Patent Description:
Polycarbonate/ABS (Acrylonitrile-Butadiene-Styrene) alloy is widely used for a lot of applications, especially for automotive interior, due to its excellent property combination of lower emission, excellent mold-processing ability, good economic efficiency and strong physical properties such as high impact strength, high heat resistance, good aesthetic and so on.

However, there has been recently a growing appeal from end users in automotive market for low-odor materials to be used in manufacture of automotive interiors. In that case, PC/ABS blends, though generally believed to make less impact on odor of automotive interior than other types of materials including adhesives and leathers, was often requested to improve its odor performance from the perspective of odor control of the whole vehicle system. For this purpose, great efforts since then have been made by doing multiple degassing compounding or emission regulation of the raw materials (PC and ABS and so on) or PC/ABS recipe optimization or their combinations. However, a big gap is still there between the market demand and industry offers. For instance, typical PC/ABS materials generally shows an odor rank of <NUM>-<NUM> as evaluated according to PV3900:<NUM> after being conditioned at <NUM> for <NUM> hours, while the rank point of <NUM> is desired by the automotive interior market. The cause of bad odor with PC/ABS materials can be traced to the presence of polybutadiene-based rubbers in polymer matrix, which inherently have poor thermal instability and will produce odorous volatile/gas in thermal processing and thus worse odor of the finished materials.

On the other hand, aromatic polyesters (such as PET, PBT, PTT, PETG and PCTG etc.) have been widely considered as potential blending materials with polycarbonate.

<CIT>, <CIT>, <CIT>, <CIT>, and <CIT> which describe compositions based on PC/aromatic polyester blends either focus on improved flame retardance or on mechanical properties or on chemical resistance or a combination of these features for the finished materials. However, the odor assessment of such PC blends with all kinds of aromatic or aliphatic polyesters had scarcely been mentioned. <CIT> discloses chemically resistant polycarbonate-polyester compositions used as filler, antioxidant, thermal stabilizer, quencher and colorant, comprises polycarbonate, poly(<NUM> ,<NUM>-cyclohexanedimethylene terephthalate) and poly(carbonate-siloxane).

There is a continuous need for new compositions to offer desirable odor performance/rank (e.g. <NUM> according to PV3900:<NUM> after being conditioned at <NUM> for <NUM> hours) for automotive interior materials, while properties such as good flowability, high impact strength, and high heat resistance are also present.

Thus, one object of the present invention is to provide a thermoplastic polycarbonate composition which has a combination of low odor rank, good impact performance, good flowability, and good heat resistance.

Therefore, an object of the present invention is a thermoplastic polycarbonate composition comprising the following components, relative to the total weight of the composition:.

Another object of the present invention is a shaped article made from the polycarbonate composition according to the first aspect of the present invention.

Still Another object of the present invention is a process for preparing the shaped article according to the second aspect of the present invention, comprising injection moulding, extrusion moulding, blowing moulding or thermoforming the polycarbonate composition according to the first aspect of the present invention.

Still another object of the present invention is a use of an amorphous copolyester comprising <NUM>,<NUM>-cyclohexanedimethylene terephthalate repeating unit having the structure
<CHM>
and <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-cyclobutylene terephthalate repeating unit having the structure
<CHM>.

The polycarbonate composition and the shaped article according to the present invention demonstrate an odor rank of <NUM> as measured according to PV3900: <NUM> after being conditioned at <NUM> for <NUM> hours, an impact strength of higher than <NUM> KJ/m<NUM> at -<NUM> as measured according to ISO <NUM>/A: <NUM> and a Vicat temperature of higher then <NUM> as measured according to ISO <NUM>: <NUM>. The polycarbonate composition according to the present invention also has good flowability, as demonstrated by the melt volume rate determined according to ISO <NUM>-<NUM>: <NUM> at a temperature of <NUM> with a plunger load of <NUM>.

The polycarbonate compositions and the shaped articles according to the present invention are suitable for interior applications which require relatively low odor rank (not more than <NUM>, as measured according to PV3900: <NUM> after being conditioned at <NUM> for <NUM> hours), excellent impact strength, and good heat resistance, such as automotive interior applications etc..

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.

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 "from.

As used herein, the expression "comprising" is to be interpreted as encompassing all specifically mentioned features as well optional, additional, unspecified ones.

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.

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".

