JP2012230268A - Roll shrink label and container produced by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roll shrink label capable of peeling off an adhesion object by hand without a paste residue and peeling off an adhesion object from a substrate with a hot alkali aqueous solution easily and without a paste residue.SOLUTION: There is provided a roll shrink label wound around the outer periphery of a container, which is composed of a base film, a first adhesive layer consisting of a first hot-melt binder which is formed at an end of the container and fixes the base film and a second adhesive layer consisting of a second hot-melt binder which is formed at the other end of the container and fixes the base films together. The first adhesive layer may be dispersed or dissolved in a 1.5 wt.% of NaOH aqueous solution at 90°C and the second hot-melt binder contains a polyethylene wax having a softening point of 110°C or more and 140°C or less.

Description

  The present invention relates to a roll shrink label, a labeled container using the same, and a manufacturing method thereof. The roll shrink label of the present invention is preferably used for glass bottles and PET (polyethylene terephthalate) bottles used in soft drinks, seasonings, detergents, shampoos, edible oils, cosmetics, pharmaceuticals and the like.

  In recent years, the amount of PET bottles used for beverages has increased along with the amount of PET bottles produced. The used PET bottles are discharged as garbage, but a recycling system has been established by the Recycled Resource Utilization Promotion Law so that the amount of the garbage is not increased as much as possible and can be recycled as resources. In recycling PET bottles, the PET bottles collected after use are cut into 8mm square pellets, soaked in hot alkali (85-90 ° C 1.5% NaOH) aqueous solution for about 15 minutes, peeled off the label, washed with water and dried -Labels are removed by wind selection and PET pellets are recycled.

  For this reason, PET bottle labels include stretch labels, shrink labels, roll labels using alkali-dispersed hot-melt adhesives (Patent Documents 1 and 2), and the like. Stretch labels use the principle of rubber bands that return to their original state when stretched and released. In other words, the body-shaped label is stretched and placed on the PET bottle to release it, and the label is returned to its original position and wrapped for use. However, stretch labels cannot be used for uneven PET bottles (atypical bottles) that have a small restoring force of the labels and emphasize design. The shrink label covers a PET bottle while cutting a cylindrical label with a labeler, and shrinks it with the heat of a heater or steam, thereby closely attaching the film to the container. However, this method has a problem in that the cost is high because the label needs to be processed into a cylindrical shape in advance. Moreover, in order to make it easy to cover a cylindrical label on a bottle, a certain amount of label thickness is required, and there is a problem of cost. Furthermore, when the temperature is 30 ° C. or higher, the shrink label shrinks and wrinkles are generated and cannot be covered well, and it is necessary to adjust the humidity during storage of the label. On the other hand, a roll label using an alkali-dispersed hot melt pressure-sensitive adhesive has a problem that it cannot be used for uneven PET bottles (atypical bottles) that emphasize design.

  Patent Document 3 proposes to use a UV (Ultraviolet) curable hot melt adhesive / or UV adhesive for the roll shrink label, but it is difficult to control the UV irradiation amount of the UV curable adhesive, It did not conform to the voluntary regulations of the PET bottle recycling promotion council because it was not dispersed in alkali. In addition, problems such as a more complicated structure of the labeler and an increase in the price of the labeler have occurred. Furthermore, UV curable hot-melt adhesives are irritating to the skin and attach to the skin of the worker, or because of hot melt, if the heated steam adheres to the skin, the sensitive person causes an allergic reaction. There was a problem with safety.

  When using a hot melt adhesive, the shrink label does not shrink even if the hot melt adhesive or hot melt head heated during the application of the hot melt adhesive contacts the shrink label (that is, the substrate film). After being wound around the bottle, it is necessary that the shrink label is sufficiently shrunk when passing through the shrink tunnel, and the bonded portion of the hot melt adhesive is not displaced. However, the conventional hot-melt pressure-sensitive adhesive has good coating suitability, and there has been no hot-melt pressure-sensitive adhesive in which the bonded portion does not shift even through a shrink tunnel.

JP 2005-220244 A Japanese Patent No. 4278704 JP 2008-145498 A

  An object of the present invention is to provide a container with a roll shrink label in which there is no redeposition of the label or hot melt adhesive to the PET bottle after the label is peeled off.

  Furthermore, an object of the present invention is to provide a roll shrink label excellent in recyclability, which can peel off the adhesive without leaving adhesive residue, and can easily peel off the adhesive from the substrate with a hot alkaline aqueous solution without adhesive residue. Is to provide.

  In order to recycle PET bottles, the PET Bottle Recycling Promotion Council has been working with related organizations and ministries to develop various laws and guidelines for PET bottles. For PET bottle labels, we have created “independent design guidelines for designated PET bottles” and are self-regulating. In this voluntary regulation, either a stretch label or shrink label, or a film or paper label such as an OPP (stretched polypropylene) film, PE (polyethylene) film, or PET film, and either hot water peeling or hot alkali peeling The label had to be peeled off.

