JPS5976228A - Formation of synthetic resin tubular vessel - Google Patents

Abstract

PURPOSE:To easily manufacture the titled vessel excellent in characteristic as a gas barrier, by activating the inner surface of a shoulder part, spray coating the inner surface with curing resin paint excellent in characteristic as a gas barrier, and then curing the coating film. CONSTITUTION:A synthetic resin head part 3 formed by vertically providing a mouth tube 3 at the upper end of a truncated conical tubular shoulder part 2 is inserted into the upper end of a body 5 constituted by winding a film obtd. by laminating a synthetic resin sheet with an aluminum foil into a cylindrical shape, to form the main body 1 of the vessel. The inner surface of the shoulder part 2 of the main body 1 of the vessel is treated into corona discharge or the like, a thin metal tube A, e.g. aluminum, having an outer diameter approximately equal to the inner diameter of the body 5 is inserted into the body 5 to coat the inner surface of the body 5, and only the exposed inner surface of the shoulder part 2 is spray coated with paint for forming a cured film by a spray coater B. Thereafter, said paint is cured by baking-drying or ultraviolet irradiation, to form a coating film 6 on the inner surface of the shoulder part 2. Hence, the tubular vessel abound in characteristic as a gas barrier including the body 5 is easily obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a synthetic resin tube container, and an object of the present invention is to easily obtain a container with excellent gas barrier properties.

When it comes to synthetic resin tube containers, an important issue is how to maintain the quality of the contents without changing the quality of the contents.In order to prevent deterioration and improve fragrance retention, aluminum foil is coated and laminated. Efforts have been made to improve gas barrier properties.

By the way, as is well known, a synthetic resin tube container is produced by injection molding or saracha one-way molding, etc., by forming a synthetic resin head body with a spout on the upper end of a truncated conical shoulder and forming the upper end of the body using a synthetic resin film. It is relatively easy to create a laminated structure in which the synthetic resin film that makes up the fuselage is coated with synthetic resin sheets on both sides of aluminum foil, for example, to ensure gas barrier properties. You can also do that.

However, it is extremely difficult to create a laminated structure for the shoulders of the head, so we have considered preparing a truncated cone-shaped aluminum foil molded product or a thermosetting resin molded product in advance and integrating them through insert molding. However, all of them have drawbacks such as being labor-intensive and expensive to mold, and having incomplete continuous parts and poor gas barrier properties.

The present invention relates to a method for molding a synthetic resin tube container developed to eliminate the above-mentioned conventional drawbacks and inconveniences.The present invention relates to a method for molding a synthetic resin tube container, which has been developed to eliminate the above-mentioned conventional drawbacks and inconveniences. This method involves spray coating a curable resin paint and then curing the formed coating film.

An embodiment of the present invention will be described below with reference to the drawings.

First, the container body l has a shoulder part 2 in the shape of a truncated conical cylinder, and a spout 3 at the upper end.
A synthetic resin head body 3 with an upright structure is insert-molded onto the upper end of a body 5 which is constructed by winding a film made of laminated synthetic resin sheets and aluminum foil into a cylindrical shape.

The inner surface of the shoulder portion 2 of the container body 1 is subjected to surface activation treatment such as corona discharge treatment or gas flame treatment, and then a thin metal cylinder A made of aluminum or iron having an outer diameter approximately equal to the inner diameter of the body 5 is attached to the body 5. The inner surface of the body 5 is coated, and then only the exposed inner surface of the shoulder portion 2 is spray-coated with a cured film-forming paint using a spray device B.

This spray device B has a special shape in which a plurality of injection holes are bored at the tip of an elongated tube, so that uniform spray coating can be achieved from the entire inner surface of the shoulder portion 2 to the inner surface of the spout 3.

The coating material for forming a cured film is an epoxy resin or a modified epoxy resin such as urea, phenol, or acrylic, a thermosetting resin coating such as a polyurethane resin, or an ultraviolet curable coating. The case also has excellent gas barrier properties, and since the inner surface of the shoulder portion 2 is subjected to surface activation treatment, the adhesion strength of the coating film is extremely high.

The thermosetting resin coating adhered to the inner surface of the shoulder 2 in this way is cured by baking (d) or if it is an ultraviolet curable paint coating, it is cured by irradiation with an ultraviolet lamp, and then the inner surface of the shoulder 2 is cured. A coating 6 is formed.

Since this coating 6 has been hardened as described above, the body 5
If it adheres to the body 5, it will interfere with its use as a tube container that crushes and pushes out the contents.
As described above, the metal tube A is inserted into the body 5 to mask the inner surface so that the metal tube A is not spray coated.

As is clear from the above explanation, the molding method of the present invention
For a normal container body 1 with a head 4 inserted into the upper end of the body 5, a coating 6 with excellent gas barrier properties is simply sprayed onto the inner surface of the shoulder 2 of the head 4 and cured to form a coating 6! , and the gas barrier including the fuselage 5 is sufficient.
It has many excellent functions, such as being extremely easy to obtain a tube container with excellent quality retention ability and fragrance retention, and is inexpensive since no aluminum foil or the like is used for the head body 4. have an effect.

[Brief explanation of drawings]

The drawing is a sectional view of a container showing one embodiment of the present invention. Explanation of symbols 1: Container body 2: Shoulder 3: Mouth tube 4: Head 5: Body 6: Coating A: Metal cylinder B Nispray device. 128

Claims (1)

[Claims] A surface active treatment is applied to the inner surface of the shoulder of the container body, which is made by insert-molding a synthetic resin head with a truncated cone-shaped shoulder and a spout on the upper end of the body, which is made by winding a laminated film into a cylindrical shape. After applying, the inner surface of the shoulder is spray-coated with a cured film-forming paint such as a thermosetting resin paint such as a modified epoxy resin or a polyurethane resin, or an ultraviolet curable paint, and then the paint film is cured to form a film. 1. A method for forming a synthetic resin tube container.