JPH02303825A - Water absorbing sheet having functionality - Google Patents

Abstract

PURPOSE:To keep the freshness of perishable foods by holding a mixture consisting of a highly water-absorbable polymer material and a specific functional material between specific packing materials to integrate all of them and further packing the whole in a specific packing form. CONSTITUTION:After a mixture 3 containing a highly water-absorbable polymer material and a specific functional material is held between inner layers 1, 2 to be integrated with said layers, an outer layer 5 wider than the held body thus constituted is folded so as to form side parts and an outer layer 4 is subsequently applied to the outer layer 5 from above and the side parts and end parts are heat-sealed to form a packing body constituted of the outer layers 4, 5 as a whole. As the specific functional material of the mixture 3 constituted of the highly water-absorbable material and the specific functional material, a substance having appropriate functionality such as an antibacterial agent, a deodorant or an ethylene gas absorbent or a composition having appropriate composite functionality due to a combination of them is used.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a functional water-absorbing sheet, and more specifically to a freshness-preserving material for fresh foods, sanitary products,
The present invention relates to a water-absorbing sheet that has specific functions and is useful as a material for products that require high water absorption, such as diapers, disposable rags, and paper towels.

[Conventional technology]

BACKGROUND ART Conventionally, superabsorbent resins have been widely used as materials for preserving the freshness of fresh foods, sanitary products, diapers, disposable rags, paper towels, and the like.

Conventionally, various measures have been taken to maintain the freshness of fresh foods, but in particular, free water exuding from fresh foods such as meat, fish and shellfish can significantly reduce the freshness of the foods concerned. Therefore, immediate removal of free water is an important factor indispensable for maintaining freshness.

Conventionally, as a countermeasure against this free water, a method is known as a prior art in which a water absorbent sheet using a super absorbent polymer material is housed in the packaging form of fresh food to absorb and remove the free water.

In addition, freshness of fruits and vegetables decreases due to ethylene gas generated from the fruits and vegetables and condensation of water vapor due to respiration when they are packed in boxes, bags, etc. in closed or nearly sealed conditions.

In order to prevent such deterioration in the freshness of fruits and vegetables, conventionally, two types of freshness-preserving materials, for example, a water-absorbing sheet made of super absorbent resin and an ethylene gas adsorbent, have been used to transport fruits and vegetables in boxes or bags. There are known ways to store it.

Water-absorbent sheet products used for various other purposes include, for example, those with a structure in which super-absorbent resin powder is sandwiched between two water-permeable sheet base materials, and those with super-absorbent resin powder on the sheet base material surface. Various forms are known, such as those in which a patterned water absorption layer is provided using a coating agent containing a resin, and an i-adhesive layer is formed in the non-patterned area and other sheet base materials are laminated. ing.

[Problem to be solved by the invention]

However, in the case of the above-mentioned conventional technology, when packaging fruits and vegetables, for example, two types of materials, a water absorbent sheet and an ethylene gas adsorbent, must be individually housed in the packaging form, and a large amount of fresh food is required. In the case of packaging, there are various problems such as extra effort, a decrease in overall work efficiency, and an increase in costs.

Furthermore, during transportation, the sachet containing the ethylene gas adsorbent may break and the ethylene gas adsorbent inside may adhere to the surface of the fruits and vegetables, worsening the appearance of the product, or the chemical components of the ethylene gas adsorbent may damage the food. There was a risk of contamination.

Packaging bodies for ordinary fresh foods use ordinary packaging materials, and the packaging materials themselves do not have specific functions such as antibacterial properties, so they are susceptible to contamination by food spoiling bacteria. It is impossible to reliably prevent the deterioration of freshness of fresh foods caused by water-absorbing sheets alone, and it has been desired to establish an effective measure.

In addition, animal foods such as meat and fish and shellfish are generally stored and distributed under refrigerated conditions, but at this time, the structure of the food generates a unique odor in addition to dripping, and this odor significantly reduces the product value. It was causing this. In particular, once frozen and thawed, the fibers themselves are destroyed, resulting in a significant odor, and it is highly desirable to establish effective measures to prevent or eliminate this odor. .

Products other than the above fresh foods, such as sanitary products, diapers,
Regarding products that require high water absorption, such as disposable rags and paper towels, there are still insufficient effective measures in terms of preventing bacterial contamination and deodorization in addition to water absorption. It has been desired to develop a new product with specific functions that can solve these problems.

Further, conventional water-absorbing sheets have a problem in that the absorbed moisture permeates to the back surface of the water-absorbing sheet, making it difficult to handle.

