JP2008157627A - Quantitative determination method for sulfonic acid type anionic surfactant in copper electrolyte or plating liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quantitative determination method of satisfactory reproducibility for a sulfonic acid type anionic surfactant in a copper electrolyte or a plating solution, capable of reducing an error. <P>SOLUTION: Ammonia is made to act on 25-250 ml of copper electrolyte or plating solution as a complexing agent to bring a treating solution into 8-13 of pH, a temperature of the solution is maintained at ≤30°C, preferably 10-30°C, in reaction, and a heavy metal ion contained in the copper electrolyte or plating solution is thereby changed into an amine complex to obtain the adjusted treating solution. The heavy metal ion contained in the copper electrolyte or plating solution is prevented by this manner from acting as disturbance when forming a methylene blue complex. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a method for analyzing a sulfonic acid type anionic surfactant used as an additive for surface modification in copper electrolytic purification and plating, and in particular, a sulfonic acid type anionic surfactant in a copper electrolytic solution or a plating solution. It relates to a method for quantitative determination.

  In the copper electrolytic refining method, an acidic copper sulfate solution is used as an electrolytic solution, for example, purified crude copper cast into a predetermined shape is used as an anode, and a copper plate having a thickness of about 1 mm obtained by electrolytic purification is used as a cathode. As the product is circulated, the anode and cathode are energized, and copper is electrodeposited on the cathode to obtain electrolytic copper as a product.

  At this time, if electrolytic purification is performed only with a sulfuric acid copper sulfate solution, electrolysis unevenness will occur or it will be difficult to obtain a smooth surface of electrolytic copper. Usually, a small amount of glue, thiourea, sulfonate anions Add organic additives such as surfactants. These organic additives have an appropriate concentration range, and if added beyond the appropriate concentration range, good surface electrolytic copper cannot be obtained as in the case of no addition. Therefore, the concentration control of the organic additive in the electrolytic solution is indispensable for obtaining electrolytic copper that is a good product. In order to appropriately perform such concentration management, it is necessary to be able to perform quantitative analysis of organic additives at the operation site.

  Some methods for quantifying organic additives have been established. For example, the quantification method described in Patent Document 1 relating to the present applicant concerning glue which is a collection of various similar compounds having different molecular weights is as follows.

An electrode reaction rate constant k _c (cm / sec) of a copper electrolytic refined electrolyte containing a certain amount of glue with a known average molecular weight different in average molecular weight Mw is obtained, and the different average molecular weight Mw corresponds to this. Using the relational expression k _c = A (log Mw) + B obtained from the relationship with the electrode reaction rate constant k _c (cm / sec), the average molecular weight Mw of the glue whose average molecular weight is unknown is estimated, and By substituting log Mw of an unknown average molecular weight into a = (log Mw) / C, based on the logarithm C of the average molecular weight of the two, the relative activity a of the unknown unknown molecular weight is determined.

  Patent Document 2 discloses a method in which a sample solution in which thiourea coexists is adjusted to sulfuric acid acid, and then palladium is added to form a thiourea-palladium complex, and thiourea is quantified by its turbidity. It is disclosed.

  However, for the sulfonic acid type anionic surfactant in copper electrolysis, it cannot be said that a quantitative method that can be used for bath management at the operation site is well established.

  In this regard, Patent Document 3 relating to the present applicant describes a method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte solution or a plating solution comprising the following steps.

1) A step of producing a treatment liquid by treating heavy metal ions contained in a copper electrolyte or plating solution with a complexing agent,
2) In order to derivatize the water-soluble sulfonic acid type anionic surfactant contained in the copper electrolyte or plating solution into a compound soluble in an organic solvent, an ion pair of the sulfonic acid type anionic surfactant is used. Adding a certain amount of methylene blue to an aqueous solution to produce an aqueous solution of methylene blue;
3) contacting the treatment liquid with the methylene blue aqueous solution to form an aqueous solution in which the methylene blue complex of the sulfonic acid type anionic surfactant is dissolved;
4) contacting the aqueous solution in which the methylene blue complex is dissolved with an organic solvent, and selectively extracting the methylene blue complex into the organic solvent to produce an extract;
5) measuring the absorbance of the extract,
6) A step of determining the amount of the sulfonic acid type anionic surfactant by inserting the measured absorbance into the correlation between the sulfonic acid type anionic surfactant and the absorbance.

  In the method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte or plating solution described in Patent Document 3, ammonia or ethylenediaminetetraacetic acid is used as the complexing agent, and the pH is adjusted to 8-12. Get. Then, the wavelength of the interfering components other than the methylene blue complex of the sulfonic acid type anionic surfactant is scanned in advance with an ultraviolet spectrophotometer, and the optimum quantitative wavelength that does not interfere with the measurement wavelength of the methylene blue complex of the sulfonic acid type anionic surfactant. And measure the absorbance with an ultraviolet spectrophotometer. This increases the accuracy of quantitative analysis of the sulfonic acid type anionic surfactant in the copper electrolyte.

However, the quantification method of the sulfonic acid type anionic surfactant in the copper electrolyte solution or plating solution described in Patent Document 3 has poor reproducibility and a large quantitative value in the process of practical application. It has become clear that errors can occur.
Japanese Patent Laid-Open No. 08-304338 JP 2001-147197 A JP 2002-055097 A

  An object of the present invention is to provide a method for quantifying a sulfonic acid type anionic surfactant in a copper electrolyte or plating solution with good reproducibility and little error.

  As a result of various studies, the present inventors have found that the amount of heat generated during the neutralization operation is large and the sample solution temperature becomes high, and the reason is unknown, but the production rate of the methylene blue complex varies. The reproducibility of the analysis results is reduced, and when the amount of the sample solution used for quantification is 10 ml, the absorbance of the obtained methylene blue complex is too low depending on the concentration of the sulfonic acid type anionic surfactant in the sample. In such a case, it has been found that a large error occurs in the quantitative value, and the present invention has been completed.

  The method for quantifying a sulfonic acid type anionic surfactant in a copper electrolytic solution or a plating solution of the present invention is a method of inducing a sulfonic acid type anionic surfactant contained in a copper electrolytic solution or a plating solution into a methylene blue complex, After extracting with a solvent, this is a method of selectively quantifying by measuring absorbance, and ammonia is allowed to act as a complexing agent on 25 to 250 ml of copper electrolyte or plating solution to adjust the pH of the treatment solution to 8 to 13. And it has the process of adjusting the heavy metal ion contained in a copper electrolyte solution or a plating solution to an ammine complex by maintaining the liquid temperature at the time of reaction at 30 degrees C or less, Preferably it is 10-30 degreeC. . This prevents heavy metal ions contained in the copper electrolyte or plating solution from interfering with the induction of the sulfonic acid type anionic surfactant into the methylene blue complex.

  Alternatively, it consists of the following steps, and the sulfonic acid type anionic surfactant contained in the copper electrolyte or plating solution is derived into a methylene blue complex, extracted with an organic solvent, and then selectively quantified by measuring the absorbance. To do.

1) A methylene blue purification step for obtaining an aqueous methylene blue solution containing no impurities.

2) 25 to 250 ml of copper electrolyte or plating solution is allowed to act with ammonia as a complexing agent to adjust the pH of the treatment solution to 8 to 13, and the reaction temperature is 30 ° C. or less, preferably 10 to 30 The process liquid adjustment process which adjusts the heavy metal ion contained in a copper electrolyte solution or a plating solution to an ammine complex, and obtains a process liquid by maintaining at ° C.

3) Formation of a methylene blue complex that forms a methylene blue complex of a sulfonic acid type anionic surfactant by mixing the methylene blue aqueous solution obtained from the methylene blue purification step and the treatment solution obtained in the treatment solution adjustment step. Process.

4) A methylene blue complex extraction step for obtaining an organic phase containing a methylene blue complex by bringing the resulting solution containing the methylene blue complex into contact with an organic solvent.

5) An organic phase purification step for purifying the organic phase containing the methylene blue complex by bringing the methylene blue aqueous solution obtained in the methylene blue purification step into contact with the organic phase obtained in the methylene blue complex extraction step.

6) An absorbance measurement step in which the amount of the organic phase containing the methylene blue complex obtained in the organic phase purification step is constant and the absorbance of the organic phase is measured.

7) Calculation for determining the amount of the sulfonic acid type anionic surfactant by inserting the value obtained in the absorbance measurement step into the correlation between the sulfonic acid type anionic surfactant and the absorbance determined in advance. Process.

  According to the present invention, it is a solution (for example, an electrolytic solution or a plating solution) containing a metal ion of about several to several tens g / l and containing a small amount of a sulfonic acid type anionic surfactant. Moreover, about 1 microgram / l sulfonic acid type | mold anionic surfactant can be selectively quantified from those solutions.

  In addition, the sulfonic acid type anionic surfactant in the copper electrolyte can be quantified with high sensitivity and high accuracy, which is an effective analysis method for bath management of the copper electrolytic bath.

  The present invention will be described with reference to the drawings. FIG. 1 is a flow sheet showing an embodiment of the present invention.

  The quantification method of the sulfonic acid type anionic surfactant in the copper electrolyte or plating solution of the present invention comprises the following steps, and the sulfonic acid type anionic surfactant contained in the copper electrolyte or plating solution After derivatization with a methylene blue complex and extraction using an organic solvent, quantitative determination is performed by measuring absorbance.

1) A methylene blue purification step for obtaining an aqueous methylene blue solution containing no impurities.

2) 25 to 250 ml of copper electrolyte or plating solution is allowed to act with ammonia as a complexing agent to adjust the pH of the treatment solution to 8 to 13, and the reaction temperature is 30 ° C. or less, preferably 10 to 30 The process liquid adjustment process which adjusts the heavy metal ion contained in a copper electrolyte solution or a plating solution to an ammine complex, and obtains a process liquid by maintaining at ° C.

3) Formation of a methylene blue complex that forms a methylene blue complex of a sulfonic acid type anionic surfactant by mixing the methylene blue aqueous solution obtained from the methylene blue purification step and the treatment solution obtained in the treatment solution adjustment step. Process.

4) A methylene blue complex extraction step for obtaining an organic phase containing a methylene blue complex by bringing the resulting solution containing the methylene blue complex into contact with an organic solvent.

5) An organic phase purification step for purifying the organic phase containing the methylene blue complex by bringing the methylene blue aqueous solution obtained in the methylene blue purification step into contact with the organic phase obtained in the methylene blue complex extraction step.

6) An absorbance measurement step in which the amount of the organic phase containing the methylene blue complex obtained in the organic phase purification step is constant and the absorbance of the obtained organic phase is measured.

7) Calculation for determining the amount of the sulfonic acid type anionic surfactant by inserting the value obtained in the absorbance measurement step into the correlation between the sulfonic acid type anionic surfactant and the absorbance determined in advance. Process.

  By using 25 to 250 ml of copper electrolyte or plating solution in the treatment liquid purification step, the concentration of methylene blue complex in the organic phase can be increased when adjusted to a certain amount in the absorbance measurement step. As a result, the absorbance of the organic phase rises to about 10 to 100 times that of the blank sample, lowering the lower limit of quantification, and improving the quantification accuracy.

  On the other hand, for example, the treatment amount of the copper electrolyte used for quantification of the sulfonic acid type anionic surfactant contained in the copper electrolyte or the plating solution is 10 ml as in the conventional method, and the copper When quantifying the sulfonic acid type anionic surfactant in the solution or plating solution, the absorbance of the resulting methylene blue complex is only about 2 to several times that of the blank sample, and the sulfonic acid type anionic surface activity When the concentration of the agent is low, the variation in the quantitative value becomes large, and the analysis accuracy that can manage the copper electrolytic bath may not be obtained.

  Moreover, ammonia is allowed to act as a complexing agent to adjust the pH of the treatment solution to 8 to 13, and the heavy metal group in the copper electrolyte or plating solution is made into a water-soluble ammine complex, thereby precipitating as a hydroxide. In addition, measurement errors are prevented from occurring due to adsorption or occlusion of the sulfonic acid type anionic surfactant or the generated methylene blue complex to the hydroxide.

  As a result, the sulfonic acid type anionic surfactant present in the treatment liquid becomes a methylene blue complex efficiently and without loss.

