JPS60235856A - Semiconductive resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent vacuum forming properties, can be vacuum-formed into a thin-wall article and has a semi-permanent antistatic effect, by blending carbon black with a specified styrene/butadiene block copolymer. CONSTITUTION:5-60wt% carbon black such as furnace black is blended with a styrene/butadiene block copolymer having a butadiene content of 10-35wt%, a styrene content of 90-65wt% and an MW of 100,000-250,000. EFFECT:Thin-wall moldings having a uniform thickness can be obtd. without causing a pinhole phenomenon at flexed parts or drawn parts during vacuum forming. USE:Containers for storage and transportation of electronic parts such as LSI, IC, silicon chip, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductive composition with excellent vacuum formability.

Conductive resin compositions have come to be widely used as cases for parts of LSIs and ICs.

Electronic material parts such as LSilC, MO3 type LSI, silicone chips, and silicone wafers are destroyed if they are exposed to static electricity or radio wave interference during transportation or storage, so to avoid this, they are molded with conductive resin compositions. Many storage cases are used.

Among the above-mentioned electronic materials, vacuum-formed products that are lightweight, easy to handle, and have an antistatic effect are convenient as containers for storing and transporting silicone chips and the like.

For this reason, vacuum-formed products made from polyvinyl chloride treated with antistatic treatment have been used, but due to the performance of the current compositions used, they are lighter and thinner, and are suitable for storage of small electronic materials. It has been extremely difficult to stably manufacture transportation containers.

The characteristics of the semiconductive composition required to obtain a molding material that meets the purpose are: ■Processing stability; ■Surface resistance of 10% for vacuum-formed products to achieve the purpose of preventing static electricity. - 106 Ω ■When producing light, thin, short, and small vacuum-formed products, tearing, holes, etc. should not occur in the drawing area, etc.

In view of the above, the present inventors have conducted various studies and found that the butadiene content is 10 to 35%, and the styrene content is 6%.
5 to 90% by weight of styrene-butadiene broth copolymer and carbon bra.

The semiconductive resin composition, which is made by kneading 5 to 50% of silica to impart semiconductivity, has excellent vacuum formability into thin objects (approximately 200μ thick) and has a semi-permanent antistatic effect. We have discovered that it is optimal as a container for storing and transporting materials, and have arrived at the present invention. That is, the present invention has a butadiene content of 10 to 35% and a styrene content of 65 to 90%.
This is a semiconductive resin composition with excellent vacuum formability, which is characterized by blending a carbon blank with a styrene-butadiene broth copolymer of a heavy weight percentage.

The styrene-butadiene polymer copolymer used in the present invention has a butadiene content of 10 to 35% by weight, a styrene content of 65 to 90% by weight, and a molecular weight of 100.000.
~250,000.

Various carbon blanks having electrical conductivity can also be used as the carbon blank used in the present invention, and specific examples thereof include a furnace blank, an acetylene blank, a channel blank, and the like.

The amount used is 5 to 60% by weight, preferably 5 to 40% by weight, based on the total weight of the composition.

In addition, in the present invention, in addition to the above-mentioned components, thermoplastic resins such as GP styrene and Hl styrene, antioxidants, lubricants, etc. may be added as necessary.

As a result of molding a film with a thickness of 200μ by using the semiconductive resin composition of the present invention described above in a vacuum forming machine, there were no holes in the film itself during molding, and there were no holes in the bent or drawn parts. A vacuum-formed product with a constant thickness can be obtained without any phenomenon occurring.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 As shown in Table 1, a styrene-butadiene block copolymer (butadiene content: 25% by weight, styrene content: 7% by weight)
5% by weight, 74 parts by weight (trade name: Ni-Resin KP-03, product of Philisobusvetrolium), 25 parts by weight of acetylene blank, 1 part by weight of zinc stearate, 1.77 parts by weight
! The test Banbury mixer brought the temperature to 170℃.
After the resin is melted and blocked at ~180° C., the rotor is rotated at 76 rpm for 5 minutes to cross-wire so that acetylene black is dispersed in the resin.

After the kneading is completed, the kneaded material is discharged, and a sheet of about 3 squares thick and 20 mm inside is pulled out using a 6"Φ x 12L mixing roll. This sheet is cut into square pellets of 3 x 3 x 3 cranes using a square pelletizer.

The square pellets are processed using a 40mm ΦT-die extruder (L/D=2
A film having a film thickness of 200 μm was molded at a temperature of 180° C. to 200° C. and a screen rotation of 60 rpm.

A box-shaped case was formed by vacuum forming the 200μ film at a temperature of 130°C to 140°C.

The drawn portion of the obtained case was observed for the presence of holes, uneven thickness, etc., and the result was that the wall thickness was uniform and there were no holes.

Examples 2 to 6 Semiconductive resin compositions were obtained using the compositions shown in Table 1 in the same manner as in Example 1. This semiconductor.

Each of the electrically conductive resin compositions was formed into square pellets, and films were formed from the square pellets, and the films of each example were vacuum formed in the same manner as in Example 1 to form box-shaped cases.

The drawn portion of the obtained case was observed for the presence of holes, uneven thickness, etc., and the result was that the wall thickness was uniform and there were no holes.

Comparative Examples 1 to 7 The compositions shown in Table 1 were made into pellets using the same method as in Example 1, and then films were formed from the square pellets.
Vacuum forming was performed in the same manner as above to form a box-shaped case.

As a result of observing the drawing part of the obtained case for the presence of holes, uneven thickness, etc., there were holes in the drawing part.
In particular, there were many breaks at the bending portions, and the desired molded product could not be obtained.

Claims (1)

[Claims] Semiconductor with excellent vacuum formability characterized by blending a carbon blank with a styrene-butadiene block copolymer having a butadiene content of 10 to 35 weight percent and a styrene content of 65 to 90 weight percent. resin composition.