Method for the manufacture of article having low gloss

Abstract

The invention relates to a method for the manufacture of an article comprising the steps of i) moulding a polymer composition comprising a first polymer selected from the group consisting of polycarbonate, polycarbonate-polyorganosiloxane copolymers, polycarbonate-polyester copolymers, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile / butadiene / styrene copolymer (ABS), polypropylene and polycyclohexylene dimethylene terephthalate (PCTG) and combinations thereof and carbon black into an article having a first surface having a first gloss at 60° measured according to ASTM D2457 and ii) exposing the first surface to radiation having a wavelength in the range of from 10 – 300nm, preferably from 100 – 280 nm, to obtain a second, exposed surface part having a second gloss at 60° measured according to ASTM D2457 which is lower than the first gloss.

Description

24POLY0015-WO-ORD 1METHOD FOR THE MANUFACTURE OF ARTICLE HAVING LOW GLOSSThe present invention relates to a method for the manufacture of an article having a low gloss. The present invention further relates to the article obtainable by such method.Low gloss articles are desired for a wide range of applications, from automobile components, to decorative articles, to housings for electronic appliances, such as computers. In some cases, low gloss is required e.g. in automotive to prevent glare of sunlight to the car driver.A low gloss finish for a plastic article can be obtained using different methods.Mechanically texturing a plastic surface has long been used. It is also known to obtain a low gloss article by modifications to the mouldable thermoplastic composition itself. In this case, an article can have a low gloss surface is obtained immediately after processes such as moulding, casting, extruding, or rolling of a suitable low gloss composition.W02008100327A1 discloses a thermoplastic composition comprising: a polycarbonate, an impact modifier composition comprising ABS or BABS, a second impact modifier different from BABS or ABS, an aromatic vinyl copolymer, and a gel-type low gloss additive. The 60° gloss of the thermoplastic composition is measured to be less than or equal to 11.3 GU on 3 millimeter chips having a textured surface when measured according to ASTM D2457.It is an objective of the present invention to provide a method for the manufacture of an article having a low gloss.The present invention provides a method for the manufacture of an article comprising the steps ofi) moulding a polymer composition comprising a first polymer selected from the group consisting of polycarbonate, polycarbonate-polyorganosiloxane copolymer, polycarbonate-polyester copolymer, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile / butadiene / styrene copolymer (ABS), polypropylene and polycyclohexylene dimethylene terephthalate (PCTG) and combinations thereof24POLYOQ15-WO-ORD 2and carbon black into an article having a first surface having a first gloss at 60° measured according to ASTM D2457,ii) exposing the first surface to radiation having a wavelength in the range of from 10 - 300nm, preferably from 100 - 280 nm, to obtain a second, exposed surface part having a second gloss at 60° measured according to ASTM D2457 which is lower than the first gloss.According to the invention, a surface of an article made from a polymer composition comprising carbon black is exposed to radiation. It was found that this can cause reduction of the surface gloss. It was further found that organic dyes do not result in such reduction of the surface gloss.Without wishing to be bound by any theory, it is speculated that the first polycarbonate and organic dyes are degraded by the radiation while carbon black has a higher resistance to such degradation than the first polycarbonate and organic dyes, causing a surface enrichment of uncovered carbon black at the article surface. It was further observed that a low dose of the radiation results in an increase of the surface gloss. Again without wishing to be bound by any theory, it is speculated that this initial increase in the surface gloss is caused by the change in the surface microstructure of the article by the initial radiation. According to the invention, the conditions of the radiation are selected such that the resulting gloss is lower than the gloss before radiation.First surfaceThe article has a first surface which is to be subjected to radiation, which first surface has a first gloss at 60° measured according to ASTM D2457. It will be appreciated that the article can have other surface(s) which are not subjected to radiation. It will further be appreciated that the article can have further surface(s) which are subjected to radiation.The first surface may be a relatively smooth surface or a relatively rough surface, e.g. a textured surface. Texturing is sometimes referred to as graining or engraving and can involve adding a pattern (the texture or grain) to the moulding surface of a mould. This allows the mould to impress that pattern on each moulded part, providing a textured surface.In some embodiments, the first gloss is at least 50, for example at least 60.24POLYOQ15-WO-ORD 3In some embodiments, the first gloss is less than 50, for example at most 40. When the first gloss is low, the change in the colour of the irradiated surface, in particular the change in L* value, is small. A textured surface may have such low first gloss.Exposed surfaceExposing the first surface to radiation according to the invention provides a second, exposed surface part having a second gloss at 60° measured according to ASTM D2457. Preferably, the second, exposed surface part of the article has a second gloss of at most 90% relative to the first gloss, more preferably the second gloss is at most 75%, at most 70%, at most 50% or at most 25% of the first gloss.The second gloss at 60° measured according to ASTM D2457 may e.g. be at most 60, at most 50, at most 40, at most 30, at most 20 or at most 10.RadiationThe exposing is carried out by a radiation having a wavelength in the range of from 10 - 300nm, preferably from 100 - 280 nm.Preferably, said exposing is carried out with a UV-C light source.It was observed that a higher amount of energy results in a greater reduction of gloss.The total amount of energy to which the first surface is exposed is at least 0.5 kJ / cm2, preferably at least 2 kJ / cm2, for example 2 to 20 kJ / cm2, such as 3 kJ / cm2, 4 kJ / cm2, 5 kJ / cm2, 6 kJ / cm2, 7 kJ / cm2, 8 kJ / cm2, 9 kJ / cm2, 10 kJ / cm2, 11 kJ / cm2, 12 kJ / cm2, 13 kJ / cm2, 14 kJ / cm2or 15 kJ / cm2. The radiation power to which the first surface is exposed may e.g. be 7-8 mW / cm2.Polycarbonate compositionThe composition used for obtaining the article according to the invention comprises a first polymer. The first polymer is selected from the group consisting of polycarbonate, polycarbonate-polyorganosiloxane copolymer, polycarbonate-polyester copolymer, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile / butadiene / styrene copolymer (ABS), polypropylene and polycyclohexylene dimethylene terephthalate (PCTG) and combinations thereof.24POLYOQ15-WO-ORD 4Preferably, the first polymer is or comprises polycarbonate. For example, the first polymer is polycarbonate or the first polymer is polycarbonate and one or more polymers selected from the group consisting of polycarbonate-polyorganosiloxane copolymers, polycarbonate-polyester copolymers, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile / butadiene / styrene copolymer (ABS), polypropylene and polycyclohexylene dimethylene terephthalate (PCTG).The amount of the first polymer in the composition may e.g. be at least 60 wt%, for example at least 80 wt%, at least 90 wt%, at least 95 wt% or at least 99 wt.% or 100 wt% on the basis of the total amount of polymers in the polymer composition.The amount of polycarbonate in the composition may e.g. be at least 60 wt%, for example at least 80 wt%, at least 90 wt%, at least 95 wt% or at least 99 wt.% or 100 wt% on the basis of the total amount of polymers in the polymer composition.The polycarbonate in the polymer composition can be a mixture of at least two polycarbonates which each may be a homopolymer or a copolymer. A specific example of a mixture consists of bisphenol A polycarbonate homopolymer and a polycarbonatepolysiloxane copolymer. It is preferred that the polycarbonate is a polycarbonate homopolymer obtained by reacting a bisphenol, such as bisphenol A, with a carbonate source such as phosgene or a diarylcarbonate such as diphenyl carbonate.Accordingly the polycarbonate of the composition according to the invention may be prepared using the so called interfacial process, wherein BPA reacts with phosgene, or may be prepared by means of the so-called melt or direct transesterification process, wherein BPA reacts with diphenyl carbonate. These two types of polycarbonate are known to the skilled person and may be further referred to herein as interfacial polycarbonate and melt polycarbonate. The skilled person knows that these two types of polycarbonate differ in amount of Fries branching, which only exists in melt polycarbonate and further in the terminal hydroxyl content, which is typically much lower for interfacial polycarbonate.It is preferred that the polycarbonate is obtained via the interfacial process for the reason that said process, compared to the melt process, typically provides polycarbonate with a low number of hydroxyl chain ends. A low amount of hydroxyl chain ends is advantageous for heat stability and colour retention of the polycarbonate. Nonetheless, polycarbonate obtained via the melt process, i.e. melt polycarbonate, is not excluded from being used in the present invention. In an embodiment the24POLY0015-WO-ORD 5polycarbonate is a mixture of at least one polycarbonate obtained via the interfacial process and at least one polycarbonate obtained with the melt process. In such an embodiment the amount of melt polycarbonate may e.g. be from 30 - 70 wt.% and the amount of interfacial polycarbonate from 70 - 30 wt.%, based on the combined weight of the melt polycarbonate and the interfacial polycarbonate.It is preferred that the polycarbonate comprises or consists of interfacial polycarbonate. It is further preferred that the polycarbonate is an interfacial polycarbonate prepared by reacting bisphenol A and phosgene. Accordingly it is preferred that the polycarbonate is a bisphenol A polycarbonate or a bisphenol A polycarbonate homopolymer.In some embodiments, at least 95 wt%, at least 98 wt% or at least 99 wt% of the polycarbonate is interfacial polycarbonate, for example a bisphenol A polycarbonate or a bisphenol A polycarbonate homopolymer.In some embodiments, at least 95 wt%, at least 98 wt% or at least 99 wt% of the polycarbonate is melt polycarbonate, for example a bisphenol A polycarbonate or a bisphenol A polycarbonate homopolymer.Preferably, the polycarbonate, or mixture of polycarbonates, has a melt volume rate according to ISO1133-1 :2011 at 300 °C and 1.2 kg of from 3 to 35 cm3 / 1 Omin, for example 10 to 30 cm3 / 10min.Preferably, the polymer composition has a melt volume rate according to ISO1133-1:2011 at 300 °C and 1.2 kg of from 3 to 35 cm3 / 10min for example 10 to 30 cm3 / 10min.Polycarbonate and its production methods are per se well-known and is further described in detail e.g. in W02014130751,

[0037] -

[0082] , incorporate herein by reference.Carbon blackThe composition used for obtaining the article according to the invention comprises carbon black. It was observed that a higher amount of carbon black results in a greater reduction of gloss.24POLY0015-WO-ORD 6Preferably, the amount of carbon black is at least 0.005 wt.%, for example 0.005 to 30 wt.%. More preferably, the amount of carbon black is at least 0.01 wt.% based on the weight of the composition. More preferably, the amount of carbon black is 0.05 to 25 wt%, 0.10 to 20 wt%, 0.20 to 10 wt%, 0.30 to 5.0 wt%, 0.4 to 3.0 wt% or 0.5 to 2.0 wt%.Further colorantsIn some preferred embodiments, the composition comprises further colorants, for example inorganic pigments and / or organic pigments and / or organic dyes. Further colorants can be advantageously used to obtain the desired colour in the final article.The amount of the further colorants may e.g. be 0.005 to 10 wt%, 0.05 to 8.0 wt%, 0.10 to 6.0 wt%, 0.30 to 5.0 wt%, 0.4 to 3.0 wt% or 0.5 to 2.0 wt%.The amount of the inorganic pigments may e.g. be 0.005 to 10 wt%, 0.05 to 8.0 wt%, 0.10 to 6.0 wt%, 0.30 to 5.0 wt%, 0.4 to 3.0 wt% or 0.5 to 2.0 wt%.It was observed that the presence of organic pigments or dyes can increase the gloss particularly when the amount of carbon black in the polymer composition is small. In some embodiments, the composition does not comprise organic pigments or dyes or comprises organic pigments or dyes at an amount of less than 0.005 wt%, less than 0.003 wt% or less than 0.001 wt%.Suitable examples of inorganic pigments include metal oxides and mixed metal oxides such as zinc oxide, titanium dioxides, iron oxides and the like; sulfides such as zinc sulfides, and the like; aluminates; sodium sulfo-silicates sulfates, chromates, and the like; zinc ferrites; ultramarine blue; Pigment Brown 24; Pigment Red 101 and Pigment Yellow 119.Suitable examples of organic pigments include azos, di-azos, quinacridones, perylenes, naphthalene tetracarboxylic acids, flavanthrones, isoindolinones, tetrachloroisoindolinones, anthraquinones, anthanthrones, dioxazines, phthalocyanines, and azo lakes; Pigment Blue 60, Pigment Red 122, Pigment Red 149, Pigment Red 177, Pigment Red 179, Pigment Red 202, Pigment Violet 29, Pigment Blue 15, Pigment Green 7, Pigment Yellow 147 and Pigment Yellow 150, and combinations comprising at least one of the foregoing pigments.24POLYOQ15-WO-ORD 7Inorganic and organic pigments may be coated to prevent reactions with the matrix or may be chemically passivated to neutralize catalytic degradation site that might promote hydrolytic or thermal degradation.Suitable examples of organic dyes include coumarin dyes such as coumarin 460 (blue), coumarin 6 (green), nile red and the like; lanthanide complexes; hydrocarbon and substituted hydrocarbon dyes; polycyclic aromatic hydrocarbon dyes; scintillation dyes such as oxazole or oxadiazole dyes; aryl- or heteroaryl-substituted poly (C2-8) olefin dyes; carbocyanine dyes; indanthrone dyes; phthalocyanine dyes; oxazine dyes; carbostyryl dyes; napthalenetetracarboxylic acid dyes; porphyrin dyes; bis(styryl)biphenyl dyes; acridine dyes; anthraquinone dyes; cyanine dyes; methine dyes; arylmethane dyes; azo dyes; indigoid dyes, thioindigoid dyes, diazonium dyes; nitro dyes; quinone imine dyes; aminoketone dyes; tetrazolium dyes; thiazole