Combined flame retardants and stabilizers for use with thermoplastics

Abstract

The present disclosure relates to a novel flame retardant and stabilizer additive composition for thermoplastic polymers, as described herein, the additive composition comprising at least one phosphorus-containing flame retardant and at least one epoxide. The additive composition disclosed herein can be used in a wide range of thermoplastic applications, particularly in thermoplastic polymers that are processed and / or used at high temperatures.

Description

[0001] The present disclosure relates to a flame retardant and stabilizer additive composition for thermoplastic polymers, and to flame retardant thermoplastic compositions comprising the combined flame retardant and stabilizer.

[0002] During melt processing of thermoplastics, various additives are often added for various purposes, such as antioxidants, lubricants, stabilizers, flame retardants, etc. Although flame retardant additives are necessary to provide flame retardancy to thermoplastics, during melt processing, flame retardant additives may affect the stability of thermoplastics, such as by increasing polymer degradation and / or discoloration. For example, these types of effects have been discussed and reported in the literature for certain phosphorus-containing flame retardants, such as described in U.S. Pat. Nos. 7,255,814 and 9,534,109 for phosphinate flame retardants.

[0003] The present disclosure provides a new phosphorus-containing flame retardant and stabilizer additive composition for thermoplastic polymers. The phosphorus-containing flame retardants disclosed herein (also described in the applicant's co-pending patent application numbers PCT / US 2019 / 067184 and PCT / US 2019 / 067230) provide additional benefits of being compounded into thermoplastic polymers (such as high temperature polyamides and polyterephthalates) at high temperatures without decomposing due to the high thermal stability of these phosphorus-containing flame retardants. Therefore, the additive composition disclosed herein can be used in a wide range of thermoplastic applications, particularly in thermoplastic polymers processed and / or used at high temperatures.

[0004] In particular, the present disclosure provides a flame retardant and stabilizer additive composition for thermoplastic polymers, the composition comprising

[0005] (A) at least one phosphorus-containing flame retardant having the empirical formula (I):

[0006]

[0007] wherein R is H, alkyl, aryl, alkylaryl or arylalkyl, M is a metal, and y is 2 or 3 such that M (+)y is a metal cation, wherein (+)y represents the charge formally assigned to the cation, a, b and c represent the ratios of the components to which they correspond in the compound relative to each other and satisfy the charge balance equation 2(a)+c=b(y), and c is not zero, and

[0008] (B) at least one epoxide compound. The epoxide compound preferably has at least two epoxy groups. In many embodiments, at least one epoxy group is terminal.

[0009] Flame Retardants and Stabilizers The additive composition may further comprise (C) at least one flame retardant synergist and / or additional flame retardants. The additive composition may additionally comprise (D) one or more other stabilizers.

[0010] The present disclosure further provides a flame retardant thermoplastic composition comprising

[0011] (i) at least one thermoplastic polymer,

[0012] (ii) at least one phosphorus-containing flame retardant having the above empirical formula (I), and

[0013] (iii) at least one epoxide compound as described above. The flame retardant thermoplastic composition may further comprise (iv) at least one inorganic filler (e.g. glass fibers), (v) at least one flame retardant synergist and / or additional flame retardant, (vi) one or more additional stabilizers, and / or (vii) one or more additional additives that enhance the properties of the thermoplastic composition.

[0014] The foregoing summary is not intended to limit the scope of the claimed invention in any way. Furthermore, it is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown are the results of thermogravimetric analysis (TGA) of an exemplary phosphorus-containing flame retardant produced according to Example 1 of the present disclosure.

[0016] Figure 2 Shown are the results of thermogravimetric analysis (TGA) of an exemplary phosphorus-containing flame retardant produced according to Example 7 of the present disclosure. DETAILED DESCRIPTION

[0017] Unless otherwise specified, the words "a" or "an" in this application mean "one or more than one".

[0018] Unless the context indicates otherwise, the term "alkyl" in the present application includes "arylalkyl".

[0019] Unless the context indicates otherwise, the term "aryl" in this application includes "alkylaryl".

[0020] As used herein, unless the context indicates otherwise, the term "phosphonic acid" refers to an unsubstituted or alkyl or aryl substituted phosphonic acid.

[0021] Unless the context indicates otherwise, the term "pyrophosphonic acid" as used herein refers to unsubstituted or alkyl or aryl substituted pyrophosphonic acid.

[0022] As noted above, the present disclosure provides a new phosphorus-containing flame retardant and stabilizer additive composition for thermoplastic polymers.

[0023] The present disclosure provides a flame retardant and stabilizer additive composition for thermoplastic polymers, the composition comprising

[0024] (A) at least one phosphorus-containing flame retardant having the empirical formula (I):

[0025]

[0026] wherein R is H, alkyl, aryl, alkylaryl or arylalkyl, M is a metal, and y is 2 or 3 such that M (+)y is a metal cation, wherein (+)y represents the charge formally assigned to the cation, a, b and c represent the ratios of the components to which they correspond in the compound relative to each other and satisfy the charge balance equation 2(a)+c=b(y), and c is not zero, and

[0027] (B) at least one epoxide compound.

[0028] The at least one phosphorus-containing flame retardant (component (A)) of the present disclosure has the following empirical formula:

[0029]

[0030] wherein R is H, alkyl, aryl, alkylaryl or arylalkyl, M is a metal and y is 2 or 3, such that M (+)y Is a metal cation, wherein (+) y represents the charge formally assigned to the cation, a, b and c represent the ratios of these components to which they correspond relative to each other in the compound, and satisfy the charge balance equation 2 (a) + c = b (y), and c is not zero. Typically, a is 0, 1 or 2 (e.g., 0 or 1), b is from 1 to 4 (e.g., 1 or 2), and c is 1 or 2, and the product is charge balanced. Examples of suitable metals (M) include, but are not limited to, Al, Ga, Sb, Fe, Co, B, Bi, Mg, Ca and Zn.

[0031] As with inorganic coordination compounds, formula (I) is empirical or idealized, so that these compounds can be coordination polymers, complex salts, salts sharing certain atomic valences, etc. For example, in many embodiments, the empirical formula (I) represents a monomer unit (i.e., coordination entity) of a coordination polymer, and the extended coordination polymer structure thus forms the phosphorus-containing flame retardant of the present disclosure.

[0032] In certain embodiments, y in Formula (I) is 2 (ie, M (+)yis a divalent cation metal), a is 0, b is 1, and c is 2. In certain embodiments, the divalent cation metal M is Mg, Ca, or Zn. In other embodiments, in Formula (I), y is 3 (i.e., M (+)y is a trivalent cationic metal), a is 1, b is 1, and c is 1. In certain embodiments, the trivalent cationic metal M is selected from Al, Ga, Sb, Fe, Co, B, and Bi. In certain embodiments, the trivalent cationic metal M is Al, Fe, Ga, Sb, or B.

[0033] In one example, M is Al and y is 3, and the phosphorus-containing flame retardant has the following empirical formula:

[0034]

[0035] As shown herein, the absence of subscripts a, b, and c in the empirical formula indicates that each subscript is 1, indicating that the ratio of the di-anionic pyrophosphonic acid ligand, the metal atom, and the mono-anionic pyrophosphonic acid ligand is 1:1:1. In many embodiments, the empirical formula (II) represents the repeating monomer units (i.e., coordination entities) of the coordination polymer, and the extended coordination polymer structure thus forms the phosphorus-containing flame retardant of the present disclosure.

[0036] Usually, R is H, C 1-12 Alkyl, C 6-10 Aryl, C 7-18 Alkyl aryl, or C 7-18 Arylalkyl, wherein the alkyl, aryl, alkylaryl, or arylalkyl is unsubstituted or substituted with halogen, hydroxy, amino, C 1-4 Alkylamino, di-C 1-4 Alkylamino, C 1-4 Alkoxy, carboxyl or C 2-5 In some embodiments, the alkyl, aryl, alkylaryl, or arylalkyl is unsubstituted C 1-12 Alkyl, C6 aryl, C 7-10 Alkyl aryl, or C 7-10 Arylalkyl, for example, C 1-6 Alkyl, phenyl, or C 7-9 In some embodiments, R is substituted or unsubstituted C 1-6 Alkyl, C6 aryl, C 7-10 Alkyl aryl, or C 7-12 Arylalkyl, for example, C 1-4 Alkyl, C6 aryl, C 7-9 Alkyl aryl, or C 7-10 In many embodiments, R is an unsubstituted C 1-12 Alkyl groups, such as C 1-6In many embodiments, lower alkylphosphonic acids are used, for example, methyl-, ethyl-, propyl-, isopropyl-, butyl-, tert-butyl-, etc.

[0037] R as alkyl can be a straight or branched alkyl with a specific number of carbons, and includes, for example, unbranched alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and branched alkyl such as isopropyl, isobutyl, sec-butyl, tert-butyl, ethylhexyl, tert-octyl, etc. For example, R as alkyl can be selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl. In many embodiments, R is methyl, ethyl, propyl or isopropyl, such as methyl or ethyl.

[0038] Typically, when R is aryl, it is phenyl. Examples of R as alkylaryl include phenyl substituted with one or more alkyl groups, for example, the alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, etc. Examples of R as arylalkyl include, for example, benzyl, phenethyl, styryl, cumyl, phenylpropyl, etc.

[0039] In many embodiments, R is selected from methyl, ethyl, propyl, isopropyl, butyl, phenyl and benzyl. In certain embodiments, R is methyl, ethyl, propyl, isopropyl or butyl and M is Al, Fe, Zn or Ca.

[0040] The phosphorus-containing flame retardant of the present disclosure may be a mixture of compounds having the empirical formula (I).

[0041] Compared with the phosphorus-containing flame retardants described in the art, the phosphorus-containing flame retardants disclosed herein have a high phosphorus content (i.e., the ratio of phosphorus atoms to metal atoms (P to M) is higher). For example, trivalent cationic metals (e.g., aluminum) and divalent cationic metals (e.g., zinc) are known to form trisubstituted and disubstituted charge-balanced compounds, respectively. As seen in the art, aluminum triphosphonates—having a phosphorus-aluminum ratio of 3:1—and zinc diphosphonates—having a phosphorus-zinc ratio of 2:1—are referred to as flame retardants. However, according to the formation of the pyrophosphonic acid ligands disclosed herein, the ratio of phosphorus to metal in the flame retardant product is higher. For example, as shown in the examples disclosed herein, in the resulting flame retardant product, the ratio of phosphorus to aluminum, or the ratio of phosphorus to iron is 4:1.

[0042] For component (B), epoxide compounds are known and can be produced according to known methods, such as described in US Patent Publication US 2019 / 0016853 A1. The epoxide compound preferably has at least two epoxy groups. In many embodiments, at least one epoxy group is a terminal. Typically, the epoxide compound has two terminal epoxy groups. The epoxide compound may contain aromatic and / or aliphatic moieties. Typically, the epoxide compound is an aromatic epoxide compound, such as an aromatic epoxide compound with two terminal epoxy groups.

[0043] The epoxide compound may have an epoxide equivalent weight of not more than 2000, such as not more than 1000, for example 100-1000 g / equivalent. Epoxide equivalent weight (EEW) is defined as the weight of the epoxide compound in grams containing one gram-equivalent of epoxide.

[0044] Preferred epoxide compounds include polyglycidyl ethers or poly(β-methylglycidyl) ethers, preferably obtainable by reacting a compound having at least two free alcoholic or phenolic hydroxyl groups and / or by reacting a phenolic hydroxyl group with a substituted epichlorohydrin.

[0045] For example, the polyglycidyl ether or poly(β-methylglycidyl) ether can be derived from an acyclic alcohol, such as an alkylene glycol or polyoxyalkylene glycol, for example ethylene glycol, diethylene glycol and higher poly(oxyethylene) glycols, propane-1,2-diol or poly(oxypropylene) glycol, propane-1,3-diol, butane-1,4-diol, poly(oxytetramethylene) glycol, pentane-1,5-diol, and hexane-1,6-diol, hexane-2,4,6-triol, glycerol, 1,1,1-trimethylpropane, ditrimethylolpropane, pentaerythritol, sorbitol, or from polyepichlorohydrin.

[0046] Alternatively, preferred polyglycidyl ethers or poly(β-methylglycidyl) ethers are derived from cycloaliphatic alcohols such as 1,3- or 1,4-dihydroxycyclohexane, bis(4-hydroxycyclohexyl)methane, 2,2-bis(4-hydroxycyclohexyl)propane or 1,1-bis(hydroxymethyl)cyclohex-3-ene, or they contain an aromatic nucleus based on N,N-bis(-8,2-hydroxyethyl)aniline or p,p′-bis(2-hydroxyethylamino)diphenylmethane.

