JP2006341891A - Container made of polyethylene terephthalate and its preform - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease a residual amount of hydrogen peroxide when a container made of polyethylene terephthalate or its preform is sterilized with hydrogen peroxide. <P>SOLUTION: The container formed of polyethylene terephthalate manufactured by using an antimony catalyst or its preform is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a container made of polyethylene terephthalate and a preform thereof, and more particularly to a container made of polyethylene terephthalate with a very small amount of residual germicide and a preform thereof.

  Recently, polyethylene terephthalate containers such as PET bottles (hereinafter referred to as PET containers) have been widely used as containers for various foods and beverages. Generally, a PET container is manufactured by injection-molding polyethylene terephthalate, or is manufactured by subjecting a preformed product obtained by injection-molding polyethylene terephthalate to stretching such as blow molding. And when packaging food and drink in a PET container, after sterilizing the inner surface and outer surface of the PET container, the contents are packaged or filled. As a method for sterilizing the inner and outer surfaces of the container, a method using an aqueous solution of hydrogen peroxide is widely used. For example, normal or heated aqueous hydrogen peroxide solution is sprayed on the inner and outer surfaces of the container, or the container is dipped in the aqueous hydrogen peroxide solution and then hot air is blown to dry the container.

  When the PET container is sterilized with hydrogen peroxide or other sterilizing agent, some sterilizing agent remains in the container. Although the residual amount of the disinfectant is controlled to a safe level, it is desirable that it is as small as possible.

  An object of the present invention is to provide a PET container and its preform that can reduce the residual amount of hydrogen peroxide when the PET container or its preform is sterilized with hydrogen peroxide.

  In order to achieve the above object, the present invention provides a polyethylene terephthalate container formed of polyethylene terephthalate produced using an antimony catalyst and sterilized with hydrogen peroxide, and a preform thereof. provide.

  The present invention also includes esterifying terephthalic acid or an ester-forming derivative thereof with ethylene glycol or an ester-forming derivative thereof and using the resulting ester compound as a main component, and using the ester compound as a polycondensation catalyst with an antimony catalyst. Disclosed is a polyethylene terephthalate container formed of polyethylene terephthalate produced by condensation and sterilized with hydrogen peroxide, and a preform thereof.

  When hydrogen peroxide is brought into contact with polyethylene terephthalate produced using an antimony catalyst, compared with the case where hydrogen peroxide is brought into contact with polyethylene terephthalate produced using another catalyst (eg, a germanium catalyst). The residual amount of hydrogen peroxide can be extremely reduced.

  In the present invention, polyethylene terephthalate produced using an antimony catalyst is used as a material for the PET container and its preform.

  The antimony-based catalyst for producing polyethylene terephthalate refers to those mainly composed of antimony trioxide and antimony pentoxide, and in particular, those mainly composed of antimony trioxide. In addition, trace amounts of sodium and iron oxides are contained depending on the degree of purification of antimony trioxide obtained by firing antimony ore.

  When hydrogen peroxide is brought into contact with polyethylene terephthalate produced using an antimony catalyst, the remaining amount of hydrogen peroxide is small because the antimony catalyst has a large amount of catalyst residue as a metal compound and a single metal. And antimony has a strong reducing ability. Therefore, it is presumed that the metal antimony present as a catalyst residue reduces the residual amount by reducing and decomposing hydrogen peroxide.

  Further, if a large amount of sodium and iron oxides are contained, it is not preferable because precipitation of metal antimony is suppressed and the reducibility is lowered. The initial content of these oxides is preferably 20 ppm or less in terms of the total amount of atoms.

  In order to sterilize a container formed of polyethylene terephthalate manufactured using an antimony catalyst with hydrogen peroxide, a conventionally known method can be employed. For example, a hydrogen peroxide aqueous solution may be sprayed on the inner and outer surfaces of the container, or the container may be dipped in a hydrogen peroxide aqueous solution and dried. A preform formed with polyethylene terephthalate produced using an antimony catalyst may be sterilized with hydrogen peroxide after being converted into a container by stretching such as blow molding, or during the stage of the preform. After sterilization with hydrogen peroxide, the film may be stretched and converted into a container while maintaining aseptic conditions, and then packaged or filled.

  Next, the present invention will be described more specifically with reference to examples and comparative examples.

(Example 1)
A PET bottle with an internal volume of 500 ml was molded from polyethylene terephthalate (manufactured by Shinko Gosei Co., Ltd .: SHINPET 5015W) produced using an antimony catalyst. Mist of hydrogen peroxide solution (H ₂ O ₂ ) as a sterilizing agent was sprayed from a nozzle to sterilize the inner and outer surfaces of this PET bottle.

After 24 hours from sealing the sterilized PET bottle, hydrogen peroxide (H ₂ O ₂ ) is extracted by immersing it in 9 ml of pure water, and the amount of hydrogen peroxide extracted is peroxidized using an oxygen electrode. hydrogen was measured with _{(H 2 O} 2) concentration measuring device.

(Example 2)
A PET bottle having an internal volume of 500 ml was molded in the same manner as in Example 1 with polyethylene terephthalate (manufactured by SK CHEMICAL: PB7755) manufactured using an antimony catalyst. This PET bottle was sterilized with hydrogen peroxide in the same manner as in Example 1. After 24 hours had passed after the sterilized PET bottle was sealed, the amount of hydrogen peroxide extracted was measured in the same manner as in Example 1.

(Comparative Example 1)
A PET bottle having an internal volume of 500 ml was formed of polyethylene terephthalate (manufactured by Mitsui Chemicals: J125) manufactured using a germanium catalyst. This PET bottle was sterilized with hydrogen peroxide in the same manner as in Example 1. After 24 hours had passed after the sterilized PET bottle was sealed, the amount of hydrogen peroxide extracted was measured in the same manner as in Example 1.

(result)
The results of each experimental example are shown in Table 1.

表１は、アンチモン系触媒を用いて製造したポリエチレンテレフタレートで形成したＰＥＴボトル（実施例１，２）と、ゲルマニウム系触媒を用いて製造したポリエチレンテレフタレートで形成したＰＥＴボトル（比較例１）を過酸化水素で殺菌した時の、各ボトルの過酸化水素の残留量を示す表である。

Table 1 shows PET bottles (Examples 1 and 2) formed with polyethylene terephthalate manufactured using an antimony catalyst and PET bottles (Comparative Example 1) formed with polyethylene terephthalate manufactured using a germanium catalyst. It is a table | surface which shows the residual amount of the hydrogen peroxide of each bottle when it sterilizes with hydrogen oxide.

  As is apparent from this table, the amount of hydrogen peroxide remaining in the bottles of Examples 1 and 2 was very small compared to the amount of hydrogen peroxide remaining in the bottle of Comparative Example 1.

Claims (4)

  A polyethylene terephthalate container formed of polyethylene terephthalate produced using an antimony catalyst and sterilized with hydrogen peroxide.   A polyethylene terephthalate container preform formed of polyethylene terephthalate manufactured using an antimony catalyst and sterilized with hydrogen peroxide.   It was produced by esterifying terephthalic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative, and using the resulting ester compound as a main component and polycondensing this ester compound using an antimony catalyst as a polycondensation catalyst. A polyethylene terephthalate container formed of polyethylene terephthalate and sterilized with hydrogen peroxide.   It was produced by esterifying terephthalic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative, and using the resulting ester compound as a main component and polycondensing this ester compound using an antimony catalyst as a polycondensation catalyst. A preform for a polyethylene terephthalate container made of polyethylene terephthalate and sterilized with hydrogen peroxide.