Curable composition based on polysiloxanes
A curable composition can have a surface with amphiphilic properties which is thus able to counteract biofouling. The curable composition includes: a component A: at least one polysiloxane, a component B: at least one polyether bearing silyl groups and/or a reaction product of a polyether bearing silyl groups with one or more isocyanate-containing compounds, and a component C: at least one catalyst.
1. A curable composition, comprising:
a component A: at least one polysiloxane,
a component B: at least one polyether bearing silyl groups comprising formula (I):
where
a=1 to 100,
b=1 to 500,
c=0 to 500,
f=0 to 2,
g=1 to 3,
with the proviso that g+f=3,
h=1 to 10,
n=1 to 10,
with the proviso that the fragments having the indices a, b and c are distributed over the molecule chain in a freely permutable manner and that the sum total of a, b and c is >3, and where
R 1 =a saturated or unsaturated, linear or branched organic hydrocarbyl radical which may contain O, S and/or N as heteroatoms,
R 1* =hydrogen, a saturated or unsaturated, linear or branched organic hydrocarbyl radical which may contain O, S and/or N as heteroatoms,
R 2 =independently at each instance an alkyl group having 1 to 8 carbon atoms,
R 3 =independently at each instance an alkyl group having 1 to 8 carbon atoms,
R 4 =independently at each instance a hydrogen radical, a linear, branched or cyclic alkyl or chloroalkyl group having 1 to 20 carbon atoms,
R 5 =independently at each instance a hydrogen radical or a linear, branched or cyclic alkyl or chloroalkyl group having 1 to 20 carbon atoms, an aryl or alkaryl group,
and/or reaction products of a polyether bearing silyl groups of the formula (I) with one or more isocyanate-containing compounds, and a component C: at least one catalyst.
2. The curable composition according to claim 1 , wherein the polyether bearing silyl groups has various repeat units that are prepared by reaction of at least one member selected from the group consisting of one or more alkylene oxides, one or more glycidyl ethers, carbon dioxide, one or more cyclic anhydrides, one or more isocyanates, one or more caprolactones, one or more cyclic carbonates, and mixtures thereof.
3. The curable composition according to claim 1 , wherein the polysiloxane is a linear or singly or multiply branched Si—OH— or SiOR 3 -functional polysiloxane.
4. The curable composition according to claim 1 , wherein the polysiloxane is an alkoxypolysiloxane.
5. The curable composition according to claim 1 , wherein the polysiloxane has at least one member selected from the group consisting of at least one epoxy functionality and at least one alkoxy functionality.
6. The curable composition according to claim 1 , further comprising: at least one epoxy-functional compound and at least one amino-functional compound.
7. The curable composition according to claim 6 , wherein a stoichiometric ratio of epoxy function to amino function is in the range from 5:0.1 to 0.1:5.
8. The curable composition according to claim 6 , wherein the epoxy-functional compound comprises at least one member selected from the group consisting of an epoxy-functional silane, an epoxy-functional siloxane, an aromatic glycidyl ether, an aliphatic glycidyl ether, condensates thereof, and mixtures thereof.
9. The curable composition according to claim 6 , wherein the amino-functional compound is an amino-functional alkoxysilane.
10. The curable composition according to claim 1 , further comprising:
at least one crosslinker of formula (II)
R 6 d Si(OR 7 )e Formula (II)
with the proviso that 0≤d≤2, 0≤e≤4 and d+e=4,
R 6 =independently at each instance an alkyl group or cycloalkyl group having 1 to 8 carbon atoms or an aromatic group having 6 to 20 carbon atoms,
R 7 =independently at each instance an alkyl group having 1 to 8 carbon atoms.
11. The curable composition according to claim 1 , wherein the catalyst comprises a catalyst that promotes a hydrolysis condensation mechanism.
12. The curable composition according to claim 1 , further comprising:
at least one additive selected from the group consisting of a plasticizer, a filler, an adhesion promoter, a rheology additive, a stabilizer, a catalyst, a solvent, a drying agent, and a chemical moisture drying agent.
13. The curable composition according to claim 1 , comprising:
1% by weight to 85% by weight of component A,
1% by weight to 50% by weight of component B,
0.01% by weight to 5% by weight of component C,
based on 100% by weight of the composition.
14. The curable composition according to claim 13 , further comprising:
0.1% by weight to 40% by weight of component D, which comprises at least one epoxy-functional compound and at least one amino-functional compound, based on the overall composition.
15. The curable composition according to claim 14 , wherein component D comprises 30% by weight to 95% by weight of the epoxy-functional compound and 0.1% by weight to 50% by weight of the amino-functional compound.
16. A coating, a paint, or a dye, comprising the curable composition according to claim 1 .
17. A method of reducing biofouling of a surface, the method comprising:
applying the coating, paint, or dye according to claim 16 to the surface.
18. A method of making a coating, a paint, or a dye, the method comprising:
adding the curable composition according to claim 1 to a coating, paint, or dye precursor composition.