Amorphous polycarbonate films for capacitors, methods of manufacture, and articles manufactured therefrom
View Patent ↗A film comprising a copolycarbonate, wherein the film is a uniaxially-stretched, extruded film comprising at least one film region having: an average thickness of more than 0 and less than 14 micrometers with a standard deviation of 0.8 micrometer to 1.6 micrometers, a surface having a surface roughness average of less than 0.04 micrometer as measured by optical profilometry, a dielectric constant at 1 kHz and room temperature of at least 2.7, a dissipation factor at 1 kHz and room temperature of 1% or less, and a breakdown strength of at least 620 Volt/micrometer; and the copolycarbonate has a Tg of greater than 180° C. and comprises carbonate units derived from a bisphenol compound of the formula (3).
1. A film comprising a copolycarbonate, wherein
the film is a uniaxially-stretched, extruded film comprising at least one film region having:
an average thickness of more than 0 and less than 14 micrometers with a standard deviation of 0.8 micrometer to 1.6 micrometers,
a surface having a surface roughness average of less than 0.04 micrometer as measured by optical profilometry,
a dielectric constant at 1 kHz and room temperature of at least 2.7,
a dissipation factor at 1 kHz and room temperature of 1% or less, and
a breakdown strength of at least 620 Volt/micrometer; and
the copolycarbonate has a Tg of greater than 180° C. and comprises carbonate units derived from polymerization of 2,2-bis(4-hydroxyphenyl) propane and 2-phenyl-3,3-bis(4-hydroxyphenyl) phthalimidine.
2. A film comprising a copolycarbonate, the film is a uniaxially-stretched, extruded film comprising at least one film region having:
an average thickness of more than 0 and less than 14 micrometers with a standard deviation of 0.8 micrometer to 1.6 micrometers,
a surface having a surface roughness average of less than 0.04 micrometer as measured by optical profilometry,
a dielectric constant at 1 kHz and room temperature of at least 2.7,
a dissipation factor at 1 kHz and room temperature of 1% or less, and
a breakdown strength of at least 620 Volt/micrometer; and
the copolycarbonate has a Tg of greater than 180° C. and comprises carbonate units derived from a bisphenol compound of the formula
wherein
R a and R b are each independently a halogen atom or a monovalent hydrocarbon group,
p and q are each independently integers of 0 to 4, and
wherein X a is cyclododecylidene or adamantylidene.
3. The film of claim 1 , wherein the copolycarbonate has a Tg of 181.5° C. to 196° C.
4. The film of claim 1 , wherein the film region has an average breakdown strength of greater than 900 Volts/micrometer with a standard deviation of 106 Volts/micrometer.
5. The film of claim 1 , wherein the film region has a roughness value of less than 0.02 micrometer.
6. The film of claim 1 , wherein no polymer other than the copolycarbonate is present in the film.
7. The film of claim 1 , wherein
the film has a length of at least 10 meters, and a width of at least 300 millimeters; and
the film region is at least 80% of the area of the film.
8. The film of claim 1 , wherein the film has a length of 100 to 10,000 meter, and a width of 300 to 3,000 millimeter.
9. The film of claim 1 , wherein the film has less than 1,000 ppm of a compound having a molecular weight of less than 250 Dalton.
10. The film of claim 1 , wherein the film has less than 50 ppm each of aluminum, calcium, magnesium, iron, nickel, potassium, manganese, molybdenum, sodium, titanium, and zinc.
11. The film of claim 1 , comprising less than 1000 ppm each of a fluorine-containing compound or a silicone-containing compound.
12. The film of claim 1 , comprising less than 100 ppm of a fluorine-containing compound or a silicone-containing compound.
13. The film of claim 1 , wherein the film region has a roughness value Ra of less than 3% of the average thickness of the film.
14. An article comprising the film of claim 1 , and a layer of a conductive metal deposited on at least a portion of the surface of the film.
15. The article of claim 14 , wherein the conductive metal comprises aluminum, zinc, copper, or a combination comprising at least one of the foregoing.
16. The article of claim 15 , wherein the conductive metal layer has a thickness of 1 to 3000 Angstroms.
17. A capacitor comprising the article of claim 14 .
18. An electronic article comprising the capacitor of claim 17 .
19. The film of claim 1 further comprising an antioxidant, a thermal stabilizer, a light stabilizer, an ultraviolet light (UV) absorbing additive, a quencher, a plasticizer, a lubricant, an antistatic agent, a flame retardant, an anti-drip agent, a radiation stabilizer, or a combination comprising at least one of the foregoing.
20. The film of claim 1 further comprising a poly(phenylene sulfone), a poly(sulfone), a poly(ether sulfone), a poly(arylene sulfone), a poly(phenylene ether), a poly(etherimide), a poly(etherimide sulfone), or a combination comprising at least one of the foregoing.
21. An article comprising the film of claim 2 , and a layer of a conductive metal deposited on at least a portion of the surface of the film.
22. A capacitor comprising the article of claim 21 .
23. An electronic article comprising the capacitor of claim 22 .