EP1237931A1 - Ethers de cellulose a faible viscosite, pouvant floculer dans l'eau chaude, leur procede de production par depolymerisation et leur utilisation - Google Patents

Ethers de cellulose a faible viscosite, pouvant floculer dans l'eau chaude, leur procede de production par depolymerisation et leur utilisation

Info

Publication number
EP1237931A1
EP1237931A1 EP00960577A EP00960577A EP1237931A1 EP 1237931 A1 EP1237931 A1 EP 1237931A1 EP 00960577 A EP00960577 A EP 00960577A EP 00960577 A EP00960577 A EP 00960577A EP 1237931 A1 EP1237931 A1 EP 1237931A1
Authority
EP
European Patent Office
Prior art keywords
cellulose ether
cellulose
water
degradation
cellulose ethers
Prior art date
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.)
Withdrawn
Application number
EP00960577A
Other languages
German (de)
English (en)
Inventor
Alf Hammes
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SE Tylose GmbH and Co KG
Original Assignee
SE Tylose GmbH and Co KG
Clariant GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by SE Tylose GmbH and Co KG, Clariant GmbH filed Critical SE Tylose GmbH and Co KG
Publication of EP1237931A1 publication Critical patent/EP1237931A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D101/00—Coating compositions based on cellulose, modified cellulose, or cellulose derivatives
    • C09D101/08—Cellulose derivatives
    • C09D101/26—Cellulose ethers
    • C09D101/28—Alkyl ethers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B11/00—Preparation of cellulose ethers
    • C08B11/20—Post-etherification treatments of chemical or physical type, e.g. mixed etherification in two steps, including purification
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L33/00—Modifying nutritive qualities of foods; Dietetic products; Preparation or treatment thereof
    • A23L33/10—Modifying nutritive qualities of foods; Dietetic products; Preparation or treatment thereof using additives
    • A23L33/125—Modifying nutritive qualities of foods; Dietetic products; Preparation or treatment thereof using additives containing carbohydrate syrups; containing sugars; containing sugar alcohols; containing starch hydrolysates
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K8/00—Cosmetics or similar toiletry preparations
    • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
    • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
    • A61K8/73—Polysaccharides
    • A61K8/731—Cellulose; Quaternized cellulose derivatives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B11/00—Preparation of cellulose ethers
    • C08B11/02—Alkyl or cycloalkyl ethers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B11/00—Preparation of cellulose ethers
    • C08B11/02—Alkyl or cycloalkyl ethers
    • C08B11/04—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals
    • C08B11/08—Alkyl or cycloalkyl ethers with substituted hydrocarbon radicals with hydroxylated hydrocarbon radicals; Esters, ethers, or acetals thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B11/00—Preparation of cellulose ethers
    • C08B11/193—Mixed ethers, i.e. ethers with two or more different etherifying groups
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D101/00—Coating compositions based on cellulose, modified cellulose, or cellulose derivatives
    • C09D101/08—Cellulose derivatives
    • C09D101/26—Cellulose ethers
    • C09D101/28—Alkyl ethers
    • C09D101/284—Alkyl ethers with hydroxylated hydrocarbon radicals