  Furthermore, the liquid temperature during the reaction is maintained at 30 ° C. or lower, preferably 10 to 30 ° C. As described above, the reason is not known, but when this range is exceeded, the methylene blue complex does not form quantitatively.

  In this regard, an ammine complex is formed without adjusting the temperature, and reacted with methylene blue in a state where the liquid temperature does not drop to room temperature, so that the sulfonic acid type anionic surface activity in the copper electrolyte or plating solution of the present invention When the reagent is quantified, a stable quantitative value can be obtained when the reaction temperature is 30 ° C. or lower. However, at a temperature exceeding 30 ° C., the reaction rate decreases and a negative error is given to the quantitative value. . Moreover, in order to make reaction temperature less than 10 degreeC, since cooling devices other than water cooling are needed, it is unpreferable.

  Below, it demonstrates for every process.

1) Methylene blue purification step In the figure, a methylene blue aqueous solution is obtained which is shown in two series of a separatory funnel 1 and a separatory funnel 2 and does not contain an organic solvent extract extracted into an organic solvent.

  In separatory funnel 1, 25 ml of pure water (organo-purified water), 5 ml of alkaline sodium borate as a buffering agent, and 5 ml of methylene blue were placed in a separatory funnel, mixed by immersion, then immersed in 5 ml of chloroform. I will. Thereafter, the separatory funnel is allowed to stand to separate the chloroform phase and the aqueous phase, and it is observed whether or not the chloroform phase is colored.

  If the chloroform phase is colored, add 5 ml of chloroform to the obtained aqueous phase, soak it, and leave the separatory funnel to separate the chloroform phase from the aqueous phase. Repeat until the aqueous phase after no longer colored is transferred to the next step. Thereby, impurities in methylene blue can be repeatedly extracted and removed.

  Separating funnel 2 is the same as separating funnel 1 except that the amount of pure water (organo-purified water) is 50 ml.

  Thus, an aqueous methylene blue solution containing no organic solvent extract is obtained.

2) Process liquid adjustment process 25-250 ml of copper electrolyte solution or plating solution is extract | collected, for example to a beaker, and ammonia is dripped as a complexing agent while stirring, and pH of a process liquid is 8-13. In that case, the liquid temperature at the time of reaction is maintained at 30 degrees C or less, Preferably it is 10-30 degreeC.

  If the pH is less than 8, even if ammonia is used, a large amount of hydroxide precipitates. Therefore, the pH is increased to 8 or more to completely change the hydroxide precipitate into a water-soluble ammine complex. Thereby, heavy metals, such as copper, nickel, or cobalt, contained in the copper electrolyte or plating solution are stably dissolved as ammine complex ions.

  The same effect can be obtained by blowing ammonia gas instead of dropping ammonia.

  If there is a precipitate in the treatment solution thus obtained, it is removed by filtration.

3) Methylene blue complex formation process.

  A sulfonic acid type anionic surfactant in the treatment liquid is obtained by mixing the methylene blue aqueous solution, which is obtained in the separatory funnel 1 and does not contain the organic solvent extract, and the treatment liquid obtained in the treatment liquid generation step. Methylene blue complex is formed.

4) Methylene blue complex extraction step Add 5 ml of chloroform into the separatory funnel 1, soak, and then leave to stand to separate the aqueous phase and the chloroform phase, discard the aqueous phase, Move to the process.

5) Organic phase purification step Chloroform phase obtained in the methylene blue complex extraction step, methylene blue aqueous solution obtained in the separatory funnel 2 and containing no organic solvent extract, and 35 parts of water for 1 part of sulfuric acid. The diluted sulfuric acid solution obtained in addition is mixed, immersed in a separatory funnel, and then allowed to stand to obtain a chloroform phase. As described above, it is possible to obtain a purified chloroform phase by washing out impurities incorporated in the chloroform phase in the methylene blue complex extraction step into the aqueous phase.

6) Absorbance measurement step The amount of the chloroform phase containing the methylene blue complex obtained in the organic phase purification step is kept constant, and the absorbance of the obtained organic phase is measured.

  The measurement is performed by monitoring the wavelength scan measurement of the ultraviolet spectrophotometer. In the wavelength scan measurement of the ultraviolet spectrophotometer, it is possible to select a wavelength that is not affected by the disturbing component. As the wavelength to be selected, an optimum quantitative wavelength of the methylene blue complex is selected so that light absorption by the methylene blue complex of the sulfonic acid type anionic surfactant is not disturbed by components other than the methylene blue complex. Specifically, wavelength selection is performed by performing wavelength scan measurement and confirming the maximum absorption wavelength. As described above, the accuracy of the quantitative value can be increased.

7) Calculation step The amount of the sulfonic acid type anionic surfactant is determined by inserting the value obtained in the absorbance measurement step into the correlation between the sulfonic acid type anionic surfactant and the absorbance determined in advance. . From the amount of the obtained sulfonic acid type anionic surfactant,
The quantitative value of the sulfonic acid type anionic surfactant in the sample solution is determined.

  Below, the verification result about the influence which the glue contained in a copper electrolyte solution gives to a quantitative value, the effect of the liquid temperature at the time of processing liquid preparation, and the influence of a sample solution amount is demonstrated.

1) Effect of glue contained in copper electrolyte on quantitative value As mentioned above, glue is added to the actual copper electrolyte, and the liquidity of the copper electrolyte is sulfuric and heated. It is also conceivable that the decomposition products generated by the decomposition of glue with sulfuric acid as a catalyst form a methylene blue complex as in the case of the sulfonic acid type anionic surfactant. Therefore, the influence of glue on the method of the present invention will be discussed below.

  As shown in Table 1, copper electrolyte without adding glue (blank), copper electrolyte with 10 times the usual amount of glue, copper electrolyte with 100 times the usual amount of glue, and A copper electrolyte with a normal amount of glue added was obtained and held at 80 ° C. for 3 hours.

  About 100 ml of each, the light absorbency of wavelength 650nm was measured using the ultraviolet spectrophotometer (the Hitachi, Ltd. make, U-2000). The measurement results are shown in Table 1.

  According to Table 1, when 100 times the normal amount of glue is added, the effect of the glue increases, but when 10 times the usual amount of glue is added, the measured absorbance is the same as that of the blank. The absorbance is of the order and does not affect the quantitative analysis of the sulfonic acid type anionic surfactant.

2) Effect of liquid temperature at the time of processing liquid preparation Using the same copper electrolyte used in actual operation, the reaction temperature of the processing liquid generation step is 10 ° C, 20 ° C, 30 ° C, 40 ° C, and 60 ° C. Except for the above, the sulfonic acid type anionic surfactant was quantitatively analyzed according to the flow sheet shown in FIG. The measurement results are shown in Table 2.

  From Table 2, it can be seen that when the reaction temperature exceeds 30 ° C., the quantitative value decreases. Although the reason is not clear, it is presumed that the formation amount of the methylene blue complex of the sulfonic acid type anionic surfactant decreases due to the decomposition of the sulfonic acid type anionic surfactant.

3) Effect of sample solution amount Using the same real copper electrolyte, the sample solution amount used for the treatment solution generation step was 0 ml, 10 ml, 25 ml, 100 ml, 250 ml, 300 ml, or 500 ml, and the reaction temperature was 20 ° C. Except for the above, the sulfonic acid type anionic surfactant was quantitatively analyzed according to the flow sheet shown in FIG. Table 3 shows the measurement results.

  From Table 3, it is understood that an accurate quantitative value can be obtained by setting the amount of the sample solution to be used for the treatment liquid generation step to be in the range of 25 to 250 ml. When the amount of the sample solution is less than 25 ml, it is presumed that it is greatly affected by the absorbance value of the blank.

(Examples 1 to 3, Comparative Examples 1 and 2)
25 ml of real copper electrolyte was used as a sample solution, and the pH in the treatment liquid generation step was 3.0 (Comparative Example 1), 6.2 (Comparative Example 2), 8.0 (Example 1), 11. 1 (Example 2) or 13.0 (Example 3), except that the reaction temperature was maintained at 20 ° C., the quantitative analysis of the sulfonic acid anionic surfactant was performed according to the flow sheet shown in FIG. Went. An ultraviolet spectrophotometer (manufactured by Hitachi, Ltd., U-2000) was used for measuring the absorbance. Table 4 shows the measurement results.

  From Table 4, when the pH is less than 8.0, an accurate quantitative value is not measured. The complex of sulfonic acid anionic surfactant with other compounds and metals is not sufficiently decomposed, and the adsorption and occlusion of the sulfonic acid anionic surfactant to the starch generated by neutralization causes It is presumed that the formation of methylene blue complex was insufficient.

(Comparative Example 3)
Except that 10 ml of actual copper electrolyte was used as a sample solution, the pH in the treatment liquid generation step was set to 12.5, and the reaction temperature was maintained at 20 ° C., the flow sheet shown in FIG. Quantitative analysis of sulfonic acid anionic surfactant was conducted. Table 4 shows the measurement results.

(Comparative Examples 4-6)
10 ml of actual copper electrolyte was used as a sample solution, and the pH in the treatment liquid generation step was set to 12.5 (Comparative Example 4), 12.2 (Comparative Example 5), or 12.3 (Comparative Example 4). In addition, except that the reaction temperature was not controlled, the sulfonic acid anionic surfactant was quantitatively analyzed according to the flow sheet shown in FIG. Table 4 shows the measurement results.

  As shown in Examples 1 to 3 and Comparative Examples 1 to 6, the method of the present invention can stably obtain a quantitative value of the sulfonic acid type anionic surfactant. The quantitative accuracy is considered to be high because derivatization of the sulfonic acid type anionic surfactant to the methylene blue complex was produced with a stable reaction rate.

  The amount of copper electrolyte used is preferably 25 to 250 ml, and the quantitative value of the sulfonic acid type anionic surfactant in the copper electrolyte is stable. It turns out that it is a level which can be implemented.

It is the flow sheet which showed one Example of this invention.

Claims (2)

  The sulfonic acid type anionic surfactant contained in the copper electrolyte or plating solution is derived into a methylene blue complex, extracted with an organic solvent, and then selectively quantified by absorbance measurement. This is a method for quantifying a sulfonic acid type anionic surfactant, wherein ammonia is allowed to act as a complexing agent on 25 to 250 ml of a copper electrolyte or plating solution to adjust the pH of the treatment solution to 8 to 13, and during the reaction. Sulfonic acid type anions in a copper electrolyte or plating solution, characterized by having a step of adjusting heavy metal ions contained in the copper electrolyte or plating solution to an ammine complex by maintaining the liquid temperature at 30 ° C. or lower Surfactant quantification method. Copper that consists of the following steps, derivatizes the sulfonic acid-type anionic surfactant contained in the copper electrolyte or plating solution into a methylene blue complex, extracts it with an organic solvent, and selectively quantifies it by absorbance measurement Method for quantifying sulfonic acid type anionic surfactant in electrolyte or plating solution:
1) A methylene blue purification step for obtaining a methylene blue aqueous solution free of impurities,
2) By causing ammonia to act as a complexing agent on 25 to 250 ml of copper electrolyte or plating solution to adjust the pH of the treatment solution to 8 to 13, and maintaining the solution temperature at 30 ° C. or lower during the reaction, A treatment solution adjustment step of obtaining a treatment solution by adjusting heavy metal ions contained in the copper electrolyte or plating solution to an ammine complex;
3) Formation of a methylene blue complex that forms a methylene blue complex of a sulfonic acid type anionic surfactant by mixing the methylene blue aqueous solution obtained from the methylene blue purification step and the treatment solution obtained in the treatment solution adjustment step. Process,
4) A methylene blue complex extraction step for obtaining an organic phase containing a methylene blue complex by bringing the resulting solution containing the methylene blue complex into contact with an organic solvent.
5) An organic phase purification step for purifying an organic phase containing a methylene blue complex by bringing the methylene blue aqueous solution obtained in the methylene blue purification step into contact with the organic phase obtained in the methylene blue complex extraction step,
6) An absorbance measurement step in which the amount of the organic phase containing the methylene blue complex obtained in the organic phase purification step is constant, and the absorbance of the organic phase is measured.
7) Calculation for determining the amount of the sulfonic acid type anionic surfactant by inserting the value obtained in the absorbance measurement step into the correlation between the sulfonic acid type anionic surfactant and the absorbance determined in advance. Process.

Images