JPS6214940A - Preparation of oxygen scavenger - Google Patents

Abstract

PURPOSE:To obtain an oxygen scavenger capable of being prepared safely and having excellent capacity, by adding a solution of caustic soda in alcohol to a porous sheet like support having supported a deoxidizing main agent before sealing said support in an oxygen permeable film. CONSTITUTION:A solution prepared by dissolving a deoxidizing main agent such as a hydroanthraquinone compound or catechol in a proper solvent is infiltrated into an air permeable porous sheet or, according to circumstances, in an air impermeable porous sheet and the solvent is subsequently removed. The obtained sheet like support having supported the main agent is uniformly impregnated with a solution of caustic alkali in alcohol by coating and subsequently heat-sealed in an oxygen permeable film while the formed oxygen scavenger is sealed in a system to be deoxidized. As alcohol, polyhydric alcohol is pref. This oxygen scavenger can be prepared in an extremely safe manner and gently and sufficiently develops deoxidizing effect.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a method for producing a practically excellent oxygen scavenger.

``Prior art'' It is known that a laminate of a fiber sheet carrying organic compound powders such as ascorbic acid, sodium ascorbate, sodium erythorbate, pyrogallol, hydroquinone, and tannin and a sheet impregnated with an alkaline aqueous solution is used as an oxygen scavenger. (Special Publication No. 57-3416).

"Problems to be Solved by the Invention" However, in this invention, a sheet impregnated with an alkali as an aqueous solution is laminated with a sheet carrying an oxygen scavenging main agent. When this oxygen absorber is mixed and prepared with the above components, it immediately causes a violent deoxidation reaction, so there is a risk that it will absorb oxygen during the manufacturing process, reduce its deoxidizing ability, or burn, so it is not carried out under an inert gas. In addition, the obtained oxygen scavenger absorbs oxygen too quickly and has problems in storage and handling, making it impractical.

This publication discloses a method of dispersing powder of the main oxygen scavenger on the support as a method for supporting the oxygen scavenger on the support.In this method, the main oxygen scavenger is uniformly dispersed on the support. However, there were problems with the production process, which caused problems in the continuity of the manufacturing process.

Furthermore, impregnating separate supports with an oxygen scavenger and an alkali requires a large number of steps, resulting in high costs and is economically disadvantageous.

In order to research a method to overcome the drawbacks of such conventional methods, the present inventors have determined that the reaction is slow, that they are easy to handle during production and storage, and that they can be produced especially in air.
As a result of research aimed at obtaining a product that is not bulky, we found that a porous sheet such as paper that carries a main oxygen scavenging agent,
When the additive was added by spraying an alcoholic solution of caustic alkali and then sealed with an oxygen-permeable film, it was found that it can be handled extremely safely even in the air, and that even when used as an oxygen absorber, the system should be deoxidized very slowly. It has been discovered that it absorbs moisture in the atmosphere and removes oxygen, and also slowly removes oxygen from the system when there is insufficient moisture in the system to be deoxidized or even when there is almost no moisture present. The invention has been completed.

"Means and actions for solving the problems" The present invention is (
1) An oxygen scavenger characterized in that a caustic alkaline alcohol-soluble tFX is added to a sheet-shaped support carrying an oxygen-scavenging main agent, and then the sheet-shaped support is encapsulated in an oxygen-permeable film. It depends on the manufacturing method.

The main agent of the oxygen scavenger of the present invention generally includes organic reducing compounds. For example, hydroanthraquinone compounds, catechol, ascorbic acid, sodium scorbate, erythorbic acid, pyrogallol, hydroquinone, reducing I! Examples include neck and tannins.

As the hydroanthraquinone compound used as the main ingredient of the oxygen scavenger of the present invention, an anthraquinone hydride is preferably used6. For example, L4,4a,9a- Examples include tetrahydroanthraquinone, 1,4-dihydroanthrahydroquinone, and 1.4.4a, 5.8.8a, 9a, 10a-octahydroanthraquinone, but considering the production method etc., 1,4,4a , 9a-tetrahydroanthraquinone compounds are preferred.

Examples of the caustic alkali include caustic soda and caustic potash, but usually inexpensive caustic soda is used.

The amount of caustic alkali used is generally approximately 0 based on the base agent.
．． 0.01 times or more by weight, usually from about 0.05 times to 5 times by weight.

The sheet-like support used in the present invention is generally a porous support that is breathable and capable of absorbing liquid, but may be impermeable in some cases.

Examples of the breathable sheet-like support include fiber sheets such as Japanese paper, Western paper, nonwoven fabric, linen, hemp cloth, cotton cloth, chemical fiber cloth, mixed fiber cloth, and filter paper.

Examples of impermeable supports include generally flexible plates such as resin, or porous substances such as activated carbon, silica, silica gel, silica alumina, zeolite, and diatomaceous earth adhered thereto using known adhesives. can be mentioned.

The oxygen-permeable film used in the present invention can be sealed with an adhesive, but generally a heat-sealable film is used.

Examples include porous polyethylene film laminated paper bags, porous plastic films such as polypropylene, polybutadiene, polyester, polyvinyl chloride, cellophane, and laminate films thereof. Moreover, it is more preferable if it is water-impermeable. For example, there may be mentioned a film in which commercially available polyethylene or polypropylene is laminated on a nonwoven fabric so as to maintain water impermeability.

The method for supporting the base agent on these supports includes impregnating or spraying the above-mentioned support with a solution of the base agent,
The solvent can be removed by evaporation, or the base material can be supported as a powder alone or by adhering a mixture of the above-mentioned porous substance and adhesive substance, but in the present invention, the base material is dissolved and supported. For example, a solution of a polar solvent such as alcohol or an aromatic hydrocarbon such as benzene, toluene, xylene, etc. in a non-corrosive solvent (water may be used if necessary) or an aqueous caustic solution is added to each porous material. The method of impregnating the support and then removing the solvent is advantageous because it can be applied to a continuous method.

After adding an alcoholic solution of caustic alkali to the obtained sheet-like support carrying the main ingredient, it is generally heat-sealed with an oxygen-permeable film, and the inside of the system to be deoxidized is usually placed in an oxygen-impermeable bag. By enclosing it in a container or the like, it is possible to slowly absorb oxygen and deoxidize while absorbing moisture in the system.

The alcohol used as the solvent for the caustic alkaline solution in the present invention is preferably one that dissolves the caustic alkali well, such as monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and isopropyl alcohol; ethylene glycol, propylene glycol, Examples include liquid polyhydric alcohols such as glycerin, but polyhydric alcohols are preferably used particularly in order to proceed with the deoxidation reaction gently.

The amount of alcohol used varies depending on the desired deoxidation absorption rate, the type of polyhydric alcohol, the type of alkaline substance, and the amount used, but generally it is about 0.001 times the weight or more of the base ingredient or alkaline substance, usually is 0.0
05 to 2 times the weight.

The method for adding an alcoholic solution of caustic alkali is to apply the caustic alkaline solution to a sheet-like support carrying the main ingredient,
Known conventional methods such as dripping or spraying to impregnate as uniformly as possible can be used.

Until the final step of the manufacturing process, the oxygen scavenger of the present invention
Since the base agent and the alkaline substance do not come into contact with each other and contain almost no water, even if they come into contact with oxygen, there is no sudden reaction with oxygen, making it possible to produce an oxygen scavenger extremely safely.

Furthermore, the oxygen scavenger obtained by the method of the present invention has the advantage that if some moisture, such as moisture or water, is present in the system used, it will be absorbed by the oxygen scavenger and oxygen will react with it. The water produced by the reaction gradually increases the oxygen scavenging ability. Therefore, the oxygen scavenger of the present invention also has the function of reducing the humidity within the system. Even if there is insufficient moisture or almost no moisture in the applied system (for example, in the packaging of machinery, etc.), the presence of alcohol will ensure sufficient contact between the main oxygen scavenging agent and the alkali. Therefore, a gentle yet sufficient deoxidizing effect can be exerted.

"Effects of the Invention" The oxygen scavenger of the present invention safely and gently removes oxygen during the manufacturing process without losing its oxygen scavenging ability, making it possible to obtain a compact product that is not bulky. Furthermore, since it has a dehumidifying property, it lowers the humidity in the system to be deoxidized, and is extremely effective for rust prevention, mold prevention, and preservation. or,
By intervening alcohol such as polyhydric alcohol,
It has deoxidizing ability even in a system with almost no moisture. Furthermore, since both the base agent and the alkaline substance can be used in liquid form, the oxygen scavenger can be manufactured continuously and the manufacturing process can be simplified.

Next, the present invention will be explained in detail by way of examples. However, "%" and "parts" used in this specification indicate "% by weight" and "parts by weight" unless otherwise specified.

Example 1 +11 1.4a,9a-Tetrahydroanthraquinone impregnation into filter paper 1.4.4a,9a-Tetrahydroanthraquinone in 60x solution of ortho-xylene with 10 TOYO filter paper (No, 2°5.5cm φ) Soak for 1,4.4 minutes at room temperature.
After impregnating with a, 9a-tetrahydroanthraquinone solution, the solvent was evaporated to prepare a sheet-like support impregnated with the base agent.

The composition of the obtained 1,4,4a,9a-tetrahydroanthraquinone (THAQ)-impregnated filter paper was as follows.

(2) Impregnation of main and sub-impregnated sheet support with caustic soda Two types of caustic soda solutions were prepared as follows.

Solution A: NaOH-ethanol solution Ethanol 92% NaOH8χ Solution B: NaOH-ethylene glycol solution Ethylene glycol 93.0χ NaOH3,3X Water 3.7χ The caustic soda solution was applied to the base material-impregnated sheet prepared in (1) above with filter paper, respectively. Approximately 0.3 g of solution was impregnated per sheet to prepare an impregnated sheet-like support.

The amounts of caustic soda impregnated were as follows.

Solution A: approx. 0.6+aa+ol/sheet Solution B: approx. 0.25+i+aol/sheet+3+15L Oxygen test The above two types of sheet-like supports were each coated with an oxygen-permeable film (made of biaxially oriented polypropylene lined with heat-sealing material). For some, the breathability [Gare] is 35.)
I heat sealed it. 5.5 of the oxygen absorber prepared in this way
The equivalent amount was sealed in a 55kl glass bottle filled with dry air, and the amount of oxygen removed from the air in the experimental equipment was measured at room temperature.

The test results were as shown in Table 1.

Table 1 Of course, even in the case of non-dry air, oxygen can be easily removed by adjusting the amount of alkali.

Example 2 flI Impregnation of catechol into filter paper TOYO filter paper (N
o, 2.5.5c+aφ) at 30° C. for 10 minutes, and then the filter paper was dried under reduced pressure to prepare a base agent-impregnated sheet-like support.

The amount of catechol impregnated into this sheet-like support was as follows.

(2) Impregnation and deoxidation test of caustic soda on a sheet support impregnated with a base agent and deoxidation test Spray impregnation and deoxidation test of a sheet support impregnated with a base agent with caustic soda Regarding the amount of caustic soda impregnated into a filter paper, the method described in Example 1 ( 11 and (2), and the second
Obtained the results in the table.

Table 2 Patent applicant: Kawasaki Chemical Industries, Ltd. Representative: Hiroshi Maru Kawa 1, J

Claims (4)

[Claims] (1) On a porous sheet-like support carrying an oxygen scavenging main agent,
1. A method for producing an oxygen scavenger, which comprises adding an alcoholic solution of caustic alkali and then encapsulating the sheet-like support in an oxygen-permeable film. (2) The method according to claim 1, wherein the caustic alkali is caustic soda. (3) The method according to claim 1, wherein the main oxygen scavenging agent is a hydroanthraquinone compound, catechol, ascorbic acid, sodium ascorbate, erythorbic acid, pyrogallol, hydroquinone, reducing sugar, and tannin. (4) A porous sheet-like support supporting an oxygen scavenging main agent,
2. The method according to claim 1, which is obtained by impregnating a porous sheet-like support with a solution of an oxygen-reducing main agent and then removing the solvent.