Amine-initiated polyether polyols and a process for their production
View Patent ↗Clear, amine-initiated polyether polyols are made by epoxidizing an amine in the presence of an alkali metal hydroxide catalyst. By reducing the amount of catalyst used during the polyol synthesis and by adding the catalyst after between 5 and 30% of the total amount of at least one alkylene oxide has been added, after lactic acid neutralization, gives a short chain polyol that has foam processing characteristics similar to the conventional sulfuric acid neutralized polyol. The polyols produced in this manner are particularly useful for the production of polyurethane and polyisocyanurate foams.
1. A process for the production of short chain polyols comprising
i) contacting an amine with a first alkylene oxide, wherein the amount of alkylene oxide contacted with the amine is between 5 and 30% of the total amount of alkylene oxide to be added to the amine,
ii) adding from about 0.001 to 0.1 wt. % based on the weight of the finished polyol of an alkali metal hydroxide catalyst,
iii) contacting the amine with the remaining amount of the first alkylene oxide and then a second alkylene oxide,
iv) upon completion of the epoxidation, adding a hydroxy carboxylic acid to the epoxidized mixture, wherein the first alkylene oxide is a block of ethylene oxide and the second alkylene oxide is block of propylene oxide, wherein the amount of ethylene oxide used is about 20-40%, based on the total amount of alkylene oxide to be added to the amine, and wherein the amount of propylene oxide used is about 60-80%, based on the total amount of alkylene oxide to be added to the amine.
2. The process according to claim 1 , wherein the amine is orthotoluenediamine.
3. The process according to claim 1 , wherein the polyol has an average hydroxyl value of at least 200.
4. The process according to claim 3 , wherein the polyol has an average hydroxyl value of from about 300 to about 500.
5. The process according to claim 1 , wherein the alkali metal hydroxide catalyst is potassium hydroxide or sodium hydroxide.
6. The process according to claim 1 , wherein the catalyst is added in an amount from about 0.05 to about 0.1 weight percent, based upon the weight of the polyol.
7. The process according to claim 6 , wherein the catalyst is added in an amount from about 0.03 to about 0.07 weight percent, based upon the weight of the polyol.
8. The process according to claim 1 , wherein the hydroxy carboxylic acid is lactic acid, salicylic acid, substituted salicylic acids such as 2-hydroxy 3-methyl benzoic acid, 2-hydroxy 4-methyl benzoic acid a mixture thereof.
9. The process according to claim 8 , wherein the hydroxy carboxylic acid is lactic acid.
10. The process according to claim 1 , wherein the hydroxy carboxylic acid is added at a level of 0.70 to 1.30 equivalents of carboxylic acid per equivalent of the alkali metal hydroxide used for the alkoxylation.
11. The process according to claim 10 , wherein the hydroxy carboxylic acid is added at a level of 1.05 to 1.15 equivalents of carboxylic acid per equivalent of the alkali metal hydroxide used for the alkoxylation.
12. The process according to claim 9 , wherein the lactic acid is added at a level of 0.70 to 1.30 equivalents of carboxylic acid per equivalent of the alkali metal hydroxide used for the alkoxylation.
13. A polyether polyol produced by the process according to claim 1 .
14. A process for the production of a rigid foam comprising reacting an organic polyisocyanate with the polyol produced by the process according to claim 1 .
15. The process according to claim 14 , wherein the alkylene oxide is a block of ethylene oxide followed by a block of propylene oxide, wherein the amount of ethylene oxide used is about 20-40%, based on the total amount of alkylene oxide to be added to the amine, and
wherein the amount of propylene oxide used is about 60-80%, based on the total amount of alkylene oxide to be added to the amine.
16. The process according to claim 14 , wherein the amine is orthotoluenediamine.
17. The process according to claim 14 , wherein the polyol has an average hydroxyl value of at least 200.
18. The process according to claim 17 , wherein the polyol has an average hydroxyl value of from about 300 to about 500.
19. The process according to claim 14 , wherein the alkali metal hydroxide catalyst is potassium hydroxide or sodium hydroxide.
20. The process according to claim 14 , wherein the catalyst is added in an amount from about 0.05 to about 0.1 weight percent, based upon the weight of the polyol.
21. The process according to claim 20 , wherein the catalyst is added in an amount from about 0.03 to about 0.07 weight percent, based upon the weight of the polyol.
22. The process according to claim 14 , wherein the hydroxy carboxylic acid is lactic acid, salicylic acid, substituted salicylic acids such as 2-hydroxy 3-methyl benzoic acid, 2-hydroxy 4-methyl benzoic acid a mixture thereof.
23. The process according to claim 22 , wherein the hydroxy carboxylic acid is lactic acid.
24. The process according to claim 14 , wherein the hydroxy carboxylic acid is added at a level of 0.70 to 1.30 equivalents of carboxylic acid per equivalent of the alkali metal hydroxide used for the alkoxylation.
25. The process according to claim 24 , wherein the hydroxy carboxylic acid is added at a level of 1.05 to 1.15 equivalents of carboxylic acid per equivalent of the alkali metal hydroxide used for the alkoxylation.
26. The process according to claim 23 , wherein the lactic acid is added at a level of 0.70 to 1.30 equivalents of carboxylic acid per equivalent of the alkali metal hydroxide used for the alkoxylation.