KR20220074371A - Oxygen penetrating-proof lid film for liquid food container - Google Patents

Abstract

The present invention is an oxygen barrier layer 110; and an adhesive layer 120 provided under the oxygen barrier layer 110 and adhered to the flange portion 11 of the cup container 10; 12) relates to a lid film 100 for a liquid food container that seals, wherein the oxygen barrier layer 110 is characterized in that polypropylene (PP) is coated with polyvinyl alcohol (PVOH), which uses aluminum The present invention relates to a lid for a liquid food container that can secure excellent heat resistance and adhesiveness even when minimizing the temperature, can be recycled, and can be easily incinerated. In addition, in the present invention, the oxygen permeability value of the oxygen barrier layer 110 is a coating film thickness of polyvinyl alcohol (PVOH) to have a value of 200cc/m2, day, atm or less at RH75% or crosslinked, and a multilayer material It is laminated with aluminum to provide oxygen barrier properties that can be replaced by aluminum, and the lid film for liquid food containers of the present invention is the above-mentioned in the process of transferring heat and pressure to the hot press of the thermal bonding machine when the lid is thermally bonded to the cup container. The surface layer 130 and the oxygen barrier layer 110 composed of two layers are partially coated with a silicone-acrylic compound on the surface of the film or partly to be sealed so that the surface layer 130 and the oxygen barrier layer 110 are deformed by heat or are separated when a single lead is supplied. Or, it is characterized in that the surface of the lead film is embossed to facilitate separation when supplying one lead, and the protrusion height by embossing is 50 to 150 μm.

Description

Oxygen barrier lead film for liquid food container {OXYGEN PENETRATING-PROOF LID FILM FOR LIQUID FOOD CONTAINER}

The present invention relates to a lid for a liquid food container, and more specifically, a liquid food container that can secure excellent oxygen barrier properties, water resistance, heat resistance and adhesion without using aluminum, can be recycled, and can be easily incinerated. It is about the dragon lead.

A cup container made of polypropylene material, which is sold with disposable coffee, etc., has a lid attached to the upper flange portion of the cup container in order to close the upper opening part thereof.

On the other hand, the user removes the lead to consume the drink contained in the cup container, or consumes the drink using a straw that can penetrate the lead.

Conventionally, a lid composed of printing/aluminum foil/adhesive layer or PET/printing/aluminum foil/adhesive layer is used, and the adhesive layer is a polyolefin-based film, hot melt, and easy-peelable for thermal adhesion to cup containers or convenient opening. ) film can be used. In the process of incinerating and disposing of lead packaging materials that are discarded after consumption by consumers due to the component of aluminum foil, which is a component of the lead, high temperature heat of incineration is required due to the nature of the metal material, resulting in serious environmental pollution.

Accordingly, there is an urgent need to develop a lead such as a cup container that does not use aluminum or minimizes its use.

[Prior literature]

Patent Document 1: Korean Patent Registration No. 10-1458867 (2014.11.11)

An object of the present invention is to provide a novel lead that does not use aluminum at all or minimizes its use so that it can be recycled and can be easily incinerated.

The lead film for a liquid food container according to the present invention includes an oxygen barrier layer 110; and an adhesive layer 120 provided under the oxygen barrier layer 110 and adhered to the flange portion 11 of the cup container 10; 12) As the lead film 100 for a liquid food container for sealing, the oxygen barrier layer 110 may be polypropylene (PP) coated with polyvinyl alcohol (PVOH).

Polyvinyl alcohol (PVOH) is a material that has a hydroxyl group (-OH) and has high oxygen barrier properties and a hydrophilic property that dissolves in water. With hot water, PVOH is dissolved and only a film is left, which can facilitate recyclability.

In the lead film for a liquid food container according to the present invention, the adhesive layer 120 may be made of the same material as the flange portion of the cup container.

In the lead film for a liquid food container according to the present invention, the adhesive layer 120 maintains an appropriate adhesive force with the flange portion of the cup container so that the consumer can easily remove it when eating. It may be a mixed material in which different materials, which are materials, are mixed.

