Thermally resistant fiber, yarn, and fabric comprising the same, and method for forming the same

Abstract

A heat-resistant melt-spun fiber comprises a portion of aromatic polyamide, including PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof. The fiber also comprises at least a portion of aliphatic polyamide. This aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber.

Description

Prior Technology

[0001] Protective clothing made from flame-retardant (FR) or heat-resistant fabrics is typically used to protect wearers from potentially hazardous situations. This includes clothing designed for firefighters, military personnel, law enforcement officers, first responders, emergency responders, electrical workers, welders, and workers in industries such as oil drilling and refining, power generation, transportation, construction, metal refining, and manufacturing. Flame-retardant fabrics minimize the risk of injury from exposure to flames, flashes, or arc flashes by resisting ignition, not sustaining flames, not dripping or sticking to the wearer's skin, and having limited thermal shrinkage and conductivity. Additionally, the fabric should not break during flame exposure to prevent direct impact of flames on the wearer's skin. Flame resistance is also required in various non-clothing applications, such as carpets, upholstery, curtains, furniture, wallpaper, seat covers in vehicles (e.g., cars, trains, airplanes, buses, cruise ships), awnings, bulletproof vests / carpet carriers, tents, and firefighting equipment.

[0002] Various strategies can be employed to achieve flame resistance in fabrics. These strategies include using one or more inherently flame-resistant fibers (i.e., fibers prepared from permanently fire-resistant materials whose fire resistance is not altered by abrasion, washing, or erosion), applying chemical flame-retardant treatments or coatings to the fabric, or a combination thereof, where inherently flame-resistant fibers are combined with non-flame-resistant fibers and, where appropriate, fabrics treated with flame-retardant chemicals to enhance heat and flame resistance. Using these strategies, numerous flame-resistant fabrics have been developed for protective clothing and other end uses and applications. For clothing applications and many other applications (such as aircraft seat covers), rigorous testing is required to ensure that the fabrics and the garments made from them comply with industry standards (such as NFPA 2112 and ISO 11612).

[0003] Textiles meeting flame-retardant standards typically include expensive fibers (e.g., DuPont Nomex® inter-aramid) and / or fibers with limited tensile strength (e.g., Kaneka Protex® modified polyacrylonitrile). Additionally, while some fibers exhibit high tensile strength and tear resistance (e.g., DuPont Kevlar® para-aramid), their limited stretch increases the fabric's stiffness and rigidity. Therefore, garments made from such fabrics may be uncomfortable to wear, have limited flexibility, and feel rough or itchy, potentially irritating the skin, especially in warmer climates where wearers are more prone to sweating. Many FR fabrics have lower strength and abrasion resistance than similar non-FR fabrics, resulting in a shorter garment lifespan. In addition, compared to conventional clothing fibers made of polyester (e.g., polyethylene terephthalate) or nylon (e.g., nylon-6,6 or polyamide-6,6), inherently flame-resistant fibers are more difficult to dye and exhibit reduced color fastness, which also shortens the lifespan of clothing.

[0004] A common strategy for improving the comfort or durability of fabrics, or for improving other fabric properties (e.g., colorfastness) that are not desired when using inherent FR fibers or applying flame-retardant chemicals to the fabric, is to include non-FR fibers in the composition. However, in flame-resistance testing and / or burn prediction testing, only limited amounts of such materials can be used without affecting the fabric's performance. For example, Nylon-6,6 fiber has high strength and abrasion resistance, as well as good moisture recovery and elongation that make the fabric comfortable against the skin. In addition, Nylon-6,6 fiber can be easily dyed in high-temperature industrial washing and has good colorfastness, but it will melt and burn when exposed to flame. Therefore, flame-retardant clothing fabrics that meet standards (such as NFPA 2112, NFPA 70E, or ISO 11612) typically include a maximum content of 20% Nylon-6,6 because flame resistance must take precedence over other desired properties such as strength, durability, and comfort.

[0005] Polyamide-based fibers (filaments or staple fibers) with superior heat resistance compared to commercial aliphatic polyamides (such as Nylon-6 (PA6) and Nylon-6,6 (PA66)) and similar strength, abrasion resistance, dyeability, and colorfastness to commercially available PA66 apparel fibers can be incorporated into flame-retardant fabrics at significantly higher loads. This results in more comfortable and durable fabrics that still provide the multi-hazard protection typically required for flame-retardant clothing. By ensuring that such flame-retardant fabrics meet relevant standards or requirements, damage from various risks can be mitigated. These standards include, but are not limited to, objectives aimed at protecting individuals from exposure to: flash fires (e.g., NFPA 2112, ISO 11612), electric arcs (e.g., NFPA 70E, EN 61482-2), welding hazards (e.g., ISO 11611), static electricity (e.g., ISO 1149), chemical splashes (e.g., ISO 13034), molten metal splashes (e.g., ISO 9150), structural fire hazards (e.g., NFPA 1971), and wilderness fire hazards (e.g., NFPA 1977).

[0006] Enhanced fabric comfort can be influenced by several factors, including (but not limited to) increased breathability, weight reduction, increased elasticity, improved moisture control (i.e., the fabric's ability to transfer moisture from the skin and evaporate it from the fabric), improved heat control, a softer hand feel, smoother fabric, and increased drape (i.e., reduced stiffness). Similarly, many aspects of fabric durability affect the lifespan of garments containing that fabric, including (but not limited to) fabric abrasion resistance, tear strength, tensile strength, pilling resistance, colorfastness (e.g., colorfastness to washing, UV exposure, perspiration, rubbing, or bleaching), dimensional stability, and resistance to and release of dirt and stains.

[0007] Some aromatic polyamide fibers possess excellent heat resistance, allowing them to be incorporated into flame-retardant fabrics in a greater proportion than similar fibers containing only aliphatic nylon (e.g., PA6 or PA66). However, pure PA-MXD6 achieves lower tensile strength and abrasion resistance than similar fibers containing only aliphatic nylon. Fibers requiring heat resistance, high strength, and high abrasion resistance are needed. Summary of the Invention

[0008] Various embodiments of the present invention provide a heat-resistant melt-spun fiber comprising a portion of aromatic polyamide, wherein the polyamide comprises PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or a combination thereof. The fiber also comprises at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber.

[0009] Various embodiments of the present invention provide a heat-resistant melt-spun fiber comprising a partially aromatic polyamide, the polyamide being PA-MXD6 and having a relative viscosity (RV) of 2.4 to 2.9 in 96% sulfuric acid (as measured according to ISO 307). The fiber also comprises at least a partially aliphatic polyamide, which is PA66 and has an RV of 65 to 95 as an 8.4 w / w% solution in 90% formic acid (as measured according to ASTM D789). The partially aromatic polyamide comprises 55 wt% to 90 wt% of the total polyamide in the fiber, the at least partially aliphatic polyamide comprises 45 wt% to 10 wt% of the total polyamide in the fiber, and the partially aromatic polyamide and the at least partially aliphatic polyamide together comprise 90 wt% to 100 wt% of the fiber.

[0010] Various embodiments of the present invention provide a heat-resistant melt-spun fiber comprising a partially aromatic polyamide, the polyamide being PA-MXD6 having an RV of 2.4 to 2.9 in 96% sulfuric acid (as measured according to ISO 307) and comprising 55 wt% to 90 wt% of the fiber. The fiber also comprises at least a partially aliphatic polyamide, PA66, comprising 45 wt% to 10 wt% of the fiber and having an RV of 65 to 95 as an 8.4 w / w% solution in 90% formic acid (as measured according to ASTM D789).

[0011] Various embodiments of the present invention provide a yarn comprising heat-resistant fibers or comprising only heat-resistant fibers. The fibers comprise a portion of aromatic polyamide, comprising PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof. The fibers also comprise at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber.

[0012] Various embodiments of the present invention provide a fabric. The fabric comprises yarns containing heat-resistant fibers. The fibers comprise a portion of aromatic polyamide, which includes PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof. The fibers also comprise at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber.

[0013] Various embodiments of the present invention provide methods for forming heat-resistant fibers. The method comprises melt-blending a portion of aromatic polyamide and at least a portion of aliphatic polyamide to form a blend. The method also comprises melt-spinning the blend to form a heat-resistant fiber. The fiber comprises a portion of aromatic polyamide and at least a portion of aliphatic polyamide, wherein the aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber.

[0014] Compared to other heat-resistant fibers and / or yarns and fabrics containing them, the various forms of the present invention offer a variety of advantages. For example, among the various forms, the heat-resistant fibers of the present invention have high tensile strength, which imparts strength and durability to the fabric and thereby extends the lifespan of garments made from this fabric. The heat-resistant fibers can possess physical properties, such as toughness, resilience, and abrasion resistance, that cannot be achieved by fibers formed solely from partially aromatic polyamides (e.g., PA-MXD6 alone).

[0015] Compared to fibers formed from at least a portion of aliphatic polyamides (e.g., PA66), heat-resistant fibers can exhibit increased char formation, reduced dripping tendency during combustion, and reduced total heat release during combustion, wherein the total heat release can be measured by pyrolysis combustion flow calorimetry according to ASTM D7309. In various forms, the heat-resistant fibers of the present invention offer various advantages when blended with other fibers and / or yarns to form flame-resistant fabrics. In various forms, fabrics formed from the heat-resistant fibers of the present invention may possess a certain degree of flame retardancy (e.g., vertical flammability and instrumented human model testing according to ASTM D6413 or ISO 15025 and ASTM F1930 or ISO 13506 respectively), heat resistance, and physical properties (e.g., strength, durability, and such combinations) that cannot be achieved by incorporating 100% partially aromatic polyamide short fibers (e.g., PA-MXD6) and at least 100% partially aliphatic polyamide short fibers (e.g., PA66) into the yarn to form a fabric.

[0016] In various formulations, in addition to improving physical properties, adding at least a portion of aliphatic polyamine to a portion of aromatic polyamine can improve the spinning properties of the fiber, for example, enabling fiber stretching to be initiated at lower temperatures. Adding catalysts and antioxidants, as appropriate, to the polymer melt blend can also improve the physical properties (e.g., toughness) of the fiber.

[0017] In various formulations, the fibers of the present invention exhibit a disproportionately negative impact on char yield and total heat release from at least a portion of the aliphatic polyamine content, rather than a linear weighted average effect on char yield and total heat release from the addition of at least a portion of the aliphatic polyamine to a portion of the aromatic polyamine. Therefore, the various embodiments of the fibers of the present invention possess a combination of good heat resistance (e.g., higher char formation and lower heat release) and good physical properties (e.g., toughness and abrasion resistance) that cannot be predicted based on linear weighted averages. In various formulations, the use of at least a portion of the aliphatic polyamine with higher viscosity (e.g., PA66 with a viscosity greater than or equal to 50 RV or greater than or equal to 65 RV) can be used to further modulate the fiber properties and can result in even greater fiber toughness.

[0018] In various forms, by improving strength, abrasion resistance, and processability while maintaining significant partial improvements in heat release and char formation, the fibers of this invention can be incorporated into fabrics to provide similar flame-retardant benefits as using pure partially aromatic polyamide fibers (e.g., PA-MXD6), without negatively impacting the fabric's level of protection (e.g., protection against flash fire or arc flash exposure burns). Although aliphatic polyamide fibers (e.g., PA66 or PA6) are typically limited to less than 20% of the total fabric to make the fabric self-extinguishing and meet flame-retardant protection requirements, various forms of the fibers of this invention can be incorporated into fabrics at higher percentages (e.g., 30% to 50%) while still enabling the fabric to be self-extinguishing and meet flame-retardant protection requirements, for example, according to NFPA 2112, NFPA 70E, and ISO 11612, ISO 14116, ISO 61482-1-1, ISO 61482-1-2, and ISO 13506 standards.

[0019] In all its forms, the improved heat resistance of the fibers of the present invention is inherent to the polymer composition, and therefore cannot be washed away or abraded as in cases of additives or spot / surface treatments with limited water solubility applied to fibers, yarns, or fabrics. In all its forms, the fibers of the present invention can comfortably conform to the skin, can be dyed / printed using conventional techniques for dyeing / printing polyamide clothing fibers, and are suitable for washing in hot water or using industrial laundry, due to the inherent flame retardancy of the fibers. In all its forms, the fibers of the present invention can regain moisture, making them comfortable to wear (similar to conventional aliphatic nylons, such as N6 or N66), but still dry faster than cellulose fibers. Implementation

[0020] [Cross-reference to related applications] [ ] This application claims priority to U.S. Provisional Patent Application No. 63 / 572,372, filed April 1, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0021] The following detailed reference will be made to certain aspects of the disclosed object. Although the disclosed object will be described in conjunction with the listed technical solutions, it should be understood that the illustrated object is not intended to limit the technical solutions to the disclosed object.

[0022] Throughout this document, values ​​expressed in range format should be interpreted flexibly to include not only the values ​​explicitly listed as range limits, but also all individual values ​​or subranges covered within that range, as if each value and subrange were explicitly stated. For example, the range "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted as including not only about 0.1% to about 5%, but also the individual values ​​(e.g., 1%, 2%, 3%, and 4%) and subranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. Unless otherwise indicated, the statement "about X to Y" has the same meaning as "about X to about Y". Similarly, unless otherwise indicated, the statement "about X, Y, or about Z" has the same meaning as "about X, about Y, or about Z".

[0023] In this document, unless the context clearly indicates otherwise, the terms "a" or "the" are used to refer to one or more. Unless otherwise indicated, the term "or" is used to mean a non-exclusive "or". The statements "at least one of A and B" or "at least one of A or B" have the same meaning as "A, B, or A and B". Furthermore, it should be understood that phrases or terms used herein without further definition are for illustrative purposes only and not for limiting purposes. Any use of section headings is intended to aid reading the document and should not be construed as restrictive; information relating to section headings may appear within or outside that particular section.

[0024] In the methods described herein, actions may be performed in the specific order listed herein. Alternatively, in any of the states disclosed herein, specific actions may be performed in any order without departing from the principles of the invention, unless the time or sequence of operations is explicitly listed. Furthermore, unless explicitly stated in the language of claim, specific actions may be performed individually or the explicit meaning of the technical solution requires so, they may be performed simultaneously. For example, claimed action X and claimed action Y may be performed simultaneously in a single operation, and the resulting process falls within the scope of the claimed process.

[0025] The term “about” as used herein may allow for a degree of variability in a value or range (e.g., within 10%, 5%, or 1% of the value or range limit) and includes a precise stated value or range.

[0026] The term “substantially” as used herein means substantially or substantially, such as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more or 100%. The term "substantially free of" as used herein may mean the absence of or presence of a material in trace amounts such that the amount of material present does not affect the substantial properties of the composition containing the material, thereby the composition comprising about 0 wt% to about 5 wt% (or about 0 wt% to about 1 wt% or about 5 wt% or less or less, equal to or greater than about 4.5 wt%, 4 wt%, 3.5 wt%, 3 wt%, 2.5 wt%, 2 wt%, 1.5 wt%, 1 wt%, 0.9 wt%, 0.8 wt%, 0.7 wt%, 0.6 wt%, 0.5 wt%, 0.4 wt%, 0.3 wt%, 0.2 wt%, 0.1 wt%, 0.01 wt% or about 0.001 wt% or less or about 0 wt%) is the material.

[0027] As used herein, the term "polymer" refers to a molecule having at least one repeating unit and may include copolymers.

[0028] As used herein, the terms "polyamide" and "nylon" are used interchangeably and define a class of thermoplastic polymers. Examples of polyamide or nylon include PA66, PA6, PA10, PA11, PA12, PA46, PA56, PA610, PA1010, PA1012, PA6 / 66, PA66 / D6, PA66 / 6T, PA66 / 6I, PA66 / DI, PA66 / 6T / 6I, PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, and others.

[0029] As used in this article, the term "heat resistance" refers to properties of resistance to combustion, such as those measured by char formation (where more char formation means greater heat resistance), dripping tendency during combustion (where less dripping means greater heat resistance), and heat release during combustion (where less heat release means greater heat resistance).

