JPH0219262A - Heat-sealing cover member for seal pack vessel - Google Patents

Abstract

PURPOSE:To securely protect water permeation into a heat-seal part, by providing an adhesion aid having an adhesive nature on the surface to heat-seal with the opening of a vessel for seal pack. CONSTITUTION:A heat-sealing member layer 2 containing an adhesion aid with an adhesive nature is provided as a cover member via an adhesive layer 3 on one side of aluminum foil 1, and the adhesion aid having an adhesive nature exists on the surface to heat-seal with an opening 10 of a vessel for seal pack like glass ware, etc. A corrosion-proof coat layer 4 is supplied on the other face of the aluminum foil 1.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a heat-sealable lid material for a sealed packaging container.

Conventional technology Conventionally, in order to hermetically package powdered, liquid, or viscous foods in glass containers such as bottles, a metal cap is caulked to the mouth of the container after the food is filled, or a metal or synthetic resin cap is used. It was sealed by screwing on a screw cap or by putting a crown on it. Conventionally, a lid material has been coated with a thermoadhesive resin, and this lid material has been bonded to the mouth of a glass container by heat sealing.

Problems to be Solved by the Invention However, the above-mentioned caps and crowns have problems in that they are relatively difficult to open and are expensive. In addition, when heat-sealing the heat-adhesive resin coated on the lid to the mouth of a glass container, if the contents of the container are powder such as powdered milk or instant coffee, there is a gap between the mouth of the container and the lid. Although there is no decrease in the adhesive strength of the adhesive part, if the contents are liquid or viscous substances such as alcohol, juice, or jam, the heat-sealed adhesive part between the container mouth and the lid material may be damaged during storage. Water gets in and the adhesion strength decreases significantly.
In severe cases, there was a problem in that the lid material would peel off.

In particular, when directly thermally bonding a lid to the mouth of a glass container, the surface of the mouth of the glass container is porous, has relatively weak polarity, and has poor adhesion. In recent years, the use of carboxyl-modified saponified ethylene-vinyl acetate copolymers with improved adhesive properties has been developed (for example, in JP-A-60-178).
(See Publication No. 042). Such thermoadhesive resins certainly have excellent thermal adhesion properties in a very short period of time and at relatively low temperatures, and also have a moderate adhesive strength that satisfies the requirements for easy opening. Although there are
If water enters the bonded portion after heat sealing, there is a problem in that the adhesiveness is significantly reduced and the lid material is easily peeled off from the bonded interface.

By the way, it has already been known to directly coat the mouth of a glass container with a silane coupling agent as a sealing material (for example, see Japanese Patent Publication No. 8273/1983). The work of coating the sealant is extremely troublesome, and the surface of the opening of the glass container is porous and uneven, making it difficult to apply the sealant uniformly. Therefore, if the amount of sealing material applied is not sufficient, it will be difficult to achieve a uniform seal due to the unevenness of the opening, variations in parallelism, etc., and if the amount applied is too large,
There was a problem of high cost.

Furthermore, a method is already known in which a metal salt, a silane coupling agent, etc. are used as an anchor coat layer on the opening of a glass container, and this layer is further coated with a thermoadhesive resin (for example, Japanese Patent Publication No. 61-9181) However, with this conventional method, when the container is opened, some of the resin from the lid material may remain at the mouth of the container, damaging the appearance, and the mouth of the container must be coated with thermoplastic resin in advance. Therefore, the number of steps increases accordingly,
There were problems in that the productivity of the container was poor and the cost was high.

The purpose of the present invention is to solve the problems of the prior art described above, and to provide a material that has extremely excellent adhesion even to a porous and relatively weakly polar adhered surface such as the mouth of a glass container. Not only can the lid material be heat-sealed to the mouth of the hermetically sealed packaging container in a short time, but it can also be used when the container contents are liquid or viscous, such as alcohol, juice, or jam. It is possible to reliably prevent water from entering the sealing area, greatly increasing the water resistance of the heat-sealing area, reducing the decrease in adhesive strength in a water environment, and maintaining a good adhesive state for a long period of time. An object of the present invention is to provide a heat-sealing lid material for a sealed packaging container, which can improve sealing performance under easy-open conditions.

Means for Solving the Problems In order to achieve the above-mentioned object, the heat-sealing lid material for a hermetically sealed packaging container according to the present invention has adhesive adhesive on the surface to be thermally bonded to the opening of the hermetically sealed packaging container. It is characterized by the presence of an auxiliary agent.

Here, there are two ways to make the adhesion aid having adhesiveness exist on the surface of the lid material to be thermally bonded.

(1) First of all, a heat sealing material layer containing an adhesive adhesion agent is provided on one side of the metal stone as the base material of the lid material, so that it can be thermally bonded to the mouth of the sealed packaging container. When an adhesion aid with adhesiveness is present on the surface to be used.

(II) Second, a heat sealing material layer is provided on one side of the metal foil, and the surface of the heat sealing material layer is coated with an adhesive adhesion agent, thereby sealing the opening of the sealed packaging container. When an adhesive adhesion agent is present on the surface to be thermally bonded.

In the above, the metal foil that is the base material of the lid material is usually aluminum foil, but other metal foils may be used. In the case of aluminum foil, its thickness is 5 to 200 mm,
Preferably it is 20 to 60 μm.

As the heat sealing material, any commonly used heat sealing material can be used.

Specifically, as a heat sealing material, polyethylene, a copolymer of ethylene and vinyl acetate, a copolymer of ethylene and an unsaturated carboxylic acid, or a saponified product of an ethylene-vinyl acetate copolymer and a carboxyl group-containing inorganic material are used. Modified products obtained by graft polymerization of saturated compounds, ionomers, water-dispersed polyolefins, mixtures of water-dispersed polyolefins and water-soluble epoxy resins, polyesters, modified polypropylene, polyvinyl chloride, polyvinyl butyral, polymethacrylic esters, and polyacrylic acids At least one thermoplastic synthetic resin selected from the group consisting of esters is used.

Among these resins, ethylene-vinyl acetate and ethylene-vinyl acetate have excellent thermal adhesion properties in a short time and at relatively low temperatures to the porous and relatively weakly polar mouth surface of glass containers. Modified products obtained by graft polymerizing a carboxyl group-containing unsaturated compound to a saponified polymer (see, for example, JP-A-80-178042), and ionomers (see, for example, JP-A-61-54587).
It is preferable to use

Here, the former carboxyl modified product of saponified ethylene-vinyl acetate copolymer is, for example, as follows.

That is, melt index 1-300g/10
(according to ASTM 1238-65T) and an ethylene content of 50 to 97 mol%, preferably 7
A saponified product having a hydroxyl group equivalent of 100 to 3000 g/1 equivalent, preferably 200 to 1000 g/1 equivalent is prepared by saponifying 0 to 92 moles of an ethylene-vinyl acetate copolymer, and then a carboxylic acid is added to this saponified product. It is obtained by graft polymerizing a group-containing unsaturated compound.

Here, examples of the carboxylic acid group-containing unsaturated compound include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, and citraconic acid. The obtained graft polymer, that is, the carboxyl modified product of the saponified ethylene-vinyl acetate copolymer, has a total weight of 50,000 g per acid equivalent.
/ less than the equivalent, preferably 1000 to 10000 g/
1 equivalent.

The latter ionomer is composed of a monoolefin-unsaturated carboxylic acid copolymer resin or a metal salt thereof.

Here, the monoolefin-unsaturated carboxylic acid copolymer resin includes an α-monoolefin such as ethylene, propylene, 1-butene, isobutyne, 4-methyl-1-pentene, 1-hexene, and 1-heptene; α such as acrylic acid, methacrylic acid, methacrylic acid, crotonic acid,
It is based on a resin obtained by copolymerizing β-unsaturated carboxylic acid, and typical examples include ethylene-acrylic acid copolymer resin and ethylene-methacrylic acid copolymer resin. It will be done. The molecular weight of such a copolymer resin is 1,000 to 200,000, and the unsaturated carboxylic acid content in the copolymer resin is 1 to 30% by weight, preferably 2 to 20% by weight.

Examples of metal salts of monoolefin-unsaturated carboxylic acid copolymer resins include alkali metal ions such as sodium and potassium, or alkaline earth metals such as zinc and magnesium. Examples include ionically crosslinked resins, ie, ionomer resins, obtained by neutralization with ions. The degree of neutralization by metal ions is, for example, 0.5 to 40%. In particular, it is preferable to use an ionomer resin made of a zinc salt of an ethylene-methacrylic acid copolymer resin. The carboxylic acid content of the ionomer resin is 5-18%, and the degree of ionization is several %-9.
It is 0%.

