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EP-4741458-A1 - GAS BARRIER POLYMER RESIN COMPOSITION AND FILM CONTAINING SAME

EP4741458A1EP 4741458 A1EP4741458 A1EP 4741458A1EP-4741458-A1

Abstract

A film manufactured using a polymer resin composition according to the present invention not only has biodegradability, but also has excellent oxygen and water vapor barrier properties and excellent ductility, thereby being used as a food packaging material.

Inventors

  • JEONG, Moon Gon
  • UM, JUN GEUN
  • HEO, Seongbeom
  • PARK, JAEYONG
  • LEE, Chunhwa

Assignees

  • LG Chem, Ltd.

Dates

Publication Date
20260513
Application Date
20241210

Claims (16)

  1. A polymer resin composition comprising polyglycolic acid (PGA) and polybutylene succinate (PBS), wherein a weight ratio of the PGA and PBS is 40:60 to 85:15, and an oxygen transmission rate of a film manufactured using the polymer resin composition is 50 cc/m 2 ·day or less, based on a film thickness of 35 um.
  2. The polymer resin composition of claim 1, comprising 0.01% by weight to 3% by weight of an antioxidant with respect to the total weight of the PGA and PBS, and 0.01% by weight to 3% by weight of a chain extender with respect to the total weight of the PGA and PBS.
  3. The polymer resin composition of claim 1, wherein a weight average molecular weight (Mw) of the PGA is 100,000 to 250,000.
  4. The polymer resin composition of claim 1, wherein a melt index of the PGA (measured at 230°C under a load of 2.16 kg according to ASTM D1238) is 4 g/10 min to 25 g/10 min.
  5. The polymer resin composition of claim 1, wherein a weight average molecular weight (Mw) of the PBS is 100,000 to 250,000.
  6. The polymer resin composition of claim 1, wherein a melt index of the PBS (measured at 190°C under a load of 2.16 kg according to ASTM D1238) is 1 g/10 min to 10 g/10 min.
  7. The polymer resin composition of claim 1, wherein a weight ratio of the PGA and PBS is 40:60 to 80:20.
  8. The polymer resin composition of claim 1, wherein a melt index of the polymer resin composition (measured at 230°C under a load of 2.16 kg according to ASTM D1238) is 4 g/10 min to 25 g/10 min.
  9. A film comprising the polymer resin composition of any one of claims 1 to 8.
  10. The film of claim 9, wherein a thickness of the film is 1 um to 1000 um.
  11. The film of claim 9, wherein an oxygen transmission rate of the film is 5 cc/m 2 ·day or less, based on a film thickness of 35 um.
  12. The film of claim 9, wherein a water vapor transmission rate of the film is 50 g/m 2 ·day or less, based on a film thickness of 35 um.
  13. The film of claim 9, wherein an elongation of the film is 350% or more.
  14. The film of claim 9, wherein an elongation of the film is 400% or more.
  15. The film of claim 9, wherein a tensile strength of the film is 45 MPa to 60 MPa.
  16. The film of claim 9, wherein a yield strength of the film is 30 MPa to 60 MPa.

Description

[Technical Field] Cross-reference to Related Application The present application is based on, and claims priority from, Korean Patent Application No. 10-2024-0036148, filed on March 15, 2024, the disclosure of which is hereby incorporated by reference herein in its entirety. The present invention relates to a gas barrier polymer resin composition having excellent oxygen and water vapor barrier properties and biodegradable properties, and a film including the same. [Background Art] The recent frequent occurrence of natural disasters has made us realize that the environmental pollution and the resulting climate change are serious issues that need to be addressed as a priority. Among them, reducing the use of disposable plastics is an environmental pollution improvement activity that can be practiced in everyday life, and many countries are taking as a matter of policy. As part of this policy, the use of eco-friendly or biodegradable plastics is also recommended, and various plastics which are biodegradable in soil or the ocean are being researched and developed. In the field of food packaging, where plastics account for the majority, it is essential to use materials that are able to block gases such as oxygen and water vapor as food packaging materials in order to prevent deterioration during the distribution process and for long-term preservation, and most of these gas barrier materials are based on petrochemical raw materials, and in many cases, they are non-biodegradable. Accordingly, research and development of food packaging materials based on biodegradable materials that are naturally degradable in soil or the ocean are actively being conducted. Food packaging materials need to minimize the inflow of oxygen and water vapor from the outside in order to prevent oxidation and spoilage of the food thereinside, but it is difficult to make the entire food packaging material biodegradable due to the use of general-purpose biodegradable materials (EVOH, MXD6, etc.) or the additional use of metal layers (Al, aluminum oxide, etc.). Meanwhile, polyglycolic acid (PGA), which is one of the biodegradable polymer materials, has excellent oxygen and water vapor barrier properties, but it has a problem of poor ductility, and therefore, it is difficult to process and to use PGA as a film or sheet for food packaging materials. Accordingly, the present invention relates to a film capable of blocking oxygen and water vapor, in which polybutylene succinate (PBS) is used together with PGA, and it was found that such a film enables the realization of biodegradable food packaging materials, thereby completing the present invention. [Disclosure] [Technical Problem] There is provided a gas barrier polymer resin composition having excellent oxygen and water vapor barrier properties and biodegradable properties. There is also provided a film including the polymer resin composition. [Technical Solution] To solve the above problem, there is provided a polymer resin composition as follows: the polymer resin composition includingpolyglycolic acid (PGA) and polybutylene succinate (PBS),wherein a weight ratio of the PGA and PBS is 40:60 to 85:15, andan oxygen transmission rate of a film manufactured using the polymer resin composition is 50 cc/m2·day or less, based on a film thickness of 35 um. As used herein, the term "PGA" is a biodegradable polymer, and functions to provide oxygen- and water vapor-blocking properties for the polymer resin composition according to the present invention. In addition, as used herein, the term "PBS" functions to provide ductility for the polymer resin composition according to the present invention. In other words, the polymer resin composition according to the present invention may have sufficient ductility along with oxygen- and water vapor-blocking properties by using the PGA and PBS in combination, thereby being used as a food packaging material. Preferably, a weight average molecular weight (Mw) of the PGA is 100,000 to 250,000. When the weight average molecular weight of the PGA is lower than 100,000, extrusion molding may be difficult due to low melt viscosity, and there may be a problem that mechanical properties of a product, such as a molded film, are poor. In addition, when the weight average molecular weight is higher than 250,000, discoloration of the PGA may occur significantly, which may cause a problem in the appearance of a molded product, such as a film, and more energy may be required for melt processing, which makes efficient processing difficult. More preferably, the weight average molecular weight (Mw) of the PGA is 100,000 to 200,000. Further, a melt index of the PGA (measured at 230°C under a load of 2.16 kg according to ASTM D1238) is 4 g/10 min to 25 g/10 min. Preferably, the melt index of the PGA is 5 g/10 min to 20 g/10 min. Preferably, a weight average molecular weight (Mw) of the PBS is 100,000 to 250,000. When the weight average molecular weight of the PBS is lower than 100,0