JPH0434098A - Elastic absorbing body having liquid permeability - Google Patents

Abstract

PURPOSE:To obtain the title absorbing material for water retaining agent of soil having high shape-retaining property by putting a mixed layer of an absorbing high polymer material and mixed pulp between mixed pulp layer 5 obtained by mixing regenerated and defibrated pulp with a low-melting composite fiber and integrally forming these ingredients by heat pressure treatment. CONSTITUTION:A mixed layer 1b of an absorbing high polymer material 2a and mixed pulp is put between mixed pulp layers 1a and 1a formed by mixing regenerated and defibrated pulp 2c with a low-melting composite fiber 2b to form a core material 1 consisting of at least three-layer structure and the core material is integrally formed into a prescribed and desired form by subjected the core material 1 to heat pressurizing treatment at a temperature in which main fiber of the core material 1 is not melted to provide the aimed elastic absorbing body having liquid permeability. Furthermore, in the core material 1, either one of the upper face or lower face is formed of a liquid-permeable sheet material 3 and the other is preferably covered with a sheet material formed of a liquid-impermeable sheet.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to various industrial applications, more specifically, to applications such as agricultural use, where it is embedded in the soil during vegetable cultivation, or around seeds, etc. It is used not only as a seed coating to increase the germination rate of seeds, but also for transporting vegetables, fruits, plants, etc. and keeping them fresh, as well as for civil engineering applications, as a dew prevention agent,
This invention relates to a liquid-permeable elastic absorbent material that can be used in a wide range of industrial applications such as water-stopping agents.

(Prior art) Conventionally, as materials for liquid absorption used in this type of industry, means for absorbing liquid by capillary action, such as absorbent cotton or cloth, have been used. Due to various problems such as the fact that the amount of water absorbed is small and the absorbed liquid is easily expelled when pressure is applied, in recent years, materials made by graft copolymerizing acrylonitrile to starch or cellulose, and materials made by graft copolymerizing acrylic acid and vinyl have been developed. There are many types of alcohol block copolymers and powdered or fibrous absorbent polymer materials generally called polymers that are processed into sheets or the like, and are used as appropriate.

That is, in the conventional method of processing an absorbent polymer material and using it for absorbing liquid, when the absorbent polymer material comes into contact with the liquid, it absorbs the liquid in a short time and swells, forming a gel. The gel is capable of retaining water by gelatinizing, and once gelled, the liquid does not release water even when pressure is applied.

(Problems to be Solved by the Invention) However, in the prior art, the absorbent polymer material is processed and used for liquid absorption, but there are the following problems.

That is, basically, the water absorption rate should be higher as the surface area becomes larger, but even if the surface area is increased by making the absorbent polymer material into fine particles, steps will be generated when water is absorbed, and it will be short at -7. The water absorption rate over time will decrease significantly.

Therefore, absorption of a very small amount of liquid can be compensated for by the absorbent polymer material alone, but if the amount of liquid per unit time increases beyond the rate of absorption within a unit time, the absorption will no longer be possible. There is a limit to the self-priming power of the polymer material alone.

Therefore, in the above case, the liquid can be absorbed by interposing the absorbent polymer material between thin paper or pulp materials, as is commonly used in disposable diapers, sanitary products, etc. A method is used to compensate for the water absorption rate of the absorbent polymer material by temporarily retaining it between thin paper or pulp materials, but in any industrial application, the amount of liquid for the appropriate use is There was a very serious problem in that the amount of water that could be temporarily retained between the tissue paper or pulp material by the above-mentioned means was not large enough, and most of the water would be separated from water before it was absorbed.

Furthermore, in the case of sheets made of absorbent polymer material processed into sheets as in the former case, and sheets in which the absorbent polymer material is simply interposed between thin paper or pulp materials as in the latter case, Even when used in accordance with the desired shape of the place or object, there are many problems such as the fact that the absorbent part is deformed and destroyed and the liquid absorption rate changes due to the lack of self-shape retention and strength. There is.

That is, the present invention solves all of the various problems mentioned above, and by applying heat and pressure treatment to the core material formed of a three-layer structure, it is possible to form a strong self-container that conforms to the shape of the object to be used. At the same time as having shape retention ability, even if a large amount of liquid permeates into the core material, it can temporarily retain a large amount of liquid without separating water, and can perform highly efficient liquid absorption. It is an object of the present invention to provide an elastic absorber with excellent liquid permeability.

(Means for Solving the Problems) The present invention takes the following measures to solve the above problems.

That is, firstly, in the present invention, the core material 1 is made of recycled crushed pulp 2C.
Mixed pulp layer 1 formed by mixing low-melting composite fiber 2b with
a and 1a, the absorbent polymer material 2 has at least a three-layer structure with a mixed layer 1b interposed with the mixed pulp, and the core material 1 has been previously heated and It has a structure in which it is integrally molded into a predetermined desired shape.

Secondly, the present invention provides a liquid-permeable elastic absorber having the above structure, in which the core material 1 is covered with a sheet material, and either the upper surface or the lower surface of the sheet material is covered with a liquid-permeable elastic absorber. The structure is such that one side is formed of a permeable sheet material 3 and the other side is formed of a liquid-impermeable sheet material 4.

Thirdly, the present invention provides a liquid-permeable elastic absorber having the above-mentioned second structure, in which either the upper surface or the lower surface of the sheet material covering the core material 1 is liquid-impermeable. The sheet material is provided with a water separation amount adjusting means 5 for adjusting the water separation I of the core material 1 or the liquid once absorbed.

Fourthly, the present invention resides in the liquid-permeable elastic absorber having the third structure, in which the water separation amount adjusting means 5 is formed of a plurality of through holes.

(Function) In the liquid permeable elastic absorber having the above structure, the core material 1 forming the elastic absorber has a low melting composite edge 11.
! 2b and recycled crushed pulp 2C are mixed.

Therefore, when the low melting composite fiber 2b mixed with the recycled crushed pulp 2C is subjected to heat and pressure treatment, the low melting composite fiber 2b is mixed with the recycled crushed pulp 2C.
! ! ! I! The molten fibers in 2b are the recycled crushed pulp 2c.
It is densely and intricately bridged, intertwined, and welded with the pulp fibers of the fibers, forming a fusion-bonded fiber structure that has an extremely large contact area and is strong and integral.

Since the absorbent polymer material 2a is scattered in the intermediate layer of the core material 1 forming the melt-bonded fiber structure as described above, the absorbent polymer material 2a is dispersed during water absorption. This will prevent them from becoming stepchildren.

Therefore, the core material 1 formed with the high-density melt-bonded TA fibrous structure as described above has highly efficient temporary water retention and water absorption properties when absorbing liquid, and at the same time, the core material 1 has high temporary water retention and water absorption properties when absorbing liquid. It also firmly holds the molded shape.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In Figure 1, 1a and 1a are mixed pulp layers, in which the main fibers are made of recycled crushed pulp 2c and a high melting point thermoplastic resin such as polypropylene or polyester, and a low melting point thermoplastic resin such as polyethylene is welded to the main fibers. The fiber is mixed with low melting composite fiber 2b.

A mixed layer 1b is formed by scattering an absorbent polymer material such as a polymer 2a on the mixed pulp (2b, 2c), and is interposed between the mixed pulp layers 1a, 1a.

The core material 1 of the liquid-permeable elastic absorber having a three-layer structure of the mixed pulp layers 1a, 1a and the mixed layer 1b is heated and pressurized at a temperature at which the main fibers do not melt. The welding fibers are melted and the crushed pulp is entangled with the main fibers and welded, but since the crushed pulp is recycled pulp, the crushed pulp fibers contain a very large amount of fine waste paper. It is contained in pieces.

Therefore, the mixed pulp layers 1a, 1a that have been subjected to the heat and pressure treatment as described above are made of high-density melt-bonded fibers in which each fiber is intricately entwined through pulp fibers containing fine pieces of waste paper. This structure allows it to firmly maintain its own shape and has a very large absorption contact area.

An absorbent polymer 23 having a liquid absorption capacity several hundred times its own weight is scattered and interposed between the mixed pulp layers 1a, 1a.

Therefore, the scattered polymer 28 is prevented from becoming stepchildren during liquid absorption, resulting in highly efficient liquid absorption.

Therefore, even if a large amount of liquid permeates in a single period of time, the three-layer elastic absorber made of the melt-bonded fiber structure can
3 absorbs the liquid and gels it, the mixed pulp temporarily retains a large amount of liquid without separating water, and then absorbs the retained liquid with high efficiency through the polymer 2a. It is something that can be gelled.

The liquid-permeable elastic absorber (core material 1) according to the present example has the above-mentioned configuration, and the elastic absorber according to the following is, for example,
The case where it is applied as a soil water retention agent will be explained.

First, as shown in FIG. 2(a), the elastic absorber is molded into, for example, a rectangular sheet 6 having a desired size by heat-pressing treatment.

Next, as shown in FIG. 6(B), the sheet 6 is buried underground 8 in a suitable land 7 having extremely poor water retention, such as a desert.

Therefore, even if a large amount of liquid passes through the sheet 6 in a single period of time through heat and pressure treatment, the sheet 6 temporarily retains the large amount of liquid without separating water until the sheet 6 absorbs the liquid. Thereafter, a melt-bonded fiber structure is formed that absorbs the retained liquid with high efficiency.

Therefore, for example, when rainwater or the like permeates into the land 7 due to rainfall, the sheet 6 buried in the ground 8 can retain a large amount of the rainwater without separating water, regardless of the amount of rainwater that permeates. Become.

Therefore, as mentioned above, the land 7 etc. where the sheet 6 that retains a large amount of rainwater is buried has sufficient water retention capacity, so it is suitable for cultivating food and plants in lands that do not have water retention capacity such as deserts. Or it can be used for greening etc.

In the above embodiments, the elastic absorber is used to temporarily retain water in soil, etc., but the use of such an absorber is by no means limited; it can be shaped into a desired shape by heat and pressure treatment. Since it is strongly self-retaining, it can also be applied to transport soil, etc. of bulbs and stocks of plants that constantly require moisture.

Hereinafter, other embodiments of the elastic absorber according to the present invention will be described with reference to the drawings, with reference to the case where the elastic absorber is used for transporting soil.

First, in FIG. 3, reference numeral 9 indicates a rectangular body obtained by cutting the elastic absorber into a desired size in advance. 3 is the rectangular body 9
It is a liquid-permeable sheet material that covers the upper surface part 10 of and is made of nonwoven fabric. Reference numeral 4 denotes a liquid-impermeable sheet material that covers the lower surface portion 11 of the rectangular body 9, and is formed of a laminated paper 4 made of polyfilm or the like. Reference numeral 12 denotes a peripheral portion where the nonwoven fabric 3 and the laminated paper 4 contact each other, and are integrally welded by heat sealing to cover the rectangular body 9.

The rectangular body (elastic absorber) 9 has the above configuration, but
Next, a case in which the rectangular body 9 is used will be explained.

First, as shown in FIG. 4(a), a plurality of concave portions 14 are provided on the upper surface 10 of the rectangular body 9 on a birch tree that can hold and store soil divided into ±13 plants to be transported, and then heated. When the pressure treatment is performed, the rectangular body 9 will firmly maintain its shape while having elasticity.

Thus, the rectangular body 9 provided with a plurality of concave portions 14 as described above is formed into a storage body that accommodates the stock divisions ±13.

Therefore, when water is poured into the rectangular body 9 after storing the stock division ±13 in the concave portion I4 attached to the rectangular body 9, the rectangular body 9 absorbs water ζ through the nonwoven fabric 3 and absorbs the water ζ through the nonwoven fabric 3. The raw water is completely stopped through the laminated paper 4, and water is retained at the same time.

Therefore, when the soil 13 is stored in the plurality of concave portions 14 provided on the upper surface 10 of the rectangular body 9, the soil 13 is absorbed by the soil 13 from the rectangular body 9. Therefore, the plant division ±13 can be carried in a state in which the moisture does not run out, and the plants in the soil 13 are reliably protected through the concave portion 14 of the rectangular body 9 without damaging them. It will be done.

Furthermore, as shown in FIG. 5, by providing a plurality of through holes 5 in the liquid-impermeable laminated paper 4 that covers the lower surface of the elastic absorber covered with birch, the liquid once gelled can be naturally absorbed. Since the amount of water separation (evaporation) can be arbitrarily adjusted, it can be used in a wide variety of industries.

In the above embodiments, the recycled crushed pulp mixed with the elastic absorber is made from waste paper, etc., but even if new pulp is mixed in to form the recycled crushed pulp. Well, the content etc. are not limited in any way.

Furthermore, low-melting composite fibers are made by mixing main fibers made of high-melting thermoplastic resins such as polypropylene and polyester with low-melting composite fibers mixed with welding fibers such as polyethylene, which is a low-melting thermoplastic resin. However, the point is that by applying heat, the fiber molecules of the re-disintegrated pulp are entangled with each other to form a high-density cross-linked structure, and after changing into the desired shape via the nuclide-linked structure, the shape is The type, composition, molecular structure, etc. of the fibers to be melted are not limited at all, as long as they have elastic self-retention and at the same time highly efficient liquid water retention and absorption properties.

In addition, as mentioned above, by applying heat to form the desired shape or by performing hot air treatment using far infrared rays, the inside of the elastic absorber formed from three layers can be more securely sealed. Can be melt-bonded.

As for the above-mentioned hot air treatment, it may be possible to use only far infrared rays or only hot air, and the combination thereof is not limited at all.

Furthermore, by mixing dissolving pulp obtained by processing the fiber length of monofilament polyethylene into pulp fiber length into one or both of the mixed pulp layers on the outside of the wound forming the three layers of elastic absorption, the mixed pulp It is possible to mold the layers with a stronger and more beautiful finish.

Although the elastic absorber having the above structure has at least three layers, it goes without saying that the present invention is not limited to this. A configuration may also be adopted in which the elastic body is formed by layering the elastic body.

Further, in this embodiment, in the liquid-permeable and liquid-impermeable sheet materials provided to cover the elastic body, a nonwoven fabric is applied to the former, and a laminated paper is applied to the latter, and the peripheral edge where the two contact each other is The point is that the elastic body is sealed with a seal, and the former is permeable to the liquid, and the latter is able to block the liquid. If so, the specific material, shape, etc. thereof are of course not limited at all, and the covering sheet material may be a single integral piece or a plurality of sheet materials sealed as appropriate.

In addition, in this embodiment, as a means for adjusting the amount of syneresis of the liquid once collected through the elastic absorber, the liquid-impermeable sheet material covering the elastic absorber is simply provided with a plurality of water repellents. Although only an adjustment hole is provided, a screw type, a fitting type, or other means may be used, and the specific method is not limited in any way.

Therefore, the present invention can be applied not only to the transportation of soil water retention agents and plants as described above, but also to a wide variety of industries, and the specific uses and forms of use are not limited. Moreover, all such configurations can be freely changed in design within the scope of the present invention.

(Effects of the Invention) As mentioned above, the present invention has a core material in which an absorbent polymer material and the mixed pulp are mixed between layers of a mixed pulp made by mixing low-melting composite fibers with recycled crushed pulp. Since the core material is composed of an elastic absorber having at least a three-layer structure with a mixed layer interposed therebetween, when the core material is subjected to heat and pressure treatment, the core material is made of a low-melting thermoplastic mixed in the mixed pulp. Through fiber melting, pulp fibers containing fine pieces of waste paper are complexly bridged with highly meltable thermoplastic fibers, which are the main fibers.1. 'By entangling and welding, an elastic absorbent body having a high density and extremely large liquid absorption contact area and a melt-bonded fiber structure that can firmly maintain its own shape is formed.

Therefore, as described above, an elastic absorbent material having a high-density melt-bonded fiber structure can firmly maintain its own shape even when a large amount of liquid is permeated at one time, and can maintain its shape without water separation over time. Because it can hold a large amount of liquid and can perform highly efficient liquid absorption through the absorbent polymer material, it can be applied as a soil water retention agent or water stop agent for land with extremely poor water retention. For example, when transporting plants that require constant hydration, it is possible to change the shape arbitrarily to accommodate the transported plants while maintaining their own shape. Since it can protect and transport plants etc. through its own elasticity, it can be applied to an extremely wide variety of industries.

Furthermore, since the liquid-permeable elastic absorber of the present invention uses waste paper called recycled crushed pulp for the mixed pulp layer forming the three layers, it is exceptional in that it saves resources and saves energy by recycling waste paper. It has also come to have significant effects.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a liquid-permeable elastic absorber according to the present invention. FIG. 2 shows an embodiment of the present invention, in which FIG. 2A is a perspective view and FIG. 2B is a sectional view of FIG. FIG. 3 is a sectional view showing another embodiment of the present invention. FIG. 4 shows another embodiment of the present invention, in which (A) is a sectional view and (B) is a plan view of (A). FIG. 5 is a sectional view showing another embodiment of the present invention. 1... Core material (elastic absorber) 1a+ 1a... Mixed pulp layer 1b... Mixed layer 2a... Absorbent polymer material 2b... Low melting composite fiber 2C... Regenerated crushing Pulp 3...Liquid-permeable sheet material 4...Liquid-impermeable sheet material Figure (B) Figure 3 Figure 1 to Figure 4 W> (B)

Claims (1)

[Claims] 1. The core material 1 has mixed pulp layers 1a, which are made by mixing recycled crushed pulp 2c with low-melting composite fibers 2b, and an absorbent polymer material 2a and the mixed pulp between them. It consists of at least a three-layer structure with a mixed layer 1b interposed therebetween, and the core material 1 includes:
A liquid-permeable elastic absorber characterized by being integrally molded into a predetermined desired shape by heat and pressure treatment. 2. In the liquid-permeable elastic absorber according to claim 1, the core material 1 is covered with a sheet material, and either the upper surface or the lower surface of the sheet material is covered with the liquid-permeable sheet material. A liquid-permeable elastic absorbent body, characterized in that the other side is formed of a liquid-impermeable sheet material 4. 3. In the liquid-permeable elastic absorber according to claim 2, the liquid-impermeable sheet material on either the upper surface or the lower surface of the sheet material covering the core material 1 is provided with the core material. A liquid-permeable elastic absorbent body characterized in that the material 1 is provided with a water separation amount adjusting means 5 for adjusting the water separation amount of the liquid once absorbed. 4. The liquid permeable elastic absorber according to claim 3, wherein the water separation amount adjusting means 5 is formed of a plurality of through holes.