JP5434188B2 - Regeneration method of electroless plating solution - Google Patents

Description

  The present invention contains hypophosphite as a reducing agent, and phosphorous acid is effectively produced from electroless plating solution such as electroless nickel plating solution in which phosphorous acid is generated and accumulated by oxidation of hypophosphite. The present invention relates to a method for regenerating an electroless plating solution that can be efficiently removed by removing the electroless plating solution.

In an electroless plating solution such as an electroless nickel plating solution containing hypophosphite as a reducing agent, hypophosphite is oxidized to phosphorous acid as the plating proceeds, and phosphorous acid is accumulated. In this case, when phosphorous acid accumulates about 0.8 to 1.5 mol / L or more, the deposition rate of the electroless plating solution decreases, or the physical properties of the obtained electroless plating film decrease. It becomes a state that cannot be used. The standard here is usually 5-7 turns. One turn refers to the time when the amount of metal corresponding to the metal ion concentration in the initial plating solution is electrolessly deposited. That is, in the case of an electroless nickel plating solution, Ni ²⁺ in the original plating solution is usually 6 g / L, for example, but Ni ²⁺ decreases with the progress of plating. For this reason, the plating is continuously performed while maintaining the initial concentration of 6 g / L by replenishment of Ni ²⁺ together with replenishment of hypophosphite. The time when an electroless nickel film corresponding to 6 g / L is obtained is defined as one turn.

  As described above, the electroless plating solution is one in which the plating solution is aged by the accumulation of phosphorous acid, but the phosphorous acid is separated and removed, or a metal such as nickel is recovered from the electroless aging plating solution. Various methods for regenerating and treating the electroless plating solution have been proposed.

For example, in Japanese Patent No. 3420570 (Patent Document 1),
“In a method of regenerating an electroless metal deposition bath containing hypophosphite ions as a reducing agent by electrodialysis, a first electrodialysis unit (E1) and a second electrodialysis having a cathode (Ka) and an anode (An), respectively. In the unit (E2), electrodialysis is performed, and in both the first and second electrodialysis units (E1, E2), dilution chambers and concentration chambers are alternately arranged, and the first electrodialysis unit The dilution chamber (Dila, Di1b,..., Di1x) has a concentration chamber (Ko1a, Ko1b,..., Ko1x) and a monoselective cation exchange membrane (KS) on the cathode side. Partitioned by an anion exchange membrane (A), the concentration chamber (Ko2a, Ko2b,..., Ko2x) of the second electrodialysis unit is the dilution chamber (Di2a, Di). b,..., Di2x) and an anion exchange membrane (A) on the cathode side, and a monoselective anion exchange membrane (AS) on the anode side. Electroless, characterized by being sent simultaneously through dilution chambers (Dila, Di1b,..., Di1x; Di2a, Di2b,..., Di2x) of both the first and second electrodialysis units (E1; E2) A method for regenerating a metal deposition bath by electrodialysis. "
Although There has been disclosed, the method, since the plating solution electrolytic dialysis containing metal ions of Ni ^2+, etc., metal ions Ni ²⁺ and the like to an ion exchange membrane electrodeposited, ion-exchange membrane There is a problem of reducing the lifetime of the.

In the above method, for the recovery of metal ions Ni ²⁺ and the like from the concentrated fluid after the electrolytic dialysis, in Kohyo 2005-536644 (Patent Document 2),
“A method for regenerating an electroless metal plating bath, wherein the metal plating bath is introduced into the respective dilution compartments (Di1y, Di2y) of the electrodialysis structure (E1, E2) and removed from the metal plating bath. Concentrated fluids that act to absorb the disturbing substances to be introduced are introduced into the respective concentrating compartments (Ko1y, Ko2y) of the electrodialysis structure (E1, E2), the concentrating compartments being separated by ion exchange membranes from the dilution compartment (Di1y). , Di2y)
The method is further characterized in that the concentrated fluid is further passed through a main cation exchanger (Ix) and recycled back into the concentration compartment (Ko1y, Ko2y). "
There are disclosed, as with Patent Document 1, since the plating solution electrolytic dialysis containing metal ions Ni ²⁺ and the like, there is the same problem.

Furthermore, all of the above methods separate phosphorous acid from hypophosphorous acid, but phosphorous acid is mainly a monovalent ion of H ₂ PO ₃ ⁻ when the pH of the plating solution is lower than 8.5. In the form of a divalent ion of HPO ₃ ²⁻ with a pH of 8.5 or higher. Therefore, when performing electrolytic dialysis in the method of Patent Documents 1 and 2, hypophosphite ion H ₂ PO ₂ present in the form of a monovalent ion ^- and for separating, phosphite is divalent ions it is necessary to be present in the form, Accordingly, there is need electrolytic dialysis to be plating solution of pH 8.5 or higher, which is higher the better the higher, too high a pH of the plating solution In addition, metal ions such as Ni ²⁺ become hydroxides and are suspended in the plating solution, and when Na ⁺ migrates from the plating solution to be treated by the above method, the plating solution becomes acidic, Phosphoric acid may become monovalent.

JP 2007-254805 (Patent Document 3)
“In an electroless nickel plating method in which an object to be plated is immersed in an electroless nickel plating solution and a nickel plating film is applied to the surface of the object to be plated, the electroless nickel plating solution in which phosphite ions are accumulated is nickel. The electroless nickel plating solution extracted from the plating tank is contacted with an amine-containing organic solvent and a hypophosphorous acid-containing aqueous solution to form a hypophosphite amine complex in the organic phase and phase-separated. After contacting the organic phase containing the resulting hypophosphite amine complex and extracting the phosphite ion as an phosphite amine complex into the organic phase and transferring the hypophosphite ion into the aqueous phase, An electroless nickel plating method, wherein the aqueous phase obtained by phase separation is returned to the nickel plating tank. "
However, since a large amount of extraction solvent is used, there is a problem of cost and the processing efficiency is still not sufficient.

In JP 2004-307983 A (Patent Document 4),
“A method for recovering nickel from a nickel-containing aqueous solution, wherein an organic solvent containing a β-hydroxyoxime-based extractant and an acidic organic phosphorus compound is brought into contact with a nickel-containing aqueous solution to extract nickel into the organic solvent phase. . "
Is disclosed, but the separation treatment of hypophosphorous acid and phosphorous acid is not shown.

Furthermore, JP 2005-42183 A (Patent Document 5) describes:
“After adjusting the pH of the electroless plating solution waste solution containing hypophosphite as a reducing agent, it is brought into contact with an organic solvent containing a long-chain alkylamine-based extractant, and then separated into an organic phase and an aqueous phase. A method for treating an electroless plating waste solution, characterized by repeating the step of adjusting the pH value of an aqueous phase comprising the waste solution of the electroless plating solution and contacting with an organic solvent containing a long-chain alkylamine-based extractant.
Is disclosed in Japanese Patent Application Laid-Open No. 2007-326023 (Patent Document 6).
“Adjusting the electroless nickel plating bath waste liquid and / or washing water so that the nickel ion concentration is 1000 mg / L or less, and then passing it through the chelate resin under the conditions of pH 1 to 6 to adsorb the nickel ions. A feature of the electroless nickel plating bath waste liquid and / or washing water treatment method ”
However, there are problems in terms of cost and processing efficiency.

Japanese Patent No. 3420570 JP 2005-536644 A JP 2007-254805 A JP 2004-307983 A JP 2005-42183 A JP 2007-326023 A

The present invention has been made in view of the above circumstances, and can efficiently recover metal ions such as nickel, hypophosphite ions, and monovalent complexing agent ions from an electroless plating solution in which phosphorous acid is accumulated. In addition, phosphorous acid and impurity metal ions present in the plating solution can be efficiently separated, and the electroless plating solution can be regenerated efficiently and inexpensively over a long period of time. An object of the present invention is to provide a method for regenerating a plating solution.

As a result of intensive studies in order to achieve the above object, the present inventors, for example, in the case of an electroless nickel plating solution, Ni ²⁺ as the main metal ion, hypophosphite ion as the reducing agent, No complex containing a complexing agent that complexes metal ions, for example, a monovalent complexing agent anion such as acetic acid or lactic acid, or a divalent or trivalent complexing agent anion such as citric acid or succinic acid. When plating is performed using an electroless plating solution such as an electrolytic nickel plating solution, phosphorous acid accumulates as the plating progresses, and this electroless plating solution with accumulated phosphorous acid is subjected to cation exchange. Treatment with resin adsorbs main metal ions and impurity metal ions in the plating solution, separates the demetalized plating solution containing hypophosphite ions, phosphite ions, etc., and adsorbs them to the cation exchange resin Elution of metal ions with the appropriate eluent After, while collecting the separated and removed the impurity metal ions from the eluent main metal ion (Ni ^2+, etc.), applying to the electrolytic dialysis treatment the demetallization plating solution, in this case, the ion-exchange membrane as with the use of a mono-selective ion-exchange membrane monovalent anion and can be separated efficiently and divalent anions, moreover electrolytic dialysis treatment is plating solution to be subjected, the main metal ions Ni ^2+, etc. because they are removed in advance, this is because the primary metal ion to a plating solution to apply even without addition electrolytic dialysis things like electrodeposited on the ion-exchange membrane is not contained, the pH well above 8.5 or higher higher Guaranteed it even metal hydroxide produced be increased, long period stable efficient electrolytic dialysis treatment can be performed, and knowledge that it is possible to inexpensive processes in terms of cost, the present invention To make It was.

