摘要:
In a process for producing sound-absorbing PUR foams having an adhesive surface by reacting organic and/or modified organic polyisocyanates (a) with a polyetherol mixture (b) and, if desired, further compounds (c) bearing hydrogen atoms which are reactive toward isocyanates, in the presence of water and/or other blowing agents (d), catalysts (e) and, if desired, further auxiliaries and additives (f), the polyetherol mixture (b) comprises b1) at least one bifunctional to eight-functional polyetherol based on ethylene oxide and propylene oxide and having an OH number of from 20 to 80 mg KOH/g and a proportion of primary OH groups of >50%, b2) at least one polyetherol based on ethylene oxide and propylene oxide and/or butylene oxide and a bifunctional to eight-functional initiator and having an OH number of from 20 to 80 mg KOH/g, where the proportion of ethylene oxide in the polyetherol is >30% by weight, in amounts of from 10 to 50 parts by weight, and b3) at least one polyetherol based on propylene oxide and/or butylene oxide and, if desired, ethylene oxide and a bifunctional to eight-functional initiator and having an OH number of from 30 to 400 mg KOH/g, where the proportion of ethylene oxide in the polyetherol is
摘要:
A homogeneous, demixing-stable polyol component comprising at least two relatively high molecular weight compounds containing at least two reactive hydrogen atoms and, if desired, low molecular weight chain extenders and/or crosslinkers and also, if desired, blowing agents, catalysts and further auxiliaries and/or additives is prepared by adding at least one amine and at least one organic and/or modified organic isocyanate to this component.This polyol component is useful for producing polyurethanes, in particular compact and foamed polyurethanes.
摘要:
The invention relates to a process for producing rigid polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms reactive toward isocyanate groups, in the presence of c) catalysts, and d) blowing agents, where, among the compounds having at least two hydrogen atoms reactive toward isocyanate groups, there is at least one graft polyol present capable of preparation via in-situ polymerization of ethylenically unsaturated monomers in polyether alcohols.
摘要:
The invention relates to graft polyols with a bimodal particle size distribution and a total solid content of between 5 and 65 wt. %. Said polyols contain small particles with a particle diameter of between 0.05 and 0.7 μm and large particles with a particle diameter of between 0.4 and 5.0 μm, whereby the peaks of the large and small particles measured during a representation according to the light-scattering analysis method do not overlap. The total solid content with the defined particle sizes consists of a volumetric fraction of between 5 and 45% small particles and a volumetric fraction of between 95 and 55% large particles, said volumetric fractions totalling 100%. The invention also relates to a method for producing graft polyols of this type and to the use thereof for producing polyurethanes.
摘要:
The invention relates to graft polyols with a bimodal particle size distribution and a total solid content of between 5 and 65 wt. %. Said polyols contain small particles with a particle diameter of between 0.05 and 0.7 μm and large particles with a particle diameter of between 0.4 and 5.0 μm, whereby the peaks of the large and small particles measured during a representation according to the light-scattering analysis method do not overlap. The total solid content with the defined particle sizes consists of a volumetric fraction of between 5 and 45% small particles and a volumetric fraction of between 95 and 55% large particles, said volumetric fractions totalling 100%. The invention also relates to a method for producing graft polyols of this type and to the use thereof for producing polyurethanes.
摘要:
The invention relates to thermoplastic polyurethanes, obtainable by reacting polyisocyanates with chain extenders and polymer polyols, wherein the polymer polyol is prepared by using a difunctional polyether polyol having exclusively primary OH groups and a molecular weight of from 500 to 2000 as a carrier polyol.
摘要:
The invention relates to a process for producing polyurethane foams by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups in the presence of c) catalysts, d) blowing agents, e) if desired, auxiliaries and additives, wherein the compounds having at least two hydrogen atoms which are reactive toward isocyanate groups comprise at least one polar graft polyol.
摘要:
The invention relates to a process for preparing mixtures of polyols for further processing to give polyurethanes, comprising at least one graft polyol, which comprises carrying out the mixing of the polyols between the preparation of the polyols and the preparation of the polyurethanes, by means of a continuous mixing process.
摘要:
The synthesis and characterization of a series of novel (AB).sub.n multiblock copolymers, typically thermoplastic elastomers, containing polyisobutylene as the soft phase and polyamides as the hard phase are described. First, carboxyl ditelechelic polyisobutylene prepolymers and isocyanate ditelechelic polyisobutylene prepolymers were synthesized, both of which were subsequently reacted under solution polycondensation conditions with dicarboxylic acids and diisocyanates. The melting points of the polyamide hard phases were in the 223.degree.-284.degree. C. range. The decomposition temperatures (296.degree.-337.degree. C.) in air and nitrogen of these thermoplastic elastomers were quite similar; in contrast, these properties of polytetrahydrofuran-based thermoplastic elastomers are noticeably lower in air. Melt processing of these novel polyisobutylene-based thermoplastic elastomers is possible.