JP2016520139A - Additives for LDS plastics - Google Patents

Abstract

The present invention relates to an LDS active additive for LDS plastics, to a polymer composition comprising this type of additive, to an article having a metallized conductor track, wherein the polymer substrate of the article or the polymer coating on the substrate is of the aforementioned type of LDS addition The present invention relates to an article containing an agent.

Description

  The present invention relates to LDS active additives for LDS plastics, and in particular consists primarily of titanium dioxide and antimony-doped tin dioxide as LDS additives in polymer compositions used in LDS processes. Use of composite pigments, polymer compositions containing additives of this type, and articles having metallized conductor tracks on the polymer body or substrate of the article Of the polymer coating comprises an LDS additive of the type described above.

  Three-dimensional plastic parts that carry circuits, so-called MID (moulded interconnect devices), have established themselves in the market for many years and are related to many applications such as telecommunications, automotive manufacturing or medical technology. And make important contributions to promote cutting-edge technology. Similarly, they contribute significantly to the miniaturization and complexity of individual electronic components in such applications.

  There are various methods for the production of three-dimensional MIDs, which are obtained by basic components containing plastic or having a plastic-containing coating layer (for example by two-component injection molding or hot embossing). ) Is given the necessary circuit structure. This typically requires special product-specific molds that are expensive to purchase and inflexible in use.

  In contrast, the LDS process (laser direct structuring process) developed by LPKF is a plastic base part that directly and individually adapts the circuit structure with a laser beam. Or it offers the important advantage that it can be engraved into a plastic-containing coating on a substrate part and then metallized.

  Simpler processes, such as one-component injection molding processes, are suitable for the production of plastic substrate parts, and the engraving of the circuit structure can likewise be controlled in three dimensions.

  In order to be able to obtain circuitry that can be metallized by means of a laser beam, so-called LDS additives must be added to the plastic substrate part or the plastic-containing coating. This additive must be prepared for subsequent metallization at the same time it reacts to laser irradiation.

  LDS additives generally contain a metal compound that is activated during processing with a laser beam in the laser processing region so that metal nuclei are liberated, which is the activity in the plastic. This is advantageous for the subsequent deposition of conductive metal to form an electrical circuit at the optimized point. At the same time, these metal compounds react laser-actively (usually laser-absorbing) to ensure that the plastic is ablated and carbonized in the laser processing region, so that the circuit configuration is Engraved on plastic substrate parts. At points in the plastic that have not been activated by the laser, the metal compound remains unchanged. The LDS additive can be added entirely to the plastic material prior to molding to give the plastic substrate part, or alternatively as a component in a separate plastic-containing layer, coating, paint layer, etc. , LDS additive may be present only on the surface (where the circuit structure is engraved by the laser beam).

  In addition to future circuit structures containing metal nuclei, processing with a laser beam creates a microrough surface within the circuit structure, which is due to conductive metals, usually copper. It provides prerequisites and can fix itself to the plastic with strong adhesion during subsequent metallization.

  Metallization is usually subsequently performed in a currentless copper bath, but subsequently a nickel layer and a gold layer may be further deposited in a currentless bath as well. However, other metals such as tin, silver and palladium can be applied as well, optionally in combination with gold, for example. Such pre-structured plastic parts are then attached to individual electronic components.

  The purpose of the LDS process is to produce a three-dimensional conductive circuit structure on a three-dimensional plastic substrate or a substrate having a plastic-containing coating. Needless to say, for this purpose, only the manufactured metallized circuit structure can have electrical conductivity, and the plastic substrate or the coating itself may not have electrical conductivity. Accordingly, the LDS additives that have been proposed so far are generally not themselves electrically conductive and do not impart electrical conductivity to the substrate.

  Originally, non-conductive organic heavy metal complexes, particularly those containing palladium (EP0917597B1), were intended as LDS additives.

  In EP 1274288B1, a non-conductive inorganic metal compound, which is insoluble in an application medium and is an inorganic metal compound of a metal and a non-metal of groups d and f of the periodic table, is a plastic as an LDS additive. It is added to. The use of copper compounds, in particular copper spinel, is preferred.

  However, organopalladium complexes or similarly copper spinels themselves have a dark intrinsic color and, in addition, have the disadvantage of imparting a dark color to the plastics containing them. Furthermore, in particular, the copper compounds have the effect of partially degrading the plastic molecules surrounding them. However, particularly for MIDs used in telecommunications, there is an increasing demand for plastics with a light intrinsic coloration. This is so that the plastic can be colored to any desired shade and that it is not necessary to add colored pigments in a large weight proportion that adversely affects or weakens the efficacy of the LDS additive. Furthermore, deterioration of the plastic substrate is undesirable.

  Thus, EP 2476723 A1 has proposed tectoalmosilicate (zeolite) as an LDS additive for plastics in order to make plastics with a light intrinsic color that is easy to use in the LDS process.

WO 2012/126931 discloses plastics suitable for LDS and corresponding LDS processes, wherein an LDS additive comprising antimony-doped tin dioxide and having an L ^* value (luminance) of at least 45 in the CIELab color space. It has been added. Mica coated with antimony-doped tin dioxide is preferably used in an amount of 2 to 25% by weight, based on the total plastic material. Furthermore, white pigments can additionally be added for lighter coloring of the plastic material.

WO 2012/056416 also discloses a composition comprising 0.5 to 25% by weight of a metal oxide coated filler, in which the latter (metal oxide coated filler) is mica coated with antimony-doped tin dioxide. Preferably there is. The LDS plastic material has an L ^* value of 40 to 85. Color pigments may be added to the plastic material as well.

  Mica flakes coated with antimony-doped tin dioxide are commonly used as conductive pigments in a very wide variety of applications, such as applications where antistatic properties are imparted to plastic materials. Mica coated with antimony-doped tin dioxide absorbs normal laser radiation, and the stored heat penetrates into the plastic matrix surrounding the pigment and blackens it, so the pigment in the composition as well Works as an additive for plastic, laser engraved. Therefore, the use of mica coated with antimony-doped tin dioxide as an LDS additive in the corresponding plastic material, suitable for LDS, also forms a conductive path there if the critical working concentration is exceeded Results in being able to. However, conductive plastics are not well suited for use in LDS processes. Because they may significantly impair the conductivity of circuit structures applied to plastic substrate parts, and the resulting MID is a WLAN system where stringent requirements are applied to plastic substrate parts with respect to their dielectric properties. This is because it is not suitable for certain high frequency applications (HF applications) such as mobile phones with integrated antennas and electronic components for use.

  Suitable for example in US 8309640 B2 to obtain plastics with sufficiently good dielectric values in polymer materials, which can be suitable for LDS processes and thereby obtain electronic components suitable for HF In addition to other LDS additives, it has been proposed to add to the thermoplastic material a ceramic filler having a dielectric constant of at least 25, measured at 900 MHz. However, since the LDS additive used here is the usual copper compound already mentioned above, a plastic suitable for this type of LDS is dark to black, although it has a good dielectric value.

  Accordingly, there was still a need for plastics that are suitable for LDS processes, have a light intrinsic color and have a high dielectric value in polymer materials so that they can be used for high frequency applications. In particular, there was a need for suitable LDS additives for plastics. Of course, here all the other requirements for the LDS additive are: the ability to be activated by laser irradiation, the release of metal nuclei by laser bombardment, and the fine rough surface by the laser beam as the basis for subsequent metallization. Formation, must be satisfied.

Accordingly, it is an object of the present invention to provide an LDS additive for LDS plastics, which LDS additive is easily colored chromatic with a small amount of colorant mixture due to its pale inherent coloration. Enables the production of light LDS plastics that can be given and only gives the plastics they are supplied with dielectric properties or slight electrical conductivity so that these plastics are suitable for high frequency applications and, if possible, of the surrounding plastic matrix Decomposition is prevented and, furthermore, the maximum possible bandwidth of the laser parameters is used to allow good metallization of the circuit structure that can be obtained during the LDS process.
A further object of the present invention is to provide a polymeric composition that is suitable for the LDS process and has the properties described above.

  It is a further object of the present invention to provide an article having a circuit configuration manufactured by an LDS process and having the characteristics described above.

The object of the present invention is to provide at least 80% by weight of titanium dioxide (TiO ₂ ) and antimony-doped tin oxide (as a LDS additive (laser direct structuring additive) in the polymer composition, based on the total weight of the composite pigment). This is achieved by the use of a composite pigment consisting of (Sb, Sn) O ₂ ).

The object of the invention is also a polymer composition comprising at least one organic polymer plastic and an LDS additive, wherein the LDS additive is at least 80% by weight of titanium dioxide (TiO 2) based on the total weight of the composite pigment. ₂ ) and an antimony-doped tin oxide ((Sb, Sn) O ₂ ).

Another object of the present invention is an article having a circuit structure produced by an LDS process comprising a polymer substrate of the article or a substrate of an article having a polymer-containing coating and a metal conductor track disposed on the surface of the substrate. The polymer substrate or the polymer-containing coating of the substrate from a composite pigment comprising at least 80% by weight of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide ((Sb, Sn) O ₂ ), based on the total weight of the composite pigment Achieved by an article comprising an LDS additive.

The composite pigment itself, which consists essentially of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide ((Sb, Sn) O ₂ ), in particular, has a titanium dioxide core and the antimony-doped tin dioxide present on this core. Known in the form of pigments consisting of coatings. These pigments may also optionally have an intermediate layer and / or a protective layer between its core and the (Sb, Sn) O ₂ coating. This type of pigment has long been used as an antistatic agent in coatings and plastics, although the core of TiO ₂ can have various geometric shapes. They themselves have electrical conductivity and impart electrical conductivity to coatings or plastics that contain them in sufficient concentration. In order to increase this conductivity, pigments having a needle-like core of TiO ₂ have been developed in recent years.

Surprisingly, however, composite pigments consisting of at least 80% by weight of TiO ₂ and antimony-doped tin dioxide based on the total weight of the composite pigment are now very suitable as LDS additives in polymer compositions. Was found.

  The present invention therefore relates to the use of said composite pigments as LDS additives in polymer compositions for use in LDS processes.

  The composite pigment used according to the invention has at least one core and a coating disposed on the core. The coating can be composed of one or more individual layers.

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

  If a single composite pigment particle is simply composed of a single core and a coating disposed on the core, the composite pigment according to the invention is composed exclusively of primary particles and is therefore monodisperse. However, embodiments where the composite pigment used is an aggregate of two or more primary particles, each primary particle having a core and a coating disposed on the core, are more frequent and therefore preferred.

According to the present invention, as both composite pigments, the primary particles have a layer configuration of a core / functional layer sequence, a core / intermediate layer (s) / functional layer configuration, a core / functional layer / protective layer ( It is possible to adopt one having a layer structure of a plurality of layers) or a layer structure of core / middle layer (s) / functional layer / protective layer (s). According to the invention, either the core or the functional layer is composed of tin dioxide doped with TiO ₂ or antimony.

  Since the core and functional layer in one and the same composite pigment or primary particle are of course not composed of the same material, the composite pigment used according to the invention can have the following composition:

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

Here, the weight proportion of the sum of the core and the 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 80% by weight, based on the total weight of the composite pigment 90% by weight, in particular 95-100% by weight. This means that in a particularly preferred embodiment of the invention, the composite pigment used consists only of TiO ₂ and (Sb, Sn) O ₂ , or optionally with very little other component.

  Whether antimony-doped tin dioxide is used as a functional layer in the primary particle coating or as a core, based on the total weight of antimony and tin, the weight percentage of antimony to tin is 2 Between 35 and 35% by weight, preferably 8 to 30% by weight, in particular 10 to 20% by weight.

If an intermediate layer and / or a protective layer are present, in the case of the intermediate layer, they consist mainly of inorganic materials. A very suitable intermediate layer is a metal oxide, in _{particular, SiO 2, SnO 2, Al} 2 O 3, ZnO, CaO, ZrO 2, Sb 2 O 3, or mixtures thereof.

In contrast, the protective layer that can be present on the surface of the composite pigment used can be either inorganic or organic. They are usually applied if the use of composite pigments in the application medium, here here in organic polymer plastics, is simplified or made possible at all by the corresponding surface coating. However, they can also be applied to make the desired color adjustment. In the case of inorganic protective layers, they are preferably ZrO ₂ , Ce ₂ O ₃ , Cr ₂ O ₃ , CaO, SiO ₂ , Al ₂ O ₃ , ZnO, TiO ₂ , SnO ₂ , antimony-doped SnO ₂ , Sb _2. O ₃ , or the corresponding oxide hydrate, and a mixture of two or more thereof.

  The organic protective layer usually consists of a suitable organosilane, organotitanate or organozirconate. Suitable materials are known to those skilled in the art as surface and post coating agents for effect pigments.

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

In a preferred embodiment of the invention, the composite pigment used as an LDS additive consists solely of one or more primary particles, in each case a core and a functional coating disposed on the core, ie TiO _2. It consists of a core and a (Sb, Sn) O ₂ coating or a (Sb, Sn) O ₂ core and a TiO ₂ coating. Most preferably, however, is an embodiment in which the composite pigment consists of primary particles, in each case consisting of a TiO ₂ core and a (Sb, Sn) O ₂ coating. Optionally, other components are present only up to 5% by weight, based on the total weight of the composite pigment, but it may be present in the intermediate layer and / or protective layer.

  The core in the composite pigment used according to the invention can itself have any conceivable shape. However, the isotropic shape of the core in the composite pigment means that the composite pigment used according to the present invention provides the LDS additive to the polymer plastic to which it is supplied (composite pigment). In particular, it has proved advantageous. These are shapes that are ideally about the same in all directions of the core as seen from the virtual center point, i.e., have no preferential direction. These include spherical cores, cuboid cores, and cores with irregular compact granular shapes, but regular or semi-polyhedra having an n-plane with n ranging from 4 to 92 ( The shape of regular or semi-regular polyhedra (platon and Archimedes) is included as well. The terms “spherical”, “cuboid” or “positive” in this context are not ideally spherical in shape, ideally not rectangular, or ideally “positive”. Needless to say, the present invention also applies to a core shape other than “polyhedron”. Since the core of the composite pigment is manufactured in an industrial process, technically induced deviations from the ideal geometry, such as rounded edges and slightly different sizes and shapes in the case of polyhedra. The face having is likewise included here.

The core in the composite pigment used according to the invention has a particle size in the range of 0.001 to 10 μm, preferably 0.001 to 5 μm, in particular 0.01 to 3 μm.
They are made of TiO ₂ or (Sb, Sn) O ₂ and are commercially available in approximately the indicated size.
Thus, for example, TiO ₂ particles are commercially available under the trade names KRONOS (KRONOS Worldwide Inc.), HOMBITEC (Sachtleben) or Tipaque (Ishihara Sangyo). Antimony-doped tin dioxide particles can be purchased, for example, under the name Zelec (Milliken Chemical) or SN (Ishihara Sangyo).

  On the surface of the core having the above size and material composition, the primary particles of the composite pigment used according to the invention have a coating with a layer thickness in the range of 1 to 500 nm, preferably in the range of 1 to 200 nm.

As already mentioned above, the coating comprises at least one functional layer of TiO ₂ or (Sb, Sn) O ₂ , depending on the material composition of the core. If intermediate layer (s) or protective layer (s) are present, they are counted in the coating as well. The above degree of size for the layer thickness of the coating applies here both to the coating consisting only of the functional layer and to a coating having one or more intermediate layers and / or protective layers in addition to the functional layer. . For coatings consisting only of (Sb, Sn) O ₂ functional layers, layer thicknesses in the range of 1-100 nm are particularly preferred.

The proportion of the coating layer is 20 to 70% by weight, based on the total weight of the primary particles, and likewise 20 to 70% by weight, based on the total weight of the composite pigment.
These data relate to both coatings that consist only of the functional layer and coatings that contain one or more intermediate and / or protective layers in addition to the functional layer.

If the core is composed of TiO ₂ , the proportion of the coating comprising or consisting of at least one (Sb, Sn) O ₂ functional layer is from 35 based on the total weight of the primary particles or the total weight of the composite pigment. A range of 55% by weight is particularly preferred, especially in the range of 40 to 50% by weight.

When the core consists of (Sb, Sn) O _2, the proportion of coating comprising or consisting of at least one TiO ₂ functional layer is 45 to 65% by weight, based on the total weight of the primary particles or the total weight of the composite pigment Is particularly preferred, especially in the range of 50 to 60% by weight.

The particle size of the composite pigment used according to the invention is in the range of 0.1 to 20 μm, preferably 0.1 to 10 μm, in particular 0.1 to 5 μm. Particular preference is given to using composite pigments having a particle size in the range from 0.1 to 1 μm and a D ₉₀ value in the range from 0.70 to 0.90 μm.

  All the particle sizes shown above can be measured using conventional methods for particle size measurement. Particularly preferred is a method for particle size measurement by laser diffraction, which can advantageously measure both the nominal particle size and the percentage of particle size distribution of individual particles. All particle size measurements performed in the present invention are performed under standard conditions of ISO / DIS 13320 under Malvern Instruments Ltd. It is measured by a laser diffraction method using a Malvern 2000 measuring instrument manufactured by (UK).

  The layer thickness of each coating is measured numerically from SEM and / or TEM images.

  The composite pigment used according to the invention is prepared by methods known per se. Among these, the starting particles as the core are provided with a coating, which coating comprises at least one functional layer in one of the compositions indicated above, but preferably consists only of this functional layer. Since the starting material is inorganic in each case, the coating of the core with the functional layer is preferably carried out by precipitation of the respective metal oxide or metal oxide hydrate in an aqueous suspension. The metal oxide precursor (usually a metal salt) to be obtained is added to an aqueous suspension of each core material in a dissolved form, and usually at an appropriately set pH, the metal oxide water A precipitate forms on the core in the form of a sum. Thereafter, the metal oxide hydrate is converted into a corresponding oxide by a heating process. The coating of the core with an optional intermediate layer and / or protective layer can be carried out in the same way as for the inorganic layer. Organic post-coatings are likewise carried out by methods customary in the prior art, in particular by directly contacting the surface of the composite particles with the corresponding organic material in a suitable medium.

The composite pigment used according to the invention is prepared as follows with reference to the example of a TiO ₂ core provided with a functional coating of antimony-doped tin dioxide.

Substantially spherical TiO ₂ particles of the desired size are mixed with deionized water to obtain a suspension and heated to a temperature in the range of 70 to 90 ° C. with stirring. The pH of the suspension is adjusted to a value in the range of 1.5 to 2.5 using an acid such as hydrochloric acid. While maintaining the pH constant with a base such as sodium hydroxide solution, a tin antimony chloride solution in hydrochloric acid solution in the desired composition is added to the suspension. When the addition is complete, the pH is increased from> 2.5 to 7.0 and stirring is continued. The product is filtered, washed, dried and calcined at a temperature range of 500 ° C. to 900 ° C. for 0.5-2 hours. The product can then be sieved as needed. A composite pigment comprising a TiO ₂ core with a coating of (Sb, Sn) O ₂ is obtained.

Coating of (Sb, Sn) O ₂ core particles with TiO ₂ is carried out in a similar process in an aqueous suspension having a pH in the range of 1.5 to 2.5 using a suitable titanium salt such as TiCl _4. be able to.

  The described composite pigments are used as LDS additives in each polymer composition, in each case 0.1 to 30% by weight, preferably 0.5 to 15% by weight, based on the total weight of the polymer composition In particular 1 to 10% by weight. They can also be used in polymer compositions suitable for LDS, mixed with other LDS additives known in the prior art. In the latter case, the proportion of LDS additive according to the invention is reduced by the proportion of other LDS additive (s). In total, the proportion of LDS additive is generally not greater than the 30% by weight indicated above, based on the total weight of the polymer composition suitable for LDS.

  The polymer composition is preferably a thermoplastic polymer composition comprised of a major proportion of thermoplastic (generally> 50% by weight).

  Suitable thermoplastic resins include a wide variety of polyamides (PA), polycarbonates (PC), polyphthalamides (PPA), polyphenylene oxides (PPO), polybutylene terephthalates (PBT), cycloolefin polymers (COP), liquid crystal polymers (LCP), or copolymers or mixtures thereof, for example, acrylonitrile-butadiene-styrene / polycarbonate blends (PC / ABS) or PBT / PET, with a large choice of materials, amorphous and semi-crystalline thermoplastics Resin. They are all available from well-known polymer manufacturers in quality suitable for LDS.

  Furthermore, the polymer composition comprising the composite pigment used according to the invention as an LDS additive optionally contains fillers and / or colorants, as well as stabilizers, assistants and / or flame retardants. Can additionally be included.

Suitable fillers are, for example, various silicates, SiO _2, is talc, kaolin, mica, wollastonite, glass fibers, glass beads, and carbon fibers.

Suitable colorants are both organic dyes and inorganic or organic color pigments. Since LDS plastic compositions with LDS additives according to the present invention are very light in color and can therefore be easily colored, virtually any soluble dye or insoluble color pigment suitable for plastics is used. can do. Examples which can be mentioned here are simply the white pigments TiO ₂ , ZnO, BaSO ₄ and CaCO _3, which are particularly frequently used. The amount and type of filler and / or colorant added here is only limited here by the specific material properties of the individual compositions suitable for LDS, in particular the plastics used. .

Surprisingly, the composite pigment used according to the invention consisting of at least 80% by weight of TiO ₂ and (Sb, Sn) O ₂ , based on the total weight of the composite pigment, is very highly suitable as an LDS additive, Although the composite pigments have a certain electrical conductivity, the polymer of the article to be produced, even in polymer compositions for LDS processes where they are added at a conventional use concentration of 0.1 to 30% by weight It has been found that it does not result in the formation of electrical conduction paths in the substrate or in the polymer-containing coating on the substrate. In addition, they have a pale, white-gray to bluish gray intrinsic color that does not impart a coherent dark intrinsic color to the plastic to which they are added. The L ^* value (brightness value) measured in the CIELab ^* system of plastics simply containing the additive of the present invention at a concentration of 2% by weight on a plastic basis is greater than 65 as measured using Minolta CR-300. Plastics suitable for LDS containing LDS additives according to the present invention use all chromatic colorants as needed, without using large amounts of colorants that reduce or negate the effectiveness of LDS additives. In this way, it can be colored. At the same time, however, the LDS additive used in accordance with the present invention has a high laser activity, and when subjected to a laser in the LDS process, results in a desirable fine roughened surface within the conductive structure ablated and carbonized by the laser beam, and high Allows subsequent metallization in quality. Under the best conditions, excellent metallization is particularly possible, just as surprisingly as very good metallability with a wide bandwidth of various laser settings. The conditions of laser action that are most suitable for the situation that actually exists can be selected in each case for the LDS process without resulting in the quality degradation expected in the case of subsequent metallization. The employed LDS additive is a particularly preferred embodiment of the invention, namely a composite pigment having a TiO ₂ core and a coating consisting of or at least mainly comprising antimony-doped tin dioxide located on the surface of the core. In some cases, use as an LDS additive in plastic-containing polymer compositions does not cause any degradation of the organic polymer molecules surrounding the composite pigment.

However, as already mentioned above, a composition suitable for LDS that contains the LDS additive used according to the invention and does not contain further conductive components is useful in the high frequency range (HF band, 1-20 GHz). The fact that this condition is met is particularly surprising. To achieve this, the plastic composition has a relatively low relative dielectric constant ε ′ _r (ratio of the dielectric constant of the medium to vacuum) and a low dielectric loss factor tan δ (the medium is in an electric field). It must have a measure of the energy loss that occurs. Both parameters are both frequency dependent and temperature dependent and should therefore be measured under conditions of use in which electronic components manufactured by the LDS method normally function. For high frequency applications, suitable measurement conditions are therefore a frequency of at least 1 GHz at room temperature. When measured at a frequency of 1 GHz or higher, the dielectric loss factor of compositions suitable for LDS given LDS additive should not be less than 0.01 if these polymer compositions are suitable for high frequency applications. Don't be. A polymer composition, in particular a thermoplastic composition, which contains the LDS additive used according to the invention in the above amounts and does not contain any further conductive components, satisfies the conditions.

The present invention also relates to a polymer composition comprising at least one organic polymer plastic and an LDS additive, wherein the LDS additive is at least 80% by weight titanium dioxide (TiO ₂ ), based on the total weight of the composite material. And a composite pigment made of antimony-doped tin dioxide ((Sb, Sn) O ₂ ). Here, the polymer composition contains the LDS additive in a proportion of 0.1 to 30% by weight, based on the total weight of the polymer composition.

  Details regarding the material composition of the LDS additive, the polymer material used, and the existing auxiliaries and additives such as fillers, colorants, etc. have already been mentioned above. They are referenced here.

  The polymer composition of the present invention is intended for use in an LDS process (laser direct structuring process) to produce a metallized circuit structure on a three-dimensional plastic substrate or a three-dimensional substrate bearing a plastic-containing coating. It has a light intrinsic color that can be colored with conventional dyes and / or color pigments if necessary, without the use of colorants, and is very suitable for use in high frequency applications The addition of the LDS additive of the present invention provides good metallization to the conductive structure produced by a laser beam whose laser parameters can be selected over a broad spectrum.

The present invention also relates to an article having a circuit structure manufactured by an LDS process, the article comprising a substrate of an article having a polymer substrate or a polymer-containing coating, and a metal conductor track disposed on the surface of the substrate. The polymer substrate or the polymer-containing coating of the substrate comprises a composite pigment comprising at least 80% by weight of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide ((Sb, Sn) O ₂ ), based on the total weight of the composite pigment Contains LDS additives. Such articles, particularly those comprising organic plastics, are used, for example, in telecommunications, medical technology, or in the manufacture of automobiles, where they are, for example, mobile phones, hearing aids, dental instruments, automotive electronics, etc. Used as an electronic component.

  FIG. 1 shows an SEM photograph of the LDS additive of the invention according to Example 1.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example 1:
Production of composite pigments:
100 g of substantially spherical TiO ₂ particles (product of Kronos 2900, KRONOS Inc.) having an average particle size in the range of 100-300 nm (measured under standard conditions by laser diffraction using a measuring instrument Marvern 2000 of Malvern Ltd., UK) Is heated to 75 ° C. with stirring in 2 liters of deionized water. The pH of the suspension is adjusted to a value of 2.0 using 10% hydrochloric acid. A solution of tin antimony chloride in hydrochloric acid consisting of 264.5 g of 50% SnCl ₄ solution, 60.4 g of 35% SbCl ₃ solution and 440 g of 10% hydrochloric acid was then slowly metered in and simultaneously with 32% hydroxylation. Sodium solution is added slowly to keep the pH of the suspension constant. When the addition is complete, the mixture is stirred for an additional 15 minutes. Subsequently, the pH is adjusted to a value of 3.0 by addition of 32% sodium hydroxide solution and the mixture is stirred for a further 30 minutes.

  The product is filtered, washed, dried and calcined at a temperature of 500-900 ° C. for 30 minutes. And it sifts through a 50 micrometer sieve.

A composite pigment comprising TiO ₂ and (Sb, Sn) O ₂ having a particle size in the range of 0.1 to 1.7 μm, a D ₅₀ value of 0.18 μm and a D ₉₀ value of 0.74 μm is obtained. The composite pigment is a light green-gray mass tone. The Sn: Sb ratio in the coating layer is 85:15.

Use example 1:
Measurement of luminance value corresponding to L ^* in the CIELab ^* system, measured using a Minolta CR-300 measuring instrument manufactured by Minolta Co., Ltd .:
Using a co-rotating twin screw extruder, 5% by weight of LDS additive is compounded into PC / ABS (Mitsubishi Engineering Plastics Xantar C CM406). The extrudate is strand pelletized and subsequently dried at 100 ° C. A test plate with dimensions 60 × 90 × 1.5 mm is then injection molded in an injection molding machine.

The luminance value L ^* of the CIELab system is measured using a Minolta CR-300 measuring instrument under standard conditions. In each case, an average of 5 different measurements is shown.

  The following values are measured:

  (Minatec® 51 and Iriotec® 8825 are products of Merck and the particle sizes in Table 1 for the comparative examples are rounded in each case, and Example 2 according to the invention. In which only 2.5% by weight of additives are used.)

  It can be seen from Table 1 that the composite pigment used in the present invention has a significantly higher luminance value in the polymer plastic matrix than the granules made of antimony-doped tin dioxide. Compared to mica coated with antimony-doped tin dioxide, in the examples according to the invention the brightness values are slightly better than in the comparative examples at half and the same LDS additive concentration.

Use case 2:
Check metallization characteristics:
As in Use Example 1, in each case, 5% by weight of LDS additive (copper spinel, material of Comparative Example 4 and material of Example 1 of the present invention) was compounded into PC / ABS using an extruder, A test plate is produced from the obtained compound in an injection molding machine. The test plate is in a test field in a grid in a manner such that slight ablation occurs at the same time as carbonization in the process area, with various laser intensities and frequencies ranging from 3 to 16 W and 60 to 100 kHz. , 1064 nm fiber laser. Copper metallization is then performed in a commercially available reduced copper bath (MID Copper 100 B1, MacDermid). The metallization properties are evaluated with reference to the structure of the copper layer on the substrate. The plating index (according to MacDermid), which is derived from the ratio of the build-up copper layer of the test material to the build-up copper layer of the reference material, is shown. The reference material is a 5% by weight copper spinel PBT test plate.

  From the mica flakes of Comparative Example 4 where the LDS additive used according to the invention is coated with antimony-doped tin dioxide with respect to metallization within the laser parameters and with respect to nominal values of the plating index Experiments show that it exhibits significantly better values, peak values are comparable to Cu spinel, and very good metallization values, especially at relatively high laser powers. .

Use Case 3:
Measurement of materials for HF compatibility:
A test plate similar to Use Example 2 is measured with the difference that no laser treatment and metallization occur before measurement.

  The dielectric constant of the material is measured at various frequency ranges using various methods. The measurement is performed at room temperature. For measurements in the 1 MHz to 1 GHz frequency range, an Agilent E4991A impedance analyzer is used in combination with an Agilent 16453 test holder. The evaluation is performed using “Material Measurement Firmware” of E4991A.

  For the measurements at 2.69 GHz and 3.9 GHz, a high quality resonator (TE111 mode cavity resonator) is adopted, and the resonance characteristics of the resonator including the empty resonator and the dielectric sample are Rhode & Schwarz. Measured using a ZVA network analyzer.

  Evaluation is based on S.E. Zinal and G.M. Boeck, “Complex Permitability Measurements using TE11p Modes in Circular Cylindrical Cavities,” IEEE Trans. Microwave Theory Tech. , Vol. 53, pp. 1870-1874, June 2005, according to the calculation procedure.

  The following measured values are obtained for a frequency of 1 GHz.

  The following measurements are obtained for a frequency of 2.69 GHz.

  The following measurements are obtained for a frequency of 3.9 GHz.

  As the measurement results show, the copper spinel commonly used as an LDS additive and the LDS additive of Example 1 used according to the present invention are comparable in terms of compatibility at high frequencies, while antimony-doped tin dioxide The coated mica flakes (Comparative Example 4) have an excessively high dielectric constant and a significantly excessively high dielectric loss factor at frequencies> 1 GHz.

2 shows an SEM photograph of the LDS additive of the invention according to Example 1.

Claims (16)

At least 80% by weight of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide ((Sb, Sn) O as a LDS additive (laser direct structuring additive) in the polymer composition, based on the total weight of the composite pigment Use of a composite pigment comprising ₂ ).   Use according to claim 1, characterized in that the composite pigment has at least one core and a coating disposed on the core.   Use according to claim 1 or 2, characterized in that the core has an isotropic shape.   The core is in the form of a sphere, a cuboid, a regular polyhedron having a n-plane or a semi-regular polyhedron, where n is in the range of 4 to 92 or in the form of granules. Use according to any one of. Use according to any of claims 1 to 4, characterized in that the core consists of TiO ₂ and has a coating comprising (Sb, Sn) O ₂ . Use according to any of claims 1 to 4, characterized in that the core consists of (Sb, Sn) O ₂ and has a coating comprising TiO ₂ .   Use according to any of the preceding claims, characterized in that the proportion of the coating is 20 to 70% by weight, based on the total weight of the composite pigment.   Use according to any of claims 1 to 7, characterized in that the core has a particle size in the range of 0.001 to 10 m.   Use according to any of claims 1 to 8, characterized in that the coating has a layer thickness in the range of 1 to 500 nm.   Use according to any of claims 1 to 9, characterized in that the composite pigments each consist of one or more primary particles, each primary particle having a core and a coating disposed on the core.   Use according to any of the preceding claims, characterized in that the composite pigments each have a particle size in the range of 0.1 to 20 µm.   Use according to any of claims 1 to 11, characterized in that the composite pigment is present in the polymer composition in a proportion ranging from 0.1 to 30% by weight, based on the total weight of the polymer composition. .   13. The polymer composition according to any one of claims 1 to 12, characterized in that, in addition to the LDS additive, the polymer composition contains at least one organic polymer plastic and optional fillers and / or colorants. use. A polymer composition comprising at least one organic polymer plastic and an LDS additive, wherein the LDS additive is at least 80% by weight titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide (based on the total weight of the composite pigment). A polymer composition which is a composite pigment made of (Sb, Sn) O ₂ ).   15. Polymer composition according to claim 14, characterized in that the LDS additive is present in the polymer composition in a proportion of 0.1 to 30% by weight, based on the total weight of the polymer composition. An article having a circuit structure produced by an LDS process comprising a plastic substrate or a substrate having a plastic-containing coating and a metal conductor track located on the surface of the substrate, the plastic substrate or the plastic-containing coating of the substrate Article comprising an LDS additive consisting of a composite pigment consisting of at least 80% by weight of titanium dioxide (TiO ₂ ) and antimony-doped tin dioxide ((Sb, Sn) O ₂ ), based on the total weight of the composite pigment.

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