JP2003267437A - Shrink label, and container having shrink label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shrink label which can impart an excellent design property for increasing the purchasing intentions of consumers to a container. <P>SOLUTION: For this shrink label, a printing layer is provided on one surface of a base film. In this case, the base film contains at least two kinds of polymer components from among a polyester-based polymer, a polystyrene-based polymer and a polyolefin-based polymer, and has a phase-separating structure. At the same time, the light-permeability becomes uneven by the phase-separating structure. The phase-separating structure of the base film may be a sea-island structure comprising a sea part and an island part. The printing layer may have a transparent printing part being printed in such a manner that a base pattern generated by the uneven light-permeability of the base film can be seen through. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shrink label and a container with a shrink label attached with the shrink label.

[0002]

2. Description of the Related Art In recent years, shrink labels have been widely used as labels in containers such as polyethylene terephthalate bottles (PET bottles or PET bottles) which have been widely spread as beverage containers. As the shrink label, a label having various print layers formed on the surface of a base film having heat shrinkability is used. By attaching such a shrink label to the container,
An excellent or beautiful design by the printing layer is exhibited, and consumers are motivated to purchase. Therefore, the shrink label is required to have an excellent design property that can increase the consumer's willingness to purchase. Therefore, as a shrink label, for example,
Multicolor printing such as photo printing is applied to a colorless transparent film.

[0003]

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a shrink label and a container with the shrink label, which can impart excellent designability. Another object of the present invention is to provide a shrink label and a container provided with the shrink label, which can give the container an excellent design so as to increase the consumer's willingness to purchase.

[0004]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have made use of a shrink label using a base film containing two or more specific polymer components and having a phase-separated structure. When the above-mentioned base film is produced, the base film has a non-uniform light-transmitting property due to a phase-separated structure, so that a shrink label having a texture that is difficult to obtain by printing can be obtained, and a shrink label that can exhibit an excellent design property that has never been obtained. The inventors have found that the following is obtained, and have completed the present invention.

That is, the present invention is a shrink label in which a printed layer is provided on one surface of a base film, wherein the base film is at least one of a polyester polymer, a polystyrene polymer and a polyolefin polymer. A shrink label comprising two or more polymer components and having a phase-separated structure, and having a non-uniform light transmittance due to the phase-separated structure.

The phase-separated structure of the base film may be a sea-island structure composed of a sea part and an island part.

It is preferable that the printed layer has a transparent printed portion printed so that a ground pattern caused by the non-uniform light transmittance of the base film can be seen through. In this way, since the background pattern is seen through the see-through printing section, excellent texture design is exhibited. Further, a speckled pattern may be developed on the surface by a minute uneven portion including a top portion to which the printing ink is attached and a peripheral portion to which the printing ink is not attached.

The average roughness of the surface of the base film (R
a) may be 0.5 to 1.0 μm.

Furthermore, the present invention provides a container with a shrink label, wherein the shrink label is attached to the container.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the drawings as necessary. The same members or parts may be given the same reference numerals.

FIG. 1 is a schematic view partially showing the shrink label of the present invention and schematically showing the phase separation structure of the base film and the difference in the printing density of the printing layer. In FIG. 1, 1 is a shrink label, 2 is a base film, 2a is a high light-transmitting part of the base film 2 having high light transmittance, 2b is a low light-transmitting part of the base film 2 having low light transmittance, 3 is a printing layer, 3a. Is a non-transparent printing section, 3b is a transparent printing section. In FIG. 1, the shrink label 1 has a print layer 3 having an opaque printed portion 3a and a transparent printed portion 3b formed on the surface of a base film 2 having a high transparent portion 2a and a low transparent portion 2b.

The base film 2 is composed of two or more kinds of polymer components which are incompatible with each other and has a phase separation structure. Also, the base film 2 is
It has been stretched (in particular, substantially uniaxially stretched) and has heat shrinkability. The phase separation structure of the base film 2 has a sea-island structure composed of a sea part and an island part in which different light transmissivity is generated depending on the mutual dispersion state and interface state of the non-uniformly mixed polymer components. Is preferred. Specifically, as the phase separation structure of the base film 2, as shown in FIG. 1, a sea-island structure including a sea part as the high permeability part 2a and an island part as the low permeability part 2b may be used. Alternatively, conversely, a sea-island structure including a sea part as the low transmission part 2b and an island part as the high transmission part 2a may be used.
Further, the low-transmissivity islands may be overlapped with each other or may be in a dense state to form various low-transmission parts 2b. The size of the island portion may be several μm or less, and may be several tens of mm. The thickness of the island is also 0.1 μm
It may be non-uniform as about several μm. The base film 2 has inhomogeneous light transmissivity due to the phase-separated structure such as the sea-island structure including the sea part and the island part in which the different light transmissivities occur. The base film 2 is
Locally, the highly transparent portion 2a is in a semitransparent state or a state close to a semitransparent state, but the entire film is substantially opaque. When such a base film 2 is placed over a light such as a fluorescent lamp, the high transmission part 2a looks bright and the low transmission part 2b looks dark although it is non-uniform. Further, the base film 2 may have glossiness, and in particular,
It is preferable that a non-uniform pearly luster is generated by the phase separation structure such as the sea-island structure.

Examples of the ground pattern of the base film having the above structure include, for example, a pearl paper pattern,
Examples include patterns having a non-uniform light transmission such as cloud-like paper patterns and mica patterns. Further, the surface of the base film may be uneven, and therefore the surface may be such that the ground pattern is three-dimensionally visible. The ground pattern is usually irregular,
It may have a fixed form.

When the base film has a sea-island structure due to the phase-separated structure, the island portions may be oriented or substantially oriented in the stretching direction of the base film stretched substantially in one direction. Good.

In FIG. 1, the high transmission part 2 of the base film 2 is shown.
Since a and the low transmission part 2b are schematically shown, the boundary between the high transmission part 2a and the low transmission part 2b is clear, but the boundary is unclear in most cases. For example, from the central portion of one of the high transmission portion 2a and the low transmission portion 2b (2a or 2b) to the other portion (2b or 2).
A phase-separated state is gradually formed toward the central portion of a), which is an unclear boundary. Further, the light transmissivity in the high transmissive portion 2a and the low transmissive portion 2b is not uniform.

Since the base film 2 has a phase separation structure, the surface roughness (cutoff value 0.8 mm, evaluation length 4.0 m) measured according to JIS B 0601.
m) has an average roughness (Ra) of, for example, 0.5 to 1.
It is about 0 μm.

The base film 2 is composed of at least any two or more polymer components selected from polyester-based polymers, polystyrene-based polymers and polyolefin-based polymers. Therefore, as the material of the base film 2, for example, a polymer component containing a polyester polymer and a polystyrene polymer; a polymer component containing a polyester polymer and a polyolefin polymer; a polymer component containing a polystyrene polymer and a polyolefin polymer A polymer component containing a polyester polymer, a polystyrene polymer and a polyolefin polymer is used. In the present invention, as the material of the base film 2, a polymer component in which a polyolefin-based polymer or a polystyrene-based polymer is mixed with a polyester-based polymer can be preferably used.

Examples of polyester-based polymers include polyethylene terephthalate, polybutylene terephthalate, and various copolyesters. As the copolymerized polyester, for example, terephthalic acid and ethylene glycol are used as the main components of the dicarboxylic acid component and the diol component, respectively, and the aromatic dicarboxylic acid (isophthalic acid, phthalic acid, 4,4′-) is used as the copolymerization component. Biphenyldicarboxylic acid, stilbenedicarboxylic acid, naphthalenedicarboxylic acid, etc.), aliphatic dicarboxylic acid (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.), alicyclic dicarboxylic acid Dicarboxylic acid components such as (cyclohexanedicarboxylic acid), diethylene glycol, polyalkylene glycol, neopentyl glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, cyclohexane-
Copolymerized polyester using a diol component such as 1,4-dimethanol may be used.

Examples of the polystyrene-based polymer include, in addition to polystyrene, styrene and a copolymerizable monomer having copolymerizability with the styrene (eg, butadiene, acrylonitrile, methacrylic acid, acrylic acid, methacrylic acid). Methacrylic acid esters such as alkyl esters, acrylic acid esters such as acrylic acid alkyl esters, etc.) and the like.

Examples of the polyolefin-based polymer include polyethylene (for example, high-density polyethylene, low-density polyethylene, etc.), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-
Ethylene resins such as acrylic acid copolymers; propylene resins such as ethylene-propylene copolymers.

As the base film, for example, two or more kinds of polymer components are mixed (especially, inhomogeneously or incompatiblely), and a mixture of the two or more kinds of polymer components mixed (especially, inhomogeneous). Alternatively, it can be produced by forming a sheet by melt extrusion of a mixture that is mixed in an incompatible mixed state, and then stretching the formed sheet in at least one direction. In addition, by appropriately adjusting the mixing condition (non-uniform degree) when mixing the two or more polymer components, and the melting conditions when melt-extruding, the two or more polymer components can be adjusted to a desired degree. It is possible to form a phase-separated structure in which is phase-separated. Further, when forming a sheet by melt extrusion, the surface roughness of the base film can be adjusted with a cooling roll or the like.

As a more specific example, for example, 100 parts by weight of a copolyester containing terephthalic acid and ethylene glycol as main components of a monomer component and 10 to 40 parts by weight of an ethylene-propylene copolymer as a polyolefin polymer. By adding parts, mixing, melt-extruding with a T die at a temperature of about 270 ° C., cooling with a cooling roll, and then stretching in the width direction with a tenter while being heated to about 70 to 110 ° C., A base film can be made. Further, instead of the ethylene-propylene copolymer, a mixture obtained by adding 10 to 40 parts by weight of a polystyrene-based polymer such as polystyrene or a styrene-butadiene copolymer is formed in the same manner as in the case of the polyolefin-based polymer, A base film can be made. In addition, a base film in which inorganic fine particles such as calcium carbonate are added to the resin (polymer component) to form voids due to the fine particles may be used.

In the shrink label 1 of the present invention, the print layer 3 is formed on the surface of the base film 2 (the surface corresponding to the front side or the outer side when mounted on the container). The printing layer 3 is not particularly limited, but is preferably formed by printing so that the non-uniform light transmittance of the base film 2 can be effectively utilized as a design. For example, as shown in FIG. 1, the printing layer 3
Is a transparent printing portion 3b through which a ground pattern (for example, a pearl paper texture pattern, a cloud paper texture pattern or a mica texture pattern) generated by the nonuniform light transmittance of the base film 2 can be seen through.
And the non-transparent printing portion 3a in which the ground pattern cannot be seen through. Note that, in FIG. 1, since the transparent printing portion 3b and the non-transparent printing portion 3a are schematically shown, the boundary between the transparent printing portion 3b and the non-transparent printing portion 3a becomes clear. However, the boundary may be unclear, for example, the printing density changes due to gradation or the like from the end portion of the transparent printing portion 3b toward the central portion of the transparent printing portion 3a, and thus it is unclear. It may be a boundary. Further, the print density of the non-transparent printing portion 3a and the non-transparent printing portion 3b may be uniform density or non-uniform density. The transparent printing portion 3b is preferably formed by halftone printing of transparent coloring ink such as transparent yellow and transparent grass, and various coloring inks.

In this way, when the transparent printing portion 3b through which the ground pattern caused by the inhomogeneous light transmission of the base film 2 can be seen through is formed as the printing layer 3, a novel design characteristic which has not been available in the past can be obtained. Can be demonstrated.

Further, for example, as shown in FIG. 2, on the inside of the printed portion, on the surface of the base film 21, the top portion to which the printing ink is attached and the periphery such as the slope where the printing ink is not attached are attached. Minute concavo-convex portion 31c consisting of
When the printed layer 3
1 may be formed. FIG. 2 is a schematic diagram of another example that partially shows the shrink label of the present invention and schematically shows the phase separation structure of the base film, the difference in the print density of the print layer, and the like. In FIG. 2, 11 is a shrink label, 21 is a base film, 21a is a high transmissive part of the base film 21, 21b is a low transmissive part of the base film 21, 31 is a printing layer, 31a is an opaque printing part, and 31b is a see-through part. The printing portion 31c is a minute uneven portion including a top portion to which the printing ink is attached and a peripheral portion to which the printing ink is not attached. In the shrink label 11, the base film 21 is the same as the base film 2, but since the minute irregularities 31c are formed, the surface roughness of the base film 21 conforms to JIS B 0601. The average roughness (Ra) based on the surface roughness (cutoff value 0.8 mm, evaluation length 4.0 mm) measured by the above is preferably about 0.7 to 1.0 μm. In the base film 21, the maximum height (Ry) based on the surface roughness (cutoff value 0.8 mm, evaluation length 4.0 mm) measured according to JIS B 0601 is preferably 5.0 μm or less, The ten-point average roughness (Rz) based on the surface roughness (cutoff value 0.8 mm, evaluation length 4.0 mm) measured according to JIS B 0601 is preferably 2.0 to 4.0 μm.

The base film 21 has a surface roughness as described above [for example, an average roughness (R of 0.7 to 1.0 .mu.m).
a)], the printing ink is applied only at the top of the minute unevenness formed on the surface of the base film 21 in the transparent printing portion 31b where the amount of printing ink applied is small due to halftone printing or the like. The printing ink does not adhere to the peripheral portion including the inclined surface, and the minute uneven portion 31c having a spot pattern is formed. That is, a so-called "fish eye" is formed. The size of the speckled pattern varies, but is about 0.1 to 2.0 mm. In the conventional shrink label, when such a "fish eye" is formed, the base film has transparency, resulting in poor printing. However, in the present invention, the base film 2 is not uniform. Since it has a light-transmitting property, it overlaps with the ground pattern, resulting in a suitable printing mode. As described above, the shrink label of the present invention can exhibit a novel design that has never been achieved.

In the present invention, the thickness of the base film is, for example, 30 to 100 μm, preferably 40 to 70 μm. The base film may contain a colorant, but it is preferable that the base film contains no colorant. Even if the base film contains no colorant,
The shrink label can exhibit excellent designability.

If necessary, the base film may contain various additives such as a lubricant, a filler, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, and a flame retardant. .

In the present invention, the base film may be composed of a plurality of layers. Further, an overcoat layer (particularly a transparent overcoat layer) may be provided on the surface of the base film or the printing layer for preventing damage or the like. Furthermore, the surface of the base film on the printing layer side may be subjected to a conventional surface treatment such as corona discharge treatment, plasma treatment, flame treatment, and acid treatment in order to improve printability.

The base film can be stretched by either a tenter system or a tube system.
The stretching treatment is, for example, 70 to 1 by a tenter method.
The stretching is performed at a temperature of about 10 ° C. in the width direction (transverse direction; TD direction) by 2.0 to 6.0 times, preferably by 3.5 to 5.5 times. If necessary, for example, the stretching treatment can be performed in the length direction (longitudinal direction; MD direction) at a low stretching ratio (for example, about 1.5 times or less). The base film in the present invention thus includes a uniaxially oriented film stretched in only one direction, and a biaxially oriented film mainly stretched in one direction and slightly stretched in a direction orthogonal to the direction. Be done. The substantially uniaxially stretched base film thus obtained has an orientation in the transverse direction (mainly the direction in which the stretching treatment was performed) and exhibits a large heat shrinkability in that direction.

The print layer is a layer on which product names, illustrations, handling precautions, etc. are displayed, and it is easy to apply gradation or halftone printing to the transparent printing portions (3b, 31b). Gravure printing is preferable, but it can be formed by printing by a known printing method such as letterpress rotary printing, silk screen printing, flexographic printing, or the like. The printing ink used for forming the printing layer is not particularly limited and can be appropriately selected according to the printing method. The surface on which characters and designs are printed is usually the surface of the shrink label that is not in contact with the adherend (container or the like).

The thickness of the printing layer is not particularly limited,
For example, in the case of gravure printing, it is about 0.1 to 10 μm (preferably 0.2 to 6 μm).

The printing layer may be printed (solid printing) on the entire surface of the base film, but is preferably partially printed. Particularly, in the present invention, since the base film has uneven light transmittance, when the printing layer is partially provided, the uneven light transmittance of the base film is effectively exhibited as a design. Can be made.

In the shrink label of the present invention, the base film is rolled into a cylindrical shape so that the main stretching direction is the circumferential direction, both ends are adhered with an adhesive or the like, and then cut into desired lengths if necessary. It can be used as a tubular shrink label. For example, in addition to the so-called "full shrink label" that covers the side surface of the body of the container almost entirely (from the neck to the bottom of the container or its periphery), use it in the form of "semi-full shrink label" or "half shrink label". You can

The shrinkage rate of the shrink label of the present invention is not particularly limited. For example, the heat shrinkage rate is 90
When immersed in hot water at 0 ° C. for 10 seconds, it is 30 to 80% in one direction X (direction corresponding to the circumferential direction of the container), preferably 40 to 75%. If the heat shrinkage is less than 30%, the shrinkage may be insufficient, and if the heat shrinkage exceeds 80%, the label tends to be distorted, which is not preferable. The heat shrinkage is
It can be adjusted by appropriately selecting the type of resin component of the base film, the composition ratio thereof, the stretching conditions (stretching temperature, stretching ratio, etc.), the heat setting conditions (temperature, time, etc.).

