JP6422788B2 - Overlap film and package - Google Patents

Description

  The present invention relates to an overlap film or the like that is coated on an adherend by heat shrinkage.

The overlap film is one type of packaging material that covers and attaches to an adherend such as a container in which food or the like is placed or a daily article by heat shrinkage. For example, many instant noodle-containing cup containers are covered and wrapped with an overlap film provided with a design printing layer such as a pattern, a trademark, or a description of a product.
In a mechanical manufacturing process, a package in which an adherend is packaged with an overlap film is generally manufactured as follows. A long overlap film is formed in a cylindrical shape so as to wrap the adherend, and both ends along the MD direction (longitudinal direction) are heat-sealed to wrap the adherend and form a tubular shape. After sealing and sealing the scale-like overlap film in the TD direction on both the front and back sides of the adherend, the shrink film is heat-shrinked by heating the overlap film containing the adherend inside and sealed on the three sides. Thus, a package is obtained.

By the way, an overlap film using a heat-shrinkable polyolefin film is known. Since the polyolefin-based film has low printability, when a design printing layer is provided on the heat-shrinkable polyolefin-based film, corona discharge treatment is performed as a surface treatment in order to improve printability.
Although the corona discharge treatment reduces the heat sealability of the film, it is difficult to perform the corona discharge treatment except for only the portion of the film that is heat sealed.
Patent Document 1 discloses that a design print layer is formed on a heat-shrinkable polyolefin film that has not been surface-treated using an ink containing a chlorinated polyolefin resin.

However, a design print layer containing a chlorinated polyolefin resin as a binder resin may cause cracks when the overlap film is heat-shrink mounted on the adherend. In particular, when this overlap film is heat shrink-fitted to a cup container containing instant noodles, the overlap film strongly adheres to the flange part of the cup container, so that the design print layer has cracks corresponding to the edges of the flange part. Prone to occur.
When the crack is generated in the design print layer, a design omission part is visible in the original design, so that the commercial value is impaired and improvement is required.

JP 2006-231852 A

  An object of the present invention is to provide an overlap film and a package on which the film is attached, in which cracks are not likely to occur in a design print layer even when heat shrinkage is attached.

  The overlap film of the present invention includes a heat-shrinkable polyolefin film, an anchor coat layer laminated on the back surface of the heat-shrinkable polyolefin film and containing a chlorinated polyolefin resin, and laminated on the back surface of the anchor coat layer. And a design printing layer containing a urethane-based resin, and a second printing layer laminated on the back surface of the design printing layer and containing a urethane-based resin and an inorganic pigment.

In a preferred overlap film of the present invention, the second printed layer contains titanium oxide.
The preferable overlap film of this invention has the area | region where the back surface of the film was exposed in the outer peripheral part of the said heat-shrinkable polyolefin-type film.

According to another aspect of the present invention, a package is provided.
The package of the present invention includes the overlap film, a container having a container main body and a flange portion projecting radially outward from the container main body, the anchor coat layer, the design layer, and the second printing. The overlap film is heat-shrinkably mounted on the container in a state where the layered region covers at least the projecting top of the flange portion.

The overlap film of the present invention is unlikely to crack in the design print layer due to heat shrinkage attachment.
A package in which such an overlap film is attached to an adherend is preferable from the viewpoint of appearance because a design omission part hardly occurs in the design print layer of the overlap film.

The top view which looked at the overlap film which concerns on one embodiment from the back surface side. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. However, the intermediate portion is omitted (the same applies to all cross-sectional views hereinafter). The longitudinal cross-sectional view cut | disconnected by the III-III line of FIG. 1 is a cross-sectional view showing another embodiment of a laminated structure of an anchor coat layer, a design print layer, and a second print layer (the overlap film according to another embodiment is taken at the same place as the line II-II in FIG. (The same applies to FIGS. 5 to 7). The cross-sectional view which shows other embodiment of the laminated structure of an anchor coat layer, a design printing layer, and a 2nd printing layer. The cross-sectional view which shows other embodiment of the laminated structure of an anchor coat layer, a design printing layer, and a 2nd printing layer. The cross-sectional view which shows other embodiment of the laminated structure of an anchor coat layer, a design printing layer, and a 2nd printing layer. The front view of the container which mounts an overlap film. The schematic perspective view which shows the procedure which attaches an overlap film to a container. The perspective view of the package which concerns on one embodiment. The bottom view of the package which concerns on the same embodiment. The perspective view of the package which concerns on other embodiment. The perspective view of the package which concerns on further another embodiment. The top view which looked at the overlap film produced in Example 1 from the back surface side. The front view of the container used in the Example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
However, in this specification, the “back surface” refers to a surface on the adherend side when the overlap film is attached to the adherend, and the “front surface” refers to a surface opposite to the back surface.
It should be noted that the shape, size, thickness of each layer, the relative ratio thereof, and the like shown in each drawing are different from actual dimensions.

<Layer structure of overlap film>
FIG. 1 shows a long overlap film 11. In the mechanical production process, the overlap film 11 is usually supplied in the form of a long body, and is cut along the TD direction at a required length when the film is heat shrink-fitted to the adherend (usually, the heat film is heated). One overlap film 1 having a size capable of encapsulating the adherend is formed. In addition, the dashed-dotted line of FIG. 1 shows a cutting plan line, and what was cut | disconnected by this cutting plan line becomes one overlap film 1. FIG.
As shown in FIGS. 1 to 3, the overlap film 1 of the present invention includes a heat-shrinkable polyolefin film 2, a region 6 in which an anchor coat layer 3, a design print layer 4, and a second print layer 5 are laminated. Have. Hereinafter, a region where the anchor coat layer 3, the design print layer 4, and the second print layer 5 are stacked may be referred to as a stacked region 6.
Specifically, the overlap film 1 includes a heat-shrinkable polyolefin film 2, an anchor coat layer 3 laminated on the back surface of the heat-shrinkable polyolefin film 2, and a design laminated on the back surface of the anchor coat layer 3. It has the printing layer 4 and the 2nd printing layer 5 laminated | stacked on the back surface of the said design printing layer 4. FIG. The anchor coat layer 3 includes a chlorinated polyolefin resin as a binder resin. The design print layer 4 includes a urethane resin as a binder resin. The second printing layer 5 includes a urethane resin as a binder resin, and further includes an inorganic pigment. Preferably, the anchor coat layer 3 is provided in direct contact with the back surface of the heat-shrinkable polyolefin film 2, the design print layer 4 is provided in direct contact with the back surface of the anchor coat layer 3, and the second print layer 5 is And provided in direct contact with the back surface of the design printing layer 4.
The overlap film 1 of the present invention has other layers on the condition that it has a heat-shrinkable polyolefin film 2 and a laminated region 6 of the anchor coat layer 3, the design print layer 4 and the second print layer 5. You may have.

A region 21 where the back surface of the heat-shrinkable polyolefin film 2 is exposed is provided around the anchor coat layer 3. The region where the back surface of the heat-shrinkable polyolefin film 2 is exposed is the film surface itself that has not been subjected to surface treatment such as corona discharge treatment (hereinafter may be referred to as back surface exposed region 21). In other words, the anchor coat layer 3 is provided on the inner side of the outer peripheral edge of the heat-shrinkable polyolefin film 2, and the outer periphery including the outer peripheral edge of the heat-shrinkable polyolefin film 2 has an annular shape in plan view. A backside exposed area 21 is provided. By providing the back surface exposed region 21, a good heat seal portion can be configured as will be described later.
In addition, about the elongate overlap film 11, the anchor coat layer 3 is regularly provided in the MD direction (longitudinal direction) of the elongate heat-shrinkable polyolefin film at a predetermined interval.

A design printing layer 4 is provided on the back surface of the anchor coat layer 3. The design print layer 4 is provided so as to overlap the anchor coat layer 3. The design print layer 4 is disposed inside the outer peripheral edge of the anchor coat layer 3. In other words, the design print layer 4 is provided such that the edge of the design print layer 4 overlaps or does not exceed the outer peripheral edge of the anchor coat layer 3.
A second print layer 5 is provided on the back surface of the design print layer 4. The second print layer 5 is provided so as to overlap the design print layer 4. The second print layer 5 is disposed inside the edge of the design print layer 4. In other words, the second printed layer 5 is provided so that the edge of the second printed layer 5 overlaps or does not exceed the edge of the design printed layer 4.

  FIG. 4 is a cross-sectional view of an overlap film according to another embodiment, and FIGS. 5 to 7 are cross-sectional views of an overlap film according to still another embodiment. Also in these other embodiments, the back surface exposed region 21 is provided on the outer peripheral portion of the heat-shrinkable polyolefin film 2.

In the laminated structure shown in FIGS. 2 to 3, the design print layer 4 is provided in a solid shape. For example, as shown in FIG. 4, the design print layer 4 is provided in two or more independent ranges. May be. The solid shape means that it is continuously provided in one range. Specifically, providing in a solid form includes providing it in one continuous range as a whole, such as a square shape or a donut shape in plan view.
Further, although not particularly illustrated, the second printing layer 5 may also be provided in two or more independent ranges. When the design print layer 4 is provided in two or more ranges, the second print layer 5 is provided in a solid shape including the back surface of the design print layer 4 as shown in FIG. Also good. In this case, the second print layer 5 is directly laminated across the back surface of the design print layer 4 and the back surface of the anchor coat layer 3.
Alternatively, although not particularly illustrated, the second print layer 5 may be provided only on the back surface of the design print layer 4. Alternatively, although not particularly illustrated, the second print layer 5 may be provided across a part of the back surface of the design print layer 4 and a part of the back surface of the anchor coat layer 3 (in this case, The back surface of the design print layer 4 has a portion where the second print layer 5 is not laminated).

2 to 3, the edge of the design printing layer 4 is arranged inside the outer peripheral edge of the anchor coat layer 3 and the edge of the second printing layer 5 is arranged inside the edge of the design printing layer 4. However, it is not limited to this.
For example, in FIG. 5, the design print layer 4 is arranged such that a part or all of the edge thereof coincides with the outer peripheral edge of the anchor coat layer 3, and the second print layer 5 includes the edge and design of the anchor coat layer 3. It is arranged inside the edge of the printing layer 4.
In FIG. 6, the edge of the design print layer 4 is disposed on the inner side of the outer peripheral edge of the anchor coat layer 3, and the second print layer 5 extends beyond the edge of the design print layer 4. A part or all of the edge is arranged on the outer peripheral edge of the anchor coat layer 3.
In FIG. 7, the design print layer 4 is arranged such that a part or all of the edges thereof coincide with the outer peripheral edge of the anchor coat layer 3, and the second print layer 5 has a part or all of the edges thereof anchor-coated. Arranged on the outer peripheral edge of the layer 3.
In the embodiment shown in FIGS. 5 to 7, the design print layer 4 and / or the second print layer 5 are divided into two or more independent ranges as in the embodiment shown in FIG. It may be provided.

Since it is complicated to print the design print layer 4 with high accuracy so as to coincide with the edge of the anchor coat layer 3, the edge of the design print layer 4 is positioned inside the outer peripheral edge of the anchor coat layer 3. Is preferably provided. For the same reason, it is preferable that the second printed layer 5 is also provided so that the edge thereof is located inside the outer peripheral edge of the anchor coat layer 3.
Further, when the second printed layer 5 is provided beyond the edge of the design printed layer 4, when the second printed layer 5 is viewed from the surface side of the overlap film 1, It is visually recognized as a linear pattern attached to the design print layer 4. Moreover, when the edge of the 2nd printing layer 5 is provided in agreement with the edge of the design printing layer 4, when it sees diagonally from the surface side of the overlap film 1, the 2nd printing layer 5 An edge may be visually recognized as a thin linear pattern attached to the design print layer 4. In order to prevent such an appearance from occurring, the second print layer 5 is preferably provided inside the edge of the design print layer 4.

In the embodiment shown in FIGS. 2 to 7, the design print layer 4 and the second print layer 5 do not exceed the outer peripheral edge of the anchor coat layer 3, but the design print layer 4 and / or the second print layer 5 The anchor coat layer 3 may be laminated in a state slightly exceeding the outer peripheral edge.
In the embodiment shown in FIGS. 2 to 7, the back surface of the second printing layer 5 constitutes the outermost surface of the overlap film 1 (however, the back surface of the second printing layer 5 is the overlap film 1). Not all of the outermost back surface, but the outermost back surface is mainly composed of the back surface of the second printed layer 5). In this case, when the overlap film 1 is attached to the adherend, it is preferable because the back surface of the second print layer 5 comes into contact with the adherend (the second print layer 5 and the adherend contact layer). A protective layer may be laminated on the back surface of the second print layer 5.

<Heat-shrinkable polyolefin film>
The heat-shrinkable polyolefin film 2 is a colorless and transparent heat-shrinkable film in which the main component resin constituting the film is a polyolefin resin. At least the back surface, preferably the front surface and the back surface of the heat-shrinkable polyolefin film 2 is not subjected to surface treatment such as corona discharge treatment.
In the present specification, the main component resin refers to the largest component (mass ratio) among the resin components contained therein.
The heat shrinkability refers to a property of shrinking when heated to a required temperature (for example, 70 ° C. to 160 ° C.). The heat-shrinkable polyolefin film 2 heat-shrinks in at least one direction (first direction) in the plane, and preferably heat-shrinks in two directions (first direction and second direction) perpendicular to each other in the plane. .
The heat shrinkage rate of the heat-shrinkable polyolefin film 2 is not particularly limited. For example, the heat shrinkage rate of the heat-shrinkable polyolefin film 2 in the first direction and the second direction when heated to 90 ° C. is independently 20% or more, and preferably 25% or more.
Formula: heat shrinkage rate (%) = [{(original length in the first direction (or second direction)) − (length after immersion in the first direction (or second direction))} / (first Original length of direction (or second direction)]] × 100.
The thickness of the heat-shrinkable polyolefin film 2 is not particularly limited, and is, for example, 10 μm to 60 μm, and preferably 12 μm to 40 μm.
The heat-shrinkable polyolefin film 2 is not particularly limited, and examples thereof include a polypropylene film made of polypropylene; a polyethylene film made of polyethylene, and the like, and a polypropylene film is preferable. Examples of the polypropylene include a propylene homopolymer and a propylene-ethylene copolymer, and examples of the polyethylene include a polyethylene homopolymer and a polyethylene copolymer.
The heat-shrinkable polyolefin film 2 has a plurality of well-known air vent holes. Air vent holes are not shown.

<Anchor coat layer>
The anchor coat layer 3 is a layer for improving the printability of the surface not subjected to the surface treatment. Although it is difficult to directly form ink on the back surface of the heat-shrinkable polyolefin film 2 to form a good design print layer 4, the heat-shrinkable polyolefin film is provided by providing the anchor coat layer 3. 2 can be formed on the back side.
The anchor coat layer 3 is colorless and transparent or colored and transparent in order to make the design print layer 4 on the back surface visible.
The anchor coat layer 3 contains a chlorinated polyolefin resin as a resin component.
Examples of the chlorinated polyolefin resin include chlorinated polyethylene, chlorinated polypropylene, chlorinated polyethylene, or acryl-modified or urethane-modified chlorinated polyolefin resin obtained by modifying chlorinated polypropylene with an acrylic polymer or urethane polymer having an ethylenically unsaturated bond. Etc.
The chlorine content of the chlorinated polyolefin resin is not particularly limited, but is preferably 5% by mass to 45% by mass from the viewpoint of good printability.
Although the thickness of the anchor coat layer 3 is not specifically limited, For example, it is 0.01 micrometer-3 micrometers, Preferably it is 0.05 micrometer-2 micrometers. The anchor coat layer 3 containing a chlorinated polyolefin resin is usually formed by applying a coating solution obtained by dissolving a chlorinated polyolefin resin in an organic solvent such as toluene to a required range and drying it. The solvent may not completely evaporate and may remain. In this respect, the anchor coat layer 3 having a very thin thickness as described above is remarkably low in the influence of the residual solvent, and even if the anchor coat layer 3 has a small thickness, the printability of the design printing layer 4 for ink can be improved. It can be improved.

<Design printing layer>
The design print layer 4 is a print layer on which various design displays such as a product name, a pattern, a component display, a barcode, a two-dimensional code, and a notice are displayed. The design print layer 4 can be formed by printing an ink containing a urethane resin and a colorant as a binder resin by a known printing method. The design printing layer 4 may be entirely or partially light transmissive, or may be entirely opaque.

The design print layer 4 includes a urethane-based resin and a colorant as a binder resin.
A conventionally known pigment or dye can be used as the colorant.
The urethane resin is not particularly limited, and a polyurethane resin for ink can be used. Examples of the urethane resin include a resin obtained by reacting a polyisocyanate compound and a polyol compound.
Examples of the polyisocyanate compound include one or a mixture of two or more known diisocyanates of aromatic, aliphatic and alicyclic groups. Examples of the diisocyanates include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, and isophorone diisocyanate. Further, tri- or higher functional polyisocyanates and polyisocyanate adducts may be used by mixing with diisocyanates as required.

Examples of the polyol compound include ethylene glycol, diethylene glycol, 1,3-propanediol, propylene glycol (1,2-propanediol), butanediol (1,3-butanediol, 1,4-butanediol, etc.), 1, Low molecular weight glycols such as 6-hexanediol, cyclohexanedimethanol, neopentyl glycol; polyether diols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene glycol-polycaprolactone copolymer; propylene glycol, butane Polyester obtained from diols such as diol and hexanediol and dibasic acids such as adipic acid, sebacic acid, azelaic acid, isophthalic acid, terephthalic acid and fumaric acid Rujioru; polycaprolactone diol, poly-valerolactone diol, lactone diols such as lactone block copolymer diol; diols, and the like. Moreover, diols and trifunctional or more than trifunctional polyol compounds (polyether polyol, polyester polyol, etc.) can also be mixed and used as needed.
Among these, polyester diol-based polyurethane (polyurethane obtained using polyester diol as a polyol compound) is preferable.

The glass transition temperature (Tg) of the urethane-based resin is preferably −60 to 40 ° C., more preferably −50 to 30 ° C., from the viewpoint of flexibility. The Tg can be measured, for example, by DSC (differential scanning calorimetry). The DSC measurement is not particularly limited. For example, the DSC measurement can be performed using a differential scanning calorimeter “DSC6200” manufactured by Seiko Instruments Inc. under a temperature rising rate of 10 ° C./min.
Commercially available products can also be used as the urethane resin. For example, “Samprene IB series, LQ series” manufactured by Sanyo Chemical Industries, Ltd. is available on the market.

Although the thickness of the design print layer 4 is not specifically limited, For example, they are 0.1 micrometer-5 micrometers.
The binder resin of the design print layer 4 may contain other binder resins and optional additives on condition that the binder resin contains a urethane resin. However, the urethane-based resin is a main component resin of the binder resin in the design print layer 4.
Although content of the urethane type resin in the design print layer 4 is not specifically limited, 50 mass%-95 mass% are preferable with respect to the total amount (100 mass%) of the design print layer 4, 60 mass%-90 The mass% is more preferable. If the content of the urethane resin is too small, the flexibility of the design print layer 4 is lowered, and the adhesion between the design print layer 4 and the anchor coat layer 3 may be lowered.

<Second printing layer>
The second printing layer 5 is a printing layer containing a urethane resin and an inorganic pigment. The second printing layer 5 is, for example, a colorless and transparent, colored and transparent, non-pattern one color or non-pattern multi-color print layer. The second printing layer 5 can be formed by printing an ink containing a urethane resin and an inorganic pigment as a binder resin by a known printing method. The second printed layer 5 may be entirely or partially light transmissive, or entirely opaque.
Examples of the urethane resin of the second print layer 5 include urethane resins as exemplified in the design print layer 4.
Examples of the inorganic pigment include colored pigments such as titanium oxide, zinc oxide, aluminum oxide, bengara, antimony red, cadmium yellow, cobalt blue, bitumen, ultramarine blue, carbon black, and graphite; silica, calcium carbonate, kaolin, clay, And extender pigments such as barium sulfate, aluminum hydroxide, and talc; pearl pigments such as mica and metal oxide-coated mica; and the like. An inorganic pigment can be used individually by 1 type or in combination of 2 or more types. Among these, the inorganic pigment preferably contains at least one selected from metal oxides such as titanium oxide, zinc oxide, and aluminum oxide, silica, calcium carbonate, and mica, and more preferably contains titanium oxide.
In addition, the 2nd printing layer 5 containing white pigments, such as a titanium oxide and an aluminum oxide, exhibits white, and the 2nd printing layer 5 containing pearl pigments, such as a mica, exhibits a iridescent color.

Although the thickness of the 2nd printing layer 5 is not specifically limited, For example, they are 0.5 micrometer-5 micrometers.
The binder resin of the second printing layer 5 may contain other binder resins and optional additives on condition that the binder resin contains a urethane resin. However, the urethane-based resin is a main component resin of the binder resin in the second printing layer 5.
Although content of the urethane type resin in the 2nd printing layer 5 is not specifically limited, 20 mass%-55 mass% are preferable with respect to the total amount (100 mass%) of the 2nd printing layer 5, 25 mass%. -50 mass% is more preferable. If the content of the urethane resin is too small, the flexibility of the second printing layer 5 is lowered, and the second printing layer 5 may reduce the flexibility of the design printing layer 4.
Although content of the inorganic pigment in the 2nd printing layer 5 is not specifically limited, 40 mass%-85 mass% are preferable with respect to the total amount (100 mass%) of the 2nd printing layer 5, 45 mass%- 80 mass% is more preferable and 50 mass%-75 mass% is still more preferable. Furthermore, when the inorganic pigment is titanium oxide, the content of titanium oxide in the second printed layer 5 is 60% by mass to 85% by mass with respect to the total amount (100% by mass) of the second printed layer 5. Preferably, 65 mass%-80 mass% is more preferable. If the content of the inorganic pigment is too small, the design print layer 4 may not be sufficiently cracked. On the other hand, if the content of the inorganic pigment is too large, the amount of the binder resin is relatively small, 2 The strength of the printing layer 5 is lowered.

<Usage example of overlap film>
The overlap film 1 of the present invention is used by being heat-shrinkably attached to various adherends.
The overlap film 1 is used as a protective film for covering a single adherend, or around a collection of a plurality of adherends for the purpose of a protective and binding film. It is used with the cover attached.
The adherend is not particularly limited, and may be a container in which an article is stored or the article itself.
Examples of adherends include instant foods such as instant noodles, dairy products such as yogurt, taste foods such as jelly and pudding, sanitary products such as beverages, seasonings and shampoo, and fresh foods such as meat. Containers; articles such as dry batteries.
When the adherend is an article-containing container, the outer shape of the container is not particularly limited, and is a cylindrical shape such as a cylindrical shape, an elliptical cylindrical shape, or a rectangular cylindrical shape; an inverted truncated cone shape, an inverted elliptical truncated cone shape, an inverted shape Examples thereof include an inverted frustum shape such as a quadrangular frustum shape, and an irregular shape such as a bowl shape.
The material of the container is not particularly limited, and examples thereof include synthetic resin, foamed synthetic resin, metal, glass, earthenware, and wood material.

For example, a container 7 (adhered body) shown in FIG. 8 includes a container main body 71 in which an article is stored, a flange portion 72 protruding radially outward from the container main body 71, and an upper surface opening of the container main body 71. And a lid member 73 to be closed. The container 7 is an inverted frustum-shaped cup container 7 as a whole. The container body 71 in the illustrated example has an inverted quadrangular truncated pyramid shape whose outer shape in the horizontal section is a quadrangle. The flange portion 72 protrudes in the horizontal direction at the upper end portion of the container body 71. The protruding top portion 72 a of the flange portion 72 forms the outermost portion on the side of the container 7. Further, the lid member 73 is not particularly limited, and for example, a sheet lid or the like that is detachably bonded to the flange portion 72 is used.
Such a container 7 is widely used as a container for storing instant food such as instant noodles.

Next, a procedure for manufacturing a package by attaching the overlap film 1 to the container 7 will be described.
FIG. 9 is a schematic perspective view showing the procedure for manufacturing the package. In FIG. 9, the shaded portion indicates the laminated region 6, the white portion indicates the back surface exposed region 21, and the hatched portion indicates the heat seal portions 27, 28, and 29 (hereinafter, The same applies to FIGS. 10 to 13.
As shown in FIG. 9, while making the long overlap film 11 into a cylindrical shape, the back surfaces of both end portions along the MD direction (longitudinal direction) are overlapped (glued together), and both surfaces are heat-sealed. Thus, the heat seal portion 27 extending in the MD direction is formed. Since the both end portions are the back surface exposed regions 21 that do not have the anchor coat layer 3 or the like, the heat sealing can be performed satisfactorily. The container 7 (adhered body) is inserted into the cylinder of the long overlap film 11 formed in this cylindrical shape. Note that the overlap film 11 may be formed in a cylindrical shape by heat-sealing the back surfaces of both end portions while wrapping the container 7 with the overlap film 11.
The elongate overlap film 11 in which the container 7 is put in the cylinder is melt-insulated and sealed in the TD direction at both front and rear end portions of the container 7 to form heat seal portions 28 and 29. Since both the front and rear end portions are the back surface exposed regions 21 that do not have the anchor coat layer 3 or the like, the heat sealing can be performed satisfactorily. In this way, the container 7 is encapsulated and the three sides are heat-sealed portions (two heat-insulating seal portions 28 and 29 extending in the TD direction and one heat-sealing portion 27 extending in the MD direction). An overlap film 1 is obtained.
Thereafter, the bag-like overlap film 1 enclosing the container 7 is guided to a shrink tunnel or the like and heated to a required temperature, so that the air existing in the bag-like shape escapes to the outside from the air vent hole. The film 1 is heat-shrinked and adheres to the container 7 to obtain the package 10.

FIG. 10 is a perspective view of the package 10 and FIG. 11 is a bottom view thereof.
In the package 10, the overlap film 1 is mounted on the container 7 in a state where the laminated region 6 of the overlap film 1 covers the protruding top portion 72 a of the flange portion 72 of the container 7. The heat seal portions 27, 28, and 29 of the overlap film 1 are formed in the back surface exposed region 21. In the package 10, the heat seal portions 27, 28, and 29 do not overlap the flange portion 72 of the container 7, and most of the heat seal portion 27 is placed on the bottom surface of the container body 71. The heat seal portions 28 and 29 are disposed on the side surface of the container body 71.
In general, the overlap film adheres to the adherend due to heat shrinkage, but there are few cases in which the entire overlap film adheres to the adherend, and the overlap film is the outermost point that connects the outermost points of the adherend. Strongly adheres along the outer shape. In this way, when the overlap film is thermally shrunk, the location corresponding to the outermost part of the adherend adheres strongly to the adherend, so in conventional overlap films, design printing corresponding to that location is possible. Layers are prone to cracking.
In this regard, the overlap film 1 of the present invention may cause cracks in the design print layer 4 at a location corresponding to the protruding top portion 72a even if the laminated region 6 covers the protruding top portion 72a of the flange portion 72 of the container 7. Can be prevented. Of course, there is no possibility that cracks may occur in the design print layer 4 in the laminated region 6 other than the portion corresponding to the protruding top portion 72a.
The reason why it is difficult for the overlapped film 1 of the present invention to cause cracks in the design print layer 4 before and after thermal shrinkage is not clear, but the present inventors presume as follows.
That is, the design print layer 4 of the overlap film 1 of the present invention contains a urethane resin as a binder resin, so is relatively flexible and easily follows the heat shrinkage of the heat shrinkable polyolefin film 2. Furthermore, since the second printing layer 5 provided on the back surface of the design printing layer 4 also contains a urethane resin as a binder resin, it easily follows heat shrinkage, and further contains an inorganic pigment. The second printing layer itself has a function of reinforcing the design printing layer 4 because the second printing layer itself hardly breaks. For this reason, when the overlap film 1 is heated and contracted, it is possible to prevent the design print layer 4 from being cracked and causing a design omission in the layer.
In particular, in the case where the back surface of the second print layer 5 forms the outermost back surface of the overlap film 1, the second print layer 5 is formed in a region where the second print layer 5 is laminated on the design print layer 4. Since the design print layer 4 is in direct contact with the adherend and not in direct contact with the adherend, the occurrence of cracks in the design print layer 4 can be effectively prevented.

FIG. 12 shows a package 10 in which the overlap film 1 is heat-shrink mounted on a container 7 having a container body having a circular (or elliptical) outer shape in the horizontal section. The package 10 can be manufactured in the same manner as the package 10 of FIG. 10 except that the shape of the container body 71 is different.
The package 10 of FIG. 12 also has a flange 72 projecting radially outward from the upper end of the inverted truncated cone (or inverted elliptical truncated cone) container body. The overlap film 1 is mounted in a state of covering the protruding top portion 72a.

FIG. 13 shows a package 10 in which an overlap film 1 is heat-shrink mounted on an assembly of a plurality of (for example, five) containers 7. The package 10 can be manufactured in the same manner as the package 10 of FIG. 10 except that the adherend is made of an aggregate.
Each container 7 in FIG. 13 has no flange portion, but a part of the upper end of each container 7 is the outermost part of the aggregate. The overlap film 1 is mounted in a state where the laminated region 6 covers at least the outermost portion of the aggregate.
Thus, the packaging body may be comprised by mounting | wearing the container which does not have a flange part with the overlap film 1 of this invention.

  Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

[Materials used]
Heat-shrinkable polyolefin film: Polypropylene film with a thickness of 15 μm and no surface treatment (trade name “Kojijin Polyset AS” manufactured by Kojin Film & Chemicals).
Anchor coating agent: A solution comprising 5 parts by mass of chlorinated polypropylene resin (trade name “Super Clon 803 MW” manufactured by Nippon Paper Chemicals Co., Ltd., chlorine content 29.5%) and 95 parts by mass of toluene.

Design ink: 1 part by mass of urethane resin (trade name “IB-915” manufactured by Sanyo Chemical Co., Ltd. Mw = 40,000 to 50,000, Tg = about −50 ° C.) and 15 parts by mass of indigo pigment (copper phthalocyanine Blue), 50 parts by mass of a solvent, and 5 parts by mass of an additive.
Design ink 2: 9 parts by mass of acrylic resin (trade name “BR-113” manufactured by Mitsubishi Rayon; Mw = 75,000, Tg = about 75 ° C.) and 15 parts by mass of indigo pigment (copper phthalocyanine blue) And 70 parts by mass of a solvent and 5 parts by mass of an additive.

Second ink A: 31.5 parts by mass of urethane resin (trade name “IB-915” manufactured by Sanyo Chemical Co., Ltd. Mw = 40,000 to 50,000, Tg = about −50 ° C.) and 25 parts by mass of inorganic white An ink comprising a pigment (titanium oxide), 19 parts by mass of a solvent, and 4.5 parts by mass of an additive.
Second ink B: 31.5 parts by mass of urethane resin (trade name “IB-915” manufactured by Sanyo Chemical Co., Ltd., Mw = 40,000 to 50,000, Tg = about −50 ° C.) and 35 parts by mass of inorganic white An ink comprising a pigment (titanium oxide), 19 parts by mass of a solvent, and 4.5 parts by mass of an additive.
Second ink C: 31.5 parts by mass of urethane resin (trade name “IB-915” manufactured by Sanyo Chemical Co., Ltd., Mw = 40,000 to 50,000, Tg = about −50 ° C.) and 45 parts by mass of inorganic white An ink comprising a pigment (titanium oxide), 19 parts by mass of a solvent, and 4.5 parts by mass of an additive.
Second ink D: 10.5 parts by mass of acrylic resin (trade name “BR-113” manufactured by Mitsubishi Rayon, Mw = 75,000, Tg = about 75 ° C.) and 45 parts by mass of an inorganic white pigment ( Titanium oxide), 40 parts by mass of solvent, and 4.5 parts by mass of additive.
Second ink E: 65.5 parts by mass of urethane resin (trade name “IB-915” manufactured by Sanyo Chemical Co., Ltd. Mw = 40,000 to 50,000, Tg = about −50 ° C.), 30 parts by mass of solvent, , 4.5 parts by weight of an additive.

[Example 1]
An anchor coat layer having a thickness of about 1 μm is formed by applying an anchor coating agent in a solid shape using a gravure printing machine within a range of 480 mm × 265 mm in the plane of the heat-shrinkable polyolefin film and drying. Formed.
On the back surface of the anchor coat layer, the design ink 1 was applied in a solid shape using a gravure printing machine and dried to form a design print layer having a thickness of about 1 μm.
A second printing layer having a thickness of about 2.5 μm was formed on the back surface of the design printing layer by applying the second ink A in a solid form using a gravure printer and drying it.
Then, by cutting the heat-shrinkable polyolefin film along a line 10 mm away from the outer periphery of the anchor coat layer, as shown in FIG. An overlap film in which an anchor coat layer, a design print layer, and a second print layer (lamination region) were laminated was produced. In FIG. 14, the portion to which the innumerable dots are added is a laminated region, and the white portion is a back surface exposed region where the back surface of the film is exposed, and details of the width and length of the film and the width of the back surface exposed region are shown. The dimensions are also shown.

[Example 2]
An overlap film was produced in the same manner as in Example 1 except that the second ink B was used in place of the second ink A.

[Example 3]
An overlap film was produced in the same manner as in Example 1 except that the second ink C was used instead of the second ink A.

[Comparative Example 1]
An overlap film was produced in the same manner as in Example 1 except that the design ink 2 was used instead of the design ink 1.

[Comparative Example 2]
An overlap film was produced in the same manner as in Example 1 except that the second ink D was used instead of the second ink A.

[Comparative Example 3]
An overlap film was produced in the same manner as in Example 1 except that the design ink 2 was used instead of the design ink 1 and that the second ink D was used instead of the second ink A. .

[Comparative Example 4]
An overlap film was produced in the same manner as in Example 1 except that the second ink E was used instead of the second ink A.

<Design ink fixing evaluation (no heating)>
The part which has the lamination | stacking area | region of the overlap film of Example 1 was cut out to 100 square mm, and the sample piece was obtained. After grasping the both ends of this sample piece with both hands and tenking with 10 hands, the state of the design print layer was visually confirmed. The results were distinguished by the following evaluation criteria. In the same manner for other examples and comparative examples, the fixing condition of the printed layer in a state without heating was confirmed. The results are shown in Table 1 and Table 2 for ink fixing (no heating).
○: There was no peeling of the design print layer.
Δ: Some peeling occurred along the wrinkles generated in the design print layer.
X: Peeling occurred even around the periphery of the wrinkles formed in the design print layer.

<Design ink fixing evaluation (with heating)>
The part which has the lamination | stacking area | region of the overlap film of Example 1 was cut out to 200 square mm, and the sample piece was obtained. Four sides of this sample piece were attached to a jig, and the sample piece was thermally shrunk to 50% in length and width by using a jetter (heating gun manufactured by Hakuko Co., Ltd.). After gripping the both ends of the sample piece after heat shrinkage with both hands and tenking with hands, the state of the design print layer was visually confirmed. The results were distinguished by the above evaluation criteria. In the same manner for other examples and comparative examples, the fixing condition of the printed layer in the state after heating was confirmed. The results are shown in Table 1 and Table 2 for ink fixing (with heating).

<Evaluation of design print layer of package>
A container with a flange portion having dimensions as shown in FIG. 15 was prepared. This container has a container body with a flange portion made of foamed resin, and a sheet lid thermally welded to the upper surface of the flange portion. The opening of the container body is an opening having a substantially square shape when viewed from above, and the protruding top portion of the flange portion has a substantially square shape when viewed from above, and the protruding top portion of the flange portion is at the side of the container. It is the outermost part.

Air vent holes (hole diameter: about 0.3 mm) were formed in the surface of the overlap film produced by the procedure of Example 1 at intervals of about 30 mm in length and width. The overlap film was formed into a cylindrical shape by overlapping and heat-sealing the back surfaces (back surface exposed regions) of both end portions of this overlap film having a length of 285 mm. The container shown in FIG. 15 is inserted into the cylinder of the cylindrical overlap film, and the back surface of the side end portion of the 500 mm long overlap film formed in the cylinder shape is thermally sealed, as shown in FIG. A bag-like overlap film was produced which encased a container and was heat-sealed on three sides.
Next, the bag-like overlap film in which a container is encapsulated is placed in a 160 ° C. constant temperature bath in which a columnar metal base having a diameter of 100 mm and a height of 100 mm is installed. Then, the thermostatic chamber door was closed and heated for 20 seconds to heat shrink the overlap film. Thus, the package as shown in FIG. 10 was obtained. In this package, the overlap region of the overlap film was in close contact with all of the protruding top portions of the flange portion of the container.

(Crack of printed layer)
After visually observing the state of the design print layer from the outside of the obtained package, and tearing the overlap film by hand and peeling it off the container, visually check the state of the design print layer from the back side of the film. Observed at. The results were distinguished by the following evaluation criteria.
○: No crack occurred in the design print layer.
Δ: There was no crack before the film was broken, but a slight crack occurred in the design print layer when viewed from the back side after the film was broken.
X: A crack occurred in the design print layer before the film was broken.

(Print layer peeling)
After the overlap film was broken by hand and peeled off from the container, the peeling of the design print layer was visually observed. The results were distinguished by the following evaluation criteria.
○: No peeling of the design print layer occurred.
X: Peeling of the design print layer occurred.

(Transition of printing layer)
After the overlap film was broken by hand and peeled off from the container, it was visually observed whether the design print layer had transferred to the container. The results were distinguished by the following evaluation criteria.
○: Ink transfer in the design print layer did not occur.
X: Ink transfer of the design print layer occurred.

  For other examples and comparative examples, a package was produced in the same manner as the overlap film of Example 1, and the design print layer of the package was similarly evaluated. The results are shown in Tables 1 and 2.

  The overlap film of Examples 1 to 3 in which the design print layer contains a urethane resin and the second print layer contains a urethane resin and titanium oxide (inorganic pigment) is excellent in the ink fixing property of the design print layer, Furthermore, it can be seen that cracks and delamination of the design print layer hardly occur even after being mounted on the package.

DESCRIPTION OF SYMBOLS 1 Overlap film 2 Heat-shrink polyolefin film 3 Anchor coat layer 4 Design printing layer 5 2nd printing layer 6 Area | region where the anchor coating layer, the design printing layer, and the 2nd printing layer were laminated | stacked 7 Container 72 Flange part 72a Flange part Projection top 10 Package

Claims (4)

Heat shrinkable polyolefin film,
An anchor coat layer laminated on the back surface of the heat-shrinkable polyolefin film and containing a chlorinated polyolefin resin;
A design print layer laminated on the back surface of the anchor coat layer and containing a urethane resin;
A second printed layer laminated on the back surface of the design printed layer and containing a urethane-based resin and an inorganic pigment;
An overlap film having.   The overlap film according to claim 1, wherein the second print layer includes titanium oxide.   The overlap film of Claim 1 or 2 which has the area | region where the back surface of the film was exposed in the outer peripheral part of the said heat-shrinkable polyolefin-type film. The overlap film according to any one of claims 1 to 3, and a container having a container body and a flange portion projecting radially outward from the container body,
The packaging body in which the overlap film is heat-shrinkably mounted on the container in a state where the region where the anchor coat layer, the design layer, and the second printing layer are stacked covers at least the projecting top of the flange portion.

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