Abstract: The invention relates to stable silicon dioxide dispersions and also their use for producing polyurethanes. The silicon dioxide dispersions are largely or preferably completely free of water and comprise silicon dioxide particles having an average diameter of 1-150 nm and at least one chain extender. The silicon dioxide particles can be modified by means of a silane (S) which comprises groups which are reactive toward isocyanates. Furthermore, a polyol, in particular a polyesterol and/or an isocyanate-comprising compound can be comprised in the silicon dioxide dispersions.

Abstract: The invention relates to a process for preparing polyester alcohols by catalytic reaction of at least one at least polyfunctional carboxylic acid with at least one polyfunctional alcohol and/or by catalytic ring-opening polymerization of cyclic esters in the presence of catalysts, wherein a zeolite is used as catalyst.

Abstract: The invention relates to a process for preparing polyester alcohols by catalytic reaction of at least one at least polyfunctional carboxylic acid with at least one polyfunctional alcohol and/or by catalytic ring-opening polymerization of cyclic esters in the presence of catalysts, wherein a zeolite is used as catalyst.

Abstract: The invention relates to polyurethanes based on a thermoplastic polyurethane and an isocyanate concentrate having a functionality greater than 2 and less than 10 added to the thermoplastic polyurethane, wherein the hard phase content of the thermoplastic polyurethane is in the range from 0% to 5% and the isocyanate concentrate is added in an amount of at least 2% by weight based on the polyurethane PU-1.

Abstract: The invention relates to a process for preparing polyester alcohols by catalytic reaction of at least one at least polyfunctional carboxylic acid with at least one polyfunctional alcohol and/or by catalytic ring-opening polymerization of cyclic esters in the presence of catalysts, wherein a zeolite is used as catalyst.

Abstract: The invention relates to polyurethanes based on a thermoplastic polyurethane and an isocyanate concentrate having a functionality greater than 2 and less than 10 added to the thermoplastic polyurethane, wherein the hard phase content of the thermoplastic polyurethane is in the range from 0% to 5% and the isocyanate concentrate is added in an amount of at least 2% by weight based on the polyurethane PU-1.

Abstract: The invention relates to stable silicon dioxide dispersions and also their use for producing polyurethanes. The silicon dioxide dispersions are largely or preferably completely free of water and comprise silicon dioxide particles having an average diameter of 1-150 nm and at least one chain extender. The silicon dioxide particles can be modified by means of a silane (S) which comprises groups which are reactive toward isocyanates. Furthermore, a polyol, in particular a polyesterol and/or an isocyanate-comprising compound can be comprised in the silicon dioxide dispersions.

Abstract: The invention relates to an improved method of melt adhesive bonding on the basis of a thermoplastic polyurethane using a thermoplastic polyurethane (TPU) obtainable from essentially a symmetrical aliphatic diisocyanate A and at least one isocyanate-reactive compound B comprising hydroxyl and/or amino groups as an adhesive, wherein the number-average molecular weight (Mn) of compound B is at least 2200 g/mol, with the proviso that it is at least 950 g/mol if compound B is a sebacic ester, diisocyanate A and at least one isocyanate-reactive compound B are reacted in the presence of a catalyst for the polyaddition reaction, the TPU comprises no chain extender, the TPU has an index IN of less than 1000, preferably of less than 990, and more preferably of less than 980, and melt adhesive bonding by the TPU in melt state takes place at a temperature from 50° C. to 160° C. in the absence of solvents, and to substrates bonded therewith.