Polyurethane and polyurethane urea elastomers based on polycarbonate polyols

A process for the preparation of polyurethane elastomers and/or polyurethane urea elastomers, comprising reacting:

• (I) NCO prepolymers having an NCO content of 3 to 15 wt. % and which comprise the reaction product of
• (A) polycarbonate polyols having an OH number of 50 to 80 mg KOH/g and an average functionality of 1.9 to 2.2 which are obtained by reacting
• (1) a mixture consisting essentially of
• a) 15 wt. % to 85 wt. %, based on the mixture of a) and b), of one or more α,ω-alkanediols which have from 4 to 8 carbon atoms,
• b) 15 wt. % to 85 wt. %, based on the mixture of a) and b), of a dodecanediol mixture which consists essentially of
• (i) 30 to 50 wt. % of 1,12-dodecanediol,
• (ii) 30 to 50 wt. % of undecandiol, and
• (iii) 5-20 wt. % of one or more diols having from 6 to 10 carbon atoms, and
• c) 0 to 10 wt. %, based on the total weight of the mixture of a), b) and c), of one or more alkanols having from 4 to 10 carbon atoms and hydroxyl functionalities of 1 or 3;
• with
• (2) a carbonyl component selected from the group consisting of diaryl carbonates, dialkyl carbonates and carbonyl chloride,
• and
• (B) a polyisocyanate which is selected from the group consisting of 1,5-naphthalene diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, mixtures of 2,4′-diphenylmethane diisocyanate and 4,4′-diphenylmethane diisocyanate, carbodiimide-/uretonimine-modified diphenylmethane diisocyanate derivatives, polynuclear homologues of the diphenylmethane diisocyanate series, diisocyanatotoluenes, hexamethylene diisocyanate, isophorone diisocyanate and mixtures thereof, wherein (B) said polyisocyanate is present in a molar excess;
• with
• (II) a composition comprising:
• (A′) one or more aliphatic diols having primary hydroxyl groups and number-average molecular weights of 62 to 202, and in amounts of from 0 to 10 wt. %, based on the total weight of aliphatic diols, of one or more compounds selected from the group consisting of short-chain polyols with functionalities >2 to 4, higher-molecular-weight polyols with a functionality of 2 and polycarbonate polyols of (A), optionally, in the presence of water and/or further auxiliary substances and additives;
• or
• (B′) one or more aromatic diamine-type chain extenders selected from the group consisting of 4,4′-methylene-bis-(2-chloroaniline) (MBOCA), 3,3′,5,5′-tetraisopropyl-4,4′-diaminodiphenylmethane, 3,5-dimethyl-3′,5′-diisopropyl-4,4′-diaminophenylmethane, 3,5-diethyl-2,4-toluene diamine, 3,5-diethyl-2,6-toluene diamine (DETDA), 4,4′-methylene-bis-(3-chloro-2,6-diethylaniline), 3,5-dimethylthio-2,4-toluene diamine, 3,5-dimethylthio-2,6-toluene diamine, 3,5-diamino-4-chlorobenzoic acid isobutyl ester and mixtures thereof, optionally, in the presence of water and/or further auxiliary substances and additives.