Halogen-free flame retardant and Anti-drip polycarbonate compositions

Abstract

The present disclosure relates to a halogen-free flame retardant composition including (A) at least 5 wt.% of a linear aromatic polycarbonate, (B) at least 0.01 wt.% of a sulfonated phosphazene, (C) at least 1.0 wt.% of a branched aromatic polycarbonate, and optionally, (D) a siloxane where the wt.% is based on the total weight of the halogen-free flame retardant composition. The halogen- free flame retardant composition may be used to form different articles with improved flame retardancy and anti-drip performance.

Description

24T&I0032-WO-ORDHALOGEN-FREE FLAME RETARDANT AND ANTI-DRIP POLYCARBONATECOMPOSITIONSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.FIELD

[0002] The present disclosure is generally directed to a halogen-free flame retardant and anti-drip composition including a polymeric resin, in particular a polycarbonate, and a sulfonated phosphazene.BACKGROUND

[0003] Polycarbonates (PC) are widely used in construction, automotive, electronic, electrical laminate, wire and cable, textile, and other applications due to their excellent mechanical properties and transparency. However, polycarbonates are inherently flammable and can drip hot molten material causing nearby materials to catch fire as well. To address these issues, flame retardant (FR) and anti-drip additives are commonly incorporated into PC formulations to improve fire and drip resistance. Generally, increasing the amounts of flame retardant and anti-drip additives in the composition improves the flame retardancy and drip resistance properties of the polycarbonates. However, it impacts the optical and mechanical properties of the polycarbonates.

[0004] Rimar salt (potassium perfluorobutane sulfonate, PFBS) is used widely in polycarbonate compositions to enhance flame retardancy as it exhibits good thermal stability and has minimal impact on the mechanical and optical properties. However, Rimar salt is a perfluoroalkyl sub stance (PFAS) and it is taken as a substance of very high concern (SVHC) under Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulations.

[0005] Accordingly, there is a need to develop new thermoplastic polycarbonate compositions that contain PFAS / halogen-free flame retardant and have drip resistance performance with no or minimal impact on transparency and mechanical performances.24T&I0032-WO-ORD 2SUMMARY

[0006] The present disclosure generally describes a halogen-free flame retardant composition including a polycarbonate resin and a sulfonated phosphazene. In one embodiment, the halogen-free flame retardant composition includes: at least 5 wt.% of a linear aromatic polycarbonate; at least 0.01 wt.% of a sulfonated phosphazene of formulawhere each of Ai-Ae are selected fromWherein, Ro is an alkyl group having from 1 to 10 carbon atoms, wherein, each of R1-R5 are selected from H, an alkyl group, an alkoxyl group having 1-10 carbon atoms, -NO2, -CN, -SO2R, -CO2R, -N(R)2, and -SO3M,R is an alkyl group,M is selected from Li, Na, K, Cs, Zn, Mg, Ca, Ce and Al; and wherein at least one of Ai-Ae is24T&I0032-WO-ORD with at least one of Ri, R2, R3, R4 or R5 being -SO3M; and at least 1 wt.% of a branched aromatic polycarbonate and where the wt.% is based on the total weight of the halogen-free flame retardant composition.

[0007] In yet another embodiment, there is provided a method of making the halogen-free flame retardant composition. The method generally includes combining the linear aromatic polycarbonate and branched aromatic polycarbonate with the sulfonated phosphazene to form a mixture and mixing the mixture to form the halogen-free flame retardant composition.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Not applicableDETAILED DESCRIPTION

[0009] If appearing herein, the term "comprising" and derivatives thereof are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is disclosed herein. In order, to avoid any doubt, all compositions claimed herein through use of the term "comprising" may include any additional additive, adjuvant, or compound, unless stated to the contrary. In contrast, the term, "consisting essentially of' if appearing herein, excludes from the scope of any succeeding recitation any other component, step or procedure, except those that are not essential to operability and the term "consisting of, if used, excludes any component, step or procedure not specifically delineated or listed. The terms "or" and “and / or”, unless stated otherwise, refer to the listed members individually as well as in any combination. For example, the expression A and / or B refers to A alone, B alone, or to both A and B.

[0010] The articles "a" and "an" are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical objects of the article. By way of example, "a polymer" means one polymer or more than one polymer. The phrases "in one embodiment", "according to one embodiment" and the like generally mean the particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the present disclosure and may be included in more than one embodiment of the present disclosure. Importantly, such phrases do not necessarily refer to the same embodiment. If the specification states a component or feature "may",24T&I0032-WO-ORD"can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[0011] The terms “preferred” and “preferably” refer to embodiments that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the present disclosure.

[0012] The term “about” as used herein can allow for a degree of variability in a value or range, for example, it may be within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range.

