JPH0684176B2 - Metal-plastic composite lid and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composite lid made of metal and plastic, which is suitable as a sealing lid for a container that stores a drug solution such as an injectable drug solution or a drip solution. More specifically, the present invention relates to a manufacturing method thereof, and more specifically, a metal inner lid having an opening at the center of the top plate and a fixing skirt around the opening, and a sealing engagement with the opening, and the top plate. The present invention relates to a composite lid composed of a plastic outer lid closely attached to the same and a method for producing the same.

(Prior Art) Various types of sealing outer lids for containers for storing drug solutions such as injectable drug solutions and drip drug solutions have been proposed.

For example, in JP-A-59-142949, a metal shell having a top plate having a hole portion, a skirt portion hanging down from the peripheral portion of the top plate, and a plastic plate-like body for closing the hole portion are disclosed. The plastic plate-like body is formed with a thin-walled portion that defines a removable portion for opening inside the hole, and the removable portion has a knob portion protruding outward. Are integrally formed, and the plastic plate-shaped body is formed by press molding so that the peripheral portion sandwiches the outer surface and the inner surface of the hole edge portion of the top plate, and the peripheral portion is the top plate. There is described a cap characterized in that it is in close contact with the peripheral portion of the hole portion.

The cap disclosed herein is also intended as a hermetically-sealed lid for a liquid medicine container, in which a plastic plate-like member is arranged in a state in which a hole formed in a top plate of a metal shell is closed. Since the plate-like body is formed so that the peripheral portion thereof sandwiches the outer surface and the inner surface of the hole edge portion of the top plate, the metal shell and the plastic plate object are closely contacted with each other at the hole edge portion. There is no rattling or gap between
It is evaluated as a hermetically-sealed lid for a drug solution container because it has a structure in which dust and miscellaneous bacteria do not easily enter during steam sterilization, cooling, or storage.

However, in the cap described above, the plastic plate-like body is only in close contact with the metal shell so as to sandwich the outer surface and the inner surface only at the peripheral portion of the hole portion, and the metal shell and the plastic plate-like body adhere to each other. Since it does not mean that it has a temporary function as a sealing lid during normal steam sterilization processing and storage,
It is hard to say that the product is completely satisfactory in terms of hermeticity when it is transported.

Further, in Japanese Utility Model Publication No. 54-128859, a lid body 3 is composed of a closed rubber stopper 1, a metal base 2 and a plastic lid body 3.
In the vial for medicine, which is opened with a fingertip to make a hole in the central portion of the top surface of the metal base 2, insert the protrusion 3A on the back surface of the plastic lid 3 into the hole 2A of the base 2 and insert the lower end circumference 3B of the protrusion 3A. Is welded to the back surface of the base 2, and the stripping strip 2B is concentric with the hole 2A.
There is described a medicinal bottle lid which is provided on the mouthpiece 2 outside the hole 2A, and has an annular lip 3D for air circulation blocking, which is press-fitted to the hem portion 2C of the mouthpiece 2 on the inner surface of the hem portion 3C of the lid body 3. .

In the above-mentioned medicated bottle lid, the protruding portion provided on the back surface of the preformed plastic lid body is inserted into the hole of the metal die, and the lower end periphery of the protruding portion is welded to the back surface of the die to make the metal bottle. The cap and the plastic lid are in close contact with each other only at that portion, and an annular lip formed so as to be crimped to the base of the base has a structure for supplementarily blocking air flow.

However, this medicinal bottle lid also has a problem in the sealing property in the case of harsh various treatments, transportations, etc., like the invention described in the above-mentioned JP-A-59-142949, and is reliable as an outer lid for sealing a chemical solution storage container. It lacks sex.

As described above, the outer lid of this type of container is mostly formed of an olefinic resin, and since this resin shows almost no adhesiveness to metal, the conventional composite lid has the center of the plastic outer lid. A protrusion is formed on the lower surface to engage with the opening of the metal inner lid, both are set in the mold, and the protrusion of the plastic outer lid is melted at the same time as the metal by the heated punch. The engagement portion is formed by welding to the periphery of the opening portion of the inner lid, and the both are brought into close contact with each other. Given the technical recognition that the adhesion between olefinic resin and metal is poor, such engagement in the composite lid is rather natural, together with the ease of opening operation during use. it can.

