Catalyst composition for water blown, low density, rigid polyurethane foam

1. A method for preparing a water blown, low density, rigid polyurethane foam which comprises contacting at least one polyisocyanate with at least one polyol, at an Isocyanate Index of 70 to 200, in the presence of a blowing agent composition comprising at least 75 wt % water and an effective amount of a catalyst composition comprising a gelling catalyst which is bis-(N,N-dimethylaminopropyl)amine and a blowing catalyst which is N,N-dimethylaminoethyl-N′-methyl-ethanolamine, the foam having a density of 6 to 16 Kg/m 3 .

2. The method of claim 1 , wherein the catalyst composition is present in an amount from 5 to 60 parts by weight per hundred weight parts polyol.

3. The method of claim 1 , wherein the catalyst composition is present in an amount from 10 to 55 parts by weight per hundred weight parts of polyol.

4. The method of claim 1 , wherein:

(a) the at least one polyol, the blowing agent composition, and the catalyst composition are contacted to form a premix; and

(b) the premix is contacted with the at least one polyisocyanate.

5. The method of claim 4 , wherein step (a) further comprises at least one urethane catalyst.

6. The method of claim 1 , wherein the catalyst composition comprises 50 to 95 wt % bis-(N,N-dimethylaminopropyl)amine and 5 to 50 wt % N,N-dimethylaminoethyl-N′-methyl-ethanolamine.

7. The method of claim 1 , wherein the catalyst composition comprises 60 to 90 wt % bis-(N,N-dimethylaminopropyl)amine and 10 to 40 wt % N,N-dimethylaminoethyl-N′-methyl-ethanolamine.

8. The method of claim 1 wherein the foam density is 8 to 14 Kg/m 3 .

9. The method of claim 1 wherein the foam density is about 8 Kg/m 3 .

10. The method of claim 1 wherein the Isocyanate Index is 80 to 180.

11. The method of claim 1 wherein the blowing agent composition is present at 10 to 80 pphp.

12. The method of claim 1 wherein the blowing agent composition is present at 12 to 60 pphp.

13. The method of claim 1 wherein the blowing agent comprises at least 80 wt % water.

14. The method of claim 1 which comprises

(a) forming a premix comprising:

i) the at least one polyol;

ii) 10 to 80 pphp water;

iii) 0.5 to 10 pphp silicon surfactant;

iv) 0 to 50 pphp flame retardant;

v) 0 to 60 pphp urethane catalyst; and

vi) 5 to 60 pphp of the catalyst composition; and

(b) contacting the premix with the at least one polyisocyanate at an Isocyanate Index from about 70 to about 200.

15. A composition comprising the contact product of:

(a) at least one polyol, and

(b) a catalyst composition comprising 50 to 95 wt % bis-(N,N-dimethylaminopropyl)amine and 5 to 50 wt % N,N-dimethylaminoethyl-N′-methyl-ethanolamine.

16. The composition of claim 15 , further comprising at least one urethane catalyst.

17. The composition of claim 15 , further comprising at least one additive selected from at least one cell stabilizer, at least one flame retardant, at least one chain extender, at least one epoxy resin, at least one acrylic resin, at least one filler, at least one pigment, or any combination thereof.

18. The composition of claim 17 , wherein the at least one polyol is at least one polyether polyol, at least one polyester polyol, or any combination thereof.

19. The composition of claim 18 , wherein the catalyst composition comprises 60 to 90 wt % bis-(N,N-dimethylaminopropyl)amine and 10 to 40 wt % N,N-dimethylaminoethyl-N′-methyl-ethanolamine.

20. The method of claim 1 , wherein the catalyst composition comprises 85 wt % bis-(N,N-dimethylaminopropyl)amine and 15 wt % N,N-dimethylaminoethyl-N′-methyl-ethanolamine.