Flame-retardant polycarbonate composition

Patent metadata

Field	Value
Publication number	US-11708455-B2
Application number	US-202117997748-A
Country	US
Kind code	B2
Filing date	May 14, 2021
Priority date	May 22, 2020
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

The present invention relates to a flame-retardant polycarbonate composition comprising the following components, relative to the total weight of the composition:A) 30-70 wt. % of at least one aromatic polycarbonate,B) 20-60 wt. % of at least one polysiloxane-polycarbonate block condensate,C) 0.5-5 wt. % of at least one cyclic phosphazene,D) 1-5 wt. % of at least one silicone-acrylate rubber based impact modifier,E) 0.3-3 wt % of kaolin,F) 0.1-1 wt. % of at least one anti-dripping agent, andG) 0.1-1 wt. % of at least one UV absorber.The present invention also relates to a shaped article produced from the composition. The polycarbonate composition according to the present invention has a good combination of low-temperature impact performance, flame-retardancy, hydrolytic stability, anti-UV performance, and heat resistance.

First claim

The invention claimed is:

1. A flame-retardant polycarbonate composition comprising the following components, relative to the total weight of the composition:
A) 30-70 wt. % of at least one aromatic polycarbonate,
B) 20-60 wt. % of at least one polysiloxane-polycarbonate copolymer,
C) 0.5-5 wt. % of at least one cyclic phosphazene,
D) 1-5 wt. % of at least one silicone-acrylate rubber based impact modifier,
E) 0.3-3 wt % of kaolin,
F) 0.1-1 wt. % of at least one anti-dripping agent, and
G) 0.1-1 wt. % of at least one UV absorber.

2. The composition according to claim 1 , wherein the polysiloxane-polycarbonate copolymer comprises siloxane blocks derived from the following structure (XIII) and/or (XIV):

wherein
R1 independently of one another represents hydrogen, Cl, Br, or C 1 -C 4 -alkyl,
R2 independently of one another represents aryl or C 1 -C 13 alkyl,
X represents a single bond, —O—, —SO—, —CO—, —S—, —SO 2 —, C 1 -C 6 -alkylene, C 2 -C 5 -alkylidene, C 5 -C 12 -cycloalkylidene, or C 6 -C 12 -arylene which may optionally be fused to aromatic rings containing further heteroatoms,
n represents an average number from 10 to 400, in each case determined by 1H-NMR spectroscopy and
m represents an average number from 1 to 10, in each case determined by 1H-NMR spectroscopy.

3. The composition according to claim 1 , wherein the polysiloxane-polycarbonate copolymer comprises a proportion of 2 wt. % to 20 wt. % of siloxane blocks, relative to the weight of the polysiloxane-polycarbonate copolymer.

4. The composition according to claim 1 , wherein the cyclic phosphazene is selected from cyclic phosphazenes of formula (V):

wherein
k is an integer from 1 to 10,
the trimer content (k=1) of from 60 to 100 mol %, based on component C),
and wherein
R is in each case identical or different and represents
an amine radical,
C 1 -C 8 -alkyl, in each case optionally halogenated,
C 1 -C 8 -alkoxy,
C 5 -C 6 -cycloalkyl in each case optionally substituted by alkyl,
C 6 -C 2 O-aryloxy, in each case optionally substituted by alkyl,
C 7 -C 12 -aralkyl, in each case optionally substituted by alkyl, and/or halogen,
a halogen radical, or
an OH radical.

5. The composition according to claim 4 , wherein the cyclic phosphazene is selected from the group consisting of propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene, and fluoroalkylphosphazene.

6. The composition according to claim 1 , wherein the silicone-acrylate rubber based impact modifier comprises,
D.1) 5 wt. % to 95 wt. %, of at least one vinyl monomer on
D.2) 95 wt. % to 5 wt. %, of one or more silicone-acrylate rubbers as a graft base, and wherein
wt. % is calculated based on the weight of the impact modifier.

7. The composition according to claim 6 , wherein the vinyl monomer D.1 is selected from vinylaromatics, vinylaromatics substituted on the nucleus, vinyl cyanides, (meth)acrylic acid (C 1 -C 8 )-alkyl esters, and derivatives of unsaturated carboxylic acids, and
the silicone-acrylate rubber D.2 is selected from composite rubbers having graft-active sites containing 5 wt. %-95 wt. %, of silicone rubber proportion and 95 wt. % to 5 wt. %, of polyalkyl (meth)acrylate rubber proportion, relative to the total weight of the composite rubber.

8. The composition according to claim 1 , wherein the silicone-acrylate rubber based impact modifier is a methyl methacrylate-grafted silicone-butyl acrylate rubber.

9. The composition according to claim 1 comprising the following components, relative to the total weight of the composition:
A) 35-66 wt. % of at least one aromatic polycarbonate having a weight-average molecular weight of 23,000 to 28,000 g/mol,
B) 25-56 wt. % of at least one polysiloxane-polycarbonate copolymer,
C) 1.5-4.5 wt. % of at least one cyclic phosphazene,
D) 1-4 wt. % of (meth)acrylic acid (C 1 -C 8 )-alkyl ester-grafted silicone-C 1 -C 8 alkyl acrylate rubber,
E) 0.5-1.5 wt % of kaolin,
F) 0.5-1 wt. % of at least one anti-dripping agent, and
G) 0.25-0.6 wt. % of at least one UV absorber.

10. The composition according to claim 1 , wherein the anti-dripping agent is selected from fluorinated polyolefins.

11. The composition according to claim 1 , further comprising one or more additional additives selected from the group consisting of lubricants and demoulding agents, antioxidants, antistatic agents, dyestuffs, and pigments.

12. A shaped article produced from the composition according to claim 1 .

13. A process for preparing a shaped article comprising injection moulding, extrusion moulding, blowing moulding or thermoforming the polycarbonate composition according to claim 1 .

Assignees

• Covestro Deutschland Ag

Inventors

• Huang Zhenyu
• Han Hao

Classifications

• C08G64/04 Primary

  Aromatic polycarbonates · CPC title

• C08F14/26

  Tetrafluoroethene · CPC title

• C08F220/14

  Methyl esters {, e.g. methyl (meth)acrylate} · CPC title

• C08F220/1804

  C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate · CPC title

• C08F230/085

  the monomer being a polymerisable silane, e.g. (meth)acryloyloxy trialkoxy silanes or vinyl trialkoxysilanes · CPC title