KR20230054852A - Method for activating the surface of a non-conductive or carbon fiber-containing substrate for metallization - Google Patents

Abstract

The present invention relates to a method for treating the surface of a non-conductive or carbon fiber-containing substrate using a conditioning step, a selector treatment step and an activation step.

Description

Method for activating the surface of a non-conductive or carbon fiber-containing substrate for metallization

The present invention relates to the activation of the surface of a typically non-conductive or carbon fiber containing substrate for subsequent metallization.

In particular, the present invention relates to a method for activating the surface of a non-conductive or carbon fiber-containing substrate for metallization, a method for metallizing an activated surface of a non-conductive or carbon fiber-containing substrate, and a non-conductive or carbon fiber-containing substrate for metallization. A process for preparing an aqueous, palladium-free activating composition for activating the surface of a substrate, and an aqueous, palladium-free activating composition for activating the surface of a non-conductive or carbon fiber containing substrate for metallization.

Metallization of such substrates is usually of high commercial interest. In many aspects of daily life, these substrates are covered with structures or layers of metal, either for decorative or functional applications. For example, typically non-conductive plastic substrates are used to make sanitary articles with a shiny chrome layer. In addition, a large number of chrome-coated plastic substrates are used in the automotive industry.

Besides these decorative articles, functional metallization is essential for manufacturing printed circuit boards, for example. In these substrates, a laminate containing a non-conductive resin is usually used as a base material bearing the circuit of a copper wire.

Carbon fiber-containing substrates can be used, for example, in power-to-gas, power-to-fuel, and power-to-chemical applications, and in batteries. It has increasing potential as a catalytically active surface.

All these applications usually require multi-step fabrication of non-conductive or carbon fiber-containing substrates to make them receptive for subsequent metallization.

In a first step, cleaning of the surface of the normally non-conductive or carbon fiber-containing substrate is performed, for example to remove grease or impurities.

In a second step, typically conditioning (also referred to as pretreatment) of the surface is performed to make the surface receptive to subsequent activation. Such conditioning includes, for example, etching to create voids and enlarge the surface in some cases.

In the third step, critical activation is performed. In this activation, usually a very thin seed or activation layer is deposited/anchored onto the surface of the non-conductive or carbon fiber-containing substrate to serve as a starting point for the subsequent first metallization layer. As a result, an activated surface for metallization is obtained. A seed or activation layer generally serves as an intermediary between the surface of a non-conductive or carbon fiber-containing substrate and one or more subsequent metallization layers. Typically, the seed/activation layer is formed by depositing metal nanoparticles on the surface, for example from a colloidal activation composition.

In a fourth step, typically the first metallization layer is deposited over the seed/activation layer, most commonly by electroless plating. In some cases, such electroless plating involves immersion-type plating, ie, deposition of a nobler metal on the seed/activation layer by an exchange reaction and in the absence of a reducing agent. In other cases, it includes deposition of metals or metal alloys via autocatalytic deposition, which means deposition facilitated by a reducing agent.

In a fifth step, typically a second metallization layer is deposited over the first metallization layer, again either by autocatalytic deposition or by electrolytic deposition.

Basically, a person skilled in the art is familiar with this sequence of steps. Typically, in conventional colloidal activation compositions, noble metal nanoparticles are very often utilized as palladium nanoparticles. However, precious metals are generally expensive and wastewater treatment is very important to recycle the remaining precious metals. Alternatively, also less expensive metal ions are increasingly utilized in the respective activating compositions.

Another common disadvantage is that such activating compositions naturally undergo some form of decay or degradation. Typically, the nanoparticles aggregate and form insoluble, precipitated aggregates, rendering the composition largely unusable. Thus, it is typically desirable to stabilize the nanoparticles after they are formed through reduction of the respective metal ion. For this purpose, stabilizer compounds are generally used to modify the charge distribution of the particles, to limit the particle size, and/or to prevent oxidation of the particles. In many cases, polymers and/or antioxidants and/or metal ions (eg, tin ions) are used for these purposes.

For example, CN 107460459 A relates to a simple nano-copper activating liquid utilizing a stabilizer and a reducing agent to prevent aggregation and oxidation of the nanoparticles, respectively.

CN 109295442 A relates to a method for the production of an electroless copper-nickel bimetal layer, a method using colloidal copper activation.

US 4,278,712 discloses a process for the activation of weakly active colloidal dispersions useful in the manufacture of non-conductors prior to electroless plating. The method is based on the controlled oxidation of different weakly active colloids by treatment with suitable gases and/or chemicals, which results in said controlled oxidation. However, the presence of at least one colloidal stabilizer is mandatory. In this way, no reversible equilibrium is maintained.

These approaches, as described in the art, typically have the disadvantage that they are susceptible to aggregation and sedimentation sooner or later, mainly because the stabilizer compounds do not sufficiently stabilize the particles over time. As a result, product life is highly dependent on production date, delivery time and quality of stabilization.

In addition, these stabilizer compounds often appear to reduce the ability of the nanoparticles to effectively activate their respective surfaces. Additives appear to avoid aggregation - at least to some extent - on the one hand, but on the other hand prevent the fast and strong adsorption of these particles to the surface.

WO 2020/201387 A1 discloses a method for activating the surface of a non-conductive or carbon fiber-containing substrate for metallization and a respective activating composition, which on the one hand is simple and highly effective, and on the other hand in particular agglomerates and It is insensitive to precipitation and guarantees a long service life.

Metallized substrates prepared according to this process have been found to exhibit negligible performance in solder impact tests.

It is therefore an object of the present invention to provide a method for activating the surface of a non-conductive or carbon fiber-containing substrate for metallization and a respective activating composition, which on the one hand is simple and highly effective, and on the other hand particularly cohesive. and insensitive to precipitation to ensure a long service life. In addition, these methods and respective compositions must be inexpensive.

Another object of the present invention is to provide each method exhibiting excellent performance in a solder impact test.

Another object of the present invention is to provide each process with a reduced environmental burden, eg less sophisticated wastewater treatment and reduced effective concentrations of chemicals.

It is also an object of the present invention to provide a respective method with an increased lifetime, in particular for the active composition utilized.

Summary of the Invention

The above-mentioned object is solved by a method for treating the surface of a non-conductive or carbon fiber-containing substrate, the method comprising steps:

(I) conditioning the surface of the non-conductive or carbon fiber-containing substrate, the conditioning method comprising:

(a) providing the substrate;

(b) providing a conditioning composition comprising a nitrogen containing compound; and

(c) contacting the substrate with the conditioning composition.

Including, the step of conditioning;

(II) a step of subjecting the surface of the non-conductive or carbon fiber-containing substrate to a selector treatment, comprising:

(a) providing a substrate treated according to step (I);

(b) (i) contains a nitrogen-containing compound;

(ii) having a pH of 9 to 14

providing a selector composition; and

(c) contacting the substrate (substrate treated according to step (I)) with the selector composition.

Including, processing the selector; and

(III) activating the surface of the non-conductive or carbon fiber-containing substrate for metallization, wherein the activating method comprises:

(a) providing a substrate treated according to step (II);

(b) providing an aqueous, palladium-free activating composition;

(i) dissolved transition metal ions of the first type and further metal particles thereof;

(ii) one or more complexing agents, and

(iii) permanently or temporarily at least one reducing agent, and

(iv) optionally, one or more dissolved metal ions of a second species different from the first species.

including,

here

- at least one type of dissolved transition metal ion and its metal particles are in reversible equilibrium, provided that

- metal particles are formed from dissolved transition metal ions through continuous or semi-continuous reduction with one or more reducing agents,

- dissolved transition metal ions are formed from metal particles through continuous or semi-continuous oxidation of said particles,

- providing said aqueous, palladium-free activating composition wherein dissolved transition metal ions and their metal particles are repeatedly involved in said reduction and said oxidation, respectively, such that no precipitated agglomerates of said metal particles are formed; and

(c) contacting the substrate (substrate treated according to step (II)) with the activating composition such that a transition metal or transition metal alloy is deposited on the surface of the substrate and an activated surface for metallization is obtained. , the activating step

includes

Experiments by the present inventors have shown that very simple and effective activation is achieved without the need for elaborate stabilization/anti-oxidation of the particles formed in the present invention. Unlike typical activating compositions, it turns out that no stabilization/anti-oxidation of the formed particles is required. This is because, in the present invention, the particles are not formed for the purpose of keeping them as long as possible, but rather for the purpose of establishing an equilibrium between the dissolved transition metal ion and its respective particles, so that the particles intentionally/deliberately It means that by oxidation it makes it possible to re-form its individual ions repeatedly. Typically, in normal activating compositions, oxidation is considered detrimental and is thus minimized and/or inhibited. In contrast, in the present invention, oxidation is considered advantageously utilized, necessary, and of great advantage. Contrary to popular belief, it turns out that it is not necessary to maintain the particles in each activating composition for a long period of time.

This brings many benefits. For example, in a very simple way, the respective activating composition is easily set/activated where required by simply adding the required reducing agent. This means that product delivery time is not related to product/method lifetime.

The present invention relies on the fact that the particles are formed repeatedly in situ, which renders any stabilizer or stabilizer compound useless. For that purpose, dissolved transition metal ions and metal particles thereof exist in a reversible equilibrium. As a result, a very effective and strong activation can be achieved since new particles are formed in a relatively short lifetime without stabilizing compounds around them. Then, they are reacted back to their ionic form by oxidation. When additional reducing agent is added, new particles are formed again, ie in situ.

In the method of the present invention, a transition metal or transition metal alloy is deposited on the surface of the substrate, and an activated surface for subsequent metallization is obtained. This means that the concentration of dissolved metal ions of the first species decreases over time due to film formation. However, replenishment of the first species is easily achieved by simply adding an ion of that species. Therefore, supplementation is very easy and simple. This also significantly increases the lifetime of the respective activating composition and method associated therewith.

Additionally, each method and activating composition can be performed with inexpensive transition metals without necessarily requiring expensive precious metals.

DETAILED DESCRIPTION OF THE INVENTION

In the context of the present invention, “continuous,” “continuously,” and “continuously” mean, respectively, the continuous progress of each action without significant interruption of the action, e.g., while a respective method or aspect of the present invention is being performed. indicates performance.

In the context of this invention, “semi-continuous,” “semi-continuously,” and “semi-continuously” mean each, e.g., with one or more even significant interruptions of an action during the performance of a respective method or aspect of the invention. Indicates the execution of each action. Interruptions are longer than the time during which actions are performed in some cases. It even contains only temporary and simple actions.

In the context of the present invention, “species” (eg, a first species or a second species) refers to a chemical element. Thus, "dissolved transition metal ion of the first kind" refers to the dissolved metal ion of a transition metal element of Groups 3 to 12 of the periodic table, for example copper.

In the context of the present invention, "dissolved transition metal ions of a first species and additionally metal particles thereof" means dissolved metal ions of a first species and additional metal particles thereof, for example in an aqueous, palladium-free activating composition. represents the first type of metal particles.

write:

In step (I)(a) of the method of the present invention, a non-conductive or carbon fiber-containing substrate having a surface is provided. Such substrates inherently cannot be successfully metallized and require activation.

In the context of the present invention, activation means modifying the surface of a non-conductive or carbon fiber-containing substrate in such a way that it comprises a transition metal or transition metal alloy after each activation step with sufficient adhesion for subsequent metallization. Further, the deposited transition metal and transition metal alloy, respectively, can be deposited sufficiently on the surface such that subsequent metallization layers (i) can be deposited thereon and (ii) wholly and sufficiently adhere to the surface of the non-conductive or carbon fiber-containing substrate. are glued

The method of the present invention is preferred where the non-conductive substrate is preferably selected from the group comprising, and preferably consisting of, plastics, resin-containing laminates, glass, ceramics, semiconductors, and mixtures thereof.

Preferred plastics include thermoplastics and are preferably thermoplastics, more preferably polyacrylates, polyamides, polyimides, polyesters, polycarbonates, polyalkylenes, polyphenylenes, polystyrenes, polyvinyls or any of these A mixture is included, Preferably they are these.

Preferred polyacrylates include poly(methyl methacrylate) (PMMA).

Preferred polyimides include polyetherimide (PEI).

Preferred polyesters include polylactic acid (PLA).

Preferred polycarbonates include polycarbonate (PC) obtained with bisphenol A.

Preferred polyalkylenes include polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), polyoxymethylene (POM), or mixtures thereof.

Preferred polyphenylenes include poly(phenylene oxide) (PPO), poly(phenylene ether) (PPE), or mixtures thereof.

Preferred polystyrenes include polystyrene (PS), acrylonitrile butadiene styrene (ABS), styrene/butadiene rubber (SBR), and styrene-acrylonitrile (SAN).

Preferred polyvinyls include polyvinyl chloride (PVC), poly(ethylene-vinyl acetate) (PEVA), polyvinylidene difluoride (PVDF) or mixtures thereof.

Preferred resin-containing laminates include and are preferably fiber-reinforced resin-containing laminates, most preferably glass-fiber-reinforced laminates.

Very preferably, the resin-containing laminate comprises one or more polymers of epoxies, vinylesters, polyesters, amides, imides, phenols, alkylenes, sulfones or mixtures thereof, most preferably epoxies, imides or mixtures thereof. include as

A highly preferred resin-containing laminate preferably comprises FR4.

Preferred glasses include silica glass, soda lime glass, float glass, fluoride glass, aluminosilicate glass, phosphate glass, borate glass, borosilicate glass, chalcogenide glass, aluminum oxide glass or mixtures thereof, preferably These are.

Preferred ceramics preferably include glass-ceramics, aluminum oxide ceramics, or mixtures thereof.

Preferred semiconductors include, are preferably silicon-based semiconductors, more preferably silicon-based semiconductors comprising silicon dioxide and/or silicon.

A very preferred semiconductor is a wafer.

A method of the present invention is preferred, wherein the carbon fiber-containing substrate comprises, and preferably is, a carbon fiber composite and/or an array of carbon fiber filaments.

Preferred carbon fiber composites include and are preferably carbon fiber reinforced polymers and/or carbon fiber containing fabrics, more preferably carbon fiber reinforced polymers and/or woven carbon fiber containing fabrics.

Preferred arrangements of carbon fiber filaments include, are preferably fabrics made of carbon fibers, most preferably fabrics made of carbon fibers.

A particularly preferred carbon fiber-containing substrate is a carbon fiber-containing felt.

(I) conditioning (alternative name: pretreatment):

wherein the conditioning solution has an alkaline pH, preferably in the range of 9.0 to 14.0, more preferably in the range of 10.0 to 13.5, even more preferably in the range of 10.5 to 13.0 and most preferably in the range of 11.0 to 12.5; The method of the present invention is preferred.

Preference is given to methods of the present invention wherein the nitrogen-containing compound in the conditioning solution is a polymer, preferably a water soluble polymer.

More preferred are methods of the present invention wherein the nitrogen-containing compound in the conditioning solution is a polymer comprising pyrrolidine moieties.

Preferably, the polymer is cationic.

Preferably, the nitrogen-containing compound consists of carbon atoms, nitrogen atoms and hydrogen atoms.

Preference is given to methods of the present invention wherein the nitrogen-containing compound in the conditioning solution contains quaternary nitrogen atoms.

Most preferred is a method of the present invention wherein the nitrogen-containing compound comprises, preferably has, polyquaternium 6.

Another preferred process of the present invention is a process wherein the nitrogen containing compound comprises, preferably is a polymer resulting from polyaddition and/or polycondensation of at least one nitrogen containing compound. Examples are polyamides such as nylon 6, nylon 6,6, nylon 6,16 and polyurethane. Most preferred is a method of the present invention wherein the nitrogen-containing compound comprises, preferably comprises, a polymer of methylamine and epichlorohydrin.

The concentration of the nitrogen-containing compound is 0.1 g/L to 4 g/L, preferably 0.2 g/L to 2 g/L, more preferably 0.25 g/L to 1.5 g/L, more preferably 0.3 g/L to 2 g/L. A method of the present invention of 1 g/L is preferred.

The conditioning solution is in the range of 20 °C to 90 °C, preferably in the range of 25 °C to 80 °C, more preferably in the range of 30 °C to 70 °C, most preferably in the range of 40 °C to 60 °C during step (I)(c). Preference is given to the process of the invention, which has a temperature in the range of °C.

The process of the present invention wherein step (I)(c) is carried out for 1 to 10 minutes, preferably 2 to 8 minutes, more preferably 3 to 6 minutes and most preferably 3.5 to 5 minutes. this is preferable

(II) selector processing (alternative name: preprocessing):

Step (II) of the method of the present invention is a selector treatment of the surface of a non-conductive or carbon fiber-containing substrate, the selector treatment method comprising:

(a) providing a substrate treated according to step (I)

(b) (i) contains a nitrogen-containing compound;

(ii) having a pH of 9 to 14

providing a selector composition;

(c) contacting the substrate with the selector composition

includes

The selector composition has an alkaline pH, preferably in the range of 9.0 to 14.0, more preferably in the range of 10.0 to 13.5, even more preferably in the range of 10.5 to 13.0, most preferably in the range of 11.0 to 12.5, The method of the present invention is preferred.

Preference is given to the process of the present invention wherein the nitrogen-containing compound in the selector composition is an amine of the formula

NH _x [(CH ₂ ) _n OH] _3-x

where x = 0, 1, 2 or 3 and

n = 1, 2, 3 or 4.

More preferred is a process of the invention wherein the nitrogen-containing compound in the selector composition is selected from ammonia, monoethanolamine, triethanolamine, guanidine, guanidine derivatives such as guanidinium salts or mixtures thereof. A “guanidine derivative” in this context is understood as a guanidine compound, which is preferably a guanidine in which one or more hydrogens are substituted by a functional group, preferably hydroxy, halogen, amino or C1-C4 alkyl, and/or these guanidines The compound is selected from guanidinium salts.

The concentration of the nitrogen-containing compound in the selector composition is 1 g/L to 50 g/L, preferably 2 g/L to 40 g/L, more preferably 3 g/L to 35 g/L, more preferably 5 g/L to 30 g/L is preferred for the method of the present invention.

in the selector composition

(i) a) a first nitrogen-containing compound selected from ammonia, monoethanolamine, triethanolamine or mixtures thereof; and

b) a second nitrogen-containing compound selected from guanidine, guanidine compounds such as guanidinium salts, or mixtures thereof;

(ii) having a pH of 9 to 12, the method of the present invention is even more preferred.

in the selector composition

(i) a) a first nitrogen-containing compound selected from ammonia, monoethanolamine, triethanolamine or mixtures thereof; and

b) a second nitrogen-containing compound selected from guanidine, guanidine compounds such as guanidinium salts, or mixtures thereof;

(ii) has a pH of 9 to 12;

here

The concentration of the first nitrogen-containing compound in the selector composition is 1 g/L to 50 g/L, preferably 2 g/L to 40 g/L, more preferably 3 g/L to 35 g/L, more preferably preferably 5 g/L to 30 g/L,

The concentration of the second nitrogen-containing compound in the selector composition is 1 g/L to 10 g/L, preferably 2 g/L to 8 g/L, more preferably 3 g/L to 7 g/L, more preferably Preferably from 4 g/L to 6 g/L, the method of the present invention is even more preferred.

Preferably the selector composition is

(i) a) a first nitrogen-containing compound selected from ammonia, monoethanolamine, triethanolamine or mixtures thereof; and

b) a second nitrogen-containing compound selected from guanidine, guanidine compounds such as guanidinium salts, or mixtures thereof;

(ii) has a pH of 9 to 12;

here

The concentration of the first nitrogen-containing compound in the selector composition is 1 g/L to 50 g/L, preferably 2 g/L to 40 g/L, more preferably 3 g/L to 35 g/L, more preferably preferably 5 g/L to 30 g/L,

The concentration of the second nitrogen-containing compound in the selector composition is 1 g/L to 10 g/L, preferably 2 g/L to 8 g/L, more preferably 3 g/L to 7 g/L, more preferably preferably 4 g/L to 6 g/L.

During step (II)(c) the selector composition is in the range of 20 °C to 90 °C, preferably in the range of 25 °C to 80 °C, more preferably in the range of 30 °C to 70 °C, most preferably in the range of 40 °C to 60 °C. Preference is given to the process of the invention, which has a temperature in the range of °C.

Step (II)(c) is carried out for 1 to 10 minutes, preferably 2 to 8 minutes, more preferably 3 to 7 minutes, still more preferably 3.5 to 6 minutes, most preferably Preference is given to the method of the present invention, which is carried out for 4 to 5.5 minutes.

(III) an aqueous, palladium-free active composition:

In step (III)(b) of the process of the present invention, an aqueous palladium-free activating composition is provided.

The aqueous composition utilized in the method of the present invention is an aqueous composition, meaning that water is the major component. Thus, greater than 50% by weight of the composition, preferably at least 70% by weight, even more preferably at least 90% by weight and most preferably at least 95% by weight of the composition, based on the total weight of the aqueous composition, is water. Although rare, it is preferred that the composition includes one or more solvents (other than water) that are miscible with water. Most preferred (for ecological reasons), however, is a process in which water is the only solvent and, therefore, most preferably the composition is substantially free of or completely free of organic solvents.

In the context of the present invention, the term “substantially does not exist or does not contain” a subject-matter (e.g., compound, chemical, material, etc.) means that the material does not exist at all (“does not contain ") or present only in very small and non-interfering amounts ("substantially absent") without affecting the intended purpose of the present invention. For example, such objects may be added or utilized unintentionally, eg as unavoidable impurities. "Substantially free of" is preferably from 0 (zero) ppm to 5 ppm, preferably from 0 ppm to 3 ppm, more preferably from 0 ppm to 1.5 ppm, based on the total weight of the activating composition, for example. ppm, even more preferably from 0 ppm to 1 ppm, most preferably from 0 ppm to 0.5 ppm, even more preferably from 0 ppm to 0.1 ppm. This principle applies to other objects as well, for example to the total weight of the transition metal or transition metal alloy obtained in step (III)(c) of the method of the present invention.

The activating composition has an acidic pH, neutral pH, or alkaline pH, preferably an acidic or neutral pH, most preferably an acidic pH.

PH of the activating composition is in the range of ≥ 2.0 to ≤ 13.0, preferably in the range of ≥ 3.0 to ≤ 12.0, more preferably in the range of ≥ 4.0 to ≤ 11.0, most preferably in the range of ≥ 4.5 to ≤ 10.0 The method of the invention is preferred.

In some cases, the method of the present invention is preferred, and the pH of the activating composition is in the range of ≥ 3.0 to ≤ 6.5, preferably in the range of ≥ 4.0 to ≤ 6.0. Preferably this applies provided that the at least one reducing agent comprises a borohydride.

The pH of the activating composition is typically a result of the presence of (i) to (iv). If pH adjustment is required, it is performed by conventional means. Preferred acids are mineral acids and organic acids. A preferred mineral acid is sulfuric acid. A preferred organic acid is the acid form of one or more complexing agents. Preferred alkaline compounds are alkaline hydroxides, preferably NaOH, alkaline carbonates, preferably sodium carbonate and ammonia.

In the context of the present invention, pH is determined at a temperature of 20°C, ie the defined pH is based on 20°C. Thus, for pH determination only, the activating composition has a temperature of 20°C. This does not mean that the activating composition itself is limited to a specific temperature of 20°C. For preferred temperatures of the activating composition see below.

If the pH is significantly below 2 or above 13, insufficient activation is obtained most of the time. If the pH is too acidic, the acid-sensitive reducing agent typically decomposes too quickly. Conversely, if the pH is too alkaline, the alkali-sensitive reducing agent will decompose too quickly.

The aqueous composition used in the process of the present invention is palladium-free. Thus, the activating composition is substantially free of or free of palladium ions. This means that no compounds containing palladium are present, nor are palladium atoms/particles or palladium ions. Advantageously, the present invention is an excellent alternative to palladium-containing activation processes that have identical or at least nearly identical results in terms of activation.

Preferably also no other precious metals or at least expensive/rare metals are required in the activating composition. Thus, the activating composition is substantially free of or does not include platinum ions, gold ions, silver ions, rhodium ions, ruthenium ions, and iridium ions, and is preferably substantially free of platinum, gold, silver, rhodium, ruthenium, and iridium. Preferred are methods of the present invention that do not or do not contain them.

The aqueous composition utilized in the process of the present invention comprises (i) a dissolved transition metal ion of a first species and additionally metal particles thereof.

An activating composition in which the metal particles are nanoparticles is preferred. Preferably, the metal particles comprise at least one elemental metal (Me ⁰ ) and preferably consist (essentially) of at least one elemental metal (Me ⁰ ).

The first type of metal particle is in the range of 0.1 nm to 500 nm, preferably in the range of 0.5 nm to 200 nm, more preferably in the range of 1.0 nm to 100 nm, most preferably in the range of 3 nm to 50 nm, even more preferably Even more preferred is an activating composition having a particle diameter in the range of 5 nm to 15 nm.

More preferred are methods of the present invention wherein the first type of metal particles in the activating composition are colloidal metal particles.

Thus, preferred is a method of the present invention wherein the activating composition is a colloid, preferably a colloidal suspension. However, the activating composition is still a transparent but colored solution, mainly depending on the coloring effect caused by the dissolved ions of the first species.

In the activating composition, said dissolved transition metal ions of a first species and said metal particles thereof together form the total amount of a metal of a first species. In the activating composition, the first type of metal ion and its metal particles are in the range of 0.05 g/L to 30.0 g/L, preferably 0.07 g/L, based on the total volume of the activating composition and based on the ionic, non-specific form. g/L to 18.0 g/L, more preferably 0.09 g/L to 12.0 g/L, even more preferably 0.11 g/L to 8.0 g/L, most preferably 0.15 g Preference is given to methods of the present invention which form a total concentration in the range of /L to 6.0 g/L, more preferably in the range of 0.2 g/L to 3.0 g/L. This means that in order to determine the total concentration, the transition metal particles of the first type are considered/counted as dissolved metal ions.

Although the process of the present invention can basically be carried out with relatively high concentrations of the first species, it surprisingly turns out that very low concentrations are already sufficient for very efficient and good results (see examples). This is particularly advantageous in terms of wastewater treatment and is thus cost-free and environmentally friendly.

Preference is given to a process of the invention wherein the first species is copper or cobalt, preferably copper. Copper and cobalt are cost effective metals compared to the commonly used palladium but achieve sufficient activation on the surface of non-conductive or carbon fiber containing substrates. The foregoing concentrations most preferably apply to copper and cobalt, most preferably to copper.

The method of the present invention, wherein the source of dissolved copper ions is selected from the group consisting of copper sulfate, copper chloride, copper nitrate, copper fluoroborate, copper acetate, copper citrate, copper phenylsulfonate, copper para-toluene sulfonate and copper alkyl sulfonate desirable. A preferred copper alkylsulfonate is copper methanesulfonate. The most preferred copper source is copper sulfate, most preferably CuSO ₄ * 5 H ₂ O.

Optionally, the aqueous, palladium-free activating composition comprises (iv) at least one dissolved metal ion of a second species different from the first species. Preferably, the second species is substantially free of or free of alkali metals.

Preference is given to the method of the invention, wherein the at least one second species is selected from the group consisting of a transition metal and magnesium, preferably nickel, cobalt, iron and magnesium, preferably nickel and cobalt, more preferably nickel. With dissolved metal ions of the second species, each transition alloy is preferably deposited in step (c) of the method of the present invention.

It is preferred that the method of the present invention wherein the at least one second species is substantially free of or does not contain tin.

In addition to the first species and the optional second species, the aqueous, palladium-free activating composition comprises (ii) one or more complexing agents. Preferably, the one or more complexing agents are suitable for complexing with at least one dissolved transition metal ion.

The at least one complexing agent is an organic complexing agent, preferably a carboxylic acid and/or salt thereof, more preferably a dicarboxylic acid or tricarboxylic acid and/or salt thereof, even more preferably a tricarboxylic acid and/or salt thereof. or salts thereof, most preferably hydroxy tricarboxylic acids and/or salts thereof, even more preferably citric acid, structural isomers and/or salts thereof. A preferred structural isomer is iso-citric acid and its salts. Most preferably, the one or more complexing agents defined above (including preferred variants) are the only complexing agents in the active composition.

in the active composition

- the first type of metal ion and its metal particles together form a total concentration based on the total volume of the activating composition and based on the ionic, non-specific form,

- at least one complexing agent in total concentration ranges from 1.0 : 0.2 to 1.0 : 100.0, preferably ranges from 1.0 : 0.5 to 1.0 : 50.0, more preferably ranges from 1.0 : 0.85 to 1.0 : 25.0, even more preferably is present in a molar ratio ranging from 1.0:0.95 to 1.0:15.0, even more preferably from 1.0:1.0 to 1.0:10.0, most preferably from 1.0:1.1 to 1.0:5.0. desirable.

It is very preferably that the at least one complexing agent is a tricarboxylic acid and/or salt thereof, more preferably a hydroxy tricarboxylic acid and/or salt thereof, most preferably citric acid, structural isomers and/or salts thereof. If included, it applies.

The at least one complexing agent in the activating composition is in the range of 0.01 mol/L to 0.5 mol/L, preferably in the range of 0.015 mol/L to 0.35 mol/L, more preferably in the range of 0.02 mol/L, based on the total volume of the activating composition. to 0.3 mol/L, most preferably in the range of 0.023 mol/L to 0.275 mol/L.

In addition to the first species, the optional second species, and one or more complexing agents, the aqueous, palladium-free activating composition permanently or temporarily comprises (iii) one or more reducing agents. One or more reducing agents are necessary to form metal particles from at least one dissolved transition metal ion. Thereby dissolved transition metal ions are chemically reduced, continuous or semi-continuous to form the particles. Thus, the particles are formed continuously or semi-continuously, respectively, depending on the presence of one or more reducing agents in the activating composition, permanent or temporary. However, when more than one reducing agent is present, typically the particles will form until the reducing agent is exhausted or insufficiently present. Preference is given to methods of the invention in which oxidation affects the particles and is in some competition with reduction. Typically, oxidation begins as soon as one or more reducing agents are exhausted, which is explicitly preferred in the context of the present invention.

In the process of the present invention, said oxidation is furthermore suitable if after one or more of the first steps (c) the process is stopped for a relatively long time. In order to avoid precipitation of agglomerates during this time, the oxidation in the activating composition is carried out until the particles are no longer present, but rather only dissolved transition metal ions. Preferably, oxidation is accelerated by adding an oxidizing agent, more preferably peroxide, most preferably hydrogen peroxide. Upon resuming operation, the particles are formed by continuously or semi-continuously adding one or more reducing agents to reform the particles. Then, the method of the present invention is resumed.

Thus, preferably one or more reducing agents are suitable for reducing at least one dissolved transition metal ion.

In some cases, it is preferred that the method of the present invention wherein the at least one reducing agent comprises at least one hydrogen atom, such that when reducing the transition metal ion, hydrogen is released, which is at least partially adsorbed on the activated surface.

It is preferred that the method of the present invention wherein the at least one reducing agent comprises a boron-containing reducing agent, preferably a borohydride. Preferred borohydrides include inorganic borohydrides and/or organic borohydrides. Preferred organic borohydrides include alkylaminoboranes, most preferably dimethylaminoboranes. Preferred inorganic borohydrides include alkali borohydride, most preferably sodium borohydride. In the process of the present invention, most preferred is alkali borohydride, preferably sodium borohydride. This allows for a slightly acidic pH and temperature in step (c) of the process of the present invention in a suitable range, preferably between 15°C and 30°C. These are excellent room temperature conditions. Additional and costly heating is therefore not necessarily required. Also, hydrogen is produced.

Preferably, the boron-containing reducing agent, preferably borohydride, more preferably alkali borohydride and/or alkylaminoborane, most preferably sodium borohydride and/or dimethylaminoborane, is the only agent in the activating composition. It is a reducing agent.

As a result of utilizing borohydride in the activating composition as one of the one or more reducing agents, boric acid and/or salts thereof are typically formed.

In some cases, a method of the present invention is preferred, wherein the one or more reducing agents comprises an aldehyde, preferably formaldehyde, glyoxylic acid, a salt of glyoxylic acid, or mixtures thereof, most preferably as the only reducing agent. In this case the formation of boric acid is avoided.

In some cases, it is preferred that the method of the present invention wherein the one or more reducing agent comprises hydrazine, most preferably as the sole reducing agent. Also in this case the formation of boric acid is avoided.

The activation composition is in the range of 0.2 mmol/L to 500.0 mmol/L, preferably in the range of 0.4 mmol/L to 350.0 mmol/L, more preferably in the range of 0.6 mmol/L to 250.0 mmol/L, based on the total volume of the activation composition. at least one reducing agent at a total concentration in the range of L, even more preferably in the range of 0.8 mmol/L to 150.0 mmol/L, most preferably in the range of 1.0 mmol/L to 80.0 mmol/L. method is preferred. Particularly preferred total concentrations are in the range of 0.9 mmol/L to 50.0 mmol/L, very preferably in the range of 1.0 mmol/L to 30.0 mmol/L, most preferably in the range of 1.1 mmol/L to 10.0 mmol/L. Most preferably, this applies to the aforementioned preferred, more preferred, etc. reducing agent, most preferably borohydride.

in the active composition

- the first type of metal ion and its metal particles together form a total concentration based on the total volume of the activating composition and based on the ionic, non-specific form,

- at least one reducing agent in total concentration (at the moment of addition, if added semi-continuously) is greater than 0.5, preferably greater than 1, more preferably greater than 2, even more preferably greater than 3, most preferably greater than 3.5 Present in molar ratios, the method of the present invention is generally preferred. Molar ratios in the range of 1 to 20 are highly preferred. Thus, in the activating composition, the at least one reducing agent is preferably present (permanently or temporarily) in such a total concentration that the dissolved transition metal ions of the first species are not quantitatively reduced to individual particles. Moreover, it is preferred that the method of the present invention wherein the activating composition does not primarily exhibit a reducing environment to prevent oxidation of the metal particles. Conversely, as already mentioned, oxidation is necessary and desirable. Thus, a method of the present invention is preferred, wherein the activating composition is maintained primarily in oxidizing conditions to allow oxidation of the metal particles.

in the active composition

- the first type of metal ion and its metal particles together form a total concentration based on the total volume of the activating composition and based on the ionic, non-specific form,

- in total concentration (when added, if added semi-continuously) at least one reducing agent in the range of 0.3 to 60.0, preferably in the range of 0.5 to 30.0, more preferably in the range of 1.0 to 20.0, even more preferably in the range of 1.5 to 10.0 , most preferably in a molar ratio ranging from 1.8 to 3.0.

In some cases, the method of the present invention is preferred wherein the one or more reducing agents are permanently present in the aqueous, palladium-free activated composition. Accordingly, it is preferred that the one or more reducing agents are added to the activating composition continuously, preferably by a permanent flow of each liquid containing said one or more reducing agents. In this approach, oxidation and reduction occur simultaneously over time while step (c) of the method of the present invention is carried out. As a result, metal particles are present in a relatively constant concentration.

Alternatively, methods of the present invention are preferred, wherein the at least one reducing agent is transiently present in an aqueous, palladium-free activated composition. Thus, preferably at least one reducing agent is applied semi-continuously; For example, it is added in successive parts with time-wise breaks between each part. This means that new particles are formed when one or more reducing agents are added. However, during shutdown, oxidation that produces dissolved transition metal ions is very prevalent. As a result, metal particles are basically present in various concentrations. However, depending on the length of the temporal interruption and ensuring that the interruption is not too long, this approach is completely sufficient to successfully activate the surfaces of even a plurality of non-conductive or carbon fiber containing substrates. Therefore, this approach is particularly preferred.

In either case, however, it is preferred that the method of the present invention is present in such a way that the equilibrium is reversibly maintained. Thus, a reversible equilibrium is not a side reaction or an undesirable side reaction.

Upon oxidation, the total concentration of dissolved transition metal ions in the activating composition increases essentially as a result of a reversible equilibrium wherein the total amount of said metal particles decreases. This reversible equilibrium is preferably monitored for better process control. Thus, a method of the present invention in which the reversible equilibrium is monitored by UV/VIS inspection is preferred. Preferably, the dissolved transition metal ion is in the range of 700 nm to 800 nm, preferably in the range of 710 nm to 780 nm, more preferably in the range of 720 nm to 760 nm, most preferably in the range of 730 nm to 750 nm are monitored at wavelengths within It is also preferred that the metal particles are monitored at a wavelength within the range of 400 nm to 600 nm, preferably within the range of 450 nm to 550 nm. This allows determining when to add one of the one or more reducing agents to form, preferably reform, the metal particles to increase the total amount of metal particles.

Thus, one or more reducing agents are continuously or semi-continuously added to the activating composition so that additional metal particles are formed, respectively, continuously or semi-continuously from dissolved transition metal ions of the first species, preferably one or more Preference is given to the process of the present invention, which is added after step (c) has been performed.

It is preferred that the method of the present invention wherein the metal particles of the first type are formed continuously or semi-continuously in situ in the activating composition by said reduction after and/or during at least one step (c) has been carried out. This preferably defines that in the method of the present invention step (c) is carried out more than once, preferably the method comprising step (c) is carried out repeatedly. It is highly preferred that once, more than once, or after each step (c) of the method of the present invention, metal particles are formed anew by said reduction. This is possible because the oxidation is allowed and desired, preferably continuously but at least semi-continuously, resulting in new dissolved transition metal ions ready for re-reduction. This is in contrast to the usual approach, where metal particles are formed (and stabilized) before activation is performed, and then typically followed by particle stabilization for as long as possible until the respective activation composition is unstable and unusable.

As mentioned throughout the specification, in the context of the present invention it is preferably necessary to add the reducing agent at least semi-continuously. Typically, the reducing agent used for the reduction reacts with the dissolved transition metal ions and results in reducing agent decomposition products, preferably boric acid and/or salts thereof. Usually, these degradation products accumulate in the activating composition, which is undesirable in the context of the present invention. Therefore, the method of the present invention, which is a method performed by bleed and feed, is preferred. In this approach, a certain volume of the activating composition is removed (eg by dragging out; thus also removing degradation products), in such a way that the essential components of the activating composition have sufficiently constant concentrations (eg replenishment). by) is replaced by the replacement volume. This means that the replacement volume is typically free of boric acid and/or its salts, and preferably free of reducing agent decomposition products. This is also advantageous for stabilizing the pH to an essentially constant pH.

The activating composition contains boric acid and/or salts thereof in an amount of 5 g/L or less, preferably 3 g/L or less, more preferably 2 g/L or less, and most preferably 1.2 g/L or less, based on the total volume of the activating composition. Preference is given to methods of the present invention, including at total concentrations of g/L or less. This preferably applies provided that (1) the at least one reducing agent comprises borohydride and (2) step (c) is performed at least once.

It is preferred for the method of the present invention that the reversible equilibrium does not shift in favor of the metal particles over most of the time step (c) is carried out.

It is preferred that the process of the present invention wherein during and/or after step (c) most of the metal particles undergo the oxidation. Most preferably means more than 50% of the particles.

Preferably, the one or more reducing agents are substantially free or free of hypophosphite ions, and preferably substantially free of or free of phosphorus-containing reducing agents. Our experiments have shown that in some cases the activation with these reducing agents is too weak or even incomplete.

As already outlined above, the activating composition does not additionally require a stabilizing compound. Thus, it is preferred that the method of the present invention wherein the activating composition is substantially free of or free of compounds that prevent oxidation of the metal particles and/or substantially free of or free of stabilizer compounds for stabilizing the metal particles. Preferably, the activating composition is substantially free of or includes no stabilizer compounds for stabilizing the metal particles by preventing agglomeration of the metal particles. In the context of the present invention, at least one reducing agent (temporarily or permanently present in the activating composition) and a compound involved in oxidation, preferably ambient air and/or oxygen gas (i.e. most preferably molecular oxygen), are such compounds not considered as A small amount of one or more reducing agents is required to form the metal particles, which involves reforming the particles. This means that the activating composition is substantially free of or free of, in addition to said one or more reducing agents and compounds involved in oxidation, stabilizer compounds and/or compounds that prevent oxidation of metal particles. Thus, it is preferred that the process of the present invention wherein the one or more reducing agents are not present in a total amount to prevent oxidation, and preferably not present in a total amount to prevent oxidation after or during one or more step (c) is performed. . As outlined, oxidation, most preferably through ambient air, is necessary to reform the dissolved transition metal ions, so that precipitate agglomerates of the metal particles do not form.

It is preferred for the method of the present invention that the activating composition is substantially free of or free of compounds that completely or partially encapsulate the metal particles or completely or partially adsorb onto the surface of the particles. Some stabilizer compounds are believed to be based on this function. In the context of the present invention, this is not desired.

In general, the method of the present invention is preferred wherein the activating composition is substantially free of or free of compounds that prevent the equilibrium from becoming reversible, and/or substantially free of or free of compounds to shift the equilibrium completely toward the metal particle. do. Again, the one or more reducing agents are not considered such compounds for the reasons outlined above.

The activating composition is substantially free of or free of tin ions, preferably substantially free of tin ions, lead ions, germanium ions, gallium ions, antimony ions, bismuth ions and aluminum ions, and more preferably elemental Methods of the present invention that are substantially free or free of metal ions of groups III, IV and V of the periodic table are preferred. In the context of the present invention, "main group III metal ions" do not include respective boron-containing ions. Tin ions in particular are very well known, for example, to prevent oxidation of the copper particles in the respective palladium-free copper-tin activating compositions, thereby preventing the equilibrium from becoming reversible. These stannous ions typically form a reducing environment, which is by no means desirable in the context of the present invention.

The activating composition is substantially free of or free of polyvinylpyrrolidone, preferably substantially free of or free of polyvinyl compounds, and more preferably substantially free of or free of organic polymers comprising vinyl moieties. Preferred are methods of the present invention that do not contain, and most preferably are substantially free of, or free of, dissolved organic polymers.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or free of proteins, agar, gum arabic, sugars and polyalcohols.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or does not include glycerol.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or does not include gelatin.

The activating composition is substantially free of or free of thiourea, preferably substantially free of or free of sulfur-containing compounds having divalent sulfur, and more preferably containing sulfur with an oxidation number of +5 or less. Methods of the present invention that are substantially free of or free of sulfur-containing compounds are preferred.

The method of the present invention is preferred, wherein the activating composition is substantially free of or free of compounds comprising an aromatic ring and a sulfonic acid group (including salts thereof), preferably substantially free of or free of sulfonic acids or salts thereof. do.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or does not include a compound designated Orzan-S.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or free of urea.

It is preferred for the method of the present invention that the activating composition is substantially free of or free of a dispersant.

The activating composition is substantially free of or free of polyethyleneimines, preferably substantially free of or free of polyalkylenimines, and most preferably substantially free of or free of organic polymers comprising imine moieties. , the method of the present invention is preferred.

In particular, the polymers mentioned above are commonly used as stabilizer compounds for stabilizing metal particles. However, polymers are not required in the context of the present invention. Also, metal particles are believed to be significantly more effective/more active if these molecules do not form a shell around the particle.

The activating composition is substantially free of or free of sodium dodecyl sulfate, preferably substantially free of or free of alkyl sulfates having from 8 to 20 carbon atoms, and more preferably substantially free of or including alkyl sulfates. Preferred are the methods of the present invention that do not contain, and most preferably are substantially free of or free of surfactants.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or free of hydroquinone, pyrogallol, and/or resorcinol, and preferably substantially free of or free of hydroxy benzene. In many cases these hydroxybenzenes are generally used as antioxidants to prevent the equilibrium from becoming reversible, which is not required in the activating composition.

It is preferred that the method of the present invention wherein the activating composition is substantially free of or does not include quinones.

It is preferred for the method of the present invention that the active composition is substantially free of or free of fatty alcohols.

It is preferred for the method of the present invention that the activating composition is substantially free of or free of alkylene glycols, and preferably substantially free of or free of glycols.

It is preferred for the method of the present invention that the activating composition is substantially free of or free of manganese ions.

It is preferred for the method of the present invention that the activating composition is substantially free of or free of zinc ions.

As a result and in particular despite the fact that the activating composition does not contain a stabilizing compound and/or a compound that prevents oxidation of the metal particles, the activating composition is substantially free of or does not contain precipitated agglomerates of the metal particles of the present invention. method is preferred. This is achieved because oxidation is not inhibited (i.e. not avoided), but rather because at least one dissolved transition metal ion and metal particles thereof are repeatedly involved in the reduction and the oxidation, respectively.

"Repeatedly involved" specifies at least more than 1 time, preferably more than 2 times, even more preferably more than 3 times, most preferably more than 4 times, even more preferably over the entire lifetime of the active composition. Preferred is the method of the present invention, comprising

Our experiments show that oxidation in particular prevents aggregation. The metal particles are oxidized back to their ionic/dissolved form. This means that the particles do not have enough time to form higher-order aggregates and even form agglomerates. Each suitable oxidizing agent is basically applicable, but ambient air has proven to be an excellent choice. It is powerful enough and available everywhere. Preference is given to the method of the invention, wherein the formation of sedimentary agglomerates of the metal particles is prevented through said oxidation, preferably through oxidation by ambient air and/or oxygen gas. Methods of the present invention are preferred, wherein dissolved transition metal ions are formed from metal particles through oxidation by ambient air and/or oxygen gas. In both cases, the preferred oxidizing agent is molecular oxygen. Most preferred are methods of the present invention in which the majority of the dissolved transition metal ions are formed from the majority of metal particles through oxidation by ambient air and/or oxygen gas.

In some cases, the method of the present invention is preferred, wherein the continuous or semi-continuous oxidation is additionally or solely achieved through an oxidizing agent other than molecular oxygen, more preferably through a peroxide, and most preferably through hydrogen peroxide. In particular, in addition to ambient air, this preferably accelerates the oxidation of the particles, if this is necessary, for example if the activating composition is to be inactivated and stored for a longer period of time.

In order to sufficiently facilitate oxidation in the activating composition, a method of the present invention is preferred wherein the activating composition is cycled continuously or semi-continuously, preferably by shaking, stirring and/or pumping. This is desirable to ensure that oxidation is evenly distributed throughout the entire activating composition. In other words, this ensures that the metal particles are equally contacted with the oxidizing agent, facilitating oxidation.

Most preferred is a method for (activating) the surface of a non-conductive or carbon fiber-containing substrate for metallization, the method comprising the following steps:

(a) providing the substrate;

(b) providing an aqueous, palladium-free activating composition;

(i) dissolved transition metal ions of a first species and further colloidal metal particles thereof, wherein the first species is copper;

(ii) at least one complexing agent comprising hydroxy tricarboxylic acids and/or salts thereof, preferably citric acid, structural isomers and/or salts thereof;

(iii) permanently or temporarily at least one boron-containing reducing agent, preferably borohydride;

(iv) optionally, one or more dissolved metal ions of a second species different from the first species, wherein the second species is preferably nickel.

including,

here

- the activating composition is a colloidal suspension,

- at least one type of dissolved transition metal ion and its metal particles are in reversible equilibrium, provided that

- metal particles are formed from dissolved transition metal ions through continuous or semi-continuous reduction with one or more reducing agents,

- dissolved transition metal ions are formed from metal particles through continuous or semi-continuous oxidation of said particles through oxidation by ambient air,

-providing said aqueous, palladium-free activating composition wherein dissolved transition metal ions and their metal particles are repeatedly involved in said reduction and said oxidation, respectively, to avoid formation of precipitate agglomerates of said metal particles;

(c) contacting a substrate with the activating composition such that a transition metal or transition metal alloy is deposited on the surface of the substrate and an activated surface for metallization is obtained, wherein the metal particles are subjected to at least one step (c) contacting the substrate with the activating composition, which is formed continuously or semi-continuously in situ in the activating composition by the reduction, after and/or during the performed step.

includes

The present invention also relates to a method for preparing an aqueous, palladium-free activating composition (preferably the activating composition utilized in the process of the present invention) for activating the surface of a non-conductive or carbon fiber containing substrate for metallization, wherein the Here are the steps

(One) - dissolved transition metal ions of the first kind, and

- at least one complexing agent, and

- optionally, at least one dissolved metal ion of a second species different from the first species

Providing a starting aqueous solution comprising

(2) Finally, continuously or semi-continuously adding one or more reducing agents to the starting solution such that metal particles of the first type of dissolved transition metal ion are respectively continuously or semi-continuously formed in the solution.

including,

provided that the metal particles are continuously or semi-continuously oxidized to form dissolved transition metal ions of the first species, the method comprising the aqueous, palladium-free activating composition according to any one of claims 1 to 10 used to provide

In other words, this method of preparing an aqueous non-palladium activating composition for activating the surface of non-conductive or carbon fibers is used to provide an aqueous non-palladium activating composition according to the present invention.

What has been described above with respect to the process of the present invention likewise applies, preferably as defined above, to the process of the present invention for preparing an aqueous, palladium-free activating composition, most preferably as preferred.

The present invention also relates to the production of a first species in combination with the continuous or semicontinuous oxidation of a first species of metal particles in reversible equilibrium to continuously or semicontinuously form metal particles in situ in an aqueous, palladium-free activating composition. It relates to the use of continuous or semi-continuous reduction of dissolved transition metal ions.

What has been said above with respect to the process of the present invention likewise applies, preferably as defined above, to the use of the present invention, most preferably as preferred.

The present invention also relates to an aqueous, palladium-free activating composition for activating the surface of a non-conductive or carbon fiber containing substrate for metallization, said composition comprising:

(i) dissolved transition metal ions of the first type and further metal particles thereof;

(ii) one or more complexing agents;

(iii) one or more reducing agents, either permanently or temporarily;

(iv) optionally, one or more dissolved metal ions of a second species different from the first species.

including,

here

- at least one type of dissolved transition metal ion and its metal particles are in reversible equilibrium, provided that

- metal particles are formed from dissolved transition metal ions through continuous or semi-continuous reduction with one or more reducing agents,

- dissolved transition metal ions are formed from metal particles through continuous or semi-continuous oxidation of said particles,

- Dissolved transition metal ions and their metal particles are repeatedly involved in the reduction and the oxidation, respectively, to prevent the formation of precipitate agglomerates of the metal particles.

What has been described above with respect to the method of the present invention likewise preferably applies to the aqueous, palladium-free activated composition of the present invention, most preferably as defined above as preferred.

Preferably, the activating composition of the present invention is in the range of 10°C to 90°C, preferably in the range of 14°C to 75°C, more preferably in the range of 16°C to 65°C, most preferably in the range of 18°C to 45°C, even more Most preferably it is obtained at and/or has a temperature in the range of 20°C to 32°C. A temperature in the range of 18°C to 45°C, preferably in the range of 20°C to 32°C is particularly preferred, provided that the at least one reducing agent is borohydride, preferably sodium borohydride. This applies particularly preferably also to the process of the invention (for preparing said activating composition) and to the process of the invention.

More preferably, the activating composition of the present invention is not obtained at and/or does not have a temperature above 110°C, preferably above 100°C, more preferably above 95°C. Most preferably, the activating composition of the present invention is not obtained at temperatures above 110°C. This likewise preferably applies to the process of the invention (for preparing said activating composition) and to the process of the invention.

Activation (Step (III)):

In step (III)(c) of the method of the present invention, the substrate is treated with an aqueous, palladium-free activating composition to obtain an activated surface for metallization by depositing a metal or metal alloy, i.e., by depositing a seed or activation layer. come into contact

The contacting in step (III)(c) is in the range of 10°C to 90°C, preferably in the range of 14°C to 75°C, more preferably in the range of 16°C to 65°C, most preferably in the range of 18°C to 45°C, even more preferably in the range of 18°C to 45°C Preference is given to the process of the present invention, most preferably carried out at a temperature in the range of 20° C. to 32° C. A temperature in step (III)(c) in the range of 18° C. to 45° C., preferably in the range of 20° C. to 32° C., wherein the reduction via one or more reducing agents is carried out by borohydride, preferably sodium borohydride it's a ride

The contacting in step (III)(c) is carried out for a time ranging from 1 minute to 10 minutes, preferably from 2 minutes to 8 minutes, more preferably from 3 minutes to 6 minutes, and most preferably from 3.5 minutes to 5 minutes. , the method of the present invention is preferred.

Preference is given to the process of the present invention, wherein step (III)(c) is followed by a rinsing step. In this case, a rinsed, activated surface for metallization is obtained. Preferably, rinsing is performed with water.

At least 10 days, preferably at least 50 days, more preferably at least 200 days, even more preferably at least 1 year, without replacing most of the active composition (i.e., greater than 50% by volume of the composition) in one step , most preferably the method of the present invention, which is a method carried out for at least 2 years, even most preferably for at least 5 years.

Metallization:

The present invention also relates to a method for metallizing an activated surface of a non-conductive or carbon fiber-containing substrate, the method comprising the steps of:

(A) providing a non-conductive or carbon fiber-containing substrate having an activated surface for metallization obtained by the method of the present invention, preferably as defined as preferred throughout the specification; and

(B) metallizing the activated surface by contacting the activated surface with a first metallization solution such that a first metallization layer is deposited on the activated surface.

In step (A) of the process of the invention (for metallization), a non-conductive or carbon fiber-containing substrate having an activated surface is provided as obtained by the process of the invention; For details, refer to the above specification. What has been said above with respect to the process of the invention preferably applies to the process of the invention for metallization, most preferably as described with preference.

The method of the present invention (for metallization) wherein in step (B) the first metallization layer is a separate layer deposited on the transition metal or transition metal alloy obtained in step (III)(c) of the method of the present invention. desirable.

In step (B) the first metallization solution is essentially free of or does not contain a reversible equilibrium between metal ions and their particles; Preferred are the methods of the present invention (for metallization), more preferably essentially free of or free of metal/metal alloy particles, and most preferably essentially free of or free of any particles.

Preference is given to a method of the invention (for metallization) wherein the first metallization solution in step (B) comprises a reducing agent or no reducing agent.

Step (B) is in the range of 10°C to 95°C, preferably in the range of 15°C to 85°C, more preferably in the range of 20°C to 65°C, still more preferably in the range of 25°C to 55°C, most Preference is given to the process of the invention (for metallization), which is preferably carried out at a temperature in the range of 30° C. to 45° C.

Step (B) is carried out for 30 seconds to 180 minutes, preferably 45 seconds to 120 minutes, more preferably 1 minute to 60 minutes, most preferably 1.5 minutes to 45 minutes. The method of the invention is preferred.

The first metallization solution in step (B) does not contain a reducing agent, preferably contains at least one ionic species selected from the group consisting of palladium ions, platinum ions, silver ions, gold ions and mercury ions, more preferably is an immersion type metallization solution comprising palladium ions, most preferably with a total concentration ranging from 0.05 mg/L to 20 mg/L. .

More preferred is the method of the present invention (for metallization) wherein the first metallization solution in step (B) is an acidic palladium immersion type metallization solution.

The first metallization solution in step (B) is in the range of 0.09 mg/L to 10.0 mg/L, preferably in the range of 0.1 mg/L to 5.0 mg/L, more preferably in the range of 0.1 mg/L to 5.0 mg/L, based on the total volume of the metallization solution. is in the range of 0.12 mg/L to 3.0 mg/L, even more preferably in the range of 0.15 mg/L to 2.0 mg/L, most preferably in the range of 0.2 mg/L to 1 mg/L, even more preferably in the range of 0.2 mg/L to 1 mg/L is an immersion type metallization solution comprising palladium ions in a total concentration ranging from 0.22 mg/L to 0.75 mg/L. This applies in particular if the metallization solution is acidic. In combination with the method of the present invention, this metallization solution surprisingly requires significantly lower concentrations of palladium ions compared to conventional prior art metallization solutions, but without compromising the metallization result/quality in the context of the present invention.

Alternatively, an autocatalyst wherein the first metallization solution in step (B) comprises a reducing agent, preferably comprises one or more species of transition metal ions, more preferably comprises copper ions and/or nickel ions. The method of the invention (for metallization), which is a type metallization solution, is preferred.

However, regardless of what type the first metallization solution is, it is preferably a clear, particle-free solution.

Preference is given to the process of the invention (for metallization) comprising the following steps:

(A) providing a non-conductive or carbon fiber-containing substrate having an activated surface for metallization obtained by the method of the present invention, preferably as defined as preferred throughout the specification;

(B) contacting the activated surface with a first metallization solution, which is an autocatalytic metallization solution containing copper ions and a reducing agent, such that a first metallization layer comprising copper or a copper alloy is deposited on the activated surface; metallizing the activated surface.

Alternatively, the method of the invention (for metallization) is preferred, comprising the following steps:

(A) providing a non-conductive or carbon fiber-containing substrate having an activated surface for metallization obtained by the method of the present invention, preferably as defined as preferred throughout the specification;

(B) a first metallization solution which is an immersion metallization solution comprising palladium ions (preferably as previously described) such that a first metallization layer comprising palladium is at least partially deposited on the activated surface; metallizing the activated surface by contacting the activated surface, and thereafter

(C) metallizing the first metallization layer by contacting the first metallization layer with a second metallization solution such that a second metallization layer is deposited on the first metallization layer.

Preference is given to the method of the present invention (for metallization), wherein the second metallization solution in step (C) comprises a reducing agent, preferably comprising a reducing agent and nickel ions.

Thus, in step (C) the second metallization layer comprises nickel; Preference is given to the method of the invention (for metallization), preferably a nickel or nickel alloy layer.

In other cases, however, the method of the invention (for metallization) is preferred, wherein the second metallization solution in step (C) comprises a reducing agent, preferably comprising a reducing agent and copper ions.

Thus, in step (C) the second metallization layer comprises copper; Preference is given to the method of the invention (for metallization), preferably a copper or copper alloy layer.

In other cases, the method of the present invention (for metallization) is preferred, wherein the second metallization solution in step (C) comprises a reducing agent, preferably comprising a reducing agent and cobalt ions.

Thus, in step (C) the second metallization layer comprises cobalt; Preference is given to the method of the invention (for metallization), preferably a cobalt or cobalt alloy layer.

In step (C) the second metallization layer begins to deposit within 8 seconds to 30 seconds, preferably 10 seconds to 25 seconds, most preferably 12 seconds to 20 seconds. this is preferable Most preferably, the second metallization layer comprises nickel; It is preferably applied in the case of a nickel or nickel alloy layer. Thus, the inventors' experiments show that the first metallization layer comprising palladium functions as a booster for the second metallization layer of nickel or nickel alloy.

The invention is illustrated in more detail by the following non-limiting examples.

Example

Test method:

Backlight test (metal coverage on substrate surface):

Coverage is evaluated using the industry standard backlight test, where each substrate is cut into sections so that areas of incomplete coverage can be detected as bright spots when viewed over a strong light source (US 2008/0038450 A1 and WO compare 2013/050332). The quality of coverage is determined by the amount of light observed under a conventional optical microscope. The results are given on a scale from D1 to D10, where D1 (little, incomplete coverage) means the worst result and D10 (complete, strong coverage) means the best result.

Solder Impact Test:

After electroless copper plating, the electrical reliability coupon was immersed in a 10% H ₂ SO ₄ solution at room temperature for 10 seconds and then 40 μm of copper was electrolytically plated on the coupon. The coupon is then annealed at 140°C for 6 hours, cooled to room temperature, and subjected to a solder impact test where the coupon is floated in molten solder at 288°C for 10 seconds and then allowed to cool back to room temperature. . This plotting and cooling procedure was repeated 5 additional times.

Peel strength:

The electroless plated ABF coupon was immersed in a 10% H ₂ SO ₄ solution at room temperature for 10 seconds and then electrolytically plated with 35 μm copper. After plating, the coupons were fully cured according to Ajinomoto recommendations. The coupons were then cut into 1 cm wide strips using a routing machine. The force required to peel the copper film from these strips was measured using an Erichsen Unimat Plus 050-2kN material testing machine equipped with a 20N load cell, at a peel rate of 50.8 mm/min, always maintaining a peel angle of 90°. It became.

test coupon

Acrylonitrile butadiene styrene (ABS), FR4 and laminated Ajinomoto build-up film (ABF) GX-92R test coupons (Table 1) were used to evaluate the quality of the electroless copper deposits. The parameters tested were appearance, blistering, deposition thickness, coverage, electrical reliability and peel strength.

ABF lamination conditions

ABF GX-92R prepreg was applied to a Dynachem VA 7124-HP6 vacuum laminator (lamination conditions: 30 sec vacuum time, 30 sec dynamic slap down time, 20 sec static slap down time, 2.0 mbar vacuum set point, 5.0 kg/cm² pressure). was laminated onto Bondfilm ^® -treated copper clad FR4 panels using The laminated panels were then semi-cured in an air circulation oven according to Ajinomoto recommendations.

Desmear conditions

Coupons requiring desmear were desmeared using the Securiganth ^® series treatment baths listed in Table 2.

example of invention

Coupons were processed according to the conditions detailed in Table 3.

The following results were yielded:

· Electroless copper deposit appearance: salmon pink, no blisters

· Deposition thickness: 1 μm

· Backlight test performance: D9-D10

· Solder Impact Test Performance: 0% Interconnect Defect (ICD) after 6 shocks (10 seconds each) at 288°C

· Peel Strength: 8 N/cm

Comparative Example 1 (commercial palladium-based method)

Coupons were processed according to the conditions detailed in Table 4, which are representative of commercially used palladium-based processes.

The following results were yielded:

· Electroless copper deposit appearance: salmon pink, no blisters

· Deposition thickness: 1 μm

· Backlight test performance: D9-D10

· Solder Impact Test Performance: 0% ICD after 6 shocks (10 seconds each) at 288°C

· Peel Strength: 8 N/cm

Comparative Example 2 (Palladium-free method with acidic acidic selector treatment)

The coupons were treated according to the conditions detailed in Table 5, i.e., under the same conditions as the inventive example, but treated with an acidic selective agent.

The following results were yielded:

· Electroless copper deposit appearance: salmon pink, no blisters

· Deposition thickness: 1 μm

· Backlight test performance: D5-D7

Due to poor backlight test performance, solder impact and peel strength test performance were not investigated.

Comparative Example 3 (palladium-based method)

Coupons were processed according to the conditions detailed in Table 6.

The following results were yielded:

· Electroless copper deposit appearance: salmon pink, no blisters

· Deposition thickness: 1 μm

· Backlight test performance: D9

· Solder Impact Test Performance: 9% ICD after 6 shocks (10 seconds each) at 288°C

Due to the relatively poor solder impact test performance, the peel strength test performance was not investigated.

Comparative Example 4 (palladium-based method)

Coupons were treated according to the conditions detailed in Table 7, i.e., under the same conditions as Comparative Example 3, but without pre-dip.

The following results were yielded:

· Electroless copper deposit appearance: salmon pink, no blisters

· Deposition thickness: 1 μm

· Backlight test performance: D6-D7

· Solder Impact Test Performance: 25% ICD after 6 shocks (10 seconds each) at 288°C

Due to poor backlight and solder impact test performance, the peel strength test performance was not investigated.

Claims (14)

As a method for treating the surface of a non-conductive or carbon fiber-containing substrate,
(I) conditioning the surface of the non-conductive or carbon fiber-containing substrate, the conditioning method comprising:
(a) providing the substrate;
(b) providing a conditioning composition comprising a nitrogen containing compound; and
(c) contacting the substrate with the conditioning composition.
Including, the step of conditioning;
(II) a step of subjecting the surface of the non-conductive or carbon fiber-containing substrate to a selector treatment, comprising:
(a) providing said substrate treated according to step (I);
(b) (i) contains a nitrogen-containing compound;
(ii) having a pH of 9 to 14
providing a selector composition; and
(c) contacting the substrate with the selector composition
Including, processing the selector; and
(III) activating the surface of the non-conductive or carbon fiber-containing substrate for metallization, wherein the activating method comprises:
(a) providing said substrate treated according to step (II);
(b) providing a palladium-free activating composition;
(i) dissolved transition metal ions of the first type and further metal particles thereof;
(ii) one or more complexing agents, and
(iii) permanently or temporarily at least one reducing agent, and
(iv) optionally contains at least one dissolved metal ion of a second species different from said first species;
here
- dissolved transition metal ions and metal particles thereof, of at least the first species, are in reversible equilibrium, provided that
- said metal particles are formed from said dissolved transition metal ions via continuous or semi-continuous reduction with said at least one reducing agent;
- the dissolved transition metal ions are formed from the metal particles through continuous or semi-continuous oxidation of the particles;
- providing said palladium-free activating composition wherein said dissolved transition metal ion and its metal particles are each repeatedly involved in said reduction and said oxidation so that no precipitated agglomerates of said metal particles are formed; and
(c) the activating step comprising contacting the substrate with the activating composition such that a transition metal or transition metal alloy is deposited on the surface of the substrate and an activated surface for metallization is obtained.
A method for treating a surface comprising a. According to claim 1,
A method for treating a surface, wherein during and/or after step (III)(c) a majority of the metal particles are subjected to the oxidation. According to claim 1 or 2,
wherein the first species is copper or cobalt, preferably copper. According to any one of claims 1 to 3,
wherein the first type of metal particles in the activating composition are colloidal metal particles. According to any one of claims 1 to 4,
wherein the metal particles of the first type are continuously or semi-continuously formed in situ in the activating composition by the reduction after and/or during at least one step (III)(c) has been performed. way for. According to any one of claims 1 to 5,
The method of claim 1 , wherein the at least one reducing agent comprises a boron-containing reducing agent, preferably a borohydride. According to any one of claims 1 to 6,
The activating composition is substantially free of or free of tin ions, preferably substantially free of or free of tin ions, lead ions, germanium ions, gallium ions, antimony ions, bismuth ions and aluminum ions, more preferably A method for treating a surface, preferably substantially free of or free of metal ions of groups III, IV and V of the Periodic Table of the Elements. According to any one of claims 1 to 7,
wherein the activating composition is substantially free of or does not include a compound that prevents oxidation of the metal particle and/or is substantially free of or does not include a stabilizer compound for stabilizing the metal particle. According to any one of claims 1 to 8,
The at least one reducing agent is continuously or semi-continuously added to the activating composition so that additional metal particles are continuously or semi-continuously respectively formed from the dissolved transition metal ions of the first species, preferably at least one A method for treating a surface, added after step (III)(c) has been performed. According to any one of claims 1 to 9,
wherein the dissolved transition metal ions are formed from the metal particles through oxidation by ambient air and/or oxygen gas. A method for metallizing an activated surface of a non-conductive or carbon fiber-containing substrate, the method comprising:
(A) providing said non-conductive or carbon fiber-containing substrate with said activated surface for metallization obtained by the method according to any one of claims 1 to 10; and
(B) metallizing the activated surface by contacting the activated surface with a first metallization solution such that a first metallization layer is deposited on the activated surface.
A method for metallizing an activated surface comprising: A method for preparing an aqueous, palladium-free activating composition for activating the surface of a non-conductive or carbon fiber-containing substrate for metallization, the method comprising:
(1) - a dissolved transition metal ion of the first kind, and
- at least one complexing agent, and
- optionally, at least one dissolved metal ion of a second species different from said first species
Providing a starting aqueous solution comprising; and
(2) finally continuously or semi-continuously adding one or more reducing agents to the starting solution such that metal particles of the first species of dissolved transition metal ions are continuously or semi-continuously respectively formed in the solution. do,
provided that the metal particles are continuously or semi-continuously oxidized to form dissolved transition metal ions of the first species, the method comprising the aqueous, palladium-free activating composition according to any one of claims 1 to 10 A process for preparing an aqueous, palladium-free activating composition used to provide As a selector composition,
(i) a) a first nitrogen-containing compound selected from ammonia, monoethanolamine, triethanolamine or mixtures thereof; and
b) a second nitrogen-containing compound selected from guanidine, guanidine compounds such as guanidinium salts, or mixtures thereof
contains;
(ii) a selector composition having a pH of 9 to 12. According to claim 13,
The concentration of the first nitrogen-containing compound in the selector composition is 1 g/L to 50 g/L, preferably 2 g/L to 40 g/L, more preferably 3 g/L to 35 g/L, more preferably 5 g/L to 30 g/L,
The concentration of the second nitrogen-containing compound in the selector composition is 1 g/L to 10 g/L, preferably 2 g/L to 8 g/L, more preferably 3 g/L to 7 g/L, More preferably 4 g / L to 6 g / L, the selector composition.