JPH031934A - Packaging material for deoxidizer - Google Patents

Abstract

PURPOSE:To enhance resistance to water and oil and to exercise stabilized deoxidizing performance by using a specified water emulsion bonding agent and laminate processing of a film. CONSTITUTION:A packaging material for a deoxidizer constituted by a pored plastic film A and a plastic film or a water and oil resistance processed paper B which has pores and is a non-woven cloth or a micro-pored film sticking together, and a bonded layer C composed of a water emulsion bonding agent composed of emulsion of crosslinking acryl resin, hydrophobic polyester resin, alkyd resin, polyamide resin, polyurethane resin, epoxy resin, melamine resin or phenol resin is provided between A and B and on the surface of B. At that time, peameability of the permeable film B can be varied by adjusting the coating volume of the water emulsion bonding agent to make Gurley permeabil ity in the range of 1 - 10,000 sec./100 ml.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides an oxygen scavenger package consisting of an air-permeable multilayer film laminated using a specific water emulsion adhesive for the adhesive layer of the laminated film. It's about the body. More specifically, it is easy to manufacture packaging materials for oxygen absorbers and form bags;
In addition, the present invention provides an oxygen absorber package that not only has stable air permeability, seal strength, and lamination strength, but also has excellent durability such as water resistance and oil resistance, and thus exhibits stable oxygen scavenging performance.

[Conventional technology]

Oxygen scavengers are composed of compositions that have the property of absorbing oxygen, and are usually used by being enclosed in air-permeable sachets.

In general, the packaging materials that make up breathable sachets include, for example:
Packaging materials made of a laminate of paper and perforated polyethylene film, packaging materials made of a laminated adhesive of perforated plastic film, paper and perforated polyethylene film, and packaging materials using nonwoven fabrics, microporous membranes, etc., are used.

However, there is a problem with oxygen absorber storage technology for oxygen absorber packaging materials, as oxygen absorbers are used in various foods such as dry foods, high moisture foods, acidic foods, oil-processed foods, and alcohol-containing foods. The moisture contained in the oxygen scavenger composition transfers to the dry food, degrading its oxygen scavenging performance, and the moisture in high-moisture foods transfers to the oxygen scavenger composition, causing stains on the surface of the packaging material. The appearance of the food may become dull, oil from the food may seep into the packaging material, the air permeability of the packaging material may be compromised, and the oxygen absorbing performance may be compromised. Due to these drawbacks, the material composition of the packaging material has been changed depending on the situation in which the oxygen absorber is used, but it is not a perfect packaging material for oxygen absorbers.

In addition, for film laminates, low B
It is common practice to heat-laminate a sealant film with adhesive /J, but if this method is adopted in the present invention, the low-melting point film will be
Al1 and perforated plastic laminated film (A),
The small-diameter pores may become clogged, resulting in a decrease in air permeability, and it is difficult to provide stable air permeability.

Furthermore, if low temperature lamination conditions are used to ensure air permeability, sufficient lamination strength cannot be obtained.

In other words, it is difficult to laminate a laminate film with a small bloom diameter, which is a feature of the present invention, by conventional thermal lamination.

With conventional thermal lamination processing, it is possible to process laminate films with large opening diameters, but in that case, tF
It is not suitable for use due to its water-repellent and oil-based properties, and the printing on the packaging material is damaged due to large holes, making it difficult to maintain its aesthetic appearance.

On the other hand, oxygen absorbers using laminated films with small opening diameters are commercially available, but in this case, a three-layer film similar to the present invention is perforated with a hot needle, and then a low melting point sealant film is extruded and laminated. Furthermore, holes are made with a hot needle. However, there remain problems such as poor air permeability of the air permeable film, unstable air permeability, and poor workability when processing packaging materials, which limits its range of use.

[Problem to be solved by the invention]

The present invention not only is easy to manufacture and form bags, and has stable air permeability, seal strength, and lamination strength, but also
The purpose of the present invention is to provide a packaging material for an oxygen absorber that has excellent durability such as water resistance and oil resistance, and exhibits stable oxygen scavenging performance.

[Means to solve the problem]

The present invention consists of a perforated plastic film (A), a plastic film that is a nonwoven fabric or a microporous membrane that has micropores and does not allow water to pass through under normal pressure, or a water- and oil-resistant treated paper (B).
In the packaging material for an oxygen absorber made by laminating (A)
and (B) and on the surface of (B), a water emulsion □ digon adhesive made of an emulsion of crosslinkable acrylic resin, hydrophobic polyester resin, alkyd resin, polyamide resin, polyurethane resin, epoxy resin, melamine resin, or phenol resin. This is a packaging material for deoxidizing, which is characterized by having a Gurley air permeability of 1 to 10.000 seconds/100 d and having an adhesive layer formed thereon.

The present invention will be explained in detail below.

(1) Perforated plastic film (A) As the perforated plastic film (A) of the present invention, for example, polyethylene terephthalate, nylon, polypropylene film, etc. are used. Further, the plastic film (A) may be a 16-layer film having two or more layers, and the -th layer is usually a film having a softening point higher than other layers by 10°C or more. .

In this case, the -th layer is polyethylene terephthalate, nylon, polypropylene, etc., and the other layers are LLDP
E, polypropylene, nylon, etc. As other layers, sealant films with good low-temperature heat sealability such as LDPE, EVA copolymer ionomer films, etc. are not suitable.

Lamination of films can be produced by fusing, adhesion, pressure bonding, dry lamination, extrusion lamination, or the like.

Further, the thickness of the film is 10 to 2008 m1, preferably 12 to 50 μm, and the pore diameter of the film is 10 to 500 μm.
m, preferably 50 to 250 am.

If the pore size of the film is less than 10 μm, the air permeability will decrease;
00 // m or more is undesirable because liquids such as water, oil, acid, and alcohol are likely to enter from the outside, resulting in poor durability.

On the other hand, if the thickness of the film is less than 10 μm, it is too thin and not only difficult to process, but also has poor durability, and if it is more than 500 μm, the flexibility of the film is undesirable.

(2) Non-woven fabric A non-woven fabric made of polyolefin, polyester, etc., and has a Gurley air permeability of usually about 0.01-1000 seconds/
loOmffi, which does not allow water to pass through at normal pressure. For example, Tyvek (manufactured by DuPont) and Luxar (manufactured by Asahi Kasei Industries) are known.

(3) Microporous membrane has micropores, the pore size is 0.01 to 50 μm, and the Gurley air permeability is usually about 0.01 to i, ooo seconds/10
It has a zero reduction and does not allow water to pass through at normal pressure. Microporous membranes are manufactured by stretching a synthetic resin film such as polyethylene or polypropylene. It is manufactured by methods such as extraction of fine powder or stretching.

For example, NF Receipt (manufactured by Tokuyama Soda ■), Cellbore (manufactured by Blockchain Chemical Industry ■), FP-2 (manufactured by Asahi Kasei Industries ■), NO.
P (manufactured by Nippon Petrochemical Co., Ltd.), Nidoflon NTF (manufactured by Nitto Electric Industry Co., Ltd.), Polymer L1 Paper (manufactured by Daikin Industries, Ltd.), Duraguard (manufactured by Celanese Co., Ltd.), Boertex (manufactured by Boa Co., Ltd.), etc. are known. There is.

(4) Water- and oil-resistant treated paper This is generally referred to as oil-proof paper, wet-proof paper, wet-proof paper, water-resistant and water-repellent paper, etc.

Specifically, coated printing paper (art paper, coated paper, gravure paper, etc.), information recording paper, electrical insulation paper, release paper, release paper, corrugated paper, folding carton paperboard, base paper for decorative laminates, processed food packaging. Among various papers such as paper and carton paper for food packaging, those belonging to processed paper for food packaging and mixed paper of paper and plastic are suitable. In addition, processed paper includes acid-treated chemically treated paper such as parchment paper, WS paper, MC paper,
Filter paper, glassine paper, WO2 paper, etc., which contain synthetic resin during the papermaking process, and coated paper (wax paper,
Fluorine-processed paper, vinylidene chloride-processed paper, PVC-processed paper,
(PE processed paper, lacquer coated paper, etc.), laminated paper, and other papers that undergo physical processing after papermaking.

Processed paper suitable for the present invention has a basis weight of 10 to 100 g/m2
It is preferably cardboard with a weight of 20 to 60 g/rrf and has been treated with water and oil resistance by the method described above.

If the basis weight is too small, it will lack workability and durability, and if it is too large, the packaging material will be stiff and difficult to fill with an oxygen scavenger.

