HYBRID SILOXANE OLIGOMERS
A hybrid siloxane oligomer is shown and described herein. A hybrid siloxane oligomer comprises organosilicon units wherein the oligomer comprises organosilicon units with fluoro-functional groups, and organosilicon units with other reactive functionality. The oligomers can be employed to form a coating on a surface of an article to provide a hydrophobic and/or oleophobic surface coating, which may impart other beneficial properties to the article.
1 . A hybrid siloxane oligomer of the formula:
where R 1 , R 3 , R 5 , and R 7 are each independently selected from hydroxy, an alkoxy, an alkoxycarbonyl, a halide, an alkyl, an aralkyl, or an aromatic group, with the proviso that at least one of R 1 , R 3 , R 5 , and/or R 7 is an alkoxy, an alkoxycarbonyl, or a halide group;
R 2 is selected from hydrogen an alkyl, an aralkyl, or an aromatic group;
R 4 is selected from a fluoro-functional group;
R 6 and R 8 are each independently selected from an alkoxy, an alkoxycarbonyl, a halide, an alkyl, an aralkyl, an aromatic group, an epoxy, a hydroxy, an amine containing group, a mercapto containing group, a urea containing group, a thiourea containing group, and a urethane containing group;
Z 1 , Z 2 , and Z 3 are each independently selected from an organic linking group having 1-20 carbon atoms optionally containing heteroatoms, with the proviso that when R 6 or R 8 is an alkoxy, an alkoxycarbonyl, or a halide, then Z 2 or Z 3 , respectively, cannot be O, N, or S;
a is from greater than 0 to about 100, b and c are each independently 0 to about 100, a+b+c is greater than 0, and b+c is greater than 0.
2 . The siloxane oligomer of claim 1 , wherein R 4 is a fluoroaliphatic group of the formula C z H y F x where z is 1-20 and x+y is 2z+1 where x is 1 or greater.
3 . The siloxane oligomer of claim 2 , wherein R 4 is selected from —CF 3 , —C 2 F 5 , —C 3 F 7 , —C 4 F 9 , —C 5 F 11 , or —C 6 F 13 .
4 . The siloxane oligomer of claim 1 , wherein R 6 and R 8 are each independently selected from (i) an amine group selected from —NR 2 12 , —(NR 13 ) h —NR 14 R 15 , —NR 16 —C(X 1 )—NR 2 17 , —R 18 —N(R 19 )—R 20 , —R 21 —NR 2 22 , —R 23 —(N(R 24 )) i —R 25 —N 2 26 , or a combination of two or more thereof, where R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 19 , R 22 , R 24 , and R 26 are each independently selected from hydrogen, C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic, R 18 , R 20 , R 21 , R 23 , and R 25 are each independently selected from a divalent C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic group, X 1 is O or S, h is 1 to about 10, and i is 1 to about 10; (ii) an epoxy functional group selected from —R 29 -epoxy; or —R 30 —O—R 31 -epoxy, where R 29 , R 30 , and R 31 are each independently selected from a divalent C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic, or wherein R 29 and R 31 can optionally be a ring structure to form a C5-C20 cycloalkyl epoxy; and (iii) a thiol containing group selected from —SH, —SR 27 , —S—C(O)—R 28 , or a combination of two or more thereof, where R 27 and R 28 are each independently selected from a C1-C10 alkyl, a C6-C20 cycloalkyl, and a C6-C20 aromatic.
5 . The siloxane oligomer of claim 1 , wherein b is greater than 0 and R 6 is selected from
where R 29 , R 30 , and R 31 are each independently selected from a divalent C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic.
6 . The siloxane oligomer of claim 4 , wherein b is greater than 0, c is 0, and R 6 is —R 30 —O—R 31 -epoxy, where R 30 and R 31 are each independently selected from a divalent C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic.
7 . The siloxane of claim 1 , wherein b is greater than 0 and R 6 is selected from —NR 2 12 , —(NR 13 ) h —NR 14 R 15 , —NR 16 —C(X 1 )—NR 2 17 , —R 18 —N(R 19 )—R 20 , —R 21 —NR 2 22 , —R 23 —(N(R 24 )) i —R 25 —NR 2 26 , or a combination of two or more thereof, where R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 19 , R 22 , R 24 and R 26 are each independently selected from hydrogen, C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic, R 18 , R 20 , R 21 , R 23 , and R 25 are each independently selected from a divalent C1-C20 alkyl, a C6-C20 cycloalkyl, or a C6-C20 aromatic group, X 1 is O or S, h is 1 to about 10, and i is 1 to about 10.
8 . The siloxane of claim 7 , wherein R 6 is selected from —NH 2 , —N(CH 3 ) 2 , —NH—C(O)—NH 2 , —NH—C(S)—NH 2 , —(NH(C 2 H 4 )—) 2 NH 2 .
9 . The siloxane oligomer of claim 1 wherein b is greater than 0, c is 0, and R 6 is —NR 2 12 and R 12 is hydrogen or a C1-C20 alkyl.
10 . The siloxane oligomer of claim 1 , wherein b is greater than 0, c is 0, and R 6 is —R 18 —N(R 19 )—R 20 , or —R 23 —(N(R 24 )) i —R 25 —NR 2 26 where R 19 , R 22 , R 24 , and R 26 are each hydrogen, and R 18 , R 20 , and R 25 are each independently selected from a divalent C1-C20 alkyl
11 . The siloxane oligomer of claim 1 having a molar ratio of R 4 :(R 6 +R 8 ) of (i) from about 1:9 to about 9:1; (ii) from about 1:7 to about 7:1; (iii) from about 1:5 to about 5:1; (iv) from about from about 1:3 to about 3:1; (v) from about 1:2 to about 2:1; (vi) from about 1:1 to about 4:1; or (vii) from about 1.5:1 to about 3:1.
12 . The siloxane of claim 1 , wherein the siloxane has a number average molecular weight of from about 300 to about 10000.
13 . A composition comprising the siloxane oligomer of claim 1 dispersed in a carrier.
14 . The composition of claim 13 wherein the carrier is selected from an organic solvent.
15 . A coating formed from the composition of claim 13 .
16 . An article comprising a coating on a surface thereof, wherein the coating is formed from a composition of claim 14 .
17 . A method of preparing a siloxane oligomer of claim 1 comprising:
(i) reacting a silane of the formula (R 4 —Z1)Si(OR 3 ) 2 (OR 1 ) with a silane of the formula (R 6 —Z 2 )Si(OR 5 ) 3-n (OR 2 ) n and/or a silane of the formula (R 8 —Z 3 )Si(OR 7 ) 2 (OR 2 ) in the presence of a solvent and a catalyst;
(ii) removing water from the reaction mixture; and
(iii) removing volatile components from the reaction mixture.