ポリビニルアルコール系合成繊維に関する研究

第13報 ポリビニルアルコール精製時の残存硫酸の影響

抄録

Polyvinyl alcohol used in dry spinning is washed by water and purified. The purpose of washing is the removal of the impurities in P. V. A. powder but the effect of washing by dilute acid solution, on the protection of colouring of the heat-treated fiber is remarkable, according to the Suyama' s papers.
Then, the relation between the acid (sulfuric acid) parts added on the P. V. A. spinning solution and heat stability of obtained fiber was investigated upon the conditions of heat-treatment process. (I) and of end use requirement (II).
It was understood that the optimum acid parts upon the condition (I) differed from that upon the condition (II), condition (I); 0.025% (on the weight of P. V. A. ), condition (II); 0.005% (on the weight of P. V. A, )
The exposure to air at 165°C for 10 hrs, in case of the high content of acid, caused the increase of carbonylgroups in P. V. A. and the insolubilization of heat-treated fiber. Neverthless, in case of the low content of acid, these results could not be obtained. Futhermore, the exposure to inactive gas (N₂ gas) at 165°C, for 10 hrs does not cause the increase of carbonyl groups in P. V. A. and the insolubilization of heat-treated fiber, in both cases of the high content of-acid and the low.