Chemically resistant polycarbonate compositions and articles made therefrom

Abstract

A polycarbonate composition comprising specific amounts of a linear polycarbonate, a first poly (carbonate-siloxane) copolymer, a second poly (carbonate-siloxane) copolymer, and optionally one or more of a branched polycarbonate, a highly branched polycarbonate, or a second linear polycarbonate. A method for preparing the composition is also disclosed. The composition can be used in particular for the preparation of various articles, in particular thin-walled articles, for applications requiring high chemical resistance.

Description

[0001] Citation of Related Applications

[0002] This application claims priority to European Patent Application No. 22207871.9, filed on November 16, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to polycarbonate compositions, and more particularly to transparent, chemical-resistant polycarbonate compositions, methods for their manufacture, and their uses. Background Art

[0004] Polycarbonates can be used to manufacture articles and components for a wide range of applications, from automotive parts to electronic devices. Due to their wide use, it is desirable to provide polycarbonates that are chemical-resistant when molded into transparent articles with thin walls.

[0005] Accordingly, there is still a need in the art for polycarbonate compositions that are chemical-resistant and provide transparency. Summary of the Invention

[0006] A polycarbonate composition comprising: 35 to 94 weight percent of a linear polycarbonate; 5 to 20 weight percent of a first poly(carbonate-siloxane) copolymer having a siloxane content of 4 to 15 weight percent based on the total weight of the first poly(carbonate-siloxane) copolymer; and 1 to 6 weight percent of a second poly(carbonate-siloxane) copolymer having a siloxane content of 35 to 60 weight percent based on the total weight of the second poly(carbonate-siloxane) copolymer; wherein the weight percent of each component is based on the total weight of the composition; wherein the polycarbonate composition has a total siloxane content of less than 2.5 weight percent based on the total weight of the composition; and wherein the composition comprises less than 1 weight percent of a flame retardant having a phosphorus-nitrogen bond.

[0007] A method of manufacturing a polycarbonate composition, comprising melt-mixing the components of the composition.

[0008] An article comprising a polycarbonate composition represents another aspect of the present disclosure.

[0009] The above and other features are illustrated by the following detailed description. Detailed Description

[0010] Due to the miniaturization of electronic components and market trends, there is a need for transparent, chemically resistant articles with good processability (i.e., ductility). Branched polycarbonates can be added to impart the desired properties, but molded articles prepared from branched polycarbonates can be brittle and lack ductility. Poly( carbonate-siloxane) copolymers can be added to improve the impact resistance of branched thermoplastic compositions, but it can be challenging to determine combinations of poly( carbonate-siloxane) copolymers that improve the ductility of the composition without sacrificing transparency. Achieving good chemical resistance can add further challenges to providing a composition that can exhibit a good balance of the above properties.

[0011] The inventors have unexpectedly found that a composition comprising a specific amount of linear polycarbonate, a first poly( carbonate-siloxane) copolymer having a siloxane content of 4 wt% to 15 wt%, a second poly( carbonate-siloxane) copolymer having a siloxane content of 35 wt% to 60 wt%, and optionally one or more of a branched polycarbonate, a highly branched polycarbonate, or a second linear polycarbonate can provide a desired combination of chemical resistance, transparency, and mechanical properties.

[0012] Accordingly, polycarbonate compositions represent one aspect of the present disclosure. The polycarbonate compositions comprise linear polycarbonate. As used herein, "polycarbonate" refers to a polymer having carbonate units with a repeating structure of formula (1):

[0013]

[0014] wherein at least 60% of the total number of R 1 groups contain an aromatic moiety, and the remaining amount is aliphatic, alicyclic, or aromatic. In one aspect, each R 1 is a C 6-30 aromatic group, i.e., containing at least one aromatic moiety. R 1 can be derived from HO-R 1 -OH, particularly an aromatic dihydroxy compound of formula (2):

[0015] HO–A 1 –Y 1 –A 2 –OH(2)

[0016] wherein A 1 and A 2 are each a monocyclic divalent aromatic group, and Y 1 is a single bond or a bridging group having one or more atoms separating A 1 from A 2 . In one aspect, one atom separates A 1 from A2 Separate. Preferably, each R 1 can be derived from a bisphenol of formula (3):

[0017]

[0018] wherein, R a and R b are each independently halogen, C 1-12 alkoxy or C 1-12 alkyl, and p and q are each independently integers from 0 to 4. It should be understood that when p or q is less than 4, the valence of each carbon of the ring is filled with hydrogen. Also in formula (3), X a is a bridging group connecting two hydroxy-substituted aromatic groups, wherein the bridging group and the hydroxy substituents of each C 6 arylene are arranged ortho, meta or para (preferably para) to each other on the C 6 arylene. In one aspect, the bridging group X a is a single bond, -O-, -S-, -S(O)-, -S(O) 2 2-, -C(O)- or C 1-60 organic group. The organic bridging group can be cyclic or acyclic, aromatic or non-aromatic, and can further contain heteroatoms such as halogen, oxygen, nitrogen, sulfur, silicon or phosphorus. The C 1-60 organic group can be arranged such that the C 6 arylene attached thereto are each attached to a common alkylidene carbon atom or to different carbon atoms of the C 1-60 organic bridging group. In one aspect, p and q are each 1, and R a and R b are each C 1-3 alkyl, preferably methyl, arranged meta to the hydroxy groups on each arylene.

[0019] In one aspect, X a is C 3-18 cycloalkylidene, a C c alkylidene of the formula –C(R d )(R 1-25 )–, wherein R c and R d are each independently hydrogen, C 1-12 alkyl, C 1-12 cycloalkyl, C 7-12 arylalkyl, C 1-12 heteroalkyl or cyclic C 7-12 heteroarylalkyl, or a group having the formula –C(=R e )–, wherein R e is a divalent C 1-12Hydrocarbyl groups. These types of groups include methylene, cyclohexylmethylene, ethylidene, neopentylidene, and isopropylidene, as well as 2-[2.2.1]-bicycloheptylidene, cyclohexylidene, 3,3-dimethyl-5-methylcyclohexylidene, cyclopentylidene, cyclododecylidene, and adamantylidene.

[0020] In another aspect, X a is a C 1-18 alkylene, C 3-18 cycloalkylene, fused C 6-18 cycloalkylene or a group of the formula –J 1 –G–J 2 –, where J 1 and J 2 are the same or different C 1-6 alkylene, and G is a C 3-12 cycloalkylidene or C 6-16 arylene.

[0021] For example, X a can be a substituted C 3-18 cycloalkylidene of formula (4):

[0022]

[0023] wherein, R r , R p , R q and R t are each independently hydrogen, halogen, oxygen or C 1-12 hydrocarbyl; Q is a direct bond, carbon, or divalent oxygen, sulfur, or –N(Z)–, where Z is hydrogen, halogen, hydroxy, C 1-12 alkyl, C 1-12 alkoxy, C 6-12 aryl or C 1-12 acyl; r is from 0 to 2, t is 1 or 2, q is 0 or 1, and k is ≥0 to 3, provided that at least two of R r , R p , R q and R t together form a fused alicyclic, aromatic or heteroaromatic ring. It should be understood that when the fused ring is aromatic, the ring shown in formula (4) will have unsaturated carbon-carbon bonds where the rings are fused. When k is 1 and q is 0, the ring shown in formula (4) contains 4 carbon atoms, when k is 2, the ring shown in formula (4) contains 5 carbon atoms, and when k is 3, the ring contains 6 carbon atoms. In one aspect, two adjacent groups (e.g., R q and R t together) form an aromatic group, and in another aspect, R q and R tTogether form an aromatic group, and R r and R p together form a second aromatic group. When R q and R t together form an aromatic group, R p can be a double bond oxygen, i.e., a ketone, or Q can be –N(Z)–, where Z is a phenyl group.

