Abstract: A method for extruding polyvinyl alcohol which includesadding sufficient energy to the polyvinyl alcohol to both melt it and essentially eliminate the crystallinity in the melt, andsimultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol andrapidly cooling the extruded melt reduces the heat history and improves the resulting color of the extrudable polyvinyl alcohol.

Abstract: Polyvinyl alcohol films are provided which are gelled, non-tacky, bubble-free and resistant to water at ambient temperatures. The polyvinyl alcohol film is obtained by plasticizing (fluxing) and melting granules of pure polyvinyl alcohol containing from 25 to 35% by weight of water at a temperature at least 100.degree. C. above the equilibrium melting point of the granules and less than or equal to 220.degree. C., and extruding the melted granules through a die at a temperature at least 5.degree. C. above the equilibrium melting point of the granules and less than or equal to 98.degree. C., optionally followed by monoaxial stretching or biaxial stretching of the unstretched film obtained. The stretched or unstretched film may be heat-treated to improve its properties. The polyvinyl alcohol film can be used to prepare with thermoplastic films composite films or sheets having a high gas impermeability.

Abstract: A high tenacity, high intitial modulus polyvinyl alcohol fiber showing a high level of crystalline heat of fusion, characterized in that the fiber is made of polyvinyl alcohol having a degree of polymerization of not less than 1,500, has a tenacity of not less than 17 g/d and an initial modulus of elasticity of not less than 400 g/d and shows a crystalline heat of fusion of not less than 29 cal/g, and a method of producing said polyvinyl alcohol fiber comprising:(i) dissolving polyvinyl alcohol with a degree of polymerization of not less than 1,500 in a solvent capable of giving a 5 wt % polyvinyl alcohol solution and the solvent is further characterized in that the nuclear magnetic resonance spectrum measured at 50.degree. C. after storage of the solution at 50.degree. C. for 96 hours following preparation thereof is substantially identical with that measured at 50.degree. C.

Abstract: Rapidly shrinking fibers hardly soluble in water and capable of shrinking in water at 20.degree. C. by not less than 30% in not longer than 10 seconds are obtained, for example, by spinning, drawing and heat-treating a carboxy-modified polyvinyl alcohol under specific conditions. Yarns made from a fiber of this kind in conjunction with a fiber slowing shrinking in water as well as nonwoven fabrics made by incorporating yarns containing said rapidly shrinking fibers in nonwoven fabric shrinkable upon absorption of water are suited as means of tightly fitting edge portions of disposable diapers to the thigh.

Abstract: In a process for preparing a polyvinyl alcohol yarn of high tenacity, a solution of polyvinyl alcohol in an organic solvent is extruded from a spinneret into a coagulation bath through an air gap or inert gas gap, and the extruded solution is drawn. The spinneret has capillaries which are at least five times their diameter in length and the concentration of the polyvinyl solution is at least 30-(M.sub.v /20,000) in percent by weight of the polyvinyl alcohol solution.

Abstract: The clamp includes a member having an anvil at one end and a threaded bore at another end with a longitudinal bore axis directed at the anvil. A rod having a threads and a longitudinal splines is threadingly disposed within the threaded bore. The rod has a first end, preferably with a handle, and a second end, preferably with a shoe, facing the anvil. A gear matingly engageable with the splines on the rod is rotatably held to the member by a fastener through a central bore. The gear intertwines with the splines on the rod, such that movement of the gear in one direction rotates the rod in an to threadingly move the rod through the bore along the longitudinal axis of the rod. A second embodiment of the clamp includes a member having an anvil at one end and a bore at another end with a longitudinal bore axis directed at the anvil. A rod having a plurality of threads and a pair of longitudinally extending, generally smooth surfaces is disposed within the bore.

Abstract: Polyvinyl alcohol films are provided which are gelled, non-tacky, bubble-free and resistant to water at ambient temperatures. The polyvinyl alcohol film is obtained by plasticizing (fluxing) and melting granules of pure polyvinyl alcohol containing from 25 to 35% by weight of water at a temperature at least 100.degree. C. above the equilibrium melting point of the granules and less than or equal to 220.degree. C., and extruding the melted granules through a die at a temperature at least 5.degree. C. above the equilibrium melting point of the granules and less than or equal to 98.degree. C., optionally followed by monoaxial stretching or biaxial stretching of the unstretched film obtained. The stretched or unstretched film may be heat-treated to improve its properties. The polyvinyl alcohol film can be used to prepare with thermoplastic films composite films or sheets having a high gas impermeability.

Abstract: Solutions of polyvinyl alcohol in non-aqueous mixtures of dimethyl sulfoxide and up to about 30 weight percent, based on said mixture, of an alcohol containing from 1 to about 4 carbon atoms can be converted to hydrogels, fibers and other useful products.

Abstract: Molecularly oriented films are produced which comprise a layer containing a blend of EVOH and nylon. The films exhibit a desirable balance of oxygen barrier and strength properties, and are ideally suited for many packaging applications.

Abstract: This invention relates to a process for extruding scrap material comprising polyvinyl alcohol, polypropylene-polyvinyl alcohol adhesive and polypropylene prepared with a high activity polymerization catalyst, the improvement comprising utilizing in the polypropylene from about 50 to about 5000 ppm of hydrotalcite.

Abstract: Polyvinyl alcohol articles of high strength and modulus are obtained by thermoreversible gelation of a polyvinyl alcohol solution, extraction of the gelation solvent using a mixture of a low alcohol or ketone and water, followed by high stretching. Preferably, a mixture of 5-80 vol. % of acetone and 95-20 vol. % of water is used as extractant. With this process extraction times of only 3-10 minutes are required.

Abstract: Processes for producing semipermeable membranes in the form of hollow fibers are disclosed including extruding a solution of a block copolymer including at least one hydrophilic polymer and at least one hydrophobic polymer while simultaneously injecting a gaseous or vaporous center medium into the center bore of the hollow fiber extrudate, including coagulating the extrudate so formed therefrom. The preferred process includes using air or the components of air as the center medium and employing a polyethyleneoxide-polycarbonate block copolymer to form the hollow fiber membranes.

Abstract: High modulus and high strength articles of polyvinylalcohol are obtained by thermoreversible gelation of a 5-50 wt. % solution of a polyvinylalcohol with an M.sub.W of 2.5.times.10.sup.4 to 5.times.10.sup.5 in water, followed by solvent removal and high stretching.Pref. gelation is obtained by cooling to a temperature of at least 40.degree. C. below the gelation temperature.With this process low costs of solvent removal and regeneration are obtained.

Abstract: High strength and modulus fibers are prepared from a poly(vinyl alcohol) solution in a mixed solvent consisting of water and water-miscible organic solvent. Upon extruding the poly(vinyl alcohol) solution into a coagulation bath, gel fibers are formed as a consequence of favorable gel structure with homogeneous net-works. Drawing the gel fibers to an exceedingly high degree leads to formation of poly(vinyl alcohol) fibers which have a superhigh tensile strength and a superhigh modulus.

Abstract: A process for preparing improved pellets of a hydrolyzed ethylene-vinyl acetate copolymer which comprises extruding a methanol or a water-methanol solution including a hydrolyzed ethylene-vinyl acetate copolymer and a lubricant into a coagulating liquid in the form of a strand and cutting the strand into pellets. According to the process of the present invention, the molding processability can be improved without damaging the properties of the molded articles.

Abstract: Gas separation membranes comprising an inorganic compound-organic polymer blend may be prepared by admixing an organic polymer such as poly(vinyl alcohol) with a phosphoric acid or sulfuric acid in a mutually miscible solvent. After allowing the mixture to proceed for a period of time sufficient to form a blend, the solution may be cast on an appropriate casting surface and, after the solvent has been evaporated, the desired membrane which may have a thickness of from about 0.1 to about 100 microns, is recovered.

Abstract: An ultra-high-tenacity multifilament fiber of polyvinyl alcohol having a degree of polymerization of at least 1500, said filament having a tensile strength of at least 12 g/d and an initial modulus greater than 280 g/d, which is produced by a process for producing an ultra-high-tenacity polyvinyl alcohol fiber which comprises the steps of dissolving polyvinyl alcohol having a degree of polymerization of at least 1500 in a solvent, dry-spinning the resulting polymer solution through a spinneret into an environment of air or inert gas, introducing the dry-spun filaments into a coagulating bath, and drawing the coagulated filaments at a total effective draw ratio of at least 20 times.

Abstract: A fine-denier, high-tenacity, water-resistant polyvinyl alcohol fiber is produced by dissolving a polyvinyl alcohol having an average degree of polymerization between 1,200 and 3,000, boric acid or a salt thereof in a proportion of 0.5 to 5 weight percent relative to said polyvinyl alcohol and an acid for adjusting a final spinning solution to pH 5 or less in water to prepare an aqueous solution containing 8 to 14 weight percent of said polyvinyl alcohol, discharging said aqueous solution as said spinning dope from a spinneret nozzle having an average orifice diameter of 0.02 to 0.04 millimeters into a bath comprising an aqueous solution containing alkali and dehydrating salt at a bath draft within a range of 10 to -60 percent, and finally stretching the resulting tow at least 10-fold. The fine-denier fiber thus obtained has a marked reinforcing effect on various materials, particularly inorganic hydraulic materials such as cement.

Abstract: Polymer blend membranes which possess increased structural strength may be fabricated by preparing a polymer blend membrane comprising a mixture of a phosphoric acid or sulfuric acid and an organic polymer which is at least partially compatible therewith dissolved in a mutually miscible solvent. The resulting polymer blend membrane is then cast upon a porous solid support such as a glass cloth, polysulfone or ceramic and the solvent is allowed to evaporate.

Abstract: Disclosed is a process for the formation of olefin-vinyl alcohol copolymer pellets which comprises mixing particles of the copolymer with water to obtain a wet cake containing about 20-70% solids by weight to thereby obtain a plasticized mass of the copolymer, thereafter extruding the copolymer at a temperature of about 5.degree.-7.degree. C. below the melting point of the mass through a nozzle to form a rod, and dividing the rod into individual pellets.

Abstract: In a process for producing fiber-reinforced hydraulically setting extruding materials, the process which comprises, not adding the reinforcing fiber in the form of single fibers to the starting materials, but employing it as collected yarns by collecting the single fibers with a collecting agent, uniformly dispersing them in the starting materials, then releasing the collected condition of said dispersed collected yarns and splitting into single fibers by swelling and dissolution of the collecting agent and by the shear force by a screw etc., thereby the dispersion is improved.The single fibers having a great aspect ratio which have been released from the collected condtion are uniformly dispersed in the extruding material, and a remarkable reinforcing effect is obtained.

Abstract: A sheet-like structure is produced from a vinyl alcohol polymer by a method wherein, in a self-cleaning multi-screw extruder, the polymer is mixed with a small amount of water, the mixture is melted, homogenized, devolatilized and finally extruded as a melt, and the extrudate is shaped in a conventional manner into the sheet-like structure.

Abstract: The invention disclosed herein provides a process for the high temperature extrusion of polyvinyl alcohol monofilament soluble in water comprising the steps of blending from about 80 to 98 percent by weight polyvinyl alcohol resin having a number average molecular weight of from about 10,000 to 200,000 and a degree of hydrolysis of from about 85 to 91 percent with from about 20 to 2 percent by weight of a plasticizer selected from the group consisting of hydroxyethers, diols, triols and other polyols and mixtures thereof, reducing the moisture content of the resin to a level of less than about one percent and the volatile content thereof to a level of less than about two percent and, melt extruding the blend to form monofilaments.

Abstract: Polyvinyl alcohol of molecular weight over 500,000 (i.e. 1,500,000 to 2,500,000) is spun as a dilute solution (2-15%) in a relatively non-volatile solvent such as glycerin. The resultant gel fiber is extracted with a volatile solvent such as methanol and dried. Upon stretching at one or more stages during the process, fibers of tenacity above 10 g/denier and modulus above 200 g/denier (e.g. 18 and 450, respectively) are produced.

Abstract: A process of preparing film, fibers and other shaped articles by nitrosating a polyhydroxy polymer in a reaction medium containing a solubilizing agent for the resulting polyhydroxy polymer nitrite ester and a suitable proton acceptor, bringing the reaction mixture into the desired shape and regenerating and separating the polyhydroxy polymer by contact with a protic solvent in the presence of an acid catalyst. The polyhydroxy polymer may be a polyvinyl alcohol, cellulose or other polysaccharide, and mixtures thereof. Also dissolved in the reaction medium may be an organic solvent soluble polymer substantially lacking hydroxyl groups. If mixtures of polyhydroxy polymers or of polyhydroxy polymers lacking hydroxyl groups and organic solvent soluble polymers are employed the resulting films, fibers or other shaped articles consist of homogeneous and intimate mixtures of all the polymers originally present in solution.

Abstract: There is provided a hollow fiber membrane of ethylene-vinyl alcohol copolymer which is produced by a process comprising extruding a spinning solution of an ethylene-vinyl alcohol copolymer in a solvent selected from the group consisting of dimethylsulfoxide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone and mixtures thereof through a hollow fiber spinneret while a liquid coagulant is introduced into a central aperture of said spinneret, passing the spun fiber through a gaseous atmosphere in a manner such that the fiber is drawn 0.5 to 20 times its extrusion rate and then coagulating said fiber in a coagulating bath at a temperature within the range satisfying the following relationship:when 15.ltoreq.C.ltoreq.40, 1/4C+20.ltoreq.T.ltoreq.1/4C+57wherein C denotes the copolymer concentration of the spinning solution (wt. %) and T denotes the coagulation temperature (.degree.C.).

Abstract: A hollow fiber membrane made of an ethylene-vinyl alcohol copolymer is provided, which is characterized in that, when observed in a dry state with an electron microscope, the hollow fiber membrane has at least one dense, active layer (or skin layer) on the inside and/or outside surface thereof and further a three-layered structure comprising two layers respectively contacting the inside and outside surfaces and each consisting of a plurality of particles bonded together and having particle sizes of 0.01 to 2 microns and a substantially particle-free homogeneous layer lying between the two layers.

Abstract: A fibre and method of making the fibre. The fibre consists at least in part of a cationic amino-formaldehyde resin and may also include a carrier material which is a water-soluble fibre-forming polymer.Fibres can be made by a wet-spinning method. An aqueous solution of the resin is mixed with an aqueous solution of polyvinyl alcohol to form a spinning solution and the spinning solution is extruded into a coagulation bath to form a fibre, which is dried and cured.The cationic amino-formaldehyde resin comprises the reaction product of a triazine, optionally urea, and formaldehyde and a compound, such as di- or tri-ethanolamine to render the resin cationic. It may be mixed with another cationic amino-formaldehyde resin, e.g. a cationic urea-formaldehyde resin, in the making of the fibre.

Abstract: Aqueous dispersions of olefin resins having a low film-forming temperature can be continuously produced by homogeneously mixing a mixture composed of olefin resin, partially saponified polyvinyl alcohol and water by means of an extruder having a multi-screw, and extruding the resulting dispersion.If partially saponified polyvinyl alcohol in which residual acetic acid groups are blocked is used, the film-forming temperature thereof is effectively lowered.

Abstract: Superfine fibers of polyvinyl alcohol type having a single fiber diameter of 0.1-1.0.mu. and a fineness of 0.8-80.times.10.sup.-4 d/f are baked in the presence of a dehydration catalyst so that the weight loss ratio of fibers falls under the range of about 5 to 40%.When ion-exchange radicals are introduced into the partially dehydrated fiber, superfine fibers with a high ion-exchange rate are obtained.

Abstract: There is disclosed a new process for preparing coupled and coextruded multilayer articles (consisting of two or more layers) made of thermoplastic materials, and closed-surface bodies comprising the same.

Abstract: A multi-layer film having a crosslinked layer of an olefin vinyl alcohol copolymer is produced by providing a substrate layer and a layer of a copolymer of an olefin and a vinyl ester. The multi-layer structure is crosslinked preferably by irradiation and then hydrolyzed to convert the olefin/vinyl ester copolymer into a copolymer of the olefin and vinyl alcohol. The thus produced structure may be incorporated into a further film combination by extrusion coating additional layers. The multi-layer structure may be oriented to produce a heat shrinkable film for use as a packaging material.

Abstract: A leather-like sheet material bearing a remarkable resemblance to high-quality leathers of natural origin, especially in respect of flatness, bending crimp, grain and feeling, is produced by providing a substrate consisting of a fibrous base material and a porous coating layer with a thin layer of a polymer, subjecting the surface to a specific heat treatment, providing the resulting material with another thin layer of a polymer, and, if desired, embossing the material.

Abstract: Films, 0.5-10 mils thick, which are rapidly and completely soluble in cold water, and which are suitable for use as packaging film in automatic packaging equipment, can be prepared by conventional melt extrusion processes when prepared from a novel composition consisting essentially of 5-20 parts by weight of a polyethylene glycol (having an average molecular weight in the range between 325 and 550) in 100 parts by weight of a partially hydrolyzed low molecular weight polyvinyl alcohol.

Abstract: In a typical tubular extrusion of hydrolyzed ethylene-vinyl acetate copolymer having an ethylene content of 15 to 50% by mole and a degree of hydrolysis in the vinyl acetate units of not less than 90% by mole, an improved process for preparing the tubular film without wrinkle by controlling the surface temperature of the tubular film at the nip rolls within the range of 50.degree. to 100.degree. C.

Abstract: A flame-retardant fiber is made comprising 20 - 95% by weight of amino resin condensate of an amino compound and formaldehyde in which the amino compound may be a melamine, combined melamine and guanamine, combined melamine and urea, combined melamine, guanamine and urea, and benzoguanamine and/or urea, and in which the chemical bond linking the polymer chain is for the most part methylene linkage and 80 - 5% by weight of polyvinylalcohol, the resulting fiber being cured when necessary and having a tensile strength of at least 1.0 g/d., and having a break elongation of at least 5%.

Abstract: A PVA film successively oriented in two orthogonal directions is prepared by firstly elongating the film in the longitudinal direction by more than 200% while maintaining the water content (Z .times. 100)% at a value of from 10 to 35% and the temperature in a range of from (1.50/Z +20).degree. C to 75.degree. C. The film is then preheated while maintaining its water content at least 7%, and then elongated laterally by more than 200% at a temperature of from 45.degree. to 110.degree. C. Then the film is heat treated at a temperature of 110.degree. to 210.degree. C while permitting the film to shrink by less than 15% in the lateral direction. Finally, the film is cooled to room temperature under tension.

Abstract: A flame retardant composition comprises an organic polymer containing one of the inorganic compounds with phosphorus and nitrogen, or either of them in the form of finely powdered crystal. The inorganic compounds are coated with an inactive material.

Abstract: Shaped articles comprised of PVA and PVC having improved flame-retardancy and resistance to discoloration resulting from heat treatment are provided by the incorporation therein of calcined stannic acid, characterized by a specific crystal size.

Abstract: A dialysis membrane comprising a plurality of polyvinyl alcohol hollow fibers of substantially homogeneous structure having a degree of orientation (.pi.) in the range of 60% .ltoreq. .pi. .ltoreq. 98% and a degree of swelling (.zeta.) in the range of 1.05 .ltoreq. .pi. .ltoreq. 1.80 times.

Abstract: Disclosed is a method for preparing polyvinyl alcohol fibers which comprises spinning an aqueous solution of polyvinyl alcohol containing boric acid or a borate and from about 0.01-5 weight per cent based on said polyvinyl alcohol of an additive comprising an amino acid, an amine, salicylic acid and derivatives thereof or a derivative of pyridine into an alkaline coagulation bath, and subsequently treating the resultant spun fiber by roller drawing, neutralizing with acid, wet hot drawing, washing with water, drying and dry hot drawing.

Abstract: Method for preparing a biaxially oriented polyvinyl alcohol film by extruding a mixture of polyvinyl alcohol and water, and if desired, incorporated with a polyhydric alcohol, in a tubular form, drying the tubular film to give a tubular non-stretched film having a degree of crystallization of not more than 44 % and a water content of not more than 20 % by weight, and biaxially stretching the non-stretched film at a stretching ratio of not less than 2 in each of the machine and transverse directions by means of inflation under conditions such that the film surface at the starting point of stretching is maintained at a temperature in the range from about 60.degree. to about 150.degree.C., the surface of the film reaching a maximum temperature at the middle portion of a stretching zone extending from said starting point to a point where the tube reaches a maximum diameter and the difference between maximum and minimum surface temperatures in the stretching zone does not vary more than about 15.degree.C.

Abstract: New polymeric materials in the form of fibers and films composed of polyvinyl alcohol, polyvinyl chloride and a water-soluble amido-polymer having a portion of the polyvinyl chloride grafted thereon and which contains at least about 80 mole percent amido or methylolated amido groups. These materials possess excellent light and heat resistance.Also disclosed is a process for preparing these materials comprising adding a water-soluble catalyst and emulsifier to an aqueous solution of the amido-polymer and subjecting the mixture to emulsion polymerization with added vinyl chloride. Thereafter, polyvinyl alcohol is added as a matrix to the emulsion to make a dope which is then coagulated.CROSS REFERENCE TO RELATED APPLICATIONSThis application is a division of application Ser. No. 348,069, filed Apr. 5, 1973, now U.S. Pat. No. 3,887,676, which in turn was a continuation-in-part of application Ser. No. 230,478, filed on Feb. 29, 1972, and now abandoned, which in turn was a continuation of application Ser. No.

Abstract: Method for producing a synthetic fiber substantially comprising dissolving a composition consisting essentially of:A. 5-40 percent by weight of a copolymer consisting ofA. 20-80 percent by weight of polyvinyl alcohol, andB. 80-20 percent by weight of acrylonitrile, andB. 60-95 percent by weight of a copolymer consisting ofC. 55-95 percent by weight of styrene, andD. 5-45 percent by weight of acrylonitrile, in dimethyl sulfoxide or dimethyl acetamide as a solvent, and wet-spinningThis fiber is used for producing paper and has a potentially fibrillar texture. When beaten, it forms a synthetic pulp having stalk fibrils and micro fibrils extending from the stalk fibrils.High-tenacity synthetic paper can be made because this synthetic pulp is self-adhesive.

Abstract: A method for producing fibers and films comprising emulsion polymerizing a polyvinyl alcohol derivative having sulfone or sulfate group with a chlorine-containing vinyl monomer, adding the thus formed emulsion to a matrix of polyvinyl alcohol and then coagulating the mixture into a film or fiber. The resulting polymeric compositions are composed of polyvinyl alcohol, the sulfone or sulfate-containing polyvinyl alcohol and the chlorine containing vinyl polymer, in which a part of the chlorine-containing vinyl polymer is grafted onto the polyvinyl alcohol derivative. The emulsions used possess excellent stability and the films and fibers therefrom possess excellent heat resistance.

Abstract: A polyelectrolyte composite of polyvinyl alcohol derivatives; which comprises: an ionically bonded composite of a partial acetal of polyvinyl alcohol modified with diethoxyethyl trimethyl ammonium ion or a partial aminoacetal of polyvinyl alcohol modified with aminoacetal, with a carboxymethyl polyvinyl alcohol or a partial sulfate of polyvinyl alcohol.

Abstract: A process for preparing a shaped article made of hydrolyzed ethylene-vinyl acetate copolymer having an improved impact resistance by conditioning the shaped article to contain water within the range of 0.2 to 3.0 % by weight to the article. The impact resistance of the shaped article can be improved without losing the advantageous characteristics of the copolymer and the improved article can be suitably employed as engineering plastics.

Abstract: Shaped articles of polyvinyl alcohol are prepared by saponifying a liquid feed of polyvinyl ester as it cascades downwardly along the walls of a cylindrical reactor, and by taking-up from the reactor outlet the fibrous, shaped article of oriented, solid polyvinyl alcohol thus formed at a rate of at least 50 cm/minute. Advantageously, the thus formed shaped article is next divided into sliver, stretched and cut into fibers and, optionally, beaten, which fibers are useful in the manufacture of paper-like sheet materials.