Synthetic resin container with window, preform, and method of injection molding preform

Abstract

A synthetic resin container or bottle with a window obtained by subjecting a test tube-shaped preform made by injection molding to biaxial stretch blow molding is provided. The container includes a transparent base layer; a circumferential wall formed of the transparent base layer; and a light-blocking or opaque intermediate layer formed in the base layer in a laminated manner to cover an area of a predetermined height of the circumferential wall. The intermediate layer is formed in a laminated manner over an area covering an entire circumference of the circumferential wall excluding a non-laminated section, where the intermediate layer is not formed, that extends in a shape of a longitudinal strip along the central axis direction of the container on the circumferential wall of the container. The non-laminated section serves as a window section.

Description

TECHNICAL FIELD[0001]The disclosure relates to a synthetic resin container with a window made by biaxial stretch blow molding, which has a transparent or semitransparent window section through which residual quantity of contents can be observed from outside. The disclosure also relates to a test tube-shaped preform being a precursor of the container and a method of injection molding the preform.BACKGROUND[0002]Blow molded containers made of synthetic resin have been conventionally used primarily for containing, for example, beverages, food, detergents, cosmetics, and medicine. They are in many cases given a light-blocking property to protect the contents from ultraviolet rays or the like, or configured such that the contents thereof becomes invisible to improve the appearance and design qualities.[0003]Giving a light-blocking property or making the contents invisible from outside has been achieved for example by making the container itself opaque using a colored resin, by coating th...

AI Technical Summary

Benefits of technology

[0049]The features of the disclosed products and methods have been described above, and they provide the following advantageous effects.

[0050]The disclosed preform has a circumferential wall with a laminated structure obtained by forming an opaque intermediate layer in a transparent base layer in a laminated manner. More specifically, the laminated structure is composed of the base layer, the intermediate layer, and the base layer arranged in this order from outside to inside. A non-laminated section, where the intermediate layer is not formed, that extends in a shape of a longitudinal strip is also provided. This transparent non-laminated section serves as a longitudinal strip-shaped window section of the container made by biaxial stretch blow molding. With these features, a colored resin will not be mixed into a portion of a transparent window section to spoil the appearance of the window section, or a part of the window section will not be made opaque. It becomes thus possible to provide a container made by biaxial stretch blow molding which has a transparent, clear window section.

[0051]In the disclosed products, the intermediate layer is formed in the base layer in a laminated layer to provide a laminated structure of sandwich arrangement. This prevents the contents from directly contacting the intermediate layer in which pigment or filler is dispersed. Therefore, the problems such as quality change or the like in the contents can be also overcome.

Problems solved by technology

However, when the contents are made invisible from outside as above, the residual quantity of the contents cannot be observed from outside, causing inconvenience and uneasiness in use.

In particular, when refilling the container with contents, the filling state is invisible so that the contents may be poured too much to be spilled out.

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