Fluoropolymer coating compositions with multifunctional fluoroalkyl crosslinkers for anti-reflective polymer films

• US 20050182199A1
• Filed: 12/30/2004
• Published: 08/18/2005
• Est. Priority Date: 12/06/2000
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Klun, Thomas P., Schultz, William J., Jing, Naiyong, Qiu, Zai-Ming, Fukushi, Tatsuo, Cao, Chuntao, Walker, Christopher B. Jr., Tatge, Timothy J.
• Granted Patent: US 7,351,471 B2
• Time in Patent Office: Days
• US Class Current: 525/326.300
• CPC Class Codes: G02B 1/111 using layers comprising organic materials
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component

Abstract

An economic, optically transmissive, stain and ink repellent, durable low refractive index fluoropolymer composition for use in an antireflection film or coupled to an optical display. In one aspect of the invention, the composition is formed from the reaction product of a fluoropolymer and a fluoroalkyl containing multi-olefinic crosslinker. In another aspect of the invention, the composition further includes surface modified inorganic nanoparticles.

Claims

1. A low refractive index composition for use in an antireflection coating for an optical display, the composition comprising the reaction product of:

a fluoropolymer; and

a fluoroalkyl-containing multi-olefinic crosslinker.

2. The composition of claim 1, wherein said fluoropolymer is selected from the group consisting of a TFE copolymer, a HFP copolymer, THV, and FKM.

3. The composition of claim 2, wherein said fluoropolymer comprises a fluoroelastomer.

4. The composition of claim 3, said fluoroelastomer is selected from the group consisting of a Cl-containing fluoroelastomer, Br-containing fluoroelastomer, an I-containing fluoroelastomer, and a CN-containing fluoroelastomer.

5. The composition of claim 1, wherein said fluoroalkyl-containing multi-olefinic crosslinker comprises a perfluoropolyether multi-acrylate crosslinker.

6. The composition of claim 5, wherein said perfluoropolyether multi-acrylate crosslinker comprises an HFPO-multiacrylate crosslinker.

7. The composition of claim 1, wherein said fluoroalkyl-containing multi-olefinic crosslinker comprises a mono- or multi- (meth)acryl compound bearing at least one monovalent C1 to C8 fluoroalkyl moiety.

8. The composition of claim 1, wherein said fluoroalkyl-containing multi-olefinic crosslinker comprises a mono- or multi- (meth)acryl compound bearing at least one monovalent C1 to C8 fluoroalkylene moiety.

9. The composition of claim 1 further comprising a plurality of surface modified inorganic nanoparticles.

10. The composition of claim 1 further comprising one or more multi-olefinic compounds bearing at least one monovalent poly(hexafluoropropylene oxide) (HFPO) moiety.

11. The composition of claim 10 further comprising a compatibilizer selected from the group consisting of a fluoroalkyl-substituted monoacrylate, a fluoroalkyl-substituted multiacrylate, a fluoroalkylene-substituted monoacrylate and a fluoroalkylene-substituted multi-acrylate.

12. The composition of claim 11, wherein said compatibilizer is selected from the group consisting of C₄F₉SO₂N(CH₃)CH₂CH₂OC(O)CH═

CH₂, C₄F₉SO₂N(CH₂CH₂OC(O)CH═

CH₂)₂, and C₄F₉SO₂N(CH₃)CH₂CH₂OC(O)C(CH₃)═

CH₂.

13. The composition of claim 11, wherein said compatibilizer comprises a thiol or a polythiol compatibilizer.

14. The composition of claim 13, wherein said thiol or polythiol compatibilizer is selected from the group consisting of C₄F₉SO₂N(CH₃)CH₂CH₂OC(O)CH₂SH, C₄F₉SO₂N(CH₃)CH₂CH₂OC(O)CH₂CH₂SH, C₄F₉SO₂N(CH₃)CH₂CH₂SH, and C₄F₉SO₂N(CH₃)CH(OC(O)CH₂SH)CH₂OC(O)CH₂SH.

15. The composition of claim 10, wherein said mono- or multi- (meth)acryl compound bearing at least one monovalent hexafluoropolypropylene oxide moiety has the chemical formula:

R_fpeQ(X)_n,

wherein R_fpe is a residue of a monovalent HFPO moiety;

wherein Q is a connecting group selected from the group consisting of an alkylene group, an arylene group, an arylene-alkylene group, and an alkylene-arylene group;

wherein X is a free-radically reactive group selected from the group consisting of a meth(acryl) reactive group, an allyl reactive group, and a vinyl reactive group; and

wherein n is 2 to 3.

16. The composition of claim 15, wherein Q is selected from the group consisting of—

(CH₂)_m—

;

—

CH₂O(CH₂)₃—

; and

—

C(O)NRCH₂CH₂—

, where R is an H or lower alkyl of 1 to 4 carbon atoms and m is 1 to 6.

17. An antireflection film having a layer of said low refractive index material of claim 1, said antireflection film further comprising a high refractive index layer coupled to said layer of said low refractive index material.

18. An optical device comprising a layer of said low refractive index material formed according to claim 1.

19. A low refractive index composition for use in an antireflection coating for an optical display, the composition comprising the reaction product of:

a fluoropolymer;

a fluoroalkyl-containing multi-olefinic crosslinker; and

a plurality of surface modified nanoparticles.

20. A method for forming an optically transmissive, stain and ink repellent, durable optical display comprising:

providing an optical display having an optical substrate;

forming a low refractive index polymer composition comprising a fluoropolymer and a fluoroalkyl-containing multi-olefinic crosslinker;

applying a layer of said low refractive index polymer composition to said optical substrate; and

curing said layer to form a cured film.

21. The method of claim 20, wherein providing an optical display comprises provided an optical display having a hard coat layer applied to an optical substrate.

22. The method of claim 20, wherein forming a low refractive index polymer composition comprises reactively coupling a fluoropolymer and a fluoroalkyl-containing multifunctional olefinic crosslinker.