JPH0212827B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a packaging bag, and more specifically, its main function is to absorb and retain excess water that separates from the contents, and to gradually release the absorbed moisture in the form of steam to dry the contents. The present invention relates to a packaging bag that has the effect of adjusting the moisture content of the contents so as to prevent overflow. BACKGROUND ART Conventionally, as a method of packaging foods, filling food into bags made of synthetic resin such as polyethylene has been widely used as a simple and inexpensive method. However, foods containing a lot of water and whose water content releases over time, such as fish meat, fish eggs, meat, etc., or mushrooms in cut mochi, frozen foods, or fresh foods. When foods such as green vegetables, leafy vegetables, etc. are packed in bags made of synthetic resin such as polyethylene, the moisture that escapes stays at the bottom of the bag, resulting in parts of the food becoming extremely watery. As a result, it has always been a problem that it has various negative effects such as poor appearance, significant loss of taste, and undesirable hygiene, and a significant reduction in the value of the product. As a countermeasure to this problem, methods such as occasionally manually discarding the separated water that has accumulated in the bag, or using a bag with small holes partially cut in the bottom of the bag have been taken. The former method requires a great deal of time and effort, and the latter method requires that the area where the bag is placed be contaminated with water as the released moisture leaks out through the holes in the bag. In addition, if the bags are accumulated in a cardboard box, etc., the leaked moisture may cause the cardboard to absorb water, weakening the cardboard, making it more likely to break, and causing secondary problems such as the food contents. This creates new hygiene problems such as the risk of contamination from the outside through the holes in the bag, and neither method is a fundamental solution for packaging foods that contain a large amount of moisture. The current situation is that it is not blooming. The present invention relates to a packaging bag completed as a means for solving the above-mentioned problems. The present invention will be explained in detail below. In order to solve the above-mentioned problems, the inner surface of the packaging bag should immediately absorb the moisture released from the food contents, and retain the moisture at room temperature and normal pressure, or under normal conditions close to it. It is essential to provide a layer that does not easily release even when subjected to pressure, vibration, impact, etc. In order to achieve such a function, the present inventors conducted various studies and found that water-insoluble water-absorbing and water-retaining resin powder (hereinafter abbreviated as water-absorbing resin), which is a partially cross-linked water-soluble resin, absorbs water. absorb well,
The porous inorganic powder absorbs and retains water in its pores without changing its volume, and all of them are able to withstand slight pressure, vibration,
Focusing on the fact that the retained moisture will not be released in liquid form even when an impact is applied, these water-absorbing resins or a mixture of them and porous inorganic powder are layered on top of a heat-adhesive film. The present invention has been completed as a bag-shaped packaging bag using a laminate having a structure in which a water permeable layer is provided on top of the laminate. Hereinafter, the present invention will be specifically explained using the drawings. The moisture-adjusting packaging bag of the present invention, as shown in FIG. This is a moisture-adjusting packaging bag made by heat-sealing three or four sides using a laminate having a water-permeable breathable layer 3 on top, leaving a heat-sealed portion. The heat-fusible film 1 may be a film mainly made of polyethylene, unstretched polypropylene, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, etc., or a film made of these alone. A laminate of a film of polyester, oriented polypropylene, nylon, or the like is used, but is not particularly limited. In addition, it is sufficient that the film has a thickness similar to that used for ordinary food packaging bags, and is usually 30 mm thick.
A film with a thickness of ~100μ is used,
It is not particularly limited. The water-absorbing resin layer 2 is mainly made of a water-absorbing resin made water-insoluble by partially crosslinking a water-soluble resin, or a mixture of the water-absorbing resin and a porous inorganic powder. As the water-absorbing resin, starch-sodium acrylate graft copolymer, starch-acrylonitrile graft copolymer hydrolyzate, partially cross-linked starch-poly(meth)acrylic acid copolymer, partially cross-linked starch-poly(meth)acrylic acid copolymer, Starch graft copolymer-based products such as starch-polymethyl methacrylate hydrolyzate and salts of the above substances, or cross-linked synthetic resin-based products such as methyl methacrylate-vinyl acetate copolymer hydrolyzate, etc. can be given. Further, the porous inorganic powder is an inorganic powder having pores or a petal-like special shape, and powders such as zeolite, perlite, calcium silicate, etc. can be used. These water-absorbing resins and porous inorganic powders are applied as a coating liquid mixed with a resin liquid using alcohols, acetic esters, ketones, or hydrocarbons as a solvent, or a resin binder consisting of a hot melt of a thermoplastic resin. , form a layer. As a binder resin, it has low solubility in water,
Preferably, the water-absorbing resin has a flexibility that does not hinder the volume increase when it absorbs water and swells, such as chlorinated polyolefin, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polyamide resin, Examples include cyclized rubber, chlorinated rubber, linear thermoplastic polyester resin, urethane resin, etc., but are not particularly limited. The particle size of water-absorbing resin or porous inorganic powder is
Less than 35 meshes, preferably less than 100 meshes
A value of 5μ or more is good, and a shape close to a spherical shape is good. The actual application of the water absorbent resin layer 2 is to mix at least 20 parts by weight, preferably 50 parts by weight or more of a water absorbent resin alone or a mixture with porous inorganic powder with 100 parts by weight of the binder resin, and heat it as a coating solution. It is coated on the meltable film 1 by a gravure method, a silk screen method, etc., and is dried or hardened to form a film. The shape of the film must be such that a heat-sealed portion remains so as not to impair its suitability for heat-sealing during the subsequent bag-making process. In addition, the amount of water-absorbing resin layer 2 applied varies depending on the type of food that is the content of the packaging bag, so the amount of water released varies.
