JPH0586274A - Conductive polyester resin composition - Google Patents

Abstract

PURPOSE:To provide the sub composition excellent in moldability, improved in weld strength and suitable for electronic components, automotive components, etc. CONSTITUTION:With 100 pts.wt. plyester (e.g. polyethylene terephtalate) having 0.1-1.2dl/g, preferably 0.5-1dl/g intrinsic viscosity at 23 deg.C, (B) 1-25 pts.wt., prefrably 3-15 pts.wt bisphenol-type epoxy resin having <=1000, preferably <=500 epoxy equivalent, (C) 20-100 pts.wt. preferably 20-80 pts.wt olefinic polymer (e.g. propylene-based polymer), (D) 5-60pts.wt, preferably 10-50 pts.wt. carbon black and (E) 5-100pts.wt., preferably 10-80 pts.wt. inorganic filter (e.g. glass fiber) are blended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive polyester resin composition, more specifically, a conductive polyester resin composition having excellent moldability and improved weld strength, which is suitable for electronic parts and automobile parts. Regarding

[0002]

2. Description of the Related Art Polyester resins have a drawback that during molding, they are hydrolyzed by a small amount of water contained in pellets in an extremely short time, and the mechanical and physical properties of molded articles are significantly deteriorated. is doing. Many improved techniques have been reported to solve the drawbacks of such polyester resins. On the other hand, it has been widely practiced to uniformly disperse carbon black, carbon fibers or the like in a thermoplastic resin so as to impart conductivity.

[0003]

The present inventors have developed an effective technique for solving the problems of these polyester resins, but still have a problem that the weld strength of a molded product is lowered. .. It is an object of the present invention to provide a polyester resin having conductivity and at the same time improved weld strength.

[0004]

According to the present invention, a specific polyester resin is blended with a specific epoxy resin, an olefin-based polymer, carbon black and an inorganic filler, so that electrical characteristics and moldability are improved. They have found that they are excellent and also have improved weld strength, and have completed the present invention.

That is, the present invention comprises the following components (A) to
It is a conductive polyester resin composition comprising (E) and a composition. (A) 100 parts by weight of polyester having an intrinsic viscosity of 0.4 to 1.2 dl / g at 23 ° C. (B) 1 to 25 parts by weight of a bisphenol type epoxy resin having an epoxy equivalent of 1000 or less (C) Olefin-based polymer 20 ˜100 parts by weight (D) Carbon black 5 to 60 parts by weight (E) Inorganic filler 5 to 100 parts by weight Hereinafter, the composition of the composition of the present invention will be described in detail.

Component (A): The polyester (A) used in the present invention comprises an aromatic dicarboxylic acid such as terephthalic acid or naphthalene dicarboxylic acid or an ester-forming derivative thereof as an acid component, and ethylene glycol as a glycol component. It can be obtained by using an aliphatic or alicyclic glycol such as tetramethylene glycol, hexamethylene glycol, cyclohexanediol, or a polycondensate or ester-forming derivative thereof such as polyethylene glycol, or a divalent phenol such as bisphenol A. Typical examples of the polyester (A) include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycyclohexane terephthalate, and mixtures thereof.

The intrinsic viscosity of the polyester (A) used in the present invention is 0.4-1.% As measured at 23 ° C. using a mixed solvent of phenol and tetrachloroethane in a weight ratio of 1: 1.
It is preferably in the range of 2 dl / g, particularly 0.5 to 1.0 dl / g. When it is less than 0.4 dl / g, the improving effect of the present invention on the resin composition is small, and when it exceeds 1.2 dl / g, the fluidity of the composition is extremely poor and molding becomes difficult.

Component (B): The bisphenol type epoxy resin (B) used in the present invention is particularly preferably a bisphenol A type epoxy resin obtained by reacting bisphenol A with epichlorohydrin. The epoxy equivalent is 1000 or less, preferably 500 or less, more preferably 300 or less.

Component (C): The olefin polymer used in the present invention is preferably a propylene polymer, for example, a propylene homopolymer, a copolymer of propylene and ethylene and / or an α-olefin having 4 to 8 carbon atoms. Examples thereof include polymers.

Component (D): Examples of the carbon black (D) used in the present invention include acetylene black, channel black and furnace black, and these can be used alone or in combination of two or more.

Component (E): The inorganic filler (E) used in the present invention is typically glass fiber or mica.

The glass fiber is not particularly limited as long as it is generally used for resin reinforcement. For example, a long fiber type or a short fiber type can be used. Further, the glass fiber may be treated with other surface treatment agents such as a sizing agent (eg, polyvinyl acetate, polyester, etc.) or a coupling agent (eg, silane compound, boron compound, etc.).

As mica, for example, industrially used muscovite or phlogopite can be used.

Besides, carbonates such as calcium carbonate and magnesium carbonate; silicates such as talc, clay and bentonite can be used. Further, like the glass fiber, the surface of these fillers may be treated with a silane chemical or the like.

Blending ratio: The blending amount of the bisphenol type epoxy resin (B) is 1 to 25 parts by weight, preferably 2 to 20 parts by weight, more preferably 3 to 15 parts by weight, based on 100 parts by weight of the polyester (A). Is. If it is less than 1 part by weight, the effect of improving the weld strength is small, and if it exceeds 25 parts by weight, the surface of the molded article becomes sticky and the fluidity of the composition during molding becomes unstable.

The amount of the olefin polymer (C) compounded is 20 to 100 parts by weight, preferably 20 to 80 parts by weight, based on 100 parts by weight of the polyester (A). If it is less than 20 parts by weight, the effect of improving the weld strength of the present invention is small, and if it exceeds 100 parts by weight, the mechanical strength of the product is significantly lowered.

The amount of carbon black (D) is 5 to 60 parts by weight based on 100 parts by weight of polyester (A).
It is preferably 10 to 50 parts by weight. If it is less than 5 parts by weight, the electrical properties are unsatisfactory, and if it exceeds 60 parts by weight,
The fluidity of the composition is remarkably reduced and molding becomes difficult.

The amount of the inorganic filler (E) compounded is 5 to 100 parts by weight, preferably 10 to 80 parts by weight, based on 100 parts by weight of the polyester (A). If the amount is less than 5 parts by weight, the reinforcing effect of the filler is insufficient and the mechanical strength of the product is insufficient. On the other hand, if it exceeds 100 parts by weight, the fluidity of the composition remarkably decreases and the appearance of the product deteriorates.

Mixing / Kneading / Molding: The composition of the present invention is produced by using an ordinary mixer, kneader or the like. That is, each component is put into a V-type blender, a ribbon blender, a tumbler, or the like and uniformly mixed, and then melt-kneaded by a normal extruder such as a uniaxial or biaxial extruder, cooled, and then cut into pellets. At this time, a part of the glass fiber and other components may be added in the middle of the extruder. Alternatively, a part of the components may be mixed and kneaded in advance, and then the remaining components may be added and extruded.

The composition of the present invention contains a flame retardant (for example, brominated bisphenol,
Brominated epoxy resin, red phosphorus, etc.), flame retardant aid (eg, antimony trioxide, sodium antimonate, etc.), nucleating agent (eg, sodium stearate, ethylene-sodium acrylate copolymer, etc.), stabilizer (eg, (Phosphoric acid ester, phosphorous acid ester, etc.), antioxidant, light stabilizer, foaming agent, lubricant, release agent and the like may be added. The composition thus obtained can be molded by any method such as injection molding, extrusion molding, compression molding and the like.

[0021]

【Example】

Examples 1 to 4 and Comparative Examples 1 to 4 Polyethylene terephthalate having an intrinsic viscosity of 0.7 dl / g as component (A), Velpet PBK-1 (trade name, manufactured by Kanebo Co., Ltd.), and bisphenol A type epoxy as component (B). Resin, Epicoat 828 (trade name, manufactured by Yuka Shell Epoxy Co., epoxy equivalent: 189), propylene resin as component (C), Mitsubishi Noblen BC8Q (trade name, manufactured by Mitsubishi Petrochemical Co., Ltd.), Ketjen as component (D) Carbon (trade name, manufactured by Lion Akzo), glass fiber T198H (manufactured by Nippon Electric Glass Co., Ltd.) and mica 200W as component (E)
(Trade name, manufactured by Kuraray Co., Ltd.) was mixed in a weight ratio of 1: 4, and the above was mixed in a tumbler in a mixing ratio of Table 1 and then, using an extruder having a diameter of 40 mm, a cylinder set temperature of 27
The mixture was kneaded and extruded at 0 ° C to form a pellet.

The pellets thus obtained were dried in a dryer at 130 ° C. for 5 hours, and then a test piece for evaluation was prepared in a 6 ounce injection molding machine at a cylinder setting temperature of 270 ° C. and a mold setting temperature of 80 ° C. The tensile strength and surface resistivity of the weld zone were measured, and the results are shown in Table 1. Comparative Examples 1 to 1 lacking (B) or (C) from the formulation of Table 1 or containing no compatible amount
In No. 4, the weld strength was significantly reduced.

[0023]

[Table 1]

[0024]

INDUSTRIAL APPLICABILITY As described above, the present invention provides an electrically conductive polyester resin composition which is electrically conductive and has little decrease in weld strength during molding.

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Claims (1)

[Claims] 1. A conductive polyester resin composition comprising the following components (A) to (E) and a composition. (A) 100 parts by weight of polyester having an intrinsic viscosity of 0.4 to 1.2 dl / g at 23 ° C. (B) 1 to 25 parts by weight of a bisphenol type epoxy resin having an epoxy equivalent of 1000 or less (C) Olefin-based polymer 20 To 100 parts by weight (D) carbon black 5 to 60 parts by weight (E) inorganic filler 5 to 100 parts by weight