Plastic adhesive labels for glass substrates

• US 5,712,031 A
• Filed: 03/06/1996
• Issued: 01/27/1998
• Est. Priority Date: 03/06/1996
• Status: Expired due to Fees

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Kelch, Robert H., Tung, Harvey C.
• Primary Examiner(s): KRYNSKI, WILLIAM A
• Application Number:
  US08/610,560
• Time in Patent Office: 692 Days
• Field of Search: 428/500, 428/411.1, 428/195, 428/355 R, 428/913, 428/914, 428/355, 428/337, 428/343, 428/522
• US Class Current: 428/355.0BL
• CPC Class Codes: B32B 2323/10 Polypropylene
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2519/00 Labels, badges
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/32 comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C09J 2301/162 the carrier being a laminate constituted by plastic layers only
• CPC Class Codes: C09J 7/29 Laminated material metallised plastics C09J7/22
• CPC Class Codes: G09F 3/10 by an adhesive layer
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/266 of base or substrate
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2883 including addition polymer of diene monomer [e.g., SBR, SIS, etc.]
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

A multilayer film useful for making plastic adhesive labels for glass substrates such as glass bottles. The multilayer films contain a base layer, an adhesive layer, and optionally an intermediate layer to improve interlayer bonding between the base layer and the adhesive layer. The adhesive layer comprises a terpolymer of ethylene, 3-10 weight percent of an ethylenically unsaturated carboxylic acid (e.g. acrylic acid or methyacrylic acid), and 3-25 weight percent of an unsaturated ester (e.g., methyl, ethyl, or n-butyl acrylate or methacrylate). The base layer preferably comprises oriented polypropylene or oriented polyester, but may also comprise high density polyethylene or PETG. The multilayer film can be utilized in conventional graphics printing operations and do not require the use of a separate release liner. Labels made from films of the present invention exhibit sufficient adhesion to glass substrates to withstand washing/rinsing, filling, and pasteurization processes utilized in the bottling industry.

Claims

1. A multilayer film, comprising:

i) an ink-printable base layer having a 1% secant modulus of at least 200,000 psi as measured by ASTM D-882, said base layer having a water vapor transmission rate of less than about 3.0 g-mil/100 in² -24 hr as measured by ASTM F-1249;

ii) an optional intermediate layer for improving interlayer bonding between said base layer and said adhesive layer;

said intermediate layer, when present, is bonded directly to said base layer; and

iii) an adhesive layer, said adhesive layer consisting essentially of a terpolymer of ethylene, 3-10 weight percent of an ethylenically unsaturated carboxylic acid, and 3-25 weight percent of an unsaturated ester, said adhesive layer bonded directly to said intermediate layer when said intermediate layer is present, said adhesive layer bonded directly to said base layer when said intermediate layer is not present, said adhesive layer being sufficiently nontacky at room temperature such that the multilayer film does not exhibit significant blocking at room temperature,

wherein the multilayer film, upon contacting said adhesive layer to a glass substrate heated to at least about 200°

F. and thereafter cooling, exhibits a dry adhesion peel strength of at least about 750 grams/inch and a wet adhesion peel strength of at least about 450 grams/inch.

2. A multilayer film according to claim 1, wherein the thickness of said base layer is between about 0.4 mils and 3.0 mils.

3. A multilayer film according to claim 1, wherein the thickness of said adhesive layer is between about 0.3 mils and 1.5 mils.

4. A multilayer film according to claim 1, wherein said adhesive layer consists essentially of an adhesive having a melting point between 150°

F. (65°

C.) and 200°

F. (93°

C.).

5. A multilayer film according to claim 1, wherein said adhesive layer consists essentially of an adhesive having a melt index of at least 2 grams/10 minutes at 190°

C.

6. A multilayer film according to claim 1, wherein said adhesive layer consists essentially of an adhesive having a 125°

C. melt flow rate of at least 0.2 grams/10 minutes.

7. A multilayer film according to claim 1, wherein said adhesive layer consists essentially of a terpolymer of ethylene, 4-8 weight percent acrylic acid, and 15-20 weight percent methyl acrylate.

8. A multilayer film according to claim 1, wherein said base layer consists essentially of oriented polypropylene, oriented polyester, high density polyethylene, or glycol-modified copolyester.

9. A multilayer film according to claim 1, wherein said base layer consists essentially of oriented polypropylene or oriented polyester.

10. A multilayer film according to claim 1, wherein said base layer has a 45°

gloss of at least 80%.

11. A multilayer film according to claim 1, wherein said base layer has a maximum haze of 9%.

12. A multilayer film according to claim 1, wherein said base layer has a water vapor transmission rate of less than about 1.5 g-mil/100 in² -24 hr as measured by ASTM F-1249.

13. A multilayer film according to claim 1, wherein said intermediate layer consists essentially of a copolymer of ethylene and vinyl acetate.

14. A multilayer film according to claim 1, wherein the film exhibits a dry adhesion peel strength of at least about 900 grams/inch.