Patent Description:
Polycarbonates are useful in the manufacture of articles and components for a wide range of applications, from automotive parts to electronic appliances. Because of their broad use, particularly in high-heat application such as lenses and sensors, it is desirable to provide polycarbonate compositions with low color shift on long term aging. For example, <CIT> discloses a polycarbonate composition comprising a high heat polycarbonate and optionally sulfur-containing stabilizers, having low levels of colored impurities. Nevertheless, no disclosure regarding a long-term reduction of yellowness caused by aging is made. Attempts to incorporate stabilizing additives to polycarbonates have been made, such as phenolic antioxidants, organic phosphite or phosphine stabilizers, and benzofuranone stabilizers, for example in <CIT>, which discloses polycarbonate compositions obtained from bisphenol A and phosgene or a phosgene analogues, further comprising one or more additives selected from the group consisting of benzofuranone stabilizers.

There accordingly remains a need in the art for polycarbonate compositions that are stable to long term aging. It would be a further advantage to provide polycarbonate compositions stable to long term aging when increased sulfur levels are present in the polycarbonate composition.

The above-described and other deficiencies of the art are met by a polycarbonate composition comprising: a high heat copolycarbonate comprising high heat carbonate units, wherein a homopolycarbonate of the high heat carbonate units has a glass transition temperature of <NUM>-<NUM> as determined by differential scanning calorimetry as per ASTM D3418 with a heating rate <NUM>/min and wherein the high heat carbonate units comprise formula
<CHM>
or a combination of formula
<CHM>
and formula
<CHM>
and optionally low heat carbonate units, wherein a homopolycarbonate of the low heat carbonate units has a glass transition temperature of up to <NUM> as determined by differential scanning calorimetry as per ASTM D3418 with heating rate of <NUM>/min, wherein: Ra and Rb are each independently C<NUM>-<NUM> alkyl, Rg is C<NUM>-<NUM> alkyl, p and q are each independently <NUM>-<NUM>, and t is <NUM>-<NUM>; Rc and Rd are each independently a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> cycloalkyl, or C<NUM>-<NUM> alkoxy, ; m and n are each independently <NUM>-<NUM>, each R<NUM> is independently C<NUM>-<NUM> alkyl or hydrogen, R<NUM> is C<NUM>-<NUM> alkyl or phenyl optionally substituted with <NUM>-<NUM> C<NUM>-<NUM> alkyl groups, and g is <NUM>-<NUM>; greater than <NUM> to <NUM> ppm of an aryl benzofuranone stabilizer; optionally, <NUM>-<NUM> ppm of a sulfur-containing stabilizer compound; optionally, <NUM>-<NUM> ppm of an organosulfonic stabilizer; optionally, a bisphenol A homopolycarbonate; each based on the total parts by weight of the composition, wherein a molded sample of the composition having a thickness of <NUM> millimeters and aged for <NUM> hours at <NUM> has a change in a yellowness index value of less than <NUM>, or less than <NUM>, or less than <NUM> as compared with an initial yellowness index value of the molded sample, as measured in accordance with ASTM D1925.

In another aspect, a method of manufacture comprises combining the above-described components to form a polycarbonate composition.

In yet another aspect, an article comprises the above-described polycarbonate composition.

In still another aspect, a method of manufacture of an article comprises molding, extruding, or shaping the above-described polycarbonate composition into an article.

The above described and other features are exemplified by the following drawings, detailed description, examples, and claims.

Color and color stability are an important requirement for various high temperature applications including lenses and sensors. High-heat polycarbonate resins with either benzylic or tertiary protons are especially susceptible to color shift on heat aging. Thus, it would be beneficial to mitigate the color shift on long-term heat aging. It would be especially beneficial to mitigate the color shift on long term heat aging when increased sulfur levels are present whether intentionally added or as of a result of impurities in the monomers or process chemicals.

Surprisingly, the inventors hereof have discovered that the addition of aryl benzofuranone stabilizers can dramatically improve the color stability of high heat copolycarbonates upon aging. This is a surprising result because sulfur impurities produced during monomer synthesis are associated with undesirable color formation in high heat copolycarbonate compositions. Advantageously, in the case of compositions with added sulfur stabilizers, aryl benzofuranone stabilizers suppressed the shift that has been observed for polycarbonate compositions that include sulfur-containing stabilizer compounds. The polycarbonate compositions include a high heat copolycarbonate comprising high heat aromatic carbonate units, optionally low heat carbonate units, an aryl benzofuranone stabilizer, and optionally, a sulfur-containing stabilizer compound.

As stated above, the high heat copolycarbonates can comprise repeating carbonate units including low heat carbonate units (<NUM>) and high heat aromatic carbonate units (<NUM>)
<CHM>
wherein RL is derived from the corresponding low heat aromatic dihydroxy monomer and RH is derived from the corresponding high heat aromatic dihydroxy monomer. Each of these is described in further detail below.

As used herein, a "low heat aromatic dihydroxy monomer" means a compound that can be used to manufacture a polycarbonate homopolymer having a Tg of <NUM>-<NUM>, as determined by differential scanning calorimetry (DSC) as per ASTM D3418 with a <NUM>/min heating rate. Such monomers generally have <NUM> or fewer carbon atoms. Exemplary low heat aromatic groups (RL groups) in low heat aromatic carbonate units (<NUM>) can be of formula (1a)
<CHM>
wherein Ra and Rb are each independently a halogen, C<NUM>-<NUM> alkoxy, or C<NUM>-<NUM> alkyl, c is <NUM>-<NUM>, and p and q are each independently integers of <NUM> or <NUM>. In an aspect, p and q is each <NUM>, or p and q is each <NUM> and Ra and Rb are each a methyl, disposed meta to the hydroxy group on each arylene group. Xa in formula (<NUM>) is a bridging group connecting the two hydroxy-substituted aromatic groups, where the bridging group and the hydroxy substituent of each C<NUM> arylene group are disposed ortho, meta, or para (preferably para) to each other on the C<NUM> arylene group, for example, a single bond, -O-, -S-, -S(O)-, -S(O)<NUM>-, -C(O)-, or a C<NUM>-<NUM> organic group, which can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. For example, Xa can be a C<NUM>-<NUM> cycloalkylidene, a C<NUM>-<NUM> alkylidene of the formula -C(Rc)(Rd) - wherein Rc and Rd are each independently hydrogen, C<NUM>-<NUM> alkyl, or a group of the formula -C(=Re)- wherein Re is a divalent C<NUM>-<NUM> hydrocarbon group. Some illustrative examples of dihydroxy compounds that can be used are described, for example, in <CIT>, <CIT>, and <CIT>.

In an aspect, the low heat aromatic group is of the formula
<CHM>
and can be derived from <NUM>,<NUM>-is (<NUM>-hydroxyphenyl)propane), also known as bisphenol A (BPA). The high heat aromatic carbonate units (<NUM>) can be derived from the corresponding high heat bisphenol monomers. As used herein, "high heat bisphenol monomer" means a monomer where the corresponding homopolycarbonate of the monomer has a Tg of <NUM> or greater. A low heat bisphenol monomer is a monomer where the corresponding homopolycarbonate of the monomer has a Tg of less than <NUM>. Preferably the low heat bisphenol monomer is a monomer where the corresponding homopolycarbonate has a Tg of less than <NUM>, or less than <NUM>, and the high heat bisphenol monomer is a monomer where the corresponding homopolycarbonate has a Tg of <NUM> or greater, or <NUM> or greater. The homopolycarbonate formed by the low heat monomer can have a minimum Tg of <NUM>. The homopolycarbonate formed by the high heat monomer can have a maximum Tg of <NUM>. In an aspect, the high heat copolycarbonate has a Tg of <NUM> -<NUM>, <NUM>-<NUM>, or <NUM>-<NUM>, or <NUM>-<NUM>, or <NUM>-<NUM>. Each of the Tgs of the homopolycarbonates and the copolycarbonates can be determined by differential scanning calorimetry as per ASTM D3418 with a heating rate <NUM>/min.

Such monomers generally have <NUM> or more carbon atoms. Exemplary RH groups in high heat aromatic carbonate units (<NUM>) can be of formulas (2a)-(<NUM>)
<CHM>
<CHM>
<CHM>
wherein Rc and Rd are each independently a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> cycloalkyl, or C<NUM>-<NUM> alkoxy, each Rf is hydrogen or both Rf together are a carbonyl group, each R<NUM> is independently C<NUM>-<NUM> alkyl, R<NUM> is hydrogen, C<NUM>-<NUM> alkyl, or phenyl optionally substituted with <NUM>-<NUM> C<NUM>-<NUM> alkyl groups, R<NUM> is independently C<NUM>-<NUM> alkyl or phenyl, preferably methyl, Xa is a C<NUM>-<NUM> polycyclic aryl, C<NUM>-<NUM> mono- or polycycloalkylene, C<NUM>-<NUM> mono- or polycycloalkylidene, -C(Rh)(Rg)- group wherein Rh is hydrogen, C<NUM>-<NUM> alkyl, or C<NUM>-<NUM> aryl and Rg is C<NUM>-<NUM> aryl, or -(Qa)x-G-(Qb)y- group wherein Qa and Qb are each independently a C<NUM>-<NUM> alkylene, G is a C<NUM>-<NUM> cycloalkylene, x is <NUM> or <NUM>, and y is <NUM>, and j, m, and n are each independently <NUM>-<NUM>. A combination of high heat aromatic groups can be used.

In an aspect, Rc and Rd are each independently a C<NUM>-<NUM> alkyl, or C<NUM>-<NUM> alkoxy, each R<NUM> is methyl, each R<NUM> is independently C<NUM>-<NUM> alkyl, R<NUM> is methyl, or phenyl, each R<NUM> is independently C<NUM>-<NUM> alkyl, or phenyl, preferably methyl, Xa is a C<NUM>-<NUM> polycyclic aryl, C<NUM>-<NUM> mono-or polycycloalkylene, C<NUM>-<NUM> mono- or polycycloalkylidene, -C(Rf)(Rg)- wherein Rf is hydrogen, C<NUM>-<NUM> alkyl, or C<NUM>-<NUM> aryl and Rg is C<NUM>-<NUM> alkyl, C<NUM>-<NUM> cycloalkyl, or C<NUM>-<NUM> aryl, or -(Q<NUM>)x-G-(Q<NUM>)y-group, wherein Q<NUM> and Q<NUM> are each independently a C<NUM>-<NUM> alkylene and G is a C<NUM>-<NUM> cycloalkylene, x is <NUM> or <NUM>, and y is <NUM> or <NUM>, and j, m, and n are each independently <NUM> or <NUM>.

Exemplary high heat aromatic groups RH include those of the formulas:
<CHM>
<CHM>
<CHM>
<CHM>
wherein Rc and Rd are the same as defined for formulas (2a)-(<NUM>), each R<NUM> is independently C<NUM>-<NUM> alkyl, m and n are each independently <NUM>-<NUM>, each R<NUM> is independently C<NUM>-<NUM> alkyl or hydrogen, R<NUM> is C<NUM>-<NUM> alkyl or phenyl optionally substituted with <NUM>-<NUM> C<NUM>-<NUM> alkyl groups, and g is z10. In a specific aspect each bond of the bisphenol group is located para to the linking group that is Xa. In an aspect, Rc and Rd are each independently a C<NUM>-<NUM> alkyl, or C<NUM>-<NUM> alkoxy, each R<NUM> is methyl, x is <NUM> or <NUM>, y is <NUM>, and m and n are each independently <NUM> or <NUM>.

The high heat aromatic group is preferably of the formulas
<CHM>
<CHM>
wherein R<NUM> is methyl or phenyl, each R<NUM> is methyl, and g is <NUM>-<NUM>. Preferably, the high heat bisphenol group is derived from <NUM>-phenyl-<NUM>,<NUM>'-bis(<NUM>-hydroxyphenyl) phthalimidine (PPPBP) or from <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethyl-cyclohexane (BP-TMC).

Preferably, the high heat aromatic group is derived from the corresponding bisphenol, in particular from <NUM>,<NUM>-dihydroxy-5a,10b-diphenyl-coumarano-<NUM>',<NUM>',<NUM>,<NUM>-coumarane (corresponding to structure 2b-1a), <NUM>,<NUM>'-(<NUM>,<NUM>-dimethyl-<NUM>,<NUM>-dihydro-<NUM>-indene-<NUM>,<NUM>-diyl)diphenol (corresponding to structure 2c-1a), <NUM>-phenyl-<NUM>,<NUM>'-bis(<NUM>-hydroxyphenyl) phthalimidine (PPPBP) (corresponding to structure 2e-1a), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)-<NUM>,<NUM>,<NUM>-trimethyl-cyclohexane (BPI) (corresponding to structure <NUM>-5a), <NUM>,<NUM>'-(<NUM>-phenylethylidene)bisphenol (corresponding to structure <NUM>-6a), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)fluorene (corresponding to structure (<NUM>-7a), <NUM>,<NUM>-bis(<NUM>-hydroxyphenyl)cyclododecane (corresponding to structure <NUM>-9a), or a combination thereof.

The high heat copolycarbonates can comprise: <NUM>-<NUM> mole percent (mol%) of the low heat carbonate units (<NUM>), preferably bisphenol A carbonate units and <NUM>-<NUM> mol% of the high heat aromatic carbonate units (<NUM>). Preferably, the high heat carbonate units are derived from BPI, PPPBP, or a combination thereof. If a combination of two high heat aromatic monomers is used, such as BPI and PPPBP, the high heat copolycarbonate can have <NUM>-<NUM> mol% of a first high heat aromatic carbonate units and <NUM>-<NUM> mol% of a second high heat aromatic carbonate units, or <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, or <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, each based on the total number of carbonate units in the high heat copolycarbonates.

In another aspect, the high heat copolycarbonates can comprise <NUM>-<NUM> mol% of the low heat carbonate units (<NUM>), preferably bisphenol A carbonate units, and <NUM>-<NUM> mol% of the high heat aromatic carbonate units (<NUM>). Preferably, the high heat carbonate units are derived from BPI, PPPBP, or a combination thereof. If a combination of two high heat aromatic monomers is used, such as BPI and PPPBP, the high heat copolycarbonate can have <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, or <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, or <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, each based on the total number of carbonate units in the high heat copolycarbonates.

In another aspect, the high heat copolycarbonate can comprise: <NUM>-<NUM> mol% of low heat aromatic carbonate units (<NUM>), preferably bisphenol A carbonate units, and <NUM>-<NUM> mol% of the high heat aromatic carbonate units (<NUM>). Preferably, the high heat carbonate units are derived from BPI, PPPBP, or a combination thereof. If a combination of two high heat aromatic monomers is used, such as BPI and PPPBP, the high heat copolycarbonate can have <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, or <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, or <NUM>-<NUM> mol% of the first high heat aromatic carbonate units and <NUM>-<NUM> mol% of the second high heat aromatic carbonate units, each based on the total number of carbonate units in the high heat copolycarbonates.

The high heat copolycarbonates can be manufactured by processes such as interfacial polymerization and melt polymerization, which are known, and are described for example in <CIT> and <CIT>. Branched polycarbonate blocks can be prepared by adding a branching agent during polymerization, for example trimellitic acid, trimellitic anhydride, trimellitic trichloride, tris-p-hydroxyphenylethane, isatin-bis-phenol, tris-phenol TC (<NUM>,<NUM>,<NUM>-tris((p-hydroxyphenyl)isopropyl)benzene), tris-phenol PA (<NUM>(<NUM>(<NUM>,<NUM>-bis(p-hydroxyphenyl)-ethyl) alpha, alpha-dimethyl benzyl)phenol), <NUM>-chloroformyl phthalic anhydride, trimesic acid, and benzophenone tetracarboxylic acid. The branching agents can be added at a level of <NUM>-<NUM> wt%. Combinations of linear polycarbonates and branched polycarbonates can be used.

An end-capping agent (also referred to as a chain stopper agent or chain terminating agent) can be included during polymerization to provide end groups, for example monocyclic phenols such as phenol, p-cyanophenol, and C<NUM>-<NUM> alkyl-substituted phenols such as p-cumyl-phenol, resorcinol monobenzoate, and p-and tertiary-butyl phenol, monoethers of diphenols, such as p-methoxyphenol, monoesters of diphenols such as resorcinol monobenzoate, functionalized chlorides of aliphatic monocarboxylic acids such as acryloyl chloride and methacryoyl chloride, and mono-chloroformates such as phenyl chloroformate, alkyl-substituted phenyl chloroformates, p-cumyl phenyl chloroformate, and toluene chloroformate. Combinations of different end groups can be used. The high heat copolycarbonates can comprise a phenolic endcap content of level less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm; or a carbamate endcap content of less than <NUM> ppm, or less than <NUM> ppm, or less than <NUM> ppm; or a combination thereof, each based on the total weight of the high heat copolycarbonate. The endcap content was determined using phosphorous nuclear magnetic resonance (<NUM>P-NMR) analysis.

The high heat copolycarbonates in some aspects can have a weight average molecular weight (Mw) of <NUM>,<NUM>-<NUM>,<NUM> Da, <NUM>,<NUM>-<NUM>,<NUM> Da, or <NUM>,<NUM>-<NUM>,<NUM> Da, as measured by gel permeation chromatography (GPC), using a crosslinked styrene-divinylbenzene column and calibrated to BPA homopolycarbonate references. GPC samples can be prepared at a concentration of <NUM> per ml and eluted at a flow rate of <NUM> per minute.

The high heat copolycarbonates can have sulfur present as a contaminant in the components used in the manufacture of the high heat copolycarbonates, i.e., the high heat aromatic dihydroxy monomer, the low heat aromatic dihydroxy monomer, endcapping agents, and the carbonate source, for example. The high heat copolycarbonates can have a sulfur content of up to <NUM> ppm, up to <NUM> ppm, up to <NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, each based on the total weight of the high heat copolycarbonate.

The sulfur level of the high heat copolycarbonates can be measured by several methods. A commercially available Total Sulfur Analysis based on combustion and coulometric detection (fluorescence/chemiluminescence) can be used for samples that do not contain high levels of nitrogen. In the use of fluorescence/chemiluminescence detection of sulfur, interference of high concentrations of nitrogen concentrations becomes significant when analyzing sulfur at trace level. During combustion, the nitrogen present in the sample is converted into nitric oxide molecules (NO). During the absorption and excitation stage of the sulfur analyzer with UV-Fluorescence detection, NO-molecules interferes by emitting light at the same wavelength as SO2. Therefore, in samples with nitrogen content, it is advisable to use a different technique which is free of these interferences. In such cases, inductively coupled plasma mass spectrometry (ICP-MS) can be used. However, this technique can also be affected by interferences. For sulfur, the mass-to-charge ratios (m/z) of its main isotopes (<NUM>+ and <NUM>+) overlap with polyatomic ions such as <NUM>+, (16OH)<NUM>+, <NUM>+, and 14N18O+, which can affect sensitivity and accuracy of the measurement (<NPL>)). However, this can be overcome by introducing O<NUM> in a pressurized reaction cell and monitoring SO+ rather than S+. Thus, the analytical signal is recorded in a m/z region with less intense interfering signals (<NPL>);<NPL>)). Lastly, a nitrogen-containing sample can be analyzed using a Triple Quadrupole ICP-MS (ICP-QQQ) which eliminates such interferences.

The polycarbonate compositions can further comprise a BPA homopolycarbonate. The polycarbonate compositions can comprise <NUM>-<NUM> wt%, or <NUM>-<NUM> wt%, or <NUM>-<NUM> wt%, or <NUM>-<NUM> wt% of the high heat copolycarbonate, each based on the total weight of the polycarbonate compositions. In some aspects, no BPA homopolycarbonate is present in the polycarbonate compositions. When a BPA homopolycarbonate is present, it can be, for example in an amount of <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, <NUM>-<NUM> wt%, of a BPA homopolycarbonate, based on the total weight of the polycarbonate composition. The BPA homopolycarbonates can have sulfur present as a contaminant in the components used in the manufacture of the BPA homopolycarbonate, i.e., the BPA monomer, endcapping agents, and the carbonate source, for example. The BPA homopolycarbonates can have a sulfur content of up to <NUM> ppm, up to <NUM> ppm, up to <NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, each based on the total weight of the BPA homopolycarbonate.

The BPA homopolycarbonates can comprise a phenolic endcap content of level less than or equal to less than <NUM> ppm, of less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm, or less than or equal to <NUM> ppm; a carbamate endcap content of less than <NUM> ppm, or less than <NUM> ppm, or less than <NUM> ppm; or a combination thereof, each based on the total weight of the BPA homopolycarbonate. The phenolic endcap content and the carbamate endcap content was determined by phosphorous nuclear magnetic resonance analysis (<NUM>P-NMR).

When present, he BPA homopolycarbonate can be a linear BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da, or <NUM>,<NUM>-<NUM>,<NUM> Da, or <NUM>,<NUM>-<NUM>,<NUM> Da, as measured by GPC, using a crosslinked styrene-divinylbenzene column and calibrated to BPA homopolycarbonate references. GPC samples can be prepared at a concentration of <NUM> per ml and eluted at a flow rate of <NUM> per minute. More than one BPA homopolycarbonate can be present. For example, the polycarbonate compositions can comprise a first BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da and a second BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da, or a second BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da, each measured by GPC using BPA homopolycarbonate standards. The weight ratio of the first BPA homopolycarbonate relative to the second BPA homopolycarbonate can be <NUM>:<NUM>-<NUM>:<NUM>, or <NUM>:<NUM>-<NUM>: <NUM>, or <NUM>:<NUM>-<NUM>:<NUM> or <NUM>:<NUM>-<NUM>:<NUM>.

Advantageously, in contrast to the teachings of the prior art, the inventors have found that the aryl benzofuranone stabilizer of the polycarbonate compositions can reduce the yellowness that occurs initially and after aging. Indeed, yellowness after aging can be reduced in polycarbonate compositions even when sulfur is present as a contaminant in the components used in the manufacture of the high heat copolycarbonates and the homopolycarbonates, i.e., the high heat aromatic dihydroxy monomer, the low heat aromatic dihydroxy monomer, endcapping agents, and the carbonate source, for example. Further, the polycarbonate compositions having an aryl benzofuranone stabilizer can reduce the yellowness that occurs after aging for compositions when a sulfur-containing stabilizer or an organosulfonic stabilizer is present.

The polycarbonate compositions include an arylbenzofuranone stabilizer. The arylbenzofuranone stabilizer can have the formula
<CHM>
wherein Rq, Rr, and Rs, are each independently C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> alkoxy, -OH, -SH, -NH<NUM>, (C<NUM>-C<NUM>alkyl)amino, di(C<NUM>-C<NUM>alkyl)amino,-OP(=O)(ORt)<NUM>, -OP(ORt)<NUM>, -P(=O)(Rt)(ORt), -OP(=O)(Rt)<NUM>, -P(=O)(Rt)<NUM>, -P(Rt)<NUM>, wherein each instance of Rt is independently C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl; q, r, and s are each independently <NUM>-<NUM>. In some aspects, a phosphorous-carbon bond, a phosphorous-oxygen bond, or a combination thereof is present.

In some aspects, the arylbenzofuranone stabilizer has the formula
<CHM>
wherein Rq, Rr, and Rt, are each independently C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, or C<NUM>-<NUM> alkoxy, each optionally substituted with halogen, -OH, -SH, -NH<NUM>, (C<NUM>-C<NUM>alkyl)amino, di(C<NUM>-C<NUM>alkyl)amino; -OP(=O)(ORt)<NUM>, -OP(ORt)<NUM>, -P(=O)(Rt)(ORt), -OP(=O)( Rt)<NUM>, -P(=O)(Rt)<NUM>, -P(Rt)<NUM>, wherein each instance of Rt is independently C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl; q and r are each independently <NUM>-<NUM>. In some aspects a phosphorous-carbon bond, a phosphorous-oxygen bond, or a combination thereof is present.

