JPH08198999A - Electroconductive resin composition - Google Patents

Abstract

PURPOSE: To provide an electroconductive resin composition which comprises a polyphenylene ether resin and the like, carbon black and an ethylene-α-olefin copolymer resin, thus is useful for packaging IC because it is improved in staining of IC or the like with carbon black migrating from the resin by abrasion. CONSTITUTION: (A) 100 pts.wt. of at least one of thermoplastic resin selected from among poly(phenylene ether), polystyrene resin and ABS resin are combined with (B) 5 50 pts.wt. of carbon black, further, 100 pts.wt. of the composition are mixed with (C) 1-30 pts.wt. of an ethylene-α-olefin copolymer resin of less than 90 surface hardness measured with the durometer type A according to JIS K-7215 to give this electroconductive resin composition which is suitable for packaging.IC because it has a surface resistivity of 10<2> -10<10> ohms and markedly reduces the staining of IC or the like with carbon black migrating from the resin by abrasion on the contact with IC or the like.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a conductive resin composition for IC packaging which comprises a thermoplastic resin selected from at least one kind of polyphenylene ether resin, polystyrene resin or ABS resin and carbon black.
By incorporating an ethylene-α-olefin copolymer resin in this conductive resin composition, IC causing desorption of carbon black or the like due to abrasion at the time of contact with the IC or the like
The present invention relates to a conductive resin composition for IC packaging, in which contamination such as the like is remarkably reduced.

[0002]

2. Description of the Related Art Conventionally, injection trays, vacuum forming trays, magazines, embossed carrier tapes, etc. have been used as packaging forms for ICs and electronic parts using ICs, and these packaging containers are damaged by static electricity. (1) a method of applying an antistatic agent on the surface of the packaging container, and (2) a method of applying a conductive paint,
(3) A method of dispersing an antistatic agent or a conductive filler is implemented.

However, the method (1) has a sufficient antistatic effect immediately after coating, but after a long time of use,
Stable performance cannot be obtained because the antistatic agent is liable to be released due to water outflow and abrasion. The surface resistivity is also 1
It is about 0 ⁹ to 10 ¹² Ω, which is unsuitable for IC packaging that requires a strict antistatic effect. In the method (2), the coating tends to be non-uniform in the manufacturing process, and the antistatic effect is lost due to peeling off due to abrasion.
It has the drawback of destroying C and contaminating the leads of the IC. In the method (3), the antistatic agent requires a large amount to be added, so that the physical properties of the resin are deteriorated, and the surface resistivity is greatly affected by humidity, so that stable performance cannot be obtained.

As the conductive filler, fine metal powder,
Examples thereof include carbon fiber and carbon black. The metal fine powder and the carbon fiber have sufficient conductivity even if added in a small amount, but the moldability remarkably deteriorates, and it is difficult to disperse them uniformly, and a skin layer containing only a resin component on the surface of the molded product. It is difficult to obtain a stable surface resistivity value. On the other hand, carbon black is generally used because it is possible to disperse it uniformly by studying the kneading conditions, etc. and it is easy to obtain a stable surface resistivity value, but it is necessary to add a large amount of carbon black. There is a phenomenon that fluidity and moldability are deteriorated due to the presence of

Conventionally, as a resin for dispersing carbon black, polyvinyl chloride resin, polypropylene resin, polyethylene terephthalate resin,
Polystyrene resin and ABS resin are 100 ℃
Polyphenylene ether resin for heat resistance above,
Polycarbonate resin or the like is used. Among these resins, polyphenylene ether resins are used for heat resistance, and polystyrene resins and AB for general use.
The S-based resin is excellent in terms of cost without significant deterioration in fluidity and moldability even when a large amount of carbon black is added. However, the molded product of the composition to which a large amount of carbon black is added has a drawback that carbon black is easily detached from the surface of the molded product due to abrasion.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve such a drawback and comprises a thermoplastic resin selected from at least one of polyphenylene ether resin, polystyrene resin or ABS resin and carbon black. In a conductive resin composition for IC packaging, the conductive resin composition further contains an ethylene-α-olefin copolymer resin to obtain a molded article for IC packaging made of the conductive resin composition. , Molded articles and I
It is an object of the present invention to provide a conductive resin composition for IC packaging in which contamination of IC and the like due to detachment of carbon black and the like caused by contact and abrasion with C and the like is significantly reduced.

[0007]

That is, the first aspect of the present invention
Is a thermoplastic resin selected from at least one of (A) polyphenylene ether resin, polystyrene resin or ABS resin, (B) carbon black and (C) ethylene-α-olefin copolymer resin. In a conductive resin composition for IC packaging, (a) contains 5 to 50 parts by weight of carbon black (B) per 100 parts by weight of the thermoplastic resin (A), and contains (A) the thermoplastic resin. (B) 1 to 30 parts by weight of (C) ethylene-α-olefin copolymer resin having a durometer A type surface hardness of 90 or less according to JIS-K-7215 is contained with respect to 100 parts by weight of the total amount of carbon black. And (b) the surface specific resistance value of the conductive resin composition is 10 ²
The conductive resin composition for IC packaging is characterized by having a resistance of 10 to 10 ¹⁰ Ω.

The present invention will be described in more detail below. In the present invention, (A) polyphenylene ether resin,
A thermoplastic resin selected from at least one type of polystyrene-based resin or ABS-based resin is used, and the polyphenylene ether-based resin means a resin containing polyphenylene ether resin and polystyrene-based resin as main components, and polyphenylene ether resin and polystyrene-based resin. Total amount of resin 10
The content of the polyphenylene ether resin in 0 part by weight is preferably 28 to 86 parts by weight. If it is less than 28 parts by weight, sufficient mechanical properties as a polyphenylene ether resin cannot be obtained, and if it exceeds 86 parts by weight, fluidity is deteriorated. Molding becomes difficult. The polyphenylene ether resin is a homopolymer or copolymer described in US Pat. No. 3,383,435.

The polystyrene resin used in the present invention is a general polystyrene resin or a high impact polystyrene resin and a resin containing a mixture thereof as a main component.
The system resin means a resin containing a copolymer mainly composed of acrylonitrile-butadiene-styrene as a main component.

The carbon black (C) used in the present invention is furnace black, channel black, acetylene black, etc., preferably having a large specific surface area,
High conductivity can be obtained with a small amount added to the resin. For example, S. C. F. (Super Condu
active Furnace), E.I. C. F. (Ele
ctric Conductive Furnac
e), Ketjen Black (trade name of Lion-AKZO) and acetylene black. The amount of carbon black added is such that the surface resistivity can be 10 ² to 10 ¹⁰ Ω, and (B) 5 to 50 parts by weight of (B) carbon black per 100 parts by weight of the thermoplastic resin. Is preferred. If the addition amount is less than 5 parts by weight, sufficient conductivity cannot be obtained and the surface resistivity value increases.
If the amount exceeds 0 parts by weight, the uniform dispersibility with the resin deteriorates, the molding process becomes difficult, and the characteristic values such as mechanical strength decrease. If the surface resistivity exceeds 10 ¹⁰ Ω, a sufficient antistatic effect cannot be obtained, and if it is less than 10 ² Ω,
The conductivity is too good, and electromotive force may be generated by electromagnetic induction or electrostatic induction, which may damage the IC.

The ethylene-α-olefin copolymer resin (C) used in the present invention is a resin in which ethylene and α-olefin are copolymerized, and as the α-olefin copolymerized with ethylene, poroprene and butene-1 are used. , Pentene-1, hexene-1, etc., for example, Mitsui Petrochemical Company,
Examples are "Tuffmer P" and "Tuffmer A". The ethylene-α-olefin copolymer resin is JIS-K-7215.
Durometer A-type surface hardness of 90 or less is preferable, and the melt flow index (JISK-721
0) is 0.1 g / 10 minutes or more under the conditions of 190 ° C. and a load of 2.16 kg. Below this value, polyphenylene ether resin, polystyrene resin, AB
Kneading with the S-based resin becomes difficult, and a good composition cannot be obtained. The addition amount of the ethylene-α-olefin copolymer resin is preferably 1 to 30 parts by weight, and particularly preferably 3 to 25 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic resin and the carbon black. If the addition amount is less than 1 part by weight, the effect is insufficient, and if it exceeds 30 parts by weight, polyphenylene ether resin, polystyrene resin, ABS are used.
It becomes difficult to disperse the resin uniformly in the resin.

The conductive resin composition of the present invention has a surface resistivity of 10 ² to 1 in order to maintain sufficient moldability.
When carbon black is filled to 0 ¹⁰ Ω,
Melt flow index (measured according to JIS-K-7210) is 230 ° C. under a load of 10 kg when filled in a polyphenylene ether resin, and 200 ° C. under a load of 5 kg when filled in a polystyrene resin. When filled with ABS resin, 220 ° C, load 10
Under the condition of kg, each is 0.1 g / 10 minutes or more.

Further, in the conductive resin composition of the present invention, a lubricant, a plasticizer, a processing aid, a reinforcing agent for improving the mechanical properties of a molded article, etc. for improving the fluidity properties may be added, if necessary. Various additives and other resin components can be added. In the present invention, a known method such as a Banbury mixer or an extruder can be used for kneading and pelletizing various raw materials such as resin.

[0014]

EXAMPLES The present invention will now be described in more detail with reference to examples. Examples 1 to 4 Raw materials were weighed at the raw material composition ratios shown in Table 1, uniformly mixed by a high-speed mixer, then kneaded using a φ45 mm vent type twin-screw extruder, and pelletized by a strand cut method. . Next, the pelletized resin composition is used as sample M.
Is a φ65 mm extruder (L / D = 28) and is 500 mm
What was molded into a sheet shape with a thickness of 500 μm by a T-die having a width, Sample N was an injection molding machine (100
A sample for evaluation was formed by t) in the form of a plate having a thickness of 1 mm × 120 mm square and a test piece for tensile measurement. The evaluation results are shown in Tables 3 and 4. In each example, the carbon black did not fall off.

Comparative Examples 1 to 4 In the same manner as in Example 1, the raw materials were weighed at the raw material composition ratios shown in Table 2, uniformly mixed by a high speed mixer, and then φ
The mixture was kneaded using a 45 mm vent type twin-screw extruder and pelletized by a strand cut method. Next, the pelletized resin composition was used to prepare and evaluate Samples M and N. The evaluation results are shown in Tables 3 and 4. In each comparative example, it was confirmed that the carbon black had fallen off.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

[0019]

[Table 4]

Each evaluation was performed by the following method. (1) Surface specific resistance For both samples M and N, the distance between the electrodes was set to 10 mm using a Lorester surface resistance meter (manufactured by Mitsubishi Petrochemical Co., Ltd.), and arbitrary 10 points in the sample were measured, and the logarithmic average value thereof was taken as the surface specific resistance. (2) Strength at Break, Tensile Elastic Modulus According to JIS-K-7113, Sample M is 2
For the No. 1 type test piece and the sample N, the No. 1 type test piece was measured at a tensile speed of 10 mm / min.

(3) Presence or absence of carbon loss QFP 14 mm on the surface of each sheet and plate sample
An IC of × 20mm / 64pin is pressed with a load of 100g, and a stroke of 15mm is made to reciprocate 100 times.
The lead portion of C was observed with a microscope. It was evaluated by the presence or absence of black deposits such as carbon black on the lead portion. (4) MFI The pellets of Examples and Comparative Examples were measured according to JIS-7210.

[0022]

As described above, in the conductive resin composition for IC packaging, which comprises (A) a thermoplastic resin selected from at least one kind of polyphenylene ether resin, polystyrene resin or ABS resin, and carbon black. By further adding an ethylene-α-olefin copolymer resin to this conductive resin composition, the contamination of IC or the like caused by the desorption of carbon black due to abrasion at the time of contact with IC or the like is significantly reduced. It is possible to obtain the conductive resin composition.

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Claims (1)

[Claims] 1. A polyphenylene ether resin (A),
In a conductive resin composition for IC packaging, which comprises a thermoplastic resin selected from at least one type of polystyrene resin or ABS resin, (B) carbon black and (C) ethylene-α-olefin copolymer resin, a) 5 to 50 parts by weight of (B) carbon black is contained per 100 parts by weight of the (A) thermoplastic resin, and the total amount of the (A) thermoplastic resin and (B) carbon black is 100 parts by weight. On the other hand, it contains 1 to 30 parts by weight of (C) ethylene-α-olefin copolymer resin having a Durometer A type surface hardness of 90 or less according to JIS-K-7215, and (b) a conductive resin composition. Surface resistivity of 10 ²
A conductive resin composition for IC packaging, which has a resistance of 10 to 10 ¹⁰ Ω.