Multilayer Container And Method For Producing Regenerated Polyester

• US 20200131307A1
• Filed: 01/02/2020
• Published: 04/30/2020
• Est. Priority Date: 09/15/2016
• Status: Abandoned Application

• Current Assignee: Mitsubishi Gas Chemical Company Incorporated (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Gas Chemical Company Incorporated (Mitsubishi Electric Corporation)
• Inventors: Otsuka, Kosuke, Oda, Takafumi
• Application Number:
  US16/732,601
• Publication Number:
  US 20200131307A1
• Time in Patent Office: Days
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 2250/40 Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• CPC Class Codes: B32B 2272/00 Resin or rubber layer comprising scrap, waste or recycling material
• CPC Class Codes: B32B 2307/30 having particular thermal properties
• CPC Class Codes: B32B 2307/308 Heat stability dimensional stability B32B2307/734
• CPC Class Codes: B32B 2307/40 having particular optical properties light or UV resistant B32B2307/71
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/7242 Non-permeable
• CPC Class Codes: B32B 2439/00 Containers; Receptacles closures therefor B32B2435/00
• CPC Class Codes: B32B 2439/40 Closed containers
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08G 2250/00 Compositions for preparing crystalline polymers
• CPC Class Codes: C08G 63/16 Dicarboxylic acids and dihydroxy compounds
• CPC Class Codes: C08G 69/26 derived from polyamines and polycarboxylic acids
• CPC Class Codes: C08J 11/06 without chemical reactions
• CPC Class Codes: C08L 77/12 Polyester-amides

Abstract

An object of the present invention is to provide a multilayer container in which yellowing of a regenerated polyester at the time of recycle is suppressed. Furthermore, another object of the present invention is to provide a method for producing a regenerated polyester from the aforementioned multilayer container. The multilayer container of the present invention includes a polyester resin composition layer containing a polyester resin (X) and an antioxidant; and a polyamide resin composition layer containing a polyamide resin (Y) and a cobalt salt, wherein the polyamide resin (Y) has a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid; 50 mol % or more of the structural unit derived from a diamine is a structural unit derived from xylylenediamine; the content of the antioxidant in the polyester resin composition layer is 0.01 to 1% by mass; and the content of the cobalt salt in the polyamide resin composition layer is 100 to 1,000 ppm as expressed in terms of cobalt.

Claims

1-8. -8. (canceled)

9. A method for producing a regenerated polyester, comprising:

recovering a polyester resin composition from a multilayer container,

wherein the multilayer container comprises

a polyester resin composition layer containing a polyester resin (X) and an antioxidant; and

a polyamide resin composition layer containing a polyamide resin (Y) and a cobalt salt, wherein

the polyamide resin (Y) has a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid, and 50 mol % or more of the structural unit derived from a diamine is a structural unit derived from xylylenediamine;

the content of the antioxidant in the polyester resin composition layer is 0.01 to 1% by mass; and

the content of the cobalt salt in the polyamide resin composition layer is 100 to 1,000 ppm as expressed in terms of cobalt.

10. The method for producing a regenerated polyester according to claim 9, comprising a step of removing the whole or a part of the polyamide resin composition layer from the multilayer container to recover the polyester resin composition layer.

11. The method for producing a regenerated polyester according to claim 10, wherein the removal of the polyamide resin composition layer is conducted by, after milling of the multilayer container, air classification.

12. The method for producing a regenerated polyester according to claim 9, wherein the recovered polyester resin composition is subjected to at least one step selected from the group consisting of a crystallization step and a solid-phase polymerization step.

13. The method for producing a regenerated polyester according to claim 9, wherein the polyester resin (X) has a structural unit derived from a dicarboxylic acid and a structural unit derived from a diol, 50 mol % or more of the structural unit derived from a dicarboxylic acid being a structural unit derived from terephthalic acid;

and 50 mol % or more of the structural unit derived from a diol being a structural unit derived from ethylene glycol.

14. The method for producing a regenerated polyester according to claim 9, wherein the polyester resin (X) has a structural unit derived from a dicarboxylic acid and a structural unit derived from a diol, 90 mol % or more of the structural unit derived from a dicarboxylic acid being a structural unit derived from terephthalic acid;

and 90 mol % or more of the structural unit derived from a diol being a structural unit derived from ethylene glycol.

15. The method for producing a regenerated polyester according to claim 9, wherein the polyamide resin (Y) has a structural unit derived from a diamine and a structural unit derived from a dicarboxylic acid, 80 mol % or more of the structural unit derived from a diamine being a structural unit derived from xylylenediamine;

and 80 mol % or more of the structural unit derived from a dicarboxylic acid being a structural unit derived from adipic acid.

16. The method for producing a regenerated polyester according to claim 9, wherein the antioxidant contains at least one selected from the group consisting of a phenol-based antioxidant and a phosphorus-based antioxidant.

17. The method for producing a regenerated polyester according to claim 9, wherein the antioxidant contains at least a phenol-based antioxidant.

18. The method for producing a regenerated polyester according to claim 9, wherein the content of the polyamide resin (Y) is from 1.0 to 15% by mass relative to a sum total of the polyester resin composition layer and the polyamide resin composition layer.

19. The method for producing a regenerated polyester according to claim 9, wherein the polyamide resin composition layer is sandwiched directly or indirectly between two layers of the polyester resin composition layer.

20. The method for producing a regenerated polyester according to claim 9, wherein the antioxidant is a phenol-based antioxidant.

21. The method for producing a regenerated polyester according to claim 9, wherein the content of the antioxidant in the polyester resin composition layer is 0.1 to 0.5% by mass,

wherein the antioxidant is a phenol-based antioxidant, and

wherein a content of the polyamide resin (Y) relative to a sum total of the polyester resin composition layer and the polyamide resin composition layer is 2.0 to 5.0% by mass.

22. The method for producing a regenerated polyester according to claim 10, wherein the recovered polyester resin composition is subjected to at least one step selected from the group consisting of a crystallization step and a solid-phase polymerization step.

23. The method for producing a regenerated polyester according to claim 10, wherein the recovered polyester resin composition is subjected to a granulation step to form a pellet, a crystallization step, and a solid-phase polymerization step.

24. The method for producing a regenerated polyester according to claim 23, wherein the content of the antioxidant in the polyester resin composition layer is 0.1 to 0.5% by mass,

wherein the antioxidant is a phenol-based antioxidant, and

wherein a content of the polyamide resin (Y) relative to a sum total of the polyester resin composition layer and the polyamide resin composition layer is 2.0 to 5.0% by mass.