JP2020158905A - Fire-retardant structure and protective product using the same - Google Patents

Abstract

To provide a fiber structure for protective clothing, which is excellent in fire retardancy and a heat insulation property and has flexibility and quick foaming in heat exposure and a protective product which is constituted by using the same.SOLUTION: A fire-retardant structure for protective clothing comprises: a fire-retardant fiber layer of which the limit oxygen index (LOI) to be regulated in JIS L 1091 E-2 Law is 26 or more: and a foam resin layer which contains urethane resin containing polyol and polyisocyanate with number average molecular weight of 3500 to 5500 as binder, and contains ammonium polyphosphate particles, melamine, and pentaerythritol.SELECTED DRAWING: None

Description

The present invention relates to a fiber structure for protective clothing having excellent flame retardancy and heat shielding properties, flexibility and rapid foaming when exposed to heat, and a protective product using the same.

Conventionally, heat protective clothing for human body protection has been proposed in environments where fire and heat exposure are expected such as fire fighting, steelmaking, and energy related. However, in such a clothing material, the heat shield property depends on the basis weight and thickness of the fabric regardless of the material of the fabric, so that there is a problem that it is heavy and difficult to move.

In order to solve such a problem, for example, in Japanese Patent Application Laid-Open No. 2-269881, a foamed resin layer containing melamine as a foaming agent, pentaerythritol as a carbon feeder, and phosphorus pentoxide as a flame retardant is provided on the surface of a flame-retardant fabric. It has been proposed that the foamed resin layer foams (swells) during heat exposure to form carbides, thereby filling the holes or gaps between the fibers of the fabric to shield the heat. However, since phosphorus pentoxide has high hygroscopicity and exhibits strong alkalinity, it lacks stability in the resin, and therefore there is room for improvement as a protective clothing.

Further, for example, Japanese Patent Application Laid-Open No. 5-65436 and Japanese Patent Application Laid-Open No. 5-863310 propose fire-resistant foam paints for construction containing melamine, pentaerythritol, ammonium polyphosphate and the like. However, the resins used in these foam paints have low flexibility and are not suitable for protective clothing because they are difficult to move. In addition, fire-resistant foam paints for construction have priority on heat resistance and durability due to their role, but for protective clothing, rapid foaming (swelling) during heat exposure and prevention of drip during high heat exposure are required. And further improvement was required.

Japanese Unexamined Patent Publication No. 2-269881 Japanese Unexamined Patent Publication No. 5-655436 Japanese Unexamined Patent Publication No. 5-86310

In view of the above problems, the present invention provides a fiber structure for protective clothing having excellent flame retardancy and heat shielding properties, flexibility and rapid foaming at the time of heat exposure, and a protective product using the same. With the goal.

As a result of diligent studies to achieve the above-mentioned problems, the present inventor causes drip even in heat exposure (flame exposure) exceeding 1000 ° C. due to a combination of a specific soft urethane and ammonium polyphosphate, pentaerythritol, and melamine. It has been found that excellent heat-shielding properties are exhibited by forming a foamed carbonized layer without forming a foamed carbonized layer, and further diligent studies have led to the completion of the present invention.

The present invention comprises a flame-retardant fiber layer having a critical oxygen index (LOI) of 26 or more specified in the JIS L 1091 E-2 method, and a urethane resin containing a polyol having a number average molecular weight of 3500 to 5500 and polyisocyanate. Provided is a flame-retardant structure for protective clothing, which comprises as a binder and has a foamed resin layer containing ammonium polyphosphate particles, melamine, and pentaerythritol. The foamed resin layer preferably contains 10 to 30 wt% of ammonium polyphosphate particles, 5 to 15 wt% of melamine, and 10 to 20 wt% of pentaerythritol. Further, it is preferable that the polyol is a polyether polyol and the polyisocyanate is a diisocyanate, and the diol component of the polyether polyol is an aliphatic having 4 to 10 carbon atoms and a freezing point of 0 to 70 ° C. Is also preferable. It is also preferable that the average particle size of the primary particle shape of the ammonium polyphosphate particles is 10 μm or less. It is also preferable that the average particle size of the dispersed particle size of the ammonium polyphosphate particles is 10 μm or less. It is also preferable that the foamed resin layer is formed discontinuously. Further, in the heat transfer evaluation defined by ISO9151 based on ISO11612, it is preferable that the time HTI ₂₄ is 7 seconds or more because the sensor temperature rises by 24 ° C.

