JPS6411056B2 - - 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 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 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 some 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.

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, then pulverized, turned into slurry, and dried again, resulting in a large loss of time and cost, and also requires expensive solvents. There are drawbacks such as.

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 to an aqueous solution prepared by dissolving an anionic surfactant so that the anti-aging agent slurry concentration is 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-phenylenediamine,
and N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine are effectively applied.

The anionic surfactant used in the present invention is a conventionally known alkylmethylaminocarboxylate type [R ¹ CON (CH ₃ ) (CH ₂ ) _o COOM] (R ¹ is C ₈ to _{C 24} alkyl group, n is 0 to 3, M
is an alkali metal), alkyl sulfate salt type [R ² OSO ₃ M] (R ² is a C ₈ to _{C 24} alkyl group, M is an alkali metal or NH ₄ group), alkylaryl sulfonate type [R ³ SO ₃ M] (R ³ is an aryl group substituted with a C ₈ to C ₂₄ alkyl group, M is an alkali metal), alkylnaphthalene sulfonate type [R ⁴ SO ₃ M] (R ⁴ is a C ₈ to C ₂₄ naphthalene group substituted with an alkyl group, M is an alkali metal), sulfosuccinate salt type [R ⁵ OOCCH (SO ₃ M) CH ₂ COOR ⁵ ] (R ⁵ is a C ₄ to C ₁₂ alkyl group, M is an alkali metal), polyoxyethylene alkyl or alkylaryl sulfate type [R ⁶ O (CH ₂ CH ₂ O) _o SO ₃ M] (R ⁶ is a C ₈ to C ₂₄ alkyl group or further substituted Examples include various anionic surfactants such as aryl group, n is 1 to 10, and M is an alkali metal.
Specifically, N-lauroyl-N-methyl-β-
Examples include sodium alanine, sodium cocoyl sarcosine, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium dodecylnaphthalenesulfonate, sodium dioctylsulfosuccinate, sodium polyoxyethylene lauryl ether sulfate, and sodium polyoxyethylene nonyl phenyl ether sulfate. These may be used alone or in combination of two or more.

When these anionic surfactants are present in an aqueous solution, the molten diphenylamine anti-aging agent is dispersed as spherical dispersed particles during the solidification process, and the agglomeration due to adhesion of these dispersion particles to each other is prevented. It has excellent effects such as being able to minimize the generation of fine powder and suppressing the drop in yield due to adhesion to the walls of containers, stirring blades, etc., as it becomes a spherical body with a smooth surface. can get.

The amount of anionic 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 anionic surfactant used and the diphenylamine anti-aging agent applied, 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 above diphenylamine anti-aging agent in a molten state to an aqueous solution prepared by dissolving such an anionic 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 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-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was added to water.
When added to a solution of 500 parts and 0.5 parts of ammonium lauryl sulfate at 40°C and stirred at room temperature for 30 minutes, the dispersed particles are completely solidified. After filtering, washing and drying, 98 parts of spherical products with excellent fluidity and resistance to disintegration, melting point 50° C. and diameter 1-6 mm were obtained.

Example 2 Molten N-1,3-dimethylbutyl-N'-
100 parts of phenyl-p-phenylenediamine was added over 2 minutes to a solution at 40°C consisting of 0.3 parts of sodium polyoxyethylene lauryl ether sulfate (number of moles added to ethylene oxide: 3) 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, 98 parts of spherical products with a diameter of 1-5 mm were obtained.

Example 3 Molten N-isopropyl-N'-phenyl-
When 100 parts of p-phenylenediamine is added to a 70°C solution consisting of 400 parts of water and 0.3 parts of sodium dodecylbenzenesulfonate and stirred at room temperature for 20 minutes, the dispersed particles are completely solidified. filtered, washed, dried, has excellent fluidity and does not easily disintegrate, has a melting point
96 parts of spherical products with a diameter of 1 to 4 mm were obtained at 75°C.

Example 4 Molten N-isopropyl-N'-phenyl-
Consisting of 100 parts of p-phenylenediamine, 500 parts of water and 0.2 parts of sodium dioctyl sulfosuccinate.
When added to a solution at 70°C and stirred at room temperature for 20 minutes, the dispersed particles will completely solidify. After filtering, washing with water and drying, 98 parts of spherical products with a melting point of 75°C and a diameter of 1 to 4 mm were obtained.

Example 5 Molten N-isopropyl-N'-phenyl-
100 parts of p-phenylenediamine, 400 parts of water and N-
Add it to a solution at 65℃ consisting of 0.3 parts of sodium lauroyl-N-methyl-β-alanine and let it stand at room temperature.
Stirring for 20 minutes completely solidifies the dispersed particles.
Filter, wash, dry, melting point 75℃, diameter 1-4mm
97 parts of spherical products were obtained.

Example 6 Molten N-1,3-dimethylbutyl-N'-
When 100 parts of phenyl-p-phenylenediamine is added to a solution at 45°C consisting of 0.3 parts of sodium cocoyl sarcosine and 500 parts of water over 1 minute and stirred at room temperature for 1 hour, completely solidified spherical particles are produced. . After filtering, washing and drying, 99 parts of spherical products with a diameter of 1-5 mm were obtained.

Example 7 Molten N-1,3-dimethylbutyl-N'-
When 100 parts of phenyl-p-phenylenediamine is added to a solution at 45°C consisting of 0.5 parts of sodium dodecylnaphthalene sulfonate and 500 parts of water and stirred at room temperature for 1 hour, completely solidified spherical particles are produced. After filtering, washing and drying, the diameter is 1 to 5 mm.
97 parts of spherical product were obtained.

Example 8 Molten N-isopropyl-N'-phenyl-
100 parts of p-phenylenediamine, 400 parts of water and sodium polyoxyethylene nonyl phenyl ether sulfate (number of moles of ethylene oxide added: 3)
Added to a solution of 0.15 parts at 70℃ and heated to 20℃ at room temperature.
Stirring for a minute completely solidifies the dispersed particles.
When filtered, washed and dried, it has a melting point of 75℃ and a diameter of 1 to 4 mm.
98 parts of spherical product were obtained.

Claims (1)

[Claims] 1. Add a molten diphenylamine anti-aging agent to an aqueous solution containing an anionic surfactant so that the slurry concentration of the anti-aging agent is 5 to 40% by weight, stir, and cool. A method for producing a spherical product of an amine-based antiaging agent, which comprises solidifying to obtain a spherical product with a diameter of 1 to 6 mm.