Halogen-free flame retardant polycarbonate compositions

Abstract

The present disclosure relates to a halogen-free flame retardant composition including (A) at least 65 wt.% of an aromatic polycarbonate, (B) at least 0.07 wt.% of a sulfonated phosphazene, and (C) optionally a siloxane. The halogen-free flame retardant composition may be used to form various articles with improved retardancy properties.

Description

24T&I0015-WO-ORDHALOGEN-FREE FLAME RETARDANT POLYCARBONATE COMPOSITIONSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.FIELD

[0002] The present disclosure is generally directed to a halogen-free flame retardant 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, limiting their use in applications where fire safety is a concern. To address this issue, flame retardant (FR) additives are commonly incorporated into PC formulations to improve fire resistance. Normally, increasing the amounts of flame retardant additives in the composition improves the flame retardancy properties of the polycarbonates. However, it impacts the optical (e.g., transparency) 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. Accordingly, there is a need to develop new thermoplastic polycarbonate compositions that contain PFAS / halogen-free flame retardant with no or minimal impact on transparency and mechanical performances.24T&I0015-WO-ORDSUMMARY

[0005] The present disclosure generally describes a halogen-free flame retardant composition including a polymeric resin and a sulfonated phosphazene. In one embodiment, the halogen-free flame retardant composition includes: at least 65 wt.% of an aromatic polycarbonate; and at least 0.07 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, 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&I0015-WO-ORD with at least one of Ri, R2, R3, R4 or R5 being -SO3M and where the wt.% is based on the total weight of the halogen-free flame retardant composition. In a further embodiment, the halogen- free flame retardant composition also includes a siloxane.

[0006] In another embodiment, the sulfonated phosphazene has the formulawhere each of Ai-Ae are selected fromwherein Ro is an alkyl group having from 1 to 10 carbon atoms, 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.24T&I0015-WO-ORD

[0007] In still another embodiment, there is provided a method of making the halogen-free flame retardant composition. The method generally includes combining the 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", "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.24T&I0015-WO-ORD

[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 less 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.24T&I0015-WO-ORD

[0016] The term “synergistic amount” of the sulfonated phosphazene and siloxane is used herein to indicate that the combined addition of the sulfonated phosphazene and siloxane 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 two 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 flame retardant composition includes:(A) at least 65 wt.% of an aromatic polycarbonate;(B) at least 0.07 wt.% of a sulfonated phosphazene having the 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&I0015-WO-ORDand at least one of Ri, R2, R3, R4 or R5 is -SO3M and optionally(C) a siloxane where the wt.% is based on the total weight of the halogen-free flame retardant composition.

[0019] According to another embodiment, the 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 beanzenedicarboxylic 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.

[0020] 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&I0015-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.

[0021] 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.

[0022] 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&I0015-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.

[0023] Aromatic polycarbonates 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 (BPA) 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 BPA, 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 end-capped and has at most 150 ppm, preferably at most 50 ppm, more preferably at most 10 ppm of phenol hydroxyl end-groups.

[0024] According to an embodiment, it is preferred that the aromatic polycarbonate includes bisphenol A polycarbonate (also referred to herein as bisphenol A polycarbonate homopolymer) or a mixture of bisphenol A polycarbonates. Preferably, the aromatic polycarbonate of the disclosure herein includes at least 75 wt.%, preferably at least 95 wt.% of bisphenol A polycarbonate based on the total weight of aromatic polycarbonate. In an embodiment, the aromatic polycarbonate in the composition essentially consists or consists of bisphenol A polycarbonate.

[0025] In an embodiment, the 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.24T&I0015-WO-ORD

[0026] In an embodiment, the aromatic polycarbonate is an interfacial polycarbonate. In another embodiment, the aromatic polycarbonate is a melt polycarbonate. In yet another embodiment, the polycarbonate is a mixture of from 20 wt.% to 80 wt. % or 40 wt.% to 60 wt.% of interfacial polycarbonate and from 80 wt.% to 20 wt. % or 60 wt.% to 40 wt.% of melt polycarbonate, based on the weight of the aromatic polycarbonate.

