JP2000038497A - Black polyester resin composition and its molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of reducing the decrease of insulation characteristics accompanied by the compounding of a carbon black, and useful as an insulation material by compounding a specific proportion of a polyolefin resin containing the carbon black in high concentration with a thermoplastic polyester resin. SOLUTION: This black polyester resin composition comprises (A) 100 pts.wt. thermoplastic polyester resin, (B) 0.1-50 pts.wt. polyolefin resin (preferably polyethylene resin or polypropylene resin) containing 5-60 wt.% carbon black. The composition preferably further includes 5-80 pts.wt. filler and/or reinforcing material (preferably muscovite) based on 100 pts.wt. component A. When preparing the composition, a homogeneous black masterbatch is required to be previously prepared by melting and kneading the polyolefin resin with the carbon black, and the masterbatch is preferably melted and kneaded with the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black polyester resin composition and a molded product thereof.
An object of the present invention is to provide a black thermoplastic polyester resin composition and a molded article thereof suitable for producing a molded article such as an insulating part of an electronic device.

[0002]

2. Description of the Related Art Conventionally, thermoplastic polyester resins are excellent in insulation and chemical resistance and have little change in electric characteristics due to moisture absorption, and are suitable for producing molded articles such as insulating parts of electric and electronic equipment. Used in Further, in electric and electronic applications, resin parts are often colored black, and the resin is colored by adding carbon black. However, although carbon black coloring by the conventional method is robust and inexpensive, it has been known that the resin moldings deteriorate insulation properties such as dielectric breakdown voltage, tracking resistance and withstand voltage life. Although organic dyes and pigments are also used instead of carbon black, they are inferior to carbon black in terms of the color tone of the molded product and the discoloration due to high temperature, ultraviolet rays, and the like.

[0003] It is common practice to mix a masterbatch in which carbon black or another coloring agent is previously filled into a resin at a high concentration with a resin to be colored. However, in order to ensure the dispersibility of the colorant, the resin of the master batch and the resin to be colored are generally the same. That is, it is common to use a polyester resin for the masterbatch for the polyester resin composition. It is not known to blend a carbon black polyolefin resin masterbatch into a polyester resin composition to improve insulation properties.

[0004]

The present invention makes it possible to reduce the decrease in insulation properties due to black coloring by blending carbon black.
It has been strongly desired to provide a polyester resin composition and a molded article thereof.

[0005]

A polyolefin resin containing carbon black at a high concentration, prepared by melt-kneading carbon black with a polyolefin resin, is blended with a thermoplastic polyester resin in a predetermined ratio.
The present inventors have found that a decrease in insulation properties due to the addition of carbon black can be reduced, and have reached the present invention.

That is, in the present invention, a thermoplastic polyester resin is blended with a polyolefin resin containing 5 to 60% by weight of carbon black at a ratio of 0.2 to 50 parts by weight based on 100 parts by weight of the polyester resin. A black polyester resin composition characterized in that:

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the thermoplastic polyester resin in the present invention, a known aromatic polyester resin can be used. The aromatic polyester resin is not particularly limited as long as it is a polyester having an aromatic ring in a chain unit of a polymer. Usually, an aromatic dicarboxylic acid and a diol (and their ester-forming derivatives) are used as main raw materials for polycondensation. A polymer or copolymer obtained by the reaction is used.

The aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid,
2,6-naphthalenedicarboxylic acid, biphenyl-2,
2'-dicarboxylic acid, biphenyl-3,3'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, diphenylether-4,4'-dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-
4,4'-dicarboxylic acid, diphenylisopropylidene-4,4'-dicarboxylic acid, 1,2-bis (phenoxy) ethane-4,4'-dicarboxylic acid, anthracene-
Examples thereof include 2,5-dicarboxylic acid, anthracene-2,6-dicarboxylic acid, p-terphenylene-4,4′-dicarboxylic acid, and pyridine-2,5-dicarboxylic acid, and preferably terephthalic acid. Two or more of these aromatic dicarboxylic acids may be used in combination. In addition, if it is a small amount, one or more kinds of aliphatic dicarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid and sebacic acid can be used in combination with these aromatic dicarboxylic acids.

As the diol, ethylene glycol,
Aliphatic diols such as propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methylpropane-1,3-diol, diethylene glycol and triethylene glycol, and cyclohexane-1,4-dimethanol And the like, preferably butylene glycol.
These diols may be used in combination of two or more. In addition, if it is a small amount, even if one or more kinds of long-chain diol diols having a molecular weight of 400 to 6000, that is, polyethylene glycol, poly-1,3-propylene glycol, polytetramethylene glycol or the like are used in combination with these diols Good.

Specific examples of the aromatic polyester resin include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene-1,2-bis (phenoxy) ethane-4,4'-.
Examples thereof include dicarboxylate and polycyclohexanedimethanol terephthalate, and preferably include polybutylene terephthalate. Also, polyethylene isophthalate / terephthalate, polybutylene isophthalate / terephthalate, polybutylene isophthalate /
Copolyesters such as decane dicarboxylate can also be used.

As the aromatic polyester resin, for example, polybutylene terephthalate resin has an intrinsic viscosity of 0.1.
5 to 1.6 are preferred, and more preferably 0.6 to
1.3. The intrinsic viscosity is 1,1,
It is measured at 30 ° C. using an Ubbelohde viscometer using an equal weight mixture of 2,2-tetracurluethane and phenol. Those having an intrinsic viscosity of 0.5 or less have insufficient practical strength, and those having an intrinsic viscosity of 1.6 or more have insufficient fluidity during molding.

As the polyolefin resin in the present invention, a homopolymer or copolymer composed of at least one kind of α-olefin having 2 to 20 carbon atoms or a modified product thereof is used.

The α-olefin forming the polyolefin resin includes ethylene, propylene, butene-
1, pentene-1, hexene-1, 3-methylbutene-
1,4-methylpentene-1,3,3-dimethylpentene-1,3-methylhexene-1,4-methylhexene-1,4,4-dimethylhexene-1,5-methylhexene-1, allylcyclo Pentane, allylcyclohexane, allylbenzene, 3-cyclohexylbutene-1,
Examples thereof include vinylcyclopropane, vinylcyclohexane, 2-vinylbicyclo [2.2.1] heptane, heptene-1 and octene-1. One or more of these α-olefins can be used as a polymerization component.

Preferred examples of the α-olefin include ethylene, propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and 3-methylhexene-1. And particularly preferred are ethylene and propylene. Further, as other components, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 5-methyl-
Non-conjugated dienes such as 1,4 hexadiene, 7-methyl-1,6 octadiene and 1,9-decadiene may be used as a part of the polymerization component.

Specific examples of the polyolefin resin include a homopolymer of ethylene or a random or block copolymer containing ethylene as a main component and one or more of the above α-olefins and / or other components other than ethylene. Polyethylene resin, a propylene homopolymer or a polypropylene resin which is a random or block copolymer containing propylene as a main component and one or more of the above-mentioned α-olefins and / or other components other than propylene; Examples thereof include a polybutene resin, a polypentene resin, and a polyhexene resin, which are a homopolymer of an olefin or a copolymer containing the same as a main component, and preferably a polyethylene resin or a polypropylene resin.

The polyolefin resin is a modified product of the above-mentioned various polyolefin resins, as long as it does not impair the physical properties such as fluidity and flame retardancy as well as the insulating properties aimed at by the present invention. It may be a polyolefin resin. Actually, a modified polyolefin resin containing a functional group such as a carboxylic acid group, an acid anhydride group, an epoxy group, an oxazolinyl group, an acid imide group, or a hydroxyl group is used depending on the purpose of the modification.

As the polyolefin resin, a crystalline resin is selected, and the crystallinity at room temperature by X-ray diffraction is 10%.
It is preferably at least 20%, more preferably at least 20%. The melting point is preferably 40 ° C. or higher. When the molecular weight is polyethylene resin or polypropylene resin, the test temperature is 190 in accordance with JIS K7210.
The melt flow rate (hereinafter referred to as MFR) measured at a temperature of 2.degree.
Those having a molecular weight corresponding to 10 minutes, preferably 0.05 to 100 g / 10 minutes are preferred. If the MFR is outside this range, the dispersion of the polyolefin resin in the thermoplastic polyester resin is poor, and a good black appearance cannot be obtained.

In the present invention, the polyolefin resin to be blended with the thermoplastic polyester resin is prepared in advance as a composition containing carbon black at a predetermined ratio, so-called masterbatch. The carbon black content in the carbon black masterbatch must be 5% by weight or more and 60% by weight or less, preferably 15% by weight or more and 45% by weight or less. If the content of carbon black is less than 5% by weight, the amount of the masterbatch added increases to obtain a sufficient degree of blackness, and a good black appearance cannot be obtained. If the content of carbon black exceeds 60% by weight, it becomes difficult to produce a master batch. The amount of the carbon black masterbatch is usually 0.1 to 50 parts by weight, preferably 0.2 to 50 parts by weight, based on 100 parts by weight of the thermoplastic polyester resin.
It is 30 parts by weight, more preferably 0.3 to 20 parts by weight. If the masterbatch content is less than 0.1 part by weight,
It is difficult to obtain a sufficient black color, and if it exceeds 50 parts by weight, the characteristics are apt to deteriorate.

Various fillers and reinforcing materials can be added to the black polyester resin composition of the present invention according to the purpose. The shape of the filler and the reinforcing material may be any of a fiber shape, a plate shape, a flake shape, a powder shape, and the like. Specific examples of fillers and reinforcing materials include mica, glass fiber,
Glass flakes, glass beads, silica, alumina, titanium oxide, calcium sulfate powder, gypsum, gypsum whiskers, barium sulfate, talc, asbestos, calcium silicate, zinc borate, silicon carbide, silicon carbide fiber, silicon nitride, silicon nitride fiber, Potassium titanate fibers, whiskers, aromatic polyamide fibers and the like can be mentioned. These fillers and reinforcing materials may be surface-treated with a silane coupling agent, a titanium-based coupling agent, or the like, or may be treated with a sizing agent as long as the insulating properties are not impaired.
Fillers and / or reinforcements include mica and glass fibers.

The compounding ratio of the filler and / or the reinforcing material is preferably 5 to 80 parts by weight, more preferably 10 to 70 parts by weight, based on 100 parts by weight of the polyester resin. Examples of mica include muscovite, phlogopite, biotite, artificial mica, and the like. Mica having a small content of iron oxide is desirable, and use of muscovite is particularly desirable. The particle size of the mica is preferably 40 μm in view of the dielectric breakdown voltage and the withstand voltage life.
Or less, more preferably 25 μm or less. Here, the particle size is an average particle size measured by a microtrack laser diffraction method.

The resin composition of the present invention may further comprise a flame retardant, a flame retardant auxiliary, various resin components other than polyester resin such as PTFE and polyolefin resin, various elastomer components, a heat stabilizer, an antioxidant, according to the purpose. Various additives such as an agent, a weathering agent, a lubricant, a release agent, a crystal nucleating agent, a plasticizer, and an antistatic agent can also be blended.

The compounding method for producing the resin composition of the present invention is not particularly limited as long as it is a method conventionally applied to a polyolefin resin composition and a polyester resin composition, and a usual method can be used. For example, a method using a device that can melt or knead the compounded components batchwise or continuously can be used, and examples of the device include an extruder.

However, in the production of the resin composition of the present invention, it is necessary to prepare a homogeneous black master batch by melt-kneading a polyolefin resin and carbon black in advance as a compounding sequence. Next, the master batch is melt-kneaded with a thermoplastic polyester resin to obtain a black polyester resin composition of the present invention.

The method for producing a molded article from the resin composition of the present invention is not particularly limited, and an ordinary molding method can be used.
For example, an injection molding method, an extrusion molding method and the like can be mentioned.

The molded article made of the resin composition of the present invention can be used as an insulator for various electric and electronic devices.
Examples include electrical components such as ignition coils and distributors, transformers, and other applications that require a high withstand voltage life and high dielectric breakdown voltage due to the high voltage applied.
Applications where tracking resistance is required, such as insulators and relays, are applications suitable for this molded article.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

In the examples and comparative examples, the following raw materials were used. (1) Thermoplastic polyester resin: Polybutylene terephthalate NOVA manufactured by Mitsubishi Engineering-Plastics Corporation
DUR5007A intrinsic viscosity 0.75 (hereinafter abbreviated as “PBT”). (2) Flame retardant: pentabromobenzyl polyacrylate (3) Flame retardant auxiliary: sodium antimonate (4) Heat stabilizer: pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-) (Hydroxyphenyl) propionate] (5) Release agent: Paraffin wax (6) Glass fiber: Chopped strand having a diameter of 13 μm and a length of 3 mm (7) Muscovite: A-21B (Yamaguchi Mica Co., Ltd.) (particle size: 21 μm) (8) Carbon black master batch PEM8080 (carbon black / polyethylene = 40/60) manufactured by Sumika Color Co., Ltd. PT2 manufactured by Mitsubishi Engineering-Plastics Corporation
0BL (carbon black / PBT = 20/80)

The insulation properties in the examples and comparative examples are as follows:
The measurement was performed by the following three methods. (1) Tracking resistance Apparatus: Tracking test apparatus HAT-500-1 manufactured by Hitachi Chemical Co., Ltd. Specimen shape: 100 mm × 100 mm × 3 mm Measurement conditions: UL746A / ASTM D3638 Result notation: Comparative tracking of the above UL standard It was described based on (PLC) for the index (CTI). (2) Breakdown voltage Apparatus: Tama Denso Co., Ltd. Breakdown strength measuring apparatus TH-7050AP Specimen shape: 100 mm × 100 mm × 1 mm Measurement conditions: Breakdown voltage test Measured according to JIS C2110 Short-time breakdown test Electrode in oil φ20 mm sphere / φ25 mm cylinder Result notation: Expressed in terms of voltage (kV) at which dielectric breakdown occurred. (3) Withstand voltage life device: Hitachi Chemical Co., Ltd. Long-term electrification / deterioration tester HAT-620 Specimen shape: 100 mm x 100 mm x 1 mm Measurement conditions: proprietary standards Long-term electrification / deterioration test Electrode shape in air 20 mm sphere / φ25 mm cylinder Voltage 15 kV Frequency 700 Hz Temperature 120 ° C. Result notation: Expressed in time until dielectric breakdown occurs.

Example 1 100 parts by weight of PBT, 16 parts by weight of a flame retardant, 18 parts by weight of a flame retardant aid, 1 part by weight of a heat stabilizer, 0.6 part by weight of a release agent, carbon black / polyethylene master batch 2 Parts by weight, and using a twin-screw extruder (screw diameter 35 mm, L / D = 26), kneading while adding 59 parts by weight of glass fiber from a side feeder at a barrel setting temperature of 250 ° C. and a rotation speed of 200 rpm, A black polyester resin composition pellet was obtained. Test pieces for measuring various insulating properties were molded from the obtained pellets at a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. by a screw in-line injection molding machine, and were used for evaluation. Table 1 shows the results.

Comparative Example 1 Pellets and test pieces were obtained in the same manner as in Example 1 except that 4 parts by weight of the carbon black / polyester master batch was used instead of the carbon black / polyethylene master batch of Example 1. . The amount of the masterbatch is different in order to make the carbon black concentration in the composition the same as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 2 Pellets and test pieces were obtained in the same manner as in Example 1 except that the carbon black / polyethylene master batch of Example 1 was not added. The evaluation results are shown in Table 1.

[0032]

[Table 1]

Example 2 44 parts by weight of muscovite powder having a particle size of 21 μm, 0.4 part by weight of a heat stabilizer, 0.4 part by weight of a release agent, 100 parts by weight of PBT, carbon black / polyethylene masterbatch 0.1 part by weight. 7 parts by weight were blended and kneaded using a single screw extruder (screw diameter 35 mm, L / D = 32) at a barrel setting temperature of 250 ° C. and a rotation speed of 200 rpm,
A pellet was obtained. Test pieces for measuring various insulating properties were molded from the obtained pellets at a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C. by a screw in-line injection molding machine, and were used for evaluation. Table 2 shows the results.

Comparative Example 3 Pellets and test pieces were obtained in the same manner as in Example 2 except that 1.4 parts by weight of the carbon black / polyester master batch was used instead of the carbon black / polyethylene master batch of Example 2. . Table 2 shows the evaluation results.

Comparative Example 4 Example 2 except that the carbon black / polyolefin masterbatch was not blended.
A pellet and a test piece were obtained in the same manner as described above. Table 2 shows the evaluation results.

[0036]

[Table 2]

[0037]

According to the present invention, a black polyester resin composition having excellent insulating properties can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Muramatsu 5-6-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Inside the Technology Center of Mitsubishi Engineering Plastics Co., Ltd. (72) Yoshitaka Kanazawa 5-chome, Higashi-Yawata, Hiratsuka-shi, Kanagawa No. 6-2 Mitsubishi Engineering Plastics Co., Ltd. Technology Center (72) Inventor Osamu Takise 5-6-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture F-term in Mitsubishi Engineering Plastics Co., Ltd. Technical Center 4J002 BB032 BB052 BB122 BB142 BB172 CF051 CF061 CF071 CF081 DA036 DE137 DE147 DG047 DG057 DJ007 DJ017 DJ027 DJ047 DJ057 DK007 DL007 FA047 FD017 GQ01

Claims (6)

[Claims] 1. A thermoplastic polyester resin containing a polyolefin resin containing 5 to 60% by weight of carbon black in an amount of 0.1 to 100 parts by weight of the polyester resin.
A black polyester resin composition which is blended at a ratio of 50 parts by weight. 2. The black polyester resin composition according to claim 1, wherein the polyolefin resin is a polyethylene resin or a polypropylene resin. 3. The black polyester resin composition according to claim 1, wherein the filler and / or the reinforcing material are blended in an amount of 5 to 80 parts by weight based on 100 parts by weight of the polyester resin. 4. The black polyester resin molded product according to claim 3, wherein the filler and / or the reinforcing material is mica or glass fiber. 5. The black polyester resin molded product according to claim 3, wherein the filler and / or the reinforcing material is muscovite. 6. A molded article comprising the black polyester resin composition according to any one of claims 1 to 5.