Examples of the adhesion aid having adhesive properties include alkylphenol resins, alkylphenol-modified xylene resins, terpenephenol resins, terpene resins, olefin resins, styrene resins, aromatic petroleum resins, and coumaron-indene resins.

These compounds can be used as adhesion aids with adhesive properties.
More than one type may be mixed.

The thickness of the heat sealing material layer is usually 5 to 3001 m, preferably 20 to 10 G.

By providing a heat sealing material layer containing an adhesive adhesion agent on one side of the metal foil of the lid material in (1) above, the surface to be thermally bonded to the opening of the sealed packaging container has adhesive properties. When an adhesion aid having the following is present, the content of the adhesion aid responsible for the adhesiveness of the heat sealing material layer is 0.01 to 10% by weight,
Preferably it is 0.5 to 3% by weight.

Furthermore, a heat sealing material layer is provided on one side of the metal foil of the lid material in (II) above, and the surface of this heat sealing material layer is coated with an adhesive adhesion agent, thereby making it possible to seal the container for sealed packaging. When an adhesive adhesion agent is present on the surface to be thermally bonded to the opening, the thickness of the coating layer of the adhesive adhesion agent is 0.01 to 10, preferably 0.5. ~5ulII.

In the case of (1)(n) above, when the content of the adhesive adhesion aid is less than 0.01% by weight, and the thickness of the coating layer of the adhesive adhesion aid is o,
If it is less than oi cut, the amount of adhesion aid having adhesiveness is too small, and sufficient water resistance is not imparted to the heat-sealed joint, and adhesiveness decreases in a water environment, which is undesirable. .

Conversely, the content of adhesion aid with adhesiveness is IOff.
im%, or when the thickness of the adhesive adhesion promoter coating layer exceeds 10/ffl,
Not only does the adhesion not change much in an aqueous environment, but it also increases the cost, which is not preferable.

In addition, when a heat sealing material layer containing an adhesive adhesion agent is provided on one side of the metal foil of the lid material in (1) above, the adhesive adhesion agent having adhesiveness is formed on the surface of the heat sealing material layer. It bleeds, diffuses to the surface side, and becomes concentrated. in this case,
It is preferable that the adhesive adhesion agent be present in an amount of 1% or more on the surface of the mouth of the sealed packaging container to be heat-sealed, that is, on the surface of the heat-sealing material layer.

In addition, when coating the surface of the heat sealing material layer provided on one side of the metal foil of the lid material in (■) above with an adhesive adhesion agent, it should be thermally bonded to the mouth of the sealed packaging container. Therefore, the thickness of the coating layer, that is, the amount of the adhesive adhesion agent present on the surface to be heat-sealed is adjusted according to the above method. This is easier than case (1).

Further, the heat sealing material layer is preferably filled with an inorganic compound in order to ensure low-temperature sealability and to prevent blocking during punching by press.

Here, examples of inorganic compounds include oxides, hydroxides, carbonates, and sulfates of magnesium, calcium, aluminum, titanium, and silicon, talc, clay, feldspar powder, mica, pallite, etc., and particularly preferred. Calcium carbonate, talc is used.

The average particle size of these inorganic compounds is 0.1 to 50 μm1, preferably 0.5 to 30 μm, and the thermal adhesive resin 100ffi
! 30 parts by weight or less, usually 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, of the above-mentioned inorganic compound.

The above-mentioned heat-adhesive resin and inorganic compound are mixed using, for example, a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, etc., usually at a temperature of 15 to 200°C. Further, the drying time varies depending on the drying temperature, but is, for example, about 30 seconds at 100°C.

To provide a heat sealing material layer on one side of the metal foil, a heat sealing material containing or not containing an adhesive adhesion agent as described above is processed into a film in advance, and this film is applied to one side of the metal foil. For example, it can be bonded to the metal foil through an adhesive such as a two-component reactive adhesive based on polyester isocyanate, or it can be directly bonded by extruding a melted heat sealing material onto one side of the metal foil using an extruder. Just do it like this.

Further, when coating the surface of the heat sealing material layer with an adhesion aid having adhesive properties, it may be carried out, for example, by a spray method, a brushing method, a roll coating method, or the like.

Note that, if necessary, a resin film such as polyethylene or polypropylene may be interposed between the heat sealing material layer and the metal foil. This improves cushioning properties during heat sealing and prevents corrosion of the metal foil due to contents such as dressing and mustard.

Note that the other side of the metal foil is usually subjected to necessary printing, and furthermore, an anticorrosive coating layer is provided on this surface. A lid made of metal foil and a heat sealing material layer is continuously punched and formed into a shape and size that covers the mouth of a glass container.

The hermetically sealed packaging container sealed by the heat-sealable lid according to the present invention is made of, for example, glass, metal, ceramic, or earthenware.

1 to 3 show specific examples of the lid material according to the present invention. First, the lid material shown in Fig. 1 is made by providing a heat sealing material layer (2) containing an adhesive adhesive on one side of an aluminum foil (1) with an adhesive layer (3) interposed therebetween; An adhesive adhesion agent is present on the surface to be thermally bonded to the opening (10) of a sealed packaging container such as a container. An anticorrosive coating layer (4) is applied to the other side of the aluminum foil (1).

In addition, the lid material shown in Fig. 2 has a heat sealing material layer (2) provided on one side of an aluminum foil (■) with an adhesive layer (3) interposed therebetween. A coating layer (5) of an adhesive adhesion agent is applied so that the adhesive adhesion agent is present on the surface to be thermally bonded to the mouth (10) of the glass container. It is. The other side of the aluminum foil (1) is similarly coated with an anti-corrosion coating layer (
4) has been applied.

Furthermore, the lid material shown in FIG. 3 has almost the same structure as the lid material shown in FIG. A heat sealing material layer (2) containing an adhesive adhesion agent is provided to this intermediate layer (7) via an adhesive layer (3), and an aluminum foil layer (7) is provided. A printing layer (6) is provided on the other side of (1),
Furthermore, an anticorrosive coating layer (4) is provided on the surface.

According to the heat-sealing lid material of the invention of Σ, since an adhesive adhesion agent is present on the surface to be thermally bonded to the opening (10) of the sealed packaging container, the bonding does not occur in a water environment. This is thought to be due to the following reasons: the strength decreases little, a good adhesion state can be maintained for a long period of time, and the sealing properties are excellent.

That is, for example, the heat sealing material applied to the lid of a glass container contains -OH groups and -CO because the upper surface of the mouth of the glass container is porous, has relatively weak polarity, and has poor adhesive properties.
Resins containing many functional groups such as OH groups, such as carboxyl modified products of saponified ethylene-vinyl acetate copolymers in which 10H groups or -COOH groups are introduced into monoolefins,
and ionomer resins are used to improve adhesion, but even when such resins are used, the heat sealing process time is very short, so the functional groups in the heat sealing resin are not bonded to the glass. It is thought that the resin does not interact with the glass component on the upper surface of the mouth of the container to form hydrogen bonds, but instead adheres to the glass surface mainly due to van der Waals forces. In particular, during heat sealing, as the heat sealing material melts, the polymer main chain with polar groups in the heat sealing material becomes free, and the polar groups are oriented toward the glass surface and form the polymer main chain. It will be cooled and solidified with the stress remaining. In addition, immediately after heat sealing, the molecular segments of the heat sealing resin undergo thermal movement and their orientation is disordered, so hydrogen bonds are less likely to occur.
, the bond is mainly due to van der Waals forces.

After heat sealing, the functional groups form hydrogen bonds with the silanol groups on the glass surface over time, and the adhesive strength gradually increases.

However, when the contents of a glass container are liquid or viscous, the glass surface at the mouth of the container is hydrophilic, so water molecules tend to get wet, forming a multimolecular layer of water molecules. As a result of the force acting on the glass to break the bond with the glass, so-called stress cracks (stress release in the main chain) occur, causing the polar groups in the polymer main chain to rotate and move in different directions. This weakens the van der Waals force of the heat-sealed bond and breaks hydrogen bonds, resulting in a significant decrease in adhesive strength.

