JP2011156737A - Synthetic resin-made bottle and method of molding the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To create a molding method which effectively suppresses the deformation of a bottle body by a molted resin in a synthetic resin-made bottle and a method of molding the same where a transparent outer shell is injection-molded by using the bottle body to be a blow molded article as an insert material. <P>SOLUTION: In the method of molding the bottle, a cylindrical bottomed transparent synthetic resin-made outer shell is injection-molded by using the bottle body as the insert material. The molten resin forming the outer shell is filled with a measuring and filling method in such a state that a cooling air is circulated and supplied to the bottle body, the pressure increase in a pressure holding step is avoided by employing the measuring and filling method, the temperature rise of the bottle body is suppressed by the cooling air, and the pressure increase of the molten resin due to the molten resin flowage is suppressed by thickening the wall of the outer shell. The degree of the cooling by the cooling air and the thickening of the wall of the outer shell is set to such a degree that the deformation in the bottle body does not occur by the molten resin pressure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a synthetic resin bottle formed by using an insert molding technique and a method for forming the bottle.

  As a double-walled synthetic resin bottle, at least the outer shell constituting the outer layer is made transparent so that an excellent optical decoration can be obtained. An insert molding technique is known in which a part or the whole of the bottle main body constituting the material is used as an insert material, and an outer shell body is molded by injection molding.

  In general, in insert molding, a bottle body serving as an insert material is held immovably by a mold so that the pressure applied during molding of the outer shell can be stably received.

  For example, as shown in Patent Document 1, a bottle body is fixedly attached to a split mold as an insert material, and a cavity formed between the insert material and the split mold is communicated with a gate to insert the insert material. Cooling water is circulated and supplied to cool the insert material, and in this state, molten resin is injected from the gate into the cavity to form an outer shell body integrally with the insert material.

Thus, in the technique disclosed in the conventional example, since the insert material cannot be supported from the inside by the mold, the liquid is used in order to prevent the bottle body as the insert material from being deformed by the injection molding pressure of the outer shell body. In the insert material, the injection pressure is supported by the pressure of the liquid, and the insert material made of synthetic resin is cooled.

JP-A-49-083751

  However, when filling the insert material with a liquid and molding it, the liquid must be supplied to and discharged from the insert material each time it is molded, and the liquid adhering to the product must be wiped off or the product dried. There was a problem that it took time and effort.

In addition, when molding a double-walled synthetic resin bottle by insert molding, a blow molded bottle is often used as the insert material, but the molded product by blow molding is thicker than the injection molded product. Spots and residual distortion increase, and there is a problem that thermal deformation tends to occur when high temperature molten resin comes into contact with insert molding.
Furthermore, the surface of the bottle body used as an insert material is laminated with a decorative layer such as a printed layer, a paint film layer, or a metal vapor deposition film layer, so that the optical decoration effect by the transparent outer shell body can be further enhanced. In this case, however, cracks and wrinkles are likely to occur in the decorative layer due to slight deformation of the insert material, and the cracks and wrinkles are visible through the transparent outer shell, and the decorativeness is greatly impaired. Therefore, it is necessary to suppress the deformation of the insert material due to the molten resin pressure to a higher degree.

The present invention relates to a synthetic resin bottle in which a transparent outer shell body is injection-molded using a bottle body which is a blow molded product as an insert material and a molding method thereof, and uses a cooling means by air instead of a liquid while melting. The objective is to create a molding method that effectively suppresses the deformation of the bottle body caused by resin, and a synthetic resin bottle that is decorated in a variety of high quality, including the lamination of decorative layers, with a transparent outer shell. It is intended to provide.

  The present invention relates to a synthetic resin bottle and a method for molding the same. Hereinafter, a method for molding a synthetic resin bottle, and then a synthetic resin bottle will be described.

The main method relating to the method of molding the synthetic resin bottle of the present invention is as follows:
A synthetic resin bottle that is a synthetic resin blow molding housing is used as an insert material, and a synthetic resin bottle with a bottomed cylindrical transparent synthetic resin that covers the body and bottom of the bottle body is injection molded. In the molding method,
In the state where the cooling air is circulated and supplied into the bottle body set in the injection mold, the molten resin forming the outer shell body is filled by the metering filling method.
By adopting the metering filling method, avoiding the pressure rise related to the pressure holding process,
The temperature rise of the bottle body is suppressed by cooling air, and the increase in the molten resin pressure related to the flow of the molten resin is suppressed by increasing the thickness of the peripheral wall of the outer shell body,
The degree of cooling by the cooling air and the increase in the thickness of the peripheral wall of the outer shell are set to such an extent that the bottle body is not deformed by the molten resin pressure.

According to the above method, since the bottle body which is an insert material is cooled by circulatingly supplying cooling air instead of the conventional liquid, the molded product does not get wet, and the mold apparatus does not get wet, Further, since it is not necessary to replace the air that is the cooling medium for each molding, the productivity can be achieved at a high level.
Also, the method of the above configuration is to deform the bottle body due to the molten resin pressure during insert molding, (1) cooling the bottle body with cooling air, (2) adopting the metering filling method, (3) the peripheral wall of the outer shell body The three means of increasing the thickness are to be suppressed in combination, and each means exhibits the following operational effects.

(1) Cooling of the bottle body with cooling air The cooling air can suppress the temperature rise of the bottle body due to the molten resin, and preferably the temperature rise is below the glass transition point of the synthetic resin used in the bottle body. By suppressing, the deformation | transformation by the molten resin in a high temperature and a high pressure state can be suppressed effectively.
Further, by blowing cooling air intensively on a portion of the bottle body that is particularly prone to deformation, such as a position facing the gate opening, deformation of the portion can be more effectively suppressed.

(2) About the metering and filling method The metering and filling method is a method in which a predetermined amount of molten resin is filled in the mold cavity so that there is no insufficient filling of the mold cavity, and the pressure-holding step is omitted. It is possible to avoid a large pressure increase according to the above, and to suppress the deformation of the bottle body due to this pressure.

(3) Thickening of the outer wall of the outer shell body The outer wall of the outer shell body is thickened, that is, the cavity formed by the outer peripheral surface of the bottle body as an insert material and the cavity mold is widened, and the gate port is opened. Thus, the flow path of the molten resin injected into the cavity can be increased, and the flow resistance can be decreased to effectively suppress the increase in the molten resin pressure.

The combined effects of the means (1), (2), and (3) can effectively suppress the deformation of the bottle body.
Among them, the temperature rise of the bottle body can be suppressed by cooling with cooling air, but there is a limit to sufficiently supporting the injection molding pressure so as to fill the liquid from the inside with cooling air,
Cooling with cooling air suppresses the rise in the temperature of the bottle body and suppresses the rise in the molten resin pressure by increasing the thickness of the outer wall of the outer shell, thereby cooling the outer wall with the cooling air and the thickness of the outer wall of the outer shell. By adjusting the conditions of both means of meatization, taking into account the productivity and design constraints, the degree of cooling by cooling air and the thickening of the outer wall of the outer shell body can be controlled by the molten resin pressure. It can be set to such an extent that the main body is not deformed.
Note that, for example, the portion facing the gate opening may be slightly deformed because high-temperature high-pressure molten resin collides with it, but deformation that is not visible from the outside through the transparent outer shell is allowed.
Here, the synthetic resin bottle according to the present invention is an outer layer of a bottle body with a transparent synthetic resin outer shell. In the present invention, "transparent" means a translucent or colored transparent one. Shall be included.

Another method according to the molding method of the present invention is the above main method,
Using an injection mold with a gate opening located opposite the center of the bottom bottom of the bottle body,
The bottle body has a wall thickness of at least 0.8 mm;
The shape of the mold cavity is set so that the bottom of the outer shell and the peripheral wall of the cylindrical portion have a thickness of at least 3 mm.

The above method uses an injection mold in which a gate port is arranged opposite to the central part of the bottom bottom surface of the bottle body, and this gate port is arranged in the molding of this kind of bottle by insert molding. It is standard, and the molten resin injected from the gate port flows at a high temperature so as to collide with the central portion of the bottom bottom surface of the bottle body, and further flows along the peripheral wall of the body portion to the upper end thereof.
Here, in the case of blow-molded products, the bottom bottom surface is formed relatively thick, but the lower end portion of the body portion, that is, the peripheral wall immediately above the bottom portion is often formed thin, and the molten resin is formed on the bottom bottom surface. Although the peripheral wall may be crushed and deformed just above the bottom due to the pressure caused by the collision and flow from the bottom to the peripheral wall, the bottle body should have a wall thickness of at least 0.8 mm. Can prevent this kind of extreme deformation.

  And by setting the shape of the mold cavity so that the outer wall of the outer shell and the peripheral wall of the cylindrical part have a thickness of at least 3 mm, the flow resistance of the molten resin is reduced and the rise of the molten resin pressure is suppressed. In addition, it is possible to effectively prevent more minute deformation seen in the vicinity of the bottom of the bottle body, particularly including the peripheral wall immediately above the bottom (hereinafter simply referred to as the vicinity of the bottom).

Still another method according to the molding method of the present invention is the main method,
It is assumed that the decorative layer is laminated on a predetermined area on the outer peripheral surface of the bottle body, and the degree of cooling by cooling air and the thickening of the peripheral wall of the outer shell body are cracked in the decorative layer by the molten resin pressure. It is said that the setting is made so as not to cause wrinkles.

The above structure uses an insert material in which a decorative layer such as a printed layer, a paint film layer or a metal vapor deposition film layer is laminated on a predetermined area on the outer peripheral surface of the bottle body, and the deformation of the bottle body is further enhanced. Need to be suppressed,
By setting the degree of cooling with cooling air and the thickening of the outer wall of the outer shell to such an extent that cracks and wrinkles do not occur in the decorative layer due to the molten resin pressure,
The decoration effect by a decoration layer and a transparent outer shell can be exhibited more highly.

Still another method according to the molding method of the present invention is an injection mold in which a gate port is disposed so as to face the center of the bottom bottom surface of the bottle body in the molding method related to the bottle body in which the decorative layer is laminated. Use
The bottle body has a wall thickness of at least 0.8 mm;
The shape of the mold cavity is set so that the outer shell has a thickness of at least 4 mm at the bottom and at least 3 mm of the peripheral wall of the cylindrical portion.

When the decorative layer is laminated on the bottle body, it is necessary to suppress the deformation of the bottle body to a higher degree as described above. However, the bottom of the outer shell body has a thickness of at least 4 mm so that the mold cavity has a thickness of at least 4 mm. By setting the shape, it is possible to sufficiently suppress an increase in the molten resin pressure in the vicinity of the bottom, and to effectively prevent the occurrence of cracks and wrinkles in the decorative layer.
In addition, when a decoration layer is a layer which is easy to thermally deform, such as a metal vapor deposition film layer, it is preferable that the bottom part of an outer shell shall have a thickness of at least 5 mm.

Still another method according to the molding method of the present invention is a method of disposing a gate port so as to be opposed to the central portion of the bottom bottom surface of the bottle body.
It is said that cooling air is supplied from near the bottom in the bottle body.

  According to the above method, by supplying cooling air from the vicinity of the bottom facing the gate opening in the bottle main body, the injected molten resin collides, and the vicinity of the bottom exposed to the most severe conditions, The cooling action of cooling air can be made to act reliably.

  Still another method according to the molding method of the present invention is a method in which the gate port is disposed so as to be opposed to the center of the bottom bottom surface of the bottle body, and the tip of the air pin for supplying cooling air is applied to the bottom of the bottle body. It is said to make contact.

  According to the above method, the tip of the air pin that supplies the cooling air is brought into contact with the bottom of the bottle body, so that the bottom of the bottle body to which the injection pressure of the injected molten resin directly acts is mechanically supported by the air pin. be able to.

  Next, although the structure of this invention which concerns on a synthetic resin bottle is demonstrated, these bottles can be shape | molded with the shaping | molding method mentioned above.

The main structure of the present invention relating to a synthetic resin bottle is:
A bottle body that is a synthetic resin blow housing with a continuous mouth tube portion;
Made by injection molding with this bottle body as an insert material and a gate part at a position facing the bottom of the bottle body, made of transparent synthetic resin with a bottomed cylinder that covers the body and bottom of the bottle body The outer shell body,
The bottle body shall have a wall thickness of at least 0.8 mm;
The peripheral wall of the bottom part and the cylindrical part of the outer shell body has a thickness of at least 3 mm.

According to the above configuration, the bottle body has a wall thickness of at least 0.8 mm, and the peripheral wall of the bottom portion and the cylindrical portion of the outer shell body has a wall thickness of at least 3 mm. As explained in the molding method, the outer shell body can be formed from the injection molding without deforming the bottle body as an insert material,
It is possible to provide a synthetic resin bottle that exhibits a high-quality optical decoration effect by a thick and transparent outer shell.

Here, the shape of the bottle body by blow molding can use various shapes such as a round shape such as a cylindrical shape, a square tube shape, a polygonal tube shape, etc. Can also be round, square tube, polygonal tube, etc., by combining the shape of the bottle body and the outer shell body, for example, using a transparent outer shell body, Various optical decoration effects such as crystal-like optical effects can be achieved by combining rectangular cylindrical outer shells.
The bottle body can be opaque or transparent depending on the purpose.

  The other configuration relating to the synthetic resin bottle is the above main configuration, wherein the insert material is formed by laminating a decorative layer in a region including at least the vicinity of the bottom of the outer peripheral surface of the bottle body, and the bottom of the outer shell is at least 4 mm. It is said that it is set as the structure which has thickness.

According to the above configuration, the bottom of the outer shell body is made thicker and has a thickness of at least 4 mm, so that the molten resin injected from the gate port collides during the injection molding of the outer shell body. The deformation near the bottom of the bottle body can be suppressed to a higher degree, and the outer shell body can be formed without generating cracks and wrinkles in the decorative layer.
The optical decoration effect by a decoration layer and a transparent outer shell can be exhibited highly.
In addition, when a decoration layer is a layer which is easy to thermally deform, such as a metal vapor deposition film layer, it is preferable that the bottom part of an outer shell shall have a thickness of at least 5 mm.

Here, a decoration layer can also be laminated | stacked over substantially whole area | region from the mouth tube part of a bottle main body to a bottom part, and can also be laminated | stacked partially.
Furthermore, the bottle body is transparent, the formation area and the non-formation area of the decorative layer are alternately arranged in a stripe pattern, a pattern having regularity is formed as a whole, and a moire pattern appears. An optical decoration effect can also be exhibited.

  Still another configuration relating to the synthetic resin bottle is that, in the main configuration described above, the decorative layer is at least one layer selected from a printing layer, a coating film layer, or a metal vapor deposition film layer.

A decoration layer is not limited to 1 type, According to the purpose of decoration, a different kind of decoration layer can also be laminated | stacked.

Since the present invention has the above-described method and configuration, the following effects can be obtained.
That is, the synthetic resin bottle molding method of the present invention combines the three means of cooling the bottle body with cooling air, adopting a metering filling method, and increasing the thickness of the peripheral wall of the outer shell body, and injecting the outer shell body. In molding, it is intended to suppress deformation of the bottle body due to molten resin pressure,
Although there is a limit to sufficiently supporting the injection molding pressure from the inside of the bottle body with the cooling air, the rise of the temperature of the bottle body is suppressed by cooling with the cooling air, and it is melted by increasing the peripheral wall of the outer shell body By controlling the rise of the resin pressure, the conditions of both means of cooling by the cooling air and thickening of the peripheral wall of the outer shell body can be adjusted to each other while taking into consideration the constraints of productivity and design The degree of cooling by the cooling air and the thickening of the peripheral wall of the outer shell can be set to such an extent that the bottle body is not deformed by the molten resin pressure.

In addition, even when a decorative layer is laminated on the bottle body, by adjusting and setting the conditions of both means of cooling with cooling air and thickening the peripheral wall of the outer shell, The degree of thickening of the peripheral wall of the shell can be set to such an extent that cracks and wrinkles are not generated in the decorative layer by the molten resin pressure while satisfying productivity and bottle shape.

It is a whole perspective view which shows 1st Example of the synthetic resin bottles of this invention. (A) of the bottle of FIG. 1 is a half longitudinal cross-sectional view, (b) is a bottom view. It is a top view of the bottle of FIG. (A) of the bottle main body used for the bottle of FIG. 1 is a front view, (b) is a bottom view. It is a metal mold | die block diagram before shaping | molding used for description of the shaping | molding method of this invention. It is a metal mold | die structure figure after a shaping | molding used for description of the shaping | molding method of this invention. It is a whole perspective view which shows 2nd Example of the synthetic resin bottles of this invention. (A) of the bottle of FIG. 7 is a half longitudinal cross-sectional view, (b) is a bottom view.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 4 show a first embodiment of a synthetic resin bottle of the present invention (hereinafter simply referred to as a bottle), FIG. 1 is an overall perspective view, and FIG. (B) is a bottom view, FIG. 3 is a plan view, and FIG. 4 is a front view and (b) is a bottom view of a bottle body 11 used in the bottle 1 of FIG.
The bottle 1 has a cylindrical mouth tube portion 2, a shoulder portion 3, a cylindrical body portion 4, and a bottom portion 5. From the bottle main body 11 and a transparent and thick outer shell body 21 that covers the bottle main body 11. The casing is configured with a total height of 93 mm, a body diameter of 37 mm, and a capacity of about 30 ml.

The bottle body 11 is a biaxially stretched blow-molded product made of polyethylene terephthalate (PET) resin, and a mouth tube portion 12 that becomes the mouth tube portion 2 of the bottle 1 is erected on the upper end of a cylindrical body portion 14 via a shoulder portion 13. It is a housing having an overall height of 87 mm and a body diameter of 28 mm.
Moreover, although the average thickness from the trunk | drum 14 of this bottle main body 11 to the bottom part 15 is 1.6 mm, there exists a thin part of 0.9 mm in the lower end part (just above the bottom part 15) of the trunk | drum 14. As shown in FIG.
In this embodiment, the shape of the bottom 15 of the bottle main body 11 is a wall structure in which the bottom wall is curved inward, but the shape of the bottom wall is not limited and is flat or outward. It is also possible to form a hemispherical arc shell by bulging into a curved shape.

  In this embodiment, for the purpose of enhancing the decoration effect, the vacuum evaporation method or the sputtering method is applied to the entire region from the shoulder portion 13 to the bottom portion 15 of the bottle main body 11 as shown in the longitudinal section of FIG. The decorative layer 18a made of a metal vapor-deposited film layer is laminated together with the decorative layer 18b made of a printed layer on the decorative layer 18a. "Is designed and expressed.

The outer shell body 21 is a bottomed cylindrical body made of a transparent resin and made up of a cylindrical portion 24 and a bottom portion 25. The bottle body 11 is used as an insert material, and an injection having a configuration as shown in FIG. It is formed by being set in a mold, and externally covers a portion from the body portion 14 to the bottom portion 15 of the bottle body 11.
Further, a gate mark 27 is seen at the center of the bottom 25 of the outer shell 21 as shown in FIG.

The outer peripheral shape of the cylindrical portion 24 of the outer shell body 21 is a regular dodecagon as shown in the plan view of FIG. 3, and the inner peripheral shape is circular along the trunk portion 14 of the bottle body 11.
Moreover, the thickness of the peripheral wall of the cylindrical part 24 is 4-5 mm, and the thickness of the bottom part 25 is 6 mm at the thin part.
Examples of the transparent synthetic resin include acrylic resin and styrene-based transparent resin. In this embodiment, the resin body is excellent in compatibility with the bottle body 11 made of PET resin, moldability, mechanical strength, and chemical resistance. Therefore, a polyester resin-based transparent resin such as PCTA or PCTG was used.
Of course, the synthetic resin material used for the bottle body 11 and the outer shell body 21 is not limited, and a resin material that can exhibit required characteristics including moldability can be freely selected and used. Needless to say, you can.

In the above resin, the PCTG resin is a dicarboxylic acid component mainly composed of terephthalic acid (TA), 50 to 80 mol% of 1,4 cyclohexanedimethanol (CHDM), and 20 to 50 mol% of ethylene glycol (EG). PCTA resin is a dicarboxylic acid component mainly composed of terephthalic acid (TA) and isophthalic acid (IPA), and 1,4 cyclohexanedimethanoldiol (CHDM). Is a resin composed of a diol component mainly composed of
Eastman Chemical Co., Ltd. EastarAN014 can be used as the PCTA resin, and Eastman Chemical Co. EastarDN011 can be used as the PCTG resin.