[0013] Values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but to also include all of the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range such as from 1 to 6, should be considered to have specifically disclosed sub-ranges, such as, from 1 to 3, from 2 to 4, from 3 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0014] The term “optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0015] The term “halogen-free flame retardant composition” refers to a composition in which a halogen-containing flame retardant is present in an amount that has no material effect on the overall composition. In some embodiments, “ halogen-free flame retardant composition” may refer to a composition in which the halogen-containing flame retardant is present in the composition in an amount of less than about 5 wt.%, or less than about 4 wt.%, or less than about 3 wt.% or less than about 2 wt.% or less than about 1 wt.%, or less than about 0.5 wt.%, or less24T&I0032-WO-ORD than about 0.1 wt.%, or less than about 0.05 wt.%, or even less than about 0.01 wt.% based on the total weight of the composition, or that no amount of halogen-containing flame retardant is present in the respective composition.

[0016] The term “synergistic amount” of the sulfonated phosphazene, siloxane and branched aromatic polycarbonate is used herein to indicate that the combined addition of the sulfonated phosphazene, siloxane and branched aromatic polycarbonate to the composition has a “synergistic effect” on certain properties of the resulting halogen-free flame-retardant composition or article prepared therefrom, i.e., the effect of the addition of the synergistic amount of the different components is greater than the effect of each component individually, and moreover, is greater than the sum of the individual component effects.

[0017] The present disclosure generally provides a halogen-free flame retardant composition including a polycarbonate resin and a sulfonated phosphazene.

[0018] According to one embodiment, the halogen-free flame retardant composition includes:(A) at least 5 wt.% of a linear aromatic polycarbonate;(B) at least 0.01 wt.% of a sulfonated phosphazene of formulawhere each of Ai-Ae are selected fromwherein Ro is an alkyl group having from 1 to 10 carbon atoms,24T&I0032-WO-ORD 6 wherein each of R1-R5 are selected from H, an alkyl group, an alkoxyl group having 1-10 carbon atoms, -NO2, -CN, -SO2R, -CO2R, -N(R)2, and -SO3M,R is an alkyl group,M is selected from Li, Na, K, Cs, Zn, Mg, Ca, Ce and Al; and wherein at least one of Ai-Ae iswith at least one of Ri, R2, R3, R4 or R5 being -SO3M;(C) at least 1.0 wt.% of a branched aromatic polycarbonate; and optionally,(D) a siloxane, where the wt.% is based on the total weight of the thermoplastic composition.

[0019] According to another embodiment, the sulfonated phosphazene has a formula,wherein, each of Ai-Ae are selected fromwherein, Ro is an alkyl group having from 1 to 10 carbon atoms, wherein, each of R1-R5 independently selected from H, an alkyl group, an alkoxyl group having 1- 10 carbon atoms, -NO2, -CN, -SO2R, -CO2R, -N(R)2, and -SO3M,R is an alkyl group,24T&I0032-WO-ORD 7M is selected from Li, Na, K, Cs, Zn, Mg, Ca, Ce and Al; and wherein at least one of Ai-Ae isand at least one of Ri, R2, R3, R4 or R5 being -SO3M.

[0020] In another embodiment, the linear aromatic polycarbonate useful in the present disclosure can be prepared from the reaction of diphenols with carbonoic acid halides, preferably phosgene, and / or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, by an interfacial process, optionally using chain terminators, for example monophenols. Preparation by a melt polymerization process by reaction of diphenols with, for example, diphenyl carbonate is also possible. Such processes are further described below.

[0021] The diphenols which may be used in preparing the aromatic polycarbonates may have the general formulawhere A represents a single bond, Ci-Cs-alkylene, C2-Cs-alkylidene, Cs-Ce-cycloalkylidene, -O-, -SO-, -CO-, -S-, -SO2-, Ce-Ci2-arylene, to which there can be fused further aromatic rings, or a radical of formulae24T&I0032-WO-ORDwhere B in each case represents Ci- to Cn-alkyl, preferably methyl, x in each case independently of the other represents 0, 1 or 2, p is 1 or 0, andR5and R6can be chosen individually for each X1and represent, independently of one another, hydrogen or Ci-Ce-alkyl, preferably hydrogen, methyl or ethyl,X1represents carbon and m represents an integer from 4 to 7, preferably 4 or 5, with the proviso that on at least one atom X1, R5and R6are simultaneously alkyl.

[0022] Examples of diphenols include, but are not limited to, hydroquinone, resorcinol, dihydroxy diphenols, bis-(hydroxyphenyl)-Ci-Cs-alkanes, bis-(hydroxyphenyl)-Cs-C6- cycloalkanes, bis-(hydroxyphenyl) ethers, bis-(hydroxyphenyl) sulfoxides, bis-(hydroxyphenyl) ketones, bis-(hydroxyphenyl)-sulfones and a,a-bis-(hydroxy-phenyl)-diisopropylbenzenes.Particularly preferred diphenols include 4,4'-dihydroxydiphenyl, bisphenol A, 2,4-bis(4- hydroxyphenyl)-2-methylbutane, 1 , 1 -bis-(4-hydroxyphenyl)-cyclohexane, 1 , 1 -bis-(4- hydroxyphenyl)-3,3,5-trimethylcyclohexane, 4,4'-dihydroxydiphenyl sulfide and 4,4 '-dihydroxy- diphenyl sulfone. In one preferred embodiment, the diphenol is bisphenol A.

