Two-component polyurethane casting compound with adjustable pot life

A polyurethane composition consisting of a first component A and a second component B;

• wherein
• the first component A comprises
• at least one polyol A1 having an OH functionality in the range from 1.5 to 4 and a mean molecular weight (number average) Mn, measured by means of GPC against polystyrene, in the range from 250 to 15 000 g/mol, and
• at least one diol A2 having two hydroxyl groups joined via a C2 to C9 carbon chain, and
• at least one compound T having at least one thiol group;
• and
• the second component B comprises
• at least one polyisocyanate I;
• wherein one of the components additionally comprises at least one metal catalyst K for the reaction of hydroxyl groups and isocyanate groups that is able to form thio complexes;
• and wherein the molar ratio of all the thiol groups in the at least one compound T to all metal atoms in the at least one metal catalyst K is between 1:1 and 250:1;
• and wherein the molar ratio of all NCO groups in the polyisocyanates I to all OH groups in the polyols A1 and A2=0.9:1-1.2:1;
• and wherein the polyurethane composition, directly after mixing of components A and B at 23° C., is free-flowing, preferably self leveling, and has a viscosity, measured at 20° C. on a plate-plate viscometer with plate separation 1 mm and plate diameter 25 mm, of <5000 Pa·s at a shear rate of 0.01 s−1.