Multilayer plastic film, process for its production and its use

• US 4,370,374 A
• Filed: 09/02/1980
• Issued: 01/25/1983
• Est. Priority Date: 09/04/1979
• Status: Expired due to Term

• Current Assignee: Plate BONN Gesellschaft Mit Beschrankter Haftung
• Original Assignee: Plate BONN Gesellschaft Mit Beschrankter Haftung
• Inventors: Schruhl, Robert, Raabe, Fritz
• Primary Examiner(s): Willis, Jr., P. E.
• Application Number:
  US06/183,042
• Time in Patent Office: 875 Days
• Field of Search: 428/212, 428/215, 428/216, 428/315, 428/423.3, 428/423.5, 428/423.7, 428/424.8, 428/474.7, 428/474.9, 428/475.2, 428/476.1, 428/476.9, 428/483, 156/213, 156/304.4, 156/309.9, 156/322, 156/324.4
• US Class Current: 428/216
• CPC Class Codes: B32B 2307/75 Printability
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 7/06 permitting easy separation
• CPC Class Codes: Y10T 156/103 Encasing or enveloping the configured lamina
• 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 428/249991 Synthetic resin or natural rubbers
• 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 428/31587 Hydrocarbon polymer [polyethylene, polybutadiene, etc.]
• CPC Class Codes: Y10T 428/31728 Next to second layer of polyamide
• CPC Class Codes: Y10T 428/31736 Next to polyester
• CPC Class Codes: Y10T 428/31746 Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 428/31757 Polymer of monoethylenically unsaturated hydrocarbon

Abstract

The invention provides a multilayer plastics film comprising at least two film layers, one of which has a thickness of 10 to 50 μm and a softening point of 140° to 200° C., and the other of which has a thickness of 10 to 50 μm, a softening point of 70° to 130° C. and initial melting point of from 100° to 190° C., there being a temperature difference of from 30° to 60° C. between the softening point and initial melting point of the latter film. The invention also provides processes for making such multilayer plastics films and their use for applying to articles, particularly foamed plastics, a firmly adhering skin.

Claims

1. Multilayer plastic film useful for encapsulating objects, which comprises

(a) a first individual film having a thickness of from 10 to 50 microns and a softening point of from 140°

to 250°

C., and

(b) a second film having a thickness of from 10 to 50 microns, a softening point of from 70°

to 130°

C. and an initial melting point of from 100°

to 190°

C., there being a temperature difference of from 10°

to 60°

C. between the softening point and the initial melting point of the second film.

2. Multilayer plastic film according to claim 1, characterized in that at least one of said individual films has a thickness of from 20 microns to 40 microns.

3. Multilayer plastic film according to claim 1, characterized in that the first film possesses a softening point between 160°

C. and 220°

C.

4. Multilayer plastic film according to claim 1, characterized in that the second film possesses a softening point of between 80°

C. and 120°

C. and an initial melting point of from 120°

C. to 160°

C.

5. Multilayer plastic film according to claim 4, characterized in that the second film possesses a softening point between 90°

C. and 110°

C. and an initial melting point of from 130°

C. to 150°

C.

6. Multilayer plastic film according to claim 1, characterized in that there is a temperature difference of from 30°

C. to 50°

C. between the softening point and the initial melting point of the second film.

7. Multilayer plastic film according to claim 1, characterized in that

(a) at least one further individual film is interposed between said first and second films,

(b) said further film having a softening point which respectively lies between those of said first and second films.

8. Multilayer plastic film according to claim 1, characterized in that

(a) at least one further individual film is interposed between said first and second films,

(b) said further film having an initial melting point higher than those of said first and second films.

9. Multilayer plastic film according to claim 1, characterized in that it is more than 80 cm wide and more than 1 m long.

10. Multilayer plastic film according to claim 1, characterized in that at least one of said individual films comprises polyurethane, polyamide or polyester.

11. Multilayer plastic film according to claim 1, characterized in that it possesses at least one side protective film capable of being stripped off.

12. Multilayer plastic film according to claim 11, characterized in that

(a) said protective film is made of polyethylene, and

(b) at least one of said other films comprises polyurethane or copolyamide.

13. Multilayer plastic film according to claim 1, characterized in that it is structured, printed or painted on.

14. Process for the production of a multilayer plastic film as defined in claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, comprising:

(a) joining together the individual film layers of said multilayer plastics film under the influence of heat and pressure.

15. Process for the production of a multilayer plastic film as defined in claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 comprising:

(a) coextruding said multiple layer film.

16. Use of a multilayer plastic film according to claims 1, 5, 7, 8 or 10 for applying to foamed plastic articles a firmly adhering skin.

17. Process for preparing an article having a firmly adhering skin using the multilayer plastic film of claim 1, 5, 7, 8 or 10 comprising:

(a) heating the multilayer plastic film to or a little above the softening point of the second film, and

(b) applying it to the article.