JPS6088073A - Composition containing highly electrically conductive carbon black - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which is highly electrically conductive, has excellent thermal stability and moldability and gives moldings having excellent appearance, consisting of a synthetic resin or a synthetic rubber and specified electrically conductive carbon black. CONSTITUTION:A liquid kydrocarbon having a C/H ratio by weight of 9 or above (e.g. ethylene heavy end) is fed to a furnace which is operated under such conditions that the temperature is 1,200-1,500 deg.C, the pressure is 10-80kg/cm<2> and steam is fed to the furnace at a rate of 200-800kg per ton of the raw hydrocarbon material, whereby the liquid hydrocarbon is partially oxidized to obtain electrically conductive carbon black (B) having a DBP absorption of 220- 350ml/100g and contg. metallic residue impurity of 0.3wt% or below. 97-30wt% synthetic resin (e.g. PE) or synthetic rubber (e.g. ethylene/propylene rubber) (A), 3-70wt% component B and not more than 60wt% inorg. or org. filler (e.g. mica) (C) are kneaded.

Description

Detailed Description of the Invention The present invention has excellent electrical conductivity, thermal stability, moldability,
This relates to a composition in which the appearance of a molded product has deteriorated.

Synthetic resins and synthetic rubbers are generally non-conductive, but if they can be made conductive, they are expected to be used in many fields where other conductive materials have not been satisfactory. For this reason, various studies have been made to obtain conductive compositions by blending conductive fissies into synthetic resins and synthetic rubbers. Among the conductive materials, carbon black is the most commonly considered, and among them, Touchen Black CA
It is known that KzO (trade name) is most suitable for its characteristics which give it a high degree of electrical conductivity in small amounts. However, since conventional TOUCH EN BLACK has a large amount of impurity metal residue (ash), the highly conductive resin or rubber composition in which it is blended has extremely poor heat aging resistance, and this residue itself causes molded products as "putu". This tends to deteriorate the surface, or the residue induces polymer gel, which deteriorates the appearance of the molded product. In addition, DBP oil absorption, which is greatly related to the conductivity of the composition, is at a high level among carbon blacks and tends to be difficult to disperse in resins or rubber, but due to restrictions in the manufacturing method, the oil absorption is below a certain level. I couldn't get anything in quantity.

Therefore, compared to conductive resin or rubber compositions containing conductive carbon black with relatively low DBP oil absorption (for example, acetylene dicarbonate), the appearance of molded products is inferior due to the difference in the dispersibility of carbon black. there were.

The present invention achieves high electrical conductivity, thermal stability, moldability, and moldability by blending a special carpump thick with low ash content and lower DBP oil absorption than conventional synthetic resins or synthetic rubbers. We succeeded in obtaining a composition with excellent appearance.

That is, the present invention involves oxidizing a) a) 97 to 30% by weight of a synthetic resin or synthetic rubber, and (b) a liquid hydrocarbon in the presence of molecular oxygen and water vapor in a furnace to produce a synthetic gas. At the same time, per K for producing conductive carbon black, the carbon atom/hydrogen atom weight ratio of the liquid hydrocarbon is 9 or more, the furnace temperature range is 1200 to 1500°C, and the furnace pressure is 10
~80Kg/d, obtained by operating under conditions where the amount of steam supplied into the furnace is 200 to 800 particles per ton of the hydrocarbon, and the amount of DBPWJL oil is 220m7/100f or more and less than 350rttl/100f, and there are no impurity metals. 0 residue
．． The present invention is a highly conductive carbon black composition characterized by comprising 3 to 70% by weight of conductive carbon black of 3% by weight or less.

The composition of the present invention has a high electrical conductivity level, excellent molding processability, excellent molded product appearance, and has dramatically improved stability such as heat aging resistance, and has extremely high industrial applicability.

Among the above-mentioned (Al-compounded synthetic resins or synthetic rubbers) that can be used in the present invention, thermoplastic resins or thermosetting resins are used as the synthetic resins.As the thermoplastic resins, low density, high density or linear low density Polyethylene, polypropylene, polyα-olefins such as propylene-ethylene bulk or random copolymers, polystyrene, acrylonitrile-butadiene-styrene terpolymers,
Acrylic resins such as polymethyl methacrylate, polyvinyl halides such as polyvinyl chloride, polyamides such as nylon 6, nylon 66, and nylon 12, saturated polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyethers such as polyphenylene oxide, α-olefins such as polysulfone, polyphenylene sulfide, polyvinylidene fluoride, polytetrafluoroethylene, ethylene/vinyl acetate copolymer, ethylene/acrylic acid or its ester copolymer, ethylene/methacrylic acid or its ester copolymer, etc.
Modified resins such as vinyl monomer copolymers, maleic anhydride-modified polypropylene, maleic anhydride-modified polyethylene, maleic anhydride-modified polystyrene, and vinylsilane-modified polypropylene, vinylsilane-modified polyethylene, hydrogenated products of styrene-butadiene block copolymers, etc. may be used alone or in mixtures.

Thermosetting resins include epoxy resin, phenol resin,
Unsaturated polyester resins, melamine resins, polyurethanes, etc. may be used alone or in mixtures.

Further, as the synthetic rubber, ethylene/propylene rubber, styrene/butadiene rubber, imprene rubber, etc. may be used alone or as a mixture.

2,6-di-t-butyl- for synthetic resin or synthetic rubber
4-methylphenol, 1,1,3-tri(2-methyl-4-hydroxy-5-t-butylphenyl)butane, tetrakis[methylene(3,5-di-t-butyl-4
-Hydroxyhydrocinnamate)] In addition to stabilizers such as phenolic antioxidants such as methane, sulfur antioxidants such as dilauryl-thio-diglopionic acid ester, and distearyl-thio-dipropionic acid ester. UV absorbers, neutralizers, lubricants, etc. can be added to the product.

On the other hand, the carbon black as the component (b) used in the present invention is produced by "a process in which liquid hydrocarbons are subjected to a partial oxidation reaction in the presence of molecular oxygen and water vapor in a furnace to produce conductive carbon black at the same time as synthesis gasification." At b1, the carbon atom/hydrogen atom weight ratio of the liquid hydrocarbon is 9 or more, the furnace temperature range is 1200 to 1500°C, and the furnace pressure is 10 to 8.
0KII/cf11 is a special product produced by a method for producing conductive carbon black characterized by operating under the condition that the amount of steam supplied into the furnace is 200 to 5ooKf per ton of said hydrocarbon. .

The liquid hydrocarbons used here are C heavy oil, A heavy oil, naphtha pyrolysis oil (ethylene heavy end), and liquid hydrocarbons made by mixing carbon black with aromatic liquid hydrocarbons (
There are mixed oils such as carbon oil), mixed oils made by mixing aromatic liquid hydrocarbons with C heavy oil, etc. Among these, the ratio of the weight composition of carbon atoms and hydrogen atoms determined by elemental analysis (
Liquid hydrocarbons having a carbon atom/hydrogen atom ratio of 9 or more, such as ethylene heavy end, carbon oil, and mixed oil in which aromatic liquid hydrocarbons are mixed with C heavy oil, etc., are preferred. Furthermore, especially when the weight composition ratio of carbon atoms/hydrogen atoms is 1
Two or more, for example, ethylene heavy end, carbon oil, etc. are preferred because they can particularly reduce the ash content in the resulting carbon black. The weight ratio of carbon atoms/hydrogen atoms is 9
If it is less than that, even if the processing conditions in the furnace are changed, the DBP oil absorption of the carpump thick will be markedly reduced, and the yield will be small, making it difficult to maintain the desired production of carbon black. The above-mentioned raw material liquid hydrocarbon may be solid even if its carbon atom/hydrogen atom weight ratio is 9 or more or less, or it may be a high viscosity liquid hydrocarbon or carbon oil. It is not preferable to use such a material that it becomes difficult to supply the material to the furnace. That is, the feedstock hydrocarbons fed into the furnace are in liquid form and have a viscosity of 3 when fed.
It is preferable that it is less than °cst.

As for specific operating conditions, the furnace temperature in the furnace for performing the partial oxidation reaction is 1200 to 1500°C, preferably 1300 to 1500°C.
It is operated at 1450°C, the furnace pressure is 10 to 80 Kf/d, preferably 25 to 80 Kf/d, and the amount of steam supplied into the furnace is 200 to 5oo Kf, preferably 300 to 800 Kg per ton of raw material hydrocarbon. Ru. By satisfying these operating conditions and the characteristics of the feedstock hydrocarbon at the same time, it is possible to obtain a product that has excellent electrical conductivity, has a limited DBP oil absorption, and has a low ash content, which could not be achieved with conventionally known conditions. It has become possible to produce carbon black in good yields.

The conductive carbon black applied to the composition of the present invention is obtained by the above-mentioned new manufacturing method, and has a DBP oil absorption of 200 mJ/100F or more and 350 rrt//100
less than 9, preferably 250m//100 to more than 320m
//100f or less, impurity metal residue (ash content) is 0
．． 3 weight or less.

Here, DBP oil absorption is JIS-6221-1970.
According to the measurement method.

Partial oxidation methods using liquid hydrocarbons as raw materials include the shell gasification process and Texaco gasification process, which react the hydrocarbons with molecular oxygen and water vapor in a furnace to produce synthesis gas and at the same time produce carbon black as a by-product. AKZO's "Ketjen Black" is known as carbon black produced by a shell gasification process.

Carbon black manufactured by the conventional partial oxidation method using liquid hydrocarbon as a raw material has a high ash content as seen in Ketjen Black, and does not have a certain level of DBP oil absorption. There were also limits to the dispersibility in resins or rubbers.

On the other hand, the carbon black produced according to the present invention at a specific furnace temperature, furnace pressure, and amount of steam supplied to the furnace has a low ash content and a lower DBP oil absorption than the conventional carbon black.

The blending ratio of the above components (a) and (b) in the composition of the present invention is 97 to 30% of the synthetic resin or synthetic rubber of component (a).
% by weight and 3 to 70% by weight of the novel conductive carbon black as component (b). If the blending ratio of synthetic resin or synthetic rubber is less than 3034% by weight, the moldability of the composition will be poor, and if it exceeds 97% by weight, high electrical conductivity cannot be expected.

The specific blending amount is determined depending on the required performance for each application.

The composition of the present invention may further contain an inorganic or organic filler, preferably 60% by weight or less, in addition to the synthetic resin or synthetic rubber and the novel conductive carbon black. Inorganic fillers include calcium carbonate, talc, yaika, galanu fiber, wollastonite, glass beads, magnesium hydroxide, aluminum hydroxide, barium sulfate, graphite, molybdenum disulfide, carbon fiber, silica, silicon carbide fiber, aluminum fiber, Brass fibers, stainless steel fibers, aluminum flakes, aluminum powder, barium ferrite, strontium ferrite, etc. can be used. As the organic fiber 2-, wood flour, aromatic polyamide fiber, etc. can be used.

The composition of the present invention can be used in batch-type kneading machines such as Banbury mixers, rolls, and two-bender plastographs.
- It can be obtained using a continuous extruder such as a screw extruder or a twin screw extruder. The order of blending is not particularly limited,
In addition to the method of mixing and kneading the mixture at once, it is also possible to first knead a part of the synthetic resin or synthetic rubber with carbon black in a batch-type or continuous-type extruder, and then mix the mixture and the synthetic resin. Alternatively, it can also be kneaded with the remainder of the synthetic rubber.

The composition of the present invention achieves the following unexpected effects by using a specific conductive carbon black.

(1) Durability such as heat aging resistance of the composition is significantly improved.

(2) The dispersibility in synthetic resin or synthetic rubber is improved and the appearance of the molded product is good.

(3) Compared to conventional TOUCH EN BLACK, the melt viscosity of the blended resin or rubber is low and the fluidity is excellent at the same filling standard, resulting in good moldability. Furthermore, compared to acetylene black and general conductive furnace black, the amount of filling required to provide a predetermined electrical conductivity can be significantly reduced, resulting in superior strength and moldability.

(4) Although the DBP oil absorption, which is an indicator of conductivity, is lower than that of conventional Touchen Black, it exhibits high conductivity.

Reference Example 1 The properties of the raw material liquid hydrocarbon are: Initial distillation temperature: 180-190°C 10-chi distillation temperature: 205-215°C 50-chi distillation temperature: 250-260°C 97-chi distillate temperature: 320-340°C Viscosity (80°C) Electrically conductive carbon black 1:c- was used in the furnace of the shell gasification process using an ethylene heavy end with a carbon atom/hydrogen atom (weight ratio) of approximately 12.5. 3015/c1!
The amount of steam supplied to the furnace is a relative to the feedstock hydrocarbon.
When the reaction was carried out under the conditions of methane concentration 0.3 volume and ooK9/), the DBP oil absorption was 290 m/1001. Carbon black with an ash content of 0.02 weight was obtained.

Conductive carbon black 2: C-2 Furnace temperature 1350°C, furnace pressure 3oKg/l-d
The amount of steam supplied to the furnace is 3 for the raw material hydrocarbon.
The reaction was carried out under conditions of 0.00 Kg/) and a methane concentration of 0.7 volume to obtain carbon black with a DBP oil absorption of 230 m/1001 and an ash content of 0.01% by weight.

Conductive carbon black 3: C-3 9/crI at a furnace temperature of 1400°C and a furnace pressure of 30
The amount of steam supplied to the furnace is 4 to the feedstock hydrocarbon.
The reaction was carried out under conditions of 0.00 Kf/ton and a methane concentration of 0.3 volume to obtain carbon black having a DBP oil absorption of 320 m//100 f/1 and an ash content of 0.1 wt.

Conductive carbon black 4: C-4 The amount of steam supplied to the furnace is 60% relative to the raw material hydrocarbon.
Carbon black with DBPrJEl, oil amount of 418al/1002, and ash content of 0.05% by weight was obtained in the same manner as in the production of C-3 except that the carbon black was changed to 0.9/).

Conductive carbon black 5: C-5 The amount of steam supplied to the furnace is 73% relative to the raw material hydrocarbon.
DBP oil absorption 490g/100t1 ash content 0.0
7% by weight of carbon black was obtained.

Example 1 Polypropylene (MI4) and a predetermined amount of conductive carbon black 1 (C-1) of Reference Example 1 were kneaded in a Brabender Plastograph at 230°C and a rotor rotation speed of 6 Orpm for 5 minutes. A press sheet with a thickness of 2 m was produced using the compound. Using this sheet, the volume resistivity was measured by the Wheatstone bridge method of SRI S standard 2301. For comparison, measurements were also made using conventional Ketjen Black. The results are shown in Figure 1.

As is clear from Figure 1, in poly:propylene systems, Ketjen black (DBP oil absorption 3, 0 to 36
It was found that the same excellent conductivity level was exhibited despite the small size.

Example 2 Various conductive carbon blacks with different DBP oil absorption amounts were added to polypropylene (MI4) and the volume resistivity of the composition was 1.0.
The MFR (which is one guideline for processability) for a composition filled in a predetermined amount so that it becomes ~1.5×10°Ω-m
2 3 0℃, 10.73? load) was measured. The results are shown in Table 1.

Table 1 shows that the composition of the present invention exhibits excellent fluidity at the same conductivity level, suggesting that it has considerable superiority in actual processing.

First, 0.1 part by weight of 2,2'-methylenebis(6-tert-butyl-3-methylphenol) was added to 100 volumes of the above composition to prepare a press sheet with a thickness of 0.5 mm. The sheet was placed in a gear oven at 150° C. and the time at which it began to deteriorate was measured. The results are shown in Table 2.

As is clear from Table 2, the composition of the present invention exhibits extremely good heat aging resistance, and it is understood that the impurity metal residue (ash content) in carbon black has a particularly large effect. It was done.

Example 3 Low density polyethylene (MI8.0, density 0.9 1 g
) and the conductive carbon black i of Reference Example 1 (c-i
) or 3 A predetermined amount of (C-3) was heated to 140°C using a Pravaderplastograph at 5 rotor revolutions.

A press sheet with a thickness of 2 mm was produced using the compound obtained by kneading the mixture at rpm for 5 minutes.

The results of measuring the volume resistivity in the same manner as in Example 1 are shown in FIG.

As a comparative example, the volume resistivity of a compound containing 20 parts by weight of acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) was similarly determined by Keiichi, but there was a large difference in the conductivity level at 1070 m or more. It turns out that there is something.

In addition, the MFR of the composition of the L distribution example and the blended composition of conductive carbon black 5 (C-s) as a comparative example were measured. The results are shown in Table 3.

Table 3 Next, the above composition was uniformly kneaded at 150°C using a twin-screw extruder to obtain a compound.

Using this compound, a 50 m diameter Ifin molding machine (screw L/D = 24, die slip width 0.75 am,
Spider spiral type), molding temperature 180℃,
Film formability was examined under the condition of screw rotation of 42 rpm. The results are shown in Table 4.

Table 4 The high DBP conductive carbon black compound system had an increased extrusion torque, insufficient spreadability, and the occurrence of surging, making it difficult to form a thin film of 100 microns or less. Moreover, the surface of the obtained film had many "bubbles" with a diameter of 25 to 100 μm, and the appearance was extremely poor.

Example 4 Nylon 12 (Daicel Huls <Diamide L18
01>) to the conductive car pump of Reference Example 1: 1ly7ri1
(C-1) OJ: and DB as a comparison with the same 3 (C-3)
A compound was obtained by kneading a predetermined amount of P oil absorption 490 m//100 t (D conductive carbon black 5' (C-5) in a Brabender planetograph for 5 minutes at 220°C and a rotor rotation speed of 7 Orpm. Using this compound, the volume resistivity was measured in the same manner as in Example 1. The results are shown in FIG.

In addition, the melt viscosity (
200° C., nozzle L/D=0.5/1). The results are shown in Figure 4.

As is clear from FIGS. 3 and 4, the composition of the present invention has a conductivity level comparable to that of a conductive carbon compound system with high DBP oil absorption (10 to 101Ω-σ
Example 5 Ethylene-vinyl acetate copolymer (EvA; vinyl acetate content 20%, M I 12.0) , density 0.940) of the conductive carbon black of Reference Example 1. 2.3 and for comparison, 12 parts by weight of acetylene black (Denka Black, Denki Kagaku Kogyo Co., Ltd.) was added to 100 parts by weight of resin, and the mixture was heated at 150°C and 60 rpm in a Prabender Plastograph. A compound was obtained by kneading for a minute. The volume resistivity of the compound was measured in the same manner as in Example 1. The results are shown in Figure 5.

As is clear from FIG. 5, a new fact has been discovered that the electrical conductivity level of DBP oil absorption in the electrically conductive carbon black blended system of the present invention is significantly different from that of acetylene black.

Example 6 The temperature dependence of volume resistivity was measured for the EVA of Example 5 and the conductive carbon black 1 or 2 of Reference Example 1 or the acetylene black blend.

The results are shown in Figure 6.

From FIG. 6, it can be seen that the composition of the present invention not only has a small amount of carbon black additive for imparting conductivity, but also
It can be seen that the conductivity is extremely stable with respect to the environmental temperature.

In addition, for these two carbon black systems, the blending ratio at which the volume resistivity of the compositions is approximately at the same level, that is, the conductive carbon black 1 of Reference Example 1 is 12 parts by weight/EVA1
00 heavy bone part, acetylene black 55 parts by weight/EVAI
o Melt viscosity (120°C,
Nozzle L/D = 1 inch10. Oa inch) was measured. The results are shown in FIG. 7. Example 7 100 parts by weight of EVA used in Example 5, 1.0 part of zinc stearate and 1 part of the conductive carbon black of Reference Example 1 (
C-1) Blending 12 parts by weight, 60 parts by weight of acetylene black, or 12 parts by weight of Touchen Black, respectively,
A compound was obtained by mixing in a roll mixing machine at 120° C. for 10 minutes. A press sheet having a thickness of 1 thick was prepared using the compound, and the tensile strength and elongation of this sheet was measured after 100 hours had passed in a 150° C. gear oven. 5th result
Shown in the table.

(Left below) Example 8 Hydrogenated derivative of styrene-butadiene block copolymer rubber (Shell Co., Ltd. Slayton Q-1652, styrene/butadiene block copolymer rubber)
Rubber ratio: z9/7x) and ethylene-propylene copolymer rubber (propylene content 2SZoo°C).

weight tL%, Mooney viscosity, 75) 90 weight% 1+4 and the conductive carbon black 1 (C-1) of Reference Example 1. Furthermore, as a comparison, conductive carbon black 5 (C-5) was added to 1
A compound was obtained by kneading 0% by weight of zinc stearate and 1% by weight of zinc stearate at 200° C. for 10 minutes using a roll mixer. The volume resistivity of the composition was measured using a cough compound in the same manner as in Example 1, while a circular shape with a diameter of 3 mm was measured using a 40 diameter extruder in order to check the dispersibility of carbon black in rubber. The strands were extrusion molded at 240° C., and the surface condition of the molded product (the amount of surface unevenness) was measured.

The results are shown in Table 6.

(Margin below) Table 6 Example 9 Ephoxy resin (Epicoat ◆828 manufactured by Yuka Shell Co., Ltd.) 6
7 Heavy bones and hardening agent (Epicure “302” manufactured by Shell Chemical Co., Ltd.)
5) 33 parts by weight and conductive carbon black 3 of Reference Example 1
(C-3) or 10 parts by weight were thoroughly mixed in an automatic stirring mortar. Next, a glass plate was masked with paper tape and the mixed resin was applied with a glass rod.
A coating film with a thickness of 100 microns was formed. The volume resistivity of this coating film was measured by the Wheatstone bridge method of 5RIS standard 23o1. The results are shown in Table 7. A system containing acetylene black or conductive carbon black 5 (C-5) with a ratio of 1 is also shown.

Table 7 *Uniform coating could not be achieved due to poor carbon dispersibility.

[Brief explanation of drawings]

Figures 1.2.3.5 and 6 show Example 1.3, respectively.
．． 4.5 and 6 are drawings showing the volume resistivity of each composition. Moreover, FIGS. 4 and 7 are drawings showing the melt viscosity of each composition of Examples 4 and 6. Figure 1: Force - Ball rack included (weight Z) Force - Ball rack included! (Weight parts/PE100 parts by weight)
Figure 5 Oil absorption amount of Carposi Black (m + 0091 temperature (6
C) Figure 7 Shear rate (sec=)

Claims (1)

[Claims] (a) 97 to 30% by weight of synthetic resin or synthetic rubber, and (b) liquid hydrocarbon is subjected to a partial oxidation reaction in the presence of molecular oxygen and water vapor in a furnace to simultaneously convert it into synthetic gas and conductive carbon black. In producing the liquid hydrocarbon, the carbon atom/hydrogen atom weight ratio is 9 or more, the furnace temperature range is 1200 to 1500°C, and the furnace pressure is 10 to
80~/a/l, the amount of steam supplied into the furnace is 200~800t per ton of the hydrocarbon, and the DBP oil absorption is 220In! Impurity metal residue is 0.7100 f or more and 350 m//less than 100 IF.
3-70% by weight of conductive carbon black up to 3% by weight
A highly conductive carbon black composition characterized by comprising: