Halogen-free polycarbonate compositions and articles formed therefrom
A halogen-free polycarbonate composition is disclosed having improved fire-retardancy and/or transparency characteristics. The composition comprises a polycarbonate, and a synergic combination of an aromatic sulfone sulfonate such as potassium diphenylsulfone sulfonate, an aromatic sulfonate such as sodium salt of toluene sulfonic acid, and optionally a siloxane oligomer. The polycarbonate composition is useful for manufacture of electronic and mechanical parts, among others.
1 . A flame retardant composition comprising (i) 100 parts by weight of polycarbonate; (ii) from about 0.0001 parts to about 0.2 parts by weight of an aromatic sulfone sulfonate; (iii) from about 0.002 parts to about 0.2 parts by weight of an aromatic sulfonate; (iv) optionally from about 0.05 parts to about 2 parts by weight of a siloxane oligomer, wherein a molded sample of the composition is able to achieve a UL 94 V0 rating at a thickness of 3.0 mm.
2 . The flame retardant composition of claim 1 , wherein a molded sample of the composition is able to achieve a UL 94 V0 rating at a thickness of 2.5 mm.
3 . The flame retardant composition according to claim 1 , in which the aromatic sulfone sulfonate comprises a formula (K-1) compound:
wherein R 1 , R 2 , and R 3 are independently selected from a C 1 -C 6 alkyl group; M is a metal; n is an integer and 1≦n≦3; w is an integer and 0≦w≦5; p and q are integers, p≧0, q≧0, and p+q≦4.
4 . The flame retardant composition according to claim 1 , in which the aromatic sulfone sulfonate comprises a formula (K-2) compound or potassium diphenylsulfone sulfonate (KSS):
5 . The flame retardant composition according to claim 1 , in which the aromatic sulfonate comprises a formula (N-1) compound:
wherein R 4 is selected from a C 1 -C 6 alkyl group; M is a metal; n is an integer and 1≦n≦3; y is an integer and 0≦y≦5.
6 . The flame retardant composition according to claim 1 , in which the aromatic sulfonate comprises a formula (N-2) compound or a sodium salt of toluene sulfonic acid (NaTS):
7 . The flame retardant composition according to claim 1 , in which the siloxane oligomer comprises a formula (P-1) compound:
wherein R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R a and R b are independently selected from a C 1 -C 8 alkyl group such as methyl and ethyl, or an arylalkyl group such as phenylmethyl, phenylethyl, and phenylpropyl, or an aryl group such as phenyl; x is an integer; and 1≦x≦10.
8 . The flame retardant composition according to claim 1 , in which the siloxane oligomer comprises a formula (P-2) compound:
9 . The flame retardant composition according to claim 1 , further comprising a Si-additive having the formula as shown below:
R 1 a Si(OR 2 ) b O (4-a-b)/2
where R 1 is a substituted or unsubstituted univalent hydrocarbon group containing an aryl group as an essential component; R 2 is a substituted or unsubstituted univalent hydrocarbon group; R 1 and R 2 may be the same as or different from each other; 0.2≦a≦2.7; 0.2≦b≦2.4; and a+b≦3.
10 . The flame retardant composition according to claim 1 , which comprises (i) 100 parts by weight of polycarbonate; (ii) from about 0.0001 parts to about 0.2 parts by weight of KSS; (iii) from about 0.002 parts to about 0.2 parts by weight of NaTS; and (iv) optionally from about 0.05 parts to about 2 parts by weight of bi-phenylpropyl dimethicone (SI-ADDITIVE 1).
11 . The flame retardant composition according to claim 10 , which comprises from about 0.01 parts to about 0.08 parts by weight of KSS.
12 . The flame retardant composition according to claim 10 , which comprises from about 0.01 parts to about 0.08 parts by weight of NaTS.
13 . The flame retardant composition according to claim 10 , which comprises from about 0.3 parts to about 0.8 parts by weight of SI-ADDITIVE 1.
14 . The flame retardant composition according to claim 1 , in which the polycarbonate comprises repeating structural carbonate units of the formula (A-1):
wherein each of A 1 and A 2 is a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 .
15 . The flame retardant composition according to claim 1 , in which the polycarbonate comprises repeating structural carbonate units of the formula (A-2):
wherein R a and R b each represent a halogen atom or a monovalent hydrocarbon group and may be the same or different; p and q are each independently integers of 0 to 4; and X a represents one of the groups of formula (5):
wherein R c and R d each independently represent a hydrogen atom or a monovalent linear or cyclic hydrocarbon group and R e is a divalent hydrocarbon group.
16 . The flame retardant composition according to claim 1 , in which the polycarbonate comprises repeating structural carbonate units of the formula (A-3):
17 . The flame retardant composition according to claim 1 , in which the polycarbonate is linear or branched.
18 . The flame retardant composition according to claim 1 , in which the polycarbonate comprises a mixture of high flow polycarbonate and Normal Flow polycarbonate.
19 . The flame retardant composition according to claim 1 , further comprising one or more optional additives selected from the group consisting of hydrolysis stabilizer, impact modifier, filler/reinforcing agent, visual effect enhancer, antioxidant, heat stabilizer, light stabilizer, ultraviolet light absorber, plasticizer, mold release agent, lubricant, antistatic agent, pigment, dye, processing aid, radiation stabilizer, and combinations thereof.
20 . A flame retardant article made from the composition according to claim 1 , which is substantially transparent and free of halogen.
21 . The article of claim 20 , which is an electronic or mechanical part.
22 . A flame retardant article molded from a composition comprising an effective amount of a polycarbonate, an aromatic sulfone sulfonate, an aromatic sulfonate, and, optionally, a siloxane oligomer to exhibit a UL 94 V0 flammability rating at 3.0 mm or less.
23 . A flame retardant article according to claim 22 , wherein the article is substantially transparent and free of halogen.
24 . The flame retardant composition of claim 23 , wherein the composition also exhibits light transmittance of 90% or more.
25 . The flame retardant composition of claim 1 , wherein the composition also exhibits a haze of 1.4% or less.
26 . A flame retardant article made from the composition according to claim 25 , which is substantially transparent and free of halogen.
27 . A flame retardant composition comprising (i) 100 parts by weight polycarbonate, wherein the polycarbonate comprises repeating structural units of the formula (A-2)
wherein X a is cyclohexane and R a and R b are each methyl, and p and q are each 1; (ii) from about 0.0001 parts to about 0.2 parts by weight of an aromatic sulfone sulfonate; (iii) from about 0.002 to about 0.2 parts by weight of an aromatic sulfonate, wherein a molded sample of the composition is able to achieve a UL94 V0 rating at a thickness of 3.0 mm.
28 . The flame retardant composition of claim 27 wherein the polycarbonate comprises repeating structural units of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane).
29 . The flame retardant composition of claim 27 wherein the aromatic sulfone sulfonate is potassium diphenylsulfone sulfonate.
30 . The flame retardant composition of claim 27 wherein the aromatic sulfonate is a sodium salt of sulfonic acid.
31 . The flame retardant composition of claim 28 wherein the aromatic sulfonate is a sodium salt of sulfonic acid.
32 . The flame retardant composition of claim 27 further comprising from about 0.5 to about 2 parts by weight of a siloxane oligomer.
33 . The flame retardant composition of claim 30 further comprising from about 0.5 to about 2 parts by weight of a siloxane oligomer.
34 . The flame retardant composition of claim 32 , wherein the polycarbonate comprises a blend of a linear polycarbonate and a branched polycarbonate.
35 . An article comprising the composition of claim 27 .
36 . The flame retardant composition of claim 15 , wherein X a is cyclohexane and R a and R b are each methyl, and p and q are each 1.
37 . The flame retardant composition of claim 1 , wherein the polycarbonate comprises two polycarbonates, wherein the first polycarbonate comprises repeating structural carbonate units of the formula (A-3):
and the second polycarbonate comprises repeating structural units of formula (A-2)
wherein X a is cyclohexane and R a and R b are each methyl, and p and q are each 1.
38 . An article comprising the composition of claim 36 .
39 . The flame retardant composition of claim 36 , wherein the polycarbonate comprises a blend of a linear polycarbonate and a branched polycarbonate.
40 . The flame retardant composition of claim 37 , wherein the second polycarbonate comprises repeating structural units of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane).