THERMOPLASTIC COMPOSITION

Abstract

The invention relates to a thermoplastic composition comprising a thermoplastic polymer, a laser direct structuring (LDS) additive and a LDS synergist, wherein the composition comprises: (A) a thermoplastic polymer; (B) a LDS additive comprising a tin-based metal oxide; and (C) a metal salt of a phosphinic acid or a diphosphinic acid, or any mixtures thereof.

Claims

1. Thermoplastic composition comprising a thermoplastic polymer, a laser direct structuring (LDS) additive and a LDS synergist, wherein the composition comprises: (A) a thermoplastic polymer; (B) a LDS additive comprising a tin-based metal oxide; and (C) a metal salt of a phosphinic acid or a diphosphinic acid, or any mixtures thereof, in an amount of 0.5-7 wt. %, relative to the weight of the total composition.

2. Thermoplastic composition according to claim 1, wherein the composition has a CIELab colour value L* of at least 70.

3. Thermoplastic composition according to claim 1, wherein the LDS additive comprising the tin-based metal oxide is present in an amount of at least 1 wt. % with respect to the weight of the total composition.

4. Thermoplastic composition according to claim 1, wherein the metal salt (C) is present in an amount of at least 1 wt. % with respect to the weight of the total composition.

5. Thermoplastic composition according to claim 1, wherein the LDS additive comprising the tin-based metal oxide comprises a mixed metal oxide comprising at least tin and a second metal selected from the group consisting of antimony, bismuth, aluminum and molybdenum

6. Thermoplastic composition according to claim 5, wherein the weight ratio of the second metal to tin is at least 0.01:1.

7. Thermoplastic composition according to claim 1, wherein the LDS additive comprising the tin-based metal oxide comprises antimony-doped tin oxide.

8. Thermoplastic composition according to claim 1, wherein the LDS additive comprising the tin-based metal oxide comprises at least 20 wt. % of tin, relative to the total weight of the LDS additive comprising the tin-based metal oxide.

9. Thermoplastic composition according to claim 1, wherein the thermoplastic polymer comprises a polymer selected from the group consisting of a polyamide, a polyester, a polycarbonate and any mixtures thereof.

10. Thermoplastic composition according to claim 1, wherein the metal salt (C) comprises a metal selected from the group consisting of aluminum, zinc, and a mixture thereof.

11. Thermoplastic composition according to claim 1, wherein the composition comprises a reinforcing agent, preferably comprising a fibrous reinforcing agent, more preferably glass fibers.

12. Thermoplastic composition according to claim 1, wherein the composition comprises (A) 30-80 wt. % of the thermoplastic polymer; (B) 1-15 wt. % of the LDS additive comprising the tin-based metal oxide; (C) 1-5 wt. % of the metal salt of phosphinic acid or diphosphinic acid, or any mixtures thereof, (D) 0-60 wt. % of a reinforcing agent; wherein the sum of (A), (B), (C) and (D) is at most 100 wt. %, and wherein the weight percentages (wt. %) are relative to the weight of the total composition.

13. Thermoplastic composition according to claim 1, wherein the composition comprises one or more further components (E) in a total amount of 0-30 wt. %, relative to the total weight of the composition, and wherein the sum of (A), (B), (C), (D) and (E) is 100 wt. %.

14. Molded part made of a thermoplastic composition as defined in claim 1.

15. Article selected from the group consisting of antennas, sensors, connectors and housings for electronic devices, comprising the thermoplastic composition as defined in claim 1.

16. Process for producing a circuit carrier by laser direct structuring, comprising providing a molded part containing a thermoplastic composition as defined in claim 1, irradiating areas of said part on which conductive tracks are to be formed with laser radiation, and subsequently metalizing the irradiated areas.

Description

EXAMPLES

[0087] The compositions of Example I and II and Comparative Example A and B, shown in Table 1 and 2 were prepared by melt-blending with the constituting components on a Werner & Pfleiderer ZE-25 twin screw extruder using a 330 C. flat temperature profile. The constituents were fed via a hopper, glass fibers were added via a side feed. Throughput was 20 kg/h and screw speed was 200 rpm. The settings typically resulted in a measured melt temperature between about 320 and about 350 C. The polymer melt was degassed at the end of the extruder. The melt was extruded into strands, cooled and chopped into granules.

[0088] The compositions of Example III and Comparative Example C, shown in Table 1 and 2 were prepared in the same manner as above. The settings were adopted for standard glass fiber reinforced polyester compositions.

Injection Molding of Test Bars

[0089] Dried granulate material was injection molded in a mold to form test bars with a thickness of 4 mm conforming ISO 527 type 1A for tensile testing, ISO 179/1 eU for unnotched Charpy testing, ISO 179/1 eA for notched Charpy testing and ISO 75 for HDT testing. For the compositions of Example I and II and Comparative Experiments A and B the temperature of the melt in the injection molding machine was 340 C. The temperature of the mold was 100 C.

[0090] For the compositions of Example III and Comparative Experiment C the temperature of the melt in the injection molding machine and the temperature of the mold were adjusted using standard conditions for adopted for standard glass fiber reinforced polyester compositions.

Test Bars for Mechanical Testing

[0091] The test bars were used to measure the mechanical properties of the compositions. All tests were carried out on test bars dry as made. The compositions and main test results have been collected in Tables 1 and 2.

LDS Performance

[0092] The LDS behavior was tested with a 20W laser, applying different power levels ranging from 50% to 90% of the maximum laser power (max 20 W) and different pulsing frequencies (60 kHz, 80 kHz and 100 kHz), with a laser spot size of 40 m diameter. Plating was done with a standard Ethone Plating bath with Cu only with a plating time of 10 minutes. Plating thickness was measured with 300 micron diameter X-ray beam, averaged over 3 different measurements for each of the process conditions. The measurements were based on calibrated data for copper films with certified thickness values. Results are given in Table 1.

TABLE-US-00001 TABLE 1 Compositions and test results for compositions of Examples I-III (with LDS additive and synergist) and Comparative Experiments A-C (with LDS additive, without synergyst): LDS plating performance/L-value of compounds EX-I EX-II EX-III CE-A CE-B CE-C LDS 5 4 5 3 2-3 3 Performance L-Value Very High- Very High- High High- high very high very very high high high Legend: 1 = poor, 5 = excellent