FLAME-RETARDANT POLYESTER COMPOSITION AND ARTICLE
A polyester composition includes specific amounts of a poly(alkylene terephthalate), an impact modifier, glass fibers, and a flame retardant. The impact modifier includes a polyolefin elastomer, optionally in combination with a thermoplastic polyester elastomer. The flame retardant includes a metal dialkylphosphinate, a melamine based flame retardant, and a flame retardant synergist that can be an organophosphine oxide, an oligomeric or polymeric bis(phenoxy)phosphazene, an organophosphate ester, or a combination thereof. The composition is useful for fabricating parts for electrical and electronic devices.
1 . A composition, comprising:
35 to 76 weight percent of a poly(alkylene terephthalate);
2 to 6 weight percent of an impact modifier comprising a polyolefin elastomer comprising an ethylene/1-octene copolymer, and, optionally, a thermoplastic polyester elastomer, provided that the amount of polyolefin elastomer does not exceed 5 weight percent;
10 to 50 weight percent glass fibers; and
14 to 25 weight percent of a flame retardant comprising
5 to 15 weight percent of a metal dialkylphosphinate,
2 to 8 weight percent of a melamine-based flame retardant, and
1 to 6 weight percent of a flame retardant synergist comprising an organophosphine oxide, an oligomeric or polymeric bis(phenoxy)phosphazene,
an organophosphate ester, or a combination thereof;
wherein all weight percent values are based on the total weight of the composition.
2 . The composition of claim 1 , wherein the poly(alkylene terephthalate) comprises alkylene groups comprising ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,4-cyclohexylene, 1,4-cyclohexanedimethylene, or a combination thereof.
3 . The composition of claim 1 , wherein the poly(alkylene terephthalate) comprises poly(ethylene terephthalate), poly(butylene terephthalate), or a combination thereof.
4 . The composition of claim 1 , wherein the poly(alkylene terephthalate) comprises poly(butylene terephthalate).
5 .- 6 . (canceled)
7 . The composition of claim 1 , wherein the impact modifier comprises the thermoplastic polyester elastomer, and wherein the thermoplastic polyester elastomer comprises a poly(alkylene iso-/terephthalate)-b-poly(alkylene ether).
8 . The composition of claim 7 , wherein the thermoplastic polyester elastomer comprises a poly(butylene iso-/terephthalate)-b-poly(butylene ether).
9 . (canceled)
10 . The composition of claim 1 , wherein the metal dialkylphosphinate comprises aluminum tris(diethylphosphinate).
11 . The composition of claim 1 , wherein the melamine-based flame retardant comprises melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melamine cyanurate, or a combination thereof.
12 . The composition of claim 1 , wherein the melamine-based flame retardant comprises melamine polyphosphate.
13 . The composition of claim 1 , wherein the flame retardant synergist comprises triphenylphosphine oxide, oligomeric bis(phenoxy)phosphazene, or a combination thereof.
14 . The composition of claim 1 , wherein the flame retardant synergist comprises triphenylphosphine oxide and oligomeric bis(phenoxy)phosphazene.
15 . The composition of claim 1 , further comprising 0.5 to 3 weight percent of a polyetherimide.
16 . The composition of claim 1 , comprising 0 to 0.05 weight percent of organic phosphonates of the formula
wherein
R is hydrogen, C 1 -C 20 alkyl, unsubstituted or C 1 -C 4 alkyl-substituted phenyl or naphthyl, R′ is hydrogen, C 1 -C 20 alkyl, unsubstituted or C 1 -C 4 alkyl-substituted phenyl or naphthyl or M 1 1+ /r, n is an integer from 0 to 6, M 1 1+ is an r-valent metal ion or the ammonium ion, r is an integer from 1 to 4,
R 13 is isopropyl, isobutyl, tert-butyl, cyclohexyl or is cycloalkyl substituted by from 1 to 3 C 1 -C 4 alkyl groups,
R 14 is hydrogen, C 1 -C 4 alkyl, cycloalkyl or is cyclohexyl substituted by from 1 to 3 C 1 -C 4 alkyl groups, and
R 15 is hydrogen, C 1 -C 18 alkyl, trimethylsilyl, benzyl, phenyl or sulfonyl.
17 . The composition of claim 1 ,
wherein the poly(alkylene terephthalate) comprises poly(butylene terephthalate);
wherein the impact modifier comprises the thermoplastic polyester elastomer, and the thermoplastic polyester elastomer comprises a poly(butylene phthalate-co-alkylene ether phthalate);
wherein the flame retardant comprises aluminum tris(diethylphosphinate), melamine polyphosphate, triphenylphosphine oxide, and an oligomeric bis(phenoxy)phosphazene;
wherein the composition further comprises a polyetherimide; and
wherein the composition comprises
42 to 52 weight percent of the poly(alkylene terephthalate),
3 to 6 weight percent of the impact modifier,
1.5 to 4.5 weight percent of the ethylene/1-octene copolymer,
0.5 to 3 weight percent of the poly(butylene phthalate-co-alkylene ether phthalate),
25 to 35 weight percent of the glass fibers,
14 to 21 weight percent of the flame retardant,
8 to 12 weight percent of the aluminum tris(diethylphosphinate),
2 to 6 weight percent of the melamine polyphosphate,
1 to 4 weight percent of the triphenylphosphine oxide, and
0.5 to 3 weight percent of the oligomeric bis(phenoxy)phosphazene.
18 . An article comprising a composition, comprising:
35 to 76 weight percent of a poly(alkylene terephthalate);
2 to 6 weight percent of an impact modifier comprising a polyolefin elastomer comprising an ethylene/1-octene copolymer, and, optionally, a thermoplastic polyester elastomer, provided that the amount of polyolefin elastomer does not exceed 5 weight percent;
10 to 50 weight percent glass fibers; and
14 to 25 weight percent of a flame retardant comprising
5 to 15 weight percent of a metal dialkylphosphinate,
2 to 8 weight percent of a melamine-based flame retardant, and
1 to 6 weight percent of a flame retardant synergist comprising an organophosphine oxide, an oligomeric or polymeric bis(phenoxy)phosphazene,
an organophosphate ester, or a combination thereof;
wherein all weight percent values are based on the total weight of the composition.
19 . The article of claim 18 , wherein the article is a socket for a light emitting diode, a fan blade, a fan housing, or an electrically insulating part of an electrical connector.
20 . The article of claim 18 ,
wherein the poly(alkylene terephthalate) comprises poly(butylene terephthalate);
wherein the impact modifier comprises the thermoplastic polyester elastomer, and the thermoplastic polyester elastomer comprises a poly(butylene phthalate-co-alkylene ether phthalate);
wherein the flame retardant comprises aluminum tris(diethylphosphinate), melamine polyphosphate, triphenylphosphine oxide, and an oligomeric bis(phenoxy)phosphazene;
wherein the composition further comprises a polyetherimide; and
wherein the composition comprises
42 to 52 weight percent of the poly(alkylene terephthalate),
3 to 6 weight percent of the impact modifier,
1.5 to 4.5 weight percent of the ethylene/1-octene copolymer,
0.5 to 3 weight percent of the poly(butylene phthalate-co-alkylene ether phthalate),
25 to 35 weight percent of the glass fibers,
14 to 21 weight percent of the flame retardant,
8 to 12 weight percent of the aluminum tris(diethylphosphinate),
2 to 6 weight percent of the melamine polyphosphate,
1 to 4 weight percent of the triphenylphosphine oxide, and
0.5 to 3 weight percent of the oligomeric bis(phenoxy)phosphazene.