Definitions

  • the present invention relates to low-viscosity, hot water flocculable
  • cellulose ethers are referred to as the lowest viscosity products, the Höppler viscosity, measured 2.0% (absolutely dry) in water at 20 ° C, is not more than 50 mPas.
  • the processes used to break down cellulose ethers include oxidative degradation and degradation by high-energy radiation or microorganisms / enzymes.
  • US-A-2 912 431 describes a process in which hypohaiites, peroxides or periodates break down carboxymethyl celluloses in a mixture with aqueous alcohol at 40 to 80 ° C. with simultaneous bleaching.
  • DE-A-20 16 203 describes a process for breaking down cellulose ethers in which a largely dry powder with a maximum water content of 5% is mixed with a hydrogen peroxide solution and broken down at 50 to 150 ° C.
  • GB-B-953 944 reduces the viscosity of water-soluble, nonionic cellulose ethers in the dry or moistened state by reaction with H 2 O 2 at elevated temperatures.
  • the oxidative degradation of the cellulose ethers generally leads to the formation of numerous by-products.
  • US-A-1 943 461 the pre-ground cellulose ethers with dilute acids or their mixtures (concentration 0.5 to 5%, a multiple of the weight of the cellulose ether to be degraded) are in a closed pressure vessel for 20 to 60 minutes at 0.7 to 5.2 bar pressure and temperatures from 115 to 160 ° C reduced.
  • US-A-1 679 943 describes the degradation of cellulose ethers with different acid mixtures, neither a pressure vessel nor an elevated temperature being required. At room temperature, however, this results in unacceptably long reaction times, which can be in the range of several days.
  • EP-B-0 497 985 describes pulps with a low copper number, i.e. high ⁇ -cellulose content, washed, dried, ground and with a
  • aqueous HCl solution at a temperature of about 70 ° C.
  • the water content of the cellulose ether plays an important role in this process. On the one hand, it must not drop below 1% during drying, since excessive drying leads to cornification and yellowing of the products, but on the other hand, it must not be more than 5% during degradation, since substantial amounts of water promote gel formation in low-molecular cellulose ethers.
  • the resulting cellulose ethers have very low viscosities ( ⁇ 20 mPas, 2.0% at 20 ° C).
  • EP-A-0 210 917 There a cellulose ether powder containing 3 to 8% water is broken down with 0.1 to 1% by weight of an aqueous HCl solution at 40 to 85 ° C.
  • the degradation to low-viscosity, high-purity products can also be achieved by using HCI as a gas.
  • HCI as a gas.
  • Such methods are described, for example, in US-A-3,391,135 and US-A-4,061,859.
  • US-A-3 391 135 discloses a process for the production of cellulose ethers with solution viscosities of less than 10 mPas (2.0% at 20 ° C.) from higher viscosity cellulose ether powders with water contents less than 5% at 30 to 80 ° C. Excess HCl gas is removed and the cellulose ether is then neutralized by mixing in a weak base.
  • cellulose ethers are broken down as dry powders with a water content of 0.01 to 5% by weight with hydrogen halide at 15 to 80 ° C. and then neutralized by mixing in sodium bicarbonate or introducing ammonia gas.
  • the material obtained is bleached with sulfur dioxide gas, with which the degraded material is brought into contact after the depolymerization step.
  • cellulose ethers can be broken down into low-viscosity products with an initial viscosity of several hundred thousand mPas.
  • the bleaching stage downstream of the depolymerization enables the products to be lightened in color.
  • the hydrolytic degradation is functional group-neutral and gentle and can be used to manufacture low-viscosity products.
  • the cellulose ether to be degraded is in a larger dilution in an aqueous medium, losses in yield due to partial dissolution of the material can hardly be avoided.
  • the object of the present invention was therefore to provide a process for the depolymerization of cellulose ether which does not have the disadvantages of the prior art mentioned.
  • This object is achieved by a process for the depolymerization of hot water-flocculable cellulose ethers by hydrolytic degradation using acids, which is characterized in that the degradation is carried out at a temperature above the flocculation point of the cellulose ether as a concentrated, aqueous slurry.
  • cellulose ethers which can be flocculated with hot water can be used as cellulose ethers.
  • Alkyl celluloses such as e.g. Methyl, ethyl and propyl cellulose, as well as mixed ethers thereof, e.g. Hydroxyethylmethyl, hydroxypropylmethyl, ethyl hydroxyethyl and ethylmethyl cellulose.
  • cellulose ethers used for the degradation are in no way restricted. They can be prepared and worked up by all processes known to the person skilled in the art (Ullmann's Encyclopedia of Industrial Chemistry; Volume 9, “Celluloseether”, Verlag Chemie, Weinheim, 4th Edition 1975, p. 192 ff).
  • the degree of polymerization and the viscosity of the cellulose ethers to be used are likewise in no way restricted.
  • a cellulose ether should be used for the degradation, the degree of polymerization of which is not too far from is the degree of polymerization that is to be achieved by the depolymerization.
  • the process according to the invention produces low-viscosity cellulose ethers which have Höppler viscosities, measured 2.0% (absolutely dry) in water at 20 ° C. of ⁇ 50 mPas.
  • Suitable acids for hydrolytic degradation are mineral acids, but also strong organic acids and mixtures thereof. However, mineral acids are preferred.
  • Hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid are particularly preferably used as mineral acids. Mixtures of the same can also be used.
  • Trifluoroacetic acid Trifluoroacetic acid, acetic acid, formic acid, oxalic acid, phthalic acid, maleic acid and benzoic acid are preferably used as strong organic acids. Mixtures of the same can also be used.
  • the acid-catalyzed hydrolytic degradation is carried out above the flocculation point of the cellulose ether.
  • a temperature range from 70 to 105 ° C. is preferred.
  • the process according to the invention is also characterized in that the degradation is carried out as a concentrated slurry.
  • the weight ratio of water to cellulose ether is preferably at most 10: 1, particularly preferably at most 7: 1 and in particular at most 5: 1.
  • the use of the smallest possible amount of water as a suspending agent leads to very low losses in yield, which are generally caused by the dissolution of low-viscosity constituents.
  • additional oxidizing agents are added to the concentrated, aqueous slurry before, during and / or after the depolymerization in an acidic or neutral environment.
  • Hydrogen peroxide and its salts, other peroxo compounds, such as sodium peroxosulfate, perborates (also in combination with activators such as TAED), sodium chlorite, halogens, halogen oxides and other compounds used for bleaching are preferably used as oxidizing agents. Hydrogen peroxide (H 2 O 2 ) is particularly preferred.
  • the oxidizing agents are generally used in amounts of from 0.01 to
  • the addition of the oxidizing agent is also conceivable before or after the hydrolytic degradation by means of acids, but the addition in the course of the depolymerization is preferred.
  • the degradation and the additional lightening of the color by oxidation and / or by-product removal can either be carried out in one step, or else can be carried out successively, both in an acidic environment and after (partial) neutralization.
  • the degradation can be carried out both on the ready-made product and on moist raw goods with the usual moisture content. Since a subsequent drying and grinding is necessary to assemble the product, it is preferred to use moist raw materials for the breakdown, as is the case in production processes.
  • the degradation can be carried out, for example, instead of the last washing step with a partially reduced salt content, since excess salt from the conversion to the cellulose ether is also removed by the aqueous slurry. The result is products with an extremely low salt content.
  • the aqueous solutions of the degraded cellulose ethers generally have weakly acidic pH values due to the generation of acidic groups on the basic cellulose ether structure.
  • the pH of these solutions can be adjusted to a largely neutral pH of 5.5 to 8.0 by, after the depolymerization, the degraded cellulose ether for washing out the reaction by-products not with water but with an aqueous solution of at least one basic salt (such as Example sodium carbonate, sodium hydrogen carbonate, sodium sulfate, sodium hydrogen sulfate) is washed at a temperature above the flocculation point of the degraded cellulose ether.
  • An additional mixing step as described in other methods for setting a target pH, is omitted.
  • the base is distributed evenly and the cellulose ether can be dried and ground in one or more steps in the normal process.
  • the yields of the process described are generally between about 80% and 96%. Since in the aqueous work-up of cellulose ethers, depending on the viscosity, in As a rule between 3 and 8% washing loss occurs and the degradation can be carried out instead of a washing step, the yield losses are minimized.
  • An increase in the yield, especially in the case of products with a high flocculation point, can be achieved by increasing the decomposition temperature when carried out in a printing apparatus.
  • the viscosity of the resulting products can essentially be adjusted in a targeted manner via the amount of acid used, the reaction time and, if appropriate, the amount of additional oxidizing agent, and is very reproducible. Due to the uniform degradation with thorough mixing and distribution of the reactants, the products have almost uniform degrees of polymerization.
  • the process according to the invention makes it possible to produce cellulose ethers with a high purity and a high degree of whiteness. Particularly good results are achieved in the production of methylhydroxypropyl celluloses.
  • Another object of the present invention are therefore methyl hydroxypropyl celluloses with a Höppler viscosity, measured 2.0% (absolutely dry) in water at 20 ° C., preferably of ⁇ 50 mPas and particularly preferably ⁇ 5 mPas.
  • the degree of whiteness of methylhydroxypropyl celluloses with a viscosity in the range from 5 to 50 mPas is preferably above 60%, and of methylhydroxypropyl celluloses whose viscosity is ⁇ 5 mPas, preferably above 50% (basis: DIN standard 5033). Since the degree of whiteness depends, among other things, on the grain size distribution of the cellulose ether, the values given relate to products whose proportion of particles with a size of ⁇ 125 ⁇ m is a maximum of 50%, but preferably less than 10%.
  • the salt content of the cellulose ethers produced is preferably below
  • Methyl hydroxypropyl celluloses the proportion of methoxy groups in the range from 28 to 32% by weight and the proportion of hydroxypropyl groups in the range from 5 to 9% by weight, are particularly preferred.
  • the cellulose ethers described are particularly suitable for coating pharmaceuticals or seeds and for use in cosmetics, foods or in suspension polymerization.
  • the stated amounts of acid mean percentages by weight of concentrated HCl (37%), based on the amount of cellulose ether used.
  • the pore size has been filtered off and washed with a little boiling water in order to remove the partially considerably colored residues of suspension medium from the product.
  • the product is then dried and on a commercial
  • the grinding parameters are selected so that the resulting granulate has the following grain size distribution:
  • Table 1 Acid-catalyzed degradation of hot water-flocculable cellulose ether (MHPC) with and without additional oxidizing agent
  • OC 2 H 5.1% (air dry at 1.4% moisture content); water-moist raw material, dry content approx. 59%, starting viscosity before degradation (1.9%, absolutely dry): 176 000 mPas

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Biochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Wood Science & Technology (AREA)
  • Animal Behavior & Ethology (AREA)
  • Epidemiology (AREA)
  • Birds (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Molecular Biology (AREA)
  • Mycology (AREA)
  • Nutrition Science (AREA)
  • Food Science & Technology (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)

Abstract

La présente invention concerne des éthers de cellulose à faible viscosité, pouvant floculer dans l'eau chaude, de grande pureté et à haut degré de blanc. Cette invention concerne également leur procédé de production par dépolymérisation, au moyen d'une dégradation hydrolytique, à catalyse acide, éventuellement en présence d'un agent d'oxydation, ainsi que leur utilisation.
EP00960577A 1999-09-03 2000-09-01 Ethers de cellulose a faible viscosite, pouvant floculer dans l'eau chaude, leur procede de production par depolymerisation et leur utilisation Withdrawn EP1237931A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19941893A DE19941893A1 (de) 1999-09-03 1999-09-03 Niederviskose, heisswasser-flockbare Celluloseether, Verfahren zu deren Herstellung durch Depolymerisation sowie deren Verwendung
DE19941893 1999-09-03
PCT/EP2000/008538 WO2001018062A1 (fr) 1999-09-03 2000-09-01 Ethers de cellulose a faible viscosite, pouvant floculer dans l'eau chaude, leur procede de production par depolymerisation et leur utilisation

Publications (1)

Publication Number Publication Date
EP1237931A1 true EP1237931A1 (fr) 2002-09-11

Family

ID=7920586

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00960577A Withdrawn EP1237931A1 (fr) 1999-09-03 2000-09-01 Ethers de cellulose a faible viscosite, pouvant floculer dans l'eau chaude, leur procede de production par depolymerisation et leur utilisation

Country Status (6)

Country Link
EP (1) EP1237931A1 (fr)
JP (1) JP2003508597A (fr)
KR (1) KR20020033784A (fr)
DE (1) DE19941893A1 (fr)
MX (1) MXPA02002357A (fr)
WO (1) WO2001018062A1 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10117208A1 (de) * 2001-04-06 2002-10-10 Wolff Walsrode Ag Verfahren zur Herstellung von niederviskosen, wässrigen Celluloseetherlösungen
DE10141680B4 (de) * 2001-08-25 2004-02-26 Clariant Gmbh Verfahren zur Herstellung niederviskoser Celluloseether durch sauer-oxidativen Abbau von gemahlenen und getrockneten Celluloseethern
US8865432B2 (en) 2004-02-26 2014-10-21 Shin-Etsu Chemical Co., Ltd. Method for preparing cellulose derivatives having solubility improved
CN101001881A (zh) * 2005-08-22 2007-07-18 信越化学工业株式会社 溶解度提高的纤维素衍生物的制造方法
KR101404282B1 (ko) 2006-06-14 2014-06-05 다우 글로벌 테크놀로지스 엘엘씨 셀룰로오스 에테르의 평균 분자량 감소 방법
CN101855247B (zh) 2007-11-09 2013-03-20 联合碳化化学品及塑料技术公司 制备非常低粘度的纤维素醚的方法和产品
KR101971738B1 (ko) * 2012-12-11 2019-04-23 롯데정밀화학 주식회사 부분 중화법을 통한 초저점도 히드록시알킬 셀룰로오스의 제조방법
US9926385B2 (en) 2013-08-12 2018-03-27 Shin-Etsu Chemical Co., Ltd. Method for producing water-soluble cellulose ether having low degree of polymerization and method for producing film coating composition comprising same
WO2015105030A1 (fr) * 2014-01-10 2015-07-16 三菱瓦斯化学株式会社 Procédé de fabrication de cellulose
EP3212674B1 (fr) * 2014-10-31 2018-08-22 Dow Global Technologies LLC Procédé de préparation d'un ester d'un éther de cellulose
MX356115B (es) * 2014-10-31 2018-05-15 Dow Global Technologies Llc Proceso para producir un succinato de acetato de eter de celulosa.
DE102017223690A1 (de) 2017-12-22 2019-06-27 Se Tylose Gmbh & Co. Kg Oxidativer Abbau von Celluloseethern
JP7414685B2 (ja) 2020-10-22 2024-01-16 信越化学工業株式会社 解重合されたセルロースエーテルの製造方法

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Publication number Priority date Publication date Assignee Title
WO2000032637A1 (fr) * 1998-12-01 2000-06-08 The Dow Chemical Company Procede et appareil de fabrication d'ethers de cellulose

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US1943461A (en) * 1930-04-16 1934-01-16 Ici Ltd Cellulose ether and method of making same
JPS4841037B1 (fr) * 1964-10-26 1973-12-04
US4061859A (en) * 1976-06-14 1977-12-06 The Dow Chemical Company Viscosity reduction of cellulose derivatives
FI895708A0 (fi) * 1989-02-10 1989-11-29 Alko Ab Oy Vattenloeslig soenderdelningsprodukt.
DE69129839T2 (de) * 1990-08-24 1999-02-11 Shinetsu Chemical Co Beschichtungsbase für einen pharmazeutischen film und verfahren zur herstellung derselben
US5500124A (en) * 1991-12-06 1996-03-19 Hoechst Ag Process for the purifying working-up of reaction media and/or wash media obtained during preparation of cellulose ethers
DE4434280C2 (de) * 1994-09-26 1998-09-10 Clariant Gmbh Verfahren zur Herstellung von niedermolekularen Celluloseethern und ihre Verwendung als Überzugsmaterial für feste Dosiereinheiten

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Publication number Priority date Publication date Assignee Title
WO2000032637A1 (fr) * 1998-12-01 2000-06-08 The Dow Chemical Company Procede et appareil de fabrication d'ethers de cellulose

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See also references of WO0118062A1 *

Also Published As

Publication number Publication date
KR20020033784A (ko) 2002-05-07
WO2001018062A1 (fr) 2001-03-15
DE19941893A1 (de) 2001-03-08
MXPA02002357A (es) 2002-08-20
JP2003508597A (ja) 2003-03-04

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