JPH09176404A - Fire-resistant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fire-resistant resin compsn. which has flame retardance, leaves behind, when burned, residues capable of retaining the shape, and hence exhibits a marked fire resistance. SOLUTION: A fire-resistant resin compsn. is prepd. by compounding an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10-50wt.% with a phosphorus compd., a neutralized thermally expandable graphite, and an inorg. filler in an amt. of the sum of the phosphorus compd. and the graphite of 20-200wt.% of the copolymer, in an amt. of the filler of 50-500wt.% of the copolymer, and in a wt. ratio of the phosphorus compd. to the graphite of (9:1)-(1:9).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fire resistant resin composition.

[0002]

2. Description of the Related Art In the field of building materials, conventionally,
Fire resistance is important. In recent years, resin materials have been widely used as building materials with the expansion of applications of the resin materials, and resin materials having fire resistance have been demanded.

For such fire resistance, not only the material itself is not easily burned, but also a property that the flame is not turned to the back side is required. Since the resin component and the organic component essentially have the property of burning or melting, there are problems such as how long such a state does not occur, and how long the contained inorganic component does not fall off.

Japanese Unexamined Patent Publication (Kokai) No. 6-55476 discloses a technique for forming a flame-retardant resin composition by using red phosphorus or a phosphorus compound and thermally expandable graphite in a polyolefin resin. Although this product has sufficient flame retardancy, for example, when it is used in the form of a sheet as a wall lining material, only fragile ash remains in the fireproof and fireproof tests, and the residue may fall off or There is a problem that the temperature rises to 260 ° C. or higher.

[0005]

SUMMARY OF THE INVENTION In view of the above, the present invention is a fire-resistant resin that exhibits flame-retardant properties, and that the residue after burning has a sufficient shape-retaining ability, thereby exhibiting remarkable fire-resistant performance. It is intended to provide a composition.

[0006]

Means for Solving the Problems The gist of the present invention is to construct a refractory resin composition by adding an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 50% by weight to a phosphorus compound, Neutralized thermally expandable graphite, and, containing an inorganic filler, the content of each,
The total amount of the phosphorus compound and the neutralized thermally expandable graphite is 20 to 200 parts by weight, the inorganic filler is 50 to 500 parts by weight, and the neutralization is performed with respect to 100 parts by weight of the ethylene-vinyl acetate copolymer. It is assumed that the treated heat-expandable graphite: phosphorus compound weight ratio is 9: 1 to 1: 9. Hereinafter, the present invention will be described in detail.

The refractory resin composition of the present invention comprises ethylene-
The vinyl acetate copolymer contains a phosphorus compound, neutralized heat-expandable graphite, and an inorganic filler. As the ethylene-vinyl acetate copolymer, those obtained by a conventionally known method can be used. The above ethylene-
The vinyl acetate copolymer is limited to those in which the amount of vinyl acetate contained in the copolymer is 10 to 50% by weight. If it is less than 10% by weight, it becomes too brittle when molded, and if it exceeds 50% by weight, free acetic acid is generated during heat molding.

In addition to the above ethylene-vinyl acetate copolymer, other resin can be added to the refractory resin composition of the present invention as a resin component. As the other resin, for example, another polyolefin resin is preferable, and among them, a polyethylene resin is preferable. Examples of the polyethylene-based resin include ethylene homopolymers, copolymers containing ethylene as a main component, mixtures thereof, and ethylene-ethylene acrylate copolymers. Examples of the copolymer containing ethylene as a main component include, for example,
Examples of the α-olefin include ethylene-α-olefin copolymers containing an ethylene part as a main component. Examples of the α-olefin include 1-hexene, 4-methyl-1-pentene, 1-octene, 1-butene, and 1-pentene. Etc.

The ethylene-vinyl acetate copolymer used in the present invention contains a phosphorus compound, neutralized thermally expansive graphite, and an inorganic filler. The fire resistance performance of the fire resistant resin composition of the present invention is expressed by these three components exhibiting their respective properties. Specifically, at the time of heating, the heat-expandable graphite forms an expanded heat-insulating layer to prevent the transfer of heat. Inorganic fillers then increase the heat capacity. The phosphorus compound has an ability to retain the shape of the expanded heat insulating layer and the filler.

