JPH0455564B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a method for manufacturing can-like container lids, and specifically relates to a method for manufacturing can-like container lids, specifically for beverage coffee cans, soup cans, edible oil/adjustment cans, motor oil cans, and various canned goods. In a lid that constitutes a can-like container such as a container, and is made by injection molding mainly of synthetic resin instead of metal, the handle for opening the can is attached to the lid at the same time as the lid body is formed. This invention relates to injection molding technology that attaches to the main body and integrates these parts.

[Prior Art] The present inventors have made intensive studies on the lid of the container, which is mainly made of synthetic resin as described above.

An example of the manufacturing method is, for example, a method in which a base material having resin layers on both sides of Al foil is mounted in an injection mold in advance, and resin is injected onto one side of the base material. be.

When molding the lid, it is also possible to bond and mold the base material and a resin sheet previously made by injection molding using an adhesive, but this method of post-adhesion increases the number of steps; There are various disadvantages such as increased cost, molded products are prone to peeling due to heat history such as retort treatment, poor drop strength of the manufactured product, and food hygiene problems due to the use of adhesive.

On the other hand, according to the simultaneous injection molding, the molten injected resin is thermally fused to the resin layer of the base material.
It has high adhesive strength and does not peel off due to heat history such as after retort processing, and has high product drop strength.Furthermore, it reduces costs by reducing the number of steps.
Furthermore, since no adhesive is used, a long-term storage container with excellent food hygiene properties can be obtained, which satisfies various requirements for a can-like container (lid).

During simultaneous injection molding, it was difficult to obtain high-precision products because the base material that had been inserted into the injection mold in advance sometimes misaligned during the process. They succeeded in eliminating this difficulty by inserting and fixing it into a guide stripper attached to the (Japanese Unexamined Patent Publication No. 59-215842).

However, on the other hand, the above-mentioned simultaneous injection molding caused a somewhat difficult problem regarding easy opening of the lid.

That is, the can-like container is required to be easy to open in order to drink or take out the contents inside the can-like container. The can-like container is intended to be opened without the need for auxiliary tools such as a can opener.

However, in the simultaneous injection molding, since the molten resin is injected onto the surface of the base material, the handle for opening the can made of the injected resin also comes into close contact with the base material.
The end of the handle cannot be lifted upward. Therefore, lift the handle and press down on the tip of the handle where the can begins to open, breaking the base material,
It becomes impossible to open the can along the score part (cutout part) provided for opening the can where the surface of the base material is exposed.

Therefore, it was proposed to provide a treatment layer (release layer) on the surface of the base material at the position of the handle part by applying a release ink or the like in advance to make the seal easier to open. Tokukai Akira
60-23154).

However, problems such as the increase in the number of printing ink application steps and the accuracy of the application position have arisen.

Therefore, a resin handle is manufactured separately, and in a later process, it is attached to the panel of the lid main body.
It was proposed to attach using methods such as ultrasonic welding (for example, Japanese Patent Application No. 61-4237 and No. 61-132825).

An example of this method will be explained with reference to FIGS. 20 to 23. In these figures, reference numeral 1 denotes a lid main body, and as described above, the lid main body 1 is formed by molding a base material 2 into an injection mold (Fig. (not shown) and is manufactured by injecting resin onto it. 3 in the figure is the injected resin layer.

Further, in these figures, numeral 4 denotes a score section, which is configured in a band-like and track-like shape, and as shown in the cross-sectional view of FIG. At the exposed surface, the lid is opened along this score section 4, as described above.

A part of the injection resin layer 3 located inside the score section 4 serves as a pedestal section 5, and a boss 6 is erected on the upper part of the pedestal section 5.

A handle portion 7 as shown in FIG. 21 is attached to this boss 6.
Attach by ultrasonic welding.

That is, through holes 8, 8 are provided at the end (tip) on the left side in the drawing of the handle portion 7, and the second
As shown in Figure 0, the boss 6 and the through hole 8,
8 [Fig. 20A], a part of the boss 6 (head part) protrudes from the through holes 8, 8 [Fig. 20B], and the head part of the boss 6 is melted by ultrasonic waves. Then, the molten resin is filled into the through holes 8, 8 [FIG. 20C], and the tip of the handle 7 is ultrasonically welded to the lid body 1.

However, in this method, the lid main body part 1 and the handle part 7
This poses problems such as the positioning and attachment (joining) required for attachment, the need for an ultrasonic welding device, and the fact that the handle portion 7 is easily scratched during welding.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for manufacturing a can-like container lid that eliminates the drawbacks of the prior art.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] and [Operation] The present invention provides a lid body that is thermally bonded to the body of a can-like container, and which has a gas barrier base material on both or one side of which is made of a heat-meltable resin. Injecting a thermoplastic resin or a thermoplastic resin composition (injection molding material) onto the surface of the layered lid material (multilayer base material) opposite to the body side, excluding at least the score portion for opening the can. When manufacturing a lid body that integrates the resin layer (injection resin layer) formed by the method and the fixing part of the separately molded resin handle for opening the can, the fixing part of the handle is prepared in advance. The injection molding material is placed near the injection port of the mold for molding the injection resin layer, and the other part is surrounded by a belt-shaped frame mold, and the injection molding material is applied to the opposite surface of the multilayer base material. A can, characterized in that the injected resin layer is formed by injection molding on the fixed part side of the handle part, and only the fixed part of the handle part is integrated with the injected resin layer. The invention consists in a method of manufacturing a container lid.

To explain the structure of the present invention and its effects together with its representative examples, one injection mold (injection resin layer molding mold) has a resin injection port with a through hole at its tip (fixing part). Aligning the through holes of the handle part, the handle part is installed (inserted) in one of the injection molds in advance, and the stratum base material is installed in the other injection mold. After clamping these molds, when resin is injected into the cavity from the resin injection port through the through hole to the back side of the resin handle, the injected resin is laminated on the surface of the other layer base material, While forming the injection resin layer of the lid main body, the fixing part of the handle is attached on top of the injection resin, so that the handle and the lid main body can be integrated.

In this way, at the same time as the injection resin layer is formed on the lid body, the handle can be fixed to the injection resin layer using the injection resin, and the lid body and handle can be integrated. Compared to the case where the handle part is molded separately and the handle part is melted by ultrasonic vibration and fixed to the lid main body part, the process is simplified and the working time is shortened. In addition to being unnecessary, there is no risk of scratching the handle part that would occur during welding, and if a release layer such as conventional printing ink is used, the release layer may shift or a process for forming the release layer is required. There was a problem, but it can be resolved.

Next, the manufacturing method of the present invention will be described in further detail based on drawings showing examples thereof.

As shown in FIG. 5, the injection resin layer forming mold 9
An injection port (gate) 11 connected to a resin inflow path 10 is provided in the upper part of the mold (on the left side in the figure).

As will be described in detail later, the molten injection molding material is injected into the cavity from the injection port 11 through the resin inflow path 10.

Three molds 12, 13, and 14 are attached to the cavity side surface of the mold 9 for forming the injection resin layer in a positional relationship as shown in FIG. That is, as shown in FIG. 1, a circular belt-shaped frame mold 12 is disposed on the outermost side, and a horseshoe with a belt-shaped cross section is placed inside the mold 12 and spaced apart from the upper part of the mold 12. A mold 13 having a similar shape is disposed inside the mold 13, and is spaced apart from the mold 13, has a similar shape to the mold 13, and extends inward at its upper end. A mold 14 having an upper end portion is disposed such that the height of the upper end thereof matches that of the mold 13.

On the cavity side surface of the injection resin forming mold 9 equipped with such molds 12, 13, 14,
The plan view is shown in Fig. 2, and Fig. 2 A-A is shown in Fig. 3.
A resin handle portion 15 formed in a horseshoe-shaped frame body, whose enlarged line sectional view is shown and a side view is shown in FIG.
As shown in FIG. 1, the upper end of the fixing part 16 is brought into contact with the inner surface of the circular mold 12, and the main body part 17 is interposed between the molds 13 and 14, and the molds are installed in advance. I'll keep it.

The distal end portion (fixing portion) 16 of the resin handle portion 15 is provided with an elliptical through hole 18 as illustrated in FIG. 1 and the like.

As shown in FIG. 5, when the handle portion 15 is attached to the mold 9 for forming an injection resin layer, the through hole 18 is positioned at the injection port 11.

The fixing part 16 of the resin handle part 15 has a step between it and the handle main body part 17, as shown in FIG. Make sure to leave a gap in between.

As shown in FIG. 5, a lid body 20 is set on the cavity side surface of the other injection mold 19 on the right side in the figure.

Next, as shown in FIG. 6, the mold is clamped.

After the mold clamping, as shown in FIG. 7, injection molding material (hereinafter also simply referred to as injection resin) is injected into the cavity 21 from the injection port 11 through the resin inflow path 10 of the mold 9 for injection resin layer molding. Inject 22.

As mentioned above, the through hole 18 of the resin handle 15
is located at the injection port 11 position, the molten injection resin 22 flows within the through hole 18, and further,
It flows toward the back side of the fixed part 16 of the handle part 15.

The injection resin 22 that has flowed to the back side is transferred to the innermost mold 1 as shown in FIG.
The liquid flows into the inside of the mold 4, and also flows from side to side on the back surface of the fixed part 16 of the handle part 15, and also flows into the area surrounded by the circular mold 12 and the mold 13 as shown in the figure.

In this way, the fluidized injection resin 22 is transferred to the surface of the multilayer base material 23 of the lid main body 20 (the surface opposite to the body side of the can-like container) on the back surface of the fixing portion 16 of the handle portion 15.
The injection resin 22 that has flowed into the mold 14 is also laminated on the surface of the multilayer base material 23 inside the mold 14, and is simultaneously surrounded by the circular mold 12 and the mold 13. The injection resin 22 that has flowed even in the areas where the molds 12 and 13 are formed is also laminated on the surface of the multilayer base material 23 in the areas surrounded by the molds 12 and 13.

Next, after cooling, the mold is opened and the molded product (lid)
By taking out the plan view in Fig. 8 and the plan view in Fig. 9
A lid body 24 as shown in the sectional view taken along the line B-B in FIG.
can be obtained.

As shown in FIG. 9, the parts of the molds 12, 13, and 14 are not laminated with injection resin (layers), and are exposed parts (grooves) of the multilayer base material 23.

From the injection resin (layer) 22 laminated as before inside the circular mold 12, the panel portion 2 of the lid body 24 is formed.
The injection resin layer No. 5 is formed, and the handle portion 1
The through hole 18 of the fixing part 16 of No. 5 is filled with the injection resin 22, and the fixing part 16 of the handle part 15 is
The fixed portion (tip portion) 16 of the handle portion 15 is fixed to the injection resin layer 22 of the panel portion 25 by the injection resin 22 laminated in the gap between the rear surface and the surface of the lower multilayer base material 23 .

As shown in FIG. 9, the end portion of the main body portion 17 of the handle portion 15 is separated from the multilayer base material 23 due to the fixation of the tip portion 16 thereof (as shown in the figure, the end portion is not necessarily will not be raised).

In the embodiment shown in FIGS. 5 to 9, the lid main body 20 is laminated in advance in a separate process by partially protruding the resin layer 26 from the multilayer base material 23 at the peripheral end of the multilayer base material 23. Then, the resin layer 26 is attached to the flap part 2 of the main body part 20 in a Γ-shaped cross section including the peripheral end part.
7 is set at 19 in the other injection mold and the injection molding is performed. Above the resin inflow path 10 (and injection port 11) of the injection resin layer molding mold 9, a resin inflow path 28 and a gate 29 for forming the resin layer 26 of the flap portion 27 are further provided. The flap portion 27 may be formed simultaneously with the formation of the panel portion 25 by injection molding using the multi-point gates 11 and 29.

