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1. (WO2018122078) POLYCARBONATE COMPOSITE HAVING AN INCREASED PENCIL HARDNESS
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Claims

1. A polycarbonate composite, comprising:

a) a polycarbonate substrate, prepared from a thermoplastic aromatic (co)polycarbonate having a glass-transition temperature in the range of 160 to 210 °C; and

b) a coating on said polycarbonate substrate, said coating being formed by curing a polysiloxane-based thermosetting coating material at a temperature in the range of 140 to 210 °C for 0.5 to 2 hours;

wherein said polycarbonate composite has a pencil hardness higher than H, as measured according to ASTM D3363.

2. The polycarbonate composite according to claim 1, wherein said polycarbonate substrate is prepared by an injection compression molding process.

3. The polycarbonate composite according to claim 1 or 2, wherein said thermoplastic aromatic (co)polycarbonate has a weight-average molecular weight of at least 15,000 g/mol, and comprises a structure unit of formula (I),


wherein

Ra and Rb, independently of each other, represent hydrogen or C1-C4-alkyl,

k represents 0, 1, 2, 3 or 4.

4. The polycarbonate composite according to claim 3, wherein the structure unit of formula (I) has the following structure (IX),

5. The polycarbonate composite according to any one of the preceding claims, wherein said coating has a thickness in the range of 5 to 40 μπι.

6. The polycarbonate composite according to any one of the preceding claims, wherein said polycarbonate composite is transparent.

7. A method for producing the polycarbonate composite according to any one of the preceding claims, comprising:

I) providing a polycarbonate substrate prepared from a thermoplastic aromatic (co)polycarbonate having a glass-transition temperature in the range of 160 to 210 °C; and

II) applying a polysiloxane-based thermosetting coating material onto the polycarbonate substrate, and then curing at a curing temperature in the range of 140 to 210 °C for 0.5 to 2 hours, to produce said polycarbonate composite.

8. An article produced from the polycarbonate composite according to any one of claims 1 to 6.

9. The article according to claim 8, wherein said article is selected from the group consisting of housings of electronic or electrical equipment, instrument panels, touch screens, display screens and lenses.