JP2002104349A - Mounting method of heat-sensitive adhesive label and PET bottle mounted with heat-sensitive adhesive label - Google Patents

Abstract

(57) [Summary] A heat-sensitive adhesive label once attached to a PET bottle is hardly detached, and when the heat-sensitive adhesive label is forcibly removed from the PET bottle, the heat-sensitive adhesive label is adhered to the PET bottle. Provided is a method for mounting a heat-sensitive adhesive label on which a layer is unlikely to remain and a PET bottle to which a heat-sensitive adhesive label is mounted. Kind Code: A1 A label substrate formed of biaxially stretched polypropylene, and an adhesive to a label substrate rather than an adhesive strength to a PET bottle B, which is laminated via a printing layer on inner surfaces of both ends of the label substrate. After performing a corona discharge treatment on the outer surface of a heat-sensitive adhesive label 1 having an adhesive layer formed of an ethylene-vinyl acetate copolymer having a high strength, the heat-sensitive adhesive label having an outer surface subjected to a corona discharge treatment The adhesive layer is activated by heating the adhesive layer of the heat-sensitive adhesive label 1 in which the adhesive layer is activated.
, So that its both ends overlap each other,
Paste on T bottle B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a heat-sensitive adhesive label on a PET bottle, and a PET bottle on which the heat-sensitive adhesive label is mounted, and more particularly to a heat-sensitive adhesive mounted on a PET bottle. The present invention relates to a method for mounting a heat-sensitive adhesive label, in which the adhesive layer of the heat-sensitive adhesive label does not easily remain on the PET bottle when the heat-sensitive adhesive label is removed, and a PET bottle to which the heat-sensitive adhesive label is mounted.

[0002]

2. Description of the Related Art For example, a PET bottle obtained by blow-molding a polyester resin mainly composed of polyethylene terephthalate is generally used as a container for holding a liquid product such as a soft drink. Such PET bottles may be provided with a heat-sensitive adhesive label having an adhesive layer formed by applying a heat-sensitive adhesive to the inner surface, in addition to a shrink label or a stretch label.

[0003] By the way, in the heat-sensitive adhesive label mounted on a PET bottle as described above, a heat-sensitive adhesive is applied to the inner surfaces of both ends of a label substrate formed of a biaxially oriented polypropylene film (OPP). Thus, the adhesive layer is partially formed, and one end of the heat-sensitive adhesive label on which the adhesive layer is formed is adhered and fixed to the body of the PET bottle, and then the heat-sensitive adhesive label is wrapped around the body of the PET bottle. The other end of the heat-sensitive adhesive label on which the adhesive layer is formed is overlapped with one end of the heat-sensitive adhesive label that is adhered and fixed to the body of the PET bottle, and both ends of the heat-sensitive adhesive label are bonded to each other. By fixing, it is designed to be mounted on a PET bottle.

[0004] When recycling a used PET bottle on which the heat-sensitive adhesive label is attached as described above,
The heat-sensitive adhesive label attached to the PET bottle is
Pulverize in a state where it is removed from the T bottle, and use this
Since it is common to recycle ET bottles or use them as raw materials for other resin products, in order to efficiently recycle PET bottles, the surface of the PET bottle with the heat-sensitive adhesive label removed must be It is desirable that the adhesive layer of the heat-sensitive adhesive label formed of a resin component different from that of the PET bottle does not remain attached.

As described above, in order to prevent the adhesive layer of the heat-sensitive adhesive label from remaining on the surface of the PET bottle, it is necessary to adhere the heat-sensitive adhesive forming the adhesive layer of the heat-sensitive adhesive label to the PET bottle. Although it is conceivable to reduce the strength, the use of a heat-sensitive adhesive having a low adhesive strength to a PET bottle also weakens the adhesive strength to the label base material forming the heat-sensitive adhesive label at the same time. When attaching to a bottle, the adhesive force of the part where the both ends of the heat-sensitive adhesive label are overlapped and fixed is weakened, and the heat-sensitive adhesive label once attached to the PET bottle is There is a problem that it comes off easily.

Accordingly, an object of the present invention is to remove the heat-sensitive adhesive label once attached to the PET bottle, and to forcibly remove the heat-sensitive adhesive label from the PET bottle. It is an object of the present invention to provide a method for mounting a heat-sensitive adhesive label on which an adhesive layer hardly adheres and a PET bottle to which the heat-sensitive adhesive label is mounted.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a label base material formed of a polyolefin resin, and an intermediate layer directly or at an inner surface at both ends of the label base material. A method of mounting a heat-sensitive adhesive label on a PET bottle, the heat-sensitive adhesive label comprising a heat-sensitive adhesive formed by a heat-sensitive adhesive having a higher adhesive strength to the label substrate side than an adhesive strength to the PET bottle, which is laminated through the PET bottle. Applying a corona discharge treatment to the outer surface of the supplied heat-sensitive adhesive label, and heating the adhesive layer of the heat-sensitive adhesive label subjected to the corona discharge treatment on the outer surface, thereby forming the adhesive layer. Activating and adhering the heat-sensitive adhesive label having the activated adhesive layer to the PET bottle such that both ends thereof are overlapped with each other. Method of mounting takes heat sensitive adhesive label and a step is to provide.

As described above, this method of mounting a heat-sensitive adhesive label generally uses a heat-sensitive adhesive label provided with a label substrate formed of a polyolefin resin having a small peel strength of the heat-sensitive adhesive. Therefore, even if it is not possible to sufficiently secure the adhesive strength between the label base materials as it is, the heat-sensitive adhesive label is
By applying a corona discharge treatment to the outer surface of the heat-sensitive adhesive label (label base material) before attaching to the T bottle,
The wettability of the outer surface of the heat-sensitive adhesive label (label base) can be increased. As a result, the peel strength at both ends of the heat-sensitive adhesive labels adhered and fixed in a state of being superposed on each other is increased, and the heat-sensitive adhesive labels once mounted on the PET bottle are not easily detached.

Further, as described above, the heat-sensitive adhesive label is
Immediately before attaching to the ET bottle, the outer surface of the heat-sensitive adhesive label (label base material) is subjected to corona discharge treatment. Even if the adhesive label is continuously connected and wound up in a roll,
Blocking hardly occurs, and the handling of the heat-sensitive adhesive label is not hindered.

[0010] The heat-sensitive adhesive label used is:
As described above, since an adhesive layer formed by a heat-sensitive adhesive having an adhesive strength to the label substrate side larger than an adhesive strength to the PET bottle is provided, the used P
In order to separate the PET bottle and the heat-sensitive adhesive label by forcibly removing the heat-sensitive adhesive label attached to the PET bottle to recycle the ET bottle, the adhesive layer of the heat-sensitive adhesive label is applied to the surface of the PET bottle. It is possible to efficiently recycle used PET bottles without remaining adhesion.

In particular, as in the method for mounting a heat-sensitive adhesive label according to claim 2, a label substrate formed of a biaxially stretched polypropylene film and ethylene vinyl acetate having a vinyl acetate content of 10 to 30% by weight. It is desirable to use a heat-sensitive adhesive label having an adhesive layer formed by a copolymer.

Further, as in the method for mounting a heat-sensitive adhesive label according to claim 3, the outer surface of the heat-sensitive adhesive label has an outer surface with a wetting index of 400 μN / cm or more. When the corona discharge treatment is applied to both sides, sufficient peel strength (adhesion strength) is applied to both ends of the heat-sensitive adhesive label adhered and fixed in a state where they are superimposed on each other.
Is secured.

[0013]

Embodiments will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the heat-sensitive adhesive label 1 is a label attached to the body of a PET bottle, and is a 50 μm thick transparent label substrate 11 formed of a biaxially oriented polypropylene film. When,
On substantially the entire inner surface of the label substrate 11, a printing layer 12 obtained by gravure printing the product name, component display, design, and the like of the liquid product contained in the PET bottle, and a label substrate 11 on which the printing layer 12 is formed Thickness 5 to 2 laminated on the inner surface side of
And an adhesive layer 13 having a thickness of 0 μm.
Are partially formed only at both ends of the label substrate 11.

The biaxially stretched polypropylene film forming the label substrate 11 has a very low polarity and excellent chemical stability, so that it can be sufficiently separated from the printing ink forming the printing layer 12. High adhesion cannot be secured. Accordingly, the printed layer 12 is formed in a state where the inner surface of the label substrate 11 is subjected to corona discharge treatment to increase the wettability of the surface. Sex) is secured.

The adhesive layer 13 is formed by coating a solution or emulsion containing a hot-melt type heat-sensitive adhesive, such as ethylene vinyl acetate copolymer or ethylene acrylic acid copolymer, as a main component using a method such as gravure printing. By comparing the adhesive strength to the PET bottle and the adhesive strength to the label substrate 11 (printing layer 12), the label substrate 11 (printing layer 12)
Is higher than the adhesion strength to the PET bottle. Therefore, when the heat-sensitive adhesive label 1 is adhered to the PET bottle and then peeled off from the PET bottle, the entire adhesive layer 13 is held on the label substrate 11 side, and does not remain on the PET bottle side.

As the heat-sensitive adhesive, it is desirable to use a solution in which an appropriate amount of polyethylene wax or the like is added to an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 30% by weight, or an aqueous or alcoholic emulsion. . If the content of vinyl acetate is less than 10% by weight, the low-temperature adhesion is inferior, and if it exceeds 30% by weight, blocking becomes easy.

Hereinafter, the above-mentioned heat-sensitive adhesive label (hereinafter, referred to as the label)
It is called a label. The method of mounting the (1) on the body of the PET bottle will be described with reference to a labeling device 2 shown in FIG.

As shown in FIG.
While forming the label 1 by sequentially cutting the long label-forming base material R to which the above-mentioned label 1 is continuously connected at the cutting position β, the label 1 is moved to a predetermined label sticking position α. The long label forming base material R wound in a roll is continuously attached to the outer peripheral surface of the body portion of the PET bottle (hereinafter, referred to as a bottle) B that is conveyed, and is continuously placed at the cutting position β. -Forming substrate supply means 20 including a supply roller 21 for supplying the toner to the substrate and a corona discharge treatment device 22 installed on the upstream side of the supply roller 21, and a label forming apparatus supplied by the label-forming substrate supply means 20 At the cutting position β, the substrate R is sequentially cut at a predetermined cut pitch to form the label 1, and is transported to a cutting means 30 including a fixed blade 31 and a rotary blade 32, and a label sticking position α. A label sticking means 40 for sticking the label 1 to the outer peripheral surface of the body of the bottle B to come, and individual labels 1 cut from the label forming base material R by the cutting means 30 are delivered to the label sticking means 40. And a bottle transfer means 60 for transferring the bottle B to the label sticking position α.

As shown in the figure, the label attaching means 40 is provided at the label transfer position γ.
And a sticking drum 41 for sucking and holding the label 1 delivered from the outside on the outer peripheral surface so that the sticking surface thereof faces outward, and the sticking drum 41 before sucking and holding the label 1 on the sticking drum 41. Infrared heater 42 for preliminarily heating the outer peripheral surface
(For example, a near-infrared heater using a halogen lamp)
And an infrared heater 43 for heating the label 1 sucked and held by the sticking drum 41.
The label 1 sucked and held on the outer peripheral surface of the
1 rotates and conveys to the label sticking position α, and at the label sticking position α, the bottle conveying means 6
The label 1 is stuck to the torso of the bottle B by bringing the sticking surface of the label 1 into contact with the outer peripheral surface of the torso of the bottle B conveyed by 0.

The label delivery means 50 includes a cutting means 30
And a small-diameter pulley 51a and a large-diameter pulley 51b installed near the attaching drum 41, respectively.
1a and 51b, the label transport belt 52 circulating between the cutting means 30 and the attaching drum 41, and the pulleys 51a and 51b for receiving the label 1 cut from the label forming base material R. A suction means 53 for temporarily sucking and holding the label 1 on the label conveying belt 52 on the cutting means 30 side, and a label conveying belt 52 from the cutting means 30 side from the position where the suction holding by the suction means 53 is released. Label 1 conveyed to sticking drum 41
And a first label guide 54 and a second label guide 55 as positioning guide means for guiding the outer surface of the sticking drum 41 while positioning the transport belt 52. The transport belt 52 has a large-diameter pulley 51b. Rotation is performed by a driving means such as a motor so as to circulate, and a predetermined tension is constantly applied by a tension roller 51c.

The bottle conveying means 60 includes a plurality of bottles B conveyed by a belt conveyor or the like (not shown).
Is attached to the label attaching position α by a star wheel 62, a screw conveyor 63 and a star wheel 64, which are sequentially supplied at predetermined intervals, and the bottle B supplied to the label attaching position α. The bottle B is attached to the adhering drum 41 so that the bottle B is sent out while being in contact with the outer peripheral surface of the drum 41 and rotating by the rotational force of the adhering drum 41.
And a bottle discharge section 66 such as a belt conveyor for carrying out the bottle B sent out from the label sticking position α. The bottle B is placed at the label sticking position. By rotating while contacting the attaching drum 41 at α, the label 1 sucked and held on the outer peripheral surface of the attaching drum 41 is attached while being wound around the outer peripheral surface of the body of the bottle B.

The labeling apparatus 2 configured as described above
First, the long label-forming base material R wound in a roll shape is continuously supplied to the cutting position β by the feed roller 21, but the corona discharge is installed on the upstream side of the feed roller 21. The label forming base material R, in other words, such that the wetting index measured by the processing device 22 in accordance with the wetting test method for a polypropylene film specified in JIS K 6768 is 380 μN / cm or more, preferably 400 μN / cm or more, The outer surface of the label 1 is subjected to corona discharge treatment, and the label-forming substrate R is supplied to the cutting position β in a state where the wettability of the outer surface of the label 1 (the outer surface of the label substrate 11) is enhanced.

The label-forming base material R whose outer surface has been subjected to corona discharge treatment is coated with a heat-sensitive adhesive formed at predetermined intervals by the fixed blade 31 and the rotary blade 32 of the cutting means 30 at the cutting position β. Individual labels 1 which are sequentially cut at substantially the center position in the width direction of the portion and have adhesive layers 13 at both end portions
Is formed. The individual label 1 formed here is delivered to the label attaching means 40 via the label delivering means 50, and is suction-held on the outer peripheral surface of the attaching drum 41.

In this manner, the label 1 sucked and held on the outer peripheral surface of the sticking drum 41 is transported to the label sticking position α by the rotation of the sticking drum 41. The heating is performed by 43, so that the sheet can be bonded before reaching the label sticking position α.

At the label sticking position α, the bottle conveying means 6
By bringing the sticking surface of the label 1 sucked and held on the outer circumferential surface of the sticking drum 41 into contact with the outer circumferential surface of the bottle B conveyed by the label 0, the label 1 is attached to the torso of the bottle B.
Is affixed. First, one end side of the label 1 sucked and held on the outer peripheral surface of the sticking drum 41 is adhesively fixed to the outer peripheral surface of the bottle B via one adhesive layer 13, and then the label 1 is attached to the outer peripheral surface of the bottle B. Label 1
The other end of the label 1 is overlapped with one end of the label 1 already bonded and fixed to the outer peripheral surface of the body of the bottle B, and both ends of the label 1 are bonded and fixed to each other via the other adhesive layer 13. Thus, the label 1 is attached to the bottle B. The bottle B having the label 1 attached to the outer peripheral surface of the body in this manner
Is carried out by the bottle discharge section 66 of the bottle conveying means 60.

As described above, this label 1
The adhesive layer 13 is made of an ethylene vinyl acetate copolymer which is a heat-sensitive adhesive having a low adhesive strength to the bottle B so that the adhesive layer 13 does not remain on the bottle B when peeled off from the bottle B.
3, the label base material 1 is left as it is.
1 could not obtain sufficient adhesive strength,
Cannot be bonded and fixed sufficiently to each other.

However, as described above, the label 1
Immediately before affixing to the outer peripheral surface of the body of the bottle B, that is, immediately before cutting the label-forming base material R to form the label 1, the corona discharge treatment device 22 applies the label-forming base material R (label 1). By performing corona discharge treatment on the outer surface, the wettability of the outer surface of the label 1 (the outer surface of the label base material 11) is increased, so that the adhesion of the adhesive layer 13 to the label base material 11 is improved. The peel strength at both ends of the label 1 which is adhered and fixed in the superposed state increases, and the label 1 once attached to the bottle B does not easily come off.

In particular, the wetting index of the outer surface of the label 1 is 38
Since the outer surface of the label 1 is subjected to the corona discharge treatment so as to be 0 μN / cm or more, preferably 400 μN / cm or more, a sufficient peel strength (adhesive strength) can be easily secured.

Further, as described above, the corona discharge treatment is applied to the outer surface of the label 1 (label base material 11) immediately before the label 1 is attached to the bottle B. By winding the label-forming base material R in a state in which a large number of labels 1 are continuously connected in a roll shape, even if the adhesive layer 13 and the outer surface of the label base material 11 come into contact with each other, it is difficult for blocking to occur, and The handleability of the forming substrate R (label 1) is not hindered.

In the above-described embodiment, the label substrate 11 is made of the label 1 formed of biaxially oriented polypropylene. However, the present invention is not limited to this. Can be used.

In the above embodiment, the adhesive layer 13
Uses a label 1 formed of an ethylene-vinyl acetate copolymer, but is not limited to this, and forms an adhesive layer with various heat-sensitive adhesives having low adhesive strength to a PET bottle. Can be. Where P
In order to prevent the adhesive from remaining on the PET bottle when peeled off from the ET bottle, it is needless to say that the adhesive strength to the label substrate side must be higher than the adhesive strength to the PET bottle.

In the above-described embodiment, since the printing layer 12 as an intermediate layer is formed on substantially the entire inner surface of the label substrate 11, the adhesive layer 13 is laminated on the printing layer 12. The present invention is not limited to this. For example, when the printing layer does not exist at both ends of the label substrate, it is also possible to directly form the adhesive layer on the inner surface of the label substrate, Alternatively, it is also possible to provide a primer layer between the adhesive layer and the adhesive layer.

In the above-described embodiment, the heat-sensitive adhesive label is attached to the round PET bottle having the cylindrical body. However, the present invention is not limited to this. It is also possible to use a square PET bottle having the following, and the labeling device is not limited to that used in the above-described embodiment.

In the above-described embodiment, the label 1 and the label-forming base material R are clearly distinguished. However, the label-forming base material R is a long heat-sensitive adhesive having no outer surface subjected to corona discharge treatment. It can also be considered a sex label.

[Brief description of the drawings]

FIG. 1 is a plan view showing a heat-sensitive adhesive label used in a mounting method according to the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a schematic plan view showing a labeling device for attaching the heat-sensitive adhesive label to a PET bottle.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heat-sensitive adhesive label 2 labeling device 11 label substrate 12 printing layer 13 adhesive layer 20 label forming substrate supply means 22 corona discharge treatment device 30 cutting means 40 label attaching means 50 label delivery means 60 bottle transport means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 3/10 G09F 3/10 C

Claims (4)

[Claims] 1. A label substrate formed of a polyolefin-based resin, which is laminated directly or through an intermediate layer on inner surfaces of both ends of the label substrate, and has a higher adhesive strength to a PET substrate than to a PET bottle. A method for attaching a heat-sensitive adhesive label provided with an adhesive layer formed of a heat-sensitive adhesive having a high adhesive strength to a PET bottle, wherein a corona discharge treatment is performed on an outer surface of the supplied heat-sensitive adhesive label. Activating the adhesive layer by heating the adhesive layer of the heat-sensitive adhesive label having an outer surface subjected to a corona discharge treatment; and the heat-sensitive adhesive label having the adhesive layer activated. With the two ends overlapping each other,
A method for mounting a heat-sensitive adhesive label comprising a step of attaching to a bottle. 2. A thermosensitive device comprising: the label substrate formed by a biaxially stretched polypropylene film; and the adhesive layer formed by an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 30% by weight. The method for mounting a heat-sensitive adhesive label according to claim 1, wherein an adhesive label is used. 3. The heat-sensitive adhesive label according to claim 1, wherein the outer surface of the heat-sensitive adhesive label is subjected to a corona discharge treatment such that a wettability index of the outer surface of the heat-sensitive adhesive label is 400 μN / cm or more. How to attach a heat-sensitive adhesive label. 4. A PET bottle to which the heat-sensitive adhesive label is mounted by the mounting method according to claim 1, 2, or 3.