COATED POLYESTER FILM

• US 20110209901A1
• Filed: 08/01/2008
• Published: 09/01/2011
• Est. Priority Date: 08/02/2007
• Status: Abandoned Application

• Current Assignee: DuPont Performance Elastomers L (Bristol-Myers Squibb Company)
• Original Assignee: DuPont Performance Elastomers L (Bristol-Myers Squibb Company)
• Inventors: MacKerron, Duncan Henry, Eveson, Robert W., Rakos, Karl, MacDonald, William A.
• Application Number:
  US12/671,648
• Publication Number:
  US 20110209901A1
• Time in Patent Office: Days
• US Class Current: 174/254
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• 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 2467/00 Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08J2477/12; of polyester-imides C08J2479/08; 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: H10K 77/111 Flexible substrates
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers

Abstract

A method of improving the flexibility of a coated polyester substrate for an electronic device comprising a coated polyester substrate layer and an electrode layer comprising conductive material, said method comprising: (a) providing a polyester film; and (b) disposing an organic/inorganic hybrid coating on one or both surfaces of said polyester film, wherein said coating is derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates; a solvent; and inorganic particles, and optionally further comprising a photoinitiator.

Claims

1. A method of improving the flexibility of a coated polyester substrate for an electronic device comprising a coated polyester substrate layer and an electrode layer comprising conductive material, said method comprising:

(a) providing a polyester film; and

(b) disposing an organic/inorganic hybrid coating on one or both surfaces of said polyester film,

wherein said coating is derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates;

a solvent; and

inorganic particles, and optionally further comprising a photoinitiator.

4. A method according to any preceding claim further comprising the step of disposing an electrode layer comprising conductive material on one or both surfaces of said coated polyester substrate layer.

5. A method according to any preceding claim, wherein the improvement in flexibility is such that the coated polyester substrate layer can be elongated in the transverse direction at a draw rate of 60 mm/min by 3% or more of its original dimension before a first crack appears in the coating of the coated polyester substrate.

6. A method according to any preceding claim, wherein the improvement in flexibility is such that the composite structure comprising said coated polyester substrate layer and electrode layer comprising conductive material can be elongated in the transverse direction at a draw rate of 60 mm/min by 3% or more of its original dimension before a first crack appears in the conductive material of the electrode layer.

7. A method according to any preceding claim, wherein the improvement in flexibility is such that the coated polyester substrate layer has a critical radius of curvature of about 10 mm or less.

8. A method according to any preceding claim, wherein the improvement in flexibility is such that the composite structure comprising said coated polyester substrate layer and electrode layer comprising conductive material has a critical radius of curvature of about 10 mm or less.

9. A method according to any preceding claim, wherein said inorganic particles have an average particle diameter of from about 0.005 to about 3 μ

m.

15. A method or device according to any preceding claim, wherein the electronic device is an electronic display.

16. A method or device according to claim 15 wherein the electronic display is a rollable electronic display.

17. A method or device according to any one of claims 1 to 14, wherein the electronic device is a photovoltaic cell.

18. A method or device according to any one of claims 1 to 14, wherein the electronic device is a semiconductor device.

19. A method or device according to claim 18, wherein the semiconductor device is a transistor.

20. A method or device according to any one of claims 1 to 14, wherein the electronic device is a sensor.

24. A method, device or film according to any preceding claim, wherein said inorganic particles are preferably present in an amount of from about 5% to about 60% by weight of the solids components of the coating composition.

25. A method, device or film according to any preceding claim, wherein said inorganic particles are selected from silica and metal oxides.

26. A method, device or film according to any preceding claim wherein said coating composition is UV-curable.

27. A method, device or film according to any preceding claim wherein said coating is derived from a UV-curable composition comprising monomeric acrylates, silica particles and a photoinitiator.

28. A method according to claim 27, wherein the organic/inorganic hybrid coating composition comprises two different monomeric acrylates.

29. A method, device or film according to any preceding claim wherein said coating layer has a dry thickness of from 1 to 20 microns.

30. A method, device or film according to any preceding claim wherein the coated polyester substrate layer exhibits a surface having an Ra value of less than 0.7 nm and/or an Rq value of less than 0.9 nm.

31. A method, device or film according to any preceding claim wherein the electrode layer is a patterned layer of a conductive material.

32. A method, device or film according to any preceding claim wherein the conductive material of the electrode layer is selected from gold, silver, aluminium platinum, palladium, nickel and indium tin oxide.

33. A method, device or film according to any preceding claim wherein said polyester is poly(ethylene naphthalate) or poly(ethylene terephthalate).

