JPH02303826A - Water absorbing sheet having functionality - Google Patents

Abstract

PURPOSE:To keep the freshness of perishable foods in low cost by sandwiching a mixture containing a highly water-absorbable material and a specific functional material between inner layers to integrate the same with said inner layers and subsequently packing the sandwiched body with a packing bag formed of outer layers. CONSTITUTION:A mixture 3 is constituted of a highly water-absorbable material and a specific functional material and, as the 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. The mixture 3 of the highly water-absorbable material, the specific functional material and a binder is uniformly scattered on an inner layer material 4 and other inner layer material 2 is superposed on the layer of the mixture 3 and both inner layer materials are passed between heated embossing rolls to integrally hold the mixture between said materials and the integrated one is manually packed with outer layer material 1, 5 to be sealed hermetically and the whole is subsequently passed between heated embossing rolls to integrally hold the mixture between the inner and outer layer materials.

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]

Traditionally, it has been used to preserve the freshness of fresh foods, sanitary products, diapers,
Super absorbent resins are widely used as materials for disposable rags, paper towels, etc.

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 the 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 absorbing layer is provided using a coating agent containing a resin, and an adhesive layer is formed on the non-patterned part and other sheet base materials are laminated. There is.

[Problems to be Solved by the Invention] However, in the case of the above-mentioned prior art, for example, when packaging fruits and vegetables, two types of materials, a water-absorbent sheet and an ethylene gas adsorbent, are each individually housed in a packaging form. When packaging large quantities of fresh food, there are various problems such as extra effort, lowering overall work efficiency, and increasing costs. Ta.

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 tissue itself is destroyed, resulting in a significant odor, and there has been a strong desire to establish effective measures to prevent or eliminate this odor.

Products other than the above fresh foods, such as sanitary products, diapers,
For products that require high water absorption, such as disposable rags and paper towels, there are still insufficient effective measures in terms of water absorption, prevention of bacterial contamination, deodorization, etc.
In addition to water absorption, there was a desire to develop a new product with specific functions that could solve these problems.

Further, conventional water-absorbing sheets have a problem in that the absorbed moisture permeates into 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 has been completed by discovering that the above problems can be solved by constructing a water-absorbing sheet that has not only water-absorbing properties but also 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 being packaged in a bag, and specifically, it is as follows.

(1) After sandwiching and integrating the mixture 3 containing a super absorbent material and a specific functional material between the inner layer 2 and the inner layer 4,
A functional water-absorbing sheet characterized in that the sandwiched body is packaged in a packaging bag made of an outer layer 1 and an 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 the inner layer 2 and the inner layer 4 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 one embodiment of the present invention, in which a mixture 3 containing a super absorbent material and a deodorizing agent is sandwiched and integrated between an inner layer 2 and an inner layer 4 made of paper, and then FIG. 2 is a sectional view of a functional water-absorbing sheet product in which a sandwiched body is wrapped in a packaging bag made of an outer layer 1 and an outer layer 5 made of nonwoven fabric.

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 with microscopic pores formed by adding a generator and stretching, other mixed papers of polyethylene or polypropylene and pulp, laminates of paper and non-woven fabrics, sized papers and non-woven fabrics with cellulose membranes formed with viscose. Appropriate types of water-permeable materials are used, such as plastic films made of thermoplastic resin, PE paper, metal foils, etc. It is also possible to use materials.

In particular, nonwoven fabrics include nonwoven fabrics that are partially or entirely made of thermoplastic resin, ``for example, nonwoven fabrics made of fibers such as rayon and bulb impregnated with or mixed with resins such as polyolefin, polyester, and polyamide, or nonwoven fabrics made of polyolefin, polyester, and polyamide. It is preferable to use nonwoven fabric made of fibers such as
/-2 is preferred.

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

Among the materials such as the super absorbent material and the specific functional material that constitute the mixture 3, the functional material may have an appropriate function such as an antibacterial agent, a deodorizing agent, an ethylene gas absorbent, or a combination of these. Substances or compositions with multiple functions 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 deodorant Acidic agents, alkaline agents, oxidizing agents, reducing agents, etc.

