JPH04297588A - Method for storing metal and product containing metal, and their storage state - Google Patents

Abstract

PURPOSE:To maintain complete storage state without causing corrosion when metal products and products containing metal are transported or stored, especially transported by ship or plane. CONSTITUTION:Metal products or products containing metal are sealed in a gas-barrier type container with packing material and natural pulp products. This packing material consists of a compsn. containing unsatd. fatty acid compds. and/or linear hydrocarbon polymers having unsatd. groups and this compsn. is wrapped with an air-permeating material. By this method, even when the storing conditions (temp. and humidity) remarkably change during the metal products or products containing metal are transported by ship or plane, deposition of dew on the metal surface is prevented and production of rust can be suppressed. Thus, complete storage which is difficult by conventional technique can be realized.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a preservation method and a preservation form when transporting or storing metals and products containing metals (hereinafter simply referred to as metals), and particularly relates to a preservation method when transporting from overseas by ship or airplane. This invention relates to laws and storage formats.

0002

[Prior Art] When a shadow mask made of iron or a thin plate made of copper alloy or iron-nickel alloy is plated with silver or gold on a part or all of its surface, the surface rusts when exposed to air, and is susceptible to dust contamination and printing. Problems such as reduced solder adhesion to the board arise. Moisture condenses on the metal surface due to sudden changes in temperature and humidity, especially when transported overseas by ship or plane, promoting rust. The following methods can be used to prevent the occurrence of rust.

[0003]1. Shortened shelf life Each metal is manufactured in different locations, which keeps transportation and warehouse storage between locations short. However, this method requires excessive equipment and personnel because planned production cannot be carried out. In particular, when metals are produced overseas and transported by ship or plane, transportation takes time, and rapid changes in temperature and humidity during transportation can cause moisture to condense on the metal surface, which can cause rust. Ta.

2. Method using gas replacement Japanese Patent Application Laid-Open No. 1-139370 proposes a method of replacing the air in the container with nitrogen gas. However, this method also has problems, such as the need for special equipment for gas replacement, the difficulty in efficiently replacing gas in the container, and the difficulty in achieving the goal even if a large amount of nitrogen gas is used. It had

3. Method of using nitrogen gas replacement and a desiccant in combination A method of using nitrogen gas replacement and a desiccant in combination is proposed in JP-A-1-139380. However, this method is also described in 2. I had the same problem as in the case of .

[0006] Furthermore, using a desiccant alone cannot completely prevent moisture from condensing on the metal surface due to sudden changes in temperature and humidity during transportation due to increased humidity in the system due to moisture permeating through the packaging material. It was difficult. As mentioned above, none of the conventional techniques can completely achieve the purpose of metal preservation, and it is difficult to stably supply metals such as lead frames and shadow masks, especially when they are transported from overseas. This was the most difficult problem.

[0007]

[Problem to be Solved by the Invention] In view of the above-mentioned problems in the technology, the present inventors have attempted to make it possible to transport or store metals to foreign countries in a perfect manner without rusting. As a result of intensive research, we have arrived at the following invention.

[0008]

[Means for Solving the Problems] That is, the present invention provides packaging in which a composition containing a metal, an unsaturated fatty acid compound and/or a chain hydrocarbon polymer having an unsaturated group is packaged in an air-permeable packaging material. This involves sealing the body and natural pulp together in a gas-barrier container.

[0009] In the present invention, a composition containing an unsaturated fatty acid compound and/or a chain hydrocarbon polymer having an unsaturated group is a composition for absorbing oxygen, moisture, and acidic substances in a container. It contains one or more of a desiccant, an adsorbent, a basic substance, and a catalyst in addition to an unsaturated fatty acid compound and/or a chain hydrocarbon polymer having an unsaturated group. The unsaturated fatty acid compound and/or the chain hydrocarbon polymer having an unsaturated group used in this composition are the main ingredients for absorbing oxygen in the storage container.

[0010] A catalyst is a substance that promotes the absorption of oxygen by an unsaturated fatty acid compound as a main ingredient or a chain hydrocarbon polymer having an unsaturated group, and includes a transition metal or its compound, a radical initiator, etc. can be given.

The unsaturated fatty acid compound used herein is a fatty acid compound having 10 or more carbon atoms and a double bond between the carbon atoms, and is an unsaturated fatty acid, a salt thereof, or an ester thereof. Furthermore, the unsaturated fatty acid compound does not necessarily have to be a pure substance, and the unsaturated fatty acid, its salt, and its ester may have a substituent, such as a hydroxyl group or a formyl group.

