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
  • D06L4/13—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which develop oxygen using inorganic agents
• • 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

• Textile fibers represent an essential bleaching good. These are divided into natural fibers and man-made fibers. With regard to their origin, the former fibers are divided into natural fibers of animal origin (wool, silk) and natural fibers of vegetable origin (cotton, flax). The so-called synthetic fibers represent a sub-group of chemical fibers. These include polyamide fibers, polyester fibers, polyacrylonitrile fibers and polyurethane fibers.
• DE-OS-2 249 062 relates to the sheet metal of cellulose-containing textiles, for example cotton / polyester, by means of a bleaching agent consisting of an aqueous hydrogen peroxide solution, an alkali metal hydroxide, an alkali metal borate and an organic complexing agent.
• the bleaching agent preferably contains the equivalent of 0.2 to 1.8 percent by weight of 100 percent hydrogen peroxide, based on the textile material, and preferably has a pH of 9.5 to 11.5.
• the textile material is preferably impregnated with 50 to 125 percent by weight, based on the textile material.
• DE-OS-2 022 929 mentions a process for bleaching textile materials, in particular polyester / cotton textile materials, in which an emulsion or suspension of a bleaching agent, e.g. applying the emulsion of an aqueous hydrogen peroxide solution in a hydrocarbon or halogenated hydrocarbon solvent, largely removing the solvent from the textile material and then washing the textile material.
• a bleaching agent e.g. applying the emulsion of an aqueous hydrogen peroxide solution in a hydrocarbon or halogenated hydrocarbon solvent, largely removing the solvent from the textile material and then washing the textile material.
• US-A-3 649 164 describes a process for bleaching cellulosic textiles, e.g. Polyester / cotton textiles, with the aid of an aqueous alkaline hydrogen peroxide solution, which generally has a content of 0.5 to 1.5% hydrogen peroxide, based on the weight of the textile material, 0.05 to 0.5% of a water-soluble peroxidiphosphate, based on the weight of the textile material and a pH of 9 to 14.
• the textile material is pretreated with a bleaching solution at 140 to 160 ° F and then the fabric soaked with bleaching solution is heated to the boiling point of the bleaching solution.
• the bleaching processes described above all relate to the sheet metal of so-called polyester blended fabrics.
• DE-OS-3 002 726 describes a process for sheet metal fiber material with hydrogen peroxide, in which a fiber material is bleached with hydrogen peroxide in a weakly acidic medium at a pH of 5 to 7, then the bleaching system is mixed with an alkaline bleaching agent, thereby sets a pH of 8.5 to 11 and continues the bleaching with hydrogen peroxide in a weakly basic medium.
• the fiber material to be bleached includes, for example, natural, synthetic or semi-synthetic fibers. The examples listed show the use of the process for bleaching cotton, wool / cotton blend and polyester / cotton blend.
• bleaching with hydrogen peroxide in the weakly acidic pH range of 5 to 7 a whiteness is achieved which is achieved by bleaching with sodium chlorite alone.
• simple bleaching with hydrogen peroxide in a weakly acidic medium is said to be impractical.
• the bleaching agent hydrogen peroxide is considered to be of limited use with regard to the use in synthetic fibers, but a sufficient bleaching effect is not achieved (cf. Ullmanns Encyklopadie der Technische Chemie, 4th edition, volume 23, page 25, 1984). Only sodium chlorite is considered suitable for bleaching polyester, since other bleaching agents are not intended to produce a sufficient whitening effect (see BASF Handbook, Volume 363d, 8/74, page 81; K. Lindner, Tenside-Textile Aid Detergent Raw Materials III, page 2749 , 1971).
• synthetic fibers for example made of polyester, can also be sufficiently bleached with a bleaching solution containing an aqueous hydrogen peroxide solution. It is even more surprising that an improved bleaching effect can be achieved by adding polyphosphates in such a bleaching solution.
• the invention thus relates to a process for sheet metal of synthetic fibers with hydrogen peroxide, which is characterized in that the synthetic fiber with a bleaching solution containing hydrogen peroxide at a pH value of the bleaching solution of 3 to 7 and a temperature of the bleaching solution between 100 and 135 ° C. bleaches.
• polyester fibers are fibers made of polyester, polyamide, polyurethane and so-called acetate fibers.
• Polyester fibers are preferably used. It has been shown that not only conventional polyester fibers, but also special polyester fibers such as flame-retardant polyester fibers (see Chemistry for Textile Industry, 43-95, pages 65-68, 1993) and microfibers made of polyester can be bleached excellently.
• the bleaching solution is usually used in the form of an aqueous hydrogen peroxide solution. Although theoretically hydrogen peroxide solutions of any concentration can be used to prepare the bleaching solution, hydrogen peroxide solutions with less than 65 percent by weight are preferred for safety reasons. Those with 20 to 35 weight percent are generally preferred. For example, the concentration of 35 percent aqueous hydrogen peroxide is preferably 1.0 to 20 ml / l bleaching solution. Higher amounts of hydrogen peroxide are possible, but have no significant advantages.
• polyphosphates are preferably compounds of the formula Me n + 2 P n O 3n + 1 and Me n P n O 3n , where Me is an alkali metal ion, alkaline earth metal ion or ammonium ion and n is a number between 1 and 6.
• Me preferably means an alkali metal ion, especially sodium ion.
• Examples of such polyphosphates are compounds of the formula Na5P3O10 and Na6P6O18. Particularly with regard to these polyphosphates, particularly high bleaching effects are achieved.
• the bleaching solution usually contains 0.5 to 10 g / l, preferably 2 to 3 g / l, of polyphosphate.
• the bleaching solution according to the invention usually contains other suitable components. These include stabilizers that prevent the decomposition of hydrogen peroxide and any existing catalysts that promote this decomposition make them ineffective. Common stabilizers are alkaline earth metal salts. Magnesium silicate is of particular importance for the alkaline earth metal salts. Soluble magnesium or calcium salts, such as magnesium sulfate or calcium chloride, are also suitable. Preferably the bleach solution contains less than 0.5 % By weight, in particular less than 0.3% by weight, of the alkaline earth metal salt.
• the bleaching solution according to the invention optionally contains an organic complexing agent, for example an aminocarboxylic acid or its alkali metal salt or ammonium salt.
• the amino carboxylic acid preferably contains more than one amino group, at least one amino group should be substituted with 2 carboxylic acid groups, in particular an acetic acid or a substituted acetic acid group.
• the preferred complexing agents are ethylenediaminetetraacetic acid, N- (2-hydroxyethyl) ethylenediamine-triacetic acid, diethylenetriaminepentaacetic acid, triethylenetetramine-hexaacetic acid or one of these compounds in which one or more acetic acid group (s) have been replaced by a (2-hydroxyphenyl) acetic acid.
• Diethylenetriamine-pentaacetic acid or its alkali metal salt is preferred as the complexing agent.
• suitable complexing agents are suitable carboxylic acids, for example gluconic acid and suitable phosphonic acids or their alkali metal salts or ammonium salts, as indicated in Chwala-Anger, Handbuch der Textilosstoff, pp. 1003-1008, 1972.
• the complexing agent content of the bleaching solution is usually 0.1-5 g / l, preferably 0.2-1 g / l.
• the amount of complexing agent depends on the concentration of the hydrogen peroxide-decomposing metals, or on the purity of the water and on the quality of the synthetic fiber.
• 0.1 to 1 g / l of one or more bleaching aids such as protein degradation products or organic phosphates, in particular alkyl and alkylaryl phosphate esters, can also be added to the bleaching solution according to the invention.
• phosphate esters are alkyl and alkylaryl esters of poly (ethyleneoxy) phosphates.
• surface-active agents preferably a foam-free wetting agent
• surface-active agents can be added to the bleaching solution according to the invention, in order to facilitate washing of the synthetic fiber following the sheet metal.
• Anionic or nonionic surfactants can be used be used.
• suitable compounds are the condensates of alkylphenols, for example nonylphenol with ethylene oxide, salts of alkylarylsulfonic acids, for example the amine salts of dodecylbenzenesulfonic acid and long-chain alkyl sulfates.
• the concentration of the surfactant is usually 0.5 to 3 g / l, preferably 1 to 2 g / l.
• Optical brighteners can also be added to the bleaching solution.
• the amount added is generally 0.1-5 g / l bleaching solution. This achieves optimal white effects in a one-step bleaching and lightening process. Compared to the previous bleaching processes with sodium chlorite, there is no longer any requirement for a chlorite-stable optical brightener.
• alkali metal carbonates e.g. Sodium carbonate
• the bleaching solution has a weakly acidic to neutral pH, preferably a pH in the range from 3.0-7.0, in particular in the range from 5.0-7.0.
• the pH value required for maximum bleaching action depends e.g. on the type and quality of the textile goods and can e.g. by changing the acid concentration, e.g. by adding acetic acid.
• the liquor ratio is generally 1: 3 to 1:40, preferably 1:10 to 1:20.
• the synthetic fibers are bleached in the so-called high temperature range (HT) at a temperature in the range from 100 to 135 ° C., preferably in the range from 120 to 130 ° C.
• the vapor pressure required is preferably 1 to 3.5 atm., In particular 2 to 3 atm.
• the time which is necessary at a certain temperature to achieve a certain bleaching effect depends on the temperature: at 100 ° C preferably 80 to 120 minutes and at 135 ° C preferably 10 to 30 minutes. With regard to the entire temperature range, the treatment time is 10 to 120 minutes.
• the bleached fabric is preferably washed neutral with hot water.
• the process according to the invention is usually carried out in conventional HT bleaching apparatus.
• the process according to the invention proceeds in a single step and requires only one bleaching device.
• conventional bleaching agents such as sodium chlorite ensures that the environment is kept clean to a high degree.
• chlorite-resistant brightener there is also no requirement for a chlorite-resistant brightener.
• the machines and equipment used are not exposed to the corrosive conditions that occur in this process.
• the degrees of whiteness achieved are determined according to Ganz (see R. Griesser, Rev. Prog. Coloration, Vol. 11, p.25, 1981).
• a textile fabric made of polyester is bleached with a bleaching solution containing 5 ml / l of 35% strength by weight aqueous hydrogen peroxide solution with a pH of 6-7 and a temperature of 130 ° C. over a period of 45 minutes.
• the fleet ratio is 1:20.
• a whiteness of 80 is achieved.
• a textile fabric made of polyester is bleached with 5 ml / l of 35% by weight aqueous hydrogen peroxide solution and 3 g / l of sodium polyphosphate, with a pH of 6-7 (adjusted with acetic acid) and a temperature of 130 ° C bleached over a period of 45 minutes.
• the fleet ratio is 1:20.
• a whiteness of 85 is achieved.
• a textile fabric made of polyester is bleached with a solution containing 5 ml / l of 35% by weight aqueous hydrogen peroxide solution, 3 g / l of sodium polyphosphate and 0.5 g / l of an optical brightener (® Hostalux ERE) with a pH of 6-7 (adjusted with acetic acid) and a temperature of 130 ° C bleached over a period of 45 minutes.
• the fleet ratio is 1:20.
• a whiteness of 215 is achieved.
• a textile fabric made of polyester is bleached with a bleaching solution containing 5 ml / l of 35% by weight aqueous hydrogen peroxide solution in a weakly acidic medium with a pH of 6.9 at a temperature of 90 ° C Bleached for 60 minutes.
• An alkaline agent aqueous sodium hydroxide solution containing sodium silicate
• the fleet ratio is 1:10.
• a whiteness of 81 is achieved.
• a textile fabric made of polyester is bleached over a period of time with a bleaching solution containing 1.5 g / l of sodium chlorite, 1.0 g / l of a bleaching aid and 0.5 g / l of a wetting agent (®Hostapal FA) bleached by 45 minutes.
• the fleet ratio is 1:20.
• a whiteness of 86 is achieved.

Landscapes

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

Applications Claiming Priority (4)

Publications (1)

Family

ID=25934610

Family Applications (1)

Country Status (8)

Cited By (1)

• 1995
  • 1995-03-01 EP EP95102883A patent/EP0671499A2/de not_active Withdrawn
  • 1995-03-09 JP JP7050061A patent/JPH0849164A/ja not_active Withdrawn
  • 1995-03-09 FI FI951100A patent/FI951100A/fi unknown
  • 1995-03-09 CZ CZ95611A patent/CZ61195A3/cs unknown
  • 1995-03-10 SI SI9500079A patent/SI9500079A/sl unknown
  • 1995-03-10 CA CA002144371A patent/CA2144371A1/en not_active Abandoned
  • 1995-03-10 PL PL95307628A patent/PL307628A1/xx unknown
  • 1995-03-10 NO NO950937A patent/NO950937L/no unknown

Also Published As

Similar Documents

Legal Events