KR102820364B1 - Biodegradable film for cigarette packaging - Google Patents

Abstract

A biodegradable film for tobacco packaging is provided, comprising a first film layer applied so that one side faces a tobacco product, a third film layer applied so that one side 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 composed of 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 a heat shrinkage rate of 4.0% or more.

Description

{BIODEGRADABLE FILM FOR CIGARETTE PACKAGING}

The present invention relates to a biodegradable film for cigarette packaging.

Synthetic plastics are widely used as packaging materials that require excellent physical properties as well as cheap and light characteristics. Examples of such synthetic plastics include polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Despite their excellent physical properties, these synthetic plastics generate many hazardous substances during manufacturing or incineration, and they accumulate without being decomposed due to their chemical and biological instability, causing environmental pollution problems. Recently, as environmental issues have come to the fore, interest in eco-friendly biodegradable materials that can replace these synthetic plastics has been increasing.

Currently, the main material used for cigarette packaging is open box-type paper packaging as a container for containing the cigarette product, and a film is used on the outside of the paper packaging to seal the packaging in order to maintain the quality of the product against moisture content and oxidation degradation. Currently, the main commercialized external sealing packaging material is OPP film. The OPP film is a petroleum-based plastic material, and since it is not subject to separate disposal, it is mostly disposed of as general waste. The OPP film also has an environmental pollution problem because it is not highly biodegradable, and in the relevant technical field, research is actively being conducted on an alternative material that maintains the same functionality as the OPP film but is highly biodegradable.

The inventor of the present invention recognized the technical problem of the packaging material for external sealing of the above-described tobacco product, and completed the present invention after continuous research on a material that can replace the OPP film.

Republic of Korea Patent Publication No. 10-2011-0057500

In biodegradable films for cigarette packaging, the present invention aims to provide a biodegradable film that can improve workability as well as heat sealability and barrier properties by supplementing the thermal functionality of biodegradable materials other than biodegradability in order to replace existing OPP films with biodegradable materials.

According to the first aspect of the present invention,

The present invention provides a biodegradable film for tobacco packaging, comprising: a first film layer applied so that one side faces a tobacco product; a third film layer applied so that one side is exposed to the outside; and a second film layer positioned between the first film layer and the third film layer.

According to one specific example of the present invention, the first film layer, the second film layer, and the third film layer are each composed of 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 specific example of the present invention, the biodegradable film has a biodegradation rate of 90% or more after 60 days and a heat shrinkage rate of 4.0% or more.

According to one specific example of the present invention, the biodegradable film has a difference in thermal shrinkage between the longitudinal direction and the width direction of less than 1%.

According to one specific example of the present invention, the biodegradable film has an oxygen permeability of 1000 cc/(m ² ·day ·atm) or less.

According to one specific example of the present invention, the biodegradable film has a moisture permeability of 50 g/(m ² ·day ·atm) or less.

According to one specific example of the present invention, the biodegradable film has an airtightness of 50 ml/sec or less.

According to one specific example of the present invention, the biodegradable film has a haze of 6.0% or less.

According to one specific embodiment of the present invention, the biodegradable material is selected from the group consisting of polylactic acid, polyhydroxyl alkanoate, starch, cellulosic materials, polyvinyl alcohol, polycaprolactone, polybutylene adipate terephthalate, polyethylene succinate, polybutylene succinate, polyglycolic acid, and combinations thereof.

According to one specific example of the present invention, among the first film layer, the second film layer, and the third film layer, the layer containing the largest amount of biodegradable material is the second film layer.

According to one specific embodiment of the present invention, the second film layer is at least 80 volume% of the biodegradable film.

According to one specific embodiment of the present invention, the first film layer or the third film layer includes a biodegradable material having different properties from the second film layer.

According to one specific example of the present invention, the first film layer or the third film layer includes a polyvinyl compound, an ethylene vinyl alcohol copolymer, an acrylic compound, a sealant compound, an OP coating compound, a urethane compound, a silicone compound, an epoxy compound, nanocellulose, an inorganic material, or a combination thereof.

According to one specific example of the present invention, the second film layer comprises semi-crystalline polylactic acid, and the first film layer or the third film layer comprises amorphous polylactic acid.

According to one specific example of the present invention, the first film layer or the third film layer includes polyvinyl alcohol, polyvinyl chloride or polyvinylidene chloride.

According to one specific example of the present invention, 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.

A biodegradable film according to one specific example of the present invention is a three-layer biodegradable film comprising a biodegradable substrate layer containing a biodegradable material as the center and a film layer such as a heat-sealing layer or a barrier coating layer, and has excellent functionality in terms of biodegradation rate, heat shrinkage rate, oxygen permeability, moisture permeability, airtightness, haze, etc., and can replace existing OPP films for cigarette packaging.

FIG. 1 is a drawing schematically illustrating the configuration of a biodegradable film for cigarette packaging according to one specific example of the present invention.

Hereinafter, specific examples will be described in detail with exemplary drawings. When adding reference signs to components in each drawing, it should be noted that the same components are given the same signs as much as possible even if they are shown in different drawings. In addition, when describing specific examples, if it is determined that a specific description of a related known configuration or function hinders understanding of the specific example, the detailed description will be omitted.

Also, in describing components of a specific example, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

Components included in one specific example and components that include common functions will be described using the same name in other specific examples. Unless otherwise stated, the description described in one specific example can be applied to other embodiments, and specific descriptions will be omitted to the extent of overlap.

The present invention relates to a biodegradable film for packaging tobacco, and more specifically, to a biodegradable film for sealing and packaging the outside of a paper packaging material that directly contains a tobacco product. FIG. 1 provides a drawing schematically illustrating a configuration of a biodegradable film for packaging tobacco according to one embodiment of the present invention. As illustrated in FIG. 1, the biodegradable film according to one embodiment of the present invention includes a first film layer (10), a second film layer (20), and a third film layer (30). Since the biodegradable film is divided into a side facing the tobacco product and a side exposed to the outside when packaging a tobacco product, each film layer is indicated as a first film layer (10), a second film layer (20), a third film layer (30), etc. When packaging a tobacco product, one side of the first film layer (10) faces the tobacco product. Here, the tobacco product may also mean a state in which the tobacco product is packaged in paper packaging material, etc. The third film layer (30) has one side exposed to the outside when packaging a tobacco product. The second film layer (20) is positioned between the first film layer (10) and the third film layer (30). In addition to the second film layer (20), one or more additional film layers may be applied between the first film layer (10) and the third film layer (30) as needed.

A biodegradable film according to one specific embodiment of the present invention has excellent functionality to the extent that it can replace existing OPP films. According to one specific embodiment of the present invention, the biodegradable film has a biodegradation rate of 90% or more after 60 days. The biodegradation rate applies the ISO 14855-1 soil biodegradability measurement test standard, and the amount of carbon dioxide generated by biodegrading a film specimen under controlled composting and aerobic conditions was measured. In general, a material is considered biodegradable if it is decomposed by 90% or more compared to a reference material (cellulose). The biodegradable film can exhibit a high biodegradation rate even in a short period of 60 days, despite being a multilayer film.

A biodegradable film according to one embodiment of the present invention has high biodegradability while also having excellent barrier properties so that the quality of the tobacco product inside is not degraded. In general, biodegradable materials are often vulnerable to external environments such as moisture and air in order to have a certain level of degradability or higher. Therefore, in order to manufacture a biodegradable film for tobacco packaging using a biodegradable material, a functional film layer capable of blocking external environments such as moisture and air is required, and in a multilayer biodegradable film according to one embodiment of the present invention, such a functional film layer is included in layers other than the film layer including the biodegradable material.

According to one specific example of the present invention, the biodegradable film has an oxygen permeability of 1000 cc/(m ² ·day ·atm) or less. Specifically, the oxygen permeability may be 1000 cc/(m ² day atm) or less, 900 cc/(m ² day atm) or less, 800 cc/(m ² day atm) or less, 700 cc/(m ² day atm) or less, 600 cc/(m ² day atm) or less, 500 cc/(m ² day atm) or less, 400 cc/(m ² day atm) or less, 300 cc/(m ² day atm) or less, 200 cc/(m ² day atm) or less, 100 cc/(m ² day atm) or less, or 50 cc/(m ² day atm) or less. The above oxygen permeability can be a value measured at 23℃ and 0RH% using the ASTM D 3985 (Method M, Pressure Method) method, and can be measured using a measuring device such as a Gas Transmission Rate Tester (OX-TRAN 702 product of Mocon, USA).

According to one specific example of the present invention, the biodegradable film has a moisture permeability of 50 g/(m ² day atm) or less. Specifically, the moisture permeability may be 50 g/(m ² day atm) or less, 45 g/(m ² day atm) or less, 40 g/(m ² day atm) or less, 35 g/(m ² day atm) or less, 30 g/(m ² day atm) or less, 25 g/(m ² day atm) or less, 20 g/(m ² day atm) or less, 15 g/(m ² day atm) or less, or 10 g/(m ² day atm) or less. The above moisture permeability may be a value measured at 38℃ and 100RH%, and may be measured using a measuring device such as a moisture permeability measuring device (PERMATRAN-W700 product from MOCON, USA).

According to one specific example of the present invention, the biodegradable film has an airtightness of 50 ml/sec or less. Specifically, the airtightness may be 50 ml/sec or less, 45 ml/sec or less, 40 ml/sec or less, 35 ml/sec or less, 30 ml/sec or less, 25 ml/sec or less, 20 ml/sec or less, 15 ml/sec or less, or 10 ml/sec or less. The airtightness was measured using a device for measuring air leakage of a cigarette pack OPP film. The relevant airtightness measures the sealing state and leakage state of the film using air pressure. This can be measured using a measuring device such as an airtightness measuring device (KADIEN ALT-2 product of KADIEN, Korea).

A machine for packaging a film for products such as cigarette packs is a high-speed packaging machine that can produce about 500 packs per minute. The film is generally supplied in the form of a long piece of fabric (e.g., a roll) and is cut to the required length to package the product. During this series of processes, the film must not only maintain the functionality related to the biodegradability or barrier properties described above, but also be capable of maintaining excellent workability or productivity, such as reducing the defect rate of the packaging, even within a high-speed packaging machine. In this regard, heat sealability may be required so that the applied film can adhere well to the product, or heat shrinkage may be required so that the film adheres well to the outer surface of the product without a bumpy surface after the packaging process. In addition, as described above, in a continuous packaging process that is performed at high speed, the friction coefficient of the film surface may be important in order to manufacture a large quantity of products without defects. A biodegradable film according to one specific example of the present invention has high processability without product defects even in a high-speed packaging machine that packages products such as cigarette packs.

In terms of workability or fairness of a product, heat shrinkage may also be an important factor. If a coating layer is added to a film fabric made of a biodegradable material to secure functionality, heat shrinkage may decrease. If the film is adhered to the surface of the pack after packaging a cigarette pack, etc., not only is transportation easy, but the appearance of the package can also be improved by reducing the uneven surface on the outer surface. Therefore, a certain level of heat shrinkage is required as a characteristic of the biodegradable film in order to increase the adhesion of the film after packaging. According to one specific example of the present invention, the biodegradable film has a heat shrinkage rate of 4.0% or more, specifically 4.5% or more, and more specifically 5.0% or more. The above heat shrinkage rate was calculated by applying KS M ISO 17555, specifically, preparing a test piece with a width of about 20 mm and a length of about 150 mm (same in MD and TD directions), marking a mark at a distance of about 100 mm from the center, placing it in a hot air oven maintained at a temperature of 120°C, heat-treating it for 15 minutes, and then measuring the length using the following mathematical formula 2.

[Mathematical formula 2]

Thermal shrinkage (%) = (L _i -L _t ) / L _i × 100

In the above mathematical expression 2, L _i denotes the distance between gauge points before heat treatment, and L _t denotes the distance between gauge points after heat treatment. The length is a value selected by considering both the longitudinal direction or the machine direction (MD direction) when supplying materials and the width direction or the cross direction (CD direction) when supplying materials, and the lower value among the two. Since the lower value among the thermal shrinkage rates in the longitudinal direction and the width direction is considered, the biodegradable film according to one embodiment of the present invention can secure a thermal shrinkage rate greater than the above value in all directions. According to one embodiment of the present invention, the biodegradable film has a difference in the thermal shrinkage rates in the longitudinal direction and the width direction of less than 1%. The thermal shrinkage rate difference is calculated based on a larger value among the thermal shrinkage rates in the longitudinal direction and the width direction. Specifically, the thermal shrinkage rate difference may be less than 1%, less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, or less than 0.5%.

When the functional properties such as barrier properties, thermal adhesive properties, and coefficient of dynamic friction described above are imparted to the biodegradable material, the transparency of the film may be significantly reduced. Considering that information on tobacco products is mainly displayed on cigarette packs, etc., the higher the transparency of the biodegradable film used as a packaging material covering such cigarette packs, the greater its utility. According to one specific example of the present invention, the biodegradable film has a haze of 6.0% or less, specifically 5.5% or less, and more specifically 5.0% or less. The haze was measured using Haze gard-2 of Toyoseiki. The biodegradable film according to one specific example of the present invention has a low haze value and thus can secure a certain level or more of transparency, and has excellent adhesion to a cigarette pack, thereby providing high visibility of the internal packaging object.

According to one embodiment of the present invention, a biodegradable film having the above-described functionality comprises a first film layer, a second film layer, and a third film layer. The first film layer, the second film layer, and the third film layer are each separate layers and are not only positionally distinguished as described above, but also distinguished by the components forming the film layers or their compositions. According to one embodiment of the present invention, the first film layer, the second film layer, and the third film layer are each composed of 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 film layer containing the largest amount of the biodegradable material can basically be a support film layer, and another film layer can be introduced through coating centered on the film layer. Therefore, in this specification, the film layer containing the largest amount of the biodegradable material is also expressed as a biodegradable substrate layer.

The biodegradable material may be a material having a high biodegradation rate and a certain level of durability when forming a film, and may broadly include biodegradable biomass materials, biodegradable plastic materials, etc. According to one specific example of the present invention, the biodegradable material is selected from the group consisting of polylactic acid (PLA), polyhydroxyl alkanoate (PHA), starch, cellulose-based materials, polyvinyl alcohol (PVA), polycaprolactone (PCL), polybutylene adipate terephthalate (PBAT), polyethylene succinate (PES), polybutylene succinate (PBS), polyglycolic acid (PGA), and combinations thereof. Here, the cellulosic material may be cellulose, a cellulose derivative or regenerated cellulose. According to one specific example of the present invention, the support film layer or the biodegradable substrate layer may contain 70 wt% or more, specifically 80 wt% or more, and more specifically 90 wt% or more of the biodegradable material based on the total weight of the layer.

According to one specific example of the present invention, the remaining coating layer, excluding the support film layer or the biodegradable substrate layer, includes a biodegradable material having different properties or includes a polyvinyl compound, an ethylene vinyl alcohol copolymer (EVOH), an acrylic compound, a sealant compound, an OP coating compound, a urethane compound, a silicone compound, an epoxy compound, nano-cellulose, an inorganic compound or a combination thereof to add additional functionality. The above materials supplement the insufficient functionality of the biodegradable substrate layer.

The biodegradable material introduced into the coating layer may have different properties from those of the supporting film layer or the biodegradable substrate layer. According to one specific example of the present invention, the supporting film layer or the biodegradable substrate layer includes a semi-crystalline biodegradable polymer (for example, semi-crystalline polylactic acid), and the coating layer includes an amorphous biodegradable polymer (for example, amorphous polylactic acid). Here, amorphousness means that there is no regularity in the atomic arrangement between atoms constituting the polymer material, and semi-crystalline means that there is regularity in the atomic arrangement between some atoms constituting the polymer material. In terms of the nature of the polymer material, it is difficult to have 100% crystallinity, and therefore, a biodegradable polymer that is not amorphous may be semi-crystalline.

The above materials can be broadly classified functionally into a thermal bonding layer and a barrier coating layer. A biodegradable film according to one embodiment of the present invention includes a thermal bonding layer and a barrier coating layer together with a biodegradable substrate layer. The biodegradable substrate layer, the thermal bonding layer, and the barrier coating layer may be disposed without overlapping among the first film layer, the second film layer, and the third film layer, respectively. Specifically, the second film layer may be a biodegradable substrate layer, and the first film layer or the third film layer may be a thermal bonding layer or a barrier coating layer. More specifically, the first film layer may be a thermal bonding layer, the second film layer may be a biodegradable substrate layer, and the third film layer may be a barrier coating layer. According to one embodiment of the present invention, the thermal bonding layer or the barrier coating layer may also include a biodegradable material, but may not contain a larger amount than the biodegradable substrate layer.

The above thermal bonding layer includes a polyvinyl compound, an ethylene vinyl alcohol copolymer, an acrylic compound, a sealant compound, an OP coating compound or a combination thereof, and the barrier coating layer includes a polyvinyl compound, an ethylene vinyl alcohol copolymer, an acrylic compound, a urethane compound, a silicone compound, an epoxy compound, nanocellulose, an inorganic material or a combination thereof. When the materials of the thermal bonding layer or the barrier coating layer are used in combination, they may be mixed and used in one layer, or may be separated into two or more layers and configured with different compositions for each layer. For example, when one layer of the barrier coating layer is configured by depositing an inorganic material, an additional barrier coating layer can be formed on the inorganic layer through the remaining components. The compound included in the thermal bonding layer or the barrier coating layer is not particularly limited as long as it is a material that can be generally used in the relevant technical field. The above inorganic material may be, for example, Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , ITO, IZO, ATO, ZnO-Al, Nb ₂ O ₃ , SnO, MgO, etc., and is not particularly limited as long as it is a material that can be generally used in the relevant technical field.

The above polyvinyl compound includes a compound in which a hydroxyl group or a halogen group is substituted in a polyvinyl compound. The polyvinyl compound may include compounds such as polyvinyl alcohol, polyvinyl chloride, and polyvinylidene chloride.

The above acrylic compound may be an acrylic resin, and is not particularly limited as long as it is a material that can be generally used in the relevant technical field. The acrylic resin may be a water-dispersed emulsion-type acrylic resin, and may be an acrylic resin including at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an N-methylol group, an alkoxymethylol group, an acrylate group, and an acryloyl group. For example, the acrylic resin may be obtained by polymerizing a (meth)acrylic monomer alone, or may be obtained by copolymerizing a (meth)acrylic monomer with at least one copolymerizable monomer capable of copolymerizing the (meth)acrylic monomer.

The above (meth)acrylic monomers include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, There are 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, allyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, etc., and these can be used alone or in a mixture of two or more.

Examples of the copolymerizable monomer include carboxyl group-containing ethylenically unsaturated monomers such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid; vinyl monomers such as acrylamide, acrylonitrile, vinyl acetate, ethylene, propylene, isobutylene, butadiene, isoprene, and chloroprene; epoxy group-containing ethylenically unsaturated monomers such as glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, allyl glycidyl ether, and 3,4-epoxy cyclohexyl methyl (meth)acrylate; and hydroxyl group-containing ethylenically unsaturated monomers such as hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate. These may be used alone or in a mixture of two or more. According to one specific example of the present invention, as the copolymerizable monomer, a carboxyl group-containing ethylenically unsaturated monomer such as (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, or fumaric acid can be used.

The above-described compound included in the above-described heat-sealing layer or barrier coating layer may be contained in an appropriate amount to obtain the desired functionality of each film layer. According to one specific example of the present invention, the above-described component may be contained in an amount of 20 wt% to 70 wt% in the film layer including it.

The above biodegradable film can be adjusted to a thickness suitable for use as cigarette packaging while securing the above-described functionality. According to one specific example of the present invention, the biodegradable film has a thickness of 10 ㎛ to 50 ㎛. Specifically, the thickness of the biodegradable film may be 10 ㎛ or more, 11 ㎛ or more, 12 ㎛ or more, 13 ㎛ or more, 14 ㎛ or more, 15 ㎛ or more, and 50 ㎛ or less, 45 ㎛ or less, 40 ㎛ or less, 35 ㎛ or less, 30 ㎛ or less, or 25 ㎛ or less. The thickness of each film layer can be adjusted as follows depending on the biodegradable substrate layer, the heat adhesive layer, or the barrier coating layer. According to one specific example of the present invention, the biodegradable substrate layer has a thickness of 5 µm to 30 µm, 10 µm to 30 µm, or 15 µm to 25 µm, and the remaining coating layers excluding the biodegradable substrate layer have a thickness of 0.1 µm to 10 µm, 0.3 µm to 5 µm, or 0.5 µm to 2 µm.

According to one specific example of the present invention, the support film layer or the biodegradable substrate layer may be comprised of 80% by volume or more, 85% by volume or more, or 90% by volume or more in the biodegradable film. Each film layer may have almost the same area, so that the volume ratio may be proportional to the thickness ratio of each film layer. When there are two coating layers other than the biodegradable substrate layer, each of the remaining coating layers may occupy 10% by volume or less, 9% by volume or less, 8% by volume or less, 7% by volume or less, 6% by volume or less, or 5% by volume or less in the biodegradable film.

According to one specific embodiment of the present invention, the support film layer or the biodegradable substrate layer is the second film layer. By making the second film layer located at the center of the biodegradable film the biodegradable substrate layer, the ratio of the biodegradable substrate layer can be increased. According to one specific embodiment of the present invention, the second film layer is 80% by volume or more of the biodegradable film. According to one specific embodiment of the present invention, the first film layer or the third film layer includes a biodegradable material having different properties from the second film layer. According to one specific embodiment of the present invention, the first film layer or the third film layer includes a polyvinyl compound, an ethylene vinyl alcohol copolymer, an acrylic compound, a sealant compound, an OP coating compound, a urethane compound, a silicone compound, an epoxy compound, nanocellulose, an inorganic material, or a combination thereof. According to one specific embodiment of the present invention, the second film layer includes semicrystalline polylactic acid, and the first film layer or the third film layer includes amorphous polylactic acid. According to one specific embodiment of the present invention, the first film layer or the third film layer comprises polyvinyl alcohol, polyvinyl chloride or polyvinylidene chloride. According to one specific embodiment of the present invention, the first film layer comprises amorphous polylactic acid, and the third film layer comprises polyvinyl alcohol, polyvinyl chloride or polyvinylidene chloride. In one specific embodiment of the present invention, the second film layer has a thickness of 5 ㎛ to 30 ㎛, and the first film layer and the third film layer each have a thickness of 0.1 ㎛ to 10 ㎛.

Hereinafter, the composition of the present invention and the effects thereof will be described in more detail through examples and comparative examples. However, these examples are intended to explain the present invention more specifically, and the scope of the present invention is not limited to these examples.

Example

Example 1

A semi-crystalline polylactic acid film (TE90C product of SKC) with a thickness of about 21 ㎛ was prepared as a second film layer. In order to form a first film layer applied so that one side thereof faces the tobacco product on the second film layer, an amorphous polylactic acid (product of SKC) with a thickness of about 1 ㎛ was coated on the second film layer. In order to form a third film layer applied so that one side thereof is exposed to the outside on the second film layer, a polyvinylidene chloride (product of Yulchon) with a thickness of about 1 ㎛ was coated on the other side of the second film layer on which the first film layer was not coated. The manufactured three-layer biodegradable film was used to package tobacco products by a heat seal method in a cigarette packaging machine. The biodegradable film contained about 90 volume% or more of a polylactic acid film with a high biodegradation rate, thereby securing functionality as a biodegradable film.

Comparative Example 1

A two-layer biodegradable film was manufactured in the same manner as in Example 1, except that the first film layer was not coated on the second film layer, and a third film layer was coated with amorphous polylactic acid (SKC product) having a thickness of about 1 ㎛.

Comparative Example 2

A three-layer biodegradable film was manufactured in the same manner as in Example 1, except that an OP coating compound (ECOBY-OPP product from Yulchon Co.) with a thickness of approximately 1 ㎛ was coated as the third film layer.

