JPH02252555A - Water absorbing sheet having functionality - Google Patents

Abstract

PURPOSE:To obtain a water absorbing sheet equipped with high water absorbability and specific function by constituting the water absorbing sheet by integrally holding and bonding a mixture consisting of a highly water-absorbable polymer material and a specific functional material between specific packing materials. CONSTITUTION:A water absorbing sheet is formed by holding a mixture 3 containing a highly water-absorbable polymer material and a specific functional material between papers 2, 4 and further holding the same between nonwoven fabrics 1, 5. Each of the nonwoven fabrics 1, 5 is one partially or entirely composed of a thermoplastic resin and, for example, a nonwoven fabric wherein a fiber such as rayon or pulp is impregnated or mixed with a resin such as polyolefin, polyester or polyamide or a nonwoven fabric composed of a fiber formed from polyolefin, polyester or polyamide is used and pref. has a basis wt. of 15-100g/m<2>. As each of the papers 2, 4, one composed of laminated soft papers having a basis wt. of 15-60g/m<2> is used. As the functional material, an antibacterial agent, a deodorant, an ethylene gas absorber or the like are used. The use amount of the highly water-absorbable polymer material is pref. 0.1-200mg/m<2>.

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 various 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 that exudes from fresh foods such as meat and fish and shellfish can significantly reduce the freshness of the foods concerned. Therefore, immediate removal of free water is an important factor in maintaining freshness.

Conventionally, as a measure 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 placed in the packaging form of fresh food to absorb and remove 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 sheet base materials, at least one of which is water-permeable, Various forms are known, such as those in which a water-absorbing layer is provided in a pattern using a coating agent containing a water-absorbing resin, and an adhesive is formed on the non-patterned part to bond other sheet base materials. There is.

[Problem that the invention attempts to solve]

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 less likely to be contaminated by food spoiling bacteria. It is impossible to reliably prevent the deterioration in freshness of fresh foods caused by this problem by using a water-absorbing sheet 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 produces a unique odor in addition to dripping, which can significantly reduce the product value. It had become. In particular, when frozen at -degrees and thawed, the tissue itself is destroyed, resulting in a significant odor, and an effective measure to prevent or eliminate the odor has been desired.

Products other than the above-mentioned fresh foods, such as sanitary napkins, diapers, disposable miscellaneous goods, paper towels, and other products that require high water absorption are still effective in terms of not only water absorption but also prevention of bacterial contamination and deodorization. There are not enough measures,
In addition to water absorption, there was a desire to develop a new product that had functions that could solve these problems.

Under these circumstances, the inventors of the present invention have conducted intensive research to solve the above-mentioned problems of the prior art. As a result, the inventors have combined a highly water-absorbing material with a specific functional material to achieve both water absorption and specific properties. The present invention has been completed by discovering that the above problems can be solved by constructing a water absorbing seam with functions.

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

[Means to solve the problem]

The structure of the present invention adopted to achieve this object is to construct a water absorbent sheet by sandwiching a mixture of a super absorbent polymer material and a specific functional material between specific packaging materials. The specific features are as follows.

(1) A mixture containing at least a highly absorbent material and a specific functional material is sandwiched between packaging material 1 and packaging material 2, each consisting of a two-layer laminate with an inner layer of paper and an outer layer of nonwoven fabric. A functional water-absorbing sheet characterized by an integrated structure.

(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 integrally sandwiched between packaging material 1 and packaging material 2 together with a binder made of a thermoplastic resin.

(4) A water-absorbing sheet having the functionality described in (1) above, characterized in that the entire body is integrally sandwiched by heated embossing rolls.

Next, the present invention will be explained in more detail. FIG. 1 is a sectional view showing one embodiment of the present invention, and as a packaging material,
A two-layer laminate is used, with the inner layer made of paper and the outer layer made of nonwoven fabric.

That is, a mixture containing a superabsorbent polymer material and a specific functional material is sandwiched between papers 2 and 4, and further sandwiched between nonwoven fabrics 1 or 2 to be integrated. Nonwoven fabrics 1 and 5 are nonwoven fabrics in which part or all of them are made of thermoplastic resin,
For example, nonwoven fabrics made of fibers such as rayon and valve impregnated or mixed with resins such as polyolefin, polyester, and polyamide, or nonwoven fabrics made of fibers such as polyolefins, polyesters, and polyamides, etc., are used, and have a basis weight of 15 to 100 g/m. Preferably.

The papers 2 and 4 are not particularly limited, although a layer of soft paper such as tissue paper with a basis weight of 15 to 60 g/rrr is used.

Among the mixtures consisting of a super absorbent polymer material and various functional materials sandwiched between papers, the functional materials include antibacterial agents, deodorizing agents, ethylene gas absorbents, and other appropriate functions. Any combination of materials or compositions with multiple functionalities may be 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 desirable, but these antibacterial materials, the types of carriers, and the amounts used thereof are not particularly limited.

Examples of deodorizing agents include the following.

(1) Physical adsorption deodorizers such as neutral activated carbon, fibrous carbon adsorption side, 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 midiuban, and the like.

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 1r
It is preferable to mix it with a super absorbent polymer material and sandwich it between packaging materials so that it is sandwiched in a range of 0.1 to 150 g per rr.

As the ethylene gas adsorbent, a carbonaceous molecular sieve adsorbed with bromine, preferably one having 4 to 6 micropores,
Alternatively, acidic water in which sodium bromate or potassium bromate is dissolved may be added to activated carbon, reacted, dried, and pulverized to a particle size of 5 to 500 μm. Such ethylene gas adsorbents are desirable because they are not affected by moisture, i.e. the adsorbed ethylene gas will not be released in the presence of moisture, and activated carbon, zeolite, and Oya stone, which are commonly used as ethylene gas adsorbents, etc. are undesirable 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.

The superabsorbent polymer materials used in the present invention include starch/acrylate graft polymers, carboxymethylcellulose crosslinked products, vinyl alcohol/acrylate copolymers, polyacrylonitrile hydrolysates, and crosslinked polyacrylates. , modified polyvinyl alcohol, acrylic acid polymer, acrylate/acrylamide copolymer, isobutylene/maleic anhydride copolymer, and other resins having high water absorption properties. It is also possible to use two or more types of these super absorbent polymer materials.

The amount of super absorbent polymer material used is preferably in the range of 0.1 to 200 mg, particularly 1 to 50 g per 1rrf of sheet.
range is desirable.

A binder such as a thermoplastic resin such as polyolefin, polyamide, or polyester can be used to sandwich and integrate the superabsorbent polymer material and various functional materials between the packaging materials.

The following method can be used to produce the functional water-absorbing sheet of the present invention using the above-mentioned materials.

(1) A mixture 3 of a super absorbent polymer material, a specific functional material, and a binder is uniformly spread on the paper 4 shown in FIG. They are clamped and integrated using a pressure clamping method. manufactured 2
, 3.4 is cut to a certain size, placed in a bow made of 1°5 nonwoven fabric, and the opening is heat-sealed.

(2) A mixture of a super absorbent polymer material, a functional material, and a binder is uniformly spread on the paper 4 shown in FIG. Manufactured by clamping and integrating using a pressure clamping method.

The hot press sandwiching method includes: (1) between heated embossing rolls (2) between heated embossing rolls;
) Between a heating embossing roll and a heating roll; (3) Between a heating embossing roll and a roll; (4) Between a heating roll and a heating roll; and (5) Between a heating roll and a 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 absorb water in advance and use it in a moist state. It is also possible.

In addition, it can also be processed into an appropriate form and used as a material for sanitary products, diapers, disposable miscellaneous goods 111, paper towels, and the like.

〔Effect of the invention〕

As described 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:

Furthermore, it has the advantage of being able to create a water-absorbing sheet with any function depending on the purpose of use, simply by appropriately selecting and mixing specific functional materials with super-absorbent materials, and its industrial value is high. It is extremely expensive.

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

〔Example〕

Example 1 A mixture of activated carbon (Shirasagi A, manufactured by Souen Yakuhin Kogyo Co., Ltd.), an organic acid, and zinc oxide (Guimshu, manufactured by Dainichiseika Kagyo Co., Ltd.) as a deodorizer was placed on paper with a basis weight of 25 g/n10 (MSP25, manufactured by Maetel Co., Ltd.). 1300) at 10g/nf each, and super absorbent polymer material (Aqua Keep 10SHP manufactured by Steel Chemical Co., Ltd.)
) and 10g/rrf of binder (Flow Pack manufactured by Tetsuko Kagaku Co., Ltd.) (EVA powder) were uniformly scattered at an amount of 10g/rrf, sandwiched with paper of the same type, passed through heated embossing rolls, and sandwiched and integrated (heated). Roll temperature 140°C, embossing pressure 5)cg/a).

The above base paper was cut to 320 x 200m,
Three-sided sealed pouch (size 330) of non-woven fabric (Mitsui Petrochemical Co., Ltd. Syntex PX105) with a basis weight of 25 g/I
2101), sealed, and integrated the entire product by sandwiching it.

Comparative Example 1 A drip sheet in which no deodorizer was added in Example 1 was manufactured.

Experimental example: Thaw the frozen meat and package it according to the method shown in Table 1.
After storing in a refrigerator at 7°C for 3 days, the generation of drips and odor were compared. The results are shown in Table 1.

From the results shown in Table 1, it can be seen that when the drip sheet of this example is used, neither drip nor odor is generated.

Example 2 On paper (MSP25, manufactured by Maetel Co., Ltd.) with a basis weight of 25 g/nf, 10 g/rrf of a pulverized product of an ethylene gas adsorption remover (Molcibon NGP6/8, manufactured by Sokoen Pharmaceutical Industry Co., Ltd.) and a super absorbent polymer material ( Aqua Keep 105H manufactured by Seitetsu Kagaku Co., Ltd.
20g/ITf of P) and 1.5g/rd of binder (Kemi I-R272S manufactured by Toshisha Co., Ltd.) were uniformly scattered, and the paper was covered with polyethylene coated paper and sandwiched together (heated embossing roll temperature 160 °C).

This was cut to 320 x 210 mm, placed on a nonwoven fabric (NA240JP2096 manufactured by Kuraray Co., Ltd.), and the lower nonwoven fabric was folded into the side portion of the base paper. Furthermore, the nonwoven fabric is fed from the upper part, and the side part is heat-sealed by a gear roll. The end portion is heat-sealed with a seal bar, the whole is sandwiched and integrated, and the end portion is cut.

Comparative Example 2 A super absorbent polymer material (Aqua Keep 1 manufactured by Steel Chemical Co., Ltd.) was placed on paper with a basis weight of 25 g/rdO (MSP25 manufactured by Maetel).
03) 20g/bo of IP) and a binder (Chemit R272S manufactured by Toshisha Co., Ltd.) are uniformly sprinkled in the amount of Ig/rrfO, and then covered with polyethylene-coated paper and passed through a heated embossing roll to be sandwiched and integrated (heated embossing). roll temperature 160°C).

The base paper was cut into a size of 320 x 210+ nm, placed on a nonwoven fabric (NA240JP2096 manufactured by Kuraray Co., Ltd.), and the lower nonwoven fabric was folded into the side portion of the base paper. Furthermore, the nonwoven fabric is fed from the upper part, and the side part is heat-sealed by a gear roll. The end portion is heat-sealed with a seal bar, the whole is sandwiched and integrated, and the end portion is cut.

Experimental Example 1 The samples of Example 2 and Comparative Example 2 were cut into 50 x 50 mm, placed in a vial (125 d capacity), and ethylene gas was sealed in the vial so that the ethylene gas concentration was 300 ppm. Ethylene gas concentration was measured by gas chromatography.

Experimental Example 2 The samples of Example 2 and Comparative Example 2 were cut to 50 x 50 mm, placed in a vial (125 d volume) to absorb water, and ethylene gas was sealed in the bottle so that the ethylene gas concentration was 300 ppm. .

Ethylene gas concentration was measured by gas chromatography in the same manner as in Experimental Example 1.

The results of Experimental Example 1.2 are shown in Table 2.

4,

[Brief explanation of drawings]

Figure 1 shows Freshness preserving agent which is an embodiment of the present invention A cross-sectional view is shown. 1...Nonwoven fabric 2...Paper 3...Mixture of super absorbent polymer material and functional material (Deodorizing side) 4...Gi 5...Nonwoven fabric

Claims (4)

[Claims] (1) A mixture containing at least a highly absorbent material and a specific functional material is sandwiched between packaging material 1 and packaging material 2, each consisting of a two-layer laminate with an inner layer of paper and an outer layer of nonwoven fabric. A functional water-absorbing sheet characterized by an integrated structure. (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 packaging material 1 and packaging material 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 structure is integrally sandwiched by heated embossing rolls.