JP3674713B2 - Stretch label - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a stretch label attached to a container such as a bottle, a can, or a PET bottle.
[0002]
[Prior art]
In general, for example, as shown in FIGS. 2 (a) to 2 (d), the stretch label 14 is made of an ethylene polymer or a copolymer having excellent elastic elasticity having a printing layer printed with a design or a trademark on the inner surface side. The end portions 11, 11 of a self-stretchable stretch film 10 made of a polymer or the like are joined together to form a cylinder.
Thereafter, the stretch label 14 was externally fitted from above the container 13 such as a PET bottle as shown in FIG. 2 (e), and was closely attached to the container by the elastic recovery force of the stretch label itself. Such a stretch label 14 is described in, for example, Japanese Patent Application Laid-Open No. 61-115944, which is attached to a container by a restoring force due to elasticity of the label itself which does not require an adhesive or heat shrink treatment. A stretch label made of linear polyethylene is disclosed.
[0003]
[Problems to be solved by the invention]
However, when such a stretch label 14 is externally attached to the container 13 or the like, wrinkles or the like are likely to occur, and the above-mentioned problem is remarkable particularly when the attachment portion has unevenness or a curved surface portion.
[0004]
In addition, when food / beverage products or medicines are filled in the container 13 with the stretch label 14 attached, a hot water shower is applied from the outer surface of the container 13 after the food / beverage products or medicines are filled in the container 13. There are cases where a low-temperature heat sterilization treatment for sterilization is performed.
[0005]
In this low-temperature heat sterilization treatment, a container 13 such as a PET bottle is normally sterilized with hot water of 70 ° C. to 90 ° C. for about 5 to 40 minutes. In this case, the stretch label 14 made of an ethylene-vinyl acetate copolymer or the like is stretched together with the container 13 by the heat of hot water and then contracted by a cooling treatment, but the container 13 and the stretch label 14 are stretched and contracted. Therefore, as shown in FIG. 3, sagging, wrinkles 15 and the like are generated on the surface of the stretch label 14, and the appearance is not preferable.
[0006]
The present invention has been made in order to solve such problems, and it is an object to provide a stretch label having an excellent appearance that is less likely to wrinkle when mounted on a container or other heat-treated. And
[0007]
[Means for Solving the Problems]
As a means for solving the above-mentioned problems, the present invention provides a cylindrical stretch label that is formed of a stretch film 1 having a self-stretching property provided with a printing layer 4 and is externally attached to a container. The stretch label main body 10 includes a base material 2 made of amorphous polyolefin, a stretch film 1 made of synthetic resin layers 3a and 3b provided on the inner and outer surfaces of the base material 2, and a print formed on the stretch film 1. When the heat treatment at 70 ° C. or higher is performed, the layer 4 contracts in the range of 1 to 15% in the mounting direction to the container .
[0008]
[Action]
That is, as described above, the stretch label is composed of a film having a three-layer structure in which a synthetic resin layer is provided on the inner and outer surface sides of a base material made of amorphous polyolefin.
As a result, it is possible to prevent the generation of wrinkles and sagging in the label when the stretch label is attached to the container or during the low-temperature heat sterilization treatment.
Furthermore, it becomes a label excellent in elastic recovery property after elongation due to the property of amorphous polyolefin.
[0009]
In addition, when the stretch label is formed so that the shrinkage rate when heated to 70 ° C or more is in the range of 1 to 15% in the mounting direction to the container, the stretch label is attached in the mounting direction during the low temperature heat sterilization treatment. It is possible to effectively prevent horizontal wrinkles by contracting.
[0010]
Furthermore, since the printing layer rougher than the film is formed on the innermost surface side of the stretch label, the container and the stretch label are attached in an appropriate tension state via the print layer.
As a result, even when the stretch label expands or contracts during attachment or during low-temperature heat sterilization treatment, the stretch label does not adhere to the container too much, so that the entire stretch label can expand and contract evenly.
[0011]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
1A and 1B, reference numeral 10 denotes a stretch label body, and the stretch label body 10 is composed of a stretch film 1 and a printed layer 4 provided on an inner surface 11 of the stretch film 1.
The stretch film 1 is a film having a three-layer structure comprising a base 2 made of amorphous polyolefin and ethylene-based synthetic resin layers 3a and 3b provided on the inner and outer surfaces of the base 2.
