JPH0688356B2 - Multi-layer hollow container with linear filament for see-through and multi-layer co-extrusion die head - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a plastic hollow container used as a packaging container for shampoos, liquid detergents, cosmetics and other liquid contents, and a die head for multi-layer coextrusion for the production thereof. It is a thing.

[Prior Art] As a packaging container for liquid contents such as shampoo, liquid detergent, cosmetics and the like, a plastic hollow container made of a colored resin is used.

[Problems to be Solved by the Invention] While such a colored resin hollow container has an aesthetic effect due to its beautiful color, it cannot see through the liquid level of the content, and the amount of the content in both the production stage and the consumption stage is high. There was an inconvenience that could not be seen from the outside.

In order to eliminate this drawback, it is conceivable to form a part of the circumference of the container using the colored resin into a vertical strip shape with another transparent resin, but in this case, the boundary surface between different resin flows is It will be formed by reaching from the inner surface to the outer surface in the thickness direction of the container wall, and in this part, the orientation of the molecules will be almost aligned with the height direction of the container, and there will be another problem such as decrease in strength and increase in oxygen permeability. The problem arises.

The present invention has been made in view of the circumstances as described above, and a color effect using an opaque colored resin of an arbitrary color and a see-through function capable of seeing through the liquid from the outside regardless of the height of the liquid level. It is also an object of the present invention to provide a multi-layer hollow container with a filament for see-through, which does not impair the barrier property against oxygen intrusion, and a die head for multi-layer co-extrusion that can be used for its production.

[Means for Solving the Problems] In order to achieve this object, a perspective-view multi-layer hollow container of the first invention is located between an inner layer and an outer layer, and between the inner layer and the outer layer, and the inner layer. And a plastic hollow having a peripheral wall of a multi-layer structure in which a light-transmitting barrier layer made of a resin having a smaller oxygen permeability than the outer layer is laminated, and a see-through line is formed on a part of the peripheral wall in the circumferential direction. A container,
In the perspective filament of the peripheral wall, at least one of the inner layer and the outer layer constituting the filament has a light transmittance higher than that of an adjacent portion, and the multilayer coextrusion die head of the second invention is A die head which is arranged upstream of an extrusion die for molding a hollow body and supplies a multilayer molten resin in which an inner layer resin, an intermediate layer resin and an outer layer resin are laminated in the annular slit of the extrusion die in the width direction of the annular slit. Wherein the inner layer resin, the intermediate layer resin, and the outer layer resin are provided with tube-shaped passages each having an annular cross section, and the inner layer resin passage is provided with the intermediate layer resin from the outside thereof. Of the outer layer resin is joined to form an annular confluent portion, and the passage of the outer layer resin is joined to the outer layer resin passage from the outside thereof at the downstream thereof. As an outer layer resin portion corresponding to at least a part of the circumference of the annular slit, another resin passage (A) capable of supplying a resin having physical properties different from the remaining outer layer resin portion is joined with the inner layer resin passage. At least one of further resin passages (B) capable of supplying a resin having physical properties different from those of the remaining inner layer resin portion is provided as an inner layer resin portion corresponding to the partial position on the circumference of the annular slit. I am trying.

[Operation] The multi-layer hollow container with a filament for see-through configured as described above is
Since the wall of at least a part of the circumference has a higher light transmittance than that of the adjacent part, by forming this part into a vertical linear shape extending over the entire height of the container, it is possible to penetrate through this part to externally see the liquid level. It makes it possible to see through the height, and it is possible to use a colored resin having a sufficient color effect for the inner layer resin and the outer layer resin instead of making it impossible to see through the remaining portion.

Moreover, in the linear part for see-through, the barrier layer having a small oxygen permeability among the resin layers constituting the wall is continuously formed continuously over the entire circumference.
Since the boundary surface in the wall thickness direction due to the welding of different resin flows as described above cannot be formed, the molecules in this portion are intricately oriented toward each other in a free direction almost perpendicular to the wall thickness direction, and this resin layer should originally have. Does not impair the oxygen barrier property.

Further, in the multilayer coextrusion die head configured as described above, the colored resin is continuously provided in the inner layer resin passage and the outer layer resin passage, and the resin having a small oxygen permeability is continuously provided in the intermediate layer resin passage. To at least one of the “other resin passage (A)” and the “further other resin passage (B)” of the multilayer coextrusion die head,
When a resin having a higher light transmittance than the colored resin is continuously supplied, the resin layer having a low oxygen transmittance is sandwiched between the inner resin layer and the outer resin layer in the annular slit of the hollow body molding extrusion die. Multilayer molten resin laminated is supplied,
What is important here is that at least a part of the circumference of the die, at least one of the inner layer resin layer and the outer layer resin layer has a higher light transmittance than the colored resin occupying the remaining portion, and therefore, from the die. In the extruded parison, a portion having a high light transmittance is continuously formed in a vertical line, and the intermediate layer is formed continuously along the entire circumference without a resin flow boundary surface. Therefore, the parison is blow-molded. Even in the hollow container that can be formed with, the filaments with a large light transmittance are formed vertically over the entire height of the container, and the intermediate layer is formed continuously over the entire circumference without a boundary surface of the resin flow to form a barrier layer against oxygen. A multi-layer hollow container with a filament for seeing through is formed.

[Embodiment] Hereinafter, details of the present invention will be described with reference to the drawings illustrating an embodiment.

In FIG. 1, FIG. 2 and FIG. 3, reference numeral 1 is a multi-layer hollow container with a filament for see-through.

The see-through multi-layer hollow container 1 is a plastic hollow container surrounded by a wall 6 having a multi-layer structure in which an inner layer 2, a barrier layer 4 and an outer layer 3 are sequentially laminated with an adhesive layer 5 interposed therebetween. Thus, a vertical linear strip 7 is provided on one side surface over the entire height of the container.

Here, the barrier layer 4 is made of a material having a low oxygen transmission rate-for example, EVOH (ethylene-vinyl alcohol copolymer)-, and the resin having a uniform composition extruded from a single extruder (not shown) as a whole. Due to this, the entire circumference is continuously formed seamlessly with different types of resin, and a phenomenon that tends to occur at the joints of different resin flows-the chains of molecules in both resin flows are clearly separated to both sides of the boundary surface and along the boundary surface It is molded so that it is not oriented and its strength is reduced or oxygen is easily transmitted there.

On the other hand, the constituent resins of the inner layer 2 and the outer layer 3 are different in the see-through line 7 and the remaining portion 8.

That is, in the remaining portion 8 occupying most of the container wall, both the inner layer 2 and the outer layer 3 are composed of an opaque colored resin 11-for example, a natural resin such as polypropylene or polyethylene colored white with titanium white. On the other hand, in the see-through line 7, the inner layer 2 and the outer layer 3 are made of a natural resin 12 that is the same material as the colored resin 11, that is, polypropylene or polyethylene, and the see-through line 7 portion has a container content from outside. It is possible to see through the liquid level.

Regarding the cross-sectional shape of the layer of the natural resin 12 forming the see-through filaments 7, the inner layer 2 and the outer layer 3 are as shown in FIG.
In both cases, the appearance can be improved by slightly inclining the boundary 13 with the layer of the colored resin 11 in a direction that is difficult for the see-through person to see with respect to the thickness direction.

In the multi-layer hollow container 1 with the see-through filaments described above, a layer of the natural resin 12 is formed on both the inner layer 2 and the outer layer 3 of the see-through filaments 7. As shown in the multi-layer hollow container 1a with see-through filaments, see-through filaments 7a
Only one of the inner layer 2a and the outer layer 3a of the
It is also possible to form only 3a.

Next, the multi-layer coextrusion die head will be described.

In FIG. 6 and FIG. 7, 21 is a die head for multilayer coextrusion. The multi-layer co-extrusion die head 21 is disposed upstream of the extrusion die 22 for hollow body molding and enters the annular slit 23 of the extrusion die 22, as shown in FIG. 10, the inner layer resin 24, the intermediate layer resin 25 and the outer layer. The resin 26 is the width direction 27 of the annular slit 23.
It is for supplying the multilayer molten resin 28 laminated on the. The multi-layer molten resin 28 is for blow-molding the multi-layer molten resin 28 to obtain the multi-layer hollow container 1 with a see-through filament, and the inner layer resin 24a and the outer layer resin 26a on one side of the circumference are respectively The remaining portions 24b and 26b are made of a material having a higher light transmittance than that of the resin, for example, the natural resin 12.

The multi-layer coextrusion die head 21 includes an inner layer resin passage 31, an adhesive resin passage 32, an intermediate layer resin passage 33, and an adhesive resin passage 34.
And a passage 35 for the outer layer resin, each of which is configured as a tube type having an annular cross section. That is, the multilayer co-extrusion die head 21 is provided with a cylindrical spider 36 at the center, and cylindrical sleeves 37, 38, 40, 41 and an outer die 42 which are sequentially coaxial with each other outside the spider 36. Has flanges 43,44,45,46,47 at the top at the top,
These flanges are sequentially stacked and fitted so that the upper surface of the former contacts the lower surface of the former, and the flange 47 of the lowermost layer overlaps the upper surface of the outer mold 42 to define the mutual positional relationship in the radial direction. As a result, the passages 31, 32, 33, 34, 35 are formed as gaps having an annular cross section in the lower portion having a slightly smaller outer diameter than the upper portion.

The lower end portions 32a, 33a, 34a, 35a of the passages 32, 33, 34, 35 are inclined inward and downward and open to the outer periphery of the spider 36, respectively.

That is, the lower end portion 32a joins the passage 31 from the outside to form an annular joining portion on the outer circumference of the spider 36, and the downstream lower end portion 33a joins to form an annular joining portion on the outer circumference of the spider 36 downstream thereof. , Similarly, at its downstream end 34a
However, the lower end 35a at the downstream of the spider 3
An annular merging portion is formed on the outer periphery of 6 to join all of these passages 3
The merging passage downstream part 48 where 1,32,33,34,35 have merged forms an annular tube type in a transverse cross section on the outer periphery of the lower part of the spider 36,
Then, the diameter of the tube is reduced along the taper portion 36a at the lower end of the spider 36 with the tube shape having an annular cross section, and the extrusion die 22
It is designed to reach the inside of the annular slit 23.

At the upper end of each passage 31, 32, 34, 35, the inner wall surface of each passage protrudes inward in a semicircular arc shape in the vertical cross section (that is, the outer surface of the inner sleeve or spider that constitutes the inner wall surface of each passage makes one round). A groove having a semi-circular cross section is formed) to form an annular resin supply passage 51, 52, 53, 54. Each of these resin supply passages has a linear resin supply passage 51a at one location on its circumference. , 52a, 53
a and 54a are connected, which are also connected to respective extruders (not shown).

Similarly, the upper end of the passage 33 also forms the resin supply passage 50,
50 is connected to another extruder (not shown).

At the upper end of the resin passages 31 and 35 and at a position 180 ° opposite to the connection point with the resin supply passages 51a and 54a, the other resin supply passages 55 are provided.
(B) and 56 (A) merge, and they can supply resin from another extruder (not shown) to the passages 31 and 35.

The configuration of the junction between the resin passage 35 and the resin supply passage 56 (A) is the eighth.
Shown in Figures and 9. That is, the merging portion is provided with a guide wall portion 57, and the guide wall portion 57 is provided so as to be connected to the tip of the pipe body 58 forming the resin supply passage 56, and the resin flow from the resin supply passage 56 is The outer surface 57a is curved so as to face the resin supply passage 54 and the resin passage 35, and defines the position of the passage 35 in the upper end portion 35b and the cross-sectional shape. It is configured to smoothly change from the direction 61 in the supply passage 54 to the direction 62 in the resin passage 35, while the inner surface 57b is connected to the inner surface of the tubular body 58 and the resin supplied in the resin supply passage 56. So that it is fed in the direction 62 (see FIG. 8), its lower end is parallel to the direction 62 and is obliquely inward as shown in FIG.

The structure of the junction between the resin passage 31 and the resin supply passage 55 (B) is
The structure is the same as the structure of the confluent portion between the resin passage 34 and the resin supply passage 56 described above.

When the multi-layer molten resin 28 is formed using the multi-layer coextrusion die head 21 configured as described above, the resin supply path 51a,
54a is supplied with a colored resin, the resin for the barrier layer is supplied to the resin passage 50, the adhesive resin 10 is supplied to the resin supply passages 52a and 53a, and a material having a high light transmittance from the resin supply passages 55 and 56, For example, natural resin may be supplied.

In order to mold the multi-layer hollow container 1a with a filament for see-through,
The multilayer coextrusion die head 21a shown in FIGS. 11 and 12 is used. The multi-layer coextrusion die head 21a has an inner layer resin passage 31.
The resin supply passage 55 that joins with is missing.

[Effects of the Invention] According to the multilayer coextrusion die head 21 configured as described above, the multilayer molten resin in which different resin flows are seamless in the intermediate layer is provided.
No. 28 can be obtained, and by forming the intermediate layer from a resin having a low oxygen permeability, the multilayer hollow container 1 with a filament for seeing obtained by blow molding this does not impair the oxygen barrier effect. .

As is apparent from the above description, according to the present invention, the color effect using the opaque colored resin of any color and the transparent function of seeing through the liquid from the outside at any height of the content liquid surface are combined, and It is possible to obtain a multi-layer hollow container with a filament for see-through and a multi-layer co-extrusion die head that can be used for manufacturing the same, without impairing the barrier property against oxygen invasion.

[Brief description of drawings]

FIG. 1 is a front view showing a multi-layer hollow container with perspective filaments according to an embodiment of the present invention, and FIG. 2 is a cross-sectional end face explanatory view of the multi-layer hollow container with perspective filaments shown in FIG. 3 is an enlarged view of a portion C in FIG. 2, FIG. 4 is an explanatory view of a cross-sectional end face of a multi-layer hollow container with a see-through filament according to another embodiment of the present invention, and FIG. 5 is a portion D in FIG. FIG. 6 is an enlarged view, FIG. 6 is an explanatory longitudinal sectional view showing a multilayer coextrusion die head according to an embodiment of the present invention, FIG. 7 is a plan view of the multilayer coextrusion die head shown in FIG. 6, and FIG. 8 is an outer layer. FIG. 9 is a vertical cross-sectional explanatory view of the inside of the confluence of the resin passage and the resin passage (A) taken along a tangential surface, and FIG. 9 is a sectional view taken along line IX-IX in FIG.
FIG. 0 is a cross-sectional explanatory view showing a multilayer molten resin formed by the multi-layer co-extrusion die head shown in FIG. 6, and FIG. 11 is a multilayer for forming the see-through linear multi-layer hollow container shown in FIG. FIG. 12 is a longitudinal sectional view showing the co-extrusion die head, and FIG. 12 is a plan view of the multilayer co-extrusion die head shown in FIG. 1 ... Multi-layer hollow container with a filament for see-through, 2 ... inner layer, 3 ... outer layer, 4 ... barrier layer, 5 ... adhesive layer, 6 ... wall, 7 ... filament for see-through, 8 ... Remaining part, 10 …… Adhesive resin, 11 …… Colored resin, 12 …… Natural resin, 12 …… Border, 21 …… Multilayer coextrusion die head 22 …… Extrusion die, 23 …… Circular slit, 24 …… Inner layer resin, 25 …… Middle layer resin, 26 …… Outer layer resin, 27 …… Width direction, 28 …… Multilayer molten resin, 31 …… Inner layer resin passageway, 32 …… Adhesive resin passageway, 33 …… Intermediate layer resin passageway , 34 …… Adhesive resin passage, 35 …… Outer layer resin passage, 35a …… Lower end, 35b …… Upper end, 36 …… Spider, 36a …… Tapered portion, 37,38,40,41 …… Sleeve, 42 ...... Outer mold, 43,44,45,46,47 ...... Flange, 48 ...... Downstream of confluence passage, 50,51,52,53,54,56 …… Resin supply passage, 57 …… Guide wall, Five
7a …… outer surface, 57b …… inner surface, 58 …… tube, 61 …… direction

Claims (2)

[Claims] 1. A multi-layer comprising an inner layer and an outer layer, and a translucent barrier layer which is located between the inner layer and the outer layer and which is made of a resin having a smaller oxygen permeability than the inner layer and the outer layer. A plastic hollow container having a peripheral wall of a structure and having a perspective line formed on a part of the peripheral wall in the circumferential direction,
In the perspective filament of the peripheral wall, at least one of the inner layer and the outer layer constituting the filament has a light transmittance higher than that of an adjacent portion, and the multi-layer hollow container with the filament for perspective is characterized. 2. A multi-layer molten resin which is disposed upstream of an extrusion die for molding a hollow body and in which an inner layer resin, an intermediate layer resin and an outer layer resin are laminated in the annular slit of the extrusion die in the width direction of the annular slit. A die head for supplying the inner layer resin, the intermediate layer resin, and the outer layer resin, each of which is provided with a tube-shaped passage having an annular cross section, and the inner layer resin passage is provided from the outside thereof. The intermediate layer resin passages form an annular merging portion, and downstream thereof, the outer layer resin passages form an annular merging portion, and join the outer layer resin passages. As an outer layer resin portion corresponding to at least a part of the circumference of the annular slit, another resin passage (A) capable of supplying a resin having physical properties different from the remaining outer layer resin portion and the inner layer resin passage are joined. Further, at least one of the other resin passages (B) capable of supplying a resin having physical properties different from the remaining inner layer resin portion is provided as the inner layer resin portion corresponding to the partial position on the circumference of the annular slit. Characteristic multi-layer coextrusion die head