WO2018141769A1

WO2018141769A1 - Additive for lds plastics

Info

Publication number: WO2018141769A1
Application number: PCT/EP2018/052347
Authority: WO
Inventors: Helge Kniess
Original assignee: Merck Patent Gmbh
Priority date: 2017-02-03
Filing date: 2018-01-31
Publication date: 2018-08-09

Abstract

The present invention relates to an LDS-active additive for LDS plastics, to a polymer composition containing such an additive, and to an article having metalized conductive tracks, a polymeric base of the article or a polymeric coating on a base containing an LDS additive of said type.

Description

Additive for LDS plastics

The present invention relates to an LDS-active additive for LDS plastics, and more particularly to the use of pigments comprising a substrate and a coating disposed on the substrate, the coating comprising iron in the oxidation states (0) and / or (II) contains, as LDS additive in polymer compositions, which are used for an LDS process, on a polymer composition containing such an additive, and on an article with metallized conductor tracks, in which a polymeric body of the article or a polymeric Coating on a base body contains an LDS additive of the type mentioned.

Three-dimensional plastic components that carry circuits, so-called MIDs (Molded Interconnect Devices) have been established on the market for years and have contributed significantly to enabling state-of-the-art technologies in many applications, such as in telecommunications, automotive or medical technology. Likewise, they make a significant contribution to the miniaturization and complexity of the individual electronic components in such applications.

For the production of three-dimensional MIDs, there are various methods by which obtained for example by means of 2-component injection molding or hot stamping basic components made of plastic or with

plastic-containing coating with the necessary switching structures are provided. As a rule, this requires product-specific special tools that are expensive to purchase and inflexible in use.

In contrast, the LPDS-developed LDS process (laser direct structuring method) offers the decisive advantage that the circuit structures can be directly and individually adapted to the plastic base part or the plastic-containing coating by means of a laser beam the base part can be cut and then metallized. For the production of the plastic base parts simpler methods, such as the 1-component injection molding process are suitable and the cutting of the circuit structures can also be controlled three-dimensionally.

In order to be able to obtain metallizable circuit structures by laser beam, a so-called LDS additive must be added to the plastic base part or the plastic-containing coating. This must be on

Laser radiation react while preparing the subsequent metallization. The LDS additive is generally metal compounds that are activated during processing with the laser beam on the surfaces machined by the laser in such a way that metal nuclei are released, which are the subsequent attachment of electrically conductive metals for the formation of electrical circuits to the activated Favor digits in the plastic. At the same time, these metal compounds react laser-active (usually laser-absorbing) and cause the plastic on the surfaces machined by the laser to be ablated and carbonized, so that a circuit structure is engraved into the plastic base part. At the points not activated by the laser in the plastic, the metal compounds remain unchanged. The LDS additives can either be added to the plastics material as a whole prior to deformation to the plastic base part or only as a component in a separate plastic-containing layer, a coating, a lacquer layer on the surface into which the circuit structure is to be cut by laser. or the like.

During laser beam processing, in addition to the future circuit structure, which contains metal nuclei, a microrough surface is also created within the circuit structure, which creates the prerequisite for the conductive metal, as a rule, to be Copper, during the subsequent metallization adherent to the plastic can anchor.

The metallization is then usually carried out in electroless copper baths, which can be followed by another application of nickel and gold layers, also in electroless baths. However, other metals such as tin, silver and palladium may also be applied, optionally in combination with, for example, gold. Subsequently, the pre-structured plastic components are equipped with the individual electronic components.

The objective of the LDS procedure is to have two or three

To produce three-dimensional electrically conductive switching structures on two- or three-dimensional plastic basic bodies or bodies with plastic-containing coating. It goes without saying that for this purpose only the metallized produced

Switching structures may have an electrical conductivity, but not the plastic base body or the coating itself. As LDS additives were therefore proposed in the past usually additives that do not even have an electrical conductivity and the base material does not impart such.

Originally, non-conductive organic heavy metal complexes were provided as LDS additive, which are especially palladium-containing (EP 0 917 597 B1).

In EP 1 274 288 B1, plastics are added as an LDS additive to non-conductive inorganic metal compounds which are not soluble in the application medium and which are inorganic metal compounds of metals of the d and f groups of the periodic table with nonmetals. Preference is given to using copper compounds, in particular copper spinels. Organic Pd complexes, or copper spinels, also have a dark inherent color and also impart a dark color to plastics that contain them. In addition, in particular the copper compounds cause a partial degradation of the surrounding plastic molecules. Of course, the degradation of the plastic base is undesirable.

In order to make plastics having a light inherent color accessible to the LDS process, WO 2012/126831 has proposed LDS-compatible plastics and a corresponding LDS process in which an LDS additive containing antimony-doped tin dioxide is added and in the ClELab color space has an L ^* value (brightness) of at least 45. Preferably, it is doped with antimony

Zinndioxid coated mica in amounts of 2 to 25 wt.%, Based on the total plastic composition used.

Modern plastics used for the LDS process are often filled with fillers. In particular, they are reinforced with optical fibers to set advantageous mechanical properties. However, it has been found that various LDS additives reduce the mechanical strength that is achieved by glass fibers, because they have such a high intrinsic hardness that the glass fibers are damaged or even destroyed in the polymer composition. For this reason, EP 2 676 799 A1 has proposed a thermoplastic resin composition for use in the LDS process, in which materials containing at least one element selected from copper, antimony and tin and a Mohs hardness are used as the LDS additive which is at least 1, 5 lower than the Mohs hardness of the added inorganic fibers, which is usually to

Glass fibers acts. However, the addition of copper-containing compounds can lead to a degradation of the plastic matrix, as already described above.

The use of antimony is subject to administrative restrictions in some countries, because it fears environmental damage, which could occur in particular in the manufacture or recycling of the corresponding compounds or components containing them.

The same restrictions apply country-specifically in part to compounds containing other heavy metals.

Although there is no fear of environmental damage from the use of tin, its availability on the world market is declining because natural supplies are limited and recycling products can not be used everywhere. There was therefore still a need for LDS additives, all

Meet requirements for a good metallizability and a high mechanical strength of the plastic compositions provided therewith when used in the LDS process and at the same time are not subject to any restrictions in terms of availability of raw materials or administrative application restrictions. Of course, all requirements for an LDS additive must be complied with, namely the activability by laser radiation, the release of metal nuclei by the laser bombardment and the formation of a microrough surface by the laser beam as the basis for the subsequent metallization.

The object of the present invention is therefore to provide an LDS additive for LDS plastics available, which is free of antimony, tin and copper, can be used in glass fiber reinforced plastic compositions without mechanical impairment of the glass fibers and beyond a good metallization of the circuit structures available in the LDS method when using the widest possible range of laser parameters. Another object of the present invention is to provide a polymeric composition which is suitable for the LDS process and has the properties described above. An additional object of the present invention is to provide articles having a circuit structure produced by the LDS method and having the above-mentioned characteristics.

The object of the present invention is achieved by the use of pigments which have a substrate and a coating located on the substrate, wherein the coating contains iron in the oxidation state (0) and / or (II), as LDS additive (Laser direct structuring additive) in a polymeric composition. Furthermore, the object of the present invention is also achieved by a polymeric composition comprising at least one polymeric plastic and an LDS additive, wherein the LDS additive

Contains pigments which are a substrate and a thereon

Coating, wherein the coating iron in the

Oxidation level (0) and / or (II) contains.

In addition, the object of the invention is achieved by an article having a circuit structure produced in an LDS method, consisting of a plastic base body or a plastic-containing coating having body and on the surface of the

Base body or the coating located metallic interconnects, wherein the plastic base body or the plastic-containing coating of the base body contains an LDS additive containing pigments having a substrate and a coating thereon, wherein the coating iron in the oxidation state (0) and / or (II). Pigments comprising a substrate and a coating on the substrate, the coating containing iron in the oxidation state (0) and / or (II), are known per se. For example, US Pat. No. 4,867,793 describes colored effect pigments

described which have a compact coating on a platelet-shaped substrate containing iron (II) oxide. These pigments have a high gloss and, depending on the layer thickness of the coating, an interference color. The iron (II) oxide-containing coating can be prepared by reducing a Fe 2 O 3 layer previously deposited on the substrate.

From WO 2007/000253 A2, pigments are known which comprise a substrate and a coating located on the substrate, the coating containing metallic iron. The pigments have a gray-black body color, a high gloss and an interference color and can be used in a wide variety of applications, including laser marking of plastics. The usual laser marking of plastics, however, differs significantly from the laser processing of plastics in the LDS process. In conventional laser marking, a laser-absorbing additive absorbs the energy of the laser beam and releases it to the surrounding plastic matrix, so that the latter is either foamed or carbonized, which produces the desired laser marking. In this case, the surface of the plastic body, if no Ablatierung the surface is desired to remain undamaged and the marking only inside the

Plastic body can be generated below the surface. The energy required for the process of the laser beam is adjusted accordingly.

In the generation of switching structures by means of a laser beam in the LDS method, however, the future switching structure using the Engraved laser beam into the surface of the corresponding body and at the same time a rough surface structure and metal nuclei are generated, which allow the subsequent attachment of pure metals in the metal bath (plating). The generation of such surface structures must be possible over a wide range of laser parameters and the corresponding subsequent metallization sufficiently strong to

Lead structure for microelectronics in question at all.

In addition, the plastic bodies provided with the laser-absorbing additives should not have a large-area electrical conductivity. Therefore, specially developed additives are regularly used for the application in the LDS process.

Surprisingly, it has now turned out, however, that pigments comprising a substrate and a coating located on the substrate, wherein the coating contains iron in the oxidation state (0) and / or (II), as LDS additive in a polymeric Composition are very suitable.

The present invention therefore relates to the use of said pigments as LDS additive in polymeric compositions for use in the LDS process.

For use as pigment substrates according to the invention such materials are selected which have a low intrinsic hardness and thereby contribute to a low mechanical stress on the preferably glass-fiber reinforced plastics in which the LDS additives according to the present invention are to be used. Suitable materials for this purpose are those which have a Mohs hardness of less than 5, for example natural or synthetic mica, talc, kaolin, graphite, wollastonite and BiOCl. Except for wollastonite

Pigment substrates of this type are known for use in effect pigments. In principle, the shape of the pigment substrates for the use of resulting LDS additives not critical and may be spherical, platelet-shaped, needle-shaped, fibrous or regular or

be irregularly granular. However, platelet-shaped substrates are preferred because of better availability.

However, substrates of natural or synthetic mica, of talc, kaolin or graphite, or mixtures of two or more of these substrates are particularly preferred because of their particularly low Mohs hardness. All of these substrates are also available in platelet form in the market.

Very particular preference is given to substrates of natural or synthetic mica, talc or kaolin, and mixtures of at least two of these.

The proportion by weight of the substrate should be at least 50% by weight, based on the total weight of the pigment. It is according to the invention at 50 to 99 wt.%, In particular at 60 to 99 wt.%, Particularly preferably at 65 to 99 wt.%, Each based on the total weight of the pigment.

Accordingly, the proportion of the coating according to the invention is 1 to 50 wt.%, In particular 1 to 40 wt.% And particularly preferably 1 to 35 wt.%, Based on the total weight of the pigment.

The coating of the LDS additive pigments used according to the invention can be composed differently.

In a first embodiment of the present invention, the coating contains iron in the oxidation state (0) as the sole iron component. Accordingly, iron is present in the coating exclusively in metallic form. Pigments of this type can analogously to those in WO 2007/000253 A2 are described. For this purpose, a substrate coated with iron oxide, preferably Fe 2 O 3, or the corresponding hydrated oxide is treated in a reducing gas atmosphere at a temperature of> 700 ° C reducing until the total amount of iron oxide or Eisenoxidhydrates is reduced to metallic iron. As reducing gases pure nitrogen as well as mixtures of hydrogen and nitrogen are suitable. When using a mixture of hydrogen and nitrogen, a hydrogen content of 4 to 20% by volume, in particular from 5 to 8% by volume, has proven particularly suitable. The presence of pure carbon, preferably in the form of graphite or carbon black, in the reduction process may favor the formation of the metallic iron in the coating of the LDS additive pigment according to the invention. The carbon may be present as a graphite substrate, as a carbonaceous layer on the substrate between substrate and iron oxide-containing layer or on the iron oxide-containing layer, in the form of particulate carbon black in the iron oxide-containing layer or in the reduction process in addition to the iron oxide. coated

Substrate added particulate carbon black may be present. The proportion by weight of pure carbon in the total solids mass in the reduction process can be in the range from 0 to 50% by weight, in particular from 0.5 to 40% by weight.

In a second embodiment of the present invention, the coating contains iron in the oxidation state (II) as the only iron component. In the present invention, iron is considered to belong to the oxidation state (II) when it is present in a compound in the oxidation state range of 1.94 to 2.0. Consequently, all connections in the range from Feo.97O to FeO are included here. Again, the corresponding pigments can be prepared according to the method described in WO 2007/000253 A2. At a temperature of> 700 ° C is a with

Iron (III) oxide or the corresponding oxide hydrate coated substrate treated reducing until the total amount of iron oxide or Oxidhydrates is reduced to iron (II) oxide. Pure nitrogen is used here preferably as a reducing gas, although in principle a mixture of hydrogen and nitrogen, as described above, is suitable. The reduction time is shortened accordingly compared to the reduction to pure metallic iron. Again, the presence of pure carbon in the reduction process, in one of the above forms, has proved to be advantageous.

In a third embodiment of the present invention, the coating contains iron in the oxidation states (0) and (II). Pigments of this composition can be prepared in a simpler manner than the pigments according to the abovementioned two embodiments, because the

Reaction conditions in the reduction need not be strictly regulated to the same extent as in the production of iron in the

Oxidation levels (0) or (II) in pure form in the pigment coating. Instead, mixtures of Fe (0) and Fe (II) in the coating can be produced in a simpler manner. In addition, it has been found that pigments containing in their coating both metallic iron in the oxidation state (0) and iron in the oxidation state (II), as a LDS additive better metallization of the laser-preformed conductor tracks on the treated Plastic bodies allow. For this reason, the third embodiment in which the coating of the pigments contains iron in the oxidation states (0) and (II) is preferred.

As already described above, the pigments of the third embodiment can also be described by the process described in WO 2007/000253 A2

Produce process. The reduction temperature is set in the range of 650 to 850 ° C. The annealing time is between 30 and 120 minutes, preferably between 30 and 90 minutes. With regard to the composition of the reducing gases and the presence of carbon in the reduction process, the statements made above apply analogously. In a fourth embodiment, the pigment used as LDS additive according to the present invention may additionally contain iron in the oxidation state (III) in the coating. This can be present either in combination with iron in the oxidation state (0) or in combination with iron in the oxidation state (II) or in combination with iron in the oxidation states (0) and (II) in the coating. Iron in the oxidation state (III) occurs in the form of the oxidic compounds Fe 2 O 3, Fe 3 O ₄ or in the form of FeO (OH). These forms are obtained in the reduction process in particular when the reduction conditions are set such that a complete transfer of

Iron (III) oxide or oxide hydrate in Fe (0) or Fe (II) does not occur or the formation of Fe3O ₄ is favored. The presence of iron in the oxidation state (III), in particular in the form of Fe3O ₄ (a mixed oxide of Fe (II) O and Fe (III) 2O3) does not interfere with the suitability of the pigments used in the invention as LDS additive, as long as Fe (0 ) and / or Fe (II) are present in a sufficient amount in the coating of the pigments, the latter being already ensured via iron of the oxidation state (II) in Fe 3 O ₄ . Therefore, pigments of the fourth embodiment are also preferably used as LDS additive.

As already described above, the weight fraction of the coating in the pigment used according to the invention is 1 to 50% by weight, preferably 1 to 40% by weight and in particular 1 to 35% by weight, based on the total weight of the pigment.

The coating can be single-layered or multi-layered, in particular one or two-layered, on the substrate.

If the coating is single-layered, it can be iron in the

Oxidation state (0) to 100 wt.% Or iron in the oxidation state (II) to 100 wt.% (First and Second Embodiments). According to the third and partially of the fourth embodiment is

at least one mixture of iron in the oxidation state (0) and iron in the oxidation state (II) in the coating present. In this case, the proportion by weight of iron in the oxidation state (0) in the

Coating according to the invention in the range of 10 to 95 wt.%, And the proportion of iron in the oxidation state (II) at 5 to 90 wt.%, Based on the weight of the coating. Of course, the total weight of the coating in each case 100 wt.%, Even if in addition to iron in the oxidation states (0) and (II) iron in the oxidation state (III) is present in the coating.

If a mixture of iron in the oxidation states (0) and (II) in the coating before, it is advantageous if the proportion by weight of iron in the oxidation state (0) is comparatively high and in particular greater than the proportion by weight of iron in the oxidation state ( II), in each case based on the total weight of the coating.

If the iron-containing coating of the pigment used according to the invention is multi-layered, in particular two-layered, it preferably consists of one or more iron-free layer (s) and an iron-containing layer which is located on the substrate as the uppermost layer of the layer sequence. Between the substrate and the iron-containing layer are therefore still one or more iron-free

Intermediate layers, in particular of metal oxides. This intermediate layer (s) can be used to adjust the color properties of the pigments used according to the invention, to improve the adhesion of the iron-containing layer or to introduce carbon into the pigment body. As possible layer materials, various metal oxides such as, for example, S1O2, Al2O3, T1O2, SnO2, ZrO2 or Cr2O3 are suitable. However, these metal oxides each have rather high Mohs hardness, so that the total layer thickness of the intermediate layer (s) should not exceed 100 nm as possible, that is at 1 to 100 nm, in particular 1 to 50 nm, should, with a high proportion by weight of the substrate of preferably> 60 wt.%, Based on the total weight of the pigment. Also, in the case of the existence of intermediate layers and in the presence of Fe (0) and Fe (II) in the coating, the weight ratio of iron in the oxidation state (0) is from 10 to 95% by weight and the proportion by weight of iron in the oxidation state (II) from 5 to 90% by weight, based in each case on the total weight of the coating.

The pigments used according to the invention preferably have at most one, in particular no, iron-free intermediate layer.

Particularly preferred is therefore an LDS additive according to the present invention, which consists of a substrate of natural or synthetic mica, talc, kaolin or graphite, or a mixture of two or more of these substrates, and a single-layer

Coating containing iron in the oxidation state (0) and / or (II).

Particularly preferred is an LDS additive according to the present invention, which consists of a substrate of natural or synthetic mica, talc or kaolin, or a mixture of at least two of these substrates, and a single-layer coating, which iron in the oxidation state (0 ) and / or (II).

The layer thickness of the iron-containing coating which contains iron in the oxidation state (0) and / or (II) on the substrate of the pigment is in the range from 1 to 300 nm, in particular in the range from 1 to 100 nm. The pigments used according to the invention as LDS additive have particle sizes in the range from 1 to 100 μm, preferably in the range from 1 to 50 μm, and in particular in the range from 1 to 30 μm. Particular preference is given to pigments having particle sizes in the range from 1 to 30 μιτι, in which the dgs value is less than 15 μιτι. A dgs value of <15 μιτι means that 95 vol.% Of the particles of a pigment bed have a particle size of less than 15 μιτι. Preferably, the corresponding dso value is <10 μιτι.

The specified particle sizes can be determined by conventional methods for particle size determination. Particularly preferred is a method for particle size determination according to the laser diffraction method, in which advantageously both the nominal particle size of the individual particles and their percentage particle size distribution can be determined. Preferably, a Malvern 2000 device from Malvern Instruments Ltd., UK is used under standard conditions of ISO / DIS 13320. The described, provided with an iron-containing coating

Pigments in which iron in the oxidation state (0) and / or (II) is contained in the respective polymeric composition as LDS additive in an amount of 0.1 to 30 wt .-%, preferably from 0.5 to 15 wt .-%, and in particular> 1 to 10 wt .-%, each based on the total weight of the polymeric composition containing. They may also be used in blends with other LDS additives known in the art in the LDS-enabled polymeric composition. In the latter case, the proportion of inventive LDS additive is reduced by the proportion of the other or the other LDS additive. In sum, the proportion of LDS additives is usually not more than the above-mentioned 30 wt .-%, based on the total weight of the LDS-capable polymeric composition. Preferably, the with pigments containing iron in the oxidation state (0) and / or (II) are used as sole LDS additive in the LDS-suitable polymeric compositions. The polymeric composition can be either a thermoplastic polymeric composition or a thermoplastic polymer composition

thermosetting polymeric composition. Depending on the desired application of the polymeric LDS-suitable materials, either the thermoplastic or the thermosetting composition may be preferred in each case.

The polymeric compositions are composed to a predominant proportion (usually> 50 wt .-%) of thermoplastic or thermosetting plastics.

Suitable thermoplastics are amorphous and semi-crystalline thermoplastics in a wide range of materials, such as various polyamides (PA), polycarbonate (PC), polyphthalamide (PPA), polyphenylene oxide (PPO), polybutylene terephthalate (PBT), cycloolefin polymers (COP), polyaryl ethers - ketones, such as Polyetheretherketone (PEEK), liquid crystal polymers (LCP) or their copolymers or blends, such as acrylonitrile-butadiene-styrene / polycarbonate blend (PC / ABS) or PBT / PET. They are suitable by all well-known polymer manufacturers

Qualities offered.

As thermosetting plastics in particular different polyurethanes, melamine resins, phenolic resins, polyesters and epoxy resins are suitable.

However, the LDS additive pigments used according to the invention are very particularly suitable as LDS additives in glass fiber-reinforced materials

Plastics because, despite the iron-containing coating, they do not mechanically attack or destroy the glass fibers they contain LDS use, the positive mechanical properties of glass fiber reinforced plastics can be maintained. As glass fibers, all can usually be used in the production of polymers

Plastic articles used glass fibers, regardless of their concrete material composition, size and shape, are used. The glass fibers, as well as the polymeric materials for the polymeric compositions, are commercially available from a variety of manufacturers. The incorporation of the LDS additives described in the invention into the polymeric composition can be carried out, for example, by compounding, masterbatches, pastes or by direct addition in the shaping processing step. In addition, the polymeric compositions which contain the pigments used according to the invention as LDS additive may optionally additionally contain further fillers and / or colorants as well as stabilizers, auxiliaries and / or flame retardants. Suitable further fillers are, for example, various silicates, S1O2, talc, kaolin, mica, wollastonite, glass beads, carbon fibers or the like.

Suitable colorants are both organic dyes and inorganic or organic color pigments. They serve to change the color or the lightening of the polymeric plastic compositions, which have a rather dark color due to the inventive use of iron-containing pigments as LDS additive depending on the percentage content. As examples, only the most commonly used white pigments ΤΊΟ2, ZnO, BaSO ₄ and CaCO3 are mentioned here. The amount and type of added fillers and / or colorants is only by the particular concrete material condition the individual LDS-suitable compositions, in particular of the plastics used, limited.

It has surprisingly been found that the iron-containing pigments used according to the invention are very well suited as LDS additives and also in the polymer compositions added thereto for the LDS process at a customary use concentration of 0.1 to 30% by weight % do not lead to the formation of electrical conductive paths in the polymeric body or the polymer-containing coating on the body of the article to be produced, although the pigments as such have at least partially their own electrical conductivity. Therefore, the polymeric compositions provided with the LDS additive used according to the invention are also suitable for applications in the high-frequency range. At the same time, the LDS additives used according to the invention have a high laser activity and lead to the desired microrough surfaces within the ablated and carbonized by the laser beam line structures when laser action according to the LDS method, so that a subsequent

Metallization in good quality is possible. Very good metallizability is possible with a wide range of different laser settings. Thus, for the LDS method, the conditions that are most suitable for the laser action which are actually present can be selected in each case without any quality dips being to be expected in the subsequent metallization. Moreover, their use as LDS additive in plastic-containing polymeric compositions also does not result in degradation of the organic polymer molecules surrounding the LDS additives. In addition, the pigments used are free of antimony, tin and copper and are particularly suitable for use in glass fiber reinforced polymeric compositions.

The present invention also provides a polymeric composition which comprises at least one polymeric plastic and one LDS Additive contains, wherein the LDS additive contains pigments, which have a substrate and a coating thereon, wherein the coating iron in the oxidation state (0) and / or (II) contains. The polymeric composition according to the invention contains the LDS additive in a proportion of 0.1 to 30 wt .-%, preferably from 0.5 to 15 wt .-%, and in particular> 1 to 10 wt .-%, based on the

Total weight of the polymeric composition. In particular, in addition to the polymeric plastic and the LDS additive, the polymeric composition additionally contains glass fibers as filler. The material composition, shape, size and amount of glass fibers depends on the desired mechanical

Properties of the polymeric compositions and can from

Be professionally selected according to his general knowledge in this regard.

Details regarding the material composition of the LDS additive, the polymer materials used and, if appropriate, further existing auxiliaries and additives such as fillers, colorants and the like have already been described above. This is referred to here.

The polymeric composition according to the invention is intended for use in an LDS process (laser direct structuring method) for the production of metallized switching structures on two- or three-dimensional plastic basic bodies or two-dimensional or three-dimensional basic bodies bearing plastic-containing coatings. It is well suited for use in high-frequency applications and, due to the addition of the LDS additive according to the invention, effects a good metallizability of the laser structures generated by line structures, wherein the laser parameters can be selected in a broad spectrum. The added LDS additive is free of antimony, tin and copper, so that no chemical interference by degradation of the polymer matrix must be feared. In addition, despite the presence of iron in different oxidation states in the coating of the LDS additive pigments also no mechanical impairment of glass fiber reinforced polymer compositions takes place.

The subject matter of the present invention is also an article with a circuit structure produced in an LDS method, the article consisting of a polymer base body or a polymer-containing base body of the article and of metal conductor tracks which lie on the surface of the article Base body or on the surface of the polymer-containing coating of the base body are, wherein the polymeric base body or the polymer-containing coating of the base body contains an LDS additive containing pigments, which have a substrate and a coating thereon, wherein the coating Contains iron in the oxidation state (0) and / or (II).

Such articles, in particular articles made of organic thermoplastic or thermosetting plastics, find use, for example, in telecommunications, medical technology or in the automotive industry, where they are used for example as electronic components of mobile phones, hearing aids, dental instruments, automotive electronics and the like.

The present invention will be explained below by means of examples, but not limited to these.

Example 1 :

Preparation of a pigment with a weight fraction of the substrate of

50% by weight ^* : 100 g of mica with a particle size <15 μιτι are heated in 1, 9 I demineralized water with stirring to 80 ° C. The pH of the suspension is adjusted to 2.8 with 10% hydrochloric acid. Now 677 g of a 30% FeCb solution are metered in, wherein the pH is kept constant by simultaneous dropwise addition of a 32% sodium hydroxide solution. The product is filtered off, washed, dried and reduced at 700 ° C in a gas mixture of nitrogen and hydrogen (proportion of hydrogen: 5 vol.%). This gives a brownish-black pigment whose

Coating of 55 wt.% Fe, 40 wt.% FeO and 5 wt.% Fe3O ₄ consists.

* The weight fraction of the substrate is calculated in terms of the weight of the coating, calculated as Fe2Ü3

Example 2:

Preparation of a pigment with a weight fraction of the substrate of 67% by weight ^* :

100 g of mica with a particle size <15 μιτι be heated in 1, 9 I demineralized water with stirring to 75 ° C. The pH of the suspension is adjusted to 3.0 with 10% hydrochloric acid. Now 339 g of a 30% FeCl 3 solution are metered in, wherein the pH is kept constant by simultaneous dropwise addition of a 32% sodium hydroxide solution. The product is filtered off, washed, dried and reduced at 800 ° C in a gas mixture of nitrogen and hydrogen (proportion of hydrogen: 5 vol.%). A black pigment is obtained, the coating of which consists of 100% by weight of metallic iron.

Example 3:

Preparation of a pigment with a weight fraction of the substrate of 80% by weight ^* : 100 g of mica with a particle size <15 μιτι be heated in 1, 9 I demineralized water with stirring to 75 ° C. The pH of the suspension is adjusted to 3.0 with 10% hydrochloric acid. Now 169 g of a 30% FeCl 3 solution are metered in, wherein the pH is kept constant by simultaneous dropwise addition of a 32% sodium hydroxide solution. The product is filtered off, washed, dried and reduced at 750 ° C in a gas mixture of nitrogen and hydrogen (proportion of hydrogen: 5 vol.%). A black pigment is obtained, the coating of which consists of 95% by weight of Fe and 5% by weight of FeO.

Example 4:

Application as LDS additive:

By means of a co-rotating twin-screw extruder (Prism Eurolab, Thermo Scientific) 5 wt .-% of the LDS additive (pigment according to Example 1) in PC / ABS (Xantar C CM 406, Mitsubishi Engineering Plastics) incorporated. The metering of the previously ground polymer and the LDS additive takes place as a premix via the main hopper. The extruder has a screw diameter of 16 mm and an L / D ratio of 32. The extrudate is strand granulated and then dried at 100 ° C for 4 hours. Thereafter, test plates measuring 60 × 90 × 1.5 mm are injection-molded on an injection molding machine (Arburg Allrounder 320 M). The test plates contain the LDS additive homogeneously and finely distributed.

The test plates are processed with different laser power and frequency in the range of 3-16 W and 60-100 kHz in screened test fields by means of a 1064nm fiber laser, so that a low material removal occurs with simultaneous carbonation of the machined surface. Subsequently, the metallization with copper in a commercial reductive copper bath (MID Copper 100 B1, MacDermid). The metallization properties are judged by the structure of the copper layer on the substrate. The plating index (according to MacDermid) is given which results from the quotient of the built-up copper layer of the test material and the built-up copper layer of the reference material. As reference material are test plates made of PBT with a share of 5 wt .-% copper spinel (Comparative Example 1).

The results are shown in Table 1. Comparative Examples (Application):

Analogously to Example 4, 5% by weight of a pigment are incorporated as LDS additive into the PC / ABS test plates.

Comparative Example 1: Copper spinel

Comparative Example 2: Iriotec® 8825, [mica / (Sn, Sb) O2, Merck KGaA] The results are shown in Table 1.

Table 1 :

Laser adjustment plating index

Vergl.bsp.1 Vergl.bsp.2 Ex1

3W / 60 kHz 0.41 0.00 0.00

4W / 60kHz 0.56 0.00 0.25

5W / 60kHz 0.65 0.00 0.43

6W / 60 kHz 0.71 0.00 0.57

8W / 60 kHz 0.69 0, 15 0.56

4W / 80kHz 0.65 0.00 0, 14

6W / 80 kHz 0.83 0.00 0.64

8W / 80kHz 0.76 0.00 0.64

10W / 80kHz 0.73 0.00 0.49

12W / 80 kHz 0.70 0, 16 0.44

14W / 80 kHz 0.63 0.54 0.36

6W / 100 kHz 0.88 0.00 0.57

8W / 100 kHz 0.79 0.00 0.65

10W / 100kHz 0.70 0.00 0.49 12W / 100 kHz 0.68 0.00 0.43

14W / 100 kHz 0.72 0.34 0.35

16W / 100kHz 0.67 0.75 0.33

The experiments show that the pigment used according to the invention as an LDS additive with a coating containing Fe (O) and / or Fe (II) has distinctly better values with respect to the metallizability both in the width of the laser parameters and in terms of the nominal values of the plating index shows as the coated with antimony doped tin dioxide mica flakes according to Comparative Example 2, in which sensitivity is comparable to the copper spinel according to Comparative Example 1 and shows over the entire power range constant metallization.

Example 5:

Mechanical strength of the samples

Using a co-rotating twin-screw extruder (Prism Eurolab, Thermo Scientific) 5 wt.% Of the LDS additive (pigment according to Example 1) in PA6-GF30 (Durethan BG30X, Lanxess, 30% glass fibers / glass beads) is incorporated. The metering of the previously ground polymer and the LDS additive takes place as a premix via the main hopper. The extruder has a screw diameter of 16 mm and a L / D ratio of 32. The extrudate is strand granulated and then dried at 70 ° C for 24 hours. Thereafter, standard bodies (shoulder bar, type 1A, EN ISO 527-2, total length 170 mm, width at the ends 20 mm, width of the narrow parallel portion 10 mm, thickness 4 mm) are injection-molded on an injection molding machine. The shoulder bars contain the LDS additive homogeneously and finely distributed and can be used for tensile tests according to DIN EN ISO 527-2.

Same shoulder bars are used for the notched impact test by cutting a 10 in the middle of the parallel part by milling mm long notch brings. The introduction of the notch and the test is carried out according to DIN EN ISO 179-1.

Comparative Example 3

5% by weight of a copper spinel are incorporated as an LDS additive into PA6-GF30 in analogy to Example 5 and shoulder rods are produced therefrom.

As further comparative samples serve zero samples of the PA6-GF30 polymer in the following form:

Comparison A: Polymer without LDS additive, without extrusion, as delivered,

Comparative B: Polymer without LDS additive, extruded

The specimens are examined for their mechanical strength. The results are shown in Table 2. The following parameters are checked:

Type of test Standard Unit Test condition

Tensile modulus DIN EN ISO 527-2 / 1A MPa 1 mm / min

Breaking stress DIN EN ISO 527-2 / 1A MPa 5 mm / min

Elongation at break DIN EN ISO 527-2 / 1A% 5 mm / min Charpy

Notched impact strength DIN EN ISO-179-1 / 1 eA kJ / m ² 23 ° C Results of the test: Table 2

Comparison A Comparison B Comp.example.3 Ex.5

Pull-E module 6100 5600 5600 6200

Breaking stress 106 75 70 78 Elongation at break 2.7 1, 6 1, 5 1, 6 Charpy

Impact Strength 4 3.4 2.8 3.6 The results show that when using the pigment used according to the invention as an LDS additive with a coating containing Fe (0) and / or Fe (II) in glass fiber reinforced plastics, both a higher fracture stress and Charpy notched impact strength can be achieved with respect to mechanical strength. compared with the use of copper spinel. With regard to the train E modulus is

Example according to the invention comparable to the values that can be achieved with the extruded, unpigmented polymer.

When using copper spinel (Comparative Example 3) as LDS additive, however, as expected, a significant drop in stress at break and notched impact strength compared to Comparison B is observed, which is due to the damage and thus reduction of the glass fiber.

Claims

claims

1 . Use of pigments comprising a substrate and a coating located on the substrate, wherein the coating contains iron in the oxidation state (0) and / or (II), as LDS additive

(Laser direct structuring additive) in a polymeric composition.

Use according to claim 1, characterized in that the substrate is selected from the group consisting of natural mica, synthetic mica, talc, kaolin, graphite, wollastonite and BiOCl.

Use according to claim 1 or 2, characterized in that the substrate consists of natural or synthetic mica, talc, kaolin or graphite, or of a mixture of two or more thereof.

Use according to one or more of claims 1 to 3, characterized in that the proportion of the substrate is 50 to 99 wt .-%, based on the total weight of the pigment.

Use according to one or more of claims 1 to 4, characterized in that the coating iron in the

Contains oxidation state (0) as the sole iron component.

Oxidation stage (II) contains as the only iron component.

7. Use according to one or more of claims 1 to 4, characterized in that the coating iron in the

Contains oxidation states (0) and (II).

8. Use according to one or more of claims 1 to 7, characterized in that the coating additionally contains iron in the oxidation state (III).

5

9. Use according to one or more of claims 1 to 8,

characterized in that the weight fraction of iron in the oxidation state (0) in the coating is in the range from 10 to 95% by weight, based on the weight of the coating.

10.Verwendung according to one or more of claims 1 to 9,

characterized in that the proportion by weight of iron in the oxidation state (II) in the coating 5 to 90 wt.%, Based on the weight of the coating is.

The use according to one or more of claims 1 to 10, characterized in that the proportion by weight of iron in the oxidation state (0) is greater than the proportion by weight of iron in the oxidation state (II), based on the weight of the coating ,

12. Use according to one or more of claims 1 to 8,

20

characterized in that the pigments have a particle size in the range of 1 to 100 μιτι each.

13. Use according to one or more of claims 1 to 12, characterized in that the pigments in the polymeric

25 composition in a proportion in the range of 0.1 to 30 wt .-%, based on the total weight of the polymeric composition.

14. Use according to one or more of claims 1 to 13, characterized in that the polymeric composition in addition

30

the LDS additive contains at least one polymeric plastic.

15. Use according to claim 14, characterized in that the polymeric composition contains glass fibers as filler.

16. Use according to one or more of claims 1 to 15, characterized in that the pigment, which iron in the

Contains oxidation states (0) and / or (II) in the coating on a substrate, in admixture with other conventional LDS additives in the polymeric composition.

17. A polymeric composition containing at least one polymeric O.

Plastic and an LDS additive, the LDS additive containing pigments comprising a substrate and a coating thereon, the coating containing iron in the oxidation state (0) and / or (II). 5 18. Polymer composition according to claim 17, characterized

in that the LDS additive is contained in the polymeric composition in a proportion of 0.1 to 30% by weight, based on the total weight of the polymeric composition. 19. A polymeric composition according to claim 17 or 18, wherein

Glass fibers are included as a filler.

20. Polymeric composition according to one or more of

Claims 17 to 19, characterized in that it is in the polymeric composition to a thermoplastic material or5

a thermoset material.

21. Article with a circuit structure produced in an LDS method, consisting of a plastic base body or a main body having a plastic-containing coating and located on the surface of the main body or the coating

metallic conductor tracks, wherein the plastic base body or the plastic-containing coating of the base body an LDS additive containing pigments containing a substrate and a coating thereon, wherein the coating contains iron in the oxidation state (0) and / or (II).