KR20200002328A - Excellent heat resistance foam sheet, preparation method thereof, and food container comprising the same - Google Patents

Abstract

The present invention relates to a foam sheet comprising inorganic particles and a polyester resin, a manufacturing method thereof, and a food container using the same. The foam sheet comprises a polyester resin and a predetermined amount of inorganic particles, thereby having uniform thickness and excellent heat resistance.

Description

Foam sheet excellent in heat resistance, a method of manufacturing the same and a food container including the same {Excellent heat resistance foam sheet, preparation method etc, and food container comprising the same}

The present invention relates to a foam sheet comprising an inorganic particle and a polyester resin, a manufacturing method thereof and a food container using the same.

Products commonly used as food containers are divided into foamed and non-foamed. As the foamed product, a product extruded by mixing polystyrene with a foaming gas is used. The thickness can be maintained relatively thick, so there is an advantage in maintaining shape, insulation, and price competitiveness, but there are disadvantages in that harmful substances are detected at high temperatures. In the case of a non-foaming container, a product made of polypropylene that is heat-stable in the form of a film is used, but there is a low form change rate at a high temperature and no harmful substances are detected, but there are disadvantages in that the price is high and the heat insulation is not good.

If the most popular product for disposable heat-resistant containers is cups, it can be called a container. In the past, polystyrene foam containers were used. However, the issue of the detection of harmful substances at high temperatures was replaced by paper containers. There is this.

 As the life becomes more convenient in the modern society, the use of disposable products is increasing, and the demand for delivery food and convenience food products is increasing due to the increase of single households. Accordingly, the demand for food packaging containers is increasing, and it is safe from harmful substances. There is a growing consumer need for new container materials to which functions are given. Therefore, research on packaging containers with beautiful appearance, convenience, safety and eco-friendly performance is needed.

Korea Patent Publication 10-2005-0019243

The present invention provides a foam sheet having excellent heat resistance, an inorganic particle and a polyester resin, a manufacturing method thereof, and a food container including the same.

The present invention,

Including inorganic particles and polyester resin,

Melting point is 252 ° C to 260 ° C,

Elongation is 230% to 500% when foam sheet surface temperature is 160 ℃ after contact or non-contact heating,

A foam sheet satisfying the following Equation 1 may be provided:

[Equation 1]

| V ₁ -V ₀ | / V ₀ x 100 ≤ 10%

In Equation 1,

V ₀ is the volume of the foam sheet (mm ³ ) prior to exposure for 5 minutes in a 1 kw microwave oven,

V ₁ is the volume of the foam sheet in mm ³ after exposure to a ₁ kw microwave for 5 minutes.

In addition, the present invention,

Introducing an inorganic particle and a polyester resin into an extruder and extruding the foam to prepare a foam sheet;

The inorganic particles may provide a method for producing a foam sheet according to the invention to add 0.5% by weight to 5% by weight.

In addition, the present invention,

It includes a foam sheet containing a polyester resin and inorganic particles,

The content of the inorganic particles is 0.5% by weight to 5% by weight,

Melting point of the foam sheet is 252 ℃ to 260 ℃,

When the surface temperature is 160 ℃ after contact or non-contact heating, the elongation of the foam sheet is 230% to 500%,

A food container that satisfies Equation 2 may be provided:

[Equation 2]

0.01 ≤ H / D ≤ 0.4

In Equation 2,

To form a food container including a receiving unit,

H represents the depth of the outer side of a storage part, and is 1 cm-8 cm,

D shows the length of the outer side of an accommodating upper end.

Foam sheet according to the present invention has the advantage that by including the inorganic particles and the polyester resin, the thickness is uniform and excellent heat resistance.

1 is a cross-sectional image of a foam sheet according to the present invention taken by a scanning electronic microscope (Scanning Electronic Microscope, SEM).
Figure 2 is a schematic diagram showing an embodiment of a food container according to the present invention: (a) is an image of the food container viewed from the top, (b) is an image showing a side cross-sectional view of the food container.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

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

In the present invention, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Therefore, the configurations shown in the embodiments described herein are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. And variations.

It relates to a foam sheet having excellent heat resistance, an inorganic particle and a polyester resin, a manufacturing method thereof, and a food container including the same.

Hereinafter, the foam sheet according to the present invention will be described in detail.

Including inorganic particles and polyester resin,

Melting point is 252 ° C to 260 ° C,

Elongation is 230% to 500% when foam sheet surface temperature is 160 ℃ after contact or non-contact heating,

It provides a foam sheet satisfying the following equation (1):

[Equation 1]

| V ₁ -V ₀ | / V ₀ x 100 ≤ 10%

In Equation 1,

V ₀ is the volume of the foam sheet (mm ³ ) prior to exposure for 5 minutes in a 1 kw microwave oven,

V ₁ is the volume of the foam sheet in mm ³ after exposure to a ₁ kw microwave for 5 minutes.

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. Specifically, in the present invention, polyethylene terephthalate (PET) may be used.

The inorganic particles may be at least one selected from the group consisting of calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), talc (Talc), silica (Silica), and zirconium oxide (ZrO ₂ ). Specifically, the inorganic particles may be calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ) or talc (Talc). More specifically, the inorganic particles may be calcium carbonate (CaCO ₃ ). For example, the inorganic particles may be amorphous calcium carbonate (CaCO ₃ ). By including the inorganic particles as described above, the foam sheet of the present invention can exhibit a uniform sheet surface and excellent thermoformability.

The thermal conductivity of the inorganic particles may be 1.0 kcal / mh ℃ to 3.0 kcal / mh ℃. Specifically, the thermal conductivity of the inorganic particles may be 1.2 kcal / mh ℃ to 2.5 kcal / mh ℃, 1.5 kcal / mh ℃ to 2.2 kcal / mh ℃ or 1.8 kcal / mh ℃ to 2.0 kcal / mh ℃. More specifically, the thermal conductivity of the inorganic particles 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 foam sheet including the inorganic particles may have a uniform surface by exhibiting excellent thermal conductivity and may exhibit excellent thermoformability.

For example, the content of the inorganic particles may be 0.5% by weight to 5% by weight. Specifically, the content of the inorganic particles may be 1 wt% to 5 wt%, 1.5 wt% to 4.5 wt%, or 2 wt% to 3.5 wt%. More specifically, the content of the inorganic particles may be 1.0 wt% to 3.0 wt%, 3.0 wt% to 4.5 wt% or 0.8 wt% to 1.3 wt%.

In one example, the melting point of the foam sheet according to the present invention may be 252 ℃ to 260 ℃. Specifically, the melting point of the foam sheet may be 252.5 ℃ to 258 ℃ or 253 ℃ to 256 ℃. More specifically, the melting point of the foam sheet may be 253.5 ℃ to 255 ℃.

In another example, the foam sheet according to the present invention may be elongation of 230% to 500% when the foam sheet surface temperature is 160 ℃ after contact or non-contact heating. Specifically, the elongation of the foam sheet in the above conditions may be 240% to 400%, 260% to 350% or 245% to 300%. More specifically, the elongation of the foam sheet in the above conditions may be 240% to 300% or 250% to 280%.

By including the polyester and inorganic particles as described above, the foam sheet according to the present invention can exhibit excellent heat resistance. For example, the following equation 1 may be satisfied:

[Equation 1]

| V ₁ -V ₀ | / V ₀ x 100 ≤ 10%

In Equation 1,

V ₀ is the volume of the foam sheet (mm ³ ) prior to exposure for 5 minutes in a 1 kw microwave oven,

V ₁ is the volume of the foam sheet in mm ³ after exposure to a ₁ kw microwave for 5 minutes.

Specifically, the dimensional change rate before and after exposing the sample of the foam sheet to a 1 kw microwave for 5 minutes was measured. This is a measure corresponding to the actual use environment in the heat of the food container including the foam sheet. For example, the volume may mean a value calculated by multiplying the length, width, and thickness of the foam sheet, respectively. For example, the dimensional change rate according to Equation 1 may range from 0.01 to 5%, 0.01 to 3%, or 0.01 to 1%. By satisfying the value of Equation 1 in the above range, it can be seen that the foam sheet according to the present invention hardly changes the form even in use in a high temperature environment. As a result, it can be seen that the foam sheet according to the present invention is excellent in heat resistance.

In addition, the density of the foam sheet may be an average of 100 kg / ㎥ to 500 kg / ㎥. Specifically, the foam sheet may have an average of 100 kg / m 3 to 450 kg / m 3, 150 kg / m 3 to 400 kg / m 3 or 150 kg / m 3 to 300 kg / m 3, and more specifically, the density of the foam sheet. May be an average of 100 kg / m 3 to 300 kg / m 3 or 150 kg / m 3 to 250 kg / m 3. The density of the foam sheet as described above may be formed because calcium carbonate is uniformly mixed with the polyester resin and foamed. Accordingly, the density of the foam sheet can be increased and the impact resistance can be excellent.

In one example, the thickness of the foam sheet according to the present invention may be 0.5 mm to 5.0 mm. Specifically, the thickness of the foam sheet may be 1.0 mm to 5.0 mm, 1.5 mm to 4.0 mm or 2.0 mm to 3.0 mm, more specifically the thickness of the foam sheet is 1.0 mm to 3.0 mm or 2.0 mm to 3.5 May be mm.

In addition, the thickness of the foam sheet according to the present invention may be 15% or less per unit area 100cm ² . Specifically, the thickness variation of the foam sheet according to the present invention may be 12% or less, 10% or less, 8% or less or 7% or less per 100 cm ² unit area. More specifically, the thickness deviation of the foam sheet according to the present invention may be 1% to 10% or 5% to 8% per unit area 100cm ² .

As an example, the foam sheet 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 waterproof agent, a cell size expander, an infrared attenuator, 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 include physical blowing agents such as N ₂ , CO ₂ , freon, butane, pentane, neopentane, hexane, isohexane, heptane, isoheptane, methyl chloride and the like, and specifically, the present invention may include butane. Can be.

In addition, the present invention includes the step of introducing the inorganic particles and the polyester resin into the extruder and extrusion foaming to produce a foam sheet,

The inorganic particles provide a method for producing a foam sheet according to the present invention is added in 0.5% by weight to 5% by weight.

The inorganic particles may be mixed with the polyester resin in an amount of 0.5% by weight to 5% by weight and introduced into the extruder. Specifically, the polyester resin may be added 1% by weight to 5% by weight, 1.5% by weight to 4.5% by weight or 2% by weight to 3.5% by weight of inorganic particles. More specifically, the foam sheet may be added 1.0% by weight to 3.0% by weight, 3.0% by weight to 4.5% by weight or 0.8% by weight to 1.3% by weight of inorganic particles.

For example, the inorganic particles may be at least one selected from the group consisting of calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), talc (Talc), silica (Silica), and zirconium oxide (ZrO ₂ ). Specifically, the inorganic particles may be calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ) or talc (Talc). More specifically, the inorganic particles may be calcium carbonate (CaCO ₃ ). For example, the inorganic particles may be amorphous calcium carbonate (CaCO ₃ ). By adding the inorganic particles as described above, the manufacturing method of the foam sheet of the present invention can produce a foam sheet having a uniform sheet surface and excellent heat resistance.

In one example, the polyester resin may include the step of introducing the inorganic particles in the extruder by adding inorganic particles in the process of the polyester resin polymerization. Specifically, in the process of polymerizing the acid component and the diol component to polymerize the polyester resin, inorganic particles may be added and mixed. For example, the polyester resin may be in the form of pellets, granules, beads, chips, etc., and in some cases may be introduced into the extruder in the form of powder. Can be.

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. Specifically, in the present invention, polyethylene terephthalate (PET) may be used.

Method for producing a foam sheet according to the present invention may include the step of manufacturing a foam sheet by melting and extrusion foaming the polyester resin introduced into the extruder. Specifically, the polyester resin chip containing calcium carbonate may be melted to form a melt, followed by extrusion foaming. For example, the process of melting the polyester resin may be performed at a temperature of 260 ℃ to 300 ℃.

In one example, the step of preparing a foam sheet may include a foaming process for producing a foam sheet by foaming a polyester resin containing inorganic particles. The foaming process may be performed using various types of extruders. The foaming process can be carried out largely through bead foaming or extrusion foaming, with extrusion foaming being preferred. The extrusion foaming, by continuously extruding and foaming the resin melt, can simplify the process step, can be mass-produced, and prevents cracking, granular fracture, etc. between the beads during the foaming foam to better compressive strength Can be implemented.

In the manufacturing of the foam sheet of the present invention, the foam sheet may be formed to a thickness of 0.5 mm to 5.0 mm. Specifically, the foam sheet may be formed to a thickness of 1.0 mm to 5.0 mm, 1.5 mm to 4.0 mm or 2.0 mm to 3.0 mm, more specifically the foam sheet is 1.0 mm to 3.0 mm or 2.0 mm to 3.5 It can be formed in the thickness of mm.

In addition, the manufacturing method of the foam sheet according to the present invention can produce a foam sheet showing a thickness deviation of 15% or less per unit area 100cm ² . Specifically, the manufacturing method of the foam sheet according to the present invention can produce a foam sheet showing a thickness deviation of 12% or less, 10% or less, 8% or less or 7% or less per unit area 100cm ² . More specifically, the manufacturing method of the foam sheet according to the present invention can produce a foam sheet showing a thickness deviation of 1% to 10% or 5% to 8% per unit area 100cm ² .

As one example, the step of preparing a foam sheet according to the present invention, various types of additives may be added. The additive may be added in the fluid connection line, if necessary, or in the foaming process. Examples of additives may have barrier performance, hydrophilicity or waterproofing properties, thickeners, surfactants, hydrophilizing agents, heat stabilizers, waterproofing agents, cell size expanders, infrared attenuators, plasticizers, fire protection chemicals, It may comprise one or more functional additives selected from the group consisting of pigments, elastomers, extrusion aids, antioxidants, nucleating agents, antistatic agents and UV absorbers. Specifically, the foam sheet manufacturing method of the present invention may be added one or more of a thickener, nucleating agent, heat stabilizer and blowing agent, and may further include one or more of the functional additives listed above.

For example, the step of preparing the foam sheet of the present invention may be a thickener, a hydrophilizing agent, a heat stabilizer, a waterproofing agent, a cell size expander, an infrared attenuator, a plasticizer, a fire protection chemical, a pigment, an elastomer, an extrusion aid, an antioxidant, One or more additives selected from the group consisting of antistatic agents and UV absorbers may be introduced into the fluid connection line. Among the additives necessary for producing the foam sheet, additives not added to the fluid connection line can be added during the extrusion process.

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 include physical blowing agents such as N ₂ , CO ₂ , freon, butane, pentane, neopentane, hexane, isohexane, heptane, isoheptane, methyl chloride, and specifically, butane may be used in the present invention. have.

In addition, the present invention includes a foam sheet containing a polyester resin and inorganic particles,

The content of the inorganic particles is 0.5% by weight to 5% by weight,

Melting point of the foam sheet is 252 ℃ to 260 ℃,

When the surface temperature is 160 ℃ after contact or non-contact heating, the elongation of the foam sheet is 230% to 500%,

To provide a food container that satisfies the following equation 2:

[Equation 2]

0.01 ≤ H / D ≤ 0.4

In Equation 2,

To form a food container including a receiving unit,

H represents the depth of the outer side of a storage part, and is 1 cm-8 cm,

D shows the length of the outer side of an accommodating upper end.

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. Specifically, in the present invention, polyethylene terephthalate (PET) may be used.

The inorganic particles may be at least one selected from the group consisting of calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ), talc (Talc), silica (Silica), and zirconium oxide (ZrO ₂ ). Specifically, the inorganic particles may be calcium carbonate (CaCO ₃ ), titanium oxide (TiO ₂ ) or talc (Talc). More specifically, the inorganic particles may be calcium carbonate (CaCO ₃ ). For example, the inorganic particles may be amorphous calcium carbonate (CaCO ₃ ). By including the inorganic particles as described above, the food container of the present invention can exhibit a uniform sheet surface and excellent heat resistance.

For example, the content of the inorganic particles may be 0.5% by weight to 5% by weight. Specifically, the content of the inorganic particles may be 1 wt% to 5 wt%, 1.5 wt% to 4.5 wt%, or 2 wt% to 3.5 wt%. More specifically, the content of the inorganic particles may be 1.0 wt% to 3.0 wt%, 3.0 wt% to 4.5 wt% or 0.8 wt% to 1.3 wt%.

In one example, the melting point of the food container according to the present invention may be 252 ℃ to 260 ℃. Specifically, the melting point of the food container may be 252.5 ℃ to 258 ℃ or 253 ℃ to 256 ℃. More specifically, the melting point of the food container may be 253.5 ℃ to 255 ℃.

In another example, the foam sheet of the food container according to the present invention may be elongation of 230% to 500% when the foam sheet surface temperature is 160 ℃ after contact or non-contact heating. Specifically, the foam sheet of the food container may have elongation of 240% to 400%, 260% to 350% or 245% to 300% when the foam sheet surface temperature is 160 ° C. after contact or non-contact heating. More specifically, the foam sheet of the food container may have an elongation of 240% to 300% or 250% to 280% when the foam sheet surface temperature is 160 ℃ after contact or non-contact heating.

Figure 2 is a schematic diagram of a food container according to the present invention, (a) is an image of the food container viewed from the top, (b) is an image showing a side cross-sectional view of the food container. In FIG. 2, H represents the depth of the inside of the housing, 1 cm to 8 cm, and D represents the length of the outside of the top of the housing. When the food container is rectangular, D may calculate the H / D value based on the average value of D ₁ and D ₂ . Hereinafter, the structure of the food container of the present invention will be described in detail.

By including the polyester and inorganic particles as described above, the food container according to the present invention can exhibit excellent heat resistance. For example, the following Equation 2 may be satisfied:

[Equation 2]

0.01 ≤ H / D ≤ 0.4

In Equation 2,

To form a food container including a receiving unit,

H represents the depth of the inner side of the housing, and is 1 cm to 8 cm,

D shows the length of the outer side of an accommodating upper end.

For example, in Equation 2, the H / D value may be 0.01 to 0.37, 0.05 to 0.35, or 0.1 to 0.38. Specifically, the value of H in Equation 2 may be 1.5 cm to 7.0 cm, 2.0 cm to 5.0 cm or 4.0 cm to 7.5 cm. More specifically, the value of H in Equation 2 may be 3.0 cm to 6.0 cm or 2.5 cm to 4.5 cm.

In addition, the food container according to the present invention may have a side / bottom thickness ratio (thickness of the side / thickness of the bottom surface) of 0.8 or more. Specifically, the side / bottom thickness ratio of the food container may be 0.85 or more, 0.9 or more, or 0.95 or more. More specifically, the side / bottom thickness ratio of the food container may be 0.85 to 1.0 or 0.9 to 0.97. At this time, the thickness of the side is a value measured the thickness of the side of the center point in the height direction of the food container, the thickness of the bottom surface is a value measured the thickness of the center of the horizontal and vertical bottom of the bottom surface of the food container. Say.

In one example, the food container of the present invention may have a compressive strength of 11 kgf · cm / cm ² to 40 kgf · cm / cm ² . Specifically, when the food container of the present invention has an H / D value of 0.4, the compressive strength is 17 kgf · cm / cm ² to 22 kgf · cm / cm ² or 18 kgf · cm / cm ² to 23 kgf · cm / can be ² cm. More specifically, the food container of the present invention may have a compressive strength of 19 kgf · cm / cm ² to 21 kgf · cm / cm ² . By having such a compressive strength, the food container of the present invention can be excellent in durability.

In another example, the food container of the present invention may satisfy the following Equation 1:

[Equation 1]

| V ₁ -V ₀ | / V ₀ x 100 ≤ 10%

In Equation 1,

V ₀ is the volume of the foam sheet (mm ³ ) prior to exposure for 5 minutes in a 1 kw microwave oven,

V ₁ is the volume of the foam sheet in mm ³ after exposure to a ₁ kw microwave for 5 minutes.

Specifically, the dimensional change rate before and after exposing the sample of the foam sheet to a 1 kw microwave for 5 minutes was measured. This is a measure corresponding to the actual use environment in the heat of the food container including the foam sheet. For example, the volume may mean a value calculated by multiplying the length, width, and thickness of the foam sheet, respectively. For example, the dimensional change rate according to Equation 1 may range from 0.01 to 5%, 0.01 to 3%, or 0.01 to 1%. By satisfying the value of Equation 1 within the above range, it can be seen that the foam sheet according to the present invention hardly undergoes a change in shape even in use in a high temperature environment. As a result, it can be seen that the food container according to the present invention is excellent in heat resistance.

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

1.0 weight% of calcium carbonate and a polyethylene terephthalate resin having a melting point of 254 ° C. are mixed, 0.5 parts by weight of pyromellitic dianhydride and 0.1 parts by weight of Irganox (IRG 1010) are mixed based on 100 parts by weight of polyethylene terephthalate resin, The resin melt was prepared by heating to 280 ° C. Then, 3 parts by weight of butane was added to the first extruder as a blowing agent based on 100 parts by weight of polyethylene terephthalate (PET) resin, followed by extrusion foaming, to prepare a polyethylene terephthalate resin foam sheet having a thickness of 2 mm.

Preparation Example 2

A foam sheet was prepared in the same manner as in Preparation Example 1, except that 3.0 wt% of calcium carbonate (CaCO ₃ ) was added.

Comparative Production Example 1

Foam sheet was prepared in the same manner as 1 except that 0.6 wt% of Talc was added.

Comparative Production Example 2

Foam sheet was prepared in the same manner as in Preparation Example 1, except that 1.0 wt% of Talc was added.

Example  One

The foam sheet prepared in Preparation Example 1 passes through an IR ceramic heater zone and is set to an upper heater of 400 ° C., a lower heater of 280 ° C., and a residence time of 30 seconds. After the temperature was 160 ° C., a food container was prepared by pressing the mold temperature plug at 60 ° C. and the mold at 120 ° C. for 10 seconds.

At this time, the H / D was 0.38 in depth (H) was prepared a food container of a square of 5cm, the top length is 13cm.

Example 2

A food container was prepared under the same conditions as in Example 1 except that the foam sheet prepared in Preparation Example 2 was used.

Comparative Example 1

A food container was prepared under the same conditions as in Example 1 except that the foam sheet prepared in Comparative Preparation Example 1 was used.

Comparative Example 2

A food container was prepared under the same conditions as in Example 1 except that the foam sheet prepared in Comparative Preparation Example 2 was used.

Experimental Example 1

In order to confirm the physical properties of the foam sheet and the food container according to the present invention, the thickness deviation, melting point, high temperature elongation of the foam sheet of Preparation Example 1 and Preparation Example 2 was measured, the food containers of Examples 1 and 2 Formability and compressive strength were measured for the target, and the results are shown in Table 1. Also. The cross section of the foam sheet of the foam sheet of Preparation Example 1 was taken by a scanning electron microscope (SEM), the results are shown in FIG.

At this time, the high temperature elongation was measured by placing the tensile strength tester in the oven, the specimen size was 70mm in height x 25mm in width, the test speed was 50mm / min, the gap size was 20mm, and was measured after staying at the oven temperature for 200 seconds for 30 seconds. .

Preparation Example 1 Preparation Example 2 Comparative Production Example 1 Comparative Production Example 2 Sheet Inorganic particles Calcium carbonate Calcium carbonate Talc Talc Content (% by weight) 1.0 3.0 0.6 1.0 Elongation at high temperature (%) 250 270 200 220 Thickness deviation (%) 7 6 10 20

Looking at Table 1, the foam sheet of Preparation Examples 1 and 2 has a thickness deviation of 10% or less, compared to the foam sheet of Comparative Preparation Examples 1 and 2 10% or more, the foam sheet according to the present invention has a constant thickness And it can be confirmed that the surface is uniform. In addition, the foam sheet of Preparation Examples 1 and 2 has a high temperature elongation of 250% or more and the foam sheet of Comparative Preparation Examples 1 and 2 is 220% or less, considering that the foam sheet according to the present invention has excellent high temperature elongation. You can see that. In addition, looking at Figure 1, it can be seen that the foam sheet of Example 1 is uniform cell expression uniformity.

