Coextruded multi-layered articles

• US 4,540,623 A
• Filed: 01/29/1985
• Issued: 09/10/1985
• Est. Priority Date: 10/14/1983
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Shrum, William E., Im, Jang-hi
• Primary Examiner(s): Herbert, Thomas J.
• Application Number:
  US06/696,231
• Time in Patent Office: 224 Days
• Field of Search: 428/412, 428/36, 428/213, 428/220, 264/46.1, 264/171, 425/133.5
• US Class Current: 428/220
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/31507 Of polycarbonate

Abstract

Laminated articles in the form of an extruded sheet have a multi-layered structure and comprise, on the average, alternating layers of coextruded polymeric thermoplastic materials, wherein one of said materials comprises a carbonate polymer. The articles exhibit good impact resistance even when scratched or notched, hydrolytic stability and transparency.

Claims

1. An impact resistant laminated article in the form of an extruded sheet having a thickness of greater than 10 mils and having a multi-layered structure comprising, on the average, alternating layers of coextruded polymeric, thermoplastic materials wherein the number of layers is greater than or equal to about 40, and wherein one of said materials forming said alternating layers contains a carbonate polymer;

and the alternating layers containing carbonate polymer are bound in an essentially contiguous relationship to adjacent layers of the other polymeric materials comprising said article, wherein said alternating layers are in the form of thin films each having a relatively sharply defined interface and are generally parallel to the major surface of said article;

said article being comprised of from about 35 to about 90 percent by volume of said layers containing carbonate polymer.

2. A laminated article of claim 1 wherein the thickness of said sheet is from greater than 0.25 mm to about 2.5 cm.

3. A laminated article of claim 1 wherein the number of said alternating layers ranges from about 40 to about 1500.

4. A laminated article of claim 1 wherein said article is transparent.

5. A laminated article of claim 1 wherein the thickness of said sheet is from about 0.76 mm to about 1.3 cm.

6. A laminated article of claim 1 wherein said article has applied to the major surfaces thereof, a polyolefinic sacrificial skin.

7. A laminated article of claim 1 wherein the outermost layers of said multi-layered structure comprise a carbonate polymer.

8. A laminated article of claim 1 wherein said carbonate polymer is a homopolymer of bisphenol-A.

9. A laminated article of claim 1 wherein said layers containing carbonate polymer comprise a major amount of a carbonate polymer and a minor amount of at least one of another thermoplastic material.

10. A laminate article of claim 1 where additives selected from the group consisting of stabilizers, lubricants, plasticizers, anti-oxidants, fire retardants, fillers, reinforcing fibers and pigments are incorporated into said article through said thermoplastic materials.

11. A laminated article of claim 1 wherein said layers containing a carbonate polymer consist essentially of carbonate polymer.

12. A laminated article of claim 1 wherein said article is comprised of from about 40 to about 80 percent by volume of layers containing carbonate polymer.

13. A laminated article of claim 1 having a thickness of greater than 10 mils and having a suitable thickness for application in glazing applications.

14. A laminated article of claim 1 wherein the multi-layered structure comprises, on the average, alternating layers of two coextruded polymeric, thermoplastic materials wherein one of said polymeric materials is a carbonate polymer.

15. A laminated article of claim 14 wherein one of said polymeric, thermoplastic materials is a styrene/acrylonitrile copolymer.

16. A laminated article of claim 14 wherein one of said polymeric, thermoplastic materials is a styrene/acrylic acid copolymer.

17. A laminated article of claim 14 wherein one of said polymeric, thermoplastic materials is polymethylmethacrylate.

18. A laminated article of claim 14 wherein one of said polymeric, thermoplastic materials is a rubber-modified styrene/acrylonitrile copolymer.

19. A laminated article of claim 1 wherein said article has applied therein and to the major surfaces thereof, an integral skin.

20. A laminated article of claim 19 wherein an ultra-violet stabilizer is incorporated into said integral skin.

21. A laminated article of claim 1 wherein said layers containing carbonate polymer comprise a major amount of a carbonate polymer and a minor amount of at least one other polymeric thermoplastic material.

22. A laminated article of claim 21 wherein said other thermoplastic material is a copolymer of styrene/acrylonitrile or styrene/acrylic acid.

23. A laminated article of claim 21 wherein the refractive indices of said polymeric, thermoplastic materials are essentially equal to that of said carbonate polymer.

24. A laminated article of claim 21 wherein said article is transparent.