JP2015193409A - Manufacturing method for cylindrical labelled square container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a cylindrical labelled square container wherein the main design of a heat-shrinkable cylindrical label faces frontward by using the heat-shrinkable cylindrical label difficult to have positional deviation for a square container upon external fitting.SOLUTION: A manufacturing method of this invention has: a preparation step for preparing a cylindrical label continuity 1L which includes a heat-shrinkable cylindrical label 1 having a heat-shrinkable base material containing a polystyrene resin and a printing layer, and has a 5 mg/mor less content of a solvent with a specific evaporation rate of less than 50 and a 10 mg/mor less content of a solvent with a specific evaporation rate of 50-100 folded to be flat at first and second folds 61,62 that face each other; and an externally fitting step for opening the flat heat-shrinkable cylindrical label 1 to externally fit it over a square container 5 having four panel faces.

Description

  The present invention relates to a method for manufacturing a rectangular container with a cylindrical label in which a heat-shrinkable cylindrical label is mounted on a rectangular container.

  Conventionally, a labeled container in which a label is attached to various containers such as a beverage container has been widely used. Among them, a rectangular container with a cylindrical label in which a heat-shrinkable cylindrical label is mounted on a rectangular container having a substantially square horizontal cross section is known. Specifically, this type of container has, for example, a trunk portion in which connection corner portions of four panel surfaces are chamfered and four corner surfaces narrower than the panel surface are formed at the corner portions. A heat-shrinkable cylindrical label is mounted on the square container. As this heat-shrinkable cylindrical label, those of a full shrink type, a semi full shrink type, and a half shrink type are known depending on the mounting mode.

Such a heat-shrinkable cylindrical label is heat-shrink mounted on a rectangular container as follows (Patent Document 1).
Flat cylindrical label continuum folded at the first and second folds (cylindrical label continuum conceptually includes a plurality of heat-shrinkable cylindrical labels that are continuously connected to each other. And the first and second folds are re-folded at the third and fourth folds shifted by 90 degrees in the circumferential direction, and then cut into a predetermined length to form one heat shrinkable property. With a cylindrical label attached to the square container, a cylindrical label is obtained, and the heat-shrinkable cylindrical label is opened, fitted into a predetermined position of the rectangular container, and heated. A square container is obtained.

By the way, in the case of a square container, one panel surface is a front surface (the front surface here refers to a surface at the time of display facing the user side so that the user can easily see). Specifically, when displaying a plurality of cylindrical containers with a cylindrical label having a heat-shrinkable cylindrical label mounted on the cylindrical container, the main design of the heat-shrinkable cylindrical label is the front because the container is circular. Rotate it to face the display. On the other hand, when displaying a plurality of rectangular containers with a cylindrical label in which a heat-shrinkable cylindrical label is attached to the rectangular container, the panel surfaces of the adjacent rectangular containers with a cylindrical label are aligned facing each other. It is displayed so that one panel surface faces the front. For this reason, when the heat-shrinkable cylindrical label is externally fitted to the square container, the heat-shrinkable tubular label is designed so that the main design of the heat-shrinkable cylindrical label exactly matches the panel surface of the square container. The label must be externally fitted in place on the square container.
However, the heat-shrinkable cylindrical label may be slightly displaced in the circumferential direction from the predetermined position when it is externally fitted. The square container with a cylindrical label in which the heat-shrinkable cylindrical label in a misaligned state is directly heat-shrinked and attached to the square container is more attractive than the square container with a cylindrical label attached to a predetermined position. Since it is bad, it is removed as a defective product. When the number of defective products increases, the yield deteriorates, and improvement is required.

JP 2006-056552 A Japanese Patent No. 4976845

  An object of the present invention is to manufacture a rectangular container with a cylindrical label using a heat-shrinkable cylindrical label that is not easily displaced in a rectangular container during external fitting, and the main design of the heat-shrinkable cylindrical label is directed to the front. Is to provide a method.

The inventors of the present invention have intensively studied the cause of displacement of the heat-shrinkable cylindrical label when it is externally fitted, and focused on the solvent contained in the heat-shrinkable cylindrical label.
A heat-shrinkable cylindrical label is usually provided with a printing layer for imparting a design, but the ink of the printing layer often contains a solvent (Patent Document 2). There is a possibility that the solvent in the ink does not completely volatilize and remains in the heat-shrinkable cylindrical label, which is considered to be a cause of the displacement of the heat-shrinkable cylindrical label. In particular, it is considered that a low-volatile solvent having a low specific evaporation rate remains for a long period of time, and a base material containing a polystyrene resin easily absorbs the low-volatile solvent and accumulates therein. Under such estimation, the present inventors have arrived at the present invention.

The manufacturing method of the cylindrical container with a cylindrical label of this invention has the heat-shrinkable base material containing a polystyrene-type resin, and a printing layer, The amount of the solvent volatilized by heating for 30 minutes at 80 degreeC is a unit area. A heat-shrinkable cylindrical label whose content of the solvent having a specific evaporation rate of less than 50 is 5 mg / m ² or less and whose content of the solvent having a specific evaporation rate of 50 to 100 is 10 mg / m ² or less. A preparatory process for preparing a cylindrical label continuous body including the first and second folds facing each other in a flat shape; opening a flat heat-shrinkable cylindrical label; And an external fitting process for externally fitting the rectangular container.

