JPH05228988A - Multilayer stretch blow container and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a polyester stretch blow container with excellent design whose gas barriers and odors are bettered by providing a drug such as oxygen absorbing agent or materials for the use of decoration between an inner layer and an outer layer of the stretch blow container consisting of thermoplastic polyester at least at the inner and outer layers. CONSTITUTION:Preforms 1 and 2 made of thermoplastic polyester resin such as polyethyleneterephthalate as a principal component is manufactured. The preform 2 is a size smaller than the preform 1 and these are superposed so as to make a multilayer preform 3. At this time, one kind or more of drugs such as oxygen absorbing material and deodorant, air, and materials for the use of decoration is provide. This multilayer preform 3 is treated with stretch blow molding so as to form a container. Thus, oxygen permeability and acetaldehyde density can be reduced, and heat retaining containers and containers with decorations can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method in which two or more types of preforms are superposed, and a chemical such as an oxygen absorbent and a deodorant, a substance for decoration, air, etc. are applied between the preforms, and stretch blow is performed. The present invention relates to a method for producing a stretch blow container for obtaining a blow container and the container.

[0002]

2. Description of the Related Art Conventionally, polyester containers made by stretch blow molding, particularly polyethylene terephthalate containers, have excellent physical properties (lightness, transparency, moderate rigidity, etc.) due to their excellent properties such as carbonated beverages and seasonings. It is widely used as a container for foods, cosmetics, liquid detergents, etc.

However, the stretched polyester container has a gas permeability that cannot be ignored, and therefore has insufficient gas barrier properties as a container for contents, carbonated drinks and the like that are easily deteriorated by oxygen. As a means for improving gas barrier properties, other resins having excellent gas barrier properties, for example, saponified ethylene-vinyl acetate copolymer, aromatic polyamide resin, or the like, are used in a laminated structure having at least one layer or blended with polyester. A method of forming a composite container such as is known.

Further, in a stretched polyester container, acetaldehyde and the like generated by resin decomposition during molding remain in the resin, and the odor of acetaldehyde and the like may be a problem when used as a container. As a method of reducing acetaldehyde generated during molding, a method of lowering the molding temperature during molding, a method of changing the mixing ratio of ethylene glycol and terephthalic acid during polymerization of a polyethylene terephthalate resin, and the like are known.

As described above, the stretched polyester container has an insufficient gas barrier property and has a problem of odor such as acetaldehyde generated during molding. Means for improving each of them are known, but no satisfactory optimum method has been obtained. Further, there has been no simple method for allowing a decorative substance, air, or the like to exist between the layers of a multilayer stretched polyester blow container.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to a multi-layer stretch blow container and / or a multi-layer stretch blow container in which a decorative substance, air, or the like is provided between layers, in which the gas barrier property and the odor problem generated during molding are prevented. An object is to provide a container and a manufacturing method thereof.

[0007]

In order to solve the above problems, the present invention provides a thermoplastic polyester resin such as a polyethylene terephthalate resin which is stretched in at least two layers, the inner surface and the outer surface. A multi-layer stretch blow container provided with a part or all of chemicals such as an oxygen absorbent, a deodorant, a substance for decoration, air, etc., or a thermoplastic resin such as polyethylene terephthalate resin. Two or more preforms composed mainly of polyester resin are stacked, and one or several kinds of chemicals such as oxygen absorbers and deodorants, decorative substances, air, etc. are applied between the preforms, and one preform is used. Provided is a method for producing a stretch blow container, which comprises forming a preform and subjecting the multiple preform to stretch blow molding.

A detailed description will be given with reference to the drawings. FIG. 1 shows cross-sectional views of two types of preforms 1 and 2 before being superposed. FIG. 2 is a cross-sectional explanatory diagram of the preforms of FIG. At this time, between the two preforms, an oxygen absorber,
A chemical such as a deodorant, a decorative substance, air, or the like can be provided alone or in combination. FIG. 2 shows a case where an oxygen absorbent is applied in between. FIG. 3 is a cross-sectional explanatory view of the container 4 manufactured by performing stretch blow molding using the multilayer parison of FIG.

Between the preforms, in addition to agents such as an oxygen absorbent and a deodorant, a decorative substance, for example, a thin film of the same material as the preform, which is printed, can be provided. In addition, by combining the preforms so that a space such as air can enter between the preforms, a container having a heat retaining property can be obtained.

[0010]

As described above, by stacking two or more preforms to form a multiple preform, a chemical such as an oxygen absorbent is provided between the preforms when the multiple preform is formed, and stretch blow molding is performed. However, by obtaining the stretch-blown container, it becomes possible to use a chemical that cannot be used because it decomposes at the resin melting temperature, and problems such as gas barrier properties and odor are solved.

Further, by using the stretch blow molding, the decomposition temperature of the chemical agent to be used may be a stretching temperature (polyethylene terephthalate resin; 90 ° C.) or more at the time of stretch blow molding the multiple preforms. Up to the melting temperature (polyethylene terephthalate resin; 260 ° C.) is sufficient even without heat resistance. Therefore, the range of use of the drug is expanded.

Further, the substance to be provided between the multiple preforms is not limited to the drug, but may be any substance which does not decompose at the stretching temperature or less, and a substance for decoration, air or the like can be used to keep the contents warm, A decorative container and a heat insulating container can be easily obtained.

[0013]

【Example】

<Example 1> A preform 1 (weight 16 g) made of a thermoplastic polyester mainly composed of a polyethylene terephthalate resin (intrinsic viscosity IV = 0.70), and a preform 2 which is slightly smaller than the preform 1 and overlaps with the preform 1. (Weight: 17 g), each manufactured by injection molding. When these preforms 1 and 2 are overlaid to form a multiplex preform 3, 1 g of an oxygen absorbent (organic acid oxygen absorber) is applied between the preforms, and the multiplex preform is reheated (preform temperature 95 ° C.) Then, stretch-blow molding is performed, and container 4 (capacity 500 ml, surface magnification 4.71 times,
A surface area of 0.047 m ² and a wall thickness of 0.55 mm) was obtained. The results of measuring oxygen permeability using the container using the Mocon method are shown in (Table 1). As Comparative Example 1, a container was obtained in the same manner as in Example 1 except that the oxygen absorbent was not applied.

[0014]

[Table 1]

As shown in the above (Table 1), the container of Example 1 provided with the oxygen absorbent has a lower oxygen permeability than the container of Comparative Example 1 not provided with the oxygen absorbent.

<Example 2> In Example 1, when the preforms 1 and 2 were overlaid, 1.5 g of a deodorant (activated carbon) was applied to form a multiple preform, and stretch blow molding was performed to obtain the container 4
Got The results of measuring the acetaldehyde concentration using the container are shown in (Table 2). The acetaldehyde concentration was measured 30 minutes after the molding, by purging the inside of the container with nitrogen, plugging the cap, and 1 day after the molding, by gas chromatography. Further, as Comparative Example 2, a container was obtained in the same manner as in Example 2 except that the deodorant was not applied.

[0017]

[Table 2]

As shown in the above (Table 2), the container of Example 2 to which the deodorant was applied was the same as Comparative Example 2 in which the deodorant was not applied.
The acetaldehyde concentration is lower than that of the container.

<Example 3> In Example 1, when the preforms 1 and 2 were overlaid, a metal film having a thickness of 1 to 10 μm and a length and width of about 0.5 mm was vapor-deposited or colored polyester film was used in an appropriate amount. Was subjected to stretch blow molding to obtain a container 4. The obtained container had a glittering side surface and was excellent in decorativeness. The decorative substance is not particularly limited and may be appropriately selected.

<Fourth Embodiment> In the first embodiment, when the preforms 1 and 2 are overlapped with each other, the preform 2 is preliminarily formed in a shape such that the outer side surface is shaved, and a space is formed when the preforms are overlapped to form a multiplex mold. Reformation and stretch blow molding while performing air suction from the inner surface of the mold to obtain a container 4 having an air layer therebetween.

[0021]

EFFECT OF THE INVENTION Since the stretch blow container of the present invention is provided with chemicals such as an oxygen absorbent and a deodorant, a substance for decoration, air and the like in the intermediate layer, it compensates for the defects of polyester and is excellent in decorativeness. Also, it can be used as a heat insulation container.

Further, according to the method for producing a stretch-blown container of the present invention, since it does not have heat resistance (about 100 ° C. or higher), it becomes possible to use chemicals which could not be mixed in the container, and the function of the polyester container is achieved. Can be easily modified by drugs.

[0023]

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of two types of preforms before they are superposed.

FIG. 2 is a cross-sectional view illustrating a situation in which two types of preforms of FIG. 1 are superposed and a drug is applied between the preforms.

3 is a cross-sectional explanatory view of a bottle formed by stretch blow molding using the multiple preform of FIG.

[Explanation of symbols]

1 ... Preform 2 ... Preform 3 ... Multiple preform 4 ... Stretch blow bottle

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Claims (2)

[Claims] 1. A thermoplastic polyester resin such as a polyethylene terephthalate resin is present by stretching at least two layers on an inner surface and an outer surface, and is partially present between the inner surface and the outer surface.
Alternatively, a multi-layer stretch blow container characterized in that one or more kinds of chemicals such as oxygen absorbent, deodorant, decorative substance, air, etc. are provided on the entire surface. 2. A preform composed mainly of a thermoplastic polyester resin such as a polyethylene terephthalate resin is overlaid, and a chemical such as an oxygen absorbent, a deodorant, a decorative substance, air or the like is placed between the preforms. A method for producing a stretch-blown container, which comprises applying one kind or a combination of several kinds to give one multiple preform, and stretch-blowing the multiple preform.