Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06L—DRY-CLEANING, WASHING OR BLEACHING FIBRES, FILAMENTS, THREADS, YARNS, FABRICS, FEATHERS OR MADE-UP FIBROUS GOODS; BLEACHING LEATHER OR FURS
  • D06L4/00—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs
  • D06L4/10—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen
  • D06L4/12—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen combined with specific additives

Definitions

• the raw textile goods are bleached in order to prepare them for dyeing or for finishing. So far, it has been common to use bleaching agents such as hydrogen peroxide, sodium hypochlorite or sodium chlorite.
• hypochlorites in bleaching processes results in organohalogen compounds which can be harmful to health. This leads to an increasing omission of this bleaching agent.
• Sodium chlorite bleaching carried out in the acidic pH range leads to the formation of chlorine dioxide, which is harmful to health and represents an unpleasant smell.
• this bleach can only be used on selected textile machines consisting of special materials.
• hydrogen peroxide can be activated in other ways, e.g. B. by chemical conversion of the hydrogen peroxide to organic and inorganic peracids.
• G. Rösch, Deutsche Textiltechnik 10 (1960), No. 4, pages 191-195 discloses the use of peracetic acid in textile bleaching.
• Peracetic acid is flammable. The concentrated solution, which has a pungent odor, etches and burns the skin.
• the main disadvantage of peracetic acid is its high explosiveness. If acetic anhydride is used for the production, diacetyl peroxide can form as a by-product under unfavorable conditions, which also tends to decompose spontaneously. This behavior may be the reason why peracetic acid as a bleaching agent has not had the expected success.
• those compounds which have a large number of reactive acyl groups such as tetraacetylethylenediamine (TAED) and tetraacetylglycoluril (TAGU), have proven particularly effective, with the smallest possible molecular weight.
• TAED tetraacetylethylenediamine
• TAGU tetraacetylglycoluril
• DE-OS-1 695 219 discloses the use of acylated glycolurils, in particular TAGU, as bleaching agents, especially when bleaching fibers of all kinds.
• EP-A-125 641 and US-A-4 544 503 disclose the use of acyloxybenzenesulfonic acid salts (AOBS) as activators for peroxide bleaching of fabrics and as dyeing aids in dyeing acrylic fibers.
• AOBS acyloxybenzenesulfonic acid salts
• EP-A-442 549 mentions the use of phthalimidoperoxycarboxylic acids as bleaching agents for fabrics and hard surfaces.
• the object of the invention is to provide a method which enables the safe use of aliphatic percarboxylic acids, in particular peracetic acid, as bleaching agents in textile bleaching and which does not have the disadvantages of the prior art, such as damage to the textile material to be bleached and insufficient bleaching power.
• Suitable bleach activators are carboxamides, carboxylic acid esters and sulfonic acid salts.
• Preferred uses are triacetylethanolamine (TAEA), tetraacetylethylenediamine (TAED), pentaacetylglycose (PAG), tetraacetylglucoluril (TAGU), 1,5-diacetyl-2,4-dioxohexahydrotriacin (DADHT), nonanoylbenzenesulfonate (NOBSulfonate) -sulfonylsulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) sulfonate (NOBS) (NOBS
• cellulose in particular untreated natural cellulose such as hemp, linen, jute, cotton, regenerated cellulose fibers such as rayon, viscose acetate, rayon, animal fibers such as wool and silk as well as chemical fibers such as polyamide, polyacrylonitrile or polyester fiber materials and fiber mixtures , e.g. B. those made of polyacrylonitrile cotton or polyester cotton.
• the textile material to be treated can be used in the various processing stages are present, e.g. B. the cellulose-containing material as loose material, flake, sliver, yarn, knitted fabric, woven or knitted fabric.
• the textile material is treated continuously or discontinuously in an aqueous liquor.
• the aqueous bleaching liquor contains hydrogen peroxide and, if appropriate, peroxide stabilizers, detergents and wetting agents, additives such as defoamers and solution improvers, buffer systems such as phosphate salts and citric acid and basic salts such as sodium hydrogen carbonate, disodium carbonate and / or sodium hydroxide.
• the pH value of the bleaching liquor is in a range from 5 to 13, preferably 7 to 9.
• the molar ratio between hydrogen peroxide and bleach activator depends on the molar ratio of hydrogen peroxide to the active carbonyl groups of the bleach activator, hydrogen peroxide being used in a molar excess.
• the molar ratio of hydrogen peroxide to bleach activator is 2-10: 1, preferably 2.2-3: 1.
• the molar ratio of hydrogen peroxide to bleach activator is 1.0 - 5: 1, preferably 1.1 - 1.5: 1.
• the bleaching liquor When using solid bleach activators, the bleaching liquor is usually prepared in a liquor preparation tank by combining the individual components and, after a sufficient dissolving or reaction time, is transferred to the bleaching apparatus or the impregnation curve.
• the dissolving or reaction time is usually one hour, preferably 20 to 30 minutes.
• the bleaching liquor can be produced in the liquor preparation container in the manner described above or can be metered directly into the bleaching apparatus or the impregnation skid together with the other liquid constituents of the bleaching liquor.
• the textile material is treated with the bleaching liquor in the bleaching apparatus or the impregnation curve. Treatment with bleaching liquor is usually carried out at continuous process by impregnation, i.e.
• the textile raw material is either stored cold over a period of 0.5 to 24 hours, usually at room temperature, or heated to temperatures of 95 to 102 ° C. in atmospheric steamers with steam. The residence times at this temperature are 1 minute to 2 hours.
• Another bleaching process usually follows the bleaching with bleach activators, e.g. B. the alkaline peroxide bleaching. It has been shown that it is precisely through the combination of activator bleach with alkaline peroxide bleaching that good whiteness levels of the textile material are obtained.
• the textile material is washed or passed to a further pre-treatment stage such as impregnation.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Detergent Compositions (AREA)
• Coloring (AREA)

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Cited By (8)

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Citations (5)

• 1993
  • 1993-08-18 EP EP93113208A patent/EP0584710A3/fr not_active Withdrawn
  • 1993-08-19 JP JP5205282A patent/JPH06184926A/ja not_active Withdrawn

Patent Citations (5)

Non-Patent Citations (1)

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