Process to improve resistance to stains on yarns and derived products
AssigneeN.V. Denderland-Martin
InventorArmand de Lathauwer
Life of this patent
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Abstract
The invention consists of a process to improve the resistance to stains on yarns, on the basis of wool, silk, polyamide, polyacrilonitrile, natural and artificial cellulosic fibres and in general, all other synthetical fibres which can be dyed. According to the invention the yarns are treated during the dyeing process with an aqueous solution containing up to 5% tannic acid in acid medium. It is economically advisable to add a stabiliser to the solution to avoid oxidation of the solution and the fibres, and possibly a wetting agent. Preferably the treatment is made during the dyeing procedure, before, during or after the effective dyeing step.
Claims18
Method for producing a stain resistant substrate with the aid of a stain resistance improving agent, said method comprising:
- (A) providing a substrate containing polyamide fiber,
- (B) contacting said substrate with an acidic aqueous solution having a pH of up to about 6 and containing a tannic acid stain resistance improving agent in a concentration of 5 to 50 g/l,
- (C) bringing about such contact between said substrate and said at least one tannic acid prior to, during or after application of dye to the substrate,
- (D) the dyeing of said substrate taking place or having taken place at a temperature up to about 90.degree. C.,
- (E) drying the substrate with said tannic acid stain resistance improving agent thereon, and
- (F) recovering a dried, permanently dyed polyamide fiber-containing substrate wherein
- (1) the tannic acid stain resistance improving agent consists of at least one tannic acid, and
- (2) the polyamide fiber-containing substrate thus recovered is resistant to stains caused by any of the members of the group consisting of anionic dye, cationic dye, disperse dye and metallocomplex dye, and also by oxidative bleaching agent.
Method for producing a stain resistant substrate with the aid of a stain resistance improving agent, said method comprising:
- (A) providing a substrate comprising natural and/or synthetic fiber and containing polyamide fiber,
- (B) contacting said substrate with an acidic aqueous solution having a pH of up to about 6 and containing a tannic acid stain resistance improving agent in a concentration of 5 to 50 g/l,
- (C) bringing about such contact between said substrate and said at least one tannic acid during a dyeing process which includes one or more steps in which the substrate is given its colored and finished characteristics,
- (D) in said dyeing process, permanently dyeing said substrate by application to the substrate of at least one dye selected from the group consisting of acid dye, metallocomplex dye, basic dye and disperse dye, the application of dye to the substrate taking place or having taken place at a temperature up to about 90.degree. C.,
- (E) drying the substrate with said tannic acid stain resistance improving agent thereon, and
- (F) recovering a dried, permanently dyed polyamide fiber-containing substrate wherein
- (1) the tannic acid stain resistance improving agent consists of at least one tannic acid, and
- (2) the polyamide fiber-containing substrate thus recovered is resistant to stains caused by any of the members of the group consisting of anionic dye, cationic dye, disperse dye and metallocomplex dye and also by oxidative bleaching agent.
Dependencies are inferred from the claim text.