JPS6214939A - Oxygen scavenger and its preparation - Google Patents

Abstract

PURPOSE:To obtain an oxygen scavenger excellent from a practical aspect, by respectively supporting a deoxidizing main agent and an alkaline compound by a sheet like support and laminating said support to form a laminate while impregnating said laminate with alcohol before sealing the same in an oxygen permeable film. CONSTITUTION:A solution of a deoxidizing main agent such as catechol or ascorbic acid (except a hydroanthraquinone compound) in alcohol or benzene and an aqueous caustic soda solution are respectively infiltrated into porous supports and the solvent is subsequently evaporated. At least one of the sheet like supports must has oxygen permeability. The obtained sheet like supports having supported the main agent and the alkaline substance are laminated and adhered under pressure and the obtained laminate is uniformly impregnated with alcohol such as ethylene glycol to be heat-sealed in an oxygen permeable film. This oxygen scavenger can be prepared in an extremely safe manner, gently and sufficiently develops deoxidizing effect by the interposition of alcohol.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a practically excellent oxygen scavenger and a method for producing the same.

``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 main deoxidizing agent is prepared by mixing the above-mentioned substances, a violent deoxidizing reaction occurs immediately, so there is a risk that it will absorb oxygen during the manufacturing process, reduce its deoxidizing ability, or burn. There are drawbacks such as the fact that it is difficult to implement or produce in a short period of time, and the obtained oxygen scavenger absorbs oxygen too quickly, causing problems in terms of storage and handling, making it impractical.

Furthermore, as a method for supporting the oxygen scavenging agent on the support, a method has been disclosed in which powder of the oxygen scavenging agent is dispersed on the support, but this method has problems in uniformly dispersing the oxygen scavenging agent onto the support. However, there were problems in industrial continuity.

Furthermore, impregnating separate supports with the deoxidizing main agent and the alkali increases the cost 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 non-bulky product, the main oxygen scavenging agent (excluding hydroanthraquinone compounds) was supported on a porous sheet such as paper, and an alkaline substance was also supported on the sheet. By laminating them together and intervening a polyhydric alcohol, and then encapsulating them with an oxygen-permeable film, it was found that they can be handled extremely safely even in the air, and that even when used as an oxygen absorber, they are very gentle in the atmosphere of a system that needs to be deoxidized. The present invention was completed by discovering that it is possible to remove oxygen by absorbing moisture, and to slowly remove oxygen from the system even when there is insufficient moisture or almost no moisture in the system to be deoxidized. did.

"Means and actions for solving the problems" The present invention is (
1) After laminating a sheet-like support carrying an oxygen scavenging main agent (excluding a hydroanthraquinone compound) and a sheet-like support carrying an alkaline compound, and further intervening alcohol in the laminate, An oxygen scavenger consisting of a laminate sealed in an oxygen permeable film and at least one of its sheet-like supports is oxygen permeable; (2) an oxygen scavenger main agent (excluding hydroanthraquinone compounds); , ) and an aqueous solution of an alkaline compound were impregnated into each porous sheet-like support, and after removing the required amount of organic solvent and water, these support sheets were laminated, and alcohol was further interposed. Thereafter, there is a method for producing an oxygen absorber characterized by encapsulating it in an oxygen permeable film.

The main agent of the oxygen scavenger of the present invention generally includes organic reducing compounds such as catechol, ascorbic acid, sodium ascorbate, erythorbic acid,
Examples include pyrogallol, hydroquinone, reducing sugars, and tannins, but catechol is preferred in consideration of price, effectiveness, etc.

Examples of the alkaline substance include caustic soda, caustic potash, soda carbonate, and potassium carbonate, but usually, inexpensive caustic soda is used.

The amount of the alkaline substance to be used is generally selected from about 0.01 times or more, usually about 0.05 times or more and 5 times or less by weight, relative to the base agent.

The sheet-like supports used in the present invention are divided into two types: those that support the base agent and those that support the alkaline substance. Generally, both are porous and have similar breathability and can absorb liquid, but in some cases, at least one is breathable and the other is impermeable. There may be.

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.

The impermeable support may be, for example, a generally flexible plate made of resin or the like, or a porous substance such as activated carbon, silica, silica gel, silica alumina, zeolite, or diatom adhered thereto using a known adhesive. Things 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 has water impermeability. 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 or the alkaline substance on these supports includes impregnating or spraying the above-mentioned support with a solution of the base agent or the alkaline substance, respectively;
The base material of the present invention can be supported by a method of removing the solvent by evaporation, or by adhering the base material or an alkaline substance alone or by adhering a mixture of the above-mentioned porous material and adhesive substance, but the base material of the present invention does not dissolve the base material. For example, a solution dissolved in a polar solvent such as alcohol or a non-polar solvent such as aromatic hydrocarbons such as benzene, toluene, xylene (water may be used if necessary) or an aqueous caustic solution is added to the respective porosity. A method in which the 28y8 medium is impregnated into a support and then evaporated is advantageous because it can be applied to a continuous method.

The thus obtained sheet-like supports carrying the base agent or alkaline substance are laminated and pressed together, a polyhydric alcohol is interposed in this laminate, and then the laminate is appropriately cut and generally heat-sealed with an oxygen permeable film. By enclosing the system in which oxygen is to be deoxidized, usually in an oxygen-impermeable bag or container, it is possible to slowly absorb oxygen and deoxidize while absorbing moisture in the system.

Examples of the alcohol used in the present invention include monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and isopropyl alcohol; and liquid polyhydric alcohols such as ethylene glycol, propylene glycol, and glycerin. Polyhydric alcohol is preferably used to gently advance the process.

The intervening method is to impregnate the base material-containing support and/or alkaline substance-containing support with alcohol as uniformly as possible by coating, dropping, or spraying, or by applying an appropriate amount of alcohol to a porous sheet. Examples include a method in which the sheet is impregnated with the base material and the base material-containing support is laminated and brought into close contact with the sheet. Alternatively, a method may be adopted in which one sheet is impregnated in advance with or sprayed with an alcoholic solution of the base agent or caustic alkali to produce a sheet impregnated with the base agent or caustic alkali and alcohol at the same time.

The amount of alcohol used can vary depending on the desired oxygen removal and absorption rate, the type of alcohol, the type of alkaline substance, and the amount used, but generally it is about 0.001 times the weight of the main ingredient or alkaline substance. Above, it is usually o, oos to 2 times the weight.

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, this oxygen scavenger may contain some moisture in the system in which it is used.
For example, if moisture or moisture is present, it is absorbed by the oxygen scavenger and reacts with oxygen, and 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 lowering the humidity in the cough system, and should be noted when there is insufficient moisture or almost no moisture in the system to which it is applied (for example, when packaging machinery, etc.). ), the presence of alcohol brings the main oxygen scavenging agent into sufficient contact with the alkali, so that a gentle yet sufficient oxygen scavenging 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 Impregnation of catechol into filter paper TOYO Filter (N
0, 2.5.5 cm φ) 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 of filter paper with caustic soda Add TOYO filter (No.

After soaking 2.5.5 cm φ) at room temperature (approximately 24° C.) for 10 minutes, the filter paper was dried to prepare an alkali-impregnated sheet-like support.

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

Weight of impregnated caustic soda - 0.3 g/sheet (7.5 + u + ol) sheet) (31 Impregnation of ethylene glycol into alkali-impregnated sheet-like support It was impregnated by spraying at a rate of g/sheet.

(4) Oxygen removal test After the above two supports were closely laminated with the ethylene glycol-impregnated filter paper prepared in (3) sandwiched between them, an oxygen permeable film (made of biaxially oriented polypropylene and lined with a heat-sealing material) was layered. In some cases, the air permeability [Gurley] is 35) and heat sealed. 5 of the oxygen absorber prepared in this way
．． The equivalent of 5 sheets was sealed in a 550 ml 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 amount of oxygen inside was 8.3% after half a day, and about 1.4% after one day.
After 2 days it was almost gone.

Example 2 An oxygen scavenger was prepared in the same manner as in Example 1 except that glycerin was used instead of ethylene glycol as the polyhydric alcohol. As a comparative example, an oxygen scavenger without polyhydric alcohol was prepared.

The oxygen scavenger was subjected to an oxygen scavenging test using the same experimental apparatus as in Example 1.

Experimental temperature was 20-24℃ The experimental results are shown in the table below.

Patent applicant: Kawasaki Chemical Industries, Ltd. Representative: Hiroshi Maru Kawa.

゛(Otsu-

Claims (5)

[Claims] (1) After laminating a sheet-like support carrying an oxygen scavenging main agent (excluding a hydroanthraquinone compound) and a sheet-like support carrying an alkaline compound, and interposing alcohol in the laminate, An oxygen scavenger comprising a laminate sealed within an oxygen-permeable film, and at least one of the sheet-like supports is oxygen-permeable. (2) The method according to claim 1, wherein the alkaline substance is a caustic alkali. (3) The method according to claim 2, wherein the caustic alkali is caustic soda. (4) The method according to claim 1, wherein the main oxygen scavenging agents are catechol, ascorbic acid, sodium ascorbate, erythorbic acid, pyrogallol, hydroquinone, reducing sugars, and tannins. (5) After impregnating each porous sheet support with an aqueous solution of an oxygen scavenging agent (excluding hydroanthraquinone compounds) and an alkaline compound, and removing the required amount of organic solvent and water, these support sheets are A method for producing an oxygen scavenger, which comprises laminating layers, intervening alcohol, and then encapsulating it in an oxygen-permeable film.