Fire resistant garments and fabrics having yarns containing polymer blends of meta-aramid and polyvinylpyrrolidone

Abstract

A fire resistant garment and a fire resistant fabric each including a yarn, the yarn comprising: a) 85 to 97 weight percent of a meta-aramid fiber component; and b) 3 to 15 weight percent of a fiber formed from a para-aramid polymer, based on the total amount of a) and b) of the yarn, the meta-aramid fiber component being: Based on the total amount of the following i) and ii) in the meta-aramid fiber constituent, i) fibers formed from 50 to 100 weight percent of a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, the polymer blend comprising 88 to 95 weight percent of the meta-aramid polymer and 5 to 12 weight percent of the PVP polymer; ii) 0 to 50 weight percent of a fiber formed solely from meta-aramid polymer; , fire resistant clothing, and fire resistant fabric.

Description

[Technical field]

[0001] FIELD OF THE PRESENT APPLICATION. The present invention relates to flame-resistant garments that have a surprising improvement in predicted protection when exposed to a flame, such as a flash fire. The present invention also relates to fire-resistant fabrics that may be used in such garments that have a surprising reduction in dimensional shrinkage in a flame. This improvement in protection is surprising, in part because it is achieved by replacing fibers formed solely from meta-aramid polymers with fibers formed from a blend of meta-aramid polymers and polyvinylpyrrolidone (PVP) polymers. Although fibers formed solely from meta-aramid polymers are known to be fire resistant, the additive PVP polymer is not considered a fire resistant polymer. [Background technology]

[0002] Description of the Related Art: U.S. Patent Nos. 7,744,999; 8,069,642; and 8,133,584, all to Zhu, disclose textile compositions with improved explosive flame protection such that the wearer experiences less than 65 percent predicted body burns when exposed to a 4-second explosive flame exposure according to ASTM F1930. Furthermore, the minimum performance required for explosive flame protective clothing according to the NFPA 2112 standard is less than 50 percent body burns from a 3-second flame exposure. Since explosive flames are a very real threat to workers in some industries and it is impossible to fully predict how long an individual will be engulfed in flame, any improvement in explosive flame performance of protective clothing fabrics and garments has the potential to save lives. Explosive flames represent one of the most extreme types of thermal threats that workers can experience, and such threats are much more severe than mere flame exposure. Thus, firefighters, factory workers, and others who may be exposed to flames need protective clothing and equipment made from fire and heat resistant fibers, and any improvement in the effectiveness of such equipment is welcome. Summary of the Invention [Means for solving the problem]

[0003] The present invention relates to a fire resistant garment comprising a fire resistant fabric comprising a yarn, the yarn comprising: Based on the total amount of the following a) and b) in this yarn, a) 85 to 97 weight percent of a meta-aramid fiber component; b) 3 to 15 weight percent of fibers formed from a para-aramid polymer; Including, Meta-aramid fiber components are: Based on the total amount of the following i) and ii) in the meta-aramid fiber constituent, i) fibers formed from 50 to 100 weight percent of a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, the polymer blend comprising 88 to 95 weight percent of the meta-aramid polymer and 5 to 12 weight percent of the PVP polymer; ii) 0 to 50 weight percent of a fiber formed solely from meta-aramid polymer; This relates to fire-resistant clothing.

[0004] The present invention also provides a fire resistant fabric comprising a yarn, the yarn comprising: Based on the total amount of the following a) and b) in this yarn, a) 85 to 97 weight percent of a meta-aramid fiber component; b) 3 to 15 weight percent of fibers formed from a para-aramid polymer; Including, Meta-aramid fiber components are: Based on the total amount of the following i) and ii) in the meta-aramid fiber constituent, i) fibers formed from 50 to 100 weight percent of a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, the polymer blend comprising 88 to 95 weight percent of the meta-aramid polymer and 5 to 12 weight percent of the PVP polymer; ii) 0 to 50 weight percent of a fiber formed solely from meta-aramid polymer; It also relates to a fire resistant fabric. [Brief description of the drawings]

[0005] [Figure 1] Photographs of a garment of the present invention and a control garment, respectively, showing flame damage after 4 seconds of exposure to flame using a thermal mannequin test apparatus, where the lighter areas of the garment are areas damaged by the flame. [Diagram 2] Photographs of a garment of the present invention and a control garment, respectively, showing flame damage after 5 seconds of exposure to flame using a thermal mannequin test apparatus, where the lighter areas of the garment are areas damaged by the flame. [Diagram 3]1 is a graph of measured flame shrinkage for 3, 4, and 5 second exposures on a woven fabric in which 100% of the meta-aramid fiber component in the fabric is fiber formed solely from a meta-aramid polymer (specifically, poly(metaphenylene isophthalamide)) without polyvinylpyrrolidone (PVP) compared to a woven fabric in which 100% of the meta-aramid fiber component in the fabric is fiber formed from a blend of a meta-aramid polymer (specifically, poly(metaphenylene isophthalamide)) and a PVP polymer. Included in this graph is a dotted line showing the expected performance of a woven fabric formed from a blend of these two fibers, i.e., a woven fabric in which 50% of the meta-aramid fiber components are fibers formed only from meta-aramid polymers without polyvinylpyrrolidone (PVP), and 50% of the meta-aramid fiber components in the fabric are fibers formed from a blend of meta-aramid polymer and PVP polymer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] The present invention relates to a fire-resistant garment including a fire-resistant fabric including a yarn, the yarn including a) 85 to 97 weight percent of a meta-aramid fiber component, and b) 3 to 15 weight percent of a fiber formed from a para-aramid polymer, based on the total amount of the following a) and b) in the yarn. The meta-aramid fiber component includes i) 50 to 100 weight percent of a fiber formed from a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, and ii) 0 to 50 weight percent of a fiber formed only from a meta-aramid polymer, based on the total amount of the following i) and ii) in the meta-aramid fiber component. Specifically, the polymer blend includes 88 to 95 weight percent of a meta-aramid polymer and 5 to 12 weight percent of a PVP polymer.

