JPS59103862A - Material for sealed package - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention exhibits excellent sealing properties for a long period of time not only for powder contents but also for liquid contents, enables boil sterilization or retort sterilization, and is easy to open. The present invention relates to materials for sealed packages.

Prior Art Conventionally, liquid or fluid contents such as alcoholic beverages, juices, dressings, mayonnaise, and jams are stored in glass containers and sealed with metal or plastic screw caps, but these are extremely difficult to open. , and the cost is high. Another method is to caulk an aluminum plate to the opening of the glass container and seal it, but this method is also difficult to open and is also expensive. Some glass containers for storing powders such as instant coffee and powdered cream are heat-sealed and sealed using a laminated material such as aluminum foil or paper that has been coated with a heat-sealing agent. When the container is used as a sealed package for a liquid or fluid, there is a drawback that the adhesive strength of the heat-sealed portion decreases significantly within a short period of time due to contact with the contents, resulting in peeling. Special Public Service 1987
Publication No. 8278 discloses a technique of coating the open end surface of a glass container with silane as an adhesion auxiliary material layer.
This method also has problems. That is, if the coating thickness of the adhesion auxiliary material is not sufficient, it will be difficult to achieve uniform heat sealing due to unevenness of the opening of the glass container, variations in parallelism, etc., and if the coating thickness is made sufficiently large, the cost will be extremely high. Become. Furthermore, after filling the glass container with the contents and sealing it,
Although boiling sterilization or retort sterilization is practiced, it is currently difficult to obtain a combination of a glass container and a lid material that can sufficiently withstand sterilization treatment at high temperatures.

Therefore, it is an object of the present invention to exhibit excellent sealing properties even for liquid contents over a long period of time, to enable sterilization treatment at high temperatures, to be easy to open, and to provide an appearance of the opening of a glass container after opening. To provide a combination of a glass container and a lid material for a sealed package that is beautiful and beautiful.

Structure of the Invention As a result of various studies while keeping in mind the current state of the technology as described above, the present inventor has formed a specific resin layer on the opening end surface of a glass container and the lid material, respectively, and has developed a method for bonding both of them. It has been discovered that the above object can be fully achieved when the above objects are combined to form a sealed package, and the present invention has finally been completed.

In the glass container and lid material constituting the sealed package material of the present invention, a resin layer consisting of (a) or (b) shown below is formed. In this case, either one of the two phase fat layers is removed)
and the other one is constructed by (b).

(a) Near-ionomer alone or a mixed resin of the ionomer and at least one selected from the group consisting of polyolefin, ethylene copolymer, styrene graft copolymer, polyester, acrylic resin, and epoxy resin.

More specific examples of these resins are as follows.

Ionomer: An unsaturated carboxylic acid having 3 to 8 carbon atoms such as acrylic acid, methacrylic acid, ethacrylic acid, itaconic acid, maleic acid, etc. is used as the anion part of the ionic bond (crosslinking).

As the cation part, Na, K, Mf, Z
n.

, + + + +
++ ++ ++L+ , Cs
, AI, Cu, Be, Ca, Sr
.

++ Ten+ + Ten++ ++
++ +10Ba, Cu, Cd
, Sn, Pb, Fe, Co.

, ＋＋ ＋＋＋ ＋＋＋ ＋＋
Examples include metal ions having a valence of 1 to B, such as +N+, A, 6, Sc, and Fe.

Polyolefin: polyethylene such as linear polyethylene, medium density polyethylene, and high density polyethylene, polypropylene, polybutene-1, polybutylene, polymethylpentene, etc.

Ethylene copolymer: ethylene-ethyl acrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer,
Ethylene-vinyl acetate copolymer, etc.

Styrene graft copolymers: styrene-crafted polyethylene, styrene-grafted polypropylene, styrene-grafted ethylene-vinyl acetate, etc.

