JPH0210181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a spherical product of an amine-based anti-aging agent, and more specifically, the present invention relates to a method for producing a spherical product of an amine-based anti-aging agent. This invention relates to a method for producing a spherical product of an antiaging agent, and its purpose is to obtain a spherical product with excellent fluidity and low disintegration.

N-isopropyl-N'-phenyl-p-phenylenediamine, N-1,3-dimethylbutyl-
N′-phenyl-p-phenylenediamine, etc.
Diphenylamine anti-aging agents for rubber, which are solid at room temperature, are commercially available as flakes and rods, but these are easily disintegrated and turn into powder during transportation, causing dust to scatter during use and causing problems during work. The problem was that it significantly degraded the environment. In addition, especially for compounds with low melting points such as N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine, the formation of a small amount of powder causes development in which it solidifies into a block shape, so the product It is necessary to remove fine powder by sieving, which causes a significant decrease in yield, and it is also necessary to improve the melting point of the product surface or to pack it in a rigid container to prevent it from collapsing during transportation. There were problems such as the occurrence of

Further, in recent years, automatic metering has progressed in tire manufacturing and other compounding processes in the rubber industry, and with this, it has become necessary to continuously and meterly supply anti-aging agents in fixed amounts. Furthermore, improvements have also been made in which several types of compounding agents are pre-mixed uniformly in advance. However, conventional product forms such as flakes and rods have poor fluidity, making it difficult to meter and supply them in fixed amounts, and also having poor mixing properties during pre-compounding treatment.

Possible methods for making the anti-aging agent into spheres include pelletizing it and then making it into spheres using a marmerizer, dropping it onto a belt flaker and solidifying it to make it hemispherical. However, these methods require special machinery and require large equipment costs to increase production capacity.

On the other hand, a method for obtaining spherical products by dispersing a molten anti-aging agent in a solution consisting of a gel component of a hydrophilic polymer compound and water, and cooling and solidifying the dispersed particles while stirring (Japanese Patent Publication No. 448-3210 However, since this method uses a large amount of a hydrophilic polymer compound, the quality of the product deteriorates, and if the amount of hydrophilic polymer compound used is reduced, the yield of spherical products decreases. There are drawbacks such as extremely low carbon content, easy disintegration, and significant generation of fine powder.

In addition, powdered organic rubber chemicals are added in an amount of 0 to 30% by weight.
There is a method (Japanese Unexamined Patent Application Publication No. 1983-62245) in which the material is dispersed and heated in water containing an organic solvent and molded. This method requires two steps: once the product is taken out as a solid, it is turned into slurry again and then dried, which results in a large loss of time and cost, and also requires expensive solvents. There is.

For these reasons, the present inventors have developed an inexpensive, spherical product with a constant particle size that has excellent fluidity, low disintegration, and does not generate dust for the diphenylamine-based antiaging agent for rubber as described above. As a result of intensive research into a method for easily obtaining it with high yield, the present invention has been completed.

That is, in the present invention, a molten diphenylamine antioxidant is added to an aqueous solution containing a cationic surfactant so that the slurry concentration of the antioxidant becomes 5 to 40% by weight, and the mixture is stirred. do,
The present invention provides a method for obtaining a desired spherical product having a diameter of 1 to 6 mm in high yield by cooling and solidifying the product.

The amine-based anti-aging agent applied to the present invention is a conventionally known diphenylamine-based anti-aging agent for rubber that is solid at room temperature, and in particular, N-isopropyl-N'-phenyl-p-phenylene diamine,
and N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine are effectively applied.

The cationic surfactant used in the present invention is a conventionally known tetraalkylammonium chloride type surfactant. Benzyl trialkylammonium chloride type Alkylpicolinium chloride type Polyoxyethylene alkylamine type Examples include alkylamine salt type [R ₁ NH ₂ .CH ₃ COOH]. In the above formula, R ₁ is C ₈
~ _C24 alkyl group, _R2 is a _C1 - _C24 alkyl group,
n represents 1 to 10, respectively.

Specifically, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, cocoylbenzyldimethylammonium chloride, laurylpicolinium chloride, polyoxyethylene laurylamine, laurylamine acetate, etc. are exemplified, and these may be used alone or in combination of two or more. It is used as

When these cationic surfactants are present in an aqueous solution, the molten diphenylamine anti-aging agent is dispersed as spherical dispersed particles during the process of solidification, preventing agglomeration due to adhesion of these dispersions to each other. and becomes a spherical body with a smooth surface.
Excellent effects can be obtained, such as the generation of fine powder to be extremely small, and furthermore, reduction in yield due to adhesion to the walls of containers, stirring blades, etc. can be suppressed.

The amount of cationic surfactant to be used is not particularly limited, but the concentration in the aqueous solution is usually in the range of 0.001% to 5% by weight, preferably in a small amount of 0.01% to 2% by weight to achieve sufficient effect. Demonstrate.

The pH of the aqueous solution varies depending on the type of cationic surfactant used and the applied diphenylamine anti-aging agent, but is usually in the range of 5 to 13, preferably in the range of 6 to 10. The temperature of the aqueous solution may be below the freezing point of the applied diphenylamine anti-aging agent.

A spherical product is obtained by adding the diphenylamine anti-aging agent in a molten state to an aqueous solution containing such a cationic surfactant, stirring, and solidifying by cooling.

Here, the method of adding the molten diphenylamine anti-aging agent to the aqueous solution is not particularly limited, and may be added gradually or rapidly. However, in the present invention, since the molten anti-aging agent is stirred in an aqueous solution to be dispersed and solidified, the amount of diphenylamine-based anti-aging agent added to the aqueous solution is 5% by weight as the slurry concentration of the produced spherical products. The content should be ~40% by weight. Preferably, the slurry concentration is between 10% and 30% by weight. The particle size of the dispersed particles can be adjusted by arbitrarily changing the cooling rate and the strength of stirring.

Incidentally, it is effective to add seed crystals to the aqueous solution or melted diphenylamine anti-aging agent because it also accelerates the solidification rate.

Furthermore, in the present invention, an antifoaming agent may be added if necessary, and nonionic surfactants,
An amphoteric surfactant, a hydrophilic polymer compound, a flocculant, etc. may be added.

In this way, the molten diphenylamine anti-aging agent is dispersed as spherical dispersed particles in the aqueous solution.
The desired particle size is obtained. If the solidified spherical particles are separated from the aqueous solution, washed and dried, they will have a diameter of about 1
~6mm, with excellent fluidity and difficult to disintegrate,
Spherical products suitable for continuous metering and uniform blending are obtained with good yields.

The present invention will be explained below with reference to Examples. In the example,
Parts mean parts by weight.

Example 1 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was added to water.
When added over 1 minute to a solution at 40°C consisting of 500 parts and 0.6 parts of lauryltrimethylammonium chloride and stirred at room temperature for 30 minutes, the dispersed particles are completely solidified. When filtered, washed and dried, it has excellent fluidity and does not easily disintegrate, melting point 50℃, diameter 1-6
96 parts of spherical products of mm were obtained.

Example 2 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylene diamine, 0.6 parts of polyoxyethylene laurylamine (number of moles of ethylene oxide added: 5) and 500 parts of water.
When added to a solution at 40°C for 2 minutes and stirred at room temperature for 30 minutes, completely solidified spherical particles are produced.
After filtering, washing and drying, 98 parts of spherical products with a diameter of 1-5 mm were obtained.

Example 3 Molten N-isopropyl-N'-phenyl-
Adding 100 parts of p-phenylenediamine to a 70°C solution consisting of 600 parts of water and 1.5 parts of laurylamine acetate over 1 minute and stirring at room temperature for 20 minutes.
The dispersed particles are completely solidified. Filtered, washed and dried, has excellent fluidity and does not easily disintegrate, melting point 75
96 parts of spherical products with a diameter of 1 to 4 mm were obtained.

Example 4 Molten N-isopropyl-N'-phenyl-
100 parts of p-phenylenediamine was added over 1 minute to a solution at 70°C consisting of 400 parts of water and 1.0 part of stearyltrimethylammonium chloride, and the solution was stirred at room temperature.
Stirring for 20 minutes completely solidifies the dispersed particles.
Filtered, washed with water, dried, melting point 75℃, diameter 1-4mm
98 parts of spherical product were obtained.

Example 5 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was added over 1 minute to a solution at 45°C consisting of 1.5 parts of laurylpicolinium chloride and 500 parts of water.
After stirring for a minute, fully solidified spherical particles are formed. After filtering, washing and drying, 97 parts of spherical products with a diameter of 1 to 6 mm were obtained.

Example 6 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was added to cocoylbenzyldimethylammonium chloride.
When added to a solution of 1.5 parts and 500 parts of water at 45°C over 1 minute and stirred at room temperature for 1 hour, completely solidified spherical particles are produced. After filtering, washing and drying, 96 parts of spherical products with a diameter of 1-5 mm were obtained.

Claims (1)

[Claims] 1. A molten diphenylamine anti-aging agent is added all at once to an aqueous solution prepared by dissolving a cationic surfactant so that the slurry concentration of the anti-aging agent is 5 to 40% by weight, and the aging A method for producing a spherical product of an amine-based anti-aging agent, which comprises stirring until the inhibitor finishes solidifying, cooling and solidifying to obtain a spherical product with a diameter of 1 to 6 mm.