WO2020138643A1 - Packaging container including lid film, and manufacturing method of same - Google Patents

Abstract

The present invention relates to a packaging container including a lid film, and a manufacturing method of same. The packaging container according to the present invention includes a polyethylene terephthalate resin foam sheet having densely packed cells having an average cell size of 100 to 500 μm, and thus the surface roughness of the foam sheet can be reduced. Therefore, the adhesiveness and airtightness between a molded body and a lid film can be enhanced even after manufacturing the molded body.

Description

Packaging container containing lead film and manufacturing method thereof

The present invention relates to a packaging container comprising a lead film and a method for manufacturing the same.

Products used in ordinary food packaging containers are divided into foamed and non-foamed types. The foamed food packaging container is a product that is extruded by mixing polystyrene with a foam gas, which has an advantage of maintaining shape, insulation, and price competitiveness because it can maintain a relatively thick thickness. On the other hand, such foamed foam has the disadvantage that harmful substances are detected at high temperatures.

In the case of a non-foaming food packaging device, a product made of heat stable polypropylene in a film form is used. On the other hand, such a non-foamed food packaging container has the advantage of low form change rate at high temperature and no harmful substances detected. However, there are disadvantages of high price and poor insulation.

On the other hand, in modern society, as life becomes more convenient, use of disposable products increases, and demand for delivery food and convenience food products is gradually increasing due to the increase of single-person households. Accordingly, the demand for food packaging containers is also increasing, and consumer needs for new container materials that are safe from harmful substances and are provided with functions according to their use are increasing.

In this regard, food packaging container related companies are researching and developing food packaging containers with all of convenience, safety, eco-friendly performance, and price competitiveness, and the applicant is a heat-resistant material having excellent heat resistance and strength, a manufacturing method thereof, and a packaging including the same A container (Korean Patent No. 10-1667999) and a resin foam having excellent cold resistance, and a packaging container including the same (Korean Patent No. 10-1826785) have been developed. The packaging container is manufactured by using a polyester resin as a resin foam, which is eco-friendly, lightweight, and at the same time can realize high strength and heat resistance, and has excellent durability in accordance with temperature changes.

However, when using an olefin-based lead film that is mainly used in the past, the food container has a disadvantage of insufficient adhesion. Therefore, it is necessary to develop a lead film having excellent adhesion to a polyester foam.

The present invention is to provide a packaging container comprising a lead film and a method of manufacturing the same.

The present invention,

A molded body of a container structure comprising a polyethylene terephthalate resin foam sheet having an average cell size of 100 to 500 μm, and satisfying Equation 1 below;

A flange extending outward along an outer periphery of the opening of the molded body; And

As a packaging container comprising a lead film attached to the flange,

The foamed sheet has a surface roughness (center average roughness: Ra) of 3 or less,

It provides a packaging container characterized in that the adhesion between the molded body and the lead film is 500 to 1,500 gf based on KS M 3725:

[Equation 1]

0.01 ≤ H/D ≤ 2;

In Equation 1,

H represents the depth of the receiving portion in the molded body including the receiving portion and the opening, 1 cm ≤ H ≤ 10 cm,

D represents the diameter of the opening in the molded body, and the unit is cm.

In addition, the present invention,

Placing the foam sheet between the female mold and the male mold of the molding apparatus;

Pressing the female mold and the male mold to form a molded body into a concave shape with an upper opening; And

And attaching a lead film to the opening of the molded body,

The forming step is a method of manufacturing a packaging container characterized in that the sheet is subjected to heat so that the surface temperature is 140 to 160°C, and the molded body is molded by setting the surface temperature of the female mold and the male mold to 60 to 200°C. to provide.

The packaging container according to the present invention includes a polyethylene terephthalate resin foam sheet having a compact cell size with an average cell size of 100 to 500 μm, so that the surface roughness of the foam sheet can be reduced. It is possible to improve the adhesion of the lead film. Specifically, the adhesive strength between the molded body and the lead film is 500 to 1,500 gf based on KS M 3725, which can provide excellent adhesion between the molded body and the lead film. Accordingly, airtightness through the lead film may be improved.

1 is a cross-sectional view of a molded body according to the present invention.

