JP2955258B2 - Super absorbent sheet and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly water-absorbent sheet using cellulose sponge chips and a method for producing the same.

[0002]

One of the sheets having a water-absorbing property, such as a water-wiping article, which has been conventionally used for handling water and the like, is excellent in ease of processing after use, and has excellent handleability. In many cases, a good thin paper hand wipe is used, and since the material itself is made of plant fiber, there is an advantage that no toxic gas is generated even when it is burned and disposed. However, the water absorption of the paper itself is not so high, and there has been no paper developed to increase the water absorption while maintaining the ease of handling and disposal. On the other hand, sponges are one of the highly water-absorbing substances, and are used for various purposes because of their high water absorption and good water retention. Cellulose sponges using cellulose as a sponge material have been developed, and there is an advantage that no toxic gas or the like is generated even when incinerated, and environmental destruction does not occur. However, the cellulosic sponge formed in a block shape cannot be supplied as a long sheet material suitable for a production line for producing sheet products. In addition, a cellulosic sponge formed in a cross shape has been developed, but there is a certain limit to thinning the sponge, and it is necessary to form a thin sheet of about 5 mm in thickness. This is a limit, and even if the sheet is wound into a roll as a raw material for obtaining a sheet product, it can only be wound about 50 m and cannot be a long sheet suitable for the production line. For this reason, although having high water absorption, the cellulose sponge could not be adopted as an application such as a water-absorbing sheet used for the above-mentioned wetting operation.

In view of the above circumstances, it is an object of the present invention to provide a thin sheet which is easy to dispose, such as a conventional paper towel, to have high water absorption performance, and to obtain a sheet having high water absorption and easy to use. With the goal.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in consideration of the above problems, and a cellulose sponge chip obtained by pulverizing a cellulose sponge made of foamed pulp is provided.
An object of the present invention is to provide a highly water-absorbent sheet characterized by being embedded in a fibrous tissue sheet to solve the above problems. The highly water-absorbent sheet of another invention is characterized in that a cellulose sponge chip obtained by pulverizing a cellulose sponge made of a foamed pulp is integrated into a sheet via an adhesive. The highly water-absorbent sheet according to another aspect of the present invention is characterized in that a cellulose sponge chip obtained by pulverizing a cellulose sponge made of foamed pulp and a fiber tissue sheet are laminated. This is provided to solve the above problem. And the above-mentioned cellulose sponge chip can be a pulverized product obtained by pulverizing a cellulosic sponge made of a foamed material of non-wood pulp composed of low-vegetable plant fiber, and the above-mentioned cellulose sponge chip is It is possible to make a pulverized material obtained by pulverizing a cellulosic sponge composed of a foamed non-wood pulp composed of medicinal plant cellulose, and the cellulose sponge chip is composed of a foamed pulp having copper chlorophyll. It is possible to make a cellulosic sponge into a crushed product.

[0005] Further, as a method for producing a super absorbent sheet,
The pulp solution is mixed with a cellulose sponge chip obtained by pulverizing a cellulosic sponge consisting of a foamed pulp and an adhesive, and a sheet is prepared from the mixture, into which the cellulose sponge chip is embedded, and the sheet is dewatered. The object of the present invention is to provide a method for producing a super absorbent sheet characterized by drying by drying. Further, as another method for producing a super absorbent sheet, in water, a cellulose sponge chip obtained by pulverizing a cellulose sponge made of foamed pulp and an adhesive are mixed, and an extract comprising the cellulose sponge chip is prepared from the mixed solution. A method for producing a superabsorbent sheet, which is characterized in that a sheet is formed, and the sheet is dehydrated and dried. The object of the present invention is to provide a method for producing the superabsorbent sheet and to solve the above problems. In the above invention, the cellulosic sponge chip can be a pulverized product obtained by pulverizing a cellulosic sponge made of a foamed non-wood pulp composed of low-vegetable plant fiber. Further, a pulverized product obtained by pulverizing a cellulosic sponge made of a foamed product of non-wood pulp composed of herbaceous plant fiber can be obtained. And the above-mentioned cellulose sponge chip can be made into a pulverized product obtained by pulverizing a cellulose sponge made of foamed pulp having copper chlorophyll.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the embodiments shown in FIGS. In the figure, reference numeral 1 denotes a superabsorbent sheet. As shown in FIG. 2, the superabsorbent sheet 1 has a thickness obtained by mixing a fiber tissue sheet 2 made of plant fiber or synthetic fiber with a cellulose sponge chip 3. It is a small thin shape. That is, the super-water-absorbent sheet 1 is obtained by squeezing the cellulosic sponge chips 3 and compressing them. The buried cellulose sponge chip 3 is a crushed material obtained by crushing a cellulosic sponge made of a non-wood pulp foam made of low-vegetable vegetable fiber into chips having a size of about 5 to 15 mm. It is a material having higher water absorption and water retention than ordinary paper even if it has a different shape. And
Since the cellulosic sponge chips 3 are laid, the superabsorbent sheet 1 has high water absorption and water retention. The water absorption and the water retention of the superabsorbent sheet 1 are adjusted by changing the mixing ratio of the cellulose sponge chips 3.

The cellulosic sponge, which is the raw material of the cellulosic sponge chip 3, is made of foamed non-wood pulp composed of low-vegetable plant fiber as described above. Pulp (vegetable cellulose) is obtained by dissolving at least one of stem, leaf, and seed foreskins as a material. Then, after treating this pulp with a sodium hydroxide solution, a treatment is performed by adding a chemical such as carbon disulfide and soda to obtain viscose (which is in a somewhat viscous liquid state). I have. This viscose and a foaming agent made of sodium sulfite and the like are mixed to foam and coagulate. Thereafter, the foam obtained by coagulation is washed with a softener, a bleeding agent, a weakly acidic solution, or the like, whereby the above-mentioned non-woody cellulosic sponge as a raw material is obtained. Dehydration and drying are performed as a post-treatment, and the cellulose sponge thus obtained is pulverized into chips of the above size using, for example, a pulverizer. In addition, you may make it use the foamed material of a wooden pulp as a cellulose sponge.

FIGS. 3 and 4 show the superabsorbent sheet 1 in the second example. In the superabsorbent sheet 1, the cellulosic sponge chips 3 are integrated into a sheet through an adhesive selected from polyvinyl alcohol (PVA), starch, and various other synthetic resins, and are compressed to a required thickness. It is formed in a thin shape. The adhesive is not only located at the boundary where the cellulose sponge chips 3 overlap, but also enters the inside of the chips 3 and securely binds the chips to such an extent that the flexibility of the superabsorbent sheet 1 is not impaired. Things. The synthetic resin used as the adhesive does not generate toxic substances even when incinerated.

FIGS. 5 and 6 show a highly water-absorbent sheet 1 in a third example. The superabsorbent sheet 1 is obtained by arranging the fibrous tissue sheets 2 made of plant fibers, synthetic fibers, and the like vertically and arranging the cellulosic sponge chips 3 between them, and laminating and integrating them. And thinned. Since the cellulose sponge chips 3 located between the fiber tissue sheets 2 are constrained by the fiber tissue sheets 2, it is not always necessary to bind the chips to each other. You may.

As the fibrous tissue sheet 2 in the superabsorbent sheets 1 of the first and third examples, vegetable fibrous material (pulp), which is a raw material of ordinary paper, can be used. Polyvinyl alcohol (PVA) fiber, which is a synthetic resin fiber that does not generate harmful substances during incineration,
Polyethylene (PE) fiber, polypropylene (PP) fiber, polyethylene terephthalate (PET) fiber, and the like can be selected. By selecting this material, the highly water-absorbent sheet 1 itself can be made of water-insoluble paper or wash-resistant paper. it can.

[0011] As described above, the cellulose sponge chip is made of plant fiber, and since the plant fiber itself has an antibacterial property, the cellulose sponge chip is also provided with an antibacterial property. A highly water-absorbent sheet using a cellulose sponge chip has an antibacterial property. Further, in the cellulosic sponge chip, a herb is used in place of the low-vegetable plant to obtain a non-wood pulp composed of plant fiber of the herb, and a cellulosic sponge made of a foam of the non-wood pulp May be used as a crushed product. In this case, as a herb that can be used in this case, for example, Kumabasa, sorghum, dokudami, etc. can act, and it becomes a highly water-absorbent sheet that exerts the medicinal effect of the herb in addition to the antibacterial property of the above-mentioned plant fibrin itself.

The above-mentioned cellulose sponge chip may be obtained by obtaining an antibacterial pulp having copper chlorophyll and pulverizing a cellulosic sponge made of a foamed product of this antibacterial pulp. The antibacterial pulp is one in which the plant chlorophyll contains copper chlorophyll by converting magnesium chlorophyll contained in the green leaves of the low grasses into copper chlorophyll, and exhibits excellent antibacterial properties. Because it contains copper chlorophyll, this antibacterial pulp is foamed and then pulverized, that is, this cellulose sponge chip has excellent antibacterial properties by adding the antibacterial properties of the plant cellulose itself Will be shown. As the antibacterial pulp containing copper chlorophyll, specifically, magnesium chlorophyll contained in green leaves of vegetation is converted into copper chlorophyll, which is used in pharmaceuticals such as copper chlorophyllin sodium salt and copper chlorophyllin potassium salt Using the remaining residue
This residue is treated with alkali to form pulp. As a raw material of this antibacterial pulp, any plant can be used as long as it contains chlorophyll, and Kumasasa or wild grass can be used as a raw material, so that it can be supplied in large quantities and can be manufactured at low cost. Logging does not cause deforestation problems. In addition, the cellulose sponge chip is obtained by pulverizing a cellulosic sponge obtained by adding an antibacterial pulp having copper chlorophyll to a non-wood pulp composed of woody pulp or low-vegetable plant fibrous material and the above-mentioned copper chlorophyll. There may be. Even in such a case, the cellulose sponge chip itself exhibits antibacterial properties because it contains copper chlorophyll.

[0013] In the cellulose sponge obtained by including the antibacterial pulp as a part of the pulp, the content of the antibacterial pulp is less than 0.001% by weight of copper chlorophyll based on the total amount of the cellulose sponge. The initial effect is not obtained, and the effect does not increase even if it is more than 0.01% by weight, so that the amount of copper chlorophyll is in the range of 0.001 to 0.01% by weight based on the total amount of the cellulose sponge. And preferably 0.0
More preferably, it is in the range of 03 to 0.05% by weight. In addition, by including copper chlorophyll as a part of plant fibrin, copper chlorophyll exhibits excellent antibacterial properties so that the copper chlorophyll does not easily detach from the cellulose sponge, and at the same time, its antibacterial properties Will be exhibited for a long time.

In order to obtain the superabsorbent sheet 1 in the first example, as shown in FIG. 7, first, a plant fiber for constituting the fibrous tissue sheet is swollen by thoroughly tapping it in water. At the same time, the plant fiber itself is supple while being loosened (beating step A). When the above-mentioned synthetic fibers are used to obtain a fibrous tissue sheet, the beating step is unnecessary. The plant fibrin after the beating step is dissolved and diluted 100 times or more by weight. In the case of a synthetic fiber, the synthetic fiber is diluted with a required solution to 100% by weight.
It is diluted by a factor of 2 or more to obtain a 1% solution, that is, a pulp solution (pulp forming step B). Next, the pulp solution, the cellulose sponge chips, and an adhesive selected from polyvinyl alcohol, starch, other various synthetic resins, and the like are mixed well so that each material is uniformly dispersed ( Mixing step C). The pulp solution containing the cellulose sponge chips after the mixing step is sieved with a wire mesh to obtain a sheet having a uniform thickness (screwing step D). Then, the paper sheet obtained in the squeezing step is dewatered to form a wet sheet (dewatering step E), and the wet sheet is further squeezed and dried to reduce the final moisture to several percent (drying step F). ) And then compressing it (compression step G) to obtain a super absorbent sheet. Note that the compression step, which is the final step, is not always required.

When the superabsorbent sheet 1 in the second example is obtained, the above-described beating step and pulp forming step are not required.
Beginning with the mixing step of mixing the cellulose sponge chips and the adhesive in water, thereafter, the cellulose sponge chips are sieved from the mixture in a wire mesh to obtain a sheet having a substantially uniform thickness in the same manner as described above (the squeezing step). ). Then, the papermaking sheet obtained in the making step is dewatered to make a wet sheet (dewatering step), and the wet sheet is further squeezed and dried to reduce the final water content to several percent (drying step). By compressing this (compression step), a highly water-absorbent sheet is obtained. In the superabsorbent sheet of the third example, the fiber tissue sheet sandwiching the cellulose sponge chips is formed in advance, and the cellulose sponge chips are continuously provided between the continuously supplied fiber tissue sheets. The highly water-absorbent sheet in a sandwiched form is obtained by supplying the compressed water and compressing and integrating it.

[0016]

According to the present invention described above, the highly water-absorbent sheet is a sheet having the same thin shape as a conventional paper towel and the like, but having much higher water absorption and water retention than the conventional one. This makes it possible to reliably remove water when wiping hands with this super absorbent sheet or when wiping water or the like from a wet object. Furthermore, since it is a thin product, it is easy to use and its storage management is simple. Cellulose sponge chips themselves are made of natural materials, and the fibrous tissue used to make them is made of vegetable fibers or synthetic fibers that do not emit toxic substances such as chlorine compounds during incineration. And the super absorbent sheet is easy to dispose of.

Since the superabsorbent sheet has good water absorbency and water retention, it can be used as a mat to be laid on a bed. That is, mats conventionally laid on beds, especially mats used in hospitals, are those having a low moisture absorption limit made of cloth,
It is difficult for the patient to absorb the sweat that the patient touched for a long time,
The feel is also likely to change early, but the high water absorption sheet has a cellulosic sponge chip, which guarantees high water absorption and water retention, and is much better than conventional fabrics. It has high water absorption and water retention. And since moisture such as sweat is taken in between the fibers in the chip, changes due to moisture absorption are unlikely to occur on the surface layer, and the highly water-absorbent sheet has a very large number of fine ventilation parts to achieve high air permeability. This makes it possible to maintain good touch for a long period of time, and to provide a good sheet for bedding and medical beds. further,
Since the cellulosic sponge chip itself has an antibacterial property, it has an effect of suppressing the growth of bacteria even when used for a long time.

Further, according to the manufacturing method described above, a cellulosic sponge, which has a high water absorbency and water retention and cannot be developed as a sheet because it is produced in a block shape, is formed into chips. Since it is used, it is possible to continuously produce a long sheet utilizing the advantages of the cellulose sponge, and it is possible to efficiently produce a highly water-absorbent sheet having the cellulose sponge. Further, since the structure is simple, a highly water-absorbent sheet can be obtained without requiring a large amount of equipment cost.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one example of a superabsorbent sheet according to the present invention.

FIG. 2 is an explanatory diagram showing an example in cross section.

FIG. 3 is an explanatory diagram showing a second example.

FIG. 4 is an explanatory view showing a second example in cross section.

FIG. 5 is an explanatory diagram showing a third example.

FIG. 6 is an explanatory diagram showing a third example in cross section.

FIG. 7 is an explanatory view schematically showing a manufacturing process of the superabsorbent sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Super absorbent sheet 2 ... Fiber tissue sheet 3 ... Cellulose sponge chip A ... Beating process B ... Pulp forming process C ... Mixing process D ... Screwing process E ... Dehydration process F ... Drying process G ... Compression process

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koji Sasaya 5-2, Kamanosawa, Utetsu, Sanmaya-mura, Higashitsugaru-gun, Aomori (72) Inventor Shigeji Inaoka 1137, Numazu-Ichihara, Shizuoka (56) References Hei 7-316202 (JP, A) JP-A-58-76434 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D21H 21/22, 17/02

Claims (11)

(57) [Claims] A highly water-absorbent sheet characterized in that a cellulose sponge chip obtained by pulverizing a cellulose sponge made of foamed pulp is embedded in a fiber tissue sheet. 2. A highly water-absorbent sheet wherein a cellulose sponge chip obtained by pulverizing a cellulose sponge made of a foamed pulp is integrated into a sheet via an adhesive. 3. A highly water-absorbent sheet wherein a cellulose sponge chip obtained by pulverizing a cellulose sponge made of a foamed pulp and a fiber tissue sheet are laminated. 4. The cellulosic sponge chip according to claim 1, wherein the cellulosic sponge chip is a pulverized product obtained by pulverizing a cellulosic sponge made of foamed non-wood pulp composed of low-vegetable plant fiber. The superabsorbent sheet according to the above. 5. The cellulosic sponge chip is a pulverized product obtained by pulverizing a cellulosic sponge made of foamed non-wood pulp composed of medicinal plant fiber.
4. The superabsorbent sheet according to any one of items 1 to 3. 6. The superabsorbent sheet according to claim 1, wherein the cellulose sponge chips are pulverized cellulose sponges made of foamed pulp having copper chlorophyll. 7. A pulp solution is mixed with a cellulosic sponge chip obtained by pulverizing a cellulosic sponge made of foamed pulp and an adhesive, and a sheet is prepared from the liquid mixture, into which the cellulosic sponge chips are embedded. A method for producing a highly water-absorbent sheet, comprising dehydrating and drying a sheet-formed sheet. 8. A cellulose sponge chip obtained by pulverizing a cellulosic sponge made of foamed pulp and water and an adhesive are mixed in water, and a sheet made of the cellulose sponge chip is made from the mixed solution, and the sheet is dewatered. And producing the superabsorbent sheet. 9. The highly water-absorbent material according to claim 7, wherein the cellulose sponge chip is a pulverized product obtained by pulverizing a cellulose sponge made of a foamed non-wood pulp composed of low-vegetable plant fiber. Sheet manufacturing method. 10. The high-grade sponge according to claim 7, wherein the cellulosic sponge chip is a pulverized product obtained by pulverizing a cellulosic sponge made of a foamed non-wood pulp composed of medicinal plant fiber. A method for producing a water absorbent sheet. 11. The method for producing a super absorbent sheet according to claim 7, wherein the cellulose sponge chip is a pulverized product obtained by pulverizing a cellulose sponge made of foamed pulp having copper chlorophyll.