Silicon-terminated polyurethane polymer

• US 4,345,053 A
• Filed: 07/17/1981
• Issued: 08/17/1982
• Est. Priority Date: 07/17/1981
• Status: Expired due to Term

• Current Assignee: Essex Chemical Corp. (Dow, Inc.)
• Original Assignee: Essex Chemical Corp. (Dow, Inc.)
• Inventors: Rizk, Sidky D., Hsieh, Harry W. S., Prendergast, John J.
• Primary Examiner(s): Marquis, Melvyn I.
• Application Number:
  US06/284,195
• Time in Patent Office: 396 Days
• Field of Search: 525/440, 525/453, 528/17, 528/18, 528/28, 528/26, 260/37 N, 524/588
• US Class Current: 525/440.03
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/718 containing silicon
• CPC Class Codes: C09K 2003/1056 Moisture-curable materials
• CPC Class Codes: C09K 3/1021 Polyurethanes or derivatives thereof

Abstract

What are disclosed are the method of making a moisture-curable silicon terminated organic polymer which comprises reacting a polyurethane prepolymer having terminal active hydrogen atoms with an isocyanato organosilane having at least one hydrolyzable alkoxy group bonded to silicon, silicon terminated organic polymers so produced, and moisture-curable sealant compositions comprising such a silicon terminated polymer.

Claims

1. The method of making a moisture-curable silicon terminated polymer which comprises reacting a polyurethane prepolymer having terminal active hydrogen atoms with an isocyanato organosilane having a terminal isocyanate group and at least one hydrolyzable alkoxy group bonded to silicon.

2. A method as in claim 1 wherein said isocyanato organosilane has from one to three hydrolyzable alkoxy groups bonded to silicon.

3. A method as in claim 1 wherein said isocyanato organosilane is a compound of the formula

4. A method as in claim 1 wherein said isocyanato organosilane having at least one hydrolyzable alkoxy group bonded to silicon is gamma-isocyanatopropyl triethoxysilane.

5. A moisture-curable silicon terminated organic polymer made by the method of claim 4.

6. A method as in claim 1 wherein said polyurethane prepolymer has terminal --OH, --SH, or --NH₂ groups.

7. A method as in claim 1 wherein said polyurethane prepolymer has terminal --OH groups and is prepared by reacting an excess of a polyol with an organic polyisocyanate.

8. A method as in claim 7 wherein said polyol is a polyether polyol.

9. A method as in claim 8 wherein said polyether polyol is a polyether diol.

10. A method as in claim 9 wherein said polyether diol is a polyoxyalkylene diol.

11. A method as in claim 8 wherein said polyether polyol is a mixture of a polyether diol and a polyether triol.

12. A method as in claim 11 wherein said polyether diol is a polyoxyalkylene diol and said polyether triol is a polyoxyalkylene triol.

13. A method as in claim 1 wherein said polyurethane prepolymer has terminal --OH groups and also has urea groups within the polymer chain and is prepared by reacting an excess of a mixture of a polyol and water with an organic polyisocyanate.

14. A method as in claim 13 wherein up to 25 percent of the total hydroxyl equivalents in said mixture are present in said water.

15. A method as in claim 7 wherein said polyol is a polyester polyol.

16. A method as in claim 15 wherein said polyester polyol is a polyester diol.

17. A method as in claim 16 wherein said polyester diol is a polyalkanolactone diol.

18. A moisture curable silicon terminated organic polymer made by the method of claim 1.

19. A moisture-curable sealant composition comprising a moisture curable silicon terminated organic polymer as in claim 18 in combination with at least one filler.

20. A sealant composition as in claim 19 which additionally comprises a curing catalyst for said silicon terminated organic polymer.

21. A sealant composition as in claim 20 wherein said catalyst is a quaternary ammonium hydroxide.

22. A sealant composition as in claim 21 wherein said catalyst is benzyltrimethylammonium hydroxide.

23. A sealant composition as in claim 19 which additionally comprises an amino organosilane having at least one hydrolyzable alkoxy group bonded to silicon.

24. A sealant composition as in claim 23 wherein said amino organosilane is N-(beta-aminoethyl)-gamma-aminopropyltrimethoxy silane.

25. A sealant composition as in claim 23 wherein said amino organosilane is N-(beta-aminoethyl),N'"'"'-(gamma-trimethoxysilyl propyl)-ethylene diamine.