JP2008173834A - Humidity control vegetable fiber board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a humidity control vegetable fiber board having high humidity control property and excellent machinability. <P>SOLUTION: The humidity control vegetable fiber board A is formed by lignocellulose fiber 1 obtained from vegetable bonded with each other by a binder 2. The humidity control material 3 is held in the inside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a humidity-adjustable vegetable fiber board used as a housing interior material or the like.

  With the spread of highly airtight houses, interest in indoor environments, especially moisture, is increasing. There is a limit to the amount of water vapor contained in the air, and the amount increases as the temperature increases, and decreases as the temperature decreases. If the air containing a lot of water vapor is cooled to a cold one or the room temperature is greatly lowered in a place where the temperature is high, the water vapor in the air returns to the water and causes condensation.

  Places with high humidity, such as water-consuming rooms and places with poor airflow, are likely to cause condensation. In order to prevent dew condensation, ventilation is important, and it is effective to use windows, walls, etc. as a highly heat-insulating material.

  Currently, cloth, wood boards, and inorganic boards that are often used as house interior materials do not have high humidity control (moisture absorption and desorption). Excessive moisture condenses, leading to the growth of microorganisms such as mold, and the indoor environment. Will worsen.

  Therefore, interest in materials with high humidity control such as diatomaceous earth, charcoal, and zeolite is increasing. If the interior is finished with these moisture-absorbing materials, moisture can be absorbed when there is a lot of moisture, and moisture can be released when there is little moisture, and condensation on the surface such as walls can be suppressed. .

  Such a highly moisture-controllable material does not have adhesiveness by itself, and therefore, it is common to apply an inorganic or resin binder in a wet manner. However, since the substrate treatment, undercoating, and overcoating are complicated in the wet process, there is a demand for a board that has humidity control only by being applied. For this reason, as described in Japanese Patent No. 2651593 (Patent Document 1) and the like, there is a board or tile made of a humidity conditioning material obtained by mixing a highly humidity-controllable material and a binder. However, when a highly humidity-controllable material is exposed on the surface such as a board or wet type, there is a problem that the material is weak and the humidity-controllable material is peeled off. There was a problem that the humidity control was reduced.

  On the other hand, when a highly humidity-controllable material is contained inside the board, not the surface of the board, problems such as peeling will disappear, but it will be difficult for moisture to reach the highly humidity-controllable material inside the board. Stayed in effect.

  Further, as a part where condensation is likely to occur in a house or the like, there is a close-in, etc., and usually a wood-based material such as a plywood that can be cut or nailed is used for the close-in. Although these wood-based materials are also moisture-controllable, according to B-23 (Non-patent Document 1) of the 2005 Annual Conference of the Air Conditioning and Sanitary Engineering Society, non-patent documents 1 When wood is compared with the case where it is applied to the board, the humidity control property of the wood is as low as 1/2 or less. For this reason, humidity control materials for close-in are commercially available. However, a board made by mixing a highly moisture-controllable material and a binder cannot be cut or nailed, and it is necessary to use an adhesive at the time of construction, and the indoor environment caused by substances released from the adhesive There was also a risk of deterioration.

Therefore, there is a demand for a board that is not wet, has high humidity control by simply sticking, and has good workability capable of cutting and nailing.
Japanese Patent No. 2651593 Hiroshi Nakagawa, 4 others, “Research on indoor environmental conservation by using Wakkanai diatomaceous earth (Part 1) Effects on symptoms of patients with atopic dermatitis”

  The present invention has been made in view of the above points, and an object of the present invention is to provide a humidity-controlling vegetable fiber board having high humidity controllability and good processability.

  The humidity control vegetable fiber board according to claim 1 of the present invention is formed by bonding lignocellulosic fibers 1 obtained from plants with a binder 2 and holding a humidity control material 3 therein. It is a feature.

