Anti-mite sheet

Abstract

To provide an anti-mite sheet that can maintain a high anti-mite effect for a long term.SOLUTION: An anti-mite sheet (1) relating to the present invention is provided with a pair of air-permeable sheets (5, 7) and a B type silica gel (9) which is enclosed in a storage part (3a) defined by the pair of air-permeable sheets (5, 7). The air-permeable sheets (5, 7) include: an air-permeable layer (11) which is composed of an air-permeable material and aerates between the storage part and the outside; and an anti-mite coating layer (17) which is installed on the outer face of the air-permeable layer (11) and which contains boric acid-based glass powder (15) that discharges B2O3. At least one of the pair of air-permeable sheets is characterized by having a humid control layer (23) between the air-permeable layer (11) and the anti-mite coating layer (17).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an anti-mite sheet. [Background technology]

[0002] Dehumidifying sheets, which are made up of a moisture absorbent contained within a breathable sheet, are used to absorb moisture such as sweat released from the body while sleeping by placing them under a mattress, or to dehumidify storage spaces (e.g., chests of drawers, closets) for storing futons, clothes, etc. After the moisture absorption ability of the moisture absorbent has disappeared, these dehumidifying sheets can be used repeatedly by drying the moisture absorbent in the sun, etc., and are also known to have anti-mite effects.

[0003] Patent Document 1 describes an anti-mite moisture-removing sheet that is made of a moisture-removing sheet in which a moisture absorbent such as silica gel is divided and enclosed in a breathable film or nonwoven fabric. This anti-mite moisture-removing sheet exerts an anti-mite effect by reducing the humidity in and around the habitat of mites. Patent Document 1 also describes that, in order to further enhance the anti-mite effect or to extend the duration of the effect, organic agents such as pyrethroid compounds, organophosphorus compounds, carbamate compounds, chitin synthesis inhibitors, and juvenile hormone-like substances may be mixed or treated.

[0004] Patent Document 2 describes that by dispersing a powder of boric acid-based glass, which dissolves B2O3 at a rate of 1 to 300 mg / g / hour in water at 20°C, on the surface of fibers or foams that constitute bedding such as futons, pillows, and mattresses, a stable anti-mite effect can be exhibited for a long period of time. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-29730 A [Patent Document 2] Japanese Patent Application Publication No. 5-320015 Summary of the Invention [Problem to be solved by the invention]

[0006] A dehumidifying sheet having a structure in which a moisture absorbent is encapsulated in a breathable sheet exhibits a dust mite-proofing effect as long as the moisture absorbent has moisture-absorbing ability, as described in Patent Document 1. However, when the moisture-absorbing ability of the moisture absorbent in the dehumidifying sheet is lost, the dust mite-proofing effect is also lost, and dust mites rapidly multiply. An object of the present invention is to provide an anti-mite sheet capable of maintaining a high anti-mite effect for a long period of time. [Means for solving the problem]

[0007] The anti-mite sheet of the present invention is a mite-proof sheet comprising a pair of breathable sheets and B-type silica gel contained in a storage section defined by the pair of breathable sheets, the breathable sheet comprising a breathable layer made of a breathable material for ventilating between the storage section and the outside, and an anti-mite coating layer provided on the outer surface of the breathable layer and containing borate-based glass powder that releases B2O3, and at least one of the pair of breathable sheets has a humidity adjusting layer between the breathable layer and the anti-mite coating layer. Effect of the Invention

[0008] According to the present invention, it is possible to provide an anti-mite sheet that can maintain a high anti-mite effect for a long period of time. [Brief description of the drawings]

[0009] [Figure 1] 1 is a plan view of an anti-mite sheet according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along the line A1-A2 of FIG. [Diagram 3] FIG. 4 is an enlarged schematic view illustrating a humidity adjusting layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] As a result of intensive research, the inventors discovered that in an anti-mite sheet having an anti-mite layer provided on the outside of a moisture absorbent, the anti-mite effect can be improved by providing a humidity adjustment layer between the moisture absorbent and the anti-mite layer, and thus completed the present invention. Hereinafter, an embodiment of the present invention will be described in detail.

[0011] Fig. 1 is a plan view of an anti-mite sheet 1 according to one embodiment of the present invention, and the internal structure is shown in the area surrounded by the curves A3-A4 and the end portion. The anti-mite sheet 1 comprises a pair of breathable sheets 3 including a front sheet 5 and a back sheet 7, and is divided into a plurality of substantially rectangular compartments each containing B-type silica gel 9. A schematic cross-sectional view of A1-A2 in Fig. 1 is shown in Fig. 2. The B-type silica gel 9 is contained in a containing section 3a defined by the pair of breathable sheets 3.

[0012] 2, both the front sheet 5 and the back sheet 7 have a humidity adjusting layer 23 and an anti-mite coating layer 13 provided on the outer surface of the breathable layer 11, but the anti-mite sheet of the present invention is not limited to this. In the anti-mite sheet of the present invention, it is sufficient that at least one of the front sheet 5 and the back sheet 7 has a humidity adjusting layer 23.

[0013] Type B silica gel 9 has the function of absorbing moisture from the surroundings and dehumidifying it. Type B silica gel has a smaller surface area than type A silica gel, but its pore diameter and pore volume are large, so it can adsorb large amounts of moisture in high humidity areas. Moreover, it can be easily regenerated by drying or heating.

[0014] The shape of the B-type silica gel 9 is not particularly limited, and may be bead (spherical), powder, etc., but is preferably bead-shaped because it is easy to handle. The particle size of the bead-type silica gel is not particularly limited, but is usually within the range of 100 μm to 10 mm.

[0015] In the front sheet 5, a humidity adjusting layer 23 and an anti-mite coating layer 13 are sequentially provided on the outer surface of the breathable layer 11. The breathable layer 11 is a layer having breathability, and allows ventilation between the storage section 3a and the outside. In this embodiment, the breathable layer 11 is made of a nonwoven fabric, but the breathable layer 11 is not limited to this and may be a porous resin layer or paper. As the nonwoven fabric, one manufactured by a spunbond method, a meltblowing method, a flash spinning method, or the like can be used.

[0016] Examples of the material of the fibers constituting the nonwoven fabric include polyethylene, polyester, polyethylene terephthalate, etc. The nonwoven fabric used for the breathable layer 11 is preferably a polyethylene terephthalate nonwoven fabric.

[0017] The thickness of the nonwoven fabric may be, for example, within a range of 10 to 100 μm. The basis weight of the nonwoven fabric may be, for example, within a range of 10 to 100 g / m 2 Furthermore, the air permeability of the nonwoven fabric, as measured in accordance with JIS L 1913, can be within the range of 1 to 300 cc / cm. 2 sec, and 50 to 200 cc / cm 2 When the air permeability of the nonwoven fabric is within the above range, sufficient air permeability can be ensured between the outside of the anti-mite sheet 1 and the storage section 3a.

[0018] It is presumed that the humidity adjustment layer 23 provided on the outer surface of the breathable layer 11 absorbs the moisture desorbed from the B-type silica gel 9 in the storage section 3a and suppresses the increase in humidity released to the outside of the anti-mite sheet 1, thereby suppressing the reproduction of mites that prefer high humidity. B-type silica gel has a large moisture absorption amount in high humidity areas, but has the property of easily desorbing moisture when the humidity decreases, whereas binchotan charcoal has the property of not desorbing moisture until the humidity reaches a medium to low humidity range. For this reason, it is presumed that the binchotan charcoal traps some of the moisture desorbed by the B-type silica gel, thereby suppressing a sudden increase in humidity. The humidity adjustment layer 23 will be described with reference to FIG. 3.

[0019] The humidity adjusting layer 23 is a coating layer containing a humidity adjusting agent 25 and an organic binder 27. Examples of the humidity adjusting agent 25 include binchotan charcoal powder, charcoal powder, and diatomaceous earth powder, and binchotan charcoal powder can be used preferably. The particle size of the binchotan charcoal powder is not particularly limited, but is usually within the range of 0.5 to 100 μm. The binchotan charcoal powder is applied to the humidity adjusting layer 1 m. 2 It is preferable that the amount of Binchotan charcoal powder is 5g or more per unit area. The amount of Binchotan charcoal powder should be a maximum of 50g or less. If the amount of Binchotan charcoal powder is 5g or less, the humidity control ability will be small and the anti-mite effect will not be improved. Also, if the amount of Binchotan charcoal powder exceeds 50g, the coating layer will be easily peeled off, making it difficult to apply to the dehumidifying sheet.

[0020] The organic binder 27 fixes the humidity adjusting agent 25 to the breathable layer 11. Examples of materials for the organic binder 27 include polyethylene resin, polypropylene resin, polyurethane resin, polystyrene resin, polyvinyl chloride resin, polyamide resin, polycarbonate resin, polyacetal resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin, etc. These resins may be used alone or in combination of two or more.

[0021] In consideration of the adhesiveness to the breathable layer 11, the organic binder 27 is preferably made of the same type of resin material as that of the breathable layer 11.

[0022] The anti-mite coating layer 13 provided on the outer surface of the humidity adjusting layer 23 is composed of borate-based glass powder 15 and an organic binder 17. The borate-based glass powder 15 gradually dissolves from the surface in water or in humid air, eluting B2O3, and the eluted B2O3 exerts the anti-mite effect. The borate-based glass powder 15 is preferably one that elutes B2O3 at a rate of 1 to 300 mg / g / hour in water at 20°C.

