Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3947—Liquid compositions
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3902—Organic or inorganic per-compounds combined with specific additives
  • C11D3/3905—Bleach activators or bleach catalysts
  • C11D3/3907—Organic compounds
  • C11D3/3917—Nitrogen-containing compounds
  • C11D3/3925—Nitriles; Isocyanates or quarternary ammonium nitriles
• • 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

• This invention relates to an aqueous bleach bath based on hydrogen peroxide with which bleaching may be carried out in an acid medium, particularly bleaching of cellulosic textile materials.
• the bleaching of cellulosic fibrous materials has hitherto been carried out with aqueous alkaline hydrogen peroxide solutions because alkaline hydrogen peroxide is notable for a particularly strong oxidizing action.
• the fabric is hydrophilic and shows excellent whiteness after a single bleaching step.
• sodium silicate or sodium-pyrophosphate is added to such bleach baths. These chemicals form undesirable deposits on parts of the machines, on the padding equipment or on the textile material being treated, particularly in continuous operation.
• Another disadvantage is that all types of cellulose may not be advantageously bleached under alkaline conditions, as alkalis frequently effect a change in the structure of cellulose.
• the problem has been tackled with the use of nitriles and it is stated in said application that the addition of nitriles greatly accelerates the liberation of oxygen.
• stabilizers such as sodium silicate, which is understandable from the fact that nitriles accelerate the liberation of oxygen from hydrogen peroxide.
• bleach baths based on hydrogen peroxide and organic cyanides and containing from 0.1 to 2.0% by weight of 100% hydrogen peroxide and from 0.05 to 1.2% by weight of an organic cyanide, based on the weight of the bath, and which have hydrogen ion concentrations corresponding to pH 4 to pH 7.
• Suitable cyanides for the bleach baths of the invention are any compounds or mixtures of compounds containing at least one cyano group.
• cyanides which are soluble in water or readily dispersible therein. Examples are cyanides of from 3 to 6 carbon atoms, particularly aliphatic cyanides of from 3 to 6 carbon atoms, these not only being particularly suitable for the bleach bathof the invention but also being readily available.
• the cyanides, which are also referred to below as nitriles may, for example, be aliphatic, aromatic or cycloaliphatic and they may contain hetero atoms.
• nitriles which boil above C. and which show no or only very little tendency to distil with steam.
• Specific examples are phthalonitrile, malonamidonitrile, propionitrile, butyronitrile, malononitrile, succinonitrile, adiponitrile, cyanamide, dicyanodiamide or mixtures thereof.
• the hydrogen peroxide may be used in any of the commercially available concentrations. Successful results have been obtained by adding hydrogen peroxide to the bleach bath of the invention such that the concentration of hydrogen peroxide in the bath is from 0.1 to 2.0% by weight and preferably from 0.2 to 1.0% by weight, equivalent to a concentration-of active oxygen in the bath of from 0.5 to 10.0 g./l. and preferably from 1 to 5 g./l.
• the organic cyanides are added in concentrations of from 0.05 to 1.2% and preferably from 0.1 to 0.7% based on the weight of the bath, the ratio of hydrogen peroxide to cyanide groups then being in the range 1:0.1 to 1:1 and preferably the range 1:0.15 to 1:05, without the activity of the bleach bath being substantially reduced.
• the bath containing the hydrogen peroxide and organic cyanide must have a hydrogen ion concentration equivalent to a pH of from 4 to 7 and preferably from 5 to 6.5.
• This hydrogen ion concentration is obtained by using the substances commonly employed for pH adjustments or by using bulfer mixtures, which also prevent a fall in pH during bleaching.
• Specific examples of such substances are alkali metal and ammonium carbonates, bicarbonates, carbamates, and hexamethylene tetramine, primary, secondary and tertiary alkali metal phosphates, polyphosphates and/or mixtures of said substances.
• Alkali metal formates or acetates, urea or formamide may be added to the baths and, other components commonly used in such baths may also be added, for example optical brighteners or surface active agents or mixtures thereof, particular examples being anionic and non-ionic wetting agents and detergents.
• the bleach bath is generally prepared at room temperature or slightly elevated temperatures of up to about 40 C. It is possible to use higher or lower temperatures but this usually has no added advantage.
• the peroxy carboximide appears to be relatively stable and to have a similar property to that exhibited by hydrogen peroxide systems stabilized by sodium silicate under alkaline conditions.
• the bath prepared in the manner indicated above may be heated to from 70 to 100 C., and the fibrous material to be bleached may be immersed in the bath before or after the desired temperature has been reached.
• the fibrous material may be impregnated with the bleaching liquor and then heated to the bleaching temperature in known manner, for example by steaming.
• high pressure steaming temperatures of for example up to 130 C. are obtainable.
• the liquor ratio may be from 1:1 to 50:1 depending on the bleaching process used.
• the treating time should be sufficient to effect bleaching.
• Bleaching is complete under the specified conditions over periods ranging from a few minutes, for example 1 to 5 minutes (high-pressure steaming) to 3 hours (pad-roll or J-box bleaching).
• Yet another alternative is to impregnate the fibrous material and heat it for a few seconds, for Example 5 to 15 seconds, at from about 100 to 130 C. and then leave it for a number of hours, for example up to 24 hours, in the cold impregnated state, by which method the cellulosic material often achieves even higher DP values.
• EXAMPLE 1 Desized and dried unbleached cotton cloth is impregnated with a solution of the composition:
• the pH of the liquor is 6.5.
• the material treated with this solution is padded to a wet pickup of 100% and steamed for 3 hours at from to C.
• the material is then rinsed with warm water and then with cold water.
• the bleached material is completely free from husks and has a whiteness of from 82 to 85% reflectance (as measured with an Elrephofotometer using filter R 46 T) depending on the quality of cotton used. Of particular note is the fact that the treated material is extremely hydrophilic.
• a process for bleaching cellulosic textile material which comprises treating said material in an aqueous acidic bleach bath at a liquid ratio of from 1:1 to 50:1 and at a temperature of from 70 to 130 C. for a period sufficiently long to effect bleaching of said material, said bleach bath consisting essentially of water from 0.1 to 2% by Weight of 100% hydrogen peroxide and from 0.05 to 1.2% by Weight of an organic cyanide selected from the class consisting of cyanamide, dicyanodiamide, ben zonitrile, phthalonitrile and aliphatic nitriles of 3 to 6 carbon atoms, all percentages being based on the weight of the bath, and said bath having a hydrogen ion concentration equivalent to a pH of between 4 and 7.
• organic cyanide is a compound selected from the group consisting of phthalonitrile, malonamidonitrile, propionitrile, butyronitrile, malononitrile, succinonitrile, adiponitrile, cyanarni de, dicyanodiamide and mixtures thereof.
• organic cyanide is a compound selected from the group consisting of dicyanodiamide, cyanamide and mixtures thereof.
• an additive selected from the group consisting of alkali metal and ammonium carbonates, bicarbonates, carbamates, hexamethylene tetramide, primary, secondary and tertiary alkali metal phosphates, polyphosphates and mixtures thereof for adjustment of the pH.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Inorganic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Textile Engineering (AREA)
• Detergent Compositions (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=5783406

Family Applications (1)

Country Status (6)

Cited By (19)

Families Citing this family (4)

• 1970
  • 1970-09-25 DE DE2047289A patent/DE2047289B2/de not_active Ceased
• 1971
  • 1971-08-12 CH CH1187771D patent/CH1187771A4/xx unknown
  • 1971-08-12 CH CH1187771A patent/CH539721A/de unknown
  • 1971-08-31 FR FR7131457A patent/FR2107961B1/fr not_active Expired
  • 1971-09-20 US US00182158A patent/US3756774A/en not_active Expired - Lifetime
  • 1971-09-22 IT IT53027/71A patent/IT939451B/it active
  • 1971-09-24 AT AT829771A patent/AT327148B/de not_active IP Right Cessation

Also Published As

Similar Documents