  According to a second aspect of the present invention, in the first aspect, the lignocellulosic fibers 1 obtained from plants are bonded together with a binder 2 to form a vegetable fiber mat 4, and the humidity control material 3 is formed between the plurality of plant fiber mats 4. It is characterized by being press-molded in a state where a humidity control material layer 5 made of is interposed.

  The invention according to claim 3 is characterized in that, in claim 2, the humidity control material 3 is also held inside the vegetable fiber mat 4.

  The invention according to claim 4 is the invention according to claim 2 or 3, wherein the thickness of the vegetable fiber mat 4 laminated on one side and the thickness of the vegetable fiber mat 4 laminated on the other side through the humidity control material layer 5 are as follows. Is characterized by being different.

  The invention according to claim 5 is characterized in that, in any one of claims 1 to 4, the humidity control material 3 is diatomaceous earth.

The invention according to claim 6 is characterized in that, in any one of claims 1 to 5, the density is 400 kg / m ³ or more and 2000 kg / m ³ or less.

  According to the humidity control vegetable fiber board according to claim 1 of the present invention, the lignocellulosic fibers are intertwined with each other, and an infinite number of voids are formed in the board and communicated with the outside. By being dispersed and held, moisture can freely move between the inside and the outside of the board, so that humidity control can be improved and workability such as cutting and nailing can be improved. Is. Moreover, since the humidity control material is held inside the board, it does not peel off from the board.

  According to the second aspect of the present invention, the humidity control material is sandwiched and held between the plurality of plant fiber mats so that the binder film is not formed on the surface of the humidity control material. The moisture absorbing / releasing ability of the humidity control material can be utilized to the maximum, and the humidity control can be further enhanced.

  According to the invention which concerns on Claim 3, the quantity of the humidity control material contained in the whole inside of a board is increased by not only the humidity control material layer but also the inside of a vegetable fiber mat containing the humidity control material. It is possible to further improve humidity control.

  According to the invention which concerns on Claim 4, when the thickness of the vegetable fiber mat laminated | stacked on either side via a humidity control material layer is thick, the intensity | strength of a board can be raised and bending is reduced. It is something that can be done. Even if the entire board must be thickened to reduce deflection, etc., if the thickness of the vegetable fiber mat on the exposed side is reduced, the outside air and humidity can be controlled. Since the distance to the material layer is shortened and external moisture easily reaches the humidity control material layer, the humidity control property can be sufficiently ensured.

  According to the invention which concerns on Claim 5, diatomaceous earth can further improve humidity control property by having a high moisture absorption-release property compared with another humidity control material.

According to the invention according to claim 6, when the board density is 400 kg / m ³ or more, the strength can be prevented from being lowered, and the board density is 2000 kg / m ³ or less. Therefore, it is possible to prevent a decrease in humidity control properties.

  Embodiments of the present invention will be described below.

  FIG. 1 shows an example of an embodiment of the present invention. This humidity-controlling plant fiber board A (hereinafter also simply referred to as board A) uses lignocellulose fibers 1 obtained from plants as a base material. The materials are bonded to each other with a binder 2 and a humidity control material 3 is held inside.

  Since the lignocellulosic fibers 1 as the base material are intertwined with each other to form the board A, a gap 6 is inevitably generated inside or on the surface of the board A.

  FIG. 2 is a schematic diagram for explaining the state of the gap 6 when the board A is sliced thinly in the thickness direction. The lignocellulosic fibers 1 are entangled with each other and a void 6 is formed between them. The humidity control material 3 is uniformly dispersed and held in the gap 6. As described above, when the humidity control material 3 is uniformly dispersed in the board A, moisture enters the gap 6 of the board A when wet and is absorbed by the humidity control material 3 inside the board A. In addition, the moisture released from the humidity control material 3 during drying is released to the outside through the gap 6 of the board A. Thus, the board A with high humidity control is realizable by including the humidity control material 3 in the board A of the lignocellulosic fiber 1 excellent in moisture permeability.