The arylbenzofuranone stabilizer can be present from greater than <NUM> to <NUM> ppm, from greater than <NUM> to <NUM> ppm, from greater than <NUM> to <NUM> ppm, from greater than <NUM> to <NUM> ppm, from greater than <NUM> to less than <NUM> ppm, greater than <NUM> to less than <NUM> ppm, greater than <NUM> to less than <NUM> ppm, greater than <NUM> to less than <NUM> ppm, greater than <NUM> to less than <NUM> ppm, greater than <NUM> to less than <NUM> ppm, from <NUM> to <NUM> ppm, from <NUM> to <NUM> ppm, from <NUM> to <NUM> ppm, or from <NUM> to <NUM> ppm, each based on the total weight of the composition.

The polycarbonate compositions can further comprise a sulfur-containing stabilizer compound. In some aspects, the sulfur-containing stabilizer compound comprises a saturated or unsaturated C<NUM>-<NUM> hydrocarbon chain, or a saturated or unsaturated, branched or unbranched C<NUM>-<NUM> hydrocarbon chain. Unsaturated hydrocarbon chains can include <NUM> or more degrees of unsaturation (alkene or alkyne), for example <NUM>, <NUM>, <NUM>, or <NUM> degrees of unsaturation. The hydrocarbon chain preferably is unbranched. Preferably the C<NUM>-<NUM> hydrocarbon chain or C<NUM>-<NUM> hydrocarbon chain is a linear alkyl group.

The sulfur-containing stabilizer compound can include a thioether carboxy compound of formula (<NUM>)
<CHM>
wherein L is a C<NUM>-<NUM> aliphatic or aromatic linking group; R is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene; and R<NUM> is a hydrogen, C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> alkylarylene, or C<NUM>-<NUM> arylalkylene. In an aspect, L is a C<NUM>-<NUM> aliphatic or C<NUM> aromatic linking group; R is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene, and Ra is hydrogen, C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> alkylarylene, or a C<NUM>-<NUM> arylalkylene. In a preferred aspect, L is a C<NUM>-<NUM> alkylene or C<NUM>-<NUM> arylene; R is C<NUM>-<NUM> alkyl; and Ra is C<NUM>-<NUM> alkyl.

In some aspects, the sulfur-containing stabilizer compound is of formula <NUM>(a)
<CHM>
wherein R<NUM> is a hydrogen, C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene, and each g is independently the same or different and is <NUM>-<NUM>, provided that R<NUM> has <NUM>-<NUM> or <NUM>-<NUM> carbon atoms or g is <NUM>-<NUM> or <NUM>-<NUM>. In an aspect, each R<NUM> a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, or C<NUM>-<NUM> alkynyl, and each g is independently the same or different and is <NUM>-<NUM>. In a preferred aspect, R<NUM> is a linear C<NUM>-<NUM> or C<NUM>-<NUM> alkyl group and g is <NUM>-<NUM>, or <NUM>, <NUM>, or <NUM>.

In other aspects, the sulfur-containing stabilizer compound can be a thioether dicarboxy compound formula (<NUM>)
<CHM>
wherein each R<NUM> is independently the same or different and is a hydrogen, C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene; and each L is independently the same or different and is a C<NUM>-<NUM> aliphatic or aromatic linking group. In an aspect, each R<NUM> is independently the same or different and is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene, and each L is independently the same or different and is a C<NUM>-<NUM> aliphatic or C<NUM> aromatic linking group.

In some aspects, at least one of the R<NUM> groups of formula (<NUM>) is a saturated or unsaturated, branched or unbranched C<NUM>-<NUM> hydrocarbon chain, or a saturated or unsaturated, branched or unbranched C<NUM>-<NUM> hydrocarbon chain as described above. The hydrocarbon chain preferably is unbranched. Preferably at least one, or both, of the R<NUM> groups of formula (<NUM>) is a linear C<NUM>-<NUM> or C<NUM>-<NUM> alkyl group. In this aspect the other of the R<NUM> groups can be C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene. Alternatively in this aspect, the other of the R<NUM> groups can be C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene.

The sulfur-containing stabilizer compound can be a thioether dicarboxy compound formula (4a)
<CHM>
wherein each R<NUM> is independently the same or different and is a hydrogen, C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene, and each g is independently the same or different and is <NUM>-<NUM>, provided that at least one R<NUM> has <NUM>-<NUM> or <NUM>-<NUM> carbon atoms or at least one g is <NUM>-<NUM> or <NUM>-<NUM>. In an aspect, each R<NUM> is independently the same or different and is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, or C<NUM>-<NUM> alkynyl, and each g is independently the same or different and is <NUM>-<NUM>. In a preferred aspect, each R<NUM> is the same, and is a linear C<NUM>-<NUM> or C<NUM>-<NUM> alkyl group and each g is the same and is <NUM>-<NUM>, or <NUM>, <NUM>, or <NUM>. Preferred sulfur-containing stabilizers of this type include dilauryl thiodipropionate, dicetyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, and ditridecyl thiodipropionate, or a combination thereof.

In a preferred aspect, the sulfur-containing stabilizer compound can be a thioether ester compound of formula (<NUM>)
<CHM>
wherein each R<NUM> is independently the same or different and is a hydrogen, C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene; and each L is independently the same or different and is a C<NUM>-<NUM> aliphatic or aromatic linking group. In an aspect, each R<NUM> is independently the same or different and is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene, and each L is independently the same or different and is a C<NUM>-<NUM> aliphatic or a C<NUM> aromatic linking group.

In some aspects, at least one of the R<NUM> groups of formula (<NUM>) is a saturated or unsaturated, branched or unbranched C<NUM>-<NUM> hydrocarbon chain, or a saturated or unsaturated, branched or unbranched C<NUM>-<NUM> hydrocarbon chain as described above. The hydrocarbon chain preferably is unbranched. Preferably at least one, or all, of the R<NUM> groups of formula (<NUM>) is a linear C<NUM>-<NUM> or C<NUM>-<NUM> alkyl group. In this aspect the other of the R<NUM> groups can be C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene. Alternatively in this aspect, the other of the R<NUM> groups can be C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene.

In another aspect, the sulfur-containing stabilizer compound can be a thioether ester compound of formula (5a)
<CHM>
wherein each R<NUM> is independently the same or different and is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> alkynyl, C<NUM>-<NUM> cycloalkyl, C<NUM>-<NUM> cycloalkenyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> arylalkylene, or C<NUM>-<NUM> alkylarylene, G is a C<NUM>-<NUM> hydrocarbyl having a valence h, g is <NUM>-<NUM>, and h is <NUM>-<NUM>, provided that at least one R<NUM> has <NUM>-<NUM> or <NUM>-<NUM> carbon atoms or at least one g is <NUM>-<NUM> or <NUM>-<NUM>. In an aspect, each R<NUM> is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, or C<NUM>-<NUM> alkynyl, G is a C<NUM>-<NUM> alkyl having a valence h, g is <NUM>-<NUM>, or <NUM>, <NUM>, or <NUM> and h is <NUM>-<NUM>. In a preferred aspect, each R<NUM> is independently the same or different linear C<NUM>-<NUM> or C<NUM>-<NUM> alkyl group, G is a C<NUM>-<NUM> alkyl having a valence h, each g is the same and is <NUM>-<NUM>, or <NUM>-<NUM>, and h is <NUM>-<NUM>. Preferred sulfur-containing stabilizers of this type include <NUM>,<NUM>-bis[[<NUM>-(dodecylthio)-<NUM>-oxopropoxy]methyl]propane-<NUM>,<NUM>-diyl bis[<NUM>-(dodecylthio)propionate of formula (5b).

The sulfur-containing stabilizer compound can be present from <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, based on the total weight of the polycarbonate composition. In some aspects, sulfur-containing stabilizer compound can be present in an amount effective to provide <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm of added sulfur, the i.e., sulfur-containing stabilizer-added sulfur, each based on the total weight of the polycarbonate composition. As stated above, "added sulfur" (here, "sulfur-containing stabilizer-added sulfur") refers to sulfur added to the polycarbonate composition from the sulfur-containing stabilizer, and does not include any contaminant sulfur present in the high heat aromatic dihydroxy monomer, the low heat aromatic dihydroxy monomer, the endcapping agents, or the carbonate source used in manufacture of the high heat copolycarbonates. In an aspect, the sulfur-containing stabilizer compound can be absent.