(5) Water emulsion adhesive Water emulsion adhesive is a water-based synthetic resin emulsion in which fine resin particles are dispersed in water as colloidal particles or coarser particles to form an emulsion, and are used as adhesives. For example, polyvinyl acetate, copolymers of vinyl acetate and ethylene, vinyl laurate, maleic acid long chain ester acrylic ester, polyacrylic acid, polymethacrylic acid, acrylic acid and acrylic acid alkyl ester, MMA, AN, etc. Copolymer of acrylic acid, methacrylic acid, unsaturated carboxylic acid polymer N
- Methylol acrylamide copolymer, polyvinyl chloride, vinyl chloride-vinylidene chloride copolymer, polyamide, butyral resin, alkyd resin, phenol resin, melamine resin, glyoxazar resin, epoxy resin, polyester resin, polyurethane resin, There are emulsions of natural rubber and synthetic rubber such as butadiene-acrylonitrile copolymer.

However, general water emulsion adhesives such as polyvinyl acetate emulsions are inferior in creep resistance, water resistance, chemical resistance, adhesion to hydrophobic materials, etc., and cannot be used for this purpose.

The water emulsion adhesive used in the present invention is a crosslinkable emulsion, thermosetting resin condensate, thermoplastic polymer, etc. that have been introduced with unsaturated carboxylic acid groups to improve adhesion to hydrophobic materials. It is a resin emulsion with improved water resistance and chemical resistance.

Furthermore, the coated surface must be tack-free after coating and drying.

Specifically, acrylic acid alkyl ester, MMASA
Crosslinkable acrylic resins, polyester resins, alkyd resins, polyamide resins, in which functional groups such as unsaturated carboxylic acids such as acrylic acid and methacrylic acid, N-methylol acrylamide, acrylamide, and glycidyl methacrylate are introduced into N, etc. as a copolymer component; It is a resin emulsion made of polyurethane resin, epoxy resin, melamine resin or phenol resin.

Among these, particularly desirable are hydrophobic polyester resins, polyurethane resins, epoxy resins, and crosslinkable acrylic resin emulsions.

In addition, in water emulsion adhesives, when water is lost during the coating and drying process, the In wood particles fuse with each other and adhere to the adherend, forming a densest arrangement, which reduces the air permeability of the film (B). However, by reducing the amount of water emulsion adhesive applied, the air permeability of the film (B) can be ensured.

Due to the adhesive strength of the film, water emulsion adhesives should be applied at a solids content of 1 g/g in each application area.
~15g/a, preferably 3-12g/a. The specific application amount is automatically determined based on the correlation between Gurley air permeability and adhesive strength.

(6) Film lamination processing method A water emulsion adhesive is applied to the air-permeable film (B), and after drying, it is bonded to the perforated brass tink film (A) by heat lamination. In addition, the water emulsion adhesive is ultimately applied to both sides of the air-permeable film (B), but depending on the processing process, the application may be done on both sides simultaneously or twice before and after the lamination process. will be implemented.

At this time, the air permeability of the film (B) having air permeability can be changed by adjusting the amount of water emulsion adhesive applied. Air permeability decreases in inverse proportion to the amount applied. However, if the coating amount is extremely small, the strength of the laminate between the perforated plastic film (A) and the air permeable film (B) will decrease, and the packaging will deteriorate during bag making when filling with the oxygen scavenger composition. The heat sealing strength of the material was observed to be reduced, making it unsuitable for practical use.

〔Example〕

Example 1 WOP paper (140 g/nf) & Hydrophobic polyester emulginon adhesive manufactured by Toyobo Co., Ltd.) was applied to one side with a solid content of 10 g/nf, dried, and the coated surface was tacked. Free. Next, a hole P with a pore diameter of 100 μm
A laminated film was prepared by laminating an ET film (a 12 μm thick film with holes in a 2×2+1/11 grid pattern) and the adhesive-coated surface of WO2 paper at 100 to 120° C.

A hydrophobic polyester emulsion adhesive (manufactured by Toyobo Co., Ltd.) was applied again to the WO2 side of this laminated film at a coating amount of 10 g/nf solids and dried to obtain a tack-free film.

Example 2 Instead of the WO2 paper used in Example 1, membrane JIJ
A laminated laminate film was prepared in the same manner as in Example 1, except that a 120 um cell bore (microporous membrane manufactured by Block Chemical Industry Co., Ltd.) was used.

Example 3 Instead of the perforated PET film used in Example 1, a perforated (PET/NY) film (2
A laminated/layered film was prepared in the same manner as in Example 1, except that a 42 μm thick film with X2QI11 lattice-shaped holes was used.

Example 4 In Example 1, the adhesive was acrylic emulsion (manufactured by Kanebo NSC) and the WO2 paper was Taihekuku 1059.
A laminated film was prepared in the same manner as in Example 1, except that the nonwoven fabric (manufactured by DuPont) was used.

