JPS60248649A - Granulation of n-alkyl-n'-phenyl-p-phenylenediamine - Google Patents

Abstract

PURPOSE:To obtain particles of the titled compound having desired particle diameter and high fluidity, by using a granulator composed of a double-cylindrical vessel wherein the thickness and perforation diameter of the outer cylinder of the double cylinder are set within specific ranges. CONSTITUTION:The objective double-cylindrical vessel is composed of the inner cylinder 8 capable of holding molten liquid of N-alkyl-N'-phenyl-p-phenylenediamine and having opening 3 at the circumferential wall and the outer cylinder contacting with the outer circumferential surface of the inner cylinder, rotating relative to the inner cylinder and having plural perforations 5 at the circumferential wall. The opening of the inner cylinder is connected periodically to the perforations of the outer cylinder according to the rotation of the cylinder. The wall thickness (b) and the perforation diameter (a) of the outer cylinder are selected to satisfy the relationship of the formula. The molten liquid of the amine is dripped to the cooling material 7 maintained at a temperature lower than the melting point (80 deg.C), and is cooled and solidified on the steel belt of the cooling material to obtain the granules 10 of the objective compound. The amine granule has spherical - hemispherical form and extremely excellent fluidity, and can be utilized in wide range in the rubber processing field.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for granulating 9N-alkyl-N'-phenyl-P-phenylenediamine, which is highly productive and can efficiently obtain particles of a desired particle size with good fluidity. It depends.

"Prior art J N-alkyl-N'-phenyl-P-7 enylenediamine having an alkyl group with a small number of carbon atoms in the molecule,
Generally, they have a low melting point, and even if the molten liquid is supercooled below the melting point, it does not crystallize easily, and it takes a long time to cool and solidify it. For example, conventionally, N-alkyl-NZ -
A molten solution of enyl-P-phenylenediamine was passed through an excessively cooled endless belt, and those that did not crystallize easily were cooled and solidified into flakes over a long period of time.

According to this method, an extremely long endless belt, that is, a belt flaker, is required, and there is a problem in terms of location. The flakes vary in shape, ranging from large ones to powdered ones, making it difficult to measure them before use, and causing environmental pollution due to dust, which may even harm the health of workers.

Various granulation methods are conventionally known as methods for granulating N-alkyl-N'-phenyl-P-phenylenediamine. For example, in Japanese Patent Publication No. Sho Ill'-3,210, there is an invention in which a melt of an amine-based organic compound is dropped into an aqueous solution containing a hydrophilic polymer compound; discloses an invention in which an organic rubber chemical is dispersed in an aqueous solution containing an organic solvent and granulated by heating it to a temperature below the boiling point of water. Add the melted amine inhibitor to the aqueous solution, stir,
Inventions that solidify by cooling are described respectively. All of these inventions involve a wet method of granulating water as a metal medium, require a drying step or a solvent recovery step after granulation, and do not necessarily obtain particles of a constant size and shape. It is not necessarily an excellent method from an industrial perspective as it is not suitable for the purpose and requires a sieving operation.Furthermore, hydrophilic polymers, surfactants, etc. attached to the particles reduce the performance as an organic rubber chemical. There was a problem. Also,
JP-A-J/-//773 describes a method for producing hemispherical particles by dropping a melt of a rubber anti-aging agent onto a completely cooled steel belt and solidifying it. It was difficult to adjust the amount of dropping, high-speed production was impossible, and the productivity was not fully satisfactory.

[Problems to be Solved by the Invention] The present inventor 1d has found that particles of N-alkyl-N'-phenyl-P-phenylenediamine are industrially advantageous and have good fluidity and have a desired particle size. As a result of intensive study on an efficient and easy method to obtain the product, we decided to use a double cylindrical container type granulation device.
By setting the wall thickness of the outer cylinder of the cylindrical container and the perforation diameter within a specific range, it is possible to produce particles of a constant size and shape at high speed, and the obtained N-alkyl-N' -Phenyl-P-phenylenediamine particles) It was discovered that the particles also have excellent fluidity, and the present invention was completed. And, the method of the present invention provides N-alkyl-N'-phenyl-P-
It has been found that it is very effective to precipitate crystals by stirring a melt of phenylenediamine in a supercooled state, and then dripping the melt into a coolant maintained at a temperature below the melting point while the melt is in a slurry state. I found it.

"Structure of the Invention" However, the gist of the present invention is that the material is solid at room temperature and has a melting point of t.
A method of granulating particles of N-alkyl-N'-phenyl-P-phenylenediamine by dropping a melt of N-alkyl-N'-phenyl-P-phenylenediamine below the OC onto a coolant maintained at a temperature below the melting point of the amine, an inner cylinder having an opening in the peripheral wall and capable of storing the N-alkyl-N'-phenyl-P-phenylenediamine melt, and rotating relative to the inner cylinder in contact with the outer peripheral wall of the cylinder; A double cylindrical container consisting of an outer cylinder with a plurality of perforations in the peripheral wall, and the perforations and openings periodically overlap with each other as it rotates, and a space between the wall thickness of the outer cylinder and the perforation diameter a. A method for granulating N-furkyl-N'-phenyl-P-phenylenediamine is characterized by using a product having the following relationship 2 of the formula %.

To explain the present invention in detail, N-furkyl-N'-phenyl-P-phenylenediamine used in the present invention is:
Its melting point must be below roC, and it is solid at room temperature. If the melting point is higher than rθC, it is easily solidified by the usual method, ie, by flowing or dripping the melt onto a cooled coolant, which takes a longer time. but,
If the melting point is below rOC, large particles exceeding 10 trmf will not solidify easily even if they are dropped or dropped into the coolant, but will solidify into a uniform size and shape because the molten liquid flows and spreads. It was difficult to do so, and it was common for the crystallization to take a long time in the form of flakes. N whose melting point is below OC
-Alkyl-N'-phenyl-P-phenylenecyamine usually has many carbon atoms in its alkyl group, including branched chains, of 3 to t. For example, N-secondary hebutyl- such as N-(/,F-dimethylpentyl)-Nl-phenyl-P-phenylenediamine, N-(/-methylhexyl)NJ-phenyl-P-phenylenediamine, etc.
N'-phenyl-P-phenylenediamine, N-(/,
j-dimethylbutyl) -NJ-phenyl-P-7 22-diamine, N-(/-methylpentyl)-N'-phenyl-P-phenylenediamine, etc.
Examples include N'-phenyl-P-phenylenediamine, N-ingurobyl-N'-phenyl-P-phenylenediamine, and the like. Of course, the alkyl group may be a primary alkyl group. Moreover, these may be used in combination. However, it is better not to mix materials with relatively low melting points.

The process of the invention is particularly suitable for N-(/,+-dimethylpentyl)-N'-phenyl-P-phenylenediamine, N-(
/, 3-dimethylbutyl)-N'-phenylene/l/ -P
Suitable for granulation of -phenylenediamine and N-isopropyl-N'-phenyl-P-phenylenediamine,
/, J-dimethylbutyl)-N'-phenyl-P-phenylenediamine. By the way, N
-(/, Hiro-dimethylpentyl) NJ-phenyl-P
- Melted Al of phenylene diamine, 3λ~3 da U, N-(
The melting point of N-impropyl-N'-phenyl-P-phenylenediamine is ≠μ~≠0%. 7G, and the other compounds mentioned above also exhibit melting points that are approximately the same as those of structurally similar compounds.

The granulation device used in the method of the present invention includes all double cylindrical containers,
The inner tube of the double cylindrical container has an opening penetrating its peripheral wall, and inside the tube is N-alkyl-N'-phenyl-P-.
The phenylenediamine melt can be stored, and a heat retaining device or a heating device is provided to prevent the melt from solidifying within the inner cylinder. The structure is such that the melt can be continuously supplied from outside the cylindrical container through piping, and the inner cylinder is usually fixed without rotating. The openings provided in the inner cylinder may be a plurality of perforations usually provided on a line parallel to the axis of the cylinder, or may be elongated slits. The opening is preferably located at the lowest position of the fixed inner cylinder. By doing so, complete discharge of the melt can be achieved.