In a preferred aspect, the sulfur-containing stabilizer compound is soluble in an organic solvent that also dissolves the high heat copolycarbonate, and has low solubility in an aqueous solvent at a pH of less than <NUM>. These characteristics allow the sulfur-containing stabilizer compound to be added before, during, or after manufacture of the high heat copolycarbonate, and remain with the high heat copolycarbonate compositions in the organic phase during the separation of the brine phase or the extraction of the organic phase with an acidic aqueous phase or a neutral pH aqueous phase. In an aspect, the sulfur-containing stabilizer compound can have a solubility of <NUM> in <NUM> of an organic phase solvent. The organic solvent is selected to dissolve the high heat copolycarbonate and can be a halogenated solvent such as methylene chloride, chlorobenzene, dichlorobenzene, or a combination thereof. Conversely, the sulfur-containing stabilizer can have a solubility of less than <NUM> in <NUM> of water or brine, each at a pH of less than <NUM>, or less than <NUM>. In an aspect, the sulfur-containing stabilizer compound can have a solubility of less than <NUM> ppm, or more preferably less than <NUM> ppm in the water or a brine phase.

Accordingly, he sulfur-containing stabilizer compound can be added with the monomers (in the formulation tank), supplied in the monomer composition (provided by the supplier, for example), or pumped directly to the reactor before, during, or after the polymerization reaction. The sulfur-stabilizer compound can be added to a centrifuge feed tank, concentrator, or precipitation feed, or feed tank. The sulfur-containing stabilizer compound can be added as a solid, solution, or molten.

The sulfur-containing stabilizer compound in some aspects improves the color stability of the composition after the composition is molded under aggressive conditions, e.g., at high melt temperatures, such as <NUM> or higher, or prolonged residence times during molding, such as times exceeding <NUM> or <NUM> minutes, or both. In some aspects it is possible to simultaneously improve the initial color of the polycarbonate composition and the color stability of the composition after the composition is molded under aggressive conditions, typically at high melt temperatures, such as <NUM> or higher, or prolonged residence times during molding, such as times exceeding <NUM> or <NUM> minutes, or both. However, in the absence of an aryl benzofuranone stabilizer, the color stability can deteriorate on aging.

In some aspects, the polycarbonate compositions can further include a sulfonic acid stabilizer also referred to herein as an "organosulfonic stabilizer". The organosulfonic stabilizer can be an aryl or aliphatic sulfonic acid, including a polymer thereof, an aryl or an aliphatic sulfonic acid anhydride, or an aryl or aliphatic ester of an aryl or aliphatic sulfonic acid, or a polymer thereof. In particular, the organosulfonic stabilizer is a C<NUM>-<NUM> alkyl sulfonic acid, a C<NUM>-<NUM> aryl sulfonic acid, a C<NUM>-<NUM> alkylarylene sulfonic acid, a C<NUM>-<NUM> arylalkylene sulfonic acid, or an aromatic sulfonic acid polymer; an anhydride of a C<NUM>-<NUM> alkyl sulfonic acid, a C<NUM>-<NUM> aryl sulfonic acid, a C<NUM>-<NUM> alkylarylene sulfonic acid, or a C<NUM>-<NUM> arylalkylene sulfonic acid; or a C<NUM>-<NUM> aryl ester of: a C<NUM>-<NUM> alkyl sulfonic acid, a C<NUM>-<NUM> aryl sulfonic acid, a C<NUM>-<NUM> alkylarylene sulfonic acid, a C<NUM>-<NUM> arylalkylene sulfonic acid, or an aromatic sulfonic acid polymer; or a C<NUM>-<NUM> aliphatic ester of: a C<NUM>-<NUM> alkyl sulfonic acid, a C<NUM>-<NUM> aryl sulfonic acid, a C<NUM>-<NUM> alkylarylene sulfonic acid, a C<NUM>-<NUM> arylalkylene sulfonic acid, or an aromatic sulfonic acid polymer. A combination of one or more of the foregoing can be used.

In an aspect, the organosulfonic stabilizer is of formula (<NUM>).

In formula (<NUM>), R<NUM> is each independently a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> alkylarylene, C<NUM>-<NUM> arylalkylene, or a polymer unit derived from a C<NUM>-<NUM> ethylenically unsaturated aromatic sulfonic acid or its corresponding C<NUM>-<NUM> alkyl ester. The C<NUM>-<NUM> ethylenically unsaturated aromatic sulfonic acid can be of the formula
<CHM>
wherein R<NUM> is hydrogen or methyl and R<NUM> is as defined in formula (<NUM>). Preferably the ethylenically unsaturated group and the sulfonic acid or ester group are located para on the phenyl ring.

Further in formula (<NUM>), R<NUM> is hydrogen; or R<NUM> is C<NUM>-<NUM> alkyl; or R<NUM> is a group of the formula -S(=O)<NUM>-R<NUM>. When R<NUM> is a group of the formula -S(=O)<NUM>-R<NUM>, each R<NUM> in the compound of formula (<NUM>) can be the same or different, but preferably each R<NUM> is the same.

In an aspect in formula (<NUM>), R<NUM> is a C<NUM>-<NUM> aryl, C<NUM>-<NUM> alkylarylene, or a polymer unit derived from a C<NUM>-<NUM> ethylenically unsaturated aromatic sulfonic acid or its ester; and R<NUM> is hydrogen, C<NUM>-<NUM> alkyl, or a group of the formula -S(=O)<NUM>-R<NUM> wherein R<NUM> is a C<NUM>-<NUM> aryl or C<NUM>-<NUM> alkylarylene. In another aspect in formula (<NUM>), R<NUM> is a C<NUM>-<NUM> alkylarylene or a polymer unit derived from a C<NUM>-<NUM> ethylenically unsaturated aromatic sulfonic acid, and R<NUM> is a hydrogen, C<NUM>-<NUM> alkyl, or a group of the formula -S(=O)<NUM>-R<NUM> wherein R<NUM> is a C<NUM>-<NUM> alkylarylene. In still another aspect, R<NUM> is a C<NUM>-<NUM> alkylarylene and R<NUM> is a hydrogen or C<NUM>-<NUM> alkyl. In still another aspect, R<NUM> is a C<NUM>-<NUM> alkylarylene and R<NUM> is a hydrogen or C<NUM>-<NUM> alkyl, or R<NUM> is a C<NUM>-<NUM> alkyl. In another aspect, R<NUM> is a polymer unit derived from a C<NUM>-<NUM> ethylenically unsaturated aromatic sulfonic acid, preferably p-styrene sulfonic acid or para-methyl styrene sulfonic acid, such that in formula (<NUM>) R<NUM> is hydrogen.

The organosulfonic stabilizer can be a C<NUM>-<NUM> alkyl ester of a C<NUM>-<NUM> alkylarylene sulfonic acid, preferably of p-toluene sulfonic acid. More preferably the stabilizer is a C<NUM>-<NUM> alkyl ester of p-toluene sulfonic acid, such as butyl tosylate. In another aspect, the organosulfonic stabilizer is an anhydride of a C<NUM>-<NUM> alkylarylene sulfonic acid, preferably para-toluene sulfonic anhydride. In still another aspect, R<NUM> is a C<NUM>-<NUM> alkylarylene sulfonic acid, and R<NUM> is hydrogen. Alternatively, R<NUM> is a C<NUM>-<NUM> alkylarylene sulfonic acid, and R<NUM> is hydrogen.

In an aspect, the sulfonic acid stabilizer is absent. When present, the organosulfonic stabilizer is present from <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, each based on the total weight of the polycarbonate composition. In some aspects, the organosulfonic acid stabilizer is present in an amount effective to provide <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM>, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, <NUM>-<NUM> ppm, or <NUM>-<NUM> ppm of added sulfur i.e., organosulfonic stabilizer-added sulfur, each based on the total weight of the polycarbonate composition.

In addition to the sulfur-containing stabilizer compound, in some aspects, a sulfur-containing agent can be present during manufacture of the high heat copolycarbonate, in particular those including C<NUM>-<NUM> alkyl substituents. In some aspects the sulfur-containing agent can provide improved mold release properties. The sulfur-containing agent can be of formula (A)
<CHM>
wherein G is leaving group, L is a C<NUM>-<NUM> aliphatic or aromatic linking group, and R is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or C<NUM>-<NUM> alkylarylene, preferably a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or a C<NUM>-<NUM> arylalkylene. Preferably R is a C<NUM>-<NUM> alkyl. For example, G can be a halide, a hydroxy group (-OH), or a salt of a hydroxy group. For example, the salt can be an alkali metal or alkaline-earth metal salt, an ammonium salt, or the like. In another aspect, G of formula (A) can be of the formula -ORa and the sulfur-containing agent can be of formula (A1)
<CHM>
wherein Ra is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, C<NUM>-<NUM> alkylarylene, or C<NUM>-<NUM> arylalkylene, and L and R are defined in formula (A). Preferably Ra is C<NUM>-<NUM> alkyl, and R is a C<NUM>-<NUM> alkyl.

The sulfur-containing agent can be of formula (A2), (A3), or a combination thereof
<CHM>
wherein R is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or C<NUM>-<NUM> arylalkylene, preferably a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or a C<NUM>-<NUM> arylalkylene, b is <NUM>-<NUM>, preferably <NUM>-<NUM>, and G is as defined in formula (A). In an aspect R is C<NUM>-<NUM> alkyl, b is <NUM>-<NUM>, preferably <NUM>-<NUM>, and G is hydrogen or Ra as defined in formula A1, preferably C<NUM>-<NUM> alkyl.

For example, the sulfur-containing agent can be of formulas (B1) to (B5)
<CHM>
<CHM>
<CHM>
or a combination thereof.

More than one sulfur-containing agent can be used, such as <NUM>, <NUM>, or <NUM> or more different sulfur-containing agents. When the sulfur-containing agent is used, the high heat copolycarbonate further comprises thioether carbonyl functional groups (e.g., pendant groups, end groups, or a combination thereof) of the formula -C(=O)-L-S-R, wherein L is a C<NUM>-<NUM> aliphatic or aromatic linking group and R is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or C<NUM>-<NUM> arylalkylene. The thioether carbonyl functional groups can be of the formula
<CHM>
or a combination thereof, wherein R is a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or C<NUM>-<NUM> arylalkylene, preferably a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> aryl, or a C<NUM>-<NUM> arylalkylene, and b is <NUM>-<NUM>, preferably <NUM>-<NUM>. In a preferred aspect, the thioether carbonyl functional groups are incorporated as endgroups.

In another preferred aspect, the thioether carbonyl functional groups are of the formula
<CHM>
<CHM>
or a combination thereof.

When the thioether carbonyl functional groups are present, the amount of the sulfur-containing agent used can be an amount effective for the thioether carbonyl functional groups to provide <NUM>-<NUM> ppm, preferably <NUM>-<NUM> ppm, more preferably <NUM>-<NUM> ppm of added sulfur, i.e., thioether carbonyl functional group-added sulfur, in the high heat copolycarbonates, each based on the total parts by weight of the high heat copolycarbonate.

The polycarbonate compositions can further include a BPA homopolycarbonate. The BPA homopolycarbonate can be linear and have an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da, or <NUM>,<NUM>-<NUM>,<NUM> Da, or <NUM>,<NUM>-<NUM>,<NUM> Da, as measured by GPC, using a crosslinked styrene-divinylbenzene column and calibrated to BPA homopolycarbonate references. GPC samples can be prepared at a concentration of <NUM> per ml and eluted at a flow rate of <NUM> per minute. More than one BPA homopolycarbonate can be present. For example, the polycarbonate compositions can comprise a first BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da and a second BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da, or a second BPA homopolycarbonate having an Mw of <NUM>,<NUM>-<NUM>,<NUM> Da, each measured by GPC using BPA homopolycarbonate standards. The weight ratio of the first BPA homopolycarbonate relative to the second BPA homopolycarbonate can be <NUM>:<NUM>-<NUM>:<NUM>, or <NUM>:<NUM>-<NUM>: <NUM>, or <NUM>:<NUM>-<NUM>:<NUM> or <NUM>:<NUM>-<NUM>:<NUM>.

The polycarbonate compositions can include various other additives ordinarily incorporated into polycarbonate compositions, with the proviso that the additive(s) are selected so as to not significantly adversely affect the desired properties of the polycarbonate composition, in particular melt flow, optical clarity, and thermal properties. Such additives can be mixed at a suitable time during the mixing of the components for forming the composition. Additives include antioxidants, heat stabilizers, light stabilizers, ultraviolet (UV) light stabilizers, plasticizers, lubricants, mold release agents, antistatic agents, colorants such as organic dyes, surface effect additives, radiation stabilizers, flame retardants, anti-drip agents, and impact modifiers. In an aspect, the polycarbonate composition further comprises a processing aid, an antioxidant or a heat stabilizer, an ultraviolet light absorber, a colorant, a flame retardant, an impact modifier, or a combination thereof. A combination of additives can be used, for example a combination of a heat stabilizer, mold release agent, and ultraviolet light stabilizer. In general, the additives are used in the amounts generally known to be effective. For example, the total amount of the additives (other than any impact modifier, filler, or reinforcing agents) can be <NUM>-<NUM> wt% or <NUM>-<NUM> wt%, based on the total weight of the polycarbonate composition, excluding any filler.

Antioxidant additives include organophosphites such as tris(nonyl phenyl)phosphite, tris(<NUM>,<NUM>-di-t-butylphenyl)phosphite, bis(<NUM>,<NUM>-di-t-butylphenyl)pentaerythritol diphosphite, distearyl pentaerythritol diphosphite or the like; alkylated monophenols or polyphenols; alkylated reaction products of polyphenols with dienes, such as tetrakis[methylene(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyhydrocinnamate)] methane, or the like; butylated reaction products of para-cresol or dicyclopentadiene; alkylated hydroquinones; hydroxylated thiodiphenyl ethers; alkylidene-bisphenols; benzyl compounds; esters of beta-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of beta-(<NUM>-tert-butyl-<NUM>-hydroxy-<NUM>-methylphenyl)-propionic acid with monohydric or polyhydric alcohols; esters of thioalkyl or thioaryl compounds such as distearylthiopropionate, dilaurylthiopropionate, ditridecylthiodipropionate, octadecyl-<NUM>-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)propionate, pentaerythrityl-tetrakis[<NUM>-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)propionate or the like; amides of beta-(<NUM>,<NUM>-di-tert-butyl-<NUM>-hydroxyphenyl)-propionic acid or the like, or a combination thereof. Antioxidants are generally used in amounts ranging from <NUM>-<NUM> parts per million (ppm).

Colorants such as pigment or dye additives can also be present. Useful pigments can include, for example, inorganic pigments such as metal oxides and mixed metal oxides such as zinc oxide, titanium dioxides, iron oxides, or the like; sulfides such as zinc sulfides, or the like; aluminates; sodium sulfo-silicates sulfates, chromates, or the like; carbon blacks; zinc ferrites; ultramarine blue; organic pigments such as azos, di-azos, quinacridones, perylenes, naphthalene tetracarboxylic acids, flavanthrones, isoindolinones, tetrachloroisoindolinones, anthraquinones, enthrones, dioxazines, phthalocyanines, and azo lakes; Pigment Red <NUM>, Pigment Red <NUM>, Pigment Red <NUM>, Pigment Red <NUM>, Pigment Red <NUM>, Pigment Red <NUM>, Pigment Violet <NUM>, Pigment Blue <NUM>, Pigment Blue <NUM>, Pigment Green <NUM>, Pigment Yellow <NUM>, Pigment Yellow <NUM>, Pigment Yellow <NUM>, and Pigment Brown <NUM>; or a combination thereof.