  The method for peeling the label from the PET bottle is based on the “designated PET bottle self-regulation guidelines” issued by the PET Bottle Recycling Promotion Council. That is, in the hot alkali peeling test, a pellet made by cutting a bottle with a label, printing, etc., was immersed in a 1.5% NaOH aqueous solution at 90 ° C. at a pellet concentration of 10% (weight ratio) and slowly slowed for 15 minutes. Stir. Subsequently, it filters with a filter and visually observes a pellet. When the label peels off and printing ink, adhesive, etc. do not remain in the bottle, it is judged that there is suitability for thermal alkali peeling (recycling).

  The present invention is a hot melt pressure-sensitive adhesive suitable for PET bottle paper and OPP trunk labels suitable for “independent design guidelines for designated PET bottles” issued by the PET Bottle Recycling Promotion Council, such as soft drinks and seasonings. A roll shrink label that uses an agent, and the label does not peel off even if it is placed in water when cooling it when using the label. However, if the bottle is pelletized and immersed in a hot alkaline solution after collection, the label can be easily removed from the PET bottle. A roll shrink label that peels off and does not adhere to a PET bottle again and can be used for an uneven PET bottle (atypical bottle) is provided.

  Even if hot melt adhesive is applied directly to the shrink label substrate, the substrate does not shrink, and after being wound around the container, the label is properly shrunk when passed through the shrink tunnel. Further, a roll shrink label that is fixed to the surface and does not cause displacement or peeling on an adhesive surface or the like is provided.

  Moreover, this invention provides the container with a label which uses the roll shrink label which has the said characteristic further.

The present invention relates to the following contents.
[1] A roll shrink label that is wound around the outer periphery of a container and mounted.
Base film,
A first adhesive layer made of a first hot melt adhesive, which is formed at one end of the substrate film and fixes the substrate film and the container; and
A second adhesive layer made of a second hot-melt adhesive, which is formed on the other end of the base film and fixes the base films,
The first adhesive layer can be dispersed or dissolved in a 1.5 wt% NaOH aqueous solution at 90 ° C., and the second hot melt adhesive contains a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower. A roll shrink label.

[2] The roll shrink label as described above, wherein the second hot-melt pressure-sensitive adhesive comprises a thermoplastic elastomer, a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower, a tackifier, and a synthetic oil.

[3] The second hot melt pressure-sensitive adhesive is 100% by weight in total of the pressure-sensitive adhesive,
5 to 30% by weight of a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower,
10-20% by weight of thermoplastic elastomer,
Tackifier 25 to 40% by weight, and
The roll shrink label as described above, comprising 25 to 40% by weight of synthetic oil.

[4] The roll shrink label as described above, wherein the base film is a MD direction uniaxially stretched film.

[5] A labeled container in which the roll shrink label described above is mounted on the outer periphery of the container.

[6] A first pressure-sensitive adhesive layer made of a first hot-melt pressure-sensitive adhesive that fixes the base film and the container is formed on one end of the base film,
A step (I) of preparing a roll shrink label by forming a second adhesive layer made of a second hot-melt adhesive to fix the base films to the other end of the base film;
The step (II) in which the label obtained in the step (I) is wound around the outer periphery of the container, the label and the container are fixed by the first adhesive layer, and the labels are fixed by the second adhesive layer, and
A method for producing a labeled container, comprising the step (III) of shrinking the label by heating,
The first adhesive layer can be dispersed or dissolved in a 1.5 wt% NaOH aqueous solution at 90 ° C., and the second hot melt adhesive contains a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower. A method for producing a labeled container, comprising:

  According to the present invention, after the roll shrink label is peeled off, it does not reattach to the container.

  In addition, the roll shrink label of the present invention can be used for uneven (atypical) bottles, and the label does not peel off when the container is used. By simply stirring in a 1.5% NaOH aqueous solution at 15 ° C. for 15 minutes, the label peels off from the PET bottle, and the label or hot melt adhesive does not reattach to the PET bottle.

  Furthermore, the roll-shrink label of the present invention is a requirement to peel off the label with hot alkaline water in the “Self-regulation Guidelines for Designated PET Bottles” issued by the PET Bottle Recycling Promotion Council, and to be able to peel off without adhesive residue by manual peeling. Since it satisfy | fills, it can utilize preferably as a label for PET bottles.

  Furthermore, when the roll shrink label is peeled off from the PET bottle, no hot melt adhesive remains on the PET bottle.

  Hereinafter, the roll shrink label of the present invention will be described in more detail.

  First, the roll shrink label of the present invention is a roll shrink label that is wound around the outer periphery of a container, and is a base film and an alkali dispersion type first hot melt provided on the surface of the base film. A first pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive and a second pressure-sensitive adhesive layer composed of a second hot-melt pressure-sensitive adhesive that does not disperse and dissolve in a 1.5 wt% NaOH aqueous solution at 90 ° C. .

  Examples of the base film of the roll shrink label include a stretched polyester film, a stretched polystyrene film, a stretched polyolefin film, a polylactic acid film, a foamed polyolefin film, a stretched polyester-polystyrene coextruded film, and a foamed polystyrene system. A film is mentioned. Or the laminated film of a nonwoven fabric and the said film may be sufficient. The stretched film may be uniaxially stretched or biaxially stretched, and in the case of a uniaxially stretched film, it may be longitudinally uniaxially stretched or laterally uniaxially stretched. However, the shrink uniaxially stretched film is suitable for the shrink label in which the shrink label is formed in a cylindrical shape and attached to the container and then subjected to heat shrinkage treatment, whereas the roll shrink label of the present invention is used as the shrink label. Even if it is a case, it is not limited to a laterally uniaxially stretched film, Any of laterally uniaxially stretched, longitudinally uniaxially stretched, and a biaxially stretched film can be used conveniently.

  In the present invention, it is preferable to use an MD (Machine Direction) direction uniaxially stretched film as the base film.

It is preferable that the thermal contraction rate of the base film with respect to the stretching direction is 5 to 85% so that the label of the present invention has an effect as a roll shrink label. In addition, the heat shrinkage rate in this invention is a heat shrinkage rate by 100 degreeC hot water, Comprising: The heat shrinkage rate of an extending | stretching direction shall follow a following formula. Therefore, in the case of a longitudinally uniaxially stretched film, since the shrinking direction is the film flow direction, the thermal shrinkage rate in the flow direction is 5 to 85%, and in the case of a laterally uniaxially stretched film, the film shrinks in the film width direction. The heat shrinkage ratio in the film width direction is 5 to 85%. In the case of a biaxially stretched film, the thermal shrinkage rate is preferably within the above range with respect to any stretching method.
Thermal contraction rate (%) = (dimension before heating−dimension after heating) / (dimension before heating) × 100
The thickness of the base film layer is not particularly limited, but is appropriately selected within a range not impairing heat resistance, rigidity, mechanical suitability, appearance, etc., and is preferably about 10 to 50 μm. The roll shrink label can be used even if the thickness of the label is thin. Therefore, in consideration of economy, the thickness is particularly preferably 10 to 30 μm.

  Furthermore, various additives such as a lubricant, a filler, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a flame retardant, and a colorant are added to the base film as necessary. Also good. Further, the surface of the base film layer may be subjected to conventional surface treatment such as corona discharge treatment, plasma treatment, flame treatment, acid treatment, etc. in order to improve printability.

  The base film is not limited to a single layer of the film, and may be a laminated film of two or more types of films. Further, a vapor deposition film of silicon oxide, aluminum oxide, aluminum, or the like is provided on these films. It may be provided. As thickness of a laminated film, what is formed in about 10-300 micrometers is preferable.

  The containers used in the present invention include glass containers such as glass bottles used for soft drinks, seasonings, detergents, shampoos, edible oils, cosmetics, pharmaceuticals, and plastic containers such as PET (polyethylene terephthalate) bottles. Examples include paper containers. The label of the present invention is preferably used for PET bottle containers from the viewpoint of bottle recycling, but can also be used for other plastic containers, glass containers, and paper.

  Moreover, the 1st hot-melt adhesive in this invention will not be specifically limited if it disperse | distributes or melt | dissolves in 1.5 weight% NaOH aqueous solution of 90 degreeC.

  Specifically, the first hot melt pressure-sensitive adhesive is a hot melt pressure-sensitive adhesive for PET bottle trunk-wrap labels. Examples of hot melt pressure-sensitive adhesives for PET bottle trunk-wrapped labels include Toyo Adre Co., Ltd. Label Mel BL-8603 series.

  The 2nd hot-melt adhesive in this invention contains the polyethylene wax whose softening point is 110 degreeC or more and 140 degrees C or less. When polyethylene wax with a softening point of 110 ° C or higher and 140 ° C or lower is not included, the adhesive strength of the hot melt pressure-sensitive adhesive at the shrinking temperature is reduced, and the shrinkability (the container before shrinking with the label attached to the PET bottle is set to 90 ° C) It is immersed in a temperature-controlled hot water bath for 3 seconds and there is no evaluation of whether the label is displaced or peeled off, and the adhesive surface is displaced or peeled off.

