IMPACT-MODIFIED POLYCARBONATE COMPOSITIONS FOR THE PRODUCTION OF METALLISED MOULDINGS WITH HOMOGENEOUS SURFACE GLOSS

• US 20100267889A1
• Filed: 03/23/2010
• Published: 10/21/2010
• Est. Priority Date: 03/26/2009
• Status: Active Grant

• Current Assignee: Covestro Deutschland AG
• Original Assignee: Bayer Materialscience AG (Covestro AG)
• Inventors: Klankers, Hans-Jürgen, Wenz, Eckhard, SEIDEL, Andreas
• Granted Patent: US 8,703,869 B2
• Time in Patent Office: Days
• US Class Current: 524/504
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 51/04 grafted on to rubbers
• CPC Class Codes: C08L 55/02 ABS [Acrylonitrile-Butadiene-Styrene] polymers
• CPC Class Codes: C08L 69/00 Compositions of polycarbonates; Compositions of derivatives of polycarbonates
• CPC Class Codes: C08L 69/005 Polyester-carbonates

Abstract

The invention relates to impact-modified polycarbonate compositions which are distinguished by high heat resistance and good melt flow behaviour. In addition, the mouldings produced from the compositions according to the invention in an injection-moulding process can be metallised, the resulting metallised mouldings having a surface with a particularly high and, in particular, homogeneous gloss. The invention thus also provides the metallised mouldings produced from the compositions according to the invention.

Claims

1. A composition comprising

A) 55 to 90 parts by weight (based on the sum of the parts by weight of components A, B and C) of aromatic polycarbonate and/or aromatic polyester carbonate with a relative solution viscosity, measured in methylene chloride, of 1.20 to 1.30,

B) 10 to 45 parts by weight (based on the sum of the parts by weight of components A, B and C) of rubber-modified component comprising

B.1) at least one graft polymer, produced by emulsion polymerisation, by graft polymerisation of

B.1.1) 5 to 95 wt.%, based on the sum of B.1.1 and B.1.2, of at least one vinyl monomer on

B.1.2) 95 to 5 wt. %, based on the sum of B.1.1 and B.1.2, of one or more particulate rubbers as backbones with glass transition temperatures of <

0°

C.,

B.2) optionally a rubber-free vinyl (co)polymer,

B.3) optionally a graft polymer of at least one vinyl monomer on at least one rubber backbone with a glass transition temperature of <

0°

C., produced by a bulk, solution or bulk-suspension polymerisation process,

wherein the graft polymers B.1 and B.3, in addition to graft particles, may optionally also comprise as a result of their production free (co)polymer of the vinyl monomers, that are not chemically bonded to the rubber particles and/or included in the graft particles in a form that is insoluble in organic solvents,

C) 0 to 25 parts by weight (based on the sum of the parts by weight of components A, B and C) of polymer additives,

wherein

(i) the rubber content of the polycarbonate composition is 1 to 6 wt. %, and

(ii) at least 40 wt. % of the graft particles in component B have a diameter (measured by ultracentrifuge) of up to 200 nm.

2. A composition according to claim 1 with a rubber content of the polycarbonate composition of 2.5 to 5.0 wt. %.

3. A composition according to claim 1, wherein at least 50 wt. % of the graft particles in component B have a diameter (measured by ultracentrifuge) of up to 200 nm.

4. A composition according to claim 3, wherein up to 25 wt. % of the graft particles in component B have a diameter (measured by ultracentrifuge) of over 400 nm.

5. A composition according to claim 3 in which component A has a relative solution viscosity, measured in methylene chloride, of 1.23 to 1.27.

6. A composition according to claim 3 comprising 63 to 80 parts by weight (based on the sum of the parts by weight of components A, B and C) of component A.

7. A composition according to claim 3 comprising 65 to 75 parts by weight (based on the sum of the parts by weight of components A, B and C) of component A.

8. A composition according to claim 3, wherein component B.1 is a graft polymer of

B.1.1) 25 to 60 wt. % (based on the sum of the wt. % of B.1.1 and B. 0.2) of a mixture of

B.1.1.1) 50 to 99 wt. % (based on the sum of the wt. % of B.1.1.1 and B.1.1.2) of at least one monomer selected from the group consisting of vinyl aromatics and/or ring-substituted vinyl aromatics and methacrylic acid (C₁-C₈) alkyl esters and

B.1.1.2) 1 to 50 wt. % (based on the sum of the wt. % of B.1.1.1 and B.1.1.2) of at least one monomer selected from the group consisting of vinyl cyanides, (meth)acrylic acid (C₁-C₈) alkyl esters, unsaturated carboxylic acids and/or derivatives of unsaturated carboxylic acids

on

B.1.2) 75 to 40 wt. % (based on the sum of the wt % of B.1.1 and 8.1.2) of one or more backbones with glass transition temperatures of <

−

20°

C.

9. A composition according to claim 8, wherein component B.1 is an ABS or MBS graft polymer with a core-shell structure.

10. A composition according to claim 3, which is free from component B.3.

11. A composition according to claim 3 comprising as component C) 0.1 to 5 parts by weight (based on the sum of the parts by weight of components A, B and C) of at least one additive selected from the group consisting of internal and external lubricants and mould release agents, flow auxiliaries, antistatic agents, conductivity additives, stabilisers, antibacterial additives, scratch resistance improving additives, IR absorbers, optical brighteners, fluorescent additives, dyes and pigments and Brö

nsted acid compounds.

12. A component produced from or comprising a composition according to claim 1.

13. A metallised moulding with a surface which is at least partly curved concavely or convexly on a metallised side thereof which is produced from a composition of claim 1.

14. A composition according to claim 1, which has a melt viscosity of not more than 230 Pas, measured in accordance with ISO 1143 at a melt temperature of 260°

C. and a shear rate of 1000 s<sup>−

1</sup>, and which is capable for the production of a metallised moulding having a surface which is at least partly curved concavely or convexly on a metallised side thereof.

15. A lamp housing with a reflector functionality comprising a composition according to claim 1.