[0027] In another embodiment, the polycarbonate may be a mixture of two or more aromatic polycarbonates differing in melt flow rates. For example, the aromatic polycarbonate may be a mixture of two or more bisphenol A polycarbonate homopolymers with mutually different weight average molecular weight. 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 1.5 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.

[0028] In an embodiment, the halogen-free flame retardant composition includes 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.%, based on the total weight of the halogen-free flame retardant composition, of the aromatic polycarbonate. In another embodiment, the halogen-free flame retardant composition includes from 65 wt.% to 99.93 wt.%, or from 70 wt.% to 99 wt.%, or from 75 wt.% to 95 wt.% or from 80 wt.% to 90 wt.%, based on the total weight of the halogen-free flame retardant composition, of the aromatic polycarbonate.

[0029] According to an embodiment, M in the sulfonated phosphazene 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.

[0030] According to one embodiment, the halogen-free composition includes at least 0.07 wt.%, or at least 0.08 wt.%, or at least 0.09 wt.%, or at least 0.1 wt.%, or at least 0.2 wt.%, or at24T&I0015-WO-ORD least 0.3 wt.%, or at least 0.4 wt.%, or at least 0.5 wt.%, based on the total weight of the halogen- free flame retardant composition, of the sulfonated phosphazene. In another embodiment, the halogen-free flame retardant composition includes from 0.07 wt.% to 5.0 wt.%, or from 0.07 wt.% to 4.0 wt.%, or from 0.07 wt.% to 3.0 wt.%, or from 0.07 wt.% to 2.0 wt.%, or from 0.07 wt.% to 1.0 wt.%, based on the total weight of the halogen-free flame retardant composition, of the sulfonated phosphazene.

[0031] 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 phosphazenes above include 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.

[0032] In another embodiment, the halogen-free flame retardant composition includes the aromatic polycarbonate, sulfonated phosphazene of formula I 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.%. In other embodiments, the amount of sulfonated phosphazene may be an amount more than 0.1 wt.% such24T&I0015-WO-ORD 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 0.07 wt.% to 5.0 wt.%, or from 0.07 wt.% to 4.0 wt.%, or from 0.07 wt.% to 3.0 wt.%, or from 0.07 wt.% to 2.0 wt.% or from 0.07 wt.% to 1.0 wt.%, based on the total weight of the halogen-free flame retardant composition.

[0033] It has been surprisingly found when the combination of the sulfonated phosphazene and siloxane is added to the aromatic polycarbonate in a synergistic amount, the flame retardancy properties of the halogen-free flame retardant composition are enhanced as compared to the addition of either a sulfonated phosphazene described above or a siloxane are added alone to the aromatic polycarbonate. In an embodiment, the halogen-free flame retardant composition of the present disclosure includes:(A) at least 65 wt.% of an aromatic polycarbonate;(B) at least 0.07 wt.% of a sulfonated phosphazene having the formulawhere each of Ai-Ae are selected fromwherein Ro is an alkyl group having from 1 to 10 carbon atoms, 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;24T&I0015-WO-ORD and wherein at least one of Ai-Ae isand at least one of Ri, R2, R3, R4 or R5 is -SO3M and optionally(C) at least 0.01 wt.% of a siloxane, where the wt.% is based on the total weight of the halogen-free flame retardant.In another embodiment, the sulfonated phosphazene has the 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 isand at least one of Rl, R2, R3, R4 or R5 is -SO3M.24T&I0015-WO-ORD

[0034] 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, the siloxane is cyclotetrasiloxane of formula (Illb) and at least one of Re and R? is phenyl. Preferably both of Re and R? are phenyl.II IImethyl, phenyl , phenylmethyl, phenyl , phenyl(Illa)

[0035] 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.%, or from 0.01 wt.% to 15 wt.%, or 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.%, 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.%, or from 0.01 wt.% to 1.0 wt.%, based on the total weight of the halogen-free flame retardant composition.

[0036] 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).

[0037] In another embodiment, the halogen-free flame retardant composition of 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 or24T&I0015-WO-ORD more of flame retardant synergists, lubricants and mold release agents (for example pentaerythritol tetrastearate), nucleating agents, stabilizers, antistatics (for example conductive carbon blacks, chopped carbon fibers, carbon nanotubes and organic antistatics, such as polyalkylene ethers, alkyl sulfonates or polyamide-containing polymers), acids, fillers and reinforcing substances and dyestuffs and pigments. In a particular embodiment, the additives include an antioxidant, a mold release agent, or a UV stabilizer.

[0038] 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.

[0039] In an embodiment, the present disclosure provides a method of making the halogen- free flame retardant composition including: a) combining at least 65 wt.% of an aromatic polycarbonate with at least 0.07 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.

[0040] In another embodiment, at least 0.01 wt.% of a siloxane is combined with at least 65 wt.% of the aromatic polycarbonate and at least 0.07 wt.% of the sulfonated phosphazene, 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.

[0041] 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 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 fed24T&I0015-WO-ORD into the extruder. For example, flame retardant compositions can be prepared using a Krupp Werner & Pfleiderer ZSK2 co-rotating intermeshing 10-barrel twin screw extruder of 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.

[0042] 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 examples 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.

[0043] 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 that includes 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.

[0044] The present disclosure will now be further elucidated based on the following nonlimiting examples.Test Methods24T&I0015-WO-ORD

[0045] 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.24T&I0015-WO-ORD

[0046] 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 vessel 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 (IM 12) 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-cm X 4-cm X 3-mm) using micro injection moulder Xplore IM12. The transparency of these molded formulations was 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&I0015-WO-ORDTable 2: FR PC FormulationsTable 3: FR PC Formulations propertiesTable 3 clearly shows the combination of the sulfonated phosphazene of the present invention and siloxane, when added to the aromatic polycarbonate in a synergistic amount, enhanced the flame retardancy properties of the halogen-free flame retardant composition as compared to the addition of either a sulfonated phosphazene of formula I or a siloxane alone.

Claims

24T&I0015-WO-ORDC LA I M S1. A halogen-free flame retardant composition comprising:(A) at least 65 wt.% of an aromatic polycarbonate;(B) at least 0.07 wt.% of a sulfonated phosphazene of 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 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 isand at least one of Ri, R2, R3, R4 or R5 is -SO3M and optionally(C) a siloxane where 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 a compound having the formulas Ila - Ilh:24T&I0015-WO-ORD3. The halogen-free flame retardant composition of any one or more of claims 1-2, wherein each Ai-Ae is selected from a compound having the 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 aromatic polycarbonate comprises bisphenol A polycarbonate.

6. The halogen-free flame retardant composition of any one or more of claims 1-5, wherein the 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, 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 composition comprises:(A) 75 wt.% to 99.98 wt.% of the aromatic polycarbonate, preferably 90 wt.% to 99.98 wt.%; andB) 0.07 wt.% to 5 wt.% of the sulfonated phosphazene, preferably 0.07 wt.% to 3.0 wt.%, more preferably 0.07 wt.% to 2.0 wt.%, more preferably 0.07 wt.% to 1.0 wt.%.24T&I0015-WO-ORD8. 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 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).R6= methyl, phenyl R6= methyl, phenyl R7= methyl, phenyl R7= methyl, phenyl(Illa) (nib)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.

12. 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 a 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.4T&I0015-WO-ORD14. A method of making a halogen-free flame retardant composition of claim 1, comprising: a) combining at least at least 65 wt.% of the aromatic polycarbonate with at least 0.07 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 a siloxane with the aromatic polycarbonate and the sulfonated phosphazene to form the mixture.

Images