Abstract: Process for the preparation of polyether alcohols, wherein the alkoxylation is carried out in the presence of sheet silicates.

Abstract: The invention relates to swelling-resistant integral polyurethane foams obtainable by reacting polyisocyanate prepolymers (a) with a polyol mixture (b) comprising a polyether polyol (b1) based on a bifunctional starter molecule and a polyether polyol (b2) based on a trifunctional to pentafunctional starter molecule, with the polyols (b1) and (b2) being prepared by alkoxylation by means of ethylene oxide (hereinafter referred to as EO) and propylene oxide (hereinafter referred to as PO), having an ethylene oxide content of more than 50% by weight and at least 5% of the ethylene oxide being present as an EO end cap.

Abstract: Polyester-polyether block copolymers can be prepared by catalytic addition of alkylene oxides onto H-functional initiator substances, using polyester alcohols as H-functional initiator substances and multimetal cyanide compounds as catalysts.

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to prepolymers containing isocyanate groups which can be prepared by reactinga) organic isocyanates withb) polyetherols containing at least 2 hydroxyl groups per molecule and having molecular weights of greater than 400 and/or polyesterols containing at least 2 hydroxyl groups per molecule and having molecular weights of greater than 400,c) isocyanate-reactive compounds which are at least difunctional and have molecular weights of from 18 to 399, and, if desired,d) Lewis and/or Bronsted acidic compounds ande) conventional auxiliaries and additives, such as antioxidants, light stabilizers or fillers,wherein at least one aromatic aminopolyether alcohol of the formula ##STR1## where R is aryl, alkylaryl containing one or more C.sub.1 - to C.sub.4 -alkyl groups, haloaryl, nitroaryl or cyanoaryl,R' and R" are identical or different and are, independently of one another, hydrogen, alkyl, aryl, aralkyl, alkoxyalkyl, alkoxyaryl or aroxyaryl,x and y are independent of one another andx+y.gtoreq.

Abstract: The invention relates to prepolymers containing isocyanate groups which can be prepared by reactinga) organic isocyanates withb) polyetherols containing at least 2 hydroxyl groups per molecule and having molecular weights of greater than 400 and/or polyesterols containing at least 2 hydroxyl groups per molecule and having molecular weights of greater than 400,c) isocyanate-reactive compounds which are at least difunctional and have molecular weights of from 18 to 399, and, if desired,d) Lewis and/or Bronsted acidic compounds ande) conventional auxiliaries and additives, such as antioxidants, light stabilizers or fillers,wherein at least one aromatic aminopolyether alcohol of the formula ##STR1## where R is aryl, alkylaryl containing one or more C.sub.1 - to C.sub.4 -alkyl groups, haloaryl, nitroaryl or cyanoaryl,R' and R" are identical or different and are, independently of one another, hydrogen, alkyl, aryl, aralkyl, alkoxyalkyl, alkoxyaryl or aroxyaryl,x and y are independent of one another andx+y.ltoreq.