TWI814911B - Flame retardant polybutylene terephthalate resin composition - Google Patents

Abstract

[Problem] To provide a polybutylene terephthalate resin composition comprising an alkaline metal inorganic compound and having excellent flame retardant properties. [Solution] The abovementioned problem is solved by using a flame retardant polybutylene terephthalate resin composition comprising a polybutylene terephthalate resin in which a terminal carboxyl group amount is 50 meq/kg or less, an alkaline metal inorganic compound, and antimony trioxide, characterized in that in the entirety of the composition, the total content of an epoxy group is 0.010 mol/kg or more and 0.020 mol/kg or less.

Description

Flame retardant polybutylene terephthalate resin composition

The present invention relates to a flame-retardant polybutylene terephthalate resin composition, a black foreign matter inhibitor, a method for inhibiting black foreign matter, and a method for producing a flame-retardant polybutylene terephthalate resin composition. , a molded article obtained from a flame-retardant polybutylene terephthalate resin composition.

Polybutylene terephthalate resin (PBT resin) has excellent various electrical properties, so it is widely used as an engineering plastic in various applications such as electrical and electronic components. In these applications, the materials used are required to be flame retardant in order to prevent fires caused by tracking. Since polybutylene terephthalate resin itself has insufficient flame retardancy, it is used in the form of a flame retardant resin composition to which a flame retardant is added.

Patent Document 1 introduces a method for producing a brominated epoxy compound-based flame retardant. This production method is characterized in that diglycidyl ethers of alcohols containing aromatic nuclei, di- or polyglycidyl ethers of polyhydric phenols, diepoxypropyl esters of aromatic dibasic acids, and alkanes are used. Monoglycidyl ether of phenols, monoglycidyl ether ester of hydroxybenzoic acid, (β-methyl) epichlorohydrin addition product of p-amine phenol, or aromatic di- or poly Aromatic epoxy compounds such as polyglycidylamine as the base, or chlorohydrin compounds as precursors thereof, are brominated by adding bromine, and the resulting bromine Brominated bromohydrin compounds or brominated chlorohydrin compounds are subjected to ring-closed epoxidation using alkali metal hydroxides through dehydrobromination or dehydrochlorination.

Patent Document 2 introduces brominated epoxy compound-based flame retardants for engineering thermoplastics. The molecular weight of this flame retardant is preferably 7,000 to 50,000 daltons, and the epoxy equivalent is preferably greater than 10,000g/eq.

In addition, it has been known from the past that molecular weight, epoxy equivalent, etc. have an influence on the viscosity increase of epoxy compounds. Since the carbide generated by this viscosity increase inhibits black foreign matter (BS: Black Speck) from being mixed into the molded product, the molecular weight and epoxy equivalent range have been adjusted in the past. For example, Patent Document 3 describes that the generation of black foreign matter in molded articles of polybutylene terephthalate resin composition can be suppressed by using an epoxy compound with an epoxy equivalent of 600 to 1500 g/eq. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 60-016952 [Patent Document 2] Japanese Patent No. 5143419 [Patent Document 3] Japanese Patent No. 6100983

[Problem to be solved by the invention]

An object of the present invention is to provide a polybutylene terephthalate resin composition containing a basic metal inorganic compound and excellent in flame retardancy. [Means used to solve problems]

As a result of intensive research in order to solve the above-mentioned problems, the present inventors found that by using a polybutylene terephthalate resin characterized by containing a terminal carboxyl group content of 50 meq/kg or less, and an alkaline metal A flame-retardant polybutylene terephthalate resin composition containing an inorganic compound, and antimony trioxide, and the total content of epoxy groups in the entire composition is 0.010 mol/kg or more and 0.020 mol/kg or less, and The above-mentioned problems can be solved, and the present invention has been completed.

