EP1062247A1 - Verfahren zur herstellung von celluloseformiaten - Google Patents
Verfahren zur herstellung von celluloseformiatenInfo
- Publication number
- EP1062247A1 EP1062247A1 EP99966999A EP99966999A EP1062247A1 EP 1062247 A1 EP1062247 A1 EP 1062247A1 EP 99966999 A EP99966999 A EP 99966999A EP 99966999 A EP99966999 A EP 99966999A EP 1062247 A1 EP1062247 A1 EP 1062247A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cellulose
- substitution
- formate
- degree
- cellulose material
- 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- Withdrawn
Links
Classifications
-
- 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
- C08B3/04—Cellulose formate
-
- 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
- C08B3/16—Preparation of mixed organic cellulose esters, e.g. cellulose aceto-formate or cellulose aceto-propionate
Definitions
- the invention relates to a method for producing a cellulose derivative with formate substituents by reacting a cellulose material impregnated with excess alkali and / or alkaline earth metal solution with a formylating agent.
- Cellulose acetate with a degree of substitution (DS) between 1.5 and 2.9 is an important product for various industrial applications.
- the degree of substitution DS denotes the average number of hydroxyl groups which are esterified with acetyl groups per anhydroglucose unit of the cellulose.
- cellulose is always converted to triacetate in a first process step. The cellulose triacetate is then hydrolyzed to the desired degree of substitution (see Müller, F., Leusche, Ch., In "Kunststoff Handbuch” Vol. 3/1, p. 398, Hanser Verlag Kunststoff, Vienna 1992).
- acetylation is carried out with a deficit of acetylating agent or the acetylation is interrupted prematurely, no homogeneous, partially acetylated product is obtained, but essentially a mixture of cellulose triacetate and unreacted cellulose.
- the reason for this lies in the structure of the cellulose, which contains both amorphous and crystalline components. While the amorphous components are readily accessible to the acetylating agent, the crystalline components are difficult to access, which leads to an inhomogeneous reaction.
- An indicator of a homogeneous distribution of substituents in a partially acetylated cellulose acetate is its solubility in acetone.
- the pulps that are suitable for acetylation and are commercially available are high-quality pulps. They contain only relatively little hemicellulose (2 to 3% by weight) (see Müller, F., Leusche, Ch., In “Kunststoff Handbuch” Vol. 3/1, p. 402, Hanser Verlag, Kunststoff, Vienna 1992).
- a process is desirable in which less refined pulps, ie pulps with a higher hemicellulose content, can also be used. This would mean a significant cost saving because the pulp prices are relatively high and cellulose acetate consists of about 60% cellulose.
- Cellulose can be esterified directly with formic acid to partially substituted cellulose formate.
- the degree of substitution achieved depends on the reaction temperature, the water content of the starting materials and the type of pretreatment used
- the cellulose formates produced by these processes have no technical significance.
- DE 196 38 319 Cl relates to a process of the type described in the introduction. Then a cellulose starting material is swollen in alkali or alkaline earth metal solution, excess liquor is pressed off, the pressed cellulose is rinsed with alcohol and filtered off, and the alkali metal or alkaline earth metal cellulose obtained with formic acid, acetic anhydride, propionic anhydride, propionic anhydride or substituted butyric acid. The product is then filtered off, washed with water and dried.
- the cellulose ester obtained is in a concentration up to 11 wt .-% in dimethylacetamide, dimethyl sulfoxide or l-methyl-2-pyyrolidone with the addition of 1 to 3 wt .-% lithium chloride or dimethyl sulfoxide with the addition of 0.5 to 2 wt .-% % Magnesium chloride or dissolved in pure dimethyl sulfoxide.
- the solution thus obtained is spun by wet spinning in a coagulant. This procedure is used at
- cellulose starting material is reacted in formic acid and acetic anhydride until an acetone-soluble cellulose derivative has formed in the form of a mixed ester in which more than 7 formyl groups are present in all 24 carbon atoms in the cellulose.
