Hydroxyphenyl phosphine oxide mixtures and their use as flame retardant's for epoxy resins
View Patent ↗A hydroxyphenyl or alkoxyphenyl phosphine oxide composition comprising (i) a first mixture of mono-(hydroxyphenyl) or (alkoxyphenyl) phosphine oxide isomers, (ii) a second mixture of bis-(hydroxyphenyl) or (alkoxyphenyl) phosphine oxide isomers, (iii) a third mixture of tris-(hydroxyphenyl) or (alkoxyphenyl) phosphine oxide isomers, and optionally iv) a minority amount of non-hydroxy or non-alkoxy tris-phenyl phosphine oxides is provided. Also provided are epoxy resins compositions with excellent flame retardancy and physical properties, which resins comprise the phosphine oxide composition.
1. A hydroxyphenyl or alkoxyphenyl phosphine oxide composition comprising:
(i) from about 10 to about 50 wt % of a first mixture of mono-(hydroxyphenyl) or (alkoxyphenyl) phosphine oxide isomers each having the formula (I):
(ii) from about 30 to about 60 wt % of a second mixture of bis-(hydroxyphenyl) or (alkoxyphenyl) phosphine oxide isomers each having the formula (II):
(iii) from about 10 to about 50 wt % of a third mixture of tris-(hydroxyphenyl) or (alkoxyphenyl) phosphine oxide isomers each having the formula (III):
iv) 0 to 10 mol % of triphenyl phosphine oxides of the formula IV:
wherein R is hydrogen or an alkyl group containing from 1 to 6 carbon atoms, R 1 and R 2 are the same or different and each is an alkyl group containing from 1 to 6 carbon atoms, each of x and y is an integer from 0 through 4, and each OR group is in the ortho or para position with respect to the bond between the P atom and the associated phenyl group such that, for each mixture (i), (ii) and (iii), the ratio of the number of OR groups in the ortho-position with respect to the bond between the P atom and the associated phenyl group to the number of OR groups in the para-position with respect to the bond between the P atom and the associated phenyl group is from about 20:80 to about 1:99.
2. The composition of claim 1 , wherein, for each mixture (i), (ii) and (iii), the ratio of the number of OR groups in the ortho-position with respect to the bond between the P atom and the associated phenyl group to the number of OR groups in the para-position with respect to the bond between the P atom and the associated phenyl group is from about 10:80 to about 2:98.
3. The composition of claim 1 , wherein, for each mixture (i), (ii) and (iii), the ratio of the number of OR groups in the ortho-position with respect to the bond between the P atom and the associated phenyl group to the number of OR groups in the para-position with respect to the bond between the P atom and the associated phenyl group is from about 6:94 to about 3:97.
4. The composition of claim 1 , wherein each of x and y is zero.
5. The composition of claim 1 , wherein R is hydrogen.
6. The composition of claim 1 comprising about 15 to about 30 wt % of the first mixture (i), about 40 to about 55 wt % of the second mixture (ii) and about 15 to about 30 wt % of the third mixture (iii).
7. The composition of claim 5 comprising from 1 to 10 wt % of triphenyl phosphine oxides of the formula IV: