UV barrier film

• US 8,906,987 B2
• Filed: 01/20/2014
• Issued: 12/09/2014
• Est. Priority Date: 07/24/2007
• Status: Active Grant

• Current Assignee: Innovia Films Limited (Innovia Films)
• Original Assignee: Innovia Films Limited (Innovia Films)
• Inventors: Denecker, Celine
• Primary Examiner(s): CHIN, HUI H
• Application Number:
  US14/159,115
• Publication Number:
  US 20140155517A1
• Time in Patent Office: 323 Days
• Field of Search: 524/100
• US Class Current: 524/100
• CPC Class Codes: C08J 2323/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08K 2201/003 Additives being defined by their diameter
• CPC Class Codes: C08K 3/014 Stabilisers against oxidation, heat, light or ozone
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 5/005 Stabilisers against oxidation, heat, light, ozone
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

Transparent polypropylene film comprising at least two UV-absorbing additives, a first additive being a non-aggregated inorganic material present in the film composition in an amount of from 0.1 to 5.0% by weight, and a second additive comprising an organic material selected from triazines, hindered amines, oxanilides, cyanoacrylates, benzotriazoles and/or benzophenones and present in the film in an amount of less than 2.0% by weight and wherein when both benzotriazole(s) and benzophenone(s) are present in the film, the ratio of benzotriazole(s) to benzophenone(s) is above 0.5.

Claims

1. A transparent polypropylene film comprising:

at least a first and a second ultraviolet (UV)-absorbing additive;

wherein said first additive comprises a non-aggregated inorganic material present in a film composition in an amount of from 0.1% to 5.0% by weight, and

wherein said second additive comprises an organic material comprising benzotriazoles;

wherein benzophenone is absent in the film composition;

wherein said second additive is present in the film in an amount of less than 2.0% by weight,

wherein the average particle size of the inorganic additive is less than 100 nm.

2. A film according to claim 1 wherein the first additive comprises one or more compounds selected from the group consisting of:

mineral and metal oxides.

3. A film according to claim 2 wherein the first additive comprises one or more compounds selected from the group consisting of:

zinc and titanium oxides.

4. A film according to claim 1 formulated in the absence of any binder material for solubilising the second additive.

5. A film according to claim 1 wherein the first additive is present in an amount below 4.5% by weight of the film composition.

6. A film according to claim 1 wherein the first additive is present in an amount below 3.5% by weight of the film composition.

7. A film according to claim 1 wherein the second additive is present in an amount below 1.0% by weight of the film composition.

8. A film according to claim 1 wherein at the point of maximum transmittance of UV light between 220 and 350 nm the film transmits no more than 30% of the UV light incident upon the film at the wavelength of the said maximum transmittance.

9. A film according to claim 1 exhibiting wide angle haze (WAH) of less than 10%.

10. A film according to claim 1 exhibiting gloss at 45°

angle of greater than 80%.

11. A transparent polypropylene film comprising:

a first ultraviolet (UV)-absorbing additive comprising a non-aggregated inorganic material present in the film in an amount of from 0.1% to 5.0% by weight,

wherein the average particle size of the inorganic additive is less than 100 nm;

a second UV-absorbing additive comprising benzotriazoles,

wherein said second additive is present in the film in an amount of less than 2.0% by weight,

wherein benzophenone is absent in the film.

12. A film according to claim 11 wherein the first UV-absorbing additive comprises one or more compounds selected from the group consisting of:

mineral and metal oxides.

13. A film according to claim 12 wherein the first UV-absorbing additive comprises one or more compounds selected from the group consisting of:

zinc and titanium oxides.

14. A film according to claim 11 formulated in the absence of any binder material for solubilising the second UV-absorbing additive.

15. A film according to claim 11 wherein the first UV-absorbing additive is present in an amount below 4.5% by weight of the film.

16. A film according to claim 11 wherein the first UV-absorbing additive is present in an amount below 3.5% by weight of the film.

17. A film according to claim 11 wherein the second UV-absorbing additive is present in an amount below 1.0% by weight of the film.

18. A film according to claim 11 wherein at the point of maximum transmittance of UV light between 220 and 350 nm, the film transmits no more that than 30% of the UV light incident upon the film at the wavelength of the said maximum transmittance.

19. A film according to claim 11 exhibiting wide angle haze (WAH) of less than 10%.

20. A film according to claim 11 exhibiting gloss at 45°

angle of greater than 80%.