JPH0232964A - Heat sealable lid material for use on seal packaging container - Google Patents

Abstract

PURPOSE:To contrive the improvement of sealability of a seal packaging container under an easy-to-open condition by rendering a titanium or aluminum coupling agent present on an opening of a seal packaging container and the surface to be heat sealed. CONSTITUTION:A heat sealable layer 2 containing a titanium or aluminum coupling agent is provided on the one side of an aluminum foil 1 with an adhesive agent 3 interposed therebetween, whereby such coupling agent is made present on an opening 10 of a seal packaging container such as glass container and the surface to be heat sealed. An anticorrosion coating layer 4 is provided on the other side of aluminum foil 1. The heat sealable layer 2 has on its surface a coating layer 5 containing the titanium or aluminum coupling agent, whereby such coupling agent is made present on the opening 10 of the glass container and the surface to be heat sealed.

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;
Due to its relatively weak polarity and poor adhesion, in recent years it has been developed to use carboxyl-modified saponified ethylene-vinyl acetate copolymer, which has improved adhesion, as a heat-adhesive resin for lid materials. (for example, Japanese Patent Application Laid-Open No. 80-17804)
(See Publication No. 2). 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. However, after heat sealing, water may enter the adhesive area.1. In this case, there was a problem in that the adhesiveness was significantly reduced and the lid material was easily peeled off from the adhesive 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. 81-9181) 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.

Furthermore, conventionally, a heat-sealing lid material (for example, JP-A-Sho Go-58
549 Publication), and a heat sealing lid material comprising a heat sealing material layer made of an ionomer composition containing a silane coupling agent applied to one side of a metal foil through an ionomer layer is already known (see Japanese Patent Publication No. 549). For example, JP-A-61-104
(See Publication No. 971). Such silane coupling agents act to chemically bond inorganic materials and organic materials, but silane coupling agents are particularly effective when one of the inorganic materials is a silica-based inorganic material. It was effective.

I. In general, heat sealing materials contain a large amount of calcium carbonate, talc, etc., and the chemical binding effect is not very strong against such calcium carbonates and talc. Therefore, there was a problem that the water resistance was poor and the adhesive strength was reduced in a water environment.

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 object, the heat-sealing lid material for a hermetically sealed packaging container according to the present invention is provided with a titanium coupling agent or a titanium coupling agent or It is characterized by the presence of an aluminum coupling agent.

Here, there are two ways to make the titanium coupling agent or the aluminum coupling agent exist on the surface of the lid material to be thermally bonded.

(1) First of all, by providing a heat sealing material layer containing a titanium coupling agent or an aluminum coupling agent on one side of the metal foil as the base material of the lid material, the opening of the sealed packaging container When a titanium coupling agent or an aluminum coupling agent is present on the surface to be thermally bonded.

(II) Second, 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 a titanium coupling agent or an aluminum coupling agent, thereby forming a sealed packaging container. When a titanium coupling agent or an aluminum coupling agent is present on the surface to be thermally bonded to the mouth of the

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
/! , preferably 20 to 60 cuts.

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 seven resins, ethylene-vinyl acetate has 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. A modified product obtained by graft polymerizing a carboxyl group-containing unsaturated compound to a saponified copolymer (see, for example, JP-A-80-178042), and an ionomer (see, for example, JP-A-61-54587) are used. is desirable.

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

That is, melt index 1-800g/10
(according to ASTM 1238-657) and an ethylene content of 50 to 97% by weight, preferably 6
0 to 82% by weight of an ethylene-vinyl acetate copolymer is saponified to produce a saponified product having a hydroxyl group equivalent of 100 to 3000 g/1 equivalent, preferably 200 to 1000 g/1 equivalent, and then this saponified product is It is obtained by graft polymerizing an unsaturated compound containing a carboxylic acid group.

Here, examples of the carboxylic acid group-containing unsaturated compound 7 include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride, and citraconic acid. The obtained graft polymer, that is, the carboxyl modified product of the saponified ethylene-vinyl acetate copolymer, has an acid equivalent of 50,000 g/1 equivalent or less, preferably 1,000 to 30,000 g/1 equivalent as a whole.

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, ethacrylic 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 salts such as zinc, magnesium, and calcium. Examples include ionically crosslinked resins, ie, ionomer resins, obtained by neutralization with similar metal 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 to 18%, and the degree of ionization is several % to 90%.

