JPS58112949A - Multilayer vessel and its manufacture - 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 The present invention relates to a multilayer container for cosmetics, etc., which requires functionality for the contents to be filled and aesthetic appearance as added value, and a method for manufacturing the same.

A multilayer container as used in the present invention is a synthetic resin container in which an outer layer is double molded to an inner layer, and these are compositely molded by stretch blow molding, and the mouth of the inner layer is transparent and the body is It is a container with a multilayer structure, which has a long cord and a cloudy white color, and has multiple layers of colored and transparent outer layers on a given outer surface of the body.

The purpose of this is to:
111 functionality on the vehicle head, the transparent mouth of the inner layer body, the body of a cloudy white color, and the multi-layered outer layer body that becomes colored and transparent can create a three-color decorative effect, and at the same time, it is possible to create a three-color decorative effect. The colored transparent outer layer can be seen through the body of the colored inner layer to reveal a novel exterior beauty with a profound color sense.

Recently, 1. As a molding material for synthetic resin containers, the material has outstanding characteristics such as mechanical strength due to mechanical properties, scum permeation resistance, chemical resistance, maintainability, hygienic property, and glossiness. has attracted attention, and thermoplastic polyester resins mainly composed of polyethylene terephthalate have been widely used. The physical property of this thermoplastic polyester resin, which is mainly composed of polyethylene terephthalate, is that it becomes transparent when an injection molded article, such as a bottomed parison, is rapidly cooled immediately after molding.

Alternatively, it is known that if the surface of a material that has been rapidly cooled to become transparent is reheated at a high temperature, a whitening phenomenon due to crystallization will occur and a white color will appear. The high temperature (surface temperature) in this case is defined as 70°C to 200°C, which is between the glass transition point and the crystallization temperature.

Therefore, the present invention aims to study the above characteristics of polyester resin material, use the resin material for the inner layer of the container, and utilize its physical properties to manufacture a container with the above structure. , the gist of the manufacturing method is to injection mold a bottomed parison of thermoplastic polyester resin mainly composed of napolyethylene terephthalate on the inner layer surface, to rapidly cool the entire parison to make it transparent, and to make the parison transparent. A colored transparent molded resin layer serving as an outer layer is double molded on the cylindrical body part excluding the eye part of the parison, and
A step of reheating the cylindrical body portion with the heat of the resin material during the injection of the outer layer body molding resin to cause a whitening phenomenon due to crystallization to produce a solid white color with a length of cord, and an intermediate double layer in the step. The method is characterized in that it is manufactured by a step of expanding a molded article into a desired container shape by stretch blow molding.

Next, the present invention will be specifically explained based on illustrated embodiments.

First, regarding the drawings, Figure 1 is a cross-sectional view of the product container, and Figure 2 is a cross-sectional view of the product container.
The figure shows the molded state of the bottomed parison, Figure 3 shows the state in which the helison shown in the previous figure is rapidly cooled, and Figure 4 shows the double molding of a colored transparent outer layer molding resin layer on the cylindrical body of the parison. Fig. 5 shows the state in which the intermediate double molded product shown in the previous figure has been set in a blow mold, and Fig. 6 shows the state in which it has been stretch blow molded. , inner layer body,
! L: It has a multi-layered structure in which the outer layer C is multi-layered on the torso b2 excluding the mouth b1, the mouth b1 of the inner layer is transparent, the chest b2 is a permanently cloudy white color, and the outer layer body C is transparent and colored in Shido color.

Therefore, regarding the manufacturing method of this, firstly, a mouth mold 1.1 that becomes a split mold, and a core 2 that is fixedly installed through this mold.
The tees 3 are clamped together in the die P, which will become a punching die, and a thermoplastic polyester resin mainly composed of polyethylene terephthalate (hereinafter referred to as polyester resin), which will become the inner layer of product A, is injected and prepared. A bottomed Rison P as a molded product is molded.

This parison P has an eye part P1 which becomes the mouth part b+ of the required product A (generally has a screw for screwing the beef dip).
At this point, the cylindrical body part P which becomes the body part b2 of product A is molded by the mold 1.1 which becomes the split mold.
2 is molded by core 2 and +digital 3.

Next, add the injection molded bottomed type Rison P to +r heat 3.
The entire parison is made completely transparent by rapid cooling using a cooling device as appropriate.

Then, the eye portion P1 of the parison P is clamped to the double molding element 4 while the core 2 is inserted into the same molding die 1.1.

The cylindrical body portion P2 of the parison thus formed and the +↑same tee 4. ! : A colored and transparent outer layer molding resin layer W, which is the same or different from the A parison, is injected into the open cavity to perform double molding on the outer surface of the parison.

This double-molded colored and transparent resin layer W becomes the outer layer C of the product, and is injected only onto the cylindrical body portion P2 of the parison located inside the cow ↑ tee 4. Since it is multi-layered, the relevant part of Ballin is reheated by the heat of the melted resin material during injection of the resin layer, which causes a whitening phenomenon due to crystallization, resulting in an everlasting cloudy white color. It will appear in

According to experiments conducted by the inventors, a polyester resin parison with a wall thickness of 2.5 mm and a bottom was molded at an injection temperature of 250° C., and this was rapidly cooled to a glass transition point of 7 α C.

When a polyester resin of the same quality as the parison is used for the outer layer molding resin layer during two-time molding, and this is injection molded to a thickness of 3.0 mm at a high temperature of 250°C, the surface temperature of the parison is 110°. C, which is also a foreign material.

For example, when injection molding is performed using As (acrylic nitrile styrene) resin to produce meat [3.0 trrn], the material temperature is 200°C, but the surface temperature of the parison is 9σc4, which is the temperature that promotes crystallization and causes the whitening phenomenon. was extremely good.

By reheating the parison to a temperature above the crystallization temperature and below the melting temperature using the colored and transparent outer layer molding resin layer during double molding in which the parison is multi-layered as described above.

The cylindrical body portion P2 of the parison P can be made cloudy. Since the eye part Pi remains transparent due to the rapid cooling in the previous step, after it is made into the product described below, it can not only bring about the decorative effect of three colors, but also the effect on the use as a container, i.e., the content. Mono helmet iJ1g! This is convenient for checking the remaining amount or color of the contents, and for this purpose, it is made transparent separately from the cylindrical body.

At the same time, the intermediate double molded product molded as above is +
At the same time as breaking away from Dijiti 4, extracting Core 2 and 1
While the eye portion P1 is held in the same mold 1゜1 as described above, the cylindrical body portion P2 is placed into a blow mold 7 which becomes a split mold having a molding cavity 8 of the same shape as the external shape of the chest b2 of the desired product A. After inserting and clamping the mold, a stretched mold 6 is tightly fitted inside the eye part P1, and a stretched mold 5 having a blowing nozzle connected to a source of pressurized fluid is fitted into this support mold. It is inserted into the body portion Pl by penetrating it so as to be slidable up and down. In this case, the double molded product is maintained at a temperature that allows stretch blow molding.

Using a well-known stretching method, the body part is stretched by protruding the stretching point P2, and at the same time, a pressurized fluid such as air is blown into the mold surface of the blow mold 7 while reducing the wall thickness of the cylindrical body part P2. Product A is obtained by inflating until they are in close contact and blow-molding the body part b2 into the cavity 8.

In the product A molded in this way, only the mouth part of the inner layer body is transparent, and the body part b2 is a cloudy whitish color. It has a three-color decorative effect, and has a dignified and elegant appearance, and is strong due to the polyester resin used as the inner layer molding material.

It has functionality suitable for filling cosmetics, etc., since it exhibits scum permeation resistance, chemical resistance, fragrance retention, etc.

Although the present invention is not shown, the molding machine used in the present invention continuously performs injection molding of a bottomed parison, rapid cooling, double molding, stretch blow molding, and product removal using an integrated pot. For example, a molding machine with a rotary mechanism is used, and the eye part is held in place by the same mold from the molding of the parison to the production of the product. There is no damage to the mouth part as a result of this, and when it has a thread, a product with high thread precision can be obtained.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of a product container. FIG. 2 is a sectional view showing the state of injection molding of the bottomed parison. Figure 3 is a cross-sectional view showing the state in which the helison ← ← ← shown in the previous figure is rapidly cooled. FIG. 4 is a sectional view showing a state in which a colored and transparent outer layer molding resin layer is double-molded on the cylindrical body portion of the parison, and the body portion is made cloudy by reheating. FIG. 5 is a cross-sectional view of the intermediate double-molded product in the previous step, which has been put into a plow mold and a stretching tube inserted. FIG. 6 is a sectional view of a product container manufactured by stretch blow molding. [Signs] A... Product b... Inner layer body bl... Mouth part bl... Body C... Outer 1 integrated P... Bottomed parison Pl... ... Eye part P2 ... Cylindrical body part W ... Colored and transparent outer layer body molding resin layer 1 ...
・ Eye mold 2 ... Core 3 ... +i'ji tee 4 ... Double molded cow Vji tee 5 ... Stretch 0 6 ... Stretch 0 F" Home 7...
8... Forming sky music Figure 4 Figure 5m Figure 3 Figure 6

Claims (1)

[Claims] ■ A multilayer container characterized by a structure in which the mouth of the inner layer is transparent, the chest is cloudy and cloudy, and the outer surface of only the chest is colored and transparent. . ■ The inner layer is made of a thermoplastic polyester resin mainly composed of polyethylene terephthalate, and the outer layer is multilayered with a colored and transparent resin that is the same or different from the inner layer. The multilayer container described in section 1). ■ The inner layer is mainly made of polyethylene terephthalate.
A step of injection molding three bottomed litons made of thermoplastic polyester resin. rapidly cooling the entire parison to make it transparent; A colored and transparent molded resin layer is double-molded as an outer layer on the cylindrical body part excluding the eyes of the transparent parison, and the cylindrical body part is coated with the resin material at the time of injection of the outer layer body molding resin. A step of generating a whitening phenomenon due to crystallization by reheating with heat to develop a cloudy white color. A step of expanding the intermediate double molded product in the above step into a desired container shape by stretch blow molding. A method for manufacturing a multilayer container, characterized in that it is manufactured by: