JP2011042034A - Adsorbing sheet - Google Patents

Abstract

【Task】
Provided is an adsorbent sheet that has permeation suppressing ability not only for gaseous organic chemical substances but also for liquid chemical substances, and is excellent in flexibility, air permeability, and peel strength.
[Solution]
An adsorbing sheet in which a protective layer is laminated on one side of the gas adsorbing layer by laminating with a non-woven hot melt adhesive, and a protective layer is laminated on the other side by quilting. A mass of the nonwoven fabric-like hot melt adhesive to be used is 5 g / m ² or more and 50 g / m ² or less.
[Selection] Figure 1

Description

  The present invention can effectively protect workers from gaseous and liquid organic chemicals that are absorbed from the skin such as organophosphorus compounds and have an adverse effect on the human body, and improve flexibility, breathability, and peel strength. Relates to the suction sheet. The adsorbing sheet of the present invention is particularly suitable for protective materials such as shelters, clothes, gloves, socks, shoes, helmets and covers.

  Various adsorbing sheets for protecting the human body from harmful chemical substances have been proposed. For example, an adsorption sheet in which activated carbon is sandwiched or wrapped in a woven fabric or non-woven fabric to suppress the falling off and scattering of the activated carbon has been proposed, but the lamination method has not been studied in detail. There has not yet been proposed an adsorbing sheet that is excellent in flexibility, air permeability, and peel strength while maintaining the ability to suppress permeation of liquid organic chemicals.

  For example, in Patent Document 1, an adsorption layer is inserted between two carrier layers, and adhesion between the adsorption layer and the carrier layer is achieved by intermittently applying an adhesive in the form of adhesive dots that do not adhere to each other. Adsorption filter materials have been proposed. This adsorbing filter material has an excellent protection function against biological and chemical harmful substances and poisonous substances, but is inferior in flexibility, breathability, and peel strength, and has a problem in wearing feeling when used in protective clothing.

  In Patent Document 2, a protective layer is laminated on both surfaces of a fibrous activated carbon sheet, and after quilting, it is immersed in a water-dispersed binder resin processing bath, and subjected to drying and fixing treatment. There has been proposed an adsorbent sheet that prevents activated carbon dust from falling off and scattering from fiber breakage or powdering due to mechanical force applied to the fibrous activated carbon sheet. Although this adsorbing sheet is excellent in flexibility and air permeability, there is a problem that the permeation suppression ability of the liquid substance is weak due to the through hole formed by the sewing needle by quilting.

JP-A-2005-324025 JP 2003-10679 A

  The present invention was devised in view of such problems of the prior art, and its purpose is to have a permeation suppressing ability with respect to gaseous and liquid organic chemical substances, and is excellent in flexibility, breathability, and peel strength. An object of the present invention is to provide an adsorption sheet in which protective layers are laminated on both sides of a gas adsorption layer.

  As a result of intensive studies on the method of laminating the protective layers on both sides of the gas adsorption layer in order to achieve such an object, the present inventor has protected by partial adhesion obtained by melting a non-woven hot melt adhesive on one surface of the gas adsorption layer. It has been found that effective protection from gaseous and liquid substances and excellent usability can be achieved by laminating layers and laminating a protective layer on the other surface by quilting, and the present invention has been completed.

That is, the present invention is an adsorption sheet in which a protective layer is laminated on one side of a gas adsorbing layer by partial bonding by melting a non-woven hot melt adhesive and a protective layer is laminated on the other side by quilting. The mass of the non-woven hot melt adhesive used for partial adhesion is 5 g / m ² or more and 50 g / m ² or less.

  In a preferred embodiment of the adsorption sheet of the present invention, the gas adsorption layer has any form of a woven fabric, a knitted fabric, a nonwoven fabric, or a felt.

  Moreover, this invention is a protective material characterized by using the said adsorption sheet, especially a protective clothing.

  In the adsorbing sheet of the present invention, a protective layer is laminated on one side of the gas adsorbing layer by partial bonding by melting a non-woven hot melt adhesive, and a protective layer is laminated on the other side by quilting. Therefore, it has a permeation suppressing ability not only for gaseous organic chemical substances but also for liquid organic chemical substances, and is excellent in flexibility, breathability and peel strength. Therefore, it is extremely suitable for use in protective materials such as protective clothing.

It is the schematic of the cross-section of the adsorption sheet of this invention. It is the schematic which showed the gas-penetration resistance test method. It is the schematic which showed the liquid-penetration resistance test method.

Hereinafter, the suction sheet of the present invention will be described in detail.
As shown in FIG. 1, the adsorbing sheet of the present invention has a protective layer 1 laminated on one surface of a gas adsorbing layer 3 with a partial adhesive layer 2 obtained by melting a non-woven hot melt adhesive, and a quilted yarn on the other surface. The protective layer 4 is laminated by 5.

  As the gas adsorption layer used in the adsorption sheet of the present invention, a carbon adsorbent such as activated carbon or carbon black, or a gas adsorbent comprising an inorganic adsorbent such as silica gel, zeolite adsorbent, silicon carbide, activated alumina, etc. However, it can be appropriately selected depending on the target adsorbed substance. Among them, activated carbon that can deal with a wide range of gases is preferable, and fibrous activated carbon that has a large adsorption rate and adsorption capacity and can effectively suppress gas permeation when used in a small amount is more preferable.

  The gas as the adsorbed substance includes a gaseous compound having one or more carbon elements. For example, the gaseous compound includes a gaseous chemical substance having a relatively large molecular weight of 50 or more and capable of being adsorbed by a gas adsorption layer such as activated carbon. Specific examples include organic phosphorus compounds used for agricultural chemicals, insecticides and herbicides, and general organic solvents such as toluene, methylene chloride and chloroform used for painting work and the like.

When fibrous activated carbon is used for the gas adsorption layer, the BET specific surface area is preferably 700 m ² / g or more and 3000 m ² / g or less, and more preferably 1000 m ² / g or more and 2500 m ² / g or less. If the BET specific surface area is less than the above range, a large amount of activated carbon is required to obtain sufficient protection, the material becomes heavy, and there is a concern that the flexibility is inferior. On the other hand, when it becomes larger than the above range, a problem of desorbing the adsorbed gaseous organic chemical substance may occur.

The mass of the fibrous activated carbon is preferably 10 g / m ² or more and 300 g / m ² or less, more preferably 20 g / m ² or more and 200 g / m ² or less. When the mass is less than the above range, the capacity that can be adsorbed is reduced, and the use time is limited. On the other hand, when it exceeds the above range, there is a concern that the flexibility of the sheet material is inferior.

  As raw materials for fibrous activated carbon, in addition to natural cellulose fibers such as cotton and hemp, regenerated cellulose fibers such as rayon, polynosic and solvent spinning methods, polyvinyl alcohol fibers, acrylic fibers, aromatic polyamide fibers, lignin fibers, phenols Synthetic fibers such as system fibers and petroleum pitch fibers may be mentioned, and regenerated cellulose fibers, phenol fibers, and acrylic fibers are preferred from the physical properties (strength etc.) and adsorption performance of the obtained fibrous activated carbon. Fibrous activated carbon can be manufactured by a conventionally known method. For example, a fabric made by weaving, knitting or non-woven fabric using short fibers or long fibers of these raw fibers can be appropriately flame-resistant as necessary. After containing an agent, it can be produced by applying a flameproofing treatment at a temperature of 450 ° C. or lower, and then carbonizing at a temperature of 500 ° C. or higher and 1000 ° C. or lower.

  As a method for forming the gas adsorption layer, a conventionally known method can be adopted. For example, a gas adsorbent is bonded to a sheet base material with a binder, or the gas adsorbent is made into a slurry including an appropriate pulp and binder. A method of making paper by a wet paper machine, or a method of carbonizing and activating the raw material fibers of the gas adsorbent in advance after weaving, knitting or non-woven fabric, and flame-proofing treatment as necessary can be employed.

  The gas adsorption layer preferably has any form of a woven fabric, a knitted fabric, a nonwoven fabric, or a felt. Among these, the form of woven fabric or knitted fabric is preferable from the viewpoints of air permeability, ease of lamination, flexibility, and the like.

  Examples of the protective layer used in the adsorption sheet of the present invention include a woven fabric, a knitted fabric, a nonwoven fabric, a porous film, an apertured film, a membrane material, or a composite material thereof, and may be appropriately selected depending on the purpose of use. it can. The purpose of the protective layer is to protect the adsorbing sheet from mechanical force applied from the outside, to supplement the mechanical strength of the adsorbing sheet, to ensure the ability to suppress the penetration of liquid substances, and the like.

  The adsorbing sheet of the present invention is characterized in that protective layers are laminated on both sides of the gas adsorbing layer, and a different method of laminating protective layers is adopted on each side. That is, a protective layer is laminated on one side of the gas adsorbing layer by partial bonding by melting a non-woven hot melt adhesive, and a protective layer is laminated on the other side by quilting. . If the protective layer is bonded to both sides with an adhesive or bonded to the entire surface, the flexibility, breathability, and peel strength are reduced, or the pores of the gas adsorbent (activated carbon) are blocked by the adhesive, If the protective layers are laminated on both sides by quilting, there is a possibility that the penetration of the liquid substance may occur due to the through hole of the sewing needle. The adsorbing sheet of the present invention has a high flexibility, air permeability, and peeling while having a permeation suppressing ability not only for gaseous organic substances but also for liquid organic chemical substances by the method for laminating the protective layer as described above. Strength can be achieved.

  The adsorbing sheet of the present invention is formed by integrating a gas adsorbing layer and a protective layer by quilting, laminating the protective layer on the gas adsorbing layer, and then bonding the nonwoven fabric hot melt to the surface of the gas adsorbing layer that is not laminated. Another protective layer is laminated via an agent, and this laminate is pressure-bonded with a roll, and then left in a heating furnace at 90 to 150 ° C. for 1 to 10 minutes to melt the adhesive.

  For the quilting process, a conventionally known method can be adopted, and a sewing thread such as polyester, nylon or cotton is preferably used. In view of protection against liquid substances, it is particularly preferable to use an oil-repellent sewing thread.

  The non-woven hot melt adhesive used for partial adhesion is not particularly limited, but from the viewpoint of flexibility, peel strength after adhesion, air permeability, and adsorptivity, from low-melting copolymer polyester, polyamide, polyolefin, etc. It is preferable to use a low-weight nonwoven fabric heat-sealing fiber. A film adhesive is not preferable because it causes a decrease in air permeability and adsorptivity.

  The method for partial adhesion is not particularly limited, but a method in which a non-woven hot melt adhesive is laminated and melted by heating to bond the gas adsorbing layer and the protective layer uniformly and partially with the adhesive is preferable.

The basis weight of the non-woven hot melt adhesive is preferably 5 g / m ² or more and 50 g / m ² or less. Still more preferably 10 g / ^{m 2} or more 40 g / ^{m 2} or less. If the basis weight is less than the above range, there is a problem of a decrease in adhesive strength. On the other hand, if the basis weight exceeds the above range, the flexibility and air permeability are reduced.

  In the adsorption sheet of the present invention, the peel strength at the adhesion interface between the gas adsorption layer and the protective layer via the adhesive is preferably 0.2 N or more in both the length direction and the width direction of the material, and more preferably Is 2.0 N or more. When the peel strength is low, the gas adsorbing layer and the protective layer are peeled off, which causes a problem that the protective layer does not function. The upper limit of the peel strength is practically 10.0N.

As described above, the mass of the laminate composed of the gas adsorption layer and the two protective layers is preferably 500 g / m ² or less, and more preferably 450 g / m ² or less. When the mass of the laminate exceeds the above range, the material tends to be heavy and poor in flexibility. The lower limit of mass is practically 30 g / m ² .

  As thickness of the laminated body which consists of a gas adsorption layer and two protective layers, 5.0 mm or less is preferable, More preferably, it is 4.0 mm or less. When the thickness exceeds the above range, the laminate becomes stiff and the workability of the suction sheet is deteriorated. The lower limit of the thickness is actually 1.5 mm.

  The stiffness as an index of flexibility of the laminate composed of the gas adsorption layer and the two protective layers is preferably 0.08 N · cm or less in both the length direction and the width direction of the material, more preferably 0. 0.07 N · cm or less. If the bending resistance exceeds the above range, the material becomes stiff and it becomes difficult to process as an adsorption sheet. The lower limit of the bending resistance is actually 0.005 N · cm.

The air permeability of the laminate composed of the gas adsorption layer and the two protective layers is preferably 50 cm ³ / cm ² · s to 300 cm ³ / cm ² · s, and more preferably 100 cm ³ / cm ² · s. Above 250 cm ³ / cm ² · s. If the air permeability is less than the above range, the air permeability is inferior, and if the air permeability exceeds the above range, the material becomes insufficiently bonded, which may cause a problem of peeling.

The toluene adsorption performance (toluene gas equilibrium adsorption amount) of the laminate composed of the gas adsorption layer and the two protective layers is preferably 20 g / m ² or more. More preferably, it is 25 g / m ² or more. When the toluene adsorption performance is less than the above range, the adsorptivity is poor and the protection against gas is poor. The upper limit of toluene adsorption performance is practically 200 g / m ² .

  The number of gas adsorption layers and the number of protective layers stacked on them must be at least one on each side of the gas adsorption layer, but for the purpose of significantly improving mechanical strength or when there are multiple target gases, It is effective to use a necessary number of gas adsorption layers and protective layers in an overlapping manner.

  Furthermore, in order to further improve the protection of the adsorbing sheet against liquid chemical substances, use a material that has been subjected to water / oil repellent treatment in advance on at least one of the layers constituting the adsorbing sheet before lamination processing. It is preferable that the adsorbent sheet after lamination is subjected to water / oil repellent treatment by post-processing. The water / oil repellent finish may be any conventionally known method and is not particularly limited. It is preferable that at least one layer of the material constituting the adsorbing sheet has a water repellency performance of 2 or higher and an oil repellency of 2 or higher.

  Next, the effects of the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The evaluation methods described in the examples are as follows.

(1) Gas permeation resistance test: An explanatory diagram of this test is shown in FIG. The test article 9 is sandwiched between two glass cells (upper cell 6 and lower cell 11) having an internal volume of 350 cc, and the periphery is sealed with paraffin 10. From the upper cell 6 of this test container, 20 μL of 3-methoxybutyl acetate is dropped onto the test product 9. This is put in a constant temperature box set to 25 ± 2 ° C., and the gas concentration on the lower cell 11 side is sampled from the sampling port 7 every predetermined time (after 4, 8, 12, 24, 48 passes), and by gas chromatography The gas concentration permeated through the test product 9 is measured.

(2) Liquid penetration resistance test: An explanatory diagram of this test is shown in FIG. A filter paper 15 was placed on the glass plate 16, and a test product 14 was placed thereon, and 20 μL of a test solution 13 (methyl salicylate in which a red dye was dissolved) was dropped. Then, pressurize the weight of the bottom area 1 cm ² under a load 1 kgf / cm ^2, a liquid-permeability by the degree of coloration of the filter paper every predetermined time (after 4,8,12,24,36,48 hours later) Judged. No coloration was indicated by ○, slight coloration was indicated by Δ, and coloration was indicated by ×.