[0047] Preferred epoxide compounds may also be based on monocyclic phenols (e.g., resorcinol or hydroquinone) or polycyclic phenols (e.g., bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, or 4,4'-dihydroxydiphenylsulfone), or may be derived from condensation products of alcohols (e.g., phenol) and formaldehyde, such as phenol novolacs. Exemplary phenol novolacs include, but are not limited to, cresol novolacs, bisphenol A novolacs, and bisphenol F novolacs. In some embodiments, the epoxide compound is a phenol novolac polyglycidyl ether having formula (III):

[0048]

[0049] Wherein in formula (III), R is independently selected from the group consisting of: hydrogen, halogen, alkyl, alkoxy, aryl, alkylaryl and aralkyl, and n is 0 to 1000, such as from 0 to 100, wherein n represents an average number. In many embodiments, the alkyl contains from 1 to 10 carbon atoms. In many embodiments, the alkyl and / or the alkoxy contain from 1 to 4 carbon atoms. In some embodiments, n is from 0 to 10, such as from 1 to 8, from 1 to 6 or from 2 to 3, wherein n represents an average number. In a specific embodiment, R is an alkyl (e.g., methyl).

[0050] Preferred phenolic novolacs are cresol novolacs (m-, p-, or o-cresol novolacs). An example of a preferred aromatic epoxide compound having two terminal epoxy groups is a polyglycidyl ether of a cresol novolac, preferably an o-cresol novolac. In many embodiments, the polyglycidyl ether of a cresol novolac has an epoxy equivalent weight (according to ASTM D 1652) ranging from 100 to 600 g / equivalent, such as ranging from 150 to 500 g / equivalent, or from 180 to 250 g / equivalent. In specific embodiments, the at least one epoxide compound has formula (IV):

[0051]

[0052] wherein n is from 0 to 1000, such as from 0 to 100 (eg, from 0 to 10, from 1 to 8, from 1 to 6, or from 2 to 3), wherein n represents an average.

[0053] Another example of a preferred aromatic epoxide compound having two terminal epoxy groups is the oligomeric reaction product of bisphenol A and epichlorohydrin represented by formula (V):

[0054]

[0055] Wherein a is 0 to 1000, such as from 0 to 100 (e.g., from 0 to 10, from 1 to 8, from 1 to 6, or from 2 to 3), wherein a represents an average number. In a particular embodiment, the oligomerization reaction of bisphenol A with epichlorohydrin as described above has an epoxy equivalent weight ranging from 450 to 600 g / equivalent (according to ASTM D1652).

[0056] In many embodiments, the at least one epoxide compound has a melting point according to ASTM D3461 ranging from 0°C to 160°C, such as 50°C to 120°C, from 60°C to 110°C, or from 70°C to 90°C.

[0057] The flame retardant and stabilizer additive composition may further comprise at least one flame retardant synergist and / or additional flame retardant (component (C)). Examples of suitable flame retardant synergists include condensation products of melamine (e.g., melam, melamine, cyanuric acid), melamine cyanurate, reaction products of melamine with polyphosphoric acid (e.g., dimelamine pyrophosphate, melamine polyphosphate), reaction products of condensation products of melamine with polyphosphoric acid (e.g., melem polyphosphate, melam polyphosphate, cyanuric acid), melamine-poly(metal phosphate) (e.g., melamine-poly(zinc phosphate)), triazine-based compounds (e.g., trichlorotriazine, reaction products of piperazine and morpholine, for example, poly-[2,4-(piperazine-1,4-yl)-6-(morpholin-4-yl)-1,3,5-triazine] / piperazine (e.g., PPM Triazine HF)), metal hypophosphites such as aluminum hypophosphite (e.g., Italmatch IP-A), organic phosphinates such as aluminum dialkylphosphinates (e.g., aluminum diethylphosphinate (Exolit OP)). In many embodiments, nitrogen-containing synergists are used. Suitable nitrogen-containing synergists can be selected from, for example, melamine derivatives such as melamine and its condensation products (melamine, melem, cyanuramide or similar compounds with a higher degree of condensation), melamine cyanurate, and phosphorus / nitrogen compounds such as dimelamine phosphate, dimelamine pyrophosphate, melamine phosphate, melamine pyrophosphate, polymelamine phosphate, polyphosphite, melam, polyphosphite cyanuramide, and polyphosphite melem, and mixed polymeric salts thereof. Examples of additional flame retardants suitable for the flame retardant and stabilizer additive composition of the present invention include halogenated flame retardants, alkyl or aryl phosphine oxide flame retardants, alkyl or aryl phosphate flame retardants, alkyl or aryl phosphonates, alkyl or aryl phosphinates, and salts of alkyl or aryl phosphinic acids.

[0058] The additive composition may additionally comprise one or more other stabilizers (component (D)). Examples of suitable additional stabilizers include metal hydroxides, oxides, oxide hydrates, borates, molybdates, carbonates, sulfates, phosphates, silicates, siloxanes, stannates, mixed oxide-hydroxides, oxide-hydroxide-carbonates, hydroxide-silicates, hydroxide-borates, preferably wherein the metal is zinc, magnesium, calcium or manganese, typically zinc. In many embodiments, the additional stabilizer is selected from zinc borate, zinc stannate, zinc molybdate complexes (e.g., Kemgard 911B), zinc molybdate / magnesium hydroxide complexes (e.g., Kemgard MZM), zinc molybdate / magnesium silicate complexes (Kemgard 911C), calcium molybdate / zinc complexes (e.g., Kemgard 911A) and zinc phosphate complexes (e.g., Kemgard 981), polysiloxanes, montmorillonite, kaolinite, halloysite and hydrotalcite.

[0059] The quantitative proportions of components (A), (B), (C) and (D) in the flame retardant and stabilizer additive composition can vary and generally depend on, for example, the intended application, processing conditions, etc. In many embodiments, the flame retardant and stabilizer additive composition comprises from 40 to 99.9 wt%, such as from 50 to 95 wt%, or from 50 to 80 wt% of at least one phosphorus-containing flame retardant (A), from 0.1 to 10 wt%, such as from 0.5 to 5 wt% of at least one epoxide (B), from 0 to 80 wt%, such as from 10 to 60 wt%, or from 20 to 50 wt% of at least one flame retardant synergist and / or additional flame retardant (C), and from 0 to 35 wt%, such as from 0 to 10 wt% of one or more other stabilizers (D), all weight percentages being based on the total weight of the additive composition.

[0060] The present disclosure further provides a flame retardant thermoplastic composition comprising

[0061] (i) at least one thermoplastic polymer,

[0062] (ii) at least one phosphorus-containing flame retardant having the above empirical formula (I), and

[0063] (iii) at least one epoxide as described above. The flame retardant thermoplastic composition may further comprise (iv) at least one inorganic filler (e.g., glass fibers), (v) at least one flame retardant synergist and / or additional flame retardant, (vi) one or more additional stabilizers, and / or (vii) one or more additional additives that enhance the properties of the thermoplastic composition.

[0064] At least one thermoplastic polymer (i) is typically present in the flame retardant thermoplastic composition in an amount of from 30 to 95 wt%, such as from 40 to 90 wt% or from 50 to 90 wt%, based on the total weight of the flame retardant thermoplastic composition. At least one thermoplastic polymer can be a thermoplastic polyester, polyamide, polystyrene, including high impact polystyrene (HIPS), polyolefin, polycarbonate, polyurethane, polyphenylene ether or other thermoplastic polymer. In many embodiments, the thermoplastic polymer includes a polyester (e.g., polyalkylene terephthalate) or a polyamide. In many embodiments, the thermoplastic polymer includes a polyamide. More than one thermoplastic polymer (thermoplastic polymer blend) can be used, such as a polyphenylene ether / styrene resin blend, polyvinyl chloride / acrylonitrile butadiene styrene (ABS) or other impact-modified polymers, such as ABS containing methacrylonitrile and α-methylstyrene, as well as polyester / ABS or polycarbonate / ABS. The thermoplastic polymer may be unreinforced or reinforced, for example glass reinforced, such as a glass-filled polyester (eg glass-filled polyalkylene terephthalate) or a glass-filled polyamide.

[0065] Examples of thermoplastic polyesters include homopolyesters and copolyesters obtained by polycondensation of an acid component and a diol component. For example, suitable polyesters may be selected from polybutylene terephthalate and polyethylene terephthalate.

[0066] The diol component may contain one or more of the following diols: ethylene glycol, trimethylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, hexamethylene glycol, decanediol, cyclohexanedimethanol or neopentyl glycol. The acid component may contain one or more of the following acids: terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, p-hydroxybenzoic acid, sebacic acid, adipic acid and polyester-forming derivatives thereof.

[0067] In many embodiments, the thermoplastic polyester is selected from poly(ethylene terephthalate), poly(1,3-propylene terephthalate), poly(1,4-butylene terephthalate), and blends thereof. For example, the thermoplastic polyester blend may contain from about 1 to about 99 parts by weight of one polyester and from about 99 to about 1 part by weight of a different polyester based on 100 parts by weight of the two components combined. Poly(1,4-butylene terephthalate) may be obtained by polymerizing a diol component consisting of at least 70 mol%, such as at least 80 mol%, of 1,4-butanediol with an acid component consisting of at least 70 mol%, such as at least 80 mol%, of terephthalic acid and / or its polyester-forming derivatives.

[0068] Thermoplastic polyamides include polyamides derived from diamines and dicarboxylic acids, polyamides obtained from aminocarboxylic acids (including combinations with diamines and / or dicarboxylic acids), and polyamides derived from lactams (including combinations with diamines and / or dicarboxylic acids). Examples of suitable polyamides include aliphatic polyamides such as polyamide-4,6, polyamide-6, polyamide-6,6, polyamide-6,10, polyamide-6,12, polyamide-11 and polyamide-12; polyamides obtained from aromatic dicarboxylic acids (such as terephthalic acid and / or isophthalic acid) and aliphatic diamines (such as hexamethylenediamine or nonamethylenediamine); polyamides obtained from aliphatic dicarboxylic acids (such as adipic acid and / or azelaic acid) and aromatic diamines (such as metaxylylenediamine); polyamides obtained from aromatic and aliphatic dicarboxylic acids (such as terephthalic acid and adipic acid) and aliphatic diamines (such as hexamethylenediamine); polyamides obtained from adipic acid, azelaic acid and 2,2-bis-(p-aminocyclohexyl)propane; and polyamides obtained from terephthalic acid and 4,4'-diaminodicyclohexylmethane. Mixtures and / or copolymers of two or more of the aforementioned polyamides or prepolymers thereof, respectively, may also be used.

[0069] The polyamides may be prepared by any known method, such as by polymerization of a monoaminomonocarboxylic acid or its lactam having at least two carbon atoms between the amino and carboxylic acid groups, a diamine having at least two carbon atoms between the amino and dicarboxylic acid groups in substantially equimolar proportions, or a monoaminocarboxylic acid or its lactam as defined above, together with a diamine and a dicarboxylic acid in substantially equimolar proportions. The dicarboxylic acids may be used in the form of their functional derivatives, such as salts, esters or acid chlorides.

[0070] Polyamides having a melting point of at least 280° C. are widely used for the production of molding compositions which make it possible to produce, for example for the electrical and electronics industry, molded articles which have excellent dimensional stability at high temperatures and which have very good flame retardant properties. Molding compositions of this type are required, for example, in the electronics industry for the production of components which are mounted on printed circuit boards according to the so-called surface mount technology, SMT. In this application, these components have to withstand temperatures of up to 270° C. for short periods of time without dimensional changes.

[0071] Such high temperature polyamides include certain polyamides produced from alkyl diamines and diacids, such as polyamide 4,6. In addition, many high temperature polyamides are aromatic and semi-aromatic polyamides, i.e., homopolymers, copolymers, terpolymers, or higher polymers derived from monomers containing aromatic groups. Aromatic or semi-aromatic polyamides may be used, or blends of aromatic and / or semi-aromatic polyamides may be used. Blends with aliphatic polyamides may also be used.

[0072] Examples of suitable high temperature aromatic or semi-aromatic polyamides include polyamide-4,T, poly(m-xylene adipamide) (polyamide-MXD,6), poly(dodecanediamine terephthalamide) (polyamide-12,T), poly(decanediamine terephthalamide) (polyamide-10,T), poly(nonanediamine terephthalamide) (polyamide-9,T), hexamethylene adipamide / hexamethylene terephthalamide copolyamide (polyamide-6,T / 6,6 ), hexamethylene terephthalamide / 2-methylpentamethylene terephthalamide copolyamide (polyamide-6, T / D, T); hexamethylene adipamide / hexamethylene terephthalamide / isophthalamide copolyamide (polyamide-6, 6 / 6, T / 6, I); poly (caprolactam-hexamethylene terephthalamide) (polyamide-6 / 6, T); hexamethylene terephthalamide / isophthalamide (polyamide-6, T / 6, I) copolymer; etc.

[0073] Therefore, certain embodiments of the present invention are directed to compositions comprising polyamides that melt at elevated temperatures, such as 280°C or higher, 300°C or higher, or 320°C or higher. In some embodiments, the polyamide has a melting temperature of from 280°C to 340°C, such as polyamide 4,6 or the aromatic and semi-aromatic polyamides described above.

[0074] Preferred polyamides are polyamide-6, polyamide-6,6, polyamide-11, polyamide-12, polyphthalamides such as polyamide-4,T, polyamide-6,T / 6,6 and polyamide-6,6 / 6,T / 6,I copolymers, glass-filled polyamides thereof and blends thereof. For example, the thermoplastic polyamide blend may contain from about 1 to 99 parts by weight of one polyamide and from about 99 to about 1 part by weight of a different polyamide based on 100 parts by weight of the two components combined.

[0075] In some embodiments, the polymer is a thermoplastic elastomer (eg, a thermoplastic polyolefin or a thermoplastic polyurethane). In some embodiments, the thermoplastic elastomer is a thermoplastic polyurethane.

[0076] At least one phosphorus-containing flame retardant (ii) is as described above and is present in the flame retardant thermoplastic composition in a flame retardant effective amount. Typically, the phosphorus-containing flame retardant disclosed herein is present in an amount from 1 to 30 wt%, such as 3 to 25 wt%, based on the total weight of the flame retardant thermoplastic composition.

[0077] The at least one epoxide compound (iii) in the flame retardant thermoplastic composition is as described above and is typically present in the flame retardant thermoplastic composition in an amount from 0.01 or 0.1 to 2 wt %, such as from 0.01 or 0.1 to 1 wt %, from 0.1 to 0.5 wt %, or from 0.1 to 0.3 wt %, based on the total weight of the composition.

[0078] At least one inorganic filler (iv) may be present in the flame retardant thermoplastic composition. As known in the art, inorganic fillers can reduce the molding shrinkage coefficient and the linear expansion coefficient of the resulting molded product, and improve high and low thermal shock properties. According to the desired product, various fillers (such as powders, plates) in fiber or non-fiber form can be used. Some examples of the fibrous filler of the inorganic filler type can be those such as glass fiber, glass fiber (such as flat fiber) with non-circular cross section, carbon fiber, silica fiber, silica alumina fiber, zirconium oxide fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber and other metal fiber material (such as stainless steel, aluminum, titanium, copper and brass). Typical fibrous filler is glass fiber or carbon fiber. Alternatively, the inorganic filler can be a powdered filler, such as carbon black, graphite, silicon dioxide, quartz powder, glass beads, glass powder, calcium silicate, kaolin, talc, clay, diatomaceous earth, silicate (such as wollastonite), metal oxides (such as iron oxide, titanium oxide, zinc oxide and aluminum oxide), metal hydroxides, metal carbonates (such as calcium carbonate and magnesium carbonate), metal sulfates (such as calcium sulfate and barium sulfate), silicon carbide, silicon nitride, boron nitride and various metal powders. Another example of inorganic filler is a flaky filler, such as mica, glass flakes and various metal foils. These inorganic fillers can be used alone or in two or more combinations. In use, if necessary, it is desired that the inorganic filler is processed with a sizing agent or a surface treatment agent in advance.

[0079] When present, the amount of at least one inorganic filler in the flame retardant thermoplastic composition is generally from 1 to 50 wt%, such as from 5 to 50 wt%, from 10 to 40 wt%, or from 15 to 30 wt%, based on the total weight of the flame retardant thermoplastic composition.

[0080] The flame retardant thermoplastic composition may further comprise at least one flame retardant synergist and / or additional flame retardant (v). Exemplary flame retardant synergists and additional flame retardants are as described above. When present, the amount of at least one flame retardant synergist and / or additional flame retardant (v) is typically from 1 to 25 wt%, such as from 5 to 25 wt%, based on the total weight of the flame retardant thermoplastic composition.

[0081] The flame retardant thermoplastic composition may further comprise at least one additional stabilizer (vi). Exemplary additional stabilizers are as described above. When present, the amount of the at least one additional stabilizer is generally from 0.01 to 5 wt % based on the total weight of the flame retardant thermoplastic composition.

[0082] Other ingredients or additives (vi) may be present in the flame retardant thermoplastic composition and are typically used in an amount less than 10 weight percent, such as less than 5 weight percent, of the flame retardant thermoplastic composition, and include non-limiting examples such as antioxidants, UV stabilizers, lubricants, impact modifiers, other stabilizers or acid scavengers, heat stabilizers, plasticizers, pigments, dyes, optical brighteners, antistatic agents, anti-drip agents (such as PTFE), and other additives for enhancing resin properties.

[0083] In many embodiments, the flame retardant thermoplastic composition comprises at least one thermoplastic polymer (i) in an amount from 30 to 95 wt %, at least one phosphorus-containing flame retardant (ii) in an amount from 1 to 30 wt %, at least one epoxide (iii) in an amount from 0.01 to 2 wt %, at least one inorganic filler (iv) in an amount from 0 to 50 wt %, and at least one flame retardant synergist and / or additional flame retardant (v) in an amount from 0 to 25 wt %, all weight percentages based on the total weight of the flame retardant thermoplastic composition. In many embodiments, the flame retardant thermoplastic composition comprises at least one thermoplastic polymer (i) in an amount of from 40 to 90 wt%, at least one phosphorus-containing flame retardant (ii) in an amount of from 3 to 25 wt%, and at least one epoxide in an amount of from 0.1 to 1 wt%, at least one inorganic filler (iv) in an amount of from 0 to 50 wt%, such as from 10 to 40 wt%, at least one flame retardant synergist and / or additional flame retardant (v) in an amount of from 0 to 25 wt%, such as from 5 to 25 wt%, all weight percentages are based on the total weight of the flame retardant thermoplastic composition. In some embodiments, the composition further comprises at least one additional stabilizer (vi) in an amount of from 0 to 5 wt%, such as from 0.01 to 5 wt%, based on the total weight of the flame retardant thermoplastic composition.

[0084] The phosphorus-containing flame retardant having the empirical formula (I) can be prepared by a process referred to herein as a solvent process or by a process referred to herein as a melt state process.

[0085] Preparation of phosphorus-containing flame retardants by solvent method

[0086] The phosphorus-containing flame retardant having the empirical formula (I) can be prepared by reacting a metal or a suitable metal compound with an unsubstituted or alkyl or aryl substituted phosphonic acid. The method comprises (i) preparing a reaction mixture comprising (a) an unsubstituted or alkyl or aryl substituted phosphonic acid, (b) a solvent for the phosphonic acid, and (c) a metal or a suitable metal compound; and (ii) heating or reacting the reaction mixture at a reaction temperature of 105° C. or higher for an amount of time sufficient to produce the phosphorus-containing flame retardant. In the reaction, the metal is oxidized and can be in its corresponding cationic form represented by the formula M (+)yWherein M is a metal, (+)y represents the charge of the metal cation, and y is 2 or 3. Suitable metal compounds can be represented by the formula M p (+)y X q denoted by , where M is a metal, (+)y represents the charge of the metal cation, y is 2 or 3, X is an anion, and the values ​​of p and q provide a charge-balanced metal compound.

[0087] In another embodiment, the phosphorus-containing flame retardant can be prepared by reacting a metal or a suitable metal compound with an unsubstituted or alkyl or aryl substituted pyrophosphonic acid. The method comprises (i) preparing a reaction mixture comprising (a) unsubstituted or alkyl or aryl substituted pyrophosphonic acid, (b) a solvent for pyrophosphonic acid, and (c) a metal or a suitable metal compound as above; and (ii) heating or reacting the reaction mixture at a reaction temperature of 20°C or higher for a sufficient amount of time to produce the phosphorus-containing flame retardant.

[0088] Along with gained phosphorus-containing flame retardant product is precipitated out from reaction mixture, reaction product is typically formed into slurry.Reaction remaining phosphonic acid, pyrophosphonic acid and / or solvent can be removed together with any possible by-product by filtering and / or washing (for example with water).In many embodiments, produced substantially pure flame retardant material, for example comprise the flame retardant of the mixture of single compound or active compound substantially with flame retardant activity.The conversion rate based on metal or metallic compound is typically high, and if desired, product can be easily separated and optionally further purified.

[0089] Typically, the molar ratio of phosphonic acid or pyrophosphonic acid to metal or suitable metal compound in the reaction mixture is higher than 2: 1, such as about 3: 1 or higher, about 4: 1 or higher, about 5: 1 or higher, about 6: 1 or higher, about 7: 1 or higher, or about 8: 1 or higher. Phosphonic acid or pyrophosphonic acid with a larger molar excess relative to metal or suitable metal compound is usually used in the reaction mixture, such as about 10: 1 or higher, about 15: 1 or higher, about 20: 1 or higher, about 25: 1 or higher, about 30: 1 or higher, or any range therebetween. Phosphonic acid or pyrophosphonic acid with a large molar excess relative to metal or suitable metal compound can be used. For example, the molar ratio can be up to about 50: 1, up to about 100: 1, up to about 300: 1, up to about 500: 1, or any range therebetween. However, as will be understood, under certain large molar excess, process efficiency may be affected, for example, product precipitation from the reaction mixture may be hindered. In many embodiments, the molar ratio ranges from about 4:1, from about 5:1, from about 6:1, from about 8:1, or from about 10:1 to about 100:1, or to about 50:1, such as from about 8:1, from about 12:1, from about 16:1, or from about 20:1 to about 50:1, or to about 40:1.

[0090] The reaction mixture is heated at the reaction temperature for an amount of time sufficient to produce a flame retardant product. As used herein, the steps of "heating the reaction mixture at the reaction temperature for an amount of time sufficient to produce a phosphorus-containing flame retardant" and the like include, but are not limited to, the following embodiments: During the process of heating the reaction mixture to the reaction temperature or heating the reaction mixture at the reaction temperature, all or substantially all of the component (b) of the reaction mixture - i.e., the solvent for the phosphonic acid or pyrophosphonic acid - evaporates from the reaction mixture. Therefore, it should be understood that even if all or substantially all of the solvent component (b) evaporates during the process of heating the reaction mixture to the reaction temperature or heating the reaction mixture at the reaction temperature, the "reaction mixture" described herein is still referred to as being heated at the reaction temperature.

[0091] The reaction temperature of the phosphorus-containing flame retardant produced according to the solvent method of the present disclosure should be selected to promote the formation of pyrophosphonic acid ligands in the reaction product. For phosphonic acid, a reaction temperature of 105°C or higher is used. Without being bound by a particular theory, the reaction temperature is selected to produce pyrophosphonic acid ligands by one or more dehydration reactions. In many embodiments, metal or suitable metal compound and phosphonic acid react at the following temperature: higher than 105°C, such as about 115°C or higher, about 120°C or higher, about 130°C or higher, about 140°C or higher, about 150°C or higher, about 160°C or higher, about 170°C or higher, about 180°C or higher, about 200°C or higher, about 220°C or higher, about 240°C or higher, about 260°C or higher, about 280°C or higher or any range therebetween. The reaction temperature can be higher than those temperatures mentioned above, such as up to about 350°C, up to about 400°C or higher, but it typically does not reach or exceed the boiling temperature of phosphonic acid. In many embodiments, the reaction temperature ranges from about 110°C to about 350°C, from about 115°C to about 300°C, from about 125°C to about 280°C, or from about 140°C to about 260°C. Through one or more dehydration reactions, water is formed, which may potentially lead to undesirable reverse (hydrolysis) reactions. Therefore, in some embodiments, the reaction system is designed to promote the removal of water from the reaction mixture, such as continuous removal of water. For example, the reaction temperature can be selected to be higher than the boiling temperature of water, to achieve the necessary degree of water to evaporate at least a portion or a desired amount (e.g., most, substantially all or all) from the reaction. Additional means can be used, such as gas purge, vacuum and / or other known means to promote the removal of water from the reaction system.

[0092] For pyrophosphonic acid, a reaction temperature of 20°C or higher is used. Since dehydration is not necessary for pyrophosphonic acid, the reaction temperature can be lower than the reaction temperature of the above-mentioned phosphonic acid. In many embodiments, the metal or suitable metal compound and pyrophosphonic acid are reacted at a temperature higher than 20°C, such as about 40°C or higher, about 60°C or higher, about 80°C or higher, about 100°C or higher, about 140°C or higher, about 180°C or higher, about 200°C or higher, or any range therebetween. The reaction temperature can be higher than those temperatures described above, such as up to about 300°C, up to about 400°C, or higher, but it typically does not reach or exceed the boiling temperature of pyrophosphonic acid. In many embodiments, the reaction temperature ranges from about 25°C to about 350°C, from about 25°C to about 280°C, from about 30°C to about 260°C, from about 40°C to about 260°C, or from about 60°C to about 240°C. Depending on, for example, the metal compound used to react with pyrophosphonic acid, the reaction may generate water. As described above, in some embodiments, the reaction system is designed to facilitate the removal of water from the reaction, such as continuous removal of water. For example, the reaction temperature can be selected to be higher than the boiling temperature of water, to achieve the necessary degree of evaporating at least a portion or a desired amount (e.g., most, substantially all or all) of water from the reaction. Additional means can be used, such as gas purge, vacuum and / or other known means to facilitate the removal of water from the reaction system.

[0093] The reaction can, but need not, be carried out under reduced pressure or in vacuum.

[0094] In some embodiments of the solvent method, the solvent is a protic solvent (e.g., water), and the reaction system is designed to facilitate the removal of the protic solvent during the heating of the reaction mixture, such as the continuous removal of the protic solvent. For example, a reaction temperature equal to or higher than the boiling temperature of the protic solvent can be selected to evaporate at least a portion or the desired amount (e.g., most, substantially all, or all) of the protic solvent during the heating of the reaction mixture. In certain embodiments, the solvent is water, and the reaction temperature is about 110°C or higher, about 115°C or higher, about 120°C or higher, about 130°C or higher, about 140°C or higher, about 150°C or higher, or about 160°C or higher, such as the exemplary ranges described above. As further described herein, a reaction temperature equal to or higher than the melting temperature of phosphonic acid or pyrophosphonic acid can also be selected.

[0095] Typically, the flame retardant product will be precipitated from the reaction mixture so that the reaction is carried out to be enough to realize the time of this precipitation. Usually, based on the metal or suitable metal compound in the reaction mixture, the amount of the time required for realizing at least being converted into the flame retardant product will depend on the reaction temperature, wherein the higher the temperature usually causes the shorter the reaction time. Usually, heating or reaction occurs at the reaction temperature from about 0.1 to about 48 hours, such as from about 0.2 to about 36 hours, from about 0.5 to about 30 hours, from about 1 hour to about 24 hours, for example from about 1 hour to about 12 hours, from about 1 hour to about 8 hours or from about 1 hour to about 5 hours, although other durations can be used.

[0096] The reaction mixture can be prepared in any manner suitable for combining or mixing (a) unsubstituted or alkyl or aryl substituted phosphonic acid or pyrophosphonic acid, (b) a solvent for phosphonic acid or pyrophosphonic acid, and (c) a metal or a suitable metal compound. For example, these components can be combined simultaneously or at different times. In some embodiments, a metal or a suitable metal compound (c) is added to a mixture of phosphonic acid or pyrophosphonic acid (a) and a solvent (b), such as a solution. The metal or a suitable metal compound (c) can be added to the reaction mixture at one time or in batches. Similarly, phosphonic acid or pyrophosphonic acid (a), a solvent (b) or a mixture of phosphonic acid or pyrophosphonic acid (a) and a solvent (b), such as a solution, can be added to the reaction mixture at one time or in batches.

[0097] When preparing the reaction mixture, phosphonic acid or pyrophosphonic acid (a), solvent (b) and metal or suitable metal compound (c) can be combined at a preparation temperature lower than the reaction temperature. The reaction mixture is then heated to the reaction temperature. For example, the preparation temperature can be selected to promote the dissolution of phosphonic acid or pyrophosphonic acid (a) in solvent (b), or otherwise form a uniform liquid or solution of phosphonic acid or pyrophosphonic acid (a) and solvent (b). At the preparation temperature, and according to the metal compound (c), the reaction mixture can form a solution, a suspension or a slurry, such as a uniform or substantially uniform suspension or slurry. In some embodiments, such as at a higher preparation temperature, the reaction mixture can form a solution. Typically, when approaching or at the reaction temperature, the reaction mixture will exist as a solution. In many embodiments, the preparation temperature is about 0°C or higher, but is generally less than 150°C, such as less than 125°C, less than 115°C, less than 100°C, less than 85°C, or less than 65°C. For example, the preparation temperature can range from about 0°C to about 65°C or from about 15°C to about 40°C. In some embodiments, the reaction mixture is prepared at room temperature (e.g., from about 15° C. to about 25° C.). In some embodiments, the solvent (b) is preheated to the preparation temperature and combined with the phosphonic acid or pyrophosphonic acid (a) and the metal or suitable metal compound (c). In some embodiments, the mixture of solvent (b) and phosphonic acid or pyrophosphonic acid (a) is preheated to the preparation temperature and combined with the metal or suitable metal compound (c).

[0098] Alternatively, the reaction mixture can be prepared at the reaction temperature. That is, the reaction mixture is prepared by combining (a) phosphonic acid or pyrophosphonic acid, (b) a solvent for phosphonic acid or pyrophosphonic acid, and (c) a metal or a suitable metal compound at the reaction temperature. For example, in some embodiments, the reaction mixture is prepared by preheating a mixture of solvent (b) and phosphonic acid or pyrophosphonic acid (a) to the reaction temperature and combining with a metal or a suitable metal compound (c).

[0099] In some embodiments, wherein the reaction temperature is higher than the melting temperature of phosphonic acid or pyrophosphonic acid, and after achieving the desired conversion (e.g., complete or substantially complete conversion) to the flame retardant product, the residual phosphonic acid or pyrophosphonic acid is present in the product reaction mixture, and the product reaction mixture is cooled to a temperature higher than or not lower than the melting temperature of the residual phosphonic acid or pyrophosphonic acid to ensure that the phosphonic acid or pyrophosphonic acid remains in liquid form. This may be particularly useful in the following embodiments: wherein a perceptible amount of the solvent for phosphonic acid or pyrophosphonic acid (i.e., component (b)) evaporates due to heating, so that the remaining excess phosphonic acid or pyrophosphonic acid may have a greater tendency to come out of the solution. Excess phosphonic acid or pyrophosphonic acid and solvent (if present in the product reaction mixture) can be removed by filtering / washing, and optionally recovered. The recovered excess phosphonic acid or pyrophosphonic acid and / or solvent can be recycled, for example, returned to the reactor, in which the metal or suitable metal compound (c) reacts with the phosphonic acid or pyrophosphonic acid (a). After conversion to the reaction product, a solvent for phosphonic acid or pyrophosphonic acid (which may but need not be the same as the solvent component (b)) may be optionally added to dissolve or otherwise help remove excess phosphonic acid or pyrophosphonic acid. The phosphorus-containing flame retardant product is typically separated by filtration, optionally followed by additional processing (e.g., washing, drying, sieving, etc.). The resulting phosphorus-containing flame retardant product, which is typically in the form of a powder or small particles, is easy to process, i.e., grinding, milling, or other such physical processing is not required or necessary before use. It should be understood that the "direct" production of a phosphorus-containing flame retardant product in the form of a powder or small particles allows the reaction product to be post-processed, such as separating the flame retardant product (e.g., separating the flame retardant product from the remaining solvent), which may include, for example, treating the reaction product by filtering, sieving, washing, drying, etc.

[0100] The solvent for phosphonic acid or pyrophosphonic acid can be any solvent capable of dissolving phosphonic acid or pyrophosphonic acid components, and the solvent should be inert or substantially inert for the reaction between phosphonic acid or pyrophosphonic acid and metal or suitable metal compound, and can be further selected when considering other reaction parameters (such as preparation and / or reaction temperature or the type of metal or suitable metal compound), so as to prepare a uniform or substantially uniform reaction mixture. In certain embodiments, the solvent can be a combination of solvents for phosphonic acid or pyrophosphonic acid. Usually, phosphonic acid or pyrophosphonic acid is substantially or completely dissolved in a solvent. For example, phosphonic acid or pyrophosphonic acid and a solvent can form a solution. In certain embodiments, phosphonic acid or pyrophosphonic acid can be partially dissolved and partially suspended or dispersed in a solvent. The type of solvent, the solvent relative to the amount of phosphonic acid or pyrophosphonic acid and mixing conditions can be selected to achieve the desired dissolution level of phosphonic acid, such as obtaining a high concentration of phosphonic acid or pyrophosphonic acid in a mixture, while maintaining phosphonic acid or pyrophosphonic acid in a solution. Usually, the ratio range of acid to solvent is by weight from about 10:1 to 1:10, about 5:1 to 1:5 or about 3:1 to 1:3. In some embodiments where the acid is partially dissolved and partially suspended or dispersed in the solvent, the preparation temperature or reaction temperature may be selected to be equal to or above the melting temperature of the acid to liquefy the acid suspended or dispersed in the solvent.

[0101] As mentioned above, according to the boiling temperature of the reaction temperature and the solvent for phosphonic acid or pyrophosphonic acid, when being heated to the reaction temperature or being in the reaction temperature, at least a portion of the solvent may evaporate from the reaction mixture. In certain embodiments, all, substantially all or at least most of the solvent evaporates from the reaction mixture during heating. The solvent can be high boiling (such as sulfolane or dimethyl sulfoxide (DMSO)) or low boiling (such as chloroform or tetrahydrofuran (THF)). For example, in certain embodiments, the solvent boils at a temperature equal to or lower than the reaction temperature so that at least a portion of the solvent evaporates during the heating reaction mixture, for example, wherein all, substantially all or most of the solvent evaporates. The reaction temperature can be selected to be equal to or higher than the melting temperature of phosphonic acid or pyrophosphonic acid, to ensure that when the solvent evaporates, phosphonic acid or pyrophosphonic acid remain in liquid form. In this way, using a large amount of excessive phosphonic acid or pyrophosphonic acid in the reaction mixture can allow phosphonic acid or pyrophosphonic acid to be both the reactant of reaction and the solvent of reaction.

[0102] In still other embodiments, the solvent has a boiling temperature above the reaction temperature, ensuring that it will remain in the product reaction mixture from which the flame retardant product of the reaction can be separated as described herein. In some embodiments, the reaction temperature is selected to be below the melting temperature of the phosphonic acid or pyrophosphonic acid.

[0103] Suitable solvent can be organic or inorganic.Examples of suitable solvents for phosphonic acid or pyrophosphonic acid include but are not limited to water, sulfone, sulfoxide, halogenated (e.g. chlorinated) hydrocarbons, aromatic hydrocarbons and ethers.For example, in some embodiments, solvent can be selected from water, sulfolane, dimethyl sulfone, tetrahydrofuran (THF), dimethoxyethane (DME), 1,4-dioxane, dimethyl sulfoxide (DMSO), 1,2-dichlorobenzene, chloroform, carbon tetrachloride, dimethylbenzene and mesitylene.In certain embodiments, solvent comprises water.In certain embodiments, solvent comprises aqueous solution.In certain embodiments, reaction mixture is aqueous reaction mixture.

[0104] The solvent can be protic or aprotic. In many embodiments, the solvent for pyrophosphonic acid is an aprotic solvent.

[0105] In some embodiments, solvent (b) comprises a sulfone having the formula R1R2SO2, wherein R1 and R2 are independently selected from C 1-6 Hydrocarbon, such as C 1-3 hydrocarbon group, or R1 and R2 together with S form a ring having 2, 3, 4 or 5 carbon atoms, which ring may be unsubstituted or C 1-3 In some embodiments, R1 and R2 together with S form a di-, tri-, tetra-, or penta-methylene ring. In some embodiments, R1 and R2 are independently selected from C 1-6 In some embodiments, R1 or R2 is C 1-6 alkyl and the other is C 1-3 In some embodiments, R1 and R2 are independently selected from C 1-3 Alkyl. The alkyl group can be branched or straight. In certain embodiments, R1 and R2 are both methyl, both ethyl, or both propyl. In other embodiments, R1 or R2 is methyl and the other is ethyl or propyl. In other embodiments, R1 or R2 is ethyl and the other is propyl. In certain embodiments, the sulfone is sulfolane.

[0106] Phosphonic acid can be represented by the following formula:

[0107]

[0108] wherein R is H, alkyl, aryl, alkylaryl, or arylalkyl. In many embodiments, R is H, C 1-12 Alkyl, C 6-10 Aryl, C 7-18 Alkyl aryl, or C 7-18 Arylalkyl, wherein the alkyl, aryl, alkylaryl, or arylalkyl is unsubstituted or substituted with halogen, hydroxy, amino, C 1-4 Alkylamino, di-C 1-4 Alkylamino, C 1-4Alkoxy, carboxyl or C 2-5 In some embodiments, the alkyl, aryl, alkylaryl, or arylalkyl is unsubstituted C 1-12 Alkyl, C6 aryl, C 7-10 Alkyl aryl, or C 7-10 Arylalkyl, for example, C 1-6 Alkyl, phenyl, or C 7-9 In some embodiments, R is substituted or unsubstituted C 1-6 Alkyl, C6 aryl, C 7-10 Alkyl aryl, or C 7-12 Arylalkyl, for example, C 1-4 Alkyl, C6 aryl, C 7-9 Alkyl aryl, or C 7-10 In many embodiments, R is an unsubstituted C 1-12 Alkyl groups, such as C 1-6 In many embodiments, lower alkylphosphonic acids are used, for example, methyl-, ethyl-, propyl-, isopropyl-, butyl-, tert-butyl-, etc.

[0109] Pyrophosphonic acid can be represented by the following formula:

[0110]

[0111] wherein R is as described above.

[0112] The method for producing phosphorus-containing flame retardants can use more than one phosphonic acid, more than one pyrophosphonic acid, or a combination of phosphonic acid and pyrophosphonic acid. In certain embodiments, phosphonic acid or pyrophosphonic acid are generated in situ. For example, preparing the reaction mixture may include preparing phosphonic acid or pyrophosphonic acid, such as by hydrolyzing higher oligomer phosphonic acid and / or cyclic phosphonic anhydride starting materials.

[0113] As used herein, "suitable metal compound" or the like refers to a metal compound having the formula M p (+)y X q Compounds wherein M is a metal that forms a 2+ or 3+ cation, and X is any anion that provides a charge-balanced compound with the metal M. Suitable examples of X include, but are not limited to, anions that form oxides, halides, alkoxides, hydroxides, carbonates, carboxylates, and phosphonates with the metal M. The values ​​of p and q provide charge-balanced metal compounds, such as aluminum oxide, Al2O3. In some embodiments, as described herein, unsubstituted metal M is used. Examples of suitable metals (M) include, but are not limited to, Al, Ga, Sb, Fe, Co, B, Bi, Mg, Ca, and Zn. In some embodiments, M is selected from Al, Fe, Mg, Zn, and Ca.

[0114] Suitable metal compounds include, but are not limited to, compounds having metal-oxygen bonds, metal-nitrogen bonds, metal-halogen bonds, metal-hydrogen bonds, metal-phosphorus bonds, metal-sulfur bonds, metal-boron bonds, and the like, such as oxides, halides, alkoxides, hydroxides, carboxylates, carbonates, phosphonates, phosphinates, phosphinates, phosphates, phosphites, nitrates, nitrites, borates, hydrides, sulfonates, sulfates, sulfides, and the like of Al, Ga, Sb, Fe, Co, B, Bi, Mg, Ca, and Zn, such as oxides, hydroxides, halides, or alkoxides of Al, Fe, Mg, Zn, or Ca.

[0115] In some embodiments, the metal M of the metal or suitable metal compound is aluminum or iron. In some embodiments, suitable metal compounds are selected from halides, oxides, hydroxides, alkoxides, carbonates, carboxylates and phosphonates of aluminum. In some embodiments, suitable metal compounds are selected from halides, oxides, hydroxides and alkoxides of aluminum. In some embodiments, suitable metal compounds are selected from aluminum oxide, aluminum chloride, aluminum hydroxide, aluminum isopropoxide, aluminum carbonate and aluminum acetate. In other embodiments, suitable metal compounds are selected from halides, oxides, alkoxides, carbonates and acetates of iron. In some embodiments, suitable metal compounds are selected from iron oxide (III), iron chloride (III), iron isopropoxide (III) and iron acetate (III).

[0116] In some embodiments, the suitable metal compound is a metal phosphonate. As described herein, the metal in the metal phosphonate can be a metal M. In some embodiments, the metal phosphonate is prepared by the reaction of an initial metal compound and a phosphonic acid with a solvent (e.g., water) for the phosphonic acid. The initial metal compound can be a compound according to a suitable metal compound described herein. In some embodiments, the initial metal compound and the phosphonic acid react at room temperature or about room temperature, or react at a temperature ranging from about 0°C to about 20°C. The resulting metal phosphonate can then be used as a suitable metal compound. For example, a phosphonic acid (e.g., one or more than one alkylphosphonic acid as described above) and a solvent (e.g., water) can be stirred to form a uniform solution. The solution can be cooled, for example, from about 0°C to about 20°C, and an initial metal compound (e.g., a metal oxide, a halide, an alkoxide, or a hydroxide) is added to react with the phosphonic acid. A metal phosphonate is formed and then used as a suitable metal compound.

[0117] The preparation method can produce a mixture of phosphorus-containing flame retardant compounds, but in many embodiments, the method produces a phosphorus-containing flame retardant product that is one or primarily one compound, which has a high conversion rate based on the metal or metal compound, such as at least 70%, 80%, 85%, 90%, 95%, 98% or more conversion rate, or any range therebetween, which is in contrast to the mixture of compounds obtained by the prior art method involving thermal treatment of metal phosphonates, as disclosed in U.S. Pat. No. 9,745,449.

[0118] The reaction according to the solvent method is generally carried out as follows:

[0119]

[0120] Where M is a metal and y is 2 or 3 such that M (+)y is a metal cation, wherein (+)y represents the charge of the cation; X is one or more anionic ligands attached to the metal, and the stoichiometry of M and X (i.e., p and q) provides a charge-balanced metal compound; R is H, alkyl, aryl, alkylaryl, or arylalkyl (as described herein); a, b, and c represent the ratios of their corresponding components relative to each other in the reaction product, and satisfy the charge balance equation 2(a)+c=b(y), and c is not zero. Typically, a is 0, 1, or 2 (e.g., 0 or 1), b is from 1 to 4 (e.g., 1 or 2), and c is 1 or 2, and the compound is charge-balanced. In certain embodiments, as described herein, R is methyl, ethyl, propyl, isopropyl, or butyl, and M is Al, Fe, Zn, or Ca. In further embodiments, X is oxygen, hydroxyl, alkoxy, or halogen.

[0121] The general reaction scheme with pyrophosphonic acid can be expressed as

[0122] wherein R, M, X, p, q, y, a, b and c are as described above.

[0123] As discussed above, as with inorganic coordination compounds, the formula of the reaction product is empirical or idealized, so that the product can be a coordination polymer, a complex salt, a salt sharing certain atomic valences, etc. In many embodiments, the above reaction product represents a monomer unit (i.e., a coordination entity) of a coordination polymer, and the extended coordination polymer structure thus forms the phosphorus-containing flame retardant of the present disclosure.

[0124] In certain embodiments, y is 2 (i.e., M (+)y is a divalent cation metal), a is 0, b is 1, and c is 2. In certain embodiments, the divalent cation metal M is Mg, Ca, or Zn. In other embodiments, y is 3 (i.e., M (+)yis a trivalent cation metal), a is 1, b is 1, and c is 1. In certain embodiments, the trivalent cation metal M is selected from Al, Ga, Sb, Fe, Co, B, and Bi. In certain embodiments, the trivalent cation metal M is Al, Fe, Ga, Sb, or B. In certain embodiments, M is aluminum (i.e., the reaction product is produced using aluminum or one or more aluminum compounds (such as those described herein)) or iron (i.e., the reaction product is produced using iron or one or more iron compounds (such as those described herein)).

[0125] In one example, a phosphorus-containing flame retardant compound having the following empirical formula is produced:

[0126]

[0127] As shown herein, the absence of subscripts a, b, and c in the empirical formula indicates that the subscripts are each 1, indicating that the ratio of the dianionic pyrophosphonate ligand, the metal atom, and the monoanionic pyrophosphonate ligand is 1:1:1.

[0128] Typically, in many embodiments, the phosphorus-containing flame retardant compounds of the extended coordination polymers described herein constitute all, substantially all, or at least a majority of the phosphorus-containing flame retardant product, such as at least 75%, 85%, 90%, 95%, 98% or more, or any range therebetween, by weight of the flame retardant product.

[0129] The product reaction mixture formed by the reaction, which is usually present as a slurry, can be combined with an additional solvent, which can be a solvent identical or different from the solvent used in the reaction mixture. Additional solvents can be selected, for example, from those of the solvent components for phosphonic acid or pyrophosphonic acid described herein. Additional solvent / slurry mixtures can be stirred as required to break any lumps that may have been formed. Solid product can be separated by filtration, optionally washed and dried, to produce a product in the form of powder or small particles. In some cases, the product can be sieved to refine the particle size.

[0130] The reaction can be optionally promoted with a seeding material. For example, the use of a seeding material can reduce the time to achieve conversion to a phosphorus-containing flame retardant product, and can result in an increase in the consistency of the physical characteristics of the product. Therefore, in some embodiments, the reaction mixture further comprises a seeding material. Typically, the seeding material is added to the reaction mixture when or after being heated to the reaction temperature. In many embodiments, the seeding material is added before the flame retardant product is converted and / or precipitated. In some embodiments, the seeding material comprises a phosphorus-containing flame retardant produced according to the method described herein. The seeding material can be selected or refined to have a desired particle size.

[0131] In some embodiments of the solvent process, the suitable metal compound is alumina, and the phosphorus-containing flame retardant product is produced as follows:

[0132]

[0133] In one example, a phosphonic acid (such as C1-C 12 A reaction mixture of an alkylphosphonic acid (e.g., methyl, ethyl, propyl, isopropyl, butyl, or tert-butylphosphonic acid), a solvent for the phosphonic acid (e.g., water), and an oxide, hydroxide, halide, alkoxide, carbonate, or carboxylate of Al (e.g., aluminum oxide, aluminum chloride, aluminum hydroxide, aluminum isopropoxide, aluminum carbonate, or aluminum acetate) is heated to a reaction temperature as described herein, such as about 115° C. or higher, about 125° C. or higher, about 150° C. or higher, or about 165° C. or higher. Typically, a slurry is formed as the reaction proceeds, and the solid phosphorus-containing flame retardant product can be separated by filtration to produce a product in the form of a powder or small particles. Prior to separating the solid product, the product reaction mixture can be subjected to additional post-treatment, such as cooling the product reaction mixture to a temperature above or not below the melting point of the excess phosphonic acid and combining with an additional solvent (e.g., water) as described herein. As described above, the additional solvent / slurry mixture can be optionally stirred. The solid phosphorus-containing flame retardant product can be isolated by filtration, optionally washed with additional solvent and dried to produce a product in the form of a powder or small particles. The flame retardant product contains phosphorus and aluminum in a 4:1 ratio of phosphorus to aluminum according to the following empirical formula:

[0134] In another example, the examples described directly above are carried out with iron or a suitable iron compound, such as an iron halide, oxide, alkoxide, carbonate or acetate, for example iron (III) oxide, iron (III) chloride, iron (III) isopropoxide or iron (III) acetate. The flame retardant product contains phosphorus and iron in a 4:1 ratio according to the following empirical formula:

[0135]

[0136] Typically, the compound having the above empirical formula (which in many embodiments is an extended coordination polymer described herein) constitutes all, substantially all, or at least a majority of the phosphorus-containing flame retardant product, such as at least 75%, 85%, 90%, 95%, 98% or more, or any range therebetween, by weight of the flame retardant product.

[0137] In a further embodiment, the suitable metal compound is a metal phosphonate having the formula:

[0138]

[0139] Where R and M are as described above, p is 2 or 3, and y is 2 or 3, such that M (+)yis a metal cation, wherein (+)y represents the charge formally assigned to the cation, and the metal phosphonate is charge balanced (ie, p=y). The metal phosphonates can be prepared according to methods known in the art.

[0140] In one example, a phosphonic acid such as an alkylphosphonic acid (e.g., methyl, ethyl, propyl, isopropyl, butyl, or tert-butylphosphonic acid) is combined with water (e.g., about 1:1 by weight), and stirred and cooled to below room temperature (e.g., cooled to or below 10° C., such as about 0° C.). An initial metal compound is added to the mixture of phosphonic acid and water to form a metal phosphonate. The metal phosphonate is then used as a suitable metal compound to produce a phosphorus-containing flame retardant product in the form of a powder or small particles. In embodiments involving aluminum phosphonate as a suitable metal compound, the flame retardant product contains phosphorus and aluminum in a 4:1 ratio of phosphorus to aluminum according to the following empirical formula:

[0141] The compound having the empirical formula, which in many embodiments is an extended coordination polymer as described herein, typically constitutes all, substantially all, or at least a majority of the flame retardant product, such as at least 75%, 85%, 90%, 95%, 98% or more, or any range therebetween, by weight of the flame retardant product.

[0142] Preparation of phosphorus-containing flame retardants by molten state method

[0143] The phosphorus-containing flame retardant having the empirical formula (I) can be prepared by reacting a metal or a suitable metal compound with a stoichiometric excess of an unsubstituted or alkyl or aryl substituted phosphonic acid. The reaction temperature is 105°C or higher, the phosphonic acid is molten at the reaction temperature, and the molar ratio of the phosphonic acid to the metal or suitable metal compound in the reaction mixture is higher than 4:1. In the reaction, the metal is oxidized and can be converted into a phosphonic acid in its corresponding cationic form by the formula M (+)y Wherein M is a metal, (+)y represents the charge of the metal cation, and y is 2 or 3. Suitable metal compounds can be represented by the formula M p (+)y X q denoted by , where M is a metal, (+)y represents the charge of the metal cation, y is 2 or 3, X is an anion, and the values ​​of p and q provide a charge-balanced metal compound.

[0144] In another embodiment, the phosphorus-containing flame retardant having the empirical formula (I) can be prepared by reacting a metal or a suitable metal compound with a stoichiometric excess of unsubstituted or alkyl or aryl substituted pyrophosphonic acid, wherein the pyrophosphonic acid is molten at the reaction temperature and the molar ratio of the pyrophosphonic acid to the metal or the suitable metal compound in the reaction mixture is greater than 2:1.

[0145] As used herein, a "stoichiometric excess" of unsubstituted or alkyl or aryl substituted phosphonic acid or pyrophosphonic acid relative to a metal or suitable metal compound means that the amount of phosphonic acid or pyrophosphonic acid exceeds the stoichiometric amount required for the reaction between the metal or suitable metal compound and the phosphonic acid or pyrophosphonic acid. As described herein, the stoichiometric excess is typically represented by the molar ratio of phosphonic acid or pyrophosphonic acid to metal or suitable metal compound in the reaction mixture.

[0146] As described herein, the unsubstituted or alkyl or aryl substituted phosphonic acid or pyrophosphonic acid used in stoichiometric excess serves as reagent and solvent for reaction. As the resulting phosphorus-containing flame retardant product is precipitated from the reaction mixture, the reaction product is typically formed into a slurry. The excess phosphonic acid or pyrophosphonic acid remaining after the reaction can be removed together with any possible by-product by filtering and / or washing (e.g., with water). In many embodiments, substantially pure flame retardant materials are produced, such as flame retardants comprising a single compound or a mixture of substantially active compounds that are substantially flame retardant active. The conversion rate based on metal or metallic compound is typically high, and if desired, the product can be easily separated and optionally further purified.

[0147] Typically, the mol ratio of phosphonic acid to metal or suitable metal compound in the reaction mixture is 5: 1 or higher, such as about 6: 1 or higher, about 8: 1 or higher or about 10: 1 or higher. In the reaction mixture, the phosphonic acid with a larger molar excess relative to the metal or suitable metal compound can be used, such as about 12: 1 or higher, about 15: 1 or higher, about 20: 1 or higher, about 25: 1 or higher, about 30: 1 or higher or any scope therebetween. With respect to metal or suitable metal compound, the phosphonic acid with a large molar excess can be used. For example, the mol ratio can be up to about 50: 1, up to about 100: 1, up to about 300: 1, up to about 500: 1 or any scope therebetween. However, as will be understood, under certain large molar excess, process efficiency may be affected, for example, product precipitation from the reaction mixture may be hindered. In many embodiments, the molar ratio ranges from about 8:1, from about 10:1, from about 12:1, or from about 16:1 to about 100:1 or to about 50:1, such as from about 10:1, from about 15:1, from about 20:1 to about 50:1 or to about 40:1.

[0148] Typically, for pyrophosphonic acid, the molar ratio of pyrophosphonic acid to metal or suitable metal compound in the reaction mixture is 3: 1 or higher, such as about 4: 1 or higher, about 6: 1 or higher, or about 8: 1 or higher. Conventionally, a pyrophosphonic acid with a molar excess relative to the metal or suitable metal compound is used in the reaction mixture, such as about 10: 1 or higher, about 12: 1 or higher, about 15: 1 or higher, about 18: 1 or higher, about 20: 1 or higher, or any range therebetween. With respect to the metal or suitable metal compound, a large molar excess of pyrophosphonic acid can be used. For example, the molar ratio can be up to about 30: 1, up to about 50: 1, up to about 100: 1, up to about 250: 1, or any range therebetween. However, as will be appreciated, at a certain large molar excess, process efficiency may be affected, for example, product precipitation from the reaction mixture may be hindered. In many embodiments, the molar ratio ranges from about 4:1, from about 5:1, from about 6:1, or from about 8:1 to about 50:1 or to about 25:1, such as from about 5:1, from about 8:1, from about 10:1 to about 25:1 or to about 20:1.

[0149] The reaction temperature for producing phosphorus-containing flame retardants according to the molten state method should be selected so that the phosphonic acid or pyrophosphonic acid is in a molten state at the reaction temperature. For example, phosphonic acid and pyrophosphonic acid (e.g., alkyl-substituted phosphonic acid or pyrophosphonic acid) are generally solid at room temperature (e.g., methylphosphonic acid melts at about 105° C., and ethylphosphonic acid melts at about 62° C.), and therefore heating the phosphonic acid or pyrophosphonic acid to produce a liquefied physical state (i.e., a molten state) is generally suitable for forming a consistent reaction mixture. As will be appreciated by those skilled in the art, the desired reaction temperature at which the phosphonic acid or pyrophosphonic acid is in a molten state may vary depending on the selected reagents and thermodynamic conditions.

[0150] The reaction temperature should also be selected to promote the formation of pyrophosphonic acid ligands in the reaction product. For phosphonic acid, a reaction temperature of 105°C or higher is used. Without being bound by a particular theory, the reaction temperature is selected to produce pyrophosphonic acid ligands by one or more dehydration reactions. In many embodiments, metal or suitable metal compound and phosphonic acid react at the following temperature: higher than 105°C, such as about 115°C or higher, about 120°C or higher, about 130°C or higher, about 140°C or higher, about 150°C or higher, about 160°C or higher, about 170°C or higher, about 180°C or higher, about 200°C or higher, about 220°C or higher, about 240°C or higher, about 260°C or higher, about 280°C or higher or any range therebetween. The reaction temperature can be higher than those temperatures mentioned above, such as up to about 350°C, up to about 400°C or higher, but it typically does not reach or exceed the boiling temperature of phosphonic acid. For example, the reaction temperature can range from about 150°C to about 300°C, such as from about 150°C to about 280°C, from about 160°C to about 260°C, or from about 160°C to about 240°C. In many embodiments, the reaction temperature ranges from about 110°C to about 350°C, from about 115°C to about 300°C, from about 125°C to about 280°C, or from about 140°C to about 260°C. Through one or more dehydration reactions, water is formed, which may potentially lead to undesirable reverse (hydrolysis) reactions. Therefore, in some embodiments, the reaction system is designed to facilitate the removal of water from the reaction, such as continuous removal of water. For example, the reaction temperature can be selected to be higher than the boiling temperature of water, to achieve the necessary degree of evaporating at least a portion or the desired amount (e.g., most, substantially all or all) of water from the reaction. Additional means can be used, such as gas purging, vacuum and / or other known means to facilitate the removal of water from the reaction system.

[0151] Since dehydration is unnecessary for pyrophosphonic acid, the reaction temperature of pyrophosphonic acid can be lower than the reaction temperature of the above-mentioned phosphonic acid. Generally, when using pyrophosphonic acid, the limiting criterion for selecting a suitable reaction temperature is to require that the pyrophosphonic acid is in a molten state at the reaction temperature. Generally, the metal or suitable metal compound and pyrophosphonic acid react at a temperature of 20°C or higher. In many embodiments, the metal or suitable metal compound and pyrophosphonic acid react at a temperature of higher than 20°C, such as about 40°C or higher, about 60°C or higher, about 80°C or higher, about 100°C or higher, about 140°C or higher, about 180°C or higher, about 200°C or higher, or any range therebetween. The reaction temperature can be higher than those temperatures mentioned above, such as up to about 300°C, up to about 400°C, or higher, but it typically does not reach or exceed the boiling temperature of pyrophosphonic acid. In many embodiments, the reaction temperature ranges from about 25°C to about 350°C, from about 25°C to about 280°C, from about 30°C to about 260°C, from about 40°C to about 260°C, from about 60°C to about 260°C, from about 80°C to about 240°C, from about 100°C to about 240°C, from about 110°C to about 240°C, or from about 120°C to about 240°C. Depending on, for example, the metal compound used to react with pyrophosphonic acid, the reaction may generate water. As described above, in some embodiments, the reaction system is designed to facilitate the removal of water from the reaction, such as continuous removal of water. For example, the reaction temperature can be selected to be higher than the boiling temperature of water to achieve the degree necessary to evaporate at least a portion or a desired amount (e.g., most, substantially all, or all) of water from the reaction. Additional means, such as gas purging, vacuum, and / or other known means can be used to facilitate the removal of water from the reaction system.

[0152] The reaction can, but need not, be carried out under reduced pressure or in vacuum.

[0153] Typically, as the reaction is carried out, as the gained phosphorus-containing flame retardant product is precipitated from the product reaction mixture, the product is formed into a slurry. Therefore, the reaction is typically carried out to be enough to realize the time of this precipitation. Usually, based on metal or suitable metal compound, the amount of the time required for realizing at least being converted into the flame retardant product substantially will depend on the reaction temperature, wherein the higher the temperature usually causes the shorter the reaction time. In many embodiments, metal or suitable metal compound and phosphonic acid or pyrophosphonic acid are heated at the reaction temperature from about 0.1 to about 48 hours, such as from about 0.2 to about 36 hours, from about 0.5 to about 30 hours, from about 1 hour to about 24 hours, for example from about 1 hour to about 12 hours, from about 1 hour to about 8 hours or from about 2 hours to about 5 hours, although other durations can be used.

[0154] The metal or suitable metal compound and the phosphonic acid or pyrophosphonic acid in molar excess can be combined in any manner suitable for forming a reaction mixture. For example, phosphonic acid or pyrophosphonic acid and metal or metal compound can be mixed (e.g., stirred) together to form a uniform reaction mixture. In certain embodiments, metal or suitable metal compound is added to phosphonic acid or pyrophosphonic acid preheated to the reaction temperature. In certain embodiments, phosphonic acid or pyrophosphonic acid is preheated and stirred when molten, such as under a nitrogen atmosphere or reduced pressure / vacuum. In a further embodiment, metal or metal compound is added as quickly as possible without causing a large change in the reaction temperature due to the exothermic nature of the reaction. In certain embodiments, phosphonic acid or pyrophosphonic acid and metal or suitable metal compound are combined without preheating phosphonic acid or insufficiently heating to liquefy phosphonic acid or pyrophosphonic acid, and then the components are heated to the reaction temperature. The total amount of metal or suitable metal compound or phosphonic acid or pyrophosphonic acid can be added to the reaction in a disposable or batch manner. No additional solvent is required because the phosphonic acid or pyrophosphonic acid used in molar excess serves as a reagent and solvent, but additional solvents can be used if necessary. In some embodiments, when a molar ratio of phosphonic acid or pyrophosphonic acid to metal or suitable metal compound is used that is at or near the lower limit of the molar ratios disclosed herein, additional solvent is used.

[0155] In some embodiments, after achieving the desired conversion (e.g., complete or substantially complete conversion) to the flame retardant product, the product reaction mixture is cooled to a temperature higher than or not lower than the melting temperature of the excess phosphonic acid or pyrophosphonic acid, to keep the excess phosphonic acid or pyrophosphonic acid in a liquefied state. Excess phosphonic acid or pyrophosphonic acid can be removed by filtering / washing, and optionally recovered. The recovered excess phosphonic acid or pyrophosphonic acid can be recycled, for example, returned to the reactor, in which the metal or suitable metal compound reacts with the phosphonic acid or pyrophosphonic acid. After being converted into the reaction product, a solvent (e.g., water, alcohol and / or another suitable (e.g., polar) liquid) can be optionally added to dissolve or otherwise help remove excess phosphonic acid or pyrophosphonic acid. The phosphorus-containing flame retardant product is usually separated by filtration, and optionally subsequently subjected to additional treatment (e.g., washing, drying, screening, etc.). The phosphorus-containing flame retardant product obtained, which is usually in the form of a powder or small particles, is easy to process, i.e., it is not necessary or unnecessary to grind, grind or other such physical processing before use. It should be understood that "directly" producing a flame retardant material in powder or small particles allows the reaction product to be post-processed, such as separating the flame retardant product (e.g., separating the flame retardant product from excess phosphonic acid or pyrophosphonic acid or remaining solvent), which can include, for example, filtering, screening, washing, drying, etc., to process the reaction product. After the reaction, the resulting product reaction mixture (usually a slurry) can be cooled to or just above the melting temperature of the excess phosphonic acid, and the slurry is combined with water. The water / slurry mixture can be stirred as needed to break up any large lumps that may have been formed. The solid product can be separated by filtration, optionally washed with water and dried to produce a product in the form of a powder or small particles. In some cases, the product can be sieved to refine the particle size.

[0156] The phosphonic acid or pyrophosphonic acid used to produce the phosphorus-containing flame retardant can be a phosphonic acid or pyrophosphonic acid as described above. The method can use more than one phosphonic acid, more than one pyrophosphonic acid, or a combination of phosphonic acid and pyrophosphonic acid. In certain embodiments, phosphonic acid or pyrophosphonic acid is generated in situ. For example, preparing the reaction mixture can include preparing phosphonic acid or pyrophosphonic acid, such as by hydrolyzing higher oligomer phosphonic acid and / or cyclic phosphonic anhydride starting materials.

[0157] Suitable metals and metal compounds for the reaction are described above.

[0158] The preparation method can produce a mixture of phosphorus-containing flame retardant compounds, but in many embodiments, the method produces a phosphorus-containing flame retardant product that is one or primarily one compound, which has a high conversion rate based on the metal or metal compound, such as at least 70%, 80%, 85%, 90%, 95%, 98% or more conversion rate, or any range therebetween, which is in contrast to the mixture of compounds obtained by the prior art method involving thermal treatment of metal phosphonates, as disclosed in U.S. Pat. No. 9,745,449.

[0159] The reaction according to the molten state method is generally carried out as follows:

[0160]

[0161] Where M is a metal and y is 2 or 3 such that M (+)y is a metal cation, wherein (+)y represents the charge of the cation; X is one or more anionic ligands attached to the metal, and the stoichiometry of M and X (i.e., p and q) provides a charge-balanced metal compound; R is H, alkyl, aryl, alkylaryl, or arylalkyl (as described herein); a, b, and c represent the ratios of their corresponding components relative to each other in the reaction product, and satisfy the charge balance equation 2(a)+c=b(y), and c is not zero. Typically, a is 0, 1, or 2 (e.g., 0 or 1), b is from 1 to 4 (e.g., 1 or 2), and c is 1 or 2, and the compound is charge-balanced. In certain embodiments, as described herein, R is methyl, ethyl, propyl, isopropyl, or butyl, and M is Al, Fe, Zn, or Ca. In further embodiments, X is oxygen, hydroxyl, alkoxy, or halogen.

[0162] The general reaction scheme with pyrophosphonic acid can be expressed as

[0163] wherein R, M, X, p, q, y, a, b and c are as described above.

[0164] As discussed above, as with inorganic coordination compounds, the formula of the reaction product is empirical or idealized, so that the product can be a coordination polymer, a complex salt, a salt sharing certain atomic valences, etc. In many embodiments, the above reaction product represents a monomer unit (i.e., a coordination entity) of a coordination polymer, and the extended coordination polymer structure thus forms the phosphorus-containing flame retardant of the present disclosure.

[0165] In certain embodiments, y is 2 (i.e., M (+)y is a divalent cation metal), a is 0, b is 1, and c is 2. In certain embodiments, the divalent cation metal M is Mg, Ca, or Zn. In other embodiments, y is 3 (i.e., M (+)y is a trivalent cation metal), a is 1, b is 1, and c is 1. In certain embodiments, the trivalent cation metal M is selected from Al, Ga, Sb, Fe, Co, B, and Bi. In certain embodiments, the trivalent cation metal M is Al, Fe, Ga, Sb, or B. In certain embodiments, M is aluminum (i.e., the reaction product is produced using aluminum or one or more aluminum compounds (such as those described herein)) or iron (i.e., the reaction product is produced using iron or one or more iron compounds (such as those described herein)).

[0166] In one example, a phosphorus-containing flame retardant compound having the following empirical formula is produced:

[0167]

[0168] As described above, the absence of subscripts a, b, and c in the empirical formula indicates that the subscripts are each 1, indicating that the ratio of the dianionic pyrophosphonic acid ligand, the metal atom, and the monoanionic pyrophosphonic acid ligand is 1:1:1.

[0169] Typically, in many embodiments, the phosphorus-containing flame retardant compounds of the extended coordination polymers described herein constitute all, substantially all, or at least a majority of the phosphorus-containing flame retardant product, such as at least 75%, 85%, 90%, 95%, 98% or more, or any range therebetween, by weight of the flame retardant product.

[0170] The product reaction mixture formed by the reaction, which is usually present as a slurry, can be combined with a liquid (e.g., water) and stirred as needed to break up any lumps that may have formed. The solid product can be separated by filtration, optionally washed and dried to produce a product in the form of a powder or small particles. In some cases, the product can be sieved to refine the particle size.

[0171] The reaction may be optionally promoted with a seeding material. For example, the use of a seeding material may reduce the time required to achieve conversion to a phosphorus-containing flame retardant product, and may result in an increase in the consistency of the physical characteristics of the product. Therefore, in some embodiments, the reaction mixture further comprises a seeding material. Typically, the seeding material is added to the reaction mixture when or after being heated to the reaction temperature. In some embodiments, the seeding material comprises a phosphorus-containing flame retardant produced according to the method described herein. The seeding material may be selected or refined to have a desired particle size.

[0172] In some embodiments of the molten state process, the suitable metal compound is alumina, and the flame retardant material is produced as follows:

[0173]

[0174] In one example, after melting, a phosphonic acid (such as C1-C 12Alkylphosphonic acid (e.g., methyl, ethyl, propyl, isopropyl, butyl or tert-butylphosphonic acid)) is heated to or above its melting point of 105°C, such as to 115°C, 125°C, 140°C, 150°C, 160°C, 180°C, 200°C, 220°C or 240°C or higher. An oxide, hydroxide, halide, alkoxide, carbonate or carboxylate of Al (such as aluminum oxide, aluminum chloride, aluminum hydroxide, aluminum isopropoxide, aluminum carbonate or aluminum acetate) is added in a stoichiometric excess of the phosphonic acid under stirring, such as in a molar ratio of the phosphonic acid and the metal compound as described herein, such as 5:1 or higher, 10:1 or higher, or 15:1 or higher. Typically, a slurry is formed as the reaction proceeds, and the solid flame retardant product can be separated, such as by filtering, washing, etc., to produce a product in the form of a powder or small particles. Before separating the solid product, the product reaction mixture may be subjected to additional post-treatment, such as cooling the product reaction mixture to a melting point above or not below the excess phosphonic acid, and combining with a liquid (e.g., water), and optionally stirring as described above. The solid flame retardant product may be separated by filtration, optionally washed with additional solvent and dried to produce a product in the form of a powder or small particles. According to the following empirical formula, the flame retardant product contains phosphorus and aluminum in a ratio of 4:1:

[0175] In another example, the examples described directly above are carried out with iron or a suitable iron compound, such as an iron halide, oxide, alkoxide, carbonate or acetate, for example iron (III) oxide, iron (III) chloride, iron (III) isopropoxide or iron (III) acetate. The flame retardant product contains phosphorus and iron in a 4:1 ratio according to the following empirical formula:

[0176]

[0177] Typically, the compound having the above empirical formula (which in many embodiments is an extended coordination polymer described herein) constitutes all, substantially all, or at least a majority of the phosphorus-containing flame retardant product, such as at least 75%, 85%, 90%, 95%, 98% or more, or any range therebetween, by weight of the flame retardant product.

[0178] In other examples where the suitable metal compound is a metal phosphonate, the metal phosphonate is prepared by mixing a phosphonic acid (such as an alkylphosphonic acid, such as methyl, ethyl, propyl, isopropyl, butyl or tert-butylphosphonic acid) and a solvent (such as water) to form a uniform solution. For example, any convenient ratio of water to phosphonic acid can be used, such as 10:1 to 1:10 by weight, such as 5:1 to 1:5 or 2:1 to 1:2 by weight. The solution can be cooled to, for example, in the range of from about 0°C to about 20°C, and an initial metal compound (such as a metal oxide, halide, alkoxide or hydroxide) is added to react with the phosphonic acid. A metal phosphonate is formed and then used as a suitable metal compound. For example, a molar excess of phosphonic acid as described herein (such as phosphonic acid relative to the molar ratio of metal phosphonate is 5:1) is preheated to a molten state and reacted with a metal phosphonate to form a phosphorus-containing flame retardant product. In embodiments involving aluminum phosphonate salts as suitable metal compounds, the flame retardant product contains phosphorus and aluminum in a 4:1 ratio of phosphorus to aluminum according to the following empirical formula:

[0179] The compound having the empirical formula, which in many embodiments is an extended coordination polymer as described herein, typically constitutes all, substantially all, or at least a majority of the flame retardant product, such as at least 75%, 85%, 90%, 95%, 98% or more, or any range therebetween, by weight of the flame retardant product.

[0180] Preparation of flame retardant and stabilizer additive compositions

[0181] The present invention is not limited by any particular method of mixing components (A), (B), (C) and (D) of the flame retardant and stabilizer additive composition disclosed herein. For example, at least one phosphorus-containing flame retardant (A) and at least one epoxide (B), optionally with at least one flame retardant synergist and / or additional flame retardant (C) and / or one or more other stabilizers (D) can be mixed / blended by conventional mixing techniques, such as tumbling mixing, convection mixing, fluidized bed mixing, high shear mixing, etc. Conventional processing agents, such as dispersants, antistatic agents, adhesives, coupling agents, etc., can also be used.

[0182] Preparation of flame retardant thermoplastic compositions

[0183] The present invention is not limited by any particular method of blending the components of the flame retardant thermoplastic composition disclosed herein. Suitable compounding and blending techniques known in the art can be used. For example, one method includes blending thermoplastic polymers and additives in powder or granular form, and melt mixing the blend (for example, using a twin-screw extruder). Thermoplastic polymers, flame retardants, stabilizers and other additives are typically pre-dried before melt mixing. The extruded blend can be crushed into granular pellets or other suitable shapes by standard techniques. Other melt mixing process equipment such as kneader mixers or bowl mixers can be used to mix flame retardant additives and any additional ingredients with thermoplastic polymers. In either case, generally suitable machine temperatures can range from about 200°C to 330°C, depending on the specific type of thermoplastic selected.

[0184] The flame retardant thermoplastic composition can be molded in any equipment suitable for this purpose, such as in an injection molding machine. After granulation, the granular pellets are typically dried again before molding in an injection molding machine suitable for this purpose. Typically, the processing temperature ranges from about 200°C to 280°C, depending on the molding characteristics of the specific thermoplastic polymer, the loading level of additives and / or reinforcing fillers, and other factors (like the thickness of the mold cavity and the gate size). Those skilled in the art will be able to make appropriate adjustments during the molding process to accommodate differences in the composition or tooling.

[0185] Additional non-limiting disclosures are provided in the following examples.

[0186] Examples

[0187] Example 1

[0188] Methylphosphonic acid (MPA) (3678.8 g, 38.3 mol, 30 equivalents, 75% aqueous solution) and alumina (130.2 g, 1.28 mol, 1 equivalent) were mixed at room temperature, where limited exotherm (increase of about 2 ° C) was observed. The tank temperature was set to 165 ° C, with the agitator at 200 RPM at atmospheric pressure, nitrogen purging (4 L / min). When no distilled water was observed at the condenser, 1.0 g of seeding material was optionally added, which was a flame retardant product produced by MPA and alumina as described herein. The reaction mixture was heated at 165 ° C for 3 hours. The product reaction mixture containing the white slurry product was then cooled to about 130 ° C and poured into 1.5 L of water in a beaker cooled in an ice water bath. The white slurry was then filtered out, washed with water (500 mL × 3), and dried to produce fine crystals with a yield of 92%. According to the following empirical formula, the product has a phosphorus-aluminum ratio of 4: 1 (ICP elemental analysis):

[0189]

[0190] The above product empirical formula represents the repeating monomer units (i.e., coordination entities) of the coordination polymer that form the pure crystalline product. Thermogravimetric analysis (TGA) of the product is shown in Figure 1 middle.

[0191] Example 2

[0192] 800mL of xylene was loaded into a 1L flask and a Dean-Stark water trap was provided. The solution was heated to 115°C and methylphosphonic acid (MPA) (33.89g, 0.35mol) was added. The acid was dissolved and the temperature was raised so that the solution began to reflux. Alumina (4.01g, 0.039mol) was added in batches within 3 hours. Reflux was maintained at 142°C overnight. The solid product obtained was separated by filtration, washed with DMF (100mL) and Et2O (2×50mL), and dried to produce a fine powder (18.86g, 71% yield). According to the following empirical formula, the product has a phosphorus-aluminum ratio of 4:1:

[0193]

[0194] The above product empirical formula represents the repeating monomer units (ie, coordination entities) of the coordination polymer that form the pure crystalline product.

[0195] Example 3

[0196] Methylphosphonic acid (MPA) (2216g, 23.1mol, 15 equivalents, aqueous solution) and aluminum trihydroxide (120g, 1.5mol, 1 equivalent) were mixed at room temperature. The tank temperature was set to 165°C, with the agitator at 200RPM, nitrogen purging (4L / min) at atmospheric pressure. When no distilled water was observed at the condenser, 1.0g of seeding material was optionally added, which was a flame retardant product produced by MPA and aluminum trihydroxide as described herein. The reaction mixture was heated at 165°C for 3 hours. The product reaction mixture containing the white slurry product was then cooled to about 130°C and poured into 1.5L of water in a beaker cooled in an ice-water bath. The white slurry was filtered out, washed with water (500mL×3), and dried to produce fine crystals in about 100% yield. According to the following empirical formula, the product has a phosphorus-aluminum ratio of 4:1 (ICP elemental analysis):

[0197]

[0198] The above product empirical formula represents the repeating monomer units (ie, coordination entities) of the coordination polymer that form the pure crystalline product.

[0199] Example 4

[0200]

[0201] Methylphosphonic acid (MPA) (1412.6g, 14.7mol, 30 equivalents, 75% aqueous solution) and iron oxide (78.2g, 0.49mol, 1 equivalent) were mixed at room temperature. The tank temperature was set to 130°C for about 12 hours, with agitator at 250RPM, nitrogen purge (4L / min) at atmospheric pressure. The reaction mixture was subsequently heated to 165°C for 12 hours. The product reaction mixture containing the off-white slurry product was then cooled to about 130°C and poured into 1.5L of water in a beaker cooled in an ice-water bath. The off-white slurry was filtered out, washed with water (500mL×3), and dried to produce fine off-white crystals of 92% yield. According to the following empirical formula, the product has a phosphorus-iron ratio (ICP elemental analysis) of 4:1:

[0202]

[0203] The above product empirical formula represents the repeating monomer units (ie, coordination entities) of the coordination polymer that form the pure crystalline product.

[0204] Example 5

[0205]

[0206] Methylphosphonic acid (MPA) (1727 g, 18.4 mol, 15 equivalents, 75% aqueous solution) was cooled to 5 ° C in an ice-water bath under a nitrogen stream (1 L / min). Aluminum isopropoxide (250 g, 1.2 mol, 1 equivalent) was added in batches while maintaining the pot temperature below 10 ° C. The pot temperature was then set to 165 ° C, with the agitator at 250 RPM. At 165 ° C, 4.5 g of seeding material, which is a flame retardant product produced by MPA and aluminum isopropoxide as described herein, was optionally added, and the reaction mixture was maintained at 165 ° C for 3 hours. The product reaction mixture containing the white slurry product was then cooled to about 130 ° C and poured into 1.5 L of water in a beaker cooled in an ice-water bath. The white slurry was filtered out, washed with water (500 mL × 3), and dried to produce fine crystals with a yield of 44%. According to the following empirical formula, the product has a phosphorus to aluminum ratio of 4:1 (ICP elemental analysis):

[0207]

[0208] The above product empirical formula represents the repeating monomer units (ie, coordination entities) of the coordination polymer that form the pure crystalline product.

[0209] Example 6

[0210]

[0211] Ethylphosphonic acid (EPA) (55.0g, 0.50mol, 30 equivalents) and alumina (1.70g, 17mmol, 1 equivalent) were mixed with 50mL of water at room temperature. The tank temperature was set to 165°C, with agitator at atmospheric pressure at 250RPM, nitrogen purge (4L / min). The reaction mixture was heated at 165°C for 3 hours. The product reaction mixture containing the white slurry product was then cooled to about 130°C and poured into 100mL of water in a beaker cooled in an ice-water bath. The white slurry was filtered out, washed with water (50mL×3), and dried to produce fine crystals in a 76% yield. According to the following empirical formula, the product has a phosphorus-aluminum ratio (ICP elemental analysis) of 4:1:

[0212]

[0213] The above product empirical formula represents the repeating monomer units (ie, coordination entities) of the coordination polymer that form the pure crystalline product.

[0214] Example 7

[0215]

[0216] 114.6g of methylphosphonic acid was charged into a 250mL three-necked flask and then heated. The methylphosphonic acid melted at 105°C and vigorous stirring was started under N2 cover. The methylphosphonic acid was heated to 240°C and 7.78g of alumina was added as quickly as possible without causing a large amount of heat release. The slurry was cooled until it was just above the melting point of the excess methylphosphonic acid (about 110°C) and then added to 250mL of H2O while ensuring that the rate of addition did not result in excessive steam formation. The resulting mixture was stirred to break up any large lumps that may have formed, the product was separated by filtration, washed with an additional 750mL of H2O, and dried to produce 45.08g of product in the form of fine colorless crystals in 87% yield. The above product empirical formula represents the repeating monomer units (i.e., coordination entities) of the coordination polymer that forms the pure crystalline product. Thermogravimetric analysis (TGA) of the product is shown in Figure 2 middle.

[0217] Example 8

[0218]

[0219] 149.8g of ethylphosphonic acid was charged into a 250mL three-necked flask and heated to melt (62°C). Vigorous stirring was started under N2 cover, ethylphosphonic acid was heated to 240°C, and 6.9g of alumina was added as quickly as possible without causing a large amount of heat release. The slurry was cooled to about 80°C and then added to 250mL of H2O while ensuring that the rate of addition did not result in excessive steam formation. The resulting mixture was stirred to break up any large lumps that may have formed, the product was separated by filtration, washed with an additional 750mL of H2O, and dried to produce 49.07g of product in the form of fine colorless crystals in 84% yield. The above product empirical formula represents the repeating monomer units (i.e. coordination entities) of the coordination polymer forming the pure crystalline product.

[0220] Example 9

[0221]

[0222] 83 g of methylphosphonic acid was charged to the resin kettle and heated to 120 ° C. An intermediate material prepared from 50 g of methylphosphonic acid and 35.4 g of tri(isopropoxy)aluminum in the presence of water was added to the resin kettle as a slurry. The resulting solution contained a methylphosphonic acid intermediate having a molar ratio of 5:1 of methylphosphonic acid:aluminum, which was heated to 240 ° C under mechanical stirring. After the solid had formed, stirring was continued at 240 ° C for about 30 min. 500 mL of H2O was added, and the mixture was stirred for 16 h while making a uniform slurry. As described above, the product was separated by filtration, washed with an additional 750 mL of H2O, and dried to produce a product of 64.3 g of fine colorless crystals in a yield of 93%. The above product empirical formula represents the repeating monomer units (i.e., coordination entities) of the coordination polymer that forms the pure crystalline product.

[0223] Example 10

[0224]

[0225] 1305g of methylphosphonic acid was charged into a 1L three-necked flask and then heated. The methylphosphonic acid melted at 105°C and vigorous stirring was started under vacuum. The methylphosphonic acid was heated to 180°C and 61g of alumina was added as quickly as possible without causing a large amount of heat release or excessive foaming. The slurry was cooled until it was just above the melting point (about 110°C) of the excess methylphosphonic acid and then added to 1L of H2O while ensuring that the rate of addition did not result in excessive steam formation. The resulting mixture was stirred to break up any large lumps that may have formed, and the product was separated by filtration, washed with an additional 1.5L of H2O, and dried to produce 408g of a product in the form of fine colorless crystals in an 84% yield. The above product empirical formula represents the repeating monomer units (i.e., coordination entities) of the coordination polymer forming the pure crystalline product.

[0226] The product from each of Examples 7-10 had a P / Al ratio of 4:1 (ICP elemental analysis).

[0227] Example 11

[0228]

[0229] 1412.6g methylphosphonic acid was loaded into a 1L reaction vessel, which was then heated to 165°C under nitrogen purge (4L / min) at 250RPM stirring. 78.2g of iron oxide was added in batches without causing a large amount of heat release. The reaction mixture was heated at 165°C for about 24 hours. The product reaction mixture containing the off-white slurry product was then cooled to about 130°C and poured into 1.5L of water in a beaker cooled in an ice-water bath. The product was separated by filtration, washed with an additional 500mL×3 of water, and dried to produce fine off-white crystals of 83% yield. According to the following empirical formula, the product has a phosphorus-iron ratio of 4:1 (ICP elemental analysis):

[0230]

[0231] The above product empirical formula represents the repeating monomer units (ie, coordination entities) of the coordination polymer that form the pure crystalline product.

[0232] Example 12

[0233] The combined flame retardants and stabilizers disclosed herein were evaluated in polyamide-6,6 thermoplastic compositions. The ingredients are listed below and shown in Table 1, including the ratios of the blended components.

[0234] Thermoplastic polymers:

[0235] Polyamide-6,6 (from Nilit P-50 / 2)

[0236] Inorganic fillers:

[0237] Glass fiber (from PPG 3540)

[0238] Phosphorus flame retardant (Phos-FR):

[0239] Phos-FR produced according to Example 7 above

[0240] Flame retardant synergist:

[0241] Melamine or cyanuramide

[0242] Epoxide:

[0243] Polyglycidyl ether of o-cresol novolac (Epon 164 from Hexion)

[0244] The formulations shown in Table 1 were compounded using a twin-screw extruder at 265° C. An injection molding machine was used to prepare 0.8 mm (thickness) specimens for each formulation at 255° C.-270° C. and at a mold temperature of 80° C. The flame retardant activity of each prepared formulation was evaluated under UL-94 testing and certain processing conditions.

[0245] Table 1

[0246]

[0247] As shown in Table 1, Formulations 2 and 3 each exhibited V-0 performance in the UL-94 test. As shown in Table 1, Formulation 2 (without epoxide) required the use of a lower injection molding temperature and resulted in a reduction in injection molding pressure. In contrast, Formulation 3, which contained an epoxide compound, was able to be processed at standard injection molding temperatures and was stable with each injection cycle, demonstrating the stabilizing effect of the epoxide in mitigating polymer degradation during high temperature melt processing.

[0248] In addition, Formulation 4 (without epoxy) exhibited instability during the injection molding process and exhibited V-2 performance under the UL-94 test. In contrast, Formulation 5 containing epoxy was stable during each injection cycle at standard injection molding temperature and further exhibited V-0 performance under the UL-94 test.

[0249] Although specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various modifications and changes may be made by consideration of the specification and practice of the present disclosure without departing from the scope of the invention as claimed. Therefore, it should be understood that the specification and examples are to be regarded as exemplary only, with the true scope of the present invention being indicated by the following claims and their equivalents.

Claims

1. A flame retardant and stabilizer additive composition for thermoplastic polymers, the composition comprising (A) from 1 wt% to 30 wt% of at least one phosphorus-containing flame retardant having the empirical formula (I): wherein R is H, alkyl, aryl, alkylaryl or arylalkyl, M is a metal, and y is 2 or 3 such that M (+)y is a metal cation, wherein (+)y represents the charge formally assigned to the cation, a, b and c represent the ratios of the components to which they correspond in the compound relative to each other and satisfy the charge balance equation 2(a)+c=b(y), and c is not zero, and (B) from 0.01 wt % to 2 wt % of at least one epoxide compound.

2. The flame retardant and stabilizer additive composition according to claim 1, wherein: In the empirical formula (I), a is 0, 1 or 2, b is 1 to 4, and c is 1 or 2.

3. The flame retardant and stabilizer additive composition of claim 1, wherein: y is 3, a is 1, b is 1, and c is 1.

4. The flame retardant and stabilizer additive composition according to claim 3, wherein: M is selected from Al, Ga, Sb, Fe, Co, B and Bi.

5. The flame retardant and stabilizer additive composition of claim 4, wherein: M is Al or Fe.

6. The flame retardant and stabilizer additive composition according to any one of claims 1 to 5, wherein: In the empirical formula (I), R is H, C 1-12 Alkyl, C 6-10 Aryl, C 7-18 Alkyl aryl or C 7-18 Arylalkyl, wherein the alkyl, aryl, alkylaryl or arylalkyl is unsubstituted or substituted by halogen, hydroxy, amino, C 1-4 Alkylamino, di-C 1-4 Alkylamino, C 1-4 Alkoxy, carboxyl or C 2-5 Alkoxycarbonyl substitution.

7. The flame retardant and stabilizer additive composition of claim 6, wherein: R is unsubstituted C 1-12 Alkyl, C6 aryl, C 7-10 Alkyl aryl or C 7-10 Arylalkyl.

8. The flame retardant and stabilizer additive composition of claim 6, wherein: R is unsubstituted C 1-6 alkyl.

9. The flame retardant and stabilizer additive composition of claim 8, wherein: R is selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl and tert-butyl.

10. The flame retardant and stabilizer additive composition according to any one of claims 1 to 9, wherein: M is Al, y is 3, a is 1, b is 1 and c is 1.

11. The flame retardant and stabilizer additive composition of claim 10, wherein: R is H or C 1-6 alkyl.

12. The flame retardant and stabilizer additive composition of claim 11, wherein: R is selected from methyl and ethyl.

13. The flame retardant and stabilizer additive composition of claim 1 further comprising (C) at least one flame retardant synergist and / or additional flame retardant.

14. The flame retardant and stabilizer additive composition of claim 13, wherein: Component (C) comprises a nitrogen-containing flame retardant synergist.

15. The flame retardant and stabilizer additive composition of claim 14, wherein: The nitrogen-containing synergist is selected from melamine, melam, melem, cyanuric acid amide, melamine cyanurate, dimelamine phosphate, dimelamine pyrophosphate, melamine phosphate, melamine pyrophosphate, polyphosphate melamine, polyphosphate melam, polyphosphate cyanuric acid amide, polyphosphate melem and mixed polymeric salts thereof.

16. The flame retardant and stabilizer additive composition of claim 1, wherein: The at least one epoxide compound has at least two epoxide groups.

17. The flame retardant and stabilizer additive composition of claim 16, wherein: The epoxide compound is a polyglycidyl ether or a poly(β-methylglycidyl) ether.

18. The flame retardant and stabilizer additive composition of claim 16, wherein: The epoxide compound is derived from a phenol novolac.

19. The flame retardant and stabilizer additive composition of claim 18, wherein: The phenol novolac is selected from cresol novolac, bisphenol A novolac and bisphenol F novolac.

20. The flame retardant and stabilizer additive composition of claim 16, wherein: The epoxide compound is a phenol novolac polyglycidyl ether.

21. The flame retardant and stabilizer additive composition of claim 20, wherein: The phenol novolac polyglycidyl ether has the formula (III): wherein in formula (III), R is independently selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, aryl, alkylaryl and aralkyl, and n is 0 to 1000.

22. The flame retardant and stabilizer additive composition of claim 21, wherein: In formula (III), R is a C1-C4 alkyl group.

23. The flame retardant and stabilizer additive composition of claim 20, wherein: The epoxide compound is a polyglycidyl ether of a cresol novolac having the formula (IV): Where n is 0 to 100 and represents the average.

24. The flame retardant and stabilizer additive composition of claim 17, wherein: The epoxide compound is an oligomeric reaction product of bisphenol A and epichlorohydrin having the formula (V): where a is from 0 to 100 and represents the average.

25. The flame retardant and stabilizer additive composition of claim 1 further comprising (D) one or more other stabilizers.

26. The flame retardant and stabilizer additive composition of claim 25, wherein: The one or more other stabilizers are selected from zinc borate, zinc stannate, zinc molybdate complexes, zinc molybdate / magnesium hydroxide complexes, zinc molybdate / magnesium silicate complexes, calcium molybdate / zinc complexes, and zinc phosphate complexes, polysiloxanes, montmorillonite, kaolinite, halloysite and hydrotalcite.

27. A flame retardant thermoplastic composition comprising from 30 wt% to 95 wt% of at least one thermoplastic polymer and a flame retardant and stabilizer additive composition according to any one of claims 1 to 26.

28. The flame retardant thermoplastic composition of claim 27, wherein: The at least one thermoplastic polymer is selected from the group consisting of polyesters and polyamides.

29. The flame retardant thermoplastic composition of claim 28, wherein: The at least one thermoplastic polymer is a polyamide selected from the group consisting of polyamide-4,6, polyamide-6, polyamide-6,6, polyamide-6,10, polyamide-6,12, polyamide-11, polyamide-12, polyamide-4,T, polyamide-MXD,6, polyamide-12,T, polyamide-10,T, polyamide-9,T, polyamide-6,T / 6,6, polyamide-6,T / D,T, polyamide-6,6 / 6,T / 6,I, polyamide-6 / 6,T, polyamide-6,T / 6,I and mixtures thereof.

30. The flame retardant thermoplastic composition of claim 27, further comprising at least one inorganic filler.

31. The flame retardant thermoplastic composition of claim 30, wherein: The inorganic filler includes glass fibers.

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