Examples of unsaturated fatty acids and their compounds include oleic acid, linoleic acid, linolenic acid, arachidonic acid, parinaric acid, dimer acid, ricinoleic acid, and ricinoleic acid, as well as fats and oils containing these esters, esters, Examples include metal salts.

[0013] Furthermore, the chain hydrocarbon polymer having an unsaturated group refers to a substance having 10 or more carbon atoms and one or more double bonds between carbon atoms, and derivatives thereof, and has particularly low viscosity and molecular weight. Not limited. As a substituent of each derivative, for example, a hydroxyl group, a formyl group, etc. may be present. Specific examples include polymers such as butadiene, isoprene, piperylene, and 1,3-pentadiene.

The chain hydrocarbon polymer having an unsaturated group does not necessarily have to be a pure substance, and may be a mixture of two or more of unsaturated fatty acids and their salts, unsaturated aliphatic hydrocarbons, or their derivatives. . Preferably, a transition metal salt of an unsaturated fatty acid or a mixture of a transition metal salt of an unsaturated fatty acid and an unsaturated fatty acid, and/or a transition metal salt of an unsaturated fatty acid or a mixture of a transition metal salt of an unsaturated fatty acid and an unsaturated fatty acid. , to which a hydrocarbon polymer having an unsaturated group is added.

[0015] The basic substance in the composition of the present invention is:
There is no particular limitation as long as it absorbs acidic substances that diffuse through the storage container or acidic substances that are generated in the reaction of unsaturated fatty acid compounds and/or chain hydrocarbon polymers having unsaturated groups with oxygen. However, preferred are alkali metal or alkaline earth metal oxides, hydroxides, carbonates, organic acid salts, and organic amines.

[0016] An adsorbent is an adsorbent that carries an unsaturated fatty acid compound and/or a chain hydrocarbon polymer having an unsaturated group to increase the contact area with oxygen and increase the oxygen absorption rate. There are no particular limitations on the material as long as it absorbs one or more of substances and moisture, but examples include paper made of natural pulp or synthetic pulp, synthetic paper, silica gel, activated carbon, zeolite, activated clay, etc. can give.

[0017] The content ratio of the constituent components of the composition in the present invention is not particularly limited, but includes unsaturated fatty acid compounds and/or
or a chain hydrocarbon polymer having an unsaturated group 100
Based on parts by weight, the catalyst is 0.01 to 10 parts by weight, the basic substance is 1 to 1000 parts by weight, and the adsorbent is 10 to 1000 parts by weight.
Preferably, it consists of parts by weight. Further, the shape of these compositions is not particularly limited, but examples include granules, tablets, and sheets.

[0018] The above composition has an oxygen permeation rate of 1000 ml.
/m2 ・atm ・Day or more, moisture permeability is 1g/m
Pack with breathable packaging material of 2 days or more. The structure and material of this breathable packaging material are not particularly limited, but
Specifically, it is a film or sheet, and a film laminated on a base material of paper or nonwoven fabric. This air-permeable packaging material is filled with a composition, and the periphery of the packaging material is adhered by a method such as heat sealing to form an oxygen absorbent package.

[0019] The above package further has an oxygen permeability of 1000.
ml/m2 ・atm ・Day or more, moisture permeability 1g/
It may be double-packed in an air-permeable packaging material that has a diameter of 0.3 μm or more and has a dust collection efficiency of 50% or more when air is passed through it. The shape and form of this package is not particularly limited, but examples include a pouch, a sheet, and a blister package.

[0020] The gas barrier container according to the present invention has an oxygen permeation rate of 10 ml/day per 100 ml volume.
Hereinafter, preferably it is 5 ml/Day or less, and the moisture permeation rate is 10 g/m2 ·Day or less, preferably 5 g/m2 ·Day or less, and the shape, material, etc. are not limited. Examples include containers made of synthetic resin and metal. Metal cans preferably made of iron, tinplate, stainless steel, aluminum, polyethylene, polypropylene, nylon, polyester, vinyl chloride,
Cases made of synthetic resins such as polystyrene and polycarbonate, laminated layers of several materials such as vinyl chloride, vinylidene chloride, aluminum foil, vapor-deposited aluminum, vapor-deposited silicon oxide, vapor-deposited cerium oxide, nylon, polyethylene, polypropylene, polyester, etc. For example, a bag made of a composite film obtained by the above method is sealed by means such as heat sealing.

[0021] The oxygen absorber package sealed together with metal in these containers can be prepared by providing a storage section in the container and loading the package into the container, or by wrapping the metal in paper or plastic film and loading the package adjacent to it. Or, it is glued and fixed inside the container and sealed. The oxygen absorbent package storage section provided in this container has an oxygen permeation rate of 1000ml/m2 ・atm
・Film or Gurley type air permeability of 1 day or more
It is made by laminating films on a base material of microporous film, paper, or nonwoven fabric, and is used to isolate metals.

[0022] Also, when sealing the metal and packaging body in a container
The air inside the container may be replaced with nitrogen gas, etc. Furthermore, the pressure inside the container may be reduced. Antistatic agents may also be added to the materials of these containers. Furthermore, when using a metal can or a case made of synthetic resin, a gasket can be inserted between the main body and the lid to improve gas barrier properties.

[0023] The material made of natural pulp used in the present invention is a material that absorbs excess moisture and prevents condensation from occurring on the metal surface within the packaging system when the temperature and humidity of the atmosphere changes rapidly. be. In addition, by sandwiching something made of natural pulp between metals, it is used to efficiently remove moisture in the gaps from the system. Materials made of this natural pulp include, but are not particularly limited to, kraft pulp, thermomechanical pulp, etc. Preferably, the pH of water extracted from the pulp is 4 to 1.
0, the amount of sulfur and chlorine is 100 ppm or less and the water content in the pulp is 12% or less, more preferably the water extraction pH is 5.5 to 8.5, and the amount of sulfur and chlorine is 50
Examples include those with a water content of ppm or less and a water content in the pulp of 6% or less. Although the shape of this pulp product is not particularly limited, it is preferably sheet-like. This sheet has a basis weight of 20 to 300 g/m2, and is used in the form of being sandwiched between metals or wrapped.

A lead frame is a typical example of metals and products containing metals in the present invention. This lead frame is to be bonded to an IC chip, and is made by polishing the surface of a molded copper alloy (physical polishing and chemical polishing), and partially plated with silver and gold.

[0025]

[Example] Example 1 1 g of soybean oil fatty acid iron, 0.2 g of slaked lime, and 1.0 g of powdered activated carbon.
5g was mixed with a cutter mixer and left to stand at 25°C for 10 minutes to form a lump. This mass was crushed to obtain a granular composition. 2.7 g of this composition and 2.5 g of silica gel were weighed separately and filled into a pouch (size, 5 x 7.5 cm) made of breathable packaging material (paper/perforated polyethylene), and then heat-sealed around the pouch. In this way, an oxygen absorbent package was manufactured. This package was heated for 250 m of air containing various gases.
A polyvinylidene coated stretched nylon/polyethylene (KON/PE) bag (size, 15 x 24
cm). When this bag was stored in an atmosphere of 35° C. and 80% RH, changes in the concentration of each gas over time were measured. The results are shown in Table 1.

Comparative Example 1 A desiccant package was manufactured from 2.5 g of silica gel using the same method and materials as in Example-1. Changes in the concentration of each gas in the bag over time were measured in the same manner as in Example 1 except that a desiccant package was used instead of the rust preventive package in Example 1. The results are shown in Table 1.

[0027]

[Table 1]

Example 2 Copper alloy thin plate (thickness 1.27 x width 62 x length 200 mm)
was punched out using a press, and the surface was etched with an aqueous solution of sulfuric acid and hydrogen peroxide. Gold is attached to the IC chip adhesive part of this lead frame, and 3 bundles of 50 chips each are bundled.
Wrapped in polypropylene film, and further made with a sheet made of natural pulp (manufactured by Hokuyo Paper Co., Ltd., product name NS-150,
It was packaged with a water extraction pH of 7, a water content of 3%, a basis weight of 150 g/m2, a width of 300 mm, and a length of 400 mm. This wrapped item is placed in a polypropylene case (width 70 x length 200 mm)
× height 50 mm) together with the oxygen absorbent package produced in Example 1, and this was placed in a KON/PE bag (size 1
70 x 300 mm). This lead frame was sealed and placed in an atmosphere of 25°C and 50% RH.
After confirming that the oxygen concentration in the bag is below 0.01%, store it at 50℃ and 95% RH for 2 days, then store it at 0℃ and R.
It was stored in an atmosphere with 100% H and one cycle was 5 days. The copper alloy surface of the lead frame was observed after storage. The results are shown in Table 2. Additionally, Tables 3 and 4 show changes in system humidity and system oxygen concentration over time during storage.

Example 3 The oxygen absorbent package produced in Example 1 was hermetically packaged with a lead frame in the same manner as in Example 2, except that natural pulp was not used. This product was stored in the same manner and under the same conditions as in Example 2, and the copper alloy surface of the lead frame after storage was observed. The results are shown in Tables 2, 3 and 4.

Comparative Example 2 A lead frame was hermetically packaged in the same manner as in Example 2, except that the desiccant package produced in Comparative Example 1 was used instead of the oxygen absorbent package in Example 2. This product was stored in the same manner and under the same conditions as in Example 2, and the copper alloy surface of the lead frame was observed. The results are shown in Table 2. Additionally, Tables 3 and 4 show changes in system humidity and system oxygen concentration over time during storage.

Comparative Example 3 The lead frame was sealed in the same manner as in Comparative Example 2, except that when sealing the KON/PE bag in Comparative Example 2, the air inside the bag was replaced with nitrogen gas until the oxygen concentration reached 2.7%. was sealed and stored. The surface of the lead frame copper alloy after storage was observed. The results are shown in Tables 2, 3 and 4.

[0032]

[Table 2] Note 1) Discoloration status of alloy surface -
No discoloration + Very light discoloration Very slight discoloration + Very light discoloration
More than half of the area +++ Dark discoloration
More than half of the area +++++ Dark discoloration Almost the entire surface Note 2) There was evidence of water condensation on the metal surface, but there was no particularly noticeable discoloration.

[0033]

[Table 3]

[0034]

Example 4 Copper alloy thin plate (thickness 1.27 x width 62 x length 200 mm)
was punched out using a press, and the surface was etched with an aqueous solution of sulfuric acid and hydrogen peroxide. Gold is attached to the IC chip adhesive part of this lead frame, and 3 bundles of 50 chips each are bundled.
Wrapped in polypropylene film, and further made with a sheet made of natural pulp (manufactured by Hokuyo Paper Co., Ltd., product name NS-150,
It was packaged with a water extraction pH of 7, a water content of 3%, a basis weight of 150 g/m2, a width of 300 mm, and a length of 400 mm. This wrapped item is placed in a polypropylene case (width 70 x length 200 mm)
x height 50 mm) together with the rust preventive package produced in Example 1, and a KON/PE bag (size 170 x 30 mm).
0 mm). This lead frame was sealed and stored in an atmosphere of 30°C and 50% RH for one day, and after confirming that the oxygen concentration inside the bag was 0.01% or less, it was shipped by sea from Singapore for one month. In short, it was transported within Japan. When we observed the copper alloy surface of the lead frame after transportation, there was no discoloration due to condensation or rust on the metal surface.
It was in good condition.

Comparative Example 4 A desiccant was sealed and packaged together with a lead frame in the same manner as in Example 2, except that the desiccant package produced in Comparative Example 1 was used instead of the oxygen absorbent package in Example 3. When this product was stored in the same manner as in Example 3 and the copper alloy surface of the lead frame was observed, it was found that the entire surface was discolored to blue-black, and there were spots of dew condensation in some areas, making it unusable. Met.

Comparative Example 5 The lead frame was sealed in the same manner as in Comparative Example 4, except that when sealing the KON/PE bag in Comparative Example 4, the air inside the bag was replaced with nitrogen gas until the oxygen concentration reached 2.7%. was sealed and stored. When the surface of the lead frame copper alloy was observed after storage, there was a blue-black discoloration on the entire surface, and there were some spots with dew condensation.

[0038]

[Effects of the Invention] The method of the present invention prevents dew condensation on the metal surface and suppresses the occurrence of rust even when storage conditions (temperature and humidity) change rapidly during transportation of metal by plane or ship. This enabled preservation that was not possible with technology. This improvement in preservation allows metals to be produced in a planned manner, and even when transported by ship or plane from overseas, metals can be preserved in perfect condition without rusting.

Claims (1)

[Claims] Claim 1: A package consisting of a metal and a product containing the metal wrapped in a breathable packaging material containing a composition containing an unsaturated fatty acid compound and/or a chain hydrocarbon polymer having an unsaturated group; A method and form for preserving metals and products containing metals, characterized by sealing them in a gas-barrier container together with a material made of pulp.