- cellulose esters are produced in two stages, first treating cellulose with organic acid anhydrides in the presence of basic agents and then in the presence of compounds which react with mineral acids with organic or inorganic esterification agents. According to a precise embodiment, it is first prepared with alkalis acted cellulose reacted with acetic anhydride and obtained in this way a partially acetylated material.
- DE-PS 874 440 relates to a process in which solutions of cellulose triacetates with 61 to 61.5% bound acetic acid in formic acid
- the invention is therefore based on the object of an improved method for
- this object is achieved by a process for the production of a cellulose derivative with formate substituents by reacting a cellulose material impregnated with excess alkali and / or alkaline earth metal solution with a formylating agent, the cellulose material impregnated with excess base having a formylating agent up to a degree of substitution (DS) of at least about 0.5 is implemented.
- a process for the production of a cellulose derivative with formate substituents by reacting a cellulose material impregnated with excess alkali and / or alkaline earth metal solution with a formylating agent, the cellulose material impregnated with excess base having a formylating agent up to a degree of substitution (DS) of at least about 0.5 is implemented.
- DS degree of substitution
- the above object is also achieved by a process for producing a cellulose derivative with formate substituents by reacting a cellulose material treated with excess alkaline solution with a formylating agent, a cellulose material pretreated with ammonia having a formylating agent to a degree of substitution (DS) of at least about 0.1 1 is implemented. It is particularly preferred here that the cellulose material pretreated with ammonia is a cellulose material coded for an ammonia-exp.
- Cellulose starting materials which have been activated in a manner known per se can be used with particular advantage. Activation is understood to mean that they are more accessible to chemical reaction materials, which is on the one hand in their loosened physical form and on the other hand through chemical activation. Activation by treatment with ammonia has proven to be particularly effective. In this case, an activated cellulose starting material that has been activated by the ammonia explosion known in the prior art is particularly preferred. In this regard, reference is made to WO 96/30411. In this activation, the cellulose is brought into contact with liquid ammonia at an initial pressure which is higher than atmospheric pressure and at a temperature of at least about 25 ° C., the amount of liquid ammonia being at least sufficient to wet the surface of the cellulose material.
- Bases which are used in the impregnation step according to the invention are either liquid or are present as a solution, preferably as an aqueous solution.
- the bases or their solutions are capable of swelling the cellulose or the cellulose material, ie they can penetrate into the crystalline areas of the cellulose and in this way activate the cellulose or make it more accessible to reagents.
- the activation state is further maintained or preserved by the formylation to a DS of more than about 0.1, in particular more than about 0.3. It is believed that the low substituent density formyl groups act as "spacers" that prevent recrystallization of the cellulose chains when the base is consumed or otherwise removed by the reaction.
- Sodium hydroxide solution in particular aqueous sodium hydroxide solution, preferably a concentration of at least 20%, or liquid ammonia is preferably used as the base for impregnating the cellulose. According to a preferred embodiment of the method according to the invention
- Cellulose is first impregnated with an excess of base and then the base is removed again to a molar ratio of base: AHG (anhydroglucose units) of less than about 2.5, in particular less than about 1.
- AHG anhydroglucose units
- An "excess of base” means that the base or its solution must at least completely wet the surface of the cellulose.
- the use of an excess of base facilitates the homogeneous penetration of the cellulose with base. As stated, the base is then largely removed to minimize the formation of by-products from the reaction of the base with the formylating agent.
- hemicelluloses are soluble in sodium hydroxide solution, in particular in the concentration range preferred in the process according to the invention, and can be separated off by pressing off insoluble pulp (cf. K. Götze, chemical fibers according to the viscose process, 3rd edition, Springer-Verlag, Berlin, Heidelberg, New York, 1967). It is therefore a great advantage of the process according to the invention that hemicelluloses and lignin are separated off in the course of the production of the desired cellulose formates and thus cannot have a disruptive effect on the further processing of the process product obtained.
