JP7098255B2 - Laminated preforms and laminated containers - Google Patents

Description

The present invention relates to a laminated preform having an inner preform and an outer preform, and a laminated container formed by blow molding the laminated preform.

Conventionally, by blow molding using a laminated preform having a bottomed tubular inner preform and an outer preform covering the outer surface of the inner preform, the inner layer corresponding to the inner preform and the outer preform can be obtained. A laminated container having a corresponding outer layer is formed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 49-13856

Here, FIG. 5 shows a laminated preform 200 in which the mouth portion 211 is composed of only the inner preform 210, and the outer preform 220 covers only the body portion 212 (inner body portion) of the inner preform 210. Shows. Specifically, the inner preform 210 shown in FIG. 5 has a tubular mouth portion 211 having a neck ring 213 at the lower end portion, and a bottomed tubular inner body portion 212 connected below the mouth portion 211. The outer preform 220 has an outer body portion 221 that covers the inner body portion 212 below the neck ring 213, and the upper end of the outer preform 220 is in contact with the lower surface of the neck ring 213.

When such a laminated preform 200 is blow-molded to manufacture a laminated container, the laminated preform 200 is generally heated from the outside in a preheating step of heating to a stretchable temperature. The outer body portion 221 of the outer preform 220 is preferentially heated as compared with the inner body portion 212 of the reform 210. Therefore, in the preheating step, the heat shrinkage of the outer preform 220 is larger than that of the inner preform 210, and particularly when the inner preform 210 and the outer preform 220 are made of a material that is difficult to fuse. There was a risk that a gap would be created between the lower surface of the neck ring 213 and the upper end of the outer preform 220. Further, in the laminated container 300 obtained by blow-molding such a laminated preform, as shown in FIG. 6, the outer layer 320 (corresponding to the outer preform 220) is peeled off from the inner layer 310 (corresponding to the inner preform 210) and the neck. There was a risk that a gap G would be created between the lower surface of the ring 213 and the upper end of the outer layer 320.

Therefore, the present invention has a laminated preform having a configuration capable of suppressing peeling of the outer layer from the inner layer when the laminated preform having the outer preform and the inner preform is blow-molded to form a laminated container. And to provide a laminated container.

The present invention has been made to solve the above problems, and the laminated preform of the present invention is a laminated preform having an inner preform and an outer preform.
The inner preform includes a tubular mouth portion having a neck ring at the lower end portion and a bottomed tubular inner body portion connected below the mouth portion.
The outer preform comprises an outer body portion that covers the inner body portion.
The inner flange portion provided at the upper end of the outer body portion is fitted into the engaging recess provided at the upper end of the inner body portion.

In the laminated preform of the present invention, the inner preform and the outer preform are made of an amorphous synthetic resin.
It is preferable that the glass transition temperature of the synthetic resin constituting the inner preform is higher than the glass transition temperature of the synthetic resin constituting the outer preform.

Further, in the laminated preform of the present invention, the engaging recess is continuously provided over the entire circumferential direction of the inner body portion, and the inner flange portion is provided over the entire circumferential direction of the outer body portion. It is preferable that they are continuously provided over.

Further, the laminated container of the present invention is a laminated container having an inner layer and an outer layer.
The inner layer includes a tubular mouth portion having a neck ring at the lower end portion and a bottomed tubular inner layer body portion connected below the mouth portion.
The outer layer includes an outer layer body portion that covers the inner body portion.
The inner flange portion provided at the upper end of the outer layer body portion is fitted into the engaging recess provided at the upper end of the inner layer body portion.

According to the present invention, a laminated preform having a configuration capable of suppressing peeling of an outer layer from an inner layer when a laminated preform having an outer preform and an inner preform is blow-molded to form a laminated container and a laminated preform. Laminated containers can be provided.

It is a figure which shows the laminated preform which is one Embodiment of this invention, and a part is shown in the cross section in the side view. It is a figure which shows the primary preform (inner preform) in the manufacturing process of the laminated preform of FIG. 1, and a part is shown in the cross section in the side view. It is a figure which shows the laminated container which is one Embodiment of this invention, and a part is shown in the cross section in the side view. It is a figure which shows the procedure of the manufacturing method of the laminated container which is one Embodiment of this invention. It is a figure which shows the laminated preform as a comparative example, and a part is shown in the cross section in the side view. It is a figure which shows the laminated container as a comparative example, and a part is shown in the cross section in the side view.

Hereinafter, the present invention will be described in more detail with reference to the drawings. In the specification, claims, abstract, and drawings, the "upper" side and the "lower" side have a mouth portion 11 with respect to the inner body portion 12 of the laminated preform 1 shown in FIG. 1, respectively. The side where the inner body portion 12 is located is the upper side, and the side where the inner body portion 12 is located is the lower side with respect to the mouth portion 11. Further, in the laminated container 100 shown in FIG. 3, the side where the mouth portion 111 is located with respect to the inner layer body portion 112 of the laminated container 100 is the upper side, and the side where the inner layer body portion 112 is located with respect to the mouth portion 111 is the lower side. do.

The laminated preform 1 according to the embodiment of the present invention shown in FIG. 1 has an inner preform 10 and an outer preform 20 laminated and arranged on the outside of the inner preform 10.

The inner preform 10 is made of synthetic resin and includes a tubular mouth portion 11 having a neck ring 13 at the lower end portion and a bottomed tubular inner body portion 12 connected below the mouth portion 11. A male screw portion 11a is provided on the outer peripheral surface of the mouth portion 11. The inner preform 10 can be formed into various shapes according to the shape of the laminated container 100 after production, such as a bottomed cylindrical shape (substantially a test tubular shape) and a bottomed square cylinder shape. The mouth portion 11 of the inner preform 10 is a portion corresponding to the mouth portion 111 of the laminated container 100, and is formed in the same shape as the mouth portion 111 of the laminated container 100 shown in FIG.

At the upper end of the inner body portion 12, an engaging recess 14 for fitting the inner flange portion 22 of the outer preform 20 is provided. As shown in FIG. 2, which shows the inner preform 10 alone, the engaging recess 14 is formed on the outer peripheral surface of the inner body portion 12, and is engaged with the recess bottom surface 14a parallel to the axis O and perpendicular to the axis O. It is configured to have a mating surface 14b and a facing surface 14c facing the engaging surface 14b. In this example, the facing surface 14c is connected to the lower surface of the neck ring 13. The cross-sectional shape of the engaging recess 14 can be changed as appropriate. For example, the bottom surface 14a of the recess, the engaging surface 14b, and the facing surface 14c may each be provided with irregularities.

The outer preform 20 is made of synthetic resin and includes a bottomed tubular outer body portion 21 that covers the inner body portion 12. The outer preform 20 is formed so as to cover the entire inner body portion 12 of the inner preform 10. Further, the outer body portion 21 is arranged in close contact with the outer surface of the inner body portion 12, and the inner surface shape of the outer body portion 21 corresponds to the outer surface shape of the inner body portion 12. At the upper end of the outer body portion 21, an inner flange portion 22 protruding inward in the radial direction from the inner peripheral surface of the outer body portion 21 is provided. The inner flange portion 22 is fitted in the engaging recess 14. As a result, the movement of the inner flange portion 22 provided at the upper end portion of the outer body portion 21 with respect to the engaging recess 14 provided at the upper end portion of the inner body portion 12 in the axial direction (direction along the axis O) is suppressed. As a result, the relative movement of the inner preform 10 and the outer preform 20 in the axial direction is prevented. Further, the shape of the inner flange portion 22 corresponds to the shape of the engaging recess 14. The inner flange portion 22 of this example has an annular inner peripheral surface 22a corresponding to the concave bottom surface 14a, a lower surface 22b corresponding to the engaging surface 14b, and an upper surface 22c corresponding to the facing surface 14c. The upper surface 22c is in contact with the facing surface 14c and the lower surface of the neck ring 13.

By engaging the lower surface 22b of the inner flange portion 22 with the engaging surface 14b, it is possible to prevent the outer preform 20 (outer layer 120) from moving downward with respect to the inner preform 10 (inner layer 110). Can be done. Further, by engaging the upper surface 22c of the inner flange portion 22 with the facing surface 14c, it is possible to prevent the outer preform 20 (outer layer 120) from moving upward with respect to the inner preform 10 (inner layer 110). can.

The engaging recess 14 of this example has a ring shape centered on the axis O, and is continuously provided over the entire circumferential direction of the inner body portion 12. Correspondingly, the inner flange portion 22 of the outer preform 20 also has a ring shape, and is continuously provided over the entire circumferential direction of the outer body portion 21.

FIG. 3 shows a laminated container 100 as an embodiment of the present invention. The laminated container 100 can be manufactured, for example, by blow molding using the above-mentioned laminated preform 1. The laminated container 100 has an inner layer 110 corresponding to the inner preform 10 in the laminated preform 1 and an outer layer 120 corresponding to the outer preform 20 and arranged in close contact with the outside of the inner layer 110. In the laminated container 100, the inside of the inner layer 110 serves as a storage space M for the contents. The inner layer 110 has a mouth portion 111 corresponding to the mouth portion 11 of the inner preform 10, and an inner layer body portion 112 corresponding to the inner body portion 12. The outer layer 120 has an outer layer body portion 121 corresponding to the outer body portion 21.

A male screw portion 111a is provided on the outer peripheral surface of the mouth portion 111, and a cap or the like having a female screw portion on the inner peripheral surface can be attached. A neck ring 113 is provided below the male screw portion 111a (lower end of the mouth portion 111). The neck ring 113 is an annular flange that projects radially outward from the outer peripheral surface of the mouth portion 111. Further, the neck ring 113 is used, for example, as a mounting portion to be mounted on the upper end surface of the mold during blow molding, as a support portion when a cap or the like is attached to the mouth portion 111, and to convey the laminated container 100. It can function as a holding part.

An engagement recess 114 corresponding to the engagement recess 14 is provided at the upper end of the inner layer body portion 112, and the recess bottom surface 114a parallel to the axis O, the engagement surface 114b perpendicular to the axis O, and the engagement surface are provided. It has a facing surface 114c facing 114b. The shape of the engaging recess 114 is determined by the shape of the engaging recess 14 of the laminated preform 1. In this example, the engaging recess 14 is provided directly below the neck ring 13 of the laminated preform 1. Since the region directly below the neck ring 13 is a region that is hardly stretched during blow molding, the engagement state between the engaging recess 14 and the inner flange portion 22 in the laminated preform 1 is adjusted to the laminated container 100 after blow molding. It can be maintained well even in. That is, even in the laminated container 100, the engagement state of the inner flange portion 122 with the engagement recess 114 is well maintained.

At the upper end of the outer layer body portion 121, an inner flange portion 122 that protrudes radially inward from the inner peripheral surface of the outer layer body portion 121 is provided. The inner flange portion 122 of this example has an annular inner peripheral surface 122a corresponding to the concave bottom surface 114a, a lower surface 122b corresponding to the engaging surface 114b, and an upper surface 122c corresponding to the facing surface 114c. The inner flange portion 122 is fitted in the engaging recess 114.

In the laminated container 100, the body portion 103 connected below the mouth portion 111 has a double structure composed of an inner layer body portion 112 and an outer layer body portion 121 laminated and arranged in a close contact state as described above. The body portion 103 is composed of a cylindrical tubular portion 103a, an annular shoulder portion 103b connected to the upper end portion of the tubular portion 103a, and a bottom portion 103c that closes the lower end portion of the tubular portion 103a. The shape of the body 103 is not limited to the illustrated example, and can be changed as appropriate. For example, the cylindrical portion 103a in the illustrated example is formed in a rectangular tubular shape having a rectangular cross section perpendicular to the axis O, but is not limited to this, and the cross section may be circular, elliptical, or other polygon. It may have a different shape. Further, the shape of the bottom portion 103c can be appropriately changed, and for example, the shape may be such that a dome-shaped recess is provided inside the flat outer edge portion constituting the ground contact surface.

The laminated container 100 becomes a laminated container containing the contents by filling the accommodation space M with the contents. The laminated container containing the contents may be provided with, for example, a cap provided with a brush-like applicator that can be attached to and detached from the mouth portion 11, or may be provided with only a cap that simply closes the upper end opening of the mouth portion 11. good.

