The present invention relates to a fabric for arc-resistant protective clothing that includes spun yarn. The spun yarn includes modacrylic fibers in an amount of 38 mass% to 65 mass%, cellulose fibers in an amount of 20 mass% to 55 mass%, and aramid fibers in an amount of 0 mass% to 25 mass%, and the modacrylic fibers contain carbon black in an amount of 0.1 mass% to 6.0 mass% in fibers. Thus, provided are a fabric for arc-resistant protective clothing that has favorable arc-resistant protectiveness and is capable of reducing cost and thermal energy during dyeing, and arc-resistant protective clothing that includes the fabric.
The present invention relates to a fabric for arc-resistant protective clothing that includes modacrylic fibers and cellulose fibers, and arc-resistant protective clothing that includes the fabric.
To reduce the risk of arc flash, workers such as electric mechanics and factory workers who work in an environment that involves the risk of actually being exposed to an electric arc wear arc-resistant protective clothing. Fabrics that include modacrylic fibers and aramid fibers are widely used in arc-resistant protective clothing. For example, as fabrics for use in thermal protective clothing, Patent Document 1 describes fabrics that include yarn made of aramid fibers containing carbon particles and modacrylic fibers.
Patent Document 1:
However, when a fabric includes modacrylic fibers and aramid fibers as described in Patent Document 1, it is necessary to increase the mixture ratio of expensive aramid fibers to ensure the arc-resistant protectiveness, which leads to a problem of an increase in raw material cost. Also, when aramid fibers that have not been subjected to spun-dying are mixed, dyeing need to be conducted using a disperse dye in high-temperature environment (at approximately 160°C), which leads to a problem in that the dyeing requires high thermal energy and the productivity decreases due to an increase in the number of dyeing processes and the like. In addition, there is a risk that a fabric cannot be dyed when the fabric hardens due to shrinkage of mixed modacrylic fibers caused by heating at a high temperature.
In order to solve the aforementioned conventional problems, the present invention provides a fabric for arc-resistant protective clothing that has favorable arc-resistant protectiveness and is capable of reducing cost and thermal energy during dyeing, and arc-resistant protective clothing that includes the fabric.
One or more embodiments of the present invention relate to a fabric for arc-resistant protective clothing that includes spun yarn, wherein the spun yarn includes modacrylic fibers in an amount of 38 mass% to 65 mass%, cellulose fibers in an amount of 20 mass% to 55 mass%, and aramid fibers in an amount of 0 mass% to 25 mass%, and the modacrylic fibers contain carbon black in an amount of 0.1 mass% to 6.0 mass% in fibers.
One or more embodiments of the present invention relate to arc-resistant protective clothing that includes the above fabric for arc-resistant protective clothing.
With the present invention, it is possible to provide a fabric for arc-resistant protective clothing that has favorable arc-resistant protectiveness and is capable of reducing cost and thermal energy during dyeing, and arc-resistant protective clothing that includes the fabric.
The inventors of the present invention conducted numerous studies in order to ensure the arc-resistant protectiveness of a fabric for arc-resistant protective clothing that includes modacrylic fibers and to reduce the cost and the thermal energy during dyeing. As a result, reducing the mixture ratio of aramid fibers by using modacrylic fibers containing a predetermined amount of carbon black and cellulose fibers together made it possible to obtain a fabric having excellent arc-resistant protectiveness while reducing the cost and the thermal energy during dyeing.
Specifically, it is preferable that a fabric for arc-resistant protective clothing according to one or more embodiments of the present invention has excellent arc-resistant protectiveness with the ATPV measured based on ASTM F 1959/F 1959M-12 (Standard Test Method for Determining the Arc Rating of Materials for Clothing) being 8.0 cal/cm2 or more.
Also, the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention includes spun yarn that includes aramid fibers, which require a high temperature when dyed, in a low blend amount or no aramid fibers, and thus the cost and the thermal energy required for dyeing can be reduced while favorable dyeing processability is achieved.
In this specification, when a numerical range is shown using "to", the numerical range includes the values at both ends (i.e., the upper limit and the lower limit). For example, a numerical range "A to B" is a range that includes A and B, which are the values at the two ends of the range, and is the same range as "A or more and B or less". Also, any number and any included range falling within the range is specifically disclosed. Also, when a plurality of numerical ranges are described in this specification, numerical ranges obtained by using the upper limits and the lower limits of the different numerical ranges in combination as appropriate are included. Also, when a plurality of upper limits and lower limits of numerical ranges are separately described, numerical ranges obtained by using the upper limits and the lower limits in combination as appropriate are included.
In one or more embodiments of the present invention, a fabric for arc-resistant protective clothing includes spun yarn I that includes modacrylic fibers containing carbon black (also referred to as "modacrylic fibers I" hereinafter) and cellulose fibers as essential components, and optionally aramid fibers in a small amount.
The modacrylic fibers I contain a modacrylic resin and carbon black, and the content of the carbon black in the fibers is 0.1 mass% to 6.0 mass%. Due to the modacrylic fibers I containing the carbon black in an amount of 0.1 mass% or more, even when the mixture ratio of aramid fibers is reduced or no aramid fibers are used in spun yarn that includes the modacrylic fibers I and cellulose fibers, a fabric produced using the spun yarn can exhibit excellent arc-resistant protectiveness. In particular, when the modacrylic fibers I contain the carbon black in an amount of 6.0 mass% or less, the strength of the modacrylic fibers I is maintained to a proper extent, and therefore, the strength and the uniformity ratio of the spun yarn I that includes the modacrylic fibers I and cellulose fibers can be easily maintained at or above a certain level, thus making it possible to favorably produce a fabric using the spun yarn I.
