DE102004035870A1 - Process for the preparation of aminoalkyl group-containing polysaccharides and polysaccharide derivatives - Google Patents

Abstract

The invention relates to a process for the preparation of aminoalkoxylgruppenhaltiger polysaccharides and polysaccharide derivatives, wherein DOLLAR A a) a polysaccharide or polysaccharide in a mixture of a water-miscible aprotic solvent and water dispersed and DOLLAR A b) alkalized the polysaccharide or polysaccharide derivative with an inorganic base and DOLLAR A c) during the alkalization sets the amount of water used in the range between 1 and 55 moles of water per Anhydroglycoseeinheit the polysaccharide or polysaccharide derivative and DOLLAR A d) then carrying out an amination with an etherifying reagent at optionally elevated temperature and then DOLLAR A e) optionally neutralized and DOLLAR A f) the reaction product is filtered off, washed and then optionally dried and ground. DOLLAR A Another subject of the invention are amino group-containing polysaccharide derivatives prepared in this way with a total degree of substitution.

Description

The The invention relates to a process for the preparation of aminoalkylgruppenhaltiger Polysaccharides and polysaccharide derivatives by etherification free Hydroxyl groups of polysaccharides or polysaccharide derivatives and the aminoethyl group-containing polysaccharides or polysaccharide derivatives even.

cationic and amino group-containing polysaccharides can be widely used, e.g. as a paper aid, as a chelating agent and flocculant. In particular, chitosan, 2-amino-2-deoxy-cellulose, finds wide uses, among others as acid-stable Thickener in cosmetic preparations. The extraction of this natural Polysaccharides, however, is a laborious process, resulting in high yields Prices of products reflects. The high price is so far a broad application of these polysaccharides and polysaccharide derivatives opposite.

So far known process for the preparation of amino-containing polysaccharides or polysaccharide derivatives have the disadvantage that only one small part of the aminating reagents used to the polysaccharide or polysaccharide derivative. Therefore, a corresponding surplus These reagents can be used to high degrees of substitution achieve (US-A 2 623 042).

In DE-A 1 946 722 (Henkel) proposes cellulose or cellulose derivatives with small amounts of organic solvents in a kneader e.g. react with diethylaminoethyl chloride. Kneaders consist of e.g. from a double-hollowed Kneading chamber, in the two mutually repellent kneading blades rotate and capture almost the entire kneading space.

Overall, high compressive, tensile and shear forces and thus strong friction prevail in the kneaded by an alternate approach and removal of the blade surfaces to and from each other. Due to the high stress of the polysaccharide due to the high compressive, tensile and shear forces can occur unwanted chain degradation. Kneaders are characterized by high investment costs, based on the small reactor volume. In contrast, stirred tanks or reaction mixers with a capacity of a few 10 m ^{3 are} comparatively inexpensive to produce.

The Handling associated with the described method high-viscosity If necessary, sticky reaction mixtures is problematic, since these for Part of sticky masses are not pumped or pneumatically conveyed can. The cleaning of the compacted mass is also difficult because the washing liquid not easily penetrate into the interior of the compacted mass can.

• • mit einer hohen Ausbeute, bezogen auf das Veretherungsreagenz (mit Veretherungsreagenz ist hier das Reagenz zur Übertragung der Aminoalkylgruppe gemeint (Aminierung))
• • in kostengünstigen weit verbreiteten Aggregaten wie z.B. Rührreaktoren und Reaktionsmischern

herzustellen.The object of the present invention was therefore to provide an economical process which allows aminoalkyl-containing polysaccharides and derivatives

• With a high yield, based on the etherification reagent (with etherifying reagent is meant here the reagent for the transfer of the aminoalkyl group (amination))
• • in low cost widely used aggregates such as stirred reactors and reaction mixers

manufacture.

• a) ein Polysaccharid oder Polysaccharidderivat in einem Gemisch aus einem wassermischbaren aprotischen Lösungsmittel und Wasser dispergiert und
• b) das Polysaccharid oder Polysaccharidderivat mit einer anorganischen Base alkalisiert und
• c) während der Alkalisierung die eingesetzte Menge Wasser im Bereich zwischen 1 und 55 mol Wasser pro Anhydroglycoseeinheit des Polysaccharids oder Polysaccharidderivates einstellt und
• d) anschließend eine Aminierung mit einem Veretherungsreagenz bei gegebenenfalls erhöhter Temperatur durchführt und dann
• e) gegebenenfalls neutralisiert und
• f) das Reaktionsprodukt abfiltriert, wäscht, gegebenenfalls trocknet und mahlt.

