摘要:
A process for the continuous production of a thermoplastic molding composition containing a mixture of TPU and a (co)polymer is disclosed. The process comprises (a) introducing into an extruder under time and temperature conditions sufficient to bring about the formation of thermoplastic polyurethane a (co)polymer, and polyurethane-forming components comprising A) an organic diisocyanate, B) a linear polyol having terminal hydroxyl groups and a molecular weight of 500 to 5000, and C) a chain extender having a molecular weight of 60 to 500, and upon completing the formation of said polyurethane (b) discharging the resulting TPU/(co)polymer mixture from the extruder. Importantly, the (co)polymer contains a flow enhancer and the molar ratio of the NCO groups in A) to the groups which react with NCO in B) and C) is 0.9 to 1.2.
摘要:
This invention relates to a process for standardized preparation of thermoplastic polyurethane elastomers by deactivating metal traces during the reaction, at an NCO:OH ratio of between about 0.85 and about 1.2:1, of(a) substantially linear hydroxyl-terminated polyols;(b) organic diisocyanates;(c) optional diol chain extenders; and(d) optional catalysts or other auxiliaries and/or additives, in the presence of(e) 0.000001 to 0.3% by weight, based on the total weight of the other components, of certain phosphorus compounds, wherein the phosphorus compounds are added to one or more of the other components before or during preparation of the thermoplastic polyurethane elastomers.
摘要:
Silica-containing acrylic and modacrylic fibres are obtained without spinning defects in that an aqueous silica sol is reacted with a silane and with a polar organic solvent, the sequence in which the two agents are added being optional, the water is distilled off in a vacuum at a temperature of at most 60.degree. C., the thread-forming polymer is then added in a quantity which is sufficient to form a spinnable solution and the solution is spun.