JP4580484B2 - Lid material - Google Patents

Description

上記で得られた積層体を断裁し所定位置にて打ち抜き、内面の周縁部に７ｍｍ巾の環状に感熱粘着剤層が形成された蓋材を作製した。
得られた蓋材を口径が１００ｍｍで口部フランジ巾が３ｍｍの内面にポリエチレンが積層された紙製容器の口部フランジに熱接着して取り付け、蓋材と容器の接着強度を測定した結果、６８０ｇ／１５ｍｍ巾の強度が得られ、熱接着した蓋材を容器から一部剥離した際に紙製容器の内面のポリエチレンが剥離してくることがなく、且つ容器から剥離した蓋材の熱接着部は粘着性を有しており、再び容器の口部を接着させて容器を封止することができた。
蓋材を容器に熱接着する条件は、温度１６０℃、圧力５ｋｇ／ｃｍ² 、加圧時間１．０秒とした。
【００２３】
【発明の効果】
内面の少なくとも容器と熱接着される熱接着部に感熱粘着剤層を有し、前記感熱粘着剤層が水性エマルジョン樹脂からなる感熱粘着剤組成物により形成された構成からなる蓋材とすることにより、この蓋材を容器に熱接着する際の加熱により感熱粘着剤層に粘着性が発現した状態となるので、とくにカップラーメン等の容器においては、蓋材を容器から一部剥離させて容器内に熱湯を注いだ後に、再び蓋材を容器の口部に押しつけることにより蓋材を容器に接着させて口部を塞ぐことができるとともに、口部を塞いだ状態を維持できるので熱が外部に逃げることがなく内容物を十分に加熱すことができる。
また、感熱粘着剤層が、蓋材が容器に熱接着される際に環状に形成される熱接着部の全体を覆うように周端縁に環状に形成された構成とすることにより、感熱粘着剤層を形成する面積が狭くなり感熱粘着剤組成物の使用量を減らすことができるとともに、絵柄の印刷工程と感熱粘着剤組成物を使用して印刷により感熱粘着剤層を形成する工程をインラインで行うことができるので、蓋材のコストダウンが可能となる。
上記の蓋材の構成を、外面から順に紙層と接着層とアルミニウム箔層と感熱粘着剤層が積層された構成とすることにより、遮光性が優れるとともに、カールが発生しにくくなり製造時の作業性および内容物充填時の作業性に優れた、再封可能な蓋材とすることができる。
感熱粘着剤層を、水溶性樹脂からなる海とガラス転移温度が−２０℃以下のラジカル重合性単量体の乳化重合により得られた樹脂からなる島との海島構造を有し、感熱粘着剤層を加熱することにより海と島が逆転して粘着性が発現する構成とすることにより、感熱粘着剤層を形成した状態では非粘着性であり、蓋材を容器に熱接着する際の加熱により粘着性が発現した状態となるので、製造時および内容物充填時の作業性に優れた再封可能な蓋材とすることができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示す底面図。
【図２】図１におけるＩ−Ｉ断面図。
【図３】第１実施形態の蓋材を容器に熱接着した状態を示す断面図。
【図４】本発明の第２実施形態を示す底面図。
【図５】図４におけるII−II断面図。
【図６】第２実施形態の蓋材を容器に熱接着した状態を示す断面図。
【符号の説明】
１，1' 蓋材
２ 摘み部
３ 容器
４ 熱接着部
11 紙層
12 接着層
13 アルミニウム箔層
14 感熱粘着剤層
14a 粘着性発現部
15 絵柄層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lid member that is used by thermally bonding to a mouth portion of a container.
[0002]
[Prior art]
Conventionally, as a lid material for sealing a container by attaching it to the mouth of a container such as a cup ramen by thermal bonding, it is made of paper / polyethylene / aluminum foil / thermal adhesive resin layer, and the thermal adhesive resin layer is ethylene- Generally, a heat-adhesive resin composed mainly of a vinyl acetate copolymer is laminated by hot melt extrusion.
However, in the case of a cup ramen container or the like, the lid material is partially peeled off from the container at the time of use, the sachet stored in the container is taken out, hot water is poured into it, the lid is closed again, and it is eaten after several minutes. However, in the case of the lid material having the above structure, when the lid material is partially peeled off from the container and then the lid is closed again, since the lid material does not adhere to the container, the lid material opens and opens the container. There is a drawback that the lid cannot be closed and the lid material warps upward while opening for a few minutes after pouring hot water into the container, and the heat escapes to the outside so that the noodles cannot be cooked sufficiently. In applications where hot water is poured and left to steam for a few minutes, such as fried noodles, the noodles must be drained and then drained. It is difficult to cut, and you may burn yourself with leaked water There has been a drawback that there is.
In addition, in the case of a container that takes out the contents with the lid part partially peeled off and uses it in small amounts, the container cannot be sealed again with the peeled lid material, so the container that has begun to be used Has the disadvantage of being unsuitable for storage.
[0003]
[Problems to be solved by the invention]
It is an object of the present invention to seal a container mouth portion by partially bonding the lid material thermally bonded to the container and then bonding the lid material to the mouth portion of the container again by bonding. Is to provide materials.
[0004]
[Means for Solving the Problems]
It is a lid that is thermally bonded to the mouth portion of the container by an annular thermal bonding portion, and the lid is composed of a paper layer, an adhesive layer, an aluminum foil layer, and a heat-sensitive adhesive layer laminated in order from the outer surface, The heat-sensitive adhesive layer is composed of a layer having a thickness of 5 to 10 μm formed by printing twice using a gravure printing plate, and is thermally bonded directly to the aluminum foil layer and to the inner container. It is formed on the bonding portion, the when the lid member is thermally bonded to the container the heat-sensitive adhesive layer, is formed annularly on the peripheral edge to cover the entire heat-bonded portion formed annularly, the thermosensitive adhesive By making the width of the agent layer wider than the width of the heat-bonding part at the mouth of the container, the heat-sensitive adhesive layer is a lid made of a heat-sensitive adhesive composition made of an aqueous emulsion resin. Heat-sensitive adhesive layer by heating when this lid material is thermally bonded to the container Since the adhesiveness is developed, especially in containers such as cup ramen, the lid is partially peeled from the container, hot water is poured into the container, and then the lid is pressure-bonded to the mouth of the container again. Thus, the lid can be adhered to the container to close the mouth, and the state where the mouth is closed can be maintained, so that the contents can be sufficiently cooked without the heat escaping to the outside.
[0005]
Furthermore, the heat-sensitive adhesive layer is formed in an annular shape on the peripheral edge so as to cover the entire heat-bonded portion formed in a ring shape when the lid is thermally bonded to the container. Since the area for forming the adhesive layer can be narrowed, the amount of the heat-sensitive adhesive composition used can be reduced, and the printing process of the pattern and the process of forming the heat-sensitive adhesive layer by printing using the heat-sensitive adhesive composition. Since it can be performed in-line, the cost of the lid can be reduced. In addition, since the paper layer, the adhesive layer, the aluminum foil layer, and the heat-sensitive adhesive layer are laminated in order from the outer surface, the light shielding property is excellent and curling is less likely to occur. A re-sealable lid material excellent in workability when the lid material is thermally bonded to the container can be obtained.
[0006]
In the above lid material, the heat-sensitive adhesive layer is formed with a thickness of 5 to 10 μm, the surface of the heat-sensitive adhesive layer of the lid material is thermally bonded to the mouth of the container, and the obtained adhesive strength is 600 to 800 g / 15 mm. It is characterized by a width .
[0007]
In the above lid material, a sea-island structure of a sea where the heat-sensitive adhesive layer is made of a water-soluble resin and an island made of a resin having a glass transition temperature of −20 ° C. or less obtained by emulsion polymerization of a radical polymerizable monomer. The heat and pressure sensitive adhesive layer is heated and the sea and islands are reversed so that the adhesiveness is expressed. Without causing any trouble in the process, the heat-sensitive adhesive layer can be brought into a state of adhesiveness by heating when the lid is thermally bonded to the container. The opening can be sealed by adhering to the container.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a bottom view showing a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II in FIG. 1, and FIG. 3 is a cross-sectional view showing a state in which the lid of the first embodiment is thermally bonded to a container. 4 is a bottom view showing a second embodiment of the present invention, FIG. 5 is a sectional view taken along the line II-II in FIG. 4, and FIG. 6 is a sectional view showing a state in which the lid of the second embodiment is thermally bonded to the container. 1, 1 'is a cover material, 2 is a knob, 3 is a container, 4 is a heat bonding part, 11 is a paper layer, 12 is an adhesive layer, 13 is an aluminum foil layer, 14 is a heat-sensitive adhesive layer, and 14a is an adhesive. Sex expression part, 15 represents a picture layer, respectively.
