JP4000530B2 - Protective materials and protective clothing - Google Patents

Description

  The present invention relates to protective materials and protective clothing for protecting workers handling hazardous chemical substances. Specifically, it can effectively protect the worker from gaseous and liquid organic chemicals that are absorbed from the skin and have an adverse effect on the human body, such as organic phosphorus compounds, etc. The present invention relates to protective materials and protective clothing that can suppress stress.

  Conventionally, various protective clothing for protecting the human body from harmful chemical substances has been proposed. For example, there is a material made of a material that does not allow permeation of harmful chemical substances, such as a rubber cloth, and has excellent protection performance. However, in this case, the workability is inferior due to the heavy fabric, and there is no air permeability and moisture permeability. Therefore, working in extreme heat or harsh physical work environment adds significant heat stress to the Have the risk of serious health problems.

  On the other hand, a protective laminated fabric made of an adsorbent material such as activated carbon or the like is exemplified. They can effectively release sweat and water vapor released from the body due to breathability and suppress heat stress, but when the concentration of environmental harmful chemicals is high, etc. In this case, the adsorption by the gas adsorbing substance approaches a saturated state, and the protective property is lowered. Moreover, in order to maintain the protective performance for a long time, a relatively large amount of adsorbent material is required, and as a result, the mass of the protective material and the protective garment increases, which causes thermal stress.

  Further, a protective material having selective permeability is exemplified by a polymer based on cellulose. Although this polymer has a permeation suppressing ability and moisture permeation performance for gaseous organic chemicals, a protective material made of the polymer alone cannot completely suppress the permeation of gaseous organic chemicals, and the permeation amount is small. Therefore, when the thickness of the selectively permeable layer is increased, the moisture permeability becomes lower and the material becomes harder and heavier. Also, once gas permeation occurs due to polymer deterioration such as wear and scratches caused by the use of protective clothing, there is a risk that the gas concentration in the clothing suddenly increases. In addition, in the state of wearing protective clothing, if harmful chemical substances intrude from joints such as cuffs, hems, and necks or fasteners, there is no means for secondary removal of them and the wearer cannot be protected. (For example, patent document 1).

Moreover, the protective material obtained by coating polyalkyleneimine or polyallylamine on a moisture-permeable base material is illustrated. In this document, it is described that another adsorbing material such as activated carbon is fixed by an adhesive. However, when adsorbing material is fixed with a general adhesive, the adsorbing material adsorbs components that degrade the gas adsorbability contained in the adhesive, or the pores are covered with the adhesive, and the adsorbing material originally has the adsorbing material. There is a problem that the speed and the adsorption capacity are reduced (for example, Patent Document 2).
11-505775 Japanese Patent No. 3411918

  The present invention is based on the background of the problems of the prior art, and a small amount of gaseous organic chemical substance that has permeated through the permselective layer can be adsorbed and removed by the gas adsorbing layer. Another object of the present invention is to provide a lightweight, flexible, highly moisture-proof protective material and protective clothing that can protect the wearer against gas intrusion from the part and further suppress the heat stress of the wearer.

In order to solve the above problems, the present invention has been completed as a result of intensive studies. In other words, it has a permeation suppression ability for gaseous organic chemicals, and a permeation layer with a moisture permeability of 60 g / m ² · h to 850 g / m ² · h and less and a layer containing a gas adsorbing substance (gas adsorption layer). By having at least one or more selective permeable layers on the outside of the gas adsorption layer as viewed from the inside of the garment.

The protective material according to the present invention is a protective material and a protective garment characterized by having a permselective layer and a gas adsorbing layer. Wear and scratches generated in the process, or gaseous organic chemicals that penetrate from the joints and fasteners can be secondarily adsorbed and removed to improve the safety of the wearer, and a permselective layer is placed outside the gas adsorption layer. In addition to being able to be used for a long time, there is an effect that heat stress can be suppressed by light weight, flexibility and high moisture permeability.
Furthermore, since a non-porous or microporous film or coating is used as the permselective layer, excellent protection against liquid harmful chemical substances, harmful fine dust, bacteria, viruses and other aerosols can be obtained. it can.

Hereinafter, the present invention will be described in detail.
As the material of the selective permeation layer, film forming performance such as polyacrylate, polyacrylonitrile, polyamide, polyamideimide, polyurethane, polyester, copolymer polyester, polyolefin, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, cellulose, cellulose derivative, etc. Any material can be used as long as it has moisture permeability and selective permeability to gaseous organic chemicals after film formation. These materials may be used alone, mixed, or sequentially laminated to form a film.

The permselective layer forms a film and may be used alone, but may be combined with a moisture-permeable base material for reinforcement or protection of the film. The moisture permeability of the substrate needs to be 200 g / m 2 · h or more, preferably 300 g / m 2 · h or more so as not to impair the moisture permeability of the selectively permeable layer. In order to make the protective material lightweight and flexible while maintaining the strength, the thickness of the base material is preferably 0.05 mm or more and 0.50 mm or less. The substrate can have a sheet-like fiber aggregate or a moisture-permeable microporous or nonporous film or membrane.
Sheet fiber aggregates include natural fibers such as cotton, hemp, hair, and silk, regenerated fibers such as rayon, polynosic, cupra, and lyocell, semi-synthetic fibers such as acetate and triacetate, nylon, aramid, vinylon, vinylidene, and polychlorinated Examples include woven fabrics, knitted fabrics, and nonwoven fabrics made of synthetic fibers such as vinyl, polyester, acrylic, acrylic, polyethylene, polypropylene, polyurethane, polyclar, polyallylite, polybenzazole, polyimide, and polyphenylene sulfide. These fibers may be used alone or in combination by blending, blending, union, union, etc. to form a sheet-like fiber assembly.
Examples of the microporous or nonporous film or membrane having moisture permeability include sheet-like materials such as polyethylene, polypropylene, polytetrafluoroethylene, copolymerized polyester, polyurethane, polyether polyurethane, and acrylate.

  The polymer for forming the permselective layer described above is a fine fiber nonwoven fabric obtained by a method of once forming a film of a polymer by a casting method, an extrusion method, an injection molding method, etc., a melt blown method, a flash spinning method, an electrospinning method, etc. Examples thereof include a method of forming a film, a method of coating or dipping the polymer solution or low polymer on the base material, followed by drying or polymerization and solidification.

  When the permselective layer is combined with a base material to form a protective material, the material can be laminated by a laminating method while preventing deterioration of moisture permeability and maintaining the flexibility of the material. When adhering between the permselective layer and the substrate with polyurethane or acrylate emulsion, or when welding or fusing part of the permselective layer or substrate, do not adhere to the entire surface, but instead adhere to dots. It is preferable to do. It is also possible to perform heat bonding through a low-weight nonwoven fabric, a net-like body, or a powder made of low-melting copolymer polyester, polyamide, or polyolefin.

  As the permselective layer, a cellulose derivative or polyvinyl alcohol is preferable in view of the balance between the permeation suppressing ability and moisture permeation performance of the gaseous organic chemical substance. Among them, cellulose diacetate or cellulose triacetate is particularly preferable in terms of excellent permeation suppressing ability with respect to gaseous organic chemical substances.

  The degree of acetylation of the cellulose derivative is 50% (mol%) or more, preferably 55% or more. If it is less than 50%, effective permeation suppression ability may not be obtained depending on the target gaseous organic chemical.

The 6% viscosity, which is an index of the degree of polymerization of the cellulose derivative, is 50 × 10 ⁻³ Pa · S or more and 275 × 10 ⁻³ Pa · S or less, preferably 70 × 10 ⁻³ Pa · S or more and 140 × 10 ⁻³ Pa. -It is preferable that it is below S. If it is 50 × 10 ⁻³ Pa · S or less, effective permeation suppression ability for gaseous organic chemicals cannot be obtained, and if it is 275 × 10 ⁻³ or more, the material becomes stiff and unsuitable for clothing.

  The permselective layer made of a cellulose derivative needs to contain 60 wt% or more of the cellulose derivative, and preferably contains 80 wt% or more. When the content of the cellulose derivative is less than 60 wt%, it is impossible to obtain a highly moisture permeable material while maintaining the permeation suppressing ability with respect to the gaseous organic chemical substance. As the polymer to be blended, for example, by blending with a flexible polymer having resistance to permeation of gas and water vapor, a more flexible permselective layer can be produced while maintaining the moisture permeability and permeation suppression ability of the permselective layer to some extent. Examples of the flexible polymer include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyurethane, and polyethylene terephthalate. Moreover, the softness | flexibility of a permselective layer can also be improved by using a plasticizer together as needed. Examples of the plasticizer include triethyl citrate, diaryl phthalate, dimethyl phthalate, and diethyl phthalate.

  Examples of the solvent for the cellulose derivative include ketones such as acetone, esters such as ethyl acetate, nitrogen-containing compounds such as dimethylformamide, glycols, ethers, halogenated hydrocarbons, and dimethyl sulfoxide. It can be selected as appropriate depending on the hazardous chemical substances and production equipment.

  The polymer solid concentration of the cellulose derivative is excellent in processability when it is in the range of 5 wt% to 30 wt%. If it is less than 5 wt% or more than 30 wt%, the workability deteriorates.

  The thickness of the selectively permeable layer used in the present invention is preferably 3 μm or more and 100 μm or less, and more preferably 5 μm or more and 70 μm or less. If it is 3 μm or less, the protection against gaseous organic chemicals cannot be satisfied and sufficient strength cannot be obtained. On the other hand, if it exceeds 100 μm, the moisture permeability decreases and the material becomes stiff and becomes unsuitable for clothing materials.

The mass of the selectively permeable layer is 100 g / m ² or less, preferably 70 g / m ² or less. If it is 100 g / m ² or more, it cannot be a lightweight protective material which is the object of the present invention.

The moisture permeability of the selectively permeable layer is 60 g / m ² · h to 850 g / m ² · h, preferably 80 g / m ² · h to 750 g / m ² · h. If it is 60 g / m ² · h or less, sweat and vapor emitted from the wearer cannot be effectively released to the outside, and if it exceeds 850 g / m ² · h, the permeation suppression ability for gaseous organic substances cannot be maintained.

  The permselective layer used in the protective material of the present invention preferably has a permeation concentration of a gaseous organic chemical substance to be permeated of 20 ppm or less. More preferably, it is 10 ppm or less. If it exceeds 20 ppm, the load on the gas adsorption layer will increase and the protection time will be shortened.

  The gaseous organic chemical substance here is a gaseous compound having one or more carbon elements. It is a gaseous chemical substance having a relatively large molecular weight of 50 or more and capable of adsorbing a gas adsorbing substance such as activated carbon. For example, 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 can be mentioned.

  Examples of the gas adsorbing substance used in the gas adsorption layer of the present invention include carbon-based adsorbents such as activated carbon and carbon black, or inorganic adsorbents such as silica gel, zeolite-based adsorbent, silicon carbide, and activated alumina. It can select suitably according to the to-be-adsorbed substance. Among them, activated carbon capable of dealing with a wide range of gases is preferable, and fibrous activated carbon is more preferable because it has a large adsorption rate and adsorption capacity and can effectively prevent permeation when used in a small amount.

The BET specific surface area of the activated carbon is preferably 700 m ² / g or more, and more preferably 1000 m ² / g or more in order to obtain a sufficient permeation suppressing ability with a small amount of use. If the BET specific surface area is less than 700 m ² / g, a large amount of activated carbon is required to obtain sufficient protection, and the protective material becomes heavy.

The mass of the activated carbon is preferably 5 g / m ² or more and 100 g / m ² or less, more preferably 10 g / m ² or more and 50 g / m ² or less. If it is less than 5 g / m ² , the capacity that can be adsorbed becomes small and the use time is limited. On the other hand, when it exceeds 100 g / m ² , the protective material becomes heavy and causes heat stress.

  The method of using fibrous activated carbon in order to obtain effective permeation suppression ability with a small amount of use is an effective means, but the raw material of fibrous activated carbon used at that time is natural cellulose fibers such as cotton and hemp Other examples include regenerated cellulose fibers such as rayon, polynosic, solvent spinning, and synthetic fibers such as polyvinyl alcohol fibers, acrylic fibers, aromatic polyamide fibers, lignin fibers, phenol fibers, and petroleum pitch fibers. From the physical properties (strength etc.) and adsorption performance of the fibrous activated carbon obtained, regenerated cellulose fibers, phenolic fibers and acrylic fibers are preferred. After weaving, knitting, and nonwoven fabric using these short fibers or long fibers of the raw material fibers, if necessary containing a suitable flameproofing agent, flameproofing treatment at a temperature of 450 ℃ or less, Subsequently, fibrous activated carbon can be manufactured by the well-known method of activating carbonization at the temperature of 500 degreeC or more and 1000 degrees C or less.

  As a method of making a gas adsorbing material such as fibrous activated carbon into a sheet and forming a gas adsorbing layer, a method of adhering the gas adsorbing material to a sheet base material with a binder, or an adsorbent made into a slurry including an appropriate pulp and binder An adsorbent sheet can be obtained by a method of making paper using a wet paper machine, or a known method of carbonizing and activating the raw material fibers of activated carbon fibers in advance by weaving, knitting, forming a non-woven fabric, and if necessary, flameproofing treatment. .

  Therefore, the form of the fibrous activated carbon sheet includes woven, knitted, non-woven, felt, paper, film, etc., but the workability when wearing protective clothing, fit to the body, flexibility From the standpoint of easy lamination, a woven or knitted shape is preferred.

  There are the following two means for laminating the selectively permeable layer and the gas adsorbing layer. As a first method, a sheet-like, granular, or powdery gas-adsorbing substance is bonded to the permselective layer with an adhesive. The second method includes a method in which either the selectively permeable layer or the gas adsorbing layer is prepared in advance and then the other is coated or dipped.

  Examples of the adhesive used include urethane, vinyl alcohol, ester, epoxy, vinyl chloride, and olefin, but in order to suppress a decrease in moisture permeability due to lamination, urethane is a moisture permeable adhesive. , Vinyl alcohol, and ester are preferred.

  The melt index of the adhesive to be used is preferably 100 g / 10 min or less, and preferably 80 g / 10 min or less. By setting the amount to 100 g / 10 min or less, the area where the adhesive covers the surface of the gas adsorbing substance is reduced at the time of bonding, and the deterioration of the gas adsorbing performance due to lamination can be suppressed.

  Laminating the inner layer additional layer and the gas adsorbing layer in advance by quilting is an effective means for suppressing the deterioration of the performance of the gas adsorbing layer due to the lamination and obtaining a more flexible laminated material. A protective material can be obtained by laminating the two layers in advance by quilting and then laminating the permselective membrane layer with an adhesive.

  At least one selective permeation layer and one gas adsorption layer are required. However, for the purpose of increasing flexibility and when there are multiple target gases, select the necessary number of selective permeation layers and gas adsorption layers. It is an effective means to use in a superimposed manner.

  As the stacking order of the selectively permeable layer and the gas adsorbing layer, it is preferable that there is at least one selectively permeable layer outside the gas adsorbing layer as viewed from the inside of the clothes, considering the life of the gas adsorbing layer. When a plurality of selectively permeable layers are used, a structure in which the gas adsorbing layer is sandwiched between the selectively permeable layers may be used in order to protect the gas adsorbing layer.

The total mass of all the selectively permeable layers and the gas adsorbing layers is preferably 200 g / m ² or less, more preferably 100 g / m ² or less. If it exceeds 200 g / m ² , the load on the wearer will increase, and sweat and vapor emitted from the body cannot be treated with moisture permeability alone.

As shown in FIG. 1, an outer layer additional layer may be provided on the outermost side of the laminated material composed of the selectively permeable layer and the gas adsorbing layer. The purpose of the outer layer additional layer is to protect the permselective layer and the gas adsorbing layer from the mechanical force given from the outside, to supplement the mechanical strength, and to provide the fabric with water repellency and oil repellency, A knitted fabric or a nonwoven fabric is preferred.
As the outer layer additional layer, a woven fabric, a knitted fabric, or a nonwoven fabric having a water repellency of 4 or more when the 5.2 spray test described in JIS L 1092 is performed and an oil repellency of 4 or more according to AATCC Test Method 118 is suitable. However, it is recommended to use one that is flexible.
The laminated material consisting of the permselective layer and the gas adsorbing layer and the outer layer additional layer may be pre-adhered with an adhesive, or may be sewn in a state of being superposed without bonding, considering flexibility, You may make clothes.

As shown in FIG. 1, an inner layer additional layer may be provided on the innermost side of the laminated material composed of the permselective layer and the gas adsorption layer. Examples of the inner layer additional layer include materials such as a woven fabric, a knitted fabric, a nonwoven fabric, and an apertured film, but a woven fabric or a knitted fabric woven or knitted at a coarse density is preferable in terms of moisture permeability and flexibility.
The purpose of the inner layer additional layer is to protect the gas adsorbing substance and the selectively permeable layer from mechanical force applied from the outside, and to suppress the sticky feeling caused by the sweat of the wearer of the protective clothing.

The mass of the laminate provided with the outer layer addition layer and / or the inner layer addition layer is preferably 400 g / m ² or less, more preferably 350 g / m ² or less. If it exceeds 400 g / m ² , the mass of the protective clothing will increase and cause heat stress.

  EXAMPLES Next, although this invention is demonstrated concretely using an Example and a comparative example, this invention is not restrict | limited by these Examples. The evaluation described in the examples is based on the method described below.

Gas permeability test: Figure 2 shows the container used for the test. The test sample is sandwiched between two glass cells with an internal volume of 350 cc, and the periphery is sealed with paraffin. From the upper cell of this test container, 20 μL of 3-methoxybutyl acetate is dropped onto the test product. This is put in a constant temperature box set at 25 ± 2 ° C., the gas concentration on the lower cell side is sampled at regular intervals, and the gas concentration permeated through the test piece is measured by gas chromatography.
Moisture permeability: compliant with JIS L 1099 calcium chloride method.
Specific surface area: An adsorption isotherm of nitrogen is obtained and calculated by the BET method based on this.
Mass: According to JIS L 1018 8.4 and JIS L 1096 8.4.
Thickness: According to JIS L 1018 8.5 and JIS L 1096 8.5.
Melt index: According to JIS K 7210.
Breathability: According to JIS L 1018 8.33 and JIS L 1096 8.4.
Bending resistance: According to JIS L 1096 8.27.
Wearing sensation: Wearing a one-piece protective garment and walking in a constant temperature and humidity room at 32 ° C and 70% RH for 10 minutes at a speed of 5 km / hr, heart rate, blood pressure, skin temperature, rectal temperature, inside the clothes Comprehensive evaluation from temperature and humidity measurement and questionnaire survey.

[Example]
The permselective layer was produced by the following method. Cellulose acetate (Daicel Chemical Industries, Ltd. L-30) with 55% acetylation and 6% viscosity 70 × 10 ^-3 Pa · S is used. The solvent is 1: 1 mixed solution of methyl ethyl ketone and N, N dimethylformamide. A cellulose acetate solution was prepared by mixing and stirring at room temperature so that the solid content concentration was 10 wt%. This solution was cast on a release paper (manufactured by Lintec Corporation), applied while adjusting the film thickness with a coating knife, and dried in an oven. After drying at 70 ° C. for 1 minute, drying was performed at 120 ° C. for 2 minutes. The obtained selectively permeable layer had a thickness of 20 μm, a mass of 20 g / m ² , and a moisture permeability of 175 g / m ² · h.

A fibrous activated carbon fabric was produced as a gas adsorption layer by the following method. A plain fabric with a weight of 85 g / m ² consisting of spun yarn of 2.2 decitex 20 Novolak phenol resin fiber is heated in an inert atmosphere at 410 ° C for 30 minutes, then up to 870 ° C for 20 minutes in an inert atmosphere Then, carbonization was advanced by heating at 870 ° C., and then activated at a temperature of 870 ° C. for 2 hours in an atmosphere containing 12% by volume of water vapor. The mass of the resulting fibrous fibrous activated carbon was 50 g / m ² , specific surface area 1400 m ² / g, thickness 0.40 mm, and air permeability was 470 cm ³ / cm ² · s with a pressure difference of 1.27 cm in water level. It was.

The outer layer additional layer was produced by the following method. Fluorine-based water and oil repellent treatment was applied to a plain woven fabric using 40 yarns of cotton yarn, and 0.54 wt% of resin solids adhered. The resulting woven fabric has a thickness of 0.22 mm, a mass of 120 g / m ² , a bending resistance of 0.56 gf · cm, a breathability of 50 cm ³ / cm ² · s with a water level gauge of 1.27 cm, and a water repellency of 5 The oil repellency was grade 6.

The inner layer additional layer was produced by the following method. Using a 28-gauge 2-sheet tricot machine, set polyester filaments (82.5dtex, 36 filaments) on the front cage and polyester filaments (22dtex, monofilament) on the back cage, respectively, front 1-2 / 1-0, back After knitting a warp knitted fabric with a structure of 1-0 / 2-3, it was scoured by a conventional method and further dyed with a disperse dye. The knitted fabric thus obtained has a thickness of 0.28 mm, a mass of 60 g / m ² , and a breathability of 700 cm ³ / cm ² · s with a water level gauge of 1.27 cm, water repellency of 5 and oil repellency of 6 It was a grade.

The permselective layer and the gas adsorbing layer are bonded to each other by a breathable non-woven hot-melt adhesive (Dynac manufactured by Kureha Tech Co., Ltd.) having a mass of 20 g / m ² and a melt index of 60 g / 10 min. Were laminated by point adhesion using a hot melt type urethane adhesive. The resulting protective material, mass 284 g / m ^2, and a thickness of 1.00 mm, moisture permeability 143g / m ² · h. Table 1 shows the gas permeability test results using this protective material.

Reference example 1
A protective material excluding the gas adsorption layer in Example 1 was produced. The obtained protective material had a mass of 214 g / m ² , a thickness of 0.70 mm, and a moisture permeability of 145 g / m ² · h. Table 1 shows the gas permeability test results using this protective material.

Reference example 2
A permselective layer having a film thickness of 110 μm was prepared according to the same formulation as in Example 1. The obtained protective material had a mass of 374 g / m ² , a thickness of 1.02 mm, and a moisture permeability of 55 g / m ² · h. Table 1 shows the gas permeability test results using this protective material.

Reference example 3
The selectively permeable membrane layer and the fibrous activated carbon layer in Example 1 were point-bonded with a urethane resin having a melt index of 120 g / 10 min. The mass was 304 g / m ² , the thickness was 1.03 mm, and the water vapor transmission rate was 168 g / m ² · h. Table 1 shows the gas permeability test results using this protective material.

  While Example 1 is a suitable protective material with excellent gas permeation suppression ability and wearing feeling, Reference Example 1 causes gas permeation over time and does not provide sufficient protection. In Reference Example 2, the moisture permeability of the selective permeation layer was low, and the wearing feeling was impaired. In Reference Example 3, a small amount of gas permeation could not be suppressed due to a decrease in the adsorption ability of activated carbon.

  The protective material and protective garment of the present invention are capable of adsorbing and removing a small amount of gaseous organic chemical substance that has permeated through the permselective layer by laminating the permselective membrane layer and the gas adsorber layer, and further reducing the weight. It relates to a protective material that is flexible and excellent in wearing feeling, and can be used for protective clothing, agricultural materials, protective tents, medical supplies, etc., and contributes greatly to the industry.

It is a perspective view which shows the protective material made into the laminated body of this invention. It is the schematic which shows the test container used for a gas-permeability test method.

Explanation of symbols

1: outer layer additional layer 2: selective permeation layer 3: gas adsorbing material layer 4: inner layer additional layer 5: upper cell (150 cc)
6: Sampling port 7: Test solution 8: Test product 9: Paraffin sealing 10: Lower cell (150cc)

Claims (3)

Permeability is 60 g / m ² · h made of a cellulose derivative having a permeation suppressing ability for gaseous organic chemicals and having a 6% viscosity of 50 × 10 ⁻³ Pa · S to 275 × 10 ⁻³ Pa · S. More than 850 g / m ² · h or less, 3 μm or more and 100 μm or less selective permeation layer and gas adsorption layer each having at least one layer, and at least one layer outside the gas adsorption layer when viewed from the inside of the clothes A protective material for clothes in which the permselective layer is disposed. The protective material for clothes according to claim 1, wherein the total mass of the selectively permeable layer and the gas adsorption layer is 200 g / m ² or less. A protective garment comprising the garment protective material according to claim 1.

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