JP4621469B2 - Adsorption sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to an adsorption sheet and a method for producing the same.

Japanese Examined Patent Publication No. 56-49608 JP 2002-69895 A Japanese Patent Laid-Open No. 2003-118024 Japanese Patent Laid-Open No. 10-314580

  In Patent Document 1, when an activated carbon sheet is produced by a wet papermaking method, 0.0 to 0.5% by weight of polyethyleneimine and 10 to 95% by weight of activated carbon are added to a dispersion of natural cellulose fibers in water. A manufacturing method for adding is disclosed. In this case, the ratio of activated carbon is about 5 to 48% by weight of the entire sheet. Also, it is disclosed that an aggregating agent of activated carbon such as natural rubber latex or synthetic rubber latex is added in order to sufficiently retain the activated carbon between the fibers. In Example 1, it is disclosed that the sheet is manufactured by hand-drawing with a sheet machine.

  Patent Document 2 discloses a deodorizing charcoal sheet comprising a Japanese paper main body containing bamboo charcoal fine powder and a bamboo vinegar component fixed in a sprayed state on at least one surface of the Japanese paper main body. Further, a manufacturing method is disclosed in which bamboo paper charcoal fine powder is mixed with Japanese paper pulp, a required amount of liquid binder is mixed, Japanese paper is spread using a Japanese paper-making frame, and the obtained Japanese paper is peeled off and dried. Bamboo charcoal fine powder is preferably 100 mesh or more and within 299 mesh, and the ratio of mixing bamboo charcoal fine powder to the raw material is 30% to 40% (Japanese paper pulp: bamboo charcoal fine powder = 7: 3 or 6: 4, etc.) It is also disclosed that the amount of binder (liquid) as a water-soluble paste is 15 to 25%. Moreover, it is disclosed that the content of the fine powder of bamboo charcoal in the Japanese paper body is desirably 40 to 70 g / 1 square meter.

On the other hand, in Patent Document 3, a dispersion liquid in which cellulose fibers such as waste paper and pulp are beaten and dissolved in water is spun by a wet paper making method to form a belt-like paper, and then formed from wood, bamboo, or the like. There is disclosed a laminated sheet in which a fine powder of porous carbide is uniformly sprayed, another belt-like paper formed by a wet papermaking method is further stacked thereon, and the whole is passed through a pressure roll and a drying roll. The laminated sheets are bonded together with an adhesive or the like. Patent Document 3 also discloses that papermaking containing pulverized coal formed from a solution obtained by mixing and stirring porous fine powder into cellulose fibers is used as an intermediate layer. These are three-layer laminate sheets in which bamboo charcoal fine paper or papermaking containing pulverized coal is sandwiched between paper surface layers. An appropriate amount is about ² g / m ^{2 in the} case of sandwiching fine powder, and about 10 g / m ^{2 in} the case of papermaking with pulverized coal.

  Patent Document 4 discloses a sheet material and a board material having a three-layer structure in which a mixture of bamboo charcoal powder and glue is sandwiched between Japanese paper and heated and compressed.

  Since the activated carbon sheet of Patent Document 1 is 5 to 48% by weight of the activated carbon, the effect of the activated carbon is not sufficient. Also in the case of the charcoal sheet of Patent Document 2, bamboo charcoal fine powder is about 30 to 40% by weight, and the deodorizing effect of bamboo charcoal is not sufficient. On the other hand, in the case of Patent Document 3 and Patent Document 4, since a paper layer is formed on the surface, there is an advantage that printing is possible, but since the content of bamboo charcoal is small and not exposed on the surface, the adsorption action The deodorizing action and purification action of bamboo charcoal etc. become low.

  An object of the present invention is to provide an adsorption sheet that has a high adsorption action, is easy to recycle and discard, and has a low environmental load. Furthermore, it is a technical object of the present invention to provide a method for producing an adsorbing sheet that can efficiently produce the adsorbing sheet and that can easily produce various thicknesses.

The adsorbing sheet of the present invention has a weight of 1 to 3% of the total weight of the porous particles obtained by pulverizing bamboo charcoal 60 to 90 wt%, the vegetable pulp 10 to 40 wt%, and the porous particles and the vegetable pulp. A large number of papermaking is performed by rotating a cylindrical wire net of a round net paper machine with a binder mixed in water and negative pressure inside the mixed liquid, and making paper on the outer surface of the metal net multiple times. By forming this layer, the porous particles are held inside each paper-making layer and between the upper and lower paper-making layers (claim 1).
The second aspect of the adsorbing sheet of the present invention is a mixture of porous particles 60 to 90 wt% pulverized bamboo charcoal, 10 to 40 wt% vegetable pulp, and 5 g of binder per liter of water used in water. By rotating the wire net of a round net paper machine with a negative pressure inside the mixed liquid and repeating the operation of making a plurality of times on the outer surface of the metal net, a number of paper making layers are formed. The porous particles are held in the inner layer and between the upper and lower papermaking layers (claim 2).
In these adsorbent sheets, those having a surface electrical resistance before pulverization of the bamboo charcoal of 50 Ω / cm or less are preferred (Claim 3). Further, it is preferable that the binder is natural rubber latex. For example, the suction sheet has a thickness of about 0.5 to 10 mm.

The production method of the adsorbing sheet of the present invention is as follows: porous charcoal 60 to 90 wt% pulverized bamboo charcoal, vegetable pulp 10 to 30 wt%, and 1 to 3% of the total weight of the porous particles and vegetable pulp A binder of 5 g per liter of water or a binder of 5 g per 1 liter of water to be used is mixed in water, and the wire net of a round net paper machine having a negative pressure inside is rotated in the mixed solution, and the outer surface of the metal net is rotated. A plurality of papermaking operations are repeated to form a number of papermaking layers and dried (claim 5).

Since the adsorbing sheet (Claim 1) and the second aspect (Claim 2) of the present invention contain a large amount of porous particles obtained by pulverizing bamboo charcoal, such as 60 to 90 wt%, compared to conventional ones. Adsorption is high. Therefore, the deodorizing action and the air purification action are high. Further, since the bamboo charcoal porous particles are retained inside and between the papermaking layers, a large amount of porous particles can be contained even if there is little binder. Moreover, when there are many bamboo vinegar components, an antibacterial action or a bactericidal action is also obtained. Furthermore, since the materials are mainly bamboo charcoal and vegetable pulp and no adhesive is used, the fine pores of the porous particles obtained by pulverization are not easily clogged, and the adsorbing action is high. Furthermore, since a natural material is a main component, it can be discarded as it is, and it can also be reused by being sprayed into the soil as a soil improvement material for a field or the like.

In such a suction sheet, since the operation of the paper is being performed multiple times, it does not lose its flexibility even if the thickness of the sheet is in the 0.5 to 10 mm, and since a relatively thick paper It can be used for various purposes such as ceilings and wall foundations. Further, since the papermaking operation is performed a plurality of times, it can be used by being peeled thinly or can be used as it is thick. Furthermore, it is easy to subdivide by thinly peeling at the time of disposal. Therefore, it can be easily reused as a soil conditioner for fields.

  When the surface electrical resistance before pulverization of the bamboo charcoal is 50 Ω / cm or less (Claim 3), the carbon purity of the bamboo charcoal is high, and even the powder after pulverization has few impurities such as tar. Therefore, the fine pores of the pulverized bamboo charcoal porous particles are less likely to be clogged, and the adsorption action is even higher.

  When the binder is a natural rubber latex (Claim 4), the entire sheet can be made of a natural material (plant material), so that the environmental load at the time of disposal is further reduced.

  According to the manufacturing method of the suction sheet of the present invention (Claim 5), the above-mentioned suction sheet can be efficiently manufactured.

  Next, embodiments of the suction sheet and the manufacturing method thereof according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the adsorbing sheet of the present invention, FIG. 2 is a cross-sectional view of the adsorbing sheet, FIG. 3 is a process diagram showing an embodiment of the method for producing porous particles used in the present invention, and FIG. 4 is a process diagram showing an embodiment of the method for producing an adsorbing sheet of the present invention.

  An adsorbing sheet 10 shown in FIG. 1 is a sheet mainly composed of porous particles 11 obtained by pulverizing bamboo charcoal and vegetable pulp 12, and is in a laminated state of a plurality of papermaking layers 13 as shown in FIG. Yes. The adsorption sheet 10 also includes a small amount of binder. The ratio of the porous particles 11 is 60 to 90 wt% of the whole, and particularly preferably about 75 to 85 wt%. The proportion of the vegetable pulp 12 is the remaining 40 to 10 wt%, preferably about 15 to 25 wt%. The binder to be used is, for example, about 1 to 3% of the total weight of the porous particles 11 and the vegetable pulp 12, but since it is dispersed in the water when making paper, only a trace amount remains in the obtained adsorption sheet 10. It is. In addition, the code | symbol 14 of FIG. 1 is the fiber end of the vegetable pulp 12 which appears when the adsorption sheet 10 is torn.

  As shown in FIG. 3, the porous particles 11 are made of bamboo charcoal and pulverized to an average particle size of about 10 to 500 μm by a pulverizer or fine pulverizer. When the average particle diameter is larger than 500 μm, the porous particles 11 are difficult to adhere to the vegetable pulp 12. Therefore, the total amount of adhesion tends to be reduced. On the contrary, when the average particle size is smaller than 10 μm, it adheres sufficiently to the surface of the vegetable pulp 12, but it adheres thinly, and the amount of porous particles attached tends to decrease as a whole.

  As the raw bamboo material (see reference numeral 15 in the first step S1 in FIG. 3), those having a large number of fine holes, such as 孟 宗 bamboo, true bamboo, and light bamboo, are preferred, and bamboo having a growth age of 3 to 5 years is particularly preferable. preferable. Such raw bamboo is dried and halved as in the first step S1, and then steamed and burned at 700 to 900 ° C. in the baking furnace 16 for charcoal (second step S2). The firing path 16 is provided with a regulating valve 17 at the air intake and is ignited by a gas burner 18. When the carbonization process is completed, the obtained bamboo charcoal is brushed and washed (third step S3). And as mentioned above, it grind | pulverizes with a fine grinder etc. (4th step S4).

  In addition, when baking with the baking furnace 16, a temperature will rise first, and temperature will once stabilize at about 90-110 degreeC. And if baking is further continued, temperature will become constant again at about 500-700 degreeC. The reason why the temperature changes stepwise in this way is considered to be that water is evaporated from the raw bamboo in the first 90 to 110 ° C. stage, and the bamboo vinegar is extracted, and the next 500 to 700 ° C. stage. Then, it is considered that tar is extracted and evaporated. Therefore, the final temperature of charcoal baking is preferably at least 750 ° C. or higher.

  The time for charcoal baking varies depending on the weight of the raw bamboo 15 to be used, but is usually about 12 to 18 hours, more preferably about 14 to 15 hours. Inside the firing furnace 16, carbon monoxide is generated during the carbonization of the raw bamboo 15, and the carbon monoxide is further burned and changed to carbon dioxide. Therefore, it is necessary to supply air sufficiently. However, in the final process, the oxygen concentration is kept low to prevent ashing.

  By baking at a high temperature as described above, tar, bamboo vinegar, and the like are separated, and bamboo charcoal with high carbon purity is obtained. In this case, the electric resistance of the surface of bamboo charcoal is preferably 50 Ω / cm or less, particularly preferably 10 Ω / cm or less. When the electrical resistance is higher than that, the purity is low and there are many impurities such as tar, so that the fine pores of the porous particles are clogged and the adsorption action is lowered. For example, as shown by an imaginary line 19 in the first step S1 of FIG. 3, the electric resistance of the bamboo charcoal is measured by placing two electrode bars of the tester on the surface of the bamboo charcoal at intervals of several centimeters. Incidentally, no current is supplied with the raw bamboo 15 shown in FIG.

  The vegetable pulp 12 is preferably bleached pulp obtained from conifers such as rice pine and cedar used for ordinary papermaking. A pulp having an average length of about 2 to 3 mm and an average thickness of about 0.1 to 0.2 mm is used. In addition, Japanese paper pulp such as kouzo, mitsumata, and ganpi may be used. Furthermore, bamboo pulp obtained from the various bamboos described above can also be used.

The binder is preferably a plant-derived binder such as natural rubber latex or corn starch. Natural rubber vulcanized latex can also be used. The amount of the binder used varies depending on the ratio of the porous particles and the vegetable pulp and the shape maintaining property of the sheet to be obtained as described above. For example, the amount of the binder used is 1 of the total weight of the porous particles 11 and the vegetable pulp 12. about 3%, or about 5g to 1 liter of water to be used when Extract paper.

  The thickness of the adsorbing sheet 10 is usually about 0.5 to 10 mm, but it may be 0.5 mm or less, and paper can be made to 10 mm or more. However, a sheet of about 0.5 to 10 mm, particularly a sheet of about 3 to 5 mm is preferable because it is easy to handle. With such a thickness, it is easy to cut into a predetermined shape with a press, and it is less likely to break after cutting. Moreover, it can be easily joined to the surface of a base material such as wood with a stapler (stapler) or a set pin. Although bonding with an adhesive is possible, considering the case of recycling, it is preferable to use a bonding means that is easy to separate. As the adhesive, it is preferable to use plant-derived paste, such as starch paste.

Next, a manufacturing method of the suction sheet 10 will be described with reference to FIG. First, the porous fine particles 11, the vegetable pulp 12 and the binder 20 are prepared (fifth step S5). Next, these materials are put in a water tank 22 of the paper machine 21 at a predetermined weight ratio, and mixed and stirred (second step S6). Papermaking is performed a plurality of times to form a laminated state having a thickness of 0.5 to 10 mm as a whole (third step S3). In that case, the thickness of one papermaking layer (reference numeral 13 in FIG. 2) is about 10 to 50 g / m ² in terms of dry weight.

  The paper making process of laminating such thin paper making layers is repeated several tens of times, preferably about 300 to 500 times. Thereby, the adsorption sheet 10 having a multilayer structure as shown in FIG. 2 is obtained. In the adsorption sheet 10, the porous particles 11 are held not only inside the paper making layer 13 but also between the upper and lower paper making layers 13. Therefore, even when the proportion of the porous fine particles 11 is as high as 60 to 90%, the particles are stably supported.

  In order to efficiently repeat such many times of paper making, it is preferable to use a round net paper machine. For example, as shown in the sixth step S6 of FIG. 3, the round net paper machine has a water tank 22, a cylindrical wire mesh 23 supported in the water tank so as to be rotatable about a horizontal axis, and a negative pressure inside the wire mesh. And a suction means 24 such as a pump. Therefore, a long sheet cannot be formed, but a thin paper layer can be formed many times on the surface of the wire mesh 23 by rotating the inside of the wire mesh 23 while applying a negative pressure. Therefore, the thickness can be set relatively arbitrarily.

A cylindrical (endless) sheet 25 is formed around the wire mesh 23 by the paper making / laminating process (sixth step S6). Thereafter, pulling the sheet 2 5 obtained with wire mesh 23 us to obtain a rectangular sheet 25 scored in one place (fourth step S4). The obtained sheet 25 is passed through a dryer in the seventh step S7 and dried. Thereby, the suction sheet 10 as shown in FIG. 1 and FIG. 4 is obtained. When sufficiently dried, even if the adsorbing sheets 10 are stacked, the fibers are not entangled and the sheets do not stick together.

  As shown in FIG. 2, the obtained adsorbing sheet 10 has a laminated form in which a number of thin paper-like or cotton-like paper-making layers 13 are stacked. And since there is little usage-amount of a binder, it is flexible, its tension (weakness) is weak, and it has the appearance which crushed cotton rather than paper. Even a thickness of several millimeters is easily bent, and the thin suction sheet 10 of 1 mm or less can be easily torn off. When it is torn off, as shown in FIG. 1, the end 14 of the fiber of the vegetable pulp appears at the end edge. Also, since the amount of binder used is small and the amount of porous particles 11 used is large, the bonding force between the layers is also weak, and as shown by the imaginary line in FIG. 2, if the surface layer 13a is picked and pulled, it can be easily peeled off. Can do.

  Furthermore, in any case, when the film is peeled off or torn, the porous particles 11 loosely bonded with the binder and the vegetable pulp 12 fibers fall apart. Further, when the torn pieces are further loosened, most of the porous particles 11 are separated, and a lump of cotton-like fibers having the porous particles 11 thinly adhered to the surface remains. As described above, since the suction sheet 10 itself cannot be expected to have any strength, it is used by being attached to another base material such as wood or a wire mesh.

  Although the suction sheet 10 formed as described above can be rolled up and sold, it is difficult to obtain a long sheet with a round net paper machine, and is usually sold as a rectangular sheet. . It can also be cut into a predetermined shape and used as a part. When selling as a roll sheet or a regular sheet, for example, it is attached to a base material such as a flooring material, a ceiling material, or a wall material of a building. As a result, it is possible to adsorb formaldehyde separated from the adhesive and other chemical substances that cause sick house. Examples of the base material on which the adsorption sheet is attached include wood, particle board, and gypsum board.

  Moreover, when cut | disconnecting to a defined shape, it can be pinched | interposed between metal-mesh, and can be used as a filter of an air conditioner or a water purifier, or can be utilized as an inner layer material of furniture or a kitchen product. Furthermore, it can be used to purify water by sinking in a bathtub while sandwiched between synthetic resin and stainless steel nets. In any case, an antibacterial action or a bactericidal action can be exhibited in addition to the adsorption action of bamboo charcoal. Further, when discarded, it can be reused as a soil conditioner by being buried in a field or after being finely cut and then sprayed in the field.

  Further, the adsorbing sheet 10 can be used as it is, or the adsorbing sheets 10 can be laminated and used, or a sheet having high air permeability and liquid permeability, for example, paper can be laminated to form a laminated sheet. However, it is preferable to use a natural material such as paper made of vegetable pulp for the other sheets to be laminated, and also use a natural material or vegetable material such as vegetable glue for the adhesive. Moreover, antibacterial or sterilizing effect can be increased by spraying distilled bamboo vinegar or the like on the adsorbing sheet 10.

It is a perspective view which shows one Embodiment of the suction sheet of this invention. It is sectional drawing of the adsorption sheet of FIG. It is process drawing which shows one Embodiment of the manufacturing method of the porous particle used for this invention. It is process drawing which shows one Embodiment of the manufacturing method of the adsorption sheet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Adsorption sheet 11 Porous particle 12 Vegetable pulp 13 Papermaking layer 14 End of fiber 15 Raw bamboo 16 Baking furnace 17 Regulating valve 18 Gas burner 19 Electrode rod 20 Binder 21 Paper machine 22 Water tank 23 Wire mesh 24 Suction means 25 Sheet

Claims (5)

Porous particles 60 to 90 wt% pulverized bamboo charcoal, vegetable pulp 10 to 40 wt%, and a binder having a weight of 1 to 3% of the total weight of the porous particles and the vegetable pulp are mixed in water. ,
By rotating the cylindrical wire net of the round net paper machine with the negative pressure inside the mixed liquid and repeating the operation of making paper multiple times on the outer surface of the metal net, a large number of paper layers are formed, An adsorption sheet in which the porous particles are held inside each papermaking layer and between the upper and lower papermaking layers. 60 to 90 wt% of porous particles obtained by pulverizing bamboo charcoal, 10 to 40 wt% of vegetable pulp, and 5 g of binder per liter of water used are mixed in water,
By rotating the cylindrical wire net of the round net paper machine with the negative pressure inside the mixed liquid and repeating the operation of making paper multiple times on the outer surface of the metal net, a large number of paper layers are formed, An adsorption sheet in which the porous particles are held inside each papermaking layer and between the upper and lower papermaking layers. The adsorption sheet according to claim 1 or 2 whose surface electric resistance before crushing said bamboo charcoal is 50 ohms / cm. The adsorption sheet according to claim 1 or 2, wherein the binder is natural rubber latex. Binder with a weight of 1 to 3% of the combined weight of the porous particles and vegetable pulp, or 60 to 90 wt% of porous particles obtained by pulverizing bamboo charcoal, 10 to 30 wt% of vegetable pulp, and 1 liter of water to be used Per 5 g of binder with water,
Rotate the cylindrical wire mesh of a round net paper machine with negative pressure inside the mixed liquid, and repeat the operation of making paper multiple times on the outer surface of the wire mesh to form a number of paper making layers,
A method for producing an adsorbent sheet to be dried.