JP7355351B2 - Fire-resistant resin molded product, fire-resistant structure of structural member, construction method of fire-resistant structural member, and manufacturing method of fire-resistant resin molded product - Google Patents

Description

The technology disclosed in this specification relates to a fire-resistant resin molded product, a fire-resistant structure of a structural member, and a method of constructing a fire-resistant structural member.

As a fire-resistant coating material for covering building materials such as steel frames, a coating material made into a sheet by kneading a binder, a flame retardant, a foaming agent, a carbonized material, a filler, etc. has been proposed (Patent Document 1) reference). When this covering material is exposed to high temperatures due to a building fire, it foams and carbonizes to form a heat insulating layer, which protects the building materials.

International Publication No. 2013/008819

However, in the above-mentioned covering materials, when trying to increase the content of fillers, etc. in order to withstand flames in the event of a fire and maintain the shape of the heat insulating layer, the content of binder becomes relatively low. Therefore, there are problems such as the fluidity of the mixture becoming low and kneading becoming difficult, and there is room for improvement in order to achieve both sufficient fire resistance and ease of manufacture.

The fire-resistant resin molded product disclosed herein is composed of a binder made of a synthetic resin and a non-binder that is a component other than the binder, and the non-binder is composed of ammonium polyphosphate and polyvalent It contains alcohol and titanium oxide, and the amount of the non-binder is 240 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder.

A fire-resistant resin molded product having the composition as described above can be molded into a desired shape (pellet, sheet, etc.) and is therefore easy to construct. In addition, in order to form a sufficiently thick insulation layer in the event of a fire and increase the effect of delaying the conduction of combustion heat through an endothermic reaction, it is better to have a large content of ammonium polyphosphate or polyhydric alcohol. In order to suppress dripping and maintain strength, it is better to have a large content of titanium oxide, but if the content of these components is increased, the content of the binder will be relatively small, which may cause problems during manufacturing. Kneading becomes difficult. If the amount of the non-binder is 240 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder, both fire resistance and ease of kneading during production can be achieved.

In the above fire-resistant resin molded article, the oil absorption amount of the titanium oxide may be 15 g/100 g or more and 25 g/100 g or less.

If the specific surface area of the titanium oxide used is too small, there is a risk that the effect of maintaining the strength of the heat insulating layer by preventing the heat insulating layer formed from dripping from the structural member during a fire and maintaining the strength of the heat insulating layer may not be achieved. On the other hand, if the specific surface area of the titanium oxide used is too large, kneading becomes difficult. When the oil absorption amount of titanium oxide is 15 g/100 g or more and 25 g/100 g or less, it is possible to maintain both the strength of the heat insulating layer and the ease of kneading. Note that in this specification, oil absorption means that measured in accordance with JIS K5101-13.

Further, the fireproof structure of a structural member disclosed in this specification includes a structural member having an insertion hole through which another member can be inserted, and a fireproof resin layer disposed on the inner peripheral surface of the insertion hole, The fire-resistant resin layer is composed of a binder made of a synthetic resin and a non-binder which is a component other than the binder, and the non-binder comprises ammonium polyphosphate, polyhydric alcohol, and titanium oxide. The amount of the non-binder is 240 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder.

In the fireproof structure of the structural member, the structural member includes a steel beam having a through hole, and a reinforcing member attached to the steel beam, the reinforcing member having a thread on an outer peripheral surface, and the reinforcing member having a thread through the through hole. an insertion member that is inserted into the hole; and a ring member that has a screw hole, is fixed to the insertion member by screwing, and is arranged along the peripheral edge of the through hole in the steel beam, The insertion member may have the insertion hole.

Furthermore, the method for constructing a fire-resistant structural member disclosed in this specification includes a kneading step of kneading a binder made of a synthetic resin and a non-binder that is a component other than the binder, and A molding step in which the kneaded material is formed into a sheet shape, and the molded product obtained in the molding step is attached to the inner circumferential surface of the insertion hole of a structural member having an insertion hole through which another member can be inserted, thereby making it fireproof. in the kneading step, the non-binder contains ammonium polyphosphate, polyhydric alcohol, and titanium oxide, and based on 100 parts by mass of the binder. , the amount of the non-binder is 240 parts by mass or more and 365 parts by mass or less.

According to the fire-resistant structure of the structural member and the construction method of the fire-resistant structural member having the above-described configuration, when a fire occurs, the fire-resistant resin layer foams, expands, and carbonizes to form a heat insulating layer. This heat insulating layer fills the gap between the edge of the insertion hole and other members, thereby suppressing the transfer of heat to the structural member and suppressing the spread of flame and heat through the insertion hole.

Here, in order to avoid difficulty in inserting other parts, the thickness of the fire-resistant resin layer is made thinner to a certain extent, and during construction, there is enough space between the other parts to be inserted and the fire-resistant resin layer. It is preferable that this is ensured. On the other hand, in order to suppress the transfer of heat to structural members in the event of a fire, and to ensure that the heat insulating layer fills the gap between the inner peripheral surface of the insertion hole and other members to some extent and exhibits sufficient fire resistance, it is necessary to have a sufficient thickness. It is desirable that a heat insulating layer be formed. The fire-resistant resin layer with the above composition has a sufficiently large expansion ratio (the ratio of the thickness after foaming to the thickness before foaming), so it is possible to avoid the difficulty of inserting other parts and to achieve the necessary fire resistance. It is possible to achieve both ensuring performance and ensuring performance.

According to the fire-resistant resin molded product, the fire-resistant structure of a structural member, and the construction method of a fire-resistant structural member disclosed in this specification, sufficient fire resistance performance and ease of manufacture can be achieved at the same time.

A partially enlarged perspective view of a structural member in an embodiment A partially enlarged exploded perspective view of a structural member in an embodiment Cross-sectional view of a fireproof structure of a structural member in an embodiment Partially enlarged exploded perspective view of a structural member in a modified example Cross-sectional view of the fireproof structure of the structural member in a modified example

Embodiments will be described with reference to FIGS. 1 to 3. The fire-resistant resin molded product of this embodiment is manufactured by kneading a binder made of synthetic resin and a non-binder, which is a component other than the binder, and molding it into an arbitrary shape. It is suitably used as a fire-resistant coating material for covering construction objects that require fire resistance. The non-binder includes ammonium polyphosphate as a flame retardant, polyhydric alcohol as a carbonizing agent, and titanium oxide as a thickener. This fire-resistant resin composition foams and carbonizes due to the heat of combustion during a fire, forming a heat insulating layer.

The type of synthetic resin used as the binder is not particularly limited, but includes ethylene copolymer resins such as EVA (ethylene-vinyl acetate copolymer) and EEA (ethylene-ethyl acetate copolymer), vinyl chloride, and vinyl chloride. Vinyl chloride resin such as vinyl acetate copolymer, synthetic rubber such as butyl rubber, styrene-butadiene rubber, etc. can be used. In particular, it is preferable to use an ethylene copolymer resin which has excellent kneading properties. When EVA is used as the binder, the VA ratio (vinyl acetate content) is preferably 10 to 20% in order to obtain a sufficient expansion ratio.

Among the non-binding agents, ammonium polyphosphate is a flame retardant, and is dehydrated and condensed by the combustion heat during a fire and foams. This dehydration condensation is an endothermic reaction, and this endothermic reaction can delay the conduction of combustion heat during a fire to a covered object such as a steel frame. The endothermic reaction is a deammonification reaction of ammonium polyphosphate.

Polyhydric alcohol is a carbonizing agent, and like ammonium polyphosphate, it undergoes dehydration condensation and foaming due to the heat of combustion during a fire. The type of polyhydric alcohol is not particularly limited, but pentaerythritol can be preferably used.

Titanium oxide is a thickener that prevents the heat insulating layer formed in the event of a fire from dripping from the object to be constructed, thereby maintaining the strength of the heat insulating layer. The larger the specific surface area of the titanium oxide used, the greater the effect of suppressing dripping, but it becomes difficult to knead during production. For this reason, it is preferable that the oil absorption amount of titanium oxide measured in accordance with JIS K5101-13 is 15 g/100 g or more and 25 g/100 g or less.

In addition to the above, the non-binding agent may also contain inorganic fibers (ceramic fibers, rock wool, etc.), mold release agents (fatty acid esters), lubricants, processing aids (polycarbodiimide, etc.), and the like.

In order to form a sufficiently thick insulation layer in the event of a fire and increase the effect of delaying the conduction of combustion heat through an endothermic reaction, it is better to have a large content of ammonium polyphosphate or polyhydric alcohol. In order to increase the fall-off suppressing effect, it is better to have a larger content of titanium oxide. However, when the content of these components is increased, the content of the binder becomes relatively small, making kneading during production difficult. If the amount of the non-binder is 240 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder, both fire resistance and ease of kneading during production can be achieved.

