US3151191A - Process of regenerating spent spin bath and composition thereof - Google Patents

Process of regenerating spent spin bath and composition thereof Download PDF

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Publication number
US3151191A
US3151191A US48643A US4864360A US3151191A US 3151191 A US3151191 A US 3151191A US 48643 A US48643 A US 48643A US 4864360 A US4864360 A US 4864360A US 3151191 A US3151191 A US 3151191A
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United States
Prior art keywords
spin bath
conductivity
spent
bath
cellulose triacetate
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US48643A
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English (en)
Inventor
Jesse L Riley
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Celanese Corp
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Celanese Corp
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Filing date
Publication date
Priority to NL268098D priority Critical patent/NL268098A/xx
Application filed by Celanese Corp filed Critical Celanese Corp
Priority to US48643A priority patent/US3151191A/en
Priority to DEC24836A priority patent/DE1266442B/de
Priority to GB28753/61A priority patent/GB973094A/en
Priority to BE607087A priority patent/BE607087A/fr
Priority to FR870598A priority patent/FR1311194A/fr
Priority to US367275A priority patent/US3284554A/en
Application granted granted Critical
Publication of US3151191A publication Critical patent/US3151191A/en
Priority to US401886A priority patent/US3284558A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D35/00—Producing footwear
    • B29D35/0009—Producing footwear by injection moulding; Apparatus therefor
    • B29D35/0018—Moulds
    • B29D35/0036—Moulds with displaceable sole plates
    • A—HUMAN NECESSITIES
    • A43—FOOTWEAR
    • A43B—CHARACTERISTIC FEATURES OF FOOTWEAR; PARTS OF FOOTWEAR
    • A43B1/00—Footwear characterised by the material
    • A43B1/0027—Footwear characterised by the material made at least partially from a material having special colours
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D35/00—Producing footwear
    • B29D35/0054—Producing footwear by compression moulding, vulcanising or the like; Apparatus therefor
    • B29D35/0063—Moulds
    • B29D35/0081—Moulds with displaceable sole plates
    • 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
    • D01F13/00—Recovery of starting material, waste material or solvents during the manufacture of artificial filaments or the like
    • D01F13/02—Recovery of starting material, waste material or solvents during the manufacture of artificial filaments or the like of cellulose, cellulose derivatives or proteins
    • 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
    • D01F2/24—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from cellulose derivatives
    • D01F2/28—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from cellulose derivatives from organic cellulose esters or ethers, e.g. cellulose acetate
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
    • Y02P70/62—Manufacturing or production processes characterised by the final manufactured product related technologies for production or treatment of textile or flexible materials or products thereof, including footwear

Definitions

  • the present invention relates to a novel spin bath in the wet spinning of cellulose esters to produce shaped structures and to novel processes for the treatment and regeneration of spent spin bath.
  • the deposited solids are essentially cellulose triacetate fines of somewhat lower average molecular weight than the filaments and that deposition of such suspended cellulose triacetate in the coagulation apparatus can be reduced if the formula C2--7C-i-10 has a positive value where C is the conductivity in micromhos of the liquid in which coagulation takes place, i.e. substantially the spent spin bath.
  • C is the conductivity in micromhos of the liquid in which coagulation takes place, i.e. substantially the spent spin bath.
  • the composition of the liquid in which coagulation takes place whose conductivity is to be controlled according to the present invention, can be computed from a knowledge of the compositions of dope, fresh spin bath and freshly formed filaments and from a knowledge of the mass rates at which the dope and spin bath are supplied and the filaments are withdrawn. While cellulose triacetate, methylene chloride and methanol are all substantially non-conducting, in practice it has been found that the spent spin bath has an appreciable conductivity but one for which C2-7C-l-l0 has a negative value. This conductivity is apparently 'the result of introduction of ions with the dope or fresh spin bath.
  • the cellulose triacetate always contains some ions introduced from the original cellulose, from the acetylation catalyst, the catalyst neutralization, the water washes, etc. These 1n "part are transferred to the methylene chloride-methanol spin bath which when recycled as fresh spin bath 3l,l5l,l9l Patented Sept. 29, i964 ice also serves to introduce ions. In addition, there is unavoidably some small amount of water associated with the methanol as well as ionic contaminants in the methylene chloride and methanol introduced either during manfacture or by corrosion of vessels and lines. Even if the fresh spin bath were substantially non-conducting, the liquid in which coagulation takes place may be quite conductive due to the ions introduced with the dope.
  • Reduction in the conductivity of the spent spin bath can generally be accomplished by supplying fresh spin bath having a conductivity of less than about 0.5 micromho, the exact Value depending upon the relative feed rates of dope and fresh spin bath. If there is employed a dope having a higher conductivity it will be necessary to compensate by employing fresh spin bath of lower conductivity.
  • the preferred treatment involves Contact of the spent spin bath with an ion exchange resin.
  • an ion exchange resin there can be employed an anion exchangeresin or a cation exchange resin or both either in admixture or in succession.
  • they operate on hydroxyl or hydrogen cycles; as explained hereinafter, however, different ions have different effects on the spent spin bath and accordingly even if the ion exchange resin operated on the sodium cycle it would result in a decrease in conductivity
  • the principal cations in the spent spin bath are calcium, iron, or the like.
  • cation exchange resin sold under the name DoweX 50WX-8 by the Dow Chemical Co.
  • Natural and/or inorganic ion exchange resins can also be employed.
  • a partial list of suitable cation exchange resins includes sulfonated styrene-divinyl benzene copolymers, phenol-formaldehyde resins, phenol-formaldehyde-suliite reaction products, sulfonated coal, and the like.
  • a partial list of suitable anion exchange resins includes the reaction product of a tertiary amine with the chloromethylated copolymer of styrene and divinyl benzene, the reaction product of an alkylating .agent such as methyl chloride or dimethyl sulfate with an amine-containing resin such as is obtained by reaction. of formaldehyde, aniline and ethylene diamine, and the like.
  • ion exchange resins When employing ion exchange resins preferably they are used as particles supported on a screen with spent spin bath flowing upwardly therethrough. This nuidizes the resin, prevents channeling of the spin bath and prevents the resin from functioning as a nlter on which the suspended cellulose triacetate particles would settle if ilow were downward.
  • the ex-act particle sizes of ion exchange resins to achieve the desired effect will vary somewhat in dependence upon the shape of the container and the now rate; generally, however, the particle size of the resins will range from about 0.01 to 0.05 inch and preferably from about 0.02 to 0.03 ⁇ inch in diameter.
  • the composition of the de-ionized spin bath is then adjusted, advantageously with de-ionized solvents, and it is recycled as fresh spin bath.
  • the cellulose triacetate fines being recycled in the fresh spin bath will generally com stitute about 0.02 to 0.5 and preferably about 0.08 to 0.12% of the spin bath.
  • a spin bath containing cellulose triacetate so that the system will be at steady state .substantially from the outset.
  • the cellulose triacetate nnes will coat out on the ion exchange resin particles and may reduce their eniciency. Accordingly, it is advantageous to soak the resin periodically in a solvent for cellulose triacetate to clean the particles; this solvent may be evaporated to separate the solvent from the residual cellulose triacetate which may be discarded.
  • the number of ions involved in the reduction of conductivity is so small that the resin can be used for months without regeneration.
  • now of spent spin bath can be collected in a reservoir or it may be passed to a second resin arranged in parallel to the first.
  • the volume of spent spin bath will obviously be greater than the volume of fresh spin bath supplied to the system in a given time interval, due to the solvent introduced from the dope. Accordingly a portion of the spent spin bath is generallywithdrawn, advantageously before passage through the ion exchange resin or other conductivityadjusting means, and may be treated to recover its values.
  • One suitable treatment of this type involves withdrawal of a portion of spent spin bath containing about as much suspended cellulose triacet-ate fines as are left behind in the spent spin bath per cycle, ejg.
  • non-ionic peptizing or dispersing agents may be added to the dope or spin bath, fresh or spent, to assist in keeping the cellulose triacetate fines suspended.
  • Representative dispersing agents include the higher fatty acid esters of polyalkylene glycols, e.g'. the mono-oleate of polyethylene glycol, blown sperm oil (oleyl esters of palmitic, myrist-ic and stea'ric 4acids aerated hot), and the like. These substances are preferably present in from about 0.08 to 0.15% by weight of cellulose triacetate in the dope although as muc-h as 0.5% or even more can be present, if desired.
  • electrolytes are preferably added to the system in predetermined amounts more or less frequently to compensate for the loss of ions in that portion of the spent spin bath which is withdrawn to reduce Vthe volume of recyled spin bath.
  • the spent spin bath is collected, allowed to settle for about 1 to 4 hours and about 50 to 99% and preferably about 90 to 99% of the spent spin bath is removed from the supernatant liquid and forwarded for recycle as fresh spin bath after adjustment of its composition and volume by addition of solvent and possibly electrolyte.
  • the settling may be effected in a single stage or in a plurality of stages, although care should be taken not to complicate settling by re-dispersing settled solids in supernatant liquid.
  • the separated liquid recycled as fresh spin bath will contain cellulose acetate in about the same proportion as when de-ionized spin bath is employed although the intrinsic viscosity and acetyl value of the cellulose acetate will in this case be much lower dueto selective settling out of the material of higher intrinsic viscosity and acetyl value,
  • certain ions are especially effective in accelerating settling, viz. the ions of polyvalent metals and especially cations of metals of Group Il of the periodic table, copper, aluminum, chromium, iron, nickel or cobalt.
  • aV spent spin bath whose conductivity is raised from 2 micromhos to l0 micromhos byV addition of calcium acetate will settle much more rapidly than when the same increase in conductivity is effected by addition of sodium or ammonium acetate.
  • the metal electrolytes can be added in finely divided ele mental state, relying on substances in the spent spin bath to oxidize and ioniz'e the metals, e.g.
  • a par i tial list of other materials which have proven effective includes FeCl3, CuCl2, ammonium acetate, AlCl3, am monium hydroxide, sodium acetate, ZnCl2, NaCl, ammonium phosphate, FeSO4, Al2(SO4)3, Na2HPO4, CuSO4, NaOH, CuO, etc., as Well as metallic Fe, Cu, Pb, Al and Zn in the form of powder, wire or ne turnings.
  • cellulose triacetate has reference to cellulose acetate having fewer than about 0.29 and preferably fewer than about 0.12 free hydroxyl group per anhydroglucose unit of the cellulose molecule, i.e. an acetyl value in excess of about 59% and preferably in excess of about 61% by weight calculated as combined acetic acid.
  • the methylene chloride dope solvent may comprise up to about 20% and preferably about to 15% of a lower alkanol such as methanol although ethanol and isopropanol are almost as good.
  • the composition of the methylene chloridemethanol spin bath will vary in dependence upon its temperature.
  • the methylene chloride concentration is approximately governed by the formula 751A minus the spin bath temperature in C iS. Since spinning is usually carried out Within the temperature range of about to 45 C., the methylene chloride will generally constitute about to 65% of the weight of the methylene chloridemethanol.
  • the spin bath may also contain small amounts of water. Other halogenated lower alkanes plus other lower alkanols may be substituted although the results are not generally as good.
  • the wet spinning of course may be designed to obtain shaped structures other than filaments, e.g. sheets, etc.
  • the process can be applied to wet spinning other lilament-forming materials into other spin baths in which fines of the filament-forming material become suspended.
  • the filament-forming material could comprise, for example, acetone-soluble secondary cellulose acetate as well as esters of cellulose with one or more organic or inorganic acids such as cellulose acetate-formate, cellulose acetatepropionate, cellulose propionate, cellulose acetate-propionate-butyrate, cellulose acetate-butyrate, cellulose butyrate, cellulose nitrate, and the like, the esters having varying degrees of substitution.
  • the dope solvent and spin bath compositions will of course depend upon the identity of the filament-forming material.
  • spin baths other than methylene chloride-methanol can also be successfully employed such as aqueous solutions containing up to about 15% of methylene chloride and about 45 to 70%, alone or in admixture, of a glycol, a polyglycol or hydroxylated cyclic ether as described in Belgian Patent 571,379, e.g.
  • tetrahydrofurfuryl alcohol propylene glycol-1,2, 2-methylpentanediol-2,4, 3-methyl-pentanediol-2,4, diethylene glycol, triethylene glycol, di-ethyl or di-methyl ether of diethylene glycol, S-methoxybutanol-l, hexanediol-2,5, etc.
  • the dope may also contain small amounts of these solvents or of a lower alkanol such as methanol or isopropanol.
  • FIG. l is a schematic ow sheet of an apparatus employing ion exchange to reduce conductivity
  • FIG. 2 is a schematic flow sheet of an apparatus ernploying electrolyte addition to increase conductivity.
  • FIG. 1 there is shown a spin pot 11 housing a spinnerette 12 to which there is supplied a dope of filament-forming material through pipe 13.
  • Fresh spin bath is supplied to the spin pot 11 through pipe 14.
  • Spent spin bath in head box 17 drains into sump 18 from which the major portion of the spent spin bath is caused to ow upwardly through a column 19 in which a mixture of cation and anion exchange particles 20 rests freely between Widelyspaced relatively large mesh screens 21.
  • the deionized liquid leaving the column 19 passes to a composition adjusting tank 22 which feeds pipe 14. Additional liquid is supplied to tank 22 through line 23 in order to adjust the composition of the etiluent from tank 22 to that required for fresh spin bath.
  • a portion of the eflluent from sump 18 is passed to an evaporator 24 in which solvents are withdrawn overhead, condensed at 25 and collected in receiver 26.
  • the non-volatiles principally comprising cellulose triacetate, are withdrawn from evaporator 24 at 27 to be discarded, or put to other use.
  • a portion of the distillate in receiver 26 is withdrawn from the system at 28 to be used for making fresh dope or the like and a portion is recycled through pipe 29 to be combined in tank 22 with the effluent from column 19 and the liquid supplied through line 23 in adjusting the composition of fresh spin bath supplied through pipe 14.
  • the system shown in FIG. 2 is employed where the conductivity of the spent spin bath is maintained high to accelerate settling.
  • the apparatus is generally the same as in FlG. 1 except-that column 19 of FIG. 1 has been replaced by a settler 30 which is fed by gravity with all the liquid from sump 18.
  • the overiiow from settler 30, relatively light in cellulose triacetate lines, is recycled while the underflow, relatively rich in cellulose triacetate lines, is treated for solvent recovery.
  • Electrolytes may be added to the system along with the liquid introduced at 23, along with the dope supplied at 13 and/or along with ythe spent spin bath supplied to settler 30 to accelerate settling and to compensate for the electrolyte lost at Z7.
  • the electrolyte will be incorporated not only in the recycling portion but also in the underflowing portion which is directly removed from the recirculating system. This seeming waste is countered by the increased rate of settling achieved in settler 30.
  • Example I Using an apparatus such as shown in FIG. l there is supplied at 13 at the rate of 30 parts per hour a solution comprising 21.7/ 70/ 7.7/ 0.5/ 0.1 cellulose triacetate/methylene chloride/methanol/water/dispersing agent; the dispersing agent comprises 60/ 20/ 20 mineral oil/blown sperm oil/polyethylene glycol monooleate. 1100 parts per hour of fresh spin bath comprising 38/ 61.4/ 0.1/ 0.5 methylene chloride/methanol/cellulose triacetate/water is supplied at 14. The conductivity of the dope is 0.07 micromho, of t'ne fresh spin bath 0.4 micromho.
  • the conductivity of the spent spin bath in sump 1S is 1.8 micromhos and 82% of this spent spin bath is passed through column 19 in which there is loosely arranged a mixture of a strong cation exchange resin ⁇ on the ⁇ hydrogen cycle (Dowex 21K) and a strong anion exchange resin on the hydroxyl cycle.
  • the conductivity of the liquid leaving the column 19 is 1.8 micrornhos and it is forwarded to tank 22 along with 34 parts per hour of methanol supplied at 23 and having a conductivity of 0.3 micromho.
  • the 18% of spent spin bath forwarded to evaporator 24 there is withdrawn at 27 9 parts per hour of 9/84/5/2 methylene chloride/ methanol/ cellulose triacetate /water.
  • the distillate in 26 comprises 190 parts per hour of which 23% is purged at 28 and the remainder recycled at 29; its conductivity is 0.3 micrornho.
  • the unaccounted for methylene chloride, methanol and water leave the system along with the cellulose triacetate tow.
  • the spinning column remains clear and spinning is stable for long periods of time when practicing the process of this example, if the ion exchange resins are removed from column 19 the conductivity in column 16 (assumed to be the same as in sump 18) increases to an undesired level and cellulose triacetate fines encrust the spinnerette 12, clog up column 16, sump 18, tank 22 and the associated lines, interfering with spinning and necessitating shut-down.
  • Example Il Using the apparatus shown in FIG. 2 the same dope as in Example I is fed at the same rate. 1100 parts per hour of fresh spin bath comprising 38.5/ 61.5 methylene chloride/methanol (excluding its ionic content) is supplied at 14, having a conductivity ot' 100 micromhos. The conductivity of the spent spin bath in sump 18 is 101 micrornhos.
  • the overflow from settler 30 comprises 1080 parts per hour of 39.4/60.3/ 0.03 methylene chloride/rnethanol/cellulose triacetate having a conductivity of 101 micromhos.
  • the underflow from settler 30 comprises 20.3V parts per hour of 38.9/59.6/ 1.5 methylene chloride/methanol/cellulose triacetate having a conductivity of 101 micromhos.
  • said shaped structure and spent spin bath are continuously Withdrawn from: said zone, and a portion of the spent spin bath is recycled to said zone, the improvement which comprises removing ions from said recycling portion in an amount such that the conductivity. of the vliquid in said Zone is maintained between about 0.3 to 2 micrornhos.
  • a spin bath comprising a mixture of methylene chloride and methanol of which the methylene chloride constitutes about 25 to 65% by weight, said spin bath having about 0.02 to 0.5% by weight of cellulose triacetate suspended therein and having a conductivity ranging between about 0.3 to 2 micromhos.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Textile Engineering (AREA)
  • Artificial Filaments (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
US48643A 1960-08-10 1960-08-10 Process of regenerating spent spin bath and composition thereof Expired - Lifetime US3151191A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
NL268098D NL268098A (xx) 1960-08-10
US48643A US3151191A (en) 1960-08-10 1960-08-10 Process of regenerating spent spin bath and composition thereof
GB28753/61A GB973094A (en) 1960-08-10 1961-08-09 Artificial filament production
DEC24836A DE1266442B (de) 1960-08-10 1961-08-09 Verfahren zur Herstellung von Faeden oder Folien durch Nassverspinnen von Celluloseestern
BE607087A BE607087A (fr) 1960-08-10 1961-08-10 Procédé de production de filaments d'esters cellulosiques
FR870598A FR1311194A (fr) 1960-08-10 1961-08-10 Procédé de production de filaments d'esters cellulosiques
US367275A US3284554A (en) 1960-08-10 1964-04-22 Process of regenerating spent spin bath and composition thereof
US401886A US3284558A (en) 1960-08-10 1964-10-06 Injection molding composite bottoms

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US48643A US3151191A (en) 1960-08-10 1960-08-10 Process of regenerating spent spin bath and composition thereof

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US3151191A true US3151191A (en) 1964-09-29

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US48643A Expired - Lifetime US3151191A (en) 1960-08-10 1960-08-10 Process of regenerating spent spin bath and composition thereof

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US (1) US3151191A (xx)
BE (1) BE607087A (xx)
DE (1) DE1266442B (xx)
GB (1) GB973094A (xx)
NL (1) NL268098A (xx)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3527501A (en) * 1968-01-04 1970-09-08 Shell Oil Co Resonant vibratory impulse plow

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB788315A (en) * 1954-11-23 1957-12-23 British Celanese Improvements in the manufacture of cellulose triacetate filamentary materials

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB788315A (en) * 1954-11-23 1957-12-23 British Celanese Improvements in the manufacture of cellulose triacetate filamentary materials

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3527501A (en) * 1968-01-04 1970-09-08 Shell Oil Co Resonant vibratory impulse plow

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Publication number Publication date
NL268098A (xx) 1900-01-01
DE1266442B (de) 1968-04-18
BE607087A (fr) 1961-12-01
GB973094A (en) 1964-10-21

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