2 is a view sequentially showing a method of manufacturing a molded body according to the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In the present invention, terms such as "comprises" or "have" are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Therefore, the configuration illustrated in the embodiments described in this specification is only one of the most preferred embodiments of the present invention and does not represent all of the technical spirit of the present invention, and various equivalents that can replace them at the time of this application And variations.

The present invention relates to a method for manufacturing a packaging container and a molded body including a lead film. In particular, the packaging container according to the present invention includes a polyethylene terephthalate resin foam sheet having a compact cell size with an average cell size of 100 to 500 μm, so that the surface roughness of the foam sheet can be reduced, so that the molded body can be produced even after production of the molded body. And the adhesion of the lead film. Specifically, the adhesive force between the molded body and the lead film is 500 to 1,500 gf, and thus excellent adhesion between the molded body and the lead film can be provided. Accordingly, airtightness through the lead film may be improved. In addition, by using a polyethylene terephthalate resin, it is environmentally friendly and can be easily reused.

1 is a cross-sectional view of a molded body according to the present invention, and FIG. 2 is a view sequentially showing a method of manufacturing the molded body according to the present invention. Hereinafter, a molded body according to the present invention will be described in detail with reference to FIGS. 1 and 2.

The present invention includes a polyethylene terephthalate resin foam sheet having an average cell size of 100 to 500 μm, and a molded body 10 having a container structure satisfying Equation 1 below; A flange 13 extending outward along the outer periphery of the opening of the molded body 10; And a lead film attached to the flange 13, wherein the foamed sheet has a surface roughness (centre average roughness: Ra) of 3 or less, and the adhesion between the molded body 10 and the lead film is KS M 3725. It provides a packaging container characterized by 500 to 1,500 gf as a standard:

[Equation 1]

0.01 ≤ H/D ≤ 2;

In Equation 1,

H represents the depth of the receiving portion in the molded body including the receiving portion and the opening, 1 cm ≤ H ≤ 10 cm,

D represents the diameter of the opening in the molded body, and the unit is cm.

The molded body 10 has a shape of a cup or a bowl, and is provided with an accommodation space for accommodating instant food. In addition, the molded body includes a flange 13 extending outward along the outer periphery of the opening, and the lead film may be attached to the flange 13. Typically, the lead film is attached to the top of the molded body containing the instant food, and serves to prevent the instant food from being exposed to the outside.

The lead film of the present invention may have an adhesive strength between the molded body and 500 to 1,500 gf based on KS M 3725, and thus has an advantage of providing excellent adhesion between the molded body and the lead film. Accordingly, the packaging container of the present invention can improve the airtightness through the lead film. For example, the adhesive force between the molded body and the lead film is 500 to 1,200 gf, 500 to 1,000 gf, 500 to 800 gf, 500 to 600 gf, 600 to 1,500 gf, 800 to 1,500 gf, 1,000 to 1,500 gf, or 1,200 to It can be 1,500 gf.

The lead film may include an aluminum foil layer, an adhesive layer applied to one surface of the aluminum foil layer, and a printing layer applied to the other surface of the aluminum foil layer. In particular, the lead film may be fused to the flange of the molded body through the packaging process of the packaging container. Specifically, when the aluminum layer is instantaneously heated, the adhesive layer of the heated part is melted and fused to the flange of the molded body so that the top of the molded body (flange ).

As an example, the lead film may be composed of 3 to 7 layers, and may include an adhesive layer on an inner front surface in contact with the top of the molded body, and the adhesive layer may include ethyl-methacrylate (ethyl). -methacrylate), polyethylene (polyethylene), polypropylene (polypropylene), and may include one or more of polyethylene terephtalate (polyethylene terephtalate), for example, the adhesive layer may be ethyl-methacrylate (EMA) .

The adhesive layer having the improved adhesive strength as described above can not only be easily heat-sealed to the top of the molded body, but also provides excellent airtightness, etc. when applied to a packaging container by maintaining a certain level of adhesion between the molded body 10 and the lead film. There is an advantage to do.

As one example, the molded body 10 according to the present invention includes a bottom portion 11 and a wall portion 12 with an open top along the circumference of the bottom portion 11, H/ in Equation 1 D values may be 0.01 to 2, 0.01 to 1.5, 0.01 to 1.3, 0.05 to 1.2, 0.1 to 1.1, 0.3 to 1.0, 0.4 to 0.9, 0.5 to 0.8, 0.55 to 0.7, or 0.6 to 0.65. In addition, the H value in Equation 1 may be 1 to 10 cm. As an example, the diameter D of the opening of the molded body 10 may be 10 cm, and the depth H of the receiving portion may be 3 cm.

On the other hand, the molded article 10 according to the present invention includes a polyethylene terephthalate resin foam layer and a polyethylene terephthalate resin layer coated on one or both sides of the foam layer, thereby providing a molded body 10 satisfying the following Equation 2: can do.

[Equation 2]

|T ₂ -T ₁ | ≥ 10℃

In Equation 2,

T ₁ is the temperature of the outer surface of the molded body measured at a temperature of 20° C. and 1 atm, when the molded body contains 100° C. of water, and after 1 minute,

T ₂ is the temperature of the water inside the molded body measured when 1 minute elapsed after containing 1 hour of water at 100 °C in the molded body 10 at 20°C and 1 atm.

The molded body 10 according to the present invention includes a polyethylene terephthalate resin foam sheet having a compact cell size with an average cell size of 100 to 500 μm, thereby indicating excellent thermal barrier properties. Specifically, at room temperature (20° C.) and 1 atmosphere, the temperature of the water inside the molded body 10 at the time when 1 minute has elapsed, while 70% (v/v) of 100° C. water is contained inside the molded body 10 And the temperature difference of the outer surface of the molded body 10 may be 10 ℃ or more. This indicates that the molded article 10 according to the present invention is excellent in heat shielding properties. Specifically, at a time when 1 minute elapses in a state where 70% (v/v) of water at 100° C. is contained in the manufactured molded article 10 (10) It is the temperature difference between the temperature of the water accommodated inside and the outer surface of the molded body 10.

As an example, in the state where 70% (v/v) of water at 100° C. is contained in the molded body 10 according to the present invention, when the external temperature of the molded body 10 is 40° C. after 1 minute, the molded body ( 10) The temperature of water accommodated therein may be 95°C. The molded article 10 according to the present invention maintains a relatively high temperature difference between the temperature of the water accommodated inside the molded body 10 and the outer surface of the molded body 10 under the above conditions, and thus it can be seen that the heat shielding property is excellent. It shows the effect of effectively improving.

On the other hand, the polyethylene terephthalate resin foam sheet of the present invention may include 0.1 to 10% by weight of inorganic particles, the average size of the inorganic particles may be 0.05 to 60 μm. For example, the foam sheet is 0.1 to 8% by weight, 0.1 to 6% by weight, 0.1 to 4% by weight, 0.1 to 2% by weight, 0.1 to 1% by weight, 1 to 10% by weight, 2 to 10% by weight, 4 to 10% by weight, 6 to 10% by weight, or may include 8 to 10% by weight of inorganic particles, the average size of the inorganic particles is 0.05 to 50 μm, 0.05 to 30 μm, 0.05 to 10 μm, 0.05 To 5 μm, 0.05 to 1 μm, 1 to 60 μm, 5 to 60 μm, 20 to 60 μm, or 40 to 60 μm.

The inorganic particles may include one or more of Talc, CaCO ₃ , TiO ₂ , and SiO.

As an example, the polyethylene terephthalate resin foam sheet may include 0.5 to 9% by weight of calcium carbonate (CaCO ₃ ).

Specifically, the calcium carbonate (CaCO ₃ ) is an inorganic particle, and by including the inorganic particle as described above, the surface of the polyethylene terephthalate resin foam layer of the present invention can be uniform and exhibit excellent thermoformability.

The thermal conductivity of the calcium carbonate may be 1.0 to 3.0 kcal/mh ℃. Specifically, the thermal conductivity of calcium carbonate may be 1.2 to 2.5 kcal/mh°C, 1.5 to 2.2 kcal/mh°C, or 1.8 to 2.0 kcal/mh°C. More specifically, the thermal conductivity of calcium carbonate may be 1.5 to 2.5 kcal/mh°C or 1.8 to 2.3 kcal/mh°C. As described above, the foamed sheet containing calcium carbonate has a uniform surface by exhibiting excellent thermal conductivity, and can exhibit excellent thermoformability.