Accordingly, the present invention provides the following method for regenerating an electroless plating solution.
Claim 1:
An electroless plating solution containing main metal ions, hypophosphite ions, complexing agents of the above main metal ions, and phosphite ions is passed through the cation exchange resin, and the cation exchange resin is passed through the plating solution. A main metal ion and an impurity metal ion contained in the cation exchange resin, and a process for passing the demetalized plating solution containing hypophosphite ion and phosphite ion separated from the metal ion; the adsorbed metal ions eluted in the eluent, the main metal ions to remove impurity metal ions from the metal ion of the eluent during the separation, a process of recovering, the demetallization plating solution electrolytic dialysis treatment to The monovalent anion solution containing hypophosphite ions and monovalent complexing agent ions is separated from the polyvalent anion solution containing phosphorous acid and bivalent or higher complexing agent ions. And a method of reproducing an electroless plating solution; and a process of discarding the polyanion solution.
Claim 2:
The regeneration method according to claim 1, wherein the treatment for separating the impurity metal ions from the main metal ions is performed by an organic solvent extraction method.
Claim 3:
The regeneration method according to claim 1 or 2, wherein the main metal ions from which the impurity metal ions have been separated and removed are subjected to an organic solvent extraction treatment to concentrate the main metal ions.
Claim 4:
Electrolytic dialysis treatment, selectively transmits hypophosphite ions and monovalent complexing agent ions de metal plating solution, a mono-selective anion-exchange membrane which does not transmit a divalent or more anions, H ⁺ selectively using the electrolytic dialysis cell equipped with a mono-selective cation-exchange membrane that transmits, demetallization plating solution to be treated between the mono selective anion exchange membrane and mono selective cation exchange membrane the method of regeneration according to any one of claims 1 to 3 is supplied to electrolytic dialysis process the.
Claim 5:
The regeneration method according to any one of claims 1 to 4, wherein the electroless plating solution is an electroless nickel plating solution.
Claim 6:
The regeneration method according to any one of claims 1 to 5, wherein the electroless plating solution to be treated is an electroless plating solution to be disposed of by increasing accumulation of phosphorous acid.
Claim 7:
The electroless plating solution to be treated is an electroless plating solution that is in use. The main portion of the metal ions, hypophosphite ions, and 1 recovered by extracting a part or all of the plating solution from the plating solution. The regeneration method according to any one of claims 1 to 5, wherein a complexing agent ion having a valence is supplied and circulated to the plating solution.

  According to the present invention, metal ions such as nickel, hypophosphite ions and monovalent complexing agent ions can be efficiently recovered, and impurity metal ions present in phosphorous acid and plating solution can be efficiently separated. Thus, the efficient electroless plating solution regeneration process can be carried out at low cost over a long period of time.

It is a schematic explanatory drawing of the apparatus used for the reproduction | regenerating method of the electroless-plating liquid of this invention. It is a schematic illustration of electrolytic dialyzer used in Examples.

The electroless plating solution to which the regeneration method of the present invention is applied can be any electroless plating solution using a hypophosphite such as sodium hypophosphite as a reducing agent. Electroless nickel plating solution such as electroless nickel plating solution, electroless cobalt plating solution, electroless iron plating solution, electroless Ni-Co, Ni-Fe, Ni-Fe-W, Ni-Fe-Mo plating solution Liquid, electroless gold plating solution, and the like, and in particular, electroless nickel plating solution and electroless nickel alloy plating solution are preferably used.

  In this case, in an electroless plating solution using hypophosphite as a reducing agent, hypophosphorous acid is oxidized and phosphorous acid is generated and accumulated with the progress of plating, and phosphorous acid is 0.8 to 1. If it is about 5 mol / L or more, the plating rate, plating film, etc. may be adversely affected, so this may be discarded, and the present invention regenerates the electroless aging plating solution to be discarded. Can be used for processing. Alternatively, before the phosphorous acid accumulates as described above, a part of the plating solution is taken out, and this is regenerated and returned to the original plating solution again. The reproduction method can be adopted.

Here, as a typical composition of the plating solution to be regenerated, the metal ions are 5 to 7 g / L, the complexing agent is 10 to 50 g / L, and the hypophosphite is 15 to 35 g / L. Examples thereof include a plating solution in which phosphorous acid is accumulated in an amount of 0.8 to 1.5 mol / L.
The pH of the plating solution may be acidic or alkaline.

  Examples of complexing agents include alkali metal salts and ammonium salts of monovalent anions, alkali metal salts and ammonium salts of divalent and / or trivalent anions, such as acetic acid, malic acid, succinic acid, citric acid, and tartaric acid. And alkali metal salts such as lactic acid and malonic acid, and ammonium salts. These may be used alone or in combination of two or more. In addition, lead salts, bismuth salts, and the like can be added as stabilizers. Furthermore, in many cases, the plating solution to be treated contains metal impurities such as iron, zinc, and copper derived from and mixed with the object to be plated and components used.

Cation Exchange Resin Treatment In the present invention, the electroless plating solution to be regenerated is first treated with a cation exchange resin. FIG. 1 shows this, and pumps an electroless plating solution 2 contained in an electroless plating tank 1 such as an electroless plating tank or an electroless plating storage tank attached to the plating tank in communication with the plating tank. 3 is passed through the cation exchange resin tower 4, the main metal ions in the electroless plating solution 2 (for example, Ni ^{2+ in} the case of nickel plating) and the Fe ³⁺ mixed in the plating solution 2. , Zn ²⁺ , Cu ^{2+ and} other impurity metal ions (hereinafter collectively referred to simply as metal ions) are adsorbed on the cation exchange resin. As a result, the metal removal plating solution from which the metal ions have been adsorbed and separated passes through the cation exchange resin tower 4 and is introduced into the metal removal plating solution storage tank 5.

  In this case, as the cation exchange resin, a chelate resin type cation exchange resin or the like is used, and those having terminal ions of H type are particularly preferable.

  As a treatment condition with the cation exchange resin, a known method is adopted, but it is preferable from the viewpoint of treatment efficiency that the pH of the plating solution to be passed is adjusted to about 3 to 6. Further, the liquid passing speed is SV = 0.5 to 2, and SV = 1 is particularly preferable. The processing temperature may be the atmospheric temperature.

Elution treatment After the treatment with the cation exchange resin as described above, the metal ions adsorbed on the cation exchange resin are desorbed and eluted using the eluent. A strong acid is preferable as the eluent, and hydrochloric acid, nitric acid, etc. can be used. From the point that the recovered metal is reused as the above plating solution, sulfuric acid is used as the eluent because the main metal ion is usually used as a sulfate. As shown in FIG. 1, the eluent is introduced into the cation exchange resin tower 4 from the eluent tank 6 by the pump 7, desorbed and eluted, and the elution that has passed through the tower 4 is used. The liquid 8 is introduced into the impurity metal separation tank 9.

In addition, as a elution process condition, a well-known method can be employ | adopted, for example, SV = 0.5-2 can be set as the flow rate of an eluent. The treatment temperature can be the ambient temperature.
In this case, depending on the Ni concentration in the aging plating solution, chelating resin flow conditions (flow rate, chelate resin amount, flow rate) and elution conditions (sulfuric acid concentration, flow rate, flow rate) The contained Ni concentration (other metal impurities) can be adjusted.

Impurity metal ion removal treatment The eluent after desorption of the metal ions adsorbed on the cation exchange resin contains main metal ions and impurity metal ions, and the eluent 8 is transferred to the separation tank 10. Impurity metal ions are separated and removed from the eluent.

As a separation / removal method, for example, if the metal ions contained in the eluent are Ni ²⁺ and Fe ³⁺ , the pH of the eluent is adjusted to 5 to 6 to remove Fe ³⁺ by water. It can be separated by precipitation as iron oxide, but if Zn ²⁺ or Cu ²⁺ is mixed, it is difficult to separate from Ni ^{2+ by the} hydroxide precipitation separation method. It is preferable to extract impurity metal ions and separate them from Ni ²⁺ .

Here, as the extraction liquid to be used, an extraction organic solvent containing an acidic organic phosphorus compound can be used. In this case, when the pH of the liquid to be treated is 3 to 4.5, in this organic solvent, Fe ³⁺ , Zn ²⁺ , Cu ^{2+ and the} like are selectively extracted, and Ni ²⁺ is not extracted. The pH of the eluent is adjusted to 3 to 4.5, and extraction processing is performed with the organic solvent.

  Specific examples of the acidic organic phosphorus compound include bis (2-ethylhexyl) phosphoric acid, 2-ethylhexylphosphoric acid, mono-2-ethylhexyl ester, bis (2,4,4-trimethylpentyl) phosphinic acid, and the like. It is done. Organic solvents include aromatic hydrocarbons such as kerosene, xylene, benzene, toluene and cyclohexane, aliphatic hydrocarbons such as hexane, heptane and normal paraffin, and naphthenic carbons such as 1-naphthenoic acid and 2-naphthenoic acid. Hydrogen can be used.

  As the extraction method, a known method can be adopted, and a method in which 1 to 3 times the volume of the organic solvent is used for the eluent and shaken sufficiently can be adopted.

By performing the extraction treatment in this way, the impurity metal ions in the eluent are transferred to the organic phase of the extract (the organic solvent), and the main metal ions such as Ni ²⁺ are the eluent (aqueous phase). etc. bets to be separated Mari, the main metal ions and impurity metal ions.
The extraction liquid is not limited to the above extraction solvent, and any extraction liquid can be used as long as it can separate main metal ions and impurity metal ions.

  The organic phase separated from the aqueous phase is introduced into the back extraction tank 11, where the impurity metal ions in the organic phase are mixed with a back extract comprising a sulfuric acid aqueous solution having a concentration of 5 to 15% by mass. By performing back extraction, the impurity metal ions can be transferred to the back-extracted solution of the aqueous phase and then subjected to a neutralization treatment, and then the impurity metal ions can be separated and disposed of by disposal. In addition, a well-known method and conditions can be employ | adopted also as the said back extraction processing method.

On the other hand, since the main metal ions such as Ni ²⁺ are separated in the aqueous phase obtained by the above extraction treatment, this is recovered, pH is adjusted, the concentration is adjusted, and this is electrolessly plated. For example, it can be directly supplied to the plating tank, supplied to the main metal ion replenisher tank, used for replenishment, or used to prepare a new plating solution.
In this case, as shown in FIG. 1, the concentration of main metal ions such as Ni ²⁺ in the aqueous phase can be adjusted by introducing the aqueous phase into the concentration adjusting tank 12.

In this impurity metal ion removal step (extraction method), metal impurities are removed to increase the purity of the Ni sulfate solution. If the purity is desired to be increased, the impurity metal ion removal step can be repeated. Therefore, the Ni ²⁺ concentration in the Ni sulfate solution remains the Ni ²⁺ ion concentration in the eluent. When the obtained Ni sulfate is used as a building bath liquid, a necessary amount of Ni sulfate solution can be put in a plating tank and used, and when used as a replenisher, Ni ²⁺ is 50 g / L or more. The elution condition may be adjusted (eluent concentration and amount, etc.) so that the Ni sulfate solution is finally produced, and then diluted to a predetermined replenisher concentration (for example, Ni ²⁺ 50 g / L). it can.
In addition, when heavy metals such as Pb are contained as a stabilizer, they are slightly removed in the impurity metal ion removal step, so that separate analysis and replenishment is required for the bathing and replenishment.

Electrodialysis treatment other hand, through the cation-exchange resin column 4, metal ions are adsorbed separated, leaving metal plating solution 13 introduced into the demetallization plating solution storage tank 5 is then pH-adjusting agent from the pH adjusting agent reservoir 14 And the pH of the metal removal plating solution 13 is adjusted to 8.5 or higher.

That is, in the metal removal plating solution, hypophosphite ions H ₂ PO ₂ ⁻ , phosphite ions, sulfate ions, monovalent complexing agent ions, divalent and / or trivalent complexing agent ions. In addition, H ⁺ , Na ^{+ and the} like are included as cations. When the pH in the plating solution is lower than 8.5, phosphite ions are mainly monovalent anions of H ₂ PO ₃ ^−. It exists as a divalent anion of HPO ₃ ^2- at a pH of 8.5 or higher. The later-described electrolytic dialysis treatment, a monovalent anion while shifting in the liquid to be recovered by transmitting an ion exchange membrane, 1 of divalent or more anion does not transmit an ion exchange membrane monovalent anion selective ion Since it is necessary to use an exchange membrane, the phosphite ion to be removed and discarded must be present in the form of a divalent anion. Therefore, the demetallizing plating solution adjusts the pH to 8.5 or higher, preferably 9 or higher, more preferably 9 to 10, and the pH should be higher.
De metal plating solution that is pH treatment as described above, which the electrolytic dialysis treatment.

Here, in FIG. 1, 20 is electrolytic dialysis cell, 21 is an anode, 22 a cathode, respectively to the anode and the cathode side is disposed cation exchange membranes 23 and 24, form the anode chamber 21a and the cathode chamber 22a The anode chamber 21a and the cathode chamber 22a are provided with an anode 21 and a cathode 22, respectively.
Further, a monoselective anion exchange membrane 25 is disposed on the anode side, and a monoselective cation exchange membrane 26 is disposed on the cathode side, respectively, so that the central monoselective anion exchange membrane 25 and the monoselective cation are disposed. A demetalization plating solution supply chamber 27 is formed between the exchange membrane 26 and a monovalent anion chamber 28 is formed between the cation exchange membrane 23 on the anode side and the monoselective anion exchange membrane 25, and the cathode side. A monovalent cation chamber 29 is formed between the cation exchange membrane 24 and the monoselective cation exchange membrane 26.

  In this case, the monovalent anion chamber 28 and the monovalent cation chamber 29 are connected to each other by pipes 30a and 30b, and the liquid in the monovalent anion chamber 28 and the monovalent cation chamber 29 passes through the pipe 30a. While being discharged into the valence ion storage tank 31, the liquid in the storage tank 31 is supplied and circulated to the monovalent anion chamber 28 and the monovalent cation chamber 29 through the pipe 30b. The demetalization plating solution supply chamber 27 communicates with the divalent anion storage tank 32 so that the liquid in the demetalization plating solution supply chamber 27 is discharged to the divalent anion storage tank 32 and the solution in the storage tank 32 is removed. It is supplied to the metal plating solution supply chamber 27 and circulated.

In the configuration of above-described electrolytic dialysis cell 20, when performing electrolytic dialysis, demetallization plating solution 13 of the above pH adjusted demetallization plating solution storage tank 5 is supplied to said divalent anion tank 32, introduced in de metal plating liquid supply chamber 27 of the electrolytic dialysis cell 20 from here. In this case, the metal removal plating solution 13 may be directly introduced into the metal removal plating solution supply chamber 27 without going through the divalent anion storage tank 32. An electrically conductive liquid such as an aqueous sulfuric acid solution having a concentration of 1 to 20% by mass is supplied into the anode chamber 21a and the cathode chamber 22a, and hypovalent phosphite is added to the monovalent anion chamber 28 and the monovalent cation chamber 29 in advance. Conductive liquid such as sodium 0.1-5 g / L aqueous solution is supplied.

As the cation exchange membranes 23 and 24, Astom Neoceptor CMX or the like can be used. As the monoselective anion exchange membrane 25, Astom Neoceptor ACS or the like is preferably used. Furthermore, as a monoselective cation exchange membrane 26, Astom Neoceptor CIMS may be used. In this case, the mono Selective cation exchange membrane 26, H ⁺ is to better transmission, Na ⁺ is obtained by suppressing the transmission, to less than 8.5 during processing the pH of the electrolytic dialysis demetallization plating solution to be It is possible to prevent the decrease.

By the treatment as described above, the hypophosphite ion H ₂ PO ₂ ⁻ and the monovalent complexing agent anion in the metal removal plating solution pass through the monoselective anion exchange membrane 25 into the monovalent anion chamber 28. However, phosphite ion HPO ₃ ^2- and divalent and trivalent complexing agent anions, and more than divalent anions such as SO ₄ ^2- do not pass through the monoselective anion exchange membrane 25, etc. door to de-metal plating solution supply chamber 27 round. Further, H ⁺ which is a cation in the metal removal plating solution moves into the monovalent cation chamber 29 through the monoselective cation exchange membrane 26. Alkali metal ions such as Na ⁺ can also be transferred into the monovalent cation chamber 29 through the monoselective cation exchange membrane 26, but the monoselective cation exchange membrane 26 has Na ⁺ , K ⁺ having a small pore size. By using a material that does not pass through or can be prevented from passing, it is possible to prevent Na ⁺ and K ⁺ from being transferred to the monovalent cation chamber 29, whereby the treatment in the metal removal plating solution supply chamber 27 can be suppressed. The pH of the liquid is lowered to less than 8.5, and the presence of phosphite ions as a monovalent anion of H ₂ PO ₃ ⁻ can be reliably suppressed.
According to the present invention, electrolytic dialysis treatment performed plating solution are pre-main metal ions Ni ²⁺ such removal does not include the main metal ion in the demetallization plating solution, mono during electrolytic dialysis There is no possibility that a main metal such as Ni is electrodeposited on the selective cation film 26, and the dialysis treatment can be performed stably for a long period of time.

Obtained by the above electrolytic dialysis treatment, the monovalent ion reservoir treatment solution which is stored in 31, because it contains hypophosphite ions and monovalent complexing agent ions, adjusted as appropriate pH and concentration It can be supplied to an electroless plating solution, or used as a hypophosphite replenisher, and further used for preparing a new plating solution.

  The concentration of the recovered anion (hypophosphorous acid, monovalent complexing agent) increases with repeated dialysis. Moreover, in order to adjust the balance between hypophosphorous acid and the monovalent complexing agent, it is preferable to perform analysis and supply of deficiency. When used as a replenisher, the concentration of hypophosphorous acid is preferably 100 to 600 g / L. It is.

On the other hand, the liquid stored in the divalent anion storage tank 32 contains a polyvalent anion such as phosphite ion, divalent complexing agent ion, and SO ₄ ²⁻ , and mainly has a high concentration of phosphorous acid. because, this is after the direct or appropriate processing, it can be discarded as produced waste like.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Example]
As electroless nickel aging plating solution was subjected to treatment with one of the following composition corresponding to the use of about 6 turns.
Composition Nickel sulfate (as Ni ²⁺ ) 5.5g / L
Sodium hypophosphite 30g / L
Phosphorous acid 100g / L
Acetic acid 15g / L
Succinic acid 15g / L
Fe ³⁺ 100ppm
Zn ²⁺ 50ppm
Cu ²⁺ 10ppm
pH 4.4

As demetallation cation exchange resin, using a Mitsubishi Chemical Corporation chelating resin, and the plating solution having the above composition was passed through the cation exchange resin.
(Liquid flow conditions)
Cation exchange resin amount: 200L
Amount of plating solution: 100 L (total Ni amount 550 g)
Flow rate: SV = 1
Processing temperature: 25 ° C
Processing time: 180 minutes

Elution treatment A sulfuric acid aqueous solution having a concentration of 10% by mass was used as an eluent, and metal ions adsorbed on the cation exchange resin were eluted and desorbed.
(Elution conditions)
Eluent volume: 27L
Flow rate: SV = 1
Processing temperature: 25 ° C
Processing time: 180 minutes

When the metal ion concentration in the obtained eluent was measured by atomic absorption photometry, the following results were obtained.
Ni ²⁺ 20g / L (total Ni content 540g)
Fe ³⁺ 370mg / L
Zn ²⁺ 185mg / L
Cu ²⁺ 37mg / L
pH <1

Impurity metal ion removal treatment Impurity metal ions (Fe ³⁺ , Zn ²⁺ , Cu ²⁺ ) in the eluent were removed by an extraction method.
In this case, LIX84-I (manufactured by Cognis) was used as the extract.
The eluent was adjusted to pH 3.5 with a caustic soda solution, and 100 mL of the eluent was added to 100 mL of the extract, and impurity metal ions were extracted under the following shaking conditions.

(Conditions for shaking)
Shaking width: 2cm
Shaking speed: 0.5 seconds / time Shaking temperature: 25 ° C
Shaking time: In the eluent was adjusted to 15 minutes pH 3.5, impurity metal ions by the shaking process proceeds to extraction with an organic solvent (organic phase), Ni ²⁺ waited etc. preparative into the aqueous phase. The organic phase and the aqueous phase were separated, and 100 mL of 10% by mass sulfuric acid was used as a back extract for 100 mL of the organic phase, and back extraction was performed under the following shaking conditions.

(Back extraction shaking condition)
Shaking width: 2cm
Shaking speed: 0.5 seconds / time Shaking temperature: 25 ° C
Shaking time: 15 minutes

By the reverse shaking treatment, impurity metal ions (Fe ³⁺ , Zn ²⁺ , Cu ²⁺ ) in the organic phase were transferred to the sulfuric acid solution. This was adjusted to pH 7.0 (neutralization treatment), impurity metal ions were precipitated and separated, and the solution was drained.
On the other hand, Ni ²⁺ in the aqueous phase was confirmed to be 20 g / L by analysis by EDTA titration method. Ni ²⁺ of the aqueous phase to adjust the pH of the aqueous phase, further electroless nickel obtained by adjusting the Ni ²⁺ concentration by shortage of supply of Ni ²⁺ with concentrated or diluted, or nickel sulfate, etc. It can be supplied directly to the plating tank or supplied to the nickel ion replenishing tank for use.

Meanwhile electrodialysis process demetallization plating solution passing through the cation exchange resin, the electrolytic dialysis of demetallization plating solution metal ions adsorbed on the cation exchange resin was carried out as follows.
The apparatus shown in FIG. 2 was used. In Figure 2, 20 is an electrolytic dialysis cell, 21 is an anode, 22 denotes a cathode, an anode 21, anode chamber 21a partitioned by the respective cathode 22 cation-exchange membranes 23 and 24, disposed in the cathode chamber 22a Has been.
Furthermore, the electrolytic dialysis cell 20 mono Selective anion exchange membrane 25 to the anode chamber 21a side, mono- Selective cation exchange membrane 26 is disposed in the cathode chamber 22a side, demetallization plating solution in the central portion The supply chamber 27 is divided into three chambers: a monovalent anion chamber 28 on the anode chamber 21a side and a monovalent cation chamber 29 on the cathode chamber 22a side. The monovalent anion chamber 28 and the monovalent cation chamber 29 communicate with each other through pipes 30a and 30b .

In this case, the following was used as the exchange membrane.
(Cation exchange membrane)
Astom Neoceptor CMX
(Monoselective anion exchange membrane)
Astom Neoceptor ACS Co., Ltd.
(Monoselective cation exchange membrane)
Astom Neoceptor CIMS

The anode chamber 21a and the cathode chamber 22a each contain a 10% by weight aqueous sulfuric acid solution, and the monovalent anion chamber 28 contains 1 g / L sodium hypophosphite. after the pH of the de metal plating solution which has passed through the cation exchange resin was adjusted to 9.0 with NaOH, which was supplied to the demetallization plating solution chamber 27 were electrolytic dialysis under the following conditions.

(Electrolytic dialysis conditions)
Voltage: 15V
Current: 1A
Temperature: 30 ° C
Demetalized plating supply amount: 1L
Processing time: 30 minutes

  In this case, the liquid in the monovalent anion chamber 28 and the monovalent cation chamber 29 is continuously discharged to the monovalent ion storage tank 31, and the monovalent anion chamber 28 and the monovalent cation chamber 29 are again discharged from the monovalent ion storage tank 31. On the other hand, the liquid in the demetalization plating solution supply chamber 27 was discharged to the divalent anion storage tank 32 and supplied and circulated from the divalent anion storage tank 32 to the demetalization plating solution supply chamber 27. The demetalized plating solution can also be supplied to the demetalized plating solution supply chamber 27 from the divalent anion storage tank 32 after once being supplied to the divalent anion storage tank 32 after pH adjustment.

As described above, by performing the electrolytic dialysis, as shown in FIG. 2, hypophosphite ions demetallization plating solution (H ₂ PO ₂ ^-) is a mono-selective anion-exchange membrane 25 Passing into the monovalent ion storage tank 31, phosphite ions (HPO ₃ ²⁻ ) and sulfate ions (SO ₄ ²⁻ ) cannot pass through the monoselective anion exchange membrane 25, and supply a metal removal plating solution. to the chamber 27 door etc. round. Among the complexing agents, monovalent acetate ions pass through the monoselective anion exchange membrane 25 and enter the monovalent ion storage tank 31, but divalent succinate ions are monoselective anion exchange membrane 25. since not pass through the APPLICATION etc. circle demetallization plating solution supply chamber 27.

On the other hand, H ⁺ passes through the monoselective cation exchange membrane 26 and enters the monovalent cation chamber 29. In this case, the mono-selective cation exchange membrane 26, using the Neosepta CIMS, since the membrane permeation hole is relatively small, H ⁺ so easy preferentially pass from the Na ^+, Na ⁺ majority or more There for whole etc. preparative de metal plating liquid supply chamber 27, pH of the chamber 27 is maintained at 8.5 or more.

Doing the above electrolytic dialysis conditions, in the processing time (30 minutes), the ion concentration in the monovalent ion reservoir were as follows.
Before dialysis (from aging solution)
Hypophosphite Na 30g / L
Phosphorous acid 100g / L
Acetic acid 15g / L
Succinic acid 15g / L
After dialysis, monovalent ion storage tank Hypophosphite Na 60g / L
Acetic acid 30g / L
・ Divalent anion storage tank Phosphorous acid 2g / L
Succinic acid 1g / L
(Sulfuric acid) 3g / L

  As described above, the monovalent anion and the divalent anion in the metal removal plating solution are separated, and the treated liquid in the monovalent ion storage tank 31 contains a phosphite ion and a monovalent complexing agent. After each concentration adjustment and pH adjustment, it can be used directly by supplying it to an electroless nickel plating tank or a hypophosphite supply tank. The treated chamber in the divalent anion storage tank 32 contains phosphorous acid, sulfuric acid, and a divalent complexing agent, which can be disposed of by performing appropriate treatment.

Further, 27.5% by volume of an aqueous phase containing nickel sulfate at a Ni ²⁺ concentration of 20 g / L after the above impurity metal ion removal treatment, 50% by volume of the monovalent ion storage tank solution, and 22.5% of ion-exchanged water. Mix volume% and add succinic acid which is insufficient plating composition to this composition. Nickel sulfate (as Ni2 ⁺ ) 5.5g / L
Sodium hypophosphite 30g / L
Acetic acid 15g / L
Succinic acid 15g / L
pH adjustment 4.4
An electroless nickel plating solution was newly constructed.
Plating treatment was performed using this plating solution by a normal method, but a deposition rate and a film appearance that were the same as those of normal plating were obtained.

DESCRIPTION OF SYMBOLS 1 Electroless-plating storage tank 2 Electroless-plating liquids 3 and 7 Pump 4 Cation exchange resin tower 5 Demetalization plating liquid storage tank 6 Elution liquid tank 8 Elution liquid 9 Impurity metal separation tank 10 Separation tank 11 Back extraction tank 12 Concentration adjustment tank 13 demetallization plating solution 14 pH adjusting agent tank 20 electrolytic dialysis cell 21 anode 22 cathode 21a anode chamber 22a cathode chamber 23, 24 cation-exchange membrane 25 mono Selective anion exchange membrane 26 mono Selective cation exchange membrane 27 de Metal plating solution supply chamber 28 Monovalent anion chamber 29 Monovalent cation chambers 30a and 30b Pipe 31 Monovalent ion storage tank 32 Divalent anion storage tank

Claims (7)

An electroless plating solution containing main metal ions, hypophosphite ions, complexing agents of the above main metal ions, and phosphite ions is passed through the cation exchange resin, and the cation exchange resin is passed through the plating solution. A main metal ion and an impurity metal ion contained in the cation exchange resin, and a process for passing the demetalized plating solution containing hypophosphite ion and phosphite ion separated from the metal ion; the adsorbed metal ions eluted in the eluent, the main metal ions to remove impurity metal ions from the metal ion of the eluent during the separation, a process of recovering, the demetallization plating solution electrolytic dialysis treatment to The monovalent anion solution containing hypophosphite ions and monovalent complexing agent ions is separated from the polyvalent anion solution containing phosphorous acid and bivalent or higher complexing agent ions. And a method of reproducing an electroless plating solution; and a process of discarding the polyanion solution.   The regeneration method according to claim 1, wherein the treatment for separating the impurity metal ions from the main metal ions is performed by an organic solvent extraction method.   The regeneration method according to claim 1 or 2, wherein the main metal ions from which the impurity metal ions have been separated and removed are subjected to an organic solvent extraction treatment to concentrate the main metal ions. Electrolytic dialysis treatment, selectively transmits hypophosphite ions and monovalent complexing agent ions de metal plating solution, a mono-selective anion-exchange membrane which does not transmit a divalent or more anions, H ⁺ selectively using the electrolytic dialysis cell equipped with a mono-selective cation-exchange membrane that transmits, demetallization plating solution to be treated between the mono selective anion exchange membrane and mono selective cation exchange membrane the method of regeneration according to any one of claims 1 to 3 is supplied to electrolytic dialysis process the.   The regeneration method according to any one of claims 1 to 4, wherein the electroless plating solution is an electroless nickel plating solution.   The regeneration method according to any one of claims 1 to 5, wherein the electroless plating solution to be treated is an electroless plating solution to be disposed of by increasing accumulation of phosphorous acid.   The electroless plating solution to be treated is an electroless plating solution that is in use. The main portion of the metal ions, hypophosphite ions, and 1 recovered by extracting a part or all of the plating solution from the plating solution. The regeneration method according to any one of claims 1 to 5, wherein a complexing agent ion having a valence is supplied and circulated to the plating solution.

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