JPS62182066A - 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 Field of the Invention The present invention relates to a sealed package in which a lid is thermocompression bonded to the opening of a rigid container such as a glass container or ceramic container.

BACKGROUND OF THE INVENTION 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 or twist caps. Among these, screw caps are relatively less prone to loosening, but have the drawbacks of being somewhat difficult to open and being expensive. On the other hand, twist caps are relatively easy to open, but have the disadvantage that they tend to loosen. Another method is to caulk an aluminum plate to the opening of the glass container and seal it, but this method also has the drawbacks of being difficult to open and increasing cost.

In addition, conventional glass containers have been sealed with screw caps, twist caps, etc., and have been sterilized with boiling water.
Sterilization is carried out at temperatures of about 10'C to 120°C, but during sterilization under such heating, the cap may become loose, or the cap may become damaged due to impact during transportation. The sealing condition of the glass container is impaired due to deformation of the glass container, resulting in problems such as the formation of mold in the contents, deterioration and rotting of the contents. Some of these problems can be alleviated by increasing the tightening torque of the fittings, or in this case, if the opening is extremely difficult. Becomes If1.

On the other hand, there are glass containers for storing powders such as instant coffee and powdered cream, which are sealed using a laminate material such as aluminum foil or paper that has been coated with a heat sealant in advance. When this type of container is used as a sealed package for a liquid or fluid, the adhesive strength of the heat-sealed portion decreases significantly in a short period of time due to contact with the contents, causing the sealing material to peel off.

Means for Solving the Problems In view of the problems of the prior art as described above, the inventor of the present invention
As a result of extensive research, we have formed a specific resin layer on the open end surface of the glass container and the lid material, respectively, and when the two are roughly combined to form a sealed package, it is possible to We have discovered that a sealed package that exhibits excellent sealing properties over a long period of time, can be sterilized at high temperatures, is easy to open, and has a beautiful appearance at the opening of the glass container after opening, Based on this knowledge, we filed a patent application (Japanese Patent Application No. 57-210339).

As a result of further research, the inventor of the present invention formed a resin layer on the curved surface of the outer periphery of the container opening, and bonded the container and the lid material provided with the resin layer by thermocompression at the curved surface. The inventors have now completed the present invention by discovering that it is possible to obtain a sealed package that can withstand even more severe heat sterilization conditions without sacrificing the above-mentioned advantages.

That is, the present invention provides a device in which a resin layer made of thermoplastic resin is provided on one side of a substrate made of metal foil, plastic film, paper, or a laminate thereof. The present invention relates to a sealed package formed by thermocompression bonding at least the curved surface portion to a rigid rod container provided with a resin layer according to the present invention.

The sealed package of the present invention will be explained below based on FIGS. 1 and 2.

The sealed package of the present invention comprises a curved surface (2) on the outer periphery of the opening of a rigid bar container (1) such as a glass container or ceramic container, and a base material (2) of the lid material (2).
6) After applying the resins (5) and (7) to the container, the container is filled with the contents, and the rigid container and the lid are sealed at least at the curved surface portion (2). obtained by In the present invention, it is essential to provide the resin layer (5) on the container side on the curved surface portion (2) of the outer peripheral edge of the opening and to heat seal this portion. Frontage human face part (4)
If necessary, a resin layer may be provided and heat sealed. In addition, a resin layer may also be provided on the outer surface (3) of the opening and heat-sealed, but if the outer surface (3) is too wide,
If a resin layer is provided on the package, it becomes difficult to open the package.

In the above-mentioned package of the present invention, when the base material bulges during heat sterilization such as boil sterilization and retort sterilization, as shown in FIG. )
Only shear stress is mainly applied to the heat-sealed portion between the resin layer (5) and the resin layer (7) of the lid material, and peeling of the lid material is prevented by the bonding force between the resin layers. On the other hand, if the resin layer is provided only on the top surface (4) of the container opening, when the lid material swells as shown in Figure 3, MvJ will peel off at the joint between the top part and the lid material. The lid material is easily peeled off due to the applied force, and as a result, the sealing properties of the container are impaired. Furthermore, in the case where a resin layer is provided on the outer surface (3) of the container opening and heat-sealed, even if the lid material bulges, only shear stress is mainly applied to the heat-sealed part. Although peeling of the lid material is prevented in the same manner as in the case, it has the disadvantage that it is difficult to open and it is very difficult to heat-seal the outer surface portion (3) uniformly. On the other hand, the method of heat-sealing the curved surface part (2) of the outer peripheral edge of the container opening in the present invention can be easily performed by, for example, bee-sealing using a seal head using a rubber elastic body. I can do it.

Thermoplastic resin may be used as the resin for the resin layer provided on the rigid container, but in consideration of heat resistance when performing boil sterilization, retort sterilization, etc., modified polypropylene alone, modified polypropylene and polyethylene,
A mixed resin with at least one selected from the group consisting of ethylene copolymers, styrene graft copolymers, polyesters, acrylic resins, and epoxy resins is preferred.

More specific examples of these resins are as follows.

Modified polypropylene: Carboxyl groups are introduced into polypropylene by copolymerizing polypropylene with an unsaturated carbonic acid or its anhydride. Examples of the unsaturated carboxylic acid or anhydride thereof include maleic acid, fumaric acid, crotonic acid, acrylic acid, methacrylic acid, maleic anhydride, and itaconic anhydride.

Copolymerization of polypropylene with acid or acid anhydride is effective when the acid value of the resin is 0.1 to 10 (
Either melt-knead W or an acid anhydride and the required amount of a radical initiator in an extruder to give CyKOH/y, or add the acid or acid anhydride and a radical initiator to polypropylene suspended in a solvent. This can be carried out by a known method such as heating and stirring.

Polyethylene: Linear polyethylene, medium density polyethylene, high density polyethylene, etc.

Ethylene copolymer...Ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-imbutyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer ,
Ethylene-propylene copolymer, ionomer, etc.

Styrene graft copolymer...Styrene graph [-polyethylene, styrene craft polypropylene,
Styrene grafted ethylene-vinyl acetate, etc.

Polyester: Linear copolymerized polyester resin is mainly used. This means that 95 to 50 mol% of the acid component must be terephthalic acid residues, and 20 to 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 adipic acid, sebacic acid, other aliphatic digroups, isophthalic acid, orthophthalic acid, diphenyldicarphonic acid, etc. It consists of residues of aromatic dibasic acids, etc., and the remaining 80 to 30 mol% of the glycol component is made up of glycol bases such as 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, neopentyl glycol, etc. Become.

Acrylic resin・・・Polymethyl methacrylate-1・
, polyethyl methacrylate-1 to polyacrylate, methyl methacrylate [·-α-methylstyrene copolymer, etc.

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

When used as a mixed resin, the mixing ratio of modified polypropylene and other resins should be 20 to 95 parts by weight of modified polypropylene and 80 parts by weight of other resins in order to improve heat resistance in boil sterilization, retort sterilization, etc. It is preferable to set the number of hanging parts to about 5 to 5.

In addition, in order to improve the adhesive strength between the resin layer and the container, an adhesion promoter that is usually used for bonding inorganic substances and organic substances, such as a silane coupling agent, a titanium coupling agent, etc., is added to the resin. It may be mixed in an amount of about 1 to 20% by weight (both resin and adhesion promoter as solid content). As such a silane coupling agent, γ-chloropropyl 1 to
Rimethoxysilane, vinyl 1-lichlorosilane, vinyl 1-ethoxysilane, vinyl-tris-β-methoxyethoxysilane, γ-methacryloxypropyl trime 1
-xysilane, β-3,4-epoxycyclohexylethyl 1-rimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyl 1-lyacetoxysilane,
γ-Mercaptopropyl[-rime[~xysilane, γ-
Examples include aminopropyltriethoxysilane, N-β-aminoethoxy-γ-aminopropyltrimethoxysilane, and the like. Examples of titanium-based coupling agents include tetraisopropyl titanate, tetraisopropyl titanate polymer, tetra-butyl titanate-1-, tetrabutyl titanate polymer, and tetrastearyl titanate-1.
~． Examples include 2-ethylhexyl titanate, isopropoxy titanium stearate, titanium acetylacetahenate, titanium lafti 1-, and the like. Also,
These adhesion promoters may be used as a primer layer and formed on the container to a thickness of about 0.1 to 1 μm, and the resin layer (5) may be formed thereon.

Specific examples of the rigid container used in the present invention include glass containers, ceramic containers, metal containers, and the like. The radius of curvature of the curved surface (2) at the outer periphery of the opening of the container is not particularly limited, but is suitably about 0.2 to 2.0 seconds. Further, this curved surface portion may not be a normal curved surface but may be a tapered shape as shown in FIG. The angle of the taper is
There is no particular limitation, but the angle α with the vertical line is 10~
Approximately 20 degrees is appropriate.

To form a resin layer on a rigid container, for example, during the slow cooling process of the glass container immediately after molding, the resin is applied to a predetermined portion of the opening of the glass container and heated to a temperature suitable for each resin, for example, about 80°C. ~250°C, preferably about 100-2
It may be baked at 30'C for about 5 seconds to 10 minutes, preferably about 10 seconds to 5 minutes. Alternatively, the container which is at room temperature after molding may be heated to preferably about 80 to 100° C., the resin may be applied to a predetermined portion of the opening, and the container may be baked in the same manner as described above.

In addition, in order to form a resin layer after providing an adhesion promoter layer on a container, for example, in the slow cooling process of the glass container after molding, approximately 50% of the adhesion promoter is applied to a predetermined portion of the opening of the glass container.
Apply ~10% solution, 100-200' if necessary
After drying for about 5 to 60 seconds at about
C, preferably about 5 seconds to 10 minutes, preferably about 10 seconds to 5 minutes at about 100 to 200°C. Alternatively, the molded container at room temperature can be heated to preferably about 80 to 100°C, and the adhesion promoter can be applied and dried, and the resin can be applied and baked under the same conditions as described above.

Application of the resin, adhesion promoter, or a mixture of both to the opening of the container is easily accomplished by, for example, bringing a sponge roll, rubber roll, sponge sheet, etc. impregnated with these materials into contact with the opening end surface.

The thickness of the resin applied to the rigid container is determined by taking into consideration the unevenness of the container surface, variations in parallelism, etc., but is usually 1 μm.
Above, preferably it is about 3 to 10/im. However, if the surface of the container is very uneven, the thickness may be about 400 μm.

Although it is possible to use a thickness greater than this, no particular improvement in effectiveness is observed.

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 glass container immediately after leaving the forming station, that is, the hot end (hot end)
end) in a glass container at 300-600'C.
By spraying a solution of a metal compound such as tin tetrachloride at a certain level, an extremely thin film of metal oxide such as tin oxide is formed which penetrates into the network structure of the glass, improving the mechanical strength and chemical properties of the glass container. Improves stability. 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.

The base material (6) of the lid material used in the package of the present invention may be metal foil, plastic film, paper, or a laminate of these materials, which is the same as that used as the base material of the equipment in the conventional sealed package for powder. For example, aluminum foil, iron foil, copper foil, stainless steel foil, polyester film, paper, and laminates of these, as well as laminates of aluminum foil and polyolefin films such as polyethylene, and polyester films and polyethylene, etc. Examples include laminates of polyolefin films. In the lid material according to the present invention, it is necessary to provide the base material (6) with a dried fat layer (7). The thickness of the resin layer (7) is desirably 4 μm or more in order to obtain a uniform seal, and for economical reasons, the upper limit is preferably about 60 t1 m. The resin layer (7) may be formed directly on the base material (6), but a resin film may be formed, for example, by dry lamination using a urethane adhesive, or by using an organic titanium or urethane anchor coating agent. It may be bonded to the base material (6>) by a polyethylene extrusion lamination method or the like.The lid material may be provided with a printed layer, an overlay 1-, etc., as necessary, as usual.

In the present invention, the resin for the resin layer (7) of the lid material includes:
Thermoplastic resin may be used, but in consideration of heat resistance during boil sterilization, retort sterilization, etc., at least one of polypropylene and modified polypropylene, or at least one of polypropylene and modified polypropylene and polyethylene, ethylene copolymer, styrene A mixed resin with at least one selected from the group consisting of graft copolymers, polyesters, acrylic resins, and epoxy resins is preferred. A specific example of the above-mentioned resin is the same as that of the resin layer (5) formed in the above-mentioned rigid pot container.

In the present invention, the shape of the lid material is not particularly limited and may be appropriately determined depending on the shape of the container opening, but as shown in FIG. If the curved surface part (2) of the outer periphery and the part in contact with the outer surface part (3) are shaped in advance so that it has a shape as close as possible to the shape of the container opening (hereinafter referred to as a drop-lid cap shape), it is possible to This is preferred because sealing can be done very easily and uniformly.

In order to manufacture the sealed package of the present invention, a rigid pot container provided with a resin layer is sterilized as necessary, and then filled with contents, and then a lid material provided with a resin layer is prepared by a conventional method such as
Heat sealing may be performed at 0°C to 250'C for 1 to 3 seconds. When filling the contents following the resin drying step described above, the container can also be sterilized. As the filling method, aseptic filling, jam at about 90 to 95°C, hot pack method for filling with alcohol at about 65 to 70'C, etc. 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, but it is possible to heat-seal curved surfaces almost completely by heat-sealing with a seal head using a rubber elastic body. can.

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

(i) Even when the sealed package of the present invention is subjected to high temperature sterilization such as boil sterilization or retort sterilization, the seal formed between the container and the equipment will not peel off, and the sealing performance of the container will be impaired. There isn't.

(ii) Sealing is performed at low temperatures and within a short time.

(iii) Since the sealing part has good water resistance, it can be used for a long period of time as a sealed package for storing liquid and fluid substances.Also, uniform sealing is possible regardless of the unevenness of the container.

(iv) The adhesion between the resin obtained in the present invention and the container is
It is so strong that it cannot be heated by short-term 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.

(V) When filling the container with the contents and sealing it with a lid material after forming the resin layer on the container, the heat generated during the drying of the resin layer simultaneously sterilizes the container and sterilizes the container. With heating, a reduction in heat-sealing temperature and a reduction in heat-sealing time are achieved.

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

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples and Comparative Examples.

Example 1 15% modified polypropylene resin modified with maleic anhydride and having an acid value of 10 mg KOH/J was dispersed in toluene.
The dispersion was applied to the top surface of the mouth, the curved surface of the outer peripheral edge, and the outer peripheral side surface of the glass container, and then baked at 230'C for 3 minutes to form a coating film of 1 to 2 μm.

On the other hand, a 50 μm thick unstretched polypropylene film was bonded to the other side of the 50 μm aluminum foil with an epoxy resin coated layer on the − side using a urethane adhesive to form a lid material, and this lid material was dropped to form a lid cap. Molded into a mold.

After filling the glass container with hot water heated to 85°C to 90'C, the lid material was placed on the open end of the glass container, silicone rubber containing silica sand was used as a seal head, and the container was heated at 23 o'c.
Seat 1 to heel on the top surface and the curved surface of the outer periphery of the opening of the glass container under the conditions of 3/cm2 x 2 seconds at 4 x 4, and then immerse the obtained sealed package in hot water at 90'C. 3
Hot water sterilization was performed for 0 minutes.

During sterilization with hot water, the lid material swelled up and the M-sako peeled off on the top surface of the container opening, but no peeling occurred on the curved surface of the outer periphery, and even after cooling, the sealing part was damaged and water leaked. did not occur.

In addition, the bursting strength was measured by blowing compressed air into the sealed package after cooling, and the result was 2.0 to 2.5.
The strength was 3/cm2, and sufficient sealing performance was maintained.

Moreover, the obtained sealed package was easy to open, and the appearance of the opening of the glass container was smooth and beautiful.

Example 2 Oxidized 'IQ/igKO1-1 modified with maleic anhydride
4% by weight of γ-glycidoxypropyl-1-helimethoxysilane was added to a 15% dispersion of a modified polypropylene resin of /9 in toluene, and the liquid was poured outside the mouth of a glass container. A coating is applied only to the curved surface of the periphery.
By baking at 230° C. for 1 minute, a coating film with a thickness of 1 to 2 μm was formed only on the curved surface portion of the outer periphery.

On the other hand, a 50u
An unstretched polypropylene film with a thickness of 30 μm was attached to the other surface of the aluminum foil of No. m via a urethane adhesive, and this was further formed into a drop-lid cap shape to obtain a lid material.

After filling the Noras container with name mushrooms heated to 85 to 95°C, the lid material was placed on the opening of the glass container, and the outer periphery was sealed via silicone rubber at 230°C x 4 kg/cm2 x 2 seconds. Only the curved surface part was thermocompression bonded.

Next, the jqed sealed package was immersed in hot water at 90°C to perform hot water sterilization for 30 minutes.

As a result, during hot water sterilization, the equipment swelled due to the increase in internal pressure, but the seal on the curved surface of the outer periphery did not peel off. Therefore, even after cooling, there was no breakage of the seal or leakage of the contents. The bursting strength was measured by blowing compressed air into the package after cooling, and it was 1.8 to 2.
3'j/cm2, and sufficient sealing performance was maintained.

Moreover, the obtained sealed package is easy to open.

Comparative Example 1 The same modified polypropylene resin dispersion as used in Example 2 was coated only on the top surface of the mouth of a glass container.

Next, using the same H+A as in Example 2, a 230'C x 14. ni'j/cm2X
Heat compression bonding was performed for 2 seconds.

Then, when hot water sterilization was performed in the same manner as in Example 2, blistering of the lid material was observed during hot water sterilization, and peeling of the adhesive portion occurred.

Example 3 A 5% solution of γ-glycidoxypropyltrimethoxysilane was applied to the top surface of the mouth of a glass container and the curved surface of the outer periphery to form a silane coupling agent layer. On top of that, oxidized 5 m'J K modified with maleic anhydride.
A 20% dispersion of a mixed resin consisting of 50 parts by weight of a modified polypropylene resin of OH/g and 50 parts by weight of an epoxy resin dispersed in a mixture of 1-luene and methyl ethyl ketone was applied to the top surface and the curved surface of the outer periphery. , 230'C
It dried in 3 minutes to form a coating film with a thickness of 4 μm.

On the other hand, the thickness is 80 mm with 1~ layer of epoxy resin coated on the - side.
A lidding material was obtained by laminating a blend film of 80% by weight of polypropylene and 20% by weight of high-density polyethylene with a thickness of 40 μm on the other surface of the μm-thick aluminum foil via a urethane adhesive. Further, this lid material was formed into a drop-lid cap shape to form a lid.

After filling the glass container with water, heat the lid to 230°C.
It was thermocompression bonded to the top surface of the opening of the Tekaras container and the curved surface of the outer periphery under the conditions of X 4'j/cm2X 2 seconds.

Next, the sealed package subjected to '+5P' was sterilized by retort using a hot water type boiler/rutter. The conditions for retort sterilization are: (a) 120'C, 1 force, 1 cylinder force, 1.5
9/cm2.30 minutes (b) 120'C, counter pressure 2.5!
J/cm2.30 min (c) 120'C, counter pressure 3.0 to 9
/cm", and 30 minutes. As a result, under all conditions,
There was no damage to the seal or water leakage.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an opening of an example of a rigid rod container used in the present invention, FIG. 2 is a cross-sectional view showing an example of a sealed package of the present invention, and FIG. FIG. 4 is a cross-sectional view of a rigid rod container in which the curved surface of the outer periphery of the opening is tapered. (1)...Rigid rod container body, (2)...Curved surface of the outer periphery of the container opening, (3)...
Outer surface of the container opening, (4)... Top surface of the container opening, (5)... Resin layer of the container, (6)... Base material of the lid, (7)... Lid. The resin layer of the material. (That's all) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) A cover material with a resin layer made of thermoplastic resin on one side of a base made of metal foil, plastic film, paper, or a laminate of these, and a resin layer made of thermoplastic resin on at least the curved surface of the outer periphery of the container opening. A rigid container with layers,
A sealed package formed by thermocompression bonding at least at the curved surface portion.