| 摘要 |
<p>1452629 Aminotriazine-aldehyde fibres KURARAY CO Ltd 28 Dec 1973 [29 Dec 1972 (2) 9 Feb 1973 28 Dec 1972 30 Dec 1972 29 Jan 1973] 59910/73 Heading B5B [Also in Division C3] A flame-retardant fibre comprises at least 60 wt. per cent of an aminotriazine-aldehyde resin cured to a degree of water-swelling (the weight of the fibres after 16 hours immersion in water at 20‹ C. and 5 minutes centrifuging at 1000 G, relative to the starting weight) below 2À0. The fibres are preferably obtained by spinning a solution of the resin precondensate into a heated atmosphere to remove solvent and cure the resin; the required degree of cure may be achieved immediately or by heat-treatment of the part-cured fibre. Preferably the fibre contains up to 40 wt. per cent of another filmforming polymer, e.g. modified cellulose, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide or polyvinyl alcohol (PVA), optionally with boric acid or a borate in amount 0À2-20 or 0À02-10 wt. per cent respectively of the PVA. In the examples fibres are spun from a commercial melamine-formaldehyde (MF) resin of M : F ratio 1 : 3 alone (Examples 2, 10) or mixed with polyethylene oxide (0À077%, Example 3) or PVA (0-50%, Example 4), or from a resin of M : F ratio about 1 : 6 prepared from melamine and formalin alone (Examples 1, 11, 12), or from one prepared from melamine and formalin in approx. 1 : 3 molar ratio in the presence of polyacrylamide (5%, Example 5) or PVA (20%) and boric acid or borax (Examples 6-9). The fibres are spun through orifices of 0À1-0À5 mm. diameter into nitrogen or air at 200-320‹ C. at 12-90 m./ min., 200-500 m./min. when boron is present.</p> |
