JP3681266B2 - Method for producing particulate carbon black - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing particulate carbon black which is excellent in dispersibility in resins, rubbers and the like and has little dust.
[0002]
[Prior art]
Since carbon black is scattering, it is often used by granulation in order to improve handling during transportation and blending / kneading with resin / rubber. The properties required for the granulated product are high grain hardness, uniform particle diameter, and high bulk density.
[0003]
Conventionally, as a granulation method of carbon black satisfying the above required characteristics, a horizontal agitation granulation comprising a rotating cylinder in which raw powder and binder water are spirally arranged with a plurality of protruding pins at predetermined intervals. It is known to dry after putting into a machine and wet granulating. As the binder, a water-soluble polymer substance or a surfactant is used.
[0004]
Any of the above granulation methods is a single mixing granulation of the raw powder and the binder water, and the density of the obtained granulated particles is uniform from the central part to the outer part, and when the grain hardness is increased. Was not easily broken or pulverized and the dispersibility in resin, rubber, etc. was lowered.
[0005]
[Problems to be solved by the invention]
Carbon black is used as a rubber reinforcing material, a resin colorant / conductivity imparting agent, a color pigment / conductive paint for ink or paint, and the like. In order to make the most of these functions, first, it is necessary to ensure quantitativeness in handling during transportation, blending and kneading, and to have less dust. Second, there is no aggregation of particles and the particles are uniformly dispersed. In order to satisfy the first characteristic, it is necessary to have a large bulk density and a high grain hardness. However, when such a material is used for rubber or resin, poor dispersion in the vehicle occurs. However, there are problems such as a decrease in rubber physical properties, an increase in kneading power, deterioration in extrusion characteristics, and poor conductivity in the resin.
[0006]
The object of the present invention is, in view of the above, because the particle hardness is large, it is easy to handle during transportation or blending / kneading with rubber / resin, etc., has little dust, and has excellent dispersibility in the vehicle. It is to provide a method for producing particulate carbon black .
[0007]
Delete [0008]
[Means for Solving the Problems]
That is, in the present invention, after stirring the first stage of granulation by blending 150 to 300 parts by weight of binder water having a concentration of 0.05 to 0.3% by weight with respect to 100 parts by weight of carbon black raw powder, The carbon black raw powder used in the first stage is mixed with 5 to 20 parts by weight of the carbon black raw powder having the same or different characteristics with respect to 100 parts by weight of the granulated product, and the second stage stirring granulation is performed. This is a method for producing particulate carbon black, in which a carbon black coating layer serving as a shell portion is formed on the surface of carbon black constituting the core portion with carbon black having the same or different characteristics as the carbon black. In the present invention, the carbon black in the core part and the shell part are both acetylene black, the carbon black in the core part and the shell part are both furnace black, the carbon black in the core part is acetylene black, and the carbon in the shell part. It is preferable that the black is a carbon black other than acetylene black, the carbon black in the core portion is a carbon black other than acetylene black, and the carbon black in the shell portion is acetylene black .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0010]
The particulate carbon black produced according to the present invention has a structural structure in which a carbon black coating layer is formed on the surface of the granular carbon black, in other words, the granular carbon black is the core portion, and the carbon black coating layer. It is characterized by having a core-shell structure like a “boiled egg” with a shell portion as the shell portion.
[0011]
Particulate carbon black produced by the present invention is constituted by carbon black having same or different properties of carbon black core and the shell, if Shimese the example, (1) the same type of acetylene black In which the core and shell are composed, (2) the core and shell are composed of carbon black other than the same kind of acetylene black, and (3) acetylene black having different properties such as liquid absorbency and specific surface area (4) Containing the core part and the shell part with carbon black other than acetylene black such as furnace black having different properties such as liquid absorbency and specific surface area. The core and shell are made of different types of carbon black, for example, the core is acetylene black and the shell is furnace Carbon black other than acetylene black such as rack, or carbon black other than acetylene black such as furnace black in the core portion and acetylene black in the shell portion, etc.
[0012]
Examples of the binder used in the present invention include lignin sulfonate, molasses, tall oil, polyvinyl alcohol (PVA), polyethylene glycol (PEG), carboxymethyl cellulose (CMC), starch, and other water-soluble polymer substances and surfactants. It is. The amount used is about 0.5 to 2% by weight with respect to water in the case of normal one-time mixing granulation, but in the present invention, it is 0.05 to 0.3 by multistage granulation. It becomes a small amount of about wt%.
[0013]
The average particle size of the particulate carbon black produced in the present invention is about 0.4 to 2.0 mm, the core portion has a diameter of about 0.2 to 1.5 mm, the shell portion has a thickness of about 0.2 to 1.5 mm, It is preferable that the grain hardness is about 8 to 12 g / piece and the bulk density is about 0.25 to 0.50 g / cm ³ . These characteristics can be adjusted by changing the conditions in the multistage granulation method of the present invention described below.
