摘要:
A process for improving the water vapor permeability of polyurethane coatings by incorporating a hydroxy alkyl amine, an alkoxylated amine or the salt of either with an inorganic or organic acid into the coating composition is taught. Coating compositions including this water vapor diffusion enhancing additive are also taught as is a process for coating water vapor permeable substrates.
摘要:
There is described a polyurethane anionomer which is particularly suitable as a textile sizing agent because it is water-soluble and sufficiently hydrolysis-resistant to be recoverable by ultra-filtration. It is superior to previously known ionomers in being hard, tough and having a smooth surface.This anionomer is produced by reacting organic diisocyanates with tri- or tetra-ethylene glycol and optionally other aliphatic glycols as well as glycols bearing carboxyl, carboxylate, sulphonic acid or sulphonate groups in selected ratios which render the anionomer water-soluble after neutralization of an appropriate amount of the carboxyl or sulphonic acid groups. Aqueous solutions can be formed by dissolving the solid anionomer in water and these solutions can be used to size textile fibers with the recovery of excess anionomer by ulra-filtration.
摘要:
Novel linear hydrophilic polyurethane polymers are presented. The polymers provide outstanding soil-release, anti-soil redeposition and anti-static properties when applied to natural and synthetic textile substrates, especially textile substrates containing polyester fibers. These polyurethanes are particularly useful in detergent compositions.
摘要:
The wetting rates of polyurethane hydrogels comprising lightly crosslinked polymers of isocyanate terminated prepolymers which are the reaction product of (i) poly(alkyleneoxy) polyols with (ii) organic diisocyanates that has been lightly crosslinked with (iii) water or an organic polyamine are enhanced by treating the surface of the solid hydrogel with certain ketones, alcohols, organic amines, aromatic hydrocarbons or aqueous alkali metal hydroxide solutions.
摘要:
Water soluble, high solids urethane coating compositions comprising a polycaprolactone derivative, an aliphatic polyisocyanate and water. The polycaprolactone derivative is a water soluble, carboxyl modified oligomer addition reaction product mixture obtained by the reaction of polycaprolactone polyol and an anhydride of a polycarboxylic acid to produce a water insoluble adduct that on reaction with an inorganic or organic base produces the water soluble, carboxyl modified oligomer addition reaction product mixtures which are eminently suitable for the production of urethane coating compositions of this invention. The polycaprolactone polyol reacted with the polycarboxylic acid has an average at least two hydroxyl groups in the molecule, a hydroxyl number of from about 15 to about 600 and an average molecular weight of from about 290 to about 6,000. The carboxylic acid anhydride has at least one intramolecular carboxylic anhydride group.
摘要:
A substrate is coated with a polyvinylpyrrolidone-polyurethane interpolymer. In the method, a polyisocyanate and a polyurethane in a solvent such as methyl ethyl ketone are applied to a substrate and the solvent evaporated. If the substrate is a polyurethane, only the polyisocyanate need be employed. Polyvinylpyrrolidone in a solvent is then applied to the treated substrate and the solvent evaporated. The invention is applied, for example, to a tube such as a catheter, a condom and a peristaltic pump tube.
摘要:
A hydrophilic and thermoreactive urethane composition having improved properties such as stability in solution, non-tackiness, water resistance and strength and useful in treating and finishing fibrous products prepared by forming a urethane prepolymer containing free isocyanate groups from (a) (1) a compound containing at least 2 active hydrogen atoms, containing an oxyethylene chain, and having a molecular weight of about 200 to 20,000, or (2) a compound containing at least 2 active hydrogen atoms, not containing an oxyethylene chain, and having a molecular weight of about 200 to 20,000 and a compound containing at least 2 active hydrogen atoms, containing an oxyethylene chain and having a molecular weight of about 200 to 200,000; and (b) an excess of a polyisocyanate; and if desired, (c) a chain extender containing at least 2 active hydrogen atoms; whereby the prepolymer has an oxyethylene chain content of 10 to 40% by weight, and then reacting the prepolymer or a solution thereof with not more than 3 times the equivalent of the free isocyanate groups in the prepolymer of an aqueous solution of a bisulfite salt having a concentration of at least 15% by weight. Where the urethane prepolymer contains at least 1% by weight ester groups, the hydrophilic and thermoreactive urethane composition is particularly valuable as a high strength adhesive composition and is useful as an adhesive in bonding a sheet-like material as a top-coat to a fabric as a base in producing an artificial leather.
摘要:
Fast curing surgical adhesives and sealants contain an NCO-terminated hydrophilic urethane prepolymer derived from an aromatic diisocyanate and a polyol. Substantially all the aromatic diisocyanate used to prepare the NCO-terminated hydrophilic urethane prepolymer is in the para form. Optionally, the aromatic diisocyanate is substituted with at least one electron withdrawing group, such as, for example, a fluorine group.