JPS60243183A - Method of preventing liquid leak of can - Google Patents

Abstract

PURPOSE:To prevent liquid leakage, and to produce large source saving effect on can manufacturing industry, by injecting alpha-cyanoacrylate into a liquid leakage part occurring a weld part or bonded part of a metallic can. CONSTITUTION:alpha-Cyanoacrylate is injected and permeated into a void part existing in a weld part and bonded part of a can that is in a liquid leakage, it is polymerized and solidified in the void part so that liquid leakage is prevented. The alpha-cyanoacrylate has preferably <=500cp viscosity, and when rapid solidification is required, preferably a curing promotor is used with it.

Description

Detailed Description of the Invention (1) Purpose of the invention "Field of industrial application" The present invention relates to a method for preventing liquid leakage from metal cans, and is most commonly used in the can manufacturing industry. However, it is not only widely used in industries that use cans as containers, but also available in households.

"Prior Art" Conventionally, metal cans have been manufactured by using tin-containing steel plates for cans, such as tinplate, and joining them with solder. If a can that has been joined with solder leaks due to a poor joint, you can easily remove the liquid by heating the part again to above the melting point of the solder and rejoining, or by applying a thick layer of solder. We were able to stop the leak.

However, in recent years, due to the soaring price of tin, steel plates for cans that do not use tin, so-called tin-free steel (TFS), have been developed, and methods for manufacturing cans using TFS steel plates have been widely used.

The following method is adopted as a joining method in a method for manufacturing cans using TFS steel plates and the like.

In other words, the can bodies are joined using nylon tape, olefin emulsion type adhesives, or welding, and the double seams at the top and bottom are joined using rubber sealants, olefin emulsion type adhesives, or welding. It is bonded using a urethane emulsion type adhesive.

With these joining methods that do not use solder, it is extremely difficult to repair leaks that occur in joints that can easily be made with solder, and in reality, the only option is to discard cans with leaks. Currently, there is no means to do so, and even cans that are similar to finished Habo products are being discarded.

Furthermore, if a liquid leakage is found while the contents are still in the can, it is necessary to transfer the contents to another container and dispose of the leaking can.

"Problem to be Solved by the Invention" The current manufacturing process has the problem that if a can manufactured by adhesion or welding using TFS steel plates etc. has a leaking part, the can must be discarded. Especially for large cans such as 18L cans, the cost per can is high, and not only is it a big loss just to dispose of it, but it also requires a large space to dispose of it, which is a big problem. The inventors have made repeated studies to solve these problems and have completed the present invention.

(2) Structure of the Invention ``Means for Solving the Problems'' The present invention involves injecting α-cyanoacrylate into the welded or bonded part of a metal can. This invention relates to a method for preventing liquid leakage of cans, which is characterized by preventing liquid leakage.

Anoacrylate is injected and penetrated, and α-cyanoacrylate is polymerized and solidified in the voids, thereby eliminating voids and preventing liquid leakage.

The α-cyanoacrylate used in the present invention is widely used as the main component of commercially available α-cyanoacrylate-based instant adhesives, and in the present invention, these α-cyanoacrylate-based adhesives are It is possible to use the agent as it is as α-cyanoacrylate, and this is a preferred method because it is easily available.

In the method of the present invention, α-cyanoacrylate is injected into the voids formed in the welded or bonded parts and solidified to prevent liquid leakage. Preferably, the lower the viscosity, the greater the leakage prevention effect. On the other hand, if the viscosity is high, the permeability will be poor and the leakage prevention effect will be reduced, so it is preferable to select and use α-cyanoacrylate with a viscosity of 500 cp or less.

As this α-cyanoacrylate, commercially available adhesives such as Aron Alpha 101 (viscosity 2 cp) and 102 (viscosity 10 cp) manufactured by Toagosei Chemical Industry Co., Ltd.
0 cp), 201 (2 cp), etc. can be used as is.

In the method of the present invention, it is possible to prevent liquid leakage even when the contents are inside the can.In order to prevent liquid leakage while the contents remain inside the can, injection penetration Since it is necessary to quickly solidify the α-cyanoacrylate, it is preferable to use a known curing accelerator for α-cyanoacrylate adhesives.

As curing accelerators, amines, quaternary ammonium salts,
Solutions of phosphonium salts are preferred; amine accelerators include diethylamine, 〇-phenylenediamine, dimethyl para-toluidine, ethyl buttluidine, N-N
Alcohol solutions such as diethylaniline, trichloroacetamide, succinimide, etc. are used as phosphonium salts, and promoters include alcohol solutions such as tetramethylphosphonium cupride, tetra-n-butylphosphonium chloride, etc. Examples of quaternary ammonium salt accelerators include alkyl ammonium salts, amide-bonded ammonium salts, ester-bonded ammonium salts, ether-bonded ammonium salts, as shown in Japanese Patent Publication No. 52-11685.
and alcohol base solutions such as alkylimidazolium salts.

A commercially available curing accelerator is available under the trade name a-asetter manufactured by Toagosei Kagaku Kogyo Co., Ltd., which can be used in the present invention.

If a curing accelerator is used in combination, α-cyanoacrylate will solidify quickly, so in order to avoid solidifying too quickly and before the injection and penetration into the voids is completed, use a curing accelerator in combination. When using α-cyanoacrylate with a viscosity of 50 cp or less, the injection penetration method is to apply α-cyanoacrylate to the leaking area using a general method, which requires particularly complicated equipment. , does not require any steps.

In addition, when a curing accelerator is used in combination, it may be applied prior to the application of α-cyanoacrylate.

``Action'' α-cyanoacrylate is used in tinplate and T-shirts, which are the materials for cans.
Because it has good adhesion with FS or paints such as epoxy, epoxy/phenol, vinyl, and melamine paints applied to these surfaces, α-cyanoacrylate that has penetrated into the voids is free from these substances. It adheres well and solidifies, eliminating voids that can cause liquid leaks.

It is presumed that liquid leakage can be prevented.

"Example" 1. Creation of cans Using a normal welded can body can making machine, can bodies for 18/cans were made by 0, '3.
It was made from a 2m thick tin plate. On the other hand, the top and bottom end plates were formed using a tin plate using the usual method, coated with a double-wound product (product name manufactured by Nippon Kogyo), and dried in a drying oven at 80°C until the adhesive was 0.3g/
The top and bottom end plates were made by coating the top and bottom sheets.

This can body was taken out by 72 inches, and the top and bottom end plates were double-sealed, and the top and bottom joints were heated by high-frequency induction to 200°C and bonded. At this time, the winding thickness of the double seaming part is set to the usual 2.6 to 3.
The can was rolled up loosely so that the thickness was 3.0 to 5.2 thicker than Off, and a can that was prone to liquid leakage was created.

From inside the can made in this way, the internal pressure was 0.1 kf/
Submerged leak test under CRD pressure, leaking cans
I selected 0 cans.

Similarly, for both the can body and top and bottom end plates, the inner surface is coated with epoxy phenol, and the outer surface is coated with epoxy.1- A can is made in the same manner as a tin plate, and a leak test is performed to prevent leaking cans. I selected 100 cans.

2. Prevention of liquid leakage When kerosene was poured into each of the 50 leaky cans prepared in Section 1, the kerosene leaked out.

Aron Alfana 201 (viscosity 2 cp) was injected into 25 empty tin and TFS cans from the outside of the double-sealed part.
After 2 hours, an underwater leak test was conducted with an internal pressure of 0.2 kf/Cd.
(viscosity: 1500 cp) was injected into the double-sealed parts of 25 tinplate and 'I' FS cans each, and a leak test was conducted after 2 hours.

Furthermore, after thoroughly wiping out the leaked kerosene from 50 tinplates and TFS cans each filled with kerosene, the ground end was left facing up and left for a day and night. Apply hardening accelerator A-A 5etter (trade name) manufactured by Kogyo ■ thoroughly, leave it for 1 hour, then apply Aron Alfana 201 (viscosity 2 cp) to each of 25 cans and Aron Alfana 202 (viscosity 2 cp) to each of the remaining 25 cans. f100ψcp) was applied to the double-sealed part and left for one day and night.Then, the base plate was turned over and left for one week, after which the presence or absence of kerosene was visually judged.The above results are shown in Table 1. .

Table 1 (3) Effects of the Invention As was made clear in the above examples, the method of the present invention can easily and reliably prevent liquid leakage from cans caused by leaking TFS steel plates, etc., which conventionally had to be discarded. Since the cans can be used without being disposed of, this can bring about a large capital saving effect in the can manufacturing industry.

Furthermore, since it is possible to prevent liquid leakage without transferring the contents, the present invention can be used not only in the can manufacturing industry, but also in general industry and even in households. Do not throw away the resulting can (,
The present invention is very effective because it enables continued use or reuse.

Name of patent applicant Toagosei Kagaku Kogyo Co., Ltd. Procedural amendment June 80, 1980 Kazuto Wakasugi, Commissioner of the Patent Office 1, Indication of the case 1981 Patent Application No. 97504 2, Name of the invention Liquid leaking from a can Prevention method 3, relationship with the case of the person making the amendment Patent applicant address: 1-14 Nishi-Shinbashi, Minato-ku, Tokyo @ No. 4, Detailed description of the invention in the specification subject to amendment 5, Contents of 7iltiE (1) ) In the third line from the bottom of page 8 of the specification, it says "3.0-3.2 thicker than 2.6-3.0 dragon", rl, 6-2.0 night-thicker than 2.0-2 Correct it to .2 ml J.

(2) On page 10, line 8 of the specification, the phrase "kerosene leak" is corrected to rkerosene leak J.

that's all

Claims (1)

[Claims] A method for preventing liquid leakage in a can, characterized by preventing leakage.