Examples of the titanium coupling agent include tetraisopropyl titanate, tetraisopropyl titanate polymer, tetrabutyl titanate, tetrabutyl titanate polymer, tetrastearyl titanate, 2-ethylhexyl titanate, dibutyl titanate polymer isobroboxy titanium stiprate, titanium At least one titanium compound selected from the group consisting of acetylacetonate and titanium lactate is used.

Furthermore, as the aluminum coupling agent, acetalkoxyaluminum diisopropylate or the like is used.

As the titanium coupling agent or the aluminum coupling agent, two or more of these compounds may be mixed.

The thickness of the heat sealing material layer is usually 5 to 300 cm, preferably 20-10 mm/ff.

By providing a heat sealing material layer containing a titanium coupling agent or an aluminum coupling agent on one side of the metal foil of the lid material in (1) above, the surface to be thermally bonded to the mouth of the sealed packaging container When these coupling agents are present, the content of these coupling agents in the heat sealing material layer is 0.05 to 20% by weight, preferably 0.1 to 10% by weight.

In addition, a heat sealing material layer is provided on one side of the metal foil of the lid material in (n) above, and the surface of this heat sealing material layer is coated with a titanium coupling agent or an aluminum coupling agent, so that it can be used for sealed packaging. When these coupling agents are present on the surface to be thermally bonded to the mouth of the container, the thickness of the coating layer of these coupling agents is 0. O1 to 30, preferably 0.1 to 1 Op.

In the cases of (I) and (II) above, when the content of the titanium coupling agent or aluminum coupling agent is less than 0.05% by weight, and the thickness of the coating layer of these coupling agents is less than o, otp. In both cases, the amount of these coupling agents is too small, and the chemical bonding effect (coupling effect) of the coupling agent is not sufficiently exerted, resulting in poor water resistance of the heat-sealed joint and damage to the water environment. Since the adhesive strength decreases at the bottom,
Undesirable.

Conversely, when the content of titanium coupling agent or aluminum coupling agent exceeds 20% by weight, or when the thickness of the coating layer of these coupling agents is 3.
When it exceeds 0p, it is not preferable because not only the adhesive force in a water environment does not change much but also the cost increases.

In addition, when a heat sealing material layer containing a titanium coupling agent or an aluminum coupling agent is provided on one side of the metal foil of the lid material in (1) above, these coupling agents may be present on the surface of the heat sealing material layer. It bleeds, diffuses to the surface side, and becomes concentrated. In this case, these coupling agents are preferably present in an amount of 1% or more on the surface to be heat-sealed at the mouth of the sealed packaging container, 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 (II) above with a titanium coupling agent or an aluminum coupling agent, it is necessary to thermally bond it to the mouth of the sealed packaging container. 100% of these coupling agents are present on the surface to be heat-sealed. Therefore, it is important to adjust the thickness of the coating layer, that is, the amount of titanium coupling agent or aluminum coupling agent present on the surface to be heat-sealed. , which is easier than the case (1) above.

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 p1, preferably 0.5 to 30 p1, and the inorganic compound is added to 30 parts by weight or less, usually 0.1 parts by weight, per 100 parts by weight of the thermoadhesive resin.
~20 parts by weight, preferably 1 to 10 parts by weight are mixed.

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.

To provide a heat sealing material layer on one side of the metal foil, a heat sealing material containing or not containing a titanium coupling agent or an aluminum coupling agent as described above is processed into a film in advance, and this film is placed on the metal foil. This can be bonded to one side of the metal foil using an adhesive such as a two-component reactive adhesive based on polyester incyanate, or by extruding a melted heat sealing material onto one side of the metal foil using an extruder. It is sufficient to connect them directly.

Further, when coating the surface of the heat sealing material layer with a titanium coupling agent or an aluminum coupling agent, it may be performed by, for example, a spray method, a brush coating 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, in the lid material shown in Fig. 1, a heat sealing material layer (2) containing a titanium coupling agent or an aluminum coupling agent is provided on one side of an aluminum foil (1) via an adhesive layer (3). Accordingly, these coupling agents are present on the surface to be thermally bonded to the opening (10) of a sealed packaging container such as a glass container. The other side of the aluminum foil (1) is coated with an anti-corrosion coating layer (
4) has been applied.

In addition, the lid material shown in Fig. 2 has a heat sealing material layer (2) provided on one side of an aluminum foil (l) with an adhesive layer (3) interposed therebetween, and a heat sealing material layer (2) is provided on the surface of this heat sealing material layer (2). By applying a coating layer (5) of a titanium coupling agent or an aluminum coupling agent, the opening (10
), these coupling agents are present on the surface to be thermally bonded. The other side of the aluminum foil (1) is similarly coated with an anticorrosive coating layer (4).

