Teijin Limited

Setsuo Yamada

Fumiki Takabayashi

Yoshiyuki Sasaki

Norihiro Minemura

Togi Suzuki

Katsuyuki Kasaoka

Shinji Ohwaki

Kohichi Iohara

Shigenobu Kobayashi

Tadashi Konishi

Hironori Yamada

Kimihiro Ogawa

An improved copolyester fiber capable of being dyed with cationic dyes and having an excellent brightness, heat resistance and a satisfactory mechanical strength comprises a copolyester resin comprising a polymerization product of at least one aromatic dicarboxylic acid compound, at least one alkylene diol compound and at least one quaternary phosphonium organic sulfonate of the formula (I): ##STR1## wherein A=an aromatic or aliphatic radical, X.sup.1 =H or an ester-forming organic radical, X.sup.2 =an ester-forming organic radical, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 =an alkyl or aryl radical, n=1 or more, and having an [.eta.].sub.f of 0.5 or more, the copolyester fiber having a silk factor of 25 or more and exhibiting the number of scission of backbone chains of the copolyester molecules of 140.times.10.sup.23 or less per 10.sup.6 g of fiber when wet heat-treated in a solution of 0.4 g/l of acetic acid in distilled water at 130.degree. for 60 minutes.

Cationically-dyeable, thermally-resistant copolyester fiber comprising

An electroconductive core-sheath composite fiber comprising a core containing an electroconductive substance and a sheath formed of a fiber-forming polymer, which surrounds the core, wherein the core is completely covered with the sheath, the electric resistance of the surface of the fiber is lower than 10.sup.10 .OMEGA./cm, and the ratio of the electric resistance (.OMEGA./cm) of the surface to the internal electric resistance between the sections is lower than 10.sup.3.

Process for preparation of electroconductive composite fiber

Electroconductive composite fiber and process for preparation thereof

An antistatic polyester fabric having a water repellency, which comprises a woven or knitted fabric comprising a fiber of a modified polyester composed mainly of a polyester and blended with an antistatic agent, at least the surface of which is covered with a fluorine type water and oil-repellency agent.

Antistatic polyester fabric having water repellency

The light-resistance of aromatic polyamide fibers can be improved by heat-treating the aromatic polyamide fibers in the presence of urea and thiourea. The improvement in the light-resistance is enhanced by using aromatic polyamide fibers having an ultraviolet absorber incorporated therein.

Method for improving light-resistance of aromatic polyamide fibers

A fiber composed of a polyester having at least a part of terminals blocked with the residue of at least one specific metal sulfonate compound, where the amount of the blocked terminals is 1.3 to 4.0 mol % based on the dicarboxylic acid component of the polyester and the alkali dissolution speed constant is 3.3.times.10.sup.-9 to 6.5.times.10.sup.-9 cm/sec. This polyester has a good dyeability with a cationic dye and is excellent in the heat resistance and alkali resistance. The polyester fiber can be spun at a high speed or super high speed and can be false-twisted at a high temperature.

Modified polyester fiber and process for preparation thereof

Aromatic polyamide fibers or fabrics are dyed in a deep and brilliant color with good light fastness by impregnating the fibers or fabrics with (a) a cationic dye, (b) an aliphatic hydroxy compound having a boiling point of at least 180.degree.C., (c) at least one swelling agent selected from o-phenylphenol, p-phenylphenol, benzophenone, .alpha.-naphthol and .beta.-naphthol and (d) at least one of alkali metal salts or ammonium salts of inorganic or organic acids, the amount of the salt being 1 to 10% by weight based on the sum total of the amounts of (a), (b), (c) and (d), and then heat-treating the fibers or fabrics with steam.

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Ibaraki, Japan

Setsuo Yamada