Polyester resin blends with high-level gas barrier properties

• US RE42,925 E1
• Filed: 11/17/2008
• Issued: 11/15/2011
• Est. Priority Date: 06/11/1998
• Status: Expired due to Term

• Current Assignee: APG Polytech LLC
• Original Assignee: Cobarr SPA
• Inventors: Al Ghatta, Hussein, Cobror, Sandro, Severini, Tonino
• Primary Examiner(s): AUGHENBAUGH, WALTER
• Application Number:
  US12/313,141
• Time in Patent Office: 1,093 Days
• Field of Search: 428/34.1, 428/34.6, 428/34.7, 428/35.2, 428/35.4, 428/35.5, 428/35.7, 428/36.6, 428/36.7, 428/36.9, 428/36.91, 428/36.92, 528/302, 528/308, 528/308.6, 525/425, 525/437, 525/540
• US Class Current: 428/35.7
• CPC Class Codes: B29B 2911/1402 at neck portion
• CPC Class Codes: B29B 2911/14026 at flange portion
• CPC Class Codes: B29B 2911/14033 at body portion
• CPC Class Codes: B29B 2911/1404 at bottom portion
• CPC Class Codes: B29B 2911/14106 having at least one layer
• CPC Class Codes: B29B 2911/14133 having at least one layer being injected
• CPC Class Codes: B29B 2911/1498 Weight
• CPC Class Codes: B29C 49/0042 without using a mould B29C49/1602 takes precedence
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: C08G 63/80 Solid-state polycondensation
• CPC Class Codes: C08G 63/916 Dicarboxylic acids and dihydroxy compounds
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 2377/06 Polyamides derived from polyamines and polycarboxylic acids C08J2377/10 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08K 2201/008 Additives improving gas barrier properties
• CPC Class Codes: C08K 5/092 Polycarboxylic acids
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 77/06 Polyamides derived from polyamines and polycarboxylic acids C08L77/10 takes precedence
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1379 : Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/139 : Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

Compositions comprising a polyester resin and a polyamide derived from a dicarboxylic acid with 6-22 carbon atoms and from m-xylylene diamine having high-level gas barrier properties, obtained by mixing in the melted state the polyester resin premixed with a dianhydride of a tetracarboxylic acid and the polyamide, operating under conditions such as to render the polymeric components theologically rheologically compatible with each other. The compositions are suitable for preparing containers and biaxially-orientated films.

Claims

1. A biaxially-oriented article selected from the group consisting of biaxially-oriented films and containers formed by using a material obtained by mixing a melted substance comprising:

a) an aromatic polyester, premixed with a dianhydride of a tetracarboxylic acid in an amount from 0.01 to 3% by weight;

b) a polyamide derived from m-xylylene diamine and from a dicarboxylic acid with 6-22 carbon atoms in an amount from 2 to 50% by weight on the sum of a)+b), wherein the polyamide is dispensed in the polyester in domains with an average size lower than 1 micron.

2. Containers according to claim 1, in the form of bottles for carbonated beverages.

3. Containers according to claim 1, obtained by injection blow-molding.

4. Containers according to claim 1, wherein the aromatic polyester is copolyethylene terephthalate containing up to 25% by weight units or sequences derived from isophthalic acid.

5. Article according to claim 1, wherein the polyamide is poly m-xylylene adipamide.

6. Article according to claim 1, wherein the dianhydride of the tetracarboxylic acid is pyromellitic dianhydride.

7. Article according to claim 1, wherein the starting polyester of the material used to prepare the container has an intrinsic viscosity from 0.3 to 0.8 dl/g.

8. Article according to claim 1, wherein the material obtained from the melted mixture comprising the polyester, the polyamide and the dianhydride is subjected to solid-state polycondensation for a time and temperature conditions sufficient to increase the intrinsic viscosity of the polyester by at least 0.1 units.

9. Article according to claim 1, wherein the polyester premixed with the dianhydride is subjected to a solid-state polycondensation treatment thereby the intrinsic viscosity of the initial polyester is increased by 0.1 units.

10. Article according to claim 1, wherein the melt viscosities of the polyester and the polyamide, determined at the mixing temperature, are in a ratio from 0.2:

1 to 4;

1.

11. Article according to claim 1, wherein the mixing of the components is performed in the extruder.

13. Films according to claim 5, obtained by biaxial stretching of films prepared by cast-extrusion.

14. Films according to claim 1, obtained by blow-molding using the double-bubble method.

12. Article made of or comprising a material obtained from compositions comprising a polyester resin and a polyamide wherein they have an oxygen permeability of less than 0.065 ml/bottle/day/atm, measured on a 1.5-liter bottle with a thickness of 225 microns obtained by injection blow molding.

25. Films according to claim 12 obtained by biaxial stretching of films prepared by cast-extrusion.

15. A polymeric material usable for preparing articles selected from the groups consisting of biaxially-oriented films and containers having high characteristics of resistance to gas CO₂ permeability of less than 7.25 ml/bottle/d/atm, as measured on a 1.5 liter bottle having an average thickness of 225 microns, obtained by mixing a melted material, comprising:

a) an aromatic polyester resin, premixed with a dianhydride of a tetracarboxylic acid, in an amount between 0.01 and 3% by weight;

b) a polyamide derived from m-xylylene diamine and from a dicarboxylic acid with 6-22 carbon atoms wherein the polyamide is dispensed in the polyester in domains with an average size lower than 1 micron.

16. A material according to claim 15, wherein the polyester resin is copolyethylene terephthalate containing up to 25% by weight of units derived from isophthalic acid.

17. A material according to claim 15, wherein the polyamide is poly m-xylylene adipamide.

18. A polymeric material according to claim 15, wherein the dianhydride is pyromellitic dianhydride.

19. A polymeric material according to claim 15, wherein the material obtained from the melted mixture comprising the components a), b) and c) is subjected to solid-state polycondensation until the intrinsic viscosity of the starting polyester is increased of at least 0.1 units.

20. A polymeric material according to claim 19, wherein the polyester premixed with the dianhydride is subjected to solid-state polycondensation until the intrinsic viscosity of the initial polyester is increased of at least 0.1 units.

21. A polymeric material according to claim 15, wherein the polyester and the polyamide have melt viscosities, at the mixing temperature, in a ratio from 0.2:

1 to 4;

1.

22. Containers whose resistance to oxygen permeability is less than 0.065 ml/bottle/day/atm, measured on a 1.5-liter bottle with a thickness of 225 microns prepared by injection-blow molding obtained from the polymeric material of claim 15.

23. A polymeric material comprising an aromatic polyester resin and a, poly-m-xylylene adipamide wherein the poly-m-xylylene adipamide is dispersed in a polyester resin matrix in domains with average size from 0.2 to 0.4 micron.

24. A polymeric material according to claim 23 wherein the polyester resin is a copolyethylene terephthalate containing up to 25% by weight of units derived from isophthalic acid and the polyamide is poly-m-xylylene adipamide.

26. A polymeric material according to claim 23 wherein the polyester resin is a copolyethylene terephthalate containing 1% to 15% by weight units derived from isophthalic acid and wherein the polyamide is poly-m-xylylene adipamide.

27. A polymeric material according to claim 23 which is further comprised of pyromellitic dianhydride.

28. A polymeric material according to claim 26 which is further comprised of pyromellitic dianhydride.

29. A polymeric material according to claim 23 wherein the polymeric material is in the form of a preform.

30. A polymeric material according to claim 24 wherein the polymeric material is in the form of a preform.

31. A polymeric material according to claim 26 wherein the polymeric material is in the form of a preform.

32. A container which is made from the polymeric material specified in claim 23.

33. A container which is made from the polymeric material specified in claim 24.

34. A container which is made from the polymeric material specified in claim 26.

35. A container which is made from the preform specified in claim 29.

36. A container which is made from the preform specified in claim 30.

37. A container which is made from the preform specified in claim 31.

38. A container as specified in claim 32 wherein the container is made by injection-blow molding.

39. A container as specified in claim 33 wherein the container is made by injection-blow molding.

40. A container as specified in claim 34 wherein the container is made by injection-blow molding.

41. A bottle which is made from the polymeric material specified in claim 23.

42. A bottle which is made from the polymeric material specified in claim 24.

43. A bottle which is made from the polymeric material specified in claim 26.

44. A bottle made from the preform specified in claim 29.

45. A bottle made from the preform specified in claim 30.

46. A bottle made from the preform specified in claim 31.

47. A bottle as specified in claim 41 wherein the bottle is made by injection-blow molding.

48. A bottle as specified in claim 42 wherein the bottle is made by injection-blow molding.

49. A bottle as specified in claim 43 wherein the bottle is made by injection-blow molding.

50. A bottle as specified in claim 44 wherein the bottle is made by injection-blow molding.

51. A bottle as specified in claim 45 wherein the bottle is made by injection-blow molding.

52. A bottle as specified in claim 46 wherein the bottle is made by injection-blow molding.

53. A bottle as specified in claim 47 wherein said bottle has a CO₂ permeability of less than 7.25 ml/bottle/d/atm, as measured on a 1.5 liter bottle having an average thickness of 225 microns.

54. A bottle as specified in claim 52 wherein said bottle has a CO₂ permeability of less than 7.25 ml/bottle/d/atm, as measured on a 1.5 liter bottle having an average thickness of 225 microns.