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
  • D06L4/20—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which contain halogen
  • D06L4/22—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which contain halogen using inorganic agents
  • D06L4/24—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which contain halogen using inorganic agents using chlorites or chlorine dioxide

Definitions

• This: invention relates to the treatment of cellulosic textiles. 'It relates more particularly tofimprovements in the treatment of such mate'- rialswitha chlorite, sodium chlorite'and calcium ch'lorite, for instance.
• Sodium hypochlorite has been found to be a particularly desirable agent for activating the chlo'r'ite and accelerating the bleaching of the textile; Sodium hypochlorite alone has previously been used-in the bleaching of cellulosic textiles, but when so used has been found to attackthe' cellulosic fibers with a re'sultantten dering of the textile material. It has been found, however, that considerable proportions of sodium hypochlorite may be used in conjunction with sodium chlorite, for instance, without deleteriously affecting the textile.
• cellulosic textiles have been satisfactorily bleached by treatment with an aqueous solution, of sodium 'hypochlorite and sodium chlorite, in which the ratio of hypochlorite to chlorite, on the basis of available chlorine, was about l /2:1.
• Such operations have been carried out successfully by treating th textile in an aqueous bath of the hypochlorite-chlorite solution at temperatures 1 ranging upwardly from about room temperature to somewhat less than 100 F.
• My present invention provides means'whereby cellulosic textiles may be treated with an aqueous solution of chlorite and hy-pochlorite at temperatures materially greater than heretofore found practical in 'such treatment, at a greatly No Drawing. Application May s, 1945, 4
• the process of any present invention comprises the impregnation of thetextile to be treated with an aqueous solutionof the chlorite and hypochlorite, and thereafter steaming the impregnated textile in the absence 'of surplus solution.
• hypochlorite is not rapidly decomposed in'the presence of the chlorite, the evolution of chlorine dioxide is substantially inhibited, and the textile is rapidly bleachedwith out deleterious eflects.
• Impregnation of the textile with the solution may be accomplished by immersion, padding, spraying, or other procedure which assures reafsonably thorough wetting; Thereafter excess so ⁇ - lution, if any, is drained or squeezed r o ure particularly where good absorbency is desired.
• Prior to the treatment of thetextile with the By subjecting the unfinished textiletoa caustic steaming, washing in hot or cold water, and then steaming the textile whileii-mpregnated with'ran. aqueous solution of hypochlorite:andmhloritezand again washing, superior results have been obtained with respect to whitenessee pellent. and. uniform absorbency, susceptibility to dyeing end.
• the textile is washed and; preferably immediately,-iS- subjected to the second: stage; i. e., thehypochlorite-chlorite steaming operation.
• the textile may, in accordance with the broader aspect of this invention, as previously noted-be subjected to other conventional scouri-ng operations.-for --instance, kiering, but in order toeattainthe fullgbenefits of the present invention, the .:textile should be subjected to a caustic steaming and washing immediately preceding the herein described step of the process comprising the steaming, while impregnated with the hypochlorite-chlorite solution.
• the steaming of the textile while impregnated with the hypochlorite-chlorite solution may likewise-be carried out: inany conventional steamer. either .at full width or in-:rope :iormnin which the impregnated itextile'; :is. subjected to. the-e10.- vated temperature for a sufficient-period-toiaccomplish the desired extent oflbleaching.
• Thetime'factor may be varied by yaryinglthe rate at which the textile is -passed-.through- -the .steamingzone, that of the. above-described J- chute; for-instance, or. by'-.varying-;- the lengthiof the steaming zone.
• a satisfactory. bleach I i is usually obtained .in about z /e .to-nabout 1 hr.,- depending primarily upon the I temperature employed.
• the ratio of hypochlorite to chlorite and the available chlorine concentration and pH of the solution are also subject to considerable variation.
• the ratio of hypochlorite to chlorite may. with advantage, be varied Within the range of about 0.51:1 to about 4:1, based on available chlorine, the optimum ratio depending largely upon other operating conditions and the results desired. Rapid and satisfactory bleaching has generally been obtained where the available chlorine concentration of the impregnating solution is about 2.5 to 3 grams per liter.
• the pH of the solution should not be less than 7 and is desirably within the range of about 9 to 11.
• the textile may, if desired, be subjected to an intervening souring.
• the improvement which comprises effecting bleaching of the textile with said solution at a temperature in excess of 100 F. without appreciably diminishing activation of the chlorite by decomposition of the hypochlorite, said bleaching being effected by impregnating the textile with said solution and steaming the impregnated textile in the presence of only so much of the solution as is retained in the textile, for a period of time suflicient to effect the desired bleaching, the ratio of the hypochlorite to chlorite in the solution being within the range of about 0.5:1 to about 4:1.
• the im provement which comprises effecting bleaching of the textile with said solution at a temperature in excess of F. without appreciably diminishing activation of the chlorite by decomposition of the hypochlorite, said bleaching bein effected by impregnating the textile With said solution, heating the impregnated textile, in the presence of only so much of the solution as is retained in the textile, by contact with steam, and maintaining the textile at a temperature Within the range of about 100 F. to about 212 F. for a period of time sufficient to effect the desired bleaching.
• said bleaching being effected by heating the impregnated textile, in the presence of only so much of the chlorite-hypochlorite solution as is retained in the textile, by contact with steam, and maintaining the textile at a temperature within the range of about 100 F. to about 212 F. for a period of time sufiicient to eifect the desired bleaching.

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• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Detergent Compositions (AREA)
• Paper (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Treatment Of Fiber Materials (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24377799

Family Applications (1)

Country Status (4)

Cited By (7)

Families Citing this family (1)

Citations (11)

• 1945
  • 1945-05-16 US US594164A patent/US2521340A/en not_active Expired - Lifetime
• 1946
  • 1946-02-26 GB GB6008/46A patent/GB608547A/en not_active Expired
  • 1946-03-07 FR FR923449D patent/FR923449A/fr not_active Expired
• 1950
  • 1950-09-28 DE DES19701A patent/DE843393C/de not_active Expired

Patent Citations (11)

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