It is preferable that the fire-resistant resin molded article of this embodiment does not contain a blowing agent such as melamine. The decomposition temperature of these blowing agents is generally higher than that of ammonium polyphosphate or polyhydric alcohol, so the foaming of the blowing agent weakens the insulation layer that is once formed by the foaming of ammonium polyphosphate or polyhydric alcohol. It's for a reason.

The fire-resistant resin molded product of this embodiment is produced by melt-kneading the above-mentioned materials using, for example, a single-screw extruder or a twin-screw extruder, extruding the resulting kneaded product into a string or rod shape, and cooling the strand with water. Pellets obtained by pelletizing may also be used, such as melt-kneading the above materials using a Banbury mixer or a kneader mixer, forming the resulting kneaded product into a plate shape using a stretching roll, etc., and then forming it into a rod shape. It may be pellets obtained by cutting and pelletizing, or it may be a molded product obtained by molding the pellets obtained by these methods into an arbitrary shape by a known molding method such as press molding, extrusion molding, or injection molding. Alternatively, it may be a molded product formed by molding a melt-kneaded product into an arbitrary shape by a known molding method without pelletizing it.
In particular, a configuration in which the non-binder containing ammonium polyphosphate, polyhydric alcohol, and titanium oxide is 240 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder is a fire-resistant resin composition. When the material is a pellet, it is possible to avoid difficulty in kneading the material and breakage of the strands, which is preferable. Further, it is more suitable when producing pellets using a twin-screw extruder.

An example in which the fire-resistant resin molded product of this embodiment is suitably applied to the fire-resistant structure of a structural member will be described below.

As shown in FIGS. 1 and 2, the structural member 10 includes a steel beam 11 having a through hole 12, and a reinforcing member 21 that is attached to the steel beam 11 and reinforces a portion around the through hole 12. The steel beam 11 is an H-beam, and as shown in FIG. 3, is placed under the concrete slab S. The reinforcing member 21 includes a sleeve pipe 22 (corresponding to the insertion member) passed through the inside of the through hole 12, and two ring steel members 25 (ring members) joined to the sleeve pipe 22 and welded to the steel beam 11. ). As shown in FIG. 2, the sleeve tube 22 is a short cylindrical member having an outer diameter that is approximately equal to or slightly smaller than the diameter of the through hole 12, and the inner space of the tube corresponds to the insertion hole 23. A thread 24 is provided on the outer peripheral surface of the sleeve tube 22 . As shown in FIG. 2, each of the two ring steel members 25 is a ring-shaped plate member having a screw hole 26, and can be fixed to the sleeve pipe 22 by screwing. Each ring steel material 25 has a plurality of weld holes 27 arranged so as to surround the screw hole 26. The welding hole 27 is a hole for performing plug welding.

The sleeve tube 22 is passed through the through hole 12 with both ends protruding from the plate surface of the steel beam 11, respectively. The two ring steel members 25 are arranged to sandwich the steel beam 11, are fixed by being screwed to the sleeve pipe 22, and are further joined to the steel beam 11 by plug welding. As shown in FIG. 3, a fire-resistant resin layer 30 is disposed on the inner peripheral surface of the insertion hole 23 over the entire circumference. The fire-resistant resin layer 30 is a layer formed by pasting a sheet-shaped fire-resistant resin molded product having the above configuration onto the inner circumferential surface of the insertion hole 23 . One end of the sleeve pipe 22 slightly protrudes outward from the surface of one of the ring steel members 25 (the surface opposite to the steel beam 11), and one end of the fireproof resin layer 30 protrudes further outward than that. It stands out. The same goes for the other end.

An example of a method for constructing a fireproof structural member as described above will be described below.

First, the materials for the above-described fire-resistant resin molding are kneaded using a twin-screw extruder (kneading step). Pellets are obtained by extruding the obtained kneaded material into a string or rod shape, cooling the strand with water, and pelletizing it. The pellets are put into a single-screw extruder and formed into a sheet having a width of 60 to 120 mm and a thickness of 3 mm (molding step). Although it is possible to form the melt-kneaded product into a sheet without pelletizing it, from the viewpoint of simplifying production equipment and processes, it is preferable to form the melt-kneaded product into a sheet through pellets.
The obtained sheet-like molded product is attached to the inner circumferential surface of the insertion hole 23 of the sleeve pipe 22 in the structural member 10 having the above configuration to form the fire-resistant resin layer 30 (construction step).
Thereafter, a fireproof coating R may be formed on the surface of the steel beam 11 using sprayed rock wool, as shown in FIG.

As shown in FIG. 3, a pipe P for passing electrical wiring and the like is inserted into the insertion hole 23 provided with the fireproof resin layer 30. As shown in FIG. In normal times when a fire is not occurring, there is a certain amount of clearance between the inner circumferential surface of the fire-resistant resin layer 30 and the outer circumferential surface of the pipe P.

When a fire occurs, the fireproof resin layer 30 foams, expands, and carbonizes to form a heat insulating layer. This heat insulating layer suppresses the transfer of heat to the structural members, and also fills the gap between the inner peripheral surface of the insertion hole 23 and the pipe P to some extent, thereby suppressing the spread of flame and heat through the insertion hole 23. .

In order to avoid complicating the work of inserting the pipe P, the thickness of the fire-resistant resin layer 30 at the time of construction is made thin to some extent (for example, 4 mm or less), and there is a sufficient space between the pipe P to be inserted and the fire-resistant resin layer 30. It is preferable that a sufficient gap be ensured. On the other hand, in order for the heat insulating layer to suppress the transfer of heat to the structural members in the event of a fire, and to fill the gap between the inner circumferential surface of the insertion hole 23 and the pipe P to some extent, and to exhibit sufficient fire resistance performance, a sufficient thickness is required. It is desirable to form a heat insulating layer with a thickness (for example, 20 mm or more). The fire-resistant resin molded product of this embodiment has a sufficiently large expansion ratio (the ratio of the thickness after foaming to the thickness before foaming), so it is possible to avoid complication of the work of inserting the pipe P and to achieve the necessary fire resistance. It is possible to achieve both ensuring performance and ensuring performance.

<Test example>
[Equipment and materials used]
As a twin-screw kneading extruder, "HYPERKTX" manufactured by Kobe Steel, Ltd. was used. As a single screw extruder, "SE" manufactured by Toshiba Machine Co., Ltd. was used.
EVA (ethylene-vinyl acetate copolymer) resin, PP (polypropylene) resin, EEA (ethylene-ethyl acetate copolymer) resin, or vinyl chloride resin was used as the binder.
Among the non-binding agents, ammonium polyphosphate was used as a flame retardant, pentaerythritol as a carbonizing agent, titanium oxide as a thickener, melamine as a blowing agent, fatty acid ester as a processing aid, and adipic acid polyester as a plasticizer.

[Test method]
1) Test examples 1, 3 to 9
Each component shown in Table 1 was melt-kneaded using a twin-screw kneading extruder, and the molten resin extruded into a strand was cooled with water and cut into 5 mm lengths using a pelletizer to form pellets. The temperature setting of the extruder was 160°C. Pellet moldability was evaluated as ○ if the product could be molded into pellets without any problems, △ if the strands broke and could not be continuously produced, and × if the product could not be extruded from the extruder and could not be formed into pellets.

Next, the obtained pellets were melted and extruded using a single screw extruder to form a sheet having a thickness of 2 mm and a width of 20 mm. The cylinder temperature of the extruder was 120°C, and the mold temperature was 140°C.

Subsequently, the obtained sheet was attached to a steel plate with double-sided tape to prepare a test specimen, and the sheet was placed vertically in an electric furnace and heated at 800° C. for 2 hours to form a heat insulating layer. The shape retention of the heat insulating layer was evaluated as ○ if the heat insulating layer did not collapse without applying force, and × if it collapsed easily. The expansion ratio was also measured. Furthermore, it was evaluated whether the heat insulating layer did not sag after heating was completed. Items that remained in almost the same position as before heating were rated as ○, items that were not in the same position but had some deviation of the top were rated as △, and items that were dripping into the electric furnace were rated as ×. The results are shown in Table 1.

2) Test examples 2 and 10
The components shown in Table 1 were kneaded using a pressure kneader, processed into a 5 mm thick sheet using open rolls, and then cut into pellets. The rest is the same as 1) above.

3) Test examples 11 to 20
The components shown in Table 2 were kneaded using an open kneader, and then hot pressed (manually) at 150° C. to form a sheet. The obtained sheet was attached to a steel plate with double-sided tape to prepare a test specimen, and the shape retention and dripping of the heat insulating layer were evaluated in the same manner as in 1) above. The expansion ratio was also measured. The results are shown in Table 2.

Note that the units of numerical values indicating the blending ratio of each component in Tables 1 and 2 are parts by mass.

[Results and discussion]
In Test Examples 1 to 6, in which the amount of the non-binder was 240 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder, the kneaded product could be well formed into pellets. Furthermore, the heat insulating layer maintained its shape well, and no dripping was observed. The foaming ratio is 5 times to 12 times, and for example, when placed on the inner peripheral surface of an insertion hole in a structural member, it is possible to avoid complicating the work of inserting piping and to ensure the necessary fire resistance performance. It was enough to make both work compatible.

In Test Examples 7 and 10 in which the amount of non-binder was greater than 365 parts by mass, it was difficult to knead the materials and pellets could not be obtained. Further, in Test Examples 8 and 9 in which the amount of the non-binder was less than 240 parts by mass, the expansion ratio was not sufficient or sagging of the heat insulating layer was observed.

In order to achieve a well-balanced performance of maintaining the shape of the heat insulating layer, sufficient expansion ratio, and suppressing the dripping of the heat insulating layer, 120 to 185 parts by mass of ammonium polyphosphate and 40 parts by mass of pentaerythritol were added to 100 parts by mass of the binder. It was considered preferable that the amount of titanium oxide be 60 to 95 parts by weight.

<Modified example>
As in the structural member 40 shown in FIGS. 4 and 5, the reinforcing member 41 may be composed of two flanged tubes 42. Each flanged tube 42 has an inner diameter approximately equal to the inner diameter of the through hole 12, and includes a cylindrical tube portion 43 that is open at both ends, and a flange portion that projects outward from the opening edge of one opening of the tube portion 43. 44. Each flanged tube 42 is arranged such that the flange portion 44 abuts the peripheral edge of the through hole 12 in the steel beam 11, and is fixed to the steel beam 11 by welding.

A fire-resistant resin layer 45 similar to that of the above embodiment is disposed over the entire circumference of the cylindrical portions 43 of the two flanged cylinders 42 and the inner peripheral surface of the through hole 12. One end of the fire-resistant resin layer 45 slightly protrudes outward from one end of one cylindrical portion 43 (the edge on the opposite side to the flange portion 44). The same goes for the other end.

<Other embodiments>
The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, but also includes various aspects such as the following.
(1) In the above embodiment, the reinforcing member 21 includes the sleeve pipe 22 and the ring steel material 25, but the structure of the reinforcing member is not limited to the above embodiment. For example, the reinforcing member may include a sleeve pipe. However, the two ring steel members may be joined to the steel beam only by welding. Alternatively, the reinforcing member may include only one ring of steel welded to one side of the steel beam. Alternatively, the reinforcing member may be a steel plate having a hole through which the pipe can be inserted, and may be joined to the steel beam by welding. In these cases, a fire-resistant resin layer may be placed on the inner peripheral surface of the through hole of the steel beam and the hole of the ring steel material or iron plate.
Further, the reinforcing member may be a steel pipe through which the pipe can be inserted, and may be joined by welding to the inner circumferential surface of the through hole of the steel beam. In this case, a fire-resistant resin layer may be placed on the inner peripheral surface of the steel pipe.
Moreover, the steel beam does not need to be provided with a reinforcing member. In that case, a fire-resistant resin layer may be placed on the inner peripheral surface of the through-hole of the steel beam.

(2) The fire-resistant resin composition can be used for various purposes by molding it into a desired shape. For example, it can be formed into a sheet and used as a fireproof coating for steel structures. In addition, it can be formed into a tape and placed in gaps between window frames, door frames, etc., and expanded in the event of a fire to fill the void and prevent flames from penetrating the back side. It can also be used as a fireproof covering tape to prevent resin frames or wooden frames from being chucked by combustion heat in the event of a fire. It can also be formed into a plate shape and used as a lightweight fireproof shutter. It can also be formed into a film and used as a film that suppresses combustion when a storage battery such as a lithium ion battery catches fire, or a sheet that protects from sparks during welding. In addition, we also offer automotive parts that are molded into an appropriate shape and placed on the outer surface of hydrogen or gasoline tanks to prevent ignition from igniting due to temperature rise in the event of a fire; Sometimes it can also be used as a part to protect the inside of a living room.

(3) In the above embodiment, the end of the fire-resistant resin layer 30 protrudes from the sleeve tube 22, but the end surface of the fire-resistant resin layer may be flush with the end surface of the sleeve tube. Similarly, in the modified example, the end surface of the fire-resistant resin layer may be flush with the end surface of the cylindrical portion.

10, 40...Structural member 11...Steel beam 12...Through hole 21, 41...Reinforcement member 22...Sleeve pipe (insertion member)
23...Insertion hole 24...Thread 25...Ring steel material (ring member)
26...Screw holes 30, 45...Fireproof resin layer

Claims (6)

A fire-resistant resin molded product formed by melt-kneading,
Consisting of a binder made of synthetic resin and a non-binder that is a component other than the binder,
The non-binding agent includes ammonium polyphosphate, polyhydric alcohol, and titanium oxide,
the binder is an ethylene copolymer resin,
The amount of the non-binder is 230 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder,
The titanium oxide is 60 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass of the binder,
The ammonium polyphosphate is 120 parts by mass or more and 185 parts by mass or less with respect to 100 parts by mass of the binder,
A fire-resistant resin molded product with an expansion ratio of 5 to 12 times after heating at 800°C for 2 hours. The fire-resistant resin molded article according to claim 1, wherein the titanium oxide has an oil absorption amount of 15 g/100 g or more and 25 g/100 g or less. a structural member having an insertion hole through which another member can be inserted;
and a fire-resistant resin layer disposed on the inner circumferential surface of the insertion hole,
The fire-resistant resin layer is
Consisting of a binder made of synthetic resin and a non-binder that is a component other than the binder,
The non-binding agent includes ammonium polyphosphate, polyhydric alcohol, and titanium oxide,
the binder is an ethylene copolymer resin,
The amount of the non-binder is 230 parts by mass or more and 365 parts by mass or less with respect to 100 parts by mass of the binder,
The titanium oxide is 60 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass of the binder,
The ammonium polyphosphate is 120 parts by mass or more and 185 parts by mass or less with respect to 100 parts by mass of the binder,
A fireproof structure of a structural member, wherein the foaming ratio of the fireproof resin layer after heating at 800° C. for 2 hours is 5 to 12 times. The structural member includes a steel beam having a through hole and a reinforcing member attached to the steel beam,
The reinforcing member has a screw thread on an outer circumferential surface, an insertion member that is inserted into the through hole, and a screw hole, and is fixed to the insertion member by screwing, and a ring member disposed along the peripheral edge of the hole;
The fireproof structure of a structural member according to claim 3, wherein the insertion member has the insertion hole. a kneading step of kneading a binder made of a synthetic resin and a non-binder that is a component other than the binder;
a molding step of molding the kneaded material obtained in the kneading step into a sheet shape;
a construction step of forming a fire-resistant resin layer by pasting the molded product obtained in the molding step on the inner peripheral surface of the insertion hole of a structural member having an insertion hole through which another member can be inserted;
In the kneading step, the non-binder contains ammonium polyphosphate, polyhydric alcohol, and titanium oxide, and the binder is an ethylene copolymer resin, and based on 100 parts by mass of the binder, The non-binder is 230 parts by mass or more and 365 parts by mass or less, and the titanium oxide is 60 parts by mass or more and 95 parts by mass or less based on 100 parts by mass of the binder. A method for constructing a fire-resistant structural member, wherein the ammonium polyphosphate is 120 parts by mass or more and 185 parts by mass or less, and the foaming ratio of the fire-resistant resin layer after heating at 800° C. for 2 hours is 5 to 12 times. a kneading step of kneading a binder made of a synthetic resin and a non-binder that is a component other than the binder;
a molding step of molding the kneaded material obtained in the kneading step,
In the kneading step, the non-binder contains ammonium polyphosphate, polyhydric alcohol, and titanium oxide, and the binder is an ethylene copolymer resin, and based on 100 parts by mass of the binder, The non-binder is 230 parts by mass or more and 365 parts by mass or less, and the titanium oxide is 60 parts by mass or more and 95 parts by mass or less based on 100 parts by mass of the binder. A method for producing a fire-resistant resin molded article, wherein the ammonium polyphosphate is 120 parts by mass or more and 185 parts by mass or less, and the expansion ratio after heating at 800° C. for 2 hours is 5 to 12 times.

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