JPS61152550A - Plastic can with metallic cover - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application IF) The present invention relates to a metal-clad plastic can,
More specifically, the present invention provides a plastic can in which the opening of one can body is double-sealed with an extension of Sumitomo Metal A't-, and the double-sealed portion has high strength.

(Prior Art) Aluminum cans have excellent properties such as airtightness and strength, and are therefore widely used for various containers, especially beverage containers, but the material used is expensive.

There are some disadvantages, such as the container being opaque and the contents not being visible from the outside. In order to solve this problem, the following method has been proposed in which a ductile metal lid made of aluminum or the like is attached to the plastic opening. Fit the metal lid to the plastic opening of the aluminum can.

The double winding method, which is conventionally used for steel cans, is applied.

(Problem to be Solved by the Invention) In conventional double seaming of metal cans, synthetic rubber or filler is used between the can body and the can lid in the roll # part in order to prevent the contents from leaking from the first roll part. Sealants containing resins, adhesives, etc., i.e.
Sealing compound is interposed. 5/, +
Ring Conbound Ha Tsu'7g The inside circumference of the bottom of the lid is painted. The extendable metal lid used on metal cans is also applied to plastic cans. When a plastic can made of a cylindrical plastic can body with an opening at one or both ends double-sealed with ductile metal is used, the internal pressure is constant, such as when filled with carbonated drinks. In such cases, the container body often separates from the metal lid due to the internal pressure.

The present invention aims to solve the above-mentioned problems by providing a plastic can with a metal lid in which the container body and the lid do not separate from each other and the sealing performance does not deteriorate.

(Means for Solving the Problems) The present invention provides a plastic can formed by double-sealing a malleable metal around the opening of a cylindrical plastic can body having an opening at one or both ends. The sealing compound used for the double seam part for sealing is 10I.
The present invention relates to a plastic with a metal lid, which is characterized by having an IF or less. The above-mentioned plastic can according to the present invention provides a plastic can with a metal lid in which the lid does not come off from the container body and the sealing performance does not deteriorate.

To explain the invention with the aid of drawings, FIG. 2 shows a cross-sectional view of a metal lid 1, with a V-ring compound 2 applied to the inner circumference of the metal lid 1.

Figure 3 is a cross-sectional view showing the process of seaming. Figure 3a is a partial cross-sectional view of the can lid before seaming placed on the flange surface of the can body. FIG. 3 is a partial cross-sectional view showing the folded surface after being deformed by a fast roller. In the figure, 3 is the can body, and as shown in Figure 3b, when the first seam tightening is started, a compressive force is applied to the sealing compound 2 at the tip of the can body, as indicated by the arrow.
My strength is weak.

FIG. 4 shows a sectional view of the seaming part of a conventional metal can.

The sealing compound 2 applied to the inner circumferential part of the metal lid 1 is sheared and deformed by the tip of the can body 3 and enters between the lid bodies, and only a portion of the sealing compound 2 is applied to the lower clearance part 5.
．． It remains in the under clearance section 6. In this case, a sufficient length of the body hook portion 4 is ensured. FIG. 5 is a sectional view of the seamed portion of a plastic can when a large amount of sealing compound is applied as in conventional metal cans and a metal lid is used. Sea I applied to the shoulder of the metal lid 10 yen
J7 The sealing compound 2 is not sheared and deformed to the tip of the can body 3, but on the contrary, the tip of the can body 3 retreats or deforms due to the compressive force, so a large amount of sealing compound is applied to the lower clearance part 5. 6 and 9 exist. The length of the body hook portion 4 cannot be ensured sufficiently. FIG. 1 is a cross-sectional view of the seam of a plastic can using a metal lid to which no sealing compound has been applied.

Metal Wt I K v -! Since J-Song compound is not applied, the tip of the can body 3 sufficiently enters the lower clearance, and the length of the body hook 4 is ensured sufficiently.

In this way, the sealing compound is an obstacle to securing the body hook length. As shown in Figure 21 and Figure 3a, ways to prevent this are to change the application method by changing the current normal application method of applying the sealing compound thickly to the tip of the circumference to a uniform application, and to remove the applied sealant. Another possible method is to improve the lubricity of the compound surface and reduce the compressive force applied to the tip of the can body.

The simplest and most effective method is to remove the ceiling and
The method is to reduce the amount of compound, and preferably double seams under unused seaming conditions.

Originally, the S'-+3 ring compound plays a role in preventing leakage caused by insufficient adhesion due to metal-to-metal contact in metal cans. On the other hand, for plastic cans, even the material with the highest elastic modulus is about one-third that of aluminum, and can be sufficiently compressed and deformed by the compressive force of the second roll to make a tight contact with the metal lid. . Therefore, for plastic cans, the amount of V-ring bound is significantly reduced compared to metal cans, and the sealing performance of the seaming part is improved without using conventional metal cans or a large amount of sealing compound. It is not inferior to the double-sealed part of the next Pufstick can. The materials of this plastic can are polyethylene, polypropylene, polyester,
Examples include thermoplastic resins such as high-impact polystyrene and polycarbonate, but particularly preferred is a thermoplastic polyester having ethylene terephthalate as its main repeating unit. This will be explained in detail below.

Thermoplastic polyester usually has an acid component of 80 mo/I/s.
In the above, preferably 90% or more is terephthalic acid, and 80'1 = lWfb% of the glycol component, preferably 9
07 Polyesters in which one or more of the molecules are ethylene glycol
SI, and the remaining other acid components are isophthalic acid,
Diphenyl ether 4*4'-dicarboxylic acid, naphthalene 1,4-1, 2,6-dicaponic acid, adipic acid, sebacic acid, decane 1,10-dicarboxylic acid, hexahydroterephthalic acid, etc. Glycol components include propylene glycol, 1.4-butanedio-〃, neopentyl glycol 1v, di1fV glycol-1v, 1.6
-hexane glycol, cyclohexane dimetatool, 2,2-bis(4-hydroxyphenyl)furopane.

2.2-bis(4-hydroxyVethoxyVpheni/I/)
propane, then p-oxybenzoic acid as oxy-V acid,
Polyester containing p-hydroethoxybenzoic acid, etc./
L/l - means. Also, within the range that does not impair moldability,
A polyfunctional component having higher functionality may be copolymerized. It may also be a mixture of two or more types of polyester, such as a mixture of polyethylene terephthalate and another thermoplastic polyester, in which the amount of ethylene terephthalate is 807 to 1 or more.

In addition, the polyester in this invention may contain a colorant, an ultraviolet absorber, an antistatic agent, a thermal oxidative deterioration inhibitor,
Additives such as antibacterial agents, lubricants, inorganic fillers, etc. can be included in advance as appropriate.

The thermoplastic polyester of the present invention must have an intrinsic viscosity of 0.55 or more, preferably 0.6 or more, and more preferably 0.7 to 1.4.

What is the intrinsic viscosity of pheno-N/tetocloethane mixed solution K?
(6/4 weight ratio) polyester A/l-dissolved solution t
This is the intrinsic viscosity measured at -30°C. The present invention also provides a laminated cylinder or coated polyester with a resin having excellent gas barrier properties such as polyester and other resin such as polyamide containing a metakylylene product, polyvinylidene chloride, or acrylonitrile-styrene copolymer. It also includes a can body made of a cylinder.

To produce a cylindrical polyester can, it is melt-extruded and molded through a die of a predetermined shape in a thermoplastic polyester extrusion molding machine. When it is desired to impart transparency to a can, the melt-extruded pipe is rapidly cooled to below room temperature with a ninth sipe that regulates the shape of the pipe to form an amorphous pipe. Also, when trying to increase the mechanical strength of the can body.

The extruded pipe is heated to a temperature suitable for stretching, above the glass transition point and below 150° C., and uniaxially or biaxially stretched.

Furthermore, if the can body is to withstand high temperatures such as filling with high-temperature liquid or high-temperature sterilization, the stretched pipe is heat-set under tension.

As mentioned above, the plastic can according to the second aspect of the present invention can have any desired performance by changing the processing conditions after melt extrusion. In addition, bottomed containers and injection molding are obtained by deep drawing unstretched or low-stretched sheets by vacuum forming, pressure forming, etc.

The bottomed preform obtained by extrusion molding can also be applied to the seaming of a bottomed container of the blow bottle type formed by so-called stretch blow molding.

The material of the metal lid is ductile, and includes aluminum, tinplate, metal laminated or coated with plastic, and the like.

The V-ring compound has rubber properties such as butadiene rubber and neoprene rubber.

It is a synthetic rubber such as vinyl chloride mixed with appropriate fillers, resins, and thickeners.

The plastic can of the present invention can be used not only as a food can for carbonated drinks and beer, but also for non-food cans such as tennis balls, in which internal pressure is constantly maintained, and in a wide range of other fields. .

This invention will be explained in detail below.

Example: Polyvinyl terephthalate having an intrinsic viscosity of 0.75 (measured at 30°C using a 6/4 weight ratio mixed solution of phenol/tetrachloroethane) was melted at -275°C and extruded through a pipe die to obtain the inner diameter. 15.8 garden, outer diameter 17.711
It was extruded into a tube shape of 11, and then blow-stretched at 95°C with pressurized air of 10A at 2 cylinders, and stretched 3 times in the circumferential direction to have an inner diameter of 52.4ar.
, a stretched tube with an outer diameter of 53.0M was formed. This stretched tube was cut into a length of 1,401 EIl, and then the openings at both ends were thermoformed for 7 runs at 100° C. using a hand press machine. Next, V-ring compound 65q was applied to one of the flange surfaces formed at both end openings to a thickness of Q, 35.
m aluminum lid (Nominal size 202F manufactured by Shinryo Seika Co., Ltd.)
41 type) V-ring compound was removed with acetone to remove 1111 N of the sealing compound-free Q aluminum lid, which was then rolled and tightened with Semitronmer (manufactured by Handa Ichiki Co., Ltd.). Next, add 250 g of condensed carbonated water of 4.0 gas volume, which is a mixed solution of sodium carbonate and dilute sulfuric acid.
The container was filled at tt-2° C., and an aluminum lid obtained by the above method without sealing compound was sealed on the other open flange surface in the same manner as above. In addition, as a comparative example, in the above example, hV-! J-Song Compound T-Non Swell 65" 1% V-Ring Compound Coated Aluminum Lid
When the cans were left in a warm air chamber at 0° C. for 24 hours, no breakage of the seamed portion was observed in the examples, but in 8 out of 10 cans of the comparative example, the aluminum lids came off from the seamed portions within 24 hours. Furthermore, when the weights of the 10 cans of Example were measured before and after being left at 50°C, no difference was observed.

[Brief explanation of drawings]

Figure 2 is a sectional view of the metal lid coated with V-ring compound, and Figure 3 is a sectional view showing the seaming process.
1 is a partial view of the seaming part before seaming, and b is a partial view of the seaming part after being deformed by the first roller of the seaming machine. Fig. 4 is a partial sectional view of the seaming part of a conventional metal can, Fig. 5 is a partial sectional view of the seaming part of a plastic can using the same glue ring compound as the conventional metal can, and Fig. 1 is a partial sectional view of the seaming part of a conventional metal can. FIG. 2 is a partial partial view of the seaming part of a plastic can that does not use a compound. 1... Metal lid 2... V-ring fist compound 3... Can body 4... Body hook 5... Lower clearance 6... Upper clearance

Claims (2)

[Claims] (1) In a plastic can made by double-sealing a malleable metal around the opening of a cylindrical plastic can body with an opening at one or both ends, double-sealing is performed to ensure the sealing of the double-sealed part. A plastic can with a metal lid, characterized in that the amount of sealing compound used in the can is 10 mg or less. (2) The plastic can according to claim 1, wherein the plastic is a thermoplastic polyester mainly containing ethylene terephthalate repeating units.