The panel portion 25 and the flap portion 27 are separated from each other via the circular strip-shaped outer groove 30 formed in the circular mold 12 as described above.

An example of the opening of the body 24 will be described with reference to FIG. 9.

As shown in FIG. 9, hold the end of the main body part 17 of the resin handle part 15 for opening the can provided inside the panel part 25 upward as shown by the arrow in the figure. increase.

Then, the fixing part 16 of the handle part 15 is pushed down in the direction opposite to the arrow, and when the handle part 15 is pulled up, the multilayer base material 23 of the score part 30 is cut, and the outer periphery of the score part 30 is cut. edge 3
The lid body 24 is opened along the line 2.

FIG. 17 is a plan view of the lid 24 after opening;
FIG. 18 is a sectional view taken along the line CC in FIG. 17.

As shown in FIGS. 17 and 18, upon opening, the injection resin layers 22 on the inside and outside where the handle portion 15 was located are also removed from the panel portion 25.

The mold 13 is installed to prevent the injection resin layer 22 laminated inside the mold 13 and the circular mold 12 from adhering to the outer peripheral surface of the main body 17 of the handle portion 15.

The mold 14 disposed inside the mold 13 is
Similarly, this is to prevent the injection resin 22 flowing into the mold 14 from adhering to the inner peripheral surface of the main body 17 of the handle 15.

However, due to the molds 12, 13, 14,
As shown in FIG. 1 and as described above, the handle portion 15 can be set in advance in the mold 9 for injection resin forming.

At the time of opening, as shown in FIG.
3 is preferable because it makes it easier to insert a finger between the main body part 17 of the handle part 15 and the multilayer base material 23 when opening the lid body 24, and it becomes easy to open.

Next, two or three modified examples of the present invention are shown in FIGS. 11 to 1.
This will be explained according to Figure 6.

As shown in FIGS. 1 to 9, an example is shown in which a frame body with a horseshoe-shaped interior is used as the handle portion 15, but in the present invention, as shown in FIG. Alternatively, the illustrated handle portion 34 without the hollow portion may be used.

A cross-sectional view of injection molding using the handle part 34 is shown below.
It is shown in FIG.

The injection molding in this case is carried out in the same manner as in the embodiment shown in FIGS. 1-9. However, in this case,
The innermost mold 14 used in the previous embodiment is not used, and the injection resin 22 does not flow into the mold 14.

The embodiment shown in FIG. 12 shows a U-shaped resin handle portion 35 in the example shown in FIGS. 1 to 9 without the fixing portion 16.

In this case, the method of injection molding and fixing the handle is as follows:
Similar molds 12, 13 as shown in FIGS. 1 to 9,
14, the handle part 35 is attached to the injection resin layer forming mold 9, the injection resin 22 is injected, and the upper part of the handle part 35, the inside of the handle part 35, and the outer peripheral part of the handle part 35 are The injection resin is made to flow and the injection resin layer 22 of the panel section 25 is laminated,
Both end surfaces of the handle portion 35 and the vicinity thereof are fixed to the injection resin layer 22 by the injection resin 22.

The example shown in FIG. 13 is a U-shaped resin handle 36 in order to increase the fixing strength by making the fixing part of the handle larger than that in FIG. 12. Perform injection molding as in the example. The resin handle portion 35 shown in these FIGS. 12 and 13,
A cross-sectional view of injection molding using No. 36 is shown in FIG. In addition, the resin handle portion 34 shown in FIG.
FIG. 16 shows a cross-sectional view of the situation of injection molding using. FIG. 14 is a plan view of a lid 24' using the resin handle 36 shown in FIG. 13.
In this example, the fixing part 38 extending outward from the upper part of the main body part 37 of the resin handle part 36 is attached to the panel part 25'.
It is fixed to the injection resin layer 22 of.

Next, FIG. 10 shows a cross-sectional view of an example of the structure of the multilayer substrate material 23 used in the present invention.

The multilayer substrate material 23 has resin layers 40 and 41 that can be thermally melted (thermally bonded) on both sides of an intermediate gas barrier substrate 39, respectively.

The gas barrier base material 39 needs to have so-called gas barrier properties that do not allow oxygen or impurities to pass through.

Examples of the gas barrier substrate 39 used in the present invention include metal foils, as well as the following sheets and films.

Examples of metal foil include aluminum foil (hereinafter simply referred to as aluminum foil), and the present invention particularly provides
There is a can-like container lid made of this aluminum foil as a gas barrier base material 39. Examples of other gas barrier substrates 39 include sheets and films made of saponified ethylene-vinyl acetate copolymers, polyvinylidene chloride, polyamide, polyacrylonitrile, and the like.

Can-like container lid 24 (including 24') according to the present invention
As mentioned above, this gas barrier base material 39
The aluminum foil, etc. The thickness of the gas barrier substrate 39 is desirably 50 microns or less, preferably 9 to 30 microns.

In addition, by having such a thickness, complete incineration is possible, and the incineration calories are 5000 ~
It can be reduced to 6000kcal/Kg and solve the problem of empty can disposal.

The can-like container according to the present invention has its flap portion 27 attached to the body portion 43 of a can-like container 42 by thermal bonding, as shown in FIG. 19, for example. This body portion 43 also has a similar resin layer surface.

In FIG. 19, 44 indicates a bottom cover body.

The heat-meltable resin layer of the multilayer base material 23 on the side to be attached to the body 43 of the lid body 24 is the outer layer 41, and the resin layer laminated by injection molding and the multilayer base material 23 on the side to be heat-sealed are the outer layer 41. If the heat-meltable resin layer is the outer layer 40, the other layer base material 23 according to the present invention may include the inner and outer layers 40, 4 as shown in the above embodiments.
1 is preferably formed. This inner layer 4
Due to the presence of 0, a lid with high adhesion can be formed by thermal fusion with the injection resin layer.
However, this inner layer 40 can also be omitted.

As the resin constituting the resin layers 40 and 41, resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, which are melted by heat, are used.

Both the inner and outer layers 40 and 41 may be made of the same resin, or may be made of different resins.

The resin layers 40 and 41 are connected to the gas barrier base material 3
9, it can be formed with or without an adhesive resin layer such as an adhesive or a film-like hot melt adhesive.

The thickness of the resin layers 40 and 41 is preferably 100 μm or less on one side for the same reason as the gas barrier base material 39 described above.

Various materials can be used for the injection molding material 22 used in the present invention, including synthetic resins such as polyolefin-based synthetic resins such as polypropylene and ethylene-propylene copolymer, which have excellent heat resistance against high temperatures during retort sterilization. An example is resin.

An inorganic filler can also be mixed into this injection molding material. Mixing an inorganic filler has the following advantages.

The dimensional stability of the can-like container is improved and the shrinkage rate is reduced, which is advantageous.

Improved heat resistance and increased heat distortion temperature, making it advantageous for retorting.

Burned calories are reduced and incinerators are not damaged, which is advantageous for empty can disposal.

It can provide rigidity, which is advantageous in handling the product.

Heat conduction becomes good, which is advantageous for retorting.

Cost can be reduced.

As the inorganic filler, any material widely used in the field of synthetic resins and rubbers may be used. These inorganic fillers are preferably inorganic compounds that have good food hygiene properties, do not react with oxygen and water, and do not decompose during kneading and molding. Examples of the inorganic filler include compounds such as metal oxides, their hydrates (hydroxides), sulfates, carbonates, and silicates;
It is broadly classified into these double salts and mixtures thereof. Typical examples of such inorganic fillers include aluminum oxide (alumina), its hydrates, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide, zinc oxide (zinc white), red lead, and lead such as white lead. oxide, magnesium carbonate,
Calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, talc, glass fiber, glass powder, glass beads, clay,
diatomaceous earth, silica, wollastonite, iron oxide,
Antimony oxide, titanium oxide (titania), litobone, pumice powder, aluminum sulfate (stone bone, etc.),
Examples include silica zirconium, zirconium oxide, barium carbonate, dolomite, molybdenum disulfide and iron sand. Among these inorganic fillers, those in powder form preferably have a diameter of 20 microns or less (preferably 10 microns or less). In addition, fibrous materials have a diameter of 1 to 500 microns (preferably 1 to 300 microns) and a length of 0.1 to 6 mm.
(preferably 0.1 to 5 mm). Furthermore, it is preferable that the diameter of the flat plate is 30 microns or less (preferably 10 microns or less). Among these inorganic fillers, those in the form of flat plates (flake) and those in the form of powder are particularly suitable.

In addition, various additives such as pigments may be added to the injection resin.

Resin handle parts 15 and 3 used in the present invention
The same resin as the injection molding material 22 is used for the resins 4 to 36.

[Example] Next, examples of the present invention will be shown.

Example 1 Using a Toshiba IS-50A (302) injection molding machine, the 8th
The can-like container lid shown in the figure was molded.

Showa Aroma MK400C [manufactured by Showa Denko,
The resin handle shown in Fig. 2 manufactured using propylene/ethylene block copolymer with MCR of 10.0 g/10 min was placed in an injection resin forming mold [moving mold] equipped with metal as shown in Fig. 1. Insert it into the specified position in advance. On the other hand, the other injection mold [fixed mold] is fitted with a lid part in which a flap part is formed by injecting the same resin as above onto a multilayer base material.

The multilayer base material is aluminum foil and ethylene propylene block copolymer [MFR1.1 ethylene content 9wt%]
A multilayer base material was used, consisting of layers laminated on both sides. The thickness composition of the aluminum foil and the resin layer on both sides is resin (inner layer)/
Aluminum foil/resin (outer layer) = 30μ/15μ/70μ.

After the mold was clamped, the same resin as above was injected from the gate of the movable mold.

The cylinder temperature was 240°C and the injection pressure was 60Kg/cm ² .

A can-like container lid in which the handle portion and the lid main body were integrated was obtained.

Example 2 A can-like container lid was obtained in the same manner as in Example 1 except that a two-point gate was used in Example 1.

A can-like container was obtained in which the handle part and the lid part including the flap part were integrated.

Example 3 A mold was made in the same manner as in Example 1, except that a wood composition made by adding 40% charcoal to Showaromer MK400C was used, and the cylinder temperature was 260°C and the injection pressure was 80Kg/ ^cm2 . After tightening, injection molding was performed to obtain a can-like container lid.

A can-like container lid in which the handle portion and the lid body were integrated was obtained.

Although the invention made by the present inventor has been specifically explained based on the examples above, the present invention is not limited to the above examples, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say.

[Effects of the Invention] (1) In the conventional method of molding the lid body and handle in separate processes and then joining the handle to the lid body through secondary processing such as ultrasonic welding, it is difficult to align the two. It took a long time to join the panels, which caused a slight lack of productivity, and when the handle part and the panel part were joined together, scratches were generated on the outside surface of the panel part due to heat etc., resulting in defects. For example, by inserting the handle into the mold of an injection molding machine in advance and injecting the injection molding material, the handle can be attached to the lid body at the same time as the injection resin layer of the lid body is formed. The process time was shortened, production efficiency was improved without the need for special equipment such as an ultrasonic device, and the appearance of the handle part was also good.

(2) A method of molding the lid body and the handle at the same time by injection molding was proposed by the inventor of the present applicant. It has also been proposed to provide an easily removable treatment layer by applying printing ink, etc., in order to smooth the surface, but there are some difficulties in the position, accuracy, and method of forming the treatment layer, and in some cases, the position of the treatment layer may be difficult to form. There were cases where the handle part did not peel off properly due to misalignment, but the insert molding of the present invention can solve this problem, and also eliminates the pre-processes for forming the processing layer, such as printing with printing ink, thereby reducing the process. It can be simplified.

(3) When putting the can-like container (lid) on the market, in addition to cost considerations, it is important that the container has good retort characteristics when retort processing is performed after the body is filled with beverages or other contents. There are many requirements that the lids of various can-like containers must meet, such as being strong enough to withstand the fall of the product, and ensuring that there are no food hygiene issues if the contents of the can are food. Furthermore, it is required that the can be easily opened for ingestion and removal of the contents of the can, such as for drinking.

According to the present invention, it was possible to provide a can-like container lid of excellent quality that satisfies these requirements.

[Brief explanation of drawings]

1 to 19 show one embodiment of the present invention, FIG. 1 is a principle diagram showing the relationship between the mold, the handle, and the floor of the melt-injected resin, and FIG. 2 is a plan view of the handle. , FIG. 3 is an enlarged sectional view taken along line A-A in FIG.
Figure 4 is a side view of the handle, Figure 5 is a cross-sectional view explaining the injection molding process before mold clamping, Figure 6 is the same cross-sectional view after mold clamping, Figure 7 is a cross-sectional view explaining the injection process, and Figure 8 is the main body. A top view of the lid according to the invention, FIG. 9 is a sectional view taken along the line B-B in FIG. 8,
FIG. 10 is a cross-sectional view of the structure of the multilayer base material, and FIGS. 11 to 13 are plan views showing other examples of the handle portion, respectively.
Fig. 14 is a plan view of the lid using the handle shown in Fig. 12, Figs. 15 and 16 are explanatory sectional views showing other examples of the injection process, and Fig. 17 is the lid after opening. A plan view, FIG. 18 is a sectional view taken along line C-C in FIG. 17, FIG. 19 is an overall view of the can-like container, and FIGS. 20A to 20 are
D is an explanatory cross-sectional view of the conventional process (Fig. 21D
21 is a plan view of the handle portion, FIG. 22 is a plan view of the lid body, and FIG. 23 is a sectional view taken along line FF in FIG. 22. DESCRIPTION OF SYMBOLS 1... Lid body part, 2... Base material, 3... Injection resin layer, 4... Score part, 5... Pedestal part, 6... Boss, 7... Handle part, 8... Through hole, 9 ... Mold for injection resin layer molding, 10 ... Resin inflow channel, 11 ...
Injection port (gate), 12...Mold, 13...Mold,
14... Mold, 15... Resin handle, 16...
Fixing part of resin handle, 17... Resin handle main body, 18... Resin handle through hole, 19... Other injection mold, 20... Lid main body, 21...
Cavity, 22...Injection molding material (injection resin),
23...Multilayer base material, 24...Lid, 24'...Lid, 25...Panel portion, 25'...Panel portion, 2
6...Resin layer, 27...Flap part, 28...Resin inflow path, 29...Gate, 30...Score part, 31...Groove, 32...Score part outer peripheral edge,
33... Resection part, 34... Resin handle part, 35...
...Resin handle, 36...Resin handle, 37...
...Resin handle body part, 38...Resin handle fixing part, 39...Gas barrier base material, 40...Heat-meltable resin layer, 41...Heat-meltable resin layer, 42... Can-like container, 43...can-like container body,
44...Bottom lid body.

Claims (1)

[Claims] 1 The body side of a lid that is thermally bonded to the body of a can-like container and has a heat-meltable resin layer on both or one side of a gas barrier base material (hereinafter referred to as multilayer base material) A resin layer (hereinafter referred to as an injection resin layer) formed by injecting a thermoplastic resin or a thermoplastic resin composition (hereinafter referred to as an injection molding material) on the opposite side of the can, excluding at least the score portion for opening the can. When manufacturing a lid body that integrates a fixing part of a separately molded resin handle for opening a can, the fixing part side of the handle part is injected into a mold for injection resin layer molding in advance. The injection molding material is attached to the vicinity of the exit, and the parts other than the fixing part are surrounded by a strip frame mold, and the injection molding material is injected to the fixing part side of the handle part on the opposite surface of the multilayer base material. A method for manufacturing a can-like container lid, characterized in that the injection resin layer is formed by the injection molding, and only the fixing portion of the handle portion is integrated with the injection resin layer.