JPH0425323Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a lid material for sealing a glass container filled with jam, coffee powder, powdered cream, juice, etc. [Prior Art] A method of obtaining a sealed container by thermally welding and fixing a lid material to the mouth edge of various containers is a method widely used as a method of obtaining a sealed container of a glass container or a plastic container. However, when the lid material that is heat-welded and fixed to the mouth edge of the container comes into contact with a heating jig during the heat welding process, the contact portion of the lid material may stick to the heating jig. It is required that the container has both a heat-resistant layer that does not cause any damage, and a heat-weldable layer that exhibits heat-welding performance to the rim of the container.
For example, a laminated material consisting of a heat-resistant layer made of aluminum foil and a heat-fusible layer made of thermoplastic resin is most commonly used as a lid material. [Problems to be solved by the invention] By the way, in the lid material made of the conventional laminated material, the thermoplastic resin layer (heat-fusible layer) in the lid material does not have sufficient water-resistant welding properties, so In the case of a glass container where the lid material does not fit tightly to the mouth edge, the sealed container may be inverted, for example, so that the moisture in the filling comes into contact with the lid material, or the sealed container may be in contact with the lid material. If exposed to a high humidity atmosphere, water will seep through the interface between the edge of the glass container and the lid, and the heat-welded part between the edge of the glass container and the lid will usually peel off within a few days. First, it has the disadvantage that the function of the sealed container is impaired. Therefore, in order to improve the water welding resistance of the thermoplastic resin layer in the lid material, the thermoplastic resin insert is coated with a coating agent in which a silane coupling agent is mixed in an organic solvent solution of the thermoplastic resin. Formation of a thermoplastic resin layer (heat-fusible layer) by the method described above may be performed using a thermoplastic resin mixed with a silane coupling agent. In the process of forming the layer, crosslinking of the polymer occurs and the reaction between moisture in the air and the silanol groups of the silane coupling agent progresses, resulting in insufficient improvement in the water welding resistance of the resulting thermoplastic resin layer. Not only that, but there are also disadvantages such as the process of forming the thermoplastic resin layer is not smooth. On the other hand, the lid material for glass containers of the present invention exhibits excellent water welding resistance and is also characterized by being easy to manufacture. [Means for solving the problem] The lid material for a glass container of the present invention includes a heat-resistant base material layer, an olefin resin layer laminated on the heat-resistant base material layer, and a layer laminated on the olefin resin layer. The olefin resin layer is made of an olefin resin having a melt index of 15 or less, and the ethylene resin layer is made of an ethylene-vinyl acetate copolymer. Coalescence, ethylene/acrylic acid copolymer,
It is made of an ethylene resin selected from ethylene/acrylic acid ester copolymers or a mixed resin having the above-mentioned ethylene resin as a main component, and has a melt index of 20 or more. In the lid material for a glass container of the present invention having the above structure, the heat-resistant base sheet member on which the thermoplastic resin layer (heat-fusible layer) in the lid material is formed is such that the lid material is attached to the mouth edge of the glass container. This is the part that comes into contact with the heating jig during heat welding, and materials that can withstand heat sealing temperatures of 200°C or higher are suitable, such as paper, aluminum foil, biaxially stretched polyester film, and composites of these. For example, in the case of simple aluminum foil, the thickness should be 30~ from the viewpoint of heat resistance.
A thickness of about 50μ is preferable. The heat-fusible layer consists of two layers: an olefin resin layer formed on the heat-resistant base sheet and an ethylene resin layer formed on the surface of the olefin resin layer. For example, those formed from polyethylene, polypropylene, ethylene/vinyl acetate copolymer, ethylene/acrylate copolymer, ethylene/acrylic vinegar copolymer, maleic anhydride-modified polyethylene, ionomer, etc. are suitable. Further, the ethylene resin layer formed on the surface of the olefin resin layer has a surface area made of a resin with low melt viscosity, and has thermal welding ability for both the olefin resin layer and the edge of the glass bottle mouth. Ethylene/vinyl acetate copolymer, ethylene/acrylic acid copolymer, ethylene/acrylic acid copolymer, etc. It is formed from an ethylene resin selected from ester copolymers or a mixed resin containing the above-mentioned ethylene resin as a main component. In particular, in the case of a mixed resin whose main component is the ethylene resin, the mixed resin mixed with the ethylene resin may be a vinyl chloride/vinyl acetate copolymer resin or a vinyl silane copolymer resin that has been graft polymerized. In the case of graft-polymerized ethylene resins selected from ethylene/vinyl acetate copolymers, eletin/acrylic acid copolymers, and ethylene/acrylic acid ester copolymers to which the coupling agent is graft-polymerized, water-resistant Since it is a lid material with extremely excellent weldability, it is suitable for use in cases where extremely high water-resistant welding strength is required between the lid material and the edge of the glass container, such as containers filled with youth or alcoholic beverages. It is suitable as Incidentally, a vinyl chloride-vinyl acetate copolymer resin that has been graft-polymerized to be mixed with the ethylene-based resin, an ethylene-vinyl acetate copolymer that has been graft-polymerized with a vinyl-based silane coupling agent, and ethylene-acrylic acid. copolymer, ethylene/
The amount of the graft polymerized ethylene resin selected from the acrylic ester copolymer is 2% by weight or more, preferably 5 to 5% by weight of the ethylene resin.
Extremely good water welding resistance is exhibited within the range of 20% by weight. In addition, vinyl chloride/vinyl acetate copolymer resin, which is graft-polymerized with an amino-based silane coupling agent used as a mixed resin, has a vinyl chloride copolymerization ratio of 10 to 80% and a melting point of 100°C or less. - A vinyl acetate copolymer graft-polymerized with an amino-based silane coupling agent is preferable, for example, N-(2-aminoethyl)3
-Aminopropylmethyldimethoxysilane and 3-
It can be easily obtained by reacting the amino group of a coupling agent such as aminopropyltriethoxysilane with the vinyl chloride/vinyl acetate copolymer. Furthermore, the graft polymerized ethylene resin used as the mixed resin is
