Seitetsu Kagaku Co., Ltd.

Tohru Okabe

Saburo Hayashi

Kazuyoshi Okamoto

Shigeaki Mizutani

Teizo Isono

Mochifumi Mizutani

Mitsuji Adachi

Syohiti Okada

Toshio Osada

A tanning process comprising pickling a hide which has previously subjected to beamhouse works such as depilation if necessary, decalcification and beating, in the presence of urotropin and at least one tanning improver selected from chromium and aluminum salts as well as from phenolic compounds, organic compounds containing nitrogen and sulphur or halogen atoms, organic carboxylic acids, organotin compounds, copper compounds and arsenic compounds.

Tanning process and tanning compositions

By subjecting a hide which has completed beamhouse work to a pickling treatment in the presence of urotropin (hexamethylenetetramine) and then to a chrome-tanning treatment, pH control of chrome-tanning bath becomes simpler and easier, the combination between hide and basic chrome complex increases, and the amount of residual chromium in the waste water can be minimized. Further, by treating the formed leather which has completed tanning treatment with ammonia or ammonium salt of weak acid in the chrome bath after use, the workability in the finishing steps improves, quality of the leather additionally improves, and the chromium content of the residual solution can be made nearly zero.

Tanning method

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Hyogo, Japan

Tohru Okabe