dyes; perylene dyes, perinone dyes; bis-benzoxazolylthiophene (BBOT); triarylmethane dyes; xanthene dyes; thioxanthene dyes; naphthalimide dyes; lactone dyes; fluorophores such as anti- stokes shift dyes which absorb in the near infrared wavelength and emit in the visible wavelength, and the like; luminescent dyes such as 5-amino-9-diethyliminobenzo(a)phenoxazonium perchlorate; 7-amino-4- methylcarbostyryl; 7-amino-4-methylcoumarin; 7-amino-4-trifluoromethylcoumarin; 3-(2'-benzimidazolyl)-7-N,N-diethylaminocoumarin; 3-(2'-benzothiazolyl)-7- diethylaminocoumarin; 2-(4-biphenylyl)-5-(4-t-butylphenyl)-l ,3,4-oxadiazole; 2-(4- biphenylyl)-5-phenyl- 1,3,4-oxadiazole; 2-(4-biphenyl)-6-phenylbenzoxazole-1,3; 2,5- bis-(4-biphenylyl)- 1 ,3,4-oxadiazole; 2,5-bis-(4-biphenylyl)-oxazole; 4,4'-bis-(2- butyloctyloxy)-p-quaterphenyl; p-bis(o-methylstyryl)-benzene; 5,9- diaminobenzo(a)phenoxazonium perchlorate; 4-dicyanomethylene-2-methyl-6-(p- dimethylaminostyryl)-4H-pyran; l,l'-diethyl-2,2'-carbocyanine iodide; 1,1 '-diethyl- 4,4'-carbocyanine iodide; 3,3'-diethyl-4,4',5,5'-dibenzothiatricarbocyanine iodide; 1,1'- diethyl-4, 4'-dicarbocyanine iodide; 1 ,1 ’-diethyl-2,2'-dicarbocyanine iodide; 3,3'- diethyl-9,11 -neopentylenethiatricarbocyanine iodide; 1 ,3'-diethyl-4,2'- quinolyloxacarbocyanine iodide; 1 ,3'-diethyl-4,2'-quinolylthiacarbocyanine iodide; 3-diethylamino-7-diethyliminophenoxazonium perchlorate; 7-diethylamino-4-methylcoumarin; 7-diethylamino-4-trifluoromethylcoumarin; 7- diethylaminocoumarin; 3,3'-diethyloxadicarbocyanine iodide; 3,3'- diethylthiacarbocyanine iodide; 3,3'-diethylthiadicarbocyanine iodide; 3,3'-diethylthiatricarbocyanine iodide; 4,6-dimethyl-7-ethylaminocoumarin; 2,2'-dimethyl- p-quaterphenyl; 2,2-dimethyl-p-terphenyl; 7-dimethylamino-1-methyl-4-methoxy-8-azaquinolone-2; 7-dimethylamino-4-methylquinolone-2; 7-dimethylamino-4-trifluoromethylcoumarin; 2-(4-(4-dimethylaminophenyl)- 1 ,3-butadienyl)-3-24POLYOQ15-WO-ORD 8ethylbenzothiazolium perchlorate; 2-(6-(p-dimethylaminophenyl)-2,4-neopentylene-1 ,3,5-hexatrienyl)-3- methylbenzothiazolium perchlorate; 2-(4-(p-dimethylaminophenyl)-1 ,3-butadienyl)-1 ,3,3-trimethyl-3H-indolium perchlorate; 3,3'-dimethyloxatricarbocyanine iodide; 2,5-diphenylfuran; 2,5-diphenyloxazole; 4,4'-diphenylstilbene; 1-ethyl-4-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-pyridinium perchlorate; 1-ethyl-2-(4-(p-dimethylaminophenyl)- 1 ,3-butadienyl)-pyridinium perchlorate; 1-ethyl-4-(4-(p-dimethylaminophenyl)- 1 ,3-butadienyl)-quinolium perchlorate; 3-ethylamino-7-ethylimino-2,8-dimethylphenoxazin-5-ium perchlorate; 9-ethylamino-5-ethylamino-10-methyl-5H-benzo(a) phenoxazonium perchlorate; 7-ethylamino-6-methyl-4-trifluoromethylcoumarin; 7-ethylamino-4-trifluoromethylcoumarin; 1,1',3,3,3',3'-hexamethyl-4,4',5,5'-dibenzo-2,2'-indotricarboccyanine iodide; 1,1',3,3,3',3'-hexamethylindodicarbocyanine iodide;1,1',3,3,3',3'-hexamethylindotricarbocyanine iodide; 2-methyl-5-t-butyl-p- quaterphenyl; N-methyl-4-trifluoromethylpiperidino-<3,2-g>coumarin; 3-(2'-N-methylbenzimidazolyl)-7-N,N-diethylaminocoumarin; 2-(1-naphthyl)-5-phenyloxazole; 2,2'-p-phenylen-bis(5-phenyloxazole); 3,5,3"",5""-tetra-t-butyl-p- sexiphenyl; 3, 5, 3"", 5 ""-tetra-t- butyl- p-quinquephenyl; 2, 3, 5, 6-1 H,4H-tetrahydro-9- acetylquinolizino-<9,9a, 1 -gh>coumarin; 2, 3, 5, 6-1 H,4H-tetrahydro-9- carboethoxyquinolizino-<9,9a, 1 -gh> coumarin; 2, 3, 5, 6-1 H,4H-tetrahydro-8- methylquinolizino-<9,9a, l-gh> coumarin; 2,3,5,6-IH,4H-tetrahydro-9-(3-pyridyl)- quinolizino-<9,9a,l-gh> coumarin; 2,3, 5,6-1 H,4H-tetrahydro-8-trifluoromethylquinolizino-<9,9a,l-gh> coumarin; 2,3, 5,6-1 H,4H- tetrahydroquinolizino-<9,9a,l-gh>coumarin; 3,3',2",3'"-tetramethyl-p-quaterphenyl; 2,5,2"",5'"-tetramethyl-p-quinquephenyl; P-terphenyl; P-quaterphenyl; nile red; rhodamine 700; oxazine 750; rhodamine 800; IR 125; IR 144; IR 140; IR 132; IR 26; IR5; diphenylhexatriene; diphenylbutadiene; tetraphenylbutadiene; naphthalene; anthracene; 9,10-diphenylanthracene; pyrene; chrysene; rubrene; coronene; phenanthrene and the like, and combinations comprising at least one of the foregoing dyes.AdditivesThe polymer composition of the present invention may optionally include additives which do not interfere with the previously mentioned desirable properties but enhance other favorable properties.Optional additives that may be compounded or blended into the polymer composition of the invention in customary amounts include lubricants, release agents, UV absorbers, UV stabilizers, anti-oxidants, anti-ozonants, stabilizers, stain-proofing agents, anti-static additives, anti-microbial agents, melt viscosity enhancers, impact modifiers, quenchers,24POLY0015-WO-ORD 9processing aids, and the like. The different additives that can be incorporated in the compositions are commonly used and known to one skilled in the art. Illustrative descriptions of such additives may be found in R. Gachterand H. Muller, Plastics Additives Handbook, 6th edition, 2009.The polymer composition of the present invention may comprise a flame retardant. Suitable flame retardant that may be added are stable, specifically hydrolytically stable. A hydrolytically stable flame retardant does not substantially degrade under conditions of manufacture and / or use to generate species that can catalyze or otherwise contribute to the degradation of the polymer composition. Such flame retardants may be organic compounds that include phosphorus, bromine, and / or chlorine. The polysiloxane-polycarbonate copolymers described above may also be used. Non-brominated and non-chlorinated phosphorus-containing flame retardants may be preferred in certain applications for regulatory reasons, for example certain organic phosphates and / or organic compounds containing phosphorus-nitrogen bonds.Inorganic flame retardants, such as boric acid, boric oxide, or boric esters are also contemplated as effective flame retardants in these systems.Examples of the flame retardant include those described in W02008100327A1, page 38 second full paragraph to page 41, incorporated herein by reference.Anti-drip agents may also be used, for example a fibril forming or non-fibril forming fluoropolymer such as polytetrafluoroethylene (PTFE). The anti-drip agent may be encapsulated by a rigid copolymer as described above, for example SAN. PTFE encapsulated in SAN is known as TSAN. Encapsulated fluoropolymers may be made by polymerizing the encapsulating polymer in the presence of the fluoropolymer, for example an aqueous dispersion. TSAN may provide significant advantages over PTFE, in that TSAN may be more readily dispersed in the composition. A suitable TSAN may comprise, for example, about 50 wt.% PTFE and about 50 wt.% SAN, based on the total weight of the encapsulated fluoropolymer. The SAN may comprise, for example, about 75 wt.% styrene and about 25 wt.% acrylonitrile based on the total weight of the copolymer. Alternatively, the fluoropolymer may be pre- blended in some manner with a second polymer, such as for, example, an aromatic polycarbonate resin or SAN to form an agglomerated material for use as an anti-drip agent. Either method may be used to produce an encapsulated fluoropolymer.24POLYOQ15-WO-ORD 10The amount of the additives may e.g. be 0.0 to 5.0 wt%, for example 0.1 to 1.0 wt% with respect to the total composition.The polymer composition may comprise a further polymer, preferably selected from the group consisting of polyesters other than PET and PBT, polyolefins other than polypropylene, methyl methacrylate / butadiene / styrene copolymer, styrene / butadiene / styrene copolymer (SBS), styrene / ethylene-butylene / styrene copolymer (SEBS), styrene / ethylene-propylene / styrene copolymer (SEPS) styrene / acrylonitrile copolymer (SAN), acrylonitrile / styrene / acrylonitrile copolymer (ASA), unsaturated polyester (UPES), polyamide (PA), thermoplastic urethane (TPU), polystyrene (PS), high impact polystyrene (HIPS), polyvinyl chloride (PVC).The amount of further polymers may e.g. be 1.0 to 40 wt%, for example 1.0 to 10 wt% with respect to the total composition.Preferably, the total amount of the first polymer, carbon black, optional colorants and optional further polymers is at least 95 wt% of the total composition.Preferably, the total amount of the first polymer, carbon black, optional colorants, optional additives and optional further polymers is 100 wt% of the total composition.The invention further provides an article obtained by or obtainable by the method of the invention. The article may be automotive parts, for example interior parts such as instrument panels, overhead consoles, interior trim, center consoles, and other interior parts; and exterior parts such as body panels, exterior trim, bumpers, and others.It is noted that the invention relates to the subject-matter defined in the independent claims alone or in combination with any possible combinations of features described herein, preferred in particular are those combinations of features that are present in the claims. It will therefore be appreciated that all combinations of features relating to the composition according to the invention; all combinations of features relating to the process according to the invention and all combinations of features relating to the composition according to the invention and features relating to the process according to the invention are described herein.It is further noted that the term ‘comprising’ does not exclude the presence of other elements. However, it is also to be understood that a description on a24POLY0015-WO-ORD 11product / composition comprising certain components also discloses a product / composition consisting of these components. The product / composition consisting of these components may be advantageous in that it offers a simpler, more economical process for the preparation of the product / composition. Similarly, it is also to be understood that a description on a process comprising certain steps also discloses a process consisting of these steps. The process consisting of these steps may be advantageous in that it offers a simpler, more economical process.When values are mentioned for a lower limit and an upper limit for a parameter, ranges made by the combinations of the values of the lower limit and the values of the upper limit are also understood to be disclosed.The invention is now elucidated by way of the following examples, without however being limited thereto.Polycarbonate (interfacial homopolymer having a melt volume rate of 28 cm3 / 10 minutes as determined in accordance with ISO 1133 at 300°C and 1.2 kg) and additives (0.05 wt% Irgaphos 168 and 0.4 wt% pentaerythritol tetrastearate, amounts are with respect to the total composition) were molded into samples together with different amounts of carbon black and / or black dye as shown in Tables 1-6. Amounts of carbon black (CB) are in wt% with respect to the total composition. The black dye was produced using a green dye (solvent green 3: 0.17 wt%) and a red dye (solvent red 135: 0.13 wt%).These samples were moulded into two different colour chips: 1) a colour chip with a smooth surface, 2) a colour chip with a grained surface (textured surface). These chips were measured for gloss and colour (CIE L*, a*, b* values). These chips were exposed to UV-C radiation and gloss and colour (CIE L*, a*, b* values) were measured at certain intervals of UV-C radiation. Results are summarized in Tables 1-6.The UV-C radiation was conducted in an irradiation chamber (type BS-02) from Opsytec Dr. Grbbel GmbH, equipped with a UV-MAT Dosimeter system and a UVC sensor. The device uses eight UV-C lamps with a line spectrum at 254 nm (Philips TUV 15W / G15 T8) and reaches a peak UVC intensity of 10 mW / cm2. The UV-C energy received was read from the UV-MAT Dosimeter.24POLYOQ15-WO-ORD 12Table 1 gloss @ 60° on a smooth moulded surfaceIt can be understood from Table 1 that a decreased gloss is obtained at irradiation of UV-C of 12 kJ / cm2compared to the non-irradiated surface for the compositions according to the invention.When the amount of carbon black is too low, a decreased gloss is not obtained or the decrease is small even at irradiation of UV-C of 12 kJ / cm2, see CE2 and CE3.Table 2 gloss @ 60° on a grained moulded surface24POLYOQ15-WO-ORD 13It can be understood from Table 2 that a decreased gloss is obtained at irradiation of UV-C of 12 kJ / cm2compared to the non-irradiated surface for the compositions according to the invention.When the amount of carbon black is too low, a decreased gloss is not obtained or the decrease is small even at irradiation of UV-C of 12 kJ / cm2, see CE9 and CE10.Table 3: colour L* values smooth surfaceTable 4: colour a* values smooth surface24POLYOQ15-WO-ORD 14Table 5: colour b* values smooth surfaceTable 6: L* values grained surface24POLYOQ15-WO-ORD 15Table 7: a* values grained surfaceTable 8: b* values grained surfaceIt can be understood from Tables 3 and 6 that UV-C irradiation results in an increase in the L* value of a smooth surface whereas the L* value of a grained surface does not substantially change.It can be understood from Tables 4 and 7 that UV-C irradiation does not substantially change the a* value both for a smooth surface or a grained surface.It can be understood from Tables 5 and 8 that UV-C irradiation results in a decrease in the b* value, i.e. a shift to blue appearance, both for both for a smooth surface or a grained surface.

Claims

24POLY0015-WO-ORD 16CLAIMS1. Method for the manufacture of an article comprising the steps ofi) moulding a polymer composition comprising a first polymer selected from the group consisting of polycarbonate, polycarbonate-polyorganosiloxane copolymer, polycarbonate-polyester copolymer, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile / butadiene / styrene copolymer (ABS), polypropylene and polycyclohexylene dimethylene terephthalate (PCTG) and combinations thereof and carbon black into an article having a first surface having a first gloss at 60° measured according to ASTM D2457 andii) exposing the first surface to radiation having a wavelength in the range of from 10 - 300nm, preferably from 100 - 280 nm, to obtain a second, exposed surface part having a second gloss at 60° measured according to ASTM D2457 which is lower than the first gloss.

2. The method of claim 1 , wherein the first polymer is polycarbonate or the first polymer is polycarbonate and one or more polymers selected from the group consisting of polycarbonate-polyorganosiloxane copolymer, polycarbonatepolyester copolymer, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), acrylonitrile / butadiene / styrene copolymer (ABS), polypropylene and polycyclohexylene dimethylene terephthalate (PCTG).

3. The method of any one or more of the preceding claims, wherein the amount of carbon black is at least 0.005 wt.%, for example 0.005 to 30 wt.%, based on the weight of the composition.

4. The method of any one or more of the preceding claims, wherein the amount of carbon black is at least 0.01 wt.%, preferably is 0.05 to 25 wt%, 0.10 to 20 wt%, 0.20 to 10 wt%, 0.30 to 5.0 wt%, 0.4 to 3.0 wt% or 0.5 to 2.0 wt%, based on the weight of the composition.

5. The method of any one or more of the preceding claims, wherein the composition comprises a further colorant, for example inorganic pigments and / or organic pigments and / or organic dyes.24POLYOQ15-WO-ORD 176. The method of claim 5, wherein the amount of the further colorants is 0.005 to 10 wt%, 0.05 to 8.0 wt%, 0.10 to 6.0 wt%, 0.30 to 5.0 wt%, 0.4 to 3.0 wt% or 0.5 to 2.0 wt%, based on the weight of the composition.

7. The method of any one or more of the preceding claims, wherein the composition does not comprise organic pigments or organic dyes or comprises organic pigments or organic dyes in an amount of less than 0.005 wt%, less than 0.003 wt% or less than 0.001 wt%, based on the weight of the composition.

8. The method of any one or more of the preceding claims, wherein the composition comprises a further polymer preferably selected from the group consisting of polyesters other than PET and PBT, polyolefins other than polypropylene, methyl methacrylate / butadiene / styrene copolymer (MBS), styrene / butadiene / styrene copolymer (SBS), styrene / ethylene-butylene / styrene copolymer (SEBS), styrene / ethylene-propylene / styrene copolymer (SEPS), styrene / acrylonitrile copolymer (SAN), acrylonitrile / styrene / acrylonitrile copolymer (ASA), unsaturated polyester (UPES), polyamide (PA), thermoplastic urethane (TPU), polystyrene (PS), high impact polystyrene (HIPS), polyvinyl chloride (PVC).

9. The method of any one or more of the preceding claims, wherein said exposing is carried out with a UV-C light source.

10. The method of any one or more of the preceding claims, wherein the total amount of energy to which the first surface is exposed is from 0.5 to 20 kJ / cm2, preferably 2 to 20 kJ / cm2.

11. The method of any one or more of the preceding claims, wherein the second, exposed surface of the article has a second gloss of at most 90% relative to the first gloss, more preferably the second gloss is at most 75%, at most 70%, at most 50% or at most 25% of the first gloss.

12. The method of any one or more of the preceding claims, wherein the second gloss is at most 60, at most 50, at most 40, at most 30, at most 20 or at most 10.

13. The method of any one or more of claims 1-12, wherein the first gloss is at least 50, for example at least 60.24POLYOQ15-WO-ORD 1814. The method of any one or more of claims 1-12, wherein the first gloss is less than 50, for example at most 40.

15. Article obtained or obtainable by the method of any one or more of the preceding claims.

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