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
  • D06L4/26—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 combined with specific additives

Definitions

• the present invention relates to bleaching with chlorites; more particularly it concerns a process wherein bleaching with chlorites, in particular sodium chlorite, is carried out in the presence of amides, carbodiimides, amino acids or sulfamic acid compounds.
• amides there come into consideration, for example the amides of carboxylic acids or sulphonic acids or their substitution products; suitable representatives are, for example, the following compounds: formamide, acetamide, chloroacetamide, acetoacetic acid anilide, acetoacetic acid 2 chloroanilide, acetoacetic acid 2 anisidide, stearoyl amide, benzamide, benzosulfonic acid amide, 1 methyl benzene 2 sulfonic acid amide and Di-isopropyl carbodiimide may be mentioned for example as the carbodiimide.
• amino acids for carrying out the present invention there come into consideration in the first place amino carboxylic acids and amino sulfonic acids or their substitution products. Suitable representatives are, for example, amino acetic acid, methyl amino acetic acid, amino ethane sulfonic acid or methyl amino ethane sulfonic acid.
• sulfamic acid compounds thereare to be understood the compounds of the general formula HO-SOg-NXY wherein X and Y stand for hydrogen and/or aliphatic, aromatic or hydroaromatic hydrocarbon radicals which may be substituted, or wherein X and Y together with the nitrogen atom form a heterocyclic radical.
• hydrocarbon radicals the methyl, ethyl, phenyl or cyclohexyl radicals and as heterocyclic radicals the ethylene imine, pyrrolidine, piperidine or morpholine radicals may be mentioned as examples.
• the chlorite-containing bleaching bath is suitably rendered weakly alkaline or neutral before the commencement of bleaching.
• Materials which can be bleached by the process according to the present invention are in principle all materials which can be bleached with chlorites. It is remarkable that the process of the present invention leads to outstanding bleaching yields at temperatures as low as 70-80 C. in a. relatively short time, whereby practically no disagreeable odour is evolved from released chlorine dioxide gas. The risk of corrosion of the bleaching apparatus is also considerably reduced.
• Example 1 A desired calico containing husks is soaked with a solu- 3,173,749 Patented Mar. 16, 1965 tion which contains per litre 13 g. of sodium chlorite, 4 g. of a surface active paraffin sulfonate, 3 g. of sodium pyrophosphate and 4 g. of monochloroacetamide. The fabric is then squeezed until it shows 100% added weight and is maintained in a steam atmosphere at 80 C. for 2-3 hours. Finally the fabric is rinsed as usual; it is then outstandingly bleached and the cotton husks are completely removed.
• the bleaching time can be reduced to 1 hour if the temperature is raised to about C.
• one of the other aforementioned amides or carbodiimides can be used in approximately equal quantities.
• Example 2 A desized calico containing husks is soaked with a solution which contains per litre 13 g. of 80% sodium chlorite, 4 g. of a surface active paraffin sulfonate, 0.7 g. of monochloroacetamide and 1 g. ammonium sulfate. The fabric is then squeezed until it shows added weight, heated to 95-98 C. and kept at this temperature for 45 minutes. After the usual rinsing the fabric is outstandingly bleached and the cotton husks are completely removed.
• ammonium sulfate instead of ammonium sulfate, other ammonium salts, such as for instance ammonium phosphates may likewise be applied with advantage.
• Example 3 A desized calico containing husks is soaked with a solution which contains per litre 18 g. of 80% sodium chlorite, 4 g. of a surface active paraffin sulfonate, 5 g. of acid sodium pyrophosphate and 3 g. of amino acetic acid. The fabric is then squeezed to give 100% added weight and maintained in a steam atmosphere at 90-95 C. for 3-4 hours. Finally the fabric is rinsed as usual; it is then outstandingly bleached and the cotton husks are completely removed.
• Example 4 A cotton cord containing husks is soaked with a solution which contains per litre 18 g. of 80% sodium chlorite, 4 g. of a surface active paraflin sulfonate, 4 g. of acid sodium pyrophosphate and 1 g. of amino ethane sulphonic acid. The fabric is then squeezed to give 100% added weight and maintained in a steam atmosphere at 90-95 C. for 3-4 hours. Finally the fabric is rinsed as usual; it is then outstandingly bleached, the cotton husks being simultaneously removed.
• Example 5 A calico containing husks is soaked with a solution which contains per litre 18 g. of 80% sodium chlorite, 4 g. of a surface active paraffin sulfonate and 0.18 g. sulfamic acid. The fabric is then squeezed to give 100% added weight and maintained in a steam atmosphere at 90 C. for 1 hours. Finally the fabric is rinsed as usual; it is then outstandingly bleached, the cotton husks being completely removed.
• the bleaching time can be reduced to 40 minutes, if the temperature is raised to 100 C.

Landscapes

• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatment Of Fiber Materials (AREA)
• Detergent Compositions (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

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Cited By (2)

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Citations (8)

Family Cites Families (1)

• 0
  • BE BE569085D patent/BE569085A/xx unknown
  • NL NL107709D patent/NL107709C/xx active
• 1957
  • 1957-07-05 DE DEF23403A patent/DE1079582B/de active Pending
• 1958
  • 1958-07-02 US US746098A patent/US3173749A/en not_active Expired - Lifetime
  • 1958-07-02 GB GB21214/58A patent/GB855281A/en not_active Expired
  • 1958-07-04 FR FR1197570D patent/FR1197570A/fr not_active Expired

Patent Citations (8)

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