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% as observed under a polarization microscope, an optical anisotropic structure of a "rough flow type", 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 pyridien-insoluble matter. Then, from the soluble matter, pyridine was removed to obtain a pyrildine-soluble pitch. The pitch had ΔTg of 33° 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 pyridien-insoluble matter
6. customThen, from the soluble matter, pyridine was removed
7. customto obtain a pyrildine-soluble pitch
8. customΔTg of 33° C. and Qi of not more than 1% by weight

ORD record

ord-7fecb5693a824bec87565e573f5220fa

Source dataset

uspto-grants-1997_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05643546