JPH10130227A - Aqueous solution of potassium ethylenebis(dithiocarbamate) having stability to low-temperature crystallization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous solution of potassium ethylenebis(dithiocarbamate) of 30-60wt.% concentration which has the stability resisting to crystallization precipitation even at a lowered temperature of 0 deg.C to -20 deg.C. SOLUTION: When sodium ethylenebis(dithiocarbamate) which is usually used is converted to potassium ethylenebis(dithiocarbamate), the aqueous solution of potassium ethylenebis(dithiocarbamate) shows the solution stability resisting to crystallization precipitation caused by outer stimulation even in a high concentration of 30-60wt.% and at lowered temperature of 0 deg.C--20 deg.C. Thus, the potassium salt aqueous solution can be handled with economical advantage, for example, in storage, transportation and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous solution of potassium diethyldithiocarbamate containing 30 to 62% by weight of potassium diethyldithiocarbamate and having crystallization stability even at a low temperature of 0 to -20 ° C.

[0002]

2. Description of the Related Art Dithiocarbamates have been conventionally used as vulcanization accelerators for rubber, fungicides for agricultural and horticultural use and extreme pressure additives for lubricating oils.

In recent years, pollution caused by heavy metal pollution has been regarded as a problem, and has been regulated by law. In the case of incinerated ash, smoke washing wastewater, fly ash, etc. discharged from incinerators of heavy metals, industrial waste and general waste in factory wastewater. Dithiocarbamate is also used as an agent for treating heavy metals in water-insoluble solids.
Since dithiocarbamate as this type of heavy metal treating agent is used in an aqueous solution, it is generally used as a concentrated solution in terms of transportation and storage. However, in recent years, there has been a strong demand from the waste treatment plant industry for a stable concentrated aqueous solution which does not crystallize even at a low temperature of −10 ° C. or lower especially in cold regions.

However, according to the findings of the present inventors, an aqueous solution of sodium diethyldithiocarbamate, which has been conventionally and generally used as a heavy metal treating agent, is shown in Table 1.
It is very difficult to maintain a stable state in which crystals are not precipitated as an aqueous solution of 25% by weight or more at a low temperature of from 0 to 0 ° C. On the other hand, JP-A-8-41017 discloses that at least one of xanthate, thiourea, and a dithiocarbamate different from the dithiocarbamate is used in an amount of 0.5 to 5 parts by weight per 100 parts by weight of a concentrated aqueous solution of the dithiocarbamate. Although an aqueous solution of dithiocarbamate having low-temperature stability by adding parts by weight is disclosed, operation complexity and quality problems due to the addition of xanthate and the like to a concentrated aqueous solution of dithiocarbamate, and the accompanying economics are disclosed. There is a problem with sex.

[0005]

The present invention contains 30 to 62% by weight of potassium diethyldithiocarbamate,
It is an object of the present invention to provide an aqueous solution of potassium diethyldithiocarbamate having crystallization stability at a low temperature of 0 ° C. to the art without problems in operational complexity and quality, such as addition of other chemicals, and economical problems associated therewith. .

[0006]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies to solve the above problem. As a result, sodium diethyldithiocarbamate, which has been generally used as a heavy metal treating agent, has been replaced with diethyldithiocarbamate. By changing to potassium, the concentration is 30-62.
We succeeded in obtaining an aqueous solution of potassium diethyldithiocarbamate having a high concentration of 1% by weight and a stability that does not crystallize against external stimuli even at a low temperature of 0 ° C to -20 ° C, and based on this finding, complete the present invention. Reached. Since the aqueous solution of potassium diethyldithiocarbamate of the present invention can be produced by using a known method for synthesizing a metal salt of diethyldithiocarbamate, it does not need to be mixed with other chemicals, and accordingly, there is a problem in operation complexity and quality. It is considered that there is no problem in economy.

If the concentration of the aqueous solution of potassium diethyldithiocarbamate according to the present invention is less than 30% by weight, the concentration of
If the concentration exceeds 62% by weight, potassium diethyldithiocarbamate may be crystallized even at 0 ° C. or more, which causes a problem in use. The effects of the present invention will be described below with reference to examples, but the claims of the present invention are not limited to the embodiments.

[0008]

【Example】

Example 1 An aqueous solution of potassium diethyldithiocarbamate of the present invention and an aqueous solution of sodium diethyldithiocarbamate of Comparative Example were synthesized by known methods, and their concentrations were determined by the officially approved pesticide control method based on the Pesticide Control Law. (Announced in November 2011)-. The crystal precipitation temperature shown in Table 1 was determined using a test tube (size: 25 mm in diameter, 280 mm in length) in which 30 ml of each aqueous solution of potassium diethyldithiocarbamate of the present invention and sodium diethyldithiocarbamate of the comparative example were placed, and the sample was placed. The measurement was carried out in accordance with JIS K 0065-1992 (method of measuring the solidification point of chemical products). In order to prevent the sample from being crystallized and being stabilized by supercooling, the test was performed with occasional stirring from the start to the end of the test. The reason for this is that when the sample stabilized by supercooling is transported by a pipe or the like, there is a possibility that the sample may be crystallized by stimulation. The above measurement results are shown in Table 1.

[0009]

[Table 1]

[0010]

According to Table 1, in order to have a crystallization temperature of 0 ° C. or less, the concentration of sodium diethyldithiocarbamate aqueous solution of Comparative Example is 25% by weight or less. On the other hand, the aqueous solution of potassium diethyldithiocarbamate of the present invention can be maintained at a concentration of not more than 62% by weight and a stable aqueous solution which does not crystallize against external stimuli. That can be handled.

Claims (1)

[Claims] (1) potassium diethyldithiocarbamate:
An aqueous solution of potassium diethyldithiocarbamate containing 0 to 62% by weight and having crystallization stability even at a low temperature of 0 ° C to -20 ° C.