  And in the bottle 1 of a present Example, the outer periphery shape of the outer shell 21 is formed by the optical effect by the metal surface of the thick and transparent outer shell 21 and the decoration layer 18a which consists of a metal vapor deposition film layer. Combined with the shape and effect of the regular dodecagonal shape, the ridgeline of the outer shell body 21 is reflected on the decorative layer 18a and becomes multi-layered, so that a decorative effect that shines brightly appears.

In addition, the letters “abcde” by the decorative layer 18 laminated on the decorative layer 18a are floated on the surface having the metallic luster of the decorative layer 18a by the optical action of the outer shell body 21. It will be visible, and a deep decoration effect will appear.
Here, such a decoration effect is achieved by making the bottle body 1 transparent, making the body of the bottle body a polygonal shape, making the metal vapor-deposited film layer semi-permeable, etc. By combining the body or the decorative layer, it can be exhibited in various modes. Of course, it can also be set as the structure without a decoration layer.

Next, the shaping | molding method of this invention is demonstrated, referring FIGS. 5 and 6 along the shaping | molding method of the bottle 1 of the said Example.
5 and 6 are diagrams for explaining an example of the configuration of an injection mold 31 for insert-molding the bottle 1 and an example of a molding procedure for the bottle 1. FIG. 5 is a diagram of a mold before molding, and FIG. 6 is a mold after molding. FIG.

As shown in FIG. 5, the injection mold 31 mainly includes a bottle main body holding portion 32 and a cavity mold 33, and the bottle main body 11 fixes its mouth tube portion 12 with the bottle body holding portion 32. The cavity 34 is set in the cavity mold 33, the bottle body 11 is used as a core material, and the outer shell body 21 is formed by filling the cavity mold 33 with molten resin. Yes.
A gate port 37 is disposed at a position facing the bottom 15 of the bottle body 11 of the cavity mold 33 so as to communicate with the cavity 34.

In addition, an air pin 36 is inserted in the hanging bottle body 11, and the air pin 36 abuts the tip of the air pin 36 against the bottom portion 15 of the bottle body 11, and opens an outlet for cooling air a at the tip. I am letting.
And cooling air a is circulated and supplied to the bottle main body 11 through the air pin 36, but this cooling air a may use the air cooled by the cooler, or more than the molten resin to be injected. Room temperature air having a low temperature may be used.

As shown in FIG. 5, with the bottle body 11 set in the cavity mold 33, the synthetic resin forming the outer shell body 21, in this embodiment, the PCTG or PCTA resin is melted and the gate port 37 is melted. To the cavity 34.
At this time, the molten resin flows so as to collide with the bottom portion 15 of the bottle main body 11 as indicated by the white arrow shown in FIG. 5, wraps around the peripheral wall of the barrel portion 14, and then the barrel portion 15 along the peripheral wall. The outer shell body 21 is molded as shown in FIG. 6.

Here, according to the flow behavior of the molten resin as described above, normally, the heat and injection pressure of the injected high-temperature molten resin act directly on the vicinity of the bottom portion 15 of the bottle body 11, and the vicinity of the bottom portion 15 In such a case, it will be greatly crushed.
In addition, even in a small crushed deformation, wrinkles are generated along with the deformation on the outer surface in the vicinity of the bottom 15, so that the wrinkles appear through the transparent outer shell body 21 in the formed bottle 1, The original decorating properties will be impaired.
Further, when a decorative layer is laminated on the bottle body 11 as in the bottle 1 of FIGS. 1 and 2, it is necessary to prevent the occurrence of cracks and wrinkles in the decorative layer, and it is necessary to highly suppress deformation. is there.

  In this respect, in the molding method of the present invention, the deformation near the bottom 15 is (1) cooling the bottle main body 11 with the cooling air a, (2) adopting the metering filling method, and (3) the bottom 25 of the outer shell 21. The three means of increasing the wall thickness including the surrounding wall are suppressed together.

  First, by cooling the bottle main body 11 with the cooling air a, the vicinity of the bottom 16 is efficiently cooled by blowing out the cooling air a from the tip of the air pin 36 contacting the bottom 16 as shown in FIG. And the temperature rise of the said part can be suppressed effectively and the fall of the deformation strength with respect to the injection pressure accompanying the temperature rise can be suppressed.

  5 and 6, the bottom 15 is mechanically supported by bringing the tip of the air pin 36 into contact with the bottom 15 of the bottle body 11, so that the bottom 15 is caused by the injection pressure of the molten resin. It is possible to suppress deformation into a depressed state.

  Next, in the metering and filling method, the cavity 34 is filled with a predetermined amount of molten resin in accordance with the volume of the cavity 34, and the pressure-holding step is omitted. It is possible to avoid a large pressure increase due to.

Next, the increase in the thickness of the peripheral wall of the outer shell 21 is intended to widen the cavity 34 to widen the flow path of the molten resin and reduce the flow resistance to suppress an increase in the molten resin pressure.
In the bottle 1 shown in FIGS. 1 and 2, the thickness of the peripheral wall of the cylindrical portion 24 of the outer shell 21 is 4 to 5 mm, and the thickness of the bottom portion 25 is 6 mm at the thin portion. Considering that the bottom 15 of the bottle body 11 as an insert material is exposed to the most severe conditions due to the collision of the injected molten resin, and that the decorative layer 18a made of a metal vapor deposition film layer is laminated. Thus, the thickness of the bottom portion 25 of the outer shell body 21 is made thicker than the cylindrical portion 24.

As described above, the increase in the molten resin pressure accompanying the flow of the molten resin can be dealt with by adjusting the cooling of the bottle body 11 by the cooling air a and the thickening of the peripheral wall of the outer shell body 21 mutually. However, as for the setting of the wall thickness of the outer wall of the outer shell body 21, the following values can be used as a guideline as a result of experimental investigation.
(1) When a decorative layer is not laminated near the bottom, the peripheral wall of the cylindrical portion 24 and the bottom 25 are made to have a thickness of at least 3 mm. If there is a thin portion of 2.5 mm, wrinkles due to deformation of the bottle body 11 are visible from the outside.
(2) When a decorative layer is laminated in the vicinity of the bottom, the peripheral wall of the tubular portion 24 is at least 3 mm, and the bottom 25 is at least 4 mm thick.
If the bottom portion 25 has a thin portion of 3.5 mm, wrinkles are observed in the decorative layer.
In addition, it is preferable to make the bottom part 25 have a thickness of at least 5 mm in a case where the decorative layer is easily thermally deformed, such as a metal vapor deposition film layer.

Next, FIGS. 7 and 8 show a second embodiment of the synthetic resin bottle of the present invention. FIG. 7 is an overall perspective view, FIG. 2 (a) is a half vertical sectional view, and (b) is a bottom view. In this example, the cylindrical outer shell 21 is combined with the cylindrical bottle body 11.
The bottle 1 has a cylindrical mouth tube part 2, a shoulder part 3, a cylindrical body part 4 and a bottom part 5. The bottle body 11 and a transparent covering the bottle body 11 are provided in the same manner as the bottle of the first embodiment. It is composed of a thick outer shell body 21 having a total height of 85 mm and a body portion 4 having a diameter of 47 mm.

  The bottle body 11 is a biaxial stretch blow-molded product made of polypropylene (PP) resin. Although a decorative layer is not laminated as in the first embodiment, a fine powder filler is dispersed in a PP resin so as to exhibit a pearl-like appearance based on white.

  The outer shell 21 is made of a transparent ethylene-based ionomer resin (High Milan manufactured by Mitsui, DuPont Polychemical Co., Ltd.), and has a bottomed cylindrical body composed of a cylindrical cylindrical portion 24 and a bottom portion 25. In this embodiment, since the decorative layer is not laminated on the bottle body 11, the thickness of the peripheral wall of the cylindrical portion 24 is 3.5 mm, and the thickness of the bottom portion 25 is 3.5 mm at the thin portion. Compared to the case of the first embodiment in which the layers are stacked, the thickness is set to be thin overall.

  The bottle 1 can be molded by the same molding method as described in FIGS. 5 and 6, and the deformation of the main body of the bottle 11 is sufficiently suppressed so that it is not visually recognized from the outside. A high-quality decoration is exhibited by the visual effect that the bottle body 11 exhibiting the appearance floats in the thick and transparent outer shell 21.

As described above, the configuration of the synthetic resin bottle of the present invention, the molding method thereof, and the function and effect thereof have been described according to the examples. However, the present invention is not limited to these examples. The present invention can be developed in various variations, as described in the above description, such as combinations of outer shell shapes.

As described above, the synthetic resin bottle of the present invention exhibits a variety of high-quality and decorative properties including a lamination of a decorative layer by a transparent outer shell body, such as a cosmetic container. A wide range of usage expansion is expected in the field.

DESCRIPTION OF SYMBOLS 1; Bottle 2; Mouth part 3; Shoulder part 4; Trunk part 5; Bottom part 11; Bottle main body 12; Mouth part 13; Shoulder part 14; Body part 15: Bottom part 18a, 18b; Body 24; cylindrical portion 25; bottom 27; gate mark 31; injection mold 32; bottle body holding portion 33; cavity mold 34; cavity 36; air pin 37;

Claims (9)

A synthetic resin bottle made of a synthetic resin blow-molded casing is used as an insert material, and a bottomed cylindrical transparent synthetic resin outer shell covering the body and bottom of the bottle body is injection molded. A molding method, in which cooling air is circulated and supplied into a bottle body set in an injection mold, and is filled with a molten resin that forms an outer shell body by a metering and filling method. Employment avoids the pressure rise related to the pressure holding process, suppresses the temperature rise of the bottle body by the cooling air, and increases the molten resin pressure related to the flow of the molten resin by thickening the peripheral wall of the outer shell body. A synthetic resin bottle characterized in that the degree of cooling by the cooling air and the increase in the thickness of the peripheral wall of the outer shell body are set to such an extent that the bottle body is not deformed by the molten resin pressure. Molding method. Using an injection mold with a gate opening disposed opposite the center of the bottom bottom of the bottle body, the bottle body shall have a wall thickness of at least 0.8 mm, and the bottom and cylindrical parts of the outer shell The method for molding a synthetic resin bottle according to claim 1, wherein the shape of the mold cavity is set so that the peripheral wall has a thickness of at least 3 mm. It is assumed that the decorative layer is laminated on a predetermined area on the outer peripheral surface of the bottle body, and the degree of cooling by cooling air and the thickening of the peripheral wall of the outer shell body are cracked in the decorative layer by the molten resin pressure. The method for molding a synthetic resin bottle according to claim 1, wherein the method is set to such a level that no wrinkles are generated. Using an injection mold with a gate opening disposed opposite to the center of the bottom bottom of the bottle body, the bottle body has a wall thickness of at least 0.8 mm, and the bottom of the outer shell is at least 4 mm The method for molding a synthetic resin bottle according to claim 3, wherein the shape of the mold cavity is set so that the peripheral wall of the cylindrical portion has a thickness of at least 3 mm. The method for molding a synthetic resin bottle according to claim 2 or 4, wherein cooling air is supplied from the vicinity of the bottom in the bottle body. The method for molding a synthetic resin bottle according to claim 2, 4 or 5, wherein the tip of an air pin for supplying cooling air is brought into contact with the bottom of the bottle body. A bottle body that is a synthetic resin blow housing with a continuous mouth tube portion;
A bottomed cylindrical transparent composite formed by injection molding in which the bottle main body is used as an insert material and a gate portion is disposed at a position facing the bottom of the bottle main body, and covers the body and bottom of the bottle main body. A resin outer shell, the bottle body has a wall thickness of at least 0.8 mm, and the peripheral wall of the bottom and the cylindrical portion of the outer shell has a thickness of at least 3 mm; Synthetic resin bottle characterized by that. The synthetic resin bottle according to claim 7, wherein the insert material is formed by laminating a decorative layer in a region including at least the vicinity of the bottom of the outer peripheral surface of the bottle body, and the bottom of the outer shell has a thickness of at least 4 mm. . The synthetic resin bottle according to claim 8, wherein the decorative layer is at least one layer selected from a printed layer, a coating film layer, or a metal vapor deposition film layer.

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