In the lead film for a liquid food container according to the present invention, the oxygen barrier layer 110 adheres to the adhesive layer 120, and the coating of polyvinyl alcohol (PVOH) itself, which acts as an oxygen barrier, is directly exposed to the outside. It is oriented with the adhesive layer 120 to prevent it from happening.

The lead film for a liquid food container according to the present invention may further include a surface layer 130 provided on the oxygen barrier layer 110 to reinforce the heat resistance of the lead film.

In the lead film for a liquid food container according to the present invention, the surface layer 130 may be made of the same material as the flange portion of the cup container, or may be made of polyethylene terephthalate (PET) or nylon.

In the lead film for a liquid food container according to the present invention, the polyvinyl alcohol (PVOH) coated surface of the oxygen barrier layer 110 is oriented in a direction in contact with the surface layer 130 to adhere to the adhesive layer 120 Orienting the oxygen barrier layer in a direction may be relatively advantageous.

In general, the water activity of the headspace in the cup beverage product is at a level of 75 to 85%. It is important to position the coating surface of the adhesive layer 120 away from it, and as a result, it is possible to lower the oxygen permeation to the outside.

The experimental oxygen permeability analysis results for this are shown in Table 1 below.

sample 0% RH 75% RH note PP/PVOH(1) + RH exposure 393 cc/m2,day,atm 435 cc/㎡,day,atm PP (60㎛) PVOH(1)/PP + RH exposure 385 cc/m2,day,atm 395 cc/m2,day,atm PP (60㎛) PP/PVOH(2) + RH exposure 97 cc/㎡,day,atm 165 cc/㎡, day, atm PP (60㎛) PVOH(2)/PP + RH exposure 92 cc/m2,day,atm 72 cc/㎡,day,atm PP (60㎛)

Although there is a difference in oxygen permeability depending on the type of polyvinyl alcohol (PVOH), when the distance to which water reaches the PVOH coating layer is close, the hydroxyl group (-OH) is hydrated by water and the oxygen barrier property is lowered, and the oxygen permeability value increases. it can be seen that

1 is a diagram for explaining a position in which a lead film 100 according to the present invention is provided in a cup.
FIG. 2 is a photograph exemplarily showing that the lead film 100 according to the present invention is provided on the flange portion of the cup.
3 is a photograph exemplarily showing the lead film 100 according to the present invention.
4 is a conceptual diagram schematically showing the laminated structure of the lead film 100 according to the present invention.
5 is a photograph exemplarily showing an embossing process on the lead film 100 according to the present invention.

Before describing the present invention in more detail, terms or words used in the present specification and claims should not be limited to their conventional or dictionary meanings, and the concept of terms should be properly explained in order to best describe the invention. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined as Accordingly, the configuration of the embodiments described in this specification is only one preferred example of the present invention, and does not represent all the technical spirit of the present invention, so various equivalents and modifications that can be substituted for them at the time of the present application It should be understood that there may be

Hereinafter, preferred embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily practice the present invention. In addition, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a lid for a liquid food container, and more particularly, to a lid for a liquid food container that can secure excellent heat resistance and adhesion without using aluminum, can be recycled, and can be easily incinerated.

1 is a diagram for explaining a position in which a lead film according to the present invention is provided in a cup, FIG. 2 is a photograph exemplarily showing that a lead film according to the present invention is provided in the flange portion of the cup, FIG. 3 is It is a photograph exemplarily showing the lead film according to the present invention, and FIG. 4 is a conceptual diagram schematically showing the laminated structure of the lead film 100 according to the present invention, and FIG. 5 is an embossing process on the lead film according to the present invention. This is an example picture.

1, the lead film according to the present invention contains liquid food and beverages such as coffee or juice and is adhered to the upper portion of the flange 11 of the container 10, such as a cup made of a material such as plastic. It is used to close the top opening 12 of the container 10 .

That is, referring to FIG. 1 , the upper opening 12 of the disposable plastic container 10 that is injection or extrusion molded with a material such as polypropylene (PP) and contains instant drinks such as coffee or juice is the container 10 . The lead film is sealed by hot pressing (HP) on the upper surface of the flange part 11 of the This completes the packaging.

As such, when ingesting the liquid beverage contained in the container 10, a straw or the like is inserted into the through hole formed in the lead cover (C) and the straw passes through the lead film to ingest a drink using the straw, or the lead cover (C). ) and lead film are removed and drink is consumed directly.

On the other hand, conventionally, as such a lead film, a lead film in which aluminum is laminated on the lower front surface has been mainly used. Recycling is impossible because it is almost impossible to separate from propylene (PP), and when it is incinerated, polypropylene (PP) and the like must be incinerated at a much higher temperature than can be incinerated.

Therefore, the present inventors have developed a novel lead film that can replace the lead film in which aluminum was used on the front surface as described above.

As shown in FIG. 1 , the lead film 100 according to the present invention is sealed to the upper flange 11 of the cup container 10 by thermocompression bonding (HP).

On the other hand, FIG. 2 is a photograph exemplarily showing that the lead film 100 according to the present invention is provided on the flange portion of the cup container, and FIG. 3 is an exemplary photograph of the lead film 100 according to the present invention.

2 and 3, the lead film according to the present invention does not contain aluminum, and is transparent or translucent.

4 schematically shows an example of two laminated structures of the lead film 100 according to the present invention.

First, as shown in (a) of FIG. 4, the lead film for a liquid food container according to the present invention includes an oxygen barrier layer 110; and an adhesive layer 120 provided under the oxygen barrier layer 110 and adhered to the flange portion 11 of the cup container 10; and the oxygen barrier layer 110 is polypropylene ( PP) may be coated with polyvinyl alcohol (PVOH).

On the other hand, the container 10 sealed by the lead film according to the present invention is made of a polyolefin material such as polypropylene (PP), and has an open part 12 at the upper end and a flange part 11 is provided at the rim. has been

Meanwhile, the adhesive layer 120 may be made of the same material as the flange portion of the cup container.

That is, for example, when the flange portion of the cup container is made of a polypropylene (PP) material, the adhesive layer 120 may also be formed of a polypropylene (PP) material.

On the other hand, when it is difficult to use a straw, such as yoghurt to be swallowed by a liquid drink, in order to lower the adhesiveness between the adhesive layer 120 and the flange portion of the cup container, the same material as the material of the cup container and a different material that is different from that of the cup container It is also possible to configure the adhesive layer 120 with a mixed material.

On the other hand, the oxygen barrier layer 110 included in the lead film for a liquid food container according to the present invention may be polypropylene (PP) coated with polyvinyl alcohol (PVOH) in the direction in contact with the adhesive layer 120 . have.

That is, in order to form the oxygen barrier layer 110 in this way, first, an acrylic or urethane-based primer layer is applied on one surface of a polypropylene (PP) film, and polyvinyl alcohol (PVOH) is applied on the primer layer thus applied. Coating completes the oxygen barrier layer.

On the other hand, when the lead film 100 according to the present invention is formed with two layers as shown in FIG. .

That is, the -OH group present in the PVOH layer provided in the oxygen barrier layer 110 reacts with moisture to lower the oxygen permeation barrier property. In the case of a layer configuration, the PVOH-coated surface of the oxygen barrier layer 110 is laminated so as to be adjacent to the adhesive layer 120 in order to prevent the PVOH layer from reacting with moisture in the atmosphere to decrease the oxygen permeability barrier.

On the other hand, in the case of forming the lead film 100 according to the present invention in three layers as shown in FIG. 4(b), the PVOH-coated surface of the oxygen barrier layer 110 is laminated so that the adhesive layer 120 is adjacent to it. .

Meanwhile, the lid for a liquid food container according to the present invention may further include a surface layer 130 provided on the oxygen barrier layer 110 to reinforce the heat resistance of the lid.

Such a surface layer 130 may be formed of the same material as the flange portion of the cup container (eg, PP), or may be formed of polyethylene terephthalate (PET) or nylon.