It is preferable to set a coating amount suitable for each type of food, and there is no particular limitation. Furthermore, the water-permeable layer 3 retains the water-absorbing resin layer that absorbs and retains water, and prevents the water-absorbing and swollen water-absorbing resin from coming into contact with and adhering to the food contents, thereby impairing the taste of the food. The pores are provided in order to prevent liquid moisture from flowing into the water-absorbent resin layer, and conversely, to guide water vapor that is gradually released from the water-absorbent resin layer that has absorbed and retained water into the bag. It must have an infinite number of
For example, paper, nonwoven fabric, cloth, etc., a synthetic resin film with pores formed on its entire surface, a synthetic resin film filled with an extender pigment and made finely porous by stretching or the like may be used. Similarly to the shape of the film of the water-absorbing resin layer 2, the water-permeable and breathable layer 3 is also made of water-absorbing resin so as to leave a heat-sealed portion in order not to impair its suitability for heat-sealing during the subsequent bag-making process. It is necessary to provide it in a shape that covers only layer 2. As a method for bonding the water-absorbing resin layer 2 and the water-permeable breathable layer 3, it is preferable to bond them partially so as not to prevent the water-absorbing resin layer 2 from absorbing water and increasing its volume due to swelling. Adhesives used in conventional lamination processes are used. In order to make the laminate configured as described above into a bag shape, the portion where the water-absorbing resin layer 2 and the water-permeable layer 3 are not provided, that is, the heat-fusible film 1 is exposed to the surface. Bags are made by heat-sealing the parts. Next, a method of using the packaging bag of the present invention will be specifically explained. The packaging bag of the present invention is effective as a bag for packaging foods containing a large amount of moisture. In other words, fillets of fish such as tuna, bonito, and yellowtail, fish roe such as kazunoko, salmon roe, and cod roe, mushrooms in fresh foods, leafy vegetables, and other frozen foods that are being thawed can take a long time. Although moisture tends to be released over time, by packaging these foods with the packaging bag of the present invention, the released moisture is immediately absorbed and retained in the water-absorbing resin layer 2 through the water-permeable layer. Therefore, the food will not become watery, and the appearance and taste of the food will not be affected.
It is also hygienic. In addition, the water once absorbed and retained in the water-absorbent resin layer 2 is exposed to a slight pressure, vibration,
Even if an impact is applied, it will not be released in liquid form, so there is no need to worry about water flowing back during transportation.
Furthermore, since the water absorbed and retained in the water-absorbing resin layer 2 is gradually dissipated in the form of water vapor, it is effective in preventing deterioration of appearance and taste due to drying of the surface of the food contents. be. In addition, since the packaging bag of the present invention uses the heat-fusible film 1 as a base material, it can be heat-sealed on all four sides to be completely sealed, or it can be heat-sealed on three sides to be semi-sealed as promised. Both are possible. As described in detail above, the packaging bag of the present invention is a method for packaging high-moisture-containing foods that are moisture-absorbing, and which has traditionally been extremely difficult to package without deteriorating their appearance or taste. It is effective as a food product and has great utility value in the distribution of these foods. Examples of the present invention will be described below. <Example> Starch graft copolymer water absorbent resin fine powder (Sunwet IM300MPS, manufactured by Sanyo Chemical Industries, Ltd.) and petal-shaped calcium silicate fine powder were added to the polyethylene side of a laminated base material consisting of 12μ polyethylene terephthalate film and 40μ medium density polyethylene film. (Fluorite R, manufactured by Tokuyama Soda), chlorinated polypropylene resin binder (Super Chron 803MW,
Sanyo Kokusaku Pulp) with a solid content weight ratio of 100/400/
The total coating amount of the coating liquid mixed in the ratio of 300
The water-absorbing resin and calcium silicate were coated at a coating weight of 5.6 g/m ² , 2.8 g/m ² and 2.1 g/m ² , respectively, and the solvent was removed to form a film.
However, the shape of the film is 10 cm x 15 cm.
cm rectangle, and the spacing between adjacent patterns is 3
It was made into a continuous pattern of cm. Furthermore, 60 pieces of unsized processed base paper were coated on top of this film (in other words, in a rectangular shape of 10 cm x 15 cm) to cover only the film pattern.
g/m ² (manufactured by Nagoya Pulp) were bonded together using a urethane adhesive applied in a grid pattern. Using this laminate, parts other than the water-absorbing resin film pattern,
That is, a packaging bag of the present invention having dimensions of 13 cm x 18 cm was obtained by heat-sealing the portion where the polyethylene was exposed on the surface. In addition, a packaging bag having dimensions of 13 cm x 18 cm made of only 12 μm polyethylene terephthalate film/medium density polyethylene film was produced in the same manner as a comparative example. Fill each of these two types of packaging bags with 200g of tuna fillets and place them in a refrigerator at an internal temperature of 10℃.
Table 1 shows the results of observing the condition of each fillet after being stored for days and comparing the taste when eaten as sashimi.

[Table] 〓× Inferior

[Table] 〓× Inferior The packaging bag according to the present invention weighs approximately 3.5g after use.
Of course, the packaging bag of the comparative example did not absorb any moisture. As shown in the results, it was confirmed that the packaging bag according to the present invention can be used without impairing the appearance or taste of tuna fillets.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the packaging bag of the present invention. DESCRIPTION OF SYMBOLS 1...Film having heat-fusible properties, 2...Water-absorbing resin layer, 3...Water-permeable breathable layer, 4...Contents.

Claims (1)

[Claims] 1 A water-absorbent resin layer containing a binder is provided in a pattern on one side of a film having heat-sealing properties, leaving a heat-sealed portion, and a heat-sealed portion is similarly placed on top of the water-absorbent resin layer. This moisture-adjusting packaging bag is made by heat-sealing three or four sides of a laminate that is partially adhered and provided with a water-permeable and air-permeable layer.