Polyisocyanates containing allophanate and isocyanurate groups, a process for their production and their use in two-component coating compositions

• US 5,124,427 A
• Filed: 01/22/1991
• Issued: 06/23/1992
• Est. Priority Date: 01/22/1991
• Status: Expired due to Term

• Current Assignee: Miles, Inc. (Bayer AG)
• Original Assignee: Miles, Inc. (Bayer AG)
• Inventors: Slack, William E., Potter, Terry A.
• Primary Examiner(s): WELSH JR, MAURICE
• Application Number:
  US07/644,174
• Time in Patent Office: 518 Days
• Field of Search: 528/67, 528/69, 528/73, 544/193, 252/182.21
• US Class Current: 528/67
• CPC Class Codes: C07D 251/34 Cyanuric or isocyanuric esters
• CPC Class Codes: C08G 18/022 the polymeric products containing isocyanurate groups
• CPC Class Codes: C08G 18/7837 containing allophanate groups
• CPC Class Codes: C08G 18/792 formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
• CPC Class Codes: C09D 175/04 Polyurethanes

Abstract

The present invention is directed to a polyisocyanate mixture having an NCO content of 10 to 47% by weight and a viscosity of less than 10,000 mPa.s and containing isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:1 to 1:5, wherein the allophanate groups are formed from urethane groups which are based on the reaction product of an organic diisocyanate having (cyclo)aliphatic bound isocyanate groups and a monoalcohol containing 1 to 5 carbon atoms.

The present invention is also directed to a process for the production of a polyisocyanate mixture having an NCO content of 10 to 47% by weight, having a viscosity of less than 10,000 mPa.s and containing isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:1 to 1:5 by

a) catalytically trimerizing a portion of the isocyanate groups of an organic diisocyanate having (cyclo)aliphatically bound isocyanate groups

b) adding 0.01 to 0.5 moles, per mole of organic diisocyanate, of a monoalcohol containing 1 to 5 carbon atoms to the organic diisocyanate prior to or during the trimerization reaction of step a) and

c) terminating the trimerization reaction at the desired degree of trimerization by adding a catalyst poison and/or by thermally deactivating the catalyst.

Finally, the present invention is directed to the use of these polyisocyanate mixtures, optionally in blocked form, as an isocyanate component in the two-component coating compositions.

Claims

1. A process for the production of a polyisocyanate mixture having an NCO content of 10 to 47% by weight and a viscosity of less than 10,000 mPa.s and containing isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:

1 to 1;

5 which comprises

a) catalytically trimerizing a portion of the isocyanate groups of an organic diisocyanate having (cyclo)aliphatically bound isocyanate groups in the presence of a trimerization catalyst with the exception of phosphines and Mannich bases,

b) adding 0.01 to 0.5 moles, per mole of said organic diisocyanate, of a monoalcohol containing 1 to 5 carbon atoms to said organic diisocyanate prior to or during the trimerization reaction of step a) and

c) terminating the trimerization reaction at the desired degree of trimerization by adding a catalyst poison and/or by thermally deactivating the catalyst.

2. The process of claim 1 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

3. The process of claim 1 wherein said monoalcohol contains 2 to 5 carbon atoms.

4. The process of claim 2 wherein said monoalcohol contains 2 to 5 carbon atoms.

5. The process of claim 1 wherein said monoalcohol contains 3 or 4 carbon atoms.

6. The process of claim 2 wherein said monoalcohol contains 3 or 4 carbon atoms.

14. The process of claim 1 wherein said trimerization catalyst contains quaternary ammonium groups or aminosilyl groups.

15. The process of claim 1 wherein said polyisocyanate mixture has a molar ratio of monoisocyanurates and monoallophanates of 5:

1 to 1;

2.

16. The process of claim 1 which comprises adding 0.04 to 0.2 moles of said monoalcohol per mole of said organic diisocyanate.

17. The process of claim 16 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

18. The process of claim 16 wherein said monoalcohol contains 3 or 4 carbon atoms.

19. The process of claim 17 wherein said monoalcohol contains 3 or 4 carbon atoms.

20. The process of claim 1 wherein said polyisocyanate mixture has a viscosity of less than 1300 mPa.s.

21. The process of claim 20 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

22. The process of claim 20 wherein said monoalcohol contains 3 or 4 carbon atoms.

23. The process of claim 21 wherein said monoalchol contains 3 or 4 carbon atoms.

24. The process of claim 16 wherein said polyisocyanate mixture has a viscosity of less than 1300 mPa.s.

25. The process of claim 24 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

26. The process of claim 24 wherein said monoalcohol contains 3 or 4 carbon atoms.

27. The process of claim 25 wherein said monoalchol contains 3 or 4 carbon atoms.

7. A polyisocyanate mixture having an NCO content of 10 to 47% by weight and a viscosity of less than 10,000 mPa.s and containing isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:

1 to 1;

5, wherein said allophanate groups are formed from urethane groups which comprise the reaction product of an organic diisocyanate having (cyclo)aliphatic bound isocyanate groups and a monoalcohol containing 1 to 5 carbon atoms.

8. The polyisocyanate mixture of claim 7 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

9. The polyisocyanate mixture of claim 7 wherein said monoalcohol contains 2 to 5 carbon atoms.

10. The polyisocyanate mixture of claim 8 wherein said monoalcohol contains 2 to 5 carbon atoms.

11. The polyisocyanate mixture of claim 7 wherein said monoalcohol contains 3 or 4 carbon atoms.

12. The polyisocyanate mixture of claim 8 wherein said monoalcohol contains 3 or 4 carbon atoms.

13. A two-component coating composition comprising the polyisocyanate of claim 8 and a compound containing isocyanate-reactive groups.

28. The polyisocyanate mixture of claim 7 wherein the molar ratio of monoisocyanurates and monoallophanates is 5:

1 to 1;

2.

29. The polyisocyanate mixture of claim 7 wherein said polyisocyanate mixture has a viscosity of less than 1300 mPa.s.

30. The polyisocyanate mixture of claim 29 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

31. The polyisocyanate mixture of claim 29 wherein wherein said monoalcohol contains 3 or 4 carbon atoms.

32. The polyisocyanate mixture of claim 30 wherein said monoalcohol contains 3 or 4 carbon atoms.

33. A polyisocyanate mixture having an NCO content of 10 to 47% by weight and a viscosity of less than 10,000 mPa.s and containing isocyanurate and allophanate groups in a molar ratio of monoisocyanurates to monoallophanates of 10:

1 to 1;

5 which is prepared by a process comprising

a) catalytically trimerizing a portion of the isocyanate groups of an organic diisocyanate having (cyclo)aliphatically bound isocyanate groups in the presence of a trimerization catalyst with the exception of phosphines and Mannich bases,

b) adding 0.01 to 0.5 mmoles, per mole of said organic diisocyanate, of a monoalcohol containing 1 to 5 carbon atoms to said organic diisocyanate prior to or during the trimerization reaction of step a) and

c) terminating the trimerization reaction at the desired degree of trimerization by adding a catalyst point and/or by thermally deactivating the catalyst.

34. The polyisocyanate mixture of claim 33 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

35. The polyisocyanate mixture of claim 33 wherein said monoalcohol contains 2 to 5 carbon atoms.

36. The polyisocyanate mixture of claim 34 wherein said monoalcohol contains 2 to 5 carbon atoms.

37. The polyisocyanate mixture of claim 33 wherein said monoalcohol contains 3 to 4 carbon atoms.

38. The polyisocyanate mixture of claim 34 wherein said monoalcohol contains 3 or 4 carbon atoms.

39. The polyisocyanate mixture of claim 33 wherein said trimerization catalyst contains quaternary ammonium groups or aminosilyl groups.

40. The polyisocyanate mixture of claim 33 wherein said polyisocyanate mixture has a molar ratio of monoisocyanurates and monoallphanates of 5:

1 to 1;

2.

41. The polyisocyanate mixture of claim 33 which comprises adding 0.04 to 0.2 moles of said monoalcohol per mole of said organic diisocyanate.

42. The polyisocyanate mixture of claim 41 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

43. The polyisocyanate mixture of claim 41 wherein said monoalcohol contains 3 or 4 carbon atoms.

44. The polyisocyanate mixture of claim 42 wherein said monoalcohol contains 3 or 4 carbon atoms.

45. The polyisocyanate mixture of claim 33 wherein said polyisocyanate mixture has a viscosity of less than 1300 mPa.s.

46. The polyisocyanate mixture of claim 45 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

47. The polyisocyanate mixture of claim 45 wherein said monoalcohol contains 3 or 4 carbon atoms.

48. The polyisocyanate mixture of claim 46 wherein said monoalcohol contains 3 or 4 carbon atoms.

49. The polyisocyanate mixture of claim 41 wherein said polyisocyanate mixture has a viscosity of less than 1300 mPa.s.

50. The polyisocyanate mixture of claim 49 wherein said organic diisocyanate comprises 1,6-hexamethylene diisocyanate.

51. The polyisocyanate mixture of claim 49 wherein said monoalcohol contains 3 or 4 carbon atoms.

52. The polyisocyanate mixture of claim 50 wherein said monoalcohol contains 3 or 4 carbon atoms.