[0023] Examples of boric acid-based glass powders include B2O3-SiO2-Na2O-based glass powders, B2O3-Na2O-RO-based glass powders (R is an alkaline earth metal), and B2O3-Na2O-Al2O3-based glass powders, all of which are mainly composed of B2O3. As the boric acid-based glass powder, for example, Segurosera manufactured and sold by Ishizuka Glass Co., Ltd. can be used.

[0024] The organic binder 17 may be the same as the organic binder 27 described above. The anti-mite coating layer 15 contains boric acid glass powder 5 at 1 μm. 2 It is preferable that the amount of the dispersed particles is 0.1 to 10 g per particle.

[0025] The above is an explanation of the front sheet 5, but the back sheet 7 can be configured in the same manner as the front sheet 5. The humidity adjusting layer 23 may be either the sheet 5 or the sheet 7.

[0026] In manufacturing the anti-mite sheet 1 of the present invention, first, a humidity adjusting layer 23 containing a humidity adjusting agent 25 and an organic binder 27 is formed on the surface of the breathable layer 11. Next, an anti-mite coating layer 13 containing a borate-based glass powder 15 and an organic binder 17 is formed on the surface of the humidity adjusting layer 23. Finally, B-type silica gel 9 is contained in the storage section 3a. The manufacturing method of the anti-mite sheet 1 will be described in detail below, taking binchotan charcoal powder as an example of the humidity adjusting agent 25.

[0027] First, prepare a breathable material that will form the breathable layer 11. If necessary, patterns, letters, etc. may be printed on the surface of the breathable layer 11. The printing can be performed by a method such as offset printing a solution obtained by mixing a pigment and a solvent onto the surface of the breathable layer 11.

[0028] The binchotan charcoal powder 25 for forming the humidity adjustment layer 23 is mixed with an organic binder 27 and a solvent and applied to the surface of the breathable layer 11. The solvent is not particularly limited as long as it can adequately disperse the binchotan charcoal powder 25, and examples of the solvent include a mixed solvent of isopropyl alcohol, toluene, and methyl ethyl ketone.

[0029] The coating method is preferably to print with some gaps so as not to make the breathability of the breathable sheet too poor. Examples of printing methods include gravure printing and offset printing. The amount of binchotan charcoal powder 25 contained in the humidity adjustment layer is 5 to 50 g / m2 relative to the area of ​​the anti-mite sheet. 2 It is preferable to coat the coating material so that the coating amount falls within the range of 1.

[0030] Next, the humidity adjustment layer is dried. The drying can be performed by any method, for example, by attaching the humidity adjustment layer to a roll. The solvent is evaporated by drying, and the humidity adjustment layer 23 can be provided on the surface of the breathable layer 11.

[0031] The anti-mite coating layer 13 is formed on the surface of the humidity adjusting layer 23. To form the anti-mite coating layer 13, a mixture of borate-based glass powder 15, an organic binder, and a solvent is applied to the surface of the humidity adjusting layer 23. The solvent is not particularly limited as long as it can adequately disperse the borate-based glass powder 15, and the solvents described above can be used.

[0032] The borate-based glass powder 15 mixed with the solvent is printed on the surface of the humidity adjustment layer 23 by an appropriate method. It is preferable to print with some gaps so as not to excessively reduce the breathability of the breathable sheet. Examples of the printing method include gravure printing and offset printing. The borate-based glass powder 15 is applied in an amount of 0.1 to 10 g / m2 relative to the area of ​​the anti-mite sheet. 2 It is preferable to coat the coating material so that the coating amount falls within the range of 1.

[0033] Next, the anti-mite coating layer 13 is dried. The drying can be performed by any method, for example, by closely contacting the anti-mite coating layer 13 with a roll. The solvent is evaporated by drying, and the anti-mite coating layer 13 can be attached to the surface of the humidity adjustment layer 23.

[0034] In this way, two breathable sheets are produced, one of which is the front sheet 5 and the other the back sheet 7, and the front sheet 5 and the back sheet 7 are laminated together with the B-type silica gel 9 contained therein. The sheets can be laminated together by heat sealing, applying an adhesive, sewing, or other methods. The humidity adjusting layer 23 may be provided only on the front sheet 5. EXAMPLES

[0035] The present invention will be described in detail below with reference to examples. However, the object of the present invention is not limited to these examples, and the present invention is not limited to these examples.

[0036] <Example> (1) Material The following materials were used: (a) Breathable layer A nonwoven fabric (made of polyethylene terephthalate) was used as the breathable layer. The breathability of the nonwoven fabric used was measured according to JIS L1913 and found to be 186 cc / cm 2 -sec. (b) B-type silica gel Type B silica gel with a particle size of 3 to 5 mm was used. (c) Humidity regulator Binchotan charcoal powder (D50 = approximately 5 μm) was used. (d) Boric acid glass powder Segurosera (manufactured by Ishizuka Chemical Co., Ltd., D98% = 8 μm or less) was used. (e) Organic binder A urethane resin medium was used. (f) Solvent A mixed solvent of isopropyl alcohol, toluene, and methyl ethyl ketone was used.

[0037] (2) Manufacturing procedure The above-mentioned bincho charcoal powder was mixed with a resin-based medium in a solvent, and the bincho charcoal powder was applied to the surface of the nonwoven fabric at a density of 18 g / m 2 The coated nonwoven fabric was then wrapped around a heated roll and heated to volatilize the solvent, thereby obtaining a sheet having a humidity adjusting layer on the surface of the nonwoven fabric.

[0038] The borate-based glass powder and the resin-based medium are mixed in a solvent, and the borate-based glass powder is applied to the surface of the humidity adjusting layer at a concentration of 1 g / m 2 The coated nonwoven fabric was then wrapped around a heated roll and heated to volatilize the solvent, thereby obtaining a sheet having a dust mite-proof layer on the surface of the humidity adjusting layer.

[0039] In this way, a breathable sheet was obtained in which a humidity adjusting layer and an anti-mite coating layer were successively formed on the surface of the nonwoven fabric. Also, a breathable sheet was obtained in which only an anti-mite coating layer was applied by the same method except that a humidity adjusting layer was not provided.

[0040] On the breathable layer of one of the two breathable sheets, B-type silica gel was arranged in a rectangular shape in multiple sections. The other breathable sheet was placed on top of it so that the breathable layers faced each other, and the two sheets were bonded together by heat pressing to obtain an example of an anti-mite sheet.

[0041] As a comparative example, a commercially available anti-mite sheet was prepared, which had the same structure as the anti-mite sheet of the examples except that it did not have a humidity adjusting layer.

[0042] The anti-mite properties (growth inhibition rate) of the anti-mite sheets of the examples and comparative examples were evaluated by a method conforming to the anti-mite performance test method for textile products (growth inhibition test method A) specified in JIS L1920 (2007). That is, each anti-mite sheet was left standing with about 50 Dermatophagoides pteronyssinus for 4 weeks and 6 weeks under an environment of 25°C temperature and 75% relative humidity, and the number of live mites was counted to obtain the growth inhibition rate. The results are summarized in the following table.

[0043] [Table 1]

[0044] As shown in the above table, the anti-mite sheet of the Example had a higher proliferation inhibition rate after 4 weeks than the anti-mite sheet of the Comparative Example. After 6 weeks, the proliferation inhibition rate of the anti-mite sheet of the Comparative Example decreased, whereas the proliferation inhibition rate of the anti-mite sheet of the Example further increased to as high as 99.9%. The anti-mite sheet of the Example has a humidity adjusting layer containing binchotan charcoal powder between the breathable layer and the anti-mite coating layer. This structure significantly improves the anti-mite effect. [Explanation of symbols]

[0045] 1...Anti-mite sheet 3...Breathable sheet 3a...Storage section 5...Outer sheet 7... Back sheet 9... B-type silica gel 11... Breathable layer 13... Anti-mite coating layer 15... boric acid-based glass powder 17... organic binder 23... humidity adjustment layer 25... Humidity regulator 27... Organic binder

Claims

1. An anti-mite sheet comprising a pair of breathable sheets and B-type silica gel contained in a storage section defined by the pair of breathable sheets, The breathable sheet is A breathable layer made of a breathable material and configured to allow ventilation between the storage section and the outside; A layer B is provided on the outer surface of the breathable layer. ２ O ３ and an anti-mite coating layer containing boric acid-based glass powder that releases At least one of the pair of breathable sheets has a humidity adjusting layer between the breathable layer and the anti-mite coating layer.

2. The humidity adjustment layer is made of binchotan charcoal powder as a humidity adjuster, and the ２ 2. The anti-mite sheet according to claim 1, wherein the anti-mite sheet contains the anti-mite agent in an amount of 5 g or more per unit area.

3. The boric acid glass powder contained in the anti-mite coating layer is dissolved in water at 20° C. at a rate of 1 to 300 mg / g / hour. ２ O ３ The anti-mite coating layer is 1m thick. ２ 3. The anti-mite sheet according to claim 1, wherein the anti-mite sheet contains the anti-mite agent in an amount of 0.1 to 10 g per unit area.

4. The breathable layer is made of a nonwoven fabric and has an air permeability of 1 to 300 cc / cm as measured in accordance with JIS L 1913. ２ 3. The anti-mite sheet according to claim 1, wherein the anti-mite sheet has a viscosity of 1.0 s.

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