Composition comprising cyclic secondary amine and methods of coating drinking water pipelines

Patent metadata

Field	Value
Publication number	US-9908146-B2
Application number	US-201715484260-A
Country	US
Kind code	B2
Filing date	Apr 11, 2017
Priority date	Mar 30, 2011
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

Two-part coating compositions are described comprising an aliphatic cyclic secondary amine and methods of coating surfaces of a (e.g. drinking water) pipeline.

First claim

What is claimed is:

1. A method of forming a coating on a surface of a pipeline the method comprising the steps of:
a) providing a coating composition comprising
a first part comprising at least one aliphatic polyisocyanate that is a derivative of hexamethylene diisocyanate, and
a second part comprising at least 20 wt-% of aliphatic cyclic secondary diamine comprising secondary amine substituents that lack ester groups;

b) combining the first part and the second part to form a liquid mixture wherein the liquid mixture comprises about 15% to about 30% by volume inorganic particulate filler such that the liquid mixture can be applied at a caliper of at least 5 mm in a single pass;
c) applying the liquid mixture to internal surfaces of the pipeline; and
d) allowing the mixture to set forming a cured coating.

2. The method of claim 1 wherein the second part comprises an aliphatic cyclic secondary diamine comprising two hexyl rings bonded by a bridging group.

3. The method of claim 2 wherein the aliphatic cyclic secondary diamine has the general formula:

wherein R 1 and R 2 are independently alkyl groups, having 1 to 10 carbon atoms and R 3, R 4, R 5 and R 6 are independently hydrogen or alkyl groups having 1 to 5 carbon atoms.

4. The method of claim 3 wherein R 1 and R 2 are independently alkyl groups comprising at least 2 carbon atoms and R 3 and R 4 are methyl or hydrogen.

5. The method of claim 1 wherein the second part comprises an aliphatic cyclic secondary diamine comprising a single hexyl ring.

6. The method of claim 5 wherein the aliphatic cyclic secondary diamine has the general formula:

wherein R 7 and R 8 are independently linear or branched alkyl groups having 1 to 10 carbon atoms, or an alkylene group terminating with a —CN group, and R 9, R 10 and R 11 are independently hydrogen or an alkyl groups containing 1 to 5 carbon atoms.

7. The method of claim 6 wherein R 7 and R 8 are independently alkyl groups comprising at least 3 carbon atoms and wherein R 9, R 10 and R 11 are independently hydrogen or an alkyl groups containing 1 to 5 carbon atoms.

8. The method of claim 1 wherein the pipeline is a drinking water pipeline and the cured coating comes in contact with the drinking water.

9. The method of claim 1 wherein the second part comprises one or more of the aliphatic cyclic secondary diamine(s) in an amount ranging from 25 wt-% to 45 wt-% of the second part.

10. The method of claim 1 wherein the second part further comprises aliphatic acyclic secondary diamines.

11. The method of claim 1 wherein the first and second parts are free of aromatic compounds.

12. The method of claim 1 wherein the second part is free of hydroxy-functional components.

13. The method of claim 1 wherein the first part comprises a mixture of aliphatic polyisocyanates comprising diisocyanates, triisocyanates, and tetraisocyantes wherein the first part is substantially free of isocyanate monomer.

14. The method of claim 1 wherein the first part further comprises a derivative of isophorone diisocyanate.

15. The method of claim 1 wherein the first and/or second part comprises various additives selected from fumed silica, pigments, dispersing agents, and water scavengers.

16. The method of claim 1 wherein the first part is combined with the second part at a ratio of 1.25 to 1.35 equivalents isocyanate to amine.

17. The method of claim 1 wherein the first and second part each have a viscosity ranging from 5,000 centipoise to 60,000 centipoise with a spindle speed of 20 rpm at a temperature at which the liquid mixture is applied.

18. The method of claim 1 wherein the coating composition has a film set time of 30 to 180 seconds.

19. The method of claim 1 wherein the cured coating composition has a tensile strength ranging from 25 to 45 Mpa and a tensile elongation ranging from 2 to 10%.

20. The method of claim 1 wherein the cured coating composition has a flexural modulus ranging from 2000-4500 MPa.

Assignees

• 3M Innovative Properties Co

Inventors

• Prince Ryan B
• Jones Clinton L
• Fores Stuart E
• Kugel Alexander J
• Griesgraber Cori S
• Perez Mario A
• Reed Dana R

Classifications

• C08G18/73

  acyclic · CPC title

• B05D2254/04

  Applying the material on the interior of the tube · CPC title

• B05D7/222 Primary

  of pipes · CPC title

• C08G18/755

  and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate · CPC title

• C08G18/3234

  cycloaliphatic · CPC title