However, in all of the conventionally proposed sealing outer lids, the metal lid and the plastic lid are physically intimately engaged with each other. When an external force is applied, a gap is formed in the engaging portion, which results in the invasion of various bacteria, and the function as the sealing outer cover is lost.

(Problems to be Solved by the Invention) The present invention enhances insufficient sealing reliability in the conventional sealing outer cover, maintains sufficient sealing reliability even in severe processing and transportation, and opens the package. At that time, an attempt is made to obtain a hermetically-sealing outer cover such as a drug solution storage container having a close-adhering structure showing an easily peelable property.

(Means for Solving the Problems) According to the present invention, the top surface of the inner lid and the inner lid made of metal having the top plate portion, the fixing skirt portion around the top plate portion, and the opening portion at the center of the top plate portion. A plastic outer lid having a large-diameter top plate portion that covers the inner lid skirt, a short skirt portion located on the outer periphery of the upper portion of the inner lid skirt portion, and a detachable engaging portion that sealingly engages with the inner lid opening portion, The plastic outer lid is made of an olefin resin having a molding shrinkage of less than 5% (ASTM D 955) and a flexural rigidity of 6000 to 13000 Kg / cm ² (ASTM D 747), and the metal inner lid is a top plate top surface. To the cohesive failure adhesive and the modified olefin resin in a weight ratio of 1: 2 to 1:20 contained a cohesive failure adhesive-containing paint layer, the plastic outer lid is the cohesive failure adhesive-containing paint It is characterized in that it adheres to the inner lid via a layer so as to be peelable in the axial direction of the lid. Genus - plastic composite closure is provided.

According to the present invention, a metal inner lid having a top plate portion, a fixing skirt portion around the top plate portion, and an opening at the center of the top plate portion, and a metal inner lid provided with a cohesive failure adhesive-containing coating layer on the top plate portion upper surface, Molding shrinkage of less than 5%, inserted into a male mold having a cavity surface corresponding to the outer surface of the outer lid top plate portion and the outer lid skirt portion and a female mold having a cavity surface corresponding to the outer lid engaging portion. (ASTM D 955) and flexural rigidity of 6000 to 13000 Kg / cm ² (A
STM D 747) is supplied in a molten state between the metal inner lid and each cavity surface, and the male mold cavity surface has a lower temperature than the female mold cavity surface. There is provided a method for producing a metal-plastic composite lid, which comprises molding a plastic outer lid with.

(Operation) The metal-plastic composite lid according to the present invention comprises: (i) an outer lid having a forming shrinkage of less than 5%, particularly less than 3%;
6000 to 13000 Kg / cm ² , particularly 7000 to 11000 Kg / cm ² flexural rigidity, (ii) the metal inner lid has a cohesive failure adhesive-containing paint layer on at least the top plate upper surface, (iii) ) It is characterized in that the plastic outer lid is peelably adhered to the inner lid in the axial direction of the lid via the coating layer containing the cohesive failure adhesive.

That is, in the composite lid of the present invention, the outer lid and the inner lid are adhered to each other with sufficient reliability to prevent invasion of germs and water and to prevent accidental detachment. When the lid is pushed upward with a finger, the opening can be easily performed with a relatively small opening force.

The molding shrinkage ratio and the bending rigidity ratio of the above (i) are closely related to the openability of the lid. If the molding shrinkage ratio of the outer lid plastic is larger than the above range, the squeezing force acts between the inner lid skirt portion and the outer lid skirt portion, the opening force becomes abnormally large, and the easy-opening property deteriorates. If the flexural rigidity of the outer lid exceeds the above range, the adhesive force between the top surface of the top plate of the inner lid and the inner surface of the outer lid will be simultaneously peeled off, and the opening force will increase abnormally. When the amount is smaller than the above range, the outer lid pushing force is not sufficiently transmitted to the outer lid top plate portion, and in either case, the easy-open property is deteriorated. In the present invention, by forming the molding shrinkage rate of the plastic in the above-mentioned small range, it is possible to reduce the tightening force of the hook and effectively perform the upward shift of the outer lid,
While the push-up force is sufficiently transmitted to the outer lid top plate portion at the time of opening, an appropriate warp is given to the outer lid top plate portion to promote peeling from one end portion, thereby achieving easy opening.

Providing a coating containing a cohesive destructive adhesive on the upper surface of the top plate of the inner lid made of metal prevents invasion of germs and water between the outer lid and the inner lid, and prevents accidental detachment of both. Moreover, it helps to reduce the opening force and improve the easy-open performance. As is clear from the wording, the cohesive failure adhesive is useful for increasing the adhesion (adhesion) between the coating film and the plastic, but the cohesive force of itself is relatively small, and it is easy for itself to peel off. A material that causes cohesive failure.

In the present invention, the inner lid and the outer lid are in close contact with each other via the coating film containing the cohesive failure adhesive, so that the opening force is combined with the easy-opening level in combination with the above configuration (i). , Ie
It can range from 600 to 1500 g, especially from 800 to 1300 g.

(Explanation of Preferred Embodiment) In FIG. 1 showing an example of a cross-sectional view of the composite lid of the present invention,
The composite lid A of the present invention comprises a metal inner lid 1 and a plastic outer lid.
Made of 10. The metal inner lid 1 is formed of a metal plate such as an aluminum thin plate, and has a top plate portion 2, a skirt portion 3 for fixing the vial jaw portion around the top plate portion 2, and an opening 4 at the center of the top plate portion. The outer lid 10 has a large-diameter top plate portion 11 that covers the upper surface of the inner lid top plate portion, a short skirt portion 12 located on the outer periphery of the upper portion of the inner lid skirt portion 3, and an inner lid opening portion 4.
It has a jaw 13 which is tightly attached so as to cover the edge.

On the upper surface of the top plate portion 2 of the inner lid 1, a cohesive failure adhesive-containing coating film 5 is provided, and the plastic outer lid is provided through this coating film 5.
10 is in close contact with the inner lid. The coating film 5 may be provided only on the upper surface of the top plate portion 2, or may be provided on the side surface of the skirt portion 3.

The plastic outer lid 10 is made of a plastic having a molding shrinkage ratio and a bending rigidity ratio in the ranges described above. The outer lid 10 is most preferably supplied by supplying the specific plastic in a molten state so as to cover the upper surface of the inner lid.
At the same time as molding the outer lid, it achieves close contact with the inner lid.

The inner lid opening 4 and the outer lid 10 have the above-described shapes, a part of the inner surface of the outer lid covers the edge of the opening of the inner lid made of metal, and the contact portion between the inner lid opening 4 and the outer lid 10 is the cohesive fracture adhesive-containing paint. It is most common to form a close contact structure by lightly adhering with, but it is also possible to melt-mold the outer lid so as to form the engaging portion 14 on the inner surface of the opening beyond the end edge of the inner lid opening. (Second
Figure).

As the plastic constituting the outer lid, it is preferable to use an olefin resin such as polyethylene, polypropylene, propylene-ethylene copolymer, or propylene-pten 1 copolymer because of the relationship with the cohesive-destructive adhesive-containing coating layer described later. preferable.

The molding shrinkage rate and bending rigidity rate of the plastic constituting the outer lid are related to the type of resin and the compounding amount of the filler. Molding shrinkage varies depending on the type of resin. For example, low density polyethylene is large, polypropylene is lower, and polycarbonate is significantly smaller. Therefore, in the present invention, if the molding shrinkage ratio and the bending rigidity ratio of the resin alone are within the above ranges, it can be used. When the resin contains a filler, the mold shrinkage rate decreases and the flexural rigidity rate increases with an increase in the compounding amount of the filler. Thus, the desired molding shrinkage and flexural rigidity can be obtained by selecting the type of resin or further the blending amount of the filler. The preferred resins in terms of cost and moldability are high density polyethylene and polypropylene.

As the inorganic filler, rutile type or anatase type titanium dioxide, zinc white, inorganic white pigment such as gloss white; barite, precipitated barium sulfate, calcium carbonate,
White extender pigments such as gypsum, precipitated silica, aerosil, talc, calcined or uncalcined clay, barium carbonate, alumina white, synthetic or natural mica, synthetic calcium silicate, magnesium carbonate, barium carbonate; carbon black, magnetite, etc. Black pigments; red pigments such as red iron oxide; yellow pigments such as Siena; and blue pigments such as ultramarine blue and cobalt blue, but the inorganic fillers usable in the present invention are not limited to those exemplified above.

These inorganic fillers have an average particle size of 0.05 to 20 μm so that they can be easily and uniformly dispersed in the resin.
The specific gravity is preferably in the range of 2.0 to 9.0 from the viewpoint of draw formability. Furthermore, in terms of hiding power and barrier properties, the hiding power according to JIS K-5101 is 5
It is more than 0 cm ² / g. Suitable inorganic fillers are talc, calcium carbonate.

The filling amount of the inorganic filler is 3 to 30% by weight based on the resin,
It is particularly desirable that the amount is in the range of 5 to 20% by weight.

As the metal plate forming the inner lid, a soft metal plate formed from pure aluminum or an aluminum alloy, a tin plate,
A surface-treated steel plate such as tin-free steel or nickel-plated plate is used, and its thickness is generally in the range of 0.15 to 0.3 mm, preferably 0.2 to 0.25 mm.

The cohesive failure adhesive is not limited to this, but the following are used.

1. Aliphatic hydrocarbons Synthetic paraffin Petroleum wax Petrolatum 2. Fatty acids, aliphatic alcohols Higher fatty acids Fatty acids obtained from animal or vegetable fats and oils obtained by hydrogenating those fatty acids with 8 to 22 carbon atoms Hydroxystearic acid Linear aliphatic monohydric alcohol C4 or more obtained by reducing animal or vegetable oils or fats or fatty acid esters thereof or decomposing and distilling natural wax Tridecyl alcohol 3. Polyglycol polyethylene glycol Molecular weight 200-9500 Polypropylene glycol Molecular weight 1000 or more Polyoxypropylene-polyoxyethylene-block polymer Molecular weight 1900-9000 4. Amide, amine Higher fatty acid amide Oleyl palmitoamide stearyl erucamide 2 stearomidoethyl stearate Renbisu fatty acid amide NN 'oleoyl stearyl ethylenediamine NN' bis (2-hydroxyethyl) alkyl (C ₁₂ -C ₁₈₎
Amide NN 'bis (hydroxyethyl) Rauroamaido N-alkyl (C ₁₆ -C ₁₈₎ fatty acid diethanol di (hydroxyethyl) oleate reacted with trimethylene diamine distearate diethylenetriamine monoacetate 5. mono-, polyhydric alcohol fatty acid Ester stearate n-butyl hydrogenated rosin methyl ester dibutyl sebacate <n-butyl> dioctyl sebacate <2 ethylhexyl, n-octyl co> glycerin fatty acid ester glycerin lactostearyl pentaerythritol stearate ester pentaerythritol tetrastearate sorbitan fatty acid Ester Polyethylene glycol fatty acid ester Polyethylene glycol monostearate Polyethylene glycol dilaurate Poly Tylene glycol monooleate Polyethylene glycol dioleate Polyethylene glycol Palm fatty acid ester Polyethylene glycol tall oil Fatty acid ester Ethanediol montanic acid ester 1,3 Butanediol montanic acid ester Diethylene glycol stearic acid ester Propylene glycol fatty acid ester 6. Triglyceride, wax Hydrogenation Edible oils 12-Hydroxystearic acid glycerin ester Hydrogenated fish oil Beef tallow Spam aceti wax Montan wax Carnauba wax Beeswax Beeswax Monohydric aliphatic alcohol and saturated aliphatic ester <Example: hydrogenated whale oil Lauryl stearate, stearyl stearate > 7. Alkali metals, alkaline earth metals, zinc and aluminum salts of higher fatty acids (metal soap) 8. Low molecular weight olefins Down resin low molecular weight polyethylene low molecular weight polypropylene oxide polyethylene low molecular weight acid-modified olefin resin 9.Others propylene glycol alginate dialkyl ketones acrylic copolymers (e.g., Monsanto Modaflow etc.).

The coating material containing the cohesive failure adhesive is preferably one having excellent adhesion to metal and excellent corrosion resistance. Such coatings include 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 thermoplastic resin coating, for example, vinyl chloride-vinyl acetate copolymer, vinyl chloride-maleic acid copolymer Examples thereof include polymers, vinyl chloride-maleic acid-vinyl acetate copolymers, acrylic polymers and saturated polyester resins. These resin paints may be used alone or in combination of two or more.

Suitable paints, such as epoxy-phenolic paints,
A paint comprising an epoxy resin component and a curing agent resin component for the same.

The cohesive failure adhesive is preferably used in the range of 0.5 to 15% by weight, particularly 1.0 to 10% by weight, based on the solid content of the coating resin.
The thickness of the coating film is generally 1.0 to 15 μm, especially 1.5 to 15 μm.
It should be in the range of 10 μm. The cohesive failure-causing adhesive compounded in the coating material floats on the coating film evaluation surface during baking or drying of the coating material, and has the function of causing the coating film and the plastic to adhere to each other in a cohesive failure manner.

In the present invention, since the outer lid is made of an olefin resin, it is possible to adjust the degree of adhesion by blending the modified olefin resin in the paint.

The modified olefin resin or resin composition used for this purpose has the formula In the formula, R is a hydrogen atom or an alkyl group having 4 or less carbon atoms.

Polymers or copolymers of olefins such as low density, medium density or high density polyethylene, polypropylene, ethylene-propylene copolymers, polybutene-1,
A polymer obtained by graft-modifying carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid, anhydrides, salts, esters and amides of the above carboxylic acids, using polypentene-1 etc. as a trunk polymer. ,
Alternatively, the modified olefin resin may be blended with an unmodified olefin resin.

Among the modified resins, one having a low molecular weight is a cohesive failure adhesive agent, but even a high molecular weight resin, the cohesive failure adhesive agent and the modified olefin resin are 1: 2 to 1:20, particularly 1: 4 to It can be used in a weight ratio of 1:15.

Next, a method for molding the composite lid of the present invention will be described. The composite lid is described in, for example, JP-A-62-
It can be molded using a compression molding apparatus for synthetic resin known per se as described in Japanese Patent No. 90210.

That is, the composite lid of the present invention can obtain a sufficiently excellent adhesiveness by insert simultaneous molding by compression molding, but is provided with a top plate portion, a fixing skirt portion around the top plate portion, and an opening portion in the center of the top plate portion, The metallic inner lid provided with the coating film is a male die having a cavity surface corresponding to the outer surfaces of the outer lid top plate portion and the outer lid skirt portion, and a female die having a cavity surface corresponding to the outer lid engaging portion. And the modified olefin resin or resin composition in a molten state is supplied between the metallic inner lid and each cavity surface, and the male cavity surface is more than the female cavity surface. By molding the plastic outer lid under low temperature conditions, it is possible to make the molding shrinkage rate of the plastic outer lid portion that is in close contact with the top plate portion of the metal inner lid smaller than other portions, thus, With metal inner lid A plastic outer lid, it is possible to obtain a composite closure in a state in which further contact.

An example of a molding method of the composite lid of the present invention will be described with reference to the drawings.

3 to 5 show an example of a compression molding apparatus used for compression molding the composite lid of the present invention.

The compression molding apparatus shown in the drawing has a female mold generally designated by 15 and
It has a male type shown by 16.

The female mold includes a stationary member 17 which is suitably fixed to a support frame (not shown). A cavity 19 into which the soft metal inner lid 18 is preliminarily inserted is provided in the central portion of the stationary member, and further reaches an upper end surface of the cavity which is arranged at appropriate intervals in the circumferential direction and extends substantially vertically. A plurality of through holes 20 are provided, and upright pins 21 are inserted into the through holes, respectively, and the upper ends of the pins are provided with the cavities 19
After the molding, the movable member 22 pushes up in a substantially vertical direction to act as an ejector pin for removing the molded composite lid from the mold.

The male mold 16 includes a movable outer member 23 and a movable inner member, which are substantially cylindrical in shape.
Includes 24 and. A circular through opening 25 is formed in the center of the outer member 23. The upper portion 26 of the inner member 24 is formed to have a slightly larger diameter than the lower portion 27, and the boundary step portion 28 thereof is stopped and formed by the boundary step portion 29 on the inner surface of the outer member when the inner member 24 descends and is compression molded. Specify the thickness of the product.
The lower portion 30 of the outer peripheral surface of the outer member 23 is formed in a shape that is tapered slightly downward, and the peripheral surface of the concave portion of the stationary member 17 in the female die 15 is formed.
It corresponds to 31. The lower inner peripheral surface 32 surrounds the side wall surface of the metal inner lid 18 inserted into the cavity 19 with an interval corresponding to the wall thickness of the plastic outer wall, and the lower end thereof defines the length of the skirt portion of the plastic outer lid. To do.

The lower end surface (male cavity) 34 of the inner member 24 is engraved with a pattern 35 such as an annular concave portion (or convex portion) according to the shape of the plastic outer lid.

Before starting the compression formation, the female mold 15 and the male mold 16 are
It is positioned as shown in the figure. At this time, male
It is necessary to set the temperature of the cavity surface 34 of 16 lower than the temperature of the cavity surface 19 of the female mold 15, and by molding by making the temperature of the mold different in this way, it is possible to Since the shrinkage rate is smaller than the shrinkage rate in other parts, a composite lid excellent in dimensional stability and adhesion can be obtained.

An inner lid formed of a soft metal such as aluminum is inserted into the cavity 19 surface of the female die 15, and a required amount of the synthetic resin material 36 for forming the outer lid is supplied in a molten state onto the inner lid. Next, the female mold 15 and the male mold 16 are subjected to a front mold closing step as shown in FIG. That is, the outer member 23 of the male die 16 is lowered to the lower limit position shown in FIG. At the lower limit position, the outer peripheral surface lower portion 30 of the outer member 23 is fixed to the stationary member 17.
The outer member 23 stops by contacting the peripheral surface of the recess 31. By performing this front mold closing step, the outer member 23 of the male mold 16 is
A space defining the skirt portion of the plastic outer lid is formed by the lower inner surface 32 of the outer peripheral surface and the lower end 33 of the recess 31 of the stationary member 17 in the female die 15.

In the mold closing step, the inner member 24 of the male mold 16 is also lowered, but it is important that the inner member 24 is not lowered to a position where a substantial compressive action is exerted on the molten synthetic resin material 36. .

Then, a compression process is performed. That is, as shown in FIG. 5, the inner member 24 of the male die 16 is lowered by a required compression force, and the synthetic resin material 36 is compression-molded. Thus, the top space wall 37 and the skirt portion 38 of the plastic outer lid of the composite lid are attached to the metal inner lid 18 by the die space portion defined between the stationary member 17 of the female die and the inner member 24 of the male die 16. They are formed in close contact, and thus the composite lid shown in FIG. 1 is obtained. The obtained composite lid has a movable member 22 provided by the stationary member 17 of the female mold 15 after the mold is opened.
By operating, the pin is pushed up in the vertical direction and removed from the mold.

(Example) Example 1 Add 3.0 PHR of maleic acid-modified polypropylene as a cohesive failure adhesive and 0.2 PHR (maleic acid-modified polypropylene / modaflow = 15/1) of diacryl ketone-acrylic copolymer (Modaflow manufactured by Monsanto). A 0.23 mm thick aluminum plate coated with the epoxy phenol paint was punched out to form an inner lid with a diameter of 20 mm and a hole diameter of 8 mm.

Next, using the apparatus shown in FIG. 3, a composite lid including a polypropylene resin containing 20% talc, a bending rigidity rate of 11000 Kg / cm ² , and a molding shrinkage rate of 1.2% and the inner lid was prepared. The molding conditions are as follows.

Female mold temperature 80 ° C Male mold temperature 20 ° C Molding cycle 3 seconds After the composite lid thus obtained was sterilized by retort, the sealability between the inner lid and the outer lid was evaluated with a penetrant, and no liquid penetrated. The hermeticity was perfect.

Next, when the peeling force between the inner lid and the outer lid was measured to evaluate the opening property of the composite lid, it showed a value of 1.0 to 1.2 Kg and had a good easy opening property.

Comparative Example 1 With respect to the composite lid described in Japanese Utility Model Laid-Open No. 54-128859, the same penetrant test as in Example 1 was carried out. As a result, penetration of the liquid was observed at the boundary surface between the inner lid and the outer lid, and the sealing performance was improved. Was insufficient.

Comparative Example 2 The paint used in Example 1 was changed to maleic acid-modified polypropylene.
A composite lid prepared in exactly the same manner as in Example 1 except that it was changed to an epoxyphenol paint containing only 8.0 PHR (7.4% by weight) was subjected to an opening test and showed an opening force of 4.5 Kg, which was far beyond the range of easy opening. Was over.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a preferred example of the composite lid of the present invention, and FIG. 2 is a vertical sectional view showing another preferred example of the composite lid of the present invention. FIG. 3 is a diagram showing a main part of a compression molding apparatus for carrying out the compression molding method for a composite lid of the present invention and its operating procedure. 1 …… Inner lid made of soft metal 2 …… Inner lid top plate 3 …… Inner lid skirt 4 …… Inner lid central opening 5 …… Coating-breaking adhesive-containing coating 10 …… Plastic outer lid 11 …… Plastic outer lid top plate 12 …… Outer lid skirt 13 …… Jaw of outer lid that covers inner lid opening edge 14 …… Engagement of inner and outer lid 15 …… Female 16 …… Male 17 …… Female stationary member 18 …… Soft metal inner lid 19 …… Female cavity 20 …… Through hole 21 …… Upright pin 22 …… Female movable member 23 …… Male movable outer member 24… … Male movable inner member 25 …… Circular through hole 28 …… Step of inner member diameter 29 …… Step of outer member diameter 30 …… Lower male outer peripheral surface 31 …… Recessed peripheral surface 32 …… Male lower inner peripheral surface 33 …… Female mold lower end 34 …… Male mold cavity 35 …… Inscription of male cavity surface 36 …… Synthetic resin material supplied in molten state 37 …… … The top wall of the outer lid 38 …… Outer skirt

Claims (2)

[Claims] 1. A metal inner lid having a top plate portion, a fixing skirt portion around the top plate portion, and an opening at the center of the top plate portion, and a large-diameter top plate portion covering the upper surface of the inner lid top plate portion, and an inner lid. It comprises a plastic outer lid made of an olefin resin having a short skirt located on the outer periphery of the upper part of the skirt and a detachable engaging portion for sealingly engaging the inner lid opening, the plastic outer lid being 5%. Mold shrinkage of less than (ASTM D 9
55) and a flexural rigidity of 6000 to 13000 Kg / cm ² (ASTM D 74
7) and an olefinic resin having a cohesive failure adhesive agent containing a cohesive failure adhesive agent and a modified olefin resin in a weight ratio of 1: 2 to 1:20 on the upper surface of the top plate. A metal-plastic composite lid characterized in that it has a coating material layer containing the coating material, and the plastic outer lid is releasably adhered to the inner lid in the axial direction of the lid via the coating layer containing the cohesive failure adhesive. . 2. An outer lid made of a metal, comprising a top plate portion, a fixing skirt portion around the top plate portion, an opening portion at the center of the top plate portion, and a coating layer containing a cohesive destructive adhesive agent provided on the upper surface of the top plate portion. It is inserted into a male mold having a cavity surface corresponding to the outer surface of the top plate portion and the outer lid skirt and a female mold having a cavity surface corresponding to the outer lid engaging portion, and the molding shrinkage ratio (ASTM D
955) and flexural rigidity of 6000 to 13000 Kg / cm ² (ASTM D 74
7) is supplied in a molten state between the metal inner lid and each cavity surface, and the plastic is produced under the temperature condition that the cavity surface of the male mold has a lower temperature than the cavity surface of the female mold. A method for producing a metal-plastic composite lid, which comprises molding an outer lid.