Tear resistant multilayer films and articles incorporating such films

• US 5,427,842 A
• Filed: 05/27/1994
• Issued: 06/27/1995
• Est. Priority Date: 10/01/1992
• Status: Expired due to Term

• Current Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Original Assignee: Minnesota Mining and Manufacturing Co (3M Company)
• Inventors: Jonza, James M., Stambaugh, Bruce D., Smith, James D., Allen, Richard C., Smith, Kenneth B., Bradley, Jeffrey F., Bland, Ralph H.
• Primary Examiner(s): Zirker, Daniel R.
• Application Number:
  US08/250,645
• Time in Patent Office: 396 Days
• Field of Search: 428/354, 428/40, 428/480, 428/483, 428/515, 428/213, 428/216, 428/215, 428/910
• US Class Current: 428/213
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 2307/5825 Tear resistant
• CPC Class Codes: B32B 2309/105 Thickness
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/022 Mechanical properties
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10S 428/911 Penetration resistant layer
• CPC Class Codes: Y10T 428/1443 Aluminum
• CPC Class Codes: Y10T 428/1448 Coloring agent containing
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24967 Absolute thicknesses specified
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/2848 Three or more layers
• CPC Class Codes: Y10T 428/31554 Next to second layer of polyamidoester
• CPC Class Codes: Y10T 428/31562 Next to polyamide [nylon, etc.]
• CPC Class Codes: Y10T 428/31565 Next to polyester [polyethylene terephthalate, etc.]
• CPC Class Codes: Y10T 428/31573 : Next to addition polymer of ethylenically unsaturated monomer
• CPC Class Codes: Y10T 428/31616 : Next to polyester [e.g., alkyd]
• CPC Class Codes: Y10T 428/31623 : Next to polyamide or polyimide
• CPC Class Codes: Y10T 428/31645 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31728 : Next to second layer of polyamide
• CPC Class Codes: Y10T 428/31732 : At least one layer is nylon type
• CPC Class Codes: Y10T 428/31736 : Next to polyester
• CPC Class Codes: Y10T 428/31743 : Next to addition polymer from unsaturated monomer[s]
• CPC Class Codes: Y10T 428/31757 : Polymer of monoethylenically unsaturated hydrocarbon
• 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 428/31909 : Next to second addition polymer from unsaturated monomers

Abstract

A tear resistant film comprises more than five layers situated one on the other in a parallel array. The layers are individually selected from a stiff polyester or copolyester, a ductile polymeric material, and optionally, an intermediate material. The stiff polyester or copolyester is oriented in at least one direction. Tear resistance may be measured in a Graves area test and reflects the ability of the film to absorb energy. The films of the invention are useful in many articles including security control laminates for glazing members.

Claims

1. A security control laminate comprising a first tear resistant film having a first face and a second face opposite the first face and a first layer of adhesive on the first face of the tear resistant film for bonding the security control laminate to a surface, the first tear resistant film comprising a total of more than five stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array, wherein (a) at least two of the layers are a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi, the layers of stiff polyester or copolyester having an average nominal thickness greater than about 1 μ

m, and (b) at least two other layers are a ductile polymeric material that has been oriented in at least one direction, has a tensile modulus less than 200 kpsi, and has a tensile elongation greater than 50%.

2. A security control laminate according to claim 1 further comprising means for absorbing ultraviolet radiation, the means being either on or incorporated into a layer of the security control laminate.

3. A security control laminate according to claim 2 wherein the means for absorbing ultraviolet radiation is a coating layer interposed between the first tear resistant film and the first layer of adhesive.

4. A security control laminate according to claim 1 further comprising a dyed film, a surface of which is adhesively bonded to the second face of the first tear resistant film.

5. A security control laminate according to claim 4 further comprising an abrasion resistant coating on a surface of the dyed film opposite the surface which is adhesively bonded to the tear resistant film.

6. A security control laminate according to claim 1 further comprising a second tear resistant film, one face of which is adhesively bonded to the second face of the first tear resistant film, the second tear resistant film comprising a total of more than five stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array, wherein (a) at least two of the layers are a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi and (b) at least two other layers are a ductile polymeric material that has been oriented in at least one direction, has a tensile modulus less than 200 kpsi, and has a tensile elongation greater than 50%.

7. A security control laminate according to claim 6 further comprising a metallized layer on either the first or the second tear resistant film.

8. A security control laminate according to claim 7 wherein the metallized layer is secured to a face of the second tear resistant film opposite the face which is bonded to the first tear resistant film.

9. A security control laminate according to claim 7 wherein the metallized layer comprises an optically clear film having a layer of metal selected from the group consisting of aluminum, gold, silver, nickel and copper thereon.

10. A security control laminate according to claim 7 further comprising an abrasion resistant coating over the metallized layer.

11. A security control laminate according to claim 1 wherein the layers of stiff polyester or copolyester and the layers of ductile polymeric material have been biaxially oriented.

12. A security control laminate according to claim 1 wherein the first tear resistant film has a Graves area in one direction of the film equal to at least 40+0.4(x) kpsi %, wherein x is the nominal thickness of the first tear resistant film in microns.

13. A security control laminate according to claim 12 wherein the first tear resistant film has a tensile modulus of at least 175 kpsi in one direction of the film.

14. A security control laminate according to claim 13 wherein the first tear resistant film has a tensile modulus of at least 450 kpsi in one direction of the film.

15. A security control laminate according to claim 12 wherein the first tear resistant film has a Graves elongation at break of at least 20% in the tear direction of the film measured during the determination of Graves area.

16. A security control laminate according to claim 15 wherein the first tear resistant film has a Graves elongation at break of at least 40% in the tear direction of the film measured during the determination of Graves area.

17. A security control laminate according to claim 1 wherein the stiff polyester or copolyester comprises the reaction production of (a) a dicarboxylic acid component selected from the group consisting of terephthalic acid, naphthalene dicarboxylic acid and ester derivatives thereof, and (b) a diol component selected from the group consisting of ethylene glycol and 1,4-butanediol.

18. A security control laminate according to claim 1 wherein the ductile polymeric material is selected from the group consisting of ethylene copolymers, polyesters, copolyesters, polyolefins, polyamides, and polyurethanes.

19. A security control laminate according to claim 18 wherein the ductile polymeric material is a copolyester comprising the reaction product of cyclohexane dicarboxylic acid (or ester derivatives thereof), cyclohexane dimethanol and polytetramethylene glycol.

20. A security control laminate according to claim 1 wherein the ductile polymeric material provides at most about 20 weight percent of the first tear resistant film.

21. A security control laminate according to claim 1 further comprising a layer of an intermediate material disposed between otherwise adjacent layers of stiff polyester or copolyester and ductile polymeric material wherein the layer of intermediate material enhances the adhesion between the otherwise adjacent layers of stiff polyester or copolyester and ductile polymeric material.

22. A security control laminate comprising a first tear resistant film having a first face and a second face opposite the first face and a first layer of adhesive on the first face of the tear resistant film for bonding the security control laminate to a surface, the first tear resistant film comprising a total of more than five stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array, wherein (a) at least two of the layers are a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi, the layers of stiff polyester or copolyester having an average nominal thickness of about 1 to 15 μ

m, and (b) at least two other layers are a ductile polymeric material that has a tensile modulus less than 200 kpsi and a tensile elongation greater than 50%, wherein the ductile polymeric material is selected from the group consisting of ethylene copolymers, polyesters, copolyesters, polyolefins, and polyamides.

23. A security control laminate according to claim 22 further comprising means for absorbing ultraviolet radiation, the means being either on or incorporated into a layer of the security control laminate.

24. A security control laminate according to claim 22 further comprising a dyed film, a surface of which is adhesively bonded to the second face of the first tear resistant film.

25. A security control laminate according to claim 24 further comprising an abrasion resistant coating on a surface of the dyed film opposite the surface which is adhesively bonded to the first tear resistant film.

26. A security control laminate according to claim 22 further comprising a second tear resistant film one face of which is adhesively bonded to the second face of the first tear resistant film, the second tear resistant film comprising a total of more than five stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array, wherein (a) at least two of the layers are a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi and (b) at least two other layers are a ductile polymeric material that has a tensile modulus less than 200 kpsi and a tensile elongation greater than 50%.

27. A security control laminate according to claim 26 further comprising a metallized layer on the face of the second tear resistant film opposite the face which is bonded to the first tear resistant film.

28. A security control laminate according to claim 27 further comprising an abrasion resistant coating over the metallized layer.

29. A security control laminate according to claim 22 wherein the first tear resistant film has a Graves area in one direction of the film equal to at least about 40+0.4(x) kpsi %, wherein x is the nominal thickness of the first tear resistant film in microns.

30. A security control laminate according to claim 29 wherein the first tear resistant film has a tensile modulus of at least 175 kpsi in one direction of the film.

31. A security control laminate according to claim 30 wherein the first tear resistant film has a tensile modulus of at least 450 kpsi in one-direction of the film.

32. A security control laminate according to claim 29 wherein the first tear resistant film has a Graves elongation at break of at least 20% in the tear direction of the film measured during the determination of Graves area.

33. A security control laminate according to claim 32 wherein the first tear resistant film has a Graves elongation at break of at least 40% in the tear direction of the film measured during the determination of Graves area.

34. A security control laminate comprising a tear resistant film having a first face and a second face opposite the first face and a first layer of adhesive on the first face of the tear resistant film for bonding the security control laminate to a surface, the tear resistant film comprising a total of more than five stiff and ductile layers situated one on the other in a parallel array, the layers occurring essentially randomly in the array, wherein (a) at least two of the layers are a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi, the layers of stiff polyester or copolyester having an average nominal thickness of about 1 to 15 μ

m, and (b) at least two other layers are a ductile polymeric material that has a tensile modulus less than 200 kpsi and a tensile elongation greater than 50%, the layers of ductile polymeric material having an average nominal thickness of less than 3 μ

m.

35. A security control laminate according to claim 34 wherein the tear resistant film has a Graves area in one direction of the film equal to at least about 40+0.4(x) kpsi %, wherein x is the nominal thickness of the first tear resistant film in microns.

36. A security control laminate according to claim 35 wherein the tear resistant film has a tensile modulus of at least 175 kpsi in one direction of the film.

37. A security control laminate according to claim 36 wherein the tear resistant film has a tensile modulus of at least 450 kpsi in one direction of the film.

38. A security control laminate according to claim 34 wherein the tear resistant film has a Graves elongation at break of at least 20% in the tear direction of the film measured during the determination of Graves area.

39. A security control laminate according to claim 38 wherein the tear resistant film has a Graves elongation at break of at least 40% in the tear direction of the film measured during the determination of Graves area.

40. A security control laminate according to claim 34 further comprising means for absorbing ultraviolet radiation, the means being either on or incorporated into a layer of the security control laminate.

41. A security control laminate according to claim 40 further comprising a dyed film, a surface of which is adhesively bonded to the second face of the tear resistant film.

42. A security control laminate according to claim 41 further comprising an abrasion resistant coating on a surface of the dyed film opposite the surface which is adhesively bonded to the tear resistant film.

43. A security control laminate comprising:

(A) a tear resistant film having a first face and a second face opposite the first face;

(B) a first layer of adhesive on the first face of the tear resistant film for bonding the security control laminate to a surface; and

(C) means for absorbing ultraviolet radiation, the means being either on or incorporated into a layer of the security control laminate;

wherein the tear resistant film comprises a total of about thirteen alternating stiff and ductile layers situated one on the other in a parallel array, and further wherein;

(a) about seven of the layers are a stiff polyester or copolyester that has a tensile modulus greater than 200 kpsi and that comprises the reaction product of (i) a dicarboxylic acid component selected from the group consisting of terephthalic acid, naphthalene dicarboxylic acid, and ester derivatives thereof, and (ii) a diol component selected from the group consisting of ethylene glycol and 1,4-butanediol, the layers of stiff polyester or copolyester having an average nominal thickness greater than about 1 μ

m;

(b) about six other layers are a ductile polymeric material that has a tensile modulus less than 200 kpsi and a tensile elongation greater than 50%;

(c) the tear resistant film has a Graves area in one direction of the film equal to at least about 40+0.4(x) kpsi %, wherein x is the nominal thickness of the tear resistant film in microns;

(d) the tear resistant film has a Graves elongation at break of at least 20% in the tear direction of the film measured during the determination of Graves area; and

(e) the tear resistant film has a tensile modulus of at least 175 kpsi in one direction of the film.