Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
  • D06M13/184—Carboxylic acids; Anhydrides, halides or salts thereof
  • D06M13/188—Monocarboxylic acids; Anhydrides, halides or salts thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B1/00—Preparatory treatment of cellulose for making derivatives thereof, e.g. pre-treatment, pre-soaking, activation
  • C08B1/02—Rendering cellulose suitable for esterification
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
  • C08B3/00—Preparation of cellulose esters of organic acids
  • C08B3/06—Cellulose acetate, e.g. mono-acetate, di-acetate or tri-acetate

Definitions

• the present invention concerns a method for manufacturing partially acylated cellulose foil or fiber in which the foil or fiber which is to be esterified is at first swollen at elevated temperature and subsequently esterified, whereupon the product is washed and dried.
• regenerated cellulose presents drawbacks as low wet strength and brown discoloration at high temperatures
• methods have been developed in which the properties of regenerated cellulose foil or fiber are improved by means of partial acylation.
• the objectionable characteristics of regenerated cellulose foil or fiber can indeed be eliminated because partially acylated regenerated cellulose foil or fiber has good heat resistance and high wet strength.
• initial treatment of the regenerated cellulose foil or fiber has been accomplished by first swelling the foil or fiber in aqueous solutions of salts, after which step it has been necessary to dry the swollen foil or fiber prior to esterification and only after this has the acylating process been performed with acid anhydrides.
• the object of the present invention is to afford a method for acylating regenerated cellulose foil or fiber which is superior to previous methods in speed and simplicity.
• the invention is accordingly mainly characterized in that swelling of the foil or fiber is accomplished in a substantially water-free aliphatic carboxylic acid solution containing salt of an alkali metal and an aliphatic carboxylic acid and that the product thus obtained is immediately esterified in a manner previously known in itself in a solution of the anhydride of a low-molecular carboxylic acid which contains salt of an alkali metal and an aliphatic carboxylic acid.
• alkali metal salts of low-molecular aliphatic carboxylic acids solved in aliphatic carboxylic acids, are most effective for use as cellulose-swelling agents in the method for manufacturing partially acylated regenerated cellulose concerned here.
• Alkali metal acetates solved in acetic acid have been found to be the most efficient ones among them.
• composition of the acid anhydride solutions used in the method may vary considerably. It is possible to use for acylating agent merely the anhydride of some low-molecular carboxylic acid or a mixture of these. With increasing molecular size of the anhydrides increasingly soft products are obtained, e.g., compared to the use of acetic acid anhydride alone.
• reaction accelerators in the esterifying solution the same salts are most effective as are used for bloating agents in the pretreatment.
• raw material e.g., unsoftened regenerated cellulose foil or fiber
• Pretreatment is accomplished by immersing the regenerated cellulose foil or fiber into a swelling bath at elevated temperature, e.g., at 50-l40 C.
• the pretreated product thus obtained is immediately immersed, without intervening drying, into the esterifying solution at elevated temperature, e.g., at lO-l 70 C.
• the acylated foil is washed with acetic acid and with water.
• Fiber may also be washed with water alone, whereby the luster characteristic of the fibers can be dulled.
• the foils or fibers may be bleached upon completed washing if necessary,
• the partially acylated product may also be immersed into a solution containing a softener prior to drying.
• Drying is accomplished by the usual method employed for regenerated cellulose.
• the dry tensile strengths of the foils were determined according to the ASTM D 1708-59 method. The determination of wet tensile strength differed from the said method in that the test specimens were kept immersed in water at room temperature for 20 hours prior to the tensile test. The average dry and wet strengths of the original regenerated cellulose foils were 1,300 and 200 kp/cm. The determinations of heat resistance were carried out according to the ASTM D 1637-61 method, stating as the heat resistance of the foil the temperature at which the elongation of the specimen was 2 percent of its original length. The heat resistance of the regenerated cellulose foil, according to the ASTM D 1637-61 method, was 200 C.
• the brown discoloration of the foils was studied by keeping the samples for 1 hour at 210 C. and, subsequently, determin ing their transparency with a spectrophotometer according to the ASTM D 1746-62 method.
• the transparencies were stated in percent at the wavelengths of 400 and 550 mu.
• Prior to the heat treatment the transparencies of the original as well as the partially regenerated cellulose foil amounted to 84-85 percent at 400 mu and to 87-88 percent at 550 mu.
• the transparency of the original regenerated cellulose foil after heating for 1 hour at 200 C. was 67-70 percent at 550 my. and 40-42 percent at 400 mu.
• Acetic anhydride Potassium acetate Acetic acid 92 parts by weight 5 parts by weight 3 parts by weight
• the end product had the following properties:
• EXAMPLE 7 The test was performed as in Example l, but commercial regenerated cellulose foil (plasticizer content, about 10 percent) was used instead of isotropic foil.
• the esterifying solution had the following composition:
• the wet strength of the partially esterified (acetyl content, 30-35 percent) regenerated cellulose foil is markedly better than that of the merely regenerated cellulose foil (200 kp/cm?) and nearly equals that of cellulose acetate foils (450 kp/cm.
• the heat resistance of partially acetylated regenerated cellulose foil is 200 C. if the acetyl content is 33 percent.
• Such partially esterified cellulose foil is not soluble in a cellulose solvent such as Cadoxene solution nor in cellulose acetate solvents such as acetone, 2-methoxy ethanol acetic acid or chloroform.
• the method for manufacturing partly acetylated regenerated cellulose film or fibers which comprises swelling the film or fibers in a substantially water-free acetic acid solution of an alkali metal acetate at a temperature of 50l40 C. and immediately thereafter esterifying them without drying by an acetic acid anhydride solution containing alkali metal acetate at a temperature of l-l70 C. and then washing and drying them.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Biochemistry (AREA)
• Materials Engineering (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Textile Engineering (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8508006

Family Applications (1)

Country Status (13)

Cited By (4)

Citations (7)

• 1967
  • 1967-11-17 FI FI3106/67A patent/FI40833B/fi active
• 1968
  • 1968-11-13 NO NO04502/68A patent/NO128112B/no unknown
  • 1968-11-13 AT AT1104468A patent/AT297911B/de not_active IP Right Cessation
  • 1968-11-14 DE DE19681808937 patent/DE1808937A1/de not_active Withdrawn
  • 1968-11-14 BR BR204039/68A patent/BR6804039D0/pt unknown
  • 1968-11-14 BE BE723844D patent/BE723844A/xx unknown
  • 1968-11-14 GB GB53966/68A patent/GB1177749A/en not_active Expired
  • 1968-11-14 US US775952A patent/US3649341A/en not_active Expired - Lifetime
  • 1968-11-15 FR FR1594781D patent/FR1594781A/fr not_active Expired
  • 1968-11-15 NL NL6816277A patent/NL6816277A/xx unknown
  • 1968-11-15 SE SE15536/68A patent/SE340690B/xx unknown
  • 1968-11-16 PL PL1968130096A patent/PL72603B1/pl unknown
  • 1968-11-18 DK DK560468AA patent/DK118575B/da unknown

Patent Citations (8)

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