阅读说明：本技术 耐火构件 (Refractory component ) 是由 胜谷乡史 和志武洋祐 远藤了庆 水光俊介 于 2018-11-27 设计创作，主要内容包括：本发明提供膨胀性耐火构件,其是耐火性优异的耐火构件,并且在接近热源时、接触火焰时耐火构件发生膨胀而形成隔热层,由此表现出隔热功能,保护内容物。所述耐火构件至少由导热系数为4W/(m·K)以上的非连续增强纤维和阻燃性热塑性树脂构成,所述非连续增强纤维分散在耐火构件中。该耐火构件的膨胀后的空隙率为30％以上。(The invention provides an expandable refractory member which is a refractory member having excellent fire resistance, and which exhibits a heat insulating function and protects contents by forming a heat insulating layer by expanding the refractory member when approaching a heat source or when contacting a flame. The flame-retardant member is composed of at least a non-continuous reinforcing fiber having a thermal conductivity of 4W/(m.K) or more and a flame-retardant thermoplastic resin, and the non-continuous reinforcing fiber is dispersed in the flame-retardant member. The porosity of the expanded refractory member is 30% or more.)

1. A flame-retardant member comprising at least a flame-retardant thermoplastic resin and discontinuous reinforcing fibers having a thermal conductivity of 4W/(m.K) or more, the discontinuous reinforcing fibers being dispersed in the flame-retardant member,

the porosity of the expanded refractory member is 30% or more.

2. A refractory material having a thermal conductivity after expansion of 0.15W/(m.K) or less.

3. The refractory according to claim 1 or 2, wherein the thermal resistance of the expanded refractory is 0.05m²K/W or more.

4. The refractory member according to any one of claims 1 to 3, wherein the refractory member has a flexural modulus of elasticity of 3GPa or more and a flexural strength of 50MPa or more.

5. The flame-retardant member according to any one of claims 1 to 4, wherein the flame-retardant thermoplastic resin has a limiting oxygen index of 30 or more.

6. The flame-resistant member according to any one of claims 1 to 5, wherein the ratio of the discontinuous reinforcing fibers is 15 to 80% by weight with respect to the total amount of the resin matrix containing the flame-retardant thermoplastic resin and the discontinuous reinforcing fibers.

7. The refractory component according to any one of claims 1 to 6, wherein the discontinuous reinforcing fibers have an average fiber length of 2 to 50 mm.

8. The refractory component according to any one of claims 1 to 7, wherein the discontinuous reinforcing fibers are composed of at least one selected from carbon fibers, silicon carbide fibers, alumina fibers, ceramic fibers, basalt fibers, and metal fibers.

9. The fire resistant member according to any one of claims 1 to 8, wherein the flame retardant thermoplastic resin is composed of at least one selected from a polyetherimide resin, a polysulfone resin, a polyethersulfone resin, and a polyether ether ketone resin.

10. A method of manufacturing a refractory component according to any one of claims 1 to 9, the method comprising:

one or more mixed nonwoven fabrics are laminated, the mixed nonwoven fabrics are composed of at least powder or fiber flame-retardant thermoplastic resin and discontinuous reinforcing fiber with thermal conductivity of 4W/(m.K) or more, and are pressurized and heated at a temperature of the flow starting temperature of the thermoplastic resin or more, and then pressurized and cooled.

Technical Field

The present invention relates to a refractory member, and more particularly, to a refractory member having an expansibility.

Background

Conventionally, in order to improve fire resistance in members of beams, columns, aircraft, and automobiles of buildings, a combustible material is coated with a refractory material. As an example, there is a method of directly blowing asbestos or the like to a combustible member to provide fire-proof performance, but this has a problem in terms of safety such as a problem of dust during handling.

In addition, patent document 1 proposes a multilayer structure including a composite layer including glass fibers and a thermoplastic polymer material, and a woody matrix layer attached to the composite layer. Patent document 1 describes that when exposed to heat and flame, the composite material burns, decomposes, or decreases in viscosity, as a result of which a web of fibers is released and the web elastically expands. For example, patent document 1 describes that when a multilayer structure is held on a vertical flame, the time for the substrate material to reach 160 ℃ is 3.6 to 10.8 minutes in the presence of a composite material layer and 0 to 3.6 minutes in the absence of a composite material.

Disclosure of Invention

Problems to be solved by the invention

However, although the fire resistance test is performed in patent document 1, it is a test under an extremely weak flame, and is not sufficient as a fire resistance test of a practical level.

Accordingly, an object of the present invention is to provide a refractory member which is excellent in fire resistance even in a fire resistance test of a practical level, and which exhibits a heat insulating function by forming a heat insulating layer by expansion of the refractory member when the refractory member is brought close to a heat source or when the refractory member is brought into contact with a flame.

Means for solving the problems

As a result of intensive studies to solve the above problems, the present inventors have found that, when a flame-resistant member having a specific porosity when heated at a predetermined temperature is obtained by combining a non-continuous reinforcing fiber having a specific thermal conductivity and a flame-resistant thermoplastic resin, the flame-resistant member exhibits an extremely high flame resistance when brought close to a heat source or brought into contact with a flame, and also expands itself to form a heat-insulating layer, thereby exhibiting a heat-insulating function and protecting contents from the heat and flame, and have completed the present invention.

That is, the present invention can be configured as follows.

[ mode 1 ]

A flame-retardant member comprising at least a flame-retardant thermoplastic resin and a discontinuous reinforcing fiber having a thermal conductivity of 4W/(mK) or more (preferably 6W/(mK) or more, more preferably 8W/(mK) or more), wherein the discontinuous reinforcing fiber is dispersed in the flame-retardant member,

the porosity of the refractory after expansion (preferably after maximum expansion) is 30% or more { preferably 30 to 95%, more preferably 40 to 93%, further preferably 50% or more (for example, 50 to 90%), further preferably 60% or more, and particularly 70% or more }.

[ mode 2 ]

A refractory material, wherein the refractory material according to the above aspect 1 has a thermal conductivity of 0.15W/(mK) or less (preferably 0.13W/(mK) or less, more preferably 0.11W/(mK) or less) after expansion (preferably after maximum expansion).

[ mode 3 ]

The refractory according to mode 1 or 2, wherein the thermal resistance of the refractory after expansion (preferably after maximum expansion) is 0.05m²K/W or more (preferably 0.07 m)²K/W or more, more preferably 0.1m²K/W or more).

[ mode 4 ]

The refractory member according to any one of aspects 1 to 3, wherein the refractory member has a flexural elastic modulus of 3GPa or more (preferably 3.5GPa or more, and more preferably 4.0GPa or more) and a flexural strength of 50MPa or more (preferably 55MPa or more, and more preferably 60MPa or more).

[ means 5 ]

The flame-retardant member according to any one of aspects 1 to 4, wherein the flame-retardant thermoplastic resin has a limiting oxygen index of 30 or more (preferably 32 or more, and more preferably 35 or more).

[ mode 6 ]

The flame-retardant member according to any one of aspects 1 to 5, wherein the ratio of the discontinuous reinforcing fibers to the total amount of the resin base (resin component) containing the flame-retardant thermoplastic resin and the discontinuous reinforcing fibers is 15 to 80 wt% (preferably 17 to 75 wt%, and more preferably 20 to 70 wt%).

[ mode 7 ]

The refractory according to any one of aspects 1 to 6, wherein the discontinuous reinforcing fibers have an average fiber length of 2 to 50mm (preferably 3 to 50mm, more preferably 5 to 35mm, and most preferably 10 to 20 mm).

[ mode 8 ]

The refractory according to any one of modes 1 to 7, wherein the discontinuous reinforcing fibers are formed of at least one selected from carbon fibers, silicon carbide fibers, alumina fibers, ceramic fibers, basalt fibers, and metal fibers.

[ means 9 ]

The flame-retardant member according to any one of modes 1 to 8, wherein the flame-retardant thermoplastic resin is composed of at least one selected from a polyetherimide resin, a polysulfone resin, a polyethersulfone resin, and a polyether ether ketone resin.

[ mode 10 ]

The method for producing a refractory member according to any one of embodiments 1 to 9, comprising: one or more mixed nonwoven fabrics composed of a powdery or fibrous flame-retardant thermoplastic resin and discontinuous reinforcing fibers having a thermal conductivity of 4W/(m.K) or more (preferably 6W/(m.K) or more, more preferably 8W/(m.K) or more) are laminated, and the laminate is heated while being pressurized at a temperature of not lower than the flow initiation temperature of the thermoplastic resin, and then cooled while being pressurized.

Here, the expanded flame-resistant member is a flame-resistant member in a state in which a thermoplastic resin is melted or fluidized at a predetermined heating temperature and is expanded by the repulsive force of the fibers. The fire resistant member after maximum expansion is a fire resistant member in which a thermoplastic resin is melted or fluidized at a predetermined heating temperature and expanded to a state in which no thickness change is observed with naked eyes. The heating temperature is not particularly limited, and only the thermoplastic resin may be melted or fluidized, and for example, in the case of an amorphous resin, the temperature may be 100 ℃ higher than the glass transition temperature, and in the case of a crystalline resin, the temperature may be 30 ℃ higher than the melting point.

ADVANTAGEOUS EFFECTS OF INVENTION

The refractory member of the present invention is a refractory member having excellent fire resistance at a practical level, and can exhibit a heat insulating function by forming a heat insulating layer by expansion of the refractory member when the refractory member approaches a heat source or is brought into contact with flame.

Detailed Description

The present invention will be described in detail below. The flame-retardant member of the present invention is composed of a non-continuous reinforcing fiber having a high thermal conductivity and a flame-retardant thermoplastic resin, and the non-continuous reinforcing fiber is dispersed in the flame-retardant member. The flame-retardant member is not particularly limited as long as it can expand at a predetermined porosity when heated at a predetermined temperature, and for example, the flame-retardant member may be composed of a flame-retardant member having a structure in which discontinuous reinforcing fibers are dispersed in a flame-retardant thermoplastic resin and at least a part of intersections where the discontinuous reinforcing fibers intersect with each other are bonded to each other with the flame-retardant thermoplastic resin. As a method for bonding the discontinuous fibers with the flame-retardant thermoplastic resin, for example, a method may be used in which fibers made of a flame-retardant thermoplastic resin (hereinafter referred to as flame-retardant thermoplastic fibers) and discontinuous reinforcing fibers are formed into a mixed nonwoven fabric, the flame-retardant thermoplastic fibers are melted and then cooled to solidify the mixture, and the discontinuous reinforcing fibers are bonded to each other, or a method may be used in which a granular (or powder-granular) flame-retardant thermoplastic resin is contained in a nonwoven fabric of discontinuous reinforcing fibers, the thermoplastic resin is melted and then cooled to solidify the mixture, and the discontinuous reinforcing fibers are bonded to each other.

< discontinuous reinforcing fiber >

The discontinuous reinforcing fibers used in the present invention have a thermal conductivity of 4W/(m · K) or more, preferably 6W/(m · K) or more, and more preferably 8W/(m · K) or more. The upper limit is not particularly limited, and may be 1000W/(m.K) or less, 950W/(m.K) or less, or 900W/(m.K) or less.

By having such a thermal conductivity, heat is diffused along the fiber orientation direction even when the flame comes into contact with the flame, thereby preventing local overheating of the flame contact portion, suppressing combustion, and realizing excellent flame resistance. For example, when glass fibers having a low thermal conductivity are used as the discontinuous reinforcing fibers, the flame contact portion is locally overheated without heat diffusion, and thus such excellent flame resistance cannot be achieved.

The thermal conductivity of the discontinuous reinforcing fiber of the present invention is determined by a measurement method described later.

The discontinuous reinforcing fibers are not particularly limited as long as the effects of the present invention are not impaired, and examples of the discontinuous reinforcing fibers include inorganic fibers such as carbon fibers, silicon carbide fibers, alumina fibers, ceramic fibers, basalt fibers, and various metal fibers (e.g., gold, silver, copper, iron, nickel, titanium, stainless steel). These discontinuous reinforcing fibers may be used alone, or two or more kinds may be used in combination. Among them, carbon fibers, silicon carbide fibers, alumina fibers, ceramic fibers, basalt fibers, stainless steel fibers, and the like are preferable from the viewpoint of small temperature dependence of tensile elastic modulus.

The discontinuous reinforcing fibers used in the present invention preferably have a tensile elastic modulus of 10GPa or more, more preferably 30GPa or more, and most preferably 50GPa or more, from the viewpoint of rapidly expanding by repulsive force when approaching a heat source. The upper limit of the tensile modulus is not particularly limited, and may be about 1000 GPa.

In addition, from the viewpoint of achieving good resilience when approaching a heat source or when contacting a flame, the discontinuous reinforcing fibers are preferably fibers that retain an elastic modulus in a temperature range of 400 ℃ or less, and more preferably fibers that retain the elastic modulus in a temperature range of 600 ℃ or less. The tensile modulus of the fiber of the present invention can also be determined by the measurement method described below.

The discontinuous reinforcing fiber used in the present invention may have any length as long as it can achieve a predetermined porosity during heating, and the average fiber length of the single fibers is preferably 2 to 50mm, more preferably 3 to 50mm, even more preferably 5 to 35mm, and most preferably 10 to 20mm, from the viewpoint of improving the expansion rate of the refractory member and improving the process passability during production. With such an average fiber length, a high expansion ratio can be achieved, and sufficient heat insulation properties can be exhibited. If the average fiber length of the single fibers is too short, the elastic recovery due to the overlapping of the fibers becomes small, and a high expansion ratio cannot be obtained, and there is a possibility that sufficient heat insulation as a flame-resistant member cannot be obtained. In addition, when the average fiber length of the single fibers is too long, the fibers are excessively entangled with each other, and a process failure occurs in the production of the refractory member, so that the refractory member may not be uniformly expanded.

The average fiber length of the single fibers of the present invention is determined by the measurement method described below.

In addition, the average diameter of the discontinuous reinforcing fibers is preferably 2 to 30 μm, more preferably 4 to 25 μm, and still more preferably 6 to 20 μm, from the viewpoint of increasing the rebound resilience due to overlapping of the fibers and increasing the number of constituent fibers. When the average diameter is too small, the rebound due to overlapping of the fibers is small, and a high expansion ratio may not be obtained. If the average diameter is too large, the number of constituent fibers is reduced, and a high expansion ratio may not be obtained. The average diameter of the fiber of the present invention can be determined by the measurement method described later. It should be noted that in the case of discontinuous reinforcing fibers having a profiled cross section, the diameter thereof may be replaced by the circumscribed circle diameter.

The ratio of the discontinuous reinforcing fibers in the refractory member is preferably 15 to 80 wt%, more preferably 17 to 75 wt%, and still more preferably 20 to 70 wt% with respect to the total amount of the resin matrix and the discontinuous reinforcing fibers. If the weight ratio of the discontinuous reinforcing fibers is too small, the discontinuous reinforcing fibers forming the refractory may be insufficient, and a high expansion ratio may not be obtained. On the other hand, if the weight ratio of the discontinuous reinforcing fibers is too large, the amount of resin bonding the discontinuous reinforcing fibers to each other is insufficient, and there is a possibility that mechanical properties as a refractory cannot be obtained. The resin substrate may be composed of a flame-retardant thermoplastic resin and a binder component mixed as necessary.

In this case, the ratio (weight ratio) of the flame-retardant thermoplastic resin to the binder component may be, for example, 99.9/0.1 to 80/20, preferably 99/1 to 83/17, and more preferably 95/5 to 85/15.

< flame retardant thermoplastic resin >

The flame-retardant thermoplastic resin used in the present invention is not particularly limited as long as it can be used as a flame-retardant member, and the flame-retardant thermoplastic resin preferably has a limiting oxygen index (L OI) of 30 or more, more preferably 32 or more, further preferably 35 or more, and an upper limit of 95 or less, from the viewpoint of improving flame retardancy.

The limit oxygen index (L OI) of the flame retardant thermoplastic resin of the present invention is determined by the measurement method described later.

The flame-retardant thermoplastic resin used in the present invention may be a crystalline thermoplastic resin or an amorphous thermoplastic resin, and any of the flame-retardant members of the present invention may expand when brought close to a heat source or when brought into contact with a flame, thereby exhibiting a heat-insulating function. In particular, in order to protect contents such as combustible materials by covering the contents with a flame-retardant member, it is preferable to select a material plasticized with the flame-retardant thermoplastic resin in a temperature range in which the contents should be protected. If the flame-retardant thermoplastic resin is a crystalline thermoplastic resin, it is preferable to select a material having a melting point falling within the target temperature range, and if the flame-retardant thermoplastic resin is an amorphous thermoplastic resin, it is preferable to select a material having a glass transition temperature falling within the target temperature range.

In addition, from the viewpoint of maintaining the heat resistance of the structure of the refractory member even in a high-temperature environment, if the refractory member is a crystalline thermoplastic resin, the melting point is preferably 150 ℃ or higher, more preferably 175 ℃ or higher, and still more preferably 200 ℃ or higher. The glass transition temperature of the amorphous thermoplastic resin is preferably 100 ℃ or higher, more preferably 110 ℃ or higher, and still more preferably 120 ℃ or higher. The upper limit is not particularly limited, and if the thermoplastic resin is crystalline, the melting point is preferably 300 ℃ or lower, and if the thermoplastic resin is amorphous, the glass transition temperature is preferably 300 ℃ or lower.

The flame-retardant thermoplastic resin used in the present invention is not particularly limited, and may be used alone or in combination of two or more, and specific examples thereof include polytetrafluoroethylene resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, semi-aromatic polyamide resins, polyether ether ketone resins, polycarbonate resins, and polyarylate resins, and among them, from the viewpoint of mechanical properties, flame retardancy, heat resistance, moldability, and easy availability, it is preferable to use a polyetherimide resin, a polysulfone resin, a polyether sulfone resin, and a polyether ether ketone resin.

The flame-retardant thermoplastic resin used in the present invention may further contain an antioxidant, an antistatic agent, a radical inhibitor, a delustering agent, an ultraviolet absorber, a flame retardant, an inorganic substance (excluding the discontinuous reinforcing fibers), and the like, within a range not to impair the effects of the present invention. Specific examples of the inorganic substance include carbon black, graphite, carbon nanotubes, fullerenes, silica, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, silicates (talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, bentonite, aluminum silicate, etc.), metal oxides (magnesium oxide, aluminum oxide, zirconium oxide, titanium oxide, iron oxide, etc.), carbonates (calcium carbonate, magnesium carbonate, dolomite, etc.), sulfates (calcium sulfate, barium sulfate, etc.), hydroxides (calcium hydroxide, magnesium hydroxide, aluminum hydroxide, etc.), and the like.

The flame-retardant thermoplastic resin may be in various forms as long as it can disperse the discontinuous reinforcing fibers in the flame-retardant member. For example, the form of such particles, powder, fibers, and the like can be used. The flame-retardant thermoplastic resin in these forms can be produced by a known or conventional method.

In particular, when the flame-retardant thermoplastic resin is used in the form of fibers, the production of the flame-retardant thermoplastic fibers is not particularly limited, and a known melt spinning apparatus can be used. That is, the flame retardant thermoplastic resin can be obtained by melt-kneading pellets or powder of the flame retardant thermoplastic resin with a melt extruder, introducing the molten polymer into a spinning tube, measuring the melt with a gear pump, and winding the filament discharged from a spinning nozzle. The drawing speed in this case is not particularly limited, and may be suitably determined depending on the type of the flame-retardant thermoplastic resin, and it is not preferable to perform molecular orientation on the spinning line, and therefore drawing is preferably performed in the range of 500 to 4000 m/min. When the molecular weight is less than 500 m/min, it is not preferable from the viewpoint of productivity, and when the molecular weight is higher than 4000 m/min, not only molecular orientation sufficient to cause shrinkage at high temperature is performed, but also fiber breakage is likely to occur, which is not preferable.

The flame-retardant thermoplastic fiber obtained is preferably an undrawn fiber.

The single fiber fineness of the flame-retardant thermoplastic fiber is preferably 0.1 to 10 dtex. In order to obtain a refractory material having excellent mechanical properties and a high expansion ratio, it is preferable to uniformly disperse the discontinuous reinforcing fibers in the mixed nonwoven fabric which is a precursor. When the flame retardant thermoplastic fibers are used at the same weight ratio, the finer the single fiber fineness is, the more the number of flame retardant thermoplastic fibers constituting the mixed nonwoven fabric is, the more the discontinuous reinforcing fibers can be uniformly dispersed, but if the single fiber fineness is too small, the fibers tend to be entangled with each other in the nonwoven fabric production process, and the discontinuous reinforcing fibers may not be uniformly dispersed. Further, if the single fiber fineness is too large, the number of flame retardant thermoplastic fibers constituting the nonwoven fabric blend is reduced, and there is a possibility that the discontinuous reinforcing fibers cannot be uniformly dispersed. The single fiber fineness of the flame-retardant thermoplastic fiber is more preferably 0.2 to 9dtex, and still more preferably 0.3 to 8 dtex.

The single fiber fineness of the present invention is determined by the measurement method described later.

The average fiber length of the single fibers of the flame retardant thermoplastic fiber used in the present invention is preferably 0.5 to 60 mm. If the average fiber length is too short, fibers may fall off during the production of the nonwoven fabric, and particularly if the nonwoven fabric is produced by wet papermaking, the process passability may be deteriorated, for example, the drainability in the process may be deteriorated, which is not preferable. If the average fiber length is too long, the non-continuous reinforcing fibers may not be uniformly dispersed because of cohesion occurring in the nonwoven fabric production process, which is not preferable. More preferably 1 to 55mm, and still more preferably 3 to 50 mm. The cross-sectional shape of the fiber in this case is not particularly limited, and may be a round, hollow, flat, or star-shaped cross-section.

The average fiber length of the single fibers of the present invention is determined by the measurement method described below.

< Mixed non-woven Fabric >

The nonwoven fabric mixture used in the present invention preferably contains the resin component (particularly, a flame-retardant thermoplastic resin such as a flame-retardant thermoplastic fiber) in the nonwoven fabric mixture in a proportion of 20 to 85 wt%. If the proportion of the resin component (particularly, flame-retardant thermoplastic resin such as flame-retardant thermoplastic fiber) is too small, the amount of the resin component (particularly, the amount of the flame-retardant thermoplastic resin) in the production of the flame-retardant member may be small, and sufficient mechanical properties may not be obtained. In addition, when the proportion of the resin component (particularly, flame-retardant thermoplastic resin) is too large, the proportion of the discontinuous reinforcing fibers is reduced, and the expansion rate of the flame-resistant member is lowered, so that there is a possibility that sufficient heat insulation properties cannot be obtained. More preferably 25 to 83 wt%, and still more preferably 30 to 80 wt%.

The hybrid nonwoven fabric may contain a binder component (for example, binder fiber) and the like as necessary. Examples of the binder component include water-soluble polymer fibers such as polyvinyl alcohol fibers, thermofusible fibers such as PET fibers, para-aramid fibers, and pulp-like materials of wholly aromatic polyester fibers.

The method for producing the mixed nonwoven fabric used in the present invention is not particularly limited, and examples thereof include a spunlace method, a needle punching method, a steam jet method, a dry papermaking method, and a wet papermaking method (wet process). In particular, the wet papermaking method is preferable in terms of production efficiency and uniform dispersion of discontinuous reinforcing fibers in the nonwoven fabric. For example, in the wet papermaking method, an aqueous slurry containing the flame retardant thermoplastic fiber and the discontinuous reinforcing fiber may be prepared, and then the slurry may be subjected to a normal papermaking process. The aqueous slurry may contain a binder component (for example, a water-soluble polymer fiber such as a polyvinyl alcohol fiber, a thermofusible fiber such as a PET fiber, a pulp of a para-aramid fiber or a wholly aromatic polyester fiber), and the like. In order to improve the uniformity and the pressure-bonding property of paper, a binder may be applied by spray drying, and a hot-pressing step may be added after the wet papermaking step.

The weight per unit area of the mixed nonwoven fabric is not particularly limited, but is preferably 5 to 1500g/m²More preferably 10 to 1000g/m²More preferably 20 to 500g/m². When the weight per unit area is too small, the strength of the nonwoven fabric is low, and therefore, the process passability may be deteriorated. If the weight per unit area is too large, it may be difficult to finely adjust the porosity of the refractory member.

The weight per unit area in the present invention is obtained by the measurement method described later.

< refractory Member >

The flame-retardant member of the present invention is a flame-retardant member (or a flame-retardant composite) comprising at least discontinuous reinforcing fibers and a flame-retardant thermoplastic resin, wherein the discontinuous reinforcing fibers are dispersed in the flame-retardant member. The non-continuous reinforcing fibers can be obtained by a known or conventionally used production method when dispersed in the refractory.

For example, the flame-retardant member can be produced by laminating one or more sheets of the mixed nonwoven fabric, pressurizing and heating the nonwoven fabric at a temperature not lower than the flow initiation temperature of the flame-retardant thermoplastic fibers, and cooling the nonwoven fabric while pressurizing the nonwoven fabric. The method for heat-molding the mixed nonwoven fabric is not particularly limited, and it is preferable to use ordinary compression molding such as press molding, vacuum pressure bonding molding, and GMT molding. The molding temperature at this time may be set according to the flow initiation temperature and decomposition temperature of the flame retardant thermoplastic fiber to be used. For example, when the flame-retardant thermoplastic fiber is crystalline, the molding temperature is preferably in the range of [ melting point +100] ° c or higher than the melting point of the flame-retardant thermoplastic fiber. When the flame-retardant thermoplastic fiber is amorphous, the molding temperature is preferably in the range of not lower than the glass transition temperature of the thermoplastic fiber and not higher than [ glass transition temperature +200] ° c. If necessary, the preform may be preheated by an IR heater or the like before the thermoforming.

The pressure at the time of thermoforming is not particularly limited, but is usually 0.05N/mm²The above pressure. The time for the heat molding is not particularly limited, but the polymer may be deteriorated when exposed to a high temperature for a long time, and therefore, it is usually preferably within 30 minutes. The thickness and density of the obtained refractory material may be appropriately set according to the type of the discontinuous reinforcing fibers and the pressure applied. The shape of the obtained refractory member is not particularly limited, and may be appropriately set. The nonwoven fabric may be formed by stacking a plurality of nonwoven fabrics having different specifications or by arranging nonwoven fabrics having different specifications, respectively, and heating the resulting laminate.

When the flame-retardant member of the present invention comes close to a heat source or comes into contact with a flame, the flame-retardant thermoplastic resin in the flame-retardant member is heated and plasticized, and the curvature of the discontinuous fibers in the flame-retardant member is released, whereby the flame-retardant member expands. Therefore, when the refractory member approaches a heat source or comes into contact with a flame, the interior of the refractory member expands to form a void, thereby forming a heat insulating layer.

The refractory member of the present invention preferably has a flexural modulus of 3GPa or more and a flexural strength of 50MPa or more. The flexural modulus is more preferably 3.5GPa or more, and still more preferably 4.0GPa or more. The bending strength is more preferably 55MPa or more, and still more preferably 60MPa or more. The upper limit is not particularly limited, but a flexural modulus of 50GPa or less and a flexural strength of 500MPa or less are preferable. If the flexural modulus is too low, the rigidity of the refractory member may be insufficient. If the bending strength is too low, the durability as a refractory member may be insufficient. The flexural modulus and flexural strength of the present invention are determined by the measurement methods described below.

Since the flame-resistant member of the present invention can be expanded by the repulsive force of the fibers by melting or flowing the thermoplastic resin at a high temperature, the void ratio after expansion (preferably after maximum expansion) is 30% or more, preferably 30 to 95%, more preferably 40 to 93%, and further preferably 50 to 90%. For example, the heating at a high temperature may be performed at a temperature (Tg +100) ° c (in the case of an amorphous resin) 100 ℃ higher than the glass transition temperature (Tg) of the flame retardant thermoplastic resin, or may be performed at a temperature (Tm +30) ° c (in the case of a crystalline resin) 30 ℃ higher than the melting point (Tm). The porosity after expansion (preferably after maximum expansion) is particularly preferably 50% or more, preferably 60% or more, and more preferably 70% or more. If the porosity after expansion is too small, sufficient voids are not generated in the refractory member, and the heat insulating layer is not formed, so that the heat insulating property may be deteriorated. In addition, if the porosity after expansion is too large, the mechanical properties of the refractory member may be insufficient.

The porosity after expansion of the present invention is a value of the porosity of the fire resistant member in an expanded state calculated according to JIS K7075 "fiber content and void fraction test of carbon-reinforced plastics", and particularly the porosity after maximum expansion is a porosity of the fire resistant member heated to a thickness without change. These can also be determined by the measurement method described later.

The refractory member of the present invention may be formed in various thicknesses according to the application, and the thickness before expansion may be, for example, about 0.5 to 10mm, and preferably about 0.7 to 8mm, from the viewpoint of weight reduction. The thickness after expansion (preferably after maximum expansion) may be, for example, about 2 to 30mm, and preferably about 4 to 25 mm. The thickness of the refractory member of the present invention is determined by the measurement method described below.

The thermal conductivity of the refractory of the present invention after expansion (preferably after maximum expansion) may be 0.15W/(m · K) or less, preferably 0.13W/(m · K) or less, and more preferably 0.11W/(m · K) or less. When the thermal conductivity after expansion is too high, the heat is likely to reach the inside of the refractory member when approaching a heat source or when contacting a flame, and the function of protecting the contents is insufficient. The thermal conductivity after expansion of the present invention is measured according to JIS a 1412-2 "measuring method of thermal resistance and thermal conductivity of thermal insulation material — part 2: the heat conductivity coefficient of the expanded refractory member calculated by the heat flow meter method (HFM method), particularly the heat conductivity coefficient after the maximum expansion, is the heat conductivity coefficient of the refractory member heated to have no thickness change. These can also be determined by the measurement method described later.

In the present invention, the degree of expansion in the refractory member can be expressed by, for example, a maximum expansion ratio and determined by a measurement method described later. The maximum expansion rate of the refractory of the present invention is preferably 250% or more, more preferably 300% or more, and still more preferably 350% or more. If the maximum expansion ratio is too small, a sufficient space cannot be formed inside the refractory member when the refractory member approaches a heat source or comes into contact with a flame, and the heat insulating layer cannot be formed, so that the heat insulating property may be poor. The upper limit is not particularly limited, but is preferably 1000% or less from the viewpoint of maintaining the mechanical properties of the refractory.

The maximum expansion ratio of the present invention is obtained by a measurement method described later.

The thermal resistance after expansion (preferably after maximum expansion) of the refractory component of the invention is preferably 0.05m²K/W or more, more preferably 0.07m²K/W or more, more preferably 0.1m²K/W or more. The upper limit of the thermal resistance is not particularly limited, and may be 5m²K/W. If the thermal resistance after expansion is too low, the heat is likely to reach the inside of the refractory member when the refractory member approaches a heat source or comes into contact with a flame, and the function of protecting the contents may be insufficient.

In the expanded refractory member of the present invention, the thermal resistance after expansion is a value calculated by the thickness (m) after expansion/the thermal conductivity (W/(m · K)) after expansion, and particularly the thermal resistance after maximum expansion is the thermal resistance of the refractory member heated to a temperature at which there is no thickness change. These can also be determined by the measurement method described later.

The limit oxygen index (L OI) of the refractory of the present invention is preferably 30 or more, more preferably 32 or more, and still more preferably 34 or more, and if L OI is too low, the refractory is not sufficiently refractory and the refractory itself is liable to ignite when it comes into contact with a heat source or a flame, and therefore it is not preferable, and it is noted that the upper limit is not particularly limited, and preferably 90 or less, more preferably 70 or less, and still more preferably 50 or less.