| 摘要 |
1428012 Phenolic resin fibres KANEBO KK 5 Sept 1973 [5 Sept 1972 (2)] 41804/73 Heading B5B [Also in Divisions D1-D2 and C3] Phenolic fibres having a degree of hardening of 3-30% by wt. and which have been produced by cross-linking melt spun phenolic resin fibres with an aldehyde are used in the manufacture of heat- and flame-resistant papers (see Divisions D1-D2). The fibres may be produced by condensing a phenol or modified phenol with an aldehyde to form a novolak or resol resin which is extruded into filaments. The latter are then hardened by treatment with, for example, formaldehyde in the presence of HCl as catalyst. Urea, ethylene urea, or a methylol derivative thereof, may also be present. The phenolic fibres may be modified by incorporating a thermoplastic polymer in the melt from which the fibres are spun. The fibres may have a denier of from 0À1 to 20 and a length of from 0À3 to 100 mm. |
