Abstract: A process for preparing a flexible, low density, integral skin polyurethane foam wherein water is used as the sole blowing and density controlling agent. The process entails reacting an isocyanate component with a compound containing isocyanate reactive groups and further containing ether linkages, a polyurethane promoting catalyst, an alcohol, a surfactant, a chain extender and optional additives. The reaction is carried out at molded densities of from 15 pcf to 30 pcf in molds preheated to about 90.degree. F. to about 130.degree. F.

Abstract: Foam molding is carried out with a melt blend of polyethylene terephthalate (PET), ethylene copolymer elastomer, and glass fibers in the presence of blowing agent and with a cold mold, so that the resultant foamed article has an amorphous-rich PET surface and a crystalline PET core.

Abstract: Solutions of segmented polyurethanes are coagulated to form flat circular microporous structures having a substantially continuous pore-free surface and a substantially open pore surface.

Abstract: The specification describes and claims a method of making silicone foam compositions comprising the steps of introducing into a moulding cavity a quantity of foamable silicone compositions which is curable at room, or slightly elevated, temperature and bring about curing in the cavity to produce a cured silicone foam. The moulding cavity is closed prior to foaming thereby restricting expansion of the foam. The volume of the closed moulding cavity is a minimum 10% less than that which would be occupied by the composition if it foamed and cured at room temperature without restriction. Lower density foams formed by the above procedure may be converted into rigid elastomeric low density materials by a heat or microwave post cure. For a given composition and foam density the fire resistance of a foam produced by a method according to the invention is greater than a foam which is allowed to foam freely.

Abstract: A process for preparing polyurethane integral skin foam with low ozone depletion potential, which comprises mixing 100 pph of a polyether polyol, 5-50 pph of a chain extender, 0.1-2.0 pph of a surfactant, 0.01-0.20 pph of an amine and 0.01-0.20 pph of an organotin catalyst, 0-3.0 pph of a nucleating agent and 1.0-30 pph of a blowing agent comprising 50 to 100 weight percent of HCFC-123 and 50 to 0 weight percent of HCFC-141b to form a polyol mixture; blending said polyol mixture with isocyanate having an ISO index=0.95 to 1.10 and reacting said blend at a temperature from 0.degree.-70.degree. C. in a mold at a temperature of from 10.degree. to 90.degree. C. for a molding time of 1 to 9 minutes to form a polyurethane integral skin foam, and the product of said process.

Abstract: The present invention is directed to optionally cellular, molded polyurethane plastics having a solid surface and characterized by a content of about 0.1 to 8.0% by weight, based on the weight of the polyurethane plastic, of a polysiloxane which is chemically incorporated into the polyurethane structure.The present invention is also directed to a process for the production of these molded plastics by reacting in closed molds a reaction mixture containinga) a polyisocyanate component,b) a component containing at least one organic compound having at least two isocyanate-reactive groups and a molecular weight of 400 to about 20,000 andc) optionally a compound having at least two isocyanate-reactive groups and a molecular weight of 18 to 399,wherein a portion of component b) and/or c) contains at least one polysiloxane containing at least two isocyanate-reactive groups in an amount of about 0.1 to 8.0% by weight, based on the weight of the polyurethane plastic.

Abstract: A water absorbent, relatively dimensionally stable foam is formed from a prepolymer prepared from a polyoxyethylene containing diol, a crosslinking agent and a polyisocyanate. The preferred polyisocyanate is methylene bis(cyclohexyl isocyanate). The foam also demonstrates the ability to hold substantial amounts of water, even under pressure, and can be used in various personal and medical care products such as diapers and surgical sponges.

Abstract: A method for producing a molded product of integral-skin polyurethane foam, which comprises reacting and curing (1) a high molecular weight polyol comprising, as the main component, a polyoxyalkylene polyol having, as the main constituent, oxyalkylene groups of at least 3 carbon atoms and oxyethylene groups at its molecular terminals with the overall oxyethylene group content being not higher than 15% by weight and having a hydroxyl value of not higher than 80, (2) a crosslinking agent containing a compound having an aromatic nucleus and at least two active hydrogen-containing groups selected from the group consisting of hydroxyl groups, primary amino groups and secondary amino groups, and (3) a polyisocyanate, in a mold in the presence of a catalyst and a hydrogen atom-containing halogenated hydrocarbon foaming agent.

Abstract: Useful as catalysts for the reaction of a polyisocyanate or a partially blocked polyisocyanate with a hydroxy-containing compound are organotin compositions obtained by reacting a diorganotin oxide of the formula R.sub.2 SnO or a diorganotin dichloride of the formula R.sub.2 SnCl.sub.2 with a compound of the formula HS--CH.sub.2 CH(OH)CH.sub.2 XH where R is a C.sub.1 -C.sub.8 alkyl or an aryl group and X is --O-- or --S--.Also disclosed alre cationic electrodepositable (CED) compositions containing such catalysts.

Abstract: Useful as catalysts for the reaction of a polyisocyanate or a partially blocked polyisocyanate with a hydroxy-containing compound are organotins of the formula ##STR1## where R is a C.sub.1 -C.sub.8 alkyl or an aryl group.Y is --CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 CH(CH.sub.3)--, --CH.sub.2 CH(OH)CH.sub.2 --, or ##STR2## and X is a linking group which may be --S-- or --O--.Also disclosed are cationic electrodepositable compositions containing such catalysts.

Abstract: A polyurea elastomer is disclosed. The elastomer includes an isocyanate, an amine terminated polyoxyalkylene polyol, and a chain extender. The isocyanate is preferably a quasi-prepolymer of an isocyanate and a material selected from at least one polyol, a high molecular weight polyoxyalkyleneamine or a combination thereof. The chain extender includes a minor amount of a tetraalkylpiperazine and a major amount of diethyltoluenediamine. A one-step method of making the tetraalkylpiperazine and tetraalkylpiperazinone is also disclosed. The method includes reacting a 2-amino-2-alkyl-1-alkanol in the presence of a nickel-iron-copper-manganese catalyst.

Abstract: A process for making integral skin foams which comprises reacting into a closed mould:A) an organic polyisocyanateB) an isocyanate-reactive composition comprising:(i) a catalytically effective amount of a urethane-promoting catalyst and optionally a urea-promoting catalyst,(ii) a catalytically effective amount of a carbodiimide-promoting catalyst, and(iii) an isocyanate-reactive compound; in the presence ofC) an inert physical blowing agent.The process provides integral skin foams having good skin properties at reduced physical blowing agent levels.

Abstract: A compatibilized active hydrogen compound-alkylene glycol composition comprises components (A) a relatively high equivalent weight material having an average of at least about 1.8 active hydrogen containing groups per molecule and a weight from about 500 to about 5000 per active hydrogen containing group; (B) an alkylene glycol which is incompatible with component (A) at the relative proportions thereof present in the composition; said composition having dissolved therein: (C) a compatibilizing and catalytic amount of an additive containing (1) a urea compound and (2) a transition metal salt of a carboxylic acid wherein said metal is selected from Groups I-B, II-B, V-A, IV-B, V-B, VI-B, VII-B or VIII of the Periodic Table of the Elements; said composition containing a sufficient quantity of at least one amine group-containing material such that component (2) is soluble in said composition.

Abstract: An active hydrogen compound-alkylene glycol composition comprises components (A) a relatively high equivalent weight material having an average of at least about 1.8 active hydrogen containing groups per molecule and a weight from about 500 to about 5000 per active hydrogen containing group; (B) an alkylene glycol; and (C) a catalytic amount of at least one tin mercaptide; said composition containing at least one compound having at least one N--H containing group. Such compositions are useful in producing polyurethanes. The compositions can generally be stored without substantial loss of activity.

Abstract: The present invention relates to an integral skin rigid polyurethane foam having improved compressive strength and flexural strength. This foam is prepared by reacting a polyol resin component with an aromatic isocyanate using water as an auxiliary blowing agent.

Abstract: A process in which a blowing agent dispersion medium is used for producing poly(vinyl chloride) that is particularly well suited for use in insulation covers and the insulation covers made from the resultant poly(vinyl chloride).

Abstract: Internal mold release compositions for use in preparing molded polymeric products are disclosed which contain (a) a primary or secondary amine, (b) a carboxylic acid or amido carboxylic acid salt of a group II metal or of aluminum, lithium, copper, iron, cobalt or nickel, and optionally (c) a carboxylic acid or amido caroxylic acid.

Abstract: The present invention is directed to a process for the production of molded polyurethane foams having a compact surface and a density of at least 250 kg/m.sup.3 by the in-mold foaming of a reaction mixture containinga) a polyisocyanate component containing at least one aromatic polyisocyanate,b) an isocyanate-reactive component containing at least one organic compound having at least two isocyanate-reactive groups andc) a blowing agentat an isocyanate index of 75 to 1500, characterized in that organic carboxylic acids are used as blowing agents c), optionally in addition to other chemical or physical blowing agents.The present invention is also directed to the molded polyurethane foams obtained by this process.

Abstract: Active hydrogen-containing compositions having internal mold release components are used in a process in preparing molded polymeric products. In the process, the active hydrogen-containing composition contains (a) a primary or secondary amine, (b) a carboxylic acid or amido carboxylic acid salt of a group II metal or of aluminum, lithium, copper, iron, cobalt or nickel, and optionally (c) a carboxylic acid or amido carboxylic acid.

Abstract: The present invention is directed to composite structures by thermoplastically shaping an assembly of at least two flat thermoplastically formable plastic materials placed in layers one above the other and optionally at least one upper, lower and/or intermediate layer containing a reinforcing or filler material under such conditions of temperature and pressure that shaping is accompanied by intimate union of the individual layers of the assembly, characterized in that at least one of the flat plastic materials is based on a polyisocyanate polyaddition product having a density of at least 0.8 g/cm.sup.3 which has been prepared by the reaction of(a) aromatic polyisocyanates,(b) compounds having a molecular weight of 1800 to about 12000 and containing a statistical average of at least 2.

Abstract: Active hydrogen-containing compositions having internal mold release components for use in preparing molded polymeric products are disclosed which contain (a) a primary or secondary amine, (b) a carboxylic acid or amido carboxylic acid salt of a group II metal or of aluminum, lithium, copper, iron, cobalt or nickel, and optionally (c) a carboxylic acid or amido carboxylic acid.

Abstract: A process in which a blowing agent dispersion is used for producing poly(vinyl chloride) that is particularly well suited for use in insulation covers and the insulation covers made from the resultant poly(vinyl chloride).

Abstract: A compatabilized active hydrogen compound-alkylene glycol composition comprises components (A) a relatively high equivalent weight material having an average of at least about 1.8 active hydrogen containing groups per molecule and a weight from about 500 to about 5000 per active hydrogen containing group; (B) an alkylene glycol which is incompatible with component (A) at the relative proportions thereof present in the composition; said composition having dissolved therein; (C) a compatibilizing amount of at least one thiourea compound. Preferably the composition also contains at least one transition metal salt of a carboxylic acid wherein said metal is selected from Groups I-B, II-B, V-A, IV-B, V-B, VI-B, VII-B or VIII of the Periodic Table of the Elements. The composition preferably also contains a sufficient quantity of at least one amine group-containing material that the salt is soluble in said composition.

Abstract: The invention is a composition useful for the preparation of POWADIR membranes of a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, the composition comprising (i) a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, (ii) a solvent for such polycarbonate, and (iii) a non-solvent for such polycarbonate. The composition is useful for extruding membranes wherein the membranes formed are POWADIR membranes with a discriminating region capable of separating oxygen from nitrogen.The composition of this invention allows the formation of membranes with excellent physical properties, good separation factors for oxygen and nitrogen, with excellent fluxes.

Abstract: This invention relates to an ink impregnated material, particularly an ink roll, useful in the printing of high contrast images suitable for laser scanning. The ink roll according to the invention is a microporous polymeric structure impregnated with an ink. The ink is repetitively transferable to a surface in sufficient quantity to produce thousands of visible images. The invention further provides a method for printing a light scannable, coded image, and an apparatus therefor.

Abstract: The present invention is directed to a process for the production of compact or cellular, elastomeric moldings having a compact skin based on polyurethane urea elastomers prepared from(a) organic polyisocyanates,(b) relatively high molecular weight polyhydroxyl or polyamino compounds containing at least two reactive hydrogen atoms,(c) diaminodiphenyl ureas as chain-extending agents and optionally,(d) catalysts,(e) small quantities of ethylene glycol,(f) other chain-extending agents and/or cross-linking agents,(g) blowing agents and(h) auxiliaries and/or additives, which is characterized in that the chain-extending agents (c) are diaminodiphenyl ureas corresponding to formula I ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and represent hydrogen or a C.sub.1 -C.sub.6 alkyl radical and wherein the NH.sub.2 groups are in the m- and/or p-position to the urea group.The present invention is also directed to the RIM elastomers produced by this process.

Abstract: Internal mold release compositions for use in preparing molded polymeric products are disclosed which contain (a) a primary or secondary amine (b) a carboxylic acid or amido carboxylic acid salt of a group II metal or of aluminum, lithium, copper, iron, cobalt or nickel, and optionally (c) a carboxylic acid or amido carboxylic acid.

Abstract: The invention provides a process and apparatus for producing an injection moulding of plastics material.

Abstract: A method for making an ink-impregnated material includes steps of mixing from a plastic powder, a water-soluble salt and a water-soluble, polar organic liquid to form a mixture, heating the mixture to a temperature sufficient to melt the plastic and form a cohesive structure, leaching the salt and polar organic liquid from the structure, drying the structure, and impregnating the structure with an ink. The resulting microporous material has an open-celled network of micropores extending therethrough, which micropores have smooth, rounded internal walls free of fibrous projections. An ink roll made of this material is suitable for use in an apparatus for printing coded images such as bar codes.

Abstract: The invention relates to polyolefin foams consisting of polyolefins of ultrahigh molecular weight, i.e. weight-average molecular weight from about 4.times.10.sup.5 to 6.times.10.sup.6 g/mol and higher, and to a novel process for producing these foams by foaming a solution of a polyolefin of ultrahigh molecular weight in a solvent with the use of a physical or chemical blowing agent or of an inert gas blown into the solution, and cooling of the resulting foam to a temperature below the gelling temperature of the polyolefin. If appropriate, these foams can be provided wholly or partially with a smooth skin on their surface by superficial cooling, if appropriate under the action of pressure.

Abstract: The invention relates to integral skin rigid polyurethane structural foam having high impact strength, high heat distortion and flame retardant properties. This foam is prepared from a polyol selected from the group consisting of polyoxyalkylene polyether polyol, a polyester polyol or mixture thereof, an organic polyisocyanate, a chain extender and blowing agent.

Abstract: The present invention is directed to a process for the production of polyurethane or polyurea elastomeric molded articles according to the reaction injection molding process by reacting a polyisocyanate, a high molecular weight isocyanate reactive component and optionally a diamine chain extender, wherein the improvement is based on the use of the reaction product of a polyepoxide containing at least two epoxide groups with at least one mol of an aromatic diamine per epoxide group wherein the polyepoxide is present in an amount sufficient to provide about 0.5 to 25% by weight of the polyepoxide based on the weight of all the isocyanate reactive components. The present invention is also directed to the isocyanate reactive components for use in this process and to the molded articles produced in accordance with this process.

Abstract: Elastic molded articles having a closed surface layer are made from polyurea elastomers by the reaction injection molding technique. These polyurea elastomers are prepared from a polyisocyanate in which all of the isocyanate groups are aromatically bound, a polyether and a diamine. The polyether has at least two isocyanate-reactive groups and a molecular weight from 1800 to 12,000. At least 50% of the isocyanate-reactive groups in the polyether are pjrimary and/or secondary amino groups. The diamine has a molecular weight from 108 to 400 and primary and/or secondary aromatically bound amino groups. Known auxiliary agents and additives may also be employed.

Abstract: Elastic molded articles having a closed surface layer are made from polyurea elastomers by the reaction injection molding technique. These polyurea elastomers are prepared from a polyisocyanate in which all of the isocyanate groups are aromatically bound, a polyether and a diamine. The polyether has at least two isocyanate-reactive groups and a molecular weight from 1800 to 12,000. At least 50% of the isocyanate-reactive groups in the polyether are primary and/or secondary amino groups. The diamine has a molecular weight from 108 to 400 and primary and/or secondary aromatically bound amino groups. Known auxiliary agents and additives may also be employed.

Abstract: This invention relates to an ink impregnated material, particularly an ink roll, useful in the printing of high contrast images suitable for laser scanning. The ink roll according to the invention is a microporous polymeric structure impregnated with an ink. The ink is repetitively transferable to a surface in sufficient quantity to produce thousands of visible images. The invention further provides a method for printing a light scannable, coded image, and an apparatus therefor.

Abstract: A process for preparing a polyurethane foam handle having a woodgrain finish is disclosed, which comprises injecting a composition comprising a polyol, a polyisocyanate, a crosslinking agent, a catalyst, a foam stabilizer and a blowing agent into a mold having a shape of a handle, blowing and curing the composition and applying a woodgrain finish coating on the formed handle. In this process, a polyol comprising 50 to 100 parts by weight of a polyether polyol having at least two OH groups in the molecule and having a molecular weight of 1,000 to 10,000 and 0 to 50 parts by weight of a polymer polyol having a hydroxyl number of 20 to 50, which is formed by graft-polymerizing a vinyl compound onto a polyether polyol, is used as the polyol, and 10 to 30 parts by weight of a polyol having 2 to 4 OH groups in the molecule and having a hydroxyl number of 800 to 2,000 is used as the crosslinking agent.

Abstract: Elastomer compositions suitable for use in foaming operations and elastomeric cellular products and processes of forming such products. The elastomer compositions comprise a mixture of two thermoplastic rubber compounds, at least one of which has a vinyl aromatic component and a higher aromaticity than the other rubber compound. The compositions also contains a nucleating agent which functions when gas is entrained in the molten elastomer formulation to enhance the neutrophilic structure of the elastomer. An unstable resin is also present in the elastomer compositions. This resin is oxidized or thermally decomposed as the foamed product is cured to produce a relatively nontactified skin. Cellular elastomeric products may be formed by incorporating an inert gas into the molten elastomer compositions by the use of gas infusing equipment or by the decomposition of blowing agents. The blowing agents may be supplied to the molten elastomer compositions entrained within a plasticizing oil.

Abstract: Disclosed are internal mold release agents for the preparation of molded articles using polyisocyanate addition polymerization, which are comprised of:(A) at least one ketimine, aldimine, enamine, cyclic Schiff base or a mixture of at least two of said compounds;(B) at least one metal salt of an organic carboxylic acid having from 8 to 24 carbon atoms; and(C) optionally including at least one carboxylic acid, organic sulphonic acid, mineral acid, or amidosulphonic acid, and their use in preparing molded articles comprised of polyurethane-plastics, polyurea-plastics, polyurethane-polyurea-plastics, polyurethane-polyurea-polyamide-plastics, or polyurea-polyamide-plastics.

Abstract: The present invention is directed to a mold release composition which is a solution, liquid at room temperature, of(A) at least one zinc salt of a straight chain or branched, saturated or unsaturated aliphatic carboxylic acid containing 8 to 24 carbon atoms in(B) at least one organic compound containing nitrogen which is liquid at room temperature, the solution containing the zinc salt in a quantity of about 10 to 75% by weight, based on the total weight of the composition.The present invention is additionally directed to an isocyanate reactive mixture containing isocyanate reactive compounds and the above described mold release composition. The present invention is further directed to a process for the preparation of molded products based on the above mixture and to the molded products obtained according to this process.

Abstract: Molded polyurea foam parts having densities of from 200 to 600 kg/m.sup.3 and a compact skin are made by reacting a polyisocyanate component with a polyamine component in a closed mold at an isocyanate index of from 70 to 130. The polyamine component generally includes (1) an aminopolyether having a molecular weight of from 1800 to 12,000 and 2 to 3 isocyanate reactive groups of which at least 90% are aromatically bound primary and/or secondary amino groups, (2) an aromatic diamine, (3) a foaming agent and optionally (4) known auxiliaries and additives. The polyisocyanate component includes any aromatic di- and/or poly-isocyanate. Parts produced by this process have excellent mechanical properties and a well-defined solid skin.

Abstract: A propellant is mixed with unsaturated polyester inside a first space (A) at a first pressure, for example at the atmospheric pressure. The polyester is then sprayed on the whole or parts of an open or exposed mould which is applied in a low-pressure chamber having a powerful negative pressure of 60-95% vacuum. In order to spray a first layer, polyester having a first amount of propellant is sprayed on the mould. At the initiation the propellant causes a powerful foaming effect at which bubbles are created and/or expanded in the polyester. In order to spray a second layer, which can be applied before or after the first layer, polyester having a second amount of propellant, or is without propellant, is sprayed on the mould, which causes fewer bubbles or no bubbles at all. The resulting polyester which comprises formed and expanded bubbles is bound (is allowed to tack rigid shape/is polymerized) by the use of a short tack-free time in the low pressure, said short time being preferably 5-10 minutes.

Abstract: A microporous biocompatible material is formed by preparing a segmented polyether urethane urea solution containing 25%.+-.1.5% solids dissolved in a solvent. The solution has sufficient viscosity to be preshaped and formed into the desired thickness of the finished article, then immediately immersed into a precipitation bath in which the solvent in the solution is miscible for a time interval sufficient to cause the solution to set up into an opaque elastomeric article. The article is immediately removed from the bath, any excess solvent extracted and then dried at a temperature on the order of 35.degree. C. to 70.degree. C. followed by heat treating by annealing for approximately sixty minutes at a temperature at 100.degree. C. to 130.degree. C. The void volume of the membrane solution is controlled to within the 50% to 80% range and the pore size from ca <0.1 to several mms.

Abstract: Amine catalysts useful for producing polyurethane foams coated with skin by reaction of an organic polyisocyanate with a polyol. The catalysts comprise 4-methyl-1-(2-hydroxyalkyl)-piperazine, and emit no bad odor, give excellent moldability and are free from deterioration of skin and discoloration of covering materials.

Abstract: There is disclosed a polyurethane foam of the rigid type having three different types of polyol components capable of having suspended therein fillers and reinforcing fibers. The foam is made into boards and the like and has continuous fiber glass strands or yarn disposed longitudinally in or adjacent the surface skin of the foam. The strands or yarn are parallel and close together and are flattened out in the foam-forming process so that the surfaces have a continuous fiber glass implant longitudinally and substantially so transversely.

Abstract: Elastomer compositions suitable for use in foaming operations and elastomeric cellular products and processes of forming such products. The elastomer compositions comprise a mixture of two thermoplastic rubber compounds, at least one of which has a vinyl aromatic component and a higher aromaticity than the other rubber compound. The compositions also contains a nucleating agent which functions when gas is entrained in the molten elastomer formulation to enhance the neutrophilic structure of the elastomer. An unstable resin is also present in the elastomer compositions. This resin is oxidized or thermally decomposed as the foamed product is cured to produce a relatively nontactified skin. Cellular elastomeric products may be formed by incorporating an inert gas into the molten elastomer compositions by the use of gas infusing equipment or by the decomposition of blowing agents. The blowing agents may be supplied to the molten elastomer composition entrained within a plasticizing oil.

Abstract: This invention relates to the production of polymer-coated, finely divided polyisocyanates by mixing(A) solid, finely divided polyisocyanates (preferably dimeric diisocyanates or urea diisocyanates) with(B) polyisocyanates differing in composition from those mentioned under (A) (preferably (cyclo) aliphatic polyisocyanates, such as biuretized diisocyanates or trimers or NCO-prepolymers),in quantities of from 0.05 to 50 parts by weight, and preferably in quantities of from 0.2 to 25 parts by weight, of (B) per 100 parts by weight of (A). The solid polyisocyanate particles surface-modified by covering with polyisocyanates (B) and then reacted with(D) isocyanate-reactive compounds containing reactive hydrogen atoms or with compounds free from active hydrogen atoms which form polymers with isocyanates in sub-equivalent to substantially equivalent quantities (preferably 0.5 to 1.

Abstract: A composite hollow fiber type separation membrane which has three layers comprising a selective separation layer, an ultra-microporous layer and a porous layer, said selective separation layer, said ultra-microporous layer, said porous layer being arranged in said order commencing from the inner surface of said hollow fiber membrane;wherein said selective separation layer is formed on said ultra-microporous layer without penetrating into said ultra-microporous layer and has a non-porous, dense structure, the average thickness of said layer being 0.01-2.mu., and the coefficient of variation in thickness thereof being less than or equal to 25%;wherein said ultra-microporous layer has a surface in which the presence of pores cannot be confirmed by 24,000 .times. scanning electron microscopy, but which has a fluid permeability at least 10 times that of said selective separation layer, the thickness of said layer being less than or equal to 0.08.mu.

Abstract: A method for providing anisotropic polymer membranes from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.

Abstract: The present invention relates to a process for the production of polyurethane-urea or polyurea-based microcellular of foam moldings by reacting a polyisocyanate component containing aromatically bound isocyanate groups with an isocyanate-reactive component containing at least one compound which has at least three aliphatic ether groups and aliphatically bound isocyanate-reactive groups and wherein a portion of the aliphatically bound-reactive groups are amino groups which have been converted to ammonium carbamate, carbonate or bicarbonate groups.The present invention also relates to the compounds containing aliphatic ether groups and ammonium carbamate, carbonate or bicarbonate groups, optionally in admixture with compounds containing unmodified amino groups or other known isocyanate-reactive compounds.

Abstract: The invention relates to a process for the preparation of cellular, microcellular and noncellular polyurethane polyurea molded parts through the reaction of organic polyisocyanates, polyols having at least 2 reactive hydrogen atoms, and a chain extender containing at least 70 percent by weight of a mixture of aromatic diamines comprising from 80 to 50 weight percent of at least one primary aromatic diamine whose amino groups are sterically hindered relative to reaction with polyisocyanates, and 20 to 50 weight percent of at least one unsubstituted or substituted reactive primary aromatic diamine whose amino groups do not exhibit reduced reactivity to polyisocyanates.These reactive mixtures produce polyurethane polyurea polymers with excellent demoldability without the use of external mold release agents.