Reduced solvent process for preparation of aqueous polyurethane dispersions with improved heat and solvent resistance

• Main Authors: SONJA STAMMLER, YOULU DUAN
• Format: Patent
• Language: English
• Published: 11.03.1999
• Edition: 6
• Subjects: ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; ADHESIVES; BEER; BIOCHEMISTRY; CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; COMPOSITIONS OR TEST PAPERS THEREFOR; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL ORENZYMOLOGICAL PROCESSES; DYES; ENZYMOLOGY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; MEASURING; MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEICACIDS OR MICROORGANISMS; METALLURGY; MICROBIOLOGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; MUTATION OR GENETIC ENGINEERING; NATURAL RESINS; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PHYSICS; POLISHES; PROCESSES OF PREPARING SUCH COMPOSITIONS; SPIRITS; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TESTING; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF MATERIALS AS ADHESIVES; VINEGAR; WINE

A process for preparing poly(urethane/urea) prepolymers and aqueous poly(urethane/urea) dispersions (PUDs) therefrom, the poly(urethane/urea) polymers having high heat resistance and good water resistance. The method employs a water soluble volatile organic solvent, such as acetone, at a level of 0.1-5%, based on final dispersion weight, a level which does not require removal for purposes of flash point considerations. The method includes the steps of reacting in the presence of a water soluble volatile organic solvent at a level corresponding to no more than 5% by weight of the final dispersion, a polyisocyanate component comprising a diisocyanate, with a polyol component to produce an isocyanate terminated polyurethane prepolymer the polyol component providing both carboxylate groups and sulfonate groups; dispersing the isocyanate terminated prepolymer in aqueous media; reacting said dispersed isocyanate terminated polyurethane prepolymer with at least one amine functional chain extender or chain terminator compound to thereby form said poly(urethane/urea) polymer; neutralizing the carboxylate and sulfonate groups of said isocyanate terminated prepolymer with an alkali hydroxide or a tertiary amine prior to, or simultaneous with, said reaction of said prepolymer and said amine functional chain extender or terminator; wherein the method is performed without a solvent distillation step.