(3) Mass: Measured according to JIS-L-10188.4 and JIS-L-10968.4.

(4) Bending / softening (flexibility): Measured according to JIS-L-1096.88.19.2 B method (slide method).

(5) Breathability: Measured according to JIS-L-1096.88.27.1 A method (Fragile type method).

(6) Specific surface area: An adsorption isotherm of nitrogen was determined and calculated by the BET method based on this.

(7) Gas equilibrium adsorption amount: Measured according to JIS-K-1477.

(8) Peel strength: The peel strength at the interface between the protective layer and the adhesive layer was measured according to JIS-L-1089.6.10.

Production of gas adsorption layer As the gas adsorption layer, fibrous activated carbon in the form of a knitted fabric was produced by the following method. A circular knitted fabric with a single yarn fineness of 2.2 dtex and a 20th novolak phenol resin fiber spun yarn having a mass of 220 g / m ² is heated in an inert atmosphere at 410 ° C. for 30 minutes, and then in an inert atmosphere at 880 ° C. Was heated for 20 minutes until carbonization proceeded, and then activated for 2 hours at a temperature of 890 ° C. in an atmosphere containing 12% by volume of water vapor. The obtained gas adsorption layer has a mass of 125 g / m ² , a specific surface area of 1400 m ² / g, a thickness of 0.80 mm, and a gas permeability of 200 cm ³ / cm ² · s with a water level gauge of 1.27 cm. The toluene adsorption performance (toluene gas equilibrium adsorption amount) was 53 g / m ² .

Production of protective layer As a protective layer, a tricot knitted fabric was produced by the following method. Using a 28 gauge two-sheet tricot machine, set polyester filaments (82.5 dtex, 36 filaments) on the front cage and polyester filaments (22 dtex, monofilament) on the back cage, respectively. After knitting a warp knitted fabric with a back 1-0 / 2-3 structure, it was refined by a conventional method and further dyed with a disperse dye. The obtained protective layer had a thickness of 0.28 mm, a mass of 80 g / m ² , and a gas permeability of 500 cm ³ / cm ² · s with a pressure difference of 1.27 cm in water level.

Example 1
The protective layer was overlaid on one surface of the gas adsorption layer, and then quilted and sewn into a diamond pattern at a 2-inch pitch using an oil-repellent polyester yarn to obtain a laminate having a two-layer structure. On the other hand, after laminating a 10 g / m ² non-woven hot melt adhesive (Kureha Tech Co., Ltd., Dynac) on another protective layer, a protective layer is formed on the other surface of the gas adsorption layer having the two-layer structure. The adhesive surfaces were overlapped and all materials were pressure-bonded with a roll. Thereafter, the laminate having the three-layer structure was left in a heating furnace at 120 ° C. for 5 minutes to melt the adhesive. Further, the laminate was dipped in a processing bath of 3 wt% fluorine-based water repellent (Aseihigaku AG970, Meisei Chemical Industry Co., Ltd.) and dried, and then subjected to fixing treatment at 170 ° C., and the water repellent was used as a binder resin. The solid content was 0.5 wt%. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Example 2)
An adsorbent sheet was produced in the same manner as in Example 1 except that a 25 g / m ² non-woven hot melt adhesive (Kureha Tech Co., Ltd., Dynac) was used in the lamination of the protective layer adhesive. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Example 3)
An adsorbent sheet was prepared in the same manner as in Example 1 except that 40 g / m ² of non-woven hot melt adhesive (Kureha Tech Co., Ltd., Dynac) was used in the application of the protective layer adhesive. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Comparative Example 1)
An adsorbent sheet was prepared in the same manner as in Example 1 except that a 3 g / m ² non-woven hot melt adhesive (Kureha Tech Co., Ltd., Dynac) was used in the lamination of the protective layer adhesive. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Comparative Example 2)
An adsorbent sheet was prepared in the same manner as in Example 1 except that a 55 g / m ² non-woven hot melt adhesive (Kureha Tech Co., Ltd., Dynac) was used in the lamination of the protective layer adhesive. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Comparative Example 3)
In the lamination of the protective layer adhesive, a solvent-type adhesive urethane resin (Crisbon, manufactured by DIC Corporation) is used in place of the non-woven hot melt adhesive, and this solvent-type adhesive urethane resin 25 g / m ² is gravure-type According to the same method as in Example 1, except that the adhesive was coated so that the area ratio of the adhesive was 15% and that the adhesive was cured by drying at 150 ° C. for 5 minutes instead of melting in a heating furnace. An adsorption sheet was prepared. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Comparative Example 4)
Example 1 except that a 25 g / m ² film-like hot melt adhesive (manufactured by Nippon Matai Co., Ltd., Elfant NT) was used instead of the nonwoven fabric-like hot melt adhesive in the lamination of the protective layer adhesive. An adsorption sheet was produced by the same method. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Comparative Example 5)
Two sheets of 25 g / m ² non-woven hot melt adhesive (Kureha Tech Co., Ltd., Dynac) are prepared on the protective layer, and adhesives for these protective layers are formed on both sides of the gas adsorption layer. Adsorption sheets were prepared in the same manner as in Example 1 except that the surfaces were superposed and all materials were pressure-bonded with a roll to produce a three-layer laminate. Tables 1 to 3 show the gas permeation resistance test results, the liquid permeation resistance test results, the bending resistance (flexibility), the air permeability, and the peel strength evaluation results of the obtained adsorption sheets, respectively.

(Comparative Example 6)
Except that the above protective layers were overlapped on both sides of the gas adsorbing layer, respectively, and then laminated with a three-layer structure by quilting stitching to a diamond pattern at a 2-inch pitch using an oil-repellent polyester yarn. An adsorption sheet was prepared in the same manner as in Example 1. Tables 1 to 3 show the gas permeation resistance test results, liquid permeation resistance test results, bending resistance (flexibility), air permeability, and peel strength evaluation results of the obtained adsorbing sheets, respectively.

  As is apparent from the results of Tables 1 to 3, the adsorbent sheets of Examples 1 to 3 are good in all of gas permeation resistance, liquid permeation resistance, stiffness (flexibility), air permeability, and peel strength. On the other hand, the adsorption sheet of Comparative Example 1 has low peel strength, the adsorption sheet of Comparative Example 2 has low stiffness, and the adsorption sheet of Comparative Example 3 has low gas permeation resistance. The suction sheet of Comparative Example 5 has low stiffness and softness, and the suction sheet of Comparative Example 6 has low liquid permeation resistance. Any of the evaluation items was inferior to that of the example.

  The adsorbing sheet of the present invention is excellent in flexibility, breathability, and peel strength while maintaining the ability to suppress permeation of not only gaseous organic chemicals but also liquid organic chemicals. It is important to contribute to the material industry.

1: Protective layer 2: Partial adhesion layer 3: Gas adsorption layer 4: Protective layer 5: Quilted thread 6: Upper cell 7: Sampling port 8: Test liquid 9: Test article 10: Paraffin 11: Lower cell 12: Weight 13: Test solution 14: Test product 15: Filter paper 16: Glass plate

Claims (4)

An adsorbing sheet in which a protective layer is laminated on one side of the gas adsorbing layer by laminating with a non-woven hot melt adhesive, and a protective layer is laminated on the other side by quilting. A mass of the nonwoven fabric-like hot melt adhesive to be used is 5 g / m ² or more and 50 g / m ² or less.   The adsorption sheet according to claim 1, wherein the gas adsorption layer has a form of any one of a woven fabric, a knitted fabric, a nonwoven fabric, and a felt.   A protective material using the adsorbent sheet according to claim 1.   The protective material according to claim 3, wherein the protective material is protective clothing.