For example, the content of calcium carbonate may be 0.5 to 9% by weight. Specifically, the content of calcium carbonate is 0.5 to 8 wt%, 0.6 to 7 wt%, 0.7 to 6 wt%, 0.8 to 5 wt%, 0.9 to 4 wt%, 1.0 to 3.0 wt%, 2 wt% to 3.5 wt% %. For example, it may be 1.0% by weight or 3% by weight.

In one example, the density of the foam sheet (KS M ISO 845) may be an average of 100 to 500 kg / m ³ . Specifically, the density of the foam sheet is average 100 to 450 kg/m ³ , 100 to 400 kg/m ³ , 100 to 300 kg/m ³ , 100 to 200 kg/m ³ , 150 to 500 kg/m ³ , 200 To 500 kg/m ³ , 300 to 500 kg/m ³ , or 400 to 500 kg/m ³ .

In another example, the foam sheet according to the present invention may have a high temperature elongation at 325% to 375% under conditions of 10 seconds at 200°C. Specifically, the foam sheet may have a high temperature elongation at 200°C for 10 seconds under conditions of 330% to 360%, 345% to 370%, or 335% to 360%. More specifically, the foam sheet may have a high temperature elongation of 345% to 355% at a condition of 200°C for 10 seconds.

By including the polyester and calcium carbonate as described above, the foam sheet according to the present invention can exhibit excellent processability.

Based on specifications of the Agency for Food and Drug Administration and packaging and its raw materials, when measuring dissolution standards, the total elution amount is 30 ppm or less, and antimony germanium, terephthalic acid, isophthalic acid, acetaldehyde materials are not detected, and residual standards are measured. At the time, it is characterized in that volatile substances are not detected.

Specifically, the molded body 10 according to the present invention, as described above, by using an environmentally friendly material, polyester resin, the standard and specification for notification of standards and specifications for packaging of devices and containers issued by the Ministry of Food and Drug Safety Notification No. 2015-7 The substances of concern described in may be adjusted within an allowable range.

By manufacturing a food packaging container using the molded body 10 using such a material, an eco-friendly food container can be provided. As one example, the molded body according to the present invention has a barrier performance and a hydrophilic function. Or it can have a waterproof function, surfactants, hydrophilic agents, heat stabilizers, waterproofing agents, cell size expanders, infrared attenuators, plasticizers, fire retardant chemicals, pigments, elastomers, extrusion aids, antioxidants, antioxidants and UV absorbers It may further include one or more functional additives selected from the group consisting of. Specifically, the resin foam sheet of the present invention may include a thickener, a heat stabilizer and a foaming agent.

The thickener is not particularly limited, but in the present invention, for example, pyromellitic dianhydride (PMDA) may be used.

The heat stabilizer may be an organic or inorganic compound. The organic or inorganic compound may be, for example, phosphoric acid and its organic ester, phosphorous acid and its organic ester. For example, the thermal stabilizer is a commercially available material, and may be phosphoric acid, alkyl phosphate or aryl phosphate. Specifically, in the present invention, the thermal stabilizer may be triphenyl phosphate, but is not limited thereto, and can be used without limitation within a typical range as long as it can improve the thermal stability of the resin foam sheet.

Examples of the foaming agent include N ₂ , CO ₂ , Freon, butane, pentane, neopentane, hexane, isohexane, heptane, isoheptane, methyl chloride, or a physical foaming agent or azodicarbonamide compound, P, P'-oxybis(benzenesulfonyl hydrazide) [P,P'-oxy bis (benzene sulfonyl hydrazide)] compound, N,N'-dinitrosopentamethylenetetraamine (N,N'-dinitroso pentamethylene There are chemical blowing agents such as tetramine)-based compounds, and specifically, CO ₂ may be used in the present invention.

In addition, the present invention provides a method for manufacturing a molded body.

2 is a view sequentially showing a method of manufacturing a molded body according to the present invention. Referring to Figure 2, the present invention, the step of placing the foam sheet between the female mold and the male mold of the molding apparatus; Pressing the female mold and the male mold to form a molded body into a concave shape with an upper opening; And attaching a lead film to the opening of the molded body, wherein the forming step applies heat so that the sheet surface temperature is 140 to 160°C, and the surface temperature of the female mold and the male mold is 60 to 200°C. It provides a method for manufacturing a packaging container, characterized in that to mold the molded body by setting.

On the other hand, the foam sheet, comprising the steps of preparing a foam sheet by cooling after extrusion foaming a resin mixture comprising a polyethylene terephthalate resin and inorganic particles, the step of cooling after the extrusion foaming temperature of -10 to 20 ℃ It can be characterized by performing in the range. For example, the foam sheet can be prepared by extrusion foaming a polyester resin mixture. The extruded foam is melted by heating the resin, and by continuously extruding and foaming the resin melt, the process steps can be simplified, mass production is possible, cracks between beads when foaming beads, and granular destruction phenomenon, etc. Can be prevented. The step of cooling after the extrusion foaming may be to cool the inner side of the foam sheet with a mandrel made of metal of the foaming device, and the outer side of the foaming sheet with cooling air of the foaming device, wherein the cooling is -10 to 20°C. It may be performed in the temperature range. For example, the cooling may be performed at -10 to 15°C, -10 to 10°C, -10 to 5°C, 5 to 20°C, or 15 to 20°C.

The foam sheet may include 0.1 to 10% by weight of inorganic particles, the average size of the inorganic particles may be 0.05 to 60 μm. For example, the foam sheet is 0.1 to 8% by weight, 0.1 to 6% by weight, 0.1 to 4% by weight, 0.1 to 2% by weight, 0.1 to 1% by weight, 1 to 10% by weight, 2 to 10% by weight, 4 to 10% by weight, 6 to 10% by weight, or may include 8 to 10% by weight of inorganic particles, the average size of the inorganic particles is 0.05 to 50 μm, 0.05 to 30 μm, 0.05 to 10 μm, 0.05 To 5 μm, 0.05 to 1 μm, 1 to 60 μm, 5 to 60 μm, 20 to 60 μm, or 40 to 60 μm.

The inorganic particles may include one or more of Talc, CaCO ₃ , TiO ₂ , and SiO ₂ .

Next, the step of processing the step of placing the foam sheet 1 between the female mold 21 and the male mold 22 of the molded body forming apparatus 20 and pressing the male mold 22 to press the molded body 10 Provides a molding step.

Specifically, the foam sheet 1 disposed between the female mold 21 and the male mold 22 may be molded into a molded body 10 by thermal molding. Examples of the thermoforming include vacuum forming, pressure forming or vacuum pressure forming using a combination of vacuum forming and pressure forming, using a male mold (plug) or using the male mold 22, followed by vacuum and/or pressure forming. Can be thermoformed.

Referring to FIG. 2, FIG. 2(a) shows an arrangement step of placing the foam sheet 1 between the female mold 21 and the male mold 22 of the molding apparatus before molding the foam sheet 1. Shows. FIG. 2(b) is a view showing a stretching process and a thermal process. As shown in FIG. 2(b), the male mold 22 is lowered to stretch the foam sheet 1, and the female mold 21 is It is molded into the shape of the cavity of the female mold 21 by vacuum suction, and heat is applied. Fig. 2(c) shows a molded body which is a final molded product by shaping the foam sheet 1 being molded into the shape of the male mold 22 by pressurization of the male mold 22 and compressed air from the female mold 21. 10) is molded. Next, the molded body 10 can be taken out by raising the male mold 22 after cooling.

In addition, in the forming step, heat may be applied so that the surface temperature of the sheet is 140 to 160°C, and the molded body may be molded by setting the surface temperatures of the female mold 21 and the male mold 22 to 60 to 200°C. .

Meanwhile, in the forming step, the surface of the male mold 22 and the surface temperature of the cavity of the female mold 21 may be different. Preferably, the surface temperature of the male mold 22 may be 250 to 280°C, 255 to 275°C, 260 to 270°C, or 265°C, respectively, and the cavity surface temperature of the female mold is 200 to 250°C, 210 to 240°C , 215 to 235°C, 220 to 230°C, or 225°C.

As an example, the surface temperature of the male mold 22 may be 265°C, the surface temperature of the female mold 21 may be 225°C, and the male mold 22 may be a female mold 22 for 0.5 to 15 seconds. ). In addition, the female mold 21 may have a structure in which a decompression hole 23 for decompressing a cavity that is an internal space is formed on one side.

Next, it may further include the step of cooling the molded body in a temperature range of -10 to 20 ℃. More specifically, the temperature of the cooling step is -10 to 20 ℃, -5 to 18 ℃, -1 to 17 ℃, 1 to 16 ℃, 2 to 15 ℃, 3 to 14 ℃, 4 to 13 ℃, 5 to It may be 12 ℃, 6 to 11 ℃ or 10 ℃. When the hot-formed packaging container is cooled to a temperature in the above range, the crystallinity of the polyester resin foam sheet may be formed in the range of 10 to 35%. When cooling is performed in the above temperature range, the crystallinity of the polyester resin foam sheet is prevented from excessively increasing, so that the molded body in the mold can be easily molded, and a molded body having excellent light weight and heat resistance can be manufactured.

As one example, the crystallinity of the packaging container may be formed in a range of 10 to 35% by cooling the hot-formed packaging container at a reduced temperature of 0.5 to 5°C/min. The temperature reduction conditions may be specifically 0.8 to 4.5°C/min, 1 to 4°C/min, 1.5 to 3.5°C/min, 1.8 to 3.2°C/min, 2 to 3°C/min, or 2.3 to 2.8°C/min. have. When performing the step of cooling under the reduced temperature conditions, the crystallinity of the polyester resin foam sheet is prevented from excessively increasing, so that the molded body in the mold can be easily molded, and a molded body excellent in light weight and heat resistance can be manufactured.

Hereinafter, the present invention will be described in more detail by examples and experimental examples.

However, the following examples and experimental examples are merely illustrative of the present invention, and the contents of the present invention are not limited to the following examples and experimental examples.

Preparation Example 1

100 parts by weight of the PET resin was dried at 130°C to remove moisture, and 100 parts by weight of the PET resin from which the moisture was removed from the first extruder, 1 part by weight of pyromellitic dianhydride (PMDA), 0.5 μm calcium carbonate (CaCO ₃ ) 1 The resin melt was prepared by mixing 0.1 part by weight of Irganox (IRG 1010) by weight and heating to 280°C. Then, butane gas was mixed as a blowing agent in the first extruder, and the resin melt was sent to a second extruder and cooled to 220°C. The cooled resin melt passed through a die to form a foam sheet.

At this time, the density of the prepared polyester resin foam sheet was 380 kg/m ³ , and the thickness was 1 mm.

Example 1

The foam sheet prepared in Preparation Example 1 was cooled to a cooling temperature of 10°C (Mandrel, Air), and the foam sheet was manufactured into a rectangular container with H/D (H: depth of the receiving part, D: diameter of the opening) of 0.4. Thermoforming. Thereafter, the EMA adhesive layer was sealed at 120°C with a lead film laminated with 20 μm.

On the other hand, when molding the molded body, the surface temperature of the male mold was 40°C, and the surface temperature of the female mold was 80°C.

Example 2

When the foam sheet was manufactured, the foam sheet and the molded body were prepared in the same manner as in Example 1, except that the cooling temperature was 15°C, and then sealed with a lead film.

Example 3

A molded body was manufactured in the same manner as in Example 1, except that the H/D value was 0.5.

Example 4

An aluminum foil layer commonly used as a lead film for the packaging container was used, and an ethyl-methacrylate (EMA) adhesive was applied to one surface of the aluminum foil layer to prepare a lead film for the packaging container.

Comparative Example 1

A foam and a molded body were prepared in the same manner as in Example 1, except that ethylene-vinyl acetate (EVA) was applied to the adhesive layer of the lead film, and the lead film was sealed.

Comparative Example 2

When manufacturing a foam sheet, a foam sheet and a molded body were prepared in the same manner as in Example 1, except that the cooling temperature was 30°C, and then sealed with a lead film.

Experimental Example 1: Lead adhesion measurement

Prepare a PET foam sheet and a lead film (PE hot melt 60 μm) as 25×60 mm and seal with a 2 kgf pressure at a temperature of 150°C in a hot press for lead adhesion, then perform a tensile tester based on the KS M 3725 standard. The peel strength was measured using a tensile speed of 200 mm/min.

Experimental Example 2: Centerline surface roughness measurement

The surface roughness value of the centerline was measured according to KS B 0161.

In Examples and Comparative Examples, the measurement results according to the sheet type and molding conditions of the molded body are shown in Table 1 below. The unit of adhesion is gf.

Referring to Table 1, when manufacturing a foamed sheet having a cooling temperature of 20° C. or less, it was found that the surface roughness was 3 or less, and at this time, the adhesive strength with the lead applied with the EMA adhesive layer was 700 gf or more, indicating excellent adhesion. .

When the cooling temperature was 30°C or higher, it was found that the surface roughness was 7 and the surface was rough. When the EVA adhesive layer was used, the adhesive strength was 450 gf, indicating a low adhesive strength.

The packaging container according to the present invention includes a polyethylene terephthalate resin foam sheet having a compact cell size with an average cell size of 100 to 500 μm, so that the surface roughness of the foam sheet can be reduced. It is possible to improve the adhesion of the lead film. Specifically, the adhesive strength between the molded body and the lead film is 500 to 1,500 gf based on KS M 3725, which can provide excellent adhesion between the molded body and the lead film. Accordingly, airtightness through the lead film may be improved.

Claims (10)

1. A molded body of a container structure comprising a polyethylene terephthalate resin foam sheet having an average cell size of 100 to 500 μm, and satisfying Equation 1 below;

   A flange extending outward along an outer periphery of the opening of the molded body; And

   As a packaging container comprising a lead film attached to the flange,

   The foamed sheet has a surface roughness (center average roughness: Ra) of 3 or less,

   Packaging container characterized in that the adhesion between the molded body and the lead film is 500 to 1,500 gf based on KS M 3725:

   [Equation 1]

   0.01 ≤ H/D ≤ 2;

   In Equation 1,

   H represents the depth of the receiving portion in the molded body including the receiving portion and the opening, 1 cm ≤ H ≤ 10 cm,

   D represents the diameter of the opening in the molded body, and the unit is cm.
2. According to claim 1,

   The lead film is a packaging container containing at least one of ethyl-methacrylate, polyethylene, polypropylene, and polyethylene terephthalate.
3. According to claim 1,

   The packaging sheet, characterized in that the average thickness of the foam sheet is in the range of 0.5 to 3 mm.
4. According to claim 1,

   A packaging container characterized by satisfying the following Equation 2:

   [Equation 2]

   |T ₂ -T ₁ | ≥ 10℃

   In Equation 2,

   T ₁ is the temperature of the outer surface of the molded body measured at a temperature of 20° C. and 1 atm, when the molded body contains 100° C. of water, and after 1 minute,

   T ₂ is the temperature of the water inside the molded body measured at a temperature of 20° C. and 1 atm, containing 100° C. of water in the molded body, and when 1 minute has elapsed.
5. According to claim 1,

   The packaging container is a packaging container characterized in that the food packaging container.
6. Placing the foam sheet between the female mold and the male mold of the molding apparatus;

   Pressing the female mold and the male mold to form a molded body into a concave shape with an upper opening; And

   And attaching a lead film to the opening of the molded body,

   The forming step is a method of manufacturing a packaging container, characterized in that heat is applied so that the sheet surface temperature is 140 to 160°C, and the molded body is molded by setting the surface temperature of the female mold and the male mold to 60 to 200°C.
7. The method of claim 6,

   The foam sheet,

   The resin mixture containing the polyethylene terephthalate resin and the inorganic particles is extruded and cooled, and then a step of manufacturing a foamed sheet is provided.

   The step of cooling after the extrusion foaming is a manufacturing method of a packaging container, characterized in that performed in a temperature range of -10 to 20 ℃.
8. The method of claim 7,

   The method for manufacturing a packaging container having an average particle size of 0.05 to 60 μm.
9. The method of claim 6,

   The female mold is a method of manufacturing a packaging container, characterized in that a structure in which a pressure-reducing hole for decompressing an internal space is formed on one side.
10. The method of claim 6,

    The method of manufacturing a packaging container further comprising the step of cooling the molded body in a temperature range of -10 to 20°C.

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