JP2000200043A - Thermal label and glass bottle with thermal label - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesiveness of a label to a glass bottle and to make it possible to reuse a used glass bottle and the label plural times by successively laminating a printing ink layer and a heat sensitive adhesive layer on the inner surface of a label substrate and situating the printing ink layer within the label substrate. SOLUTION: A printing anchor layer 20 is optionally disposed on one face of a label substrate 10 and a printing ink layer 30, optionally, an adhesion anchor layer 40 and a heat sensitive adhesive layer 50 are successively laminated on the printing anchor layer 20. A coating layer 60 for preventing scuffing is optionally formed on the other face of the label substrate 10 to obtain the objective heat sensitive label 1. It is necessary that the printing ink layer 30 is situated within the label substrate 10 and >=0.1 mm, preferably >=0.5 mm space is left around the layer 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive label and a glass bottle with a heat-sensitive label, and more particularly to a gas bottle which is washed with an alkaline aqueous solution having a concentration of about 4% and a temperature of about 70 to 80.degree. A heat-sensitive label,
The present invention relates to a heat-sensitive label having resistance and alkali resistance, which does not peel off from the glass bottle even when washed with the alkaline aqueous solution and can be reused together with the glass bottle, and a glass bottle to which the heat-sensitive label is attached.

[0002]

2. Description of the Related Art Generally, glass bottles are widely used as containers for beer and soft drinks. Usually, such a glass bottle may be collected after use, washed, refilled with the contents, and sold, so-called a reuse form. In general, such a glass bottle is provided with a label on which a pattern such as a trademark or a design, characters, etc. are printed. After collecting the used glass bottle in the reuse process of the glass bottle, the previous label is peeled and discarded, and a new label is attached when re-shipping.

[0003] In the label mounting with an adhesive, the label is peeled off with the alkaline aqueous solution in a step of collecting the used glass bottle and then cleaning the glass bottle with the alkaline aqueous solution.

[0004] On the other hand, in consideration of the influence of packaging materials on the environment in recent years, it has been desired and studied to reuse the label itself several times together with the glass bottle. in this case,
The conventional label was not used because it was peeled off by an alkaline aqueous solution. Therefore, a label that can withstand such reuse of the glass bottle and the label itself has been required.

[0005] In view of the above, a heat-sensitive label and a glass bottle with the heat-sensitive label which can be used in the above-mentioned applications are presented.
The heat-sensitive label has good adhesiveness to the glass bottle, good adhesiveness to the label substrate itself, and has water resistance and alkali resistance when the glass bottle is washed with an alkaline aqueous solution. There has been a need and demand for a heat-sensitive label which has good use stability without peeling off from the glass bottle and further has improved storage stability of the adhesive of the heat-sensitive label before bonding to the glass bottle.

Further, there has been a demand for a heat-sensitive label which has good adhesiveness to a metal or a synthetic resin such as polyethylene terephthalate, and which adheres well to a plastic bottle such as a dry battery, a metal can, and PET in addition to a glass bottle. .

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems and demands of the prior art, and it is an object of the present invention to provide a glass bottle which has good adhesiveness to a glass bottle and is used. Also, since the label can be reused a plurality of times, even if it is washed with an alkaline aqueous solution at the time of washing the glass bottle, the label base itself is not damaged and it adheres well to the glass bottle, so that it does not fall off or peel off Provides a heat-sensitive label that has good alkali resistance and adheres well to the label itself when the label ends are overlapped,
Another object of the present invention is to provide a glass bottle with a thermosensitive label having alkali resistance using the same.

[0008]

Means for Solving the Problems In order to achieve the above object in the present invention, according to the first aspect of the present invention, a printing ink layer and a heat-sensitive adhesive layer are formed on the inner surface of a label substrate made of a synthetic resin film. A heat-sensitive label, wherein the labels are sequentially laminated, and the printing ink layer is disposed inside an end of the label base material.

According to a second aspect of the present invention, there is provided a label in which a printing ink layer, a metal deposition layer, and a heat-sensitive adhesive layer are sequentially laminated on an inner surface of a label substrate made of a synthetic resin film. The heat-sensitive label is characterized in that the vapor-deposited layer is disposed inside the end of the label substrate.

In the invention according to claim 3, the heat-sensitive adhesive layer comprises an ethylene / (meth) acrylate copolymer, a silane graft modified olefin polymer having no epoxy group, and an epoxy group. The heat-sensitive label according to claim 1, comprising a composition with an olefin polymer having the following formula:

According to a fourth aspect of the present invention, there is provided the heat-sensitive label according to any one of the first to third aspects, wherein the label substrate and the heat-sensitive adhesive layer of the heat-sensitive label are both transparent. .

According to a fifth aspect of the present invention, an adhesive anchor layer is provided between the heat-sensitive adhesive layer and the printing ink layer or the label substrate. It is a heat-sensitive label.

Further, in the invention of claim 6, an adhesive anchor layer is provided between the heat-sensitive adhesive layer and the metal deposition layer or the label substrate.
It is a heat-sensitive label as described.

[0014] In the invention of claim 7, according to claim 1,
7. A glass bottle with a heat-sensitive label, characterized in that the heat-sensitive label according to any one of (6) to (6) is adhered to a part or the entire periphery of the surface of the glass bottle.

[0015]

Embodiments of the present invention will be described below. As shown in the side sectional view of FIG. 1, the heat-sensitive label of the present invention is provided with a printing anchor layer (20) on one side of a label substrate (10) as required, and then a printing ink layer (30) thereon. ), And if necessary, an adhesive anchor layer (4
0), on which a heat-sensitive adhesive layer (50) is sequentially laminated, and the printing ink layer (3) of the label base material (10).
On the side opposite to 0), a coat layer (60) for preventing damage is formed as necessary.

Further, the glass bottle with a heat-sensitive label of the present invention comprises:
As shown in the perspective view of FIG. 3, the thermosensitive label (1) is partially attached to the outside of a glass bottle (70).
The heat-sensitive label (1) is adhered to the outside of the glass bottle (70). The heat-sensitive label-containing glass bottle (7) drops off the heat-sensitive label (1) from the glass bottle (70) even if it is washed with an alkaline aqueous solution. The label (1) itself does not break.

The glass bottle with a heat-sensitive label of the present invention (7)
Shows an example in which the thermal label (1) is attached to a part of the outer periphery of the glass bottle (70). However, the glass bottle including the body or neck of the glass bottle (70) to which the thermal label (1) is adhered. The heat-sensitive label (1) of the present invention can also be attached to most or all of the outer periphery of (70).

Alternatively, as shown in the sectional view of the body of the glass bottle with thermal label (7) in FIG. 4, the glass bottle with thermal label (1) is provided with the thermal label (1) attached all around the outside of the body of the glass bottle (70). 7). The thermal label (1) has one side edge overlapping and bonded to the other side edge. Even if the glass bottle (7) with a heat-sensitive label is washed with an aqueous alkali solution, the heat-sensitive label (1) falls off from the glass bottle (70), the polymerized adhesive portion at the side end is peeled off, or the heat-sensitive label (1) itself is Do not destroy.

The above-mentioned glass bottle (7) with a heat-sensitive label is filled with alcoholic beverages such as beer and sake, or soft drinks such as juice as contents, and is sealed by a sealing means such as a crown and a cap.

The label substrate (10) used in the present invention comprises:
It is made of a synthetic resin film. For example, it is possible to use a single piece of polyester (biaxially stretched polyester film, longitudinally uniaxially stretched heat-shrinkable polyester film), polypropylene, polyamide, polyvinylidene chloride, or the like, or a laminated synthetic resin film. it can. Among these, a biaxially stretched polyester film is preferred from the viewpoints of printability, dimensional stability, transparency and the like. The thickness of the label substrate (10) is not particularly limited, but is usually about 6 μm.
The range is preferably from 100 to 100 μm, and particularly preferably from 25 to 50 μm from the viewpoint of handling.

The heat-sensitive adhesive layer (50) used in the present invention
Labels heat-sensitive adhesives consisting of a composition of ethylene / (meth) acrylate copolymer, silane-grafted modified olefin polymer having no epoxy group, and olefin polymer having epoxy group. It can be formed by extrusion coating on a substrate. The thickness of the heat-sensitive adhesive layer (50) is not particularly limited, but is in a range of about 10 μm to 100 μm,
It is appropriately optimized depending on the material and shape of the glass bottle (70) to be used.

The ethylene / (meth) acrylate copolymer, which is the first component constituting the heat-sensitive adhesive of the heat-sensitive adhesive layer (50), is basically a copolymer of ethylene and (meth) acrylate. It is a copolymer.

As the (meth) acrylate constituting the ethylene / (meth) acrylate copolymer, specifically, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate,
Acrylates such as isobutyl acrylate, sec-butyl acrylate, t-butyl acrylate, n-octyl acrylate and 2-ethylhexyl acrylate; methyl methacrylate, n-propyl methacrylate;
Examples include methacrylates such as n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, and 2-ethylhexyl methacrylate.

The ethylene / (meth) acrylate copolymer of the present invention can be produced by copolymerizing ethylene and (meth) acrylate.

The silane-grafted modified olefin polymer having no epoxy group, which is the second component constituting the heat-sensitive adhesive of the heat-sensitive adhesive layer (50), is, for example, an olefin polymer having no epoxy group. And an unsaturated silane compound and a radical initiator can be produced by melt-kneading at a temperature not lower than the melting point of the olefin polymer and not lower than the decomposition temperature of the radical polymerization initiator using an extruder or the like. In addition, these can also be performed in a reaction liquid.

The olefin polymer used as a raw material of the silane graft polymer of the olefin polymer having no epoxy group includes not only olefin homopolymer but also α, β- such as (meth) acrylate. Copolymerization of olefins with other monomers such as unsaturated carboxylic esters or vinyl esters such as vinyl acetate can be used. Among these, copolymerization of an olefin and an α, β-unsaturated carboxylic acid ester is preferred.

The olefin used here includes, for example, ethylene, propylene, 1-butene, 1-hexene,
Carbon number 2 such as -methyl-1-pentene and 1-octene
To 8 olefins, and these olefins can be used alone or in combination of two or more. In particular, ethylene is preferable among these.

As the silane compound used here, a silane compound having an unsaturated group and a hydrolyzable group can be used. Examples of the unsaturated group in such a silane compound include a vinyl group, an acryloxy group and a methacryloxy group, and examples of the hydrolyzable group include an alkoxy group, an aryloxy group, a substituted alkoxy group, and an alkoxy-substituted alkoxy group. And an acyloxy group. Specific examples of such a compound having an unsaturated group and a hydrolyzable group include vinyl methoxysilane, vinyl triethoxy silane, vinyl tri (β-methoxyethoxy) silane, and vinyl triacetoxy silane. And acrylic silanes such as acryloxypropyltrimethoxysilane and methacryloxypropylmethoxysilane. By using acrylic silanes among these compounds, water resistance and storage stability are improved.

As the olefin polymer having an epoxy group, which is the third component constituting the heat-sensitive adhesive of the heat-sensitive adhesive layer (50), ethylene-glycidyl acrylate polymer, ethylene-glycidyl methacrylate copolymer, Ethylene-vinyl acetate-glycidyl acrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate copolymer, ethylene-ethyl acrylate-glycidyl methacrylate copolymer, ethylene-acrylic acid n-
Glycidyl methacrylate graft products of a butyl-glycidyl methacrylate copolymer and an ethylene-ethyl acrylate copolymer can be exemplified. Among these, from the viewpoint of thermal stability, a copolymer composed of an olefin and a glycidyl ester and a copolymer composed of an olefin, a (meth) acrylate and a glycidyl ester are particularly preferable.

The heat-sensitive adhesive layer (50) used in the present invention
Is kneaded by a known melt extrusion coating method, and directly onto the printing ink layer (30) or a resin such as polyethyleneimine, polybutadiene, isocyanate, polyester, or ethylene acrylic acid copolymer as an adhesive anchor layer (40). It can be easily laminated by extrusion coating. This adhesive anchor layer (40)
The adhesiveness between the heat-sensitive adhesive layer (50) and the printing ink layer (30) or the label substrate (10) is improved.

Since the heat-sensitive adhesive used in the heat-sensitive label (1) of the present invention has the above-mentioned constitution, it has good adhesiveness and storage stability. Further, the heat-sensitive adhesive of the heat-sensitive label of the present invention is used for modifying the silane graft to an olefin polymer having no epoxy group. Can be adjusted independently of the above, so that the cost of the adhesive can be reduced.

As shown in FIG. 1, the heat-sensitive label (1) of the present invention has a label substrate (1) on the surface of a label substrate (10).
A coat layer (60) can be provided for the purpose of surface protection such as prevention of contamination and damage of the surface of 0).

As the coating layer (60), a silicone-based coating, which is a resin layer composed of polyorganosiloxane containing silicon oxide particles or a hydrolyzate of a coupling agent having an epoxy group and colloidal silica, or a polyfunctional acrylic resin is used. It is also possible to laminate an acrylic coat or the like, which is a resin obtained by blending an acid ester with the prepolymer and curing it with ultraviolet rays or electron beams.

On the printing surface (inner surface) of the label substrate (10), a flame treatment, a blast treatment, a corona treatment, a plasma treatment, or the like is performed in advance in order to increase the adhesiveness between the printing ink layer (30) and the label substrate (10). A surface treatment such as a treatment, or as shown in FIG. 2, an in-line printing anchor coat layer (20) to be coated at the time of film formation in order to further improve the adhesiveness with the printing ink layer (30). An easy-adhesion layer can also be provided by multilayer coextrusion.

The printing ink layer (30) constituting the thermal label (1) of the present invention is generally provided on the inner surface of the label substrate (10), but is provided on the surface of the label substrate (10). It is also possible. The printing ink layer (30)
As shown in FIG. 2, it is a necessary condition that the label substrate (10) is disposed inside from the end thereof, and 0.1 mm or more from the end of the label substrate (10). 5
mm or more inside, and the label is arranged so as to be surrounded by a solid layer without the printing ink layer (30) or the metal deposition layer (22).

The printing ink layer (30) can be provided on the entire surface of the label substrate (10) except for the solid layer at the end, or can be provided partially. In the present invention, when both the label substrate (10) and the heat-sensitive adhesive layer (50) are transparent, the printing ink layer (30) is partially provided to form the printing ink layer (30). It is possible to obtain a visual effect in which characters, designs, etc. appearing on the glass bottle appear to rise.

The printing ink layer (30) constituting the thermal label (1) of the present invention comprises a binder (resin), an organic or inorganic pigment, and various additives (for example, an antioxidant, a leveling agent, an ultraviolet absorber). , Heat resistance improvers, lubricants, etc.) and solvents (mainly organic solvents, water, etc.). Considering the alkali resistance, at least pooriol, a diisocyanate and a chain extender react as a printing ink material. It is preferable to use a binder containing a urethane-based resin obtained by the above method. Further, in order to increase the coating film resistance of the printing ink layer (30), a two-pack curing reaction type ink layer to which a curing agent is added may be used. In particular, the white solid ink layer provided on the outermost layer overprinted with the coloring ink is preferably of a two-part curing type containing a curing agent.

In the present invention, as shown in FIG. 2, a metal deposition layer (22) may be provided on the surface of the printing ink layer (30), and the metal deposition layer (22) may be a metal represented by aluminum. It is a layer having a thickness of about 30 nm to 80 nm, and can be easily formed by a known vacuum evaporation method or a sputtering method, and the method is not particularly limited.

The metal deposition layer (22) can be formed by patterning by partially removing the metal deposition layer as necessary. In forming the deposition layer (22), a known deposition anchor layer can be formed as necessary. Further, a known transparent varnish can be formed on the metal deposition layer (22) in order to maintain glossiness.

In the present invention, the metal deposition layer (22) is disposed between the printing ink layer (30) and the heat-sensitive adhesive layer (50), and as described above, from the end of the label substrate (10). It is meaningful to arrange inside, and the adhesive anchor layer (40), the print anchor layer (20) and the coat layer (60)
It is also within the scope of the present invention that the layer configuration changes due to the addition of.

[0041]

Next, the present invention will be described in detail with reference to examples. <Example 1> Biaxially stretched polyester film (thickness 38)
(μm) on a label base material with a corona-treated surface, a 0.5 mm inner side of the end of the label is provided with a white printing ink layer using gravure ink (trade name: NewLp Super, manufactured by Toyo Ink Manufacturing Co., Ltd.). Was. Next, a polyethyleneimine-based adhesive anchor layer was provided on the label substrate and the printing ink layer, and a heat-sensitive adhesive layer was provided on the adhesive anchor layer. The adhesive constituting the heat-sensitive adhesive layer includes an ethylene ethyl acrylate copolymer, a silane graft modified product obtained by kneading γ-methacryloxypropyl trimethoxysilane with the ethylene ethyl acrylate copolymer, and ethylene-glycidyl methacrylate- This is a composition obtained by kneading a vinyl acetate terpolymer. The adhesive layer was formed by extruding and coating 30 μm of the adhesive on the label substrate and the printing ink layer.

In this way, a heat-sensitive label raw material having the above-described structure is prepared, and the raw material is slit into a 50 mm width and adhered to the body of a glass bottle at 140 ° C. by a commercially available heat-sensitive labeling labeler. An attached glass bottle was obtained.

The thus-obtained glass bottle with a heat-sensitive label was evaluated for its appearance by the following cycle test and the adhesion between the glass bottle and the heat-sensitive label was evaluated. The results are shown in Table 1. All the adhesive strengths were measured according to JIS K6256. The number of samples at this time was set to 10. [20 minutes after alkali immersion → 80 ° C water wash cycle test]
After the glass bottle to which the thermal label is adhered is immersed in a 4% aqueous solution of sodium hydroxide (80 ° C.) for 20 minutes, the washing process at 80 ° C. is repeated 5 times. Was measured for adhesive strength.

Example 2 After printing in the same manner as in Example 1, a polyester resin was formed as a deposition anchor,
Then, an aluminum vapor-deposited layer having a thickness of 60 nm was formed 1 mm inward from the end of the label by a vacuum vapor deposition method. Next, the aluminum vapor deposition layer was patterned by celite processing.

An adhesive anchor layer and a heat-sensitive adhesive layer were formed in the same manner as in Example 1 to prepare a label substrate, and the same test as in Example 1 was conducted. The results are shown in Table 1.

<Comparative Example 1> Example 1 was repeated except that the label was formed such that the printing ink layer was formed up to the end of the label base material.
A glass bottle with a heat-sensitive label was obtained in the same manner as described above, and a test was conducted in the same manner. The results are shown in Table 1.

<Comparative Example 2> A glass bottle with a heat-sensitive label was obtained in the same manner as in Example 2 except that the label structure was such that the printing ink layer and the aluminum vapor-deposited layer were formed up to the end of the label base material. The test was performed, and the results are shown in Table 1.

[0048]

[Table 1]

[Table 1] [1 hour after bonding] In each of Examples 1 and 2, there was no change in the heat-sensitive label with no appearance, displacement, or floatation of the heat-sensitive label. 19
It was 00 g / 10 mm and 1300-2100 g / 10 mm, and there was no problem in use as a glass bottle with a heat-sensitive label.

[State of 20 hours after bonding] The heat-sensitive labels of Examples 1 and 2 had no change in appearance, displacement, or floatation, had no change at all, and had an adhesive strength of 12
00 ~ 1600g / 10mm 、 1100 ~ 1500g /
It was 10 mm, and the maximum adhesive strength was lower than the state one hour after bonding, but there was no problem in use as a glass bottle with a heat-sensitive label.

[20 minutes after alkali immersion → 80C washing cycle test] As shown in Table 1, none of the heat-sensitive labels of Examples 1 and 2 had any appearance, displacement, floating, etc. It had sufficient strength and had no problem in use as a glass bottle with a heat-sensitive label.

On the other hand, as can be seen from Table 1, in both Comparative Examples 1 and 2, the end of the heat-sensitive label tended to float and peel off as the number of cycles in the cycle test increased.

[0053]

As described above, the present invention has the following effects. That is, a heat-sensitive label in which a printing ink layer and a heat-sensitive adhesive layer are sequentially laminated on the inner surface of a label base made of a synthetic resin film, and the heat-sensitive label in which the ink layer is arranged inside the end of the label base is used. The glass bottle with a heat-sensitive label adhered to the glass bottle has good adhesion with the glass bottle, and also has good adhesion with the label substrate itself,
Also, even when cleaning the glass bottle with an alkaline aqueous solution,
Water-resistant and alkali-resistant to alkaline water penetrated from the edge of the label, has good use stability without peeling off from the glass bottle, and bonding of heat-sensitive label before bonding to the glass bottle The storage stability of the agent is improved.

A label in which a printing ink layer, a metal-deposited layer, and a heat-sensitive adhesive layer are sequentially laminated on the inner surface of a label substrate made of a synthetic resin film. Since the thermal label is disposed on the inner side, the image of the printing ink layer exhibits metallic luster together with the above-described effects, and can be a thermal label that contributes to the improvement of the design effect.

Further, since the adhesive forming the heat-sensitive adhesive layer is obtained by modifying the silane graft to an olefin polymer having no epoxy group, the amount of silane in the adhesive composition can be reduced by using an expensive epoxy group. Since it can be adjusted independently of the olefin polymer to have, the cost of the adhesive can be reduced.

Accordingly, the present invention exhibits excellent practical effects in applications such as labels for beer and soft drinks.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a thermal label of the present invention in a side cross section.

FIG. 2 is an explanatory view showing another embodiment of the thermal label of the present invention in a side cross section.

FIG. 3 is a perspective view illustrating an embodiment of the glass bottle with a heat-sensitive label of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the glass bottle with a heat-sensitive label of the present invention in a body section.

[Explanation of symbols]

 1 Thermal Label 7 Glass Bottle with Thermal Label 10 Label Base 20 Print Anchor Layer 22 Metal Deposition Layer 30 Printing Ink Layer 40 Adhesive Anchor Layer 50 Thermal Adhesive Layer 60 ‥‥ Coat layer 70 ‥‥ Glass bottle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayoshi Suzuda 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Masao Nakajima 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Kazuhiro Kubota 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. F-term (reference) 3E062 AA09 AB02 AC06 DA07 DA09

Claims (7)

[Claims] 1. A label in which a printing ink layer and a heat-sensitive adhesive layer are sequentially laminated on the inner surface of a label substrate made of a synthetic resin film, wherein the printing ink layer is arranged inside an end of the label substrate. A heat-sensitive label characterized by the fact that: 2. A label in which a printing ink layer, a metal-deposited layer, and a heat-sensitive adhesive layer are sequentially laminated on the inner surface of a label substrate made of a synthetic resin film, wherein the printing ink layer and the metal-deposited layer correspond to the label substrate. A heat-sensitive label, which is located inside the end. 3. The heat-sensitive adhesive layer according to claim 1, wherein said heat-sensitive adhesive layer comprises ethylene.
3. The composition according to claim 1, comprising a composition of an acrylate copolymer, a silane graft modified olefin polymer having no epoxy group, and an olefin polymer having an epoxy group. 4. Thermal label. 4. The heat-sensitive label according to claim 1, wherein both the label base material and the heat-sensitive adhesive layer of the heat-sensitive label are transparent. 5. The heat-sensitive label according to claim 1, wherein an adhesive anchor layer is provided between the heat-sensitive adhesive layer and the printing ink layer or the label substrate. 6. The heat-sensitive label according to claim 2, wherein an adhesive anchor layer is provided between the heat-sensitive adhesive layer and the metal deposition layer or the label substrate. 7. A glass bottle with a heat-sensitive label, wherein the heat-sensitive label according to any one of claims 1 to 6 is adhered to a part or the entire circumference of the surface of the glass bottle.