JPH07219439A - Easy-to-peel heat-sensitive adhesive label - Google Patents

Abstract

(57) [Summary] [Purpose] In recent years, in connection with the problem of waste treatment related to the global environment, there is an increasing movement to peel off labels from glass bottles and reuse glass bottles, cans and plastic molded products. The heat-sensitive adhesive label is easy to peel off from glass bottles etc. in the normal bottle washing process with warm water or steam, etc., without peeling off during distribution, handling at the time of sale or immersion in normal temperature water. It has been requested. According to the present invention, a first heat-sensitive adhesive component comprising a polymeric material, a tackifier having a softening point of 100 ° C. or more and a solid plasticizer, and a polymeric material on the back surface of a label substrate (10). And a second heat-sensitive adhesive component composed of a tackifier having a softening point of less than 100 ° C. and a solid plasticizer, and a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent. Was added,
The heat-sensitive adhesive label provided with the heat-sensitive adhesive layer (20) is easily peeled off.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is a heat-sensitive adhesive label to be attached to a glass bottle, a can container, a plastic molded article, etc., which does not peel off when it is distributed, handled at the time of sale, or immersed in normal temperature water. The present invention relates to a heat-sensitive adhesive label that can be easily peeled off from a glass bottle or the like in a normal bottle washing process using warm water or steam.

[0002]

2. Description of the Related Art Conventionally, a heat-sensitive adhesive label to be attached to a glass bottle, a can container, a plastic molded product, etc.
Basically composed of polymer material, tackifier and solid plasticizer, it is not sticky at room temperature, but it becomes sticky by heating and stickiness lasts for a considerable time after cooling. A heat-sensitive adhesive label having a heat-sensitive adhesive layer (20) commonly called a tack type (industry term) provided on the back surface of the label substrate (10) is widely used. Regarding the heat-sensitive adhesive label provided with the heat-sensitive adhesive layer (20), it is firmly adhered to a glass bottle, a can container, a plastic molded product, etc., and usually it is difficult to peel it from a glass bottle or the like. It was a thing.

[0003]

In connection with the recent problem of waste disposal related to the global environment, there is an increasing movement to peel labels from glass bottles and reuse glass bottles, can containers and plastic molded products. The heat-sensitive adhesive label is easy to peel off from glass bottles etc. in the normal bottle washing process with warm water or steam, etc., without peeling off during distribution, handling at the time of sale or immersion in normal temperature water. It has been requested.

[0004]

Means for Solving the Problems In response to the above demands, the present invention basically provides a polymer on the back surface (lower surface in FIG. 1) of a label substrate (10) as shown in FIG. By comprising a material, a tackifier, and a solid plasticizer, a microcapsule-shaped thermal expansion agent (21) and a crosslinking reaction type curing agent were added, and by providing a heat-sensitive adhesive layer (20) The present invention provides a heat-sensitive adhesive label that can be easily peeled off from a glass bottle or the like in a normal bottle washing process using warm water or steam without peeling off during distribution, handling at the time of sale or immersion in normal temperature water.

The present invention also relates to the heat-sensitive adhesive layer shown in FIG.
(20) a first heat-sensitive adhesive component consisting of a polymeric material, a tackifier having a softening point of 100 ° C. or higher and a solid plasticizer, and a polymeric material and a tackifier having a softening point of less than 100 ° C. A second heat-sensitive adhesive component consisting of a solid plasticizer, and peeling resistance during distribution, handling at the time of sale, immersion in normal temperature water, and normal washing bottles with hot water or steam. It is intended to provide a heat-sensitive adhesive label which has improved bottle washing property in the process and is easily peeled from a glass bottle or the like.

The label substrate (10) in the heat-sensitive adhesive label of the present invention which is easy to peel off is the same as the conventional one, and has a thickness 1 with an appropriate printed pattern layer (11) provided on the surface.
A paper base material, a resin film base material, a synthetic paper base material, a metal foil base material, or a laminated base material thereof having a thickness of about 0 to 200 μm can be used without particular limitation.

Regarding the polymer material which basically constitutes the heat-sensitive adhesive layer (20) in the heat-sensitive adhesive label of the present invention which can be easily peeled off, a component which gives an adhesive force to the heat-sensitive adhesive layer (20) Therefore, polyvinyl acetate type, copolyethylene-vinyl acetate type, polyacrylic acid ester type, polyvinyl chloride type, natural rubber type, synthetic rubber type, copolyvinyl acetate-acrylic acid ester type, polyester type, polyurethane type, etc. The polymer material can be suitably used as in the prior art.

Further, regarding the tackifier of the present invention which basically constitutes the heat-sensitive adhesive layer (20), when the heat-sensitive adhesive label is heated to activate the heat-sensitive adhesive layer (20), A component for enhancing the adhesiveness of the heat-sensitive adhesive layer (20), which is a rosin derivative resin system, a terpene resin system, a phenol resin system,
A tackifier such as a xylene resin can be preferably used as in the conventional case.

Further, the solid plasticizer basically constituting the heat-sensitive adhesive layer (20) of the present invention is heated to a temperature equal to or higher than the melting point and melted to swell the polymer material and the tackifier. The heat-sensitive adhesive is a component which is melted to give tackiness and adhesiveness to the heat-sensitive adhesive layer (20), and the melted solid plasticizer does not easily crystallize even after cooling. layer
(20) is a component that retains its tackiness and adhesive strength for a considerable period of time, and includes diphenyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dihydroabietyl phthalate, dimethyl isophthalate, sucrose benzoate, and dibenzoic acid. Ethylene glycol, trimethylolethane tribenzoate,
Solid plasticizers such as tribenzoic acid glyceride, tetrabenzoic acid pentaerytate, sucrose octaacetate, tricyclohexyl citrate, and N-cyclohexyl-P-toluenesulfonamide can be preferably used as in the conventional case.

There are no particular restrictions on the microencapsulated heat-expanding agent (21) in the heat-sensitive adhesive label of the present invention which can be easily peeled off, and glass, silica, silane, carbon, vinylidene chloride, vinylidene chloride-acrylonitrile can be used. Copolymer, vinyl acetate-acrylonitrile copolymer,
Methyl methacrylate-acrylonitrile copolymer, alumina, zirconia, etc. are used as shell walls, and low boiling point hydrocarbons or sodium bicarbonate, azobisisobutyronitrile, ammonium carbonate, etc. are included.
A general microcapsule-shaped heat-expanding agent (21) having an expansion starting temperature of about 80 to 100 ° C. at about m is added to the above-mentioned heat-sensitive adhesive layer (20) at 0.03 to 20% by weight. It is used.

Regarding the crosslinking reaction type curing agent in the heat-sensitive adhesive label of the present invention which can be easily peeled off, an appropriate crosslinking reaction type curing agent having two or more epoxy groups or two or more isocyanate groups is used. The heat-sensitive adhesive layer described above (20)
This heat-sensitive adhesive layer (20) to improve the water resistance of
In addition, 0.3 to 20% by weight is added. That is, the heat-sensitive adhesive label is heated to heat-sensitive adhesive layer
When (20) is activated, this crosslinking reaction type curing agent reacts with the hydroxyl group or carboxyl group in the heat-sensitive adhesive layer (20) to improve water resistance, and as a result, the label substrate (10 ) And the adhesive force with.

Further, the heat-sensitive adhesive layer (20) described above contains
If necessary, antiseptics, dispersants, defoaming agents, etc. can be added.

In the heat-sensitive adhesive label of the present invention, which is easy to peel off, the thermosensitive adhesive layer (20) comprises a polymer material, a tackifier having a softening point of 100 ° C. or higher, and a solid plasticizer. Regarding the first heat-sensitive adhesive component, since the internal cohesive force of the heat-sensitive adhesive layer (20) is strong when the softening point of the tackifier is relatively high, the heat-sensitive adhesive from the surface of a glass bottle or the like. The layer (20) is peeled off without causing cohesive failure and improves the bottle washing property in a normal bottle washing process with hot water, steam or the like (see the bottle washing stain property in Table 1), which will be described later. It is preferable that 50 to 90 parts by weight of the first heat-sensitive adhesive component is mixed with the second heat-sensitive adhesive component to form the heat-sensitive adhesive layer (20). It should be noted that if 90 parts by weight or more of the first heat-sensitive adhesive component is blended, the adhesive force between the heat-sensitive adhesive layer (20) and the glass bottle or the like may be reduced, so caution is required.

Further, in the heat-sensitive adhesive label of the present invention which is easily peeled off, the thermosensitive adhesive layer (20) is composed of a polymer material, a tackifier having a softening point of less than 100 ° C. and a solid plasticizer. Regarding the second heat-sensitive adhesive component, when the softening point of the tackifier is relatively low, the heat-sensitive adhesive layer (20) is soft, so that the heat-sensitive adhesive layer (20) and the glass bottle etc. The adhesive force (contact area) is increased to improve the peeling resistance (refer to the adhesive force measurement in Table 1) in distribution, handling at the time of sale, etc., and the first heat-sensitive adhesive component described above. On the other hand, it is preferable that 10 to 50 parts by weight of this second heat-sensitive adhesive component is blended to form the heat-sensitive adhesive layer (20). It should be noted that if the second heat-sensitive adhesive component is blended in an amount of 50 parts by weight or more, the heat-sensitive adhesive layer (20) may be cohesively destroyed and remain on the surface of a glass bottle or the like, so caution is required.

[0015]

In the easily peelable heat-sensitive adhesive label of the present invention, when the heat-sensitive adhesive layer (20) is activated by heating the heat-sensitive adhesive label at, for example, about 100 ° C. for several seconds, the above-mentioned high-sensitive adhesive label is produced. By the action of a molecular material, a tackifier, a solid plasticizer and a cross-linking type curing agent, the heat-sensitive adhesive layer (20) is provided with tackiness and strong adhesion,
In addition, even after cooling, since the molten solid plasticizer does not crystallize easily, the tackiness and strong adhesive force of the heat-sensitive adhesive layer (20) are maintained for a considerable time, and the microcapsules described later are used. The heat-expanding agent (21) is in a state of slightly expanding after being heated for a short period of time, and it is adhered to the surface of a glass bottle or the like and appropriately pressurized to firmly adhere it to a glass bottle, can container, plastic molded product, etc. It can be worn.

Further, in the heat-sensitive adhesive label of the present invention, which can be easily peeled off, as shown in FIG. 2, in a normal bottle washing step with hot water or steam of about 80 ° C., a glass bottle (4
When the heat-sensitive adhesive label attached to (0) is heated, and the heat-sensitive adhesive layer (20) that becomes sticky when heated is softened (see FIG. 2 (A)), the heat-sensitive adhesive label Thermal expansion of the microcapsule-shaped thermal expansion agent (21) added to the agent layer (20)
(See FIG. 2B), the heat-sensitive adhesive layer (2
Unevenness on the surface (22) that is attached to the glass bottle (40) (0) (Fig.
Occurs, the adhesive strength (contact area) of the bonding surface (22) with the glass bottle (40) is reduced, and the microcapsule shape added to the heat-sensitive adhesive layer (20) Thermal expansion agent
The heat-sensitive adhesive label is curled (see FIG. 2 (D)) due to the difference in thermal expansion between the label substrate (10) and the heat-sensitive adhesive layer (20) due to thermal expansion of (21). And the heat-sensitive adhesive label attached to the glass bottle (40) is
It is easily peeled off from (40).

That is, in the easily peelable heat-sensitive adhesive label of the present invention, the back side of the label substrate (10) basically comprises a polymeric material, a tackifier and a solid plasticizer,
By providing a heat-sensitive adhesive layer (20) containing a microcapsule-shaped thermal expansion agent (21) and a cross-linking type curing agent, it is possible to handle the product at the time of distribution, sale, immersion in normal temperature water, etc. It is possible to obtain a heat-sensitive adhesive label which can be easily peeled from a glass bottle or the like by a normal bottle washing process with warm water or steam without peeling.

[0018]

EXAMPLE FIG. 1 is a partial sectional view of a heat-sensitive adhesive label which can be easily peeled off in Example 1, Example 2, Example 3 and Comparative Example 3 of the present invention. That is, on the back surface of the label substrate (10) provided with an appropriate printed pattern layer (11) on the front surface, a microcapsule-like heat is basically formed by a polymeric material, a tackifier and a solid plasticizer. 1 shows a state of a heat-sensitive adhesive label which is provided with a heat-sensitive adhesive layer (20) containing a swelling agent (21) and a cross-linking type curing agent and which can be easily peeled off.

The first heat-sensitive adhesive component constituting the heat-sensitive adhesive layer (20) in Examples 1, 2 and 3 of the present invention is ethylene-based as a polymer material.
100 solid parts by weight of an aqueous emulsion of vinyl acetate copolymer, 100 solid parts by weight of an aqueous emulsion of a rosin derivative ester having a softening point of 120 ° C as a tackifier, and a solid plasticizer And 100 solid parts by weight of an aqueous emulsion of dicyclohexyl phthalate (melting point 64 ° C.). further,
Regarding the second heat-sensitive adhesive component constituting the heat-sensitive adhesive layer (20) in Example 2, Example 3, and Comparative Example 3 of the present invention, the polymer material is ethylene-vinyl acetate copolymer. 100 parts by weight of aqueous emulsion and softening point of 1
100 parts by weight of an aqueous emulsion of a rosin derivative ester having a softening point of 85 ° C. as a tackifier of less than 00 ° C., and dicyclohexyl phthalate as a solid plasticizer.
100 parts by weight of an aqueous emulsion (melting point 64 ° C.) is blended.

<Example 1> As the polymer material, ethylene was used.
100 parts by weight of an aqueous emulsion of vinyl acetate copolymer and a rosin derivative ester as a tackifier
100 parts by weight of an aqueous emulsion having a softening point of 120 ° C. and dicyclohexyl phthalate as a solid plasticizer.
100 solid parts by weight of an aqueous emulsion having a melting point of 64 ° C., and 300 solid parts by weight of the same heat-sensitive adhesive as the first heat-sensitive adhesive component composed of vinylidene chloride-acrylonitrile copolymer as a shell wall. , Encapsulating isobutane, average particle size 10 ~ 20μm, expansion start temperature 80 ℃
And 9 parts by weight of the microcapsule-shaped thermal expansion agent (21),
6 parts by weight of a liquid crosslinking reaction type curing agent of a bisphenol A epoxy compound having two epoxy groups,
Was added to prepare a heat-sensitive adhesive layer composition in the form of an aqueous resin dispersion (aqueous emulsion) having a solid content of 50% by weight.

Subsequently, as shown in FIG. 1, a polyester having a thickness of 25 μm and provided with an appropriate printed pattern layer (11) on the surface thereof.
This heat-sensitive adhesive layer composition is applied to the back surface of the (PET) film substrate (10) by a roll coating method, and the temperature is kept at 45 ° C. for 2 hours.
The heat-sensitive adhesive label of Example 1 was prepared by drying for a minute and having a heat-sensitive adhesive layer (20) having a layer thickness of 25 μm provided thereon.

Example 2 Polymer material and softening point of 100
From 80 solid parts by weight of the above-mentioned first heat-sensitive adhesive component consisting of a tackifier having a temperature of ℃ or more and a solid plasticizer, a polymeric material, a tackifier having a softening point of less than 100 ° C. and a solid plasticizer. In the same manner as in Example 1, the vinylidene chloride-acrylonitrile copolymer was added to 100 solid parts by weight of the heat-sensitive adhesive composed by mixing 20 solid parts by weight of the above-mentioned second heat-sensitive adhesive component. Isobutane was included as a shell wall, the average particle size was 10 to 20 μm, and the expansion start temperature was 80 ° C.
3 parts by weight of the microcapsule-shaped thermal expansion agent (21),
2 parts by weight of a liquid crosslinking reaction type curing agent of a bisphenol A epoxy compound having two epoxy groups,
Was added to prepare a heat-sensitive adhesive layer composition in the form of an aqueous resin dispersion (aqueous emulsion) having a solid content of 50% by weight.

Subsequently, as shown in FIG. 1, a thickness of 25 μm, which is the same as that of Example 1, having an appropriate printed pattern layer (11) provided on the surface.
This heat-sensitive adhesive layer composition is applied to the back surface of the m-thick polyester film substrate (10) by a roll coating method and dried at 45 ° C. for 2 minutes to give a heat-sensitive adhesive layer (20 μm) having a layer thickness of 25 μm. ) Is provided to prepare a heat-sensitive adhesive label of Example 2 which is easily peeled off.

Comparative Example 1 The heat-sensitive adhesive layer composition of Example 2, that is, the microcapsule-shaped thermal expansion agent (21) and the crosslinking reaction type curing agent were not added, that is, the polymer material. 80 solid parts by weight of the above-mentioned first heat-sensitive adhesive component consisting of a tackifier having a softening point of 100 ° C. or higher and a solid plasticizer, a polymer material, a tackifier having a softening point of less than 100 ° C. and a solid An aqueous resin dispersion having a solid content of 50% by weight of 100 solid parts by weight of a heat-sensitive adhesive composed of a plasticizer and 20 solid parts by weight of the above-mentioned second heat-sensitive adhesive component. An aqueous emulsion) -like heat-sensitive adhesive layer composition was prepared.

Then, in the same manner as in Example 2, the back surface of the polyester film substrate (10) having a thickness of 25 μm and provided with an appropriate printed pattern layer (11) on the surface was subjected to a roll coating method.
This heat-sensitive adhesive layer composition was applied and dried at 45 ° C. for 2 minutes to provide a heat-sensitive adhesive layer (20) having a layer thickness of 25 μm.
The heat-sensitive adhesive label of Comparative Example 1 which is easily peeled off is produced.

Comparative Example 2 The heat-sensitive adhesive layer composition of Example 2 containing no crosslinking reaction type curing agent, that is, a polymeric material, a tackifier having a softening point of 100 ° C. or more, and a solid. The second heat-sensitive adhesive component, which comprises a plasticizer, 80 solid parts by weight of the first heat-sensitive adhesive component, a polymeric material, a tackifier having a softening point of less than 100 ° C., and a solid plasticizer.
20 solid parts by weight of the heat-sensitive adhesive component, and 100 solid parts by weight of the heat-sensitive adhesive formed by blending, with vinylidene chloride-acrylonitrile copolymer as a shell wall, isobutane was included, and an average particle size. Of 10 to 20 μm and an expansion starting temperature of 80 ° C., 3 parts by weight of a microcapsule-shaped heat-expanding agent (21) was added to the mixture to obtain a heat-sensitivity in the form of an aqueous resin dispersion (aqueous emulsion) having a solid content of 50 wt%. An adhesive layer composition was prepared.

Then, similarly to Example 2 and Comparative Example 1, the back surface of the polyester film substrate (10) having a thickness of 25 μm and having an appropriate printed pattern layer (11) provided on the surface was subjected to a roll coating method. , Apply this heat-sensitive adhesive layer composition at 45 ° C.
After drying for 2 minutes, the heat-sensitive adhesive layer (20) with a layer thickness of 25 μm
The heat-sensitive adhesive label of Comparative Example 2 provided with is prepared.

Example 3 Polymer material and softening point of 100
60 parts by weight of the above-mentioned first heat-sensitive adhesive component consisting of a tackifier having a temperature of ℃ or more and a solid plasticizer, a polymer material, a tackifier having a softening point of less than 100 ° C. and a solid plasticizer. In the same manner as in Examples 1 and 2, vinylidene chloride was added to 100 solid parts by weight of the heat sensitive adhesive composed by mixing 40 solid parts by weight of the above-mentioned second heat sensitive adhesive component.
3 parts by weight of a microcapsule-shaped thermal expansion agent (21) having an acrylonitrile copolymer as a shell wall and isobutane encapsulated therein, having an average particle size of 10 to 20 μm and an expansion start temperature of 80 ° C. By adding 2 parts by weight of a liquid crosslinking reaction type curing agent of a bisphenol A epoxy compound having an epoxy group, a heat-sensitive adhesive in the form of an aqueous resin dispersion (aqueous emulsion) having a solid content of 50% by weight. An agent layer composition was prepared.

Subsequently, as shown in FIG. 1, the back surface of the polyester film base material (10) having a thickness of 25 μm, which is the same as in Examples 1 and 2, having an appropriate printed pattern layer (11) provided on the surface. Was coated with this heat-sensitive adhesive layer composition by a roll coating method and dried at 45 ° C. for 2 minutes to provide a heat-sensitive adhesive layer (20) having a layer thickness of 25 μm. This is an easily prepared heat-sensitive adhesive label.

Comparative Example 3 A heat-sensitive adhesive which does not contain the above-mentioned first heat-sensitive adhesive component, that is, a polymer material, a tackifier having a softening point of less than 100 ° C. and a solid plasticizer. In 100 parts by weight of the heat-sensitive adhesive composed of the above-mentioned second heat-sensitive adhesive component, Example 1, Example 2,
In the same manner as in Example 3, vinylidene chloride-acrylonitrile copolymer was used as a shell wall, isobutane was included therein, the average particle size was 10 to 20 μm, and the expansion start temperature was 80 ° C. A microcapsule-shaped thermal expansion agent (21 ) And 2 parts by weight of a liquid crosslinking reaction type curing agent of a bisphenol A-based epoxy compound having two epoxy groups are added, and an aqueous resin dispersion having a solid content of 50% by weight is added. A heat-sensitive adhesive layer composition in the form of a body (aqueous emulsion) was prepared.

Subsequently, as shown in FIG. 1, Examples 1, 2 and 3 in which an appropriate printed pattern layer (11) was provided on the surface
Polyester film substrate with the same thickness as 25μm (10)
This heat-sensitive adhesive layer composition is applied to the back surface of the above by a roll coating method and dried at 45 ° C. for 2 minutes to give a layer thickness of 25
The heat-sensitive adhesive label of Comparative Example 3 provided with a heat-sensitive adhesive layer (20) having a thickness of μm was prepared.

<Bottle Washing Test> The heat-sensitive adhesive labels of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Example 3, and Comparative Example 3 which are easily peeled off are cut into 50 × 100 mm. After heating at 120 ° C. for 20 seconds to give the heat-sensitive adhesive layer (20) an adhesive property and an adhesive force, 2 kg of the usual 2 kg was applied to the surface of the transparent glass plate.
A pressure of / cm ^{2 was applied} , and the test pieces were adhered to prepare 50 test pieces for the bottle washing test.

Then, tap water heated to 60 ° C. and 80
Ten pieces of each test piece were immersed in tap water heated to ℃ and 3% caustic soda water heated to 80 ℃,
It measures the time (minutes) until the heat-sensitive adhesive label self-peeles in a stationary state without applying external force such as rubbing, and considers the conditions of normal bottle washing process with hot water or steam. And passed self-peeling time of 10 minutes or less (○)
It is what Table 1 shows the results of the bottle washing test of Example 1, Example 2, Comparative Example 1, Comparative Example 2, Example 3, and Comparative Example 3.

[0034]

[Table 1]

Regarding the bottle-washing contamination in the table, in consideration of the situation of the normal bottle-washing process with hot water or steam,
Passed when no residual heat-sensitive adhesive layer (20) was observed on the surface of the transparent glass plate when the heat-sensitive adhesive label self-peeled in a stationary state without applying external force such as rubbing.
(○). Regarding the peel resistance in the table, 5 pieces of each test piece were immersed in normal temperature water at the time of sale or at home for handling, and allowed to stand for 48 hours to remove the heat-sensitive adhesive label. If you can't see
It is a pass (○). Furthermore, regarding the adhesive strength measurement in the table, in consideration of handling at the time of distribution and sale, the heat-sensitive adhesive of 5 pieces of each test piece that was pressed and stuck for 24 hours as described above was used. The adhesive strength between the layer (20) and the transparent glass plate was measured according to JIS-Z-0237,
The adhesive strength of 800 g / 25 mm or more was passed (○).

[0036]

As described above, in the action and examples, in the easily peelable heat-sensitive adhesive label of the present invention, the backside of the label substrate (10) basically comprises a polymer material and a tackifier. By providing a heat-sensitive adhesive layer (20), which is composed of a solid plasticizer and a microcapsule-shaped thermal expansion agent (21) and a cross-linking reaction type curing agent, it is possible to distribute and sell it. It is possible to provide a heat-sensitive adhesive label that can be easily peeled from a glass bottle or the like in a normal bottle washing process using warm water or steam, without being peeled off by handling or immersion in normal temperature water.

That is, in the heat-sensitive adhesive label of the present invention which can be easily peeled off, the heat-sensitive adhesive label is, for example, 100
Heat-sensitive adhesive layer by heating at about ℃ for several seconds
When the (20) is activated, it gives tackiness and strong adhesive force to the heat-sensitive adhesive layer (20) by the action of the polymer material, tackifier, solid plasticizer and cross-linking type curing agent. That is, it can be firmly adhered to a glass bottle, a can container, a plastic molded product, etc. by being brought into close contact with the surface of a glass bottle or the like and appropriately pressurized.

Further, in the heat-sensitive adhesive label of the present invention, which can be easily peeled off, as shown in FIG. 2, in a normal bottle washing process with hot water or steam of about 80 ° C., a glass bottle (4
The heat-sensitive adhesive label attached to (0) is heated, and in a state where the heat-sensitive adhesive layer (20) that becomes sticky by heating is softened, micro-added to the heat-sensitive adhesive layer (20). By the thermal expansion of the capsule-shaped thermal expansion agent (21),
Adhesive surface (22) of heat-sensitive adhesive layer (20) with glass bottle (40)
Unevenness occurs, the adhesive force (contact area) of the sticking surface (22) with the glass bottle etc. (40) is reduced, and the microcapsule-like substance added to the heat-sensitive adhesive layer (20) Thermal expansion agent (2
Due to the thermal expansion of 1), due to the difference in thermal expansion between the label substrate (10) and the heat-sensitive adhesive layer (20), the heat-sensitive adhesive label is curled, such as in a glass bottle (40). The affixed heat-sensitive adhesive label is easily peeled from the glass bottle (40).

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a heat-sensitive adhesive label that can be easily peeled off in Examples 1, 2 and 3, and Comparative Example 3 of the present invention.

FIG. 2 is a partial cross-sectional view showing a state in which the heat-sensitive adhesive label of the present invention, which is easily peeled off, is easily peeled from the glass bottle or the like (40). is there.

[Explanation of symbols]

 10 ... Label base material, polyester film base material 11 ... Printed pattern layer 20 ... Heat-sensitive adhesive layer 21 ... Microcapsule-shaped thermal expansion agent 22 ... Adhesive surface with glass bottle (40) 40 ... Glass bottle etc.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuka Imai 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd.

Claims (2)

[Claims] 1. A back surface of a label base material (10) is basically composed of a polymer material, a tackifier and a solid plasticizer, and is of a cross-linking type with a microcapsule-shaped thermal expansion agent (21). A heat-sensitive adhesive label that is easily peeled off, characterized by being provided with a heat-sensitive adhesive layer (20) containing a curing agent. 2. A thermosensitive adhesive layer (20) comprising a polymeric material, a first thermosensitive adhesive component comprising a tackifier having a softening point of 100 ° C. or higher and a solid plasticizer, and a polymeric material. And a tackifier having a softening point of less than 100 ° C. and a solid plasticizer.
The heat-sensitive adhesive label according to claim 1, wherein the heat-sensitive adhesive component comprises a heat-sensitive adhesive component.