The method for manufacturing the laminated preform 1 includes a primary preform forming step S1 shown in FIG. 4 and a secondary preform forming step S2 performed after the primary preform forming step S1. Further, the method for manufacturing the laminated container 100 includes a primary preform molding step S1, a secondary preform molding step S2, a preheating step S3, and a blow molding step S4 shown in FIG.

In the primary preform molding step S1, a tubular mouth portion 11 having a neck ring 13 at the lower end portion and a mouth portion are formed by injection molding using the first synthetic resin constituting the inner preform 10 (inner layer 110). This is a step of forming an inner preform 10 (primary preform) including a bottomed tubular inner body portion 12 connected below the 11. Note that FIG. 2 shows the inner preform 10 formed by the primary preform molding step S1 alone.

In the secondary preform molding step S2, the laminated preform 1 (secondary preform) in which the outer surface of the inner body portion 12 of the inner preform 10 is coated with the outer body portion 21 of the outer preform 20 made of the second synthetic resin. Is a process of molding by injection molding. In the secondary preform forming step S2, the outer body portion 21 is formed so that the inner flange portion 22 at the upper end of the outer body portion 21 fits into the engaging recess 14 provided at the upper end of the inner body portion 12. To.

The primary preform molding step S1 and the secondary preform molding step S2 can be performed, for example, by injection molding. In this case, the first synthetic resin or the second synthetic resin can be automatically supplied to the inside of the mold by a conveyor using a screw or the like.

In the secondary preform molding step S2, the laminated preform 1 is molded by injection molding using the second synthetic resin in a state where the inner preform 10 as an insert material is arranged in the mold. can do. That is, the laminated preform 1 can be an insert molded product formed by so-called insert molding.

The preheating step S3 is a step of heating the laminated preform 1 to a temperature at which blow molding is possible (preheating temperature). The "temperature at which the laminated preform 1 can be blow-molded (preheating temperature)" means that the laminated preform 1 in a state where the outer body portion 21 is laminated and arranged on the outside of the inner body portion 12 exhibits a stretching effect. It means a temperature at which blow molding is possible, and is different from the temperature at which the first synthetic resin can be molded alone and the temperature at which the second synthetic resin can be molded alone, which will be described later. be. The preheating step S3 can be performed using, for example, a heating furnace or the like, but the preheating step S3 is not limited to this, and if the laminated preform 1 can be heated to a predetermined temperature, various heating means can be used. can.

The blow molding step S4 is a step of molding the laminated container 100 by blow molding using the laminated preform 1 heated in the preheating step S3. In the blow molding step S4, the laminated preform 1 set in the mold of the blow molding apparatus is expanded and deformed by injecting a pressure medium supplied from the blow nozzle into a shape along the cavity of the mold. Mold. The pressure medium (pressurized fluid) may be a gas or a liquid. Further, the blow molding apparatus that performs the blow molding step S4 may be provided with a stretching rod. In this case, the stretching rod is used for stretching in the vertical direction (direction along the axis O), and the pressure medium is used for stretching in the lateral direction. Can be made to. The configuration of the blow molding apparatus used in the blow molding step S4 is not particularly limited.

Here, the moldable temperature of the first synthetic resin alone is higher than the moldable temperature of the second synthetic resin alone. Further, the preheating temperature in the preheating step S3 is equal to or higher than the temperature at which the second synthetic resin can be molded alone, and is equal to or lower than the temperature at which the first synthetic resin can be molded by itself. The "moldable temperature of the first synthetic resin alone" means that when only the inner body portion 12 of the inner preform 10 made of the first synthetic resin is heated, the inner body portion 12 has a stretching effect. Is the temperature at which blow molding is possible, and similarly, the "moldable temperature of the second synthetic resin alone" is only the outer body portion 21 made of the second synthetic resin. It is a temperature at which a stretching effect is exhibited on the outer body portion 21 and blow molding becomes possible when the outer body portion 21 is heated.