That is, when forming the surface layer 130 in this way, when the lead film 100 is heat-sealed to the flange portion 11 of the cup container 10 by hot press, the lead film 100 is caused by the high temperature heat of the hot press. It is possible to prevent the flatness of the lead film 100 from being deteriorated due to the damaged or wrinkled curls.

On the other hand, when the lead film 100 is composed of three layers as shown in FIG. 4B , it is possible to arrange the PVOH coating layer provided in the oxygen barrier layer 110 in a direction in contact with the surface layer 130 . do.

That is, in the case of configuring the lead film 100 in three layers as described above, the PVOH coating layer provided on the oxygen barrier layer 110 is arranged in a direction in contact with the surface layer 130 , thereby providing the oxygen barrier layer 110 . While preventing the provided PVOH coating layer from reacting with moisture in the air, it is possible to effectively delay the moisture of the liquid beverage contained in the cup container 10 from passing through the adhesive layer 120 to reach the PVOH coating layer. .

On the other hand, in general, polyvinyl alcohol (PVOH) has a characteristic that the oxygen barrier effect decreases as the external humidity increases.

Of course, there is a difference in degree depending on the type of PVOH, but there is a dependence on humidity. .

As the crosslinking agent, various compounds having a carboxyl group (-COOH) (citric acid, carboxylic acid, succinic acid, tartaric acid, glutaraldehyde, glyoxal, dialdehyde, lactate, silane, etc.) may be used in an appropriate amount. Although the oxygen permeability increases depending on the degree of crosslinking, the oxygen permeability of the PP film coated with the crosslinked polyvinyl alcohol (PVOH) solution is less than 200cc/m2, day, atm at 75% relative humidity based on a 60㎛ thickness. It was confirmed as shown in Table 2 below that the oxygen permeability of the laminated leads was obtained to be less than 1cc/m2,day,atm, so that it is possible to exclude the aluminum foil from the composition of the lead material.

sample RH 0% RH 55% RH 65% RH 75% note PVOH coated PP(1) 1.0 3.819 36.01 169.5 PP (60㎛) PVOH coated PP(2) 0.8 6.198 37.65 205.1 PP (60㎛) PVOH coated PP(3) 3.0 0.874 3.35 13.4 PP (25㎛) PVOH coated PP(4) 0.1 0.216 0.75 7.52 PP (60㎛) PP/PVOH coating PP(1)/PP 0.763 0.986 1.010 1.118 PP/PVOH coating PP(2)/PP 0.324 0.296 0.550 0.764 PP/PVOH coating PP(3)/PP 0.497 0.469 0.563 0.583

<Oxygen permeability by sample (cc/m2, day, atm)>

On the other hand, it is possible to form the lead film 100 according to the present invention to have a laminate thickness of approximately the same ratio as described in Tables 3 and 4 below.

division surface layer 130 Oxygen barrier layer (110) adhesive layer 120 Example 1 60 60 60 Example 2 60 30 60 Example 3 60 25 60 Example 4 30 30 30 Example 5 30 25 30

(Unit: μm)

division Oxygen barrier layer (110) adhesive layer 120 Example 1 60 60 Example 2 40 40 Example 3 25 60 Example 4 30 30 Example 5 25 30

(Unit: μm)

On the other hand, Figure 5 is an exemplary photograph showing the embossing process on the lead film 100 according to the present invention.

That is, as shown in Fig. 5, the lead film 100 according to the present invention can be embossed on the surface so that a plurality of protrusions are formed on either one or both surfaces of the upper and lower surfaces.

That is, when embossing the surface of the lead film 100 in this way, when a plurality of lead films 100 are stacked and one lead film to be sealed in the cup container is grabbed and lifted by a suction device, under There is an advantage in that the laminated lead film can be prevented from coming up together by a momentary vacuum.

On the other hand, if embossing that gives the physical shape of the surface of the single lead film is not desired, silicone and acrylic polymer compounds that give heat resistance, slip properties and releasability to the surface may be coated in order to separate and supply one sheet smoothly. have.

Acrylic polymer is a thermosetting material with adhesion to the film, and the reactive silicone polymer is oriented to the surface due to the difference in surface tension during the aging process after coating the film, giving the coated film lubricity and heat resistance.

On the other hand, in the lead film according to the present invention, it is also possible to mix thermally conductive metallic particles only at positions corresponding to the flange portion of the cup container.

That is, FIG. 7 is a plan view of the lead film of this embodiment. Referring to FIG. 7 , the central portion 100C of the lead film corresponding to the open portion of the cup constitutes the lead film by the lamination structure as described above. However, it is possible to mix thermally conductive metal particles in the edge portion 100T of the lead film corresponding to the flange portion of the cup container.

That is, when the thermally conductive material is evenly mixed in the edge portion 100T as described above, when the lead film is thermally bonded to the cup flange portion by hot press, it is transferred to the portion corresponding to the flange portion by the high temperature of the hot press. After the press process, the high-temperature heat can easily escape to the outside, and accordingly, the heat is transferred to the central part of the lead film to effectively prevent the film from curling, and at the same time, It also has the advantage of improving efficiency.

On the other hand, in the case of evenly mixing the thermally conductive metal particles or locating the aluminum foil on the edge portion 100T as described above, as shown in FIG. 7 , an incision line ( It is possible for C1, C2, C3, C4) to be formed.

On the other hand, an edge part removal groove (CC) is formed at one end of the handle part (H) formed to be removable by holding the lead film by hand, and the edge part removal along with the cut lines (C1, C2, C3, C4). It is possible to easily remove the edge portion 100T of the lead film by using the groove CC.

Claims (10)

Oxygen blocking layer 110; and
An adhesive layer 120 provided under the oxygen barrier layer 110 and adhered to the flange portion 11 of the cup container 10; ) as a lid film 100 for a liquid food container that seals,
The oxygen blocking layer 110 is
A lid film for liquid food containers, characterized in that polypropylene (PP) is coated with polyvinyl alcohol (PVOH). The method according to claim 1,
The adhesive layer 120 is
A lead film for liquid food containers, characterized in that it is made of the same material as the flange portion of the cup container. The method according to claim 1,
The adhesive layer 120 is
A lead film for a liquid food container, characterized in that it is a mixed material of the same material as that of the cup container and a heterogeneous material that is different from that of the cup container in order to lower the adhesion to the flange part of the cup container. The method according to claim 1,
The oxygen blocking layer 110 is
A lid film for a liquid food container, characterized in that polyvinyl alcohol (PVOH) is coated on polypropylene (PP) in a direction in contact with the adhesive layer (120). The method according to claim 1,
The lead film for liquid food container, characterized in that it further comprises; a surface layer (130) provided on the oxygen barrier layer (110) to reinforce the heat resistance of the lead film. 6. The method of claim 5,
The surface layer 130 is a lead film for a liquid food container, characterized in that the same material as the material of the flange portion of the cup container, polyethylene terephthalate (PET) or nylon material. 6. The method of claim 5,
The oxygen blocking layer 110 is
A lid film for a liquid food container, characterized in that polyvinyl alcohol (PVOH) is coated on polypropylene (PP) in a direction in contact with the adhesive layer (130). The method according to claim 1,
The oxygen permeability value of the oxygen barrier layer 110 is a coating film thickness of polyvinyl alcohol (PVOH) or crosslinked to have a value of 200cc/m2, day, atm or less at RH75%. When laminated with a multilayer material, the oxygen permeability A lead film for liquid food containers that obtains a value of less than 1cc/m2,day,atm and provides oxygen barrier properties that can replace aluminum. When the lid is thermally bonded to the cup container, in the process of transferring heat and pressure to the hot press of the thermal bonding machine, the surface layer 130 and the oxygen barrier layer 110 composed of two layers are deformed by heat or the supply of one lead A lid film for liquid food containers, characterized in that the silicone-acrylic compound is entirely or partially coated on the surface of the film to facilitate separation. A lead film for liquid food container, characterized in that it is embossed on the surface of the lead film to facilitate separation when supplying one lead, and is produced so that the protrusion height by embossing is 50 to 150 μm.

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