(3) Physical/chemical odor agents Alkaline or acidic 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 (n) 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 1.
'! It is preferable to mix it with a super absorbent material and fix it between packaging materials so that it is sandwiched between 0.1 and 150 g per bag.

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 is added to activated carbon and reacted, and then dried.
Examples include pulverized particles with a particle size of 5 to 500 μm. Such ethylene gas adsorbents are desirable because they are not affected by moisture, i.e. they do not release the adsorbed ethylene gas in the presence of moisture, and are commonly used as activated carbon, zeolite, and Otani gas adsorbents. Stones and the like are undesirable because they release adsorbed ethylene gas when there is moisture.

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

Next, as highly water-absorbent materials, starch/acrylate graft polymers, carboxymethyl cellulose crosslinked products, vinyl alcohol/acrylate copolymers, polyacrylic acid l-IJ hydrolysates, crosslinked polyacrylic acid salt,
Examples include modified polyvinyl alcohol, acrylic acid polymer, acrylate/acrylamide copolymer, isobutylene/maleic anhydride copolymer, etc., and any material that has 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 amount of super absorbent polymer material used is sheet lll! The range is preferably from 0.1 to 200 g, especially from 1 to 50 g.
range is 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 on the inner layer material 4 in FIG. After the integrated base paper is cut into a certain size, it is hand packed into an outer layer material 1.5 consisting of a three-sided sealed pouch, sealed, and then the whole is passed through heated embossing rolls to be integrated. It can be manufactured by 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.

The method of sandwiching and integrating the above heating embossing rolls is as follows: (1) Between the heating embossing rolls (2) Between the heating embossing rolls and the heating rolls (3) Between the heating embossing rolls and the rolls (4) Between the heating rolls Between heating rolls (5) A method of integrating the heating roll and any one of the rolls between the rolls can be mentioned.

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 appropriate shapes as a material for sanitary products, diapers, disposable rags, vapor towels, etc.

〔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, if a super-absorbent material or the like is integrated between a water-permeable packaging material and a non-water-permeable, i.e. waterproof, packaging material, the water-absorbing sheet will not absorb water during actual use. It is possible to completely prevent the absorbed moisture from permeating to the back side of the water absorbing sheet.
Solving the problems of conventional water absorbing sheets with simple means,
Since the added value of the water-absorbing sheet can be further increased, its industrial utility value is extremely high.

Examples of the present invention are described below.

〔Example〕

Example 1 A mixture of activated carbon (Shirasagi A, Shikinichi Pharmaceutical Co., Ltd., Shikinichi Yakuhin Kogyo Co., Ltd.), an organic acid, and zinc oxide (manufactured by Dainichiseika Kagyo Co., Ltd.) was added as a deodorizer on top of MSP25 (manufactured by Maetel Co., Ltd.) with a basis weight of 25 g/a + 2. log/m" respectively, super absorbent polymer material (Aqua Keep 10SHP manufactured by Steel Chemical Co., Ltd.)
) was uniformly spread at 70g/a+" and a binder (Flow Pack manufactured by Tetsuko Kagaku Co., Ltd.) (EVA powder) was uniformly sprinkled in an amount of Log/g*", the paper was sandwiched with the same type of paper and passed through a heated embossing roll to be bonded and integrated. . (Heat roll temperature 140°C, embossing pressure 5kg/s”) Cut the above base paper into 320 x 200an,
Three-sided sealed pouch (size 330) made of non-woven fabric (Syntex PK105 manufactured by Mitsui Petrochemicals) with a basis weight of 25 g/m"
x 210m5) and sealed.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of a freshness-preserving material that is an embodiment of the present invention. 1... Nonwoven fabric (outer layer) 2... Paper (inner 1) 3... Mixture consisting of a highly absorbent material and deodorizing material 4...
Gion (inner layer) 5... Nonwoven fabric (outer layer)

Claims (4)

[Claims] (1) A packaging bag in which a mixture 3 containing a super absorbent material and a specific functional material is sandwiched and integrated between an inner layer 2 and an inner layer 4, and then the sandwiched body is made of an outer layer 1 and an outer layer 5. A functional water-absorbing sheet that is characterized by being wrapped in. (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 2 and the inner layer 4 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.