Polycarbonate composition comprising pearlescent pigment and/or interference pigment

Patent metadata

Field	Value
Publication number	US-2021102062-A1
Application number	US-201816608324-A
Country	US
Kind code	A1
Filing date	Apr 25, 2018
Priority date	Apr 28, 2017
Publication date	Apr 8, 2021
Grant date	—

Abstract

The invention relates to compositions based on aromatic polycarbonate comprising metal oxide-coated micas as effect pigment, which do not have any significant increase in molecular weight of the polycarbonate, as can be seen from the MVR, under thermal stress. This is achieved by the addition of small amounts of an anhydride-modified α-olefin polymer, optionally in combination with phosphorus-containing thermal stabilizer.

First claim

1 .- 15 . (canceled)

16 . A composition comprising
A) 50 wt % to 98.5 wt % of aromatic polycarbonate, B) 0.8 wt % to ≤3.0 wt % of interference pigment and/or pearlescent pigment from the group of the metal oxide-coated micas, and C) 0.05 wt % to ≤3 wt % of anhydride-modified α-olefin polymer.

17 . The composition according to claim 16 , comprising
A) 90.0 wt % to 97.5 wt % of aromatic polycarbonate, B) 1.0 to 2.5 wt % of interference pigment and/or pearlescent pigment from the group of the metal oxide-coated micas, C) 0.2 wt % to ≤1 wt % of anhydride-modified α-olefin polymer.

18 . The composition according to claim 16 , comprising 1.2 to 2.0 wt % of interference pigment and/or pearlescent pigment from the group of the metal oxide-coated micas.

19 . The composition according to claim 16 , wherein the composition comprises
D) 0.001 wt % to 0.500 wt % of one or more phosphorus-containing thermal stabilizers.

20 . The composition according to claim 19 , wherein component D comprises one or more phosphites as thermal stabilizer.

21 . The composition according to claim 19 , wherein component D comprises
i) phosphine, phosphite and phenolic antioxidant or ii) phosphine, phosphonite and phenolic antioxidant as phosphorus-containing thermal stabilizers.

22 . The composition according to claim 16 , wherein the thermal stabilizer present is bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite.

23 . The composition according to claim 16 , wherein the anhydride-modified α-olefin polymer has been modified with maleic anhydride and is based on ethene, propene and/or 1-octene.

24 . The composition according to claim 16 , wherein the olefinic portion of the anhydride-modified α-olefin polymer has
an ethylene content of 65.0-96.0 wt %,
a propylene content of 2.0-10.0 wt % and
a 1-octene content of 2.0-25.0 wt %.

25 . The composition according to claim 16 , wherein the anhydride-modified α-olefin polymer has an average molecular weight M W , determined by means of gel permeation chromatography in ortho-dichlorobenzene at 150° C. with polystyrene calibration, of 1000 to 15 000 g/mol and an acid number of 45 to 170 mg KOH/g, determined according to DIN ISO 17025, by means of potentiometric titration.

26 . The composition according to claim 16 , wherein the pearlescent pigment and/or interference pigment from the group of the metal oxide-coated micas present is anatase- or rutile-coated mica.

27 . The composition according to claim 16 , wherein the composition comprises
A) 90.0 wt % to 97.5 wt % of aromatic polycarbonate, B) 1.2 wt % to 2.0 wt % of pearlescent pigment and/or interference pigment from the group of the titanium dioxide-coated micas, C) 0.2 wt % to ≤1 wt % of anhydride-modified α-olefin polymer based on ethene, propene and/or 1-octene, D) 0.05 to 0.270 wt % of phosphorus-containing thermal stabilizer comprising
i) phosphine, phosphite and phenolic antioxidant or
ii) phosphine, phosphonite and phenolic antioxidant,
E) up to 7% by weight of further additives selected from the group consisting of flame retardants, anti-dripping agents, thermal stabilizers other than component D), impact modifiers, fillers, antistats, colourants, pigments other than component B, also including carbon black, lubricants, demoulding agents, hydrolysis stabilizers, compatibilizers, UV absorbers and/or IR absorbers.

28 . The composition according to claim 27 , wherein the composition does not comprise any further components.

29 . The composition according to claim 27 , wherein further additives optionally present according to component E are solely colourants, demoulding agents, thermal stabilizers other than component D and/or pigments other than component B.

30 . A moulding produced from a composition according to claim 16 .

Assignees

• Covestro Deutschland Ag

Inventors

• Wandner Derk Erich
• Hermsdorfer Ingmar
• Schirwitz Christopher

Classifications

• C08L23/26

  modified by chemical after-treatment (saponified copolymers C08L23/0861; unsaturated acid salts C08L23/0876) · CPC title

• C08K2003/2241

  Titanium dioxide · CPC title

• C08K5/524

  Esters of phosphorous acids, e.g. of H3PO3 · CPC title

• C08K5/50

  Phosphorus bound to carbon only · CPC title

• C08K5/13

  Phenols; Phenolates · CPC title