On the other hand, according to the heat-sealing lid material of the present invention, since an adhesive adhesion agent is present on the surface to be heat-bonded to the opening of the glass container, the heat-sealing material can be easily sealed during heat-sealing. The adhesive adhesion agent present on the material surface first bonds with the glass surface, and this adhesive adhesion agent acts as a binder between the heat sealing material and the glass surface. The bond between the material and the glass surface relieves the stress remaining in the polymer main chain in the heat sealing material, and the adhesive force between the heat sealing material of the lid material and the opening surface of the glass container becomes extremely strong, resulting in a strong bond. It is possible to effectively prevent water from entering the interface, and the water resistance of the heat-sealed bonded portion is greatly increased.

Example Next, examples of the present invention will be described together with comparative examples.

Example 1 As shown in Fig. 1, various amounts of adhesion aids were mixed on the other side of a 50-cut aluminum foil (1) having an anticorrosive coating layer (4) on one side. Thickness 50/f
A heat sealing material layer (2) consisting of a heat sealing material film of f was bonded via an adhesive layer (3), and various lidding materials (sample Nα1 to Nα5
) was created. Here, the heat sealing material is ethylene-
5% by weight of calcium carbonate with an average particle size of about 1p was uniformly added to a modified product (registered trademark Dumilan, manufactured by Takeda Pharmaceutical Company Limited) obtained by graft polymerizing acrylic acid to a saponified vinyl acetate copolymer. A dispersed mixture was used. In addition, alkyl and
A phenol resin (trade name: YS Polystar T180, manufactured by Yasushi Oil Co., Ltd.) was used.

The various lid materials thus obtained were punched out using a punching press into a predetermined shape and size corresponding to the opening (lO) of a glass container.

Next, the glass container was filled with water at 40°C, and the lid material was placed at the mouth of the container at a temperature of 200°C and a pressure of 160 kg.
The lids were heated and pressurized for 2 seconds under the conditions of 1/2 seconds, and the lids were directly bonded to the mouth (lO) of the glass container by heat sealing to seal the container. Then, the peel strength of the lid material immediately after heat sealing and the peel strength of the lid material after the sealed glass container was left in an inverted state at 40° C. for 30 days were measured, and are shown in the table below.

Example 2 In this example, as shown in Figure 2, the same heat sealing material layer (2) as in Example 1 was applied on one side of the aluminum foil (1) via an adhesive layer (3). After dry laminating, a solution of alkyl phenol resin diluted in CFC is applied to the surface of the heat sealing material layer (2) and dried at 60°C for 5 minutes to create adhesive properties of various thicknesses. An adhesion aid coating layer (5) was formed, and lid materials (samples 6 to 10) were made.

The lid material thus obtained was subjected to a sealed packaging test in the same manner as in Example 1, and the results are shown in the table below.

Example 3 In this example, as shown in FIG. 2, the same heat sealing material layer (2) as in Example 1 was applied on one side of the aluminum foil (1) via an adhesive layer (3). After dry laminating, a solution of an aromatic petroleum resin (product name Betolite 80, manufactured by Mikuni Resin Chemical Co., Ltd.) diluted in a solvent in advance was applied to the surface of the heat sealing material layer (2), and the heat sealing material layer (2) was heated at 60°C for 50 minutes. By drying for minutes, the thickness is 0. forming an adhesion promoter coating layer (5) having a tackiness of IIUIl;
A lid material (sample NcLil) was made.

The lid material thus obtained was subjected to a sealed packaging test in the same manner as in Example 1, and the results are shown in the table below.

Example 4 In this example, as shown in Figure 2, a special ionomer, namely a monoolefin-unsaturated carboxylic acid copolymer resin, was applied to one side of an aluminum foil (1) via an adhesive layer (3). Metal salt, trade name “Himilan 1702J”
After dry laminating a heat sealing material layer (2) with a thickness of 50 layers consisting of a film of DuPont Mitsui Polychemicals Co., Ltd., melt index 14 g/10 minutes, zinc ion type, a molten coumaron-indene resin ( By applying KUMARON (trade name, manufactured by Ouchi Shinko Kagaku Co., Ltd.) on the surface of this heat sealing material layer (2) by a roll coating method, an adhesion aid coating layer with a thickness of about 0.211B and having adhesive properties is formed. (5) and cover material (sample Nα
12) was created.

The lid material thus obtained was subjected to a sealed packaging test in the same manner as in Example 1.