In the modacrylic fibers I, the content of the carbon black in the fibers (inside the fibers) is preferably 0.15 mass% to 5.5 mass%, more preferably 0.18 mass% to 5.0 mass%, even more preferably 0.2 mass% to 4.5 mass%, even more preferably 0.2 mass% to 4.0 mass%, even more preferably 0.2 mass% to 3.8 mass%, even more preferably 0.2 mass% to 3.0 mass%, even more preferably 0.2 mass% to 2.9 mass%, even more preferably 0.25 mass% to 2.9 mass%, even more preferably 0.3 mass% to 2.8 mass%, even more preferably 0.35 mass% to 2.7 mass%, even more preferably 0.40 mass% to 2.6 mass%, and even more preferably 0.45 mass% to 2.5 mass%.
The average particle diameter of the carbon black represented as a median diameter (D50) is preferably 0.3 to 3.0 µm, more preferably 0.5 to 2.8 µm, even more preferably 0.8 to 2.5 µm, and even more preferably 0.8 to 2.0 µm, in terms of dispersibility in the modacrylic resin contained in the modacrylic fibers I. In this specification, the average particle diameter of the carbon black may be measured, for example, using the carbon black in the raw material form before the incorporation into the fibers, or after the carbon black is incorporated into the fibers. The average particle diameter of the carbon black in the raw material form before the incorporation into the fibers can be measured through a laser diffraction/scattering method using a dispersion liquid obtained by dispersing the carbon black in a dispersion medium such as water. Also, the average particle diameter of the carbon black in the fibers can be examined by, for example, measuring the particle diameters of a hundred particles of the carbon black in the fibers through observation using a microscope and determining the arithmetic mean.
In the modacrylic fibers I, the modacrylic resin preferably contains structural units derived from acrylonitrile in an amount of 30 mass% to 85 mass%, structural units derived from a halogen-containing monomer in an amount of 15 mass% to 70 mass%, and structural units derived from another copolymerizable vinyl monomer in an amount of 0 mass% to 5 mass%, more preferably structural units derived from acrylonitrile in an amount of 35 mass% to 80 mass%, structural units derived from a halogen-containing monomer in an amount of 20 mass% to 65 mass%, and structural units derived from another copolymerizable vinyl monomer in an amount of 0 mass% to 5 mass%, and even more preferably structural units derived from acrylonitrile in an amount of 40 mass% to 70 mass%, structural units derived from a halogen-containing monomer in an amount of 30 mass% to 60 mass%, and structural units derived from another copolymerizable vinyl monomer in an amount of 0 mass% to 5 mass%, in terms of flame retardancy, thermal resistance, and the like.
The halogen-containing monomer is preferably one or more selected from the group consisting of halogen-containing vinyl monomers and halogen-containing vinylidene monomers. Examples of the halogen-containing vinyl monomers include vinyl chloride, vinyl bromide, and the like, and examples of the halogen-containing vinylidene monomers include vinylidene chloride, vinylidene bromide, and the like. One of these halogen-containing monomers may be used alone, or two or more of them may be used in combination.
The other copolymerizable vinyl monomer is not particularly limited, but examples thereof include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, salts of the unsaturated carboxylic acids, methacrylic acid esters such as methyl methacrylate, esters of unsaturated carboxylic acids such as glycidyl methacrylate, vinyl esters such as vinyl acetate and vinyl butyrate, sulfonic acid group-containing vinyl monomers, and the like. The sulfonic acid group-containing vinyl monomers can be favorably used in terms of dyeability.
Examples of the sulfonic acid group-containing vinyl monomers include allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, isoprenesulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid, and metallic salts (e.g., sodium salts) thereof and amine salts thereof. One of the sulfonic acid group-containing monomers may be used alone, or two or more of them may be used in combination. The sulfonic acid group-containing vinyl monomer is used as needed, but when the content of structural units derived from the sulfonic acid group-containing vinyl monomer in the modacrylic resin is 3 mass% or less, the production stability during the spinning process is further improved.
The modacrylic resin preferably contains structural units derived from acrylonitrile in an amount of 30 mass% to 85 mass%, structural units derived from a halogen-containing monomer in an amount of 15 mass% to 70 mass%, and structural units derived from a sulfonic acid group-containing vinyl monomer in an amount of 0 mass% to 3 mass%, and more preferably structural units derived from acrylonitrile in an amount of 35 mass% to 80 mass%, structural units derived from a halogen-containing monomer in an amount of 19.5 mass% to 64.5 mass%, and structural units derived from a sulfonic acid group-containing vinyl monomer in an amount of 0.5 mass% to 3 mass%, in terms of flame retardancy, thermal resistance, dyeability, and the like.
The modacrylic resin can be obtained through known polymerization methods such as bulk polymerization, suspension polymerization, emulsion polymerization, and solution polymerization. Out of these methods, suspension polymerization, emulsion polymerization, or solution polymerization is preferable from an industrial point of view.
The modacrylic fibers I may contain a flame retardant in the fibers. There is no particular limitation on the flame retardant, and a known flame retardant for use in modacrylic fibers can be used as appropriate. Examples thereof include antimony compounds, compounds containing tin and zinc (tin-zinc compounds), and the like. The modacrylic fibers I may contain the flame retardant in an amount of, for example, 1 mass% to 33 mass%, 2 mass% to 26 mass%, 3 mass% to 21 mass%, 3.8 to 16 mass%, 4 mass% to 15 mass%, or 6 mass% to 14 mass%.
The modacrylic fibers I preferably contain an antimony compound in an amount of 1.6 mass% to 33 mass%, more preferably 2 mass% to 26 mass%, even more preferably 3 mass% to 21 mass%, and even more preferably 3.8 mass% to 15 mass%. When the content of the antimony compound in the modacrylic fibers I is within the above range, the production stability during the spinning process is excellent while favorable flame resistance is achieved.
Examples of the antimony compound include antimony trioxide, antimony tetroxide, antimony pentoxide, antimonic acid, antimonates such as sodium antimonate, salts thereof, antimony oxychloride, and the like. One or two or more of these compounds can be used in combination. The antimony compound preferably includes one or more compounds selected from the group consisting of antimony trioxide, antimony tetroxide, and antimony pentoxide in terms of production stability during the spinning process.
The modacrylic fibers I preferably contain a tin-zinc compound in an amount of 1 mass% to 20 mass%, more preferably 2 mass% to 18 mass%, even more preferably 4 mass% to 16 mass%, and even more preferably 6 mass% to 14 mass%. When the content of the tin-zinc compound in the modacrylic fibers I is within the above range, the production stability during the spinning process is excellent while favorable flame retardancy is achieved.
There is no particular limitation on the tin-zinc compound, but, for example, a zinc stannate compound or the like can be used in terms of versatility. The zinc stannate compound may be, for example, zinc stannate (ZnSnO3) or zinc hexahydroxystannate (ZnSn(OH)6), and it is preferable that the zinc stannate compound contains zinc hexahydroxystannate in terms of, for example, further improving the flame retardancy of the modacrylic fibers I.
The average particle diameter of the flame retardant (specifically the antimony compound, the tin-zinc compound, or the like) represented as a median diameter (D50) is preferably 0.05 to 2.0 µm, more preferably 0.08 to 1.8 µm, even more preferably 0.1 to 1.5 µm, and even more preferably 0.13 to 1.3 µm, in terms of dispersibility in the modacrylic resin contained in the modacrylic fibers I. In this specification, the average particle diameter of the flame retardant may be measured, for example, using the flame retardant in the raw material form before the incorporation into the fibers, or after the flame retardant is incorporated into the fibers. The average particle diameter of the flame retardant in the raw material form before the incorporation into the fibers can be measured through a laser diffraction/scattering method using a dispersion liquid obtained by dispersing the flame retardant in a dispersion medium such as water. Also, the average particle diameter of the flame retardant in the fibers can be examined by, for example, measuring the particle diameters of a hundred particles of the antimony compound in the fibers through observation using a microscope and determining the arithmetic mean.
Specifically, the modacrylic fibers I may contain the modacrylic resin in an amount of 61 mass% to 98.3 mass%, the carbon black in an amount of 0.1 mass% to 6.0 mass%, and the antimony compound in an amount of 1.6 mass% to 33 mass%, or the modacrylic resin in an amount of 69 mass% to 98.2 mass%, the carbon black in an amount of 0.2 mass% to 5.0 mass%, and the antimony compound in an amount of 1.6 mass% to 26 mass%, or the modacrylic resin in an amount of 75 mass% to 98.2 mass%, the carbon black in an amount of 0.2 mass% to 4.0 mass%, and the antimony compound in an amount of 1.6 mass% to 21 mass%, or the modacrylic resin in an amount of 82 mass% to 98.2 mass%, the carbon black in an amount of 0.2 mass% to 3.0 mass%, and the antimony compound in an amount of 1.6 mass% to 15 mass%, when the sum of the modacrylic resin, the carbon black, and the antimony compound is taken as 100 mass%.
Specifically, the modacrylic fibers I may contain the modacrylic resin in an amount of 74 mass% to 98.9 mass%, the carbon black in an amount of 0.1 mass% to 6.0 mass%, and the tin-zinc compound in an amount of 1 mass% to 20 mass%, or the modacrylic resin in an amount of 77 mass% to 97.8 mass%, the carbon black in an amount of 0.2 mass% to 5.0 mass%, and the tin-zinc compound in an amount of 2 mass% to 18 mass%, or the modacrylic resin in an amount of 80 mass% to 97.8 mass%, the carbon black in an amount of 0.2 mass% to 4.0 mass%, and the tin-zinc compound in an amount of 2 mass% to 16 mass%, or the modacrylic resin in an amount of 83 mass% to 97.8 mass%, the carbon black in an amount of 0.2 mass% to 3.0 mass%, and the tin-zinc compound in an amount of 2 mass% to 14 mass%, when the sum of the modacrylic resin, the carbon black, and the tin-zinc compound is taken as 100 mass%.
The modacrylic fibers I may contain other additives such as an antistatic agent, a coloration inhibitor, a light resistance improver, a whiteness improver, a devitrification inhibitor, and a coloring agent, as needed, as long as the effects of the present invention are not inhibited. The other additives may be contained in an amount of 5 parts by mass or less, 3 parts by mass or less, or 1 part by mass or less, with respect to 100 parts by mass of the modacrylic resin.
The single fiber fineness of the modacrylic fibers I is not particularly limited, but is preferably 1 to 20 dtex and more preferably 1.5 to 15 dtex in terms of the texture and the strength of the fabric. The fiber length of the modacrylic fibers I is not particularly limited, but is preferably 38 to 127 mm and more preferably 38 to 76 mm in terms of strength. In this specification, the single fiber fineness can be measured based on JIS L 1015. One type of the modacrylic fibers I may be used alone, or two or more types of them that differ in the content of carbon black and/or the content of the antimony compound may be used in combination.
The strength of the modacrylic fibers I is preferably 1.6 to 4.0 cN/dtex, more preferably 1.7 to 3.5 cN/dtex, even more preferably 1.8 to 3.2 cN/dtex, even more preferably 1.9 to 3.1 cN/dtex, and even more preferably 2.0 to 3.0 cN/dtex, in terms of spinnability and fabric processability. When the strength of the modacrylic fibers I is 1.6 cN/dtex or more, the strength and particularly the uniformity ratio of the spun yarn I that includes the modacrylic fibers I and cellulose fibers can be easily maintained at or over a certain level, and thus favorable fabric processability is achieved. Also, the elongation of the modacrylic fibers I is not particularly limited, but is preferably 20% to 35% and more preferably 20% to 30%, in terms of spinnability and processability. In this specification, the strength and elongation of the fibers can be measured based on JIS L 1015.
The modacrylic fibers I can be produced by conducting wet spinning in the same manner as in the case of typical modacrylic fibers, except that a spinning solution containing the modacrylic resin, the carbon black, and optionally the flame retardant such as the antimony compound and other additives is used, but there is no particular limitation to this procedure. When the wet spinning method is used, the modacrylic fibers I can be obtained, for example, in the following manner: a resin solution is prepared by dissolving the modacrylic resin in an organic solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, acetone, or dimethylsulfoxide, or an inorganic solvent such as an aqueous solution of a rhodan salt or an aqueous solution of nitric acid, a spinning solution is prepared by adding the carbon black (and optionally the flame retardant such as the antimony compound and other additives) to the resin solution and mixing the resulting solution, the obtained spinning solution is extruded into a coagulation bath through a nozzle and is thus coagulated, and then the coagulated product is washed with water, dried, drawn, and cut to produce the modacrylic fibers I.
The modacrylic fibers I may contain a cationic dye. When containing the cationic dye, the modacrylic fibers I have good color development and high dye fastness. The modacrylic fibers I may contain the cationic dye through dyeing of either the spun yarn or the fabric with the cationic dye, but it is desirable to dye the fabric with the cationic dye in terms of productivity.
The cellulose fibers are not particularly limited, and may be, for example, natural cellulose fibers or regenerated cellulose fibers. Examples of the natural cellulose fibers include cotton fibers, kabok fibers, linen fibers, ramie fibers, jute fibers, and the like. Examples of the regenerated cellulose fibers include rayon fibers, cupra, lyocell, and the like. Also, it is preferable that the cellulose fibers do not contain the flame retardant in terms of cost and fiber physical properties. It is preferable to use the natural cellulose fibers in terms of durability and cost, and it is more preferable to use cotton fibers. One type of the cellulose fibers may be used alone, or two or more types of them may be used in combination.
The single fiber fineness of the cellulose fibers is not particularly limited, but is preferably 1 to 20 dtex, and more preferably 1.5 to 15 dtex, in terms of strength. The fiber length of the natural cellulose fibers is preferably 15 to 38 mm and more preferably 20 to 38 mm in terms of strength. The fiber length of the regenerated cellulose fibers is not particularly limited, but is preferably 38 to 127 mm and more preferably 38 to 76 mm in terms of strength.
The aramid fibers may be para-aramid fibers or meta-aramid fibers. The single fiber fineness of the aramid fibers is not particularly limited, but is preferably 1 to 20 dtex and more preferably 1.5 to 15 dtex in terms of strength. Also, the fiber length of the aramid fibers is not particularly limited, but is preferably 38 to 127 mm and more preferably 38 to 76 mm in terms of strength.
It is preferable that substantially no carbon black is contained in the aramid fibers in terms of the fact that the color of the fabric is biased toward a dark hue. In this specification, the wording "substantially no carbon black is contained" means that the carbon black is not intentionally contained, and the case where the carbon black is contained as an impurity (e.g., in an amount of 0.001 mass% or less) is encompassed in the wording "substantially no carbon black is contained".
The spun yarn I includes the modacrylic fibers I in an amount of 38 mass% to 65 mass%, the cellulose fibers in an amount of 20 mass% to 55 mass%, and the aramid fibers in an amount of 0 mass% to 25 mass%. By producing a fabric using such spun yarn I, the fabric has excellent arc-resistant protectiveness, and the cost and the thermal energy during dyeing are reduced.
The spun yarn I preferably includes the modacrylic fibers I in an amount of 40 mass% to 65 mass%, more preferably 40 mass% to 60 mass%, and even more preferably 40 mass% to 55 mass%, in terms of the arc-resistant protectiveness and the dyeability of the fabric.
The spun yarn I preferably includes the cellulose fibers in an amount of 25 mass% to 53 mass%, more preferably 30 mass% to 45 mass%, and even more preferably 33 mass% to 45 mass%, in terms of the texture, the durability, the dyeability, and the like of the fabric.
The spun yarn I preferably includes the aramid fibers in an amount of 3 mass% to 18 mass% (the aramid fibers preferably contain the meta-aramid fibers in an amount of 0 mass% to 5 mass%), more preferably 3 mass% to 15 mass% (the aramid fibers preferably contain the meta-aramid fibers in an amount of 0 mass% to 5 mass%), even more preferably 4 mass% to 10 mass% (the aramid fibers preferably contain the meta-aramid fibers in an amount of 0 mass% to 5 mass%), and particularly preferably 4 mass% to 7 mass% (the aramid fibers preferably contain the meta-aramid fibers in an amount of 0 mass% to 5 mass%), in terms of reducing the cost and the thermal energy during dyeing while imparting excellent arc-resistant protectiveness.
Specifically, the spun yarn I may include the modacrylic fibers I in an amount of 38 mass% to 60 mass%, the cellulose fibers in an amount of 25 mass% to 50 mass%, and the aramid fibers in an amount of 3 mass% to 18 mass%, or the modacrylic fibers I in an amount of 40 mass% to 60 mass%, the cellulose fibers in an amount of 25 mass% to 50 mass%, and the aramid fibers in an amount of 3 mass% to 18 mass%, or the modacrylic fibers I in an amount of 40 mass% to 60 mass%, the natural cellulose fibers in an amount of 33 mass% to 53 mass%, and the aramid fibers in an amount of 3 mass% to 7 mass%.
The spun yarn I may include the modacrylic fibers I, the cellulose fibers, and the aramid fibers in an amount of 100 mass% in total, or may include other fibers as needed, as long as the effects of the present invention are not inhibited. Examples of the other fibers include natural fibers other than the cellulose fibers, chemical fibers other than the modacrylic fibers I and the aramid fibers, and the like. Examples of the natural fibers include natural animal fibers such as wool fibers, cashmere fibers, and silk fibers, and the like. Examples of the chemical fibers include polyester-based fibers (e.g., polyethylene naphthalate fibers), acrylic fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, polyethylene fibers, polyurethane fibers, polyimide fibers, and the like. The spun yarn I may include, for example, the modacrylic fibers I, the cellulose fibers, and the aramid fibers in an amount of 90 mass% to 100 mass%, 92 mass% to 100 mass%, 95 mass% to 100 mass%, 97 mass% to 100 mass%, or 99 mass% to 100 mass%, in total, and the other fibers in an amount of 0 mass% to 10 mass%, 0 mass% to 8 mass%, 0 mass% to 5 mass%, 0 mass% to 3 mass%, or 0 mass% to 1 mass%.
The single fiber fineness of the other fibers is not particularly limited, but is preferably 1 to 20 dtex and more preferably 1.5 to 15 dtex in terms of strength. The fiber length of the other fibers is not particularly limited, but is preferably 38 to 127 mm and more preferably 38 to 76 mm in terms of strength.
In the spun yarn I, the content of the carbon black derived from the modacrylic fibers I is preferably 0.08 mass% to 3.4 mass%, more preferably 0.1 mass% to 3.0 mass%, even more preferably 0.1 mass% to 2.5 mass%, even more preferably 0.1 mass% to 2.0 mass%, even more preferably 0.15 mass% to 1.8 mass%, even more preferably 0.2 mass% to 1.6 mass%, even more preferably 0.25 mass% to 1.4 mass%, even more preferably 0.25 mass% to 1.2 mass%, and even more preferably 0.25 mass% to 1.0 mass%, with respect to the total mass of the spun yarn I. By using the spun yarn I in which the content of the carbon black is within the above range, the arc-resistant protectiveness of the fabric for arc-resistant protective clothing is easily improved, and its strength is improved.
The spun yarn I can be produced using a known spinning method. The spinning method is not particularly limited, and examples thereof include ring spinning, air spinning, air-jet spinning, and the like. It is preferable to produce the spun yarn I through ring spinning in terms of cost.
The spun yarn I may be single yarn or two-folded yarn. Also, the thickness of the spun yarn is not particularly limited, but may have an English cotton count of 2 to 50 or 5 to 40 in terms of, for example, favorable use for clothing. It is preferable that the spun yarn I has a high uniformity ratio in terms of fabric processability. For example, the yarn unevenness U% (percentage of the average unevenness deviation) is preferably 12% or less when the English cotton count is 15 to 30, the yarn unevenness U% is preferably 11% or less when the English cotton count is less than 15, and the yarn unevenness U% is preferably less than 14% when the English cotton count is more than 30. In this specification, the yarn unevenness U% of the spun yarn can be measured in accordance with JIS L 1095.
The tensile strength of the spun yarn I is preferably 350 to 800 cN, more preferably more than 400 cN and 800 cN or less, even more preferably 410 to 700 cN, and even more preferably 420 to 600 cN, in terms of processability and process stability. In this specification, the tensile strength of the spun yarn can be measured in accordance with JIS L 1095.
The fabric for arc-resistant protective clothing preferably includes the spun yarn I in an amount of 80 mass% to 100 mass%, more preferably 85 mass% to 100 mass%, even more preferably 90 mass% to 100 mass%, even more preferably 95 mass% to 100 mass%, even more preferably 98 mass% to 100 mass%, and particularly preferably 100 mass%, in terms of arc-resistant protectiveness, cost, thermal energy during dyeing, dyeability, and the like.
In the fabric for arc-resistant protective clothing, the content of the carbon black derived from the modacrylic fibers I is preferably 0.08 mass% to 3.4 mass%, more preferably 0.1 mass% to 3.0 mass%, even more preferably 0.1 mass% to 2.5 mass%, even more preferably 0.1 mass% to 2.0 mass%, even more preferably 0.15 mass% to 1.8 mass%, even more preferably 0.2 mass% to 1.6 mass%, even more preferably 0.25 mass% to 1.4 mass%, even more preferably 0.25 mass% to 1.2 mass%, and even more preferably 0.25 mass% to 1.0 mass%, with respect to the total mass of the fabric for arc-resistant protective clothing. When the content of the carbon black is 0.08 mass% or more, the arc-resistant protectiveness is easily improved. When the content of the carbon black is 3.4 mass% or less, the strength of the fabric is improved.
The content of the carbon black in the modacrylic fibers I, the spun yarn I, or the fabric for arc-resistant protective clothing can be determined by measuring the weight of a sample of the modacrylic fibers I, the spun yarn I, or the fabric for arc-resistant protective clothing, dissolving the sample in an organic solvent that has no influence on the carbon black to remove the fibers, removing an inorganic salt other than the carbon black, and measuring a remaining solid content.
The fabric for arc-resistant protective clothing preferably has a basis weight (the mass (ounce) of a fabric per unit area (1 square yard)) of 3 to 9 oz/yd2, more preferably 4 to 8 oz/yd2, and even more preferably 4.7 to 6.8 oz/yd2. When the basis weight is within the above range, arc-resistant protective clothing that is lightweight and has excellent workability can be provided.
When the fabric for arc-resistant protective clothing has a basis weight of 6.8 oz/yd2 or less, the ATPV thereof measured based on ASTM F1959/F1959M-12 (Standard Test Method for Determining the Arc Rating of Materials for Clothing) (also referred to merely as "ATPV" hereinafter) is preferably 8.0 cal/cm2 or more, more preferably 8.5 cal/cm2 or more, even more preferably 9.0 cal/cm2 or more, even more preferably 9.5 cal/cm2 or more, even more preferably 10.0 cal/cm2 or more, and even more preferably 10.5 cal/cm2 or more.
The ATPV measured based on ASTM F1959/F1959M-12 (Standard Test Method for Determining the Arc Rating of Materials for Clothing) per unit basis weight (oz/yd2) of the fabric for arc-resistant protective clothing (also referred to merely as "specific ATPV" hereinafter) is preferably 1.29 (cal/cm2)/(oz/yd2) or more, more preferably 1.35 (cal/cm2)/(oz/yd2) or more, even more preferably 1.40 (cal/cm2)/(oz/yd2) or more, and particularly preferably 1.45 (cal/cm2)/(oz/yd2) or more.
The fabric for arc-resistant protective clothing may be woven fabric or knitted fabric. The weave of the woven fabric is not particularly limited and may be a three foundation weave such as a plain weave, a twill weave, or a sateen weave, or the woven fabric may be a patterned woven fabric obtained by using a special loom such as a dobby loom or a Jacquard loom. Also, the knitting of the knitted fabric is not particularly limited either and may be any of circular knitting, flat knitting, and warp knitting. The woven fabric may be a union fabric and the knitted fabric may be an interknitted fabric. It is desirable that the woven fabric is not a union fabric and the knitted fabric is not an interknitted fabric in terms of productivity. The fabric is preferably a woven fabric, and more preferably a twill woven fabric, in terms of high tear strength and excellent durability. The fabric for arc-resistant protective clothing may include one or more types of spun yarn I, but preferably includes one type of spun yarn I in terms of productivity. For example, when the fabric for arc-resistant protective clothing is a woven fabric, it is preferable to use the same spun yarn I as warp and weft in terms of productivity.
The thickness of the fabric for arc-resistant protective clothing is not particularly limited, but is preferably 0.3 to 1.5 mm, more preferably 0.4 to 1.3 mm, and even more preferably 0.5 to 1.1 mm, in terms of the strength and the comfort of the fabric when used in a piece of workwear. In this specification, the thickness of the fabric for arc-resistant protective clothing can be measured based on JIS L 1096.
The fabric for arc-resistant protective clothing may be dyed in a desired color. Favorable dyeing processability is achieved by using the modacrylic fibers I together with the cellulose fibers, which can be easily dyed. In addition, since the mixture ratio of the aramid fibers is low or no aramid fibers are included, the dyeing load at a high temperature of about 160°C is small, thus making it possible to reduce thermal energy during dyeing. Dyeing of the fabric for arc-resistant protective clothing is not particularly limited and can be conducted similarly to common fabrics that include modacrylic fibers and cellulose fibers. For example, first, the modacrylic fibers I can be dyed with the cationic dye at a temperature of 98°C to 103°C, followed by dyeing of the cellulose fibers with a direct dye or a reactive dye at a temperature of 80°C to 98°C. Since the modacrylic fibers I contain the carbon black, when the modacrylic fibers I are dyed in a dark color, the amount of the cationic dye used can be reduced, and thus the cost can be reduced.
In one or more embodiments of the present invention, arc-resistant protective clothing includes the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention. The arc-resistant protective clothing can be produced, for example, through a known method using the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention. The arc-resistant protective clothing may be single-layer protective clothing in which the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention is used in a single layer, or multi-layer protective clothing in which the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention is used in two or more layers. In the case of multi-layer protective clothing, the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention may be used in all layers, or the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention may be used in at least one layer. When the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention is used in at least one layer in the multi-layer protective clothing, it is preferable to use the fabric for arc-resistant protective clothing according to one or more embodiments of the present invention in the outer layer.
The arc-resistant protective clothing can be favorably used as work clothing for workers such as electric mechanics and factory workers who work in an environment that involves the risk of actually being exposed to an electric arc.
Hereinafter, one or more embodiments of the present invention will be more specifically described by way of examples. Note that the present invention is not limited to the following examples.
The measurement methods and the evaluation methods used in examples and comparative examples are as follows.
The arc testing was conducted based on ASTM F1959/F1959M-12 (Standard Test Method for Determining the Arc Rating of Materials for Clothing) to determine the ATPV (cal/cm2).
The basis weight of the fabric was measured based on JIS L 1096.
The ATPV per unit basis weight (cal/cm2)/(oz/yd2) of the fabric, namely the specific ATPV, was calculated based on the basis weight of the fabric and the ATPV determined through the arc testing.
The average particle diameters of the compounds (the carbon black, the antimony compound, and the like) were measured through the laser diffraction/scattering method using a particle size distribution analyzer ("LA-920" manufactured by HORIBA, Ltd.) after powder of each compound was dispersed in water.
Professional sensory evaluators conducted sensory evaluation of the colors of the fibers and the fabric through a comparison between the samples and the PANTONE color chart, and thus roughly determined the hue.
The single fiber fineness, the strength, and the elongation of the fibers were measured based on JIS L 1015.
The tensile strength and the yarn unevenness (percentage of the average unevenness deviation (U%)) of the spun yarn were measured based on JIS L 1095.
A modacrylic resin consisting of acrylonitrile in an amount of 51 mass%, vinylidene chloride in an amount of 48 mass%, and sodium p-styrenesulfonate in an amount of 1 mass% was dissolved in dimethylformamide such that the concentration was 30 mass%. A spinning solution was prepared by adding, to the obtained modacrylic resin solution, 10 parts by mass of antimony trioxide (Sb2O3, manufactured by Nihon Seiko Co., Ltd. under the trade name "PATOX-M" which has an average particle diameter of 1 µm) and 10 parts by mass of carbon black (manufactured by Cabot Japan K.K. under the trade name "N330-L", which has an average particle diameter of 1 µm) with respect to 100 parts by mass of the modacrylic resin. As the antimony trioxide, a dispersion liquid thereof prepared in advance by adding the antimony trioxide to dimethylformamide at a concentration of 30 mass% and uniformly dispersing it was used. As the carbon black, a dispersion liquid thereof prepared in advance by adding the carbon black to dimethylformamide at a concentration of 30 mass% and uniformly dispersing it was used. The obtained spinning solution was extruded into a 50 mass% aqueous solution of dimethylformamide and was thus coagulated, and then the coagulated filaments was washed with water, dried, drawn, and cut to produce modacrylic fibers A. The obtained modacrylic fibers A had a single fiber fineness of 1.7 dtex, a strength of 3.2 cN/dtex, an elongation of 20%, and a cut length of 51 mm. The content of the carbon black with respect to the total mass of the modacrylic fibers A was 8.33 mass%, and the hue was black.
Modacrylic fibers B were obtained in the same manner as in Production Example A, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of antimony trioxide and 2.4 parts by mass of carbon black with respect to 100 parts by mass of the modacrylic resin. The obtained modacrylic fibers B had a single fiber fineness of 1.7 dtex, a strength of 2.0 cN/dtex, an elongation of 30%, and a cut length of 51 mm. The content of the carbon black with respect to the total mass of the modacrylic fibers B was 2.14 mass%, and the hue was black.
Modacrylic fibers C were obtained in the same manner as in Production Example A, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of antimony trioxide and 0.05 parts by mass of carbon black with respect to 100 parts by mass of the modacrylic resin. The obtained modacrylic fibers C had a single fiber fineness of 1.7 dtex, a strength of 2.5 cN/dtex, an elongation of 30%, and a cut length of 51 mm. The content of the carbon black with respect to the total mass of the modacrylic fibers C was 0.05 mass%, and the hue was light gray.
Modacrylic fibers D were obtained in the same manner as in Production Example A, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of antimony pentoxide (Sb2O5, manufactured by Marubishi Oil Chemical Co., Ltd., which has an average particle diameter of 100 nm) and 0.54 parts by mass of carbon black with respect to 100 parts by mass of the modacrylic resin. As the antimony pentoxide, a dispersion liquid thereof prepared in advance by adding the antimony pentoxide to dimethylformamide at a concentration of 30 mass% and uniformly dispersing it was used. The obtained modacrylic fibers D had a single fiber fineness of 1.7 dtex, a strength of 2.8 cN/dtex, an elongation of 30%, and a cut length of 51 mm. The content of the carbon black with respect to the total mass of the modacrylic fibers D was 0.49 mass%, and the hue was gray.
Modacrylic fibers E were obtained in the same manner as in Production Example A, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of antimony trioxide with respect to 100 parts by mass of the modacrylic resin. The obtained modacrylic fibers E had a single fiber fineness of 1.7 dtex, a strength of 3.2 cN/dtex, an elongation of 30%, and a cut length of 51 mm. The hue was unbleached-white.
Modacrylic fibers F were obtained in the same manner as in Production Example A, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of antimony trioxide and 5 parts by mass of a tin oxide-based infrared absorber (manufactured by Ishihara Sangyo Kaisha, Ltd. under the trade name "ET-521W", which has an average particle diameter of 0.3 µm) with respect to 100 parts by mass of the modacrylic resin. As the tin oxide-based infrared absorber, a dispersion liquid thereof prepared in advance by adding the tin oxide-based infrared absorber to dimethylformamide at a concentration of 30 mass% and uniformly dispersing it was used. The obtained modacrylic fibers F had a single fiber fineness of 1.7 dtex, a strength of 2.8 cN/dtex, an elongation of 30%, and a cut length of 51 mm. The hue was bluish-gray.
Modacrylic fibers G were obtained in the same manner as in Production Example A, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of zinc hexahydroxystannate (ZnSn(OH)6, manufactured by SCL Italia Spa under the trade name "ZinFlam (registered trademark) ZHS", which has an average particle diameter of 1.2 µm) and 0.3 parts by mass of carbon black with respect to 100 parts by mass of the modacrylic resin. As the zinc hexahydroxystannate, a dispersion liquid thereof prepared in advance by adding the zinc hexahydroxystannate to dimethylformamide at a concentration of 30 mass% and uniformly dispersing it was used. The obtained modacrylic fibers G had a single fiber fineness of 1.7 dtex, a strength of 2.6 cN/dtex, an elongation of 25%, and a cut length of 51 mm. The content of the carbon black with respect to the total mass of the modacrylic fibers G was 0.27 mass%, and the hue was gray.
Modacrylic fibers H were obtained in the same manner as in Production Example D, except that a spinning solution was prepared by adding, to the modacrylic resin solution, 10 parts by mass of antimony pentoxide and 4.2 parts by mass of carbon black with respect to 100 parts by mass of the modacrylic resin. The obtained modacrylic fibers H had a single fiber fineness of 1.7 dtex, a strength of 2.0 cN/dtex, an elongation of 30%, and a cut length of 51 mm. The content of the carbon black with respect to the total mass of the modacrylic fibers H was 3.68 mass%, and the hue was black.
The modacrylic fibers A to H, para-aramid fibers a (manufactured by Yantai Tayho Advanced Materials Co., Ltd. under the trade name "Taparan (registered trademark)", which has a single fiber fineness of 1.67 dtex and a cut length of 51 mm, also referred to as "PA-a" hereinafter), para-aramid fibers b (manufactured by Dupont under the trade name "Kevlar (registered trademark)", which has a single fiber fineness of 1.65 dtex, a cut length of 51 mm, also referred to as "PA-b" hereinafter), carbon black-containing meta-aramid fibers (manufactured by Dupont "Nomex (registered trademark) N300", which has a single fiber fineness of 1.65 dtex, a cut length of 51 mm, and a carbon black content of 2.1 mass%, also referred to as "C-MA" hereinafter), cellulose-based fibers a (cotton, which has a single fiber fineness of 2 to 3 dtex and a cut length of 38 mm), and cellulose-based fibers b (lyocell, "Tencel (registered trademark)" manufactured by Lenzing, which has a single fiber fineness of 1.4 dtex and a cut length of 38 mm) were used.
In Production Examples 1 to 8, 10, and 11, the above-described fibers were mixed at ratios in Table 1 shown below, and were spun through ring spinning such that the English cotton counts were as in Table 1 shown below.
In Production Example 9, the above-described fibers were used at a ratio in Table 1 shown below to prepare a uniform blend of staple fibers in the form of a picker-blended sliver, and then staple spun yarn was produced using cotton system processing and air-jet spinning machine. The obtained yarn was single yarn of 21 tex (cotton count No. 28). Then, two sets of single yarn were twisted using a yarn-twisting machine to produce two-folded yarn having a ply twist of 10 tums/inch.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 4 as warp and weft. The number of picks of the warp was 63 picks/inch and the number of picks of the weft was 43 picks/inch. The basis weight of the obtained woven fabric was 6.5 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 5 as warp and weft. The number of picks of the warp was 63 picks/inch and the number of picks of the weft was 43 picks/inch. The basis weight of the obtained woven fabric was 6.3 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 2 as warp and weft. The number of picks of the warp was 80 picks/inch and the number of picks of the weft was 60 picks/inch. The basis weight of the obtained woven fabric was 5.6 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 10 as warp and weft. The number of picks of the warp was 64 picks/inch and the number of picks of the weft was 50 picks/inch. The basis weight of the obtained woven fabric was 6.2 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 11 as warp and weft. The number of picks of the warp was 63 picks/inch and the number of picks of the weft was 43 picks/inch. The basis weight of the obtained woven fabric was 6.5 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 6 as warp and weft. The number of picks of the warp was 63 picks/inch and the number of picks of the weft was 43 picks/inch. The basis weight of the obtained woven fabric was 6.9 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 7 as warp and weft. The number of picks of the warp was 80 picks/inch and the number of picks of the weft was 60 picks/inch. The basis weight of the obtained woven fabric was 5.8 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 3 as warp and weft. The number of picks of the warp was 76 picks/inch and the number of picks of the weft was 54 picks/inch. The basis weight of the obtained woven fabric was 5.5 oz/yd2.
Although an attempt was made to produce a woven fabric with a 2/1 twill weave using the spun yarn of Production Example 1 as warp and weft, a fabric could not be obtained due to low strength of the spun yarn.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 7 as warp and the spun yarn of Production Example 8 as weft. The number of picks of the warp was 90 picks/inch and the number of picks of the weft was 70 picks/inch. The basis weight of the obtained woven fabric was 6.5 oz/yd2.
A woven fabric with a 2/1 twill weave was produced using the spun yarn of Production Example 9 as warp and weft. The number of picks of the warp was 77 picks/inch and the number of picks of the weft was 52 picks/inch. The basis weight of the obtained woven fabric was 6.5 oz/yd2.
The ATPVs and the specific ATPVs of the woven fabrics of the examples and the comparative examples were measured as described above, and the results are listed in Table 2 shown below. In Table 2 shown below, CB means carbon black.
As is clear from the data in Table 2 shown above, in the examples, the spun yarn that mainly included the modacrylic fibers and the cellulose fibers, which can be dyed at low temperatures, and no or a small amount of aramid fibers, which are expensive and require a high temperature when dyed, was used, and therefore, the raw material cost of the fabric and the thermal energy during dyeing could be reduced. In addition, the spun yarn that included the modacrylic fibers I containing the carbon black in an amount of 0.1 mass% to 6.0 mass% in the fibers and the cellulose fibers was used, and therefore, the fabric had favorable arc-resistant protectiveness.
Meanwhile, in Comparative Example 1 in which the blend ratios of the modacrylic fibers and the cellulose fibers were the same as those of Example 1 but the modacrylic fibers contained no carbon black, the fabric had a lower ATPV, a lower specific ATPV, and poorer arc-resistant protectiveness than the fabric of Example 1. Also, in Comparative Example 2 in which the aramid fibers were included in addition to the modacrylic fibers and the cellulose fibers but the modacrylic fibers contained no carbon black, the fabric had a lower ATPV, a lower specific ATPV, and poorer arc-resistant protectiveness. Also, in Comparative Example 3 in which the modacrylic fibers contained the carbon black in an amount of less than 0.1 mass%, the fabric had a lower ATPV, a lower specific ATPV, and poorer arc-resistant protectiveness.
In Comparative Example 4 in which the spun yarn included the modacrylic fibers containing the carbon black in an amount of more than 6.0 mass%, the strength and particularly the uniformity ratio of the spun yarn that included the modacrylic fibers significantly deteriorated due to low strength of the modacrylic fibers. Therefore, when an attempt was made to produce a fabric using this spun yarn, the spun yarn was easy to break, and thus a fabric could not be produced.
The fabric of Comparative Example 5 that was a union fabric produced using two types of spun yarn that included the modacrylic fibers, the cellulose fibers, and the aramid fibers had an ATPV and a specific ATPV as low as those of the fabric of Example 1, and the raw material cost would increase to achieve the same level of arc-resistant protectiveness at the same level. Although the spun yarn that included the aramid fibers used in Example 2 included the aramid fibers in an amount of only a third of the content of the aramid fibers in the spun yarn used in Comparative Example 5, the fabric of Example 2 had a much higher ATPV and specific ATPV than the fabric of Comparative Example 5, which means that using the modacrylic fibers containing the carbon black made it possible to improve the arc-resistant protectiveness while reducing the raw material cost. Also, since two types of spun yarn were used in the fabric of Comparative Example 5, the working process took time, and thus the productivity decreased. In Comparative Example 6 in which the spun yarn was used that included, in an amount of more than 25 mass%, the aramid fibers containing the carbon black, the fabric had favorable arc-resistant protectiveness, but the raw material cost increased due to a large amount of expensive aramid fibers being included, and the color of the fabric was limited due to the mixture ratio of the modacrylic fibers, which can be dyed at low temperatures, being limited.
The present invention preferably encompasses the following embodiments, but is not particularly limited thereto.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.