Production of low-emission polyurethanes
The use of a mixture (M) comprising nitrogen compound(s) in the preparation of polyurethanes, especially polyurethane foams, wherein said mixture (M) comprises the following constituents: (a) N,N-dimethylaminopropylamine, at least in an amount of ≥5% by weight, advantageously in an amount of ≥20% by weight, preferably 20%-95% by weight, further preferably 30%-70% by weight, especially 30%-60% by weight, and (b) at least one solvent, especially water, advantageously in a total amount of ≥5% by weight, preferably ≥10% by weight, more preferably 10%-60% by weight, especially 10%-40% by weight, % by weight based in each case on the overall mixture (M), is described.
1. A polyurethane prepared from an isocyanate component, a polyol component, and a mixture (M) comprising the following constituents:
(a) N,N-dimethylaminopropylamine, in an amount of from 40% to 95% by weight, and
(b) at least one solvent, in an amount of ≥5% by weight,
(c) from a tertiary amine in an amount of from 15% to 60% by weight, wherein the tertiary amine is selected from the group consisting of
2-(dimethylamino)ethanol, 1,1′-{[3-(dimethylamino)propyl]imino}bis-2-propanol, bis(3-dimethylaminopropyl)amine, 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol, 2-(diethylamino)ethanol, 1-(2-hydroxyethyl)pyrrolidine, 2-(2-(dimethylamino)ethoxy)ethanol, 2-(2-(diethylamino)ethoxy)ethanol, 2-(2-(pyrrolidin-1-yl)ethoxy)ethanol, bis(2-dimethylaminoethyl) ether, 1,1′-(oxybis(ethane-2,1-diyl))dipyrrolidine, N-(2-(dimethylamino)ethyl)-N,N′,N′-trimethylethylene-1,2-diamine, N,N,N′,N′-tetramethyl-1,6-hexanediamine, 2-((2-(dimethylamino)ethyl)(methyl)amino)ethanol, 2-((2-(2-(dimethylamino)ethoxy)ethyl)(methyl)amino)ethanol, or N-(2-(2-(dimethylamino)ethoxy)ethyl)-N-methylpropane-1,3-diamine.
2. The polyurethane according to claim 1 , wherein (c) comprises bis(3-dimethylaminopropyl)amine in a total amount of from 35% to 60% by weight, based on the total weight of the mixture (M).
3. The polyurethane according to claim 1 , wherein (c) comprises 1,1′-{[3-(dimethylamino)propyl]imino}bis-2-propanol in a total amount of from 35% to 60% by weight, based on the total weight of the mixture (M).
4. The polyurethane according to claim 2 , wherein (c) comprises 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol in a total amount of from 35% to 60% by weight, based on the total weight of the mixture (M).
5. The polyurethane according to claim 1 , wherein the mixture (M) has a flashpoint of >60° C., measured by the Pensky-Martens method with a closed crucible in accordance with DIN EN ISO 2719:2003-09.
6. The polyurethane according to claim 1 , wherein the mixture (M) comprises
(a) N,N-dimethylaminopropylamine, in an amount of from 50% to 70% by weight, and
(b) water as the at least one solvent, in an amount of ≥5% by weight.
7. The polyurethane according to claim 1 wherein the mixture (M) comprises
(a) N,N-dimethylaminopropylamine, in an amount of from 50% to 95% by weight, and
(b) at least one organic solvent, in a total amount of ≥10% by weight.
8. The polyurethane according to claim 1 wherein the mixture (M) comprises
(a) N,N-dimethylaminopropylamine, in an amount of from 60% to 95% by weight, and
(b) water and/or organic solvent as the at least one solvent in an amount of from 10% to 60% by weight.
9. The polyurethane according to claim 2 , wherein (b) said at least one solvent is an organic solvent, and (c) comprises at least one amine selected from the group consisting of 1,1′-{[3-(dimethylamino)propyl]imino}bis-2-propanol, bis(3-dimethylaminopropyl)amine, and 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol.
10. The polyurethane according to claim 9 , wherein the molar ratio of the total amount of (c) relative to the total amount of isocyanate-reactive groups of the polyol component is from 4×10 −4 :1 to 0.2:1.
11. The polyurethane according to claim 9 , wherein (c) is used in a proportion by mass of 0.01 to 20.0 parts by weight per 100 parts by weight of polyol component.
12. A polyurethane foam comprising the polyurethane of claim 1 .
13. The polyurethane foam according to claim 12 , wherein said polyurethane foam is a rigid polyurethane foam, a flexible polyurethane foam, a viscoelastic foam, a cold-cure foam, a semi-rigid polyurethane foam, a thermoformable polyurethane foam or an integral foam, obtained using the mixture (M) in an amount of 0.005% to 10% by weight, based on the weight of the polyurethane foam.
14. The polyurethane according to claim 1 , wherein the mixture (M) comprises
(a) N,N-dimethylaminopropylamine in an amount of from 70% to 95% by weight, and
(b) water as the at least one solvent in an amount of 10% to 40% by weight.