KR100391972B1 - A polyester type airtight receptacle - Google Patents

Abstract

The present invention relates to a polyester-based airtight container consisting of a body and a lid, wherein the container body is composed of a polyester-based resin in which 1 to 50 mol% of polyethylene naphthalate and 50 to 99 mol% of polyethylene terephthalate are copolymerized. It is characterized by having.

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<Properties of Container Body>

Heat deformation temperature: 65 ~ 95 ℃ Transparency: 85% or more

Oxygen transmittance: 1.5 to 6.5 (cc / 100 inch ² days atm)

UV blocking: 320 ~ 385nm

The airtight container of the present invention is particularly useful as a kimchi storage container because of its excellent oxygen barrier property, oil resistance and pollution resistance.

Description

Polyester hermetic container {A polyester type airtight receptacle}

The present invention relates to a polyester-based airtight container excellent in oxygen barrier properties, oil resistance and pollution resistance. The airtight container consists of a container body and a container lid, and is mainly used for storing and storing foods such as seasonings, drinks, and kimchi.

In the case of closed containers for storing food, especially the closed containers for storing kimchi, excellent oxygen barrier properties are required to prevent ripening or deterioration of the stored food, and to facilitate cleaning and to prevent contamination (coloring) in repeated use. Excellent oil and fouling resistance are also required.

Conventionally, a hermetic container manufactured by melt-injecting a polypropylene resin and a hermetic container manufactured by melt-injecting a polycarbonate resin has been mainly used. However, in the case of the polypropylene sealed container, the oxygen barrier property is low, so that a large amount of gas penetrates from the inside of the container to the outside. In addition, there is a problem that the stain resistance is difficult to wash, the container is colored by seasoning, etc. when repeated use, the appearance is bad.

On the other hand, in the case of the polycarbonate sealed container, the oxygen barrier property and the pollution resistance are relatively good, but the oil resistance is poor, so that transparency and impact strength are lowered by cooking oil or the like when used. Furthermore, it is known that bisphenol-A, an environmental hormone-like substance, is emitted when processed in a microwave oven, which also causes health problems.

An object of the present invention is to provide a polyester-based airtight container excellent in oxygen barrier properties, oil resistance and fouling resistance to solve the problems of the conventional airtight container.

An object of the present invention is to provide a sealed container for storing kimchi, which is excellent in oxygen barrier property, oil resistance and pollution resistance, and has good transparency and moldability.

The polyester-based hermetically sealed container of the present invention for achieving the above object is composed of a polyester-based resin in which the container body is copolymerized with 1 to 50 mol% of polyethylene naphthalate and 50 to 99 mol% of polyethylene terephthalate. It is characterized by having.

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<Properties of Container Body>

Heat deformation temperature: 65 ~ 95 ℃ Transparency: 85% or more

Oxygen transmittance: 1.5 to 6.5 (cc / 100 inch ² days atm)

UV blocking: 320 ~ 385nm

Hereinafter, the present invention will be described in detail.

First, the closed container of the present invention is composed of a separately injection molded container body and the container lid. The container body is manufactured by melting and injecting a polyester resin copolymerized with 1 to 50 mol% of polyethylene naphthalate and 50 to 99 mol% of polyethylene terephthalate in an injection machine. The copolymerized polyester crab resin is prepared by copolymerizing a glycol component of ethylene glycol and an acid component consisting of 1 to 50 mol% of naphthalenedicarboxylic acid and 50 to 99 mol% of terephthalic acid.

When the content of polyethylene naphthalate in the copolyester-based resin is less than 1 mol%, the crystallization rate of the resin is high, resulting in poor moldability and lower transparency. On the other hand, when the polyethylene naphthalate content in the copolymerized polyester resin exceeds 50 mol%, the manufacturing cost increases, which is uneconomical.

Since the container body has an oxygen permeability of 1.5 to 6.5 cc / 100 inch ² · atm, it can prevent the odor from being discharged from the food being stored, and also prevent the food from being deteriorated.

In addition, the container body can easily check the state of the food being stored at more than 85% transparency, that is, without opening the lid, it is convenient. In addition, the heat deformation temperature is 65 ~ 95 ℃, it can block the ultraviolet rays of 320 ~ 385nm wavelength can prevent food deterioration in storage. Hereinafter, it is represented by the ultraviolet wavelength range which can block the ultraviolet ray blocking property.

The container body of the present invention has a high degree of crystallinity of the resin and oil, coloring pigments, dirt, etc. are not easily adsorbed into the resin. As a result, oil resistance and contamination resistance are very excellent.

Meanwhile, the lid of the airtight container of the present invention is manufactured by melt-injecting a polyolefin-based resin having a different type from the resin forming the body on both the lid surface and the sealed portion in an injection machine, or the lid surface is a polyester-based resin and the sealed portion is polyester-based. Elastomer resins or polyolefin resins are prepared by melt double injection in an injection molding machine.

The reason for the different types of resin constituting the lid and the body of the sealed container as described above is to facilitate the opening and closing of the lid more easily.

In the present invention, various physical properties of the sealed container were evaluated by the following method.

Oxygen transmittance

After preparing a 2㎛ film using a resin, it was measured by the ASTM D 3985 method using a Mocon Oxtran (Mocon Oxtran) 2 / MH equipment.

Haze change

Samples were taken from the sealed container and measured by ASTM D 1003 method using a haze meter (manufactured by Nippon Denshoku Co., Ltd.).

Heat deflection temperature

It was measured by ASTM D 648 (4.6kg / ㎠) method.

UV blocking

It was measured by UV-VIS spectrometer (manufactured by Hewlett Packard).

Bisphenol-A detection

Fluorescence detectors were used for the 5965-9043 E method of Hewlett-Packard Company.

Oil and fouling resistance

After storing kimchi for one week in an airtight container and washing it 10 times, the sensory test of 10 experts was evaluated. [8 or more judged to be excellent: ○, 5 to 7 judged to be excellent: △, 4 or fewer judged to be excellent: ×]

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

Example 1

A polyester resin is prepared by copolymerizing ethylene glycol with an acid component consisting of 15 mol% of naphthalenedicarboxylic acid and 85 mol% of terephthalic acid. Melting and injecting the polyester resin to prepare a body of the sealed container. Meanwhile, the polyolefin resin is melt-injected to produce a lid surface and a lid sealing portion of a sealed container. The results of evaluating various physical properties of the container thus prepared are shown in Table 2.

Example 2-Example 3

A sealed container in the same process and conditions as in Example 1 except that the composition of the polyester resin constituting the body of Example 1 and the type of the resin constituting the lid surface and the sealing portion of the lid are changed as shown in Table 1. To prepare. The results of evaluating various physical properties of the sealed container thus prepared are shown in Table 2.

Airtight Container Manufacturing Conditions division Body resin composition (mol%) Lid Resin Type Polyethylene naphthalate Polyethylene terephthalate Lid Seal Example 1 5 95 Polyolefin resin Polyolefin resin Example 2 8 92 Polyester resin Polyester elastomer Example 3 40 60 Polyester resin Polyolefin resin

Comparative Example 1

Except that the body of the airtight container is made of polyolefin resin, the airtight container is manufactured by the same process and conditions as in Example 1. The results of evaluating various physical properties of the sealed container thus prepared are shown in Table 2.

Comparative Example 2

A sealed container is manufactured in the same process and conditions as in Example 1 except that the body of the sealed container is made of polycarbonate resin. The results of evaluating various physical properties of the sealed container thus prepared are shown in Table 2.

Airtight container property evaluation result division transparency(%) Oxygen permeability (cc-mil / 100 inchi ² · 24hr · atm) UV protection (nm) Heat deflection temperature (℃) Oil resistance Pollution resistance Example 1 87 5.6 370 75 ○ ○ Example 2 88 4.5 375 78 ○ ○ Example 3 85 2.2 380 90 ○ ○ Comparative Example 1 75 150 280 110 × × Comparative Example 2 85 6.1 280 146 × △

The present invention has excellent oxygen barrier properties, there is no odor caused by the food stored, and effectively prevents the deterioration of the contents. In addition, the present invention is excellent in oil resistance and stain resistance, easy to wash, and prevents coloring to have a good appearance. In particular, the present invention is transparent and easy to see the state of the contents without opening the lid, the moldability is also good.

Claims (3)

In a sealed container consisting of a body and a lid, the container body is composed of a polyester-based resin copolymerized from 1 to 50 mol% polyethylene naphthalate and 50 to 99 mol% polyethylene terephthalate has the following physical properties, the container lid (Iii) a polyolefin resin, (ii) a polyester resin and a polyolefin resin, or (iii) a polyester resin and a polyelastomer resin. -Below- <Properties of Container Body> Heat deformation temperature: 65 ~ 95 ℃ Transparency: 85% or more Oxygen transmittance: 1.5 to 6.5 (cc / 100 inch ² days atm) UV blocking: 320 ~ 385nm The polyester closed container according to claim 1, wherein the intrinsic viscosity of the polyester resin is 0.65 to 1.0 dl / g. delete