That is, the present invention relates to the following (1) to (9). (1) A flame-retardant polybutylene terephthalate resin composition, characterized by containing a polybutylene terephthalate resin with a terminal carboxyl group content of 50 meq/kg or less, an alkaline metal inorganic compound, bromine Epoxy flame retardant and antimony trioxide are used, and the total content of epoxy groups in the entire composition is 0.010 mol/kg or more and 0.020 mol/kg or less. (2) The flame-retardant polybutylene terephthalate resin composition according to (1), wherein the basic metal inorganic compound is rhosite and/or talc. (3) The flame-retardant polybutylene terephthalate resin composition according to (1) or (2), wherein the basic metal is The content of the inorganic compound is 0.01 parts by mass or more and 25 parts by mass or less. (4) The flame-retardant polybutylene terephthalate resin composition according to (3), wherein the basic metal inorganic compound is, based on 100 parts by mass of the polybutylene terephthalate resin, Contains 0.01 parts by mass or more and less than 5.0 parts by mass of rhosite. (5) The flame-retardant polybutylene terephthalate resin composition according to (3), wherein the basic metal inorganic compound is, relative to 100 parts by mass of the polybutylene terephthalate resin, Contains 5.0 parts by mass or more and 25 parts by mass or less of talc. (6) A black foreign matter inhibitor consisting of the flame-retardant polybutylene terephthalate resin composition as described in any one of (1) to (5). (7) A method for suppressing black foreign matter using the flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (5). (9) A method for producing the flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (5). (9) A molded article obtained from the flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (5). [Effects of the invention]

According to the present invention, a polybutylene terephthalate resin composition containing a basic metal inorganic compound and excellent in flame retardancy can be provided.

[Form used to implement the invention]

Hereinafter, one embodiment of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with appropriate changes added within the scope that does not inhibit the effects of the present invention.

[Flame-retardant polybutylene terephthalate resin composition] Hereinafter, the details of each component of the flame-retardant polybutylene terephthalate resin composition of this embodiment will be described with examples.

(Polybutylene terephthalate resin) Polybutylene terephthalate resin (PBT resin ₎ contains at least terephthalic acid or its ester-forming derivatives ( _{C 1-6} alkyl ester, acid Halide, etc.) dicarboxylic acid component, and a glycol component containing at least a C4 alkylene glycol (1,4-butanediol) or its ester-forming derivatives (acetate, etc.) Polybutylene terephthalate resin obtained by polycondensation. In this embodiment, the polybutylene terephthalate resin is not limited to the homopolybutylene terephthalate resin, and may be a copolymer containing 60 mol% or more of butylene terephthalate units.

The amount of terminal carboxyl groups of the polybutylene terephthalate resin is 50 meq/kg or less, but it is not particularly limited as long as the object of the present invention is not hindered. However, it is preferably 30 meq/kg or less, and more preferably 25 meq/kg or less.

The inherent viscosity of the polybutylene terephthalate resin is not particularly limited as long as it does not hinder the object of the present invention, but it is preferably 0.60 dL/g or more and 1.2 dL/g or less, and more preferably 0.65 dL /g or more and 0.9dL/g or less. When a polybutylene terephthalate resin having an intrinsic viscosity in this range is used, the resulting polybutylene terephthalate resin composition is particularly excellent in moldability. In addition, the inherent viscosity can also be adjusted by blending polybutylene terephthalate resins with different intrinsic viscosities. For example, by blending a polybutylene terephthalate resin with an intrinsic viscosity of 1.0dL/g and a polybutylene terephthalate resin with an intrinsic viscosity of 0.7dL/g, a poly(butylene terephthalate) resin with an intrinsic viscosity of 0.9dL/g can be prepared. Butylene terephthalate resin. The intrinsic viscosity of polybutylene terephthalate resin can be measured in o-chlorophenol at a temperature of 35°C, for example.

In the preparation of polybutylene terephthalate resin, when aromatic dicarboxylic acids other than terephthalic acid or their ester-forming derivatives are used as comonomer components, for example, isophthalic acid, phthalic acid, or phthalic acid can be used. C _8-14 aromatic dicarboxylic _acids such as phthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4'-dicarboxydiphenyl ether; _succinic acid, adipic acid, azelaic acid, sebacic acid _{C 4-16} alkanedicarboxylic _acids such as acids; _{C 5-10} cycloalkanedicarboxylic acids such as cyclohexanedicarboxylic acid; ester _- forming derivatives of these dicarboxylic acid components ₍ alkyl groups of _{C 1-6} Ester derivatives, acid halides, etc.). These dicarboxylic acid components can be used alone or in combination of two or more types.

