Improving the flowability of thermoconductive polycarbonate compositions

Patent metadata

Field	Value
Publication number	US-10472516-B2
Application number	US-201615742631-A
Country	US
Kind code	B2
Filing date	Jul 5, 2016
Priority date	Jul 8, 2015
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

The present invention relates to the use of diglycerol esters to enhance the flowability of graphite-containing, thermally conductive polycarbonate compositions. Melt viscosities and melt volume flow rates are improved.

First claim

The invention claimed is:

1. A polycarbonate composition comprising
A) 20 wt % to 94.8 wt % of an aromatic polycarbonate,
B) 5 to 40 wt % of graphite and
C) 0.2 wt % to 3.0 wt % of diglycerol ester.

2. The polycarbonate composition according to claim 1 comprising 0.2 to 1.2 wt % of diglycerol ester.

3. The polycarbonate composition according to claim 1 , characterized in that as diglycerol ester an ester of formula (I) is present

where R ═COC n H 2n+1 and/or R═COR′,
wherein n is an integer and R′ is a branched alkyl radical or a branched or unbranched alkenyl radical and C n H 2n+1 is an aliphatic, saturated linear alkyl radical.

4. The polycarbonate composition according to claim 3 , characterized in that R═COC n H 2n+1 wherein n is an integer from 6-24.

5. The polycarbonate composition according to claim 1 , wherein the diglycerol ester is diglycerol monolauryl ester or a mixture of diglycerol monolauryl ester and further diglycerol esters.

6. The polycarbonate composition according to claim 1 , wherein the graphite is an expanded graphite or a mixture of an expanded graphite with further graphite.

7. The polycarbonate composition according to claim 1 , wherein the composition consists of
A) 74.0 wt % to 85.0 wt % of aromatic polycarbonate,
B) 5 to 25 wt % of graphite,
C) 0.2 to 1.2 wt % of diglycerol ester,
D) optionally up to 1.0 wt % of heat stabilizer and/or transesterification stabilizer and/or
E) optionally up to 10.0 wt % of one or more further additives selected from the group consisting of flame retardants, anti-dripping agents, antioxidants, inorganic pigments, carbon black, dyes, inorganic fillers, titanium dioxide, silicates, talc, barium sulfate, demolding agents, and combinations thereof.

8. The polycarbonate composition according to claim 1 , wherein the composition consists of
A) 74.0 wt % to 79.6 wt % of aromatic polycarbonate,
B) 20 to 25 wt % of graphite,
C) 0.2 to 1.2 wt % of diglycerol ester,
D) optionally up to 1.0 wt % of heat stabilizer and/or transesterification stabilizer and/or
E) optionally up to 10.0 wt % of one or more further additives selected from the group consisting of flame retardants, anti-dripping agents, antioxidants, inorganic pigments, carbon black,r dyes, inorganic fillers, titanium dioxide, silicates, talc, barium sulfate, demolding agents, and combinations thereof.

9. Polycarbonate composition according to claim 7 , characterized in that the amount of diglycerol ester is from 0.8 to 1.2 wt %.

10. A method comprising adding at least one diglycerol ester to enhance the melt volume flow rate determined as per DIN EN ISO 1133 (DIN EN ISO 1133-1:2012-03) at a test temperature of 300° C. with a mass of 1.2 kg to a thermally conductive polycarbonate composition comprising graphite.

11. The method according to claim 10 , characterized in that the melt viscosity, determined as per ISO 11443, of the polycarbonate compositions is reduced by the diglycerol ester.

12. The polycarbonate composition according to claim 3 , characterized in that R═COC n H 2n+1 wherein n is an integer from 8 to 18.

13. The polycarbonate composition according to claim 3 , characterized in that R═COC n H 2n+1 wherein n is an integer from 10 to 16.

14. The polycarbonate composition according to claim 3 , characterized in that R═COC n H 2n+1 wherein n is 12.

Assignees

• Covestro Deutschland Ag
• Coverstro Deutschland Ag

Inventors

• Heuer Helmut Werner
• Wehrmann Rolf
• Boumans Anke
• Erkelenz Michael

Classifications

• C08L69/00 Primary

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title

• C08K3/013

  Fillers, pigments or reinforcing additives · CPC title

• C08K5/103 Primary

  with polyalcohols · CPC title

• C08K2201/001

  Conductive additives · CPC title

• C08K2003/2241

  Titanium dioxide · CPC title