[0023] Examples of chain terminators are, for example, phenol, p-chlorophenol, p-tert- butylphenol or 2,4,6-tribromophenol, and also long-chained alkylphenols, such as 4-[2-(2,4,4- trimethylpentyl)]-phenol, 4-(l,3-tetramethylbutyl)-phenol, monoalkylphenols or dialkylphenols having a total of from 8 to 20 carbon atoms in the alkyl substituents, such as 3,5-di-tert-24T&I0032-WO-ORD butylphenol, p-isooctylphenol, p-tert-octylphenol, p-dodecylphenol and 2-(3,5-dimethylheptyl)- phenol and 4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators that may be used is generally from 0.5 mol % to 10 mol %, based on the molar sum of the diphenols used in a particular case.

[0024] According to another embodiment, the branched aromatic polycarbonate useful in the present disclosure is an aromatic polycarbonate having branching. Some of such polycarbonates may be selected from branched polycarbonates disclosed in US20130136883A1, US20140179843A, US20130317146A1 and US5104964A, the contents of which are incorporated herein by reference. In a preferred embodiment, branched aromatic polycarbonates may be prepared from the reaction of branched diphenols with carbonoic acid halides, preferably phosgene, and / or with aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, by an interfacial process, optionally using chain terminators, for example monophenols. Preparation by a melt polymerization process by reaction of branched diphenols with, for example, diphenyl carbonate is also possible. Yet, in a preferred embodiment the branched polycarbonate is the polycarbonate disclosed in US20130317146A1. Branched polycarbonate can be prepared by adding a branching agent during polymerization. These branching agents include poly functional organic compounds containing at least three functional groups selected from hydroxyl, carboxyl, carboxylic anhydride, haloformyl, and mixtures of the foregoing functional groups. Specific examples include trimellitic acid, trimellitic anhydride, tris-phenol TC (l,3,5-tris((p- hydroxyphenyl)isopropyl)benzene), tris-phenol PA (4(4(1, 1 -bi s(p-hydroxyphenyl)-ethyl) alpha, alpha-dimethylbenzyl)phenol), 4-chloroformyl phthalic anhydride, trimesicacid, and benzophenone tetracarboxylic acid. In some embodiments, a particular type of branching agent is used to create branched polycarbonate materials. These branched polycarbonate materials have statistically more than two end groups. The branching agent is added in an amount (relative to the bisphenol monomer) that is sufficient to achieve the desired branching content, that is, more than two end groups. Examples of specific branching agents that are particularly effective in the compositions include trimellitic trichloride (TMTC), tris-p-hydroxyphenylethane (THPE), and isatin-bis-phenol, preferably tris-p-hydroxyphenylethane (THPE).24T&I0032-WO-ORD

[0025] Aromatic polycarbonates (linear and branched) are generally manufactured using two different technologies. In a first technology, known as the interfacial technology or interfacial process, phosgene is reacted with a diphenol, typically bisphenol A (BP A) in a liquid phase. Another well-known technology is the so-called melt technology, sometimes also referred to as melt transesterification or melt polycondensation technology. In the melt technology, or melt process, a diphenol, typically BP A, is reacted with a carbonate, typically diphenyl carbonate (DPC), in the melt phase. The aromatic polycarbonate obtained by the melt transesterification process is known to be structurally different from aromatic polycarbonate obtained by the interfacial process. In that respect, it is noted that, the so called “melt polycarbonate” typically has a minimum amount of Fries branching, which is generally absent in “interfacial polycarbonate”. Apart from that, melt polycarbonate typically has a higher number of phenolic hydroxy end groups while polycarbonate obtained by the interfacial process is typically endcapped and has at most 150 ppm, preferably at most 50 ppm, more preferably at most 10 ppm of phenol hydroxyl end-groups.

[0026] According to an embodiment, it is preferred that the linear aromatic polycarbonate includes linear bisphenol A polycarbonate or a mixture of linear bisphenol A polycarbonates. Preferably, the linear aromatic polycarbonate of the disclosure herein includes at least 75 wt.%, preferably at least 95 wt.% of linear bisphenol A polycarbonate based on the total weight of linear aromatic polycarbonate. In another embodiment, the linear aromatic polycarbonate in the composition essentially consists or consists of linear bisphenol A polycarbonate.

[0027] According to an embodiment, it is preferred that the branched aromatic polycarbonate includes branched bisphenol A polycarbonate or a mixture of branched bisphenol A polycarbonates. Preferably, the branched aromatic polycarbonate of the disclosure herein includes at least 75 wt.%, preferably at least 95 wt.% of branched bisphenol A polycarbonate based on the total weight of branched aromatic polycarbonate. In another embodiment, the branched aromatic polycarbonate in the composition essentially consists or consists of branched bisphenol A polycarbonate.24T&I0032-WO-ORD

[0028] In an embodiment, the linear aromatic polycarbonate has a weight average molecular weight (Mw) of 15,000 g / mol to 100,000 g / mol, preferably 15,000 g / mol to 80,000 g / mol, more preferably 15,000 g / mol to 50,000 g / mol, determined using gel permeation chromatography with polycarbonate standards.

[0029] In another embodiment, the branched aromatic polycarbonate has a weight average molecular weight of 15,000 g / mol to 100,000 g / mol, preferably 25,000 g / mol to 80,000 g / mol, more preferably 30,000 g / mol to 60,000 g / mol, determined using gel permeation chromatography with polycarbonate standards.

[0030] In an embodiment, the linear aromatic polycarbonate is an interfacial polycarbonate. In another embodiment, the linear aromatic polycarbonate is a melt polycarbonate. In yet another embodiment, the linear polycarbonate is a mixture of from 20 wt.% to 80 wt. % or 40 wt.% to 60 wt.% of interfacial linear polycarbonate and from 80 wt.% to 20 wt. % or 60 wt.% to 40 wt.% of melt linear aromatic polycarbonate, based on the weight of the linear aromatic polycarbonate.

[0031] In another embodiment, the branched aromatic polycarbonate is an interfacial polycarbonate. In an embodiment, the branched aromatic polycarbonate is a melt polycarbonate. In yet another embodiment, the branched polycarbonate is a mixture of from 20 wt.% to 80 wt.% or 40 wt.% to 60 wt.% of interfacial branched polycarbonate and from 80 wt.% to 20 wt.% or 60 wt.% to 40 wt.% of melt branched aromatic polycarbonate, based on the weight of the linear aromatic polycarbonate.

[0032] In an embodiment, the linear polycarbonate may be a mixture of two or more linear aromatic polycarbonates differing in melt flow rates. For example, the linear aromatic polycarbonate may be a mixture of two or more bisphenol A polycarbonate homopolymers with mutually different weight average molecular weights. The polycarbonate can have a melt flow rate, determined in accordance with ASTM D1238 (300°C, 1.2 kg) of 1 to 50 g / 10 min, preferably 2 to 40 g / 10 min, more preferably 2 to 20 g / 10 min. In an embodiment, the polycarbonate includes a polycarbonate copolymer comprising structural units of bisphenol A and structural units from another bisphenol.24T&I0032-WO-ORD

[0033] In another embodiment, the branched polycarbonate may be a mixture of two or more branched aromatic polycarbonates differing in melt flow rates. For example, the branched aromatic polycarbonate may be a mixture of two or more bisphenol A polycarbonate homopolymers with mutually different weight average molecular weight. The branched polycarbonate can have a melt flow rate, determined in accordance with ASTM DI 238 (300°C, 1.2 kg) of 1 to 50 g / 10 min, preferably 1.5 to 40 g / 10 min, more preferably 2 to 20 g / 10 min. In an embodiment, the branched polycarbonate includes a branched polycarbonate copolymer comprising structural units of bisphenol A and structural units from another bisphenol.

[0034] In an embodiment, the halogen-free flame retardant composition includes at least 65 wt.%, or at least 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 85 wt.%, or at least 90 wt.%, or at least 95 wt.%, or at least 99 wt.% of combined amount of linear and branched aromatic polycarbonate, based on the total weight of the halogen-free flame retardant composition. In another embodiment, the halogen-free flame retardant composition includes from 65 wt.% to 99.99 wt.%, or from 70 wt.% to 98 wt.%, or from 70 wt.% to 95 wt.% or from 70 wt.% to 94 wt.% of the combined amount of linear and branched aromatic polycarbonate, based on the total weight of the halogen-free flame retardant composition.

[0035] In another embodiment, the halogen-free flame retardant composition includes at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%, or at least 10 wt.%, or 15 wt.%, or at least 20 wt.%, or at least 25 wt.%, or at least 30 wt.%, or at least 35 wt.%, or at least 40 wt.%, or at least 45 wt.%, or 50 wt.%, or at least 55 wt.%, or at least 60 wt.%, or at least 65 wt.%, or at least 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 85 wt.% of the linear aromatic polycarbonate, based on the total weight of the halogen-free flame retardant composition. In a preferred embodiment, the halogen free flame retardant composition includes 5.0 wt.% to 70.0 wt.%, preferably 5.0 wt.% to 60.0 wt.%, more preferably 5.0 wt.% to 50.0 wt.%, more preferably 5.0 wt.% to 40.0 wt.% of the linear aromatic polycarbonate, based on the total weight of the halogen-free flame retardant composition.24T&I0032-WO-ORD

[0036] In a further embodiment, the halogen-free flame retardant composition includes at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, or at least 6 wt.%, or at least 7 wt.%, or at least 8 wt.%, or at least 9 wt.%, or at least 10 wt.%, or 15 wt.%, or at least 20 wt.%, or at least 25 wt.%, or at least 30 wt.%, or at least 35 wt.%, or at least 40 wt.%, or at least 45 wt.%, or 50 wt.%, or at least 55 wt.%, or at least 60 wt.%, or at least 65 wt.%, or at least 70 wt.%, or at least 75 wt.%, or at least 80 wt.%, or at least 85 wt.%, or at least 90 wt.%, or at least 95 wt.% of the branched aromatic polycarbonate, based on the total weight of the halogen- free flame retardant composition. In a preferred embodiment, the halogen free flame retardant composition includes 5.0 wt.% to 90.0 wt.%, preferably 5.0 wt.% to 80.0 wt.%, preferably 5.0 wt.% to 70.0 wt.%, preferably 5.0 wt.% to 65.0 wt.%, more preferably 5.0 wt.% to 60.0 wt.%, more preferably 5.0 wt.% to 50.0 wt.% more preferably 5.0 wt.% to 40.0 wt.% of the branched aromatic polycarbonate, based on the total weight of the halogen-free flame retardant composition.

[0037] According to another embodiment, M in the sulfonated phosphazene of formula I, is a metal. In some embodiments, a single metal or a combination of metals may be used. In one particular embodiment, M is selected from Li, Na, K, Zn, Mg, Ca, Ce and Al. In another particular embodiment, M is selected from Li, Na, and K. Preferably M is selected from Na and K. c

[0038] According to one embodiment, the halogen-free composition includes at least 0.01 wt.%, or at least 0.02 wt.%, or at least 0.03 wt.%, or at least 0.04 wt.%, or at least 0.05 wt.%, or at least 0.06 wt.%, or at least 0.07 wt.%, or at least 0.08 wt.%, or at least 0.09 wt.%. In other embodiments the halogen-free composition includes about 0.1 wt.% or at least 0.1 wt.%, or at least 0.2 wt.%, or at least 0.3 wt.%, or at least 0.4 wt.%, or at least 0.5 wt.%, or at least 0.6 wt.%, or at least 0.7 wt.%, or at least 0.8 wt.%, or at least 0.9 wt.%, or at least 1.0 wt.% of the sulfonated phosphazene, based on the total weight of the halogen-free flame retardant composition. In another embodiment, the halogen-free flame retardant composition includes from 0.01 wt.% to 5.0 wt.%, or from 0.01 wt.% to 4.0 wt.%, or from 0.01 wt.% to 3.0 wt.%, or from 0.01 wt.% to 2.0 wt.% and from 0.01 wt.% to 1.0 wt.% of the sulfonated phosphazene, based on the total weight of the halogen-free flame retardant composition,24T&I0032-WO-ORD

[0039] According to an embodiment, the Ai-Ae or A groups of the sulfonated phosphazenes described above are selected from compounds having formulas Ila - Ilh and a mixture thereof:The sulfonated phosphazene includes at least one or a combination of Ai-Ae or A groups selected from compounds having the formulas Ila - Ilh. In a particular embodiment, the Ai-Ae or A groups are selected from compounds having formulas Ila - lie. Preferably Ai-Ae or A is a compound having formula lib.

[0040] In another embodiment, the halogen-free flame retardant composition includes the linear aromatic polycarbonate, branched aromatic polycarbonate, sulfonated phosphazene and a siloxane. In this embodiment, the amount of sulfonated phosphazene in the halogen-free composition may be about 0.01 wt.%, or about 0.02 wt.%, or about 0.03 wt.%, or about 0.04 wt.%, or about 0.05 wt.%, or about 0.06 wt.%, or about 0.07 wt.%, or about 0.08 wt.%, 0.09 wt.%, or about 0.1 wt.% or an amount more than 0.1 wt.% such as at least 0.2 wt.%, at least 0.3 wt.%, at least 0.4 wt.%, or at least 0.5 wt.%„ based on the total weight of the halogen-free flame retardant composition. In a particular embodiment, the amount of sulfonated phosphazene in the halogen- free flame retardant composition is from 0.01 wt.% to 5.0 wt.%, or from 0.01 wt.% to 4.0 wt.%, or from 0.01 wt.% to 3.0 wt.%, or from 0.01 wt.% to 2.0 wt.% and from 0.01 wt.% to 1.0 wt.%, based on the total weight of the halogen-free flame retardant composition.24T&I0032-WO-ORD 15

[0041] It has been surprisingly found when the combination of the sulfonated phosphazene, siloxane and branched aromatic polycarbonate is added to the linear aromatic polycarbonate in a synergistic amount, the flame retardancy and anti-drip properties of the halogen-free flame retardant composition are enhanced as compared to the addition of either a sulfonated phosphazene or a siloxane alone or branched aromatic polycarbonate. In an embodiment, the halogen-free flame retardant composition of the present disclosure includes:(A) at least 5 wt.% of a linear aromatic polycarbonate;(B) at least 0.01 wt.% of a sulfonated phosphazene of formulawhere each of Ai-Ae are selected fromwherein, Ro is an alkyl group having from 1 to 10 carbon atoms, wherein, each of R1-R5 independently selected from H, an alkyl group, an alkoxyl group having 1- 10 carbon atoms, -NO2, -CN, -SO2R, -CO2R, -N(R)2, and -SO3M,R is an alkyl group,M is selected from Li, Na, K, Cs, Zn, Mg, Ca, Ce and Al; and wherein at least one of Ai-Ae isand at least one of Ri, R2, R3, R4 or R5 being -SO3M;24T&I0032-WO-ORD 16(C) at least 1.0 wt.% a branched aromatic polycarbonate, and(D)at least 0.01 wt.% a siloxane where the wt.% is based on the total weight of the halogen-free flame retardant composition.

[0042] In another embodiment, the sulfonated phosphazene has a formula,where each of Ai-Ae are selected fromwherein, Ro is an alkyl group having from 1 to 10 carbon atoms, wherein, each of R1-R5 independently selected from H, an alkyl group, an alkoxyl group having 1-10 carbon atoms, -NO2, -CN, -SO2R, -CO2R, -N(R)2, and -SO3M,R is an alkyl group,M is selected from Li, Na, K, Cs, Zn, Mg, Ca, Ce and Al; and wherein at least one of Ai-Ae isand at least one of Ri, R2, R3, R4 or R5 being -SO3M.

[0043] In an embodiment, the siloxane is selected from the group consisting of a cyclotrisiloxane, a cyclotetrasiloxane, a linear polysiloxane, a branched polysiloxane, a polyoctahedral silsesquioxanes, and a mixture thereof. In a particular embodiment, the siloxane is selected from a cyclotrisiloxane (Illa), a cyclotetrasiloxane (Illb), and a mixture thereof. Preferably, the siloxane is cyclotetrasiloxane (Illb). In a more preferred embodiment, the24T&I0032-WO-ORD siloxane is cyclotetrasiloxane of formula (Illb) and at least one of Re and R7 is phenyl. Preferably both of Re and R7 are phenyl.R6= methyl, phenylmethyl, phenyl R- = methyl, phenyl yl, phenyl(Illa)

[0044] In an embodiment, the amount of siloxane in the halogen-free flame retardant composition is from 0.01 wt.% to 30 wt.%, based on the total weight of the halogen-free flame retardant composition. In a particular embodiment, the amount of siloxane is from 0.01 wt.% to 20 wt.%, from 0.01 wt.% to 15 wt.%, from 0.01 wt.% to 10 wt.%, based on the total weight of the halogen-free flame retardant composition. Preferably, the amount of siloxane is from 0.01 wt.% to 5.0 wt.%, from 0.01 wt.% to 4.0 wt.%, from 0.01 wt.% to 3.0 wt.%, from 0.01 wt.% to 2.0 wt.% and from 0.01 wt.% to 1.0 wt.%, based on the total weight of the halogen-free flame retardant composition.

[0045] In a preferred embodiment, the halogen-free flame retardant composition of present disclosure is transparent. The term “transparent” means transmitting at least 85% of incident light in the visible spectrum (400-700 nm wavelength).

[0046] In another embodiment, the halogen-free flame retardant composition of the present disclosure contains 0 to 5 wt.% of other additives, based on the total weight of the halogen-free flame retardant composition. The additives include, but are not limited to anti-drip agents, one or more of flame retardant synergists, lubricants and mold release agents (for example pentaerythritol tetrastearate), nucleating agents, stabilizers, antistatics (for example conductive carbon blacks, carbon fibers, carbon nanotubes and organic antistatics, such as polyalkylene ethers, alkyl sulfonates or polyamide-containing polymers), acids, fillers and reinforcing substances and24T&I0032-WO-ORD dyestuffs and pigments. In a particular embodiment, the additives include an antioxidant, a mold release agent, or a UV stabilizer.

[0047] In an embodiment, the halogen-free flame retardant composition of the present disclosure, after curing, has a UL94 rating of V0 at a thickness of <3.2 mm, preferably <2.0 mm, more preferably <1.0 mm.

[0048] In an embodiment, the present disclosure provides a method of making the halogen- free flame retardant composition including: a) combining at least 5 wt.% of a linear aromatic polycarbonate with at least 1 wt.% of a branched aromatic polycarbonate and at least 0.01 wt.% of the sulfonated phosphazene described above to form a mixture; and b) mixing the mixture to form the halogen-free flame retardant composition, where the wt.% is based on the total weight of the halogen-free flame composition.

[0049] In another embodiment, at least 0.01 wt.% of a siloxane is combined with at least 5 wt.% of the linear aromatic polycarbonate, at least 1 wt.% of the branched aromatic polycarbonate and at least 0.01 wt.% of the sulfonated phosphazene of formula I, based on the total weight of the halogen-free flame retardant composition, to obtain a mixture and mixing the mixture to form the halogen-free flame retardant composition.

[0050] In an embodiment, the halogen-free flame retardant compositions of the present disclosure can be manufactured by various methods known in the art. For example, the linear and branched polycarbonate, sulfonated phosphazene, optional siloxane and other additives, if any, are first blended, in a high-speed mixer or by hand mixing to form a blend. The blend is then fed into the throat of a twin-screw extruder via a hopper. Alternatively, at least one of the additives or components of the halogen-free flame retardant composition can be incorporated into the composition by feeding it directly into the extruder at the throat and / or downstream through a side feeder, or by being compounded into a masterbatch with a desired aromatic polycarbonate and fed into the extruder. For example, halogen-free flame retardant compositions can be prepared using a Krupp Werner & Pfleiderer ZSK2 co-rotating intermeshing 10-barrel twin screw extruder of24T&I0032-WO-ORD diameter 25mm and L / D ratio 41. The temperature in the extruder may be from 180°C to 340°C along the screw length. The extrudate can be immediately cooled in a water bath and pelletized. The pellets so prepared can be 0.6 cm in length or less as desired. Such pellets can be used for subsequent molding, shaping, or forming.

[0051] Shaped, formed, or molded articles comprising the compositions are also provided. The halogen-free flame retardant compositions can be molded into articles by a variety of methods, such as injection molding, extrusion, and thermoforming. Some example of articles include articles used in interior or exterior automotive applications and also in electrical & electronic applications such as software products (mobiles, notebooks, monitors, tablets, data storage etc.) computer and (tele) communication applications and across other different segments and applications such as consumer products & appliances, automotive lighting, automotive under the hood, electric vehicle applications, electrical parts, electronic displays, energy storage and lighting applications.

[0052] Accordingly, the present disclosure relates to an article including the halogen-free flame retardant composition disclosed herein. In a particular embodiment, the present disclosure relates to manufacture of an article, preferably an automotive part or electrical or electronic part including the halogen-free flame retardant composition disclosed herein. Likewise, the present disclosure relates to a vehicle or an electrical or electronic equipment including the automotive part or the electrical or electronic part.

[0053] The present disclosure will now be further elucidated based on the following nonlimiting examples.Test Methods24T&I0032-WO-ORD

[0054] Sodium salt of sulfonated hexaphenoxycyclotriphosphazene (CPS-6Na)Synthesis of CPS-6Na: A solution of Sodium 4-hydroxybenzenesulfonate dihydrate (SBS, 23.4 g, 100 mmol), and 4 g of sodium hydroxide (100 mmol) was added dropwise into a solution of hexachlorophosphazene (HCCP) (5 g, 14.4 mmol) and then refluxed 2 days under N2 atmosphere.The reaction solution was neutralized by diluted HC1 to pH=7. A white solid was obtained after recrystallization. 1H NMR (DMSO, 5, ppm): 5=7.62 (12H, Ar-H), 6.73 (12H, Ar-H); 13C-NMR (DMSO, 5, ppm): 5= 150.23, 145.31, 128.02, 120.40; 31P-NMR (DMSO, 5, ppm): 5=8.87 (s, cyclotriphosphazene). FT-IR (KBr, cm-1): v 3456, 3072, 1595, 1495, 1220 1192, 1126, 1041, 1012, 966, 844.The same method was used for synthesizing CPS-6K and other salts.

[0055] FR PC formulations:An Xplore micro-compounder (MC15HT) was used to prepare FR PC formulations for UL94 testing. In a typical experiment, 10 grams total of powder ingredients were pre-mixed in a vessel24T&I0032-WO-ORD and subsequently added into the hopper. Processing conditions included a uniform barrel temperature of 280°C, screw speed of 250 RPM and mixing time of 1 minute. The melt was immediately transferred to an Xplore micro-injector (IM12) with a mold temperature of 80°C, injection pressure of 16 bar and hold time of 20 seconds to create standard UL 94 bars with dimensions 127 mm X 12.7 mm X 3.0 mm (length x width x thickness). UL 94 vertical burning tests were conducted in a standard UL cabinet manufactured by FTT. The flame was calibrated based on the UL 94 standard before testing. In a typical analysis, a plastic UL bar at fixed height was positioned above cotton and exposed to two 10-second applications of burning. After each 10 second flame application, observations of the flame out time and dripping behavior were recorded to determine UL classification. FR PC formulations were molded into a square color chip (4-cmX 4-cm X 3-mm) using micro injection moulder Xplore IM12. The transparency of these molded formulations were measured using an optical meter (model: RDM HTC-1003). The components of the compositions and their source are listed in Table 1. Table 1 : Components of the compositions and their source24T&I0032-WO-ORDTable 2: FR PC formulationsTable 3. FR PC formulation properties24T&I0032-WO-ORDTable 3 clearly shows that the combination of the sulfonated phosphazene, siloxane and branched aromatic polycarbonate of the present invention, when added to the linear aromatic polycarbonate in a synergistic amount, enhanced the flame retardancy and anti-drip properties of the halogen- free flame retardant composition as compared to the addition of either a sulfonated phosphazene or a siloxane or branched aromatic polycarbonate alone.

Claims

24T&I0032-WO-ORDC LA I M S1. A halogen-free flame retardant composition comprising:(A) at least 5 wt.% of a linear aromatic polycarbonate;(B) at least 0.01 wt.% of a sulfonated phosphazene of formulawhere each of Ai-Ae are selected fromwherein, Ro is an alkyl group having from 1 to 10 carbon atoms, wherein, each of R1-R5 independently selected from H, an alkyl group, an alkoxyl group having 1-10 carbon atoms, -NO2, -CN, -SO2R, -CO2R, -N(R)2, and -SO3M,R is an alkyl group,M is selected from Li, Na, K, Cs, Zn, Mg, Ca, Ce and Al; and wherein at least one of Ai-Ae isand at least one of Ri, R2, R3, R4 or R5 being -SO3M;(C) at least 1.0 wt.% of a branched aromatic polycarbonate; and(D) optionally, a siloxane, wherein the wt.% is based on the total weight of the halogen- free flame retardant composition.

2. The halogen-free flame retardant composition of claim 1, wherein each Ai-Ae is selected from compounds having formulas Ila - Ilh:24T&I0032-WO-ORD3. The halogen-free flame retardant composition of any one or more of claims 1-2, wherein each A is selected from formulas Ila - lie, preferably formula lib.

4. The halogen-free flame retardant composition of any one or more of claims 1-3, wherein M is selected from Li, Na, and K, preferably Na and K.

5. The halogen-free flame retardant composition of any one or more of claims 1-4, wherein the linear aromatic polycarbonate comprises bisphenol A polycarbonate and the branched aromatic polycarbonate comprises branched chain bisphenol A polycarbonate.

6. The halogen free flame retardant composition of any one or more of claims 1-5, wherein the linear aromatic polycarbonate has a weight average molecular weight of 15,000 g / mol to 100,000 g / mol, preferably 15,000 g / mol to 80,000 g / mol, more preferably 15,000 g / mol to 50,000 g / mol, and branched aromatic polycarbonate has a weight average molecular weight of 15,000 g / mol to 100,000 g / mol, preferably 25,000 g / mol to 80,000 g / mol, more preferably 30,000 g / mol to 60,000 g / mol, determined using gel permeation chromatography with polycarbonate standards.

7. The halogen-free flame retardant composition of any one or more of claims 1-6, wherein the thermoplastic composition comprises:24T&I0032-WO-ORDA) 1.0 wt.% to 85.0 wt.% of the linear aromatic polycarbonate, preferably 5.0 wt.% to 70.0 wt.%, preferably 5.0 wt.% to 60.0 wt.%, more preferably 5.0 wt.% to 50.0 wt.%, more preferably 5.0 wt.% to 40.0 wt.%;B) 0.01 wt.% to 5 wt.% of the sulfonated phosphazene, preferably 0.01 wt.% to 3.0 wt.%, more preferably 0.01 wt.% to 2.0 wt.%, more preferably 0.01 wt.% to 1.0 wt.%; andC) 15.0 wt.% to 94 wt.% of the branched aromatic polycarbonate, preferably 20 wt.% to 80.0 wt.%, preferably 30 wt.% to 75.0 wt.%, more preferably 40 wt.% to 75.0 wt.%, more preferably 60 wt.% to 75.0 wt.%.

8. The halogen-free flame retardant composition of any one or more of claims 1-7, wherein the composition further comprises at least 0.01 wt.% of a siloxane.

9. The halogen-free flame retardant composition of claim 8, wherein the siloxane is selected from the group consisting of a cyclotrisiloxane, a cyclotetrasiloxane, a linear polysiloxane, a branched polysiloxane, a polyoctahedral silsesquioxanes, and a mixture thereof.

10. The halogen-free flame retardant composition of any one or more of claims 8-9, wherein the siloxane is selected from a cyclotrisiloxane (Illa), a cyclotetrasiloxane (Illb), and a mixture thereof, preferably the cyclotetrasiloxane (Illb).methyl, phenyl R6= methyl, phenylmethyl, phenyl R7= methyl, phenyl(Illa) (Illb)11. The halogen-free flame retardant composition of any one or more of claims 8-10, wherein the siloxane is the cyclotetrasiloxane of formula (Illb) and at least one of Re and R? is phenyl, preferably both of Re and R? are phenyl.124T&I0032-WO-ORD12. The halogen-free flame retardant composition of any one or more of claims 1-11, wherein the composition further comprises one or more of an antioxidant, a mold release agent or an UV stabilizer.

13. The halogen-free flame retardant composition of any one or more of claims 1-12, wherein the composition, after curing, has a UL94 rating of VO at a thickness of <3.2 mm, preferably <2.0 mm, more preferably <1.0 mm.

14. A method of making a halogen-free flame retardant composition of claim 1 comprising: a) combining at least 5.0 wt.% of a linear aromatic polycarbonate and at least 1.0 wt.% of a branched aromatic polycarbonate, with at least 0.01 wt.% of the sulfonated phosphazene to form a mixture; and b) mixing the mixture to form the composition, wherein the wt.% is based on the total weight of the composition.

15. The method of claim 14 further comprising combining at least 0.01 wt.% of siloxane with the linear aromatic polycarbonate, the branched aromatic polycarbonate and the sulfonated phosphazene.

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