Here, in the present embodiment, when the first synthetic resin is an amorphous nylon resin, the moldable temperature of the first synthetic resin alone is 165 ° C. or higher. When the second synthetic resin is an amorphous PET resin, the moldable temperature of the second synthetic resin alone is 100 ° C to 125 ° C. When the first synthetic resin is an amorphous nylon resin and the second synthetic resin is an amorphous PET resin, the temperature at which the laminated preform 1 can be blow-molded is 130 ° C. or higher.

As described above, in the laminated preform 1 of the present embodiment, the inner flange portion 22 provided at the upper end of the outer body portion 21 is provided in the engaging recess 14 provided at the upper end of the inner body portion 12. It is configured to fit. As a result, even when the heat shrinkage of the outer preform 20 is larger than that of the inner preform 10 in the preheating step S3, the relative movement of the inner preform 10 and the outer preform 20 in the axial direction is prevented. There is no possibility that a gap will be formed between the lower surface of the neck ring 13 and the upper end of the outer preform 20. Therefore, when the laminated preform 1 is blow-molded to form the laminated container 100, it is possible to prevent the outer layer 120 from peeling off from the inner layer 110 to form a gap G as shown in FIG.

Further, in the present embodiment, the engaging recess 14 is continuously provided over the entire circumferential direction of the inner body portion 12, and similarly, the inner flange portion 22 is also continuously provided over the entire circumferential direction of the outer body portion 21. It is supposed to be. With such a configuration, it is possible to exert the effect of suppressing the peeling of the outer layer 120 by the engaging recess 14 and the inner flange portion 22 over the entire circumferential direction of the laminated preform 1 (laminated container 100). The engaging recess 14 and the inner flange portion 22 may have an intermittent shape in the circumferential direction. That is, the engaging recess 14 may be one or a plurality of recesses formed in a part of the inner body portion 12 in the circumferential direction, and the inner flange portion 22 may also be formed according to the shape of the engaging recess 14. , It may be one or more convex portions formed on a part of the outer body portion 21 in the circumferential direction. The engaging recess 14 and the inner flange portion 22 are preferably arranged evenly in the circumferential direction around the axis O, and according to this, the effect of suppressing peeling of the outer layer 120 can be exerted evenly in the circumferential direction. can.

Here, the first synthetic resin constituting the inner preform 10 (inner layer 110) and the second synthetic resin constituting the outer preform 20 (outer layer 120) are amorphous synthetic resins. again,
The glass transition temperature (glass transition point: Tg) of the first synthetic resin constituting the inner preform 10 is higher than the glass transition temperature of the second synthetic resin constituting the outer preform 20. By making the thickness of the inner layer 110 thinner than the thickness of the outer layer 120, the preheating temperature at the time of blow molding can be set low. In this example, the glass transition temperature of the amorphous nylon resin constituting the inner preform 10 (inner layer 110) is 125 ° C., and the glass transition temperature of the amorphous PET resin constituting the outer preform 20 (outer layer 120). Is 70 ° C.

In this example, the inner preform 10 (inner layer 110) is made of an amorphous nylon resin, and the outer preform 20 (outer layer 120) is made of an amorphous PET (polyethylene terephthalate) resin. In this case, the laminated container 100 is used as a container for containing contents such as nail polish containing at least one of ethyl acetate, butyl acetate, toluene, and nitrocellulose as a main component and having an alcohol component of 15% by weight or less. Can be used. The amorphous nylon resin constituting the inner layer 110 has chemical resistance and is suitable for the above-mentioned contents.

Further, when the laminated container 100 is used as a container for nail polish, the nail polish remover is often used near the laminated container 100 when removing the nail polish from the nails, so that the nail polish remover is applied to the outer surface of the laminated container 100. There is a risk of adhesion. On the other hand, since the amorphous PET resin constituting the outer layer 120 has resistance to acetone and alcohol, which are the main components of the nail polish remover, there is no problem even if the nail polish remover adheres. Therefore, the method of using the laminated container 100 of this example is suitable for accommodating the contents such as nail polish as described above.

Further, since the amorphous PET resin constituting the outer layer 120 is cheaper than the amorphous nylon resin constituting the inner layer 110, the material cost is reduced as compared with the case where the entire laminated container 100 is composed of the amorphous nylon resin. can do. Further, by forming the outer layer 120 made of amorphous PET resin into a thick wall, a glass-like container can be obtained.

Further, in the laminated container 100 of the present embodiment, it is preferable that the glass transition temperature of the inner layer 110 is 30 ° C. or more higher than the glass transition temperature of the outer layer 120. With such a configuration, there is a difference in the ease of stretching when the laminated preform 1 is blow-molded to form the laminated container 100, and the inner layer 110 becomes difficult to stretch. As a result, the bottom portion 103c of the laminated container 100 becomes thick and can be molded into a high-class shape.

Further, the first synthetic resin constituting the inner preform 10 of the laminated preform 1 and the second synthetic resin constituting the outer preform 20 are obtained by blending one synthetic resin with a small amount of the other synthetic resin. You may use it. According to this, it is possible to improve the adhesiveness between the inner layer 110 and the outer layer 120 of the laminated container 100 after molding.

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 embodiment, the laminated preform 1 has a double structure composed of an inner preform 10 and an outer preform 20, but the present invention is not limited to this, and the inner and outer preforms 20 of the inner preform 10 are not limited to this. Another layer may be provided at least at any position on the outer side and between the inner preform 10 and the outer preform 20 to form a triple or more laminated structure. Similarly, the laminated container 100 may also have a triple or more laminated structure by providing another layer at least at any position inside the inner layer 110, outside the outer layer 120, and between the inner layer 110 and the outer layer 120.

Further, in the previous embodiment, the male screw portions 11a and 111a are provided on the mouth portions 11 and 111 so that a cap or the like having a female screw portion can be attached, but the cap or the like is provided on the cap instead of the male screw portions 11a and 111a. A concave portion or a convex portion or the like for engaging with the convex portion or the concave portion to fit and hold the cap may be provided. Further, the mouth portion 11 of this example is formed in a cylindrical shape having a circular cross section perpendicular to the axis O, but is not limited to this, and may be formed into a cylindrical shape having an elliptical or polygonal cross section, for example. good.

1: Laminated preform 10: Inner preform 11: Mouth 11a: Male thread 12: Inner body 13: Neck ring 14: Engagement recess 14a: Recess bottom surface 14b: Engagement surface 14c: Facing surface 20: Outer preform 21: Outer body 22: Inner flange 22a: Inner peripheral surface 22b: Lower surface 22c: Upper surface 100: Laminated container 103: Body 103a: Tube 103b: Shoulder 103c: Bottom 110: Inner layer 111: Mouth 111a: Male screw Part 112: Inner layer body 113: Neck ring 114: Engagement recess 114a: Recess bottom surface 114b: Engagement surface 114c: Facing surface 120: Outer layer 121: Outer layer body 122: Inner flange G: Gap M: Accommodation space O: Axis line

Claims (3)

A laminated preform having an inner preform and an outer preform,
The inner preform includes a tubular mouth portion having a neck ring at the lower end portion and a bottomed tubular inner body portion connected below the mouth portion.
The outer preform comprises an outer body portion that covers the inner body portion.
The inner flange portion provided at the upper end of the outer body portion is fitted into the engaging recess provided at the upper end of the inner body portion .
The engaging recess is continuously provided over the entire circumferential direction of the inner body portion, and the inner flange portion is continuously provided over the entire circumferential direction of the outer body portion. Laminated preform. The inner preform and the outer preform are composed of an amorphous synthetic resin.
The laminated preform according to claim 1, wherein the glass transition temperature of the synthetic resin constituting the inner preform is higher than the glass transition temperature of the synthetic resin constituting the outer preform. A laminated container having an inner layer and an outer layer,
The inner layer includes a tubular mouth portion having a neck ring at the lower end portion and a bottomed tubular inner layer body portion connected below the mouth portion.
The outer layer includes an outer layer body portion that covers the inner layer body portion.
The inner flange portion provided at the upper end of the outer layer body portion is fitted into the engaging recess provided at the upper end of the inner layer body portion .
The engaging recess is continuously provided over the entire circumferential direction of the inner layer body portion, and the inner flange portion is continuously provided over the entire circumferential direction of the outer layer body portion. Laminated container.

Images