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
  • D06L1/00—Dry-cleaning or washing fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods
  • D06L1/12—Dry-cleaning or washing fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods using aqueous solvents
  • D06L1/14—De-sizing
• • 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
• • 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
  • D06L4/23—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 hypohalogenites
• • 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
• • 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
  • D06L4/27—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs using agents which contain halogen using organic 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
  • D06L4/70—Multi-step processes

Definitions

• This invention relates to the bleaching of unbleached cellulose.
• cellulose textile materials especially those that contain synthetic fibers, must not only bleach the cellulose, but must also remove any cotton husks any size which may be present, increase the hydrophilicity of the fiber, and not lead to any substantial degradation of the cellulose mole- "cules.
• Certain enzymatic materials such as amylases, are known effective desizing agents for textile materials, but have no bleaching effect, and do not remove cotton husks, nor improve the hydrophilicity of the fibers.
• conventional bleaching agents such as hydrogen peroxide and sodium chlorite have a good bleaching effect, but do not remove size and, in many cases, do not improve the hydrophilicity of the fibers.
• the hydrophilicity can be improved by boiling with highly concentrated sodlum hydroxide solution, but this treatment tends to degrade the cellulose, and in any case involves the use of an additional process step.
• There therefore a need for a process which can be operated continuously at high speed which not only bleaches cellulosic textile fabrics, but also removes any cotton husks and size which may be present, increases the hydrophilicity of the fibers, and does not degrade the cellulose to any substantial degree.
• the present invention provides such a continuous process for bleaching unbleached cellulose, which process comprises contacting the said unbleached cellulose with,
• the compound containing one or more nitrogen-chlorine linkages is, for example, an N-chlorinated organic compound such as N-chlorotoluene-sulphonamide or more advantageously, a chlorinated cyanuric acid.
• N-chlorinated organic compound such as N-chlorotoluene-sulphonamide or more advantageously, a chlorinated cyanuric acid.
• This compound is applied from an aqueous bath having a pH of 4 to 8 and a content of available chlorine from 2 to 20 grams per liter.
• the conventional bleach may be any commercially used bleaching agent, e.g. an alkali metal chlorite or hypochlorite, best results have been obtained by the use of hydrogen peroxide.
• the process of the invention can, if desired, be followed by a treatment of the cellulose in an alkaline bath, and it is an advantage of the new process that this treatment may be very short so that the cellulose material is not degraded to any substantial extent.
• the new process can be carried out as follows.
• the cellulose textile material e.g. in the form of threads, tows, or woven fabric, is passed into a conventional, caster-tank containing an aqueous solution of commercial amylase having a concentration of 2 to 10 grams per liter and at a temperature from 20 to C.
• This bath can also contain 1 to 2 grams per liter of a compatible wetting agent.
• the material remains in this bath for from 5 to 30 seconds, depending upon the concentration of the amylase. It is then squeezed to 50 to wet take-up, washed with boiling water, and squeezed to 50 to 70% wet take-up.
• the cellulose material is passed to a second conventional caster-tank containing the chlorinated derivative of cyanuric acid (or other compound containing a nitrogen-chlorine linkage) in a concentration giving an available chlorine content of 2 to 20 grams per liter, at a temperature of 10 to 60 C. and a pH of 4 to 8.
• the cellulose material can remain in this tank for from 5 to 30 seconds, and be fed at a speed of up to 100 meters per minute, so that the tank can ordinarily contain from, say, 10 to 30 meters of fabric.
• the fabric is washed with hot water and squeezed.
• the consumption of amylase in the first bath is generally between 0.3 and 0.5%, and that of the chlorinecontaining compound in the second bath between 0.1 and 0.8%, the percentages being by weight of the material being treated.
• the cellulose fabric is fed to a tank containing hydrogen peroxide stabilized with sodium silicate, or any other suitable bleach. After leaving this bath, it is squeezed to 60 to 100% wet take-up and then kept for /z to 10 minutes in a J-box or a steamer at 100 C. or for /2 to 1 minute in a steamer under pressure at to C.
• the material is then washed at about 100 C. in sodium hydroxide solution having a concentration of 5 to 10 grams per liter, and finally washed carefully and dried.
• the concentration of hydrogen peroxide is from 1 t0 3% by weight, expressed as 130 volume (35%) hydrogen peroxide. This is approximately the same concentration as is prior processes. However, if it desired to reduce the treatment time with hydrogen peroxide to V2 to 2 minutes at a temperature of 100 C., the concentration of hydrogen peroxide in the treatment bath must be increased to 4 to 5%.
• An alkali metal chlorite e.g. sodium chlorite
• sodium chlorite may be substituted for the hydrogen peroxide. If this is done, it is necessary before the fabric is immersed in the chlorite bath to wash it very thoroughly to remove any excess of chloro-cyanuric compound which would react with the chlorite and cause decomposition of the latter.
• a suitable chlorite concentration is 10 to 30 grams per liter, and the bath can contain a conventional adjuvant such as sodium phosphate.
• the fabric is squeezed to 80 to 100% wet take-up and then kept at a 100 C. ifor to 15 minutes before being Washed and dried. No chlorine dioxide is formed during the bleaching and the product obtained is completely free from husks and stains and has a good degree of whiteness and excellent hydrophilicity.
• the degree of hydrophilicity imparted by a bleaching process may be estimated by measuring the time required for a disc of fabric 20 mm. in diameter to become totally immersed in water at 20 C. after being laid on the surface. For example raw cotton satin bleached in a bath containing 3% of l30-volume hydrogen peroxide (based on the weight of cotton) for minutes at 100 C., after washing and drying, takes longer than 5 minutes to become totally immersed.
• the same fabric has an immersion time of only 2 seconds.
• the treatment with the chlorocyanuric compound is omitted, the preliminary treatment with amylase gives only a relatively insignificant improvement in hydrophilicity.
• EXAMPLE 1 A starch-sized, cotton poplin fabric 140 centimeters in width and weighing 200 grams per meter was subjected to the process of the invention without previous desizing.
• the fabric was fed to a caster-tank having a capacity of 20 meters of the fabric at a rate of 80 meters per minute.
• the bath contained 5 grams of amylase, 10 grams of sodium chloride, and 1 gram of a wetting agent based on the octylester of sulphosuccinic acid, per liter.
• the temperature of the bath was 70 C. and the immersion time seconds.
• the fabric was squeezed to a 70% wet take-up after leaving the tank and then fed to a washing tank containing water at 100 C. and having a capacity of 15 to meters of the fabric.
• Amylase starch size were removed by this washing.
• the fabric was then squeezed to a 55% wet take-up and fed to a second caster-tank containing a solution at 30 C. of 8.25 grams per liter of trichloroisocyanuric acid, 2.29 grams per liter of cyanuric acid, and 4.46 grams per liter of sodium bicarbonate.
• the fabric remained in this tank for 15 seconds and was then squeezed to 70% wet take-up and passed to a washing taiik containing water at 100 C., where it was washed for 10 seconds and the excess isocyanuric acid derivative was removed.
• the fabric was then squeezed to 55% wet take-up and passed to a third tank, it was soaked in a solution at 30 C.
• EXAMPLE 2 A starch-sized cream colored mixed fabric having a cotton warp and a thread-bleached linen woof Weighing 250 grams per square meter was subjected to the treatment described in Example 1 at a rate of 50 meters per minute.
• the first tank contained 5 grams per liter of amylase, 10 grams per liter of sodium chloride, and 2 grams per liter of non-ionic wetting agent. Its temperature was 60" C.
• the bath containing the isocyanuric acid derivative had a temperature of 40 C. and a concentration 50% higher than that described in Example 1.
• the bleaching with hydrogen peroxide was carried out under the conditions described in Example 1.
• the fabric obtained had a degree of whiteness corresponding to white, was perfectly desized, and had a very good degree of hydrophilicity.
• the polymerization degree was reduced from 2100 to 1800.
• the non-cellulosic parts of the linen and the cotton husks were completely removed.
• the amylase employed can be any commercially available amylase or amylase preparations known as a textile desizing agent.
• a textile desizing agent any commercially available amylase or amylase preparations known as a textile desizing agent.
• use can be made of the commercially available Rapidase, a known textile desizing agent.
• EXAMPLE 3 The fabric treated was a mixed polyester/cotton poplin intended for a resin treatment combined with waterproofing.
• the poplin weighed 120 grams per square meter and had a width of centimeters.
• the treatment with amylase was carried out at 70 C. for 20' seconds in a bath containing 7 grams per liter of Rapidase, 10 grams per liter of sodium chloride, and 1 gram per liter of a wetting agent based on an alkyl-aryl sulphonate. After washing, the poplin was contacted for 20 seconds with a bath at 20 C. containing 10 grams per liter of sodium dichloroisocyanurate containing 60% of available chlorine. Washing and bleaching with hydrogen peroxide were carried out as in Example 1, the maturing time being only 5 minutes at C.
• the treated fabric was completely desized and had a high degree of whiteness.
• the degree of polymerization of the cellulose was reduced from 2580 to 2050 and the hydrophilicity was such that the immersion time of a fabric disc was 1 second.
• EXAMPLE 4 A cotton twill fabric intended for vat dyeing on a jigger was treated with amylase and a chlorocyanuric acid derivative as described in. Example 1 and, after washing, was soaked in a solution containing 20 grams per liter of sodium. hydroxide, 20 grams per liter of 36 B. sodium silicate solution, 5 grams per liter of a polymeric sodium metaphosphate, and 50 milliliters of 35% aqueous hydrogen peroxide solution. After squeezing to 100% wet take-up, the fabric was rolled up and rotated slowly for 10 hours at 20 C. The fabric was then unfolded and washed. The husk and starch had been completely removed. The fabric had a sufficient degree of whiteness for dyeing and very good hydrophilicity. The polymerization degree of the cellulose was reduced from 2500 to 2100.
• EXAMPLE 5 A starch-sized mixed cotton/polyamide fabric weighsqueezed to 60% wet take-up. The fabric was then fed to a second castor-tank at 40 C. containing 12.4 grams per liter of trichlorocyanuric acid, 3.3 grams per liter of cyanuric acid, and 6.7 grams per liter of sodium bicarbonate. The fabric was squeezed to 60% wet takeup and then passed unfolded into a washer having 3 tanks wherein the excess of the chlorocyanuric acid derivative was washed out with very hot water. The fabric was then bleached by feeding into a tank containing 15 grams per liter of 100% sodium chlorite, and 3.6 grams per liter of monosodium phosphate.
• the fabric was squeezed to 65% wet take-up and fed to a steamer at 100 C.
• the fabric was folded in a maturing vessel Where it was kept for minutes at 100 C.
• the fabric was fedunfolded into a washer having four tanks, the first containing grams per liter of sodium hydroxide and the other three very hot water. Fabric having good hydrophilicity and very high degree of whiteness was obtained. All the size was removed and the mechanical strength of the fabric was reduced only by 5% compared with the unbleached fabric.
• an aqueous solution of amylase having a concentration of 2 to 10 grams per liter at a temperature from about 20 to 80 C.
• an oxidative bleaching agent which is hydrogen peroxide or sodium chlorite.
• chlorocyanuric compound is sodium dichloroisocyanurate or trichloroisocyanuric acid.
• oxidative bleaching agent is hydrogen peroxide in the form of an aqueous solution containing 1 to 3% by weight of 130 volume (35%) hydrogen peroxide, and the contact time is V2 to 10 minutes.
• oxidative bleaching agent is soduim chlorite in the form of an aqueous solution having a concentration of 10 to 30 grams per liter, and the contact time is 5 to 15 minutes.
• cellulose textile material is in the form of a continuous fabric which is treated continuously at a rate of at least meters per minute.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8631432

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (1)

• 1967
  • 1967-05-24 FR FR107544A patent/FR1531616A/fr not_active Expired
• 1968
  • 1968-05-22 BE BE715571D patent/BE715571A/xx unknown
  • 1968-05-22 AT AT492368A patent/AT284771B/de not_active IP Right Cessation
  • 1968-05-23 US US731640A patent/US3572987A/en not_active Expired - Lifetime
  • 1968-05-24 DE DE19681769442 patent/DE1769442A1/de active Pending
  • 1968-05-24 NL NL6807417A patent/NL6807417A/xx unknown
  • 1968-05-24 GB GB25080/68A patent/GB1219467A/en not_active Expired

Also Published As

Similar Documents