Flame-resistant polycarbonate film
View Patent ↗A polycarbonate film having a thickness of 0.05 mm to 0.25 mm is formed from a thermoplastic composition that includes a first branched polycarbonate that has a peak melt viscosity of at least 7,000 poise when measured using a parallel plate melt rheology test at a heating rate of 10° C./min at a temperature of between 350° C. to 450° C., a second branched polycarbonate, and a perfluoroalkyl sulfonate salt.
1. A plastic film having a thickness of 0.05 mm to 0.25 mm, comprising a thermoplastic composition that comprises:
a first polycarbonate derived from a dihydroxy compound and a carbonate source, comprising repeat units according to formula (1)
wherein at least 60 percent of the total number of R 1 groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic;
wherein the first polycarbonate further comprises branching groups derived from a first branching agent and end-capping groups derived from an end-capping agent; and
wherein the first polycarbonate has a peak melt viscosity of at least 7,000 poise when measured using a parallel plate melt rheology test at a heating rate of 10° C./min at a temperature of between 350° C. to 450° C.; and
a second polycarbonate comprising repeat units according to formula (1)
wherein at least 60 percent of the total number of R 1 groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic, and wherein the second polycarbonate further comprises a second branching agent; and
a perfluoroalkyl sulfonate salt;
wherein the end-capping groups of the first polycarbonate comprise cyanophenyl carbonate groups, or wherein the first polycarbonate is configured so as to have molecular weight, branching agent content, and end-capping agent such that a calculated peak melt viscosity equals at least 7000 poise according to the equation: −57135.91+36961.39*BL+14001.13*MW 1/3 −46944.24*pKa−322.51*BL*MW 1/3 −2669.19*BL*pKa+215.83* MW 1/3 *pKa+1125.63*BL 2 -200.11*MW 2/3 +2231.15*pKa 2 , wherein “MW” is the weight-averaged molecular weight as determined by gel permeation chromatography using polycarbonate standards, “BL” (branching level) is defined as the ratio of number of moles of first branching groups divided by the number of moles of R 1 groups in the first polycarbonate, and “pKa” is the pKa of the end-capping agent, or wherein the end-capping groups of the first polycarbonate comprise cyanophenyl carbonate groups and the first polycarbonate is configured so as to have molecular weight, branching agent content, and end-capping agent such that a calculated peak melt viscosity equals at least 7000 poise according to the equation: −57135.91+36961.39*BL+14001.13*MW 1/3 −46944.24*pKa−322.51*BL* MW 1/3 −2669.19*BL*pKa+215.83*MW 1/3 *pKa+1125.63*BL 2 −200.11*MW 2/3 +2231.15*pKa 2 .
2. The film of claim 1 , wherein said end-capping groups of the first polycarbonate comprise cyanophenyl carbonate endcapping groups.
3. The film of claim 2 , wherein the cyanophenyl carbonate endcapping groups are present in an amount of 2 to 20 cyanophenyl carbonate units per 100 R 1 units in the first polycarbonate.
4. The film of claim 2 , wherein the cyanophenol carbonate endcapping groups are derived from a cyanophenol of the formula
wherein Y is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, y is 0 to 4, and c is 1 to 5, provided that y+c is 1 to 5.
5. The film of claim 2 , wherein the cyanophenol carbonate endcapping groups are derived from p-cyanophenol, 3,4-dicyanophenol, or a combination comprising at least one of the foregoing phenols.
6. The film of claim 2 , wherein the first branching agent comprises tris-hydroxyphenyl ethane or trimellitic trichloride or a combination of least one of the foregoing groups.
7. The film of claim 2 , wherein the branching groups of the first polycarbonate are present in an amount of from 0.75 to 5 branching groups per 100 R 1 units of the first polycarbonate.
8. The film of claim 2 , wherein the first branching agent comprises:
a triacid trichloride of the formula
wherein Z is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and z is 0 to 3;
a tri-substituted phenol of the formula
wherein T is a C 1-20 alkyl group, C 1-20 alkyleneoxy group, C 7-12 arylalkyl, or alkylaryl group, R s is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and s is 0 to 4; or
a structure of the formula
or a combination of comprising one or more of the above.
9. The film of claim 8 , wherein the first branching agent comprises a tri-substituted phenol of the formula
wherein T is a C 1-20 alkyl group, C 1-20 alkyleneoxy group, C 7-12 arylalkyl, or alkylaryl group, R s is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and s is 0 to 4.
10. The film of claim 8 , wherein the first branching agent comprises a triacid trichloride of the formula:
wherein Z is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and z is 0 to 3.
11. The film of claim 1 , wherein the first polycarbonate is configured so as to have molecular weight, branching agent content, and end-capping agent such that a calculated peak melt viscosity equals at least 7000 poise according to the equation: −57135.91+36961.39*BL+14001.13*MW 1/3 −46944.24*pKa−322.51*BL*MW 1/3 −2669.19*BL*pKa+215.83*MW 1/3 *pKa+1125.63*BL 2 −200.11*MW 2/3 +2231.15* pKa 2 , wherein “MW” is the weight-averaged molecular weight as determined by gel permeation chromatography using polycarbonate standards, “BL” (branching level) is defined as the ratio of number of moles of first branching groups divided by the number of moles of R 1 groups in the first polycarbonate, and “pKa” is the pKa of the end-capping agent.
12. The film of claim 11 , wherein the end-capping agent has a pKa of 8.3 to 11.
13. The film of claim 11 , wherein the end-capping agent has a pKa of 8.3 to 10.2.
14. The film of claim 11 , wherein the end-capping agent comprises phenol or a phenol containing one or more substitutions comprising aliphatic groups, olefinic groups, aromatic groups, halogens, ester groups, ether groups, or halogens, or a combination comprising at least one of the foregoing.
15. The film of claim 11 , wherein the end-capping agent comprises phenol, p-t-butylphenol, p-cumylphenol, or a combination comprising at least one of the foregoing.
16. The film of claim 11 , wherein BL is greater than or equal to 0.01.
17. The film of claim 11 , wherein BL is greater than or equal to 0.02.
18. The film of claim 11 , wherein BL is greater than or equal to 0.03.
19. The film of claim 11 , wherein the first branching agent comprises THPE, TMTC, isatin-bis-phenol, or a combination comprising at least one of the foregoing.
20. The film of claim 1 , comprising from 5 to 79.999 wt. % of the first polycarbonate, from 94 to 20 wt. % of the second polycarbonate, and from 0.001 to 1 wt. % of the perfluoroalkyl sulfonate salt.
21. The film of claim 1 , wherein the second polycarbonate has a peak melt viscosity of less than 7,000 poise when measured using a parallel plate melt rheology test at a heating rate of 10° C/min at a temperature of between 350° C. to 450° C.
22. The film of claim 1 , wherein the perfluoroalkyl sulfonate salt is potassium perfluorobutane sulfonate (Rimar salt), potassium perfluoroctane sulfonate, tetraethylammonium perfluorohexane sulfonate, or a combination comprising any of the foregoing.
23. The film of claim 1 , wherein the thermoplastic composition achieves a UL94 VTM-0 classification when tested as a test sample having a thickness of 0.05 mm.
24. The film of claim 1 , wherein the thermoplastic composition is substantially free of bromine and chlorine.
25. The film of claim 1 , wherein the first and second polycarbonates are substantially free of bromine and chlorine.
26. The film of claim 1 , wherein the first branching agent comprises:
a triacid trichloride of the formula
wherein Z is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and z is 0 to 3;
a tri-substituted phenol of the formula
wherein T is a C 1-20 alkyl group, C 1-20 alkyleneoxy group, C 7-12 arylalkyl, or alkylaryl group, R s is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and s is 0 to 4; or
a structure of the formula
or a combination of comprising one or more of the above structures.
27. The film of claim 26 , wherein the first branching agent comprises a tri-substituted phenol of the formula
wherein T is a C 1-20 alkyl group, C 1-20 alkyleneoxy group, C 7-12 arylalkyl, or alkylaryl group, R s is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and s is 0 to 4.
28. The film of claim 26 , wherein the first branching agent comprises a triacid trichloride of the formula
wherein Z is a halogen, C 1-3 alkyl group, C 1-3 alkoxy group, C 7-12 arylalkyl, alkylaryl, or nitro group, and z is 0 to 3.
29. A method of using the film of claim 1 , comprising disposing the film adjacent to an electrical or electronic component or between electrical or electronic components.
30. An article comprising an electrical or electronic component and an electrical insulator comprising the film of claim 1 .
31. The article of claim 30 , which is a printed circuit board or battery.
32. The article of claim 31 , wherein the article is a flexible printed circuit board.