JPS5873586A - Filling method into plastic vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Regarding the method of filling the contents into the plastic tS manufactured by the present invention, KW#L, < is easily deteriorated by oxygen molecules in the plastic container - reduces the change in the contents. The present invention relates to a method for filling the contents.

Polyester containers, especially polyester resins containing ethylene terephthalate repeating units
, transparency, hygiene, gas barrier properties.

In recent years, it has become popular as a beverage due to its excellent mechanical properties.

It is widely used as a container for food, cosmetics, secondary products, etc. However, such polyester containers generally do not have sufficient oxygen barrier properties, and when used as containers for contents that are susceptible to oxidative deterioration (for example, alcoholic beverages such as beer), there is a problem that the product life is short. There are some problems, and improvements are desired.

As a method to improve such drawbacks, polyvinyl alcohol;-
A multilayer composite of a resin with good oxygen barrier properties, such as polyester or vinylidene chloride, and a polyester resin (a method using a large container, etc. has been proposed).

However, this method has drawbacks such as complicated molding of the container, and the adhesive strength IIL between the resin layers is weak, resulting in peeling of the third layer, which seriously impairs the appearance.

The inventor of the present invention has conducted extensive studies on methods for preventing oxidative deterioration of the contents inside plastic containers, and as a result, after molding a polyester container, it is possible to remove the contents within a specified time. We found that the product lifespan of the axillary contents could be significantly extended by filling them, and we developed this IJ! Reach the circle.

That is, the present invention provides a method for filling a container made of a polyester resin containing ethylene terephthalate as a repeating unit with content 1111+, which is susceptible to deterioration by oxygen molecules, from the time the container is molded until the time the container is filled with the content. This method of filling a plastic container is characterized in that the time [1: days] satisfies the following formula.

t≦5oxt phosphoric acid is used to produce polyethylene terephthalate, which is obtained by reacting its lower al dFk ester with ethylene glycol. 7 Talendicarboxylic acid.

Aromatic dicarboxylic acids such as diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylsulfone dicarboxylic acid, etc.; Alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hext-hydroisoheptalytic acid, etc.; Adipic acid, cepatic acid.

one or more of aliphatic dicarboxylic acids such as azediic acid; p-β-hydroxyethoxyh7benzoic acid; other difunctional carboxylic acids such as acetic acid such as a-oxycaproic acid; and/ or part of the ethylene glycol component (usually 20
For example, triethylene glycol, tetramethylene glycol, and triethylene glycol.

Decamethylene dalycol, neopentyl glycol, diethylene glycol, triethylene glycol, Ll-
Dimethylol brings life to cyclo.

L4-cyclotosandimethylol, Kame 2-bis(4'
-β-Hydrodiphenyl)guanpan, bis(
It can also be substituted and copolymerized with one or more of polyfunctionalized metals such as 4'-β- and other glycols such as 4'-β-sulfonic acid and functional derivatives thereof.

Among these polyester resins, the most preferred is a polymer of polyethylene terephthalate, and the acid polyethylene terephthalate has an intrinsic viscosity of α5 or more, and more preferably Kq
It is preferable that it is 4 or more aso. In addition, the softening point of polyethylene terephthalate is 230℃ to 2?0℃.
．． C is preferred, and gso°C to zss°C is particularly preferred.
. It is preferred that other polyester resins also have the same physical properties as described above.

Examples of the plastic container of the present invention include containers obtained by a molding method involving stretching, such as bottles and pots. etc. are advantageously used, and the biaxial stretch blow molding method is particularly preferred.When molding a sand container by biaxial stretch blow molding, first the polyester is melted by heating to a temperature above the melting point in an injection molding machine. The resin is injected onto a metal preform and cooled to form a parison with a bottom.Then, the temperature of the varynon is adjusted to a range that allows the polyester resin to be stretched, and the resin is placed in a mold having the desired shape of the container. After this, it is stretched in multiple axial directions using a stretching rod, and a compressed fluid such as compressed air is blown into the container to expand it to the shape of a container. Containers obtained by biaxial stretch blow molding have excellent mechanical strength and heat shrinkage resistance, but during biaxial stretch blow molding, the temperature of the blow metal part must be high, for example, above the glass transition temperature. Moreover, a polyester container having even better heat shrinkage resistance can be obtained.

When the bottomed parison is stretched or expanded by blowing, the abrasive stretching magnification of the body of the bottle is at least 4 times, preferably at least 6 times, in terms of area magnification. Further, as a method for obtaining containers such as pots, methods such as air pressure forming and vacuum forming are applied.

In the present invention, the time from when the polyester container is molded to when it is filled with the contents must satisfy the following formula (1).

t≦5oxt” ・・・・・・ψ・・・・e(1)
[However, and t are the same as defined above] More preferably, the filling is performed within a time that satisfies the following formula ψ).

t≦26Xt” ・・・・・・・・・・・・Trust)
However, and t are the same as defined above] If the contents are filled within a time that satisfies the above formula, as is clear from the specific examples described later, oxidative deterioration of the contents can be significantly reduced, and the product life can be greatly extended. It can be stretched wide.

Average wall thickness of the container body in the above formula (t: m:)
Usually comes in a2~α8■.

In the present invention, contents that are susceptible to deterioration by oxygen molecules refer to those whose hue, taste, odor, etc. deteriorate due to oxidative deterioration.-1 For example, foods and beverages such as edible oil, fruit juice, and beer. can be mentioned.

The present invention will be described in detail below with reference to Examples.

e>, aKuma viscosity [Iv] can be measured in ms'c using O-chlorophenol as a solvent.

Examples 1-3 and Comparative Examples 1-2 IV-a? Dry the polyethylene terephthalate of s at 160℃ for 4 hours in a dehumidifying dryer until the moisture in the chip is 10
Obtained less than 1% dry chips. Using this dry step, 8
ounce injection molding machine (Taki Seisakusho M-100i1m)
And a set of hot runners, 2 pieces with a metal layer, straight body outer diameter 25M1, length 175mm, wall thickness 5mm and weight 5mm.
otr'? A D bottomed 1 ref form was molded. The molding conditions are cylinder set temperature 265-270℃ (resin temperature at nozzle 285℃), injection pressure 506-7004/-1 molding cycle aS seconds, gold layer cooling water temperature 10-20℃, injection molding machine cylinder. The residence time of the resin was approximately 2 minutes.

The nine preforms obtained were highly transparent, transparent, and substantially amorphous. The diameter of the upper part of the body is 75M1, and the height is
! @Om's commercially available oil bottle-shaped bottle is molded. The average wall thickness of this bottle body is α35
It was a meal.

The resulting bottle was kept at room temperature (approximately 20°C) for a period of III-IK.
) After storing the bottle, the inside of the bottle is sufficiently replaced with N and gas, and after 9 minutes, it is sealed, and stored in the atmosphere at 20°C.
The gas density was measured by gas chromatography.

The results are shown in Table IK.

Table 1 When the average wall thickness of the body is aSS-, it is necessary to fill the bottle within 6 days after bottle molding in the present invention, preferably within 3 days, but as is clear from Table 1 If the time is within 6 days after molding, the O□ gas concentration in the bottle at 40 days after filling will be as low as tl or less, whereas for bottles that have been molded for more than 10 days, the 0 gas concentration will be low at 40 days after filling. 2% or more), it can be seen that as a result, the contents are significantly altered by the false gas.

Examples 4 to 4 and Comparative Examples 3 to 4 Same as Example 1 except that the preform wall thickness was set to Low. 1tIt was made at 11K and the average wall thickness of the bottle body was α25-.
Shape the bottle into a circle. The resulting 9 bottles were stored at room temperature (approximately 20°C) for the period shown in Table 2. After 9 days, the bottles were filled with edible oil and the upper space was replaced with nitrogen and gas. It was stored at ℃ and the contents were examined for deterioration.

The results are shown in Table-2.

Table 2 * The odor of the contents is cool. O: There is not much of an odor. Δ: Slightly off odor: A strong odor. The odor is a burnt odor, etc.

Claims (1)

[Claims] A container made of polyester am containing ethylene terephthalate as a repeating unit is easily susceptible to deterioration by oxygen molecules.
A method for filling a plastic container, characterized in that the time [t: days] from the time to filling the contents satisfies the following formula. ! ≦5oxt”