JP2001206311A - Method for preserving hydrophobic substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent method and an excellent container for preserving a hydrophobic substance to maintain the inside of the preserving container at a low humidity. SOLUTION: In the method for preserving the hydrophobic substance, the hydrophobic substance and a gas generation source are stored in the same container, and in the container for preserving the hydrophobic substance, the gas generation source is stored inside, and a container seal portion is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing a water repellent substance and a container for storing a water repellent substance.

[0002]

2. Description of the Related Art As packaging techniques for preserving water-repellent substances, degassing packaging (vacuum packaging), dehumidification gas replacement packaging, and hermetically sealed packaging enclosing a desiccant such as silica gel or quick lime are known. I have.

In the case of degassing packaging, the objects to be packaged are limited to those that are not deformed by compression or a force applied to the surface of the packaging, or those that do not change their commercial value even if they are deformed.

In the case of dehumidified gas replacement filling packaging, it is required that the packaging container be impermeable to water vapor. Since water vapor is permeable in commonly used synthetic resin bottles, synthetic resin film packaging, and the like, when packaging by such means, it is necessary to provide a metal layer or to make the joint non-water permeable.

In the case of hermetically sealed packaging containing a desiccant, water vapor in the container at the time of packaging and water vapor permeating through the container are captured by the desiccant, but since the amount of water vapor in the container does not become less than a certain amount, drying is performed. Has limitations. In addition, it is necessary to select a desiccant that has a water absorption capacity higher than the water-repellent substance. Thus, the method of preserving a water-repellent substance in the prior art was not sufficient.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an excellent method for storing a water-repellent substance and a container for storing a water-repellent substance, which can maintain the inside of the storage container at a low humidity. It is in.

[0007]

That is, the gist of the present invention is as follows.
[1] A method for storing a water-repellent substance in which a water-repellent substance and a gas generating source are stored in the same container, and [2] a gas generating source is stored in the container and a container sealing portion (hereinafter simply referred to as a seal) And a container for storing a water-repellent substance.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A water aversion substance to be stored is a substance whose commercial value is reduced by moisture absorption and water absorption.
For example, desiccants such as silica gel, foods such as confectionery, shavings, powder detergents, electronic equipment, iron processed articles, metals or articles that oxidize in the presence of water, substances that react and change in the presence of water, and products containing electronic circuits And the like.

In the present invention, the water aversion substance is stored by storing the water aversion substance and the gas generating source in the same container. As a specific storage means, there is a means for storing a water-repellent substance or the like by using a packaging technique such as degassing packaging (vacuum packaging), dehumidification gas replacement packaging, or airtight packaging.

[0010] The material of the container is better as the gas barrier property is higher,
In particular, the lower the carbon dioxide gas permeability, the oxygen gas permeability, and the moisture permeability, the better. Carbon dioxide permeability ^{100 cc / m 2 · 24hrs ·} atm (25
° C., RH 50%) or less, the oxygen gas permeability 50cc / m ² · 24hrs
・ Atm (25 ℃, 50% RH) or less, moisture permeability 200 g / m ²・ 24
hrs (40 ° C., 90% RH) or less is more preferable. The measurement of the transmittance and the moisture permeability were performed according to JIS K 7126 and JIS, respectively.
According to K 7129.

Examples of the material used for the container include aluminum composite films, aluminum-deposited films, silicon oxide-deposited films, aluminum oxide-deposited films, vinylon-based films, lacquer-coated films, polyvinylidene chloride-coated films, and the like. Aluminum composite films, aluminum-deposited films, silicon oxide-deposited films, aluminum oxide-deposited films, and vinylon-based films are preferable, and aluminum composite films, aluminum-deposited films, silicon oxide-deposited films, and aluminum oxide-deposited films are particularly preferable.

The container for storing a water-repellent substance of the present invention is a container in which a gas generating source is housed and which has a container seal portion. Keep the pressure inside the container higher than the pressure outside the container,
In addition, a structure in which the gas in the container flows out to the outside is preferable, and a structure in which the gas in the container flows out from the container seal portion is more preferable.

The shape of the container is not particularly limited as long as it can be used for packaging techniques such as degassing packaging (vacuum packaging), gas replacement filling packaging, airtight packaging, etc., and is in the form of a bag (standing pouch, pillow, gusset). Etc.), box shape, cup shape and the like. Above all, a bag shape is preferable from the viewpoint of easily providing a seal portion. The size of the container is not particularly limited.

The shape of the seal portion cannot be unequivocally limited depending on the shape and size of the container, but examples include a heat seal. Further, the position and the number of the seal portions in the container cannot be unconditionally limited.

A gas generating source is a substance that generates a gas other than water vapor in a container during storage. Preferably, they are an azo compound, a peroxide, a gas retention substance, and a decomposition gas generation substance, and more preferably, a gas retention substance and a decomposition gas generation substance. Specifically, azo compounds such as azobisisobutyronitrile, peroxides such as dilauroyl peroxide and ditertiary butyl peroxide, sublimable substances such as camphor and naphthalene, carbon dioxide occluding zeolites, nitrogen gas occluding zeolites and the like And gas-decomposed substances such as bleached powder, isocyanuric chloride and the like.

Aluminosilicate used as carbon dioxide occluding zeolite and nitrogen gas occluding zeolite is amorphous,
Although any of a partial crystal type and a crystal type can be used, a crystal type is preferred. Specifically, natural aluminosilicates such as mesolite and chabazite, and synthetic zeolites designated by names such as zeolite A, X and Y are used. In particular, a synthetic zeolite represented by the following general formula, which contains few impurities such as impurities, is preferable. _{(M 2 / mO) x ·} Al 2 O 3 · (SiO 2) y · (H
During ₂ O) _z (wherein, M is a metal atom of valency m, x is 0.7 to 1.
5, y is 0.8 to 1.0, and z is a number of 0 or more. )

Among the synthetic zeolites of the general formula, examples of the metal atom represented by M include sodium, potassium, calcium, magnesium and the like, and z is preferably 0, that is, substantially free of water. The size of the gas occlusion zeolite is preferably 0.5 to 100 μm, more preferably 1 to 40 μm in particle size. Examples of the usage form of the gas-occluding zeolite include fine powder having the above-mentioned particle diameter as it is, granules, pellets, and the like. Fine powder is preferred from the viewpoint of effects.

Carbon dioxide or nitrogen gas is adsorbed on the gas-storing zeolite to obtain a carbon dioxide-storing zeolite or a nitrogen-storing zeolite. Examples of the adsorption method include a method in which a gas occlusion zeolite is brought into contact with carbon dioxide gas or nitrogen gas. Gas storage zeolite used here,
For example, the aluminosilicate is preferably dehydrated by a heat treatment and optimally contains substantially no water. The adsorption is preferably carried out under anhydrous conditions, at a gas pressure of 0.1 kg / cm ² or more, suitably 1-1.
It is performed at 0 kg / cm ² . The temperature is 30 ° C. or lower, preferably 20 ° C. or lower, and the time is not particularly limited, but the reaction is preferably performed until equilibrium is reached.

The amount of gas adsorbed on zeolite is preferably 2 g gas / 100 g zeolite or more, and 5 g gas / 10 g
More than 0 g zeolite is more preferable.

The gas is generated by storing the gas generation source in the container. The mechanism of gas generation is not particularly limited. For example, by reacting with water, by self-disintegration (decomposition), by acid, alkali, etc., by sublimation,
Alternatively, gas may be generated by release from a gas retaining material.

The gas to be generated is not particularly limited as long as it is a gas other than water vapor, and a gas that does not deteriorate the quality of the water-repellent substance is more preferable. Specifically, nitrogen gas,
Examples include helium gas, neon gas, argon gas, krypton gas, xenon gas, carbon dioxide gas, oxygen gas, hydrogen gas, and mixed gas (dehumidified air). The gas may be a single gas or a mixture of two or more gases. Preferred are nitrogen gas and helium gas, and particularly preferred is nitrogen gas.

The volume of the content to be stored is 50 to 9 times the maximum filling volume of the container from the viewpoint of suppressing solidification and preservation stability.
5% is preferable, 60-95% is more preferable, and 70-95% is preferable.
95% is more preferred. Here, the “maximum filling volume of the container” refers to the volume of a true sphere having a surface area equal to the surface area of the container. The term “content” refers to a substance other than the gas present in the container, and specifically refers to a substance including all of a water-repellent substance, a gas generation source, and the like. The volume of the content can be determined by a gas replacement method at 1 atmosphere and 20 ° C.

The amount of the gas generating source is preferably 0.1 to 20 parts by weight, and more preferably 0.5 to 20 parts by weight based on 100 parts by weight of the water aversion substance.
10 parts by weight is more preferable, and 0.5 to 5 parts by weight is particularly preferable. 0.1 parts by weight or more is preferable from the viewpoint of stable storage of the water repellent substance, and 20 parts by weight or less is preferable from the viewpoint of economy.

In the present invention, it is more preferable that the pressure in the container is kept higher than the pressure outside the container, and that the gas in the container is stored while flowing out to the outside. This is because keeping the pressure inside the container higher than the pressure outside the container has an effect of preventing external water vapor from entering the inside of the container. Further, it is preferable to store the gas in the container while allowing the gas to flow out to the outside, since the effect of discharging the internal water vapor to the outside is exhibited.

The difference between the pressure inside the container and the pressure outside the container is 10 to
1000 hPa is preferable, 50 to 800 hPa is more preferable, and 100 to 500 hPa is particularly preferable. The pressure is preferably 10 hPa or more from the viewpoint of stable storage of the water-repellent substance, and is preferably 1000 hPa or less from the viewpoint of the strength of the container, the adhesive strength of the seal portion, economy, and the like.

Normally, gas is generated from the stored gas generating source. Therefore, in order to make the internal pressure of the container higher than the external pressure of the container, the amount of the gas generating source, the permeability of the container, and the like may be appropriately set so that, for example, the gas generation amount ≧ the gas outflow amount.

The outflow method of the gas inside the container is as follows.
The gas may be discharged from the entire surface of the container by utilizing the permeability of the container, or a part of the container may be provided with a part from which gas flows out more easily than other parts. In the latter case, selective gas permeation is also possible, and can be achieved, for example, by using a container having a container seal portion and making the container seal portion a sealing method in which gas easily flows out. The gas permeability of the material of the container is low, and the gas outlet is preferably a seal or a part of the container, and more preferably the gas outlet is a seal. When the seal portion is a gas outflow portion, the gas may flow out as an incomplete seal. As a specific structure of the seal portion, a structure in which a material having high gas permeability is sandwiched and sealed is given. As a material with high gas permeability,
Low density polyethylene, high density polyethylene, undrawn polypropylene, polyester, polycarbonate, polyvinyl chloride, polystyrene and the like are preferred. Here, “a material having a high gas permeability” means that the carbon dioxide gas permeability is 100 cc / m ² · 24.
hrs ・ atm (25 ℃, 50% RH) and / or oxygen gas permeability exceeding 50cc / m ²・ 24hrs ・ atm (25 ℃, 50% RH)
A material that exceeds

In the present invention, it is preferable that the water aversion substance and the gas generating source be stored in a gas-filled package. The gas-filled package is a package in which air filled at the same time as filling a water-repellent substance is replaced with an inert gas and filled. Examples of the gas filling and packaging method include a nozzle type, a chamber type, and a gas flush type. Among them, the chamber type and the gas flash type are preferable. By gas-filling and packaging a water-repellent substance, connection of incense tone, suppression of solidification and discoloration, and generation of insolubles can be suppressed, and as a result, the water-repellent substance can be stably stored for a long period of time. Therefore, it is preferable.

The gas to be filled may be the same as the gas generated by the gas generating source. Here, from the viewpoint of the stability of the water repellent substance, the gas replacement ratio is preferably 80% by volume or more, more preferably 90% by volume or more, further preferably 95% by volume or more, and particularly preferably 99% by volume or more.

[0030]

EXAMPLES Example 1 In a combination shown in Table 1, a water-repellent substance and a gas generating source were filled and packaged with nitrogen gas and stored in a container. The material of the container is non-stretched nylon 50 μm, and the carbon dioxide gas permeability is 90
^{cc / m 2 · 24hrs · atm} (25 ℃, RH 50%), the oxygen gas permeability ^{20cc / m 2 · 24hrs · atm} (25 ℃, 50% RH), a moisture permeability of 150 g / m ² · 24hrs ( 40 ° C., 90% RH) and nitrogen gas permeability was 7 cc / m ² · 24 hrs · atm (25 ° C., 50% RH). The packaging method was pillow packaging, and a gas outlet was provided at the seal portion. And temperature 40 ° C, humidity 80%, pressure 1h
It was stored for 3 months in a constant temperature and humidity chamber of Pa, and the water content after storage of the water aversion substance and the water content before storage were compared. An example in which the water content increased due to storage was evaluated as x, an example in which there was almost no change was evaluated as ○, and an example in which the water content decreased was evaluated as ◎. Table 1 shows the results. The structure of the gas outlet of the seal part is low-density polyethylene 25 μm.
To seal the gas so that gas flows out of the seal.

The water content of the water repellent substance was determined by measuring the change in weight of a sample after taking 3 g of the sample and drying it at 105 ° C. for 3 hours.

COMPARATIVE EXAMPLE 1 A water-repellent substance and silica gel were used in place of a gas generating source, and these were stored in a container in the same manner as in Example 1. Then, the change in the water content was examined by the same evaluation method as in Example 1. Table 1 shows the results.

[0033]

[Table 1]

Table 1 shows that the water aversion substance and the gas generation source are the same.
When storing in the same container, even after storing for 3 months
It can be seen that the water content does not increase. In addition, 10A type zeo
Nitrogen gas in the light 4kg / cm^TwoPressure
After adsorbing elemental gas, the nitrogen gas occlusion zeolite
Nitrogen gas adsorption amount is 20gN _Two/ 100g zeolite
Was. In addition, 4 kg / CO 2 gas was added to 10A zeolite.
cm^TwoWhen the carbon dioxide gas is adsorbed by applying the pressure of
The carbon dioxide adsorption zeolite has a carbon dioxide adsorption of 19 gCO
_Two/ 100 g zeolite. As peroxides,
Dilauroyl peroxide was used. Water repellent substances and comparison
The silica gel used in the examples was manufactured by Katayama Chemical Industry Co., Ltd.
Lica gel (blue, medium grain, 5-10 mesh) was used.

[0035]

According to the method for storing a water-repellent substance of the present invention, the water-repellent substance can be maintained at a low humidity.

Claims (5)

[Claims] 1. A method for storing a water-repellent substance in which a water-repellent substance and a gas generating source are stored in the same container. 2. The storage method according to claim 1, wherein the pressure in the container is kept higher than the pressure outside the container, and the gas in the container is stored while flowing out. 3. The storage method according to claim 2, wherein a container having a container seal portion is used, and the gas in the container flows out of the container seal portion to the outside. 4. The storage method according to claim 1, wherein the water aversion substance and the gas generating source are gas-filled and packaged in a container. 5. A container for storing a water-repellent substance, in which a gas generating source is housed and a container seal portion is provided.