CN105209667B

CN105209667B - Manganese (III) ion in strength sulfuric acid it is electrolytically generated

Info

Publication number: CN105209667B
Application number: CN201480014056.0A
Authority: CN
Inventors: T·皮尔逊; T·克拉克; R·V·查帕内利; C·罗宾森; A·西斯洛普; A·辛
Original assignee: MacDermid Acumen Inc
Current assignee: MacDermid Acumen Inc
Priority date: 2013-03-12
Filing date: 2014-03-07
Publication date: 2017-12-05
Anticipated expiration: 2034-03-07
Also published as: BR112015021067A2; PT2971260T; CA2955467A1; JP2016512574A; DK2971260T3; CA2901589C; CN105209667A; KR101749947B1; EP2971260A1; MX2015012584A; PL2971260T3; WO2014164272A1; CA2901589A1; TW201500593A; ES2745071T3; BR112015021067B1; JP6167222B2; SI2971260T1; HRP20191626T1; EP2971260A4

Abstract

A kind of method that manganese (II) ion electrochemical is oxidized to manganese (III) ion This application describes electrolytic cell and in the electrolytic cell.The electrolytic cell includes the electrolyte solution of manganese (II) ion that (1) is at least one sour solution；(2) negative electrode being immersed in the electrolyte solution；(3) anode for being immersed in the electrolyte solution and being separated by with the negative electrode.Describe various anode materials, including vitreous carbon, reticulated vitreous carbon, weaving carbon fiber, lead and metal.Once the electrolyte is oxidized and forms the metastable state complex compound of manganese (III) ion, then can plate plastics and the metastable state complex thereof can plate plastics to etch this.In addition, before this can plate plastics and the metastable state complex thereof, also it can plate pre-treatment step is carried out on plastics to nurse one's health the situation of the frosting at this.

Description

Manganese (III) ion in strength sulfuric acid it is electrolytically generated

Cross reference related application

The application be the application number 13/677,798 still in examination at present submitted on November 15th, 2012 part after Continuous, this application is that the part for the application number 13/356,004 still in examination at present submitted on January 23rd, 2012 is continued, they Respective theme is all hereby incorporated by reference in its entirety by quoting.

Technical field

Present invention is generally directed to a kind of modification method for plating plastics for being used to etch such as ABS and ABS/PC.

Background technology

As is generally known in the art for a variety of purposes and with metal-plated non-conductive substrate (that is, plastics).Plastic shaping is given birth to Produce relatively cheap, and metalized plastics are used for many applications.For example, metalized plastics are used to decorate and for manufacturing electricity Sub- equipment.The example of decorative use includes auto parts, such as automotive trim.The example of electronic applications includes printed circuit board (PCB), The metal wherein electroplated with selective pattern includes the conductor of printed circuit board (PCB), and the metalized plastics for EMI shieldings. ABS resin is the plastics being most often plated for cosmetic purposes, and phenol resin and epoxy resin be in printed circuit board (PCB) manufacture most The plastics being often plated.

Plating on frosting be used to produce various articles of consumption.The production of plastic shaping is relatively cheap, and Platable material is used for many applications, including automotive trim.The plating of plastics is related to many stages.First stage is related to etching modeling Material, is sticked together with providing the machinery of subsequent metal overlay film, and provides the absorption that suitable surface is used for palladium catalyst, the palladium chtalyst Agent is typically to the deposition of the catalysis initial metal layer from autocatalysis nickel or copper-plating technique.Then, can apply deposited copper, nickel and/ Or the sedimentary of chromium.

The initial etch of plastic assembly is the pith of whole process.However, the plastic assembly of only certain type is fitted Close plating.The plastic type for being most commonly used for plating is acrylonitrile/butadiene/styrene (ABS) or ABS and makrolon Admixture (ABS/PC).ABS is by two phase compositions.The relatively hard phase that first phase is made up of acrylonitrile/styrol copolymer, the Two-phase is softer polybutadiene phase.

At present, this material is etched using the mixture of chromic acid and sulfuric acid, and this is for ABS and ABS/PC right and wrong Normal effective etchant.The polybutadiene of the plastics mutually contains double bond in the backbone of polymer, and it is aoxidized by chromic acid, thus is made Into the complete fracture and dissolving of the polybutadiene phase exposed to the frosting, reach effective etching of the frosting.

One problem of traditional chromic acid etching step is that chromic acid is considered as carcinogenic substance, and control it is all the more strict, it is necessary to Substitute chromic acid with safer substitute as far as possible.The use of chromic acid etchant also has known critical defect, including chromaking The toxicity of compound, cause its disposal difficult, the chromic acid residue suppression electroless deposition stayed on polymer surfaces, and handling Chromic acid residue to be rinsed from the polymer surfaces difficult afterwards.In addition, the Cr VI sulfuric acid solution of heat has natural danger for worker Danger.The worker Chang You of these chromium etching solutions of everyday exposure burns and upper respiratory tract hemorrhage.Therefore, expect that very much development is acid The safer substitute of chromium etching solution.

Early stage is generally focused on replacing using high manganese ion as chromic acid by the use of the trial of chromic acid to substitution etching plastics For thing.Describe permanganate in Tubergen et al. U.S. Patent No. 4,610,895 to be applied in combination with sour, its full text It is herein incorporated by reference.Later, No. 2005/0199587 suggestion permanganic acid of Bengston U.S. Patent Application Publication No. Salt is applied in combination with ionic palladium activation stage, and it is incorporated by reference in its entirety herein.Satou U.S. Patent Application Publication No. 2009/0092757 describes sour permanganate solution and is combined with high halide ion (for example, perchlorate or periodate) Use, it is incorporated by reference in its entirety herein.Finally, Enthone International Publication No. WO 2009/023628 is described High manganese ion is used in the case of no alkali metal or alkaline earth metal cation, it is incorporated by reference in its entirety this Text.

Stahl et al. U.S. Patent No. 3,625,758 also illustrates permanganate solution, and it is incorporated by reference It is incorporated herein.Stahl suggested chromium and the adaptability of sulfuric acid bath or permanganate solution for preparing surface.In addition, Courduvelis et al. U.S. Patent No. 4,948,630 is incorporated by reference in its entirety herein, and which depict a kind of hot Alkaline permanganate solutions, it also contains a kind of material, such as sodium hypochlorite, and its oxidizing potential is higher than the oxygen of permanganate solution Change current potential.Cane U.S. Patent No. 5,648,125 is incorporated by reference in its entirety herein, and which depict use to include Gao Meng The Alkaline permanganate solutions of sour potassium and sodium hydroxide, the wherein permanganate solution are maintained at high temperature, i.e. about 165 ℉ are extremely 200℉。

It can be seen that, it has been suggested that many kinds of etching solution substitution chromic acid are used for the technique for preparing metallization non-conductive substrate In.However, due to various economy, performance and/or environment, these techniques are not yet proved to be gratifying, because This these technique not yet reaches business success or is received to turn into the substitute for being adapted to chromic acid etching by industry.In addition, these with The stability of etching solution based on permanganate may also be bad, causes the formation of manganese dioxide sludge.

The solution that inventor has studied based on permanganate forms sludge and the tendency of itself decomposition occurs. Under strong acidic environment, according to following reaction, high manganese ion can react with hydrogen ion, produce manganese (II) ion and water：

4MnO₄ ^-+12H⁺→4Mn²⁺+6H₂O+5O₂ (1)

Manganese (II) ion and then can further be reacted with high manganese ion that this reaction is formed, according to following anti- Should, form manganese dioxide sludge：

2MnO₄ ^-+2H₂O+3Mn²⁺→5MnO₂+4H⁺ (2)

Therefore, either produced by the alkali metal salt of permanganate and the high manganese ion or electrochemical in-situ added Raw high manganese ion, the formula based on highly acid permanganate solution are substantially unstable.Compared to the chromium used at present Acid etching, the adverse chemical stability of acid permanganate make it conscientiously useless for large-scale commercial applications application.It is alkaline high Manganate etching is more stable, and is widely used in printed circuit board industry, for etching epoxy printed circuit board (PCB), but alkali Property permanganate is not effective etchant for such as ABS or ABS/PC plastics.Therefore, manganese (VII) can not be made For the etchant degree of gaining broad commercial acceptance of these materials.

ABS trial is etched without using chromic acid including the use of silver-colored (II) caused by electrochemistry and cobalt (III).It is some Metal can be anodized the state of oxidation for high oxidation.For example, cobalt (III) can be oxidized to from cobalt (II) for cobalt and silver can be from silver (I) it is oxidized to silver-colored (II).

However, currently without suitable for plastics based on permanganate (no matter for acid or alkali form) or any other oxidation The manganese of state or by using it is other acid or oxidant suitable business success etchants.

Therefore, this area stills need a kind of without chromic acid and for the etchant of the acceptable improvement of business, and it is used to prepare Subsequently electroplate the plastic base used.

The content of the invention

It is an object of the present invention to provide a kind of etchant without chromic acid for plastic base.

It is a further object of the present invention to provide a kind of acceptable etchant of the business for plastic base.

It is a further object of the present invention to provide a kind of etchant based on manganese ion for plastic base.

The a further object of the present invention is to provide one kind and is suitable in strong acid oxidization electrolysis matter but not by the electrolyte degradation Electrode.

The present invention a further object be to provide a kind of business it is acceptable be suitable in strength sulfuric acid produce manganese (III) from The electrode of son.

The a further object of the present invention is to provide a kind of pretreatment step for being used to nurse one's health the improvement of plastic base before etching Suddenly.

In one embodiment, present invention is generally directed to a kind of electrolytic cell, it is included：

Electrolyte solution, it includes manganese (III) ion in the solution in sulfuric acid and additional acid, and the additional acid is selected from The group being made up of Loprazolam, methane-disulfonic acid and combinations thereof；

Negative electrode, itself and the electrolyte solution contacts；And

Anode, itself and the electrolyte solution contacts.

In another embodiment, present invention is generally directed to a kind of electrolytic cell, it is included：

Electrolyte solution, it includes manganese (III) ion being at least one sour solution；

Negative electrode, itself and the electrolyte solution contacts；And

Anode, itself and the electrolyte solution contacts, the wherein anode are included from by vitreous carbon, reticulated vitreous carbon, braiding carbon The material selected in the group that fiber, lead, metal and foregoing one or more combination are formed.

In another embodiment, present invention is generally directed to a kind of side for the solution for preparing etchable plastic base Method, this method comprise the following steps：

Electrolyte is provided in electrolytic cell, the electrolyte includes manganese (II) ion at least one sour solution Solution, the wherein electrolytic cell include anode and negative electrode；And

Apply current to the anode and negative electrode of the electrolytic cell；And

The electrolyte is aoxidized to form manganese (III) ion, wherein manganese (III) ion forms metastable state complex compound.

In another embodiment, present invention is generally directed to be suitable for manganese (II) ion-conductance in strong acid solution Chemical oxidation is the electrode of manganese (III) ion.

In another embodiment, manganese (II) ion electrochemical is oxidized into manganese present invention is generally directed to one kind (III) method of ion, comprises the following steps：

Electrolyte is provided in electrolytic cell, the electrolyte is included in the molten of manganese (II) ion at least one sour solution Liquid, the wherein at least one acid include sulfuric acid and additional acid, the additional acid selected from by Loprazolam, methane-disulfonic acid and its The formed group of combination, the wherein electrolytic cell include anode and negative electrode；

Apply electric current between the anode and the negative electrode；And

In a further embodiment, present invention is generally directed to a kind of method for etching plastic components, this method includes The plastic components is contacted with comprising manganese (III) ion and at least one sour solution.

Embodiment

Present inventors have found that can be in strong acid solution, preferably in strength sulfuric acid solution, most preferably at least In 8M sulfuric acid solution, divalent manganesetion is electrolysed under low current density easily to produce manganic.More particularly, it is of the invention Inventor have been found that the Manganic ion solution in strongly acidic solution can etch ABS.

Manganic is unstable and with high oxidative (is relative to the standard oxidationreduction potential of standard hydrogen electrode 1.51).In the solution, it is manganese dioxide and two that it is quickly disproportionated (disproportionate) via following reaction Valency manganese：

2Mn³⁺+2H₂O→MnO₂+Mn²⁺+4H⁺ (3)

However, in strength sulfuric acid solution, Manganic ion becomes metastable (meta-stable), and it is purple/red to form cherry The sulfate complex of color.Inventor has found that this sulfate complex is the medium for being adapted to etching ABS, and with perhaps The advantages of more Chrome-frees better than prior art etch.

Therefore, in one embodiment, present invention is generally directed to a kind of prepare can etch the solution of plastic base Method, this method comprises the following steps：

Electrolyte is provided in electrolytic cell, it is molten that the electrolyte includes manganese (II) ion being at least one sour solution Liquid, the wherein electrolytic cell include anode and negative electrode；And

Apply current to anode and the negative electrode of the electrolytic cell；And

In a preferred embodiment, the plastic base includes ABS or ABS/PC.

Although it is contemplated that phosphoric acid is all suitable for the composition of the present invention with sulfuric acid, but in a preferred embodiment, the acid For sulfuric acid.At room temperature, the half-life period of manganese (III) ion is 2 years or so in 7M sulfuric acid.Contrastingly, the phase in 7M phosphoric acid Half-life period with manganese (III) ion of concentration is about 12 days.Speculate higher stability of manganese (III) ion in sulfuric acid be by In foring manganese-sulfate complex and obtainable hydrogen ion concentration is higher in sulfuric acid solution.Use the another of phosphoric acid Problem is the limited solubility of manganese phosphate (III).Therefore, although the other of such as phosphoric acid can be used in the composition of the present invention Inorganic acid, it is usually preferable to using sulfuric acid.

In use, notable stability of manganese (III) ion in strength sulfuric acid provides advantages below：

1) because manganese (III) ion is formed under low current density, the electricity needs of the technique is generally very low.

2) because the anode operates under low-down current density, therefore can use small for annode area Negative electrode, to prevent the cathodic reduction of manganese (III) ion.This eliminates the demand for separating pond, and causes etchant regenerated reactor Engineering it is simpler.

3) because the technique does not produce high manganese ion, therefore manganese heptoxide (this can not possibly be produced in the solution It is safety hazard thing, because its great explosivity).

4) due to the high stability of manganese (III) ion in strength sulfuric acid, therefore the etchant can direct marketing use.In life In production, the etchant only needs a small regenerated reactor in the side of groove, to maintain the manganese of etching solution (III) content and prevent The accumulation of manganese (II) ion.

5) because other etch process are based on permanganate, therefore permanganate and the result of the reaction of manganese (II) ion are made The lifetime very short into quick " sludge " of manganese dioxide and the etching solution.This is for the erosion based on manganese (III) It should not be problem (although there may be some disproportionations over time) to carve liquid.

6) any poisonous gas will not be produced according to the present invention, the electrolytically generated of manganese (III).Although one can be produced in negative electrode A little hydrogen, due to low current demand, this is less than hydrogen caused by many electroplating technologies.

As described herein, in a preferred embodiment, the acid is sulfuric acid.The concentration of sulfuric acid is preferably at least 8 moles, more Add preferably from about 9 to about 15 moles.In the process, the concentration of sulfuric acid is important.Concentration is below about 9 moles, etch-rate It is slack-off, more than 14 moles, then in solution manganese ion solubility step-down.In addition, the sulfuric acid of very high concentration tends to from air Moisture is absorbed, and has harm for operation.Therefore, in most preferred embodiments, the concentration of sulfuric acid is about 12 to 13 to rub You, it is dilute enough to add water to etching to add safely, and sufficiently strong to optimize the etch-rate of plastics.In the sulfuric acid of this concentration Under, it can dissolve up to about 0.08M manganese sulfate in the preferred operations temperature of etching.For optimal etching, in solution manganese from It is how high that the concentration of son should can reach more higher positions for it.

Although manganese (II) ion in other similar sources as known in the art can also be used in an embodiment of the present invention, But manganese (II) ion is preferably chosen from the group being made up of manganese sulfate, manganese carbonate and manganous hydroxide.Manganese (II) ion it is dense Degree may range from about 0.005 mole to saturation.In one embodiment, the electrolyte also includes colloidal silica manganese.This can Formed, or can specially be added with being manganese (III) is disproportionated in solution to a certain extent natural result.

Manganese (III) ion can easily be produced by the oxidation of manganese (II) ion by electrochemical appliance.In addition, generally It is preferred that the electrolyte does not include any high manganese ion.

As described herein, in order to obtain fast etch rate for ABS plastic, it is necessary to acid using high concentration.Need The presence of sulfate radical or hydrogen sulfate ion, to form complex compound with manganese ion, and at least need 8M sulfuric acid molar concentration With the good stability etched.In order to which good plastics etch, it is found that fast-etching needs at least about 12M sulfuric acid dense Degree.This has the effect for reducing manganese ion dissolution degree in bath, and manganese ion maxima solubility is about in bath at the operational 0.08M.Because etch-rate depends on the concentration of manganese (III) ion in solution and is used for the maximum conversion percentage for maintaining stability The manganese amount that be may be dissolved in than for about 50%, it is expected increase in bath.

Inventor, which has found, to replace a part of sulfuric acid by another acid to increase the manganese amount that may be dissolved in bath, its Middle manganese ion can have more dissolubility.

Suitable acid selection is limited.For example, hydrochloric acid can produce chlorine in anode, and nitric acid can produce nitric oxide in negative electrode. Perchloric acid is expected with periodic acid can produce high manganese ion, and it can resolve into manganese dioxide.Organic acid typically can be by manganese (III) ion Quick Oxidation.Therefore, there is required stability for oxidation and increases the ability of manganese ion dissolution degree in bath Acid be Loprazolam and methane-disulfonic acid.Due to manganese (II) solubility in the Loprazolam (with sulfuric acid) ratio in methane two Significantly more preferable in sulfonic acid, the former selection produces better performance.Therefore, Loprazolam is preferable additional acid, and sulfuric acid It is preferable main acid.

More than being based on, the present invention further relates to a kind of electrolyte for being used to etch ABS and ABS/PC plastics in general, comprising Sulfuric acid, and Loprazolam or methane-disulfonic acid is applied in combination, with more preferable manganese ion dissolution degree in being bathed, the wherein electrolysis Matter contains at least 8M sulfuric acid and includes about 0M to about 6M Loprazolam or methane-disulfonic acid, preferably from about 1M to about 6M first Alkyl sulfonic acid.

More particularly, present invention is generally directed to a kind of electrolytic cell, comprising：

Electrolyte solution, comprising manganese (III) ion in the solution in sulfuric acid and additional acid, the additional acid be selected from by The group that Loprazolam, methane-disulfonic acid and combinations thereof are formed；

Negative electrode, itself and the electrolyte solution contacts；And

Anode, itself and the electrolyte solution contacts.

In addition, the present invention further relates to a kind of electrolytic cell in general, comprising：

Electrolyte solution, include manganese (III) ion at least one sour solution；

Negative electrode, itself and the electrolyte solution contacts；And

In addition, the present invention further relates to a kind of side that manganese (II) ion electrochemical is oxidized to manganese (III) ion in general Method, comprise the following steps：

Electrolyte is provided in electrolytic cell, wherein the electrolyte include the manganese (II) that is at least one sour solution from Sub- solution, the wherein electrolytic cell include anode and negative electrode；

Apply electric current between the anode and the negative electrode；And

Once the electrolyte is oxidized to form metastable state complex compound, this can be plated to plastics and be immersed in the metastable state network A period of time, the surface of plastics can be plated to etch this in compound, in one embodiment, should at a temperature of 30 to 80 DEG C Plastics can be plated to be immersed in the metastable state complex compound.Etch-rate with temperature raise and increase and less than 50 DEG C it is slow.

The upper limit of temperature is determined by the property for the plastics being etched.ABS starts to deform more than 70 DEG C, therefore excellent In the embodiment of choosing, particularly when etching ABS material, the temperature of electrolyte is maintained at about 50 to about 70 DEG C.Plastics soak Time in the electrolyte is preferably from about 10 to about 30 minutes.

The object etched in this way can subsequently be electroplated using for being plated the conventional pretreatment of plastics, or Person can promote sticking together for coating, paint or other face coats using the surface of the etching of the plastics.

The concentration of manganese (II) ion used in the etching of the present invention can be determined by volt-ampere round-robin method.Oxidation by Controlled to diffusion, therefore need in the electrolytic acid cleaning oxydation process effectively to stir etching solution.

Workable anode may include various materials with negative electrode in electrolytic cell described herein.Negative electrode may include from by The material that the group that platinum, platinized titanium, niobium, the titanium of yttrium oxide cladding and lead are formed selects.In a preferred embodiment In, negative electrode includes platinum or platinized titanium.In another preferred embodiment, negative electrode includes lead.Anode may also comprise platinized titanium, Platinum, iridium/tantalum pentoxide, niobium, boron doped diamond or any other suitable material.

Inventor has found, although the combination of manganese (III) ion and strength sulfuric acid (that is, 8~15 moles) can etch ABS modelings Material, but the etchant also has aggressivity very much to electrode necessary to producing manganese (III) ion.Especially, there is titanium-based The anode of plate can be by the etchant fast degradation.

Therefore, it is determined that in the trial of more appropriate electrode material, various other electrode materials is tested, include lead and stone Ink.Vitreous carbon and reticulated vitreous carbon are considered as firmer, and are preferably 0.1~0.4A/dm when applying²(based on nominal Surface area) electric current when, manganese (III) ion can be produced.Further, since vitreous carbon and reticulated vitreous carbon conduct in commercial applications Electrode does not have cost effectiveness, therefore anode can also be manufactured and obtained by weaving carbon fiber.

Carbon fiber is obtained from the fiber manufacture of polyacrylonitrile (PAN).These fibers are at increased temperature through peroxidating Technique, then carry out in very high temperature and under an inert atmosphere carburising step.The carbon fiber is then prepared for sheet, its Generally it is used in combination with various resin systems, produces high intensity component.Carbon fiber sheet also has good electrical conductivity, and should Fiber generally has random layer (turbostratic) (that is, disordered layer) structure.It is not intending to be bound by theory, it is believed that this structure causes carbon Fiber is effective as electrode.The SP in lattice²The carbon atom of hydridization provides good electrical conductivity, and SP³The carbon of hydridization is former Son is linked together with graphite linings, and their position is fixed, thus provides good chemical resistance.

Include for the preferred material in the electrode of the present invention containing at least 95% carbon and be not impregnated with any resin Weaving carbon fiber.For the ease of processing and weaving, carbon fiber is generally with epoxy resin starching (sizing), and this can be accounted for According to most the 2% of fibre weight.With this low percentage, when as electrode, the high sulfuric acid content that epoxy starching is etched is fast Speed removes.This can cause the initial mild of etching solution to change colour, but not influence performance.In this initial " break-in " after the stage, sun Pole, which is shown, can resist the electrolyte, and the efficient oxidation manganese (II) ion turns into manganese (III).

Can be by fixing the weaving carbon fiber material in the framework for being suitably provided with electrical contact and construction anode.May be used also Carbon fibre material is used when producing manganese (III) ion as negative electrode, but uses lead more convenient, if particularly used In the case that negative electrode is significantly less than anode when not separating pond.

The current density sections applied in the electrolytic cell are limited to the oxygen overpotential on selected anode material.Example Such as, in the case of platinized and titanized anode, current density about 0.4A/dm²On, anode potential is sufficiently high to discharge oxygen.Now, The transformation efficiency that manganese (II) ion turns into manganese (III) ion declines, thus wastes any further increased current density.Again Person, produce more high current density needed for more exceed potential operations anode tend to anode surface produce manganese dioxide rather than Manganese (III) ion.

It was surprisingly found that lead anode can be effectively used in electrolytic cell described herein.Due in surface shape Into sulfuric acid lead layer, it has very limited amount of solubility in sulfuric acid, therefore lead becomes to be passivated in strong acid.This make it that anode is blunt Change, until reaching very high overpotential (relative to standard hydrogen electrode more than 2V).Higher than this horizontal current potential, oxygen is produced With the mixture of brown lead oxide.Although it is contemplated that this height operation current potential is advantageous to oxygen generation and high manganese ion rather than manganese (III) formation of ion, but only produce manganese (III) ion and without permanganate using the experiment of lead anode.This can be by using Water dilutes etching solution and confirmed, manganese (III) ion disproportionation produces brown manganese dioxide and manganese (II) ion.The filtering production of the solution The high manganese ion of raw actually colourless manganese (II) solion characteristic rather than purple.

It has been found by the inventor that because oxidation of these anodes for manganese (II) ion has very high effect Rate, therefore, it is necessary to monitor the speed of oxidation when using lead anode.Thus, if the speed of oxidation by monitoring and does not control, There is too a high proportion of manganese (II) ion to be oxidized, leave very low concentration of manganese (II).When without manganese (II) ion, anode starts Manganese oxide (III) ion turns into manganese (IV), and it quickly forms insoluble manganese dioxide.

Based on described above, it is important that no more than original concentration 50%, and preferably more than 25% manganese (II) ion Manganese (III) ion is oxidized to, to maintain the stability of the electrolyte.In the case of lead anode, this is related to by the etching The titration of solution monitors the accumulation of manganese (III) ion and when manganese (III) content reaches expectation using oxidation-reduction electrode During amount, stop the electrolysis.When sulfuric acid concentration is 12.5M, it is necessary to have the manganese of the concentration more than 0.01M (III) ion to be used for Effectively etching and maximum stability, and 0.04M is no more than based on total manganese content 0.08M.

Anode may include that lead or suitable metal, and selected types of alloys can influence conversion efficiency.Pure lead or Lead comprising small scale tin is especially effective, and caused conversion efficiency is about 70%.It has also been found that with the stirring of resonable degree, Can surprisingly high current density be applied and still maintain this switching rate.

After long-time electrolysis is carried out using lead anode, find to ultimately form the film of manganese dioxide.Once significant quantity Manganese dioxide has concentrated at electrode surface, and it tends to quickly thickening.However, manganese dioxide can be easily electrochemical Be reduced to manganese (II) ion.Therefore, it can mitigate by periodically making the method that electric current is reverse in pond or exclude manganese dioxide Accumulation.Time cycle between more primary currents are reverse is not crucial, if reversal phase apply enough coulomb electric charges with The amount for the manganese dioxide for being deposited on surface is reverted back into manganese (II) ion.

Based on described above, when being reached using lead with lead alloy with producing manganese (III) ion in sulfuric acid solution When etching ABS or ABS/PC purpose, suitable working concentration is reached in manganese (III) ion, i.e., based on total manganese content It is now preferred to interrupt electrolysis program so as to leave in the solution when the 0.08M suitable working concentrations can be 0.01 to 0.04M Manganese (II) ion of effective dose, thus bathe stabilization and excessive manganese dioxide will not be deposited.Preferable electrode material includes example Such as pure lead, the lead antimony containing about 4% antimony, contain for up to lead-tin anode of 5% tin and lead/tin/calcium anode.The present invention's Other suitable metals can also be used in implementation.In addition, the use for the electric current being periodically reversed prevents from accumulating titanium dioxide in anode Manganese film.This effectively maintains the transformation efficiency of anode, and reduces or exclude to remove and cleaning sun from etching groove or regenerated reactor The demand of pole.

In addition, in order to effectively produce manganese (III) ion, it usually needs use the annode area bigger than cathode area.It is excellent Selection of land, the anticathode area ratio of anode are at least about 10:1.Thereby, negative electrode directly can be soaked in the electrolyte, and is not required to To have and separate pond.Although the technique, which can be used, separates pond configuration work, this can bring unnecessary complexity and expense.

Illustrate the present invention referring now to following non-limiting example：

Comparative example 1：

12.5 mol sulfuric acids (500 milliliters) solution of 0.08 mol sulfuric acid manganese (II) is heated to 70 DEG C, and will be a piece of The ABS that grade can be plated is immersed in the solution.Even in this solution is immersed after 1 hour, the test board is also without recognizable Etching, and after the washing, the surface " does not soak ", and will not support uncracked moisture film.

Embodiment 1：

It is 1dm by immersing area²Platinized and titanized anode and surface area 0.01dm²Platinum plating Ti cathode in the molten of comparative example 1 In liquid and apply 200mA electric current 5 hours, be electrolysed the solution.

In the electrolytic process, it is found that the solution colour changes to very dark purple/red from almost colourless.Confirm without height The presence of Manganate ions.

Then this solution is heated to 70 DEG C, and a piece of ABS for plating grade is immersed in the solution.In 10 points of immersion After clock, the test piece complete wetting, and uncracked moisture film is can support after being flushed., should after immersion 20 minutes Sample is cleaned in water, dried and detected with sweep electron microscope (SEM).This detection shows that the test piece is substantially lost Carve, and visible many etching recesses.

Embodiment 2：

With current density 0.2A/dm²Using platinized and titanized anode, electrolysis contains 12.5M sulfuric acid and 0.08M manganese sulfates (II) Solution.Usable floor area is less than the platinum plating Ti cathode of 1% annode area, to prevent the negative electrode in manganese caused by anode (III) ion Reduction.Electrolysis carry out for a long time transmit enough enough coulombs using by all manganese (II) ionic oxide formations as manganese (III).It is resulting Solution it is purple/red for deep cherry.High manganese ion is not produced in this step.This also confirms by visible spectrum, the manganese (III) ion produces the absorption spectrum for being totally different from permanganate solution.

Embodiment 3：

Etching solution as prepared by above-mentioned embodiment 2 is heated to 65~70 DEG C in magnetic stirrer/heating plate, and ABS test piece is immersed in the solution to 20~30 minutes a period of time.Some in these test pieces are detected by SEM, with And some test pieces (are plated with normal electroplating plastic pre-treatment sequence in M with inner reduction, pre-soaking, activation, acceleration, electroless nickel, copper To 25~30 microns) handle.Then these test pieces are annealed and carry out peel strength test using Instron machines.

30 minutes peel strength tests are carried out in plated test piece, show anaplasia of the peel strength in about 1.5 and 4N/cm Change.

The use of surface area is 0.196cm²Platinum rotating disc electrode (RDE) in different rotating speeds, from comprising 12.5M sulfuric acid with The solution of 0.08M manganese sulfates obtains volt-ampere circulation figure.Determine potentiometer (potentiostat) with what RDE was used in connection with model 263A With silver/silver chloride reference electrode.

In all cases, forward scan is shown in about 1.6V has a peak relative to Ag/AgCl, then for flat region extremely Near 1.75V, then electric current increase.Reverse scan produces similar in the flat region of slightly lower electric current and near 1.52V Peak.These results show that the dependence of electrode rotary speed mass transportation control is the Main Factors in the mechanism.This is flat Area indicates potential range, and manganese (III) ion is formed by electrochemical oxidation process on this potential range.

Carry out determining potentiometer scanning in 1.7V.It was found that electric current lands at the beginning, increase over time, become.In this current potential Current density in 0.15 and 0.4A/dm²Between change.

After testing herein, with fixed current density 0.3A/dm²Constant-current discharge (galvanostatic) is carried out to measure Examination.At the beginning, the current density of application is reached by about 1.5V current potential, but as experiment is carried out, after about 2400 seconds, It was found that current potential increases to about 1.75V.

After being etched more than 10 minutes, the surface complete wetting of the ABS test pieces is found, and is supported after the washing not The moisture film of rupture.After 20 or 30 minutes a period of time, the plate is substantially etched.

Embodiment 4：

Preparing includes the solution of 10.5M sulfuric acid and 2M Loprazolams.At 68~70 DEG C of temperature, 0.16M can be dissolved easily Manganese sulfate, but in 12.5M sulfuric acid solutions dissolve manganese sulfate be used for compare in the case of, only can dissolve 0.08M.Should The solution of preparation is electrolysed to produce manganese (III) ion of manganese (III) concentration as 0.015M, etch-rate of its offer can with from tool The speed that the 12.5M sulfuric acid solutions for having 0.015M manganese (III) concentration obtain compares favourably.

Continue electrolysis in the bath of embodiment 4, until manganese (III) content reaches 0.04M and another plate is etched. Etch-rate (high about 25%) of speed obtained by specific concentration 0.015M promoted under manganese (III) ion of this higher concentration.

Comparative example 2：

It is 1dm that graphite and the nominal surface area that measures will be included at a temperature of 65 DEG C²Electrode immerse 500 milliliters In solution containing 0.08M manganese sulfates in 12.5M sulfuric acid.Negative electrode in this pond is that the nominal surface area that measures is 0.1dm²Lead Piece.The electric current for applying 0.25 ampere obtains 0.25A/dm to the pond²Nominal anodic current density and 2.5A/dm²Nominal the moon Electrode current density.

Hair now less than in the electrolysis of 1 hour, simultaneously degrade by graphite anode rapid disruption.In addition, manganese (II) ion is not found It is oxidized into manganese (III) ion.

Comparative example 3：

The tantalum coated with mixing/iridium oxide coating (50% tantalum oxide, 50% oxidation will be included at a temperature of 65 DEG C Iridium) titanium-base and the nominal surface area that measures be 1dm²Electrode immerse 500 milliliters and contain 0.08M sulphur in 12.5M sulfuric acid In the solution of sour manganese.Negative electrode in this pond is that the nominal surface area that measures is 0.1dm²Lead flake.Apply 0.25 ampere of electric current To the pond, 0.25A/dm is obtained²Nominal anodic current density and 2.5A/dm²Nominal cathode-current density.

It was found that manganese (III) is quickly formed in the solution, and resulting solution can etch ABS plastic and can be follow-up Good stick together is produced during the plastics that plating is processed.However, operation two weeks (being electrolysed hour/day of solution 8) time it Afterwards, it is found that coat wrinkles from titanium-base, and titanium-base dissolves in the solution in itself.

Comparative example 4：

To be 1dm comprising the titanium-base for scribbling platinum and the nominal surface area that measures at a temperature of 65 DEG C²Electrode immerse 500 In the solution containing 0.08M manganese sulfates in 12.5M sulfuric acid of milliliter.Negative electrode in this pond is that the nominal surface area that measures is 0.1dm²Lead flake.The electric current for applying 0.25 ampere obtains 0.25A/dm to the pond²Nominal anodic current density and 2.5A/ dm²Nominal cathode-current density.

It was found that manganese (III) is quickly formed in the solution, and resulting solution can etch ABS plastic, and can be rear Good stick together is produced during the plastics that continuous plating is processed.However, in the time of operation two weeks (being electrolysed hour/day of solution 8) Afterwards, it is found that coating wrinkles from titanium-base, and titanium-base dissolves in the solution in itself.

Embodiment 5：

It is 0.125dm that vitreous carbon and the nominal surface area that measures will be included at a temperature of 65 DEG C²Electrode immerse 100 milliliters The solution containing 0.08M manganese sulfates in 12.5M sulfuric acid in.Negative electrode in this pond is that the nominal surface area that measures is 0.0125dm²Platinum line piece.The electric current for applying 0.031 ampere obtains 0.25A/dm to the pond²Nominal anodic current density and 2.5A/dm²Nominal cathode-current density.

It was found that manganese (III) is quickly formed in the solution, and resulting solution can etch ABS plastic, and can be rear Good stick together is produced during the plastics that continuous plating is processed.The electrode is obvious and is not affected by the influence of electrolysis time extension.

Embodiment 6：

Weaving carbon fiber piece (deriving from Zoltek companies, the Panex 3550K Tow with 1.5% epoxy starching) will be included Electrode be fixed in the plastic frame by polyvinylidene fluoride (PVDF) construction.Surface will be nominally measured at a temperature of 65 DEG C Product is 1dm²Electrode immerse in 500 milliliters of the solution containing 0.08M manganese sulfates in 12.5M sulfuric acid.The moon in this pond Pole is that the nominal surface area that measures is 0.1dm²Lead flake.The electric current for applying 0.25 ampere obtains 0.25A/dm to the pond²It is nominal Anodic current density and 2.5A/dm²Nominal cathode-current density.

It was found that manganese (III) is quickly formed in the solution, and resulting solution can etch ABS plastic, and can be follow-up Good stick together is produced during the plastics that plating is processed.The electrode is obvious and is not affected by the influence of electrolysis time extension.Use this Electrode was electrolysed more than two weeks, and was detected and do not found to degrade.The inexpensive and quick utilizability of this material is adapted for For many business applications.

Embodiment 7：

, will be by with 0.4dm at a temperature of 68~70 DEG C²Effective surface area (that is, not calculating electrode back) lead The anode of composition is immersed in the beaker containing 2 liters of solution containing 0.08M manganese sulfates in 12.5M sulfuric acid.It is another in the pond One electrode is made up of lead electrode, and the lead electrode has about 0.04dm²Surface area.The solution is stirred using magnetic stirrer, with Appropriate agitation is obtained in the surface of the electrolyte.Apply 0.4A/dm²Current density to the anode, and determine manganese (III) Relative to the speed of electrolysis time.The sample of the bath is diluted by phosphoric acid to determine the amount of manganese (III) to prevent manganese (III) discrimination Change, and titrated with l ferrous ammonium sulfate solution, using the diphenylamines being dissolved in acid as indicator.

Use 0.8A/dm²With 1.6A/dm²Current density repeat test.Under the fluid dynamics condition of experiment (i.e., Use the moderate agitation of magnetic stirrer), due to conversion efficiency and in 0.4A/dm²Resulting identical (70%), it is clear that in electricity Current density is 1.6A/dm², oxidation do not limit by mass transport.In 3.2A/dm²Further tested, and sent out Existing conversion efficiency has fallen to 42%, and the generation speed of manganese (III) is only than in 1.6A/dm²Resulting is high by 10%.This table It is bright, it is about 1.6A/dm for integrally limiting current density caused by manganese under the conditions of the agitation used in this experiment².This is suitable It is about four times so high for the switching rate that can be reached by platinized and titanized anode in switching rate.

The result explanation of these experiments, can be by using manganese (II) ion and using platinum in the sulfuric acid of rather high concentration Or the electrolysis that is operated under low current density of platinized and titanized anode and produce manganese (III) ion, and by using various other sun Pole material can further improve this method, and the various other anode materials include vitreous carbon, carbon fiber, lead and metal sun Pole.

Furthermore compared to the etch-rate for etching to obtain from chromic acid, the relatively slow erosion of the etching of the invention based on manganese Etching speed has been described above needing providing pre-treatment step, higher stick together value to produce and allows for shorter erosion Carve the time.

The purpose of the pre-treatment step is the situation on the surface of adjustment plastics to be etched, makes its etching more rapidly and It is even, shorter etching period is caused with preferably sticking together.

Situation using the surface of solvent adjustment ABS plastic is known.However, nearest specification is strictly limited in plate wire On using volatile solvent feasibility because they generally it is flammable and with health and safety problem (many for reproduction poison Property and liver can be caused to injure).Therefore, the selection of solvent is limited.

Propylene carbonate is comparatively safe solvent, and having good water solubility, hypotoxicity and low combustible, (flash-point is 135 DEG C), and be preferable for health and safety angle.Gamma-butyrolacton is also feasible, but more toxic, and one A little countries are controlled substance due to its recreational use.

In the present invention, it was discovered that the use when propylene carbonate and organic hydroxyl such as lactic acid, glycolic or gluconic acid During acid combination, more preferable result is can obtain with reference to the etching solution described herein based on manganese.Propylene carbonate is independent It is used together using or with wetting agent and the good etching period sticked together with shortening is provided, but in etching, activation and follow-up plating After applying, because ABS/PC admixtures have the tendency of to produce indenture, therefore bad order.In the pretreatment stage, by carbonic acid Propylene diester is applied in combination with these hydroxy acids can effectively avoid this problem.

Generally, the concentration of propylene carbonate is about 100 to about 500mL/L, and the concentration of the organic acid is about 100 to about 500mL/L.In addition, operation temperature is typically about 20 DEG C to 70 DEG C, and soak time is about 2 to about 10 minutes.

Therefore, the present invention further relates to a kind of pretreatment compositions for being used to that plastic base can be plated in general, includes γ-fourth Lactone or propylene carbonate, it is applied in combination with the organic hydroxy acids such as lactic acid, glycolic or gluconic acid.

Comparative example 5：

The test piece that the ABS/PC admixtures being made up of 45% makrolon are formed is immersed containing 150mL/L carbonic acid the third two In the solution of ester, soak time is as shown in table 1 with temperature.Hereafter, the plate is cleaned, and is containing 12.5M sulfuric acid and 0.08M manganese Solution in etch, wherein 0.015M manganese ion is manganese (III) by electrolytic oxidation.It is etched at a temperature of 68~70 DEG C Carry out 30 minutes.After handling herein, the plate is cleaned, (is illustrated in plastics pre-treatment sequence according to technical data, MacDermid D34 palladiums activator, MacDermid accelerators and MacDermid J64 electroless nickels) on using standard plating activate the plate, Then electroplated in copper.Check the decorative appearance of the plate, and left behind deposition from the substrate using Instron tensile testing machines Layer carries out quantitative adhesion test.What is obtained sticks together value as shown in table 1.

Table 1. sticks together value

The value of sticking together is quite changeable, and is plated find stain and indenture on part at this.Copper coating also has indenture.

Embodiment 8：

The experiment carried out in comparative example 5 is repeated, difference is that use includes 150mL/L propylene carbonates and 250mL/ The preconditioned agent of L 88% lactic acid solution.The result of these tests is as shown in table 2.

Table 2. sticks together value

Using this preconditioned agent comprising lactic acid, the uniformity sticked together is improved.After plating, decorative appearance pole is found It is good, and there is no stain and indenture.

Claims

1. a kind of electrolytic cell, comprising：

Electrolyte solution, it includes manganese (III) ion and manganese (II) ion being in the solution comprising sulfuric acid and additional acid, institute State additional acid and be selected from the group being made up of Loprazolam, methane-disulfonic acid and combinations thereof, wherein the manganese (III) ion shape Into metastable state complex compound；

Negative electrode, itself and the electrolyte solution contacts；With

Anode, itself and the electrolyte solution contacts.

2. electrolytic cell as claimed in claim 1, wherein the solution includes at least 8M sulfuric acid.

3. electrolytic cell as claimed in claim 2, wherein the solution includes at least 12M sulfuric acid.

4. electrolytic cell as claimed in claim 1, wherein the solution includes 1M to 6M Loprazolam or methane-disulfonic acid.

5. electrolytic cell as claimed in claim 1, wherein the solution includes 9 to 15 moles of sulfuric acid, and 1M to 6M first Alkyl sulfonic acid.

6. electrolytic cell as claimed in claim 1, it is selected from wherein the anode includes by vitreous carbon, weaving carbon fiber, lead, lead In the group that alloy, platinized titanium, platinum, iridium/tantalum pentoxide, niobium, boron doped diamond and foregoing one or more combination are formed Material.

7. electrolytic cell as claimed in claim 6, wherein the anode includes lead or metal.

8. electrolytic cell as claimed in claim 6, wherein the anode includes reticulated vitreous carbon.

9. electrolytic cell as claimed in claim 1, wherein the negative electrode include be selected from by platinum, platinized titanium, iridium/tantalum pentoxide, Material in the group that niobium and lead are formed.

10. electrolytic cell as claimed in claim 9, wherein the negative electrode includes lead.

11. electrolytic cell as claimed in claim 7, wherein the electrolytic cell also include be used to monitor in the solution manganese (II) from The device of sub- concentration.

12. electrolytic cell as claimed in claim 1, wherein the area of the anode is more than the area of the negative electrode.

13. the method that manganese (II) ion electrochemical is oxidized to manganese (III) ion by one kind, comprises the following steps：

Electrolyte is provided in electrolytic cell, manganese (II) ion that it is included in the solution at least one acid and additional acid is molten Liquid, the additional acid be selected from by Loprazolam, methane-disulfonic acid with and combinations thereof the group that is formed, wherein the electrolytic cell Including anode and negative electrode, wherein the anode and the negative electrode all contact with same electrolyte；

Apply electric current between the anode and the negative electrode；And

The electrolyte is aoxidized to form manganese (III) ion, wherein the manganese (III) ion forms metastable state complex compound.

14. method as claimed in claim 13, wherein at least one acid includes sulfuric acid solution.

15. method as claimed in claim 14, wherein at least one acid is at least 8M sulfuric acid comprising concentration.

16. method as claimed in claim 15, wherein the electrolyte includes at least 8M sulfuric acid and 1M to 6M methane Sulfonic acid.

17. method as claimed in claim 13, wherein the anode includes lead or metal.

18. method as claimed in claim 17, it is included in the step of accumulation that manganese (III) ion is monitored in the solution.

19. method as claimed in claim 18, manganese is oxidized to wherein no more than manganese (II) ion of original concentration 50% (III) ion.

20. method as claimed in claim 19, manganese is oxidized to wherein no more than manganese (II) ion of original concentration 25% (III) ion.

21. method as claimed in claim 18, wherein the accumulation of the manganese (III) ion is monitored using oxidation-reduction electrode, Wherein when the manganese (III) ion concentration reaches desired amount, stop electrolysis.

22. method as claimed in claim 18, wherein monitoring the tired of the manganese (III) ion by titrating the solution Product, wherein when the manganese (III) ion concentration reaches desired amount, stop electrolysis.

23. method as claimed in claim 13, being included in the electrolytic cell periodically makes electric current reverse, thus prevents two Manganese oxide is accumulated on the anode.

24. method as claimed in claim 13, in addition to plastics and the metastable state complex thereof can be plated for a period of time The step of so that plastics can be plated described in etching.

25. method as claimed in claim 24, wherein it is described plate plastics and the metastable state complex thereof before, institute Plastics can be plated by, which stating, contacts with pretreatment compositions to nurse one's health the surface appearance that can plate plastics, and the pretreatment compositions include The solvent selected from the group being made up of propylene carbonate, gamma-butyrolacton and combinations thereof.

26. method as claimed in claim 25, wherein the solvent includes propylene carbonate.

27. method as claimed in claim 25, wherein the pretreatment compositions also include organic hydroxy acids.

28. method as claimed in claim 27, wherein the organic hydroxy acids be selected from by lactic acid, glycolic, gluconic acid and The group that foregoing one or more combination is formed.

29. method as claimed in claim 18, wherein methods described also include monitoring the dense of manganese (II) ion in the solution Degree.

30. method as claimed in claim 27, wherein at a temperature of the pretreatment compositions maintain 20 to 70 DEG C, and The plastics that plate contact 2 to 10 minutes with the pretreatment compositions.

31. method as claimed in claim 13, wherein the manganese (II) ion is obtained from from by manganese sulfate, manganese carbonate and hydrogen-oxygen Change the compound selected in the group that manganese is formed.

32. method as claimed in claim 13, wherein the solution also includes colloidal silica manganese.

33. method as claimed in claim 13, wherein the concentration of the ion of manganese (II) described in the electrolyte is 0.005 mole To saturation.

34. method as claimed in claim 13, wherein the negative electrode include from by platinum, platinized titanium, iridium/tantalum pentoxide, niobium with And the material selected in the group that is formed of lead.

35. method as claimed in claim 34, wherein the negative electrode includes lead.

36. method as claimed in claim 34, wherein the negative electrode includes platinized titanium or platinum.

37. method as claimed in claim 13, wherein the current density of the anode is 0.1 to 0.4A/dm²。

38. method as claimed in claim 13, wherein the temperature of the electrolyte maintains 30 DEG C to 80 DEG C.

39. method as claimed in claim 13, wherein the electrolyte does not include any permanganate.

40. method as claimed in claim 24, wherein the plastic bag of plating contains acrylonitrile-butadiene-styrene (ABS) or propylene Nitrile-butadiene-styrene/makrolon.

41. a kind of method for etching plastic components, methods described is included by the plastic components and comprising manganese (III) ion and extremely Few a kind of sour solution contact, wherein the manganese (III) ion forms metastable state complex compound, and wherein described at least one acid Include Loprazolam or methane-disulfonic acid.

42. method as claimed in claim 41, wherein at least one acid also includes sulfuric acid.

43. method as claimed in claim 41, wherein the acid solution includes at least 8M sulfuric acid and 1M to 6M methane Sulfonic acid.

44. method as claimed in claim 41, wherein the plastic components includes acrylonitrile-butadiene-styrene (ABS).

45. method as claimed in claim 41, wherein the manganese (III) ion is the electrolytic oxidation by manganese (II) and in institute Caused by stating in solution.

46. method as claimed in claim 45, wherein the anode in the solution occurs for the electrolytic oxidation, and it is described Anode includes vitreous carbon, weaving carbon fiber, lead or metal.

47. method as claimed in claim 46, wherein the anode includes reticulated vitreous carbon.

48. method as claimed in claim 41, wherein in the plastic components with including manganese (III) ion and at least one acid The solution contact before, the plastic components is contacted with pretreatment compositions to nurse one's health the surface shape of the plastic components Condition, the pretreatment compositions are molten comprising being selected from the group being made up of propylene carbonate, gamma-butyrolacton and combinations thereof Agent.

49. method as claimed in claim 48, wherein the solvent includes propylene carbonate.

50. method as claimed in claim 48, wherein the pretreatment compositions also include organic hydroxy acids.

51. method as claimed in claim 50, wherein the organic hydroxy acids be selected from by lactic acid, glycolic, gluconic acid and The group that foregoing one or more combination is formed.

52. method as claimed in claim 50, wherein the pretreatment compositions include 100 to 500mL/L carbonic acid the third two Ester and 100 to the 500mL/L organic hydroxy acids.