High-energy protective laminate

Abstract

The present disclosure relates to flame retardant laminates useful in the manufacture of flame retardant fabrics and flame retardant garments. The laminates described herein allow for the use of non-flame retardant fabrics to produce flame retardant laminates. The use of the non-flame retardant fabric can provide a laminate that is lighter in weight, more comfortable and skin-friendly, more breathable, more durable, more color selections, better moisture management properties, higher mechanical strength, and more environmentally friendly than flame retardant laminates using intrinsically flame retardant fabrics.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to lightweight protective laminates comprising multiple fabric layers. In particular, the protective laminate can provide protection from deflagration and arc discharge. BACKGROUND OF THE INVENTION

[0002] To reduce injury, protective laminates and garments are required for occupational work in hazardous environments where short-term exposure to flames or arc flashes may occur. The protective equipment for workers exposed to these conditions should provide some enhanced protection, allowing the wearer to quickly and safely move away from the hazard rather than repair it.

[0003] Traditionally, garments providing protection from short-term deflagration or electrical flash have been relatively heavy and require multiple layers, each layer providing an additional level of protection against heat from the exposure. Such garments are made from multiple layers of non-flammable, non-melting fabrics, such as those made from aramid, polybenzimidazole (PBI), poly-p-phenylene-2,6-benzobisoxazole (PBO), modacrylic blend, polyamine, carbon, polyacrylonitrile (PAN), and their blends and combinations. These fibers can be inherently flame retardant and are commonly used in the fire protection community, but have several limitations. Specifically, relatively heavy and bulky fabrics are required to achieve the desired level of protection. Typically, the basis weight of these fabrics can exceed 400 grams per square meter. The fibers used to form these fabrics can be very expensive, difficult to dye or print, and may not have sufficient abrasion tolerance. Additionally, these fibers absorb more water and provide an unsatisfactory touch compared to nylon or polyester-based fabrics. There is a continuing need for lightweight, breathable, water-resistant garments with enhanced burn protection for optimal user performance in environments with possible arc flash exposure. There is a continuing need for waterproof, flame retardant (FR), arc flash resistant, protective garments that minimize or eliminate the use of typical non-flammable, non-melting fabrics, such as those used in the fire protection community. SUMMARY OF THE INVENTION

[0004] In a first embodiment, the present disclosure relates to a laminate comprising: a) a first fabric layer; b) a first layer of a thermally reactive material; c) a carrier layer; d) a second layer of a thermally reactive material; and e) a second fabric. In the embodiments described herein, the first and second layers of the thermally reactive material each independently comprise a polymer resin and expandable graphite. Further, the first layer of the thermally reactive material is located between the first fabric layer and the carrier layer, and the second layer of the thermally reactive material is located between the carrier layer and the second fabric layer.

[0005] In the second embodiment, each layer of the thermally reactive material is applied independently in a continuous or discontinuous manner.

[0006] In any of the foregoing embodiments, each layer of the thermally reactive material may be in the form of discontinuous points, lines, or a grid pattern.

[0007] In any of the foregoing embodiments, at least one of the first and second layers of the thermally reactive material includes a flame retardant additive.

[0008] In any of the foregoing embodiments, the first fabric layer includes meltable fibers or consists essentially of meltable fibers. In any of the foregoing embodiments, the first fabric layer includes non-meltable fibers or consists essentially of non-meltable fibers. In any of the foregoing embodiments, the first fabric layer includes a mixture of meltable and non-meltable fibers or consists essentially of a mixture of meltable and non-meltable fibers.

[0009] In any of the foregoing embodiments, the first fabric layer may include from 0% to 100% meltable fibers, based on the total weight of meltable and non-meltable fibers in the first fabric layer. In other embodiments, the first fabric layer may include meltable fibers in the following ranges: greater than 0% to 100% meltable fibers, or 0.5% to 100% meltable fibers, or 1% to 100%, or 1% to 99% meltable fibers, or 3% to 100% meltable fibers, or 5% to 100% meltable fibers, or 10% to 100% meltable fibers, 20% to 100% meltable fibers, 25% to 100% meltable fibers, 30% to 100% meltable fibers, 35% to 100% meltable fibers, 40% to 100% meltable fibers, 50% to 100% meltable fibers, 60% to 100% meltable fibers, 70% to 100% meltable fibers, 80% to 100% meltable fibers, 90% to 100% meltable fibers. In other embodiments, the first fabric includes a combination of meltable and non-meltable fibers in the range of 1 to 99% non-meltable fibers and 1 to 99% meltable fibers, where the weight percentages are based on the total weight of the fibers in the first fabric layer. Each percentage is based on the total weight of the fibers in the first fabric layer.

[0010] In some of the foregoing embodiments, the first fabric layer may comprise 100% nylon fabric. In some of the foregoing embodiments, the first fabric layer may be 100% polyester fabric. In still further embodiments, the first fabric layer comprises from 30% to 70% nylon and 30% to 70% cotton; or from 30% to 68% nylon and 30% to 68% cotton, and up to about 5 wt% antistatic additive, based on the total weight of the fabric; or from 30% to 70% polyester and 30% to 70% cotton; or from 30% to 68% polyester and 30% to 68% cotton, and up to about 5 wt% antistatic additive, based on the total weight of the fabric. In other embodiments, the first fabric layer is a cotton fabric comprising up to 100% cotton. In other embodiments, the first fabric layer is a wool fabric comprising up to 100% wool.

[0011] In any of the foregoing embodiments, the second fabric layer comprises fusible fibers or consists essentially of fusible fibers. In any of the foregoing embodiments, the second fabric layer comprises non-fusible fibers or consists essentially of non-fusible fibers. In any of the foregoing embodiments, the second fabric layer comprises a mixture of fusible and non-fusible fibers or consists essentially of a mixture of fusible and non-fusible fibers.

[0012] In any of the foregoing embodiments, the second fabric layer may comprise from 0% to 100% fusible fibers, based on the total weight of fusible and non-fusible fibers in the second fabric layer. In other embodiments, the second fabric layer may comprise from greater than 0% to 100% fusible fibers, or from 0.5% to 100% fusible fibers, or from 1% to 100%, or from 1% to 99% fusible fibers, or from 3% to 100% fusible fibers, or from 5% to 100% fusible fibers, or from 10% to 100% fusible fibers, or from 20% to 100% fusible fibers, or from 25% to 100% fusible fibers, or from 30% to 100% fusible fibers, or from 35% to 100% fusible fibers, or from 40% to 100% fusible fibers, or from 50% to 100% fusible fibers, or from 60% to 100% fusible fibers, or from 70% to 100% fusible fibers, or from 80% to 100% fusible fibers, or from 90% to 100% fusible fibers. In other embodiments, the second fabric comprises a combination of fusible and non-fusible fibers in the range of 1 to 99% non-fusible fibers and 1 to 99% fusible fibers, wherein the weight percentages are based on the total weight of the fibers in the second fabric layer. Each percentage is based on the total weight of the fibers in the second fabric layer.

[0013] In some of the foregoing embodiments, the second fabric layer may comprise 100% nylon fabric. In other embodiments, the second fabric layer may be 100% polyester fabric. In still further embodiments, the second fabric layer may comprise from 30% to 70% nylon and 30% to 70% cotton; or from 30% to 68% nylon and 30% to 68% cotton, and up to about 5 wt% antistatic additive, based on the total weight of the fabric; or comprise from 30% to 70% polyester and 30% to 70% cotton; or from 30% to 68% polyester and 30% to 68% cotton, and up to about 5 wt% antistatic additive, based on the total weight of the fabric; or comprise from 40% to 60% nylon and 40% to 60% cotton, and up to about 5 wt% antistatic additive, based on the total weight of the fabric; or from 30 to 68% aramid and 30 to 68% flame retardant viscose and up to about 5% antistatic additive. In other embodiments, the second fabric layer is a cotton fabric comprising up to 100% cotton. In other embodiments, the second fabric layer is a wool fabric comprising up to 100% wool.

[0014] In any of the foregoing embodiments, layer a) and c) are joined to each other using the first layer of the thermoreactive material, and layer c) and e) are joined to each other using the second layer of the thermoreactive material.

[0015] In any of the foregoing embodiments, the first layer of the thermoreactive material covers greater than or equal to 25% of the first fabric layer and / or the carrier layer.

[0016] In any of the foregoing embodiments, the second layer of the thermoreactive material covers greater than or equal to 25% of the second fabric layer and / or the carrier layer.

[0017] In any of the foregoing embodiments, the expandable graphite expands at least about 900 microns when heated to about 280 °C, as measured in a TMA expansion test.

[0018] In any of the foregoing embodiments, the carrier layer comprises a film, a fabric, or a combination thereof. In some embodiments, the carrier layer may be a film, such as a film comprising: a fluoropolymer, a polyimide, a silicone, a polyurethane, polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), or a combination thereof. In any of the foregoing embodiments, the carrier layer may be a nonwoven fabric, such as an aramid nonwoven fabric. In other embodiments, the carrier layer may be a laminate of one or more films and one or more fabrics. In some embodiments, the carrier layer may comprise a fusible film or a non-fusible film, a fabric, or a combination thereof.

[0019] In any of the foregoing embodiments, the laminate may further comprise one or more additional layers of a thermally reactive material and one or more additional layers of a fabric layer, wherein each subsequent additional layer is located adjacent to at least one of the first and / or second fabric layers.

[0020] The present disclosure also relates to a method of forming a laminate, the method comprising: i) adhering a first fabric layer to a carrier layer using a first thermally reactive material to form a precursor laminate; and ii) adhering the precursor laminate to a second fabric layer using a second thermally reactive material, wherein the first and second thermally reactive materials independently comprise a polymeric resin and expandable graphite.

[0021] In any of the foregoing embodiments, the laminate may be used in a protective article, wherein the first fabric layer is an outer portion of the protective article when compared to a second fabric layer forming an inner portion of the protective article. The protective article may include, for example: clothing such as shirts, jackets, pants, coveralls, work pants, aprons, hats, gloves, and footwear; sheets, blankets, tents.

[0022] The present disclosure also relates to the use of any of the foregoing laminates, the use for increasing the thermal protection performance of a protective article comprising the laminate against arc discharges up to 100 cal / cm 2 as compared to a protective article having first and second layers that do not use the thermally reactive material.

[0023] The present disclosure relates to clothing comprising a laminate according to any of the foregoing embodiments.

[0024] The laminate according to the present disclosure can be used as a flame retardant article, such as flame retardant clothing, a flame retardant blanket, or a flame retardant sheet. Typically, flame retardant clothing is required to be made using flame retardant fabrics. The laminates described herein allow for the production of the laminates using non-flame retardant fabrics. Using non-flame retardant fabrics can provide laminates that may have one or more of the following benefits. The laminates can be lighter in weight, more comfortable to the skin, more breathable, more durable, have a greater color selection, better moisture management properties, higher mechanical strength, and be more environmentally friendly. The disclosed laminates also help reduce the environmental footprint by using recycled components in the fabric layers, which results in a lower MSIHIGG index for the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a cross-sectional schematic view of one embodiment described herein.

[0026] Figure 2 is a cross-sectional schematic view of one embodiment described herein.

[0027] Figure 3A and 3B are schematic diagrams of the deposition of a thermally reactive material according to two different embodiments.

[0028] Figure 4 are schematic diagrams of overlapping points, partially overlapping points, and non - overlapping points of the thermally reactive material. Detailed Embodiments

[0029] The disclosures of all cited patent documents and non - patent documents are incorporated herein by reference in their entirety.

[0030] As used herein, the terms "embodiment" or "disclosure" are not meant to be limiting, but generally apply to either the embodiments defined in the claims or any of the embodiments described herein. These terms are used interchangeably herein.

[0031] Unless otherwise specified, the use of numerical values within the various ranges specified in this application are meant to be approximate values, as if the minimum and maximum values within the stated ranges were each preceded by the word "about". In this manner, minor variations above and below the specified ranges can be used to achieve substantially the same results as the values within the ranges. Further, the disclosure of these ranges is intended as a continuous range, including every value between the minimum and maximum values.

[0032] The features and advantages of the present disclosure will be more readily understood by those of ordinary skill in the art by reading the following detailed embodiments. It will be understood that certain features of the present disclosure (described in the text of different embodiments above or below for the sake of clarity) can be provided in a single element in a combined manner. Conversely, for the sake of brevity, the various features of the present disclosure described in the context of a single embodiment can also be provided separately or in any sub - combination. Further, unless the context clearly dictates otherwise, the recitation of the singular can also include the plural (e.g., "a, an" can refer to one or more).

[0033] Unless otherwise expressly stated, the use of numerical values within the various ranges specified in this application are expressed as approximations, as if the minimum and maximum values within the stated ranges were each preceded by the word "about". In this way, minor variations above and below the specified ranges can be used to obtain substantially the same results as the values within the ranges. Additionally, the disclosure of these ranges is intended as a continuous range, including every value between the minimum and maximum values.

[0034] As used herein, unless otherwise expressly stated, the terms "fiber," "filament," and "yarn" are used interchangeably. A fiber is intended to mean a fine thread having a limited length (e.g., from a few millimeters to about 30 centimeters in length). The term "filament" is intended to mean a fine thread having a substantially infinite length. A filament can be several kilometers in length. The term "yarn" means a continuous strand comprising one or more fibers and / or filaments. Any known yarn can be used, such as a single yarn, a plied yarn, a cord yarn, a stretch yarn, or any combination thereof. Fibers and / or filaments can be used to make yarns.

[0035] As used herein, the term "meltable" when used in connection with a fiber, filament, yarn, or fabric, means that the fiber melts at a temperature less than or equal to 280 °C, or less than or equal to 300 °C. In embodiments where the yarn or fabric is made of a single material, such as 100% nylon 6, the melting point of the material is the melting point of nylon 6. However, in yarn or fabric embodiments that include a mixture of both meltable and non-meltable fibers, the melting of the meltable material can be masked by the non-meltable component. For example, in the case of a fabric comprising a 50 / 50 blend of nylon 6.6 and cotton, the melting nylon 6.6 can be absorbed by the cotton component, and when subjected to the melting and heat stability tests described herein, the fabric sample can appear to be non-meltable. Thus, for the purposes of this disclosure, when a meltable fiber is present in a blend of meltable and non-meltable fibers, the material is considered to be a meltable material.

[0036] The present disclosure describes fabrics used in the layers of the laminate. As used herein, each of the first and second fabric layers can independently be a single-layer or multi-layer fabric, in a woven, knitted, or non-woven form. The fabric is produced from fibers, filaments, and / or yarns that can be fusible, non-fusible, or a combination thereof. The fibers, filaments, or yarns can be synthetic and / or natural. Depending on the type and composition of the fibers, filaments, or yarns, the corresponding fabric can have various different properties. The fabric can be fusible, non-fusible, flammable, flame-retardant, abrasion-resistant, heat-resistant, shrink-resistant, or the fabric can have a combination of those properties. As used herein, the term "shrink-resistant" means that when exposed to a high-energy event, the fabric and / or laminate shrink less than 20%, or less than 10%, or less than 5% of its width, its length, or both. As used herein, the term "high energy" or "high-energy event" means exposure to a temperature greater than or equal to 180 °C for greater than or equal to 0.1 second. In other embodiments, the laminate described herein shrinks less than 20%, or less than 10%, or less than 5% when subjected to a shrinkage test at 180 °C according to ISO 17493. In other embodiments, the laminate described herein shrinks less than 20%, or less than 10%, or less than 5% when subjected to a shrinkage test at 260 °C according to ISO 17493.

[0037] Laminates are described herein that have: a) a first fabric layer, b) a first layer of thermally reactive material, c) a carrier layer, d) a second layer of thermally reactive material, and e) a second fabric layer, wherein the first and second layers of thermally reactive material each independently comprise a polymeric resin and expandable graphite; wherein the first layer of thermally reactive material is between the first fabric layer and the carrier layer, and the second layer of thermally reactive material is between the carrier layer and the second fabric layer. The laminate can be used to manufacture protective articles, including protective clothing, wherein the first fabric layer is typically the outermost layer of the garment, and the second fabric layer is the inner layer of the garment. Protective articles can include, for example: clothing, garments, tents, blankets, and / or coverings. Protective clothing includes garments such as jackets, pants, shirts, vests, coveralls, as well as gloves, leggings, hoods, footwear, and shoes. Protective clothing containing the laminate can be waterproof or water-resistant and breathable. Protective clothing needs to be lightweight for widespread use, especially in situations where there is a risk of exposure to deflagration or high-temperature accidents, for example, exposure to arc flash but with a low probability. In some embodiments, the weight of the laminate can be, for example, less than or equal to 500 grams per square meter 2(gsm). In some embodiments, the weight of the laminate may be in the following ranges: 200 gsm to 500 gsm, or 200 gsm to 475 gsm, or 200 gsm to 450 gsm, or 200 gsm to 425 gsm, or 200 gsm to 400 gsm. In still further embodiments, the weight of the laminate may be in the following ranges: 225 gsm to 400 gsm, or 250 gsm to 375 gsm, or 275 gsm to 375 gsm, or 275 gsm to 350 gsm.

[0038] To reduce the weight of the laminate, the weight should be reduced without loss of protective properties or reduction of breathability or waterproofness. As described herein, the weight of each of the first fabric layer, the carrier layer, and the second fabric layer can be reduced without sacrificing the ability of the laminate to provide protection to the wearer from high heat events or arc flash exposure. By using relatively lightweight layers, the overall weight of the laminate can be reduced. However, when the weight of layers a), c), and / or e) is too low, during a deflagration or other high heat conditions, there is an increased risk that sufficient heat or energy from the event can affect the wearer. Accordingly, the laminate of the present invention provides additional protection by using at least two layers of heat-reactive material. The first layer of the heat-reactive material absorbs at least a portion of the heat from the event, while the second layer of the heat-reactive material can absorb additional heat that may have passed through the carrier layer and can help minimize the heat transferred to the wearer.

[0039] First fabric layer

[0040] The laminate described herein includes a first fabric layer. Suitable fibers, filaments, or yarns for the first fabric layer can include: nylon, nylon 6, nylon 6.6, nylon 12, nylon 6.12, polyester, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyurethane, elastane, acrylic, polyolefin, polyethylene, polypropylene, aramid, meta-aramid, para-aramid, Aramid, Aramid, polyamide-imide, polybenzimidazole (PBI), polybenzoxazole (PBO), FR viscose fiber, FR cotton, modified polyacrylonitrile fiber, polyamine, carbon fiber, glass fiber, polyacrylonitrile (PAN), PTFE, viscose fiber, rayon, cotton, wool, silk, cellulose, jute, flax, bamboo, hemp, or combinations thereof. Fibers and / or filaments can be combined using known methods to form yarns. Yarns can be produced from a single type of fiber or filament, or yarns can be produced from a blend of two or more different types of fibers or filaments. Similarly, the first fabric layer can be formed from a single type of fiber, filament, and / or yarn, or from a plurality of different fibers, filaments, and / or yarns in order to provide desired fabric properties. The fabric can be a woven fabric, a knitted fabric, or a non-woven fabric.

[0041] The first fabric layer forms part of a laminate that is intended to be the outer layer of the article, directly exposed to high-energy events such as exposure to heat and / or flame. In some embodiments, the first fabric layer comprises a fusible fabric layer, i.e., the fabric layer comprises fusible fibers as defined by the fusibility definition provided herein. In some embodiments, the first fabric layer comprises a non-fusible fabric layer, such as a cotton fabric. In other embodiments, the first fabric layer can comprise a combination of fusible and non-fusible fibers, filaments, and / or yarns, such as a nylon / cotton blend or a polyester / cotton blend. In some embodiments, the first fabric is a fabric that is considered a no-melt and / or no-drip fabric according to the melt and thermal stability tests defined herein. In some embodiments, the first fabric comprises a fabric of fusible fibers, filaments, or yarns and is considered a no-melt and / or no-drip fabric according to the melt and thermal stability tests defined herein.

[0042] In still further embodiments, the laminate comprises a first fabric that includes a combination of fusible and non-fusible fibers in the range of 1 to 99% non-fusible fibers and 1 to 99% fusible fibers. In other embodiments, the first fabric layer may include from 5% to 100% fusible fibers, or from 10% to 100% fusible fibers, or from 20% to 100% fusible fibers, or from 25% to 100% fusible fibers, or from 30% to 100% fusible fibers, or from 35% to 100% fusible fibers, or from 40% to 100% fusible fibers, or from 50% to 100% fusible fibers, or from 60% to 100% fusible fibers, or from 70% to 100% fusible fibers, or from 80% to 100% fusible fibers, or from 90% to 100% fusible fibers. Each percentage is based on the total weight of the fusible and non-fusible fibers in the first fabric layer. In a further embodiment, the first fabric layer may be a knitted fabric, such as a nylon knitted fabric, a polyester knitted fabric, a polyurethane knitted fabric, or a knitted fabric containing a combination of one or more of nylon, polyester, cotton, and / or polyurethane. The knitted construction can provide a relatively lightweight fabric that helps reduce the overall weight of the laminate while still maintaining the desired flame retardant and / or arc resistant properties of the laminate. In some embodiments, the laminate comprises a first fabric layer that is free or substantially free of flame retardant or fire resistant additives. In some embodiments, the first fabric layer may be made from one or more recycled fibers, filaments, or fabrics.

[0043] In some embodiments, the first fabric layer comprises a fabric produced from fibers, filaments, or yarns having a denier (weight in grams of 9,000 meters of fiber, filament, or yarn) in the range of 5 denier (D) to 400 D. In other embodiments, the weight range of the fibers, filaments, or yarns can be 5 D to 300 D, or 5 D to 250 D, or 5 D to 200 D, or 7 D to 150 D, or 7 D to 100 D. In some embodiments, the first fabric layer can be a woven or knitted fabric comprising nylon fibers, filaments, or yarns having a denier weight range of 5 D to 400 D. In some embodiments, the first fabric layer comprises a woven or knitted fabric made from nylon yarns, wherein the yarns range from 5 D to 400 D, or 5 D to 300 D, or 5 D to 250 D, or 5 D to 200 D, or 7 D to 150 D, or 7 D to 100 D. In other embodiments, the first fabric layer can be a woven or knitted fabric made from polyester fibers, filaments, or yarns, wherein the yarns range from 5 D to 400 D, or 5 D to 300 D, or 5 D to 250 D, or 5 D to 200 D, or 7 D to 150 D, or 7 D to 100 D. Optionally, any of the first fabric layers described herein can be waterproof, and / or the first fabric layer can be water-resistant by applying a durable water-repellent (DWR) coating. The DWR coating can be on the outer side of the first fabric layer, on the side opposite the first layer of the heat-reactive material. In another embodiment, the first fabric layer comprises a waterproof material.

[0044] The first fabric layer can also comprise an antistatic agent, antistatic particles, antistatic fibers, or an antistatic polymer, as a filler, coating, or part of the fibers constituting the first fabric layer. Suitable antistatic materials include, for example, carbon black, conductive fibers, metal particles, or conductive polymers.

[0045] The first fabric layer is lightweight, having a weight of less than or equal to 200 grams per square meter (gsm), such as less than 200 gsm, less than 190 gsm, less than 180 gsm, less than 170 gsm, less than 160 gsm, less than 150 gsm, less than 140 gsm, less than 130 gsm, less than 125 gsm, less than 120 gsm, less than 110 gsm, less than 100 gsm, less than 90 gsm, or less than 85 gsm. To provide the first fabric layer with sufficient strength and durability, the fabric weight should be greater than or equal to 15 gsm, or greater than or equal to 20 gsm, or greater than or equal to 25 gsm, or greater than or equal to 30 gsm, or greater than or equal to 35 gsm, or greater than or equal to 40 gsm, or greater than or equal to 45 gsm, or greater than or equal to 20 gsm, or greater than or equal to 55 gsm. It should be noted that as the amount of non-fusible fibers increases, a higher fabric weight is required to obtain a first fabric layer with sufficient durability, strength, and abrasion resistance. For example, in the case of a 50 / 50 nylon / cotton blend, the fabric weight should be in the range of 120 to about 150 gsm.

[0046] Thermally reactive material

[0047] The laminate described herein further comprises a first layer of thermally reactive material and a second layer of thermally reactive material. The first and second layers of thermally reactive material can be independently selected from each other and can be the same or different. For the purposes of this disclosure, unless otherwise expressly stated, the description of the thermally reactive material below is intended to describe the materials that can be used for the first and / or second layers of the thermally reactive material.

[0048] The laminate described herein comprises at least two layers of thermally reactive material. Each layer of thermally reactive material independently comprises a mixture of a polymeric resin and graphite (such as expandable graphite). The average expansion rate of the expandable graphite suitable for use in the laminates and methods disclosed herein is at least 9 micrometers per degree Celsius (μm / °C) between 180°C and 280°C. Depending on the desired properties of the laminate, it may be desirable to use expandable graphite with an expansion rate as follows: an expansion rate greater than 9 μm / °C between 180°C and 280°C, or an expansion rate greater than 12 μm / °C between 180°C and 280°C, or an expansion rate greater than 15 μm / °C between 180°C and 280°C. In the thermomechanical analysis (TMA) expansion test described herein, the expandable graphite suitable for use in some embodiments expands by at least 900 micrometers (μm) when heated to 280°C. In the TMA expansion test described herein, additional expandable graphite suitable for use in certain embodiments expands by at least 400 μm when heated to 240°C.

[0049] In the TMA swelling tests described herein, additional expandable graphite suitable for use in certain embodiments swelled at least 400 μm when heated to 240 °C. If tested using the in-furnace swelling test described herein, the average swelling of expandable graphite suitable for use in an article is at least 9 cc / g at 300 °C. In one example, the average swelling of Asbury 3626 expandable graphite (available from Asbury Graphite Mills, Inc) is about 19 cc / g at 300 °C, while the swelling of Asbury 3538 expandable graphite (available from Asbury Graphite Mills, Inc) is only about 4 cc / g at 300 °C, as tested according to the in-furnace swelling test described herein.

[0050] In one embodiment, the thermally reactive material is in the form of a mixture of a polymeric resin and expandable graphite. The expandable graphite particle size suitable for the present invention should be selected such that the thermally reactive material can be applied by the selected application method. For example, if the thermally reactive material is applied by gravure printing techniques, the expandable graphite particle size should be small enough to fit into the gravure cells.

[0051] In some embodiments, the thermally reactive material comprises expandable graphite having at least the swelling as described above and an endotherm of at least about 100 joules per gram (J / g), as tested according to the DSC endotherm test method described herein. In other embodiments, it may be desirable to use expandable graphite having an endotherm greater than or equal to about 150 J / g, greater than or equal to about 200 J / g, or an endotherm greater than or equal to about 250 J / g.

[0052] In some embodiments, a laminate comprising a thermally reactive material comprising expandable graphite having a swelling greater than 900 micrometers (μm) at 280 °C and an endotherm greater than 100 J / g has an average afterflame value of less than 20 seconds, an average char length of less than 20 centimeters (cm), or an afterflame value of less than 20 seconds and an average char length of less than 20 cm, as tested according to the edge ignition test described herein.

[0053] In other embodiments, the average afterflame of the laminate can be less than 10 seconds, or less than 2 seconds, and / or the average char length of the laminate can be less than 15 cm, or less than 10 cm, as tested according to the edge ignition test.

[0054] The first and second layers of the thermally reactive material each independently comprise a polymeric resin and expandable graphite. A polymeric resin having a melting temperature or a softening temperature below 280 °C is suitable for use in the thermally reactive material. In some embodiments, the polymeric resin has sufficient fluidity or deformability to allow the expandable graphite to expand significantly when exposed at 280 °C or below 280 °C. Desirably, the tensile viscosity of the polymeric resin is low enough to allow the expandable graphite to expand and high enough to maintain the structural integrity of the thermally reactive material after the mixture of the polymeric resin and the expandable graphite expands. In other embodiments, the polymeric resin used has a storage modulus at 200 °C between 10 3 and 10 8 dyne / cm 2 and a Tanδ between 0.1 and 10. In other embodiments, the storage modulus of the polymeric resin is between 10 3 and 10 6 dyne / cm 2 . In additional embodiments, a polymeric resin having a storage modulus between 10 3 and 10 4 dyne / cm 2 is used. The polymeric resin suitable for use in some embodiments is elastomeric. Other resins suitable for use in these embodiments are crosslinkable, e.g., crosslinkable polyurethanes, e.g., R7001E (from Rohm & Haas). In other embodiments, suitable polymeric resins are thermoplastic, having a melting point between 50 °C and 250 °C, such as VP KA 8702 (from Covestro AG, Leverkusen, DE). The polymeric resins suitable for use in the embodiments described herein include polymers including but not limited to polyesters, thermoplastic polyurethanes, and crosslinkable polyurethanes, and combinations thereof. Other polymeric resins may include one or more polymers selected from the group consisting of polyesters, polyamides, acrylates, vinyl polymers, polyolefins, silicones, or epoxy resins.

[0055] The thermally reactive material may include a flame retardant material. In some embodiments, the flame retardant material may optionally be incorporated into the polymer resin. In some embodiments, the polymer resin may include at least one component or additive selected from the group consisting of: chlorinated compounds, brominated compounds, antimony oxide, organophosphorus-based compounds, phosphate esters, resorcinol bis(diphenyl phosphate), zinc borate, ammonium polyphosphate, melamine cyanurate, melamine polyphosphate, molybdenum compounds, aluminum trihydroxide, and magnesium hydroxide, which can improve the flame retardancy of the composite article. In some embodiments, the flame retardant material is melamine polyphosphate, resorcinol bis(diphenyl phosphate), or a combination thereof. The amount of the flame retardant material present may range from 0% to 60% by weight, based on the total weight of the thermally reactive material. In other embodiments, the amount of the flame retardant material present may range from 10% to 55% by weight, based on the total weight of the thermally reactive material. In some embodiments, at least one of the first layer or the second layer of the thermally reactive material includes a flame retardant material.

[0056] In some embodiments, once the laminate is exposed to a flame and / or extreme heat (e.g., at a temperature greater than or equal to 280 °C), the fusible portion (if present) of the first fabric layer is absorbed into the thermally reactive material. At the same time, the thermally reactive material may expand. In other embodiments, once the laminate is exposed to a flame and / or extreme heat (e.g., at a temperature greater than or equal to 300 °C), the fusible portion (if present) of the first fabric layer is absorbed into the thermally reactive material. At the same time, the thermally reactive material may expand. These processes may also form a char comprising the first fabric layer and the thermally reactive material.

[0057] The char resulting from the exposure of the first fabric layer and the first layer of the thermally reactive material to heat and / or high temperature (e.g., greater than or equal to 280 °C, or greater than or equal to 300 °C) is a heterogeneous melt mixture of the first fabric layer and the expanded first layer of the thermally reactive material. According to the present disclosure, char is intended to mean the carbonaceous material remaining after exposing the melt of the layer and the thermally reactive material to a temperature greater than or equal to 280 °C, or greater than or equal to 300 °C. The char is a mixture of expanded graphite and one or both of the molten polymer resin and any fusible portion of the first fabric layer. At a temperature greater than or equal to 280 °C, or greater than or equal to 300 °C, one or both of the first fabric layer and the polymer resin may also oxidize or participate in the combustion process, forming additional carbonaceous material, which becomes part of the char. Forming the char may help block the layers behind the char from being exposed to heat.

[0058] Once the laminate is exposed to a flame and / or extreme heat, the first layer of the thermally reactive material can expand (or mix with the melt of the first fabric layer) within the melt of the first fabric layer. As such, the first layer of the thermally reactive material mixes with the molten first fabric layer and protects the underlying layers and the wearer of the article. In one embodiment, the cracking time of the laminate can be increased by at least 20 seconds, or increased by at least 30 seconds, relative to a laminate composed of substantially the same materials but not having the expandable graphite material (wherein the expansion process described above does not occur), as tested according to the horizontal flame test method described herein.

[0059] In some embodiments of the thermally reactive material, the mixture forms a plurality of tendrils containing expanded graphite upon expansion. The total surface area of the thermally reactive material is significantly increased compared to before the mixture expands. In one embodiment, the surface area of the mixture increases by at least 5 times after expansion. In another embodiment, the surface area of the mixture increases by at least 10 times after expansion. Additionally, the tendrils will generally extend outward from the expanded mixture. In embodiments where the thermally reactive material is located on the substrate in a discontinuous form, the tendrils will extend to at least partially fill the open areas between the discontinuous domains. In further embodiments, the tendrils will elongate with an aspect ratio of at least 5 to 1.

[0060] During exposure to a high-energy event, such as exposure to heat, flame, and / or arc flash, due to the melting and / or expansion described above, the combination of the first fabric layer and the first layer of the thermally reactive material can dissipate at least a portion of the incident energy transmitted during the high-energy event, or absorb at least a portion of the incident energy transmitted during the high-energy event. If the energy and / or heat transmitted through the carrier layer is high enough, the expandable graphite particles of the second layer of the thermally reactive material can expand in the same manner as the expandable graphite in the first layer of the thermally reactive material, forming an additional barrier layer and absorbing an additional portion of the energy from the high-energy event, thereby providing an enhanced level of thermal protection for the wearer. In some embodiments, the second fabric layer can comprise fusible fibers, filaments, and / or yarns. If the second fabric layer also melts, the second layer of the thermally reactive material can absorb the molten second fabric layer, thereby minimizing harm to the wearer.

[0061] In one embodiment, the thermally reactive material can be produced by a method that provides a tight blend of a polymer resin and expandable graphite without causing significant expansion of the expandable graphite. Suitable mixing methods include, but are not limited to, paddle mixers, blending, and other low-shear mixing techniques. In one method, a tight blend of the polymer resin and expandable graphite particles is achieved by mixing the expandable graphite with a monomer or prepolymer prior to polymerization of the polymer resin. In another method, the expandable graphite can be blended with a dissolved polymer, where the solvent is removed after mixing. In another method, the expandable graphite is blended with a hot molten polymer at a temperature below the expansion temperature of the expandable graphite and above the melting temperature of the polymer. In methods where a tight blend of a polymer resin and expandable graphite particles or an agglomerate of expandable graphite is provided, the expandable graphite is coated or encapsulated by the polymer resin prior to expansion of the expandable graphite. In other embodiments, the tight blend is achieved prior to application of the thermally reactive material to a substrate.

[0062] The thermally reactive material comprises less than or equal to 50 weight percent (wt%) or less than or equal to 40 wt% or less than or equal to 30 wt% of the expandable graphite, based on the total weight of the thermally reactive material, with the remainder consisting essentially of the polymer resin and a flame retardant material. In other embodiments, the expandable graphite comprises less than or equal to 20 wt% or less than or equal to 10 wt% or less than or equal to 5 wt% of the thermally reactive material, with the remainder consisting essentially of the polymer resin and a flame retardant material. Generally, it is desirable that 5 wt% to 50 wt% of expandable graphite, based on the total weight of the thermally reactive material. In some embodiments, the desired flame retardant properties can be achieved with even lower amounts of expandable graphite. Loadings as low as 1 wt% can be used. Depending on the desired properties and construction of the resulting laminate, other levels of expandable graphite may also be suitable for other embodiments. Other additives, such as colorants, fillers, antimicrobial agents, processing aids, and stabilizers, can also be added to the thermally reactive material. If present, the amount of the other additives is generally less than about 10 wt%, based on the total weight of the thermally reactive material.

[0063] The first and second layers of the thermoreactive material, and more particularly the polymeric resin, can act as an adhesive, for example, for joining or bonding one layer to an adjacent layer. For example, the first layer of the thermoreactive material can adhere the first fabric layer to the carrier layer, while the second layer of the thermoreactive material can adhere the carrier layer to the second fabric layer. The first and second layers of the thermoreactive material can independently be in the form of a discontinuous adhesive, such as a series of discrete points or shapes that do not touch or overlap each other. In other embodiments, the first and / or second layer of the thermoreactive material can be a continuous layer that extends over most of the length and / or width of the laminate. In still further embodiments, the first and / or second layer of the thermoreactive material can be in the form of a series of lines or grids that extend over most of the length and / or width of the laminate. The lines or grids can be straight, curved, can be substantially parallel to each other, or can overlap each other. When the first and / or second layer of the thermoreactive material is applied in a discrete non - continuous manner, the shape of the points of the thermoreactive material can take substantially any form. In some embodiments, the shape can be circular, oval, triangular, square, rectangular, star - shaped, polygonal, quadrilateral, or any other discrete shape. The shape of the first layer of the thermoreactive material can be selected independently of the shape of the second layer of the thermoreactive material.

[0064] The amount of thermoreactive material should be applied such that each of the first fabric layer, the carrier layer, and the second fabric layer of the laminate adheres and provides the desired protection from high - energy events. Typically, each of the first and second layers of the thermoreactive material is applied such that there is provided at least 20 grams per square meter 2 (gsm) of the thermoreactive material. In some embodiments, the amount of each of the first and second layers of the thermoreactive material can independently be in the range of 20 gsm to about 130 gsm. In other embodiments, the amount of each of the first and second layers of the thermoreactive material can independently be in the ranges of 30 gsm to 120 gsm, 40 gsm to 110 gsm, 50 gsm to 110 gsm, 60 gsm to 110 gsm, 70 gsm to 110 gsm.

[0065] Carrier layer

[0066] The laminate comprises a carrier layer that is located between a first layer and a second layer of the thermally reactive material. The carrier layer can provide strength and durability to the laminate both before exposure to a high energy event and after such exposure, the high energy event causing one or more of the layers of the thermally reactive material to expand. The carrier layer can be a film or a fabric, or at least a carrier composite layer that includes a film and a fabric. As used herein, the term "film" means a continuous substrate having a length and width that are significantly greater than its thickness. The film can be solid (i.e., non-porous), microporous, or have solid regions and microporous regions. In some embodiments, the carrier layer can be a microporous film, the pores of which are filled or at least partially filled with one or more of particulate fillers and / or polymers. The microporous film can be a substrate having a nodular and fibrillar structure. It should be noted that a microporous film having a nodular and fibrillar structure is considered to be different from a fabric. In some embodiments, the carrier layer does not contain or substantially does not contain flame retardant or fire resistant additives. In other embodiments, the carrier layer can be a microporous film that is partially filled with a polymer, wherein the polymer fills at least a portion of the pores that contain a flame retardant additive.

[0067] In some embodiments, the carrier layer comprises at least one convection barrier film. The convection barrier film can comprise, for example, a thermally stable film such as a fluoropolymer, polyimide, silicone, polyurethane, polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), or a combination thereof.

[0068] In some embodiments, the carrier layer comprises a waterproof, breathable, and air-impermeable membrane; an air-impermeable membrane; a breathable membrane; or a waterproof, breathable, and air-permeable membrane. As an example of a waterproof, breathable, and air-impermeable membrane, the carrier layer may comprise a three-layer membrane, the three-layer membrane comprising two layers of ePTFE bonded to a layer of polyurethane or flame-retardant polyurethane, such as that disclosed in US 9,782,947 to Gunzel et al., which is incorporated herein by reference in its entirety. As another embodiment of a waterproof and breathable membrane, the carrier layer may comprise an expanded fluoropolymer substrate, such as an expanded polytetrafluoroethylene substrate comprising a nodular and fibrillar structure, wherein the pores are filled or at least partially filled with a polymer (such as polyurethane or flame-retardant polyurethane). In some embodiments, the carrier layer is a waterproof, breathable, and air-permeable carrier membrane that comprises an expanded fluoropolymer or expanded PTFE membrane and has two or more stratified regions, wherein each region has a different microstructure. For example, the first layer may have a relatively large average pore size and a relatively small node size compared to a second layer having a relatively small average pore size and a correspondingly relatively large average node size. In some embodiments, the carrier layer comprises a waterproof, breathable, and air-permeable carrier membrane that may have three different microstructure regions. For example, the pore sizes of the outermost two layers may be relatively large, while the pore size of the intermediate layer may be relatively small compared to the outermost microstructure layer. Suitable barrier membranes having two or more microstructure layers are disclosed, for example, in US 9,440,044 to Hodgins et al., which is incorporated herein by reference in its entirety. In some embodiments, the carrier layer comprises a breathable carrier membrane, such as a microporous fluoropolymer or microporous ePTFE membrane. In other embodiments of the breathable carrier membrane, the carrier layer comprises a microporous fluoropolymer or microporous ePTFE membrane that does not contain or substantially does not contain any polymer filling the pores. In still other embodiments, any of the above-expanded or microporous carrier layers may comprise a fluoropolymer coating on the pore walls (i.e., on the nodules and fibrils of the microporous membrane).

[0069] When the laminate is used in clothing, the carrier layer comprising the thermally stable convective barrier may help minimize convective heat transfer from the outer layer (i.e., the first fabric layer) to the layer closer to the wearer (i.e., the second fabric layer) when exposed to a high-energy event. The maximum breathability of the membrane-based convective barrier layer described herein after thermal exposure may be less than about 10 Frazier (liters / meter 2 / second (l / m 2 / s)), which is tested according to the breathability test described herein. Preferably, the breathability of the membrane-based convective barrier layer after thermal exposure is less than 5 Frazier. More preferably, the breathability of the membrane-based convective barrier layer after thermal exposure is less than 3 Frazier.

[0070] In some embodiments, asFigure 1 As shown, laminate (10) includes a first fabric layer (20), two layers (30) and (30') of thermally reactive material, a carrier layer (40), and a second fabric layer (50). In a further embodiment, as Figure 2 shown, laminate (10) may include a first fabric layer (20), a carrier layer (40) that can be a multi-layer thermally stable barrier, two layers (30) and (30') of thermally reactive material, and a second fabric layer (50). Carrier layer (40) includes two thermally stable expanded microporous membranes (42) and (42'), and a polymer layer (44) therebetween. Polymer layer (44) shows at least partial extension into the pores of expanded microporous membranes (42) and (42'). Polymer layer (44) can be waterproof, or breathable, or both. Polymer layer (44) can be polyurethane, or a layer of polyurethane containing one or more flame retardants.

[0071] The carrier layer may also include a fabric-based carrier layer, or a fabric carrier layer. Suitable fibers, filaments, or yarns for the fabric-based carrier layer can include: nylon, nylon 6, nylon 6.6, nylon 12, nylon 6.12, polyester, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyurethane, elastane, acrylic, polyolefin, polyethylene, polypropylene, aramid, meta-aramid, para-aramid, aramid, aramid, polyamide-imide, polybenzimidazole (PBI), polybenzoxazole (PBO), FR viscose fiber, FR cotton, modified polyacrylonitrile fiber, polyamine, carbon fiber, glass fiber, polyacrylonitrile (PAN), PTFE, viscose fiber, rayon, cotton, wool, silk, cellulose, jute, linen, bamboo, hemp, or combinations thereof. Fibers and / or filaments can be combined using known methods to form yarns. Yarns can be produced from a single type of fiber or filament, or yarns can be produced from a blend of two or more different types of fibers or filaments. Similarly, the fabric-based carrier layer can be formed from a single type of fiber, filament, and / or yarn, or from multiple different fibers, filaments, and / or yarns in order to provide desired fabric properties. The fabric-based carrier layer can be a woven fabric, a knitted fabric, or a non-woven fabric.

[0072] In some embodiments, the fabric-based carrier layer may comprise a combination of one or more fusible fibers and one or more non-fusible fibers. In some embodiments, the fabric-based carrier layer may be a nylon / cotton blend or a polyester / cotton blend. In some embodiments, the fabric-based carrier layer may be a woven rip-stop fabric made of fusible yarns (such as nylon or polyester) and flame-retardant yarns as rip-stop yarns, with the rip-stop yarns placed every 5 to 30 warp and / or weft yarns (such as aramid yarns). In still further embodiments, the fabric-based carrier layer may be a fabric comprising a combination of fusible fibers, filaments or yarns and wear-resistant, heat-resistant and flame-retardant (FR) fibers, filaments or yarns. In some embodiments, the fabric-based carrier layer may be a fabric comprising non-fusible fibers such as: aramid, polybenzimidazole (PBI), polybenzoxazole (PBO), FR viscose fiber, FR cotton, modified polyacrylonitrile fiber, polyamine, carbon fiber, glass fiber, polyacrylonitrile (PAN), PTFE, or combinations thereof. In some embodiments, the fabric-based carrier layer may be a non-woven fabric made of aramid. In other embodiments, the fabric-based carrier layer may be a non-woven fabric made of meta-aramid.

[0073] The weight of the carrier layer may be in the range of 3 grams per square meter 2 (gsm) to 100 gsm. In other embodiments, the weight of the carrier layer may be in the range of 4 gsm to 90 gsm, or 4 gsm to 80 gsm, or 4 gsm to 75 gsm, or 4 gsm to 70 gsm, or 4 gsm to 65 gsm, or 4 gsm to 60 gsm, or 4 gsm to 58 gsm, or 4 gsm to 56 gsm, or 4 gsm to 55 gsm, or 4 gsm to 50 gsm.

[0074] The carrier layer may further comprise an antistatic agent, antistatic particles, antistatic polymer, or antistatic fibers, either as a filler or as a coating. Suitable antistatic agents, particles, or polymers may include, for example, carbon black, conductive fibers, metal particles, or conductive polymers.

[0075] Second fabric layer

[0076] The laminate further comprises a second fabric layer adjacent the second layer of the heat reactive material on the opposite side of the carrier layer. The second fabric layer forms one of the outer layers of the laminate and is located on the opposite side of the first fabric layer. Thus, the laminate has two "outer" layers, the first fabric layer and the second fabric layer, wherein the two layers of the heat reactive material and the carrier layer form the "inner" layers of the laminate. When the laminate is formed into an article such as a garment, the first fabric layer is intended to be the outer layer of the garment, while the second fabric layer is intended to be the inner layer of the garment. However, in some embodiments, since the laminate is a three-layer laminate having an adhesive layer joining the three layers (first fabric layer, carrier layer, and second fabric layer), the second fabric layer may be used as the outer layer of the garment, while the first fabric layer may be the inner layer of the garment.

[0077] The second fabric layer may be any single or multi-layer fabric commonly used in the fabric industry. Suitable fibers, filaments, or yarns may include: nylon, nylon 6, nylon 6.6, nylon 12, nylon 6.12, polyester, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyurethane, elastane, acrylic, polyolefin, polyethylene, polypropylene, aramid, meta-aramid, para-aramid, aramid, aramid, polyamide-imide, polybenzimidazole (PBI), polybenzoxazole (PBO), FR viscose, FR cotton, modified polyacrylonitrile fiber, polyamine, carbon fiber, glass fiber, polyacrylonitrile (PAN), PTFE, viscose, rayon, cotton, wool, silk, cellulose, jute, linen, bamboo, hemp, or combinations thereof. Fibers and / or filaments may be combined using known methods to form yarns. Yarns may be produced from a single type of fiber or filament, or yarns may be produced from a blend of two or more different types of fibers or filaments. Similarly, the second fabric layer may be formed from a single type of fiber, filament, and / or yarn, or from a plurality of different fibers, filaments, and / or yarns in order to provide desired fabric properties. The fabric may be a woven fabric, a knitted fabric, or a non-woven fabric. In some embodiments, the second fabric layer does not contain or is substantially free of flame retardant or flame resistant additives.

[0078] In some embodiments, the second fabric layer may be a flame retardant fabric layer comprising one or more flame retardant natural fibers, or flame retardant synthetic fibers or filaments. In some embodiments, the second fabric layer may be a fabric comprising from 45 to 90% polyester and from 10 to 55% cotton. In other embodiments, the second fabric may be a fabric comprising from 40% to 60% polyamide-imide, from 40 to 60% viscose fiber, and from 1 to 5% antistatic agent. In other embodiments, the second fabric layer may be a fabric comprising from 50 to 70% viscose fiber and from 30 to 50% polyester. In other embodiments, the second fabric may be a fabric comprising meta-aramid or para-aramid, viscose fiber, and nylon. In other embodiments, the second fabric layer may be a fusible fabric layer. In some embodiments, the first fabric layer and the second fabric layer comprise a fusible fabric layer. In some embodiments, the second fabric is a fabric that is considered a non-melting and / or non-dripping fabric according to the melting and thermal stability tests as defined herein. In some embodiments, the second fabric comprises a fabric of fusible fibers, filaments, or yarns and is considered a non-melting and / or non-dripping fabric according to the melting and thermal stability tests as defined herein.

[0079] In still further embodiments, the laminate comprises a second fabric that comprises a combination of fusible and non-fusible fibers, in the range of from 1 to 99% non-fusible fibers and from 1 to 99% fusible fibers. In other embodiments, the second fabric layer may comprise from 5% to 100% fusible fibers, or from 10% to 100% fusible fibers, or from 20% to 100% fusible fibers, or from 25% to 100% fusible fibers, or from 30% to 100% fusible fibers, or from 35% to 100% fusible fibers, or from 40% to 100% fusible fibers, or from 50% to 100% fusible fibers, or from 60% to 100% fusible fibers, or from 70% to 100% fusible fibers, or from 80% to 100% fusible fibers, or from 90% to 100% fusible fibers. Each percentage is based on the total weight of the fibers in the second fabric layer. In further embodiments, the second fabric layer may be a knitted fabric, such as a nylon knitted fabric, a polyester knitted fabric, a polyurethane knitted fabric, or a knitted fabric containing a combination of one or more of nylon, polyester, and / or polyurethane. The knit construction may provide a relatively lightweight fabric that helps to reduce the overall weight of the laminate while still maintaining the desired flame retardant and / or arc resistant properties of the laminate. In some embodiments, the laminate comprises a second fabric layer that is free or substantially free of flame retardant or flame resistant additives. In some embodiments, the second fabric layer may be made from one or more recycled fibers, filaments, or fabrics.

[0080] The second fabric layer may also include an antistatic agent, antistatic particles, an antistatic polymer, or antistatic fibers, either as a filler or as a coating. Suitable antistatic agents, particles, or polymers may include, for example, carbon black, conductive fibers, metal particles, or conductive polymers. In some embodiments, the second fabric layer may include fusible fibers and one or more antistatic agents.

[0081] The second fabric layer may be a woven fabric, a knitted fabric, or a non-woven fabric. In some embodiments, the second fabric is a relatively lightweight fabric made from one or more synthetic fibers, such as a knitted fabric comprising a blend of cotton and polyester. In another embodiment, the second fabric layer may be an inherently flame-retardant layer comprising flame-retardant fibers or filaments. In one embodiment, the second fabric layer may be a woven fabric comprising a blend of aramid, flame-retardant viscose fibers, and an antistatic additive. The second fabric layer is lightweight, having a weight of less than or equal to 200 grams per square meter (gsm), such as less than 200 gsm, less than 190 gsm, less than 180 gsm, less than 170 gsm, less than 160 gsm, less than 150 gsm, less than 140 gsm, less than 130 gsm, less than 125 gsm, less than 120 gsm, less than 110 gsm, less than 100 gsm, less than 90 gsm, or less than 85 gsm. To provide the second fabric layer with sufficient strength and durability, the fabric weight should be greater than or equal to 15 gsm, or greater than or equal to 20 gsm, or greater than or equal to 25 gsm, or greater than or equal to 30 gsm, or greater than or equal to 35 gsm, or greater than or equal to 40 gsm, or greater than or equal to 45 gsm, or greater than or equal to 20 gsm, or greater than or equal to 55 gsm. It should be noted that as the amount of non-fusible fibers increases, a higher fabric weight is required to obtain a second fabric layer with sufficient durability, strength, and abrasion resistance. For example, in the case of a 50 / 50 nylon / cotton blend, the fabric weight should be in the range of 120 to about 150 gsm.

[0082] Additional layer

[0083] One or more additional layers may be adhered to the laminate, where the additional layer(s) adhere to the first fabric layer, the second fabric layer, or both. If one or more additional layers are adhered to the first fabric layer, the one or more additional layers are selected from the list of materials described as being useful for the first fabric layer. If one or more additional layers are adhered to the second fabric layer, the one or more additional layers may be selected from the list of materials described as being useful for the second fabric layer. The one or more additional layers may be adhered to the laminate as follows: using known laminate adhesives, using one or more additional layers of the thermally reactive materials described herein, or by any other conventional technique (e.g., sewing, quilting, gluing, hook and loop fastening, buttons, snaps, or combinations thereof).

[0084] Applying the first and second layers of HRM

[0085] The first layer of the thermally reactive material may be applied to the carrier layer, the first fabric layer, or both. The second layer of the thermally reactive material may be applied to the carrier layer (on the opposite side of the first layer of the thermally reactive material), the second fabric layer, or both. In some embodiments, the first and / or second layer of the thermally reactive material may be applied as a continuous layer. However, in embodiments where breathability and / or hand feel is desired, the first and / or second layer of the thermally reactive material may be applied in a discontinuous manner so as to form a layer of the thermally reactive material having a surface coverage of less than 100%. Providing a discontinuous application with a surface coverage of less than 100% may take various forms, including but not limited to dots, grids, lines, or combinations thereof. In some embodiments having discontinuous coverage, the average distance between adjacent regions of the discontinuous pattern is less than 5 millimeters (mm), or preferably less than 3.5 mm, 2.5 mm, 1.5 mm, or 0.5 mm. The average distance between adjacent regions may be measured by measuring the spacing between the edges of adjacent points. In embodiments where properties such as hand feel, breathability, and / or laminate weight are very important, a surface coverage of less than 90%, or equal to 80%, or less than 70%, or less than 60%, or less than 50%, or less than 40%, or less than 30% may be used. In some embodiments, the first layer of the thermally reactive material covers greater than or equal to 25% of the surface of the first fabric layer. In some embodiments, the second layer of the thermally reactive material covers greater than or equal to 25% of the surface of the second fabric layer. The coverage percentage may be calculated by measuring the geometry of the gravure cell or screen printing mask, depending on the application method used. One method of achieving a surface coverage of less than 100% involves applying the thermally reactive material by printing the thermally reactive material onto the surface of the first fabric layer, or the surface of the carrier layer (e.g., by gravure printing). Figure 3A and 3Billustrates an example where a layer (330) of a heat-reactive material is provided to a layer such as a first fabric layer (320) in a non-continuous pattern of dots ( Figure 3A ) and grids ( Figure 3B ). Each of the layers of the heat-reactive material can achieve a ratio application of the heat-reactive material with an added weight between 20 gsm and 120 gsm. In some embodiments, the layer of the heat-reactive material can achieve a ratio application with an added weight of less than 120 gsm, or less than 100 gsm, or less than 90 gsm, or less than 80 gsm. The added weight can be determined by weighing layer samples of the same size before and after applying the heat-reactive material and normalizing the size of the samples to one square meter.

[0086] In some embodiments, the process of forming a laminate comprising the first fabric layer, the carrier layer, the second fabric layer, and two layers of the heat-reactive material can be achieved in a stepwise process, while in other embodiments, the process is achieved in a continuous process. In some embodiments, the stepwise process may include the steps of: forming a precursor laminate comprising the second fabric layer, the carrier layer, and a second layer of the heat-reactive material that adheres the second fabric layer and the carrier layer together. In this stepwise process, the second layer of the heat-reactive material can be applied to the second fabric layer, the carrier layer, or both the second fabric layer and the carrier layer in a continuous or non-continuous manner. Subsequently, any known lamination technique (such as using calendering rollers) can be used to adhere the second fabric layer and the carrier layer to form the precursor laminate. The precursor laminate can be used directly as is, or can be stored for several minutes to days or months until needed. After forming the precursor laminate, the first fabric layer can be subsequently applied. In this step, the first layer of the heat-reactive material can be applied to the first fabric layer, the carrier layer side of the precursor laminate, or both in a continuous or non-continuous manner, and then the first fabric layer can be adhered to the precursor laminate (on the carrier layer side) using, for example, two or more calendering rollers.

[0087] In other embodiments, the process of forming a laminate comprising the first fabric layer, the carrier layer, the second fabric layer, and two layers of thermally reactive material can be achieved in a stepwise process, wherein the precursor laminate comprises the first fabric layer, the first layer of thermally reactive material, and the carrier layer. In these embodiments, the layer of the first thermally reactive material can be applied to the first fabric layer, the carrier layer, or both the first fabric layer and the carrier layer in a continuous or discontinuous manner. Subsequently, any known lamination technique (such as using calendering rollers) can be used to adhere the first fabric layer and the carrier layer to form a precursor laminate. The precursor laminate can be used directly as it is, or can be stored for several minutes to several days or months until needed. After forming the precursor laminate, the second fabric layer can be subsequently applied. In this step, the second layer of thermally reactive material can be applied to the second fabric layer, the carrier layer side of the precursor laminate, or both in a continuous or discontinuous manner, and then the second fabric layer can be adhered to the precursor laminate (on the carrier layer side), for example, using calendering rollers. The stepwise process as described herein can be carried out in one device, multiple devices, optionally at different locations. For example, the precursor laminate can be formed in one device and transported to a second device to form the laminate.

[0088] In other embodiments, a continuous lamination process can be used, wherein the first layer of thermally reactive material can be applied to the first fabric layer, the carrier layer, or both, the second layer of thermally reactive material can be applied to the second fabric layer, the carrier layer, or both, and in one or more lamination steps, the layers are adhered together, wherein the first fabric layer and the second fabric layer form the outermost layers of the laminate, and the carrier layer forms the inner layer between the outermost layers. In some embodiments, the first and second layers of thermally reactive material act as adhesives to adhere the laminate layers together.

[0089] In some embodiments, the method of forming the laminate comprises: i) adhering the first fabric layer to the carrier layer using the layer of the first thermally reactive material to form a precursor laminate; and ii) adhering the precursor laminate to the second fabric layer using the layer of the second thermally reactive material. In other embodiments, the method of forming the laminate comprises: i) adhering the second fabric layer to the carrier layer using the layer of the second thermally reactive material to form a precursor laminate; and ii) adhering the precursor laminate to the first fabric layer using the layer of the first thermally reactive material.

[0090] The first and second layers of the thermoreactive material are separated from each other by the carrier layer. When the first and second layers of the thermoreactive material are in a discontinuous form, such as in the form of a series of dots or an array of dots, the dots of the first layer of the thermoreactive material applied to one side of the carrier layer can be fully aligned, partially aligned, or not aligned at all with the corresponding dots of the second layer of the thermoreactive material applied to the opposite side of the carrier layer. As used herein, fully aligned means that less than or equal to 10% of the surface area of the dots of the first layer of the thermoreactive material is misaligned with the corresponding surface area of the dots of the second layer of the thermoreactive material. As used herein, when less than or equal to 10% of the surface area of the dots of the first layer of the thermoreactive material is aligned with the surface area of the corresponding dots of the second layer of the thermoreactive material, the dots of the first and second layers of the thermoreactive material are said to be misaligned. When greater than 10% to less than 90% of the surface area of the dots of the first layer of the thermoreactive material extends beyond the surface area of the corresponding dots of the second layer of the thermoreactive material, the dots of the first and second layers of the thermoreactive material are said to be partially aligned.

[0091] Figure 4 Schematic examples of aligned, partially aligned, and misaligned dots of the thermoreactive material are shown. Figure 4 A carrier layer (40) is shown, where dots (31a), (32a), and (33a) of the first layer of the thermoreactive material are on the first surface (40a) of the carrier layer (40), and dots (31b), (32b), and (33b) of the second thermoreactive material are shown on the second surface (40b) of the carrier layer (40). The thermoreactive material (31b) is an example of a misaligned dot when compared to the corresponding dot (31a) of the thermoreactive material. The thermoreactive material (32b) is an example of a partially aligned dot when compared to the corresponding dot (32a) of the thermoreactive material. The thermoreactive material (33b) is an example of an aligned dot when compared to the corresponding dot (33a) of the thermoreactive material. Without wishing to be bound by theory, it is believed that the air permeability and the moisture vapor transmission rate (MVTR) can be increased by increasing the degree of alignment between the dots or lines of the first and second thermoreactive materials.

[0092] In some embodiments, the first and second layers of the thermally reactive material are applied in a discontinuous manner, in the form of discrete shapes, wherein at least a portion of the discrete shape of the first layer of the thermally reactive material is at least partially aligned with the corresponding discrete shape of the second layer of the thermally reactive material. In other embodiments, the first and second layers of the thermally reactive material are applied in a discontinuous manner, in the form of discrete shapes, wherein at least a portion of the discrete shape of the first layer of the thermally reactive material is aligned with the corresponding discrete shape of the second layer of the thermally reactive material. In still further embodiments, the first and second layers of the thermally reactive material are applied in a discontinuous manner, in the form of discrete shapes, wherein at least a portion of the discrete shape of the first layer of the thermally reactive material is not aligned with the corresponding discrete shape of the second layer of the thermally reactive material. In still further embodiments, the first and second layers of the thermally reactive material are applied in a discontinuous manner, in the form of discrete shapes, wherein the discrete shape of the first layer of the thermally reactive material contains a mixture of aligned, partially aligned, and non-aligned shapes when compared to the corresponding discrete shape of the second layer of the thermally reactive material.

[0093] In some embodiments, the weight of the laminate is less than or equal to 500 grams per square meter 2 (gsm). In other embodiments, the weight of the laminate is less than or equal to 450 gsm, or less than or equal to 425 gsm, or less than or equal to 400 gsm, or less than or equal to 375 gsm, or less than or equal to 350 gsm, or less than or equal to 325 gsm.

[0094] The laminates described herein can provide lightweight laminates that can provide protection against electric arcs, as measured by IEC 61482-2 in an arc chamber test (IEC 61482-1-2:2014) and / or an open arc test (IEC 61482-1-1:2009, Method A). In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 500 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 475 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 450 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 425 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 400 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 375 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 350 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 325 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 300 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 275 gsm. In some embodiments, the laminates described herein comply with the standards IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 265 gsm.In some embodiments, the laminates described herein comply with Standard IEC 61482-1-1:2014 and / or IEC 61482-1-2:2014 and have a weight less than or equal to 250 gsm.

[0095] Use

[0096] The laminates described herein can be used to manufacture protective articles. The protective articles can include, for example: clothing such as shirts, jackets, pants, coveralls, work pants, aprons, hats, gloves, and footwear; sheets, blankets, tents, and the like. In each of these applications, the laminate should be oriented such that the fusible layer faces the potential threat. For example, when the laminate is used to form a jacket, the first fabric layer should be oriented to face the outer portion of the jacket, while the second fabric layer is closer to the wearer, such that in the event of exposure to high energy or high temperature, the first fabric layer is exposed to the energy before the second fabric layer.

[0097] Examples

[0098] Melting and Thermal Stability Test

[0099] This test is used to determine the thermal stability of fabric materials. This test is based on the thermal stability test described in Section 8.3 of NFPA 1975 (2004 Edition). The test oven is a hot air circulation oven as specified in ISO 17493. The test is conducted according to ASTM D 751 Standard Test Methods for Coated Fabrics, using the adhesion resistance procedure at elevated temperatures (Sections 89 to 93) with the following modifications:

[0100] Use a borosilicate glass plate measured to be 100 millimeters (mm) x 100 mm x 3 mm (4 inches (in) x 4 in x 1 / 8 in); and

[0101] Use an internal oven test temperature of 280 °C ± 5 °C. After removing the glass plate from the oven, allow the sample to cool for at least 1 hour.

[0102] Any sample side that adheres to the glass plate upon unfolding, adheres to itself, or shows signs of melting or dripping is considered fusible. Retest any sample lacking signs of melting at an internal oven test temperature of 300 °C (using a new material sample). After removing from the oven and cooling for 1 hour, any sample side that adheres to the glass plate upon unfolding, adheres to itself, or shows signs of melting or dripping is considered fusible. Any sample that does not exhibit one of these melting criteria is considered a non-fusible sample and / or a non-dripping sample (e.g., considered a non-fusible / non-dripping fabric).

[0103] TMA Swelling Test:

[0104] The expansion of exfoliated graphite particles was measured using TMA (Thermomechanical Analysis). The expansion was tested using a TA Instruments TMA 2940 instrument. A ceramic (aluminum oxide) TGA pan with a diameter of approximately 8 mm and a height of 12 mm was used to hold the sample. A macro expansion probe (with a diameter of approximately 6 mm) was used, and the bottom of the pan was set as the zero point. A sheet of exfoliated graphite with a depth of approximately 0.1 - 0.3 mm was placed in the pan, and the depth was measured using the TMA probe. The furnace was closed, and the initial sample height was measured. The furnace was heated from 25 °C to 600 °C at a heating rate of 10 °C / min. The TMA probe displacement was plotted against temperature; the displacement was used as a measure of expansion.

[0105] DSC endothermic test

[0106] The test was conducted on a Q2000 DSC from TA Instruments using a TZERO T TM sealed pan. For each sample, approximately 3 milligrams (mg) of exfoliated graphite was placed in the pan. The pan was vented by forming a vent approximately 2 mm long and less than 1 mm wide by pressing the corner of a razor blade into the center. The DSC was equilibrated at 20 °C. Subsequently, the sample was heated from 20 °C to 400 °C at 10 °C / min. The endothermic values were obtained from the DSC curve.

[0107] Weight:

[0108] The weight test of the material was conducted as described in Section 10 of ASTM D751. The unit is given in grams per square meter.

[0109] The arc chamber test was conducted using IEC 61482-1-2:2014.

[0110] The arc chamber test provides information on the performance of the material relative to the Stoll curve when subjected to an arc discharge. A result of "below" indicates that the material passed this part of the test, while a result of "above" indicates that the material did not pass the test. The chamber test also provides the following metrics: burn time (pass < 5 seconds, fail > 5 seconds); hole formation (the tested material passes this part of the test if there are no holes larger than 5 mm); and an overall pass / fail characterization.

[0111] The open arc test was conducted according to IEC 61482-1-1:2009, Method A.

[0112] This data is provided as an arc thermal performance value and is given in units of calories per square centimeter (cal / cm 2 )

[0113] In-furnace expansion test

[0114] Heat the nickel crucible in a hot furnace at 300 °C for 2 minutes. Add the test sample (about 0.5 g) of expandable graphite to the crucible and place it in a hot furnace at 300 °C for 3 minutes. After the heating period, remove the crucible from the furnace and let it cool. Then transfer the expanded graphite to a graduated cylinder to measure the expansion volume. Divide the expansion volume by the initial height of the sample to obtain the expansion rate in cc / g.

[0115] Air permeability test:

[0116] To test the air permeability of the carrier film layer after thermal exposure, clamp a 381 mm (15 inch) square sample in a metal frame and then hang it in a forced air circulation oven set at a temperature of 260 °C. After 5 minutes of exposure, remove the sample from the oven. After cooling the sample, test the air permeability of the sample according to the test method titled ISO 9237 (1995).

[0117] Vertical flame test

[0118] The test is carried out according to ASTM D6413. Expose the sample to the flame for 12 seconds. The afterflame time is averaged over 3 samples. A laminate with an afterflame greater than 2 seconds is considered flammable. The char length is also determined by this test. The sample is tested in both the warp and weft directions.

[0119] Horizontal flame test

[0120] The procedure follows ISO 15025 and the test is carried out on the front and back of the laminate respectively. This test provides information on: afterflame and duration, in seconds (if any); afterglow; hole formation; presence of burning debris; and presence of burning at the upper or vertical edges of the material.

[0121] Moisture vapor transmission rate (MVTR)

[0122] The following provides instructions for the test used to measure the moisture vapor transmission rate (MVTR). This procedure has been found to be applicable to testing membranes, coatings, and coated products.

[0123] In this process, place about 70 ml of a solution consisting of 35 parts by weight of potassium acetate and 15 parts by weight of distilled water in a 133 ml polypropylene cup with an inner diameter of 6.5 cm at its mouth. Heat-seal an expanded polytetrafluoroethylene (PTFE) membrane with a minimum MVTR of about 85,000 g / m 2 / 24 hours, tested according to the method described in U.S. Patent 4,862,730 (granted to Crosby), to the edge of the cup to create a tight, leak-proof microporous barrier containing the solution.

[0124] A similar expanded PTFE membrane was installed on the surface of the water bath. The water bath assembly was controlled at 23 °C ± 0.2 °C using a temperature-controlled chamber and a water circulation bath.

[0125] Before conducting the test procedure, the samples to be tested were allowed to condition at a temperature of 23 °C and a relative humidity of 50%. The samples were placed such that the microporous polymer membrane was in contact with the expanded polytetrafluoroethylene membrane installed on the surface of the water bath and allowed to equilibrate for at least 15 minutes before introducing the cup assembly.

[0126] The cup assembly was weighed to an accuracy of 1 / 1000 g and then placed, in an inverted manner, on the center of the test sample.

[0127] The transport of water was provided by the driving force between the water in the water bath and the saturated salt solution, and the water flux was provided by diffusion in that direction. The sample was tested for 15 minutes, the cup assembly was removed and weighed again, with a difference within 1 / 1000 g. The MVTR of the sample was calculated from the weight increase of the cup assembly and expressed as grams of water per square meter of sample surface area per 24 hours.

[0128] Edge Ignition Test

[0129] The edge ignition test was conducted in accordance with ISO 11612. This test provides information on the following: afterflame and duration, in seconds (if present); afterglow; hole formation; the presence of burning debris; and the presence of burning at the upper or vertical edges of the material.

[0130] Thermally Reactive Material 1

[0131] A flame-retardant polyurethane resin was prepared as follows: First, a resin was formed according to the examples of commonly owned U.S. Patent No. 4,532,316, and approximately 20 wt% of a phosphorus-based additive RDP, phosphate ester, was added to the reactor. After the polyurethane resin was formed, 65 parts by weight of the polyurethane resin was mixed with 24 parts by weight of expandable graphite (the expansion of the expandable graphite was greater than 900 microns at 280 °C, which was determined by the TMA expansion test) and an additional 17 parts by weight of another phosphorus-based flame retardant in a stirred container at 80 °C. The mixture was cooled and used as is.

[0132] Adhesive 1

[0133] The flame-retardant adhesive was prepared as follows: First, a resin was formed according to commonly co-owned U.S. Patent No. 4,532,316, and a phosphorus-based flame-retardant material in an amount of approximately 20 wt% was added to the reactor.

[0134] Preparation of Laminate 1

[0135] The fusible layer of 100% 85 gsm recycled polyester knitted fabric (item number RNY04Dmb, from Nan Ya Plastics Corporation, Taiwan Province, China) is laminated to the carrier layer of an ePTFE membrane (available from W.L.Gore and Associates, Newark, Delaware, part #4410078). Gravure print a heat-reactive material 1 onto the ePTFE membrane using an engraved roller with a repeating dot pattern, providing an adhesive coverage of approximately 40 - 45%, and an adhesive deposition of 40 - 45 grams per meter 2 (gsm). Place the fusible layer on top of the carrier layer and roll it between the nip of two rollers. Place the laminate on a roller for at least 24 hours of curing. Print a second layer of heat-reactive material 1 onto the exposed side of the carrier layer, i.e., opposite the fusible layer, using the same gravure as previously used. Adhere a fabric layer of 65% polyester / 35% cotton (available from Ames Europe, Enschede, the Netherlands, department number 310.300 - 000) to the second printed layer of the heat-reactive material, and roll the laminate between the nip of two rollers. Subsequently, place the laminate on a roller for at least 24 hours of curing.

[0136] Apply a fluorine-based durable water repellent to the fusible layer via a kiss coat process. The weight of laminate 1 is 298 gsm.

[0137] Prepare laminate 2

[0138] The fusible layer of 100% 85 gsm recycled polyester knitted fabric (item number RJ47Pmb, from Nan Ya Plastics Corporation, Taiwan Province, China) is laminated to the carrier layer of an ePTFE membrane (available from W.L.Gore and Associates, Newark, Delaware, part #4410078). Gravure print a heat-reactive material 1 onto the ePTFE membrane using an engraved roller with a repeating dot pattern, providing an adhesive coverage of approximately 40 - 45%, and an adhesive deposition of 40 - 45 grams per meter 2 of the adhesive. Place the fusible layer on top of the carrier layer and roll it between the nip of two rollers. Place the laminate on a roller for at least 24 hours of curing. Print a second layer of heat-reactive material 1 onto the exposed side of the carrier layer, i.e., opposite the fusible layer, using the same gravure as previously used. Adhere a knitted fabric layer of 60% viscose / 40% polyester (available from Borgini, Italy, department number 14001) to the second printed layer of the heat-reactive material, and roll the laminate between the nip of two rollers. Subsequently, place the laminate on a roller for at least 24 hours of curing.

[0139] Apply a fluorine-based durable water repellent to the fusible layer via a kiss coat process. The weight of laminate 2 is 252 gsm.

[0140] Preparing laminate 3

[0141] A fusible layer of 100% 85 gsm polyester knitted fabric (Item No. RJ47Pmb, from Nan Ya Plastics Corporation, Taiwan Province, China) is laminated to the carrier layer of an ePTFE film (available from W. L. Gore & Associates, Newark, Delaware, part #4410078). A gravure roll with a repeating dot pattern is used to gravure print a thermally reactive material 1 onto the ePTFE film, providing an adhesive coverage of about 40 - 45% and an adhesive deposition of 40 - 45 g / m 2 . The fusible layer is placed on top of the carrier layer and rolled between the nip of two rollers. The laminate is placed on a roll for at least 24 hours of curing. A second layer of thermally reactive material 1 is printed onto the exposed side of the carrier layer, i.e., opposite the fusible layer, using the same gravure as previously used. A knitted fabric layer of 60% viscose fiber / 40% polyester (available from Borgini, Italy, department no. 14001) is adhered to the second printed layer of the thermally reactive material, and the laminate is rolled between the nip of two rollers. Subsequently, the laminate is placed on a roll for at least 24 hours of curing.

[0142] A fluorine-based durable water repellent is applied to the fusible layer via a kiss coating process. The weight of laminate 3 is 251 gsm.

[0143] Preparing laminate 4

[0144] A fusible layer of 100% polyester woven fabric weighing 70 gsm (style #751125, available from Milliken, Spartanburg, South Carolina) is laminated to the carrier layer of an ePTFE film weighing 20 gsm (department #10898200, available from W. L. Gore & Associates, Newark, Delaware). A gravure roll with a repeating dot pattern is used to gravure print a thermally reactive material 1 onto the ePTFE film and provide an adhesive coverage of about 55 - 60% and an adhesive deposition of 70 - 75 gsm. Using a gravure roll with a repeating dot pattern, a second layer of thermally reactive material 1 is printed onto the exposed side of the carrier layer, i.e., opposite the fusible layer, and provides an adhesive coverage of about 40 - 45% and an adhesive deposition of 40 - 45 gsm. A fabric layer of 50% cotton / 50% polyester knitted fabric (style #6336, available from Sextet Fabrics, Inc., New York, New York) is adhered to the second printed layer of the thermally reactive material, and the laminate is rolled between the nip of two rollers. The laminate is placed on a roll for at least 24 hours of curing.

[0145] Preparing laminate 5

[0146] A fusible layer of 100% polyester woven fabric weighing 70 gsm (Style #751125, available from Milliken, Spartanburg, South Carolina) is laminated to the carrier layer of an ePTFE membrane (prepared according to the disclosure described in US 9,782,947). A gravure print of a thermally reactive material 1 is applied to the ePTFE membrane using a gravure roll with a repeating dot pattern, providing an adhesive coverage of approximately 55 - 60% and an adhesive deposit of 70 - 75 gsm. A second layer of thermally reactive material 1 is printed onto the exposed side of the carrier layer, i.e., opposite the fusible layer, using a gravure roll with a repeating dot pattern, providing an adhesive coverage of approximately 40 - 45% and an adhesive deposit of 40 - 45 gsm. A fabric layer of 50% cotton / 50% polyester knitted fabric (Style #6336, available from Sextet Fabrics, Inc., New York, New York) is adhered to the second printed layer of the thermally reactive material, and the laminate is roll-pressed between the nip of two rolls. The laminate is placed on a roll for at least 24 hours of curing. Laminate #5 weighs 306 gsm and is used as is.

[0147] Prepare Comparative Laminate A

[0148] A fusible layer of a 100% 151 gsm polyester blend 50% PET / 50% PBT woven twill fabric (Item No. SKOL004, available from Toray Textiles Europe Ltd., UK) is laminated to the carrier layer of an ePTFE membrane (available from W. L. Gore & Associates, Inc., Newark, Delaware, Division #4410078). A gravure print of a thermally reactive material 1 is applied to the ePTFE membrane using a gravure roll with a repeating dot pattern, providing an adhesive coverage of approximately 40 - 45% and an adhesive deposit of 40 - 45 grams per square meter 2 of the adhesive. The fusible layer is placed on top of the carrier layer and roll-pressed between the nip of two rolls. The laminate is placed on a roll for at least 24 hours of curing. Using the same gravure as previously used, a second layer of thermally reactive material 1 is printed onto the exposed side of the carrier, i.e., opposite the fusible layer, and a 93 gsm fabric layer of aramid / FR viscose / nylon (Item No. 12634, available from Fuchshuber Techno-Tex GmbH, Lichtenstein, Germany) is placed on the carrier layer, and the laminate is roll-pressed between the nip of two rolls. Subsequently, the laminate is placed on a roll for at least 24 hours of curing.

[0149] A fluorine-based durable water repellent is applied to the fusible layer via a kiss coating process. Comparative Laminate A weighs 302 gsm.

[0150] Prepare Comparative Laminate B

[0151] A 100% polyester woven fabric weighing 70 gsm (type #751125, available from Milliken, Spartanburg, South Carolina) is laminated as a fusible layer onto a carrier layer of an ePTFE membrane weighing 20 gsm (department #10898200, available from W. L. Gore & Associates, Inc., Newark, Delaware). A gravure roll with a repeating dot pattern is used to gravure print a thermally reactive material 1 onto the ePTFE membrane, providing an adhesive coverage of approximately 55 - 60% and an adhesive deposit of 70 - 75 gsm. The fusible layer is placed on top of the carrier layer and rolled between the nip of two rollers. The laminate is placed on a roller and cured for 48 hours. Using a gravure with a repeating dot pattern, a layer of adhesive 1 is printed onto the exposed side of the carrier layer, i.e., opposite the fusible layer, providing an adhesive coverage of 40 - 45% and an adhesive deposit of 7 - 10 gsm. A 63 gsm knitted fabric containing 40% modified polyacrylonitrile fibers, 30% CONEX, and 30% lyocell fibers (available in style #SD 2376.00 from SSM Industries, Spring City, Tennessee) is adhered to the second printed layer of the thermally reactive material, and the laminate is rolled between the nip of two rollers. Subsequently, the comparative laminate B is placed on a roller and cured for at least 24 hours. The weight of the comparative laminate B is 234 gsm.

[0152] Prepare comparative laminate C

[0153] A 100% polyester woven fabric weighing 70 gsm (type #751125, available from Milliken, Spartanburg, South Carolina) is laminated as a fusible layer onto a carrier layer of an ePTFE membrane weighing 20 gsm (department #10898200, available from W. L. Gore & Associates, Inc., Newark, Delaware). A gravure roll with a repeating dot pattern is used to gravure print a thermally reactive material 1 onto the ePTFE membrane, providing an adhesive coverage of approximately 55 - 60% and an adhesive deposit of 70 - 75 gsm. The fusible layer is placed on top of the carrier layer and rolled between the nip of two rollers. The laminate is placed on a roller and cured for 48 hours. Using a gravure with a repeating dot pattern, a layer of adhesive 1 is printed onto the exposed side of the carrier layer (i.e., opposite the fusible layer), providing an adhesive coverage of 40 - 45% and an adhesive deposit of 7 - 10 gsm. A fabric layer of a 50% cotton / 50% polyester knitted fabric (style #6336, available from Sextet Fabrics, Inc., New York, New York) is adhered to the second printed layer of the thermally reactive material, and the laminate is rolled between the nip of two rollers. The laminate is placed on a roller to cure for at least 24 hours. The weight of the comparative laminate C is 242 gsm.

[0154] Preparation of Comparative Laminate D

[0155] A fusible layer of a 100% polyester woven fabric weighing 70 gsm (type #751125, available from Milliken, Spartanburg, South Carolina) is laminated to a carrier layer of an ePTFE film weighing 20 gsm (department #10898200, available from W. L. Gore & Associates, Inc., Newark, Delaware). A gravure roll with a pattern of repeating dots is used to gravure print a thermally reactive material 1 onto the ePTFE film, providing an adhesive coverage of about 55 - 60% and an adhesive deposit of 70 - 75 gsm. The fusible layer is placed on top of the carrier layer and rolled between the nip of two rollers. The laminate is placed on a roll and cured for 48 hours. An adhesive 1 layer is printed using gravure on the exposed side of the carrier layer (i.e., opposite the fusible layer), resulting in an area coverage of about 40 - 45% and an adhesive deposit of 40 - 45 gsm. A fabric layer of a 50% cotton / 50% polyester knitted fabric (style #6336, available from Sextet Fabrics, Inc., New York, New York) is adhered to the second printed layer of the thermally reactive material, and the laminate is rolled between the nip of two rollers. The laminate is placed on a roll for at least 24 hours of curing. The weight of Comparative Laminate D is 269 gsm.

[0156] Data Table 1

[0157]

[0158]

[0159] The results in Table 1 show that, compared to comparative examples that typically provide only one of arc protection or afterflame measurement (afterflame and / or char length), these embodiments of the present invention can provide a combination of high arc flash protection values, low afterflame, and low char length while still providing a relatively low laminate weight.

Claims

1. A laminate, comprising: a) a first fabric layer; b) a first layer of thermally reactive material; c) a carrier layer; d) a second layer of thermally reactive material; and e) a second fabric layer; wherein the first and second layers of thermally reactive material each independently comprise a polymer resin and expandable graphite; Among them, the first layer of thermally reactive material is between the first fabric layer and the carrier layer, and the second layer of thermally reactive material is between the carrier layer and the second fabric layer.

2. The laminate according to claim 1, wherein each of the layers of thermally reactive material is independently applied in a continuous or discontinuous manner.

3. The laminate according to claim 1 or 2, wherein, Each of the layers of thermally reactive material is in the form of a pattern of discontinuous dots, lines or grids.

4. The laminate according to any one of claims 1 to 3, wherein, At least one of the first and second layers of thermally reactive material comprises a flame retardant material.

5. The laminate according to any one of claims 1 to 4, wherein, The first fabric layer and the second fabric layer each comprise at least one fusible fiber.

6. The laminate according to any one of claims 1 to 5, wherein the first fabric layer comprises a combination of fusible fibers and non-fusible fibers, wherein the weight percentage of the non-fusible fibers is in the range of 1% to 99%, and the weight percentage of the fusible fibers is in the range of 1% to 99%, wherein the weight percentages are based on the total weight of the fibers in each fabric layer.

7. The laminate according to any one of claims 1 to 6, wherein, Layer a) and layer c) are bonded to each other using the first layer of thermally reactive material, and layer c) and layer e) are bonded to each other using the second layer of thermally reactive material.

8. The laminate according to any one of claims 1 to 7, wherein the first layer of thermally reactive material covers greater than or equal to 25% of the surface of the first fabric layer.

9. The laminate according to any one of claims 1 to 8, wherein the second layer of thermally reactive material covers greater than or equal to 25% of the surface of the second fabric layer.

10. The laminate according to any one of claims 1 to 9, wherein, The expandable graphite expands by at least about 900 microns when heated to about 280 °C, as measured in a TMA expansion test.

11. The laminate according to any one of claims 1 to 10, wherein, The carrier layer comprises: a fluoropolymer, polyimide, silicone, polyurethane, polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), or a combination thereof.

12. The laminate according to any one of claims 1 to 11, wherein the laminate further comprises one or more additional layers of a thermally reactive material and a fabric layer, wherein, Each subsequent additional layer is disposed adjacent to the fabric layer.

13. The laminate according to any one of claims 1 to 12, wherein, The second fabric comprises fusible fibers and is considered a non-fusible / drip-free fabric according to melting and thermal stability tests.

14. A method of forming a laminate according to any one of claims 1 to 13, the method comprising: i) adhering the first fabric layer to the carrier layer using the first thermally reactive material to form a precursor laminate; and ii) adhering the precursor laminate to the second fabric layer using the second thermally reactive material.

15. Use of the laminate according to any one of claims 1 to 13 for improving the thermal protection performance of an article comprising the laminate against arc discharges up to 100 cal / cm 2 of heat.

16. An article, the article comprising a laminate according to any one of claims 1 to 13.

17. The article according to claim 16, wherein, The article is clothing.

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