Experimental Example 2

In order to confirm the physical properties of the food container according to the invention, the side / bottom thickness ratio, heat resistance and compressive strength of the food containers of Examples 1, 2, Comparative Example 1 and Comparative Example 2 were measured, and the results Table 2 shows.

At this time, the side-to-side thickness ratio measured the thickness of the center portion of the side and the bottom surface to represent the ratio of the bottom surface (bottom) thickness to the side thickness.

In addition, the heat resistance measurement was measured after heating the water at 80 ℃ in a food container using a 1kw microwave oven for 2 minutes, O means undeformed form when visually judged, X means form deformation. do.

In addition, the compressive strength was measured using a tensile strength tester, when the bottom surface of the food container is located upward, the maximum load was measured when the test speed is compressed to 50mm / min.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Molding Side / bottom thickness ratio 0.9 0.93 0.78 0.65 Heat resistance (1kw) ○ ○ × × Compressive strength
(kgfcm / cm ² ) 15 20 7 8

Looking at Table 2, Example 1 and Example 2 has a side / bottom thickness ratio of 0.9 or more, while the thickness ratio of the side and the bottom surface is similar, while Comparative Example 1 and Comparative Example 2 is less than 0.8 the bottom side is a little thicker than the side Able to know. In addition, it turns out that Example 1 and Example 2 are excellent in heat resistance (the shape does not deform | transform when heated using a 1kw microwave oven). In addition, Example 1 and Example 2 exhibits a compressive strength of 15 kgf · cm / cm ² or more, it can be seen that it has an excellent strength compared to the comparative example including talc.

Claims (10)

Including inorganic particles and polyester resin,
Melting point is 252 ° C to 260 ° C,
Elongation is 230% to 500% when foam sheet surface temperature is 160 ℃ after contact or non-contact heating,
Foam sheet satisfying the following equation 1:
[Equation 1]
| V ₁ -V ₀ | / V ₀ x 100 ≤ 10%
In Equation 1,
V ₀ is the volume of the foam sheet (mm ³ ) prior to exposure for 5 minutes in a 1 kw microwave oven,
V ₁ is the volume of the foam sheet in mm ³ after exposure to a ₁ kw microwave for 5 minutes. The method of claim 1,
The polyester resin sheet is at least one member 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 method of claim 1,
The average thickness of the foam sheet is 0.5 mm to 5 mm,
Foam sheet, characterized in that the thickness deviation per unit area 100 cm ² is 15% or less. The method of claim 1,
The content of the inorganic particles is 0.5% by weight to 5% by weight foam sheet. The method of claim 4, wherein
The inorganic particles are foam seats, characterized in that the calcium carbonate. Introducing an inorganic particle and a polyester resin into an extruder and extruding the foam to prepare a foam sheet;
The inorganic particles is a manufacturing method of the foam sheet according to claim 1, characterized in that the addition in 0.5% by weight to 5% by weight. It includes a foam sheet containing a polyester resin and inorganic particles,
The content of the inorganic particles is 0.5% by weight to 5% by weight,
Melting point of the foam sheet is 252 ℃ to 260 ℃,
When the surface temperature is 160 ℃ after contact or non-contact heating, the elongation of the foam sheet is 230% to 500%,
Food container that satisfies the following equation 2:
[Equation 2]
0.01 ≤ H / D ≤ 0.4
In Equation 2,
To form a food container including a receiving unit,
H represents the depth of the outer side of a storage part, and is 1 cm-8 cm,
D shows the length of the outer side of an accommodating upper end. The method of claim 7, wherein
Food containers with a side / bottom thickness ratio (thickness on the side / thickness on the bottom) of the food container being 0.8 or more. The method of claim 7,
A food container having a compressive strength of 11 kgf · cm / cm ² to 40 kgf · cm / cm ² . The method of claim 7, wherein
Food container that satisfies the following equation 1:
[Equation 1]
| V ₁ -V ₀ | / V ₀ x 100 ≤ 10%
In Equation 1,
V ₀ is the volume of the foam sheet (mm ³ ) prior to exposure for 5 minutes in a 1 kw microwave oven,
V ₁ is the volume of the foam sheet in mm ³ after exposure to a ₁ kw microwave for 5 minutes.

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