| 摘要 |
Shaped articles of polyolefines, or containing polyolefines, are treated first in an acid bath containing an alkali metal bichromate, and then in an acid bath containing a reducing agent, the temperature of each bath being at least 80 DEG C. In the treatment of polyethylene, the temperature of each bath is desirably from 80 DEG -105 DEG C. and in the treatment of polypropylene, 80 DEG -120 DEG C. Preferably the first bath contains at least 25 g/l of alkali metal bichromate, and a condensation product of ethylene oxide and a long chain fatty alcohol. Treatment of articles in the first bath is preferably for a period of from 5-120 mins. The second bath may contain up to 50 g/l of a reducing agent, especially a sulphite or sodium formaldehyde sulphoxylate, and both baths may be acidified with sulphuric or hydrochloric acid. An intermediate washing step may be applied between treatment in the first and second baths. Articles so treated, which may include films, sheets, profiled articles and textile materials in the form of filaments, tows, fibres, yarns, fabrics and made-up garments contain a small proportion of trivalent chromium, and show an enhanced affinity for plastosoluble dyes, basic dyes and metalliferous acid dyes.ALSO:The affinity for dyestuffs of shaped articles of polyolefines, or containing polyolefines, is enhanced by treating them first in an acid bath containing an alkali metal bichromate, and then in an acid bath containing a reducing agent, the temperature of each bath being at least 80 DEG C. In the treatment of polyethylene, the temperature of each bath is desirably from 80 DEG -105 DEG C., and in the treatment of polypropylene, 80 DEG -120 DEG C. Preferably the first bath contains at least 25 g/l of alkali metal bichromate, and a condensation product of ethylene oxide and a long chain sulphonated fatty alcohol. Treatment of articles in the first bath is preferably for a period of from 5-120 mins. The second bath may contain up to 50 g/l of a reducing agent, especially a sulphite or sodium formaldehyde sulphoxylate, and both baths may be acidified with sulphuric or hydrochloric acid. An intermediate washing step may be applied between treatment in the first and second baths. Articles so treated, which may include films, sheets, profiled articles and textile materials in the form of filaments, tows, fibres, yarns, fabrics and made-up garments contain a small proportion of trivalent chromium, and show an enhanced affinity for plastosoluble dyes, basic dyes and metalliferous acid dyes.
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