摘要:
A process for treating polyether polyols prepared in a conventional manner by base-catalyzed reaction of H-functional initiator substances with alkylene oxides comprises a combination of a thermal-reactive step at a pH of less than 7 and a temperature above 60° C. and a thermal-distillative step in a countercurrent column using a purifying agent. The polyether polyols prepared according to the invention are used for producing low-fogging and low-odor PUR foams.
摘要:
In a process for producing flexible polyurethane foams by reactinga) organic and/or modified organic polyisocyanates withb) relatively high molecular weight compounds containing at least two reactive hydrogen atoms andc) if desired, low molecular weight chain extenders and/or cross linkersin the presence ofd) blowing agents,e) catalysts,f) flame retardants and, if desiredg) further auxiliaries and/or additives,the relatively high molecular weight compounds containing at least two reactive hydrogen atoms (b) comprise at least 10% by weight of polyether polyols which can be prepared by base-catalyzed reaction of lower alkylene oxides with OH-functional initiator substances and are subjected, during or after the molecular addition of alkylene oxide, to a combined thermal/distillative treatment at a water content of at most 0.1% by weight.The flexible PUR foam produced according to the present invention can be used in the automobile and furniture sectors and for producing flexible foam/textile composites.
摘要:
In a process for preparing polyether polyols containing aromatics by molecular addition of alkylene oxides to H-functional initiators at from 70.degree. C. to 135.degree. C. and pressures of from 0.1 MPa to 1.0 MPa, the alkoxylation is carried out using at least one initiator comprising at least 95% by weight of 2,3 and 3,4 isomers of tolylenediamine, from 0.5 to 4% by weight of 2,4 and 2,6 isomers of tolylenediamine and from 0.1 to 1.5% by weight of more volatile fractions from tolylenediamine production. The polyether polyols prepared by this process can be used as component of a polyol mixture for producing rigid polyurethane foams.
摘要:
Polyurethanes having improved curing are prepared by reactinga) organic and/or modified organic diisocyanates and/or polyisocyanates withb) polyether polyols based on aromatic amines, able to be prepared by reacting specific amine combinations and, if desired, further coinitiators in a stage wise molecular addition of alkylene oxide, and also, if desired, further relatively high molecular weight compounds containing at least two reactive hydrogen atoms and, if desired,c) low molecular weight chain extenders and/or crosslinkers in the presence ofd) blowing agents,e) catalysts and, if desired,f) further auxiliaries and/or additives,wherein the specific amine combination used is a mixture of amines of the diphenylmethane series consisting of from 5 to 20% by weight of 4-ring amine, from 15 to 30% by weight of 3-ring amine, from 20 to 35% by weight of amines having more than 4 rings and from 25 to 50% by weight of 2-ring amine, wherein the proportions add up to 100% by weight, in combination with further aromatic amines.
摘要:
Aqueous dispersions containing a polyurethane built up from a) diisocyanates having 4 to 30 carbon atoms, b) diols, of which b.1) from 10 to 100 mol %, based on the total amount of the diols (b), have a molecular weight of from 500 to 5000 and are built up from b1.1) (C.sub.4 - to C.sub.30 -alkyl)succinic acid and/or (C.sub.4 - to C.sub.30 -alkenyl)succinic acid, b1.2) from 0 to 60 mol %, based on component (b1.1), of a dicarboxylic acid which is different from component (b1.1), and b1.3) a diol having a molecular weight of from 60 to 500 g/mol, b.2) from 0 to 90 mol %, based on the total amount of the diols (b), have a molecular weight of from 60 to 500 g/mol, and b.3) from 0 to 90 mol %, based on the total amount of the diols (b), have a molecular weight of from 500 to 5000 g/mol and are different from (b1), c) monomers which are different from the monomers (a) and (b) and contain at least 2 isocyanate groups or at least 2 isocyanate-reactive groups and which in addition carry at least one hydrophilic group or a potentially hydrophilic group, thus achieving the water-dispersibility of polyurethanes, d) if desired, further polyfunctional compounds which are different from the monomers (a) to (c) and contain reactive groups which are alcoholic hydroxyl groups, primary or secondary amino groups or isocyanate groups, and e) if desired, monofunctional compounds which are different from the monomers (a) to (c) and contain one reactive group, which is an alcoholic hydroxyl group, a primary or secondary amino group or an isocyanate group.
摘要:
A process for the production of rigid polyurethane foams involves reactinga) organic and/or modified organic polyisocyanates withb) at least one relatively high-molecular-weight compound containing at least two reactive hydrogen atoms, and, if desired,c) low-molecular-weight chain extenders and/or cross-linking agents,in the presence ofd) blowing agents,e) catalysts and, if desired,f) assistants and/or additives,where the relatively high-molecular-weight compounds (b) containing at least two reactive hydrogen atoms are polyoxypropylene-polyols and/or polyoxyethylene-polyoxy-propylene-polyols containing up to 20% by weight, based on the weight of the alkylene oxide units, of pendant oxyethylene units containing secondary hydroxyl groups and having a functionality of from 3.8 to 4.1, a hydroxyl number of from 385 to 410 mg of KOH/g and a viscosity of from 1700 to 2400 mPa.multidot.s at 25.degree. C., and which can be prepared by anionic polymerization of 1,2-propylene oxide and, if desired, ethylene oxide on an initiator molecule mixture comprising sucrose, pentaerythritol and diethylene glycol.
摘要:
The invention relates to a process for the preparation of bromine-containing polyols in which a bromine-containing alcohol is caused to react with an alkylene oxide in admixture with other H-functional compounds and the catalyst used is a system comprising alkaline and Lewis-acid catalysts.
摘要:
Polymeric polyesterols are prepared by in-situ polymerization of ethylenically unsaturated monomers in polyesterols in the presence of prepolymers made from polyesterols and isocyanates.