JPH0649344B2 - Method for manufacturing easy-open lid - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an easy-open lid, and more particularly, to a composite assembly of a metal lid and a resin gripping member. Moreover, the present invention relates to a method for manufacturing an easy-open lid in which the gripping member is firmly attached and fixed to the lid body.

(Prior Art) Conventionally, as an easily-openable lid for a bottle or the like, that is, as a lid that can be opened without using a special opening device, the opening portion is divided by a score, and the opening start portion or an opening piece connected to this is opened. Those provided with a grip portion are widely used. If this grip is made of the same metal as the lid, there is a possibility that a sharp cutting edge may cut a finger. Therefore, it is already known that the grip is made of plastic to prevent this. (For example, Japanese Utility Model Laid-Open No. 55-15885).

As a method for producing this type of easily-openable lid with high productivity, Japanese Unexamined Patent Publication No. 57-178730 discloses that an easily-openable container lid main body is provided with an opening start portion or an opening piece connected to the opening start portion at a molding position. A predetermined amount of plastic is supplied to this molding position, and the plastic is then pressed by a mold under conditions in which the plastic can be molded to form a plastic grasping member integrally with the unsealing start portion or unsealing piece. The manufacturing method of the easy-open container lid is described.

(Problems to be Solved by the Invention) This method has a merit that the integral molding or assembly of the metal lid and the resin gripping member can be performed with a considerably high productivity, but the opening of the resin and the opening start Part and the unsealing piece are joined only on one surface of the unsealing starting part or the unsealing piece, and the thermal bonding between them is performed only by the amount of heat of the melted resin, and insufficient heating at the bonding interface is likely to occur. Therefore, the adhesive strength between the metal portion and the resin portion is likely to fall below the unsealing force, which may cause an accident that the resin gripping member separates from the lid main body during unsealing.

This tendency is due to inserting the metal lid into the injection mold,
The same applies to the case of so-called insert molding in which the gripping member is injection-molded in the form of being integrated with the lid by using resin. In addition, in the case of insert molding, even if resin layers can be provided on both sides of the opening piece of the lid body, sufficient resin coverage cannot be obtained due to cooling with metal, etc. In terms of characteristics, it is not completely satisfactory.

Therefore, an object of the present invention is to manufacture an easily-openable lid composed of a metal lid and a resin gripping member so that the joining and fixing of the both can be performed reliably and firmly and with high productivity. There is a way to provide.

Another object of the present invention is to provide a sufficient resin layer around the unsealed piece of the metal lid, and to sufficiently bond the metal and the resin at a high temperature, thereby improving the strength and appearance of the joint. An object is to provide a method of manufacturing an easy-open lid having excellent characteristics.

(Means for Solving the Problems) According to the present invention, a pair of scores each of which is composed of a top plate portion and a skirt portion continuous with the top plate portion and which extends from the skirt portion across the top plate portion, and is divided by the scores. A step of manufacturing a metal lid main body having a peeling start tongue piece, a holding frame body, and an attachment base portion extending outward from a part of the frame body,
A facing piece extending inwardly of the frame body in a direction opposite to the mounting base portion from a portion of the frame body on which the mounting base portion is provided;
A step of integrally molding a gripping member composed of a hinge portion provided between the facing piece and a frame body with a thermoplastic resin; and a mounting base portion of the gripping member and a bent facing piece. With a tongue piece for starting peeling of the lid main body, heat-bonding the tongue piece to the base portion and the opposing piece, and further heat-sealing the base portion and the opposing piece around the tongue piece. A method for manufacturing an easily-openable lid is provided.

(Operation) According to the present invention, the resin gripping member is molded independently of the metal lid main body, and the resin gripping member and the metal lid main body are joined and fixed by the gripping member molding step. Is performed in a separate step by the means detailed below.

First, in FIG. 1 showing a metal lid body used in the present invention, the lid body 1 is composed of a top plate portion 2 and a skirt portion 3 connected to the top plate portion 2 and extends from the skirt portion 3 across the top plate portion 2. There are provided a pair of scores 5 and 5, a peeling section 4 defined by the scores, and a peeling start tongue piece 6 provided integrally with the score and projecting outward from the skirt section.

2A and 2B showing the resin-made gripping member 10 used in the present invention, the gripping member 10 includes a gripping frame body 11.
A mounting base 12 extending outward from a part of the frame 11, and a mounting base 12 extending inward of the frame 11 from a portion of the frame in which the mounting base 12 is provided. Opposing piece 13 extending in the same direction in the opposite direction, and facing piece 13 and frame 1
1 and a hinge portion 14 provided between
The gripping member 10 is manufactured by injection-molding a thermoplastic resin in a mold having a corresponding shape, or press-molding a resin sheet in a softened state. The facing piece 13 can be bent 180 degrees via the thinned hinge portion 14, and has a shape and dimensions that substantially overlap the mounting base 12 when bent 180 degrees.

In FIGS. 3-A, 3-B and 3-C for explaining the heat-bonding fixing process between the metal lid body 1 and the resin-made gripping member 10, in step A (FIG. 3-A), gripping is performed. Member 1
The tongue piece 6 for starting peeling of the metal lid body 1 is positioned on the mounting base 12 of 0. Then, in step B (FIG. 3-B), the facing piece 13 of the gripping member 10 is bent about 180 ° and is superimposed on the mounting base 12 and the tongue piece 6. Finally, in step C (FIG. 3-C), the above-mentioned laminated structure is thermocompression-bonded by the hot press mechanism 20 to thermally bond the tongue piece 6 to the base portion 12 and the facing piece 13 and the base portion 12 and the facing piece 13. And heat fusion around the tongue piece 6 are performed to obtain the final product. The mounting base 12 and the facing piece 13 have a larger shape and size than the tongue piece 6, and the tongue piece 6 is heat-bonded to the resin forming the base 12 and the facing piece 13 on both sides thereof. The edge portion will be protected by the resin.

(Effect of the Invention) According to the present invention, the resin gripping member 10 is attached to the metal main body 1
By manufacturing in a shape independent of that, it is possible to manufacture a shape and size set in advance with high accuracy and high productivity, and to join and fix the metal lid 1 and the resin gripping member 10 together. However, the tongue piece 6 is sandwiched by the mounting base 12 and the facing piece 13, and under the condition that a sufficient amount of heat and pressure necessary for thermal bonding are applied, and the tongue piece 6 and the base 12 are further attached. And heat bonding with the facing piece 13 and the base 12
Since it is performed by heat fusion between the opposite piece 13 and the tongue piece 6 around the tongue piece 6, there is an advantage that the joining and fixing of the two are firmly and reliably performed and the appearance of the joining and fixing portion is also good.

(Example) In FIG. 4 showing an example of a cross-sectional structure of a tongue piece of a metal lid main body used in the present invention, the lid main body 1 includes a metal base 31 and a protective coating layer 32a formed on both surfaces thereof and It consists of 32b. As the metal base 31, sheet-shaped or foil-shaped surface-untreated steel (black plate), surface-treated steel, light metal such as aluminum is used. As surface-treated steel, chemical treatment such as phosphoric acid treatment and chromic acid treatment on the steel substrate; chemical conversion treatment such as electrolytic chromic acid treatment; electrolytic plating treatment such as electrolytic tin plating, electrolytic zinc plating, electrolytic chrome plating; molten aluminum Examples include those that have been subjected to hot dipping treatment such as plating and hot tin plating.

The protective coating layers 32a and 32b are coatings having excellent adhesion and corrosion resistance to metal materials, for example, thermosetting resin coatings such as phenol-formaldehyde resin, furan-formaldehyde resin, xylene-formaldehyde resin. , Ketone-formaldehyde resin, urea-formaldehyde resin, melamine-formaldehyde resin, alkyd resin, unsaturated polyester resin, epoxy resin, bismaleimide resin, triallyl cyanurate resin, thermosetting acrylic resin, silicone resin, oil resin, or heat Plastic resin coatings such as vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer partially saponified, vinyl chloride-maleic acid copolymer, vinyl chloride-maleic acid-vinyl acetate copolymer, acrylic copolymer Coalesced, saturated polyester Butter, and the like are used alone or in combination of two or more.

The protective coating layers 32a and 32b may also serve as an adhesive coating layer for the thermoplastic resin forming the holding member 10. The adhesive coating varies depending on the type of the liner, but in the case of an olefin resin, for example, an oxidized polyolefin, an acid-modified polyolefin, or a coating obtained by mixing these with the coating resin is used. Further, in the case of vinyl chloride resin, vinyl chloride paint, acrylic paint or the like is used.

Instead of using the protective coating layers 32a and 32b in the form of a single adhesive coating layer, a multi-layer coating film of an undercoat layer of protective coating and a top coat layer of adhesive coating may be used.
Alternatively, the adhesive coating layer may be applied only to the tongue piece 6 and a different protective coating layer may be provided to the other portions.

A sealing liner or packing 7 can be provided on the inner surface side of the top plate portion 2 of the lid body 1 for the purpose of sealing. The liner 7 can be formed by an in-shell mold of low density polyethylene, ethylene propylene copolymer, soft vinyl chloride resin or the like, or a packing made of a laminate of foamed plastic and resin, paper, metal foil or the like. 7 may be applied by adhesion.

In FIGS. 5-A to 5-C showing several examples of the shape of the tongue piece 6, the tongue piece 6 has a rectangular shape (FIG. 5-A) and a rounded tip shape (the fifth shape).
-B) and a dovetail shape (Fig. 5-C). The shape shown in FIG.
It will be understood that when the two and the facing piece 13 are heat-sealed around the tongue piece 6, the bond strength (pull-out strength) becomes particularly high.

The resin gripping member 10 used in the present invention may be any thermoplastic resin such as low-, medium- or high-density polyethylene, polypropylene, ethylene-propylene copolymer,
Olefinic resins such as poly-4-methylpentene-1;
Styrene-butadiene copolymer, styrene resin such as ABS resin; manufactured by polyacetal resin, nylon resin, polyester resin, acrylic resin, vinyl chloride resin. Olefin-based resins are preferable in terms of price.

In FIG. 6 showing an example of a cross-sectional structure of a preferable resin-made gripping member 10, this gripping member 10 is composed of a laminated body of an olefin resin base 41 and a modified olefin resin surface layer 42. The modified olefin resin surface layer 42 is provided on the side of the surface 15 where the facing piece 13 and the mounting base 12 overlap each other when the facing piece 13 is bent 180 degrees. As the modified olefin resin, maleic anhydride grafted polyethylene, maleic anhydride modified polypropylene, ethylene-acrylic acid ester copolymer, ethylene-vinyl acetate copolymer, ionomer and the like, carboxylic acid, carboxylic acid ester, carboxylic acid 5 to 400 mmol / 100 of carbonyl group based on acid anhydride, carboxylate, etc.
Olefin-based resins, which are contained at a concentration of g resin, are used, and they are particularly excellent in thermal adhesiveness to a metal or a coating film on a metal, and are characterized in that good thermal adhesiveness is possible even at a relatively low temperature. Thus, the use of this laminated structure of the holding member has an advantage that the tongue piece 6 and the base portion 12 and the facing piece 13 can be thermally bonded well. Further, if the surface layer 42 has a low-temperature heat-sealing property, fusion or heat bonding between the surface of the base portion 12 and the surface of the facing piece 13 can be efficiently performed.

In the present invention, the mounting base 12 of the grip member 10 may be flat, or may have a shallow recess 16 for defining the bonding position of the tongue 6 as shown in FIG. Good. The depth of this recess 16 must be smaller than the thickness of the tongue 6.

Mounting base 12 of tongue piece 6 and gripping member 10 and facing piece 13
The thermal bonding with and is performed by heating and pressing one or both of them. For example, by heating the tongue piece 6 by high frequency induction heating, thermal bonding between the two is effectively performed.
Further, thermal bonding can be performed also by pressing the overlapping portion of both with a heat seal bar. The former means is a preferable means for firmly performing heat adhesion between metal and resin within a short time, and the latter means not only heat adhesion between metal and resin but also heat fusion between resins. Is also done. When the high frequency induction heating means and the ultrasonic irradiation sealing method are used together, heat adhesion between the resin and the metal and fusion bonding between the resins can be efficiently performed at their contact interfaces.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a metal lid main body used in the present invention, and FIG. 2 is a view showing an example of a resin gripping member used in the present invention, where A is a plan view thereof and B is A. FIG. 3-A, FIG. 3-B and FIG. 3-C are views for explaining the heat bonding step of the metal lid body and the resin gripping member. FIG. 4 is a cross-sectional view showing an example of the cross-sectional structure of the metal lid main body, and FIGS. 5-A, 5-B and 5-C are some examples of the shape of the peeling start tongue piece. 6 is a perspective view showing a cross-sectional structure of a preferred example of the resin gripping member, and FIG. 7 is a perspective view showing an example of the surface structure of the mounting base of the resin gripping member. Is. 1 is a metal lid main body, 2 is a top plate portion, 3 is a skirt portion, 4 is a peeling portion, 5 is a score, 6 is a peeling start tongue piece, 10 is a resin gripping member, and 11 is a gripping frame. , 12 is a mounting base, 13 is a facing piece, 14 is a hinge, and 20 is a heating press mechanism.

Claims (1)

[Claims] 1. A pair of scores each comprising a top plate portion and a skirt portion continuous with the top plate portion and extending from the skirt portion across the top plate portion, and a tear-off initiation tongue segment defined by the scores. Step of manufacturing metal lid main body, holding frame body, mounting base portion extending outward from a part of the frame body, and frame portion from the portion of the frame body provided with the mounting base portion Of integrally forming a gripping member made of a thermoplastic resin, the gripping member including a facing piece that extends inwardly of and opposite to the mounting base and a hinge portion provided between the facing piece and the frame body. And the attachment base of the gripping member and the bent opposing piece sandwich the tongue piece for starting peeling of the lid body, heat bond the tongue piece to the base and the opposing piece, and further face the base portion. And a step of heat-sealing the piece around the tongue piece, and a method for producing an easily-openable lid, comprising: