JPS6086142A - Composite material of electrically conductive resin - Google Patents

Abstract

PURPOSE:To provide a lightweight composite material having low specific volume resistivity and containing a small amount of Al in high dispersibility without being affected with shearing and deformation, by applying a polyphosphate-type titanate to an Al fiber, and compounding a styrene resin with the treated Al fiber. CONSTITUTION:A polyphosphate-type titanate is applied to an Al fiber and an Al filler, and the fiber and filler are filled and dispersed in a styrene resin in an amount of 1-25%. The Al fiber has a length of 3-5mm. and a diameter of 90mu. The polyphosphate-type titanate is isopropyl tristitanate, bisoxyacetate titanate, or bisphosphite titanate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a conductive resin composite material in which A1m fibers are mixed into a styrene resin.

[Field of application of the present invention]

The above-mentioned conductive resin composite material can be used for cases of computers or various electronic devices.

[Prior art]

Conventional conductive resin composite materials include: (1) JP-A-57-78439 "Conductive resin composition"
According to the publication, conductive carbon black is added to styrene resin.
There is also a description of a resin composition containing a styrene-imprene copolymer, (2) JP-A-58L78499.
No. 2, No. 2003, "Resin Materials for Electromagnetic Shielding" describes a resin composition in which metal fibers made of brass or AA are mixed into ABS resin.

[Problems in the prior art and technical analysis thereof] The resin composition obtained by mixing carbon black into the styrenic resin described in (1) above has a conductive volume resistivity value (hereinafter referred to as "specific resistance") of 10 to 10. The value of Ω·Cm is higher than the national target value of 101Ω·Cm for conductive resin composite materials, and it is only used for antistatic purposes.

In addition, in the conductive resin composite material (2) above, which is made by mixing brass metal fibers with ABS resin, the specific resistance is 10 Ω.
Although fluorine has a good effect on preventing electromagnetic interference, it has a high specific gravity (specific gravity = 8.4) and a high volumetric filling rate of 15% when mixed into the resin. is 2.2, which is close to the specific gravity of Al alone, which is 2.7, and has no merit at all in terms of weight.

In addition, in the composite material in which AI2 fibers are mixed with the ABS resin described in (2) above, the conductive resistivity is 10-/20% because the mixed beta fibers are sheared or deformed and bent during cross-wiring by the extruder.
~102Ω・CII+ range, target value 10-:L
[Technical problem to be solved] Therefore, the present invention provides a metal fiber made of Al.

Or, filler is filled and mixed into the resin to create a conductive resin composite with a low Al filling rate, a specific gravity within the range of 1.2 to 1.5, and a specific resistance of 10-2 Ω・cm or less. The technical challenge is to provide materials.

[Technical means] As a technical means taken to solve the above technical means, hexa-β fibers (including AA gold alloy) are mixed into styrene resin to form a resin composite material, and an extruder is used to mix the fibers. ,
Extrusion is performed to produce pellets with a length of several cranes, but during the kneading process in the extruder, A
In order to prevent deformation such as shearing or bending of the A-woven fibers, a lubricant is added to improve the sliding between the styrene resin and the AI2 fibers, and the sliding between the Aj2 fibers, and to prevent shearing and deformation of the AN fibers. is used.

The lubricant needs to be one that can easily adhere uniformly to the metal surface and has a high degree of activity. Polyphosphoric acid-based titanates, which have good chemical bonding properties with Al (and good compatibility with resins), are required. Very appropriate.

[Effect of technical means]

The above technical means works as follows. In other words, tikunates of organic titanium compounds are used to bond polymeric materials and inorganic materials, or to improve their affinity and improve physical properties.
It is used as a reagent, that is, a coupling agent, and is effective against inorganic substances such as calcium carbonate, mica, and talc. It is something that can be used.

First, polyphosphoric acid titanate is dissolved in an organic solvent such as toluene, and a 3-5 m long, 90μ Al fiber is immersed in the solution, dried, and an extremely thin film (monomolecular film) is formed around the outer periphery of the Al fiber. ) is formed, so there is no inhibiting effect on the conduction of electricity to the A/2 fibers.

After surface treating the Al fibers with the titanate, A7! is applied to the styrene resin. Fibers are mixed in at 15 VOL% and kneaded using an extruder to form pellets with a length of about 3 to 5 grains. In this case, due to the action of the titanate as a lubricant, pellets with less shearing and deformation of the Al fibers and sufficiently dispersed in the styrenic resin can be obtained.

Next, the pellets are heated with an injection molding machine, and after melting, a molded article of a certain shape is obtained. There is a polymer (AS), and the polyphosphoric acid titanates include isopropyl tris titanate, bisoxyacetate chicknate, and bisphosphite chicknate.

[Special effects produced by the present invention]

The present invention produces the following unique effects. That is, by using titanate polyphosphate as a lubricant in the (11 styrene resin), the frictional force between the A7! fibers and the resin can be alleviated, and shearing and deformation of the Al fibers will not occur.

(2) AJ in resin! The dispersion of the 1lfi fibers is much better, so the filling amount of Al fibers is reduced, and the specific gravity of the composite resin is reduced.

(3) The conductive volume resistivity value reaches 10-2 Ω·cm, and it can be widely used as a molded product for the housing of various electronic devices.

〔Example〕

Hereinafter, specific examples of the above technical means will be described.

Example-1 Isopropyl tris (dioctyl pyrophosphate)
Titanate is dissolved in toluene, an organic solvent, and Al fibers (length 3×, thickness 90μ) are immersed in this solution.
Approximately 1 wt% titanate was attached to the surface of the fiber.

This Al fiber was mixed into an ABS resin at 15 νOL%, extruded and kneaded using a twin-screw extruder, and a test piece was prepared using an injection molding machine. As a result of visual inspection of the test piece, the length of the Al
The fibers were almost unaffected by shearing and were uniformly and widely dispersed with a length of about 3 mm.The specific resistance of a 1100 x 100 x 2 test piece was measured using an electrometer. This is shown in Table 1 along with the specific gravity.

Example-2 Al
Approximately 0.5 wt% was attached to fibers (length 3+u, thickness 90μ) to produce a test piece of ABS resin composite. The results are shown in Table 1. Example 3 Az woven fibers (length 3*ta, thickness 90μ) were mixed with 15 VOL% of ABS resin without adhering titanate.
A test piece was manufactured in the same manner as in Example-1. The results are shown in Table 1.

In addition, as a result of visual inspection of the test piece, approximately 2/3 of the Al fibers were cut to 1/2 to 1/3 of the length due to shearing caused by cross-wire.

Example-4 The titanate of Example-2 was used on Al fiber (length 2 cranes, thickness 50μ), and the Al
A test piece of an ABS resin composite with 5% OL was produced by adhering about 1wt% to the fibers. The results are shown in Table 1.

Example 5 A test piece was produced that was the same as Example 4, but without the titanate treatment on the Al fibers. The results are shown in Table 1.

Table 1

Claims (2)

[Claims] (1) A conductive resin composite material in which polyphosphoric acid titanate is attached to a styrene resin, and Al fibers or Ad fillers are filled and dispersed. (2) The conductive resin composite material according to claim 1, wherein 1 to 25 VOL% styrene resin is filled with Al fibers or AA filler to which the polyphosphoric titanate is attached.