In some aspects, the polycarbonate composition includes a colorant comprising Solvent Green <NUM>, Solvent Green <NUM>, Solvent Green <NUM>, Pigment Green <NUM>, Pigment Green <NUM>, Solvent Red <NUM>, Solvent Red <NUM>, Solvent Red <NUM>, Solvent Red <NUM>, Solvent Red <NUM>, Solvent Red <NUM>, Solvent Red <NUM>, Pigment Red <NUM>, Disperse Red <NUM>, VatRed <NUM>, Solvent Orange <NUM>, Solvent Orange <NUM>, Disperse Orange <NUM>, Solvent Violet <NUM>, Solvent Violet <NUM>, Solvent Violet <NUM>, Solvent Violet <NUM>, Disperse Violet <NUM>/<NUM>, Pigment Blue <NUM>, Pigment Blue <NUM>, Copper phthalocyanine Pigment Blue <NUM>, Disperse Blue <NUM>, Solvent Blue <NUM>, Solvent Blue <NUM>, Solvent Blue <NUM>, Solvent Blue <NUM>, Solvent Blue <NUM>, Pigment Yellow <NUM>, Pigment Yellow <NUM>, Pigment Yellow <NUM>, Disperse Yellow <NUM>, Solvent Yellow <NUM>, Solvent Yellow <NUM>, Solvent Yellow <NUM>, Solvent Yellow <NUM>, Solvent Yellow <NUM>, Solvent Yellow <NUM>:<NUM>, Solvent Yellow <NUM>, or a combination thereof; preferably Solvent Red <NUM>, Solvent Red <NUM>, or a combination thereof. In some aspects, no colorant is preferred.

The polycarbonate compositions can be manufactured by various methods known in the art. For example, powdered copolycarbonate, and other optional components are first blended, optionally with any fillers, in a high-speed mixer or by hand mixing. The blend is then fed into the throat of a twin-screw extruder via a hopper. Alternatively, at least one of the components can be incorporated into the composition by feeding it directly into the extruder at the throat or downstream through a sidestuffer, or by being compounded into a masterbatch with a desired polymer and fed into the extruder. The extruder is generally operated at a temperature higher than that necessary to cause the composition to flow. The extrudate can be immediately quenched in a water bath and pelletized. The pellets so prepared can be one-fourth inch long or less as desired. Such pellets can be used for subsequent molding, shaping, or forming.

A molded sample of the composition having a thickness of <NUM> millimeters and aged for <NUM> hours at <NUM> can have a change in a yellowness index value of less than <NUM>, or less than <NUM>, or less than <NUM> as compared with an initial yellowness index value of the molded sample, as measured in accordance with ASTM D1925.

The thermoplastic compositions can be used in articles including a molded article, a thermoformed article, an extruded film, an extruded sheet, one or more layers of a multi-layer article, a substrate for a coated article, or a substrate for a metallized article. Optionally, the article has no significant part distortion or discoloration when the article is subjected to a secondary operation such as over-molding, lead-free soldering, wave soldering, low temperature soldering, or coating, or a combination thereof. The articles can be partially or completely coated with, e.g., a hard coat, a UV protective coat, an anti-refractive coat, an anti-reflective coat, a scratch resistant coat, or a combination thereof, or metallized.

Exemplary articles include a lens, a light guide, a waveguide, a collimator, an optical fiber, a window, a door, a visor, a display screen, an electronic device, a scientific or medical device, an autoclavable article, a safety shield, a fire shield, wire or cable sheathing, a mold, a dish, a tray, a screen, an enclosure, glazing, packaging, a gas barrier, an anti-fog layer, or an anti-reflective layer.

The following components shown in table <NUM> are used in the examples. Unless specifically indicated otherwise, the amount of each component is in weight percent (wt%), based on the total weight of the composition. Examples of the invention are designated by numbers, comparative example by letters.

All polycarbonate compositions except where indicated are compounded on a Werner & Pfleiderer co-rotating twin screw extruder (Length/Diameter (L/D) ratio = <NUM>/<NUM>, vacuum port located near die face). The twin-screw extruder had enough distributive and dispersive mixing elements to produce good mixing between the polymer compositions. The compositions are subsequently molded according to ISO <NUM> on a Husky or BOY injection-molding machine. Compositions are compounded and molded at a temperature of <NUM>-<NUM>, though it will be recognized by one skilled in the art that the method cannot be limited to these temperatures.

Physical measurements were made using the tests and test methods described below. The testing samples were prepared as described below and the following test methods were used.

Yellowness Index (YI) before and after aging for <NUM> hours at <NUM> in air was measured on <NUM> millimeter samples in accordance with ASTM D1925.

Polymer molecular weights [weight average (Mw)] were determined using gel permeation chromatography (GPC) as per ASTM method D5296-<NUM>. Polycarbonate standards were used for calibration, methylene chloride was used as the solvent.

Glass transition temperatures were measured using differential scanning calorimetry (DSC) was run as per ASTM method D3418-<NUM>, but using a <NUM>/min heating rate and recorded on the second heat.

Polydispersivity Index (PDI) was calculated as the ratio of weight average (Mw) and number average (Mn) molecular weights.

Phosphorus <NUM> nuclear magnetic resonance (<NUM>P NMR) analysis, using phosphorous functionalization of the polycarbonate phenolic end groups, was used to characterize the resins. A sample was dissolved in CDCl<NUM> with pyridine and chromium (III) AcAc (acetylacetonate); trichloro phenol was used as a standard. The active phosphorylating agent, which derivatized the phenolic end group functionality into phosphorous containing species, was o-phenylene, phosphorochloridite (<NPL>). The resin solutions were allowed to react for at least <NUM> minutes, converted into their phosphorus derivatives and analyzed by NMR. Phosphorus <NUM> isotope signals were observed and quantified vs. the trichloro phenol standard. The phenolic end group chemical shifts were from <NUM> to <NUM> ppm for BPA or BPI units. None of the resins have more than <NUM> ppm carbamate end groups.

Table <NUM> shows the compositions and properties for Comparative Examples A-D and Examples <NUM>-<NUM>.

Table <NUM> shows the effect of the presence of aryl benzofuranone (Stab-<NUM>) and sulfur-containing stabilizer compound (Stab-<NUM>) on the YI values for mixtures of BPI-BPA copolymer (BPI-BPA-<NUM>) and bisphenol A homopolycarbonate (PC1). Added sulfur-containing stabilizer compound (Stab-<NUM>) can provide a small but measurable improvement in initial YI compared with compositions wherein Stab-<NUM> is absent (compare Comparative Examples A and B with Comparative Examples C and D). In addition, Comparative Examples A and B. wherein both the aryl benzofuranone (Stab-<NUM>) and Stab-<NUM> were absent resulted in a significant increase in YI (i.e., from <NUM>-<NUM> and <NUM>-<NUM>, respectively) after heat aging. However, Comparative Examples C and D, wherein Stab-<NUM> was present, but Stab-<NUM> was absent, showed an even larger increase in YI on aging (compare Comparative Examples C and D with Comparative Examples A and B).

Examples <NUM> and <NUM>, wherein aryl benzofuranone (Stab-<NUM>) was present (<NUM> and <NUM> ppm, respectively) and sulfur-containing stabilizer compound (Stab-<NUM>) was absent, showed a dramatic decrease in delta YI on heat aging as compared with Comparative Examples A and B. Examples <NUM>-<NUM> having a combination of Stab-<NUM> and Stab-<NUM> demonstrate a reduction in both the initial YI and the delta YI on heat aging. This is an advantage, at least because it is costly and commercially impractical to completely remove all the sulfur impurities from the various bisphenol monomers used in the synthesis of the polycarbonates. Thus, the use of an aryl benzofuranone (Stab-<NUM>) allows for the use of monomers containing sulfur impurities while achieving improved long-term color stability, in particular greatly reduced color shift on aging.

Table <NUM> shows the compositions and properties for Comparative Examples E-J and Examples <NUM>-<NUM>.

Table <NUM> shows the effect of the presence of aryl benzofuranone (Stab-<NUM>) and/or sulfur-containing stabilizer compound (Stab-<NUM>) and/or an organosulfonic acid stabilizer (Stab-<NUM>) on the YI values for compositions including a BPI-BPA copolymer (BPI-BPA-<NUM>), wherein BPI-BPA-<NUM> has variable sulfur content. In compositions wherein BPI-BPA-<NUM> contains <NUM> ppm sulfur, the addition of organosulfonic acid stabilizer butyl tosylate (Stab-<NUM>) resulted in no improvement in initial YI values (Comparative Examples E and F). Example <NUM>, wherein the BPI-BPA had <NUM> ppm sulfur content and Stab-<NUM> (<NUM> ppm) and organosulfonic acid stabilizer butyl tosylate (Stab-<NUM>, <NUM> ppm) were both present showed an increase in the initial YI and an improved ΔYI after aging compared to Comparative Example H (<NUM> versus <NUM>, respectively). Incorporating sulfur-containing stabilizer compound (Stab-<NUM>) and decreasing the loading of Stab-<NUM> to <NUM> ppm in a composition wherein BPI-BPA had <NUM> ppm sulfur content, resulted in a similar initial YI and an improved ΔYI (compare Example <NUM> with Example <NUM>). Incorporating sulfur-containing stabilizer compound (Stab-<NUM>) and Stab-<NUM> (<NUM> ppm loading) in a composition wherein BPI-BPA had a higher sulfur content (<NUM> ppm), resulted in an increase initial YI and an improved ΔYI (compare Example <NUM> with Comparative Example J).

Table <NUM> shows the compositions and properties for Comparative Example K and Examples <NUM>-<NUM>.

Table <NUM> shows the effect of the loading amount of arylbenzofuranone (Stab-<NUM>) on compositions that include BPI-BPA-<NUM> having <NUM> ppm sulfur content, and a combination of sulfur-containing stabilizer compound and an organosulfonic acid stabilizer (<NUM> ppm Stab-<NUM> and <NUM> ppm Stab-<NUM>). Example <NUM> shows that <NUM> ppm Stab-<NUM> provides results similar to Comparative Example K, where Stab-<NUM> was absent. Example <NUM> (<NUM> ppm) shows the most improved ΔYI after aging, while increasing the loading to <NUM> ppm resulted in an increase in ΔYI after aging (compare Example <NUM> with <NUM>). Further increasing the loading to <NUM> ppm failed to improve the ΔYI after aging (see Example <NUM>).

Table <NUM> shows the compositions and properties for Comparative Examples L-M and Examples <NUM>-<NUM>.

Table <NUM> shows the effect of the addition of aryl benzofuranone (Stab-<NUM>) and/or a sulfur-containing stabilizer compound and/or an organosulfonic acid stabilizer (Stab-<NUM> and/or Stab-<NUM>) on compositions that include PPP-BPI-BPA as the high heat copolycarbonate. Example <NUM> shows that the addition of Stab-<NUM> to a composition having organosulfonic acid stabilizer (Stab-<NUM>) resulted in no change to the initial YI and a dramatic improvement in ΔYI after aging (compare with Comparative Example L). Example <NUM> shows that the addition of Stab-<NUM> to a composition having a combination of sulfur-containing stabilizer compound and an organosulfonic acid stabilizer (i.e., Stab-<NUM> and Stab-<NUM>) resulted in an increased initial YI and a dramatic improvement in ΔYI after aging (compare with Comparative Example M).

Table <NUM> shows the compositions and properties for Comparative Example N and Examples <NUM>-<NUM>.

Table <NUM> shows the effect of the addition of sulfur-containing stabilizer compound and/or an organosulfonic acid stabilizer (Stab-<NUM> and/or Stab-<NUM>) on compositions that include PPP-BPA as the high heat copolycarbonate. The addition of Stab-<NUM> in the absence of either sulfur-containing stabilizer compound or an organosulfonic acid stabilizer (i.e., Stab-<NUM> or Stab-<NUM>) resulted in an increased initial YI and an improved ΔYI after aging as compared to a composition having Stab-<NUM> wherein Stab-<NUM> was absent (compare Example <NUM> with Comparative Example N). The combination of Stab-<NUM> and Stab-<NUM> demonstrated a further improvement in ΔYI after aging (compare Exampled <NUM> with Example <NUM>).

Table <NUM> shows the compositions and properties for Comparative Examples O-Q and Examples <NUM>-<NUM>.

Table <NUM> shows the effect of the addition of different aryl benzofuranones (Stab-<NUM> or Stab-<NUM>) on the properties of compositions that include a combination of sulfur-containing stabilizer compound and an organosulfonic acid stabilizer (Stab-<NUM> and Stab-<NUM>). Examples <NUM>-<NUM>, wherein BPI-BPA is the high heat copolycarbonate, both Stab-<NUM> and Stab-<NUM> improved the ΔYI after aging (compare with Comparative Example O). Examples <NUM>-<NUM>, wherein PPP-BPI-BPA is the high heat copolycarbonate, both Stab-<NUM> and Stab-<NUM> improved the ΔYI after aging (compare with Comparative Example P). Examples <NUM>-<NUM>, wherein PPP-BPA is the high heat copolycarbonate, both Stab-<NUM> and Stab-<NUM> improved the ΔYI after aging (compare with Comparative Example Q). Comparison of Examples <NUM>, <NUM>, and <NUM> with Examples <NUM>, <NUM>, and <NUM> clearly shows that Stab-<NUM> was superior to Stab-<NUM>, resulting in dramatic improvements to the ΔYI after aging.

All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of "up to <NUM> wt%, or, more specifically, <NUM> wt% to <NUM> wt%", is inclusive of the endpoints and all intermediate values of the ranges of "<NUM> wt% to <NUM> wt%," etc.). "Combinations" is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms "first," "second," and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a" and "an" and "the" do not denote a limitation of quantity and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. "Or" means "and/or" unless clearly stated otherwise. Reference throughout the specification to "some embodiments", "an embodiment", and so forth, means that a particular element described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments. A "combination thereof" is open and includes any combination comprising at least one of the listed components or properties optionally together with a like or equivalent component or property not listed.

Claim 1:
A polycarbonate composition comprising:
a high heat copolycarbonate comprising
high heat carbonate units, wherein a homopolycarbonate of the high heat carbonate units has a glass transition temperature of <NUM>-<NUM> as determined by differential scanning calorimetry as per ASTM D3418 with a heating rate <NUM>/min and wherein the high heat carbonate units comprise formula
<CHM>
or a combination of formula
<CHM>
and formula
<CHM>
wherein
Ra and Rb are each independently C<NUM>-<NUM> alkyl, Rg is C<NUM>-<NUM> alkyl, p and q are each independently <NUM>-<NUM>, and t is <NUM>-<NUM>;
Rc and Rd are each independently a C<NUM>-<NUM> alkyl, C<NUM>-<NUM> alkenyl, C<NUM>-<NUM> cycloalkyl, or C<NUM>-<NUM> alkoxy, m and n are each independently <NUM>-<NUM>, each R<NUM> is independently C<NUM>-<NUM> alkyl or hydrogen, R<NUM> is C<NUM>-<NUM> alkyl or phenyl optionally substituted with <NUM>-<NUM> C<NUM>-<NUM> alkyl groups, and g is <NUM>-<NUM>; and
optionally low heat carbonate units, wherein a homopolycarbonate of the low heat carbonate units has a glass transition temperature of up to <NUM> as determined by differential scanning calorimetry as per ASTM D3418 with heating rate of <NUM>/min; and
greater than <NUM> to <NUM> ppm of an aryl benzofuranone stabilizer;
optionally, <NUM>-<NUM> ppm of a sulfur-containing stabilizer compound;
optionally, <NUM>-<NUM> ppm of an organosulfonic stabilizer;
optionally, a bisphenol A homopolycarbonate;
each based on the total parts by weight of the composition,
wherein a molded sample of the composition having a thickness of <NUM> millimeters and aged for <NUM> hours at <NUM> has a change in a yellowness index value of less than <NUM>, or less than <NUM>, or less than <NUM> as compared with an initial yellowness index value of the molded sample, as measured in accordance with ASTM D1925.