Flame retardant polycarbonate composition

Abstract

The present application relates to a flame retardant polycarbonate composition and shaped articles made therefrom. The polycarbonate composition comprises the following components: an optional virgin aromatic polycarbonate, a post-consumer recycled (PCR) aromatic polycarbonate, a flame retardant, two impact modifiers, a UV absorber and an anti-dripping agent. The shaped article made from the polycarbonate composition according to the present invention has a good combination of mechanical properties such as impact strength, flame retardancy, and UV resistance.

Description

[0001] FLAME RETARDANT POLYCARBONATE COMPOSITION

[0002] TECHNICAL FIELD

[0003] The present invention relates to a flame retardant polycarbonate composition. In addition, the present invention also relates to shaped articles made from the polycarbonate composition.

[0004] BACKGROUND ART

[0005] Polymers are used in a number of applications on a daily basis. On one hand, many polymeric items, e.g. packaging, medicine, electronics, end up in the waste stream, which may cause environmental pollutions and affect the health of all creatures on the earth. On the other hand, the manufacturing of polymers consumes fossil resources and generate carbon dioxide and other greenhouse gases which also lead to weather and ecological issues. Re-use and recycling of the polymers are effective to resolve these issues and has attracted the increasing industrial attentions in recent years.

[0006] Polycarbonate (PC), as a high-performance engineering plastic, has been widely used in housing of electrical and electronic devices, automotive industry, medical equipment, etc. With the rapid growth of polycarbonate production and sales, more and more polycarbonate waste has been generated. How to recycle or reuse it becomes an important issue in industry.

[0007] There are two types of recycled source for mechanical recycling. One is called post-industrial recycled (PIR) which is all sorts of scraps and wastes that generated during the polymer processing stage. Another is called post-consumer recycled (PCR) which comes from finished goods that collected from the consumers or end users. The PCR materials usually undergoes more degradation and contains more contaminations than PIR material. Thus it is more difficult to reuse and has high possibilities to be discarded. In this sense, PCR materials are more preferred to be reused and are more valuable than PIR material, since they can lead to more reduction of carbon footprint and other climate-impact substances if recycled.

[0008] Companies in electrical and electronic (E&E) industry presently are main drivers to promote the usage of recycled polymers. Many materials for E&E device housing applications require good mechanical properties and thin wall flame retardant performance as well as UV resistance. It is not an easy task to achieve all these demand- ed requirements even for virgin materials,. Thus it will be a big challenge due to relative low quality of PCR feedstock.

[0009] CN103421295A discloses a high performance flame retardant recycled plastic composition applied in chair parts for express trains. The plastic composition comprises 77.6 wt.% of recycled polycarbonate, 4 wt.% of impact modifier, 10 wt. % of ductility improver, 5 wt.% of non-halogen flame retardant agent, 2 wt.% of phosphors flame retardant, and 1 wt.% of ethylene Zvs-stearamide (EBS). However, the compositions can not be used for E&E housing application due to not enough flame retardant performance and UV resistance.

[0010] Therefore, it is still necessary to develop new PCR polycarbonate compositions, which can achieve mechanical properties such as impact strength, flame retardant property, and UV resistance comparable to those of virgin polycarbonate compositions in E&E housing applications, especially for light color E&E housing parts.

[0011] SUMMARY OF THE INVENTION

[0012] One object of the present application is thus to provide a polycarbonate composition, which has a good combination of mechanical properties such as impact strength, flame retardancy, and UV resistance.

[0013] Another object of the present application is to provide a molded article which has a good combination of mechanical properties such as impact strength, flame retardancy, and UV resistance.

[0014] Thus, in a first aspect, the present invention provides a polycarbonate composition comprising the following components, relative to the total weight of the composition:

[0015] A) from 1 wt.% to 26 wt.% of virgin aromatic polycarbonate,

[0016] B) from 60 wt.% to 78 wt.% of post-consumer recycled (PCR) polycarbonate,

[0017] C) from 11 wt.% to 21 wt.% of a flame retardant,

[0018] D) from 1 wt.% to 8 wt.% of silicone-acrylate rubber based core-shell impact modifier with a silicone content between 25 wt.% and 50 wt.% based on the siliconeacrylate rubber based core-shell impact modifier,

[0019] E) no more than 7 wt.% of acrylate-based core-shell impact modifier different from component D,

[0020] F) from 0.2 wt.% to 0.8 wt.% of UV additive, and

[0021] G) from 0.6 wt.% to 1.0 wt.% of anti-dripping agent, the content relationship index (r) of component C, component D, and component E, having the following formula, is in the range of 0.52-0.68, r = (CD*1 .2 + CE*0.8) / Cc, wherein CDrepresents the content by weight of component D in the composition;

[0022] CErepresents the content by weight of component E in the composition;

[0023] Ccrepresents the content by weight of component C in the composition.

[0024] The inventors have discovered unexpectedly that molded article made from the composition according to the present invention has impact strength of no less than 28 KJ / m2as measured according to IS0180 / A:2000, flame level of VO at a thickness of 1.0 mm as measured according to UL94:2015, and good UV resistance.

[0025] The compositions have good UV resistance, thin wall FR performance and acceptable impact strength for E&E housing applications.

[0026] According to a second aspect, the present invention provides a shaped article made from the composition according to the present invention.

[0027] According to a third aspect, the present invention provides a method for preparing the shaped article mentioned above, comprising injection moulding, extrusion moulding, blowing moulding process or thermoforming the composition according to the present invention.

[0028] The inventors have found that the article made from the composition according to the present invention has a good combination of thin wall flame retardancy, impact strength and UV resistance. It has potential applications in E&E applications, and so on.

[0029] Other subjects and characteristics, aspects and advantages of the present invention will emerge even more clearly on reading the description and the examples that follow.

[0030] DETAILED DESCRIPTION OF THE INVENTION

[0031] In that which follows and unless otherwise indicated, the limits of a range of values are included within this range, in particular in the expressions "between ... and ..." and "from ... to ...".

[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains. When the definition of a term in the present description conflicts with the meaning as commonly understood by those skilled in the art the present invention belongs to, the definition described herein shall apply.

[0033] Throughout the instant application, the term "comprising" is to be interpreted as encompassing all specifically mentioned features as well optional, additional, unspecified ones. As used herein, the use of the term "comprising" also discloses the embodiment wherein no features other than the specifically mentioned features are present (Ze. "consisting of").

[0034] Unless otherwise specified, all numerical values expressing amount of ingredients and the like which are used in the description and claims are to be understood as being modified by the term "about".

[0035] Component A

[0036] The polycarbonate composition according to the present invention may comprise a virgin aromatic polycarbonate as component A.

[0037] As used herein, virgin aromatic polycarbonate indicates pure aromatic polycarbonate, i.e., it is not specified as "post-consumer recycled polycarbonate" or "PCR polycarbonate".

[0038] According to the invention, "aromatic polycarbonates" or else just "polycarbonates" is to be understood as meaning both homopolycarbonates and copolycarbonates, in particular aromatic ones. These polycarbonates may be linear or branched in known fashion. According to the invention, mixtures of polycarbonates may also be used.

[0039] Aromatic polycarbonates selected in accordance with the invention preferably have weight-average molecular weights Mwof 15 000 to 40 000 g / mol, more preferably of 16 000 to 34 000 g / mol, even more preferably of 17 000 to 33 000 g / mol, most preferably of 19 000 to 32 000 g / mol. The values for Mwhere are determined by a gel permeation chromatography, calibrated against bisphenol A polycarbonate standards using dichloromethane as eluent, calibration with linear polycarbonates (made of bisphenol A and phosgene) of known molar mass distribution from PSS Polymer Standards Service GmbH, Germany; calibration according to method 2301 - 0257502-09D (2009 Edition in German) from Currenta GmbH & Co. OHG, Leverkusen. The eluent is dichloromethane. Column combination of crosslinked styrene- divinylbenzene resins. Diameter of analytical columns: 7.5 mm; length: 300 mm. Particle sizes of column material: 3 pm to 20 pm. Concentration of solutions: 0.2% by weight. Flow rate: 1.0 ml / min, temperature of solutions: 30°C. Detection using a refractive index (Rl) detector.

[0040] The polycarbonates are preferably produced by the interfacial process or the melt transesterification process, which have been described many times in the literature.

[0041] With regard to the interfacial process reference is made for example to H. Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Vol. 9, Interscience Publishers, New York 1964 p. 33 et seq., to Polymer Reviews, Vol. 10, "Condensation Polymers by Interfacial and Solution Methods", Paul W. Morgan, Interscience Publishers, New York 1965, Chapt. VIII, p. 325, to Dres. II. Grigo, K. Kircher and P. R- Muller "Polycarbonate" in Becker / Braun, Kunststoff-Handbuch, Volume 3 / 1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag Munich, Vienna 1992, pp. 118-145 and also to EP 0 517 044 A1.

[0042] The melt transesterification process is described, for example, in the "Encyclopedia of Polymer Science", Vol. 10 (1969), Chemistry and Physics of Polycarbonates, Polymer Reviews, H. Schnell, Vol. 9, John Wiley and Sons, Inc. (1964), and in patent specifications DE 10 31 512 A and US 6,228,973 B1.

[0043] Particulars pertaining to the production of polycarbonates are disclosed in many patent documents spanning approximately the last 40 years. Reference may be made here by way of example to Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964, to D. Freitag, U. Grigo, P.R. Muller, H. Nouvertne, BAYER AG, "Polycarbonates" in Encyclopedia of Polymer Science and Engineering, Volume 11, Second Edition, 1988, pages 648-718, and finally to U. Grigo, K. Kirchner and P.R. Muller "Polycarbonate" in Becker / Braun, Kunststoff-Handbuch, Volume 3 / 1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag Munich, Vienna 1992, pages 117-299.

[0044] The production of aromatic polycarbonates is effected for example by reaction of dihydroxyaryl compounds with carbonic halides, preferably phosgene, and / or with aromatic dicarboxyl dihalides, preferably benzenedicarboxyl dihalides, by the interfacial process, optionally using chain terminators and optionally using trifunctional or more than trifunctional branching agents, production of the polyester carbonates being achieved by replacing a portion of the carbonic acid derivatives with aromatic dicarboxylic acids or derivatives of the dicarboxylic acids, specifically with aromatic dicarboxylic ester structural units according to the carbonate structural units to be re- placed in the aromatic polycarbonates. Preparation via a melt polymerization process by reaction of dihydroxyaryl compounds with, for example, diphenyl carbonate is likewise possible.

[0045] Dihydroxyaryl compounds suitable for the production of polycarbonates are for example hydroquinone, resorcinol, di hydroxydi phenyls, bis(hydroxyphenyl)alkanes, bis(hydroxyphenyl)cycloalkanes, bis(hydroxyphenyl) sulfides, bis(hydroxyphenyl) ethers, bis(hydroxyphenyl) ketones, bis(hydroxyphenyl) sulfones, bis(hydroxyphenyl) sulfoxides, a,a'-bis(hydroxyphenyl)diisopropylbenzenes, phthalimidines derived from derivatives of isatin or phenolphthalein and the ring-alkylated, ring-arylated and ring- halogenated compounds thereof.

[0046] Preferred dihydroxyaryl compounds are 4,4'-dihydroxydiphenyl, 2,2-bis(4- hydroxyphenyl)propane (bisphenol A), 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 1,1 - bis(4-hydroxyphenyl)-p-diisopropylbenzene, 2,2-bis(3-methyl-4- hydroxyphenyl)propane, dimethylbisphenol A, bis(3,5-dimethyl-4- hydroxyphenyl)methane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, bis(3,5- dimethyl-4-hydroxyphenyl)sulfone, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2- methylbutane, 1,1 -bis(3,5-dimethyl-4-hydroxyphenyl)-p-diisopropylbenzene and 1,1 - bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and also the bisphenols (I) to (III) in which R' in each case stands for - to C4-alkyl, aralkyl or aryl, preferably for methyl or phenyl, very particularly preferably for methyl.

[0047] Particularly preferred dihydroxyaryl compounds are 2,2-bis(4- hydroxyphenyl)propane (bisphenol A), 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 1,1 -bis(4-hydroxyphenyl)cyclohexane, 1,1 -bis(4-hydroxyphenyl)-3,3,5- trimethylcyclohexane, 4,4'-dihydroxybiphenyl, and dimethylbisphenol A and also the diphenols of formulae (I), (II) and (III).

[0048] These and other suitable dihydroxyaryl compounds are described for example in US 3 028 635 A, US 2 999 825 A, US 3 148 172 A, US 2 991 273 A, US 3 271 367 A, US 4 982 014 A und US 2 999 846 A, in DE 1 570 703 A, DE 2063 050 A, DE 2 036 052 A, DE 2 211 956 A and US 2 999 846 A, in DE 1 570 703 A, DE 2063 050 A, DE 2 036 052 A, DE 2 211 956 A and DE 3 832 396 A, in FR 1 561 518, in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964" and also in JP 62039 / 1986 A, JP 62040 / 1986 A and JP 105550 / 1986 A.

[0049] In the case of homopolycarbonates only one dihydroxyaryl compound is used; in the case of copolycarbonates two or more dihydroxyaryl compounds are used. The dihydroxyaryl compounds employed, similarly to all other chemicals and assistants added to the synthesis, may be contaminated with the contaminants from their own synthesis, handling and storage. However, it is desirable to use raw materials of the highest possible purity.

[0050] Suitable carbonic acid derivatives are for example phosgene and diphenyl carbonate.

[0051] Suitable chain terminators that may be used in the production of polycarbonates are monophenols. Suitable monophenols are for example phenol itself, alkylphenols such as cresols, p-tert-butylphenol, cumylphenol and mixtures thereof.

[0052] Preferred chain terminators are the phenols mono- or polysubstituted by linear or branched - to C30-alkyl radicals, preferably unsubstituted or substituted by tert-butyl. Particularly preferred chain terminators are phenol, cumylphenol and / or p- tert-butylphenol.

[0053] The amount of chain terminator to be employed is preferably 0.1 to 5 mol% based on the moles of diphenols employed in each case. The addition of the chain terminators may be effected before, during or after the reaction with a carbonic acid derivative.

[0054] Suitable branching agents are the trifunctional or more than trifunctional compounds familiar in polycarbonate chemistry, in particular those having three or more than three phenolic OH groups. Suitable branching agents are for example 1 ,3,5-tri(4-hydroxyphenyl)benzene, 1,1,1 -tri(4-hydroxyphenyl)ethane, t ri (4- hydroxyphenyl)phenylmethane, 2,4-bis(4-hydroxyphenylisopropyl)phenol, 2,6-bis(2- hydroxy-5'-methylbenzyl)-4-methylphenol, 2-(4-hydroxyphenyl)-2-(2,4- dihydroxyphenyl)propane, tetra(4-hydroxyphenyl)methane, tetra(4-(4- hydroxyphenylisopropyl)phenoxy)methane and 1,4-bis((4',4"- dihydroxytriphenyl)methyl)benzene and 3,3-bis(3-methyl-4-hydroxyphenyl)-2-oxo-2,3- dihydroindole.The amount of the branching agents for optional employment is pref- erably 0.05 mol% to 2.00 mol%, based on moles of dihydroxyaryl compounds used in each case. The branching agents may be either initially charged together with the dihydroxyaryl compounds and the chain terminators in the aqueous alkaline phase or added dissolved in an organic solvent before the phosgenation. In the case of the transesterification process the branching agents are employed together with the dihydroxyaryl compounds.

[0055] Particularly preferred polycarbonates are the homopolycarbonate based on bisphenol A, the homopolycarbonate based on 1,1 -bis(4-hydroxyphenyl)-3,3,5- trimethylcyclohexane, 4,4'-dihydroxybiphenyl, and the copolycarbonates based on the two monomers bisphenol A and 1,1 -bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and also homo- or copolycarbonates derived from the diphenols of formulae (I), (II) in which R' in each case stands for - to C4-alkyl, aralkyl or aryl, preferably for methyl or phenyl, very particularly preferably for methyl.

[0056] Preferred are also polycarbonates for the production of which dihydroxyaryl compounds of the following formula (1a) have been used:

[0057] (1a), wherein

[0058] R5stands for hydrogen or - to C4-alkyl, - to C4-alkoxy, preferably for hydrogen or methyl or methoxy particularly preferably for hydrogen,

[0059] R6, R7, R8and R9mutually independently stand for C6- to C12-aryl or - to C4- alkyl, preferably phenyl or methyl, in particular for methyl,

[0060] Y stands for a single bond, SO2-, -S-, -CO-, -O-, Q- to C6-alkylene, C2- to C5- alkylidene, C6- to C12-arylene, which can optionally be condensed with further aro- matic rings containing hetero atoms, or for a C5- to C6-cycloalkylidene residue, which can be singly or multiply substituted with - to C4-alkyl, preferably for a single bond, -O-, isopropylidene or for a C5-to C6-cycloalkylidene residue, which can be singly or multiply substituted with - to C4-alkyl,

[0061] V stands for oxygen, C2- to C6-alkylene or C3- to C6-alkylidene, preferably for oxygen or C3- alkylene, p, q and r mutually independently each stand 0 or 1, if q = 0, W is a single bond, if q = 1 and r = 0 is, W stands for -O-, C2- to C6- alkylene or C3- to C6-alkylidene, preferably for -O- or C3-alkylene, if q = 1 and r = 1, W and V mutually independently stand for C2- to C6- alkylene or C3- to C6-alkylidene, preferably for C3alkylene,

[0062] Z stands for - to C6-alkylene, preferably C2-alkylene, o stands for an average number of repeating units from 10 to 500, preferably 10 to 100 and m stands for an average number of repeating units from 1 to 10, preferably 1 to 6, particularly preferably 1.5 to 5.

[0063] It is also possible to use dihydroxyaryl compounds, in which two or more siloxane blocks of general formula (1a) are linked via terephthalic acid and / or isophthalic acid under formation of ester groups.

[0064] Especially preferable are (poly)siloxanes of the formulae (2) and (3) wherein R1stands for hydrogen, - to C4-alkyl, preferably for hydrogen or methyl and especially preferably for hydrogen,

[0065] R2mutually independently stand for aryl or alkyl, preferably for methyl, X stands for a single bond, -SO2-, -CO-, -O-, -S-, - to C6-alkylene, C2- to C5- alkylidene or for C6- to C12-arylene, which can optionally be condensed with further aromatic rings containing hetero atoms,

[0066] X stands for a single bond, -SO2-, -CO-, -O-, -S-, - to C6-alkylene, C2- to C5- alkylidene, C5- to C12-cycloalkylidene or for C6- to C12-arylene, which can optionally be condensed with further aromatic rings containing hetero atoms,

[0067] X preferably stands for a single bond, isopropylidene, C5- to C12- cycloalkylidene or oxygen, and especially preferably stands for isopropylidene, n means an average number from 10 to 400, preferably 10 and 100, especially preferably 15 to 50 and m stands for an average number from 1 to 10, preferably 1 to 6 and especially preferably from 1.5 to 5.

[0068] Also preferably the siloxane block can be derived from one of the following structures: wherein a in formulae (IV), (V) und (VI) means an average number from 10 to 400, preferably from 10 to 100 and especially preferably from 15 to 50.

[0069] It is equally preferable, that at least two of the same or different siloxane blocks of the general formulae (IV), (V) or (VI) are linked via terephthalic acid and / isophthalic acid under formation of ester groups.

[0070] It is also preferable, if p = 0 in formula (1a), V stands for C3-alkylene, if r = 1, Z stands for C2-alkylene, R8and R9stand for methyl, if q = 1, W stands for C3-alkylene, if m = 1, R5stands for hydrogen or Q- to C4-alkyl, preferably for hydrogen or methyl, R6and R7mutually independently stand for Q- to C4-alkyl, preferably methyl, and o stands for 10 to 500.

[0071] Copolycarbonates with monomer units of the general formula (1a), in particular with bisphenol A, and in particular the production of those copolycarbonates are described in WO 2015 / 052106 A2.

[0072] As examples of aromatic polycarbonate suitable for the present invention, mention can be made of those produced from bisphenol A and phosgene, and sold under the trade name Makrolon® 2400, Makrolon® 2600, Makrolon® 2800, Makrolon® 3100 by Covestro Co., Ltd.

[0073] The virgin aromatic polycarbonate is present in the polycarbonate composition according to the present invention in an amount ranging from 1 wt. % to 26 wt. %, preferably from 3 wt. % to 15 wt. %, relative to the total weight of the polycarbonate composition.

[0074] Component B

[0075] The polycarbonate composition according to the present invention comprises a post-consumer recycled (PCR) polycarbonate as component B.

[0076] The post-consumer recycled polycarbonate used in this invention can be obtained from the used parts made of aromatic polycarbonate through a mechanical recycling process which includes the following steps: collection and sorting, shattering, washing, screening, blending, compounding and pelletizing.

[0077] The properties of the suitable post-consumer recycled polycarbonate are as follows:

[0078] The post-consumer recycled polycarbonate is present in the polycarbonate composition according to the present invention in an amount ranging from 60 wt. % to 78 wt. %, preferably from 62 wt. % to 77 wt. %, relative to the total weight of the polycarbonate composition.

[0079] Component C

[0080] The polycarbonate composition according to the present invention comprises a phosphorous-contained flame retardant agent resin as component C.

[0081] In the present invention, organic phosphorus compound is preferably selected from the group consisting of mono- and oligo-phosphates and phosphonates and phosphonate amines, or a mixture of one or more thereof.

