JPS59109562A - Carbon black and electrically conductive composition containing the same - Google Patents

Abstract

PURPOSE:To provide carbon black which has specified physical properties (pH, specific surface area, or iodine adsorption) and can impart excellent electrical conductivity to synthetic resins and rubbery materials without detriment to mechanical characteristics when added to them, by heat-treating a mixture of a polymer and carbon black. CONSTITUTION:A mixture consisting of a polymer and/or a bituminous substance (A) which are/is substantially converted into carbon when heated at 1,000 deg.C or above (e.g. vinyl chloride resin, acrylonitrile resin, or asphalt) and carbon black (B) (e.g. acetylene black or by-product black), is granulated and heat-treated in a non-oxidizing atmosphere at 1,000-1,600 deg.C to obtain carbon black having a pH of 9 or above, a specific surface area of 40-70m<2>/g and an iodine adsorption of 50-80mg/g. The carbon-source material and the raw carbon black are mixed in such a proportion that the ratio of carbon formed from the carbon-source material by the heat treatment accounts for 1-30wt% of the quantity of electrically conductive carbon black.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides carbon black suitable for imparting conductivity to synthetic resins and/or rubber-like substances (hereinafter referred to as "highly conductive black") and highly conductive black to synthetic resins and/or rubber materials. The present invention relates to a conductive composition contained in a substance.

It has been known to cool carbon black, such as eva-acetylene black, special conductive furnace black, and by-product carbon black during the production of synthetic resins and/or rubber materials, in order to impart electrical conductivity to synthetic resins and/or rubber-like substances. ing. Table 1 shows the physical properties of specific examples.

When added to synthetic resins and/or rubber-like substances with high resistance, a composition with good electrical conductivity can be obtained. However, if this is removed, an attempt is made to provide fluidity, mechanical rank, and conductive compositions containing this. The first aspect of the present invention
The invention relates to a carbon blank with a pH of 9 or higher and a specific surface area of 40 to 7, obtained by thermally decomposing a mixture of a raw material carbon blank and a polymer and/or bituminous material that essentially becomes carbon at a temperature of 1000°C or higher.
0tr? /? , iodine adsorption amount 50-80 mg/? The second invention is a highly conductive carbon black that is
The highly conductive carbon blank of the invention and the synthetic resin and/or rubbery substance were combined into 7L each of 50 to 100 parts by weight and io
It is an electrically conductive composition containing 0.0 M parts.

The present invention will be further explained in detail below.

The first invention of the present invention is a highly conductive carbon black obtained by thermally decomposing a mixture of a specific l)mer and/or bituminous material and carbon black at a temperature of 1000°C or higher, which is obtained by heat-treating a mixture of raw material carbon black and a polymer and/or bituminous material (hereinafter referred to as carbon source material) that essentially becomes carbon at a temperature of 1000° C. or higher at a high temperature. To further explain the manufacturing method, first, specific examples of carbon source materials include vinyl chloride resin, acrylonitrile resin, styrene resin, polyethylene resin, ethyne-vinyl acetate copolymer resin, nuthylene-butanoene copolymer latex, and natural rubber. , tar, pitch, asphalt, etc.

Although any raw material carbon black may be used, it is preferable to use the above-mentioned acetylene black or by-product black that has a certain degree of conductivity. The ratio of the carbon source material to the raw material carbon black is such that after heat treatment, the carbon produced by thermal decomposition of the carbon source material is contained in the high thermal conductivity carbon black in a ratio of 1 to 30% by weight. The reason is that if it is less than 1% by weight, the electrical conductivity is not sufficient, and if it exceeds 30% by weight, the amount of plate grains will increase. These raw materials are used after being granulated using a suitable granulator using water or a solvent as a medium. The heat treatment of this granulated material must be carried out at a temperature of 1000 DEG C. or higher, preferably 1000 to 1600 DEG C., in a non-oxidizing atmosphere, such as nitrogen, hydrogen, argon, helium, or the like. If the heat treatment temperature is less than 1,000°C, the effect of improving conductivity imparting performance will not be sufficient, and if it exceeds 1,600°C, it will tend to graphitize, depending on the type of raw material carbon black, and the conductivity imparting performance will deteriorate. be. The carbon black thus obtained has a pH of at least 9 or higher,
Specific surface area 40-70tr? /? , iodine adsorption amount is 50-8
0 my/q, and when blended with a synthetic resin and/or a rubbery substance, a conductive composition having desired physical properties can be obtained.

pH value less than 9, specific surface area 40 tr? /? Less than 50 mV' of iodine adsorption? If the specific surface area exceeds 70 tn"/f and the amount of iodine adsorption exceeds 80 tn"/2, the conductivity imparting ability increases. When added to a substance to form a composition, the fluidity becomes poor, which is not preferable.

Next, the second invention will be explained. The second invention is a conductive composition in which the highly conductive carbon black of the first invention is blended with a synthetic resin and/or a rubber-like substance. Highly conductive car array? Specific examples of synthetic resins and/or comb-like materials (hereinafter referred to as base polymers) in which Emplanoc is blended include (1) polyethylene resins, ethyl-vinyl acetate copolymer resins, polyethylene resins, styrene resins, vinyl chloride resins, and acetic acid. Thermoplastic resins such as vinyl resin, methacrylic resin, acrylonitrile-butanoene-styrene copolymer resin, polyphenylene oxide (ppo resin), modified ppo IJ resin, polycarbonate resin, polyacetal resin, polyamide resin, (2) phenolic resin, melamine resin , thermosetting resins such as urea resins, alkyd resins, epoxy resins, unsaturated 7J seriester resins, (3) natural combs, taloloprene rubber, isoprene-inoptylene copolymer rubber, styrene-butanoene copolymer rubber, butadiene-acrylonitrile copolymer Comb, ethylene-70
Examples include rubbery substances such as lopylene thread copolymer rubber, ethylene-butanoene block copolymer rubber, and urethane comb.

In the present invention, the pace polymer and highly conductive carbon black are contained in a ratio of 100 parts by weight and 5 to 100 parts by weight, respectively. If the highly conductive carbon black is less than 5 parts by weight, the conductivity of the composition cannot be sufficiently increased, and if it exceeds 100 parts by weight, the fluidity will deteriorate, which is not desirable.

To prepare the composition of the present invention, a pace polymer and a highly conductive carbon black are added to a known plasticizer.
Various additives such as fillers, reinforcing agents, antioxidants, heat stabilizers, lubricants, flame retardants, cross-linking agents, cross-linking aids, and ultraviolet absorbers are blended as necessary, and then mixed with a dice-type mixer, Mixing may be carried out using a device such as a continuous kneader having a built-in type mixer, Hen/L mixer, Banbury mixer, Niegoo and Hirotor. When processing the composition of the present invention to make a molded product, it can be used as is, or it can be melted and calcined and used as a pellet, and then directly processed using an extruder, injection molding machine, press molding machine, etc. It can be processed using processing machines such as roll molding machines and rotary molding machines.

The composition of the present invention can be expected to be used in notebooks for preventing static electricity, earths for removing static electricity, belts, communication antennas, planar heating elements, casings for shielding electromagnetic waves, coaxial cables, and films.

Next, a detailed explanation will be given in Examples.

Example 1. Comparative Examples 1 to 3 Production of carbon black Vinyl chloride resin (Denka Kagaku Kogyo Co., Ltd., trade name [Denka Vinyl SS-110SJ]) 30 parts by weight, acetylene black (Denki Kagaku Kogyo Co., Ltd. trade name "Acetylene Blank Powder J)" 100 parts by weight Parts by weight and 180 parts by weight of water were granulated in a mixing granulation machine and dried.This was fed into a N2 gas atmosphere furnace maintained at a temperature of 1300°C and fired for 1 hour to obtain 109 parts by weight of carbon black.

Its physical properties are shown in Table 2.

30 parts by weight of the highly conductive carbon blank obtained by the above method and 100 parts by weight of an ethylene-vinyl acetate copolymer resin (trade name: rNuc-3145J, manufactured by Nippon Unicar Co., Ltd.) were mixed into a 60-cm-sized tube made of Toyo Seiki Seisakusho (trade name: "Lab"). Blast, put it in Graph R-60 and set the blade rotation speed to 6 Orp.
m, The mixture was kneaded for 10 minutes at a temperature of 120°C.

For comparison, the same procedure as in Example 1 was carried out except that the added black was replaced with a commercially available Cargin blank shown in Table 1.

Measured values of these physical properties are shown in Table 2.

Example 2 In the production of the carbon blank of Example 1, polyvinyl acetate emulsion (product name: CH-1000J) was used instead of vinyl chloride resin.
A carbon blank of 105 car weight parts was obtained by carrying out the same process except that 0 car weight parts were used.

Next, a conductive composition was produced in the same manner as in Example 1 except that this carbon blank was used.

These physical properties are shown in Table 2.

Bolifu 0 Robyrene resin (Mitsui Toatsu ■Product name r) instead of fat
The same procedure was carried out except that 100 parts by weight of BJHH-GJ) was used.

For comparison, the same procedure was carried out except that the commercially available carbon black shown in Table 1 was used in the proportion shown in Table 3. These physical properties are shown in Table 3.

Example 4. Comparative Examples 7 to 9 The carbon black obtained in Example 1 and the styrene resin were mixed in the proportions shown in Table 4, and 2,6
-Butyl-4 methylphenol (BHT) 0.5
Parts by weight, trinonylphenyl sulfite (TNP)
) 0.5 Sensitive areas, zinc stearate as a lubricant 1.
0 parts by weight were added and kneaded. Its physical properties are shown in Table 4.

In Table 4, styrene resins A and B are manufactured by Denki Kagaku Kogyo Co., Ltd. A is a highly fluid impact-resistant styrene resin with the trade name rHIs-3J and B is a styrene-butanoene block polymer product name r5TR- 1602J is shown.

For comparison, carbon black shown in Table 1 was used.
The same procedure was carried out except that the formulation shown in the table was used.

Example 5. Comparative Examples 10 to 11 Table 5 shows the results of physical property measurements of compositions obtained by adding and kneading the carbon black obtained in Example 1 to chlorozolene rubber in the proportions shown in Table 5. For comparison, Denka Plaque and Ketjen EC shown in Table 1 were added and kneaded at the blending ratios shown in Table 5.

Table 5 " set Growth thing Discount If heavy amount Department thing sex The following materials were used as shown in Table 5.

(1) Talorosolene rubber...Denki Kagaku Kogyo ■Product name [Denka Chloron 0 Ren Rubber-40J (2) Tsukusera CZ - Inunai Shinkyou Anti-Aging Agent Product name [Tsukusela CZJ (3) Tsukuseller... Sanshin Kagaku ■ Vulcanization Accelerator Trade Name: "Zanzen-22" The physical properties of the carbon black enclosures used in the Examples and Comparative Examples of the present invention and the compositions using these were measured by the following method.

8 Physical properties of carbon blank (111) II...JISK1469 (2) Specific surface properties...BET method (3) Iodine adsorption amount...JISK6221B Physical properties of compositions (1) Volume resistivity ...The obtained corrugations were used to make a flat plate with a thickness of 2mm x length of 70mm x width of 20wn using an injection molding machine (Japan Steel Works V715-75 type screw set automatic injection molding machine) and a test piece. Toshida. The measuring device is a digital multimeter (Takeda Riken ■Product name r
TR-6856j) was used.

(2) Melt flow index...JISK7
210 Measured at temperature 200℃, load 5 K9 (3) Rockwell hardness...JISK-72
02(4) Izot impact value...JISK-71
10(5) Vicat softening point...JIS
K-7206 (6) Breaking strength, elongation...JI
SK-7113 (7) Electrical specific resistance...Japan Rubber Association Standard S ■ 52301-1968 (8mm Mooney viscosity...J I 5K6300
(9) Tensile strength, elongation, hardness, compression set, and rebound modulus all conformed to JIS K6301.

Patent applicant: Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Scope of Claims] (111,000°C or more carbon black obtained by heat treating a mixture of a polymer and/or a bituminous material that essentially becomes carbon at a temperature of 111,000°C or higher, and a pH
is 9 or more, specific surface area is 40-7'Qtyi7'? %
A carbon blank with excellent conductivity characterized by an elementary adsorption amount of 50 to 80 ν·/g. (2) A product obtained by heat-treating a mixture of a polymer and/or a bituminous substance and carbon black that essentially becomes carbon at a temperature of 1000°C or higher, and has a pH of 9 or higher and a specific surface area of 40 to 7.
0yi/2, iodine absorption amount is 50-80 mg/? An electrically conductive composition comprising a carbon blank and a synthetic resin and/or a rubbery substance in a ratio of 5 to 100 parts by weight and 100 parts by weight, respectively.