JPH10251528A - Flame-retardant thermoplastic resin composition excellent in tracking resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition highly excellent in tracking resistance by compounding a thermoplastic resin with ammonium polyphosphate, a halogen-based polymeric flame retarding, antimony trioxide and inorganic filler in specified proportions. SOLUTION: This resin composition is obtained by compounding (A) 100 pts.wt. of a thermoplastic resin (pref. polyamide- or polyester-based one) with (B) 0.5-50 pts.wt. of ammonium polyphosphate. (C) 5-50 pts.wt. of a halogen-based polymeric flame retarding (esp. pref. a bromine-based polystyrene flame retardant such as polydibromostyrene or polytribromostyrene), (D) 0-15 pts.wt. of antimony trioxide, and (E) 0-50 pts.wt. of an inorganic filler (e.g. calcium carbonate, talc). This composition is pref. used by molding (in particular, injection or extrusion molding) into e.g. electrical parts. Thereby, improvement in flame retardancy and tracking resistance as well as retaining the properties inherent in thermoplastic resin can be accomplished in this resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant thermoplastic resin composition having excellent tracking resistance and an electric component molded therefrom.

[0002]

2. Description of the Related Art Thermoplastic resins represented by polyamides and polyesters are generally excellent in moldability, mechanical properties, electrical properties, and chemical resistance.
It is widely used in applications such as automobiles and electric / electronic devices, and has achieved high functionality and high performance by various prescriptions according to the characteristics and required needs of each thermoplastic resin.

However, in recent years, with the advancement of required characteristics, thermoplastic resins have been expected to have higher functions and higher performance, and the improvement of tracking resistance, which is one of the electric characteristics, has been further improved. This is one of the characteristics that are expected to have higher functions.

[0004] Conventionally, as a method for improving the tracking resistance of a thermoplastic resin, it has been known to add a sulfate such as magnesium sulfate, calcium sulfate, barium sulfate or the like to the thermoplastic resin. For example,
Japanese Patent Application Publication No. -10053 discloses that barium sulfate is blended with polybutylene terephthalate, and Japanese Patent Publication No. 4-32111 discloses that finely baked magnesium sulfate is blended with thermoplastic polyester. ing.

However, in the prescription according to the above publication,
Although the tracking resistance is improved, the comparative tracking index (CTI) is not sufficient at about 400 V.
Impact resistance, tensile elongation, and the like are reduced, and the mechanical properties inherent to thermoplastic resins cannot be maintained.

On the other hand, Japanese Patent Application Laid-Open No. Hei 7-145304 discloses that a glycidyl group-containing ethylene copolymer is blended with a polyester resin and a sulfate of a group IIa element of the periodic table to maintain mechanical properties. And a resin composition having excellent tracking resistance characteristics.

However, the blending of the glycidyl group-containing ethylene copolymer into the polyester resin in the above-mentioned publication is expected to suppress the adverse effect on mechanical properties due to the blending of a sulfate, and therefore the tracking resistance is not improved. It was hard to say that the formulation was expected to improve significantly.

Further, JP-A-2-225555 discloses a flame-retardant polyester resin composition comprising a halogenated flame retardant, an inorganic filler and a polyphosphate ester in a thermoplastic polyester resin. In this publication,
In addition to flame retardancy, tracking resistance has also been evaluated as mechanical and electrical properties. However, the comparative tracking index (CTI) of the described resin composition is 250 to 575 V, which is not sufficient.

On the other hand, it has been conventionally known that ammonium polyphosphate is blended with a thermoplastic resin. However, these are blends expected to have an effect as a flame retardant, and are not effective in improving tracking resistance. There was no knowledge so far. For example, Japanese Patent Application Laid-Open No. 2-235555 discloses that polyester resins (i) polyphosphonates, (ii) ammonium polyphosphate and (iii)
A flame retardant thermoplastic composition comprising a halogenated benzene sulfonate is disclosed. However, although this publication describes flame retardancy and mechanical properties, it does not disclose any tracking resistance as an electrical property. Also, JP-A-9-208812 discloses that
A flame-retardant polyester resin composition comprising a polyester resin and a phosphorus compound and / or ammonium polyphosphate is disclosed. However, even in this publication, only flame retardancy and molding workability are described, but no description is given of the tracking resistance which is an electrical characteristic.

[0010]

SUMMARY OF THE INVENTION The present invention relates to the anti-tracking property, while maintaining the mechanical properties inherent in a thermoplastic resin in a composition completely different from that of the prior art using a sulfate, and further improving the anti-tracking property. The object of the present invention is to provide a flame-retardant thermoplastic resin having improved heat resistance.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, a thermoplastic resin containing ammonium polyphosphate, a halogen-based polymer flame retardant,
The present inventors have found that a resin composition in which antimony trioxide and an inorganic filler are blended in a specific ratio has extremely excellent tracking resistance, and also maintains flame retardancy and mechanical properties inherent to the thermoplastic resin. The invention has been completed.

That is, the present invention relates to (a) 100 parts by weight of a thermoplastic resin, (b) 0.5 to 50 parts by weight of ammonium polyphosphate, (c) 5 to 50 parts by weight of a halogen-based polymer flame retardant (d) ) Antimony trioxide: 0 to 15 parts by weight (e) Inorganic filler: 0 to 50 parts by weight A flame-retardant thermoplastic resin composition having excellent tracking resistance.

Hereinafter, the present invention will be described in detail. Examples of the thermoplastic resin (a) used in the present invention include: polyolefins such as polyethylene and polypropylene; polyamides such as nylon 6, nylon 66 and nylon 12; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyphenylene sulfide; Polycarbonate, acrylonitrile / butadiene / styrene copolymer, ethylene / vinyl alcohol copolymer and the like can be mentioned. Above all, in consideration of the tracking resistance and the heat resistance in actual use, polyamides and polyesters are preferred, and polyesters are more preferred.

As the ammonium polyphosphate (b) used in the present invention, commercially available products may be used as they are, but aminosilanes such as aminosilane may be used for the purpose of improving heat resistance in consideration of high temperature treatment or use. What has been surface-treated with the above surface treatment agent is preferred. The amount of ammonium polyphosphate used is 0.5 to 50 parts by weight, preferably 2 to 20 parts by weight, more preferably 3 to 50 parts by weight, based on 100 parts by weight of the thermoplastic resin.
It is blended in a proportion of 15 parts by weight. When the amount of ammonium polyphosphate is less than 0.5 part by weight, no improvement in tracking resistance is observed, and when the amount exceeds 50 parts by weight, the physical property value of the flame-retardant thermoplastic resin composition is It is not preferable because it decreases.

The (c) halogen-based polymer flame retardant used in the present invention includes halogenated epoxy resins, halogenated polycarbonates, halogenated polystyrenes, halogenated cyanurate resins, halogenated polyphenylene ethers, and the like. Brominated bisphenol-based epoxy resin, brominated bisphenol-based phenoxy resin, brominated bisphenol-based polycarbonate,
Brominated polymer flame retardants such as polydibromostyrene, polytribromostyrene, polypentabromostyrene, and polybromocarbonate are exemplified. Of these, brominated polystyrene flame retardants such as polydibromostyrene, polytribromostyrene and polypentabromostyrene are more preferred. The amount of these flame retardants used is 5 to 50 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the thermoplastic resin. When the amount of the flame retardant is less than 5 parts by weight, the effect as a flame retardant is not exhibited, and when the amount is more than 50 parts by weight, the physical property value of the flame retardant thermoplastic resin composition is reduced. Not preferred.
Further, the flame retardant may be used in combination with one or more other flame retardants depending on the required properties.

The amount of (d) antimony trioxide used in the present invention is from 0 to 15 parts by weight, preferably from 0 to 10 parts by weight, more preferably from 1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin. Parts are blended. If the amount of antimony trioxide is more than 15 parts by weight, the physical properties of the flame-retardant thermoplastic resin composition are undesirably reduced.

Specific examples of the inorganic filler (e) used in the present invention include calcium carbonate, calcium silicate (wollastonite), talc, kaolin, mica, titanium oxide, alumina, silica, ferrite and the like. ,
Examples include inorganic fibers such as glass fibers, carbon fibers, metal fibers, boron fibers, potassium titanate fibers, and ceramic fibers. The amount of the inorganic filler used is 0 to 50 parts by weight, preferably 0 to 30 parts by weight, more preferably 5 to 30 parts by weight based on 100 parts by weight of the thermoplastic resin. In particular, when the inorganic filler is glass fiber, if the compounding amount exceeds 50 parts by weight, the surface of the molded article is unpreferably deteriorated. Further, the inorganic filler may be used in combination with one or more other inorganic fillers depending on the required properties.

The flame-retardant thermoplastic resin composition of the present invention may contain other additives according to the required properties, for example, a heat-resistant agent, a weathering agent containing an ultraviolet absorber, a flame-retardant, an antistatic agent,
Lubricants, plasticizers, nucleating agents, foaming agents, coloring agents, stabilizers, coupling agents and the like can be added.

The flame-retardant thermoplastic resin composition of the present invention is prepared by mixing a thermoplastic resin, ammonium polyphosphate, a halogen-based polymer flame retardant, antimony trioxide and an inorganic filler with a known kneader such as a twin screw extruder. It can be easily prepared by melt-kneading.

A molded article such as an electric part can be produced by using the resin composition obtained in the present invention. Electrical components
The resin composition obtained above is molded by subjecting it to a known molding method such as injection molding, extrusion molding, blow molding, vacuum molding, press molding, etc., and in particular, an electric component obtained by injection molding or extrusion molding Is useful.

As the obtained electric component, a distribution component is particularly preferable, and specific examples include a terminal block, a breaker, a connector, a switch, a relay, an electric circuit board, an electromagnetic switch, a coil bobbin, a transformer, a socket, and a fuse holder. More preferably, the electrical components to which the droplets may be applied include a connector of a washing machine and an electric circuit board of a microwave oven.

[0022]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. Test pieces were prepared from the compositions obtained in Examples and Comparative Examples, and the physical properties of the test pieces were measured according to the following methods. (1) Tracking resistance: IEC112 (UL746)
The comparative tracking index (CTI) [unit: V] measured using the solution A was evaluated according to A). (2) Elongation (tensile test): Based on ASTM D638, an ASTM No. 1 piece was used for the test piece shape, and the test piece thickness =
It was evaluated at 1/8 inch. (3) Impact test: Based on ASTM D256, evaluation was performed with a test piece notch and a test piece thickness of 1/8 inch. (4) Flammability: Evaluated based on UL94 at a specimen thickness of 1/32 inch.

(Sample preparation method) A thermoplastic resin and various additives were blended in proportions corresponding to the examples and comparative examples shown in Table 1, and were charged all at once into a twin-screw kneader. The glass fiber was introduced using a side feeder, and a target composition was obtained by melt-kneading. The twin-screw kneader used was a 35 mmφ vent-type twin-screw kneader (L / D = 40), a co-rotating, deep groove type, rotating speed of 100 rpm, cylinder set temperature of 260 ° C., and discharge rate of 30 kg / hr. I did it.

The amounts (units: parts by weight) of the compositions used in Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 1.

Table 2 shows the evaluation results of the resin compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 7.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

According to the present invention, a flame-retardant heat-resistant material having extremely excellent tracking resistance can be obtained by blending a thermoplastic resin with ammonium polyphosphate, a halogen-based polymer flame retardant, antimony trioxide and an inorganic filler in a specific ratio. A plastic resin composition and an electric part molded therefrom are obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 101: 02)

Claims (5)

[Claims] 1. (a) 100 to 100 parts by weight of a thermoplastic resin, (b) 0.5 to 50 parts by weight of ammonium polyphosphate (c) 5 to 50 parts by weight of a halogen-based polymer flame retardant (d) Antimony trioxide 0 to 15 parts by weight (e) an inorganic filler 0 to 50 parts by weight. A flame-retardant thermoplastic resin composition having excellent tracking resistance. 2. The flame-retardant thermoplastic resin composition according to claim 1, wherein the thermoplastic resin is a polyester resin. 3. The flame-retardant thermoplastic resin composition according to claim 1, wherein the halogen-based polymer flame retardant is a brominated polystyrene flame retardant. 4. An electric component obtained by molding the flame-retardant thermoplastic resin composition according to claim 1, 2 or 3. 5. The electric component according to claim 4, wherein the electric component is a power distribution component.