JPH023826B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for producing carbon black from which fine grit has been removed. In detail, carbon black is furnace black produced from an oil furnace reactor and by-product carbon black produced from a heavy oil partial oxidation furnace, and carbon black is manufactured by removing grit mixed in these carbon blacks. Regarding how to. In general, carbon black is widely used as a reinforcing agent for resins, pigments in paints and inks, rubber, and as an electrical conductivity imparting material for resins, rubber, and the like. Usually, to blend carbon black into resin or rubber, a Banbury mixer, mixing roll,
Henshil mixers, pressure kneaders, extruders, and the like are used, and extruders in particular are widely used for various resins. Further, press molding, injection molding, extrusion molding, etc. are used for the molding process. However, when kneading or molding resin and rubber using an extruder, the screen in front of the breaker plate of the extruder is clogged with grit mixed in with the carbon black, reducing production efficiency and causing problems with extrusion-molded products. Due to the grit on the surface, small convex particles are generated all over the surface, causing many problems such as a drastic reduction in product value. It is said that the sources of grit mixed in carbon black are coke grains generated in the furnace, flakes of furnace bricks, and iron powder generated from equipment such as heat exchangers at the same time as carbon black is generated. There is. Conventionally, to separate and remove this grit from carbon black, methods have been used either alone or in combination, such as installing a cyclone with a slow flow rate after a heat exchanger, or removing magnetic grit with a magnetic separator. There is. However, the ability to remove grit by the above-mentioned method is limited to a 44μ sieve residue of about 10 ^{-2 to -3} % at most. This level of removal cannot actually prevent clogging of the extruder screen or deterioration of the extrusion surface. Therefore, in order to solve the above problems, the inventors of the present invention conducted extensive research based on the idea that impurities such as grit should be removed as much as possible, and found that the conventional cyclone method Because of the limitations of this method, we decided to adopt a fundamentally different sieving method. However, with conventional sieving methods, it has been impossible to pass carbon black through a 44μ sieve to remove grit on an industrial scale. The carbon black suspension is adjusted to a viscosity range and passed through a vibrating sieve with vibration and amplitude in a specific range, and an organic solvent is added to the passed carbon black suspension to form an organic solvent phase and an aqueous phase, which are then stirred. By transferring the carbon black from the aqueous phase to the organic solvent phase, and then separating and removing the water and solvent, grit can be reduced to the point where it becomes undetectable in the sieve residue (44μ mesh). The present invention was achieved by discovering that the clogging of the extruder screen and the extrusion surface can be greatly improved. The purpose of the present invention is to provide an industrially advantageous method for producing carbon black from which minute and fine grit has been removed. ~
Create a liquid in the range of 100 poise, then frequency
A vibrating sieve with a vibration width of 1 to 7 mm is used at 1500 to 3000 times/second, with a sieve mesh suitable for the grit to be removed, and an organic solvent is added to the suspension under the sieve to separate the organic solvent phase. It is produced by forming an aqueous phase and stirring these to transfer the carbon black from the aqueous phase to an organic solvent phase, and then separating and removing the water and solvent. Next, the present invention will be explained in detail. The method for producing carbon black from which fine grit has been removed according to the present invention is a combination of three steps: a suspension step in which carbon black and water are uniformly suspended, a sieving step, and a recovery step in which carbon black is recovered from an aqueous phase. It is established by The first step of the invention requires uniform suspension of carbon black and water. The viscosity of this suspension also varies depending on the amount of carbon black added and the type of carbon black. The relationship between the amount of carbon black added to water and the viscosity of the suspension is such that the viscosity changes exponentially with the amount added. Therefore, when adjusting the viscosity of the suspension to 1 to 100 poise, the relationship between the water absorption amount of various carbon blacks, the amount added to water, and the viscosity at that time is determined in advance. For any given carbon black, the amount of carbon black added for a desired viscosity was determined from the water absorption amount obtained by measuring only the water absorption amount and the relationship diagram obtained above. Carbon blacks that can be used include carbon blacks for coloring pigments and rubber reinforcement manufactured by the furnace method, conductive carbon blacks, and by-product carbon blacks (heavy oil,
