CS200799B1 - Method of preparing oxidized pectins available as sequestring additive into detergent mixtures - Google Patents

Description

SUMMARY OF THE INVENTION It is an object of the present invention to prepare oxidized pectins as e-extraction ingredients in detergent compositions which can replace up to 50 polyphosphates used hitherto, in particular sodium tripolyphosphate.

Up to now, polyphosphates, namely sodium tripolyphosphate, which is a necessary additive for washing in hard water, are used as sequencing agents in detergents. It is a complex binding of alkaline earth metals calcium and magnesium, which are the cause of water hardness and binding of Salami metals such as iron, honey, etc. A major disadvantage of polyphosphates is their interaction with wastewater, where phosphates induce eutrophication processes, ie. extraordinary growth of phytoplankton, especially algae. These processes, especially in standing waters (lakes, reservoirs, estuaries), cause water suffocation, transition to anaerobic processes associated with the release of hydrogen sulfide and the disappearance of biological processes in living organisms. For this reason, polyphosphate substitutes are being sought which would limit the application of eutrophication processes in waste water. So far, organic compounds have been proposed which are capable of complex binding of alkaline earth metals. These are, in particular, the following compounds in the form of alkaline, sodium salts (complexones): nitrilotriacetic acid, ethylenediaminetetraacetic acid; polymeric acids: such as polyacrylic acid, polyethylene maleic acid; oxidized starches; lower di and tricarboxylic acids: citric acid, tartaric acid and the like.

200 799

Said compounds, if contained in a smaller molecule of several carboxylic acids, are characterized in the form of alkali salts only by a weaker aeketetration efficiency while at the same time good biodegradability, e.g. citric acid. Conversely, for polymeric acids such as e.g. polyacrylic acid, it is a good sequestering efficiency, but at the same time a poor biodegradability.

The aforementioned drawbacks are overcome by the invention, wherein the aa nfa pectin is treated with chlorine gas in an aqueous sodium hydroxide solution at a temperature of 0 to 30 ° C, preferably 10 to 20 ° C, and the product is isolated by blowing into a water-miscible organic solvent. , preferably an alcohol, e.g. methanol.

The advantage of the proposed use of oxidized pectins is that the pectins themselves are characterized by a high complexing efficiency of the binding of alkaline earth metals calcium and magnesium, and this efficiency and by oxidation by chlorination in the sodium hydroxide environment will be enhanced.

Cl

COOH oxidation Na 01?

COONa

As a result, ea exerts high alkaline earth metal binding and sequestering efficiency.

In Saler, the preparation of oxidized pectins for use as sequencing agents is described in the Examples without being limited to these.

Example 1

100 g of sunflower pectin aa is suspended in 900 ml of water and allowed to swell. The pH of the suspension is adjusted to 9 with sodium hydroxide solution. Thereafter, 290 g of chlorine and 325 g of NaOH in the form of a 25% aqueous solution are introduced in a synchronous manner over a period of 4 hours so that the pH of the solution is kept between 8 and 9. is maintained at between 10 and 20 ° C with ice cooling. It is then stirred at pH 8 to 9 at normal temperature to complete the oxidation reaction. Thereafter, the reaction mixture was freed from the insoluble matter by filtration and poured into 7 L of methanol with vigorous stirring. The product precipitates as a good filterable precipitate as the sodium salt. It is filtered off with suction and washed with 1 l of methanol and dried in a vacuum desiccator. 87 g of a white product are obtained.

The product thus obtained is used as a laundry additive, replacing aa some of the sodium tripolyphosphate.

Washing was carried out on a cotton companion fabric according to CSN 80 01 01 in 10 mills at a temperature of 80 ° C, soiled with a model dirt of the following composition:

Sunar - 40 g, gelatin - 3 g, black ink - 22 g, refined sunflower oil - 60 g, carbon tetrachloride - 25 g, distilled water - 200 g. Laundry on laboratory washing machine Kolteet. whiteness

200,798 soiled samples as well as washed and unclean samples were determined on a Zeies Jena leukometer with a white filter. The content of the components of the washing bath (total of 5 g of detergents per liter of bath), as well as the percentage of washing results, are shown in Tab. First

Tab. 1. Percent wash of model cotton spin spin using g washing additive per liter of washing bath, the washing additive containing oxidized sunflower pectin

component

Detergent composition percentage

ABS

TPF oxide. pectin Na ₂ OO ₃ Na ₂ SO ₄ CMC / Lovoza

25 25 40 30 - 10 19 19 15 15 1 1

25 25 20 10 20 30 19 19 15 15 1 1

25 25 - - 40 - 19 19 15 15 1 1

Hard water ° N 20 ° N

66.18 64.94

55.55 54.40

Percentage of wash

63 '23 58,13

53.41 52.80

43.83 41.52

38.03 38.89

Example 2

As Example 1, however, instead of sunflower pectin ea, citrus pectin will yield 91 g of product.

Example 3

As Example 1, however, instead of sunflower pectin, beet pectin was used. Yield 82 g.

Claims (4)

Process for the preparation of oxidized pectins suitable as sequestering additives for detergent compositions, characterized in that the pectin is treated with chlorine gas in an aqueous solution of sodium hydroxide at 0 to 30 ° C, preferably 10 to 20 ° C and the product is isolated by pouring into a water miscible organic solvent, preferably an alcohol such as methanol. 2. A method according to claim 1, wherein aa is sunflower pectin. 3. The method of claim 1, wherein the pectin is citrus pectin. 4. A method according to claim 1, wherein the pectin is a beet pectin.