KR20200126740A - Containers comprising Polyethylene terephthalate Foam sheet with improvement Thermal Insulation, and Preparation Method Thereof - Google Patents

Abstract

The present invention relates to a container with improved insulation and a manufacturing method thereof, wherein the container contains a polyethylene terephthalate (PET) foam sheet having high crystallinity. Since the container has a simple structure in which a body and a bottom part containing the polyester foam sheet, in particular, the polyethylene terephthalate (PET) foam sheet with high crystallinity are bonded, the container is economical, environmentally friendly, and harmless to the human body, and has excellent heat resistance and thermal insulation properties so as to maintain the temperature of hot/cold beverages for a long time.

Description

{Containers comprising Polyethylene terephthalate Foam sheet with improvement Thermal Insulation, and Preparation Method Thereof}

The present invention relates to a container with improved insulation properties, including a polyethylene terephthalate (PET) foam sheet having high crystallinity, and a manufacturing method thereof.

Products used as disposable beverage containers are divided into foaming type and non-foaming type. In general, a foamed container is a product obtained by mixing polystyrene with a foaming gas and extruded, and the foamed container has the advantages of maintaining shape, insulating properties, and price competitiveness as it can maintain a relatively thick thickness, but a material that is harmful to the human body at high temperatures. There is a problem with it being released. Therefore, foaming container materials using polyethylene terephthalate (PET) that do not release harmful substances at high temperatures are gradually being used. Due to their high crystallinity, molding is difficult to manufacture thermoformed containers with deep shapes such as beverage containers. There is a bad difficulty.

In addition, as a non-foaming container, a cup made of paper with high processability or a product formed by forming a heat-stable polypropylene film into a cup shape is used.The non-foaming container has a small change in shape at high temperature and no harmful substances are detected, but the price There is a problem with this expensive and poor insulation.

In recent years, interest in the environment and the quality of life of individuals are increasing, a multifunctional container that can be reused or recycled so that it is environmentally friendly and harmless to the human body, and can completely preserve the state of the material contained in the container for a long time. The need for

Therefore, there is a need for development of a beverage container that is safe and environmentally friendly to the human body while maintaining a constant temperature for a long time due to excellent heat resistance and/or thermal insulation properties, as well as being able to maintain a constant temperature of a hot and/or cold/hot beverage for a long time. .

Republic of Korea Patent Publication No. 2004-0052986 Republic of Korea Patent Publication No. 2010-0083465

Accordingly, the object of the present invention is cost-competitive, safe for the human body, eco-friendly, excellent heat resistance and/or thermal insulation, so that the temperature can be kept constant even when a liquid of high temperature and/or cold temperature is contained, and form stability against heat It is to provide this excellent container for beverages and a method of manufacturing the same.

The present invention in one embodiment,

Body comprising a polyester foam sheet; And

It is located at the lower end of the body and has a bottom portion including a polyester foam sheet,

The body and the bottom portion are joined to each other to form a sealed structure,

The ratio (H/D) of the side height (H) of the body and the diameter (D) of the bottom part is 0.7 or more,

The crystallinity of the polyester foam sheet is 10% to 30%,

After 3 minutes have elapsed with 100℃ water, a container with a temperature difference of 10℃ or more between the outer surface of the body and the water inside is provided.

In addition, the present invention, in one embodiment, provides a method of manufacturing the container.

The container according to the present invention is economical, eco-friendly, and harmless to the human body by using a polyester foam sheet with high crystallinity, and it is possible to manufacture a container with a deep depth, and the manufactured container has excellent heat resistance and thermal insulation properties. When used for hot and/or cold beverages, there is an advantage that the temperature can be maintained for a long time.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be described in detail in the detailed description.

However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all changes, 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, actions, components, parts, or a combination thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

In the present invention, "cell" refers to a microstructure expanded by foaming in a polymer.

The present invention relates to a container and a method of manufacturing the same.

In recent years, interest in the environment and the quality of life of individuals are increasing, a multifunctional container that can be reused or recycled so that it is environmentally friendly and harmless to the human body, and can completely preserve the state of the material contained in the container for a long time. Although the demand for is increasing, a material capable of meeting the above demand has not yet been developed.

Accordingly, the present invention provides a container including a polyester foam sheet and a method for manufacturing the same.

Since the container according to the present invention has a simple structure in which a body including a polyester foam sheet and a bottom part are bonded, it is economical, eco-friendly, and harmless to the human body, and has excellent heat resistance and/or heat insulation, so that high temperature and/or There is an advantage of maintaining the temperature of a cold or hot beverage for a long time.

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

Vessel

The present invention in one embodiment,

Body comprising a polyester foam sheet; And

It is located at the lower end of the body and has a bottom portion including a polyester foam sheet,

The body and the bottom portion are joined to each other to form a sealed structure,

The ratio (H/D) of the side height (H) of the body and the diameter (D) of the bottom part is 0.7 or more,

The crystallinity of the polyester foam sheet is 10% to 30%,

After 3 minutes have elapsed with 100℃ water, a container with a temperature difference of 10℃ or more between the outer surface of the body and the water inside is provided.

The container according to the present invention may be composed of a polyester foam sheet. Here, the polyester foam sheet includes a polyester resin as a main component and is inexpensive, does not emit substances harmful to the human body even at high temperatures, and has eco-friendly advantages. These polyester foam sheets include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), It may include one or more polyester resins selected from the group consisting of polyethylene adipate (PEA), polylactic acid (PLA), and polyglycolic acid (PGA). As an example, the polyester foam sheet may include polyethylene terephthalate (PET).

In addition, the polyester foam sheet may have a high crystallinity of 10% to 30%. Specifically, the polyester foam sheet has high crystallinity 10% to 30%, 10% to 27%, 10% to 25%, 10% to 22%, 10% to 20%, 10% to 15%, 12 % To 30%, 14% to 30%, 16% to 30%, 10% to 18%, 11% to 19%, 11% to 17%, 12% to 16%, 13% to 17%, 15% to It may have a crystallinity of 19%, 17.5% to 20%, 19% to 23%, 20% to 25%, 20.5% to 25%, 17% to 22%, 14% to 18%, or 12% to 14%. .

In addition, the polyester foam sheet may have an average cell density of 800 cells/cm2 to 25,000 cells/cm2, specifically 800 cells/cm2 to 23,000 cells/cm2, 800 cells/cm2 to 20,000 cells/cm2, 800 cells /Cm2 to 15,000 cells/cm2, 800 cells/cm2 to 11,000 cells/cm2, 800 cells/cm2 to 8,000 cells/cm2, 1,000 cells/cm2 to 5,500 cells/cm2, 4,500 cells/cm2 to 6,000 cells/cm2, 15,000 cells /Cm2 to 25,000 cells/cm2, 20,000 cells/cm2 to 24,500 cells/cm2, 21,000 cells/cm2 to 24,500 cells/cm2, 900 cells/cm2 to 2,000 cells/cm2, 900 cells/cm2 to 1,800 cells/cm2, or 1,200 cells/㎠ to 1,600 cells/cm2.

In addition, the average thickness of the polyester foam sheet may be 0.5mm to 3mm. Specifically, the thickness of the foam sheet is 0.5mm to 2.5mm, 1.0mm to 2.5mm, 1.0mm to 2.5mm, 1.5mm to 2.5mm, 2.0mm to 2.5mm, 1.0mm to 2.0mm, 0.5mm to 1.5mm , 0.5 mm to 1.0 mm, 0.8 mm to 1.7 mm, 0.8 mm to 1.2 mm, or 1.2 mm to 1.7 mm.

The present invention can prevent deformation of the container from stacked load and/or external impact by having the above configuration, as well as suppress deformation of the container due to temperature change, and increase the heat resistance and heat insulation effect of the container. I can.

As an example, in the case of evaluating the volume change before and after leaving the container in an oven at 100° C. for 3 minutes because the container is less deformed according to temperature change, the volume change rate may be 5% or less. Here, the "volume" is a value calculated by multiplying the width of the bottom of the container and the side length of the body, and the container is 0.01% to 5%, 0.5% to 5%, 0.5% to 4%, 0.5% to It may have a volume change rate of 3%, 0.5% to 2%, 1% to 4%, 2% to 4%, 3% to 5%, or 3.5% to 5%. The fact that the rate of change in the volume of the container at a high temperature is 5% or less means that the container has excellent heat resistance, so that there is little change in the shape of the container even at a high temperature.

As another example, when the container is filled with water at 100° C. to be 70% (v/v) of the total volume inside the container under ambient conditions at room temperature (23±2° C.), 3 minutes elapsed In the case of measuring the temperature of the water contained in the container and the outer surface of the body, the temperature difference between the water in the container and the outer surface of the body may be 10°C or more, and specifically 10 to 35°C, 10 to 30°C, 10 to It may be 20 ℃ or 10 to 16 ℃. If the temperature difference between the water in the container and the outer surface of the container is 10℃ or more, the temperature difference between the inside and the outside of the container is kept relatively high, and the heat barrier property of the container is excellent, and accordingly, the temperature of the beverage contained in the container is increased. It means that it can be preserved effectively.

Further, the container according to the present invention includes a body including the above-described polyester foam sheet and a bottom portion located at the lower end of the body.

Here, the shape of the body is not particularly limited, but in consideration of formability or workability, a cylinder having the same shape and size at the top and bottom of the body, n-angle (n=5 to 20 integer) pillars; The shape of the upper and lower ends of the body is the same, but the length or diameter of the upper end is larger than the length or diameter of the lower end. It may be a truncated cone, n-angle (n = an integer of 5 to 20) horn-shaped tubular shape. For example, the body may have a circular column shape, or a truncated cone shape of the upper light and lower side.

In addition, the bottom portion may be bonded to the inside of the lower end of the tubular body to form a structure to seal the lower end of the tubular body, and accordingly, the container of the present invention may provide a space to contain a liquid substance. To this end, the bottom portion may have the same shape as the inner bottom of the body, and the size may be the same or smaller than the inner bottom of the body.

In addition, the bottom portion may be bonded by thermal fusion or ultrasonic bonding, or may be bonded to the inner bottom of the body by an adhesive or an adhesive sheet. More specifically, the bottom portion is inserted by pushing it up inside the bottom of the body, and an adhesive or adhesive sheet containing a low melting point polyester resin is positioned between the inserted bottom portion and the inner bottom of the body to bond the bottom portion and the body. In this way, the bottom of the beverage container can be completely sealed.

At this time, the low melting point polyester resin may include a repeating unit represented by the following Chemical Formulas 1 and 2 to further solidify the adhesion of the body and the bottom including the polyester resin foam sheet:

In Formula 1 and Formula 2,

m and n represent the mole fraction of repeating units contained in the low melting point polyester resin,

Based on m+n=1, n is 0.05 to 0.5.

Specifically, the low melting point polyester resin may be a copolymer polyester resin having a structure including a repeating unit represented by Chemical Formulas 1 and 2. The repeating unit represented by Chemical Formula 1 represents a repeating unit of polyethylene terephthalate (PET), and the repeating unit represented by Chemical Formula 2 is used to improve the tearing properties of a polyester resin including a polyethylene terephthalate (PET) repeating unit. Functions. Specifically, the repeating unit represented by Formula 2 includes a methyl group (-CH ₃ ) in the ethylene chain bonded to terephthalate as a side chain, thereby securing a space so that the main chain of the polymerized resin can rotate, thereby increasing the degree of freedom of the main chain and The softening point (Ts) and/or the glass transition temperature (Tg) can be adjusted by inducing a decrease in crystallinity of the resin. This may exhibit the same effect as in the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to lower the crystallinity of the conventional crystalline polyester resin.

On the other hand, the container may have a side height (H) of 5 cm to 20 cm, specifically 5 cm to 20 cm, 5 cm to 18 cm, 5 cm to 16 cm, 5 cm to 14 cm, 5 Cm to 12 cm, 5 cm to 10 cm, 8 cm to 20 cm, 10 cm to 20 cm, 12 cm to 20 cm, 14 cm to 20 cm, 16 cm to 20 cm, 7 cm to 18 cm, 7 cm to It may be 16 cm or 7 cm to 14 cm.

In addition, the container may have a constant ratio of the size of the bottom portion to the side height (H) of the body. Specifically, when the shape of the body is a cylindrical or truncated tubular shape, the shape of the bottom joined to the inner bottom of the body is circular, and at this time, the ratio of the side height (H) of the body and the diameter of the bottom (D) (H/D) Is 0.7 or more, more specifically 0.7 to 3.0; 0.9 to 3.0; 1.0 to 3.0; 1.1 to 3.0; 1.2 to 3.0; 1.2 to 2.5; 1.2 to 2.0; 1.2 to 1.8; 1.2 to 1.5; 1.3 to 1.8; 1.3 to 1.6; 1.4 to 1.9; 1.4 to 1.7 or 1.5 to 1.8.

The present invention can more stably contain beverages by controlling the ratio (H/D) of the body side height (H) of the container and the size (D) of the bottom portion to the above range.