In a preferred production method, the content of the solvent having a specific evaporation rate of 50 to 100 in the heat-shrinkable cylindrical label is more than zero and 10 mg / m ² or less.
In a preferred production method, the content of the solvent having a specific evaporation rate of less than 50 in the heat-shrinkable cylindrical label is more than zero and 5 mg / m ² or less.
A preferable manufacturing method is as follows: a cylindrical label continuous body or a heat-shrinkable cylindrical label folded in a flat shape by the first and second folds before the external fitting step, and the first and second folds. Further comprises a refolding step for refolding into a flat shape at different third and fourth folds.
In the outer fitting process, a preferable manufacturing method is such that the first, second, third, and fourth folds correspond to the corner surfaces between the panel surfaces of the rectangular container, respectively, and the heat shrinkability. A cylindrical label is fitted on the square container.
In a preferred production method, the yield point strength of the heat-shrinkable cylindrical label is greater than the yield point strength of the heat-shrinkable substrate.

  According to the method for manufacturing a rectangular container with a cylindrical label according to the present invention, the heat-shrinkable cylindrical label can be externally fitted at a predetermined position of the rectangular container, and the main design of the heat-shrinkable cylindrical label is directed to the front. Can be easily manufactured.

The perspective view of a heat-shrinkable cylindrical label. The top view which shows the state which folded the heat-shrinkable cylindrical label flatly. Sectional drawing cut | disconnected by the III-III line | wire of FIG. The front view of a square container with a cylindrical label. The perspective view of a square container. The partial abbreviation perspective view of a cylindrical label continuum. The schematic reference figure which shows the flow on a manufacturing line until it forms a heat-shrinkable cylindrical label from a cylindrical label continuous body, and it mounts | wears with a square container. The partial omission perspective view which shows the state which refolded the cylindrical label continuous body (or heat-shrinkable cylindrical label). (A) is a perspective view which shows the heat-shrinkable cylindrical label opened in the substantially square shape, (b) is the state which carried out the external fitting of the said heat-shrinkable cylindrical label to the square container from upper direction. Schematic reference diagram seen. (A) is a perspective view which shows the heat-shrinkable cylindrical label opened to the substantially square shape based on other embodiment, (b) externally fitted the said heat-shrinkable cylindrical label to the square container. The schematic reference figure which looked at the state from the top.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In this specification, the “surface” of the heat-shrinkable substrate or the like refers to the outer surface of the cylinder when it is formed into a cylindrical shape (that is, when a heat-shrinkable cylindrical label is formed). “Back” refers to the inner surface of the cylinder. In addition, “first”, “second”, and the like may be added in front of a term, but this term is added to distinguish terms, and does not mean superiority, inferiority, order, or the like. Furthermore, the description “PPP to QQQ” means “PPP or more and QQQ or less”.
In each figure, it should be noted that the thickness and dimensions are different from the actual ones.

[Heat-shrinkable cylindrical label]
1 to 3, the heat-shrinkable cylindrical label 1 includes a heat-shrinkable base material 2 containing a polystyrene-based resin and a printed layer 3 laminated on the heat-shrinkable base material 2. The heat-shrinkable cylindrical label 1 is configured by rolling the heat-shrinkable base material 2 having the printed layer 3 with one direction as a circumferential direction and overlapping and bonding both end portions thereof. The portion where the both side end portions are bonded is referred to as a center seal portion 4.
The heat-shrinkable cylindrical label 1 may be provided with a layer other than the printing layer 3. Other layers include a protective layer for protecting the substrate, an adhesive layer made of a heat-sensitive adhesive provided on the inner surface of the heat-shrinkable cylindrical label 1 to fix the heat-shrinkable cylindrical label 1 to the container, Examples thereof include a sliding layer provided on the inner surface of the cylindrical body in order to improve the sliding property of the shrinkable cylindrical label 1 with respect to the container. Other layers are not shown. In addition, the heat-shrinkable cylindrical label 1 may be provided with a known configuration such as a perforation line for cutting and a cutting line.

The heat-shrinkable substrate 2 is a film having heat-shrinkability in at least one direction (one direction becomes the circumferential direction when formed in a cylindrical shape). The heat shrinkability refers to a property of shrinking when heated to a predetermined temperature (for example, 70 ° C. to 100 ° C.).
As the heat-shrinkable base material 2, a material that slightly heat-shrinks or stretches in the other direction (the other direction is a direction orthogonal to the one direction in the surface of the base material) may be used.
The heat shrinkage rate of the heat-shrinkable substrate 2 is not particularly limited. The heat shrinkage rate in one direction when the heat-shrinkable substrate 2 is heated to 90 ° C. is, for example, 30% or more, preferably 40% or more, more preferably 50% or more. In addition, when the heat-shrinkable base material 2 is slightly heat-shrinked or stretched in the other direction, the heat shrinkage rate in the other direction when heated to 90 ° C. is, for example, −3% to 15%. The minus of the heat shrinkage rate in the other direction means thermal expansion.

The heat shrinkage rate when heated to 90 ° C. is the length of the base material before heating (original length) and the length of the base material after dipping the base material in warm water at 90 ° C. for 10 seconds ( It is a ratio of the length after immersion) and is obtained by substituting into the following formula.
Formula: heat shrinkage rate (%) = [{(original length in one direction (or other direction)) − (length after immersion in one direction (or other direction))} / (one direction (or other direction) ) Original length)] × 100.

The heat-shrinkable substrate 2 is not particularly limited on the condition that it contains a polystyrene resin. For example, a single layer film of a polystyrene resin, a multilayer film of a polystyrene resin, or any one of the above polystyrene resins Examples include a laminate of a film and one or more other resin films.
Examples of the polystyrene resin include homopolymers or copolymers of styrene monomers such as general-purpose polystyrene which is a homopolymer of styrene; high impact polystyrene (HIPS) obtained by graft-polymerizing styrene to a synthetic rubber. A styrene-conjugated diene copolymer, which is a copolymer of a styrene monomer and a diene monomer (conjugated diene) such as butadiene or isoprene, represented by a styrene-butadiene block copolymer (SBS, etc.) Copolymer; Styrene-polymerizable unsaturated carboxylic acid ester copolymer which is a copolymer of styrene monomer and (meth) acrylic acid ester monomer; Styrene-conjugated diene-polymerizable unsaturated carboxylic acid ester Copolymer: Transparent, rubber-grafted copolymer of styrene monomer and (meth) acrylate monomer Impact polystyrene (graft HIPS), and mixtures thereof.
Examples of the other resins include polyester resins such as polyethylene terephthalate and polylactic acid; olefin resins such as polypropylene; cyclic olefin resins; and thermoplastic resins such as vinyl chloride resins, or a mixture of two or more. Etc.
When using a laminate of the polystyrene resin film and another resin film, it is preferable that at least the surface layer or the back layer is a polystyrene resin film, the surface layer and the back layer are polystyrene films, and the intermediate layer is another More preferably, it is a resin film.
The thickness of the heat-shrinkable substrate 2 is not particularly limited, and is, for example, 20 μm to 80 μm, preferably 30 μm to 50 μm, and more preferably 35 μm to 45 μm. According to the present invention, even when a relatively thin heat-shrinkable substrate 2 of 30 μm to 50 μm is used, the heat-shrinkable cylindrical label 1 can be externally fitted at a predetermined position of the square container.

The heat-shrinkable substrate 2 may be either transparent or opaque, but a transparent substrate is used when the printed layer 3 is provided on the back surface as shown.
Transparent includes colored transparent or colorless and transparent, but is preferably colorless and transparent.
The degree of transparency of the heat-shrinkable substrate 2 is not particularly limited as long as the design of the printing layer 3 can be visually recognized from the surface side. The total light transmittance of the heat-shrinkable substrate 2 is, for example, 70% or more, preferably 80% or more, and more preferably 90% or more. The total light transmittance refers to a value measured by a measuring method based on JIS K7105 (plastic optical property testing method).

The yield point strength of the heat-shrinkable substrate 2 is smaller than the yield point strength of the heat-shrinkable cylindrical label 1. For example, the yield point strength of the heat-shrinkable substrate 2 is 13 to 19 N / 15 mm, and preferably 15 to 17 N / 15 mm.
The yield point strength can be measured by a tensile test using a tensile tester in accordance with JIS K 7127. Yield point strength refers to the tensile load (load at yield) when a specimen reaches the yield point. Specific measurement methods are as in the following examples.

The print layer 3 includes, for example, a one-layer or multi-layer design layer on which a design such as a product name, a company name, an explanatory note, and a design is displayed, or a single-layer or multi-layer design layer and a background layer. The design layer is formed by printing a color ink by single color or multicolor printing by a known printing method such as a gravure printing method or a flexographic printing method. The print layer 3 may include a background layer in addition to the design layer. The background layer is provided for the purpose of highlighting the design. The background layer can be formed, for example, by printing a white ink containing a white pigment or the like, a silver ink containing an aluminum powder or the like on the back surface of the design layer in a solid form.
The thickness of the printing layer 3 is not particularly limited and is, for example, about 0.1 μm to 5 μm. However, when the printing layer 3 has a multilayer structure, it may exceed 5 μm.

  The printing layer 3 includes a layer formed of a solvent-type ink containing a solvent. When the printing layer 3 has a multilayer structure, all the layers may be composed of the solvent-type ink, or an ink other than the solvent-type ink may be partially used. According to the present invention, the heat-shrinkable cylindrical label 1 can be externally fitted at a predetermined position of a square container even when solvent-based ink is directly printed on the heat-shrinkable base material 2 of polystyrene resin.

The solvent-type ink contains a binder resin, a colorant, and a solvent.
The binder resin is not particularly limited, and examples thereof include acrylic resins, cellulose resins, urethane resins, polyester resins, and vinyl chloride resins. Especially, since it is excellent in the adhesiveness with respect to the heat-shrinkable base material 2, an acrylic resin, a cellulose resin, a urethane-type resin, or at least 2 types of mixed resin chosen from these are preferable.
The colorant is appropriately selected from dyes or pigments according to the color of the ink, and an organic pigment or an inorganic pigment is preferably used. Examples of pigments include white pigments such as titanium oxide blended in white ink; aluminum powder blended in silver ink; carbon black blended in black ink; blue pigments such as copper phthalocyanine blue blended in color ink Red pigments such as condensed azo pigments, yellow pigments such as azo lake pigments, and the like.

Examples of the solvent include organic solvents such as a low volatile solvent, a medium volatile solvent, and a high volatile solvent.
Here, in this specification, the low volatile solvent is a solvent having a specific evaporation rate of less than 50, the medium volatile solvent is a solvent having a specific evaporation rate of 50 to 100, and the high volatile solvent is 100% in specific evaporation rate. A solvent exceeding
The specific evaporation rate refers to the evaporation rate of the solvent that evaporates from a unit area per unit time at 25 ° C., and is expressed as a percentage of the evaporation rate of the sample with respect to the evaporation rate of n-butyl acetate. As a specific measuring method, for example, two hooded chemical balances capable of supplying nitrogen gas are used. Place a petri dish of 10 cmφ containing 5C (9 cmφ), take n-butyl acetate on one side and 0.7 mL each of the sample on the other side, and simultaneously supply nitrogen gas at a flow rate of 30 NL / min. The time until the weight reduction rate of the sample reaches 90% is measured and can be calculated by the following formula.
Specific evaporation rate (%) = T ₁ / T ₂ × 100
T ₁ : Time required for 90% weight loss of n-butyl acetate T ₂ : Time required for 90% weight loss of sample

The low-volatile solvent is not particularly limited, and examples thereof include ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol n-propyl ether, propylene glycol n-butyl ether, propylene glycol t-butyl ether, and ethylene glycol monoethyl ether. Examples include acetate, 3-methyl-3-methoxybutyl acetate, 1,2-dichlorobenzene, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and 3-methoxybutyl acetate. Among these, from the viewpoint of compatibility with the binder resin in the ink and leveling properties, it is preferable to use glycol ethers and glycol ether esters having a specific evaporation rate of less than 50.
The content of the low-volatile solvent is preferably as small as possible, but inks (particularly color inks) that do not contain any low-volatile solvent have a lower resolubility of the binder resin and printing. Streaks appear in the layer 3 and printing suitability decreases. For this reason, it is preferable that 0.1 mass% or more of low-volatile solvents are contained with respect to the whole solvent, and it is more preferable that 0.5 mass% is further contained. On the other hand, since the low-volatile solvent is difficult to volatilize, the low-volatile solvent is likely to remain after the printing layer 3 is formed, and according to the study by the present inventors, the low-volatile solvent is a heat-shrinkable group containing a polystyrene resin. It is easily absorbed by the material 2. For this reason, there is a possibility that the low-volatile solvent contained in the ink is almost left in the heat-shrinkable cylindrical label 1, and if an ink containing too much low-volatile solvent is used, the heat-shrinkable cylindrical label is used. The rigidity of the label 1 is reduced. From this viewpoint, the content of the low-volatile solvent in the ink is preferably 3% by mass or less, and more preferably 1% by mass or less.

The medium volatile solvent is not particularly limited, and examples thereof include propylene glycol monomethyl ether.
The content of the medium volatile solvent is preferably as small as possible. However, the ink containing no medium volatile solvent (particularly white ink) has a low resolubility of the binder resin, and printing. Streaks appear in the layer 3 and printing suitability decreases. For this reason, the medium volatile solvent is preferably contained in an amount of 0.1% by mass or more, more preferably 0.5% by mass with respect to the whole solvent. On the other hand, since the medium volatile solvent is difficult to volatilize, the medium volatile solvent is likely to remain after the printing layer 3 is formed. Therefore, there is a possibility that most of the medium volatile solvent contained in the ink remains in the heat-shrinkable cylindrical label 1. Yes, it contributes to lowering the rigidity of the heat-shrinkable cylindrical label 1. From this viewpoint, the content of the volatile solvent in the ink is preferably 5% by mass or less, and more preferably 3% by mass or less.

The highly volatile solvent is not particularly limited, and alcohol solvents such as methanol, ethanol, isopropyl alcohol and n-propyl alcohol; ester solvents such as ethyl acetate and propyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone Aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; glycols such as ethylene glycol and propylene glycol; And the like. Among these, alcohol-based solvents and ester-based solvents are preferable, and mixed solvents of alcohol-based solvents and ester-based solvents are more preferable from the viewpoints of compatibility with resins and difficulty in swelling or dissolving the heat-shrinkable substrate 2. .
The content of the highly volatile solvent in the ink is the remaining amount of the solvent excluding the low volatile solvent and the medium volatile solvent.
In addition, the kind of each said solvent and its compounding quantity are suitably set according to the kind of ink, such as color ink, white ink, and silver ink. Generally, the total amount of the solvent with respect to the whole of these inks is, for example, 20 to 70% by mass, although it varies depending on the presence or absence and the type of the colorant.

In the present invention, the content of the solvent (low volatile solvent) having a specific evaporation rate of less than 50 is 5 mg / m ² or less, and the content of the solvent having a specific evaporation rate of 50 to 100 (medium volatile solvent) is 10 mg / m ^2. m ² heat-shrinkable cylindrical label 1 or less is used. Preferably, the heat-shrinkable cylinder has a low volatile content of more than zero and 5 mg / m ² or less, and a medium volatile solvent content of more than zero and 10 mg / m ² or less or does not contain a medium volatile solvent. A shaped label 1 is used.
The content of the low-volatile solvent of the heat-shrinkable tubular label 1 is more preferably 3 mg / ^{m 2} or less than zero, particularly preferably from 2 mg / ^{m 2} or less than zero, 1 mg / ^{m 2} greater than zero or less Is most preferred. When the heat-shrinkable cylindrical label 1 contains an intermediate volatile solvent, the content of the solvent is preferably more than zero and not more than 8 mg / m ² , more preferably more than zero and 7 mg / m ^2. The following is particularly preferable, and more preferably more than zero and 5 mg / m ² or less.
Moreover, the one where content of the highly volatile solvent of the said heat-shrinkable cylindrical label 1 is small is preferable, for example, is 5-30 mg / m < ² >, Preferably, it is 10-25 mg / m < ² >.
Furthermore, the yield point strength of the heat-shrinkable cylindrical label 1 is greater than the yield point strength of the heat-shrinkable substrate 2. For example, the yield point strength of the heat-shrinkable cylindrical label 1 is 14 to 20 N / 15 mm, preferably 16 to 18 N / 15 mm.
The yield point strength can be measured by the method of the following example.

The solvent contained in the heat-shrinkable cylindrical label 1 is mainly caused by the solvent contained in the ink used for forming the printing layer 3.
The heat-shrinkable cylindrical label 1 containing the solvent of each content can be obtained by appropriately adjusting the solvent composition of each ink and the coating amount of each ink.
The content of each solvent is determined by sampling a part of the heat-shrinkable cylindrical label 1 at an arbitrary location and heating it at 80 ° C. for 30 minutes to detect the solvent volatilized by gas chromatography. It is converted per area. The detailed measurement method is as described in the examples.
Since it is considered that not all of the solvent contained in the sampled sample is volatilized, the solvent content of the heat-shrinkable cylindrical label 1 is a value measured under the above conditions. I want to be.
In addition, since the amount of solvent in the heat-shrinkable cylindrical label 1 changes due to volatilization, the content of each solvent is 23 ° C. and 60 ± 5% RH environment after the heat-shrinkable cylindrical label 1 is produced. It is the value measured after being left for 48 hours.