[0007] It has been discovered that fire-resistant garments formed from meta-aramid fibers comprising a polymer blend of meta-aramid polymer and polyvinylpyrrolidone (PVP) polymer as described herein provide surprisingly high predicted total body burn protection in a fire event when compared to garments formed from meta-aramid fibers not comprising the meta-aramid polymer / PVP polymer blend, otherwise known herein as fibers formed solely from meta-aramid polymer. Specifically, the phrase "fibers formed solely from meta-aramid polymer" means that the fiber comprises meta-aramid polymer but not a polymer blend of meta-aramid polymer and PVP polymer; the fiber may comprise other non-polymeric components such as additives, pigments, and the like, and may comprise other blend polymers, so long as the fire-resistant properties of the meta-aramid polymer are not compromised. Preferably, the only polymeric component in a fiber formed exclusively from meta-aramid polymer is meta-aramid polymer, and most preferably, the only polymeric component in a fiber formed exclusively from meta-aramid polymer comprises poly(metaphenylene isophthalamide), which may be in the form of a poly(metaphenylene isophthalamide) homopolymer.

[0008] One method of determining the predicted performance of a garment in a flame event is through the use of an instrumented thermal mannequin, such as that known as the DuPont™ Thermo-Man® thermal mannequin. Such an apparatus includes multiple sensors on the surface of the mannequin that can record temperature at multiple points on the surface of the mannequin during a flame event. To test the flame performance of a garment, a thermal mannequin wearing the garment is engulfed in flame for a period of time using multiple flame nozzles that surround the mannequin. The sensors record the temperature history at various points on the surface of the mannequin, and this data is used to calculate the predicted total body burn (burn injury). The test is performed to test method ASTM F1930 (2018). NFPA Standard 2112 requires testing of garments to ASTM F1930(2018) with a flame exposure time of 3 seconds, however, ASTM F1930 may be performed with longer flame exposure times (e.g., 4 or 5 seconds) to reflect a more severe flame event, if desired.

[0009] In some embodiments, the fire resistant garment comprises a fabric having a composition as described herein and a basis weight of 135 to 270 grams per square meter (4 to 8 ounces per square yard). Fabric weights below about 135 gpm (4 osy), especially when used in single layer garments, may not be strong enough to provide the desired protection in typical garments used by workers. Fabric weights above about 270 gpm (8 osy) in single layer garments become uncomfortable to wear. Even higher basis weights, such as 410 gpm (12 osy), provide fire protection, but as the weight of the fabric increases, other issues such as stiffness and breathability, as well as the possibility of heat stress for the worker, increase, so that higher basis weights are only desirable in the most hazardous environments or in multi-layer systems used, for example, in firefighter coats and pants.

[0010] In some embodiments, a fabric having a composition described herein weighing 4 to 8 ounces per square yard provides a fire resistant, single layer garment having a predicted total body burn performance for a 3 second exposure as measured by ASTM F1930(2018) that is at least 20 percent lower than a garment formed from an equal weight of a control fabric having the same proportions of meta-aramid fiber component and para-aramid fiber as described in a) and b), where the meta-aramid fiber component of the control fabric is a fiber formed only from meta-aramid polymer and does not include a fiber formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP).

[0011] In another embodiment, a fabric having a composition as described herein weighing 4 to 8 ounces per square yard provides a fire resistant, single layer garment having a predicted total body burn performance for a 4 second exposure as measured by ASTM F1930(2018) that is at least 15 percent lower than a garment formed from an equal weight of a control fabric having the same proportions of meta-aramid fiber component and para-aramid fiber as described in a) and b), wherein the meta-aramid fiber component of the control fabric is a fiber formed only from meta-aramid polymer and does not include a fiber formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP).

[0012] In yet another embodiment, 4 to 8 ounces per square yard of this fabric having a composition as described herein results in a fire resistant single layer garment having a predicted total body burn performance for a 5 second exposure as measured by ASTM F1930(2018) that is at least 10 percent lower than a garment formed from an equal weight of a control fabric having the same proportions of meta-aramid fiber component and para-aramid fiber as described in a) and b), wherein the meta-aramid fiber component of the control fabric is a fiber formed only from meta-aramid polymer and does not include a fiber formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP).

[0013] FIG. 1 is a photograph of flame damage to two garments 10 and 15 after 4 seconds of exposure to flame using a thermal manikin test apparatus (DuPont™ Thermo-Man® thermal manikin), where the light areas of the garments are areas damaged by the flame. Garment 10 is an example of flame damage to a garment of the present invention, where the meta-aramid fiber component comprises fibers formed from a polymer blend of meta-aramid polymers described herein and polyvinylpyrrolidone (PVP) polymer. Pictured alongside 10 is a control garment 15, where the meta-aramid fiber component is only meta-aramid fibers and does not include fibers formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP). Before testing, both garments were the same size. After testing, as shown, garment 10 was much less damaged and had significantly less fire shrinkage than control garment 15. Garment 15 has a high percentage of bright areas indicating extensive fire damage and the fire contraction of this garment is much more severe than that of garment 10.

[0014] Similarly, FIG. 2 is a photograph of the flame damage to two garments 20 and 25 after 5 seconds of exposure to flame, also using a thermal manikin test apparatus (DuPont™ Thermo-Man® thermal manikin), with the lighter areas of the garments again being areas damaged by the flame. Garment 20 is an example of flame damage to a garment of the present invention, where the meta-aramid fiber component comprises fibers formed from a polymer blend of meta-aramid polymers and polyvinylpyrrolidone (PVP) polymers as described herein. Pictured alongside 20 is a control garment 25, where the meta-aramid fiber component is only meta-aramid fibers and does not include fibers formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP). Prior to testing, both garments were the same size. After testing, as shown, garment 20 was much less damaged and had significantly less fire shrinkage than control garment 25. Garment 25 has a high percentage of bright areas indicating widespread flame damage, and the flame shrinkage of this garment is much more severe than that of garment 20. Also, both garments 20 and 25 exposed to a 5 second flame event show more damage than garments 10 and 15 of Figure 1 exposed to a 4 second flame event, indicating that even 1 second exposure to flame can be significant.

[0015] The yarns used in the fire resistant garments and fabrics include a) a meta-aramid fiber component and b) fibers formed from a para-aramid polymer, which may further include i) fibers comprising a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, and ii) fibers formed only from meta-aramid polymer (i.e., meta-aramid fibers without a meta-aramid polymer / PVP polymer blend).

[0016] As used herein, "aramid" means a polyamide in which at least 85% of the amide (-CONH-) linkages are directly attached to two aromatic rings. A meta-aramid polymer is an aramid polymer in which the amide linkages are meta to each other. A para-aramid polymer is an aramid polymer in which the amide linkages are para to each other. With this aramid, non-polymeric additives can be used, and copolymers can be used having up to about 10 percent of other diamines replacing the diamines of the aramid, or up to about 10 percent of other diacid chlorides replacing the diacid chlorides of the aramid. Suitable aramid fibers are described in Man-Made Fibers-Science and Technology, Volume 2, Section titled Fiber-Forming Aromatic Polyamides, page 297, W. Black et al., Interscience Publishers, 1968. Aramid fibers are also described in U.S. Patent Nos. 3,869,429, 3,819,587, 3,354,127, and 3,094,511.

[0017] The fire resistant garment, or the fire resistant fabric used in the fire resistant garment, includes a) ii) yarns having a meta-aramid fiber component (i.e., fibers that include meta-aramid polymers but do not include blends of meta-aramid polymers / PV polymer blends) that may include fibers formed exclusively from meta-aramid polymers. One such meta-aramid polymer is poly(metaphenylene isophthalamide) (MPD-I), with homopolymer poly(metaphenylene isophthalamide) (MPD-I) being the preferred meta-aramid polymer. Useful meta-aramid-containing fibers (e.g., MPD-I-containing fibers) have a Limiting Oxygen Index (LOI) of about 26 or greater. Various processes for producing fibers formed exclusively from meta-aramid polymers (e.g., fibers that include MPD-I or consist of MPD-I homopolymers) are described, for example, in U.S. Pat. Nos. 3,063,966 and 5,667,743. Additional useful methods for producing meta-aramid fibers, such as MPD-I containing fibers, include U.S. Patent Nos. 7,771,636, 7,771,637, 7,771,638, 7,780,889, and 7,998,575, which disclose dry spinning of meta-aramid filaments using a spin cell having a heated gas atmosphere, where heated gas is supplied to the spin cell to remove the solvent.

[0018] The fire resistant garment, or fire resistant fabric used in the fire resistant garment, comprises b) 3 to 15 weight percent of a yarn comprising a fiber formed from a para-aramid polymer. In some embodiments, the yarn used in the fire resistant garment and fabric comprises 3 to 7 weight percent of a fiber formed from a para-aramid polymer. One preferred fiber formed from a para-aramid polymer is a fiber comprising or consisting of a poly(paraphenylene terephthalamide) (PPD-T) polymer. Useful PPD-T-containing fibers have a limiting oxygen index (LOI) greater than 26. In some embodiments, the para-aramid polymer used to form the para-aramid fiber consists of a poly(paraphenylene terephthalamide) (PPD-T) homopolymer. Various processes for producing para-aramid fibers (e.g., fibers containing PPD-T or consisting of PPD-T homopolymer) are described, for example, in U.S. Pat. Nos. 3,414,645, 3,767,756, 3,869,429, and 3,869,430.

[0019] The fire resistant garment, or fire resistant fabric used in the fire resistant garment, includes a) a yarn having a meta-aramid fiber component, the fiber including a polymer blend of i) a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer. As used herein, polyvinylpyrrolidone polymer or PVP polymer refers to a polymer resulting from the linear polymerization of monomer units of N-vinyl-2-pyrrolidone and may include minor amounts of comonomers that may be present in concentrations that do not interfere with the blending of the PVP polymer with the meta-aramid polymer. The molecular weight of the PVP polymer ranges from about 5000 to about 1,000,000 grams per mole. Very high molecular weight PVP produces a high viscosity spin dope. In many embodiments, PVP polymers having a molecular weight of about 10,000 to about 360,000 are preferred. PVP polymers are not fire resistant polymers because they burn in air.

[0020] One method of producing fibers from a polymer blend of meta-aramid polymer and polyvinylpyrrolidone (PVP) polymer is to form a first isotropic polymer solution of the meta-aramid polymer in a first solvent and a second isotropic solution of the PVP polymer in a second solvent, and then combine the two isotropic polymer solutions to form a single polymer spinning solution having a blend of the two polymers. Optionally, the polymer solutions may include inorganic salts, such as chlorides or bromides having cations selected from the group consisting of calcium, lithium, magnesium, or aluminum. Calcium chloride or lithium chloride salts are preferred. As used herein, the word "salt" is meant to include compounds that increase the solubility of the polymer in the selected solvent or that help provide a stable spinning solution, and to exclude any additives (especially fire-resistant additives) that may be salts but are added simply to increase the limiting oxygen index of the polymer. The salts may be added as chlorides or bromides, or may be generated by neutralizing the by-product acids from the polymerization of aramid by adding calcium, lithium, magnesium, or aluminum oxides or hydroxides to the polymerization solution. The desired salt concentration may also be achieved by adding halides to the neutralization solution to increase the salt content resulting from neutralization to the salt content desired for spinning.

[0021] The solvent is preferably selected from the group consisting of solvents that also function as proton acceptors (e.g., dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), and the like). Dimethylacetamide (DMAc) is one of the preferred solvents. Preferably, the solvent used in each of the separate meta-aramid polymer solutions and the PVP polymer solutions is the same solvent, which is preferably DMAc. Preferably, each of the separate meta-aramid polymer solutions and the PVP polymer solutions is an isotropic solution.

[0022] When the meta-aramid polymer solution is formed from MPD-I and DMAc, preferably the polymer solution further comprises at least 4 percent by weight of an inorganic salt to improve the stability of the polymer solution. Generally, no additional stability additives are required for polymer solutions formed from PVP and DMAc.

[0023] One preferred method of combining the two polymer solutions (each polymer solution formed using the same solvent) is by injecting the PVP polymer solution into the centerline of the pipe carrying the meta-aramid polymer solution with a gear pump, followed by mixing the two polymer solutions with a static mixer. This forms a fiber-spinnable isotropic polymer solution in which the PVP polymer solution is dispersed in the continuous meta-aramid polymer solution. The gear pump can be used to control the amount of PVP polymer solution added to the meta-aramid polymer solution, thereby controlling the blend concentration of PVP polymer in the meta-aramid polymer in the final fiber.

[0024] The spinning solution is then extruded through a spinneret having multiple spinneret holes to form doped filaments, followed by removal of the solvent, washing, drying, and optional other treatments such as heat treatments known in the art to form continuous filaments.

[0025] One preferred method of extruding or spinning filaments to obtain the desired fibers comprising a blend of meta-aramid and PVP polymers is by "dry spinning" as in the dry spinning of meta-aramid or MPD-I filaments described herein above. The process of "dry spinning" filaments is known in the art and involves extruding a polymer solution through a spinneret into a chamber known as a spin cell that has a heated gas atmosphere, including an inert gas such as nitrogen. The spinneret holes form a continuous stream of doped filaments, and as the doped filaments move through the spin cell, the heated gas atmosphere removes most of the solvent from the doped filaments, leaving behind semi-solid filaments with sufficient physical integrity to be further processed. After the formation of the semi-solid filaments, they are treated with additional liquids to cool the filaments and, in some cases, further extract the solvent from the filaments. Subsequent washing, drawing, and heat treatments can further extract the solvent from the filaments in the yarn and develop any desired fiber properties. The filament is then wound onto a bobbin as a continuous filament, preferably having a dense center (i.e., a dense cross section) with no discernible voids, and the filament can then be cut, if desired, into staple fibers having a dense, stiff cross section.

[0026] The fire resistant garment, or the fire resistant fabric used therein, comprises a) a yarn comprising 85-97 weight percent of a meta-aramid fiber component. The meta-aramid fiber component can consist solely of fibers formed from a polymer blend of a meta-aramid polymer and a PVP polymer, or the meta-aramid fiber component is a blend of fibers comprising fibers formed from a polymer blend of a meta-aramid polymer and a PVP polymer, and fibers comprising a meta-aramid polymer, but not a polymer blend of a meta-aramid polymer and a PVP polymer. In some embodiments, the fire resistant garment, or the fire resistant fabric used therein, comprises a yarn comprising a) 93-97 weight percent of a meta-aramid fiber component, and b) 3-7 weight percent of a fiber formed from a para-aramid polymer.

[0027] The meta-aramid fiber components are: Based on the total amount of the following i) and ii) in the meta-aramid fiber constituent, i) fibers formed from 50 to 100 weight percent of a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, the polymer blend comprising 88 to 95 weight percent of the meta-aramid polymer and 5 to 12 weight percent of the PVP polymer; ii) 0 to 50 weight percent of a fiber formed solely from meta-aramid polymer; Includes.

[0028] In some other embodiments, the meta-aramid fiber component i) comprises a fiber formed from a polymer blend of 90-93 weight percent meta-aramid polymer and 7-10 weight percent PVP polymer. In some embodiments, the meta-aramid fiber component i) then amounts to 100 weight percent of a fiber formed from 88-95 weight percent meta-aramid polymer and 5-12 weight percent PVP polymer, and in some embodiments, the 100 weight percent of the fiber formed from a polymer blend of 90-93 weight percent meta-aramid polymer and 7-10 weight percent PVP polymer.

[0029] In some other embodiments, the meta-aramid fiber component ii) may further include modacrylic fiber, fire resistant rayon fiber, lyocell fiber, or mixtures thereof, in addition to fibers formed solely from meta-aramid polymer. For purposes of calculating the weight percent for the meta-aramid component ii), the amount of meta-aramid fiber component ii) is understood to be the total amount of fiber formed solely from meta-aramid polymer plus the total amount of any modacrylic fiber, fire resistant rayon fiber, or lyocell fiber present in ii).

[0030] In some embodiments where the meta-aramid fiber component ii) includes both fibers formed exclusively from meta-aramid polymer and one or more other fibers, the fibers formed exclusively from meta-aramid polymer are a minority component of ii), i.e., in these embodiments, less than 50 weight percent of ii) are fibers formed exclusively from meta-aramid polymer, meaning that less than 25 weight percent of the total amount of i) and ii) in the meta-aramid component are fibers formed exclusively from meta-aramid polymer.

[0031] In some embodiments where the meta-aramid fiber component ii) includes both fibers formed only from meta-aramid polymers and modacrylic fibers, at least 60 weight percent of ii) is modacrylic fiber. In this embodiment, ii) includes 1 to 40 weight percent of fibers formed only from meta-aramid polymers and 60 to 99 weight percent of modacrylic fiber. In one preferred embodiment, ii) includes 20 to 40 weight percent of fibers formed only from meta-aramid polymers and 60 to 80 weight percent of modacrylic fiber.

[0032] In yet another embodiment in which the meta-aramid fiber component ii) includes both fibers formed only from meta-aramid polymers and either fire-resistant (FR) rayon fibers, or lyocell fibers, or a mixture of fire-resistant rayon and lyocell fibers, at least 40 weight percent of ii) is FR rayon fibers, lyocell fibers, or a mixture thereof. In this embodiment, ii) includes 1 to 60 weight percent of fibers formed only from meta-aramid polymers and 40 to 99 weight percent of FR rayon fibers, lyocell fibers, or a mixture thereof. In a preferred embodiment, ii) includes 20 to 60 weight percent of fibers formed only from meta-aramid polymers and 40 to 80 weight percent of FR rayon fibers, lyocell fibers, or a mixture thereof.

[0033] Thus, it is understood that there are embodiments in which the meta-aramid fiber component includes i) and ii), the i) fiber is present in an amount of 50 weight percent to less than 100 weight percent, and at the same time, the ii) fiber is present in an amount of more than 0 weight percent to 50 weight percent. Furthermore, it is understood that the ii) fiber can be formed from one or more meta-aramid polymers, but none of these meta-aramid polymers contain any PVP polymer, and they are PVP polymer free. Preferably, ii) is a fiber formed from a single meta-aramid polymer, and this preferred single meta-aramid polymer is poly(metaphenylene isophthalamide), preferably a poly(metaphenylene isophthalamide) homopolymer.

[0034] In yet another embodiment, the fire resistant garment, or the fire resistant fabric used in the fire resistant garment, is a yarn, comprising, based on the total amount of a), b), and c) in the yarn: a) 85 to 97 weight percent of a meta-aramid fiber component; b) 3 to 15 weight percent of fibers formed from a para-aramid polymer; c) 1 to 3 weight percent of antistatic fibers; The yarn includes:

[0035] Additionally, all possible features and explanations relating to the various embodiments including a) and b) described herein above are intended to apply equally to the embodiments including a), b), and c), but are not repeated herein in order to reduce redundancy.

[0036] One suitable antistatic fiber is a melt spun thermoplastic antistatic fiber such as a carbon core nylon fiber described in U.S. Pat. No. 4,612,150 to De Howitt and / or U.S. Pat. No. 3,803,453 to Hull.