The shrink label of the present invention can be preferably used as a label for various containers, particularly as a label for a container having a three-dimensional curved surface. In such a case, the ground pattern of the base film is represented along the curved surface, and the appearance of the container with a shrink label (design)
Is further enhanced.

In the shrink-labeled container of the present invention, the shrink label covers substantially the entire side surface of the container body or a predetermined portion. Specifically, a container with a shrink label is, for example, a container in which the shrink label formed in the tubular shape is supplied to an automatic label attachment device, cut into a required length, and then filled with a normal content (or a filling container). The container can be manufactured by continuously fitting it to the container (before being processed) so as to cover the side surface of the container body substantially entirely or partially, and thermally shrinking the container by heating. The shrink label fitted in the container may be heat-shrinked by any known method, but for the reason that the temperature is evenly transmitted and the finish of the label is improved, for example, a steam tunnel of about 80 to 100 ° C. (steam and steam) is used. Thermal contraction is preferably carried out by passing through a tunnel filled with steam with dew condensation of steam.

As the container, a plastic container (for example, so-called "blow bottle such as PET bottle")
Besides, various containers such as a glass container (for example, various bottles) and a metal container can be used. As the container, a PET bottle or the like having a cubic curved surface is preferably adopted. Further, the container may be filled with various contents (for example, tea or various juices).

[0039]

According to the shrink label of the present invention, excellent design can be imparted. Therefore, it is possible to provide the container with an excellent design property that can increase consumers' willingness to purchase.

[Brief description of drawings]

FIG. 1 is a schematic pattern diagram partially showing a shrink label of the present invention and schematically showing a phase separation structure of a base film, a difference in printing density of a printing layer, and the like.

FIG. 2 is a schematic diagram that partially shows the shrink label of the present invention and schematically shows the phase separation structure of the base film, the difference in the print density of the print layer, and the like.

[Explanation of symbols]

1 Shrink Label 2 Base Film 2a High Transmission Part 2b of Base Film 2 Low Transmission Part 3 of Base Film 2 Printing Layer 3a Non-transparent Printing Part 3b Transparent Printing Part 11 Shrink Label 21 Base Film 21a High Transmission Part of Base Film 21 21b Low-transmission part 31 in the base film 21 Printing layer 31a Non-transparent printing part 31b Perspective printing part 31c Micro unevenness part consisting of a top part to which printing ink is attached and a peripheral part to which printing ink is not attached

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09F 3/04 G09F 3/04 C F term (reference) 3E067 BB14A CA01 EE01 EE03 EE04 EE09 FB01 GD05 4F100 AK03A AK12A AK41A BA02 DD07B GB16 HB00A HB31B JA03 JN30 YY00 4F210 AA03 AA05 AA07 AA09 AA10 AA13 AA24 AA47 AE01 AG01 RA03 RC02 RG02 RG04 RG43

Claims (6)

[Claims] 1. A shrink label in which a printed layer is provided on one surface of a base film, wherein the base film comprises at least two or more of a polyester polymer, a polystyrene polymer and a polyolefin polymer. A shrink label containing a polymer component and having a phase-separated structure, wherein the phase-separated structure makes the light transmittance inhomogeneous. 2. The shrink label according to claim 1, wherein the phase-separated structure of the base film is a sea-island structure composed of a sea part and an island part. 3. The shrink label according to claim 1, wherein the printed layer has a transparent printed portion printed such that a ground pattern caused by the non-uniform light transmittance of the base film can be seen through. . 4. A top portion on the surface of which printing ink is attached,
The shrink label according to any one of claims 1 to 3, wherein a spotted pattern is developed due to minute irregularities composed of a peripheral portion to which no printing ink is attached. 5. The average roughness (R) of the surface of the base film.
The shrink label according to any one of claims 1 to 4, wherein a) is 0.5 to 1.0 µm. 6. A container with a shrink label, wherein the shrink label according to any one of claims 1 to 5 is attached to the container.