Methods for controlling (extending) the pot life in chain-extended polyurethane (PU)-based systems
The invention relates to novel processes for controlling (extending) the pot life in polyurethane (PU) based systems that are chain-extended with diamines, preferably PU elastomers, PU adhesives, PU casting resins.
1. A process for extending the pot life of curable polyurethane (PU) based mixtures, the process comprising:
combining at least one carbodiimide of formula (I)
wherein:
m is >0,
R 1 , R 3 and R 5 are each independently H or methyl,
R 2 and R 4 are each H, methyl or —NH—C(O)—OR 10 , where R 10 is C 1 -C 4 -alkyl or —(CH 2 ) h —O—[(CH 2 ) k —O] g —R 11 , where h is 1-3, k is 1-3, g is 0-12 and R 11 is H or C 1 -C 4 -alkyl, and
one or more of R 6 , R 7 , R 8 and R 9 are each independently H or methyl,
at least one polyisocyanate,
a polyamine, and
at least one polyol selected from the group of polyester polyols and polyetherester polyols.
2. A process for extending the pot life of curable polyurethane (PU) based mixtures, the process comprising:
combining at least one carbodiimide of formula (I)
where:
R 1 , R 3 , R 4 and R 5 are each H or methyl, and
R 2 is —NH—C(O)—OR 10 , where R 10 is —C 1 -C 4 -alkyl or —(CH 2 ) h —O—[(CH 2 ) k —O] g —R 11 , where h is 1-3, k is 1-3, g is 0-12 and R 11 is H or C 1 -C 4 -alkyl,
at least one polyisocyanate,
a polyamine, and
at least one polyol selected from the group of polyester polyols and polyetherester polyols.
3. The process according to claim 2 , wherein R 1 , R 3 , and R 5 are each methyl, and R 4 is H.
4. A process for extending the pot life of curable polyurethane (PU) based mixtures, the process comprising:
combining at least one carbodiimide of formula (I)
wherein:
m is >0,
R 1 , R 3 , R 4 and R 5 are each H or methyl,
R 2 is —NH—C(O)—OR 10 , where R 10 is —C 1 -C 4 -alkyl or —(CH 2 ) h —O—[(CH 2 ) k —O] g —R 11 , where h is 1-3, k is 1-3, g is 0-12 and R 11 is H or C 1 -C 4 alkyl, and
R 6 , R 7 , R 8 and R 9 are each independently H or methyl,
at least one polyisocyanate,
a polyamine, and
at least one polyol selected from the group of polyester polyols and polyetherester polyols.
5. The process according to claim 4 , wherein R 1 , R 3 and R 5 are each methyl, R4 is H, and at least one of R 5 , R 7 and R 9 is methyl.
6. The process according to claim 1 , wherein:
the polyisocyanate is a diisocyanate;
the polyamine is a diamine; and
the carbodiimide, the diisocyanate, the diamine, and the polyol are combined at a temperature of 40° C. to 130° C.
7. The process according to claim 2 , wherein:
the polyisocyanate is a diisocyanate;
the polyamine is a diamine; and
the carbodiimide, the diisocyanate, the diamine, and the polyol are combined at a temperature of 40° C. to 130° C.
8. The process according to claim 4 , wherein:
the polyisocyanate is a diisocyanate;
the polyamine is a diamine; and
the carbodiimide, the diisocyanate, the diamine, and the polyol are combined at a temperature of 40° C. to 130° C.