[0030] As used herein, the terms "flame resistant" or "fire resistant" refer to the property of self-extinguishing flames in their pure form. The material will not continue to burn until it is completely consumed after the flame or heat source is removed.

[0031] As used in this article, the term "FR" indicates fire resistance or flame retardancy.

[0032] As used herein, the terms “flame retardant” or “fire retardant” refer to the property of additives or treatments that increase the heat resistance or flame retardancy of materials. [Heat-resistant fiber.] [ ]

[0033] Various embodiments of the present invention provide a heat-resistant fiber. The fiber comprises a heat-resistant melt-spun fiber containing a portion of aromatic polyamide, the polyamide comprising PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or a combination thereof. The fiber also contains at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber. The fiber is spun from a melt-blended composition comprising a portion of aromatic polyamide and at least a portion of aliphatic polyamide. The melt-blended composition may have the same composition as the heat-resistant melt-spun fiber. The fiber may be heat-resistant or flame-resistant.

[0034] Partially aromatic polyamides may comprise polymers or monomers selected from the group consisting of aromatic diamine monomers, aliphatic diamine monomers, aromatic diacid monomers, aliphatic diacid monomers, and combinations thereof. Partially aromatic polyamides may also comprise copolymers or mixtures of various partially aromatic polyamides. Partially aromatic polyamides may comprise PA-MXD6 (i.e., produced by the condensation polymerization of m-xylyldiamine and adipic acid), PA-PXD6 (i.e., produced by the condensation polymerization of p-xylyldiamine and adipic acid), PA-MXD6 / PXD6 (i.e., produced by the condensation polymerization of m-xylyldiamine, p-xylyldiamine, and adipic acid), or combinations thereof. Partially aromatic polyamides may include PA-MXD6. Partially aromatic polyamides may have any suitable relative viscosity (RV). For example, some aromatic polyamides may have an RV (as measured according to ISO 307) of 1.5 to 4, or 2 to 3.5, or 2.4 to 2.9, 2.45 to 2.85, or less than or equal to 4 and greater than or equal to 1.5 and less than, equal to or greater than 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4 or 3.5 in 96% sulfuric acid. Aromatic polyamides may constitute at least 50 wt% of the fiber, for example, 51 wt% to 99.5 wt%, 55 wt% to 90 wt%, 60 wt% to 80 wt%, or less than or equal to 99.5 wt% and greater than or equal to 50 wt%, and less than, equal to, or greater than 52 wt%, 54 wt%, 56 wt%, 58 wt%, 60 wt%, 61 wt%, 62 wt%, 63 wt%, 64 wt%, 65 wt%, 66 wt%, 67 wt%, 68 wt%, 69 wt%, 70 wt%, 71 wt%, 72 wt%, 73 wt%, 74 wt%, 75 wt%, 76 wt%, 77 wt%, 78 wt%, 79 wt%, 80 wt%, 82 wt%, 84 wt%, 86 wt%, 88 wt%, 90 wt%, 92 wt%, 94 wt%, 96 wt% or 98 wt%.

[0035] The fiber may have a weight ratio of at least 50:50 of partially aromatic polyamide to at least partially aliphatic polyamide, for example, 50:50 to 95.5:0.5, or 51:49 to 95.5:0.5, or 55:45 to 90:10, or 60:40 to 80:20, or less than or equal to 95.5:0.5 and greater than or equal to 50:50, and less than, equal to or greater than 52:48, 54:46, 56:44, 58:42, 60:40, 61:3. 9, 62:38, 63:37, 64:36, 65:35, 66:34, 67:33, 68:32, 69:31, 70:30, 71:29, 72:28, 73:27, 74:26, 75:25, 76:24, 77:23, 78:22, 79:21, 80:20, 82:18, 84:16, 86:14, 88:12, 90:10, 92:8, 94:6, 96:4 or 98:2.

[0036] The total amount of aromatic polyamide and at least aliphatic polyamide in the fiber and / or the total amount of polyamide in the fiber may be 80 wt% to 100 wt%, or 90 wt% to 100 wt%, or 95 wt% to 100 wt%, or less than or equal to 100 wt% and greater than or equal to 80 wt%, and may be less than, equal to or greater than 81 wt%, 82 wt%, 83 wt%, 84 wt%, 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, 99.5 wt%, 99.9 wt%, or 99.99 wt%.

[0037] At least a portion of the aliphatic polyamine may comprise aliphatic polyamines, aliphatic / aromatic polyamine copolymers, or combinations thereof. At least a portion of the aliphatic polyamine may comprise PA66, PA6, PA10, PA11, PA12, PA46, PA56, PA610, PA1010, PA1012, PA6 / 66, PA66 / D6, PA66 / 6T, PA66 / 6I, PA66 / DI, PA66 / 6T / 6I, or combinations thereof, wherein "T" is formed from terephthalic acid (TPA), "D" is formed from 2-methyl-1,5-pentanediamine (MPMD), and "I" is formed from isophthalic acid (IPA). At least a portion of the aliphatic polyamide may comprise a polyamide formed from a combination of monomers (e.g., hexamethylenediamine (HMD), adipic acid (AA), TPA, IPA, MPMD, caprolactam, and two or more of the like). At least a portion of the aliphatic polyamide may comprise PA66 (i.e., Nylon 6,6 or N66 formed by the condensation polymerization of adipic acid and hexamethylenediamine). At least a portion of the aliphatic polyamide as an 8.4 w / w% solution in 90% formic acid may have an RV of 40 to 150, or 50 to 120, or 65 to 95, or greater than or equal to 75, or less than or equal to 150 and greater than or equal to 40, and less than, equal to or greater than 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140 or 145 (as measured according to ASTM D789). At least a portion of the aliphatic polyamide may constitute less than 50 wt% of the fiber, for example, 0.5 wt% to 49.9 wt%, or 10 wt% to 45 wt%, or 20 wt% to 40 wt%, or less than 50 wt% and greater than or equal to 0.5 wt%, and constitute less than, equal to, or greater than 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 42 wt%, 44 wt%, 46 wt% or 48 wt%.

[0038] In various forms, the fiber further comprises flame-retardant additives. These flame-retardant additives can be any suitable additive. For example, they may include halogenated flame-retardant additives, phosphorus-containing flame-retardant additives, inorganic flame-retardant additives, nitrogen-containing flame-retardant additives, non-halogenated flame retardants, polymeric halogenated flame retardants, or combinations thereof. The flame-retardant additives may include non-halogenated flame retardants, polymeric halogenated flame retardants, or combinations thereof, and may include one or more synergists, depending on the circumstances. Flame retardant additives may comprise 0.01 wt% to 25 wt%, 0.01 wt% to 20 wt%, 0.01 wt% to 15 wt%, or 0.1 wt% to 5 wt%, or less than or equal to 25 wt% and greater than or equal to 0.01 wt%, and less than, equal to, or greater than 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, or 44 wt% of the fiber. In other samples, the fiber is substantially free of flame retardant additives; for example, the flame retardant additives may comprise less than 0.01 wt% of the fiber, or 0 wt% to 0.01 wt% of the fiber, or 0 wt% to 0.001 wt% of the fiber.

[0039] The fiber may contain one or more additives, such as antioxidants, fading agents, pigments, stretching agents, other fiber additives, or combinations thereof.

[0040] Compared to the same fiber in which a combination of partially aromatic polyamides and at least partially aliphatic polyamides is replaced by at least partially aliphatic polyamides, this fiber may have improved physical properties. For example, compared to the same fiber in which a combination of partially aromatic polyamides and at least partially aliphatic polyamides is replaced by at least partially aliphatic polyamides, this fiber may have increased char formation, as measured according to ASTM D7309-22. Compared to the same fiber in which a combination of partially aromatic polyamides and at least partially aliphatic polyamides is replaced by at least partially aliphatic polyamides, this fiber may have reduced total heat release, as measured according to ASTM D7309-22.

[0041] Compared to the same fiber in which a combination of partially aromatic polyamide and at least partially aliphatic polyamide is replaced by partially aromatic polyamide, this fiber may have improved physical properties. For example, compared to the same fiber in which a combination of partially aromatic polyamide and at least partially aliphatic polyamide is replaced by partially aromatic polyamide, this fiber may have increased toughness, as measured according to ASTM D1907. Compared to the same fiber in which a combination of partially aromatic polyamide and at least partially aliphatic polyamide is replaced by partially aromatic polyamide, this fiber may have increased abrasion resistance, as measured according to ASTM D3885.

[0042] As measured according to ASTM D4974 (for filaments) or ASTM D2102 (for staple fibers), the fiber may have a shrinkage rate of 2% to 20%, for example, 2% to 16%, or 3% to 10%, or 4% to 7%, or less than or equal to 20% and greater than or equal to 2%, and less than, equal to or greater than 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, or 19.5%.

[0043] As measured according to ASTM D2256, the fiber may have an elongation of 10% to 50%, for example, 15% to 35%, or less than or equal to 50% and greater than or equal to 10%, and less than, equal to or greater than 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, or 48%.

[0044] As measured according to ASTM D1907, the fiber may have a toughness of 4 g / den to 12 g / den, or 5 g / den to 10 g / den, or less than or equal to 12 g / den and greater than or equal to 4 g / den, and less than, equal to or greater than 4.5 g / den, 5 g / den, 5.5 g / den, 6 g / den, 6.5 g / den, 7 g / den, 7.5 g / den, 8 g / den, 8.5 g / den, 9 g / den, 9.5 g / den, 10 g / den, 10.5 g / den, 11 g / den or 11.5 g / den.

[0045] The fiber can be a short fiber, a continuous filament fiber, or a combination thereof. The fiber can be flat or crimped. Crimping can be performed by air-jet crimping, stretch crimping, pin crimping, or a combination thereof. The fiber profile can have any suitable shape, such as circular, ring-shaped, triangular, star-shaped, square, oval, bilobal, trilobal, or flat. [Yarn.] [ ]

[0046] Various embodiments of the present invention provide yarns comprising the heat-resistant melt-spun fibers described herein. The heat-resistant melt-spun fibers comprise a portion of aromatic polyamide, including PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof. The fibers also comprise at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber. The yarn may be heat-resistant or flame-resistant.

[0047] In all varieties, the yarn substantially contains no fibers other than the heat-resistant melt-spun fibers described herein. In other varieties, the yarn may contain one or more other fibers. Other fibers may be FR fibers (i.e., flame-resistant fibers or inherently flame-resistant fibers), heat-resistant fibers, non-FR fibers, or non-heat-resistant fibers. One or more other fibers may be one or more non-FR fibers or non-heat-resistant fibers, such as fibers containing the following: polyurethane, polyethylene, polypropylene, wool, fibrous fibers (e.g., cotton, hemp, flax, jute, ramie, sisal), regenerated fibrous fibers (e.g., viscose, modal, lyocell), cellulose acetate (e.g., Eastman Naia™), cuprammonium (cupro or cupra) fibers, ultra-high molecular weight polyethylene (UHMWPE), antistatic fibers, bicomponent polyesters, polyesters (e.g., PET, PTT, PBT), other nylon fibers (e.g., PA66 or PA6), or combinations thereof.In some morphologies, other fibers are FR fibers (i.e., flame-resistant fibers) or heat-resistant fibers, such as fibers comprising: FR polyester (e.g., Indorama Trevira® CS), FR-resistant ester, FR adhesive, FR rayon (e.g., Lenzing™ FR), FR Lysell, FR cellulose acetate, interpolyarylamine (e.g., DuPont Nomjin) Teijinconex®), p-polyarylamide (e.g., DuPont Kevlar®, Teijin Twaron®), modified polyacrylonitrile (e.g., Kaneka Protex®, Aksa Armora), phenol-formaldehyde resin (e.g., Novoloid), melamine, poly(e.g., paraphenylbenzodioxazole) (PBO), polybenzimidazole (PBI), polysulfonamide (PSA), oxyacrylic acid, partially oxidized acrylic acid, cross-linked acrylic acid, polyoxadiazole, aromatic polyester, aromatic copolymeramide (e.g., Teijin Technora®), polybenzimidazole (PBI), polyoxadiazole (POD) (e.g., Svetlogorsno Arselon and Arselon-S), polybenzooxazole (PBO) (e.g., Toyobo Zylon®), polyamide-imine (e.g., Kermel®), polyimide (e.g., Evonik P84®), phenolic phenolic system, cross-linked acrylonitrile (e.g., PyroTex®, Grupo ADI Tecstar®), oxidized or (Partly oxidized poly (e.g., TECGEN®), polyaryl esters (e.g., Kuraray Vectran™), polysulfonamides (PPS), poly{2,6-diimidazolo[4,5-b:40; 50-e]-extenopyridyl-1,4-(2,5-dihydroxy)extenphenyl} (PIPD), polyether imine (PEI), polyethylene naphthalate (PEN), vinylon (vinalon, vinylon), polytetrafluoroethylene (PTFE), expanded PTFE, or combinations thereof. .

[0048] In woven fabrics or knitted fabrics, the yarn may be spun as continuous filament or compound yarn, tensile fracture or self-short fibers or a combination of filaments and short fibers. The staple fiber may be a tight mixture in which the components are uniformly mixed throughout the yarn. The yarn may comprise a single yarn or two or more individual yarns of any type (e.g., staple fibers, filaments, and the like) in combination by spinning, plying, wiring, wrapping, blending, interweaving, covering, or cored spinning. In addition, other types of yarns comprising ceramic, metal, glass, carbon and / or other types of inorganic yarns may be incorporated to form composite yarns. [Fabric. ] [ ]

[0049] Various embodiments of the present invention provide a fabric comprising the yarn described herein. The yarn comprises heat-resistant fibers containing a portion of aromatic polyamide, the polyamide comprising PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof. The fibers also contain at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber. The fabric may be heat-resistant or flame-retardant.

[0050] The fabric can be any suitable type of fabric. It can be woven, knitted, nonwoven (e.g., spunbond or melt-bonded), or a combination thereof. The fabric may be coated or laminated depending on the specific end application. Nonwoven fabrics include self-carding webs, meltblown processes, spunbond processes, and those combined by water-jet entanglement.

[0051] The yarn can be a main yarn. The fabric can further include at least one additional yarn that is compositionally different from the main yarn. The additional yarn is different from the main yarn in at least one of the following aspects: for example, different fiber compositions, different amounts of the same fiber, different fiber cross-sections, different additives, different combinations of filament yarns, different combinations of filament and staple fiber yarns, different additives (such as flame retardant additives, pigments, antioxidants, processing aids, catalysts or additives for controlling fiber and fabric infrared markings), different yarn sizes, different yarn spinning methods (such as ring spinning or vortex spinning), and different colors. The additional yarn can also be formed from a single fiber type. The additional yarn can consist only of partially aromatic polyamide-based fibers (such as PA-MXD6-based fibers) in the form of continuous filaments or staple fiber spun yarns or can include a mixture of staple and filament fibers (such as twisted or core-spun). The additional yarn can be a FR yarn (i.e., a flame-resistant yarn), a heat-resistant yarn, a non-FR yarn or a non-heat-resistant yarn. The heat-resistant fibers can be in any suitable proportion of the total fibers in the fabric. For example, the fibers can be 1 wt% to 100 wt%, or 1 wt% to 60 wt%, or 30 wt% to 50 wt%, or less than or equal to 100 wt% and greater than or equal to 1 wt% and less than, equal to or greater than 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, 40 wt%, 42 wt%, 44 wt%, 46 wt%, 48 wt%, 50 wt%, 52 wt%, 54 wt%, 56 wt%, 58 wt%, 60 wt%, 62 wt%, 64 wt%, 66 wt%, 68 wt%, 70 wt%, 72 wt%, 74 wt%, 76 wt%, 78 wt%, 80 wt%, 82 wt%, 84 wt%, 86 wt%, 88 wt%, 90 wt%, 92 wt%, 94 wt%, or 96 wt% or 98 wt% of the total amount of fibers in the fabric.

[0052] Elastomer fibers may be incorporated into the yarn as appropriate or may be 100% additional yarn. These fibers impart elasticity to the fabric and improve wearer comfort and contain (but are not limited to) polyether-polyurea type fibers commonly referred to as elastic fibers or elastanes (e.g., Lycra® elastanes), two-component polyester-based fibers called elastomeric polyester fibers (e.g., Lycra® T400®) and partially cross-linked polyvinyl fibers called polyolefin elastanes (e.g., XLANCE®). Elastic yarns can be formed by core-spun yarn, where the elastic core is surrounded by a flame-resistant or heat-resistant sheath.

[0053] A variety of different yarns may be used in woven fabrics, knitted fabrics or non-woven fabrics and in fabrics where the sides of the fabric from which the fabric is constructed (i.e., the “back” facing the wearer and the “front” facing away from the wearer) have different properties. Different yarns may be used to construct one direction of the fabric (e.g., multiple different warp yarns or multiple different weft yarns in a woven fabric). Different yarns can be incorporated into the fabric in regular patterns (e.g., alternating weft or ripstop at set intervals) or in random configurations.

[0054] Main yarn and one or more additional yarns in the available woven fabric Use any available weaving technique to construct the fabric in any woven pattern comprising, but not limited to, twill fabric, plain or oxford fabric, anti-crack fabric, satin (satin or sateen) fabric, multi-arm fabric, double beam or double fabric fabric or jacquard fabric.

[0055] In some states, the fabric is substantially free of flame retardant additives added to the fabric. In other states, the fabric may comprise a topical flame retardant treatment such as a tetra(hydroxymethyl)phosphonium salt (THPx) inclusion, a branded Proban® treatment or an alternative treatment comprising a branded Pyrovatex® treatment. Fabrics comprising yarns (which comprise heat-resistant fibers of the invention in the form of continuous filament or short-fiber spun yarns or comprising mixtures of short fibers and filaments (e.g., spun or cored spinning)) may be treated with flame retardant chemicals to produce retardant fabrics that meet the needs of flame retardant protective clothing, comprising outer garments and garment reinforcements and / or other flame retardant textile applications.

[0056] Fabrics provide protection for self-extinguishing and in accordance with NFPA 2112, NFPA 70E and ISO 11612, ISO 14116, ISO 61482-1-1, ISO 61482-1-2 and ISO 13506 standards.

[0057] The fabric can be incorporated into any form of apparel or non-apparel textile application. Apparel can be single-layered or multi-layered and can be worn close to the skin or layered over other garments. Fabrics containing the fibers of this invention can be used in flame-retardant protective clothing applications, such as underwear, base layers, uniforms, outerwear, footwear, accessories (e.g., headwear, fire-fighting suits, gloves, and the like) or any part thereof (e.g., linings, reinforcing materials, and the like). The fabric can be soft or stiff. The fabric can contain elastic fibers or substantially no elastic fibers. [Methods for forming heat-resistant fibers.] [ ]

[0058] Various embodiments of the present invention provide methods for forming the heat-resistant melt-spun fibers described herein. The method may comprise melt-blending a portion of aromatic polyamide and at least a portion of aliphatic polyamide to form a blend. The method may also comprise melt-spinning the blend to form a fiber. The fiber comprises a portion of aromatic polyamide, including PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof. The fiber also comprises at least a portion of aliphatic polyamide. The aromatic polyamide constitutes at least 50 wt% of the total polyamide in the fiber.

[0059] Melt spinning may involve using a total draw ratio of 3 to 6, or 3.5 to 4.7, or 3.75 to 4.7, or 4 to 4.7, or greater than 3.75, or less than or equal to 6 and greater than or equal to 3, and less than, equal to or greater than 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.75, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, or 5.9.

[0060] In various states, the blend does not contain a catalyst, such as a catalyst that increases the molecular weight of the polyamide during melt blending. In other states, the blend contains a catalyst. A catalyst can be added to the blend; the catalyst can be used during the polymerization of at least a portion of the aliphatic polyamide and / or a portion of the aromatic polyamide so that the polymer contains the catalyst, or both. The catalyst can be a catalyst that increases the molecular weight of a portion of the aromatic polyamide and / or at least a portion of the aliphatic polyamide during melt blending. The catalyst can contain a phosphorus-based catalyst, such as phosphonic acid, phosphoric acid, phenylphosphonic acid, phenylphosphonic acid, salts formed from such acids (e.g., sodium hypophosphite, sodium phosphate, and the like), or combinations thereof. Using a catalyst can increase the toughness of the fiber. [Example] [ ]

[0061] The various states of the invention can be better understood by referring to the following examples, which are provided illustrative. The invention is not limited to the instances given herein.

[0062] Material: PA-MXD6 is S6011 grade MX-resistant acetate from MGC Advanced Polymers (Colonial Heights, VA) or Mitsubishi Gas Chemical Company (Nigata, Japan) with an RV of 2.45-2.85 in 96% sulfuric acid (as measured according to ISO 307). PA66 is from INVISTA (Canada) Company (Kingston, ON). PA6 is BASF Ultramid® B24 N 02 .

[0063] Unless otherwise indicated, the relative viscosity (RV) as an 8.4 w / w% solution in 90% formic acid was measured according to ASTM D789 quantities. Measurements of breaking strength and elongation at break were performed on continuous multifilament fibers according to ASTM D2256 (configuration A: straight sample). Fiber toughness was determined by dividing the fracture strength by the fiber linear density (as measured by ASTM D1907). Implement combustion resistance performance tests according to ASTM D6413. Knitted fabric samples were prepared from 50 wt% continuous multi-stranded PA-MXD6-based resistant fibers and 50 wt% spun yarns, which contained only commercially available LenzingTM FR (made by Lenzing AG, Lenzing, Austria) adhesive fibers. Mass loss was calculated as the difference in mass of 3′′ × 12′′ samples before and after exposure to flame. The shrinkage of continuous multifilament fibers was measured according to ASTM D4974. The wear resistance of the same number of yarns was measured using the equipment articulated in ASTM D3885, which were configured parallel to each other at uniform spacing and secured to the adhesive strips prior to installation in the test equipment, as is usually performed using fabric strips. Prior to the application of the lubricant, the pyrolytic combustion flow calorimetry (PCFC) was implemented for unstretched materials extruded from the self-fiber melt-spinning system according to ASTM D7309-22. [Mixture ratio. ] [ ]

[0064] Polymer analysis using pyrolysis combustion flow calorimetry (PCFC) (Table 1) shows that increasing the amount of PA66 blended with PA-MXD6 leads to a decrease in char formation, an increase in fire growth capacity (FGC), and an increase in total heat release (total HR) during combustion. Therefore, polymer blending selection must balance the heat resistance improvements provided by PA-MXD6 with the fiber mechanical property improvements provided by PA66. The PA66 used in Tables 1-4 has an RV of 75.

[0065] Table 1. Characterization of PCFC fibers (ASTM D7309-22). Example 1 Example 2 Example 3 Comparison Example 1 Comparison Example 2 PA-MXD6 (%) 80 70 60 100 0 PA66 (%) 20 30 40 0 100 Coal yield (wt%) 9.5 7.8 5.2 16.7 1.6 FGC (J / g·K) 454 472 478 332 591 Total HR (kJ / g) 25.5 25.9 27.5 23.4 29.9

[0066] The flammability properties of fibers made from different melt blending ratios of PA-MXD6 and PA66 combined with Lenzing™ FR viscose at a 50:50 ratio are shown in Table 2. In the PA-MXD6 melt blend, a content of less than approximately 40% PA66 does not significantly affect the FR performance.

[0067] Table 2. Flammability of knitted socks (ASTM D6413). Example 1 Example 2 Example 3 Example 4 Comparison Example 1 Comparison Example 2 PA-MXD6 (%) 90 80 70 60 100 0 PA66 (%) 10 20 30 40 0 100 After the flame - average 0.6 1.0 0.6 12.6 0 19.6 After flame - standard deviation 0.5 0.8 0.5 15.7 0 12.4 Mass loss - average value (%) 10.3 11.0 11.9 24.6 9.9 22.2 Quality loss - standard deviation (%) 1.2 1.6 0.1 21.0 1.8 20.5

[0068] The physical properties of fibers spun from PA-MXD6 and PA66 with different melt blending ratios (Table 3) show that the toughness increases after PA66 is incorporated into the melt blend with PA-MXD6.

[0069] Table 3. Physical properties of melt-spun fibers at a total draw ratio of 3.9. Example 1 Example 2 Comparison Example 1 Comparison Example 2 PA-MXD6 (%) 80 60 100 0 PA66 (%) 20 40 0 100 Toughness (g / den) 6.1 6.3 5.4 6.6 Elongation at break (%) 32 33 20 26

[0070] Using fibers spun from PA-MXD6 and PA66 with different melt blending ratios (Table 4), it is shown that as the PA66 content increases, a lower feed roll temperature is required to initiate stretching.

[0071] Table 4. Minimum feed roller temperature required to initiate stretching. Example 1 Example 2 Example 3 Example 4 Comparison Example 1 PA-MXD6 (%) 90 80 70 60 100 PA66 (%) 10 20 30 40 0 Feed roller temperature (°C) 81 69 66 48 80 [N66 RV] [ ]

[0072] A 70:30 blend of PA-MXD6 and PA66 provides a balance of heat resistance, allowing up to 50% of this PA-MXD6-based fiber to be incorporated with other FR fibers, resulting in self-extinguishing fabrics suitable for protective clothing applications. Increasing the molecular weight of PA66 used in the melt blend to a level higher than that typically found in spun clothing fibers produces fibers with increased toughness and abrasion resistance that can still be processed using conventional melt spinning techniques.

[0073] The melt-blended PA-MXD6 with PA66 >= 65 RV (which may or may not contain a catalyst to further increase the molecular weight of the blend during processing) (Tables 5 and 6) demonstrates that it can be spun at higher draw ratios, resulting in fibers with improved tensile strength and durability. In use, a catalyst is used during the formation of PA-MXD6 and / or PA66, thus the catalyst is present in the melt blend of PA-MXD6 and PA66. The catalyst may be a phosphorus-based catalyst.

[0074] Table 5A. Physical properties of 70 / 30 PA-MXD6 / PA66 fibers with different RV values. Example 1a Example 1b Example 1c Example 2a Example 2b Example 2c PA-MXD6 (%) 70 70 70 70 70 70 PA66 (%) 30 30 30 30 30 30 PA66 RV 65 65 65 80 80 80 catalyst none none none none none none Total stretch ratio 4.0 4.5 4.7 4.0 4.5 4.7 Toughness (g / den) 5.8 6.9 fracture 6.6 7.0 7.8 Elongation (%) 20 17 - twenty one 15 12 Shrinkage rate (%) 12.2 13.7 - 12.7 15.1 15.4

[0075] Table 5B. Physical properties of 70 / 30 PA-MXD6 / PA66 fibers with different RV values. Example 3a Example 3b Example 3c Example 4a Example 4b Example 4c PA-MXD6 (%) 70 70 70 70 70 70 PA66 (%) 30 30 30 30 30 30 PA66 RV 95 95 95 80 80 80 catalyst none none none have have have Total stretch ratio 4.0 4.5 4.7 4.0 4.5 4.7 Toughness (g / den) 6.7 6.7 8.1 7.0 8.1 8.5 Elongation (%) 18 13 13 12 14 13 Shrinkage rate (%) 13.1 14.4 14.8 12.1 13.5 15.8

[0076] Table 5c. Physical properties of 70 / 30 PA-MXD6 / PA66 fibers with different RV values. Comparison Example 1a Comparison Example 1b Comparison Example 1c PA-MXD6 (%) 70 70 70 PA66 (%) 30 30 30 PA66 RV 50 50 50 catalyst none none none Total stretch ratio 4.0 4.5 4.7 Toughness (g / den) 5.9 6.8 fracture Elongation (%) 26 20 - Shrinkage rate (%) 11.7 13.0 -

[0077] Table 6. Flexural abrasion test of filament yarns with different polymer compositions. Example 1 Example 2 Comparison Example 1 PA-MXD6 (%) 70 70 100 PA66 (%) 30 30 0 PA66 RV 50 80 N / A catalyst none have none Failure cycle count 1489 2065 1233 [N66] [right] [N6] [ ]

[0078] Table 7 shows blends of PA-MXD6 and PA6 with the same melt viscosity that produce fibers with extremely high shrinkage and lower toughness than those using PA66.

[0079] Table 7. Physical properties of N66 and N6 as 30% PA-MXD6 based fibers. Example 1a Example 1b Example 1c Comparison Example 1a Comparison Example 1b Comparison Example 1c PA-MXD6 (%) 70 70 70 70 70 70 PA66 (%) 30 30 30 0 0 0 PA66 RV 80 80 80 N / A N / A N / A PA6 (%) 0 0 0 30 30 30 Melt pressure (psi) 2410-2450 2490-2520 catalyst none none none none none none Total stretch ratio 4.0 4.5 4.7 4.0 4.5 4.7 Toughness (g / den) 6.6 7.0 7.8 5.4 6.5 7.2 Elongation (%) twenty one 15 12 twenty three 19 16 Shrinkage rate (%) 12.7 15.1 15.4 14.6 18.5 19.2

[0080] Furthermore, the terminology and expressions used are explanatory rather than restrictive, and their use is not intended to exclude any equivalent forms of the features or portions thereof shown and described. It should be understood that various modifications are possible within the scope of this invention. Therefore, it should be understood that although this invention has been specifically disclosed by way of particular features and optional characteristics, those skilled in the art can modify and vary the concepts disclosed herein, and such modifications and variations are considered to be within the scope of this invention. [Instance-specific pattern.] [ ]

[0081] The following instance samples are provided, and their numbers should not be considered as indicating a degree of importance:

[0082] Sample 1 provides a heat-resistant melt-spun fiber, comprising: Including certain aromatic polyamides such as PA-MXD6, PA-PXD6, PA-MXD6 / PXD6, or combinations thereof; and At least some aliphatic polyamines; The aromatic polyamides in this component account for at least 50 wt% of the total polyamides in the fiber.

[0083] Sample 2 provides a fiber as in Sample 1, wherein the fiber is a heat-resistant fiber spun from a melt-blended composition comprising the aromatic polyamide and at least the aliphatic polyamide.

[0084] Sample 3 provides fibers as described in any one of Samples 1 to 2, wherein the aromatic polyamide portion includes PA-MXD6.

[0085] Sample 4 provides fibers as in any of Samples 1 to 3, wherein the aromatic polyamide portion has an RV of 1.5 to 4 in 96% sulfuric acid, as measured according to ISO 307.

[0086] Sample 5 provides fibers as in any of Samples 1 to 4, wherein the aromatic polyamide portion has an RV of 2.4 to 2.9 in 96% sulfuric acid, as measured according to ISO 307.

[0087] Sample 6 provides a fiber as described in any one of Samples 1 to 5, wherein the aromatic polyamide portion comprises 51 wt% to 99.5 wt% of the fiber.

[0088] Sample 7 provides a fiber as described in any one of Samples 1 to 6, wherein the aromatic polyamide portion comprises 55 wt% to 90 wt% of the fiber.

[0089] Sample 8 provides a fiber as described in any one of Samples 1 to 7, wherein the aromatic polyamide portion comprises 60 wt% to 80 wt% of the fiber.

[0090] Sample 9 provides a fiber as described in any one of Samples 1 to 8, wherein the fiber has a weight ratio of the aromatic polyamide to the at least aliphatic polyamide of greater than 50:50 to 95.5:0.5.

[0091] Sample 10 provides a fiber as described in any one of Samples 1 to 9, wherein the fiber has a weight ratio of the aromatic polyamide to the at least aliphatic polyamide of 51:49 to 95.5:0.5.

[0092] Sample 11 provides a fiber as described in any one of Samples 1 to 10, wherein the fiber has a weight ratio of the aromatic polyamine to the at least aliphatic polyamine of 55:45 to 90:10.

[0093] Sample 12 provides a fiber as described in any one of Samples 1 to 11, wherein the fiber has a weight ratio of the aromatic polyamide to the at least aliphatic polyamide of 60:40 to 80:20.

[0094] Sample 13 provides a fiber as described in any one of Samples 1 to 12, wherein the aromatic polyamide portion and the at least aliphatic polyamide portion together comprise 80 wt% to 100 wt% of the fiber.

[0095] Sample 14 provides a fiber as described in any one of Samples 1 to 13, wherein the aromatic polyamide portion and the at least aliphatic polyamide portion together comprise 100 wt% of the fiber.

[0096] Sample 15 provides fibers as described in any one of Samples 1 to 14, wherein the at least portion of the aliphatic polyamine includes aliphatic polyamines, aliphatic / aromatic polyamine copolymers, or combinations thereof.

[0097] Sample 16 provides fibers as described in any one of Samples 1 to 15, wherein the at least portion of the aliphatic polyamide includes PA66, PA6, PA10, PA11, PA12, PA46, PA56, PA610, PA1010, PA1012, PA6 / 66, PA66 / D6, PA66 / 6T, PA66 / 6I, PA66 / DI, PA66 / 6T / 6I, or combinations thereof.

[0098] Sample 17 provides fibers as described in any one of Samples 1 to 16, wherein at least a portion of the aliphatic polyamide includes PA66.

[0099] Sample 18 provides fibers as described in any of Samples 1 to 17, wherein the at least portion of the aliphatic polyamide, as an 8.4 w / w% solution in 90% formic acid, has an RV of 40 to 150, as measured according to ASTM D789.

[0100] Sample 19 provides fibers as described in any of Samples 1 to 18, wherein at least a portion of the aliphatic polyamide has an RV of 65 to 95 as measured according to ASTM D789 in an 8.4 w / w% solution in 90% formic acid.

[0101] Sample 20 provides a fiber as described in any one of Samples 1 to 19, wherein the at least portion of the aliphatic polyamide comprises less than 50 wt% of the fiber.

[0102] Sample 21 provides a fiber as described in any one of Samples 1 to 20, wherein the at least portion of the aliphatic polyamide accounts for 0.5 wt% to 49.9 wt% of the fiber.

[0103] Sample 22 provides a fiber as described in any one of samples 1 to 21, wherein the at least portion of the aliphatic polyamide comprises 10 wt% to 45 wt% of the fiber.

[0104] Sample 23 provides a fiber as described in any one of Samples 1 to 22, wherein the at least portion of the aliphatic polyamide accounts for 20 wt% to 40 wt% of the fiber.

[0105] Sample 24 provides fibers as described in any one of Samples 1 to 23, wherein the fibers further include flame retardant additives.

[0106] Sample 25 provides fibers as in Sample 24, wherein the flame retardant additive includes non-halogenated flame retardants, polymeric halogenated flame retardants, or combinations thereof.

[0107] Sample 26 provides fibers as described in any one of Samples 24 to 25, wherein the flame retardant additive comprises 0.01 wt% to 25 wt% of the fiber.

[0108] Sample 27 provides fibers as described in any one of Samples 24 to 26, wherein the flame retardant additive comprises 0.1 wt% to 5 wt% of the fiber.

[0109] Sample 28 provides fibers as described in any of Samples 1 to 24, wherein the fibers are substantially free of flame retardant additives.

[0110] Sample 29 provides a fiber as described in any one of Samples 1 to 28, wherein the flame retardant additive accounts for 0 wt% to 0.01 wt% of the fiber.

[0111] Sample 30 provides a fiber as described in any of Samples 1 to 29, wherein, compared to the same fiber in which the combination of the partial aromatic polyamide and the at least partial aliphatic polyamide is replaced by the at least partial aliphatic polyamide, the fiber has increased carbon formation, as measured according to ASTM D7309-22.

[0112] Sample 31 provides a fiber as described in any one of Samples 1 to 30, wherein the fiber has a reduced total heat release, as measured according to ASTM D7309-22, compared to the same fiber in which the combination of the partial aromatic polyamide and the at least partial aliphatic polyamide is replaced by the at least partial aliphatic polyamide.

[0113] Sample 32 provides a fiber as described in any of Samples 1 to 31, wherein the fiber has increased toughness, as measured according to ASTM D1907, compared to the same fiber in which the combination of the partial aromatic polyamide and the at least partial aliphatic polyamide is replaced by the partial aromatic polyamide.

[0114] Sample 33 provides a fiber as described in any of Samples 1 to 32, wherein the fiber has increased abrasion resistance, as measured according to ASTM D3885, compared to the same fiber in which the combination of the partial aromatic polyamide and the at least partial aliphatic polyamide is replaced by the partial aromatic polyamide.

[0115] Sample 34 provides a fiber as described in any of Samples 1 to 33, wherein the fiber has a shrinkage rate of 2% to 20%, as measured according to ASTM D4974 (for filaments) or ASTM D2102 (for staple fibers).

[0116] Sample 35 provides a fiber as described in any of Samples 1 to 34, wherein the fiber has a shrinkage rate of 3% to 10%, as measured according to ASTM D4974 (for filaments) or ASTM D2102 (for staple fibers).

[0117] Sample 36 provides a fiber as described in any of Samples 1 to 35, wherein the fiber has an elongation of 10% to 50%, as measured according to ASTM D2256.

[0118] Sample 37 provides a fiber as described in any of Samples 1 to 36, wherein the fiber has an elongation of 15% to 35%, as measured according to ASTM D2256.

[0119] Sample 38 provides a fiber as described in any of Samples 1 to 37, wherein the fiber has a toughness of 4 g / den to 12 g / den, as measured according to ASTM D1907.

[0120] Sample 39 provides a fiber as described in any of Samples 1 to 38, wherein the fiber has a toughness of 5 g / den to 10 g / den, as measured according to ASTM D1907.

[0121] Sample 40 provides a heat-resistant melt-spun fiber, comprising: Some aromatic polyamides, PA-MXD6, have an RV of 2.4 to 2.9 in 96% sulfuric acid, as measured according to ISO 307; and At least partially aliphatic polyamide, which is PA66 and has an RV of 65 to 95 as measured according to ASTM D789, in an 8.4 w / w% solution in 90% formic acid. The aromatic polyamine comprises 55 wt% to 90 wt% of the total polyamine in the fiber, the at least aliphatic polyamine comprises 45 wt% to 10 wt% of the total polyamine in the fiber, and the aromatic polyamine and the at least aliphatic polyamine together comprise 90 wt% to 100 wt% of the fiber.

[0122] Sample 41 provides a heat-resistant melt-spun fiber, comprising: A partially aromatic polyamide, PA-MXD6, having an RV of 2.4 to 2.9 in 96% sulfuric acid, as measured according to ISO 307, and comprising 55 wt% to 90 wt% of the fiber; and At least a portion of the fiber is made of aliphatic polyamide, PA66, comprising 45 wt% to 10 wt% of the fiber and having an RV of 65 to 95 as measured according to ASTM D789 in an 8.4 w / w% solution in 90% formic acid.

[0123] Sample 42 provides a yarn comprising fibers as described in any one of Samples 1 to 41.

[0124] Pattern 43 provides a yarn as in Pattern 42, wherein the fiber is not a short fiber, a filament fiber, or a combination thereof.

[0125] Sample 44 provides yarns as described in any of Samples 42 to 43, which further include other fibers.

[0126] Sample 45 provides yarns as in Sample 44, wherein the other fibers include polyurethane, polyethylene, UHMWPE, polypropylene, fibrous fibers, regenerated fibrous fibers, cellulose acetate, cuprammonium (cupro, cupra), antistatic fibers, polyester, nylon, bicomponent polyester, or combinations thereof.

[0127] Sample 46 provides yarns as described in any of Samples 44 to 45, wherein the other fibers are non-flame-resistant fibers and / or non-heat-resistant fibers.

[0128] Sample 47 provides yarn as in Sample 44, wherein the other fibers are flame-resistant fibers and / or heat-resistant fibers.

[0129] Sample 48 provides yarns as described in Sample 47, wherein the flame-retardant and / or heat-resistant fibers comprise fibers containing the following: FR polyester (e.g., Indorama Trevira® CS), FR nylon, FR viscose, FR rayon (e.g., Lenzing™ FR), FR lyocell, FR cellulose acetate, meta-polyarylamide (e.g., DuPont Nomex®, Teijin Teijinconex®), para-polyarylamide (e.g., DuPont Kevlar®, Teijin Twaron®), modified polyacrylonitrile (e.g., Kaneka Protex®, Aksa Armora), phenol-formaldehyde resin (e.g., Novoloid), melamine, poly(p-phenylbenzodioxazole) (PBO), polybenzimidazole (PBI), polysulfonated amide (PSA), oxidized acrylic acid, partially oxidized acrylic acid, cross-linked acrylic acid, polyoxadiazole, aromatic polyester, aromatic copolyimide (e.g., Teijin Technora®, polybenzimidazole (PBI), polyoxadiazole (POD) (e.g., Svetlogorsk Khimvolokno Arselon and Arselon-S), polybenzoxazole (PBO) (e.g., Toyobo Zylon®), polyamide-imide (e.g., Kermel®), polyamide (e.g., Evonik P84®), phenolic resins, crosslinked acrylonitrile (e.g., PyroTex®, Grupo ADI Tecstar®), oxidized or partially oxidized polyacrylonitrile (PAN) (e.g., TECGEN®), polyarylates (e.g., Kuraray Vectran™), polysulfonamide (PPS), poly{2,6-diimidazole[4,5-b:40; 50-e]-pyridyl-1,4-(2,5-dihydroxy)pyridylphenyl} (PIPD), polyetherimide (PEI), polyvinyl naphthalene dicarboxylate (PEN), vinylon, polytetrafluoroethylene (PTFE), expanded PTFE or combinations thereof.

[0130] Sample 49 provides a fabric comprising yarns as described in any of Samples 42 to 48.

[0131] Pattern 50 provides a fabric as in Pattern 49, wherein the fabric is a woven fabric, a knitted fabric, a non-woven fabric, or a combination thereof.

[0132] Sample 51 provides a fabric as described in any one of Samples 49 to 50, wherein the fabric includes a local flame-retardant treatment.

[0133] Sample 52 provides a fabric as described in any one of samples 49 to 51, wherein the fiber accounts for 1 wt% to 100 wt% of the total fiber content of the fabric.

[0134] Sample 53 provides a fabric as described in any one of Samples 49 to 52, wherein the fiber accounts for 30 wt% to 50 wt% of the total fiber content of the fabric.

[0135] Sample 54 provides a fabric as described in any of Samples 49 to 53, wherein the fabric is self-extinguishing and provides protection in accordance with NFPA 2112, NFPA 70E and ISO 11612, ISO 14116, ISO 61482-1-1, ISO 61482-1-2 and ISO 13506 standards.

[0136] Sample 55 provides a fabric as described in any one of Samples 49 to 54, wherein the yarn is the main yarn, and wherein the fabric further includes at least one additional yarn that is different in composition from the main yarn.

[0137] Pattern 56 provides a fabric as in Pattern 55, wherein the additional yarn is a flame-resistant yarn and / or a heat-resistant yarn.

[0138] Sample 57 provides a fabric as in Sample 55, wherein the additional yarn is a non-flame-resistant yarn and / or a non-heat-resistant yarn.

[0139] State 58 provides a method for forming fibers as described in any one of states 1 to 41, the method comprising: The aromatic polyamine and at least the aliphatic polyamine are melt-blended to form a blend; and The blend is melt-spun to form the fiber.

[0140] Sample 59 provides a method similar to that of Sample 58, wherein the melt spinning includes a total draw ratio of 3 to 6.

[0141] Sample 60 provides a method as described in any of Samples 58 to 59, wherein the melt spinning comprises a total draw ratio of 3.5 to 4.7.

[0142] Sample 61 provides a method as described in any of Samples 58 to 60, wherein the melt spinning includes a total draw ratio greater than 3.75.

[0143] Sample 62 provides a method as described in any one of Samples 58 to 61, wherein the blend further comprises a phosphorus-based catalyst.

[0144] Sample 63 provides a method as in Sample 62, wherein the catalyst comprises phosphonic acid, phosphoric acid, phenylphosphonic acid, phenylphosphonic acid, salts formed from such acids, or combinations thereof.

[0145] Sample 64 provides a method as described in any of Samples 62 to 63, wherein the catalyst increases the molecular weight of the portion of the aromatic polyamide and / or the at least portion of the aliphatic polyamide during the melt blending.

[0146] Sample 65 provides fibers, yarns, fabrics or methods such as any one or any combination of samples 1 to 64, which are configured such that all the elements or options cited are available or can be selected from them.

Claims

1. A heat-resistant melt-spun fiber, comprising: The fiber contains a portion of aromatic polyamides, including PA-MXD6, PA-PXD6, PA-MXD6 / PXD6 or combinations thereof; and at least a portion of aliphatic polyamides, including PA66; wherein the aromatic polyamides comprise at least 50 wt% of the total polyamides in the fiber.

2. The fiber as claimed in claim 1, wherein the aromatic polyamide portion comprises PA-MXD6.

3. The fiber as claimed in claim 1, wherein the aromatic polyamide portion has an RV of 2.4 to 2.9 in 96% sulfuric acid, as measured according to ISO 307.

4. The fiber of claim 1, wherein the fiber has a weight ratio of the aromatic polyamide to the at least aliphatic polyamide of 51:49 to 95.5:0.

5.

5. The fiber of claim 1, wherein the fiber has a weight ratio of the aromatic polyamide to the at least aliphatic polyamide of 60:40 to 80:

20.

6. The fiber of claim 1, wherein the aromatic polyamide portion and the at least aliphatic polyamide portion together comprise 80 wt% to 100 wt% of the fiber.

7. The fiber of claim 1, wherein the aromatic polyamide portion and the at least aliphatic polyamide portion together comprise 100 wt% of the fiber.

8. The fiber of claim 1, wherein the at least portion of the aliphatic polyamide further comprises PA6, PA10, PA11, PA12, PA46, PA56, PA610, PA1010, PA1012, PA6 / 66, PA66 / D6, PA66 / 6T, PA66 / 6I, PA66 / DI, PA66 / 6T / 6I or combinations thereof.

9. The fiber of claim 1, wherein at least a portion of the aliphatic polyamide has an RV of 65 to 95 as a solution in 8.4 w / w% of 90% formic acid, as measured according to ASTM D789.

10. The fiber of claim 1, wherein the at least portion of the aliphatic polyamide further comprises PA6.

11. The fiber of claim 1, wherein the fiber further comprises a flame retardant additive.

12. The fiber of claim 1, wherein the fiber is substantially free of flame retardant additives, wherein the flame retardant additives comprise 0 wt% to 0.01 wt% of the fiber.

13. A heat-resistant melt-spun fiber, comprising: The fiber contains a partially aromatic polyamide, PA-MXD6, having an RV of 2.4 to 2.9 in 96% sulfuric acid, as measured according to ISO 307; and at least a partially aliphatic polyamide, PA66, having an RV of 65 to 95 in an 8.4 w / w% solution in 90% formic acid, as measured according to ASTM D789; wherein the partially aromatic polyamide comprises 55 wt% to 90 wt% of the total polyamide in the fiber, the at least aliphatic polyamide comprises 45 wt% to 10 wt% of the total polyamide in the fiber, and the partially aromatic polyamide and the at least aliphatic polyamide together comprise 90 wt% to 100 wt% of the fiber.

14. A heat-resistant melt-spun fiber, comprising: A portion of the fiber is an aromatic polyamide, PA-MXD6, having an RV of 2.4 to 2.9 in 96% sulfuric acid, as measured according to ISO 307, and comprising 55 wt% to 90 wt% of the fiber; and at least a portion of the fiber is an aliphatic polyamide, PA66, comprising 45 wt% to 10 wt% of the fiber and having an RV of 65 to 95 in an 8.4 w / w% solution in 90% formic acid, as measured according to ASTM D789.

15. A yarn comprising fibers as claimed in any one of claims 1 to 14.

16. A fabric comprising yarns as claimed in claim 15.

17. The fabric of claim 16, wherein the fabric includes a local flame-retardant treatment.

18. A method for forming a fiber as claimed in any one of claims 1 to 14, the method comprising: The aromatic polyamide and at least the aliphatic polyamide are melt-blended to form a blend; The blend is then melt-spun to form the fiber.

19. The method of claim 18, wherein the blend further comprises a phosphorus-based catalyst.