EP3063203A2

EP3063203A2 - Method of adding a catalyst in a melt polymerization process and the polycarbonate polymerized therefrom

Info

Publication number: EP3063203A2
Application number: EP14806084.1A
Authority: EP
Inventors: Ignacio Vic Fernandez; Jorge A. Garcia AGUDO; Aaron David BORJARSKI
Original assignee: SABIC Global Technologies BV
Current assignee: SABIC Global Technologies BV
Priority date: 2013-10-28
Filing date: 2014-10-28
Publication date: 2016-09-07
Also published as: WO2015063686A2; CN105873981A; WO2015063686A3; KR20160079772A

Abstract

In an embodiment, a process of preparing a reduced activity first catalyst comprises preparing an aqueous solution I comprising a first catalyst I; preparing an aqueous solution I comprising a first catalyst II; combining the solution I and the solution II to form a solution III comprising the reduced activity first catalyst. In another embodiment, a process of preparing a polycarbonate comprises polymerizing reactants in the presence of a catalyst comprising one or both of the reduced activity first catalyst and a second catalyst, wherein the second catalyst is one or both of a high temperature second catalyst or a second catalyst with a reduced metal content.

Description

METHOD OF ADDING A CATALYST IN A MELT POLYMERIZATION PROCESS AND THE POLYCARBONATE POLYMERIZED THEREFROM

TECHNICAL FIELD

[0001] This application relates to a melt polymerization and polycarbonates made therefrom.

BACKGROUND

[0002] The melt polycarbonate process is based on the continuous reaction of a dihydroxy compound and a carbonate source in molten stage. The reaction can occur in a series of reactors where the combined effect of catalyst, temperature, vacuum, and agitation allows for monomer reaction and removal of reaction by-products to displace the reaction equilibrium and make the polymer chain grow. A common polycarbonate that is made in melt polymerization reactions is that derived from bisphenol A (BPA) via reaction with diphenyl carbonate (DPC). This reaction can be catalyzed by tetramethyl ammonium hydroxide (TMAOH), which can be added in to a monomer mixture prior to being introduced to a first polymerization unit and sodium hydroxide (NaOH), which can be added to the first reactor or upstream of the first reactor and after a monomer mixer.

[0003] Apart from the main polymerization reaction, there is a series of side reactions consisting of chain rearrangements of the polymer backbone that lead to branching that are often referred to as Fries rearrangement. The Fries species specifically found in bisphenol A melt polycarbonates are the ester type of structures A, B, and C.

A. Linear Fries:

B. Branched Fries:

Fries reaction is induced by the combined effect of basic catalysts, temperature, and residence time, which makes the melt-produced polycarbonates inherently branched as compared with the interfacial polycarbonates since their manufacturing temperatures are lower.

[0004] Since high branching levels in the resin can have a negative effect on the mechanical properties of the polycarbonate (for example, on impact strength) and as some of the intermediate species formed during the Fries rearrangement process can be involved in the formation of color bodies, a polycondensation catalyst with better selectivity (less Fries promotion) is needed.

BRIEF DESCRIPTION

[0005] Disclosed herein is a transesterification catalyst, a melt polycarbonate, and methods for making.

[0006] In an embodiment, a process of preparing a reduced activity first catalyst comprises preparing an aqueous solution I comprising a first catalyst I; preparing an aqueous solution I comprising a first catalyst II; and combining the solution I and the solution II to form a solution III comprising the reduced activity first catalyst.

[0007] In another embodiment, a process of preparing a reduced activity first catalyst comprises preparing an aqueous solution I comprising NaOH; preparing an aqueous solution II comprising KH₂P0₄; and combining the solution I and the solution II to form a solution III comprising the reduced activity first catalyst comprising KNaHP0₄, wherein a molar ratio of Na to K is 0.5 to 2.

[0008] In an embodiment, a melt polymerization process comprises melt

polymerizing a dihydroxy compound and a carbonate compound in a polymerization unit to form polycarbonate, wherein the melt polymerizing comprises adding solution III of any of the preceding claims and a second catalyst to the melt polymerization process, wherein the polycarbonate has a branching level of less than or equal to 900 ppm.

[0009] In another embodiment, a melt polymerization process comprises melt polymerizing a dihydroxy compound and a carbonate compound in the presence of a catalyst composition to form a polycarbonate, wherein the catalyst composition comprises a second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing, wherein the polycarbonate has a branching level of less than or equal to 900 ppm.

[0010] In still another embodiment, a melt polymerization process comprises melt polymerizing a dihydroxy compound and a carbonate compound in a polymerization unit in the presence of a catalyst composition to form polymerized polycarbonate, wherein the catalyst composition comprises a second catalyst; wherein the second catalyst comprises a metal compound, wherein the metal comprises at least one of sodium, potassium, and cesium; wherein if the compound comprises sodium sulfate, the amount of sodium is 0 to 1,690 ppm; if the compound comprises cesium sulfate, the amount of cesium is 0 to 275 ppm; if the compound comprises sodium hydroxide, the amount of sodium is 0 to 35 ppm; if the compound comprises potassium hydroxide, the amount of potassium is 0 to 50 ppm; if the compound comprises cesium hydroxide, the amount of cesium is 0 to 140 ppm; all based on the weight of the second catalyst, wherein the polymerized polycarbonate has a branching level of less than or equal to 900 ppm.

[0011] The above described and other features are exemplified by the following detailed description.

DETAILED DESCRIPTION

[0012] Melt polycarbonate polymerization can be catalyzed by the combination of a first and a second catalyst, such as NaOH and TMAOH, respectively. Apart from the main polymerization reaction, there is a series of side reactions, also referred to as Fries

rearrangement, consisting of chain rearrangements products of the polymer backbone that lead to branching. The Applicants found that by using different combinations of first and second catalysts the branching level can be less than or equal to 5,000 parts per million by weight (ppm), specifically, less than 2,000 ppm, more specifically, less than or equal to 900 ppm, more specifically, less than or equal to 750 ppm, even more specifically, less than or equal to 410 ppm, still more specifically, less than or equal to 300 ppm based on the total weight of the polycarbonate. Specifically, they found that when the first catalyst comprises a first catalyst with a reduced activity and a lower selectivity for Fries rearrangement as compared to a first catalyst consisting of NaOH, KOH, CS₂CO₃, or a combination thereof, for example, KNaHP0₄, then the branching could be reduced.

[0013] As used herein reduced activity refers to, for example, the fact that under the same reaction conditions and the same molar equivalence of sodium in a first catalyst consisting of NaOH and sodium in a first catalyst consisting of KNaHP0₄, that the KNaHP0₄ catalyst will have a reduced activity in a melt polymerization as compared to the NaOH catalyst. As used herein reduced branching refers to the fact that the reduced activity catalyst as defined above, for example, consisting of KNaHP0₄, will result a polycarbonate with reduced branching as compared a first catalyst consisting of NaOH. [0014] Generally, such a reduced activity first catalyst is not used in the melt polymerization of polycarbonate as using a reduced activity first catalyst means that in some stages (especially in the second reactor), the amount of free (unreacted) monomer in the reaction mass is higher as compared to when pure NaOH is used. The increased

concentration of monomer, together with the high temperatures (for example, greater than or equal to 50°C) and low pressures (for example, under vacuum) results in increased monomer losses through the overheads system, causing significant variations in the molar ratio of the reactants and can therefore have an effect on the end cap ratio of product resulting in inconsistent product.

[0015] Regarding the second catalyst, TMAOH is generally used as a second transesterification catalyst in melt polymerization of polycarbonate. It is noted that first and second as used herein do not denote an order of addition in a melt polymerization and instead are used to differentiate the two catalysts. This second catalyst of TMAOH is thermo- sensitive and is generally active for only an amount of time in a first polymerization unit due to rapid degradation at elevated temperatures, specifically, at temperatures of greater than or equal to 175°C. In order to alleviate the monomer loss through the overheads system, the Applicants further found that when the reduced activity first catalyst was used in combination with a high temperature second catalyst instead of the thermo- sensitive second catalyst, TMAOH, that such a catalyst would improve the extent of reaction in the initial stages of the polymerization reaction to ultimately increase the extent of reaction of the monomers. As used herein, the "high temperature second catalyst" refers to a second catalyst that has a degradation temperature greater than the degradation temperature of TMAOH. Using the high temperature second catalyst, it was found that, under the same reaction conditions, the high temperature second catalyst was active for an increased amount of time in a melt polymerization where the temperature progressively increases as compared to a melt polymerization using a second catalyst consisting only of TMAOH. For example, the high temperature second catalyst can be active in the melt polymerization of polycarbonate at a temperature of 150 to 260°C and a pressure of greater than or equal to 100 mbara for an increased time as compared to a second catalyst consisting of TMAOH at the same reaction conditions. The high temperature second catalyst can comprise tetraphenyl phosphonium acetate (TPPA), tetraphenyl phosphonium phenolate (TPPP), or a combination comprising one or both of the foregoing. [0016] It was also found that the presence of alkali metal salts that can be present in the second catalyst, for example, a high temperature second catalyst comprising one or both of TPPA and TPPP, can increase the level of branching in the polycarbonate. It was found that the alkali metal salt compound can have an effect on the Fries reaction in different amounts depending on the metal specie (M) (i.e., sodium, potassium, and cesium) and their associated counter ion(s) (i.e., chloride, bromide, and sulfate). Accordingly, the type of metal compound can be determined, and then the amount of the metal present can be adjusted. By using an first catalyst and a second catalyst with a reduced concentration of alkali metal salt compounds, the branching in the polycarbonate can be less than or equal to 900 ppm, specifically, less than or equal to 750 ppm, more specifically, less than or equal to 410 ppm, even more specifically, less than or equal to 300 ppm based on the total weight of the polycarbonate.

[0017] For example, the second catalyst can comprise one or more of: a) less than or equal to 2,000 ppm of sodium, specifically, less than or equal to 1,675 ppm of sodium, specifically, less than or equal to 500 ppm of sodium, more specifically, less than or equal to 100 ppm of sodium, even more specifically, less than or equal to 30 ppm of sodium; b) less than or equal to 500 ppm of cesium, specifically, less than or equal to 300 ppm of cesium, more specifically, less than or equal to 135 ppm of cesium; and c) less than or equal to 100 ppm of potassium, specifically, less than or equal to 45 ppm of potassium; based on the total weight of the second catalyst.

[0018] For example, the second catalyst can comprise an alkali metal compound, wherein if the compound comprises sodium sulfate, the amount of sodium can be less than or equal to 1,690 ppm, specifically, less than or equal to 1,670 ppm based on the total weight of the second catalyst; if the compound comprises cesium sulfate, the amount of cesium can be less than or equal to 275 ppm, specifically, less than or equal to 252 ppm based on the total weight of the second catalyst; if the compound comprises sodium hydroxide, the amount of sodium can be less than or equal to 35 ppm, specifically, less than or equal to 29 ppm based on the total weight of the second catalyst; if the compound comprises potassium hydroxide, the amount of potassium can be less than or equal to 50 ppm, specifically, less than or equal to 43 ppm based on the total weight of the second catalyst; if the compound comprises cesium hydroxide, the amount of cesium can be less than or equal to 140 ppm, specifically, less than or equal to 132 ppm based on the total weight of the second catalyst; or a combination comprising one or more of the foregoing. [0019] For example, the second catalyst can comprise an alkali metal compound, wherein the amount of sodium can be greater than or equal to 1 ppm, or greater than or equal to 30 ppm, or greater than or equal to 100 ppm; the amount of cesium can be greater than or equal to 10 ppm, or greater than or equal to 30 ppm, or greater than or equal to 50 ppm; the amount of potassium can be greater than 0 ppm, or greater than or equal to 5 ppm, or greater than or equal to 10 ppm; or a combination comprising one or more of the foregoing, wherein the metal amounts are based on the weight of the second catalyst.

[0020] "Polycarbonate" as used herein means a polymer having repeating structural carbonate units of formula (1)

o

R¹— o— c— o (1)

in which at least 60 percent of the total number of R¹ groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic. Each R¹ can be a C₆-3o aromatic group, that is, contains at least one aromatic moiety. R¹ can be derived from an aromatic dihydroxy compound of the formula HO-R^OH, in particular of formula (2)

HO-A -Y -A^OH (2)

wherein each of A 1 and A2 is a monocyclic divalent aromatic group and Y 1 is a single bond or a bridging group having one or more atoms that separate A 1 from A 2. One atom can separate

A 1 from A2. Specifically, each R 1 can be derived from a bis henol of formula (3)

wherein R^a and R^b are each independently a halogen, C_1-12 alkoxy, or C_1-12 alkyl; and p and q are each independently integers of 0 to 4. It will be understood that when p or q is less than 4, the valence of each carbon of the ring is filled by hydrogen. Also in formula (3), X^A is a bridging group connecting the two hydroxy-substituted aromatic groups, where the bridging group and the hydroxy substituent of each C₆ arylene group are disposed ortho, meta, or para (specifically para) to each other on the C₆ arylene group. The bridging group X^A can be a single bond, -0-, -S-, -S(O)-, -S(0)₂-, -C(O)-, or a CM_S organic group. The C_1-18 organic bridging group can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. The C_1-18 organic group can be disposed such that the C₆ arylene groups connected thereto are each connected to a common alkylidene carbon or to different carbons of the C_1-18 organic bridging group. Each p and q can be 1, and R^a and R^b can each be a C_1-3 alkyl group, specifically methyl, disposed meta to the hydroxy group on each arylene group.

[0021] X^A can be a substituted or unsubstituted C₃_i₈ cycloalkylidene, a Ci_₂5 alkylidene of formula -C(R^c)(R^d)- 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 of the formula -C(=R^e)- wherein R^e is a divalent C_1-12 hydrocarbon group. Groups of this type include methylene, cyclohexylmethylene, ethylidene, neopentylidene, and isopropylidene, as well as 2-[2.2.1]-bicycloheptylidene, cyclohexylidene, cyclopentylidene, cyclododecylidene, and adamantylidene.

[0022] X^A can be a CM_S alkylene, a C_3-18 cycloalkylene, a fused C_6-18 cycloalkylene, or a group of the formula -B 1 -G-B2 - wherein B 1 and B2 are the same or different Ci_₆ alkylene and G is a C₃_i₂ cycloalkylidene or a C₆-i6 arylene. For example, X^A can be a substituted C_3-18 cycloalkylidene of formula (4)

wherein R^r, R^p, R^q, and R^£ are each independently hydrogen, halogen, oxygen, or C_1-12 hydrocarbon groups; Q is a direct bond, a carbon, or a divalent oxygen, sulfur, or -N(Z)- where Z is hydrogen, halogen, hydroxy, C_1-12 alkyl, C_1-12 alkoxy, or C_1-12 acyl; r is 0 to 2, t is 1 or 2, q is 0 or 1, and k is 0 to 3, with the proviso that at least two of R^r, R^p, R^q, and R^£ taken together are a fused cycloaliphatic, aromatic, or heteroaromatic ring. It will be understood that where the fused ring is aromatic, the ring as shown in formula (4) will have an unsaturated carbon-carbon linkage where the ring is fused. When k is one and i is 0, the ring as shown in formula (4) contains 4 carbon atoms, when k is 2, the ring as shown in formula (4) contains 5 carbon atoms, and when k is 3, the ring contains 6 carbon atoms. Two adjacent groups (e.g., R^q and R^£ taken together) can form an aromatic group, and R^q and R^£ taken together can form one aromatic group and R^r and R^p taken together can form a second aromatic group. When R^q and R^£ taken together form an aromatic group, R^p can be a double- bonded oxygen atom, i.e., a ketone.

[0023] Bisphenols wherein X^A is a cycloalkylidene of formula (4) can be used in the manufacture of polycarbonates containing phthalimidine carbonate units of formula (la)

wherein R^a, R^b, p, and q are as in formula (3), R³ is each independently a C_1-6 alkyl, j is 0 to 4, and R₄ is hydrogen, C_1-6 alkyl, or a substituted or unsubstituted phenyl, for example a phenyl substituted with up to five Ci_₆ alkyls. For example, the phthalimidine carbonate units are of formula (lb)

wherein R⁵ is hydrogen, phenyl optionally substituted with up to five 5 Ci_₆ alkyls, or Ci_₄ alkyl. In formula (lb), R⁵ can be hydrogen, methyl, or phenyl, specifically phenyl.

Carbonate units (lb) wherein R⁵ is phenyl can be derived from 2-phenyl-3,3'-bis(4-hydroxy phenyl)phthalimidine (also known as 3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-l-one, or N-phenyl phenolphthalein bisphenol ("PPPBP")).

[0024] Other bisphenol carbonate repeating units of this type are the isatin carbonate units of formula (lc) and (Id)

wherein R^a and R^b are each independently C_1-12 alkyl, p and q are each independently 0 to 4, and R¹ is C_1-12 alkyl, phenyl, optionally substituted with 1 to 5 Ci_io alkyl, or benzyl optionally substituted with 1 to 5 Ci_io alkyl. Each R^a and R^b can be methyl, p and q can each independently be 0 or 1, and R¹ is Ci_₄ alkyl or phenyl.

[0025] Other examples of bisphenol carbonate units derived from bisphenols (3) wherein X^a is a substituted or unsubstituted C_3-18 cycloalkylidene (4) include the

cyclohexylidene-bridged, alkyl-substituted bisphenol of formula (le)

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. At least one of each of R^a and R^b can be disposed meta to the cyclohexylidene bridging group. Each R^a and R^b can independently be Ci_₄ alkyl, R^g is Ci_₄ alkyl, p and q are each 0 or 1, and t is 0 to 5. R^a, R^b, and R^g can each be methyl, p and q can each be 0 or 1, and t can be 0 or 3, specifically 0.

[0026] Examples of other bisphenol carbonate units derived from bisphenol (3) wherein X^a is a substituted or unsubstituted C₃_i8 cycloalkylidene include adamantyl units of formula (If) and fluorenyl units of formula (lg)

wherein R^a and R^b are each independently C_1-12 alkyl, and p and q are each independently 1 4. At least one of each of R^a and R^b can be disposed meta to the cycloalkylidene bridging group. R^a and R^b can each be independently C_1-3 alkyl, and p and q can be each 0 or 1 ;

specifically, R^a, R^b can each be methyl, p and q are each 0 or 1, and when p and q are 1, the methyl group can be disposed meta to the cycloalkylidene bridging group. Carbonates containing units (la) to (lg) are useful for making polycarbonates with high glass transition temperatures (Tg) and high heat distortion temperatures.

[0027] Other useful dihydroxy compounds of the formula HO-R^OH include aromatic dihydroxy compounds of formula (6) (6)

wherein each Rⁿ is independently a halogen atom, C MO hydrocarbyl group such as a Ci_io alkyl, a halogen-substituted Ci_io alkyl, a C₆-io aryl, or a halogen-substituted C₆-io aryl, and n is 0 to 4. The halogen is usually bromine.

[0028] 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)-l-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, l,l-bis(4-hydroxyphenyl)cyclododecane, trans-2,3-bis(4- hydroxyphenyl)-2-butene, 2,2-bis(4-hydroxyphenyl)adamantane, alpha, alpha' -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 -t-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, l,l-dichloro-2,2- bis(4-hydroxyphenyl)ethylene, l,l-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, l,6-bis(4-hydroxyphenyl)-l,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)fluorine, 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-dihydroxyphenoxathin, 2,7-dihydroxy-9, 10-dimethylphenazine, 3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, and 2,7-dihydroxycarbazole, resorcinol, substituted resorcinol compounds such as 5-methyl resorcinol, 5-ethyl resorcinol,

5- propyl resorcinol, 5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl resorcinol, 5-cumyl resorcinol, 2,4,5, 6-tetrafluoro resorcinol, 2,4,5, 6-tetrabromo resorcinol, or the like; catechol; hydroquinone; substituted hydroquinones such as 2-methyl hydroquinone, 2-ethyl hydroquinone, 2-propyl hydroquinone, 2-butyl hydroquinone, 2-t-butyl hydroquinone, 2- phenyl hydroquinone, 2-cumyl hydroquinone, 2,3,5,6-tetramethyl hydroquinone, 2,3,5,6- tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluoro hydroquinone, 2,3,5, 6-tetrabromo

hydroquinone, or the like, or combinations comprising at least one of the foregoing dihydroxy compounds.

[0029] Specific examples of bisphenol compounds of formula (3) include l,l-bis(4- hydroxyphenyl) methane, l,l-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, l,l-bis(4-hydroxyphenyl) propane, l,l-bis(4-hydroxyphenyl) n- butane, 2,2-bis(4-hydroxy-2-methylphenyl) propane, l,l-bis(4-hydroxy-t-butylphenyl) propane, 3,3-bis(4-hydroxyphenyl) phthalimidine, 2-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine (PPPBP), and l,l-bis(4-hydroxy-3-methylphenyl)cyclohexane (DMBPC). Combinations comprising at least one of the foregoing dihydroxy compounds can also be used. The polycarbonate can be a linear homopolymer derived from bisphenol A, in which each of A 1 and A2 is p-phenylene and Y 1 is isopropylidene in formula (3).

[0030] The polycarbonate herein is prepared via the melt polymerization of a bisphenol and a carbonate precursor (also referred to as a carbonate compound). Exemplary carbonate precursors include a carbonyl halide such as carbonyl bromide or carbonyl chloride (phosgene) a bishaloformate of a dihydroxy compound (e.g., the bischloroformate of bisphenol A, hydroquinone ethylene glycol, neopentyl glycol, or the like), and diaryl carbonates. Combinations comprising at least one of the foregoing types of carbonate precursors can also be used. The diaryl carbonate ester can be diphenyl carbonate, or an activated diphenyl carbonate having electron-withdrawing substituents on each aryl, such as bis(4-nitrophenyl)carbonate, bis(2-chlorophenyl)carbonate, bis(4-chlorophenyl)carbonate, bis(methyl salicyl)carbonate, bis(4-methylcarboxylphenyl) carbonate, bis(2-acetylphenyl) carboxylate, bis(4-acetylphenyl) carboxylate, or a combination comprising at least one of the foregoing.

[0031] In the melt polymerization process, the polycarbonate can be prepared by co- reacting, in a molten state, a dihydroxy reactant and a carbonate precursor in the presence of a transesterification catalyst. The reaction can be carried out in typical polymerization equipment, such as a continuously stirred reactor (CSTR), plug flow reactor, wire wetting fall polymerizers, free fall polymerizers, horizontal polymerizers, wiped film polymerizers, BANBURY mixers, single or twin screw extruders, or a combination comprising one or more of the foregoing. Volatile monohydric phenol is removed from the molten reactants by distillation and the polymer is isolated as a molten residue. Melt polymerization can be conducted as a batch process or as a continuous process. In either case, the melt

polymerization conditions used can comprise two or more distinct reaction stages. For example, the polymerization can comprise an oligomerization stage in which the starting dihydroxy aromatic compound and diaryl carbonate are converted into an oligomeric polycarbonate and a second reaction stage also referred to a polymerization stage wherein the oligomeric polycarbonate formed in the oligomerization stage is converted to high molecular weight polycarbonate. The oligomerization stage can comprise 1 or more, specifically, 2 or more, more specifically, 2 to 4 oligomerization units (for example 2 to 4 continuously stirred tanks). When 2 or more oligomerization units are present in series, one or both of an increase in temperature or a decrease in pressure can occur from one unit to the next. The

polymerization stage can comprise 1 or more, specifically, 2 or more, more specifically, 2 polymerization units (for example 2 horizontal or wire wetting fall polymerizers). The polymerization stage can comprise one or more polymerization units that can polymerize the polycarbonate to a molecular weight of, for example, 20,000 to 50,000 Daltons. After formation of a polycarbonate, the polycarbonate composition can then be optionally quenched and a devolatilized in a devolatization unit, where the molecular weight of the polycarbonate does not significantly increase (for example, the molecular weight does not increase by greater than 10 weight percent (wt%)) and a temperature, a pressure, and a residence time are used to reduce the concentration of low molecular weight components (such as those with a molecular weight of less than 1,000 Daltons). The oligomerization unit is herein defined as a oligomerization unit that results in polycarbonates oligomers with a number average molecular weight of less than or equal to 12,000 Daltons or 8,000 Daltons and a polymerization unit is herein defined as a polymerization unit that produces polycarbonate with a number average molecular weight of greater than 12,000 Daltons or 8,000 Daltons. It is noted that while less than or equal to 12,000 Daltons or 8,000 Daltons is used here to define a molecular weight achieved in the oligomerization stage, one skilled in the art readily understands that said molecular weight is used to define an oligomerization stage, where the oligomer molecular weight could be greater than 12,000 Daltons or 8,000 Daltons. A "staged" polymerization reaction condition can be used in continuous

polymerization systems, wherein the starting monomers are oligomerized in a first reaction vessel and the oligomeric polycarbonate formed therein is continuously transferred to one or more downstream reactors in which the oligomeric polycarbonate is converted to high molecular weight polycarbonate. Typically, in the oligomerization stage the oligomeric polycarbonate produced has a number average molecular weight of 1,000 to 7,500 Daltons. In one or more subsequent polymerization stages the number average molecular weight (Mn) of the polycarbonate can be increased to, for example, 8,000 and 25,000 Daltons (using polycarbonate standard), specifically, 13,000 to 18,000 Daltons.

[0032] Typically, solvents are not used in the process, and the reactants dihydroxy compound and the carbonate compound are in a molten state. The reaction temperature can be 100 to 350 degrees Celsius (°C), specifically, 180 to 310°C. The pressure can be at atmospheric pressure, supra- atmospheric pressure, or a range of pressures from atmospheric pressure to 150 torr, specifically atmospheric pressure to 15 torr in the initial stages of the reaction, and at a reduced pressure at later stages, for example, 0.2 to 15 torr or 2 to 150 torr. Likewise, the polymerization can occur in a series of polymerization vessels that can each individually have increasing temperature and/or vacuum. For example, an oligomerization stage can occur at a temperature of 100 to 280°C, specifically, 140 to 240°C and a polymerization stage can occur at a temperature of 240 to 350°C, specifically, 280 to 300°C or 240 to 270°C or 250 to 310°C, where the temperature in the polymerization stage is greater than the temperature in the oligomerization stage. The reaction time from the initial oligomerization unit to the final polymerization unit can be 0.1 to 15 hours. A final polymerization unit as used herein refers to a final polymerization unit in the melt polymerization where the last increase in molecular weight occurs. For example, the quenching agent can be added to the polycarbonate resin after a final polymerization (e.g., after a point where the Mw of the polycarbonate will increases by less than or equal a 10%), and optionally, before any melt filtering.

[0033] Likewise, an oligomerization can occur at a pressure of greater than or equal to 100 millibars absolute (mbara) or the oligomerization can comprise at least two

oligomerization units where a first oligomerization unit can have a pressure of greater than or equal to 100 mbara and a second oligomerization can have a pressure of 15 to 90 mbara, where the first oligomerization unit is upstream of the second oligomerization unit, where one or more oligomerization units can be located before, in between, or after said polymerization units.

[0034] The polymerization stage following the oligomerization stage can comprise polymerizing in one or two polymerization units. The first polymerization unit can be at a temperature of 240 to 350°C, specifically, 260 to 310°C and a pressure of 1 to 10 mbar. The second polymerization unit can be at a temperature of 240 to 350°C, specifically, 260 to 300°C and a pressure of less than or equal to 5 mbar. The polycarbonate can be devolatized after a final polymerization.

[0035] After a final polymerization vessel (also referred to as a final polymerization unit), the polymer can be introduced to a reactor, extruded, subjected to filtration in a melt filter, or a combination comprising one or more of the foregoing. It is noted that the melt filter can be located before or after the extruder. For example, the melt polymerization process for the manufacture of a polycarbonate composition can comprise: melt polymerizing a dihydroxy reactant and a carbonate compound to produce a molten reaction product; quenching the molten reaction product; filtering the molten reaction product in a melt filter upstream of any extruders; optionally, introducing an additive to form a mixture; and extruding the mixture to form the polycarbonate composition. Likewise, the melt polymerization process for the manufacture of a polycarbonate composition can comprise: melt polymerizing a dihydroxy reactant and a carbonate compound to produce a molten reaction product; introducing a quencher composition and optionally an additive for form a mixture; and extruding the mixture to form the polycarbonate composition after filtration.

[0036] The polymerization process can comprise a section of parallel polymerization, where parallel polymerization refers to the splitting of a polycarbonate stream into two or more streams that may or may not experience the same polymerization conditions thereafter (i.e. they can attain different molecular weights, have different additives added thereto, etc.). For example, polycarbonate can be prepared in a first portion of the polymerization process; a stream comprising polycarbonate can be split into two or more streams and directed to 2 or more parallel operating lines. For example, a process can comprise polymerizing

polycarbonate in a series of oligomerization polymerization units; a stream exiting the oligomerization stage can be split into two streams: A and B, where stream A is directed to polymerization unit A and stream B is directed to polymerization unit B. Likewise, a process can comprise polymerizing polycarbonate in a series of oligomerization units followed by polymerizing in a series of polymerization units; a stream exiting the polymerization stage can be split into two streams: A and B, where stream A is directed to extruder A and stream B is directed to extruder B. Likewise, a process can comprise polymerizing polycarbonate in a series of oligomerization units followed by polymerizing in a series of two polymerization units; a stream exiting the first polymerization unit can be split into two streams: A and B, where stream A is directed to second polymerization unit A and stream B is directed to second polymerization unit B. In any of the aforementioned scenarios, a quencher composition can be added to one or both of streams A and B, where the quencher

composition can be the same or different. One skilled in the art can readily envision other embodiments comprising more than 2 parallel streams and embodiments where the streams are split at different locations.

[0037] The catalyst can comprise a first catalyst, for example, a reduced activity first catalyst. The catalyst can comprise a second catalyst, for example, a high temperature second catalyst. The catalyst can comprise a second catalyst with a reduced metal salt concentration, for example, a high temperature second catalyst with a reduced metal salt concentration. The catalyst can be a combination comprising one or more of the foregoing.

[0038] The first catalyst comprises a source of alkali or alkaline earth ions. The first catalyst is therefore a transesterification catalyst that is typically more thermally stable than the second catalysts, and therefore can be used throughout transesterification, during oligomerization, after oligomerization, e.g., in the polymerization vessels, during

polymerization. The Applicants found that by using a reduced activity first catalyst that the extent of branching can be reduced. The reduced activity first catalyst comprises a reaction product of a first catalyst I and a second catalyst II. The first catalyst I comprises a source of alkali or alkaline earth ions, where the total amount of alkali ions and alkaline earth ions present in the first catalyst I is herein referred to as the "first element," where the first element is the total amount of lithium, sodium, potassium, cesium, rubidium, magnesium, calcium, and strontium present from the first catalyst I. Sources of these ions include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, barium hydroxide, strontium hydroxide, and potassium hydroxide, as well as alkaline earth hydroxides such as magnesium hydroxide and calcium hydroxide. Other possible sources of alkali and alkaline earth metal ions include the corresponding salts of carboxylic acids (such as sodium acetate, potassium acetate, lithium acetate, calcium acetate, barium acetate, magnesium acetate, and strontium acetate) and derivatives of ethylene diamine tetra acetic acid (EDTA) (such as EDTA tetra sodium salt, and EDTA magnesium disodium salt). The first catalyst I can comprise alkali or alkaline earth metal salts of carbonate, such as CS₂CO₃, sodium bicarbonate (NaHC0₃), sodium carbonate (Na₂C0₃), potassium bicarbonate, lithium bicarbonate, calcium

bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, potassium carbonate, lithium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, and the like. The first catalyst I can comprise lithium stearate, sodium stearate, strontium stearate, potassium stearate, lithium hydroxyborate, sodium

hydroxyborate, sodium phenoxyborate, sodium benzoate, potassium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium salts of bisphenol A, dipotassium salts of bisphenol A, and dilithium salts of bisphenol A, sodium salts of phenol, potassium salts of phenol, lithium salts of phenol, or a combination comprising one or more of the foregoing. The first catalyst I can comprise a combination comprising one or more of the foregoing first catalysts I. [0039] The first catalyst II comprises a non-volatile inorganic acid, where the term "non-volatile" as used herein means that the acid from which the catalyst is made has no appreciable vapor pressure under melt polymerization conditions. Examples of non- volatile acids include phosphorous acid, phosphoric acid, sulfuric acid, and metal "oxo acids" such as the oxo acids of germanium, antimony, niobium and the like. Salts of non-volatile acids include alkali metal salts of phosphites; alkaline earth metal salts of phosphites; alkali metal salts of phosphates; alkaline earth metal salts of phosphates, alkali metal salts of sulfates, alkaline earth metal salts of sulfates, alkali metal salts of metal oxo acids, and alkaline earth metal salts of metal oxo acids. Specific examples of salts of non-volatile acids include NaH₂P0₃, NaH₂P0₄, Na₂HP0₄, KH₂P0₄, CsH₂P0₄, Cs₂HP0₄, NaKHP0₄, NaCsHP0₄, KCsHP0₄, Na₂S0₄, NaHS0₄, NaSb0₃, LiSb0₃, KSb0₃, Mg(Sb0₃)₂, Na₂Ge0₃, K₂Ge0₃, Li₂Ge0₃, MgGe0₃, Mg₂Ge0₄, and combinations comprising one or more of the foregoing compounds. The first catalyst II comprises a second element, where the second element is equal to total amount of alkali ions, alkaline earth ions, and metal ions present from the first catalyst II, for example, sodium, potassium, cesium, lithium, antimony, magnesium, and germanium.

[0040] The reduced activity first catalyst can comprise KNaHP0₄ derived from a first catalyst I of NaOH and first catalyst II of KH₂P0₄. The reduced activity first catalyst can have a molar ratio of the first element to the second element (for example, of the Na from NaOH to K from KH₂P0₄) of 0.5 to 2, specifically, 0.7 to 1.5, specifically, 0.8 to 1.2.

[0041] The reduced activity first catalyst can be prepared by preparing two solutions, solution I and solution II, comprising first catalyst I and first catalyst II, respectively.

Solution I can be prepared by dissolving first catalyst I in water. Solution I can be prepared at an elevated temperature of greater than 30°C, specifically, greater than or equal to 40°C. After preparing solution I, solution I can be cooled to a temperature of 20 to 30°C, specifically, 20 to 25°C. Solution I can comprise 0.1 to 60 wt%, specifically, 1 to 50 wt%, more specifically, 1 to 40 wt% of first catalyst I based on the total weight of the solution. For example, solution I can be prepared by combining 1 liter of water and a 40 to 60 wt% solution comprising 50 to 3,000 grams, specifically, 800 to 950 grams of the first catalyst I.

[0042] Solution II can be prepared by dissolving a first catalyst II in water. Solution II can comprise 0.1 to 40 wt%, specifically, 1 to 30 wt%, more specifically, 1 to 20 wt% of first catalyst II based on the total weight of the solution II. The solution II can comprise, for example, 100 to 4,000 grams, specifically, 1,500 to 2,000 grams of the first catalyst II in 20 liters of water.

[0043] Solution I and solution II can be combined to form solution III comprising the reduced first catalyst. Solution III can optionally be titrated to confirm that the solution comprises 0 to 20,000, specifically, 100 to 10,000 ppm of free first catalyst II, for example, free KH₂P0₄, where free first catalyst II refers to the amount of first catalyst II that has not complexed with first catalyst I and that still remains in solution. Solution III can be added directly to a melt polymerization or can be diluted prior to addition. Solution III, for example, after dilution, can comprise 0.1 to 50 wt%, specifically, 0.5 to 30 wt% of reduced first catalyst based on the total weight of solution III. For example, 500 to 4,000 kg, specifically, 1,000 to 1,500 kg of water can be added to solution III prior to addition to the polymerization unit.

[0044] The feed rate of solution III can be 0.1 to 10, specifically, 1 to 5 kilograms per hour (kg/h) into the polymerization unit based on a total monomer feed (i.e. the reactant feed) of 10,000 to 20,000 kg/h, specifically, 12,000 to 15,000 kg/h into the polymerization unit and a total bisphenol A feed rate of 5,000 to 9,000 kg/h of dihydroxy monomer to the

polymerization unit. For example, the flow rate of solution III can be 0.1 to 10 kg/h, specifically, 1 to 5 kg/h, more specifically, 2 to 3 kg/h into the polymerization unit based on a total monomer feed of 14,200 kg/h, wherein 7,250 kg/h of the monomer feed is a dihydroxy monomer. Solution III can be added to a monomer stream to form a catalyst stream and adding the catalyst stream to a polymerization unit. Likewise, solution III can be added to a polymerization at any stage in the polymerization, for example, upstream of, and/or directly to, and/or after a monomer mixing unit; and/or upstream of, and/or directly to, and/or after a polymerization unit (for example, to a first stage oligomerization unit and/or after a final polymerization unit).

[0045] The second transesterification catalysts (also referred to a second catalysts) typically degrade at elevated temperatures and lose their activity. Second transesterification catalysts can therefore be used at low-temperature polymerization stages, for example, in the oligomerization stage. The second catalyst comprises a quaternary ammonium compound, a quaternary phosphonium compound, or a combination comprising at least one of the foregoing.

[0046] The Applicants found that a high temperature second catalyst, for example, a second catalyst comprising one or both of TPPA and TPPP can be used in the melt polymerization of polycarbonate in order to improve the extent of reaction in the initial stages of polymerization to ultimately reduce monomer loss through the overhead system, for example, when a reduced activity first catalyst is used or when the polymerization is free of a first catalyst (i.e. a first catalyst is not added). The high temperature second catalyst can comprise tetraphenyl phosphonium acetate, tetraphenyl phosphonium phenolate, or a combination comprising one or both of the foregoing. The high temperature second catalyst can comprise TPPP. The high temperature second catalyst can comprise TPPA.

[0047] The second catalyst can comprise a quaternary ammonium compound that can be a compound of the structure (R⁴)₄N⁺X^~, wherein each R⁴ is the same or different, and is a Ci-20 alkyl, a C₄-₂o cycloalkyl, or a C₄-₂o aryl; and X^" is an organic or inorganic anion, for example, a hydroxide, halide, carboxylate, sulfonate, sulfate, formate, carbonate, or bicarbonate. Examples of organic quaternary ammonium compounds include tetramethyl ammonium hydroxide, tetrabutyl ammonium hydroxide, tetramethyl ammonium acetate, tetramethyl ammonium formate, tetrabutyl ammonium acetate, and combinations comprising at least one of the foregoing. The high temperature second catalyst can be free of a quaternary ammonium compound, for example, the high temperature second catalyst can be free of TMAOH.

[0048] The second catalyst can comprise a quaternary phosphonium compound that can be a compound of the structure (R⁵)₄P⁺X^~, wherein each R⁵ is the same or different, and is a Ci_2o alkyl, a C₄_2o cycloalkyl, or a C₄_2o aryl; and X^" is an organic or inorganic anion, for example a hydroxide, phenoxide, halide, carboxylate such as acetate or formate, sulfonate, sulfate, formate, carbonate, or bicarbonate. Where X^" is a polyvalent anion such as carbonate or sulfate, it is understood that the positive and negative charges in the quaternary ammonium and phosphonium structures are properly balanced. For example, where R 20 to R 23 are each methyls and X^" is carbonate, it is understood that X -^" represents 2(C0₃ -^~2 ). Examples of organic quaternary phosphonium compounds include tetramethyl phosphonium hydroxide, tetramethyl phosphonium acetate, tetramethyl phosphonium formate, tetrabutyl phosphonium hydroxide, tetraphenyl phosphonium acetate, tetraphenyl phosphonium phenoxide (TPPP), tetraethyl phosphonium acetate, tetrapropyl phosphonium acetate, tetrabutyl phosphonium acetate, tetrapentyl phosphonium acetate, tetrahexyl phosphonium acetate, tetraheptyl phosphonium acetate, tetraoctyl phosphonium acetate, tetradecyl phosphonium acetate, tetradodecyl phosphonium acetate, tetratolyl phosphonium acetate, tetramethyl phosphonium benzoate, tetraethyl phosphonium benzoate, tetrapropyl phosphonium benzoate, tetraphenyl phosphonium benzoate, tetraethyl phosphonium formate, tetrapropyl phosphonium formate, tetraphenyl phosphonium formate, tetramethyl phosphonium propionate, tetraethyl phosphonium propionate, tetrapropyl phosphonium propionate, tetramethyl phosphonium butyrate, tetraethyl phosphonium butyrate, and tetrapropyl phosphonium butyrate, and combinations comprising at least one of the foregoing.

[0049] The second catalyst, for example, the high temperature second catalyst, can be added to the polymerization unit in a solution of water, for example, in a solution of 10 to 80 wt%, specifically, 30 to 50 wt%, for example, 40 wt% of high temperature second catalyst in water.

[0050] The amount of first catalyst and second catalyst used can be based upon the total number of moles of dihydroxy compound used in the polymerization reaction. When referring to the ratio of second catalyst to all dihydroxy compounds used in the

polymerization reaction, it is convenient to refer to moles of catalyst per mole of the dihydroxy compound, meaning the number of moles of catalyst divided by the sum of the moles of each individual dihydroxy compound present in the reaction mixture. The transesterification catalyst can be used in an amount sufficient to provide 1 x 10 -^"8 to 1 x 10 -^"5 , specifically, 1 x 10^"7 to 8 x 10^"6, more specifically, 3 x 10^"7 to 2 x 10^"6 moles of catalyst per mole of aromatic dihydroxy compound used.

[0051] The first catalyst, for example, a reduced activity first catalyst, can be used in an amount sufficient to provide 1 x 10 -^"2 to 1 x 10 -^"8 moles, specifically, 1 x 10 -^"4 to 1 x 10 -^"7 moles of metal per mole of the dihydroxy compound used, where the metal can be Na. The amount of second catalyst (e.g., TPPA and/or TPPP) can be 1 x 10 -^"2 to 1 x 10 -^"7 , specifically 1 x 1(T 3 to 1 x 10^" 7' moles per total mole of the dihydroxy compound in the reaction mixture, for example, 50 micromoles of the second catalyst per mole of dihydroxy monomer. The amount of second catalyst (e.g., TPPA and/or TPPP) can be 0.1 to 100 microequivalents (με ), specifically 5 με to 90 με , and more specifically, 20 με to 80 με (in other words, 2xl0^"5 to 8xl0^"5 motes) ρεΓ total mole of the dihydroxy compound in the reaction mixture, for example, 50 micromoles of the second catalyst per mole of dihydroxy monomer.

[0052] Quenching of the transesterification catalysts and any reactive catalyst residues with an acidic compound after polymerization is completed can also be useful in some melt polymerization processes. Removal of catalyst residues and/or quenching agent and other volatile residues from the melt polymerization reaction after polymerization can also be useful in some melt polymerization processes. [0053] The first catalyst can be added to a polymerization at any stage in the polymerization, for example, upstream of, and/or directly to, and/or after a monomer mixing unit; and/or upstream of, and/or directly to, and/or after a polymerization unit (for example, to a first stage polymerization unit and/or after the second reaction stage polymerization unit). The second catalyst can be added to the polymerization unit upstream of, and/or directly to, and/or after a monomer mixing unit; and/or upstream of, and/or directly to, and/or after a first stage polymerization unit.

[0054] The second catalyst can be added to a catalyst tank prior to melt polymerizing. From the catalyst tank, the second catalyst can be continuously directed from the catalyst tank to a monomer mixing unit. When the amount of second catalyst is reduced to an amount, for example, less than or equal to 15 wt%, then a fresh amount of second catalyst can be added to the catalyst tank. Likewise, the second catalyst can be added in a batch addition step.

[0055] One or more steps in the present process can be automated via preprogrammed steps, for example, a catalyst addition step, a quencher addition step, a directing step, and the like.

[0056] A quencher composition can be added at one or more locations in the present melt preparation of the polycarbonate to reduce the activity of the catalyst. The quencher composition comprises a quenching agent (also referred to herein as a quencher). For example, the quenching agent can comprise a sulfonic acid ester such as an alkyl sulfonic ester of the formula R₁SO₃R₂ wherein Ri is hydrogen, C₁-C₁₂ alkyl, C₆-Ci₈ aryl, or C₇-C₁9 alkylaryl, and R₂ is C₁-C₁₂ alkyl, C₆-Ci₈ aryl, or C₇-C₁9 alkylaryl. Examples of alkyl sulfonic esters include benzenesulfonate, p-toluenesulfonate, methylbenzene sulfonate, ethylbenzene sulfonate, n-butyl benzenesulfonate, octyl benzenesulfonate and phenyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, n-butyl p-toluene sulfonate, octyl p- toluenesulfonate and phenyl p- toluenesulfonate. The sulfonic acid ester can comprise alkyl tosylates such as n-butyl tosylate. The sulfonic acid ester can be present in the quencher composition in an amount of 0.1 to 10 volume percent (vol%), specifically, 0.1 to 5 vol%, more specifically, 0.5 to 2 vol% based on the total volume of the quencher composition.

[0057] The quenching agent can comprise boric acid esters (e.g., B(OCH₃)₃,

B(OCH₂CH₃)₃, and B(OC₆H6)₃), zinc borate, boron phosphate, aluminum stearate, aluminum silicate, zirconium carbonate, zirconium C₁-C₁₂ alkoxides, zirconium hydroxycarboxylates, gallium phosphide, gallium antimonide, germanium oxide, C₁-C₃₂ organogermanium compounds, C₄-C₃₂ tetraorganotin tin compound, C₆-C₃₂ hexaorganotin compound (e.g., [(C6H₆0)Sn(CH₂CH₂CH₂CH₃)₂]₂0), Sb₂0 , antimony oxide, Ci-C ₂ alkylantimony, bismuth oxide, C₁-C₁₂ alkylbismuth, zinc acetate, zinc stearate, Ci-C₃₂ alkoxytitanium, and titanium oxide, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, polyphosphoric acid, boric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, sulfurous acid, adipic acid, azelaic acid, dodecanoic acid, L-ascorbic acid, aspartic acid, benzoic acid, formic acid, acetic acid, citric acid, glutamic acid, salicylic acid, nicotinic acid, fumaric acid, maleic acid, oxalic acid, benzenesulfinic acid, C₁-C₁₂ dialkyl sulfates (e.g., dimethyl sulfate and dibutyl sulfate), sulfonic acid phosphonium salts of the formula (R^aS0₃ ^")(PR^b ₄)⁺ wherein R^a is hydrogen, C₁-C₁₂ alkyl, C₆-Ci₈ aryl, or C7-C₁9 alkylaryl, and each R^b is independently hydrogen, C₁-C₁₂ alkyl or C₆-Ci₈ aryl, sulfonic acid derivatives of the formula A¹-^¹- SC^X¹)™ wherein A¹ is a Ci-C₄o hydrocarbon group having a valence of m, Y¹ is a single bond or an oxygen atom, X¹ is a secondary or tertiary alkyl group of the formula - CR¹⁵R¹⁶R¹⁷, a metal cation of one equivalent, an ammonium cation (e.g., NR^b ₃ ⁺ wherein each R^b is independently hydrogen, C₁-C₁₂ alkyl or C₆-Ci₈ aryl), or a phosphonium (e.g., PR^b ₄ ⁺ wherein each R^b is independently hydrogen, C₁-C₁₂ alkyl or C₆-Ci₈ aryl) wherein R¹⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R¹⁶ is a hydrogen atom, a phenyl group or an alky group having 1 to 5 carbon atoms, and R 17 is the same as or different from R¹⁵ and has the same definition as R¹⁵, provided that two of R¹⁵, R¹⁶, and R¹⁷ cannot be hydrogen atoms, and m is an integer of 1 to 4, provided that when Y¹ is a single bond, all of X¹ in an amount of m cannot be metal cations of one equivalent, a compound of the formula

+ X 2 -A2 -Y1 -S0₃ wherein A 2" is a divalent hydrocarbon group, + X2 is a secondary, tertiary or quaternary ammonium cation or a secondary (e.g., , tertiary or quaternary phosphonium cation, and Y¹ is a single bond or an oxygen atom, a compound of the formula A³-(⁺X³)_n-(R- wherein A³ is a Ci-C₄o hydrocarbon group having a valence of n, ⁺X³ is a secondary, tertiary or quaternary ammonium cation (e.g., NR^b ₃ ⁺ wherein each R^b is independently hydrogen, C₁-C₁₂ alkyl or C₆-Ci₈ aryl), or a secondary, tertiary or quaternary phosphonium cation (e.g., PR^b ₄ ⁺ wherein each R^b is independently hydrogen, C₁-C₁₂ alkyl or C₆-Ci₈ aryl), R is a monovalent Ci-C₄o hydrocarbon group, n is an integer of 2 to 4, and Y¹ is a single bond or an oxygen atom, a compound of the formula A⁵-Ad¹-A⁴-(Ad²-A⁵)_t wherein A⁵ is a monovalent or divalent Ci-C₄o hydrocarbon group, A⁴ is a divalent Ci-C₄o

hydrocarbon group, each of Ad 1 and Ad 2 is independently an acid anhydride group selected from -SO₂-O-SO₂-, -SO₂-O-CO-, and -CO-O-SO₂-, and £ is 0 or 1, provided that when I is O, -(Ad²-A⁵)_t is a hydrogen atom or a bond between A⁴ and A⁵, in which A⁵ is a divalent hydrocarbon group or a single bond, aminosulfonic esters having the formula R_aR_bN-A- S0₃R_c, wherein R_a and R are each independently hydrogen, C₁-C₁₂ alkyl, C6-C₂₂ aryl, C7-C₁9 alkylaryl or R_a and R , either singly or in combination, form an aromatic or non-aromatic heterocyclic compound with N (e.g., pyrrolyl, pyridinyl, pyrimidyl, pyrazinyl, carbazolyl, quinolinyl, imidazoyl, piperazinyl, oxazolyl, thiazolyl, pyrazolyl, pyrrolinyl, indolyl, purinyl, pyrrolydinyl, or the like), R_c is hydrogen, and A is C₁-C₁₂ alkyl, C₆-Ci₈ aryl, or C₁₇-C₁₉ alkylaryl (e.g., compounds such as N-(2-hydroxyethyl) piperazine-N'-3-propanesulfonic acid, 1,4,-piperazinebis (ethanesulfonic acid), and 5-dimethylamino-l-napthalenesulfonic acid), ammonium sulfonic esters of the formula R_aR_bR_cN⁺— A— S0₃ ^", wherein R_a, R_b, are each independently hydrogen, C₁-C₁₂ alkyl, C₁-C₁₂ aryl, C₇-Ci₉ alkylaryl, or R_a and R_b, either singly or in combination, form an aromatic or non-aromatic heterocyclic compound with N (e.g., pyrrolyl, pyridinyl, pyrimidyl, pyrazinyl, carbazolyl, quinolinyl, imidazoyl, piperazinyl, oxazolyl, thiazolyl, pyrazolyl, pyrrolinyl, indolyl, purinyl, pyrrolydinyl, or the like), R_c is a hydrogen, and A is C₁-C₁₂ alkyl, C₆-Ci₈ aryl, or C₇-Ci₉ alkylaryl, sulfonated polystyrene, methyl acrylate-sulfonated styrene copolymer, and combinations comprising at least one of the foregoing.

