JPS60173027A - Electroconductive polyolefin resin composition - Google Patents

Abstract

PURPOSE:The titled resin composition of excellent moldability, prepared by adding electroconductive carbon black, a flaky electroconductive filler, and a dielectric material to a polyolefin resin. CONSTITUTION:A polyolefin resin (MI of about 0.5-20g/10min) is melt-blended with about 5-40wt%, based on the total composition, electroconductive carbon black (e.g., furnace black), about 5-50wt% flaky electroconductive filler (e.g., graphite of a particle diameter of about 0.5-500mu) and about 3-30wt% dielectric material of a dielectric constant of about 10-30,000 (e.g., titanium dioxide, barium titanate, or strontium titanate).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conductive polyolefin resin composition that has excellent moldability in injection molding and the like.

In recent years, conductive composite materials have been diversified and have become increasingly diverse in their conductivity and applications.

Among these trends, conductive composite materials with extremely low resistance values, including electromagnetic shielding materials, are currently attracting particular attention.

Initially, a material in which carbon black was blended with polyolefin resin was considered as a material to meet this demand, but
It is difficult to obtain sufficiently satisfactory conductivity by blending carbon black alone, and in this case, a large amount of carbon black is mixed into the resin, so the resin composition must be adjusted due to the oil absorption of the filler. The fluidity during melting was significantly inhibited, making it difficult to put it to practical use.

In addition, conductive composite materials are being considered in which metal fillers with a so-called high spectral ratio, such as metal fibers and metal flakes, are blended instead of the carbon black, but these materials are heavy due to their high specific gravity, and are bulky due to the use of powder fillers. It was not preferred in practice because it had inferior moldability and was more expensive than those using.

In view of the above, the inventors of the present invention have conducted intensive research to obtain a conductive composite material having an extremely low resistance value that is mainly composed of carbon black as a conductive filler to be added to a polyolefin resin. By blending high dielectric materials such as graphite and titanium dioxide in addition to a small car pump, the fluidity of the polyolefin resin during melt-kneading hardly decreases, resulting in good processability. The present invention was achieved by discovering that a conductive composite material having an extremely low resistance value can be obtained.

That is, the present invention provides a conductive polyolefin resin composition in which a polyolefin resin is blended with conductive carbon black and a scaly conductive filler, which is characterized in that a dielectric material is blended into the composition. It is a resin composition.

The polyolefin resin used in the present invention is polyethylene, polypropylene, polybutene-1, etc., and preferably has a melt index (MI
) is preferably 0.5 to 20 f/10 min.

The conductive carbon black used in the present invention includes furnace black, acetylene black, channel black, etc.
It is used in range I of 0% by weight, but from the viewpoint of conductivity and moldability, the preferred blending amount is 15 to 35% by weight.

Graphite, which is one of the scale-like conductive fillers used in combination with the conductive carbon black, may be natural or artificial, and has a particle size of 0.5 to 50.
0 microns are used, but the preferred particle size is 1
~300 microns. The graphite is blended in the composition in an amount of 5 to 50% by weight, preferably 10 to 40% by weight.

Next, the scaly metal filler used in the present invention is aluminum flakes, nickel-coated mica, etc. with a particle size of 0.5 to 1000 microns, but a preferable particle size is 1 to 50 microns. It is something. These metal fillers are blended within the range of 3 to 30% by weight in the composition, but the preferred blending amount is 5 to 20% by weight.
It is.

Furthermore, the electrically conductive material used in the present invention includes titanium dioxide,
Calcium titanate and magnetic titanate preferably have a molecular weight of 30 to 30,000.

The above-mentioned W1 material is blended in the composition in an amount of 3 to 30% by weight, preferably 5 to 20% by weight.

Modification of the resin with BAA, KBA, butyl rubber, etc., addition of metal salts of higher fatty acids such as stearic acid used as dispersants, addition of antioxidants, coupling agents, etc. can be carried out in any proportion. However, the effects of the present invention are not impaired in any way.

The conductive polyolefin resin composition of the present invention described above is
When subjected to extrusion molding or injection molding, it shows extremely excellent fluidity and has good moldability.

Furthermore, the obtained molded product has an extremely low resistance value and is extremely effective as a material for electromagnetic shielding materials, etc. The present invention will be specifically described below using Examples.

Test pieces of the blended compositions used in Examples and Comparative Examples were prepared and measured by the following method.

Note that the parts in Examples and Comparative Examples are based on weight. The blends on each side were kneaded at a temperature of 200C using a kneader (trade name: Labo Plastomill, manufactured by Toyo Seiki Co., Ltd.).

The obtained mixed material is further placed in a mixing roll at a temperature of 1
30 tl: Knead at ~iso°C for 3 minutes and draw out into a plate shape with a thickness of about 2 mm, and further obtain square pellets using a square pelletizer.

A part of this square pellet was used for fluidity measurement, and the fluidity was evaluated using Melt Index-9-(23 (1, 21, 6Of). The results are shown in Table 1.

Further, about 5 of the square pellets were formed into a plate shape using an electric heat press molding machine at a temperature of 19 (l).

The obtained molded plate was punched out to a width of 20 mff1. length 12
0 words.

A test piece with a thickness of 11111 mm is prepared. A conductive paint is applied to both ends of this test piece to obtain a test piece for measuring volume resistivity. The resistance value was measured using this measurement piece, and the results of the volume resistivity values are shown in Table 1.

Example 1 High-density polyethylene (trade name;) Izex 2100
J 6 B part Mitsui Petrochemicals product MI=6.5, d=o
, 9s) carbon black (product name: Ketchen EC1
Part 2 Rauon Akzo product) Graphite (product name: cssp Nippon Graphite product),
10 parts barium titanate (trade name: B'r-3036=
=10000 io part Fuji Titanium Industries product) Example 2゜Polypropylene (Product name: Mitsui Noblen JHHG s
Part 9 Mitsui Toatsu product, Mr=a, o, d=0.9o) Carbon black (Product name: Denka Black 25 part Denki Kagaku Kogyo product) Graphite (Product name: HAG-150, Nippon Graphite product) 8 parts titanium dioxide (product name: RCK-206
=76 s part Bayer product) Example 3 High density polyethylene (trade name; /) Izex 1300
J 59th part Mitsui Petrochemicals product, MI=14.0, d=
0.94) Carbon black (Product name: Conductex, From 25 parts, Via Carbon Co., Ltd. product) Graphite (Product name: HAG-150, Nippon Graphite Co., Ltd. product) 8 parts Titanium dioxide (Product name: RCK-20, E
=76 s part Bayer product) Example 4 High density polyethylene (same as Example 3) 59 parts carbon black (same as Example 3) 25 parts graphite (
Same as Example 3) 8 parts calcium titanate (trade name;
CT, Fuji Titanium 8 parts Kohatasha product) Example 5 High-density polyethylene (same as Example 3) 59 parts carbon black (same as Example 3) 25 parts graphite (
Same as Example 3) 8 parts barium titanate (trade name: B
T-204E = 30000 S part Fuji Titanium (Kurisha product) Comparative example 1゜ High density polyethylene (Product name: Hi-ZEX 50008
80 parts Mitsui Petrochemicals product, MI =0.9, a=
0.9 s) Carbon black (trade name: Ketjen EC, Lion 20 parts Akzo product) Comparative example 2゜ High density polyethylene (same as comparative example 1) 75 parts carbon black (same as comparative example 1) 15 parts graphite (
Same as Example 3) 10 parts Comparative Example 3 Polypropylene (Product name: Mitsui Noblen JHHG 6
0 parts Mitsui Toatsu product, MI=8, d=o, 9o) Carbon black (product name: Denka Black 40 parts Denki Kagaku Kogyo product) Comparative example 4° High-density polyethylene (product name: - Izetskus 1300)
J 65th part Mitsui Petrochemicals product, MI=14, d=o,
c+s) Carbon black (trade name: Conta Sotex, 35 parts Columbia Carbon product) Comparative example 5° High density polyethylene (same as comparative example 4) 60 parts carbon black (same as comparative example 4) 30 parts graphite (
Product name; cssp Nippon Retsusensha? ! ! Item) Part 10
1 Table ratio

Claims (2)

[Claims] (1) A conductive polyolefin resin composition comprising a HoIJ olefin resin blended with conductive carbon black and a scale-like conductive filler, characterized in that a dielectric material is blended into the composition. thing. (2) The conductive polyolefin resin composition according to claim 1, wherein the dielectric material is one or more of titanium dioxide, barium titanate, calcium titanate, magnesium titanate, strontium titanate, and the like.