  In addition, since the humidity control material 3 is held inside the board A, it does not cause peeling and can be cut or nailed.

  As the lignocellulosic fiber 1 used in the present invention, those composed mainly of cellulose and lignin can be used. Specifically, fibers collected from basts of hemp plants such as kenaf, flax, ramie, cannabis, jute, fibers collected from stem or leaf muscles of hemp plants such as Manila hemp and sisal hemp, Wood fiber is mentioned. These fibers are composed of components such as hemicellulose and pectin in addition to cellulose and lignin.

  Among the fibers mentioned here, hemp plant fibers have a high ratio of crystalline and high-strength cellulose of 60% or more and 30 to 50% of wood fibers, and have high strength as fibers. In addition, fibers having a length of 20 mm or more and a diameter of 30 to 200 μm can be easily obtained from these plants by water immersion treatment called physical letting and physical fibrillation treatment.

  The lignocellulosic fiber 1 used in the present invention is not limited to these, as long as the fiber obtained by any of the above treatments is used, as long as it is formed into a fiber or a yarn by spinning. Moreover, you may use what processed the lignocellulose fiber 1 into the sheet form, the nonwoven fabric, and the woven fabric.

  Moreover, it does not specifically limit about the binder 2 used by this invention. Specific examples include thermosetting resin adhesives such as urea, melamine, phenol / epoxy resins and urethane resins, vinyl acetate adhesives, synthetic rubber adhesives, and emulsion adhesives of polylactic acid and starch resins. Can be mentioned.

  Here, the method for incorporating the binder 2 into the lignocellulose fiber 1 as the substrate is not particularly limited. Specifically, a method of spraying the binder 2 onto the lignocellulose fiber 1 and a method of impregnating the lignocellulose fiber 1 into the binder 2 are exemplified.

  Moreover, about the humidity control material 3 used by this invention, if it is a material which has a moisture absorption / release property, it will not specifically limit. Specifically, charcoal such as charcoal and bamboo charcoal, talc, zeolite, diatomaceous earth, silica gel, montmorillonite, clay minerals such as sepiolite, inorganic substances such as alumina and silica, and the like can be given. Since these materials are porous materials and have moisture absorption and desorption by entering and exiting these holes, they often have absorptivity for chemical substances in the air. Functions can be added to board A.

  Here, the method of uniformly dispersing and holding the humidity control material 3 in the board A is not particularly limited. Specifically, a method of spraying or impregnating lignocellulosic fibers 1 with a liquid binder 2 in which the humidity conditioning material 3 is dispersed, or after dispersing the humidity conditioning material 3 in the lignocellulose fibers 1, the binder 2 and a method of mixing lignocellulosic fiber 1, binder 2 and humidity control material 3 at the same time.

  And after making the lignocellulose fiber 1 contain the binder 2 as mentioned above, and disperse | distributing the humidity-control material 3 uniformly, this is press-molded, As shown in FIG. Board A can be obtained. In the board A thus formed, lignocellulosic fibers 1 are intertwined with each other, and an infinite number of voids 6 communicating with the outside are formed inside the board A, and the humidity control material 3 is formed in the voids 6. Is uniformly dispersed and held, moisture can freely move between the inside and the outside of the board A, and the humidity control property can be improved, and the workability such as cutting and nailing is also improved. It is something that can be done. In addition, since the humidity control material 3 is held inside the board A, it does not peel off from the board A.

  FIG. 3 shows another example of the embodiment of the present invention, and the humidity-controlling vegetable fiber board A is produced as follows. First, the lignocellulosic fiber 1 obtained from a plant is used as a base material, and the base material is adhered to each other with a binder 2 to produce a plant fiber mat 4. Next, a plurality of plant fiber mats 4 formed in this way are prepared, and a humidity control material layer 5 made of the humidity control material 3 is interposed between the plurality of plant fiber mats 4 as shown in FIG. And by press-molding in this state, a moisture-conditioning vegetable fiber board A having a sandwich structure as shown in FIG. 3 can be obtained. In the board A thus formed, the humidity control material 3 is sandwiched and held between the plurality of plant fiber mats 4, so that the film of the binder 2 is formed on the surface of the humidity control material 3. Is not formed, the surface of the humidity control material 3 is sufficiently exposed, the absorption and release ability of the humidity control material 3 can be utilized to the maximum, and the humidity control property can be further enhanced. is there.

  FIG. 3 shows a humidity control layer 5 formed between two vegetable fiber mats 4. However, the number of plant fiber mats 4 used and the number of humidity control material layers 5 formed are not limited thereto. Needless to say. FIG. 5 shows a case where four plant fiber mats 4 are used, and a humidity conditioner layer 5 is formed between the plant fiber mats 4 to form a total of three humidity conditioner layers 5.

  FIG. 6 shows another example of the embodiment of the present invention. The humidity-controlling vegetable fiber board A is formed by holding the humidity-controlling material 3 also inside the plant fiber mat 4. It is produced as follows. First, the lignocellulosic fiber 1 obtained from a plant is used as a base material, and the base material containing the humidity control material 3 is blended by uniformly dispersing the humidity control material 3 when the base materials are bonded with the binder 2. A fiber mat 4 is produced. At this time, a method of spraying or impregnating the lignocellulose fiber 1 with the liquid binder 2 in which the humidity conditioning material 3 is dispersed, or after dispersing the humidity conditioning material 3 in the lignocellulose fiber 1, the binder 2 is used. The method of making it contain, the method of mixing the lignocellulose fiber 1, the binder 2, and the humidity control material 3 simultaneously can be used. Next, a plurality of plant fiber mats 4 containing the humidity control material 3 formed in this way are prepared and adjusted between the plant fiber mats 4 containing the plurality of humidity control materials 3 in the same manner as in FIG. A humidity control material layer 5 made of the wet material 3 is interposed. And by press-molding in this state, a moisture-conditioning vegetable fiber board A having a sandwich structure as shown in FIG. 6 can be obtained. In the board A formed in this way, not only the humidity control layer 5 but also the inside of the plant fiber mat 4 includes the humidity control material 3, so that it is included in the entire interior of the board A. The amount of the humidity control material 3 can be increased, and the humidity control property can be further improved.

  FIG. 7 shows another example of the embodiment of the present invention, and this humidity-controlling vegetable fiber board A is manufactured as follows using a plurality of plant fiber mats 4 having different thicknesses. First, the lignocellulosic fiber 1 obtained from a plant is used as a base material, and the base material is adhered to each other with a binder 2 to produce a plant fiber mat 4. Next, a plurality of plant fiber mats 4 having different thicknesses formed in this way are prepared, and a humidity control material comprising the humidity control material 3 between the plurality of plant fiber mats 4 in the same manner as in FIG. Layer 5 is interposed. And by press-molding in this state, a moisture-controlling vegetable fiber board A having a sandwich structure as shown in FIG. 7 can be obtained. In the board A thus formed, the thickness of the vegetable fiber mat 4 laminated on one side via the humidity control layer 5 and the thickness of the vegetable fiber mat 4 laminated on the other side Since the plant fiber mat 4 laminated on either side is thick, the strength of the board A can be increased and the deflection can be reduced. Even if the board A as a whole has to be thickened to reduce bending, if the vegetable fiber mat 4 on the side exposed to the outside is made thin, Since the distance from the humidity control material layer 5 is shortened and external moisture easily reaches the humidity control material layer 5, sufficient humidity control can be ensured.

  FIG. 7 shows a board A produced using two types of plant fiber mats 4 having different thicknesses, but the same board A can be produced using only one type of plant fiber mat 4. . That is, as shown in FIG. 8, the board A similar to the case of FIG. 7 can be produced by varying the number of laminated vegetable fiber mats 4 adjacent to both sides of the humidity control material layer 5. In this way, if only one type of plant fiber mat 4 is used, the productivity of the board A can be improved because it is not necessary to produce various types of plant fiber mats 4 having different thicknesses. It is. The thickness of the vegetable fiber mat 4 laminated on one side (or the other side) via the humidity control material layer 5 is not the thickness of only the plant fiber mat 4 adjacent to the humidity control material layer 5. Means the total thickness of all the plant fiber mats 4 laminated. For example, in the board A shown in FIG. 8, the thickness of the vegetable fiber mat 4 laminated on one side via the humidity control material layer 5 is one, and is laminated on the other side. The thickness of the vegetable fiber mat 4 is a thickness obtained by stacking three sheets.

  In each embodiment mentioned above, it is preferable that the humidity control material 3 is diatomaceous earth. In diatomaceous earth, dead bodies of phytoplankton such as algae called diatoms accumulate on the seabed and lake bottom, and amorphous silicon dioxide deposits on the cell wall, and then the organic matter in the dead body is gradually decomposed, Ultimately, it is a clay-like mud that is a deposit with only its shell portion remaining mainly composed of silicon dioxide. Diatoms have many pores for taking water and nutrients from the outside, and moisture enters and exits these pores. It is known that the pore diameter of diatomaceous earth is distributed in the vicinity of several nm suitable for moisture absorption and desorption, and has high moisture absorption and desorption properties. Therefore, by using diatomaceous earth with high moisture absorption / release properties as the humidity control material 3, the humidity control property can be further improved.

Further, it is preferable that in each embodiment described above, the density of the humidity conditioning plant fiber board A is less than 400 kg / ^{m 3} or more 2000 kg / ^{m 3.} Thus, when the density of the board A is 400 kg / m ³ or more, the strength can be prevented from decreasing. However, if the density of the board A is less than 400 kg / m ³ , the bond between the lignocellulosic fiber 1 and the binder 2 becomes weak, and it becomes difficult to obtain good characteristics such as strength, or the adjustment from the inside of the board A. There is a possibility that the wet material 3 may spill and be detached. Moreover, when the density of the board A is 2000 kg / m ³ or less, it is possible to prevent a decrease in humidity control. However, if the density of the board A exceeds 2000 kg / m ³ , the ratio of the voids 6 inside the board A becomes small, the moisture permeability becomes low, and as a result, the humidity control property may be lowered. Therefore, it is preferable to set the density of the board A to 400 kg / m ³ or more and 2000 kg / m ³ or less by adjusting the pressure at the time of press molding or the thickness of the board A, thereby adjusting the strength and other characteristics. It is possible to ensure sufficient wettability.

  Hereinafter, the present invention will be specifically described by way of examples.

(Example 1)
Binder: Polylactic acid emulsion (product number: PL-1000, manufacturer: Miyoshi Oil Co., Ltd.) and humidity control material: talc (product number: TT, manufacturer: Takehara Chemical Industry Co., Ltd.) Impregnated with a plant fiber mat (weight per unit area 600 g / m ² ) produced using a kenaf fiber bundle (average diameter 82 μm) obtained from bast, which is the outer skin part of the skin, the weight ratio when dried is plant The fiber mat was adjusted to 600 so that the non-volatile content of polylactic acid was 150 and talc was 250. The impregnated vegetable fiber mat was dried at 100 ° C. for 10 minutes in a dryer, and then two sheets were stacked and press-molded at a mold temperature of 170 ° C. and a pressure of 3.5 MPa for 120 seconds. At that time, a stainless steel bar (distance bar) whose thickness is adjusted so that the board thickness is 0.95 mm and the density is 2100 kg / m ³ is sandwiched between the upper die and the lower die of the press device. By performing press molding, a board as shown in FIG. 1 was produced.

(Example 2)
A board as shown in FIG. 1 was produced in the same manner as in Example 1 except that the thickness of the board was 2 mm and the density was 1000 kg / m ³ .

(Example 3)
As the humidity control material, diatomaceous earth (Wakanai diatomaceous earth, 0.7 mm undersized particle size) is used instead of talc, and the weight ratio when dried is vegetable fiber mat: 600, non-volatile content of polylactic acid: 150, diatomaceous earth: A board as shown in FIG. 1 was produced in the same manner as in Example 2 except that the value was 250.

Example 4
Binder: Polylactic acid emulsion (Part No .: PL-1000, manufacturer: Miyoshi Oil & Fats Co., Ltd.) and plant fiber produced using a kenaf fiber bundle (average diameter 82 μm) obtained from bast which becomes the outer skin part of kenaf stem part A mat (weight per unit area: 600 g / m ² ) was impregnated and adjusted by drawing so that the weight ratio when dried was vegetable fiber mat: 600 and the non-volatile content of polylactic acid: 150. The impregnated plant fiber mat was dried at 100 ° C. for 10 minutes in a drier, and on one sheet, the humidity control material so that the weight ratio when dried was plant fiber mat: 750 and diatomaceous earth: 500: A humidity control layer was formed by uniformly spreading diatomaceous earth. Then, as shown in FIG. 4, another plant fiber mat is stacked on the humidity control material layer formed by uniformly shaking diatomaceous earth and pressed at a mold temperature of 170 ° C. and a pressure of 3.5 MPa for 120 seconds. Molded. At that time, by pressing the stainless steel rod with the thickness adjusted between the upper die and the lower die of the press device so that the board thickness is 2 mm and the density is 1000 kg / m ³ , A board as shown in FIG. 3 was produced.

(Example 5)
Binder: Polylactic acid emulsion (product number: PL-1000, manufacturer: Miyoshi Oil & Fat Co., Ltd.) and humidity control material: diatomaceous earth (Wakkanai diatomaceous earth, 0.7 mm under particle size) prepared in a liquid, kenaf stem Impregnated with a plant fiber mat (weight per unit area 600 g / m ² ) produced using a kenaf fiber bundle (average diameter 82 μm) obtained from bast, which is the outer skin part of the skin, the weight ratio when dried is plant The fiber mat was adjusted to 600 so that the non-volatile content of polylactic acid was 150 and diatomaceous earth was 250. The impregnated humidity control material-containing plant fiber mat is dried at 100 ° C. for 10 minutes in a drier, and then the weight ratio when dried is a plant fiber mat with a humidity control material: 1000, diatomaceous earth : Humidity control material: diatomaceous earth was sprinkled uniformly to form a humidity control material layer. Then, as shown in FIG. 4, another plant fiber mat containing a moisture conditioning material is stacked on the moisture conditioning material layer formed by uniformly sprinkling diatomaceous earth, and a mold temperature of 170 ° C. and a pressure of 3. Press molding was performed at 5 MPa for 120 seconds. At that time, by pressing the stainless steel rod adjusted in thickness between the upper die and the lower die of the press device so that the board thickness is 2 mm and the density is 1250 kg / m ³ , A board as shown in FIG. 6 was produced.

(Example 6)
Binder: Phenol resin adhesive (product number: PL-3725, manufacturer: Gunei Chemical Industry Co., Ltd.), produced using a kenaf fiber bundle (average diameter 82 μm) obtained from bast that becomes the outer skin part of kenaf stem The plant fiber mat (weight per unit area: 600 g / m ² ) was impregnated and adjusted by drawing so that the weight ratio when dried was vegetable fiber mat: 600 and the non-volatile content of phenol resin: 150. The impregnated plant fiber mat was dried at 100 ° C. for 10 minutes in a drier, and thereafter, one vegetable fiber mat impregnated with a weight ratio when dried on three vegetable fiber mats: 750, A humidity control material layer was formed by uniformly dispersing the humidity control material: diatomaceous earth so that the diatomaceous earth was 500. Then, as shown in FIG. 4, another plant fiber mat is stacked on the humidity control material layer formed by uniformly shaking diatomaceous earth and pressed at a mold temperature of 170 ° C. and a pressure of 3.5 MPa for 240 seconds. Molded. At that time, by pressing the stainless steel rod with the thickness adjusted between the upper die and the lower die of the press device so that the thickness of the board is 7 mm and the density is 1000 kg / m ³ . A board as shown in FIG. 8 was produced.

(Comparative Example 1)
3 ply plywood was produced using three pieces of 0.7 mm thick Sina (hardwood) veneer as a wood board. As a binder, a phenol resin adhesive (product number: PL-3725, manufacturer: Gunei Chemical Industry Co., Ltd.) is used, and the application amount of the adhesive surface is such that the nonvolatile content of the phenol resin is 150 g / m ² per unit area. I made it. Then, press molding was performed at a mold temperature of 170 ° C. and a pressure of 3.5 MPa for 240 seconds. At that time, press forming is performed by sandwiching a stainless steel rod having a thickness adjusted between the upper die and the lower die of the press device so that the board thickness is 2.3 mm and the density is 550 kg / m ^3. Thus, a board was produced.

(Comparative Example 2)
Binder: Polylactic acid emulsion (Part No .: PL-1000, manufacturer: Miyoshi Oil & Fats Co., Ltd.) and plant fiber produced using a kenaf fiber bundle (average diameter 82 μm) obtained from bast which becomes the outer skin part of kenaf stem part A mat (weight per unit area: 600 g / m ² ) was impregnated and adjusted by drawing so that the weight ratio when dried was vegetable fiber mat: 600 and the non-volatile content of polylactic acid: 150. The impregnated vegetable fiber mat was dried at 100 ° C. for 10 minutes in a dryer, and then two sheets were stacked and press-molded at a mold temperature of 170 ° C. and a pressure of 3.5 MPa for 120 seconds. At that time, by pressing the stainless steel rod with the thickness adjusted between the upper die and the lower die of the press device so that the thickness of the board is 2 mm and the density is 750 kg / m ³ . A board was made.

(Comparative Example 3)
Binder: Polylactic acid emulsion (product number: PL-1000, manufacturer: Miyoshi Oil & Fat Co., Ltd.) and humidity control material: talc (product number: TT, manufacturer: Takehara Chemical Industry Co., Ltd.) are mixed, and the weight ratio is non-volatile content of polylactic acid. : 250, talc: 250 was prepared. Then, this liquid was applied to the board produced in Comparative Example 1 so that the weight per unit area of the humidity control material: talc was 500 g / m ² , dried at 100 ° C. for 10 minutes in a drier, and further 170 The board was produced by drying for 120 seconds at ° C.

(Characteristic evaluation and results)
Each board obtained as described above is cut into a 30 cm square, placed in a constant temperature and humidity chamber at 25 ° C. and 50% RH for 24 hours, the board is conditioned and weighed, and then the constant temperature at 25 ° C. and 90% RH. The amount of weight increase after 24 hours in the humidity chamber was measured, and this was taken as the amount of moisture absorption. Thereafter, the amount of weight loss after being placed in a constant temperature and humidity chamber at 25 ° C. and 50% RH for 24 hours was measured and used as the moisture release amount.

  Further, an iron ball having a weight of 5 g from a height of 1 m was dropped on the board 20 times vertically, and a change in the board surface was visually observed.

  A summary of the formulation and measurement results of the above Examples and Comparative Examples is shown in [Table 1] below.

  Comparing the moisture absorption / release amounts of Examples 1 to 6 and the moisture absorption / release amounts of Comparative Examples 1 to 3, the moisture absorption / release amount increased in any of the Examples, and the humidity control property was improved. It is confirmed. Moreover, in all of the examples, the humidity control material was held inside the board, so that peeling did not occur, and cutting and nailing were possible.

  In Comparative Example 3, the humidity control material mixed with the binder was applied to the board surface. However, the amount of the binder was increased to prevent peeling, and thus the increase in the moisture absorption / release amount was lower than that in the example. In addition, there was a problem that chipping occurred in the falling ball test.

On the other hand, compared with Example 1, in Example 2, the moisture absorption / release amount increased by changing the board density. In Example 2, since the density of the board is adjusted to an appropriate density of 1000 kg / m ³ , it is considered that there are a relatively large number of voids through which moisture can permeate and the humidity control property is improved.

  Moreover, compared with Example 2, in Example 3, the moisture absorption / release amount increased by using diatomaceous earth as a humidity control material. In Example 3, since diatomaceous earth with a high moisture absorption / release amount is used as the humidity control material, it is considered that the humidity control property is improved.

  Moreover, when Example 3 and Example 4 were compared, the moisture absorption / release amount increased in Example 4 although the type and amount of the humidity control material and the density / thickness of the board did not change. In Example 4, the humidity conditioner layer is sandwiched between the plant fiber mats, the humidity conditioner and the binder are not mixed, and no binder film is formed on the surface of the humidity conditioner. Therefore, it is considered that the moisture absorbing / releasing ability of the humidity control material can be utilized to the maximum, and the humidity control is improved.

  When Example 4 and Example 5 were compared, in Example 5, the moisture absorption / release amount increased. In Example 5, since the amount of the humidity control material contained in the board was increased, it is considered that the humidity control property was improved.

  When Example 4 and Example 6 were compared, although the board thickness was thicker in Example 6, the moisture absorption / release amount did not change. As shown in FIG. 8, the humidity control layer can be secured even on a thick board by setting the distance from the board surface of the humidity control layer to the same as in Example 4 as an asymmetric board structure through the humidity control layer. It is thought that.

It is sectional drawing which shows an example of the humidity control vegetable fiber board which concerns on this invention. It is a perspective view which shows what sliced the humidity control vegetable fiber board same as the above. It is sectional drawing which shows another example of the humidity control vegetable fiber board which concerns on this invention. It is a perspective view which shows the process in the middle of producing the humidity control vegetable fiber board same as the above. It is sectional drawing which shows another example of the humidity control vegetable fiber board which concerns on this invention. It is sectional drawing which shows another example of the humidity control vegetable fiber board which concerns on this invention. It is sectional drawing which shows another example of the humidity control vegetable fiber board which concerns on this invention. It is sectional drawing which shows another example of the humidity control vegetable fiber board which concerns on this invention.

Explanation of symbols

A humidity control vegetable fiber board 1 lignocellulosic fiber 2 binder 3 humidity control material 4 plant fiber mat 5 humidity control material layer

Claims (6)

  A humidity control vegetable fiber board characterized in that lignocellulosic fibers obtained from plants are bonded together with a binder and a humidity control material is held inside.   Lignocellulose fibers obtained from plants are bonded together with a binder to form a plant fiber mat, and press molding is performed with a humidity control material layer made of a humidity control material interposed between a plurality of plant fiber mats. The humidity-controlling vegetable fiber board according to claim 1, wherein   The humidity control vegetable fiber board according to claim 2, wherein a humidity control material is also held inside the plant fiber mat.   The humidity control property according to claim 2 or 3, wherein the thickness of the vegetable fiber mat laminated on one side via the humidity control material layer is different from the thickness of the vegetable fiber mat laminated on the other side. Plant fiber board.   The humidity control plant fiber board according to any one of claims 1 to 4, wherein the humidity control material is diatomaceous earth. The humidity-adjustable vegetable fiber board according to any one of claims 1 to 5, wherein the density is 400 kg / m ³ or more and 2000 kg / m ³ or less.

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