Flame-retardant composition comprising a phosphonic acid derivative

A blend containing a synergistic mixture of (A) and (B), which denote the following:

• (A) is a compound or a mixture of 2 or more chemical compounds selected from the group consisting of
• a) one or more phosphonate compound(s) of the Formula
• where A1 and A2 independently denote a substituted or unsubstituted, straight or branched chain alkyl group having to 4 carbon atoms, substituted or unsubstituted benzyl, substituted or unsubstituted phenyl, or substituted or unsubstituted naphthyl, and
• b) one or more phosphonate compound(s) of the following Formula
• where A3 and A4 independently denote methyl or ethyl and A5 denotes a straight or branched chain alkyl group having 1 to carbon atoms or a phenyl or benzyl group having up to 3 methyl groups respectively, and
• c) alkyl or arylphosphonic acids, where alkyl denotes a straight or branched chain alkyl group having 1 to 4 carbon atoms, and aryl denotes a substituted or unsubstituted benzyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, or a salt or ester of the aforementioned phosphonic acid, and
• (B) a 1,3,5-triazine compound or a mixture of two or more 1,3,5-triazine compound(s) selected from tris-2-hydroxyethyl isocyanurate, melamine, melamine cyanurate, melamine phosphate, poly-[2,4-(piperazin-1,4-yl)-6-(morpholin-4-yl)-1,3,5-triazine], dimelamine phosphate, melamine pyrophosphate, and hindered amine compounds of Formula I, II, IIA, and III:
• R1NH—CH2CH2CH2NR2CH2CH2NR3CH2CH2CH2NHR4 (I)
• T-E1-T1 (II)
• T-E1 (IIA)
• G-E1-G1-E1-G2 (III),
• where in the tetraamine of Formula I
• R1 and R2 denote the s-triazine moiety E, and one of R3 and R4 denotes the s-triazine moiety E, with the other of R3 or R4 denoting a hydrogen,
• E denotes
• R denotes methyl, cyclohexyl or octyl,
• R5 denotes an alkyl having 1 to 12 carbon atoms,
• where in the compound of Formula II or IIA, if R denotes cyclohexyl or octyl, each of T and T1 denotes a tetraamine substituted by R1-R4 as defined in Formula I, where
• (1) one of the s-triazine moieties E in each tetraamine is replaced by the group E1, which forms a bridge between two tetraamines T and T1, or
• (2) the group E1 can have both terminals in the same tetraamine T as in Formula IIA, where two of the E moieties of the tetraamine are replaced by one E1 group, or
• (3) all three s-triazine substituents of tetraamine T can denote E1, such that one E1 residue comprises the bond between T and T1 and a second E1 residue has both terminals in tetraamine T,
• and
• E1 denotes