Ethylene/vinyl acetate copolymer, ethylene/acrylic vinegar copolymer, ethylene/acrylic acid ester copolymer with an ethylene copolymerization ratio of 7 to 35% and a melting point of 90°C or less, such as vinyltrimethoxysilane, vinyl A graft polymer having an alkoxysilane in its side chain, which is obtained by reacting a vinyl silane coupling agent such as triethoxysilane or 3-methacryloxypropyltrimethoxysilane, is suitable. Furthermore, in order to improve the processability of the resin layer, tackifying polymers such as rosin derivatives, terpene resins, coumaron indene resins, petroleum resins, etc. may be mixed into the ethylene resin layer, and tackifying polymers such as rosin derivatives, terpene resins, coumaron indene resins, petroleum resins, etc. For the purpose of imparting properties, paraffin wax, microcrystalline wax, polyethylene wax, etc. may be added. an olefin resin layer formed of an olefin resin having a melt index of 15 or less;
2. With an ethylene resin layer formed of a resin with a melt index of 20 or more made of ethylene resin or a mixed resin containing ethylene resin as the main component.
In the heat-fusible layer consisting of layers, the olefin-based resin layer provides good heat-welding sealing performance to the lid material, and the ethylene-based resin layer has a sufficiently low melt viscosity that makes it difficult to heat-weld. This sufficiently fills in the irregularities on the surface of the rim of the glass container and improves the water-resistant welding properties of the lid material, but due to the unevenness of the surface of the rim of the glass container and the hardness of the surface, If the thickness of the adhesive layer is less than 20μ, the sealing performance will be poor when the lid material is heat-welded to the rim of the glass container to seal it. When the thickness of the ethylene resin layer, which is made of a mixed resin with a low melt viscosity and a melt index of 20 or more, becomes thicker, the ethylene resin is removed during the process of heat welding the lid material to the rim of the glass container. Since there is a strong tendency to flow out from the welded portion and good sealing performance is impaired, it is preferable that the olefin resin layer has a thickness of about 20 to 50 μm and the ethylene resin layer has a thickness of about 3 to 20 μm. [Example] Hereinafter, the specific structure of the lid material for a glass container of the present invention will be explained using Examples, and the physical properties of the lid material will also be mentioned. Example 1 Zn type ionomer resin [A] [density: 0.94 g/cm ³ , MI: 5.0, MP99°C; manufactured by Mitsui Dupont Polychemical Co., Ltd., registered trademark] was applied to a heat-resistant base sheet made of aluminum foil with a thickness of 50 μm. : Heimiran
1652] was laminated to a thickness of 40μ using a melt extrusion method to form an olefin resin layer, and then, on the surface of the olefin resin layer, ethylene/vinyl acetate copolymer resin [B] [density: 0.95, MI : 150, vinyl acetate content: 25% by weight; manufactured by Mitsui Dupont Polychemical Co., Ltd., registered trademark: EVAFLEX 320] was applied to a thickness of 10 μm using a hot melt coating method using a gravure plate.
By forming an olefin resin layer, a lid material 1 for a glass container, which is an embodiment of the present invention shown in the drawings, that is, a heat-resistant base material layer 2, and a heat-resistant base material layer 2 are formed.
A lid material 1 for a glass container was obtained, which was composed of an olefin resin layer 3 laminated on the olefin resin layer 3 and an ethylene resin layer 4 laminated on the olefin resin layer 3. Example 2 The aforementioned Zn type ionomer resin A was laminated to a thickness of 40 μm by melt extrusion on a heat-resistant base sheet made of aluminum foil with a thickness of 50 μm to form an olefin resin layer, and then the olefin resin layer was laminated to a thickness of 40 μm. On the surface of the resin layer, 90 parts by weight of the ethylene/vinyl acetate copolymer resin B, also described above, and 10 parts by weight of the vinyl chloride/vinyl acetate copolymer resin C, which has been graft-polymerized with 3-aminopropyltriethoxysilane, are mixed. Resin [MI40] was applied to a thickness of 10 μm using a hot-melt coating method using a gravure plate to obtain a lid material for a glass container, which is another example of the present invention. The vinyl chloride/vinyl acetate copolymer resin C is a vinyl chloride/vinyl acetate copolymer [vinyl chloride 86% by weight, vinyl acetate 14% by weight: 100 parts by weight (VYHH) manufactured by Union Carbide Company (UCC) in the United States. This is a graft polymer of a silane coupling agent obtained by kneading a mixture of silane and 10 parts by weight of 3-aminopropyltriethoxysilane at 60°C for 1 hour. Example 3 The above-mentioned Zn type ionomer resin A was applied to a heat-resistant base sheet made of aluminum foil with a thickness of 50μ.
were laminated to a thickness of 40μ by melt extrusion to form an olefin resin layer, and then 80 parts by weight of the ethylene/vinyl acetate copolymer resin B and vinyltrimethoxysilane were applied to the surface of the olefin resin layer. Mixed resin with 20 parts by weight of ethylene/vinyl acetate copolymer resin D [M.
I.40] using a hot melt coating method using a gravure plate.
It was coated to a thickness of 10 μm to obtain a lid material for a glass container, which is yet another example of the present invention. In addition, the ethylene/vinyl acetate copolymer resin D
is the aforementioned ethylene/vinyl acetate copolymer B100.
This is a graft polymer obtained by kneading a mixture of 6 parts by weight of vinyltrimethoxysilane and 1.5 parts by weight of butyl peroxide (BPO) at 90°C for 5 hours. Comparative Example 1 The above-mentioned Zn type ionomer resin A was applied to a heat-resistant base sheet made of aluminum foil with a thickness of 50μ.
were laminated to a thickness of 40 μm using a melt extrusion method to form an olefin resin layer, and a lid material for a glass container was obtained for comparison. After welding the lid material for each glass container obtained in each of the above Examples and Comparative Examples to the rim of a sake glass container with a capacity of 100 cc under heat welding conditions of 220 ° C., 3 Kg/cm ² , and 2 seconds. Furthermore, this was opened and the opening strength (welding strength) per 15 mm width was measured. Results first
Shown in the table. Furthermore, the glass container for sake was filled with water to approximately half the capacity of the container, and then the lid material for each of the glass containers described above was welded under the same conditions as the heat welding conditions. The water-resistant welding property of the lid material for the glass container was determined by standing the glass sealed container in an inverted state and measuring the number of days until water leakage occurred. The results are also listed in Table 1.

[Functions and effects of the invention]

The lid material for a glass container of the present invention includes a heat-resistant base material layer, an olefin-based resin layer made of an olefin-based resin having a melt index of 15 or less and laminated on the heat-resistant base material layer, and the olefin-based resin layer. An ethylene resin with a melt index of 20 or more selected from ethylene/vinyl acetate copolymer, ethylene/acrylic acid copolymer, ethylene/acrylic acid ester copolymer or the above copolymer laminated on the Melt index 20 as main component
It is a lid material for glass containers that is composed of an ethylene resin layer made of the above mixed resin and a heat-fusible layer that exhibits excellent water-proof welding properties. It provides excellent closeness.

[Brief explanation of the drawing]

The figure is a cross-sectional model diagram showing one embodiment of the lid material for a glass container of the present invention. 1... Lid material, 2... Heat resistant base material layer, 3... Olefin resin layer, 4... Ethylene resin layer.

Claims (1)

[Claims for Utility Model Registration] (1) Consists of a heat-resistant base material layer, an olefin resin layer laminated on the heat-resistant base material layer, and an ethylene resin layer laminated on the olefin resin layer. In the lid material for glass containers, the olefin resin layer has a melt index of 1.
It is made of olefin resin of 5 or less,
In addition, the ethylene resin layer is made of ethylene/vinyl acetate copolymer, ethylene/acrylic acid copolymer,
For glass containers, characterized in that it is formed of an ethylene resin selected from ethylene/acrylic acid ester copolymers or a mixed resin having a melt index of 20 or more made of a mixed resin containing the ethylene resin as a main component. lid material. (2) A mixed resin whose main component is ethylene resin is
The lid material for a glass container according to claim 1, which is a mixed resin containing a vinyl chloride/vinyl acetate copolymer resin graft-polymerized with an amino-based silane coupling agent. (3) A mixed resin whose main component is ethylene resin is
A mixture containing a graft polymerized ethylene resin selected from ethylene/vinyl acetate copolymer, ethylene/acrylic acid copolymer, and ethylene/acrylic acid ester copolymer to which a vinyl silane coupling agent is graft polymerized. A lid material for a glass container according to claim 1 of the utility model registration claim, which is a resin.