[0024] Bisphenol, where X a is a cycloalkanediyl group of formula (4), can be used to prepare a polycarbonate containing a benzopyrrolone carbonate unit of formula (5a):

[0025]

[0026] wherein, R a 、R b 、p and q are defined as in formula (3), R 3 are each independently a C 1-6 alkyl group, j is from 0 to 4, and R 4 is hydrogen, a C 1-6 alkyl group or a substituted or unsubstituted phenyl group, such as a phenyl group substituted by up to 5 C 1-6 alkyl groups. For example, the benzopyrrolone carbonate unit has the formula (5b):

[0027]

[0028] wherein, R 5 is hydrogen, an optionally phenyl group substituted by up to five C 1-6 alkyl groups or C 1-4 alkyl groups. In one aspect, in formula (5b), R 5 is hydrogen, methyl or phenyl, preferably phenyl. The carbonate unit (5b), where R 5 is phenyl can be derived from 2-phenyl-3,3'-bis(4-hydroxyphenyl)benzopyrrolone (also known as 3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-1-one, or N-phenylphthalein bisphenol (“PPPBP”)).

[0029] Other bisphenol carbonate repeating units of this type are the isatin carbonate units of formula (5c) and (5d):

[0030]

[0031] wherein, R a and R b are each independently a halogen, a C 1-12 alkoxy group or a C 1-12 alkyl group, p and q are each independently from 0 to 4, and R i is a C1-12 alkyl, optionally substituted phenyl having 1 to 5 C 1-10 alkyl groups, or optionally substituted benzyl having 1 to 5 C 1-10 alkyl groups. In one aspect, R a and R b are each methyl, p and q are each independently 0 or 1, and R i is C 1-4 alkyl or phenyl.

[0032] Other examples of bisphenol carbonate units derived from bisphenol (3), where X a is a substituted or unsubstituted C 3-18 cycloalkanediyl, including the cyclohexylidene-bridged bisphenol of formula (5e):

[0033]

[0034] wherein, R a and R b are each independently C 1-12 alkyl, R g is C 1-12 alkyl, p and q are each independently 0 to 4, and t is 0 to 10. In a specific aspect, at least one of each R a and R b is arranged at the meta-position of the cyclohexylidene bridging group. In one aspect, R a and R b are each independently C 1-4 alkyl, R g is C 1-4 alkyl, p and q are each 0 or 1, and t is 0 to 5. In another specific aspect, R a , R b and R g are each methyl, p and q are each 0 or 1, and t is 0 or 3, preferably 0. In yet another aspect, p and q are each 0, each R g is methyl, and t is 3, such that X a is 3,3-dimethyl-5-methylcyclohexylidene.

[0035] Other examples of bisphenol carbonate units derived from bisphenol (3), where X a is a substituted or unsubstituted C 3-18 cycloalkanediyl, including the adamantyl unit of formula (5f) and the fluorenyl unit of formula (5g)

[0036]

[0037] wherein, R a and R b are each independently C1-12 an alkyl group, and p and q are each independently 1 to 4. In a specific aspect, each R a and R b at least one of which is disposed at the meta position of the cycloalkanediyl bridging group. In one aspect, R a and R b are each independently C 1-3 alkyl, and p and q are each 0 or 1; preferably, R a and R b are each methyl, p and q are each 0 or 1, and when p and q are 1, the methyl groups are disposed at the meta position of the cycloalkanediyl bridging group. The carbonate containing units (1a) to (1g) can be used to manufacture polycarbonates having a high glass transition temperature (Tg) and a high heat distortion temperature.

[0038] Other useful dihydroxy compounds of the formula HO-R 1 -OH include aromatic dihydroxy compounds of the formula (6):

[0039]

[0040] wherein each R h is independently a halogen atom, a C 1-10 hydrocarbon group such as C 1-10 alkyl, a halogen-substituted C 1-10 alkyl, a C 6-10 aryl or a halogen-substituted C 6-10 aryl, and n is 0 to 4. The halogen is usually bromine.

[0041] Some illustrative examples of specific dihydroxy compounds include the following: 4,4'-dihydroxybiphenyl, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)-1-naphthylmethane, 1,2-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 1,1-bis(hydroxyphenyl)cyclopentane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 1,1-bis(4-hydroxyphenyl)isobutene, 1,1-bis(4-hydroxyphenyl)cyclododecane, trans-2,3-bis(4-hydroxyphenyl)-2-butene, 2,2-bis(4-hydroxyphenyl)adamantane, α,α'-bis(4-hydroxyphenyl)toluene, bis(4-hydroxyphenyl)acetonitrile, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4-hydroxyphenyl)propane, 2,2-bis(3-n-propyl-4-hydroxyphenyl)propane, 2,2-bis(3-isopropyl-4-hydroxyphenyl)propane, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4-hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethylene, 1,1-dibromo-2,2-bis(4-hydroxyphenyl)ethylene, 1,1-dichloro-2,2-bis(5-phenoxy-4-hydroxyphenyl)ethylene, 4,4'-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone, 1,6-bis(4-hydroxyphenyl)-1,6-hexanedione, ethylene glycol bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorene, 2,7-dihydroxypyrene, 6,6'-dihydroxy-3,3,3',3'-tetramethylspiro(bis)indane ("spirobiindane bisphenol"), 3,3-bis(4-hydroxyphenyl)phthalimide, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene, 2,7-dihydroxyphenothiazine, 2,7-dihydroxy-9,10-dimethylphenazine, 3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and 2,7-dihydroxycarbazole, resorcinol, substituted resorcinol compounds such as 5-methylresorcinol, 5-ethylresorcinol, 5-propylresorcinol, 5-butylresorcinol, 5-tert-butylresorcinol, 5-phenylresorcinol, 5-cumylresorcinol, 2,4,5,6-tetrafluororesorcinol, 2,4,5,6 - tetrabromoresorcinol, etc.; catechol; hydroquinone; substituted hydroquinones such as 2 - methylhydroquinone, 2 - ethylhydroquinone, 2 - propylhydroquinone, 2 - butylhydroquinone, 2 - tert - butylhydroquinone, 2 - phenylhydroquinone, 2 - cumylhydroquinone, 2,3,5,6 - tetramethylhydroquinone, 2,3,5,6 - tetra - tert - butylhydroquinone, 2,3,5,6 - tetrafluorohydroquinone, 2,3,5,6 - tetrabromohydroquinone, etc., or combinations thereof.,

[0042] Specific examples of the bisphenol compound of formula (3) include 1,1 - bis(4 - hydroxyphenyl)methane, 1,1 - bis(4 - hydroxyphenyl)ethane, 2,2 - bis(4 - hydroxyphenyl)propane (hereinafter "bisphenol A" or "BPA"), 2,2 - bis(4 - hydroxyphenyl)butane, 2,2 - bis(4 - hydroxyphenyl)octane, 1,1 - bis(4 - hydroxyphenyl)propane, 1,1 - bis(4 - hydroxyphenyl)n - butane, 2,2 - bis(4 - hydroxy - 2 - methylphenyl)propane, 1,1 - bis(4 - hydroxy - tert - butylphenyl)propane, 3,3 - bis(4 - hydroxyphenyl)benzopyrrolone, 2 - phenyl - 3,3 - bis(4 - hydroxyphenyl)benzopyrrolone (PPPBP), and 1,1 - bis(4 - hydroxy - 3 - methylphenyl)cyclohexane (DMBPC). Combinations can also be used. In a specific aspect, the polycarbonate is a linear homopolymer derived from bisphenol A, where each A in formula (3) 1 and A 2 is a p - phenylene group and Y 1 is an isopropylidene group.,

[0043] The linear polycarbonate can include bisphenol A polycarbonate homopolymer, also known as bisphenol A homopolycarbonate. The bisphenol A polycarbonate homopolymer has carbonate units with a repeating structure of formula (7).

[0044]

[0045] The polycarbonate can be prepared by known methods such as interfacial polymerization and melt polymerization, which are known and described, for example, in WO 2013 / 175448 A1 and WO 2014 / 072923 A1. A capping agent (also known as a chain terminator or chain ender) can be included during polymerization to provide end groups, such as monocyclic phenols like phenol, p - cyanophenol, and C 1-22 alkyl - substituted phenols such as p - cumylphenol, resorcinol monobenzoate, and p - butylphenol and tert - butylphenol, mono - ethers of dihydric phenols such as p - methoxyphenol, mono - esters of dihydric phenols such as resorcinol monobenzoate, functionalized chlorides of aliphatic monocarboxylic acids such as acryloyl chloride and methacryloyl chloride, and monochloroformates such as phenyl chloroformate, alkyl - substituted phenyl chloroformate, p - cumylphenyl chloroformate, and tolyl chloroformate. Combinations of different end groups can be used.,

[0046] The polycarbonate may have an intrinsic viscosity of 0.3 to 1.5 deciliters per gram (dl / gm), preferably 0.45 to 1.0 dl / gm, as measured in chloroform at 25°C. The polycarbonate may have a weight average molecular weight (Mw) of 10,000 to 200,000 grams per mole (g / mol), preferably 20,000 to 100,000 g / mol, as determined by gel permeation chromatography (GPC) using a crosslinked styrene-divinylbenzene column according to polycarbonate standards. The GPC sample is prepared at a concentration of 1 mg / ml and eluted at a flow rate of 1.5 ml / minute.

[0047] In one aspect, the linear polycarbonate may have a weight average molecular weight of 15,000 to less than 34,000 grams per mole, or 25,000 to 33,000 grams per mole, or 30,000 to 33,000 grams per mole, as determined by gel permeation chromatography (GPC) using a crosslinked styrene-divinylbenzene column according to polycarbonate standards. In one aspect, the linear polycarbonate may be a linear bisphenol A homopolycarbonate having a weight average molecular weight of 15,000 to less than 34,000 grams per mole, 25,000 to 33,000 grams per mole or 30,000 to 33,000 grams per mole, as measured by gel permeation chromatography (GPC) using a crosslinked styrene-divinylbenzene column according to polycarbonate standards.

[0048] Based on the total weight of the polycarbonate composition, the linear polycarbonate may be present in the composition in an amount of 35 to 94 weight percent. Within this range, each based on the total weight of the polycarbonate composition, the linear polycarbonate may be present in an amount of at least 38 weight percent, or at least 40 weight percent, or at least 45 weight percent, or at least 50 weight percent, or at least 60 weight percent, or at least 70 weight percent, or at least 75 weight percent, or at least 79 weight percent. Also within this range, each based on the total weight of the polycarbonate composition, the linear polycarbonate may be present in an amount of at most 90 weight percent, or at most 89 weight percent, or at most 74 weight percent, or at most 65 weight percent, or at most 54 weight percent. For example, in one aspect, the linear polycarbonate may be present in the composition in an amount of 79 to 89 weight percent. In one aspect, the linear polycarbonate may be present in the composition in an amount of 40 to 74 weight percent. In one aspect, the linear polycarbonate may be present in the composition in an amount of 40 to 54 weight percent.

[0049] The polycarbonate composition further comprises a combination of poly(carbonate-siloxane) copolymers. The poly(carbonate-siloxane) copolymer comprises carbonate repeating units as defined above and a polysiloxane block. The polysiloxane block of the poly(carbonate-siloxane) comprises repeating diorganosiloxane units of formula (8)

[0050]

[0051] wherein each R is independently a C 1-13 monovalent organic group. For example, R can be a C 1-13 alkyl group, a C 1-13 alkoxy group, a C 2-13 alkenyl group, a C 2-13 alkenyloxy group, a C 3-6 cycloalkyl group, a C 3-6 cycloalkoxy group, a C 6-14 aryl group, a C 6-10 aryloxy group, a C 7-13 arylenealkyl group, a C 7-13 arylalkenyloxy group, a C 7-13 alkylarylene group or a C 7-13 alkylaryloxy group. The foregoing groups can be fully or partially halogenated with fluorine, chlorine, bromine, or iodine, or combinations thereof. In one aspect, when a transparent poly(carbonate-siloxane) is desired, R is not substituted with halogen. Combinations of the foregoing R groups can be used in the same copolymer.

[0052] The value of E in formula (8) can vary widely depending on the type and relative amounts of each component in the thermoplastic composition, the desired properties of the composition, and like considerations. Generally, E has an average value of from 2 to 1,000, preferably from 2 to 500, from 2 to 200, or from 2 to 125, from 5 to 80, or from 10 to 70. In one aspect, E has an average value of from 10 to 80 or from 10 to 40, and in yet another aspect, E has an average value of from 40 to 80, or from 40 to 70. When E has a lower value, such as less than 40, it may be desirable to use a relatively large amount of the poly(carbonate-siloxane) copolymer. Conversely, when E has a higher value, such as greater than 40, a relatively lower amount of the poly(carbonate-siloxane) copolymer can be used. Combinations of first and second (or more) poly(carbonate-siloxane) copolymers can be used, wherein the average value of E of the first copolymer is less than the average value of E of the second copolymer.

[0053] In one aspect, the polysiloxane block has the formula (9):

[0054]

[0055] wherein, E and R are as defined in formula (8); each R can be the same or different and is as defined above; and Ar can be the same or different and is a substituted or unsubstituted C 6-30 arylene, wherein the bond is directly connected to the aromatic moiety. The Ar groups in formula (9) can be derived from C 6-30 dihydroxyarylene compounds such as the dihydroxyarylene compounds of formula (3) or (6). Dihydroxyarylene compounds are 1,1-bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, 1,1-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)n-butane, 2,2-bis(4-hydroxy-1-methylphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)sulfide, and 1,1-bis(4-hydroxy-tert-butylphenyl)propane.

[0056] In another aspect, the polysiloxane block has the formula (10):

[0057]

[0058] wherein, R and E are as described above, and each R 5 is independently a divalent C 1-30 organic group, and wherein the polymerized polysiloxane units are the reaction residues of their corresponding dihydroxy compounds. In a specific aspect, the polysiloxane block is of the formula (11):

[0059]

[0060] wherein, R and E are as defined above. The R in formula (11) 6 is a divalent C 2-8 aliphatic group. Each M in formula (14) can be the same or different and can be a halogen, cyano, nitro, C 1-8 alkylthio, C 1-8 alkyl, C 1-8 alkoxy, C 2-8 alkenyl, C 2-8 alkenyloxy, C 3-8 cycloalkyl, C 3-8 cycloalkoxy, C 6-10 aryl, C 6-10 aryloxy, C 7-12 aralkyl, C 7-12 aralkoxy, C 7-12 alkaryl or C 7-12 alkaryloxy, where each n is independently 0, 1, 2, 3, or 4.

[0061] In one aspect, M is bromine or chlorine, an alkyl group such as methyl, ethyl or propyl, an alkoxy group such as methoxy, ethoxy or propoxy, or an aryl group such as phenyl, chlorophenyl or tolyl; R 6 is dimethylene, trimethylene or tetramethylene; and R is C 1-8 alkyl, haloalkyl such as trifluoropropyl, cyanoalkyl, or an aryl group such as phenyl, chlorophenyl or tolyl. In another aspect, R is methyl, or a combination of methyl with trifluoropropyl, or a combination of methyl with phenyl. In yet another aspect, R is methyl, M is methoxy, n is 1, and R 6 is a divalent C 1-3 aliphatic group. Specific polysiloxane blocks are of the formula:

[0062]

[0063] or combinations thereof, where E has an average value of from 2 to 200, from 2 to 125, from 5 to 125, from 5 to 100, from 5 to 50, from 20 to 80 or from 5 to 20.

[0064] The block of formula (11) can be derived from the corresponding dihydroxy polysiloxane, which in turn can be prepared to effect platinum-catalyzed addition between a siloxane hydride and an aliphatic unsaturated monophenol (such as eugenol, 2-alkylphenol, 4-allyl-2-methylphenol, 4-allyl-2-phenylphenol, 4-allyl-2-bromophenol, 4-allyl-2-tert-butoxyphenol, 4-phenyl-2-phenylphenol, 2-methyl-4-propylphenol, 2-allyl-4,6-dimethylphenol, 2-allyl-4-bromo-6-methylphenol, 2-allyl-6-methoxy-4-methylphenol and 2-allyl-4,6-dimethylphenol). A poly(carbonate-siloxane) copolymer can then be manufactured, for example, by the synthetic procedure of Preparation 2 on page 5 of European Patent Application Publication No. 0524731A1 by Hoover.

[0065] The transparent poly(carbonate-siloxane) copolymer contains carbonate units (1) derived from bisphenol A and repeating siloxane units (11a), (11b), (11c) or combinations thereof (preferably of formula 11a), where E has an average value of from 4 to 50, from 4 to 15, preferably from 5 to 15, more preferably from 6 to 15, and still more preferably from 7 to 10. The transparent copolymer can be manufactured using one or two tubular reactor processes described in U.S. Patent Application No. 2004 / 0039145A1, or the poly(carbonate-siloxane) copolymer can be synthesized using the process described in U.S. Patent No. 6,723,864.

[0066] A combination of a first and a second poly(carbonate-siloxane) copolymer is included in a thermoplastic composition. Based on the total weight of the first poly(carbonate-siloxane), the first poly(carbonate-siloxane) has a siloxane content of 4 wt% to 15 wt%. Within this range, the first poly(carbonate-siloxane) copolymer can have a siloxane content of 4 wt% to 10 wt%. As used herein, the "siloxane content" of a poly(carbonate-siloxane) refers to the content of siloxane units based on the total weight of the poly(carbonate-siloxane). Based on the total weight of the second poly(carbonate-siloxane), the second poly(carbonate-siloxane) has a siloxane content of 35 wt% to 60 wt%. Within this range, the second poly(carbonate-siloxane) can have a siloxane content of 35 - 55 wt% or 35 - 45 wt%.

[0067] The first poly(carbonate-siloxane) can have a weight-average molecular weight of 17,000 to 25,000 g / mol, preferably 19,000 to 25,000 g / mol, as determined by GPC using a crosslinked styrene-divinylbenzene column at a sample concentration of 1 mg / mL according to polycarbonate standards.

[0068] The second poly(carbonate-siloxane) can have a weight-average molecular weight of 2,000 to 100,000 grams per mole (g / mol), preferably 5,000 to 50,000 g / mol, as determined by GPC using a crosslinked styrene-divinylbenzene column at a sample concentration of 1 mg / mL according to polycarbonate standards. In one aspect, the second poly(carbonate-siloxane) can have a weight-average molecular weight of at least 25,000 g / mol, preferably 27,000 g / mol. Within this range, the second poly(carbonate-siloxane) can have a weight-average molecular weight of 25,000 to 100,000 g / mol, or 25,000 to 50,000 g / mol, or 30,000 to 40,000 g / mol.

[0069] The poly(carbonate-siloxane) can have a melt volume flow rate of 1 to 50 cubic centimeters per 10 minutes (cc / 10 min), preferably 2 to 30 cc / 10 min, as measured at 300 °C / 1.2 kg. Combinations of poly(carbonate-siloxanes) with different flow properties can be used to achieve the overall desired flow properties.

[0070] The combination of poly(carbonate-siloxanes) can be present in the composition in an amount that provides a total siloxane content of less than 2.5 wt%, or less than 2.2 wt%, or less than 2 wt%, or less than 1.9 wt%, or less than 1.8 wt%, or less than 1.75 wt%, each based on the total weight of the polycarbonate composition.

[0071] In one aspect, the ratio of the silicone content provided to the composition by the first poly(carbonate-siloxane) copolymer to the silicone content provided to the composition by the second poly(carbonate-siloxane) copolymer can be from 0.9:1 to 1:0.9, or from 0.95:1 to 1:0.95, or from 0.95:1 to 1:1.

[0072] Based on the total weight of the composition, the first poly(carbonate-siloxane) copolymer can be present in the composition in an amount of 5 to 20 weight percent. Within this range, based on the total weight of the composition, the first poly(carbonate-siloxane) copolymer can be present in an amount of 8 to 16 weight percent, or 10 to 16 weight percent, or 11 to 14 weight percent.

[0073] Based on the total weight of the composition, the second poly(carbonate-siloxane) copolymer can be present in the composition in an amount of 1 to 6 weight percent. Within this range, based on the total weight of the composition, the second poly(carbonate-siloxane) copolymer can be present in an amount of 1 to 5 weight percent, or 1 to 4 weight percent, or 1 to 3 weight percent.

[0074] The polycarbonate composition can optionally further comprise a branched polycarbonate or a highly branched polycarbonate or both. As used herein, the term "highly branched polycarbonate" refers to a polycarbonate having 1.5 to 5.0 mole percent branching. The term "branched polycarbonate" refers to a polycarbonate having 0.1 to 1.0 mole percent branching.

[0075] During the polymerization process, branched polycarbonate blocks can be prepared by adding a branching agent. These branching agents include polyfunctional organic compounds that contain at least three functional groups selected from the group consisting of hydroxyl, carboxyl, carboxylic anhydride, halocarbonyl, and mixtures of the above functional groups. Specific examples include trimellitic acid, trimellitic anhydride, triphenol TC (1,3,5-tris((p-hydroxyphenyl)isopropyl)benzene), triphenol PA (4(4(1,1-bis(p-hydroxyphenyl)-ethyl)α,α-dimethylbenzyl)phenol), 4-chlorocarbonyl phthalic anhydride, benzene-1,2,4-tricarboxylic acid, and benzophenone tetracarboxylic acid. Combinations including linear polycarbonates and branched polycarbonates can be used.

[0076] In one aspect, certain types of branching agents can be used to produce branched polycarbonate materials. These branched polycarbonate materials statistically have more than two end groups. The branching agent can be added in an amount (relative to the bisphenol monomer) sufficient to achieve the desired degree of branching (i.e., more than two end groups). The molecular weight of the polymer can become very high when the branching agent is added, and in order to avoid excessive viscosity during the polymerization process, an increased amount of chain terminator can be used relative to the amount used when no specific branching agent is present. The amount of chain terminator used is typically higher than 5 mol% and less than 20 mol% compared to the bisphenol monomer.

[0077] Such branching agents include aromatic triacyl halides, such as the triacyl chloride of formula (12):

[0078]

[0079] wherein Z is halogen, C 1-3 alkyl, C 1-3 alkoxy, C 7-12 arylenealkyl, C 7-12 alkylarylene or nitro, and z is from 0 to 3; the trisubstituted phenol of formula (13)

[0080]

[0081] wherein T is C 1-20 alkyl, C 1-20 alkoxy, C 7-12 aralkyl or C 7-12 alkylaryl, Y is halogen, C 1-3 alkyl, C 1-3 alkoxy, C 7-12 aralkyl, C 7-12 alkylaryl or nitro, and s is from 0 to 4; or the compound of formula (14) (isatin-bisphenol).

[0082]

[0083] Examples of specific branching agents that are particularly effective in the composition include trimellitic trichloride (TMTC), tris-p-hydroxyphenylethane (THPE), and isatin-bisphenol.

[0084] The amount of branching agent used in the preparation of the polymer will depend on many considerations, such as the type of R 1 group, the amount of chain terminator (e.g., cyanophenol), and the desired molecular weight of the polycarbonate. Generally, the amount of branching agent is effective to provide from 0.1 to 10 branching units per 100 R 1 units, preferably from 0.5 to 8 branching units per 100 R 1 units, and more preferably from 0.5 to 8 branching units per 100 R 10.75 to 5 branching units per 100 R units. For a branching agent having formula (20), the branching agent is present in an amount to provide 0.1 to 10 triester branching units per 100 R units, preferably 0.5 to 8, and more preferably 0.75 to 5 triester branching units per 100 R units. For a branching agent having formula (14), the branching agent is present in an amount effective to provide 0.1 to 10 triphenyl carbonate branching units per 100 R units, preferably 0.5 to 8, and more preferably 2.5 to 3.5 triphenyl carbonate units per 100 R units. 1 0.1 to 10 triester branching units per 100 R units, preferably 1 0.5 to 8, and more preferably 1 0.75 to 5 triester branching units per 100 R units. For a branching agent having formula (14), the branching agent is present in an amount effective to provide 1 0.1 to 10 triphenyl carbonate branching units per 100 R units, preferably 1 0.5 to 8, and more preferably 1 2.5 to 3.5 triphenyl carbonate units per 100 R units.

