US-12617593-B2 - Biodegradable film for cigarette packaging

Abstract

Provided is a biodegradable film for cigarette packaging, the film including a first film layer applied such that one surface thereof faces a cigarette product, a third film layer applied such that one surface thereof is exposed to the outside, and a second film layer positioned between the first film layer and the third film layer. In the biodegradable film, the first film layer, the second film layer and the third film layer are each formed with different compositions, and at least one of the first film layer, the second film layer and the third film layer includes a biodegradable material. The biodegradable film has a biodegradation rate of 90% or more after 60 days, and has a heat shrink ratio of 4.0% or more.

Inventors

• Kyoung Hwan OH
• Min Hee HWANG
• Soo Ho Kim
• Man Seok Seo

Assignees

• KT&G CORPORATION

Dates

Publication Date

20260505

Application Date

20221216

Priority Date

20211216

Claims (10)

1. 1 . A biodegradable film for cigarette packaging, the film comprising: a first film layer applied such that one surface thereof faces a cigarette product; a third film layer applied such that one surface thereof is exposed to the outside; and a second film layer positioned between the first film layer and the third film layer, wherein the first film layer, the second film layer and the third film layer are each formed with different compositions, and at least one of the first film layer, the second film layer and the third film layer comprises a biodegradable material; the first film layer comprises non-crystalline polylactic acid, the second film layer comprises a semi-crystalline biodegradable polymer, and the third film layer comprises polyvinyl chloride or polyvinylidene chloride, the second film layer is 90% by volume or more of the biodegradable film, and the biodegradable film has a biodegradation rate of 90% or more after 60 days, and has a heat shrink ratio of 4.0% or more.
2. 2 . The biodegradable film of claim 1 , which has a difference in the heat shrink ratio between a length direction and a width direction of less than 1%.
3. 3 . The biodegradable film of claim 1 , which has oxygen permeability of 1000 cc/(m 2 ·day·atm) or less.
4. 4 . The biodegradable film of claim 1 , which has moisture permeability of 50 g/(m 2 ·day·atm) or less.
5. 5 . The biodegradable film of claim 1 , which has airtightness of 50 ml/sec or less.
6. 6 . The biodegradable film of claim 1 , which has haze of 6.0% or less.
7. 7 . The biodegradable film of claim 1 , wherein the semi-crystalline biodegradable polymer is selected from the group consisting of polylactic acid, polyhydroxyl alkanoate, starch, cellulose materials, polyvinyl alcohol, polycaprolactone, polybutylene adipate terephthalate, polyethylene succinate, polybutylene succinate, polyglycolic acid and combinations thereof.
8. 8 . The biodegradable film of claim 1 , wherein the second film layer comprises a semi-crystalline biodegradable polymer having different properties from the second film layer or the third film layer.
9. 9 . The biodegradable film of claim 1 , wherein the second film layer comprises semi-crystalline polylactic acid.
10. 10 . The biodegradable film of claim 1 , wherein the second film layer has a thickness of 5 μm to 30 μm, and the first film layer and the third film layer each have a thickness of 0.1 μm to 10 μm.

Description

TECHNICAL FIELD The present invention relates to a biodegradable film for cigarette packaging. This application is a National Stage of International Application No. PCT/KR2022/020527 filed on Dec. 16, 2022, claiming priority based on Korean Patent Application Nos. 10-2021-0180288 filed on Dec. 16, 2021, and 10-2022-0175881 filed on Dec. 15, 2022, the entire contents of which are incorporated as a part of the present specification by reference. BACKGROUND ART Synthetic plastics are widely used as a packaging material requiring inexpensive and lightweight properties and the like along with excellent properties. Examples of such synthetic plastics include polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET) and the like. Despite their excellent properties, the synthetic plastics generate many harmful substances during manufacture or incineration, or accumulate without being hardly decomposed due to their chemical and biological stability causing environmental pollution problems. As environmental issues have recently emerged, interests in environmental-friendly biodegradable materials capable of replacing the synthetic plastics are increasing. As materials currently used mainly for a cigarette packaging material, an open box-type paper packaging material is used as a container for containing a cigarette product, and, in order to maintain quality of the product for hydration and oxidation degradation, outside the paper packaging material is seal packaged using a film. As a currently commercialized packaging material for external sealing, an OPP film is mainly used. The OPP film is a petroleum-based plastic material and is not subject to separate dispose, and is mostly disposed as general waste. The OPP film also has environmental pollution issues in terms that it is not highly biodegradable, and studies on alternate materials having high degradability while maintaining the same functionalities as the OPP film have been actively conducted in the art. The inventors of the present invention have recognized the technical challenges for a packaging material for external sealing of a cigarette product described above, and completed the present invention after continuous studies on materials capable of replacing the OPP film. PRIOR ART DOCUMENT [Patent Document] (Patent Document 1) Korean Laid-open Patent Publication No. 10-2011-0057500 DISCLOSURE Technical Problem In a biodegradable film for cigarette packaging, in order to replace an existing OPP film with a biodegradable material, the present invention is directed to providing a biodegradable film capable of enhancing workability as well as heat adhesion and barrier properties by supplementing inferior functionalities other than biodegradability of a biodegradable material. Technical Solution According to a first aspect of the present invention, the present invention provides a biodegradable film for cigarette packaging, the film including a first film layer applied such that one surface thereof faces a cigarette product, a third film layer applied such that one surface thereof is exposed to the outside, and a second film layer positioned between the first film layer and the third film layer. According to one embodiment of the present invention, the first film layer, the second film layer and the third film layer are each formed with different compositions, and at least one of the first film layer, the second film layer and the third film layer includes a biodegradable material. According to one embodiment of the present invention, the biodegradable film has a biodegradation rate of 90% or more after 60 days, and has a heat shrink ratio of 4.0% or more. According to one embodiment of the present invention, the biodegradable film has a difference in the heat shrink ratio between a length direction and a width direction of less than 1%. According to one embodiment of the present invention, the biodegradable film has oxygen permeability of 1000 cc/(m2·day·atm) or less. According to one embodiment of the present invention, the biodegradable film has moisture permeability of 50 g/(m2·day·atm) or less. According to one embodiment of the present invention, the biodegradable film has airtightness of 50 ml/sec or less. According to one embodiment of the present invention, the biodegradable film has haze of 6.0% or less. According to one embodiment of the present invention, the biodegradable material is selected from the group consisting of polylactic acid, polyhydroxyl alkanoate, starch, cellulose materials, polyvinyl alcohol, polycaprolactone, polybutylene adipate terephthalate, polyethylene succinate, polybutylene succinate, polyglycolic acid and combinations thereof. According to one embodiment of the present invention, a layer including the most of the biodegradable material among the first film layer, the second film layer and the third film layer is the second film layer. According to one embodiment of the present invention,