The phosphorus compound is not particularly limited,
For example, red phosphorus; various phosphates such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylendiphenyl phosphate; phosphorus such as sodium phosphate, potassium phosphate, and magnesium phosphate Acid metal salts; ammonium polyphosphates; and compounds represented by the following general formula (1). Among them, ammonium polyphosphates; compounds represented by the following general formula (1) are preferable.

[0011]

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In the formula, R ¹ and R ³ are hydrogen and have 1 to 1 carbon atoms.
It represents a linear or branched alkyl group having 6 or 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, Represents an aryloxy group represented by Formulas 6 to 16.

As the above-mentioned red phosphorus, commercially available red phosphorus can be used, but from the viewpoints of moisture resistance and safety such as not spontaneously igniting during kneading, those obtained by coating the surface of red phosphorus particles with a resin are preferable. .

As the above-mentioned ammonium polyphosphates,
Examples thereof include ammonium polyphosphate, melamine-modified ammonium polyphosphate, and the like. Examples of commercially available ammonium polyphosphate include “AP4 manufactured by Hoechst Co.”
62 ”and“ Sumisafe P ”manufactured by Sumitomo Chemical Co., Ltd.

Examples of the compound represented by the above general formula (1) include methylphosphonic acid, dimethyl methylphosphonate, diethyl methylphosphonate, ethylphosphonic acid,
Propylphosphonic acid, butylphosphonic acid, 2-methylpropylphosphonic acid, t-butylphosphonic acid, 2,3-dimethyl-butylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, dioctylphenylphosphonate, dimethylphosphinic acid, methylethylphosphine Examples include acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, and bis (4-methoxyphenyl) phosphinic acid. The above phosphorus compounds may be used alone or in combination of two or more.

The thermally expandable graphite used in the present invention is a conventionally known substance, and powders of natural scaly graphite, pyrolytic graphite, Kish graphite and the like are mixed with inorganic acids such as concentrated sulfuric acid, nitric acid and selenic acid and concentrated nitric acid, A graphite intercalation compound is produced by treatment with a strong oxidizer such as perchloric acid, perchlorate, permanganate, dichromate, hydrogen peroxide, etc., while maintaining the carbon layer structure. Is a crystalline compound of.

In the present invention, 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. As the aliphatic lower amine, for example, monomethylamine, dimethylamine, trimethylamine,
Examples thereof include ethylamine, propylamine and butylamine. Examples of the alkali metal compound and alkaline earth metal compound include hydroxides, oxides, carbonates, sulfates, and organic acid salts of potassium, sodium, calcium, barium, magnesium and the like. Specific examples of the neutralized thermally expandable graphite include, for example, C
A-60S (made by Nippon Kasei) etc. are mentioned.

The particle size of the neutralized thermally expandable graphite used in the present invention is preferably 20 to 200 mesh. If the particle size is smaller than 200 mesh, the degree of expansion of graphite is small, the desired refractory insulation layer cannot be obtained, and if the particle size is larger than 20 mesh, there is an effect in that the degree of swelling is large, but when kneading with the resin, Poor dispersibility and inevitable deterioration of physical properties.

The inorganic filler used in the present invention is not particularly limited, and examples thereof include silica, diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, and ferrites.
Calcium hydroxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate, donnite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, calcium silicate, talc , Clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber,
Glass beads, silica-based balun, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balun, charcoal powder, various metal powders, potassium titanate, magnesium sulfate "MOS", lead zirconate titanate, Examples include aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, dehydrated sludge, and the like. Among them, it is preferable to use a water-containing inorganic substance such as calcium hydroxide, magnesium hydroxide, or aluminum hydroxide, which is dehydrated during heating and has an endothermic effect.

In the present invention, the total amount of the phosphorus compound and the neutralized heat-expandable graphite is 20 to 2 with respect to 100 parts by weight of the ethylene-vinyl acetate copolymer.
00 parts by weight, and 50 to 500 parts by weight of the inorganic filler. If the total amount of the phosphorus compound and the neutralized heat-expandable graphite is less than 20 parts by weight, sufficient fire resistance cannot be obtained. Since it cannot be used, it is limited to the above range. When the amount of the inorganic filler is less than 50 parts by weight,
If sufficient fire resistance is not obtained and exceeds 500 parts by weight,
It is limited to the above range since the mechanical properties are greatly reduced and cannot be used.

In the present invention, the neutralized thermal expansion graphite is combined with the phosphorus compound to prevent the expansive graphite from scattering during combustion and to maintain its shape. If too much graphite is used, expanded graphite will scatter during combustion, and a sufficient expanded heat insulating layer will not be obtained during heating. Conversely, if there are too many phosphorus compounds, the heat insulating layer will not be sufficient and the desired effect will be obtained. Since it disappears, the weight ratio of the neutralized heat-expandable graphite to the phosphorus compound is the neutralized heat-expandable graphite: phosphorus compound = 9: 1 to 1: 9. It is preferably 5: 1 to 1: 5, more preferably 3: 1 to 1: 3.

In the present invention, a phenol-based, amine-based, sulfur-based, etc. antioxidant, a metal damage inhibitor, an antistatic agent, a stabilizer, a cross-linking agent, a lubricant, A softening agent, a pigment, etc. may be added.

The refractory resin composition of the present invention can be obtained by kneading the above components using a kneading device such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader mixer or a roll.

[0024]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Ethylene-vinyl acetate copolymer (denoted as EVA1 in Table 1) (vinyl acetate content 28%, density = 0.95, M
I = 6.0), and neutralized thermal expansion graphite (CA-
60S, manufactured by Nippon Kasei Co., Ltd., ammonium polyphosphate (Sumisafe P, manufactured by Sumitomo Chemical Co., Ltd.), t-butylphosphonic acid (manufactured by Wako Pure Chemical Industries, Ltd.), aluminum hydroxide (B703S,
Made by Nippon Light Metal Co., Ltd., magnesium hydroxide (Kisuma 5B,
(Kyowa Chemical Co., Ltd.) was blended in the proportions shown in Table 1 to melt-knead each component using a roll to obtain a resin composition. The obtained resin composition was pressed at 140 ° C. to prepare a test piece used for fire resistance evaluation.

The fire resistance was evaluated by using a cone calorimeter (CONE2A, manufactured by Atlas Co., Ltd.), and the irradiation heat quantity 3
It was performed at 5 kW / m ² (horizontal direction). The evaluation method was to apply a heat amount of 30 minutes to a test piece (length 100 mm, width 100 mm, thickness 3.0 mm), and then, if the temperature of the back surface of the test piece (the heating surface was the front) was 260 ° C. or less, ○, Those having a temperature of over 260 ° C were marked with x. The results are shown in Table 1.

Examples 2 and 3 and Comparative Examples 1 to 3 The components were blended and blended in the amounts shown in Table 1, and each component was melt-kneaded using a roll to obtain a resin composition. A test piece was prepared from the obtained resin composition in the same manner as in Example 1, and the fire resistance was evaluated. The results are shown in Table 1.

In Table 1, EVA2 is vinyl acetate content 1
9%, density = 0.92, MI = 2.5 represents an ethylene-vinyl acetate copolymer, EVA3 is a vinyl acetate content 6%, density = 0.92, MI = 8.5 ethylene-acetic acid Represents a vinyl copolymer, LDPE has a density = 0.92,
It represents a low density polyethylene with MI = 7.0.

[0029]

[Table 1]

[0030]

EFFECTS OF THE INVENTION The fire resistant resin composition obtained by the present invention has a remarkable heat resistance by forming an expansion heat insulating layer upon heating and further maintaining its shape, and thus has a wide range of properties as a fire resistant building member. It can be provided for use.

Claims (1)

[Claims] 1. The content of vinyl acetate is 10 to 50% by weight.
To the ethylene-vinyl acetate copolymer, which is a phosphorus compound,
The heat-expandable graphite which has been neutralized and an inorganic filler are contained, and the content of each is neutralized with a phosphorus compound with respect to 100 parts by weight of the ethylene-vinyl acetate copolymer. The total amount of the thermally expandable graphite and the inorganic filler is 20 to 200 parts by weight, the inorganic filler is 50 to 500 parts by weight, and the weight ratio of the neutralized thermally expandable graphite: phosphorus compound is 9: 1 to 1: 9.
A fire-resistant resin composition, wherein