Biodegradable laminated article and method for producing the same

Patent metadata

Field	Value
Publication number	US-12454627-B2
Application number	US-202218569700-A
Country	US
Kind code	B2
Filing date	Jun 10, 2022
Priority date	Jun 16, 2021
Publication date	Oct 28, 2025
Grant date	Oct 28, 2025

Abstract

A biodegradable laminated article includes: a substrate layer; a first thermoplastic resin (A1) layer located on one side of the substrate layer and containing a polyhydroxyalkanoate resin; and a second thermoplastic resin (A2) layer located on the other side of the substrate layer and containing a polyhydroxyalkanoate resin. The weight per unit area of the first thermoplastic resin (A1) layer is from 10 to 200 g/m 2 , and the weight per unit area of the second thermoplastic resin (A2) layer is from 0.1 to 5 g/m 2 .

First claim

The invention claimed is:

1. A biodegradable laminated article, comprising:
a substrate layer;
a first thermoplastic resin (A1) layer located on one side of the substrate layer and comprising a polyhydroxyalkanoate resin; and
a second thermoplastic resin (A2) layer located on the other side of the substrate layer and comprising a polyhydroxyalkanoate resin, wherein
a weight per unit area of the first thermoplastic resin (A1) layer is from 10 to 200 g/m 2 , and
a weight per unit area of the second thermoplastic resin (A2) layer is from 0.1 to 5 g/m 2 .

2. The biodegradable laminated article according to claim 1 , wherein a weight-average molecular weight of each of the polyhydroxyalkanoate resins is from 15×10 4 to 65×10 4 .

3. The biodegradable laminated article according to claim 1 , wherein each of the polyhydroxyalkanoate resins comprises a polymer having 3-hydroxybutyrate units.

4. The biodegradable laminated article according to claim 3 , wherein each of the polyhydroxyalkanoate resins comprises a copolymer of 3-hydroxybutyrate units and 3-hydroxyhexanoate units.

5. A method for producing the biodegradable laminated article according to claim 1 , the method comprising:
forming at least one of the first thermoplastic resin (A1) layer and the second thermoplastic resin (A2) layer by extrusion lamination or thermal lamination at a temperature that is equal to or higher than a melting point of a resin material and that is less than 30° C. above the melting point.

6. A method for producing the biodegradable laminated article according to claim 1 , the method comprising:
forming a film of an aqueous coating liquid containing a polyhydroxyalkanoate resin on a substrate by applying the aqueous coating liquid to the substrate; and
forming at least one of the first thermoplastic resin (A1) layer and the second thermoplastic resin (A2) layer by heating the film of the aqueous coating liquid to a temperature using at least one technique selected from the group consisting of blowing of hot air, infrared irradiation, ultrasonic irradiation, and contact with a heating roll, wherein the temperature is equal to or higher than a melting point of a resin material and is less than 30° C. above the melting point.

7. A molded article comprising the biodegradable laminated article according to claim 1 .

8. A method for producing the molded article according to claim 7 , the method comprising:
heating at least one of the first thermoplastic resin (A1) layer and the second thermoplastic resin (A2) layer to a surface temperature of from 100° C. to lower than 170° C.

Assignees

• Kaneka Corp

Inventors

• Murashima Kensuke
• Kusakabe Itsuki
• Fujita Masayuki
• Okada Yasunori

Classifications

• C08G2230/00

  Compositions for preparing biodegradable polymers · CPC title

• C08G63/06

  derived from hydroxycarboxylic acids · CPC title

• B32B2553/00

  Packaging equipment or accessories not otherwise provided for · CPC title

• B32B2307/748

  Releasability · CPC title

• B32B2307/718

  Weight, e.g. weight per square meter · CPC title