Polyester: Linear copolymerized polyester resin is mainly used. This means that 95-50 mol% of the acid component is terephthalic acid residue, and 20-7 mol% of the glycol component.
0 mol% consists of ethylene glycol residues, and the remaining 5 to 50 mol% of the acid components are aromatic acids such as adipic acid, sebacic acid, other aliphatic dibasic acids, isophthalic acid, orthophthalic acid, diphenyldicarboxylic acid, etc. The remaining 80 to 30 mol% of the glycol components are glycol residues such as 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glyconopeneopentyl glycol, etc. Consisting of

Acrylic resin・・・Polymethyl methacrylate,
Polyethyl methacrylate, polyacrylate, methyl methacrylate-α-methylstyrene copolymer, etc.

Epoxy resin: Contains so-called epoxy resin curing agents such as amines, polyamides, acid anhydrides, phenol resins, butylated melamine formaldehyde resins, butylated urea formaldehyde resins, etc. Molecular weight approximately 400 to 100
00 epoxy resin is good.

(b): Polyethylene alone or polyethylene and polyolefin (excluding polyethylene that is the same as the polyethylene), ethylene copolymer, styrene graft copolymer,
A mixed resin with at least one selected from the group consisting of polyester, acrylic resin, and epoxy resin.

Specific examples of resin (b) are the same as in (a).

According to the research of the present inventor, although it varies depending on the diameter of the glass container, the width of the heat-sealed part, the structure of the lid material, etc., it has been found that the glass container can be opened easily and the glass container can be opened after opening due to the interfacial destruction of both phase fat layers. In order to make the appearance of the department beautiful,
Adhesive strength by 90 peeling is 0.8-8.0k! 7
Approximately 15 mm wide, preferably 1.0 to 2.5 k! 7
It is desirable to have a width of about 15 mm. Generally, in order to reduce the adhesive strength between ionomer and polyethylene,
It is effective to mix polypropylene, polyester, acrylic resin, epoxy resin, etc. to one or both of the two, and conversely, to improve the adhesive strength between the ionomer and polyethylene, it is necessary to mix polyethylene or ethylene copolymer to one or both of the two. Combinations of polymers, styrene graft copolymers, etc. are effective.

In addition, in order to improve heat resistance during boil sterilization (usually at 80 to 95°C for about 80 minutes) or retort sterilization (usually at 120°C for about 30 minutes), ionomers such as linear polyethylene, medium density It is effective to add polyethylene such as polyethylene, high-density polyethylene, polypropylene, polyester, acrylic resin, epoxy resin, etc. To polyethylene, it is effective to add polyethylene, polypropylene, etc. that are different from the polyethylene.

Therefore, if you comprehensively consider the ease of opening, the aesthetic appearance of the opening of the glass container after opening, the heat resistance during boil sterilization or retort sterilization, etc., when adding and mixing other resins with ionomer or polyethylene, It is preferable that the amount of the added resin is about 80% by weight, more preferably about 10 to 60% by weight of the total resin weight as a solid content.

In order to improve the adhesion of the resin layer itself consisting of (a) or (b) above to the glass container, 0.1 to 20% by weight of a silane coupling agent is added to the resin layer. (as a solid content) may be added. Such silane coupling agents include γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris-β-methoxyethoxysilane, γ-methacryloxypropyltrimethoxysilane,
β-3,4-epoxycyclohexylethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β-amine ethoxy -γ-aminopropyltrimethoxysilane and the like are exemplified. Alternatively, the above-mentioned silane-based coupling agent layer is formed as a primer layer to a thickness of 0.1 to 1 μm on the upper end surface of the opening of the glass container, and a resin layer consisting of the above (a) or (b) is formed on top of the silane coupling agent layer as a primer layer. It may be formed.

The present invention will be described in more detail below with reference to embodiments of the present invention shown in the drawings.

In FIG. 1, a resin layer (3) is provided on the upper end surface of the opening of the glass container body (1). The thickness of the resin layer (3) is determined taking into consideration the unevenness of the upper end surface of the opening, the parallelism, etc., but under optimal conditions, it should be at least 1μ.
m or more is required, preferably about 8 to 10 μm. However, if the top surface of the opening has large irregularities, 400
L and N can be used as thick as about μm.

Although it is possible to make the thickness greater than this, no improvement in the effect is observed.

The glass container of the present invention of the type shown in FIG. 1 can be manufactured by applying the above-mentioned resin (a) or (b) to the open end surface of the glass container, for example, during the slow cooling process of the glass container immediately after molding, and heating the glass container to a temperature suitable for each resin. , for example about 80-250°C, preferably about 1
00 to 200°C for about 5 seconds to 10 minutes, preferably 10
It is manufactured by baking for about 5 seconds to 5 minutes. Alternatively, a glass container kept at room temperature after molding is preferably heated to 8
The resin (a) or (b) may be applied to the open end face by heating to about 0 to 100°C, and then baked in the same manner as described above.

In Fig. 2, a silane coupling agent layer (5) is provided as a primer layer on the upper end surface of the opening of the glass container body (1), and a resin layer (3) made of resin (A) or (B) is placed on top of the silane coupling agent layer (5).
) is shown in the glass container of the present invention. In this way, the adhesion between the resin layer (3) and the glass container body (1) is further strengthened.

The glass container of the present invention of the type shown in FIG. 2 can be manufactured by applying an approximately 5 to 10% solution of a silane coupling agent to the open end surface of the glass container, for example, during the slow cooling process of the glass container after molding. After drying at ~200°C for about 5 to 60 seconds, apply the above-mentioned resin (a) or (b) again.
Temperature suitable for each resin, e.g. about 80-250°C1
Preferably at about 100 to 200°C for about 5 seconds to 10 minutes,
Preferably, it is manufactured by baking for about 10 seconds to 5 minutes. Alternatively, a molded glass container at room temperature is preferably
It is also possible to heat it to about 0 to 100° C. and then apply and dry the silane camping agent and apply and bake the resin (a) or (b) under the same conditions as above.

Application of a resin, a silane coupling agent, or a mixture of the two to the open end of a glass container is easily carried out by, for example, bringing a sponge roll, rubber roll, sponge sheet, etc. impregnated with these materials into contact with the open end. .

The base material of the lid material itself for sealing the above-mentioned glass container to form a predetermined sealed package is aluminum foil, which is similar to that used as the base material of the lid material of conventional sealed packages for powder.
Plastic film, paper or a laminate thereof may be used and will not be described in detail, examples of which are as follows. As shown in FIG. 8, the lid material is made of aluminum foil, polyester film, paper, and laminates of these materials, as well as laminates of aluminum foil and polyolefin film such as polyethylene, and polyester film and polyolefin film such as polyethylene. Base material for laminate products, etc. (
7) is a resin layer (9) similar to the resin layer (3) of the glass container.
) is provided. However, if either one of the resin layers on both sides is made of resin (a), the other one is made of resin (b). The thickness of the resin layer (9) is preferably 4 μm or more in order to obtain a uniform seal, and is preferably 60 μm for economical reasons.
It is preferable to set the degree as an upper limit. The resin layer (9) may be formed directly on the base material (7), but the resin layer (9) may be formed directly on the base material (7).
The film (b) may be laminated to the base material (7) by, for example, a dry lamination method using a urethane adhesive or a polyethylene extrusion lamination method using an organic titanate or urethane anchor coating agent. Incidentally, the lid material can be provided with a printed layer (b), an overcoat (2), etc. as required, as in the usual manner.

Incidentally, the glass container used in the present invention may be coated with a metal oxide film in a conventional manner.

That is, in a typical glass container manufacturing process, the diameter of the glass container exiting the forming station, i.e., the hot end
By spraying a solution of a metal compound such as tin tetrachloride into a glass container at 300 to 600°C, an extremely thin film of metal oxide such as tin oxide is formed into the network structure of the glass. This improves the mechanical strength and chemical stability of glass containers. According to research conducted by the present inventors, it has been found that the presence of such a metal oxide film has no effect on the performance of the sealed package.

In order to manufacture the sealed package of the present invention, the above-mentioned glass container is sterilized, filled with contents, and then the lid material is heat-sealed in a conventional manner at 170°C to 220°C for 1 second. Just do it. When filling the contents subsequent to the drying step in [1] above, the glass container can also be sterilized. The filling method is aseptic filling, 90~
A hot pack method of filling jam, alcohol, etc. at about 95°C can be arbitrarily adopted. When a hot pack method is adopted subsequent to the drying process, it is possible to reduce the increase in internal pressure due to the expansion of air in the head space after packaging, thereby reducing sealing defects. Further, when the hot pack method is adopted, the effect of lowering the heat sealing temperature and shortening the heat sealing time is also achieved. The glass container and the lid can be heat-sealed by a known heating method such as heating with a hot plate or high-frequency induction heating.

