摘要:
The present invention relates to a multi-stage process for the continuous preparation of thermoplastically processable polyurethanes with improved processing properties based on various polyols.
摘要:
A process for the continuous production of a thermoplastic molding composition containing a mixture of a TPU and a thermoplastic (co)polymer is disclosed. The process comprises (i) introducing into an extruder via a first feed point component I) with at least 3% by weight, with respect to component I), of at least one member selected from the group consisting of components A), B) and C), and(ii) metering in the balance of said A), B) and C) into said extruder via one or more subsequent feed points, (iii) extruding components I) and II) under conditions sufficient to cause A), B) and C) reaction to form TPU, and (iv) upon the completion of said reaction, removing the resulting mixture of TPU and (co)polymer from the extruder, wherein component I) comprises 1 to 60% by weight, with respect to the total mixture, of a thermoplastic (co)polymer, and wherein component II) comprises 99 to 40% by weight, with respect to the total mixture, of the polyurethane-forming components including A) an organic diisocyanate, B) a linear polyol having terminal hydroxyl groups and a number average molecular weight of 500 to 5000, and C) a chain extender having a molecular weight of 60 to 500, and wherein the molar ratio of NCO groups in A) to the groups which react with NCO in B) and C) is in the range of 0.9 to 1.2.
摘要:
Thermoplastically processable polyurethane elastomers are prepared by A) mixing one or more substantially linear polyols with a diisocyanate, B) reacting the resultant mixture substantially completely in a reactor at temperatures of >100.degree. C. to form a prepolymer, C) mixing the prepolymer with low molecular weight chain extenders, D) applying the reaction mixture prepared in stage C) to a support and allowing the mixture to react thereon to solidification.
摘要:
Process for the continuous preparation of thermoplastically processable polyurethane elastomers with improved softening properties is disclosed. The process is carried out in a tubular reactor at a ratio of the circumferential speed of the stirrer (in m/sec) in the tubular reactor and the throughput (in g/sec) of >0.03 m/g.
摘要:
The present invention relates to a multi-stage process for the continuous preparation of thermoplastically processable polyurethanes with improved processing properties based on various polyols
摘要:
A process for the preparation of a polyurethane-urea elastomer having a mole ratio of NCO groups to all active hydrogen atoms in the range of 0.9 to 1.2 is disclosed. The process comprise reacting (A), (B) and (C.2) for form an NCO-containing prepolymer and then reacting said prepolymer with (C.1) and (D). Accordingly (A) is 5-isocyanato-1-(isocyanatomethyl)-1,1,3-trimethylcyclohexane or bis-(4-isocyanatocyclohexyl)-methane,(B) is polytetrahydrofuran or hexanediol polycarbonate and (C.2) is a chain extender. (C.1) is 5-amino-3-amino-methyl-1,3,3-trimethylcyclohexane or bis-(4-aminocyclohexyl)-methane and (D) is a molecular weight regulator. The elastomer thus produced is particularly suitable for the preparation of moldings, films, flexible tubing (for medical purposes) and catheters.
摘要:
A thermoplastic molding composition comprising a thermoplastic polyurethane and a wax mixture is disclosed. The polyurethane is a product of an organic diisocyanate, a linear, hydroxyl-terminated polyol and a diol or diamine chain extender. The wax mixture contains a first mixture of an ester of a C.sub.10-45 aliphatic carboxylic acid and a diol, and an alkali metal or alkaline earth metal salt of a C.sub.10-45 aliphatic carboxylic acids, and at least one member selected from the group consisting of fatty acid ester, fatty acid amide, fatty acid ester amide and polyethylene wax.
摘要:
The present invention relates to a process for the continuous production of thermoplastically processable polyurethanes having improved processing behaviour, wherein in a multistep reactionA) one or more linear hydroxyl-terminated polyols a) having a molecular weight of from 500 to 5000 are mixed continuously with a proportion of an organic diisocyanate b) in an NCO:OH ratio of from 2.0:1 to 5.0:1, in a mixing unit at high shear energy,B) the mixture prepared in step A) is reacted continuously to form an isocyanate-terminated prepolymer in a reactor at temperatures of >120.degree. C., until a conversion of >90%, referred to component a), is achieved,C) the prepolymer prepared in step B) is mixed with the remainder of component b), an NCO:OH ratio of from 2.05:1 to 6:1 being established overall in steps A) to C) and an NCO:OH ratio of 0.9 to 1.1 being established when all the components of steps A) to F) are included,D) the mixture prepared in step C) is cooled to a temperature of
摘要:
Thermoplastically processable polyurethane elastomers are produced by a process of A) mixing one or more substantially linear macrodiols with a diisocyanate, B) reacting the resultant mixture in a reactor at temperatures of >100.degree. C. to form a prepolymer, C) mixing the prepolymer with one or more low molecular weight chain extenders, and D) reacting the mixture prepared in stage C) to complete conversion in a high-shear, high-viscosity reactor.
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.