The invention therefore provides a process for the preparation of aminoalkylgruppenhaltiger polysaccharides and polysaccharide derivatives, characterized in that

• a) a polysaccharide or polysaccharide derivative dispersed in a mixture of a water-miscible aprotic solvent and water and
• b) the polysaccharide or polysaccharide derivative alkalized with an inorganic base and
• c) during the alkalization the amount of water used in the range between 1 and 55 moles of water per Anhydroglycoseeinheit the polysaccharide or polysaccharide derivative sets and
• d) subsequently carrying out an amination with an etherifying reagent at optionally elevated temperature and then
• e) optionally neutralized and
• f) the reaction product is filtered off, washed, optionally dried and ground.

Surprisingly, without increased technical complexity in simple stirred reactors with egg In the solvent system, which consists of a water-miscible aprotic solvent and water in certain proportions, higher yields are achieved than in other known to the expert protic or water-immiscible solvents and solvent mixtures.

DS_theor.

= theorethisch möglicher DS, errechnet sich aus dem molaren Verhältnis von Veretherungsreagenz zu Anhydrozucker

DS_gem.

= gemessener DS, errechnet sich aus der Formel

M_PS

= Molekulargewichtsanteil einer Monomereinheit der Polysaccharids oder Polysaccharidderivates in g/mol

%N

= gemessener Stickstoffwert in Gew.-%. bezogen auf trockenes Produkt

M_Ve

= Molekulargewicht des Veretherungsreagenzes in g/mol

The yield is calculated according to the formula mentioned in EP-A 0 310 787: Yield (in%) = DS theor. / DS gem.

DS _theor.

= theoretically possible DS, is calculated from the molar ratio of etherification reagent to anhydro sugar

DS _acc.

= measured DS, calculated from the formula

M _PS

= Molecular weight fraction of a monomer unit of the polysaccharide or polysaccharide derivative in g / mol

% N

= measured nitrogen value in wt .-%. based on dry product

M _Ve

= Molecular weight of the etherifying reagent in g / mol

Thus, at a nitrogen content of 5.35 wt.%, A diisopropylaminoethylcellulose results

mit Ag = Aktivgehalt, bezogen auf die gesamte Trockenmasse in %However, this formula provides only exact values when the nitrogen content refers only to the amino group-containing polysaccharide. However, the values given after nitrogen determination (according to Kjeldahl) refer to the total mass, optionally corrected for the moisture. A more accurate DS _gem. is calculated when the nitrogen value is related to active content, ie the measured nitrogen content is corrected for the remaining acids and salts:

with Ag = active content, based on the total dry matter in%

in the The meaning of this invention is a water-miscible aprotic solvent in a mixture with water in the ratio which according to the invention during the Reaction is used, no phase separation at room temperature. The invention used water-miscible aprotic solvent exhibits no hydroxyl or amino groups that react with the etherifying reagent can react.

Preferred water-miscible aprotic solvents are open-chain or cyclic ethers of the general formula R _a -OR _b -R _c .

In this formula mean
R _a and R _{c are} independently branched, linear or cyclic alkyl or aryl, preferably R _a = R _c = methyl or ethyl and
R _b = (C _n H _2n O) _m with n = 2-4 and m = 0-3.

cyclic Ethers, e.g. Dioxane, can also be used.

Especially preferred ethers are cyclic or open chain ethers of 2-10 Carbon atoms and 1-3 oxygen atoms, most preferably the ether is non-cyclic, especially dimethoxyethane is used. Non-water-miscible ethers, e.g. Diethyl ether or methyl tert-butyl ether are not suitable.

In a further preferred embodiment, open-chain or cyclic compounds of the type R _a SO ₂ R _c , for example tetrahydrothiophene-1,1-dioxide (sulfolane) are used.

polysaccharides are preferably from plants or microorganisms or their components won natural Polysaccharides such as e.g. Dextran, pullulan, guar, and cellulose. Preferably, cellulose is used. Polysaccharides, the carboxylic acid or sulfonic acid included, e.g. Xylans, xanthan gum and carrageenan may also be be used.

Polysaccharide derivatives are derivatives of polysaccharides, especially hydroxyethyl, hydroxypropyl, methyl and ethyl polysaccharides, and polysaccharides substituted with these substituents. Particularly preferred are methyl cellulose, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl hydroxypropyl cellulose and ethyl hydroxypropyl cellulose. The total degree of substitution of these derivatives, if it is a cellulose ether, is preferably between 0.1 and 4, more preferably between 0.5 and 3. The average degree of substitution of alkyl substituents (DS _alkyl ) is between 0 and 2.5, more preferably between 0 and 1.7. The molar degree of substitution of hydroxyalkyl substituents (MS _hydroxyalkyl ) is between 0 and 3.5, more preferably between 0 and 2.5.

Prefers is a polysaccharide derivative, a water-insoluble cellulose ether or a cellulose ether with a thermal flocculation point used in water.

Suitable etherifying agents are compounds of the general formula X- (CH ₂ ) _n -NR ₁ R ₂ in which
X is a leaving group, preferably chlorine, bromine, iodine or a sulfonic acid radical R'SO ₃ , where R 'is an aromatic or aliphatic radical, for example para-toluyl or methyl,
X is preferably chlorine and
n must be at least 2
the radicals R ₁ and R ₂ independently of one another are aliphatic or branched or cyclic, optionally substituted by hetero atoms, alkyl or aryl substituents or H. Two radicals R ₁ and R ₂ can form a ring together with the nitrogen.

Examples of etherifying reagents to be used according to the invention are N-2-chloroethyldiisopropylamine, N-2-chloroethyldiethylamine, N-3-chloropropyldiethylamine, N-2-chloroethyldimethylamine and N-2-chloropropyldimethylamine. The radicals R ₁ and R ₂ may form a cyclic radical together with the nitrogen. Examples of etherification reagents used according to the invention, in which two radicals R ₁ and R ₂ form a ring together with the nitrogen, are N-2-chloroethylpyrrolidine, N-2-chloroethylpiperidine and N-2-chloroethylmorpholine. The etherifying reagents may be used in the form of the ammonium salts, eg, preferably a hydrochloride. Both the solid and a solution of, for example, 65% or 50% by weight in water or other solvent may be used.

Prefers N-2-chloroethyl-diisopropylamine hydrochloride and N-2-chloroethyl-diethylamine Hydrochloride used.

Per mol of anhydroglucose are about 0.1-3 mol, preferably about 0.3 2 mol, particularly preferably about 1 to 2 mol of etherifying agent used, when cellulose is used as starting material.

If a cellulose derivative is used, then 0.01 to 1.5 mol, preferably 0.1 to 1 mol, more preferably 0.1 to 0.8 mol of etherifying reagent per mole of anhydroglucose.

The Polysaccharide or polysaccharide derivative is preferred before addition of the etherifying reagent with an inorganic base is preferred an alkali or alkaline earth metal hydroxide, more preferably sodium hydroxide, touched, so that alkali cellulose can form. The order of addition but it can also be the other way around. In this case, the education takes place the alkali cellulose in situ instead.

The Base can be added in solid form or in the form of a solution become. Be exclusive solid bases, it may be necessary to add some water, as a certain amount of water during alkalization in the System must be present.

For example, for sufficient alkalization of cellulose, at least 1 mole of water should be added per mole of anhydroglucose, preferably at least 5 mole of water per mole of anhydroglucose, especially before at least 10 moles of water per mole of anhydroglucose must be present.

All in all should be less than 55 mol, preferably less than 45 mol, especially preferably used less than 35 mol of water per mole of anhydro sugar become. More water leads to form by-products and reduce the yield.

If the free amine is used, may arise during the etherification Acid through the amino group are bonded. However, it should be preferred at least 0.5 equivalents Base per mole of etherifying agent are used, particularly preferred at least 0.8 equivalents, to achieve a sufficient reaction rate.

at the most should be 1.5 equivalents Base are used per mole of etherifying reagent, preferably at most 1.2 mol and in a particularly preferred embodiment 1-1.1 mol.

The Base quantity must be increased accordingly when the etherifying reagent is in the form of an ammonium salt e.g. is used as the hydrochloride. Then at least additionally an equimolar amount, based on the ammonium salt, may be added to base to form the amine, e.g. from the hydrochloride, release.

The reaction is carried out in the presence of a water-miscible aprotic solvent in a stirred vessel or reaction mixer. The reaction can be carried out in a stirred vessel if the ratio of polysaccharide to slurry (slurry = aprotic water-miscible solvent + water) is 1:50 to about 1:10, preferably about 1:25 to 1:13 parts by weight. At higher ratios of up to about 1: 4 parts by weight of the approach may be harder to stir. In this case, a reaction mixer can be used. These are, for example, under the name All In One Reactor ^® by the company. Draiswerke, Mannheim or under the name Druvatherm ^® reactor. By the company Gebr. Lödige Ma mechanical engineering, Paderborn, offered. These mixers generally consist of a horizontally arranged, mostly cylindrical mixing chamber. This is a wave, which is provided with eg paddle or pflugscharförmigen mixing elements. If the shaft rotates, particles are ejected from the bed of mixed material and swirled and mixed in the space above the mix. The mixer may optionally be provided with further internals, such as so-called cutter heads or nozzles. [Karl Sommer in: "Mixing of Solids, 3. Designs of Solid - Solid Mixers, 3.3 Paddle Mixers", Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH Verlag GmbH & Co. KgaA, 2002. DOI: 10.1002 / 14356007. b02_27, Article Online Posting Date: June 15, 2000]

It It is not known why the reaction with aminoalkyl derivatives in a mixture of a water-miscible aprotic solvent and a certain amount of water in significantly better yields extends than in other solvents.

The Reaction is preferred at temperatures from 40 ° C to about 90 ° C, especially preferably 60 ° C up to about 75 ° C carried out. The reaction time depends from the reactor, the type of polysaccharide or derivative and the amount of aminoalkyl derivative used and is preferably from 30 minutes to about 4 hours.

To In the reaction the product is e.g. by filtration of salts and By-products are released. If necessary, before or after filtration neutralized. The filter cake is washed with a suitable washing medium washed. As preferred washing media have in addition to the water-miscible aprotic solvents e.g. acetone and their mixtures with water proven. frequently can also first be cleaned with water and then with an organic solvent. However, a suitable washing medium, depending on the nature of the Product and the Nebenprudukte be selected by appropriate experiments. But it is also possible not to remove the by-products and the product in uncleaned Form for to use technical applications.

The isolated from the reaction medium and optionally purified product is dried and ground. Can do this commercial Devices are used.

With the method according to the invention can amino group-containing polysaccharides and derivatives in simple, far disseminated plants and produced in high yield.

• a) Substituenten vom Typ -(CH₂)_n-NR₁R₂ enthalten, worin n mindestens 2 ist und die Reste R₁ und R₂ unabhängig voneinander aliphatische oder verzweigte oder zyklische, gegebe nenfalls mit Heteroatomen substituierte Alkyl- oder Aryl-Substituenten oder H bedeuten oder zwei Reste R₁ und R₂ gemeinsam mit dem Stickstoff einen Ring bilden können und
• b) Alkylsubstituenten vom Typ R₃ enthalten, wobei bevorzugt R₃ = -(CH₂)_m-CH₃ mit m = 0-3 und einem DS > 0,1 ist und
• c) einen Gesamtsubstitutionsgrad (Summe der einzelnen Substitutionsgrade) der Substituenten -(CH₂)_n-NR₁R₂ und R₃, bestimmt aus dem Stickstoffgehalt [für Substituenten -(CH₂)_n-NR₁R₂] bzw. nach Zeisel-Spaltung [für Substituenten R₃], zwischen 0,8 und 2 pro Anhydroglucoseeinheit aufweisen.

Another object of the invention are therefore amino group-containing polysaccharide derivatives

• a) substituents of the type - (CH ₂ ) _n -NR ₁ R ₂ contain, wherein n is at least 2 and the radicals R ₁ and R _{2 are} independently aliphatic or branched or cyclic, optionally substituted with hetero atoms alkyl or aryl substituents or H or two radicals R ₁ and R ₂ together with the nitrogen can form a ring and
• b) contain alkyl substituents of the type R ₃ , wherein preferably R ₃ = - (CH ₂ ) _m -CH ₃ with m = 0-3 and a DS> 0.1 and
• c) a total degree of substitution (sum of the individual degrees of substitution) of the substituents - (CH ₂ ) _n -NR ₁ R ₂ and R ₃ , determined from the nitrogen content [for substituents - (CH ₂ ) _n -NR ₁ R ₂ ] or according to Zeisel Cleavage [for substituents R ₃ ], between 0.8 and 2 per anhydroglucose unit.

The Invention will be explained in more detail by the following examples:

The indicated DS refers to pure aminoethylcellulose, ie the total amount was corrected for the water content, the chloride and acetate ion content as well as the sodium ion content. The sodium ion content was determined from the sulfate ash, assuming that it consists of 100% Na ₂ SO ₄ .

The chemicals were obtained from the trade. The nitrogen content was determined by the Kjeldahl method and is based on a double determination of the sample. The viscosities were determined in a solution of 2 wt .-% of the polymer at a shear rate of 2.55 s ^-1 with a rheometer type Rotovisko VT 550, Fa.Haake.

Examples 1-2

Variation of the dispersant

cellulose (17.2 g, dry content 94.24%) is in a mixture of the indicated Dispersant (330.8 g) and water (41.1 g) in a 500 ml four-necked round bottomed glass round bottom stirring apparatus with impeller stirrer suspended.

caustic soda (32.2 g, 49.6 wt .-% in water) is added and after 1 h at Room temperature, diisopropylaminoethyl chloride hydrochloride (40 g) was added and the reaction mixture heated to 70 ° C under a nitrogen atmosphere. To a reaction time of 4 h leaves to cool the approach and neutralized with glacial acetic acid (12 g). The product will be several times with 80% aqueous Acetone and finally washed pure acetone, dried and ground.

In The comparative examples were protic or water-immiscible solvent used. The yields of the reaction are well below 50 %.

Example 3

cellulose (63.7 g, dry content about 95%) is dissolved in a mixture of the specified dispersant and water in a 2 liter jacketed glass reactor with MIG stirrer, suspended.

Caustic soda prills (59.2 g) are added and after 1 h at room temperature, the Diisopropylaminoethyl chloride hydrochloride (148.1 g) was added and the Reaction mixture heated to 70 ° C under nitrogen atmosphere. After a reaction time of 4 h to cool the approach and carries the reaction mixture in acetone acetone. The product will several times with ethanol / acetone / water 40/40/10 (wt .-%) and acetone washed, dried and ground.

A significant reaction took place only in dioxane. The yield is> 50%.

Examples 4-6

The indicated amount of ground cellulose is in a mixture of Dimethoxyethane and water in a 500 ml glass four-necked round bottomed round bottom stirring apparatus with impeller stirrer suspended.

caustic soda (About 50 wt .-%) is added and after 1 h at room temperature Diethylaminoethyl chloride hydrochloride was added and the reaction mixture under nitrogen atmosphere to 70 ° C heated. To a reaction time of 4 h leaves to cool the approach and carries the reaction mixture in acetone acetone. The product will several times with 80% aqueous Acetone and finally washed pure acetone, dried and ground.

Examples 7-9

It The procedure is the same as in the previous examples, with the difference that diisopropylaminoethyl chloride is used.

in the Example 9 is The relationship from cellulose to slurry 1: 10.3 and is thus out of the preferred Area. In this experiment, it was observed that the approach difficult to stir let and therefore the reagents could not be sufficiently distributed.

Examples 10-13

In a 500 mL three-necked flask stirring apparatus with reflux cooler is milled cellulose (17.0 g, dry content 95.12%) in a mixture from dioxane (331 g) and water (57.5 g).

Caustic soda prills (12 g) are added and after 1 h at room temperature become 30 g diisopropylaminoethyl hydrochloride was added and the reaction mixture under nitrogen atmosphere heated to the specified temperature. After a reaction time of 4 h to cool the approach and carries the reaction mixture in acetone. The product is neutralized with acetic acid and several times with 80% aqueous Acetone and finally Acetone, dried and ground.

Examples 14-18

In a 500 mL three-necked flask stirring apparatus is ground cellulose (17.3 g, dry content 93.6%) in one Blended mixture of dimethoxyethane (331 g) and water (41 g).

caustic soda (50% by weight in water, 32.3 g) is added and after 1 h at room temperature 40 g of diisopropylaminoethyl hydrochloride are added and the Reaction mixture under nitrogen atmosphere to the specified temperature heated. After a reaction time of 4 h, the batch is allowed to cool and wears the Reaction mixture in acetone. The product is neutralized with acetic acid and several times with 80% aqueous Acetone and finally Acetone, dried and ground.

in the Example 18 was the reaction temperature outside the preferred range, so that a low yield results.

Claims (13)

Process for the preparation of aminoalkyl group-containing polysaccharides and polysaccharide derivatives, characterized in that a) a polysaccharide or polysaccharide derivative is dispersed in a mixture of a water-miscible aprotic solvent and water and b) the polysaccharide or polysaccharide derivative is alkalized with an inorganic base and c) during the alkalization the used Amount of water in the range between 1 and 55 moles of water per Anhydroglycoseeinheit the polysaccharide or polysaccharide derivative sets and d) then carrying out an amination with an etherifying reagent at elevated temperature if necessary and then e) optionally neutralized and f) the reaction product is filtered off, washed and then optionally dried and served basis. Method according to claim 1, characterized in that that as a water-miscible aprotic solvent a water miscible Ether is used. Method according to one of the preceding claims, characterized characterized in that the ratio from polysaccharide or polysaccharide derivative to the total amount of water miscible aprotic solvents and water is 1: 4 to 1:50 parts by weight. Method according to one of the preceding claims, characterized characterized in that the reaction at temperatures of about 40 to 90 ° C is performed. Method according to one of the preceding claims, characterized characterized in that is used as the polysaccharide cellulose. Method according to one of the preceding claims, characterized characterized in that as polysaccharide one or more polysaccharides from the group pullulan, dextran, guar, xylans, xanthan gum or carrageenan be used. Method according to one of the preceding claims, characterized in that it uses cellulose ethers as polysaccharide derivatives become. Method according to one of the preceding claims, characterized in that a polysaccharide is used in the reaction and about 2 moles of etherifying reagent per anhydrous sugar unit or less. Method according to one of the preceding claims, characterized in that 0.01 up to 1.5 mol etherification reagent per anhydroglucose unit (AGU) be used. Method according to one of the preceding claims, characterized in that 0.1 to 3 mol of etherifying reagent per AGU. Method according to one of the preceding claims, characterized characterized in that purified reaction product more than 50% of the etherifying reagent used bound to the cellulose, calculated from the nitrogen content of the purified reaction product. Amino group-containing polysaccharide derivatives containing a) substituents of the type - (CH ₂ ) _n -NR ₁ R ₂ , wherein n is at least 2 and the radicals R ₁ and R ₂ independently of one another aliphatic or branched or cyclic, optionally substituted by hetero atoms alkyl or aryl Substituents or H or two radicals R ₁ and R ₂ can form a ring together with the nitrogen and b) contain alkyl substituents of the type R ₃ , R ₃ preferably being - (CH ₂ ) _m -CH ₃ with m = 0- 3 and a DS> 0.1 and c) a total degree of substitution (sum of the individual degrees of substitution) of the substituents - (CH ₂ ) _n -NR ₁ R ₂ and R ₃ , determined from the nitrogen content [for substituents - (CH ₂ ) _n -NR ₁ R ₂ ] or after Zeisel cleavage [for substituents R ₃ ], between 0.8 and 2 per anhydroglucose unit. Amino group-containing polysaccharide derivatives which a) substituents of the type - (CH ₂ ) _n -NR ₁ R ₂ bound to the cellulose or a side chain, eg hydroxyalkyl chain, wherein n is at least 2 and the radicals R ₁ and R _{2 are} independently aliphatic or branched or cyclic, optionally substituted by hetero atoms alkyl or aryl substituents or H or two radicals R ₁ and R ₂ may form a ring together with the nitrogen and b) contain alkyl substituents of the type R ₃ , wherein preferably R ₃ = - (CH ₂ ) _m -CH ₃ with m = 0-3 and a DS _alkyl > 0.1 and c) hydroxyalkyl substituents of the type R ₄ , wherein preferably R ₄ = -CH ₂ -CH (C _p H _{2p + 1} ) O- {CH ₂ -CH (C _p H _{2p + 1} ) O} _q -C _r H _{2r + 1} with p = 0 or 1, q = 0-30, r = 0 or 1 and an MS _hydroxyalkyl > 0.1 and the d) a total degree of substitution (sum of the individual degrees of substitution) of the substituents - (CH ₂ ) _n -NR ₁ R ₂ , and R ₃ and R ₄ , determined from the nitrogen content [for substituents - (CH ₂ ) _n -NR ₁ R ₂ ] or to Zeisel Have cleavage [for substituents R ₃ and R ₄ ], between 0.8 and 2.5 per anhydroglucose unit.