[0014]
The method for producing particulate carbon black of the present invention is a multistage granulation method of carbon black raw powder. In the first stage of granulation, the concentration is 0.05 to 0.3 with respect to 100 parts by weight of carbon black raw powder. 150 to 300 parts by weight of binder water having a weight % is mixed and granulated with stirring. If the binder water is less than 150 parts by weight, the water necessary for granulation is insufficient and granulation becomes difficult. On the other hand, if it exceeds 300 parts by weight, the granulated particles grow remarkably and become mud, so that the granulator becomes heavy and operation becomes difficult. In the second-stage granulation, 5 to 20 parts by weight of carbon black raw powder having the same or different characteristics as the carbon black raw powder used in the first stage is added to 100 parts by weight of the first-stage granulated product and stirred. Granulate. When the blending amount of the carbon black raw powder in the second stage is less than 5 parts by weight, a shell part is hardly formed, and a granulated product having a non-uniform grain size and a non-uniform grain size is obtained, and more than 20 parts by weight. In addition, the carbon black raw powder becomes excessive and a lot of ungranulated powder is contained in addition to the granulated particles. In any case, it becomes impossible to produce a granulated product having a large grain hardness and bulk density. .
[0015]
In the present invention, it can be a particulate carbon black having a shell portion having two or more layers by repeating the granulation operation, also by changing the amount of carbon black Harakona in granulation of a second stage The grain hardness can be changed.
[0016]
As the carbon black raw powder used in the present invention, acetylene black, furnace black, thermal black, lamp black, channel black, gas black, disk black and the like are used. The particle diameter is 10 to 100 nm.
[0017]
In the multi-stage granulation method in the present invention, the raw powder has a low specific surface area and low structure carbon black having an IV value of about 10 mg / g and a DBP value of about 20 ml / 100 g, and an IV value of about 1000 mg / g and a DBP value. Is suitable for carbon black having a high specific surface area of about 400 ml / 100 g and a high structure.
[0018]
That is, when carbon black with a low specific surface area and low structure is granulated by a conventional method, it is easy to obtain a granulated product with high hardness and high bulk density because of its low liquid absorbency, but these properties are uniform throughout the particle. Therefore, dispersibility in resin, rubber, etc. is poor. On the other hand, according to the multistage granulation method as in the present invention, the amount of the binder necessary for increasing the grain hardness can be reduced and granulated into a core-shell structure. After the layer is broken by kneading and stirring with the vehicle, the inner core portion is a soft layer, so that the layer is quickly dispersed in resin, rubber, and the like.
[0019]
On the other hand, in the case of carbon black with a high specific surface area and a high structure, the raw powder is a granulated product with low hardness and low bulk density because the raw powder is highly absorbent and elastic. It was necessary to increase the amount of binder. An increase in the amount of the binder is not desirable because it causes a decrease in dispersibility and an increase in contamination with impurities. On the other hand, in the multistage granulation method as in the present invention, in the first stage of agitation granulation, the carbon black raw powder is plasticized, that is, granulated by adding excess binder water rather than granulating, In the second stage of agitation granulation, the same or different carbon black raw powder is added to the granulated product containing excess binder water and the water content is adjusted for granulation. Compared with conventional systems, it is possible to obtain particulate carbon black having high purity, high hardness, high bulk density and excellent dispersibility.
[0020]
Particulate carbon black produced in the present invention is easy to handle because of its large particle hardness and bulk density, and the shell part is dense, and there are no gaps between the core part and the shell part. The core part itself is soft, and if the shell part is broken, the core part is easily powdered, so that the dispersibility in rubber, resin, etc. is good. Accordingly, it is possible to produce rubber and / or resin compositions, paints, inks, and the like that are excellent in mechanical properties, conductivity, light transmittance, and the like. Further, it can also be used as a battery, an electrode, an adsorbent, a catalyst, a conductivity imparting agent and the like.
[0021]
Rubbers used include natural rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, butyl rubber, acrylic rubber, ethylene propylene rubber, ethylene propylene terpolymer, copolymer rubber of ethylene and α-olefin, silicone rubber, fluoro rubber, polyester. Thermoplastic elastomers such as chloroprene rubber, polybutadiene, hydrin rubber, and chlorosulfonated polyethylene.
[0022]
Resin for resin composition / paint / ink includes bisphenol type epoxy resin, phenol novolac type epoxy resin, alicyclic type epoxy resin, chlorine ring type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, Epoxy resins such as halogenated epoxy resins, polybenzimidazole, polybenzoxazole, polybenzthiazole, polyoxadiazole, polypyrazole, polyquinoxaline, polyquinazolinedione, polybenzoxazinone, polyindrone, polyquinazolone, polyindoxyl, silicon Resin, silicon-epoxy resin, phenol resin, melamine resin, urea resin, unsaturated polyester, polyamino bismaleimide, diallyl phthalate resin, fluororesin, TPX resin, polyimi , Polyamides such as polyamideimide, polyetherimide, amorphous nylon, polyesters such as polybutyl terephthalate and polyethylene terephthalate, polyphenylene sulfide, modified polyphenylene ether, polyarylate, wholly aromatic polyester, polysulfone, liquid crystal polymer, polyether ether ketone, poly Ether sulfone, polycarbonate, maleimide modified resin, ABS resin, AAS (acrylonitrile / acrylic rubber / styrene) resin, AES (acrylonitrile / ethylene / propylene / diene rubber / styrene) resin, polyethylene, polypropylene, ethylene vinyl acetate, ethyl acrylate, etc. Copolymer resin and the like.
[0023]
The physical properties described herein were measured according to the following.
(1) Particle diameter: An average value obtained by photographing carbon black powder with a transmission electron microscope (manufactured by Hitachi, Ltd.) at a magnification of 50,000 and measuring 100 particle diameters.
(2) Grain hardness; JIS K 6221
(3) Bulk density; JIS K 1469
(4) Disintegration degree: After putting 10 g of particulate carbon black into a 100 ml measuring cylinder and measuring the volume, 20 g of that and 120 g of polystyrene pellets (3 mm square) were placed in a V-type mixer (micro type) having a height of 20 cm and a diameter of 7 cm. The mixture was placed in a fluoroscopic mixer (manufactured by Tsutsui Rika Kikai Co., Ltd.) and crushed at 45 rpm for 20 minutes. After pulverization, the mixture was passed through a sieve (2 mm), and carbon black was collected. Then, 10 g of the carbon black was placed in a 100 ml graduated cylinder and the volume was measured. The volume change before and after crushing was defined as the crushing degree.
[0024]
(5) Number of agglomerated particles: 30 parts by weight of particulate carbon black and 100 parts by weight of EVA resin (trade name “NUC3145” manufactured by Nihon Unicar Co., Ltd.) R-60 ") and kneaded for 10 minutes at a blade rotation speed of 30 rpm and a temperature of 120 ° C. This kneaded product was press-molded under heating at 180 ° C. to prepare a sample having a thickness of 1 mm. This sample was cut to 1 μm with a microtome, the dispersion state of carbon black was observed with a 100 × optical microscope, and the number of undispersed aggregated particles per 1 cm ² was measured.
(6) Particle cross-sectional observation: The carbon black particles were cut with a razor and observed with a scanning electron microscope (trade name “JSM-840” manufactured by JEOL) at a magnification of 40 times.
[0025]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.
[0026]
Example 1
Furnace Black (Cabot “BLACK PEARLS1100”, particle size 13 nm) 100 parts by weight of 300 parts by weight of binder water with a PEG (polymerization degree 300) concentration of 0.1% by weight is blended with a high-speed Henschel mixer (trade name, manufactured by Mitsui Miike Manufacturing Co., Ltd.) The mixture was stirred for 5 minutes at a stirring speed of 1100 rpm with “10B type” (volume: 9 liters), and the first stage of stirring granulation was performed. Next, 5 parts by weight of Ketjen black (Ketjen Black International Co., Ltd., particle size: 27 nm) is blended with 100 parts by weight of the obtained granulated product, and further stirred for 5 minutes at a stirring speed of 1100 rpm to be stirred in the second stage. After granulating, it was dried for 20 hours in a drier kept at a temperature of 150 ° C. to produce particulate carbon black of the present invention.
[0027]
Example 2
Except that the binder water having a molasses concentration of 0.2% by weight was 150 parts by weight in the first stage and the blending amount of carbon black in the stirring granulation in the second stage was 20 parts by weight, the same as in Example 1. Particulate carbon black was produced.
[0028]
Example 3
First stage agitation granulation was carried out by blending 100 parts by weight of furnace black (Mitsubishi Chemical "RCF # 10", particle size 86 nm) with 150 parts by weight of binder water having a lignin sulfonate concentration of 0.2% by weight. Thereafter, particulate carbon black was prepared in the same manner as in Example 1 except that 5 parts by weight of another furnace black (Cabot “VULCAN XC72R”, particle size 30 nm) was blended with 100 parts by weight of the obtained granulated product. Manufactured.
[0029]
Example 4
Particulate carbon black was produced in the same manner as in Example 2 except that the blending amount of carbon black in the second stage of agitation granulation was 5 parts by weight.
[0030]
Example 5
After 100 parts by weight of acetylene black (Electrochemical Co., Ltd. “50% press”, particle size 36 nm) is mixed with 300 parts by weight of the binder water of Example 1 and stirring granulation in the first stage, the obtained structure is obtained. Particulate carbon black was produced in the same manner as in Example 1 except that 20 parts by weight of another acetylene black (Denki Kagaku Kogyo "HS-100", particle diameter 48 nm) was blended with 100 parts by weight of the granules.
[0031]
Example 6
After first-stage agitation granulation with acetylene black (Electrochemical Co., Ltd. “50% press”, particle size: 36 nm), furnace black (Cabot Corporation “BLACK PEARLS1100”, particle size: 13 nm) was blended. Particulate carbon black was produced in the same manner as in Example 5 except that step granulation was performed.
[0032]
Example 7
After first-stage agitation granulation with furnace black (Mitsubishi Chemical “RCF # 10”, particle size 86 nm), acetylene black (Electrochemical Co., Ltd. “50% press”, particle size 36 nm) was blended. Particulate carbon black was produced in the same manner as in Example 5 except that the second-stage granulation was performed.
[0033]
Example 8
Particulate carbon black was produced in the same manner as in Example 5 except that the first stage and the second stage of granulation were performed with acetylene black (Electrochemical Co., Ltd. “50% press”, particle size: 36 nm).
[0034]
Example 9
Particulate carbon black was produced in the same manner as in Example 5 except that the first stage and the second stage of granulation were performed using furnace black (Cabot Corporation “BLACK PEARLS1100”, particle size: 13 nm).
[0035]
Comparative Example 1
Particulate carbon black was produced in the same manner as in Example 1 except that the binder water having a PEG (polymerization degree of 300) concentration of 1% by weight was used and granulation was performed without performing the second-stage granulation.
[0036]
Comparative Example 2
Particulate carbon black was produced in the same manner as in Example 2, except that the binder water having a molasses concentration of 1% by weight was used and granulation was performed without performing the second stage granulation.
[0037]
Comparative Example 3
Particulate carbon black was produced in the same manner as in Example 5, except that binder water having a lignin sulfonate concentration of 1% by weight was used and granulation was carried out without carrying out the second stage of granulation.
[0038]
Comparative Example 4
Particulate carbon black was produced in the same manner as in Example 8, except that 1% by weight of PEG (polymerization degree: 300) binder water was used and granulation was performed without performing the second stage of granulation.
[0039]
With respect to the particulate carbon black produced above, the particle hardness, bulk density, degree of pulverization, and number of aggregated particles were measured according to the above. The results are shown in Table 1.
[0040]
[Table 1]
[0041]
From Table 1, the particulate carbon black obtained in Examples 1 to 9 is less dispersible than the particles obtained in Comparative Examples 1 to 4, although the particle hardness and bulk density are the same, and the number of aggregated particles is small. It was excellent.
[0042]
The results of the particle cross-sectional observation of the particulate carbon black obtained in Examples 1 to 9 are the same as those shown in FIG. 1 attached to Japanese Patent Application No. 9-72854. And a core-shell structure in which a carbon black coating layer is formed.
[0043]
【The invention's effect】
The particulate carbon black produced according to the present invention has little dust during pneumatic transportation, blending and kneading into rubber and / or resin, etc., and is excellent in dispersibility in rubber and / or resin. is there.
[0044]
Delete

Claims (5)

After blending 150 to 300 parts by weight of binder water having a concentration of 0.05 to 0.3% by weight with respect to 100 parts by weight of carbon black raw powder and performing the first stage of agitation granulation, 100 parts by weight of the granulated product is obtained. In contrast, 5 to 20 parts by weight of carbon black raw powder having the same or different characteristics as the carbon black raw powder used in the first stage is blended, and the second stage stirring granulation is performed to constitute the core part. A method for producing particulate carbon black, wherein a carbon black coating layer serving as a shell portion is formed on the surface of carbon black with carbon black having the same or different characteristics as the carbon black. 2. The method for producing particulate carbon black according to claim 1, wherein the carbon black in the core portion and the shell portion are both acetylene black . 2. The method for producing particulate carbon black according to claim 1, wherein the carbon black in the core part and the shell part are both furnace black . 2. The method for producing particulate carbon black according to claim 1, wherein the carbon black in the core is acetylene black and the carbon black in the shell is carbon black other than acetylene black . 2. The method for producing particulate carbon black according to claim 1, wherein the carbon black in the core portion is carbon black other than acetylene black, and the carbon black in the shell portion is acetylene black .