JPH0657108A - Polyester resin composition - Google Patents

Abstract

(57) [Summary] [Purpose] By blending two specific types of polymers in a specific amount in a polyester resin, it is possible to achieve a significant improvement in tracking resistance that cannot be achieved by blending them individually. [Structure] A polyester resin composition comprising 1 to 30 parts by weight of a thermoplastic elastomer and 1 to 30 parts by weight of a polyolefin per 100 parts by weight of a polyester resin, and by blending two kinds of specific polymers together in a specific amount, It has the effect of significantly improving tracking resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the development of a polyester resin molding material exhibiting excellent tracking resistance by mixing at least two specific polymers in specific amounts in a polyester resin.

[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 tracking resistance of these polyester resins is not limited to other resins, for example, polyolefins such as polyethylene and polypropylene, polyamides such as nylon 6 and nylon 66, thermosetting resins such as unsaturated polyester, fluororesin and melamine resin. It is hard to say that it is always superior when compared to the above. Further, it is known that when glass fiber, a certain colorant, and other additives are blended for the purpose of improving other properties of these polyester resins, the tracking resistance thereof is further lowered. In many cases, it is not used as a component material because of its poor tracking resistance, even though it is expected to utilize its useful properties.

The inventor of the present invention arrived at the present invention as a result of extensive studies to improve the essential defects of the polyester resin.

[0004]

OBJECTS OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to improve tracking resistance while keeping the excellent properties of polyester resin as much as possible.

[0005]

The present inventor has conducted extensive studies to improve the tracking resistance of a polyester resin, and as a result, found that the above-mentioned object can be met by combining at least two kinds of specific polymers in specific amounts. The present invention has been reached. That is, the polyester resin composition of the present invention is (B) per 100 parts by weight of (A) polyester resin.
1-30 parts by weight of thermoplastic elastomer and (C)
A polyester resin composition comprising 1 to 30 parts by weight of a polyolefin. The present invention is described in detail below.

The component (A) polyester resin 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 a carbon number of 2 to 2 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 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 thermoplastic elastomer which is the component (B) of the present invention comprises a polyalkylene oxide as one component.
It can be produced by combining this with a dicarboxylic acid component and, if necessary, a glycol component and reacting.

The polyalkylene oxide as used herein is a polymer composed of an alkylene oxide unit 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 blending amount of these polyester elastomers is 1 to 30 parts by weight per 100 parts by weight of the polyester resin. When the compounding amount is less than 1 part by weight, the effect of improving the tracking resistance, which is the improving effect of the present invention, is small. On the other hand, when the amount is more than 30 parts by weight, the polyester resin has excellent heat resistance and fluidity. Such characteristics are not preferable because they are not preferable.

The polyolefin constituting the component (C) of the present invention is a polymer produced by a conventional method using olefins such as ethylene, propylene, butene-1 and pentene-1 as monomers. 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.

The amount of these polyolefins added is 1 to 30 parts by weight per 100 parts by weight of the polyester resin. When the compounding amount is less than 1 part by weight, the effect of improving the tracking resistance, which is the improving effect of the present invention, is small. On the other hand, when the amount is more than 30 parts by weight, the polyester resin has excellent heat resistance and fluidity. Such characteristics are not preferable because they are not preferable.

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.

[0019]

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.

[0021]

Examples 1 to 4 and Comparative Examples 1 to 7 Various raw materials shown in Table 1 were uniformly mixed in a tumbler in a predetermined amount ratio, and then evacuated to a vacuum using a vented single-screw extruder having a screw diameter of 68 mm. While the temperature of the cylinder is 280 ° C., the screw rotation speed is 64 rpm, and the discharge rate is 55 kg / h.
The thread discharged from the die was cooled and cut to obtain pellets for molding.

Using the pellets, an injection molding machine having an injection capacity of 5 ounces was subjected to tests for strength measurement and tracking resistance measurement under the conditions of an injection pressure of 800 kg / cm ² , a cooling time of 15 seconds, and a total molding cycle of 40 seconds. The piece was molded and subjected to measurement.

As the various raw materials shown in Table 1, the following materials 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 HY manufactured by Hayashi Kasei Co., Ltd .... DuPont Co., Ltd. polyether / ester elastomer Hytrel 4056 PE-1 ... Mitsui Petrochemical Co., Ltd. polyethylene Hyzex Million 145M PE-2 ... Japan Unicar ( Polyethylene D Co., Ltd.
ND-2450 PP-1 ... Mitsui Toatsu Chemical Co., Ltd. polypropylene Noblene JS-G PP-2 ... Mitsui Toatsu Chemical Co., Ltd. polypropylene Noblene BJHH-G flame retardant ... Teijin Chemicals Brominated flame retardant FG7
100 Flame Retardant Aid ... Antimony trioxide manufactured by Nippon Mining & Smelting Co., Ltd.
As is clear from the results of ATOX-S Table 1, the tracking resistance of the polyester resin is significantly improved by the synergistic effect of the components (B) and (C) of the present invention.

[0024]

[Table 1]

Claims (4)

[Claims] 1. A polyester resin composition comprising (A) 1 to 30 parts by weight of a thermoplastic elastomer (B) and 1 to 30 parts by weight of a (C) polyolefin per 100 parts by weight of a polyester resin. 2. The polyester resin composition according to claim 1, wherein the polyester resin is polybutylene terephthalate. 3. The polyester resin composition according to claim 1, wherein the polyester resin is polyethylene terephthalate. 4. The polyester resin composition according to claim 1, wherein the polyester resin is polybutylene naphthalene dicarboxylate.