JP2021133550A - preform - Google Patents

Abstract

To provide a preform capable of manufacturing a laminated peelable container that enhances peelability of an inner layer body from an outer layer body.SOLUTION: A preform 1 for blow molding has: an outer preform 10 provided with an outer mouth part 11 and a bottomed cylindrical outer stretch part 12 connected to the outer mouth part 11; an inner preform 20 provided with an inner mouth part 21 disposed inside the outer mouth part 11 and a bottomed cylindrical inner stretch part 22 connected to the inner mouth part 21; an outer-air introduction port 40 provided on a mouth part 2 configured by the outer mouth part 11 and the inner mouth part 21, and communicates to between the outer preform 10 and the inner preform 20; and an annular recessed part 13 provided by extending in a circumferential direction on an outer side surface of an upper end part of the outer stretch part 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a preform for blow molding used in manufacturing a laminated peeling container made of a synthetic resin having an outer layer body and an inner layer body.

As a container for storing food seasonings such as soy sauce, cosmetics such as beverages and lotions, and toiletries such as shampoo, conditioner, and liquid soap as the content liquid, it is detachably laminated on the outer layer and the inner surface of the outer layer. A synthetic resin laminated stripping container having a volume-reducing and deformable inner layer body and an outside air introduction port communicating between the outer layer body and the inner layer body is known.

In the laminated stripping container, after the content liquid is poured out, the outside air is introduced between the inner layer body and the outer layer body from the outside air introduction port, so that the outer layer body is restored while the inner layer body is reduced in volume and deformed. It can be maintained or restored to its shape. Therefore, according to the laminated stripping container, the content liquid stored in the inner layer body can be discharged to the outside without being replaced with the outside air, so that the content liquid stored in the inner layer body can be discharged to the outside air. It is possible to reduce contact and suppress deterioration and deterioration of the content liquid.

Conventionally, as a preform used when manufacturing a laminated peeling container having the above structure by blow molding, an outer preform having a bottomed tubular outer extension portion connected to the outer opening portion and the outer opening portion, and an outer preform are provided. Provided in the inner preform having the inner mouth part arranged inside the mouth part and the bottomed tubular inner extension part connected to the inner mouth part, and the mouth part composed of the outer mouth part and the inner mouth part. It has an outside air introduction port that communicates between the outer preform and the inner preform, and a vertical rib that is integrally provided on the outer surface of the inner preform and extends across the inner opening and the inner extension. Is known (see, for example, Patent Document 1).

According to such an assembly type preform, a stretched portion composed of an outer stretched portion of the outer preform and an inner stretched portion of the inner preform is stretched by blow molding to form a laminated peeling container having a predetermined shape. In addition, a vertical rib can form a ventilation path for outside air extending from the outside air introduction port toward the body portion between the outer layer body and the inner layer body of the laminated stripping container after molding.

JP-A-2019-81604

However, in the above-mentioned conventional preform, at the time of blow molding, the lower end side portion of the vertical rib provided extending across the inner opening portion and the inner extending portion is formed on the inner surface of the outer extending portion of the outer preform. Since it is deformed while being strongly pressed, in the laminated peeling container after blow molding, the vicinity of the stretching start portion (for example, the lower end portion of the vertical rib) is in a state of being stuck to the inner surface of the outer layer body, and the inner layer is in the said portion. There was a risk that the progress of detachment from the outer layer of the body would be hindered.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a preform capable of producing a laminated peeling container having improved peelability of an inner layer body from an outer layer body.

The preform of the present invention is a preform for blow molding, and includes an outer preform including an outer mouth portion and a bottomed tubular outer extension portion connected to the outer mouth portion, and the outer mouth portion. An inner preform having an inner mouth portion arranged inside the interior and a bottomed tubular inner extension portion connected to the inner mouth portion, and a mouth composed of the outer mouth portion and the inner mouth portion. An outside air introduction port provided in the portion and communicating between the outer preform and the inner preform, and an annular recess provided on the outer surface of the upper end portion of the outer extension portion extending in the circumferential direction. It is characterized by having.

In the preform of the present invention, in the above configuration, a plurality of vertical ribs extending across the inner opening portion and the inner extending portion are integrally provided on the outer surface of the inner preform, and the lower end of the vertical rib is formed. , It is preferable that the annular recess is arranged inside in the radial direction.

In the preform of the present invention, in the above configuration, the annular recess has a downward tapered upper step surface, a cylindrical bottom surface connected to the lower end of the upper step surface, and an upward tapered lower surface connected to the lower end of the bottom surface. It is preferable to have a side stepped surface.

In the above configuration, the preform of the present invention is integrally provided with a plurality of vertical ribs extending across the inner mouth portion and the inner extension portion on the outer surface of the inner preform, and the vertical ribs are formed by the vertical ribs. It is preferable that the inner preform is provided with an inclined portion in which the height of protrusion from the outer surface gradually decreases toward the lower end, and the inclined portion is arranged radially inside the upper step surface.

In the preform of the present invention, in the above configuration, a neck ring is integrally provided on the outer surface of the outer mouth portion, and a portion of the outer preform between the neck ring and the annular recess has a constant outer diameter. It is preferably cylindrical.

In the preform of the present invention, in the above configuration, it is preferable that the outside air introduction port is a through hole that penetrates the outside port portion in the radial direction.

In the preform of the present invention, in the above configuration, it is preferable that the outer preform and the inner preform are each made of polyethylene terephthalate.

According to the present invention, it is possible to provide a preform capable of producing a laminated peeling container having improved peelability of the inner layer body from the outer layer body.

It is a half cross-sectional view of the preform which is one Embodiment of this invention. It is sectional drawing which follows the AA line in FIG. It is an enlarged cross-sectional view which shows the outer mouth part and the inner mouth part of the preform shown in FIG. 1 in an enlarged manner. It is sectional drawing of the state in which the preform shown in FIG. 1 is arranged in the mold for blow molding. FIG. 5 is a cross-sectional view showing a state in which the preform shown in FIG. 4 is molded into a laminated peeling container by blow molding.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The preform 1 for blow molding, which is one embodiment of the present invention shown in FIGS. It is molded into a laminated stripping container made of synthetic resin, which has an inner layer body and an outside air introduction port communicating between the outer layer body and the inner layer body.

In the present specification and claims, the vertical direction means the vertical direction in the state where the preform 1 is in the upright posture shown in FIG. 1, and the radial direction is the axial center O of the preform 1. As you can see, it means the direction along the straight line perpendicular to the axis O.

The preform 1 has a double structure having an outer preform 10 and an inner preform 20 incorporated inside the outer preform 10.

The outer preform 10 is made of synthetic resin, and has an outer opening portion 11 and an outer extending portion 12 as shown in FIG.

The outer port portion 11 is a portion that is not stretched by blow molding, and constitutes the outer port portion of the laminated stripping container after blow molding. As shown in FIG. 2, the outer opening portion 11 has a cylindrical shape centered on the axis O. As shown in FIGS. 1 and 3, a male screw 11a is integrally provided on the outer surface of the outer opening portion 11. The male screw 11a is for attaching a pouring cap (not shown) having a spout to the outer port of the laminated stripping container after blow molding by screw coupling.

The outer port portion 11 may be configured to have an annular protrusion for attaching the injection cap by tapping instead of the male screw 11a.

A neck ring 11b is integrally provided on the outer surface of the outer opening portion 11 below the male screw 11a. The neck ring 11b has a flange shape extending over the entire circumference of the outer opening portion 11, and projects outward from the outer peripheral surface of the outer opening portion 11 in the radial direction.

The outer extending portion 12 is a portion stretched by blow molding, and as shown in FIG. 1, is integrated with a cylindrical outer main body portion 12a integrally connected to the lower end of the outer opening portion 11 and an integral portion with the lower end of the outer main body portion 12a. It has a bottomed tubular shape provided with a hemispherical outer bottom portion 12b connected to the above.

The outer preform 10 can be configured as, for example, an injection-molded product formed by injection-molding a synthetic resin material. In the present embodiment, the outer preform 10 is an injection-molded product made of polyethylene terephthalate formed by injection-molding a polyethylene terephthalate resin.

The outer preform 10 is not limited to the one made of polyethylene terephthalate, and for example, polyester resin, polyolefin resin, nylon resin, polycarbonate resin (PC resin), cycloolefin copolymer resin (COC resin), cycloolefin polymer resin (COP resin). It can also be made of other synthetic resin materials such as.

The inner preform 20 is made of synthetic resin and includes an inner opening portion 21 and an inner extending portion 22.

As shown in FIG. 2, the inner opening portion 21 has a cylindrical shape having a smaller diameter than the outer opening portion 11, and is arranged coaxially with the outer opening portion 11 inside the outer opening portion 11. The inner mouth portion 21 and the outer mouth portion 11 constitute the mouth portion 2 of the preform 1. The inner mouth portion 21 is a portion that is not stretched by blow molding, and constitutes the inner mouth portion of the laminated stripping container after blow molding.

A gap 30 is provided between the outer opening portion 11 and the inner opening portion 21. As shown in FIG. 3, a diameter-expanded portion 21a is integrally provided at the upper end of the inner mouth portion 21, and the outer surface of the diameter-expanded portion 21a extends over the inner surface of the outer mouth portion 11 over the entire circumference. By abutting, the upper end portion of the gap 30 between the outer opening portion 11 and the inner opening portion 21 is closed to the outside. Further, a flange portion 21b extending outward in the radial direction is integrally provided at the upper end of the diameter-expanded portion 21a, and the flange portion 21b abuts on the upper end of the outer opening portion 11, so that the inner opening portion 21 is outside. It is positioned axially with respect to the mouth portion 11.

The inner stretched portion 22 is a portion stretched by blow molding, and as shown in FIG. 1, is integrated with a cylindrical inner main body portion 22a that is integrally connected to the lower end of the inner mouth portion 21 and a lower end of the inner main body portion 22a. It has a bottomed tubular shape provided with a hemispherical inner bottom portion 22b connected to the above. A slight gap is provided between the inner surface of the outer stretched portion 12 and the outer surface of the inner stretched portion 22, and when the inner preform 20 is incorporated into the outer preform 10, the outer stretched portion 12 is provided with a slight gap. The inner side surface and the outer surface of the inner extension portion 22 are not scratched. The inner stretched portion 22 constitutes the stretched portion 3 of the preform 1 together with the outer stretched portion 12.

The inner preform 20 can be configured as, for example, an injection-molded product formed by injection-molding a synthetic resin material. In the present embodiment, the inner preform 20 is an injection-molded product made of polyethylene terephthalate formed by injection-molding a polyethylene terephthalate resin, similarly to the outer preform 10.

The inner preform 20 is not limited to polyethylene terephthalate, and for example, polyester resin, polyolefin resin, nylon resin, polycarbonate resin (PC resin), cycloolefin copolymer resin (COC resin), cycloolefin polymer resin (COP resin). , Ethylene-vinyl alcohol copolymer resin (EVOH resin) and other synthetic resin materials may be used. When the inner preform 20 is made of an ethylene-vinyl alcohol copolymer resin, one having an appropriate ethylene content can be adopted in consideration of barrier properties and flexibility. Further, the inner preform 20 may have a multi-layer structure in which a barrier layer such as an MX nylon resin layer is provided between a pair of polyethylene terephthalate layers in order to secure the barrier property.

The outside air introduction port 40 is provided in the mouth portion 2 of the preform 1 composed of the outer mouth portion 11 and the inner mouth portion 21. The outside air introduction port 40 communicates between the outer preform 10 and the inner preform 20, that is, in the gap 30, and introduces outside air between the outer preform 10 and the inner preform 20 through the outside air introduction port 40. be able to.

In the present embodiment, the outer port portion 11 is provided with a pair of outside air introduction ports 40. Each of the pair of outside air introduction ports 40 is a through hole that penetrates the outer port portion 11 in the radial direction, and is arranged symmetrically on both sides of the outer port portion 11 with the axial center O interposed therebetween. Further, each of the pair of outside air introduction ports 40 has an elongated hole shape extending in the circumferential direction.

A vertical rib 23 is integrally provided on the outer surface of the inner preform 20. As shown in FIG. 3, the vertical rib 23 projects radially outward from the outer surface of the inner preform 20, straddles the inner opening portion 21 and the inner extending portion 22, and extends in the vertical direction along the axial center O. It extends straight. By integrally providing the vertical ribs 23 on the outer surface of the inner preform 20, the inner preform 20 is positioned so that a gap 30 is formed between the inner preform 20 and the outer preform 10.