Furthermore, the lid shown in Figure 3 has almost the same structure as the lid shown in Figure 1, but in order to prevent corrosion of the aluminum foil (1) by the contents, one side of the aluminum foil (1) is An intermediate layer (7) made of polyethylene film is provided,
A heat sealing material layer (2) containing a titanium coupling agent or an aluminum coupling agent is provided on this intermediate layer (7) via an adhesive layer (3), and an aluminum foil (1) is provided on the intermediate layer (7).
A printed layer (6) is provided on the other surface, and an anticorrosive coating layer (4) is further provided on that surface.

According to the heat-sealing lid material of the present invention, since the titanium coupling agent or the aluminum coupling agent is present on the surface to be thermally bonded to the opening (10) of the hermetically sealed packaging container, it can be sealed in a water environment. This is thought to be due to the following reasons: there is little decrease in adhesive strength, a good adhesive 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 or 1000H 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, immediately after heat sealing, the molecular segments of the heat sealing resin undergo thermal movement and their orientation is disordered, making it difficult for hydrogen bonds to occur and adhesion is primarily due to van der Waals forces. After heat sealing, the functional groups are gradually arranged on the glass surface over time, form hydrogen bonds with the silanol groups on the glass surface, and the adhesive strength gradually increases.

However, when the contents of a glass container are liquid or viscous, the glass surface at the container mouth is hydrophilic, so water molecules tend to get wet, forming a multi-molecular layer of water molecules, which makes heat sealing difficult. The van der Waals forces at the bond are weakened and the hydrogen bonds are also broken, resulting in a significant decrease in adhesive strength.

On the other hand, according to the heat-sealing lid material of the present invention, a titanium coupling agent or an aluminum coupling agent is present on the surface to be thermally bonded to the mouth of the glass container, and these coupling agents are , which acts to chemically bond inorganic materials and organic materials, but in particular, titanium coupling agents or aluminum coupling agents are carbonates of calcium commonly contained in heat sealing materials. It has a strong chemical bonding effect (coupling effect) to inorganic materials other than silica such as silica and talc, and therefore, it is possible to chemically bond the resin component in the heat sealing material layer with these inorganic materials. Not only does it create a strong bond, but during heat sealing, the titanium coupling agent or aluminum coupling agent present on the surface of the heat sealing material firmly bonds to the glass surface, so that the heat sealing material of the lid material and the mouth of the glass container are The adhesion to the surface becomes very strong, and therefore water intrusion into the adhesion interface can be reliably prevented, greatly increasing the water resistance of the heat-sealed bond.

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

Example 1 As shown in Fig. 1, various amounts of titanium coupling agents (registered trademark BlenAct T
A heat sealing material layer (2) consisting of a heat sealing material film with a thickness of 50 mm mixed with TS (manufactured by Ajinomoto Co., Inc.) is bonded to an adhesive layer (3).
) to make various lid materials (sample Nos. 1 to 5). Here, as the heat sealing material, a modified product obtained by graft polymerizing acrylic acid to a saponified product of ethylene-vinyl acetate copolymer (registered trademark Dumilan, manufactured by Takeda Pharmaceutical Company Limited) is used, with an average particle size of Approximately 1 slice of calcium carbonate (5% by weight) was uniformly dispersed and mixed.

The various lid materials thus obtained were punched out using a punching press into a predetermined shape and size corresponding to the opening (10) 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 180 kgf.
The lids were heated and pressurized for 2 seconds under the conditions of 1000 ml/piece, and these lids were directly bonded to the mouth (10) of the glass container by heat sealing to seal the container.

Then, for these sealed containers, 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 upside down at 40°C for 30 days were measured, and the results were obtained. 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 a titanium coupling agent (registered trademark Blen Act TTS, manufactured by Ajinomoto Co., Inc.) diluted in CFC in advance was applied to the surface of the heat sealing material layer (2), and
By drying at C for 5 minutes, coating layers (5) of titanium coupling agent having various thicknesses were formed, and lid materials (Sample 1!L8-10) were made.

Example 3 In this example, as shown in FIG. 1, a 3% by weight aluminum cup was placed on one side of the aluminum foil (1) via an adhesive layer (3) in the same manner as in Example 1 above. A heat sealing material layer (2) made of a heat sealing material film with a thickness of 507 ff7 mixed with a ring agent (registered trademark BlenAct AL-M, manufactured by Ajinomoto Co., Inc.) is bonded via an adhesive layer (3), and a lid is formed. A material (sample Nα11) was prepared.

