Nitivy Co., Ltd.

Life Energy Industry Inc.

Fuji Lace Sangyo Co., Ltd.

Tadayoshi Utsumi

Mitsutaka Uzumaki

Masahiko Takashio

Toshio Sugihara

Marcos Masaki Komiya

Ichiro Nagashima

Akihisa Shirasaka

Siro Nakamura

Proposed is an electret fiber which is an insolubilized polyvinyl alcohol fiber containing 0.05 to 0.5% by weight of tourmaline particles having a particle diameter not exceeding 0.3 .mu.m. The electret fiber is effective for invigoration of human body by promoting blood circulation and also effective for decreasing the BOD value of sewage water by activating the bacteria in the activated sludge. The electret fiber is prepared by spinning a spinning solution of the polyvinyl alcohol containing the tourmaline particles into the form of a fiber which is then subjected to an insolubilization treatment by a heat treatment, formalization with formaldehyde or acetalization with glutaraldehyde.

Polyvinyl alcohol fiber containing tourmaline particles

Superfine fibers of polyvinyl alcohol type having a single fiber diameter of 0.1-1.0.mu. and a fineness of 0.8-80.times.10.sup.-4 d/f are baked in the presence of a dehydration catalyst so that the weight loss ratio of fibers falls under the range of about 5 to 40%. When ion-exchange radicals are introduced into the partially dehydrated fiber, superfine fibers with a high ion-exchange rate are obtained.

Process for preparing superfine ion-exchange fibers

A partially polyenized polyvinyl alcohol fiber is obtained by heating and dehydration polyvinyl alcohol type fibers at temperatures of about 80.degree. to 350.degree. C so that the dehydration weight loss falls within the range of about 5% to 40%. An ion-exchange radical is introduced into the partially polyenized polyvinyl alcohol fiber to obtain fibers with an ion-exchange capacity. The ion-exchange fiber thus obtained exhibits an exchange capacity comparable to ion-exchange resins and has practical properties as fibers, such as good chemical resistance and flexibility.

Partially polyenized polyvinyl alcohol fibers with ion-exchange capacity

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Fujieda, Japan

Tadayoshi Utsumi