JPH0657110A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To suppress the decrease in tracking resistance of a polyester resin caused by the addition of a specific colorant while maintaining the excellent properties inherent in the resin. CONSTITUTION:This resin composition comprises a polyester resin and a modified colorant pretreated with a thermoplastic elastomer and/or a polyolefin. The decrease of the tracking resistance of the resin by the addition of the colorant can be minimized by this pretreatment of the colorant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition using a modified colorant which has been subjected to a specific treatment, and relates to a polyester resin molding material exhibiting excellent tracking resistance.

[0002]

2. Description of the Related Art Polyester resins represented by polyethylene terephthalate (hereinafter abbreviated as PET) and polybutylene terephthalate (hereinafter abbreviated as PBT) are strength, toughness, chemical resistance, and electrical insulation. It is widely used as an engineering plastic for electric / electronic parts, automobile parts, mechanical parts, etc.
It is used as a material for various electrical parts such as relay cases, capacitor cases, transformer bobbins, and connectors, taking advantage of its excellent electrical characteristics. However, the excellent electrical properties originally possessed by the polyester resin may sometimes be significantly deteriorated by the function-imparting agent added for another purpose. For example, it is known that a certain kind of metal oxide used as a colorant or carbon, which is a black colorant, in particular, significantly reduces the tracking resistance when added in a trace amount. The present inventors have arrived at the present invention as a result of extensive studies aimed at reducing the influence of the coloring agent used in the polyester resin on the reduction in tracking resistance as much as possible.

[0003]

OBJECTS OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to prevent the deterioration of tracking resistance caused by the addition of a specific colorant while maintaining the excellent properties of a polyester resin. There is a point to blame.

[0004]

The present inventor has conducted intensive studies to minimize the influence of the coloring agent used in the polyester resin on the deterioration of tracking resistance, and as a result, treated the coloring agent with a thermoplastic elastomer and / or a polyolefin in advance. The inventors have found that the modified colorant thus obtained meets the above-mentioned object, and arrived at the present invention.

That is, the polyester resin composition of the present invention is a polyester resin composition obtained by blending the polyester resin (X) with a modified colorant (Y) pretreated with a thermoplastic elastomer and / or a polyolefin. The present invention is described in detail below.

The polyester resin as the component (X) used in the present invention is terephthalic acid or 2,6-naphthalenedicarboxylic acid or an ester-forming derivative thereof as a main acid component, and has 2 to 2 carbon atoms as a main glycol component. A linear saturated polyester obtained by using the glycol of 10 or an ester moldable derivative thereof, for example, polyethylene terephthalate (PET),
Examples thereof include polypropylene terephthalate, polybutylene terephthalate (PBT), polyhexamethylene terephthalate, polycyclohexane 1,4-dimethylene terephthalate, polybutylene 2,6-naphthalene dicarboxylate (PBN) and the like. PE among these
T, PBT and PBN are preferred.

The term "mainly" as used herein means 80 mol% or more, preferably 90 mol% or more, based on all acid components or all glycol components. These polyesters may be used alone or as a mixed system of two or more kinds.

Further, a part of the acid component or the glycol component may be replaced with another copolymerization component. Such copolymerizable acid components include terephthalic acid and 2,6-
Aromatic dicarboxylic acids other than naphthalene dicarboxylic acid, such as isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid,
Diphenoxyethane dicarboxylic acid, diphenyl ketone dicarboxylic acid, diphenyl sulfone dicarboxylic acid, etc., aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, etc., alicyclic dicarboxylic acid such as cyclohexane dicarboxylic acid, tetralin dicarboxylic acid, decalin dicarboxylic acid Examples thereof include acids. Examples of the copolymerizable glycol component other than the glycol having 2 to 10 carbon atoms include tricyclodecane dimethylol, bisphenol A, bisphenol B, bishydroxyethoxy bisphenol A and the like.

Further, a polyfunctional compound such as glycerin, etc., within a range in which the polyester resin does not substantially lose molding performance.
Trimethylolpropane, pentaerythritol, trimellitic acid, pyromellitic acid and the like may be copolymerized.

The "modified colorant" pretreated with the thermoplastic elastomer and / or polyflaffin which is the component (Y) of the present invention means the target colorant and the thermoplastic elastomer and / or polyolefin. It is obtained by uniformly kneading the thermoplastic elastomer and / or polyolefin at a temperature equal to or higher than the melting point or softening point of the polyolefin and then granulating the mixture. A kneader, a Banbury mixer, a roll, an extruder or the like can be used for kneading in the production method of these modified colorants. The colorant referred to here is a colorant generally used for coloring a polyester resin. In particular, carbon black generally used as a black colorant is known to significantly reduce the tracking resistance of the polyester resin, but the improvement effect of the present invention is remarkable.

The polyester elastomer constituting all or part of the component (Y) of the present invention is formed by reacting a polyalkylene oxide as one component with a dicarboxylic acid component and, if necessary, a glycol component in combination. be able to.

The polyalkylene oxide mentioned here is a polymer composed of alkylene oxide units having 2 to 4 carbon atoms, and examples of the alkylene group include ethylene, trimethylene, and tetramethylene groups.
Specific examples of the polyalkylene oxide include poly (ethylene oxide), poly (propylene oxide), and poly (tetramethylene oxide). The polyalkylene oxide has a molecular weight of 200 or more, preferably 5
It is at least 00, and examples thereof include poly (ethylene oxide) having a molecular weight of 1000 and poly (tetramethylene oxide) having a molecular weight of 1000.

Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 1,
4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid and the like can be mentioned. Examples of the glycol component include ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol and the like. Such polyester elastomer is 500
It is preferable to have the above molecular weight.

The polyolefin constituting a part or all of the component (Y) of the present invention means ethylene, propylene,
A polymer produced by an ordinary method using olefins such as butene-1 and pentene-1 as monomers is targeted. These olefins may be used alone or in admixture of two or more. Further, if necessary, copolymerization with other monomers having 10% by weight or less of double bond is possible. Examples of these copolymerizable monomers include vinyl acetate, isoprene, chloropyrene, butadiene and the like, monocarboxylic acids such as acrylic acid and methacrylic acid, or derivatives thereof such as acid anhydrides and glycidyl esters, maleic acid, fumaric acid and itacone. Examples thereof include dicarboxylic acids such as acids and acid anhydrides thereof. The most preferred of these polyolefins are polyethylene and polypropylene.

In the method for producing the modified colorant, the compounding ratio of the colorant and the thermoplastic elastomer and / or the polyolefin must be 50 parts by weight or more per 100 parts by weight of the colorant. . When this ratio is less than 50 parts by weight, the effect of suppressing the deterioration of tracking resistance, which is the improvement effect of the present invention, is small. On the other hand, the upper limit of the blending ratio of the thermoplastic elastomer and / or the polyolefin is not particularly limited in terms of the effect of suppressing the deterioration of the tracking resistance,
It is not preferable to use an extremely large blending ratio, since the excellent properties such as heat resistance and fluidity inherent in the polyester resin may be impaired. Therefore, the blending ratio should be determined in consideration of workability in producing the modified colorant, economical efficiency, characteristic influence on the polyester resin, and the like, and is usually preferably 100 to 1000 parts by weight.

In the present invention, the blending amount of the modified colorant of the component (Y) with respect to the polyester resin of the component (X) is a required color expression amount and is not particularly limited.

If desired, the polyester resin composition of the present invention may contain other additives such as stabilizers, colorants, ultraviolet absorbers, mold release agents, antistatic agents, and crystallizations, so long as the characteristics are not significantly impaired. Accelerators, crystalline nucleic acids, fillers, impact modifiers, flame retardants and the like can be added.

Any compounding method can be used to obtain the resin composition of the present invention. Usually, it is preferable to disperse these blending components more uniformly, and all or part of them may be simultaneously or separately blended, for example, a blender,
A method of mixing and homogenizing with a mixer such as a kneader, a Banbury mixer, a roll, an extruder, or a part of the mixing portion is mixed simultaneously or separately with, for example, a blender, a kneader, a mixer, a roll, an extruder, etc., and the rest is left. It is possible to use a method of mixing the components of (1) with these mixers or extruders and homogenizing. Further, there is a method in which a composition dry-blended in advance is melt-kneaded with a heated extruder to homogenize it, then extruded into a wire shape, and then cut into a desired length and granulated.

The resin composition obtained by the present invention can be molded very easily by a usual method using a general thermoplastic resin molding machine.

[0020]

EXAMPLES The present invention will be described in detail below with reference to examples. In addition,
Various properties in the examples were measured by the following methods. (1) Mechanical strength: ・ Tensile test …… Complies with ASTM D638.・ Impact test (1/8 "thickness, with Izod notch)
...... Compliant with ASTM D256. As the test piece for measurement, a molded article conforming to the ASTM test was used. (2) Tracking resistance test-IEC Publ. 112 (Third Edition) -1979
Complies with.

Using test solution A (ammonium chloride).・ Displayed as comparative tracking index (CTI). As the measurement test piece, a disk molded product having a diameter of 50 mm and a thickness of 3 mm was used. Method for producing modified colorant Various colorants described in Table 1 and a thermoplastic elastomer and / or a polyolefin as a treating agent are uniformly mixed in a tumbler in a predetermined amount ratio, and then twin screw with a vent having a screw diameter of 44 mm. Cylinder temperature 210 ° C, screw rotation speed 64r while evacuating using an extruder
It was melt-kneaded at pm and a discharge rate of 40 kg / h, and the thread discharged from the die was cooled and cut to obtain a molding pellet.

The following various coloring agents and treating agents shown in Table 1 were used. CB-1 ... Carbon black MA6 manufactured by Mitsubishi Kasei Co., Ltd.
00B CB-2 ... Carbon black manufactured by Denki Kagaku Kogyo Co., Ltd.
Denka Carbon HY ... DuPont Co., Ltd. Polyether / Ester Elastomer Hytrel 4056 PE ... Mitsui Petrochemical Co., Ltd. Polyethylene Hyzex Million 145M PP ... Mitsui Toatsu Chemical Co., Ltd. Polypropylene Noblene JS-G

[0023]

[Table 1]

[0024]

[Examples 1 to 7 and Comparative Examples 1 to 10] Various raw materials shown in Table 2 were mixed in advance in a predetermined amount in a tumbler, and then evacuated to a vacuum using a vented single-screw extruder having a screw diameter of 68 mm. On the other hand, a cylinder temperature of 280 ° C., a screw rotation speed of 64 rpm, and a discharge rate of 55 kg / h were melt-kneaded, and a thread discharged from a die was cooled and cut to obtain a molding pellet.

Next, using this pellet, an injection volume of 5
Injection pressure 800kg / cm ^{2 with} ounce injection molding machine,
Test pieces for strength measurement and tracking resistance measurement were molded under the conditions of a cooling time of 15 seconds and a total molding cycle of 40 seconds and used for measurement.

The results of these tests are shown in Table 2.

[0027]

[Table 2]

The following various raw materials shown in Table 2 were used. PET: PET TR8550 PBT manufactured by Teijin Ltd. PBT TRB-J PBN manufactured by Teijin Limited PBN C8000 glass fiber manufactured by Teijin Ltd. 3PE474 release agent manufactured by Nitto Boseki Co., Ltd. Hoechst WAX manufactured by Hoechst Co., Ltd. -E talc ... PKNN manufactured by Hayashi Kasei Co., Ltd. As is clear from the results in Table 2, the addition of the coloring agent alone reduces the tracking resistance as compared with the case where no coloring agent is added, but the modified coloring agent according to the present invention is used. And the deterioration of the tracking resistance is remarkably improved.

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Claims (5)

[Claims] 1. A polyester resin composition comprising a polyester resin and a modified colorant pretreated with a thermoplastic elastomer and / or a polyolefin. 2. The polyester resin composition according to claim 1, wherein the polyester resin is a polybutylene terephthalate resin. 3. The polyester resin composition according to claim 1, wherein the polyester resin is a polyethylene terephthalate resin. 4. The polyester resin composition according to claim 1, wherein the polyester resin is polybutylene naphthalene dicarboxylate. 5. The polyester resin composition according to claim 1, wherein the colorant is mainly composed of carbon black.