QUATERNARY AMMONIUM SALTS OF CARBOXYMETHYLCELLULOSE

Abstract: A quaternary ammonium salt of carboxymethylcellulose having the formula: wherein R is a hydrogen atom or a quaternary ammonio carboxymethyl group, and n is an integer from 10 to 1000, provided that a degree of substitution by carboxymethyl group per anhydrous glucose unit in said carboxymethylcel­ lulose is 1.5 or more.

Description: The present invention relates to quaternary ammonium salts of carboxymethylcellulose. Particularly it relates to those wherein a degree of substitution by carboxymethyl group per anhydrous glucose unit of carboxymethylcellulose (hereinafter referred to as "DS") is from 1.9 to 2.8. As quaternary ammonium salts of carboxymethylcellulose (hereinafter referred to as "CMC") there have been known the dimethyllaurylcetylammonium salt (DE-A- 1,103,336), trimethyloctadecylammonium salt (US-A- 2,881,074), dodecyldimethyl(3,4-dichlorobenzyl) ammonium salt [Deut.Apotheker-Ztg., 106 (35), 1206-8 (1966)], tetradecylpyridinium salt and cetyltrimethylammonium salt [Pham. Ind., 37, (2), 100, (1976)]. Macromol. Chem., Vol. 182, p. 3577 discloses carboxymethyl cellulose having a degree of substitution of 1.7 and quaternary ammonium salts derived therefrom. These quaternary ammonium salts of CMC are used to utilize the characteristic properties of CMC moiety as a soluble high molecular substance as well as the quaternary ammonium moiety. However, DS of CMCs of the above prior salts is believed to be 1.0 or less judging from DS of the commercially available products, while the content of the quaternary ammonium moiety is obliged to be 1.0 or less molecule per anhydrous glucose unit of CMC from the theoretical viewpoint that the quaternary ammonium group can be combined with the carboxymethyl group in the ratio of 1 : 1. This means that it can not be expected to utilize the characteristic property of the quaternary ammonium moiety to be exerted when it exists in more than 1.0 molecule per anhydrous glucose unit of CMC. In these known quaternary ammonium salts of CMC, when the molecular weight of the quaternary ammonium moiety is low (e.g., lower alkyl substituted ammonium moiety), they are soluble in water but insoluble in organic solvents, and when it is high, they become insoluble in water and sparingly soluble in polar solvents such as alcohols and acetone and in non-polar solvents such as toluene. Therefore, these salts could not be used for usages to be in the form of solution in organic solvents. The present invention provides a quaternary ammonium salt of carboxymethylcellulose having the formula: wherein R is a hydrogen atom or a quaternary ammonio carboxymethyl group, and n is an integer from 10 to 1000, wherein the degree of substitution by carboxymethyl group per anhydrous glucose unit in said carboxymethylcellulose is 1.9 to 2.8, and the quaternary ammonio carboxymethyl group has the subformula: where (i) three of any of R¹ to R⁴ are methyl group, and the remaining one is lauryl or stearyl group, (ii) three of any of R¹ to R⁴ are octyl group, and the remaining one is methyl group, (iii) two of any of R¹ to R⁴ are methyl group and any of the remaining two are stearyl group, (iv) three of R¹ to R⁴ are three methyl, ethyl or n-butyl groups, or one of the tetradecyl group and two of methyl group, and the remaining one is benzyl, trimethylammoniumhexyl or trimethylammonium decamethyl group, (v) two of any of R¹ to R⁴ are methyl group, and the remaining two are benzyl group and diisobutylphenoxyethyleneoxyethyl or (diisobutyl) methylphenoxy ethyleneoxyethyl group, or (vi) one of R¹ to R⁴ is n-cetyl or lauryl group and the remaining three form pyridinium group together with an adjacent nitrogen atom. Figs. 1 - 12 show infrared absorption spectra of the quaternary ammonium salts of CMC of the present invention. Fig. 13 shows infrared absorption spectrum of CMC (DS=2.41). Fig. 1 : Laurylpyridinium CMC Fig. 2 : Tetradecyldimethylbenzylammonium CMC Fig. 3 : Lauryltrimethylammonium CMC Fig. 4 : Trioctylmethylammonium CMC Fig. 5 : Tetra-n-butylammonium CMC Fig. 6 : Stearyltrimethylammonium CMC Fig. 7 : Dimethyldistearylammonium CMC Fig. 8 : Benzethonium CMC Fig. 9 : Methylbenzethonium CMC Fig. 10: Cetylpyridinium CMC Fig. 11: Hexamethonium CMC Fig. 12: Decamethonium CMC Fig. 13: CMC sodium (DS=2.41, DP=480) In the quaternary ammonium salts of CMC of the present invention, those having a quaternary ammonium group with relatively smaller molecular weight are generally soluble in water but insoluble in organic solvents. For example, when the quaternary ammonium group is tetra-n-butylammonium, tetra-n-amylammonium, dimethyldibenzylammonium, triethylbenzylammonium or tri-n-butylbenzylammonium, they are soluble in water but insoluble in polar organic solvents such as alcohols or acetone and non-polar organic solvents such as toluene. On the other hand, the salts having an quaternary ammonium group of relatively large molecular weight are generally insoluble in water but are soluble in various kinds of organic solvents, depending upon the kinds of the ammonium groups. For example, the salts of lauryltrimethylammonium, tetradecyldimethylbenzylammonium and stearyltrimethylammonium are insoluble in water but are soluble in methanol and ethanol. In case where trioctylmethyl ammonium group is contained, it is insoluble in water, but becomes soluble in methanol, ethanol and isopropanol when DS of CMC is 1.6 or more and further soluble in hydrocarbons such as toluene when DS is 2.0 or more. Also, the salt of dimethyldistearylammonium group where DS is 2.84 is soluble in hydrocarbons such as benzene. Also, the salt of a cyclic quaternary ammonium group such as laurylpyridinium group is insoluble in water regardless of DS of CMC but is soluble in lower alcohols when DS is 2.5 or more. As explained above, the present invention can provide the quaternary ammonium salts of CMC which are soluble in water and also in various organic solvents, selecting an appropriate quaternary ammonium group. The quaternary ammonium salts of CMC in accordance with the present invention possess the characteristics of thickening property, colloid-protection property or the like as a soluble high molecular substance of CMC and of antistatic property, affinity with hair, sterility or the like as the property of the quaternary ammonium group. Therefore, they can be used for extensive fields, e.g., as thickening agents, antistatic agents, or a material for cosmetic or bacteriostats. Furthermore, the quaternary ammonium salts of CMC of the present invention will retain much characteristic of the quaternary ammonium group, compared with the known CMC quaternary ammonium salts, because the quaternary ammonium salts of the present invention are higher in DS value of CMC and much in an amount of quaternary ammonum group bonded. The quaternary ammonium salts of CMC may be prepared by mixing and reacting a solution of CMC with DS of 1.5 or more or its salt with an appropriate quaternary ammonium compound or its solution and subjecting to isolation and purification. CMC with DS of 1.5 or more used as the starting material in the above-mentioned process may be prepared by, for example, multi-stage etherification method as described in Japanese Patent Application Laid-Open No. 176202/1983. When CMC is used in a salt, it may be the alkali metal salt such as sodium or potassium salts, or the calcium salt, among which the sodium salt is preferable. The quaternary ammonium compounds containing the formula of may be those in which the anion is a halide ion such as chloride ion, bromide ion or fluoride ion, or sulfate ion, nitrate ion or phosphate ion. In the above process, CMC on its salt is put into an aqueous solution and then contacted with the quaternary ammonium compound. Especially it is preferred to add the quaternary ammonium compound or its aqueous solution to an aqueous solution of CMC salt. The reaction is usually conducted at a temperature near room temperature. The amount of the quaternary ammonium compound to be employed is preferably in an equivalent or excess to the carboxymethyl group, although it may be less than the equivalent amount. The reaction mixture, when the resultant quaternary ammonium salt is water-soluble, is added into a hydrophilic solvent such as alcohol or acetone to precipitate and the precipitate is washed with a mixture of said solvent and water to remove the raw material of the quaternary ammonium compound. On the other hand, when the resultant is insoluble in water, the resultant precipitate is collected, well washed with water and dried. The present invention is further illustrated by giving Examples, hereinafter. A degree of substitution by carboxymethyl group per anhydrous glucose unit in CMC (DS) used in the following examples was determined as follows: A degree of substitution by carboxymethyl group per anhydrous glucose unit of CMC (DS) used in the following examples was determined as follows: One gram of CMC (calculated as being pure) was dissolved in a flask containing 200ml of pure water and 100ml of N/10 NaOH. Next, the excess of N/10NaOH was titrated with N/10 H₂SO₄ using phenolphthalein as an indicator. The DS was calculated from the following equation based on the amount of titrant, B ml, added. where f₁: factor of N/10 H₂SO₄ f₂: factor of N/10 NaOH Further, a degree of polymerisation of CMC sodium and the resulting quaternary ammonia salt (hereinafter referred to as "DP") was determined by osmometry of a solution of a sample in 0.1N Nacl. The numerical value of the DP corresponds to 2 x n wherein n means n in the formula of the salt of the present invention on page 2. The DP of each of the quaternary ammonium salts prepared in fallowing Examples was approximately the same as that of CMC sodium of its starting material. Example 1 To 200g of 1% aqueous solution of each of CMC sodium with a variety of DS and viscosity was added 10% excess amount of each of the quaternary ammonium compounds. Acetone was added to the reaction mixture to yield a precipitate and it was washed with 90% aqueous acetone and then dried in vacuo at ordinary temperature to obtain a quaternary ammonium salt of CMC. Any of the obtained salts was soluble in water but insoluble in lower alcohols such as ethanol. i) CMC sodium ii) Quaternary Ammonium-Compound Benzyltriethylammonium chloride Benzyltri-n-butylammonium chloride Tetra-n-butylammonium chloride Tetra-n-amylammonium chloride Dimethylbenzylammonium chloride Example 2 To 200g of 1% aqueous solution of each of CMC sodium with a variety of DS was added 10% excess amount of each of the quaternary ammonium compounds with stirring. The resultant precipitate was filtered off, sufficiently washed with water and then dried in vacuo at ordinary temperature to obtain a quaternary ammonium salt of CMC. Solubility of these products is shown in Table 1. The quaternary ammonium salt obtaind in the same manner as mentioned above from dimethyl distearyl ammonium chloride and CMC sodium with a DS of 2.84 was soluble in hydrocarbons such as benzene or the like. i) CMC sodium Figs. 1 - 7 show infrared absorption spectra of seven quaternary ammonium salts of CMC prepared in the above Examples 1 and 2. Fig. 1 Laurylpyridinium CMC (DS of CMC sodium : 2.84) The absorption at 3050cm⁻¹ to aromatic C-H stretching vibration, the absorption at 1600cm⁻¹ to -COO⁻ carboxylic acid C=O stretching vibration, the absorptions at 2900 and 2850cm⁻¹ to C-H of -CH₂- stretching vibrations, the absorptions at 690 and 720cm⁻¹ to monosubstituted pyridine structure vibration, and the absorptions at 980 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration. Fig. 2 Tetradecyl dimethyl benzyl ammonium CMC (DS of CMC sodium : 2.41) The absorption at 1600cm⁻¹ to -COO⁻ carboxylic acid C=O stretching vibration, the absorptions at 2900 and 2850cm⁻¹ to - CH₂ -, the absorptions of 710 and 730cm⁻¹ to monosubstituted phenyl group, and the absorption at 980 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 3 Lauryl trimethyl ammonium CMC (DS of CMC sodium : 1.94) The absorption at 1600cm⁻¹ to - COO⁻ , the absorption at 2900 and 2850cm⁻¹ to - CH₂ -, and the absorption at 980 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 4 Trioctyl methyl ammonium CMC (DS of CMC-Na : 2.41) The absorption at 1600cm⁻¹ to -COO⁻, the absorption at 2900 and 2850 cm⁻¹ to - CH₂ -, and the absorption at 1000 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 5 Tetra-n-butyl ammonium CMC (DS of CMC-Na : 2.84) The absorption at 1600cm⁻¹ to -COO⁻, the absorption at 2930cm⁻¹ to - CH₂ -, and the absorption at 1000 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 6 Stearyl trimethyl ammonium CMC (DS of CMC-Na:1.58) The absorption at 1600cm⁻¹ to - COO⁻, the absorption at 2920 and 2850cm⁻¹ to - CH₂ -, and the absorption at 980-1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 7 Dimethyl distearyl ammonium CMC (DS of CMC-Na:2.84) The absorption at 1610cm⁻¹ to -COO⁻, the absorption at 2940 and 2870cm⁻¹ to - CH₂ -, and the absorption at 1000 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Example 3 To 200g of 1% aqueous solution of following CMC sodium was added an equivalent amount of each of quaternary ammonium compounds and stirred. The resultant precipitate was filtered off, sufficiently washed with water and dried in vacuo at ordinary temperature to obtain a corresponding quaternary ammonium salt. Solubility of these salts is shown in Table 2, and any of them was insoluble in water. i) CMC Sodium ii) Quatermarry Ammonium Compound Benzethonium chloride Methylbenzethonium chloride Cetylpyridium chloride Figs. 8 - 10 show infrared absorption spectra of three quaternary ammonium salts of CMC prepared in the above Example 3. Fig. 8 Benzethonium CMC (DS of CMC Na = 2.41) The absorption at 1610cm⁻¹ to -COO⁻, the absorption at 830cm⁻¹ to 1,4 substituted phenyl, the absorption at 700 - 770cm⁻¹ to monosubstituted phenyl and the absorption at 980 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 9 Methylbenzethonium CMC (DS of CMC Na = 2.41) The absorption at 1610cm⁻¹ to -COO⁻, the absorption at 700 - 770cm⁻¹ to monosubstituted phenyl, and the absorption at 980 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 10 Cetylpyridinium CMC (DS of CMCNa = 2.41) The absorption at 1600cm⁻¹ to -COO⁻, the absorption at 2900 and 2850cm⁻¹ to C-H of -CH₂- stretching vibration, the absorption at 690 and 720cm⁻¹ to mono substituted pyridine structure vibration, and the absorption at 980 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Example 4 To 200g of 1% aqueous solution of following CMC sodium was added equivalent amount of each of following quaternary ammonium compounds and stirred. Acetone was added to the reaction mixture to yield a precipitate and it was washed with 90% aqueous acetone and dried in vacuo at ordinary temperature to obtain corresponding quaternary ammonium salts. All the resultants were soluble in water but did not completely dissolved in lower alcohols such as ethanol. i) CMC sodium ii)Quaternary ammonium compounds Hexamethonium chloride Decamethonium chloride Figs. 11 and 12 show infrared absorption spectra of two quaternary ammonium salts of CMC prepared in Example 4. Fig. 11 Hexamethonium CMC The absorption at 1600cm⁻¹ to -COO⁻, the absorption at 2930cm⁻¹ to -CH₂-, and the absorption at 1000 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration Fig. 12 Decamethonium CMC The absorption at 1600cm⁻¹ to -COO⁻, the absorption at 2930cm⁻¹ to -CH₂-, and the absorption at 1000 - 1170cm⁻¹ to cellulose C-O stretching vibration and glucose ring vibration

Claims: A quaternary ammonium salt of carboxymethylcellulose having the formula: wherein R is a hydrogen atom or a quaternary ammonio carboxymethyl group, and n is an integer from 10 to 1000, wherein the degree of substitution by carboxymethyl group per anhydrous glucose unit in said carboxymethylcellulose is 1.9 to 2.8, and the quaternary ammonio carboxymethyl group has the subformula: where (i) three of any of R¹ to R⁴ are methyl group, and the remaining one is lauryl or stearyl group, (ii) three of any of R¹ to R⁴ are octyl group, and the remaining one is methyl group, (iii) two of any of R¹ to R⁴ are methyl group and any of the remaining two are stearyl group, (iv) three of R¹ to R⁴ are three methyl, ethyl or n-butyl groups, or one of the tetradecyl group and two of methyl group, and the remaining one is benzyl, trimethylammoniumhexyl or trimethylammonium decamethyl group, (v) two of any of R¹ to R⁴ are methyl group, and the remaining two are benzyl group and diisobutylphenoxyethyleneoxyethyl or (diisobutyl) methylphenoxy ethyleneoxyethyl group, or (vi) one of R¹ to R⁴ is n-cetyl or lauryl group and the remaining three form pyridinium group together with an adjacent nitrogen atom.

Inventors: NAMIKOSHI, HAJIME, OHMIYA, TAKEO
Applicants: DAICEL CHEMICAL INDUSTRIES, LTD.
Application year: 1985
Main classification: C08B11
IPC codes: C08B11, A61K8, A61Q5, C09K3