Further, the outer cylinder of the double cylindrical container is configured to contact the outer peripheral wall of the inner cylinder and rotate relative to the inner cylinder, and the peripheral wall of the outer cylinder is provided with a large number of regular round perforations, The structure is such that the opening of the inner cylinder and the perforation of the outer cylinder periodically overlap with each other as the cylinder rotates. The outer cylinder must be constructed such that the relationship between the wall thickness and the perforation diameter a is expressed by the general formula (1). Further, it is preferable that the distance between the respective perforations is at least three times the diameter of the perforations between the centers of the perforations. If the value of b/a is smaller than o, t, or o, a large amount of the molten N-alkyl-N'-phenyl-P-phenylenediamine flows out of the double cylindrical container, does not solidify easily, and particles Also, the particle size and shape of the N-alkyl-N'-phenyl-P-phenylenediamine become inconsistent due to the coalescence of the particles, making it difficult to obtain particles 2 of a desired size. On the other hand, the value of b/a is /, coj
If the diameter is too large, the N-alkyl-N'-phenyl-P-phenylenediamine solidifies inside the borehole and tends to completely block the borehole, and even if the borehole is not clogged, it is difficult to drain the molten liquid from the outer cylinder. However, it is not possible to obtain particles with a constant thick particle size.

Furthermore, if the hole diameter a=jH is made smaller for the wall thickness,
That is, when the value of b/a is larger than /, coj, it is necessary to reduce the rotational speed of K in order to obtain a good particle shape, resulting in a significant decrease in productivity. therefore,
It is an essential requirement of the present invention to use a double cylindrical container having the relationship expressed by general formula (1) between the outer cylinder wall thickness and the perforation diameter a. Therefore, the value of b is preferably 31m111 or less, particularly 2wM or less, in order to make the N-alkyl-N'-phenyl-P-phenylenediamine particles as close to spherical as possible. By appropriately employing outer cylinders with different wall thicknesses, it is possible to obtain particles with a desired particle size.

A drawing of the apparatus used in the method of the present invention? This will be explained in further detail using

FIG. 1 is a perspective view of an example of a granulation device used in the method of the present invention, FIG. 2 is a partially enlarged vertical cross-sectional view of the granulation device shown in FIG. 1, and FIG. FIG. 3 is an enlarged vertical cross-sectional view of a perforated portion of the granulation device. In the figure, l\'i double cylindrical container, λ is the inner cylinder, 3 is the opening, ≠ is the outer cylinder, j is the perforation, 6 and 6' are gears for rotating the outer cylinder, 7 is an endless steel belt, and t is the N-alkyl-N'-phenyl-P-phenylenediamine melt supply pipe, 2' is a heating or cooling mechanism for the melt, 10 is N-alkyl-N'-phenyl-P-phenylenediamine particles, // is the stand, a is the hole diameter, b is the outer cylinder wall thickness,
A indicates the particle diameter, and arrows indicate all directions of rotation or movement.

In the granulation device shown in FIG. 2, an endless steel belt 7 cooled to a temperature below the melting point of N-furkyl-N'-phenyl-P-phenylenecyamine is placed under a double cylindrical container l, and It moves in the direction of the arrow in conjunction with Tsutsuhiro's rotation. The inner cylinder λ of the double cylindrical container l is unrotatably fixed to the stand //, and the inner cylinder contains molten N-furkyl-N'-phenyl-P-phenylene diamine. The molten liquid is provided with a supply pipe that opens within the inner cylinder that supplies the liquid, and a heating mechanism 2' that is disposed within the inner cylinder and prevents solidification of the molten liquid. The heating mechanism 2' can be used as a cooling mechanism. Inner cylinder λ
A slit-shaped opening 3 penetrating the inner cylinder wall is cut on the side facing the steel belt 7, and the molten liquid is discharged from this opening 3. The outer cylinder has a thick wall and is arranged to rotate in contact with at least the opening 3 in the outer peripheral wall of the inner cylinder, and is engaged with a gear provided at the end of the outer cylinder. It is rotated by an external force such as an electric motor through a gear 6'. The outer cylinder has a plurality of regularly arranged perforations passing through its peripheral wall and having a diameter at-! As the outer cylinder ≠ rotates, molten N-alkyl-N'-phenyl-P-phenylenecyamine is dripped into the hole that periodically overlaps with the opening 3 of the perforated inner cylinder 2, and the steel belt is 7 and granulated into 10t of N-alkyl-N'-phenyl-P-phenylenediamine particles.

N-alkyl-N'-7Eni-P constituting the granulation device
- Droplets of phenylenediamine The coolant that cools is not limited to the steel belt 7 described above,
For example, using a water tank filled with cooling water, N from a double cylindrical container is
-Alkyl-N'-phenyl-P-phenylenediamine dissolved in water may be used.

In this case, a process to separate particles and water sound is required.
Preferably, the steel belt method described above is employed.

In the case of (l,3-dimethylbutyl)-N'-phenyl-P-phenylenediamine, the following particle size can be obtained in relation to the wall thickness of the outer cylinder and the perforation diameter a.

Wall thickness b (w++) Hole diameter a (mφ) Particle diameter (reduction φ)
J J 7 ~ t , 2 2 ≠ ~ j l, j /+j 3 ~ Jj l / +2 ~ co, j O6tO6Jr/, jS-λ To carry out the method of the present invention, N-alkyl-N'-phenyl- A molten solution of P-phenylenediamine is continuously dripped from the perforations of the double cylindrical container type granulator while rotating the outer cylinder. As the melt of N-alkyl-N'-phenyl-P-phenylenediamine, N-alkyl-N'-
The melt during the production of phenyl-P-phenylenediamine,
or flaky or powdered N-alkyl-N'-
A melt obtained by raising the temperature of phenyl-P-phenylenediamine to a temperature higher than its melting point may be used as it is, or as described later, it may be supercooled to precipitate microcrystals before use. N-alkyl-N'-phenyl-P-phenylene diamines have different melting points depending on the type, and melt viscosity also differs depending on the temperature of the melt. It is necessary to select an appropriate temperature or melt viscosity depending on the type of y. This can be determined by some preliminary experiments. In general, materials with a low melting point are supplied to a double cylindrical container at the lowest possible temperature and dripped. Preferably, the molten liquid is easily solidified when dropped into the coolant, probably because it is subjected to shear force between the outer cylinder and the inner cylinder.In the method of the present invention, assimilation after dropping is quickly performed. , and also reduce the particle size (
In order to approximate a spherical shape, the melt is preferably supplied to the inner cylinder of the double cylindrical container in a supercooled state. for example,
The melt is cooled by a refrigerant outside the threads of the granulator to lower its melting point to j-! Bring the OC into a supercooled state with a low temperature. Stirring in a supercooled state (applying shearing force) may be carried out while stirring or in a supercooled state. For example, if you create a supercooled state while continuing to stir,
Depending on the type of N-alkyl-N'-phenyl-P-phenylenediamine, fine crystals gradually or quickly precipitate to form a slurry.

The supercooling temperature is N-alkyl-N'-phenyl-p-
The method is determined as appropriate depending on the type of phenylenediamine. If the supercooled state is maintained for a long period of time, the entire melt will solidify, so once a suitable amount of crystals have precipitated, it is desirable to heat it again at a temperature above the melting point while stirring.

The temperature above the melting point is sufficient if the temperature of the heating medium is above the melting point, and it is preferable that the temperature is not extremely high. For example, it is preferably higher than the melting point and within JOC, preferably within 700, particularly within 10, and in long-term operation, the temperature of the melt itself often reaches this temperature. Even if the temperature of the melt itself exceeds the melting point, the precipitated crystals will
It does not melt easily and remains in a slurry state.

The method of the present invention allows this more N-alkyl-N'-7z
The precipitated molten liquid of Nyl-P-phenylenediamine is fed into a double cylindrical container in a slurry state, and then cooled and maintained at a low temperature below the melting point on a coolant, for example, an endless belt. , or preferably dropped into water. The temperature of the coolant should be as low as possible, i.e. N-furkyl-N'-phenyl-
The larger the difference between the melting point of P-phenylenediamine and the temperature of the coolant, the better. It is desirable that the content of fine crystals in the slurry to be dropped is high, but if it is too high, there is a risk of clogging the perforation of the outer cylinder of the double cylindrical container, so the content is lower than rO weight %, preferably ≠Q ~ 70 weight %. It is appropriate to drop a slurry with a crystal concentration within a certain range.

The slurry dropped onto the coolant solidifies immediately or rapidly, and has a circular cross-sectional shape.

In the granulation method of the present invention, N-alkyl-N'-
Additives such as paraffin, stearic acid, zinc white, etc. may be added as appropriate while the phenyl-P-phenylenediamine is in the melt or slurry state.

Adding paraffin involves mixing paraffin in a heated fluidized state while N-alkyl-N'-phenyl-P-phenylenediamine is in a melt or slurry state, and uniformly mixing the melt or slurry and paraffin. N containing paraffin is added dropwise to the liquid coolant.
-Alkyl-N'-phenyl-P-phenylenediamine is granulated very easily. Contains paraffin
For dropping the melt or slurry of -alkyl-N'-phenyl-P-phenylenediamine, the dropping conditions can be selected as appropriate depending on the physical properties and content of paraffin.
It can be found out by a simple test. Also,
The temperature of the coolant and the crystal content in the slurry may also be determined by similar tests.

[Effect of the invention J] According to the method of the present invention, by using a granulating device including a double cylindrical container in which there is a specific relationship t between the wall thickness of the outer cylinder and the perforation diameter, uniform size can be achieved. and N-alkyl-N having the form f
'-Phenyl-P-phenylenediamine particles can be produced with high efficiency, and N-alkyl-N'-phenyl- P-phenylenediamine particles can be obtained. Furthermore, the temperature of the melt that produces the desired particle size can be found by some preliminary experiments.

The N-alkyl-N'-phenyl-P-phenylenediamine particles produced in this way have a spherical to hemispherical appearance and have excellent fluidity, expanding the scope of their use in the rubber processing field. Its industrial value is extremely high.

However, according to the method of the present invention, even if the fine crystals are precipitated in the N-alkyl-N'-phenyl-P-phenylenediamine melt, they can be easily dropped from the perforation of the outer cylinder of the double cylindrical container. The dripped material solidifies immediately or rapidly, resulting in excellent operability and productivity.
Moreover, a product with uniform, extremely hard particles and a uniform shape can be obtained. It is. In addition, the size of the particles may be changed depending on the adoption of outer cylinders with different wall thicknesses and/or hole diameters, for example, 8 jtrrm.
~10 tFm can be obtained, and can be appropriately selected according to customer requirements. Furthermore, the sieving work during operation can be simplified, and the endless belt is short and space-saving.
The present invention is not limited to the following examples unless it exceeds the gist thereof.

Example/~tei, Comparative example/~3 N-(/,3-dimethylbutyl)-N'-phenyl-
P-phenylenediamine (melting point Hirohiro to Hirohiro C) flakes were heated to ft OC and completely melted. This was gradually cooled with a refrigerant while stirring to a temperature that was still below the melting point of the phenylenediamine. No fine crystals were observed in 4LgC, and almost 50% when cooled to 3JC.
The result was a slurry with precipitated crystals. The molten liquid of Guhiro C and the slurry-like molten liquid cooled to 3jrC are continuously supplied to the double cylindrical container type granulator shown in Fig. dripped onto a steel belt. When the outer cylinder wall thickness b5 hole diameter a and the phenylenediamine outer cylinder wall thickness and hole diameter are in the relationship of general formula (1), the shape is spherical or nearly spherical, and the size is uniform, resulting in improved productivity. The particles have excellent fluidity. On the other hand, when the value of b/a is as small as OoS, productivity is excellent.

The particles have a flat particle shape, resulting in particles with poor fluidity, and b
The value of /a is 2. If O is too large, the molten liquid will not fall regularly from the perforation, and its shape will be irregular, which will impede the quality of the raw material. In addition, when the temperature of the melt is high, the smaller the value of b/a, the more the melt drops from the perforation.
It is easier to form a flat shape compared to a pot with a low melt temperature.

When the melt temperature is low and the value of b/a is large, assimilation of the melt tends to occur during perforation, making production impossible.

Therefore, it can be seen that it is necessary to drop a molten liquid kept at an appropriate temperature so that the value of b/a falls within the range of the general formula CI).

Example j-za, Comparative example μ, j Implementation? 3j of N-(/, J-dimethylbutyl)-N'-phenyl-P-phenylenediamine used in 14/
The slurry-like melt of C was dropped in the same manner as in Example, except that the wall thickness of the outer cylinder and the perforation diameter were exceeded to obtain a granulated product. wall thickness b,
When the relationship between the hole diameter a and the wall thickness of the outer cylinder diameter becomes larger than Jllllll, the molten liquid dripped onto the steel belt solidifies in a slightly flowing shape, and is easily formed into a live spherical shape, causing particles to flow. Sexuality also deteriorates. Furthermore, if the pore diameter is small relative to the wall thickness, it becomes difficult for the molten liquid to flow, resulting in poor productivity and a tendency for particle diameters to become uneven, resulting in markedly poor fluidity.

[Brief explanation of drawings]

Fig. 7 is a perspective view of an example of a granulating device used in the method of the present invention, Fig. 2 is a partially enlarged vertical cross-sectional view of the granulating device shown in Fig. 1, and Fig. 3 is a perforated portion of the granulating device. FIG. In the figure, l is a double cylindrical container, C is an inner cylinder, 3 is an opening, 3 is an outer cylinder, j is a perforation, a is a perforation diameter, and b is an outer cylinder wall thickness. Patent applicant Mitsubishi Monsanto Chemical Co., Ltd. Agent
Patent Attorney Hase - 7 others Figure 1/θ 3 Figure

Claims (6)

[Claims] (1) By dropping a melt of N-alkyl-N'-phenyl-P-phenylenediamine, which is solid at room temperature and has a melting point below IOC, into a coolant maintained at a temperature below the melting point of the amine, In a method for completely granulating amine particles, an inner cylinder having an opening in the peripheral wall and capable of storing the entire N-alkyl-N'-phenyl-P-phenylenediamine melt, and an inner cylinder in contact with the outer peripheral wall of the cylinder are used. A two-wheeled cylindrical container consisting of an outer cylinder that rotates relative to an inner cylinder and has a plurality of perforations in its peripheral wall, and the perforations and openings become periodically shaped as the outer cylinder rotates. A method for granulating N-alkyl-N'-phenyl-P-7 ethylenediamine, characterized by using a material having the relationship between wall thickness and perforation diameter a as expressed by the following formula %. (2) The method for granulating N-alkyl-N'-phenyl-P-phenylenediamine according to claim 7, wherein the wall thickness of the outer cylinder is 3 mm or less. (3) N-alkyl-N according to claim 1, wherein the melt of N-alkyl-N'-phenyl-P-phenylenediamine contains microcrystals precipitated in a supercooled state. '-7Enyl P-phenylenediamine granulation method. (4) N-alkyl-N' according to claim 1 or 3, wherein the alkyl group of the N-alkyl-N'-phenyl-P-phenylenediamine has 3 to j carbon atoms.
- A method for granulating phenyl-P-phenylenediamine. (5) N-alkyl-N'-phenyl-P-phenylenediamine is converted to N-secondary hexyl-Ml-7enyl-F
-722 diamine fir! N-Fuchiru N to 2nd grade
A method for granulating N-alkyl-N'-phenyl-P-7-enylene diamine according to claim 1, 3 or V, which is '-phenyl-P-7-enylene diamine. (6) N-alkyl-N'-phenyl-P-7 enylenecyamine is N-isopropyl-N'-7e = # -P
-phenylenediamine S N (' + 3-dimethylbutyl) + Hz-phenylene-P-phenylenediamine N-alkyl-N according to claim V
'-Pheny/l/-P-phenylenediamine granulation method.