The synthetic resin layers 3a and 3b are formed of an outer surface layer 3a that becomes the outer surface side and an inner surface layer 3a that becomes the inner surface side when the stretch film 1 is formed in a cylindrical shape.
[0013]
The amorphous polyolefin used for the substrate 2 has an extraction insoluble content of 70% by weight or less, preferably 60% by weight or less when subjected to Soxhlet extraction with boiling n-heptane. It is desirable that the propylene component content is 50% by weight or more with good mechanical properties and heat resistance.
The average molecular weight of the amorphous polyolefin used for the substrate 2 in this example is 1,000 to 200,000, preferably 1, in consideration of film productivity, toughness, elastic recovery, heat resistance, and the like. It is desirable to be in the range of 500 to 100,000.
[0014]
Specifically, as the amorphous polyolefin used for the substrate 2 of the present example, 60 parts by weight of a propylene / butene-1 copolymer (butene-1 content 35% by weight amorphous), and crystalline polypropylene A product obtained by uniformly kneading 40 parts by weight (melt flow rate 1.5 g / 10 min (230 ° C.)) (for example, trade name: Ube Polypro CAP350 manufactured by Ube Industries, Ltd.) was used.
[0015]
The synthetic resin layers 3a and 3b were made of an ethylene-vinyl acetate copolymer (vinyl acetate content 2% by weight, melt flow rate 3 g / 10 min (190 ° C.)).
[0016]
The printed layer 4 is formed by applying a known surface treatment such as corona treatment on the inner surface 11 of the stretch film 1 so that printing is easy, and printing a character pattern or the like by a known printing method such as gravure printing. .
[0017]
Further, it is desirable that the printed layer 4 has an average surface roughness (R _a ) (according to JIS B 0601) of 0.5 to 5.0 μm, preferably 0.8 to 4.0 μm.
In this example, the printing layer 4 was formed so as to have a thickness of 1.3 μm.
If the average surface roughness is less than this range, the label will be too close to the surface of the container when the container is mounted, and wrinkles etc. are likely to occur. It tends to occur.
[0018]
The average surface roughness of the printing layer 4 can be adjusted by changing the amount and size of appropriate inorganic fine particles such as silica and pigments such as titanium oxide in the printing ink.
[0019]
Next, a method of manufacturing the stretch label body 10 having the above-described configuration on the stretch label 7 will be described.
[0020]
First, a method for producing the stretch film 1 having the three-layer structure is as described below.
First, the amorphous polyolefin and the ethylene-vinyl acetate copolymer are supplied to separate extruders so that the amorphous polyolefin is the center and the ethylene-vinyl acetate copolymer is a layer on both sides. A co-extruded film having a three-layer structure as described above is formed as a die.
[0021]
When this co-extruded film is pulled from the T-shaped die, a film having a property of slightly shrinking in the uniaxial direction can be formed by giving a draft of about 10 and imparting a slight molecular orientation in the longitudinal direction of the film. .
[0022]
The thickness a of the substrate 2 is 50 μm, and the thicknesses b and c of the inner and outer surface layers 3a and 3b formed on both sides of the substrate 2 are each 25 μm.
[0023]
The stretch film 1 formed in this way is made of a film having a property of shrinking slightly in a uniaxial direction when subjected to low temperature heat sterilization treatment, and the shrinkage rate is in the range of 1 to 15% at 90 ° C. Particularly, it is preferably 3 to 12%, and wrinkles, sagging, label distortion, etc. are likely to occur outside this range.
In this example, when formed into a stretch label, the stretch film 1 was given a property of shrinking so that the shrinkage rate of the label was 5.5%.
The shrinkage ratio is measured by measuring the dimensional change after the stretch film 1 is immersed for 10 seconds in hot water of 90 ° C. and taken out.
[0024]
Further, the above-described printing layer 4 is provided on the inner surface 11 of the stretch film 1 having such a three-layer structure, and as shown in FIG. 2 (a), the printing layer 4 is on the innermost surface side and the synthetic resin layer 3a. , 3b is formed in a cylindrical shape so that the outer surface layer 3a side is the outermost surface side, and both ends 1a, 1b are bonded by an adhesive 6 to form a stretch label body 10.
[0025]
At this time, the stretch film 1 is formed on the stretch label body 10 in such a direction as to contract in the container mounting direction A.
[0026]
The stretch label main body 10 formed in this way is opened while expanding the diameter, as shown in FIGS. 2 (d) and 2 (e), and is fitted externally from above the PET bottle 5 as a stretch label 7. used.
[0027]
While the conventional stretch label often wrinkles at the time of wearing, the stretch label 7 using the stretch film 1 having the three-layer structure as described above hardly causes wrinkles.
[0028]
Moreover, when filling the PET bottle 5 with the stretch label 7 filled with a carbonated beverage containing fruit juice, for example, in order to sterilize the carbonated beverage containing fruit juice in the PET bottle 5, it is subjected to low-temperature heat sterilization treatment.
This low temperature heat sterilization method is a method in which a hot water shower at a temperature of about 70 to 90 ° C. is applied from the outer surface of the PET bottle 5 for about 5 to 40 minutes, and the carbonated beverage containing fruit juice inside is heat sterilized.
[0029]
When the stretch label 7 of the present invention is externally attached to the PET bottle 5 and subjected to low-temperature heat sterilization treatment, a film that contracts in the mounting direction A of the PET bottle 5 when heated is used for the stretch film 1. Like a stretch label, wrinkles and the like are not generated after low-temperature heat sterilization treatment, and a good appearance can be maintained.
[0030]
In the above embodiment, the base material 2 of the stretch film 1 was prepared by uniformly kneading a propylene-butene-1 copolymer and crystalline polypropylene, but other amorphous polyolefins such as propylene-ethylene copolymer are used. Polymers, propylene-ethylene-butene 1-3 terpolymers and the like may be used alone, or a mixture of these amorphous polyolefin and crystalline polyolefin may be used as the material of the substrate 2. Also good.
However, in this case, it is desirable that the ratio of amorphous polyolefin accounts for 50% by weight or more of the whole.
[0031]
In the above embodiment, ethylene-vinyl acetate copolymer is used as the material for the synthetic resin layers 3a, 3b of the stretch film 1. However, as the material for the synthetic resin layers 3a, 3b, crystallinity can also be used. An ethylene-based or propylene-based polymer or a copolymer thereof can be used, and is not limited to the above examples.
Specific examples include low density polyethylene, linear low density polyethylene, crystalline propylene / ethylene / random copolymer, crystalline propylene / butene-1 / ethylene terpolymer, ethylene / (meth) acrylic acid copolymer. Examples thereof include polymers and ionomers.
[0032]
Further, in the above embodiment, the outer surface layer 3a and the inner surface layer 3b are made of the same synthetic resin layers 3a and 3b made of ethylene-vinyl acetate copolymer, but the outer surface layer 3a and the inner surface layer 3b are the same material. The outer surface layer 3a is low density polyethylene, the inner surface layer 3b is an ethylene-vinyl acetate copolymer, the outer surface layer 3a is a propylene-ethylene copolymer, and the inner surface layer 3b is ethylene- Vinyl acetate copolymer, outer surface layer 3a is linear low density polyethylene, inner surface layer 3b is an ethylene-acrylic acid copolymer, outer surface layer 3a is propylene / ethylene / butene-1 terpolymer and inner surface layer 3b However, the combination of the materials of the synthetic resin layers 3a and 3b is not limited to the above embodiment.
[0033]
Further, in the above embodiment, the stretch film 1 is formed by a co-extrusion method as a method for forming a three-layer structure, but in addition, a so-called laminating method in which each film is formed and bonded with an adhesive or the like. A film having a three-layer structure may be formed by other known methods such as the above.
[0034]
In the above embodiment, the thickness a of the substrate 2 is 50 μm, the thicknesses b and c of the inner and outer surface layers formed on both sides of the substrate 2 are each 25 μm, and the thickness b of the outer surface layer 3a. The thickness c of the inner layer 3b is the same as that of the inner layer 3b. However, the thickness of the base material 2 and the synthetic resin layers 3a, 3b is not limited to the above values, and the entire stretch film 1 is used. It is desirable that the thickness a of the base material 2 occupying the thickness of 30 to 80%, preferably 40 to 80%.
When the thickness of the base material 2 is larger or smaller than the above range, it becomes difficult to maintain a good appearance after the label is mounted.
[0035]
Furthermore, in the said Example, although the thickness b, c of the outer surface layer 3a and the inner surface layer 3b was used, it is not conditions that this thickness b, c is the same.
However, since the label may curl depending on the type of label, it is desirable that the thickness be the same in that case.
[0036]
Moreover, in the said Example, in order to make it easy to print on the surface of the stretch film 1, surface treatments, such as a corona treatment, were given, However, This surface treatment is not conditions.
[0037]
Furthermore, the printing method of the printing layer 4 is not limited to the gravure printing as in the above embodiment, and any other known printing method such as flexographic printing that can be printed on the film as described above can be used. Can be applied to stretch labels.
Moreover, in the said Example, although the printing layer 4 was formed in the inner surface 11 surface of the stretch film 1, it is not conditions that the printing layer 4 is formed in the front surface of the stretch film 1, for example, when a container has an unevenness | corrugation A printing layer may be partially formed in accordance with the shape of the container.
[0038]
Moreover, in the said Example, although PET bottle 5 was used as a container, the container by which the stretch label 7 of this invention is mounted | worn is not restricted to this, In addition, various synthetic resin containers, metal cans, bottles, etc. Can also be used.
Further, the kind of items stored in the container is not limited, such as food, beverages, chemicals, and detergents.
[0039]
Furthermore, although the said Example demonstrated the case where the stretch label 7 was mounted | worn with PET bottle 5 and the low temperature heat sterilization process was performed, it is not conditions to perform a low temperature heat sterilization process, for example, the stretch label 7 of this invention Even when the container equipped with is stored in a high temperature state for heat retention or the like, an effect that wrinkles or the like on the surface of the stretch label 7 can be prevented can be obtained.
[0040]
Moreover, in the said Example, although the film shrink | contracted only to a mounting direction at the time of a low-temperature heat sterilization process was used, the stretch film which provided the property extended | stretched slightly in the circumferential direction simultaneously with shrinking | contracting to a mounting direction, for example can also be formed.
When a stretch label is formed using such a stretch film, even when the PET bottle 5 expands in the circumferential direction during the low-temperature heat sterilization treatment, the stretch label also expands as the PET bottle 5 expands. The effect that wrinkles or the like hardly occur on the surface is obtained.
[0041]
【The invention's effect】
As described above, the stretch label of the present invention is composed of a stretch film having a three-layer structure in which a synthetic resin layer is provided on both sides of a base material made of amorphous polyolefin. When the treatment is performed, the elastic recovery property after stretching is excellent, and the generation of wrinkles and sagging can be prevented, and the stretch label has an excellent appearance.
[0042]
In addition, since the stretch label of the present invention is provided with a printed layer so as to be in contact with the container, the stretch label is attached to the container in an appropriate tension state when attached or subjected to low temperature heat sterilization treatment. There is no excessive adhesion, and wrinkles and sagging are less likely to occur.
As a result, a stretch label having an even better appearance without wrinkles or the like can be obtained.
[0043]
Further, when a stretch film that shrinks in the container mounting direction due to heat is used, the effect of effectively preventing the occurrence of wrinkles can be obtained.
[Brief description of the drawings]
1A is a cross-sectional view of a stretch label of the present invention, and FIG. 1B is an enlarged cross-sectional view taken along line XX of FIG.
FIG. 2 is an explanatory view showing an example of a method of attaching the stretch label according to the present invention and the conventional one.
FIG. 3 is a perspective view showing a PET bottle equipped with a conventional stretch label.
[Explanation of symbols]
1 Stretch film 2 Base material
3a, 3b Synthetic resin layer 4 Printing layer 7 Stretch label

Claims (4)

In a cylindrical stretch label formed of a self-stretchable stretch film (1) provided with a printing layer (4) and externally attached to a container, the stretch label body (10) is made of amorphous polyolefin. Formed on the stretch film (1) and the stretch film (1) composed of the base resin (2) and the synthetic resin layers (3a) and (3b) provided on the inner and outer surfaces of the base material (2). A stretch label comprising: a printed layer (4), which shrinks in a range of 1 to 15% in a mounting direction to a container when subjected to a heat treatment of 70 ° C. or more . The base synthetic resin layer of the inner surface and the outer surface of (2) (3a), ( 3b) is a stretch label claim 1, wherein the ethylene polymer or Ranaru. The stretch label according to claim 1 or 2 , wherein the thickness of the base material (2) occupying the entire thickness of the stretch film (1) is 30 to 80%. The printed layer (4) is formed on the inner surface of the stretch label body (10) so as to come into contact with the container (5) when the stretch label body (10) is externally fitted to the container (5), and the printed layer ( The stretch label according to any one of claims 1 to 3 , wherein the average surface roughness of 4) is in the range of 0.5 to 5.0 µm.

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