Two-component polyurethane compositions containing OH-functional polydimethylsiloxanes
View Patent ↗The present invention relates to two-component compositions containing A) hydroxyl-containing polydimethylsiloxanes having number average molecular weights of 400 to 3000 and an average OH functionality of ≧1.8, and containing at least one structural unit of formula I) wherein R is an aliphatic, linear or branched C 1 to C 20 radical, R 1 is a linear or branched hydroxyalkyl radical having 2 to 10 carbon atoms and R 2 is either hydrogen or a linear or branched hydroxyalkyl radical having 2 to 10 carbon atoms, B) polyhydroxyl compounds other than A) or polyamines, and C) polyisocyanates. The present invention also relates to coatings, adhesives or sealants obtained from these compositions.
1. A two-component composition consisting of
A) a hydroxyl-containing polydimethylsiloxane having a number average molecular weight of 400 to 3000 and an average OH functionality of ≧1.8, and containing at least one structural unit of formula (I)
wherein R is an aliphatic, linear or branched C 1 to C 20 radical, R 1 is a linear or branched hydroxyalkyl radical having 2 to 10 carbon atoms and R 2 is either hydrogen or a linear or branched hydroxyalkyl radical having 2 to 10 carbon atoms,
B) a polyhydroxyl compound other than A) or a polyamine, and
C) a polyisocyanate.
2. The composition of claim 1 wherein component A) is used in an amount of 0.01% to 20% by weight and component B) is used in an amount of 80% to 99.99% by weight, wherein these percentages are based on the total weight of components A) and B).
3. The composition of claim 2 wherein the equivalent ratio of NCO groups to OH and/or NH-functional groups is 0.5:1 to 2.0:1.
4. The composition of claim 3 wherein radical R 1 is independently selected from the group consisting of —CH 2 —CH 2 —OH and —CH 2 —CH 2 —CH 2 —OH and radical R 2 is independently selected from the group consisting of H, —CH 2 —CH 2 —OH, and —CH 2 —CH 2 —CH 2 —OH.
5. The composition of claim 2 wherein radical R 1 is independently selected from the group consisting of —CH 2 —CH 2 —OH and —CH 2 —CH 2 —CH 2 —OH and radical R 2 is independently selected from the group consisting of H, —CH 2 —CH 2 —OH, and —CH 2 —CH 2 —CH 2 —OH.
6. The composition of claim 1 wherein component A) is used in an amount of 0.1% to 10% by weight and component B) is used in an amount of 90% to 99.90% by weight, wherein these percentages are based on the total weight of components A) and B).
7. The composition of claim 6 wherein the equivalent ratio of NCO groups to OH and/or NH-functional groups is 0.5:1 to 2.0:1.
8. The composition of claim 7 wherein radical R 1 is independently selected from the group consisting of —CH 2 —CH 2 —OH and —CH 2 —CH 2 —CH 2 —OH and radical R 2 is independently selected from the group consisting of H, —CH 2 —CH 2 —OH, and —CH 2 —CH 2 —CH 2 —OH.
9. The composition of claim 6 wherein radical R 1 is independently selected from the group consisting of —CH 2 —CH 2 —OH and —CH 2 —CH 2 —CH 2 —OH and radical R 2 is independently selected from the group consisting of H, —CH 2 —CH 2 —OH, and —CH 2 —CH 2 —CH 2 —OH.
10. The composition of claim 1 wherein the equivalent ratio of NCO groups to OH and/or NH-functional groups is 0.5:1 to 2.0:1.
11. The composition of claim 10 wherein radical R 1 is independently selected from the group consisting of —CH 2 —CH 2 —OH and —CH 2 —CH 2 —CH 2 —OH and radical R 2 is independently selected from the group consisting of H, —CH 2 —CH 2 —OH, and —CH 2 —CH 2 —CH 2 —OH.
12. The composition of claim 1 wherein radical R 1 is independently selected from the group consisting of —CH 2 —CH 2 —OH and —CH 2 —CH 2 —CH 2 —OH and radical R 2 is independently selected from the group consisting of H, —CH 2 —CH 2 —OH, and —CH 2 —CH 2 —CH 2 —OH.
13. A coating, adhesive or sealant obtained from the composition of claim 1 .
14. A substrate that has been coated, bonded or sealed with the composition of claim 1 .
15. A two-component composition consisting of
A) a hydroxyl-containing polydimethylsiloxane having a number average molecular weight of 400 to 3000 and an average OH functionality of ≧1.8, and containing at least one structural unit of formula (I)
wherein R is an aliphatic, linear or branched C 1 to C 20 radical, R 1 is a linear or branched hydroxyalkyl radical having 2 to 10 carbon atoms and R 2 is either hydrogen or a linear or branched hydroxyalkyl radical having 2 to 10 carbon atoms,
B) a polyhydroxyl compound other than A) or a polyamine,
C) a polyisocyanate, and
D) one or more surface-active substances, internal release agents, fillers, dyes, pigments, flame retardants, hydrolysis inhibitors, microbiocides, flow control assistants, solvents and/or antioxidants.