WO2019204713A1 - High comparative tracking index, halogen-free flame-retardant thermosetting compositions - Google Patents

Abstract

Halogen-free thermosetting resin compositions that include epoxy resin, optionally hydantoin based resin, oligomeric or polymeric phosphonates, and/or the like and exhibit improved comparative tracking index, improved glass transition temperature, improved heat resistance, improved flame retardancy are described herein. Some embodiments provide a halogen free thermosetting resin composition comprising an epoxy resin; and a phosphonate oligomer or phosphonate polymer. The compositions may be used to make a fiber reinforced laminate that has a comparative tracking index of at least 600 V.

Description

HIGH COMPARATIVE TRACKING INDEX, HALOGEN-FREE FLAME- RETARDANT THERMOSETTING COMPOSITIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims benefit of priority to the filing date of U.S. Provisional Patent Application No. 62/660,910 filed April 20, 2018, entitled,“HIGH COMPARATIVE

TRACKING INDEX, HALOGEN-FREE FLAME-RETARDANT THERMOSETTING

COMPOSITIONS,” and U.S. Provisional Patent Application No. 62/699,014 filed July 17, 2018, entitled,“HIGH COMPARATIVE TRACKING INDEX, HALOGEN-FREE FLAME RETARDANT THERMOSETTING COMPOSITIONS,” the contents of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

[0002] This invention relates generally to the field of flame-retardant compositions, and in particular to high comparative tracking index, halogen-free flame-retardant thermosetting compositions.

BACKGROUND

[0003] The Comparative Tracking Index (CTI) is a measure of the electrical breakdown (tracking) properties of an insulating material. Tracking refers to the formation of conductive paths across the surface of a material in the form of a carbonized track. The CTI measures the maximum voltage (V) at which a material withstands 50 drops of 0.1% ammonium chloride solution without tracking. The passing voltage of insulating materials is classified into 4 main groups: Materials Group 1 (CTI > 600), Materials Group II (> 400 CTI < 600),

Materials Group Ilia (> 175 CTI < 400), and Materials Group Illb (>100 CTI <175).

Thermosetting resins like bisphenol-A epoxy resins typically used as insulating materials in composites have CTI values around 300 V. Cycloaliphatic epoxy resins have the highest CTI values, whereas phenolic novolac epoxy resins have lower CTI values than bisphenol-A type epoxy resins. Epoxy -based laminates used in electrical applications like printed circuit boards for automotive applications and electronic components in high speed trains currently require CTI > 600 V.

[0004] In addition to meeting the CTI > 600 requirement, laminates must achieve a UL- 94 flammability standard V0 rating typically tested at 3 mm. For halogen-free epoxy thermosetting systems, the current state of art requires the addition of fillers like silica to meet both the high CTI > 600V and flame-retardant requirements. Fillers like silica are effective flame-retardants but also improve the tracking resistance of the system. Laminates containing the current commercial halogen-free flame retardants like 9,l0-dihydro-9-oxa-l0- phosphaphenanthrene-l 0-oxide (DOPO) cannot meet CTI > 600 without the use of fillers. In addition, phenolic novolacs typically used as hardeners for epoxy resins have low tracking resistance, resulting in failure to meet the 600 V CTI requirement.

[0005] For applications that do not use fillers, epoxy resins that have a high tracking resistance like dicyclopentadiene phenolic resins can be used, but they are more flammable and therefore require higher levels of flame retardants to achieve a V0 rating, which usually result in lowering of the CTI, making it difficult to meet the 600 V requirement.

[0006] Accordingly, there remains a critical need for flame-retardant thermosetting compositions with high comparative tracking index and without halogen.

SUMMARY

[0007] The present disclosure provides composition, method, and article of manufacture using, for example and without limitation, flame-retardant and halogen-free materials in compositions for varnish, prepreg, and laminate. It also pertains to compositions with high comparative tracking index.

[0008] Some embodiments provide a halogen free thermosetting resin composition comprising an epoxy resin; and a phosphonate oligomer or phosphonate polymer, wherein the composition is used to make a fiber reinforced laminate that has a comparative tracking index of at least 600 V. Some such embodiments further comprise a second resin selected from a hydantoin based resin or a dicyclopentadiene based resin.

[0009] Some embodiments further comprise a second co-hardener

[0010] Some embodiments further comprise a second flame retardant.

[0011] Some embodiments pertain to halogen-free thermosetting resin compositions containing phosphonate oligomers that can be used to produce laminates that meet both the CTI > 600V and flame-retardant UL-94 V0 requirements without the use of fillers. The phosphonate oligomers can act as both the flame retardant and the hardener, eliminating the need for phenolic curing agents that typically reducing the tracking resistance of the cured laminate. Lower amount of co-flame retardants can also be used to meet the UL-94 V0 specification without compromising on CTI.

[0012] In some embodiments, a halogen-free thermosetting resin composition with an epoxy resin, a hydantoin based resin, and a phosphonate oligomer wherein the composition has a comparative tracking index of at least 600 V is presented. In these embodiments, the composition can include a first epoxy resin and a second epoxy resin, a first phosphonate oligomer and a second phosphonate oligomer, or a combination thereof. In these

embodiments, the epoxy resin can be selected from the group consisting of bisphenol-A epoxy resin, bisphenol-F epoxy resin, bisphenol A novolac epoxy resin, biphenol novolac epoxy resin, and dicyclopentadiene novolac epoxy resin, or any combinations thereof. In these embodiments, the hydantoin based resin can be l,3-diglycidyl-5,5-dimethylhydantoin polymer. In these embodiments, the composition can further comprise a curing accelerator selected from the group consisting of imidazole compounds 2-ethyl-4-methyl imidazole, 2- phenyl imidazole, 2-methyl imidazole, phosphonium salts like tetraphenyl phosphonium phenolate and ethyltriphenyl phosphonium bromide, tetrabutyl ammonium, 4- dimethylaminopyridine, and boron trifluoride-ethylamine complex, or any combinations thereof.

[0013] In some embodiments, a method for preparing a prepreg comprising impregnating a reinforcing material with a halogen-free thermosetting resin composition comprising an epoxy resin, a hydantoin based resin, and a phosphonate oligomer wherein the composition has a comparative tracking index of at least 600 V is presented. In these embodiments, the prepreg can comprise drying and b-staging in an oven.

[0014] In some embodiments, a method for preparing a prepreg comprising drying and b- staging the prepreg in an oven at a temperature of at least 130 °C or at a temperature ranging from about 130 °C to about 190 °C is presented. In these embodiments, the prepreg can be dried and b-staged in an oven for less than about 5 min.

[0015] In some embodiments, a method for preparing a laminate comprising layering at least one prepreg is presented. In these embodiments, the prepreg can be prepared by impregnating a reinforcing material with a halogen-free thermosetting resin composition comprising an epoxy resin, a hydantoin based resin, and a phosphonate oligomer wherein the composition has a comparative tracking index of at least 600 V. In these embodiments, the prepreg can be prepared by drying and b-staging the prepreg in an oven at a temperature of at least 130 °C or at a temperature ranging from about 130 °C to about 190 °C. In these embodiments, the prepreg can be dried and b-staged in an oven for less than about 5 min.

[0016] In some embodiments, an article of manufacture comprising a laminate is presented. In these embodiments, the laminate can be prepared by layering at least one prepreg. I these embodiments, the prepreg can be prepared by impregnating a reinforcing material with a halogen-free thermosetting resin composition comprising an epoxy resin, a hydantoin based resin, and a phosphonate oligomer wherein the composition has a comparative tracking index of at least 600 V. In these embodiments, the prepreg can be prepared by drying and b-staging the prepreg in an oven at a temperature of at least 130 °C or at a temperature ranging from about 130 °C to about 190 °C. In these embodiments, the prepreg can be dried and b-staged in an oven for less than about 5 min. In these

embodiments, the article of manufacture can be a fiber reinforced composite, an electrical component, or a printed circuit board is presented.

DETAILED DESCRIPTION

[0017] The present disclosure is directed to composition, method, and article of manufacture using, for example and without limitation, flame-retardant and halogen-free materials in compositions for varnish, prepreg, and laminate. It also pertains to compositions with high comparative tracking index.

[0018] It will be appreciated that for clarity, the following discussion will describe various aspects of embodiments of the applicant’s teachings, while omitting certain specific details wherever convenient or appropriate to do so. For example, discussion of like or analogous features in alternative embodiments may be somewhat abbreviated. Well-known ideas or concepts may also for brevity not be discussed in any great detail. A person of ordinary skill in the art will recognize that some embodiments of the applicant’s teachings may not require certain of the specifically described details in every implementation, which are set forth herein only to provide a thorough understanding of the embodiments. Similarly, it will be apparent that the described embodiments may be susceptible to alteration or variation according to common general knowledge without departing from the scope of the disclosure. The following detailed description of embodiments is not to be regarded as limiting the scope of the applicant’s teachings in any manner.

[0019] The present application relates generally to composition, method, and article of manufacturing using halogen-free flame-retardant thermosetting compositions. For example, the compositions can have a high comparative tracking index. Various aspects of the invention are described in more detail below.

[0020] This disclosure is not limited to particular systems, devices, and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope.

[0021] So that the invention may more readily be understood, certain terms are first defined.

[0022] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments disclosed, the preferred methods, devices, and materials are now described. [0023] As used in this document, the singular forms“a,”“an,” and“the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Nothing in this disclosure is to be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term“comprising” means“including, but not limited to.”

[0024] “Halogen-free” refers to the International Electrochemical Commission’s (IEC) Definition of Halogen-Free, which is 900 ppm maximum chlorine, 900 ppm maximum bromine, and 1500 ppm maximum total halogens.

[0025] As used herein, 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 the event occurs and instances where it does not.

[0026] The term“substantially no” means that the subsequently described event may occur at most less than about 10 % of the time or the subsequently described component may be at most about less than 10 % of the total composition, in some embodiments, and in others, at most about less than 5 %, and in still others at most about less than 1 %.

[0027] The term“about” or“approximately” for any numerical values or range of values indicate a suitable dimensional tolerance that allows the composition, part, or collection of elements to function for its intended purpose as described herein. These terms indicate a ±10% variation about a central value.

[0028] The term“carbonate” as used herein is given its customary meaning, e.g., a salt of carbonic acid containing the divalent, negative radical CO or an uncharged ester of this acid. A“diaryl carbonate” is a carbonate with at least two aryl groups associated with the CO radical, the most predominant example of a diaryl carbonate is diphenyl carbonate; however, the definition of diaryl carbonate is not limited to this specific example.

[0029] The term“aromatic dihydroxide” is meant to encompass any aromatic compound with at least two associated hydroxyl substitutions. Examples of“aromatic hydroxides” include but are not limited to benzene diols such as hydroquinone and any bisphenol or bisphenol containing compounds.

[0030] The term“alkyl” or“alkyl group” refers to a branched or unbranched hydrocarbon or group of 1 to 20 carbon atoms, such as but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, decyl, tetradecyl, hexadecyl, eicosyl, tetracosyl and the like. “Cycloalkyl” or“cycloalkyl groups” are branched or unbranched hydrocarbons in which all or some of the carbons are arranged in a ring such as but not limited to cyclopentyl, cyclohexyl, methylcyclohexyl and the like. The term“lower alkyl” includes an alkyl group of 1 to 10 carbon atoms.

[0031] The term“aryl” or“aryl group” refers to monovalent aromatic hydrocarbon radicals or groups consisting of one or more fused rings in which at least one ring is aromatic in nature. Aryls may include but are not limited to phenyl, napthyl, biphenyl ring systems and the like. The aryl group may be unsubstituted or substituted with a variety of substituents including but not limited to alkyl, alkenyl, halide, benzylic, alkyl or aromatic ether, nitro, cyano and the like and combinations thereof.

[0032] “Substituent” refers to a molecular group that replaces a hydrogen in a compound and may include but are not limited to trifluoromethyl, nitro, cyano, C1-C20 alkyl, aromatic or aryl, C1-C20 alkyl ether, C1-C20 alkyl ester, benzyl halide, benzyl ether, aromatic or aryl ether, hydroxy, alkoxy, amino, alkylamino (-NHR’), dialkylamino (-NR’R”) or other groups which do not interfere with the formation of the diaryl alkylphosphonate.

[0033] The terms“flame retardant,”“flame resistant,”“fire resistant,” or“fire resistance,” as used herein, means that the composition exhibits a limiting oxygen index (LOI) of at least 27. “Flame retardant,”“flame resistant,”“fire resistant,” or“fire resistance,” may also be tested by measuring the after-burning time in accordance with the UL test (Subject 94). In this test, the tested materials are given classifications of UL-94 V-0, UL-94 V-l and UL-94 V-2 on the basis of the results obtained with the ten test specimens. Briefly, the criteria for each of these UL-94-V-classifications are as follows:

[0034] UL-94 V-0: the total flaming combustion for each specimen after removal of the ignition flame should not exceed 10 seconds and the total flaming combustion for 5 specimens should not exceed 50 seconds. None of the test specimens should release any drips which ignite absorbent cotton wool.

[0035] UL-94 V-l: the total flaming combustion for each specimen after removal of the ignition flame should not exceed 30 seconds and the total flaming combustion for 5 specimens should not exceed 250 seconds. None of the test specimens should release any drips which ignite absorbent cotton wool.

[0036] UL-94 V-2: the total flaming combustion for each specimen after removal of the ignition flame should not exceed 30 seconds and the total flaming combustion for 5 specimens should not exceed 250 seconds. Test specimens may release flaming particles, which ignite absorbent cotton wool. [0037] Fire resistance may also be tested by measuring after-burning time. These test methods provide a laboratory test procedure for measuring and comparing the surface flammability of materials when exposed to a prescribed level of radiant heat energy to measure the surface flammability of materials when exposed to fire. The test is conducted using small specimens that are representative, to the extent possible, of the material or assembly being evaluated. The rate at which flames travel along surfaces depends upon the physical and thermal properties of the material, product or assembly under test, the specimen mounting method and orientation, the type and level of fire or heat exposure, the availability of air, and properties of the surrounding enclosure. If different test conditions are substituted or the end-use conditions are changed, it may not always be possible by or from this test to predict changes in the fire-test-response characteristics measured. Therefore, the results are valid only for the fire test exposure conditions described in this procedure.

[0038] The state-of-the-art approach to rendering polymers flame retardant is to use additives such as brominated compounds or compounds containing aluminum and/or phosphorus. Use of the additives with polymer can have a deleterious effect on the processing characteristics and/or the mechanical performance of articles produced from them. In addition, some of these compounds are toxic, and can leach into the environment over time making their use less desirable. In some countries, certain brominated additives are being phased-out of use because of environmental concerns.

[0039] The compositions disclosed herein comprise an epoxy resin, a second resin (e.g. hydantoin), and a phosphonate oligomer or polymer where the CTI of the composition is at least 600V. The composition may optionally include a second hardener and/or second flame retardant.

[0040] In some of the embodiments, the epoxy resin is selected from the group consisting of bisphenol-A epoxy resin, bisphenol-F epoxy resin, bisphenol A novolac epoxy resin, biphenol novolac epoxy resin, and dicyclopentadiene novolac epoxy resin, or any

combinations thereof.

[0041] In some of the embodiments, the epoxy is selected from the group consisting of Bisphenol-A Epoxy resin Epon 828 (E828-EP), phenolic novolac Epon 154 (E154-EP), and 9,l0-dihydro-9-oxa-l0-phosphaphenanthrene-l0-oxide (DOPO) based epoxy (DOPO-EP) CW-500FF-03, or any combination thereof.

[0042] In some of the embodiments, the second resin is selected from hydantoin epoxy l,3-diglycidyl-5,5-dimethylhydantoin polymer (Hyd-EP) MHR-070 and dicyclopentadiene. Description of general phosphonate structures

[0043] Embodiments of the invention are not limited by the type of phosphonate component included and may include, for example, polyphosphonates, branched

polyphosphonates, or hyberbranched polyphosphonates, random or block

copolyphosphonates, co-obgo(phosphonate ester)s, or co-obgo(phosphonate carbonate)s, phosphonate oligomers, branched phosphonate oligomers, or hyperbranched phosphonates, and in certain embodiments, the phosphonate component may have the structures described and claimed in U.S. Patent Nos. US7,645,850, US7,8l6,486, US8,389,664, US8,563,638, US8,648,l63, US8,779,04l, US8,530,044, each of which is hereby incorporated by reference in its entirety.

[0044] Such phosphonate components may include repeating units derived from diaryl alkylphosphonates or diaryl arylphosphonates. For example, in some embodiments, such phosphonate components include structural units illustrated by Formula I:

[0045]

I

[0046] where Ar is an aromatic group and -O-Ar-O- may be derived from an aromatic dihydroxy compound or aromatic diol, R is a C 1-20 alkyl, C2-20 alkene, C2-20 alkyne, C5- 20 cycloalkyl, or C6-20 aryl, and nl is an integer from about 2 to about 200, from about 2 to about 100, from about 2 to about 75, from about 2 to about 50, from about 2 to about 20, from about 2 to about 10, or from about 2 to about 5, or any integer between these ranges.

[0047] The term“aromatic diol” is meant to encompass any aromatic or predominately aromatic compound with at least two associated hydroxyl substitutions of the formula (II):

[0048] wherein n2, p2, and q2 are each independently 0, 1, 2, 3, or 4; R^a is independently at each occurrence unsubstituted or substituted C1-10 hydrocarbyl; and X^a is a single bond, — O— ,— S— ,— S(O)— ,— S(0)2— ,— C(O)— , or a C1-18 hydrocarbylene, which can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise one or more heteroatoms selected from oxygen, nitrogen, sulfur, silicon, or phosphorus. As used herein, the term“hydrocarbyl”, whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue that contains only carbon and hydrogen unless it is specifically identified as“substituted hydrocarbyl”. The hydrocarbyl residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. The term“substituted” means including at least one substituent such as a hydroxyl, amino, thiol, carboxyl, carboxylate, amide, nitrile, sulfide, disulfide, nitro, C1-18 alkyl, C1-18 alkoxyl, C6-18 aryl, C6-18 aryloxyl, C7-18 alkylaryl, or C7-18 alkylaryloxyl.

[0049] Some illustrative examples of specific dihydroxy compounds include the following: bisphenol compounds such as 4, 4'-dihydroxy biphenyl, l,4-dihydroxynaphthalene, l,5-dihydroxynaphthalene, l,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7- dihydroxynaphthalene, bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)phenylmethane, bis(4-hydroxyphenyl)diphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)methane, bis(4- hydroxy-3,5-dichlorophenyl)methane, bis(4-hydroxy-3,5-dibromophenyl)methane, bis(4- hydroxy-3-methylphenyl)methane, bis(4-hydroxy-3-chlorophenyl)methane, bis(4- hy droxyphenyl)- 1 -naphthylmethane, 1 ,2-bis(4-hydroxyphenyl)ethane, 1 , 1 -bis(4- hydroxyphenyl)-l-phenylethane, 2,2-bis(4-hydroxyphenyl)propane (“bisphenol A” or “BPA”), 2-(4-hydroxyphenyl)-2-(3-hydroxyphenyl)propane, l,l-bis(4- hy droxyphenyl)cy clopentane, 1 , 1 -bis(4-hy droxyphenyl)cy clohexane, 1 , 1 -bis(4-hydroxy-3- methylphenyl)cyclohexane, l,l-bis-(4-hydroxyphenyl)-3, 3, 5-trimethylcy clohexane, 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-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy- 3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 4,4'- dihydroxybenzophenone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, bis(4-hydroxy-3,5- dichlorophenyl)ketone, 3,3-bis(4-hydroxyphenyl)-2-butanone, l,6-bis(4-hy droxyphenyl)- 1,6- hexanedione, ethylene glycol bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)ether, bis(4- hy droxyphenyl) sulfide, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfone, 9,9- bis(4-hydroxyphenyl)fluorene, 2,7-dihydroxypyrene, 6,6'-dihydroxy-3,3,3',3'- tetramethylspiro(bis)indane (“spirobiindane bisphenol”), phenolphthalein and

phenolphthalein derivatives, 3,3-bis(4-hydroxyphenyl)phthalimide, 2, 6-dihydroxy dibenzo-p- dioxin, 2,6-dihydroxythianthrene, 2,7-dihydroxyphenoxathin, 2,7-dihydroxy-9,l0- 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, 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, chlorohydroquinone, acetoxyhydroquinone, and nitrohydroquinone. Another dihydroxy compound includes 5,5-Bis(4-hydroxyphenyl)hydantoin.

[0050] In particular embodiments, the Ar may be derived from bisphenol A and R may be a methyl group providing polyphosphonates, phosphonate copolymers, random and block co- oligo(phosphonate carbonate)s and co-oligo(phosphonate ester)s, and oligomeric

phosphonates that may have structures such as, but not limited to, structures of Formulae III:

[0051]

wherein nl is an integral from about 2 to about 200, from about 2 to about 100, from about 2 to about 75, from about 2 to about 50, from about 2 to about 20, from about 2 to about 10, or from about 2 to about 5, or any integer between these ranges.

[0052] In some embodiments, a single aromatic diol may be used, and in other embodiments, various combinations of such aromatic diols may be incorporated into the polymer. The phosphorous content of phosphonate component may be controlled by the molecular weight (MW) of the aromatic diol used in the oligomeric phosphonates, polyphosphonates, or copolyphosphonates. A lower molecular weight aromatic diol may produce an oligomeric phosphonate, polyphosphonate, or copolyphosphonate with a higher phosphorus content. An aromatic diol, such as resorcinol, hydroquinone, or a combination thereof or similar low molecular weight aromatic diols may be used to make oligomeric phosphonates or polyphosphonates with high phosphorous content. The phosphorus content, expressed in terms of the weight percentage, of the phosphonate oligomers, phosphonates, or copolyphosphonates may be in the range from about 2 wt. % to about 18 wt. %, about 4 wt.

% to about 16 wt. %, about 6 wt. % to about 14 wt. %, about 8 wt. % to about 12 wt. %, or a value between any of these ranges. In some embodiments, phosphonate oligomers, polyphosphonates, or copolyphosphonates prepared from bisphenol A or hydroquinone may have phosphorus contents of 10.5 wt. % and 18 wt. %, respectively.

[0053] Description of polyphosphonates

[0054] In certain embodiments, the phosphonate component may be a polyphosphonate containing long chains of the structural unit of Formula I. In some embodiments, the polyphosphonates may have a weight average molecular weight (Mw) of about 10,000 g/mole to about 100,000 g/mole as determined by GPC, and in other embodiments, the polyphosphonates may have an Mw of from about 12,000 to about 80,000 g/mole as determined by GPC. The number average molecular weight (Mn) in such embodiments may be from about 5,000 g/mole to about 50,000 g/mole, or from about 8,000 g/mole to about 15,000 g/mole, and in certain embodiments the Mn may be greater than about 9,000 g/mole. The molecular weight distribution (i.e., Mw/Mn) of such polyphosphonates may be from about 2 to about 10 in some embodiments and from about 2 to about 5 in other embodiments.

[0055] In certain embodiments, the phosphonate component may be a polyphosphonate containing branched structures of the structural unit of Formula I. In some cases, a branching agent (i.e. tri or tetrahydroxy aromatic compound) may be added or it may be generated in- situ via a reaction of bisphenol A and an appropriate catalyst. In some embodiments, the branched polyphosphonates may have a molecular weight distribution (i.e., Mw/Mn) of from about 2 to about 10, from about 2 to about 5, or from about 2 to about 3.

[0056] Description of phosphonate copolymers

[0057] In some embodiments, the phosphonate component may be copolymers containing carbonate linkages [i.e., copoly (phosphonate carbonate)] or ester linkages [i.e.,

copoly (phosphonate esters)].

[0058] For example, copoly (phosphonate carbonate)s may include repeating units derived from at least 20 mole percent high purity diaryl alkylphosphonate or optionally substituted diaryl alkylphosphonate, one or more diaryl carbonate, and one or more aromatic dihydroxy compounds, wherein the mole percent of the high purity diaryl alkylphosphonate is based on the total amount of transesterification components, i.e., total diaryl alkylphosphonate and total diaryl carbonate. As indicated by the term“random” the monomers of the

copoly (phosphonate carbonate)s of various embodiments may be incorporated into polymer chain randomly. Therefore, the polymer chain may include alternating phosphonate and carbonate monomers linked by one or more aromatic dihydroxide and/or various segments in which several phosphonates or several carbonate monomers form phosphonate or carbonate segments. Additionally, the length of various phosphonate or carbonate segments may vary within individual copoly(phosphonate carbonate)s.

[0059] The phosphonate and carbonate content of the copoly(phosphonate carbonate)s may vary among embodiments, and embodiments are not limited by the phosphonate and/or carbonate content or range of phosphonate and/or carbonate content. For example, in some embodiments, the copoly(phosphonate carbonate)s may have a phosphorus content of from about 1% to about 20% by weight of the total copoly (phosphonate carbonate), and in other embodiments, the phosphorous content of the copoly(phosphonate carbonate)s of the invention may be from about 2% to about 10% by weight of the total polymer.

[0060] In other embodiments, the copoly(phosphonate carbonate)s or copoly (phosphonate ester)s, may have structures such as, but not limited to, those structures of Formulae IV and V, respectively:

[0061]

V

[0063] and combinations thereof, where Arl and Ar2 are each, independently, an aromatic group and -O-Arl-O- and -0-Ar2-0- may be derived from a dihydroxy compound as described by structure (II).

[0064] R is a Cl-20 alkyl, C2-20 alkene, C2-20 alkyne, C5-20 cycloalkyl, or C6-20 aryl. Rl may be a Cl-20 alkylene or cycloalky lene, such as methylene, ethylene, propylene, butylene, pentylene, and the like, and in particular embodiments, Rl can be derived from aliphatic diols such as, but not limited to, l,4-cyclohexyldimethanol, 1, 4-butane diol, 1,3- propane diol, ethylene diol, ethylene glycol, and the like and combinations thereof. R2 is, independently, a Cl-20 alkylene, C2-20 alkylenylene, C2-20 alkylynylene, C5-20 cycloalkylene, or C6-20 arylene. In certain embodiments, R2 can be derived from adipic acid, dimethyl terephthalic acid, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid and the like or derivatives thereof or combinations thereof. In certain embodiments, R2 may be an aromatic group such as naphthalene, phenylene, biphenylene, propane-2, 2- diyldibenzylene, and in some embodiments, R2 can be derived from, for example, dimethyl terephthalate, dimethyl isophthalate, dimethyl naphthalate, and the like and combinations thereof. Thus, R2 may be, for example, naphthalene, phenyl, both of which may be substituted at any position on the rings.

[0065] Such copoly(phosphonate carbonates) or copoly(phosphonate esters) may be block copoly (phosphonate carbonates) or copoly(phosphonate esters) in which each m4, n4, and p5 is greater than about 1, and the copolymers contain distinct repeating phosphonate and carbonate blocks or phosphonate and ester blocks. In other embodiments, the

copoly (phosphonate carbonates) or copoly(phosphonate esters) can be random copolymers in which each m4, n4, and p5 are each, independently, an integer from 1 to about 200, 1 to about 100, 1 to about 75, 1 to about 50, 1 to about 20, 1 to about 10, or 1 to about 5, or any integer between these ranges.

[0066] In particular embodiments, the Arl and Ar2 may be derived from bisphenol A and R may be a methyl group providing random and block co(phosphonate carbonate)s and co(phosphonate ester)s that may have structures such as, but not limited to, structures of Formulae VI and VII:

[0067] and combinations thereof, where each of m4, n4, p5, and Rl and R2 are defined as described above.

[0068] The copoly(phosphonate carbonate)s of various embodiments exhibit both a high molecular weight and a narrow molecular weight distribution (i.e., low polydispersity). For example, in some embodiments, the copoly(phosphonate carbonate)s may have a weight average molecular weight (Mw) of about 10,000 g/mole to about 100,000 g/mole as determined by GPC, and in other embodiments, the copoly(phosphonate carbonate)s may have a Mw of from about 12,000 to about 80,000 g/mole as determined by GPC. The number average molecular weight (Mn) in such embodiments may be from about 5,000 g/mole to about 50,000 g/mole, or from about 8,000 g/mole to about 15,000 g/mole, and in certain embodiments the Mn may be greater than about 9,000 g/mole. The narrow molecular weight distribution (i.e., Mw/Mn) of such copoly(phosphonate carbonate)s may be from about 2 to about 7 in some embodiments and from about 2 to about 5 in other embodiments.

[0069] Additional description of phosphonate oligomers

[0070] In some embodiments, the molecular weight (weight average molecular weight as determined by gel permeation chromatography based on polystyrene calibration) range of the obgophosphonates, random or block co-obgo(phosphonate ester)s and co-obgo(phosphonate carbonate)s may be from about 500 g/mole to about 18,000 g/mole or any value within this range. In other embodiments, the molecular weight range may be from about 1,500 g/mole to about 15,000 g/mole, about 3,000 g/mole to about 10,000 g/mole, or any value within these ranges. In still other embodiments, the molecular weight range may be from about 700 g/mole to about 9,000 g/mole, about 1,000 g/mole to about 8,000 g/mole, about 3,000 g/mole to about 4,000 g/mole, or any value within these ranges.

[0071] The oligomeric phosphonates can have about 60% to about 100% oligomer phosphonate chains of the total of oligomeric phosphonates chains that have two or more reactive end-groups.. In other embodiments, about 75% to about 99% of the total of oligomeric phosphonates have two or more reactive end-groups. In some embodiments, the reactive end-groups may be, for example, epoxy, vinyl, vinyl ester, isopropenyl, isocyanate, or combinations thereof, and in certain embodiments, about 80% to about 100% of the total oligomeric phosphonates may have two or more hydroxyl end groups. In various

embodiments, the oligomeric phosphonates or portions thereof may include

obgophosphonate, random co-obgo(phosphonate ester), block co-obgo(phosphonate ester), random co-obgo(phosphonate carbonate), block co-obgo(phosphonate carbonate), or combinations thereof. In some embodiments, the oligomeric phosphonates may include linear oligomeric phosphonates, branched oligomeric phosphonates, or a combination thereof, and in other embodiments, such oligomeric phosphonates may further include hyperbranched obgophosphonates.

[0072] Description of polymer compositions. [0073] The term "polymer composition", as used herein, refers to a composition that comprises at least one of the present inventions and at least one other polymer, oligomer, or monomer mixture. The“polymer composition” can comprise, for example, a

polyphosphonate, branched polyphosphonate, or hyberbranched polyphosphonate, random or block copolyphosphonate, co-oligo(phosphonate ester), or co-oligo(phosphonate carbonate), phosphonate oligomer, branched phosphonate oligomer, or hyperbranched phosphonate. The other polymer, oligomer, or monomer mixture may include those that comprise, or are partially comprised of, or are comprised of monomers intended to produce the following polymer families including but not limited to a polycarbonate, polyacrylate, polyacrylonitrile, polyester, polyether, polyamide, polystyrene, polyurethane, polyurea, polyurethane urea, polyepoxy, poly(acrylonitrile butadiene styrene), polyimide, polyarylate, poly(arylene ether), polyethylene, polypropylene, polyphenylene sulfide, poly(vinyl ester), polyvinyl chloride, bismaleimide polymer, polyanhydride, liquid crystalline polymer, cellulose polymer, benzoxazine resin, another polyphosphonate, or a combination of any two or more of these. The other polymer, oligomer, or monomer may contain functional groups that will react chemically.

[0074] Any epoxy resin can be used for the purpose(s) of the invention provided that the resin contains at least one glycidyl group, alicyclic epoxy group, or a similar epoxy group (i.e., oxirane or ethoxy line group). Preferable is an epoxy resin having two or more epoxy groups. Such a component can be represented by novolac-type epoxy resin, cresol-novolac epoxy resin, triphenolalkane-type epoxy resin, aralkyl-type epoxy resin, aralkyl-type epoxy resin having a biphenyl skeleton, biphenyl-type epoxy resin, dicyclopentadiene-type epoxy resin, heterocyclic-type epoxy resin, epoxy resin containing a naphthalene ring, a bisphenol- A type epoxy resin, a methylene dianiline type epoxy resin, a bisphenol-F type epoxy compound, stilbene-type epoxy resin, trimethylol-propane type epoxy resin, terpene-modified epoxy resin, linear aliphatic epoxy resin obtained by oxidizing olefin bonds with peracetic acid or a similar peracid, alicyclic epoxy resin, or sulfur-containing epoxy resin. The substrate may also be composed of two or more epoxy resins of the aforementioned types. Preferable epoxy resins are those derived from bisphenol A or methylene dianiline.

Preferable for use are aralkyl-type epoxy resins with a biphenyl structure, a bisphenol A structure or a methylene dianiline structure. The epoxy resin is typically commercially available, though this is not a requirement for applicability. The epoxy may also contain as a component a benzoxazine compound, oligomer or resin. [0075] It is contemplated that the polymer compositions of the present invention may comprise other components, such as but not limited to other flame retardants, chopped or continuous glass, metal, carbon based, or ceramic fibers; fillers, surfactants, mold release agents, organic binders, polymeric binders, crosslinking agents, coupling agents, anti dripping agents, colorants, inks, dyes, antioxidants or other stabilizers, or any combination thereof.

[0076] The present invention can be used as coatings on plastics, metals, ceramic, or wood products or they can be used to fabricate articles, such as free-standing films and extruded sheets, fibers, foams, molded articles, adhesives, filaments, and fiber reinforced composites. The compositions described herein may include additional components such as additives, fillers, and fibers, such as, but not limited to, chopped or continuous glass fiber, metal fibers, aramid fibers, carbon fibers, or ceramic fibers, surfactants, organic binders, polymeric binders, crosslinking agents, diluents, coupling agents, flame-retardant agents, anti-dripping agents such as fluorinated polyolefins, silicones, and, lubricants, mould release agents such as pentaerythritol tetrastearate, nucleating agents, anti-static agents such as conductive blacks, carbon nanotubes, graphite, graphene, oxidized graphene, and organic antistatics such as polyalkylene ethers, alkylsulfonates, perfluor sulfonic acid, perfluorbutane, sulfonic acid potassium salt, and polyamide-containing polymers, catalysts, colorants, inks, dyes, antioxidants, stabilizers, and the like and any combinations thereof. These articles may be well-suited for applications requiring fire resistance.

[0077] The present invention and polymer compositions including them exhibit outstanding flame resistance and good melt processability. Such improvements make these materials useful in applications in the automotive and electronic sectors that require outstanding fire retardancy, high temperature performance, and melt processability.

[0078] In such embodiments, the each of the additional components or additives may make up from about 0.001 wt. % to about 1 wt.%, about 0.005 wt. % to about 0.9 wt. %, about 0.005 wt. % to about 0.8 wt.%, or about 0.04 wt. % to about 0.8 wt.% of the total composition, and in particular embodiments, the additional components or additives may make up about 0.04 wt. % to about 0.6 wt.% based on the total composition. Additional components such as glass fiber, carbon fiber, organic fiber, ceramic fiber or other fillers may be provided at much concentrations up to 70 volume (vol.) %. For example, the polymer compositions of certain embodiments may include about 5 vol. % to about 70 vol. %, from about 10 vol. % to about 60 vol. %, or about 20 vol. % to about 50 vol. % glass fiber, carbon fiber, organic fiber, or ceramic fiber. [0079] Polymer compositions including novel epoxy containing phosphonate monomers, polymers, copolymers, oligomers and co-oligomers and other engineering polymers and/or additional components or additives can be prepared by conventional means. For example, in some embodiments, the compositions may be prepared by liquid epoxy curing. Such embodiments may include the steps of combining the epoxy resin, oligomeric phosphonate, and carbodiimide antioxidant or combination of carbodiimides and phenolic antioxidants or phosphite antioxidants in a solvent, and in certain embodiments, the method may include the step of combining the epoxy resin, oligomeric phosphonate, carbodiimide antioxidant or combination of carbodiimides and phenolic antioxidants or phosphite antioxidants, and a curing catalyst in a solvent. Combining may be carried out by any means including, for example, stirring or shaking the components until a substantially homogeneous mixture of components has been created. In certain embodiments, the method may include the steps of combining the epoxy resin, oligomeric phosphonate, and carbodiimide antioxidant or combination of carbodiimides and phenolic antioxidants or phosphite antioxidants to create a mixture and adding the solvent or solvent and curing agent to the mixture. This mixture may be mixed by stirring or shaking.

[0080] The form of addition of the compounds according to the invention is not limited. For example, the engineering plastics and/or additional components or additives can be added as solids such as a powder, as concentrate in solution or as a liquid.

[0081] The solvent of such embodiments may be any solvent known in the art, and in certain embodiments, the solvent may be an aprotic solvent. Aprotic solvents can include, but are not limited to, perfluorohexane, a,a,a-trifluorotoluene, pentane, hexane, cyclohexane, methylcyclohexane, decalin [c + t], dioxane, carbon tetrachloride, freon-l l, benzene, toluene, triethyl amine, carbon disulfide, diisopropyl ether, diethyl ether (ether), t-butyl methyl ether (MTBE), chloroform, ethyl acetate, 1 ,2-dimethoxy ethane (glyme), 2-methoxy ethyl ether (diglyme), tetrahydrofuran (THF), methylene chloride, pyridine (Py), methyl ethyl ketone (MEK), methyl n-amyl ketone (MAK), methyl n-propyl ketone (MPK), acetone,

hexamethylphosphoramide, N-methylpyrrolidinone, nitromethane, dimethylformamide, acetonitrile, sulfolane, dimethyl sulfoxide, propylene carbonate, and the like. In certain embodiments, the solvent may be methyl ethyl ketone (MEK) or acetone.

[0082] The amount of solvent included in the mixtures of various embodiments may be from about 25 wt. % to about 75 wt. % of the total composition, and in certain embodiments, the solvent may be about 30 wt. % to about 50 wt. % of the total composition or any concentration or range encompassed by these example ranges. [0083] Any curing agents, curing catalysts, and curing accelerator known in the art such as, but not limited to, transition metal catalysts, tertiary amines, imidazole containing compounds, and the like and combinations thereof. Examples of the tertiary amine curing catalysts include triethylamine, benzyldimethylamine, pyridine, picoline, 1,8- diazabiscyclo(5,4,0)undecene-l, dicyandiamide, and the like, and Examples of the imidazole compound include, but are not limited to 2-methylimidazole, 2-ethylimidazole, 2- undecylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2- phenyl imidazole, phosphonium salts like tetraphenyl phosphonium phenolate and ethyltriphenyl phosphonium bromide, tetrabutyl ammonium, 4-dimethylaminopyridine, and boron trifluoride-ethylamine complex and the like.

[0084] The amount of the curing catalyst may be any amount that is effective for use as a catalyst and can, generally, be from about 0.01 wt. % to about 20 wt. % based on the weight of the total composition. In some embodiments, the amount of curing catalyst may be, about 0.1 wt. % to about 15 wt. %, about 0.5 wt. % to about 10 wt. %, about 1.0 wt. % to about 5 wt. %, or any range or individual concentration encompassed by these example ranges.

[0085] The method may further include heating the mixture after the mixture has been mixed to form a substantially homogenous mixture to remove the solvent and produce a cured composition. Heating can be carried out at any suitable temperature that allows for good catalytic activity and evaporation of the solvent. In various embodiments, heating may be carried out to from about 20° C to about 250° C, about 50° C to about 200° C, about 100° C to about 150° C, or any range or individual temperature encompassed by these ranges. In certain embodiments, heating may be carried out in two or more steps. For example, a first heating step may include heating the mixture to a temperature suitable for evaporating the solvent such as, for example, about 40° C to about 150° C or about 50° C to about 100° C for a first time period, and a second heating step may including heating the mixture to a temperature suitable for curing the mixture such as, for example, about 100° C to about 250° C or about 150° C to about 200° C. The time period for heating may vary among embodiments and may vary depending on the type of solvent used. Typically, heating may be carried out from about 60 minutes to about 300 minutes or any range or individual time period encompassed by this range. In embodiments in which heating is carried out for a first and second time period, a first heating step may be carried out for about 10 minutes to about 60 minutes, about 20 minutes to about 40 minutes or about 30 minutes, and a second heating step may be carried out from about 40 minutes to about 200 minutes or about 60 minutes to about 180 minutes or any range or individual time period encompassed by this range. [0086] The polymer compositions of various embodiments can be used in any application in which a flame-retardant polymer is useful. For example, in some embodiments, the polymer compositions of the invention may be used as coatings on plastics, metals, glass, carbon, ceramic, or wood products which can be in a variety of forms, for example as a fiber, woven mat, nonwoven mat, cloth, broadgood, fabric, molding, laminate, foam, extruded shape or the like, and in other embodiments, the polymer compositions of the invention can be used in adhesives or to fabricate sheets, multilayer sheets, free-standing films, multi-layer films, fibers, foams, molded articles, and fiber reinforced composites. Such articles may be well-suited for applications requiring flame resistance. The novel epoxy containing phosphonate monomers, polymers, copolymers, oligomers and co-oligomers and polymers therefrom, and polymer compositions of the invention, may exhibit outstanding flame resistance and good melt processability making these materials useful in applications for the automotive, construction, and electronic sectors that require outstanding fire retardancy, high temperature performance, and melt processability. In addition, these articles may be well suited for a variety of applications as support parts, electrical components, electrical connectors, printed wiring laminated boards, flexible or rigid circuit boards, electrical or electromagnetic housings, electrical or electromagnetic subcomponents and components in consumer products that must meet UL or other standardized fire resistance standards and environmental standards.

[0087] In some embodiments, the polymer compositions of the invention may be combined with other components or reinforcing materials. For example, in various embodiments, continuous or chopped glass fibers, carbon black or carbon fibers, ceramic particles or fibers, organic fibers, or other organic materials may be included in the polymers and polymer compositions of the invention. In particular embodiments, continuous or chopped glass fibers, carbon fibers, ceramic fibers, organic fibers, or other organic materials may be combined with the novel epoxy containing phosphonate monomers, polymers, copolymers, oligomers and co-oligomers and polymers therefrom, and polymer compositions of the invention to create a prepreg to prepare laminates. Such laminates may be used to fabricate components such as flexible or rigid laminated circuit boards that can be incorporated into articles of manufacture such as electronic goods such as, for example, televisions, computers, laptop computers, tablet computers, printers, cell phones, video games, DVD players, stereos, electronic applications for automotive, and other consumer electronics. [0088] The polymer compositions of the invention are generally self-extinguishing, i.e., they stop burning when removed from a flame and any drops produced by melting in a flame stop burning are almost instantly extinguishes and do not readily propagate fire to any surrounding materials. Moreover, these polymer compositions do not evolve noticeable smoke when a flame is applied.

EXAMPLES

[0089] To further elucidate various aspects of the invention, the following working examples are provided. The examples are provided only for illustrative purposes and are not intended necessarily to present optimal practice of the invention and/or optimal results that may be obtained by practicing the invention.

[0090] Materials

[0091] Bisphenol-A Epoxy resin Epon 828 (E828-EP) and phenolic novolac Epon 154 (E154-EP) were obtained from Momentive (currently Hexion). Hydantoin epoxy 1,3- Diglycidyl-5,5-dimethylhydantoin polymer (Hyd-EP) MHR-070 was obtained from Hubei Xitai Chemical Company and 9,l0-dihydro-9-oxa-l0-phosphaphenanthrene-l0-oxide (DOPO) based epoxy (DOPO-EP) with 3% P (phenolic-type DOPO epoxy) and 6%P (DGEBA-type DOPO epoxy) content was obtained from Wuxi Dahe Polymer Materials Company. The catalysts 2-ethyl-4-methyl-imidazole (2E4MI) was obtained from Alfa Aesar and tetraphenylphosphonium phenolate (TPPP) from Feihe Chemical Co. Ltd). Nofia OL3001 phosphonate oligomer was obtained from FRX Polymers and 4,4-diaminodiphenyl sulfone (DDS) obtained from Alfa Aesar.

[0092] Methods

[0093] DSC: glass transition temperatures (Tg) were measured using Differential Scanning Calorimeter (DSC) with the TA Instruments Q2000 model. Samples were heated from 30 °C to 225 °C at a ramp rate of 10 °C/min. Phosphorus content was determined using acid digestion, complexation with molybdate, and analysis of phosphomolybdenum blue using photometric quantification (derived from ISO 6878). Measurement of Comparative Tracking Indices (CTI) was performed according to GB/T 4207-2012 standard test method, tensile properties were tested according to the IS0527-4: l997 and flexural properties according to ISO 178:2013 test method.

[0094] GPC : Molecular weight distributions were determined by measuring 0.2 % solutions of polymer in tetrahydrofuran by gel permeation chromatography (GPC) with UV detection (at 254 nm). Calibration of the instrument was conducted with linear polystyrene (PS) standards of known molecular weights. The weight average (Mw), number average (Mn) and polydispersity (Mw/Mn), referred to as PD, were evaluated from the

chromatograms by using WinGPC.

[0095] Flame Retardancy Test

[0096] Laminate samples of 3 mm thickness were tested according to the UL-94 vertical bum test specifications, which tests the burning properties of a sample after a flame is applied for 10 seconds, observed, and then the flame re-applied for a second 10 seconds.

[0097] Varnish Preparation

[0098] Varnish compositions containing the epoxy resins, the phosphonate oligomer Nofia OL3001, and catalyst were prepared by dissolving them in methyl ethyl ketone (MEK) at 70 wt.% solids. Nofia OL3001 was first dissolved in the MEK before adding the epoxy resins. Additional hardeners and/or flame retardants were dissolved in the epoxy resin-oligomer solution before adding the catalyst at the end. Catalysts 2-ethyl-4-methyl-imidazole (2E4MI) was tested at loading levels of 0. l-0.3wt% and tetraphenylphosphonium phenolate at loading levels of 0.5 to l.7wt%.

[0099] Prepreg and Laminate Preparation

[0100] Prepregs were prepared using 7628 glass fabric and various b-staging temperatures ranging from 150 °C to 180 °C. Laminates were prepared by stacking 21 prepreg layers in a press and heating from room temperature to 200 °C at a heating rate of 3 °C/min. Typical lamination conditions were 200 °C for 90 minutes. Pressure range in the press was from 10 to 300 psi. Resin content of the cured laminates was -30%.

[0101] Examples 1-13 and Comparative Examples 1-2

[0102] Examples 1 and 2 shows the failure to meet 600V CTI when bisphenol A epoxy is used as the base resin. Example 3 shows the replacement of 20 wt% bisphenol-A epoxy resin (E828) with hydantoin-type epoxy in the formulation with Nofia OL3001 phosphonate hardener can meet or surpass the 600V requirement.

[0103] Example 4 and 5 show further replacement of 20 wt% bisphenol A epoxy resin with 3%P DOPO-epoxy and 6%P DOPO-epoxy respectively, both fail to meet the 600V CTI requirement. The formulation with 20wt% of the higher P content epoxy ( 6%P DOPO) (Example 5) met the V0 requirement, while the 3%P DOPO epoxy failed to meet V0.

[0104] Examples 6 and 7 show that reducing the content of 6%P DOPO-epoxy to 10- l5wt% the laminates are able to meet the >600 CTI requirement but fail the V0 requirement. This indicates at >l5wt% loadings, the DOPO structure leads to reduction of the CTI. On the contrary, Nofia OL3001 loading levels of 38-39wt% do not negatively impact the CTI. [0105] Addition of DDS as a co-hardener with Nofia OL3001 in Examples 8-10 show the laminates can pass both the 600V CTI and V0 requirements. Increasing the hydantoin epoxy composition from 25 to 36 wt% does not reduce the CTI.

[0106] In Examples 11, l0wt% of the 6%P DOPO epoxy was replaced with the DOPO hardener (D92741) and the laminate did not pass the 600V CTI requirement. Since the DOPO hardener has a higher %P (9%), it further indicates that the presence of DOPO in the structure adversely affects the CTI. Replacement of bisphenol A epoxy with phenolic epoxy (Example 3 vs 13) shows the phenolic epoxy structure has a negative impact on CTI.

[0107] Laminate properties for various compositions using OL3001 as the primary hardener and flame retardant are shown in Table 1 (Examples 1-13). Comparative examples 1 and 2 Comp 1-2) use DDS as the sole hardener and DOPO based epoxy as the flame retardant.

Table 1

[0108] In conclusion, Nofia phosphonate oligomers (OL3001) incorporated into epoxy- based glass fabric laminates as both hardener and FR, do not have an adverse effect on the CTI. Laminates can meet high CTI requirements of >600 V and achieve V0 (UL94) flame retardant requirements. In comparison, DOPO-epoxy or DOPO-type hardeners can only be used in limited quantities as they have an adverse effect on the CTI and cannot be used to achieve CTI > 600 V and meet V0. Phenolic structures (phenolic-epoxy or phenolic based hardeners) have negative impact on CTI while bisphenol A structures are less susceptible to CTI failure. Hydantoin epoxy resin can also be used to improve the CTI values when used in combination with bisphenol- A epoxy resins.

[0109] Glass Transition Temperature (Tg) Properties

[0110] Glass transition temperatures of a selected number of laminates from Table 1 is shown in Table 2.

Example Tg (° C)

Ϊ 145

3 149

10 120

13 133

[0111] Mechanical Properties

[0112] Mechanical properties of the laminate prepared from the composition shown in Example 3 versus the control sample and target properties. The results are shown in Table 3.

Table 3

Example Example Control Target

3

Tensile Strength (MPa) at 23 °C 410 520 >450

Tensile Modulus (GPa) at 23 °C 24 35 >20

Flexural Strength (MPa) at 23 510 612 >500

°C

Flexural Modulus (GPa) at 23 26 33 >20

°C [0113] Those skilled in the art will know or be able to ascertain using no more than routine experimentation, many equivalents to the embodiments and practices described herein. Accordingly, it will be understood that the invention is not to be limited to the embodiments disclosed herein, but is to be understood from the following claims, which are to be interpreted as broadly as allowed under the law.

[0114] The section headings used herein are for organizational purposes only and are not to be construed as limiting. While the applicant’s teachings are described in conjunction with various embodiments, it is not intended that the applicant’s teachings be limited to such embodiments. On the contrary, the applicant’s teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art.

Claims

What is claimed is:

1. A halogen free thermosetting resin composition comprising:

an epoxy resin;

and

a phosphonate oligomer or phosphonate polymer,

wherein the composition is used to make a fiber reinforced laminate that has a comparative tracking index of at least 600 V.

2. The composition of claim 1 that further comprising a second resin selected from a hydantoin based resin or a dicyclopentadiene based resin;

3. The composition of claim 1, further comprising a second co-hardener

4. The composition of claim 1, further comprising a second flame retardant.

5. The composition of claim 1, wherein the laminate prepared from the thermosetting resin achieves a VO flame retardant rating at 3mm.

6. The composition of claim 1, wherein the epoxy resin is selected from the group

consisting of bisphenol-A epoxy resin, bisphenol-F epoxy resin, bisphenol A novolac epoxy resin, biphenol novolac epoxy resin, and dicyclopentadiene novolac epoxy resin, or any combinations thereof.

7. The composition of claim 1, wherein the hydantoin based resin is l,3-diglycidyl-5,5- dimethylhydantoin polymer, 5,5-bis(4-hydroxyphenyl)hydantoin polymer, or a combination thereof.

8. The composition of claim 1, further comprising a curing accelerator selected from the group consisting of imidazole compounds 2-ethyl-4-methyl imidazole, 2-phenyl imidazole, 2-methyl imidazole, phosphonium salts like tetraphenyl phosphonium phenolate and ethyltriphenyl phosphonium bromide, tetrabutyl ammonium, 4- dimethylaminopyridine, and boron trifluoride-ethylamine complex, or any combinations thereof.

9. A method for preparing a prepreg comprising:

impregnating a reinforcing material with the halogen-free thermosetting resin composition of claim 1.

10. The method of claim 9, further comprising drying and b-staging in an oven the

prepreg.

11. A method for preparing a laminate comprising:

layering at least one prepreg of claim 10.

12. An article of manufacture comprising:

a laminate of claim 11,

wherein the article of manufacture is a fiber reinforced composite, an electrical component, or a printed circuit board.