In the present embodiment, as shown in FIG. 2, a plurality of vertical ribs 23 are provided side by side at intervals in the circumferential direction on the outer surface of the inner preform 20. More specifically, on the outer surface of the inner preform 20, five vertical ribs 23 are arranged in a predetermined range in the circumferential direction centered on one of the outside air introduction ports 40 at intervals equal to the circumferential direction. In addition to being provided, five vertical ribs 23 are provided side by side at intervals equal to the circumferential direction in a predetermined range in the circumferential direction centered on the other outside air introduction port 40. Further, the distance between the vertical rib group consisting of five vertical ribs 23 centered on one outside air introduction port 40 and the vertical rib group consisting of five vertical ribs 23 centered on the other outside air introduction port 40 is , It is larger than the distance between the adjacent vertical ribs 23 in each vertical rib group. Of the five vertical ribs 23 provided in a predetermined range in the circumferential direction centered on one outside air introduction port 40, the three vertical ribs 23 excluding the two at both ends are each one of the outside air introduction ports 40. Of the five vertical ribs 23 that face each other and are provided in a predetermined range in the circumferential direction centered on the other outside air introduction port 40, the three vertical ribs 23 excluding the two at both ends are each. It faces the other outside air introduction port 40. Of the five vertical ribs 23, the vertical rib 23 in the middle in the circumferential direction is arranged so as to vertically straddle the outside air introduction port 40 at the center position in the circumferential direction of the corresponding outside air introduction port 40.

As shown in FIG. 3, each of the vertical ribs 23 is integrally connected to the lower side of the rib body 23a and the rib body 23a that abuts on the inner surface of the outer preform 10 at the outer end in the radial direction, and the inner rib 23 is formed. It is provided with an inclined portion 23b in which the protruding height from the outer surface of the reform 20 gradually decreases toward the lower end. The lower end of the inclined portion 23b of each vertical rib 23 faces the outer main body portion 12a of the outer extending portion 12 of the outer preform 10. On the other hand, the upper end of the rib body portion 23a of each vertical rib 23 reaches the diameter-expanded portion 21a and is integrally connected to the diameter-expanded portion 21a.

An annular recess 13 extending in the circumferential direction is provided on the outer surface of the upper end portion of the outer extension portion 12 of the outer preform 10.

As shown in FIG. 3, the annular recess 13 has a downwardly tapered upper step surface 13a whose diameter decreases downward, a cylindrical bottom surface 13b connected to the lower end of the upper step surface 13a, and a lower end of the bottom surface 13b. It has a groove shape with an upwardly tapered lower step surface 13c that is continuous with the above and expands in diameter toward the bottom. In the portion where the annular recess 13 is provided, the thickness of the outer main body portion 12a of the outer preform 10 is thinner than the other portions.

The portion 14 of the outer preform 10 between the neck ring 11b and the annular recess 13 has a cylindrical shape with a constant outer diameter. The portion 14 is a portion that is not substantially stretched when the preform 1 is blow-molded, but the lower end side portion of the portion 14 may be slightly stretched.

In the present embodiment, the lower end of the vertical rib 23 is arranged inside the annular recess 13 in the radial direction. That is, the vertical position of the lower end of the vertical rib 23 is located between the upper step surface 13a and the lower step surface 13c of the annular recess 13.

Further, in the present embodiment, the inclined portion 23b of the vertical rib 23 is arranged inside the upper step surface 13a of the annular recess 13 in the radial direction. That is, the inclined portion 23b of the vertical rib 23 and the upper step surface 13a of the annular recess 13 are arranged so as to face each other in the radial direction so that the positions in the vertical direction overlap each other.

The preform 1 of the present embodiment having the above configuration is, for example, formed into a laminated peeling container 60 having a predetermined shape as shown in FIG. 5 by blow molding using a mold 50 for blow molding as shown in FIG. It is molded.

More specifically, at the time of blow molding, as shown in FIG. 4, the preform 1 is in the mold 50, and the mouth portion 2 (outer mouth portion 11 and inner mouth portion 21) is a cavity of the mold 50. The neck ring 11b is supported on the upper surface of the mold 50 while protruding upward from the 50a, and the stretched portion 3 (outer stretched portion 12 and inner stretched portion 22) is arranged so as to be located inside the cavity 50a. At this time, the cylindrical portion 14 between the neck ring 11b of the outer preform 10 and the annular recess 13 is supported by the inner peripheral surface of the opening hole 50b of the mold 50, and the annular recess 13 is inside the cavity 50a. It is designed to be located.

