Multilayer container, method for manufacturing same, and method for manufacturing reclaimed polyester

Patent metadata

Field	Value
Publication number	US-11858240-B2
Application number	US-202117800752-A
Country	US
Kind code	B2
Filing date	Feb 25, 2021
Priority date	Mar 6, 2020
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

Provided is a multilayer container including a polyester layer containing a polyester resin (X), and a polyamide layer containing a polyamide resin (Y), a yellowing inhibitor (A), and an oxidation accelerator (B). The content of the polyamide resin (Y) is from 0.05 to 7.0 mass % relative to the total amount of all polyamide layers and all polyester layers. The yellowing inhibitor (A) is a dye, and the content of the yellowing inhibitor (A) is from 1 to 30 ppm relative to the total amount of all polyamide layers and all polyester layers.

First claim

The invention claimed is:

1. A multilayer container comprising:
a polyester layer comprising a polyester resin (X); and
a polyamide layer comprising a polyamide resin (Y), a yellowing inhibitor (A), and an oxidation accelerator (B);
a content of the polyamide resin (Y) being from 0.05 to 7.0 mass % relative to a total amount of all polyamide layers and all polyester layers;
the yellowing inhibitor (A) being a dye; and
a content of the yellowing inhibitor (A) being from 1 to 30 ppm relative to the total amount of all polyamide layers and all polyester layers.

2. The multilayer container according to claim 1 , wherein the polyester resin (X) comprises a constituent unit derived from a dicarboxylic acid and a constituent unit derived from a diol, 80 mol % or greater of the constituent unit derived from a dicarboxylic acid being a constituent unit derived from terephthalic acid, and 80 mol % or greater of the constituent unit derived from a diol being a constituent unit derived from ethylene glycol.

3. The multilayer container according to claim 1 , wherein the polyamide resin (Y) comprises a constituent unit derived from a diamine and a constituent unit derived from a dicarboxylic acid, 80 mol % or greater of the constituent unit derived from a diamine being a constituent unit derived from xylylene diamine, and 80 mol % or greater of the constituent unit derived from a dicarboxylic acid being a constituent unit derived from adipic acid.

4. The multilayer container according to claim 1 , wherein the yellowing inhibitor (A) is an anthraquinone-based dye.

5. The multilayer container according to claim 1 , wherein the multilayer container is a hollow multilayer container.

6. The multilayer container according to claim 1 , wherein the multilayer container has a 2 to 5 layer structure, and an outermost layer is a polyester layer.

7. The multilayer container according to claim 1 , wherein the multilayer container has a 3 to 5 layer structure, and the outermost layer and an innermost layer are polyester layers.

8. The multilayer container according to claim 1 , wherein the oxidation accelerator (B) is a compound comprising a transition metal.

9. The multilayer container according to claim 8 , wherein the transition metal is at least one selected from the group consisting of cobalt, iron, manganese, and nickel.

10. The multilayer container according to claim 1 , wherein the polyamide layer further comprises a greening inhibitor (C).

11. The multilayer container according to claim 10 , wherein the greening inhibitor (C) is at least one selected from the group consisting of anthraquinone-based dyes and azo-based dyes.

12. The multilayer container according to claim 1 , wherein the polyamide layer further comprises a polyester resin (Z).

13. The multilayer container according to claim 12 , wherein a content of the polyester resin (Z) in the polyamide layer is from 5 to 70 mass %.

14. A method for manufacturing a multilayer container comprising:
a polyester layer comprising a polyester resin (X); and
a polyamide layer comprising a polyamide resin (Y), a yellowing inhibitor (A), and an oxidation accelerator (B);
a content of the polyamide resin (Y) being from 0.05 to 7.0 mass % relative to a total amount of all polyamide layers and all polyester layers;
the yellowing inhibitor (A) being a dye; and
a content of the yellowing inhibitor (A) being from 1 to 30 ppm relative to the total amount of all polyamide layers and all polyester layers; and
the manufacturing method comprising:
a step 1 of mixing the polyamide resin (Y), the yellowing inhibitor (A), and the oxidation accelerator (B) to prepare a polyamide resin mixture;
a step 2 of co-injection molding the polyamide resin mixture and a polyester resin composition containing the polyester resin (X), and thereby obtaining a multilayer preform; and
a step 3 of blow molding the multilayer preform.

15. The method for manufacturing a multilayer container according to claim 14 , wherein in step 1, a greening inhibitor (C) is further mixed.

16. The method for manufacturing a multilayer container according to claim 14 , wherein in step 1, a polyester resin (Z) is further mixed.

17. The method for manufacturing a multilayer container according to claim 14 , wherein in step 1, a polyamide resin or polyester resin, the yellowing inhibitor (A), and the oxidation accelerator (B) are kneaded and then mixed with the polyamide resin (Y).

18. The method for manufacturing a multilayer container according to claim 14 , wherein the oxidation accelerator (B) is a compound comprising a transition metal.

19. The method for manufacturing a multilayer container according to claim 14 , wherein the yellowing inhibitor (A) is an anthraquinone-based dye.

20. A method for manufacturing a recycled polyester, the method comprising recovering polyester from the multilayer container described in claim 1 .

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• Otsuka Kosuke
• Daito Masayuki
• Yamada Takumi

Classifications

• B32B27/08 Primary

  of synthetic resin · CPC title

• B32B27/20

  using fillers, pigments, thixotroping agents · CPC title

• B32B27/34

  comprising polyamides · CPC title

• B32B27/36

  comprising polyesters · CPC title

• B32B2270/00

  Resin or rubber layer containing a blend of at least two different polymers · CPC title