Technical features described for each element in the present application can combined in any way on the provision that there is no conflict. Preferred, particularly preferred embodiments described for the composition according to the invention apply as well for a shaped articled made from the composition according to the invention or the process or the claimed use.

The polycarbonate composition according to the present invention comprises an aromatic polycarbonate as component A.

In the present application, references to "polycarbonate" do not include polysiloxane-polycarbonate copolymers.

According to the invention, "polycarbonate" 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.

A portion, preferably up to <NUM> mol%, more preferably of <NUM> mol% to <NUM> mol%, of the carbonate groups in the polycarbonates used in accordance with the invention may have been replaced by aromatic dicarboxylic ester groups. Polycarbonates of this type that incorporate not only acid radicals derived from carbonic acid but also acid radicals derived from aromatic dicarboxylic acids in the molecular chain are referred to as aromatic polyester carbonates. For the purposes of the present invention, they are covered by the umbrella term "thermoplastic aromatic polycarbonates".

Replacement of the carbonate groups by the aromatic dicarboxylic ester groups proceeds essentially stoichiometrically and also quantitatively and the molar ratio of the reaction partners is therefore also reflected in the final polyester carbonate. The aromatic dicarboxylic ester groups can be incorporated either randomly or blockwise.

Aromatic polycarbonates selected in accordance with the invention preferably have weight-average molecular weights Mw of <NUM><NUM> to <NUM><NUM>/mol, more preferably of <NUM><NUM> to <NUM><NUM>/mol, even more preferably of <NUM><NUM> to <NUM><NUM>/mol, most preferably of <NUM><NUM> to <NUM><NUM>/mol. The values for Mw here 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 <NUM>-<NUM>-09D (<NUM> Edition in German) from Currenta GmbH & Co. OHG, Leverkusen. The eluent is dichloromethane. Column combination of crosslinked styrene-divinylbenzene resins. Diameter of analytical columns: <NUM>; length: <NUM>. Particle sizes of column material: <NUM> to <NUM>. Concentration of solutions: <NUM>% by weight. Flow rate: <NUM>/min, temperature of solutions: <NUM>. Detection using a refractive index (RI) detector.

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

With regard to the interfacial process reference is made for example to<NPL>et seq. , to <NPL>, to <NPL> and also to <CIT>.

The melt transesterification process is described, for example, in the "<NPL>), and in patent specifications <CIT> and <CIT>.

Particulars pertaining to the production of polycarbonates are disclosed in many patent documents spanning approximately the last <NUM> years. Reference may be made here by way of example to <NPL>, to <NPL>, and finally to <NPL>.

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 replaced in the aromatic polycarbonates. Preparation via a melt polymerization process by reaction of dihydroxyaryl compounds with, for example, diphenyl carbonate is likewise possible.

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

Preferred dihydroxyaryl compounds are <NUM>,<NUM>'-dihydroxydiphenyl, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane (bisphenol A), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>-methylbutane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-p-diisopropylbenzene, <NUM>,<NUM>-bis(<NUM>-methyl-<NUM>-hydroxyphenyl)propane, dimethylbisphenol A, bis(<NUM>,<NUM>-dimethyl-<NUM>-hydroxyphenyl)methane, <NUM>,<NUM>-bis(<NUM>,<NUM>-dimethyl-<NUM>-hydroxyphenyl)propane, bis(<NUM>,<NUM>-dimethyl-<NUM>-hydroxyphenyl)sulfone, <NUM>,<NUM>-bis(<NUM>,<NUM>-dimethyl-<NUM>-hydroxyphenyl)-<NUM>-methylbutane, <NUM>,<NUM>-bis(<NUM>,<NUM>-dimethyl-<NUM>-hydroxyphenyl)-p-diisopropylbenzene and <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethylcyclohexane and also the bisphenols (I) to (III)
<CHM>
in which R' in each case stands for C<NUM>- to C<NUM>-alkyl, aralkyl or aryl, preferably for methyl or phenyl, very particularly preferably for methyl.

Particularly preferred dihydroxyaryl compounds are <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)propane (bisphenol A), <NUM>,<NUM>-bis(<NUM>,<NUM>-dimethyl-<NUM>-hydroxyphenyl)propane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)cyclohexane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethylcyclohexane, <NUM>,<NUM>'-dihydroxybiphenyl, and dimethylbisphenol A and also the diphenols of formulae (I), (II) and (III).

These and other suitable dihydroxyaryl compounds are described for example in <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> und <CIT>, in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>, in <CIT>, <CIT>, <CIT>, <CIT> and <CIT>, in <CIT>, in the monograph "<NPL>" and also in <CIT>, <CIT> and <CIT>.

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.

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

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.

Preferred chain terminators are the phenols mono- or polysubstituted by linear or branched C<NUM>- to C<NUM>-alkyl radicals, preferably unsubstituted or substituted by tert-butyl. Particularly preferred chain terminators are phenol, cumylphenol and/or p-tert-butylphenol.

The amount of chain terminator to be employed is preferably <NUM> to <NUM> 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.

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 <NUM>,<NUM>,<NUM>-tri(<NUM>-hydroxyphenyl)benzene, <NUM>,<NUM>,<NUM>-tri(<NUM>-hydroxyphenyl)ethane, tri(<NUM>-hydroxyphenyl)phenylmethane, <NUM>,<NUM>-bis(<NUM>-hydroxyphenylisopropyl)phenol, <NUM>,<NUM>-bis(<NUM>-hydroxy-<NUM>'-methylbenzyl)-<NUM>-methylphenol, <NUM>-(<NUM>-hydroxyphenyl)-<NUM>-(<NUM>,<NUM>-dihydroxyphenyl)propane, tetra(<NUM>-hydroxyphenyl)methane, tetra(<NUM>-(<NUM>-hydroxyphenylisopropyl)phenoxy)methane and <NUM>,<NUM>-bis((<NUM>',<NUM>"-dihydroxytriphenyl)methyl)benzene and <NUM>,<NUM>-bis(<NUM>-methyl-<NUM>-hydroxyphenyl)-<NUM>-oxo-<NUM>,<NUM>-dihydroindole. The amount of the branching agents for optional employment is preferably <NUM> mol% to <NUM> 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.

Particularly preferred polycarbonates are the homopolycarbonate based on bisphenol A, the homopolycarbonate based on <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethylcyclohexane, <NUM>,<NUM>'-dihydroxybiphenyl, and the copolycarbonates based on the two monomers bisphenol A and <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethylcyclohexane and also homo- or copolycarbonates derived from the diphenols of formulae (I), (II) and (III)
<CHM>
in which R' in each case stands for C<NUM>- to C<NUM>-alkyl, aralkyl or aryl, preferably for methyl or phenyl, very particularly preferably for methyl.

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® <NUM>, Makrolon® <NUM>, Makrolon® <NUM>, Makrolon® <NUM> by Covestro Co.

The aromatic polycarbonate is present in the polycarbonate composition in an amount ranging from <NUM> wt. % to <NUM> wt. %, relative to the total weight of the polycarbonate composition.

The polycarbonate composition according to the present invention comprises a polysiloxane-polycarbonate block copolymer (also named as "SicoPC" in the context of the present application) as component B.

The polysiloxane-polycarbonate copolymer comprises polydiorganosiloxane (also named as "siloxane" in the context of the present application) blocks and polycarbonate blocks.

The polysiloxane-polycarbonate copolymer can be obtained by using a (poly)siloxane of the following formula (1a) as a dihydroxyaryl compound in the process for preparation an aromatic polycarbonate as mentioned previously with respect to component A:
<CHM>
wherein.

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.

Especially preferable are (poly)siloxanes of the formulae (<NUM>) and (<NUM>)
<CHM>
<CHM>.

Also preferably the siloxane block can be derived from one of the following structures:
<CHM>
<CHM>
preferably (Va)
<CHM>
or
<CHM>
wherein a in formulae (IV), (V) und (VI) means an average number from <NUM> to <NUM>, preferably from <NUM> to <NUM> and especially preferably from <NUM> to <NUM>.

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.

It is also preferable, if p = <NUM> in formula (1a), V stands for C<NUM>-alkylene,.

The weight-average molecular weight Mw of the siloxane block, is preferably <NUM> to <NUM><NUM>/mol, and more preferably <NUM> to <NUM>/mol, determined by gel permeation chromatography using a BPA (bisphenol A) polycarbonate as standard and dichloromethane as eluent. It should be understand that SiCoPC may comprise more than one siloxane block in one polymer chain.

The polysiloxane-polycarbonate block copolymer and the production thereof are described in <CIT>.

Advantageously, the polysiloxane-polycarbonate copolymer is present in the polycarbonate composition according to the present invention in an amount ranging from <NUM> wt. % to <NUM> wt. %, preferably from <NUM> wt. % to <NUM> wt. %, relative to the total weight of the polycarbonate composition.

The polycarbonate composition according to the present invention comprises an amorphous copolyester as component C.

The amorphous copolyester comprises <NUM>,<NUM>-cyclohexanedimethylene terephthalate repeating units having the structure
<CHM>
and <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-cyclobutylene terephthalate repeating units having the structure
<CHM>
wherein * indicates the position where the unit is connected to the polymer chain.

The amorphous copolyester can be obtained by polymerization of <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-cyclobutanediol (TMCBD), terephthalic acid (or dimethyl terephthalate) and <NUM>,<NUM>-cyclohexanediol.

According to the different positions of hydroxyl groups, the monomer TMCBD has cis and trans isomers. The C4 ring of the cis-TMCBD is non-planar and the crystals have a dihedral angle of <NUM>°, while the trans-TMCBD has a dihedral angle of <NUM>° and has a symmetrical structure; the C4 ring is very stable.

Preferably, the copolyester comprises <NUM> wt. % to <NUM> wt. % of the cyclohexanedimethylene terephthalate repeating units and <NUM> wt. % to <NUM> wt. % of the <NUM>,<NUM>,<NUM>,<NUM>-tetramethylcyclobutylene terephthalate repeating units, based on the weight of the copolyester.

Advantageously, the copolyester has a melt volume rate (MVR) of <NUM> to <NUM>/mol, preferably of <NUM> to <NUM>/mol, and more preferably of <NUM> to <NUM>/mol, as measured in accordance with ISO <NUM>-<NUM>: <NUM> at <NUM> under a loading of <NUM>.

Advantageously, the copolyester is present in the polycarbonate composition according to the present invention in an amount ranging from <NUM> wt. % to <NUM> wt. %, preferably from <NUM> wt. % to <NUM> wt. %, relative to the total weight of the polycarbonate composition.

In addition to components A-C mentioned above, the polycarbonate composition according to the present invention can optionally comprise of one or more additional additives conventionally used in polymer compositions, such as lubricants and demoulding agents (e.g. pentaerythritol tetrastearate), antioxidants, stabilizers (such as thermal stabilizers, UV absorbers, IR absorbers), antistatic agents (including inorganic antistatic agents, such as, conductive carbon blacks, carbon fibres, carbon nanotubes and organic antistatic agents), colorants, etc..

The person skilled in the art can select the type and the amount of the additional additives so as to not significantly adversely affect the desired properties of the polycarbonate composition according to the present invention.

Preferably, the composition according to the present invention does not comprise butadiene-based rubber.

Advantageously, the total content by weight of components A)-C) is no less than <NUM> wt. %, preferably no less than <NUM> wt. %, more preferably no less than <NUM> wt. %, relative to the total weight of the polycarbonate composition according to the present invention.

In some preferred embodiments, the thermoplastic polycarbonate composition according to the present invention comprises the following components, relative to the total weight of the composition:.

In some preferred embodiments, the thermoplastic polycarbonate composition according to the present invention consists of the following components, relative to the total weight of the composition:.

The polycarbonate composition according to the present invention can be in the form of, for example, pellets, and can be prepared by a variety of methods involving intimate admixing of the materials desired in the composition.

For example, the materials desired in the composition are first blended in a high speed mixer. Other low shear processes, including but not limited to hand mixing, can also accomplish this blending. The blend is then 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 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 described. Such pellets can be used for subsequent molding, shaping or forming.

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

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

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 <NUM> and <NUM> 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.

In some cases, the molten 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 for packaging and further handling.

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

As used herein, "made from" means that the shaped article comprises the polycarbonate composition according to the first aspect of the present invention, preferably the shaped article consists of the polycarbonate composition according to the first aspect of the present invention.

As examples of shaped articles, mention can be made of, for example, door handle, instrument panel, and body parts or interior trim for commercial vehicles, especially for the motor vehicle sector.

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

Thus, according to the third aspect, the present invention provides a process for preparing the shaped article according to the second aspect of the present invention, comprising injection moulding, extrusion moulding, blowing moulding or thermoforming the polycarbonate composition according to the first aspect of the present invention.

According to the fourth aspect, the present invention provides a use of an amorphous copolyester comprising <NUM>,<NUM>-cyclohexanedimethylene terephthalate repeating unit having the structure
<CHM>
and <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-cyclobutylene terephthalate repeating unit having the structure
<CHM>.

The amorphous copolyester, the aromatic polycarbonate and the polysiloxane-polycarbonate copolymer are the same as defined previously.

Preferably, the amorphous copolyester is present in amount ranging from <NUM> wt. % to <NUM> wt. % in the composition, relative to the total weight of the composition.

Preferably, the polysiloxane-polycarbonate copolymer is present in an amount ranging from <NUM> wt. % to <NUM> wt. %, preferably from <NUM> wt. % to <NUM> wt. %, relative to the total weight of the polycarbonate composition.

Preferably, the copolyester is present in an amount ranging from <NUM> wt. % to <NUM> wt. %, from <NUM> wt. % to <NUM> wt. %, relative to the total weight of the polycarbonate composition.

The Examples which follow serve to illustrate the invention in greater detail.

PC: an aromatic polycarbonate resin having a weight average molecular weight of about <NUM>,<NUM>/mol produced from bisphenol A and phosgene, available from Covestro, Co.

SicoPC: Copolycarbonate based on bisphenol A, siloxane monomer and carbonyl chloride, available as D0013 from the company Unicolour material.

Tritan(C1): a copolymer of dimethyl terephthalate (DMT), <NUM>,<NUM>-cyclohexanedimethanol (CHDM), and <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-cyclobutanediol (TMCBD), with a heat deflection temperature of <NUM> at a thickness of <NUM> and <NUM> megapascals, available as TRITAN™ CopolyesterTX1001 from Eastman Chemical Company.

PCCD(C2): a copolymer of <NUM>,<NUM>-cyclohexanedimethanol (CHDM) and <NUM>,<NUM>-dimethylcyclohexane dicarboxylate (DMCD), available as NEOSTAR COPOLYESTER <NUM> from Eastman Chemical Company∘.

PETG(C3): a copolymer of terephthalic acid (PTA), cylclohexylenedimethylene (CHDM), ethylene glycol (EG), available as GN071 from Eastman Chemical Company, with a heat deflection temperature of <NUM> at <NUM> millimeter thickness and <NUM> megapascals.

PBT(C4): polybutylene terephthalate, having an intrinsic viscosity of <NUM> dl/g, available as <NUM>-<NUM> from ChangChun Plastic.

ABS-<NUM>: a core-shell impact modifier prepared by emulsion polymerization of <NUM> wt. %, based on the ABS polymer, of a mixture of <NUM> wt. % of acrylonitrile and <NUM> wt. % of styrene in the presence of <NUM> wt. %, based on the ABS polymer, of a linear polybutadiene rubber, available as P60 from the company Ineos ABS (Deutschland) GmbH.

ABS-<NUM>: a core-shell impact modifier prepared by emulsion polymerization, available as TERLURAN HI <NUM> Q520 from Ineos ABS (Deutschland) GmbH.

MBS: Methyl methacrylate-butadiene-styrene (MBS) with a core/shell structure, available as Kane Ace M732 from Japan Kaneka Chemical Co.

SAN: styrene-acrylonitrile copolymer, available as LUSTRAN® SAN DN50 from INEOS Styrolution GmbH.

Antioxidant: a mixture of <NUM> wt. % of Irgafos® <NUM> (tris(<NUM>,<NUM>-ditert-butylphenyl)phosphite) and <NUM> wt. % of Irganox® <NUM> (<NUM>,<NUM>-ditert-butyl-<NUM>-(octa-decanoxycarbonylethyl)phenol, available as Irganox® B900 from BASF (China) Company Limited.

Phosphorous acid: from the company Sigma-Aldrich Trade Company.

Carbon Black: available as HIBLACK <NUM> LB from Evonik Oxeno GmbH.

The physical properties of compositions obtained in the examples were tested as follows:
The melt flowability was evaluated by means of the melt volume flow rate (MVR) measured in accordance with ISO <NUM>-<NUM>: <NUM> at a temperature of <NUM> with a plunger load of <NUM> or at a temperature of <NUM> with a plunger load of <NUM>.

The IZOD notched impact strength was measured in accordance with ISO <NUM>/1A:<NUM> under the energy of <NUM>. 5J on a notched single gated specimen with dimensions of <NUM> × <NUM> × <NUM> conditioned under testing temperature for <NUM> hours.

The Vicat softening temperature was determined in accordance with ISO <NUM>: <NUM> on bars of dimensions <NUM> × <NUM> × <NUM> at a heating rate of <NUM>/h.

The tensile stress, the tensile strain at break and tensile modulus were determined at room temperature (<NUM>) in accordance with ISO <NUM>-<NUM>: <NUM> on shoulder bars of dimensions <NUM> × <NUM> × <NUM>.

The odor rank was evaluated in accordance with PV3900-<NUM> as follows:
A <NUM> sample was placed in a <NUM> bowl. A test container was closed tightly and aged at a temperature of <NUM> for <NUM> hours in a preheated desiccator. The evaluation was performed by a minimum of five examiners. The odor was evaluated using the evaluation scale (see Table <NUM>) with grades <NUM> to <NUM>, with half-steps allowed, for all possible variants.

The materials listed in Table <NUM> were compounded in a twin-screw extruder (ZSK-<NUM>) (from Werner and Pfleiderer) at a speed of rotation of <NUM> rpm, a throughput of <NUM>/h, and a machine temperature of <NUM>, and granulated.

The granules obtained were processed on an injection moulding machine (from Arburg) at a melt temperature of <NUM>° C and a mold temperature of <NUM>° C to produce test specimens.

The physical properties of compositions obtained were tested and the results were summarized in Table <NUM>.

As shown in Table <NUM>, the composition of comparative example <NUM> (CE1) not comprising Tritan demonstrates an odor rank of <NUM>.

As demonstrated by compositions of comparative examples <NUM>-<NUM> (CE2-CE5) comprising a common impact modifier such as MBS and not comprising SicoPC have the odor rank of <NUM>.

It can be seen from Table <NUM>, polycarbonate compositions of invention examples <NUM>-<NUM> (IE1-IE4) demonstrates a combination of good odor rank, good impact strength, good flowability, and good heat resistance. However, such a combination of low odor rank, excellent impact strength, good flowability, and good heat resistance can be achieved only when the Tritan content is in a suitable range (i.e. <NUM>-<NUM> wt. When the Tritan content is ≤ <NUM> wt. % (CE6) or > <NUM> wt. % (CE7 and CE8), the odor rank is not acceptable.

As demonstrated by compositions of comparative examples <NUM>-<NUM> (CE <NUM>-<NUM>), pure resins of polycarbonate resin, Tritan, and polysiloxane-polycarbonate copolymer alone all exhibit an odor rank of <NUM>, which is above the desired odor rank of <NUM>, for auto interior applications.

As demonstrated by comparative examples <NUM>-<NUM> (CE <NUM>-<NUM>), other types of amorphous copolyesters (such as PCCD) or semi-crystalline copolyesters (such as PETG and PBT), when blended with polycarbonate, cannot result in the desirable odor rank of <NUM>.

The odor performance is bad, if ABS is included in the composition (CE <NUM>).

Similarly, the materials listed in Table <NUM> were compounded, the physical properties of compositions obtained were tested and the results were summarized in Table <NUM>.

It can be seen from Table <NUM> that when the content of polysiloxane-polycarbonate copolymer is too low (<NUM> wt. % in CE16) or too high (<NUM> wt. % in CE17-CE19), compositions with good odor rank and excellent impact strength at -<NUM> cannot be obtained.

Claim 1:
A thermoplastic polycarbonate composition comprising the following components, relative to the total weight of the composition:
A) <NUM> - <NUM> wt.% of an aromatic polycarbonate not being a polysiloxane-polycarbonate copolymer,
B) <NUM> - <NUM> wt.% of a polysiloxane-polycarbonate copolymer, and
C) <NUM> - <NUM> wt.% of an amorphous copolyester comprising <NUM>,<NUM>-cyclohexanedimethylene terephthalate repeating units having the structure
<CHM>
and <NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-cyclobutylene terephthalate repeating units having the structure
<CHM>
wherein * indicates the position where the unit is connected to the polymer chain and wherein the total content by weight of components A)-C) is not less than <NUM> wt.%, relative to the total weight of the composition.