The sealed package after heat sealing is subjected to high temperature sterilization treatment such as boil sterilization or retort sterilization, if necessary.

According to the present invention, the following effects can be obtained.

(1) Sealing is performed at low temperature and within a short time.

(11) Since the seal portion has good water resistance, it can be used for a long period of time as a sealed package for storing liquid and fluid materials. Furthermore, uniform sealing is possible regardless of the unevenness of the glass container.

(iii) The bond between the resin and the glass container obtained in the present invention has a high strength that cannot be obtained by short-time thermocompression bonding such as heat sealing, and has excellent water resistance.

Furthermore, since this can be done in the slow cooling step that is part of the glass container manufacturing process, the cost is extremely low.

0■) Following the formation of a resin layer on the open end surface of the glass container,
When filling the contents and heat-sealing with the lid, the heat generated during the drying of the resin layer simultaneously sterilizes the glass container, and as the glass container is heated, the heat-sealing temperature decreases and the heat-sealing time decreases. Shortening is achieved.

(V) Since the seal formed between the glass container and the lid of the present invention has excellent heat resistance, the sealed package can be easily subjected to high temperature sterilization treatment such as foil sterilization and retort sterilization.

(Vl) When opening a sealed package, the breakage occurs at the interface between the resin layer on the glass container side and the resin layer on the lid material side, so opening is easy and the appearance of the entrance part of the glass container is smooth and beautiful.

Example I γ-aminopropyltriethoxysilane 1 in an ionomer emulsion (30% solids) containing Na as a cation
% (based on the solid weight of the ionomer) was applied to the open end surface of a glass container and baked at 180° C. for 30 seconds to form a single layer of ionomer with a thickness of 5 to 6 μm.

On the other hand, a 40 μm thick low-density polyethylene film, medium-density polyethylene film, or high-density polyethylene film is attached to the other side of the 50 μm-thick aluminum foil with the printing layer and overcoat layer provided on the − side using a urethane adhesive. They were then glued together to form a lid material.

Next, water was poured into the glass container, a lid material was placed on the top of the glass container so that the ionomer layer and the polyethylene layer were in contact with each other, and heat sealing was performed under the conditions of 200°C x 1 second x 4kVcm2 to form a sealed package. The obtained sealed package was left in an inverted position at room temperature for 6 months, but no decrease in adhesive strength or water leakage due to this was observed in any case.

Furthermore, when the resulting packages were opened by hand, they were easy to open in all cases, and the breakage occurred at the interface between both phase resin layers, so the appearance of the opening of the glass container was smooth and transparent. It was beautiful.

Example 2 A glass container was prepared in the same manner as in Example 1.

On the other hand, a urethane-based anchor coat was applied to the other side of the 50-μm-thick aluminum foil with an overcoat layer on the negative side, and a 15-μm low-density polyethylene (MI7
) and then extrusion coated with low density polyethylene (80% by weight)/styrene grafted polyethylene (50% by weight).
Weight%)/ethylene-propylene rubber (20% by weight)
A lid material was prepared by extrusion coating a blended resin consisting of the following to a thickness of 20 μm.

A sealed package was created in the same manner as in Example 1 using the obtained glass container and lid material, and the durability, unsealability, and appearance after opening were evaluated in the same manner as in Example 1. 1
It was as good as in the case of .

Comparative example 1 The glass container was prepared in the same manner as in Example 1.

The lid material has a thickness of 50 μm with an overcoat layer on the negative side.
An ionomer film with a thickness of 40 μm was bonded to the other surface of the aluminum foil using a urethane adhesive.

When a sealed package was prepared in the same manner as in Example 1 using the obtained glass container and lid, it was difficult to open the package because the adhesive strength at the seam was too high. Furthermore, when the package was forcibly opened, fragments of the ionomer film remained at the opening of the glass container, giving it an unsightly appearance.

Example 8 An ionomer emulsion (solid content 80%) containing Na as a cation and an emulsion (solid content 40%) of low density polyethylene (MI 20) were sprayed with a tin tetrachloride solution at the high temperature end on the open end surface of a glass container. %) (solid content: 1:1) and heated at 230°C for 2 hours.
By baking for 0 seconds, a resin layer with a thickness of 4 μm was formed.

On the other hand, a thickness of 50 μm with an overcoat layer formed on the - side.
A medium-density polyethylene film with a thickness of 40 μm was attached to the other surface of the aluminum foil with a urethane adhesive to form a lid material.

After filling the glass container with seaweed tsukudani heated to 60 to 70°C, the lid material was placed on the glass container and heated to 200°C.
Heat sealing was performed under the conditions of °CXI seconds x 4 kf/cm. Then, the obtained sealed package was heated to 80 to 90°C.
sterilized by boiling in hot water for 80 minutes.

The adhesion and sealing properties of the sealed part of the sealed package after cooling are as follows:
The product was in good condition, easy to open, and the appearance of the opening of the glass container was excellent.

Furthermore, when the sealed package obtained in this example was left in an inverted state for 6 months, no decrease in adhesive strength or deterioration in sealing performance was observed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one example of the glass container according to the present invention, FIG. 2 is a sectional view showing another example of the glass container, and FIG. 8 is a sectional view showing another example of the glass container.
The figure is a sectional view showing an example of the lid material in the present invention. (1)...Glass container body, (3)...Resin layer,
(5)...silane coupling agent layer, (7)...
Base material of lid material, (9) Resin layer of lid material, (b)
...printing layer of the lid material, (to)...overcoat of the lid material. (Above) Figure 1 Figure 2 Figure 3 3 Procedural amendment (voluntary) October 19, 1988 Kazuo Wakasugi, Commissioner of the Patent Office 1 Indication of the case 1981 Patent Application No. 210338 2 Name of the invention sealed Packaging material 3 Relationship with the case of the person making the amendment Patent applicant Toyo Aluminum Co., Ltd. 4 Attorney 5 Date of amendment order Voluntary 6 Section 7 of “Detailed description of the invention” in the specification to be amended Contents of the amendment Attachment Contents of the amendment as attached 1. The phrase "linear polyethylene" on page 7, line 3 of the specification is corrected to "linear polyethylene, low-density polyethylene." 2. For the specification, page 10, line 1, “linear polyethylene” should be replaced with “linear polyethylene, low density polyethylene.”
I am corrected. (that's all)

Claims (1)

[Claims] ■ (1) A glass container with resin layer A formed on the open end surface; (11) resin layer B formed on one side of a base material made of aluminum foil, plastic film, paper, or a laminate of these. A material for a sealed package consisting of a combination of a lid material and a lid material, wherein the resin layers A and B are different from each other,
) A material for a sealed package characterized by being composed of any one of the following: (a) an ionomer alone or an ionomer and a polyolefin, an ethylene copolymer, a styrene graft copolymer, a polyester, an acrylic resin, and an epoxy resin; (b) Polyethylene alone includes polyethylene and polyolefin (excluding polyethylene of the same type as the polyethylene), ethylene copolymer, styrene graft copolymer, polyester, acrylic. A mixed resin with at least one selected from the group consisting of resins and epoxy resins. (1) A glass container in which a silane coupling agent layer and a resin layer A are sequentially formed on the open end surface; and (11) a resin layer B on one side of a base material made of aluminum foil, plastic film, paper, or a laminate of these. A material for a sealed package consisting of a combination with a formed lid material, the resin layers A and B
A material for a sealed package, characterized in that it is composed of one of the following (a) and (b): (a) an ionomer alone or an ionomer and a polyolefin, an ethylene copolymer, or a styrene graft; copolymer,
Mixed resin with at least one selected from the group consisting of polyester, acrylic resin and epoxy resin, (b) Polyethylene alone or polyethylene and polyolefin (excluding polyethylene of the same type as said polyethylene), ethylene copolymer, styrene graft A mixed resin with at least one selected from the group consisting of copolymers, polyesters, acrylic resins, and epoxy resins.