Experimental example

In order to evaluate whether the biodegradable films manufactured in Example 1 and Comparative Examples 1 and 2 have properties suitable for packaging cigarettes, heat shrinkage, oxygen permeability, moisture permeability, airtightness, and haze were measured, and the results are shown in Table 1 below. The method for measuring each property basically follows the general method in the relevant technical field, and specifically, the measurements were made according to the method specified in the above-described contents.

Example 1 Comparative Example 1 Comparative Example 2 Thermal shrinkage 5.2 6.2 4.4 Difference in thermal shrinkage (%) 0.1 2.6 1.1 Oxygen permeability (cc/(m ² ·day ·atm)) 0.26 1000 1.44 Moisture permeability (g/(m ² ·day ·atm)) 3.79 385.1 355.1 Confidentiality(ml/sec) 0 78 130 Haze(%) 3.9 2.1 22.5

* The above heat shrinkage ratio is selected as the lower numerical value among the heat shrinkage ratios in the length direction and width direction, and the difference in the above heat shrinkage ratios is the value obtained by subtracting the lower numerical value from the higher numerical value among the heat shrinkage ratios in the length direction and width direction.

According to Table 1 above, it can be confirmed that a biodegradable film having suitable properties for packaging a tobacco product, as in Example 1, can be manufactured by filling the second film layer with a biodegradable film of about 90% by volume or more and introducing the first film layer and the third film layer with appropriate materials. In addition, a biodegradable film having such properties may be difficult to achieve without either one of the first film layer and the third film layer, as in Comparative Example 1, and may be difficult to achieve even by coating with a coating material well known in the coating field, as in Comparative Example 2.

Although the specific examples have been described above by way of limited specific examples and drawings, those skilled in the art will appreciate that various modifications and variations may be made from the above teachings. For example, appropriate results may be achieved even if the described techniques are performed in a different order than the described method, and/or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different form than the described method, or are replaced or substituted by other components or equivalents.

100: Biodegradable film for cigarette packaging
10: 1st film layer
20: Second film layer
30: Third film layer

Claims (14)

As a biodegradable film for cigarette packaging,
A first film layer applied with one side facing the tobacco product;
A third film layer applied so that one side is exposed to the outside; and
A second film layer positioned between the first film layer and the third film layer;
The first film layer, the second film layer, and the third film layer are each composed of different compositions, and at least one of the first film layer, the second film layer, and the third film layer includes a biodegradable polymer.
The above biodegradable film has a biodegradation rate of 90% or more after 60 days and a heat shrinkage rate of 4.0% or more.
The first film layer comprises amorphous polylactic acid, the second film layer comprises semi-crystalline polylactic acid, and the third film layer comprises polyvinylidene chloride.
A biodegradable film for cigarette packaging, wherein the second film layer comprises at least 90% by volume of the biodegradable film. In claim 1,
A biodegradable film for cigarette packaging, characterized in that the above biodegradable film has a difference in thermal shrinkage between the longitudinal direction and the width direction of less than 1%. In claim 1,
The above biodegradable film is a biodegradable film for cigarette packaging, characterized in that the oxygen permeability is 1000 cc/(m ² ·day ·atm) or less. In claim 1,
The above biodegradable film is a biodegradable film for cigarette packaging, characterized in that the biodegradable film has a moisture permeability of 50 g/(m ² ·day·atm) or less. In claim 1,
The above biodegradable film is a biodegradable film for cigarette packaging, characterized in that the airtightness is 50 ml/sec or less. In claim 1,
The above biodegradable film is a biodegradable film for cigarette packaging, characterized in that the biodegradable film has a haze of 6.0% or less. In claim 1,
A biodegradable film for cigarette packaging, characterized in that the biodegradable polymer is selected from the group consisting of polylactic acid, polyhydroxyl alkanoate, starch, cellulosic materials, polyvinyl alcohol, polycaprolactone, polybutylene adipate terephthalate, polyethylene succinate, polybutylene succinate, polyglycolic acid and combinations thereof. delete delete delete delete delete delete In claim 1,
The second film layer has a thickness of 5 μm to 30 μm,
A biodegradable film for cigarette packaging, characterized in that the first film layer and the third film layer each have a thickness of 0.1 ㎛ to 10 ㎛.