  The second hot-melt pressure-sensitive adhesive in the present invention preferably contains a thermoplastic elastomer, a tackifier and a synthetic oil.

Examples of the thermoplastic elastomer in the present invention include styrenic polymers. The styrenic thermoplastic elastomer generally has a polystyrene block and a rubber intermediate block, and the polystyrene portion forms a physical crosslink (domain) to become a bridging point, and the intermediate rubber block gives rubber elasticity to the product. The intermediate soft segment includes polybutadiene (B), polyisoprene (I), and polyolefin elastomer (ethylene propylene, EP). Depending on the arrangement of the hard segment with polystyrene (S), linear (linear type) And radial (radical type).
Among the preferable styrene elastomers described above, in the present invention, styrene / butadiene block copolymer (SB, diblock), (SBSS, triblock), styrene / isoprene block copolymer (S- I, diblock), (S-I-S, triblock), and styrene / butadiene-isoprene block copolymer (SB-I, diblock), (SB / IB, triblock) And hydrogenated products of these block copolymers, for example, hydrogenated styrene / butadiene / styrene block copolymers (SBS), hydrogenated styrene / isoprene / styrene block copolymers (SEPS), Acid-modified styrenic elastomers as described above, and in addition to styrene in the styrene block, styrene and α-methylstyrene, etc. A copolymer of the aromatic vinyl compound is also exemplified. More preferred is a styrene-ethylene-butylene-styrene block polymer (SEBS) from the viewpoint of thermal stability (difficult to thermally decompose).

  It is preferable that the melt viscosity of the thermoplastic elastomer in the present invention (the measured viscosity with a B-type viscometer at 25 ° C. of a 25 wt% thermoplastic elastomer concentration toluene solution) is 1 Pa · s or more and 10 Pa · s or less. When the melt viscosity of the thermoplastic elastomer is less than 1 Pa · s, the adhesive strength of the hot melt adhesive at the shrink temperature is low, and the shrinkability (the temperature of the container before shrink with the label attached to the PET bottle is adjusted to 90 ° C) Soaked in a hot water bath for 3 seconds, there is no evaluation of whether the label is displaced or peeled off), and the adhesive surface is displaced or peeled off. When the viscosity is higher than 10 Pa · s, the hot melt pressure-sensitive adhesive is rubbed by the slit coater or stringing occurs when the hot melt pressure-sensitive adhesive is applied.

  The thermoplastic elastomer in the present invention is used to increase the cohesive strength of the hot melt pressure-sensitive adhesive, and is preferably 10% by weight or more and 20% by weight or less in a total of 100% by weight of the pressure-sensitive adhesive. If it is less than 10% by weight, the cohesive strength is small, the adhesive strength of the hot melt adhesive at the shrink temperature is low, and the shrinkability (the container before shrinking with the label attached to the PET bottle is placed in a hot water bath adjusted to 90 ° C. It is soaked for 3 seconds, there is no evaluation of whether the label is displaced or peeled off, and the adhesive surface is displaced or peeled off. When the content is more than 20% by weight, the hot melt adhesive is rubbed by the slit coater or stringing occurs when the hot melt adhesive is applied.

  Examples of the tackifier used in the present invention include phenol resins, modified phenol resins, terpene phenol resins, xylene phenol resins, xylene resins, cyclopentadiene-phenol resins, aliphatic, alicyclic, and aromatic petroleum. Resins, hydrogenated aliphatic, alicyclic, aromatic and other petroleum resins, phenol-modified petroleum resins, rosin ester resins, acid-modified rosin resins, hydrogenated rosin resins, hydrogenated rosins Examples thereof include ester resins, low molecular weight polystyrene resins, terpene resins, and hydrogenated terpene resins. Tackifying resins may be used alone or in combination of two or more.

  The tackifier used in the present invention is used to improve the adhesion between the shrink labels or between the shrink label and the printing surface of the shrink label. The tackifier used in the present invention is preferably 25% by weight or more and 40% by weight or less in a total of 100% by weight of the second hot melt adhesive. If it is less than 25% by weight, the adhesiveness is poor and the shrinkability (evaluates whether the label is displaced or peeled off by immersing the container before shrinking the label on the PET bottle for 3 seconds in a hot water bath adjusted to 90 ° C). And the adhesive surface peels off. If it exceeds 40% by weight, the cohesive strength of the adhesive is lost, and similarly shrinkability is lost.

  The synthetic oil in the present invention is an oil generally used as a plasticizer such as rubber or thermoplastic elastomer, a process oil produced in so-called petroleum refining and the like, paraffinic process oil, naphthenic process oil, aromatic It is broadly classified as a family process oil. Process oil is a mixture of aromatic rings, naphthene rings, and paraffin chains. Generally, the aromatic carbon in the total carbon is 30 wt% or more, and the aromatic oil is 35 to 45 wt% in the naphthenic ring carbon. Naphthenics and those with 50% by weight or more of paraffin chain carbon are classified as paraffinic. Paraffinic crude oil is separated into paraffinic oil and aromatic oil by distillation, hydrogenation reforming, solvent extraction, and solvent dewaxing. Naphthenic crude oil is also separated into naphthenic and aromatic oils by distillation and solvent extraction. In the present invention, the synthetic oil is preferably a naphthenic oil or a paraffinic oil from the viewpoint of adhesive residue when peeling off by hand. There are various commercial products under the trade names such as “Diana Fresia” and “Diana Process Oil” from Idemitsu Kosan Co., Ltd., and “Fukor New Flex” and “Fukor Flex” from Fuji Kosan Co., Ltd. Grades are commercially available. Synthetic oil is used in the present invention so as not to lower the adhesive strength at low temperatures.

  The synthetic oil in the present invention is preferably used in a proportion of 25% by weight to 40% by weight in the total 100% by weight of the second hot melt adhesive.

  The polyethylene wax having a softening point of 110 ° C. or more and 140 ° C. or less in the present invention is used for improving shrinkability. When polyethylene wax with a softening point of less than 110 ° C is used, the adhesive strength of the hot melt adhesive at the shrink temperature is reduced, and shrink suitability (the temperature of the container before shrink with the label attached to the PET bottle is adjusted to 90 ° C) Soaked in a hot water bath for 3 seconds, there is no evaluation of whether the label is displaced or peeled off, and the adhesive surface is displaced or peeled off. When a polyethylene wax having a softening point higher than 140 ° C. is used, the coating suitability is poor and the coating cannot be performed or rubbed. Preferably, the polyethylene wax having a softening point of 110 ° C. or more and 140 ° C. or less is 5% by weight or more and 30% by weight or less, more preferably 10% by weight or more and 20% by weight or less in the total 100% by weight of the second hot melt adhesive. The following is desirable. If the amount is less than 5% by weight, the shrinkability is poor. If the amount is more than 30% by weight, the adhesive strength of the hot melt adhesive at the shrink temperature decreases, and shrinkability (90% of the container before shrinking with the label attached to the PET bottle) It is soaked in a hot water bath adjusted to 0 ° C. for 3 seconds, and there is no evaluation of whether the label is displaced or peeled off, and the adhesive surface may be displaced or peeled off.

  There are three typical methods for synthesizing polyethylene. (1) High pressure method: The most representative is ICI method, and other BASF, du Pont method, Union Carbide method, etc. (2) Medium pressure method: Philips method, Standard (Indiana) method, etc. (3) Low pressure method: For example, the Ziegler method. Polyethylene waxes are commercially available under the trade names of “POLYWAX” from Baker Petrolite, “Neowax” from Yashara Chemical Co., Ltd., and “AC polyethylene” from Allied Signal.

  The measurement of the softening point of the polyethylene wax was performed in accordance with JIS K-2207 (petroleum asphalt) 6.4 softening point test method (ring and ball method).

  A second hot melt pressure-sensitive adhesive is prepared by mixing polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower, a thermoplastic elastomer, a tackifier, and a synthetic oil. For example, the mixing order is as follows. First, synthetic oil and thermoplastic elastomer are added and dissolved by heating, then a tackifier is added and completely dissolved, and finally the polyethylene wax having a remaining softening point of 110 ° C. or higher and 140 ° C. or lower. May be input. The tool used is heated, and the stirrer is preferably 200 to 500 rpm with a propeller-type stirring blade.

  When the total amount of the second hot-melt pressure-sensitive adhesive is 100, the blending ratio (% by weight) of each component is polyethylene wax of 110 ° C. or higher and 140 ° C. or lower: thermoplastic elastomer: tackifier: synthetic oil = 5-30: 10-20: 25-40: 25-40. Within this range, the cohesive force is maintained, the adhesiveness is good, and the roll shrink label is not peeled off when thermally contracted.

  The mechanism by which the hot melt pressure-sensitive adhesive used in the container of the present invention can be used for a roll shrink label will be described. When a hot melt adhesive is used for a roll shrink label, it cannot be applied at a high temperature because the shrink label shrinks due to the heat of the hot melt adhesive and the head when the hot melt adhesive is applied. It is necessary to apply hot melt adhesive and head temperature at 130 ° C or less (the actual head temperature is in contact with the atmosphere, so it is cooled to about 110 ° C, and the shrink label is in contact with the head at 110 ° C for a short time. Will not shrink). However, considering the coating property at a high speed (700 bpm) of the hot melt coating machine, the viscosity of the hot melt adhesive at 110 ° C. needs to be 20 Pa · s or less. On the other hand, in consideration of shrinkability when the manufactured roll shrink label is attached to a container, the viscosity at 90 ° C. is required to be 1,000 Pa · s or more. A general hot-melt pressure-sensitive adhesive has a low viscosity at a high temperature, and thus such a hot-melt pressure-sensitive adhesive cannot be obtained. That is, the viscosity of the second hot melt pressure-sensitive adhesive needs to be 1,000 Pa · s or more at 90 ° C. and 20 Pa · s or less at 110 ° C., and the viscosity curve at 90 ° C. and 110 ° C. may change greatly. is necessary.

