JPH06329601A - Stabilization of 4-nitrosodiphenylamine hydrochloride solution - Google Patents

Abstract

PURPOSE:To suppress the decomposition of 4-nitrosodiphenylamine hydrochloride and relatively stably keep a 4-nitrosodiphenylamine hydrochloride solution for a long period. CONSTITUTION:Nitrogen monoxide gas is added to the vapor phase on a 4- nitrosodiphenylamine hydrochloride solution at a concentration of >=10%. 4- Nitrosodiphenylamine hydrochloride is produced by the rearrangement of N- nitrosodiphenylamine with hydrogen chloride or the reaction of diphenylamine with a nitrosation agent (e.g. nitrosyl chloride or alkyl nitrite) and hydrogen chloride at the same time. The compound is present in the solvent used in the above production process in the form of a slurry of 10-40wt.% concentration.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for stabilizing a 4-nitrosodiphenylamine hydrochloride solution. For details, 4
-A method for inhibiting the decomposition of nitrosodiphenylamine hydrochloride. The 4-nitrosodiphenylamine hydrochloride obtained according to the present invention is an antioxidant used in rubber products,
It is a particularly useful compound as an anti-ozone agent and an intermediate for producing dyes.

[0002]

It is well known that 4-nitrosodiphenylamine hydrochloride is thermally unstable. Japanese Patent Office Sho 5
No. 7-35182 discloses a method of using a mixed solvent in which the ratio of aromatic hydrocarbon to methanol is increased in order to prevent decomposition of 4-nitrosodiphenylamine hydrochloride. The JP 59-82349, a method of using a C ₅ -C ₁₀ stabilizer and solvent saturated alcohols of 4-nitrosodiphenylamine hydrochloride is disclosed.

[0003]

However, the Japanese Patent Publication No. 57-
No. 35182 solvent system does not stabilize 4-nitrosodiphenylamine hydrochloride, only slowing down the rate of decomposition. According to this method, about 50% of 4-nitrosodiphenylamine hydrochloride in solution decomposes at 40 ° C. for 6 hours. In JP-A-59-82349, it is relatively stable at a temperature of 30 ° C. or lower, but 4
At a temperature of 0 ° C. or higher, the stability drops sharply.

[0004]

Means for Solving the Problems As a result of extensive studies on the cause of the decomposition reaction, the present inventors found that nitric oxide gas was made to exist in the gas phase part on the 4-nitrosodiphenylamine hydrochloride solution, and thereby 4-nitroso The present invention has been accomplished by finding that the decomposition of diphenylamine hydrochloride is suppressed.

That is, the present invention is a method for stabilizing a 4-nitrosodiphenylamine hydrochloride solution, characterized in that nitric oxide gas is allowed to exist in the gas phase portion of the 4-nitrosodiphenylamine hydrochloride solution.

The present invention will be described in detail below. The concentration of nitric oxide (hereinafter referred to as NO) gas present in the gas phase portion of the 4-nitrosodiphenylamine hydrochloride solution is about 1
It may be 0% or more, and pure NO gas or a mixed gas of nitrogen, air, helium, argon and the like is used.

4-nitrosodiphenylamine hydrochloride is
It is usually present as a slurry in the solvent used in preparing 4-nitrosodiphenylamine hydrochloride. The solvent is an alcohol such as methanol, ethanol, propanol, butanol, hexanol, octanol or 2-ethylhexanol, or a mixed solvent of these alcohols and an aromatic hydrocarbon such as benzene, toluene or xylene.

The amount of solvent in the 4-nitrosodiphenylamine hydrochloride solution is such that the concentration of 4-nitrosodiphenylamine hydrochloride is in the range of 10 to 40 wt%.

The 4-nitrosodiphenylamine hydrochloride solution is prepared by mixing diphenylamine with nitrosyl chloride, a mixed gas of nitric oxide (a mixed gas of NO, NO ₂ , N ₂ O _3, etc., hereinafter referred to as NOx gas), sodium nitrite or nitrous acid. N-nitrosodiphenylamine is formed by alkyl, and hydrogen chloride gas is introduced into this for rearrangement, or nitrosation is performed on diphenylamine hydrochloride with NOx gas, or NOx gas and hydrogen chloride gas are simultaneously introduced to diphenylamine to nitrosate. can get. Normally, 4-nitrosodiphenylamine hydrochloride is neutralized with an alkali and then reduced with hydrogen to give 4
-Converted to aminodiphenylamine.

[0010]

According to the present invention, the decomposition of 4-nitrosodiphenylamine hydrochloride can be suppressed, and the 4-nitrosodiphenylamine hydrochloride solution can be retained relatively stably for a long time.

[0011]

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. Example 1 33.8 g (0.20 mol) of diphenylamine was added to 100 ml of toluene and 100 ml of 2-ethylhexanol.
The mixture was added to the mixed solvent of 1), maintained at 30 ° C., and while stirring, hydrogen chloride gas of 14.6 g (0.40 mol) was blown in through the gas introduction tube for about 30 minutes. Then at the same temperature, N
O (100 ml / min) and O ₂ (25 ml / min)
NOx gas (N: O = 0.67:
1) was bubbled through the gas inlet tube into the reaction mixture for 60 minutes. After blowing, the reaction was continued at 30 ° C. for 2 hours. The resulting 4-nitrosodiphenylamine hydrochloride solution was added to 50
The temperature was raised to 0 ° C., the gas phase part was replaced with NO gas, the change with time of 4-nitrosodiphenylamine hydrochloride was measured, and the residual rate was obtained. The results are shown in Table 1.

Example 2 33.8 g (0.20 mol) of diphenylamine was added to 100 ml of toluene and 100 ml of 2-ethylhexanol.
Was added to the mixed solvent of and kept at 20 ° C., and stirred for 20
% Sulfuric acid 100 g was added dropwise over about 15 minutes. Then, at the same temperature, 100 g of a 15% sodium nitrite aqueous solution was dropped into the reaction mixture over 60 minutes. After dropping, 3 at 20 ℃
The reaction was continued for 0 minutes. After the reaction was completed, the aqueous phase was separated, and the organic phase was kept at 30 ° C. with stirring and hydrogen chloride gas 14.1
g (0.39 mol) was blown in through the gas introduction tube for about 30 minutes. After blowing, the reaction was continued at 30 ° C. for 2 hours. The temperature of the generated 4-nitrosodiphenylamine hydrochloride solution was raised to 50 ° C., and the gas phase part was replaced with NO gas,
The change with time of -nitrosodiphenylamine hydrochloride was measured and the residual rate thereof was determined. The results are shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated except that the gas phase was replaced with nitrogen gas. The results are shown in Table 1.

Comparative Example 2 The procedure of Example 1 was repeated except that the gas phase was replaced with air. The results are shown in Table 1.

[0015]

[Table 1]

Claims (5)

[Claims] 1. A method for stabilizing a 4-nitrosodiphenylamine hydrochloride solution, which comprises allowing nitric oxide gas to exist in a gas phase portion of the 4-nitrosodiphenylamine hydrochloride solution. 2. The method for stabilizing a 4-nitrosodiphenylamine hydrochloride solution according to claim 1, wherein the 4-nitrosodiphenylamine hydrochloride is 4-nitrosodiphenylamine hydrochloride obtained by rearranging N-nitrosodiphenylamine with hydrogen chloride. . 3. The stable 4-nitrosodiphenylamine hydrochloride solution according to claim 1, wherein the 4-nitrosodiphenylamine hydrochloride is 4-nitrosodiphenylamine hydrochloride obtained by simultaneously reacting diphenylamine with a nitrosating agent and hydrogen chloride. Method. 4. The 4-nitrosodiphenylamine hydrochloric acid according to claim 2, wherein the N-nitrosodiphenylamine is N-nitrosodiphenylamine obtained by reacting diphenylamine with a nitric oxide mixed gas or sodium nitrite in the presence of an acid. A method for stabilizing a salt solution. 5. The method according to claim 3, wherein the nitrosating agent is nitrosyl chloride, a mixed gas of nitric oxide and alkyl nitrite.
-A method for stabilizing a nitrosodiphenylamine hydrochloride solution.