Comparative Example For comparison, a heat sealing material layer (the same as in Example 1 above but not containing an adhesive adhesion agent) was placed on one side of the aluminum foil (1) via an adhesive layer (3). 2) was provided by dry lamination.

The lid material thus obtained was subjected to a sealed packaging test in the same manner as in Example 1, and the results are shown in the table below.

(Hereinafter, blank space) As is clear from the above table, according to the lid material of the present invention,
Since an adhesive adhesion agent is present on the surface to be thermally bonded to the mouth (lO) of the glass container, the adhesion to the surface of the mouth of the glass container is extremely excellent.
Even after a glass container filled with water is stored upside down for a long time, the adhesive strength of the lid material does not decrease, and the water resistance is good and the sealing performance is excellent.

On the other hand, according to a comparative lid material using a heat-sealing material that does not use an adhesive adhesion agent, if a glass container is stored upside down for a long period of time, the lid material will peel off and the water resistance will deteriorate. It was inferior to

Effects of the Invention As mentioned above, the heat-sealable lid material according to the present invention has an adhesive adhesion agent present on the surface to be heat-bonded to the opening of the hermetically sealed packaging container. During the process, the adhesive adhesion agent present on the surface of the heat sealing material first bonds with the glass surface, and this adhesive adhesion agent acts as a binder between the heat sealing material and the glass surface. During heat sealing, the stress remaining in the polymer main chain in the heat sealing material is alleviated by the bond between the heat sealing material and the glass surface, and the adhesive strength between the heat sealing material of the lid material and the opening surface of the glass container is extremely strong. becomes strong. Therefore, it has excellent adhesion to surfaces that are porous and have relatively weak polarity, such as the mouths of glass containers, etc., and can quickly attach lids to the mouths of sealed packaging containers. Not only can the parts be heat sealed,
Generally, the mouth of a glass container is hydrophilic,
In addition, even when the contents of the container are liquid or viscous, such as alcohol, juice, or jam, it is possible to reliably prevent water from entering the heat-sealed area. The water resistance of the adhesive is significantly increased, the adhesive force decreases little in a water environment, a good adhesive state can be maintained for a long period of time, and the sealing performance is improved under easy-open conditions.

Further, according to the heat-sealing lid material of the present invention, after filling food with food as in the past, a metal cap can be caulked to the mouth of the container, a metal or synthetic resin screw cap can be screwed, or a crown can be screwed onto the mouth of the container. Since the container is not covered or sealed, it is easy to open, and the sealing cost of the hermetically sealed packaging container is reduced because no cap or crown is used.

In addition, there is no resin left at the container mouth when the container is opened (therefore, the appearance of the container mouth after opening is clean, and heat sealing can be performed at a relatively low temperature, making it easier to use the filling and sealing equipment). This has the effect of reducing equipment costs and operating costs, and improving the workability of filling and sealing.

[Brief explanation of the drawing]

Fig. 1 is a partially enlarged cross-sectional view showing a specific example of the product of the present invention;
The figure is a partially enlarged sectional view showing yet another specific example, and FIG. 3 is a partially enlarged sectional view showing yet another specific example. (1)... Aluminum foil, (2)... Heat sealing material layer, (3)... Adhesive layer, (4)... Anti-corrosion coating layer,
(5) Coating layer of adhesion aid having adhesive properties. Patent applicant Showa Aluminum Co., Ltd. Figure 1 Figure 2

Claims (3)

[Claims] (1) A heat-sealing lid material for a hermetically sealed packaging container, characterized in that an adhesive adhesion agent is present on the surface to be thermally bonded to the mouth of the hermetically sealed packaging container. (2) By providing a heat sealing material layer containing an adhesive adhesion agent on one side of the metal foil, the adhesive adhesion agent is applied to the surface to be thermally bonded to the opening of the sealed packaging container. The heat-sealing lid material according to claim 1, wherein the heat-sealing lid material is made to exist. (3) A heat sealing material layer is provided on one side of the metal foil, and the surface of this heat sealing material layer is coated with an adhesive adhesion agent, so that it can be thermally bonded to the mouth of the sealed packaging container. 2. The heat-sealing lid material according to claim 1, wherein an adhesion aid having adhesiveness is present on the surface thereof.