[0037] In some preferred embodiments, the fire-resistant fabric used in the fire-resistant garment is a colored, dyed, or mock-dyed fabric. Optionally, the crystallinity level of meta-aramid fibers can be increased by chemical treatment, which in some embodiments includes coloring, dyeing, or mock-dying the fibers before being incorporated into the fabric. Some such chemical treatment methods are disclosed, for example, in U.S. Pat. Nos. 4,668,234; 4,755,335; 4,883,496; and 5,096,459. Dyeing auxiliaries, also known as dye carriers, can be used to help increase the dye pickup of aramid fibers. Useful dye carriers include aryl ethers, benzyl alcohol, or acetophenone. As used herein, the term "pseudo-dyeing" refers to treating a fabric with liquid chemicals (typically dye assistants or dye carriers as described above) without any dyeing or additional coloring, the pseudo-dyeing treatment is not for the purpose of dyeing or coloring the fabric, but only to stabilize the fabric through the crystallization of the fibers in the yarn.

[0038] Fire resistant garments refer to any type of article or article of clothing designed to be worn on the body for protection from flames. Some such garments are known as turnout coats and turnout gear useful for firefighters, while others are used in industrial applications where workers may be exposed to environments requiring protection from flames. In a preferred embodiment, the fire resistant garment is formed from a fire resistant fabric. As used herein, a fabric is considered fire resistant if it has a char length of 4 inches (100 mm) or less and an afterflame of 2 seconds or less according to the vertical burn test of ASTM D6413-15.

[0039] Fire resistant garments can include coats, jackets, jumpsuits, coveralls, pants, sleeves, hoods, aprons, gloves, and other types of clothing requiring protection from flames. In some applications, such as coveralls, the garments may essentially have one layer of the fire resistant fabric described herein. In other applications, the garments may have multiple layers, such as a firefighter turnout coat, where one or more of the layers of the coat include the fire resistant fabric described herein.

[0040] Fire resistant garments may be manufactured from the fire resistant fabric using any method suitable for producing the desired type of garment. For example, in the case of a single layer coverall, a preferred pattern is used as a guide to cut layers of the fire resistant fabric to produce pieces for forming the various portions of the garment. The pieces are then joined together, typically by sewing, to form the actual garment. Typically, in industrial production, many layers of fabric are layered on a cutting table and then cut at once to form multiple pieces for multiple garments, which are then individually assembled and sewn to produce multiple garments. More complex garments, such as firefighter turnout coats, require multiple layers of protective material, but are manufactured in much the same manner. In such multi-layer garments, the fire resistant fabrics described herein have particular application in either the inner layer or the exterior shell.

[0041] "Fabric" means any woven or knitted layer structure formed from yarn. "Woven" fabric means a fabric that is typically formed on a loom by interweaving warp or lengthwise yarns with weft or crosswise yarns to produce any woven fabric, such as plain weave, houndstooth weave, basket weave, satin weave, twill weave, etc. Plain and twill weaves are believed to be the most common weaves used in the industry and are preferred in many embodiments. "Knitted" refers to structures that can be produced by connecting a series of loops of one or more yarns by needles or wires, such as warp knit (e.g., tricot, Milanese, or raschel) and weft knit (e.g., circular or flat). Often, to produce knitted fabrics, spun staple yarns are fed to a knitting machine that converts the yarn into fabric. If desired, multiple ends or yarns can be fed into the knitting machine either twisted or single, i.e., a bundle of yarns or a twisted bundle can be fed into the knitting machine simultaneously and knitted into a fabric or into a garment, including a fabric, such as a glove, using conventional techniques. The tightness of the knitting can be adjusted to meet any particular requirement. Single jersey knits and terry knits can offer a combination of properties that are highly effective for protective clothing.

[0042] "Yarn" means a collection of fibers spun or twisted together to form a continuous strand. As used herein, yarn generally refers to what is known in the art as a single yarn, which is the simplest strand of textile material suitable for operations such as weaving and knitting; or to a ply yarn or plied yarn. Spun staple yarns may be made from staple fibers that have some twist. If there is twist in a single yarn, it is all in the same direction. As used herein, the phrases "plied yarn" and "twisted yarn" refer to two or more yarns, which may be used interchangeably, i.e., single yarns that are twisted or twisted together. Typically, when two single yarns are twisted together to form a ply yarn, the twist direction of the ply yarn is opposite to that of the single yarn.

[0043] For the purposes of this specification, the term "fiber" is defined as a relatively flexible, macroscopically uniform body having a large ratio of its length to the width of its cross-sectional area perpendicular to its length. The cross-section of the fiber can be any shape, depending on the polymer and its processing, but is typically round or bean-shaped. Such fibers also preferably have a generally dense cross-section for sufficient strength in textile applications, i.e., the fibers preferably have no discernible voids or a large amount of undesirable voids. Fibers obtained directly from the filament spinning process and typically collected in a bobbin of a package are referred to as continuous fibers or filaments. Such continuous fibers or filaments can be converted into short lengths called staple fibers, which refers to fibers that have been cut to a desired length or cut by stretching. Staple fibers have a low ratio of their length to the width of their cross-sectional area perpendicular to their length when compared to continuous filaments. Man-made staple fibers are cut or produced to lengths suitable for processing in spinning equipment for, for example, cotton, wool, or worsted yarns. The staple fibers may have (a) a substantially uniform length, (b) variable or random length, or (c) a substantially uniform distribution of lengths.

[0044] In some embodiments, the fibers have a linear density of 1 to 3 dtex (0.9 to 2.7 denier), which is a particularly useful fiber size for the manufacture of woven and knitted fabrics. This linear density range essentially results in fibers with a minimum cross-sectional diameter measured at any point on the fiber of greater than about 5 microns.

[0045] As used herein, a fiber is considered fire resistant if a fabric formed solely from the fiber has a char length of 4 inches (100 mm) or less and an afterflame of 2 seconds or less according to the Vertical Burn Test of ASTM D6413-15. Additionally, as used herein, a polymer, or a fiber formed from the polymer, is considered fire resistant if the Limiting Oxygen Index of the polymer is greater than 21.

[0046] When a blend of various staple fibers is used in the yarn, it is preferred that the blend is a homogeneous blend of staple fibers. This homogeneous blend can be produced by cutter blending strands or tows of various fibers, or by blending various bales of fibers, and other means known in the art for forming homogeneous blends. For example, slivers of two or more different staple fiber types can be blended before or during the spinning of the staple fiber yarn such that the various staple fibers are evenly distributed as a homogeneous blend in the staple yarn bundle.

[0047] In some embodiments, suitable staple fibers have a cut length of 1 to 30 centimeters (0.39 to 12 inches). In some embodiments, suitable staple fibers have a length of 2.5 to 20 cm (1 to 8 inches). In some preferred embodiments, staple fibers produced by short staple processes have a cut length of 6 cm (2.4 inches) or less. In some preferred embodiments, staple fibers produced by short staple processes have a staple fiber length of 1.9 to 5.7 cm (0.75 to 2.25 inches), with staple fiber lengths of 3.8 to 5.1 cm (1.5 to 2.0 inches) being particularly preferred. For long staple, worsted yarn, or wool wool system spinning, fibers having lengths of 16.5 cm (6.5 inches) or less are preferred.

[0048] Staple fibers may be produced by any method. For example, they may be cut from continuous straight fibers using a rotary or guillotine cutter, which results in straight (i.e., no crimp) staple fibers, or may be cut from crimped continuous fibers having a sawtooth-shaped crimp along the length of the staple fiber, preferably with a crimp (or repeat bend) frequency of 8 or less per centimeter. Preferably, the staple fibers have crimps.

[0049] Staple fibers may also be formed by stretch-breaking of continuous fibers, resulting in staple fibers having deformed sections that act as crimps.Stretch-break staple fibers may be produced by breaking a tow or bundle of continuous filaments during a stretch-breaking operation having one or more stretch-break zones of predetermined distances to form a random, variable mass of fibers with an average cut length controlled by break zone adjustment.

[0050] Spun staple yarns may be produced from staple fibers using conventional long and short staple ring spinning processes known in the art. However, the production of the yarns is not intended to be limited to ring spinning, as the yarns may also be spun using air jet spinning, open end spinning, and many other types of spinning that convert staple fibers into usable yarns. Spun staple yarns may also be produced directly by stretch-cutting using a stretch-cut tow-spun staple process. Staple fibers in yarns formed by conventional stretch-cutting processes typically have lengths up to 18 cm (7 inches). However, spun staple yarns produced by stretch-cutting, for example, by methods such as those described in PCT Application WO 0077283, may have staple fibers up to about 50 cm (20 inches) in length. Stretch-cut staple fibers do not usually require crimping, since the stretch-cutting process imparts some crimp to the fibers.

[0051] The present invention further relates to a fire resistant fabric comprising a yarn, the yarn comprising: a) 85 to 97 weight percent of a meta-aramid fiber component; and b) 3 to 15 weight percent of a fiber formed from a para-aramid polymer, based on the total amount of a) and b) in the yarn. In some embodiments, the fire resistant fabric comprises a yarn comprising: a) 93 to 97 weight percent of a meta-aramid fiber component; and b) 3 to 7 weight percent of a fiber formed from a para-aramid polymer. A preferred para-aramid polymer used in the b) fiber in the fire resistant fabric is formed from poly(paraphenylene terephthalamide). The meta-aramid fiber component includes, based on the total amount of the following fibers i) and ii) in the meta-aramid fiber component, i) 50 to 100 weight percent of fibers formed from a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, and ii) 0 to 50 weight percent of fibers formed only from a meta-aramid polymer. Specifically, the meta-aramid fiber component i) includes fibers formed from a polymer blend containing 88 to 95 weight percent of a meta-aramid polymer and 5 to 12 weight percent of a PVP polymer. In some preferred embodiments, the meta-aramid fiber component i) includes fibers formed from a polymer blend containing 90 to 93 weight percent of a meta-aramid polymer and 7 to 10 weight percent of a PVP polymer.

[0052] In some embodiments, the meta-aramid fiber component ii) consists of fibers formed only from meta-aramid polymer. In some embodiments, the meta-aramid fiber component ii) comprises at least two fibers, one of which is a fiber formed only from meta-aramid polymer. In some embodiments, the meta-aramid fiber component ii) can further comprise modacrylic fibers, fire-resistant rayon fibers, lyocell fibers, or mixtures thereof. To calculate the weight percent for the meta-aramid component ii), the amount of the meta-aramid fiber component ii) is understood to be the total amount of fibers formed only from meta-aramid polymer plus the total amount of any modacrylic fibers, fire-resistant rayon fibers, or lyocell fibers present in ii).

[0053] In some of the embodiments, the yarn used in the fabric further comprises c) 1 to 3 weight percent of antistatic fibers, based on the total amount of a), b), and c) below, in the yarn.

[0054] In the meta-aramid fiber component i) comprising fibers formed from a polymer blend of meta-aramid polymer and PVP, the preferred meta-aramid polymer blended with PVP in the fiber is poly(metaphenylene isophthalamide). In the meta-aramid fiber component ii) comprising fibers formed only from meta-aramid polymer, the preferred meta-aramid polymer is poly(metaphenylene isophthalamide), including poly(metaphenylene isophthalamide) homopolymer. In some embodiments, the fire resistant fabric is dyed or pseudo-dyed to enhance the crystallinity of the meta-aramid fiber component described above.

[0055] It is understood that the present fire resistant fabric is useful in the fire resistant garments previously described herein, and possible features and descriptions of the various embodiments of garments, fabrics, or yarns used in the descriptions of the fire resistant garments previously provided herein apply equally to the fire resistant fabrics herein (and vice versa), but are not intended to be repeated here in order to reduce redundancy.

[0056] In some embodiments, the fire resistant fabric has a fire shrinkage that is at least 10% less than that of an equal weight control fabric comprising the same proportions of meta-aramid fiber components a) and para-aramid fibers b) (i.e., a) and b)), the meta-aramid fiber component of the control fabric being fibers formed only from meta-aramid polymers and not including fibers formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP). In some other embodiments, the fire resistant fabric has a fire shrinkage that is at least 20% less than that of an equal weight control fabric comprising the same proportions of meta-aramid fiber components a) and para-aramid fibers b) (i.e., a) and b)), the meta-aramid fiber component of the control fabric being fibers formed only from meta-aramid polymers and not including fibers formed from a polymer blend of meta-aramid and polyvinylpyrrolidone (PVP).

[0057] Test Method The flame shrinkage performance of the fabrics was measured using a modified method based on NFPA 2112-2018, using the method for determining heat transfer performance (HTP). The test procedure and equipment were as described in NFPA 2112 HTP test, with a flame shrinkage of 2.00 cal / cm 21 / 2 sec exposure was required, with the copper disk in the sensor holder being fully visible through the 2 inch square hole in the sample plate. The cut samples of fabric to be tested were 2 inches wide and 10 inches long. For repeatability, three samples were cut in the warp direction and three samples were cut in the weft direction. The length of each sample was measured to the nearest tenth of an inch prior to testing. Each sample was then taped flat onto the sample test plate so that the entire hole was covered. The sample test plate was then placed on the test stand, which was then held on the sample test plate by placing a 10 gram weight on the sample approximately ½ inch from the bottom. The flame exposure time was then entered (in this case the sample was exposed for 3, 4, and 5 seconds) and the sample test plate was attached to the test fixture. The sample was then exposed to the flame, and when the test was complete, the exposed sample was removed from the test plate and remeasured to the nearest tenth of an inch. The flame shrinkage was calculated using the following formula:

number

[0058] The predicted whole-body burn performance of the garments was determined according to ASTM F1930 (2018) using a DuPont™ Thermo-Man® thermal manikin. EXAMPLES

[0059] Example 1 A homogeneous blend of staple fibers in the form of a Picker blend sliver was prepared of 95 weight percent PVP-containing meta-aramid fiber and 5 weight percent para-aramid fiber, the meta-aramid fiber being formed from a polymer blend of 90 weight percent MPD-I homopolymer and 10 weight percent PVP polymer. The para-aramid fiber was formed from PPD-T homopolymer. A spun staple yarn was then formed from the homogeneous blend using a cotton system process and an air jet spinning frame. The resulting yarn was a single yarn of 18.4 tex (32 cotton count). Two single yarns were then twisted together on a twisting machine to form a two-ply yarn with a ply twist of 10 turns per inch.

[0060] This yarn was then used in the warp and weft of a fabric woven on a shuttle loom in a 2×1 twill configuration on the warp side. The greige twill fabric has a construction of approximately 31 ends by 18 picks per cm (77 ends by 52 picks per inch) and a weight of 186 g / m 2 (5.5oz / yd 2 The fabric was then dyed to a basis weight of about 237 g / m 2 (7oz / yd 2 ) was obtained.

[0061] Comparative example A As a control, a homogeneous blend of staple fibers in the form of a Picker blend sliver was prepared similarly to Example 1, except that the blend contained 95 weight percent meta-aramid fiber without any PVP polymer and only MPD-I homopolymer. Five weight percent para-aramid fiber was also formed from PPD-T homopolymer. Example 1 was then repeated using this blend, producing a spun staple yarn, ply yarn, and basis weight of 186 g / m. 2 (5.5oz / yd 2 A fabric was then formed of the same construction, warp face 2×1 twill weave construction, with a basis weight of about 237 g / m2. 2 (7oz / yd 2 ) was obtained.

[0062] Example 2 The woven fabrics of Example 1 and Comparative Example A were then used to form coveralls for irritation testing on a thermal mannequin. The coveralls were formed using the garment sizes and details set forth in ASTM F1930-00 for thermal mannequin testing, and the garments were then individually tested on a DuPont™ Thermo-Man® thermal mannequin according to ASTM F1930-00 to determine performance in an explosive flame. Two garments were formed from the fabric of Example 1 and two garments were formed from the fabric of Comparative Example A.

[0063] FIG. 1 is a side-by-side photograph of a garment of the present invention 10 made from the fabric of Example 1 and a control garment 15 made from the fabric of Comparative Example A, showing flame damage after 4 seconds of exposure to flame using a thermal mannequin test apparatus. The light areas of the garments in the photograph are areas damaged by flame. FIG. 2 is a side-by-side photograph of a garment of the present invention 20 made from the fabric of Example 1 and a control garment 25 made from the fabric of Comparative Example A, showing flame damage after 5 seconds of exposure to flame using a thermal mannequin test apparatus. Again, the light areas of the garments in the photograph are areas damaged by flame. As shown in FIGS. 1 and 2, the coveralls (10, 20) made from the fabric of Example 1 have less visible shrinkage than the coveralls (15, 25) made from the fabric of Comparative Example A. The predicted full-body burn rates of these garments on a DuPont™ Thermo-Man® thermal mannequin are shown in Table 1.

[0064] [Table 1]

[0065] The garment of the present invention using the fabric of Example 1 significantly reduced the rate of body burns in an explosive flame, which is particularly surprising considering that in the garment of the present invention, 10 percent of the fire resistant and more thermally staple meta-aramid polymer in the meta-aramid fiber used in the fabric was replaced with polyvinylpyrrolidone (PVP) polymer, which is a non-fire resistant polymer (i.e., not a fire resistant polymer).

[0066] Example 3 and Comparative Example B Example 1 was repeated using again a homogeneous blend of staple fibers in the form of a Picker blend sliver of 95 weight percent PVP-containing meta-aramid fibers (specifically MPD-I / PVP fibers) and 5 weight percent para-aramid fibers (specifically PPD-T fibers), but the resulting double spun staple yarn was a 16.3 tex (36 cotton count) yarn, which means that the greige twill fabric had a basis weight of 159 g / m 2 (4.7oz / yd 2 The fabric was then dyed to a basis weight of 169.5 g / m 2 (5oz / yd 2 ) dyed fabric was obtained.

[0067] Similarly, Comparative Example A was repeated to form a control fabric using again a homogeneous blend of staple fibers in the form of a Picker blend sliver of 95 weight percent meta-aramid fibers (specifically, only MPD-I) and 5 weight percent para-aramid fibers (specifically, PPD-T fibers) not containing any PVP, but the resulting double spun staple yarn was a 16.3 tex (36 cotton count) yarn and the greige twill fabric had a basis weight of 159 g / m 2 (4.7oz / yd 2 The fabric was then dyed to a basis weight of 169.5 g / m 2 (5oz / yd 2 ) dyed fabric was obtained.

[0068] Samples of both the inventive (Example 3) and control (Comparative Example B) fabrics were then tested for flame induced shrinkage after 4 seconds of exposure to flame using a modified test method disclosed in this specification based on the NFPA 2112 HTP test. The resulting fabric properties are shown in Table 2.

[0069] [Table 2]

[0070] As shown in Table 2, the fabric of the present invention had less fire induced shrinkage (less shrinkage in flame) in both the warp and weft directions compared to the control.

[0071] Example 4 Samples of both the dyed inventive (Example 1) fabric and the dyed (Comparative Example A) fabric were then further tested for their flame shrinkage, again using the modified test method disclosed in this specification based on the NFPA 2112 HTP test, but with varying flame exposure times. FIG. 3 is a graph of the measured flame shrinkage of the fabric for flame exposures of 3, 4, and 5 seconds exposure. Also included in the graph of FIG. 3 is a dotted line representing the predicted performance of a woven fabric formed from the same overall proportions of meta-aramid and para-aramid fibers used in Example 1 and Non-Core Example A, but with a homogeneous blend including 50 weight percent of fibers formed from only MPD-I and 50 weight percent of fibers formed from a polymer blend of 90 weight percent MPD-I polymer and 10 weight percent PVP polymer as the meta-aramid component. The fabrics including fibers formed from the meta-aramid / PVP polymer blends have less flame shrinkage compared to fabrics including fibers without the meta-aramid / PVP polymer.

[0072] Example 5 Example 1 was repeated, except that the intimate blend of staple fibers in the form of a Picker blend sliver contained 93 weight percent PVP-containing meta-aramid fiber (specifically, MPD-I / PVP fiber), 5 weight percent para-aramid fiber (specifically, PPD-T fiber), and the intimate blend further contained 2 weight percent carbon core nylon antistatic fiber. The resulting spun staple yarn was a single yarn of 21 tex (36 cotton count). Two single yarns were then twisted together on a twisting machine to form a two-ply yarn having a ply twist of 10 turns per inch.

[0073] This yarn was then used as the warp and weft of a fabric woven on a shuttle loom in a twill configuration. The greige fabric had a construction of approximately 28 ends by 15 picks per cm (7769 ends by 5244 picks per inch) and a weight of 142 g / m 2 (4.2oz / yd 2 The fabric was then dyed to a basis weight of about 163 g / m 2 (4.8oz / yd 2 ) was obtained.

[0074] Comparative example C Example 5 was repeated to form a control fabric, but the homogeneous blend consisted of 93 weight percent meta-aramid fibers containing only MPD-I polymer and no PVP polymer, 5 weight percent para-aramid fibers (specifically, PPD-T fibers), and 2 weight percent carbon core nylon antistatic fibers. Spun staple yarns and ply yarns were formed similarly to Example 5, with a basis weight of 142 g / m. 2 (4.2oz / yd 2 A plain weave fabric having the same construction as in Example 5 was formed, with a basis weight of about 149 g / m2 (4.4 oz / yd2). The fabric was then dyed in the same manner as in Example 5 to obtain a fabric having a basis weight of about 149 g / m2 (4.4 oz / yd2).

[0075] Example 6 The woven fabrics of Example 5 and Non-Nucleated Example C were then used to form coveralls for thermal manikin flame testing. The coveralls were formed using the garment sizes and details set forth in ASTM F1930-00 for thermal manikin testing, and the garments were then individually tested on a DuPont™ Thermo-Man® thermal manikin according to ASTM F1930-00 for performance in an explosive flame. Three garments were formed from the fabric of Example 5 and three garments were formed from the fabric of Comparative Example C. The data was then averaged to obtain a nominal weight of 153 g / m2. 2 (4.5oz / yd 2 ), and the predicted whole-body burn rates for these garments are shown in Table 3.

[0076] [Table 3] *Nominally 153 g / m 2 (4.5 oz / yd 2 )

[0077] The garment of the present invention using the fabric of Example 5, despite its very low basis weight, significantly reduced the rate of whole body burns in an explosive flame when compared to the control. This is particularly surprising considering that in the garments of the present invention, 10 percent of the fire resistant and more thermally stable meta-aramid polymer in the meta-aramid fibers used in the fabric has been replaced with polyvinylpyrrolidone (PVP) polymer, which is a non-fire resistant polymer (i.e., not a fire resistant polymer).

Claims

1. A fire resistant fabric comprising a yarn, the yarn comprising: Based on the total amount of the following a) and b) in the yarn: a) 85 to 97 weight percent meta-aramid fiber component; b) 3 to 15 weight percent of fibers formed from a para-aramid polymer; Including, The meta-aramid fiber component is Based on the total amount of the following i) and ii) in the meta-aramid fiber constituents: i) fibers formed from 50 to 100 weight percent of a polymer blend of a meta-aramid polymer and a polyvinylpyrrolidone (PVP) polymer, the polymer blend comprising 88 to 95 weight percent of the meta-aramid polymer and 5 to 12 weight percent of the PVP polymer; ii) 0 to 50 weight percent of fibers formed solely from meta-aramid polymer; It is a fire resistant fabric.

2. The yarn is a) 93 to 97 weight percent meta-aramid fiber component; b) 3 to 7 weight percent of fibers formed from a para-aramid polymer; 10. The fire resistant fabric of claim 1, comprising:

3. 10. The fire resistant fabric of claim 1, wherein the meta-aramid fiber component ii) further comprises modacrylic fiber, fire resistant rayon fiber, lyocell fiber, or a mixture thereof.

4. The yarn is Based on the total amount of a), b), and the following c) in the yarn: c) 1 to 3 weight percent antistatic fibers 10. The fire resistant fabric of claim 1, further comprising:

5. 10. The fire resistant fabric of claim 1, wherein the polymer blend of meta-aramid polymer and PVP polymer comprises 90 to 93 weight percent meta-aramid polymer and 7 to 10 weight percent PVP polymer.

6. 10. The fire resistant fabric of claim 1, wherein the meta-aramid polymer is poly(metaphenylene isophthalamide).

7. 10. The fire resistant fabric of claim 1, wherein the para-aramid polymer is poly(paraphenylene terephthalamide).

8. 10. The fire resistant fabric of claim 1, wherein the fabric is dyed or pseudo-dyed.

9. 10. The fire resistant fabric of claim 1, wherein the fabric has a basis weight of 135 to 270 grams per square meter (4 to 8 ounces per square yard).

10. A fire-resistant garment comprising a fire-resistant fabric described in any one of claims 1 to 9.

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