WO2020118478A1

WO2020118478A1 - Polycarbonate compositions

Info

Publication number: WO2020118478A1
Application number: PCT/CN2018/119970
Authority: WO
Inventors: Zhenyu Huang; Hao HAN
Original assignee: Covestro Deutschland Ag
Priority date: 2018-12-10
Filing date: 2018-12-10
Publication date: 2020-06-18
Also published as: CN113366061A; CN113366061B

Abstract

The present invention relates to polycarbonate compositions and molded articles with the same. The polycarbonate compositions according to this present invention comprises: A) 25-60 wt.% of a polycarbonate, B) 10-40 wt.% of a polysiloxane-polycarbonate copolymer, C) 20-30 wt.%of glass fibers, D) 1-5 wt.% of a phosphazene compound, E) 1-5 wt.% of an impact modifier, and F) 1-7 wt.% of a mineral filler, wherein all weight percentages unless otherwise indicated are based on the total weight of the polycarbonate composition. The polycarbonate compositions provided in this present invention reach good balanced strict application requirements of good impact performance, high flame retardance and high stiffness and could be used for many applications with strict application requirements, in particularly in the application of producing the luggage support racks used in high speed trains.

Description

Polycarbonate Compositions

Technical Field

The present invention relates to polycarbonate compositions that have increased flame retardance while maintains good Vicat performance and high modulus performances. Furthermore the present invention relates to molded articles with the polycarbonate compositions, in particular to luggage support racks in high speed trains.

Background Art

In industries such as electronic devices, electrical equipment and transportation means, there are continuous trends to produce low weight products. Some solutions focus on the replacement of metal with plastics materials. And some other solutions are to use thin wall designs by using panels having thinner cross-sectional thicknesses. In these solutions, thermoplastic materials are usually adopted, such as polycarbonate compositions, for their many desired properties, for example, enhanced impact resistance, high modulus (stiffness) , and ductility at room temperature or below.

In some industry applications, such as housings of mobile communication devices or interior parts of high speed trains, thermoplastic materials must have high flame retardance, heat resistance and stiffness for restricted safety needs. Usually the flame retardance standard of UL94 vertical burning test (V0) is adopted in most electronic and electrical device housing products.

However, in some specific industry applications, like luggage support racks in high speed trains, more restricted flame retardance standards, such as UL94 5VB flame retardance testing, are adopted. Such applications also require high modulus to reduce the risk of warping or breaking, which is also in particular important in the application of luggage support racks in high speed trains.

In the industry field of polycarbonate compositions, routine solutions to reach high modulus are to introduce glass fibers, and routine solutions to reach high flame retardance are to add flame retardants. In general, glass fiber reinforced flame retardant polycarbonate compositions could meet general applications requirements on high heat resistance and good flame retardance.

The introduction of glass fiber into the polycarbonate compositions leads to negative influences on the impact performance, and for maintaining impact performance, certain impact modifiers is correspondingly added. However, to certain extent, the addition of impact modifiers damages flame retardance performance of the polycarbonate compositions. To balance impact performance and flame retardance of the polycarbonate composites is a big challenge to the industry.

US7,994,248 B2 discloses polycarbonate compositions comprising an optional polycarbonate polymer, a polycarbonate-polysiloxane copolymer, a phosphorous-containing flame retardant, and a reinforced agent, and the polycarbonate compositions have an improved combination of properties, particularly Vicat softening temperature and high flame retardance in thin walls. As disclosed, the introduction of polycarbonate-polysiloxane copolymer into the polycarbonate compositions improves its flame retardance performance, and increasing the loading of polycarbonate-polysiloxane copolymer while reducing the content of the flame retardant bis (diphenyl) phosphate (BDP) maintains the same FR performance level.

US9,023,923 B2 discloses a flame retardant composition comprising a polycarbonate composition comprising a polycarbonate composition, glass fibers, and a flame retardant that comprises a phenoxyphosphazene compound, and the polycarbonate compositions comprises a polysiloxane-carbonate copolymer and copolyester carbonate copolymer. In the flame retardant composition, phosphazene compound is used as flame retardant.

The industry needs to have new and alternative polycarbonate compositions having both high level of flame retardance and excellent impact property.

Summary of the Invention

One of the objects of the present invention is to provide polycarbonate compositions, comprising

A) 25-60 wt. %, preferably 30-55 wt. %, more preferably 30-50 wt. %of a polycarbonate,

B) 10-40 wt. %, preferably 15-35 wt. %, more preferably 18-32 wt. % of a polysiloxane-polycarbonate copolymer, the polysiloxane-polycarbonate copolymer comprising 5-12 wt. %, preferably 6-10 wt. %of polysiloxane unit based on the total weight of polysiloxane-polycarbonate copolymer,

C) 20-30 wt. %, preferably 22-28 wt. %, more preferably 24-26 wt. %of glass fibers,

D) 1-5 wt. %, preferably 2-4 wt. %, more preferably 2-3 wt. %of a phosphazene compound,

E) 1-5 wt. %, preferably 1-4 wt. %, more preferably 2-4 wt. %of an impact modifier, and

F) 1-7 wt. %, preferably 2-6 wt. %, more preferably 2-5 wt. %of a mineral filler, wherein all weight percentages unless otherwise indicated are based on the total weight of the polycarbonate compositions.

Another object of this invention is to provide a process for preparing polycarbonate compositions, comprising the step of blending a group of components comprising

Another object of this invention is to provide articles manufactured from the polycarbonate compositions provided by this invention.

This present invention, with the combination of polycarbonate, polysiloxane-polycarbonate copolymer, glass fibers, phosphazene compound, an impact modifier and a mineral filler, optionally other routine components, the polycarbonate compositions reach a good balanced strict application requirements of good impact performance, high flame retardance and high stiffness. The polycarbonate compositions could be used for many applications with strict application requirements, in particularly in the application of producing the luggage support racks used in high speed trains.

Detailed Description of the Invention

This invention provides discloses polycarbonate compositions and the method for preparing the same as well as articles manufactured made from the polycarbonate compositions.

The polycarbonate compositions provided in this invention comprises

Component A: a polycarbonate

In the context of the invention, the term "polycarbonate" is understood to mean both homopolycarbonates and copolycarbonates. These polycarbonates may be linear or branched in the familiar manner. Mixtures of polycarbonates may also be used according to the invention.

The polycarbonates present in the compositions are produced in a known manner from dihydroxyaryl compounds, carbonic acid derivatives, optionally chain terminators and branching agents.

Particulars pertaining to the production of polycarbonates are disclosed in many patent documents spanning about the last 40 years. Reference is made here, for 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. Müller, H. Nouvertné, 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. Müller "Polycarbonate" in Becker/Braun, Kunststoff-Handbuch, Volume 3/1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag Munich, Vienna 1992, pages 117 to 299.

Aromatic polycarbonates are produced for example by reaction of dihydroxyaryl compounds with carbonyl halides, preferably phosgene, and/or with aromatic dicarbonyl dihalides, preferably benzenedicarbonyl dihalides, by the interfacial process, optionally with use of chain terminators and optionally with use of trifunctional or more than trifunctional branching agents. Another possibility is production by way of a melt polymerization process via reaction of dihydroxyaryl compounds with, for example, diphenyl carbonate.

In the case of homopolycarbonates only one dihydroxyaryl compound is employed and in the case of copolycarbonates two or more dihydroxyaryl compounds are employed.

Examples of suitable carbonic acid derivatives include phosgene or diphenyl carbonate.

Suitable chain terminators that may be employed 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.

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.

Polycarbonates can be the homopolycarbonate based on bisphenol A, the homopolycarbonate based on 1, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane 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 dihydroxyaryl compounds of formulae (I) , (II) and (III)

in which R'in each case is C ₁-to C ₄-alkyl, aralkyl or aryl, preferably methyl or phenyl, more preferably methyl.

Preferred polycarbonate is the homopolycarbonate based on bisphenol A.

To achieve incorporation of additives, component A is preferably employed in the form of powders, pellets or mixtures of powders and pellets.

The polycarbonate employed may also be a mixture of different polycarbonates.

In an embodiment the polycarbonate compositions comprise, as component A, a copolycarbonate comprising one or more monomer units of formula (1)

where

R ¹ is hydrogen or C ₁-to C ₄-alkyl radicals, preferably hydrogen,

R ² is C ₁-to C ₄-alkyl radicals, preferably a methyl radical,

n is 0, 1, 2 or 3, preferably 3,

optionally in combination with a further aromatic homo-or copolycarbonate comprising one or more monomer units of general formula (2)

where

R ⁴ is H, linear or branched C ₁-to C ₁₀-alkyl radicals, preferably linear or branched C ₁-to C ₆-alkyl radicals, more preferably linear or branched C ₁-to C ₄-alkyl radicals, most preferably H or a C ₁-alkyl radical (methyl radical) , and

R ⁵ is linear or branched C ₁-to C ₁₀-alkyl radicals, preferably linear or branched C ₁-to C ₆-alkyl radicals, more preferably linear or branched C ₁-to C ₄-alkyl radicals, most preferably a C ₁-alkyl radical (methyl radical) ;

and where the further homo-or copolycarbonate which is optionally additionally present contains no monomer units of formula (1) .

The monomer unit (s) of general formula (1) is/are introduced via one or more corresponding dihydroxyaryl compounds of general formula (1') :

in which

R ¹ is hydrogen or a C ₁-to C ₄-alkyl radical, preferably hydrogen,

R ² is a C ₁-to C ₄-alkyl radical, preferably methyl radical, and

n is 0, 1, 2 or 3, preferably 3.

The dihydroxyaryl compounds of the formula (1') and the employment thereof in homopolycarbonates are disclosed in DE 3918406 for example.

Another possible embodiment is given to 1, 1-bis- (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane (bisphenol TMC) having the formula (1a) :

In addition to one or more monomer units of formula (1) the copolycarbonate may contain one or more monomer unit (s) of formula (3) :

in which

R ⁶ and R ⁷ are independently H, C ₁-to C ₁₈-alkyl-, C ₁-to C ₁₈-alkoxy, halogen such as Cl or Br or respectively optionally substituted aryl or aralkyl, preferably H,

or C ₁-to C ₁₂-alkyl, more preferably H or C ₁-to C ₈-alkyl and most preferably H or methyl, and

Y is a single bond, -SO ₂-, -CO-, -O-, -S-, C ₁-to C ₆-alkylene or C ₂-to C ₅-alkylidene, and also C ₆-to C ₁₂-arylene, which may optionally be fused with further heteroatom-comprising aromatic rings.

The monomer unit (s) of general formula (3) is/are introduced via one or more corresponding dihydroxyaryl compounds of general formula (3a) :

where R ⁶, R ⁷ and Y each have the meaning stated above in connection with formula (3) .

Very particularly preferred dihydroxyaryl compounds of formula (3a) are dihydroxyaryl compounds of general formula (3b) ,

in which R ⁸ is H, linear or branched C ₁-to C ₁₀-alkyl radicals, preferably linear or branched C ₁-to C ₆-alkyl radicals, more preferably linear or branched C ₁-to C ₄-alkyl radicals, most preferably H or a C ₁-alkyl radical (methyl radical) , and

in which R ⁹ is linear or branched C ₁-to C ₁₀-alkyl radicals, preferably linear or branched C ₁-to C ₆-alkyl radicals, more preferably linear or branched C ₁-to C ₄-alkyl radicals, most preferably a C ₁-alkyl radical (methyl radical) .

Dihydroxyaryl compound (3c) in particular is very particularly preferred here.

The dihydroxyaryl compounds of the general formula (3a) may be used either alone or else in admixture with one another. The dihydroxyaryl compounds are known from the literature or producible by literature methods (see for example H.J. Buysch et al., Ullmann's Encyclopedia of Industrial Chemistry, VCH, New York 1991, 5th Ed., Vol. 19, p. 348) .

Copolycarbonates may be present in the form of block or random copolycarbonates. Random copolycarbonates are particularly preferred. The ratio of the frequency of the diphenoxide monomer units in the copolycarbonate is calculated from the molar ratio of the dihydroxyaryl compounds employed.

In addition to one or more monomer units of general formulae (2) the homo-or copolycarbonate which is optionally additionally present may contain one or more monomer units of formula (3) as previously described for the copolycarbonate.

Component B: a polysiloxane-polycarbonate copolymer

The polycarbonate compositions provided in this present invention comprise, as component B) , 10-40 wt. %, preferably 15-35 wt. %, more preferably 18-32 wt. % of a polysiloxane-polycarbonate copolymer, based on the total weight of the polycarbonate compositions, the polysiloxane-polycarbonate copolymer comprising 5-12 wt. %, preferably 6-10 wt. %of polysiloxane unit based on the total weight of polysiloxane-polycarbonate copolymer.

According to the invention, suitable polysiloxane-polycarbonate copolymers are known in the prior art, or can be prepared by processes known in the prior art literature.

Polydiorganosiloxane (also named as "siloxane" or "polysiloxane" in the present text) block of the polysiloxane-polycarbonate copolymer includes polydiorganosiloxane blocks as in formula (4) :

wherein, each R is independently a C _1-13 monovalent organic group. For example, R may be C ₁-C ₁₃ alkyl, C ₁-C ₁₃ alkoxy, a C ₂-C ₁₃ alkenyl group, C ₂-C ₁₃ alkenyloxy, C ₃-C ₆ cycloalkyl, C ₃-C ₆ cycloalkoxy, C ₆-C ₁₄ aryl, C ₆-C ₁₀ aryloxy, C ₇-C ₁₃ arylalkyl, C ₇-C ₁₃ aralkoxy, C ₇-C ₁₃ alkylaryl, or C ₇-C ₁₃ alkylaryloxy. The above groups can be fully or partly halogenated by fluorine, chlorine, bromine or iodine or combinations thereof. The combination of the above R groups can be used in the same copolymers.

The value of E in formula (4) can vary widely depending on factors like the type and the relative content of each component in the polycarbonate compositions of the present invention, and the desired property of the composition, etc. Generally, E has an average value of 2 to 1,000, preferably 3 to 500, more preferably, 5 to 100. In an embodiment, E has an average value of 10 to 75, preferably of 10 to 40, and in still another embodiment, E has an average value of 40 to 60. In the case where E is a relatively low value, e.g., less than 40, it may be desired to use a relatively large amount of a polysiloxane-polycarbonate copolymer. On the contrary, in the case where E is a relatively high value, e.g., larger than 40, a relatively small amount of a polysiloxane-polycarbonate copolymer can be used.

Component B may also be a combination comprising a first polysiloxane-polycarbonate copolymer and a second polysiloxane-polycarbonate copolymer, wherein the average value of E in the first polysiloxane-polycarbonate copolymer is smaller than the average value of E in the second polysiloxane-polycarbonate copolymer.

In an embodiment, polysiloxane blocks are of formula (5) :

wherein, E is as defined above; each R may be identical or different, and is as defined above; and Ar may be identical or different, and is a substituted or unsubstituted C ₆-C ₃₀ arylene group, wherein, the chain is directly connected to an aromatic moiety. Ar group in formula (5) may be derived from a C ₅-C ₃₀ dihydroxyarylene compound.

In another embodiment, polysiloxane blocks are of formula (6) :

wherein, R and E-1 are as defined above, and each R ⁵ is independently a divalent C ₁-C ₃₀ organic group, and wherein, the polymerized polysiloxane block is the reaction residue of the corresponding dihydroxy compound. In a specific embodiment, polysiloxane blocks are of formula (7) :

wherein, R and E-1 are as defined above. R ⁶ in formula (7) is a divalent C ₂-C ₈ aliphatic group. Each M in formula (7) can be identical or different, and can be halogen, amino, nitro, C ₁-C ₈ alkylthio, C ₁-C ₈ alkyl, C ₁-C ₈ alkoxy, C ₂-C ₈ alkenyl, C ₂-C ₈ alkenyloxy group, C ₃-C ₈ cycloalkyl, C ₃-C ₈ cycloalkoxy, C ₆-C ₁₀ aryl, C ₆-C ₁₀ aryloxy, C ₇-C ₁₂ arylalkyl, C ₇-C ₁₂ aralkoxy, C ₇-C ₁₂ alkylaryl, or C ₇-C ₁₂ alkylaryloxy, wherein, each n is independently 0, 1, 2, 3 or 4.

In an embodiment, M is bromine or chlorine, an alkyl group such as methyl, ethyl or propyl, an alkoxyl group such as methoxyl, ethoxyl, or propoxyl, or an aryl group such phenyl, chlorophenyl or tolyl; R ⁶ is a dimethylene, trimethylene or tetramethylene group; and R is C _1-8 alkyl, haloalkyl such as trifluoropropyl, cyanoalkyl, or aryl such as phenyl, chlorophenyl or tolyl. In another embodiment, R is methyl, or a combination of methyl and trifluoropropyl, or a combination of methyl and phenyl. In a further embodiment, M is methoxyl, n is 1, R ⁶ is a divalent C ₁-C ₃ aliphatic group, and R is methyl.

Specific polydiorganosiloxane blocks are of the following formula (8) , (9) , (10) :

or a combination comprising at least one of the above, wherein, E-1 has an average value of 2-200, 2-125, 5-125, 5-100, 5-50, or 5-20.

In an embodiment, blocks of formula (4) can be derived from the corresponding dihydroxy polysiloxane (11) :

wherein, R, E-1, M, R ⁶ and n are as described above. Such dihydroxy polysiloxane can be prepared by effecting a platinum-catalyzed addition in a siloxane hydride of formula (12) :

wherein, R and E-1 are as defined above, being an aliphatic unsaturated monohydric phenol. Exemplary aliphatic unsaturated monohydric phenols include eugenol, 2-alkylphenol, 4-allyl-2-methylphenol, 4-allyl-2-phenylphenol, 4-allyl-2-bromophenol, 4-allyl-2-tert-butoxyphenol, 4-phenyl-2-phenylphenol, 2-methyl-4-propylphenol, 2-allyl-4, 6-dimethylphenol, 2-allyl-4-bromo-6-methylphenol, 2-allyl-6-methoxy-4-methylphenol, and 2-allyl-4, 6-dimethylphenol. A combination comprising at least one of the above may also be used.

In a preferred embodiment the siloxane blocks of the polysiloxane-polycarbonate copolymer can be derived from the corresponding dihydroxy polysiloxane (I) :

wherein, in this formula (I) ,

R1, independently represents hydrogen atom, halogen atom, hydroxy group, alkyl group having 1 to 20 carbon atoms, alkoxy group or aryl group, preferably a hydrogen atom;

R2 independently represents hydrocarbon group having 1 to 13 carbon atoms or hydroxy group, preferably a methyl group;

R3 independently represents alkylene group having 2 to 8 carbon atoms, preferably 3 carbon atoms;

m independently represents an integer of 0 to 4, preferably 0;

n independently represents an integer of 1 to 200, preferably the values of E as given above;

A represents a structure of the following chemical formula (II) :

X represents polynuclear arylene group which has 6 to 30 carbon atoms and is unsubstituted or substituted with halogen atom, alkyl group, alkoxy group, aryl group or carboxy group, preferably an unsubstituted arylene group.

The most preferred polydiorganosiloxane in this invention is polydimethylsiloxane.

The polysiloxane-polycarbonate copolymer may comprise 50 wt. %to 99 wt. %of carbonate units and 1-50 wt. %of siloxane units. Within this range, the polysiloxane-polycarbonate copolymer may comprise preferably 70-98 wt. %, more preferably 75-97 wt. %of carbonate units and preferably 2-30 wt. %, more preferably 3-25 wt. %, still more preferably 5 to 12 wt. %and most preferably 6 to 10 wt. %of siloxane units. In an exemplary embodiment, the polysiloxane-polycarbonate copolymer is end capped with p-cumylphenol.

In an embodiment, an exemplary polysiloxane-polycarbonate copolymer is a block copolymer having the structure as shown in the following formula (13) :

wherein, the polysiloxane blocks are end capped with eugenol, wherein, x is 1-100, preferably 5-85, more preferably 10-70, particularly preferably 15-65, and more preferably 40-60. In an embodiment, y is 1-90, and z is 1-600. The polysiloxane block can be distributed randomly or distributed in control among the polycarbonate blocks. In an embodiment, x is 30-50, y is 10-30, and z is 450-600.

In an embodiment, the polysiloxane-polycarbonate copolymer comprises 4-12 wt. %, preferably 5-12 wt. %, more preferably 6-10 wt. %of polysiloxane unit, based on the total weight of the polysiloxane-polycarbonate copolymer. Polysiloxane-polycarbonate copolymers comprising 10 wt. %or less of polysiloxane unit are generally optically transparent based on the total weight of the polysiloxane-polycarbonate copolymer.

The polysiloxane-polycarbonate copolymer can have a weight average molecular weight of 2,000-100,000 Dalton, specifically, 5,000 to 50,000 Dalton measured by gel permeation chromatography using cross-linked styrene-divinyl benzene column at a sample concentration of, e.g., 1 mg/ml, and calibrating with polycarbonate standard.

The polysiloxane-polycarbonate copolymer can have a melt volume flow rate of 1-50 cm ³/10 min, preferably 2-30 cm ³ /10 min measured at 300 ℃/1.2 kg. A mixture of polysiloxane-polycarbonate copolymers having different flow features may be used for obtaining an overall desired flow feature.

Component C: glass fibers

The polycarbonate compositions provided in this present invention comprise, as component C) , 20-30 wt. %, preferably 22-28 wt. %, more preferably 24-26 wt. %of glass fibers, based on the total weight of the polycarbonate compositions.

The glass fibers may be flat or round fibers. Flat glass fibers have an elliptical cross-sectional area, while round fibers have a circular cross-sectional area, where the cross-sectional areas are measured perpendicular to the longitudinal axis of the fiber.

The glass fibers may be manufactured from “E-glass” , “A-glass” , “C-glass” , “D-glass” , “R-glass” , or “6-glass” as well as E-glass derivatives that are fluorine-free and/or boron-free. The preferred glass fibers are preferably manufactured from E-glass.

The glass fibers may be woven or nonwoven.

The glass fibers can have a diameter of about 3 micrometers to about 25 micrometers, specifically about 4 micrometers to about 20 micrometers, and more specifically about 8 micrometers to about 15 micrometers.

Component D) : a phosphazene compound

The polycarbonate composition provided in this present invention comprises, as component D) , 1-5 wt. %, preferably 2-4 wt. %, more preferably 2-3 wt. %of a phosphazene compound, based on the total weight of the polycarbonate compositions.

Component D) can be a cyclic phosphazene of formula (III )

wherein,

k represents 1 or an integer from 1 to 10, preferably an integer from 1 to 8, particularly preferably from 1 to 5, having a trimer content (k=1) of from 60 to 98 mol%, based on component D, and wherein

R is in each case identical or different and represents an amine group; C ₁-to C ₈-alkyl, preferably methyl, ethyl, propyl or butyl, each optionally halogenated, preferably halogenated with fluorine; C ₁-to C ₈-alkoxy, preferably methoxy, ethoxy, propoxy or butoxy; C ₅-to C ₆- cycloalkyl, each optionally substituted by alkyl, preferably C ₁-C ₄-alkyl, and/or by halogen, preferably chlorine and/or bromine; C ₆-to C ₂₀-aryloxy, preferably phenoxy, naphthoxy, each optionally substituted by alkyl, preferably C ₁-C ₄-alkyl, and/or by halogen, preferably chlorine, bromine, and/or by hydroxy; C ₇-to C ₁₂-aralkyl, preferably phenyl-C ₁-C ₄-alkyl, each optionally substituted by alkyl, preferably C ₁-C ₄-alkyl, and/or by halogen, preferably chlorine and/or bromine; or a halogen group, preferably chlorine; or an OH group.

Said cyclic phosphazene is preferably:

propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene, aminophosphazene and fluoroalkylphosphazenes, as well as phosphazenes having the following structures:

In the compounds shown above, k = 1, 2 or 3.

Preference is given to phenoxyphosphazene (all R = phenoxy) having a content of oligomers with k = 1 (C1) of from 60 to 98 mol%.

In the case where the phosphazene according to formula (III) is halo-substituted on the phosphorus, for example from incompletely reacted starting material, the content of this phosphazene halo-substituted on the phosphorus is preferably less than 1,000 ppm, more preferably less than 500 ppm.

The phosphazenes can be used alone or in the form of a mixture, that is to say the group R can be identical, or two or more groups in formula (III) can be different. The groups R of a phosphazene are preferably identical.

In a further preferred embodiment, only phosphazenes with identical R are used.

Preferably, where the content of any trimer (k=1) , tetramer (k=2) , oligophosphazene (k = 3, 4, 5, 6 and/or 7 and/or) and /or phosphazene oligomers with k ≥ 8 is indicated in mol-%according to the present invention, this mol-%is based on the cyclic phosphazene of formula (III) .

In a preferred embodiment, the content of tetramers (k=2) (C2) is from 2 to 50 mol%, based on component D, more preferably from 5 to 40 mol%, yet more preferably from 10 to 30 mol%, particularly preferably from 10 to 20 mol%.

In a preferred embodiment, the content of higher oligophosphazenes (k = 3, 4, 5, 6 and 7) (C3) is from 0 to 30 mol%, based on component D, more preferably from 2.5 to 25 mol%, yet more preferably from 5 to 20 mol%and particularly preferably from 6 to 15 mol%.

In a preferred embodiment, the content of oligomers with k ≥ 8 (C4) is from 0 to 2.0 mol%, based on component D, and preferably from 0.10 to 1.00 mol%.

In a further preferred embodiment, the phosphazenes of component D fulfil all three conditions mentioned above as regards the contents (C2-C4) .

Component D preferably comprises, more preferably is a phenoxyphosphazene with a trimer content (k=1) of from 65 to 85 mol%, a tetramer content (k=2) of from 10 to 20 mol%, a content of higher oligophosphazenes (k = 3, 4, 5, 6 and 7) of from 5 to 20 mol%and of phosphazene oligomers with k ≥ 8 of from 0 to 2 mol%, based on component D.

Component D particularly preferably comprises, more preferably is a phenoxyphosphazene with a trimer content (k=1) of from 70 to 85 mol%, a tetramer content (k=2) of from 10 to 20 mol%, a content of higher oligophosphazenes (k = 3, 4, 5, 6 and 7) of from 6 to 15 mol%and of phosphazene oligomers with k ≥ 8 of from 0.1 to 1 mol%, based on component D.

In a further particularly preferred embodiment, component D comprises, preferably is a phenoxyphosphazene with a trimer content (k=1) of from 65 to 85 mol%, a tetramer content (k=2) of from 10 to 20 mol%, a content of higher oligophosphazenes (k = 3, 4, 5, 6 and 7) of from 5 to 15 mol%and of phosphazene oligomers with k ≥ 8 of from 0 to 1 mol%, based on component D.

As mentioned above, in these embodiments it is further preferred that the trimer content (k=1) , tetramer content (k=2) , oligophosphazene content (k = 3, 4, 5, 6 and/or 7) and/or content of phosphazene oligomers with k ≥ 8 is based on the cyclic phosphazene of formula (X) .

n defines the weighted arithmetic mean of k according to the following formula:

where x _i is the content of the oligomer k _i, and the sum of all x _i is accordingly 1.

In an alternative embodiment, n is in the range from 1.10 to 1.75, preferably from 1.15 to 1.50, more preferably from 1.20 to 1.45, and particularly preferably from 1.20 to 1.40 (including the limits of the ranges) .

The phosphazenes and their preparation are described, for example, in EP-A 728 811, DE-A 1 961668 and WO 97/40092.

The oligomer compositions of the phosphazenes in the blend samples can also be detected and quantified, after compounding, by means of ³¹P NMR (chemical shift; δ trimer: 6.5 to 10.0 ppm; δ tetramer: -10 to -13.5 ppm; δ higher oligomers: -16.5 to -25.0 ppm) .

Component D) may also include other flame retardants usually used in the industry.

Component E: an impact modifier

The polycarbonate compositions provided in this present invention comprise, as component E) , 1-5 wt. %, preferably 1-4 wt. %, more preferably 2-4 wt. %of an impact modifier, based on the total weight of the polycarbonate compositions.

The impact modifier component E) can be a graft polymer comprising

E.1 from 10 to 50 wt. %, preferably from 20 to 40 wt. % (in each case based on the graft polymer E) of a shell of at least one vinyl monomer and

E.2 from 90 to 50 wt. %, preferably from 80 to 60 wt. % (in each case based on the graft polymer E) of one or more graft bases of silicone-acrylate composite rubber.

The graft copolymers E are generally prepared by radical polymerization, for example by emulsion, suspension, solution or mass polymerization, preferably by emulsion polymerization. The graft chain of the graft copolymers E is made from PMMA, PMMA-styrene copolymer or SAN.

Suitable monomers E. 1 are vinyl monomers such as vinyl aromatic compounds and/or vinyl aromatic compounds substituted on the ring (such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene) , methacrylic acid (C ₁-C ₈) -alkyl esters (such as methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, allyl methacrylate) , acrylic acid (C ₁-C ₈) -alkyl esters (such as methyl acrylate, ethyl acrylate, n-butyl acrylate, tert-butyl acrylate) , organic acids (such as acrylic acid, methacrylic acid) and/or vinyl cyanides (such as acrylonitrile and methacrylonitrile) and/or derivatives (such as anhydrides and imides) of unsaturated carboxylic acids (for example maleic anhydride and N-phenyl-maleimide) . These vinyl monomers can be used on their own or in mixtures of at least two monomers.

Preferred monomers E. 1 are selected from at least one of the monomers styrene, methyl methacrylate, n-butyl acrylate and acrylonitrile. Particular preference is given to the use of methyl methacrylate or a mixture of styrene and acrylonitrile as the monomer E. 1.

The glass transition temperature of the graft base E. 2 is < 10℃, preferably < 0℃, particularly preferably < -20℃. The graft base E. 2 generally has a mean particle size (d ₅₀ value) of from 0.05 to 10 μm, preferably from 0.06 to 5 μm, particularly preferably from 0.1 to 1 μm.

The mean particle size (d ₅₀ value) is the diameter above and below which in each case 50 wt. %of the particles lie. It can be determined by means of ultracentrifuge measurement (W. Scholtan, H. Lange, Kolloid-Z. und Z. Polymere 250 (1972) , 782-796) .

The graft base E. 2) is composite rubbers of silicone rubber and acrylate rubber, these two types of rubber being present, for example, in the form of a physical mixture or the silicone rubber and the acrylate rubber, for example, forming an interpenetrating network as a result of their preparation or, for example, the silicone rubber and the acrylate rubber forming a graft base that has a core-shell structure. Preferred graft bases E. 2) are composite rubbers of from 10 to 70 wt. %, particularly preferably from 20 to 60 wt. %, silicone rubber and from 90 to 30 wt. %, particularly preferably from 80 to 40 wt. %, butyl acrylate rubber (the indicated wt. %is here based in each case on the graft base E. 2) .

The silicone-acrylate rubbers are preferably composite rubbers having graft-active sites, the silicone rubber and the acrylate rubber interpenetrating in the composite rubber so that they cannot substantially be separated from one another.

Silicone-acrylate rubbers are known and described, for example, in US 5,807,914, EP 430134 and US 4888388.

Silicone rubber components of the silicone-acrylate rubber according to E. 2 are preferably prepared by emulsion polymerisation, in which the siloxane monomer structural units, crosslinkers or branching agents (IV) and optionally grafting agents (V) are used.

There are used as the siloxane monomer structural units, for example and preferably, dimethylsiloxane or cyclic organosiloxanes having at least 3 ring members, preferably from 3 to 6 ring members, such as, for example and preferably, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, trimethyl-triphenyl-cyclotrisiloxane, tetramethyl-tetraphenyl-cyclotetrasiloxane, octaphenylcyclotetrasiloxane.

The organosiloxane monomers can be used on their own or in the form of mixtures of 2 or more monomers. The silicone rubber preferably contains not less than 50 wt. %and particularly preferably not less than 60 wt. %organosiloxane, based on the total weight of the silicone rubber component.

As crosslinkers or branching agents (IV) there are preferably used silane-based crosslinkers having a functionality of 3 or 4, particularly preferably 4. Preferred examples which may be mentioned include: trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane and tetrabutoxysilane. The crosslinker can be used on its own or in a mixture of two or more. Tetraethoxysilane is particularly preferred.

The crosslinker is used in an amount in the range from 0.1 to 40 wt. %, based on the total weight of the silicone rubber component. The amount of crosslinker is so chosen that the degree of swelling of the silicone rubber, measured in toluene, is from 3 to 30, preferably from 3 to 25 and particularly preferably from 3 to 15. The degree of swelling is defined as the weight ratio of the amount of toluene absorbed by the silicone rubber when it is saturated with toluene at 25℃ and the amount of silicone rubber in the dry state. The determination of the degree of swelling is described in detail in EP 249964.

Tetrafunctional branching agents are preferred to trifunctional branching agents because the degree of swelling can then more easily be controlled within the above-described limits.

Suitable grafting agents (V) are compounds that are capable of forming structures of the following formulae:

CH ₂=C (R ²) -COO- (CH ₂) _p-SiR ¹ _nO _(3-n) /2 (V-1)

CH ₂=CH-SiR ¹ _nO _(3-n) /2 (V-2) or

HS- (CH ₂) _p-SiR ¹ _nO _(3-n) /2 (V-3) ,

wherein

R ¹ represents C ₁-C ₄-alkyl, preferably methyl, ethyl or propyl, or phenyl,

R ² represents hydrogen or methyl,

n denotes 0, 1 or 2 and

p denotes an integer from 1 to 6.

Acryloyl-or methacryloyl-oxysilanes are particularly suitable for forming the above-mentioned structure (V-1) and have a high grafting efficiency. Effective formation of the graft chains is thereby ensured, and the impact strength of the resulting resin composition is accordingly promoted. Preferred examples which may be mentioned include: β-methacryloyloxy-ethyldimethoxymethyl-silane, γ-methacryloyloxy-propyl-methoxydimethyl-silane, γ-methacryloyloxy-propyldimethoxymethyl-silane, γ-meth-acryloyloxy-propyltrimethoxy-silane, γ-methacryloyloxy-propylethoxydiethyl-silane, γ-methacryloyloxy-propyldiethoxymethyl-silane, δ-methacryloyl-oxy-butyldiethoxy-methyl-silane or mixtures thereof.

Preferably from 0 to 20 wt. %of grafting agent, based on the total weight of the silicone rubber, is used.

The silicone rubber can be prepared by emulsion polymerisation, as described, for example, in US 2891920 and US 3294725. The silicone rubber is thereby obtained in the form of an aqueous latex. To that end, a mixture containing organosiloxane, crosslinker and optionally grafting agent is mixed with water, with shearing, for example by means of a homogeniser, in the presence of an emulsifier based, in a preferred embodiment, on sulfonic acid, such as, for example, alkylbenzenesulfonic acid or alkylsulfonic acid, the mixture polymerising completely to give the silicone rubber latex. An alkylbenzenesulfonic acid is particularly suitable because it acts not only as an emulsifier but also as a polymerisation initiator. In this case, a combination of the sulfonic acid with a metal salt of an alkylbenzenesulfonic acid or with a metal salt of an alkylsulfonic acid is advantageous because the polymer is thereby stabilised during the subsequent graft polymerisation.

After the polymerisation, the reaction is ended by neutralising the reaction mixture by adding an aqueous alkaline solution, for example by adding an aqueous sodium hydroxide, potassium hydroxide or sodium carbonate solution.

Suitable polyalkyl (meth) acrylate rubber components of the silicone-acrylate rubbers according to E. 2 can be prepared from methacrylic acid alkyl esters and/or acrylic acid alkyl esters, a crosslinker and a grafting agent. Examples of preferred methacrylic acid alkyl esters and/or acrylic acid alkyl esters include the C ₁-to C ₈-alkyl esters, for example methyl, ethyl, n-butyl, tert-butyl, n-propyl, n-hexyl, n-octyl, n-lauryl and 2-ethylhexyl esters; haloalkyl esters, preferably halo-C ₁-C ₈-alkyl esters, such as chloroethyl acrylate, and mixtures of these monomers. n-Butyl acrylate is particularly preferred.

As crosslinkers for the polyalkyl (meth) acrylate rubber component of the silicone-acrylate rubber there can be used monomers having more than one polymerizable double bond. Preferred examples of crosslinking monomers are esters of unsaturated monocarboxylic acids having from 3 to 8 carbon atoms and unsaturated monohydric alcohols having from 3 to 12 carbon atoms, or saturated polyols having from 2 to 4 OH groups and from 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 crosslinkers can be used on their own or in mixtures of at least two crosslinkers.

Examples of preferred grafting agents include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate or mixtures thereof. Allyl methacrylate can also be used as crosslinker. The grafting agents can be used on their own or in mixtures of at least two grafting agents.

The amount of crosslinker and grafting agent is from 0.1 to 20 wt. %, based on the total weight of the polyalkyl (meth) acrylate rubber component of the silicone-acrylate rubber.

The silicone-acrylate rubber is prepared by first preparing the silicone rubber according to E. 2.1 in the form of an aqueous latex. The latex is then enriched with the methacrylic acid alkyl esters and/or acrylic acid alkyl esters that are to be used, the crosslinker and the grafting agent and a polymerisation is carried out. Preference is given to an emulsion polymerisation initiated by radicals, for example by a peroxide, an azo or a redox initiator. Particular preference is given to the use of a redox initiator system, especially of a sulfoxylate initiator system prepared by combination of iron sulfate, disodium ethylenediaminetetraacetate, rongalite and hydroperoxide.

The grafting agent that is used in the preparation of the silicone rubber has the effect of bonding the polyalkyl (meth) acrylate rubber component covalently to the silicone rubber component. In the polymerisation, the two rubber components interpenetrate and thus form the composite rubber, which can no longer be separated into its constituents of silicone rubber component and polyalkyl (meth) acrylate rubber component after the polymerisation.

For the preparation of the silicone-acrylate graft polymers E mentioned as component E) , the monomers E. 1 are grafted on to the rubber base E. 2.

The polymerisation methods described, for example, in EP 249964, EP 430134 and US 4888388 can be used thereby.

For example, the graft polymerisation is carried out according to the following polymerisation method: In a single-or multi-stage emulsion polymerisation initiated by radicals, the desired vinyl monomers E. 1 are polymerised on to the graft base, which is present in the form of an aqueous latex. The grafting efficiency should thereby be as high as possible and is preferably greater than or equal to 10%. The grafting efficiency is significantly dependent on the grafting agent that is used. After the polymerization to the silicone (acrylate) graft rubber, the aqueous latex is added to hot water, in which metal salts, such as, for example, calcium chloride or magnesium sulfate, have previously been dissolved. The silicone (acrylate) graft rubber thereby coagulates and can subsequently be separated.

Component E) may be selected from impact modifiers usually used in the industry, and silicone-acrylic rubber or silicone rubber based with grafted shell of methyl methacrylate (MMA) or MMA styrene copolymer are preferred, for example Metablen SX-005 and Metablen S-2030 from Mitsubishi Chemicals.

Component F: mineral fillers

The polycarbonate compositions provided in this present invention comprise, as component F) , 1-7 wt. %, preferably 2-6 wt. %, more preferably 2-5 wt. %of mineral fillers, based on the total weight of the polycarbonate compositions.

The polycarbonate compositions comprise mineral fillers as component F. Examples of mineral fillers are mica, talc, calcium carbonate, dolomite, wollastonite, barium Sulfate, silica, kaolin, feldspar, barytes, or the like, or a combination comprising at least one of the foregoing mineral fillers, and preferably the mineral fillers are selected from the group of kaolin and talc. Kaolin is more preferred as mineral fillers in this invention.

The mineral fillers may have an average particle size (d ₅₀ value) of 0.1 to 20 micrometers, specifically 0.5 to 10 micrometers, and more specifically 1 to 3 micrometers. An exemplary mineral filler is talc having an average particle size (d50 value) of 1 to 3 micrometers. The average particle size (d50 value) of the mineral fillers can be determined by means of ultracentrifuge measurement (W. Scholtan, H. Lange, Kolloid, Z. und Z. Polymere 250 (1972) , 782-l796) .

The mineral filler are present in amounts of 1-7 wt. %, preferably 2-6 wt. %, more preferably 2-5 wt. %, based on the total weight of the polycarbonate composition. An exemplary mineral filler of talc in the present invention is 2-6 wt. %, based on the total weight of the polycarbonate composition. An exemplary mineral filler of kaolin in the present invention is 2-5 wt. %, based on the total weight of the polycarbonate composition.

Further additives

The polycarbonate compositions can comprise further conventional polymer additives, such as flame-retardant synergists, lubricants and demoulding agents (for example pentaerythritol tetrastearate) , nucleating agents, stabilizers (for example UV/light stabilizers, heat stabilizers, antioxidants, transesterification inhibitors, hydrolytic stabilizers) , antistatics (for example conductive blacks, carbon fibres, carbon nanotubes as well as organic antistatics such as polyalkylene ethers, alkyl sulfonates or polyamide-containing polymers) as well as colourants, and pigments.

There are preferably used as stabilizers sterically hindered phenols and phosphites or mixtures thereof, such as, for example,

B900 (Ciba Specialty Chemicals) . Pentaerythritol tetrastearate is preferably used as the demoulding agent. Carbon black is further preferably used as a black pigment (e.g. Blackpearls) .

As well as comprising optional further additives, particularly preferred moulding compositions comprise a demoulding agent, particularly preferably pentaerythritol tetrastearate, in an amount of from 0.1 to 1.5 parts by weight, preferably from 0.2 to 1.0 part by weight, particularly preferably from 0.3 to 0.8 parts by weight. As well as comprising optional further additives, particularly preferred moulding compositions comprise at least one stabilizer, for example selected from the group of the sterically hindered phenols, phosphites and mixtures thereof and particularly preferably

B900, in an amount of from 0.01 to 0.5 part by weight, preferably from 0.03 to 0.4 part by weight, particularly preferably from 0.06 to 0.3 part by weight.

The combination of PTFE, pentaerythritol tetrastearate and Irganox B900 with a phosphorus-based flame retardant is also particularly preferred.

Process for preparing polycarbonate compositions

B) 10-40 wt. %, preferably 15-35 wt. %, more preferably 18-32 wt. %of a polysiloxane-polycarbonate copolymer, the polysiloxane-polycarbonate copolymer comprising 5-12 wt. %, preferably 6-10 wt. %of polysiloxane unit based on the total weight of polysiloxane-polycarbonate copolymer,

C) 20-30 wt. %, preferably 22-28 wt. %of glass fibers,

E) 1-5 wt. %, preferably 1-4 wt. %of an impact modifier, and

F) 1-7 wt. %, preferably 2-6 wt. %of a mineral filler, wherein all weight percentages unless otherwise indicated are based on the total weight of the polycarbonate compositions.

In the process, the components can be blended with following steps:

1) premixing Component D-F or Component D-E to obtain a premix,

2) mixing the premix with Component A-C or Component A-C and F, for example in a twin-screw extruder, and

3) granulating the mixture to obtain granules.

Component F can be added either in step 1) or in step 2) .

Moulded Articles

This present invention also provides articles manufactured from the polycarbonate compositions provided by this invention.

Examples

With reference to the examples below, the present invention will be described in detail. These examples are only for the purpose of illustration, instead of intending to limit the scope of the present invention.

Raw material applied in Examples

*The weight average molecular weights of the polycarbonates used in the examples were measured by GPC (gel permeation chromatography) with polycarbonate standard.

Preparation of molded articles with polycarbonate compositions

The polycarbonate compositions in the comparative Examples and the inventive Examples in the present invention were prepared according to the following process:

1) premixing Component D and Component E, and anti-dropping agent or mold release agent as listed in Table 1-3 for about 2 minutes by a high-speed mixer (Reimelt Henschel mixer, model No. FML40) to obtain a premix;

2) at barrel temperature of 180-300 ℃, mixing the premix with other components, including Component A, Component B, Component C, Component F (amineral filler) as listed in Table 1-3 in a twin-screw extruder (apparatus and model No. Coperion ZSK26) and granulating by extrusion to obtain granules;

3) the granules were molded to the molded articles by an injection moulding machine. Injection moulding machine: Arburg 370S 700-170 S/N 215673

Process parameters: melt temperature 300℃, mold temperature 80℃, injection pressure 1000-2400 bar

In comparative Examples and inventive Examples, unless particularly indicated, the amount in percent of each component refers to the weight percent of the component relative to the resulting polycarbonate composition, with the total weight of polycarbonate compositions as being 100 wt. %.

Test samples corresponding to the resulting polycarbonate composition granules were produced according to the requirements of the test standards in Tables 1-3, and the corresponding tests were carried out according to the corresponding test standards listed in Tables 1-3.

As shown in Table 1, comparative examples C1-C7 comprise no component E (i.e. impact modifiers) and comprise no component F (i.e. mineral filler) . Besides that, comparative examples C1-C3 comprise no component B (i.e. polysiloxane-polycarbonate copolymer) . Comparative example C7 comprises no component D (i.e. FR agent phosphazene) .

As shown in Table 2 comparative examples C8-C11 comprise no component F. Comparative examples C12-C13 comprise no component B and E. Comparative examples C14-C15 comprise no component D. Comparative examples C16 comprises 6%of impact modifier which is more than that required in the present invention. Comparative examples C17 comprises 8%of mineral fillers which is more than that required in the present invention.

As shown in Table 1 and 2, all the performance testing results on molded article samples made with C1-C17 polycarbonate compositions failed to pass the flame retardance testing on 5VB or V0.

In the inventive example E1 as shown in Table 3, the polycarbonate compositions by combining 37.05 wt. %of polycarbonate, 30 wt. %of polysiloxane-polycarbonate copolymer, 25wt. %of glass fibers, 2.5wt. %of phosphazene compound, 2 wt. %of impact modifier, and 3 wt. %of mineral filler, as well as other components of anti-dropping agent and mold release agent, reached the flame-retardant level of both UL94 [email protected] and [email protected] &1.5mm requirements (testing conditions: 23 ℃ and 2 days) . Meanwhile, its flexural modulus reached 6.72×10 ³ MPa (2mm/min, according to ISO178: 2010) and its Izod notched impact strength reached 14 kJ/m ² (23 ℃, 3mm, 5.5J) .

In the inventive example E2, as shown in Table 3, by changing the mineral filler from kaolin in inventive example 1 to talc, the polycarbonate compositions also reached good performances in flame retardance, high modulus and impact performances. Compared to comparative examples C10 and C11, inventive examples E1 and E2 showed the unique effect of mineral fillers on the FR performance. Comparing with comparative examples C14 and C15, inventive examples E1 and E2 exhibited the advantage of FR agent phosphazene over other phosphorus solid FR agents (PX-200 and Sol-DP) on the FR performance.

In inventive examples E3-E5, the contents of polycarbonate, polysiloxane-polycarbonate copolymer, and phosphazene compound were changed within the scope of this invention and all of polycarbonate compositions had shown good performances in flame retardance, high modulus and impact performances.

The above are only preferred examples of the present invention, being not employed to limit the invention. For those skilled in the art, various modifications and variations can be made to the compositions and methods of the present invention without departing from the scope of the invention. With reference to the disclosure in the present description, those skilled in the art may also reach other examples. The present description and examples should be only regarded as illustrative, and the true scope of the present invention is defined by the appended claims and their equivalents.

Claims

Polycarbonate compositions, comprising

A) 25-60wt. %of a polycarbonate,

B) 10-40 wt. %of a polysiloxane-polycarbonate copolymer,

C) 20-30 wt. %of glass fibers,

D) 1-5wt. %of a phosphazene compound,

E) 1-5wt. %of an impact modifier, and

F) 1-7 wt. %of a mineral filler,

wherein all weight percentages unless otherwise indicated are based on the total weight of the polycarbonate compositions.
The polycarbonate compositions as claimed in claim 1, wherein,

A) 30-55 wt. %of a polycarbonate,

B) 15-35wt. %of a polysiloxane-polycarbonate copolymer,

C) 22-28wt. %of glass fibers,

D) 2-4wt. %of a phosphazene compound,

E) 1-4 wt. %of an impact modifier, or

F) 2-6wt. %of a mineral filler.
The polycarbonate compositions as claimed in claim 2, wherein,

A) 30-50 wt. %of a polycarbonate,

B) 18-32 wt. %of a polysiloxane-polycarbonate copolymer,

C) 24-26 wt. %of glass fibers,

D) 2-3wt. %of a phosphazene compound,

E) 2-4 wt. %of an impact modifier, or

F) 2-5wt. %of a mineral filler.
The polycarbonate compositions as claimed in claim 1, wherein, the polysiloxane-polycarbonate copolymer comprising 5-12 wt. %of polysiloxane unit based on the total weight of polysiloxane-polycarbonate copolymer.
The polycarbonate compositions as claimed in claim 1, wherein, the impact modifier is selected from the group of silicone-acrylic rubber, silicone rubber based with grafted shell of methyl methacrylate (MMA) and MMA styrene copolymer.
Polycarbonate compositions having the property of the flame-retardance performance passing UL94 5VB requirements (test conditions: 2.0 mm, 23 ℃, 2 days) , the flexural modulus of more than 6.50×10 ³MPa (2mm/min, according to ISO178: 2010) and the Izod notched impact strength of 14 kJ/m ² (23 ℃, 3mm, 5.5J) .
A process for preparing polycarbonate compositions, comprising the step of blending a group of components comprising

A) 25-60 wt. %a polycarbonate,

B) 10-40 wt. %of a polysiloxane-polycarbonate copolymer, the polysiloxane-polycarbonate copolymer comprising 5-12 wt. %of polysiloxane unit based on the total weight of polysiloxane-polycarbonate copolymer,

C) 20-30 wt. %of glass fibers,

D) 1-5 wt. %of a phosphazene compound,

E) 1-5 wt. %of an impact modifier, and

F) 1-7 wt. %of a mineral filler,

wherein all weight percentages unless otherwise indicated are based on the total weight of the polycarbonate compositions.
The process as claimed in claim 7, wherein,

A) 30-55 wt. %of a polycarbonate,

B) 15-35 wt. %of a polysiloxane-polycarbonate copolymer, the polysiloxane-polycarbonate copolymer comprising 6-10 wt. %of polysiloxane unit based on the total weight of polysiloxane-polycarbonate copolymer,,

C) 22-28 wt. %of glass fibers,

D) 2-4 wt. %of a phosphazene compound,

E) 1-4 wt. %of an impact modifier, or

F) 2-6 wt. %of a mineral filler.
The process as claimed in claim 8, wherein,

A) 30-50 wt. %of a polycarbonate,

B) 18-32 wt. %of a polysiloxane-polycarbonate copolymer,

C) 24-26 wt. %of glass fibers,

D) 2-3wt. %of a phosphazene compound,

E) 2-4 wt. %of an impact modifier, or

F) 2-5 wt. %of a mineral filler.
A molded article made with the polycarbonate compositions as claimed as in claim 1-6.
The molded article as claimed in claim 10, the molded article is a luggage support rack.
A luggage support rack made with the polycarbonate compositions as claimed as in claim 1-6.
The use of the luggage support rack as claimed in claim 11 in a train.
A transportation means with a molded article made with the polycarbonate compositions as claimed in claim 1-6.
The transportation means as claimed in claim 14, the transportation means is a high speed train.