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 1702"
(Mitsui DuPont Polychemical Co., Ltd., melt index 14 g / 10 minutes, zinc ion type) film was dry laminated with a heat sealing material layer (2) of 50 cm thick, and then a titanium cup diluted in CFC in advance was attached. By applying a solution of a ring agent (registered trademark PrenAct TTS, manufactured by Ajinomoto Co., Inc.) to the surface of the heat sealing material layer (2) by a roll coating method, a thickness of approximately 0.211y is applied.
A coating layer (5) of the titanium coupling agent of I was formed, and a lid material (sample strain 12) was prepared.

Lid materials obtained in Examples 2 to 4 above (sample Nci, 6 to
12), a sealed packaging test was conducted in the same manner as in Example 1, and the obtained results are shown in the table below.

Comparative Example 1 For comparison, 5% by weight was applied to one side of the aluminum foil (1) via the adhesive layer (8) in the same manner as in Example 1 above.
Thickness 50IH mixed with silane coupling agent (product name A-187, manufactured by Nippon Unicar Co., Ltd.)! ! A heat sealing material layer (2) consisting of a heat sealing material film of
The lid material was made by joining the two pieces together via the .

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

A sealed packaging test was conducted on the lid materials obtained in Comparative Example 1 and Comparative Example 2 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 a titanium coupling agent or an aluminum coupling agent is present on the surface to be thermally bonded to the mouth (10) of the glass container, the coupling action of these coupling agents causes the surface of the mouth of the glass container to be bonded. It has very good adhesion, and the adhesive strength of the lid material does not decrease even after a glass container filled with water is stored upside down for a long time, and has good water resistance and excellent sealing performance.

On the other hand, according to the comparative lid material that uses a heat sealing material that does not contain a titanium coupling agent, the lid material peels off when the glass container is stored upside down for a long time, resulting in poor water resistance. Met.

Effects of the Invention As mentioned above, the heat-sealing lid material according to the present invention has a titanium coupling agent or an aluminum coupling agent present on the surface to be thermally bonded to the mouth of the sealed packaging container. Therefore, due to the coupling action of these coupling agents, the resin components in the heat sealing material layer and the inorganic materials such as calcium carbonate and talc contained in the heat sealing material are chemically strongly bonded. At the same time, during heat sealing, these titanium coupling agents or aluminum coupling agents present on the surface of the heat sealing material firmly bond to the glass surface, resulting in adhesion between the heat sealing material of the lid material and the mouth surface of the glass container. The power becomes very strong. Therefore,
It has excellent adhesion to surfaces that are porous and have relatively weak polarity, such as the mouths of glass containers, and can quickly attach lids to the mouths of hermetically sealed packaging containers. Not only can it be heat-sealed, but the mouth of the glass container is generally hydrophilic, and it can also be used when the contents of the container are liquid or viscous, such as alcohol, juice, jam, etc. , it is possible to reliably prevent water from entering the heat-sealed bonded area, greatly increasing the water resistance of the heat-sealed bonded area, reducing the decrease in adhesive strength in a water environment, and maintaining a good bonding condition for a long time. It 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.

Furthermore, there is no resin left at the container mouth when the container is opened, so the appearance of the container mouth is clean after opening, and heat sealing can be performed at a relatively low temperature, making it easy to install filling and sealing equipment. This has the effect of lowering 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 titanium coupling agent or aluminum force/twisting agent @ Figure 1 Figure 2

Claims (3)

[Claims] (1) A heat-sealing lid material for a hermetically sealed packaging container, characterized in that a titanium coupling agent or an aluminum coupling 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 a titanium coupling agent or an aluminum coupling agent on one side of the metal foil, the surface to be thermally bonded to the mouth of the sealed packaging container is coated with a titanium coupling agent or The heat-sealing lid material according to claim 1, characterized in that an aluminum coupling agent is present. (3) A heat sealing material layer is provided on one side of the metal foil, and a coating layer made of a titanium coupling agent or an aluminum coupling agent is provided on the surface of the heat sealing material layer, so that the opening of the sealed packaging container can be sealed. and the surface to be thermally bonded,
Claim 1 characterized in that a titanium coupling agent or an aluminum coupling agent is present.
The heat-sealing lid material described.