JP2815385B2 - Water absorbing sheet with functionality - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a functional water-absorbing sheet, and more particularly, to a freshness maintaining material for fresh food, sanitary products, diapers, disposable rags, paper towels, etc. The present invention relates to a water-absorbing sheet having a specific function that is useful as a material of a product requiring high water absorption.

[Conventional technology]

BACKGROUND ART Conventionally, super-water-absorbing resins have been widely used as materials for freshness-keeping materials for 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 leaching from fresh foods such as meat and seafood significantly reduces the freshness of the foods. Therefore, immediate removal of the free water is an important factor indispensable for maintaining freshness.

Conventionally, as a countermeasure against free water, a method of storing a water-absorbent sheet using a superabsorbent polymer material in a packaging form of fresh food and removing the free water by absorbing water is known as a prior art.

For fruits and vegetables such as fruits and vegetables,
Freshness is reduced due to ethylene gas generated from fruits and vegetables or condensation of water vapor due to respiratory action in a sealed state such as bagging or similar state.

In order to prevent such a decrease in freshness of fruits and vegetables, conventionally, for example, during the transportation of fruits and vegetables packed in a box or bag with two types of freshness retaining materials such as a water-absorbent sheet using a superabsorbent resin and an ethylene gas adsorbent, Methods for storing are known.

Other water-absorbent sheet products used for various applications include, for example, those having a structure in which a highly water-absorbent resin powder is sandwiched between two water-permeable sheet substrates, and a highly water-absorbent resin on a sheet substrate surface. In addition to providing a pattern-shaped water-absorbing layer with a coating agent containing, and forming an adhesive layer on the non-patterned portion and pasting another sheet substrate, various forms are known. .

[Problems to be solved by the invention]

However, in the case of the above-mentioned conventional technology, for example, when packaging fruits and vegetables, it is necessary to separately store the two types of materials, that is, the water-absorbent sheet and the ethylene gas adsorbent, in a packaging form. In the case of packaging foods, there are various problems, such as extra time and labor, a reduction in overall work efficiency, and an increase in cost.

Furthermore, during transportation, the sachet containing the ethylene gas adsorbent is damaged, and the ethylene gas adsorbent inside adheres to the surface of the fruits and vegetables, thereby deteriorating the appearance of the product. There was a risk of contamination.

And, the packaging body for ordinary fresh food uses ordinary packaging materials, and the packaging materials themselves include:
For example, since there is no specific function such as antibacterial property, it is impossible to reliably prevent freshness deterioration of fresh food caused by contamination by food deteriorating bacteria with the water absorbing sheet alone, and establish effective measures Was desired.

In addition, animal foods such as meat and seafood are generally stored and distributed in a refrigerated state.At this time, a unique smell other than drip is generated from the tissue of the food, and this smell significantly lowers the commercial value. Was causing it. In particular, once frozen and thawed, since the tissue itself is destroyed, the generation of odor is remarkable, and it has been strongly desired to establish an effective measure for preventing or removing this odor.

Products other than the above fresh foods, for example, sanitary products, diapers, disposable rags, even products that require high water absorption such as paper towels, are still effective in terms of prevention of bacterial contamination in addition to water absorption, deodorization, etc. The measures are not sufficient, and the development of new products having specific functions that can be solved in addition to water absorption has been desired.

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

Under these circumstances, the present inventors have conducted intensive studies to solve the above-mentioned problems of the conventional technology, and as a result, combined a superabsorbent material and a specific functional material with a specific packaging material. The present inventors have found that the above problems can be solved by forming a water absorbing sheet having specific functions together with water absorbing properties, and have completed the present invention.

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

[Means for solving the problem]

The configuration of the present invention adopted to achieve such an object is to sandwich and integrate a mixture of a superabsorbent polymer material and a specific functional material between specific packaging materials to form a sheet-like product. It is characterized by comprising, specifically, it is as follows.

(1) a mixture containing a highly water-absorbing material and another specific functional material, one of which is formed of a water-impermeable laminate;
A water-absorbent sheet having functionality, characterized in that at least one is sandwiched and integrated between a first packaging material (1) and a second packaging material (2) comprising a laminate of three or more layers.

(2) First packaging material (1) or second packaging material (2)
Is composed of a first base material (11), a second base material (12), and a third base material (13), and the first base material (11) and the second base material (12)
Alternatively, the functional water-absorbing sheet according to the above (1), wherein the third substrate (13) is a plastic film made of a thermoplastic resin or a paper having water impermeability.

(3) The functional water-absorbent sheet according to the above (1), wherein the specific functional material is a material having at least one specific function such as antibacterial property, deodorizing property, or ethylene gas adsorbing property.

(4) The mixture according to (1), wherein the mixture is sandwiched and integrated between the first packaging material (1) and the second packaging material (2) together with a binder made of a thermoplastic resin. Water absorbing sheet with functionality.

(5) The functional water-absorbing sheet according to the above (1), wherein the whole is sandwiched and integrated by a heated embossing roll.

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

FIG. 1 shows one embodiment of the present invention, in which a mixture containing a superabsorbent material and a specific functional material (3) is shown.
A packaging material (1), one of which is a water-impermeable laminate and at least one of which is a laminate of three or more layers;
It is sectional drawing of the water absorption sheet | seat which has the functionality comprised by pinching and integrating between (2).

FIG. 2 shows another embodiment of the present invention. The mixture (3) is made of a base material (11), a plastic film made of a thermoplastic resin or a base material (12) made of a water-impermeable paper. ), And a functional water-absorbent sheet formed by being sandwiched and integrated between a packaging material (1) composed of a base material (13) and another packaging material (2) having water permeability. is there.

The packaging material made of a water-impermeable laminate (the packaging material (2) in FIG. 1) is made of a plastic film made of a thermoplastic resin or a paper that has been subjected to a water-impermeable process such as polyethylene-coated paper as a base material. The laminate is preferably used as the material, but any material may be used as long as it is a water-impermeable material, and various synthetic resin films, sheets, metal foils and the like can be used. As the water-impermeable substrate such as a plastic film made of the thermoplastic resin, it is desirable to use an appropriate substrate such as a nonwoven fabric, paper, or another thermoplastic resin film in the form of a laminate.

As shown in FIG. 2, the laminate is preferably in a form in which a non-permeable substrate such as a plastic film made of the thermoplastic resin is used as an intermediate layer, but the non-permeable substrate is used as an outer layer or an inner layer. The form of the laminate may be, for example,
An appropriate combination is selected according to various purposes such as overall decoration, feeling or reinforcement. The other substrate other than the non-permeable substrate of the laminate is used to reinforce the non-permeable substrate and prevent the non-permeable substrate from being damaged at the time of embossing by heating, or This is for imparting cushioning properties to the flexible sheet. And specifically,
Paper and nonwoven fabric are used.

On the other hand, packaging materials having water permeability are, for example, non-sized paper, nonwoven fabric, hydrophilic water-permeable porous sheets such as polyethylene and polypropylene, cellophane, vinylon film, and a thermoplastic film to have fine communication holes during film production. Foamed, inorganic or high melting point nucleating agent added and stretched to form fine communication holes, and any other papers with a certain degree of water permeability, such as mixed paper of polyethylene, polypropylene and pulp The material may be composed of any of the above materials, and its thickness and the degree of lamination are not particularly limited as long as it has a certain degree of water permeability and strength.
Preference is given to those obtained by forming a cellulose membrane with viscose on sized paper or nonwoven fabric, or those having fine pores formed in the cellulose membrane.

As the nonwoven fabric constituting the laminate, a part or all of the nonwoven fabric is a nonwoven fabric of a thermoplastic resin, for example, a nonwoven fabric in which a resin such as rayon or pulp is impregnated or mixed with a resin such as polyolefin, polyester, or polyamide, or It is preferable to use a nonwoven fabric or the like made of fibers such as polyolefin, polyester, polyamide, etc., and a material having a basis weight of 15 to 100 g / m ² is suitable.

In addition, as the paper, a paper on which soft paper such as a tissue paper having a basis weight of 15 to 60 g / m ² is laminated is used, but the paper is not particularly limited.

Among the materials such as the highly water-absorbing material and the specific functional material constituting the mixture (3), the functional material may be an appropriate function such as an antibacterial agent, a deodorant, an ethylene gas absorbent, or a combination thereof. A substance or a composition having a composite function of is used.

