HK1055127B - Compositions containing polycarbonate - Google Patents

Description

Polycarbonate-containing composition

The present invention relates to the use of specific triazines for the preparation of compositions comprising polycarbonate, these triazines and fatty acid esters, the above compositions, a process for the manufacture of products comprising the above compositions and the above products.

EP-A0110221 discloses polycarbonate sheets, which can be used for many purposes. These sheets can be produced, for example, by extrusion of compositions containing polycarbonate, optionally also by coextrusion with other compositions containing polycarbonate and also large amounts of UV absorbers.

A further problem which arises when extruding these sheets is the deposition of volatile constituents from the molding compositions.

In the machines used for manufacturing sheets, the volatile components are deposited on a calibrator (calibretor) for extruding multilayer sheets and on rollers for extruding solid sheets. This causes defects on the surface of the sheet.

Examples of volatile components include UV absorbers, mold release agents and other low molecular weight components of compositions containing polycarbonate.

EP-A0320632 describes coextruded sheets formed from compositions comprising polycarbonate, a low-volatility UV absorber and possibly a lubricant. Disadvantageously, the surface of the sheet is damaged when the extrusion time is long, particularly in the case of coextrusion. This may be due to volatiles in the polymer melt, for example.

The release of UV absorbers in large amounts from the polycarbonate melt leads to coatings on the calibrator or on the rolls and ultimately to defects (e.g.white spots, ripples, etc.) on the sheet surface. On the calibrator, the polycarbonate also suffers from a powdery deposit on the coextruded polycarbonate sheet.

It is known from WO99/05205 that a mixture of mould release agents consisting of, for example, fatty acid esters of pentaerythritol and glycerol can be used to minimize the formation of deposits on the calibrator or the rollers, which deposits can lead to the formation of defects on the surface of the sheet (e.g. white spots, waviness, etc.).

Various substituted triazine-based UV absorbers are used in polycarbonates, for example, see JP-A09-176476, JP-A09-057881, JP-A09-057813 and EP-A0825226.

JP-A09-176476 describes triazine-containing polycarbonate compositions and sheets and films coated with such polycarbonate compositions.

JP-A09-057881 describes plastic corrugated sheets coated with a triazine-containing polycarbonate composition.

JP-A09-057813 describes a specific process for the production of polycarbonate sheets containing triazine in the cover layer.

EP-A0649724 describes a process for producing a multilayer plastic sheet from a branched polycarbonate with an average molecular weight Mw of 27000-29500 g/mol by coextrusion of a core layer and at least one cover layer with 1 to 15% by weight of UV absorber. If the mould release agents glycerol monostearate, pentaerythritol tetrastearate or mixtures based on glycerol monostearate described in EP-A0300485 are used in the compositions for producing these plastic panels, the surface of the sheets can still deteriorate over time.

It is therefore an object of the present invention to provide polycarbonate compositions which do not have the above-mentioned disadvantages of the prior art when extruded or coextruded.

It is another object of the present invention to provide products, especially multi-layer sheets, containing the compositions of the present invention.

The object of the invention is achieved by the use of compounds of the formula I for the production of compositions comprising polycarbonate, fatty acid esters and one or more compounds of the formula I,

in the formula

R¹、R²、R³And R⁴May be the same or different and are selected from C₁-alkyl to C₈An alkyl group, a halogen and-CN,

R⁵is H or C₁-alkyl to C₂₀An alkyl group.

R⁵N-octyl is preferred.

R¹、R²、R³And R⁴Methyl is also preferred. It is particularly preferred that R⁵Is n-octyl, R¹、R²、R³And R⁴Is methyl.

The object of the invention is also achieved by compositions comprising polycarbonate, fatty acid esters and one or more compounds of the formula I.

In a preferred embodiment of the present invention, the composition of the present invention contains 0.02 to 1% by weight of fatty acid ester. These esters are preferably selected from pentaerythritol tetrastearate, glycerol monostearate and mixtures of the two.

In a preferred embodiment of the present invention, the composition of the present invention further comprises 10 to 3000ppm of a heat stabilizer.

The heat stabilizer is preferably selected from tris (2, 4-di-tert-butylphenyl) phosphite and triphenylphosphine.

The object of the invention is also achieved by a process for the production of products comprising the composition according to the invention by extrusion, coextrusion or injection moulding. Extrusion or coextrusion is preferred.

The object of the invention is also achieved by a product containing a composition according to the invention.

The object of the invention is also achieved by a multilayer product comprising at least one outer layer of a composition according to the invention.

The object of the invention is also achieved by a product comprising a composition according to the invention, said product being selected from the group consisting of sheets, solid sheets, multiwall sheets, corrugated solid sheets, corrugated multiwall sheets, multilayer profiles, glazing, greenhouse glazing, conservatories, bus shelters, billboards, signs, protective screens, automotive glazing, windows and roofs.

Particularly preferred products of the invention are multilayer sheets comprising the composition of the invention in at least one of the two outer layers.

The product of the invention contains the composition of the invention. Preferably, these products consist essentially of the composition of the invention. It is particularly preferred that these products consist of the composition of the invention. In the case of a multilayer product, the above conditions apply to one or more layers of the product.

The composition of the invention is preferably applied as a cover layer to a polycarbonate sheet having a thickness of 5 to 80 microns. The coating is preferably carried out by coextrusion.

The composition of the present invention preferably contains 1 to 7% by weight, more preferably 2 to 5% by weight of the compound represented by the formula I.

The compounds of formula I can be prepared by known methods. It may be prepared, for example, as described in WO 00/14075, US-A556973, US-A5648488 or US-A5675004. Specific examples of compounds of formula I are commercially available, such as Cyasorb * UV 1164 (trade name, available from Cytec industries B.V., Botlek, Netherlands).

The compositions according to the invention containing polycarbonate have proven particularly advantageous. They can be processed without difficulty and without damaging the articles obtained as products. It has surprisingly been found that the problems mentioned at the outset do not occur when using these compositions even when additives known to volatilize are added to compositions comprising polycarbonate.

The polycarbonates according to the invention are either carbonate homopolymers, carbonate copolymers or thermoplastic polyester carbonates (polyester carbonates). The average molecular weights Mw, determined by measuring them in dichloromethane or an equimolar mixture of phenol and o-dichlorobenzene with respect to the solution viscosity, as corrected by light scattering, are preferably from 18,000 to 40,000 g/mol, more preferably from 26000 to 36000 g/mol, and particularly preferably from 28,000 to 35,000 g/mol.

In the case of the production of multilayer products, the melt viscosity of the compositions containing the polycarbonates is preferably lower than the melt viscosity of the substrates to which they are applied.

As for the method for producing a polycarbonate for a composition containing a polycarbonate, see "Schnell" (chemistry and physics of polycarbonates, "review of polymers", volume 9, Interscience publishing company, new york, london, sydney, 1964), "Synthesis of Poly (ester) carbonates copolymers" by "polymers of polycarbonate copolymers" by "b.t. debona and y.kesten (joint chemical company co-research center, Moristown, new jersey 07960)" ("journal of polymer science, edition of polymer chemistry, volume 19, pages 75-90 (1980)), d.freitag; "polycarbonates" by Grigo, P.R.Muller, N.Nouvertne (Bayer) (encyclopedia of Polymer science and engineering, Vol. 11, second edition, 1988, 648-.

The production is preferably carried out by the phase boundary method or the melt transesterification method, and the production process is described below by taking the phase boundary method as an example.

Preferred compounds used as starting materials are bisphenols of the general formula HO-Z-OH, wherein Z is a divalent organic radical containing 6 to 30 carbon atoms and one or more aromatic groups.

Examples of such compounds are bisphenols belonging to the following group: dihydroxybiphenyl, bis (hydroxyphenyl) alkane, 1, 2-indane bisphenol, bis (hydroxyphenyl) ether, bis (hydroxyphenyl) sulfone, bis (hydroxyphenyl) ketone, and α, α' -bis (hydroxyphenyl) diisopropylbenzene.

Particularly preferred bisphenols which belong to the abovementioned compounds are bisphenol A, tetraalkylbisphenol A, 4- (M-phenylenediisopropyl) bisphenol (bisphenol M), 4- (p-phenylenediisopropyl) bisphenol, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane (BP-TMC), and also mixtures thereof.

Particularly preferred polycarbonates are the homopolymer of a carbonate based on bisphenol A and the copolymer of a carbonate based on bisphenol A and 1, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane monomer.

The bisphenol compounds used according to the invention are reacted with carbonic acid compounds, in particular phosgene, or, in the melt transesterification process, with diphenyl carbonate or dimethyl carbonate.

The polyester carbonates are prepared by reacting the aforementioned bisphenols, at least one aromatic dicarboxylic acid, and optionally carbonic acid equivalents. Examples of suitable aromatic dicarboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, 3 '-or 4, 4' -diphenyl dicarboxylic acid and benzophenone dicarboxylic acid. In the case of polyester polycarbonates, up to 80 mol%, preferably from 20 to 50 mol%, of the carbonate groups in the polycarbonate may be replaced by aromatic dicarboxylic acid ester groups.

Examples of the inert organic solvent used in the phase boundary method include dichloromethane, various dichloroethane and chloropropane compounds, tetrachloromethane, trichloromethane, chlorobenzene and chlorotoluene, with chlorobenzene or dichloromethane or a mixture of dichloromethane and chlorobenzene being preferably used.

Catalysts such as tertiary amines, especially N-alkylpiperidines or onium salts, may be used to promote the phase boundary reaction. Tributylamine, triethylamine and N-ethylpiperidine are preferably used.

In the melt transesterification process, preference is given to using the catalysts described in DE-A4238123.

The polycarbonates may be branched deliberately or controllably with small amounts of branching agents. Suitable branching agents include: phloroglucinol, 4, 6-dimethyl-2, 4, 6-tris (4-hydroxyphenyl) -2-heptene; 4, 6-dimethyl-2, 4, 6-tris (4-hydroxyphenyl) heptane; 1, 3, 5-tris (4-hydroxyphenyl) benzene; 1, 1, 1-tris (4-hydroxyphenyl) ethane; tris (4-hydroxyphenyl) phenylmethane; 2, 2-bis [4, 4-bis (4-hydroxyphenyl) cyclohexyl ] propane; 2, 4-bis (4-hydroxyphenyl isopropyl) phenol; 2, 6-bis (2-hydroxy-5' -methylbenzyl) -4-methylphenol; 2- (4-hydroxyphenyl) -2- (2, 4-dihydroxyphenyl) propane; hexa (4- (4-hydroxyphenyl isopropyl) phenyl) ortho-terephthalate; tetrakis (4-hydroxyphenyl) methane; tetrakis- (4- (4-hydroxyphenyl isopropyl) phenoxy) methane; α, α', α "-tris (4-hydroxyphenyl) -1, 3, 5-triisopropylbenzene; 2, 4-dihydroxybenzoic acid; trimesic acid; cyanuric chloride; 3, 3-bis (3-methyl-4-hydroxyphenyl) 2-oxo-2, 3-indoline; 1, 4-bis (4', 4 "-dihydroxytriphenyl) methyl) benzene, in particular 1, 1, 1-tris (4-hydroxyphenyl) ethane and bis (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-indoline.

Optionally, 0.05 to 2 mol%, relative to the bisphenols used, of a branching agent or branching agent mixture may be used, either together with the bisphenols or added at a later stage of the synthesis.

Chain terminators may be used. Preference is given to using phenol; alkylphenols, such as cresols and 4-tert-butylphenol, chlorophenol, bromophenol, cumylphenol or mixtures thereof, are preferably used as chain terminators in amounts of from 1 to 20 mol%, particularly preferably from 2 to 10 mol%, per mol of bisphenol. Phenol, 4-tert-butylphenol or cumylphenol are preferably used.

Chain terminators and branching agents may be added separately to the synthesis system or may be added together with the bisphenols.

The process for the manufacture of the polycarbonates used in the polycarbonate-containing compositions according to the invention is carried out according to the melt transesterification process, for example, as described in DE-A4238123.

UV absorbers, in particular compounds of the formula I, are incorporated into the polycarbonate-containing compositions according to the invention by customary methods, for example in suitable organic solvents (e.g. CH)₂Cl₂Halogenated alkanes, halogenated aromatic hydrocarbons, chlorobenzene, and xylene) are mixed with the polycarbonate solution. The mixture of these substances is then homogenized in a known manner by extrusion; the solution mixture is removed (e.g. compounded) by known methods such as evaporation to remove the solvent followed by extrusion.

The compositions containing the polycarbonates may also contain stabilizers.

Suitable polycarbonate stabilizers for the polycarbonate-containing compositions according to the invention are, for example, phosphines, phosphites or silicon-containing stabilizers and further compounds as described in EP-A0500496. Examples which may be mentioned include triphenyl phosphite, diphenylalkyl phosphites, phenyldialkyl phosphites, tris (nonylphenyl) phosphite, tetrakis (2, 4-di-tert. -butylphenyl) -4, 4' -biphenylene diphosphite and triaryl phosphites. Triphenyl phosphite and tris (2, 4-di-tert-butylphenyl) phosphite are particularly preferred.

The molding compositions of the invention contain fatty acid esters. They are (partial) esters of tetra-to hexa-hydric alcohols, particularly preferably pentaerythritol.

Examples of tetrahydric alcohols include pentaerythritol and meso-erythritol.

Examples of pentahydric alcohols include arabitol, ribitol, and xylitol.

Examples of hexahydric alcohols include mannitol, glucitol (sorbitol), and galactitol.

These esters are saturated aliphatic C₁₀-C₂₆Monocarboxylic acids (preferably saturated aliphatic C)₁₄-C₂₂Monocarboxylic acids), optionally penta-and hexa-esters or mixtures thereof, particularly preferably static (static) mixtures.

Depending on the production process, commercially available fatty acid esters, in particular of pentaerythritol, may contain < 60% of different partial esters.

Examples of saturated aliphatic monocarboxylic acids having from 10 to 26 carbon atoms include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and cerotic acid.

Examples of preferred saturated aliphatic monocarboxylic acids having 14 to 22 carbon atoms include myristic acid, palmitic acid, stearic acid, arachic acid and behenic acid.

Saturated aliphatic monocarboxylic acids such as palmitic acid and stearic acid are particularly preferred.

Saturated aliphatic C for use in the invention₁₀～C₂₆The carboxylic acids and fatty acid esters of (A) are known per se from the literatureKnown or may be made by known methods in the literature. Examples of pentaerythritol fatty acid esters are the esters of the above-mentioned particularly preferred monocarboxylic acids.

Esters of pentaerythritol with octadecanoic acid and hexadecanoic acid are particularly preferred.

The moulding compositions according to the invention may also contain glycerol mono-fatty acid esters. The glycerol mono-fatty acid ester is glycerol and saturated aliphatic C₁₀～C₂₆Monocarboxylic acids (especially with saturated aliphatic C)₁₄～C₂₂Monocarboxylic acids) are used. Their higher volatility no longer leads to the aforementioned problems for the molding compositions of the invention.

Glycerol mono-fatty acid esters are understood to be both esters of the primary hydroxyl group of glycerol and esters of the secondary hydroxyl group of glycerol and also mixtures of these isomeric compounds. Depending on the preparation process, these fatty acid monoglycerides may contain < 50% of different diglycerides and triglycerides.

Examples of saturated aliphatic monocarboxylic acids having from 10 to 26 carbon atoms include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and cerotic acid.

Examples of preferred saturated aliphatic monocarboxylic acids having 14 to 22 carbon atoms include myristic acid, palmitic acid, stearic acid, arachic acid and behenic acid.

Saturated aliphatic monocarboxylic acids such as palmitic acid and stearic acid are particularly preferred.

Saturated aliphatic C for use in the invention₁₀～C₂₆The carboxylic acids and glycerol mono-fatty acid esters of (a) are known per se from the literature or can be prepared by processes known from the literature (see, for example, Fieser and Fieser, Organisehe chemistry GmbH, Weinheim, Bergstr.1965, chapter 30, page 1206). Examples of glycerol mono-fatty acid esters are the esters of the above-mentioned particularly preferred monocarboxylic acids.

The polycarbonate-containing composition may further contain an antistatic agent. Examples of antistatic agents are cationic compounds, such as quaternary ammonium, phosphonium or sulfonium salts; anionic compounds, such as alkylsulfonates, alkylsulfates, alkylphosphates, carboxylates in the form of alkali metal or alkaline earth metal salts; nonionic compounds, such as polyethylene glycol esters, polyethylene glycol ethers, fatty acid esters, ethoxylated fatty amines. Preferred antistatic agents are nonionic compounds.

The compositions of the present invention and products made therefrom may also contain organic colorants, inorganic colored pigments, fluorescent colorants and particularly preferred optical brighteners.

All the starting materials and solutions used for the synthesis of the polycarbonate-containing compositions according to the invention can be contaminated with corresponding impurities during the production and storage, and the aim is achieved with starting materials which are as pure as possible.

The components can be mixed by known methods, continuously or simultaneously, at room temperature or at elevated temperature.

The additives can be incorporated into the above-mentioned compositions comprising polycarbonate by known methods, for example by mixing the polymer particles and the additives in conventional apparatus, such as internal mixers, single-screw extruders and twin-screw extruders, at temperatures of about 200 ℃ and 330 ℃ or by mixing the polymer solution with the additive solution and evaporating off the solvent in a known manner.

The amount of additives in the above polycarbonate-containing compositions may vary within wide limits and depends on the desired properties of the polycarbonate-containing compositions. The total amount of additives in the polycarbonate-containing composition is preferably up to about 20% by weight, preferably 0.2 to 12% by weight, based on the weight of the polycarbonate-containing composition.

As shown in the examples of the present invention, the use of the polycarbonate-containing compositions of the invention as coextruded layers offers significant advantages for other polycarbonate-containing compositions used as sheet substrates, especially when the substrate of the sheet is also treated with the UV absorbers and the release agents of the polycarbonate-containing compositions of the invention.

The above-described polycarbonate-containing compositions can be used for the production of solid plastic sheets and so-called multilayer sheets (e.g.two-layer sheets, three-layer sheets, etc.). These sheets also include sheets which have on one or both sides an additional outer layer comprising the polycarbonate-containing composition of the invention.

The polycarbonate-containing compositions of the invention simplify the manufacture of products, in particular sheets and products made therefrom, such as glazings for greenhouses, conservatories, bus shelters, billboards, signs, protective screens, automotive glazings, windows and roofs.

The treated product may also be subsequently coated with the polycarbonate-containing compositions of the invention, for example by deep-drawing or surface treatment, for example to provide scratch-resistant coatings, water-spreading layers, etc., and the invention also provides products produced by these processes.

Co-extrusion per se is described in the literature (see, for example, EP-A0110221 and EP-A0110238). The coextrusion is preferably carried out as follows:

the extruders used to make the core and outer layers were connected to an coextrusion adapter (adapter). The adapter is designed such that the melt forming the outer layer is applied in a thin layer and melt bonded to the core layer.

The multilayer melt extrudate thus produced is then brought into the desired form (multilayer sheet or solid sheet) in a downstream connected die. The melt is then calendered (solid sheet) or vacuum-formed (multilayer sheet) under controlled conditions in a known manner, allowed to cool, and then cut to length. After the setting stage, a tempering furnace may optionally be used to relieve the stress. Instead of an adapter arranged upstream of the die, the die itself can also be designed in such a way that the melt is compounded there.

The present invention is further illustrated with reference to the following examples, but is not limited to these examples.

Examples

10 mm two-layer sheets A-E as described in EP-A0110238 were produced from the following compositions containing polycarbonate: the base material used is Makrolon^*KU 1-1243[ branched bisphenol A polycarbonate available from Levokusen Bayer, Germany, melt flow index at 300 ℃ and 1.2 kg load (MFR 6.5 g/10 min)]. The above base stocks were mixed with a base stock based on Makrolon as shown in the table^*3100 (linear bisphenol a polycarbonate, available from levokuss bayer, germany, melt flow index at 300 ℃ and 1.2 kg load (MFR 6.5 g/10 min)).

The thickness of the coextruded layer is in each case approximately 50 μm.

Sheet material	Ultraviolet absorber	Release agent	Heat stabilizer
				A	3.5％Tinuvin 360*	0.1％PETS*)0.05％GMS**)	-
B	3.5% of a compound of the formula I, wherein R5Is ═ n-octyl, and R1＝R2＝R3＝R4Methyl group	0.1％PETS*)0.05％GMS**)	-
				C	3.5% Compound II	0.1％PETS*)0.05％GMS**)	-
D	3.5% of a compound of the formula I, wherein R5Is ═ n-octyl, and R1＝R2＝R3＝R4Methyl group	-	-
				E	3.5% of a compound of the formula I, wherein R5Is ═ n-octyl, and R1＝R2＝R3＝R4Methyl group	0.1％PETS*)0.05％GMS**)	0.05％Irgafos168***)

^*) Pentaerythritol tetrastearate, for example under the trade name Loxiol^*EP129 is available from CognisDusseldorf, Germany.

^**) Glyceryl monostearate, e.g. under the trade name Lixiol^*VPG861 was purchased from CognisDusseldorf, Germany.

^***) Tris (2, 4-di-tert-butylphenyl) phosphite, commercially available from Ciba Spezialitatenchemie, Lampertheim, Germany.

Tinuvin^*360 is 2, 2-methylenebis (4- (1, 1, 3, 3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol.

Compound II (with Tinuvin)^*1577 commercially available):

the following describes a machine and an apparatus for manufacturing a multiwall sheet.

The device is composed of the following parts

Main extruder equipped with a screw 33D in length and 70 mm in diameter and with venting holes

Coextrusion adapter (feeding system)

Coextrusion machine for applying coatings, equipped with a screw 25D in length and 30 mm in diameter

Special sheet extrusion die with a width of 350 mm

-a sizing sleeve

-roller conveyor

-a lead-out arrangement

-revolving knife (saw)

-a transport table.

The polycarbonate granules forming the base material were supplied to the feed hopper of the main extruder and the UV co-extrusion material was supplied to the feed hopper of the co-extruder. The relevant raw materials are melted and conveyed in the respective barrel/screw plasticizing systems. Both raw material melts were collected in a coextrusion adapter and after leaving the die and the calibrator to cool, a composite was formed, and other devices were used to convey, cut lengths and stack the extruded sheets.

Coextrusion with a (reference):

first occurrence of small deposits after 4 hours

After 3 hours, slight striations occurred at irregular intervals, which had a slightly negative effect on the sheet quality.

-4¹/₂After hours there were slightly more accentuated striations.

-grade: good taste

Coextrusion with B (reference):

absence of deposits within a test period of 5 hours

Slight cross-hatching occurred throughout the test, which had no adverse effect on the sheet quality

-grade: is very good

Co-extrusion with C:

first appearance of slight deposits after 2 hours

Slight striations at irregular intervals after 150 minutes, which had a slightly adverse effect on the sheet quality

After-3.5 hours, obvious striations appeared

-grade: difference (D)

Co-extrusion with D:

first appearance of a minor amount of deposits after 50 minutes

Slight striations at irregular intervals after 60 minutes, which had a slightly adverse effect on the sheet quality

After 3 hours, obvious transverse striations appear

-grade: and (4) poor.

Coextrusion with E (reference):

absence of deposits within a test period of 5 hours

Slight cross-hatching occurred throughout the test, which had no adverse effect on the sheet quality

-grade: is very good

Example C shows that very poor sheet quality is obtained with compound II.

The volatility of the compounds of the general formula I and of the compounds II is very similar (Table 1). It was therefore assumed that the same poor surface quality would be obtained with compounds of the formula I which are very similar in chemical properties when the same mold release agent mixture is used in compositions containing polycarbonate. Surprisingly, however, good sheet quality can be achieved over a much longer period with this compound. Even over a longer period of time, the sheet quality was still better than the composition described in WO99/052025 (sheet A in this case).

Comparative tests B and D show that coextrusion alone in the case of ternary compositions leads to high quality sheets, due to the surprising synergistic effect.

TABLE 1

Volatility measurement under nitrogen atmosphere by thermogravimetric analysis (TGA) as described in ISO 7112

	280℃	Residual weight 320 deg.C	400℃
				A compound of the general formula I: (R)1＝R2＝R3＝R4＝CH3；R5Being octyl group)	99％	95％	39％
Compound II	99％	94％	37％

Claims (5)

1. Compositions comprising polycarbonate, fatty acid ester and one or more compounds of formula I,

in the formula

R¹、R²、R³And R⁴Are the same or different and are selected from C₁-alkyl to C₈-alkyl, halogen and-CN,

R⁵is H or C₁-alkyl radicalTo C₂₀-an alkyl group,

the concentration of the compound shown in the general formula I in the composition is 1-7 wt%, and the composition contains 0.02-1 wt% of fatty acid ester.

2. The composition of claim 1 wherein the fatty acid ester is selected from the group consisting of pentaerythritol tetrastearate, glycerol monostearate, and mixtures thereof.

3. The composition of claim 1, wherein the composition further comprises 10 to 3000ppm of a heat stabilizer.

4. A composition according to claim 3 wherein said heat stabilizer is selected from the group consisting of tris (2, 4-di-tert-butylphenyl) phosphite and triphenylphosphine.

5. Use of a composition according to claim 1 for the manufacture of a product by extrusion, coextrusion or injection moulding.