[Square container with cylindrical label]
As shown in FIG. 4, a rectangular container 10 with a cylindrical label according to the present invention includes a rectangular container 5 having four panel surfaces 52a, and a heat-shrinkable cylindrical label attached to the rectangular container 5 by heat-shrinking. 1.
As shown in FIG. 5, the rectangular container 5 includes a bottom surface portion 51, a body portion 52, a shoulder portion 53 that is formed above the body portion 52 and gradually decreases in circumference, and above the shoulder portion 53. And a cap portion 54 for opening and closing the pouring portion provided in the. The body portion 52 of the rectangular container 5 has an outer shape in a horizontal section formed in a substantially square shape such as a substantially square shape or a substantially rectangular shape. Note that the “substantially” of the substantially square shape means a shape allowed in the technical field to which the present invention belongs, for example, a shape in which a corner is chamfered, and a part of a side is slightly inflated or depressed. The shape and the shape in which the entire side is slightly curved are included.
The body 52 of the rectangular container 5 in the illustrated example has a substantially square shape in the horizontal cross section, and has four panel surfaces 52a.
Specifically, the trunk portion 52 mainly has a basic mode in which four panel surfaces 52a are combined in an orthogonal direction, and a corner portion generated at a connection portion between adjacent panel surfaces 52a is chamfered, and each of the panel surfaces 52a is chamfered. Corner surfaces 52b are respectively formed therebetween. The corner surface 52b is narrower than the panel surface 52a and is integrally formed with an angle of about 45 degrees with respect to the panel surface 52a. The panel surface 52 a and the corner surface 52 b are formed up to the shoulder portion 53. In the illustrated example, a reinforcing rib 52c (reinforcing recess) is formed on the panel surface 52a, but such a rib may not be formed.
The material of the square container 5 is not particularly limited, and a conventionally known material can be used. Typically, a relatively thin flexible plastic resin container such as a polyethylene terephthalate container can be exemplified. It may be made of glass or metal.

The heat-shrinkable cylindrical label 1 is heat-shrink mounted from a part of the shoulder portion 53 of the square container 5 to the upper portion of the trunk portion 52. The heat-shrinkable cylindrical label 1 in the illustrated example is a so-called half-shrink that is mounted on the upper portion of the body portion 52. By setting the length of the heat-shrinkable cylindrical label 1 as appropriate, full shrinkage is achieved. Or it can also be changed to semi-full shrink.
In the rectangular container 10 with the cylindrical label, the heat-shrinkable cylindrical label 1 is aligned so that the main design of the heat-shrinkable cylindrical label 1 corresponds to one panel surface 52a of the rectangular container 5. A rectangular container 5 is attached. However, the design is not shown.

[Method for producing rectangular container with cylindrical label]
<Preparation process of cylindrical label continuum>
As shown in FIG. 6, the long heat-shrinkable base material 2 </ b> L provided with the printing layer is rounded into a cylindrical shape, and both side edges along the longitudinal direction are overlapped and bonded to attach the center seal portion 4. By forming, the cylindrical label continuous body 1L is formed. This long heat-shrinkable base material L2 is conceptually composed of one heat-shrinkable base material 2 in which the design corresponding to one heat-shrinkable cylindrical label is represented on the printing layer 3 in the longitudinal direction. Is connected continuously. In other words, the print layer 3 having a single design is repeatedly provided in the longitudinal direction on the long heat-shrinkable base material L2. The cylindrical label continuous body 1L is conceptually a long cylindrical body in which a plurality of heat-shrinkable cylindrical labels 1 are continuously connected. Accordingly, the cylindrical label continuous body 1L includes a plurality of heat-shrinkable cylindrical labels 1. As will be described later, the individual heat-shrinkable cylindrical labels 1 are obtained by cutting the cylindrical label continuous body 1L into a predetermined length.
The long shape means a shape in which the length in one direction (longitudinal direction) is sufficiently longer than the width direction (short direction), for example, the length in the long direction is the length in the short direction. 10 times or more, preferably 20 times or more.
The formed cylindrical label continuous body 1L is folded in a flat shape by two fold lines 61 and 62 facing each other in the circumferential direction. The two fold lines 61 and 62 are referred to as first and second fold lines. The first fold line 61 and the second fold line 62 are located on a straight line passing through the center of the cylinder when opened in a cylindrical shape, and extend in the longitudinal direction of the cylindrical label continuous body 1L.
The cylindrical label continuous body 1L that has been flattened by being folded at the first and second folds 61 and 62 is usually wound around a roll to form a roll body 11L, which is stored and transported.

  In addition, in mass production of the cylindrical container 10 with the cylindrical label, the manufacture of the cylindrical label continuous body 1L and the manufacture of the rectangular container 10 with the cylindrical label are generally divided and the cylindrical label continuous body 1L is manufactured. The person who manufactures and the person who manufactures the rectangular container 10 with the cylindrical label using the same are often different. That is, generally, a label maker manufactures a cylindrical label continuous body 1L, winds it into a roll shape, sells the roll body to another person, and the other person uses a labeler described later to form a cylindrical shape. The manufacturing method of the present invention is carried out by the flow of taking out the heat-shrinkable cylindrical label 1 from the label continuum 1L and mounting it on the rectangular container 5 to produce the rectangular container 10 with a cylindrical label.

<Refolding process>
The roll body is loaded into a labeler (a labeler that may be provided with a folding device).
FIG. 7 shows an outline of a series of flows from the labeler to obtain one heat-shrinkable cylindrical label 1 from the cylindrical label continuous body 1L, to externally fit it to the square container 5 and to heat-shrink it. It is a reference figure.
In addition, in FIG. 7, although the cylindrical label continuous body 1L pulled out from the roll body is illustrated so as to be sent in the downward direction, in actual equipment, various types such as a right direction, an upward direction, and an oblique direction are provided. May be sent in the direction.

A flat cylindrical label continuous body 1L is pulled out from the roll body in the longitudinal direction and conveyed to the production line.
In the middle of the process, the cylindrical label continuous body 1L is folded as necessary. That is, since the cylindrical label continuous body 1L folded in a flat shape is difficult to open in a shape that easily covers the rectangular container 5, a folding process is performed on the cylindrical label continuous body 1L. As shown in FIG. 8, the folding process is performed by opening the flat cylindrical label continuous body 1L once so that the first and second folds 61 and 62 at the time of initial flattening overlap each other. 64 (third and fourth folds) is a process of folding in a flat shape.
Specifically, as shown in FIG. 7, after the flat cylindrical label continuous body 1 </ b> L is inserted through the tetra guide 71 and opened, the first and second folds 61 and 62 are 90 in the circumferential direction. It folds flat again at the third and fourth folds 63 and 64 extending in the longitudinal direction with a degree shift. Formation (re-folding) of the third and fourth folds 63 and 64 is performed by passing the cylindrical label continuous body 1 </ b> L between a pair of pinch rollers 72 provided on the downstream side of the tetra guide 71. Preferably, each fold 61, 62, 63, 64 is formed so that the third fold 63 is located in the vicinity of the center seal portion 4.

<Cutting process>
The cylindrical label continuous body 1L which has been folded back again into a flat shape is cut into a predetermined length using a cutting tool 73 such as a guillotine cutter.
Thus, the flat heat-shrinkable cylindrical label 1 in which the four folds 61, 62, 63, 64 are formed is obtained.

<Opening and fitting process>
The obtained flat heat-shrinkable cylindrical label 1 is opened.
Specifically, the flat heat-shrinkable cylindrical label 1 is sent to the mandrel 74 by the transport device 75 and inserted therethrough. The outer shape of the mandrel 74 is substantially flat in its upper part (inverted trapezoidal shape when viewed from the front (see FIG. 7) and generally triangular with an apex when viewed from the side), and gradually decreases toward the bottom. The heat-shrinkable cylindrical label 1 is opened while passing through the mandrel 74.
The heat-shrinkable cylindrical label 1 opened while passing through the mandrel 74 is transported by the transport device 75 and pulled out from the lower end 74a of the mandrel 74, and then substantially at the four folds 61, 62, 63, 64. It becomes a substantially rectangular shape bent at a right angle (see FIG. 9A). In FIG. 7, reference numeral 1 ′ is attached to a heat-shrinkable cylindrical label that has come out of the mandrel 74 and opened in a substantially square shape.
The heat-shrinkable cylindrical label 1 opened in a substantially square shape is externally fitted to the square container 5. In one embodiment, the four folds 61, 62, 63, 64 of the substantially quadrangular heat-shrinkable cylindrical label 1 correspond to the substantially central portions of the four corner surfaces 52 b of the rectangular container 5, respectively. (In other words, the four sides of the substantially quadrangular heat-shrinkable cylindrical label 1 correspond to the four corner surfaces 52b of the rectangular container 5), and the heat-shrinkable cylindrical label 1 is replaced with the rectangular container. 5 (see FIG. 9B). As described above, since the refolding process is performed so that the third fold 63 is positioned in the vicinity of the center seal portion 4, the center seal portion 4 is positioned on one corner surface 52 b of the rectangular container 5. .
In addition, when the heat-shrinkable cylindrical label 1 is a half shrink type, as shown in FIG. 7, in order to stop the lower side of the heat-shrinkable cylindrical label 1 at the middle part of the trunk portion 52 of the square container 5 A support member 76 is provided in the middle of the body 52 of the square container 5.

<Heating process>
The heat-shrinkable tubular label 1 is heated at a predetermined position of the square container 5 by applying a heat medium such as steam from the outside of the externally-fitted heat-shrinkable tubular label 1 to heat the heat-shrinkable tubular label 1. A rectangular container 10 with a cylindrical label to which is attached is obtained.

In addition, said each process is not limited to when performed in said order, The order can be changed suitably.
For example, in the above, the process is performed in the order of the folding process, the cutting process, and the opening process. However, the process may be performed in the order of the folding process, the opening process, and the cutting process. It can be changed as appropriate, for example, in order. When performing in the order of the refolding step, the opening step, and the cutting step, after obtaining the cylindrical label continuous body 1L that has been flattened again by folding the flat heat-shrinkable cylindrical label 1 prepared in the preparation step The mandrel 74 is opened in a substantially rectangular shape, and the cylindrical label continuous body 1L in an opened state is cut into a predetermined length using a cutting tool such as a circle cutter, and the heat-shrinkable cylinder is opened in a substantially rectangular shape. The shape label 1 is obtained and this is externally fitted to the square container 5. When performing in order of a cutting process, a fold-back process, and an opening process, the flat heat-shrinkable cylindrical label 1 prepared in the preparation process is cut into a predetermined length by using a cutting tool, and flat heat-shrinkage is performed. The tubular label 1 is obtained, and is folded again to obtain a flat heat-shrinkable tubular label 1 which is opened in a substantially rectangular shape and is fitted on the square container 5.

Further, in the above, the four folds 61, 62, 63, 64 of the heat-shrinkable cylindrical label 1 are opened in a substantially square shape so that they correspond to the substantially central portions of the four corner surfaces 52 b of the rectangular container 5, respectively. Although the heat-shrinkable cylindrical label 1 is externally fitted to the square container 5, for example, as shown in FIG. 10B, the four sides of the substantially quadrangular heat-shrinkable cylindrical label 1 are The four folds 61, 62, 63, 64 of the substantially square heat-shrinkable cylindrical label 1 correspond to the four corner surfaces 52 b of the rectangular container 5, respectively. The heat-shrinkable cylindrical label 1 may be externally fitted to the square container 5 so as to correspond to the substantially central portions of the two panel surfaces 52a. However, since it is easier to position the heat-shrinkable cylindrical label 1 on the panel surface 52a wider than the corner surface 52b, it is easier to position the heat-shrinkable cylindrical label 1 as described above. Furthermore, it is preferable that the heat-shrinkable cylindrical label 1 is externally fitted to the square container 5 with the four fold lines 61, 62, 63, 64 corresponding to the four corner surfaces 52b.
Further, in the above, the folds 61, 62, 63, 64 are formed so that the third fold 63 is positioned in the vicinity of the center seal portion 4, but for example, as shown in FIG. The folds 61, 62, 63, 64 may be formed so that the center seal portion 4 is positioned at an intermediate position between the first fold 61 and the third fold 63. If the heat-shrinkable cylindrical label 1 is externally fitted so that a crease is formed at such a position and the four sides of the substantially quadrangular heat-shrinkable cylindrical label 1 correspond to the corner surfaces 52b, respectively. The center seal portion 4 is positioned on one corner surface 52 b of the mold container 5.
Furthermore, the heat-shrinkable cylindrical label 1 is externally fitted to the square container 5 so that the center seal portion 4 corresponds to one panel surface 52a (for example, the panel surface on the side surface side among the four panel surfaces). May be. For example, as shown in FIG. 10A, the heat-shrinkable cylindrical label 1 in which the folds 61, 62, 63, 64 are formed is opened, and the four folds 61, 62, 63, 64 are formed into square containers. 5, the center seal portion 4 can be arranged on one panel surface 52a so that the heat-shrinkable cylindrical label 1 can be mounted.

In the present invention, the content of the solvent (low volatile solvent) having a specific evaporation rate of less than 50 is 5 mg / m ² or less, and the content of the solvent having a specific evaporation rate of 50 to 100 (medium volatile solvent) is 10 mg / m ^2. m ² is used heat-shrinkable cylindrical label 1 below.
By using the heat-shrinkable cylindrical label 1, the heat-shrinkable cylindrical label 1 can be externally fitted at a predetermined position of the rectangular container 5, and the main design of the heat-shrinkable cylindrical label 1 faces the front. The labeled rectangular container 10 can be easily manufactured.

Since heat-shrinkable cylindrical labels that contain a relatively large amount of solvent, especially low-volatile solvents, do not fold the folds firmly, heat should be applied so that the folds are at a predetermined position such as the corner surface of a rectangular container. Even if the labeler is designed so that the shrinkable cylindrical label can be fitted externally, the heat-shrinkable cylindrical label is often fitted externally in a state of being slightly rotated in the circumferential direction.
In the present invention, the content of the low volatile solvent is made relatively small, and further, the yield point strength of the heat-shrinkable cylindrical label is made larger than the yield point strength of the heat-shrinkable base material, so that the crease is firmly established. The heat-shrinkable cylindrical label can be externally fitted at a predetermined position. Therefore, according to this invention, mounting | wearing deviation of the heat-shrinkable cylindrical label with respect to a square container can be suppressed.

  Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples.

[Materials used]
Heat-shrinkable substrate: a uniaxially stretched polystyrene film having a thickness of 40 μm mainly composed of a styrene-conjugated diene copolymer. The yield strength of this polystyrene film was measured and found to be 16.8 N / 15 mm.
Color ink: Gravure ink containing 10 parts by mass of acrylic resin, 10 parts by mass of copper pigment, and 80 parts by mass of the solvent shown in Table 1.
White ink: A gravure ink containing 10 parts by mass of an acrylic resin, 45 parts by mass of a titanium oxide pigment, and 45 parts by mass of a solvent shown in Table 1. As shown in Table 1, seven types of white ink having different solvent compositions were prepared.
In Tables 1 and 2, “IPA” is isopropyl alcohol, “PGM” is propylene glycol monomethyl ether, “EnP” is ethylene glycol monopropyl ether, and “PnP” is propylene glycol n-propyl. Each represents an ether.

[Measurement of yield strength]
A test piece was cut out so that the length in the direction orthogonal to the main heat shrink direction was 200 mm and the length in the main heat shrink direction was 15 mm, and both ends of the test piece in one direction were held with chucks (distance between chucks: 100 mm). ), The yield strength in one direction was measured by a tensile test method according to JIS K 7127.

[Measurement of solvent content]
A test piece was cut out to 10 cm × 10 cm, put into a 500 ml conical flask under normal temperature and normal pressure, and sealed with a silicone rubber stopper, and then the whole flask was heated at 80 ° C. for 30 minutes. The test piece was cut out from a region other than the center seal portion of the heat-shrinkable cylindrical label and having a printed layer and a heat-shrinkable substrate.
After heating, 1 ml of the headspace gas in the flask was collected using a gas tight syringe, and this was collected from a gas chromatograph equipped with a hydrogen flame ion detector (trade name “GC-2014” manufactured by Shimadzu Corporation). Carrier gas: Nitrogen gas, filler: appropriately selected according to the solvent to be measured, flow rate: 20-40 ml / min, column temperature: 70-80 ° C., detector: 70-150 ° C., inlet: 70- 150 ° C.), the amount of each solvent was measured from a calibration curve prepared in advance, and the measured value was converted per square meter.
For the calibration curve, 1 microliter of the solvent to be measured was collected with a microsyringe, placed in a 500 ml Erlenmeyer flask at room temperature and normal pressure, and the flask was sealed with a silicone rubber stopper. After heating for 30 minutes at 0 ° C., 1 ml of the headspace gas in the flask is collected using a gas tight syringe, and this is analyzed using the same gas chromatograph as described above. 2 microliters of the above solvent was collected and similarly analyzed using a gas chromatograph.

[Example 1]
Using a gravure printing machine (conveying speed 200 m / min) on almost the entire back surface of the polystyrene film (the entire back surface excluding the portion that becomes the center seal portion), 6 g of color ink having the solvent composition shown in Table 1 per square meter. The design layer was formed by gravure printing and drying with hot air of 50 ° C. Further, a white ink having a solvent composition shown in Table 1 was gravure-printed at 8 g per square meter on the back surface of the design layer, and dried with hot air at 50 ° C. to form a background layer.
Thus, the heat-shrinkable base material which has a printing layer (design layer + background layer) was produced.
By rolling the heat-shrinkable base material having the printed layer so that the heat-shrink direction is the circumferential direction and bonding both end portions, a cylindrical label continuous body including a heat-shrinkable cylindrical label was produced. The cylindrical label continuous body was flattened, wound into a roll, and allowed to stand for 48 hours in an environment of 23 ° C. and 60 ± 5% RH.
A part of the cylindrical label continuous body after curing was cut out, and the type and content of the solvent contained therein were measured. The results are shown in Table 2.
Moreover, a part of the cylindrical label continuous body after curing was cut out, and the yield strength was measured. The results are shown in Table 2.

The cylindrical label continuum after curing is mounted on a known labeler (trade name “LSA2000”, manufactured by Fujistec Co., Ltd.), and a heat-shrinkable cylindrical label is placed on a commercially available 500 ml polyethylene terephthalate square container. 100 square containers with a cylindrical label were continuously produced by external fitting and heat shrinking.
This labeler is as described above, and pulls out the cylindrical label continuous body from the roll of the loaded cylindrical label continuous body and performs a re-folding process to make the cylindrical label continuous body flat again. After cutting with a guillotine cutter to obtain a flat heat-shrinkable cylindrical label with a length suitable for half-shrink, open it through a mandrel, and open the heat-shrinkable cylindrical label into a square container This is an apparatus that can be continuously fitted into a rectangular container with a cylindrical label by being externally fitted and heated (production speed: 100 / min).
100 square containers with a cylindrical label produced by a labeler were inspected as to whether the design of the heat-shrinkable cylindrical label was accurately positioned in front of one panel of the square container. As a result, as shown in Table 2, two were determined to be defective.

[Examples 2 to 4 and Comparative Examples 1 to 3]
Except having changed white ink, the cylindrical label continuous body was produced similarly to Example 1, the solvent content and the yield point intensity | strength were measured, and the mounting test with respect to a square container was done. The results are shown in Table 2.

  As is apparent from Table 2, the heat-shrinkable cylindrical labels of Examples 1 to 4 having a low content of low-volatile solvent are smaller than the heat-shrinkable cylindrical labels of Comparative Examples 1 to 3 having a large content. It can be seen that the defect rate is low and the wearability is excellent. Further, from the comparison between Examples 1 to 3 and Comparative Example 3, it can be seen that the content of the highly volatile solvent hardly affects the wearability, and the low volatile solvent affects the wearability. . Further, it can be seen from the comparison between Example 1 and Example 2 that the medium volatile solvent also affects the deterioration of the wearability.

DESCRIPTION OF SYMBOLS 1 Heat-shrinkable cylindrical label 1L Cylindrical label continuous body 2 Heat-shrinkable base material 3 Printing layer 5 Square container 52a Panel surface 52b Corner surface 61,62,63,64 1st, 2nd, 3rd and 4th Fold 10 Square container with cylindrical label

Claims (6)

It has a heat-shrinkable base material containing a polystyrene-based resin and a printed layer, and the content of the solvent with a specific evaporation rate of less than 50 is 5 mg / m ² or less, and the content of the solvent with a specific evaporation rate of 50 to 100 is 10 mg. A preparatory step of preparing a cylindrical label continuous body including a heat-shrinkable cylindrical label that is / m ² or less, folded in a flat shape by facing the first and second folds,
The manufacturing method of the square container with a cylindrical label which has the external fitting process which opens a flat heat-shrinkable cylindrical label and externally fits it to the square container which has four panel surfaces.
However, the content of the solvent is obtained by converting the amount of the solvent volatilized by heating the heat-shrinkable cylindrical label at 80 ° C. for 30 minutes per unit area. The manufacturing method of the square container with a cylindrical label of Claim 1 whose content of the solvent of the specific evaporation rate 50-100 of the said heat-shrinkable cylindrical label exceeds zero and is 10 mg / m < ² > or less. The manufacturing method of the square container with a cylindrical label of Claim 1 or 2 whose content of the solvent of less than 50 of the specific evaporation rate of the said heat-shrinkable cylindrical label exceeds zero and is 5 mg / m < ² > or less.   Prior to the external fitting step, a cylindrical label continuous body or a heat-shrinkable cylindrical label folded in a flat shape by the first and second folds is changed into a third and different folds from the first and second folds. The manufacturing method of the square container with a cylindrical label as described in any one of Claims 1 thru | or 3 which further has the re-folding process which refolds flatly in a 4th crease | fold.   In the outer fitting step, the heat-shrinkable cylindrical label is formed so that the first, second, third and fourth folds correspond to the corner surfaces between the four panel surfaces of the rectangular container. The manufacturing method of the square container with a cylindrical label of Claim 4 externally fitted to the said square container.   The manufacturing method of the square container with a cylindrical label as described in any one of Claims 1 thru | or 5 whose yield point intensity | strength of the said heat-shrinkable cylindrical label is larger than the yield point intensity | strength of the said heat-shrinkable base material. .

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