Multilayered polymer films with recyclable or recycled layers

• US 6,569,515 B2
• Filed: 01/13/1998
• Issued: 05/27/2003
• Est. Priority Date: 01/13/1998
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Liu, Yaoqui Joe, Hebrink, Timothy J., Nerad, Bruce A., Merrill, William W.
• Primary Examiner(s): Thibodeau, Paul
• Assistant Examiner(s): Kruer, Kevin R
• Application Number:
  US09/006,456
• Publication Number:
  US 20020025444A1
• Time in Patent Office: 1,960 Days
• Field of Search: 359/494, 359/584, 359/580, 428/480, 428/212, 428/903.3, 428/412, 428/520, 264/37.32, 264/37.33, 264/1.1, 264/1.7, 264/911, 264/920, 264/921, 427/359, 427/102, 427/163.1
• US Class Current: 428/212
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/023 Optical properties
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• 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 428/31928 Ester, halide or nitrile of addition polymer

Abstract

A multilayered polymer film is formed with a stack of one or more first optical layers, one or more second optical layers, and one or more non-optical layers. These optical and non-optical layers are typically made using polymer materials, such as polyesters. In one embodiment, the non-optical layers are made from a polyester having a composition which corresponds to the average molar composition of the combination of all of the first and second optical layers. Using this formulation, scrap material from the manufacture of multilayered polymer films may be used to generate the non-optical layers in subsequent films. Alternatively, the non-optical layers of a multilayered polymer film are made using scrap material from prior-manufactured multilayered polymer films with the optional addition of other polymer material which may be either new or recycled.

Claims

1. A multilayered optical film, comprising:

a stack of layers comprising

one or more first optical layers comprising a birefringent first polymer;

one or more second optical layers comprising a second polymer; and

one or more non-optical layers comprising polymer material;

wherein the first polymer comprises first monomer subunits and the second polymer comprises second monomer subunits different from the first monomer subunits, and the polymer material of the one or more non-optical layers comprises the first and second monomer subunits, based on total monomer subunits, in the same relative molar proportions as the molar proportions of the first and second monomer subunits in a combination of all the first and second optical layers of the multilayered polymer film.

2. The multilayered optical film of claim 1, wherein the polymer material of the one or more non-optical films is recycled from one or more prior-manufactured multilayered polymer films.

3. The multilayered optical film of claim 1, wherein at least one of the one or more non-optical layers is disposed over the stack.

4. The multilayered optical film of claim 1, wherein at least one of the one or more non-optical layers is disposed within the stack.

5. The multilayered optical film of claim 1, wherein the first polymer is a polyester, a polycarbonate, a polyacrylate, polystyrene, polyphenylene oxide, or a combination thereof.

6. The multilayered optical film of claim 1, wherein the first polymer is a first polyester and the second polymer is a second polyester.

7. The multilayered optical film of claim 6, wherein the first monomer subunits are first glycol subunits and the second monomer subunits are second glycol subunits.

8. The multilayered optical film of claim 6, wherein the first monomer subunits are first carboxylate subunits and the second monomer subunits are second carboxylate subunits.

9. The multilayered optical film of claim 8, wherein the first polymer further comprises first glycol subunits and the second polymer further comprises second glycol subunits different from the first glycol subunits and wherein the polymer material of the one or more non-optical layers comprises the first and second glycol subunits in the same relative molar proportions as the molar proportions of the first and second glycol subunits in a combination of all the first and second optical layers of the multilayered polymer film.

10. The multilayered optical film of claim 8, wherein the first carboxylate subunits are naphthalate or terephthalate subunits.

11. The multilayered optical film of claim 10, wherein the second carboxylate subunits are derived from 2,6-naphthalene dicarboxylic acid or isomers thereof;

terephthalic acid;

isophthalic acid;

phthalic acid;

azelaic acid;

adipic acid;

sebacic acid;

norbomene dicarboxylic acid;

bi-cyclooctane dicarboxylic acid;

1,4-dicyclohexane dicarboxylic acid or isomers thereof;

t-butyl isophthalic acid;

tri-mellitic acid;

sodium sulfonated isophthalic acid;

2,2′

-biphenyl dicarboxylic acid or isomers thereof;

or C1-C10 alkyl esters of these acids.

12. The multilayered optical film of claim 8, wherein the second polyester further comprises third carboxylate subunits.

13. The multilayered optical film of claim 12, wherein the first and third carboxylate subunits are the same.

14. The multilayered optical film of claim 12, wherein the first polyester further comprises fourth carboxylate subunits.

15. A multilayered polymer film comprising:

a stack of layers using one or more first optical layers, one or more second optical layers, and one or more non-optical layers, the one or more first optical layers comprising a first polymer, the one or more second optical layers comprising a second polymer, and the one or more non-optical layers comprising a third polymer, wherein the third polymer consists essentially of monomer subunits, based on total monomer subunits, in the same relative molar proportions as the molar proportions of all of the monomer subunits in a combination of all the first and second optical layers of the multilayered polymer film.

16. The multilayered optical film of claim 15, wherein the first optical layers are birefringent.

17. The multilayered optical film of claim 15, wherein the first polymer is a polyester.

18. The multilayered optical film of claim 17, wherein the second polymer is a polyester.

19. A multilayered polymer film comprising:

a stack of layers comprising

one or more first optical layers comprising a first polyester, wherein the first polyester comprises first carboxylate subunits;

one or more second optical layers comprising a second polyester, wherein the second polyester comprises second carboxylate subunits, the first and second carboxylate subunits being different; and

one or more non-optical layers comprising a third polyester, wherein the third polyester comprises the first and second carboxylate subunits in the same relative molar proportions, based on total carboxylate subunits, as the molar proportions of the first and second carboxylate subunits in a combination of all the first and second optical layers of the multilayered polymer film.

20. The multilayered polymer film of claim 19, wherein the one or more first optical layers are birefringent.

21. The multilayered polymer film of claim 19, wherein the one or more first carboxylate subunits are naphthalate or terephthalate subunits.

22. The multilayered polymer film of claim 19, wherein the second carboxylate subunits are derived from 2,6-naphthalene dicarboxylic acid or isomers thereof;

terephthalic acid;

isophthalic acid;

phthalic acid;

azelaic acid;

adipic acid;

sebacic acid;

norbornene dicarboxylic acid;

bi-cyclooctane dicarboxylic acid;

1,4-dicyclohexane dicarboxylic acid or isomers thereof, t-butyl isophthalic acid;

tri-mellitic acid;

sodium sulfonated isophthalic acid;

2,2′

-biphenyl dicarboxylic acid or isomers thereof, or C1-C10 alkyl esters of these acids.

23. The multilayered polymer film of claim 19, wherein the non-optical layers further comprise a process aid material compatible with the first and second polyesters.

24. The multilayered polymer film of claim 19, wherein the first polyester further comprises first glycol subunits, the second polyester further comprises second glycol subunits, the first and second glycol subunits being different, and the third polyester comprises the first and second glycol subunits in the same relative molar proportions as the molar proportions of the first and second glycol subunits in a combination of all the first and second layers of the multilayered polymer film.

25. The multilayered polymer film of claim 19, wherein at least one of the one or more non-optical layers forms a skin layer on at least one surface of the stack of layers.

26. The multilayered polymer film of claim 19, wherein the first polyester is polyethylene naphthalate.

27. The multilayered polymer film of claim 19, wherein the first polyester is polyethylene terephthalate.

28. The multilayered polymer film of claim 19, wherein the first and second optical layers are formed in alternating pairs of layers.

29. The multilayered polymer film of claim 28, wherein at least one of the one or more non-optical layers is disposed between two of the alternating pairs of first and second optical layers.

30. A multilayered polymer film comprising:

a stack of layers comprising

one or more first optical layers comprising a first polyester, wherein the first polyester comprises first glycol subunits;

one or more second optical layers comprising a second polyester, wherein the second polyester comprises second glycol subunits, the first and second glycol subunits being different; and

one or more non-optical layers comprising a third polyester, wherein the third polyester comprises the first and second glycol subunits in the same relative molar proportions, based on total glycol subunits, as the molar proportions of the first and second glycol subunits in a combination of all the first and second optical layers of the multilayered polymer film.

31. The multilayered polymer film of claim 30, wherein the first glycol subunits are ethylene or butylene.

32. A multilayered optical film, comprising:

a stack of layers comprising

one or more first optical layers comprising a birefringent first polyester;

one or more second optical layers comprising a second polyester, and

one or more non-optical layers comprising polyester material that is recycled from one or more prior-manufactured multilayered polymer films,

wherein the first polyester comprises first carboxylate subunits and the second polyester comprises second carboxylate subunits, and the polyester material of the one or more non-optical layers comprises the first and second carboxylate subunits in the same relative molar proportions, based on total carboxylate subunits, as the molar proportions of the first and second carboxylate subunits in a combination of all the first and second optical layers of the multilayered optical film.

33. The multilayered optical film of claim 32, wherein the one or more non-optical layers further comprises non-recycled polyester material.