JPH09296119A - Flame-retardant engineering plastic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition free from halogen, having high flame-retardancy and low smoking tendency and generating no corrosive gas by compounding an engineering plastic with a heat-expandable graphite and red phosphorus and/or a phosphorus compound. SOLUTION: This composition is produced by compounding (A) 100 pts.wt. of an engineering plastic (e.g. a polyester resin or a polyamide resin) with (B) 1-30 pts.wt. of heat-expandable graphite and (C) 1-30 pts.wt. of red phosphorus and/or (D) 1-30 pts.wt. of a phosphorus compound (preferably an ammonium polyphosphate). The component B is preferably a heat-expandable graphite exhibiting a specific volume difference of >=100mL/g before and after the quick heating from room temperature to 800-1000 deg.C and having a particle size distribution containing 20-1wt.% of fraction passing through a 80 mesh sieve. The component B can be produced e.g. by the oxidation treatment of natural graphite, The component C is preferably surface-treated with a phenolic resin, aluminum hydroxide, etc., from the viewpoint of safety.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant engineering plastic material having excellent flame-retardant performance and suppressing generation of smoke and corrosive gas during combustion.

[0002]

2. Description of the Related Art Engineering plastic materials such as enclosures and internal parts for electric / electronic / OA equipment, vehicle interior materials, building materials, etc. are preferably flame-retarded in order to suppress the risk of fire and fire spread, or , Many are obligatory. To make resin materials flame-retardant,
Flame retardants such as halogen-based flame retardants, magnesium hydroxide, aluminum hydroxide, red phosphorus, and phosphorus compounds have been proposed.
However, these also have the following problems,
It is not always perfect.

For example, halogen-based flame retardants are highly flame-retardant (for example, UL 94V-0, V-1, V with a small amount of compound).
-2 etc.) can be achieved, but soot and smoke are often generated. Also,
When the resin composition is processed or heated during a fire, some acidic substances such as hydrogen halide are generated.Therefore, there is concern that the processing equipment may be corroded and that human or surrounding equipment may be adversely affected at the fire site. It

Further, metal hydroxides such as magnesium hydroxide and aluminum hydroxide do not cause smoke generation or corrosive gas generation, but require a large amount of compounding. Therefore, mechanical strength and lightness, which are excellent characteristics of the resin, are significantly impaired.

Further, phosphorus-based flame retardants, such as red phosphorus and phosphoric acid ester, show excellent flame retardancy with respect to engineering plastics such as polyamide, polyester and polycarbonate, but generate a lot of smoke.

[0006]

Under such circumstances, there is a demand for an engineering plastic which does not contain halogen, has a low smoke emission, is less likely to generate corrosive gas, and is effective in a small amount. Nitrogen-containing flame retardants such as melamine and cyanuric acid have been proposed as candidates. For example, Japanese Patent Laid-Open No. 51-54655 discloses that high flame retardancy is achieved by blending a small amount of melamine cyanurate with a polyamide resin.
Further, JP-A-52-108452 discloses that high flame retardancy is achieved by blending a polyester resin with a condensate of a thiophosphoric acid derivative and thiourea and melamine. However, these produced bleed-out on the resin surface and generated corrosive gas, and generated a large amount of smoke.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest researches in view of such a situation, and as a result, in an engineering plastic composition, heat-expandable graphite having a specific expansivity and a specific particle size distribution. And that by adding red phosphorus and / or a phosphorus-based compound, a remarkable flame retardant effect, low smoke emission and low corrosiveness are exhibited, and that a specific phosphorus-based compound has a synergistic effect on the heat-expandable graphite. Heading out, the present invention has been completed.

That is, the present invention is based on (A) 100 parts by weight of engineering plastic, (B) 1 to 30 parts by weight of heat-expandable graphite, (C) 1 to 30 parts by weight of red phosphorus, and / or (D) phosphorus. A flame-retardant engineering plastic composition containing 1 to 30 parts by weight of a compound.

Hereinafter, the present invention will be described in more detail.

The component A in the present invention is an engineering plastic, and examples thereof include polyester resin, polyamide resin, polycarbonate resin, modified polyphenylene oxide resin and the like.

The present invention is not limited to the case where the above-mentioned engineering plastics are used alone, and may be a mixture of two or more kinds, or a polymer other than these, depending on the required physical properties of the resin. .

The polyester resin as used in the present invention means a polymer material obtained by polycondensation of a polybasic acid and a polyhydric alcohol, and examples thereof include polybutylene terephthalate resin and polyethylene terephthalate resin.

The polyamide resin as referred to in the present invention means a linear polymer material having an amide group in the molecule, for example, nylon 6, nylon 66, nylon 11, nylon 1
2, nylon 46 and the like.

The polycarbonate resin referred to in the present invention means
It refers to a polymer material having a carbonate group (-O-CO-O-) in the molecule. Polycarbonate can be produced, for example, by polycondensation of diol and phosgene or polycondensation of diol and dialkyl carbonate or diaryl carbonate. As the diol, either an aliphatic type or an aromatic type is used as a monomer. As the aromatic diol, 2,2-bis (4-hydroxyphenyl) propane (so-called bisphenol A), bis (4-hydroxyphenyl) sulfone (so-called bisphenol S),
Examples include bis (4-hydroxyphenyl) methane (so-called bisphenol F).

The modified polyphenylene oxide resin as used in the present invention means a polymer alloy of polyphenylene oxide and another thermoplastic or thermosetting resin. Examples of polyphenylene oxide include poly (oxy-2,6-dimethyl-1,4-phenylene). Examples of the thermoplastic resin as the modifier include polystyrene, acrylonitonyl-butadiene-styrene terpolymer, polyamide and the like. As polystyrene, elastomer-modified polystyrene (so-called impact-resistant polystyrene) is exemplified as a suitable modifier for polyphenylene oxide.

The component B in the present invention is heat-expandable graphite. The heat-expandable graphite is a substance derived from natural graphite or artificial graphite, which has the property of expanding in the c-axis direction of the crystal by rapid heating from room temperature to 800 to 1000 ° C., and from room temperature to 800 to 1000 ° C. The difference in specific volume before and after rapid heating to 100 ml / g or more. This is 10
100ml is the one that does not have swelling of 0ml / g or more.
This is because the flame retardancy is remarkably smaller than that of a material having an expansivity of / g or more. The expansivity referred to in the present invention means the difference between the specific volume after heating, ml / g, and the specific volume at room temperature.

A method for measuring the expansivity will be specifically described. Add 2 g of heat-expandable graphite in a quartz beaker preheated to 1000 ° C in an electric furnace, and quickly put the quartz beaker in an electric furnace heated to 1000 ° C for 10 seconds, and then calculate the weight of 100 ml of the expanded graphite. , Apparent apparent specific gravity g / m
l was measured and defined as specific volume = 1 / loosening apparent specific gravity. Next, the specific volume of the heat-expandable graphite at room temperature which was not heated was determined by the same method, and the expansivity of the heat-expandable graphite was determined as the expansivity = specific volume after heating−specific volume at room temperature. .

When the heat-expandable graphite of the present invention was observed with an electron microscope before and after expansion, almost no expansion was observed in the a-axis direction and the b-axis direction, and expansion was observed only in the c-axis direction.

The method for producing the heat-expandable graphite of the present invention is not particularly limited, but it can be obtained by, for example, oxidizing natural graphite or artificial graphite. Examples of the oxidation treatment include electrolytic oxidation in sulfuric acid, treatment with an oxidizing agent such as phosphoric acid and nitric acid, sulfuric acid and nitric acid, and hydrogen peroxide, but the production method of the heat-expandable graphite is not limited in the present invention.

The particle size of the heat-expandable graphite of the present invention affects the flame retardant effect. A preferable particle size distribution is 20% by weight or less, more preferably 20 to 1% by weight, having a particle size of 80 mesh. If the particle size of the particles passing through the 80 mesh screen is larger than 20% by weight, the flame retardant effect is insufficient. When the particle size of the particles passing through a 80-mesh screen is less than 1% by weight, the shape retention performance of the resin when exposed to fire may be slightly deteriorated.

The heat-expandable graphite preferably has a particle size larger than a certain level as described above. However, in order to suppress the deterioration of the physical properties of the engineering plastic composition due to the incorporation of large particles, the surface of the heat-expandable graphite is covered with silane. Surface treatment with a coupling agent or a titanate coupling agent is also preferable.