34. A method, device or film according to claim 33 wherein said polyester is derived from 2,6-naphthalenedicarboxylic acid.

35. A method, device or film according to claim 33 or 34 wherein the poly(ethylene naphthalate) has an intrinsic viscosity of 0.5-1.5.

36. A method, device or film according to any preceding claim, wherein the polyester substrate or film is a biaxially oriented polyester film.

37. A method, device or film according to any preceding claim wherein said polyester substrate or film is a heat-stabilised, heat-set, biaxially oriented polyester film.

38. A method, device or film according to claim 37, wherein said heat-stabilised, heat-set, biaxially oriented polyester film exhibits one or more of:

(i) a shrinkage at 30 mins at 230°

C. of less than 1%;

(ii) a residual dimensional change Δ

L_T measured at 25°

C. before and after heating the film from 8°

C. to 200°

C. and then cooling to 8°

C., of less than 0.75%; and

/or

(iii) a coefficient of linear thermal expansion (CLTE) within the temperature range from −

40°

C. to +100°

C. of less than 40×

10<sup>−

6</sup>/°

C.

2. A method of improving the flexibility of an electronic device comprising a coated polyester substrate layer and an electrode layer comprising conductive material, said method comprising:

(a) providing a polyester film;

(b) disposing an organic/inorganic hybrid coating on one or both surfaces of said polyester film; and

(c) providing the coated polyester film as a substrate in the electronic device,

wherein said coating is derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates;

a solvent; and

inorganic particles, and optionally further comprising a photoinitiator

3. A method of improving the flexibility of an electronic device comprising a coated polyester substrate layer and an electrode layer comprising conductive material, said method comprising:

(a) selecting the polyester substrate to be a polyester film coated on one or both surfaces thereof with an organic/inorganic hybrid coating which is derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates;

a solvent; and

inorganic particles, and optionally further comprising a photoinitiator; and

(b) providing said film as a substrate in the electronic device.

10. A flexible electronic device comprising a polyester substrate and an electrode layer comprising a conductive material, and further comprising on one or both surfaces of said polyester substrate an organic/inorganic hybrid coating derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates;

a solvent; and

inorganic particles, and optionally further comprising a photoinitiator, wherein said inorganic particles have an average particle diameter of from about 0.005 to about 3 μ

m.

11. An electronic device according to claim 10, wherein the flexibility of the electronic device is such that the composite structure comprising said coated polyester substrate layer and electrode layer comprising conductive material can be elongated in the transverse direction at a draw rate of 60 mm/min by 3% or more of its original dimension before a first crack appears in the conductive material of the electrode layer.

12. An electronic device according to claim 10 or claim 11, which is rollable.

13. An electronic device according to claim 12, wherein the flexibility of the electronic device is such that the composite structure comprising the coated polyester substrate layer and electrode layer comprising conductive material has a critical radius of curvature of about 10 mm or less.

14. A method of manufacture of a rollable electronic display comprising a coated polyester substrate layer and an electrode layer comprising conductive material, said method comprising:

(a) providing a polyester film; and

(b) disposing a coating on one or both surfaces of said polyester film, characterised in that said coating is an organic/inorganic hybrid coating derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates;

a solvent; and

inorganic particles, and optionally further comprising a photoinitiator,

(c) disposing an electrode layer comprising conductive material on one or both surfaces of said coated polyester film;

and further characterised in that the composite structure comprising said coated polyester substrate layer and electrode layer can be elongated in the transverse direction at a draw rate of 60 mm/min by 3% or more of its original dimension before a first crack appears in the conductive material of the electrode layer, and/or in that the composite structure comprising the coated polyester substrate layer and electrode layer has a critical radius of curvature of about 10 mm or less.

21. A composite film comprising:

(i) a biaxially oriented polyester substrate;

(ii) a primer layer coated on one or both surfaces of the polyester substrate;

(iii) on one or both surfaces of said primer-coated polyester substrate, an organic/inorganic hybrid coating derived from a coating composition comprising a low molecular weight reactive component selected from monomeric acrylates and/or an unsaturated oligomeric component selected from acrylates, polyether acrylates, epoxy acrylates and polyester acrylates;

a solvent; and

inorganic particles, and optionally further comprising a photoinitiator, wherein said inorganic particles have an average particle diameter of from about 0.005 to about 3 μ

m; and

(iv) optionally on a surface of the coated substrate an electrode layer comprising a conductive material.

22. A composite film according to claim 21, wherein the primer layer is an acrylic resin.

23. A composite film according to claim 21, wherein the primer layer is a polyester resin.