CS259213B1 - The method of analysis of anionic components in raw materials for the preparation of rubber accelerators - Google Patents

Abstract

The solution relates to a method for the analysis of anionic components in raw materials for the preparation of rubber accelerators based on 2-mercaptobenzothiazole. The analyzed anionic components are separated in an isotachophoretic column by an electrolyte. The leading electrolyte contains 0.001 to 0.012 mol.l-1 of an anion with at least the same mobility as the analyzed components and counterions with buffering acid-base properties in the pH range of 2.1 to 10.3 and the terminating electrolyte contains an anion with a maximum of the same mobility as the analyzed components, or the counterion of the leading electrolyte is neutralized with sodium, potassium, calcium or barium hydroxide to a pH approximately equal to the pH of the leading electrolyte. After the detection of the analyzed components in their zones, the identification or determination of the content of the components in the analyzed sample is carried out from the measured detector signal or from the lengths of the zones of the analyzed components.

Description

259213

BACKGROUND OF THE INVENTION The present invention relates to a method for the analysis of anionic constituents in raw materials for the preparation of 2-mercaptobenzothiazole-based rubber accelerators, e.g. 2-mercaptobenzothiazole, 2-benzothiazole sulfenate, 2-benzothiazole sulfane, 2-benzothiazole sulfonate, N-morpholine sulfate, sulfite, formate, sulfate. , ticsulfate, chlorate and the like. isotachophoresis.

Rubber chemicals based on 2-mercaptobenzothiazole have the widest application in the rubber industry for the processing of rubber compounds of natural or synthetic rubber, used for the production of tires, rubber wool, conveyor belts, wedge-shaped belts, latex cables, rubber hoses. 2-mercaptobenzothiazole is also used in the pharmaceutical industry in the manufacture of medicated ointments and is also useful as a chemical analytical reagent.

The analyzed anionic components are the admixture products of the reaction mixture from the chemical preparations for the chemical industry - N-morpholinyl-2-benzothiazolylsulphenamide and N-cyclohexyl-2-benzothiazolylsulphenamide are most often prepared by the oxidation-condensation reaction of 2-mercaptobenzothiazolus with morpholine and the like. cyclohexylamine using oxidizing reagents such as hydrogen peroxide, sodium hypochlorite or oxygen. Basic raw materials for the production of 2-mercaptobenzothiazolus aniline, diatomaceous earth and sodium salt. Chlorate is a blend in technical hypochlorite.

For the determination of 2-mercaptobenzothiazole, it is possible to use its precipitation reactions with solamics to form insoluble products or soluble complexes suitable for gravimetric or titration methods (e.g. merkurimetriaú. The reductive property of the mercapto group can be used in electrochemical methods (polarography) as well as in volumetric iodine-titration methods.

Volumetric alkalimetry, spectrophotometry, liquid chromatography may also be used to determine 2-mercaptobenzothiazole. The biggest disadvantage of volumetric analytical methods and spectrometry is non-selectivity. Titration-oxidation-reduction methods such as iodometry can be used to determine the chlorate.

The analysis of 2-benzothiazole sulfonate, 2-benzothiazole sulfenate, 2-benzothiazole sulfonate, N-morpholine sulfate, sulfate, sulfite, thiosulfate, formate, as well as chlorate in 2-mercaptobenzothiazole-based accelerator samples is not known from the available literature. It is mainly due to the fact that we have achieved the known non-selective and non-separating methods do not allow! their determination in a mixture, with respect to the representation of the ingredients and their similar but also diverse properties. The above mentioned facts make it impossible to operatively analyze the individual stages of the technological process of production of rubber-based accelerators based on 2-mercaptobenzothiazole.

It has now been found that the analysis of anionic constituents in raw materials for the preparation of rubber-based 2-mercaptobenzothiazole based accelerators / in feedstocks, intermediates and end products (e.g. 2-mercaptobenzithiazole, 2-benzothiazole sulfonate, 2-benzothiazolufenane, 2-benzothiazol sulfane, N- morpholine sulphate, sulphate, sulphite, thiosulphate, formate, chlorate, and the like. podetekci! In their zones, conductivity, spectrophotometric, graphient-potential, thermal high-frequency conductivity, pH or radiation detectors may be carried out in accordance with the invention, which is based on a novel and different principle to that previously used.

The essence of the invention is that the separation of the analyzed anionic components is carried out in an isotachophoretic column at an electric current intensity of 7 to 400 A, with a conducting electrolyte containing 0.001 to 0.012 mol.l anion with at least the same stiffness as the analyzed components and counter-ions with acid-base buffering properties. pH 2.1 to 10.3, e.g., a solution of hydrochloric acid in a mixture of glycine, glycylglycine, beta-alanine, 6-aminocaproic acid, creatinine, histidine, hlididine-methyl ester, imidazole, glycylhistidine, trishydroxymethylaminomethane, 2-amino-2 -methylpropane-1,3-diol, arginine, and the like.

Separation of the analyzed components is carried out with an electrolyte terminating salium, 3 259213 containing an anion with the same mobility as the analyzed components, e.g. acetic acid, glutamic acid, caprylic, caprylic, mofrolimethanesulfonic, diethylcarbitol, 6-aminocaproic acid, glycine, beta-alanine ap which may be a counter-electrolyte counterion, sodium, potassium, calcium or barium hydroxide counterbalanced to a pH approximately equal to the pH of the conducting electrolyte. After detecting the analyzed components in their zones from the measured detector signal or from the lengths of the zones of the components analyzed, it will identify or determine the content of the components in the analyzed sample.

Under certain analysis conditions, which are expressed by the so-called analysis / composition operating system and guide electrolyte concentration, electric current intensity, geometric dimensions of the isotachophoretic column used, etc., the measured detector signal is in the corresponding zone of the separated substance mainly in the qualitative analysis of the substances where it is sufficient to measure the wave height of the isotachophoresis recorded by the recorder and compare it to the wave height of the predicted standard substance.

The measure of quantity in isotachophoretic analysis is again the zone length of the analyte. The easiest way to perform quantitative analysis is by using the calibration curve method.

An analysis assay system that can be advantageously used in the analysis of the subject anionic components of the invention is shown in Table 1.

The analysis of the anionic components in question according to the invention has a number of advantages. It makes it possible to carry out both quantitative and qualitative analysis of the anionic components in question in one of the solutions to be analyzed / solution of the components analyzed in water, extracting the components from the organic solvent into water / without chemical derivatization. analyzed components, with isotachophorogram evaluation, isotachophoretic separation. Other advantages are selectivity, speed and simplicity.

Some components in rubber accelerator material samples, raw materials and intermediates for their production are non-ionic substances, and I cannot interfere with the analysis of the subject ionic components as opposed to, for example, gas or liquid chromatography, where components can be analyzed irrespective of the ionogenicity and sign of charge of the components and in multiple the occurrence of components in the analyzed samples may result in undesirable coatings of the concentration elution bands of the components in their separation.

According to the present invention, it is possible to carry out an analysis of the anionic components of interest in their separation from undesired non-polar impurities in the analyzed samples, which purify the isotachophoretic columns, by simply extracting the analyzed components from the organic solvent into an acidified or alkaline aqueous solution, thereby increasing the selectivity of the analysis.

The advantages as well as the fact that the method of analysis according to the invention allows simultaneous, rapid, accurate and technically unpretentious quantitative and qualitative determination of allanionic components present in the sample, provides a wide range of its applications in the complex process control of the manufacturing process of the 2-mercaptobenzothiazole base accelerator, where so far known procedures have limited use.

The following examples illustrate, but do not limit the invention. Attached

Determination of 2-mercaptobenzothiazole, chlorate, 2-benzothiazole sulfonate and 2-benzothiazole sulfenate in mother liquor from the preparation of N-cyclogexyl-2-benzothiazole sulfenamide 259213

About 0.5 g of the sample was weighed into a 250 ml volumetric flask and the volume of the solution was adjusted to the mark. From this solution, 5 ml was injected into the isotohophoretic column. The isotachophoretic analysis was performed under operating system # 8 conditions in Table 1.

The length of the zones of the individual components analyzed was subtracted from the isotachofereogram and subtracted / respected from the calibration curve. the calibration equation was used to calculate / concentrate the components in the analyzed solution and calculate the content of the components in the sample.

The calibration curves were constructed as a dependence of the measured zone length of the analyte in question on the isotachophoresis of the analyte, from 1, 2, 3, 4 and 5 ml of the standard component solution injected into the isotachophoretic column.

-X at a concentration of 0.01 mol -1

Calibration dependencies in the form of linear equations were obtained by regression analysis. Example 2

Determination of thiosulphate, sulphate, formate, sulphite, N-morpholine sulphate, 2-benzothiazole sulphonate, 2-benzothiazole sulphane and 2-benzothiazole sulphane in the mother liquor of N-morpholinyl-2-benzothiazolylsulphenamide

Approximately 0.6 g of the sample was weighed into a 50 ml volumetric flask and the volume of the solution was adjusted to the mark. A 20 L solution was used for isotachophoretic analysis.

Isotachophoretic analyzes were performed under the conditions of operating system # 3, 4, 5a7 shown in Table 1.

The isotachopheritic analysis was performed as in Example 1. Example 3

Determination of 2-benzothiazole sulphonate, N-morpholino sulphate, sulphates in waste water from the production of N-morpholinyl-2-benzothiazolylsulphenamide.

About 1 g of the sample was weighed into a 50 ml volumetric flask and the volume of the solution was adjusted to the mark. 20 ml of solution was used for isotachophoretic analysis.

Isotachophoretic analysis was performed under operating system # 6 conditions of Table 1.

Isotachophoretic analysis was performed as in Example 1.

Example4

Determination of 2-mercaptobenzothiazole, N-morpholinosulfate, 2-benzothiazole sulfonate, 2-benzothiazole sulfane in the mother liquor from the preparation of N-morpholinyl-2-benzothiazolylsulfenamide. the isotachophoretic analysis is carried out in the same way as in Example 2, respectively. 1.

Isotachophoretic analyzes were performed under operating system conditions # 8, 10, 11 and 12. Example 5

Determination of sulphates, formates, N-morpholinosulphate, 2-benzothiazole sulphonate in mother liquor from the preparation of N-morpholinyl-2-benzothiazolylsulphonamide x v 5 259213 Preparation of the sample solution for analysis or analysis. the evaluation of the isotachophoretic analysis was carried out in the same way as in Example 2, respectively. 1.

Isotaohophoretic analysis was performed under operating system # 1, 2, 3, 4, 5, 7, and 9. Example 6

Determination of sulphates, formates, N-morpholine sulphate, 2-benzothiazole sulphonate, 2-benzothiazole sulfinane in distillation residues from the preparation of N-morpholinyl-2-benzothiazolylsulphenamide in its final product.

About 0.5 g of the sample was weighed into a 250 ml volumetric flask, 25 ml of chloroform was added precisely and, after dissolution of the sample, 5 ml of 0.5 mol / L KOH solution was added and the solution was adjusted to volume with water. The contents of the flask were shaken for about 5 minutes and after separation of the layer into an isotachophoretic column, 5 L of the aqueous layer was injected.

Calibration solutions for calibrating calibration curves or calibrating calibrators were prepared by measuring 25 ml chloroform, 5 ml 0.5 mol.l ”into 250 ml volumetric flasks! KOH solution, 0.2; 0.4; 0.6; 0.8: to 1.0 g of the standard chemical components and the volume of the solution was adjusted to 250 ml with water. The flask contents were shaken for 5 minutes and 1, 2, 3, 4, 5 and 5 L of the solution were injected into the isotachophoretic column after separation of the layers.

Isotachophoretic analyzes were performed under operating system # 7 conditions as shown in Table 1.

Analysis analysis was performed as in Example 1. Example 7

Determination of sulphates, formates, chlorates, 2-benzothiazole sulphonate in distillation products from the preparation of N-cyclohexyl-2-benzothiazolylsulphonamide or in its final product. Sample preparation for analysis, condition, isotachophoretic analysis and evaluation analysis were the same as in Example 6. 259213 I Ο Ο <*> Η * &amp; * U ο <; ο '1-3 ° υ ο m m m «« «« «« «« 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 +

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Φ 1 1 Μ υ υ υ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 04 β

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«© S3 X 0 H» 0 0 c-4, 0 «β 0 · Η K> 0 -H • hg +) β S« Μ »0 s 0 0 0 0 MB Λί MB> o λ a. Ε Ε = electrolyte, VE = electrolyte guide, DE = electrolyte terminator, GL = glycine, G1G1 = glycylglycine, BALA = beta-alanine, AKON = 6-aminocaproic acid, KRE = creatinine, HISM = hitidine methyl ester, HIS = histidine, IMID = imidazole, GIHIS = glycylhistidine TRIS = trishydroxymethylamino methane, AMOL = 2-amino-2-methylpropane-1,3-diol, ARG = arginine, KO = ocotic acid, KG1 = glutamic acid, KKON = capric acid, KKYL = caprylic acid DEB = diethylbarbituric acid, MES = N-morpholine-ethanesulfonic acid, x = pH of the solution is not checked.

Claims (1)

OBJECT OF THE INVENTION * A method of analyzing anionic constituents in raw materials for the preparation of 2-mercaptobenzothiazole rubber accelerator bases, e.g. chlorate by detecting the analyzed components in their zones by a conductivity, spectrophotometric, gradient - potential, thermal, high frequency - conductivity, pH butboradiation detector, characterized in that the separation of the analyzed anionic components in the isotachophoretic column at an electric current of between 7 and 400 A, s a conducting electrolyte containing 0.001 to 0.012 mol.l-1 of anion with at least the same mobility as the analyzed components and counter-ions having an acid-base buffering activity in the region of H 2, 1, 1, 10, 10, e.g., a hydrochloric acid solution with glycine, glycylglycine, beta -alanine, 6-aminocaproic acid, creatinine, bistidine, bistidine methyl ester, imidazole, glycylbistidine, bishydroxymethylaminomethone, 2-amino-2-methylpropane-1,3-diol, orginin and a terminating electrolyte containing the same mobility anion, such as the components analyzed, e.g. glutame, capronic, caprylic "morpholineethanesulfonic, diethylbarbituric, glycine, beta-alanine, 6-aminocaproic acid, optionally neutralized by the electrolyte counterion, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium acid to an approximate pH of the guide electrolyte, and the measured detector signal or the zone lengths of the components analyzed will identify or determine the content of the components in the analyzed sample.