstract: A base material for artificial leather having a water vapor absorption capacity of from 2 to 8% by weight, based on a fibre fleece impregnated with a rubber latex mixture containing a heat sensitizer, a quick-acting vulcanization accelerator and, as expanding agent, a silicone oil emulsion or an inert, emulsifiable substance which is insoluble both in the rubber and the other constituents of the latex. After the impregnation of the fibre fleece, the latex mixture is coagulated by heat, vulcanized and then dried.

Abstract: A printed circuit board made by providing on an insulating substrate an adhesive coating comprising a butadiene-based rubber and a phenolic resin finely dispersed therein, etching the surface layer of said coating with an oxidizing agent to expose the microcapsules having phenolic resin shells, which have been formed during the setting of said adhesive coating, and forming a chemically deposited metal layer on said adhesive coating.

Abstract: A base material for artificial leather having a water vapor absorption capacity of from 2 to 8% by weight, based on a fibre fleece impregnated with a rubber latex mixture containing a heat sensitizer, a quick-acting vulcanization accelerator and, as expanding agent, a silicone oil emulsion or an inert, emulsifiable substance which is insoluble both in the rubber and the other constituents of the latex. After the impregnation of the fibre fleece, the latex mixture is coagulated by heat, vulcanized and then dried.

Abstract: A method is provided for making microporous, vapor-permeable polyurethane sheets by coagulating a polyurethane in a polar solvent with a non-solvent for the polyurethane, wherein a polyurethane polysiloxane is added to the solution of the polyurethane in the polar solvent.

Abstract: A process for producing microporous sheet materials which comprises the step of:(1) preparing a suspension in an organic solvent of a polyurethane elastomer containing polyoxyethylene segments with or without a polyurethane elastomer not containing these segments;(2) mixing the resulting organic solvent suspension with water in an amount of not less than 50% by weight based on the polyurethane elastomer in the organic solvent suspension to form a water-in-oil dispersion;(3) coating or impregnating a substrate with the resulting dispersion;(4) if desired, partially evaporating the organic solvent from the product so treated;(5) contacting the coated or impregnated substrate for a short period of time with a coagulant having a coagulation value of not more than 25%, and(6) drying the product obtained in step (5).

Abstract: A method for producing a microporous separator for an electrochemical cell comprises dissolving a copolymer of acrylonitrile into N,N-dimethylformamide, impregnating an acid- and/or alkali-resistant fibrous web with the resultant solution, and thereafter dipping the impregnated web into an aqueous coagulating bath, whereby the copolymer deposits on and between the web fibers to form a microporous matrix. The aqueous coagulating bath is selected from the group consisting of water at a temperature of 15.degree. C or below and aqueous solutions of a water-soluble acid solute, basic solute, or netural solute at a concentration of one mol / 1 or above. This method yields products having low maximum pore radii and yet low electric resistances.