As shown in FIG. 4, in a state where the preform 1 is arranged in the mold 50, pressurized air, a pressurized liquid, or the like is applied from a pressurized medium supply device (not shown) through a mouth portion 2 inside the preform 1. By supplying the pressure medium, the stretched portion 3 of the preform 1 is stretched into a shape along the inner surface of the cavity 50a, and as shown in FIG. 5, the stretched portion 61 having the same shape as the mouth portion 2 and the mouth portion 61. It has a bottle shape with an enlarged shoulder portion 62 connected to the lower end of the mouth portion 61 and a bottomed tubular body portion 63 connected to the radial outer end of the shoulder portion 62, and is compatible with the outer preform 10. A double-structured laminated peeling container 60 having an outer layer body 64 and an inner layer body 65 corresponding to the inner preform 20 is formed. At this time, as shown in FIG. 4, the cylindrical portion 14 between the neck ring 11b of the outer preform 10 and the annular recess 13 is supported by the inner peripheral surface of the opening hole 50b of the mold 50, and the annular recess 13 Is arranged so as to be located inside the cavity 50a, so that in the laminated peeling container 60 after blow molding, a portion of a predetermined range from the portion of the shoulder portion 62 connected to the mouth portion 61 toward the body portion 63 side is formed. , The portion of the outer stretched portion 12 provided with the annular recess 13 is stretched to form the outer stretched portion 12.

Here, in the preform 1 of the present embodiment, as shown in FIG. 3, an annular recess 13 extending in the circumferential direction is provided on the outer surface of the upper end portion of the outer extending portion 12 of the outer preform 10, and the outer extending portion 12 is provided. Since the thickness of the portion provided with the annular recess 13 is made thinner than the thickness of the other portion, the portion provided with the annular recess 13 in the laminated peeling container 60 formed by blow molding the preform 1. In a predetermined range portion of the shoulder portion 62 or a predetermined range portion extending from the shoulder portion 62 to the body portion 63 formed by stretching the outer layer body 64, the outer layer body 64 is formed thinner than the other portion of the shoulder portion 62. It will be. As a result, the outer layer body 64 can be deformed more flexibly in the predetermined range portion of the shoulder portion 62, and the inner layer body 65 can be easily separated from the outer layer body 64.

Therefore, in the laminated peeling container 60 formed by blow molding the preform 1, when the content liquid is poured out, the outer layer 64 formed by the vertical ribs 23 from the outside air introduction port 40 provided in the mouth portion 61. A ventilation path for flowing the outside air introduced into the gap 30 between the inner layer 65 and the inner layer 65 toward the body 63 is provided from the portion of the shoulder 62 connected to the mouth 61 to the body 63 side. It can be easily secured in the portion of the predetermined range to be directed. As described above, according to the preform 1 of the present embodiment, the laminated peeling container 60 having improved peelability of the inner layer 65 to the outer layer 64 can be molded by blow molding.

Further, in the present embodiment, as described above, the preform 1 is configured such that the lower end of the vertical rib 23 is arranged inside the annular recess 13 in the radial direction. As a result, in the laminated peeling container 60 after blow molding, the vertical ribs 23 are arranged so as to straddle the curved connecting portion between the mouth portion 61 and the shoulder portion 62, and between the mouth portion 61 and the shoulder portion 62. In the curved connecting portion of the above, the vertical rib 23 makes it easy to secure a ventilation path for flowing the outside air introduced into the gap 30 from the outside air introduction port 40 toward the body portion 63 side. Therefore, in the laminated peeling container 60 formed by blow molding the preform 1, when the content liquid is poured out, the outside air introduced into the gap 30 from the outside air introduction port 40 provided in the mouth portion 61 is introduced into the body portion. It is possible to ensure that a ventilation path for flowing to the side of 63 is secured more reliably.

As described above, when the preform 1 is configured such that the lower end of the vertical rib 23 is arranged inside the annular recess 13 in the radial direction, the lower end side portion of the vertical rib 23 is stretched outward during blow molding. Since the annular recess 13 of the portion 12 is provided, the portion is stretched together with the portion whose thickness has been reduced. Therefore, in the laminated peeling container 60 after blow molding, the lower end side portion of the vertical rib 23 is formed on the shoulder portion 62 of the outer layer body 64. It will be located in a predetermined range formed thinner than the other portions. As a result, in the laminated peeling container 60 formed by blow molding the preform 1, the lower end side portion of the vertical rib 23 is suppressed from sticking to the inner side surface of the shoulder portion 62 of the outer layer body 64, and the inner layer body 65 The peelability to the outer layer 64 can be further enhanced.

In particular, when the inclined portion 23b of the vertical rib 23 is arranged inside the upper step surface 13a of the annular recess 13 in the radial direction as in the preform 1 of the present embodiment, the preform 1 is blown. In the laminated peeling container 60 formed by molding, the lower end side portion of the vertical rib 23 is more effectively suppressed from sticking to the inner side surface of the shoulder portion 62 of the outer layer body 64, with respect to the outer layer body 64 of the inner layer body 65. The peelability can be further enhanced.

Further, as in the preform 1 of the present embodiment, the annular recess 13 is connected to the downward tapered upper step surface 13a, the cylindrical bottom surface 13b connected to the lower end of the upper step surface 13a, and the lower end of the bottom surface 13b. When the shape has an upward tapered lower step surface 13c, the portion of the outer extending portion 12 provided with the annular recess 13 is stepped from the portion not provided with the annular recess 13 by blow molding. Can be formed into an inconspicuous and smooth shape. As a result, in the laminated peeling container 60 formed by blow molding the preform 1, the shoulder portion 62 has a shape in which the step due to the annular recess 13 is inconspicuous, and the appearance of the laminated peeling container 60 can be enhanced.

Further, when the portion 14 between the neck ring 11b of the outer preform 10 and the annular recess 13 is formed into a cylindrical shape having a constant outer diameter as in the preform 1 of the present embodiment, when blow molding is performed. In addition, while ensuring that the preform 1 is reliably supported by the mold 50, the entire portion of the outer extending portion 12 provided with the annular recess 13 can be stretched by blow molding. As a result, in the laminated peeling container 60 formed by blow molding the preform 1, the peelability of the inner layer 65 to the outer layer 64 can be more effectively enhanced.

Further, when the outside air introduction port 40 is a through hole penetrating the outer port portion 11 in the radial direction as in the preform 1 of the present embodiment, the preform 1 has a simpler configuration and its cost. Can be reduced.

Further, when a plurality of vertical ribs 23 are arranged side by side on the outer surface of the inner preform 20 at intervals in the circumferential direction as in the preform 1 of the present embodiment, the preform 1 is provided. In the laminated peeling container 60 formed by blow molding, a ventilation path can be formed between each of the adjacent vertical ribs 23. As a result, in the laminated peeling container 60 formed by blow molding the preform 1, the outside air introduced into the gap 30 from the outside air introduction port 40 between the outer layer body 64 and the inner layer body 65 is transferred to the body portion 63. It is possible to make it easier to secure a ventilation path for flowing toward the side, and to further enhance the peelability of the inner layer body 65 to the outer layer body 64.

Further, when at least one vertical rib 23 is made to face the outside air introduction port 40 as in the preform 1 of the present embodiment, the outside air introduction port 40 is formed by the vertical rib 23. The peelability of the inner layer 65 to the outer layer 64 can be further enhanced by ensuring that the inner layer 65 is communicated with the air passage through the gap 30.

Further, as in the preform 1 of the present embodiment, the outside air introduction ports 40 are provided on both sides of the axial center O of the outer port portion 11, and a plurality of vertical ribs corresponding to the respective outside air introduction ports 40 are provided. When the 23 is provided, in the laminated peeling container 60 formed by blow molding the preform 1, the peeling of the inner layer 65 from the outer layer 64 proceeds from both sides of the axial center O. Therefore, the peelability of the inner layer 65 to the outer layer 64 can be further enhanced.

Further, when the outer preform 10 and the inner preform 20 are each made of polyethylene terephthalate (PET) as in the preform 1 of the present embodiment, the laminated peeling container 60 is lightweight and highly transparent. It can be a container.

It goes without saying that the present invention is not limited to the above-described embodiment and can be variously modified without departing from the gist thereof.

For example, in the above-described embodiment, the inner preform 20 is provided with a plurality of vertical ribs 23, but the present invention is not limited to this, and the inner preform 20 may be provided with at least one vertical rib 23. The vertical rib 23 may not be provided.

Further, in the above-described embodiment, the annular recess 13 has a downward tapered upper step surface 13a, a cylindrical bottom surface 13b connected to the lower end of the upper step surface 13a, and an upward tapered lower side connected to the lower end of the bottom surface 13b. The shape has a stepped surface 13c, but the shape is not limited to this, and the shape can be variously changed as long as it is provided in the outer extending portion 12 and is recessed in an annular shape so as to reduce the thickness of the portion. It is possible.

Further, in the above embodiment, the lower end of the vertical rib 23 is arranged inside the annular recess 13 in the radial direction, but the present invention is not limited to this, and the lower end of the vertical rib 23 is above the annular recess 13. Alternatively, the arrangement may be shifted downward.

Further, in the above embodiment, the inclined portion 23b of the vertical rib 23 is arranged inside the upper step surface 13a of the annular recess 13 in the radial direction, but the present invention is not limited to this, and the inclined portion 23b of the vertical rib 23 is not limited to this. May be arranged so as to be shifted upward or downward with respect to the upper step surface 13a of the annular recess 13.

Further, in the above-described embodiment, the portion 14 between the neck ring 11b of the outer preform 10 and the annular recess 13 is formed into a cylindrical shape having a constant outer diameter, but the shape of the portion 14 is not limited to this. It can be changed.

Further, the outer port portion 11 may not be provided with the neck ring 11b.

Further, in the above-described embodiment, the outside air introduction port 40 is provided in the outer port portion 11 and is a through hole that penetrates the outer port portion 11, but the present invention is not limited to this, and for example, the upper end and the inner side of the outer port portion 11 are limited. The configuration or shape can be variously changed, such as being provided between the upper end of the mouth portion 21 and opening the gap 30 to the outside.

Further, in the above-described embodiment, the outer port portion 11 is provided with a pair of outside air introduction ports 40, but at least one outside air introduction port 40 may be provided.

1 Preform 2 Mouth 3 Stretched part 10 Outer preform 11 Outer mouth 11a Male screw 11b Neck ring 12 Outer extension 12a Outer body 12b Outer bottom 13 Circular recess 13a Upper step surface 13b Bottom 13c Lower step surface 14 Part 20 Inner preform 21 Inner mouth 21a Expanded diameter 21b Flange 22 Inner extension 22a Inner body 22b Inner bottom 23 Vertical rib 23a Rib body 23b Inclined 30 Gap 40 Outside air introduction port 50 Mold 50a Cavity 50b Opening hole 60 Laminated peeling container 61 Mouth 62 Shoulder 63 Body 64 Outer layer 65 Inner layer 66 Outside air introduction port 67 Gap O Axial center

Claims (7)

Preform for blow molding
An outer preform having an outer mouth portion and a bottomed tubular outer extension portion connected to the outer mouth portion,
An inner preform having an inner mouth portion arranged inside the outer mouth portion and a bottomed tubular inner extension portion connected to the inner mouth portion.
An outside air introduction port provided in a mouth portion composed of the outer mouth portion and the inner mouth portion and communicating between the outer preform and the inner preform, and an outside air introduction port.
A preform characterized by having an annular recess extending in the circumferential direction on the outer surface of the upper end portion of the outer extending portion. A plurality of vertical ribs extending across the inner opening portion and the inner extending portion are integrally provided on the outer surface of the inner preform.
The preform according to claim 1, wherein the lower end of the vertical rib is arranged inside the annular recess in the radial direction. 1. The annular recess has an upward tapered upper step surface, a cylindrical bottom surface connected to the lower end of the upper step surface, and an upward tapered lower step surface connected to the lower end of the bottom surface. Or the preform according to 2. A plurality of vertical ribs extending across the inner opening portion and the inner extending portion are integrally provided on the outer surface of the inner preform.
The vertical ribs are provided with an inclined portion in which the height of protrusion of the inner preform from the outer surface gradually decreases toward the lower end.
The preform according to claim 3, wherein the inclined portion is arranged inside in the radial direction of the upper step surface. A neck ring is integrally provided on the outer surface of the outer opening portion, and the neck ring is integrally provided.
The preform according to any one of claims 1 to 4, wherein the portion of the outer preform between the neck ring and the annular recess is cylindrical with a constant outer diameter. The preform according to any one of claims 1 to 5, wherein the outside air introduction port is a through hole that penetrates the outside port portion in the radial direction. The preform according to any one of claims 1 to 6, wherein the outer preform and the inner preform are each made of polyethylene terephthalate.

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