1. A flame retardant composition comprising (i) 100 parts by weight of a polycarbonate; (ii) from about 5 parts to about 40 parts by weight of glass fibers; (iii) from about 5 parts to about 30 parts by weight of a polysiloxane-polycarbonate copolymer; (iv) from about 0.0001 parts to about 0.2 parts by weight of an aromatic sulfone sulfonate; (v) from about 0.002 parts to about 0.5 parts by weight of an aromatic sulfonate; and (vi) optionally from about 0.01 parts to about 0.3 parts by weight of an anti-drip agent, wherein a molded sample of the composition is able to achieve a UL 94 V0 rating at a thickness of 1.6 mm.
2. The flame retardant composition according to claim 1, wherein a molded sample of the composition is able to achieve a UL 94 V0 rating at a thickness of 1.2 mm.
3. The flame retardant composition according to claim 1, in which the aromatic sulfone sulfonate comprises a formula (K-1) compound:
wherein R1, R2, and R3 are independently selected from a C1-C6 alkyl group; M is a metal; n is an integer and 1\u2266n\u22663; w is an integer and 0\u2266w\u22665; p and q are integers, p\u22670, q\u22670, and p+q\u22664.
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 R4 is selected from a C1-C6 alkyl group; M is a metal; n is an integer and 1\u2266n\u22663; y is an integer and 0\u2266y\u22665.
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 anti-drip agent comprises a fluoropolymer-based anti-drip agent.
8. The flame retardant composition according to claim 7, in which the content of halogen is controlled to be no more than about 0.1% by weight, based on the total weight of the composition.
9. The flame retardant composition according to claim 1, in which the anti-drip agent comprises TSAN.
10. The flame retardant composition according to claim 1, which comprises (i) 100 parts by weight of polycarbonate; (ii) from about 5 parts to about 40 parts by weight of glass fibers; (iii) from about 5 parts to about 30 parts by weight of a polysiloxane-polycarbonate copolymer; (iv) from about 0.0001 parts to about 0.2 parts by weight of KSS; (v) from about 0.002 parts to about 0.5 parts by weight of NaTS; and
(vi) optionally from about 0.01 parts to about 0.26 parts by weight of TSAN.
11. The flame retardant composition according to claim 10, which comprises from about 0.00066 parts to about 0.001 parts by weight of KSS.
12. The flame retardant composition according to claim 10, which comprises from about 0.04 parts to about 0.055 parts by weight of NaTS.
13. The flame retardant composition according to claim 10, which comprises from about 0.15 parts to about 0.26 parts by weight of TSAN.
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 A1 and A2 is a monocyclic divalent aryl radical and Y1 is a bridging radical having one or two atoms that separate A1 from A2.
15. The flame retardant composition according to claim 1, in which the polycarbonate comprises repeating structural carbonate units of the formula (A-2):
wherein Ra and Rb 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 Xa represents one of the groups of formula (5):
wherein Rc and Rd each independently represent a hydrogen atom or a monovalent linear or cyclic hydrocarbon group and Re 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 polysiloxane-polycarbonate copolymer comprises from about 50% by weight to about 99% by weight of carbonate units and from about 1% by weight to about 50% by weight of siloxane units.
18. The flame retardant composition according to claim 1, in which the amount of the polysiloxane-polycarbonate copolymer is from about 12% by weight to about 20% by weight, based on the total weight of component (i) polycarbonate in the composition.
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, fillerreinforcing 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.
21. A flame retardant composition comprising (i) 100 parts by weight of a polycarbonate; (ii) from about 6 parts to about 20 parts by weight of glass fibers; (iii) from about 12 parts to about 20 parts by weight of a polysiloxane-polycarbonate copolymer; (iv) from about 0.0003 parts to about 0.01 parts by weight of potassium diphenylsulfone sulfonate (KSS); and (v) from about 0.006 parts to about 0.01 parts by weight of the sodium salt of toluene sulfonic acid (NaTS), wherein a molded sample of the composition is able to achieve a UL 94 V0 rating at a thickness of 1.6 mm.
22. The composition of claim 21, wherein the composition comprises from about 0.00044 to about 0.005 parts by weight of KSS and from about 0.008 to about 0.05 parts by weight of NaTS.
23. The composition of claim 21, wherein the polycarbonate contains no halogen atoms.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. In an internal combustion engine, a rotary valve assembly comprising
a shaft rotatable about an axis and having a hole transverse to the axis; and
at least one elastomeric damper for changing a resonant frequency of said shaft, said damper being molded onto the shaft and comprising an anchor portion extending within the hole.
2. A valve assembly in accordance with claim 1 wherein said resonant frequency is less than about 660 Hz.
3. A valve assembly in accordance with claim 1 further including a rotary air control valve mounted on the shaft apart form the damper.
4. A valve assembly in accordance with claim 1 disposed within said engine, wherein said at least one elastomeric damper is disposed between said shaft and said engine whereby said shaft is acoustically grounded to said engine for changing said resonant frequency of said shaft.
5. A valve assembly in accordance with claim 4 wherein the shaft is rotatably mountable to said engine at opposite ends of said shaft.
6. A valve assembly in accordance with claim 4 further comprising at least one butterfly vane disposed on said shaft.
7. A valve assembly in accordance with claim 6 wherein material forming said butterfly vane includes nylon.
8. A valve assembly in accordance with claim 6 wherein at least a portion of said butterfly vane includes an elastomer.
9. A valve assembly in accordance with claim 4 further comprising a plurality of said at least one elastomeric damper, said plurality of dampers being spaced apart along said shaft.
10. A valve assembly in accordance with claim 1 wherein said at least one elastomeric damper is formed from an elastomer having a durometer value of about 55.
11. A valve assembly in accordance with claim 1 wherein said at least one elastomeric damper is formed of silicone rubber.
12. A rotary valve assembly for an internal combustion engine comprising
a shaft rotatable about an axis and having a first anchor hole transverse to the axis and a second anchor hole transverse to the axis and perpendicular to the first anchor hole;
a butterfly vane affixed to the shaft and including an anchor portion extending through the first anchor hole; and
an elastomeric damper affixed to the shaft apart from the butterfly vane and including an anchor portion extending through the second hole, said elastomeric damper being effective to acoustically ground the shaft to the engine for changing the resonant frequency thereof.