  In the present invention, by using a polyethylene wax having a softening point of 110 ° C. or more and 140 ° C. or less, the viscosity of the second hot-melt pressure-sensitive adhesive is 1,000 Pa · s or more at 90 ° C. and 20 Pa · s or less at 110 ° C. Was made.

  The obtained roll shrink label is wound around the outer periphery of the container, the label and the container are adhered by the first adhesive layer made of the first hot melt adhesive, and further the second made of the second hot melt adhesive. The labels are fixed by the adhesive layer. Next, the shrink process is started.

  Next, the manufacturing method of a container with a roll shrink label will be described more specifically.

  First, a first adhesive layer made of a first hot melt adhesive is formed on one end of a roll shrink label, and a second adhesive layer made of a second hot melt adhesive is formed on the other end, with an adhesive layer A roll shrink label. As a method for forming each adhesive layer, an adhesive may be directly applied to form an adhesive layer, or an adhesive layer may be transferred and indirectly applied.

  Examples of the direct coating method include slit coating, curtain spray, spiral spray, dot or bead coating, and slit coating is preferable.

  In the case of contact coating, when slit coating is used, the temperature of the coating head is preferably 90 ° C. or higher and 120 ° C. or lower. If it is in said temperature range, even if it is higher than the shrink temperature of a roll shrink label, since the time for which a shrink label is heated is short, it can coat without shrinking. As for the temperature of a melting tank and a hose, 120 to 150 degreeC is desirable. If it is lower than this, the viscosity of the hot-melt pressure-sensitive adhesive may be high and the coating suitability may be impaired.

  In the curtain spray, spiral spray, dot or bead method, since there is a distance from the nozzle to the base film, each adhesive will cool down before reaching the base film, so the roll shrink label will shrink before mounting. Can be prevented.

  Examples of the method of indirectly applying include a method using a roll. As a test method using a roll, for example, after applying a hot melt pressure-sensitive adhesive on a release paper using a hand applicator, the coated product is cut to a required size and transferred to a base film. It corresponds to the method. According to this method, there is no possibility that the roll shrink label shrinks due to the temperature of the adhesive during coating.

  The width of the first adhesive layer formed at one end of the roll shrink label is preferably 2 mm or more, more preferably 5 mm or more from the viewpoint of temporary fixing. The width of the second adhesive layer formed on the other end of the roll shrink label is preferably 3 mm or more, more preferably 10 mm or more, and further preferably 20 mm or more. When the width of the second adhesive layer is 3 mm or more, when the roll shrink label is heated with steam or the like, the strength of the adhesive layer is insufficient and the label is not peeled off or displaced. The “adhesive layer width” here is the length of the adhesive layer in the label winding direction.

  Next, the roll shrink label with the adhesive layer is wound around the container, the label and the container are fixed by the first adhesive layer, and the labels are fixed by the second adhesive layer.

  Next, the roll shrink label wound around the container is shrunk with steam or hot water, and fixed around the container. The shrink temperature is preferably 80 to 95 ° C.

  When the roll shrink label is shrunk, the first hot melt pressure-sensitive adhesive used when the container and the label are adhered is partially peeled off from the bottle and adhered, even when the container is used or at 90 ° C. There is no problem with peeling with a 5 wt% NaOH aqueous solution. This is because, once shrinking, the label is fixed on the container mainly by the shrinkage stress of the film.

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

  In the examples, “parts” simply means “parts by weight” and “%” means “% by weight”. “Wt%” means “wt%”.

  The components used in the first and second hot melt adhesives are as follows.

(First hot melt adhesive)
Label Melt BL-8603C (manufactured by Toyo Adre Co., Ltd.)
Viscosity: 100 ° C 10.0 Pa · s
110 ° C 5.3 Pa · s
120 ° C 3.2 Pa · s
Alkali dispersibility: yes

(Second hot-melt pressure-sensitive adhesive trial production method)
Thermoplastic elastomer Kraton G1650 (manufactured by Kraton Polymer) (hereinafter abbreviated as “G1650”)
Styrene-ethylene-butylene-styrene block polymer (SEBS)
Diblock amount: 0%
Melt viscosity ^{* 1} : 8 Pa · s
Clayton G1652 (manufactured by Clayton Polymer) (hereinafter abbreviated as “G1652”)
Styrene-ethylene-butylene-styrene block polymer (SEBS)
Diblock amount: 0%
Melt viscosity ^{* 1} ; 1.350 Pa · s
The melt viscosity ^{* 1} is a melt viscosity at 25 ° C. of a toluene solution having a thermoplastic elastomer concentration of 25% by weight. The melt viscosity was measured using a B-type viscometer RB80L (manufactured by Toki Sangyo Co., Ltd.). 3 was carried out at a suitable rotational speed.

Tackifier, Haritac F (manufactured by Harima Chemicals)
Hydrogenated rosin Acid value: 175 mgKOH / g
Softening point: 72 ° C
・ YS Polystar T30 (manufactured by Yasuhara Chemical Co., Ltd.) (hereinafter abbreviated as “T30”)
Terpene phenol resin Softening point: 30 ° C

Synthetic oil Diana Fresia N-90 (manufactured by Idemitsu Kosan Co., Ltd.) (hereinafter abbreviated as “N90”)
Paraffin process oil

Polyethylene wax / polywax 850 having a softening point of 110 ° C. or higher and 140 ° C. or lower (manufactured by Baker Petrolite)
Molecular weight: 850
Softening point: 107 ° C
Dispersity: 1.08
Needle penetration: 1.0
・ Polywax 1000 (manufactured by Baker Petrolite)
Molecular weight: 1000
Softening point: 117 ° C
Dispersity: 1.08
Needle penetration: 1.0
・ Polywax 2000 (manufactured by Baker Petrolite)
Molecular weight: 2000
Softening point: 128 ° C
Dispersity: 1.10
Needle penetration: 0.5
・ Polywax 3000 (Baker Petrolite)
Molecular weight: 3000
Softening point: 130 ° C
Dispersity: 1.10
Needle penetration: 0.5
・ Excellex 40800 (Mitsui Chemicals)
Molecular weight: 4000
Softening point: 135 ° C
Dispersity: 1.20
Needle penetration: 1.0
<Method for producing second hot melt pressure-sensitive adhesive>
(Production Example 1)
In a stainless beaker equipped with a stirrer, 35 parts by weight of synthetic oil: Diana Fresia N90, 20 parts by weight of thermoplastic elastomer: Kraton G1652 and 5 parts by weight of tackifier: YS Polyster T30 were charged and melted by heating. . Heating was performed with care so that the contents would not be below 130 ° C and above 150 ° C. After melting, stirring is performed to obtain a uniform molten solution, and while maintaining the temperature below 150 ° C. and continuing stirring, 35 parts by weight of a tackifier: Haritac F is gradually added to the melt, and after completion of the addition, Polyethylene wax: 5 parts by weight of Polywax 2000 was added to form a molten homogeneous mixture, and cooled to obtain a second hot melt pressure-sensitive adhesive composition.

(Production Examples 2 to 7)
As synthetic oil, thermoplastic elastomer, tackifier, and polyethylene wax, the components shown in Table 1 below were added, and the second hot melt pressure-sensitive adhesives of Production Examples 2 to 7 were produced in the same manner as Production Example 1. did.

<Measurement method of viscosity>
About the obtained 2nd hot melt adhesive, the viscosity measurement was performed using the plate-type rheometer. The measurement method and measurement conditions are as follows. The measurement results are shown in Table 1.
・ Measuring device: Dynamic viscosity viscoelasticity measuring device Rheosol-G3000 (manufactured by UBM Co., Ltd. ・ Measurement mode: temperature dependence ・ Chuck: parallel plate ・ Waveform: sine wave ・ Parallel diameter: 19.99 mm
・ Cap: 1mm
-Temperature drop viscosity start temperature: 180 ° C Measurement end temperature: 30 ° C
・ Cooling rate: 3 ℃ / min ・ Rotation width: 2Hz, 3deg

<Production method of roll shrink label>
Using a hand applicator in which the first hot-melt pressure-sensitive adhesive and the second hot-melt pressure-sensitive adhesive prepared by the above method are heated to 150 ° C. on a release paper, the coating amount of the first hot-melt pressure-sensitive adhesive is 20 to 30 g / m ^2, the coating amount of the second hot melt adhesive did a coating such that 80 to 120 / m ^2. The coated product is cut to a required size, and the first hot-melt pressure-sensitive adhesive coated material prepared by the above method is transferred to one end of a base film having a width of 60 mm and a length of 250 mm shown below. 1 adhesive layer was provided. In the same manner, the second hot-melt pressure-sensitive adhesive coated material was transferred to the other opposite end and reciprocated once with a 2 kg roll to provide a second pressure-sensitive adhesive layer to produce a roll shrink label.

<Base film>
The base film used was a MD direction uniaxially stretched polyethylene terephthalate film (Toyobo Co., Ltd.) having a thickness of 20 μm.

(Examples 1-7)
<Method for producing labeled container>
The roll shrink label produced above was wound around a barrel of a cylindrical PET bottle having a circumference of 200 mm. At that time, the first adhesive layer is first adhered to the PET bottle, and then the roll shrink label is made a round, and the second adhesive layer is adhered to the roll shrink label. The second pressure-sensitive adhesive layer was not adhered to the PET bottle, but was adhered only to the roll shrink label, and the adhesive surface was sufficiently pressed with a finger to prepare a container. The prepared container was subjected to the following tests, and the results are shown in Table 1.

<Recyclability test>
The labeled container was pulverized to about 8 × 8 mm square to form a PET bottle pellet with a label attached. In a 1,000 ml round flask, 360 g of a 1.5 wt% sodium hydroxide aqueous solution and 40 g of the pellets were placed, and stirred at 250 rpm (stirring blade: propeller). After 15 minutes, the mixture was filtered with a filter, and the pellet was visually observed. If the hot melt did not adhere to the pellet: ◯, and if the hot melt adhered to the pellet: x.

<Shrink aptitude test>
The labeled container produced by the above method was placed in a hot water bath heated to 90 ° C., and the roll shrink label was shrunk and evaluated. When the roll shrink label was contracted and the first adhesive layer or the second adhesive layer was peeled off or deviated more than 2 mm, it was marked as x. The evaluation when the size of the deviation was 2 mm or less and the film was not peeled was evaluated as “◯”.

<Coating suitability and coating properties after stopping for 1 hour>
Using a melter series 3400 manufactured by Nordson, the second pressure-sensitive adhesive was applied to a shrink label (film thickness 20 μm manufactured by Toyobo Co., Ltd.) at a coating speed of 20 to 150 m / min by a slit coater method. In addition, the suitability was evaluated when the coating was stopped for one hour and then applied again. When the coated surface was rubbed or could not be coated, ×, when there was no problem: ◯.
Melter temperature setting: 140 ° C., hose setting temperature: 140 ° C., head setting temperature: 110 ° C.

(Comparative Examples 1-2)
A pressure-sensitive adhesive (second hot melt pressure-sensitive adhesive) for fixing the labels to each other was prepared in the same manner as in Production Example 1, and the viscosity was measured (Comparative Production Examples 1 and 2). ).

  Next, similarly to Example 1, a labeled container was prepared and each test was performed. The test results are shown in Table 2.

Claims (6)

A roll shrink label that is wound around the outer periphery of a container and attached.
Base film,
A first adhesive layer made of a first hot melt adhesive, which is formed at one end of the substrate film and fixes the substrate film and the container; and
A second adhesive layer made of a second hot-melt adhesive, which is formed on the other end of the base film and fixes the base films,
The first adhesive layer can be dispersed or dissolved in a 1.5 wt% NaOH aqueous solution at 90 ° C., and the second hot melt adhesive contains a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower. A roll shrink label.   The roll shrink label according to claim 1, wherein the second hot-melt pressure-sensitive adhesive includes a thermoplastic elastomer, a polyethylene wax having a softening point of 110 ° C or higher and 140 ° C or lower, a tackifier, and a synthetic oil. The second hot melt pressure-sensitive adhesive is a total of 100% by weight of the pressure-sensitive adhesive,
5 to 30% by weight of a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower,
10-20% by weight of thermoplastic elastomer,
Tackifier 25 to 40% by weight, and
The roll shrink label according to claim 2, comprising 25 to 40% by weight of synthetic oil.   The roll shrink label according to any one of claims 1 to 3, wherein the base film is a MD direction uniaxially stretched film.   A labeled container in which the roll shrink label according to any one of claims 1 to 4 is mounted on the outer periphery of the container. A first adhesive layer made of a first hot-melt adhesive is formed on one end of the base film to fix the base film and the container,
A step (I) of preparing a roll shrink label by forming a second adhesive layer made of a second hot-melt adhesive to fix the base films to the other end of the base film;
The step (II) in which the label obtained in the step (I) is wound around the outer periphery of the container, the label and the container are fixed by the first adhesive layer, and the labels are fixed by the second adhesive layer, and
A method for producing a labeled container, comprising the step (III) of shrinking the label by heating,
The first adhesive layer can be dispersed or dissolved in a 1.5 wt% NaOH aqueous solution at 90 ° C., and the second hot melt adhesive contains a polyethylene wax having a softening point of 110 ° C. or higher and 140 ° C. or lower. A method for producing a labeled container, comprising: