JP2007262044A - Method for producing p, p'-oxybis(benzenesulfonyl hydrazide) - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems: when hydrazine hydrate is dropped onto a p, p'-oxybis(benzenesulfonyl chloride) slurry and reacted, it takes time to finish the reaction to p, p'-oxybis(benzenesulfonyl hydrazide) and excess amount of hydrazine hydrate is required to shorten the reaction time, and the p, p'-oxybis(benzenesulfonyl hydrazide) solely having small particle sizes are obtained. <P>SOLUTION: By dropping p, p'-oxybis(benzenesulfonyl chloride) into hydrazine hydrate and increasing a reaction velocity, large sized particles are formed and p, p'-oxybis(benzenesulfonyl hydrazide) having particle sizes which can be easily regulated in a succeeding process is prepared in a short time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing P, P′-oxybis (benzenesulfonylhydrazide), which is a chemical foaming agent used for foaming rubber and plastics.

  In general, P, P′-oxybis (benzenesulfonylhydrazide) is produced by dropping hydrazine hydrate and aqueous ammonia into a slurry suspended in a solvent such as P, P′-oxybis (benzenesulfonylchloride) and water. Is done. (See Patent Document 1)

  When hydrazine hydrate is added dropwise to a P, P′-oxybis (benzenesulfonyl chloride) slurry and reacted, it takes time to complete the reaction up to P, P′-oxybis (benzenesulfonyl hydrazide), thereby reducing the time. This requires a large excess of hydrated hydrazine. In addition, the crystal nucleation time varies depending on the addition method and the addition conditions, and the method of adding hydrazine hydrate can obtain only small P, P'-oxybis (benzenesulfonylhydrazide) particles.

  If the reaction time is long, the production efficiency is poor, and even if the reaction time is shortened by using a large excess of hydrazine, it is necessary to treat the excess hydrazine waste liquid, resulting in poor economic efficiency. If the particles are large, the particle size can be adjusted by subsequent mechanical processing such as pulverization and classification, but if the particles are small, it is difficult to separate the liquid from the crystals, resulting in poor production efficiency and further adjustment of the particle size. Absent.

  JP-A-60-156662

Problems to be solved by the invention

  The object of the present invention is to solve the above-mentioned problems in the prior art, increase production efficiency and economy, and provide an appropriate one that facilitates the most important particle size adjustment as a chemical foaming agent in the subsequent steps. It is in.

Means for solving the problem

  As a result of intensive studies to solve the above problems, the inventors of the present invention dropped a suspension of P, P′-oxybis (benzenesulfonyl chloride) and a solvent such as water as needed into hydrazine hydrate. By increasing the reaction rate and forming a large crystal nucleus of P, P′-oxybis (benzenesulfonylhydrazide) that is generated at an early stage, the above-mentioned problems are solved, and production efficiency and economy are good. It was confirmed that P, P′-oxybis (benzenesulfonylhydrazide) having a size that can easily adjust the particle size can be obtained in this step, and the present invention has been achieved.

  That is, the present invention relates to a method for producing P, P′-oxybis (benzenesulfonylhydrazide) characterized in that production efficiency and economy are good and a suitable particle size is obtained as a chemical foaming agent.

  As P, P'-oxybis (benzenesulfonyl chloride), those synthesized from diphenyl oxide and sulfuric acid and phosphorus oxychloride or phosphorus trichloride or those synthesized from diphenyl oxide and chlorosulfonic acid can be used. In addition, a pulverized product can be used to improve the reactivity.

  P, P'-oxybis (benzenesulfonyl chloride) may be dropped as a powder in hydrazine hydrate, or suspended in a solvent such as water from the viewpoint of workability and added as a slurry. The slurry concentration is not particularly limited, but 5 to 60%, preferably 15 to 40% is preferable from the viewpoint of workability.

    The rate of adding P, P′-oxybis (benzenesulfonyl chloride) into hydrated hydrazine is 5 to 60 minutes, and further 15 minutes with respect to 1 mol of P, P′-oxybis (benzenesulfonyl chloride) with respect to 1 mol of hydrated hydrazine. ~ 30 minutes is preferred. If the rate of application is too fast, heat generation per hour is large, and cooling to maintain the temperature becomes difficult. On the other hand, if it is too slow, the reaction time becomes longer and the production time is longer, which is not economical.

  The concentration of hydrated hydrazine is preferably 5 to 100%, more preferably 10 to 80%, and even more preferably 30 to 60%. If the concentration is too low, the reactivity is slow and the reaction time is prolonged, resulting in a decrease in production efficiency. On the other hand, if the concentration is too high, the heat generated during the reaction increases, cooling is difficult and the reaction temperature cannot be maintained, and the yield decreases with decomposition.

  Hydrochloric acid by-produced in the reaction may be neutralized with hydrazine hydrate, or may be neutralized with ammonia, sodium hydroxide or the like.

In the present invention, the molar ratio of hydrated hydrazine to 1 mole of P, P′-oxybis (benzenesulfonyl chloride) is 4.0 to 6.0 when only hydrated hydrazine is used, and more preferably 4.2 to 4.8. preferable. If the molar ratio is too low, the reaction rate is slow and productivity decreases, and if it is too high, excess hydrazine must be treated and recovered.

When ammonia is used in combination, ammonia is used in an amount of 2.0 to 3.0 times mol with respect to P, P′-oxybis (benzenesulfonyl chloride) and reduced to 2.0 to 2.5 times mol of hydrazine hydrate. Can be done.

  In the present invention, P, P′-oxybis (benzenesulfonyl chloride) dropwise and the temperature during the reaction is preferably 10 to 70 ° C., more preferably 20 to 50 ° C. If the reaction temperature is too low, the reaction rate is slow and the production efficiency decreases, and the crystals obtained are also small. If it is too high, it will decompose and the yield will be lowered, which is not economical.

  Although there is no restriction | limiting in particular in the case of manufacture of P, P'-oxybis (benzenesulfonyl hydrazide) in this invention, Additives, such as an antifoamer and surfactant, can be added as needed.

  In the present invention, P, P′-oxybis (benzenesulfonylhydrazide) is separated by a centrifuge or a filter press after the reaction, washed with water, dried with an air dryer or a fluid dryer, and then air pulverized. The particle size can be adjusted by pulverization with a machine or the like and classification with a mechanical classifier.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The particle size measuring method and the decomposition temperature measuring method are as follows.

  The particle size measurement method of the present invention used a laser diffraction particle size distribution meter. The decomposition temperature was raised from 130 ° C. to 5 ° C./min using a melting point measuring device, and the temperature at which P, P′-oxybis (benzenesulfonylhydrazide) was decomposed was taken as the decomposition temperature.

Example 1
A thermometer and a stirrer were installed in a 4-necked Kolben, 250.0 g (2.0 mol) of 40% hydrazine hydrate was added, and the mixture was heated and stirred at 40 ° C. In another beaker, 174.9 g (0.476 mol) of P, P′-oxybis (benzenesulfonyl chloride) and 350 g of water were placed and stirred well to obtain a uniform 33% slurry. The slurry was dropped into 40% hydrazine hydrate with a tube pump for about 1 hour. During the dropping, heat was generated so that the temperature was not exceeded 45 ° C. After dropping, the temperature was further adjusted to maintain 40 ° C., and stirring was continued for 5 hours. Thereafter, it was filtered off with a Nutsche, washed and dried with a dryer. The crystal grain size after drying was measured and found to be 53 μm and the decomposition temperature was 160 ° C.

Comparative Example 1
The amount of each raw material, temperature transition, and time were the same as in Example 1 except that hydrazine hydrate was dropped into a slurry of P, P′-oxybis (benzenesulfonyl chloride) and water in about 1 hour. The crystals had a particle size as small as 20 μm and a decomposition temperature as low as 154 ° C.

Comparative Example 2
The reaction was performed in the same manner as in Comparative Example 1 except that the reaction was performed for 7 hours after the hydrazine hydrate was dropped. The crystals had a particle size of 18 μm and a decomposition temperature of 158 ° C.

Example 2
110 g (1.32 mol) of 60% hydrazine hydrate and 64 g (0.94 mol) of 25% aqueous ammonia were placed in a 4-necked Kolben and adjusted to 30 ° C. and stirred. In another beaker, 174.9 g (0.47 mol) of P, P′-oxybis (benzenesulfonyl chloride) and 450 g of water were added and stirred well to obtain a uniform 28% slurry. This slurry was dropped with a tube pump over about 30 minutes. The temperature was adjusted not to exceed 50 ° C. Other than that was carried out in the same manner as in Example 1. The crystals had a particle size of 38 μm and a decomposition temperature of 159 ° C.

Comparative Example 3
Except that 60% hydrazine hydrate and 25% ammonia water were simultaneously dropped into a slurry of P, P′-oxybis (benzenesulfonyl chloride) and water in about 30 minutes at the same time, the amount of each raw material, temperature transition, and time were as in Example 2. The same was done. The crystals had a particle size of 12 μm and a decomposition temperature of 153 ° C.

Comparative Example 4
After the hydrated hydrazine and aqueous ammonia were added dropwise, the reaction was performed in the same manner as in Comparative Example 3 except that the reaction was performed for 9 hours. The crystals had a particle size of 12 μm and a decomposition temperature of 157 ° C.

The invention's effect

  According to the present invention, it is possible to provide P, P′-oxybis (benzenesulfonylhydrazide) that has good production efficiency and economy and can be adjusted to a desired particle size by pulverization, classification, or the like.

Claims (5)

  A method for producing P, P'-oxybis (benzenesulfonyl hydrazide), characterized in that P, P'-oxybis (benzenesulfonyl chloride) is added to hydrazine hydrate at 70 ° C or lower.   The rate of adding P, P′-oxybis (benzenesulfonyl chloride) into hydrated hydrazine is 1-60 mol of hydrated hydrazine with 1 mol of P, P′-oxybis (benzenesulfonyl chloride) at 70 ° C. or less for 5 to 60 minutes. A method for producing P, P′-oxybis (benzenesulfonylhydrazide), which is added at a rate.   The method for producing P, P'-oxybis (benzenesulfonylhydrazide) according to claim 1 or 2, wherein the concentration of hydrated hydrazine is 5 to 100%.   The method for producing P, P'-oxybis (benzenesulfonylhydrazide) according to claim 1 or 2, wherein hydrated hydrazine and aqueous ammonia are used in combination.   The method for producing P, P'-oxybis (benzenesulfonylhydrazide) according to claim 1 or 2, wherein the reaction temperature is 40 to 60 ° C.