Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P3/00—Special processes of dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form, classified according to the material treated
  • D06P3/02—Material containing basic nitrogen
  • D06P3/04—Material containing basic nitrogen containing amide groups
  • D06P3/32—Material containing basic nitrogen containing amide groups leather skins
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P1/00—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed
  • D06P1/44—General processes of dyeing or printing textiles, or general processes of dyeing leather, furs, or solid macromolecular substances in any form, classified according to the dyes, pigments, or auxiliary substances employed using insoluble pigments or auxiliary substances, e.g. binders
  • D06P1/673—Inorganic compounds
  • D06P1/67333—Salts or hydroxides
  • D06P1/67341—Salts or hydroxides of elements different from the alkaline or alkaline-earth metals or with anions containing those elements
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06P—DYEING OR PRINTING TEXTILES; DYEING LEATHER, FURS OR SOLID MACROMOLECULAR SUBSTANCES IN ANY FORM
  • D06P5/00—Other features in dyeing or printing textiles, or dyeing leather, furs, or solid macromolecular substances in any form
  • D06P5/02—After-treatment
  • D06P5/10—After-treatment with compounds containing metal

Definitions

• the present invention relates to a method for dyeing leather while improving the light fastness of the dyed leather.
• leather is mainly dyed with acidic, substantive or metal complex dyes in an aqueous medium. Occasionally, basic dyes or selected sulfur dyes are used for special types of leather. With so-called aniline leathers, i.e. If the leather is weak or not finished at all, the lightfastness of the dyeing is a decisive criterion for the quality of the finished leather. This is especially true for furniture and clothing leather, which as a finished finished product is almost always exposed to the effects of light. This affects grain leather and suede equally.
• the particularly lightfast metal complex dyes are still predominantly used for coloring high-quality aniline leather.
• the production of these dyes is described in numerous patents, both 1: 1 and 1: 2 metal complex dyes being suitable for leather dyeing. Salts of Cr, Fe, Co, Ni and Cu are particularly suitable for the metallization. With such dyes, whose lightfastness values are on average 4 to 5, the lightfastness of the dye-leather system can also be significantly improved.
• the invention was therefore based on the object of developing a process with which, using the usually inexpensive anionic azo dyes used for leather dyeing, by modifying the conventional ones Dyeing process a significant improvement in the lightfastness of the leather dyeings can be obtained.
• This object is achieved in that the leather to be dyed is treated with copper salts before, during or after the dyeing process. It must be regarded as surprising that during the dyeing process copper complexes of the anionic leather dyes with increased lightfastness appear under the very mild conditions for dyeing leather compared to textile dyeing, and above all also with a view to the fact that the leather itself can accumulate copper salts can form.
• the aftertreatment of dyeings on textile material for example wool or cellulose fibers
• water-soluble copper salts is also known (see IG guide for dyeing protein fibers, 1932 and Ullmann, 3rd edition, 7th volume, pp. 17 ff.).
• special copper-based dyes such as coprantine, cuprophenyl, benzocuprol or Cuprofix dyes must be used.
• the coppering takes place under conditions which are out of the question for leather dyeing, for example one to several hours of treatment of the material to be dyed at 70 to 100 * C.
• this is a pure aftertreatment of the dyeings, while in the process according to the invention the coppering can be done before, during and after coloring.
• the sulfate, chloride, nitrate, acetate, formate or the corresponding copper tetramine salts can be used as copper salts in the process according to the invention.
• the addition can take place at pH values of 2-9, preferably at pH 4.5-6, the amounts of the copper salts being between 0.01 and 3 percent, preferably 0.1-0.5 percent, based on the weight of the leather to be dyed.
• the copper salt is preferably added before or during the addition of dye, but it can also be added after the actual dyeing process. It is also possible to add copper salt and dye to the dyeing liquor and to add the leather to be dyed only when the copper-dye complex has already formed.
• the temperature of the dyebath can be 20-70'C, preferably 40-50 . C.
• additions of ammonia or the anionic and nonionic dyeing auxiliaries and surfactants customary in leather dyeing can be expedient.
• Suitable dyes for the process are especially azo dyes with 0.0'-dioxy-azo, 0-oxy-O I- carboxy-azo. or 0-oxy-azo groupings, where both 1,1- and 1,2-copper complexes can arise. It should be noted that the complex formation does not proceed equally easily with all dyes with the groups described above. Since the hue does not change practically with the coppering in most of the dye types mentioned, the main criterion for complex formation remains the testing of the lightfastness of the coloring.
• oxidizing agents such as hydrogen peroxide, alkali peroxides, urea peroxide, perborates, percarbonates, persulfates, peracids, alkali chlorites, perchlorates, acyl peroxides or chromic acid in amounts of 30-300 percent, preferably 100-200 percent of the amount of copper salt used, complex formation can be achieved.
• complex formation can be achieved.
• the method described according to the invention can be applied to all common types of leather, such as pure chrome leather, post-chrome-plated vegetable leather, vegetable-synthetically translated chrome leather or even leather with special tanning based on aluminum salts, aldehydes and / or synthetic white tanning agents.
• Two pieces of an intermediate dried chrome split leather are dyed as follows. The percentages relate to the dry weight of the leather.
• the light fastness according to IUF 402 is 4-5 for coloring A and 3 for coloring B.
• Two pieces of an intermediate dried chrome split leather are dyed as follows. The percentages relate to the dry weight of the leather.
• Two pieces of a chrome tanned, folded 1.2 mm thick cowhide leather are worked as follows. The percentages relate to the fold weight of the leather.
• the lightfastness of color A is 4, that of color B 2-3.
• the table below shows some examples of dyes which, when coppering during the dyeing process, result in a significant improvement in the lightfastness values.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Coloring (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6249918

Family Applications (1)

Country Status (6)

Cited By (1)

Citations (4)

• 1984
  • 1984-11-09 DE DE19843440989 patent/DE3440989A1/de not_active Withdrawn
• 1985
  • 1985-10-31 EP EP85113858A patent/EP0183078A1/fr not_active Withdrawn
  • 1985-11-07 ES ES548616A patent/ES8702545A1/es not_active Expired
  • 1985-11-08 KR KR1019850008347A patent/KR860004203A/ko not_active Application Discontinuation
  • 1985-11-08 BR BR8505628A patent/BR8505628A/pt unknown
  • 1985-11-08 JP JP60249111A patent/JPS61113885A/ja active Pending

Patent Citations (4)

Non-Patent Citations (2)

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