WO2020004744A1 - Molded article including gas barrier layer, packing container including same, and method for preparing molded article - Google Patents

Abstract

The present invention relates to a molded article including a gas barrier layer, a packing container including same, and a method for preparing the molded article. The molded article according to the present invention includes first and second foam sheets on both sides of the gas barrier layer, respectively, so that the permeability of oxygen and moisture can be minimized. When the molded article is used in a food packing container, food spoilage or the like caused by oxygen or moisture are prevented, and thus food can be easily preserved.

Description

Molded body comprising a gas barrier layer, a packaging container including the same and a method of manufacturing the molded body

The present invention relates to a molded article comprising a gas barrier layer, a packaging container including the same, and a manufacturing method of the molded article.

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

In the case of a non-foamable food packaging device, a product made of polypropylene which is thermally stable in the form of a film is used. On the other hand, such a non-foamable food packaging container has the advantage of low form change rate at high temperature, harmful substances are not detected. However, there is a disadvantage that the price is expensive and the heat insulation is not good.

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

In this regard, a lot of efforts have been made in the food packaging container-related companies to manufacture a food packaging container with all the convenience, safety, eco-friendly performance and price competitiveness.

As an example, a technology for an eco-friendly heat-resistant material and a packaging container (Korean Patent No. 10-1778629) including the same has been proposed. Specifically, the registered patent discloses a packaging container having a heat resistant material having a two-layer structure including an ethylene vinyl alcohol (EVOH) gas barrier layer on at least one surface of a polyethylene terephthalate (PET) foam. It is.

However, although the ethylene vinyl alcohol has excellent barrier properties, molding is difficult due to a large melting point difference with polyethylene terephthalate. Specifically, high temperature heat treatment is required to improve the heat resistance of polyethylene terephthalate. In this case, the composition state of the food packaging container is such that the ethylene vinyl alcohol is fused to form a gas barrier layer on the entire area of the food packaging container. There is a problem that becomes poor.

The present invention is to solve the above-mentioned problems, to provide a molded body, a packaging container including the same and a manufacturing method thereof that can prevent damage to the gas barrier layer when forming the container.

The present invention,

The first foam sheet, the gas barrier layer and the second foam sheet is a laminated structure sequentially, a molded body that satisfies the following equation 1,

The first foam sheet and the second foam sheet is a foam of a polyester resin,

The average thickness of the molded body is in the range of 1 to 5 mm,

A molded article is characterized in that the oxygen permeability according to ASTM F 3985 is not more than 20 cc / m ² · day under conditions of 23 ° C .:

[Equation 1]

H / D ≥ 0.01

In Equation 1,

Forming a shaped body of the container structure including the receiving portion and the opening,

H represents the depth of the receptacle and is 1 to 10 cm,

D represents the diameter of the opening.

In addition, the present invention provides a packaging container including the molded body.

Furthermore, the present invention,

Disposing a sheet having a structure in which the first foam sheet, the gas barrier layer and the second foam sheet are sequentially stacked between the female mold and the male mold of the molding apparatus; And

And pressing the male mold to mold the molded body.

The first foam sheet and the second foam sheet provides a method for producing a molded body, characterized in that the foam of the polyester resin.

The molded article according to the present invention can minimize oxygen and moisture permeability by including first and second foam sheets on both sides of the gas barrier layer, respectively. In addition, when the molded article is used in a food packaging container, it may be easy to preserve the food by preventing the decay of the food due to oxygen and moisture.

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

2 is a view sequentially showing a method for producing a molded article according to the present invention.

The present invention relates to a molded article comprising a gas barrier layer, a packaging container including the same, and a manufacturing method of the molded article. In particular, the molded article according to the present invention includes the first and second foam sheets on both sides of the gas barrier layer, thereby minimizing oxygen and moisture permeability. In addition, when the molded article is used in a food packaging container, it may be easy to preserve the food by preventing the decay of the food due to oxygen and moisture.

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

The present invention,

The first foam sheet 101, the gas barrier layer 102 and the second foam sheet (101 ') is a laminated structure sequentially, as a molded body 10 that satisfies the following equation 1,

The first foam sheet 101 and the second foam sheet 101 'is a foam of polyester resin,

The average thickness of the molded body 10 is in the range of 1 mm to 5 mm,

A molded article is characterized in that the oxygen permeability according to ASTM F 3985 is not more than 20 cc / m ² · day under conditions of 23 ° C .:

[Equation 1]

H / D ≥ 0.01

In Equation 1,

Forming a shaped body of the container structure including the receiving portion and the opening,

H represents the depth of the receptacle and is 1 cm to 10 cm,

D represents the diameter of the opening.

