Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
  • D21C9/16—Bleaching ; Apparatus therefor with per compounds
• • 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 present invention relates to a method of stabilizing the active oxygen content of textile bleaching baths.
• the object of this invention to provide a chemical stabilizer which will regulate the decomposition of peroxide compounds in textile bleaching baths.
• Another object of this invention is to provide such a stabilizer which is unaffected by the presence of heavy metals or heavy metal compounds in the bleaching bath.
• Another object of this invention is to provide a stabilizer, the presence of which will not have a detrimental efiect on the materials .to be bleached.
• organic stabilizers which contain calcium or magnesium combined in organic salt formers oncomplexes
• the bleaching baths can also be adequately stabilized.
• the use of these organic stabilizers also entails disadvantages, in that their eiiectiveness is curtailed by the presence of small amounts of heavy metals or heavy metal compounds contained in the fibers. When these metals or compounds are present the decomposition of the peroxides is catalytically accelerated, and because of this a localized overbleaching of the fibers can readily occur which effects their value and use.
• the old type silicate stabilizers have been used mainly with concentrated and alkaline peroxide baths. As was noted above, however, these stabilizers have their drawbacks, in that they cause turbidity in the bath as the bath cools off and consequently the silicate may deposit on the fibers.
• the slow decomposition of the silicic acid ester avoids turbidity in the bath as well as a deposition of silicates on the fibers or textiles.
• alkoxysilanes can be used with excellent results as the silicic acid esters. These alkoxysilanes are soluble in water and exhibit excellent stabilizing charack teristics.
• Typical al'koxysilane's for example, are tetrakis- (2 methoxy ethoxy) silane, methyl-tris 2 methoxyethoxy) silane and dimethyl-bis (2-methoxy-ethoxy)- silane.
• the stabilizing effect of the silicic acid esters can be increased if, in addition, water soluble alkali metal salts or particularly water soluble alkaline earth metal salts, such as salts of magnesium or of calcium, are added to the bleaching baths.
• the treatment of the textiles and fibers in the presence of silicic acid esters is preferably conducted in an alkaline medium, for example, at a pH between 7.5 and 11.5.
• an alkaline medium for example, at a pH between 7.5 and 11.5.
• the usual buffering salts such as phosphates and the like, can be employed.
• the bleaching operation is COlldllCtedJfit temperatures over 60 C., preferably between C. and C.
• the usual chemical textile aids can be used in the bleaching bath according to the process of this invention, such as the sodium salt of dodecyl sulfate, oxyethylated fatty alcohols with 12 to 16 C-atorns or the condensation products of proteins with aliphatic acids.
• Solution I contained no other additives but solution II contained sodium silicate and solution III contained tetrakis-(Z-methoxy-ethoxy)- silane, each in such quantities that the SiO content of solutions 11 and HI each amounted to 0.334 g./liter. In all solutions the pH was adjusted to 9.0.
• the cotton fabric was rinsed and dried in the usual manner.
• the whiteness content of the treated cotton fabric was found to be 84% of the MgO reference plate of a Zeiss-Elrepho whiteness meter.
• the untreated cotton fabric had a whiteness content of 54% when similarly tested.
• Example 2 45 kg. of a fabric made of Nylon 6, which was-previously thermofixed at 182 C. and desized, was treated in a jigger for 2 hours at 100 C. with 300 liters of a bleaching bath containing After this treatment the fabric was twice rinsed with warm water and once with cold water and dried in the usual manner.
• the whiteness of the treated fabric was found to be 81% of the MgO reference plate of a Zeiss- Elrepho whiteness meter.
• the active oxygen content of the bleaching bath in the example which initially amounted to 1.5 g./liter was lowered to 0.33 g./liter due to the bleaching operation.
• the silicic acid esters according to the invention are hydrolysable when added to an alkaline reacting solution.
• a process for bleaching cellulose, wood pulp, natural and synthetic fibers in an aqueous medium containing a peroxidic bleaching compound the step which comprises incorporating an at least partially water soluble, hydrolyzable, silicic acid ester in the aqueous medium employed for such bleaching to maintain a quantity of silicic acid ester of 1 to 30 g. per liter in said aqueous medium.
• An aqueous bleaching bath containing a peroxidic bleaching compound and an efiective amount of an at least partially water soluble, hydrolyzable, silicic acid ester to act as a stabilizer for said peroxidic bleaching com pound.
• a bleaching bath as in claim 9 further comprising water soluble salts selected from the group consisting of alkali metal salts and alkaline earth metal salts.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Textile Engineering (AREA)
• Paper (AREA)
• Detergent Compositions (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7039567

Family Applications (1)

Country Status (6)

Cited By (9)

Families Citing this family (1)

Citations (4)

• 0
  • NL NL97796D patent/NL97796C/xx active
• 1958
  • 1958-05-29 DE DED28208A patent/DE1083221B/de active Pending
• 1959
  • 1959-05-19 GB GB17002/59A patent/GB890300A/en not_active Expired
  • 1959-05-23 FR FR795425A patent/FR1225313A/fr not_active Expired
  • 1959-05-28 US US816369A patent/US3003910A/en not_active Expired - Lifetime
  • 1959-10-01 CH CH7325059A patent/CH368463A/de unknown

Patent Citations (4)

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