Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
  • D01F2/06—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from viscose
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
  • D01F2/06—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from viscose
  • D01F2/08—Composition of the spinning solution or the bath
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
  • Y10S264/27—Process of spinning viscose where viscose has high degree of polymerization

Definitions

• the present invention relates to a process for manufacturing low alkaline viscose of macrocellulose molecules, consisting in obtaining low alkaline macro-molecular cellulose from cellulose material having initially a degree of polymerization (abbreviation-D. P. will be used hereinafter) above 800, by steeping same in a steeping solution, as low in caustic soda as possible, in accordance with the D. P.
• the object of the present invention lies in manufacturing a low alkaline viscose consisting of macro-cellulose molecules-on a commercial scale, which is readily spinnable in either an alkaline, neutral or 3% dilute sulphuric acid bath, from macro-molecular ,cellulose, as raw material, possessing D. P. above 800, for the purpose of manufacturing-the macromolecular rayon fiber with D. P. above 500, 'of high dryand wet-strength and of high durability.
• a. low cellulose, high alkali and low viscosity viscose is prepared from material pulp-of around 700 D. P., by xanthating and dis-'- solving same in the usual way, under abolition of aging, which lowers the D. P. of the alkali cellulose most remarkably, and that the regenerated fiber obtainable from above viscose by spinning in an ordinary way possesses a D. P. below 400 and can display no characteristic peculiar to the macro-molecular structure.
• the caustic soda concentration of the steeping solution is varied substantially inversely with the D. P. of cellulose material.
• the steeping is conducted at first under 'reducedpressure in order to meet'the decrease in combined caustic soda due to the said dilution, thus facilitating the permeation of the steeping solution into the cellulose material quickly and uniformly, and simultaneously excluding oxygen occluded in the steeping solution as well as in the material fiber, so that the lowering of the D. P. of cellulose that might otherwise be caused by the decomposition due to oxidation duringand after formation of falkali'cellulose, canbe suppressed.
• Shredding is conducted at low temperature in a short interval in nitrogen atmosphere in order that low alkaline macro-molecular cellulose may be obtained by checking the fall of D. P. of said alkali cellulose.
• the oxygen in the reaction apparatus which will otherwise effect the decrease of D. P. during xanthation, is replaced beforehand with nitrogen while the apparatus is kept vacuum.
• the xanthation is carried out in an inert gas, under the pressure corresponding to D. P. of material cellulose.
• the sodium xanthogenate cellulose obtained by the xanthation is not dissolved in alkaline water as in the usual process, but is dissolved in a mixture of water and carbon bisulphide. or by water and carbon bisulphide alternatively added, so that a viscose suitable to spinning is obtained.
• the D. P. of cellulose of viscose obtained is extremely high and free alkali content is low. Therefore, the said viscose can be spun either in an alkaline, a neutral or less than 3% sulphuric acid bath, low in sodium sulphate.
• macromolecular rayon fiber can be obtained having the characteristic properties peculiar to the macromolecular structure.
• Case 1.Raw material Refined cotton linter or special pulp of D. P. 800-1000.
• the cellulose material is steeped in an alkaline solution (16-17 weight per cent caustic soda solution) for 20-30 minutes under less than 60 mm. pressure.
• the reaction is con- 4 tinued for 30-60 minutes under l-3 atmospheric pressure of inert gas, and it is then pressed down to 2.7-2.9 times the weight of cellulose and immediately shredded in nitrogen atmosphere at as low temperatureand for as short a duration as possible.
• an alkali cellulose with sodium hydroxide-cellulose ratio equal to 0.40-0.45. Without subjecting to aging, it is xanthated in a xanthating apparatus, and 45-55% carbon bisulphide is added.
• the air in the reaction apparatus is previously replaced with nitrogen gas and a desired quantity of carbon bisulphide is added under reduced pressure.
• the pressure is raised up to 1-3 atmospheric pressure by introducing such inert gas as nitrogen and the reaction is continued for further -120 minutes.
• the ratio of sodium hydroxide to cellulose in alkali cellulose is 0.37-0.40. It is pressed down to as heavy as 2.6-2.8 times the weight of cellulose and transferred to xanthation after shredding similarly as in Case 1.
• composition of the viscouse thus obtained is of 3-8% cellulose and 1.10-3.20% total alkali
• the sodium hydroxide/cellulose of the alkali cellulose was found to be 0.30-0.34.
• composition of the viscose obtained in the above way is of 1.5-6.0% cellulose and 0.4-2.00%
• the alkali cellulose thus obtained was found to be 33.5% of cellulose and 14.1% of total alkali.
• the regenerated cellulose has D.
• the produced sodium cellulose xanthogenate is dissolved at 15 deg. C. in such way that first /is of the total dissolving water being sprayed, followed by 30 minute agitation, then carbon bisulphide (5% to cellulose) being added, followed by 30 minute agitation, the remaining waterportion being added finally, with agitation kept throughout above manipulation, we obtain a product, viscose.
• the regenerated cellulose was found to have D. P. of 550.
• EXAMPLE 11 As raw material, refined cotton linter of D. P. of 1,120 was used. It was steeped in 15.4% sodium hydroxide solution at 18 deg. C. for 20 minutes under 60 mm. vacuum and then for 60 minutes under 8 atmospheric pressure in nitrogen gas. The product was pressed down as heavy as 2.7 times the weight of cellulose and shredded similarly as in Example 1. The constituents of the alkali cellulose were found to be 36.4% cellulose and 13.5% total alkali.
• This product was xanthated in reaction apparatus similar as used in Case 1. First the air in the apparatus was replaced with nitrogen gas and the product was xanthated under reduced pressure. Then carbon bisulphide (46% to cellu-- lose) was added, and after 60 minutes the reaction was continued for further minutes under 5 atmospheric pressure in nitrogen at 23 deg. C. The resolution was carried out as in Case 1.
• the regenerated cellulose had D. P. of 720.
• EXAMPLE III As raw material, refined cotton linter of D. P. of 1,350 was used. It was steepedin 18% sodium hydroxide solution at 20 deg. C. for 15 minutes. The product was pressed down as heavy as 2.8 times the weight of cellulose and again steeped in 14.2% sodium hydroxide solution for 20 minutes, under 20 mm. vacuum, and then for 60 minutes at 16 deg.-C. under 12 atmosphericpressure. The product was pressed down. as heavy as 2.6 times the weight of cellulose and shredded similarly as in Example 2.
• alkali cellulose werefound to be of 37.2% cellulose and 13.0% total alkali. This was xanthated similarly as in the previous example; with carbon bisulphide (50% to cellulose). for 60 minutes at 23 deg. C. under 8 atmospheric pressure, and [is of total dissolving water was added, followed by 30 minute agitation and then carbon bisulphide (5% to cellulose) added, followed by 30 minute agitation. The similar quantity of carbon bisulphide and water respectively were added by turn, the agitation still being continued until all the carbon bisulphide and water were added to make perfect viscose.
• the regenerated cellulose has D. P. of 1,150.
• the viscose manufactured according to the new methods of the present invention has many excellent qualities: as the D. P. of the product increases, there is an increase of dryand wet-strength, ratio of dryand wet strength, elastic property and durability and capability of manufacturing rayon fiber of macrocellulose molecules with high practical value.
• the present invention can prepare economically in practice a. cellulose of D. P. oi cellulose material D. P. of product 3004, 000 5004300 1, 000-1, 200 000-800 1, 200-1, 400 800%, 000 Higher than 1,400 Higher than 1, 000

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)

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Cited By (12)

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Citations (7)

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• 1950
  • 1950-02-20 US US145307A patent/US2592355A/en not_active Expired - Lifetime
  • 1950-09-06 DE DES18980A patent/DE971888C/de not_active Expired
  • 1950-09-06 FR FR1027388D patent/FR1027388A/fr not_active Expired
  • 1950-10-30 GB GB26456/50A patent/GB711040A/en not_active Expired
  • 1950-11-04 BE BE499160D patent/BE499160A/xx unknown
  • 1950-11-30 NL NL157649A patent/NL86618C/xx active
• 1951
  • 1951-03-12 CH CH320258D patent/CH320258A/de unknown

Patent Citations (7)

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