Comparative Example 1 Completely the same as Example 1, except that the amount of the Toyobo Refined Water-based Polyester Emulsion Adhesive was changed to 25 g/11f solids on both sides of WO2 paper. A laminated film was created using the following method.

Comparative Examples 2 to 6 In Example 1, laminate films were created in exactly the same manner as in Example I, except for the following changes (1) to (5).

(1) The pore diameter of porous PET is set to 1 threshold (2.5X 2.5
m/12 μm thick film with holes in the lattice shell) (
Comparative Example 2) (2) The amount of hydrophobic polyester emulsion adhesive applied was 5 g/m2 (solid content) on both sides of WO1 paper.
Comparative Example 3) (3) Basis weight of WO2 paper 170g/m2 (Comparative Example 4) (
4) Japanese paper (tsubo! 40g/m2) (Comparative Example 5) The hydrophobic polyester emulsion adhesive used for lamination was replaced with vinyl acetate emulsion adhesive (¥ cloth 1: solid on both sides of WOP paper). 25 each in minutes
g/I) (Comparative Example 6) Comparative Example 7 Perforated (PET/PE) film with a pore diameter of 1100I (2X
52 μm thick film with 2 m/m grid-like holes)
and rayon 1fL (basis weight 40 g/m2) wo95
The unlaminated surface of the rayon paper was laminated at ~105°C, and the perforated PE film (1,
4X 1.4 m/m grid-like holes with a thickness of 30 μm
A laminated film was made by thermally laminating the film) at 90-100°C.

In addition, the above 50 x 50m+m packaging material has an oxygen absorption capacity of 50 (Jal's deoxidizing lFr
The oxygen absorber package filled with 1 composition and 500 m1 of air were placed in a bag made of oxygen barrier packaging material (ON/Pg), sealed, and left at 25°C to determine the time for the oxygen concentration to reach zero. It was measured.

The number of samples was 10 for each example. The results are shown in the table below.

〔Effect of the invention〕

As shown in the examples, by laminating a film with a specific water emulsion adhesive, a package with excellent performance as an oxygen scavenger can be obtained.

In addition, the role of water emulsion adhesives is not only to serve as an adhesive layer for laminated films or a heat sealing layer for packaging materials when filled with oxygen absorbing compositions, but also to control the air permeability of oxygen absorbing packaging materials. This is a point that can be changed to . The air permeability of the packaging material is determined by the air permeability of the water emulsion adhesive particles attached to the air permeable film (B).
The particles are uniformly dispersed and retained because gas can freely move in and out between the particles. The adhesive layer is preferably a monomolecular film, but
In order to maintain lamination strength and heat seal strength, it is practically applied in multiple layers rather than in a single layer.

When the water emulsion adhesive of the present invention is used as an adhesive layer during bag making, the adhesion between the air permeable film and the water emulsion adhesive is good, and the hot peeling between the layers that occurs with a low melting point sealant film can be avoided. Since it is not packed, it shows better heat sealing strength compared to packaging materials using conventional low melting point sealant films.

[Brief explanation of the drawing]

The drawing shows a cross-sectional view of a packaging material that is an embodiment of the invention. A: Perforated plastic film B: Non-woven fabric, microporous membrane or water/oil resistant pressurized paper C: Water emulsion adhesive

Claims (3)

[Claims] (1) Oxygen scavenger made by laminating a perforated plastic film (A), a plastic film that is a nonwoven fabric or microporous membrane that has micropores and does not allow water to pass through under normal pressure, or water- and oil-resistant treated paper (B) (A) and (
Between B) and on the surface of (B), a crosslinkable acrylic resin,
A water emulsion adhesive consisting of an emulsion of hydrophobic polyester resin, alkyd resin, polyamide resin, polyurethane resin, epoxy resin, melamine resin or phenol resin is provided as an adhesive layer, and the Gurley air permeability is 1.
A packaging material for an oxygen absorber, characterized in that the oxygen absorbing rate is ~10.000 seconds/100ml. (2) The amount of water emulsion adhesive applied between (A) and (B) and on the surface of (B) is 1 to 1 in terms of solid content, respectively.
The oxygen absorber packaging material according to claim (1), characterized in that the oxygen absorber packaging material has an oxygen absorbency of 15 g/m^2. (3) The pore diameter of the perforated plastic film (A) is 10~
The oxygen absorber packaging material according to claim 1, wherein the oxygen absorber packaging material has a diameter of 500 μm.