JPS61244A - Granulation method - Google Patents

Abstract

PURPOSE:To obtain a glossy granular product which has excellent flowability and undergoes little disintegration, by tumbling crude N-1,3-dimethylbutyl-N'- phenyl-p-phenylenediamine while keeping it under specified different temperature conditions. CONSTITUTION:Crude N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine which may possible contain not more than 20wt% powders of the particle size of passing through a 0.5mm. sieve and has a melting point of 45-50 deg.C is put in a granulator of, e.g., drum type, and is tumbled while keeping at 38-44 deg.C for 2-120min and then at 30-37 deg.C for 5-90min to obtain a granular product of the aforementioned compound which is substantially free of dusting, caking, etc. and has a smooth surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for granulating N-1,8-dimethylbutyl-N'-phenyl-p-phenylenediamine (hereinafter abbreviated as 6-PPD).

6-PPD has a melting point of 45 to 50°C and is solid at room temperature, so it is commercially available in flake, rod, hemispherical, and spherical product forms, and is widely used as an anti-aging agent for rubber and other products. However, each of these has problems in production or use, and improvements are desired. For example, hemispherical products can be obtained by dropping 6-P PD melt onto a belt flaker and solidifying it, but manufacturing requires special machinery and a large amount of equipment costs to increase production capacity. There is the above problem, and the spherical product' is 6-P P
It is obtained by adding a molten liquid to water and cooling it to solidify it, but this method has production problems in that the adhering water must be removed by drying and a large amount of energy is required. , :.

On the other hand, flake products and grated products are easily produced using a flaker-1 extrusion granulator, etc., but both of these products are easily disintegrated and become powder during transportation, causing the powder to scatter during use, resulting in In addition to the problem of significantly deteriorating the environment, 6-PPD has a low melting point as described above, so if the small amount of powder produced is solidified into a lump, there is a big problem in use that is unique to 05゛6-PPI). For this reason, considerations have been made such as filling the container in a strong container to prevent collapse and caking, storing it in a low-temperature warehouse in the summer, or reducing the amount of filling in the hopper, which essentially prevents fluidity. There was a desire for an improvement to a granular product that has excellent properties, has less disintegrability, and is less likely to generate dust or caking.

For this reason, the present inventors have developed a granular product 6 that has excellent fluidity, has low disintegrability, and is resistant to dust and caking.
- As a result of intensive research into a method for obtaining PPD at low cost and easily, the present invention has been completed.
Crude product N-1, which may contain up to t%
The N-
This invention provides a method for granulating 1,8-dimethylbutyl-N'-phenyl-p-phenylenediamine.
be.

According to the present invention, a granular product 6-PPD with excellent fluidity, low disintegration (hard to generate dust, caking, etc.), and a smooth and glossy surface can be obtained easily and inexpensively.

The crude 5-PPD used in the present invention is usually in a shape that facilitates the production of powder, such as flakes, rods, or irregular shapes, but it may also be hemispherical, spherical, or A mixture of these may be used. Its particle size is usually between 0.5 and 5.7 Bg, preferably 1
．． It is between 0 and 4.8 mm sieve, but 0.5 w+
Powder under the sieve may be present at the same time, and its amount is 2Q
It is not more than wt%, more preferably not more than 15wt%.

In the present invention, 6-P PD is transferred in two stages under specific different humidity below the melting point, and the temperature in the first stage is in the range of 38 to 44°C, preferably 88 to 42°C. The transfer time is usually 2 to 120 minutes, preferably 5 minutes.
-90 minutes, the temperature of the second stage is 30-37℃, preferably 83-37℃, and the transfer time is usually 5-90℃.
If the transfer is carried out only under the temperature of the first stage, preferably 10 to 75 minutes, the corners that cause powder formation will disappear, but the surface will remain in a rough state with some of the powder fused. If the rolling is carried out only at the temperature of the second stage, the corners will hardly be removed, and rolling is performed in the reverse order of the present invention, i.e., first at the temperature of the second stage, then at the temperature of the first stage. Although the corners disappear when the powder is moved, some of the powder remains fused on the surface, and either method produces the desired granular shape that has excellent fluidity, is less likely to disintegrate, and is less likely to cause dust or caking. I can't get the product.

However, according to the two-stage transfer method specified in the present invention, the corners first disappear due to the first heat-retaining transfer and the powder is partially fused to the surface, and then some of this is removed by the second heat-retaining transfer. The fused powder is completely fused to the surface, making the surface smooth and glossy. As a result of the surface being in such a state, the obtained 6-PPD has excellent not only fluidity but also collapse resistance, and is resistant to dust, solidification, etc.

Examples of the transfer granulator used in the present invention include a drum-type granulator, a dish-type granulator, and an agitating/rolling granulator. In actual granulation, for example, a dedicated granulator may be used for the first stage and second stage thermal rolling, or the first stage and second stage are located near the inlet and outlet, respectively. A granulator set at a temperature suitable for the eyes may also be used. Furthermore, granulation can also be carried out by using a variable temperature granulator and changing the temperature in two stages.

The present invention will be explained in detail below with reference to Examples.

Reference example-1 Using 6-PPD with a melting point of 47-50°C, the product temperature was 44-46°C.
After bringing the mixture to a semi-molten state at ℃, it was extruded using a screw type extrusion granulator. This was cooled to room temperature, sized using a crusher and sized, and then classified. Among the obtained ones, diameter 4m, 8
．． Rod-shaped products with a particle size between 4 and 4.81 sieves and between 1,0 and 8.
The weight ratio between 4 vm fIB and irregularly shaped particles is 7.
0:30, and the surface was rough with corners and powder adhering to it.

Example 1 The mouthpiece obtained in Reference Example 1 was placed in a 500 ml stainless steel container equipped with a thermometer and a stirring blade.

84 g of the rod-shaped product and 6f of the irregularly shaped product were put therein, and the mixture was rolled at a temperature of 42°C for 30 minutes to cool to room temperature. Then temperature 84
After tumbling for 90 minutes at <RTIgt;C,</RTI> the mixture was taken out from the container and cooled to room temperature to obtain 116 g of 6-PPD granules having a particle size between 1.0 and 4.8. The surface condition of this product was smooth and glossy, and the shape was close to spherical.

Next, we put 60 f of this into a polyethylene bag (120 x 85 mm), applied a load of 40 kg, left it in a constant temperature bath at 87°C for 5 days, and conducted a deposition test. Then, the contents were taken out from the bag and solidified into 17 clumps. Determine the weight percent of the bound 6-P PD,
This was taken as the consolidation rate.

The results are shown in Table 1.

(Comparative Example 1 After mixing the rod-shaped product 84F obtained in Reference Example 1 and the irregular-shaped product 86f, a deposition test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 Rolling granulation was carried out in the same manner as in Example 1 except that heat-retaining rolling was carried out at a temperature of 42°C for 30 minutes in Example 1, and the particle size was 1.0 to 4.8.
Obtained 118 g of granules between m and fH. Although the corners had been removed, the surface was rough and some of the powder was fused. Next, using this, a deposition test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

Table 1 Deposition test results reference example 2 6-P PD with a melting point of 46'C to 49'C and a product temperature of 4B to
The mixture was brought to a semi-molten state at 45°C and cut into lengths of 30 to 85 mm using a knife while being extruded using a roll extruder.

Next, this was cooled to room temperature, sized using a crusher and sized, and then classified. Among the obtained ones, diameter 8III+, particle size 2
．． 8-8.4 tII+1 mouth/sod-like products and particle size 0.5
The weight ratio of irregular shaped products between ~2.8mm sieve is 85:15
All of them had rough surfaces with corners and powder adhering to them. 41 Example 2 Rod-shaped product 91.8F irregular-shaped product obtained in Reference Example 2 16.
2F and 12g of 0.5 mm sieve or smaller were placed in a rotary dryer and tumbled at a temperature of 40"ct for 60 minutes.
It was cooled to 35° C. over 0 minutes, rolled at that temperature for 30 minutes, taken out, and cooled to room temperature. A 6-PPD granular product 115f having a particle size between 0.5 and 8.4 parts was obtained.

The surface was smooth and glossy.Next, this product was subjected to a deposition test in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example-8 Mouth/sock-shaped product 102f and irregular-shaped product 1 obtained in Reference Example-2
8F was mixed and a deposition test was conducted in the same manner as in Example 1.

The results are shown in Table 2.

Comparative Example-4 Rolling granulation was carried out in the same manner as in Example-2, except that heat-retaining rolling was performed at a temperature of 40° C. for 60 minutes, and the particle size was 0.
A granular product 117f having a sieve width of 5 to 8.4 m was obtained. Although the edges were rounded, the surface was rough and some of the powder was fused.

This product was subjected to a deposition test in the same manner as in Example-1. The results are shown in Table-2.

Table-2 Deposition test results

[Brief explanation of the drawing]

The drawings are micrographs (1.7 times magnification) of each step of granulation of Japanese 6-PPD according to the method of the present invention. The forms after the two-stage rolling process are shown.

Claims (1)

[Claims] Crude N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine, which may contain powder of 0.5 mm sieve or less in the range of 20 wt% or less, is
N-1,3-dimethylbutyl- characterized by being heated and rolled under different temperature conditions of 4°C and then 30 to 37°C.
Method for granulating N'-phenyl-p-phenylenediamine