JP2003334049A - Label type deoxidant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a label type deoxidant suitable for preserving a much water-containing food. <P>SOLUTION: This label type deoxidant is characterized by using a laminate film comprising (A) a non-porous waterproof moisture-permeable resin film which has a waterproof property having a water resistance of ≥2,000 mmH<SB>2</SB>O and a moisture-permeable property having a water permeation degree of ≥1,000 g/m<SP>2</SP>/24 hr and (B) a finely porous film as an air-permeable layer. The production of rusts from the sheet-like deoxidant can be prevented. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a label-type oxygen scavenger for sticking and fixing using a sheet-shaped oxygen scavenger composed of a resin composition containing an oxygen scavenger composition. The present invention relates to a label-type oxygen scavenger having improved water resistance when applied to food by imparting the property.

[0002]

2. Description of the Related Art In order to prevent deterioration due to oxygen and spoilage due to the growth of microorganisms and to maintain quality, a deoxidizer is used for deoxidation packaging of foods, pharmaceuticals, and other products that are easily affected by oxygen. Oxygen packaging is widespread. For this deoxidizing packaging, a deoxidizing agent pouch in which a granular or powdered deoxidizing agent is packed in a breathable pouch is usually used, but recently, for example, iron powder-based deoxidizing agent is used. A sheet-shaped oxygen scavenger having excellent oxygen scavenging performance has been developed, which has an oxygen scavenger resin sheet formed by mixing a powdery oxygen scavenger with a thermoplastic resin and molding the mixture (Patent Document 1).

The above-mentioned sheet-shaped oxygen absorber can be produced as a multilayer body in which a sheet-shaped oxygen absorber fixed with a thermoplastic resin is coated with a film or a sheet coating material. Compared with the small bag type oxygen absorber, there is no risk of the oxygen absorber powder leaking due to bag breakage, and since it has a thin flat shape with a uniform thickness, it is suitable for automatic sticking equipment. . Focusing on the characteristics of the form and the multilayer structure of the sheet-shaped oxygen scavenger, as a sticking-fixable oxygen absorber provided with an adhesive layer on one surface of the sheet-shaped oxygen scavenger, a base layer having an adhesive layer, A label-type oxygen scavenger in which the oxygen scavenging layer and the air permeable layer are laminated in this order, and the air permeable layer is directly adhered to the base layer at the outer peripheral edge of the oxygen scavenging layer without exposing the oxygen scavenging layer is proposed. Has been done. (Patent Document 2,
3)

However, in the conventional label-type oxygen scavenger containing iron as the main component of the oxygen scavenger, in order to secure the oxygen scavenging performance by increasing the air permeability in the gas permeable layer located on the surface in contact with the stored article. In addition, since a porous material that has been subjected to treatment such as opening with a needle or porosification by stretching is usually placed on it, when used for a package of foods containing a large amount of water, depending on the use conditions, the water may be aerated. In some cases, the sheet-shaped oxygen absorber permeates into the sheet-shaped oxygen absorber through the holes on the surface of the conductive layer to dissolve the oxygen absorber component and rust, and this may exude to the outer surface of the label oxygen absorber, impairing the appearance of the package. In order to solve these problems, using a non-porous film in the breathable layer, by absorbing oxygen by oxygen permeation from the cross section, it is known as a known technique to prevent the appearance of rust, In the case of a moisture-dependent sheet-shaped oxygen scavenger containing iron as the main agent, it is necessary to allow moisture, which is indispensable for the progress of the deoxidation reaction, to permeate together with oxygen from the cross section, which slows down the oxygen scavenging rate. There was a problem.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2-72851

[Patent Document 2] Japanese Patent Laid-Open No. 7-219430

[Patent Document 3] Japanese Patent Laid-Open No. 10-290915

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a label-type oxygen scavenger in which the oxygen scavenger component and rust are not likely to seep to the outer surface of the label-type oxygen scavenger even when applied to foods containing a large amount of water. The purpose is to provide an agent.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a label-type oxygen scavenger has a waterproof property with a water pressure resistance of 2,000 mmH2O or more and a moisture permeability of 1,000 g / by using a laminated film comprising a combination of a waterproof moisture-permeable resin film and the microporous membrane having both m ^2/24 hours or more breathable, can solve the above problems without decreasing the oxygen velocity The present invention has been completed based on this finding.

According to the present invention, a base layer having an adhesive layer, a sheet-shaped oxygen absorber made of a deoxidizing resin obtained by blending a deoxidizing agent with a thermoplastic resin, and a breathable layer are laminated in this order, and
A label-type oxygen scavenger in which the base layer and the breathable layer are adhered to each other in the peripheral portion of the sheet-shaped oxygen absorber, wherein the breathable layer is (A) waterproof with a water pressure resistance of 2,000 mmH ₂ O or more. characterized in that it comprises a combination of preparative moisture permeability 1,000g / m ^2/24 hours or more waterproof and permeable resin film having both moisture permeability (B) a microporous film, label type oxygen having improved water resistance Regarding agents. The present invention also relates to a label-type oxygen scavenger web in which a plurality of label-type oxygen scavengers are adhered to a strip-shaped separator layer by an adhesive layer of a base layer.

The label-type oxygen scavenger of the present invention mainly comprises a base layer provided with an adhesive layer / a sheet-shaped oxygen scavenger composed of a oxygen scavenger in which an iron-based oxygen scavenger is dispersed in a thermoplastic resin / a breathable layer. As a component. The configuration will be described in detail below.

(1) Breathable layer The breathable layer covers the sheet-shaped deoxidizer to prevent direct contact with the object to be preserved, and the oxygen absorber mixed in the sheet-shaped deoxidizer removes oxygen. It is a layer having a function of appropriately permeating water vapor and oxygen for absorption. Breathable layer in the present invention, (A) Water pressure 2,000mmH ₂ O or more waterproof and waterproof and permeable resin film having both moisture permeability 1,000g / m ^2/24 hours or more breathable (B) It consists of a substantially non-porous laminated film consisting of a microporous membrane. As the breathable layer, (A) the waterproof and moisture-permeable resin film is arranged on the side of the outside air and the contained article, and (B) the microporous membrane is arranged on the sheet-shaped deoxidizer side.

(A) The waterproof moisture-permeable resin film has a water pressure resistance of 2,000 mmH ₂ O or more and a moisture permeability of 1,000 g / m ² /
It is a thermoplastic resin film for 24 hours or more. Water pressure resistance of 3,000 mmH ₂ O or more, moisture permeability of 2,000 g / m ² /
24 hours or more is preferred and water pressure resistance is 4,000
mmH ₂ O or more, and more preferably the amount of moisture permeation is 2,500g / m ^2/24 hours or more.

The water pressure resistance is measured according to the JIS-L-1092B method (high water pressure method). Water pressure resistance is 2,000m
When it is less than mH ₂ O, when used in foods containing a large amount of water, excess water permeates into the label type oxygen scavenger to cause rust, or the oxygen absorption capacity decreases, and the label type There is a problem that the rust generated in the oxygen scavenger leaks out.

The moisture permeability is measured in accordance with JIS-Z-0208 under the conditions of 40 ° C.-90% relative humidity. When the amount of moisture permeation is less than 1,000g / m ^2/24 hours, water is not sufficient to be supplied to the sheet-like oxygen scavenger through breathable layer, there is a problem that oxygen speed.

The thickness of the waterproof and moisture-permeable resin film (A) is not particularly limited as long as the above-mentioned waterproofness and moisture permeability are obtained, but in view of securing physical strength and flexibility, it is 2
μm or more and 200 μm or less is preferable, and 10 μm or more and 10 μm or more
A thickness of 0 μm or less is more preferable.

As the material of the waterproof moisture-permeable resin film (A), a film of polyetheramide block copolymer system is used from the viewpoint of moisture permeability, price, affinity with other resins, and the like. The polyetheramide block copolymer is a copolymer obtained by copolycondensation of a polyether unit having a reactive group terminal and a polyamide unit having a reactive group terminal. Specifically, it is a polyetheramide block copolymer having a repeating unit represented by the formula (1).

[-(C = O) -X- (C = O) -OY-O-] _n (1) In the formula (1), X is a linear saturated aliphatic polyamide chain, It is produced from a lactam or amino acid having a hydrocarbon chain of 4 to 14 carbon atoms, or an aliphatic dicarboxylic acid of 6 to 12 carbon atoms and an aliphatic diamine of 6 to 9 carbon atoms, and has an average molecular weight of 300 to 15,000. Y is a polyoxyalkylene chain, is composed of one or more linear or branched aliphatic polyoxyalkylene glycols, and has a molecular weight of
It is less than 6,000. n is a sufficient number of repeating units so that the polyetheramide block copolymer has an intrinsic viscosity of 0.8 to 2.05. Those described in US Pat. No. 4,331,786 can be used.

As the waterproof and moisture-permeable resin film (A), a thermoplastic resin film which is not substantially perforated on the surface or inside thereof is used. (A) Waterproof and breathable resin film has high water pressure resistance, so it can prevent water other than water vapor from entering the oxygen absorber, so rust occurs due to excess water entering the oxygen absorber. It is possible to suppress deterioration of oxygen absorption performance.

The microporous membrane (B) is made of a porous material having high air permeability and is a film laminated on the sheet-shaped deoxidizer side of the waterproof moisture-permeable resin film (A). (B) Since the oxygen permeability of the microporous membrane is high, even if the oxygen permeability of (A) the waterproof moisture-permeable resin film is not necessarily high, sufficient desorption is achieved by oxygen permeation from the end cross section of the microporous membrane. The oxygen rate can be obtained.

The material for forming the (B) microporous membrane may be any material having high oxygen permeability, and examples thereof include water resistant nonwoven fabric, polyolefin microporous film, and synthetic paper.
Among these, a nonwoven fabric made of a thermoplastic resin is preferable in terms of breathability, moisture permeability, water repellency, tear strength, and the like. Materials of the thermoplastic resin nonwoven fabric include polyolefin type, polyester type, polyamide type and the like, and further, there are types such as spun bond, melt blow, carding and air lay depending on the manufacturing method. Also,
The cross-sectional structure includes a single structure and a core-sheath structure. Among these, polyolefin-based or polyester-based nonwoven fabrics are more preferred, and high-density polyethylene spunbonded nonwoven fabrics are most preferred. Since the high-density polyethylene spunbonded non-woven fabric has a low melting point, it has an advantage that it can be easily adhered when it is laminated with the base layer by heat adhesion by heat sealing.

The oxygen permeability of the microporous membrane is represented by air permeability. The air permeability of the microporous membrane is measured by the Gurley air permeability measuring method defined in JIS-P-8117 and is 1000 seconds / 100 cc or less, preferably 500 seconds / 100 cc or less. (B) The thickness of the microporous membrane is not particularly limited as long as oxygen permeability is obtained, but from the viewpoint of ensuring physical strength and flexibility, it is preferably 10 μm or more and 1000 μm or less, and 30 μm or more and 500 μm or less. Is more preferable.

The breathable layer may be composed of a laminate composed only of (A) the waterproof and moisture-permeable resin film and (B) the microporous membrane, and may be composed of other components within a range not impairing the respective characteristics and functions. It may be composed of a laminated body with other one or more layers. As a method for producing a laminated body, a known laminated film producing method such as a dry laminating method using an adhesive or extrusion lamination is used. By configuring the breathable layer with such a configuration, it is possible to compensate for insufficient moisture supply by permeation only from the cross section of the microporous membrane by permeation from the waterproof moisture-permeable resin film surface, and thus to the oxygen absorption reaction. Sufficient water can be supplied to the sheet-shaped oxygen absorber, and a label-type oxygen absorber with a high oxygen removal rate can be obtained even if the surface of the breathable layer is non-porous.

Printing may also be added to the breathable layer. In that case, it is preferable that (A) the waterproof and moisture-permeable resin film is printed, and then a transparent film having a hole is additionally laminated as the outermost layer. Also, (A)
Using a transparent film as a waterproof and moisture-permeable resin,
A method of providing a printing layer on the back surface of the resin film (A) is also preferable. By such a method, it is possible to prevent the printing ink from coming into contact with the stored article.

The breathable layer in the label-type oxygen absorber has a size larger than that of the sheet-shaped oxygen absorber in order to prevent the cross-section of the sheet-shaped oxygen absorber from being exposed, and an adhesive layer is provided at the outer peripheral portion of the sheet-shaped oxygen absorber. It is preferable to adhere to the base layer. Figure 1
An example is shown in FIG. The breathable layer may or may not be adhered to the sheet-shaped deoxidizer, but in the case of fixing by adhesion, the adhering portion substantially vents water vapor or oxygen to the sheet-shaped deoxidizer. Be careful not to disturb them.

(2) Sheet-shaped oxygen absorber The sheet-shaped oxygen absorber is composed of a deoxidizing resin composition in which a deoxidizing agent is dispersed in a thermoplastic resin, and the deoxidizing resin composition has at least one axial direction. It is a microporous sheet-like small piece stretched into a sheet.

The thermoplastic resin used in the deoxidizing resin layer is preferably an olefin resin, and examples thereof include low density polyethylene, high density polyethylene, polypropylene, ethylene-α-olefin copolymer, and polymethylpentene.

As the deoxidizer, for example, a metal-based deoxidizer containing a metal component typified by iron powder as a main component, and an organic component such as ascorbic acid, polyhydric alcohols and polyphenols as a main component. The organic oxygen scavenger can be used. In particular, an iron powder type oxygen absorber is preferable. The iron powder-based oxygen scavenger is composed of a composition containing iron powder and a metal halide salt, and in particular, an iron powder whose surface is coated or dispersed with a metal halide salt is preferably used. The composition is
Further, if necessary, auxiliary components such as activated carbon, lime, diatomaceous earth, zeolite and inorganic salt can be contained.

Examples of the iron powder used in the iron powder type oxygen scavenger include reduced iron powder, electrolytic iron powder, sprayed iron powder, etc. The iron powder particles are preferably fine, and particularly, the average particle size is 200 μm.
The following is preferable, and an average particle diameter of 150 μm or less is more preferable. Examples of the metal halide include sodium chloride, potassium chloride, barium chloride, calcium chloride, magnesium chloride, sodium bromide, potassium bromide, barium bromide, calcium bromide, magnesium bromide, sodium iodide, potassium iodide. , Barium iodide, calcium iodide, magnesium iodide and the like are used. The metal halide is used in an amount of 0.1 to 15 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of iron powder.

The sheet-shaped oxygen absorber is kneaded with the oxygen absorber at a ratio of 85 to 25% by weight with respect to 15 to 75% by weight of the thermoplastic resin, melted into a sheet, and stretched in at least one axial direction. Manufactured. The draw ratio is preferably 1.5 to 15 times, more preferably 3 to 12 times. The sheet-shaped oxygen absorber is made microporous by stretching. The thickness of the sheet-shaped oxygen absorber obtained by stretching is appropriately selected according to the purpose and application, but is usually in the range of 0.05 to 3 mm.

In order for the label type oxygen absorber of the present invention to have a practical level of oxygen eliminating performance as a single-sided absorption type sheet oxygen absorber, the oxygen absorbing rate of the sheet oxygen absorber is preferably 100 ml / m ^2. / Hr (25 ° C.) or more, more preferably 200 ml / m ² / Hr (25 ° C.) or more, and it is achieved by selecting the stretching conditions in the above range to make the sheet oxygen absorber microporous. .

The sheet-shaped oxygen scavenger is not limited to the oxygen scavenger contained therein, the manufacturing method, etc., as long as the oxygen scavenger is suitable for the purpose. Specifically, a sheet prepared by dispersing a deoxidizer composition containing a reducing inorganic or organic material as a main component in a thermoplastic resin, or a transition metal such as cobalt or iron in a thermoplastic resin such as polyolefin or polyamide. Examples thereof include a sheet in which a catalyst is dispersed. Among them, from the viewpoint of deoxidizing performance, a resin sheet containing an oxygen scavenger composition of the iron powder main agent is preferable, and particularly, a resin sheet in which the oxygen scavenging composition of the iron powder main agent is dispersed in a thermoplastic resin is stretched to be microporous. A converted sheet is preferably used.

In the present invention, the above sheet-shaped oxygen absorber can be imparted with flexibility by subjecting it to further incision processing or opening treatment. The above sheet-shaped oxygen absorber that requires water for the oxygen absorption reaction can be used as a water-dependent oxygen absorber or a self-reactive oxygen absorber.
It is preferable to use it as a moisture-dependent oxygen scavenger that utilizes moisture evaporated from the object to be stored, from the viewpoint of production and handling.

Further, layers such as a moisture absorption layer, a water retention layer, a gas adsorption layer, a gas generation layer and a deodorization layer can be added separately to the sheet-shaped deoxidizer. In this case, care should be taken not to impair the oxygen absorption performance of the sheet-shaped oxygen absorber. For example, the separately provided layer is laminated and adhered to the surface of the sheet deoxidizer opposite to the surface facing the breathable layer. Further, ventilation holes are provided in a layer separately provided or a layer separately provided and its adhesive layer, and the sheet-shaped deoxidizer and the breathable layer are placed or adhered and laminated. In particular, it is important to secure the moisture permeability of (A) the waterproof moisture-permeable resin film and (B) the oxygen permeability of the microporous membrane.

In particular, the deodorizing effect can be obtained by laminating the deodorizing layer on the sheet-shaped oxygen absorber. The deodorizing layer is made of a breathable material containing a deodorant. Activated carbon is preferred as the deodorant. The activated carbon used for the deodorizing layer has a particle size of 20.
200 mesh under powder activated carbon passing through 0 mesh sieve is preferable, and 350 mesh under fine powder activated carbon passing through 350 mesh sieve is more preferable. Examples of the breathable material include filter paper, cellulose pulp, cellulose woven cloth, non-woven cloth and the like. Examples of the method for adhering the deodorizing layer include an extrusion laminating method, a dry laminating method, and a hot melt adhering method which are usually used, and the extrusion laminating method is particularly preferable.

Examples of preferable deodorizing layer include activated carbon-containing paper (hereinafter referred to as activated carbon paper) prepared by mixing powdered activated carbon and a binder whose main component is pulp, and non-woven fabric in which fibrous activated carbon and resin fibers are mixed. To be Activated carbon paper is preferable in terms of cost and handleability. The activated carbon content of the activated carbon paper is preferably 5% by weight or more.

(3) Base layer: The base layer is a layer interposed between the sheet-shaped oxygen absorber and the separator layer. The base layer usually consists of a base material and an adhesive layer. The base layer and the separator layer are releasably adhered to each other via an adhesive layer fixed to the base layer. The base layer and the sheet-shaped oxygen absorber may be adhered via an adhesive layer, but may not be adhered. The base layer is bonded to the (B) microporous membrane of the breathable layer at the outer peripheral portion of the sheet-shaped oxygen absorber via the adhesive layer.

It is also possible to use the adhesive layer alone as the base layer and to interpose it between the sheet-shaped oxygen absorber and the separator layer. In this case, the base layer (adhesive layer) is the sheet-shaped oxygen absorber on the back surface of the sheet-shaped oxygen absorber,
(B) The microporous membrane is bonded to the outer periphery of the sheet-shaped oxygen absorber.

The pressure-sensitive adhesive layer used for the base layer is made of a pressure-sensitive adhesive and plays a role of bonding the base layer and a separator layer described later. Further, when the label-type oxygen absorber is used, it plays a role of sticking and fixing the label-type oxygen absorber in the packaging container after peeling the separator layer. The adhesive layer, as a main component, for example, from the group consisting of acrylic type, styrene-isoprene-styrene type, styrene-butadiene type, styrene-butadiene-styrene type, styrene-ethylene / butylene-styrene type copolymers and block copolymers. It is preferable to use at least one selected adhesive or a combination of these adhesives. Further, in order to adjust the adhesive strength, an additive such as a tackifier may be appropriately added in addition to these main components. As a means for providing the adhesive layer, known conventional methods such as coating and laminating can be applied.

As the base material used for the base layer, a plastic film, non-woven fabric, paper or the like is used. The base layer is formed by providing an adhesive layer on one surface of the base material and an adhesive layer on the other surface, if necessary. In particular, a method in which a thermoplastic resin film is laminated on a base material to form an adhesive layer capable of heat sealing with the breathable layer is also a preferable configuration.

In the case of using the base material as the base layer, various indications can be printed on the surface of the base material on the adhesive layer side and a transparent adhesive can be used to provide the function of the display label. In this case, the printed display of the product name, notes, etc.
It can be easily confirmed from the outside of the transparent package with the label type oxygen absorber attached inside. In addition, the use of an opaque base material for printing, an opaque base material, or an opaque adhesive layer or an adhesive layer keeps the aesthetic appearance of hiding the inside of the label-type oxygen scavenger, and increases the commercial value. It is preferable in the sense that it does not damage.

The adhesive layer plays a role of adhering the base layer and the microporous membrane (B) of the air permeable layer at the peripheral portion of the sheet-shaped oxygen absorber. The term "adhesion" used in the present invention means that both surfaces to be adhered are fixed, including adhesion by a pressure-sensitive adhesive, adhesion by various adhesives and hot-melt agents, and heat-sealing by heat fusion. The same applies to the case. As a means for providing the adhesive layer, known conventional methods such as coating and laminating can be applied.

(4) Separator layer: The separator layer serves to protect the adhesive surface of the base layer before use, and also functions as a support for the web in which the label-type oxygen scavenger is connected. It is peeled off when the oxygen agent is used. As the separator layer, paper, film, metal foil or the like coated with a release agent such as silicone resin or paraffin wax can be used. The type of the release agent is selected so as to obtain an appropriate releasability according to the characteristics of the adhesive layer provided on the base layer.

The material of the separator layer may be any material as long as it satisfies the mechanical strength required for the production and use of the label type oxygen absorber or the continuous label type oxygen absorber, and it may be mixed with other layers depending on the processing conditions. Rigidity, shrinkage ratio, hygroscopicity, etc. are appropriately selected so that a dimensional difference occurs between them, and warpage, peeling, etc. do not occur. Generally, paper is used, but in order to cope with the recent movement of dust-free food manufacturing environment, it is preferable to use a plastic film or a metal foil that does not generate paper powder during processing.

In the label-type oxygen scavenger of the present invention, the separator layer, the base layer having an adhesive surface, the sheet-shaped oxygen absorber and the breathable layer are laminated. Further, a label-type oxygen absorber is continuously bonded to the strip-shaped separator layer to form a continuous body (web) of the label-type oxygen absorber.

The label-type oxygen scavenger of the present invention is flat, has a smooth and thin surface, has sufficient flexibility, has good sticking and fixing properties, and does not feel foreign matter. Its thickness is usually 0.1 to 5
It is selected from the range of mm, preferably from 0.2 to 3 mm, but it is preferably thinner so as not to hinder the winding of the continuous body and the handling with a sticking machine. Further, the shape of each piece can be freely selected, for example, a square, a rectangle, a circle, an ellipse, etc. according to the purpose of use.

Each of the label-type oxygen scavengers of the present invention comprises a breathable layer ((A) waterproof moisture-permeable resin film / (B) microporous membrane) / sheet oxygen absorber / adhesive layer / base layer / adhesive layer. The basic structure of the central part is the breathable layer ((A) waterproof / moisture permeable resin film / (B)
(Microporous film) / adhesive layer / base layer / adhesive layer is the basic constitution of the peripheral portion of the sheet oxygen absorber. If a deodorant layer is provided between the breathable layer and the base layer, (A) the moisture permeability of the waterproof moisture-permeable resin film and (B) the oxygen permeability of the microporous membrane are ensured for the sheet-shaped oxygen absorber. However, it is possible to add other layers.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION For producing the label-type oxygen scavenger of the present invention, for example, the following method is adopted. (Method 1) A sheet-shaped deoxidizer is adhesively fixed to the adhesive surface of a separator layer-containing base layer having an adhesive surface exposed on the other side and a separator layer adhered on one side in advance, and then a breathable layer is formed on the base layer as a base layer. Are completely overlapped with each other and the outer edge of the sheet-shaped oxygen absorber is pressed to completely bond the breathable layer to the base layer. Then, the outer edge of the sheet-shaped oxygen absorber is die-cut (semi-blanked) from the top to the base layer with a die, and finally, the outer base layer and breathable layer are separated from the separator layer while leaving the label-type oxygen absorber. Peeling off produces a label-type oxygen absorber web.

(Method 2) The separator layer is adhered to the pressure-sensitive adhesive applied on one surface to prepare a base layer with a separator layer having a heat-sealing agent surface exposed on the other surface. The sheet-shaped deoxidizer and the breathable layer are superposed on the heat-sealant surface of the base layer with the separator layer. A heating jig having a predetermined shape is pressed against the peripheral portion of the sheet-shaped oxygen absorber from above, and the base layer and the breathable layer are heat-bonded to each other at the outer edge of the sheet-shaped oxygen absorber. Finally, the outer edge of the sheet-shaped oxygen absorber is half-punched from the top to the base layer with a punching die, and finally, the outer base layer and the breathable layer are peeled off from the separator layer while leaving the label-type oxygen absorber. A label-type oxygen scavenger web is produced.

(Method 3) A sheet-shaped oxygen absorber is adhered to a pressure-sensitive adhesive having breathability and moisture permeability applied to the (B) microporous membrane surface of the breathable layer. On top of this, a base layer made by adhering a separator layer to the adhesive applied to the back surface is overlaid, and the base layer and the breathable layer are applied to the microporous membrane surface of the base layer and the breathable layer at the outer peripheral portion of the sheet-shaped oxygen absorber (B). Adhesion is performed via a pressure-sensitive adhesive that has water vapor permeability and moisture permeability. Finally, the label-shaped oxygen scavenger is manufactured by half-drawing the outer edge of the sheet-shaped oxygen absorber with a cutting die and peeling off the half-extracted outer part from the separator layer.

By any of the above methods, a label-type oxygen scavenger continuous body (web) in which the label-type oxygen scavenger is intermittently continuous on the strip-shaped separator layer can be manufactured. It is also possible to make it continuous. Of course, in the above-mentioned method, individual label-type oxygen scavenger products can be obtained by not half-drawing but by cutting the die through the separator layer. Also, individual products can be manufactured by cutting the continuous body. The method for producing the label-type oxygen scavenger of the present invention is not limited to the above method as long as it satisfies the requirements of the present invention.

[0049]

[Example 1]

<Manufacture of breathable layer> Polyetheramide block copolymer resin (manufactured by Elf Atochem Co., Ltd.) was placed on a band of high-density polyethylene spunbonded nonwoven fabric (manufactured by DuPont, product name “Tyvek”) fed by an extrusion laminating device. ,
Product name "PEBAX MV3000SA"; Water pressure resistance 1
0,000mmH ₂ O, moisture permeation amount 5,000g ^/ m ^2/24
Time) was extruded at an extrusion speed of 25 kg / hour, the line speed was adjusted so that the film thickness was 25 μm, and the resin film was laminated and then pressure-bonded by a nip roll. By slitting this, it consists of (A) non-porous polyetheramide block copolymer waterproof moisture-permeable resin film / (B) high-density polyethylene spunbonded nonwoven fabric (microporous membrane),
A long strip-shaped breathable layer film having a thickness of 25 μm was obtained.

<Production of sheet-shaped oxygen absorber> Iron powder (average particle size 70 μm) 100 coated with calcium chloride at a ratio of 2.5 parts by weight of calcium chloride to 100 parts by weight of iron powder 100
Parts by weight and 40 parts by weight of high-density polyethylene are kneaded and extruded to form a sheet-shaped deoxidizing resin composition, which is then stretched 5 times in the longitudinal direction to form a microporous band-shaped deoxidizing resin sheet (thickness: 0. 6 mm) was manufactured. The oxygen absorption rate of this deoxidized resin sheet is 200 ml O ₂ / m ² / Hr or more (25 ° C.)
Met.

4 m of the obtained original oxygen-absorbing resin sheet
The sheet was pressed through a roll provided with parallel lattice-shaped blades at m intervals, and the parallel lattice-shaped notches were made on one side of the raw sheet at a cut depth such that the thickness of the remaining portion of the sheet was 0.06 mm. Subsequently, the cut raw sheet was die-cut into a rectangle, and a black gray rectangular sheet-shaped oxygen absorber (long side 2
0 mm × short side 18 mm, thickness 0.6 mm) was prepared.

<Production of Base Layer Film with Separator Layer> As the base layer, a strip-shaped (width 36 mm) long rayon non-woven fabric having a basis weight of 40 g / m ² was used, and an acrylic adhesive was applied to both surfaces thereof. One of the layers coated with an adhesive is referred to as an adhesive layer, and the other is referred to as an adhesive layer. On the adhesive layer, a strip-shaped long release paper of the same width dimension coated with silicone on both sides was attached as a separator layer. This is called a base layer film with a separator layer.

<Production of Label-type Oxygen Absorber> First, in the first step, the adhesive layer on the other side of the strip-shaped long base layer film with a separator layer coated with the adhesive is
The sheet-shaped oxygen absorber with the cut-out surface facing upward (the side not to be attached) was used, with the short side of the rectangle perpendicular to the band direction.
It was stuck intermittently with a parallel spacing of 5 mm. In the second step, the sheet-shaped deoxidizer is sandwiched on the base layer from the previous step, the strip-shaped long breathable layer film is stacked, and the peripheral portion of the sheet-shaped deoxidizer is pressed against the adhesive layer surface of the base layer. Then, the breathable layer and the base layer were bonded to each other in the peripheral portion of the rectangular sheet-shaped oxygen absorber via the adhesive layer. In the third step, a punching die (rectangular; long side 32 mm x short side 30 mm) is lowered from the top to the bonding portion between the breathable layer and the base layer in the peripheral portion of the sheet-shaped deoxidizer, and the lowermost separator layer is placed. The bonded portion composed of the breathable layer / adhesive layer / base layer / adhesive layer was punched out into a rectangle. In the fourth step, the air-permeable layer / adhesive layer / base layer / adhesive layer around the stripped rectangular sheet type deoxidizer was left behind, and wound around a plastic core (diameter 130 mm). It was taken and made into a roll body. Thus, a label-type oxygen scavenger continuous body (web) in which a rectangular label-type oxygen scavenger (long side 32 mm × short side 30 mm) is adhered to the separator layer on a strip-shaped separator layer (release paper) Got a roll.

<Evaluation> Deoxidation performance test KON (15 μm) / PE (20 μm) / LLDPE
(60 μm) consisting of a gas barrier film, a three-sided seal bag (inner dimension 100 mm × 100 mm), the label-type oxygen scavenger separator layer was peeled off and the adhesive surface was attached to the label, and the label was attached. The mold oxygen absorber was fixed. Distilled water in a bag with this label type oxygen absorber attached.
5 ml of impregnated cotton and 50 ml of air were put into the bag, and the bag mouth was heat-sealed to make a bag. Similarly, 3 packaging bags were prepared and stored in a room at 25 ° C. 15 hours later,
When the oxygen concentration in the bag space was measured by a gas chromatograph, all three bags were deoxygenated to less than 0.1% by volume.

Food packaging test KON (15 μm) / PE (20 μm) / LLDPE
(60 μm) A three-sided sealing bag (180 mm × 250 mm) made of a gas barrier film is peeled off from the label-type oxygen scavenger separator layer, and the adhesive surface is attached to the label-type oxygen scavenger. The agent was fixed. Approximately 50 g of sliced ham was placed in a bag to which this label type oxygen absorber was adhered, and the bag mouth was heat-sealed together with 50 ml of air and sealed. This sliced ham package is placed so that the sliced ham is directly placed on the label-type oxygen absorber, and the barrier film surface to which the label-type oxygen absorber is attached is placed on the lower side, and further on the sliced ham. Put a water bag of about 200g as a weight through the gas barrier film,
The label type oxygen absorber was brought into close contact with the sliced ham. In the same manner, five sliced ham packages in which sliced ham was directly placed on the label type oxygen absorber were prepared. These packages were stored at 5 ° C. After 30 days, the appearance state of the label type oxygen scavenger and the sliced ham was observed.
No abnormalities were found on the surface of the label type oxygen scavenger and the appearance of the sliced ham in both the bags.

[Example 2] When a sheet-shaped oxygen absorber was prepared, sodium bromide was used as the salt for coating the iron powder.
A label-type oxygen scavenger was prepared and evaluated in exactly the same manner as in Example 1 except that the proportion of sodium bromide was 2.5 parts by weight relative to 00 parts by weight. When the oxygen removal performance was measured in the same manner as in Example 1, the oxygen content in the bag was less than 0.1% by volume in 15 hours. Also, in the food packaging test, no abnormality was found in the observation after 30 days as in Example 1.

[Comparative Example 1] All of the same as Example 1 except that PET / PE subjected to perforation treatment was laminated on water- and oil-resistant paper by dry lamination as a breathable layer, and PET was used on the side of the stored article. Then, a rectangular oxygen scavenger (long side 32 mm x short side 3) is formed on the strip-shaped separator layer (release paper).
0 mm) was adhered to obtain a roll of a label type oxygen absorber continuous body. Using this label-type oxygen scavenger, the oxygen scavenging performance test and the food packaging test were performed in the same manner as in Example 1. In the deoxidation performance test, all three bags were deoxidized to less than 0.1% by volume. However, in the food packaging test, rust was observed on the surface of the label type oxygen scavenger in 1 out of 5 bags.

[Comparative Example 2] As a breathable layer, a film obtained by laminating PET / PE which had not been subjected to perforation treatment on water- and oil-resistant paper by dry lamination was used except that PET was used on the side of the article to be stored. In the same manner as above, a rectangular oxygen scavenger (long side 32 mm) is placed on a strip-shaped separator layer (release paper).
A roll of a label type oxygen scavenger continuous body to which (short side 30 mm) was adhered was obtained. Using this label-type oxygen scavenger, the oxygen scavenging performance test and the food packaging test were performed in the same manner as in Example 1. In the oxygen scavenging performance test, all three bags were 10 after 15 hours of storage.
It was clear that oxygen was deoxidized only to ± 0.5% by volume, and that the deoxidation rate was slow.

As is clear from the above, the label-type oxygen scavenger of the present invention has an oxygen concentration of 0.
Deoxygenated to less than 1% by volume. This is (A) despite the polyether polyamide block copolymer constituting the waterproof moisture-permeable resin film layer does not have pores,
Due to its high moisture permeability, a sufficient amount of water can be quickly supplied to the sheet-shaped oxygen absorber, and (B) the microporous membrane has high air permeability, so oxygen can be supplied to the sheet-shaped oxygen absorber at a sufficient rate. Since it was supplied, it is considered that a quick deoxidizing action as a deoxidizer was obtained.

The label-type oxygen scavenger has a moisture permeable property (A) even though the polyether polyamide block copolymer resin layer constituting the waterproof and moisture permeable resin film layer has no pores. The rust bleeding was not visually recognized because of high water resistance and high water resistance.

[0061]

EFFECT OF THE INVENTION The label-type oxygen scavenger of the present invention has a sheet-shaped deoxidant by using a combination of (A) a resin film having both waterproofness and moisture permeability and (B) a microporous membrane in the breathable layer. The exudation of rust from the oxygen absorber mixed with the oxygen body is prevented.

Further, (A) since the waterproof and moisture-permeable resin film layer has a high moisture permeability, moisture evaporating from an object to be stored permeates the resin film and is rapidly supplied to the sheet-shaped deoxidizer, and (B) Since the oxygen permeability of the microporous membrane is high, oxygen in the atmosphere permeates the membrane and is quickly supplied to the sheet-shaped deoxidizer, thereby preventing the deoxidation rate from decreasing. The label-type oxygen scavenger of the present invention can be suitably applied to fast deoxygenation storage of foods containing a large amount of water.

[Brief description of drawings]

FIG. 1 is a sectional view of a label type oxygen absorber.

FIG. 2 is a cross-sectional view of a label type oxygen absorber with a clear adhesive layer.

[Explanation of symbols]

10 Breathable layer 20 Sheet-shaped oxygen absorber 30 base layer 40 Separator layer 31 Adhesive layer 32 Adhesive layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B32B 27/18 B32B 27/18 G B65D 81/26 B65D 81/26 R (72) Inventor Masateru Nagata Tokyo 2-5-2 Marunouchi, Chiyoda-ku Sanryo Gas Chemical Co., Ltd. (72) Inventor Takashin Ito 6-1-1 1-1 Shinjuku, Katsushika-ku, Tokyo Mitsubishi Gas Chemical Co., Ltd. F-term (reference) 3E067 AB99 BA15A BA15B BA15C BB06A BB06B BB06C BB14A BB14B BB14C BB24A BB24B BB24C BC04A BC04B BC04C CA03 CA07 CA10 EE21 EE25 GB13 GD01 BA00 AK02 AK02B04 CA02A02 BA01 4A02 BA01 BA02 BA02 BA02 BA02 BA02 BA02 BA02 BA04 BA07 BA19 BA02 BA02 BA04 BA07 BA19 BA10A BA10D BA10E CA09C CB05B DE01 DG15 DG15E DJ06E DJ10E EC01 EH17 EJ19 EJ37 GB90 JB16C JD02D JD03 JD04D JD05D JL13B JL14 E JM02E YY00D 4G066 AA02B AA36D AC13C AC22C AC26C BA02 BA03 BA05 BA20 BA36 BA38 CA37 DA03 EA07 FA01 FA20 FA27

Claims (5)

[Claims] 1. A base layer provided with an adhesive layer, a sheet-shaped oxygen absorber made of a deoxidizing resin obtained by mixing a thermoplastic resin with an oxygen absorber, and a breathable layer are laminated in this order, and a sheet-shaped oxygen absorber. In the label-type oxygen scavenger in which the base layer and the breathable layer are adhered to each other in the peripheral portion of (1), the breathable layer is (A) waterproof with a water pressure resistance of 2,000 mmH ₂ O or more and moisture permeability 1, label type oxygen scavenger characterized by comprising a combination of waterproof and permeable resin film (B) microporous membrane having both 000g / m ^2/24 hours or more breathable. 2. The label-type oxygen scavenger according to claim 1, wherein the waterproof and moisture-permeable resin film (A) constituting the breathable layer is a polyetheramide block copolymer. 3. The waterproof / moisture permeable resin film (A) constituting the breathable layer is a polyetheramide block copolymer having a linear saturated aliphatic polyamide chain and a polyoxyalkylene chain. The label-type oxygen scavenger according to claim 2. 4. The label-type oxygen scavenger according to claim 1, wherein the microporous membrane (B) constituting the breathable layer is made of a non-woven fabric. 5. A web of label-type oxygen scavengers, comprising a plurality of label-type oxygen scavengers according to claim 1 adhered to a strip-shaped separator layer by an adhesive layer of a base layer.