Under these circumstances, the inventors of the present invention have conducted extensive research in order to solve the problems of the above-mentioned conventional technology. As a result, the present inventors have combined a super absorbent material and a specific functional material with a specific packaging form. The present invention was completed based on the discovery that the above problems can be solved by constructing a water-absorbing sheet that has both water-absorbing properties and specific functions.

That is, an object of the present invention is to provide a novel water-absorbing sheet that has high water-absorbing properties and specific functions, and is useful as a freshness-keeping material for fresh foods.

[Means to solve the problem]

The structure of the present invention adopted to achieve such an object is to sandwich and integrate a mixture consisting of a superabsorbent polymer material and a specific functional material between specific packaging materials, and to further integrate the mixture into a specific packaging material. It is characterized by packaging in the form of
Specifically, they are as follows.

(1) A mixture 3 containing a super absorbent material and a specific functional material is sandwiched and integrated between the inner layer 1 and the inner layer 2, and then folded into the outer layer 5, which is wider than the sandwiched body, and then, A functional water-absorbing sheet characterized in that the outer layer 4 is applied from above, the side portions and end portions are heat-sealed, and the entire body is wrapped by the outer layer 4 and the outer layer 5.

(2) The functional water-absorbing sheet described in (1) above, wherein the specific functional material is a material having one or more specific functions such as antibacterial properties, deodorizing properties, or ethylene gas adsorption properties.

(3) A water-absorbing sheet having the functionality described in (1) above, characterized in that the mixture is sandwiched and integrated between inner layer 1 and inner layer 2 together with a binder made of a thermoplastic resin.

(4) A water-absorbing sheet having the functionality described in (1) above, which is entirely sandwiched and integrated using heated embossing rolls.

Next, the present invention will be explained in detail based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which a mixture 3 containing a highly water-absorbent material and a specific functional material is fixed and integrated between an inner layer 1 and an inner layer 2, and then the sandwich is The outer layer 5, which is wider than the garment, is folded into the side portion, and then the outer layer 4 is applied from above, the side portions and end portions are heat-sealed, and the whole is packaged with a packaging consisting of the outer layer 4 and the outer layer 5. FIG. 2 is a cross-sectional view of a water absorbent sheet having functionality obtained by

Examples of packaging materials constituting the inner layer and outer layer include:
Sizeless paper, non-woven fabric, water permeable porous sheets such as hydrophilic polyethylene and polypropylene, cellophane, vinylon film, thermoplastic film that has been foamed to have fine continuous pores during film production, inorganic materials or high melting point cores. Papers in which microscopic pores are formed by stretching with a generator added, other mixed papers of polyethylene or polypropylene and valves, laminates of paper and nonwoven fabrics, cellulose films formed with viscose on sized paper and nonwoven fabrics, etc. Appropriate types of water permeable materials are used, such as cellulose membranes with fine pores formed therein, as well as appropriate types of non-water permeable materials such as plastic films made of thermoplastic resin, PE paper, and metal foils. It is also possible to use flexible materials.

In particular, nonwoven fabrics include nonwoven fabrics that are partially or entirely made of thermoplastic resin, such as rayon, bulb fibers, etc.
It is preferable to use a nonwoven fabric impregnated with or mixed with a resin such as polyolefin, polyester, or polyamide, or a nonwoven fabric made of fibers such as polyolefin, polyester, or polyamide, and has a basis weight of 15 to 100 g/
m” is preferred.

Further, as the paper, a layer of soft paper such as tissue paper with a basis weight of 15 to 60 g/s'' is used, but there is no particular limitation.

Among the materials such as the super absorbent material and specific functional materials that make up the mixture (3), the functional materials include appropriate functions such as antibacterial agents, deodorizing agents, and ethylene gas absorbers, or appropriate combinations of these. Substances or compositions with multiple functionalities are used.

Antibacterial agents include antibacterial metal materials such as silver, copper, zinc, tin, lead, bismuth, cadmium, chromium, and mercury, as well as zeolite, activated carbon, silica, activated clay, acid clay, alumina, activated bauxite, and bone charcoal. , molecular sieves, or other carriers are preferable, but these antibacterial materials, types of carriers, and amounts used are not particularly limited.

Examples of deodorizing agents include the following.

(1) Physical adsorption deodorizers such as neutral activated carbon, fibrous carbon adsorbent, zeolite, activated alumina, acid clay, etc.

(2) Chemical deodorizer Acidic agents, alkaline agents, oxidizing agents, reducing agents, etc.

(3) Physical/chemical deodorizers such as alkaline or acid impregnated activated carbon, zeolite adsorbed with vegetable essential oils, etc.

(4) Other iron phthalocyanine derivatives, salts with a desulfurization effect such as zinc oxide, mixtures of iron (II) compounds, L-ascorbic acid and alum, etc.

In addition to these deodorizing agents, any deodorizing agent may be used as long as it has a deodorizing effect, and one or a mixture of two or more of these deodorizing agents can be used. These deodorizers are sheet ll
It is preferable to mix it with a super absorbent material and sandwich it between packaging materials so that it is sandwiched in a range of 0.1 to 150 g per 1z.

As the ethylene gas adsorbent, a carbonaceous molecular sieve adsorbed with bromine, preferably one having 4 to 6 micropores,
Alternatively, examples include particles having a particle size of 5 to 500 μm, which are obtained by adding acidic water in which sodium bromate or potassium bromate is dissolved to activated carbon and reacting the mixture, followed by drying and pulverization.

This kind of ethylene gas adsorbent is not affected by moisture,
That is, it is desirable because the adsorbed ethylene gas is not released in the presence of moisture. Generally, activated carbon, zeolite, Oya stone, etc., which are used as ethylene gas adsorbents, are not preferred because they release adsorbed ethylene gas in the presence of moisture.

In addition to these functional materials, materials having appropriate functions can be used, and the types thereof are not particularly limited.

Next, as super absorbent materials, starch/acrylate graft polymers, carboxymethylcellulose crosslinked products, vinyl alcohol/acrylate copolymers, polyacrylonitrile hydrolysates, crosslinked polyacrylates, modified polyvinyl alcohols, etc. , acrylic acid polymer, acrylate/acrylamide copolymer, isobutylene/maleic anhydride copolymer, etc., but any material having reliable water absorption properties can be used as appropriate. It is also possible to use two or more of these super absorbent polymer materials in combination. The layer of superabsorbent polymer material used is 0.00% per m'' of water.
A range of 1 to 200 g is preferred, and a range of 1 to 50 g is particularly desirable.

In order to sandwich and integrate the super absorbent material and the specific functional material between the packaging materials, thermoplastic resins such as polyolefin, polyamide, polyester, and other appropriate binders can be used.

In order to manufacture the water absorbent sheet having the functionality of the present invention using the above-mentioned materials, the following method can be used, for example.

That is, a mixture 3 of a highly absorbent material, a specific functional material, and a binder is uniformly spread over the inner layer material 2 in FIG. After the integrated base paper is cut into a certain size, it is folded into the outer layer 5 which is wider than the sandwich body, and then the outer layer 4 is folded from above.
It can be manufactured by heat-sealing the side portions with a gear roll, heat-sealing the end portions with a seal bar, and sandwiching and integrating the whole body through heated embossing rolls.

Note that the inner layer and outer layer materials are not limited to a single layer, and any appropriate laminate composed of multiple layers can be used.

As for the method of fixing and integrating through the above-mentioned heated embossing roll, (1) between the heated embossing roll and the heated embossing roll (2)
Examples of methods include: (3) between the HJO hot embossing roll and the heating roll; (4) between the heating roll and the heating roll; and (5) between the heating roll and the roll.

The functional water-absorbing sheet of the present invention can be used, for example, as a freshness-preserving material for fresh foods, such as in boxing, bagging, and packaging of fresh foods.
It is common to use it as is by inserting it between fresh foods when packaging trays, etc., but for foods that dry easily, the freshness-preserving material should be soaked with water in advance and used in a moist state. It is also possible.

In addition, it can be used in any appropriate form as a material for sanitary products, diapers, disposable rags, paper towels, and the like.

〔Effect of the invention〕

As explained above, the use of the water-absorbing sheet having the functionality of the present invention has the advantage that the freshness of fresh foods can be maintained easily and at low cost without requiring much effort. In addition, because specific functional materials are integrated with superabsorbent polymer materials, there is no risk of functional materials such as ethylene gas adsorbents and antibacterial agents contaminating fresh foods due to damage to the bag. It has unique effects such as.

Further, there is an advantage that a water absorbent sheet having any function depending on the purpose of use can be created by simply selecting and mixing a specific functional material together with a super absorbent material.

Furthermore, in the water-absorbing sheet of the present invention, when a super-absorbent material is sandwiched and integrated between a water-permeable packaging material and a non-water-permeable, ie waterproof, packaging material, the actual use It is possible to completely prevent the absorbed moisture from permeating to the back side of the water-absorbing sheet during the process, and the problems of conventional water-absorbing sheets can be solved by a simple means, and the added value of the water-absorbing sheet can be further increased. Therefore, its industrial value is extremely high.

EXAMPLES Below, the present invention will be explained in more detail by describing examples of the present invention.

〔Example〕

Example 1 Activated carbon (Shirasagi A, manufactured by Daiyo Yakuhin Kogyo Co., Ltd.) was applied as a deodorizer on paper (MSP25, manufactured by Maetel Co., Ltd.) with a basis weight of 25 g/m''.
), a mixture of organic acid and zinc oxide (manufactured by Dainichiseika Kagyo Co., Ltd.)
Guimshu 1300) at 10g/m" each, super absorbent polymer material (Aqua Keep 10SHP manufactured by Steel Chemical Co., Ltd.)
20g/m”, binder (Chemit R2 manufactured by Toshisha Co., Ltd.)
72S) in an amount of 1 gem", and the mixture layer was resin-coated (35 g/m" paper extrusion coated with polyethylene to a thickness of 30 μm).
25 g/11 gram of basis weight on the top of the resin coated paper.
12 sheets of paper were fed, passed through a heated embossing roll, and sandwiched and integrated.

Cut the above base paper to 320 x 210 mm,
Placed on non-woven fabric (NA240JP2096 manufactured by Kuraray Co., Ltd.),
The lower part of the nonwoven fabric was folded into the side of the base paper, the nonwoven fabric was fed from the upper part, and the side part was heat-sealed using a gear roll. The end portions were heat-sealed using a seal bar, and the whole was then passed through a heated embossing roll to be unified. After integration, 330 x 2 at the end
The above mixture layer was cut into 10 mm pieces, and the upper three layers,
A water-absorbing sheet sandwiched between the lower two layers of laminated material was produced.

Example 2 A pulverized product of 10 g/+s of ethylene gas adsorption/removal agent (Morusibon NGP6/8, manufactured by Kagoi Yakuhin Kogyo Co., Ltd.) and a binder (Kemit, manufactured by Toshisha Co., Ltd.) were placed on top of MSP25 (manufactured by Maetel Co., Ltd.) with a basis weight of 25 g/m''. R272S) at 0.5 g/+
s'', and then cover the paper with polyethylene coated (Maetel MSP25 extrusion coated with Mitsui Nisseki Polymer's To16P to a thickness of 30 μm) with the polyethylene coated side inside. It was passed through a heated embossing roll and fixed and integrated (heated embossing roll temperature: 160°C).

On top of the above-mentioned integrated paper coated with polyethylene, 20 g/s of super absorbent polymer material (Aqua Keep 10SHP, manufactured by Steel Chemical Co., Ltd.) and 1.0 g/s of binder (Kemit R272S, manufactured by Toshisha Co., Ltd.) are obtained. '', then covered with paper and passed through a heated embossing roll to settle and integrate (heated embossing roll temperature 16
0℃).

Cut this to 320 x 210 mm and non-woven fabric (
NA240JP2096 (manufactured by Kuraray), and the lower nonwoven fabric was folded into the side of the base paper. Further, a nonwoven fabric was fed from the top, and the side portions were heat-sealed using a gear roll. The end portions were heat-sealed with a seal bar, the whole was clamped and integrated, and the end portions were cut.

[Brief explanation of drawings]

FIG. 1 shows a sectional view of the water absorbent sheet of the present invention. 1...Inner layer 2...Inner layer 3...Mixture of super absorbent polymer material and functional material 4.
...Outer layer 5...Outer layer

Claims (4)

[Claims] (1) A mixture 3 containing a super absorbent material and a specific functional material is sandwiched and integrated between the inner layer 1 and the inner layer 2, and then folded into the outer layer 5, which is wider than the sandwiched body, and then, A functional water-absorbing sheet characterized in that the outer layer 4 is applied from above, the side portions and end portions are heat-sealed, and the entire body is wrapped by the outer layer 4 and the outer layer 5. (2) The functional water-absorbing sheet according to claim (1), wherein the specific functional material is a material having one or more specific functions such as antibacterial properties, deodorizing properties, or ethylene gas adsorption properties. (3) A functional water-absorbing sheet according to claim (1), characterized in that the mixture is sandwiched and integrated between the inner layer 1 and the inner layer 2 together with a binder made of a thermoplastic resin. (4) A functional water-absorbing sheet as set forth in claim (1), characterized in that the entire body is sandwiched and integrated by heated embossing rolls.