Perfluoropolyether urethane additives having (meth)acryl groups and hard coats

1. An optical display comprising:

an optical substrate having a surface layer comprising the reaction product of a mixture comprising

i) a hydrocarbon-based hardcoat composition;

ii) at least one perfluoropolyether urethane having the formula:

R i —(NHC(O)XQR f ) m ,—(NHC(O)OQ(A) p ) n ; wherein

R i is the residue of a multi-isocyanate;

X is O, S or NR, wherein R is H or an alkyl group having 1 to 4 carbon;

R f is a monovalent perfluoropolyether moiety comprising groups of the formula F(R fc O) x C d F 2d —, wherein each R fc is independently a fluorinated alkylene group having from 1 to 6 carbon atoms, each x is an integer greater than or equal to 2, and wherein d is an integer from 1 to 6;

each Q is independently a connecting group having a valency of at least 2;

A is a (meth)acryl functional group —XC(O)C(R 2 )═CH 2 wherein R 2 is an alkyl group of 1 to 4 carbon atoms or H or F;

m is at least 1; n is at least 1; p is 2 to 6; m+n is 2 to 10; wherein each group having subscripts m and n is attached to the R i unit.

2. The optical display of claim 1 wherein the perfluoropolyether moiety is F(CF(CF 3 )CF 2 O) a CF(CF 3 )— and a ranges from 4 to 15.

3. The optical display of claim 1 with the proviso that when X is O, Q is not methylene.

4. The optical display of claim 1 wherein X is S or NR.

5. The optical display of claim 1 wherein Q is an alkylene having at least two carbon atoms.

6. The optical display of claim 1 wherein Q is a straight chain, branched chain, or cycle-containing connecting group.

7. The optical display of claim 6 wherein Q is selected from the group consisting of a covalent bond; an arylene; an aralkylene; and alkarylene.

8. The optical display of claim 6 wherein Q comprises a heteroatom selected from O, N, and S.

9. The optical display of claim 6 wherein Q comprises a heteroatom-containing functional group selected from carbonyl and sulfonyl.

10. The optical display of claim 6 wherein Q is a straight chain alkylene group comprising heteroatoms selected from O, N, S; a heteroatom-containing functional group selected from carbonyl and sulfonyl, and combinations thereof.

11. The optical display of claim 6 wherein Q is branched chain or cycle-containing alkylene group.

12. The optical display of claim 6 wherein Q is a straight chain alkylene group comprising heteroatoms selected from O, N, S; a heteroatom-containing functional group selected from carbonyl and sulfonyl, and combinations thereof.

13. The optical display of claim 6 wherein Q is a nitrogen containing group.

14. The optical display of claim 13 wherein Q contains an amide group.

15. The optical display of claim 1 , wherein said perfluoropolyether urethane comprises:

wherein the HFPO is F(CF(CF 3 )CF 2 O) n CF(CF 3 )— and a ranges from 2 to 15.

16. The optical display of claim 1 , wherein the mixture further comprises iii) at least one fluorinated compound having at least one moiety selected from fluoropolyether, fluoroalkyl, and fluoroalkylene linked to at least one free-radically reactive group with a non-urethane linking group.

17. The optical display of claim 1 , wherein the mixture comprises surface modified inorganic oxide particles.

18. The optical display of claim 17 , wherein the surface modified inorganic oxide particles comprises silica nanoparticles.

19. The optical display of claim 1 , wherein m is at least 3.

20. The optical display of claim 16 wherein the connecting group, Q, is selected from

a) divalent group selected from an alkylene, arylene, or combinations thereof, optionally comprising a divalent group selected from carbonyl, carbonyloxy, carbonylimino, sulfonamido, and combinations thereof;

b) a sulfur-containing heteroalkylene group containing a divalent group selected from carbonyl, ester, amide, thioester or sulfonamido, and combinations thereof;

c) an oxygen-containing heteralkylene group containing a divalent group selected from carbonyl, ester, thioester, sulfonamido, and combinations thereof; and

d) a nitrogen-containing heteroalkylene group containing a divalent group selected from carbonyl, amide, thioester, or sulfonamido, and combinations thereof.

21. The optical display of claim 16 wherein iii) has a lower molecular weight than ii).

22. The optical display of claim 16 wherein iii) has a ratio of fluorine atom to non-fluorine atoms that is higher than ii).

23. The optical display of claim 16 wherein iii) is a perfluoropolyether (meth)acrylate compound.