JP3460946B2 - Label, bottle equipped with the label, and method for recycling the bottle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label capable of removing printed ink, a bottle equipped with the label, a method for removing those inks, a method for recycling and a pellet for recycling the same.

[0002]

2. Description of the Related Art In recent years, bottles made of glass, metal, etc. have been increasing in use year by year because polymers, particularly thermoplastic polymer bottles, have excellent breakage resistance, light weight, transparency and the like. ing. In particular, polymer bottles have been remarkably used in the beverage field, and are used in large amounts from small bottles to large bottles. Among them, the amount of use of a bottle containing polyethylene terephthalate as a main component (hereinafter abbreviated as “PET bottle”) is remarkably increased.

On the other hand, due to the recent heightened awareness of global environmental problems, it is necessary to deal with the recycling problem of bottles made of thermoplastic polymers. There is great interest in recycling bottles made of thermoplastic polymers, especially PET bottles, and early establishment of a recycling system is required.
Generally, a PET bottle is equipped with a polyolefin-based stretch label, a heat-shrinkable label made of polyester, polystyrene, vinyl chloride or the like, or a tack label made of polypropylene film or the like. PE
Regarding the recycling of T-bottles, usually, with the label attached, it is collected from general consumers and brought to a recycling company.
After cleaning the carried-in bottle, the label is removed by primary crushing, but the crushed product still contains a large amount of label. Therefore, regenerated pellets have been obtained through secondary pulverization, label liquid gravity separation, dehydration / drying, wind gravity separation and pelletizing steps. FIG. 2 shows a process of recovering a thermoplastic polymer as pellets from a typical conventional labeled bottle.

[0004]

In the above-mentioned conventional label and the method for recycling the bottle equipped with the label, the label is separated by various separation steps, but when the purity of the recycled thermoplastic polymer is improved, the material is recycled. There is a problem that the ratio decreases. Further, as impurities in the recycled thermoplastic polymer that has undergone these steps, there are label resins, inks and the like, and there is a problem that the entire recycled pellets are colored even if the amount of ink is small.

Therefore, in order to efficiently recycle the bottle, it is necessary to prevent the mixture of the label and the ink of the label in order to improve the purity of the recycled thermoplastic polymer. So far, the thermoplastic polymer which is the material for the label has been improved, and the polymer having a lower specific gravity than PET, such as polystyrene, polyethylene, which is easily separated from the specific gravity,
Polyolefin labels such as polypropylene have been proposed, but there is a problem that complete separation is impossible because the ink layer is placed on the label and the specific gravity does not become low.

Further, a polyester label of the same kind has been proposed, which does not pose a problem even when mixed in a PET bottle, but the problem that the regenerated pellets are colored because the ink layer cannot be separated remains unsolved.

The present invention solves the problems of the conventional label and the method for recycling the bottle with the label attached,
A label that can easily remove the ink layer, a bottle equipped with the label, a method of removing the ink layer on the label, a method of removing the ink layer on the label from the bottle equipped with the label, and the ink was removed. An object of the present invention is to provide a method for regenerating a label and a bottle and a regenerated pellet.

[0008]

In order to achieve the above object, a PET bottle label of the present invention is a polyester-based label.
A label for a PET bottle, wherein an intermediate layer for removing ink in alkaline hot water is present between the ink layer and the base material layer on at least one surface of the heat-shrinkable film.
It (However, the label 1g is cut into 1cm square pieces.
In 100 cc of deionized water (25 ° C, pH 6-8)
After stirring for 30 minutes, removing ink when washed and dried
Removes ink in alkaline hot water with a rate of 5% or less
The intermediate layer to be cut is 1 g of the label cut into 1 cm squares.
Stir for 30 minutes in 00cc NaOH 3% solution (90 ° C)
After cleaning, the ink removal rate is 90% when washed and dried.
The intermediate layer existing between the ink layer and the base material layer as described above is
means. )

Here, the intermediate layer for removing ink in alkaline hot water means that 1 g of a sample label is cut into 1 cm square pieces, stirred in 100 cc of a 3% NaOH solution (90 ° C.) for 30 minutes, washed with water and dried. The ink removal rate is 90
The intermediate layer is present between the ink layer and the base material layer, which is at least%.

The label having the above-mentioned constitution can easily dissolve and swell the intermediate layer existing between the ink layer and the base material layer by immersing it in alkaline hot water to remove the ink.

In this case, the intermediate layer for removing the ink in the alkaline hot water may be a resin composition capable of swelling or dissolving in the alkaline hot water. The term “dissolved” as used herein does not mean that it is completely dissolved in an alkaline solution in a molecular state, but may be dispersed in the form of fine particles.

The resin composition capable of swelling or dissolving in alkaline hot water is at least one selected from polyester resins, polyacrylic resins, acrylic modified polyester resins, polyurethane resins, acrylic modified polyurethane resins and polyolefin resins. Preferably there is.

In the label having the above construction, the ink layer is easily peeled off, and the ink layer can be more easily removed by immersing it in alkaline hot water.

[0014]

[0015]

[0016]

In the label, the heat shrinkage rate of the polyester heat shrinkable film may be 30 to 80%. Here, the heat shrinkage is the shrinkage measured by immersing in hot water of 95 ° C. for 10 seconds.

The label having the above structure has excellent practicality as a display label for various articles.

Further, the label may contain a resin composition in which the intermediate layer existing between the ink layer and the substrate layer can swell or dissolve in alkaline hot water.

In the label having the above structure, the intermediate layer existing between the ink layer and the base material layer can be easily swollen or dissolved in alkaline hot water.

A bottle is equipped with the label.

The bottle having the above-mentioned structure can be easily used as a labeled bottle because the ink layer can be removed by swelling or dissolving the intermediate layer existing between the ink layer on the label and the substrate layer. The polyester can be reused.

[0023]

In the bottle of the present invention having the above-mentioned constitution, the ink layer can be removed by swelling or dissolving the intermediate layer existing between the ink layer and the substrate layer, and after removing the ink layer. , The bottle and label can be put on the recovery step at the same time and reused.

In the bottle, the heat shrinkage rate of the mounting label in the bottle circumferential direction may be 0.1% or more and less than 80%.

In addition, the ink removing method uses the label
It is characterized in that it is immersed in alkaline hot water to swell or dissolve the intermediate layer existing between the ink layer on the label and the substrate layer, and the ink layer is removed from the label.

In the ink removing method having the above structure, the ink layer and the film forming the label can be easily separated.

In addition, the ink removing method is to remove the ink layer by immersing the bottle with the label in alkaline hot water to dissolve or swell the layer existing between the ink layer on the label and the substrate layer. It is characterized by doing.

The ink removal method having the above structure is directly P a label and bottle ink layer is removed
It is possible to shift to the ET (polyester) recovery step.

Further, the method of recycling the labeled bottle is characterized in that the label from which the ink layer has been removed by the above method is melted together with the bottle in which the label has been mounted, and is recycled.

In the method of recycling the labeled bottle having the above-mentioned structure, the label and the bottle without the ink layer can be directly recycled to the collecting step.

Further, the regenerated pellets are characterized by being obtained by the above method.

The regenerated pellets having the above-mentioned structure are excellent regenerated pellets suitable for effective use of resources that can be reused for various moldings without containing ink.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the label of the present invention, the bottle equipped with the label, and the recycling method thereof will be described below.

The base film of the label of the present invention includes:
There is no particular limitation as long as it is a polyester heat-shrinkable film.

It is more preferable to use a heat-shrinkable polyester film in which the interface between the ink layer and the ink layer is peeled off due to heat shrinkage of the film in the washing step and removal is easy. The heat-shrinkable label attached to the bottle by heat-shrinking preferably still has residual shrinkability, and after removing from the bottle and immersing in hot water at 95 ° C for 10 seconds, the heat measured in the radial direction of the bottle Shrinkage rate is 0.
It is preferably 1% or more and less than 80%. When the heat shrinkage is less than 0.1%, the force generated at the interface is reduced due to the shrinkage of the ink layer and the thermoplastic film, and the ink dropout rate is reduced. On the other hand, when the heat shrinkage is 80% or more, the label is bent. Is large and the ink removal rate is reduced, which is not preferable.

For use as a base film for a label,
The method for producing a preferable heat-shrinkable polyester film and its characteristics are shown below.

The polyester constituting the heat-shrinkable polyester film is mainly composed of terephthalic acid or 2,6-naphthalenedicarboxylic acid as a main acid component, and ethylene glycol or tetramethylene glycol as a main glycol component. However, polyesters containing other acidic components and glycol components as main components may be used. Further, as the acidic component which can be copolymerized, isophthalic acid, cyclohexanedicarboxylic acid,
2,6-naphthalenedicarboxylic acid, terephthalic acid and the like can be optionally used. Further, tetramethylene glycol, ethylene glycol, trimethylene glycol, cyclohexanedimethanol and the like can be arbitrarily used as the glycol component which can be copolymerized.

A film obtained by any method such as an extrusion method or a calendering method using such a polymer is stretched in one direction from 2.5 times to 7.0 times, preferably from 3.0 times to 6.0 times. ,
It is stretched 1.0 to 2.0 times or less, preferably 1.1 to 1.8 times in the direction perpendicular to the above direction. Stretching in the first direction is a major requirement that has a large effect on obtaining a high heat shrinkage ratio, and stretching in the direction orthogonal to the first direction means that the film is stretched in the first unidirectional direction. It is extremely effective in resolving the poor impact resistance and tear resistance.

However, the heat shrinkage ratio of the heat shrinkable film in the main shrinkage direction is about 30 to 80%, but when it is stretched in the direction perpendicular to the initial direction by more than 2.0 times, it becomes the main shrinkage direction. The heat shrinkage in the perpendicular direction becomes too large, and the finish of the film surface after the heat shrinkage becomes wavy. In order to suppress the waviness of the film, the heat shrinkage in the direction perpendicular to the main shrinkage direction is 15% or less, preferably 8 to 9% or less,
More preferably, it is recommended to be 7% or less. The stretching means is not particularly limited, and roll stretching, long-interval stretching, tenter stretching, and the like are applied, and the shape may be flat, tubular, or the like.

The stretching is carried out by sequential biaxial stretching, simultaneous biaxial stretching, uniaxial stretching or a combination thereof.
Further, the film used for the label of the present invention is stretched, for example, in a longitudinal uniaxial manner, a lateral uniaxial manner, a longitudinal and transverse biaxial manner, and particularly in biaxial stretching, one of the two is oriented in the right angle direction first. It is effective to carry out sequential biaxial stretching, and the order may be either first. When the simultaneous biaxial stretching method is used, the stretching order may be vertical-horizontal simultaneous, vertical-first, or horizontal-first. Although heat setting after stretching is carried out depending on the purpose, it is recommended to pass a heating zone of 30 to 150 ° C for about 1 to 30 seconds in order to prevent dimensional change under high temperature in summer. It In addition, stretching up to 70% may be performed before or after such treatment, or both. In particular, it is preferable to extend in the main direction and relax in the direction perpendicular to the main contraction direction, and it is better not to extend in the right direction.

In order for the shrinkable film used in the label of the present invention to exhibit suitable properties, not only the above draw ratio but also a temperature above the average glass transition point (Tg) of polyester, for example, below Tg + 80 ° C. Preheating and stretching may also be mentioned as effective means. In particular, the above-mentioned treatment temperature in the main-direction stretching (main shrinkage direction) is extremely effective in suppressing the heat shrinkage ratio in the direction perpendicular to the direction and bringing the minimum value in the temperature range of 80 ± 25 ° C as described above. is important. Further, after the stretching, the shrinkage property becomes better and stable by keeping the tension state after stretching and cooling while applying stress to the film, or by further cooling.

The surface orientation coefficient of the film thus obtained is preferably 100 × 10 ⁻³ or less. This is because if the surface orientation coefficient exceeds 100 × 10 ⁻³ , the surface tends to be broken by an impact external force, and is easily broken even by a small amount of external damage. On the other hand, the birefringence is 15 × 10 ^{−3 to} 160 × 10 ^−3.
When the birefringence is less than 15 × 10 ⁻³ , the heat shrinkage and shrinkage stress in the longitudinal direction are insufficient, and when it exceeds 160 × 10 ⁻³ , scratch resistance and impact strength decrease, and the film has However, the effectiveness is reduced in practice. The thickness of the polyester heat shrink film used in the label of the present invention is 6 to 2
A range of 50 μm is practical.

The label of the present invention has an intermediate layer existing between the ink layer and the base material layer on at least one side thereof,
The intermediate layer existing between the ink layer and the base material layer can be removed from the base material layer by swelling or dissolving in alkaline hot water. Here, the intermediate layer for removing ink in alkaline hot water means the sample label 1
g is cut into 1 cm square pieces, stirred in 100 cc of a 3% solution of NaOH (90 ° C.) for 30 minutes, washed with water and dried to mean an intermediate layer having an ink removal rate of 90%. What is removed is that the intermediate layer swells or dissolves mainly in alkaline hot water. Practically, washing with weak alkaline hot water is usually carried out for about 30 minutes, during which the ink layer may fall off. Further, from the viewpoint of increasing the purity of the regenerated pellets as much as possible, it is preferable that the intermediate layer itself can be removed by 90% or more by the above treatment.

The resin swellable or soluble in alkaline hot water used in the intermediate layer existing between the ink layer and the base material layer is particularly limited as long as it has a function of removing the ink layer. Although not required, it is necessary for the resin to have a hydrophilic group introduced so that it can swell or dissolve in alkaline hot water. As the hydrophilic group, a hydroxyl group, a polyethylene glycol group, a carboxylic acid group, a carboxylate group, a sulfonate group, a sulfonate group,
Examples thereof include a phosphonic acid group and a phosphonic acid group. Further, since it is used as a label for bottles, it is necessary to prevent the ink layer from being peeled off when the bottle is normally used. Specifically, 1 g of sample label is cut into 1 cm squares and 1
3 in 00cc of deionized water (25 ° C, pH 6-8)
It is preferable that the ink removal rate is 5% or less when washed with water and dried after stirring for 0 minutes. First, it is necessary to adjust the type and amount of hydrophilic groups. For that purpose, the kind and amount of the above hydrophilic groups are adjusted. When the hydrophilic group is carboxylate group, sulfonate or phosphonate, the boiling point is 200.
A neutralized product using an amine having a temperature of ℃ or less is preferable.

Examples of resins into which these hydrophilic groups are introduced include polyester resins, polyacryl resins, acryl-modified polyester resins, polyurethane resins and polyolefin resins. Preferred are polyester resins, acrylic modified polyester resins and acrylic modified polyurethane resins. As the acrylic-modified polyester resin, a method of using an acrylic macromonomer having two or more hydroxyl groups at only one end during polyester synthesis, a method of synthesizing polyester, and then polymerizing the acrylic monomer in the presence of the polyester resin, etc. A preferred example is a polyester obtained by grafting the acrylic polymer obtained as a branching moiety. As an acrylic modified polyurethane resin, a method of using an acrylic macromonomer having two or more hydroxyl groups at only one end during polyurethane synthesis, a method of polymerizing an acrylic monomer in the presence of this polyurethane resin after synthesizing polyurethane, etc. A preferred example is polyurethane obtained by grafting the resulting acrylic polymer as a branch portion, and polyester polyol is preferred as the polyol used here.

Although not particularly limited, for example, a compound soluble or swellable in alkaline hot water may be added to these resins. Examples of the compound soluble or swellable in alkaline hot water include inorganic salts such as sodium chloride, sodium sulfate, potassium nitrate, sodium acetate and ammonium sulfate, organic acids such as ascorbic acid, sebacic acid and azelaic acid or salts thereof, and polyethylene oxide. Polymers such as polytetramethylene oxide, polyvinyl alcohol and polyacrylic acid or metal salts thereof, and copolymers thereof. In addition, examples of the above-mentioned compound include those that are liquid at room temperature, and specifically, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, isobutyl alcohol, tert-butyl alcohol, cyclohexyl alcohol, and benzyl alcohol. Monomethyl, monoethyl, monopropyl, monobutyl ether or monomethyl, monoethyl ester of polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol glycerin, pentaerythritol, etc., dioxane, acetone, methyl ethyl ketone, diacetone alcohol, dimethyl Formamide, tetrehydrofuran, etc. are mentioned. Among them, those having a high boiling point are preferable because they are required to remain in the ink layer, and specifically, those having a boiling point of 50 ° C. or higher are preferable, and the monohydric alcohol monohydric alcohol is more preferable because it may be dissolved in alkaline hot water. Alkyl ethers are particularly preferred. Used for the intermediate layer existing between the ink layer and the base layer, a method of laminating a resin capable of swelling or dissolving in alkaline hot water on a polyester heat shrinkable film is a general coating method or coating during film formation, A method of stretching after drying may be used. A co-extrusion method may be used as long as it is a resin that can be melt-extruded. Further, a resin which can swell or dissolve in alkaline hot water may be laminated by laminating such as general dry laminating or extrusion laminating. However, the coating method is most suitable for obtaining the laminated film at low cost.

The ink used in the label of the present invention comprises an ink pigment, a binder, a solvent, etc. Examples of the binder include nitrocellulose type, chlorinated polypropylene type, polyester type, acrylic type, polyester urethane type and acrylic. A urethane-based binder is used. In particular, an ink having a polyester-based, acrylic-based, polyester urethane-based, or acrylic urethane-based binder is preferable for the polyester-based film.
The pigment for coloring the ink is not particularly limited and may be a commonly used pigment. Further, the ink used in the present invention, if necessary, a weather resistance agent, an optical brightener, a lubricant,
You may contain additives, such as a crosslinking agent. Examples thereof include a method of adding to a commonly used ink, for example, a coloring material composed of a pigment or a dye, a binder, and an ink having a volatile organic solvent as a constituent component. Further, in the present invention, the ink layer may contain a compound swellable or swellable in alkaline hot water. Examples of the compound soluble or swellable in alkaline hot water include sodium chloride, sodium sulfate and potassium nitrate. , Inorganic salts such as sodium acetate and ammonium sulfate, organic acids such as ascorbic acid, sebacic acid and azelaic acid or salts thereof, polyethylene oxide,
Examples thereof include high molecular weight polyethers such as polytetramethylene oxide, polyvinyl alcohol, polyacrylic acid or metal salts thereof, and copolymers thereof. Also,
Examples of the above compound include those that are liquid at room temperature, and specifically, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, isobutyl alcohol, tert-butyl alcohol, cyclohexyl alcohol, and benzyl alcohol, Monomethyl, monoethyl, monopropyl, monobutyl ether or monomethyl of polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol glycerin and pentaerythritol, etc., dioxane, acetone, methyl ethyl ketone, diacetone alcohol, dimethylformamide, Examples thereof include tetrehydrofuran. Among them, those having a high boiling point are preferable because they are required to remain in the ink layer, and specifically, those having a boiling point of 50 ° C. or higher are preferable, and the monohydric alcohol monohydric alcohol is more preferable because it may be dissolved in alkaline hot water. Alkyl ethers are particularly preferred.

As a method of printing the ink for producing the label of the present invention, a known method can be used.
For example, gravure printing, flexographic printing, screen printing and the like can be mentioned. The thickness of the ink layer is 0.1 μm
˜100 μm is preferred. If the thickness is less than 0.1 μm, the coloration of the ink is insufficient, while if it exceeds 100 m, the ink layer becomes brittle and cracks easily.

In the present invention, the intermediate layer existing between the ink layer and the substrate layer from the label is swollen or dissolved to remove the ink layer by immersing it in alkaline hot water. Practically, after cutting 1 g of label to 1 cm or less,
The ink layer can be removed by stirring in 100 cc of 3% NaOH solution at 0 ° C. for 30 minutes or more. After that, there is a method in which the removal rate of the ink layer is 90% or more by washing after that, filtering, washing with water and drying. Specifically, in terms of label processing ability and processing equipment, a crushed form of the label is preferable, and a size of the crushed film is preferably 0.1 mm square to 10 cm square. If it is less than 0.1 mm square, the efficiency in the subsequent filtration step is poor, while if it exceeds 10 cm square, it takes time to remove the ink. In addition, the hot water used in the process of removing the ink layer must be alkaline
Is preferably 9.0 or more. Examples of the method of imparting alkalinity include addition of NaOH, KOH, ammonia or the like to hot water. The temperature of the cleaning liquid is 50 to 100
The hot water of ℃ is preferred, and the higher the temperature, the higher the removal efficiency. The amount of the label and the washing liquid used is not uniform depending on the size of the label, but it is required to be 5 to 20 times for very large ones and 0.2 to 5 times for the crushed small ones. In addition, a circulation type flush may be performed to improve efficiency. The washing time is preferably within 30 minutes in the recycling process. The dropout rate of the ink layer may be 90% or more, preferably 98% or more, more preferably 99.9% or more.

The label of the bottle of the present invention can be attached by a conventional method so as to cover at least the body. Further, the collected, the bottle equipped with the label of the present invention, typically crushed after washing the bottle,
Next, remove the ink layer in warm alkaline water, wash and dry as it is, and recycle PET (polyester
Le) Get flakes. This is recycled PET with an extruder
It can be recycled into (polyester) pellets for use.

[0052]

EXAMPLES Specific examples of the present invention will be given below.

Production Example of Polyester Resin 460 g of dimethyl terephthalate, 460 g of dimethyl isophthalate, and fumaric acid were placed in a stainless steel autoclave equipped with a stirrer, a thermometer and a partial circulation type cooler.
29 g, ethylene glycol 341 g, 3 methyl pentanediol 650 g and tetra-n-butyl titanate 0.
52 g was charged, and the transesterification reaction was performed at 160 to 220 ° C. for 4 hours. Then raise the temperature to 250 ° C,
The reaction system was gradually depressurized and then reacted under a reduced pressure of 0.2 mmg for 1 hour and 30 minutes to obtain a polyester resin. The obtained polyester resin A was light yellow and transparent.

Production Example of Acrylic-Modified Polyester Resin In a glass flask equipped with a stirrer, a thermometer, and a reflux condenser, fumaric acid was added to the polyester resin obtained by the method shown in the production example of polyester resin in an amount of 5 mol% in the acid component. 75 g of the copolymerized polyester resin, 56 g of methyl ethyl ketone and 19 g of isopropyl alcohol were charged, and the mixture was heated and stirred to dissolve the resin. To the dissolved resin, 17.5 g of methacrylic acid, 7.5 g of ethyl acrylate and a solution of 1.2 g of azobisdimethylvaleronitrile dissolved in 10 g of methyl ethyl ketone were added dropwise at a constant rate.
It was stirred for another 3 hours. Then, 300 g of water and 25 parts of triethylamine were added to the reaction solution, and the mixture was further stirred for 1 hour. Next, the temperature of the solution was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off to obtain an acrylic modified polyester resin. (Example 1) Polyester film having a thickness of 50 μm (heat shrinkage in the circumferential direction after label processing 72%:
The above-mentioned acrylic modified polyester resin is applied to S5630 manufactured by Toyobo Co., Ltd., dried at 60 ° C., a 0.1 μm intermediate layer is laminated, and shrink EX is used as an ink on this intermediate layer.
Solid green printing (manufactured by Toyo Ink Co., Ltd.), gold, and white were sequentially printed by gravure printing, and dried in an oven at 60 ° C.
The total thickness of the ink layer was 10 μm. Using a solvent, the printing film was bonded to a bottle having a maximum outer circumference of +20 mm and cut into a tube having a width of 12 cm. The label was attached from the lower part of the neck of the 2 liter PET bottle to the body, and contracted using a steam tunnel at 80 ° C. Remove the label with scissors, and apply 3% sodium hydroxide solution at 95 ° C to the label.
It was immersed for 0 minutes with stirring. When the label was taken out and observed, the ink layer was completely removed. Further, the regenerated pellets collected according to the process of FIG. 1 were visually observed and no coloring was observed.

[0055]

(Comparative Example 1) Green, gold and white were directly applied to the polyester film having a thickness of 50 μm (heat shrinkage in the circumferential direction after label processing 72%: S5630 manufactured by Toyobo Co., Ltd.) of Example 1 directly. The same procedure was performed except that solid printing was sequentially performed by gravure printing and drying was performed in an oven at 60 ° C. When the label taken out was observed, almost all of the ink layer remained without being removed.

[0057]

The PET bottle label of the present invention can be easily coated with polyester by immersing it in alkaline hot water.
The ink layer can be removed from the heat-shrinkable film, and the ink layer can be easily peeled off by making the polyester film constituting the label a heat-shrinkable film, and the ink can be more easily removed by dipping it in alkaline hot water. The layer can be removed.

[0058]

Further, by setting the shrinkage rate of the polyester heat shrinkable film constituting the label to 30 to 80%, it has excellent practicality as a display label for various articles.

Further, since the intermediate layer for removing the ink layer in the alkaline hot water constituting the label contains a compound capable of swelling or dissolving in the alkaline hot water, the label is shredded and the ink layer is dried in the alkaline hot water. It can be easily separated.

Further, the bottle is equipped with a label having a layer for removing the ink layer in alkaline hot water on at least one side of the polyester heat shrinkable film, so that the label on the label after use is used. easily P as a bottle with a label because it is easy to separate the ink layer
ET (polyester) can be reused.

[0062] needed in this case, by making the polymer constituting the bottle and label to PET (polyester), separation and liquid density separation by hand and the bottle and label, the complicated separation steps such as wind gravity separation Instead, the ink layer can be separated and removed in alkaline hot water in a state where the bottle and the label are mixed, and then the bottle and the label can be put on the recovery step at the same time and reused.

In addition, since the heat shrinkage ratio of the label attached to the bottle in the bottle circumferential direction is 0.1% or more and less than 80%, the ink layer is caused by the heat shrinkage of the label in the washing process when collecting the used bottle and the label. The interface with and can be peeled off.

Further, the ink layer and the label can be easily separated by an ink removing method of immersing the label in alkaline hot water to separate and remove the intermediate layer and the ink layer which can swell or dissolve in the alkaline hot water on the label. The constituent film can be separated from the constituent film.

Further, the ink layer is removed by an ink removing method of immersing the bottle equipped with the label in alkaline hot water and separating / removing the ink layer and the layer that can swell or dissolve in the alkaline hot water on the label. The label and the bottle that are present can be directly transferred to the PET (polyester) recovery process.

In addition, the label from which the ink layer has been removed by the above-mentioned method is melted together with the bottle in which the label is mounted and recycled, and the label with the ink layer and the bottle are recycled as they are in the recovery step by the method of recycling the labeled bottle. can do.

Further, the regenerated pellets obtained by the above method can be reused for various moldings without containing ink.

[Brief description of drawings]

FIG. 1 Thermoplastic polymer from labeled bottle of the present invention
It is a figure which shows an example of the process of collect | recovering (PET (polyester)) as a pellet.

FIG. 2 is a diagram showing an example of a process of recovering a thermoplastic polymer as pellets from a conventional labeled bottle.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nori Tabota 344 Maebata, Kizu, Inuyama City, Aichi Toyobo Co., Ltd. Inuyama factory (56) Reference JP-A-9-49118 (JP, A) Flat 6-76968 (JP, U) Actual development Flat 5-85624 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B31D 1/02 G09F 3/02 G09F 3/10

Claims (12)

(57) [Claims] 1. A label for a PET bottle, wherein an intermediate layer for removing ink in alkaline hot water is present between an ink layer and a base material layer on at least one surface of a polyester heat shrinkable film . (However, the label 1g is
Cut the bell into 1 cm squares and cut 100 cc of deionized water (2
After stirring for 30 minutes at 5 ° C, pH 6-8), wash with water and dry
When the ink removal rate is less than 5%,
The intermediate layer for removing the ink in the warm water is the label 1
g is cut into 1 cm square and 100 cc of NaOH 3% solution
After stirring in water (90 ° C) for 30 minutes, then washing with water and drying
Ink layer and substrate layer with 90% or more removal rate of ink
Means an intermediate layer existing between and. ) 2. The label according to claim 1, wherein the intermediate layer for removing the ink in the alkaline hot water contains a resin composition capable of swelling or dissolving in the alkaline hot water. 3. A resin composition capable of swelling or dissolving in alkaline hot water is at least one selected from polyester resins, polyacrylic resins, acrylic modified polyester resins, polyurethane resins, acrylic modified polyurethane resins, and polyolefin resins. The label according to any one of claims 1 and 2, comprising: 4. The label according to claim 1, wherein the resin composition capable of swelling or dissolving in alkaline hot water is a polyester resin. 5. The label according to claim 1, wherein the resin composition capable of swelling or dissolving in alkaline hot water is an acrylic modified polyester resin. 6. The heat shrinkage rate of the polyester heat shrinkable film is 30 to 80% ,
The label according to any one of 2 , 3 , 4 , and 5 . 7. A bottle equipped with the label according to any one of claims 1 to 6 . 8. The bottle according to claim 7 , wherein the heat shrinkage rate of the mounting label in the bottle circumferential direction is 0.1% or more and less than 80%. 9. immersing the label according to any one of claims 1 to 6 in an alkaline hot water, swell or dissolve the intermediate layer between the ink layer and the base layer on the label, ink A method for removing ink, which comprises removing the layer from the label. 10. A bottle equipped with the label according to any one of claims 7 and 8 is dipped in alkaline hot water to swell the intermediate layer existing between the ink layer on the label and the substrate layer, or A method for removing ink, which comprises dissolving and removing the ink layer from the label. 11. A method for regenerating a labeled bottle, which comprises melting the label from which the ink layer has been removed by the method according to claim 10 together with the bottle in which the label is mounted and regenerating it. 12. Regenerated pellets obtained by the method of claim 11 .