Antibacterial agents include antibacterial metallic materials such as silver, copper, zinc, tin, lead, bismuth, cadmium, chromium, and mercury, zeolite, activated carbon, silica, activated clay, acid clay, alumina, activated bauxite, and bone charcoal. And those supported on a carrier such as molecular sieve, but the antibacterial material, the type of the carrier and the amount used thereof are not particularly limited.

 The following are illustrated as a deodorant.

(1) Physical adsorption deodorant Neutral activated carbon, fibrous carbon adsorbent, zeolite, activated alumina, acid clay, etc.

(2) Chemical deodorants Acidic, alkaline, oxidizing, and reducing agents.

(3) Physical and chemical deodorants Alkaline or acidic impregnated activated carbon, zeolites adsorbing vegetable essential oils, etc.

(4) Others Iron phthalocyanine derivatives, salts having a desulfurizing action such as zinc oxide, and mixtures of iron (II) compounds with L-ascorbic acid and alum.

Any deodorant other than these deodorants may be used, and a mixture of one or more of these deodorants can be used. These deodorants are 1m in sheet
It is preferable to mix with the superabsorbent material and sandwich between the packaging materials so that the sandwich is held in the range of 0.1 to 150 g per ² pieces.

As the ethylene gas adsorbent, a carbonaceous molecular sieve adsorbing bromine, preferably having a micropore of 4 to 6 °, or an acid water in which sodium bromate or potassium bromate is dissolved is added to activated carbon and reacted. , Drying,
Pulverized particles having a particle size of 5 to 500 μm are exemplified.
Such ethylene gas adsorbent has no influence of moisture,
That is, it is desirable because the adsorbed ethylene gas is not released in the presence of moisture. In general, activated carbon, zeolite, Oyaishi, and the like used as an ethylene gas adsorbent are not preferable because moisture adsorbs the released ethylene gas.

In addition to these functional materials, it is possible to use a material having an appropriate function, and the type is not particularly limited.

Next, examples of the superabsorbent material include starch / acrylate graft polymer, carboxymethylcellulose crosslinked product, vinyl alcohol / acrylate copolymer, polyarylonitrile hydrolyzate, crosslinked polyacrylate, modified Examples thereof include polyvinyl alcohol, acrylic acid polymer, acrylate / acrylamide copolymer, isobutylene / maleic anhydride copolymer, and any other material having high water absorption can be used as appropriate. It is also possible to use two or more of these superabsorbent polymer materials in combination.
The amount of superabsorbent polymer material, the sheet 1 m ² per 0.1
A range of 200 mg 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, polyolefin, polyamide,
A thermoplastic resin such as polyester and other appropriate binders can be used.

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

That is, a mixture (3) of a superabsorbent material, a specific functional material and a binder is evenly sprayed on the inner layer material of the packaging material (2) in FIG. 1, and the inner layer material of the packaging material (1) is overlaid. The base paper after the integration is cut to a certain size, placed on the intermediate layer material of the packaging material (2), and the lower intermediate layer material is rolled up to the size of the base paper. After feeding the outer layer material of the wrapping material (1) and the outer layer material of the wrapping material (2) from the lower part, respectively, or packing the base paper wrapped with the intermediate layer material into a three-side seal pouch and sealing it. The whole can be manufactured by sandwiching and integrating the whole through a heating embossing roll described later.

As shown in FIG. 2, a mixture (3) of a highly water-absorbent material, a specific functional material and a binder is evenly spread on the inner layer material of the packaging material (2), ) Are overlapped with each other through a heated embossing roll to be described later, and the integrated base paper is cut into a predetermined size. A base material such as a plastic film made of a thermoplastic resin or a water-impermeable paper is further provided on the upper part. 12) and the base material (11) are fed to form a three-layer packaging material. If necessary, the packaging material is wound around the base paper side, and the outer layer material of the packaging material (2) is fed from the bottom. Then, the side can be heat-sealed, and the whole can be passed through a heated embossing roll to be sandwiched and integrated to be manufactured.

In addition, a packaging material composed of a water-impermeable laminate and a packaging material composed of a water-permeable laminate are prepared in advance, the upper mixture (3) is interposed between the packaging materials, and the whole is sandwiched through a heated embossing roll. It may be manufactured by attachment and integration, and the lamination process of each base material can be appropriately changed.

(1) Between the heating embossing roll and the heating embossing roll (2) Between the heating embossing roll and the heating roll (3) Between the heating embossing roll and the roll (4) The heating roll Heating rolls (5) A method of passing through and integrating one of the rolls between the heating rolls.

The water-absorbing sheet having the functionality of the present invention is generally used as it is as a material for maintaining freshness of fresh food, for example, as it is inserted between fresh foods in boxing, bagging, tray packaging, and the like of the fresh foods. As a matter of course, it is also possible to use a food that is easy to dry, in which the freshness-keeping material is made to absorb water in advance to make it wet.

In addition, it is also possible to process the material into an appropriate form and use it as a material for sanitary products, diapers, disposable rags, paper towels and the like.

〔The invention's effect〕

As described above, the use of the functional water-absorbent sheet of the present invention has an advantage that freshness of fresh food can be maintained easily and at low cost without labor.
In addition, because the specific functional material is integrated with the superabsorbent polymer material, there is no danger of functional materials such as ethylene gas adsorbent and antibacterial agent contaminating fresh food due to breakage of the bag. It has unique effects such as:

In addition, there is an advantage that a water-absorbing sheet having an arbitrary function can be produced according to the purpose of use only by appropriately selecting and mixing a specific functional material together with the highly water-absorbing material.

Furthermore, the water-absorbing sheet of the present invention is formed by sandwiching and integrating a highly water-absorbing material or the like between a packaging material having water permeability and a packaging material having non-water permeability, that is, waterproof. It is possible to completely prevent the absorbed water from permeating to the back surface of the water-absorbent sheet during use, solve the problems of the conventional water-absorbent sheet by simple means, and further increase the added value of the water-absorbent sheet. Therefore, its industrial value is extremely high.

In addition, since the water-impermeable laminate has a reinforcing base material or a base material that imparts cushioning properties, it is possible to prevent damage to the water-impermeable base material when the water-absorbent sheet is heated and embossed, or There is an advantage that the cushioning properties of the seat can be enhanced.

 Hereinafter, Examples and Comparative Examples of the present invention will be described.

Example 1 A mixture of activated carbon (Shirasagi A manufactured by Takeda Pharmaceutical Co., Ltd.), an organic acid and zinc oxide (manufactured by Dainichi Seika Kogyo Co., Ltd.) was used as a deodorizing agent on a paper having a basis weight of 25 g / m ² (MSP25 manufactured by Meitel). Dime shoe 1300) 10 g / m ² , 70 g / m ² superabsorbent polymer material (Aqua Keep 10 SHP, manufactured by Iron and Steel Science), 10 g / m ² of binder (Flowback, manufactured by Iron and Steel Chemical) (EVA powder)
^Then , the mixture layer was sandwiched with the same kind of paper, passed through a heating embossing roll, and integrated by sandwiching (heating roll temperature: 140 ° C., embossing pressure: 5 kg / m ² ).

The base paper was cut into a size of 320 × 200 mm, and a non-water-permeable base material obtained by coating polyethylene on paper (MSP25 manufactured by Meitel Co., Ltd. and M-16p manufactured by Mitsui Nisseki Polymer Co., Ltd., extrusion-coated with a thickness of 30 μ) was used. Cover with the polyethylene coating inside, and 25 g / m ² basis weight from above
Nonwoven fabric (Shintex PK105 manufactured by Mitsui Petrochemical Co., Ltd.) was fed, and the upper nonwoven fabric was folded into the side of the base paper. Further, the nonwoven fabric is fed from the lower part, the side part is heat-sealed by a gear roll, the end part is heat-sealed by a seal bar, and the whole is sandwiched and integrated through a heating embossing roll. A water absorbing sheet was produced.

Comparative Example 1 In Example 1, a water-absorbing sheet without a deodorant was produced.

Experimental Example 1 A frozen aji was thawed, packaged using each water-absorbent sheet, stored in a refrigerator at 7 ° C. for 3 days, and the generation of drip and the generation of odor were compared. Table 1 shows the results.

As is clear from the results in Table 1, when the water-absorbent sheet of this example was used, it was found that neither drip nor odor was generated.

Example 2 A mixture of activated carbon (Shirasagi A, manufactured by Takeda Pharmaceutical Co., Ltd.), an organic acid and zinc oxide (manufactured by Dainichi Seika Kogyo Co., Ltd.) as a deodorant on paper having a basis weight of 25 g / m ² (MSP25, manufactured by Meitel) Daimushu 1300) respectively 10 g / m ^2, uniformly spread superabsorbent polymer material (steel chemical Co. AQUA kEEP 10SHP) a 20 g / m ^2, binder (manufactured by Toray Industries, Inc. Kemitto R272S) in an amount of 1 g / m ² And
The mixture layer is resin-coated paper (35 g / m ² paper is extrusion coated with polyethylene at a thickness of 30μ)
Then, paper having a basis weight of 25 g / m ² was further fed onto the upper part of the resin-coated paper, passed through a heated embossing roll, and integrated by being sandwiched.

The base paper was cut into a size of 320 × 210 mm, placed on a non-woven fabric (NA240JP2096, manufactured by Kuraray Co., Ltd.), and the lower non-woven fabric was folded into the base paper side. Further, the nonwoven fabric was fed from the upper part, and the side part was heat-sealed with a gear roll. The end portion was heat-sealed with a seal bar, and the whole was passed through a heated embossing roll to be sandwiched and integrated. After integration
A water-absorbent sheet was produced in which the mixture layer cut at 330 × 210 mm at the end was sandwiched between three upper layers and two lower layers of laminated material.

Comparative Example 2 ^On a paper having a basis weight of 25 g / m ² (MSP25 manufactured by Meitel), a superabsorbent polymer material (Aquakeep 10SHP manufactured by Iron and Steel Chemical Co., Ltd.) was added.
0g / m ² , 1g / m binder (Toray Co., Ltd. Chemit R272S)
It was uniformly sprayed in an amount of ^2, sandwiched by paper having a basis weight of 35 g / m ^2, and further feed the paper basis weight 25 g / m ^2, through a heat embossing roll,
Nipped and integrated.

The base paper was cut into a size of 320 × 210 mm, placed on a non-woven fabric (NA240JP2096, manufactured by Kuraray Co., Ltd.), and the lower non-woven fabric was folded into the base paper side. Further, the nonwoven fabric was fed from the upper part, and the side part was heat-sealed with a gear roll. The end portion was heat-sealed with a seal bar, and the whole was passed through a heated embossing roll to be sandwiched and integrated. After integration
The end portion was cut into 330 × 210 mm to produce a water-absorbing sheet.

Experimental Example 2 The water-absorbing sheet produced as described above was placed on white paper, and 200 ml of water colored with blue ink was absorbed. After standing for a certain period of time, the water-absorbing sheet was peeled off, and the degree of coloring under the water-absorbing sheet was determined. Table 2 shows the results.

As is clear from Table 2, it was confirmed that the use of the water-absorbing sheet having the preventive property of the present invention can completely prevent the permeation of the absorbed water to the back surface.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a functional water-absorbent sheet showing one embodiment of the present invention. FIG. 2 is a cross-sectional view of a functional water-absorbent sheet showing another embodiment of the present invention. (1) packaging material (2) packaging material (3) mixture (11) substrate (12) composed of plastic film made of thermoplastic resin or non-permeable paper Substrate (13) ... Substrate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI A61F 13/18 380Z (58) Fields investigated (Int.Cl. ⁶ , DB name) B32B 1/00-35/00 A41B 13 / 02 A61F 13/18 B65D 81/24-81/30 B01J 20/28

Claims (5)

(57) [Claims] 1. A first package comprising a mixture containing a superabsorbent material and another specific functional material, one of which comprises a water-impermeable laminate and at least one comprising a laminate of three or more layers. A functional water-absorbent sheet characterized by being sandwiched and integrated between a material (1) and a second packaging material (2). 2. The first packaging material (1) or the second packaging material (2) comprises a first substrate (11), a second substrate (12), and a third substrate (13), 2. The method according to claim 1, wherein the first base material, the second base material or the third base material is a plastic film made of a thermoplastic resin or water-impermeable paper. Water absorbing sheet with functionality. 3. 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 property, deodorizing property, and ethylene gas adsorbing property. 4. The composition according to claim 1, wherein the mixture is sandwiched and integrated between the first packaging material (1) and the second packaging material (2) together with a binder made of a thermoplastic resin.
A water-absorbent sheet having the functionality described. 5. The functional water-absorbing sheet according to claim 1, wherein the whole is sandwiched and integrated by a heated embossing roll.