Various known materials such as carbon black, which is produced as a by-product when carbon monoxide gas and hydrogen gas are produced by partially oxidizing hydrocarbons such as ethylene bottom oil in the presence of oxygen and water vapor, can be used. Examples of carbon black for coloring pigments include Mitsubishi Carbon Black (trademark of Mitsubishi Chemical Industries, Ltd.), #2400B, #2300, #2200B, #1000, #
900, MCF−88, MA−600, MA−100, MA−
8, MA-11, #50, #52, #55, #40, #45,
There are #30, #32, #33, etc. Examples of carbon black for rubber include Dia Black (trademark of Mitsubishi Chemical Industries, Ltd.) A;
LI, I, II, N339, LH, H, SH, HA, SF,
In addition, examples of conductive carbon blacks include Ketschen Black EC (trademark of Akzochemy, Netherlands), Vulcan×C-72 (trademark of Cavo, Inc., USA), and the above-mentioned carbon blacks for color pigments and rubber. is reacted with carbon dioxide or water vapor at high temperatures, usually over 800℃,
There are carbon blacks with increased specific surface areas. Although it is possible to uniformly suspend carbon black in water using a device such as an elbow mixer that repeatedly collides and mixes in a line, it may become impossible to suspend carbon black when the viscosity becomes high. Preferably, a continuous or batch type stirrer with rotary blades is preferred, and in particular, a pipeline mixer, a lab homo mixer, and a homomix line flow (all trade names of Tokushu Kika Kogyo Co., Ltd.) can be suitably used. If the viscosity of the suspension consisting of carbon black and water obtained in the above step is low, the ability to process carbon black per unit time is low, and if it is high, sieving in the next step is impossible. Therefore, the viscosity of the suspension is preferably 1 to 100 poise, more preferably 5 to 50 poise. The vibrating sieve used in the second step of the present invention has a vibration width of 1 to 7 mm, preferably 2 to 5 mm, and a vibration frequency of 1500.
A device with ~3500 times/sec, preferably 2500-3000 times/sec is required. In particular, it is preferable to partially improve Air Fines (trade name of Fuji Powder Co., Ltd.) or use the device as is, depending on the viscosity. The amplitude of vibration is important in order to successfully transfer the carbon black suspension to the sieve mesh. For example, in the case of air fines, it can be changed by changing the position of the balance weights on the left and right sides of the sieve device, or by changing the material or type of cushion rubber. The frequency is important for smooth passage of the carbon black through the sieve mesh without clogging or sticking. For example, in the case of air electronics, the frequency can be changed by changing the size of the pulleys on the timing belt. The sieve mesh that can be attached to the vibrating sieve is 44μ or less. Preferably, 28μ and more preferably 12μ can be suitably used. In the third step of the present invention, in which carbon black is recovered from the suspension under the sieve, an organic solvent is added to the suspension to form two phases, an organic solvent phase and an aqueous phase. When this is stirred, the carbon black initially exists mainly in the water phase, but as the stirring is continued, the carbon black in the water phase moves to the organic solvent phase. At this time, if an optimum amount of organic solvent is added, the carbon black can be obtained in the form of particles, which is advantageous because the carbon black can be easily handled. If the amount of solvent added is too large or too small, it will be difficult to granulate carbon black, so the DBP absorption amount of carbon black present in the suspension (capacity of dibutyl phthalate adsorbed on carbon black) 0.8 to 2.0 times the capacity is preferable. As the organic solvent that can be used, any water-insoluble organic solvent can be used. Examples include toluene, xylene, benzene, chloroform, hexane, heptane, etc. By using the method for producing carbon black from which fine grit has been removed according to the present invention obtained in this way, when carbon black is kneaded and molded into resin or rubber using an extruder, its value as a product with improved productivity can be improved. be able to. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. Examples 1 to 8 Water absorption amount 680ml/100g CB, DBP absorption amount 340
ml/100g-CB carbon black with the characteristics of CB is added to water and stirred vigorously using a suspended TK homomixer (Tokushu Kika Kogyo Co., Ltd.) to form a uniform suspension containing 1-2% by weight of carbon black. I made it. After checking the viscosity, transfer to a vibrating sieve with a sieve diameter of 50cmφ. Next, a predetermined amount of toluene was added to the suspension that had passed through the sieve and stirred to transfer the carbon black to the toluene phase and granulate it at the same time. The obtained granular carbon black was separated from water by sieving and heated to 90 to 400°C to remove toluene and remaining water. One of the carbon blacks obtained in this way
One part was measured for the sieve residue, and the other part was kneaded into polyethylene (Novatec M-420: trademark of Mitsubishi Chemical Industries, Ltd.). Carbon black and polyethylene were kneaded using a Banbury mixer (1.7 volume, rotor rotation speed) so that the carbon black content was 10% by weight.
150 rpm, casing temperature 110°C to 120°C). After kneading, the mixture was formed into a sheet with a thickness of about 2 mm using a 6-inch oven roll heated to 90 to 100°C, and then formed into pellets of 2 to 5 mm square using a sheet cutter. Next, this pellet is made into a width of 50mm using a 20mmφ extruder.
It was extruded into a flat plate with a thickness of 2 mm. The number of convex grains present in the area of the resulting flat plate with a width of 50 mm and a length of 100 mm was observed with the naked eye. Table 1 shows the viscosity of the suspension, sieving conditions, processing capacity, sieving residue, and the number of particles formed on the surface of the suspension mixed with the resin and extruded into a flat plate. The results are shown in Table 1. Comparative Example 1 The same carbon black as that used in Examples 1 to 8 was used to measure the sieve residue and number of grains without being subjected to grit removal treatment. The results are shown in Table 1. Example 9 Water absorption 190ml/100g - CB, DBP absorption 55
ml/100g-CB carbon black was treated in the same manner as in Example 1. The results are shown in Table 1. Comparative Example 2 The same carbon black as that used in Example 9 was used to measure the sieve residue and the number of grains without undergoing any grit removal treatment. The results are shown in Table 1. In addition, the water absorption amount of carbon black is 200mm x
Put 5g of dry carbon black in a 300mm polyethylene bag, inflate it to a volume of about 1.0cm, add water from the mouth of the bag from time to time, close the bag, hold it with both hands, and shake it vigorously up and down to make one carbon black. The end point is the point where it becomes a lump, and it is calculated using the following formula. Aw=Vw/Ww×100 Aw: Water absorption amount (ml/100g-CB) Vw: Added water amount (ml) Ww: Carbon black weight (g) DBP absorption amount is based on JISK6221-1970 oil absorption method A method (mechanical method) . The oil absorption method A is a method of measuring the oil absorption of carbon black using an absorptometer. Put a certain amount of dry sample (oil absorption amount is 200ml/100g - when rubbing CB, the sample was changed from 20g to 10g) into the mixing chamber of the absorptometer, and when you turn the start switch to "ON", the inside of the mixing chamber will flow. As the rotor rotates, DBP is dripped from the bottle set at the top. When the torque reaches the set point, the limit switch is activated and the DBP stops dripping. DBP absorption amount is calculated using the following formula. A _DBP = Vo/Wo x 100 A _DBP : DBP absorption amount (ml/100g-CB) Vo: DBP dripping amount (ml) Wo: Carbon black weight (g) The sieve residue is determined using the carbon black test method for rubber.
Measured based on JISK-6221-1970 sieve residue A method. Method A involves placing a small amount of carbon black in a sieve, pouring running water through the sieve from a nozzle, washing off the carbon black until the water that passes through the sieve becomes clear, and drying the residue on the sieve at a temperature of 105 to 110℃ for 1 hour. After cooling to room temperature in a desiccator, weigh it, and calculate the residue on the sieve using the following formula. Residue on sieve = W _R / W _S × 100 (%) W _R : Residue on sieve (g) W _S : Weight of carbon black (g) In the present invention, the amount of carbon black is 500 g.
~1000g was used and the sieve residue was measured.

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[Claims]

1. An aqueous ink composition for inkjet recording, characterized in that it contains a dye having a sulfonic acid, carboxylic acid, or phenol group as a molecular structure, and an ammonium ion having the following general formula as a counter ion. [In the formula, R ₁ , R ₂ , R ₃ , and R ₄ are an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, or an alkyl group having 1 to 4 carbon atoms partially substituted with a halogen, and R ₁ , R ₂ ,
At least one of R ₃ and R ₄ is the above substituted alkyl group. ]