Pyridine → Naphthalene

Naphthalene was polymerized at a temperature of from 200° to 400° C. in the presence of a HF.BF3 catalyst to obtain a pitch which had an optical anisotropy of 100%, a Mettler softening point of 250° C. and an elemental composition as analyzed of C: 94.8 wt % and H: 5.2 wt %. This pitch was finely pulverized. Then, pyridine (solubility parameter: 10.6) was added in an amount of 200 ml to 5 g of this pitch, and extraction was conducted at 100° C., followed by filtration with a 0.5 μm membrane filter to remove a pyridine-insoluble matter. Then, a solvent mixture of toluene/hexane=40 volume %/60 volume % (solubility parameter: 7.9) was added in an amount of 150 ml to 3 g of the soluble matter, and extraction was conducted at about 70° C., followed by filtration with a 0.5 μm membrane filter to remove a soluble matter. From the insoluble matter, the solvent was removed to obtain a spinning pitch. The pitch had ΔTg of 27° C. and Qi of not more than 1% by weight.

1. customa Mettler softening point of 250° C.
2. customwas conducted at 100° C.
3. filtrationfollowed by filtration with a 0.5 μm membrane
4. filtrationfilter
5. customto remove a pyridine-insoluble matter
6. additionThen, a solvent mixture of toluene/hexane=40 volume %/60 volume % (solubility parameter: 7.9)
7. additionwas added in an amount of 150 ml to 3 g of the soluble matter, and extraction
8. customwas conducted at about 70° C.
9. filtrationfollowed by filtration with a 0.5 μm membrane
10. filtrationfilter
11. customto remove a soluble matter
12. customFrom the insoluble matter, the solvent was removed
13. customto obtain a spinning pitch
14. customΔTg of 27° C. and Qi of not more than 1% by weight

ORD record

ord-af6247ad430247a9821c331b8d906ff7

Source dataset

uspto-grants-1997_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05643546