- the undesired accompanying substances can therefore be separated from the base in a suitable manner, after which it can be reused.
- the base can therefore be circulated while the accompanying cellulose substances are discharged.
- the cellulose accompanying substances in turn can then be worked up and put to a useful use.
- Excess base can be removed by mechanical pressing of the impregnated cellulose.
- Alternatively or preferably in addition to pressing the impregnated cellulose can be rinsed with a water-miscible polar organic solvent.
- the solvent is preferably selected from monohydric, dihydric or trihydric G-Gt alcohols and amines.
- the monohydric alcohol is preferably methanol or ethanol and the dihydric alcohol is ethylene glycol.
- Reaction with formic acid sets the cellulose formate in a particularly reactive state.
- the product is obtained in a heterogeneous phase.
- the formic acid is removed by simple filtering and then simply dried.
- the formic acid can also be washed out. Regardless of this isolation step, the desired homogeneous and amorphous product is obtained.
- formate substituents can be indirectly demonstrated by the fact that on the one hand formate is soluble at a degree of substitution (DS) greater than 1.1, on the other hand aceto formates, produced directly, are soluble in acetone with a total degree of substitution of 2.5.
- DS degree of substitution
- the process product obtained according to the invention in the form of the cellulose formate with a degree of substitution (DS) of more than about 0.5 can after washing with
- Water and drying can be stored for a long time without any problems under the influence of large amounts of moisture without losing its desirable properties, in particular the particular reactivity with other derivatizing agents.
- the cellulose formate obtained according to the invention has a degree of substitution (DS) of more than about 0.5 in process A.
- DS degree of substitution
- the extent to which the reaction of the formation continues depends on the purpose for which the result is obtained Cellulose formate should finally be fed.
- One example is the further one
- the cellulose formate is fibrous in structure and, according to X-ray diffraction analysis, is completely decrystallized. It shows a uniform reactivity and is therefore a suitable substrate for further process steps in which the cellulose acetoformate with the desired degree of substitution (DS) is obtained directly.
- the fibrous structure is shown by the fact that it does not differ from cellulose in terms of appearance.
- the cellulose formate initially formed it is generally advantageous for the cellulose formate initially formed to have a degree of substitution (DS) of more than about 0.5, in particular more than 0.8.
- a degree of substitution of 3 should, however, be ruled out as far as possible since the desired derivatization with, for example, an acetylating agent is then not possible in a simple process. This would have to be a kind of "transesterification", which is less energy-efficient and time-consuming.
- the cellulose formate obtained can be subjected to various reactions.
- This can be, for example, an acylation, in particular an acetylation, preferably with acetic anhydride or a propionation, preferably with propionic anhydride, a derivatization with dicarboxylic anhydride, such as in particular with maleic anhydride, phthalic anhydride or succinic anhydride, an esterification with lactide, an alkylation and a derivatization Epoxides, such as propylene oxide or ethylene oxide.
- the product according to the invention is particularly advantageous in the further reaction with an acetylating agent for the production of a cellulose acetoformate and, if appropriate, subsequent deformylation to obtain an acetone-soluble cellulose acetate in particular.
- an acetylating agent for the production of a cellulose acetoformate and, if appropriate, subsequent deformylation to obtain an acetone-soluble cellulose acetate in particular.
- the further derivatization especially with an acetylating agent, must be done lytically.
- An example is the reaction with an acetylating agent below
- Acetic anhydride in particular is used as the acetylating agent and sulfuric acid is preferably used as the catalyst.
- sulfuric acid is preferably used as the catalyst.
- Catalyst concentration can be reduced very much compared to the prior art due to the activation of cellulose (high reactivity).
