JPH02139327A - Hollow labeled container and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a hollow labeled container with the label provided fast on an outer periphery of a body by providing a film base label on a plastic container provided with a three-dimensional pattern or structure on the outer periphery of the body by internal label operation. CONSTITUTION:A label 1 consists of a plastic film base 2 and a printed layer 3 provided on the outer surface of said base. The plastic film base 2 may be either a single-layer film or a multilayer film, but the outer face is thermal- adhesive to a plastic container. A bottle-type container 10 is provided with the label 1 on a body 11 including a relief pattern 14 by internal label operation. The label 1 is rigidly coupled to the container body 11 on a whole area, while an outer surface 20 of the label 1 and an outer surface 21 of the container body, that is, the outer surface 21 except a label applied portion are leveled without substantial difference in height.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a hollow container with a label and a method for manufacturing the same, and more particularly relates to a hollow container made of plastic having a three-dimensional pattern or structure on the outer peripheral surface of the body. The present invention relates to a container in which a label with excellent beauty, durability, and peeling resistance is attached to the three-dimensional portion of the container, and a method for producing the same.

(Conventional technology) Plastic hollow containers are lightweight and have excellent impact resistance, so they are used for various foods, toiletry products, cosmetics, etc.
Widely used for packaging drugs, etc.

BACKGROUND OF THE INVENTION Various types of printing and labeling have been performed on plastic containers for a long time in order to display the contents or to increase their commercial value. This printing and labeling is generally performed on a smooth surface portion of the container body. It is already known that the label is attached simultaneously with the hollow molding of the container in a container molding die, which is called an in-mold label.

(Problems to be Solved by the Invention) However, if it becomes possible to attach a label to a part other than the planar part of the container body, it will improve the aesthetics and commercial value of the packaging container, and the functionality of the container. Significant benefits are expected.

For example, it is common practice to print a mark indicating the brand on a packaging container or to attach a label with this mark printed on it, but if this mark is made into a three-dimensional relief pattern, It is expected that the aesthetic appearance and product value will be improved compared to other products.

In addition, packaging containers may be required to have a three-dimensional structure on the body due to their intended use or required functionality. This includes a bellows structure that facilitates deformation, and a pillar and panel structure that prevents deformation during cooling after hot filling. Even in these cases, if the label is attached to the three-dimensional structure, it is expected that there will be an advantage that a large display area can be secured without impairing the original function of the container.

Therefore, an object of the present invention is to provide a hollow plastic container having a three-dimensional pattern or structure on the outer peripheral surface of the body.
To provide a labeled hollow container in which a beautiful, durable and peel-resistant label is firmly attached to the outer periphery of the body including the three-dimensional portion, and a method for manufacturing the same.

Another object of the present invention is to provide a method for producing a labeled hollow container in which the above-mentioned label can be easily attached by an in-mold label operation.

(Means for Solving the Problems) According to the present invention, there is provided a hollow container made of plastic having a three-dimensional pattern or structure on the outer circumferential surface of the body, and at least the inner surface made of plastic, which is visible from the outer surface. a film-based label integrally bonded to the container body, the label having a printing layer capable of forming A labeled hollow container is provided, which is characterized in that there is no substantial step difference therebetween.

According to the present invention, a film-based label having at least the inner surface made of plastic and having a printing layer visible from the outer surface can be used to form a three-dimensional pattern or structure on the outer peripheral surface of the body. A label is attached to the cavity surface of a blow mold containing the three-dimensional part, and a single or multi-layer plastic parison is introduced into the blow mold to blow mold the container and at the same time a label is attached to the body of the container containing the three-dimensional part. A method for manufacturing a labeled hollow container is provided.

(Function) The present invention provides that when manufacturing a plastic hollow container having a three-dimensional pattern or structure on the outer circumferential surface of the body, when a film-based label is applied by an in-mold label operation, the three-dimensional shape described above can be created. This is based on the knowledge that it is possible to attach labels with excellent beauty, durability, and peel resistance while faithfully expressing the pattern or structure.

A container having a three-dimensional pattern or structure on the outer peripheral surface of the body is made by pressurizing a plastic parison in a molten or softened state in a mold (split mold) having a cavity surface portion corresponding to the pattern or structure. It is obtained by expanding the plastic by blowing fluid into it, making contact with the cavity surface of the mold, and cooling it. The molded container is removed from the mold by opening the mold. The in-mold label operation is carried out prior to blow molding of the parison by holding the label on the cavity surface including the cavity surface portion and allowing the expanded molten plastic parison to come into contact with the label to promote thermal bonding. .

In the present invention, by using a film-based label with at least the inner surface made of plastic, the plastic of the container body and the plastic of the inner surface of the label can faithfully express a three-dimensional pattern or structure, and It ensures good thermal bonding over the entire surface of the pattern or structure, resulting in a strong bond over the entire surface of the label. This acts as a kind of insulating layer when the plastic film of the label comes into contact with the expanded molten container body, allowing the plastic parison to remain molten and forming the label into a three-dimensional pattern or structure. This is thought to be due to the fact that the film acts as a pressurizing medium and the temperature of the inner surface of the film becomes a high-temperature molten state, so that thermal adhesion progresses reliably over the entire surface.

This fact will become readily apparent by reference to FIG. 1 of the accompanying drawings. Figure 1 shows the elapsed time and temperature of the outer surface of the film (mold side) and the inner surface of the parison when a polypropylene parison is blow-molded by attaching a label film to the cavity surface of a mold. This is a plot of the relationship between From this figure 1, the maximum temperature reached on the inside side is 175°C, while the maximum temperature reached on the outside side is 50°C, and the time it takes to reach the maximum temperature is longer on the inside side than on the outside side. The fact that it is early becomes clear.

Thus, according to the present invention, the film used for the label acts as a heat insulating layer during in-mold labeling, so that the label can be formed into a predetermined three-dimensional pattern or structure first by isotropic pressure transmission of the molten plastic. Moreover, the inner surface of the film is melted or thermally activated by the small amount of heat contained in the container body, thereby creating a strong bond between the container body and the label.

Next, when a label is attached to the container body by an in-mold label operation, there is obtained a feature that there is virtually no difference in level between the outer surface of the body and the outer surface of the label, and both surfaces are flush with each other. When considering the adhesive structure between the label and the container body, the weakest part of this adhesive structure is the edge of the label, and adhesive failure occurs from this edge, causing peeling. On the other hand, in the present invention, since the outer surfaces of both labels are flush with each other, it is understood that stress concentration is less likely to occur at the edge of the label, and adhesive failure and peeling are less likely to occur.

Moreover, since the label used in the present invention is based on a continuous and thin film, it can be formed into a three-dimensional pattern or structure due to the flexibility, flexibility, freedom, etc. of the film. Furthermore, once the container is made into a labeled container, even if the label attachment part is deformed, the film itself will not be damaged due to its flexibility, flexibility, freedom, etc., and its durability will be reduced. Are better. Furthermore, since the film has excellent smoothness and continuity, the printed image printed on it has excellent sharpness, resolution, contrast, density, etc., and is beautiful and has the effect of increasing commercial value.

(Preferred Embodiment of the Invention) The label used in the present invention may have any layer structure as long as it is based on a film and has a printed layer.

Some examples of such labels are shown in Figures 2-A to 2-H. In Figure 2-A, the label 1 consists of a plastic film substrate 2 and a printed layer 3 applied to its outer surface. The plastic film substrate 2 may be a single-layer film or a multi-layer film, but the outer surface must be thermally adhesive to the plastic container. The label 1 of FIG. 2-B is similar to that of FIG. 2-A, except that a protective overcoat layer 4 is provided over the printed layer 3. As the overcoat layer 4, a transparent resin coat layer is used. In the label 1 shown in FIG. 2-C, an adhesive resin layer 5 exhibiting thermal adhesive properties is applied to the inner surface of a film base material 2 by means of coating or the like. The label 1 of Figure 2-D has an overcoat layer 4 on top of the printed layer 3 of Figure 2-C.
is provided. In the label 1 shown in FIG. 2-E, a printing layer 3 is applied on the inner surface side of a film base material 2 as so-called back printing, and an adhesive resin layer 5 is provided on this printing layer 3. FIG. 2-F shows the label of FIG. 2-E in which an overcoat layer 4 is provided on the outer surface side of the film base material 2. The label 1 shown in Fig. 2-G includes a printed layer 3 on the inner surface of a film base material 2, a thin metal layer 6 formed by vapor deposition, etc., and an adhesive resin layer 5 on top of the printed layer 3. . This thin metal layer 6 serves to impart a metallic luster to the printed layer. FIG. 2-H shows the label of FIG. 2-G in which an overcoat layer 4 is provided on the inner surface side of the film base material 2. The laminated structure of the label used in the present invention is, of course, not limited to those exemplified above.

Plastics constituting the film base material include, for example, crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene-1, crystalline poly-4-methylpentene-1, low-medium or high-density polyethylene, and ethylene. - Polyolefins such as vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and ionically crosslinked olefin copolymer (ionomer);
Aromatic vinyl polymers such as polystyrene and styrene-butadiene copolymers; halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resins; nitrile polymers such as acrylonitrile-styrene copolymers and acrylonitrile-styrene-butadiene copolymers Coalescing; Polyamides such as nylon 6, nylon 6.6, para- or meta-xylylene adipamide; Polyesters such as polyethylene terephthalate and polytetramethylene terephthalate; Various polycarbonates; Thermoplastic resins such as polyacetals such as polyoxymethylene can be mentioned. These film base materials may be unstretched, or may be axially or biaxially stretched, and this film may be a normal transparent film, a slightly foamed film, It may also be a translucent to opaque film containing fillers or pigments. The thickness of the film base material is generally suitably in the range of 20 to 300 um, particularly 50 to 150 um.

The ink forming the printing layer is a vehicle of a known ink used in film printing, such as polyester urethane, vinyl urethane, acrylic urethane, epoxy urethane, epoxy vinyl, epoxy acrylic, chlorinated polypropylene, etc., and a coloring agent. An ink containing

Printing can be performed by means such as offset printing, gravure printing, letterpress printing, electrophotographic printing, hot stamping, etc.

This is not particularly necessary if sufficient thermal adhesion can be obtained directly between the film used for the label and the plastic on the outer surface of the container during blow molding. It is best to thermally bond the container to the outer plastic wall of the container. Such hot melt adhesive resins include ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 5 to 40% by weight, and ethylene-ethyl acrylate copolymer having an acrylic acid content of 5 to 40% by weight. (EEA), low density polyethylene (LDPE), EVA, EEA, etc., or these resins with 5 to 30 weight of tackifier such as rosin, terpene resin, petroleum resin, styrene resin, etc. % is used. The hot melt adhesive resin is generally applied on the base film in an amount of 3 to 40 μm, especially 5 to 15 μm.
It is preferable to provide it with a thickness of μm.

As the overcoat layer, resins with excellent transparency and scratch resistance, such as nitrocellulose, acrylic resin, acrylic-vinyl paint, acrylic-phenol paint, acrylic-amino paint, etc., are used. The overcoat layer is generally preferably provided with a thickness of 1 to 20 μm, particularly 2 to 10 μm. The thin metal layer can be provided by vapor deposition or hot stamping (transfer) of a metal such as aluminum, and its thickness is generally from 0.005 to 15 μm, in particular from 0.005 to 15 μm.
The thickness is preferably in the range of 0.01 to 10 μm.

The plastic container body according to the present invention has a three-dimensional pattern or structure on the outer peripheral surface of the body. Three-dimensional shape literally means that the outer surface changes in a direction perpendicular to the surface direction to form a pattern or structure.

In Figures 3-A and 3-B showing an example of this hollow container, a bottle-shaped container 10 has a body 11, a closed bottom 12 extending below the body, and a mouth portion extending to the upper part of the body via a shoulder 13. It consists of 9. The body 11 has an outwardly projecting relief pattern 14. The label 1 including the relief pattern 14 is applied to the body 11 by an in-mold label operation. In FIG. 3-B showing this cross-sectional structure, the label 1 is firmly connected to the container body 11 over its entire surface, but the outer surface 20 of the label 1 and the outer surface 21 of the container layer, that is, the label is attached There is virtually no difference in level between the outer surface 21 outside the component and the outer surface 21 is flush with the outer surface 21 of the component. That is, the edge portion 22 of the label 1 is embedded within the container body 11 to prevent curling or the like due to stress concentration on the edge portion. In this example, the label 1 includes an image area 26 corresponding to the relief pattern 14 and a background area 27.
By having the relief pattern 14 and the image portion 26 coincide with each other, a distinctive relief pattern can be produced. If the image portion 26 is formed of a metal such as gold or silver or a conspicuous color such as red, the decorative effect will be great.

4-A and 4-B are examples of containers in which beads 15 for reinforcement and decoration are formed on the outer periphery of the container body 11. In this case, the outer periphery of the body including the bead 15 is also shown. Label 1 is similarly connected to .

Figures 5-A, 5-B, and 5-C show that a structure of pillars 16 and panels 17 is provided on the outer periphery of the body 11 for the purpose of preventing asymmetric deformation of the container due to cooling after hot filling. In this example, the internal pressure is compensated by the panel 17 being deformed into irregularities. In this example, pillar 16
The label 1 is firmly connected to the outer periphery of the body including the panel 17.

6-A and 8-B show a bellows structure in the body 11, that is, a large diameter part 18 and a small diameter part 19 are provided alternately in the axial direction so that the contents can be easily extruded. It is. In this example as well, the label 1 including the bellows structure is firmly connected.

The container body 10 of the present invention can be made of the resin mentioned for the label film base material, such as a single layer of polyolefin, a single layer of polyester, etc., but from the viewpoint of preserving the contents, moisture-resistant resin and oxygen permeation-resistant resin are preferred. It is preferable to have a laminated structure with a synthetic resin. In FIG. 7, which shows an example of a multilayer structure of a container, this container 10 includes an oxygen barrier thermoplastic resin intermediate layer 23, and moisture-resistant thermoplastic resin inner and outer layers 24a.
, 24b and adhesive resin layers 25a and 25b inserted between both resins as necessary.

In the present invention, in terms of the preservability and aroma retention of the contents, the oxygen permeability coefficient (PO2) is 5.5
/cm”, sec-cmHg (37°C, 0%RH) or less, especially 4.5 x 10-” cc-cI++/cm
2. It is desirable to use a single thermoplastic resin or a blend of resins in an amount of 1 g or less (seclcm) as the oxygen barrier resin.

The most preferred example of such a resin is an ethylene-vinyl alcohol copolymer, particularly one having a vinyl alcohol unit content of 40 to 85 mol%, particularly 50 to 80 mol%. Such ethylene-vinyl alcohol copolymers consist of a combination of ethylene or a large portion of ethylene with minor components of other olefins such as propylene, and vinyl esters of lower fatty acids such as vinyl formate, vinyl acetate, and vinyl propionate. Polymers, especially ethylene-vinyl acetate polymers, have a saponification degree of 96% or more, especially 9
It can be obtained by saponification to a concentration of 9% or more.

Other examples of oxygen barrier resins include nylon resin,
Especially nylon 6, nylon 8, nylon 11, nylon 12, nylon 6/6, nylon 6/10, nylon 1
0.6 or nylon 6-.6.6 copolymer.

Furthermore, high nitrile resins, vinylidene chloride resins, vinyl chloride resins, etc. may also be used for the purpose of the present invention.

The oxygen barrier resin can be used in the form of a so-called blend, for example, a blend of an ethylene-vinyl alcohol copolymer and a nylon resin, or a blend of an ethylene-vinyl alcohol copolymer and a nylon resin. , other resins such as polyethylene, ethylene-vinyl acetate copolymers, or blends with ionomers may also be used for the purposes of this invention, provided their oxygen permeability coefficients are within the ranges mentioned above.

As the moisture-resistant thermoplastic resin, olefin resins such as low-medium density or high-density polyethylene polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and ionomer are preferably used.

If there is no interlayer adhesion between the oxygen barrier resin and the moisture resistant resin, an adhesive layer is interposed between both resin layers.

As the adhesive resin (C), any resin that exhibits adhesiveness to both the oxygen barrier thermoplastic resin (A) and the moisture-resistant thermoplastic resin (B) described above can be used. Generally, the adhesive resin (C) to be used is a carbonyl group (based on a functional group such as a ti-releasing carboxylic acid, a carboxylic acid salt, a carboxylic acid ester, a carboxylic acid amide, a carboxylic acid anhydride, a carbonate ester, urethane, or urea). -C-)
Thermoplastic polymers containing groups or blends of these polymers with other thermoplastic polymers are used. The carbonyl group concentration in these thermoplastic polymers can vary, but generally the carbonyl group concentration is 10 to 1400 mmol/100 g polymer, particularly 30 to 1200 mmol/100 g polymer.
A concentration of 100 g of polymer is desirable. Suitable adhesives include polyolefins modified with ethylenically unsaturated monomers of at least one of unsaturated acids, carboxylic acids, acid anhydrides, esters, amides, etc., especially maleic acid, acrylic acid, methacrylic acid, croton. Acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride,
Polypropylene modified with citraconic anhydride, ethyl acrylate, methyl methacrylate, ethyl maleate, 2-ethylhexyl acrylate, acrylamide, methacrylic acid amide, coconut oil fatty acid amide, maleimide, etc., high density polyethylene, low density・Polyethylene, ethylene-vinyl acetate copolymer, etc., and ethylene-vinyl acetate copolymer, etc.
These include acrylate copolymers, ionomers (Surlyn A manufactured by DuPont), polyalkylene oxide/polyester block copolymers, carboxymethyl cellulose derivatives, and blends of these with polyolefins. Incidentally, among these resins, those having a low carbonyl group content can themselves be used as moisture-resistant resins.

The body of the container of the present invention generally has a diameter of 100 to 300
It is preferable to have a thickness of 0 μm, especially 200 to 1000 μm.

In FIG. 8 for explaining the in-mold label operation, in step A, prior to blow molding the plastic parison, the blow molds 30a and 30b are in an open state,
A label 1 is applied in advance to a portion 31 on the surface of at least one of these cavities where a three-dimensional pattern or structure is to be formed. That is, the cavity surface 31 has a part that supports the label 1, and this part is provided with a decompression suction mechanism 32, and the label 1 is sucked into the cavity surface 3.
It is held at 1. In this case, the label should be positioned so that the plastic is on the inside. Cavity surface 3 of label 1
Application and fixation to 1 are not limited to suction, but can also be carried out, for example, by electrostatic electricity.

Next, in step B, the molten plastic parison 34 is extruded from the die 33, and blow molds 30a, 30b are formed.
is closed, and pressurized gas is blown into the closed parison 34.

In step C, the parison expanding in the mold is held on the mold surface and pressed against the label 1 to bring them into close contact, and the expanded parison comes into contact with the mold surface and is cooled, forming the labeled container 10. becomes.

Blow molding is performed using any blow molding method such as direct blow molding using a horizontal rotary blow molding machine or vertical rotary blow molding machine, as well as injection blow, two-stage blow molding, sheet forming, stretch blow molding, etc. be able to.

(Effects of the Invention) According to the present invention, a film-based label is attached to a plastic container having a three-dimensional pattern or structure on the outer periphery of the body.
When applied by in-mold label operation, the three-dimensional pattern or structure can be faithfully expressed due to the heat insulating effect of the film, while making it possible to bond the label surface and the container body through strong thermal bonding. Ta. In addition, the outer surface of the label and the outer surface of the container body were flush with each other without a step difference, and stress concentration on the edge of the label was released, resulting in excellent peeling resistance.

Furthermore, by using a film-based label, the flexibility, flexibility, freedom, etc. of the film means that the label itself will not be damaged and has excellent durability. Furthermore, because the film has excellent smoothness and continuity, the printed images printed on it have excellent clarity, resolution, contrast, density, etc., making it possible to improve the beauty and product value. .

(Example) The invention is illustrated by the following example.

Example 1 A star-shaped design was printed on one side of a 1100 u thick heat-shrinkable biaxially stretched film made of an ethylene-propylene random copolymer with a melting point of 137°C, and chlorinated polypropylene 50 A sealant consisting of a blend of 50 parts by weight of ethylene-vinyl acetate copolymer was applied.

Next, a rectangular label with a length of 80 mm and a width of 60 mm is punched out from the obtained label base material, and a rectangular label with a length of 80 mm and a width of 60 mm is punched out. It was attached to a bottle made of high-density polyethylene with the shape shown in the figure. In this case, the molten resin temperature of the high-density polyethylene parison was 220°C, and the blow mold temperature was 9°C.
It was ℃. Furthermore, the temperature of the label adhesive surface during blow molding reached a maximum of 175°C.

The appearance of the star-shaped relief portion of the in-mold label bottle body thus obtained was very good, the label adhered to the curved surface of the relief, and no flaking or wrinkles were observed.

Examples 2 to 4 Using the same label material and bottle material as in Example 1, the process shown in FIG. 4 (Example 2) was carried out as shown in FIG.
, In-mold label bottles having shapes as shown in FIG. 5 (Example 3) and FIG. 6 (Example 4) were molded.

The label follows the three-dimensional curved surface of the in-mold label bottle shoulder obtained in this way very well.
No wrinkles or wrinkles were observed.

Examples 5 to 8 In-mold label bottles having the shape shown in FIG. 3 were molded in the same manner as in Example 1 using various label materials and bottle materials shown in Table 1. The appearance of the resulting bottle was very good, the label adhered to the curved surface of the star-shaped relief, and no flaking or wrinkles were observed.

[Brief explanation of the drawing]

Fig. 1 is a diagram plotting the temperature of the label surface and the mold surface when the in-mold label of the present invention is attached to a bottle in relation to the elapsed time, and Fig. 2 shows the temperature of the label surface and the mold surface when the in-mold label of the present invention is attached to a bottle. 3 is a diagram showing an example of a cross-sectional structure, FIG. 3 is a diagram showing an example of a container having a three-dimensional relief pattern on the outer peripheral surface of the container body of the present invention, and FIG. 4 is a diagram showing an example of the container body of the present invention. FIG. 5 is a diagram showing an example of a container in which a bead is formed on the outer periphery of the container body, and FIG. FIG. 6 is a diagram showing an example of a container in which a bellows structure is provided in the container body of the present invention to facilitate extrusion of contents, and FIG. 7 is a diagram showing an example of a container body of the present invention. FIG. 8 is a diagram illustrating an example of a cross-sectional structure of the in-mold label, and FIG.
3 is a printing layer, 4 is an overcoat layer, 5 is an adhesive resin layer, 6 is a thin metal layer, 10 is a container with a label, 14 is a relief pattern, I5 is a bead, 16 is a pillar, 17 is a panel,
30 is a blow mold, 31 is a cavity surface, 32 is a vacuum suction mechanism, 33 is a die, and 34 is a parison.

Claims (2)

[Claims] (1) A hollow container made of plastic that has a three-dimensional pattern or structure on the outer peripheral surface of the body, and a container body that is made of plastic at least on the inner surface and has a printed layer that can be seen from the outside. an integrally bonded film-based label, the label having at least a three-dimensional pattern or structure and having no substantial step between the outer surface of the body and the outer surface of the label. Features a hollow container with a label. (2) A blow mold that includes a part for forming a three-dimensional pattern or structure on the outer peripheral surface of the body of a film-based label whose inner surface is made of plastic and has a printing layer that is visible from the outer surface. A single-layer or multi-layer plastic parison is introduced into the blow mold to blow-mold the container, and at the same time, the label is bonded to the body of the container including the three-dimensional portion. A method for producing a hollow container with a label.