Method for producing polyrethane soft foam materials
Process for producing flexible polyurethane foams in particular molded flexible polyurethane foams, by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, wherein the component b) comprises b1a) at least one polyether alcohol having an end block of ethylene oxide units which has been added on by means of DMC catalysis and makes up not more than 10% by weight of the weight of the alkylene oxide added on by means of DMC catalysis, and/or b1b) at least one polyether alcohol comprising a terminal mixture of ethylene oxide and propylene oxide which has been added on by means of DMC catalysis and has an ethylene oxide content in the mixture of at least 25% by weight, and also b2a) at least one polyether alcohol or comprising exclusively propylene oxide units, and/or b2b) at least one graft polyether alcohol.
1. A process for producing flexible polyurethane foams, comprising:
providing b1a) at least one polyether alcohol having an end block of exclusively ethylene oxide units wherein said end block has been added on by means of DMC catalysis only and the end block makes up not more than 10% by weight of the weight of the alkylene oxide added on by means of DMC catalysis,
providing at least one component selected from the group consisting of b2a) at least one polyether alcohol comprising exclusively propylene oxide units, and b2b) at least one graft polyether alcohol, and
reacting b1a) and at least one of b2a) and b2b) with one or more polyisocyanates.
2. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have a functionality of from 2 to 4.
3. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have a functionality of from 2 to 3.
4. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have a hydroxyl number in the range from 20 to 70 mg KOH/g.
5. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have a hydroxyl number in the range from 20 to 60 mg KOH/g.
6. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have an ethylene oxide content in the range from 5 to 25% by weight, based on the alkylene oxide added on by means of DMC catalysis.
7. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have an ethylene oxide content in the range from 8 to 25% by weight, based on the alkylene oxide added on by means of DMC catalysis.
8. The process according to claim 1 , wherein the polyether alcohols b1a) and b1b) have an ethylene oxide content in the range from 10 to 20% by weight, based on the alkylene oxide added on by means of DMC catalysis.
9. The process according to claim 1 , wherein the polyether alcohols b1a) have an amount of ethylene oxide at the end of the chain of not more than 10% by weight, based on the total amount of alkylene oxide added on by means of DMC catalysis.
10. The process according to claim 1 , wherein the component b) comprises at least 5% by weight of at least one polyol b1a) and/or b1b).
11. The process according to claim 1 , wherein the component b) comprises at least 10% by weight of at least one polyol b1a) and/or b1b).
12. The process according to claim 1 , wherein the component b) comprises from 10 to 25% by weight, based on the component b), of the polyether alcohol b2a).
13. The process according to claim 1 , wherein the component b) comprises graft polyols b2b) in an amount of from 5 to 25% by weight, based on the component b).
14. The process according to claim 1 , wherein the component b) comprises graft polyols b2b) in an amount of from 8 to 15% by weight, based on the component b).
15. The process according to claim 1 , wherein the component b) further comprises
b1b) at least one polyether alcohol comprising a terminal mixture of ethylene oxide and propylene oxide which has been added on by means of DMC catalysis and has an ethylene oxide content in the mixture of at least 25% by weight.