JPH0891428A - Packaging material and container for bond flux - Google Patents

Abstract

PURPOSE: To obtain a container that can sufficiently keep a moisture absorption resistance even in the packaging of a bond flux, can be prevented from being powdered even in a mass transport, and can be easily processed after use. CONSTITUTION: A packaging material for a bond flux is a packaging material provided with an interior material and an exterior material. The interior material has a three-layer structure of an inner layer, an intermediate layer, and an outer layer in close contact with each other. The inner layer and the outer layer are each made of a polymer film of 20μm or more thickness so as to be 60-200μm in total thickness. The intermediate layer is made of an aluminum foil of 5-20μm thickness. The exterior material is made of a material having a flexibility.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bond flux packaging material having strength, moisture absorption resistance and impact resistance in transportation of a large amount of bond flux for submerged arc welding of 20 to 1000 kg.

[0002]

2. Description of the Related Art Bond flux is a type of flux for submerged arc welding, and is a powdery raw material such as rutile (TiO ₂ ), magnesia (MgO), silica sand (SiO ₂ ), fluorite (CaF ₂ ) or Lime (CaCO ₃ )
Etc. are mixed, a fixing agent (water glass or the like) is added, and the mixture is kneaded and granulated, and then dried at a temperature of 400 to 600.degree. Since this type of flux has a relatively low firing temperature compared to molten flux, it can be added with alloy components, iron powder, etc., and is generally resistant to high current or high heat input welding, and is widely used in shipbuilding or steel fields. There is.

However, since the bond flux is produced by fixing the powdery raw material with water glass, it has a property that it easily absorbs moisture and is easily pulverized, that is, finely pulverized into powder. FIG. 1 is a diagram showing a moisture absorption curve of a flux at a temperature of 30 ° C. and a humidity of 80%, in which the horizontal axis represents the moisture absorption time and the vertical axis represents the moisture absorption amount. As shown in FIG. 1, bond flux is different from molten flux
Moisture absorption increases with time. Therefore, when transporting the bond flux conventionally, it was necessary to package it in a can and to handle it carefully so as not to give an impact to avoid moisture absorption.

[0004]

Generally, when the flux absorbs moisture, the weld metal may be cracked, and pore defects such as pits or blow holes may occur, resulting in a significant loss of reliability of the welded joint. It has been known. Further, if the flux is pulverized, the gas escape during welding is impaired, the amount of blow-up becomes large, the workability deteriorates, and the bead appearance becomes rough.

Due to such a property of the bond flux, an 18-liter can, a so-called Ito can, which is provided with a lid having excellent sealing property, is generally used in supply or transportation. However, in the case of supplying or transporting with such a can, a builder who particularly uses a large amount of flux needs to increase the size of the can to reduce the frequency of handling the can and improve work efficiency. There is also a demand for easily treating the cans that are produced in large quantities after using the flux.

In order to deal with such a problem, for example, a flexible container having a polyethylene film bag inside has been studied. However, since a polymer film such as a polyethylene film has moisture permeability, the flux absorbs moisture and the Such welding defects will occur.

The present invention has been made in view of the above problems, and it is possible to sufficiently maintain the moisture absorption resistance even when the bond flux is packaged, and to prevent pulverization even when transported in large quantities. It is an object of the present invention to provide a packaging material for bond flux, which is capable of easily treating the used container.

[0008]

The bond flux packaging material according to the present invention is a packaging material having an interior and an exterior, wherein the interior has a three-layer structure in which an inner layer, an intermediate layer and an outer layer are in close contact with each other. Each outer layer has a thickness of 20 μm
As described above, the polymer film has a total thickness of 60 to 200 μm, and the intermediate layer has a thickness of 5 to 20 μm.
m aluminum foil, and the exterior is formed of a flexible material.

[0009]

The present inventors first investigated various materials in order to improve the moisture permeability of the packaging material. As a result, they have found that the use of a material composed of an aluminum foil and a polymer film improves the moisture permeability and can secure the moisture absorption resistance even when the bond flux is packaged.

However, since the bond flux is a granular substance made of a mineral raw material such as various oxides, fluorides or carbonates, it is hard and easily scratches the aluminum foil or the polymer film, and simply the aluminum foil and the polymer film. With the packaging material in which the above was adhered, a satisfactory container for bond flux could not be obtained.

Then, the inventors of the present application have found that the object of the present invention can be achieved by adjusting the thickness of the aluminum foil and the polymer film.

The present invention is a packaging material for bond flux, which has its own interior and exterior features. In particular, the interior is made of aluminum in order to protect the aluminum foil, which is very easily scratched, while considering the hygroscopicity of bond flux. It has a three-layer structure in which foil is sandwiched between polymer films.

The inner and outer polymer films sandwiching the aluminum foil must have a thickness of at least 20 μm or more to protect the aluminum foil.

In FIG. 2, the horizontal axis represents the thickness of the polymer film, and the vertical axis represents the water vapor transmission rate, that is, 1 m of film per 24 hours.
FIG. 6 is a graph showing the relationship between the water vapor transmission rate and the film thickness of a polymer film at a temperature of 30 ° C. and a humidity of 90% by taking the amount of water permeation in ² . As shown in FIG. 2, when the thickness of the polymer film is less than 60 μm, that is, until the thickness of the polymer film becomes 60 μm, the water vapor permeability rapidly decreases as the polymer film becomes thicker, and even at 60 μm or more. The water vapor transmission rate decreases, but the decrease is gradual. Therefore, the total thickness of the inner and outer polymer films is at least 60 μm or more in order to keep the moisture permeability low even when the aluminum foil is scratched or has holes.

If the polymer film is too thick, it may be inconvenient to handle. Therefore, considering the ease of handling, the total thickness of the inner and outer polymer films is set to 200 μm or less.

The aluminum foil sandwiched between the polymer films, which is the intermediate layer in the interior, does not have moisture permeability, but if the thickness is too thin, it will easily be punctured or scratched during handling. A thickness of 5 μm or more is required.

The thicker the aluminum foil is, the stronger it is. However, the thicker the aluminum foil, the lower the flexibility of the packaging material. Therefore, the thickness of the aluminum foil is 20μ
m or less.

As for the exterior, since the moisture absorption resistance is ensured in the interior, the flux has a buffering effect against a shock during transportation, so that the flux can be prevented from being pulverized, and the present invention can be applied. It is necessary that the bond flux container can be folded and carried when the inside is empty. Therefore, if the material of the outer package is, for example, cardboard-shaped paper, rubber, cloth, or polymer fiber, it is possible to buffer the shock during transportation and meet the above requirements.

When a container is manufactured from the packaging material according to the present invention, for example, if the container is a bag, a method of closing the bag may be to tie the mouth with a rubber band or a string, but the sealing property is A method of fusing a polymer film for the interior is preferable in order to increase the height.

[0020]

EXAMPLES Examples of the present invention will be described below in comparison with comparative examples that depart from the claims of the present invention.

In Examples 1 to 6 shown in Table 1 below, the thickness of the polymer film inside and outside the interior and the thickness of the aluminum foil are within the claims of the present invention, and the exterior is high. Using molecular fiber, cloth, cardboard paper or rubber, create a bag or box-shaped container for bond flux,
Flux was enclosed in the container and the state of bond flux after transportation and the handling property in transportation were evaluated.

[0022]

[Table 1]

In Examples 1 to 6, the bond flux state after transportation and the handling property during transportation show good results.

On the other hand, in Comparative Examples 7 and 8, the inner aluminum foil and the inner layer polymer film were thin,
Bond flux absorbs moisture. Further, in Comparative Example 9, the total thickness of the polymer films of the inner layer and the outer layer of the interior is 3
Since it is as thick as 00 μm, the handleability is extremely poor. Further, in Comparative Example 10, the limitation of the interior is within the scope of the claims of the present invention, but since the exterior is a metal can, most of the impact on the can propagates to the bond flux and is pulverized. Therefore, the comprehensive evaluation of Comparative Examples 7 to 10 is inferior to that of the example.

[0025]

As described above, according to the present invention,
The moisture absorption resistance can be sufficiently maintained even if the bond flux is packaged. Further, even if a large amount of bond flux is transported, it is possible to prevent pulverization, and it is possible to easily treat an empty container after use, such as folding.

[Brief description of drawings]

FIG. 1 is a graph showing a moisture absorption curve of flux.

FIG. 2 is a graph showing the relationship between the film thickness of a polymer film and water vapor transmission rate.

Claims (3)

[Claims] 1. A packaging material having an interior and an exterior, wherein the interior has a three-layer structure in which an inner layer, an intermediate layer and an outer layer are adhered to each other, and each of the inner layer and the outer layer has a thickness of 20 μm or more and has a thickness of 20 μm or more. A bond flux comprising a polymer film having a total thickness of 60 to 200 μm, the intermediate layer made of an aluminum foil having a thickness of 5 to 20 μm, and the outer package made of a flexible material. Packaging material. 2. The packaging material for bond flux according to claim 1, wherein the outer package is made of paper, rubber, cloth or polymer fiber. 3. A container for bond flux, which uses the packaging material for bond flux according to claim 1 or 2.