Fluoroalkylsilanes and coatings therefrom

Patent metadata

Field	Value
Publication number	US-9938306-B2
Application number	US-201415023748-A
Country	US
Kind code	B2
Filing date	Sep 23, 2014
Priority date	Oct 4, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Novel fluoroalkysilanes of the following formula are described; R f —O—CHFCF 2 —O—(CH 2 ) n —Si(R) x X 3−x , wherein R f is a perfluoroalkyl group, optionally substituted by one or more in-chain -Q-, —S— or —NR f1 -heteroatoms, where R f 1 is a -perfluoroalkyl; X is a hydrolysable group; R is a C 1 C 4 alkyl group; n is at least 3; and x is 1 to 3.

First claim

What is claimed is:

1. A coating composition comprising a fluoroalkyl silane of the formula
R f —O—CHFCF 2 —O—(CH 2 ) q —Si(X) x R 3−x ,

wherein
R f is a perfluoroalkyl group, optionally substituted by one or more in-chain —O—, —S— or —NR f 1 — heteroatoms, where R f 1 is a perfluoroalkyl;
X is a hydrolysable group;
R is a C 1 -C 4 alkyl group;
q is at least 3; and
x is 1 to 3;
a solvent, optional acid catalyst, and silica.

2. The fluoroalkylsilane of claim 1 wherein R f is a C 1 -C 6 perfluoroalkyl group.

3. The fluoroalkylsilane of claim 1 wherein q is at least 6.

4. The fluoroalkylsilane of claim 1 wherein R f is of the formula C n F 2n+1 —(O—C m F 2m ) p —, where n is at least 1, m is at least 2, and p may be zero or a number from 1 to 10.

5. The fluoroalkylsilane of claim 1 wherein R f is of the formula C n F 2n+1 N(C 2o F 2o+1 )—C m F 2m —, where n is at least 1, o is at least 1 and m is at least 2.

6. The fluoroalkylsilane of claim 5 wherein each of subscripts n and m are 3 to 6.

7. The fluoroalkylsilane of claim 1 where R f is selected from CF 3 , C 2 F 5 , C 3 F 7 and CF 3 O(CF 2 ) 3 ; q is 6 and greater and X is selected from Cl, OCH 3 , OCH 2 CH 3 , OCH 2 CH 2 CH 3 and OCH(CH 3 ) 2 .

8. The coating composition of claim 1 further comprising one or more silane crosslinkers of the formula:
Si(X 1 ) z R 2 4−z

wherein each X 1 is independently hydroxyl, a hydrolyzable group, or a combination thereof; each R 2 is independently a C 1 -C 4 alkyl group; z is an integer of one to four.

9. The coating composition of claim 8 wherein z is four.

10. The coating composition of claim 8 comprising a mixture of silane crosslinkers where z is 3 and 4.

11. The coating composition of claim 8 comprising 1 to 20 weight percent of silane crosslinkers.

12. The coating composition of claim 1 comprising:
a) 0.25 to 10 wt. % fluoroalkyl silane
b) 1 to 20 wt. % silica
c) 1 to 20 wt. % a silane crosslinker,
d) 0.01 to 10 wt. % of an acid catalyst;
in an organic solvent.

13. A coated article comprising a substrate and a cured coating of the coating composition of claim 1 on a surface thereof.

14. The coated article of claim 13 wherein the coating is of the general formula:
[R f 2 SiO 3/2 ] a [SiO 4/2 ] b [RSiO 3/2 ] c ,
where
R f 2 is R f —O—CHFCF 2 —O—(CH 2 ) q —,
[SiO 4/2 ] are units derived from crosslinking silanes having four hydrolysable groups;
[RSiO 3/2 ] are units derived from crosslinking silanes having three hydrolysable groups, and subscripts a, b and c are numbers corresponding to the weight percents of each unit, and each R is independently a C 1 -C 4 alkyl group.

15. The coated article of claim 13 wherein the substrate is siliceous.

Assignees

• 3M Innovative Properties Co

Inventors

• Qiu Zai-Ming
• Rathore Jitendra S

Classifications

• C07F7/1804 Primary

  Compounds having Si-O-C linkages (Si-O-acyl linkages C07F7/1896) · CPC title

• C09D183/08

  containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen · CPC title

• C08G77/24

  halogen-containing groups · CPC title

• C09D5/00

  Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced {(electrically insulating plastics, resins or waxes H01B3/30)}; Filling pastes · CPC title

• C08K3/36

  Silica · CPC title