JP2003064209A - Foam material of epoxy resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a foam material of an epoxy resin having high flame retardancy or fire resistance. SOLUTION: The epoxy resin foam material is the one obtained by foaming a resin composition which contains an epoxy resin, a phosphorus compound, a neutralized thermal expansion graphite, an inorganic filler, and a foaming agent. The amounts of each component are, to 100 pts.wt. of the epoxy resin, 25-200 pts.wt. of the phosphorus composition, 10-150 pts.wt. of the neutralized thermal expansion graphite, 10-200 pts.wt. of the inorganic filler, and 2-50 pts.wt. of the foaming agent.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin foam, and more particularly to a highly flame-retardant and fire-resistant epoxy resin foam.

[0002]

2. Description of the Related Art Resin foams have excellent heat insulating properties and are used in a wide variety of applications such as building materials, transportation equipment such as automobiles, packaging materials, household products and the like. Such resin foams include, as thermoplastic resin foams, polyolefin-based resin foams and polystyrene-based resin foams, and as thermosetting resin foams, polyurethane resin foams, phenolic resin foams, A urea resin foam, an epoxy resin foam, etc. are generally used. Among them, epoxy resins are excellent in adhesiveness, chemical resistance, heat resistance, dimensional stability, mechanical strength, and electrical insulation, and various epoxy resin foams have been proposed.

For example, JP-A-1-197553 discloses a foaming epoxy resin composition comprising an epoxy resin, an amine type curing agent, a curing accelerator and an inorganic filler. Such an epoxy resin foam is used as a joint material, a sealing material, a caulking material or the like because of its characteristics. However, when it is used as a building material such as metal siding and heat insulation material for inner and outer wall pipes,
It is desired to have flame retardancy and further fire resistance.

As an epoxy resin foam having flame retardancy, JP-A-9-227709 discloses an epoxy resin foam which comprises an epoxy resin, phosphoric acid, a foaming agent and a foam stabilizer. However, this foam
Foaming utilizing reaction heat when reacting an epoxy resin and phosphoric acid, since phosphoric acid is incorporated into the resin skeleton at the same time as curing and flame retardancy is imparted, the amount of phosphoric acid taken in is limited, As a result, the flame retardancy was not sufficient.

[0005]

In view of the above problems, an object of the present invention is to provide an epoxy resin foam having high flame retardancy or fire resistance.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that a phosphorus compound, a specific thermally expansive graphite, an inorganic filler and a foaming agent in an epoxy resin in a specific amount. The inventors have found that an epoxy resin foam obtained by foaming the compounded resin composition has excellent flame retardancy and fire resistance, and completed the present invention.

That is, according to the first aspect of the present invention, the epoxy resin, the phosphorus compound, the neutralized heat-expandable graphite, the inorganic filler, and the foaming agent are contained, and the respective contents are epoxy resin. 25 to 200 parts by weight of a phosphorus compound, 10 to 150 parts by weight of neutralized thermally expandable graphite, 10 to 200 parts by weight of an inorganic filler, and 2 to 50 parts by weight of a foaming agent with respect to 100 parts by weight. Parts, the resin composition having a total of 50 to 500 parts by weight of the phosphorus compound, the neutralized thermally expandable graphite, the inorganic filler, and the foaming agent is foamed. Foaming is provided.

According to the second aspect of the present invention, the weight ratio of the phosphorus compound to the neutralized thermally expandable graphite is 1
There is provided the epoxy resin foam according to the first invention, which is 0: 1 to 1:10.

According to the third aspect of the present invention, the phosphorus compound is at least one selected from red phosphorus, ammonium polyphosphate, melamine-modified ammonium polyphosphate, and a compound represented by the following general formula (1). There is provided the epoxy resin foam according to the first or second invention, which is a phosphorus compound.

[0010]

[Chemical 2] (In the formula, R ¹ and R ³ represent hydrogen, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R ² represents a hydroxyl group or a carbon number. A linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms, and 6 to 1 carbon atoms
It represents an aryl group having 6 or an aryloxy group having 6 to 16 carbon atoms. )

According to a fourth aspect of the present invention, the epoxy resin according to any one of the first to third aspects is characterized in that the inorganic filler is a hydrated inorganic substance and / or a metal carbonate. A foam is provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The constituents of the resin composition of the epoxy resin foam of the present invention, the manufacturing method, and the like will be described in detail below.

The epoxy resin used in the present invention is not particularly limited, but it is basically obtained by reacting a monomer having an epoxy group with a curing agent.

As the above-mentioned monomer having an epoxy group,
Examples thereof include bifunctional glycidyl ether type, glycidyl ester type, and polyfunctional glycidyl ether type.

Examples of the bifunctional glycidyl ether type monomers include polyethylene glycol type, polypropylene glycol type, neopentyl glycol type, 1,6-hexanediol type, trimethylolpropane type, bisphenol A type, bisphenol F type. , Propylene oxide-bisphenol A type, hydrogenated bisphenol A type, and the like.

Examples of the glycidyl ester type monomer include hexahydrophthalic anhydride type, tetrahydrophthalic anhydride type, dimer acid type and p-oxybenzoic acid type monomers.

Examples of the polyfunctional glycidyl ether type monomers include phenol novolac type monomers, orthocresol novolac type monomers, DPP novolac type monomers, dicyclopentadiene / phenol type monomers and the like.

The above-mentioned monomer having an epoxy group may be used alone or in combination of two or more kinds.

Examples of the curing agent include polyaddition type and catalyst type.

Examples of polyaddition type curing agents include amines, acid anhydrides, polyphenols and polymercaptans. Examples of the catalyst type curing agent include tertiary amines, imidazoles, Lewis acids and Lewis bases.

Further, other resin may be added to the epoxy resin. Since the effect of the epoxy resin is not exhibited when the addition amount of the other resin increases, the addition amount of the other resin to the epoxy resin 1 is preferably 5 (weight ratio) or less.

The method for curing the epoxy resin is not particularly limited, and any known method can be used.

The phosphorus compound used in the present invention is not particularly limited, and examples thereof include red phosphorus; various phosphorus such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate. Acid esters; metal phosphates such as sodium phosphate, potassium phosphate and magnesium phosphate; ammonium polyphosphates; compounds represented by the following general formula (1) and the like. Among these, red phosphorus, ammonium polyphosphates, and compounds represented by the following general formula (1) are preferable from the viewpoint of flame retardancy and fire resistance, and polyphosphorus is preferable from the viewpoints of performance, safety, cost and the like. Ammonium acid salts are more preferred.

[0024]

[Chemical 3]

In the formula (1), R ¹ and R ³ are hydrogen, a linear or branched alkyl group having 1 to 16 carbon atoms, or
It represents an aryl group having 6 to 16 carbon atoms. R ² is a hydroxyl group,
A linear or branched alkyl group having 1 to 16 carbon atoms,
A linear or branched alkoxyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, or 6 to 1 carbon atoms
6 represents an aryloxy group.

The above red phosphorus improves the flame retardant effect even if added in a small amount. As the above-mentioned red phosphorus, commercially available red phosphorus can be used, but from the viewpoint of moisture resistance and safety such as not spontaneously igniting at the time of kneading, red phosphorus particles whose surface is coated with a resin are preferably used. .

As the above-mentioned ammonium polyphosphates,
It is not particularly limited, and examples thereof include ammonium polyphosphate, melamine-modified ammonium polyphosphate, and the like.
Ammonium polyphosphate is preferably used from the viewpoint of handleability and the like. Examples of commercially available products include “AP422” and “AP462” manufactured by Clariant, and “Sumisafe P” manufactured by Sumitomo Chemical Co., Ltd.

The compound represented by the general formula (1) is not particularly limited, and examples thereof include methylphosphonic acid, dimethyl methylphosphonate, diethyl methylphosphonate, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid and 2-methyl. Propylphosphonic acid, t-butylphosphonic acid, 2,3-dimethyl-butylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, dioctylphenylphosphonate, dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, Dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, bis (4-methoxyphenyl) phosphinic acid and the like can be mentioned. Among them, t-butylphosphonic acid is
Although expensive, it is preferable in terms of high flame retardancy. The above phosphorus compounds may be used alone or in combination of two or more.

The neutralized heat-expandable graphite used in the present invention is obtained by neutralizing heat-expandable graphite which is a conventionally known substance. The heat-expandable graphite is a powder of natural scaly graphite, pyrolytic graphite, quiche graphite or the like, concentrated sulfuric acid, nitric acid, an inorganic acid such as selenate, concentrated nitric acid, perchloric acid, perchlorate, permanganate. It is a graphite intercalation compound produced by treatment with a strong oxidant such as salt, dichromate or hydrogen peroxide, and is a crystalline compound while maintaining the layered structure of carbon.

The heat-expandable graphite obtained by the acid treatment as described above is further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound or the like to be the above-mentioned neutralization treatment. A thermally expansive graphite is obtained.

The aliphatic lower amine is not particularly limited, and examples thereof include monomethylamine, dimethylamine,
Examples include trimethylamine, ethylamine, propylamine, butylamine and the like.

The above-mentioned alkali metal compound and alkaline earth metal compound are not particularly limited, and examples thereof include hydroxides, oxides, carbonates, sulfates and organic acid salts of potassium, sodium, calcium, barium, magnesium and the like. And so on.

The particle size of the above-mentioned neutralized thermally expandable graphite is preferably 20 to 200 mesh. Grain size is 200
If it is smaller than the mesh, the degree of expansion of graphite is small and a predetermined refractory heat insulation layer cannot be obtained, and if it is larger than 20 mesh, the degree of expansion of graphite is large, but it is dispersed when kneading with the resin component. Inferiority is inevitable and deterioration of physical properties is unavoidable.

Commercially available products of the above-mentioned neutralized thermally expandable graphite are, for example, "Frame Cut GRE" manufactured by Tosoh Corporation.
P-EG ", UCAR Carbon's" GRAFG "
urad ”and the like.

The inorganic filler used in the present invention includes:
Not particularly limited, for example, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, Calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, strontium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite , Sericite, glass fiber, glass beads, silica balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, charcoal powder, various metal powders, potassium titanate Arm, magnesium sulfate, "MOS"
(Trade name), lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless fiber,
Examples thereof include zinc borate, various magnetic powders, slag fibers, fly ash, and dehydrated sludge. Of these, hydrous inorganic substances and metal carbonates are preferable.

Water-containing inorganic substances such as magnesium hydroxide and aluminum hydroxide are particularly preferable in that endothermic reaction occurs due to water produced by the dehydration reaction during heating, a temperature rise is reduced and high heat resistance is obtained. Further, since magnesium hydroxide and aluminum hydroxide have different temperature ranges in which the dehydration effect is exerted, when used in combination, the temperature range in which the dehydration effect is exerted is expanded, and a more effective temperature rise suppressing effect is obtained, so they are used in combination. It is preferable.

The above metal carbonate is considered to promote swelling by the reaction with the above phosphorus compound. Particularly, as the phosphorus compound,
A high flame retardant effect is obtained when ammonium polyphosphate is used.

Among the above metal carbonates, alkali metal carbonates such as sodium carbonate; alkaline earth metal carbonates such as magnesium carbonate, calcium carbonate and strontium carbonate; zinc carbonate, etc., group IIb of the periodic table. Metal carbonates are preferred.

The particle size of the inorganic filler is 0.5 to
400 μm is preferable, and more preferably about 1 to 100 μm.
m. The above inorganic filler, when the addition amount is small,
Since the dispersibility greatly affects the performance, it is desirable that the particle size is small, but if it is less than 0.5 μm, secondary aggregation occurs and the dispersibility deteriorates. When the addition amount of the inorganic filler is large,
As the filling rate increases, the viscosity of the resin composition increases and the moldability decreases, but the viscosity of the resin composition can be decreased by increasing the particle size, so that the particle size is preferably large. If the particle size exceeds 400 μm, the surface properties of the molded product and the mechanical properties of the resin composition deteriorate.

As the above-mentioned inorganic filler, for example, for aluminum hydroxide, "H-42M" (manufactured by Showa Denko KK) having a particle size of 1 µm, "H-31" (manufactured by Showa Denko KK) having a particle size of 18 µm, and , "Whiten SB Red" (made by Bihoku Powder Co., Ltd.) having a particle size of 1.8 μm, and “BF300” (made by Bihoku Powder Co., Ltd.) having a particle size of 8 μm.

The above inorganic fillers may be used alone or in combination of two or more kinds. In addition, it is more preferable to use a combination of an inorganic filler having a large particle size and an inorganic filler having a small particle size, and by using the combination, it is possible to achieve high filling while maintaining the mechanical performance of the resin foam. Becomes

The foaming agent used in the present invention may be any as long as it shows a decomposition temperature lower than the expansion temperature of the above-mentioned thermally expandable graphite and generates a gas when heated to a temperature higher than the decomposition temperature, for example, azo. Organic blowing agents such as dicarbonamide, N, N-dinitrosopentamethylenetetramine, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide and 4,4-oxybis (benzenesulfonyl hydrazide), inorganic blowing agents such as sodium bicarbonate and ammonium carbonate Is mentioned.

In the resin composition for an epoxy resin foam of the present invention, the compounding amount of each component is the epoxy resin 10
25 to 200 parts by weight of the phosphorus compound with respect to 0 parts by weight,
10 to 150 parts by weight of the neutralized thermally expandable graphite, 10 to 200 parts by weight of the inorganic filler, and 2 to 50 parts of the foaming agent.
Parts by weight.

When the amount of the above phosphorus compound is less than 25 parts by weight, sufficient flame retardancy and fire resistance cannot be obtained, and when it exceeds 200 parts by weight, mechanical properties are largely deteriorated and use cannot be endured.

When the content of the above-mentioned neutralized thermally expandable graphite is less than 10 parts by weight, sufficient flame retardancy and fire resistance cannot be obtained, and when it exceeds 150 parts by weight, mechanical properties are deteriorated. Is too large to be used.

If the amount of the above-mentioned inorganic filler is less than 10 parts by weight, sufficient flame retardancy and fire resistance cannot be obtained, and if it exceeds 200 parts by weight, the mechanical properties are largely deteriorated and it can withstand use. Disappear.

The foaming ratio of the above-mentioned foaming agent varies depending on the required performance based on the use of the foam, but if it is less than 2 parts by weight, sufficient foaming cannot be performed, and if it exceeds 50 parts by weight, a foam is obtained. Becomes difficult.

Further, the total amount of the phosphorus compound, the neutralized heat-expandable graphite, the inorganic filler and the foaming agent is 50 to 500 parts by weight with respect to 100 parts by weight of the epoxy resin. When the total amount of the phosphorus compound, the neutralized thermally expandable graphite, the inorganic filler and the foaming agent is less than 50 parts by weight, sufficient flame retardancy and fire resistance cannot be obtained, and when it exceeds 500 parts by weight. The mechanical properties are greatly deteriorated and it cannot be used.

In particular, in the resin composition for an epoxy resin foam of the present invention, the neutralized heat-expandable graphite and the phosphorus compound are combined so that the shape during combustion is maintained and the heat during combustion is maintained. Suppressing the expansion of expansive graphite, flame resistance,
It is possible to improve fire resistance. The weight ratio of the neutralized thermally expandable graphite to the phosphorus compound is 10: 1 to 1: 1.
0 is preferable, and 5: 1 to 1: 5 is more preferable.
If the amount of the heat-expandable graphite that has been neutralized is too large, the expanded graphite is scattered during combustion and the expanded heat insulating layer is not formed. On the other hand, if the phosphorus compound is too much, sufficient flame retardancy during heating,
Fire resistance is not demonstrated. When the content is within the above range, it can be used in an application form having a large shape retention property.

The resin composition of the present invention contains a phenol-based, amine-based, sulfur-based, etc. antioxidant, a metal-damage-preventing agent, an antistatic agent, a stabilizer, a cross-linking agent, and a lubricant as long as the physical properties thereof are not impaired. , A softening agent, a pigment, a tackifying resin and the like may be added.

The epoxy resin foam of the present invention can be obtained by subjecting the above resin composition to molding and foaming. That is, using a known device such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader mixer, a twin roll, a planetary stirrer, etc., the above components do not completely crosslink the epoxy resin, and a foaming agent. After kneading at a temperature below which does not decompose, is subsequently formed into an appropriate shape, for example, a sheet shape. Examples of the molding method include conventionally known molding methods such as press molding, extrusion molding, injection molding and coater molding. During molding, the epoxy resin and the curing agent react with each other by heating until they are not deformed and cross-linked, and then by heating above the temperature at which the foaming agent foams, a resin foam is obtained. The foaming may be carried out by heating with hot air, infrared rays, a metal bath, an oil bath, etc., and the molding and foaming steps may be carried out continuously or in a batch manner. During the cross-linking and foaming process, the degree of cross-linking depends on the required quality of the resin foam application,
The degree of foaming ratio can be adjusted.

The epoxy resin foam of the present invention has flame retardancy and fire resistance because the epoxy resin, phosphorus compound, neutralized thermally expansive graphite, and inorganic filler exhibit their respective performances. Exert. Specifically, the thermally expansive graphite expands during combustion and the presence of a phosphorus compound forms a strong expansive heat-insulating layer that suppresses radiant heat from the fire source and diffusion of thermally decomposed products of the foam. And exhibits flame resistance and fire resistance. At that time, because epoxy resin is used,
The resin component also forms a char (carbonized) layer and contributes as an expansive heat insulating layer. In addition, the inorganic filler has an effect of increasing the heat capacity at that time, and in particular, the water-containing inorganic substance generates cooling water at the time of combustion and suppresses the temperature rise, and thus exhibits a flame retardant / fireproof effect. Furthermore, the metal carbonate reacts with the phosphorus compound to make the expansion heat insulating layer stronger, so that flame retardancy and
Improve the fire resistance effect.

[0053]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples. The performance evaluation method in the examples is as follows.

(1) Flame retardancy: The oxygen index of the resin foam was measured according to JIS K7201. (2) Foaming state: The cross section and the longitudinal section of the resin foam are randomly measured in each of 5 fields of view, and the appearance of the sheet is adversely affected depending on whether or not the diameter of the bubbles is fine and uniform. The presence or absence was visually observed, and when the result was good, the result was ◯, and when the result was poor, the result was x. (3) Appearance: The surface smoothness, discoloration, etc. of the resin foam were visually observed comprehensively. (4) Fire resistance: The foam was placed on a hot plate heated to 500 ° C., the back surface temperature when heated for 60 minutes was measured, and when the back surface temperature did not exceed 260 ° C., 26
When the temperature exceeded 0 ° C, it was marked with x.

Example 1 40 parts by weight of a bisphenol F type epoxy monomer ("Epicoat 807" manufactured by Japan Epoxy Resins), 60 parts by weight of a diamine-based curing agent ("Epicure FL052" manufactured by Japan Epoxy Resins), ammonium polyphosphate (Hoechst) 100 parts by weight of "AP-422" manufactured by the same company, and neutralized heat-expandable graphite ("GREP-E" manufactured by Tosoh Corporation).
G ") 50 parts by weight, aluminum hydroxide (Showa Denko KK" H-31 ") 100 parts by weight, and azodicarbonamide (Eiwa Chemical Co., Ltd." Vinihol FZ # 80 ") 5 parts by weight are kneaded by a kneading roll, An epoxy resin composition was prepared.
The obtained resin composition is formed into a sheet with a heating press, and then heated with a press at 80 ° C. for 15 minutes to have a thickness of 2.5 m.
m sheets were obtained. The produced sheet was heated and foamed in an oven at 160 ° C. to obtain an epoxy resin foam. The results of performance evaluation of the obtained foam are shown in Table 1.

Example 2 100 parts by weight of bisphenol F type epoxy monomer (“Epicoat 807” manufactured by Japan Epoxy Resins Co., Ltd.), 17 parts by weight of hexamethylenediamine (manufactured by Wako Pure Chemical Industries, Ltd.), t
-Butylphosphonic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 30 parts by weight, neutralized thermally expandable graphite (manufactured by Tosoh Corporation "GREP-E"
G ”) 50 parts by weight, calcium carbonate (Bihoku Kouka Co., Ltd.,“ Whiteon BF-300 ”) 50 parts by weight, 4,4′-oxybis (benzenesulfonyl hydrazide (Eiwa Chemical Co., Ltd.“ Neocerbon N # 1000S ”) 10 parts by weight. 2. The parts were kneaded with a planetary stirrer to prepare an epoxy resin composition, and the obtained resin composition was sheet-molded by a hot press and then heated at 60 ° C. for 10 minutes to give a thickness of 2. 5m
m sheets were obtained. The produced sheet was heated and foamed in an oven at 160 ° C. to obtain an epoxy resin foam. The results of performance evaluation of the obtained foam are shown in Table 1.

Example 3 45 parts by weight of urethane-modified bisphenol A type epoxy monomer (“E292” manufactured by Japan Epoxy Resins Co., Ltd.),
55 parts by weight of a diamine-based curing agent (“Epicure FL052” manufactured by Japan Epoxy Resins Co., Ltd.), 50 parts by weight of red phosphorus (“EXOLIT PR602” manufactured by Hoechst Co., Ltd.), and neutralized heat-expandable graphite (“GREP- manufactured by Tosoh Corporation” E
G ”) 80 parts by weight, magnesium hydroxide (Kyowa Chemical Co., Ltd.“ Kisuma 5A ”) 70 parts by weight, strontium carbonate (Sakai Chemical Co., Ltd.) 50 parts by weight, sodium hydrogen carbonate (Nagawa Kasei“ Cerbon SCP ”) 20 parts by weight The parts were kneaded with a kneading roll to prepare an epoxy resin composition. The obtained resin composition is formed into a sheet by roll coating, and then 100
The sheet was heated at 5 ° C for 5 minutes to obtain a sheet having a thickness of 2.5 mm. The produced sheet was heated and foamed in an oven at 180 ° C. to obtain an epoxy resin foam. The results of performance evaluation of the obtained foam are shown in Table 1.

[0058]

[Table 1]

[0059]

EFFECT OF THE INVENTION The epoxy resin foam of the present invention is used in a wide range of applications such as building materials because it has the above-mentioned constitution and forms an expansion heat insulating layer at the time of heating to exhibit high flame retardancy and fire resistance. It is possible.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 63/00 C08L 63/00 CF term (reference) 4F074 AA64 AC04 AC31 AD16 BA13 CA29 4J002 CD011 CD051 DA027 DA056 DE208 DE219 DH056 EP018 ES008 EV298 EW126 FD019 FD136 FD328

Claims (4)

[Claims] 1. An epoxy resin, a phosphorus compound, a neutralized thermally expandable graphite, an inorganic filler, and a foaming agent,
The content of each is 25 to 200 parts by weight of the phosphorus compound, 10 to 150 parts by weight of the neutralized thermal expansive graphite, and 10 parts by weight of the inorganic filler with respect to 100 parts by weight of the epoxy resin.
~ 200 parts by weight and 2 to 50 parts by weight of the foaming agent,
An epoxy resin foam, which is obtained by foaming a resin composition in which the total amount of the phosphorus compound, the neutralized thermally expansive graphite, the inorganic filler, and the foaming agent is 50 to 500 parts by weight. 2. The epoxy resin foam according to claim 1, wherein the weight ratio of the phosphorus compound and the neutralized thermally expandable graphite is 10: 1 to 1:10. 3. The phosphorus compound is at least one phosphorus compound selected from red phosphorus, ammonium polyphosphate, melamine-modified ammonium polyphosphate, and a compound represented by the following general formula (1). The epoxy resin foam according to 1 or 2. [Chemical 1] (In the formula, R ¹ and R ³ represent hydrogen, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R ² represents a hydroxyl group or a carbon number. A linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms, and 6 to 1 carbon atoms
It represents an aryl group having 6 or an aryloxy group having 6 to 16 carbon atoms. ) 4. The epoxy resin foam according to claim 1, wherein the inorganic filler is a hydrous inorganic substance and / or a metal carbonate.