JPH01153458A - Fluid leakage preventing wrapping bag - Google Patents

Abstract

PURPOSE:To prevent leakage and penetration of fluid content from the article to be packaged and minimize occurrence of damage and contamination to other outside articles, by providing water-absorbent sheet along the inner face of a wrapping bag. CONSTITUTION:A water absorbent sheet 3 is disposed along the inside face of a wrapping bag 1 and obtained by impregnating or coating aqueous ethylenically unsaturated monomer into or onto fiberous or spongy substrate and then polymerizing the monomer to produce high molecular water absorbent composite material. The water absorbent sheet 3 is enclosed in a plurality of sectioned spaces which are formed between outer films 5, 6. At least one of the films 5 and 6 is made from water permeable material, preferably one of the films is water permeable while the other is water impermeable and these films are laminated on the absorbent sheet 3 to prevent a splash back of the water absorbent resin and fluid leakage to the outside. In this case, it is required that the water permeable film 5 be disposed on the inside of the sheet to enable the water absorbent sheet to absorb a fluid leaked from the article, and water impermeable film 6 be disposed on the outside to prevent the absorbed fluid from penetrating to the bag.

Description

BACKGROUND OF THE INVENTION Technical Field The present invention relates to packaging bags. More specifically, the present invention relates to a packaging bag provided with a water-absorbing sheet on the inner surface. It is preferable as a bag to prevent water leakage during transportation of potted plants, etc.).

Prior Art Conventionally, when transporting small amounts of liquid sample products in envelopes, paper bags, etc., the lids are sealed with vinyl tape or the entire bag is wrapped in a plastic bag to prevent liquid leakage. It is. However, if a glass bottle is easily damaged, the bottle may break due to impact, causing liquid leakage, contaminating other transported goods, and significantly reducing its commercial value.

[Summary of the invention]

Summary The present invention aims to provide a solution to the above problem,
This objective is achieved by having the water-absorbing sheet absorb the liquid material that has flowed out.

That is, the leak-proof packaging bag according to the present invention is characterized in that a water absorbent sheet is provided on the inner surface of the packaging bag.

Effects The leak-proof packaging bag according to the present invention can protect the packaged liquid product from damage due to impact caused by dropping, traffic accidents, etc.
The contents are absorbed and retained within the bag to prevent the contents from leaking or oozing or from contaminating other products due to the bag being torn.

[Detailed description of the invention]

Water-absorbing sheet The water-absorbing sheet forming the leak-proof packaging bag according to the present invention is as follows:
This product absorbs and retains the moisture that flows out from damaged liquid products to prevent other products from getting wet when the liquid product is damaged. One preferred specific example of such a water-absorbing sheet is one made of a water-absorbing polymer composite [described below (A)], and another preferred specific example is one in which at least one of the sheets is water-permeable. This is a sheet (hereinafter referred to as a packaged water-absorbing sheet) [described later (B)] in which a water-absorbing resin is sealed in a large number of divided bag-like spaces provided between two sheets. In addition, "composed of a water-absorbing polymer composite" refers to not only a component consisting only of a water-absorbing polymer composite, but also
This indicates that other materials may be included as long as the effects of the present invention are recognized. Further, this also applies to the water absorbent sheet in the form of sachets.

Typical examples of such other materials include water-permeable sheets and water-impermeable sheets.

Hereinafter, the present invention will be described in detail with reference to the drawings.

(A) Water-absorbing polymer composite Figure 2 shows a cross section of a leak-proof packaging bag according to the present invention in which a water-absorbing polymer composite is used as the water-absorbing sheet.

The water-absorbing polymer composite 3 forming the water-absorbing sheet in the leak-proof packaging bag according to the present invention is prepared by impregnating or coating a fibrous substrate or a sponge-like substrate with an ethylenically unsaturated monomer to form a water-absorbing polymer as an aqueous solution. It is obtained by polymerizing it.

(A-1) Fibrous substrate or sponge-like substrate The fibrous substrate to be impregnated with or coated with the ethylenically unsaturated monomer aqueous solution is, specifically, one formed by loosely forming fibers, such as a pad, carding, or air-laying. woven web, tissue paper, woven fabric such as cotton gauze, knitted fabric, or non-woven fabric. A "formed" fibrous substrate is defined as a web that is already in the form of a web, even though cutting, joining, shaping, etc. may be required to incorporate the fibrous substrate into an article. Forming operations refer to those that do not require further application.

It is generally preferred to use a fibrous substrate based on absorbent fibers such as wood pulp, rayon, cotton or other cellulosic fibers and/or polyester fibers. However, other types of fibers, such as polyethylene, polypropylene, polystyrene, polyamide, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polyurea, polyurethane, polyfluoroethylene The molded fibrous substrate may include fibers such as polycyanide, vinylidene polycyanide, and the like.

The spongy substrate used in the present invention is a polymeric foam such as polyvinyl acetal sponge, rubber sponge, polyethylene foam, polypropylene foam, or urethane foam, and has a continuous network porous structure. Any item is fine.

(A-2) Water-soluble ethylenically unsaturated monomer The water-soluble ethylenically unsaturated monomer to be impregnated or applied to the fibrous substrate or sponge-like substrate should be a water-soluble ethylenically unsaturated monomer that can be converted into a water-absorbing polymer and has good water absorption properties after polymerization and drying. Any material may be used as long as it provides performance.

Water-soluble monomers that provide such performance include carboxylic acids or (and) salts thereof, phosphoric acids or (and) as functional groups.
and) salts thereof, water-soluble ethylenically unsaturated monomers having groups derived from sulfonic acids or (and) salts thereof. Specific examples include (meth)acrylic acid or a salt thereof, vinylsulfonic acid or a salt thereof, vinylphosphonic acid or a salt thereof, and the like. Among these, (meth)acrylic acid or a salt thereof is particularly preferred. The resulting polymer may be a homopolymer or copolymer of these monomers, or a graft polymer to starch or cellulose.

Furthermore, it is also possible to add crosslinking agents and additives to these monomers to improve absorption performance. As a crosslinking agent, methylene bisacrylamide, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)
Water-soluble polyfunctional ethylenically unsaturated monomers such as acrylates, polyglycidyl ethers such as ethylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether, polyols such as glycerin and pentaerythritol, and polyamines such as ethylene diamine, etc. Water-soluble compounds having two or more functional groups that can react with functional groups such as acid, phosphoric acid, and sulfonic acid are preferably used.

An aqueous solution of such monomers may be applied to a fibrous or sponge-like substrate by any convenient means or manner as long as the monomers remain uniformly dispersed and polymerized on the fibrous substrate. be able to. One typical means for this purpose is to impregnate the fibrous substrate or the like with an aqueous monomer solution or to spray the monomer aqueous solution onto the fibrous substrate or the like.

In addition, if desired, the seven-mer aqueous solution may contain a small amount of a water-soluble organic solvent dissolved therein.

(A-3) Production of water-absorbing polymer composite The step of polymerizing monomers uniformly dispersed on such a fibrous substrate or sponge-like substrate may be any suitable step. A typical method for such a method is one based on the action of a water-soluble radical polymerization initiator, specifically, a radical polymerization initiator is added to an aqueous monomer solution, and then the radical polymerization initiator is added to a fibrous or sponge-like substrate. Alternatively, the radical polymerization initiator can be applied as a solution separate from the monomer to the fibrous substrate, etc. after the monomer aqueous solution has been applied, by spraying, etc., and the radical polymerization initiator can be decomposed on the fibrous substrate, etc. The radical polymerization initiator is applied to a fibrous substrate as a solution separate from the monomer, and the aqueous Hemotsummer solution is applied thereto uniformly by spraying, coating, etc. Another means of initiating polymerization is irradiation with high energy radiation.

The water-absorbing polymer composite thus obtained is usually dried by means such as hot air, microwaves, and infrared rays. If unreacted monomers, etc. remain in the composite, it is preferable to wash the composite with water or warm water prior to drying.

(B) Packed water-absorbent sheet Packed water-absorbent sheet, that is, water-absorbent resin is sealed in a number of compartmented bag-like spaces provided between two sheets, at least one of which is water permeable. A preferred monolithic example of the water-absorbent sheet is shown by reference numeral 4 in the attached FIG. 3.

In this figure, the sachet-shaped water absorbent sheet 4 is formed into a single sheet by dividing a large number of bag-like spaces 4-a into vertical and horizontal grooves 4-b. A water-permeable sheet 4-c and a water-impermeable sheet 4-d constituting the surface portion not in contact with kraft paper etc. are pasted together to form a groove 4-b, and the grooves 4-b, 4-b A bag-like space 4-a having a considerable space therebetween is formed, and a considerable amount of water-absorbing resin 4-e is sealed inside this bag-like space 4-a.

Note that the water-permeable sheet 4-c and the water-impermeable sheet 4-d can be attached by any method as long as it provides sufficient strength. For example, the sheets 4-c and h4-d may be attached by using an adhesive or by heat-sealing the sheets 4-c and h4-d.

(B-1) 1 of the water absorbent resin 4-e sealed in the water absorbent resin bag-shaped space 4-a
m and the shape are arbitrary. For example, copolymers of monomers and crosslinking agents, such as hydrolysates of starch-acrylonitrile graft polymers and hydrolysates of cellulose-acrylonitrile graft polymers, such as crosslinked polyacrylamide and its hydrolysates, crosslinked Sulfonated polyethylene, crosslinked poval, saponified crosslinked vinyl ester-unsaturated carboxylic acid copolymer described in JP-A-52-14689 and JP-A-52-27455, crosslinked polyacrylate and acrylic acid - Examples include acrylic ester copolymers, crosslinked isobutylene-maleic anhydride copolymers, and crosslinked polyethylene oxide. Further, polymers having self-crosslinking properties, such as self-crosslinking polyacrylic acid, the resin described in Japanese Patent Publication No. 54-30710, and polymers containing at least a hydroxyl group and a carboxylade group in the molecule, such as Japanese Patent Publication No. 54-30710, 37994
The resin described in No. In addition, it is a water-absorbing resin obtained by polymerizing starch or cellulose, a water-soluble monomer, (or) a monomer that becomes water-soluble by hydrolysis, and a crosslinking agent as essential components, and performing hydrolysis if necessary. There may be.

The above-mentioned water-absorbing resin may be used alone or in combination of two or more kinds, or may be a water-absorbing polymer composite as described above. Water absorption performance is 20-2000
g/g is preferable. Further, the shape of the water-absorbing resin 4-e is not particularly limited, and may be any of powder, particulate, flake, and fibrous shapes.

(B-2) Water-permeable sheet The water-permeable sheet 4-c used in the present invention may be, for example, a sufficiently fine nonwoven fabric made of a thermoplastic material, or a thermoplastic sheet that has been made water-impermeable and then electrified. Any suitable material can be used, such as one in which fine communication holes are provided by radiation irradiation or the like.

Note that this water-permeable sheet 4-c does not need to consist of only a single sheet; if the desired water-permeability can be obtained in the end, this water-permeable sheet 4-c may be further laminated with other water-permeable sheets. or other materials, such as reinforcement,
An adhesive material or the like may be provided on the entire surface or a portion of the sheet.

The portion exhibiting water permeability does not need to be the entire surface of the sheet, and may be only a portion of the sheet.

In addition, a sheet similar to this water permeable sheet 4-c is
It can be used as a water-permeable sheet 5 that is used as needed in a leak-proof packaging bag as shown in FIGS.

7f & Leak Prevention Packaging Bag The leak prevention packaging bag 1 according to the present invention is formed by providing a water absorbent sheet on the inner surface of the packaging bag. Here, the term "inner surface of the packaging bag" refers to the surface or portion that becomes the inside of the bag when the product is actually packaged.

Many conventional packaging bags are often manufactured by cutting a bag material, such as kraft paper, according to the bag's unfolding pattern, and then pasting them together. The leak-proof packaging bag according to the present invention is similar to a conventional packaging bag except that the inner surface is provided with a water-absorbing sheet, and therefore, it can be manufactured using the same bag material and method as the conventional packaging bag. It can be manufactured.

When manufacturing the packaging bag according to the present invention according to this method,
The water-absorbent sheet may be provided before the bag material is cut, after the bag material is cut, or after the bag is made, but from the standpoint of packaging efficiency, the water-absorbent sheet is It is preferable to set it up before bagging.

Packaging bags are generally made from water-permeable bag material. When using such a bag material in the present invention,
It is preferable to provide a water-impermeable sheet, preferably between the water-absorbent sheet and the bag material.

It should be noted that the water-absorbing sheet does not need to be provided on the entire inner surface of the packaging bag or on all the portions that will become the inner surface when the bag is made; if the intended purpose of the present invention is to be achieved, it is not necessary to provide the water-absorbing sheet on the entire inner surface of the packaging bag. There may be.

As mentioned above, the water-absorbing sheet used in the present invention may be a laminated sheet or a sheet made of other purpose-oriented sheets, materials, and Rui 1 as long as the effects of the present invention are achieved. That's right. Specific examples of such auxiliary sheets and materials include, for example, a water-permeable sheet 5, a water-impermeable sheet 6, and the like. Such a water-permeable sheet or water-impermeable sheet is preferably laminated on the water-absorbent sheet in order to prevent the water-absorbent resin from scattering and to prevent liquid from leaking to the outside of the packaging bag. In this case, the water-permeable sheet must be installed on the side of the water-absorbent sheet that comes into contact with the product so that the water-absorbent sheet can absorb liquid leaked from the packaged product. In order to prevent the liquid absorbed by the absorbent sheet from penetrating the bag material, it is necessary to provide it on the bag material side of the water absorbent sheet.

The bag material, water absorbent sheet, and auxiliary sheet used as needed can be attached by any method as long as it does not substantially impede the water absorbency; for example, adhesive may be used. Gataki

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a specific example of a leak-proof packaging bag according to the present invention. Figures 2 and 3 show a cross section of a packaging bag in a preferred embodiment of the leak-proof packaging bag according to the present invention. FIG. 3 shows the case where a sachet-shaped water absorbent sheet is used. 1...Leakage prevention packaging bag, 2...Kraft paper, 3.
...Water absorbent polymer 1 summer union, 4...Water absorbent sheet in sachet form, 4-a...Bag-shaped space, 4-b...Groove, 4-
c...Water permeable sheet, 4-d...Water impermeable sheet,
4-e...Water absorbent resin, 5...Water permeable sheet, 6.
...Water-impermeable sheet. Applicant's agent Mr. Sato

Claims (1)

[Claims] 1. A leak-proof packaging bag, characterized in that a water absorbent sheet is provided on the inner surface of the packaging bag. 2. The water-absorbing sheet is a water-absorbing polymer composite obtained by impregnating or coating a fibrous substrate or sponge-like substrate with a water-soluble ethylenically unsaturated monomer and then polymerizing the water-soluble ethylenically unsaturated monomer. A leak-proof packaging bag according to claim 1, which comprises: 3. Claim 1, wherein the water-absorbing sheet is one in which a water-absorbing resin is encapsulated in a number of divided bag-like spaces provided between two sheets, at least one of which is water permeable. Leak-proof packaging bag. 4. Claim 3, wherein the water-absorbing resin is obtained by polymerizing a water-soluble ethylenically unsaturated monomer.
Leak-proof packaging bag.