Curable organopolysiloxane composition
Crosslinkable compositions containing an alkoxy-functional polyorganosiloxane and a titanium chelate complex exhibit good moisture-curing properties and produce coatings resistant to temperature ramp extremes.
1. A crosslinkable organopolysiloxane composition, prepared by admixing:
(A) an organopolysiloxane component, the organopolysiloxane consisting of units of the formula
R a Si(OR 1 ) b O (4-a-b)/2 (1),
where
R are identical or different monovalent, optionally substituted hydrocarbon radicals optionally interrupted by heteroatoms,
R 1 are identical or different monovalent, optionally substituted hydrocarbon radicals optionally interrupted by heteroatoms,
a is 0, 1, 2, or 3, and
b is 0, 1, 2, or 3,
with the proviso that the sum a+b is ≦3 in at least one unit b is other than 0, and in more than 50% of all units of the formula (1) in the organopolysiloxane a is 1, and
(B) at least one titanium chelate complex, wherein units of the formula (I) include D units where the sum of a+b is 2.
2. The crosslinkable organopolysiloxane composition of claim 1 , wherein component (B) comprises at least one titanium chelate complex selected from the group consisting of bis(ethylacetoacetato-O1′,O3)bis(propan-2-olato)titanium, bis(ethylacetoacetato-O1′,O3)bis(isobutan-1-olato)titanium, and bis(ethylacetoacetato-O1′,O3)bis(n-butan-1-olato)titanium.
3. The crosslinkable organopolysiloxane composition of claim 2 , comprising component (B) in an amount of from 0.001 to 50 parts by weight, based on 100 parts by weight of organopolysiloxane (A).
4. The crosslinkable organopolysiloxane composition of claim 1 , comprising component (B) in an amount of from 0.001 to 50 parts by weight, based on 100 parts by weight of organopolysiloxane (A).
5. The crosslinkable organopolysiloxane composition of claim 1 , further comprising one or more of
(C) fillers,
(D) pigments,
(E) binders, and
(F) additives selected from the group consisting of defoamers, deaerating agents, lubricants, flow control agents, organic solvents, dispersing agents, wetting agents, substrate wetting agents, thixotropic agents, water scavengers, and adhesion promoters.
6. The crosslinkable organopolysiloxane composition of claim 5 , wherein apart from components (A) to (F), the crosslinkable organopolysiloxane compositions contain no other components.
7. A process for preparing a crosslinkable organopolysiloxane composition of claim 1 , comprising mixing the individual constituents together.
8. A shaped body, prepared by crosslinking a composition prepared by the process of claim 7 .
9. The shaped body of claim 8 , which is a coating.
10. A shaped body prepared by crosslinking the crosslinkable organopolysiloxane composition of claim 1 .
11. The shaped body of claim 10 , which is a coating.
12. The composition of claim 1 , wherein in more than 80% of units of the formula (I), a is 1.
13. The crosslinkable organopolysiloxane composition of claim 1 , wherein the organopolysiloxane (A) has a viscosity of 5 to 5000 mm 2 /s at 25° C.
14. The crosslinkable organopolysiloxane composition of claim 13 , wherein component (B) comprises at least one titanium chelate complex selected from the group consisting of bis(ethylacetoacetato-O1′,O3)bis(propan-2-olato)titanium, bis(ethylacetoacetato-O1′,O3)bis(isobutan-1-olato)titanium, and bis(ethylacetoacetato-O1′,O3)bis(n-butan-1-olato)titanium.
15. The crosslinkable organopolysiloxane composition of claim 13 , comprising component (B) in an amount of from 0.001 to 50 parts by weight, based on 100 parts by weight of organopolysiloxane (A).
16. A crosslinkable organopolysiloxane composition, prepared by admixing:
(A) an organopolysiloxane component, the organopolysiloxane consisting of units of the formula
R a Si(OR 1 ) b O (4-a-b)/2 (1),
where
R are identical or different monovalent, optionally substituted hydrocarbon radicals optionally interrupted by heteroatoms,
R 1 are identical or different monovalent, optionally substituted hydrocarbon radicals optionally interrupted by heteroatoms,
a is 0, 1, 2, or 3, and
b is 0, 1, 2, or 3,
with the proviso that the sum a+b is ≦3, in at least one unit b is other than 0, and in more than 50% of all units of the formula (1) in the organopolysiloxane a is 1, and
(B) at least one titanium chelate complex, and
E) a binder selected,
wherein at least one binder is present and is selected from the group consisting of acrylic resins, polyester resins, alkyd resins, polyols, and hydrocarbon resins.
17. The composition of claim 16 , wherein the binder is present and comprises an alkyl orthosilicate or hydrolysate thereof.