[0085] In one aspect, based on the total moles of the polycarbonate, a highly branched polycarbonate containing the units as described above and containing 1.5 - 5 mol% branching contains greater than or equal to 3 mol% of the moiety derived from the branching agent; and a functional group derived from a capping agent having a pKa between 8.3 and 11. The branching agent can include trimellitic acid chloride, 1,1,1-tris(4-hydroxyphenyl)ethane, or a combination of trimellitic acid chloride and 1,1,1-tris(4-hydroxyphenyl)ethane, and the capping agent is phenol or a phenol having a substituent including a cyano group, an aliphatic group, an olefinic group, an aromatic group, a halogen, an ester group, an ether group, or a combination thereof. In a specific aspect, the capping agent is phenol, p-tert-butylphenol, p-methoxyphenol, p-cyanophenol, p-cumylphenol, or a combination thereof.

[0086] In one aspect, based on the total moles of the polycarbonate, a branched polycarbonate containing the units as described above and containing 0.1 to 1.0 mol% branching contains less than 0.5 mol% of the moiety derived from the branching agent; and a functional group derived from a capping agent having a pKa between 8.3 and 11. The branching agent can include trimellitic acid chloride, 1,1,1-tris(4-hydroxyphenyl)ethane, or a combination of trimellitic acid chloride and 1,1,1-tris(4-hydroxyphenyl)ethane, and the capping agent is phenol or a phenol having a substituent including a cyano group, an aliphatic group, an olefinic group, an aromatic group, a halogen, an ester group, an ether group, or a combination thereof. In a specific aspect, the capping agent is phenol, p-tert-butylphenol, p-methoxyphenol, p-cyanophenol, p-cumylphenol, or a combination thereof.

[0087] When present, based on the total weight of the composition, the branched and highly branched polycarbonates can each independently be included in the composition in an amount of 5 to 50 weight percent. Within this range, each based on the total weight of the composition, the branched and highly branched polycarbonates can each independently be included in the composition in an amount of at least 10 weight percent, or at least 12 weight percent, or at least 15 weight percent, or at least 20 weight percent, or at least 35 weight percent. Also within this range, the branched and highly branched polycarbonates can each independently be included in the composition in an amount of at most 45 weight percent, or at most 40 weight percent, or at most 35 weight percent, or at most 30 weight percent, each based on the total weight of the composition. In one aspect, the composition can include a branched polycarbonate, which can be included in the composition in an amount of 35 to 50 weight percent, or 35 to 45 weight percent. In one aspect, the composition can include a highly branched polycarbonate, which can be included in the composition in an amount of 35 to 50 weight percent, or 35 to 45 weight percent. In one aspect, the composition can include a combination of a branched and a highly branched polycarbonate, and the branched polycarbonate can be present in an amount of 5 to 30 weight percent, or 8 to 28 weight percent, or 10 to 25 weight percent, and the highly branched polycarbonate can be present in an amount of 10 to 35 weight percent, or 12 to 32 weight percent, or 15 to 30 weight percent, each based on the total weight of the composition.

[0088] In one aspect, the composition can optionally further include a second linear polycarbonate. The second linear polycarbonate is different from the above-mentioned linear polycarbonate, for example, in terms of chemical composition, molecular weight, or both. In one aspect, the second linear polycarbonate has a weight-average molecular weight greater than that of the linear polycarbonate. For example, as determined by GPC using polycarbonate standards, the second linear polycarbonate can have a weight-average molecular weight of 34,000 grams per mole or greater. For example, the second linear polycarbonate can have a weight-average molecular weight of 34,500 to 40,000 grams per mole. In one aspect, the second linear polycarbonate can be a linear bisphenol A homopolycarbonate and can have a weight-average molecular weight of 34,500 to 40,000 grams per mole.

[0089] In one aspect, one or more linear polycarbonates, the first poly(carbonate-siloxane) copolymer, and the second poly(carbonate-siloxane) copolymer, and when present, the branched polycarbonate, the highly branched polycarbonate, and the second linear polycarbonate can be derived from post-consumer recycled or post-industrial recycled materials, or can be produced from at least one monomer from a biobased or plastic waste feedstock.

[0090] The polycarbonate composition comprises a flame retardant having a phosphorus-nitrogen bond in an amount less than 1 wt%, or less than 0.5 wt%, or less than 0.1 wt%. In one aspect, the flame retardant having a phosphorus-nitrogen bond can be excluded from the polycarbonate composition. Exemplary flame retardants having a phosphorus-nitrogen bond can include phosphazenes, chlorinated phosphazenes, phosphoric esters amides, phosphonic esters amides, phosphinic esters amides, tris(aziridinyl)phosphine oxide, or combinations thereof.

[0091] The polycarbonate composition can optionally further comprise an additive composition. The additive composition can comprise one or more additives selected to achieve desired properties, provided that the additives are also selected so as not to significantly and adversely affect the chemical resistance, transparency, and mechanical properties of the polycarbonate composition. During the mixing of the components used to form the composition, the additive composition or the individual additives can be mixed at an appropriate time. The additives can be soluble or insoluble in the polycarbonate. For example, the additive composition can include an impact modifier, a flow modifier, a filler (such as a particulate, polytetrafluoroethylene (PTFE), glass, carbon, mineral, or metal), a reinforcing agent (such as glass fiber), an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet (UV) light stabilizer, a UV-absorbing additive, a plasticizer, a lubricant, a release agent (such as a mold release agent), an antistatic agent, an anti-fogging agent, an anti-microbial agent, a colorant (such as a dye or a pigment), a surface effect additive, a radiation stabilizer, or combinations thereof. For example, a combination of a heat stabilizer, a release agent, and an ultraviolet light stabilizer can be used. Generally, the additives are used in amounts that are generally known to be effective. For example, based on the total weight of the polymers of the composition, the total amount of the additive composition (except for any impact modifier, filler, or reinforcing agent) can be from 0.001 to 10 wt%, or from 0.01 to 5 wt%.

[0092] In one aspect, the composition can comprise a heat stabilizer additive. Heat stabilizer additives include organic phosphites (such as triphenyl phosphite, tris-(2,6-dimethylphenyl) phosphite, tris-(mixed mono- and di-nonylphenyl) phosphite, etc.), phosphonates (such as dimethyl phenylphosphonate, etc.), phosphates (such as trimethyl phosphate, etc.), or combinations thereof. The heat stabilizer can be tris(2,4-di-tert-butylphenyl) phosphate available as IRGAPHOS TM 168. Based on the total weight of the composition, the heat stabilizer is generally used in an amount of from 0.01 to 5 wt%.

[0093] There is a significant overlap among plasticizers, lubricants, and mold release agents, which include, for example, phthalates (such as octyl-4,5-epoxy-hexahydrophthalate), tris-(octyloxycarbonylethyl) isocyanurate, di- or poly-functional aromatic phosphates (such as resorcinol tetraphenyl diphosphate (RDP), bis(diphenyl) phosphate of hydroquinone, and bis(diphenyl) phosphate of bisphenol A); poly-α-olefins; epoxidized soybean oil; silicones, including silicone oils (such as poly(dimethyldiphenylsiloxane)); fatty acid esters (such as C 1-32 alkyl stearyl esters, such as methyl stearate and stearyl stearate, and esters of stearic acid, such as pentaerythritol tetrastearate, glyceryl tristearate (GTS), etc.), waxes (such as beeswax, lignite wax, paraffin wax, etc.) or combinations thereof. These are typically used in an amount of 0.01 to 5 wt% based on the total weight of the composition.

[0094] Light stabilizers, particularly ultraviolet (UV) absorption additives, also known as UV stabilizers, include hydroxybenzophenones (such as 2-hydroxy-4-n-octyloxybenzophenone), hydroxybenzotriazoles, cyanoacrylates, oxanilides, benzoxazinones (such as 2,2'-(1,4-phenylene)bis(4H-3,1-benzoxazin-4-one, commercially available under the trade name CYASORB TM UV-3638 from Cytec), aryl salicylates, hydroxybenzotriazoles (such as 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, and 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-phenol, commercially available under the trade name CYASORB TM 5411 from Cytec) or combinations thereof. Based on the total weight of the composition, the UV stabilizer can be present in an amount of 0.01 to 1 wt%, preferably 0.1 to 0.5 wt%, and more preferably 0.15 to 0.4 wt%.

[0095] The polycarbonate composition can optionally exclude other components not specifically described herein. For example, the polycarbonate composition can exclude linear polycarbonates, first and second poly(carbonate-siloxane) copolymers, branched and highly branched polycarbonates, and thermoplastic polymers of second linear polycarbonates. In one aspect, copolycarbonates other than the first and second poly(carbonate-siloxane) copolymers can be excluded from the composition. The composition can optionally minimize or exclude flame retardants.

[0096] In one aspect, the polycarbonate composition can comprise 79 to 89 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; and 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; wherein the polycarbonate composition has a total siloxane content of 1 to 3 weight percent, based on the total weight of the composition.

[0097] In one aspect, the polycarbonate composition can comprise 40 to 74 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; 5 to 30 weight percent of a branched polycarbonate containing 0.1-1.0 mol% of branching; and 10 to 35 weight percent of a highly branched polycarbonate containing 1.5-5.0 mol% of branching; wherein the polycarbonate composition has a total siloxane content of 1 to 3 weight percent, based on the total weight of the composition.

[0098] In one aspect, the polycarbonate composition can comprise 40 to 54 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; 35 to 50 weight percent of a branched polycarbonate that contains 0.1 to 1.0 mol% of branching; and wherein the polycarbonate composition has a total siloxane content of 1 to 3 weight percent, based on the total weight of the composition.

[0099] In one aspect, the polycarbonate composition can comprise 40 to 54 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; 35 to 50 weight percent of a second linear polycarbonate having a molecular weight of 35,000 g / mol or greater, as determined by gel permeation chromatography relative to a linear bisphenol A polycarbonate standard; wherein the polycarbonate composition has a total siloxane content of 1 to 3 weight percent, based on the total weight of the composition.

[0100] The composition can advantageously exhibit one or more desired properties. For example, it has been found that improved chemical resistance can be unexpectedly obtained with the compositions of the present disclosure. In an exemplary aspect, at a temperature of 23 °C, after exposing an ISO tensile bar to a sunscreen or insect repellent for 72 hours, at a stress of 0.5% or 1%, the yield tensile stress of the polycarbonate composition can be at least 50%, at least 75%, or at least 90% of the yield tensile stress of an unexposed reference sample tested at the same temperature. In one aspect, at a temperature of 23 °C, after exposing an ISO tensile bar to a sunscreen or insect repellent for 72 hours, at a stress of 0.5% or 1%, the elongation at break of the polycarbonate composition can be at least 50%, at least 75%, or at least 90% of the elongation at break of an unexposed reference sample tested at the same temperature.

[0101] The polycarbonate composition can further have a good melt viscosity, which aids in processing. The polycarbonate composition can have a melt volume rate (MVR, cubic centimeters per 10 minutes (cm 3 / 10 min)) of 3 to 20 or 3 to 15, greater than or equal to 3, as determined according to ASTM D1238-04 at a load of 1.2 kg at 300 °C for 6 minutes.

[0102] The polycarbonate composition can have a heat distortion temperature (HDT) of 110 °C or higher as measured according to ASTM D648 at 1.82 MPa on a sample plate with a thickness of 4 mm.

[0103] The polycarbonate composition can be transparent. For example, the polycarbonate composition can exhibit a transmittance of at least 60%, at least 70%, or at least 75% as determined according to ASTM D1003 on a molded sample having a thickness of 2.5 mm.

[0104] The polycarbonate composition can be prepared by various methods known in the art. For example, in a high-speed mixer or by manual mixing, powdered linear polycarbonate, poly(carbonate-siloxane), and other optional components can first be optionally blended with any fillers. The blend can then be fed via a hopper to the feed inlet of a twin-screw extruder. Alternatively, at least one component can be incorporated into the composition by feeding it directly into the extruder at the feed inlet and / or downstream via a side stuffer, or by mixing it with the desired polymer to form a masterbatch and feeding the masterbatch into the extruder. The extruder is typically operated at a temperature above that necessary to cause the composition to flow. The extrudate can be immediately quenched in a water bath and pelletized. If desired, the pellets so prepared can be a quarter inch long or less. Such pellets can be used for subsequent molding, shaping, or forming.

[0105] Also provided are formed, shaped, cast or molded articles comprising the polycarbonate composition. The polycarbonate composition can be molded into useful formed articles by a variety of methods such as injection molding, extrusion, rotational molding, blow molding and thermoforming. The articles can be molded articles, thermoformed articles, extruded films, extruded sheets, honeycomb structures, one or more layers of multi-layer articles, substrates for coating articles, and substrates for metallizing articles. Exemplary articles can include computer and business machine housings such as housings for displays, handheld electronic device housings such as housings for mobile phones, electrical connectors, and components of lighting fixtures, ornaments, household appliances, roofs, greenhouses, solariums, swimming pool enclosures, electronic device housings and signs, etc. In addition, the polycarbonate composition can be used in applications such as automotive panels and trim.Examples of suitable articles are, but are not limited to, aircraft, automobiles, trucks, military vehicles (including automobiles, aircraft, and watercraft), scooters and motorcycle exterior and interior components, including panels, quarter panels, rocker panels, trim, fenders, doors, deck lids, trunk lids, hoods, roofs, roof tops, bumpers, instrument panels, grilles, mirror housings, pillar trim, cladding, body side moldings, wheel covers, visors, door handles, spoilers, window frames, headlight bezels, headlights, taillights, taillight housings, taillight bezels, license plate housings, roof racks, and running boards; housings, enclosures, panels, and components for outdoor vehicles and devices; housings for electrical and telecommunications equipment; outdoor furniture; aircraft components; boats and marine equipment, including trim, housings, and enclosures; outboard motor housings; depth finder housings; personal watercraft; motorboats; pools; spas; hot tubs; steps; step coverings; architectural and building applications such as glassware, roofs, windows, floors, decorative window treatments; treated glass covers for pictures, paintings, posters, and similar display items; wall panels and doors; countertops; protected graphics; outdoor and indoor signs; housings, enclosures, panels, and components for automated teller machines (ATMs); computers; desktop computers; portable computers; laptop computers; handheld computer housings; monitors; printers; keyboards; fax machines; copiers; telephones; telephone bezels; mobile phones; radio transmitters; radio receivers; housings, enclosures, panels, and components for lawn and garden tractors, lawn mowers, and tools (including lawn and garden tools); window and door trim; sports equipment and toys; housings, enclosures, panels, and components for snowmobiles; recreational vehicle panels and components; playground equipment; shoelaces; articles made from plastic-wood combinations; golf course markers; utility manhole covers; lighting fixtures; lighting appliances; network interface device housings; transformer housings; air conditioner housings; cladding or seats for public transportation; cladding or seats for trains, subways, or buses; instrument enclosures; antenna housings; cladding for satellite antennas; coated helmets and personal protective equipment; coated synthetic or natural textiles; coated painted articles; coated dyed articles; coated fluorescent articles; coated foam articles; medical device housings; battery housings, including battery housings for electric vehicles, electric bicycles, and household and industrial electronics; components for charging equipment for electric vehicles, including wall box housings, connectors, etc.; wireless charging device assemblies; electronic device protective covers; kitchen appliance components; and similar applications.

[0106] The compositions of the present invention can be particularly used in articles for consumer electronic applications. For example, the article can be a component of a consumer electronic device, such as a game console, a game controller, a portable gaming device, a cellular phone, a television, a personal computer, a tablet computer, a laptop computer, a personal digital assistant, a portable media player, a digital camera, a portable music player, an appliance, a power tool, a robot, a toy, a greeting card, a home entertainment system, a speaker or a soundbar. In one aspect, the article can be an electronic housing for an adapter, a mobile phone, a smartphone, a GPS device, a laptop computer, a tablet computer, an e-reader, a copying machine or a solar device.

[0107] The compositions of the present disclosure can be particularly used in articles for healthcare applications, such as components used in healthcare, such as handheld devices and computer monitors, and particularly for the touchscreens of such devices.

[0108] The polycarbonate compositions are further illustrated by the following non-limiting examples.

[0109] Examples

[0110] The materials for the following examples are provided in Table 1.

[0111] Table 1

[0112]

[0113] Typical compounding procedures are described below: Various formulations are prepared by direct dry blending of the raw materials and homogenized with a paint stirrer before compounding. These formulations are compounded on a 26 mm Coperion ZSK co-rotating twin screw extruder. Typical extrusion profiles are listed in Table 2.

[0114] Table 2

[0115] Parameter Unit 25mm ZSK Feed temperature ℃ 177 Zone 1 temperature ℃ 232 Zone 2 - 8 temperature ℃ 266 Mold temperature ℃ 271 Screw speed rpm 400 Throughput kg / h 70 Torque ％ 75-80

[0116] A DEMAG molding machine is used to mold test specimens for standard physical property tests (parameters are shown in Table 3).

[0117] Table 3

[0118] Parameter Unit Pre - drying time h 4 Pre - drying temperature ℃ 120 Zone 1 - 3 temperature ℃ 290 Nozzle temperature ℃ 290 Mold temperature ℃ 82 Screw speed rpm 100 Back pressure bar 3.4 Injection time s 1-2 Approximate cycle time s 31-35

[0119] Sample preparation and test methods are described in Table 4.

[0120] Table 4

[0121]

[0122] Chemical resistance was determined according to ASTM D-543. Specifically, chemical resistance can be demonstrated by the retention rate (expressed as %) of yield tensile strength and elongation at break. After exposure to the chemical reagent, the chemical resistance was evaluated on 3.2 mm ASTM tensile bars at 23 °C. Specifically, the ASTM tensile bars were bent to a specific strain level (e.g., 0.5% or 1% in the test fixture), and the bars were kept constantly exposed to the strain and the chemical reagent for a specified test period. The bars can be wrapped such that they remain saturated when in contact with the strain area. After a predetermined amount of time, the retention rate (expressed as %) of yield tensile stress and elongation at break was measured.

[0123] Table 5 shows the compositions and properties of the following examples. The amount of each component is provided in weight percent based on the total weight of the composition.

[0124] Table 5

[0125]

[0126]

[0127] * These materials are visually opaque and transmittance / haze was not measured

[0128] As shown in Table 5, the comparative examples generally presented a balance of processability and good mechanical properties, but were not chemical resistant for both the sunscreen and insect repellent wipes tested. The compositions of CE2 - CE4 showed that the addition of branched or highly branched polycarbonate components negatively affected chemical resistance.

[0129] Surprisingly, therefore, the compositions according to E1 - E3 exhibited improved chemical resistance compared to the CE1 - CE4 compositions. In addition, the compositions of E1 - E3 had a lower total siloxane content relative to CE1 - CE4 and CE6 - CE8 and thus also had improved transparency. It was also noted that the compositions of CE4 and E1 included similar amounts of PC - Si, B - PC, and H - PC components, yet the chemical resistance performance of the E1 composition was significantly improved. The compositions of E4 - E5 and CE5 further showed that reducing the amount of highly branched polycarbonate and increasing the amount of branched polycarbonate could provide an enhanced balance of properties, including excellent chemical resistance. Accordingly, the present disclosure provides polycarbonate compositions with significantly improved chemical resistance.

[0130] The present invention further encompasses the following aspects.

[0131] Aspect 1: A polycarbonate composition comprising: 35 to 94 weight percent of a linear polycarbonate; 5 to 20 weight percent of a first poly(carbonate-siloxane) copolymer having a siloxane content of 4 to 15 weight percent based on the total weight of the first poly(carbonate-siloxane) copolymer; and 1 to 6 weight percent of a second poly(carbonate-siloxane) copolymer having a siloxane content of 35 to 60 weight percent based on the total weight of the second poly(carbonate-siloxane) copolymer; wherein the weight percent of each component is based on the total weight of the composition; wherein the polycarbonate composition has a total siloxane content of less than 2.5 weight percent based on the total weight of the composition; and wherein the composition comprises less than 1 weight percent of a flame retardant having a phosphorus-nitrogen bond.

[0132] Aspect 2: The polycarbonate composition according to Aspect 1, further comprising a highly branched polycarbonate comprising 1.5 to 5.0 mol% of branching.

[0133] Aspect 3: The polycarbonate composition according to Aspect 1 or 2, further comprising a branched polycarbonate comprising 0.1 to 1.0 mol% of branching.

[0134] Aspect 4: The polycarbonate composition according to any one of Aspects 1 to 3, further comprising a second linear polycarbonate having a molecular weight of 34,000 g / mol or greater as determined by gel permeation chromatography relative to a linear bisphenol A polycarbonate standard.

[0135] Aspect 5: The polycarbonate composition according to any one of Aspects 1 to 4, wherein a flame retardant having a phosphorus-nitrogen bond is excluded from the composition, preferably, wherein the flame retardant having a phosphorus-nitrogen bond comprises phosphazene, chlorinated phosphazene, phosphoester amide, phosphoric amide, phosphonic amide, phosphinic amide, tris(aziridinyl)phosphine oxide, or a combination thereof.

[0136] Aspect 6: The polycarbonate composition according to Aspect 1, comprising: 79 to 89 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; and 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; wherein the polycarbonate composition has a total siloxane content of 1 to 3 weight percent based on the total weight of the composition.

[0137] Aspect 7: The polycarbonate composition according to Aspect 1, comprising: 40 to 74 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; 5 to 30 weight percent of a branched branched polycarbonate comprising 0.1 to 1.0 mol% of branching; and 10 to 35 weight percent of a highly branched polycarbonate comprising 1.5 to 5.0 mol% of branching; wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to 3 weight percent.

[0138] Aspect 8: The polycarbonate composition according to Aspect 1, comprising: 40 to 54 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; 35 to 50 weight percent of a branched polycarbonate, the branched polycarbonate comprising 0.1 to 1.0 mol% of branching; and wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to 3 weight percent.

[0139] Aspect 9: The polycarbonate composition according to Aspect 1, comprising: 40 to 54 weight percent of a linear polycarbonate; 10 to 16 weight percent of a first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of a second poly(carbonate-siloxane) copolymer; 35 to 50 weight percent of a second linear polycarbonate having a molecular weight of 35,000 g / mol or greater, as determined by gel permeation chromatography relative to a linear bisphenol A polycarbonate standard; wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to 3 weight percent.

[0140] Aspect 10: The polycarbonate composition according to any one of Aspects 1 to 9, further comprising an additive composition.

[0141] Aspect 11: The polycarbonate composition according to any one of Aspects 1 to 10, wherein a molded sample of the composition has: a transmittance of at least 60%, at least 70% or at least 75% as measured according to ASTM D1003 on a molded sample having a thickness of 2.5 mm; and at a temperature of 23°C, after exposing an ISO tensile bar to a sunscreen or an insect repellent for 72 hours, at a stress of 0.5% or 1%, a yield tensile stress of at least 50%, at least 75% or at least 90% of the yield tensile stress of an unexposed reference sample tested at the same temperature.

[0142] Aspect 12: A method of making a polycarbonate composition according to any one of the preceding aspects, the method comprising melt mixing the components of the composition.

[0143] Aspect 13: The method according to aspect 12 further comprises molding, casting, or extruding the composition to provide an article.

[0144] Aspect 14: An article comprising a polycarbonate composition according to any one of aspects 1 to 11.

[0145] Aspect 15: The article according to aspect 14, wherein the article is a component of a consumer electronics component or a medical device.

[0146] Alternatively, the composition, method, and article can comprise, consist of, or consist essentially of any suitable materials, steps, or components disclosed herein. The composition, method, and article can additionally or alternatively be formulated so as to be free or substantially free of any materials (or species), steps, or components that would otherwise be unnecessary for achieving the functions or purposes of the composition, method, and article.

[0147] All ranges disclosed herein include the endpoints, and the endpoints can be combined independently of each other. "Combination" includes blends, mixtures, alloys, reaction products, etc. The terms "first", "second", etc. do not denote any order, quantity, or importance, but are used to distinguish one element from another. Unless otherwise specified herein or clearly contradicted by the context, the terms "a" and "an" and "the" do not denote a limitation of quantity, but are to be construed as covering the singular and the plural. Unless otherwise expressly stated, "or" means "and / or". Reference throughout the specification to "one aspect" means that the particular element described in connection with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. As used herein, the term "their combination" includes one or more of the listed elements and is open-ended, allowing for the presence of one or more similar elements not named. Additionally, it should be understood that the described elements can be combined in any suitable manner in the various aspects.

[0148] Unless specified to the contrary herein, all test standards are the latest standards in effect as of the filing date of the present application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0149] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in this application contradicts or conflicts with a term in the incorporated references, the term from this application prevails over the conflicting term from the incorporated references.

[0150] Describe compounds using standard nomenclature. For example, any position not substituted by any indicated group should be understood to have its valence filled by a bond or hydrogen atom as indicated. A dash (“-”) not between two letters or symbols is used to indicate the point of attachment of a substituent. For example, -CHO is attached through the carbon of the carbonyl group.

[0151] As used herein, the term “hydrocarbyl,” whether used alone or as a prefix, suffix, or fragment of another term, refers to a residue containing only carbon and hydrogen. The residue can be aliphatic or aromatic, linear, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, linear, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when a hydrocarbyl residue is described as substituted, it can optionally contain heteroatoms in addition to and in place of carbon and hydrogen members of the substituent residue. Thus, when specifically described as substituted, a hydrocarbyl residue can also contain one or more carbonyl, amino, hydroxy, etc., or it can contain heteroatoms within the backbone of the hydrocarbyl residue. The term “alkyl” refers to a branched or linear, saturated aliphatic hydrocarbyl group, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, sec-pentyl, and n-hexyl and sec-hexyl. “Alkenyl” refers to a linear or branched monovalent hydrocarbyl group having at least one carbon-carbon double bond (e.g., vinyl (-HC=CH 2 ))). “Alkoxy” refers to an alkyl group attached through oxygen (i.e., alkyl-O-), for example, methoxy, ethoxy, and sec-butoxy. “Alkylene” refers to a linear or branched, saturated divalent aliphatic hydrocarbyl group (e.g., methylene (-CH 2 -) or propylene (-(CH 2 )) 3 -)). “Cycloalkylene” refers to a divalent cyclic alkylene, -C n H 2n-x, where x is the number of hydrogens replaced by cyclization. "Cycloalkenyl" means a monovalent group having one or more rings and one or more carbon-carbon double bonds in the ring, where all ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing a specified number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. "Arylene" means a divalent aryl. "Alkylenearylene" means an arylene substituted with an alkyl group. "Arylalkylene" means an alkylene substituted with an aryl group (e.g., benzyl). The prefix "halo" means a group or compound including one or more of the substituents fluorine, chlorine, bromine, or iodine. Combinations of different halogen atoms (e.g., bromine and fluorine) or only chlorine atoms may be present. The prefix "hetero" means that a compound or group includes at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatoms), where each heteroatom is independently N, O, S, Si, or P. "Substituted" means that a compound or group is substituted with at least one (e.g., 1, 2, 3, or 4) substituents, where the substituents may each independently be C 1-9 alkoxy, C 1-9 haloalkoxy, nitro (-NO 2 ), cyano (-CN), C 1-6 alkylsulfonyl (-S(=O) 2 -alkyl), C 6-12 arylsulfonyl (-S(=O) 2 -aryl), thiol (-SH), thiocyanato (-SCN), tosyl (CH 3 C 6 H 4 SO 2 -), C 3-12 cycloalkyl, C 2-12 alkenyl, C 5-12 cycloalkenyl, C 6-12 aryl, C 7-13 arylalkylene, C 4-12 heterocycloalkyl, and C 3-12 heteroaryl in place of hydrogen, provided that the normal valences of the substituting atoms are not exceeded. The number of carbon atoms indicated in a group does not include any substituents. For example, -CH 2 CH 2 CN is an alkyl substituted with a nitrile 2 .

[0152] Although specific aspects have been described, alternatives, modifications, variations, improvements, and substantial equivalents may occur to the applicant or other skilled persons in the art that are presently unforeseen or may be unforeseen. Accordingly, the appended claims, as filed and as they may be amended, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.

Claims

1. A polycarbonate composition comprising: 35 to 94 weight percent of a linear polycarbonate; 5 to 20 weight percent of a first poly(carbonate-siloxane) copolymer having a siloxane content of 4 to 15 weight percent based on the total weight of the first poly(carbonate-siloxane) copolymer; and 1 to 6 weight percent of a second poly(carbonate-siloxane) copolymer having a siloxane content of 35 to 60 weight percent based on the total weight of the second poly(carbonate-siloxane) copolymer; wherein, the weight percents of the components are based on the total weight of the composition; wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of less than 2.2 weight percent; wherein the composition comprises less than 1 weight percent of a flame retardant having a phosphorus-nitrogen bond; and wherein, as measured on a molded sample having a thickness of 2.5 mm according to ASTM D1003, the molded sample of the composition has a transmittance of at least 60%, at least 70% or at least 75%.

2. The polycarbonate composition according to claim 1, further comprising a highly branched polycarbonate comprising 1.5 to 5.0 mol% of branching.

3. The polycarbonate composition according to claim 1 or 2, further comprising a branched polycarbonate comprising 0.1 to 1.0 mol% of branching.

4. The polycarbonate composition according to any one of claims 1 to 3, further comprising a second linear polycarbonate having a weight average molecular weight of 34,000 g / mol or greater as measured by gel permeation chromatography relative to a linear bisphenol A polycarbonate standard.

5. The polycarbonate composition according to any one of claims 1 to 4, wherein, the composition does not contain the flame retardant having a phosphorus-nitrogen bond, preferably, wherein the flame retardant having a phosphorus-nitrogen bond comprises phosphonitrile, chlorophosphonitrile, phosphoroester amide, phosphoric amide, phosphonic amide, phosphinic amide, tris(aziridinyl)phosphine oxide or a combination thereof.

6. The polycarbonate composition according to claim 1, comprising: 79 to 89 weight percent of the linear polycarbonate; 10 to 16 weight percent of the first poly(carbonate-siloxane) copolymer; and 1 to 3 weight percent of the second poly(carbonate-siloxane) copolymer; wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to less than 2.2 weight percent.

7. The polycarbonate composition according to claim 1, comprising: 40 to 74 weight percent of the linear polycarbonate; 10 to 16 weight percent of the first poly(carbonate-siloxane) copolymer; 1 to 3 weight percent of the second poly(carbonate-siloxane) copolymer; 5 to 30 weight percent of a branched polycarbonate comprising 0.1 to 1.0 mol% of branching; and 10 to 35 weight percent of a highly branched polycarbonate, the highly branched polycarbonate comprising 1.5 to 5.0 mole percent of branching; wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to less than 2.2 weight percent.

8. The polycarbonate composition according to claim 1, comprising: 40 to 54 weight percent of the linear polycarbonate; 10 to 16 weight percent of the first poly( carbonate - siloxane) copolymer; 1 to 3 weight percent of the second poly( carbonate - siloxane) copolymer; 35 to 50 weight percent of a branched polycarbonate, the branched polycarbonate comprising 0.1 to 1.0 mole percent of branching; and wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to less than 2.2 weight percent.

9. The polycarbonate composition according to claim 1, comprising: 40 to 54 weight percent of the linear polycarbonate; 10 to 16 weight percent of the first poly( carbonate - siloxane) copolymer; 1 to 3 weight percent of the second poly( carbonate - siloxane) copolymer; 35 to 50 weight percent of a second linear polycarbonate having a weight - average molecular weight of 35,000 g / mol or greater as determined by gel permeation chromatography relative to a linear bisphenol A polycarbonate standard; wherein, based on the total weight of the composition, the polycarbonate composition has a total siloxane content of 1 to less than 2.2 weight percent.

10. The polycarbonate composition according to any one of claims 1 to 9, further comprising an additive composition.

11. The polycarbonate composition according to any one of claims 1 to 10, wherein, the molded sample of the composition has: at a temperature of 23°C, after exposing an ISO tensile bar to a sunscreen or insect repellent for 72 hours, at a stress of 0.5% or 1%, the yield tensile stress is at least 50%, at least 75% or at least 90% of the yield tensile stress of an unexposed reference sample tested at the same temperature.

12. A method of making a polycarbonate composition according to any one of the preceding claims, the method comprising melt - mixing the components of the composition.

13. The method according to claim 12, further comprising molding, casting or extruding the composition to provide an article.

14. An article comprising a polycarbonate composition according to any one of claims 1 to 11.

15. The article according to claim 14, wherein the article is a component of a consumer electronics assembly or a medical device.

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