EP2995178A1

EP2995178A1 - Additive for lds plastics

Info

Publication number: EP2995178A1
Application number: EP14726515.1A
Authority: EP
Inventors: Helge Bettina Kniess; Ulrich Quittmann; Oliver Robert PIENING; Silvia Rosenberger
Original assignee: Merck Patent GmbH
Current assignee: Merck Patent GmbH
Priority date: 2013-05-07
Filing date: 2014-05-05
Publication date: 2016-03-16
Also published as: CN105230133A; JP6423418B2; CN105230133B; WO2014180550A1; TW201510109A; KR20160005742A; DE102013007750A1; KR102171893B1; TWI632205B; JP2016520139A

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 composite pigments consisting predominantly of titanium dioxide and of antimony-doped

Zinndtoxid, 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 interconnects, 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.

There are various methods for producing three-dimensional MIDs, by means of which the basic components made of plastic or plastic-containing coating obtained, for example, by means of 2-component injection molding or hot stamping, are provided with the necessary switching structures. 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 are cut directly into the plastic base part or the plastic-containing coating on the base part by a laser beam and then metallized can be.

CONFIRMATION COPY 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 react to laser radiation and simultaneously prepare 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 in the plastic which are not activated by the laser, the metal compounds remain unchanged. The LDS additives can either be added to the plastic mass 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 surface on which the circuit structure is to be cut by laser beam Lackschicht, or the like, be present.

When working with the laser beam, in addition to the future circuit structure, which contains metal nuclei, a micro-rough surface within the circuit structure, which creates the condition that the conductive metal, as a rule, is

Copper, during the subsequent metallization adherent to the plastic can anchor. The metallization is then usually in electroless copper baths, which can be followed by another order of nickel and gold layers, also in electroless baths. However, it is also possible to apply other metals such as tin, silver and palladium, if appropriate in combination with, for example, gold. Subsequently, the thus pre-structured plastic components are equipped with the individual electronic components.

The objective of the LDS method is to produce three-dimensional electrically conductive switching structures on three-dimensional plastic basic bodies or basic bodies with plastic-containing coating. It goes without saying that for this purpose, only the generated metallized switching structures may have an electrical conductivity, but not the plastic base body or the

Coating itself. As additives in the past, therefore, additives have generally been proposed in the past which themselves do not have electrical conductivity and do not impart such to the base material. 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. However, organic Pd complexes or copper spinels have the

Disadvantage that they themselves have a dark inherent color and give plastics that contain them, also a dark color. Furthermore in particular, the copper compounds cause a partial degradation of the surrounding plastic molecules. Especially for MIDs that are to be used in telecommunications, however, there is an increased demand for plastics which have a light inherent color, so that they can be colored with all the desired colored shades without the addition of color pigments are made with such a large mass fraction must be such that the effectiveness of the LDS additives is disturbed or weakened. In addition, the degradation of the plastic base is undesirable.

In order to make plastics with a light inherent color available for the LDS process, therefore, EP 2 476 723 A1 has proposed tectoaluminosilicate (zeolites) as LDS additives for plastics. From WO 2012/126831 LDS-compatible plastics and a corresponding LDS method are known, wherein an LDS additive is added, which contains antimony-doped tin dioxide and in the ClELab color space an L * value (brightness) of at least 45 has. Preferably, mica coated with antimony-doped tin dioxide is used in amounts of from 2 to 25% by weight, based on the total plastic composition. Furthermore, white color pigments can additionally be added for an even lighter coloring of the plastics material.

WO 2012/056416 also discloses a composition which contains 0.5 to 25% by weight of a metal oxide-coated filler, the latter preferably being antimony-doped tin dioxide-coated mica. The LDS plastic compound has L ^* values of 40 to 85. The plastic material can also be added to color pigments.

Antimony doped tin dioxide coated mica platelets are commonly used as an electrically conductive pigment in a variety of applications. used fertilizer, for example, where plastic masses are to be given antistatic properties. Pigments of the stated composition also serve as additives to plastics which are provided with laser markings because mica coated with antimony-doped tin dioxide absorbs conventional laser radiation and the stored heat penetrates into the pigment matrix surrounding the plastic matrix and blackens it. The use of antimony-doped tin dioxide-coated mica as LDS additive in the corresponding LDS-suitable plastic materials can therefore also lead to the formation of conductive paths there, if a critical use concentration is exceeded. However, conductive plastics are less suitable for use in the LDS process because they can significantly affect the electrical conductivity of the circuit structures deposited on the plastic base parts, and also the resulting MIDs for special high-frequency applications (RF applications) such as portable telephones with integrated antennas or electronic components for use in

Exclude WLAN systems in which the plastic base part is subject to strict requirements regarding its dielectric properties. In order to obtain plastics with dielectric values which are sufficiently good in the polymer composition and which are suitable for the LDS process and with which HF-capable electronic components are available, it has been proposed, for example in US Pat. No. 8,309,640 B2, to use thermoplastic synthetic materials in addition to a suitable LDS solvent. Add additive ceramic fillers, which, measured at 900 MHz, a dielectric constant of at least 25 have. However, since the LDS additives used here are the conventional copper compounds already mentioned above, such LDS-suitable plastics have good dielectric values but are dark to black.

There was therefore still a need for plastics which are suitable for the LDS process and have both a light inherent color also have sufficiently high dielectric values in the polymer mass so that they can be used for high-frequency applications. In particular, there has been a demand for suitable LDS additives for plastics. Of course, all other 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 thus to provide an LDS additive for LDS plastics which, by virtue of its light inherent coloration, enables the production of light LDS plastics which can easily be colored with small amounts of colorant admixtures in brightly colored colors the provided with it

Plastic dielectric or even so low electrically conductive properties imparts that this plastic is suitable for high frequency applications, which prevents the decomposition of the surrounding plastic matrix as far as possible and which also good metallization of the available in LDS circuit structures when using the widest possible bandwidth Laser parameters allows.

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 composite pigments which contain at least 80% by weight, based on the total weight of the composite pigments, of titanium dioxide (TiO ₂ ) and with Antimony doped tin dioxide ((Sb, Sn) 0 ₂ ) exist 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 containing at least one organic polymer plastic and an LDS additive, wherein the LDS additive is a composite pigment, which is at least 80 wt .-%, based on the total weight of Composite pigment, of titanium dioxide

10 (TiO ₂ ) and with antimony-doped tin dioxide ((Sb, Sn) O ₂ ).

In addition, the object of the invention is achieved by an article having a circuit structure produced in an LDS method, consisting of a polymer body of the article or a polymer

^ containing coating base body of the article and located on the surface of the body metallic interconnects, wherein the polymeric body or the polymer-containing coating of the body contains an LDS additive which consists of Kompositpigmenten, which is at least 80 wt .-%, based on the overall

2% of the composite pigments, titanium dioxide (TiO ₂ ) and antimony

doped tin dioxide ((Sb, Sn) O2) exist.

Composite pigments which largely consist of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide ((Sb, Sn) O ₂ ) are known per se, in particular in the form of pigments consisting of a titanium dioxide core and a coating present on the core consist of antimony-doped tin dioxide. Optionally, these pigments may also have a protective layer and / or an intermediate layer between core and (Sb, Sn) O ₂ coating. Pigments of this type in which the TiO ₂ core can have various geometric shapes have long been used as antistatic agents in coatings and plastics. They themselves exhibit electrical conductivity and give the coating or plastics that contain them in sufficient concentration, also an electrical conductivity. To increase this electrical conductivity, in particular such pigments have been developed in recent years, in which the Ti0 ₂ core is needle-shaped.

Surprisingly, it has now turned out, however, that composite pigments which consist of at least 80% by weight, based on the total weight of the composite pigments, of TiO ₂ and antimony-doped tin dioxide are very well suited as LDS additives in a polymeric composition.

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

The composite pigments used according to the invention have at least one core and a coating arranged on the core. In this case, the coating can be composed of one or more individual layers.

In the simplest case, the coating consists of a single, functional layer. Furthermore, the coating between the core and the functional layer may have one or more intermediate layers and / or one or more on the surface of the functional layer

Have protective layers.

If a single composite pigment particle only consists of a single core and a coating located on the core, the composite pigments used according to the invention are composed exclusively of primary particles and thus monodisperse. However, the embodiment in which the composite pigments used are agglomerates of two or more is more frequent and thus preferred Primary particles, each primary particle having a core and a coating disposed on the core.

According to the invention, both composite pigments whose primary particles have a layer structure of the order core / functional layer, a layer structure core / intermediate layer (s) / functional layer, a

Layer structure core / functional layer / protective layer (s) or a layer structure core / intermediate layer (s) / functional layer / protective layer (s) have to be used. According to the invention, either the core or the functional layer consists of TiO ₂ or antimony-doped tin dioxide.

Of course, since the core and the functional layer do not consist of the same material in one and the same composite pigment or primary particles, the composite pigments used according to the invention may have the following compositions:

TiO ₂ core / (Sb, Sn) O ₂ layer,

TiO ₂ core / intermediate layer (s) / (Sb, Sn) O ₂ layer,

TiO ₂ core / (Sb, Sn) O ₂ layer / protective layer (s),

TiO ₂ core / intermediate layer (s) / (Sb, Sn) O ₂ layer / protective layer (s),

(Sb, Sn) O ₂ -Kem TiO ₂ layer,

(Sb, Sn) 0 ₂ core / intermediate layer (s) / Ti0 ₂ layer,

(Sb, Sn) 0 ₂ core / Ti0 ₂ layer / protective layer (s),

(Sb, Sn) 0 ₂ core / intermediate layer (s) / Ti0 ₂ layer / protective layer (s),

The weight fraction of the sum of core and functional layer, ie the sum of TiO ₂ and antimony-doped tin dioxide, is in each case at least 80% by weight, preferably at least 90% by weight, and in particular 95-100% by weight. %, based on the total weight of the composite pigment. That is, in a particularly preferred embodiment of the present invention, the composite pigment used consist only of TiO ₂ and (Sb, Sn) 0 ₂ or optionally only the smallest amounts of other ingredients are included.

The antimony-doped tin dioxide, regardless of whether it is used as a core or as a functional layer in the coating of the primary particles, is a material in which the percentage by weight of antimony, relative to tin, between 2 and 35 wt .-%, preferably from 8 to 30 wt .-% and in particular from 10 to 20% by weight, based on the total weight of antimony and tin, is.

If intermediate layers and / or protective layers are present, these consist predominantly of inorganic materials, if they are intermediate layers. Well suited as intermediate layers are metal oxides, in particular SiO ₂ , SnO ₂ , Al ₂ O ₃ , ZnO, CaO, ZrO ₂ , Sb ₂ O ₃ , or mixtures thereof.

On the other hand, protective layers which can be present on the surface of the composite pigments used can be both inorganic and organic in nature. They are usually applied when the use of the composite pigments in the application medium, in this case the organic polymer plastic, is facilitated or made possible by a corresponding surface coating. But you can also be applied to make any desired color adjustments. In the case of inorganic protective layers, these are preferably ZrO _2, Ce ₂ O _3, Cr ₂ O3, CaO, _SiO2, Al2O3, ZnO, _TiO2, _SnO2, antimony-doped SnO _2, Sb ₂ O 3, or the corresponding oxide hydrates, as well as mixtures of two or more of these. Organic protective layers are usually made of suitable

Organosilanes, organotitanates or Organozirkonaten. suitable Substances are known to the person skilled in the art as agents for surface coating and subsequent coating of effect pigments.

The total weight fraction of intermediate and / or protective layer (s) is at most 20% by weight, preferably at most 10% by weight, and particularly preferably 0-5% by weight, based on the total weight of the composite pigment.

In a preferred embodiment of the invention, the composite pigment used as LDS additive consists only of one or more primary particles which are each composed of a core and a functional coating located on the core, ie a TiO ₂ core and a (Sb, Sn ) O ₂ coating or of a (Sb, Sn) O ₂ core and a TiO ₂ coating; but most preferred is the embodiment in which the composite pigment consists of primary particles (n) each consisting of a TiO 2 core and a (Sb, Sn) O ₂ coating. Optionally, only up to 5% by weight, based on the total weight of the composite pigment, of foreign constituents which may be contained in interlayers and / or protective layers.

The core in the composite pigments used according to the invention may in itself have any conceivable form. However, it has proved to be advantageous, in particular with regard to the electrically conductive properties which lend the composite pigments used according to the invention as an LDS additive to the polymeric plastics provided therewith, if the core has an isotropic form in the composite pigments. These are shapes which are more or less ideal in all directions of the nucleus, viewed from an imaginary center, and are therefore the same, ie have no preferential direction. These include spherical and cube-shaped cores and cores that have irregular, compact granular forms, but also forms of regular or semi-regular polyhedra with n faces (Platonic and Archimedean bodies), where n ranges from 4 to 92.

It goes without saying that the terms spherical, cube-shaped or regular also apply here to core shapes that are not ideally spherical in the geometrical sense, ideally cube-shaped or ideally regular. Since the cores of the composite pigments are produced in technical processes, technological deviations from the ideal geometric shape, such as rounded edges or surfaces with slightly different size and shape in polyhedral bodies, are also included here.

The cores in the composite pigments used according to the invention have a particle size in the range from 0.001 to 10 μm, preferably from 0.001 to 5 μm and in particular from 0.01 to 3 μm.

They consist of T1O2 or of (Sb, Sn) 02, which are specified in the

Magnitude in the market are available. For example, TiO 2 particles are available on the market under the brand names KRONOS (KRONOS Worldwide, Inc.), HOMBITEC (Sachtleben) or Tipaque (Ishihara Corp.). Antimony-doped tin dioxide particles may be obtained, for example, under the name Zelec (Milliken Chemical) or SN (Ishihara Corp.).

On the surface of the cores of the size and material composition given above, the primary particles of the composite pigments used according to the invention have a coating which has a layer thickness in the range from 1 to 500 nm, preferably in the range from 1 to 200 nm.

The coating contains, as already explained above, at least one functional layer which, depending on the material composition of the core, consists of TiO ₂ or (Sb, Sn) O ₂ . Intermediate layer (s) or protective layers, if present, are also included in the coating. The above said order of magnitude for the layer thickness of the coating applies both to the coating, which consists only of a functional layer as described above, as well as to the coating, which in addition to the functional layer still one or more intermediate layers and / or protective layers. Particularly preferred is a

Layer thickness range of 1 to 100 nm for a coating consisting of only one (Sb, Sn) 02 functional layer.

The proportion of the coating is 20 to 70 wt .-%, based on the total weight of a primary particle and also 20 to 70 wt .-%, based on the total weight of the Kompositpigmentes. This information relates both to a coating which consists only of a functional layer as described above and to a coating which, in addition to the functional layer, also contains one or more intermediate layers and / or protective layers.

The core consists of ΤΊΟ _2, the proportion of the coating which at least one functional layer of (Sb, Sn) 0 ₂ or consists of, more preferably in the range of 35 to 55 wt .-%, in particular in the range of 40 to 50 wt .-%, based on the total weight of a primary particle or on the total weight of the Kompositpigmentes.

If the core consists of (Sb, Sn) O 2, the proportion of the coating which contains or consists of at least one functional layer of ΤΪΟ 2 is particularly preferably in the range from 45 to 65% by weight, in particular in the range from 50 to 60 Wt .-%, based on the total weight of a primary particle or on the total weight of the composite pigment. The particle size of the composite pigments used according to the invention is in the range from 0.1 to 20 μm, preferably from 0.1 to 10 μm and in particular from 0.1 to 5 μm. Particular preference is given to composite Pigments with particle sizes in the range of 0.1 to 1 pm with a D ₉₀ - value in the range of 0.70 to 0.90 pm used.

All of the above 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, wherein advantageously both the nominal

Particle size of the individual particles and their percentage particle size distribution can be determined. All particle size determinations carried out in the present invention are determined according to the laser diffraction method with a Malvern 2000 instrument from Malvem Instruments Ltd., UK, according to standard conditions of ISO / DIS 3320. The layer thickness of the respective coating is determined numerically using SEM and / or TEM images.

The composite pigments used according to the invention are prepared by methods known per se. In this case, the starting particles used as cores are provided with a coating which contains at least one functional layer in one of the abovementioned compositions, but preferably consists only of this functional layer. Since it is inorganic in each case

Is the coating materials of the cores with the functional layer, preferably in aqueous suspension

Accidents of the respective metal oxides or metal oxide hydrates with

subsequent conversion into the metal oxides. In this case, precursor materials for the metal oxides to be obtained, generally metal salts, are added in dissolved form to the aqueous suspension of the respective core materials and precipitated at appropriately adjusted pH on the cores, generally in the form of the metal oxide hydrates.

Subsequently, the metal oxide hydrates are treated by treatment with elevated Temperature converted into the corresponding oxides. The coating of the cores with the optionally applied intermediate and / or protective layers can be carried out in the same way, as long as they are inorganic layers. Organic post coats are also made by the methods commonly used in the art, in particular by directly contacting the surfaces of the composite particles with the corresponding organic materials in a suitable medium. Using the example of TiO ₂ nuclei, which are provided with a functional coating of antimony-doped tin dioxide, the composite pigments used according to the invention are prepared as follows:

Almost spherical TiO ₂ particles of the desired size are mixed with demineralized water to form a suspension which is heated with stirring to a temperature in the range of 70 to 90 ° C. With an acid, for example hydrochloric acid, the pH of the suspension is adjusted to a value in the range of 1.5 to 2.5. A hydrochloric acid solution of tin-antimony chloride in the desired composition is added to the suspension while keeping the pH constant with a base, for example sodium hydroxide solution. After completion of the addition, the pH is raised to a value of> 2.5 to 7.0 and stirred. The product is filtered off, washed, dried and annealed in the temperature range of 500 ° C to 900 ° C for 0.5 to 2 hours.

Subsequently, the product can optionally be sieved. A composite pigment of TiO 2 cores with a coating of (Sb, Sn) O _{2 is} obtained.

The coating of (Sb, Sn) O ₂ core particles with TiO ₂ can be carried out in an analogous process in aqueous suspension at a pH in the range from 1.5 to 2.5 with suitable titanium salts, for example with TiCl ₄ . The composite pigments described are 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 .-%, respectively based on the total weight of the polymeric composition. They may also be used in blends with other prior art known LDS additives 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 generally not more than the above-mentioned 30% by weight, based on the total weight of the LDS-compatible polymeric composition.

The polymeric composition is preferably a thermoplastic polymeric composition which is predominantly composed (generally> 50% by weight) of thermoplastics.

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), liquid crystal polymers (LCP) or their copolymers or blends, such as acrylonitrile-butadiene-styrene / polycarbonate blend (PC / ABS) or PBT / PET. They are offered by all well-known polymer manufacturers in LDS-suitable qualities.

In addition, the polymeric compositions which contain the composite pigment used according to the invention as an LDS additive may optionally additionally contain fillers and / or colorants as well as stabilizers, auxiliaries and / or flame retardants. Suitable fillers are, for example, various silicates, Si0 ₂ , talc, kaolin, mica, wollastonite, glass fibers, glass beads, carbon fibers or the like. Suitable colorants are both organic dyes and inorganic or organic color pigments. Since the LDS plastic compositions provided with the LDS additives according to the invention are very light and thus readily dyeable, virtually all soluble dyes or insoluble color pigments suitable for plastics can be used. As examples, only the particularly frequently used white pigments Ti0 ₂ , ZnO, BaS0 ₄ and CaCO 3 are mentioned here. The amount and type of added fillers and / or colorants is limited only by the particular concrete material properties of the individual LDS-suitable compositions, in particular of the plastics used.

It has surprisingly been found that the composite pigments used according to the invention, which consist of at least 80% by weight, based on the total mass of the composite pigments, of TiO ₂ and (Sb, Sn) O ₂ , are very well suited as LDS additives and lead to the formation of electrical conduction paths in the polymer body or the polymer-containing coating on the base body of the article to be produced even in the thus added polymeric compositions for the LDS process at a conventional use concentration of 0.1 to 30 wt .-% although the composite pigments as such have a certain electrical conductivity. Furthermore, they have a bright, whitish-gray to bluish-gray intrinsic color, which does not give the stained plastics any disturbing dark intrinsic color. The L ^* values (brightness values) measured in the ClELab ^* system are only the

Additives according to the invention in a concentration of 2 wt .-%, based on the plastic, containing plastics are greater than 65, measured with a Minolta CR-300. Therefore, the LDS-suitable Plastics containing the LDS additive according to the invention are colored with all the colored colorants as needed, without a large amount of colorants, the effectiveness of the LDS additive reduces or nullifies. At the same time, however, the LDS additives used according to the invention have a high laser activity and, in the case of laser action according to the LDS method, lead to the desired microrough surfaces within the laser structures ablated and carbonized conductive structures, so that a subsequent metallization in good quality is possible. In the best conditions an excellent metallization is possible as well as, especially surprisingly, a very good metallizability 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. If the particularly preferred embodiment of the present invention is used as the LDS additive, namely a composite pigment which has a TiO ₂ core and a coating on the surface of the core which consists of antimony-doped tin dioxide or at least predominantly contains it Use as LDS additive in plastic-containing polymer compositions also no degradation of surrounding the composite pigments

organic polymer molecules instead. However, as already mentioned above, the fact that LDS-suitable compositions containing the LDS additive used according to the invention and no other electrically conductive constituents otherwise, is particularly surprising, the conditions for the applicability in the high-frequency range (HF range, 1 -20 GHz). To achieve this, the plastic compositions must have a relatively low relative permittivity ε ' _Γ (ratio of the permittivity, ie the permeability for electric fields, of the medium in comparison to Vacuum) and a low dielectric loss factor tan δ (measure of the energy loss that causes the medium in the electric field) have. Both characteristics are both frequency-dependent and temperature-dependent and should therefore be measured under the conditions of use under which the electronic components to be produced in the LDS process usually work. For high-frequency applications, therefore, measurement conditions at room temperature and at frequencies of at least 1 GHz come into question. When measured at frequencies equal to or greater than 1 GHz, the dielectric loss factor of the LDS-suitable compositions provided with the LDS additives should not exceed 0.01 if these polymeric compositions are to be suitable for HF applications. Polymeric compositions, in particular thermoplastic polymer compositions, which contain the LDS additives used according to the invention in the abovementioned amounts and have no further electrically conductive constituents, meet the stated conditions.

The present invention also provides a polymeric composition which contains at least one organic polymer plastic and an LDS additive, wherein the LDS additive is a composite pigment which comprises at least 80% by weight, based on the total weight of the composite pigment, of titanium dioxide (Ti0 ₂ ) and with antimony-doped tin dioxide ((Sb, Sn) 0 ₂ ). In this case, the polymeric composition contains the LDS additive in a proportion of 0.1 to 30 wt .-%, based on the total weight of the polymeric composition.

Details regarding the material composition of the LDS additive, the polymer materials used and any auxiliary substances and additives such as fillers, colorants and the like have already been described above. This is referred to here. The novel polymeric composition is intended for use in an LDS process (laser direct structuring method) for producing metallized switching structures on three-dimensional plastic basic bodies or plastic-containing coatings bearing three-dimensional basic bodies. It has, without the use of colorants, such a light intrinsic coloration that they can be colored with conventional dyes and / or color pigments as needed, is very well suited for use in high-frequency applications and causes by the addition of the LDS additive according to the invention good metallization of the laser-generated line structures, the laser parameters can be selected in a wide range.

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 The basic body or the polymer-containing coating of the base body contains an LDS additive which consists of Kompositpi- elements which comprise at least 80 wt .-%, based on the total weight of the composite, of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide (Sb, Sn) O.sub.2. Such articles, in particular articles made of organic plastics, find use, for example, in the telecommunications, medical or automotive industries, where they are used, for example, as electronic components of mobile telephones, hearing aids, dental Instruments, car electronics and the like can be used ,

FIG. 1 shows the SEM image of an LDS additive according to the invention according to Example 1 The present invention will be explained below by means of examples, but not limited to these.

Example: Production of a Composite Component:

100 g of nearly spherical TiO ₂ particles (Kronos 2900, product of KRONOS Inc.,) having an average particle size in the range of 100-300 nm (measured by the laser diffraction method with a measuring instrument from Malvern Ltd., UK, Malvern 2000 , under standard conditions) are heated in 2 l of demineralized water with stirring to 75 ° C. The pH of the suspension is adjusted to 2.0 with 10% hydrochloric acid. Subsequently, a hydrochloric tin-antimony chloride solution consisting of 264.5 g of a 50% SnCl ₄ solution, 60.4 g of a 35% SbCl ₃ solution and 440 g of a 10% hydrochloric acid is added slowly, wherein the pH of the suspension is kept constant by simultaneous slow addition of a 32% sodium hydroxide solution. After complete addition is still 5 min. stirred. The pH is then adjusted to a value of 3.0 by addition of 32% sodium hydroxide solution and a further 30 min. stirred.

The product is filtered off, washed, dried, at a temperature of 500-900 ° C for 30 min. annealed and screened through a 50 μιτι sieve.

It is a composite pigment of TiO ₂ and (Sb, Sn) O ₂ having a particle size in the range of 0.1 to 1, 7 pm with a D ₅₀ value of 0.18 pm and a D ₉ o value of 0, Received 74 pm. The composite pigment has a bright greenish-gray body color. The ratio Sn.Sb in the coating is 85:15.

Application Example 1 Measurement of brightness values corresponding to L * in the ClELab system, measured using a Minolta CR-300 measuring instrument from Minolta Co .. Ltd .:

By means of a co-rotating twin-screw extruder 5 wt .-% LDS additive in PC / ABS (Xantar C CM 406, Mitsubishi Engineering Plastics) are incorporated. The extrudate is strand granulated and then dried at 100 ° C. Thereafter, test plates of dimensions 60 × 90 × 1.5 mm are injection-molded on an injection molding machine.

The brightness values L ^* in the ClELab system are indicated by a

Measuring instrument of the brand Minolta CR-300 under standard conditions. The average values from 5 different measurements are given.

The following values are determined:

Table 1 :

LDS additive Particle size Particle shape L ^* value Ex.

(Sb, Sn) 0 ₂ 3-14pm Granules 32 Comp

(Sb, Sn) 0 ₂ 0.05-9 pm Granules 34 Comp

Mica / (Sb, Sn) 0 ₂ Minatec 51 platelet 58 Comp.3

8-52 pm

Mica / (Sb, Sn) 0 ₂ Iriotec 8825 platelets 64 Comp.4

2-13 pm

Pigment acc. 0.1-1.7 pm agglomerate with 69 exper

Example 1 balls. Primary part.

Pigment acc. 0.1-1, 7 pm agglomerate with 70 erf.2

Ex. 1 (2.5 wt.%) Spheres. Primary part.

(Minatec® 51 and Iriotec® 8825 are products of Merck KGaA, the particle sizes in Table 1 with respect to the comparative examples are each rounded, in Example 2 according to the invention only 2.5% by weight of the additive are used).

From Table 1 it can be seen that the composite pigment used according to the invention in a polymeric plastic matrix significantly higher Brightness values as granules consisting of antimony-doped tin dioxide. The brightness values compared to antimony doped tin dioxide coated mica are half and

identical concentration of the LDS additive in the inventive example slightly better than in the comparative examples.

Application Example 2:

Verification of metallization properties:

5% by weight of LDS additive (Cu spinel, material according to Comparative Example 4 and material according to Inventive Example 1) are incorporated into PC / ABS by means of an extruder and test plates are produced from the resulting compound on an injection molding machine. 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 using a 1064nm fiber laser so that a lower

Material removal occurs with simultaneous carbonization of the machined surface. Subsequently, the metallization is carried out with copper in a commercially available reductive copper bath (MID Copper 100 B1, MacDermid). The metallization properties are based on the structure of the

Copper layer on the substrate assessed. The plating index (according to MacDermid) is given, which is calculated from the quotient of the built-up copper layer of the test material and the built-up

Copper layer of the reference material results. As reference material are test plates made of PBT with a share of 5 wt .-% copper spinel.

Laser adjustment plating index

Cu Spinel Comp.ex.4 Example 1

3W / 60 kHz 0.41 0.00 0.00

4W / 60kHz 0.56 0.00 0.00

5W / 60 kHz 0.65 0.00 0.00

6W / 60 kHz 0.71 0.00 0.00 7W / 60kHz 0.76 0.00 0.58

8W / 60 kHz 0.69 0.15 0.74

W / 80 kHz 0.65 0.00 0.00

6W / 80 kHz 0.83 0.00 0.00

8W / 80kHz 0.76 0.00 0.74

10W / 80kHz 0.73 0.00 0.80

12W / 80kHz 0.70 0.16 0.72

14W / 80 kHz 0.63 0.54 0.65

6W / 100 kHz 0.88 0.00 0.00

8W / 100 kHz 0.79 0.00 0.71

10W / 100kHz 0.70 0.00 0.81

12W / 100 kHz 0.68 0.00 0.77

14W / 100 kHz 0.72 0.34 0.68

16W / 100 kHz 0.67 0.75 0.62

The experiments show that the LDS additive used in accordance with the invention exhibits significantly better values in terms of metallizability both in the width of the laser parameters and in terms of the nominal values of the plating index than the antimony-doped tin dioxide-coated mica flakes according to Comparative Example 4, in the peak values with the Cu Spinel is comparable and shows very good metallization especially at higher laser power.

Application Example 3

Material measurements for HF suitability:

Test plates such as those from Application Example 2 are measured with the difference that no laser processing and metallization takes place before the measurement.

The permittivity of the materials in different frequency ranges and with different methods is measured. The measurements are carried out at room temperature. For measurements in the frequency range 1 MHz to 1 GHz, an Agilent E4991A impedance analyzer is connected used with a test holder Agilent 16453. The evaluation is carried out with the "Material Measurement Firmware" of the E4991A.

For measurement at 2.69 GHz and at 3.9 GHz, a high-quality resonator (cavity resonator in the TE11 mode) is used and the resonant characteristics of the empty resonator and the resonator loaded with the dielectric samples are measured using a network analyzer 'Rhode & Schwarz ZVA measured. The evaluation takes place after

Calculation instructions according to S. Zinal and G. Boeck, "Complex

Permittivity Measurements using TE11p Modes in Circular Cylindrical Cavities, "IEEE Trans. Microwave Theory Tech., Yol 53, pp.1870-1874, June 2005.

For the frequency 1 GHz, the following measured values result:

z tan δ

Example 1: 3.04 0.00373

Cu spin line: 2.91 0.00411

Comparative Example 4: 2.98 0.00488

For the frequency 2.69 GHz, the following measured values result

E ' _r tan δ

Ex. 1: 2.861 0.0048

Cu spinel 2,759 0,00496

Comparative Example 4: 4.029 0.0216

For the frequency 3.9 GHz, the following measured values result:

e'r tan δ

Ex. 1: 2,892 0.005

Cu spinel 2,736 0.0047

Comparative Example 4: 4.072 0.0253

As the measurements show, in terms of suitability in the high-frequency range, the copper spinel commonly used as an LDS additive and the LDS additive according to the invention used according to Example 1 comparable, while coated with antimony doped tin dioxide mica flakes (Comparative Example 4) at frequencies> 1GHz both too high a relative permittivity and a much too high dielectric loss factor.

Claims

Patent claims

Use of composite pigments, which consist of at least 80% by weight, based on the total weight of the composite pigments, of titanium dioxide (TiO ₂ ) and tin dioxide doped with antimony ((Sb,Sn)0 ₂ ), as an LDS additive (laser direct structuring -Additive) in a polymeric composition.

Use according to claim 1, characterized in that the composite pigments have at least one core and a coating arranged on the core.

Use according to claim 1 or 2, characterized in that the core has an isotropic shape.

Use according to one or more of claims 1 to 3, characterized in that the core is spherical, cube-shaped, in the form of a regular or semi-regular polyhedron with n faces, where n is in the range from 4 to 92, or in the form of granules.

Use according to one or more of claims 1 to 4, characterized in that the core consists of Ti0 ₂ and has a coating which contains (Sb,Sn)0 ₂ .

Use according to one or more of claims 1 to 4, characterized in that the core consists of (Sb,Sn)0 ₂ and has a coating which contains Ti0 ₂ .

7. Use according to one or more of claims 1 to 6,

characterized in that the proportion of the coating is 20 to 70 % by weight, based on the total weight of the composite pigment.

8. Use according to one or more of claims 1 to 7,

characterized in that the core has a particle size in the range from 0.001 to 10 pm.

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

characterized in that the coating has a layer thickness in the range from 1 to 500 nm.

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

characterized in that the composite pigments each consist of one or two or more primary particles, each primary particle having a core and a coating arranged on the core.

1 . Use according to one or more of claims 1 to 10, characterized in that the composite pigments each have a particle size in the range from 0.1 to 20 pm.

12. Use according to one or more of claims 1 to 11, characterized in that the composite pigments are present in the polymeric composition in a proportion in the range of 0.1 to 30% by weight, based on the total weight of the polymeric composition.

13. Use according to one or more of claims 1 to 12, characterized in that the polymeric composition contains, in addition to the LDS additive, at least one organic polymeric plastic and optionally fillers and / or colorants.

14. Polymeric composition containing at least one organic polymeric plastic and an LDS additive, wherein the LDS The additive is a composite pigment which consists of at least 80% by weight, based on the total weight of the composite pigment, of titanium dioxide (T1O2) and tin dioxide doped with antimony ((Sb,Sn)0 ₂ ).

15. Polymeric composition according to claim 14, characterized

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.

16. Article with a circuit structure produced in an LDS process, consisting of a plastic base body or a base body having a plastic-containing coating and metallic conductor tracks located on the surface of the base body, the plastic base body or the plastic-containing coating of the base body being an LDS Contains additive, which consists of composite pigments which consist of at least 80% by weight, based on the total weight of the composite pigments, of titanium dioxide (T1O2) and tin dioxide doped with antimony ((Sb,Sn)0 ₂ ).