Antistatic article, method of making the same, and display device having the same

• US 9,260,612 B2
• Filed: 04/24/2013
• Issued: 02/16/2016
• Est. Priority Date: 07/23/2007
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Pellerite, Mark J., Ali, Mahfuza B., Haus, Eileen M., King, Gregory F., Lockridge, James E., Loi, Hang K., Peterson, Jeffrey A.
• Primary Examiner(s): KHAN, TAHSEEN
• Application Number:
  US13/869,402
• Publication Number:
  US 20130236702A1
• Time in Patent Office: 1,028 Days
• Field of Search: 428/212, 428/336, 428/412, 428/473.5, 428/474.4, 428/480, 428/500, 264/291, 525/222, 525/55, 526/288, 526/312
• US Class Current: 1/1
• CPC Class Codes: C08J 2433/00 Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Derivatives of such polymers
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/044 Forming conductive coatings; Forming coatings having anti-static properties
• CPC Class Codes: C09D 5/00 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 Class Codes: C09K 3/16 Anti-static materials
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 1/16 having an anti-static effect, e.g. electrically conducting coatings
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B
• CPC Class Codes: G02F 2202/22 Antistatic materials or arrangements
• CPC Class Codes: G03C 1/89 Macromolecular substances therefor
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31721 Of polyimide
• CPC Class Codes: Y10T 428/31725 Of polyamide
• CPC Class Codes: Y10T 428/3175 Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31797 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31891 : Where addition polymer is an ester or halide
• CPC Class Codes: Y10T 428/31913 : Monoolefin polymer
• CPC Class Codes: Y10T 428/31928 : Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31935 : Ester, halide or nitrile of addition polymer

Abstract

An antistatic article having an antistatic layer disposed on a substrate is disclosed herein. The antistatic layer is formed from a cationic copolymer, a non-cationic (meth)acrylic polymer, and a crosslinking agent. The cationic copolymer consists essentially of a cationic monomer, a hydrophobic monomer, a crosslinkable monomer, and an optional nitrogen-containing monomer. The substrate may comprise an optical film such as a multilayer optical film. Methods for making the antistatic article and display devices containing the antistatic article are also disclosed.

Claims

1. An article comprising:

A) a substrate; and

B) an antistatic layer disposed on the substrate, the antistatic layer comprising;

a) a cationic copolymer consisting essentially of;

i) from about 20 to about 50 wt % of a cationic monomer having the formula;

CH₂═

CR¹COZ(CH₂)_nN(R²)₃X

wherein

Z is O, S, or NH;

R¹ is H or CH₃;

R² independently comprises an alkyl group having from 1 to 4 carbon atoms;

X is an anion selected from the group consisting of halogen, nitrate, alkylsulfate, alkanesulfonate, and haloalkanesulfonate; and

n=2 to 6; and

ii) from about 10 to about 75 wt % of a hydrophobic monomer comprising an aliphatic alkyl (meth)acrylate monomer having a hydrocarbon group of from 1 to 12 carbon atoms;

iii) from about 0.5 to about 55 wt % of a nitrogen-containing monomer selected from N-vinylpyrrolidinone, N,N-dimethylaminoethyl (meth)acrylate, or a combination thereof;

with the proviso that the amount of cationic monomer and nitrogen-containing monomer is less than about 70 wt %; and

iv) from about 2 to about 25 wt % of a crosslinkable monomer comprising (meth)acrylic acid or a monomer having the formula;

CH₂═

CR³Y

wherein

R³ is H or CH₃; and

Y is selected from the group consisting of CO₂M, L-CO₂M, L-OH, and CONH₂, wherein M is H or a counterion, and L is a divalent linking group comprising alkylene, arylene, heteroalkylene, ether, carbonyl, ester, amido, or sulfonamido functionality, or a combination thereof;

b) a non-cationic (meth)acrylic polymer which comprises no monomer with —

OH or —

CO₂H functional groups; and

c) a crosslinking agent selected from the group consisting of melamine-formaldehyde, urea-formaldehyde, glycoluril-formaldehyde, aziridine, carbodiimide, isocyanate, and epoxy crosslinkers.

2. The article of claim 1,

the cationic monomer comprising an alkyl salt of dimethylaminoethyl acrylate;

the hydrophobic monomer comprising ethyl (meth)acrylate, methyl (meth)acrylate, butyl (meth)acrylate, iso-octyl (meth)acrylate, iso-bornyl (meth)acrylate, phenoxyethyl (meth)acrylate, or a combination thereof; and

the crosslinkable monomer comprising hydroxyethyl (meth)acrylate.

3. The article of claim 1, the non-cationic (meth)acrylic polymer comprising an alkyl (meth)acrylate copolymer or an acrylic core/shell copolymer.

4. The article of claim 1, the antistatic layer comprising:

from about 25 to about 70 wt. % of the cationic copolymer;

from about 10 to about 50 wt. % of the non-cationic (meth)acrylic polymer; and

from about 5 to about 35 wt. % of the crosslinking agent.

5. The article of claim 1, the antistatic layer having a thickness of from about 50 to about 400 nm.

6. The article of claim 1, having a charge decay time of less than about 10 sec at 40% relative humidity.

7. The article of claim 1, having a charge decay time of less than about 10 sec at 20% relative humidity.

8. The article of claim 1, having a haze value of less than about 20%.

9. The article of claim 1, the substrate comprising polyethylene terephthalate, polyethylene naphthalate, cellulose triacetate, polypropylene, polyester, polycarbonate, polymethylmethacrylate, polyimide, polyamide, or a blend thereof.

10. The article of claim 1, the substrate comprising a reflective film, a polarizer film, a reflective polarizer film, a diffuse blend reflective polarizer film, a diffuser film, a brightness enhancing film, a turning film, a mirror film, or a combination thereof.

11. The article of claim 1, the substrate comprising a multilayer optical film having alternating layers of first and second optical layers, wherein the first and second optical layers have refractive indices along at least one axis that differ by at least 0.04.

12. The article of claim 1, further comprising a microstructured layer disposed on the antistatic layer, wherein the microstructured layer comprises a structured surface having a plurality of microstructures, and the structured surface comprises an outer surface of the article.

13. The article of claim 1, wherein the article is a reflective film, a polarizer film, a reflective polarizer film, a diffuse blend reflective polarizer film, a diffuser film, a brightness enhancing film, a turning film, a mirror film, or a combination thereof.

14. The article of claim 1 wherein the cationic copolymer consists essentially of at least about 5 wt % of the nitrogen-containing monomer selected from N-vinylpyrrolidinone, N,N-dimethylaminoethyl (meth)acrylate, or a combination thereof.

15. A method of making an article, comprising:

A) coating an antistatic composition on a substrate thereby forming a coated substrate, the antistatic composition comprising;

a) a cationic copolymer consisting essentially of;

i) from about 20 to about 50 wt % of a cationic monomer having the formula;

CH₂═

CR¹COZ(CH₂)_nN(R²)₃X

wherein

Z is O, S, or NH;

R¹ is H or CH₃;

R² independently comprises an alkyl group having from 1 to 4 carbon atoms;

X is an anion selected from the group consisting of halogen, nitrate, alkylsulfate, alkanesulfonate, and haloalkanesulfonate; and

n=2 to 6; and

ii) from about 10 to about 75 wt % of a hydrophobic monomer comprising an aliphatic alkyl (meth)acrylate monomer having a hydrocarbon group of from 1 to 12 carbon atoms;

iii) from about 0.5 to about 55 wt % of a nitrogen-containing monomer selected from N-vinylpyrrolidinone, N,N-dimethylaminoethyl (meth)acrylate, or a combination thereof with the proviso that the amount of cationic monomer and nitrogen-containing monomer is less than about 70 wt %; and

iv) from about 2 to about 25 wt % of a crosslinkable monomer comprising (meth)acrylic acid or a monomer having the formula;

CH₂═

CR³Y

wherein

R³ is H or CH₃; and

Y is selected from the group consisting of CO₂M, L-CO₂M, L-OH, and CONH₂, wherein M is H or a counterion, and L is a divalent linking group comprising alkylene, arylene, heteroalkylene, ether, carbonyl, ester, amido, or sulfonamido functionality, or a combination thereof;

b) a non-cationic (meth)acrylic polymer which comprises no monomer with —

OH or —

CO₂H functional groups; and

c) a crosslinking agent selected from the group consisting of melamine-formaldehyde, urea-formaldehyde, glycoluril-formaldehyde, aziridine, carbodiimide, isocyanate, and epoxy crosslinkers;

B) optionally stretching the coated substrate in at least one direction.

16. The method of claim 15 wherein the cationic copolymer consists essentially of at least about 5 wt % of the nitrogen-containing monomer selected from N-vinylpyrrolidinone, N,N-dimethylaminoethyl (meth)acrylate, or a combination thereof.