JP2000290484A - Flame-retardant resin composition and molding product comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonhalogen flame-retardant polyester resin composition controlling fire spreading by drip. SOLUTION: This flame-retardant resin composition is obtained by formulating (A) 100 pts.wt. of a thermoplastic polyester resin with (B) 5-50 pts.wt. of red phosphorus, (C) 5-70 pts.wt. of cyanuric acid and/or its derivative or tetrazole-based compound and (D) 1-50 pts.wt. of a boron-based compound. This molding product is obtained by processing the composition by injection molding, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester resin composition represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6 naphthalate, etc., which has excellent flame retardancy, and a molded article obtained by molding the same. More specifically, the present invention is suitable for molded articles such as electric motors, cover members, connectors, switches, relays, coil bobbins, and other electric and electronic equipment parts, automobile parts, and machine parts.

[0002]

2. Description of the Related Art Since thermoplastic polyester resins are inherently flammable, it is necessary to balance general chemical and physical properties in order to use them as industrial materials. That is, safety, particularly flame retardancy, is often required. In general, as a method of making a thermoplastic polyester resin flame-retardant, there is a method of mixing a halogen-based compound as a flame retardant and further mixing an antimony compound as a flame-retardant auxiliary.

However, compositions using a halogen compound or an antimony compound emit a large amount of smoke during combustion. Further, during processing, there is a problem that hydrogen halide gas is generated and the mold is corroded. Particularly in recent years, from the viewpoint of environmental protection, the use of halogen compounds has been suppressed.

[0004] Therefore, there is a demand for a method of flame retardation using a non-halogen flame retardant. As a method therefor, as shown in JP-A-48-4598, there is known a method in which flame retardation is achieved by adding red phosphorus. However, red phosphorus, which is an elemental phosphorus, has poor stability to reactions and impacts caused by moisture absorption, and requires careful handling.
JP-A-51-105996 and JP-B-54-392.
As described in Japanese Patent Publication No. 00, an improvement has been attempted by coating red phosphorus with a thermosetting resin or by microencapsulating and using the same. Further, as another flame retarding method, Japanese Unexamined Patent Publication No.
No. 78560, JP-A-5-287119, JP-A-5-287119
295164, JP-A-5-339417, and the like, there is also a method of using red phosphorus and another flame retardant in combination, and any resin composition is a useful flame-retardant resin material that does not use a halogen-based flame retardant. There were problems that the high flame retardant effect was insufficient and the excellent mechanical properties of the thermoplastic resin were impaired.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a non-halogen flame-retardant polyester resin composition which solves the above-mentioned problems of the prior art and suppresses the spread of fire due to drip.

[0006]

The object of the present invention is to provide (B) 5 to 50 parts by weight of red phosphorus and (C) cyanuric acid and / or a derivative thereof or tetrazole per 100 parts by weight of a thermoplastic polyester resin. Use of a flame-retardant polyester resin composition obtained by mixing 5 to 70 parts by weight of a base compound and 1 to 50 parts by weight of a boron compound (D), or a molded article obtained by processing this composition by injection molding or the like. Achieved by The same effect can be achieved with a flame-retardant polyester resin composition obtained by further mixing (E) 1 to 100 parts by weight of a filler with this composition and a molded product thereof.

The thermoplastic polyester resin (A) used in the present invention is a polyester of a diol (or an ester-forming derivative thereof) and a dicarboxylic acid (or an ester-forming derivative thereof). The compounds may each be used alone or in a mixture. Further, a compound having a hydroxyl group and a carboxylic acid group in one molecule such as lactone may be combined.

The diol component of the thermoplastic polyester resin (A) used in the present invention includes ethylene glycol,
Propylene 1,2-glycol, propylene 1,3-glycol, 1,4-butanediol, 2,3-butanediol, hexane 1,6-diol, octane 1,8-
Diol, neopentyl glycol, decane 1,10-
Examples thereof include aliphatic diols such as diol, diethylene glycol, and triethylene glycol. Preferred aliphatic diols are ethylene glycol, 1,4
-Butanediol.

Also, 1,2-cyclohexanediol,
Examples thereof include 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol. These alicyclic diols can be used in either the cis or trans configuration, or as a mixture of both. A preferred cycloaliphatic diol is 1,4-cyclohexanedimethanol.

Furthermore, aromatic dihydric phenols such as resorcin, hydroquinone and naphthalene diol, polyethylene glycol having a molecular weight of 400 to 6000, polyglycols such as polypropylene glycol and tetramethylene glycol, and bisphenol A can also be mentioned. Further, the above-mentioned diol component may be a diester such as diacetate or dipropionate.

The dicarboxylic acid component of the thermoplastic polyester resin (A) used in the present invention includes isophthalic acid, terephthalic acid, orthophthalic acid, 2,2'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenylether dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6
-Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid and 1,2-di (4-carboxyphenyl) ethane, adipic acid, succinic acid, oxalic acid, malonic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, cyclohexanedicarboxylic acid Examples thereof include aliphatic and alicyclic dicarboxylic acids such as acids. The above component may be an ester derivative, for example, an alkyl ester such as methyl or ethyl, or an aryl ester such as phenol or cresol. Preferred dicarboxylic acids are terephthalic acid and naphthalenedicarboxylic acid.

As the thermoplastic polyester resin (A) used in the present invention, these diol components and dicarboxylic acid components may be used alone, or have a hydroxyl group and a carboxyl group in one molecule like caprolactone. Compounds may be used. Further, two or more diols or dicarboxylic acids may be combined. The obtained polyester resins may be used alone or in combination. Specific examples include a copolymerized polyester resin of butylene terephthalate and dimer acid.

Of these, polybutylene terephthalate resin, a copolymerized polyester resin obtained by copolymerizing butylene terephthalate with dimer acid, and the like, and a mixture of polybutylene terephthalate and a copolymerized polyester resin are particularly preferred.

The amount of (B) red phosphorus used in the present invention is as follows:
(A) 5 to 50 parts by weight, preferably 5 to 30 parts by weight, per 100 parts by weight of the thermoplastic polyester resin. If the amount is less than 5 parts by weight, sufficient flame retardancy cannot be imparted. If the amount is more than 50 parts by weight, uniform dispersion becomes difficult and not only the mechanical properties of the molded product are lowered, but also the red phosphorus itself Reduces the thermal stability and reduces the flame retardancy.

The (C) cyanuric acid and / or a derivative thereof used in the present invention include cyanuric acid, isocyanuric acid, trimethyl cyanurate, trismethyl isocyanurate, triethyl cyanurate, triethyl isocyanurate, and tri (n-propyl) cyanurate. , Tri (n-propyl) isocyanurate, diethyl cyanurate, N, N'-diethyl isocyanurate, methyl cyanurate, methyl isocyanurate and the like, and adducts of these with melamine, urea and the like are also included. Among them, melamine cyanurate is preferably used from the viewpoint of the flame retardant effect.

Specific examples of the (C) tetrazole compound used in the present invention include 5,5'-bistetrazole 2-
Examples include ammonium, 5,5′-bistetrazole 2-aminoguanidine, and 5,5′-bistetrazole piperazine.

The compounding amount of (C) cyanuric acid and / or a derivative thereof or a tetrazole compound is 5 to 70 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the thermoplastic polyester resin. If the amount is less than 5 parts by weight, the flame retardant effect of these compounds is not sufficient. In particular, a blending amount of 5 to 50 parts by weight is preferable since the balance between flame retardancy and mechanical properties is best.

Specific examples of the boron compound (D) used in the present invention include orthoboric acid, metaboric acid, tetraboric acid, boron oxide, borate, borate ester, phenylboric acid, and boroxine. Among them, zinc borate is preferably used in view of the flame retardant effect and the low smoke generating effect.

(D) The compounding amount of the boron compound is (A)
1 to 100 parts by weight of the thermoplastic polyester resin,
It is 50 parts by weight, preferably 1 to 30 parts by weight. If the amount is less than 1 part by weight, the flame retardant effect is insufficient. If the amount is more than 50 parts by weight, not only the mechanical properties of the molded article are reduced, but also the fire spread is promoted, so that the flame retardancy is reduced. Let me do it. In particular, a blending amount of 1 to 30 parts by weight is preferable because the balance between flame retardancy and mechanical properties is best.

The amount of the filler (E) is 1 to 100 parts by weight based on 100 parts by weight of the thermoplastic polyester resin. If the compounding amount of the filler is less than 1 part by weight, the effect of compounding the filler is not obtained, and if it exceeds 100 parts by weight, the mechanical properties of the molded article deteriorate, which is not preferable.

Specific examples of the filler (E) used in the present invention include glass fibers, glass beads, glass flakes, steel fibers, carbon fibers, and brass fibers.

The flame-retardant polyester resin composition of the present invention may comprise an antioxidant, a heat stabilizer, an impact modifier such as various elastomers, a nucleating agent, a plasticizer, and a release agent as long as the object of the present invention is not impaired. Ordinarily used additives such as pigments and dyes such as titanium oxide and carbon black may be further added.

The process for producing the flame-retardant polyester resin composition of the present invention is carried out by, for example, using a thermoplastic polyester resin, red phosphorus, cyanuric acid and / or a derivative thereof, a tetrazole compound, a boron compound, etc., by means of various feeders. A method in which the mixture is supplied to an extruder and melt-kneaded. Alternatively, master pellets prepared by previously melting and kneading red phosphorus with a thermoplastic polyester resin may be used.

The flame-retardant polyester resin composition of the present invention can be formed by injection molding, extrusion molding or the like.

Examples of molded articles using the flame-retardant polyester resin composition of the present invention include electric and electronic parts, such as switches, connectors, plugs, motor parts, and housings.

[0026]

According to the present invention, a flame-retardant polyester resin composition having excellent flame retardancy and mechanical properties without using a halogen-based flame retardant, and a molded article thereof can be obtained.

[0027]

EXAMPLES The present invention will be described below by way of examples, which are merely examples, and the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”.
The method for measuring the characteristics is as follows.

(1) Mechanical properties ASTM-D was used for tensile test pieces obtained by injection molding.
The tensile strength was measured according to 638.

(2) Flame Retardancy Underwriters Labor for combustion test specimens (1/16, 1/32 inch) obtained by injection molding
The flame retardancy as defined by the safety standard UL94 from atories was evaluated. Flame retardancy level is V-0> V-
1>V−2> HB. In addition, the results that do not belong to any of these are regarded as “out of specification”.

Examples 1, 2, 5 to 14 and Comparative Examples 1 to
8] Table 1 with respect to 100 parts by weight of polybutylene terephthalate resin (PBT124 manufactured by Kanebo Gosen Co., Ltd.)
As shown in Table 2, various red phosphorus, cyanuric acid and / or a derivative thereof, or a tetrazole compound and a boron compound are heated at 220 to 250 ° C. using an extruder.
And the strands were extruded and made into chips by a cutter.

After the obtained chip was dried at 130 ° C. for 4 to 5 hours, a cylinder temperature of 235 to 245 ° C. and a mold temperature of 80 were used.
Under a condition of ° C., a tensile test specimen specified in ASTM-D638 and a combustion test specimen based on UL94 were prepared by injection molding.

The measurement results of the composition, flame retardancy, and mechanical properties of each sample are shown in Table 1.

In the table, PBT120 is a polybutylene terephthalate resin (manufactured by Kanebo Gosen Co., Ltd.)
2120 is a dimer acid copolymerized polyester resin (manufactured by Kanebo Gosen Co., Ltd.), and the phosphate ester is a condensed phosphate ester represented by Chemical Formula 1 (manufactured by Asahi Denka Co., Ltd .; ADK STAB PFR). Melamine cyanurate is O
MV (manufactured by Chemie), zinc borate is 2335 manufactured by Tomita Pharmaceutical Co., Ltd., and glass fiber is Nippon Electric Glass Co., Ltd.
ECS03 T-123H was used.

[0034]

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[Examples 3, 4, 15, and 16] Polybutylene terephthalate resins were formed into chips in the same manner as in Example 1 except that the types and compositions were changed as shown in Table 1.

From Examples 1 to 16, it was found that by blending red phosphorus, cyanuric acid salt, tetrazole compound, or boron compound with various thermoplastic polyester resins, a high level of difficulty corresponding to UL94 V-0 was obtained in a combustion test. It showed flammability. Also, the amount of smoke generated during combustion was small.

Compared with Comparative Examples 1 and 3, when the amount of red phosphorus is smaller, the flame retardancy is reduced to V-2 or less. Comparative Example 2
Conversely, when the amount of red phosphorus is large, the flame retardancy is conversely V
-2, and the balance of mechanical properties is remarkably inferior to the embodiment.

As compared with Comparative Example 4, when the amount of the cyanuric acid salt is small, the flame retardancy is reduced to V-2. Contrary to Comparative Example 5, when the content of cyanuric acid salt is large, the balance of the mechanical properties is clearly inferior to that of Example.

As compared with Comparative Example 6, when the compounding amount of the boron compound was small, the flame retardancy was equivalent to V-2 of UL94, which was inferior to that of Examples. Contrary to Comparative Example 7, when the amount of the boron-based compound was large, the burning time was prolonged and the V-
0 standard cannot be satisfied, and the flame retardancy level is reduced to UL94 V-1. Moreover, the mechanical properties were significantly reduced.

From Comparative Example 8, when the blending amount of the filler was large,
Both tensile strength and tensile elongation decreased.

[0041]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3:38) (72) Inventor Toshio Honma 4-1 Kanebocho, Hofu City, Yamaguchi Prefecture Kanebo Gosen Co., Ltd. (72) Inventor Masaki Yamamoto 4-1 Kanebocho, Hofu City, Yamaguchi Prefecture Kanebo Gosen Co., Ltd. F-term (reference) 4J002 CF031 DA056 DK008 EU007 EU187 FD019 FD136 GM00 GN00 GQ00

Claims (5)

[Claims] (A) a thermoplastic polyester resin 100
(B) 5 to 50 parts by weight of red phosphorus and (C)
5 to 70 parts by weight of cyanuric acid and / or its derivative or tetrazole compound and (D) boron compound 1
A flame-retardant resin composition obtained by mixing 50 parts by weight. 2. The flame-retardant resin composition according to claim 1, wherein the component (C) is melamine cyanurate. 3. The flame-retardant resin composition according to claim 1, wherein the component (D) is zinc borate. 4. A thermoplastic polyester resin (A) 100
The flame-retardant resin composition according to claim 1, further comprising 1 to 100 parts by weight of a filler based on parts by weight. 5. A molded article comprising the flame-retardant resin composition according to claim 1.