Specifically, the molded article according to the present invention may have an oxygen permeability of 0.1 to 20 cc / m ² · day measured according to ASTM D3985. More specifically, in the case of measuring the oxygen permeability for 30 minutes at (23 ± 1) ° C. of the specimens (width × length × height 40mm × 40mm × 3mm) of the manufactured molded article, the oxygen permeability of the molded article was 0.1 20 cc / m ² · day, 0.1 to 15 cc / m ² · day, 0.1 to 13 cc / m ² · day, 0.1 to 10 cc / m ² · day, 0.1 to 7 cc / m ² · day, 0.1 to 5 cc / m ² · day, or 0.1 to 3 cc / m ² · day.

As described above, the first and second foam sheets 101 and 101 'of the polyester resin are formed in the cross-sectional outer layers of the molded body 10, respectively, and the first and second foam sheets 101 and 101' are formed. By forming the gas barrier layer 102 between), it is possible to satisfy the above oxygen permeability. That is, the molded body 10 according to the present invention has an oxygen permeability within the above range, and has an advantage of excellent oxygen shielding performance to extend the shelf life of food.

Specifically, the molded body 10 according to the present invention may form the first and second foam sheets 101 and 101 'on both sides of the gas barrier layer 102 to control oxygen permeability within the above range. .

In addition, the water vapor transmission rate according to ASTM F 1249 is characterized in that less than 50 g / m ² · day under 37 ℃, 100% relative humidity conditions. For example, the water vapor transmission rate is 0.1 to 50 g / m ² · day, 0.1 to 40 g / m ² · day, 0.1 to 30 g / m ² · day, 0.1 to 20 g / m ² · day, 0.1 to 10 g / m ² · day, 0.1 to 7 g / m ² · day, 0.1 to 5 g / m ² · day or 0.1 to 3 g / m ² · day. The molded body 10 according to the present invention may have a water vapor permeability, and thus may be widely used in a product requiring gas barrier properties. For example, when used as a food packaging container, since it is possible to prevent the food from reacting with water vapor to rot, it may be easy to store the food.

The polyester resin may include repeating units derived from an acid component and a diol component. Specifically, the polyester resin may be at least one selected from the group consisting of aromatic and aliphatic polyester resins synthesized from a dicarboxylic acid component and a glycol component or hydroxycarboxylic acid.

The polyester resin may be, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polylactic acid (PLA), polyglycolic acid (PGA) At least one selected from the group consisting of polyethylene adipate (PEA), polyhydroxyalkanoate (PHA), polytrimethylene terephthalate (PTT) and polyethylene naphthalate (PEN) have. For example, polyethylene terephthalate (PET) may be used in the present invention.

In addition, the gas barrier layer 102 may include one or more of ethylene vinyl alcohol (EVOH), polyvinylidene chloride (PVDC), and polyethylene terephthalate (PET). have.

Specifically, the barrier layer 102 may be formed using ethylene vinyl alcohol. In this case, the gas generated from the food inside the packaging can be discharged out, and at the same time the oxygen supply from the outside can be blocked.

The molded body 10 according to the present invention has a multilayer structure, and the average thickness of the multilayer structure forming the molded body 10 may range from 1 mm to 5 mm.

For example, the molded body 10 may have a three-layer structure. In this case, the total thickness of the three-layer structure may be an average of 1.2 to 4 mm, 1.5 to 3.5 mm, 1.8 to 3 mm, or 2 mm. In addition, the average thickness of the gas barrier layer 102 may be 0.01 to 2 mm, 0.05 to 2 mm, 0.1 to 1.9 mm, 0.2 to 1.85 mm, 0.3 to 1.8 mm, 0.5 to 1.6 mm, 0.7 to 1.4 mm , 0.9 to 1.2 mm, or 1 mm.

In addition, the average thickness of the first foam sheet 101 and the second foam sheet 101 'may be 0.5 to 1.5 mm, respectively, 0.6 to 1.3 mm, 0.7 to 1.2 mm, 0.8 to 1.0 mm, 0.9 to 0.95 mm Can be. The molded body 10 of the present invention is composed of the foam sheet (101, 101 ') and the gas barrier layer 102 having a thickness in the above range, thereby satisfying the above-described oxygen permeability and water vapor permeability, and at the same time compressive strength While improving, it is possible to satisfy light weight and the like at the same time.

In one example, the melting point (T _m ) of the first and second foam sheets (101, 101 ') may be an average of 240 to 260 ℃. Specifically, the average melting points of the first and second foam sheets 101 and 101 'may be 242 ° C to 257 ° C, 245 ° C to 255 ° C, 247 ° C to 253 ° C, or 248 ° C to 251 ° C. For example, the melting points of the first and second foam sheets 101 and 101 'including the polyethylene terephthalate resin may be 248 ° C to 251 ° C on average.

In addition, the melting point (T _m ) of the gas barrier layer 102 may be an average of 150 ℃ to 190 ℃. Specifically, the melting point of the gas barrier layer 102 may be an average of 150 ℃ to 190 ℃, 155 ℃ to 185 ℃, 160 ℃ to 180 ℃, 165 ℃ to 175 ℃ or 169 ℃ to 171 ℃. For example, the melting point of the gas barrier layer made of ethylene vinyl alcohol may be 170 ± 0.5 ° C. on average.

On the other hand, polyethylene terephthalate and ethylene vinyl alcohol has a large melting point difference, and when the two-layer structure (foam sheet / gas barrier layer) molded body is formed, ethylene vinyl alcohol is peeled or melted, so that the barrier layer 102 is applied to the entire area of the molded body. Although there was a problem such that it cannot be formed evenly, the gas barrier layer 102 is melted away by laminating the foam sheets 101 and 101 'on both sides of the gas barrier layer 102, or the foam sheets 101 and 101 are laminated. Problems such as peeling off from ') can be solved.

As an example, the molded body 10 according to the present invention includes a bottom portion 11 and a wall portion 12 having an open top along a circumference of the bottom portion 11, and in the equation (1), H / The D value may be 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, in Equation 1, the H value may be 1 to 10 cm. For example, the diameter of the opening of the molded body 10 may be 10 cm, the depth of the receiving portion may be 3 cm. In addition, the molded body 10 according to the present invention may have a container shape, and may have a cylindrical container shape or a rectangular container shape.

Meanwhile, the molded body 10 according to the present invention forms the first and second foam sheets 101 and 101 'on both surfaces of the gas barrier layer 102, thereby satisfying the following equation (2). Can provide:

[Equation 2]

T ₂ -T ₁ | ≥ 10 ℃

In Equation 2,

T ₁ is the outer surface temperature of the molded body measured when 1 minute has elapsed by containing 100 ° C water in the molded body at 20 ° C and 1 atm conditions,

T ₂ is the temperature of the water inside the molded body measured when 1 minute has elapsed after 100 minutes of water is contained in the molded body at 20 ° C. and 1 atm conditions.

The molded article 10 according to the present invention includes the first and second foam sheets 101 and 101 ', indicating excellent thermal barrier properties. Specifically, at room temperature (20 ° C.) and 1 atm, the temperature difference between the water temperature inside the molded body and the outer surface of the molded body is 1 minute after 100 minutes of water at 100 ° C. (v / v) is contained in the molded body. May be greater than or equal to 10 ° C. This indicates that the molded body 10 according to the present invention has excellent thermal barrier properties. Specifically, when the molded product 10 has passed 70 minutes (v / v) of water at 100 ° C. in one minute, the molded body 10 is formed. It is the temperature difference between the temperature of the water contained therein and the outer surface of the molded body 10.

As an example, in the state in which the molded body 10 according to the present invention contains 70% (v / v) of water at 100 ° C., when the external temperature of the molded body is 40 ° C. at 1 minute, the molded body 10 is inside. The temperature of the water accommodated in may be 95 ° C. The molded body 10 according to the present invention can be seen that the thermal barrier property is excellent by maintaining 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, thereby keeping food warm The effect is to effectively improve.

Meanwhile, the first and second foam sheets 101 and 101 ′ of the present invention may each include 0.5 to 9 wt% of calcium carbonate (CaCO ₃ ).

Specifically, the calcium carbonate (CaCO ₃ ) is an inorganic particle, by including the inorganic particles as described above, the first and second foam sheets (101, 101 ') of the present invention is uniform sheet surface and excellent thermoformability Can be represented.

The thermal conductivity of the calcium carbonate may be 1.0 kcal / mh ℃ to 3.0 kcal / mh ℃. Specifically, the thermal conductivity of calcium carbonate may be 1.2 kcal / mh ° C. to 2.5 kcal / mh ° C., 1.5 kcal / mh ° C. to 2.2 kcal / mh ° C. or 1.8 kcal / mh ° C. to 2.0 kcal / mh ° C. More specifically, the thermal conductivity of calcium carbonate may be 1.5 kcal / mh ℃ to 2.5 kcal / mh ℃ or 1.8 kcal / mh ℃ to 2.3 kcal / mh ℃. As described above, the first and second foam sheets 101 and 101 'including calcium carbonate exhibit excellent thermal conductivity and thus have a uniform surface, and may exhibit excellent thermoformability.

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

In one example, the density of the foam sheets 101 and 101 '(KS M ISO 845) may be on average 300 to 700 kg / m ³ . Specifically, the density of the foam sheet (101, 101 ') is an average of 325 to 650 kg / m ³ , 350 to 600 kg / m ³ , 375 to 550 kg / m ³ , 400 to 500 kg / m ³ or 425 to 450 kg / m may be ³ days.

In another example, the foam sheets 101 and 101 'according to the present invention may have a high temperature elongation of 325 to 375% at 200 ° C for 10 seconds. Specifically, the high temperature elongation of the foam sheet (101, 101 ') for 10 seconds at 200 ℃ may be 330 to 360%, 345 to 370% or 335 to 360%. More specifically, the foam sheets 101 and 101 'may have a high temperature elongation of 345 to 355% at 200 ° C for 10 seconds.

By including the polyester and calcium carbonate as described above, the foam sheet (101, 101 ') according to the present invention can exhibit excellent workability.

The first and second foam sheets 101 and 101 'of the molded body 10 according to the present invention are foams of a polyester resin, and the polyester resin of the first and second foam sheets 101 and 101' is polyethylene. It may be a terephthalate (polyethylene terephthalate, PET) resin. By using the PET resin, it may be environmentally friendly and easy to reuse.

Based on the standards of equipment and container packaging and raw materials of the Ministry of Food and Drug Safety and its raw materials, total elution amount is 30ppm or less, antimony germanium, terephthalic acid, isophthalic acid and acetaldehyde are not detected when measuring elution standard. Volatile substances are not detected.

Specifically, the molded article 10 according to the present invention by using the polyester resin which is an environmentally friendly material as described above, the standards and specifications of the Agency and container packaging issued by the Ministry of Food and Drug Safety Republic of Korea Notice No. 2015-7 The substances of concern described in the above can be adjusted within the allowable range.

By manufacturing the food packaging container 10 using the molded body 10 using such a material, it is possible to provide an environmentally friendly food container.

As an example, the molded body 10 according to the present invention may have a barrier performance, a hydrophilization function or a waterproof function, and may include a surfactant, a hydrophilizing agent, a heat stabilizer, a waterproofing agent, a cell size expander, and an infrared attenuation. It may further comprise one or more functional additives selected from the group consisting of plasticizers, fire protection chemicals, pigments, elastomers, extrusion aids, antioxidants, anti-static agents and UV absorbers. 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 for example, pyromellitic dianhydride (PMDA) may be used in the present invention.

The heat stabilizer may be an organic or inorganic phosphorus compound. The organic or inorganic phosphorus 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. If the thermal stabilizer is capable of improving the thermal stability of the resin foam sheet, the thermal stabilizer may be used without limitation.

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

Moreover, this invention provides the manufacturing method of a molded object.

2 is a view sequentially showing a method for producing a molded article according to the present invention. 2, the present invention,

Disposing a sheet 1 having a structure in which the first foam sheet, the gas barrier layer and the second foam sheet are sequentially stacked between the female mold 21 and the male mold 22 of the molding apparatus; And

Pressing the male mold 22 to form the molded body 10,

The first foam sheet and the second foam sheet provides a method for producing a molded body, characterized in that the foam of the polyester resin.

On the other hand, the manufacturing method for the first and second foam sheet is not specifically limited, for example, the first and second foam sheet can be produced by extrusion foaming the polyester resin. Specifically, the type of foaming method includes bead foaming or extrusion foaming. In general, the bead foaming is a method of forming a product by heating a resin bead and primary foaming, aging it for a suitable time, and then filling the mold in a plate or cylindrical shape and then heating it to be fused and molded by secondary foaming. Extrusion foam, on the other hand, heats and melts the resin and continuously extrudes and foams the resin melt, thereby simplifying the process steps, enabling mass production, and cracking and granular fracture between beads during bead foaming. Etc. can be prevented.

Next, the step of processing the sheet 1 having a structure in which the first foam sheet, the gas barrier layer and the second foam sheet are sequentially stacked, the female mold 21 and the male mold 22 of the molded body molding apparatus 20. And forming the molded body 10 by pressing the male mold 22.

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

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

In addition, in the forming step, heat is applied such that the sheet surface temperature is 140 to 160 ° C, and the surface temperature of the female mold 21 and the male mold 22 is set to 60 ° C to 200 ° C to form the molded body 10. It can be molded.

Meanwhile, in the molding step, the surface of the male mold 22 and the cavity surface temperature of the female mold 21 may be different from each other. 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 21 may be 200 to 250 ° C or 210 ° C. To 240 ° C., 215 to 235 ° C., 220 to 230 ° C., or 225 ± 3 ° C.

In one example, the surface temperature of the male mold 22 may be 265 ± 1 ° C., the surface temperature of the female mold 21 may be 225 ° C., and the male mold 22 may be female for 0.5 to 15 seconds. It is preferable to contact the mold 22. In addition, the female mold 21 may have a structure in which a decompression hole 23 for depressurizing a cavity, which is an internal space, is formed at one side.

Accordingly, the container-shaped molded article or the packaging container including the molded article, in which the first foam sheet of the polyester resin, the gas barrier layer, and the second foam sheet of the polyester resin are sequentially laminated by the method of manufacturing the molded article described above. Can be prepared.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples.

However, the following Examples and Experimental Examples are only illustrative of the present invention, and the content of the present invention is not limited to the following Examples and Experimental Examples.

Preparation Example 1.

100 parts by weight of PET resin was dried at 130 ° C. to remove moisture, and 100 parts by weight of the PET resin from which the water was removed in the first extruder, 1 part by weight of pyromellitic dianhydride (PMDA), 1 part by weight of calcium carbonate (CaCO ₃ ), Irganox (IRG 1010) 0.1 part by weight was mixed and heated to 280 ° C. to prepare a resin melt. Then, butane gas was mixed as a blowing agent in the first extruder, and the resin melt was sent to the 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 , the thickness was 1 mm.

Example 1

Laminating a 0.05 mm EVOH film with a barrier layer on one surface of the foam sheet prepared in Preparation Example 1, and laminated on the foam sheet prepared in Preparation Example 1 thereon. And the laminated three-layered sheet was shape | molded to container shape, and the molded object (H: depth D: diameter of opening part) with H / D = 0.3 was manufactured. The opening diameter of the molded body was 10 cm. On the other hand, at the time of shaping | molding of a molded object, the surface temperature of the male mold was 60 degreeC, and the surface temperature of the female mold was 120 degreeC.

Example 2.

A molded article was prepared in the same manner as in Example 1, except that the barrier layer was composed of an EVOH 0.02 mm film and a PET 0.03 mm film 2 layer.

Example 3.

A molded article was prepared in the same manner as in Example 1 except that the value of H / D was 0.5.

Comparative Example 1

Except that the thickness is 2mm, a sheet of a two-layer structure was prepared by laminating a 0.05 mm EVOH film with a barrier layer on one surface of the foam sheet prepared in the same manner as in Preparation Example 1. And the laminated 2-layered sheet was shape | molded to container shape, and the molded object (H: depth D: diameter of an opening part) with H / D = 0.3 was manufactured. The opening diameter of the molded body was 10 cm. In addition, the surface temperature of the male mold was 60 degreeC, and the surface temperature of the female mold was 120 degreeC.

Comparative Example 2

Using a PP multilayer sheet (PP / EVOH / PP), a container having the same structure as in Example 1 of H / D 0.3 was molded, and the temperature of the mold was maintained at 20 ° C. when molding.

In Examples and Comparative Examples, the molded article was manufactured by changing sheet types and molding conditions of the molded article as shown in Table 1 below.

	Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
Layer Layer	PET Form	PET Form	PET Form	PET Form	PP
	EVOH	EVOH + PET	EVOH	EVOH	EVOH
	PET Form	PET Form	PET Form		PP
Thickness of gas barrier layer (mm)	EVOH 0.05	EVOH 0.02 + PET 0.03	EVOH 0.05	EVOH 0.05	EVOH 0.05
Molding condition (H / D)	0.3	0.3	0.5	0.3	0.3

Experimental Example 1. Measurement of oxygen permeability

Oxygen permeability was measured with respect to the molded object produced by the Example and the comparative example under the temperature of 23 degreeC, and the relative humidity conditions of 50%. On the other hand, in order to confirm whether the gas barrier layer was evenly distributed in the molded body, the specimens of the molded body were randomly cut and measured. The results are shown in Table 2 below.

Oxygen Permeability Test

Test Method: ASTM D 3985

Tester: OX-TRAN 702 (MOCON, USA)

-Test temperature: 23 ℃

-Exam time: 30 minutes

Measuring range: 0.1 to 2000 cc / m ² day

-Specimen size: width × length × height 40mm × 40mm × 3mm

	Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
Oxygen Permeability (cc / m 2 Day)	2	3	7	15	2

Referring to Table 2, it can be seen that the molded article oxygen permeability according to the present invention is low, thereby can be almost prevented from permeation of oxygen. This means that the gas barrier layer is evenly distributed over the entire area of the molded body. On the other hand, it was confirmed that the molded article of Comparative Example 1 had high oxygen permeability. It is determined that the gas barrier layer is damaged during molding of the molded body. In addition, in the case of Comparative Example 2 which is a non-foaming product, the oxygen permeability is low, but it can be confirmed that the thermal barrier property is not excellent in the thermal barrier test described later.

On the other hand, it was confirmed that the molded article of Comparative Example 1 had high oxygen permeability. It is determined that the gas barrier layer is damaged during molding of the molded body. In addition, in the case of Comparative Example 2 which is a non-foaming product, the oxygen permeability is low, but it can be confirmed that the thermal barrier property is not excellent in the thermal barrier test described later.

Experimental Example 2. Water vapor permeability measurement

Water vapor permeability was measured for the molded products prepared in Examples and Comparative Examples under a temperature of 37 ° C. and a relative humidity of 100% based on ASTM F 1249. The results are shown in Table 3 below.

	Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
Water vapor transmission rate (g / m 2 day)	8.5	17	18	19	3

Referring to Table 3, in the case of the molded article according to Example 1-3, the results were low as 8.5 g / m ² day, 17 g / m ² day and 18 g / m ² day, respectively. This means that the gas barrier layer is evenly distributed over the entire area of the molded body. In addition, in the case of Comparative Example 1, 19 g / m ² day was higher than the Example. It is judged that the gas barrier layer is damaged during molding of the molded article of Comparative Example 1. In addition, in the case of Comparative Example 2 which is a non-foaming product, the oxygen permeability is low, but it can be confirmed that the thermal barrier property is not excellent in the thermal barrier test described later.

Experimental Example 3. Thermal Insulation Measurement

In order to evaluate the thermal barrier properties of the molded articles according to the Examples and Comparative Examples, at a point 2 minutes after 100% of water at 70 ℃ (v / v) contained in the molded body, any point inside the molded body and the outside of the container The temperature at any point was measured. The results are shown in Tables 4 and 5:

[Equation 2]

T ₂ -T ₁ | ≥ 10 ℃

In Equation 2,

T ₁ is the outer surface temperature of the molded body measured when 1 minute has elapsed by containing 100 ° C water in the molded body at 20 ° C and 1 atm conditions,

T ₂ is the temperature of the water inside the molded body measured when 1 minute has elapsed after 100 minutes of water is contained in the molded body at 20 ° C. and 1 atm conditions.

	Example 1	Example 2	Example 3	Comparative Example 1	Comparative Example 2
T 1	40	38	40	75	80
T 2	95	92	90	84	80
T 2 -T 1 |	55	54	50	9	0

Referring to Table 4, the molded article according to the embodiment can be seen that the temperature difference between the temperature of the water contained in the molded body and the surface of the molded body is 10 ° C or more showing excellent heat shielding properties. On the other hand, the molded articles according to Comparative Examples 1 and 2 were | T ₂ -T ₁ | Were 27 degreeC and 0 degreeC, respectively, and the thermal barrier property was remarkably low. Therefore, it was confirmed that the molded article according to the present invention has excellent thermal barrier properties by including a PET foam sheet, thereby realizing excellent thermal insulation properties and handling safety.

In particular, by including the first and second foam sheets on both sides of the gas barrier layer was confirmed to have excellent thermal barrier properties.

Through this, it can be seen that the molded article according to the present invention has low water vapor permeability and oxygen permeability, and is excellent in thermal barrier property.

[Description of the code]

1: sheet

10: molded body

101: first foam sheet

101 ': second foam sheet

102: gas barrier layer

11: bottom

12: wall

13: flange

20: mold

21: female mold

22: male mold

23: decompression hole

Since the molded article according to the present invention includes the first and second foam sheets respectively on both sides of the gas barrier layer, oxygen and moisture permeability can be minimized, and when used in a food packaging container, decay of food due to oxygen and moisture It may be easy to preserve the food by preventing such.

Claims (13)

1. The first foam sheet, the gas barrier layer and the second foam sheet is a laminated structure sequentially, a molded body that satisfies the following equation 1,

   The first foam sheet and the second foam sheet is a foam of a polyester resin,

   The average thickness of the molded body ranges from 1 mm to 5 mm,

   A molded article characterized in that the oxygen permeability according to ASTM F 3985 is 20 cc / m ² · day or less, under conditions of 23 ° C .:

   [Equation 1]

   H / D ≥ 0.01

   In Equation 1,

   Forming a shaped body of the container structure including the receiving portion and the opening,

   H represents the depth of the receptacle and is 1 cm to 10 cm,

   D represents the diameter of the opening.
2. The method of claim 1,

   A molded article characterized in that the water vapor transmission rate according to ASTM F 1249 is 50 g / m ² · day or less under 37 ° C. and 100% relative humidity conditions.
3. The method of claim 1,

   The average thickness of the gas barrier layer is 0.01 to 2 mm,

   Molded body, characterized in that the average thickness of the first and second foam sheet is 0.5 to 1.5 mm each.
4. The method of claim 1,

   The gas barrier layer is a molded article comprising at least one of ethylene vinyl alcohol, polyvinylidene chloride and polyethylene terephthalate.
5. The method of claim 1,

   Melting point (T _m ) of the gas barrier layer is an average of 150 ℃ to 190 ℃,

   Melting point (T _m ) of the first and second foam sheet is characterized in that the average 240 ℃ to 260 ℃.
6. The method of claim 1,

   Polyester resin is a molded article characterized in that the polyethylene terephthalate (polyethylene terephthalate) resin.
7. The method of claim 1,

   The first and second foam sheet is a molded article, characterized in that each containing 0.5 to 9.0% by weight of calcium carbonate.
8. The method of claim 1,

   A molded article characterized by satisfying the following Equation 2:

   [Equation 2]

   T ₂ -T ₁ | ≥ 10 ℃

   In Equation 2,

   T ₁ is the outer surface temperature of the molded body measured when 1 minute has elapsed by containing 100 ° C water in the molded body at 20 ° C and 1 atm conditions,

   T ₂ is the temperature of the water inside the molded body measured when 1 minute has elapsed after 100 minutes of water is contained in the molded body at 20 ° C. and 1 atm conditions.
9. A packaging container comprising the molded article according to any one of claims 1 to 8.
10. The method of claim 9,

    The packaging container is a packaging container, characterized in that the food packaging container.
11. Disposing a sheet having a structure in which the first foam sheet, the gas barrier layer and the second foam sheet are sequentially stacked between the female mold and the male mold of the molding apparatus; And

    Pressing the male mold to form a molded body; Including;

    The first foam sheet and the second foam sheet is a method for producing a molded body, characterized in that the foam of the polyester resin.
12. The method of claim 11,

    The molding step includes applying heat so that the sheet surface temperature is 140 to 160 ° C, and molding the molded body by setting the surface temperatures of the female mold and the male mold to 60 to 200 ° C.
13. The method of claim 11,

    The female mold has a structure in which a pressure reducing hole for depressurizing an internal space is formed on one side.

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