[0082] Preferred mono- and oligo-phosphates or phosphonates are phosphorus compounds of the general formula (A) in which

[0083] R1, R2, R3and R4are, independently from one another, individually optionally halogenated CT to C8-alkyl, or C5to C6cycloalkyl, C6to C2o aryl, or C7to C12aralkyl, individually optionally substituted by alkyl, preferably CT to C4-alkyl, and / or by halogen, preferably by chlorine or bromine. Preferably, R1, R2, R3and R4are, independently from each other, CT to C4alkyl, phenyl, naphthyl or phenyl- to C4alkyl. The aromatic radicals R1, R2, R3and R4can in turn have substituents which are substituted by halogen radicals and / or by alkyl, preferably by chlorine, bromine and / or CT to C4alkyl. Particularly preferred aromatic moieties are tolyl, phenyl, xylyl, propylphenyl and butylphenyl, as well as their corresponding brominated and chlorinated derivatives.

[0084] Most preferably, bisphenol A-based oligomeric phosphates according to formula (B) are used as component C: wherein N = 1.0 to 3.0, preferably 1.05 to 2.0, more preferably 1.05 to 1.6, even more preferably 1.0 to 1.2, in particular N = 1.1.

[0085] Phosphorus compounds according to component B are known (cf. e.g., EP 0 363 608 A1, EP 0 640 655 A2) or can be analogously prepared according to the known methods (e.g., Ullmanns Enzyklopadie der technischen Chemie [Ullmann's encyclopaedia of industrial chemistry], vol. 18, p. 301 ff. 1979; Houben-Weyl, Methoden der organischen Chemie [Methods of organic chemistry], vol. 12 / 1, p. 43; Beilstein vol. 6, p. 177).

[0086] It is also possible to use mixtures of phosphates having different chemical structures and / or having the same chemical structure and different molecular weights as component B of the invention.

[0087] It is preferable to use a mixture having the same structure and having different chain lengths, wherein the N value is an average N value. The average N value is determined by calculating the average value of N by determining the composition (molecular weight distribution) of the phosphorus compounds using high-pressure liquid chromatography (HPLC) at 40 °C in a mixture of acetonitrile and water (50:50).

[0088] The component (C) can be used alone or in any desired mixtures with each other or in a mixture with other organic phosphorus compound (s).

[0089] The flame retardant is present in the polycarbonate composition according to the present invention in an amount ranging from 11 wt.% to 21 wt.%, preferably from 13 wt.% to 20 wt.%, relative to the total weight of the polycarbonate composition.

[0090] Component D

[0091] The polycarbonate composition according to the present invention comprises at least one silicone-acrylate rubber based core-shell impact modifier as component D.

[0092] The silicone-acrylate rubber based core-shell impact modifier has a silicone content between 25 wt.% and 50 wt.% based on the silicone-based core-shell impact modifier, also called silicone-acrylate rubber based impact modifier.

[0093] Preferably, the silicone-acrylate rubber based impact modifier comprises,

[0094] D.1) from 10 wt.% to 70 wt.%, of at least one vinyl monomer and

[0095] D.2) from 90 wt.% to 30 wt.%, of one or more silicone-acrylate rubbers as a graft base, the wt.% is calculated based on the weight of the impact modifier.

[0096] The vinyl monomers are used to form polymer chains and these are chemically bonded to the graft substrate D.2.

[0097] Preferably, the vinyl monomer D.1 is selected from vinylaromatics and / or vi- nylaromatics substituted on the nucleus (such as styrene, a-methylstyrene, p- methylstyrene), vinyl cyanides (unsaturated nitriles, such as acrylonitrile and methacrylonitrile), (meth)acrylic acid ( -C8)-alkyl esters, such as methyl methacrylate, ethyl methacrylate, n- butyl acrylate, f- butyl acrylate, and derivatives (such as anhydrides and imides) of unsaturated carboxylic acids, for example maleic anhydride and N- phenyl-maleimide.

[0098] More preferably, the at least one vinyl monomer D.1 comprises (meth)acrylic acid (C-i -C8)-alkyl esters or its combination with styrene, a-methylstyrene or p- methyl styrene.

[0099] Preferably, the graft base D.2 may have a glass transition temperatures of < 10 °C, preferably < 0 °C, particularly preferably < -20 °C. The glass transition temperature was determined by means of dynamic differential calorimetry (DSC) in accordance with the standard DIN EN 61006 at a heating rate of 10 K / min with definition of the Tgas the midpoint temperature (tangent method).

[0100] In some embodiments, monomers D.1 is a mixture of D.1.1) 50 to 99, preferably 60 to 80, especially 70 to 80 parts by weight, based on D.1, of vinylaromatics and / or ring-substituted vinylaromatics (such as styrene, methylstyrene, p-methylstyrene, p-chlorostyrene) and / or (Cl -C8)-alkyl methacrylates, such as methyl methacrylate, ethyl methacrylate, and

[0101] D.1.2) 1 to 50, preferably 20 to 40, especially 20 to 30 parts by weight, based on D.1, of (Cl -C8)-alkyl (meth)acrylates, such as methyl methacrylate, n-butyl acrylate, tert-butyl acrylate, and / or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids, for example maleic anhydride and N-phenylmaleimide.

[0102] Preferred monomers D.1.1 are selected from at least one of the monomers styrene, methylstyrene and methyl methacrylate; preferred monomers D.1.2 are selected from at least one of the monomers maleic anhydride and methyl methacrylate. Particularly preferred monomers are D.1.1 = D.1.2 methyl methacrylate.

[0103] The graft copolymers D are produced by free-radical polymerization, for example by emulsion, suspension, solution or bulk polymerization, preferably by emulsion or bulk polymerization, in particular by emulsion polymerization.

[0104] Since, as is well known, the graft monomers are not necessarily completely grafted onto the graft substrate in the grafting reaction graft copolymers D according to the invention are understood as also including products which are obtained through (co)polymerization of the graft monomers in the presence of the graft substrate and co-obtained during workup. These products may accordingly also comprise free (co)polymer of the graft monomers, i.e. (co)polymer not chemically bonded to the rubber.

[0105] A silicone-acrylate composite rubber or a mixture of different silicone-acrylate composite rubbers is employed as the graft substrate D.2. These silicone-acrylate composite rubbers are preferably composite rubbers having graft-active sites containing:

[0106] D.2.1) from 25 wt.% to 50 wt.%, of silicone rubber proportion, and

[0107] D.2.2) from 75 wt.% to 50 wt.%, of polyalkyl (meth)acrylate rubber proportion, wherein the two rubber components penetrate one another in the composite rubber and are therefore essentially inseparable.

[0108] The particularly preferred proportions of silicone rubber and polyalkyl (meth)acrylate rubber results in a particularly advantageous combination of good mechanical properties, good surface of the component parts and good resistance toward hydrolytic molecular weight degradation and the influence of chemicals. Silicone-acrylate composite rubbers are known and are described for example in US 5,807,914, EP 430134 and US 4888388.

[0109] Suitable silicone rubber components D.2.1 of the silicone-acrylate composite rubbers are silicone rubbers having graft-active sites, the production method therefor is described for example in US 2891920, US 3294725, DE-A 3 631 540, EP 249964, EP 430134 and US 4888388.

[0110] The silicone rubber according to D.2.1 is preferably produced by emulsion polymerization in which siloxane monomer units, crosslinking or branching agents and optionally grafting agents are used.

[0111] Examples of preferably siloxane monomer for production of silicone rubber include dimethylsiloxane or cyclic organosiloxanes having at least 3 ring members, preferably 3 to 6 ring members, for example and with preference hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyltriphenylcyclotrisiloxanes, tetramethyltetraphenylcyclotetrasiloxanes, octaphenylcyclotetrasiloxane.

[0112] The organosiloxane monomers may be used alone or in the form of a mixture comprising 2 or more monomers.

[0113] Preferably crosslinking agents are silane-based crosslinking agents having a functionality of 3 or 4, particularly preferably 4. Preferred examples include: trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane and tetra butoxysilane. The crosslinking agent can be used alone or in a mixture of two or more. Particular preference is given to tetraethoxysilane.

[0114] Examples of grafting agents include [3-methacryloyloxyethyl dimethoxymethylsilane, y-ethacryloyloxypropyl methoxydimethylsilane, y-methacryloyloxypropyl dimethoxymethylsilane, y-methacryloyloxypropyl trimethoxysilane, y- methacryloyloxypropyl ethoxydiethylsilane, y- methacryloyloxypropyl diethoxymethylsilane, S-methacryloyloxybutyl diethoxymethylsilane or mixtures thereof.

[0115] It is preferable to use 0-20 wt.% of grafting agent based on the total weight of the silicone rubber.

[0116] The silicone rubber may be produced by emulsion polymerization as described for example in US 2891920 and US 3294725. Suitable polyalkyl(meth)acrylate rubber components D.2.2 of the silicone- acrylate-composite rubbers may be produced from alkyl methacrylates and / or alkyl acrylates, a crosslinking agent and a grafting agent.

[0117] Examples of preferred alkyl methacrylates and / or alkyl acrylates include the C1 - to C8-alkyl esters, for example methyl, ethyl, n-butyl, t-butyl, n-propyl, n-hexyl, n-octyl, n-lauryl and 2-ethylhexyl esters; haloalkyl esters, preferably halo-C1 -C8-alkyl esters, such as chloroethyl acrylate, and mixtures of these monomers. Particular preference is given to n-butyl acrylate.

[0118] Employable crosslinking agents for the polyalkyl(meth)acrylate rubber component of the silicone-acrylate rubber include monomers having more than one polymerizable double bond. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids having 3 to 8 carbon atoms and unsaturated monohydric alcohols having 3 to 12 carbon atoms or saturated polyols having 2 to 4 OH groups and 2 to 20 carbon atoms, such as ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate and 1,4-butylene glycol dimethacrylate. The crosslinking agents can be used alone or in mixtures of at least two crosslinking agents.

[0119] Examples of preferred grafting agents include allyl methacrylate, triallyl cy- anurate, triallyl isocyanurate or mixtures thereof. Allyl methacrylate may also be used as the crosslinking agent. The grafting agents can be used alone or in mixtures of at least two grafting agents.

[0120] The amount of crosslinking agent and grafting agent is 0.1 wt.% to 20 wt.% based on the total weight of the polyalkyl (meth)acrylate rubber component of the silicone-acrylate rubber.

[0121] The silicone-acrylate-composite rubber is produced by first producing the silicone rubber of D.2.1 in the form of an aqueous latex. This latex is then enriched with the alkyl methacrylates and / or alkyl acrylates to be used, the crosslinking agent and the grafting agent and a polymerization is performed.

[0122] The silicone-acrylate composite graft rubbers are produced by grafting the monomers D.1 onto the rubber substrate D.2. This can be carried out using the polymerization methods described in EP 249964, EP430134 and US 4888388 for example.

[0123] As silicone-acrylate rubber, mention can be made of silicone- -Cs alkyl acrylate rubber. In particle, silicone-butylacrylate rubber can be mentioned as an example. Preferably, the silicone-acrylate rubber based impact modifier is selected from (meth)acrylic acid ( -C8)-alkyl ester-grafted silicone- -Cs alkyl acrylate rubber.

[0124] More preferably, the silicone-acrylate rubber based impact modifier is a methyl methacrylate-grafted silicone-butyl acrylate rubber.

[0125] As an example of commercially available silicone-acrylate rubber based impact modifier can be used in the present invention, mention can be made of Metablen® S-2001, Metablen® S-2030, and Metablen® S2130 from Mitsubishi Rayon Co., Ltd.

[0126] In a preferred embodiment, methyl methacrylate-grafted silicone-butyl acrylate rubber e.g. Metablen® S2130 are used as component D.

[0127] The silicone-acrylate rubber based core-shell impact modifier is present in the polycarbonate composition according to the present invention in an amount ranging from 1 wt.% to 8 wt.%, preferably from 1 wt.% to 7 wt.%, relative to the total weight of the polycarbonate composition.

[0128] Component E

[0129] The polycarbonate composition according to the present invention may comprise one acrylate rubber-based core-shell impact modifier as component E.

[0130] As used herein, acrylate rubber-based core-shell does not include the silicone- acrylate rubber based core-shell impact modifier mentioned above.

[0131] It is preferred that the acrylate rubber-based core-shell impact modifier is selected from acrylate rubber-based impact modifiers grafted with methyl methacrylate.

[0132] As examples of commercial products of acrylate rubber-based core-shell impact modifiers, mention can be made of Paraloid™ EXL2311, EXL2313, EXL2315, EXL2300, EXL2330 and EXL2390 available from Dow Chemicals; and Durastrength® 410, 440 and 480 available from Arkema.

[0133] The acrylate rubber-based core-shell impact modifier is present in the composition according to the present invention in an amount no more than 7 wt.%, preferably from 1 wt.% to 7 wt.%, more preferably from 2 wt.% to 6 wt.%, relative to the total weight of the polycarbonate composition.

[0134] According to the present invention, the content relationship index ( / ) of component C, component D, and component E, having the following formula, is in the range of 0.52-0.68, r= CD*1.2 + CE*0.8) / Cc wherein CDrepresents the content by weight of component D in the composition;

[0135] CErepresents the content by weight of component E in the composition; Ccrepresents the content by weight of component C in the composition. The inventors have found that when the content relationship index ( / ) is out of 0.52-0.68, a good combination of impact strength, flame retardancy, and UV resistance obtained by the composition according to the present invention cannot be achieved.

[0136] Component F

[0137] The polycarbonate composition according to the present invention comprises an UV stabilizer as component F.

[0138] Suitable UV stabilizers are for example, benzotriazoles, triazines, benzophenones and arylated cyanoacrylates. Particularly suitable UV absorbers are hydroxybenzotriazoles such as 2-(3',5'-bis(1,1 -dimethylbenzyl )-2'-hydroxyphenyl) benzotriazole (Tinuvin® 234, BASF SE, Ludwigshafen), 2-(2'-hydroxy-5,-(tert-octyl) phenyl) benzotriazole (Tinuvin® 329, BASF SE, Ludwigshafen), 2-(2'-hydroxy-3,-(2-butyl)-5,-(tert- butyl)phenyl)benzotriazole (Tinuvin® 350, BASF SE, Ludwigshafen), bis(3-(2H- benzotriazolyl)-2-hy-droxy-5-tert-octyl)methane (Tinuvin® 360, BASF SE, Ludwigshafen), 2- (4,6-dipheny1 -1,3,5 -triazin-2 -y1)-5 - (hexyloxy)phenol (Tinuvin® 1577, BASF SE, Ludwigshafen), and also the bnzophenones 2,4-dihydroxybenzophenone (Chi- masorb® 22, BASF SE, Ludwigshafen) and 2-hydroxy-4-(octyloxy)benzophenone (Chi- masorb® 81, BASF SE, Ludwigshafen), 2-propenoic acid, 2-cyano-3,3-biphenyl, 2,2-bis [[(2-cyano -1 -oxo-3,3 -diphenyl -2-propenyl)oxy]methyl]-1,3-propanediyl ester (9CI) (Uvinul® 3030, BASF SE, Ludwigshafen), 242-hydroxy-4-(2-ethylhexyl)oxy]pheny1 -4,6- di(4-phenyl)pheny1 -1,3,5-triazine (Tinuvin® 1600, BASF SE, Ludwigshafen) or tetraethyl 2,2'-(1,4-phenylenedimethylidene)bismalonate (Hostavin® B-Cap, Clariant AG).

[0139] Advantageously, the UV stabilizer is present in the polycarbonate composition according to the present invention in an amount ranging from 0.2 wt.% to 0.8 wt.%, preferably from 0.2 wt.% to 0.4 wt.%, relative to the total weight of the polycarbonate composition.

[0140] Component G The polycarbonate composition according to the present invention comprises an anti-dripping agent as component G.

[0141] Preferably, the anti-dripping agent used is selected from the group consisting of fluorinated polyolefins.

[0142] The fluorinated polyolefins are known (see "Vinyl and Related Polymers" by Schildknecht, John Wiley &Sons, Inc., New York, 1962, pages 484-494; "Fluoropolymers" by Wall, Wiley-lnterscience, John Wiley &Sons, Inc., New York, Volume 13, 1970, pages 623-654; "Modern Plastics Encyclopedia" , 1970-1971, Volume 47, No. 10 A, October 1970, McGraw-Hill, Inc., New York, pages 134 and 774; "Modern Plastics Encyclopaedia" , 1975-1976, October 1975, Volume 52, No. 10 A, McGraw-Hill, Inc., New York, pages 27, 28 and 472 and US-PS 3 671 487, 3 723 373 and 3 838 092) .

[0143] Preferably, the anti-dripping agent is selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroeth- ylene / hexafluoropropylene copolymer and ethylene / tetrafluoroethylene copolymer.

[0144] More preferably, polytetrafluoroethylene (PTFE) is used as anti-dripping agent.

[0145] As an example of commercial products of polytetrafluoroethylene, mention can be made to those sold under the trade name Teflon® by DuPont.

[0146] A master batch of polytetrafluoroethylene and styrene-acrylonitrile (SAN) in a weight ratio of 1 :1, for example, ADS 5000 available from Chemical Innovation Co., Ltd., and POLYB FS-200 available from Han Nanotech Co., Ltd, can also be used.

[0147] The anti-dripping agent is present in the polycarbonate composition according to the present invention in an amount ranging from 0.6 wt.% to 1.0 wt.%, preferably from 0.7 wt.% to 0.9 wt.%, relative to the total weight of the polycarbonate composition.

[0148] Other components

[0149] In addition to components A-G mentioned above, the polycarbonate compositions according to the present invention can optionally comprise one or more additives conventionally used in polycarbonate compositions.

[0150] Preferably, the additive is selected from (i) heat stabilizers and antioxidants such as organic phosphites and phosphonites (for example, STABILIZER 1010); (ii) processing aids; (iii) internal lubricants and external lubricants; (iv) mold release agents (such as, PETS); and (v) colorants. The person skilled in the art can select the type of the additives so as not to adversely affect the desired properties of the polycarbonate composition according to the present invention.

[0151] Advantageously, the total amount of the additives is up to 5 wt. %, preferably up 3 wt. %, relative to the total weight of the polycarbonate composition according to the present invention.

[0152] In some embodiments, the composition of the present invention consists of components A)-G) and optional additive selected from (i) heat stabilizers and antioxidants such as organic phosphites and phosphonites (for example, STABILIZER 1010 and 1076); (ii) processing aids; (iii) internal lubricants and external lubricants; (iv) mold release agents (such as, PETS); and (v) colorants.

[0153] In some embodiments, the polycarbonate composition according to the present invention comprises, relative to the total weight of the composition,

[0154] A) from 3 wt. % to 15 wt. % of aromatic bisphenol A-based polycarbonate,

[0155] B) from 62 wt.% to 77 wt.% of post-consumer recycled (PCR) polycarbonate ,

[0156] C) from 13 wt.% to 20 wt.% of bisphenol A-based oligomeric phosphate according to formula (B): wherein N = 1.0 to 1.2,

[0157] D) from 1 wt.% to 7 wt.% of methyl methacrylate-grafted silicone-butyl acrylate rubber with a silicone content between 25 wt.% and 50 wt.% based on the methyl methacrylate-grafted silicone-butyl acrylate rubber,

[0158] E) no more than 7 wt.% of acrylate rubber-based impact modifiers grafted with methyl methacrylate,

[0159] F) from 0.2 wt.% to 0.4 wt.% of UV additive, and

[0160] G) from 0.6 wt.% to 1.0 wt.% of polytetrafluoroethylene, the content relationship index r is in the range of 0.52-0.68. Preparation of the polycarbonate composition

[0161] The polycarbonate composition according to the present invention can be in the form of, for example, pellets.

[0162] The polycarbonate composition according to the present invention demonstrates a good processing behaviour and can be prepared by a variety of methods. For example, the materials contained in the composition of the present invention are fed into the throat of a twin-screw extruder via a hopper. Alternatively, at least one of the components can be incorporated into the composition by feeding it directly into the extruder at the throat and / or downstream through a side stuffer. Additives can also be compounded into a masterbatch with a desired polymeric resin and fed into the extruder. The extruder is generally operated at a temperature higher than that necessary to cause the composition to flow. The extrudate is immediately quenched in a water bath and pelletized. The pellets can be one-fourth inch long or less as desired. Such pellets can be used for subsequent molding, shaping or forming.

[0163] Melt blending methods are preferred due to the availability of melt blending equipment in commercial polymer processing facilities.

[0164] Illustrative examples of equipment used in such melt processing methods include co-rotating and counter-rotating extruders, single screw extruders, co-kneaders, and various other types of extrusion equipment.

[0165] The temperature of the melt in the processing is preferably minimized in order to avoid excessive degradation of the polymers. It is often desirable to maintain the melt temperature between 230 °C and 300 °C in the molten resin composition, although higher temperatures can be used provided that the residence time of the resin in the processing equipment is kept short.

[0166] In some cases, the melting composition exits from a processing equipment such as an extruder through small exit holes in a die. The resulting strands of the molten resin are cooled by passing the strands through a water bath. The cooled strands can be chopped into small pellets or other suitable shapes for packaging and further handling.

[0167] Shaped articles

[0168] The polycarbonate compositions according to the present invention can be used, for example for the production of various types of shaped articles.

[0169] In the second aspect, the present invention also provides a shaped article made from a polycarbonate composition according to the first aspect of the present invention.

[0170] The polycarbonate composition according to the present invention can be molded into shaped articles such as, housings for electronic device, etc.

[0171] The shaped article made from the polycarbonate composition according to the present invention has a good combination of impact strength, flame retardancy, and UV resistance.

[0172] Preparation of shaped articles

[0173] The polycarbonate compositions according to the present invention can be processed into shaped articles by a variety of means such as injection moulding, extrusion moulding, blow moulding or thermoforming to form shaped articles.

[0174] In the third aspect, the present invention provides a process for preparing the shaped article made from a composition according to the first aspect of the present invention, comprising injection moulding, extrusion moulding, blow moulding or thermoforming the polycarbonate composition according to the present invention.

[0175] During preparing shaped articles with the thermoplastic resin composition according to this invention, the melting temperature for the molding process preferably is in the range of 250-300°C, more preferably 255-290°C, even more preferably 260- 280°C. The mold temperature could be in the range of 40-110 °C, preferably 50-90 °C, and the injection pressure can be in the range of 300-2500 bar, and preferably 500- 2000 bar.

[0176] Examples

[0177] The present invention will be illustrated in detail below with reference to the examples below. The examples are only for the purpose of illustration, rather than limiting the scope of the present invention.

[0178] Materials used

[0179] Component A

[0180] PC: available from the company Covestro Polymer (China), a linear polycarbonate based on bisphenol A having a weight average molecular weight (Mw) of 24000 g / mol, as determined by means of Gel Permeation Chromatography (GPC) in methylene chloride at 25 °C using a polycarbonate standard. Component B

[0181] PC-116A: commercially available from the company Ningbo Xurihongyu Technology Co., Ltd, a PCR polycarbonate based on bisphenol A have a MVR is in the range of 12-16 cm3 / 10min at condition of 300 °C and 1.2kg.

[0182] Component C

[0183] BDP: bisphenol-A bis(diphenyl phosphate), available from the company Zhejiang Wansheng Science China.

[0184] Component D

[0185] S-2130: methyl methacrylate-grafted silicone-butylacrylate rubber with a coreshell structure with a silicone content of 30%, available as Metablen® S2130 from Mitsubishi Rayon Co., Ltd.

[0186] Component E

[0187] EXL-2311 : an acrylate rubber based core-shell impact modifier, available as Pa- raloid® EXL-2311 from the company Dow Chemicals.

[0188] Component F

[0189] Tinuvin 329: UV absorber, available as Tinuvin 329 form BASF Company Limited.

[0190] Component G

[0191] ADS 5000: anti-dripping agent, a masterbatch of polytetrafluoroethylene and Styrene-Acrylonitrile (SAN) in a weight ratio of 1 :1, available as ADS 5000 from IRPC Public Company Limited.

[0192] Other components

[0193] MR-01 : a silicone based grafted core-shell impact modifier with a silicone content of 85%, available as Kane Ace MR-01 from Kaneka company.

[0194] ABS: produced by emulsion polymerisation of 42-45 wt. %, based on the ABS polymer, of a mixture of 27 wt. % acrylonitrile and 73 wt. % styrene in the presence of 55-58 wt. %, based on the ABS polymer, of a crosslinked polybutadiene rubber, available as ABS HRG powder P60 from Styrolution.

[0195] PETS: pentaerythritol tetrastearate, a demoulding agent, available from FACI Asia Pacific Pte Ltd. (Singapore).

[0196] B900: an antioxidant, a mixture of 80% of Irgafos® 168 (tris(2,4-ditert- butylphenyl)phosphite) and 20% of Irganox® 1076 (2,6-ditert-butyl-4-(octa- decanoxycarbonylethyl)phenol, available as Irganox® B900 from BASF (China) Company Limited.

[0197] Kronos 2233: TiO2from KRONOS Worldwide Inc.

[0198] Test methods

[0199] The physical properties of specimens in the examples were tested as follows.

[0200] Izod notched impact strength

[0201] Izod notched impact strength was measured on specimens with dimensions of 80 mm x10 mm x4 mm at the temperature of 23°C, 10°C and 0°C according to IS0180 / A:2000 (4 mm, 5.5J).

[0202] Flame retardancy

[0203] Flame retardancy was measured on specimen with 1.0 mm thickness according to UL94:2015.

[0204] LIV resistance

[0205] UV resistance was measured on specimens with dimensions of 80 mm x10 mm x4 mm. The optical parameters were measured before and after UV ageing at 340nm for 240 hours or 336 hours. The exposure conditions are as follows:

[0206] Black panel temperature: 63°C;

[0207] Chamber temperature: 42°C;

[0208] Humidity: 50% RH;

[0209] Irradiance: 0.70W / m2 / nm at 340nm.

[0210] Glass Window Cycle: continuous light (no water spray) for duration of the test.

[0211] Natural Sunlight Cycle: 102 minutes light, 18 minutes light and water spray, repeating the cycle for the duration of test.

[0212] AE is the change of optical parameters after UV aging and indicates the UV resistance of the samples. The smaller of AE means the better the UV resistance of the sample. In the present application, the sample is defined as passing the UV test when AE <1.

[0213] Comparative Examples (CE) 1 -8 and Invention Examples (IE) 1 -2

[0214] The materials listed in Table 1 were compounded on a twin-screw extruder (ZSK-26) (from Coperion, Werner and Pfleiderer) at a speed of rotation of 250 rpm, a throughput of 20 kg / h, and a machine barrel temperature of 250°C-290 °C and granulated.

[0215] The granules were processed into corresponding testing specimens on an injection moulding machine (from Arburg) with a melting temperature of 270-300 °C and a mold temperature of 60-80 °C.

[0216] The physical properties (including izod notched impact strength, flame retard- ancy, UV resistance) of the compositions obtained were tested and the results were summarized in Table 1.

[0217] Table 1

[0218] It can be seen from Table 1 that comparative composition of comparative example 1 not comprising PCR polycarbonate and silicone-based core-shell impact modifier did not pass the UV resistance test.

[0219] Composition of comparative example 2 not comprising silicone-based core-shell impact modifier did not pass the UV resistance test, and showed a flame-retardancy of V1 at 1.0 mm and brittle impact behavior at 0 °C.

[0220] Compositions of comparative examples 3-6 not comprising silicone-based coreshell impact modifier showed brittle impact behavior at 0 °C.

[0221] Composition of comparative example 7 comprising 9 wt.% of acrylate rubber based core-shell impact modifier showed a flame-retardancy of V1 at 1.0 mm and brittle impact behavior at 0 °C.

[0222] Composition of comparative example 8 using a neat polycarbonate rather than PCR polycarbonate also can pass the UV resistance test, and show impact strength of no less than 28 kJ / m2, flame level of VO at a thickness of 1.0 mm, and good UV resistance.

[0223] Compositions of invention examples 1 and 2 can pass the UV resistance test, and show impact strength of no less than 28 kJ / m2, flame level of VO at a thickness of 1.0 mm, and good UV resistance.

[0224] It can be seen from the comparison between comparative example 8 and invention example 1 shows that the composition according to the present invention exhibited similar performance as composition comprising neat polycarbonate instead of PCR polycarbonate.

[0225] Comparative Examples (CE) 9-16 and Invention Examples (IE) 3-8

[0226] Similarly, the materials listed in Table 2 were compounded, the properties of the compositions obtained were tested and the results were summarized in Table 2.

[0227] It can be seen from Table 2 that composition of comparative example 9 with r out of 0.52-0.68 showed brittle impact behavior at 0 °C.

[0228] Composition of comparative example 10 with r out of 0.52-0.68 showed a flame-retardancy of V1 at 1.0 mm.

[0229] Compositions of comparative example 11, 12, and 16 with r out of 0.52-0.68 showed brittle impact behavior at 0 °C.

[0230] Composition of comparative example 13 showed brittle impact behavior at 0

[0231] 'C. Composition of comparative example 14 also showed brittle impact behavior at 0 °C and 10 °C.

[0232] Composition of comparative example 15 using a neat polycarbonate rather than PCR polycarbonate also can pass the UV resistance test, and show impact strength of no less than 28 kJ / m2, flame level of VO at a thickness of 1.0 mm, and good UV resistance.

[0233] Compositions of invention examples 3-8 can pass the UV resistance test, and show impact strength of no less than 28 kJ / m2, flame level of VO at a thickness of 1.0 mm, and good UV resistance.

[0234] It can be seen from the comparison between comparative example 15 and invention example 7 shows that the composition according to the present invention exhibited similar performance as composition comprising neat polycarbonate instead of PCR polycarbonate.

[0235] Table 2

[0236] Comparative Examples (CE) 17-27 and Invention Examples (IE) 9-12

[0237] Similarly, the materials listed in Table 3 were compounded, the properties of the compositions obtained were tested and the results were summarized in Table 3.

[0238] It can be seen from Table 3 that composition of comparative example 17, 19, 21 -27 with r out of 0.52-0.68 showed brittle impact behavior at 0 °C.

[0239] Composition of comparative example 18 with r out of 0.52-0.68 and not comprising silicone-based impact modifier showed brittle impact behavior at 10 °C.

[0240] Composition of comparative example 20 with r out of 0.52-0.68 and not comprising UV additive cannot pass the UV test and showed brittle impact behavior at 0 °C.

[0241] Compositions of invention examples 9-12 can pass the UV resistance test, and show impact strength of more than 30 kJ / m2, flame level of V0 at a thickness of 1.0 mm, and good UV resistance.

[0242] Table 3

Claims

Claims1. A polycarbonate composition comprising the following components, relative to the total weight of the composition:A) from 1 wt.% to 26 wt.% of virgin aromatic polycarbonate,B) from 60 wt.% to 78 wt.% of post-consumer recycled (PCR) aromatic polycarbonate,C) from 11 wt.% to 21 wt.% of a flame retardant,D) from 1 wt.% to 8 wt.% of silicone-acrylate rubber based core-shell impact modifier with a silicone content between 25 wt.% and 50 wt.% based on the siliconeacrylate rubber based core-shell impact modifier,E) no more than 7 wt% of acrylate-based core-shell impact modifier different from component D,F) from 0.2 wt.% to 0.8 wt.% of UV additive, andG) from 0.6 wt.% to 1.0 wt.% of anti-dripping agent, the content relationship index (r) of component C, component D, and component E, having the following formula, is in the range of 0.52-0.68, r = (CD*1 .2 + CE*0.8) / Cc, whereinCDrepresents the content by weight of component D in the composition ;CErepresents the content by weight of component E in the composition;Ccrepresents the content by weight of component C in the composition.

2. The polycarbonate composition according to claim 1, wherein the aromatic polycarbonate is present in an amount ranging from 3 wt. % to 15 wt. %, relative to the total weight of the polycarbonate composition.

3. The polycarbonate composition according to claim 1 or 2, wherein the post-consumer recycled polycarbonate is present in an amount ranging from 62 wt. % to 77 wt. %, relative to the total weight of the polycarbonate composition.

4. The polycarbonate composition according to any of claims 1 -3, wherein the flame retardant is selected from bisphenol A-based oligomeric phosphates according to formula (B):wherein N = 1.0 to 3.0, preferably 1.05 to 2.0, more preferably 1.05 to 1.6, even more preferably 1.0 to 1.2.

5. The polycarbonate composition according to any of claims 1 -4, wherein the flame retardant is present an amount ranging from 11 wt.% to 21 wt.%, preferably 13 wt.%-20 wt.%, relative to the total weight of the polycarbonate composition.

6. The polycarbonate composition according to any of claims 1 -5, wherein the silicone-acrylate rubber based impact modifier comprises,D.1) from 10 wt.% to 70 wt.%, of at least one vinyl monomer onD.2) from 90 wt.% to 30 wt.%, of one or more silicone-acrylate rubbers as a graft base, the wt.% is calculated based on the weight of the impact modifier.

7. The polycarbonate composition according to claim 6, wherein the silicone- acrylate rubber based core-shell impact modifier is a methyl methacrylate-grafted sili- cone-butyl acrylate rubber.

8. The polycarbonate composition according to any of claims 1 -7, wherein the silicone-acrylate rubber based core-shell impact modifier is present in an amount ranging from 1 wt.% to 7 wt.%, relative to the total weight of the polycarbonate composition.

9. The polycarbonate composition according to any of claims 1 -8, wherein the acrylate rubber-based core-shell impact modifier is selected from acrylate rubberbased impact modifiers grafted with methyl methacrylate.

10. The polycarbonate composition according to any of claims 1 -9, wherein the acrylate rubber-based core-shell impact modifier is present in an amount ranging from 1 wt.% to 7 wt.%, preferably from 2 wt.% to 6 wt.%, relative to the total weight of the polycarbonate composition.

11. The polycarbonate composition according to any of claims 1 -9, wherein the anti-dripping agent is selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride,tetrafluoroethylene / hexafluoropropylene copolymer and ethylene / tetrafluoroethylene copolymer.

12. The polycarbonate composition according to any of claims 1 -11, comprising one or more additives selected from (i) heat stabilizers and antioxidants; (ii) processing aids; (iii) internal lubricants and external lubricants; (iv) mold release; and (v) colorants.

13. The polycarbonate composition according to claim 11, wherein the total amount of the additives is up to 5 wt. %, preferably up 3 wt. %, relative to the total weight of the polycarbonate composition.

14. The polycarbonate composition according to claim 1, comprising, relative to the total weight of the composition,A) from 3 wt. % to 15 wt. % of aromatic bisphenol A-based polycarbonate,B) from 62 wt.% to 77 wt.% of post-consumer recycled (PCR) aromatic polycarbonate,C) from 13 wt.% to 20 wt.% of bisphenol A-based oligomeric phosphate according to formula (B):wherein N = 1.0 to 1.2,D) from 1 wt.% to 7 wt.% of methyl methacrylate-grafted silicone-butyl acrylate rubber with a silicone content between 25 wt.% and 50 wt.% based on the methyl methacrylate-grafted silicone-butyl acrylate rubber,E) no more than 7 wt.% of acrylate rubber-based impact modifiers grafted with methyl methacrylate,F) from 0.2 wt.% to 0.4 wt.% of UV additive, andG) from 0.6 wt.% to 1.0 wt.% of polytetrafluoroethylene, the content relationship index r is in the range of 0.52-0.68.

15. A shaped article made from the composition according to any of claims 1 - 14.

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