Among these dicarboxylic acid components, _{more preferred are C 8-12 aromatic} dicarboxylic acids such as isophthalic acid _{, and C 6-12 alkane dicarboxylates} such as adipic acid, azelaic acid, and sebacic acid _. acid.

In the preparation of polybutylene terephthalate resin, when a glycol component other than 1,4-butanediol is used as a comonomer component, for example, ethylene glycol, propylene glycol, 1,3-propylene glycol, C _2-10 alkylene glycols such as 1,3 _- butanediol, hexamethylene glycol _, neopentyl glycol, and 1,3-octanediol; diethylene glycol, triethylene glycol Alcohol, dipropylene glycol and other polyoxyalkylene glycols; cyclohexanedimethanol, hydrogenated bisphenol A and other alicyclic glycols; bisphenol A, 4,4'-dihydroxybiphenyl and other aromatic glycols; bis _{C 2-4} alkylene oxide adducts of bisphenol A such as the ethylene oxide 2 molar adduct of phenol A, the propylene oxide ₃ molar adduct of bisphenol A; or these diols Ester-forming derivatives (acetyl compounds, etc.). These glycol components can be used individually or in combination of 2 or more types.

Among these glycol components, C _{2 - 6} alkylene glycols such as ethylene glycol and 1,3-propanediol, polyoxyalkylene glycols such as diethylene glycol, or cyclohexane are more preferred. Alicyclic glycols such as dimethyl alcohol, etc.

Examples of comonomer components that can be used in addition to the dicarboxylic acid component and the glycol component include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 4-carboxy-4'- Aromatic hydroxycarboxylic acids such as hydroxybiphenyl; aliphatic hydroxycarboxylic acids such as glycolic acid and hydroxycaproic acid; C _{3 -} such as propiolactone, butyrolactone, valerolactone, caprolactone (epsilon-caprolactone, etc.) ₁₂ lactone; _{ester-forming derivatives of these comonomer components (C 1-6 alkyl ester} derivatives, acid halides, acetates, etc.).

The content of the polybutylene terephthalate resin is preferably 30 to 90 mass% of the total mass of the resin composition, more preferably 40 to 80 mass%, and still more preferably 50 to 70 mass%.

The epoxy compound that can be used in the brominated epoxy flame retardant of the present invention contains more than one epoxy group in one molecule. As the epoxy compound, from the viewpoint of improving thermal stability and hydrolysis resistance, an aromatic epoxy compound is preferably used. Examples of aromatic epoxy compounds include biphenyl-type epoxy compounds, bisphenol A-type epoxy compounds, novolak-type epoxy compounds, cresol novolak-type epoxy compounds, and the like. Moreover, as an epoxy compound, two or more compounds can also be used in combination arbitrarily.

The epoxy equivalent of the above-mentioned epoxy compound is preferably 30,000g/equivalent (g/eq) or more, more preferably 32,000g/eq or more, still more preferably 34,000g/eq or more, still more preferably 36,000g/eq or more, The best is 36,500g/eq or above. By setting the epoxy equivalent in this range, the appearance of the molded article obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be improved, and adhesion to the extruder during molding can be suppressed. , attachments to screws of molding machines, etc.

(Alkaline metal inorganic compound) As the basic metal inorganic compound contained in the flame-retardant polybutylene terephthalate resin composition of the present invention, layered silicate is preferred. As the layered silicate, talc, rhosite, etc. are preferred. Furthermore, as the basic metal inorganic compound contained in the flame-retardant polybutylene terephthalate resin composition of the present invention, a metal oxide is also preferred. As the metal oxide, magnesium oxide and zinc oxide are preferred.

In the polybutylene terephthalate resin composition of the present invention, it is preferable that the content of the basic metal inorganic compound is 0.01 mass part or more and 25 mass parts per 100 mass parts of polybutylene terephthalate resin. portion or less. Moreover, when rhosite is used as a basic metal inorganic compound, its content is preferably 0.01 parts by mass or more and less than 5.0 parts by mass relative to 100 parts by mass of polybutylene terephthalate resin. Furthermore, when talc is used as the basic metal inorganic compound, the content is preferably 5.0 parts by mass or more and 25 parts by mass or less based on 100 parts by mass of the polybutylene terephthalate resin.

(epoxy compound) The epoxy compound that can be used in the polybutylene terephthalate resin composition of the present invention contains more than one epoxy group in one molecule. As the epoxy compound, from the viewpoint of improving thermal stability and hydrolysis resistance, an aromatic epoxy compound is preferably used. Examples of aromatic epoxy compounds include biphenyl-type epoxy compounds, bisphenol A-type epoxy compounds, novolak-type epoxy compounds, cresol novolak-type epoxy compounds, and the like. Moreover, as an epoxy compound, two or more compounds can also be used in combination arbitrarily.

In the flame-retardant polybutylene terephthalate resin composition of the present invention, the total content of epoxy groups in the entire composition is 0.010 mol/kg or more and 0.020 mol/kg or less, but preferably 0.012 mol/kg. kg or more and 0.018 mol/kg or less, more preferably 0.014 mol/kg or more and 0.016 mol/kg or less. By setting the epoxy equivalent in this range, the appearance of the molded article obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be improved, and adhesion to the extruder during molding can be suppressed. , molding machines, etc. screw attachments. Furthermore, the hydrolysis resistance of the molded article obtained from the flame-retardant polybutylene terephthalate resin composition of the present invention can be improved.

(Flame retardant additive) The flame-retardant polybutylene terephthalate resin composition of the present invention preferably further contains a flame-retardant auxiliary agent. The flame retardant additive is not particularly limited, but is preferably a flame retardant additive selected from the group consisting of antimony trioxide, antimony pentoxide, and sodium antimonate.

(amorphous resin) The flame-retardant polybutylene terephthalate resin composition of the present invention preferably further contains an amorphous resin. By further containing an amorphous resin, warpage of a molded article obtained from the flame-retardant polybutylene terephthalate resin composition can be suppressed. As the amorphous resin, acrylonitrile-styrene copolymer resin is preferred.

(filler) In the flame-retardant polybutylene terephthalate resin composition of the present invention, a filler is used as necessary. In order to obtain excellent properties such as mechanical strength, heat resistance, dimensional stability, and electrical properties, it is preferable to blend such fillers, and it is particularly effective for the purpose of improving rigidity. Depending on the purpose, fibrous, powdery or plate-like fillers can be used.

Examples of fibrous fillers include glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and even Fibrous materials of stainless steel, aluminum, titanium, copper, brass and other metals. In addition, organic fibrous substances with high melting points such as polyamide, fluororesin, and acrylic resin can also be used.

Examples of powdery fillers include silicates such as carbon black, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, wollastonite, and iron oxide. , oxides of metals such as titanium oxide and aluminum oxide, carbonates of metals such as calcium carbonate and magnesium carbonate, sulfates of metals such as calcium sulfate and barium sulfate, silicon carbide, silicon nitride, boron nitride, and various metal powders wait.

Examples of plate-shaped inorganic fillers include mica, glass flakes, various metal foils, and the like.

The type of filler is not particularly limited, and one or more fillers may be added. In particular, it is preferable to use potassium titanate fiber, mica, talc, and wollastonite.

The amount of the filler added is not particularly defined, but is preferably 200 parts by mass or less based on 100 parts by mass of the polybutylene terephthalate resin. When the filler is added excessively, the formability is poor and the toughness is reduced.