- the processes A and B according to the invention show numerous advantages: For example, the technology of mercerization, i.e. Treatment of cellulose with base, well established, proven and inexpensive to operate. Corresponding systems are used on a large scale worldwide in the production of viscose or cellulose ether.
- an amorphous cellulose formate with a low degree of substitution (DS) is first produced. Its further implementation to
- Cellulose acetoformate with the desired degree of substitution (DS) with respect to the acetylating agent takes place without the problems which arise in heterogeneous acetylation due to the crystalline proportion of cellulose, such as inhomogeneous distribution of substituents and low product uniformity.
- the formylation takes place at room temperature or slightly elevated temperatures.
- Cellulose formates are characterized by a largely homogeneous distribution of substituents, which leads to excellent solubility in acetone.
- DP molecular weight
- high DP values can be cases are of particular value, for example where high tensile strength values are required of the corresponding fibers.
- cellulose ether materials where one also speaks of "high DP" cellulose ethers.
- the cellulose formates are soluble in dimethylacetamide with 1.5% by weight lithium chloride additive (solubilizer) at 20 ° C. up to a content of at least 8% by weight. This illustrates the good activation through decrystallization and homogeneous distribution of formate substituents.
- FIG. 1 The complete decrystallization is illustrated in FIG. 1.
- the X-ray diagrams of Examples 1, 2, 3 and 4 are shown in comparison to the starting material.
- cellulose-0.5-formate (Example 3) are suspended in glacial acetic acid (99%) at 60 ° C. in a thermostattable reaction vessel. After 10 minutes, 116 g of acetic anhydride (1. 1 mol) are added. After 5 minutes, 10 ml of a 1 wt. % sulfuric acid solution in glacial acetic acid and stirred for a further 45 minutes at 60 ° C, the reaction mixture being homogenized. After precipitation of the cellulose acetoformate in water, repeated washing and drying at 60 ° C., 126 g of cellulose acetoformate with a DS of 2.5 are obtained.
- the cellulose-2,5-acetoformate is produced analogously to Example 22.
- 80 g of cellulose-0.5-formate (Example 1) are used, which is esterified with 130 g of acetic anhydride (1.21 mol) for 45 minutes at 60 ° C.
- 129 g of cellulose acetoformate with a DS of 2.5 are obtained.
- the product is stirred for 10 minutes at 40 ° C. in 500 ml of buffer solution (pH 9), filtered off, washed neutral and dried.
- 117 g of cellulose-2,2-acetate are obtained.
- the product is completely soluble in 1050 ml acetone.
- the solution is filtered and can be processed into cellulose acetate products.
- the cellulose-2,5-propioformate is produced analogously to Example 22.
- 80 g of cellulose-0.5-formate (Example 3) are used, which is esterified with 143 g of propionic anhydride (1.1 mol) at 50 ° C. for 50 minutes.
- 143 g of propionic anhydride (1.1 mol) is esterified with 143 g of propionic anhydride (1.1 mol) at 50 ° C. for 50 minutes.
- 135 g of cellulose propioformate with a DS of 2.5 are obtained.
- the product is completely soluble in 1200 ml acetone.
- the solution is filtered and can be made into cellulose-2,5-propioformate products.
- Example 21 The product from Example 21 is stirred for 10 minutes at 40 ° C. in 500 ml of buffer solution (pH 9), filtered off, washed neutral and dried. 125 g of cellulose-2,0-propionate are obtained. The product is soluble in acetone and can be processed into cellulose propionate products.
- Examples 23 and 24 Esterification with maleic anhydride and succinic anhydride
- the reaction is carried out analogously to Example 22.
- 108 g of maleic anhydride or 110 g of succinic anhydride are used as the anhydride.
- Cellulose mixtures esters are obtained, a DS of 2.3 resulting from the esterification with maleic anhydride and a DS of 2.1 in the case of the succinic anhydride.