[0058] The quencher addition step can comprise mixing the quencher composition with the polymerized polycarbonate for a period of time of greater than or equal to 5 seconds prior to the addition to the polycarbonate of any reactive additive, wherein the reactive additive has a reactive OH group or reactive ester group. As used herein, when referring to "reactive" or a "reactive group", e.g., having a reactive OH^" group or a reactive ester group, the reactivity is with respect to polycarbonate.

[0059] An additive can further be added at one or more locations in the present melt preparation of the polycarbonate. For example, the additive can be added upstream of a polymerization unit, directly into a polymerization unit (for example, at an inlet, in a side feeder, in an outlet, or a combination comprising one or more of the foregoing), downstream of a polymerization unit, in a reactor that is not polymerizing polycarbonate, upstream of an extruder, directly into an extruder (for example, at the throat of the extruder, in a side feeder, in an outlet, or a combination comprising one or more of the foregoing), downstream of an extruder, or a combination comprising one or more of the foregoing. The additive can be added as part of the quencher composition or can be added separately. The additive can be added in a molten state or can be added after an extruded polycarbonate is re-melted. The additive can be filtered prior to being added into the polymerization unit.

[0060] The additive can comprise, for example, an impact modifier, a flow modifier, a filler (e.g., a particulate polytetrafluoroethylene (PTFE), glass, carbon, a mineral, or metal), a reinforcing agent (e.g., glass fibers), an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet (UV) agent (such as a UV light stabilizer and a UV absorbing additive), a plasticizer, a lubricant, a release agent (such as a mold release agent (such as glycerol monostearate, pentaerythritol stearate, glycerol tristearate, stearyl stearate, and the like)), an antistatic agent, an antifog agent, an antimicrobial agent, a colorant (e.g., a dye or pigment), a surface effect additive, a radiation stabilizer, a flame retardant, an anti-drip agent (e.g., a PTFE-encapsulated styrene-acrylonitrile copolymer (TSAN)), or a combination comprising one or more of the foregoing. For example, a combination of a heat stabilizer, mold release agent, and ultraviolet light stabilizer can be used. In general, the additives are used in the amounts generally known to be effective. For example, the total amount of the additive composition (other than any impact modifier, filler, or reinforcing agent) can be 0.001 to 10.0 weight percent (wt%), or 0.01 to 5 wt%, each based on the total weight of the polymer in the polymerized composition. The present polymerization can occur in the presence of or in the absence of a branching agent or in other words, the present process can comprise or can be free of a branching agent addition step.

[0061] The polycarbonate can have a light transparency of greater than 90% as determined using 3.2 millimeter (mm) thick samples using ASTM D 1003-00, Procedure B using CIE standard illuminant C, with unidirectional viewing. Accordingly, when the quenched composition has such a light transparency, it is herein referred to as an "optical grade" composition.

[0062] The polycarbonate can have a melt flow of less than or equal to 50 cubic centimeters per 10 minutes (cc/10 min), specifically, 3 to 30 cc/10 min as determined at 300°C and a load of 1.2 kilograms according to ASTM D1238-04.

[0063] The polycarbonate can have a melt flow of 4 to 40 grams per 10 minutes (g/10 min), for example, 4.5 to 15 g/10 min or 15 to 35 g/10 min as determined by ASTM D1238- 04 at 300°C, 1.2 kg. The polycarbonate can have a melt flow of 5 to 15 g/10 min as determined by ASTM D1238-04 at 250°C, 1.5 kg.

[0064] The polycarbonate can be, for example, a bisphenol A polycarbonate with a weight average molecular weight of 20,000 to 40,000 Daltons (using polycarbonate standard), for example, 21,800 Daltons with a melt flow of 24 to 32 g/10 min (ASTM D1238- 04, 300°C, 2.16 kg).

[0065] The polycarbonate can have a branching level of less than or equal to 1,200 ppm, specifically, less than or equal to 900 ppm, more specifically, less than or equal to 750 ppm, even more specifically, less than or equal to 410 ppm based on the total weight of the polycarbonate.

[0066] The polycarbonate can have an end cap level of greater than or equal to 60%, specifically, greater than or equal to 70%, more specifically, greater than or equal to 80%, where the end cap level is determined by dividing the total number of end groups of non- hydroxyl groups by the total number of end groups (for example, those derived from DPC plus those comprising a -OH group) and multiplying by 100.

[0067] The following examples are provided to illustrate the present melt

polymerization process. The examples are merely illustrative and are not intended to limit devices made in accordance with the disclosure to the materials, conditions, or process parameters set forth therein.

Examples

[0068] Melt polymerizations were run in a continuous melt polycarbonate plant, where 58.7 kg/h BPA and 55.1 kg/h of DPC were fed into a continuously stirred formulation tank. The formulation tank was operated at atmospheric pressure and 170°C. 75 micromoles of TPPA per mol of BPA were added to the formulation tank. In the case of the operation with TBPA, its addition was done at a rate of 50 micromoles of TBPA per mol of BPA as final concentration in formulation tank.

[0069] The outlet stream of the formulation tank was then pumped to a continuously stirred first reactor, which operated at 257°C and 180 millibar (mbar) vacuum in order to remove the reaction side-product, phenol. The vapor phase containing phenol and unreacted monomers BPA and DPC were continuously distilled in a scrubber where reflux ratio was adjusted so that the column head temperature was 127°C to yield high purity phenol.

Unreacted BPA and DPC were fed back into the first reactor. In order to compensate for the DPC losses in the phenol overhead streams of the forthcoming reactors, an additional stream of DPC was added to the first reactor at 1.8 kg/h. An aqueous stream of first catalyst as defined in each of the examples was added in the first reactor at a flowrate in milliliters per minute (mL/min). [0070] The outlet stream of the first reactor was then pumped to a continuously stirred second reactor, which operated at 280°C and 37 mbar vacuum. Due to the higher viscosity of this stream, a gear pump was used to convey the stream to the polymerization section where two horizontal polymerizers in series were used to reach the final polymer viscosity. The first polymerizer operated at 300°C and 2.5 to 3.0 mbar vacuum. Phenol was removed and the continuous agitation was provided by a spectacle-type blade run at 20 revolutions per minute (rpm). The polymer stream was then pumped to the second polymerizer, which operated at 1.0-1.5 mbar and 302°C. The second polymerizer had a lattice-type agitator running at 8 rpm. The polymer was then fed from the second

polymerizer to a 6 barrel twin screw finishing extruder (length/diameter (L/D)= 21, D= 44 mm), where the barrel temperature was set at 300°C and a spin rate of 100 rpm.

Examples 1 - 4

[0071] The polycarbonates of Examples 1-4 were polymerized using a reduced activity KNaHP0₄ first catalyst of and a high temperature TPPA second catalyst with varying metal and counter ion levels. The varying levels of the metal and counter ion in the catalysts and the resulting branching level were determined and are shown in Table 1. BDL stands for below detectable level.

[0072] Comparing Example 1 with Examples 2 and 3, Table 3 shows that the molecular weight is similar, but the branching level in Examples 2 and 3 is increased by about 300 ppm. In sum, Table 1 illustrates that a low sodium when present as hydroxide results in low branching level of less than 720 ppm.

[0073] Set forth below are some embodiments of the present disclosure.

[0074] Embodiment 1: A process of preparing a reduced activity first catalyst comprising: preparing an aqueous solution I comprising a first catalyst I; preparing an aqueous solution I comprising a first catalyst II, and optionally allowing the solution II to cool; combining the solution I and the solution II to form a solution III comprising the reduced activity first catalyst, where in the first catalyst I comprises an element I and the second catalyst II comprises an element II and wherein a molar ratio of Na to K is 0.5 to 2.

[0075] Embodiment 2: A process of preparing a reduced activity first catalyst comprising: preparing an aqueous solution I comprising a first catalyst I of NaOH; preparing an aqueous solution II comprising a first catalyst II of KH₂P0₄; and combining the solution I and the solution II to form a solution III comprising the reduced activity first catalyst comprising KNaHP0₄, wherein a molar ratio of Na to K is 0.5 to 2.

[0076] Embodiment 3: The process of any of the preceding Embodiments, wherein the molar ratio is 0.7 to 1.5 or 0.8 to 1.2.

[0077] Embodiment 4: The process of any of the preceding Embodiments, further comprising adding additional water to the solution III.

[0078] Embodiment 5: The process of Embodiment 4, wherein adding adds 500 to 4,000 kg of additional water.

[0079] Embodiment 6: The process of any of the preceding Embodiments, wherein the solution II comprises 100 to 4,000 grams of the first catalyst II in 20 liters of water.

[0080] Embodiment 7: The process of any of the preceding Embodiments, wherein the solution II comprises 1,500 to 2,000 grams of the first catalyst II in 20 liters of water.

[0081] Embodiment 8: The process of any of the preceding Embodiments, wherein the solution I comprises 50 to 3,000 grams of the first catalyst I in a 50 wt% solution in 1 liter of water.

[0082] Embodiment 9: The process of Embodiment 8, wherein the solution I comprises 800 to 950 grams of the first catalyst I in a 50 wt% solution in 1 liter of water.

[0083] Embodiment 10: The process of any of the preceding Embodiments, wherein the level of the free first catalyst II in solution III is 0 to 20,000 ppm.

[0084] Embodiment 11: The process of Embodiment 10, wherein the level is 100 to 10,000 ppm.

[0085] Embodiment 12: The process of any of the preceding Embodiments, further comprising titrating the solution III to measure a level of free KH₂P0₄.

[0086] Embodiment 13: A melt polymerization process comprising: melt polymerizing a dihydroxy compound and a carbonate compound in a polymerization unit to form polycarbonate, wherein the melt polymerizing comprises adding solution III of any of the preceding claims and a second catalyst to the melt polymerization process, wherein the polycarbonate has a branching level of less than or equal to 900 ppm.

[0087] Embodiment 14: The process of Embodiment 5, wherein the melt

polymerizing further comprises adding a second catalyst, wherein the second catalyst comprises a high temperature second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing.

[0088] Embodiment 15: A melt polymerization process comprising: melt polymerizing a dihydroxy compound and a carbonate compound in the presence of a catalyst composition to form a polycarbonate, wherein the catalyst composition comprises a second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing, wherein the polycarbonate has a branching level of less than or equal to 900 ppm.

[0089] Embodiment 16: A melt polymerization process comprising: melt

polymerizing a dihydroxy compound and a carbonate compound in a polymerization unit in the presence of a catalyst composition to form polymerized polycarbonate, wherein the catalyst composition comprises a second catalyst; wherein the second catalyst comprises a metal compound. The metal comprises at least one of sodium, potassium, and cesium. If the compound comprises sodium sulfate, the amount of sodium is 0 to 1,690 ppm. If the compound comprises cesium sulfate, the amount of cesium is 0 to 275 ppm. If the compound comprises sodium hydroxide, the amount of sodium is 0 to 35 ppm. If the compound comprises potassium hydroxide, the amount of potassium is 0 to 50 ppm. If the compound comprises cesium hydroxide, the amount of cesium is 0 to 140 ppm. All concentration values are based on the weight of the second catalyst. The polymerized polycarbonate has a branching level of less than or equal to 900 ppm.

[0090] Embodiment 17: The process of Embodiment 16, wherein the second catalyst comprises a high temperature second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing.

[0091] Embodiment 18: The process of any of Embodiments 15-17, wherein the polymerizing further comprises adding the solution III of any of Embodiments 1-12.

[0092] Embodiment 19: The process of any of Embodiments 13-18, wherein the branching level is less than or equal to 750 ppm.

[0093] Embodiment 20: The process of any of Embodiments 13-19, wherein an end cap level of the polycarbonate is greater than or equal to 60%. [0094] Embodiment 21: The process of any of Embodiments 13-20, wherein the polymerizing occurs in the presence of 0 wt% of a quaternary ammonium compound.

[0095] Embodiment 22: The process of any of Embodiments 14-21, wherein the second catalyst comprises tetra phenyl phosphonium acetate, or consists essentially of tetra phenyl phosphonium acetate, or consists of tetra phenyl phosphonium acetate.

[0096] Embodiment 23: The process of any of Embodiments 14-21, comprises tetra phenyl phosphonium phenoxide, or consists essentially of tetra phenyl phosphonium phenoxide, or consists of tetra phenyl phosphonium phenoxide.

[0097] Embodiment 24: The process of any of Embodiments 14-23, wherein the second catalyst is added in an amount of 1 x 10^"2 to 1 x 10^"5 or 1 x 10^"3 to 1 x 10^"4 moles per total mole of the dihydroxy compound.

[0098] Embodiment 25: The process of any of Embodiments 13-14 and 18-24, wherein the first catalyst is added in an amount of 1 x 10 -^"2 to 1 x 10 -^"8 or 1 x 10 -^"4 to 1 x 10 -^"7 moles per total mole of the dihydroxy compound.

[0099] Embodiment 26: The process of any of Embodiments 13-14 and 18-25, wherein adding of the solution III to the polymerization unit occurs at a rate of 0.1 to 10 kg/h.

[0100] Embodiment 27: The process of any of Embodiments 13-14 and 18-26, wherein adding comprises adding the solution III to a monomer stream to form a catalyst stream and adding the catalyst stream to a polymerization unit.

[0101] Embodiment 28: The process of any of Embodiments 13-27, wherein the polymerizing comprises oligomerizing an oligomer in an oligomerization stage comprising an oligomerization unit and polymerizing the oligomer in a polymerization stage comprising a polymerization unit and optionally further comprises adding the reactants to a monomer mixing unit prior to the polymerizing.

[0102] Embodiment 29: The process of Embodiment 28, further comprising adding the second catalyst upstream of, and/or directly to, and/or after the oligomerization unit.

[0103] Embodiment 30: The process of any of Embodiments 28-29, further comprising adding the first catalyst upstream of, and/or directly to, and/or after the oligomerization unit.

[0104] Embodiment 31: The process of any of Embodiments 28-30, further comprising adding the first catalyst upstream of, and/or directly to, and/or after the polymerization unit. [0105] Embodiment 32: The process of any of Embodiments 28-31, further comprising adding one or both of the second catalyst and the first catalyst upstream of, and/or directly to, and/or after the monomer mixing unit.

[0106] Embodiment 33: The process of any of Embodiments 28-32, wherein the oligomerization unit comprises 1 to 4 oligomerization units.

[0107] Embodiment 34: The process of Embodiment 33, wherein one or more of the oligomerization units is a continuously stirred tank.

[0108] Embodiment 35: The process of any of Embodiments 28-34, wherein the polymerization unit comprises 1 to 4 polymerization units.

[0109] Embodiment 36: The process of Embodiment 35, wherein one or more of the polymerization units comprises a horizontal polymerizer and/or a wire wetting fall polymerizer.

[0110] Embodiment 37: The process of any of Embodiments 13-36, wherein the polycarbonate is a bisphenol A polycarbonate.

[0111] Embodiment 38: The process of any of Embodiments 13-37, wherein the polymerizing further comprises adding a quencher composition, wherein the quencher composition comprises a quencher.

[0112] Embodiment 39: The process of Embodiment 38, wherein the quencher composition comprises 1 to 10 ppm of a sulfonic acid ester, based upon 100 parts of the polycarbonate.

[0113] Embodiment 40: The process of any of Embodiments 38-39, wherein the quencher composition comprises 1 to 10 ppm phosphorous acid, based upon 100 parts of the polycarbonate.

[0114] Embodiment 41: The process of any of Embodiments 38-40, wherein the quencher composition comprises 2 to 5 ppm sulfonic acid ester and 2 to 5 ppm phosphorous acid, based upon 100 parts of the polycarbonate.

[0115] Embodiment 42: The process of any of Embodiment 38-41, wherein quencher comprises n-butyl tosylate.

[0116] Embodiment 43: The process of any of Embodiments 38-42, wherein the quencher composition comprises 1 to 7 ppm quencher, based upon 100 parts of the polycarbonate. [0117] Embodiment 44: The process of any of Embodiments 38-43, wherein the quencher composition comprises 1.5 to 3 ppm quencher, based upon 100 parts of the polycarbonate.

[0118] Embodiment 45: The process of any of Embodiments 38-44, wherein the quencher comprises a difunctional compound having an acid or acid ester moiety and an amine moiety.

[0119] Embodiment 46: The process of any of Embodiments 38-45, wherein the quenching composition includes a compound of formula: R_a R R_c N⁺-A-S0₃ ^~

wherein R_a and Rb are each independently hydrogen, C₁-C₁₂ alkyl, C₁-C₁₂ aryl, or Ci-Cis alkylaryl; R_c is a hydrogen; R_a, R_b, singly or in combination form a heterocyclic ring structure with N; and A is C₁-C₁₂ alkyl, C₁-C₁₂ aryl, or Ci-Cig alkylaryl.

[0120] Embodiment 47: The process of any of Embodiments 38-46, wherein adding the quencher composition comprises spraying the quencher composition onto the

polycarbonate.

[0121] Embodiment 48: The process of any of Embodiments 38-47, further comprising mixing the polycarbonate with the quencher composition for a period of time of greater than or equal to 5 seconds prior to the addition to the polycarbonate of any additives having a reactive OH group or a reactive ester group and optionally adding one or both of a reactive additive to the polycarbonate and an unreactive additive to the polycarbonate, wherein the unreactive additive is free of a reactive OH group or reactive ester group.

[0122] Embodiment 49: The process of any of Embodiments 38-48, wherein the quencher composition comprises an unreactive additive.

[0123] Embodiment 50: The process of any of Embodiments 38-49, wherein the quencher composition comprises 0.1 to 100 wt% or 10 to 99 wt% quencher.

[0124] Embodiment 51: The process of any of Embodiments 38-50, wherein the quencher composition is a liquid quencher composition.

[0125] Embodiment 52: The process of any of Embodiments 38-51, wherein the quencher composition comprises a heat stabilizer.

[0126] Embodiment 53: The process of any of Embodiments 38-52, further comprising introducing an additive after adding of the quencher composition, and wherein the additive optionally comprises a release agent and a UV agent. [0127] Embodiment 54: The process of any of Embodiments 38-53, wherein adding a quencher composition comprises spraying the quencher composition onto the

polycarbonate.

[0128] Embodiment 55: The process of any of Embodiments 38-54, further comprising adding the quencher to a quencher vessel to form a quencher composition prior to adding the quencher composition.

[0129] Embodiment 56: The process of any of Embodiments 38-55, further comprising filtering the quencher composition and/or an additive prior to adding.

[0130] Embodiment 57: The process of any of Embodiments 38-56, wherein adding the quencher composition occurs at a pressure of greater than or equal to 2 bars or greater than or equal to 3 bars or 3 to 100 bars.

[0131] Embodiment 58: further comprising directing the polycarbonate to an extruder, wherein a solid quencher is added to the extruder.

[0132] Embodiment 59: The process of any of Embodiments 13-58, further comprising adding an additive optionally comprising antioxidant, a release agent, a UV agent, a flame retardant, or a combination comprising one or more of the foregoing.

[0133] Embodiment 60: The process of any of Embodiments 13-59, wherein the process is a batch process.

[0134] Embodiment 61: The process of any of Embodiments 13-60, wherein reactants are added to the polymerization unit at a rate of 10,000 to 20,000 kg/h.

[0135] Embodiment 62: The process of any of Embodiments 14-61, wherein the second catalyst is added to the polymerization unit as an aqueous solution, where a concentration of the aqueous solution is 30 to 50 wt% of the second catalyst based on the total weight of the solution.

[0136] Embodiment 63: The process of any of Embodiments 13-62, wherein a branching agent was not added before, during, or after the melt polymerizing.

[0137] Embodiment 64: The process of any of Embodiments 13-62, wherein a branching agent is added.

[0138] Embodiment 65: The process of any of Embodiments 63-64, wherein the branching agent comprises trimellitic acid, trimellitic anhydride, trimellitic trichloride, tris-p- hydroxyphenylethane, isatin-bis-phenol of formula (22)

tris-phenol TC (l,3,5-tris((p-hydroxyphenyl)isopropyl)benzene), tris-phenol PA (4(4(1,1- bis(p-hydroxyphenyl)-ethyl) alpha, alpha-dimethyl benzyl)phenol), 4-chloroformyl phthalic anhydride, trimesic acid, and benzophenone tetracarboxylic acid, or a combination comprising one or more of the foregoing.

[0139] Embodiment 66: The process of any of Embodiments 13-65, further comprising adding the second catalyst and optionally water to a second catalyst tank prior to melt polymerizing; and continuously directing the second catalyst from the second catalyst tank to a monomer mixing unit or adding the second catalyst in a batch addition step.

[0140] Embodiment 67: The process of Embodiment 66, further comprising adding a fresh amount of the second catalyst to the second catalyst tank when the amount of second catalyst is reduced to 15 wt%.

[0141] Embodiment 68: The process of any of Embodiments 13-67, wherein one or more steps is a programmed step in an automated process.

[0142] Embodiment 69: The process of any of Embodiments 13-68, wherein the melt polymerizing comprises melt polymerizing the polycarbonate in a series of first stage oligomerization units; splitting a stream exiting the first stage into a stream A and a stream B, directing stream A to a second stage polymerization unit A and directing stream B to a second stage polymerization unit B; or melt polymerizing the polycarbonate in a series of first stage oligomerization units, then polymerizing in a series of second stage polymerization units, splitting a stream exiting a final second stage polymerization unit into a stream A and a stream B, directing stream A to an extruder A and directing stream B to an extruder B; or melt polymerizing the polycarbonate in a series of first stage oligomerization units, then polymerizing in a series of two second stage polymerization units; splitting a stream exiting a first polymerization unit into a stream A and a stream B, directing stream A to a second polymerization unit A and directing stream B to a second polymerization unit B.

[0143] Embodiment 70: The process of any of Embodiments 13-69, wherein the melt polymerizing comprises oligomerizing at an oligomerization temperature of 100°C to 280°C, and polymerizing at a polymerization temperature of 250°C to 310°C, and wherein the oligomerization temperature is less than the polymerization temperature. [0144] Embodiment 71: The process of Embodiment 70, wherein the oligomerizing is at an oligomerization pressure of greater than 100 mbara.

[0145] Embodiment 72: The process of any of Embodiments 70-71, wherein the oligomerizing comprises a first oligomerization at a first oligomerization temperature of 150°C to 260°C at a first oligomerization pressure of greater than or equal to 100 mbara; and a subsequent oligomerization at a second oligomerization temperature of 230°C to 280°C, and a second oligomerization pressure of 15 to 90 mbara.

[0146] Embodiment 73: The process of any of Embodiments 70-72, wherein the polymerizing comprises a first polymerization at a first polymerization temperature of 260°C to 310°C at an polymerization pressure of 1 to 10 mbara; and a subsequent polymerization at a second polymerization temperature of 260°C to 300°C, and a second polymerization pressure of less than or equal to 5 mbara.

[0147] Embodiment 74: The process of Embodiment 73, wherein the first polymerization temperature is 260°C to 285°C; and the second polymerization temperature is 260°C to 285°C.

[0148] Embodiment 75: The process of any of Embodiments 73-74, wherein the first polymerization temperature is 270°C to 280°C; and the second polymerization temperature is 270°C to 280°C.

[0149] Embodiment 76: The process of any of Embodiments 73-75, wherein the polymerizing is in one or more wire wetting polymerizers and the polymerization temperature is 200°C to 300°C, and the polymerization pressure is less than or equal to 4 mbara.

[0150] Embodiment 77: The process of Embodiment 76, wherein the polymerization temperature is 250 to 280°C.

[0151] Embodiment 78: The process of any of Embodiments 13-77, further comprising devolatizing the polycarbonate optionally in an extruder and/or in a

devolatization unit.

[0152] Embodiment 79: The process of any of Embodiments 13-78, further comprising extruding the polycarbonate in an extruder, wherein the extruder is optionally a counter rotating twin screw extruder.

[0153] Embodiment 80: The process of any of Embodiments 14-79, further comprising introducing a first reactant to a mixer; melting the first reactant; then adding a second reactant and the second catalyst to the monomer mixing unit, wherein the first reactant is selected from diaryl carbonate and dihydroxy compound and the second reactant is the other of the diaryl carbonate and dihydroxy compound.

[0154] Embodiment 81: The process of any of Embodiments 1-80, wherein the first catalyst I comprises lithium hydroxide, sodium hydroxide, barium hydroxide, strontium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium acetate, potassium acetate, lithium acetate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, EDTA tetra sodium salt, EDTA magnesium disodium salt, CS₂CO₃, sodium bicarbonate (NaHC0₃), sodium carbonate (Na₂C0₃), potassium bicarbonate, lithium bicarbonate, calcium bicarbonate, barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, potassium carbonate, lithium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, lithium stearate, sodium stearate, strontium stearate, potassium stearate, lithium hydroxyborate, sodium hydroxyborate, sodium phenoxyborate, sodium benzoate, potassium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium salts of bisphenol A, dipotassium salts of bisphenol A, and dilithium salts of bisphenol A, sodium salts of phenol, potassium salts of phenol, lithium salts of phenol, or a combination comprising one or more of the foregoing.

[0155] Embodiment 82: The process of any of Embodiments 1-81, wherein the first catalyst II comprises NaH₂P0₃, NaH₂P0₄, Na₂HP0₄, KH₂P0₄, CsH₂P0₄, Cs₂ HP0₄,

NaKHP0₄, NaCsHP0₄, KCsHP0₄, Na₂S0₄, NaHS0₄, NaSb0₃, LiSb0₃, KSb0₃, Mg(Sb0₃)₂, Na₂Ge0₃, K₂Ge0₃, Li₂Ge0₃, MgGe0₃, Mg₂Ge0₄, or a combination comprising one or more of the foregoing.

[0156] Embodiment 83: The process of any of Embodiments 13-82, further comprising adding the second catalyst upstream of the first catalyst.

[0157] Embodiment 84: The process of any of Embodiments 14-83, wherein the second catalyst is active in the melt polymerization of polycarbonate at a temperature of 150 to 260°C and a pressure of greater than or equal to 100 mbara for an increased time as compared to a second catalyst consisting of TMAOH at the same reaction conditions.

[0158] Embodiment 85: A polycarbonate formed from the process of any of

Embodiments 13-84.

[0159] Embodiment 86: The polycarbonate of Embodiment 85, wherein the polycarbonate has an end cap level of greater than or equal to 60%. [0160] In general, the invention may alternately comprise, consist of, or consist essentially of, any appropriate components herein disclosed. The invention may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objectives of the present invention.

[0161] As used herein, when referring to a "reactive group", e.g., having a reactive OH^" group or a reactive ester group, the reactivity is with respect to polycarbonate.

[0162] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., ranges of "up to 25 wt%, or, more specifically, 5 to 20 wt%", is inclusive of the endpoints and all intermediate values of the ranges of "5 to 25 wt%," etc.). "Combination" is inclusive of blends, mixtures, alloys, reaction products, and the like. Furthermore, the terms "first," "second," and the like, herein do not denote any order, quantity, or importance, but rather are used to denote one element from another. The terms "a" and "an" and "the" herein 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. The suffix "(s)" as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the film(s) includes one or more films). Reference throughout the specification to "another embodiment," "an embodiment,"..., means that a particular element (e.g., feature, structure, and/or characteristic) 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. This application claims priority to European Patent Applications 13382432.6 filed October 28, 2013, 14382151.0 filed April 25, 2014, and 14382152.8 filed April 25, 2014, all of which are incorporated herein in their entirety.

[0163] While particular embodiments have been described, alternatives,

modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to Applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.

[0164] I/we claim:

Claims

1. A process of preparing a reduced activity first catalyst comprising:

preparing an aqueous solution I comprising NaOH;

preparing an aqueous solution II comprising KH₂P0₄; and

combining the solution I and the solution II to form a solution III comprising the reduced activity first catalyst comprising KNaHP0₄, wherein a molar ratio of Na to K is 0.5 to 2.

2. The process of Claim 1, further comprising adding additional water to the solution III.

3. The process of any of the preceding claims, wherein the molar ratio is 0.7 to

1.5.

4. The process of any of the preceding claims, further comprising titrating the solution III to measure a level of free KH₂P0₄.

5. A melt polymerization process comprising:

melt polymerizing a dihydroxy compound and a carbonate compound in a polymerization unit to form polycarbonate,

wherein the melt polymerizing comprises adding solution III of any of the preceding claims and a second catalyst to the melt polymerization process,

wherein the polycarbonate has a branching level of less than or equal to 900 ppm.

6. The process of Claim 5, wherein the melt polymerizing further comprises adding a second catalyst, wherein the second catalyst comprises a high temperature second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing.

7. A melt polymerization process comprising:

melt polymerizing a dihydroxy compound and a carbonate compound in the presence of a catalyst composition to form a polycarbonate, wherein the catalyst composition comprises a second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing,

8. A melt polymerization process comprising:

melt polymerizing a dihydroxy compound and a carbonate compound in a

polymerization unit in the presence of a catalyst composition to form polymerized

polycarbonate, wherein the catalyst composition comprises a second catalyst;

wherein the second catalyst comprises a metal compound, wherein the metal comprises at least one of sodium, potassium, and cesium;

wherein if the compound comprises sodium sulfate, the amount of sodium is 0 to 1,690 ppm; if the compound comprises cesium sulfate, the amount of cesium is 0 to 275 ppm; if the compound comprises sodium hydroxide, the amount of sodium is 0 to 35 ppm; if the compound comprises potassium hydroxide, the amount of potassium is 0 to 50 ppm; if the compound comprises cesium hydroxide, the amount of cesium is 0 to 140 ppm; all based on the weight of the second catalyst.

wherein the polymerized polycarbonate has a branching level of less than or equal to 900 ppm.

9. The process of Claim 8, wherein the second catalyst comprises a high temperature second catalyst comprising TPPA, TPPP, or a combination comprising one or both of the foregoing.

10. The process of any of Claims 7-9, wherein the polymerizing further comprises adding the solution III of any of Claims 1-4.

11. The process of any of Claims 5-10, wherein the branching level is less than or equal to 750 ppm.

12. The process of any of Claims 5-11, wherein an end cap level of the

polycarbonate is greater than or equal to 60%.

13. The process of any of Claims 5-12, wherein the polymerizing occurs in the presence of 0 wt% of a quaternary ammonium compound.

14. The process of any of Claims 6-13, wherein the second catalyst comprises tetra phenyl phosphonium acetate.

15. The process of any of Claims 6-13, wherein the second catalyst comprises tetra phenyl phosphonium phenoxide.

16. The process of any of Claims 6-15, wherein the second catalyst is added in an amount of 1 x 10 -^"2 to 1 x 10 -^"5 moles per total mole of the dihydroxy compound.

17. The process of any of Claims 5-6 and 10-16, wherein the first catalyst is added in an amount of 1 x 10^" to 1 x 10^" moles per total mole of the dihydroxy compound.