JP2956122B2 - Wet granulation of carbon black - Google Patents

Description

The present invention relates to a wet granulation method of carbon black.

(Prior art) Powder granulation methods are roughly classified into a wet method in which water or other liquids are used for granulation and a dry method in which no medium is used. Has been adopted.

This wet granulation is carried out by agitating and rolling an aqueous solution containing water or a binder and a powder in a granulator.

However, carbon black, which is easily powdered, has fine powder particles that adhere to the walls of product storage tanks, chutes, conveyors, measuring buckets, hoppers, etc., impeding the flow of carbon black, disrupting the process, In such a case, the work efficiency may be reduced, and contamination due to scattering may occur.

As a method of granulating carbon black that is difficult to pulverize, a method of increasing pellet hardness is well known.However, if the pellet hardness is increased, the dispersion of carbon black in polymers such as rubber becomes worse, and the conventional pelletizing method is used. Then, it cannot be said that the relationship between powdering and dispersion is sufficiently satisfied.

For example, Japanese Patent Publication No. 45-24644 discloses that by narrowing the size distribution of pellets, it is possible to obtain a granular material which is rich in fluidity and is not easily broken. Although it is recognized, a sufficient effect is not necessarily recognized on the breakage of the pellet itself.

(Means for Solving the Problems) Accordingly, the present inventors have conducted intensive studies in order to obtain a carbon black granulation method that maintains a good dispersion level, that is, an appropriate pellet hardness, and is hard to be powdered. The present invention has been achieved by applying a specific nonionic surfactant in addition to the above binder.

That is, in the present invention, when producing carbon black pellets by a wet granulator, 0.1% (% by weight) or more of ether type polyoxyethylene type nonionic surfactant based on carbon black is used as a lignoate. And granulation by adding it together with water and water to produce carbon black pellets that are hardly powdered.

First, as the polyoxyethylene type nonionic surfactant used in the present invention, an ether type is used, and the number of moles of oxyethylene is preferably 10 or more. For example, Kao Corporation "Emulgen A-6
0 "is preferably used.

These surfactants are used in 0.1
% By weight, usually 3% by weight or less.
When the amount is less than the weight%, the effect of preventing powdering is small, which is not preferable.

Ligninate is used as a binder used together with these surfactants.

The amount of the binder is usually 0.5% by weight or more based on the carbon black in order to maintain the hardness of the carbon black pellet at an appropriate level. In the present invention, the above surfactants and binders are usually used in granulation by dissolving or dispersing in 50 to 150% by weight of water with respect to carbon black. Granulation itself can be performed by a conventional method.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Examples 1 to 4 and Comparative Examples 1 to 6 10 kg of FEF-grade furnace black was introduced into a rotary pin type granulator, and 400 l of an aqueous solution in which a predetermined amount of a nonionic surfactant and a binder component were dissolved was added at 400 rpm. Granulation was performed at a rotating speed to obtain pellets (beads) having a diameter of 0.1 to 2.0 mm.

Subsequently, it was transferred to a stationary dryer and dried at a temperature of 140 ° C.

Using the granulated carbon black prepared as described above as a sample, a powdering test was performed as follows.

(Pulverization test) Using Red Devil's “Paint Conditioner” (shaker), put 20 g of sample in mayonnaise bottle (150 ml), shake for 5 minutes x 6 times for a total of 30 minutes, and powder carbon black of 100 mesh or less. Was measured.

Table 1 shows the powdering test results and the bomb test results.

For comparison, the other conditions were the same as in the example, and an example in which no surfactant was added and an example in which the surfactant was replaced were performed.

 The results are shown in Table 1 (Comparative Examples 1 to 6).

As is clear from the above results, the granulated carbon black of the present invention has greatly improved powderability without increasing the hardness.

(Effect of the Invention) According to the present invention, it is possible to obtain a pellet-shaped carbon black which has excellent handling characteristics and is hardly powdered.

Therefore, in transportation, storage and other handling, prevention of sticking of equipment and the like, and contamination due to scattering are greatly reduced.

Continuation of the front page (56) References JP-A-2-166169 (JP, A) JP-A-55-118970 (JP, A) US Patent 3,565,658 (US, A) US Patent 3,844,809 (US, A) US Patent 3,645,765 (US, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C09C 1/58

Claims (1)

(57) [Claims] 1. A method for producing carbon black pellets, comprising adding at least 0.1% (% by weight) of ether type polyoxyethylene type nonionic surfactant to carbon black together with lignate and water to form granules. Wet granulation of carbon black.