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

Patent metadata

Field	Value
Publication number	US-9260612-B2
Application number	US-201313869402-A
Country	US
Kind code	B2
Filing date	Apr 24, 2013
Priority date	Jul 23, 2007
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

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.

First claim

What is claimed is:

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:
CH 2 ═CR 1 COZ(CH 2 ) n N(R 2 ) 3 X

wherein
Z is O, S, or NH;
R 1 is H or CH 3 ;
R 2 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:
CH 2 ═CR 3 Y

wherein
R 3 is H or CH 3 ; and
Y is selected from the group consisting of CO 2 M, L-CO 2 M, L-OH, and CONH 2 , 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 —CO 2 H 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:
CH 2 ═CR 1 COZ(CH 2 ) n N(R 2 ) 3 X

wherein
Z is O, S, or NH;
R 1 is H or CH 3 ;
R 2 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:
CH 2 ═CR 3 Y

wherein
R 3 is H or CH 3 ; and
Y is selected from the group consisting of CO 2 M, L-CO 2 M, L-OH, and CONH 2 , 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 —CO 2 H 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.

Assignees

• 3M Innovative Properties Co

Inventors

• Pellerite Mark J
• Ali Mahfuza B
• Haus Eileen M
• King Gregory F
• Lockridge James E
• Loi Hang K
• Peterson Jeffrey A

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• Y10T428/31725

  Of polyamide · CPC title

• G03C1/89

  Macromolecular substances therefor · CPC title

• Y10T428/24612

  Composite web or sheet · CPC title

• G02F2202/22

  Antistatic materials or arrangements · CPC title