Optical films comprising phenyl ethylene (meth)acrylate monomers

1. An optical film wherein the film comprises a polymerized microstructured surface comprising the reaction product of a polymerizable resin composition comprising at least one (meth)acrylate monomer comprising a phenyl ethylene group, wherein the (meth)acrylate monomer has a refractive index of at least 1.54 and a structure is selected from:

A)

wherein

R is an optional substituent;

t ranges from 0 to 5;

R3 is H or a substituent;

L is a C2-C12 alkyl group optionally substituted with one or more hydroxyl groups;

n ranges from 0 to 10; and

R1 is H or CH 3 ;

or B)

wherein

R4 is a substituent comprising a (meth)acrylate group, p independently ranges from 0 to 2 provided one p is at least 1;

R is an optional substituent;

t ranges from 0 to 5; and

R3 is H or a substituent.

2. The optical film according to claim 1 wherein the (meth)acrylate monomer has a refractive index of at least 1.60.

3. The optical film according to claim 1 wherein the (meth)acrylate monomer has a viscosity of less than 100 cps at 25° C.

4. The optical film of claim 1 wherein t is 0.

5. The optical film of claims 1 wherein R3 is H.

6. The optical film of claim 1 wherein the (meth)acrylate monomer has the structure A and R3 is independently selected from a C2-C12 alkyl group, halogen, alkyaryl, an ether group, and a nitro group.

7. The optical film of claim 1 wherein n is 0.

8. The optical film of claim 1 wherein the (meth)acrylate monomer has the structure B and R3 is independently selected from a C2-C12 alkyl, a halogen, and an ether group.

9. The optical film of claim 1 wherein the (meth)acrylate monomer has the structure B and R4 is selected from the group consisting of

wherein

L is a C2-C12 alkyl group optionally substituted with one or more hydroxyl groups;

n ranges from 0 to 10; and

R1 is H or CH 3 .

10. The optical film of claim 1 wherein the monomer is a mono(meth)acrylate monomer.

11. The optical film of claim 1 wherein the polymerizable resin composition comprises one or more aromatic monomers or oligomers having at least two aromatic groups and at least two (meth)acrylate groups.

12. The optical film of claim 11 wherein the polymerizable resin comprises 25 wt-% to 75 wt-% of the aromatic monomers or oligomers having at least two aromatic groups and at least two (meth)acrylate groups.

13. The optical film of claim 11 wherein the aromatic monomer or oligomer having at least two aromatic groups and at least two polymerizable (meth)acrylate groups has a molecular weight of at least 350 g/mole.

14. The optical film of claim 11 wherein the aromatic monomer or oligomer has the structure

wherein

R1 is independently hydrogen or methyl;

Z is independently —C(CH 3 ) 2 —, —CH 2 —, —C(O)—, —S—, —S(O)—, or —S(O) 2 —;

Q is independently O or S;

L is independently a C 2 -C 6 alkyl group optionally substituted with one or more hydroxy groups; and

and n ranges from 0 to 10.

15. The optical film of claim 11 wherein the aromatic monomer or oligomer has the structure

wherein

each R1 is independently H or methyl;

each R2 is independently Br;

m ranges from 0 to 4;

each Q is independently O or S;

n ranges from 0 to 10;

L is independently a C2 to C12 alkyl group optionally substituted with one or more hydroxyl groups;

z is an aromatic ring; and

t is independently 0 or 1.

16. The optical film of claim 1 wherein the polymerizable resin composition is non-halogenated.

17. The optical film of claim 1 wherein the optical film is a brightness enhancing film having a single sheet gain of at least 1.59.

18. The optical film of claim 1 wherein the polymerizable resin composition comprises inorganic nanoparticles.