Further, any one selected from the group consisting of arc protective clothing, flameproof protective clothing, work clothing, activity clothing, hats, gloves, protective aprons, and protective members using the flame-retardant structure. Protective products are provided.

According to the present invention, it is possible to provide a fiber structure for protective clothing having excellent flame retardancy and heat shielding property, flexibility and rapid foaming at the time of heat exposure, and a protective product using the same.

Hereinafter, embodiments of the present invention will be described in detail.

The flame-retardant structure of the present invention comprises a flame-retardant fiber layer containing flame-retardant fibers and a foamed resin layer applied to the flame-retardant fiber layer. In addition, the foamed resin layer is fixed to the flame-retardant fiber layer by a known method such as a direct application method such as knife coating, screen printing, or gravure coating, or a method of applying it to a paper pattern and laminating it with an adhesive after film formation. It suffices if it is done. The foamed resin layer is fixed to the outside (heat source side).
The flame-retardant fiber layer may be a cloth (woven fabric, knitted fabric) or a non-woven fabric, but from the viewpoint of durability, the cloth (woven fabric, knitted fabric) is preferably used for protective clothing.

The flame-retardant fiber layer of the present invention contains flame-retardant fibers having a critical oxygen index (LOI) of 26 or more as measured by JIS K7201. Examples of the flame-retardant fiber include meta-aramid fiber, para-aramid fiber, polyparaphenylene benzoxazole fiber, polybenzoimidazole fiber, polyimide fiber, polyetherimide fiber, polyamideimide fiber, carbon fiber, polyphenylene sulfide fiber, and poly. Examples thereof include vinyl chloride fiber, flame-retardant rayon, moda acrylic fiber, flame-retardant acrylic fiber, flame-retardant polyester fiber, flame-retardant vinylon fiber, melamine fiber, fluorine fiber, flame-retardant wool, and flame-retardant cotton. One or more of these flame-retardant fibers can be used. It is preferable to use these fibers as filaments, mixed fiber yarns, spun yarns and the like.

Furthermore, it is preferable to use para-aramid fibers, that is, polyparaphenylene terephthalamide or copolyparaphenylene, 3,4'-oxydiphenylene terephthalamide, and / or meta-aramid fibers, that is, polymetaphenylene isophthalamide. , Para-based aramid fiber and meta-based aramid fiber are preferably mixed and used as a spun yarn.

These flame retardant fibers are additives such as antioxidants, infrared absorbers, ultraviolet absorbers, heat stabilizers, flame retardants, titanium oxide, colorants, and inert fine particles, as long as the object of the present invention is not impaired. May be contained.

Further, the flame-retardant fiber may contain other fibers as long as the flame-retardant property is not impaired. At that time, as other fibers, one or more other fibers such as polyester fiber, nylon fiber, rayon fiber, polynosic fiber, lyocell fiber, acrylic fiber, vinylon fiber, cotton, linen, and wool should be used. Can be done.

These other fibers include antioxidants, infrared absorbers, ultraviolet absorbers, heat stabilizers, flame retardants, titanium oxide, colorants, inert fine particles, conductive particles, etc., as long as the object of the present invention is not impaired. Additives may be included.

The infrared absorber is not particularly limited as long as it has an infrared absorbing effect. For example, antimony-doped tin oxide, indium tin oxide, niob-doped tin oxide, phosphorus-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide supported on a titanium oxide substrate, iron-doped titanium oxide, carbon-doped titanium oxide, and fluorine-doped oxidation. Examples thereof include titanium, nitrogen-doped titanium oxide, aluminum-doped zinc oxide, and antimony-doped zinc oxide. The indium tin oxide includes indium-doped tin oxide and tin-doped indium oxide.

The conductive agent is not particularly limited as long as it has a conductive effect. For example, it is coated with metal particles (silver particles, copper particles, aluminum particles, etc.), metal oxides (particles mainly composed of ferric oxide, zinc oxide, indium oxide, titanium oxide, etc.) and conductive oxides. Examples thereof include conductive particle-containing polymers containing particles, conductive whiskers, carbon nanotubes, and the like.

As the other fibers, for example, conductive fibers can be mentioned.
The conductive fiber may have a structure in which the entire fiber has conductivity, or a part of the fiber may have conductivity, that is, it may have a cross-sectional shape such as a core sheath, a sandwich, or an eccentricity. The conductive fiber is not particularly specified, but for example, 6 nylon, 11 nylon, 12 nylon, 66 nylon, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexane terephthalate and copolymers thereof. And a part of the acid component (terephthalic acid) is replaced with isophthalic acid.

By incorporating a fiber containing a conductive fiber into the cloth, it is possible to efficiently release an electric current from the outside when the cloth is used for clothing.

As typical conductive fibers, Teijin's "Metalian" (trade name), Unitika Fiber's "Megana" (trade name), Toray's "Luana" (trade name), and Kuraray's "Cracabo" (trade name) Examples thereof include "NO SHOCK (registered trademark)" manufactured by Solcia, which is a core-sheath type composite fiber in which a conductive component is arranged in a sheath portion.

In addition, as other fibers, for example, functional fibers having infrared absorption and conductivity can be mentioned.
The functional fiber refers to, for example, a fiber having two kinds of functions, which is integrated by a cross-sectional shape such as a core sheath, a sandwich, or an eccentric, and for example, an infrared absorber is contained in the sheath portion. , A core-sheath type composite fiber in which a conductive agent such as a metal oxide-containing polymer is contained in the core portion is preferable. Further, a core-sheath type composite fiber having a sheath portion made of acrylic and a core portion made of a metal oxide-based particle-containing polymer, an eccentric core sheath type composite fiber, and the like are also preferably mentioned.

By incorporating a fiber containing an infrared absorber into the cloth, the infrared absorber can generate the thermal energy of the electric arc or the flame flash when the cloth is used for clothing and an electric arc accident or a flash fire occurs. It can absorb and suppress the heat energy that reaches the human body.

The foamed resin layer of the present invention forms an initiator and a carbonized skeleton with a urethane resin serving as a binder, ammonium polyphosphate particles as a dehydration carbonization catalyst, and melamine which decomposes and vaporizes during heat exposure to form a foamed structure. It preferably contains pentaerythritol.

The urethane resin (matrix resin) of the present invention is preferably a soft urethane containing a polyol and a polyisocyanate as main components, and particularly preferably a polyether polyol and a diisocyanate as main components.

The number average molecular weight of the polyol (polyether polyol) is preferably 3500 to 5500. If it is smaller than 3500, the weight per unit area of the hard segment becomes large and the flexibility of the resin itself is impaired, and the melt viscosity at the time of heat exposure is too high, which hinders foaming. If it is larger than 5500, the melt viscosity at the time of heat exposure is too low, so that it drip (liquefies without foaming) before carbonization.
If the carbon number of the diol component constituting the polyol (polyether polyol) is small, the flexibility of the resin itself is impaired and the carbon ratio is small, so that a carbonized foam layer cannot be sufficiently formed at the time of heat exposure. .. Further, if the number of carbon atoms is large, the melt viscosity at the time of heat exposure becomes low and drip occurs.

If the average particle size of the primary particle shape of the ammonium polyphosphate particles (flame retardant) is large, the dispersed state in the resin deteriorates, and the particles drip when exposed to heat.

In addition, when the average particle size of the dispersed particle size of the ammonium polyphosphate particles is large, when the resin is soft urethane, the polyurethane is thermally softened and the drip is formed before the dehydration carbide catalytic action of ammonium polyphosphate functions during heat exposure. appear.

Further, the polyol (polyether polyol) is preferably an aliphatic having a freezing point of 0 to 70 ° C.

Further, the carbon number of the diol component constituting the polyol (polyether polyol) is preferably 4 to 10 (more preferably 4 to 8). When the number of carbon atoms is 3 or less, not only the flexibility of the resin itself is impaired but also the carbon ratio is small, so that a carbonized foam layer cannot be sufficiently formed at the time of heat exposure. Further, when the number of carbon atoms is 10 or more, the melt viscosity at the time of heat exposure becomes low and drip occurs.

Examples of such a polyol (polyether polyol) include polytetramethylene ether glycol (PTMG).

Further, examples of the polyisocyanate (diisocyanate) include diphenylmethane diisocyanate (MDI). Examples of diphenylmethane diisocyanis (MDI) include 4,4-diphenylmethane diisocyanate (4,4-MDI), 2,4-diphenylmethane diisocyanate (2,4-MDI), and 2,2-diphenylmethane diisocyanate, which are generally called monomeric MDI. (2,2-MDI), polymeric MDI, crude MDI and the like can be mentioned.

The average particle size of the primary particle shape of the ammonium polyphosphate particles (flame retardant) is preferably 10 μm or less (more preferably 8 μm or less). If the average particle size is larger than 10 μm, the dispersed state in the resin deteriorates and drips when exposed to heat.

Further, the ammonium polyphosphate particles preferably have an average dispersed particle diameter of 10 μm or less (more preferably 8 μm or less). When the average particle size is larger than 10 μm, when the resin is soft urethane, the polyurethane is thermally softened and drip occurs before the dehydration carbonization catalytic action of ammonium polyphosphate functions during heat exposure.

The ammonium polyphosphate particles are preferably contained in an amount of 10 to 30 wt% (more preferably 15 to 25 wt%). If it is less than 10 wt%, a sufficient carbonization reaction does not occur, and if it is more than 30 wt%, there is a concern that the foamed resin layer may be peeled off due to a decrease in strength.

The melamine (foaming agent) is preferably contained in an amount of 5 to 15 wt% (more preferably 8 to 12 wt%). If it is less than 5 wt%, sufficient foaming cannot be obtained, and if it is more than 15 wt%, the foaming amount becomes excessive and the strength may decrease.

Pentaerythritol (carbon feeder) is preferably contained in an amount of 10 to 30 wt% (more preferably 20 to 25 wt%). If it is more than 30 wt%, it fluidizes when it exceeds the melting point of 260 ° C., which promotes the melt fluidity of the urethane resin, which is not preferable.

In the foamed resin layer, a volatile organic solvent such as toluene or acetone may be used as a viscosity modifier, if necessary.

The foamed resin layer can be formed by knife-coating on a release paper and heating to form a film, and then applying an adhesive to laminate it on the flame-retardant fiber layer, or by directly knife-coating the flame-retardant fiber layer and forming a heat-forming film. It is preferable that the flame-retardant fiber layer is fixed to the flame-retardant fiber layer by a method of heat-forming after printing using a gravure or a mesh screen. At that time, if it is necessary to increase the film thickness according to the strength of the exposed flame, the laminating method is used, and if it is necessary to emphasize comfort such as air permeability, a pattern with a partially flame-retardant fiber layer left is used. It is preferable to use the printing method.

In this case, the foamed resin layer is preferably formed discontinuously on the flame-retardant fiber layer. The discontinuity is, for example, a shape such as ripples, dots, lattices, and geometric patterns, and is preferably arranged randomly or aligned on the flame-retardant fiber layer. In other words, the foamed resin layer does not have to cover all of the flame-retardant fiber layer, and a part of the flame-retardant fiber layer may be exposed to the outside (heat source side). By being formed discontinuously, the softness and air permeability of the flame-retardant fiber layer can be maintained.

The flame-retardant laminate has a heat flux of 80 kW / m ² specified by ISO 9151 based on ISO 11612, and the sensor temperature rises by 24 ° C. ± 0.2 ° C. from the start of radiant heat exposure, and the HTI ₂₄ is 7 seconds or more. Is preferable (more preferably 8 seconds or longer, particularly preferably 12 seconds or longer).

The flame-retardant structure of the present invention can be used in arc protective clothing, flameproof protective clothing, work clothing, activity clothing, hats (including hoods, hoods, etc.), gloves (including arm covers, etc.), protective aprons, etc. When used in protective products such as protective members (corresponding to members that protect each part of the human body), it is preferable to further arrange a flame-retardant fiber layer on the outside of the foamed resin layer. That is, it is preferable to have a three-layer structure (three-layer laminate) in the order of the flame-retardant fiber layer, the foamed resin layer, and the flame-retardant fiber layer. By using the above-mentioned three layers, it is possible to protect the foamed resin layer having a relatively weak mechanical strength. In addition, these layer structures may be configured by a method of fixing by sewing or sticking to an adhesive.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.
(1) Flame Retardant Particle Size According to JIS Z 8825: 2013, the solvent was acetone, a 1 wt% concentration solution was dispersed by ultrasonic waves for 15 minutes, and the particle size distribution obtained using a laser diffraction particle size distribution measuring device was used. The particle size, which is 80% cumulative when the cumulative distribution is drawn from the small diameter side on a volume basis, was determined and used as the average particle size.
(2) Flame Retardant Dispersed Particle Diameter in Resin The resin is frozen so as not to be deformed, cut with a microtome, the cut surface is magnified 1000 times with a scanning electron microscope, and contained in the flame retardant with an X-ray microanalyzer. The distribution of phosphorus atoms was detected, and the distribution diameter was measured.
(3) Resin thickness Measured by JIS L 1096 A method. In the method of directly coating the flame-retardant fiber layer, the thickness of the flame-retardant fiber layer was subtracted after measuring the thickness of the flame-retardant structure.
(4) Resin coating amount (weight per unit area)
It was measured by the JIS L 1096 A method. In the method of directly coating the flame-retardant fiber layer, the weight of the flame-retardant fiber layer was subtracted after measuring the weight of the flame-retardant structure.
(5) Heat Transfer Evaluation Based on ISO11612, at a heat flux of 80 kW / m ² defined by ISO9151, the HTI ₂₄ was determined for the time during which the sensor temperature increased by 24 ° C ± 0.2 ° C from the start of radiant heat exposure.

[Example 1]
Flame-retardant fiber layer: Meta-based aramid (meta-type total aromatic polyamide fiber raw monofiber (manufactured by Teijin Co., Ltd., "Cornex" (registered trademark), average single fiber fineness 1.7 dtex, fiber length 51 mm), Para-type aramid (para-type total aromatic polyamide short fiber (manufactured by Teijin Co., Ltd., "Technora" (registered trademark), average single fiber fineness 1.7 dtex, fiber length 51 mm) mixed with a mixing ratio (weight ratio) of 95: 5 Using spun yarns (40-meter count twin yarns, count 40/2) blended in proportion, a fabric (woven fabric) with a 2/1 twill structure of 110 warp yarns / inch and 60 weft yarns / inch is produced by a known method. Obtained.

Foamed resin layer: Polytrimethylene glycol (molecular weight 3000, 4 carbon atoms) as a matrix resin polyol, diphenylmethane diisocyanate (MDI) as a diisocyanate, melamine (primary reagent) as a foaming agent, and pentaerythritol (primary reagent) as a carbon feeder. ) And ammonium polyphosphate particles as a flame retardant (Adecastab FP2100JC manufactured by ADEKA, pulverized to an average particle diameter of 10 μm or less using a ball mill) were mixed at the ratios shown in Table 1, diluted with toluene, and mixed with a mixer. Then, the mixed solution was knife-coated on a paper pattern and formed into a film at 80 ° C. to obtain a resin film. The coating amount (weight per unit area) of the obtained resin film was 0.12 g / cm ² , and the thickness was 1.5 mm.

Flame-retardant structure: A urethane-based adhesive was gravure-printed on the obtained foamed resin layer in a dot shape and adhered to the flame-retardant fiber layer.
The obtained flame-retardant structure was carbonized after the foamed resin layer was rapidly foamed (swelled) when exposed to a flame. In addition, HTI ₂₄ took 23 seconds and had excellent heat resistance. These results are summarized in Table 1.

[Example 2]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Foamed resin layer: The same as in Example 1 except that the coating amount of the resin film was 0.05 g / cm ² and the thickness was 0.75 mm.
Flame-retardant structure: Prepared in the same manner as in Example 1.
The obtained flame-retardant structure was carbonized after the foamed resin layer was rapidly foamed (swelled) when exposed to a flame. In addition, HTI ₂₄ took 12 seconds and had excellent heat resistance. These results are summarized in Table 1.

[Example 3]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Foamed resin layer: Polyhexamethylene glycol (molecular weight 3000, carbon number 6) was used as the polyol, and the amount of the resin film applied was 0.03 g / cm ² , and the thickness was 0.40 mm. Created in the same way.
Flame-retardant structure: Prepared in the same manner as in Example 1.
The obtained flame-retardant structure was carbonized after the foamed resin layer was rapidly foamed (swelled) when exposed to a flame. Further, HTI ₂₄ took 8.6 seconds and had excellent heat resistance. These results are summarized in Table 1.

[Comparative Example 1]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Resin layer: Prepared by changing the mixing ratio from the foamed resin layer of Example 1.
Flame-retardant structure: Prepared in the same manner as in Example 1.
In the obtained flame-retardant structure, the resin layer drip when exposed to flame and did not foam. These results are summarized in Table 2.

[Comparative Example 2]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Resin layer: The mixing ratio was changed from the foamed resin layer of Example 1. No film was formed at this mixing ratio.
Flame-retardant structure: Prepared in the same manner as in Example 1.
The obtained flame-retardant structure did not foam because the resin of the resin layer did not form a film. These results are summarized in Table 2.

[Comparative Example 3]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Resin layer: The mixing ratio was changed from the foamed resin layer of Example 1, and the mixture was prepared using ammonium polyphosphate particles having an average particle diameter of 15 μm.
Flame-retardant structure: Prepared in the same manner as in Example 1.
In the obtained flame-retardant structure, the resin layer ignited and drip when exposed to flame, and did not foam. These results are summarized in Table 2.

[Comparative Example 4]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Resin layer: It was prepared in the same manner as the foamed resin layer of Example 1 except that polydodecamethylene glycol (molecular weight 3000, carbon number 12) was used as the polyol.
Flame-retardant structure: Prepared in the same manner as in Example 1.
In the obtained flame-retardant structure, the resin layer drip when exposed to flame and did not foam. These results are summarized in Table 2.

[Comparative Example 5]
Flame-retardant fiber layer: Prepared in the same manner as in Example 1.
Resin layer: Prepared in the same manner as the foamed resin layer of Example 1 except that polyethylene glycol (molecular weight 3000, carbon number 2) was used as the polyol.
Flame-retardant structure: Prepared in the same manner as in Example 1.
In the obtained flame-retardant structure, the resin layer did not fire when exposed to flame. These results are summarized in Table 2.

[Comparative Example 6]
A flame-retardant structure was prepared using only the flame-retardant fiber layer.
Although the obtained flame-retardant structure was carbonized, the HTI ₂₄ was 4.8 seconds, and the heat resistance was insufficient. These results are summarized in Table 2.

Claims (9)

A flame-retardant fiber layer having a critical oxygen index (LOI) of 26 or more specified in the JIS L 1091 E-2 method, and a urethane resin containing a polyol having a number average molecular weight of 3500 to 5500 and polyisocyanate are included as binders. , A flame-retardant structure for protective clothing, characterized by having a foamed resin layer containing ammonium polyphosphate particles, melamine, and pentaerythritol. The flame-retardant structure for protective clothing according to claim 1, wherein the foamed resin layer contains 10 to 30 wt% of ammonium polyphosphate particles, 5 to 15 wt% of melamine, and 10 to 20 wt% of pentaerythritol. The flame-retardant structure for protective clothing according to claim 1 or 2, wherein the polyol is a polyether polyol and the polyisocyanate is a diisocyanate. The flame-retardant structure for protective clothing according to claim 3, wherein the diol component of the polyether polyol is an aliphatic structure having 4 to 10 carbon atoms and a freezing point of 0 to 70 ° C. The flame-retardant structure for protective clothing according to any one of claims 1 to 4, wherein the average particle size of the primary particle shape of the ammonium polyphosphate particles is 10 μm or less. The flame-retardant structure for protective clothing according to any one of claims 1 to 5, wherein the average particle size of the dispersed ammonium polyphosphate particles is 10 μm or less. The flame-retardant structure for protective clothing according to any one of claims 1 to 6, wherein the foamed resin layer is formed discontinuously. Difficulty in protective clothing according to any one of claims 1 to 7, wherein in the heat transfer evaluation defined by ISO 9151 based on ISO 11612, the time HTI ₂₄ is 7 seconds or more because the sensor temperature rises by 24 ° C. Flammable structure. Arc protective clothing, flameproof protective clothing, work clothing, activity clothing, hats, gloves, protective aprons, and protective members using the flame-retardant structure according to any one of claims 1 to 8. Any protective product selected from the group consisting of.