CN114829672A - Avoiding unwanted plating on stent coatings for electrodeposition - Google Patents

Abstract

The present invention relates to a support for supporting parts to be plated in a chromic acid-free plating process, the support having a contact surface comprising an iodine-treated and/or bromine-treated plastic.

Description

Avoid unwanted plating on stent coatings for electrodeposition

The present invention relates to a support for supporting parts to be plated in a chromic acid-free plating process, a plating device for use in a chromic-free plating process, and a process for supporting parts to be plated in a chromic-free plating process. A method for a support of a component to be coated in a chromic acid plating process, a process for coating a component and the use of iodine and/or bromine pretreatment on a support for supporting a component to be coated.

Plastic Plating (POP) is a technology that has widespread applications in fields such as the automotive industry and shower and bathroom fittings. The most common substrate used for plating is a copolymer of acrylonitrile, styrene and butadiene known as ABS. This is a biphasic plastic consisting of a hard phase of acrylonitrile/styrene copolymer and a softer phase consisting of polybutadiene. Sometimes ABS polymers are combined with a percentage of polycarbonate to make ABS/PC. In order to plate these components, they are mounted on metal brackets to deliver the plating current to the components after the initial metallization stage. Metal-plated stents are coated with a PVC plastisol coating to avoid plating the entire stent.

The plating process for ABS involves a stage of etching the plastic to roughen the surface so that the surface provides good adhesion during subsequent plating stages, and the surface is sufficiently hydrophilic to wet completely when immersed in an aqueous solution. wet. After the etching stage, the non-conductive ABS initially needs to be metallized with a thin layer of nickel or copper in order to make it conductive for subsequent plating operations. This is accomplished by dipping the plated stent holding the ABS part into an aqueous solution of catalyst (usually palladium colloid), which deposits a thin layer of catalyst on the plastic surface. This is then used as a catalyst for the electroless nickel or copper plating process, which produces a thin metal layer on the ABS part. Aqueous solutions of such catalysts are referred to as activator solutions, and plastic surfaces treated in such baths are referred to as "activated" surfaces.

The initial etch stage used to coat ABS is usually a solution of chromic and sulfuric acid, which (primarily) oxidizes the polybutadiene phase of ABS to produce the necessary plastic roughening. The chromic acid solution is highly permeable, and a portion of it is adsorbed by the PVC plastisol material of the stent coating. After subsequent immersion in colloidal palladium, a portion of the colloid adhered to the PVC plastisol, but was inactivated by the adsorbed chromic acid. Therefore, when the stent holding the ABS part is immersed in an electroless nickel or copper plating solution, the catalyst adsorbed on the ABS part catalyzes the deposition of copper or nickel onto the part, but because of the presence of chromium on the PVC plastisol on the stent coating acid, so no nickel or copper deposits on the stent coating.

Chromic acid is a Group 1 carcinogen and faces increasing legislative pressure. Chromic acid is being phased out in Europe. Currently, chromic acid can only be used in some authorized applications, and even this limited use may be further restricted to the point of obsolescence.

Recently, a new way of etching ABS plastic has been developed using a combination of acid and manganese(III) ions (see, eg, US9534306B2 and US10260000B2 to Pearson, the appendices of these patents are hereby incorporated by reference). However, manganese-based etching is not effective enough to inhibit palladium colloids adhering to PVC plastisol coatings to prevent nickel or copper deposition during the chemical deposition stage of the POP process. Several patents have been generated detailing compounds that can be used to treat PVC stent coatings to avoid this problem (eg, EP3059277B1 to Noffke, US9506150B2 to Weitershaus, US9181622B2 to Middeke, and applications US2015233011A1 to Herdman and US2019112712A1 to Dalbin, The annexes to these patents are hereby incorporated by reference). Most of the compounds currently in use are organosulfur compounds. Although these compounds are effective in preventing nickel or copper deposition during the electroless plating stage, they can cause unexpected problems during the electroplating stage. The problem is that even though there is no detectable nickel or copper on the PVC plastisol coating after immersion in the chemical process, the bracket is then covered with copper during the acid copper plating stage after the initial metallization of the ABS part. Without wishing to be bound by theory, it is thought that this is most likely due to the reaction of copper ions with adsorbed organosulfur compounds on the PVC coating resulting in the formation of copper sulfide. This is a p-type semiconductor with high specific conductivity, and without being bound by theory, it is believed that this is the main reason why plated supports tend to be covered with copper. Therefore, there is a need for an improved method for inhibiting plating on PVC stent coatings during plating of ABS and ABS/PC when using processing techniques that do not involve the use of chromic acid.

WO2015/150156A1 relates to a composition and process for metallizing non-conductive plastic surfaces. WO2013/135862A2 relates to a process for metallizing non-conductive plastic surfaces. The process of both documents uses an iodate (IO ₃ ⁻ ) solution to pretreat the plated stents. Since the reducing agent is not present in the solution, the iodate ion remains as the iodate ion and does not form iodine, ie _I2- . The effect of such pretreatment is described as leading to "special protection of the plastic shell of the stent from metal deposits". One problem with this type of process is that it is impossible to confirm whether the stent has been pretreated because there is no visual change in the stent after pretreatment. Therefore, a pretreatment step must be performed each time a deposition process is performed, or alternatively accept the risk that the pretreatment has not been performed or that the pretreatment has worn out/became ineffective.

The present invention seeks to address at least some of the problems associated with the prior art or at least to provide a commercially acceptable alternative to the prior art. Specifically, the present invention aims to provide an improved support for use in a chromic acid-free plating process.

In a first aspect, the present invention provides a support for supporting a component to be plated in a chromic acid-free plating process, the support having a contact surface comprising iodine-treated and/or bromine-treated plastic.

The inventors have surprisingly found that during the chromate-free plating process, when the component is mounted on the support, substantially no copper or nickel may be deposited on the support during the chemical deposition stage, and during the subsequent electroplating stage There may also be substantially no deposits on the support. Without being bound by theory, in contrast to the organosulfur treated supports, it is believed that the contact surfaces of the supports of the present invention are not significantly activated such that the contact surfaces are not plated in the acid copper plating process.

While iodate-treated plastics have been described in the prior art as being resistant to metal deposition, surprisingly, iodine- and/or bromine-treated plastics also exhibit this effect. This is because the chemistry of iodate and iodine is very different - iodate is an ionic species (IO ₃ ⁻ ), containing a combination of an iodine atom in the +5 oxidation state with an oxygen atom, whereas iodine is a covalent species (I ₂ ), containing only iodine atoms in elemental state (oxidation state zero).

Each aspect or embodiment as defined herein may be combined with any other aspect or embodiment unless expressly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature indicated as being preferred or advantageous.

When introducing elements of the present disclosure or the preferred embodiments thereof, the supporting articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. The term "consisting of" is intended to mean that there cannot be other elements other than the listed elements. The term "consisting essentially of" is intended to mean that no other elements than the listed elements may be present unless the other elements would not materially affect the essential and novel characteristics of the invention.

The support is used in a chromic acid-free plating process, preferably in a plastic plating ("POP") process. The plating process is substantially free of chromic acid, particularly during the etching step of the plating process.

The contact surface of the support is the (outer) surface that comes into contact with the etching and plating solutions during typical processing processes. Typically, substantially the entire contact surface of the support includes iodine-treated and/or bromine-treated plastic, more typically, the entire contact surface of the support includes iodine-treated and/or bromine-treated plastic.

The contact surface of the support comprises (or consists essentially of or consists of) iodine-treated and/or bromine-treated plastic. "Treatment" means that the plastic contains iodine and/or bromine, typically by contact with a solution of iodine and/or bromine (ie, _I2 and/or Br2 ₎ . Without being bound by theory, it is believed that iodine and/or bromine (ie, _I2 and/or Br2 ₎ impregnate into the surface of the plastic as a result of this contact. In other words, the iodine-treated and/or bromine-treated plastics may be iodine-impregnated and/or bromine-impregnated plastics, respectively (ie, molecular iodine/ _I2 -impregnated and/or molecular bromine/Br2 _- impregnated plastics). The impregnation of iodine and/or bromine into the plastic can be observed by the color change of the plastic, the iodine impregnated plastic is usually brown and the bromine impregnated plastic is usually orange. Because the use of iodine and/or bromine changes the color of the plastic, the present invention may enable the user to identify whether the plastic has been treated compared to using an iodate solution in conventional processes. Over time and/or prolonged use, the effect of the iodine and/or bromine treatment may diminish, and the color of the plastic may change accordingly, allowing the operator to identify when further treatment of the support may be required.

Contact surfaces include iodine-treated and/or bromine-treated plastics. The contact surface preferably comprises iodine-treated plastic. While bromine is still effective, bromine is not as persistent as iodine on the surface of plastics.

The plastic preferably comprises PVC, more preferably comprises (or consists essentially of or consists of) a PVC plastisol. PVC or polyvinyl chloride is produced by the polymerization of vinyl chloride monomers. A PVC plastisol consists of a suspension of PVC particles in a liquid plasticizer. Iodine and/or bromine treatment of such materials can be particularly effective in inhibiting plating on such materials during electroless plating and/or electroplating.

The support preferably comprises metal at least partially coated with plastic. The presence of metal may enable plating current to be delivered to the component supported by the support during the electroplating process. Metals preferably include copper and/or iron alloys. Metals can act as electrodes (cathode or anode) during the electroplating process. In particular, the supports used to hold the components are often made of metal in order to transmit electrical current to the components during electroplating. The components are generally held in place on the support by spring contacts or clamps (hereinafter referred to as support clamps). In order to carry electrical current, these support fixtures necessarily have small uncoated areas so that electrical contact is maintained during machining of the part. The rest of the support is coated with an insulating plastic coating (usually PVC) in order to prevent the entire support from being electroplated. This coated surface is hereinafter referred to as the support contact surface. Typically, the portion of the support that is in contact with the power source to supply the electroplating current (usually on top of the support) is not coated because this portion is not immersed in the processing solution.

The support preferably comprises a plated stent. Plating supports are particularly suitable for supporting one or more components during the plating process. Suitable shapes and configurations for stents are known in the art. The brackets may include, for example, one or more hooks or support clamps to support the components during the plating process. The stent may include cathodes and/or anodes used in electroplating processes.

In another aspect, the present invention includes a plating apparatus for use in a chromic acid-free plating process, the plating apparatus including a plating vessel having one or more for supporting a component to be plated The one or more supports have contact surfaces comprising iodine-treated and/or bromine-treated plastics.

For the avoidance of doubt, the advantages and preferred features of the other aspects of the invention also apply to this aspect.

The support can be a support as described herein.

The plating vessel is generally of a suitable shape and suitable size to accommodate the parts to be plated during the plating process. Such plated containers are known in the art. The inner surfaces (ie, the contact surfaces) of the container are generally substantially inert to the etching solutions and plating solutions used in the plating process.

In another aspect, the present invention provides a method of processing a support for supporting a component to be plated in a chromate-free plating process, the support having a contact surface, the contact surface comprising a plastic, the method comprising :

providing a support for supporting a component to be plated in a chromate-free plating process, the support having a contact surface, the contact surface comprising plastic;

providing an aqueous solution comprising one or both of iodine and bromine; and

At least a portion of the plastic of the contact surface of the support is brought into contact with the aqueous solution.

For the avoidance of doubt, the advantages and preferred features of the other aspects of the invention also apply to this aspect.

Similar to the first aspect, when the support is used during the chromate-free plating process, substantially no copper or nickel may be deposited on the support during the subsequent chemical deposition stage, and also on the support during the subsequent electroplating stage. Substantially no deposits may be possible.

This treatment can result in the support described herein. The support may comprise, for example, a plated stent.

The plastic contact surface of the support can be in contact with the components to be plated during plating, and can be in contact with the etching and/or plating solutions used in the plating process.

The aqueous solution contains one or both of iodine and bromine (ie, molecular iodine ( _I2 ) and molecular bromine (Br2 ₎ ).

Contacting at least a portion of the plastic of the contact surface of the support with the aqueous solution typically includes at least partially immersing the support in the aqueous solution, and more typically fully immersing the support in the aqueous solution.

The contacting can be carried out, for example, at a temperature between ambient temperature and 100°C. Since ambient temperature is sufficient to perform, it is preferred to perform the method at ambient temperature in order to reduce cost and improve safety.

The aqueous solution preferably contains iodine. While bromine is still effective, bromine is not as persistent as iodine on the surface of plastics.

The aqueous solution preferably contains, but is not limited to, 0.005M to 0.1M iodine, more preferably 0.01M to 0.05M iodine. The use of such iodine concentrations is particularly effective in suppressing plating on the support during the plating process.

The aqueous solution preferably contains iodide ions. Iodine (I ₂ ) is not particularly soluble in water. The presence of iodide ions can increase the solubility of iodine in aqueous solutions. For example, the presence of iodide ions may allow the formation of aqueous solutions containing up to 12% iodine. The iodide can be introduced into the aqueous solution, for example, in the form of potassium iodide.

The molar ratio of iodide ions to iodine in the aqueous solution is preferably at least 1:1, more preferably at least 1.5:1, even more preferably at least 2:1. Such ratios enable the aqueous solution to advantageously contain substantial amounts of iodine.

Alternatively, other suitable means of increasing the solubility of iodine may be employed, such as the introduction of an effective amount of a co-solvent to dissolve the desired concentration of iodine. Suitable solvents are many and can include, but are not limited to, alcohols, glycols, and alkylene carbonates.

The step of providing the aqueous solution preferably includes contacting iodide ions with iodate ions in the aqueous solution. From a commercial point of view, it is undesirable to dissolve iodine in, for example, potassium iodide solution in order to provide both iodine and iodide ions in aqueous solution. Advantageously, contacting iodide ions with iodate ions results in the in situ generation of iodine according to the following chemical reaction:

IO ₃ ^- +5I ^- +6H ⁺ →3H ₂ O+3I ₂

As an alternative to iodate ions, other oxidizing agents capable of oxidizing iodide ions to iodine can be used; for example, persulfate ions, nitrate ions, or hydrogen peroxide can be used. The present invention is not limited by the type of oxidizing agent used to oxidize iodide ions to iodine. Iodide ions preferably generally exceed the oxidizing agent.

When the aqueous solution contains bromine, the corresponding bromate/bromide reaction can also be used to generate bromine in situ.

The support is preferably contacted with the aqueous solution for at least 10 seconds, more preferably for at least 30 seconds, even more preferably for 1 to 10 minutes, still even more preferably for 1 to 5 minutes. Such contact times can result in the support being particularly resistant to plating. Longer contact times may result in only negligible improvements in plating resistance.

The plastic of the contact surface of the support preferably comprises PVC, more preferably comprises (or consists essentially of or consists of) PVC plastisol. Iodine and/or bromine treatment of such materials can be particularly effective in inhibiting plating on such materials during electroless plating and/or electroplating.

The plating process preferably includes plating on ABS polymer and/or ABS/PC polymer. Such plating processes are particularly susceptible to plating on other plastic supports used in the process, such as plastic supports. ABS or "Acrylonitrile Butadiene Styrene" has the _formula ( _C8H8 ) _{x ·} ( _C4H6 ) _{y ·} ( _C3H3N ) _z ) and is a common thermoplastic polymer known in the art. ABS/PC includes a blend of acrylonitrile butadiene styrene and polycarbonate.

In another aspect, the present invention provides a method of manufacturing the support described herein, the method comprising the processing method described herein.

For the avoidance of doubt, the advantages and preferred features of the other aspects of the invention also apply to this aspect.

In another aspect, the present invention provides a process for plating a component, the process comprising:

providing a part to be plated, the part having an outer surface comprising plastic;

A plating apparatus is provided, the plating apparatus including a plating vessel having one or more supports for supporting a component to be plated, the one or more supports having a contact surface comprising Iodine-treated and/or bromine-treated plastics;

Mount the component on the support of the plating unit to provide the component mounted;

contacting at least a portion of the plastic of the outer surface of the mounted component with an electrolyte that is substantially free of chromic acid to at least partially etch the plastic to form an etched surface of the component;

contacting at least a portion of the etched surface of the component with the activator solution to form an activated surface of the component; and

At least a portion of the activated surface of the part is contacted with an electroless nickel plating solution or an electroless copper plating solution to form a plated surface of the part.

For the avoidance of doubt, the advantages and preferred features of the other aspects of the invention also apply to this aspect.

The plating apparatus may include a plating apparatus as described herein. The support may comprise a support as described herein.

A "pre-etch" step may be performed before at least a portion of the plastic of the outer surface of the mounted component is brought into contact with the electrolyte. This may involve, for example, contacting at least a portion of the plastic of the outer surface of the installed component with an aqueous solvent blend containing propylene carbonate and butyrolactone. Such pre-etching steps are not always required, but such pre-etching steps can alter the plastic surface, making it easier to etch.

Suitable chromic acid-free electrolytes are known in the art. Contacting at least a portion of the plastic of the outer surface of the mounted component with the electrolyte preferably includes at least partially immersing the mounted component in the electrolyte, more preferably fully immersing the mounted component in the electrolyte. Contacting can be carried out at room temperature. However, the contacting is preferably carried out at elevated temperature, eg above ambient temperature, more preferably above 30°C, even more preferably above 50°C, still even more preferably above 60°C. Such high temperatures can help provide suitable etch levels. In order to avoid loss of electrolyte, the contacting is preferably carried out at a temperature below 100°C, more preferably below 90°C, even more preferably below 80°C. The contacting is preferably carried out for at least 30 seconds, more preferably for at least one minute, even more preferably for at least 5 minutes, still even more preferably for 1 to 30 minutes, still even more preferably for 5 to 20 minutes. Such contact times can provide suitable etch levels.

Suitable activator solutions are known in the art. Contacting at least a portion of the etched surface of the component with the activator solution preferably includes at least partially immersing the etched component in the activator solution, more preferably fully immersing the etched component in the activator solution. Although elevated temperatures can be used, the contacting is usually carried out at ambient temperature. The contacting is preferably carried out for at least 30 seconds, more preferably for at least one minute, even more preferably for 1 minute to 20 minutes, still even more preferably for 1 minute to 10 minutes.

The etched surface may be contacted with an acid (eg, hydrochloric acid) prior to contacting at least a portion of the etched surface of the component with the activator solution. This is because typical activators include colloids that sometimes exhibit limited stability in water. If the wet plastic surface is immersed directly in the colloid solution, the colloid at the plastic surface may become unstable.

Suitable electroless nickel and electroless copper plating solutions are known in the art. Typical chemical solutions include ions of nickel or copper together with a reducing agent such as, for example, a hypophosphite reducing agent. Contacting at least a portion of the activated surface of the part with the electroless nickel or electroless copper plating solution preferably comprises at least partially immersing the activated part in the electroless nickel or electroless copper plating solution, more preferably the activated part The parts are completely immersed in electroless nickel solution or electroless copper solution.

After contact with the electrolyte and/or activator solution and/or electroless nickel and/or electroless copper plating solution and before the next step, the part is typically rinsed, more typically in water.

Components can generally include any plastic components that need to be plated. Examples include automotive supports (such as car grilles, headlamp surrounds, door handles, and trim), shower fitting supports, bathroom fitting supports, home and furniture accessories, and electronic components (such as cameras, computers, Telephone).

The iodine-treated and/or bromine-treated plastic preferably comprises PVC, more preferably a PVC plastisol (or consists essentially of or consists of, in addition to iodine and/or bromine).

The plastic of the outer surface of the part preferably comprises (or consists essentially of or consists of) ABS and/or ABS/PC.

The etching electrolyte may be any suitable etching electrolyte that is substantially free of chromium (VI) and may contain, for example, permanganate ions or other strong oxidizing agents. Preferred electrolytes preferably contain manganese(III) ions in a solution of 9 to 15 molar sulfuric or phosphoric acid. Such electrolytes are particularly effective at etching plastics without the use of chromic acid.

The activator solution preferably contains precious metal colloids. More preferably, the precious metal colloid comprises a first core metal and a second colloidal metal colloidally surrounding the core; the core metal comprises at least one metal selected from silver, platinum, palladium and nickel, with palladium being particularly preferred; and The dicolloidal metal includes at least one metal selected from the group consisting of tin and lead, with tin being particularly preferred. The core metal can catalytically activate the deposition of electroless copper or electroless nickel. Such activator solutions are particularly effective in promoting nickel or copper deposition in subsequent electroless plating steps. An example of a suitable commercially available activator is Evolve Activator from MacDermidEnthone.

After contacting at least a portion of the etched surface of the component with the activator solution, at least a portion of the etched surface can be contacted with the accelerating solution. This can be used to remove colloidal metal from the core catalytic metal, which might otherwise be shielded and potentially ineffective. In other words, the activator post-treatment removes the second colloidal metal from the activated surface, thereby exposing the first core metal and enabling the catalytic function. Suitable accelerating solutions are known in the art. The composition of the accelerating solution can vary widely and can be acidic or basic. Preferably, the accelerating solution is acidic and may, for example, contain chloride ions in combination with organic and inorganic acids. An example of a suitable commercially available accelerator is Evolve Accelerator from MacDermid Enthone.

Contacting at least a portion of the etched surface of the component with the accelerator solution preferably includes at least partially immersing the etched and activated component in the accelerator solution, more preferably fully immersing the etched and activated component in the accelerator solution. Contacting is typically performed at elevated temperatures (eg, 50°C), although ambient temperature or higher may be used. The contacting is preferably carried out for at least 30 seconds, more preferably for at least one minute, even more preferably for 1 minute to 20 minutes, still even more preferably for 1 minute to 10 minutes.

In a preferred embodiment, the process further comprises electroplating the plated surface of the component, wherein the support comprises a metal at least partially coated with an iodine-treated and/or bromine-treated plastic. As mentioned above, the presence of metal may enable plating current to be delivered to the component during the electroplating process. Electroplating preferably includes copper electroplating.

In another aspect, the present invention provides a component plated according to the process described herein.

For the avoidance of doubt, the advantages and preferred features of the other aspects of the invention also apply to this aspect.

In another aspect, the present invention provides the use of a pretreatment with iodine and/or bromine on a support for supporting a component to be plated, the use for suppressing the support on a support during a chromic acid-free plating process plated, the support has a contact surface comprising plastic.

For the avoidance of doubt, the advantages and preferred features of the other aspects of the invention also apply to this aspect.

The invention will now be described with reference to the following non-limiting drawings, in which:

Figure 1 shows a schematic view of an example of a support according to the invention.

Figure 2 shows a cross-section of a portion of the support of Figure 1 along line A-B.

Figure 3 shows a schematic diagram of an example of a coating apparatus according to the invention.

Figure 4 shows a flow chart of an example of a method according to the invention.

Figure 5 shows a flow diagram of an example of a process according to the present invention.

Referring to Figures 1-3, an example of a support (coated stent) 1 for use in a chromic acid-free coating process according to the present invention is depicted. The bracket comprises a plurality of hooks or support fixtures 2 to which the components to be plated can be mounted during the plating process. The support has a contact surface comprising an iodine- and/or bromine-treated plastic 3 . The interior of the support may include metal 4 . At least a portion of the metal 4 supporting the jig 2 is not coated with the iodine-treated and/or bromine-treated plastic 3 so that electrical current can be transmitted to the part during plating. Figure 3 shows a coating device 5 used in a chromic acid-free coating process, the coating device 5 comprising a coating vessel 6 having one or more supports 1, the one or more supports Has a contact surface comprising iodine-treated and/or bromine-treated plastic 3 .

Referring to Figure 4, there is shown a method 7 of processing a support for supporting a component to be plated in a chromic acid-free plating process, the support having a contact surface comprising a plastic, the method comprising:

i. providing a support for supporting the part to be plated in the chromate-free plating process, the support having a contact surface comprising plastic;

ii. providing an aqueous solution comprising one or both of iodine and bromine; and

ii. Contacting at least a portion of the plastic of the contact surface of the support with the aqueous solution.

Referring to Figure 5, there is shown a process 8 for plating a component including:

a. providing the part to be plated, the part having an outer surface comprising plastic;

b. providing a plating apparatus comprising a plating vessel having one or more supports for supporting the part to be plated, the one or more supports having a contact surface, the contact Surfaces include iodine-treated and/or bromine-treated plastics;

c. Mount the component on the support of the plating unit to provide the component mounted;

d. contacting at least a portion of the plastic of the outer surface of the mounted component with an electrolyte that is substantially free of chromic acid to at least partially etch the plastic to form an etched surface of the component;

e. contacting at least a portion of the etched surface of the component with the activator solution to form the activated surface of the component; and

f. Contacting at least a portion of the activated surface of the part with an electroless nickel plating solution or an electroless copper plating solution to form a plated surface of the part.

The process optionally further includes:

g. The plated surface of the electroplated part, and wherein the support comprises a metal at least partially coated with an iodine-treated and/or bromine-treated plastic.

The invention will now be described with reference to the following non-limiting examples. All examples used the same PVC plastisol coating.

Example 1 (comparative example)

Plated stents with PVC plastisol coating were processed in the following order (rinse stage omitted for brevity):

1. Immerse in an aqueous solvent blend containing 100ml/l propylene carbonate and 50ml/l butyrolactone for 3 minutes at 35°C

2. Etching in chrome-free etchant (Evolve Etch from MacDermidEnthone) based on the teachings of patent US10260000B2 at 68°C for 10 minutes

3. Immerse in a 30% solution of 35 wt/wt% hydrochloric acid for 30 seconds at ambient temperature

4. Immerse in a proprietary palladium colloid solution (Evolve Activator from MacDermid Enthone) for 3 minutes at ambient temperature.

5. Immerse in a proprietary acceleration solution (Evolve Accelerator 800 from MacDermid Enthone) for 2 minutes at 50°C

6. Immerse in electroless nickel plating solution (Evolve EN-60 from MacDermid Enthone) for 7 minutes at ambient temperature

After this treatment, the entire plated stent was covered with a coating of nickel.

Example 2 (comparative example)

Plated stents with PVC plastisol coating were processed in the following order (rinse stage omitted for brevity):

1. Immerse in a solution containing 10g/l thiourea and keep at 70°C for 10 minutes

2. Immerse in an aqueous solvent blend containing 100ml/l propylene carbonate and 50ml/l butyrolactone for 3 minutes at 35°C

3. Based on the teachings of patent US10260000B2, etched in chrome-free etchant (Evolve Etch from MacDermidEnthone) for 10 minutes at 68°C 4. Immersion in 30% solution of 35 wt/wt% hydrochloric acid at ambient temperature hold for 30 seconds

5. Immerse in a proprietary palladium colloid solution (Evolve Activator from MacDermid Enthone) for 3 minutes at ambient temperature.

6. Immerse in proprietary acceleration solution (Evolve Accelerator 800 from MacDermid Enthone) for 2 minutes at 50°C

7. Immerse in electroless nickel plating solution (Evolve EN-60 from MacDermid Enthone) for 7 minutes at ambient temperature

8. Plating in acid copper electrolyte at a current density of 2Adm ^-2 for 40 minutes at ambient temperature

It was observed that after stage 6, no nickel coating was observed on the stent, but after stage 7 there was a significant amount of copper plating on the PVC plastisol coating.

Example 3

Plated stents with PVC plastisol coating were processed in the following order (rinse stage omitted for brevity):

1. Immerse in a solution containing 0.05M iodine for 5 minutes at ambient temperature

2. Immerse in an aqueous solvent blend containing 100ml/l propylene carbonate and 50ml/l butyrolactone for 3 minutes at 35°C

3. Etch in chrome free etchant (Evolve Etch from MacDermidEnthone) based on the teachings of patent US10260000B2 at 68°C for 10 minutes

4. Immerse in a 30% solution of 35 wt/wt% hydrochloric acid for 30 seconds at ambient temperature

5. Immerse in a proprietary palladium colloid solution (Evolve Activator from MacDermid Enthone) for 3 minutes at ambient temperature.

6. Immerse in proprietary acceleration solution (Evolve Accelerator 800 from MacDermid Enthone) for 2 minutes at 50°C

7. Immerse in electroless nickel plating solution (Evolve EN-60 from MacDermid Enthone) for 7 minutes at ambient temperature

8. Plating in acid copper electrolyte at a current density of 2Adm ^-2 for 40 minutes at ambient temperature

In this order, no nickel coating or copper coating was observed after treatment. Repeat this sequence for another 4 cycles, but omit step 1. No plating on the PVC plastisol was observed during these cycles. It was confirmed that the iodine was not altered to form iodate ions in either the etching bath or the treatment steps.

Example 4

Plated stents with PVC plastisol coating were processed in the following order (rinse stage omitted for brevity):

1. Immerse in a solution containing 0.01M iodine for 5 minutes at ambient temperature

2. Immerse in an aqueous solvent blend containing 100ml/l propylene carbonate and 50ml/l butyrolactone for 3 minutes at 35°C

3. Etch in chrome free etchant (Evolve Etch from MacDermidEnthone) based on the teachings of patent US10260000B2 at 68°C for 10 minutes

4. Immerse in a 30% solution of 35 wt/wt% hydrochloric acid for 30 seconds at ambient temperature

5. Immerse in a proprietary palladium colloid solution (Evolve Activator from MacDermid Enthone) for 3 minutes at ambient temperature.

6. Immerse in proprietary acceleration solution (Evolve Accelerator 800 from MacDermid Enthone) for 2 minutes at 50°C

7. Immerse in electroless nickel plating solution (Evolve EN-60 from MacDermid Enthone) for 7 minutes at ambient temperature

8. Plating in acid copper electrolyte at a current density of 2Adm ^-2 for 40 minutes at ambient temperature

In this order, no nickel coating or copper coating was observed after treatment. Repeat this sequence for another 2 loops, but omit step 1. No plating on the PVC plastisol was observed during these cycles. It was confirmed that the iodine was not altered to form iodate ions in either the etching bath or the treatment steps.

Example 5 (comparative example)

Two plated stents with different PVC plastisol coatings were immersed in potassium iodate (30 g/l) solution for 20 min at 70°C. No color change was observed in either of the stent-coated PVC plastisols. This is consistent with the colorless nature of potassium iodate solutions.

The foregoing detailed description has been presented by way of explanation and illustration, and is not intended to limit the scope of the appended claims. Many modifications to the preferred embodiments of the invention shown herein will be apparent to those skilled in the art and still fall within the scope of the appended claims and their equivalents.

Claims (20)

Claims 1. A support for supporting a component to be plated in a chromic-free plating process, the support having a contact surface comprising an iodine-treated and/or bromine-treated plastic. 2. The support of claim 1, wherein the contact surface comprises an iodine-treated plastic. 3. A support according to claim 1 or claim 2, wherein the plastic comprises PVC, preferably PVC plastisol. 4. A support according to any preceding claim, wherein the support comprises metal at least partially coated with the plastic. 5. A plating apparatus for use in a chromic acid-free plating process, the plating apparatus comprising a plating vessel having one or more supports for supporting a component to be plated, The one or more supports have contact surfaces comprising iodine-treated and/or bromine-treated plastics. 6. A method of processing a support for supporting a component to be plated in a chromate-free plating process, the support having a contact surface, the contact surface comprising a plastic, the method comprising: providing a support for supporting a component to be plated in a chromate-free plating process, the support having a contact surface, the contact surface comprising plastic; providing an aqueous solution comprising one or both of iodine and bromine; and At least a portion of the plastic of the contact surface of the support is brought into contact with the aqueous solution. 7. The method of claim 6, wherein the aqueous solution comprises iodine. 8. The method according to claim 7, wherein the aqueous solution comprises 0.005M to 0.1M iodine, preferably 0.01M to 0.05M iodine. 9. The method of claim 7 or claim 8, wherein the aqueous solution comprises iodide ions. 10. The method of claim 8, wherein the molar ratio of iodide ion to iodine is at least 1:1. 11. The method of any one of claims 7 to 10, wherein the step of providing the aqueous solution comprises contacting iodide ions in an aqueous solution with an oxidizing agent selected from the group consisting of iodate ions, persulfate ions , nitrate ions, hydrogen peroxide, and combinations of two or more thereof, preferably wherein the oxidizing agent comprises iodate ions. 12. The method of any one of claims 6 to 11, wherein the support is contacted with the aqueous solution for at least 10 seconds, preferably for at least 30 seconds, more preferably for 1 to 10 minutes, even more preferably ground contact for 1 to 5 minutes. 13. The method of any one of claims 6 to 12, wherein the plastic of the contact surface of the support comprises PVC, preferably PVC plastisol. 14. The method of any one of claims 6 to 13, wherein the plating process comprises plating on ABS polymer and/or ABS/PC polymer. 15. A method of manufacturing a support according to any one of claims 1 to 4, the method comprising the method according to any one of claims 6 to 14. 16. A process for plating a component, the process comprising: providing a part to be plated, the part having an outer surface, the outer surface comprising plastic; A plating apparatus is provided, the plating apparatus including a plating vessel having one or more supports for supporting a component to be plated, the one or more supports having a contact surface, the said contact surfaces include iodine-treated and/or bromine-treated plastics; mounting the component on a support of the plating apparatus to provide a mounted component; contacting at least a portion of the plastic of the outer surface of the mounted component with an electrolyte that is substantially free of chromic acid to at least partially etch the plastic to form an etched surface of the component ; contacting at least a portion of the etched surface of the component with an activator solution to form an activated surface of the component; and At least a portion of the activated surface of the part is contacted with an electroless nickel plating solution or an electroless copper plating solution to form a plated surface of the part. 17. The process of claim 16, wherein: The iodine-treated and/or bromine-treated plastic comprises PVC, preferably a PVC plastisol; and/or The plastic of the outer surface of the part comprises ABS and/or ABS/PC. 18. The process of claim 16 or claim 17, wherein: The electrolyte comprises manganese(III) ions in a solution of 9 molar to 15 molar sulfuric or phosphoric acid; and/or The activator solution comprises a precious metal colloid, preferably wherein the precious metal colloid comprises a first core metal and a colloidal metal colloidally surrounding the core; the core metal comprising at least one selected from the group consisting of silver, platinum, palladium and nickel. and the colloidal metal includes at least one metal selected from tin and lead. 19. The process of any one of claims 16 to 18, wherein the process further comprises electroplating the plated surface of the component, and wherein the support comprises at least partially coated with the iodine Metal treated and/or bromine treated plastic. 20. Use of a pretreatment with iodine and/or bromine on a support for supporting a component to be plated for inhibiting plating on said support during a chromic acid-free plating process, whereby The support has a contact surface comprising plastic.

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