Since the heat-expandable graphite is produced by the oxidation treatment in sulfuric acid as described above, it may be slightly acidic depending on the production conditions. In that case, by making an alkaline substance such as magnesium hydroxide coexist,
It is possible to suppress equipment corrosion during manufacturing and processing of engineering plastic compositions. These alkaline substances are preferably in the vicinity of the heat-expandable graphite, and therefore it is preferable that these alkaline substances be premixed with the heat-expandable graphite to be attached to the surface of the particles of the heat-expandable graphite. It is sufficient that the amount of the alkaline substance compounded is less than 10% by weight based on the heat-expandable graphite.

The C component in the present invention is red phosphorus.

The surface of the red phosphorus is selected from the group consisting of thermosetting resins and inorganic compounds from the viewpoint of handling safety.
Those surface-treated with one or more compounds are particularly preferable. The thermosetting resin is not particularly limited, but preferable examples thereof include phenol resin and melamine resin. The inorganic compound is not particularly limited, but hydroxides or oxides of magnesium, aluminum, nickel, iron, cobalt and the like are preferable.

The amount of red phosphorus to be used is 1 to 30 parts by weight with respect to 100 parts by weight of engineering plastic. If it is less than 1 part by weight, the flame retardant effect is insufficient, while if it exceeds 30 parts by weight, the increase in the flame retardant effect is small.

The component D in the present invention is a phosphorus compound.

The phosphorus compound is not particularly limited as long as it has the synergistic effect of the heat-expandable graphite and the effect of suppressing smoke generation, but the oxo acid of phosphorus (hereinafter abbreviated as “phosphoric acid”). ) Ester, phosphate, phosphate salt,
A condensed phosphate is illustrated. Among them, those containing nitrogen have high flame retardancy. Specifically, ammonium polyphosphate,
Nitrogen-containing phosphates such as melamine-modified ammonium polyphosphate, melamine polyphosphate, and melamine phosphate are listed, and ammonium polyphosphate is most preferable because it has a high phosphorus content. Particularly in applications where water resistance is required, it is preferable to use ammonium polyphosphate whose surface is coated with a resin such as melamine resin, urea resin or phenol resin.

The amount of the phosphorus compound used is 1 to 30 parts by weight based on 100 parts by weight of the engineering plastic. If it is less than 1 part by weight, the flame retardant effect is insufficient, while if it exceeds 30 parts by weight, the increase in the flame retardant effect is small.

Other flame retardants may be used in combination with the resin composition of the present invention within the range that does not impair the effects of the present invention.
Further, if necessary, various additives such as an inorganic filler, a colorant, an antioxidant, a light stabilizer, a light absorber and a nucleating agent can be added.

[0030]

As described above, according to the flame retardant technology of the present invention, a flame-retardant engineering plastic containing no halogen, having a high degree of flame retardancy, suppressing smoke generation, and less likely to generate corrosive gas. A composition is provided.

[0031]

EXAMPLES Hereinafter, the effects of the present invention will be clarified by showing specific examples, but the present invention is not limited to these examples.

In the following examples and comparative examples, the following raw materials were used.

Component A (A1): Polybutylene terephthalate resin (Mitsubishi Chemical Co., Ltd., Nobad Wool 5010) (A2): Polyethylene terephthalate resin (Mitsubishi Chemical Co., Novapet 6010G) (A3): Nylon 6 ( Amylan CM1 manufactured by Toray Industries, Inc.
007) (A4): Nylon 66 (manufactured by Toray Industries, Inc., Amilan CM)
3001-N) (A5): Polycarbonate (manufactured by Teijin Chemicals, Panlite L 1250) (A5): Modified polyphenylene oxide (manufactured by Mitsubishi Gas Chemical Co., Inc., Iupiace AH 40) B component (B1): Heat expansion Graphite A (Chuo Kasei Co., Ltd., CA
-60) (B2): Heat-expandable graphite B (manufactured by Chuo Kasei Co., Ltd., CA
-60 was subjected to classification and pulverization treatment and adjusted to have expandability and particle size distribution shown in Table 1) (B3): Heat-expandable graphite C (manufactured by Chuo Kasei Co., Ltd., CA
-60 was subjected to classification and pulverization treatment and adjusted to have the expandability and particle size distribution shown in Table 1) Table 1 shows the expandability and particle size distribution of B1 to B3.

[0034]

[Table 1]

C component (C1): surface-treated red phosphorus (Rin Kagaku Kogyo KK, Novarred 120) D component (D1): ammonium polyphosphate surface-treated with melamine resin (Rin Kagaku Kogyo KK) , Nova White PA-
6) (D2): Surface-untreated ammonium polyphosphate (manufactured by Rin Kagaku Kogyo KK, Nova White PA-2) E component (bromine-based flame retardant) (E1): Brominated phenoxy resin (manac Co., Ltd.) ,
A mixture of EBR107) and antimony trioxide (manufactured by Tosoh Corporation, frame cut 610R) in a weight ratio of 2/1.

(E2): Brominated polystyrene (manufactured by Nissan Ferro Co., Ltd., Pyrocheck 68PB) and antimony pentoxide (manufactured by Nissan Chemical Co., Ltd., Sun Epoch NA-103).
Mixture with 0) in a weight ratio of 5/1.

(E3): A mixture of brominated polystyrene (manufactured by Nissan Ferro Co., Ltd., Pyrocheck 68PB) and antimony trioxide (manufactured by Tosoh Corporation, flame cut 610R) in a weight ratio of 3/1.

Examples 1 to 7, Comparative Examples 1 to 1
1 Polybutylene terephthalate resin was used as a raw material in the blending ratio shown in Table 2 at 235 ° C. by extrusion kneading, and at 235 ° C., injection molding was performed to prepare a test piece. For polyethylene terephthalate resin, a test piece was prepared by extrusion kneading at 260 ° C and injection molding at 260 ° C. Flame retardance is JIS K
Oxygen index based on 7201 (hereinafter sometimes abbreviated as OI), UL 94 vertical burning test (1/16 inch piece), and NBS method in flame mode were used for evaluation. Table 2 shows the results.

[0039]

[Table 2]

First, the case where the polybutylene terephthalate resin (A1) is used as the polyester resin (component A) will be described.

As is clear from Comparative Example 1, Comparative Example 2 and Comparative Examples 3 to 4 in Table 2, heat-expandable graphite (component B), red phosphorus (component C), ammonium polyphosphate (component D). In each of the above, the improvement of OI and UL 94 is small. However, as shown in Examples 1 to 4, by using the B component and the C component together, the B component and the D component together, or the B component and the C component and D component together, the polybutylene terephthalate resin is highly flame retarded. The synergistic effect that sex is achieved is clear.

The swelling property is 200 ml / g and is 80
From the results of Example 1 and Comparative Examples 5 to 6 in Table 2, the expansiveness is less than 200 ml / g, because the combined effect of the expansive graphite (B1) having a particle size ratio of 20% by weight or less passing through the mesh sieve is It is clear from the fact that a higher degree of flame retardancy is achieved compared to the combined effect of non-expandable graphite (B2) and expansive graphite (B3) having a particle size ratio of 20% by weight or more passing through a 80-mesh sieve. is there. In addition, the composition of the present invention significantly suppresses smoke emission compared to a composition containing a brominated flame retardant.
This is clear by comparing Example 4 and Comparative Example 7.

Next, the case where the polyethylene terephthalate resin (A2) is used as the polyester resin will be described.

As shown in Examples 5 to 7 and Comparative Examples 8 to 10 of Table 2, the polyethylene terephthalate resin is highly flame-retardant by using the B component and the C component together or the B component and the D component together. The synergistic effect that is achieved is clear. Further, it is clear from the comparison between Examples 5 to 6 and Comparative Example 11 that the composition of the present invention significantly suppresses the smoke generation property as compared with the composition containing the brominated flame retardant.

Examples 8 to 13 and Comparative Examples 12 to 21 The nylon 6 resin was used as the raw material at the compounding ratio shown in Table 3 to be 23.
A test piece was prepared by extrusion kneading at 5 ° C and injection molding at 235 ° C. A nylon 66 resin was extruded and kneaded at 285 ° C and injection-molded at 285 ° C to prepare a test piece. The flame retardancy was evaluated by an oxygen index according to JIS K 7201, a UL 94 vertical burning test (1/16 inch piece), and a flaming mode of the NBS method. Table 3 shows the results.

[0046]

[Table 3]

First, the case where nylon 6 resin (A3) is used as the polyamide resin (component A) will be described.

Comparative Examples 12 to 13 and Comparative Example 1 in Table 3
4. As is clear from Comparative Examples 15 to 16, the heat-expandable graphite (B component), the red phosphorus (C component), and the ammonium polyphosphate (D component) alone are OI and UL.
The 94 improvement is small. However, as shown in Examples 8 to 9, a combination of B component and C component or B component and D component is used.
The synergistic effect that a high degree of flame retardancy is achieved for nylon 6 resin by using the components together is clear. Further, it is clear from the comparison between Examples 8 to 9 and Comparative Example 17 that the composition of the present invention remarkably suppresses the smoke generation property as compared with the composition containing the brominated flame retardant.

Next, the case where nylon 66 resin (A4) is used as the polyamide resin will be described.

Examples 10 to 13 and Comparative Example 1 in Table 3
8 to Comparative Example 20, as shown in FIG.
The synergistic effect that a high degree of flame retardancy is achieved for the nylon 66 resin by using the B component and the D component together or the B component and the C component and the D component together is clear. Further, it is clear from the comparison between Examples 11 to 12 and Comparative Example 21 that the composition of the present invention remarkably suppresses smoke emission as compared with the composition containing the brominated flame retardant.

Examples 14 to 15 and Comparative Examples 22 to 23 Bisphenol A as a polycarbonate resin (A5)
Using the above, the raw materials were extruded and kneaded at 270 ° C. at the compounding ratios shown in Example 14 and Comparative Example 22 shown in Table 4, and test pieces were prepared by injection molding at 270 ° C.
As the modified polyphenylene oxide (A6), polystyrene modified polyphenylene oxide was used, and the raw materials were extruded and kneaded at 270 ° C. at the compounding ratios shown in Table 4 and Comparative Example 23, and a test piece was prepared by injection molding. Was prepared. Flame retardancy is based on the oxygen index according to JIS K 7201 and UL 94 vertical combustion test (1/16
Inch piece) and the flame mode of the NBS method. Table 4 shows the results.

[0052]

[Table 4]

Comparing Example 14 and Example 15 with Comparative Example 22 and Comparative Example 23, respectively, the polycarbonate resin composition and the modified polyphenylene oxide resin composition according to the present invention become the corresponding resin compositions with the brominated flame retardant. It shows clear flame retardancy and very low smoke emission.

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Claims (6)

[Claims] 1. (A) Engineering plastic 1
100 parts by weight of (B) heat-expandable graphite, 1 to 30 parts by weight, (C) 1 to 30 parts by weight of red phosphorus and / or (D) 1 to 30 parts by weight of a phosphorus compound. Flame-retardant engineering plastic composition. 2. The difficulty according to claim 1, wherein the engineering plastic contains one or more resins selected from the group consisting of polyester resins, polyamide resins, polycarbonate resins and modified polyphenylene oxide resins. Flammable engineering composition. 3. The flame-retardant engineering plastic composition according to claim 1, wherein the engineering plastic is a polyester resin or a polyamide resin. 4. The thermally expanded graphite is from room temperature to 800 to 10
The difference in specific volume before and after rapid heating to 00 ° C is 100 ml / g
2 or more with a particle size of 80 mesh or more
The flame-retardant engineering plastic composition according to any one of claims 1 to 3, which is a heat-expandable graphite having a particle size distribution of 0% by weight or less. 5. The red phosphorus is surface-treated with one or two or more compounds selected from the group consisting of thermosetting resins and inorganic compounds.
The flame-retardant engineering plastic composition described in 1. 6. The phosphorus compound is one or more selected from the group consisting of esters of phosphorus oxo acids (hereinafter referred to as “phosphoric acid”), phosphates, salts of phosphoric acid esters, and condensed phosphates. The flame-retardant engineering plastic composition according to any one of claims 1 to 4.