(Additive) In addition, in the composition of the present invention, in order to provide desired characteristics other than flame retardancy, depending on the purpose, well-known substances generally added to thermoplastic resins and the like may be added and used together. For example, antioxidants, ultraviolet absorbers, stabilizers such as light stabilizers, antistatic agents, lubricants, release agents, colorants such as dyes or pigments, plasticizers, etc. can be optionally blended. Particularly effective is adding antioxidants that improve heat resistance.

[Black foreign matter inhibitor, black foreign matter suppression method] The flame-retardant polybutylene terephthalate resin composition of the present invention can be preferably used as a black foreign matter inhibitor. Furthermore, the flame-retardant polybutylene terephthalate resin composition of the present invention can be suitably used in a black foreign matter suppression method.

[Production method of flame-retardant polybutylene terephthalate resin composition] The flame-retardant polybutylene terephthalate resin composition of the present invention may be in the form of a powder-granule mixture or a molten mixture (melt-kneaded product) such as pellets. The method for producing the polybutylene terephthalate resin composition according to one embodiment of the present invention is not particularly limited, and can be produced using equipment and methods known in the technical field. For example, the necessary ingredients are mixed and kneaded using a single-screw or bi-screw extruder or other melt-kneading device to prepare pellets for molding. Extruders or other melting and kneading devices can also be used in plural. In addition, all the ingredients can be put in from the hopper at the same time, or part of the ingredients can be put in from the side feed port.

Furthermore, the flame-retardant polybutylene terephthalate resin composition of the present invention is preferably produced by vacuum drying (vacuuming). In vacuum drying, generally available evaporators, ovens, etc. can be used.

[Molded article obtained from flame-retardant polybutylene terephthalate resin composition] The flame-retardant polybutylene terephthalate resin composition of the present invention can be preferably used as, for example, relays, switches, connectors, actuators, sensors, transformer bobbins, and wiring. Segments, casings, switches, sockets, coils, plugs and other electrical and electronic components, especially used as power supply peripheral components. Furthermore, it is also suitable for use as a molding material for automotive component boxes such as ECU boxes and connector assemblies, and automotive components such as automotive power components.

The method for obtaining a molded article using this flame-retardant polybutylene terephthalate resin composition is not particularly limited, and a known method can be used. For example, the flame-retardant polybutylene terephthalate resin composition can be produced by putting the flame-retardant polybutylene terephthalate resin composition into an extruder, melting, kneading, and pelletizing it, then putting the pellets into an injection molding machine equipped with a designated mold, and performing injection molding. .

The above-mentioned molded product complies with the flammability UL94 standard and has a flammability of 0.8mmt, preferably V-0. The flammability of V-0 can be obtained by contacting the lower end of the vertical sample with the flame of the gas burner for 10 seconds. If the combustion stops within 30 seconds, contact the flame for another 10 seconds to satisfy the following standards. , and confirm. ． After any exposure to flame, no sample continued to burn for more than 10 seconds. ． The total burning time of 5 samples exposed to the flame 10 times shall not exceed 50 seconds. ． There is no sample that burns to the position of the clamp. ． There is no sample that causes the absorbent cotton placed under the sample to catch fire and cause burning particles to fall. ． There is no sample that continues to be heated for more than 30 seconds after being exposed to the flame for the second time.

(Example) Hereinafter, the present invention will be specifically described using examples. However, the present invention is not limited to the following examples as long as the gist is not exceeded.

(1) Flame retardancy The dry-blended materials with the ingredients and composition (parts by mass) shown in Table 1 were supplied to a twin-screw extruder (manufactured by Nippon Steel Works Co., Ltd.) with a screw of 30 mmϕ, and melted and kneaded at 260°C. The obtained polybutylene terephthalate resin composition pellets were dried at 140°C for 3 hours, and then injection molded at a cylinder temperature of 250°C and a mold temperature of 70°C to produce thicknesses of 1.6 mm and 0.8 mm in compliance with UL94. mm test pieces were used to evaluate the flammability, and those that satisfied V-0 were rated as "○" and those that did not were rated as "╳". The results are shown in Table 1.

(2) Stay in MI The melt flow rate (g/10 minutes) of the polybutylene terephthalate resin composition pellets obtained in the same manner as the evaluation of flame retardancy was determined in accordance with ISO1133-1 or ISO1133-2 at 260°C. , load 2.16kg, residence time 7 minutes, 15 minutes, 30 minutes, 45 minutes for measurement. The results are shown in Table 1.

(3) Screw attachments The pellets of the polybutylene terephthalate resin composition obtained in the same manner as the evaluation of flame retardancy were dried at 140° C. for 3 hours, and then melt-kneaded according to the following procedure, and the amount of black deposits was visually observed. The occurrence of attachments was marked as "╳", the occurrence of less attachments was marked as "△", the occurrence of few attachments was marked as "○", and the occurrence of attachments that were almost invisible was marked as "◎". The results are shown in Table 1. Process 1: Using LABO PLASTOMILL manufactured by Toyo Seiki Co., Ltd., the polybutylene terephthalate resin composition was extruded for 10 minutes at a cylinder temperature of 275°C and a screw rotation speed of 20 rpm. Process 2: Stop the screw directly at a cylinder temperature of 275°C, allowing the polybutylene terephthalate resin composition in the cylinder to remain for 120 minutes. Process 3: Set the cylinder temperature to 275°C and the screw rotation speed to 20 rpm, and rinse with the polybutylene terephthalate resin composition for 10 minutes. Process 4: Set the cylinder temperature to 275°C, screw rotation speed to 60 rpm, and rinse with polyethylene resin for 5 minutes. Process 5: Set the cylinder temperature to 200°C and the screw rotation speed to 60 rpm, and rinse with "Lioclean-Z" made by TOYOCOLOR Company for 5 minutes. Process 6: Remove the screw and wipe it gently with cotton flannel. After removing the flushing material, observe the amount of black attachments on the screw.

(4) Hydrolysis resistance The pellets of the polybutylene terephthalate resin composition obtained in the same manner as the evaluation of flame retardancy were dried at 140° C. for 3 hours, and then stretched at a cylinder temperature of 260° C. and a mold temperature of 90° C. according to ISO3167. The test piece for characteristic evaluation was injection molded and the tensile strength test was conducted in accordance with ISO527-1 and 2. Next, the above-mentioned test piece was subjected to moist heat treatment at 121°C and 2 atm (saturated water vapor pressure) for 150 hours, and a tensile strength test was performed in the same manner to determine the retention rate of the tensile strength before the moist heat treatment. The case where the tensile strength retention rate is 50% or more is designated as "◎", the case where the tensile strength retention rate is less than 50% and greater than 45% is designated as "○", and the case where the tensile strength retention rate is less than 45% and greater than 40% is designated as "△" , the case of less than 40% was regarded as "╳", and the hydrolysis resistance was evaluated. The results are shown in Table 1.

[Table 1]

The details of each component listed in Table 1 are as follows. PBT resin: Made by Wintech Polymer Co., Ltd., polybutylene terephthalate resin with a terminal carboxyl group concentration of 18 meq/kg and an inherent viscosity of 0.88 dL/g. AS resin: Made by Ningbo LG Yongxing Chemical Co., Ltd., AS RESIN 80HF Glass fiber: Made by Nippon Electric Glass Co., Ltd., ECS03T-127 (diameter 13μm, length 3mm) Brominated epoxy flame retardant 1: Brominated epoxy compound with an epoxy equivalent of 36800g/eq and a weight average molecular weight of approximately 18000 Brominated epoxy flame retardant 2: Brominated epoxy compound with epoxy equivalent of 19900g/eq and weight average molecular weight of approximately 23000 Antimony trioxide: manufactured by NIHON SEIKO Co., Ltd., PATOX-M PTFE (drip prevention agent): Polytetrafluoroethylene Bis-A type epoxy resin: Made by Mitsubishi Chemical Co., Ltd., jER 1004K (epoxy equivalent 925g/eq) Release agent: Neopentyl tetrastearate ("UNISTER H476" manufactured by NOF Co., Ltd.) Carbon black: Made by Mitsubishi Chemical Co., Ltd., MA600B Antioxidant: 4[methylene-3-(3,5-di-tertiary butyl-4-hydroxyphenyl)propionate]methane ("Irganox 1010" manufactured by BASF JAPAN Co., Ltd.) Basic compound 1: Rhodochrosite ("DHT-4A-2" manufactured by Kyowa Chemical Industry) Basic compound 2: Talc (manufactured by Lim Chemical Co., Ltd. "Talcum Powder PKNN") Basic compound 3: Potassium acetate ("Potassium Acetate Solution 60" manufactured by Daito Chemical Co., Ltd.) Basic compound 4: Magnesium oxide ("KYOWAMAG MF150" manufactured by Kyowa Chemical Industry Co., Ltd.) Basic compound 5: Zinc oxide (manufactured by Mitsui Metals & Mining Co., Ltd.) Basic compound 6: Carbodiimide compound ("Stabilizer 9000" manufactured by RASCHIG) In addition, although the carbodiimide compound does not qualify as a basic metal inorganic compound, it is described as basic compound 6 for convenience.

As shown in Table 1, the molded articles obtained from the flame-retardant polybutylene terephthalate resin compositions of Examples 1 to 13, which satisfy the constitution of claim 1 of this case, all have excellent appearance and no cracks are observed during molding. Attachment to the screw is obviously produced. Furthermore, no correlation between changes in retention MI and screw attachments was found.

On the other hand, the molded articles obtained from the polybutylene terephthalate resin compositions of Comparative Examples 1 to 5, which are outside the scope of claim 1 of this case, all had poor appearance and adhered to the screw during molding. things. Furthermore, the molded product obtained from the polybutylene terephthalate resin composition of Comparative Example 5 had poor hydrolysis resistance.

Furthermore, it can be seen from Examples 1 to 3 and 7 that when rhosite is added as an alkali compound, the added amount is 1.0 parts by mass or more relative to 100 parts by mass of polybutylene terephthalate resin. In the case where it is 2.5 parts by mass or less, it is advantageous in terms of suppressing adhesion to the screw, and in the case of 2.5 parts by mass or less, it is advantageous in terms of hydrolysis resistance.

Furthermore, it can be seen from Examples 4 to 6 that when talc is added as an alkali compound, the amount added is 10.0 parts by mass or more and 15.0 parts by mass or less based on 100 parts by mass of polybutylene terephthalate resin. , fully and balancedly improves the suppression of deposits on the screw and improves hydrolysis resistance.

without.

without.

Claims (5)

A black foreign matter inhibitor, which is composed of the following flame-retardant polybutylene terephthalate resin composition. The flame-retardant polybutylene terephthalate resin composition is characterized by containing: Polybutylene terephthalate resin with a terminal carboxyl group content of 50 meq/kg or less, a basic metal inorganic compound, a brominated epoxy flame retardant, and antimony trioxide, and the entire composition is The total content of epoxy groups is 0.010 mol/kg or more and 0.020 mol/kg or less, as a basic metal inorganic compound, including 0.01 mass part or more and less than 100 mass parts of polybutylene terephthalate resin. 5.0 parts by mass of rhosite. A black foreign matter inhibitor, which is composed of the following flame-retardant polybutylene terephthalate resin composition. The flame-retardant polybutylene terephthalate resin composition is characterized by containing: Polybutylene terephthalate resin with a terminal carboxyl group content of less than 50 meq/kg, basic metal inorganic compounds, brominated epoxy flame retardants, and antimony trioxide, and the epoxy group in the entire composition The total content is above 0.010mol/kg and below 0.020mol/kg, The basic metal inorganic compound contains 5.0 parts by mass or more and 25 parts by mass or less of talc based on 100 parts by mass of polybutylene terephthalate resin. A method for suppressing black foreign matter, which uses the black foreign matter inhibitor described in item 1 or 2 of the patent application scope. A method for manufacturing a black foreign matter inhibitor as described in item 1 or 2 of the patent application. A molded article obtained from the black foreign matter inhibitor described in Item 1 or 2 of the patent application.