Film composition

• US 5,491,023 A
• Filed: 06/10/1994
• Issued: 02/13/1996
• Est. Priority Date: 06/10/1994
• Status: Expired due to Fees

• Current Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: Tsai, Mingliang L., Balloni, Riccardo
• Primary Examiner(s): Buffalow, Edith
• Application Number:
  US08/258,316
• Time in Patent Office: 613 Days
• Field of Search: 428/35.3, 428/349, 428/323, 428/463, 428/500
• US Class Current: 428/349
• CPC Class Codes: B32B 2250/246 All polymers belonging to those covered by groups B32B27/32 and B32B27/30
• CPC Class Codes: B32B 2307/31 Heat sealable
• CPC Class Codes: B32B 2323/10 Polypropylene
• CPC Class Codes: B32B 2329/04 Polyvinylalcohol
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/306 comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 37/153 at least one layer is extruded and immediately laminated while in semi-molten state
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/1338 Elemental metal containing
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/31699 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

A metallized multilayer film made from a polymer substrate, preferably polypropylene, is modified by a maleic anhydride modified propylene polymer which can be located on a surface of the substrate or incorporated within the substrate has a skin layer of polyvinyl alcohol which is capable of being metallized.

Claims

1. A metallized film composition comprising a polymer substrate having a surface which is modified by an adhesion promoting agent, the modified surface of the polymer substrate having a skin layer of 100% polyvinyl alcohol, the skin layer having a metal layer directly thereon.

2. The metallized film composition of claim 1 in which the adhesion promoting agent is a maleic anhydride modified propylene homopolymer or copolymer.

3. The metallized film composition of claim 1 in which the modified surface of the substrate is treated by either flame treatment or corona treatment.

4. The metallized film composition of claim 1 in which the polyvinyl alcohol skin layer is free of crosslinking agent.

5. The metallized film composition of claim 1 in which the polyvinyl alcohol skin layer is extrudable polyvinyl alcohol.

6. The metallized film composition of claim 5 in which the polyvinyl alcohol skin layer is a partially hydrolyzed grade.

7. The metallized film composition of claim 6 in which the polyvinyl alcohol skin layer is at least 70% hydrolyzed.

8. The metallized film composition of claim 1 in which there is a heat sealable layer on the substrate opposite the PVOH.

9. A process for making a metallized film composition comprising the steps of:

(a) providing a polymeric substrate film;

(b) modifying at least one surface of the polymeric substrate film with a maleic anhydride modified polypropylene homopolymer or copolymer;

(c) applying an oxygen barrier consisting essentially of polyvinyl alcohol to the modified surface of the substrate; and

(d) metallizing the polyvinyl alcohol surface formed in step (c).

10. The process of claim 9 in which the polymeric substrate is a homopolymer or copolymer of propylene.

11. The process of claim 9 which further comprises treating a surface of the polymeric film substrate opposite the polyvinyl alcohol with a heat sealable composition.

12. A metallized film composition made by the process of claim 9.

13. A metallized film composition made by the process of claim 10.

14. A metallized film composition made by the process of claim 13.

15. The process of claim 9 in which the film of step (b) is stretched in the machine direction 4 to 7 times and then flame treated.

16. The process of claim 9 in which the film of step (c) is stretched in the transverse direction 5 to 12 times and then flame treated.