- Example 25 Partial esterification of cellulose with formic acid and influence of various parameters
- the formic acid ester of cellulose occupies a special position among the cellulose esters. Only cellulose formates can be produced without the action of the pure carboxylic acid without catalysts. Anhydrous formic acid causes swelling and partial esterification of the cellulose. Higher degrees of substitution can be achieved with the help of catalysts such as hydrogen chloride or zinc chloride.
- reaction temperature results in an increase in the degree of substitution with a shorter reaction time (cf. PF09, PF 10). Accordingly, the reaction rate slows down at low temperature.
- Example 25.3. Influence of the water content of cellulose
- the esterification of cellulose should be carried out with the exclusion of water.
- the influence of the H 2 O content in formylation is not as serious as in acetylation, for example, in which the reagent (acetic anhydride) reacts with water, an increased water content also has a reaction-inhibiting effect on formate formation.
- the following table shows the relationship between the drying method or the water content of the pulp and the degree of substitution of the cellulose formate.
- a high NH or NaOH content has a negative effect on the degree of substitution when the iate is formed.
- the addition of acid creates ammonium or
- Formic acid is the strongest carboxylic acid; it can therefore be assumed that the acid treatment - especially at higher temperatures - leads to a reduction in the average degree of polymerization of the polymer.
- the measurement of the Cuoxam-DP values of some formate samples confirms this assumption.
- the degradation of the cellulose caused by the acid can possibly be compensated for by milder acetylation conditions (elimination of the long activation by glacial acetic acid / sulfuric acid mixture and lower catalyst concentration).
- the partially esterified cellulose formates produced can be converted into acetic formate mixed esters in glacial acetic acid with acetic anhydride.
- the increased reactivity of the formate can on the one hand shorten the time-consuming activation in glacial acetic acid, and on the other hand the amount of sulfuric acid required as a catalyst can be reduced.
- acetone-soluble mixed esters with the properties of 2,5-acetates obtained by hydrolysis of triacetates are obtained.
- the NaOH-containing pulp was pressed in a suction filter (weight after pressing: 101.5 g) and taken up with 400 ml of freshly prepared 4% sodium hydroxide solution and stirred for 30 minutes. The pulp was again freed from the sodium hydroxide solution by pressing (weight: 47.6 g), 300 ml of methanol were added (liquor ratio 1: 6) and the mixture was stirred for 4 minutes. After filtering off the methanol, 46.0 g of Na cellulose (NaOH content: 3.2% by weight) were obtained. 20.1 g of this activated cellulose were mixed with 100 ml (liquor ratio: 1: 5) concentrated formic acid (99.6%) and mixed in a sealed bottle for 24 hours on the roller bench.
- the pulp mixture was poured into 600 ml of cold water, filtered and washed acid-free with 3 l of water.
- the cellulose formate was then washed with 400 ml of methanol, pressed and dried at 60 ° C. for 3 hours.
- the degree of substitution of the formate was determined to be 0.28.
- 2.0 g of the partially formylated product were mixed with 40 ml of glacial acetic acid and left to swell for one hour.
- the mass was transferred to a double-walled beaker at 60 ° C. and mixed with 6 ml of acetic anhydride.
- the reaction was carried out by adding 1 ml of a 1% solution of conc. Sulfuric acid started in glacial acetic acid.
- the stirring speed was 400 rpm.
- the mixture homogenizes after a few minutes, and an almost clear solution is formed after 50 minutes.
- the reaction was stopped after 55 minutes by adding 0.5 ml of a 2% sodium acetate solution in 60% acetic acid.
- the product was precipitated by pouring the solution into 500 ml of ice water, washed acid-free with water and methanol and dried at 60 ° C. for 6 hours.
- the virtually completely acetone-soluble product was dissolved in acetone for purification, filtered, precipitated in water, washed with methanol and dried. 2.2 g of a pure white, completely acetone-soluble product were obtained.
- the acetylations were carried out as follows: 2.0 g of dry cellulose formate are mixed with 40 ml of glacial acetic acid and the mixture is left to swell for 1 hour. The mixture is transferred to a double-walled beaker at 60 ° C. and mixed with 6.0 ml of acetic anhydride. The reaction is started by adding 1 ml of catalyst acid (1% by weight of H2SO4 in glacial acetic acid). It is stirred with the help of an IKA stirring motor at 400 rpm. The product is worked up by precipitating the product in water, washing with water and methanol and finally drying.
- the mixed esters obtained from PF03 and PF04 result in "solutions" in acetone which can be filtered through a G2 glass filter frit, but which have a very high gel content in the GPC spectrum to designate "partially soluble".
- the substances were characterized by recording IR spectra (KBr pellet in the formate, film on NaCl with an acetone-soluble mixed ester).
- the mixed ester GK-Ac27 was characterized by gel permeation chromatography.
- Figures 5 and 6 relate to the mixed ester GK-Ac27 and a reference 2,5-acetate (Fluka). The spectra are almost identical.
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Biochemistry (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19859970 | 1998-12-23 | ||
DE19859970 | 1998-12-23 | ||
PCT/EP1999/010321 WO2000039167A1 (de) | 1998-12-23 | 1999-12-22 | Verfahren zur herstellung von celluloseformiaten |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1062247A1 true EP1062247A1 (de) | 2000-12-27 |
Family
ID=7892605
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP99966999A Withdrawn EP1062247A1 (de) | 1998-12-23 | 1999-12-22 | Verfahren zur herstellung von celluloseformiaten |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1062247A1 (de) |
AU (1) | AU2285500A (de) |
WO (1) | WO2000039167A1 (de) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1886427B (zh) * | 2003-11-28 | 2012-05-23 | 伊士曼化工公司 | 纤维素共聚体和氧化方法 |
JP6003080B2 (ja) * | 2011-02-21 | 2016-10-05 | 三菱化学株式会社 | セルロース繊維およびセルロース繊維の製造方法 |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE498157C (de) * | 1925-06-04 | 1930-05-19 | Plumba Mij Tot Exploitatie Van | Verfahren zur Herstellung kuenstlicher Gebilde, insbesondere von Kunstseide |
FR780775A (fr) * | 1934-11-25 | 1935-05-03 | Procédé de préparation et de traitement de formiate de cellulose | |
FR2736356A1 (fr) * | 1995-07-03 | 1997-01-10 | Medev Bv | Procede d'obtention d'une solution de formiate de cellulose par impregnation puis malaxage de plaques de cellulose |
DE19638319C1 (de) * | 1996-09-19 | 1998-06-10 | Inst Textil & Faserforschung | Verfahren zur Herstellung von Celluloseformiaten, Celluloseacetaten, Cellulosepropionaten und Cellulosebutyraten mit Substitutionsgraden von 0,1 bis 0,4 und mit verbesserten Löseeigenschaften und ihre Verwendung zur Herstellung von Celluloseregeneratprodukten |
DE19646213C2 (de) * | 1996-11-08 | 1999-02-18 | Rhodia Acetow Ag | Verfahren zur Herstellung von Cellulosederivaten |
FR2762603B1 (fr) * | 1997-04-25 | 1999-07-16 | Rhodia Ag Rhone Poulenc | Cellulose reactive et procede de fabrication de cette cellulose |
-
1999
- 1999-12-22 EP EP99966999A patent/EP1062247A1/de not_active Withdrawn
- 1999-12-22 WO PCT/EP1999/010321 patent/WO2000039167A1/de not_active Application Discontinuation
- 1999-12-22 AU AU22855/00A patent/AU2285500A/en not_active Abandoned
Non-Patent Citations (1)
Title |
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See references of WO0039167A1 * |
Also Published As
Publication number | Publication date |
---|---|
AU2285500A (en) | 2000-07-31 |
WO2000039167A1 (de) | 2000-07-06 |
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