Further, the body and the bottom portion may have an average thickness ratio of 0.9 or more, specifically 0.9 to 1.1 or 0.95 to 1.05, and in some cases, may be close to 1.

Since the container of the present invention is individually cut and bonded to the body and the bottom, such as a disposable cup, it can be easily manufactured even with a foam sheet having high crystallinity, and a container manufactured under high temperature and/or pressure conditions such as conventional press molding Compared to those, since elongation of the foam sheet does not occur and the average thickness ratio of the body and the bottom is high, it can be usefully used as a container for a hot and/or cold beverage.

Container manufacturing method

In addition, the present invention in one embodiment,

Pushing and inserting the bottom part including the polyester foam sheet to the inner bottom of the body including the polyester foam sheet; And

Including the step of manufacturing a container having a sealed structure by bonding the inserted bottom portion and the body,

The ratio (H/D) of the side height (H) of the body and the diameter (D) of the bottom part is 0.7 or more,

The crystallinity of the polyester foam sheet is 10% to 30%,

The manufactured container contains 100°C water and after 3 minutes has elapsed, a method of manufacturing a container in which the temperature difference between the outer surface of the body and the inner water is 10°C or more is provided.

The manufacturing method of the container according to the present invention can be carried out by bonding the body and the bottom portion each comprising a polyester foam sheet having high crystallinity with a crystallinity of 10% to 30%.

Specifically, the manufacturing method includes the step of pushing and inserting the bottom portion including the polyester foam sheet to the inner bottom of the body including the polyester foam sheet.

In this case, the body is a cylinder having the same shape and size at the top and bottom, and an n-angle (n=an integer of 5-20) pillars; The shape of the top and bottom of the body is the same, but the length or diameter of the top is larger than the length or diameter of the bottom. It may be a truncated cone, n-angle (n = an integer of 5 to 20) cone-shaped tubular shape. It can be manufactured according to an appropriate method. For example, if the body has a cylindrical shape, it may be manufactured by using an annular nozzle when manufacturing a polyester foam sheet, and in some cases, a poly cut into a rectangle using a low melting point polyester resin adhesive or an adhesive sheet. It can be produced by rolling and bonding to both ends of the ester foam sheet.

In addition, the bottom portion may have the same shape as the inner bottom of the body thus manufactured, and the size may be the same or smaller than the inner bottom of the body.

In addition, the manufacturing method includes the step of bonding the bottom portion to the bottom of the body by applying heat and/or ultrasonic waves to a portion where the inserted bottom portion and the inner side of the body contact each other.

The above step is a step of sealing the bottom of the body by bonding the body and the bottom, which can be performed through thermal fusion or ultrasonic bonding, and in some cases, the thickness direction surface of the bottom where the body touches and the inner surface of the bottom of the body touches It can be carried out by applying heat to the area where the bottom and the body contact with each other so that heat is transferred to an adhesive or adhesive sheet including a low melting point polyester resin positioned between.

In this case, the bonding step may be performed by applying a temperature of 100°C to 400°C when bonding by applying heat, specifically 100°C to 350°C, 100°C to 300°C, 100°C to 250°C, 100°C It can be carried out by adding a temperature of to 200 ℃, 100 ℃ to 150 ℃, or 200 ℃ to 400 ℃.

In addition, the present invention in the step of bonding, when using an adhesive or an adhesive sheet, before the step of pushing the bottom part to the bottom of the body to insert,

Applying an adhesive containing a low-melting-point polyester resin or laminating an adhesive sheet on the inner bottom of the body; or

It may further include the step of applying an adhesive including a low melting point polyester resin or laminating an adhesive sheet on the side of the bottom in the thickness direction.

Here, the low-melting-point polyester resin included in the adhesive and the adhesive sheet may include a repeating unit represented by the following Chemical Formulas 1 and 2 to further strengthen the adhesion of the body and the bottom including the polyester resin foam sheet:

[Formula 1]

[Formula 2]

In Formula 1 and Formula 2,

m and n represent the mole fraction of repeating units contained in the low melting point polyester resin,

Based on m+n=1, n is 0.05 to 0.5.

Specifically, the low melting point polyester resin may be a copolymer polyester resin having a structure including a repeating unit represented by Chemical Formulas 1 and 2. The repeating unit represented by Chemical Formula 1 represents a repeating unit of polyethylene terephthalate (PET), and the repeating unit represented by Chemical Formula 2 is used to improve the tearing properties of a polyester resin including a polyethylene terephthalate (PET) repeating unit. Functions. Specifically, the repeating unit represented by Formula 2 includes a methyl group (-CH ₃ ) in the ethylene chain bonded to terephthalate as a side chain, thereby securing a space so that the main chain of the polymerized resin can rotate, thereby increasing the degree of freedom of the main chain and The softening point (Ts) and/or the glass transition temperature (Tg) can be adjusted by inducing a decrease in crystallinity of the resin. This may exhibit the same effect as in the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to lower the crystallinity of the conventional crystalline polyester resin.

When the molar fraction of the total resin is 1, the copolymerized polyester resin may include 0.5 to 1 repeating units represented by Chemical Formulas 1 and 2, specifically 0.55 to 1; 0.6 to 1; 0.7 to 1; 0.8 to 1; 0.5 to 0.9; 0.5 to 0.85; 0.5 to 0.7; Alternatively, it may be included in 0.6 to 0.95.

In addition, the molar fraction of the repeating unit represented by Formula 2 included in the copolymerized polyester resin may be 0.01 to 1 when the total molar fraction of the repeating unit represented by Formula 1 and Formula 2 is 1 (m+n=1), Specifically 0.05 to 1; 0.05 to 0.9; 0.05 to 0.8; 0.05 to 0.7; 0.05 to 0.6; 0.05 to 0.5; 0.05 to 0.4; 0.05 to 0.3; 0.1 to 0.3; 0.55 to 1; 0.6 to 1; 0.7 to 1; 0.8 to 1; 0.5 to 0.9; 0.5 to 0.85; 0.5 to 0.7; 0.6 to 0.95; 0.05 to 0.4, 0.15 to 0.35; Or 0.2 to 0.3. Herein, the copolymerized polyester resin in which the molar fraction of the repeating unit represented by Formula 1 is 0 (m=0) and the molar fraction of the repeating unit represented by Formula 2 is 1 (n=1) has the repeating unit represented by Formula 2 as a main chain. It can have a structure that includes.

In addition, the softening point of the copolymer polyester may be 100 ℃ to 130 ℃, specifically 110 ℃ to 120 ℃; 115°C to 125°C; 118°C to 128°C; 120°C to 125°C; 121°C to 124°C; It may be 124 ℃ to 128 ℃ or 119 ℃ to 126 ℃.

Furthermore, the copolymerized polyester resin may have a glass transition temperature (Tg) of 50°C or higher. Specifically, the glass transition temperature may be 50 ℃ to 80 ℃, more specifically 50 ℃ to 60 ℃, 60 ℃ to 70 ℃, 70 ℃ to 80 ℃, 50 ℃ to 55 ℃, 55 ℃ to 60 ℃, 60 It may be from ℃ to 65 ℃, 65 ℃ to 70 ℃, 68 ℃ to 75 ℃, 54 ℃ to 58 ℃, 58 ℃ to 68 ℃, 59 ℃ to 63 ℃, or 55 ℃ to 70 ℃.

The copolymerized polyester resin according to the present invention includes the repeating unit represented by Chemical Formula 2, and the softening point (Ts) and/or the glass transition temperature (Tg) of the polyester resin can be adjusted within the above range. It can implement adhesiveness.

On the other hand, the polyester foam sheet may be prepared from raw materials commonly used in the art. Specifically, the polyester foam sheet may contain a polyester-based resin obtained by reacting a dicarboxylic acid component and a glycol component or reacting a hydroxycarboxylic acid component.

Here, as the dicarboxylic acid component, at least one selected from the group consisting of terephthalic acid, naphthalene dicarboxylic acid, and adipic acid may be used.

In addition, the glycol component is 1 selected from the group consisting of ethylene glycol, butylene glycol, and 2-methyl-1,3-propanediol. You can use more than one species.

In addition, the hydroxycarboxylic acid component may be one or more selected from the group consisting of lactic acid and glycolic acid, but is not limited thereto.

As an example, the polyester foam sheet used in the present invention may be polyethylene terephthalate (PET) obtained by reacting terephthalic acid and ethylene glycol.

On the other hand, the polyester resin may be introduced in the form of a pellet, granule, bead, chip, powder, etc., and in some cases, introduced in a molten state. It could be.

As an example, the polyester resin may be introduced into an extruder in the form of a chip to be extruded and foamed. In this case, a resin chip at a temperature of 260° C. to 300° C. for melting the resin chip May go through the process of melting.

In addition, in the step of manufacturing the foam sheet, various types of additives may be introduced into the fluid connection line as necessary, or may be introduced during the foaming process when the polyester-based resin is introduced into the extruder for functionalization of the foam sheet.

Specifically, the additives may impart a barrier performance, a hydrophilic function or a waterproof function to the foam sheet, and a thickener, a surfactant, a hydrophilic agent, a heat stabilizer, a waterproof agent, a cell size enlarger, an infrared attenuator, a plasticizer, It may contain one or more selected from the group consisting of fire protection chemicals, pigments, elastomers, extrusion aids, antioxidants, nucleating agents, anti-rotation agents, and UV absorbers.

As an example, the foam sheet manufacturing method of the present invention may include one or more of a thickener, a nucleating agent, a heat stabilizer, and a foaming agent, and may further include one or more of the functional additives listed above.

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

In addition, the heat stabilizer may be an organic or inorganic phosphorus compound. Such organic or inorganic phosphorus compounds may be, for example, phosphoric acid and organic esters thereof, phosphorous acid and organic esters thereof. For example, the heat stabilizer may be a commercially available material, and may be phosphoric acid, alkyl phosphate or aryl phosphate, and more specifically, triphenyl phosphate, but is not limited thereto.

In addition, examples of the blowing agent include a physical blowing agent such as nitrogen (N ₂ ), carbon dioxide (CO ₂ ), freon, butane, pentane, neopentane, hexane, isohexane, heptane, isoheptane, methyl chloride, or azodicarbon Amide (azodicarbonamide) compound, p,p'-oxybis (benzenesulfonyl hydrazide) [p,p'-oxy bis (benzene sulfonyl hydrazide)] compound, N,N'-dinitrosopentamethylenetetra There is a chemical blowing agent such as an amine (N,N'-dinitroso pentamethylene tetramine)-based compound, and specifically, carbon dioxide (CO ₂ ) may be used in the present invention.

In addition, the extrusion performed in the present invention can be performed using various types of extruders. The foaming process can usually be carried out through bead foaming or extrusion foaming, but extrusion foaming is preferred in the present invention. Extrusion foaming continuously extrudes and foams a resin mixture, which simplifies the process step, enables mass production, and prevents cracks and granular breakage between beads during bead foaming, thus providing superior flexural strength and compression. Strength can be implemented.

Further, the polyester foam sheet used in the present invention may be heat treated at 150° C. to 300° C. for 10 seconds to 100 seconds before being used as the body and the bottom. Specifically, the polyester foam sheet is 150 ℃ to 250 ℃ or 180 ℃ to 220 ℃ 10 seconds to 70 seconds, 10 seconds to 60 seconds, 10 seconds to 30 seconds, 15 seconds to 25 seconds, 30 to 70 seconds, It may be a polyester foam sheet heat-treated for 30 to 50 seconds, or 50 to 70 seconds.

The present invention can improve the heat resistance of the foam sheet to 100° C. or more by heat-treating the polyester foam sheet at a temperature of 150° C. or higher for a certain period of time, and use the heat-treated polyester foam sheet as a material for the body and the bottom. Thus, it is possible to implement high insulation of the container. In this case, the "heat resistance" may mean a temperature at which the shape of the foam sheet is deformed by applying heat to the foam sheet.

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.

Example 1 to 6.

100 parts by weight of polyethylene terephthalate (PET) resin was dried at 130°C to remove moisture, and based on the PET resin from which the moisture was removed and 100 parts by weight of the PET resin from which the moisture was removed, pyromellitic deionhydra 1 part by weight of lead, 1 part by weight of talc, and 0.1 part by weight of Irganox (IRG 1010) were mixed and heated to 280° C. to prepare a resin melt. Then, 5 parts by weight of butane gas was added to the first extruder as a foaming agent based on 100 parts by weight of PET resin, and then extruded to produce a polyethylene terephthalate (PET) foam sheet. The cell density, crystallinity, and average thickness of the prepared foam sheet are shown in Table 1 below.

Then, the prepared polyethylene terephthalate (PET) foam sheet was heat-treated in a chamber at 200° C. for the time shown in Table 1 below, and the heat-treated foam sheet was fan-shaped (large arc: 22.2 cm, small arc: 15.7 cm, side surface). Length: 7.5 cm) and circles (diameter: 5 cm). After that, attach a low-melting polyester adhesive sheet to the outside of one end and the inside of the other end of the foam sheet cut into a fan shape with a thickness of about 5 mm, roll both ends to overlap, and apply heat of 130±2℃ to the body. made. Apply a low melting point polyester adhesive to the inside of the bottom of the body (small arc side) with a thickness of about 2±0.1 mm, push the previously cut circular foam sheet to place it, and apply heat at 130℃ to bond the bottom to the body. By doing so, a disposable cup-shaped container was manufactured. At this time, the side height (H) of the container is 7 cm, and the bottom surface diameter (D) is 5 cm (H/D=1.4).

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Cell density [Cell/㎠] 350 350 350 460 460 460 Average thickness [㎛] 1.5 1.5 1.5 One One One Crystallinity [%] 12 15 18 15 18 21 Heat treatment time [sec] 20 40 60 20 40 60 Body to bottom thickness ratio 1.0 1.0 1.0 1.0 1.0 1.0

Example 7.

A container was manufactured in the same manner as in Example 1, except that the side height (H) and the bottom surface diameter (D) of the container were adjusted to 7 cm and 5 cm (H/D=1.4), respectively.

Comparative example One.

A commercially available paper cup was purchased. At this time, the side height (H) and the bottom surface diameter (D) of the paper cup were the same as the container of Example 1, and the average thickness of the paper cup was 1±0.1 mm.

Comparative example 2.

A container was manufactured in the same manner as in Example 1, except that a polypropylene film (PP rigid film, average thickness: 0.7±0.05 mm) was purchased and used in the market instead of a polyethylene terephthalate (PET) foam sheet. .

At this time, the foam density of the polypropylene film was 900 cells/cm2, and the thickness ratio of the body and the bottom was 1.0.

Comparative example 3.

A polyethylene terephthalate (PET) foam sheet (cell density: 350 cells/cm 2, average thickness: 1.5 μm, crystallinity: 4%) under the same conditions as in Example 1 was prepared. Then, the prepared polyethylene terephthalate (PET) foam sheet was introduced into a press molding machine without heat treatment so that the surface temperature of the foam sheet was 160°C, and then the male mold (Plug) temperature was 60°C, and the female mold (Mold) was 120°C. Pressing at °C for 10 seconds to prepare a container. The H/D of the mold was 1.0, the depth of the receiving portion (H) was 10 cm, and the diameter of the opening (D) was 10 cm.

Comparative example 4 and 5.

The same method as in Example 1, except that the heat treatment of the polyethylene terephthalate (PET) foam sheet was not separately performed, and the ① cell density, ② average thickness, and ③ crystallinity of the foam sheet were adjusted as shown in Table 2 below. To prepare a container.

Comparative Example 4 Comparative Example 5 Cell density [Cell/㎠] 350 460 Average thickness [㎛] 1.5 One Crystallinity [%] 4 6 Heat treatment time [sec] 0 0 Body to bottom thickness ratio 1.0 1.0

Experimental example .

In order to confirm the thermal performance of the container according to the present invention, the following experiment was performed, and the results are shown in Table 3 below.

A) Insulation evaluation

In each of the containers prepared in Examples 1 to 6 and Comparative Examples 1 to 5, water at 100°C was contained so as to be 70% by volume of the container receiving portion, and left at room temperature (20°C) and atmospheric pressure (1 atm) for 3 minutes. Thereafter, the temperature of the water contained in the receiving portion and the temperature of the outer surface of the container body were measured, and the deviation of the measured temperature was calculated.

A) Heat resistance evaluation

For each container prepared in Examples 1 to 6 and Comparative Examples 1 to 5, the diameter and height of the top and bottom were measured, and the volume of each container was calculated from the measured diameter and height. Then, each container was allowed to stand in an oven at 100° C. for 3 minutes for heat treatment, cooled to room temperature again, and then the volume of the container was calculated in the same manner as described above, and the volume change rate of the container before and after the heat treatment was derived.

Heat treatment time of foam sheet Crystallinity Body and bottom
Thickness ratio Thermal insulation [℃] Heat resistance [%] Example 1 20 12 One 15 4 Example 2 40 15 One 15 3 Example 3 60 18 One 15 2 Example 4 20 15 One 10 3 Example 5 40 18 One 10 3 Example 6 60 21 One 10 One Comparative Example 1 0 0 One 5 3 Comparative Example 2 0 0 One 0 One Comparative Example 3 0 4 0.5 8 8 Comparative Example 4 0 6 One 15 10 Comparative Example 5 0 4 One 10 8

As shown in Table 3, it can be seen that the container according to the present invention has excellent thermal insulation properties and heat resistance.

Specifically, the containers prepared in the Examples contained water at 100°C and showed that the temperature of the outer surface of the container was 10°C or more different from the temperature of the water even after 3 minutes had elapsed. The containers manufactured in the manufactured comparative example showed a low temperature deviation of less than 10°C. This means that the heat shielding properties of the containers manufactured in the embodiment are excellent, so that the temperature difference between the inside and the outside of the container is maintained relatively large.

In addition, it was confirmed that the containers manufactured in the examples had a volume change rate of less than 5% even when left at a high temperature of 100°C. However, it was confirmed that the volume change rate of the containers of the comparative example manufactured using the foam sheet was 8% or more. This means that the containers of the embodiment are excellent in heat resistance, so that the shape of the container is hardly changed even when the temperature changes rapidly.

From these results, it can be seen that the containers according to the present invention have excellent heat resistance and/or heat insulation (ie, heat retention).

Claims (14)

Body comprising a polyester foam sheet; And
It is located at the lower end of the body and has a bottom portion including a polyester foam sheet,
The body and the bottom portion are joined to each other to form a sealed structure,
The ratio (H/D) of the side height (H) of the body and the diameter (D) of the bottom part is 0.7 or more,
The crystallinity of the polyester foam sheet is 10% to 30%,
Container containing 100℃ water and having a temperature difference of 10℃ or more between the outer surface of the body and the water inside after 3 minutes have passed.
The method of claim 1,
The container has a volume change rate of 5% or less after leaving it in an oven at 100°C for 3 minutes.
The method of claim 1,
A container, characterized in that the polyester foam sheet is a single foam sheet having an average thickness of 0.5 mm to 3 mm.
The method of claim 1,
A container having an average thickness ratio of 0.9 or more on the body and the bottom portion.
The method of claim 1,
A container with a side height (H) of 5cm to 20cm.
The method of claim 1,
The polyester foam sheet has an average cell density of 800 cells/㎠ to 25,000 cells/㎠.
The method of claim 1,
Polyester foam sheet is polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polyethylene A container containing at least one polyester resin selected from the group consisting of adipate (Polyehtylene adipate, PEA), polylactic acid (PLA), and polyglycolic acid (PGA).
The method of claim 1,
The container, characterized in that the container for beverages.
Pushing and inserting the bottom part including the polyester foam sheet to the inner bottom of the body including the polyester foam sheet; And
Including the step of manufacturing a container having a sealed structure by bonding the inserted bottom portion and the body,
The ratio (H/D) of the side height (H) of the body and the diameter (D) of the bottom part is 0.7 or more,
The crystallinity of the polyester foam sheet is 10% to 30%,
The manufactured container contains 100° C. water and after 3 minutes have elapsed, the temperature difference between the outer surface of the body and the inner water is 10° C. or more.
The method of claim 9,
The body and the bottom portion of the container manufacturing method comprising a polyester foam sheet heat-treated for 10 to 100 seconds at 150 ℃ to 300 ℃.
The method of claim 9,
The bonding of the body and the bottom is performed by any one or more of thermal fusion, ultrasonic bonding, adhesive, and adhesive sheet.
The method of claim 11,
The adhesive or adhesive sheet contains a low melting point polyester resin,
The low melting point polyester resin includes a repeating unit represented by the following Chemical Formulas 1 and 2, and a method of manufacturing a container having a softening point of 100°C to 130°C or a glass transition temperature of 50°C to 80°C:
[Formula 1]

[Formula 2]

In Formula 1 and Formula 2,
m and n represent the mole fraction of repeating units contained in the low melting point polyester resin,
Based on m+n=1, n is 0.05 to 0.5.
The method of claim 9,
Before the step of pushing the bottom of the body and inserting it,
Applying an adhesive containing a low-melting-point polyester resin or laminating an adhesive sheet on the inner bottom of the body; or
A method of manufacturing a container further comprising the step of applying an adhesive containing a low melting point polyester resin or laminating an adhesive sheet on the side of the bottom in the thickness direction.
The method of claim 9,
The step of bonding the bottom part to the bottom of the body is a method of manufacturing a container performed by applying a temperature of 100°C to 400°C.