[0009]
The lid | cover material 1 of 1st Embodiment of this invention is as showing in FIG. 1, FIG. As shown in FIG. 1, the shape of the lid 1 is a circular shape, provided with a knob 2 protruding outward at the peripheral edge, and a heat-sensitive adhesive layer 14 is formed on the entire inner surface. Yes. As shown in FIG. 2, the laminated structure of the lid member 1 is a structure in which a heat-sensitive adhesive layer 14, an aluminum foil layer 13, an adhesive layer 12, a paper layer 11, and a picture layer 15 are laminated in order from the inner surface. Regarding the laminated structure, it is sufficient that the heat-sensitive adhesive layer 14 is provided on the inner surface, and the structure on the outer surface side is arbitrary. In the first embodiment, the shape of the lid member 1 is a circular shape, but may be an arbitrary shape such as an elliptical shape, a quadrangular shape, or a polygonal shape depending on the shape of the mouth of the container to be used.
[0010]
The cross-sectional shape of the state in which the lid 1 of the first embodiment is attached to the mouth of the container 3 having a circular opening by thermal bonding is as shown in FIG. The lid 1 is attached to the mouth of the container 3 by thermal bonding at the thermal bonding portion 4 by a heat-sensitive adhesive layer 14 formed on the inner surface. When the lid 1 is attached to the container 3 by heat bonding, it becomes a pressure-sensitive adhesive layer 14a in which the pressure-sensitive adhesive layer 14 corresponding to the heat-bonding portion 4 has been heated, and the pressure-sensitive adhesive layer 14a has been developed. Bonded to the container 3. Therefore, when the lid 1 is grasped by the gripping part 2 and partially peeled off from the container 3, the peeled portion exhibits adhesiveness. Therefore, after pouring hot water into the container 3, the portion of the lid 1 peeled off By pressing against the mouth of the container 3, the opening can be covered by adhering to the mouth of the container 3, so that hot air does not escape and heat insulation can be improved.
[0011]
The lid 1 ′ of the second embodiment of the present invention is as shown in FIGS. As shown in FIG. 4, the shape of the lid 1 ′ is circular, and is provided with a knob portion 2 that protrudes outward at the peripheral edge, and has a constant width at the peripheral edge except for the knob portion 2 on the inner surface. A heat-sensitive adhesive layer 14 is formed in the annular shape. The heat-sensitive adhesive layer 14 is formed in an annular shape so as to cover the entire heat-bonding portion 4 where the lid 1 'is thermally bonded to the mouth portion of the container 3, and the inner side of the annular heat-sensitive adhesive layer 14 is formed. In this region, the aluminum foil layer 13 is exposed. The width of the annular heat-sensitive adhesive layer 14 is wider than the width of the thermal bonding portion 4 at the mouth of the container. Although the shape of the lid 1 ′ of the second embodiment is circular, the shape of the lid 1 ′ may be arbitrarily changed according to the shape of the opening of the container. Note that an anchor material layer or an aluminum foil protective layer may be formed on the surface of the lid material 1 ′ of the second embodiment where the heat-sensitive adhesive layer 14 of the aluminum foil layer 13 is formed.
[0012]
As shown in FIG. 5, the cross-sectional shape of the lid material 1 ′ of the second embodiment is such that a heat-sensitive adhesive layer 14, an aluminum foil layer 13, an adhesive layer 12, a paper layer 11, and a picture layer 15 are laminated in order from the inner surface. The heat-sensitive adhesive layer 14 is formed in a ring shape on the surface of the aluminum foil layer 13. The heat-sensitive adhesive layer 14 is formed in an annular shape with a constant width on the periphery of the lid 1 'excluding the knob 2 on the surface of the aluminum foil 13, and the heat-sensitive adhesive layer 14 is applied to the entire surface of the aluminum foil 13 as in the first embodiment. Compared with forming the agent layer 14, the amount of the heat-sensitive adhesive composition used to form the heat-sensitive adhesive layer 14 can be reduced, and the step of forming the heat-sensitive adhesive layer 14 in a ring shape Since the process can be reduced in-line with the printing process for forming the pattern layer 15 on the paper layer 11, the cost of the lid can be reduced.
[0013]
The cross-sectional shape of the state in which the lid 1 'of the second embodiment is attached by thermal bonding to the flange of the mouth of the container 3 having a circular opening is as shown in FIG. The heat-sensitive adhesive layer 14 formed in an annular shape on the peripheral edge of the lid material with a width wider than that of the heat-bonding part 4 is a heat-sensitive adhesive corresponding to the heat-bonding part 4 by heating when the lid material is thermally bonded to the container. The layer 14 is adhered to the mouth portion of the container 3 in a state where the layer 14 becomes a pressure-sensitive adhesive portion 14a where the pressure-sensitive property is expressed. Accordingly, when the lid material 1 ′ is partly peeled from the container 3, the peeled thermal bonding part 4 exhibits stickiness. After pouring hot water into the container 3, the peeled part of the lid material 1 ′ is removed from the container 3 By pressing against the 3 mouths, the opening can be sealed by adhering to the mouth of the container 3.
[0014]
As the heat-sensitive adhesive composition constituting the heat-sensitive adhesive layer used in the present invention, for example, as described in Japanese Patent Application Laid-Open No. 8-269420 or Japanese Patent Application Laid-Open No. 11-5959, there is no non-initial state. It is possible to use a heat-sensitive adhesive composition that is very sticky or very sticky and that develops stickiness when heated to a certain temperature or higher.
[0015]
The delayed tack-type pressure-sensitive adhesive composition described in JP-A-8-269420 includes (A) 3 to 60% by weight of an unsaturated monomer having a carboxyl group, 40 to 97% by weight of a hydrophobic monomer, A resin-containing solution containing a resin having a glass transition temperature of 20 ° C. or higher obtained by copolymerizing 0 to 50% by weight of other monomers, and containing 5% by weight or more of a solubilized resin; B) A delayed tack comprising a water-based acrylic resin emulsion composed of a resin having a glass transition temperature of −30 ° C. or less, wherein the weight ratio (A) / (B) of each component is 15/85 to 50/50 Type pressure-sensitive adhesive composition.
[0016]
In the above delayed tack type pressure-sensitive adhesive composition, the unsaturated monomer having a carboxyl group is acrylic acid, methacrylic acid, itaconic acid, etc., and the hydrophobic monomer is methyl methacrylate, ethyl acrylate, butyl acrylate, Examples thereof include ethylhexyl acrylate, vinyl chloride, vinyl acetate, ethylene, and butadiene, and other monomers include acrylamide, 2-hydroxyethyl acrylate, diacetone acrylamide, and the like. In addition, homopolymers such as butyl acrylate, 2-ethylhexyl acrylate, and lauryl acrylate are used as the aqueous acrylic resin emulsion made of a resin having a glass transition temperature of −30 ° C. or lower.
[0017]
JP-A-11-5959 discloses a heat-sensitive adhesive composition comprising: (A) a water-soluble resin obtained by neutralizing a resin having an acid value of 1 meq / g or more with a base; and (B) a radical polymerizable monomer. An aqueous emulsion-type pressure-sensitive adhesive composition comprising a polymer having a glass transition temperature of −20 ° C. or lower obtained by emulsion polymerization of the body, wherein component (A) becomes sea and component (B) by drying below 60 ° C. A heat-sensitive adhesive composition comprising a sea-island structure that becomes an island, and the above-mentioned sea-island structure is reversed by heat treatment at 60 ° C. or higher, and (A) the component becomes an island and (B) the component becomes the sea and develops adhesiveness. It is a thing. The above-mentioned sea-island structure is not limited to a structure in which the sea (continuous layer) is completely continuous and all of the islands (discontinuous layer) are dispersed independently in the sea, but the sea is partially interrupted. And a state where a part of the island is fused with each other.
[0018]
In the above heat-sensitive adhesive composition, as the component (A), a copolymer having an α, β-ethylenically unsaturated carboxylic acid unit and a hydrophobic radical polymerizable monomer unit as main constituent units is preferably used. As the α, β-ethylenically unsaturated carboxylic acid, one or more of acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride and the like are used. As the radical polymerizable monomer, (meth) methyl methacrylate, methyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, (meth) Isobutyl acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, α-methylstyrene, vinyltoluene and the like are used. (B) As a polymer having a glass transition temperature of −20 ° C. or lower obtained by emulsion polymerization of the radically polymerizable monomer as a component, an emulsion polymer of an acrylic monomer, an ethylene-vinyl ester monomer Emulsion polymers of conjugated diene monomers can be used. Acrylic monomers include methyl (meth) methacrylate, methyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylic. Isobutyl acid, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like as vinyl ester monomers in ethylene-vinyl ester monomers, vinyl acetate, vinyl pyropionate, vinyl butyrate, laurin Examples of the conjugated diene monomer include butadiene, isoprene, chloroprene, and isobutylene.
[0019]
The thickness of the heat-sensitive adhesive layer 14 is preferably 5 to 10 [mu], and can be formed by printing twice using a gravure printing plate having a depth of 40 to 60 [mu]. By forming a heat-sensitive adhesive layer to a thickness of 5 to 10 μm on the aluminum foil surface as in the first and second embodiments, the foamed polystyrene container and the mouth of the paper container in which polyethylene is laminated on the inner surface By heat-bonding, the heat-sensitive pressure-sensitive adhesive layer is bonded to the container in a state where the pressure-sensitive adhesive layer is expressed, and an adhesive strength of 600 to 800 g / 15 mm width is obtained. In addition, when the lid member is peeled from the container, the aluminum foil of the lid member is not broken and peeled off, and the polyethylene on the inner surface of the paper container is not peeled off. In addition, when the lid is peeled from the container, the adhesiveness is developed in the heat-bonded part of the heat-sensitive adhesive layer of the lid, so that when the lid is closed, the lid is adhered again to the container and the mouth is sealed. It is possible to stop.
[0020]
As the configuration of the lid material, a configuration comprising a paper layer, an adhesive layer, an aluminum foil layer, and a heat-sensitive adhesive layer as in the first and second embodiments, and a configuration in which the adhesive layer is a hot melt extruded layer of polyethylene is most preferable. The paper layer may be a synthetic paper or a laminate of paper and a plastic film. Moreover, it is also possible to make it the structure which consists of a paper layer, a synthetic resin layer, and a heat-sensitive adhesive layer without using an aluminum foil layer, and what is necessary is just to determine arbitrarily a laminated structure with the required physical property.
[0021]
The method of manufacturing the lid material according to the embodiment, after laminating roll-shaped paper and aluminum foil by extrusion lamination using polyethylene as an adhesive layer, printing a predetermined print pattern by gravure printing or the like on the laminated paper surface, Heat sensitive adhesive made of water-based emulsion resin by solid-printing the heat-sensitive adhesive composition made of water-based emulsion resin on the opposite aluminum foil surface or registering with the pattern layer printed on the paper surface of aluminum foil surface The composition is printed in a ring shape having a predetermined width and dried at a temperature of 60 ° C. or lower to form a heat-sensitive adhesive layer. Thereafter, the lid material of the first and second embodiments can be manufactured by cutting into a sheet shape and punching at a predetermined position. By manufacturing by the above method, paper and aluminum foil are extruded and laminated with polyethylene, the printing process of the pattern layer on the laminated paper surface, and the heat-sensitive adhesive composition is printed on the aluminum foil surface on the opposite side. Since the step of forming the pressure-sensitive adhesive layer can be performed in-line, it is not necessary to provide a separate step of forming the heat-sensitive pressure-sensitive adhesive layer, and the cost can be reduced by reducing the number of steps.
[0022]
【Example】
Example 1
After laminating a piece of art paper with a basis weight of 79 g / m ² and 7 μm aluminum foil by extrusion lamination of 20 μm polyethylene, a pattern is formed on the surface of the laminated piece of art paper by gravure printing. On the laminated aluminum foil surface, the following heat-sensitive adhesive composition is printed twice with a gravure printing plate having a depth of 50 μm and dried at a temperature of 60 ° C. or less, so that the component (A) has a thickness of 8 μm. Laminating for heat-sensitive adhesive layer having a sea-island structure in which (B) component is an island so that the width of the heat-sensitive adhesive layer is 7 mm when the cover material is completed. The body was made.
[Thermosensitive adhesive composition]

The laminated body obtained above was cut and punched out at a predetermined position to prepare a lid material in which a heat-sensitive adhesive layer was formed in a 7 mm-width annular shape on the periphery of the inner surface.
As a result of thermally bonding and attaching to the mouth flange of a paper container in which polyethylene was laminated on the inner surface with a diameter of 100 mm and a mouth flange width of 3 mm, and measuring the adhesive strength between the lid and the container, A strength of 680 g / 15 mm width is obtained, and the polyethylene on the inner surface of the paper container is not peeled off when the heat-bonded lid is partially peeled from the container, and the lid is peeled off from the container. The part had adhesiveness, and the container was able to be sealed by adhering the mouth of the container again.
The conditions for thermally bonding the lid material to the container were a temperature of 160 ° C., a pressure of 5 kg / cm ² , and a pressurization time of 1.0 second.
[0023]
【The invention's effect】
By having a heat-sensitive adhesive layer in a heat-bonded part that is thermally bonded to at least the inner surface of the container, and the heat-sensitive pressure-sensitive adhesive layer is made of a heat-sensitive adhesive composition made of an aqueous emulsion resin. In addition, since the heat-sensitive adhesive layer becomes sticky due to heating when the lid material is thermally bonded to the container, particularly in containers such as cup ramen, the lid material is partially peeled off from the container. After pouring hot water into the container, the lid can be pressed again against the mouth of the container to adhere the lid to the container and close the mouth. The contents can be heated sufficiently without escaping.
Further, the heat-sensitive adhesive layer is formed in an annular shape on the peripheral edge so as to cover the entire heat-bonding portion formed in a ring shape when the lid is thermally bonded to the container. The area for forming the adhesive layer is reduced and the amount of heat-sensitive adhesive composition used can be reduced. In addition, the printing process of the pattern and the process of forming the heat-sensitive adhesive layer by printing using the heat-sensitive adhesive composition are inlined. Therefore, the cost of the lid can be reduced.
By making the configuration of the above-mentioned lid material a paper layer, an adhesive layer, an aluminum foil layer, and a heat-sensitive adhesive layer in order from the outer surface, the light shielding property is excellent and curling is less likely to occur. A re-sealable lid material excellent in workability and workability when filling the contents can be obtained.
The heat-sensitive adhesive layer has a sea-island structure having a sea made of a water-soluble resin and an island made of a resin obtained by emulsion polymerization of a radical polymerizable monomer having a glass transition temperature of −20 ° C. or less. By heating the layer, the sea and islands are reversed and the adhesiveness is developed, so that the heat-sensitive adhesive layer is non-adhesive when it is formed, and heating when the lid is thermally bonded to the container Thus, a re-sealable lid material excellent in workability at the time of manufacturing and filling the contents can be obtained.
[Brief description of the drawings]
FIG. 1 is a bottom view showing a first embodiment of the present invention.
2 is a cross-sectional view taken along the line II in FIG.
FIG. 3 is a cross-sectional view showing a state where the lid according to the first embodiment is thermally bonded to a container.
FIG. 4 is a bottom view showing a second embodiment of the present invention.
5 is a sectional view taken along line II-II in FIG.
FIG. 6 is a cross-sectional view showing a state in which the lid of the second embodiment is thermally bonded to a container.
[Explanation of symbols]
1,1 'Lid 2 Picking part 3 Container 4 Thermal bonding part
11 Paper layer
12 Adhesive layer
13 Aluminum foil layer
14 Heat-sensitive adhesive layer
14a Adhesive development part
15 Pattern layer

Claims (3)

It is a lid that is thermally bonded to the mouth portion of the container by an annular thermal bonding portion, and the lid is composed of a paper layer, an adhesive layer, an aluminum foil layer, and a heat-sensitive adhesive layer laminated in order from the outer surface, The heat-sensitive adhesive layer is composed of a layer having a thickness of 5 to 10 μm formed by printing twice using a gravure printing plate, and is thermally bonded directly to the aluminum foil layer and to the inner container. It is formed on the bonding portion, the when the lid member is thermally bonded to the container the heat-sensitive adhesive layer, is formed annularly on the peripheral edge so as to cover the entire heat-bonded portion formed annularly, the thermosensitive adhesive The lid material is characterized in that the width of the agent layer is wider than the width of the heat-bonding portion at the mouth of the container, and the heat-sensitive adhesive layer is formed of a heat-sensitive adhesive composition comprising an aqueous emulsion resin. . 2. The lid according to claim 1, wherein the heat-sensitive adhesive layer surface of the lid is thermally bonded to the mouth of the container, and the obtained adhesive strength is 600 to 800 g / 15 mm width. The heat-sensitive adhesive layer has a sea-island structure between a sea made of a water-soluble resin and an island made of a resin having a glass transition temperature of −20 ° C. or less obtained by emulsion polymerization of a radical polymerizable monomer, The lid material according to claim 1, wherein the cover material is configured such that when the pressure-sensitive adhesive layer is heated, the sea and the islands are reversed and the adhesiveness is expressed .

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