JPH0326219B2 - - 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 coal import, causing dust to scatter during use. There was a problem that the work environment was significantly deteriorated.

In particular, compounds with a low melting point such as N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine cause a phenomenon in which a small amount of powder solidifies into a block shape, so fine powder in the product is It is necessary to remove it 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 other problems.

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. 48-3210 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.

There is also a method (Japanese Unexamined Patent Publication No. 54-62245) in which a powdered organic rubber chemical is dispersed in water containing 0 to 30% by weight of an organic solvent, and then heated and molded. This method requires two steps: first taking out the product as a solid, then crushing it, turning it into slurry again, and drying it, which results in a large loss of time and cost, and also requires expensive solvents. There are drawbacks.

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 anti-aging agent is added all at once to an aqueous solution prepared by dissolving a nonionic surfactant so that the anti-aging agent slurry concentration is 5 to 40% by weight. The present invention provides a method for obtaining a desired spherical product having a diameter of 1 to 6 mm in a high yield by stirring the anti-aging agent until the solidification is completed, and 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-isopropyl-N'-phenyl-p-phenylenediamine. -1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine is advantageously applied.

The nonionic surfactant used in the present invention is a conventionally known polyoxyethylene alkyl ether type [R ¹ O (CH ₂ CH ₂ O) _o H] (R ¹ is a C ₈ to C ₁₈ alkyl group). , n is 1 to 100), polyoxyethylene alkylaryl ether type [R ² O (CH ₂ CH ₂ O) _o H] (R ₂ is a C ₈ to C ₂₄ alkylaryl group which may be further substituted, n is 1 to 100), polyoxyethylene acyl ester type [R ₃ COO (CH ₂ CH ₂ O) _o H] (R ³ is C ₈ to _{C 24} , n is 1 to 100), fatty acid alkylolamide type [ R ⁴ CONHCH ₂ CH ₂ OH] and [R ⁴ CON(CH ₂ CH ₂ OH) ₂ ] (R ⁴ is C ₈ C ₂₄ ), ethylene oxide addition type of fatty acid alkylolamide [R ⁵ CONHC ₂ H ₄ O ( C ₂ H ₄ O) _o H] (R ⁵ is C ₈ to C ₂₄ , n is 2 to 10), and various nonionic surfactants can be mentioned.
Specific examples include polyoxyethylene lauryl ether, polyoxyethylene nonyl phenyl ether, lauric acid diethanolamide, coconut oil fatty acid monoethanolamide ethylene oxide adduct, and polyethylene glycol monooleate. These may be used alone or in combination of two or more.

When these nonionic 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 powders can be made extremely small, and furthermore, a decrease in yield due to adhesion to the walls of containers, stirring blades, etc. can be suppressed.

The amount of nonionic 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, and preferably in a small amount of 0.01% to 2% by weight to achieve sufficient effect. Demonstrate. Further, 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 above diphenylamine anti-aging agent in a molten state to an aqueous solution prepared by dissolving such a nonionic surfactant, stirring, and cooling to solidify.

Here, the molten diphenylamine anti-aging agent is added all at once to the aqueous solution. In the present invention, the molten anti-aging agent is stirred in the aqueous solution to be dispersed and solidified, so the amount of the 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 dissolved diphenylamine anti-aging agent because it also accelerates the solidification rate.

Furthermore, in the present invention, an antifoaming agent may be added as necessary, and cationic surfactants, amphoteric surfactants, anionic surfactants, hydrophilic polymer compounds, flocculants, etc. It's okay.

In this way, the molten diphenylamine anti-aging agent is dispersed as spherical dispersed particles in the aqueous solution.
The desired particle size is achieved. 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-isopropyl-N'-phenyl-
100 parts of p-phenylenediamine, 500 parts of water and 1.0 part of polyoxyethylene nonyl phenyl ether (number of moles of ethylene oxide added: 100) at 70°C.
When added to the solution and stirred at room temperature for 20 minutes, the dispersed particles will completely solidify. When filtered, washed and dried, it has excellent fluidity and does not easily disintegrate, with a melting point of 75.
96 parts of spherical products with a diameter of 1 to 4 mm were obtained.

Example 2 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylene diamine was added over 2 minutes to a solution at 40°C consisting of 1.3 parts of polyoxyethylene nonyl phenyl ether (5 moles of ethylene oxide added) and 500 parts of water, and the mixture was heated to 30°C at room temperature.
After stirring for a minute, fully solidified spherical particles are formed. After filtering, washing and drying, 95 parts of spherical products with a melting point of 50 DEG C. and a diameter of 1 to 6 mm were obtained.

Example 3 Molten N-isopropyl-N'-phenyl-
When 100 parts of p-phenylenediamine was added to a solution at 70°C consisting of 400 parts of water and 0.8 parts of polyoxyethylene lauryl ether (50 moles of ethylene oxide added) and stirred at room temperature for 20 minutes, the particles were completely dispersed. solidifies. Filtered, washed and dried, has excellent fluidity and does not easily disintegrate, melting point 75℃, diameter 1
96 parts of spherical products of ~4 mm were obtained.

Example 4 Molten N-isopropyl-N'-phenyl-
When 100 parts of p-phenylenediamine is added to a solution at 70°C consisting of 500 parts of water and 1.5 parts of polyethylene glycol distearate (100 moles of ethylene oxide added) and stirred at room temperature for 20 minutes, the particles are completely dispersed. solidifies. After filtering, washing with water and drying, 97 parts of spherical products with a melting point of 75°C and a diameter of ~4 mm were obtained.

Example 5 Molten N-isopropyl-N'-phenyl-
When 100 parts of p-phenylenediamine was added to a solution at 42°C consisting of 400 parts of water and 12 parts of polyethylene glycol monooleate (number of moles of ethylene oxide added: 10) and stirred at room temperature for 30 minutes, the particles were completely dispersed. solidifies. filtered, washed, dried, melting point
97 parts of spherical products with a diameter of 1 to 6 mm were obtained at 75°C.

Example 6 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was added over 1 minute to a solution at 40°C consisting of 1.0 part of coconut oil fatty acid diethanolamide and 500 parts of water.
After stirring for a period of time, fully solidified spherical particles are produced. After filtering, washing and drying, 99 parts of spherical products with a diameter of ~5 mm were obtained.

Example 7 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was mixed with an oxyethylated product of coconut oil fatty acid monoethanolamide (number of moles of ethylene oxide added: 2) 1.2
When added to a solution of 500 parts of water at 40°C and stirred at room temperature for 1 hour, completely solidified spherical particles are produced. After filtering, washing and drying, the diameter of
97 parts of 5 mm spherical products 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 nonionic 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 the product to obtain a spherical product with a diameter of 1 to 6 mm.